Programa de Pós-Graduação em Engenharia de Recursos Naturais da Amazônia - PRODERNA/ITEC
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/4044
O 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), em nível de Doutorado, tem como objetivos principais: formar quadros profissionais qualificados na área de Engenharia de Recursos Naturais; incentivar a pesquisa e o aprofundamento dos estudos técnicos e científicos relacionados ao uso e a transformação de recursos naturais; e contribuir para o desenvolvimento científico e tecnológico da região Norte.
Navegar
Navegando Programa de Pós-Graduação em Engenharia de Recursos Naturais da Amazônia - PRODERNA/ITEC por Afiliação "UFPA - Universidade Federal do Pará"
Agora exibindo 1 - 20 de 30
- Resultados por página
- Opções de Ordenação
Item 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/0000-0001-9365-7498The 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.Item Acesso aberto (Open Access) Análise do processo de despolimerização de resíduos de resinas dentárias à base de pmma em diferentes escalas de produção(Universidade Federal do Pará, 2024-06-26) RIBEIRO, Haroldo Jorge da Silva; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; https://orcid.org/0000-0002-2337-4238In recent years, the increasing use of plastics has brought economic and industrial benefits but has also led to a significant rise in waste, representing a global environmental challenge. In this context, pyrolysis emerges as a promising technology, offering potential solutions to address the growing problem of plastic waste and promote a more sustainable circular economy. This study investigated the thermal decomposition of dental waste based on poly(methyl methacrylate) (PMMA), focusing on the thermodynamic characterization and optimization of pyrolysis processes at different production scales. Thermogravimetric analysis (TG) showed that PMMA waste remains stable up to 200 ºC, with degradation starting as mass loss occurs beyond this temperature. Thermal decomposition was observed to occur in a single stage, with a decomposition peak at 366 ºC, within the range of 327 ºC to 405 ºC, primarily due to radical depolymerization under inert nitrogen and argon atmospheres. Differential Scanning Calorimetry (DSC) analysis revealed an endothermic peak between 370 ºC and 433 ºC, highlighting the complexity of the pyrolysis processes. The energy characterization showed specific values of 423 J/g for total heat, 1748 J/g for gasification heat, and approximately 820 J/g for decomposition heat, indicating discrepancies that require further investigation for a more complete understanding. In studies using semi-batch fixed-bed reactors, a temperature gradient along the bed was observed to have an adverse impact on the liquid yield and MMA concentration, especially in technical and pilot scales, where the gradient was more pronounced due to the thicker bed. Two critical variables were identified: reactor load and power load, both of which decreased as the process scale increased, leading to lower pyrolysis temperatures and negatively affecting MMA production. Additionally, higher temperatures were found at the edges of the fixed bed, which increased gas production and reduced liquid yield. The liquid fraction analysis revealed a predominance of MMA at the beginning of the reaction, with a gradual transition to aromatic hydrocarbons in the final stages, associated with the pyrolysis of residual char, which increased with the scale of production. The results highlight the effectiveness of temperatures below 450 ºC in producing MMA-rich liquid fractions, even under temperature gradient conditions, emphasizing the importance of moderate heating rates for efficient PMMA depolymerization in semi-batch systems. These findings provide valuable insights for reactor design and are essential for the economic evaluation and optimization of PMMA recycling processes through pyrolysis at various production scales.Item 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) Biocompósito a partir de PLA, Biovidro e Nanotubos de Carbono por Impressão 3D visando Regeneração Óssea(Universidade Federal do Pará, 2023-03-31) VASCONCELOS, Esleane Vilela; REIS, Marcos Allan Leite; http://lattes.cnpq.br/8252507933374637; https://orcid.org/0000-0003-2226-2653; CANDIDO, Verônica Scarpini; http://lattes.cnpq.br/8274665115727809; https://orcid.org/0000-0002-3926-0403Bone involvement promoted by aging and accidents has aroused interest in biomaterials and technologies for bone regeneration purposes. Thus, 3D printing technology gained prominence in the production of scaffolds due to its versatility in the production of complex geometries with interconnected pores. In this work, scaffolds composed of