Consulta: subjectFacets:"Modeling"
Registros recuperados: 223
Data/hora: 13/06/2024 04:21:36

Predicción de puntos de calor como precursores de incendios forestales
Provedor de dados: 32
Autores: González Ramos, Adalberto.
Con el propósito de determinar la relación entre factores humanos y factores geográficos con la presencia de puntos de calor que pudieran constituir posibles incendios forestales, se definió una metodología para evaluar tres tipos de arquitecturas de redes neuronales backpropagation, empleándose como datos de entrada cuatro modelos que resultaron de combinar seis factores humanos con siete factores geográficos. Como datos de salida se usaron los puntos de calor detectados en el territorio que comprende las zonas susceptibles a incendios forestales del Estado de México durante el período del año 2000 al 2005 para las etapas de entrenamiento y prueba. Asimismo, datos del año 2006 se destinaron para la comprobación del funcionamiento de la red. Se usó...
Tipo: Tesis
Palavras-chave: Algoritmos genéticos; Redes neuronales retroalimentadas; Predicción de incendios forestales; Modelación; Puntos de calor; Maestría; Forestal; Genetic algorithm; Backpropagation neural nets; Wilfires prediction; Modeling; Fire points.
Ano: 2008
URL: http://hdl.handle.net/10521/1652

Análisis de las unidades de riego con aprovechamiento superficial en la Cuenca Lerma Chapala, México.
Provedor de dados: 32
Autores: González Covarrubias, Galdino Daniel.
En el presente estudio se realizó el análisis de las Unidades de Riego con aprovechamiento superficial en la Cuenca Lerma Chapala, México, a través de la georrefenciación y caracterización de la infraestructura hidroagrícola, padrón de usuarios y catastro, integrándolos en un Modelo de Sistema de Información Geográfica (SIG). Esto permitió conocer en forma precisa la información relevante de dichas Unidades. Se caracterizaron 1,364 unidades de riego con un total de 56,266 usuarios que detentan 114,975.26 hectáreas. La longitud de la red de conducción es de 2,435 km y la longitud de la red de drenaje es de 2,643 km, y 34,965 estructuras de control.  La integración de las capas de información generadas en formato shape-file (*.shp) al Modelo de SIG de la...
Palavras-chave: Modelación; SIG; Riego; Agua; Sustentabilidad; Cuenca; Modeling; GIS; Irrigation; Water; Sustainability; Watershed; Hidrociencias; Maestría Tecnológica.
Ano: 2013
URL: http://hdl.handle.net/10521/2072

Diseño participativo para mejorar la sustentabilidad de los agroecosistemas de la microcuenca Paso de Ovejas 1 en el estado de Veracruz, México.
Provedor de dados: 32
Autores: Candelaria Martínez, Bernardino.
Se caracterizaron los agroecosistemas (AES) de la microcuenca Paso de Ovejas 1 (POV-1) y con base en las condiciones locales se diseñó un índice agregado de sustentabilidad, en el cual se incluyeron cuatro dimensiones: ambiental, económica, social y humana, con un total de 29 indicadores. Para determinar los valores umbrales (máximo y mínimo) de cada indicador se consideraron parámetros locales, de cada grupo se seleccionó un AES al azar al que se le denominó agroecosistema tipo, en el que se realizaron evaluaciones detalladas y se representó en un modelo de simulación. Los grupos (G) identificados fueron: G1) tendencia a la ganadería con alta disponibilidad de tierras, G2) tendencia al manejo de cultivos con baja disponibilidad de tierras y G3) tendencia...
Palavras-chave: Modelación; Modelos; Escenario; Indice agregado; Territorio; Modeling; Models; Scenario; Aggregation index; Territory; Agroecosistemas Tropicales; Doctorado.
Ano: 2011
URL: http://hdl.handle.net/10521/548

Assessing the Performance of Natural Resource Systems
Provedor de dados: 7
Autores: Campbell, Bruce; Center for International Forestry Research (CIFOR); b.campbell@cgiar.org; Sayer, Jeffrey A; WWF (World Wildlife Fund); jsayer@wwfint.org; Frost, Peter; Institute of Environmental Studies; pfrost@compcentre.uz.ac.zw; Vermeulen, Sonja; International Institute for Environment and Development; sonja.vermeulen@iied.org; Cunningham, Tony; World Wildlife Fund/UNESCO/Kew People and Plants Initiative; peopleplants@bigpond.com; Prabhu, Ravi; CIFOR Regional Office; r.prabhu@cgiar.org.
Assessing the performance of management is central to natural resource management, in terms of improving the efficiency of interventions in an adaptive-learning cycle. This is not simple, given that such systems generally have multiple scales of interaction and response; high frequency of nonlinearity, uncertainty, and time lags; multiple stakeholders with contrasting objectives; and a high degree of context specificity. The importance of bounding the problem and preparing a conceptual model of the system is highlighted. We suggest that the capital assets approach to livelihoods may be an appropriate organizing principle for the selection of indicators of system performance. In this approach, five capital assets are recognized: physical, financial, social,...
Tipo: Peer-Reviewed Reports
Palavras-chave: Capital assets; Conceptual models; Decision support; Livelihoods; Modeling; Multivariate statistics; Natural resource systems; Performance; Zimbabwe.
Ano: 2001

Evaluating Today's Landscape Multifunctionality and Providing an Alternative Future: A Normative Scenario Approach
Provedor de dados: 7
Autores: Waldhardt, Rainer; Landscape Ecology and Landscape Planning, Justus-Liebig-University Giessen; rainer.waldhardt@umwelt.uni-giessen.de; Bach, Martin; Resources Management, Justus-Liebig-University Giessen;; Breuer, Lutz; Resources Management, Justus-Liebig-University Giessen;; Frede, Hans-Georg; Resources Management, Justus-Liebig-University Giessen;; Ginzler, Oliver; Landscape Ecology and Landscape Planning, Justus-Liebig-University Giessen;; Gottschalk, Thomas; Animal Ecology, Justus-Liebig-University Giessen;; Julich, Stefan; Resources Management, Justus-Liebig-University Giessen;; Krumpholz, Matthias; Agribusiness Management, Justus-Liebig-University Giessen;; Kuhlmann, Friedrich; Agribusiness Management, Justus-Liebig-University Giessen;; Otte, Annette; Landscape Ecology and Landscape Planning, Justus-Liebig-University Giessen;; Reger, Birgit; Landscape Ecology and Landscape Planning, Justus-Liebig-University Giessen;; Reiher, Wolfgang; Resources Management, Justus-Liebig-University Giessen;; Schmitz, Kim; Agricultural and Development Policy, Justus-Liebig-University Giessen;; Schmitz, P. Michael; Agricultural and Development Policy, Justus-Liebig-University Giessen;; Sheridan, Patrick; Agribusiness Management, Justus-Liebig-University Giessen;; Simmering, Dietmar; Landscape Ecology and Landscape Planning, Justus-Liebig-University Giessen;; Weist, Cornelia; Biometry and Population Genetics, Justus-Liebig-University Giessen;; Wolters, Volkmar; Animal Ecology, Justus-Liebig-University Giessen;.
Tipo: Peer-Reviewed Reports
Palavras-chave: Agriculture; Ecosystem services; Germany; Modeling; Sustainability.
Ano: 2010

Conceptual Models as Tools for Communication Across Disciplines
Provedor de dados: 7
Autores: Heemskerk, Marieke; University of Wisconsin-Madison; mheemskerk@wisc.edu; Wilson, Karen; Carleton University; kwilson@carleton.edu; Pavao-Zuckerman, Mitchell; Institute of Ecology, University of Georgia; mzucker@sparc.ecology.uga.edu.
To better understand and manage complex social-ecological systems, social scientists and ecologists must collaborate. However, issues related to language and research approaches can make it hard for researchers in different fields to work together. This paper suggests that researchers can improve interdisciplinary science through the use of conceptual models as a communication tool. The authors share lessons from a workshop in which interdisciplinary teams of young scientists developed conceptual models of social-ecological systems using data sets and metadata from Long-Term Ecological Research sites across the United States. Both the process of model building and the models that were created are discussed. The exercise revealed that the presence of social...
Tipo: Peer-Reviewed Reports
Palavras-chave: Integrative Graduate Education Research and Training; Long-Term Ecological Research; Conceptual model; Interdisciplinary research; Modeling; Social-ecological systems; Workshop.
Ano: 2003

On Nature, Models, and Simplicity
Provedor de dados: 7
Autores: Baumann, Michael; University of British Columbia and ananature.com Scientific Services; baumann@interchange.ubc.ca.
Tipo: Peer-Reviewed Reports
Palavras-chave: Complexity; Epistemology; Modeling; Simplicity.
Ano: 2000

Adaptive Analysis of Locally Complex Systems in a Globally Complex World
Provedor de dados: 7
Autores: Lynam, Timothy; Tropical Resource Ecology Program, University of Zimbabwe; tlynam@science.uz.ac.zw.
Zambezi Valley agro-ecosystems are environmentally, economically, and institutionally variable. This variability means that it is not possible to measure everything necessary to develop a predictive understanding of them. In particular, because people and their environments are constantly changing, what was measured yesterday may change by tomorrow.  Here, I describe elements of the approach that I have developed to address this problem. Called DAAWN, for Detail as and When Needed, the approach advocates an iterative and multiscaled methodology in which we first capture as broad an understanding of the system as possible and then use awareness developed at this scale to identify where to focus subsequent, more detailed, investigations. Because we cannot...
Tipo: Peer-Reviewed Reports
Palavras-chave: Comples adaptive systems; Household and resource economics; Livelihood strategies; Modeling; Multi-agent simulation models; Natural resource use; Participatory systems analysis; Southern Africa; Spidergrams.
Ano: 1999

Resilience Thinking and a Decision-Analytic Approach to Conservation: Strange Bedfellows or Essential Partners?
Provedor de dados: 7
Autores: Johnson, Fred A; United States Geological Survey; fjohnson@usgs.gov; Williams, B. Ken; The Wildlife Society; byron_ken_williams@nbs.gov; Nichols, James D; United States Geological Survey; Jim_Nichols@usgs.gov.
Tipo: Peer-Reviewed Synthesis
Palavras-chave: Adaptive management; Alternative stability regime; Biodiversity; Conservation; Decision analysis; Decision science; Dynamic decisions; Modeling; Optimization; Resilience; Robust decision making; Systems; Uncertainty.
Ano: 2013

Modeling the Geography of Migratory Pathways and Stopover Habitats for Neotropical Migratory Birds
Provedor de dados: 7
Autores: Tankersley, Jr., Roger; Tennessee Valley Authority; rdtankersley@tva.gov; Orvis, Kenneth; ; orvis@utk.edu.
Intact migratory routes are critical for the stability of forest-dwelling, neotropical, migratory bird populations, and mortality along migratory pathways may be significant. Yet we know almost nothing about the geography of available stopovers or the possible migratory pathways that connect optimal stopovers. We undertake a spatial analysis of stopover habitat availability and then model potential migratory pathways between optimal stopovers in the eastern United States. Using models of fixed orientation and fixed nightly flight distance between stopovers during spring migration, we explore whether a simple endogenous migratory program is sufficient to ensure successful migration across the modern landscape.  Our model runs suggest that the modern...
Tipo: Peer-Reviewed Reports
Palavras-chave: Conservation; Forest fragmentation; Habitat; Migration; Modeling; Neotropical migratory birds; Stopover ecology.
Ano: 2003

A method for assessing ecological values to reconcile multiple land use needs
Provedor de dados: 7
Autores: Kangas, Katja M; Natural Resources Institute Finland, Oulu; katja.kangas@luke.fi; Tolvanen, Anne; Natural Resources Institute Finland, Oulu; Department of Ecology, University of Oulu; anne.tolvanen@luke.fi; Tarvainen, Oili; Natural Resources Institute Finland, Oulu; oili.tarvainen@luke.fi; Nikula, Ari; Natural Resources Institute Finland, Rovaniemi; ari.nikula@luke.fi; Nivala, Vesa; Natural Resources Institute Finland, Rovaniemi; vesa.nivala@luke.fi; Huhta, Esa; Natural Resources Institute Finland, Rovaniemi; esa.huhta@luke.fi.
We present a new method for ecologically sustainable land use planning within multiple land use schemes. Our aims were (1) to develop a method that can be used to locate important areas based on their ecological values; (2) to evaluate the quality, quantity, availability, and usability of existing ecological data sets; and (3) to demonstrate the use of the method in Eastern Finland, where there are requirements for the simultaneous development of nature conservation, tourism, and recreation. We compiled all available ecological data sets from the study area, complemented the missing data using habitat suitability modeling, calculated the total ecological score (TES) for each 1 ha grid cell in the study area, and finally, demonstrated the use of TES in...
Tipo: Peer-Reviewed Reports
Palavras-chave: Biodiversity; Conservation; Ecological value; Land use planning; Modeling; Spatial data; Tourism.
Ano: 2016

A Participatory Modeling Process to Capture Indigenous Ways of Adaptability to Uncertainty: Outputs From an Experiment in West African Drylands
Provedor de dados: 7
Autores: d'Aquino, Patrick; CIRAD; daquino@cirad.fr; Bah, Alassane; UMISCO ESP UCAD Dakar; alassane.bah@gmail.com.
Over the centuries, local communities have shaped atypical rules to deal with the uncertainty of their environment. They have developed complex prototypes for flexible overlapping institutions and arrangements to adapt their rules and uses to their uncertain environment. Today, this indigenous way of flexibly institutionalizing access rules could provide blueprints for dealing with uncertainty issues resulting from global change as well as designing practical guidelines for implementing resilient management. However, transforming indigenous skills for developing institutional flexibility into operational management rules that are appropriate in the current environmental and socioeconomic context is a huge challenge. However, communities could easily...
Tipo: Peer-Reviewed Reports
Palavras-chave: Environment; Indigenous knowledge; Management; Modeling; Participation; Sahel; Senegal; Uncertainty.
Ano: 2013

Global-Scale Patterns of Forest Fragmentation
Provedor de dados: 7
Autores: Riitters, Kurt; U.S. Forest Service; kriitters@fs.fed.us; Wickham, James D; U.S. Environmental Protection Agency, National Exposure Research Laboratory; wickham.james@epa.gov; O'Neill, Robert; ; eoneill@attglobal.net; Jones, K. Bruce; U.S. Environmental Protection Agency, National Exposure Research Laboratory; jones.bruce@epa.gov; Smith, Elizabeth; U.S. Environmental Protection Agency, National Exposure Research Laboratory; smith.betsy@epa.gov.
We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 x 9 pixels, &amp;#8220;small&amp;#8221; scale) to 59,049 km 2 (243 x 243 pixels, &amp;#8220;large&amp;#8221; scale) were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined) from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents,...
Tipo: Peer-Reviewed Reports
Palavras-chave: Biogeography; Edge effect; Forest fragmentation; Geographic information systems; Global patterns; Land-cover map; Landscape ecology; Modeling; Perforated forest; Remote sensing; Satellite imagery; Spatial pattern.
Ano: 2000

Sustainable Land-use Practices in European Mountain Regions under Global Change: an Integrated Research Approach
Provedor de dados: 7
Autores: Huber, Robert; Swiss Federal Research Institute WSL ; robert.huber@wsl.ch; Bugmann, Harald; ETH Zurich; harald.bugmann@env.ethz.ch; Rigling, Andreas; Swiss Federal Research Institute WSL; andreas.rigling@wsl.ch.
This Special Feature on sustainable land-use practices in European mountain regions presents results from the inter- and transdisciplinary research project MOUNTLAND. The goal was to investigate the sensitivity of the provision of ecosystem services to both climatic and land-use changes and to suggest alternative policies and governance structures for mitigating the impact of such changes and enhancing sustainable management practices in mountain regions. The individual articles provide: (1) new scientific findings regarding the impacts of climate and land-use changes on ecosystem processes in three sensitive mountain regions of Switzerland; (2) an assessment of the feedback effects arising from changing socioeconomic and political conditions, land use,...
Tipo: Peer-Reviewed Reports
Palavras-chave: Adaptation; Climate change; Ecosystem services; Experiments; Interdisciplinary research; Land-use change; Management; Modeling; Transdisciplinary research.
Ano: 2013

Of Models and Meanings: Cultural Resilience in Social&amp;#8211;Ecological Systems
Provedor de dados: 7
Autores: Crane, Todd A.; Technology and Agrarian Development, Wageningen University; todd.crane@wur.nl.
Modeling has emerged as a key technology in analysis of social&amp;#8211;ecological systems. However, the tendency for modeling to focus on the mechanistic materiality of biophysical systems obscures the diversity of performative social behaviors and normative cultural positions of actors within the modeled system. The fact that changes in the biophysical system can be culturally constructed in different ways means that the perception and pursuit of adaptive pathways can be highly variable. Furthermore, the adoption of biophysically resilient livelihoods can occur under conditions that are subjectively experienced as the radical transformation of cultural systems. The objectives of this work are to: (1) highlight the importance of understanding the place...
Tipo: Peer-Reviewed Insight
Palavras-chave: Adaptation; Agropastoralism; Climate change; Mali; Modeling; Resilience.
Ano: 2010

Can Road-Crossing Structures Improve Population Viability of an Urban Gliding Mammal?
Provedor de dados: 7
Autores: Taylor, Brendan D.; Southern Cross University; Griffith University; brendan.taylor@scu.edu.au; Goldingay, Ross L.; Southern Cross University; ross.goldingay@scu.edu.au.
Tree-dwelling mammals are potentially highly vulnerable to discontinuities in habitat created by roads. We used population modeling to assess the viability of a metapopulation of Australia&amp;#8217;s largest gliding marsupial, the greater glider (Petauroides volans), occurring in forest remnants in the fastest-urbanizing region of Australia, where habitat is dissected by major roads. Crossing structures for arboreal mammals (consisting of a land bridge with wooden poles for gliding and adjacent rope canopy bridges) have been installed over an arterial road that separates two of these remnants (one large, one small). It is currently unknown whether this species will use the crossing structures, but available tree height and spacing do not allow a glide...
Tipo: Peer-Reviewed Reports
Palavras-chave: Crossing structures; Gliding mammals; Modeling; Motorways; Population viability analysis.
Ano: 2009

Open Source and Open Content: a Framework for Global Collaboration in Social-Ecological Research
Provedor de dados: 7
Autores: Schweik, Charles; University of Massachusetts, Amherst; cschweik@pubpol.umass.edu; Evans, Tom; Indiana University; evans@indiana.edu; Grove, J. Morgan; U.S. Forest Service, Northeastern Research Station; mgrove@fs.fed.us.
This paper discusses opportunities for alternative collaborative approaches for social-ecological research in general and, in this context, for modeling land-use/land-cover change.  In this field, the rate of progress in academic research is steady but perhaps not as rapid or efficient as might be possible with alternative organizational frameworks.  The convergence of four phenomena provides new opportunities for cross-organizational collaboration: (1) collaborative principles related to "open source" (OS) software development, (2) the emerging area of "open content" (OC) licensing, (3) the World Wide Web as a platform for scientific communication, and (4) the traditional concept of peer review. Although private individuals, government organizations, and...
Tipo: Peer-Reviewed Reports
Palavras-chave: Land use; Land cover; Modeling; Open content; Free/libre software; Open source software.
Ano: 2005

Challenges in adaptive management of riparian and coastal ecosystems
Provedor de dados: 7
Autores: Walters, Carl; University of British Columbia; c.walters@fisheries.ubc.ca.
Many case studies in adaptive-management planning for riparian ecosystems have failed to produce useful models for policy comparison or good experimental management plans for resolving key uncertainties. Modeling efforts have been plagued by difficulties in representation of cross-scale effects (from rapid hydrologic change to long-term ecological response), lack of data on key processes that are difficult to study, and confounding of factor effects in validation data. Experimental policies have been seen as too costly or risky, particularly in relation to monitoring costs and risk to sensitive species. Research and management stakeholders have shown deplorable self-interest, seeing adaptive-policy development as a threat to existing research programs and...
Tipo: Peer-Reviewed Reports
Palavras-chave: Adaptive management; Coastal ecosystems; Ecosystem management; Fisheries; Institutional barriers; Management experiments; Modeling; Riparian ecosystems; Simulation.
Ano: 1997

Land-use regime shifts: an analytical framework and agenda for future land-use research
Provedor de dados: 7
Autores: Ramankutty, Navin; Liu Institute for Global Issues; Institute for Resources, Environment, and Sustainability, University of British Columbia; navin.ramankutty@ubc.ca; Coomes, Oliver T.; Department of Geography, McGill University; oliver.coomes@mcgill.ca.
A key research frontier in global change research lies in understanding processes of land change to inform predictive models of future land states. We believe that significant advances in the field are hampered by limited attention being paid to critical points of change termed land-use regime shifts. We present an analytical framework for understanding land-use regime shifts. We survey historical events of land change and perform in-depth case studies of soy and shrimp development in Latin America to demonstrate the role of preconditions, triggers, and self-reinforcing processes in driving land-use regime shifts. Whereas the land-use literature demonstrates a good understanding of within-regime dynamics, our understanding of the drivers of land-use regime...
Tipo: Peer-Reviewed Insight
Palavras-chave: Land-cover change; Land-use change; Latin America; Modeling; Prediction; Regime shifts.
Ano: 2016

Online Publication Enhances Integration of Current Research in the Classroom
Provedor de dados: 7
Autores: Drew, C. Ashton; North Carolina State University; cadrew@unity.ncsu.edu; Hess, George R; North Carolina State University; george_hess@ncsu.edu.
Integrating current research materials and issues into graduate courses provides students with exposure to emerging concepts and methods. New online journal formats that allow authors to include raw data and model code provide a unique opportunity to bring current research into the classroom. We developed a graduate-level landscape ecology assignment using data and code provided as appendices to an article in Conservation Ecology. Our assignment required students to engage actively with the published material, was positively reviewed by the students, and prompted valuable discussion.
Tipo: Peer-Reviewed Reports
Palavras-chave: Inquiry-guided learning; Landscape ecology; Modeling; Problem-based learning; Teaching.
Ano: 2003

Applying Landscape Science to Natural Resource Management
Provedor de dados: 7
Autores: Robinson , Guy  M; Centre for Regional Engagement, University of South Australia; Guy.Robinson@unisa.edu.au; Carson, Doris A; Centre for Regional Engagement, University of South Australia; doris.carson@unisa.edu.au.
Tipo: Peer-Reviewed article
Palavras-chave: Australia; Landscape science; Modeling; Natural resource management (NRM); Stakeholder integration.
Ano: 2013

Sustainable Land Use in Mountain Regions Under Global Change: Synthesis Across Scales and Disciplines
Provedor de dados: 7
Autores: Huber, Robert; Swiss Federal Institute for Forest, Snow and Landscape Research WSL; robert.huber@wsl.ch; Rigling, Andreas; Swiss Federal Institute for Forest, Snow and Landscape Research WSL; andreas.rigling@wsl.ch; Bebi, Peter; WSL Institute for Snow and Avalanche Research SLF; bebi@slf.ch; Brand, Fridolin Simon; Natural and Social Science Interface, Department of Environmental Systems Science, ETH Zurich; fridolin.brand@env.ethz.ch; Briner, Simon; Agri-food and Agri-environmental Economics Group, Department of Environmental Systems Science, ETH Zurich; briners@ethz.ch; Hirschi, Christian; Environmental Policy and Economics, Department of Environmental Systems Science, ETH Zurich; christian.hirschi@env.ethz.ch; Lischke, Heike; Swiss Federal Institute for Forest, Snow and Landscape Research WSL;; Scholz, Roland Werner; Natural and Social Science Interface, Department of Environmental Systems Science, ETH Zurich; roland.scholz@env.ethz.ch; Seidl, Roman; Natural and Social Science Interface, Department of Environmental Systems Science, ETH Zurich; roman.seidl@env.ethz.ch; Walz, Ariane; Potsdam Institute for Climate Impact Research PIK; Institute for Earth and Environmental Science, University of Potsdam;; Zimmermann, Willi; Environmental Policy and Economics, Department of Environmental Systems Science, ETH Zurich;; Bugmann, Harald; Forest Ecology, Department of Environmental Systems Science, ETH Zurich; harald.bugmann@env.ethz.ch.
Mountain regions provide essential ecosystem goods and services (EGS) for both mountain dwellers and people living outside these areas. Global change endangers the capacity of mountain ecosystems to provide key services. The Mountland project focused on three case study regions in the Swiss Alps and aimed to propose land-use practices and alternative policy solutions to ensure the provision of key EGS under climate and land-use changes. We summarized and synthesized the results of the project and provide insights into the ecological, socioeconomic, and political processes relevant for analyzing global change impacts on a European mountain region. In Mountland, an integrative approach was applied, combining methods from economics and the political and...
Tipo: Peer-Reviewed Synthesis
Palavras-chave: Adaptive management; Climate change; Ecosystem services; Experiments; Interdisciplinary research; Land-use change; Modeling; Transdisciplinary research.
Ano: 2013

Mechanisms Affecting Population Density in Fragmented Habitat
Provedor de dados: 7
Autores: Tischendorf, Lutz; ELUTIS Modelling and Consulting Inc.; lutz.tischendorf@gmx.net; Grez, Audrey; Universidad de Chile; agrez@uchile.cl; Fahrig, Lenore; Carleton University; lfahrig@ccs.carleton.ca.
We conducted a factorial simulation experiment to analyze the relative importance of movement pattern, boundary-crossing probability, and mortality in habitat and matrix on population density, and its dependency on habitat fragmentation, as well as inter-patch distance. We also examined how the initial response of a species to a fragmentation event may affect our observations of population density in post-fragmentation experiments. We found that the boundary-crossing probability from habitat to matrix, which partly determines the emigration rate, is the most important determinant for population density within habitat patches. The probability of crossing a boundary from matrix to habitat had a weaker, but positive, effect on population density. Movement...
Tipo: Peer-Reviewed Reports
Palavras-chave: Boundary crossing; Emigration; Habitat fragmentation; Immigration; Modeling; Movement; Population density; Simulation; Time scale.
Ano: 2005

Simulating Oil Palm Expansion Requires Credible Approaches that Address Real Issues
Provedor de dados: 7
Autores: Dudley, Richard G; Independent Researcher; richard.dudley@attglobal.net; Sheil, Douglas; CIFOR (Center for International Forestry Research); d.sheil@cgiar.org; Colfer, Carol; CIFOR (Center for International Forestry Research); c.colfer@cgiar.org.
Tipo: Peer-Reviewed Response
Palavras-chave: East Kalimantan; Indonesia; Modeling; Oil palm; System dynamics.
Ano: 2008

Treatment of low strength sewage with high suspended organic matter content in an anaerobic sequencing batch reactor and modeling application
Provedor de dados: 69
Autores: Donoso-Bravo,Andrés; Carballa,Marta; Ruiz- Filippi,Gonzalo; Chamy,Rolando.
In this work, an anaerobic sequencing batch reactor (ASBR) was operated for 8 months to treat low strength sewage with high suspended organic matter content. Three phases of operation with increasing organic loading rates (OLR) were performed: 0.4 kg COD/m³ x d (phase I), 0 .8 kg COD/m³ x d (phase II) and 1.2 kg COD/m³ x d (phase III). Adequate stability parameters (pH, total alkalinity) were obtained through all three experimental phases. During phases I and II, the removal efficiencies of organic matter (expressed as total chemical oxygen demand (COD) and total suspended solids ranged between 50-60%. However, these values decreased to 15-25% in phase III. In addition, a non-complex model, including hydrolysis, acidogenesis and methanogenesis, was applied...
Tipo: Journal article
Palavras-chave: Acidogenesis; Anaerobic treatment; Hydrolysis; Low strength wastewater; Modeling.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000300013

