Teses em Engenharia de Recursos Naturais da Amazônia (Doutorado) - PRODERNA/ITEC

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4045

O Doutorado Acadêmico inicou-se em 2006 e pertence ao Programa de Pós-Graduação em Engenharia de Recursos Naturais da Amazônia (PRODERNA) do Instituto de Tecnologia da UFPA (ITEC) da Universidade Federal do Pará (UFPA).

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Agora exibindo 1 - 10 de 10

Acesso aberto (Open Access)
Análise da convecção natural no escoamento laminar em cavidades parcialmente preenchidas com meios porosos utilizando transformadas integrais
(Universidade Federal do Pará, 2016-04-15) QUARESMA, Sil Franciley dos Santos; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
A numerical study is performed to analyze the natural convection in a vertical rectangular enclosure that is partially filled with a porous medium, by the Generalized Integral Transform Technique (GITT). The first studies concerning flow transient in a channel partially filled with porous medium without the effect of natural convection in order to understand the technical solution or problems with interfaces. Two different formulations were studied: the two-domain approach and the single-domain approach. Subsequently a numerical study is performed to analyze the steady-state thermal natural convection fluid flow and heat transfer in a vertical rectangular enclosure that is partially filled with a porous medium. The flow is modeled using the Brinkman- Forchheimer extended Darcy and energy conservation equation was used to predict the heat transfer. The mathematical description of the problem is based on a one-domain formulation of the conservation equations. Finally it carried out the study of double diffusive natural convection, also nominated thermosolutal natural convection in partially porous enclosures. The validity of the so-called one-domain approach used in this case compared to existing results in the literature. A particular class of problems dealing with thermal and double diffusive natural convection mechanisms in partially porous enclosures is presented, and it is shown that this configuration exhibits specific features in terms of the heat and mass transfer characteristics.
Acesso aberto (Open Access)
Análise da transferência de calor convectiva por transformada integral em canais com paredes onduladas
(Universidade Federal do Pará, 2019-12-13) MIYAGAWA, Helder Kiyoshi; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785; https://orcid.org/0000-0001-9365-7498
The hybrid numerical-analytical approach known as the Generalized Integral Transformation Technique (GITT) is employed in the solution of the Navier-Stokes and energy equations that mathematically model the convective heat transfer in corrugated wall channels. The flow is considered laminar, incompressible, and two-dimensional involving a Newtonian fluid with temperature-independent physical properties, while wall temperatures are kept constant along the length of the channel. The streamfunction formulation is adopted, which eliminates the pressure field and automatically satisfies the continuity equation. Extensive convergence analyses are performed for the streamfunction and temperature fields, as well as for the product of friction factor by the Reynolds number and the local Nusselt number to demonstrate the robustness of the method. Verification of GITT results is also performed by comparing the centerline velocity, product of friction factor by the Reynolds number, average temperature, and local Nusselt number with those results obtained with the commercial COMSOL Multiphysics simulation software showing good agreement. The influence of parameters such as Reynolds number, wavy wall amplitude, number of waves, and phase between wall corrugations on the fields of velocity, temperature, and entropy generation are also analyzed, demonstrating their importance for convective heat transfer intensification and energy optimization.
