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Evaluation of Thermal Degradation Kinetics of Hybrid Cellulose Acetate Membranes using Isoconversional Methods 等转化法评价杂化醋酸纤维素膜热降解动力学
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2022-07-15 DOI: 10.14295/vetor.v32i1.13766
Gesiane Mendonça Ferreira, Daniella da Silva Herdi, Kelly Cristine Da Silveira, M. C. Gonçalves, M. C. Andrade
{"title":"Evaluation of Thermal Degradation Kinetics of Hybrid Cellulose Acetate Membranes using Isoconversional Methods","authors":"Gesiane Mendonça Ferreira, Daniella da Silva Herdi, Kelly Cristine Da Silveira, M. C. Gonçalves, M. C. Andrade","doi":"10.14295/vetor.v32i1.13766","DOIUrl":"https://doi.org/10.14295/vetor.v32i1.13766","url":null,"abstract":"Cellulose acetate membranes are widely used in industry, emphasizing water purification processes, such as desalination. With some limiting mechanical properties, the synthesis of hybrid membranes appears as an alternative for developing high-performance materials. For its application, knowledge of thermal stability is crucial. In this work, the thermal degradation kinetics of AC-SiO2-(CH2)3NH2 hybrid cellulose acetate membranes are evaluated from thermogravimetric analysis, at three heating rates, 5, 10, and 20°C/min. The isoconversional methods proposed by Kissinger, Flynn-Wall-Ozawa, and Friedman were used for the present study of degradation kinetics. It was observed that insertion of silicon to polymeric structure promoted thermal stability to the membrane, presenting higher activation energy than pure cellulose acetate membrane, increasing from 240.28 to 1039.01 KJ/mol, using the method of Friedman. In contrast, the increase in nitrogen concentration decreases its thermal stability compared to the cellulose acetate membrane with incorporated silicon, reducing the activation energy from 1039.01 to 250.50 KJ/mol. However, it is more stable than the pure cellulose acetate membrane. The evaluation carried out in this study explained the influence of the minimum variation in the chemical composition against the thermal stability of hybrid membranes, being a factor of great importance for its application.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124368245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Parameter N Influence on the Fixed-Talbot Algorithm for the Laplace Transform Numerical Inversion 参数N对Laplace变换数值反演的Fixed-Talbot算法的影响
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2022-07-15 DOI: 10.14295/vetor.v32i1.13754
George Ricardo Libardi Calixto, E. Freitas, Juciara Alves Ferreira, B. Rodriguez, J. F. Prolo Filho
{"title":"Parameter N Influence on the Fixed-Talbot Algorithm for the Laplace Transform Numerical Inversion","authors":"George Ricardo Libardi Calixto, E. Freitas, Juciara Alves Ferreira, B. Rodriguez, J. F. Prolo Filho","doi":"10.14295/vetor.v32i1.13754","DOIUrl":"https://doi.org/10.14295/vetor.v32i1.13754","url":null,"abstract":"In this paper, Fixed-Talbot method computational aspects are explored for Laplace Transform numerical inversion and its efficiency in the treatment of a set of elementary functions of an exponential, oscillatory and logarithmic nature, based on the influence investigation of free parameter N. The numerical results are compared to the analytical solution while calculating the absolute error. The best value for N was determined in each studied function class, where the method presents satisfactory results. It was observed that increasing the number of terms in the summation for approximation (beyond the optimal value) doesn’t imply obtaining more refined results. In general, based on the data obtained, it was concluded that Fixed-Talbot method is efficient for the inversion of all classes of elementary functions evaluated in this article.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125583553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Structural Dimensioning of an Equipment to Sinter Refuse of Recycled PET 再生PET垃圾烧结设备的结构尺寸
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-19 DOI: 10.14295/vetor.v31i2.13751
Gabriel Mendes, Alexandre Scari
{"title":"Structural Dimensioning of an Equipment to Sinter Refuse of Recycled PET","authors":"Gabriel Mendes, Alexandre Scari","doi":"10.14295/vetor.v31i2.13751","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13751","url":null,"abstract":"The consumption of polyethylene terephthalate (PET) has been increasing every year, as well as its recycling process as the applications of recycled PET are diversified. However, the recycling companies are not able to recycle 100% of PET because the particles with low granulometry (refuse) are not utilized because they stick to the extruder screw and are discarded. This study presents the structural dimensioning of a proposal of an equipment to sinter this refuse in some predetermined geometries, in order to achieve possible commercial applications. This structural dimensioning was done with finite element analysis open-source software Salome Meca. Some structural modifications required to achieve the design requirements are presented. Yet, the hydraulic system to operate the compression was also dimensioned.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130526515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A remote MQTT-based data monitoring system for energy efficiency in industrial environments 用于工业环境中能源效率的基于mqtt的远程数据监控系统
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-17 DOI: 10.14295/vetor.v31i2.13726
Guilherme Balduino Lopes, Renato Ferreira Fernandes Junior.