DEFORMATION OF PEACHES SUBMITTED TO CYCLIC LOADING USING THE DISCRETE ELEMENT METHOD
Provedor de dados: 70
Autores: Pinto,Eduardo M.; Ferraz,Antonio C. de O.
ABSTRACT This study aimed to use and validate a simple contact force model that describes the behavior of peaches stored in a wooden box, loaded cyclically, by using the discrete element method. The Kelvin-Voigt contact force model was used and the cyclic loading in the simulation was performed with an amplitude of 1 mm and frequency of 12 Hz for time intervals of 3600, 5400, and 7200 s. The laboratory test was performed with a peach box attached to a vibrating table by applying the same excitation conditions used in the simulation. For validation, model results were compared with those from the laboratory test by using deformation values of fruits in the contact regions. To measure this deformation, we adapted the methodology for determining the radius of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Simulation; Post-harvest; Prunus persica (L.) Batsch.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000300434

The use of ALOS/PALSAR data for estimating sugarcane productivity
Provedor de dados: 70
Autores: Picoli,Michelle C. A.; Lamparelli,Rubens A. C.; Sano,Edson E.; Rocha,Jansle V.
Some models have been developed using agrometeorological and remote sensing data to estimate agriculture production. However, it is expected that the use of SAR images can improve their performance. The main objective of this study was to estimate the sugarcane production using a multiple linear regression model which considers agronomic data and ALOS/PALSAR images obtained from 2007/08, 2008/09 and 2009/10 cropping seasons. The performance of models was evaluated by coefficient of determination, t-test, Willmott agreement index (d), random error and standard error. The model was able to explain 79%, 12% and 74% of the variation in the observed productions of the 2007/08, 2008/09 and 2009/10 cropping seasons, respectively. Performance of the model for the...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Synthetic aperture radar; L-band; Modeling; Remote sensing.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000600019

Validation study of an overall radiation balance estimation method under Ponta Grossa (PR) Brazil weather conditions
Provedor de dados: 70
Autores: Beruski,Gustavo C.; Pereira,André B.
Radiation balance is the fraction of incident solar radiation upon earth surface which is available to be used in several natural processes, such as biological metabolism, water loss by vegetated surfaces, variation of temperature in farming systems and organic decomposition. The present study aimed to assess and validate the performance of two estimation models for Rn in Ponta Grossa city, Paraná State, Brazil. To this end, during the period of 04/01/2008 to 04/30/2011, from radiometric data collected by an automatic weather station set at the Experimental Station, of the State University of Ponta Grossa. We performed a linear regression study by confrontation between measurements made through radiometric balance and Rn estimates obtained from Brunt...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Overall radiation balance; Bowen ratio; Global solar radiation; Modeling; Solar radiometry.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000300010

A decision support system for cost determination in grain storage facility operations
Provedor de dados: 70
Autores: Valente,Domingos S. M.; Queiroz,Daniel M. de; Corrêa,Paulo C.; Silva,Luis C. da; Vale,Sônia M. L. R. do.
Many research works have being carried out on analyzing grain storage facility costs; however a few of them had taken into account the analysis of factors associated to all pre-processing and storage steps. The objective of this work was to develop a decision support system for determining the grain storage facility costs and utilization fees in grain storage facilities. The data of a CONAB storage facility located in Ponta Grossa - PR, Brazil, was used as input of the system developed to analyze its specific characteristics, such as amount of product received and stored throughout the year, hourly capacity of drying, cleaning, and receiving, and dispatch. By applying the decision support system, it was observed that the reception and expedition costs were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Costs; Modeling; Software.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162011000400012

SIMULATION OF SODIUM AND POTASSIUM DYNAMICS BY THE HYDRUS 2D MODEL IN A HAPLIC PLANOSOL VIA RESIDUE WATER
Provedor de dados: 70
Autores: Andrade,Carolyne W. L. de; Montenegro,Suzana M. G. L.; Miranda,Jarbas H. de; Montenegro,Abelardo A. de A.; Assis,Fred M. C. V. de.
ABSTRACT The application of chemical substances to the soil together with little attention given to the possible environmental impacts, transformed the environment into a recipient of waste. The aim of this study was to simulate the movement of water and solutes (sodium and potassium together) using the STANMOD and HYDRUS-2D models in a typical Haplic Planosol under the application of wastewater via surface irrigation under different flow rates. The experiment was conducted in the laboratory by miscible displacement tests, first using columns with deformed soil under saturation and steady water flow conditions, at a rate of 11.7 cm3 min-1, to obtain transport parameters of sodium and potassium ions, and in the applied residual water, the values of 475 and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Nutrients; Soil physical properties; Water reuse.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000600874

REFERENCE EVAPOTRANSPIRATION FORECASTING BY ARTIFICIAL NEURAL NETWORKS
Provedor de dados: 70
Autores: Alves,Walison B.; Rolim,Glauco de S.; Aparecido,Lucas E. de O.
ABSTRACT: Evapotranspiration (ET) is the main component of water balance in agricultural systems and the most active variable of the hydrological cycle. In the literature, few studies have used the forecast the day before via Artificial Neural Networks (ANNs) for the northern region of São Paulo state, Brazil. Therefore, this aimed to predict the reference evapotranspiration for Jaboticabal, the major sugarcane-producing region of São Paulo state. We used a historical series of data on average air temperature, wind speed, net radiation, soil heat flux, and daily relative humidity from 2002 to 2012, for Jaboticabal, SP (Brazil). ET was estimated by Penman-Monteith method. To forecast reference evapotranspiration, we used a feed-forward Multi-Layer...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Multi-Layer Perceptron; Air temperature; Estimate.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000601116

SIMANIHOT: A PROCESS-BASED MODEL FOR SIMULATING GROWTH, DEVELOPMENT AND PRODUCTIVITY OF CASSAVA
Provedor de dados: 70
Autores: Tironi,Luana F.; Streck,Nereu A.; Gubiani,Paulo I.; Benedetti,Rômulo P.; Freitas,Charles P. de O. De.
ABSTRACT The objective of this study was to propose a model, named Simanihot, for simulating growth, development and yield of tuberous roots in cassava, with a choice of two soil water balance models. The model works on a day time step and is calibrated for five cassava cultivars (Fepagro –RS 14, Estrangeira, Cascuda, São José e Paraguaia), with different branching habits and different purpose of use (pasture, food and industry). The model has a graphical interface, where the user can choose one out of two soil water balance models, depending upon the number of known soil variables and details the user wants to know about soil water content.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Manihot esculenta; Modeling; Software; Soil water balance.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000300471

RESISTANCE OF A RED LATOSOL TO PENETRATION: COMPARISON OF PENETROMETERS, MODEL ADJUSTMENT, AND SOIL WATER CONTENT CORRECTION
Provedor de dados: 70
Autores: Duarte,Thiago F.; Silva,Tonny J. A. da; Bonfim-Silva,Edna M.; Fenner,Willian.
ABSTRACT Penetration resistance can be determined directly in the field or in the laboratory. However, data obtained using the two methods are not directly comparable. Considering soil moisture influences penetration resistance, penetration resistance data obtained using the two methods can be corrected based on common moisture values. To enable comparison of the data, the measured data should be adjusted using mathematical models. Consequently, the objective of the present study was to compare soil penetration resistance values measured in a Red Latosol using a static penetrometer and a bench-top electronic penetrometer. The comparison was carried out using samples collected from different soil layers, based on moisture levels ranging from 0.15 to 0.28 kg...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil physics; Soil mechanical; Soil compaction; Modeling.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400462

Auger-type granular fertylizer distributor: matemathical model and dynamic simulation
Provedor de dados: 70
Autores: Garcia,Angel P.; Cappelli,Nelson L.; Umezu,Claudio K.
The objective of this study was to model mathematically and to simulate the dynamic behavior of an auger-type fertilizer applicator (AFA) in order to use the variable-rate application (VRA) and reduce the coefficient of variation (CV) of the application, proposing an angular speed controller θ' for the motor drive shaft. The input model was θ' and the response was the fertilizer mass flow, due to the construction, density of fertilizer, fill factor and the end position of the auger. The model was used to simulate a control system in open loop, with an electric drive for AFA using an armature voltage (V A) controller. By introducing a sinusoidal excitation signal in V A with amplitude and delay phase optimized and varying θ' during an operation cycle, it is...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Seeder fertilizer drill; Modeling; Precision agriculture.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000100016

MODELING AND TESTING OF AN ICE BANK FOR MILK COOLING AFTER MILKING
Provedor de dados: 70
Autores: Jordan,Rodrigo A.; Cortez,Luís A. B.; Silveira Jr.,Vivaldo; Cavalcanti- Mata,Mário E. R. M.; Oliveira,Fellipe D. de.
ABSTRACT Based on mass and energy balance equations and data collected in specialized bibliographies, it was proposed a methodology for modeling of an ice bank for thermal storage of energy at low temperature to be used in milk cooling. The data obtained by the equations arrangement were used in the design and installation of a real system, which was tested to collect data and to compare it with the estimated. The data obtained in terms of prediction of ice formation, temperature of the ice bank, water and capacity of the selected refrigeration system prove the adequacy of the equations arrangement, showing that it can be used as a tool for sizing solid ice bank in smooth pipe coils, with good approximation.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Milk cooling; Modeling; Thermal storage.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000400510

MODELING OF THE KINETICS OF CRYOGENIC FREEZING OF LIMA BEAN SEEDS AS A FUNCTION OF INITIAL WATER CONTENT
Provedor de dados: 70
Autores: Luciano,Karina M da F.; Mata,Mario E. R. M. Cavalcanti; Fortes,Mauri; Duarte,Maria E. M.
ABSTRACT Cryopreservation is a technique used to preserve genetic material at ultra-low temperatures in cryogenic germplasm banks. In order to enable the cryopreservation of a seed, it is necessary to study its appropriate freezing temperature and its water content, because seeds reach maximum physiological quality with high water contents, and they tolerate drying when they are orthodox seeds, but they may not tolerate cryopreservation. Therefore, the objective of this study was to analyze the influence of initial water content (50 to 10% wet basis) on the kinetic behavior of the lima bean seed at the temperature of −150 °C, in addition to determining changes in its physiological quality (germination and vigor) when cryopreserved (−150 °C) for 30 days...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phaseolus lunatus; Cryogenic; Modeling; Germplasm bank.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000300331

THE ROLE OF CHAR FORMATION IN EQUILIBRIUM MODELING OF GASIFICATION PROCESSES
Provedor de dados: 70
Autores: Ramos,Vinícius F.; Costa Junior,Esly F. da; Costa,Andréa O. S. da.
ABSTRACT This work aims to develop and validate a model based on chemical equilibrium to predict the composition of syngas produced by gasification of woody biomass (sawdust). The model uses Gibbs Energy minimization to evaluate the composition of the system in chemical equilibrium. The results are validated by comparison between experimental data from a gasification experiment and those of other similar models in the literature. The study shows good agreement among experimental results and elucidates the role of solid unburned carbon in such systems, which is present in considerable amount. It can be concluded that equilibrium models can be used to predict carbon conversion in gasification systems.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Char formation; Gasification; Gibbs energy minimization; Modeling.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200139

Terceira validação do CalcMadeira: desbobro pelo método radial.
Provedor de dados: 14
Autores: RAMOS, L. B.; COSTA, T. C. e C. da.
Nas operações para obter madeira serrada muitos são os métodos usados para desdobro da tora, que podem ser padrões de corte ou processos empíricos, usando a experiência dos operadores. Como usualmente o produtor vende a árvore em pé, com valores muito inferiores àqueles que serão obtidos após o processamento mecânico da madeira, foi desenvolvido o CalcMadeira, software com a finalidade de auxiliar o produtor a vender a arvore não em metros cúbicos, mas em função das peças serradas que podem ser obtidas a partir de árvores. Um dos modelos implementados é o padrão de corte radial, que consiste em dividir a tora em quadrantes, e calcular peças serradas próximas ao sentido do raio. Foram realizados testes com diferentes deslocamentos da medula em relação ao...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Software; Extração de madeira; Multiprodutos; Modelagem; Manejo florestal; Sawmill; Modeling; Madeira; Produto Florestal; Serraria; Forest management.
Ano: 2021
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1135677

Modelagem e solução numérica de sistemas biológicos utilizando ferramentas open source.
Provedor de dados: 14
Autores: SILVA, R. de O.; TERNES, S.
A modelagem matemática desempenha um importante papel na pesquisa biológica. Uma vez que o sistema estudado é representado em linguagem matemática, torna-se possível prever seu comportamento por meio de simulações. Nesse contexto, surge a necessidade do uso de softwares robustos, capazes de computar, construir gráficos, resolver sistemas e equações, assim como gerar aproximações numéricas. Existe, no mercado, uma infinidade de softwares matemáticos, sistemas computacionais numéricos e algébricos e ferramentas de simulação. Há produtos comerciais muito utilizados pela comunidade científica como Mathematica (WOLFRAM, 1999) e Matlab (THE MATHWORKS, 1998), e softwares não comerciais que podem ser utilizados como alternativa às ferramentas proprietárias. Além...
Tipo: Comunicado Técnico (INFOTECA-E)
Palavras-chave: Modelagem matemática; Sistemas biológicos; Ferramentas open source; Modeling; Simulation.; Simulação.
Ano: 2010
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/885653

Modelo de balanço de nitrogênio para a cana-de-açúcar fase II - construção de modelo software STELLA.
Provedor de dados: 14
Autores: BERGAMASCO, A. F.; SILVA, F. C. da; RODRIGUES, L. H. A.; TRIVELIN, P. C. O.
A cultura da cana-de-açúcar vem sofrendo mudanças, de âmbitos tecnológicos e sociais, profundas nesta década, procurando se adaptar às demandas de produção com alta produtividade, competitividade e respeito ao meio ambiente. Apesar de o Brasil ser o maior produtor mundial de cana-de-açúcar, ainda pratica a queima da palha do canavial para facilitar a colheita, o que gera prejuízos econômicos, sociais e ambientais. Sem essa queima (Decreto n.° 42056 do Estado de SP), a cobertura do solo pela palhada irá provocar significativas mudanças no manejo da cultura e na dinâmica do nitrogênio. Dada a complexibilidade do ciclo de nitrogênio no solo, seus vários caminhos de transformação, e as variações climáticas, é difícil a determinação do melhor manejo do...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Cana-de-açucar; Adubação nitrogenda; Software ESTELLA; Modelagem matemática; Modeling; Sugar cane.; Modelo Matemático.
Ano: 2002
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/8690

Agroclimatic modeling as an agricultural research tool.
Provedor de dados: 14
Autores: GARAGORRY, F. L.; PORTO, E. R.
The paper illustrates the use of an agro-climatic model so as to suggest agricultural research priorities. More generally, some of the main aspects of the modeling activity, as it is being conducted at EMBRAPA (the Brazilian Public Corporation for Agricultural Reearch) will be discussed.
Tipo: Fôlder / Folheto / Cartilha (INFOTECA-E)
Palavras-chave: Agro-climatic; Modeling; Clima; Climatologia; Modelo Matemático; Pesquisa; Climate; Research.
Ano: 1981
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/132110

Spatial, Ecological and Social Dimensions of Assessments for Bivalve Farming Management
Provedor de dados: 5
Autores: Bacher, Cedric; Gangnery, Aline; Cugier, Philippe; Mongruel, Remi; Strand, Oivind; Frangoudes, Katia.
The general purpose of assessment is to provide decision-makers with the best valuable data, information, and predictions with which management decisions will be supported. Using case studies taken from four scientific projects and dealing with the management of marine bivalve resources, lessons learned allowed identifying some issues regarding assessment approaches. The selected projects also introduced methodological or institutional frameworks: ecosystem approach to aquaculture (EAA), system approach framework (SAF), marine spatial planning (MSP), and valuation of ecosystem services (ES). The study on ecosystem services linked ES to marine habitats and identified ES availability and vulnerability to pressures. The results were displayed as maps of...
Tipo: Text
Palavras-chave: Ecosystem services; Marine spatial planning; Ecosystem approach to aquaculture; System approach; Modeling; Stakeholder involvement.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00470/58138/60608.pdf

Spéciation des contaminants métalliques en milieu estuarien : Intérêt de la modélisation et application au cadmium
Provedor de dados: 5
Autores: Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte.
In estuarine environment, cadmium has a nonconservative behavior. It can be present under various species: dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated), or integrated by various mechanisms in the organisms. This distribution is the result of processes (physical, chemical and biological) which are controlled by many factors (salinity, pH, Eh, nature and concentration of suspended matter, primary production). Geochemical modeling is a very useful approach to understand the dynamics of this type of contaminant, especially in the complex systems which are the estuaries. A speciation model was used to simulate the measurements taken (dissolved and particulate Cd) during various cruises carried out in the...
Tipo: Text
Palavras-chave: Cadmium; Estuary; Speciation; Modeling; Surface complexation; Cadmium; Estuaire; Spéciation; Modélisation; Complexation de surface.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00480/59120/61749.pdf

Cable length optimization for trawl fuel consumption reduction
Provedor de dados: 5
Autores: Khaled, Ramez; Priour, Daniel; Billard, Jean-yves.
A numerical method for optimization of the cable lengths in trawls with respect to the ratio between the estimated trawl drag and the predicted catch efficiency is developed and applied. The trawl cables of interest are warps, bridles, headline and footrope. The optimization algorithm applies an ordered sequential process changing one cable length at the time. It is assumed in the predictions that the catch efficiency of the trawl is proportional with the trawl mouth area. In a case study optimizing a bottom trawl used on a research vessel by applying the new method it is predicted that it would be possible to reduce the ratio between trawl drag and catch efficiency by up to 46% by optimizing the cable lengths. Thus this would enable a considerable...
Tipo: Text
Palavras-chave: Bottom trawl; Modeling; Optimization; Fuel consumption; Drag; Swept area; Mouth surface; Fish distribution.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00130/24106/22857.pdf

Impact of urban effluents on summer hypoxia in the highly turbid Gironde Estuary, applying a 3D model coupling hydrodynamics, sediment transport and biogeochemical processes
Provedor de dados: 5
Autores: Lajaunie-salla, Katixa; Wild-allen, Karen; Sottolichio, Aldo; Thouvenin, Benedicte; Litrico, Xavier; Abril, Gwenael.
Estuaries are increasingly degraded due to coastal urban development and are prone to hypoxia problems. The macro-tidal Gironde Estuary is characterized by a highly concentrated turbidity maximum zone (TMZ). Field observations show that hypoxia occurs in summer in the TMZ at low river flow and a few days after the spring tide peak. In situ data highlight lower dissolved oxygen (DO) concentrations around the city of Bordeaux, located in the upper estuary. Interactions between multiple factors limit the understanding of the processes controlling the dynamics of hypoxia. A 3D biogeochemical model was developed, coupled with hydrodynamics and a sediment transport model, to assess the contribution of the TMZ and the impact of urban effluents through wastewater...
Tipo: Text
Palavras-chave: Hypoxia; TMZ; Gironde Estuary; Wastewater; Oxygen; Modeling.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00388/49903/50475.pdf

Water diffusivity in PA66: Experimental characterization and modeling based on free volume theory
Provedor de dados: 5
Autores: Broudin, M.; Le Gac, Pierre-yves; Le Saux, V.; Champy, C.; Robert, G.; Charrier, P.; Marco, Y.
Diffusion of water in polyamide 6.6 has been characterized for a wide range of temperatures (from 25 to 80 °C) and various humidities using dynamic vapor sorption machine. The decrease in glass transition temperature (Tg) has also been measured using DMA tests. As usually observed, PA66 absorbs a large amount of water (up to 5% at 90%RH) with a Fickian behavior with a diffusion coefficient that depends on water activity for all temperatures. Moreover, it appears that the diffusion coefficient for tests performed below Tg is almost independent of the water activity whereas a strong dependency is observed above Tg. This behavior is to be compared to a large decrease of Tg with the absorption of water. The increase of the water diffusion can therefore be...
Tipo: Text
Palavras-chave: Water absorption; Free volume; Polyamide; Modeling.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00260/37148/35794.pdf

Modeling of Faecal Contamination in Water from Catchment to Shellfish Growing Area
Provedor de dados: 5
Autores: Bougeard, Morgane; Le Saux, Jean-claude; Perenne, Nicolas; Le Guyader, Soizick; Pommepuy, Monique.
During rainstorms, watersheds can introduce large amounts of faecal pollution into the rivers and sea, leading to shellfish contamination. In this study, we assessed Escherichia coli fluxes from a catchment, and their impact on estuarine water quality, using two assembled models. For the catchment, the agro-hydrological model SWAT was implemented integrating land uses, soil, topography, rainfall and other climatic data on Daoulas watershed (France). Initially, the SWAT model was calibrated and validated for river flow rates, and results were found satisfactory. Subsequently, different faecal contamination sources were integrated into the model: point sources (WWTP discharges into rivers) and non-point sources (manure spreading on fields). During rainfall...
Tipo: Text
Palavras-chave: Modeling; SWAT; MARS; E. coli; Shellfish; Catchment; Estuary.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00066/17748/15270.pdf

Plastic debris occurrence, convergence areas and fin whales feeding ground in the Mediterranean Marine Protected Area Pelagos Sanctuary: a modelling approach
Provedor de dados: 5
Autores: Fossi, Maria Cristina; Romeo, Teresa; Panti, Matteo; Marsili, Letizia; Campani, Tommaso; Canese, Simonepietro; Galgani, Francois; Druon, Jean-noël; Airoldi, Sabina; Taddei, Stefano; Fattorini, Maria; Brandini, Carlo; Lapucci, Chiara.
The Mediterranean Sea is greatly affected by marine litter. In this area, research on the impact of plastic debris (including microplastics) on biota, particularly large filter-feeding species such as the fin whale (Balaenoptera physalus), is still in its infancy. We investigated the possible overlap between microplastic, mesoplastic and macrolitter accumulation areas and the fin whale feeding grounds in in a pelagic Specially Protected Area of Mediterranean Importance (SPAMI): the Pelagos Sanctuary. Models of ocean circulation and fin whale potential habitat were merged to compare marine litter accumulation with the presence of whales. Additionally, field data on microplastics, mesoplastics and macrolitter abundance and cetacean presence were...
Tipo: Text
Palavras-chave: Floating plastic debris; Microplastics; Mediterranean Sea; Convergence areas; Modeling; Fin whales; Marine Protected Area.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00386/49763/50356.pdf

Impact des mesures de gestion sur la dynamique de la pêcherie pélagique du golfe de Gascogne : Quelles certitudes ? Quels descripteurs ?
Provedor de dados: 5
Autores: Lehuta, Sigrid.
Quantitative evaluations of management measure impact on resource and fleet viability are required to provide diagnostics and feed decision process. Fisheries are complex systems where numerous dynamics interact at various spatial and temporal scales. This complexity and the difficulty to observe marine systems are responsible for the high uncertainty surrounding fishery functioning that makes it hard to identify adequate management measures. The increasing consideration of uncertainties in diagnostics argues in favor of robust management measures rather than optimal management measures. Identifying robust management measures requires the development of models that account for complexity and uncertainty in the description and prediction of management...
Tipo: Text
Palavras-chave: Modélisation; Pêcherie mixte; Gestion des pêcheries; Incertitudes; Simulation; Analyse de sensibilité; Indicateurs; Gestion spatialisée; ISIS-Fish; Modeling; Mixed fisheries; Fishery management; Uncertainty; Simulation; Sensitivity analysis; Indicators; Spatialised management; ISIS-Fish.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00025/13630/10712.pdf

Evolution model for the Absheron mud volcano: from in-situ observations to numerical modeling
Provedor de dados: 5
Autores: Blouin, Arthur; Imbert, Patrice; Sultan, Nabil; Callot, Jean-paul.
The morphology of mud volcanoes (MV) has been extensively studied over the last few decades. Although recent research has begun to focus on deep processes and structures, little is known about mud generation mechanisms. This study aims to investigate the feeder system and formation of an active kilometer‐scale MV by relying on a 3‐D seismic survey and an in‐situ dataset on the Absheron anticline (South Caspian Basin). Seismic data show a depleted area in the Anhydritic Surakhany Formation (ASF), whose mineralogical composition fits with surface mud. Well data show that the ASF is a succession of evaporitic beds and low temperature shales near its fracture pressure. Biostratigraphic analysis confirms a Pliocene origin for the mud, suggesting that the ASF...
Tipo: Text
Palavras-chave: Mud volcano; Pore pressure; Methane; Modeling; Seismic.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00481/59304/62057.pdf

Contributions to the Coordinated Control of Two Robotic Arms for Underwater Manipulation of Deformable Biological Specimens
Provedor de dados: 5
Autores: Leborne, Francois.
The research carried out in the scope of this doctorate degree aims to develop innovative techniques to improve the collection of biological and mineral samples underwater using robotic manipulators. The end goal is to enhance the handling by robotic means in order to maximise sample quality provided to marine scientists. The proposed techniques are based on an in-depth analysis of the robotic arm actuators used in most recent underwater intervention vehicles, in order to improve the accuracy of the positionning of the tools held by the manipulator arms. An instrumented tool has also been developed with the aim to measure the reaction forces and adapt the interaction between the arm's end-effector and its environment to improve samples handling. These...
Tipo: Text
Palavras-chave: Robotique sous-marine; Manipulation; Modélisation; Identification; Mesure d'effort; Underwater Robotics; Manipulation; Modeling; Identification; Force sensing.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00498/60958/64361.pdf

A methology for the stocks assessments of cultivated oysters among along the French Atlantic coasts
Provedor de dados: 5
Autores: Bacher, Cedric; Baud, Jean-pierre; Bodoy, Alain; Deslous-paoli, Jean-marc; Dreno, Jean-paul; Heral, Maurice; Maurer, Daniele; Prou, Jean.
An assessment of the reared stocks of the Pacific oyster (Crassostrea gigas ) has been recently conducted on the major French areas of molluscs culture. The methodology proposed included both estimates of densities obtained by subsampling in the field, and aerial photographs which covered the cultivated, intertidal area. The size and the number of samples were designed to reach a precision of 10% on the final assessment in each area. The field work consisted in weighing and counting the oyster in unit areas of 0.5 m2 for the bottom culture or in trays or bags, for the off bottom technique. These results give a better knowledge of the technique evolution and of the general structures in the cultivated areas.
Tipo: Text
Palavras-chave: Modeling; Estimation; Stocks; Crassostrea gigas; Oysters.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/acte-2864.pdf

Ecological-economic modelling for the sustainable management of biodiversity
Provedor de dados: 5
Autores: Doyen, Luc; Cisse, Abdoul; Gourguet, Sophie; Mouysset, L.; Hardy, Pierre-yves; Bene, Christophe; Blanchard, Fabian; Jiguet, Frederic; Pereau, J.-c.; Thebaud, Olivier.
Terrestrial and marine biodiversity provides the basis for both ecosystems functioning and numerous commodities or services that underpin human well-being. From several decades, alarming trends have been reported worldwide for both biodiversity and ecosystem services. Therefore the sustainable management of biodiversity requires a double viewpoint balancing ecological conservation with the welfare of human societies. Understanding the underlying trade-offs, synergies and interactions imposes the development of interdisciplinary researches and methods. In that respect, bio-economic or ecological economic modeling is likely to play a major role. The present paper intends to elicit the key features, strengths and challenges of bio-economic approaches...
Tipo: Text
Palavras-chave: Ecological economics; Modeling; Sustainability; Biodiversity; Public policy; Criterion; Equilibrium; Optimality; Viability.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00171/28208/26510.pdf

