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https://purl.org/pe-repo/ocde/ford#4.04.01 6 Mass transfer 5 https://purl.org/pe-repo/ocde/ford#2.11.01 5 https://purl.org/pe-repo/ocde/ford#2.11.00 4 Cylinders (shapes) 3 Deshidratación de alimentos 3 Drying 3 más ...
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The authors are grateful to the São Paulo Research Foundation (FAPESP, Brazil) for funding the project nº 2016/18052-5; to the National Council for Scientific and Technological Development (CNPq, Brazil) for funding the project nº 401004/2014-7; and to Cienciactiva for the M.L. Rojas Ph.D. scholarship (CONCYTEC, Peru; Contract 087-2016-FONDECYT), from the ‘‘Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica”. The authors are also grateful to the “Laboratório de Análise de Imagens” (LPV-ESALQ/USP) for the support and facilities for X-ray analysis.
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Original abstract: We explore the small-scale spatial and temporal transferability of model parameters between two points in the ablation zone of tropical Glaciar Shallap, Cordillera Blanca, Peru (9°S, -77° W; ~4800 m a.s.l.) in order to provide a robust assessment of the performance of a process-based glacier mass-balance model. Relative surface height change is calculated at hourly time-steps, and cumulative values are compared to surface height measurements made at irregular intervals (14–64 days) over the course of two continuous hydrological years (August 2006–August 2008). Best-performing parameter combinations were determined for each point from the outcome of 1000 model simulations for which parameters were varied randomly within a defined range. With these parameter combinations measurements for a specific location and time-span are well reproduced. Transferring the parame...
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPN por restricciones de la casa editorial donde ha sido publicado.
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This work aimed to evaluate how cut orientation affects mass transfer during the drying and rehydration process. Sweet potato cylinders of 1.90 cm of diameter and 0.50 cm of height were prepared. Three cut orientations were carried out regarding the vascular tissue orientation, preparing longitudinal, transverse and oblique (45°) cuts. In addition, osmotic pretreatment (50°Brix sucrose solution) was also evaluated. Convective drying and rehydration kinetics were evaluated at a constant temperature. As results, cut orientation and osmotic pretreatment did not affect the drying kinetics. However, transverse cut without osmotic pretreatment presented less shrinkage than the other cut orientations. On the other hand, rehydration process was affected by cut orientation, being longitudinal cut the slowest sample absorbing water. In conclusion, both the cut orientation and osmotic dehydra...
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objeto de conferencia
ABSTRACT This study evaluated the osmotic dehydration (OD) treatments (using sucrose at 60 °Brix and a solution of salt 1.5% (m/m) with sucrose at 45 °Brix) in banana slices. The effects on the mass transfer kinetics (water loss and solids gain) were evaluated and described using the Page, Weibull, Peleg, Azuara, and Lewis mathematical models. Besides, the effect of OD on fat content, instrumental colour, and sensorial attributes was assessed after the frying process. The results showed that water loss occurs firstly and more quickly than solids gain. At the end of OD, the highest water loses (0.31 g water/g sample) and solids gain (0.42 g solid/g sample) were reached using sucrose OD treatment. The water loss and solid gain behaviour were described not only by the kinetics parameters but also by equilibrium parameters values of mathematical models. Furthermore, after frying, the Contr...
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Consejo Nacional de Ciencia, Tecnología e Inovación Tecnológica. Grant Number: Contract 272-2015-FONDECYT
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The phenomenon of mass transfer during osmotic dehydration and convective drying of tomato halves (Solanum lycopersicum L.) was carried out 1) using sucrose and salt as solutes; and 2) by fitting the Peleg and Page equations to the experimental data. The fruit was cut into halves and its seeds and placenta were removed. It was osmotically dehydrated with solutions: 10.8% 18% and 30% 50%, (w/v), of salt and sucrose respectively at a temperature of 25 °C. Subsequently, the resulting samples were subjected to a convective drying process by forced air in a tunnel at temperatures of: 50; 70 and 90ºC. Determining the weight loss of the samples, the solids gain, obtaining parameters from the experimental models of Peleg and Page with correlation levels of R2 ≥0.9894 for the proposed models.
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tesis de grado
El arándano es un producto que posee niveles altos de antioxidantes y tiene muchos beneficios saludables. El aumento de la pérdida de peso del producto de la fruta, se observa en los diferentes puntos de una cámara frigorífica, lo que conduce al deterioro de la calidad y seguridad de la fruta. El objetivo de este estudio fue una simulación de la perdida de humedad (transferencia de masa) de los arándanos durante el almacenamiento y transporte en frio (10C y HR 75% – 82 %). El modelamiento matemático y simulación han sido codificados utilizando la plataforma de programación MATLAB versión R2017-b. Los resultados mostraron una buena concordancia entre los resultados simulados y medidos, fueron validados los datos de la pérdida de peso (humedad), con datos proporcionados de la industria de procesamiento y almacenamiento en cámaras de refrigeración y transporte tanto en vía a...