{"title":"A remote MQTT-based data monitoring system for energy efficiency in industrial environments","authors":"Guilherme Balduino Lopes, Renato Ferreira Fernandes Junior.","doi":"10.14295/vetor.v31i2.13726","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13726","url":null,"abstract":"The concept of the new industry seeks not only to improve production processes, but also to bring solutions to environmental problems, in addition to reducing resource consumption, while maintaining high yields. This constant search for process optimization has been the main agent in the development of new technologies aimed at improving the performance of industrial production lines. Thus, this article proposes to raise some important concepts of Industry 4.0, and present the development of a remote IoT-based system that, through MQTT and Modbus protocols, will be responsible for monitoring the entire electrical network of an industrial plant, sending its data to the cloud, where it can be monitored and analyzed by the industry management sector or even by an artificial intelligence system, in a simple and effective way, in real time and from anywhere, in order to assist in decision-making focused on energy efficiency.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"585 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132669920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Soluções Numéricas de Equações Diferenciais com Redes Neurais Artificiais 人工神经网络微分方程的数值解
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-17 DOI: 10.14295/vetor.v31i2.13793
José Miguel Aroztegui, T. J. Machado
{"title":"Soluções Numéricas de Equações Diferenciais com Redes Neurais Artificiais","authors":"José Miguel Aroztegui, T. J. Machado","doi":"10.14295/vetor.v31i2.13793","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13793","url":null,"abstract":"Neste artigo, vamos estudar uma forma de resolver numericamente equações diferenciais utilizando redes neurais. Basicamente, reescrevemos a equação diferencial como um problema de otimização, onde os parâmetros associados à rede neural são otimizados. A proposta deste trabalho apresentada aqui constitui uma variação da formulação introduzida por Lagaris et al. [1], diferenciando-se principalmente na forma de construção da solução aproximada. Apesar de lidarmos apenas com equações diferenciais ordinárias de primeira e segunda ordens, os resultados numéricos mostram a eficiência do método proposto. Além disso, ele possui bastante potencial, devido a quantidade de equações diferenciais e aplicações nas quais ele pode ser utilizado.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115129539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Hardness and Texture of Electrolytic Copper Processed by ECAP at Ambient and Warm Temperature 常温和常温下ECAP处理电解铜的硬度和织构
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-17 DOI: 10.14295/vetor.v31i2.13743
Hiron Akira Yamada Magalhães, T. Souza, R. Cardoso, Bruno Rangel Silva, L. Brandão
{"title":"Hardness and Texture of Electrolytic Copper Processed by ECAP at Ambient and Warm Temperature","authors":"Hiron Akira Yamada Magalhães, T. Souza, R. Cardoso, Bruno Rangel Silva, L. Brandão","doi":"10.14295/vetor.v31i2.13743","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13743","url":null,"abstract":"Among several severe plastic deformation (SPD) methods, the Equal Channel Angular Pressing (ECAP) process is one of the most popular. This process's main characteristic is producing materials with ultra-fine or nanometric grains. Due to these microstructural changes, it is possible to improve mechanical properties such as strength and ductility. In this perspective, the aim of the present work was to evaluate the variations of the mechanical hardness property associated with microstructural and textural changes of pure copper as a function of its processing by SPD via ECAP. For this, the material was submitted to four passes through routes A (the sample is repetitively pressed without any rotation between each pass) and Bc (the sample is rotated in the same sense by 90° between each pass) at cold and warm temperatures. Through the obtained result, it was verified that the ambient temperature of the Bc route was the one that promoted greater homogeneity in the microstructure and weakening of the texture after the fourth pass. On the other hand, warm processing of copper by ECAP promoted a softening of the samples and a homogeneous distribution of hardness in both routes.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133378217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Finite Element Analysis of a Spur Gear Considering Mass Relief Strategies 考虑质量释放策略的直齿齿轮有限元分析
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-17 DOI: 10.14295/vetor.v31i2.13710
Lauro Miguel Lima Rocha, Marco Túlio Santana Alves