poly (lactic acid) (PLA), bioglass (BV) and carbon nanotubes (NTC) were produced by 3D printing, using hexagonal geometry, similar to honeycomb, interleaved. Poly (lactic acid) is a biopolymer already used in biomaterials, while bioglass has proven to be an excellent strategy for use in bone regeneration due to its excellent properties of biocompatibility, bioactivity and osteointegration, however they have low mechanical resistance and carbon nanotubes have shown excellent mechanical reinforcement in composite biomaterials. Thus, the main objective of this study was to produce and characterize a biocomposite of PLA, bioglass and carbon nanotubes by 3D printing and to study its chemical structure, crystallineity and morphology, using fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction and scanning electron microscope. The thermal stability of the composite was evaluated by thermogravimetry, mechanical properties by compression tests and cell viability was determined by the Alamar Blue test. The bioglass was synthesized by sol-gel method presenting bioactive phases of silicate. The scaffolds were produced by 3D printing with hexagonal structures in honeycomb in PLA, PLA/BV and PLA/NTC that were impregnated with bioglass on its surface. The results of the scaffolds demonstratedinterconnected and well-defined pores, ranging from 130 μm to 800 μm. Raman spectroscopy confirmed the interaction of BV in the polymer matrix through new peaks in the spectrum between 1400 and 2600 cm-1 and the presence of the D, G and 2D bands of NTC. In the compression assay, PLA scaffolds with 2 mm diameter showed higher compression stress of 14.88 ± 2.35 MPa, while PLA/NTC higher modulus of apparent compression, 0.58 ± 0.36 GPa. In cell viability, statistical tests showed that there was no significant difference between scaffolds with 2 and 4 mm diameter. The results reveal promising results for the use of 3D printed composites in bone repair sponges. Thus, we suggest the composite of PLA/NTC of 4mm impregnated with BV on the surface as the best bone substitute, however, the application in implants remains limited in relation to osteogenic integration.Item Acesso aberto (Open Access) Concentração e bioensaios alelopáticos e antifúngicos de princípios ativos da raiz de timbó via extração com CO2 supercrítico, extração com solventes e adsorção de soluções diluídas em leito fixo.(Universidade Federal do Pará, 2014-12-18) ALMEIDA, Ossalin; ARAÚJO, Marilena Emmi; MACHADO, Nélio TeixeiraItem Acesso aberto (Open Access) Custo de oportunidade (trade-off) para diferentes estratégias de manutenção de trilhos ferroviários na Amazônia(Universidade Federal do Pará, 2022-12-22) CURCINO, Gabrielle dos Anjos; BRAGA, Eduardo de Magalhães; http://lattes.cnpq.br/4783553888547500The emergency maintenance of railway assets in the Brazilian Amazon has generated revenue losses and opportunity costs. The general objective of this study was to identify the importance of opportunity cost in decision-making for corrective and preventive maintenance strategies. The methodology proposed the modeling of the variables referring to the economic and operational data of railway maintenance in the last ten years, by non-parametric Gradient Boosting Regression Tree machine learning, and hybridizing it with the analysis of the opportunity cost for the trade-off decision making of an ore railroad in the Brazilian Amazon. The results showed that the GBDT was efficient in fitting the training data with r2 equal to one. Similarly, the test data presented satisfactory r2 values, close to one, where the degree of importance of the independent variables in the prediction of the dependent variables was obtained. Pearson's method was used to construct the correlation matrix for each pair of variables. From the generated model, eight forecast groups were created for the year 2022. Then, conflict levels were established, suggested by the economic literature, between the forecast scenarios, where the opportunity cost was identified among the alternatives with the best benefit to maintenance strategies. In this way, the opportunity cost combined with machine learning serves as an instrument to help companies in the search for better maintenance decisions, which contributes to the improvement of rail asset management.