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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Item Acesso aberto (Open Access) Uma abordagem matemática aplicada ao projeto de turbinas hidrocinéticas e eólicas com difusor utilizando a teoria do elemento de pá(Universidade Federal do Pará, 2019-04-30) VAZ, Déborah Aline Tavares Dias do Rio; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975It is known surrounding a turbine with diffuser may significantly increase its power. This effect has attained considerable attention as it shows theoretically the possibility of achieving a power coefficient about 2 times greater than an ordinary turbine. However, the effect of the diffuser efficiency has not been implemented into blade element momentum yet, as well as the use of minimum pressure coefficient criterion to avoid cavitation during the optimization of the hydrokinetic chord along the blade. Hence, this work presents a novel approach to design diffuser-augmented hydro turbines considering the diffuser efficiency. Based on the blade element momentum, new expressions for the axial induction factor and thrust are obtained. In addition, both efficiency and load generated on a diffuser are considered to the extension of existing formulation to determine power coefficient in cases where diffuser losses are taken into account through efficiency (ηd) and area ratio (β). To assess the proposed model, a comparative evaluation of two different diffusers (flanged conical diffuser and flanged lens diffuser) is performed. Numerical and theoretical results are compared for a shrouded turbine equipped with 83% efficiency diffuser. The relative difference observed for the maximum power coefficient between the proposed model and an actuator disk model with diffuser is about 5.3%. For the hydro turbine with flanged conical diffuser, the mass flow rate is about 20% higher than for a bare turbine, while for the turbine with flanged lens diffuser the increase is only 2.4%. Also, for the flanged conical diffuser the power is increased by 53%. Furthermore, it is observed that the proposed blade element momentum with diffuser achieved good agreement with the numerical model, providing improved results compared to other models available in the literature. The optimization model of hydrokinetic chord shows relevant results in relation to the prevention of cavitation.Item Acesso aberto (Open Access) Análise energética, exergética e tecnoeconômica de um sistema de condicionamento de ar baseado na regulação natural da energia solar em condições climáticas da Amazônia(Universidade Federal do Pará, 2023-09-01) SANTOS, Elson Costa dos; MACÊDO, Wilson Negrão; http://lattes.cnpq.br/3386249951714088This work investigates the behavior of a photovoltaic air conditioning system, without batteries or connection to the electrical grid, operating according to the natural regulation of solar energy, in climatic conditions in the Amazon, a region with significant energy challenges, where in many locations, children, adolescents, adults and the elderly live without one of the main inputs for the development of productive, educational, leisure and even subsistence activities. The simulation results indicate that a system powered by a 1400 Wp photovoltaic generator can maintain thermal comfort conditions, with temperatures between 20 °C and 26 °C and relative humidity between 40% and 80%, for almost half of the operating time. and without any active control. Exergy analyses reveal variations in efficiency and irreversibility of components throughout the day, with the greatest impact on the photovoltaic system, followed by the compressor, condenser, evaporator, and expansion valve. Furthermore, the economic analysis shows that the implementation of these systems in parallel to systems powered by the conventional electrical grid can reduce grid energy consumption by 60.76%, and is strongly related to the tariff charged by the energy concessionaire. Finally, the research demonstrates the use of photovoltaic air conditioning systems as a sustainable solution for cooling, showing its effectiveness with the natural regulation of solar energy and its economic contribution to reducing the consumption of non-renewable energyItem Acesso aberto (Open Access) Análise quase-estacionária de pequena turbina eólica com pás curvadas(Universidade Federal do Pará, 2023-10-20) VELOSO, Mauro José Guerreiro; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975The installed power generation capacity in renewable energy has stood out in Brazil lately. The Anuário Estatístico Energético Nacional 2023 reported that wind energy improved by 14.3% from 2021 to 2022. Despite the wind energy potential generation in Brazil, there are still obstacles to overcome, including challenges in research and development. So, researchers have conducted investigations on renewable energy, focusing on studying wind turbines' design and performance evaluation and other efforts to alleviate that task. Hence, research has not been conducted on the dynamic starting behavior of small wind turbines with different blade curvatures in wind power systems. In this sense, the main objective of this work is to analyze the influence of different angles of blade curvature on the dynamic response on starting the coupled turbine-generator set. Newton's second law, the blade element theory, and the extension of the Palmgren method are applied to obtain the wind turbine behavior at the start. The dynamic behavior measurements available in the literature at the start of the straight-blade wind turbine is been applied as a reference baseline to validate the methodology. Numerical simulations demonstrate that during start-up, turbines with straight blades and forward-swept blades start in less time, are approximately 19.9% faster at starting, and require 10.7% less wind speed than turbines