Adriano da Silva - Academia.edu (original) (raw)

Papers by Adriano da Silva

Numerical Heat Transfer, Part A: Applications, 2010

This article presents an investigation into natural convection in trapezoidal cavities. It examin... more This article presents an investigation into natural convection in trapezoidal cavities. It examines a cavity whose floor and upper inclined walls are both adiabatic, while the vertical walls are isothermal. For these isothermal walls, we consider two thermal boundary conditions. Under the first condition, the short wall on the left side is heated as the tall one on the right side is cooled. The second condition is the reverse of the first-the short wall is cooled as the tall one is heated. Considering laminar conditions and a twodimensional system, steady-state computations are carried out to assess the effects of one and two baffles, the baffle's height (H b), Rayleigh number, 10 3 Ra 10 6 , and three Prandtl number values. To demonstrate the various effects, the results from several designed case studies are shown in terms of isotherms, streamlines, and local and average Nusselt numbers in order. Predictions reveal that the second baffle decreases the cavity's fluid flow and heat transfer. As the height of the baffle rises, the heat transfer drops drastically. Also, two baffles produce more pronounced thermal stratification than only one.

Journal of Water Process Engineering, 2019

The BTEX compounds have potential pollution with serious risk to the environment and human health... more The BTEX compounds have potential pollution with serious risk to the environment and human health. In this study, batch and continuous bioreactors, using biofilms supported on activated carbon particles were studied to remove BTEX compounds. The activated sludge from local wastewater treatment plant was adapted to biodegrade BTEX compounds and used in this work. The obtained results showed that the biofilm well adapted with the evaluated conditions and was able to conduct a complete degradation of BTEX compounds. Additionally, particles samples demonstrated higher bacteria content ranging from 79.40 (toluene) to 8.84 mg vss /L (o-xylene) of biomass amount. Kinetic parameters were obtained in a batch bioreactor fed daily with BTEX compounds. The tests showed that the biomass in the bioreactor was able to remove the BTEX compounds up to 300 min showing a potential strategy for the petrochemical industry. In addition, compared to the initial toxicity, after the treatment, a reduction in the acute toxicity up to 99% was observed confirm the potentiality of the proposed system in this study.

International Journal of Heat and Mass Transfer, 1987

Natural convection flow and heat transfer in a narrow vertical annulus located centrally above a ... more Natural convection flow and heat transfer in a narrow vertical annulus located centrally above a reservoir has been studied. The fluid in the reservoir is heated up by a hot, isothermal bottom end wall. The flow characteristics has been analysed by observing flow topologies and contours of temperature. Results are presented for Rayleigh numbers in the interval [2000-20000]. The flow consist of steady, periodic and quasi periodic regimes. The stream trace plot in each case is found to contain correct number of singularities of different types, which is required for satisfying the Hunts criterion. The annulus geometry selected for the study is a simplified model of the narrow annulus of a typical nuclear reactor design. The variation of circumferential temperature obtained from the study provides a relevant data for the design of nuclear reactors and similar systems.

Journal of Contaminant Hydrology

Process Safety and Environmental Protection, 2022

Chemical Engineering Research and Design, 2021

Abstract Based on CFD’s simulations using RANS and SGDH (Standard Gradient Diffusion Hypothesis),... more Abstract Based on CFD’s simulations using RANS and SGDH (Standard Gradient Diffusion Hypothesis), this study presents an alternative to better predict turbulent catalytic systems with surface reaction limited by mass transfer selecting an optimal turbulent Schmidt number (Sct). Simulations of H2O2 degradation were performed in an annular reactor with Mn/Al oxide immobilized into the wall using the AKN, RSM and standard k-e turbulence models with the Sct varying from 0.2 to 1.1. The numerical apparent reaction constant (kapp) was compared with literature data to verify the prediction errors. The ideal Sct was applied to simulate the benzoic acid photocatalytic degradation in photocatalytic reactor coated with TiO2 for different flow rates. The results showed that the Sct of 0.8 for AKN, 0.7 for RSM, and 0.2 for standard k-e are the best for systems with high mass transfer limitations and the Sct of 1.1 for AKN, 1.0 for RSM, and 0.4 for standard k-e are the best for systems with low mass transfer limitations. It was concluded that all turbulence models predicted well the mass transfer when the ideal Sct was used and the standard-k-e model could be an alternative since the prediction error was less than 6.5% with low computational cost.

