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| Registros recuperados: 223 | |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| Registros recuperados: 223 | |
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