Acesso aberto (Open Access)
Análise de vibrações mecânicas em estruturas esbeltas e flexíveis, como cordas e vigas, sujeitas à movimentação axial utilizando a técnica da transformada integral generalizada
(Universidade Federal do Pará, 2024-05-28) PORFÍRIO, Rogilson Nazaré da Silva; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785; https://orcid.org/0000-0001-9365-7498
The dynamic analysis of vibrations on flexible structures is of an extreme importance in engineering and its solution represents a significant challenge to be tackled. This study has the objective to investigate thin and flexible structures such as beams and ropes, that oscillate in supports clamped-clamped and clamped-concentrated mass, which determine the boundary conditions of the analysis problem. Using the generalized integral transformation technique (GITT) that converts the partial differential equation (PDE) developed by the Hamiltonian method in an Ordinary Differential Equation (ODE), it optimizes the numerical process andcontrols efficiently the relative error of the calculations. In this study, it was developed and applied an innovative method that treats the boundary conditions without the use of filters to homogenize the equations. The calculations methodology was implemented in Fortran, utilizing a sub-routine DIVPAG of IMSL. As reference, a thorough analysis of convergence and stableness was applied, considering the behavior of four different models of ropes and two models of beams. The validation of methodology was approached comparing functional aspects such as transversal displacement, system velocities, frequencies, and damping, with results obtained by GITT and other studies that applied the same simulation conditions. The results of this study were found to be satisfactory, which highlights the relevancy of application of this vibration analysis method. It was also assessed the application of this method in different vibration configurations in each model, which exemplifies its broad potential in problems involving the structures analyzed. Therefore, this study represents a significant contribution to the advance of knowledge in dynamic modeling of thin and flexible structures and highlights the influence of boundary conditions in vibrational characteristics of these structures.Furthermore, it introduces an innovative methodology for treating boundary conditions without the use of filters, expanding the analysis possibilities in this field of engineering.
Acesso aberto (Open Access)
Análise teórico-experimental da biotransferência de calor em tecidos sintéticos aquecidos por ultrassom
(Universidade Federal do Pará, 2016-04-14) AMORIM, Nelson de Souza; COTTA, Renato Machado; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
The inverse problem of parameter estimation for the bioheat transfer problem in sintetic tissue was analyzed. Initially an experimental analysis was developed by heating a synthetic tissue using a ultrasound transducer. Different temperature profiles were obtained for 3 cases involving intensity variations: 1W/cm2, 1.5W/cm2 and 2W/cm2 for 3 thermocouples positioned along the sintetic tissue. A mathematical model was develeped to represent the experimental problem. The solution of this model was obtained using the Classical Integral Transform Technique (CITT). The Levenberg-Marquardt Method was used to solve the parameter estimation for the attenuation of sintetic tissue. A comparison between experimental solution and the mathematical model was performed.
Acesso aberto (Open Access)
Aplicação da transformada integral generalizada em mancais radiais operando com fluidos não-newtonianos tipo lei da potência
(Universidade Federal do Pará, 2016-02-29) MAGNO, Rui Nelson Otoni; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
This work present a study of the hydrodynamic lubrication of full journal bearings with non-Newtonian lubricants, obeying the power-law model. The formulation of the problem is obtained from the general equations of motion, after being taken over some simplifying assumptions inherent of the problem were taken. The regular perturbation method is applied on the governing equations for determining velocity profiles, and on generalized Reynolds Equation for Non-Newtonian lubricant. Solutions for borderline cases were obtained analytically. Then the generalized Reynolds equation is resolved through the Generalized Integral Transform Technique (GITT). For the calculation a computer code was developed in FORTRAN 90/95 which used the BVPFD subroutine from IMSL Library (2014). Numerical results for operational performance parameters such as pressure field, load capacity, Sommerfeld number, attitude angle, friction coefficient and axial flow rate were established and showed excellent agreement when compared with results available in the literature, for different eccentricities, aspect ratios "" and power-law index "n". Also it was studied the influence of surface texture, using sinusoidal, positive full and half wave roughness (transversal roughness). The transversal positive full wave is best for increasing the pressure, load carrying capacity and axial flow, again the results are excelente agreement with data available in the literature.