Neste trabalho e avaliado o potencial biocatalitico da lipase de Candida rugosa (LCR) imobilizada... more Neste trabalho e avaliado o potencial biocatalitico da lipase de Candida rugosa (LCR) imobilizada em diferentes suportes: carvao ativado, gesso comercial e silica gel, visando a producao de biodiesel. O metodo de imobilizacao por adsorcao foi utilizado na imobilizacao da LCR nos suportes. A eficiencia de imobilizacao expressa em termos da razao entre a atividade do complexo suporte-LCR e atividade da enzima livre, foram estimados, fornecendo eficiencia de 89% para o carvao ativado-LCR, 62% para a silica gel-LCR e 48% para o gesso-LCR. O complexo carvao ativado-LCR forneceu o maior indice de acidez. A analise por cromatografia de camada delgada do biodiesel produzido por este complexo apresentou fatores de retencao e ordem de eluicao dos acilglicerois compativeis com a literatura, indicando um potencial deste complexo para a producao de biodiesel.

Journal of Petroleum Science and Engineering, 2022

Abstract One of the largest wastewater flows generated in the oil and gas industry is produced wa... more Abstract One of the largest wastewater flows generated in the oil and gas industry is produced water (PW), which can come from oil fields, gas fields or a combination of oil and gas fields. This effluent has a complex and variable chemical composition; it contains a significant amount, sometimes up to 500 mg L−1, of water soluble organic compounds (WSO) that are not easily removed by conventional physical-chemical treatment as coagulation and flotation. With the intensification in worldwide industrial activities, the generation of PW has consequently also increased and, from the environmental point of view, it is of fundamental importance to point out the alternatives for its proper management, in order to comply with legislation around the world and to provide safe subsequent destination (reuse and/or disposal). Furthermore, the treatment of this effluent is challenging and requires a lot of attention from both industry and academy. In this context, adsorption is known as one of the most effective technologies for removing WSO in polishing steps, since it is a technique of simple installation and maintenance, with low cost. Thus, this paper aims to review and highlight in detail (i) the main characteristics of produced water and its different forms of reuse, (ii) the theoretical fundaments of the adsorption technique and (iii) through case studies, critically evaluate the technical feasibility of implementing adsorption towers in PW treatment units.

Chemical Engineering Research and Design, 2021

Abstract A wide range of materials can be used for membrane production for wastewater treatment u... more Abstract A wide range of materials can be used for membrane production for wastewater treatment using membrane technology. Polymeric membranes have the disadvantage of high fouling tendency when used for oil-water wastewater, reducing the membrane flux. In this study, a simple superficial modification with polydopamine (PDA) coating was used, combined with the electrospinning technique to create an additional layer over the hydrophobic commercial polyvinylidene fluoride (PVDF) membrane, to achieve a hydrophilic surface and fouling resistance for oil-water separation. PVDF microfiltration membrane, with 0.22 μ m of pore size, was modified with PDA by deposition for 12 h. A layer of polyvinylpyrrolidone-co-polymethyl methacrylate (PVP-co-PMMA) was electrospun over the modified polydopamine membrane. The modified membrane showed a hydrophilic surface, with a higher clean water flux and a reduction of fouling during emulsion filtration, when compared with the commercial microfiltration PVDF membrane. So that a simple modification, forming a multilayer membrane, increased up to 4 times of clean water flux after the cleaning procedure of the membrane.

Journal of Cleaner Production, 2020

B.F. Skinner developed the operant laboratory using electromechanical technology available in the... more B.F. Skinner developed the operant laboratory using electromechanical technology available in the 1930s. Since then, electronics and digital computers have changed the way in which events are recorded, and experiments programed and controlled. However, the essential features of the operant preparation (a set of instruments, concepts, and procedures seamlessly integrated to reliably render samples of operant behavior) have remained for the most part intact. Years of accumulated knowledge may be necessary to understand the extent of a model's capacity and limitations. In the case of the operant preparation, a number of important limitations to its original accepted validity have appeared over time, derived from new data and more inclusive theoretical frameworks. The aim of this paper is to examine the significance of the operant assay, and to consider potential extensions to incorporate dimensions of behavior made possible by new and emerging theories and technologies.