What causes low magnetization at basalt-hosted hydrothermal sites? Insights from inactive site Krasnov (MAR 16°38′N)
Provedor de dados: 5
Autores: Szitkar, Florent; Dyment, Jerome; Choi, Yujin; Fouquet, Yves.
High-resolution magnetic surveys acquired near the seafloor show that active basalt-hosted hydrothermal sites are associated with zones of lower magnetization. This observation may reflect the thermal demagnetization of a hot hydrothermal zone, the alteration of basalt affected by hydrothermal circulation, and/or the presence of thick, nonmagnetic hydrothermal deposits. In order to discriminate among these inferences, we acquired vector magnetic data 50 m above inactive hydrothermal site Krasnov using the Remotely Operated Vehicle (ROV) Victor. This deep hydrothermal site, located 7 km east of the Mid-Atlantic Ridge (MAR) axis at 16°38′N, is dissected by major normal faults and shows no evidence of recent hydrothermal activity. It is therefore a perfect...
Tipo: Text
Palavras-chave: Magnetic anomalies; Hydrothermalism; Alteration; Modeling.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00188/29915/28375.pdf

Larval Fish Swimming Behavior Alters Dispersal Patterns From Marine Protected Areas in the North-Western Mediterranean Sea
Provedor de dados: 5
Autores: Faillettaz, Robin; Paris, Claire B.; Irisson, Jean-olivier.
Most demersal fishes undergo a dispersal phase as larvae, which strongly influences the connectivity among adult populations and, consequently, their genetic structure and replenishment opportunities. Because this phase is difficult to observe directly, it is frequently simulated through numerical models, most of which consider larvae as passive or only vertically migrating. However, in several locations, including the Mediterranean Sea, many species have been shown to swim fast and orient. Here we use a Lagrangian model to study connectivity patterns among three Mediterranean Marine Protected Areas (MPAs) and compare simulations in which virtual larvae are passive to simulations in which oriented swimming is implemented. The parameterization of behavior...
Tipo: Text
Palavras-chave: Fish larvae; Behavior; Swimming; Connectivity; Dispersal; Mediterranean sea; Marine protected areas; Modeling.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00634/74618/74548.pdf

Simulation of a coastal jet retention process using a barotropic model
Provedor de dados: 5
Autores: Penven, Pierrick; Roy, Claude; Colin De Verdiere, Alain; Largier, John.
In the southern Benguela, sardine and anchovy spawn on the Western Agulhas Bank. Eggs and larvae are transported to the West coast nursery ground by a! coastal current. Once the larvae reach the West coast, retention within the favorable coastal domain is key to larvae survival and recruitment. The Cape Columbine-St Helena Bay area is the main nursery ground along the West Coast. In this area, the interaction between upwelling and topography results in the formation of an upwelling plume. The plume, and the associated circulation patterns, is thought to be the mechanism providing retention within the coastal domain. The dynamics of the plume are studied using a set of:numerical experiments. It is shown that an equatorward wind forcing produces a cyclonic...
Tipo: Text
Palavras-chave: Benguela; Effets de cap; Modélisation; Rétention; Recrutement; Benguela; Cape effects; Modeling; Retention; Recruitment.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00323/43385/42826.pdf

Bias in the paleoceanographic time series: Tests with a numerical model of U, C-org, and Al burial
Provedor de dados: 5
Autores: Donnadieu, Y; Lecroart, P; Anschutz, P; Bertrand, P.
We have constructed a nonsteady state numerical model of organic carbon, aluminum, and uranium burial to examine the dynamic response of sediments to variations on thousand years scale. The three components are defined by distinct behaviors in the sedimentary system. The aluminum is a conservative component, the organic carbon is a nonconservative component degraded in superficial sediment, and the uranium is a component affected by redox conditions. By introducing a simultaneous variation of incoming fluxes of C-org and Al, geochemical profiles of Al, Corg, and U clearly show separate distributions after burial. Each component record the synchronous variation of the incoming fluxes, but the position in the sedimentary pile of the recording differs from a...
Tipo: Text
Palavras-chave: Time lag; Sedimentary system; High-resolution record; Modeling; Bioturbation.
Ano: 2002
URL: https://archimer.ifremer.fr/doc/00223/33390/31872.pdf

The role of models in assessing the impact of sewage overflows on feacal water contamination
Provedor de dados: 5
Autores: Riou, Philippe; Le Saux, Jean-claude; Dumas, Franck; Le Guyader, Soizick; Le Goff, R.; Maheux, Frank; Lamort, Laure; Pommepuy, Monique.
Climate change contributes to local weather modifications such as storm events and heavy rainfall, and in particular, changes in the frequency and intensity of extreme storm and rainfall events. Observations have indicated that rainfall-runoff processes, like sewage overflow may induce fecal contamination in coastal water. Pathogens present in runoff water could therefore contaminate shellfish and be responsible for food-borne disease outbreaks. Mathematical models for this were used to predict the effect of climate modifications on shellfish quality. Using a hydrodynamic model, simulations of water quality conditions under a variety of storm event scenarios were run and are presented here for a harvesting area in France. Major storm events occurring in...
Tipo: Text
Palavras-chave: Modeling; Seawater fecal contamination; E. coli; Virus; Shellfish; Climate change.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00066/17739/15261.pdf

Etude du comportement des éléments traces en milieu estuarien : approche expérimentale et modélisation : Application à l'étude de la spéciation de Cd, Co et Cs dans les estuaires majeurs français (Seine, Loire, Gironde, Rhône)
Provedor de dados: 5
Autores: Dange, Catherine.
Most of trace elements have a non conservative behavior in estuarine environments. It is the case of cadmium, cobalt and caesium for which the fate in estuarine and coastal zones is largely controlled by their distribution between water and suspended particles, which generally have high residence times or can be definitely deposited in these areas. Metallic contaminants and radionuclides can be present under various species : dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated) or integrated by various mechanisms in the organisms. Such distributions are the result of processes (physical, chemical, biological) which are controlled by many factors (ionic strengh, pH, Eh, major cations concentration, nature and...
Tipo: Text
Palavras-chave: Modeling; French estuaries; Caesium; Cobalt; Cadmium; Radionuclides; Trace metals; Speciation; Modélisation; Estuaires français; Cesium; Cobalt; Cadmium; Radionucléides; Métal trace; Speciation.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/these-183.pdf

Dissolved Radiotracers and Numerical Modeling in North European Continental Shelf Dispersion Studies (1982–2016): Databases, Methods and Applications
Provedor de dados: 5
Autores: Bailly Du Bois, Pascal; Dumas, Franck; Voiseux, Claire; Morillon, Mehdi; Oms, Pierre-emmanuel; Solier, Luc.
Significant amounts of anthropogenic radionuclides were introduced in ocean waters following nuclear atmospheric tests and development of the nuclear industry. Dispersion of artificial dissolved radionuclides has been extensively measured for decades over the North-European continental shelf. In this area, the radionuclide measurement and release fluxes databases provided here between 1982 and 2016 represent an exceptional opportunity to validate dispersion hydrodynamic models. This work gives accessibility to these data in a comprehensive database. The MARS hydrodynamic model has been applied at different scales to reproduce the measured dispersion in realistic conditions. Specific methods have been developed to obtain qualitative and quantitative results...
Tipo: Text
Palavras-chave: Radionuclide; Tracer; Data collection; Antimony 125 (Sb-125); Tritium (H-3); Dispersion; Modeling; English Channel; North Sea; Biscay Bay.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00633/74521/74348.pdf

Mécanismes sous-jacents du contrôle bottom-up des populations de sardines dans le Golfe du Lion : enseignements tirés des expériences et de la modélisation
Provedor de dados: 5
Autores: Queiros, Quentin.
The Gulf of Lions has faced a sharp drop in the catches of its two main small pelagic exploited species, the sardine Sardina pilchardus and the anchovy Engraulis encrasicolus since the mid-2000s, despite both population abundances remaining high. This situation has been due to a severe decrease in individual body condition and size as a result of both lower growth and the disappearance of the oldest and largest individuals. While overfishing, predation or disease outbreaks have been refuted to explain this situation, one major hypothesis remained to be investigated. A potential shift in sardine and anchovy diet towards smaller planktonic prey indeed suggested bottom-up control as the main driver of these populations in the Gulf of Lions. The first aim of...
Tipo: Text
Palavras-chave: Poissons petits pélagiques; Expérience; Processus bottom-up; Modélisation; Traits d'histoire de vie; Small pelagic fish; Experiment; Bottom-Up processes; Modeling; Life history traits.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00692/80420/83556.pdf

Optimisation de procédés innovants pour l'obtention de phycocolloïdes
Provedor de dados: 5
Autores: Vauchel, Peggy.
Alginates are polysaccharides which are naturally present in the cell wall of brown algae and extracted because of their rheological properties. The alginate industry uses an extraction protocol, which central step, the carbonatation, is conducted in batch reactors. It is a high water, reagent and time demanding process. The main objective of this thesis is to optimize the alginate extraction process. A study of the existing process, focused on carbonatation step, enabled to highlight points which could be enhanced to optimize the extraction yield and the quality of extracted alginates. Stirring intensity and algae pieces size have been identified as parameters having an influence on the carbonatation reaction kinetics. A specific analysis on medullar and...
Tipo: Text
Palavras-chave: Alginate; Extraction; Laminaria digitata; Extrusion réactive; Optimisation; Modélisation; Distribution des temps de séjour; Cinétique; Rendement; Propriétés rhéologiques; Alginate; Extraction; Laminaria digitata; Reactive extrusion; Optimization; Modeling; Residence time distribution; Kinetics; Extraction yield; Rheological properties.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00002/11364/7937.pdf

Continuous fluorescence recording as a way to improve Pacific oyster (Crassostrea gigas) models of paralytic shellfish toxin accumulation
Provedor de dados: 5
Autores: Baron, Regis; Couedel, Marielle; Joret, Camille; Garen, Pierre; Truquet, Philippe; Masselin, Pierre; Bardouil, Michele; Lassus, Patrick.
A simple system was used to simulate the effect of alternating toxic (paralytic shellfish poisoning toxins) and non-toxic microalgal diets on oyster feeding behaviors and rates of toxin accumulation. These experimental conditions were meant to reflect, to some extent, the incoming and outgoing fluxes of toxic algae observed at the mouth of the Penze estuary (Northern Brittany, France). Physiological and toxicological parameters were estimated based oil fluorescence measurements recorded continuously at the outlet of each experimental tank, which contained a single oyster. Q(tox), this variable describes toxin uptake in oysters, it was used (instead of the toxin ingestion rate): i) in simple graphical analyses, ii) as well as in one- and two-compartment...
Tipo: Text
Palavras-chave: Skeletonema costatum; Alexandrium minutum; Fluorescence; Modeling; Kinetics; Toxin uptake; Shellfish toxin; PSP.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1400.pdf

The Gulf of Lions: An overview of recent studies within the French 'Margins' Programme
Provedor de dados: 5
Autores: Berne, Serge; Gorini, C.
Within the French 'Margins' Programme (Groupement de Recherches 'Marges', or 'GDR Marges'), The Gulf of Lions was selected as a key area where scientists specialized in complementary aspects of geosciences (structural geology, tectonics, stratigraphy, sedimentology, various aspects of modeling) work together in order to better understand the processes that control the formation and evolution of continental margins. A key objective was to link offshore data (that mainly consist of seismic data and few wells) and onshore studies (mainly based on well and field data). This special edition of Marine and Petroleum Geology on the Gulf of Lions presents some of the main results obtained during three years of research by the group 'GDR Marges-Golfe du Lion'.
Tipo: Text
Palavras-chave: Modeling; Geosciences; 'Margins' Programme; Gulf of Lions.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-728.pdf

Comparison of five integrative samplers in laboratory for the monitoring of indicator and dioxin-like polychlorinated biphenyls in water
Provedor de dados: 5
Autores: Jacquet, Romain; Miege, Cecile; Smedes, Foppe; Tixier, Celine; Tronczynski, Jacek; Togola, Anne; Berho, Catherine; Valor, Ignacio; Llorca, Julio; Barillon, Bruno; Marchand, Philippe; Coquery, Marina.
This study aimed at evaluating and comparing five integrative samplers for the monitoring of indicator and dioxin-like polychlorinated biphenyls (PCBs) in water: semi-permeable membrane device (SPMD), silicone rubber, low-density polyethylene (LDPE) strip, Chemcatcher and a continuous-flow integrative sampler (CFIS). These samplers were spiked with performance reference compounds (PRCs) and then simultaneously exposed under constant agitation and temperature in a 200 L stainless steel tank for periods ranging from one day to three months. A constant PCB concentration of about 1 ng·L−1 was achieved by immersing a large amount of silicone rubber sheets (“dosing sheets”) spiked with the target PCBs. The uptake of PCBs in the five samplers showed overall good...
Tipo: Text
Palavras-chave: Integrative samplers; Polychlorinated biphenyls; Water monitoring; Time weighted average concentration; Modeling.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00162/27317/25962.pdf

Méthodes pour la typologie des flottilles de pêche : bilan et ouvertures
Provedor de dados: 5
Autores: Rochet, Marie-joelle; Ferraris, Jocelyne; Biseau, Alain; Sabatier, R.
Introduction: Twenty reports or articles concerning fishing fleet typology work have been analysed. All of them come from IFREMER, except for two articles; one was published by Danish researchers and the other by Americans. Our purpose here is to review and assess this work on a methodological standpoint in order to identify if the objectives announced and methods used are adequately in line.
Tipo: Text
Palavras-chave: Capture; Statistics; Modeling; Typology; Fishing; Fleet.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/1994/rapport-1746.pdf

Modeling economic vulnerability: As applied to microbiological contamination on the Thau Lagoon shellfish farming industry
Provedor de dados: 5
Autores: Perez Agundez, José A.; Yimam, Eden; Raux, Pascal; Rey-valette, Helene; Girard, Sophie.
The economic impacts induced by the harmful effects of pollution or negative natural events are heterogeneous and depend on the event type and intensity, as well as the characteristic make-up of agents affected. This vulnerability analysis evaluates how each agent (or group of agents) is potentially affected by an external stress or event with respect to risk of exposure, sensitivity or intensity of subjection, and coping capacity of these agents in order to avoid or reduce its effects. Using a comparative formulation model, the aim of this paper is to quantifiably assess the vulnerability of shellfish farming linked to bacteriologic pollution. An analysis of the vulnerability concept and the construction of pertinent indicators are presented. The analysis...
Tipo: Text
Palavras-chave: Vulnerability; Modeling; Shellfish farming; Microbiologic contamination; Thau Lagoon.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00176/28775/30696.pdf

Les pêches maritimes : un terrain d’expérimentation de la géoprospective
Provedor de dados: 5
Autores: Tissière, Laurie; Mahévas, Stephanie; Michel, Charlotte; Trouillet, Brice.
A prospective approach can be used to establish management and environmental protection options to stimulate discussion and bring different scenarios for the future into perspective. This future-oriented process incorporates spatial dimensions with the development of a geoprospective approach. Indeed, a geoprospective approach highlights geographical dynamics and integrates spatial perspectives into the debate. A participatory framework for analyzing the marine fisheries sector has two main advantages. The first is academic, in that it helps to establish a methodological and epistemological corpus based on geoprospective. The method proposal allows, on the one hand, to discuss the purpose of the models and, on the other, to explore the role of researchers...
Tipo: Text
Palavras-chave: Géoprospective; Modélisation; Participation; Méthodes mixtes; Démocratie et gouvernance environnementales; Pêches maritimes; Geoprospective; Modeling; Participation; Mixed methods; Environmental democracy and governance; Marine fisheries.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00664/77597/79611.pdf

Mapping the Intertidal Microphytobenthos Gross Primary Production Part I: Coupling Multispectral Remote Sensing and Physical Modeling
Provedor de dados: 5
Autores: Méléder, Vona; Savelli, Raphael; Barnett, Alexandre; Polsenaere, Pierre; Gernez, Pierre; Cugier, Philippe; Lerouxel, Astrid; Le Bris, Anthony; Dupuy, Christine; Le Fouest, Vincent; Lavaud, Johann.
The gross primary production (GPP) of intertidal mudflat microphytobenthos supports important ecosystem services such as shoreline stabilization and food production, and it contributes to blue carbon. However, monitoring microphytobenthos GPP over a long-term and large spatial scale is rendered difficult by its high temporal and spatial variability. To overcome this issue, we developed an algorithm to map microphytobenthos GPP in which the following are coupled: (i) NDVI maps derived from high spatial resolution satellite images (SPOT6 or Pléiades), estimating the horizontal distribution of the microphytobenthos biomass; (ii) emersion time, photosynthetically active radiation (PAR), and mud surface temperature simulated from the physical model MARS-3D;...
Tipo: Text
Palavras-chave: Microphytobenthos; Intertidal mudflat; Gross primary production; Remote sensing; NDVI; Modeling.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75531/76429.pdf

Agulhas Leakage Predominantly Responds to the Southern Hemisphere Westerlies
Provedor de dados: 5
Autores: Durgadoo, Jonathan V.; Loveday, Benjamin R.; Reason, Chris J. C.; Penven, Pierrick; Biastoch, Arne.
The Agulhas Current plays a crucial role in the thermohaline circulation through its leakage into the South Atlantic Ocean. Under both past and present climates, the trade winds and westerlies could have the ability to modulate the amount of Indian-Atlantic inflow. Compelling arguments have been put forward suggesting that trade winds alone have little impact on the magnitude of Agulhas leakage. Here, employing three ocean models for robust analysisa global coarse-resolution, a regional eddy-permitting, and a nested high-resolution eddy-resolving configurationand systematically altering the position and intensity of the westerly wind belt in a series of sensitivity experiments, it is shown that the westerlies, in particular their intensity, control the...
Tipo: Text
Palavras-chave: Boundary currents; Meridional overturning circulation; Wind stress; Mesoscale models; Numerical analysis; Modeling.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00161/27247/25452.pdf

Les pêcheries mixtes de langoustine et de merlu du golfe de Gascogne. Description, préparation à une modélisation et à une simulation des procédures de gestion
Provedor de dados: 5
Autores: Charuau, Anatole; Ifremer.
1 - Study's goals review The management of Norway Lobster and Hake fisheries can be considered as the most important issue in the Gascogne gulf. Calculation methods used to evaluate prediction variations under various efforts and mesh constraints all pinpoint to the crucial role narrow mesh fishing plays in Hakes' Northern stock status. The involvement of Gascogne gulf Norway Lobster fisheries regarding Hakes over exploitation seems over dimensioned when comparing the size of both of these stocks. Hake stocks spread from Northern Great Britain to Northern Spain, while Norway Lobster stocks are located in the Gascogne gulf's mud flats. The biological solution is well known and consists in globally  increasing mesh nets to 80mm which would bring up Hakes...
Tipo: Text
Palavras-chave: Procedures of management; Modeling; Bay of Biscay; Mixed fishery; Lobster; Hake.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/rapport-1763.pdf

Reef Carbonate Productivity During Quaternary Sea Level Oscillations
Provedor de dados: 5
Autores: Husson, L.; Pastier, A. -m.; Pedoja, K.; Elliot, M.; Paillard, D.; Authemayou, C.; Sarr, A. -c.; Schmitt, A.; Cahyarini, S. Y.
Global variations in reef productivity during the Quaternary depend on external parameters that may alter the global chemical balance in the oceans and atmosphere. We designed a numerical model that simulates reef growth, erosion, and sedimentation on coastlines undergoing sea level oscillations, and uplift or subsidence. We further develop a probabilistic evaluation that accounts for variable vertical ground motion, erosion, and foundation morphologies. Absolute sea level change appears primordial, as productivity must have increased by an order of magnitude since the onset of the glacial cycles, approximate to 2.6 Ma. But most important is relative sea level change, i.e., eustasy modulated by uplift or subsidence, that rejuvenates the accommodation space...
Tipo: Text
Palavras-chave: Coral reefs; Sea level; Carbonate; Modeling; Paleoclimate.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00638/74993/75789.pdf

Microbial impact of small tributaries on water and shellfish quality in shallow coastal areas
Provedor de dados: 5
Autores: Riou, Philippe; Le Saux, Jean-claude; Dumas, Franck; Caprais, Marie-paule; Le Guyader, Soizick; Pommepuy, Monique.
This study aimed to investigate the impact of small tributaries on seawater and shellfish quality in coastal area subjected to brief episodes leading to fecal contamination. Escherichia coli and F-RNA-specific bacteriophages were selected as fecal indicators and astroviruses were chosen as being representative of pathogens in the human population during winter viral epidemics. A two-dimensional hydrodynamic model was built to simulate the current and dispersion in the model domain, which includes areas uncovered at low tide. The model also includes decay rates to simulate microorganism behavior and assess the influence of fecal input on shellfish quality. The originality lies in the fact that specific features of the study area were considered. Modeling...
Tipo: Text
Palavras-chave: Shellfish; Astrovirus; F RNA specific; E. coli; Seawater fecal contamination; Modeling.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2675.pdf

Ecologie larvaire de l'huître perlière (Pinctada margaritifera, L.), croissance et dispersion dans un lagon d'atoll polynésien
Provedor de dados: 5
Autores: Thomas, Yoann.
Understanding key factors determining the bentho-pelagic species larval growth and dispersal remains one of the challenges of marine ecology, notably to understand the adult population structure and dynamics. In the present study, we explore this determinism on the development and dispersal of the black-lip pearl oyster (Pinctada margaritifera var. cumingii, Linné 1758) larvae in a French Polynesian atoll lagoon (Ahe, Tuamotu archipelago). Rearing of the pearl oyster for the production of black pearls takes on a major social and economic place in French Polynesia. However, the supply of pearl oyster seed to the farms depends entirely on the natural collection of wild spat of the only one specie P. margaritifera, and spatial and temporal variability of spat...
Tipo: Text
Palavras-chave: Ecologie larvaire; Hétérogénéité environnementale; Modélisation; Croissance; Dispersion; Huître perlière à lèvres noires; Pinctada margaritifera; Lagon d’atoll; Polynésie française; Larval ecology; Environmental heterogeneity; Modeling; Growth; Dispersal; Black-lip pearl oyster; Pinctada margaritifera; Atoll lagoon; French Polynesia.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00003/11449/7999.pdf

Short-term upwelling events at the western African coast related to synoptic atmospheric structures as derived from satellite observations
Provedor de dados: 5
Autores: Desbiolles, Fabien; Blanke, Bruno; Bentamy, Abderrahim.
Satellite scatterometers provide continuously valuable surface wind speed and direction estimates over the global ocean on a regular grid both in space and time. The Level 3 data derived from the Advanced Scatterometer (ASCAT), available at 1/4° spatial resolution (hereafter AS25), and Quick Scatterometer (QuikSCAT), available on 1/2° and 1/4° horizontal grids (QS50 and QS25, respectively), are studied at regional scales in both the Benguela and Canary upwelling systems. They are compared to the European Center for Medium-Range Weather Forecast surface wind analysis, with insight into their intrinsic and actual spatial resolutions. In the coastal band, the finest spatial patterns are found in the QS25 winds and are O(75 km). This demonstrates the...
Tipo: Text
Palavras-chave: Satellite scatterometer wind fields; Actual wind resolution at regional scales; Short-lived SST anomalies; Eastern-boundary upwelling systems; Modeling.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00172/28333/26619.pdf

An experimental/numerical study of the catch weight influence on trawl behavior
Provedor de dados: 5
Autores: Priour, Daniel; De La Prada, Amelia.
Measurements at sea during fishing trials on bottom trawl have revealed that the geometry of the trawl is affected by the catch. A series of 37 hauls of around 3 h were carried out during the French EFFICHALUT project. The aim of this project was to carry out improvements on the fishing gear in order to reduce energy consumption. For this project, numerous sensors were used: for bridle tension, door spread, vertical opening, and door attitude. The measurements show quite clearly that the door spread decreases and the bridle tension increases during most of the hauls. The door spread decreased by 1.35 m/h, with a standard deviation of 1.98 m/h while the top bridle tension increased by 47 kg/h, with a standard deviation of 59 kg/h. The mean catch per haul...
Tipo: Text
Palavras-chave: Trawl; Data; Modeling; Door spread; Bridle tension; Catch weight.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00239/34990/33525.pdf

The role of the Agulhas in the Benguela Current System: A numerical modelling approach
Provedor de dados: 5
Autores: Veitch, Jennifer A.; Penve, Pierrick.
A modelling approach is used to investigate the influence of the Agulhas on the southern Benguela system. Two climatological ROMS simulations are run that are identical except that in one of them the effect of the Agulhas is removed. Comparing their output allows for a clear indication of the role of the Agulhas on both the large-scale and shelf dynamics. About 15 Sv of the mean transport of the Benguela Current is shown to be contributed by Agulhas influx, with the most intense flow being associated with extreme turbulence and its meandering nature is a reflection of the passage of Agulhas Rings. The injection of warm water is particularly evident beyond the shelf-edge, producing a perennially intense cross-shelf density front that is enhanced during...
Tipo: Text
Palavras-chave: Modeling; Benguela Current system; Agulhas leakage.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00383/49393/49826.pdf

A numerical modeling study of the Southern Senegal upwelling shelf: Circulation and upwelling source waters
Provedor de dados: 5
Autores: Ndoye, S; Capet, Xavier; Estrade, Philippe; Machu, Eric; Kounta, L; Sow, B; Diakhate, M; Gayet, At.
The regional ocean circulation along the Southern Senegal shelf is studied using a numerical model for varying forcing fields during the upwelling season (November-May). The main objective is to study the shelf circulation of the marine environment in the Southern Senegal Upwelling Shelf (SSUS), the Lagrangian pathways by which waters are transported to the surface in the upwelling tongue and the fate of these waters. Model results are compared with hydrographic measurements during UPSEN2-ECOAO survey and satellite images datasets. The upwelling source waters and also the warm nearshore waters are analyzed, from a Lagrangian point of view, by computing the paths of particles that are passively advected by the regional ocean model velocity field (ROMS). It...
Tipo: Text
Palavras-chave: Upwelling; Ocean circulation; Modeling; Coastal dynamics; Shelf; ROMS.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00472/58346/60900.pdf

Modélisation des contaminants en milieu aquatique: Module MET&amp;OR
Provedor de dados: 5
Autores: Thouvenin, Benedicte.
The MET&amp;OR module is a model, written in FORTRAN 90, which calculates the biogeochemical reactions between variables such as trace metal, radioactive tracers, organic or bacterial contaminants (biodegradation, decay, adsorption / desorption, photolysis, hydrolysis, volatilization, partition at equilibrium ..). It groups together classical reactions, described in the literature, to evaluate the source and sink terms which are integrated into the transport equations solved by a hydrodynamic model. It is intended more particularly for marine and coastal waters. This technical documentation aims to present the MET&amp;OR module and the way in which it was coupled to the hydrodynamic model, in particular to MARS-3D.
Tipo: Text
Palavras-chave: Modelisation; Biogéochimie; Contaminants métalliques; Organic contmainants; Contaminants bactériens; Modeling; Biogeochemical; Trace metals; Contaminants organiques; Bacterial contaminant.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00688/79972/83002.pdf