Acesso aberto (Open Access)
Estudo e avaliação do uso de resíduos do processo Bayer como matéria-prima na produção de agregados sintéticos para a construção civil
(Universidade Federal do Pará, 2010-03) SOUZA, José Antônio da Silva; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
The large amount of solid waste coming from mines and metallurgical industries became a serious social-environmental problem. The physical and chemical features of this material can raise a great interest in other industries. The ceramic industry might be a great costumer for most of this material, since it can supply the current lack of raw material. The red mud, main industrial residue of the alumina manufacturing, has been a very interesting input for several kinds of aggregates manufacturing used for the concrete production in civil engineering. In this context, this paper deals with studies concerning the red mud recycling to be applied as raw material for the synthetic light aggregate production to be used as an alternative material in the civil construction industry. This is because of its physical-chemical features and the large amount annually produced (around 10 million tons within two factories in the North of Brazil). The studies completed in this work show the feasibility of aggregates manufacturing, with different properties and possibilities. These properties depend on the parameters control such as content of free silica and clay, and the sintering temperature. Such variables allow to perfectly controlling the glassy phase formation which is responsible for the aggregate properties such as: porosity, mechanical resistance and density. This material can be used for conventional or special concretes to supply the civil engineering needs.
Acesso aberto (Open Access)
Obtenção de açúcares fermentescíveis a partir da casca de andiroba (carapa guianensis aubl.): estudo do pré-tratamento alcalino e avaliação cinética
(Universidade Federal do Pará, 2020-01-24) SOUZA, Leiliane do Socorro Sodré de; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785; https://orcid.org/0000-0001-9365-7498
Neste trabalho, as cascas das sementes de andiroba foram submetidas a pré- tratamento alcalino, visando maximizar a recuperação dos açúcares redutores, avaliando o melhor desempenho de operação através das variáveis, tempo de reação (20, 60 e 100 min), concentração de NaOH (2, 3 e 4% (m/v)) e temperatura (60, 90 e 120ºC), em concentração de sólidos fixa, de 5% (m/v). Foi utilizado o planejamento experimental de Box-Behnken (15 ensaios). A biomassa pré-tratada nos 15 experimentos, foi hidrolisada enzimaticamente, em condições idênticas, carga de sólidos (5%), carga enzimática (15 FPU/g de biomassa) e tempo de reação (48 horas). O material lignocelulósico foi caracterizado através das análises de celulose (36,96 %), hemicelulose (16,74 %), lignina (36,02 %), extrativos (7,49 %), umidade (9,21 %), e cinzas (1,53 %). A otimização foi realizada por meio da abordagem metodologia de superfície de resposta. O modelo forneceu um coeficiente de determinação (R2) de 0,96, para sacarificação e 0,97, para sólidos recuperados. As condições ótimas previstas para realizar o processo foram, tempo de reação = 100 min, concentração de NaOH = 4% (m/v), temperatura = 120ºC, que permitiram obter uma conversão em termos de açúcares redutores de 47,89 %. O material lignocelulósico pré-tratado nas melhores condições, foi avaliado morfologicamente, através das análises de Espectroscopia no Infravermelho com Transformada de Fourier (FTIR) e Microscopia Eletrônica de Varredura (MEV), onde foi possível observar a maior disponibilidade da fração celulósica. Através do pré-tratamento alcalino foi possível reduzir em 34,7 % a fração de lignina, e em 23,52 % a fração de hemicelulose. A biomassa tratada nas melhores condições determinadas através da análise estatística foi hidrolisada e a cinética de sacarificação foi acompanhada. O processo foi acompanhado por um período de 96 horas, e foi possível observar que o rendimento de 54,44 % foi alcançado para um tempo de 72 horas, após esse período não houve mais aumento significativo. Os resíduos gerados na etapa de tratamento alcalino (licor negro) e hidrólise enzimática (biomassa residual), foram caracterizados através de FTIR e análise termogravimétrica, respectivamente, o que permitiu observar a presença predominante de lignina no licor negro, e de celulose na biomassa residual. Estes resultados podem ser considerados satisfatórios no contexto da biomassa florestal e pode ser elevado em uma escala futura do laboratório para a escala piloto, com estudos sobre a etapa de hidrólise enzimática.
