Ardson dos S. Vianna Vianna Jr

Ardson dos S. Vianna Vianna Jr
University of São Paulo | USP · Departamento de Engenharia Química (PQI) (POLI)

Doctor of Engineering

About

47
Publications
8,174
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189
Citations
Citations since 2016
24 Research Items
151 Citations
2016201720182019202020212022051015202530
2016201720182019202020212022051015202530
2016201720182019202020212022051015202530
2016201720182019202020212022051015202530
Introduction
Dr. Vianna Jr. is an Associate Professor at the University of São Paulo, School of Engineering, Department of Chemical Engineering since June 2010. His main activities are in the field of fluid dynamics, which encompasses three different lines of research: 1- reactors that include polymerization, enzymatic degradation, and microreactors; 2- modeling and simulation; 3- multiphase flows. A core flow and continuous settler were evaluated using CFD tools.

Publications

Publications (47)
Article
Stochastic reasoning must be part of the comprehension of chemical and physical processes that occur in Nature. Stochastic phenomena can be found in several natural observations and in numerous Chemical Engineering related issues, such as optimization, process control, molecular diffusion, and chemical reaction kinetics. In the present work, an Act...
Conference Paper
Femtosecond laser micromachining was adopted to make a glass mixer with complex geometry. This special design promotes more efficient mixing in microreactor with gas-liquid flux at low flow rates, compared to conventional serpentine mixers.
Article
The enzymatic degradation of organic pollutants is a promising and ecological method for the remediation of industrial effluents. 2,4,6-Trichlorophenol is a major pollutant in many residual waters, and its consumption has been linked to lymphomas, leukemia, and liver cancer. The goal of the present work is to comprehend the enzymatic degradation of...
Article
O processo de geração de um modelo matemático deve ter como resultado uma simulação que represente o conjunto de dados experimentais. Diversos fenômenos na Natureza apresentam flutuações erráticas que são fenomenológicas. Um exemplo significativo é a trajetória que desenvolve um pólen que se movimenta na superfície de um rio, o movimento browniano....
Preprint
Full-text available
The enzymatic degradation of organic pollutants is a promising and ecological method for the remediation of industrial effluents. 2,4,6-Trichlorophenol is a major pollutant in many residual waters, and its consumption has been linked to lymphomas, leukemia, and liver cancer. The goal of the present work is to comprehend the enzymatic degradation of...
Article
The use of microfluidics can improve the process of droplet formation while reducing energy consumption. In the present work, a microreactor system with a double T junction and oval microchannel reactor 2509 mm long was analyzed. The stream was composed of styrene, water, and an emulsifier. The concentration of water in the emulsion and the flow ra...
Book
A ciência moderna procura representar fenômenos que ocorrem na natureza (como o crescimento populacional, cinética de reações e pêndulo simples) por equações matemáticas, especificamente por meio de equações diferenciais. Este livro de matemática aplicada se propõe a solucionar equações diferenciais com exemplos práticos. Procura-se compreender div...
Article
One of the difficulties related to oil exploration is transporting heavy oil since its high viscosity causes high‐pressure drop and energy consumption. In order to save energy, the core annular flow (CAF) can be applied where a two‐phase annular flow occurs, with peripheral water flowing offering a reduction in energy expenditure. The multiphase fl...
Article
Full-text available
Soybean peroxidase is an enzyme extracted from soybean seed hulls. In the presence of hydrogen peroxide, the enzyme has the potential to catalyze the biodegradation of toxic substances like chlorophenols. For this reason, its use in wastewater treatment processes is environmentally friendly since the enzyme can be obtained from a renewable and abun...
Conference Paper
Soybean peroxidase is a Fe(III)-heme enzyme that can be extracted from soybean seed hulls, and in the presence of hydrogen peroxide it has the potential to catalyze the decomposition of some substrates, such as amines and phenols. In this work, we study the degradation of 2,4,6-trichlorophenol catalyzed by soybean peroxidase. The experimental data...
Article
Continuous settlers are present in the treatment of effluents and domestic water. They have low operational and maintenance cost; however, they can reach high separation efficiency. In this work, the fluid dynamic characteristics of the settler in bench scale, with no-concentric axial inlet in the feedwell were precisely evaluated, using both exper...
Article
The concentration profiles of species involved in the degradation of phenol by an advanced oxidation processes (AOP) are modeled using a CFD tool, in an annular reactor whose fluid dynamics was the object of a previous study. The reactive flow was fully described together with the kinetic model, which encompasses large kinetic constants, such as 10...
Article
Microreactors eliminate batch‐to‐batch variability and allow better control over nanocrystal synthesis. A serpentine microreactor fabricated by femtosecond laser ablation is presented and characterized by computational fluid dynamics, since the micro channels show a trapezoidal cross‐section mainly due to the relatively high numerical aperture of t...
Conference Paper
Full-text available
Soybean peroxidase is an enzyme that can be sustainably harvested and has the potential to decompose harmful compounds. It may oxidize organic substrates using hydrogen peroxide as electron acceptor, and it is cheap and easy to obtain because Brazil is the second largest soybean producer in the world. However, before the potential of this enzyme ca...
Article
The transport of heavy oil in tubes is energy intensive since the oil viscosity can reach values of 10 500 000 cP. This study focuses on the transport of oil in a piping system by an annular flow of oil wrapped with water, since this alternative reduces head loss. The piping system was comprised of horizontal tubes, curves, and vertical tubes. The...
Article
Full-text available
O gás natural vem aumentando significativamente sua participação na matriz energética mundial. Um dos tópicos que devem ser avaliados é o transporte deste gás, que ocorre em malha de gasodutos. Este trabalho tem por objetivo estudar a condensação que ocorre no escoamento de gás natural não processado utilizando a ferramenta CFD. As simulações em o...
Article