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The authors are grateful to the São Paulo Research Foundation (FAPESP, Brazil) for funding the project n° 2016/18052-5; the National Council for Scientific and Technological Development (CNPq, Brazil) for funding the project n° 401004/2014-7 and the productivity grant of P.E.D. Augusto (306557/2017-7); Cienciactiva from the ‘‘Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica“ (CONCYTEC, Peru) for the A.C. Miano (Contract 272-2015-FONDECYT) and M.L.Rojas (Contract 087-2016-FONDECYT) Ph.D. scholarships.
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In the present work the revision, deduction and application of mathematical models in the quantification of the reaction kinetics of leaching processes of national sulphided minerals in chemical systems is made. The interaction between the mineral particles and the leaching solution is controlled by three possible mechanisms: by chemical reaction, by diffusion through the porous bed and by mass transfer; Each mechanism has its own mathematical modeling and parametric conditions. Experimental runs of leaching of gold and copper minerals are presented, in which their kinetic control equations of the most relevant variables are shown. Other empirical models are also shown that are used to elucidate the phenomenology of the leaching of mineral species, call chalcopyrite, sphalerite and galena.
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In the present work the revision, deduction and application of mathematical models in the quantification of the reaction kinetics of leaching processes of national sulphided minerals in chemical systems is made. The interaction between the mineral particles and the leaching solution is controlled by three possible mechanisms: by chemical reaction, by diffusion through the porous bed and by mass transfer; Each mechanism has its own mathematical modeling and parametric conditions. Experimental runs of leaching of gold and copper minerals are presented, in which their kinetic control equations of the most relevant variables are shown. Other empirical models are also shown that are used to elucidate the phenomenology of the leaching of mineral species, call chalcopyrite, sphalerite and galena.
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This work was supported by the São Paulo Research Foundation (FAPESP, Brazil) [grant numbers 2014/16998-3 (project), 2014/26433-3 (JC Pereira B.Sc. scholarship)]; the National Council for Scientific and Technological Development (CNPq, Brazil) [grant number 401004/2014-7 (project) and B Miatelo B.Sc. scholarship (PIBIC)]; and the “Consejo Nacional de Ciencia, Tecnología e Inovación Tecnológica” (CONCYTEC, Perú) [grant number 272-2015-FONDECYT (A.C. Miano Ph.D. scholarship)].
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The authors are grateful to the Sao Paulo Research Foundation (FAPESP, Brazil) for funding the project n? 2019/05043-6; this study was financed in part by the ?Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - Brazil (CAPES)? ? for the JS Guedes (88882.378356/2019-01) and KC Santos (88882.378385/2019-01) M.Sc. scholarships; to the National Council for Scientific and Technological Development (CNPq, Brazil) for the JS Guedes M.Sc. scholarship (131235/2020-6) and the productivity grant of PED Augusto (306557/2017-7); and to the Fondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica (FONDECYT, Peru) from the ?Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica? (CONCYTEC, Peru) for funding the project n° 409-2019-FONDECYT.
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Polyribosyl-ribitol-phosphate (PRP) from Haemophilus influenzae type b (Hib) is an active immunizing molecule used in the production of the vaccine against H. influenzae, and industrial production could contribute to satisfying a world demand especially in developing countries. In this sense, the aim of this study was to establish a scale-up process using the constant oxygen mass transfer coefficient (kLa) such as the criterion for production of PRP in three different sizes of bioreactor systems. Three different kLa values (24, 52 and 80 h−1) were evaluated in which the biological influence in a 1.5 L bioreactor and 52 h−1 was selected to scale-up the production process until a 75 L pilot-scale bioreactor was achieved. Finally, the fed-batch phase was started under a dissolved oxygen concentration (pO2) at 30% of the saturation in the 75 L bioreactor to avoid oxygen limitation; the p...
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Polyribosyl-ribitol-phosphate (PRP) from Haemophilus influenzae type b (Hib) is an active immunizing molecule used in the production of the vaccine against H. influenzae, and industrial production could contribute to satisfying a world demand especially in developing countries. In this sense, the aim of this study was to establish a scale-up process using the constant oxygen mass transfer coefficient (kLa) such as the criterion for production of PRP in three different sizes of bioreactor systems. Three different kLa values (24, 52 and 80 h−1) were evaluated in which the biological influence in a 1.5 L bioreactor and 52 h−1 was selected to scale-up the production process until a 75 L pilot-scale bioreactor was achieved. Finally, the fed-batch phase was started under a dissolved oxygen concentration (pO2) at 30% of the saturation in the 75 L bioreactor to avoid oxygen limitation; the p...