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) Desenvolvimento de ligas de alumínio nanoestruturadas para a utilização em cabos elétricos(Universidade Federal do Pará, 2023-03-15) PRAZERES, Emerson Rodrigues; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; BRAGA, Eduardo de Magalhães; http://lattes.cnpq.br/4783553888547500Aluminum nanocomposites demonstrate the ability to improve mechanical properties, thermal and electrical conductivity. For aluminum, the incorporation of multi-walled carbon nanotubes (NTCPM) using conventional melting methods is an old problem, due to disintegration of the walls of carbon nanotubes when subjected to high temperatures. In this study, aluminum nanocomposites were manufactured by the conventional casting method, using stainless steel powder (304LSS), nanostructured silicon and nickel. The carbon nanotubes were treated with hydrogen peroxide, allowing adhesion by polar interaction with the particles of the metallic powders. The nanostructured compounds were added to the aluminum matrix by means of conventional casting. After obtaining the material as a melt, it went through the machining process to a diameter of 18.5 mm and then through the cold working process until a diameter of 3.0 mm was obtained. The alloys were characterized mechanically through tensile and microhardness tests, electrically through electrical resistance tests, using a 2-point kelvin bridge, and structurally through macrostructure and microstructure analyses. The 304LSS powder added alloying elements, refined the grains and the NTC improved electrical conductor performance, with electrical conductivity gains in the range of 10%. Associates associated with carbon-associated components not linked to chains of protein chains are compounds of carbon, associated with proteins, aggregates, associated with carbon, associated with proteins, associated with significant proteins in the LRT. The alloys with Ni and carbon nanotubes contributed to significant gains in electrical conductivity and LRT, with the alloy with 2% nickel and 0.1% NTC showing gains of approximately 8% in electrical and mechanical properties. Nanostructured alloys were also superior in terms of electrical and mechanical properties than commercial alloys.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 de processo de upgrading catalítico de vapores da pirólise de resíduos plásticos de equipamentos de informática em reator catalítico com carvão ativado impregnado com NaOH(Universidade Federal do Pará, 2023-04-03) COSTA, Augusto Fernando de Freitas; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065This study investigated thermal cracking and catalytic upgrading of plastic waste from computer equipment on a semi-batch reactor coupled to a heated catalyst fixed bed (2-stage vapor cracking). The catalyst used was a Si–Al ash obtained from commercial activated carbon pellets treated with concentrated NaOH solution and calcination. The purpose of the study was to characterize the waste stream through its thermogravimetry (TG) analysis and pyrolysis products, study the effect of temperature (350 - 500 °C) and catalyst quantity (0.0 - 7.5 wt%) on yields of reaction products, physical chemical properties, and chemical composition of organic liquid product in order to understand and evaluate production of fuels and chemical feedstock by recycling of plastic waste from computer equipment through catalytic upgrading. Time fractioned samples were taken in determined reaction times (15 min, 30 min, 45 min, and 60 min) to study the evolution of cracking reactions during experiment runs through changes to chemical composition (GC-MS). A comparison with other previous work was also presented to show similarities between different feedstocks using the same thermal unit. The results indicate composition of brominated acrylonitrile-butadiene-styrene (Br-ABS), polycarbonate (PC), and high impact polystyrene (HIPS) for the plastic waste from computer equipment. The temperature of 350 °C produced better results when considering acid value but presented lower liquid phase yields (38 %) and high gas phase yields (42 %). Catalytic upgrading experiments revealed the increased presence of polycyclic aromatic hydrocarbons (PAH) with an increase in kinematic viscosity of organic liquid product, increase in char yield (from 11 % to 24 %), and decrease in gas yields (15 % to 5 %). Chemical composition showed presence of aromatic hydrocarbons such as styrene, methyl-styrene, and diphenyl-propane and nitrogenated compounds such as benzene butane-nitrile, phenolic compounds, polycyclic aromatic hydrocarbons, and brominated compounds. Plastic waste from computer equipment pyrolysis is a challenging subject due to contaminant presence and varying composition, and chemical composition evaluation according to reaction time provides interesting insights into the evolution of semi-batch pyrolysis/catalytic upgrading experiments. Standardization and reproducibility of the tool should be conducted to continue the evaluation of pyrolysis and catalytic upgrading of a wide range of feedstocks.Item Acesso aberto (Open Access) Estudo do processo de depolimerização de