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| Registros recuperados: 55 | |
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| Boutron, Olivier; Bertrand, Olivier; Fiandrino, Annie; Hoehener, Patrick; Sandoz, Alain; Cherain, Yves; Coulet, Eric; Chauvelon, Philippe. |
| The spatiotemporal structure of wind-driven circulation patterns and associated water exchanges can drive important bio-hydrodynamic interactions in shallow lagoons. The Vaccares lagoon system is a complex shallow hydrosystem located in the central part of the Rhone Delta (France). It is internationally recognized as part of a biosphere reserve within the framework of UNESCO's Man and Biosphere Programme, and as a RAMSAR site. Due to its frequent occurrence in this area, and considering the shallowness of the Vaccares lagoon system, wind is assumed to play a major role in the hydrodynamic and biological processes. In this study, a hydrodynamic model was developed to investigate the structure of wind-driven circulations in the Vaccares lagoon system, to... |
| Tipo: Text |
Palavras-chave: Coastal lagoon; Mathematical model; Hydrodynamics; Calibration; Validation; Wind-driven circulation. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00303/41382/40558.pdf |
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| Lima,Ernesto A B F; Ferreira,Claudia P; Godoy,Wesley A C. |
| Ecological modeling is an important tool for investigating dynamic behavior patterns in populations, trophic interactions, and behavioral ecology. However, the ecological patterns that reflect population oscillation trends are often not clearly visible without analytical instruments such as ecological models. Thus, ecological modeling plays a fundamental role in describing demographic processes that are important for population dynamics. Ecological models, besides making possible the visualization of ecological patterns, may also reveal patterns of population persistence in many trophic systems, including prey-predator or host-parasitoid relationships, interactions that are commonly present in integrated pest management programs. In this forum, we present... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Theoretical ecology; Integrated pest management; Mathematical model. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2009000600001 |
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| Ribas,Giovana Ghisleni; Streck,Nereu Augusto; Duarte Junior,Ary José; Ribeiro,Bruna San Martin Rolin; Pilecco,Isabela Bulegon; Rossato,Ioran Guedes; Richter,Gean Leonardo; Bexaira,Kelin Pribs; Pereira,Vladison Fogliato; Zanon,Alencar Junior. |
| Abstract: The objective of this work was to model, in the SimulArroz model, the three flood-irrigated rice (Oryza sativa) cultivars currently most grown in the state of Rio Grande do Sul, Brazil. The experiments to calibrate and validate the model were conducted in the municipalities of Cachoeirinha, Santa Maria, Uruguaiana, Santa Vitória do Palmar, and Cachoeira do Sul during four crop seasons. The number of leaves, phenology, aboveground dry matter biomass, and yield of each cultivar were evaluated. The results showed a slight overestimate of the R1, R4, and R9 stages; however, overall, the SimulArroz model had a good performance in simulating rice phenology for the three studied genotypes. Furthermore, the model had a reasonable accuracy in simulating... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Mathematical model; Yield. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2020000101001 |
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| Demuner,Leandro Félix; Suckeveris,Diana; Muñoz,Julian Andrés; Caetano,Vinicius Camargo; Lima,Cesar Gonçalves de; Faria Filho,Daniel Emygdio de; Faria,Douglas Emygdio de. |
| Abstract: The objective of this work was to investigate adjustments of the Gompertz, Logistic, von Bertalanffy, and Richards growth models, in male and female chickens of the Cobb 500, Ross 308, and Hubbard Flex lines. Initially, 1,800 chickens were randomly housed in 36 pens, with six replicates per lineage and sex, fed ad libitum with feed according to gender, and bred until 56 days of age. Average weekly body weight for each line and sex was used to estimate model parameters using the ordinary least squares, weighted by the inverse variance of the body weight and weighted with a first-order autocorrelated error structure. Weighted models and weighted autocorrelated error models showed different parameter values when compared with the unweighted models,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Autocorrelated errors; Autoregressive model; Poultry science; Homogeneity of variance; Mathematical model; Weighting structures. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001201241 |
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| Santos,Maria Aparecida do Nascimento dos; Bertol,Ildegardis; Kaufmann,Danieli Schneiders; Mecabô Júnior,José; Bagio,Bárbara. |