Suspended Sediment Dynamics in the Macrotidal Seine Estuary (France) - Part 1: Numerical Modeling of Turbidity Maximum Dynamics
Provedor de dados: 5
Autores: Grasso, Florent; Verney, Romaric; Le Hir, Pierre; Thouvenin, Benedicte; Schulz, Elisabeth; Kervella, Youenn; Fard, I. Khojasteh Pour; Lemoine, J. -p.; Dumas, Franck; Garnier, Valerie.
Tidal pumping, baroclinic circulation and vertical mixing are known to be the main mechanisms responsible for the estuarine turbidity maximum (ETM) formation. However, the influence of hydro-meteorological conditions on ETM dynamics is still not properly grasped and requires further investigation to be quantified. Based on a realistic 3-dimensional numerical model of the macrotidal Seine Estuary (France) that accounts for mud and sand transport processes, the objective of this study is to quantify the influence of the main forcing (river flow, tides, waves) on the ETM location and mass changes. As expected, the ETM location is strongly modulated by semidiurnal tidal cycles and fortnightly timescales with a high sensitivity to river flow variations. The ETM...
Tipo: Text
Palavras-chave: Estuary; Mud; Sand; Hydrodynamics; Turbidity maximum; Waves; Measurement; Modeling.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00416/52770/53638.pdf

The Earth's hum variations from a global model and seismic recordings around the Indian Ocean
Provedor de dados: 5
Autores: Deen, M.; Stutzmann, Eleonore; Ardhuin, Fabrice.
The Earth's hum is the continuous oscillations of the Earth at frequencies between 2 and 20 mHz in the absence of earthquakes. The hum strongest signal consists mainly of surface waves. These seismic waves can be generated by infragravity waves propagating over a sloping ocean bottom close to the coast. So far, this theory has only been tested quantitatively using European seismic stations. We use seismic data recorded all around the Indian Ocean together with an ocean wave model that provides time‐frequency varying hum sources. We show that seasonal variations of the hum sources are smaller in the southern hemisphere (SH) than the northern hemisphere (NH). Using these sources, we model Rayleigh wave RMS amplitudes in the period band 3.5‐20 mHz, and the...
Tipo: Text
Palavras-chave: Seismic hum; Infragravity waves; Indian Ocean; Seismic noise; Hum sources; Modeling.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00455/56678/58435.pdf

Nutrient export to an Eastern Atlantic coastal zone: first modeling and nitrogen mass balance
Provedor de dados: 5
Autores: Canton, Mathieu; Anschutz, Pierre; Coynel, Alexandra; Polsenaere, Pierre; Auby, Isabelle; Poirier, Dominique.
We have studied 15 catchments supplying freshwater to a French Atlantic coastal lagoon, where increase in nitrogen loads due to agriculture is supposed to have destabilized the ecosystem in the last decades. The catchment is a lowland composed of Pleistocene sands with an average slope of 0.25%. To study the nutrient export in relation to land-use surface waters were sampled bi-weekly between October 2006 and January 2009 and land-use was established by plane photographs and Geographic Information System (GIS). Cultivated pine forests represent more than 80% of the total surface and 7% of the catchment area has been deforested recently. Significant areas of some catchments are used for maize crop. Housing is confined to the coastal zone. Maize and forest...
Tipo: Text
Palavras-chave: Nitrogen; Phosphorus; River export; Land use; Coastal catchment; Arcachon Bay; Modeling; Mass balance.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00065/17615/15173.pdf

Numerical modeling of bottom trawling-induced sediment transport and accumulation in La Fonera submarine canyon, northwestern Mediterranean Sea
Provedor de dados: 5
Autores: Payo-payo, Marta; Silva Jacinto, Ricardo; Lastras, G.; Rabineau, Marina; Puig, P.; Martin, J.; Canals, M.; Sultan, Nabil.
Bottom trawling leads to recurrent sediment resuspension events over fishing grounds. Recent studies have shown how bottom trawling can drive seascape reshaping at large spatial scales and enhance sediment transport in submarine canyons, which subsequently impacts deep-sea ecosystems. Present knowledge on the transfer and accumulation of sediment flows triggered by bottom trawling is based on localized and infrequent measurements whilst a more complete picture of the process is needed. The present work focuses on the modeling of sediment transport and accumulation resulting from trawling activities in La Fonera submarine canyon, northwestern Mediterranean Sea, thus contributing to an improved assessment of trawling impacts. Based on mooring data within a...
Tipo: Text
Palavras-chave: Bottom trawling; Inverse model; Modeling; Sediment transport; Submarine canyon; Turbidity currents.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00374/48549/48862.pdf

Role of particle sorption properties in the behavior and speciation of trace metals in macrotidal estuaries: The cadmium example
Provedor de dados: 5
Autores: Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine; Chiffoleau, Jean-francois; Boutier, Bernard.
The role of particles in the fate and speciation of trace metals in macrotidal estuaries was studied using a surface complexation model (MOCO). Cadmium was selected as the target metal contaminant due to its reactivity in estuaries: cadmium behavior is mainly controlled by heterogeneous processes (sorption/desorption) related to salinity and suspended matter gradients.   Various scenarios of suspended matter distribution according to salinity were simulated. The impact of surface properties (specific surface area, density of surface sites, acido-basic properties, and complexation constant) was evaluated using data collected on particles from the Gironde, Loire, and Seine estuaries.   Our results show that particle surface properties, evaluated on the basis...
Tipo: Text
Palavras-chave: Turbidity maximum; Speciation; Sorption; Particles; Modeling; Macrotidal estuaries; Cadmium.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2005.pdf

Rôle des particules sur le comportement et la spéciation de métaux traces: exemple du cadmium
Provedor de dados: 5
Autores: Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine.
The role of particles in the fate and speciation of trace metals in macrotidal estuaries was studied using a surface complexation model (MOCO). Cadmium was selected as the target metal contaminant due to its reactivity in estuaries: cadmium behavior is mainly controlled by heterogeneous processes (sorption/desorption) related to salinity and suspended matter gradients.Various scenarios of suspended matter distribution according to salinity were simulated. The impact of surface properties (specific surface area, density of surface sites, acidity instrinsic properties and complexation constant) was evaluated using data collected on particles from the Gironde, Loire and Seine estuaries.
Tipo: Text
Palavras-chave: Particles; Speciation; Sorption/desorption; Cadmium; Modeling; Surface properties.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00480/59152/61781.pdf

Modélisation des contaminants chimiques dans une colonne d'eau. Modèle MOMO (MORGAN+MOCO).
Provedor de dados: 5
Autores: Thouvenin, Benedicte; Gonzalez, Jean-louis.
Within the framework of the "Contaminants cycle and modeling" project of the BE department ("Biogeochemistry and Ecotoxicology") in Ifremer, two chemical contaminant modeling software were developed between 1998 and 2011 (Gonzalez JL, 2017): the MORGAN model (Model behavior of ORGANic contaminants in an aquatic environment) and the MOCO model (Surface Complexation MOdel for metallic COntaminants). These two models had been brought together in a single "zero-dimensional" software (known as MOMO), which made it possible to simulate the various processes affecting the behavior of chemical contaminants in a homogeneous mass of water (biodegradation, adsorption/desorption, photolysis, hydrolysis, volatilization, surface complexation, cation exchange,...
Tipo: Text
Palavras-chave: Modelisation; Biogeochimie; Contaminants métalliques et organiques; Spéciation; Modeling; Biochemical; Trace metals - organic contaminants; Speciation.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00686/79771/82993.pdf

Modeling on gas hydrate formation conditions in the Qinghai-Tibet plateau permafrost
Provedor de dados: 5
Autores: Lu, Zhen Quan; Sultan, Nabil; Jin, Chun Shuang; Rao, Zhu; Luo, Xu Rong; Wu, Bi Hao; Zhu, You Hai.
Based on field investigated gas geochemistry and predecessors' data such as the permafrost ground temperature, thermal gradients within/below the frozen layer, the modeling on gas hydrate formation conditions is conducted in the Qinghai Tibet plateau permafrost. The modeled results show that the permafrost characteristics generally meet gas hydrate formation conditions in the study area. Gas composition, temperature-related permafrost parameters (e. g. permafrost thickness or its ground temperature and thermal gradients within / below the frozen layer) are the most important factors affecting gas hydrate occurrences, whose variance may cause the heterogeneity of gas hydrate occurrences in the study area. The most probable gas hydrate is the kind of hybrid...
Tipo: Text
Palavras-chave: Qinghai Tibet plateau; Modeling; Formation conditions; Gas hydrate; Permafrost.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6230.pdf

Potential effects of deep seawater discharge by an Ocean Thermal Energy Conversion plant on the marine microorganisms in oligotrophic waters
Provedor de dados: 5
Autores: Giraud, Mélanie; Garçon, Véronique; De La Broise, Denis; L'Helguen, Stéphane; Sudre, Joël; Boye, Marie.
Installation of an Ocean Thermal Energy Conversion pilot plant (OTEC) off the Caribbean coast of Martinique is expected to use approximately 100,000 m3 h−1 of deep seawater for its functioning. This study examined the potential effects of the cold nutrient-rich deep seawater discharge on the phytoplankton community living in the surface warm oligotrophic waters before the installation of the pilot plant. Numerical simulations of deep seawater upwelled by the OTEC, showed that a 3.0 °C temperature change, considered as a critical threshold for temperature impact, was never reached during an annual cycle on the top 150 m of the water column on two considered sections centered on the OTEC. The thermal effect should be limited, &lt;1 km2 on the area exhibited...
Tipo: Text
Palavras-chave: Marine microbial ecosystem; Biogeochemistry; Modeling; Artificial seawater discharge in situ experiments; Environmental standards.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00507/61867/65935.pdf

How Enhancing Atmospheric Monitoring and Modeling can be Effective for the Stockholm Convention on POPs
Provedor de dados: 5
Autores: Guardans, Ramon; Castro-jimenez, Javier.
The presence of toxic substances such as persistent organic pollutants (POPs) in the environment, and in organisms including humans, is a serious public health and environmental problem, even at low levels and poses a challenging scientific problem. The Stockholm Convention on POPs (SC) entered into force in 2004 and is a large international effort under the United Nations Environment Programme (UNEP) to facilitate cooperation in monitoring, modeling and the design of effective and fair ways to deal with POPs globally. This paper is a contribution to the ongoing effectiveness evaluation (EE) work aimed at the assessment and enhancement of the effectiveness of the actions undertaken under the SC. First we consider some aspects related to the monitoring of...
Tipo: Text
Palavras-chave: POPs monitoring; Modeling; Stockholm Convention effectiveness; Global Monitoring Plan.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00645/75724/76673.pdf

Etude de déploiement d'un réseau LoRa en mer
Provedor de dados: 5
Autores: Damour, Valentin.
This report is about the work realized during a part time training at Ifremer. The subject discussed in this paper will associate the maritime field and the computer science field. It proves that computer science is really a  multipurpose domain. In a context of global warming and human pressure (pollution and ressources over-exploitation), the marine ecosystem is jeopardized. In order to have a better understanding of the situation of this habitat and to stem these brutal changes, it is important to observe and gather information about it. It is exactly the goal of the project I took part in. This project mainly deals with observing sea turtles in their natural habitat. Thoses observations are realized thanks to LoRa equiped tags which are implanted on...
Tipo: Text
Palavras-chave: Réseau tolérant au délai; Océan Indien; Tortues marines; Modélisation; Delay-tolerant network; Indian Ocean; Sea turtles; Modeling.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00612/72364/71279.pdf

Distribuição diamétrica de espécies da Floresta Ombrófila Densa no Sul do Estado do Rio de Janeiro
Provedor de dados: 190
Autores: Cysneiros, Vinicius Costa; Amorim, Thiago de Azevedo; Mendonça Júnior, Joaquim de Oliveira; Gaui, Tatiana Dias; de Moraes, Juan Carlos Resende; Braz, Denise Monte; Machado, Sebastião do Amaral.
O objetivo do presente estudo foi avaliar o desempenho e selecionar funções densidade de probabilidade que descrevam a distribuição diamétrica da comunidade florestal e das três principais espécies da Floresta Ombrófila Densa no sul do estado do Rio de Janeiro. Foram testadas as funções Normal, Log Normal, Beta, Gama, Sb de Johnson e Weibull. Os ajustes foram realizados com auxílio da ferramenta Solver (MSExcel®), que utiliza o algoritmo linear de gradiente reduzido para otimização dos parâmetros das funções. Para a seleção do melhor modelo foram avaliados o valor D de Kolmogorov – Smirnov e o erro padrão da estimativa (Syx %). De maneira geral, as funções Sb de Johnson e Weibull apresentaram as melhores estatísticas de ajuste e maior precisão nas...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Recursos Florestais; Engenharia Florestal; Dendrometria Floresta Atlântica; Funções densidade de probabilidade; Modelagem Atlantic Forest; Density probability functions; Modeling.
Ano: 2017
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/1070

Estimate of Acacia mangium volume using techniques of artificial neural networks and support vector machines
Provedor de dados: 190
Autores: Cordeiro, Márcio Assis; Pereira, Nayara Natacha de Jesus; Binoti, Daniel Henrique Breda; Binoti, Mayra Luiza Marques da Silva; Leite, Hélio Garcia.
The present study aimed to show the results of Acacia mangium volumetric estimates obtained through the Schumacher and Hall model compared to the methods of artificial neural networks and support vector machines. To enable this comparative analysis, we used data from 31 trees of Acacia mangium aged 14–17, from a stand located in the northern region of the state of Amapá. Diameter and bark thickness of the trees were measured into relative heights along the stem into 14 sections (0.05%, 1%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 95%), with measurement. Total volume with bark was obtained by applying the Smalian formula. In general, the methods that differ from traditional methods showed statistically superior results.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Smalian; Modeling; Volumetric estimates Engenharia Florestal Manejo Florestal Recursos Florestais Smalian; Modelagem; Estimativa volumétrica.
Ano: 2015
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/596

Relation between higher heating value and elemental and mineral biomass plant components
Provedor de dados: 190
Autores: Protásio, Thiago de Paula; Bufalino, Lina; Tonoli, Gustavo Henrique Denzin; Couto, Allan Motta; Trugilho, Paulo Fernando; Guimarães Júnior, Mário.
The aims of this work were to evaluate the correlation, to adjust and select simple and multiple linear statistical models between elemental components (carbon, hydrogen and oxygen) and ash content with higher heating value for plant biomass; to use the principle components analysis for the creation of an energetic development index and to adjust a linear model between energetic development index and higher heating value. Eight types of biomass were used. Three linear and nine multiple statistical models were adjusted. The best models were selected based on the significance of coefficients, adjusted determination coefficient, estimative standard error, coefficient of variation, linearity of parameters, normality, presence of heterocedasticity and lack of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Regression; Correlation; Selection Modelagem; Regressão; Correlação; Seleção.
Ano: 2011
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/200

Introducing rice yield loss caused by weed competition into the SimulArroz model
Provedor de dados: 86
Autores: Richter,Gean Leonardo; Streck,Nereu Augusto; Zanon,Alencar Junior; Ulguim,André da Rosa; Kruse,Nelson Diehl; Santos,Gionei Alves de Assis dos; Cera,Jossana Ceolin; Ribas,Giovana Ghisleni; Duarte Junior,Ary José; Pilecco,Isabela Bulegon.
Abstract: The objective of this work was to model weedy rice (Oryza sativa) and barnyard grass (Echinochloa spp.) competition with flood-irrigated rice, introducing it as a submodule into the SimulArroz model. The competition of both weeds with irrigated rice was modeled using the rectangular hyperbola equation. The “i” and “a” coefficients of the rectangular hyperbola for each of these weeds were obtained from the literature and from field experiments carried out in the state of Rio Grande do Sul, Brazil. In SimulArroz, yield loss was applied to penalize yield in all three technological levels (high, medium, and low) of physiological maturity. For weedy rice, the coefficient values of imean for the high, medium, and low technological levels were 1.04,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oryza sativa; Barnyard grass; Modeling; Weedy rice; Yield loss.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000102508

Simulating maize phenology as a function of air temperature with a linear and a nonlinear model
Provedor de dados: 86
Autores: Streck,Nereu Augusto; Lago,Isabel; Gabriel,Luana Fernandes; Samboranha,Flavia Kaufmann.
The objective of this study was to adapt a nonlinear model (Wang and Engel - WE) for simulating the phenology of maize (Zea mays L.), and to evaluate this model and a linear one (thermal time), in order to predict developmental stages of a field-grown maize variety. A field experiment, during 2005/2006 and 2006/2007 was conducted in Santa Maria, RS, Brazil, in two growing seasons, with seven sowing dates each. Dates of emergence, silking, and physiological maturity of the maize variety BRS Missões were recorded in six replications in each sowing date. Data collected in 2005/2006 growing season were used to estimate the coefficients of the two models, and data collected in the 2006/2007 growing season were used as independent data set for model evaluations....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zea mays; Degree days; Development; Modeling; Thermal time.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2008000400002

Growth curves of meat-producing mammals by von Bertalanffy’s model
Provedor de dados: 86
Autores: Fernandes,Felipe Augusto; Fernandes,Tales Jesus; Pereira,Adriele Aparecida; Meirelles,Sarah Laguna Conceição; Costa,Adriano Carvalho.
Abstract: The objective of this work was to evaluate how the parameterization and the application of different allometric values affect the obtention of the most adequate fit of von Bertalanffy’s model, in the description of the growth curve of meat-producing mammals (bovine, pigs, rabbits, and sheep). Among the nonlinear models, von Bertalanffy’s has been very often applied in several areas, with different parameterizations. This model has been commonly used with an allometric value of m = 2/3; however, for mammals, it is believed that this value can be m = 3/4. The analyzed data referring to the mass of meat-producing mammals according to their age were obtained from research institutions and from the literature. The results showed that von Bertalanffy’s...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Allometry; Modeling; Nonlinear model; Parameterization; Regression.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000104307

Software for interpolation of vegetative growth of yerba mate plants in 3D
Provedor de dados: 86
Autores: Silva,Murilo Hilário Mazza da; Rakocevic,Miroslava.
The objective of this work was to build mock-ups of complete yerba mate plants in several stages of development, using the InterpolMate software, and to compute photosynthesis on the interpolated structure. The mock-ups of yerba-mate were first built in the VPlants software for three growth stages. Male and female plants grown in two contrasting environments (monoculture and forest understory) were considered. To model the dynamic 3D architecture of yerba-mate plants during the biennial growth interval between two subsequent prunings, data sets of branch development collected in 38 dates were used. The estimated values obtained from the mock-ups, including leaf photosynthesis and sexual dimorphism, are very close to those observed in the field. However,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ilex paraguariensis; AMAPmod; Modeling; Plant architecture; Plant growth; 3D reconstruction.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2010000300003

Long-term changes in rice development in Southern Brazil, during the last ten decades
Provedor de dados: 86
Autores: Streck,Nereu Augusto; Uhlmann,Lilian Osmari; Gabriel,Luana Fernandes.
The objective of this work was to test long-term trends in the duration of rice development phases in Santa Maria, RS, Brazil. The duration from emergence to V3 (EM-V3), emergence to panicle differentiation (EM-R1), emergence to anthesis (EM-R4), and emergence to all grains with brown hull (EM-R9) was calculated using leaf appearance and developmental models for four rice cultivars (IRGA 421, IRGA 417, EPAGRI 109, and EEA 406), for the period from 1912 to 2011, considering three emergence dates (early, mid, and late). The trend of the time series was tested with the non-parametric Mann-Kendall test, and the magnitude of the trend was estimated with simple linear regression. Rice development has changed over the last ten decades in this location, leading to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oryza sativa; Development rate; Global warming; Growing season; Maturity group; Modeling; Phenology.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000600001

Morphometric characteristics of the Mangalarga Marchador horse breed determined by nonlinear models
Provedor de dados: 86
Autores: Souza,Felipe Amorim Caetano de; Fernandes,Tales Jesus; Cunha,Fabiana Oliveira; Ribeiro,Rafaela Aparecida; Muniz,Fabiana Rezende; Meirelles,Sarah Laguna Conceição; Muniz,Joel Augusto; Moura,Raquel Silva.
Abstract: The objective of this work was to evaluate the development of the morphometric characteristics of Mangalarga Marchador horses through nonlinear models. The transversal method was used to collect data on height at the withers (HW), body length (BL), and thoracic (TP) and cannon (CP) perimeters from 200 horses (75 males and 125 non-pregnant females), aged between 6 and 153 months. The parameters of the Brody, Gompertz, logistic, and von Bertalanffy nonlinear models were estimated using the R software. Models were compared and selected using the coefficient of determination, the residual standard deviation, and the corrected Akaike information criterion. For adult females, HW, BL, TP, and CP ranged between 146.45-148.34, 148.59-151.64,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Equus caballus; Brody; Gompertz; Logistic; Modeling; Von Bertalanffy.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000104308

Growth and yield of teak stands at different spacing
Provedor de dados: 86
Autores: Medeiros,Reginaldo Antonio; Paiva,Haroldo Nogueira de; D’Ávila,Flávio Siqueira; Leite,Helio Garcia.
Abstract: The objective of this work was to evaluate the growth and yield of teak (Tectona grandis) stands at different spacing and in different soil classes. Twelve spacing were evaluated in an Inceptisol and Oxisol, in plots with an area of 1,505 or 1,548 m2, arranged in a completely randomized design with nine replicates. The teak trees were measured at 26, 42, 50, and 78 months of age. Total tree height was less affected by spacing. Mean square diameter was greater in wider spacing, whereas basal area and total volume with bark were greater in closer spacing. An increase in volume with bark per tree was observed with the increase of useful area per plant. For teak trees, growth stagnation happens earlier, the growth rate is higher in closer spacing,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tectona grandis; Initial spacing; Modeling.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018001001109

Dry matter production of Tanzania grass as a function of agrometeorological variables
Provedor de dados: 86
Autores: Pezzopane,José Ricardo Macedo; Santos,Patricia Menezes; Mendonça,Fernando Campos; Araujo,Leandro Coelho de; Cruz,Pedro Gomes da.
The objective of this work was to develop and validate linear regression models to estimate the production of dry matter by Tanzania grass (Megathyrsus maximus, cultivar Tanzania) as a function of agrometeorological variables. For this purpose, data on the growth of this forage grass from 2000 to 2005, under dry‑field conditions in São Carlos, SP, Brazil, were correlated to the following climatic parameters: minimum and mean temperatures, degree‑days, and potential and actual evapotranspiration. Simple linear regressions were performed between agrometeorological variables (independent) and the dry matter accumulation rate (dependent). The estimates were validated with independent data obtained in São Carlos and Piracicaba, SP, Brazil. The best statistical...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Panicum maximum; Climatic growth index; Degree‑days; Evapotranspiration; Modeling.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000400001

Predicting chick body mass by artificial intelligence-based models
Provedor de dados: 86
Autores: Ferraz,Patricia Ferreira Ponciano; Yanagi Junior,Tadayuki; Hernández Julio,Yamid Fabián; Castro,Jaqueline de Oliveira; Gates,Richard Stephen; Reis,Gregory Murad; Campos,Alessandro Torres.
The objective of this work was to develop, validate, and compare 190 artificial intelligence-based models for predicting the body mass of chicks from 2 to 21 days of age subjected to different duration and intensities of thermal challenge. The experiment was conducted inside four climate-controlled wind tunnels using 210 chicks. A database containing 840 datasets (from 2 to 21-day-old chicks) - with the variables dry-bulb air temperature, duration of thermal stress (days), chick age (days), and the daily body mass of chicks - was used for network training, validation, and tests of models based on artificial neural networks (ANNs) and neuro-fuzzy networks (NFNs). The ANNs were most accurate in predicting the body mass of chicks from 2 to 21 days of age...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Animal welfare; Artificial neural network; Broiler; Modeling; Neuro-fuzzy network; Thermal comfort.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000700559

Agricultural zoning of climate risk for Physalis peruviana cultivation in Southeastern Brazil
Provedor de dados: 86
Autores: Aparecido,Lucas Eduardo de Oliveira; Batista,Rafael Madureira; Moraes,José Reinaldo da Silva Cabral de; Costa,Cícero Teixeira Silva; Moraes-Oliveira,Adriana Ferreira de.
Abstract: The objective of this work was to elaborate the agricultural zoning of climatic risk (ZARC) for Physalis peruviana, through the thermal and water requirements of the crop in Southeastern Brazil. Air temperature (TAIR) and precipitation (PYEAR) data from 1,530 meteorological stations covering the entire region were used. Regions were considered climatically favorable to Physalis peruviana when TAIR was between 13 and 18ºC and PYEAR between 1,000 and 2,000 mm per year. Regions where TAIR was above 30ºC or less than 13ºC were considered inapt. Maps were created with this information and used to identify climatic characteristics and to establish the agricultural aptitude classes, termed apt, inapt, and marginal for the cultivation of Physalis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Climate risk; Agrometeorology; Modeling; Big data.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000100900

CO2-response function of radiation use efficiency in rice for climate change scenarios
Provedor de dados: 86
Autores: Streck,Nereu Augusto; Rosa,Hamilton Telles; Walter,Lidiane Cristine; Silva,Michel Rocha da; Uhlmann,Lilian Osmari.
The objective of this work was to evaluate a generalized response function to the atmospheric CO2 concentration [f(CO2)] by the radiation use efficiency (RUE) in rice. Experimental data on RUE at different CO2 concentrations were collected from rice trials performed in several locations around the world. RUE data were then normalized, so that all RUE at current CO2 concentration were equal to 1. The response function was obtained by fitting normalized RUE versus CO2 concentration to a Morgan-Mercer-Flodin (MMF) function, and by using Marquardt's method to estimate the model coefficients. Goodness of fit was measured by the standard deviation of the estimated coefficients, the coefficient of determination (R²), and the root mean square error (RMSE). The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oryza sativa; Global warming; Modeling; Photosynthesis.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000700001

Growth and development of Conyza bonariensis based on days or thermal units
Provedor de dados: 86
Autores: Soares,Daniel Jorge; Oliveira,Wladecir Salles de; Uzuele,Elvio Lorençato; Carvalho,Saul Jorge Pinto de; Ovejero,Ramiro Fernando Lopez; Christoffoleti,Pedro Jacob.
Abstract: The objective of this work was to evaluate the growth and development of a glyphosate-resistant population of Conyza bonariensis in different sowing dates (autumn, winter, and spring) and in two agricultural environments, based on days or thermal units. Five experiments were performed in two agricultural environments in Brazil: two in the municipality of Não-Me-Toque, in the state of Rio Grande do Sul - with sowings in July and September 2011; and three in the municipality of Santa Cruz das Palmeiras, in the state of São Paulo ‒ with sowings in April, July, and September 2011. In each trial, ten evaluations of the phenological development and total dry mass of C.bonariensis were performed, fitting these variables to a unit of time in days or...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hairy fleabane; Dry mass; Growing degree days; Modeling; Phenology; Weed biology.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017000100045

Reference sample size for multiple regression in corn
Provedor de dados: 86
Autores: Cargnelutti Filho,Alberto; Toebe,Marcos.
Abstract: The objective of this work was to determine the number of plants required to model corn grain yield (Y) as a function of ear length (X1) and ear diameter (X2), using the multiple regression model Y = β0 + β1X1 + β2X2. The Y, X1, and X2 traits were measured in 361, 373, and 416 plants, respectively, of single-, three-way, and double-cross hybrids in the 2008/2009 crop year; and in 1,777, 1,693, and 1,720 plants, respectively, of single-, three-way, and double-cross hybrids in the 2009/2010 crop year, totaling 6,340 plants. Descriptive statistics were calculated, and frequency histograms and scatterplots were created. The sample size (number of plants) for the estimate of the β0, β1, and β2 parameters, of the residual standard error, the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zea mays; Descriptive statistics; Hybrids; Modeling; Resampling.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2020000102100