A reflection on teaching programming at undergraduate level using advanced tools is presented. Advanced digital tools and computational evolution have shaped different areas, such as industrial process, communications, education and innovation. New technologies, such as the Internet of Things-IoT, cloud computing and artificial intelligence, have b...
Article
A stochastic model based on the axial dispersion model was proposed for the mathematical representation of the fluid dynamics of tubular equipment with irregular behavior. The differential equation was built by inserting randomness in the dispersion coefficient, which added a stochastic term to the model. This term was capable of simulating fluctua...
Article
Full-text available
Microfluidic reaction devices are a very promising technology for chemical and biochemical processes. In microreactors, the micro dimensions, coupled with a high surface area/volume ratio, permit rapid heat exchange and mass transfer, resulting in higher reaction yields and reaction rates than in conventional reactors. Moreover, the lower energy co...
Article
Full-text available
In this work an application of decomposition techniques on a propylene production unit from REPLAN refinery by Petrobras S.A. is presented. It is shown that the classic Lagrangian Relaxation (LR) technique and the alternative technique called "Pricing Interprocess Streams Using Slack Auctions" (PISUSA) do not converge for the case study presented....
Article
Millireactors offer the same advantages of microreactors, which are high surface to volume ratios and low Reynolds numbers (laminar flow). Polymerization reactions concerning high heat quantities and so it is an excellent example of medium that can be used in microreactors. The Syrris ASIA millireactor, 4.0mL volume, was employed for the polymeriza...
Article
Full-text available
Photochemical reactors tend to exhibit turbulent flow even with low Reynolds numbers. The k-ϵ model is not always appropriate in this situation. An annular photoreactor was designed with tangential inlet and outlet tubes to investigate this. The fluid flow was characterized by residence time distribution (RTD) experiments, which were reproduced by...
Article
Full-text available
Computational Fluid Dynamics is a modeling and simulation tool which can be used to understand tridimensional flows, for instance, the distributions of concentrations of chemicals. This work provides the basics of Computational Fluid Dynamics in order to emphasize its importance. Two case studies are presented, one is the chlorine gas dispersion fr...
Article
The modeling, analysis, and simulation validation of an industrial-scale depropenizer column (Refinaria de Capuava, Mauá, São Paulo) owned by Petrobras S.A. are carried out using equation-oriented and sequential modular approaches. The model implemented in the equation-oriented environment proved to be suitable for real-time optimization (RTO) appl...
Article
Full-text available
GAP is an aliphatic polyether that includes hydroxyl groups and highly energetic azide groups. Thus, it is an energetic material that can be used as binder or plasticizing agent in propellants and explosive mixtures. The glycidyl azide polymer (GAP) was synthesized and characterized by direct conversion of epichlorohydrin. GAP was synthesized by re...
Article
Full-text available
GAP is an energetic material that can be used as binder or plasticizing agent in propellants and explosive mixtures. The glycidyl azide polymer (GAP) can be synthesized by direct conversion of epichlorohydrin. Here, a mechanism is proposed for the reaction used, based on an analysis of infrared spectra of intermediate species.
Article
The fluid dynamics of three styrene tubular polymerization reactors were analyzed theoretically and experimentally through washout perturbation. The analysis was developed through initiator negative step inputs and monomer conversion outputs, and thus additional analytic methods were not necessary as no tracer was used. The results were evaluated b...
Article
A stochastic model that was proposed to annular flow in a tubular reactor is used here to other complex fluid dynamics. The model was constructed from basic diffusion equations with a stochastic term. Numerical simulation was utilized to generate sample paths fitting the residence time distributions (RTD) of a circulating fluidized bed riser. The m...
Article
Full-text available
This article discusses a survey on the technology of Computational Fluid Dynamics (CFD) in various areas of knowledge and applied particularly in polymers, with scientific articles and patents as sources of information. All the data were mined using "computational", "fluid" and "dynamic" as keywords. It was observed that private companies are respo...
Article
Full-text available
A stochastic model representing annular flow in a tubular reactor is proposed. Numerical simulation was utilized to generate sample paths fitting the residence time distributions (RTD) of the system. The model was constructed from basic diffusion equations with the additional consideration of random effects disturbing the system, thus yielding a st...
Article
Thermal batteries are primary disposable systems specially designed to develop a high energy density in a short period. In the present work, the modeling of heat generation and propagation within three Ca/CaCrO4 thermal batteries has been carried out, using a transient model. The commercial CFD software Phoenics' has been used and, through a typica...
Article
Residence time distributions were evaluated experimentally for three tubular solution polymerization reactors to analyze aspects of the fluid-dynamic behavior of these reactors. The analysis of the available experimental data indicates that the flow characteristics of these reactors may be subject to stochastic perturbations. A stochastic flow mode...
Article
Full-text available
The fluid dynamics of a tubular polymerization reactor is evaluated by tracer perturbation. The residence time distribution (F(t)) obtained experimentally seems to be governed by stochastic phenomena, since F(t) oscillations that cannot be explained by experimental errors are observed around the value 1. In order to explain the oscillatory behavior...
Article
Full-text available
Thermal batteries are primary disposable systems specially designed to develop a high energy density in during a short period. Differently from the classical electrochemical systems, the electrolyte of such batteries is solid at room temperature, which make them inert until they are heated to high temperatures (around 500�C), when the electrolyte m...
Article
Full-text available
Thermal batteries are primary disposable systems specially designed to develop a high energy density in a short period. In the present work, the modeling of heat generation and propagation within three Ca/CaCrO4 thermal batteries has been carried out, using a transient model. The commercial CFD software Phoenics® has been used and, through a typica...

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