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| Registros recuperados: 152 | |
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| Ishpekov, Stoyan Savov. |
| The investigation aims at modelling the dynamics of rotational vibration generator, which is widely used for driving flow fruit detachers at harvesting of many crops like grape, tomatoes, blueberries, raspberries, chokeberry, black currant, sesame seeds etc. The research on this model has been digitally performed by software, written in FORTRAN and by using the LabView environment as input-output interface. Identification of unknown model coefficients has been carried and their influence upon precision of the model has been determined. The effect of vibration generator parameters upon its dynamic characteristics has been defined. The synthesized model reaches a relative error for the carrier angular amplitude of 0.48 % compared to the one, determined by an... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agricultural engineering flow fruit detacher; Rotation vibration generator; Modelling. |
| Ano: 2018 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3940 |
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| Pousse, Emilien; Flye-sainte-marie, Jonathan; Alunno-bruscia, Marianne; Hegaret, Helene; Rannou, Eric; Pecquerie, Laure; Marques, Goncalo M.; Thomas, Yoann; Castrec, Justine; Fabioux, Caroline; Long, Marc; Lassudrie, Malwenn; Hermabessiere, Ludovic; Amzil, Zouher; Soudant, Philippe; Jean, Fred. |
| As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dinoflagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditions (trophic sources, temperature). This study aimed to develop a mechanistic model coupling the kinetics of PST accumulation and bioenergetics in C. gigas based on Dynamic Energy Budget (DEB) theory. For the first time, the Synthesizing Units (SU) concept was applied to formalize the feeding preference of oysters between non-toxic and toxic microalgae. Toxin intake and accumulation were both dependent on the... |
| Tipo: Text |
Palavras-chave: Alexandrium minutum; Paralytic shellfish toxins (PST); Dynamic Energy Budget (DEB); Modelling; Pacific oyster. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00455/56662/58407.pdf |
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| Bergmann, Holger; Thomson, Kenneth J.. |
| A modified version of a system dynamics model constructed for an EU-wide case-study project (TOPMARD) using STELLA software was used to simulate the effects of a number of development scenarios for a remote rural area in Northern Scotland, i.e. Caithness & Sutherland, which is characterised by multifunctional agriculture. In this paper, the context of the modelling work in policy and socioeconomic terms is first described. This is followed by the specification of the model and of the modelling scenarios, one of which relates to the “decommissioning” (run-down) of a major industrial site (Dounreay) within the area. The modelling results are discussed, in terms of regional population, land use, economic and other terms, from 2001 to 2015/2031. Finally,... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Modelling; Multifunctionality; Input-output; Systems dynamics; Rural policy; Agricultural and Food Policy; Community/Rural/Urban Development; Public Economics; Research Methods/ Statistical Methods. |
| Ano: 2008 |
URL: http://purl.umn.edu/6596 |
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| Jones, Randall E.; Cacho, Oscar J.; Sinden, Jack A.. |
| An appropriate economic framework for valuing the benefits of weed management technologies is to treat weeds as a renewable resource stock problem. Consequently, the weed seed bank is defined as a renewable resource that changes through time due to management and seasonal conditions. The goal of decision-makers is to manage this (negative) resource so as to maximise returns over some pre-specified period of time. A modelling framework is presented for evaluating the biological and economic effects of weed management. The framework includes population dynamics, water balance, crop growth, pasture growth and crop/pasture rotation models for measuring the physical interactions between weeds and the environment. These models link in with numerical optimal... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Weeds; Modelling; Dynamic analysis.; Land Economics/Use. |
| Ano: 2003 |
URL: http://purl.umn.edu/57902 |
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| Roeva,Olympia; Pencheva,Tania; Tzonkov,Stoyan; Arndt,Michael; Hitzmann,Bernd; Kleist,Sofia; Miksch,Gerchard; Friehs,Karl; Flaschel,Erwin. |
| The paper presents the implementation of multiple model approach to modelling of Escherichia coli BL21(DE3)pPhyt109 fed-batch cultivation processes for an extracellular production of bacterial phytase. Due to the complex metabolic pathways of microorganisms, the accurate modelling of bioprocesses is rather difficult. Multiple model approach is an alternative concept which helps in modelling and control of complex processes. The main idea is the development of a model based on simple submodels for the purposes of further high quality process control. The presented simulations of E. coli fed-batch cultivation show how the process could be divided into different functional states and how the model parameters could be obtained easily using genetic algorithms.... |
| Tipo: Journal article |
Palavras-chave: Genetic algorithms; Modelling; Multiple model approach. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000400012 |
