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| Registros recuperados: 153 | |
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| Lucena, Leandro Ricardo Rodrigues de; Holanda, Marco Aurélio Carneiro de; Holanda, Mônica Calixto Ribeiro de; Anjos, Marcelo Lopes dos. |
| This study adjusted different regression models to describe the growth pattern of meat quails from birth to 42 days of age. Data of 300 male quails were used. Weight and height information of all quails were collected weekly from the 1st to the 42nd day of age. Body weight of poultry was subjected to the polynomial, logistic, Gompertz, Weibull, and log-normal regression models. The criteria used to choose the best model to explain the growth curve of quails were the coefficient of determination of the model, Akaike’s information criterion, sum of squared residuals and Willmott’s index. For all the models used, the variables age and height were significant to explain the weight of quails. The polynomial (R² = 99.99%, AIC = 24.68, SSR = 27.5, d = 0.9999) and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Modelling; Poultry; Regression model.. |
| Ano: 2018 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/42563 |
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| Sven Nimmermark. |
| In regions with a colder climate the use of heat energy for climatization of greenhouses can be significant. Beside outdoor temperatures and climate also transpiration affects the use of heat energy since heating and ventilation or dehumidification may be required in order to keep the humidity in the greenhouse below levels which may lead to plant diseases. A reliable model is a powerful tool to predict energy use for greenhouse cultivation. Thus, a mechanistic model including transpiration and energy use for dehumidification and hourly output data was developed from an older simpler model. To be reliable, modelled data must fit with real data. The aim of the present study is to compare measured and modelled use of heat energy. Thus, energy use for a... |
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Palavras-chave: Greenhouses; Energy; Measurements; Modelling. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3100 |
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| Almaliki, Salim; Alimardani, Reza; Omid, Mahmoud. |
| Due to the ascending importance of energy in the world, prediction and optimization of Fuel Consumption (FC) in agricultural tasks is merit to consideration. In this study a Massey Ferguson (MF285) tractor was implemented with a low cost and precise data acquisition system as a means to record and monitor the affectual parameters on FC such as forward speed and instant fuel flow rate during field operation. Field experiments were carried out in the experimental farm of Agricultural Engineering Department of Tehran University, Karaj province, Iran, which had loamy soil texture. A mouldboard plow was used as tillage toll during the experiments at various tillage depths, engine speeds, forward speeds, tire inflation pressures, moisture contents and cone... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fuel consumption; Massey Ferguson (MF285); Modelling; Data logging system. |
| Ano: 2016 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3776 |
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| SANUSI, Mayowa Saheed; Akinoso, Rahman. |
| This study was designed to evaluate and model the impacts of processing parameters (steaming time, soaking time, paddy moisture content and soaking temperature) on the energy consumption of five rice varieties (NERICA 8, FARO 52, FARO 61, FARO 60 and FARO 44). Energy consumption in the cleaning, soaking, steaming, drying, dehusking, polishing and grading operations were estimated by fitting data on labour, fuel and electricity consumption, time and machine efficiency into standard equations to determine total energy consumption. The energy consumptions were separately modelled using Taguchi and Artificial Neural Network (ANN) techniques for each rice variety. The accuracy of models was determined using the coefficient of determination (R2) and Mean Square... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artificial neural network; Energy Consumption; Modelling; Rice varieties; Taguchi. |
| Ano: 2022 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/7235 |
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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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| Odey, Simon Ogbeche. |
| Abstract: Field experiment was conducted at the teaching and research farm of Cross River University of Technology, Faculty of Agriculture and Forestry, Obubra Campus. The study was aimed at finite modelling of growth and yield of Okra (Abelmoschus esculentus L.) using different tillage systems. Randomised Complete Block Design (RCBD) was used in the field, 1,024m2 with three treatments and three replicates. These treatments were Conventional, Conservative and Zero tillage. Each treatment had three replicates of size 8m x 8m, separated from each other by 2m for manoeuvring of the tractor. Planting of okra and other cultural practices were carried out. Soil samples were collected for analysis in the laboratory. Data on growth parameters and yield of okra... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Finite; Modelling; Growth; Yield; Okra; Tillage Systems; Soil. |
| Ano: 2022 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/7067 |
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| Nimmermark, Sven. |
| In regions with a colder climate the use of heat energy for climatization of greenhouses can be significant. Beside outdoor temperatures and climate also transpiration affects the use of heat energy since heating and ventilation or dehumidification may be required in order to keep the humidity in the greenhouse below levels which may lead to plant diseases. A reliable model is a powerful tool to predict energy use for greenhouse cultivation. Thus, a mechanistic model including transpiration and energy use for dehumidification and hourly output data was developed from an older simpler model. To be reliable, modelled data must fit with real data. The aim of the present study is to compare measured and modelled use of heat energy. Thus, energy use for a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Greenhouses; Energy; Measurements; Modelling. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3100 |
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| Arcidiacono, Claudia. |