Brazilian Journal of Chemical Engineering, 2020

A two-dimensional process of dyeing yarn coils was modelled in COMSOL Multiphysics to evaluate th... more A two-dimensional process of dyeing yarn coils was modelled in COMSOL Multiphysics to evaluate the dyeing characteristics according to a pilot-scale process. The proposed mathematical model was able to reproduce the experimental data and great importance was identified for the dyebath flow through the axial exit of the coil in relation to the radial outlet, about 2.8 times greater. To maintain the same flow, the permeability of the bobbin decreased tenfold between the radial and two-dimensional flow. Changes in the pressure gradient greatly influence the velocity field. The velocity and concentration fields found reinforce the preferential use of dyeing bobbins that do not have gaps between them, forcing the dyeing bath to follow the radial flow. Keyword Mathematical modelling • Permeability • Bobbin dyeing Abbreviations C ali Feed concentration in the inner bobbin radius (mol m −3) C i Dye concentration of the dyebath (mol m −3) C out Average dye concentration in the fluid phase of the bobbin (mol m −3) C p,j Dye conccentation in the solid phase (mol m −3) D h,j Hydrodynamic dispersion tensor (m 2 s −1) D e,j Effective diffusivity (m 2 s −1) P in Inlet pressure (Pa) P out Outlet pressure (Pa) V d Volume of dyeing bath (m 3) q p,j Adsorption isotherm (m 3 kg −1) Volume fraction of fluid phase (−) Volume fraction of solid phase (−) Specific mass of the fluid (kg m −3) Specific mass of the fiber (kg m −3) ∇ Differential operator (−) H Height of bobbin (m) Kl Langmuir constant (m 3 mol −1) Qmax Max adsorption (mol kg −1) Re External radius of bobbin (m) Ri Internal radius of bobbin (m) W Average weight of bobbin (kg) F Gravitational force (kg m −2 s −2) I Unit vector (−) P Presure (Pa) Q Volumetric flow rate of the dyeing bath (m 3 s −1) T Transposition operation (−) t Process time (s) u Velocity vector (m s −1) Viscous force coefficient (kg m −4) Permeability (m 2) Dynamic viscosity (kg m −1 s −1)

International Journal on Alive Engineering Education, 2017

Journal of hazardous materials, Jan 9, 2018

The aim of this work was to study the feasibility of textile sludge as a precursor to prepare cat... more The aim of this work was to study the feasibility of textile sludge as a precursor to prepare catalysts for catalytic wet peroxide oxidation (CWPO) by chemical and thermal treatments. Textile sludge was characterized by physical-chemical and metal composition analyses. The chemical activation was evaluated using iron sulfate and the thermal treatment was carried out at 720 °C in a vacuum pyrolysis reactor. Two catalysts with iron contents of 1.5% and 5.6% were selected. Process parameters influence on CWPO of phenol were evaluated and a maximum removal of phenol and TOC was observed at pH 3 and 60 °C, using 3 g L of the catalyst containing 5.6% of iron and 11.8 mmol L of HO. Metal analysis indicated that the textile sludge is suitable to be employed as both iron catalyst and adsorbent. The catalysts characterization indicated a reasonable surface area with a well-developed microporosity and the presence of Hematite structures in the carbonaceous matrix. The degradation process achie...

Brazilian Journal of Food Research, 2016

Brazilian sugar cane spirit (cachaça) production is traditional among rural producers in Santo An... more Brazilian sugar cane spirit (cachaça) production is traditional among rural producers in Santo Antônio da Patrulha-RS-Brazil. In this work, in similar conditions used by the producers, the effect of different °Brix and nutrients concentration on sugar cane juice fermentation time and ethanol yield was tested. Sixteen experiments were executed, predicted in a statistical planning, in order to identify the effect of eight factors. The results indicate that the increase on manganese sulfate concentration and cornmeal amount, and also the zinc sulfate concentration increase in interaction effect with higher °Brix, cause increase in fermentation time. It was also observed that the ethanol yield was higher at lower °Brix and at higher triple superphosphate amount in interaction effect with higher °Brix. Ammonium sulfate and copper sulfate concentrations, and also rice bran amount had no significant influence on the process. The best parameters determined, at local conditions, to obtain th...

Tese (doutorado) - Universidade Federal de Santa Catarina. Centro Tecnologico. Programa de Pos-Gr... more Tese (doutorado) - Universidade Federal de Santa Catarina. Centro Tecnologico. Programa de Pos-Graduacao em Engenharia Mecânica.

Informacion Tecnologica

Información Tecnologica, vol. 10, n. 2, pp.67-72, ISSN 0716-8756, Março/1999.