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Different drying accelerators were studied to improve vegetable drying: acetone (AC), ethanol (ET), isopropanol (ISO) and acetic acid (AA). Pre-treatments were performed by immersion of pumpkin cylinders. Convective drying was performed at 40 degrees C and air velocity 1 m/s. Different aspects were evaluated: drying kinetics, structural changes (microstructure and macrostructure), thermal profile and viscoelastic and rehydration behaviours. The microstructure was modified by pre-treatments, being more pronounced with AC and AA. Thinner cell walls, changes on turgor and extraction of components and air were reported, affecting the mass transfer. Moreover, the microstructural changes reinforced anisotropy and also affected the macrostructure, changing the viscoelastic behaviour. All pre-treatments resulted in a super-diffusive behaviour, decreasing the drying time from 9% (ISO) to 22% (AC)...
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ABSTRACT Different drying accelerators were studied to improve vegetable drying: acetone (AC), ethanol (ET), isopropanol (ISO) and acetic acid (AA). Pre-treatments were performed by immersion of pumpkin cylinders. Convective drying was performed at 40 °C and air velocity 1 m/s. Different aspects were evaluated: drying kinetics, structural changes (microstructure and macrostructure), thermal profile and viscoelastic and rehydration behaviours. The microstructure was modified by pre-treatments, being more pronounced with AC and AA. Thinner cell walls, changes on turgor and extraction of components and air were reported, affecting the mass transfer. Moreover, the microstructural changes reinforced anisotropy and also affected the macrostructure, changing the viscoelastic behaviour. All pre-treatments resulted in a super-diffusive behaviour, decreasing the drying time from 9% (ISO) to 22% (...
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tesis de grado
Este trabajo de suficiencia profesional está basado en una propuesta de mejora para aumentar el nivel de servicio en una empresa del sector de consumo masivo. Se obtuvo la data necesaria para analizar los principales motivos los cuales fueron la rotura de stock y el error en el pronóstico de ventas. Mediante la investigación de técnicas, herramientas y metodologías se planteó el modelo de mejora. Se seleccionaron cuatro skus de la categoría de cereales, los cuales presentaron mayor venta dentro del universo de productos para plasmar los resultados de la implementación. A través de la gestión por procesos, se mejoró el tiempo de traslado de mercadería entre la planta productiva hacia los almacenes, y se logró llegar al objetivo del indicador de eficacia de traslados (98%). Con el método de inventario EOQ, se obtuvo mejoras en la disponibilidad de stock, el cual se ve refleja...
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The authors are grateful to the S?o Paulo Research foundation (FAPESP, Brazil): projects n? 2014/12606-3 and 2019/05043-6; GR Carvalho post-doctoral fellowship (2018/17844-0); the ?Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior?Brasil (CAPES)?: BO Gomes (88887.485030/2020-00), JS Guedes (88887.513566/2020-00) and KC Santos (88882.378385/2019-01) M.Sc. and Ph.D. Scholarships; the National Council for Scientific and Technological Development (CNPq, Brazil): BS Bitencourt (132297/2019-1) M.Sc. Scholarship and PED Augusto productivity grant (310839/2020-3); the Fondo Nacional de Desarrollo Cient?fico, Tecnol?gico y de Innovaci?n Tecnol?gica (FONDECYT, Peru) from the ?Consejo Nacional de Ciencia, Tecnolog?a e Innovaci?n Tecnol?gica? (CONCYTEC, Peru): project n? 409-2019-FONDECYT; the Universidad Privada del Norte (UPN, Peru): project n? 20201005. The authors are also grateful for...
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The authors are grateful to the São Paulo Research Foundation (FAPESP, Brazil) for funding the project no. 2014/16998-3 and JC Pereira B.Sc. scholarship (2014/26433-3); the National Council for Scientific and Technological Development (CNPq, Brazil) for funding the project no. 401004/2014-7 and MD Matta Jr. post-doctoral fellowship (158545/2015-0); Cienciactiva for the A.C. Miano Ph.D. scholarship, from the “Consejo Nacional de Ciencia, Tecnología e Inovación Tecnológica” (CONCYTEC, Peru; Contract 272-2015-FONDECYT) and Coordination for the Improvement of Higher Education Personnel (CAPES, Brazil) for the N Castanha M.Sc. scholarship. The authors are also grateful to the “Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária” (NAP/MEPA-ESALQ/USP) for the support and facilities of Electronic Microscopy. By describing an important process fo...