| Heat stress in animal housing is one of the drivers affecting animal productivity and welfare in hot climates, and causing consequent reduced profits for the farmers. The main challenges that livestock breeding faces in hot climates regards how to foster, improve, and assess methods and strategies for animal heat stress abatement. Research studies in this field have generally proposed modifications in herd management and in feeding strategies, breed selection, and engineered solutions aimed at exploiting heat transmission phenomena. In this paper, the most recent engineered solutions for animal heat stress abatement in livestock buildings have been reviewed and described; they have involved new building and ventilation design and modelling, and improved... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rural buildings livestock buildings; Design; Modelling; Ventilation; Hot climate. |
| Ano: 2018 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4705 |
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| Nkakini, Silas Ovua; Douglas, I. E.. |
| In this study, a comparative evaluation of tractive force models for disc harrowing, at different tillage speeds was carried out in order to determine optimal tillage speeds. The predictive models were developed using dimensional analysis. The tillage operation in a loamy sand soil, at tillage speeds of 1.94 m s-1, 2.22 m s-1 and 2.5 m s-1 respectively was conducted, using trace tractor techniques. Parameters such as drawbar pull, rolling resistance, wheel slip, moisture content, cone index, wheel numeric, contact pressure, speed, width of harrow, depth of harrow, and tractive force were measured. The developed mathematical models describing the tractors tyre-soil interactions parameters were evaluated using sensitivity analysis of the measured... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Predictive; Tractive force; Disc harrowing; Tillage; Loamy; Sand; Soil; Modelling; Sensitivity measurement; Soil moisture.. |
| Ano: 2013 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2374 |
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| Sayago,S; Bocco,M. |
| Development of models for crop yield prediction using remote sensing allows accurate, reliable and timely estimations over large areas. Particularly, this information is necessary to ensure the adequacy of a nation's food supply as well as to aid policy makers and farmers. In Argentina, soybean (Glycine max (L.) Merr.) and corn (Zea mays L.) are the most important crops. The goal of this research was to develop and evaluate linear and non-linear models to estimate crop yield from satellite data. Particularly, we proposed and applied those models to obtain soybean and corn yield in the central region of Córdoba (Argentina) using Landsat and SPOT images. The models were designed taking into account all or some bands included in the images from one or both... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neural networks; Multiple linear regression; Soybean; Corn; Modelling. |
| Ano: 2018 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1668-298X2018000100001 |
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| YILMAZ,BURCIN; CAKMAK,HULYA; TAVMAN,SEBNEM. |
| Abstract: In this study effects of ultrasonic pretreatment with different sonication sources on drying behavior of carrot slices were evaluated. Fresh carrot slices were pretreated with ultrasonic probe at 65, 75 and 85 W or ultrasonic bath at 10, 20 and 30°C for 3, 5 and 10 min before air drying. Water gain % and solid loss % of pretreated samples were calculated and color values, β-carotene content and rehydration ratios of dried samples were determined. Drying behavior of the pretreated samples was evaluated and the drying data were fitted to thin layer drying models. Constant drying rate period was not observed for the carrot slices; however two definite falling-rate periods having different slopes were obtained. Drying time was significantly reduced... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carrot; Ultrasound; Β-carotene; Rehydration; Modelling. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000500905 |
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| OLIVEIRA,LAIO Z.; KLITZKE,ALINE R.; FANTINI,ALFREDO C.; ULLER,HEITOR F.; CORREIA,JEAN; VIBRANS,ALEXANDER C.. |
| Abstract The majority of Atlantic Forest fragments in Southern Brazil are second-growth forests dominated by fast-growing species with considerable market-value timber. Nevertheless, volume prediction models are scarce, especially to estimate tree total volume (i.e., stem plus branches). This study approached the issue through the following aims: to fit and select stem and total volume models (generic and species-specific) using data from 288 harvested trees in a management operation, and to fit generic and species-specific bark factors. The power model embedding diameter at breast height (D) and tree stem or total height (H) presented the greatest prediction strength for both stem and total tree volume. Models including only D to predict total tree volume... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Forest inventory; Mata Atlântica; Modelling; Regression. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000703729 |
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| Pereira,André Belmont; Villa Nova,Nilson Augusto; Ramos,Valdir Josué; Pereira,Antonio Roberto. |
| There is currently a great deal of interest in estimating crop productivity as a function of climatic elements by means of different crop weather models. An agrometeorological model is presented based on carbon dioxide assimilation maximum rates for C3 plants, fraction of photosynthetically active radiation, air temperature, photoperiod duration, and crop parameters under tropical climate conditions. Such crop parameters include leaf area and harvest indexes, dry matter content of potato tubers, and crop cycles to estimate potato potential yields. Field data from observed productivity obtained with the cultivar Itararé (IAC-5986), grown under adequate soil water supply conditions at four different regions in the State of São Paulo (Itararé, Piracicaba,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Modelling; Solanum tuberosum L.; Climatic elements; Crop indexes; Yield. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052008000200008 |
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| Registros recuperados: 153 | |
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