Modeling light interception and distribution in mixed canopy of common cocklebur (Xanthium stramarium) in competition with corn
Provedor de dados: 87
Autores: Vazin,F.; Hassanzadeh,M.; Madani,A.; Nassiri-Mahallati,M.; Nasri,M.
The aim of this study was to model light interception and distribution in the mixed canopy of Common cocklebur (Xanthium stramarium) with corn. An experiment was conducted in factorial arrangement on the basis of randomized complete blocks design with three replications in Gonabad in 2006-2007 and 2007-2008 seasons. The factors used in this experiment include corn density of 7.5, 8.5 and 9.5 plants per meter of row and density of Common cocklebur of zero, 2, 4, 6 and 8 plants per meter of row. INTERCOM model was used through replacing parabolic function with triangular function of leaf area density. Vertical distribution of the species' leaf area showed that corn has concentrated the most leaf area in layer of 80 to 100 cm while Common cocklebur has...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Competition; Common cocklebur; Corn; Light.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582010000300001

Growth and Development of Purple Nutsedge Based on Days or Thermal Units
Provedor de dados: 87
Autores: Lima,R.S.O.; Machado,E.C.R.; Silva,A.P.P.; Marques,B.S.; Gonçalves,M.F.; Carvalho,S.J.P.
This work was carried out with the objective of elaborating mathematical models to predict growth and development of purple nutsedge (Cyperus rotundus) based on days or accumulated thermal units (growing degree days). Thus, two independent trials were developed, the first with a decreasing photoperiod (March to July) and the second with an increasing photoperiod (August to November). In each trial, ten assessments of plant growth and development were performed, quantifying total dry matter and the species phenology. After that, phenology was fit to first degree equations, considering individual trials or their grouping. In the same way, the total dry matter was fit to logistic-type models. In all regressions four temporal scales possibilities were assessed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cyperus rotundus; Growing degree days; Phenology; Base temperature; Modeling.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582015000200165

Initial growth and development of southern sandbur based on thermal units
Provedor de dados: 87
Autores: Machado,E.C.R.; Lima,R.S.O.; Silva,A.P.P.; Marques,B.S.; Gonçalves,M.F.; Carvalho,S.J.P.
Availability of basic information on weed biology is an essential tool for designing integrated management programs for agricultural systems. Thus, this study was carried out in order to calculate the base temperature (Tb) of southern sandbur (Cenchrus echinatus), as well as fit the initial growth and development of the species to accumulated thermal units (growing degree days - GDD). For that purpose, experimental populations were sown six times in summer/autumn conditions (decreasing photoperiod) and six times in winter/spring condition (increasing photoperiod). Southern sandbur phenological evaluations were carried out, on alternate days, and total dry matter was measured when plants reached the flowering stage. All the growth and development fits were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cenchrus echinatus; Weed; Biology; Growing degree days; Modeling.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000200011

Modeling the Regional Economic Impacts of the 2007/08 Drought: Results and Lessons
Provedor de dados: 31
Autores: Butcher,   G.V; Ford,   Stuart.
The 2007-08 drought affected a large area of New Zealand. This paper describes the analytical framework used to estimate the associated regional and national economic impacts. Results suggest that calculating drought economic impacts by applying standard farming industry multipliers to changes in farm gate output can greatly overstate both regional and national economic impacts. Calculating impacts using differences between forecast and actual farm production and expenditure by farm type is both feasible and produces far more reliable impact estimates.
Tipo: Conference Paper or Presentation
Palavras-chave: Economic Impact; Drought; Modeling; Agricultural and Food Policy; Crop Production/Industries; Environmental Economics and Policy; Farm Management; Land Economics/Use.
Ano: 2009
URL: http://purl.umn.edu/97167

The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions
Provedor de dados: 31
Autores: Gassman,   Philip W.; Reyes,   Manuel R.; Green,   Colleen H.; Arnold,   Jeffrey G.
The Soil and Water Assessment Tool (SWAT) model is a continuation of nearly 30 years of modeling efforts conducted by the U.S. Department of Agriculture (USDA), Agricultural Research Service. SWAT has gained international acceptance as a robust interdisciplinary watershed modeling tool, as evidenced by international SWAT conferences, hundreds of SWAT-related papers presented at numerous scientific meetings, and dozens of articles published in peer-reviewed journals. The model has also been adopted as part of the U.S. Environmental Protection Agency's BASINS (Better Assessment Science Integrating Point &amp; Nonpoint Sources) software package and is being used by many U.S. federal and state agencies, including the USDA within the Conservation Effects...
Tipo: Working or Discussion Paper
Palavras-chave: Developmental history; Flow analysis; Modeling; SWAT; Water quality; Resource /Energy Economics and Policy.
Ano: 2007
URL: http://purl.umn.edu/10285

Modeling the Crop Insurance Industry Portfolio Gains and Losses (PowerPoint)
Provedor de dados: 31
Autores: Vergara,   Oscar; Zuba,   Gerhard; Seaquist,   Jack.
Powerpoint slide show presenting information about AIR (the first catastrophic modeling company), weather-based yield models, agricultural portfolio loss model, and applications to crop insurance/reinsurance.
Tipo: Conference Paper or Presentation
Palavras-chave: Risk; Crop insurance; Reinsurance; Modeling; Agricultural loss; Loss model; Yield model; Risk and Uncertainty.
Ano: 2008
URL: http://purl.umn.edu/43766

REGIONAL ESTIMATION OF SOIL CARBON AND OTHER ENVIRONMENTAL INDICATORS USING EPIC AND I_EPIC
Provedor de dados: 31
Autores: Gassman,   Philip W.; Campbell,   Todd D.; Izaurralde,   R. Cesar; Thomson,   Allison M.; Atwood,   Jay D.
Computer models are important tools for assessing regional carbon sequestration and other environmental impacts of agricultural management practices. The Environmental Policy Integrated Climate (EPIC) model is a very flexible model that has been used to make a wide range of field- and regional-scale environmental assessments. Large regional-scale applications of EPIC and similar models can require thousands of runs, resulting in a huge data management task. To address this problem, the Center for Agricultural and Rural Development (CARD) has developed an interactive EPIC (i_EPIC) software package that provides an automated approach to executing large sets of EPIC simulations. Overviews of both the latest EPIC version and the i_EPIC software package are...
Tipo: Working or Discussion Paper
Palavras-chave: Environmental indicators; Modeling; Regional analyses; Software interface; Soil carbon; Environmental Economics and Policy.
Ano: 2003
URL: http://purl.umn.edu/18647

Modellierung von Betriebsentwicklung und Nachhaltigkeitszielen
Provedor de dados: 31
Autores: Zeddies,   Jurgen.
In his numerous textbooks WILHELM BRANDES has laid the foundation for theoretically appropriate modeling of farm firms, which has recently been expanded to modeling sustainability goals. The published research results belong to the fields of economic, ecological, and social sustainability. Standard method for the analysis of economic sustainability is the gross margin calculation, for the given purpose extended by associated opportunity costs and/or by appropriately adding further associable branch specific costs. At an on-farm-basis the system has been developed to a management information system under sustainability goals which has been further developed to the new forms of precision agriculture by incorporating yield and soil nutrient mapping,...
Tipo: Journal Article
Palavras-chave: Farm planning; Modeling; Sustainability goals; International competitiveness; Transform processes; Agro-environmental policy; Environmental Economics and Policy; Farm Management.
Ano: 2001
URL: http://purl.umn.edu/99003

Analyzing supply response of fruit tree products in Tunisia: The case of peaches
Provedor de dados: 31
Autores: Laajimi,   Abderraouf; Guesmi,   Anis; Mahfoudhi,   A.; Dhehibi,   Boubaker.
In Tunisia, peaches have a significant place in the fruit tree sector. Planted areas have  been expanding ever since the eighties as a result of irrigation water extension and the  use of better yielding varieties. These factors resulted in high production levels and fruit exports  thereof.  However,  important  seasonal  and  annual  variation  of  fruit  supplies continues to characterize prices at both wholesale and consumption levels. To study the  response  of  peach  production  an  econometric  model  was  developed. Modelling  was carried out in two stages. First area variation was explained through new plantings and removals and second yield variation was analyzed. The methodological approach followed takes into account the characteristics and...
Tipo: Journal Article
Palavras-chave: Supply response; Modeling; Price expectations; Peaches; Demand and Price Analysis.
Ano: 2009
URL: http://purl.umn.edu/93801

Model, Model on the Screen, What's the Cost of Going Green?
Provedor de dados: 31
Autores: Dowlatabadi,   Hadi; Boyd,   David R.; MacDonald,   Jamie.
How much a policy is expected to cost and who bears the brunt of that cost play a significant role in the debates that shape regulations. We do not have a good track record of predicting costs and their ultimate distribution, but systematic reviews of past assessments have identified some of the factors that lead to errors. A wide range of expected costs of climate policy have been hotly debated, but all are likely to be wrong. This does not mean that we should continue a debate using ill-informed analyses. On the contrary, we need early small experiments to shed light on key unknowns. Environmental stewardship is a long-term challenge and an adaptive regulatory approach promises to inform policy targets and improve controls through sequential regulatory...
Tipo: Working or Discussion Paper
Palavras-chave: Cost estimation; Climate policy; Modeling; Adaptive management; Environmental Economics and Policy; D21; D82; D83; F13; O31.
Ano: 2004
URL: http://purl.umn.edu/10806

Calibration and Validation of SWAT for the Upper Maquoketa River Watershed
Provedor de dados: 31
Autores: Kanwar,   Ramesh S.; Reungsang,   Pipat; Jha,   Manoj K.; Gassman,   Philip W.; Ahmad,   Khalil; Saleh,   Ali.
A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which...
Tipo: Working or Discussion Paper
Palavras-chave: Calibration; Modeling; Nitrate; SWAT; Validation; Water quality; Resource /Energy Economics and Policy.
Ano: 2005
URL: http://purl.umn.edu/18440

Modeling Linkages Between Climate Policy and Land Use: An Overview
Provedor de dados: 31
Autores: van der Werf,   Edwin; Peterson,   Sonja.
Agriculture and forestry play an important role in emitting and storing greenhouse gases. For an efficient and cost-effective climate policy it is therefore important to explicitly include land use, land use change, and forestry (LULUCF) in economy-climate models. This paper gives an overview and assessment of existing approaches to include land use, land-use change, and forestry into climate-economy models or to link economy-climate models to land-use models.
Tipo: Working or Discussion Paper
Palavras-chave: Climate Change; Climate Policy; Modeling; Land Use; Environmental Economics and Policy; Land Economics/Use; Q23; Q24; Q25; Q42.
Ano: 2007
URL: http://purl.umn.edu/9545

Sny Magill Watershed Modeling Project: Final Report
Provedor de dados: 31
Autores: Saleh,   Ali; Gassman,   Philip W.; Kling,   Catherine L.
Replaced with revised version of paper 10/29/08.
Tipo: Working or Discussion Paper
Palavras-chave: BMP; Land use; Modeling; Nutrient management; Water quality; Watershed; Resource /Energy Economics and Policy.
Ano: 2006
URL: http://purl.umn.edu/18666

Integrated Assessment Modelling of Complexity in the New Zealand Farming Industry
Provedor de dados: 31
Autores: Olubode-Awosola,   Femi.
As New Zealand farming industry pursues more productivity this has implication for environment and makes land use and agricultural policy decision processes more complex for which integrated assessment modeling (IAM) can support. The purpose of this review paper is to propose means through which IAM can be improved specifically to minimize uncertainties and increase relevance, reliability, and utility of outputs of different models. Literature suggests that the general motivation for land use change is that farmers do consider the environment, but need to maintain profitability. There are handful decision support tools for land use and land policy decisions but one common feature of most of the models is that each seems suitable for only a part of the...
Tipo: Conference Paper or Presentation
Palavras-chave: Integrated assessment; Modeling; Complexity; Farming industry; New Zealand; Agribusiness; Land Economics/Use.
Ano: 2011
URL: http://purl.umn.edu/115404

Measuring Competition between Non-Food and Food Demand on World Grain Markets : Is Biofuel Production Compatible with Pressure for Food Production ?
Provedor de dados: 31
Autores: Benjamin,   Catherine; Houee-Bigot,   Magalie.
The flow of agricultural products between countries is conditioned by several factors including domestic and trade policy tools for the main competing exporters countries, and macroeconomic variables (such as real income per capita, rate of population growth,etc). Important structural changes are occurring on world agricultural markets that will have an impact on the long term competitiveness of countries and regions. These changes include developments in biofuels production linked to policy incentives, and the rapid growth in income and population numbers in some developing countries (such as India and China). An important issue is to identify the factors that are going to modify the balance between the supply and demand for agricultural products in the...
Tipo: Conference Paper or Presentation
Palavras-chave: Modeling; Econometric; Partial equilibrium; Land uses; Biofuels; Demand and Price Analysis; International Relations/Trade.
Ano: 2007
URL: http://purl.umn.edu/9854

Sugar Market Liberalization: Modeling the EU Supply of "C" Sugar
Provedor de dados: 31
Autores: Gohin,   Alexandre; Bureau,   Jean-Christophe.
The various assessments of the effects of a liberalization of world sugar markets are largely inconsistent. One cause seems to be the modeling of the EU supply response. We investigate three possible linkages between production quota sugar and the out-of-quota or "C" sugar supply: i/ the existence of fixed costs covered by the in-quota sugar; ii /the "overshooting" behavior as prevention against poor yields; iii/ the production of C sugar as "reference building" in view of expected reforms. Modeling these effects results in the introduction of an implicit cross-subsidy between in quota sugar and C sugar. The resulting specification is included in a detailed model of EU agricultural sector so as to account for intersectoral linkages. We simulate the effects...
Tipo: Conference Paper or Presentation
Palavras-chave: Common Agricultural Policy; Sugar; Modeling; General equilibrium models; Agricultural and Food Policy; D58; Q17; Q18.
Ano: 2005
URL: http://purl.umn.edu/24740

The Structural Estimation of Principal-Agent Models by Least Squares: Evidence from Land Rental Markets in Madagascar (PowerPoint)
Provedor de dados: 31
Autores: Brown,   Zachary S.; Bellemare,   Marc F.
Tipo: Conference Paper or Presentation
Palavras-chave: Modeling; Least squares; Madagascar; Land rental markets; Risk and Uncertainty.
Ano: 2009
URL: http://purl.umn.edu/48908

Simulation in inventory management
Provedor de dados: 31
Autores: Marcikic,   Aleksandra; Radovanov,   Boris.
In this paper inventory management is analyzed as an organic part of the supply chain managing process. In today’s competitive economic environment traditional inventory policies should be improved. Simulation models enable a priori managing and analyzing variety of possible results and implication of selected inventory policies. The model presented in this paper uses the Monte Carlo simulation method and variables taken as random, in order to depict a harmonization and integration of dynamic quantitative analysis and theoretical, qualitative concepts of inventory management.
Tipo: Journal Article
Palavras-chave: Monte Carlo simulation; Modeling; Inventory management; Supply chain management.; Research and Development/Tech Change/Emerging Technologies; C15; C63.
Ano: 2009
URL: http://purl.umn.edu/94592

Evaluation of EPIC for Three Minnesota Cropping Systems
Provedor de dados: 31
Autores: Chung,   S.W.; Gassman,   Philip W.; Huggins,   David R.; Randall,   G.W.
The Erosion Productivity Impact Calculator (EPIC) model was tested using four years of field data collected at a site near Lamberton, Minnesota, under three different crop rotations: continuous corn (Zea mays L.) or CC, soybean (Glycine max L.)-corn (SC), continuous alfalfa (Medicago sativa L.) or CA. The model was evaluated by comparing measured versus predicted subsurface drainage flow (tile flow), nitrate-nitrogen (NO3-N) loss in tile flow, residual NO3-N in the soil profile, crop N uptake, and yield. Initially, EPIC was run using standard Soil Conservation Service (SCS) runoff curve numbers (CN2) suggested for the soil type at the site. Two different SC runs were performed with a nitrogen fixation parameter denoted as parm(7) set at either 1.0 or 0.3,...
Tipo: Working or Discussion Paper
Palavras-chave: Modeling; Water quality; Crop rotation; Tile drainage; Nitrate leaching; Fertilizer; Crop Production/Industries.
Ano: 2000
URL: http://purl.umn.edu/18479

Economic Modeling of Livestock Disease Outbreaks
Provedor de dados: 31
Autores: Paarlberg,   Philip L.; Lee,   John G.; Seitzinger,   Ann Hillberg.
The paper surveys articles examining the economic impacts of a livestock disease outbreak and focuses on modeling issues. One set of papers considers setting an import barrier when there is a livestock disease risk. They show that the level of a risk-based import barrier is sensitive to the impact of disease on economic welfare. The remaining articles focus on estimates of the economic impacts. An outbreak is modeled in a U.S. agricultural sector model and shows the importance of lost exports and consumer response to the magnitude of losses. The final paper argues for de-composition of the welfare impacts. Lessons for future research include improved links to epidemiological research, improved inclusion of trade, extension to non-agricultural sectors, and...
Tipo: Journal Article
Palavras-chave: Foot-and-mouth disease; Modeling; Trade; Livestock Production/Industries.
Ano: 2005
URL: http://purl.umn.edu/8178

Historical Development and Applications of the EPIC and APEX Models
Provedor de dados: 31
Autores: Gassman,   Philip W.; Williams,   Jimmy R.; Benson,   Verel W.; Izaurralde,   R. Cesar; Hauck,   Larry M.; Jones,   C. Allan; Atwood,   Jay D.; Kiniry,   James R.; Flowers,   Joan D.
The development of the field-scale Erosion Productivity Impact Calculator (EPIC) model was initiated in 1981 to support assessments of soil erosion impacts on soil productivity for soil, climate, and cropping conditions representative of a broad spectrum of U.S. agricultural production regions. The first major application of EPIC was a national analysis performed in support of the 1985 Resources Conservation Act (RCA) assessment. The model has continuously evolved since that time and has been applied for a wide range of field, regional, and national studies both in the U.S. and in other countries. The range of EPIC applications has also expanded greatly over that time, including studies of (1) surface runoff and leaching estimates of nitrogen and...
Tipo: Working or Discussion Paper
Palavras-chave: APEX; Carbon sequestration; Climate change; EPIC; Modeling; Soil erosion; Water quality; Research Methods/ Statistical Methods.
Ano: 2005
URL: http://purl.umn.edu/18372

Modeling energy utilization in broiler breeders, laying hens and broilers
Provedor de dados: 89
Autores: Sakomura,NK.
The factorial approach has been used to partition the energy requirements into maintenance, growth, and production. The coefficients determined for these purposes can be used to elaborate energy requirement models. These models consider the body weight, weight gain, egg production, and environmental temperature to determine the energy requirements for poultry. Predicting daily energy requirement models can help to establish better and more profitable feeding programs for poultry. Studies were conducted at UNESP-Jaboticabal to determine metabolizable energy (ME) requirement models for broiler breeders, laying hens, and broilers. These models were evaluated in performance trials and provided good adjustments. Therefore, they could be used to establish...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Broilers; Broiler breeders; Energy metabolism; Energy requirement; Factorial approach; Laying hens; Modeling.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2004000100001

Boundary Line Model to Estimate the Nutrient Sufficiency Range in Muskmelon Leaves
Provedor de dados: 90
Autores: Maia,Celsemy Eleutério; Morais,Elis Regina Costa de.
ABSTRACT: The boundary line is a method frequently used to assess the nutritional status of plants when the relationship between the variables under analysis is influenced by other interacting factors. The objective of this study was to propose and test the boundary line model to estimate the nutrient sufficiency range and nutritional status of irrigated muskmelon. The lower and upper limits of the sufficiency range were calculated as a basis for assessment of the nutritional status of muskmelon. Leaf material was collected from 70 muskmelon crop areas in northern Brazil. The nutrient (N, P, K, Ca, Mg, S, Fe, Zn, Mn, B, and Cu) concentrations in the leaf tissue and the respective fruit yield of each area were measured. The proposed model to estimate the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Nutritional evaluation; Leaf analysis.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100553

Soil thermal diffusivity estimated from data of soil temperature and single soil component properties
Provedor de dados: 90
Autores: Jong van Lier,Quirijn de; Durigon,Angelica.
Under field conditions, thermal diffusivity can be estimated from soil temperature data but also from the properties of soil components together with their spatial organization. We aimed to determine soil thermal diffusivity from half-hourly temperature measurements in a Rhodic Kanhapludalf, using three calculation procedures (the amplitude ratio, phase lag and Seemann procedures), as well as from soil component properties, for a comparison of procedures and methods. To determine thermal conductivity for short wave periods (one day), the phase lag method was more reliable than the amplitude ratio or the Seemann method, especially in deeper layers, where temperature variations are small. The phase lag method resulted in coherent values of thermal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil thermal properties; Modeling.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000100011

FERTILIZER RECOMMENDATION SYSTEM FOR MELON BASED ON NUTRITIONAL BALANCE
Provedor de dados: 90
Autores: Deus,José Aridiano Lima de; Soares,Ismail; Neves,Júlio César Lima; Medeiros,José Francismar de; Miranda,Fábio Rodrigues de.
Melon is one of the most demanding cucurbits regarding fertilization, requiring knowledge of soils, crop nutritional requirements, time of application, and nutrient use efficiency for proper fertilization. Developing support systems for decision-making for fertilization that considers these variables in nutrient requirement and supply is necessary. The objective of this study was parameterization of a fertilizer recommendation system for melon (Ferticalc-melon) based on nutritional balance. To estimate fertilizer recommendation, the system considers the requirement subsystem (REQ), which includes the demand for nutrients by the plant, and the supply subsystem (SUP), which corresponds to the supply of nutrients through the soil and irrigation water. After...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cucumis melo L; Nutrient demand; Nutrient supply; Modeling.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000200498

BEYOND THE “LEAST LIMITING WATER RANGE”: RETHINKING SOIL PHYSICS RESEARCH IN BRAZIL
Provedor de dados: 90
Autores: van Lier,Quirijn de Jong; Gubiani,Paulo Ivonir.
As opposed to objective definitions in soil physics, the subjective term “soil physical quality” is increasingly found in publications in the soil physics area. A supposed indicator of soil physical quality that has been the focus of attention, especially in the Brazilian literature, is the Least Limiting Water Range (RLL), translated in Portuguese as "Intervalo Hídrico Ótimo" or IHO. In this paper the four limiting water contents that define RLLare discussed in the light of objectively determinable soil physical properties, pointing to inconsistencies in the RLLdefinition and calculation. It also discusses the interpretation of RLL as an indicator of crop productivity or soil physical quality, showing its inability to consider common phenological and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Field capacity; Drought stress; Mechanical stress; Anoxic stress.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000400925

Daycent Simulation of Methane Emissions, Grain Yield, and Soil Organic Carbon in a Subtropical Paddy Rice System
Provedor de dados: 90
Autores: Weiler,Douglas Adams; Tornquist,Carlos Gustavo; Zschornack,Tiago; Ogle,Stephen Michael; Carlos,Filipe Selau; Bayer,Cimélio.
ABSTRACT The DayCent ecosystem model, widely tested in upland agroecosystems, was recently updated to simulate waterlogged soils. We evaluated the new version in a paddy rice experiment in Southern Brazil. DayCent was used to simulate rice yield, soil organic carbon (SOC), and soil CH4 fluxes. Model calibration was conducted with a multiple-year dataset from the conventional tillage treatment, followed by a validation phase with data from the no-tillage treatment. Model performance was assessed with statistics commonly used in modeling studies: root mean square error (RMSE), model efficiency (EF), and mean difference (M). In general, DayCent slightly underestimated rice yields under no-tillage (by 0.07 Mg ha-1, or 9.2 %) and slightly overestimated soil C...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Soil potential redox; Flooded soil; Greenhouse gas; Soil tillage.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100523

Remaining phosphorus estimated by pedotransfer function
Provedor de dados: 90
Autores: Cagliari,Joice; Veronez,Maurício Roberto; Alves,Marcelo Eduardo.
Although the determination of remaining phosphorus (Prem) is simple, accurate values could also be estimated with a pedotransfer function (PTF) aiming at the additional use of soil analysis data and/or Prem replacement by an even simpler determination. The purpose of this paper was to develop a pedotransfer function to estimate Prem values of soils of the State of São Paulo based on properties with easier or routine laboratory determination. A pedotransfer function was developed by artificial neural networks (ANN) from a database of Prem values, pH values measured in 1 mol L-1 NaF solution (pH NaF) and soil chemical and physical properties of samples collected during soil classification activities carried out in the State of São Paulo by the Agronomic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Artificial neural networks; Modeling; Multiple regression analysis.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000100019

Fertilization response likelihood for the interpretation of leaf analyses
Provedor de dados: 90
Autores: Maia,Celsemy Eleutério.
Leaf analysis is the chemical evaluation of the nutritional status where the nutrient concentrations found in the tissue reflect the nutritional status of the plants. Thus, a correct interpretation of the results of leaf analysis is fundamental for an effective use of this tool. The purpose of this study was to propose and compare the method of Fertilization Response Likelihood (FRL) for interpretation of leaf analysis with that of the Diagnosis and Recommendation Integrated System (DRIS). The database consisted of 157 analyses of the N, P, K, Ca, Mg, S, Cu, Fe, Mn, Zn, and B concentrations in coffee leaves, which were divided into two groups: low yield (&lt; 30 bags ha-1) and high yield (&amp;gt; 30 bags ha-1). The DRIS indices were calculated using the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Nutritional status; DRIS.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000200013

Method to estimate soil macroporosity and microporosity based on sand content and bulk density
Provedor de dados: 90
Autores: Stolf,Rubismar; Thurler,Álvaro de Mendonça; Bacchi,Osny Oliveira Santos; Reichardt,Klaus.
Macroporosity is often used in the determination of soil compaction. Reduced macroporosity can lead to poor drainage, low root aeration and soil degradation. The aim of this study was to develop and test different models to estimate macro and microporosity efficiently, using multiple regression. Ten soils were selected within a large range of textures: sand (Sa) 0.07-0.84; silt 0.03-0.24; clay 0.13-0.78 kg kg-1 and subjected to three compaction levels (three bulk densities, BD). Two models with similar accuracy were selected, with a mean error of about 0.02 m³ m-3 (2 %). The model y = a + b.BD + c.Sa, named model 2, was selected for its simplicity to estimate Macro (Ma), Micro (Mi) or total porosity (TP): Ma = 0.693 - 0.465 BD + 0.212 Sa; Mi = 0.337 +...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Degree of compaction; Modeling; Macropore; Texture; Maximum bulk density; Relative bulk density.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000200014

Comparing the artificial neural network with parcial least squares for prediction of soil organic carbon and pH at different moisture content levels using visible and near-infrared spectroscopy
Provedor de dados: 90
Autores: Tekin,Yücel; Tümsavas,Zeynal; Mouazen,Abdul Mounem.
Visible and near infrared (vis-NIR) spectroscopy is widely used to detect soil properties. The objective of this study is to evaluate the combined effect of moisture content (MC) and the modeling algorithm on prediction of soil organic carbon (SOC) and pH. Partial least squares (PLS) and the Artificial neural network (ANN) for modeling of SOC and pH at different MC levels were compared in terms of efficiency in prediction of regression. A total of 270 soil samples were used. Before spectral measurement, dry soil samples were weighed to determine the amount of water to be added by weight to achieve the specified gravimetric MC levels of 5, 10, 15, 20, and 25 %. A fiber-optic vis-NIR spectrophotometer (350-2500 nm) was used to measure spectra of soil samples...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Modeling; Prediction; Vis-NIR.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000600014