Acesso aberto (Open Access)
Obtenção de geopolímero a partir de rejeito da lavagem de bauxita amazônica
(Universidade Federal do Pará, 2022-12-12) RACANELLI, Lêda de Azevedo; SOUZA, José Antonio da Silva; http://lattes.cnpq.br/6157348947425968; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
The state of Pará is the largest national producer of bauxite, representing 85% of the Brazilian production of the ore and, as a result of this large production, it also represents the largest accumulator of tailings from the processing of this ore, which are deposited in lagoons and/or dams. The intense presence of silico-aluminates in this material, such as kaolinite, for example, demonstrates the great potential for the civil construction industry, that is, the possibility of producing geopolymeric materials from this waste. Bauxite washing, after calcination, transforms into amorphous material, more specifically into metakaolinite, which can be further potentiated when mixed with other residues as an additional source of Al and Si, which in this case is the so-called kaolin flint. As the waste from the bauxite washing has a limited amount of kaolinite, calcined flint kaolin was added to increase the metakaolinite content, helping in the geopolymerization reaction process. The raw materials and geopolymeric samples underwent characterization, and the main analyzes involved were: X-ray fluorescence (FRX), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Compressive strength tests were also carried out on the geopolymeric samples to assess the degree of polymerization, since the more polymerized the structure is, the greater the resistance. After 28 days of curing, the geopolymeric paste in the 80_RLBC formulation reached a compressive strength of 36 MPa and, of the 90_RLBC formulation, approximately 23 MPa at 28 days. The best results were obtained with samples activated with 9 mol/l of NaOH in the mixture with sodium silicate. The results obtained through the characterization analyzes of the samples demonstrated that the waste from the washing of bauxite and calcined flint kaolin, when activated with sodium hydroxide and sodium silicate, are a viable alternative for the production of geopolymeric materials
Acesso aberto (Open Access)
Solução de equações de balanço populacional usando a técnica da transformada de Laplace e filtro de partículas
(Universidade Federal do Pará, 2011-12) BATISTA, Clauderino da Silva; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
The evolution of particle size distribution in many fields of applied science, such as crystallization, aerosols, colloids, and polymer processing, can be obtained by solving population balance equation (PBE). The Laplace transform technique with numerical inversion was used to solve an integro-partial-differential equation related to the mathematical modeling of the physical problem to study convective processes with birth and death rates of particles or aerosols. Such model is governed by the population balance equation (PBE), in which is taken into account the nucleation, growth and coagulation processes. A Bayesian method was employed to solve the hyperbolic and non-linear inverse problem and estimate the size distribution density function, thus predicting the dynamic behavior of the physical system. Specifically the particle filter with sampling Importance Resampling (SIR) has been applied as a method of solving the problem. From these solutions, numerical results were obtained and compared with those in the literature for particulate systems permitting a critical evaluation of the present solution methodology.
Acesso aberto (Open Access)
A técnica da transformada integral na modelagem e simulação de processos de separação de metais por membranas difusivas poliméricas
(Universidade Federal do Pará, 2012-11) CARDOSO, Simone de Aviz; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785
The Generalized Integral Transform Technique (GITT) was used in the analysis of the metal extraction process with flat and tubular membranes. For the study of flat membrane, we analyzed the extraction of metals cadmium, Cd (II), gold, Au (III) and palladium, Pd (II) in polymeric diffusive membrane with Aliquat 336/PVC and the equations of chemical species were solved by the GITT methodology. In a second study, the Coupled Integral Equations Approach (CIEA) was used to analyze the same problem. In the study of hollow-fiber tubular membrane, the GITT methodology was also utilized for analyzing the influence of transport conditions for the solute of interest at the interface fluid and membrane phases of a mass separation process in tubular membranes as a function of the governing parameters of the problem. In this type of extraction, liquid extractants are used in the pores of the fiber membrane to facilitate the separation of the mass. In both studies, comparisons were made with those results from the literature demonstrating the potential of this technique in dealing with problems of such natures.

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