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| Registros recuperados: 9.251 | |
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| Minervini,Mariana G; Morrás,Héctor J. M; Taboada,Miguel A. |
| Los incendios constituyen disturbios de muy diverso origen y variadas implicancias. Además de los efectos sobre la vegetación, pueden afectar los componentes y las propiedades de los suelos. Las modificaciones en los suelos, a su vez, suelen incrementar los procesos de erosión, de transporte de sedimentos y, como consecuencia de lo anterior, también de inundaciones. La mayor parte de los estudios sobre los impactos edáficos del fuego han tenido como objeto los efectos sobre la materia orgánica y otras propiedades químicas y, en menor medida, los efectos sobre las propiedades físicas y mineralógicas. El propósito de este trabajo fue revisar el estado del arte en la literatura sobre estos últimos efectos, que han sido menos explorados. Se ha encontrado que... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Incendios; Estructura del suelo; Agregación; Porosidad; Hidrofobicidad; Textura; Minerales; Color. |
| Ano: 2018 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2018000100012 |
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| Sione,Silvana M. J; Ramírez,Adriana C; Sasal,María C; Paravani,Enrique V; Wilson,Marcelo G; Gabioud,Emmanuel A; Polla,Wanda; Repetti,María R; Oszust,José D. |
| El objetivo fue evaluar la fitotoxicidad de un formulado comercial de glifosato (sal potásica al 62%, equivalente a 506 g p.a./L) sobre Lemna gibba, a campo y en laboratorio. El estudio a campo se desarrolló en un embalse asociado a un ambiente agrícola. Allí se realizó un análisis temporal, con observaciones en cuatro momentos en función de la proximidad a la fecha de aplicación del herbicida en el lote agrícola y al primer evento de precipitación que generó escurrimiento. La fitotoxicidad se evaluó sobre biomasa seca por fronde (BF) y contenido total de clorofila (CTC). Durante 15 días, en condiciones controladas se ensayaron 8 tratamientos con exposición a concentraciones de glifosato que variaron entre 0 y 15 mg/L. Se determinó el crecimiento... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicida; Efectos fitotóxicos; Bioindicadores; Lenteja de agua; Agroecosistemas. |
| Ano: 2018 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2018000100001 |
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| Alberti,Juan; Daleo,Pedro; Iribarne,Oscar. |
| Según la teoría del nicho ecológico, la composición de especies en un lugar dado debería estar determinada por la conjunción de los factores bióticos y abióticos que allí actúan. En cambio, la teoría neutral propone que las especies son equivalentes y que la composición de ensambles locales está dada, entonces, por procesos de colonización y extinción independientes de las especies. Hoy en día se sabe que es difícil encontrar en la naturaleza ensambles puramente neutrales o puramente basados en el nicho ecológico, sino que lo que priman son ensambles intermedios. Los ensambles con una impronta fuerte del nicho ecológico están muy influidos por las interacciones interespecíficas o por los forzantes ambientales, mientras que los ensambles neutrales están más... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Patrones de diversidad; Modelo nulo. |
| Ano: 2018 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2018000100013 |
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| Furtado,Dermeval A.; Braz,José R. B.; Nascimento,Jose W. B. do; Lopes Neto,José P.; Oliveira,Daniele L.. |
| ABSTRACT The aim of this research was to evaluate the performance of Japanese quail (Coturnix coturnix japonica), with 94 (+49) days of age, through the production and quality of the eggs, with the birds kept in environments illuminated with LED lamps in the colors white, blue and red. The experimental design was a completely randomized design with three treatments (lamp colors) and seven replications. In the three environments, the relative air temperature averages can be considered above the thermal comfort zone for quails; however, the black globe temperature index, humidity and the thermal radiation load can be considered comfortable. The laying percentage of the birds kept under white LED was inferior to those maintained in the red LED. The feed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Quail breeding; LED lamp; Lighting technology. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000400504 |
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| Lahr,Francisco A. R.; Nogueira,Marta C. de J. A.; Araujo,Victor A. De; Vasconcelos,Juliano S.; Christoforo,André L.. |
| ABSTRACT Over the years, the species of eucalyptus has become a multipurpose raw material. In addition, the most relevant aspect of the use for various purposes is related to the production of a high quality wood, coming from short duration plantations, which is fundamental to the current demand of the industries. However, its use in civil construction has not yet reached a level of importance, due to the low knowledge of many of its resistance properties and the consequent popular fear in the use of reforestation woods, in particular the Eucalyptus grandis. This research investigated its main mechanical properties, aiming to reinforce its constructive applications in wood structures. For this, two physical properties and fourteen mechanical properties, in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rose Gum; Eucalypt; Mechanical properties; Bulk density. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000500642 |
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| Noronha,Rafael H. F.; Zerbato,Cristiano; Silva,Rouverson P. da; Ormond,Antonio T. S.; Oliveira,Mailson F. de. |