Application of Biofilm in the Degradation of Contaminants in Industrial Effluents, Chapter 10 of ... more Application of Biofilm in the Degradation of Contaminants in Industrial Effluents, Chapter 10 of Book: Biofilms: Formation, Development and Properties, Editor: William C. Bailey, ISBN: 978-1-61728-293-5, Nova Science Publishers, Inc., NY, USA, 2011.

International Journal of Heat and Mass Transfer, 2015

Journal of Food Process Engineering, 2014

ABSTRACT The kinetics of the hot-air drying of soybeans was modeled in order to evaluate the infl... more ABSTRACT The kinetics of the hot-air drying of soybeans was modeled in order to evaluate the influence of temperature and velocity on the kinetic parameters. A convective dryer with air temperature from 30 to 195C and air flows of 0.75, 1.35, 2.0 and 2.5 m/s was used. Three different mathematical models were applied to simulate the drying process (two empirical equations, exponential and Page's, and Fick's diffusion model) and the diffusivity coefficient increased from 2.5 × 10−11 to 6.69 × 10−10 m2/s for a range of air temperature between 30 and 195C. Both temperature and velocity influenced drying rate. The differential evolution optimization method was used toward parameter estimation. The goodness of fit of the proposed models, evaluated using linear regression coefficient (R2), chi-squared parameter (χ2) and root mean square error, indicated a satisfactory validation, mainly regarding to the exponential and Page's models.Practical ApplicationsAlthough biological materials are dried to improve shelf life, reduce packaging costs and enhance sensorial aspects, they are highly susceptible to quality deterioration during dehydration if the processing parameters are not well adjusted. The mathematical modeling of food drying provides results about the influence of process parameters on energy efficiency and final product quality in order to help the optimization and upscale application. Given that up to 40% of the agro-industrial production is lost in developing countries due to the lack of processing and that an energy efficiency improvement of 1% may result in 10% increase in profit, it is important to explore the potential of mathematical tools to properly study drying processes under an energy and qualitative approach.

Revista Brasileira de Pesquisa em Alimentos, 2012

Resumo: A produção de uma bebida fermento-destilada a partir da uva-Japão apresenta-se como uma b... more Resumo: A produção de uma bebida fermento-destilada a partir da uva-Japão apresenta-se como uma boa opção de complementação de renda para os pequenos produtores rurais. Os ensaios fermentativos foram conduzidos sob diferentes diluições de suco de uva-Japão (30 e 50%), diferentes temperaturas (30 e 35 °C), sem e com a adição de micronutrientes (fontes de K+, Mn++). As análises realizadas ao longo do processo fermentativo fazem referência à concentração de substrato (açúcar) e de células, com acompanhamento do pH e produção de etanol. De acordo com os dados obtidos, verificou-se um crescimento microbiano considerável para o teste com 2,5 g de fermento biológico, 30% de suco diluído em água a 30 °C e com adição de potássio como micronutriente, sugerindo que o mesmo é capaz de metabolizar os açúcares presentes no caldo, convertendo-o em biomassa e metabólitos secundários, mesmo em baixas concentrações. Desta forma, pode-se sugerir o uso da uva-Japão (Hoveniadulcis) como fonte de carbono e nutrientes para processos fermentativos utilizando-se cepas comerciais de Saccharomycescerevisiae, sob condições moderadas de operação, para a produção de etanol ou outros metabólitos com possível interesse comercial. Palavras-chave: Fermentação alcoólica. Uva-Japão (Hoveniadulcis). Destilação. Micronutrientes. Influence of nutrients addition in the fermentation kinetics of Japanese Grape juice by Saccharomyces SP. The production of a fermented distilled drink from Japanese grapeis presented as a good option of income complement to small farmers. The fermentative tests were conducted under different juice dilutions of Japanese grape (30 and 50%), different temperatures (30 and 35 °C), with and without the addition of micronutrients (sources of K+, Mn++). The analyses carried during the fermentative process are related to the concentration of substrate (sugar) and cells, with pH supervision and ethanol production. In accordance with the data obtained, it was verified a considerable microbial growth for the test with 2.5g of yeast, 30% of juice diluted in water at 30 °C and with potassium addition as micronutrient, suggesting that the same is capable of metabolize the sugars that are present in the broth converting it into biomass and secondary metabolites, even in low concentrations. So the use of Japanese grape (Hoveniadulcis) can be suggested as carbon and nutrients source for fermentative processes using Saccharomyces cerevisiae commercial strains, under moderate conditions of operation, for the production of ethanol or other metabolites with possible commercial interest.