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| Kahuda, Daniel; Vach, Marek; Cerba, Otakar; Krivanek, Zbynek; Jezek, Jan; Charvat, Karel; Vohnout, Premysl; Dvorak, V.. |
| NASYP is an online Geoportal tool being developed in cooperation with state and regional authorities to improve insufficient practices based on implementation of Directive nr. 2003/105/ES on the control of major-accident hazards involving dangerous substances. The tool is applicable for managing the permits, reporting and regular monitoring issues. Furthermore, it’s applicable for a risk assessment and a rapid management of disasters in the initial phase. There’re simple modeling tools included to simulate early stages of the contamination caused by disasters occurred to be used for decision making and effective use of emergency services. In this manner, there’re low atmospheric and surface water pollutions taken into account. For the study area, Liberec... |
| Tipo: Journal Article |
Palavras-chave: Spatial data; Geoportal; Risk management; Modelling; Research and Development/Tech Change/Emerging Technologies; Research Methods/ Statistical Methods; Risk and Uncertainty; GA; IN. |
| Ano: 2011 |
URL: http://purl.umn.edu/116384 |
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| Priour, Daniel. |
| Trawls energy efficiency is greatly affected by the drag, as well as by the swept area regarding pelagic trawls and by the swept width for bottom ones. The drag results in an increase of the energy consumption and the sweeping influences the catch. In order to reduce the drag per swept area (or width) a numerical tool dedicated to the automatic optimisation of the trawl design has been developed. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For each step the best-modified design, in terms of drag per swept area (or width), is kept. Such a methodology was used in two cases: which show a 43% increase in energy efficiency regarding the pelagic trawl case and 27% for the bottom trawl... |
| Tipo: Text |
Palavras-chave: Swept width; Swept area; Drag; Fuel consumption; Optimisation; Modelling; Trawl; Fishing gears. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6583.pdf |
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| Stott, Alistair W.. |
| Endemic disease of animals is an economic problem as it deprives humans of scarce resources that might otherwise satisfy human wants. Optimisation methods identify the strategies that minimise this economic problem. Given the potentially vast extent of the deprivation, not only in terms of lost wealth but also in terms of animal welfare, human health and environmental damage, this subject offers great benefits to decision-makers from the individual farm to the global level. This paper uses examples to illustrate the basic economic principles concerned. It shows how these principles may be extended to deal with current limitations in theory and practice. Lack of data is a common problem that may be dealt with by using computer simulation, theoretical... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Economics; Decision analysis; Optimisation; Modelling; Endemic disease; Knowledge transfer; Health Economics and Policy. |
| Ano: 2006 |
URL: http://purl.umn.edu/46000 |
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| Perez Dominguez, Ignacio; Holm-Muller, Karin. |
| In light of international discussions on a possible opt-in of the agricultural sector to the current European emission trading system for greenhouse gases, the objective of this article is to present a feasible implementation strategy for a market of emission permits in European agriculture and to simulate its economic effects within the regionalised agricultural sector model CAPRI. With this purpose, we compare the effects of a 15% reduction of greenhouse gas emissions from European agriculture with and without a trading scheme. Our findings suggest that if significant emission abatement is to be achieved in the agricultural sector, efficiency gains from expanding the current emission trading scheme to this sector can be appreciable. An additional finding... |
| Tipo: Journal Article |
Palavras-chave: Climate gas emissions; Emission trading; Abatement costs; Agricultural policy; Modelling; Agricultural and Food Policy. |
| Ano: 2007 |
URL: http://purl.umn.edu/96766 |
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| Institut de Recherche pour le Développement, Paris (France); Fall, Massal. |
| Français - Les traits essentiels de la côte sénégalaise, repères historiques de la pêche, communautés de pêcheurs, caractéristiques des flottes et modes d’accès à la ressource et d’interaction sont analysés. Les caractéristiques, tendances décroissantes de l’abondance,niveaux d’exploitation, mesures d’aménagement, relations interspécifiques, changements potentiels et sources de variation des stocks démersaux côtiers sont précisés. Les notions de tactiques et stratégies de pêche sont passées en revue, conceptualisées puis étudiées.Le modèle «Dynamique Conjointe Exploitation Ressource» utilisé repose sur la définition de 4 typologies. L’utilisation de méthodes de classification et de connaissances d’experts conduit à considérer 32 stocks, 31 strates, 82... |
| Tipo: Theses and Dissertations |
Palavras-chave: Fisheries; Demersal fisheries; Modelling; Stocks; Ecosystems; Community fishing; Inland waters; Marine water; Hydrologic cycle; Fishermen; Fishing fleet; Shrimp fisheries; Capture fisheries; Fisheries management; Trawling; Artisanal fishing; Fishing licenses. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/5004 |
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| Registros recuperados: 152 | |
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