with backward-swept blades. Compared to straight-blade turbines, backward-swept blade turbines increase the dissipative torque up to 5.86% and the dynamic efforts by 22%. These results indicate the significance of blade geometry on turbine performance and the existence of a swept angle at which the turbine performs better than other angles of the swept blade.Item Acesso aberto (Open Access) Avaliação de potencial hidrocinético à jusante de centrais hidrelétricas(Universidade Federal do Pará, 2017-12) HOLANDA, Patrícia da Silva; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662; SECRETAN, Yves; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808The maximization of the performance of hydropower projects by taking advantage of the remaining energy downstream of dams via the installation of hydrokinetic turbines is feasible. In this context, two case studies of the hydroelectric power plants are presented, one of large Tucuruí in the Tocatins river, Amazonia, and another of medium size Bariri in the Tietê river, in the Southeast of Brazil.In central hydrokinetic projects, the design of the rotor diameter and velocity of the water are fundamental and depend on the depth and velocity of the river, respectively. Thus, the Saint-Venant model has been applied to these areas of studies. The calibration of the model was performed by linear regression of the measured and simulated flow rates for both, resulting in a correlation of 0.99. Validation was performed for a point on the Tocantins river using velocities measured with an acoustic Doppler current profiler (ADCP). The measured velocities are comparable to the velocities simulated by the model. Thus, a power curve was generated for the measured flow rates and the simulated velocities for the point at which the velocities were validated, thus obtaining a correlation of 0.96. This same curve was used for estimates of velocity, calculation of the energy density, and defining a design velocity for Tucuruí HPP equal to 2.35 m/s and Bariri 2.25 m/s. After the design was velocity defined, 10 points were selected Tucuruí and 1 point Bariri for the location of hydrokinetic turbines. The velocities of these points were determined with the same method used for the validation of the velocities. The points were selected based on the channel downstream of the reservoir and at the end of the Bariri dissipation basin, with the largest depth and velocity, which are characteristics favorable for greater power generation. Considering the rivers depth and available manufacturing technology, the rotor diameter was defined for the large study in 10 m and for the medium 2.1 m. After the design velocity was defined, the rotor design was implemented using the blade element method (BEM Blade Element Momentum), allowing for the definition of an installed power curve of the turbine as a function of the river velocity. In terms of generated energy, the 10 turbines can generate 2.04 GWh/year. These numbers demonstrate the potential for utilizing the remaining energy of hydroelectric plants.Item Acesso aberto (Open Access) Descontaminação de máscaras N95 em hospital público de Belém/PA: apresentação e avaliação de protocolo simplificado(Universidade Federal do Pará, 2024-11-25) MATTOS, Simone Lopes de; DIAS, Carmen Gilda Barroso Tavares; http://lattes.cnpq.br/2113791118142177he author presents a protocol for decontamination of N95 filter masks by means of short wave ultraviolet irradiation (UV-C), as well as the results of the microbiological validation testing of the UV-C device and qualitative research on the adherence of professionals from the João de Barros Barreto University Hospital, of the University Hospital Complex of the Federal University of Pará (HUJBB) to the aforementioned protocol. The microbiological tests demonstrated the efficacy of the decontamination protocol, as there was no bacterial growth in culture media inoculated with swabs of masks used in the hospital and decontaminated in the UV-C device, which proved the germicidal efficiency of UV-C irradiation. The results of the qualitative research point to the adherence of nursing professionals to the practice of mask decontamination, recognizing the practicality and contribution of the protocol to biosafety and occupational safety. As part of the same protocol, an alternative packaging for storing masks in the intervals of use of N95 masks is presented, considering their safe reuse. The protocol also has the following advantages: low cost and practicality of use, in addition to contributing to the reduction of infectious waste. Descriptors: Decontamination. Ultraviolet Rays. Radiation Dosimeters. Personal Protective Equipment. Respiratory Protection Devices. biosecurity.he author presents a protocol for decontamination of N95 filter masks by means of short wave ultraviolet irradiation (UV-C), as well as the results of the microbiological validation testing of the UV-C device and qualitative research on the adherence of professionals from the João de Barros Barreto University Hospital, of the University Hospital Complex of the Federal University of Pará (HUJBB) to the aforementioned protocol. The microbiological tests demonstrated the efficacy of the decontamination protocol, as there was no bacterial growth in culture media inoculated with swabs of masks used in the hospital and decontaminated in the UV-C device, which proved the germicidal efficiency of UV-C irradiation. The results of the qualitative research point to the adherence of nursing professionals to the practice of mask decontamination, recognizing the practicality and contribution of the protocol to biosafety and occupational safety. As part of the same protocol, an alternative packaging for storing masks in the intervals of use of N95 masks is presented, considering their safe reuse. The protocol also has the following advantages: low cost and practicality of use, in addition to contributing to the reduction of infectious waste. Descriptors: Decontamination. Ultraviolet Rays. Radiation Dosimeters. Personal Protective Equipment. Respiratory Protection Devices. biosecurity.he author presents a protocol for decontamination of N95 filter masks by means of short wave ultraviolet irradiation (UV-C), as well as the results of the microbiological validation testing of the UV-C device and qualitative research on the adherence of professionals from the João de Barros Barreto University Hospital, of the University Hospital Complex of the Federal University of Pará (HUJBB) to the aforementioned protocol. The microbiological tests demonstrated the efficacy of the decontamination protocol, as there was no bacterial growth in culture media inoculated with swabs of masks used in the hospital and decontaminated in the UV-C device, which proved the germicidal efficiency of UV-C irradiation. The results of the qualitative research point to the adherence of nursing professionals to the practice of mask decontamination, recognizing the practicality and contribution of the protocol to biosafety and occupational safety. As part of the same protocol, an alternative packaging for storing masks in the intervals of use of N95 masks is presented, considering their safe reuse. The protocol also has the following advantages: low cost and practicality of use, in addition to contributing to the reduction of infectious waste. Descriptors: Decontamination. Ultraviolet Rays. Radiation Dosimeters. Personal Protective Equipment. Respiratory Protection Devices. biosecurity.he author presents a protocol for decontamination of N95 filter masks by means of short wave ultraviolet irradiation (UV-C), as well as the results of the microbiological validation testing of the UV-C device and qualitative research on the adherence of professionals from the João de Barros Barreto University Hospital, of the University Hospital Complex of the Federal University of Pará (HUJBB) to the aforementioned protocol. The microbiological tests demonstrated the efficacy of the decontamination protocol, as there was no bacterial growth in culture media inoculated with swabs of masks used in the hospital and decontaminated in the UV-C device, which proved the germicidal efficiency of UV-C irradiation. The results of the qualitative research point to the adherence of nursing professionals to the practice of mask decontamination, recognizing the practicality and contribution of the protocol to biosafety and occupational safety. As part of the same protocol, an alternative packaging for storing masks in the intervals of use of N95 masks is presented, considering their safe reuse. The protocol also has the following advantages: low cost and practicality of use, in addition to contributing to the reduction of infectious waste. Descriptors: Decontamination. Ultraviolet Rays. Radiation Dosimeters. Personal Protective Equipment. Respiratory Protection Devices. biosecurity.he author presents a protocol for decontamination of N95 filter masks by means of short wave ultraviolet irradiation (UV-C), as well as the results of the microbiological validation testing of the UV-C device and qualitative research on the adherence of professionals from the João de Barros Barreto University Hospital, of the University Hospital Complex of the Federal University of Pará (HUJBB) to the aforementioned protocol. The microbiological tests demonstrated the efficacy of the decontamination protocol, as there was no bacterial growth in culture media inoculated with swabs of masks used in the hospital and decontaminated in the UV-C device, which proved the germicidal efficiency of UV-C irradiation. The results of the qualitative research point to the adherence of nursing professionals to the practice of mask decontamination, recognizing the practicality and contribution of the protocol to biosafety and occupational safety. As part of the same protocol, an alternative packaging for storing masks in the intervals of use of N95 masks is presented, considering their safe reuse. The protocol also has the following advantages: low cost and practicality of use, in addition to contributing to the reduction of infectious waste.Item Acesso aberto (Open Access) Eletrodeposição e caracterização de revestimento de cobre/nanotubos de carbono dopados com iodo em fios de alumínio liga 1350(Universidade Federal do Pará, 2023-09-19) RODRIGUES, Fabrício Augusto dos Santos; LEITE, Marcos Allan Reis; http://lattes.cnpq.br/8252507933374637Nanocomposites based on copper and carbon nanotubes (Cu/NTC) in metallic matrix have been providing improvements in the electrical and thermal properties of materials, presenting great potential for application in areas such as the electrical sector. Great challenges are encountered in the transmission and distribution of electrical energy, such as technical losses, mainly due to the Joule effect, resulting in low efficiency of conventional aluminum (Al) conductors. In this sense, new nanostructured conductors were developed based on functionalized copper/carbon nanotubes and doped with iodine (Cu/NTC-f), as a coating for Al 1350 aluminum wires, using the electrophoretic deposition process in copper sulfate solution, under electrical currents of 1.2 A, 1.5 A and 1.8 A, were investigated for their electrical and mechanical properties. Al@Cu/NTC-f conductors were characterized by scanning electron microscopy; X-ray diffraction; Raman spectroscopy; tensile test, in addition to electrical measurements, at room temperature and under heating, via Kelvin bridge. The results show an increase of approximately 18% of the IACS with good stability under heating compared to the commercial aluminum conductor Al 1350, due to the intrinsic properties of the NTCs, functionalization, good dispersion and the doping