Numerical Heat Transfer, Part A: Applications, 2010

This article presents an investigation into natural convection in trapezoidal cavities. It examin... more This article presents an investigation into natural convection in trapezoidal cavities. It examines a cavity whose floor and upper inclined walls are both adiabatic, while the vertical walls are isothermal. For these isothermal walls, we consider two thermal boundary conditions. Under the first condition, the short wall on the left side is heated as the tall one on the right side is cooled. The second condition is the reverse of the first-the short wall is cooled as the tall one is heated. Considering laminar conditions and a twodimensional system, steady-state computations are carried out to assess the effects of one and two baffles, the baffle's height (H b), Rayleigh number, 10 3 Ra 10 6 , and three Prandtl number values. To demonstrate the various effects, the results from several designed case studies are shown in terms of isotherms, streamlines, and local and average Nusselt numbers in order. Predictions reveal that the second baffle decreases the cavity's fluid flow and heat transfer. As the height of the baffle rises, the heat transfer drops drastically. Also, two baffles produce more pronounced thermal stratification than only one.

Journal of Water Process Engineering, 2019

The BTEX compounds have potential pollution with serious risk to the environment and human health... more The BTEX compounds have potential pollution with serious risk to the environment and human health. In this study, batch and continuous bioreactors, using biofilms supported on activated carbon particles were studied to remove BTEX compounds. The activated sludge from local wastewater treatment plant was adapted to biodegrade BTEX compounds and used in this work. The obtained results showed that the biofilm well adapted with the evaluated conditions and was able to conduct a complete degradation of BTEX compounds. Additionally, particles samples demonstrated higher bacteria content ranging from 79.40 (toluene) to 8.84 mg vss /L (o-xylene) of biomass amount. Kinetic parameters were obtained in a batch bioreactor fed daily with BTEX compounds. The tests showed that the biomass in the bioreactor was able to remove the BTEX compounds up to 300 min showing a potential strategy for the petrochemical industry. In addition, compared to the initial toxicity, after the treatment, a reduction in the acute toxicity up to 99% was observed confirm the potentiality of the proposed system in this study.

International Journal of Heat and Mass Transfer, 1987

Natural convection flow and heat transfer in a narrow vertical annulus located centrally above a ... more Natural convection flow and heat transfer in a narrow vertical annulus located centrally above a reservoir has been studied. The fluid in the reservoir is heated up by a hot, isothermal bottom end wall. The flow characteristics has been analysed by observing flow topologies and contours of temperature. Results are presented for Rayleigh numbers in the interval [2000-20000]. The flow consist of steady, periodic and quasi periodic regimes. The stream trace plot in each case is found to contain correct number of singularities of different types, which is required for satisfying the Hunts criterion. The annulus geometry selected for the study is a simplified model of the narrow annulus of a typical nuclear reactor design. The variation of circumferential temperature obtained from the study provides a relevant data for the design of nuclear reactors and similar systems.

Journal of Contaminant Hydrology

Process Safety and Environmental Protection, 2022

Chemical Engineering Research and Design, 2021

Abstract Based on CFD’s simulations using RANS and SGDH (Standard Gradient Diffusion Hypothesis),... more Abstract Based on CFD’s simulations using RANS and SGDH (Standard Gradient Diffusion Hypothesis), this study presents an alternative to better predict turbulent catalytic systems with surface reaction limited by mass transfer selecting an optimal turbulent Schmidt number (Sct). Simulations of H2O2 degradation were performed in an annular reactor with Mn/Al oxide immobilized into the wall using the AKN, RSM and standard k-e turbulence models with the Sct varying from 0.2 to 1.1. The numerical apparent reaction constant (kapp) was compared with literature data to verify the prediction errors. The ideal Sct was applied to simulate the benzoic acid photocatalytic degradation in photocatalytic reactor coated with TiO2 for different flow rates. The results showed that the Sct of 0.8 for AKN, 0.7 for RSM, and 0.2 for standard k-e are the best for systems with high mass transfer limitations and the Sct of 1.1 for AKN, 1.0 for RSM, and 0.4 for standard k-e are the best for systems with low mass transfer limitations. It was concluded that all turbulence models predicted well the mass transfer when the ideal Sct was used and the standard-k-e model could be an alternative since the prediction error was less than 6.5% with low computational cost.