resíduos de resinas dentárias de polimetilmetacrilato (PMMA) via pirólise(Universidade Federal do Pará, 2022-01-05) SANTOS JUNIOR, Paulo Bisi dos; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065Polymer materials, due to the diversity of their properties, ease of processing and ability to replace traditional materials, have become indispensable in modern society, although the growing accumulation of plastic waste has become a relevant problem that is difficult to manage. Given this situation, sustainability research has invested in new strategies focused on the processing and transformation of plastic waste where the pyrolysis process presents itself as a promising technology. In this work, the cross-linked PMMA-based dental resins scraps submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps analyzed by TG/DTG to guide the operating conditions. The pyrolysis carried out in a reactor of 143L, at 345, 405, and 420 °C, 1.0 atm. The reaction liquid products obtained at 345 °C, 30, 40, 50, 60, 70, 80, and 110 minutes, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of reaction liquid products obtained at 354 °C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405 °C, 50, 70, and 130 minutes, and at 420°C, 40, 60, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420 °C, respectively, showing a smooth sigmoid behavior, decreasing with increasing process temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The reaction liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage errors between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA (Methylmetaclylate) at 20 °C. The GC-MS identified in the reaction liquid products during pyrolysis at 345, 405, and 420 °C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA (Methylmetaclylate) between 83.454 and 98.975% (area.). For all the depolymerization kinetic experiments at 345, 405, and 420 °C, 1.0 atm, the concentrations of MMA (Methylmetaclylate) in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA (Methylmethaclylate).Item Acesso aberto (Open Access) Estudo do processo de upgrading catalítico de vapores da pirólise de gordura residual em reator de leito fixo com catalisador carvão ativado impregnado com NAOH(Universidade Federal do Pará, 2022-08-17) BERNAR, Lucas Pinto; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456This work investigated influence of reaction time and catalyst-to-residual fat ratio by catalytic upgrading from pyrolysis vapors of residual fat at 400 °C and 1.0 atmosphere, on the yields of reaction products, physicochemical properties (density, kinematic viscosity, and acid value) and chemical composition of bio-oils, over a catalyst fixed bed reactor of activated carbon pellets impregnated with 10.0 M NaOH, in semi pilot scale. The experiments were carried out at 400 °C and 1.0 atmosphere, using a process schema consisting of a thermal cracking reactor of 2.0 L coupled to a catalyst fixed bed reactor of 53 mL, without catalyst and using 5.0, 7.5, and 10.0% (wt.) activated carbon pellets impregnated with 10.0 M NaOH, in batch mode. Results show yields of bio-oil decreasing with increasing catalyst-to-feed ratio. The GC-MS of liquid reaction products identified the presence of hydrocarbons (alkanes, alkenes, ring-containing alkanes, ring-containing alkenes, and aromatics) and oxygenates (carboxylic acids, ketones, esters, alcohols, and aldehydes). Physico-chemical and compositional analysis show that cracking occurred along the carbon chain present in triglycerides and fatty acids initially present, producing gaseous hydrocarbons. Tha activated carbon catalyst was not selective for the liquid biooil deoxygenation, but the obtained results are of great value for understanding the catalytic cracking reaction mechanism.Item Acesso aberto (Open Access) Influência do uso de resíduos industriais nas propriedades mecânicas e reológicas de argamassas utilizadas na indústria da construção civil(Universidade Federal do Pará, 2019-03-21) CARDOSO, Dilson Nazareno Pereira; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/1711061955509303The general objective of this work was to develop alternative and usable materials within the construction industry, addressing a logic of recovery and reuse of solid waste, generated from construction and demolition construction sites, as well as the reuse of waste generated from the construction industry mining industry and mineral processing. Were used in the work the residue of construction (RCC), residue of sulfide copper ore (RMCS) and the waste of circulating fluidized bed boilers from the combustion of coal to fly ash (CV). The samples of these materials showed appropriate characteristics, such as recycled fine aggregate within the NBR 7211 standard. The