effect of iodine, confirmed by Raman spectroscopy with redshifts in the Gint and Gext subbands. The characteristic morphology of the thin films of Cu/NTC-f, presented pyramidal structures, agglomerates, copper structures involved the NTC, as well as NTC homogeneously electrodeposited in the aluminum substrate with good crystallinity, cultivated in the directions (311) and Cu (220), Cu (200), favoring the formation of thin films with good crystallinity. This method of electrodeposition of Cu/NTC-f on the surface of metallic wires shows promise for the production of nanostructured metallic conductors of high ampacity, thermal stability, low density and high performance, applied in electric power transmission lines.Item Acesso aberto (Open Access) Estudo da eficiência de uma turbina hidrocinética com difusor projetada para o aproveitamento da energia remanescente da barragem de Tucuruí(Universidade Federal do Pará, 2023-05-15) LIMA, Adry Kleber Ferreira de; LINS, Erb Ferreira; http://lattes.cnpq.br/5272283698536321; https://orcid.org/0000-0002-6643-5889; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975; https://orcid.org/0000-0001-6440-4811Harnessing the remaining energy downstream of dams has recently attained great attention as the kinetic energy transported by the water current is indeed considerable. This work develops a study on the performance of a horizontal-axis hydro turbine under di!user e!ect, in order to quantify the energy gain by comparing both turbines with and without di!user. A 3-bladed hydro turbine with 10 m diameter shrouded by a flanged conical di!user is employed. A numerical modeling using computational fluid dynamics is carried out based on the Reynolds Averaged Navier-Stokes formulation, using the Ÿ – Ê – SST (Shear Stress Transport) turbulence model. The results yield good agreement with experimental and theorical data available in literature.Item Acesso aberto (Open Access) Estudo das ftalocianinas metálicas na adsorção de gases do efeito estufa e poluentes utilizando docagem molecular(Universidade Federal do Pará, 2025-04-30) SOUSA, José Antonio Ferreira de; OLIVEIRA, Mozaniel Santana de; http://lattes.cnpq.br/0810227136654245; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699Atmospheric pollution, driven by the emission of toxic gases, represents an environmental and public health challenge. This study investigates the application of phthalocyanines (Pc) and metal phthalocyanines (MPc) of iron (FePc), cobalt (CoPc), copper (CuPc), zinc (ZnPc), and titanium (TiPc) for the capture of gases such as carbon dioxide (CO₂), carbon monoxide (CO), ammonia (NH₃), hydrogen cyanide (HCN), hydrogen sulfide (H₂S), and aromatic compounds like benzene (C₆H₆). AutoDock Vina 1.2.0 and Gaussian 09W were the software employed in the molecular docking technique to investigate these interactions. Gaussian 09W enabled adjustments in atomic positions to minimize the total interaction energy and build the molecular models. AutoDock Vina 1.2.0 facilitated the calculation of the most favorable binding mode between the toxic molecules and the MPc and Pc, providing detailed information on the most stable adsorption positions, orientations, and energies. The analyses indicate that MPc and Pc exhibit the best interactions with C₆H₆, while the weakest coupling occurred with H₂S. Among the evaluated substances, the best binding interactions occurred with MPc, and among them, TiPc proved to be the most efficient, exhibiting the strongest attraction to CO₂. These molecules are highly promising for the capture and elimination of the tested molecules and, consequently, constitute fundamental strategies for protecting the environment, promoting public health, and ensuring sustainable development for future generations.Item Acesso aberto (Open Access) Estudo do comportamento hidrodinâmico de medidores de vazão de gás liquefeito de petróleo utilizado a teoria do elemento de pá com efeito de grade(Universidade Federal do Pará, 2021-04-28) PEREIRA, Tiago Miranda; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975; https://orcid.org/0000-0001-6440-4811Turbine flowmeters are widely applied in industry to quantify transferred amounts of liquid products, even for commercial purposes, due to its high accuracy and large operational range. The development of engineering computational tools to analyze and improve performance of such meters offers to the engineer the possibility of contribution to society, increasing quality of measurements and minimizing distortions in supply chain potentially harmful to final consumers. Most turbine flowmeters have several blades, becoming the determination of lift and drag coefficients still challenge. This makes cascade effect indeed relevant, without which the performance of the turbine can be overestimated by the Blade Element Theory (BET) analysis. Hence, the present work proposes the application of BET to the analysis of hydrodynamic behavior of turbine flowmeters applied to Liquefied Petroleum Gas (LPG) measurement. The proposed model calculates the cascade effect correction due to the local solidity throughout turbine blades length, in order to accurately predict lift and drag coefficients at each blade section. Operational parameters of the studied equipment are obtained from the proposed computational model and compared to the field performance of an existent measurement system for several conditions within the operational range, revealing satisfactory coherence. For this analysis, computational fluid dynamics (CFD) techniques are employed, through the finite volume method. For validation of the CFD model, computational results are compared to in-situ data acquired during regular operation of the measurement system. Cavitation susceptibility is also evaluated through the CFD model, in order to provide indication of boundary limits inside which operational