Neste trabalho e avaliado o potencial biocatalitico da lipase de Candida rugosa (LCR) imobilizada... more Neste trabalho e avaliado o potencial biocatalitico da lipase de Candida rugosa (LCR) imobilizada em diferentes suportes: carvao ativado, gesso comercial e silica gel, visando a producao de biodiesel. O metodo de imobilizacao por adsorcao foi utilizado na imobilizacao da LCR nos suportes. A eficiencia de imobilizacao expressa em termos da razao entre a atividade do complexo suporte-LCR e atividade da enzima livre, foram estimados, fornecendo eficiencia de 89% para o carvao ativado-LCR, 62% para a silica gel-LCR e 48% para o gesso-LCR. O complexo carvao ativado-LCR forneceu o maior indice de acidez. A analise por cromatografia de camada delgada do biodiesel produzido por este complexo apresentou fatores de retencao e ordem de eluicao dos acilglicerois compativeis com a literatura, indicando um potencial deste complexo para a producao de biodiesel.

Journal of Petroleum Science and Engineering, 2022

Abstract One of the largest wastewater flows generated in the oil and gas industry is produced wa... more Abstract One of the largest wastewater flows generated in the oil and gas industry is produced water (PW), which can come from oil fields, gas fields or a combination of oil and gas fields. This effluent has a complex and variable chemical composition; it contains a significant amount, sometimes up to 500 mg L−1, of water soluble organic compounds (WSO) that are not easily removed by conventional physical-chemical treatment as coagulation and flotation. With the intensification in worldwide industrial activities, the generation of PW has consequently also increased and, from the environmental point of view, it is of fundamental importance to point out the alternatives for its proper management, in order to comply with legislation around the world and to provide safe subsequent destination (reuse and/or disposal). Furthermore, the treatment of this effluent is challenging and requires a lot of attention from both industry and academy. In this context, adsorption is known as one of the most effective technologies for removing WSO in polishing steps, since it is a technique of simple installation and maintenance, with low cost. Thus, this paper aims to review and highlight in detail (i) the main characteristics of produced water and its different forms of reuse, (ii) the theoretical fundaments of the adsorption technique and (iii) through case studies, critically evaluate the technical feasibility of implementing adsorption towers in PW treatment units.

Chemical Engineering Research and Design, 2021

Abstract A wide range of materials can be used for membrane production for wastewater treatment u... more Abstract A wide range of materials can be used for membrane production for wastewater treatment using membrane technology. Polymeric membranes have the disadvantage of high fouling tendency when used for oil-water wastewater, reducing the membrane flux. In this study, a simple superficial modification with polydopamine (PDA) coating was used, combined with the electrospinning technique to create an additional layer over the hydrophobic commercial polyvinylidene fluoride (PVDF) membrane, to achieve a hydrophilic surface and fouling resistance for oil-water separation. PVDF microfiltration membrane, with 0.22 μ m of pore size, was modified with PDA by deposition for 12 h. A layer of polyvinylpyrrolidone-co-polymethyl methacrylate (PVP-co-PMMA) was electrospun over the modified polydopamine membrane. The modified membrane showed a hydrophilic surface, with a higher clean water flux and a reduction of fouling during emulsion filtration, when compared with the commercial microfiltration PVDF membrane. So that a simple modification, forming a multilayer membrane, increased up to 4 times of clean water flux after the cleaning procedure of the membrane.

Journal of Cleaner Production, 2020

B.F. Skinner developed the operant laboratory using electromechanical technology available in the... more B.F. Skinner developed the operant laboratory using electromechanical technology available in the 1930s. Since then, electronics and digital computers have changed the way in which events are recorded, and experiments programed and controlled. However, the essential features of the operant preparation (a set of instruments, concepts, and procedures seamlessly integrated to reliably render samples of operant behavior) have remained for the most part intact. Years of accumulated knowledge may be necessary to understand the extent of a model's capacity and limitations. In the case of the operant preparation, a number of important limitations to its original accepted validity have appeared over time, derived from new data and more inclusive theoretical frameworks. The aim of this paper is to examine the significance of the operant assay, and to consider potential extensions to incorporate dimensions of behavior made possible by new and emerging theories and technologies.