materials were subjected to physical and chemical characterization through laser particle size analysis, x-ray fluorescence (FRX), diffraction and x-ray (DRX).). The mortars produced were studied in the free state, that is, without additives and also within the insertion of polymeric organic additive polyvinyl acetate (PVA) and Styrene Butadiene (SBR). The obtained mortars were physically characterized through the analysis of apparent porosity, water absorption, apparent specific mass and resistance to axial compression. Thermal analyzes of (TG and DTG) and scanning electron microscopy - SEM were also performed. In the fluid state rheological tests were performed to evaluate its behavior according to time (thixotropy), workability and the most representative rheological model for its flow. The developed materials presented technical properties approved by the ABNT standards, making them suitable for certain types of applications, in terms of laying and covering of walls, floors and ceramic tiles, respecting the technical characteristics of these materials.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) Manufatura aditiva de biocompósitos a partir de ácido poliláctico reforçado por hidroxiapatita e nanotubos de carbono para regeneração de tecido ósseo(Universidade Federal do Pará, 2024-01-22) BELO, Francilene da Luz; REIS, Marcos Allan Leite dos; http://lattes.cnpq.br/8252507933374637; CANDIDO, Verônica Scarpini; http://lattes.cnpq.br/8274665115727809Bone tissue is one of the most important tissues in the human body. Unfortunately, some traumatic events can cause fractures that can lead to temporary or permanent disability. Scaffolds are some of the materials that help in the treatment of these fractures, as they play an important role in the bone repair process and can be manufactured by 3D printing. Polylactic acid (PLA), as it is biodegradable, is one of the materials used in the production of scaffolds. Furthermore, the association of PLA and hydroxyapatite (HA) in its manufacture has shown excellent results, accelerating bone regeneration and reducing healing time. Another promising material for making scaffolds are carbon nanotubes (CNT), which have excellent mechanical properties and also accelerate bone growth. Thus, the main objective of this study was to produce scaffolds by additive manufacturing from polylactic acid (PLA) reinforced with hydroxyapatite (HA) and carbon nanotubes (CNT), to be applied in the regeneration of bone tissue and characterized through mechanical and biological. Hydroxyapatite was synthesized by wet means and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), presenting phases characteristic of HA, characteristic groups and a morphology with a porous surface with varying particle sizes, important characteristics for a biomaterial. The pure PLA, PLA/HA and PLA/NTC scaffolds were produced by additive manufacturing with an opening between the walls of 1 mm and 2 mm and characterized through mechanical tests and biological tests. Furthermore, PLA/NTC scaffold samples were impregnated with HA on the surface by thermal and chemical treatment to evaluate the influence of ceramics on the composite surface. The micrograph of the scaffolds showed that the addition of CNT made the PLA surface rougher compared to the sample containing HA; The TGA curves suggested that temperature may favor the thermal stability of PLA/NTC scaffolds impregnated with HA on the surface; Ramam showed an interaction between hydroxyapatite on the CNT surface and a possible structural transformation of PLA/CNT; In compression tests, PLA/NTC scaffolds with an opening between the walls of 1 mm showed better compression resistance; In cell viability assays, fibroblasts incubated with pure PLA, PLA/HA and PLA/NTC scaffolds showed high viability after evaluation by the MTT assay for the two forms of preparation (heat treatment impregnation and chemical treatment impregnation and for the two openings between the walls. More than 85% of the cells remained viable after 48h of incubation with all scaffolds tested, with the groups that had NTC in their composition showing the best results, both for heat treatment (more than 95% of cell viability) as well as chemical treatment (acetone). Given the results presented, it is concluded that PLA scaffold reinforced with HA and CNT may be promising as a biomaterial used to aid in the regeneration of bone tissue, contributing to the reduction of time hospitalization of patients suffering from bone fractures.Item Acesso aberto (Open Access) Metodologia para estimativa do valor da externalidade perda na atividade pesqueira em usinas hidrelétricas(Universidade Federal do Pará, 2019-04-22) CARVALHO, Evelyn Gabbay