Drying kinetics of atemoya pulp
Provedor de dados: 91
Autores: Galdino,Plúvia O.; Figueirêdo,Rossana M. F. de; Queiroz,Alexandre J. de M.; Galdino,Pablícia O.
ABSTRACT This study was conducted in order to obtain drying curves of whole atemoya pulp through the foam-mat drying method. The suspension was prepared with whole atemoya pulp mixed with 2% of Emustab® and 2% of Super Liga Neutra® with mixing time of 20 min, and dried in a forced-air oven at different temperatures (60; 70 and 80 °C) and thicknesses of the foam layer (0.5, 1.0 and 1.5 cm). The drying rate curves were plotted against the water content ratio and the semi-theoretical models of Henderson &amp; Pabis, Page and Midilli were used. All tested models showed coefficient of determination (R2) above 0.993, and the Midilli model showed the best fit for all conditions. Drying curves were affected by temperature and layer thickness.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Annona cherimoya Mill. x Annona squamosa L.; Dehydration; Modeling.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000700672

Periods of constant and falling-rate for infrared drying of carrot slices
Provedor de dados: 91
Autores: Botelho,Fernando M.; Corrêa,Paulo C.; Goneli,André. L. D.; Martins,Márcio A.; Magalhães,Felipe E. A.; Campos,Sílvia C.
The aim of this work was to study the infrared drying process of carrot slices and to determine coefficients related to the heat and mass transfer of the process. Fresh carrots were used, dried until constant weight in a dryer with infrared heating source. Different models were utilized to fit the experimental data of constant and falling drying rate periods. It was verified that the coefficients of heat and mass transfer, during the constant drying rate, significantly increased with temperature on rise. The Diffusion Approximation, Two Terms, Midili and Verna models satisfactory represented the falling period of drying rate of carrot slices. The effective diffusion coefficient increased with temperature and this relationship can be represented by the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Dehydration; Water diffusion.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662011000800012

Performance of different methods for reference evapotranspiration estimation in Jaíba, Brazil
Provedor de dados: 91
Autores: Silva,Gustavo H. da; Dias,Santos H. B.; Ferreira,Lucas B.; Santos,Jannaylton É. O.; Cunha,Fernando F. da.
ABSTRACT FAO Penman-Monteith (FO-PM) is considered the standard method for the estimation of reference evapotranspiration (ET0) but requires various meteorological data, which are often not available. The objective of this work was to evaluate the performance of the FAO-PM method with limited meteorological data and other methods as alternatives to estimate ET0 in Jaíba-MG. The study used daily meteorological data from 2007 to 2016 of the National Institute of Meteorology’s station. Daily ET0 values were randomized, and 70% of these were used to determine the calibration parameters of the ET0 for the equations of each method under study. The remaining data were used to test the calibration against the standard method. Performance evaluation was based on...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Missing data; Modeling; Irrigation management; FAO-Penman-Monteith.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000200083

Non-destructive models for leaf area determination in canola
Provedor de dados: 91
Autores: Tartaglia,Francilene de L.; Righi,Evandro Z.; Rocha,Leidiana da; Loose,Luis H.; Maldaner,Ivan C.; Heldwein,Arno B.
ABSTRACT The leaf is a very important structure of the plants, since it allows gas exchanges and the transformation of light energy into chemical energy. This study aimed to generate and test mathematical models for leaf area estimation in canola based on leaf dimensions. Two experiments were conducted with canola in 2014, in which leaves were collected in different phenological stages with different sizes and shapes. Subsequently, leaf length, width and area were measured (with automatic meter) in 606 leaves, which included 371 ovate and 235 lanceolate leaves. The models were generated using length, width and length versus width as independent variables and leaf area as dependent variable. The models were validated using a group of leaves different from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brassica napus; Ovate leaves; Lanceolate leaves; Modeling.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000600551

Simulation of wheat yield by nitrogen and nonlinearity of environmental conditions
Provedor de dados: 91
Autores: Trautmann,Ana P. B.; Silva,José A. G. da; Binelo,Manuel O.; Valdiero,Antonio C.; Henrichsen,Luana; Basso,Natiane C. F.
ABSTRACT Fuzzy logic can simulate wheat productivity by assisting crop predictability. The objective of the study is the use of fuzzy logic to simulate wheat yield in the conditions of nitrogen use, together with the effects of air temperature and rainfall, in the main cereal succession systems in Southern Brazil. The study was conducted in the years 2014, 2015 and 2016, in Augusto Pestana, RS, Brazil. The experimental design was a randomized block design with four repetitions in a 4 x 3 factorial scheme for N-fertilizer doses (0, 30, 60, 120 kg ha-1) and nutrient supply forms [100% in phenological stage V3 (third expanded leaf); (70%/30%) in the phenological stage V3/V6 (third and sixth expanded leaf) and; fractionated (70%/30%) at the phenological stage...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Triticum aestivum; Temperature; Precipitation; Fuzzy logic; Modeling.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662020000100044

New occurrence and potential distribution of Anastrepha zacharyi (Diptera: Tephritidae) in the Eastern Amazon
Provedor de dados: 92
Autores: Soares,Jefferson Bruno Carvalho; Santos Junior,Cezário Ferreira dos; Miranda,Leonardo de Sousa; Godoy,Mauricio Sekiguchi de; Souza-Filho,Miguel Francisco de; Lemos,Walkymário de Paulo; Silva,Anderson Gonçalves da.
Abstract The species Anastrepha zacharyi Norrbom has recently been recorded in the Amazon, however the species is subsampling in the biome. In this research, we report a new occurrence of A. zacharyi in the state of Pará and, through climate suitability modelling, present new possible distribution areas of the species in the Brazilian eastern Amazon.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Habitat; Insect pest; Modeling; Fruit fly.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262020000100210

Requirement for maintenance and gain of crude protein for two genotypes of growing quails
Provedor de dados: 96
Autores: Jordão Filho,José; Silva,José Humberto Vilar da; Costa,Fernando Guilherme Perazzo; Albino,Luiz Fernando Teixeira; Melo,Thiago de Sousa; Lacerda,Patrícia Barbosa de; Dantas,Gabriela Mafra; Soares,Rejane Pontes.
The objective of this study was to estimate the requirements for maintenance and gain of crude protein in Japanese and European quails aged 16-36 days. To determine the maintenance requirements, one experiment was conducted in a completely randomized design with four decreasing feeding levels (100, 75, 50 and 25%) and four replicates per treatment. The method of comparative slaughter was used, through a feeding assay. A total of 352 quails from each strain were housed by supply level in 16 pens measuring 1.0 × 1.5 m, totaling 22 birds per cage under ambient temperature conditions (26±0.5 ºC). To estimate the requirement gains, one experiment was conducted with five groups of quails fed ad libitum and housed under controlled temperature of 18 ºC. All...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Growth; Modeling; Protein; Quail genotypes.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000900012

Energy requirement for maintenance and gain for two genotypes of quails housed in different breeding rearing systems
Provedor de dados: 96
Autores: Jordão Filho,José; Silva,José Humberto Vilar da; Silva,Cidinei Trajano; Costa,Fernando Guilherme Perazzo; Sousa,Janaína Maria Batista de; Givisiez,Patrícia Emília Naves.
This study aimed to estimate the energy requirements for maintenance and gain of Japanese and European quails under growth housed in two rearing systems: floor pens and cages. To determine maintenance requirements, two experiments were conducted with birds housed in cages in environmental chambers (experiment 1) and in floor pens at room temperature conditions (experiment 2). The experimental design was completely randomized with four levels of feed supply (100, 75, 50 and 25%) and four repetitions. Energy requirements for maintenance were estimated by the comparative slaughter method through a feeding trial. In experiment 1, 64 Japanese and European quails per treatment were housed in cages of climatic chambers at 18, 24, and 28 °C, while in experiment 2,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Breeding system; Energy; Modeling; Temperature.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011001100019

Estimate of the optimal level of concentrates for dairy cows on tropical pastures by using the concept of marginal analysis
Provedor de dados: 96
Autores: Oliveira,André Soares de; Campos,José Maurício de Souza; Lana,Rogério de Paula; Detmann,Edenio; Valadares Filho,Sebastião de Campos.
It was adopted in this work a methodology to estimate the optimal level of concentrate food for dairy cows on tropical pastures based on the theory of marginal analysis. An empiric model was developed and validated for application of the methodology using a database composed of 62 means of treatments from 32 studies in which milk production was evaluated regarded to the levels of concentrate feeding. Milk production (MP) showed quadratic behavior in response to concentrate intake (CI): MP (kg/cow/day) = 10.554 + 1.5855CI - 0.0552CI². Evaluation of the MP values observed over the predicted ones pointed the non-rejection of the null hypothesis, indicating that the model can be applied on the prediction of milk production, and consequently, on the optimal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Marginal production response; Milk production; Modeling; Optimization.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000900024

Evaluation of a dynamic simulation model for milk production systems
Provedor de dados: 96
Autores: Cunha,Daniel de Noronha Figueiredo Vieira da; Pereira,José Carlos; Campos,Oriel Fajardo de; Braga,José Luis; Silva,Fabyano Fonseca e; Martuscello,Janaina Azevedo.
The objective of this study was to develop and to evaluate a dynamic simulation model, with stochastic components in order to assess milk production systems. The simulation model was developed by using STELLA 9.0, ZooCalc 1.0 and electronic data sheets. The physical structure of the herd was divided into 15 interlinked modules that represented categories or subdivisions of categories. Mathematical models obtained from the literature were used to simulate the body weight of growing and lactating animals and milk production and milk composition. Electronic data sheets were used to calculate the nutritional requirements and dietary balance. After cost minimization, each feed was evaluated by using ZooCalc 1.0. Some average responses of farm size, zootechnical...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dairy cattle; Modeling.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000400027

Simulation and economic analysis of bovine sex selection
Provedor de dados: 96
Autores: Beltrame,Renato Travassos; Quirino,Celia Raquel; Barioni,Luís Gustavo; Lima,Vera Fernanda Martins Hossepian de.
A simulation model implemented in the programming software Delphi XE® was applied to evaluate sex selection in bovine. The hypothesis under investigation was that a dynamic model with stochastic and deterministic elements could detect the sexed semen technique to minimize pregnancy cost and to determine the adequate number of recipients required for in vivo (ET) and in vitro embryo production (IVP) in the proposed scenarios. Sex selection was compared through semen sexed using flow cytometry (C1) and density gradient centrifugation techniques (C2) in ET and IVP. Sensibility analyses were used to identify the adequate number of recipients for each scenario. This number was reinserted into the model to determine the biological and financial values that...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Beef cattle; In vitro fertilization; Modeling; Stochastic simulation.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000500003

A model for evaluating beef cattle rations considering effects of ruminal fiber mass
Provedor de dados: 96
Autores: Henrique,Douglas Sampaio; Lana,Rogério de Paula; Vieira,Ricardo Augusto Mendonça; Fontes,Carlos Augusto de Alencar; Botelho,Mosar Faria.
A mathematical model based on Cornell Net Carbohydrate and Protein System (CNCPS) was developed and adapted in order to evaluate beef cattle rations at tropical climate conditions. The presented system differs from CNCPS in the modeling of insoluble particles' digestion and passage kinetics, which enabled the estimation of fiber mass in rumen and its effects on animal performance. The equations used to estimate metabolizable protein and net energy requirements for gain, net energy requirement for maintenance and total efficiency of metabolizable energy utilization were obtained from scientific articles published in Brazil. The parameters of the regression equations in these papers were estimated using data from Bos indicus purebred and crossbred animals...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Nutrition; Ruminants.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011001100036

Evaluation of mathematical models to describe growth of grazing young bulls
Provedor de dados: 96
Autores: Fernandes,Henrique Jorge; Tedeschi,Luis Orlindo; Paulino,Mário Fonseca; Detmann,Edenio; Paiva,Luisa Melville; Valadares Filho,Sebastião de Campos; Silva,Aline Gomes da; Azevêdo,José Augusto Gomes.
The objective of this study was to evaluate the use of different mathematical models to describe growth of grazing beef cattle. Data of 20 Nellore bulls with initial weight of 129±28.1 kg and final weight of 405±62.0 kg were used. The animals were randomly divided into four plots and placed on B. decumbens Stapf pastures. Three plots received concentrate supplement with different protein profiles and the fourth plot received only mineral supplement. Animals were weighed every 28 days to design growth curve of full body weight. Five mathematical models were evaluated to describe animal growth: Multiphase, Linear, Logarithmic, Gompertz and Logistic models. Assessment of adequacy of the models was performed by using coefficient of determination, simultaneous...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Grazing beef cattle; Modeling; Seasonality.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000200020

Prediction equations to estimate the demand of energy and crude protein for maintenance, gain and egg production for laying Japanese quails
Provedor de dados: 96
Autores: Jordão Filho,José; Silva,José Humberto Vilar da; Costa,Fernando Guilherme Perazzo; Sakomura,Nilva Kazue; Silva,Cidinei Trajano; Chagas,Nalberlania Alves.
The study was conducted to estimate requirements of energy and crude protein for maintenance, weight gain and egg production of Japanese quails in the period of 67 to 107 days of age. Two experiments were performed: one, to determine the requirements for maintenance of protein, and the other, for energy. Experiments were conducted in a completely randomized design with four dietary levels of offer and four replicates of six birds. The diets offered were: ad libitum (100%), 75%, 50%, and 25% consumption ad libitum (below maintenance). The methodology used to estimate the demand for maintenance was the comparative slaughter. For estimation of the requirement for weight gain, eight groups of 15 quails were reared separately, fed ad libitum and housed under 22...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Egg production; Energy; Modeling; Protein.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011001100020

Phenotypic study of egg production curve in commercial broiler breeders using Compartmental function
Provedor de dados: 96
Autores: Safari-Aliqiarloo,Abbas; Zare,Masoomeh; Faghih-Mohammadi,Farhang; Seidavi,Alireza; Laudadio,Vito; Selvaggi,Maria; Tufarelli,Vincenzo.
ABSTRACT The objective of this study was to analyze the effect of environmental factors on egg production curve traits in broiler breeders. The weekly egg production records of birds collected from four different flocks were used to estimate the egg production curve parameters using the Compartmental function (y = A(1 − exp−b(t − d))exp−ct). The coefficient of determination (R2) obtained by the model was 0.98. Least squares analysis of variance indicated that the environmental factors such as hatchability and flock had significant effects on egg production curve traits. The highest correlation was observed between the weekly potential maximum yield and yield at the beginning of laying, whereas the lowest correlation was found between the weekly potential...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Equation; Modeling; Poultry.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100517

Application of a precision nutrition tool for growing and finishing pigs
Provedor de dados: 96
Autores: Lovato,Gustavo Dias; Vale,Marcos Martinez do; Oliveira,Vladimir de; Klein,Daniela Regina; Branco,Tatiane.
ABSTRACT The objective of this study was to evaluate a growth model applied to adjust nutritional programs for growing and finishing pigs, in a commercial production context. The phase I (calibration) was conducted in a commercial pig production unit. The data were collected from a nutritional program, a feed program, and an animal profile. In experimental phase II, these data were entered in the InraPorc® model for simulations and to propose adjustments to the commercial nutritional program. Afterwards, the conventional nutritional program (CNP) and the adjusted nutritional program (ANP) were compared with InraPorc® simulation. Animal profile was collected by weighing 30% of pigs per stall and monitoring their feed intake in each stage. Four hundred and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: InraPorc®; Modeling; Pig production; Temperature.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000900755

Nonlinear models for fitting growth curves of Nellore cows reared in the Amazon Biome
Provedor de dados: 96
Autores: Marinho,Kedma Nayra da Silva; Freitas,Alfredo Ribeiro de; Falcão,Alencariano José da Silva; Dias,Francisca Elda Ferreira.
Growth curves of Nellore cows were estimated by comparing six nonlinear models: Brody, Logistic, two alternatives by Gompertz, Richards and Von Bertalanffy. The models were fitted to weight-age data, from birth to 750 days of age of 29,221 cows, born between 1976 and 2006 in the Brazilian states of Acre, Amapá, Amazonas, Pará, Rondônia, Roraima and Tocantins. The models were fitted by the Gauss-Newton method. The goodness of fit of the models was evaluated by using mean square error, adjusted coefficient of determination, prediction error and mean absolute error. Biological interpretation of parameters was accomplished by plotting estimated weights versus the observed weight means, instantaneous growth rate, absolute maturity rate, relative instantaneous...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Beef cattle; Maturity rate; Modeling.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000900006

Models for estimating feed intake in small ruminants
Provedor de dados: 96
Autores: Pulina,Giuseppe; Avondo,Marcella; Molle,Giovanni; Francesconi,Ana Helena Dias; Atzori,Alberto Stanislao; Cannas,Antonello.
This review deals with the most relevant limits and developments of the modeling of intake of sheep and goats reared intensively and extensively. Because small ruminants are normally fed ad libitum, voluntary feed intake is crucial in feeding tactics and strategies aimed at optimal animal production. The effects of genetic, neuroendocrine, hormonal, feed and environmental factors on voluntary feed intake were discussed. Then, several mathematical models to estimate dry matter intake (DMI) were examined, with emphasis on empirical models for sheep and goats in intensive farm systems or in extensive areas under pasture or rangeland conditions. A sensitivity analysis of four models of prediction of DMI in housed lactating dairy sheep and meat sheep breeds was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dry matter intake; Feedlot; Goats; Grazing; Modeling; Sheep.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000900010

Selection of models of lactation curves to use in milk production simulation systems
Provedor de dados: 96
Autores: Cunha,Daniel de Noronha Figueiredo Vieira da; Pereira,José Carlos; Silva,Fabyano Fonseca e; Campos,Oriel Fajardo de; Braga,José Luis; Martuscello,Janaina Azevedo.
The objective of this study was to select models of lactation curves with a better adjustment to the observed data in models of milk production simulation systems. A data base on 6,459 recordings of daily milk production was used. These data were obtained from monthly and fortnightly controls of milk between 2004 and 2007, from 472 lactations of animals from ten different milking cow herd farms. Based on rolling averages of milk production (MP-L/day) per cow, the ten herd farms were divided into low (L &lt; 15), medium (15 &lt;M &lt; 20) and high (H &amp;gt; 20). Data were also divided according to the lactation numbers in first, second, third or greater. Eight lactation curve models commonly used in literature were compared. The models were individually...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dairy cattle; Modeling; Non-linear model.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000400026

Models of protein and amino acid requirements for cattle
Provedor de dados: 96
Autores: Tedeschi,Luis Orlindo; Fox,Danny Gene; Fonseca,Mozart Alves; Cavalcanti,Luigi Francis Lima.
Protein supply and requirements by ruminants have been studied for more than a century. These studies led to the accumulation of lots of scientific information about digestion and metabolism of protein by ruminants as well as the characterization of the dietary protein in order to maximize animal performance. During the 1980s and 1990s, when computers became more accessible and powerful, scientists began to conceptualize and develop mathematical nutrition models, and to program them into computers to assist with ration balancing and formulation for domesticated ruminants, specifically dairy and beef cattle. The most commonly known nutrition models developed during this period were the National Research Council (NRC) in the United States, Agricultural...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Nutrition; Prediction; Ruminants; Simulation.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982015000300109

Equine fecal inoculum optimization in in vitro fermentation assays of dehydrated roughage
Provedor de dados: 96
Autores: Franzan,Bruna Caroline; Franco,Tatiana Werneck; Stefani,Giselle; Pereira,Marcelo Maia; Almeida,Fernando Queiroz de; Silva,Vinicius Pimentel.
ABSTRACT This study evaluated the influence of coastcross hay substrate hydration and equine fecal inoculum dilution on the parameters of fermentation and microbiology in in vitro essays. A 2 × 2 factorial block design was used. The first factor was hydration of the coastcross hay substrate 12 h before incubation or at the time of incubation, and the second factor was the dilution of fecal inoculum with a nutrient solution in a weight: weight ratio of 1:1 or 1:3. Degradation of the dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF) were evaluated at 24, 48, and 72 h. Microorganisms were counted 24 h after inoculation. The ammoniacal nitrogen concentration (NH3-N), pH, and cumulative gas production were measured up to 72 h and adjusted...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Degradation rate; Gas production; Microbiology; Modeling; Roughage.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100531

Optimized feed planning for a grazing horse production systems
Provedor de dados: 96
Autores: Oliveira,José Evandro Gervásio de; Soares,João Batista; Barioni,Luis Gustavo; Leite,Gilberto Gonçalves; Braga,Auro César; Menezes,Marcelo Espellet.
The objective of this study was to develop an economically optimal plan for pasture production and supplementary feeding of horses. The plan was based on the optimization of a multiperiodic linear programming model with the objective of minimizing overall feeding costs, subject to the nutritional constraints of each horse category. The model encompasses a period of one year, from January to December, divided in bimonthly periods. Technical coefficients varied among periods based on local information regarding productivity of the forage crops, taking into account the local climatic conditions and seasonality of production. Literature data on feed nutritional value (crude protein and digestible energy), dry matter intake and nutritional requirements of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Linear programming; Modeling; Ration balancing.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000400030

Sugarcane leaf area index modeling under different soil water conditions
Provedor de dados: 63
Autores: Teruel,D.A.; Barbieri,V.; Ferraro Jr.,L.A.
The knowledge of the Leaf Area Index (LAI) variation during the whole crop cycle is essential to the modeling of the plant growth and development and, consequently, of the crop yield. Sugarcane LAI evolution models were developed for different crop cycles, by adjusting observed LAI values and growing degree-days summation data on a power-exponential function. The resultant equations simulate adequately the LAI behavior during the entire crop cycle. The effect of different water stress levels was calculated in different growth periods, upon the LAI growth The LAI growth deficit was correlated with the ratio between actual evapotranspiration and máximum evapotranspiration, and a constant named kuu was obtained hi each situation. It was noticed that the kLAI...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf Area Index; Sugarcane; Growing degree-days; Water stress; Modeling.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161997000300008

Fractal analysis of agricultural nozzles spray
Provedor de dados: 63
Autores: Agüera,Francisco; Nuyttens,David; Carvajal,Fernando; Sánchez-Hermosilla,Julián.
Fractal scaling of the exponential type is used to establish the cumulative volume (V) distribution applied through agricultural spray nozzles in size x droplets, smaller than the characteristic size X. From exponent d, we deduced the fractal dimension (Df) which measures the degree of irregularity of the medium. This property is known as 'self-similarity'. Assuming that the droplet set from a spray nozzle is self-similar, the objectives of this study were to develop a methodology for calculating a Df factor associated with a given nozzle and to determine regression coefficients in order to predict droplet spectra factors from a nozzle, taking into account its own Df and pressure operating. Based on the iterated function system, we developed an algorithm...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pesticides application; Modeling.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162012000100002

Scientific and technical knowledge of sugarcane cover-management USLE/RUSLE factor
Provedor de dados: 63
Autores: Rocha,Gustavo Casoni da; Sparovek,Gerd.
ABSTRACT: Sugarcane covers 10.6 Mha of Brazilian agricultural land (13 % of all cropland), mainly in the south-central region. In tropical climate conditions, the physiological characteristics of sugarcane allow a wide range of management systems with contrasting soil erosion outcomes. Models can assess these differences and the Universal Soil Loss Equation (USLE) based models are the most frequently used. The cover-management factor (C Factor) is the USLE input variable that represents the changes in soil cover and management. We collected, compared, and evaluated sugarcane C Factor values reported in technical and scientific literature to support modelers and soil scientists on the adequate choice of these values. We analyzed references reporting primary...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bibliometric research; Modeling; Soil loss.
Ano: 2021
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162021000701801

Improving predictions of leaf appearance in field grown potato
Provedor de dados: 63
Autores: Streck,Nereu Augusto; Lago,Isabel; Paula,Fabiana Luiza Matielo de; Bisognin,Dilson Antônio; Heldwein,Arno Bernardo.
The calculation of leaf appearance rate (LAR) and number of accumulated or emerged leaves (NL) on the main stem are part of many crop simulation models. The purpose of this study was to adapt and evaluate a model (WE model) for simulating the main stem LAR and NL in potato (Solanum tuberosum L.). The WE model is a non-linear multiplicative model that takes into account the effect of genotype and environmental factors on LAR. A linear model (Phyllochron model) was also used as a comparison with the WE model. A series of field experiments with 14 planting dates over two years (2003 and 2004) was carried out in Santa Maria, RS, Brazil, using the cultivar Asterix. Coefficients of the WE model and the phyllochron model were estimated with data from four...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Temperature; Leaf development; Phyllochron.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162007000100002

Vadose zone measurement and modeling
Provedor de dados: 63
Autores: Hopmans,J. W.; Clausnitzer,V.; Kosugi,K.I.; Nielsen,D.R.; Somma,F.
The following treatise is a summary of some of the ongoing research activities in the soil physics program at the University of California in Davis. Each of the four listed areas win be presented at the Workshop on special topics on soil physics and crop modeling in Piracicaba at the University of Sao Paulo. We limited ourselves to a general overview of each area, but will present a more thorough discussion with examples at the Workshop.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Unsaturated zone; Water flow; Transport processes; Modeling.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161997000300004

Soil compaction on traffic lane due to soil tillage and sugarcane mechanical harvesting operations
Provedor de dados: 63
Autores: Júnnyor,Wellingthon da Silva Guimarães; Maria,Isabella Clerici De; Araujo-Junior,Cezar Francisco; Lima,Camila Cassante de; Vitti,André César; Figueiredo,Getulio Coutinho; Dechen,Sonia Carmela Falci.
ABSTRACT: Mechanical sugarcane harvesting increases soil compaction due to the intense traffic of agricultural machinery, reducing longevity of sugarcane crops. In order to mitigate the harmful effects caused by agricultural traffic on the soil structure in sugarcane fields, this study evaluated impacts of mechanical sugarcane harvesting on traffic lane under two soil tillage systems based on load bearing capacity models. The experiment was carried out in the region of Piracicaba, state of São Paulo, Brazil, on a Rhodic Nitisol, under conventional tillage (CT) and deep strip-tillage (DST). For CT soil tillage was applied to the entire area with a heavy disk harrow, at operating depths from 0.20 to 0.30 m followed by a leveling harrow at a depth of 0.15 m....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Load bearing capacity; Soil stress distribution; Preconsolidation pressure; Modeling; Environmental sustainability.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001600509

Models to estimate phytomass accumulation of hydroponic lettuce
Provedor de dados: 63
Autores: Lopes,Sidinei José; Dourado Neto,Durval; Manfron,Paulo Augusto; Jasniewicz,Luís Renato.
The protected and hydroponics cultivation are increasing in Brazil, demanding a better knowledge of crop performance in this environment. Plant dry matter accumulation as a function of solar radiation, temperature, relative humidity and other weather parameters in greenhouse is different when compared with field cultivation. With the purpose of proposing models to characterize the temporal variation of leaf and total dry matter production of hydroponics-grown lettuce (Lactuca sativa L.) and to determine the flowering period and the maximum dry matter accumulation rate as a function of plant relative development (relative degree-days), solar radiation and effective thermal index, two experiments (Spring and Autumn) were carried out in the greenhouse, at...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Dry matter; Plastic-greenhouse.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000400007

Dynamic systems approach assess and manage water resources in river basins
Provedor de dados: 63
Autores: Sánchez-Román,Rodrigo Máximo; Folegatti,Marcos Vinicius; Orellana González,Alba María Guadalupe; Silva,Rogério Teixeira da.
The Piracicaba, Capivari and Jundiaí River Basins (RB-PCJ) are located in the States of Minas Gerais and São Paulo, Brazil. By 2005, 5.8% of Brazil's General National Product-GNP was produced there. Such economic development has created a huge demand for water resources. The availability of water resources was assessed by running a dynamic systems simulation model to manage these resources in the RB-PCJ (WRM-PCJ), considering five 50-year simulations. WRM-PCJ was developed as a tool to aid the RB-PCJ Watershed Committee. The model computes water supply, demands, and contamination load from several consumers. When considering a Business-as-Usual scenario, by 2054, water demands will have increased up to 76%, 39% of the available water will come from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water stress; Water management; Watershed; Modeling.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000400001