conditions are maintained within specifications. As a result, the study indicates that turbine flowmeter performance can be predicted by the proposed computational modeling strategy based on the BET analysis and field results of angular velocity and linearity can be accurately reproduced.Item Acesso aberto (Open Access) Estudo dos constituintes dos produtos de pirólise visando a produção de biocombustíveis e químicos(Universidade Federal do Pará, 2020-09-21) FERREIRA, Márcia de Fátima Pantoja; RIBEIRO, Nielson Fernando da Paixão; http://lattes.cnpq.br/0755443458423442; https://orcid.org/0000-0001-6145-7993; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172This work aims to use slow pyrolysis in biomass residues (EFB) as an energy potential in the production of biofuels. The raw material was obtained from agribusiness and subjected to washing, drying and crushing. The experiments were carried out in a fixed bed reactor and the central rotational composite design was used to optimize the variables temperature (459, 500, 600, 700, 741 °C) and carrier gas flow (0.259; 0.3; 0.4; 0.5 and 0.541 L/min), in order to identify the ideal conditions for obtaining bio-oil (BO). From the optimized result, the products were characterized using various techniques (FTIR, CG / MS, HPTLC, NMR, MEV, humidity, CHNO). Temperature was the most influential parameter in relation to liquid and solid yields, and the combination of variables influenced the yield in gas. There was a higher yield in BO (45.29%) whose composition showed a large amount of fatty acids, alkanes, alkenes and phenolic compounds, the latter with high antioxidant capacity. Biochar showed low yield (27.52%), but good energy capacity, the gas yield was 27.89%. The calorific value of the BO was 24.48 MJ/kg and the biochar was 19.27 MJ/kg. The results of the techniques used, prove the use of EFB as a renewable source in obtaining biofuels.Item Acesso aberto (Open Access) Extração e transesterificação do óleo de resíduo industrial de palmiste usando metanol supercrítico(Universidade Federal do Pará, 2018-11-23) COSTA, Wanessa Almeida da; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748Palm kernel is an oleaginous seed found in fruits of Elaeis guineensis Jacq. and which represents one of the main oils consumed in the world, with an mean production of 18,59 million tons. Its main process is the extraction by mechanical pressing that generates, in the world, approximately 9.6 x 109 tons of residue also called residual cake. Since this residue can still present about 12% of remaining oil, supercritical fluid extraction (SFE) is presented as an alternative to the recovery of this oil. Soxhlet extraction was also performed to be compared to the SFE. Pressures of 150, 250 and 350 bar and temperatures of 40, 60 and 80 °C were used in the experiments. The raw material was characterized before and after the SFE by moisture, ash, fibers, proteins and lipids contents and the extracts were characterized by gas chromatography/mass spectrometry (GC/MS). The kinetic data were compared to the Sovová (2012) model and the condition of highest yield was used in the transesterification experiments. Molar ratios of 1:24 and 1:42 (oil: methanol), temperatures of 250, 300 and 350 °C, constant pressure of 200 bar and reaction times of 5, 10, 15, 20 and 25 minutes were used. The products were also analyzed by GC/MS to verify the transformation of triacylglycerols into methyl esters. The main results of this study were: SFE does not alter the centesimal composition of the raw material; the condition of highest yield was 350 bar and 80 °C; Sovová's model had the best fit to the kinetic data; the condition 1:42, 350 ºC was the one that obtained the highest content of esters (99.81%) in only 5 minutes of reaction. The transesterification of palm kernel oil in a supercritical medium is a valid alternative and presents advantages over the conventional method, however a more in-depth analysis considering the technical and economic limitations of this method is necessary.Item Acesso aberto (Open Access) Interações com nanotubos de carbono e pontos quânticos de óxido de grafeno com estruturas externas do Sars-cov-2 via simulações de dinâmica e docagem molecular(Universidade Federal do Pará, 2023-06-02) LOBATO, Júlio César Mendes; OLIVEIRA, Mozaniel Santana de; http://lattes.cnpq.br/0810227136654245; https://orcid.org/0000-0002-4076-2443; CHAVES NETO, Antonio Maia de Jesus; Lattes: 3507474637884699The interaction between nanoparticles and SARS-CoV-2 virus proteins was evaluated using ligands such as single-walled carbon nanotubes (NTCPUs) and receptors including envelope protein (E-pro), major protease (M-pro) and Spike glycoprotein (Sgly). Molecular docking modeling and molecular dynamics techniques were applied. Molecular dynamics revealed root mean square shift of atomic positions ranging from 0.5Å to 3.0Å. The results indicated that the zigzag nanotube showed better affinity energy, with binding free energy values of -9.48, -9.98 and -10.08 kcal/mol for E-pro, M-pro and S-gly, respectively. Furthermore, the mean square deviation of the atomic positions remained more stable for this type of nanotube, indicating a high probability of binding to the active sites of the macromolecules. Molecular couplings and binding free energy showed strong interaction between NTCPUs and residues of the S-gly active site, with values of -112.73, -94.38 and -80.49 kcal/mol for zigzag, chiral and armchair ligands, respectively. In a second step, five graphene oxide (GO) quantum dots smaller than 20 nm were used as ligands, interacting only with the spike receptors of three different strains: S-GLY-OMICRON, S-GLY-KAPPA and S-GLY-DELTA. Comparing the two ligands, it was observed that the S-GLY-OMICRON/OG-E interaction showed better affinity with Gibbs free energy of 172.2510 KJ/mol, compared