Brazilian Journal of Chemical Engineering, 2020

A two-dimensional process of dyeing yarn coils was modelled in COMSOL Multiphysics to evaluate th... more A two-dimensional process of dyeing yarn coils was modelled in COMSOL Multiphysics to evaluate the dyeing characteristics according to a pilot-scale process. The proposed mathematical model was able to reproduce the experimental data and great importance was identified for the dyebath flow through the axial exit of the coil in relation to the radial outlet, about 2.8 times greater. To maintain the same flow, the permeability of the bobbin decreased tenfold between the radial and two-dimensional flow. Changes in the pressure gradient greatly influence the velocity field. The velocity and concentration fields found reinforce the preferential use of dyeing bobbins that do not have gaps between them, forcing the dyeing bath to follow the radial flow. Keyword Mathematical modelling • Permeability • Bobbin dyeing Abbreviations C ali Feed concentration in the inner bobbin radius (mol m −3) C i Dye concentration of the dyebath (mol m −3) C out Average dye concentration in the fluid phase of the bobbin (mol m −3) C p,j Dye conccentation in the solid phase (mol m −3) D h,j Hydrodynamic dispersion tensor (m 2 s −1) D e,j Effective diffusivity (m 2 s −1) P in Inlet pressure (Pa) P out Outlet pressure (Pa) V d Volume of dyeing bath (m 3) q p,j Adsorption isotherm (m 3 kg −1) Volume fraction of fluid phase (−) Volume fraction of solid phase (−) Specific mass of the fluid (kg m −3) Specific mass of the fiber (kg m −3) ∇ Differential operator (−) H Height of bobbin (m) Kl Langmuir constant (m 3 mol −1) Qmax Max adsorption (mol kg −1) Re External radius of bobbin (m) Ri Internal radius of bobbin (m) W Average weight of bobbin (kg) F Gravitational force (kg m −2 s −2) I Unit vector (−) P Presure (Pa) Q Volumetric flow rate of the dyeing bath (m 3 s −1) T Transposition operation (−) t Process time (s) u Velocity vector (m s −1) Viscous force coefficient (kg m −4) Permeability (m 2) Dynamic viscosity (kg m −1 s −1)

International Journal on Alive Engineering Education, 2017

Journal of hazardous materials, Jan 9, 2018

The aim of this work was to study the feasibility of textile sludge as a precursor to prepare cat... more The aim of this work was to study the feasibility of textile sludge as a precursor to prepare catalysts for catalytic wet peroxide oxidation (CWPO) by chemical and thermal treatments. Textile sludge was characterized by physical-chemical and metal composition analyses. The chemical activation was evaluated using iron sulfate and the thermal treatment was carried out at 720 °C in a vacuum pyrolysis reactor. Two catalysts with iron contents of 1.5% and 5.6% were selected. Process parameters influence on CWPO of phenol were evaluated and a maximum removal of phenol and TOC was observed at pH 3 and 60 °C, using 3 g L of the catalyst containing 5.6% of iron and 11.8 mmol L of HO. Metal analysis indicated that the textile sludge is suitable to be employed as both iron catalyst and adsorbent. The catalysts characterization indicated a reasonable surface area with a well-developed microporosity and the presence of Hematite structures in the carbonaceous matrix. The degradation process achie...

Brazilian Journal of Food Research, 2016

Brazilian sugar cane spirit (cachaça) production is traditional among rural producers in Santo An... more Brazilian sugar cane spirit (cachaça) production is traditional among rural producers in Santo Antônio da Patrulha-RS-Brazil. In this work, in similar conditions used by the producers, the effect of different °Brix and nutrients concentration on sugar cane juice fermentation time and ethanol yield was tested. Sixteen experiments were executed, predicted in a statistical planning, in order to identify the effect of eight factors. The results indicate that the increase on manganese sulfate concentration and cornmeal amount, and also the zinc sulfate concentration increase in interaction effect with higher °Brix, cause increase in fermentation time. It was also observed that the ethanol yield was higher at lower °Brix and at higher triple superphosphate amount in interaction effect with higher °Brix. Ammonium sulfate and copper sulfate concentrations, and also rice bran amount had no significant influence on the process. The best parameters determined, at local conditions, to obtain th...

Tese (doutorado) - Universidade Federal de Santa Catarina. Centro Tecnologico. Programa de Pos-Gr... more Tese (doutorado) - Universidade Federal de Santa Catarina. Centro Tecnologico. Programa de Pos-Graduacao em Engenharia Mecânica.

Informacion Tecnologica

Información Tecnologica, vol. 10, n. 2, pp.67-72, ISSN 0716-8756, Março/1999.