Logistic rice model for dry matter and nutrient uptake
Provedor de dados: 63
Autores: García y García,Axel; Dourado-Neto,Durval; Basanta,Maria del Valle; López Ovejero,Ramiro Fernando; Favarin,José Laércio.
The temporal variation of cumulative dry matter can be represented by a sigmoidal curve and the temporal variation of nutrient uptake follows this characteristic shape. Therefore, modeling the temporal variation of cumulative dry matter allows estimating nutrient uptake along the crop cycle. The objective of this study was to propose a sine model to estimate dry matter and macronutrient uptake, and to estimate the moments of maximum N and K uptake rates for the rice crop. The field experiment was carried out on a wetland area of Piracicaba, SP, Brazil, consisting of an Humic Haplaquept. The chosen rice variety was IAC 103, a middle season cycle and high yield. Observed variables were dry matter of different plant parts (root, leaf and stem, and panicle)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Sine function; Macronutrients.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000300011

Ballistic model to estimate microsprinkler droplet distribution
Provedor de dados: 63
Autores: Conceição,Marco Antônio Fonseca; Coelho,Rubens Duarte.
Experimental determination of microsprinkler droplets is difficult and time-consuming. This determination, however, could be achieved using ballistic models. The present study aimed to compare simulated and measured values of microsprinkler droplet diameters. Experimental measurements were made using the flour method, and simulations using a ballistic model adopted by the SIRIAS computational software. Drop diameters quantified in the experiment varied between 0.30 mm and 1.30 mm, while the simulated between 0.28 mm and 1.06 mm. The greatest differences between simulated and measured values were registered at the highest radial distance from the emitter. The model presented a performance classified as excellent for simulating microsprinkler drop...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Irrigation; Modeling; Simulation.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000400025

Determination of a long-term optimal irrigation strategy for dry beans in Parana State, Brazil
Provedor de dados: 63
Autores: Faria,R.T. de; Folegatti,M.V.; Frizzone,J.A.; Saad,A.M.
The economical benefits of different irrigation strategies were assessed by long term simulation (20 years) for dry beans in Paraná, Brazil. The model BEANGRO was used to simulate crop yield and irrigation requirements assuming eight levels of irrigation threshold (20 to 90% of the remaining soil available water in steps of 10%), in addition to a level considering no irrigation. Net return was the objective function to select the optimum irrigation management strategy, assuming fixed and stochastic distributions of historical product price. The results showed that yield was significantly increased by irrigation despite a high variability for all the simulation strategies, due to variations on growth conditions over the years. Although the net return was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Irrigation; Modeling; Economical analysis.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161997000300018

Agrometeorological models for 'Valencia' and 'Hamlin' sweet oranges to estimate the number of fruits per plant
Provedor de dados: 63
Autores: Paulino,Silvia Elisandra Pasqua; Mourão Filho,Francisco de Assis Alves; Maia,Aline de Holanda Nunes; Avilés,Tatiana Eugenia Cantuarias; Dourado Neto,Durval.
The development of models that allow forecasting yield tendencies is important to all sectors of the citrus industry. This work evaluated the influence of meteorological variables in different phases of the crop cycle in order to propose empirical models to estimate the number of fruits per plant (NFP) of 'Valencia' and 'Hamlin' sweet oranges. NFP sampling data from the citrus juice industry of the State of São Paulo, on the total of 15 harvests (1990/91 to 2004/05), classified into three age classes, and meteorological data of maximum and minimum air temperature and rainfall of Limeira, SP, Brazil, were utilized. Correlation coefficients were initially computed between the number of fruits per plant and each meteorological variable used for water balance...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus; Harvest; Modeling; Yield.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162007000100001

Calibration and validation of models for short-term decomposition and N mineralization of plant residues in the tropics
Provedor de dados: 63
Autores: Nascimento,Alexandre Ferreira do; Mendonça,Eduardo de Sá; Leite,Luiz Fernando Carvalho; Scholberg,Johannes; Neves,Julio Cesar Lima.
Insight of nutrient release patterns associated with the decomposition of plant residues is important for their effective use as a green manure in food production systems. Thus, this study aimed to evaluate the ability of the Century, APSIM and NDICEA simulation models for predicting the decomposition and N mineralization of crop residues in the tropical Atlantic forest biome, Brazil. The simulation models were calibrated based on actual decomposition and N mineralization rates of three types of crop residues with different chemical and biochemical composition. The models were also validated for different pedo-climatic conditions and crop residues conditions. In general, the accuracy of decomposition and N mineralization improved after calibration. Overall...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Nutrient cycling; Organic agriculture; Soil organic matter.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162012000600008

Probabilistic tools for assessment of pest resistance risk associated to insecticidal transgenic crops
Provedor de dados: 63
Autores: Maia,Aline de Holanda Nunes; Dourado Neto,Durval.
One of the main risks associated to transgenic crops expressing Bacillus thuringiensis (Bt) toxins is the evolution of pest resistance. The adoption of Bt crops requires environmental risk assessment that includes resistance risk estimation, useful for definition of resistance management strategies aiming to delay resistance evolution. In this context, resistance risk is defined as the probability of the Bt toxin resistance allele frequency (RFreq) exceeding a critical value (CriticalFreq). Mathematical simulation models have been used to estimate (RFreq) over pest generations. In 1998, Caprio developed a deterministic simulation model with few parameters that can be used to obtain RFreq point estimates from point information about model parameters and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacillus thuringiensis; Bt crops; Modeling; Uncertainty analysis.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000500003

Simulation model for particle dynamics in rumen of cattle fed sugarcane diet
Provedor de dados: 63
Autores: Collao-Saenz,Edgar Alain; Dijkstra,Jan; Paiva,Paulo César de Aguiar; Bannink,André; Arcuri,Pedro Braga; Teixeira,Júlio César; Olalquiaga Pérez,Juan Ramón; David,Flávia Maria.
Animal simulation models are sets of equations used to describe biological processes. A non-steady state simulation model of cattle digestion is presented in order to represent nutrient availability as a response to feed intake pattern and the kinetics of particle size reduction. Variables representing the particle size reduction and discontinuous voluntary feed intake were included in a mechanistic model created to optimize the supplementation of sugarcane based diets. In general the predicted values were very close to observed values for fibre and nitrogen flows. The model has not shown consistent bias in relation to the behavior of the observed data of duodenal flow of neutral detergent fiber and non-ammonia nitrogen. Milk production simulations were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dairy cows; Milk production; Modeling; Rumen.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000200002

Predicting the distribution of forest tree species using topographic variables and vegetation index in eastern Acre, Brazil
Provedor de dados: 36
Autores: FIGUEIREDO,Symone Maria de Melo; VENTICINQUE,Eduardo Martins; FIGUEIREDO,Evandro Orfanó; FERREIRA,Evandro José Linhares.
Species distribution modeling has relevant implications for the studies of biodiversity, decision making about conservation and knowledge about ecological requirements of the species. The aim of this study was to evaluate if the use of forest inventories can improve the estimation of occurrence probability, identify the limits of the potential distribution and habitat preference of a group of timber tree species. The environmental predictor variables were: elevation, slope, aspect, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). To estimate the distribution of species we used the maximum entropy method (Maxent). In comparison with a random distribution, using topographic variables and vegetation index as...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Maxent; Forest inventory; Modeflora; Amazon.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672015000200167

Paleodistribution of Neotropical species of Erythroxylum (Erythroxylaceae) in humid and dry environments
Provedor de dados: 39
Autores: Cordeiro,Luciana Silva; Araújo,Francisca Soares de; Koch,Ingrid; Simões,André Olmos; Martins,Fernando Roberto; Loiola,Maria Iracema Bezerra.
ABSTRACT Variation in environmental conditions during the Quaternary period served as important filters for the maintenance of vegetation types and for determining the composition of the current biota. We analyzed oscillations in the distributions of different vegetation types in Brazil during the Quaternary period using species of the genus Erythroxylum (Erythroxylaceae) because of the vast heterogeneity of habitats in which they occur. We hypothesized that it would be possible to observe geographically distinct distribution patterns of species of Erythroxylum as a result of the climate changes that occurred during the last glacial maximum (LGM) and in the last interglacial period (LIG) of the Pleistocene. We used bioclimatic variables to elaborate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazil; Modeling; Paleoclimates; Vegetation; Pleistocene.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062017000400645

Simulação do crescimento do capim Tanzânia irrigado com base na unidade fototérmica, na adubação nitrogenada e na disponibilidade hídrica do período - doi: 10.4025/actasciagron.v33i2.4901
Provedor de dados: 1
Autores: Almeida, Alexsandro Claudio dos Santos; UNIVERSIDADE DE SÃO PAULO; Mingoti, Rafael; USP; Coelho, Rubens Duarte; USP; Lourenço, Leandro Fellet; USP.
A modelagem da produção de forragem com o uso de unidades fototérmicas (UF) foi utilizada com sucesso nos capins elefante cv. Napier, Tanzânia e Brachiaria em condições ótimas de adubação e disponibilidade hídrica. Havendo a necessidade de modelos de produção de forragens para diferentes níveis de adubação e de irrigação. Nesse sentido, o objetivo deste trabalho é propor modelos para o capim Tanzânia (Panicum maximum Jacq. cv Tanzânia) sob diferentes lâminas de irrigação (25, 50,75, 100 e 125% da ETc) e adubação nitrogenada em diferentes localidades do Brasil, a partir de unidades fototérmicas. Os modelos foram ajustados para as doses de 0, 30, 60, 110 e 270 kg de N ha-1, doses divididas em aplicações após cada corte, com um ciclo de 35 dias de descanso....
Tipo: Pesquisa em ambiente controlado
Palavras-chave: Agronomia; Engenharia rural; Irrigação e Drenagem Otimização; Modelagem; Irrigação irrigação e drenagem Optimization; Modeling; Irrigation.
Ano: 2011
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/4901

Estimating soybean yields with artificial neural networks
Provedor de dados: 1
Autores: Alves, Guiliano Rangel; Teixeira, Itamar Rosa; Melo, Francisco Ramos; Souza, Raniele Tadeu Guimarães; Silva, Alessandro Guerra.
 The complexity of the statistical models used to estimate the productivity of many crops, including soybeans, restricts the use of this practice, but an alternative is the use of artificial neural networks (ANNs). This study aimed to estimate soybean productivity based on growth habit, sowing density and agronomic characteristics using an ANN multilayer perceptron (MLP). Agronomic data from experiments conducted during the 2013/2014 soybean harvest in Anápolis, Goiás State, B razil, were used to conduct this study after being normalized to an ANN-compatible range. Then, several ANNs were trained to choose the best-performing one. After training the network, a performance analysis was conducted to select the ANN with a performance most appropriate for the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agronomia; Biometria  modelagem e estatística Glycine max (L.) Merrill; Agronomic characteristics; Modeling; MLP; Perceptron. Produção vegetal.
Ano: 2018
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/35250

Estimating soybean yields with artificial neural networks
Provedor de dados: 1
Autores: Alves, Guiliano Rangel; Teixeira, Itamar Rosa; Melo, Francisco Ramos; Souza, Raniele Tadeu Guimarães; Silva, Alessandro Guerra.
 The complexity of the statistical models used to estimate the productivity of many crops, including soybeans, restricts the use of this practice, but an alternative is the use of artificial neural networks (ANNs). This study aimed to estimate soybean productivity based on growth habit, sowing density and agronomic characteristics using an ANN multilayer perceptron (MLP). Agronomic data from experiments conducted during the 2013/2014 soybean harvest in Anápolis, Goiás State, B razil, were used to conduct this study after being normalized to an ANN-compatible range. Then, several ANNs were trained to choose the best-performing one. After training the network, a performance analysis was conducted to select the ANN with a performance most appropriate for the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max (L.) Merrill; Agronomic characteristics; Modeling; MLP; Perceptron.; Produção vegetal.
Ano: 2018
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/35250

Leaf area estimate of Pennisetum glaucum by linear dimensions
Provedor de dados: 2
Autores: Leite, Mauricio Luiz de Mello Vieira; Lucena, Leandro Ricardo Rodrigues de; Cruz, Manoela Gomes da; Sá Júnior, Eduardo Henrique de; Simões, Vicente José Laamon Pinto.
Leaf area measurements are of the main parameters used in agronomic studies to evaluate plant growth. The current study used a non-destructive method based on linear leaf dimensions (length and width) to select the regression model to estimate millet (Pennisetum glaucum) leaf area. For two millet genotype (IPA BULK 1 BF and ADR 300) 128 randomly-chosen leaves were measured at different vegetative growth stages. Measures of length and width of each leaf were made using digital calipers. Leaf area was measured using a gravimetric method. The best-fit leaf area estimation model was selected via linear, potential and gamma regression models. Leaf area values varied from 3.02 to 209.21 cm2. The average value was 95.31 cm2. The potential regression model...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf blade; Millet; Modeling; Non-destructive method.
Ano: 2019
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/42808

Leaf area estimation for Psychotria carthagenensis and Psychotria hoffmannseggiana as a function of linear leaf dimensions
Provedor de dados: 3
Autores: Ribeiro, João Everthon da Silva; Coêlho, Ester dos Santos; Figueiredo, Francisco Romário Andrade; Pereira, Walter Esfrain; Albuquerque, Manoel Bandeira de.
Determining leaf area is important for studies involving plant growth and development. The aim of the present study was to obtain models for estimating leaf area of Psychotria carthagenensis and Psychotria hoffmannseggiana using linear measurements of leaf blades (length and width). Two hundred leaf blades of each species were collected in Parque Estadual Mata do Pau-Ferro in the municipality of Areia, Paraíba, Northeast Brazil. The equations evaluated for producing potential models included the following: linear, quadratic, potential and exponential. The criteria used to determine the best model(s) were as follows: high coefficient of determination (R²), low root-mean-square error (RMSE), low Akaike information criterion (AIC), high Willmott concordance...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biologia biometry; Non-destructive method; Modeling; Rubiaceae. Ecologia.
Ano: 2019
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/43494

Neural Network Model for Land Cover Classification from Satellite Images
Provedor de dados: 113
Autores: Bocco,Mónica; Ovando,Gustavo; Sayago,Silvina; Willington,Enrique.
Land cover data represent environmental information for a variety of scientific and policy applications, so its classification from satellite images is important. Since neural networks (NN) do not require a hypothesis about data distribution, they are valuable tools to classify satellite images. The objectives of this work were to develop NN models to classify land cover data from information from satellite images and to evaluate them when different input variables are used. MODIS-MYD13Q1 satellite images and data of 85 plots in Córdoba, Argentina, were used. Five NN models of multi-layer feed-forward perceptron were designed. Four of these received NDVI (Normalized Difference Vegetation Index), EVI (Enhanced Vegetation Index), red (RED) and near infrared...
Tipo: Journal article
Palavras-chave: Modeling; Back-propagation neural networks; Remote sensing; Crops-bare soil.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-28072007000400009

Development and Performance Evaluation of Screw-like Fish Meal Pelletizer
Provedor de dados: 111
Autores: Ikubanni, Peter Pelumi; Agboola, Olayinka Oluwole; Ogunsemi, Bamidele Tope.
Aquaculture farming requires good and balanced meal for the fish to stay healthy. Several fish meal pelletizing machines have been designed and developed in Nigeria. This study is to contribute to the improvement of existing design models through designing, fabricating and performing evaluation tests on the machine. The average discharge efficiency, percentage loss due to residue ingredients and production rate for the machine under study after four runs for 5 kg fish meal ingredients weight was processed for 2.5 minutes was 92.25 %, 7.75 % and 110.7 kg/hr, respectively. It was discovered that as the drying days increase, the percentage moisture content removal increases for the two categories of pelletized fish meal weight (4.6 kg and 4.65 kg) considered...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Development; Fish meal; Mechanical engineering; Modeling; Pelletize; Aquaculture; Nigeria.
Ano: 2019
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/5371

Effect of drying temperatures and pre-treatments on drying characteristics, energy consumption, and quality of bell pepper
Provedor de dados: 111
Autores: Tunde-Akintunde, Toyosi; Oyelade, Olusegun; Akintunde, Babatunde.
Abstract: The effect of air temperature (50°C, 60°C, 70°C, 80°C and 90°C) and pre-treatments (steam, water palm oil-water, groundnut oil-water blanching) on the drying characteristics and quality of bell pepper was investigated.  The results were fitted to six thin-layer drying models and Parabolic model gave the best fit.  The pretreated samples dried faster than untreated samples and had lower values of total energy needed and specific energy requirement.  The ascorbic acid content, color and rehydration index varied from 129.1 to 316.8 mg/100 g dry matter, 0.1 to 0.9, 22 to 33 mL and pretreated dried pepper generally had higher values than untreated samples.   Keywords: modeling, energy consumption, Rehydration index, color, pepper
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Energy consumption; Rehydration index; Color; Pepper.
Ano: 2014
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2741

Measuring some physical properties of sunflower (helianthus annus l.) head and modeling dimensions
Provedor de dados: 111
Autores: Mirzabe, Amir Hossein; Khazaei, Javad; Chegini, Gholam Reza.
For 100 sunflower head, maximum and minimum diameters, thickness, height of the ground, and mass of all seeds on sunflower head (SH) for five conventional varieties were measured.  To examine the correlation between maximum SH diameter and minimum SH diameter, SH thickness, SH height from the ground and SH seeds mass, linear regression method was used.  Also SH diameter and SH thickness of four sunflower hybrids varieties were measured.  Log-normal, Weibull and Generalized extreme value (G.E.V) distribution were used in order to model SH diameter and SH thickness distributions of all varieties and hybrids; also, Kolmogorov-Smirnov methods were used for comparison of all probability density.  Results indicated that value of average of dimensions, geometric...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Thresher machine; Image processing technique; Modeling; Generalized extreme value; Log-normal; Wiebull.
Ano: 2016
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3641

Predictive Models for Head Rice Yield and Breakage Ratio Under Optimal  Steam Parboiling Variables for Faro 44 Rice Variety
Provedor de dados: 111
Autores: Nwajinka, Charles Obiora; Muochebe, Bonaventure; Nwatu, Ernest Ifeanyichukwu.
This study was carried out to determine the optimal conditions for steam parboiling process for increased Head Rice Yield (HRY) and reduced Breakage Ratio (BR)of milled FARO-44 rice variety. The process variables studied were  Soaking Temperature (SkT), soaking time (Skt) and Steaming time (STt). The SkT was varied between 70 oC and 90 oC, Skt between 40 and 50 mins while STt was varied between 8 to 12hrs. Head Rice Yield (HRY) and Breakage Ratio(BR) were selected as the quality attributs considered in the optimization as the response variables. The objective of the optimization was to determine the combination of factors that will maximize HRY and minimize BR. At the composite desirability of 0.683, the optimal values of STt, STt and Skt were 76.99...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: FARO-44; Rice; Head rice; Breakage ratio; Parboiling; Modeling.
Ano: 2022
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/6881

Moisture content on some engineering properties of celery (Apium Graveolens L) seeds
Provedor de dados: 111
Autores: Mirzabe, Amir Hossein; Taheri, Mojtaba; Pouyesh, Alireza; Bahrami Bavani, Neda.
The study was conducted to investigate some physical properties of celery seed at various moisture levels.  The average length, width, thickness and 1000-seeds mass were 0.571, 0.429, 0.295 mm and 0.792 g, respectively, at moisture content of 5.24% (d.b).  Length, width and thickness distributions of the seeds were modeled using Generalized Extreme Value, lognormal and Weibull distributions.  Results showed that to model length of the seeds, lognormal distribution had the best performance while to model the width of the seeds Weibull distribution had the best performance.  True density has increase from 892.02 to 931.42 kg/m3 when the moisture content increased from 5.24% to 20.25% (d.b).  The angle of static friction increased from 28.45 to 39.66°, 25.15...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Image processing technique; Dimensional properties; Modeling; Gravimetrical properties; Medicinal plant.
Ano: 2016
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3559

Thermodynamic properties and moisture sorption isotherms of Matricaria pubescens from Algerian Sahara
Provedor de dados: 111
Autores: saad, amel; Touati, Boumediene; Seghir, Abdelhadi; Abdenebi, Asma.
Experimental adsorption and desorption behavior of Matricaria pubescens was determined by using the gravimetric static method at 30, 40 and 50 °C, for water activity ranging from 0.057 to 0.898. Experimental data were compared with eight widely recommended sorption models (Caurie, BET, Henderson-Thomson, Smith, Halsey, Oswin, Peleg, and Adam and Shove) in literature. Peleg and Halsey models were found to be the most suitable for describing sorption isotherm curves. The net isosteric heats of sorption were also calculated by using the Clausius-Clapeyron equation.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Matricaria .p; Sorption isotherm; Modeling; Isosteric heat of sorption.
Ano: 2022
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/7089

Application of the Response Surface Method in the Analysis of Ohmic Heating Process Performance in Sour Orange Juice Processing
Provedor de dados: 111
Autores: Azadbakht, Mohsen; Vahedi Torshizi, Mohammad; Kashaninejad, Mahdi.
Three voltage gradients (8.38, 10.83, and 13.33 V cm-1) and three weight loss percentages (10, 20, and 30 percent) were examined; also the system performance coefficient, input current, heating process duration, power consumption and electrical conductivity investigated. The response surface method was also used for modeling s and optimization. For the response surface method, weight loss percentage and voltage gradient were selected as independent variables; and factors  system performance coefficient, heating process duration, input current, power consumption and electrical conductivity were selected as responses. According to results, all obtained models were significant for responses factors, but the voltage gradient and weight loss percentage were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sour orange juice; Ohmic method; Response surface method; Modeling.
Ano: 2020
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/6057

Foam-mat drying of shrimp: characterization and drying kinetics of foam
Provedor de dados: 111
Autores: Azizpour, Mehran; Mohebbi, Mohebbat; Khodaparast, Mohammad Hossein Haddad; Varidi, Mehdi.
The effects of water: shrimp ratio and xanthan gum (XG) concentration on characteristics of shrimp foam were investigated.  Foams were prepared from shrimp puree by adding several xanthan gum concentrations (0.1, 0.2, 0.3 % w/w), water: shrimp ratios (2:1, 3.5:1, 5:1 w/w) and whipped for five minutes.  Incorporation of 0.2% w/w XG with 3.5:1 w/w water: shrimp ratio was selected because of having better characteristics of produced foams and then dried at 50, 60 and 70°C.  Results showed that stability and density of foam increased with increasing xanthan gum concentration.  However, increasing water : shrimp ratio caused to decrease in stability and density of foam.  As the temperature increased from 50 to 70°C, the drying time decreased to 55 minutes....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Activation energy; Effective diffusivity; Foam-mat drying; Foam characteristics; Modeling; Shrimp.
Ano: 2013
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2339

Investigating of drying kinetics and mathematical modeling  of turnip
Provedor de dados: 111
Autores: Gharehbeglou, Pouria; Askari, Bijan; Homayouni Rad, Aziz; Hoseini, Seyed Sajjad; Tavakoili Pour, Hamid; Elhami Rad, Amir Hosein.
The drying process of turnip and drying rate curves were investigated at different temperatures (55, 70 and 85°C) with air flow rate of 1.5 m/s.  Also effective diffusion coefficient and activation energy were calculated by using Arrhenius equation and Fick’s second law for infinite slab.  The effective diffusivity varied between 5.471×10-10 and 8.966×10-10 in the range of (55°C to 85°C).  The value of activation energy was found to be 16.013 kJ/mol.  The mathematical models (Newton, Page, Modified Page, Henderson and Pabis, Logarithmic, Two term, Two term exponential, Wang and Singh, Simplified Fick’s diffusion, Modified Page –II, Verma, Midilli–Kucuk, Hii, Law and Cloke, Approximation of diffusion, Modified Henderson and Pabis) were fitted to the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Turnip; Hot air convective drying; Modeling; Drying rate; Effective diffusivity; Activation energy.
Ano: 2014
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2864

MODELING THE MICROWAVE DRYING CHARACTERISTICS OF CARROT SLICES
Provedor de dados: 111
Autores: Nwajinka, Charles Obiora; Okonjo, Emmanuel.
A study of the effects of Microwave drying of carrot slices was carried out. The samples were dried from moisture content of 70.71 to 10.7% (wb). Empirical models were developed for predicting the drying kinetics of the Carrot slices at different microwave powers and slice thicknesses. The drying curves were graphically used to present the relationships between moisture ratio and time of drying. The following fit parameters were obtained using Henderson and Pabis model: coefficient of determination (R²) from 0.8729 to 0.9531, error sum of squares (SSE) ranging from 0.0212 to 0.07875, and root mean square error (RMSE) from 0.05504 to 0.08461.  Fourier model gave a better fit with the following parameters: coefficient of determination (R²) from 0.9991 to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agricultural and Bioresource Engineering; Food and bioprocess Engineerin Carrot; Microwave; Modeling; Drying Characteristics; Moisture Diffusivity.
Ano: 2019
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/5488

Drying characteristics and energy requirement of drying cowpea leaves and jute mallow vegetables
Provedor de dados: 111
Autores: Mutuli, Gibson Peter; Mbuge, Duncan.
Thin layer drying of cowpea leaves (Vigna unguiculata) and jute mallow (Corchurus olitorious L) (African leafy vegetables) was studied at different temperatures (40oC -100oC) in a convective laboratory dryer. The study determined the drying characteristics of the vegetables, the maximum drying temperature and the drying energy requirements. Moisture content of the African leafy vegetables was determined on dry basis and the data were used to calculate moisture ratios and drying curves were plotted. The drying occurred in the falling rate period. The experimental data were fitted to fourteen thin layer drying models and the most appropriate drying model determined using correlation coefficient, mean square error and standard error of estimate. The model...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Africa leafy vegetables; Thin layer drying; Moisture content; Energy; Modeling.
Ano: 2015
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3368

Mimicking Indoor Climate Dynamics and Ammonia Emissions in a Pig Housing Compartment Using Artificial Pigs and an Automatic Urea Spraying Installation
Provedor de dados: 111
Autores: Tabase, Raphael Kubeba.
The study aims to develop a test platform (TP) compartment that could mimic diurnal variations in indoor climate and NH3 emission in a real pig compartment and to compare diurnal indoor climate and NH3 production between two TP compartments and a real compartment. The objectives were achieved by using a real and TP compartment followed by an ad hoc test that used two TP compartments and another real compartment. The TP had two compartments equipped with mock-up pigs as heat source and automatic urea solution spraying installation to mimic pig urination at the pen floor. The study evaluated indoor climate and NH3 production in a 4-day comparative test between a TP and a real compartment followed by a 3-day comparative test between two TP compartments and a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonia; Emission; Modeling; Pig housing; Test platform; Ventilation; Belgium.
Ano: 2019
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/5216

Determination of equilibrium isotherms and proper mathematical model for lime slices
Provedor de dados: 111
Autores: taghipour, mehdi; baratikakolaki, masoud; zomorodian, ali; nasiri, mehdi.
Equilibrium moisture content (EMC) at different air relative humidity and temperatures is a vital parameter in optimization of drying and storage processes. In the present study amount of moisture content in lime (Local variety) slice at different ambient temperatures of 30°C, 40°C and 50°C were measured using gravimetric method. The obtained E.M.C experimental values were employed to plot the isotherm curve at different environmental air temperatures. These data also were fed to fourteen popular mathematical models. The well-known statistical factors such as Coefficient of determination (R^2), Chi-square (χ2), Root of mean square error (RMSE) and Mean of relative deviation (MRD) were calculated to validate the goodness of fit. The Peleg Model was selected...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biosystem engineering lime slice; Equilibrium moisture content; Modeling; Monolayer.
Ano: 2016
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3456