to the better affinity of carbon nanotubes, S-gly/zig-zag, with ΔG of -112.73 KJ/mol. The eight proposed ligands have a high probability of binding to the active sites of the macrostructures. In conclusion, both carbon nanotubes and OG showed promise for application in SARS-CoV-2 inhibitor products, such as the development of materials for the manufacture of personal protective equipment, sprays and waterproofing solutions in general.Item Acesso aberto (Open Access) Interações de carvão ativado, fármacos e libidibia ferrea contra o vírus SARS-COV-2(Universidade Federal do Pará, 2021-08-25) ARAÚJO, Herica Daniele Costa; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512The high rates of infection and mortality from Severe Acute Respiratory Syndrome (SARS-CoV-2) or COVID-19 infection has caused severe socio-economic impacts worldwide. Transmission basically occurs through contact with bodily fluids. In the airways, by spraying droplets and/or aerosols suspended in the environment and/or deposited on surfaces. The effectiveness of using effective masks to contain contagion is a necessity. The present work evaluated the adsorption capacity of filters containing activated carbon and modified activated carbon during nanofiltration in masks with greater efficiency. The possible interactions between Spike (S) and membrane (M) proteins with activated carbon oxygen non-modified and activated carbon oxygen modified were evaluated by docking and molecular dynamics. Autodock Vina 4.2.6 and AMBER 16 software were used in the simulations. Results of the formed ligand-receptor complexes had the affinity energy, the root mean-square deviation (RMSD) and the Gibbs free energy of binding evaluated. Activated carbon oxygen modified showed greater spontaneity in protein interactions. And, another front to combat the coronavirus was addressed in this work: the treatment of the infected, as evaluations of the inhibitory action of the active principles of retroviral drugs known in the literature, as well as new compounds from the Brazilian Amazon flora were docked with proteins S, M and envelope (E). Three drugs (Colchicine, Nafamostat and Selinexor) and three compounds originated from Libidibia ferrea or Caesalpinia ferrea (Elagic Acid, Pauferrol A and Sitosterol) interacted as ligands. And, after docking, the most favorable affinity energies of the active sites established between ligands and receptors were graphically demonstrated. The docking was carried out through the SwissDock server. The interactions of the ligands Pauferrol A and Colchicine on the proteins contained in the viral surface were highlighted.Item Acesso aberto (Open Access) Modelagem chuva-vazão-produção de sedimentos via problemas inversos(Universidade Federal do Pará, 2023-10-05) TORRES FALCÓN, Cindy; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808; https://orcid.org/0000-0001-8022-2647The development of mathematical models and direct methods has made it possible to predict hydrological phenomena such as rainfall-runoff-sediment yield. In order to complement the simulation model, inverse problems can be used to determine the properties of these phenomena and estimate parameters that cannot be measured directly. Therefore, this study was carried out in a small catchment in the Amazon with precipitation data and parameters estimated using the Kineros2 (K2) / direct model (DM). The study proposes solutions to the inverse problem (IP) characterized by the rainfall-runoff-sediment yield phenomenon for events with scarce data, with the aim of estimating the inflow rate, estimating the physical parameters, the runoff depth and the sediment yield of the basin analyzed. The sediment yield data comes from the sediment gauge station in the small catchment. For a more precise and detailed analysis of the model's behavior, combinations of information from observations and the K2 model were also carried out simultaneously with IP. The main scientific contribution is the application of the inverse problem method (Bayesian inference together with a Fourier series) to estimate the parameters of the kinematic wave model and the mass balance, and to estimate the runoff depth and sediment yield for a small watershed in the Amazon. The results showed a good fit between the observed and predicted data via IP, as Nash-Sutcliffe coefficients above 0.70 and RMSE between 0.27 and 1.99 were obtained in the calibration and validation of the rainfall-runoff-sediment yield model. The simulation of the runoff depth and sediment yield showed a 95% degree of reliability, which is consistent with the observed data.Item Acesso aberto (Open Access) Modelagem numérica-experimental da produção de sedimentos de pequenas bacias hidrográficas da Amazônia(Universidade Federal do Pará, 2021-04-22) BARBOSA, Ana Júlia Soares da Silva; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808; https://orcid.org/0000-0001-8022-2647Erosion is a process of direct impact in urban and rural environments. The understanding of this process requires the use of models and techniques of geoprocessing and field, for approximate estimation of the realized one, since it is a phenomenon with many variables to be taken into account. For the present study, two models were used to generate data in a small Amazon basin. The USLE (universal soil loss equation) and also the modified MUSLE version. For both models, the common factors (K, LS, C and P) were determined. For USLE, the calibration occurred for rain erosivity, which is the differential factor of this model. After USLE application with calibrated R factor, the model was applied to the study area with an average soil loss of 1.99 ton. ha-1.year-1, for a period of 21 years. For MUSLE, the differential variables are the hydrological variables (Q and qp) were determined by analyzing the hydrographs observed with the aid of a digital filter. Two