| Abstract: The objective of this work was to determine adjustment parameters for the revised universal soil loss equation (Rusle) of a soil subjected to pig slurry application. Treatments consisted of 0, 50, 100, and 200 m3 ha-1 pig slurry (PS), after the cultivation of black oat (Avena strigosa), besides the application of 50 m3 ha-1 PS for six times onto the soil surface in a temporal sequence, and a control treatment of soil without cultivation and without pig slurry application. The evaluations were performed for black oat shoot dry mass, root mass and crop residues semi-incorporated into the soil (RMR), soil losses by means of simulated rain, and the parameters for water erosion modeling. The pig slurry application onto soil surface caused a reduction... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Avena strigosa; Cultural residue factor; Mathematical model; Simulated rain; Soil consolidation factor; Water erosion. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018001001167 |
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| Carvalho, Leandro Bernardino de. |
| Atualmente, dois dos grandes desafios com os quais o agronegócio brasileiro, responsável por aproximadamente 33% do PIB nacional (SECEX, 2005), se depara em seu constante crescimento são a alta dependência de produtos químicos (fertilizantes) para que sua fronteira agrícola se expanda e, conseqüentemente, as enormes distâncias (e custos de transportes) que essas fronteiras impõem para que sejam vencidas, tanto para o recebimento de insumos de produção, quanto para o fornecimento de seus produtos finais. Particularmente, a região Centro-Oeste brasileira, formada pelos Estados de Goiás, Mato Grosso, Mato Grosso do Sul e Distrito Federal, se enquadra em ambos os pontos – possui grandes fronteiras agrícolas a serem exploradas e, ao mesmo tempo, se localiza a... |
| Tipo: Presentation |
Palavras-chave: Logística; Transporte; Modelo matemático; Fertilizantes; Logistics; Transport; Mathematical model; Fertilizers; Agribusiness. |
| Ano: 2008 |
URL: http://purl.umn.edu/119008 |
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| Gallo,Sarita Bonagurio; Tedeschi,Luis Orlindo. |
| ABSTRACT: Intake is a multifactorial process that is influenced by animal type, environmental factors, and diet characteristics. Sheep, especially, have specific eating habits, with a greater selection of ingested feed compared to cattle. Thus, predictive equations for dry matter intake (DMI) must constantly be reviewed. The objective of this study was to combine different adjustment factors to develop one continuous adjustment factor for predicting the DMI of pregnant, dry, and lactating ewes. The equations evaluated for non-lactation ewes accounts for metabolic body weight and weight gain, and the equation for lactating ewes includes milk production and its fat content. The database used in this study was pooled from hair sheep ewes, two to four years... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mathematical model; Nutrition model; Prediction; Requirement; Sheep. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162021000200502 |
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| Florentino,Helenice de Oliveira. |
| Anaerobic digesters have been highlighted due to the current energy crisis and its consequent search for alternative energy sources, allied to the intense process of livestock farming and agriculture modernization, which besides demanding a lot of energy, produces a great amount of crop and animal residues, most of the times generating sanitary problems. The aim of this work is to provide a mathematical tool to establish parameters for projects of construction of rural digesters, considering the response to energy demand, the suitability of the dimensions of the systems, yield factors and the guarantee of functionality. Non-linear optimization models, of easy resolution, for the three main types of rural digesters were formulated in this way. With the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mathematical model; Optimization; Parameters for designing. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000100028 |
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| Campostrini,Eliemar; Yamanishi,Osvaldo Kiyoshi. |
| Four genotypes of papaya (Carica papaya L.) two from the 'Solo' group (Sunrise Solo and Improved Sunrise Solo line 72/12) and two from the 'Formosa' group (Tainung 02 and Known-You 01), grown in Macaé, RJ, Brazil (lat. 22(0) 24' S, long. 41(0) 42' W), were used in this study. Twenty-five mature leaves from each genotype were sampled four and five months after seedling transplant to the field to determine the length of the leaf central vein (LLCV) and the leaf area (LA). According to covariance analyses there were no significant differences in the slope and intercept of the mathematical models calculated for each genotype. Thus, a single mathematical model (Log LA = 0.315 + 1.85 Log LLCV, R²=0.898) was adjusted to estimate the LA using the length of LLCV... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carica papaya; Mathematical model; Genotypes. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162001000100007 |
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| Registros recuperados: 55 | |
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