Determining dimensional, gravimetrical and frictional properties of red radish seeds (Raphanus Sativus L.) as a function of moisture content
Provedor de dados: 111
Autores: Mirzabe, Amir Hossein; Taheri, Mojtaba; Asaei, Habil; Kianmehr, Mohammad Hossein.
To design the planting, separating, threshing, sizing and packing machines for agricultural products, physical and mechanical properties of the products should be known. In this paper, some physical properties of red radish seeds were studied. Dimensional parameters, when moisture content equals to 5.65% based on dry bases (d.b), were measured using image processing technique. Effects of moisture content on gravimetrical and frictional properties of the seeds, including mass of single seed, 1000-unit seed, bulk density, true density, porosity, static coefficient of friction on various surfaces, and angle of repose based on pouring, Hele-Shaw, empting and filling methods were studied. Effects of volume of the container (150, 350, 550 and 750 mL) and height...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Image processing technique; Dimensional properties; Modeling; Moisture content; Gravimetrical properties; Frictional properties.
Ano: 2015
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3406

Modeling and optimization of drying process of paddy in infrared and warm air fluidized bed dryer
Provedor de dados: 111
Autores: pourbagher, roghayeh; rohani, abbas; rahmati, Mohammad Hashem; Abbaspour-Fard, Mohammad Hossein.
This paper investigated the effect of the components of fluidized bed dryer with two thermal sources of heater and infrared such as air temperature at three levels (40, 50 and 60°C) equivalent to radiation intensity of 0.031, 0.042 and 0.053 W.cm-3 in infrared dryer, final moisture content of dried Tarom and Shirudi varieties at three levels (8-9%, 9-10% and 10-11% (d.b.)) and air velocity of 4.5 ms-1 on the milling characteristic and drying time. To this end, stepwise regression was used for selecting the best models for each dependent variable in terms of the independent variables and genetic algorithm was used for optimizing the parameters of dryer with simultaneous consideration of cracked and fractured grains, milling recovery, degree of milling and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Optimization; Infrared; Milling characteristic; Paddy.
Ano: 2018
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4666

Sensitivity analysis of the AquaCrop model for maize crop in Southern Brazil
Provedor de dados: 111
Autores: Moretti de Souza, Jorge Luiz; de Oliveira, Cibelle Tamiris; Kreutz Rosa, Stefanie Lais; Yoiti Tsukahara, Rodrigo.
Crop growth models are abstract tools that represent a real system, being a simple and important technology to develop studies aiming to improve the yields of the most agricultural crops, like the maize in Brazil. The objective of this study was to analyze the sensitivity of the main AquaCrop model input parameters, as well as their responses in maize yield estimation, in Parana State, Southern Brazil. The analyses were performed with the genotype 30R50YH, 2014/15 harvest, planted on April 11, 2014. The parameters analyzed refer to crop, soil and soil management. The parameters were modified individually, maintaining the others fixed. With the results, the Sensitivity Index (SI) was calculated, which allowed the identification of the most sensitive...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Mathematical models; Sensitivity analysis; Maize; Zea mays.
Ano: 2022
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/7541

Influence of mass transfer on bubble plume hydrodynamics
Provedor de dados: 42
Autores: LIMA NETO,IRAN E.; PARENTE,PRISCILA A.B.
ABSTRACT This paper presents an integral model to evaluate the impact of gas transfer on the hydrodynamics of bubble plumes. The model is based on the Gaussian type self-similarity and functional relationships for the entrainment coefficient and factor of momentum amplification due to turbulence. The impact of mass transfer on bubble plume hydrodynamics is investigated considering different bubble sizes, gas flow rates and water depths. The results revealed a relevant impact when fine bubbles are considered, even for moderate water depths. Additionally, model simulations indicate that for weak bubble plumes (i.e., with relatively low flow rates and large depths and slip velocities), both dissolution and turbulence can affect plume hydrodynamics, which...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aeration; Bubbles; Hydrodynamics; Mass transfer; Modeling; Oxygenation.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000100411

Short and long period optimization of drug doses in the treatment of AIDS
Provedor de dados: 42
Autores: CAETANO,MARCO A. L.; YONEYAMA,TAKASHI.
Numerical optimization techniques are useful in solving problems of computing the best inputs for systems described by mathematical models and when the objectives can be stated in a quantitative form. This work concerns the problem of optimizing the drug doses in the treatment of AIDS in terms of achieving a balance between the therapeutic response and the side effects. A mathematical model describing the dynamics of HIV viruses and CD4 cells is used to compute the short term optimal drug doses in the treatments of patients with AIDS by a direct method of optimization using a cost function of Bolza type. The model parameters were fitted to actual published clinical data. In order to simplify the numerical procedures, the control law is expressed as a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Simulation; Drugs; Treatment; AIDS.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652002000300002

Modeling radiative transfer in tropical rainforest canopies: sensitivity of simulated albedo to canopy architectural and optical parameters
Provedor de dados: 42
Autores: Yanagi,Sílvia N. M.; Costa,Marcos H.
This study evaluates the sensitivity of the surface albedo simulated by the Integrated Biosphere Simulator (IBIS) to a set of Amazonian tropical rainforest canopy architectural and optical parameters. The parameters tested in this study are the orientation and reflectance of the leaves of upper and lower canopies in the visible (VIS) and near-infrared (NIR) spectral bands. The results are evaluated against albedo measurements taken above the K34 site at the INPA (Instituto Nacional de Pesquisas da Amazônia) Cuieiras Biological Reserve. The sensitivity analysis indicates a strong response to the upper canopy leaves orientation (x up) and to the reflectivity in the near-infrared spectral band (rNIR,up), a smaller sensitivity to the reflectivity in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amazonian Tropical Forest; Albedo; Radiative transfer; Modeling.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000400010

Relevance of Hydrodynamic Effects for the Calculation of Outer Surface Potential of Biological Membrane Using Electrophoretic Data
Provedor de dados: 42
Autores: SILVA JUNIOR,IZAN M.; CASTRO,MARIA CLÍCIA S.; SILVA,DILSON; CORTEZ,CÉLIA M.
ABSTRACT In this paper, we present the results of a study on the influence of hydrodynamic effects on the surface potentials of the erythrocyte membrane, comparing two different models formulated to simulate the electrophoretic movement of a biological cell: the classical Helmholtz-Smoluchowski model and a model presented by Hsu et al. (1996). This model considers hydrodynamic effects to describe the distribution of the fluid velocity. The electric potential equation was obtained from the non-linear Poisson-Boltzmann equation, considering the spatial distribution of electrical charges fixed in glycocalyx and cytoplasmic proteins, as well as electrolyte charges and ones fixed on the surfaces of lipidic bilayer. Our results show that the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Electric potential profile; Erythrocyte membrane; Electrophoretic mobility; Glycocalyx; Hydrodynamic effects.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000300751

Predicting the distribution of Omalonyx (Mollusca: Pulmonata: Succineidae) species from literature review, museum databases and new sampling efforts in Brazil
Provedor de dados: 49
Autores: Coscarelli,Daniel; Montresor,Lângia C.; Russo,Philip; Melo,Alan Lane de; Vidigal,Teofânia H.D.A.
Abstract Accurate distributional information is crucial for studies on systematics, biodiversity and conservation. To improve the knowledge regarding the geographical distribution of Omalonyx in South America, we present updated information based on data from a literature review, institutional collections and malacological surveys. All this information composed the dataset used to predict species distribution employing the Maximum Entropy Algorithm (MaxEnt). The model was run using data on species distribution, altitude and bioclimatic variables (WorldClim database). The model had consistent performance, and areas presenting similar conditions to areas where the species were recorded were considered areas of occurrence. The predicted occurrence areas...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MaxEnt; Niche model; Species distribution; Modeling; Succineids; Neotropic.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032018000100209

Estimation of leaf area in coffee leaves (Coffea arabica L.) of the Castillo® variety
Provedor de dados: 53
Autores: Unigarro-Muñoz,Carlos Andrés; Hernández-Arredondo,Juan David; Montoya-Restrepo,Esther Cecilia; Medina-Rivera,Ruben Darío; Ibarra-Ruales,Lizardo Norbey; Carmona-González,Claudia Yoana; Flórez-Ramos,Claudia Patricia.
Allometric models based on measurements of single leaf dimensions or a combination there are useful tools for determining individual leaf area (LA) because they are non-destructive, precise, simple and economical methods. The present study was carried out at the Central Station Naranjal of Cenicafé, located in the Department of Caldas (Colombia), four models were defined using the variables length (L) and/or width (W) to estimate LA in coffee leaves of the Castillo® variety (Coffea arabica L.). Estimation of regression coefficients was performed using information recorded from 6,441 leaves (group 1), and their validation was performed using records from another 992 leaves (group 2). Leaves were collected from all strata of the canopy and ranged from 0.76...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Length; Width.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052015000400412

Models for leaf area estimation in dwarf pigeon pea by leaf dimensions
Provedor de dados: 53
Autores: Pezzini,Rafael Vieira; Cargnelutti Filho,Alberto; Alves,Bruna Mendonça; Follmann,Diego Nicolau; Kleinpaul,Jéssica Andiara; Wartha,Cleiton Antonio; Silveira,Daniela Lixinski.
ABSTRACT This study aims to determine the most suitable model to estimate the leaf area of dwarf pigeon pea in function of the leaf central leaflet dimension. Six samplings of 200 leaves were performed in the first experiment, at 36, 42, 50, 56, 64, and 72 days after emergence (DAE). In the second experiment, seven samplings of 200 leaves were performed at 29, 36, 43, 49, 57, 65, and 70 DAE, totaling 2600 leaves. The length (L) and width (W) of the central leaflet were measured in all leaves composed by left, central, and right leaflets, the product of length times width (LW) was calculated, and the leaf area (Y – sum of left, central, and right leaflet areas) was determined by digital images. Linear, power, quadratic, and cubic models of Y as function of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cajanus cajan (L.) Millsp; Modeling; Non-destructive method.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000200221

Agronomic performance of white oats cultivated under fertigation with treated sewage effluent and definition of critical limits of Normalized Difference Vegetation Index
Provedor de dados: 53
Autores: Coelho,Anderson Prates; Faria,Rogério Teixeira de; Barbosa,Aline Michelle da Silva; Dalri,Alexandre Barcellos; Rosalen,David Luciano.
ABSTRACT One of the benefits of irrigation with wastewater in agriculture is the reduction in the use of mineral fertilizers and the increase in crop yield. For wastewater application, the use of remote sensing can help to define specific management areas. The aim of this study was to evaluate the yield and the growth of irrigated white oats (Avena sativa L.) with varying treated sewage effluent (TSE) levels. These attributes were then correlated with Normalized Difference Vegetation Index (NDVI) values obtained at four phenological stages of the crop and used to define critical limits of NDVI. The experiment consisted of five TSE treatments differing in irrigation depths (11, 31, 60, 87, and 100%). Mean NDVI values in the crop were determined with an...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Avena sativa L.; Biomass; Modeling; NDVI; Remote sensing.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052019000400553

Utilization of the cropgro-soybean model to estimate yield loss caused by Asian rust in cultivars with different cycle
Provedor de dados: 53
Autores: Rodrigues,Rafael de Ávila; Pedrini,João Eduardo; Fraisse,Clyde William; Fernandes,José Maurício Cunha; Justino,Flávio Barbosa; Heinemann,Alexandre Bryan; Costa,Luiz Cláudio; Vale,Francisco Xavier Ribeiro do.
In recent years, crop models have increasingly been used to simulate agricultural features. The DSSAT (Decision Support System for Agrotechnology Transfer) is an important tool in modeling growth; however, one of its limitations is related to the unaccounted-for effect of diseases. Therefore, the goals of this study were to calibrate and validate the CSM CROPGRO-Soybean for the soybean cultivars M-SOY 6101 and MG/BR 46 (Conquista), analyze the performance and the effect of Asian soybean rust on these cultivars under the environmental conditions of Viçosa, Minas Gerais, Brazil. The experimental data for the evaluation, testing, and adjustment of the genetic coefficients for the cultivars, M-SOY 6101 and MG/BR 46 (Conquista), were obtained during the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: DSSAT; Calibration; Validation; Modeling; Rust epidemics.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000200021

Extension of the IsaViz software for the representation of metabolic and regulatory networks
Provedor de dados: 52
Autores: Veiga,Diogo Fernando; Cecconello,Pedro de Stege; Lucca,José Eduardo de; Porto,Luismar Marques.
In this work we developed an extension of IsaViz software, a RDF (Resource Description Framework) authoring tool, designed to be a graphical environment to build models of metabolic and regulatory networks. This environment, called Metabolic IsaViz, was linked to a genomic library of types and was modeled on the basis of ontologies. Biochemical pathways included data at sequence level (e.g., the amino acid sequence of enzymes), besides kinetic and thermodynamic parameters for the reactions. Models created with Metabolic IsaViz could be exported to pathways simulators through SBML (Systems Biology Markup Language), which allowed to analyze the pathway dynamics of target chemicals.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Metabolic and Regulatory Pathways; RDF/XML; Modeling.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000400025

Enhanced lipase recovery through RSM integrated differential evolutionary approach from the fermented biomass
Provedor de dados: 52
Autores: Garlapati,Vijay Kumar; Vundavilli,Pandu Ranga; Banerjee,Rintu.
The aim of this work was to apply a modeling integrated optimisation approach for a complex, highly nonlinear system for an extracellular lipase extraction process. The model was developed using mutation, crossover and selection variables of Differential Evolution (DE) based on central composite design of Response Surface Methodology. The experimentally validated model was optimized by DE, a robust evolutionary optimization tool. A maximum lipase activity of 134.13 U/gds (more than 36.28 U/gds compared to one variable at a time approach) was observed with the DE-stated optimum values of 25.01% dimethyl sulfoxide concentration, 40 mM buffer, 128.52 min soaking time and 35ºC with the DE control parameters, namely number of population, generations, crossover...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Optimization; Lipase extraction; Response surface methodology; Differential evolution; Solid state fermentation.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000500001

Mathematical modeling of convective air drying of quinoa-supplemented feed for laboratory rats
Provedor de dados: 52
Autores: Vega-Gálvez,Antonio; Dagnino-Subiabre,Alexies; Terreros,Gonzalo; López,Jessica; Miranda,Margarita; Di Scala,Karina.
Drying kinetics of quinoa-supplemented feed for laboratory rats during processing at 50, 60, 70, 80 and 90ºC was studied and modeled in this work. Desorption isotherm was obtained at 60ºC giving a monolayer moisture content of 0.04 g water/g d.m. The experimental drying curves showed that drying process took place only in the falling rate period. Several thin-layer drying equations available in the literature were evaluated based on determination coefficient (r²), sum squared errors (SSE) and Chi-square (χ2) statisticals. In comparison to the experimental moisture values, the values estimated with the Logarithmic model gave the best fit quality (r² &amp;gt;0.994, SSE &lt; 0.00015 and χ2 &lt; 0.00018), showing this equation could predict very accurately the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rat feed; Quinoa; Drying kinetics; Modeling; Statistical test.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000100021

Modeling gallic acid production rate by empirical and statistical analysis
Provedor de dados: 52
Autores: Kar,Bratati; Banerjee,Rintu; Bhattacharyya,Bimal Chandra.
For predicting the rate of enzymatic reaction empirical correlation based on the experimental results obtained under various operating conditions have been developed. Models represent both the activation as well as deactivation conditions of enzymatic hydrolysis and the results have been analyzed by analysis of variance (ANOVA). The tannase activity was found maximum at incubation time 5 min, reaction temperature 40ºC, pH 4.0, initial enzyme concentration 0.12 v/v, initial substrate concentration 0.42 mg/ml, ionic strength 0.2 M and under these optimal conditions, the maximum rate of gallic acid production was 33.49 mumoles/ml/min.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gallic acid; Modeling; Tannase; Caesalpinia digyna.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000500010

Evaluation of DSSAT soil-water balance module under cropped and bare soil conditions
Provedor de dados: 52
Autores: Faria,Rogério Teixeira de; Bowen,Walter Truman.
The performance of the soil water balance module (SWBM) in the models of DSSAT v3.5 was evaluated against soil moisture data measured in bare soil and dry bean plots, in Paraná, southern Brazil. Under bare soil, the SWBM showed a low performance to simulate soil moisture profiles due to inadequacies of the method used to calculate unsaturated soil water flux. Improved estimates were achieved by modifying the SWBM with the use of Darcy's equation to simulate soil water flux as a function of soil water potential gradient between consecutive soil layers. When used to simulate water balance for the bean crop, the modified SWBM improved soil moisture estimation but underpredicted crop yield. Root water uptake data indicated that assumptions on the original...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil moisture; Dry Bean; Modeling.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132003000400001

Models for the estimation of the physical quality of a Yellow Red Latosol (Oxisol) under pasture
Provedor de dados: 52
Autores: Ribon,Adriana Aparecida; Tavares Filho,João.
Models were developed considering the physical parameters penetration resistance (RP), bulk density (Ds), gravimetric moisture (U), clay content (Ag), sand content (Ar) and organic matter (MO) collected from a Yellow Red Latosol (Oxissol) medium texture under pasture from Rondonópolis county district, Mato Grosso State. Sampling was carried out in 34 fully randomized points in a 1 ha area to the depth of 0-20cm. The models were created using the Statistical Analysis System program (SAS) through which linear multiple regressions and correlations were made. Using the determination coefficient the following model was selected: RP=-12.134+0.004MO+7.6187Ds+0.131AG (R²=0.78). The evaluation of the organic matter and the soil clay content were important tools to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Penetration resistance; Organic matter; Texture.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000100004

Predictive modeling of Pseudomonas fluorescens growth under different temperature and pH values
Provedor de dados: 58
Autores: Gonçalves,Letícia Dias dos Anjos; Piccoli,Roberta Hilsdorf; Peres,Alexandre de Paula; Saúde,André Vital.
Abstract Meat is one of the most perishable foods owing to its nutrient availability, high water activity, and pH around 5.6. These properties are highly conducive for microbial growth. Fresh meat, when exposed to oxygen, is subjected to the action of aerobic psychrotrophic, proteolytic, and lipolytic spoilage microorganisms, such as Pseudomonas spp. The spoilage results in the appearance of slime and off-flavor in food. In order to predict the growth of Pseudomonas fluorescens in fresh meat at different pH values, stored under refrigeration, and temperature abuse, microbial mathematical modeling was applied. The primary Baranyi and Roberts and the modified Gompertz models were fitted to the experimental data to obtain the growth parameters. The Ratkowsky...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Meat; Deterioration; Modeling.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000200352

Canthaxanthin biosynthesis by Dietzia natronolimnaea HS-1: effects of inoculation and aeration rate
Provedor de dados: 58
Autores: Rostami,Forouzan; Razavi,Seyed Hadi; Sepahi,Abbas Akhavan; Gharibzahedi,Seyed Mohammad Taghi.
The interest in production of natural colorants by microbial fermentation has been currently increased. The effects of D-glucose concentration (3.18-36.82 g/L), inoculum size (12.5 x 10(9)-49.5 x 10(9) cfu cells/mL) and air-flow rate (1.95-12.05 L/L min) on the biomass, total carotenoid and canthaxanthin (CTX) accumulation of Dietzia natronolimnaea HS-1 in a batch bioreactor was scrutinized using a response surface methodology-central composite rotatable design (RSM-CCRD). Second-order polynomial models with high R² values ranging from 0.978 to 0.990 were developed for the studied responses using multiple linear regression analysis. The models showed the maximum cumulative amounts of biomass (7.85 g/L), total carotenoid (5.48 mg/L) and CTX (4.99 mg/L)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dietzia; Microbial canthaxanthin; Batch bioreactor; Response surface methodology; Modeling.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000200011

Microbial modeling of thermal resistance of Alicyclobacillus acidoterrestris CRA7152 spores in concentrated orange juice with nisin addition
Provedor de dados: 58
Autores: Peña,Wilmer Edgard Luera; Massaguer,Pilar Rodriguez de; Teixeira,Luciano Quintão.
The nisin effect on thermal death of Alicyclobacillus acidoterrestris CRA 7152 spores in concentrated orange juice (64ºBrix) was studied. Concentrations of 0, 50, 75 and 100 IU of nisin/ml juice, at temperatures of 92, 95, 98 and 102ºC were evaluated. The quadratic polynomial model was used to analyze the effects of the factors and their interaction. Verification of surviving spores was carried out through plating in K medium (pH 3.7). The results showed that the D values without nisin addition were 25.5, 12.9, 6.1 and 2.3 min for 92, 95, 98 and 102ºC respectively. With addition of nisin into the juice there was a drop of heat resistance as the concentration was increased at a same temperature. With 30, 50, 75, 100 and 150 IU/ml at 95ºC, the D values were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alicyclobacillus acidoterrestris; Orange juice concentrate; Modeling.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000300024

Comparison of Regression and Neural Networks Models to Estimate Solar Radiation
Provedor de dados: 117
Autores: Bocco,Mónica; Willington,Enrique; Arias,Mónica.
The incident solar radiation on soil is an important variable used in agricultural applications; it is also relevant in hydrology, meteorology and soil physics, among others. To estimate this variable, empirical models have been developed using several parameters and, recently, prognostic and prediction models based on artificial intelligence techniques such as neural networks. The aim of this work was to develop linear models and neural networks, multilayer perceptron, to estimate daily global solar radiation and compare their efficiency in its application to a region of the Province of Salta, Argentina. Relative sunshine duration, maximum and minimum temperature, rainfall, binary rainfall and extraterrestrial solar radiation data for the period...
Tipo: Journal article
Palavras-chave: Modeling; Prediction; Linear regression; Multilayer perceptron.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000300010

Kinetic Study of Convective Drying of Blueberry Variety O’neil (Vaccinium corymbosum L.)
Provedor de dados: 117
Autores: Vega-Gálvez,A; Lemus-Mondaca,R; Tello-Ireland,C; Miranda,M; Yagnam,F.
The aim of this research was to study and to model the drying kinetics of the blueberry Vaccinium corymbosum L.) at three temperatures (60, 70 and 80 ºC) with an airflow of 2.0 ± 0.2 m s-1. Modeling of the desorption isotherm was carried out with the GAB (Guggenheim, Anderson and de Boer) equation, showing a good fit to experimental moisture data, giving as a result a monolayer moisture level of 0.084 g water g-1 dm. Newton, Henderson-Pabis, Page, Modified Page and Logarithmic mathematical models were applied in the study and in the modeling of the drying kinetics of this fruit. Kinetic parameters k of each model showed dependence on temperature, and were evaluated by an Arrhenius-type equation, with an activation energy of between 36.2 and 54.5 kJ mol-1....
Tipo: Journal article
Palavras-chave: Blueberry; GAB; Drying; Modeling; Statistical tests.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000200006

Methodological proposal for predictive and cartographic modeling of insect population: Semidalis kolbei case, the Araucanía Region, Chile
Provedor de dados: 118
Autores: Ojeda,Nelson; Rebolledo,Ramón; Calzadilla,Soraya; Soto,Hector; Morales,Luis.
Semidalis kolbei occupies a significant area of south central Chile. However, it is necessary to determine and predict the occurrence of the insect at a given site. The aim of this research is to analyze the potential spatial distribution of S. kolbei in La Araucanía Region of Chile. The study compares ordinary kriging (OK) interpolation methods, geographically weighted regression (GWR) and global regression (GR). The following variables were used in the investigation: topography (altitude, aspect, and slope), distance from the littoral, climate, and geographical variables (latitude and longitude). Of the models evaluated, the GWR proved to be the most successful. This model revealed a marked east-west gradient in the distribution of S. kolbei and a...
Tipo: Journal article
Palavras-chave: Araucanía Region; Chile; Modeling; Potential spatial distribution; Semidalis kolbei.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202011000300007

Increasing yoghurt daily production with modeling and simulation process
Provedor de dados: 65
Autores: Araújo,Adolfo Vicente; Queiroz,Daniel Marçal de; Arcanjo,Gemima Santos; Dias,Santos Henrique Brant; Alves,Renato Martins; Pinto,Francisco de Assis de Carvalho; Valente,Domingos Sárvio Magalhães.
ABSTRACT:  The objective of this research was to use the modeling and computer simulation to support decision makers, aiming to increase the productive capacity of the agro-industry of LaticínioFunarbe. Specifically, it has modeled the current yoghurt production sector for simulation that enables it to meet the new demand. The Arena 14.7 simulation software was used to conduct the modeling. To validate the model, the output of yoghurt production collected at the factory for three months was compared with the output from the simulated computational model. Two indicators were established to perform analyzes of four different scenarios. The implemented model resulted in an increase in the production capacity of 5,000L.d-1 of yoghurt, corresponding to a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Computer simulation; Cenario analysis; Yoghurt; Dairy industry.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000100751

Estimating the development of landrace and improved maize cultivars as a function of air temperature
Provedor de dados: 65
Autores: Langner,Josana Andreia; Streck,Nereu Augusto; Dalmago,Genei Antonio; Reiniger,Lia Rejane Silveira; Durigon,Angelica; Silva,Stefanía Dalmolin da; Lago,Isabel; Scheffel,Lúcio Gabriel; Poersch,Anderson Haas.
ABSTRACT: The objective of this study was to determine the maximum development rates for the phases of emergence, vegetative and reproductive, and to test the performance of the Wang and Engel (WE) model for simulating the development of landrace and improved maize cultivars sown on different dates. Model calibration was with data collected from a field experiment with a sowing date on December 13, 2014, and the model was tested with independent data from experiments with five sowing dates (August 20 and November 4, 2013, February 3 and August 15, 2014, and January 7, 2015) in Santa Maria, RS. The experiment was a complete randomized block design with four replicates. The dates of emergence (EM), silking (R1), and physiological maturity (R6) of two...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zea mays L; Modeling; Phenology; Developmental stages.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001001737

Emulsion of systems containing egg yolk, polysaccharides and vegetable oil
Provedor de dados: 64
Autores: Souza,Clitor Junior Fernandes de; Rojas,Edwin Elard Garcia.
This work characterizes the emulsifying properties of systems containing egg yolk (0.1; 1.0 and 2.5 % w/v) and polysaccharides (xanthan gum, carrageen, pectin and carboxymethylcellulose) and three different vegetable oils (sunflower, canola, and palm oils). Emulsifying activity and emulsion stability were measured of each combination and it was found the effect of the oil on emulsion stability correlated to the amount of monounsaturated fatty acid. Additionally, increased egg yolk concentration increased emulsifying activity by reducing coalescence of oil droplets. Lastly, 2.5% egg yolk and 0.2% polysaccharide generated emulsions with high emulsifying activity, excellent stability, and droplet size of 4.32 µm.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modeling; Emulsifying activity; Hydrophilic properties.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542012000500007

Estimation of sediments produced in a subbasin using the Normalized Difference Vegetation Index
Provedor de dados: 64
Autores: Lense,Guilherme Henrique Expedito; Moreira,Rodrigo Santos; Bócoli,Fernanda Almeida; Avanzi,Junior Cesar; Teodoro,Alexandre Elias de Miranda; Mincato,Ronaldo Luiz.
ABSTRACT Among the parameters considered by the Revised Universal Soil Loss Equation (RUSLE), the soil cover and management factor (C) is the main human influenced factor affecting the estimation of water erosion, and one of the most sensitive to spatiotemporal variations. Consequently, this study aims to compare the efficiency of C factor estimates obtained from the literature for each land-use class (Clit) and by calculation based on the Normalized Difference Vegetation Index (CNDVI). We test the hypothesis that soil loss estimates based on CNDVI approach are more accurate than those based on Clit. Water erosion was estimated based on soil morphological, physical, and chemical properties in addition to climate, relief, management practices, and land use...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil conservation; Water erosion; Modeling; RUSLE.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542020000100214