methods of calibration and validation have been done for MUSLE. Method 1 calibrated the factors ɑ and b, with sediment production data measured from 62 flood events from 2012 to 2014. The values found for factors ɑ and b were equal to 19.90 and 0.60, respectively. MUSLE was validated with sediment production data measured from 62 flood events in the years 2014 and 2015. The validated MUSLE equation represented in a satisfactory way, in more than 70%, the data of soil loss observed in the hydrographic basin of the Igarapé da Prata. Method 2 calibrated only the value of a, using the solid discharge curve with potential regression for the years 2012 and 2013, which showed R² of 0.70 and 0.68, respectively. The value of ɑ obtained was 17.25, and was applied to MUSLE, keeping the value of b at 0.56, the original value of the model. The validation for the latter method proved to be adequate, with an R² of 0.69. These results validate the empirical models for the region with experimental activities, which corroborates for the production of sediment information in the Amazon region, as a way of maturing and the search for new research, for the understanding of the impacts arising from the transport of soil between areas and in the water environment.Item Acesso aberto (Open Access) Modelo de inteligência artificial para estimativa do desmatamento considerando a rede de transporte rodoviário do estado do Pará(Universidade Federal do Pará, 2022-01-10) NEVES, Patrícia Bittencourt Tavares das; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808; https://orcid.org/0000-0001-8022-2647; DUARTE, André Augusto Azevedo Montenegro; http://lattes.cnpq.br/1135221873341973; https://orcid.org/0000-0003-4586-1587Since the decade of 1950s the Amazonian and Brazilian transportation complex prioritized the model of road transport. Past studies point that the regular roadway system that is integrated to a clandestine roadway complex is strongly related to the Amazon forest deforestation. Thus, in this work we performed a quantitative analysis of the variables related to the process of deforestation of the Amazon forest, a natural resource of great environment and economic significance, and the socioeconomic development of the region in the period between 1988 and 2018. The geographical study area is the state of Pará, located in the Oriental Amazon, the second largest state of Brazil in territorial extension and the most devastated. We used machine learning in the modeling of the quantitative variables related to the transportation infrastructure, social variables and economic variables, e.g., the devastated area. The random forest model presented the best performance with the generated function (using least squares method). It was estimated the devastated area for the years of 2020, 2030, 2040 and 2050. Sensitivity analysis was used to evaluate the devastated area after the implementation of the roads BR-163 and BR-210 in the north of Pará. The results show that given the current scenario the devastation tends to continue intensively in the next three decades, with a 25.77% increase over the current region albeit with decreasing ten-year rates of forestation loss, and the estimation of the deforested area caused by the implementation of federal roadway networks goes from 4,703.43 km2 to 6,567.48 km2 .Item Acesso aberto (Open Access) Modelos matemáticos de transferência de calor e massa: extração de metais por membranas poliméricas e sinterização de materiais cerâmicos(Universidade Federal do Pará, 2024-07-16) VILHENA, Mailson Batista de; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505The overall objective of this work was to present a mathematical study of multicomponent mass transfer in a metal ion extraction cell through a flat polymeric membrane and to conduct an experimental and kinetic study focused on the production of synthetic aggregate from bauxite residue. In the first part of the work, a mass transfer model for the recovery of metal ions using flat polymeric membranes was developed. Unlike most existing models, which are limited to studying a single component and do not consider the selectivity and effects of multiple components on reaction kinetics, a model capable of simulating the simultaneous extraction of various metals is proposed. This model is based on the mass conservation equation and was solved using the Coupled Integral Equations Approach (CIEA), and validated with experimental measurements and previous simulations. In the second part, an experimental and theoretical study was conducted using a kinetic model for the production of coarse synthetic aggregates from bauxite residue, silica, and clay. The experimental study included the production and characterization of the aggregates in different compositions. To analyze the sintering process of a full-sized pellet, a small electric furnace with an attached balance was built, allowing the monitoring of mass loss measurements as a function of temperature and time. Additionally, a kinetic study was carried out using mathematical models to evaluate the main solid-state reactions and their phase transformations during the sintering process, using experimental data from thermal analysis.Item Acesso aberto (Open Access) Obtenção de extratos com potencial bioativo a partir da polpa do piquiá (caryocar villosum (aubl.) pers.) utilizando dióxido de carbono no estado supercrítico(Universidade Federal do Pará, 2024-09-30) CORDEIRO, Renato Macedo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580In a context of increasing demand for substances with health-beneficial properties, extracts from certain plant species found in the Amazon are a promising source of bioactive compounds. Caryocar villosum (Aubl.) Pers., a native fruit of the Amazon region commonly known as piquiá, is regarded as a source of bioactive compounds. This study investigated