Alves; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808; DUARTE, André Augusto Azevedo Montenegro; http://lattes.cnpq.br/1135221873341973Item Acesso aberto (Open Access) Métodos de obtenção e caracterização de biomembrana de quitosana e copaíba para potencial uso em feridas(Universidade Federal do Pará, 2022-06-14) PARANHOS, Sheila Barbosa; PASSOS, Marcele Fonseca; http://lattes.cnpq.br/0588450144351187; https://orcid.org/0000-0002-5616-2127; CANDIDO, Verônica Scarpini; http://lattes.cnpq.br/8274665115727809; https://orcid.org/0000-0002-3926-0403Health professionals deal directly with several complex situations in the care of sick people. Among these, there are skin wounds that can harm the patient's clinical condition, in addition to costly treatment for healing. Skin wounds require dressings to protect against pathogenic microorganisms and to accelerate the healing process. With the emergence of biomaterials available for use in wound treatment, chitosan has become an effective choice, easily found in a natural and renewable form with healing potential. The chitosan membrane presents ideal conditions in the treatment of wounds, such as absorption, protection, biocompatibility and antimicrobial potential. To increase its healing effects, natural oils have been incorporated into the polymer matrix, such as copaiba, which has a high anti-inflammatory action. In this context, the work aimed to obtain and characterize chitosan membranes by emulsion and nanoemulsion of copaiba oil to treat skin wounds. The chitosan membranes with oil addition by emulsion and nanoemulsion were synthesized by the solvent evaporation technique. They were evaluated by macroscopic analysis and characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, swelling percentage, humidity, contact angle. An in vitro assay of antibacterial activity against the bacterium S.aureus was carried out. The membranes had an apparently thin appearance, little malleability, relative opacity, continuous and good handling. He observed more porosity on the surfaces of membranes synthesized by nanoemulsion of copaiba oil, in addition to a more amorphous behavior. He noticed a better interaction between chitosan and oil constituents when the oil synthesis was prepared by nanoemulsion, resulting in improved stability of the material produced. The swelling percentages were higher in the MQCoN-0.1 (214±3.22%) compositions when immersed in water and the MQCoN-5.0 composition (220±6.83%) in the PBS solution. The wetter behavior was significant in membranes composed of 0.1% (0.80±1.37%) and 0.5% (3.00 ±0.79%) copaiba oil nanoemulsions. There was no great influence on the contact angle between syntheses and compositions. The chitosan membrane with 1.0% (v/v) of emulsified oil and the chitosan membrane with 0.5% (v/v) of nanoemulsified oil were the most hydrophilic membranes. All membranes were able to inhibit bacterial growth, except the chitosan membrane with 1.0%(v/v) oil emulsion. Materials obtained by nanoemulsion have ideal attributes for application in the use of skin wounds.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) Nanofiltração de hormônios e metais pesados em nanotubos de carbono e de boro por dinâmica molecular(Universidade Federal do Pará, 2020-02-27) CAVALEIRO, Rosely Maria dos Santos; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512Sewage treatment stations receive various effluents and perform the selective filtering of molecules that can, if they persist in the water, contaminate or the environment. Selection processes initiated by larger sections down to nanoparticles. Among the molecules called emerging contaminants are hormones and heavy metals that impact on graves consequences on organisms by endocrine-disrupting action. When surface waters receive effluents with traces of contamination and hormones or heavy metals, they will cause diseases in living beings, especially in pregnant women and children, as well as interfering in the chains of DNA, also affecting the next generations. This study of molecular tests carried out with nanofiltration: water with hormones and water with heavy metals filtered through carbon nanotubes and boron nitrogen, under the action of 8 (eight) electric fields lasting 100 (hundred) ps. The study hormones were: estrone, estradiol, estriol, progesterone, ethinylestradiol, levonorgestrel, diethylbestrol, and heavy metal ions: lead, cadmium, iron, zinc, and mercury. Each of the hormone molecules and the heavy metal were filtered through two nanotubes, under the same boundary conditions. The selected results that allow creating nanofiltration systems that can be removed micropollutants using carbon nanotubes or boron nitride activated by the uniform electrical fields from 10-5 a.u. to 10-8 a.u.