| ABSTRACT The peanuts harvesting mechanization is affected by the soil physical characteristics and it may increase the losses due to the production of pods in subsurface. The objective of the experiment was to identify the clusters through multivariate exploratory approaches from similarity in six soil textures (very clayey, clayey, silty clayey loam, clayey loam, sandy loam and sandy) in the state of São Paulo, Brazil, determining the main agronomic variables that most influenced the clustering division to assist the decision-making process in peanuts mechanized harvesting. The data were analyzed by the multivariate exploratory that is performed to simplify the description of a set of interrelated variables, using: yield, maturity, soil and pod moisture... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil textural classes; Arachis hypogaea L.; Principal components analysis. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000200244 |
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| Wrublack,Suzana C.; Mercante,Erivelto; Boas,Marcio A. Vilas; Prudente,Victor H. R.; Silva,Jefferson L. G.. |
| ABSTRACT This study demonstrates using remote sensing, geographic information systems and multivariate statistics to study water quality in an agricultural watershed. The monitoring of water quality in the watershed of Lontras's river in the southwestern region of the State of Paraná had been done in 2012 and 2013 with a multi-parameter probe in ten sites that were defined upstream and downstream watershed, during four different seasons. Mosaicked images were used from Google Earth, Digital Elevation Model and soil types of maps, defined as the explanatory variables. The definition of the areas of influence and multivariate statistical techniques, particularly the Redundancy Analysis (RDA), were used for the correlation between variables. In a spring area,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geoprocessing; Mapping land use and occupation; Water quality. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000100074 |
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| Tavares,Bartira de O.; Pereira,Danilo F.; Salgado,Douglas D'Alessandro; Mac-Lean,Priscilla A. Bustos. |
| ABSTRACT The conventional production of eggs in cage systems is intense and compromises the laying hens welfare. More demanding consumer markets have been pushing to abolish the use of cages and thus provide better welfare in poultry laying. This research evaluated the mortality, production, and egg quality of two alternative production systems (free-range and organic free range free-range) and compared them with the conventional system. The research was carried out in two commercial poultry farms and the variables egg weight, shell egg resistance, Haugh unit, mortality and production were recorded during eight months. The results showed that the conventional system presented better production, lower mortality and better shell egg quality. The alternative... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Poultry egg farming; Alternative egg production; Quality of eggs; Animal welfare. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000400478 |
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| França,Michelle M.; Fernandes Filho,Elpidio I.; Ferreira,Williams P. M.; Lani,João L.; Soares,Vicente P.. |
| ABSTRACT During image acquisition, is usually chosen scenes with a lesser cloud cover to avoid loss of spectral information. However, when training samples are collected for image classification, the user finds shadowed areas. Such situation is similar to the presence of clouds since spectral information of these classes is the same in all optical bands of the sensor. This fact becomes more pronounced in mountainous relief areas due to shadow projection on the terrain, which can vary among all seasons during the solar year. With the goal to obtain images with a lower presence of shadow, it was simulated, under the same relief conditions, shading variation in function of latitude (0° to 40° S). Solar radiation models were processed for the days and times... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Landsat; Remote sensing; Solar radiation. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000500728 |
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| Amraei,Somaye; Mehdizadeh,Saman A.; Nääs,Irenilza de A.. |
| ABSTRACT The objective of this study was to process digital images to investigate the possibility of broilers body weight estimation based on the dynamic model. For this experiment, 2440 images were recorded by a top-view camera from 30 birds. An ellipse fitting algorithm was applied to localize chickens within the pen, by using a generalized Hough transform. Chickens’ head and tail were removed efficiently using the Chan-Vese method. After that, using image processing, six body measures were calculated. Next, they were used to design a Transform Function (TF) model with weight measurements as output. Second-order dynamic models were used to predict the weight of life broiler chicken, without delay, stable and with the highest R2 were predominantly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Automatic weight estimation; Image processing; Ellipse fitting; Transfer function modeling. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000500776 |
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| Zeymer,Juliana S.; Corrêa,Paulo C.; Oliveira,Gabriel H. H. de; Baptestini,Fernanda M.; Faria,Igor L.. |
| ABSTRACT This study aimed to determine the thermodynamic properties of sorption processes (desorption and adsorption) of rice in the husk, cv. Urucuia. A static-gravimetric method was used to reach equilibrium moisture content at different temperatures (10, 20, 30, 40, and 50 °C ± 1°C) and relative humidity levels (10, 30, 50, 70, and 90 % ± 2%). A decrease in moisture content led to an increment of the integral isosteric heat of sorption, indicating a higher demand for energy to remove moisture from the product. Differential entropy of sorption decreased along with a moisture content increment, with higher values for desorption. This indicates a higher mobility of water molecules during desorption if compared to adsorption. Gibbs free energy decreased... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Equilibrium moisture content; Integral isosteric heat of sorption; Differential entropy; Gibbs free energy; Enthalpy-entropy compensation theory. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000300369 |
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| Registros recuperados: 9.251 | |
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