the supercritical extraction process of piquiá pulp to evaluate the process parameters, overall yield, extraction kinetics, fatty acid profile, α-tocopherol content, functional quality, and physicochemical characterization. The influence of extraction temperature, pressure, and solvent density on the extraction yield was considered. The quality of the obtained extracts was assessed in terms of fatty acid profile, functional quality indices, physicochemical characterization, and α-tocopherol content. A kinetic study of the piquiá extraction with supercritical fluid was conducted using experimental data and mathematical models. The extraction yield was found to increase with pressure at each isotherm, with the highest yield reaching 62.74% and the lowest at 44.01%. The kinetic mathematical models of Martinez and Barton demonstrated good performance in correlating the extraction process of piquiá pulp. The primary fatty acids observed in the extracts obtained under all operational conditions were oleic and palmitic acids. The extract obtained at the operational condition of 60 °C and 250 bar exhibited the highest α-tocopherol content compared to the other experimental conditions in this study. The results indicated that the extracts from piquiá pulp obtained through supercritical CO₂ extraction present significant potential for the industry due to their functional quality.Item Acesso aberto (Open Access) Obtenção do óleo e da polpa sem gordura do açaí (euterpe oleracea) por extração supercrítica: caracterização físico-química, estudo da citotoxicidade e vida de prateleira(Universidade Federal do Pará, 2025-01-06) SIQUEIRA, Letícia Maria Martins; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580Açaí is a very important product for the development of the state of Pará, for the bioeconomy and the market has been growing. And currently the majority of the state’s production is just fruit pulp, hence the importance of new products with added value and the need to invest in new sustainable processes for the region’s development. Therefore, the objective of this work was to obtain the oil and pulp without açaí fat by supercritical extraction, determine the main bioactive compounds, evaluate the possible cytotoxicity in MRC-5 and VERO cells in vitro and evaluate the shelf life of the products. The freezedried açaí pulp was subjected to extraction with supercritical CO2, under the conditions 323,15 K at 35 MPa, 333,15 K at 42 MPa and 343,15 K at 49 MPa. The highest yield (51,74 %), carotenoids (277,09 μg/g), DPPH (2,55 μmol TE/g), ABTS (2,60 μmol TE/g) and FRAP (15,25 μm ferrous sulfate/g) from oil and ABTS (644,23 μmol TE/g) from pulp without fat were found at 343,15 K at 49 MPa condition. The highest contents of phenolic compounds (150,20 mg GAE/g d.b.), DPPH (414,99 μmol TE/g d.b.) and FRAP (746,2 μm ferrous sulfate/g) from pulp without fat were found at 323,15 K at 35 MPa condition. The pulp without fat presented high levels of anthocyanins without significant variation. The products did not present cytotoxicity. The half-life of the freeze-dried pulp and the fat-free pulp in the presence of light (Becker) was shorter than that of the packaging materials. The sealed packaging achieved a longer half-life compared to vacuum-sealed packaging for the freeze-dried pulp. However, for the fat-free pulp, the vacuum-sealed packaging showed a longer half-life compared to the sealed one. The results of the stability of açaí oil qualify it as a table oil rather than a frying oil, as it degrades more rapidly at higher temperatures. The results demonstrated that the products have potential applications in the industry.Item Acesso aberto (Open Access) Otimização geométrica de pás de turbinas hidrocinéticas cavitantes sob efeito difusor(Universidade Federal do Pará, 2022-11-22) PICANÇO, Hamilton Pessoa; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975; https://orcid.org/0000-0001-6440-4811; LINS, Erb Ferreira; http://lattes.cnpq.br/5272283698536321; https://orcid.org/0000-0002-6643-5889Diffuser technology placed around hydrokinetic rotors may improve the conversion of the fluid’s kinetic energy into shaft power. However, rotor blades are susceptible to the phenomenon of cavitation, which can impact the overall power efficiency. This paper presents the development of a new optimization model applied to hydrokinetic blades shrouded by a diffuser. The proposed geometry optimization takes into account the effect of cavitation inception on the rotor blades surface. The main contribution of this work to the state-of-the-art is the development of an optimization procedure that takes into account the effects of diffuser efficiency, ηd, and thrust, CT d. The model uses the Blade Element Momentum Theory to seek optimized blade geometry in order to minimize or even avoid the occurrence of cavitation. The minimum pressure coefficient is used as a criterion to avoid cavitation inception. Also, a Computational Fluid Dynamics investigation was carried out to validate the model based on the Reynolds Averaged Navier-Stokes formulation, using the κ-ω Shear-Stress Transport turbulence and Rayleigh-Plesset models, to estimate cavitation by means of water vapor production. The methodology is applied to the design of a 10 m diameter hydrokinetic rotor, rated at 250 kW of output power at a flow velocity of 2.5 m/s. An analysis of the proposed model with and without a diffuser is carried out to evaluate the changes in the optimized geometry in terms of chord and twist angle distribution. It is found that the flow around a diffused-augmented hydrokinetic blade doubles the cavitation inception relative to the unshrouded case. Additionally, the proposed optimization model can completely remove the cavitation occurrence, making it a good alternative for the design of diffuser-augmented hydrokinetic blades free of cavitation.