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| Alves,Guilherme E.; Borém,Flávio M.; Andrade,Ednilton T.; Isquierdo,Éder P.; Siqueira,Valdiney C.; Dias,Camila de A.. |
| ABSTRACT This study aimed to evaluate drying kinetics for natural and pulped coffee, using different temperatures and drying airflows. For the conduction of the experiment, coffee fruits (Coffea arabica L. cv. Topázio) were harvested manually, selecting only ripe fruits and subsequent to the hydraulic separation. For drying the coffee, use a mechanical dryer with two temperatures (40 and 45°C) and four drying air streams (24; 60; 96 and 132 m3.min-1.m-2). Twelve models for employees to describe the drying kinetics of coffees. Among the models used to describe the drying process of natural coffee and pulped coffee, according to the results of the coefficient of determination, relative mean error, standard deviation of estimates and distribution of waste... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffea arabica L.; Mathematical modeling; Drying rate. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200192 |
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| Silva,Fernanda P. Da; Siqueira,Valdiney C.; Quinzani,Guilherme A.; Martins,Elton A. S.; Goneli,André L. D.. |
| ABSTRACT: The objectives of this study were to describe the process of drying niger seeds through the fitting of different mathematical models to the experimental drying data, to select the best model that represents the phenomenon, and to determine the diffusion coefficients and thermodynamic properties of the product. Seeds with an initial moisture content of 0.42 (d.b) were collected and dried at 40°, 50°, 60°, 70°, and 80°C in a fixed bed experimental dryer. After drying, different mathematical models were fitted to determine the diffusion coefficient by applying liquid diffusion theory, which allowed for calculation of the energy activation, enthalpy, entropy, and Gibbs free energy values. The Page model was selected to represent the drying process of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Activation energy; Effective diffusion coefficient; Guizotia abyssinica Cass; Mathematical models. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000400727 |
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| Isquierdo,Eder P.; Caldeira,Daniela S. A.; Siqueira,Valdiney C.; Martins,Elton A. S.; Quequeto,Wellytton D.. |
| ABSTRACT This study aimed to obtain and evaluate thermodynamic properties and hygroscopic equilibrium isotherms of urunday seeds as a function of air relative humidity and temperature, as well as identify the best-fitted mathematical models for adsorption phenomenon. A static-gravimetric method was used to obtain hygroscopic equilibrium moisture content. Seeds were placed in airtight containers with different saturated saline solutions for relative humidity control. These were then kept in BOD incubator chambers at 10, 20, 30, and 40 °C. Hygroscopic equilibrium moisture content decreased as temperature increased, for the same water activity. The Sigma-Copace model best-fitted seed adsorption data for equilibrium water activity intervals between 0.1129 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water activity; Isokinetic; Sorption isotherms; Myracrodruon urundeuva; Relative humidity. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000300374 |
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| Quequeto,Wellytton D.; Siqueira,Valdiney C.; Schoeninger,Vanderleia; Martins,Elton A. S.; Isquierdo,Eder P.; Silva,Fernanda P. da. |
| ABSTRACT Buckwheat is a prominent crop in present-day agriculture due to its nutraceutical properties; however, information on this crop regarding the post-harvest process is scarce, as well as the characterization of its physical properties and such information is essential for the development and improvement of machinery used in post-harvest processes. Thus, the objective of this study was to determine the volumetric shrinkage, porosity, bulk density and true density of buckwheat grains throughout the drying process, as well as to fit mathematical models to the experimental values of true and bulk volumetric shrinkages. Buckwheat grains of the cultivar IPR 91 - Baili with an initial moisture content of 0.250 (decimal, dry basis.) were used. The samples... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Post-harvest; Moisture content; Volumetric shrinkage. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018001100793 |
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| Martins,Elton A. S.; Goneli,André L. D.; Hartmann Filho,Cesar P.; Mauad,Munir; Siqueira,Valdiney C.; Gonçalves,Alexandre A.. |
| ABSTRACT Safflower is an oil crop and its oil can be used for food and industrial purposes. However, there is little information about the physical properties of these grains, which is important for the planning and execution of post-harvest stages. Thus, this study was carried out with the aim of evaluating the effect of drying on the main physical properties of safflower grains. Safflower grains were harvested with an initial moisture content of approximately 0.445 decimal d.b. (dry basis) and subjected to drying in an oven with forced air circulation at 40 °C, until the grains reached a final moisture content of 0.073 ± 0.008 decimal d.b. During the drying, bulk density and true density, porosity, thousand-grain mass, circularity, sphericity, projected... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carthamus tinctorius L.; Bulk density; Shape of grains. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000500344 |
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| Siqueira,Valdiney C.; Resende,Osvaldo; Chaves,Tarcísio H.; Soares,Frederico A. L.. |
| Com base na necessidade de combustíveis que substituam o petróleo, do destaque do pinhão-manso na produção de biodiesel e da necessidade de construção e aperfeiçoamento dos equipamentos utilizados nas fases de colheita e pós-colheita desta cultura objetivou-se, com o presente trabalho, determinar a forma e o tamanho dos frutos de pinhão-manso durante a secagem em cinco condições de ar. Os frutos colhidos manualmente com o teor de água de 4,40 (kg de água por kg de matéria seca) foram submetidos a secagem em estufa com circulação de ar forçada em cinco condições de temperatura, 45, 60, 75, 90 e 105 °C, e umidades relativas de 14,5; 7,4; 3,8; 2,2 e 1,4%, respectivamente, até atingir teor de água de 0,10 ± 0,007 (kg kg-1 de matéria seca). Foram determinados... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodiesel; Pós-colheita; Jatropha curcas L.; Teor de água. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662012000800008 |
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| Silva,Fernanda P. da; Siqueira,Valdiney C.; Martins,Elton A. S.; Miranda,Fábio M. N.; Melo,Rogerio M.. |
| ABSTRACT The aim of this study was to determine the effective diffusion coefficient and the thermodynamic properties of Bauhinia forficata Link leaves, considering two forms of thickness measurements and to describe the process by fitting mathematical models. The leaves were collected, taken to the laboratory and prepared to start the drying process in which four temperatures (40, 50, 60 and 70 °C) were applied. After the drying process, the effective diffusion coefficient was determined through the theory of diffusion in liquid, allowing to obtain the values of the activation energy, enthalpy, entropy and Gibbs free energy. The description of the drying process was performed by setting the thirteen mathematical models used to represent constant drying of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Medicinal plants; Effective diffusion coefficient; Temperature. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000100061 |
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| Martins,Elton A. S.; Goneli,André L. D.; Goncalves,Alexandre A.; Hartmann Filho,Cesar P.; Siqueira,Valdiney C.; Oba,Guilherme C.. |
| ABSTRACT Blackberry leaves have some pharmacological properties and one of the most widespread and studied uses is to relieve symptoms of the climacteric and other symptoms during the premenstrual period. Thus, drying becomes important for the conservation and storage of the product until its use or processing. The present study aimed to evaluate the drying kinetics of blackberry leaves, as well as to determine the effective diffusion coefficient and the activation energy during the drying process. Blackberry leaves were dried in an experimental fixed-bed dryer under four controlled temperature conditions (40, 50, 60 and 70 °C) and two drying air speeds (0.4 and 0.8 m s-1). With the experimental data of moisture ratio, eight mathematical models were fitted... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Morus nigra L.; Medicinal plant; Air speeds; Midilli model. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000800570 |
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