Diffusion Models
Mostrando 1-12 de 324 artigos, teses e dissertações.
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1. A Nodal-iterative Technique for Criticality Calculations in Multigroup Neutron Diffusion Models
ABSTRACT In this work, a nodal and iterative technique to evaluate the effective multiplication factor as well as the neutron flux, in multigroup diffusion problems, is presented. An iterative scheme, similar to the source iteration method, is implemented to decouple the system of differential equations which is the fundamental mathematical model. Then, anal
Trends in Computational and Applied Mathematics. Publicado em: 2022
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2. Mathematical Modeling of the Film Influence on the Salting Time of Mozzarella Cheese in a Static and Dynamic System: Application of Artificial Neural Networks of the Multilayer Perceptron Type
The NaCl and KCl diffusion in the film formed on the cheese surface during salting was simulated by the finite element method. The time and salts concentration values on the cheese surface were determined, tabulated, and presented to the multilayer perceptron neural network (MLP) for the regression modeling. The samples were divided into 70, 15 and 15% for t
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. THE INFLUENCE OF THE FILM FORMED ON THE PRATO CHEESE SURFACE DURING THE NACL AND KCL SALTING PROCESS: APPLICATION OF THE FINITE ELEMENT METHOD AND NEURAL NETWORKS OF THE SELF-ORGANIZING MAP (SOM) AND MULTILAYER PERCEPTRON (MLP) TYPES
Sodium chloride is used in the cheese salting process as it promotes sensory changes and food preservation. However, in excess can cause hypertension problems, and for this reason, it has been partially replaced by potassium chloride. In the present work, Prato cheese was subjected to joint diffusion of NaCl and KCl by immersion in static and stirred brine.
Química Nova. Publicado em: 2022
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4. Mathematical modeling of whey foam mat drying
ABSTRACT This study aimed to fit mathematical models to whey foam drying processes in different air temperature conditions, to determine the effective diffusion coefficient and to obtain the activation energy. For foam formation, 5.0% Emustab® was added to the serum in mass and subjected to stirring in a domestic shaker for 15 min. After, it was spread onto
Rev. Ceres. Publicado em: 2021-08
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5. Application of artificial neural networks in the study of Mozzarella cheese salting
Abstract A highly efficient tool that has stood out in data processing and treatment is Artificial Neural Networks (ANNs). Self-organized maps (SOM), which is a type of ANNs, are easy-to-view computational models that simulate information processing and knowledge acquisition. Applying this tool, we analyzed the behavior of the film formed on the mozzarella c
Food Sci. Technol. Publicado em: 2021-06
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6. REHYDRATION KINETICS OF DEHYDRATED BERRIES
ABSTRACT Cranberries and blueberries are small fruits known for their antioxidant properties. However, due to their high water content and short shelf life, they are generally marketed as dehydrated berries. The present work aimed to model the rehydration of dehydrated berries. Rehydration tests were conducted at 7 and 29°C using milk as a solvent and at 7,
Eng. Agríc.. Publicado em: 2021-05
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7. Investigation of ultrasound pretreatment time and microwave power level on drying and rehydration kinetics of green olives
Abstract In this study, the effect of ultrasound (US) combined microwave (MW) drying of green olive slices was studied. Olive samples were exposed to ultrasound (5 and 10 minutes; 32 KHz) at room temperature before dried at microwave at 3 different power level (180W, 450 W and 800 W). The drying and rehydration characteristics and quality parameters of olive
Food Sci. Technol. Publicado em: 2021-03
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8. Recent Developments on the Elucidation of Colloidal Aspects of Asphaltenes and Their Relevance to Oilfield Problems
Asphaltenes constitute the heavy petroleum fraction responsible for deposition events that may lead to reduced oil production, therefore of great interest for flow assurance. These molecules self-assemble in solutions leading to formation of aggregates that eventually grow towards precipitation and blockages in reservoirs and pipelines. Based on the Yen-Mull
J. Braz. Chem. Soc.. Publicado em: 2020-02
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9. DETERMINATION OF REACTIVITY AND THERMODYNAMIC ANALYSIS OF NICKEL-BASED OXYGEN CARRIERS FOR CHEMICAL-LOOPING COMBUSTION
Abstract This work aimed to study nickel-based oxygen carriers (OC) for Chemical Looping Combustion (CLC) using H2 and CH4 as fuel. The reactivity and reaction kinetics of the OC were investigated, applying the shrinking core, nucleation and diffusion models in three dimensions, as well as whether the OC is thermodynamically favorable for the reaction. The r
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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10. Aplicação de solução semianalítica para modelagem de ensaios de sorção e difusão pura com lixiviado
RESUMO A implementação da Política Nacional de Resíduos Sólidos (Lei nº 12.305, de 2 de agosto de 2010) foi um marco para a disposição final e o tratamento de resíduos sólidos no país. A contaminação decorrente da negligência na disposição dos resíduos sólidos urbanos atinge sistemas naturais vitais para a existência humana. Torna-se, port
Eng. Sanit. Ambient.. Publicado em: 25/11/2019
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11. Cinética de secagem e propriedades termodinâmicas da polpa de patauá (Oenocarpus bataua Mart.)
Resumo O patauá é uma fruta amazônica que, devido às suas propriedades sensoriais e nutricionais atrativas, tem despertado o interesse da comunidade científica. Entretanto, o elevado conteúdo de umidade confere alta perecibilidade ao produto fresco. Assim, objetivou-se estudar a cinética de secagem convectiva e determinar as propriedades termodinâmic
Braz. J. Food Technol.. Publicado em: 25/11/2019
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12. Drying kinetics and mass transfer properties in the drying of thistle flower
Resumo A flor de cardo e, em particular, os seus estigmas, são utilizados para coagular o leite na produção de vários queijos tradicionais portugueses, devido à sua elevada atividade de coagulação, proporcionada pelo elevado teor de proteases aspárticas. O objetivo do presente trabalho foi determinar as propriedades de transferência de massa da seca
Braz. J. Food Technol.. Publicado em: 24/10/2019