Application of Biofilm in the Degradation of Contaminants in Industrial Effluents, Chapter 10 of ... more Application of Biofilm in the Degradation of Contaminants in Industrial Effluents, Chapter 10 of Book: Biofilms: Formation, Development and Properties, Editor: William C. Bailey, ISBN: 978-1-61728-293-5, Nova Science Publishers, Inc., NY, USA, 2011.

International Journal of Heat and Mass Transfer, 2015

Journal of Food Process Engineering, 2014

ABSTRACT The kinetics of the hot-air drying of soybeans was modeled in order to evaluate the infl... more ABSTRACT The kinetics of the hot-air drying of soybeans was modeled in order to evaluate the influence of temperature and velocity on the kinetic parameters. A convective dryer with air temperature from 30 to 195C and air flows of 0.75, 1.35, 2.0 and 2.5 m/s was used. Three different mathematical models were applied to simulate the drying process (two empirical equations, exponential and Page's, and Fick's diffusion model) and the diffusivity coefficient increased from 2.5 × 10−11 to 6.69 × 10−10 m2/s for a range of air temperature between 30 and 195C. Both temperature and velocity influenced drying rate. The differential evolution optimization method was used toward parameter estimation. The goodness of fit of the proposed models, evaluated using linear regression coefficient (R2), chi-squared parameter (χ2) and root mean square error, indicated a satisfactory validation, mainly regarding to the exponential and Page's models.Practical ApplicationsAlthough biological materials are dried to improve shelf life, reduce packaging costs and enhance sensorial aspects, they are highly susceptible to quality deterioration during dehydration if the processing parameters are not well adjusted. The mathematical modeling of food drying provides results about the influence of process parameters on energy efficiency and final product quality in order to help the optimization and upscale application. Given that up to 40% of the agro-industrial production is lost in developing countries due to the lack of processing and that an energy efficiency improvement of 1% may result in 10% increase in profit, it is important to explore the potential of mathematical tools to properly study drying processes under an energy and qualitative approach.

Revista Brasileira de Pesquisa em Alimentos, 2012

Resumo: A produção de uma bebida fermento-destilada a partir da uva-Japão apresenta-se como uma b... more Resumo: A produção de uma bebida fermento-destilada a partir da uva-Japão apresenta-se como uma boa opção de complementação de renda para os pequenos produtores rurais. Os ensaios fermentativos foram conduzidos sob diferentes diluições de suco de uva-Japão (30 e 50%), diferentes temperaturas (30 e 35 °C), sem e com a adição de micronutrientes (fontes de K+, Mn++). As análises realizadas ao longo do processo fermentativo fazem referência à concentração de substrato (açúcar) e de células, com acompanhamento do pH e produção de etanol. De acordo com os dados obtidos, verificou-se um crescimento microbiano considerável para o teste com 2,5 g de fermento biológico, 30% de suco diluído em água a 30 °C e com adição de potássio como micronutriente, sugerindo que o mesmo é capaz de metabolizar os açúcares presentes no caldo, convertendo-o em biomassa e metabólitos secundários, mesmo em baixas concentrações. Desta forma, pode-se sugerir o uso da uva-Japão (Hoveniadulcis) como fonte de carbono e nutrientes para processos fermentativos utilizando-se cepas comerciais de Saccharomycescerevisiae, sob condições moderadas de operação, para a produção de etanol ou outros metabólitos com possível interesse comercial. Palavras-chave: Fermentação alcoólica. Uva-Japão (Hoveniadulcis). Destilação. Micronutrientes. Influence of nutrients addition in the fermentation kinetics of Japanese Grape juice by Saccharomyces SP. The production of a fermented distilled drink from Japanese grapeis presented as a good option of income complement to small farmers. The fermentative tests were conducted under different juice dilutions of Japanese grape (30 and 50%), different temperatures (30 and 35 °C), with and without the addition of micronutrients (sources of K+, Mn++). The analyses carried during the fermentative process are related to the concentration of substrate (sugar) and cells, with pH supervision and ethanol production. In accordance with the data obtained, it was verified a considerable microbial growth for the test with 2.5g of yeast, 30% of juice diluted in water at 30 °C and with potassium addition as micronutrient, suggesting that the same is capable of metabolize the sugars that are present in the broth converting it into biomass and secondary metabolites, even in low concentrations. So the use of Japanese grape (Hoveniadulcis) can be suggested as carbon and nutrients source for fermentative processes using Saccharomyces cerevisiae commercial strains, under moderate conditions of operation, for the production of ethanol or other metabolites with possible commercial interest.