{"title":"Finite Element Analysis of a Spur Gear Considering Mass Relief Strategies","authors":"Lauro Miguel Lima Rocha, Marco Túlio Santana Alves","doi":"10.14295/vetor.v31i2.13710","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13710","url":null,"abstract":"This paper deals with analyzing the structural influence of mass reliefs in spur gears. For this purpose, a system composed of pinion and a gear was designed, such that for gear several geometries were designed with different reliefs shapes and soul thicknesses. From the proposed geometries, finite element analysis (FEA) was performed, and the tooth stresses of each model were compared with the solid gear. From the results, it was observed that the tooth stresses are reduced in some cases. Besides, from the aforementioned cases, it is possible to observe that the maximum stresses may take place in its core instead of the teeth (rim area). On the other hand, based on other cases, the core thickness plays an important role as a criterion that defines the local stress.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131650740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Numerical Simulation of Two-Phase Water-Oil Flow in a Horizontal Pipe Using the Smoothed Particle Hydrodynamics Method 用光滑粒子流体力学方法数值模拟水平管内两相水-油流动
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-17 DOI: 10.14295/vetor.v31i2.13761
Naim Carvalho, Grazione De Souza Boy, Helio Pedro Amaral Souto
{"title":"Numerical Simulation of Two-Phase Water-Oil Flow in a Horizontal Pipe Using the Smoothed Particle Hydrodynamics Method","authors":"Naim Carvalho, Grazione De Souza Boy, Helio Pedro Amaral Souto","doi":"10.14295/vetor.v31i2.13761","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13761","url":null,"abstract":"In this work, the numerical code DualPhysics, based on the Lagrangian particle and mesh free method Smoothed Particle Hydrodynamics, has been employed to solve the slightly compressible isothermal two-phase water-oil flow. The continuity and momentum equations are solved, and we used the modified Tait equation of state to determine the pressure. To validate the numerical code, we solved the modified Couette flow of two fluids. As a practical case, we solved the isothermal and two-dimensional two-phase water-oil flow. The mixing of the fluids occurs after passing through a 45 degree Y junction placed at the entrance of the horizontal pipeline. Results showed the potential for using the numerical code, although some modifications and alterations are still necessary to solve practical problems.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129604756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Parameter N Analysis on the Rational-Talbot Algorithm for Numerical Inversion of Laplace Transform 拉普拉斯变换数值反演的有理- talbot算法的参数N分析
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-12-17 DOI: 10.14295/vetor.v31i2.13756
E. Freitas, George Ricardo Libardi Calixto, Juciara Alves Ferreira, Bárbara Denicol do Amaral Rodriguez, J. F. Prolo Filho
{"title":"Parameter N Analysis on the Rational-Talbot Algorithm for Numerical Inversion of Laplace Transform","authors":"E. Freitas, George Ricardo Libardi Calixto, Juciara Alves Ferreira, Bárbara Denicol do Amaral Rodriguez, J. F. Prolo Filho","doi":"10.14295/vetor.v31i2.13756","DOIUrl":"https://doi.org/10.14295/vetor.v31i2.13756","url":null,"abstract":"This article investigates the numerical inversion of the Laplace Transform by the Rational-Talbot method and analyzes the influence on the variation of the free parameter N established by the technique when applied to certain functions. The set of elementary functions, for which the method is tested, has exponential and oscillatory characteristics. Based on the results obtained, it was concluded that the Rational-Talbot method is e cient for the inversion of decreasing exponential functions. At the same time, to perform the inversion process effectively for trigonometric forms, the algorithm requires a greater amount of terms in the sum. For higher values of N, the technique works well. In fact, this is observed in inverting the functions transform, that combine trigonometric and polynomial factors. The method numerical results have a good precision for the treatment of decreasing exponential functions when multiplied by trigonometric functions.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116567844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Sistema para Aquisição de Sinais de Eletrocardiograma como Ferramenta para Fins Acadêmicos 心电图信号采集系统作为学术工具
VETOR - Revista de Ciências Exatas e Engenharias Pub Date : 2021-11-18 DOI: 10.14295/vetor.v31i1.13372
Felipe Vieira Alves, Ciro Campos Chaves, Tarsila Oliveira Matos Muniz
{"title":"Sistema para Aquisição de Sinais de Eletrocardiograma como Ferramenta para Fins Acadêmicos","authors":"Felipe Vieira Alves, Ciro Campos Chaves, Tarsila Oliveira Matos Muniz","doi":"10.14295/vetor.v31i1.13372","DOIUrl":"https://doi.org/10.14295/vetor.v31i1.13372","url":null,"abstract":"Com a globalização e novos meios digitais, cada vez mais é necessário o uso da tecnologia como instrumento que venha a colaborar com a construção do conhecimento, pois tecnologia refere-se a algo que, desenvolvido, venha facilitar a realização de um trabalho, bem como viabilizar o entendimento e aplicação de uma ação. Neste trabalho, o objetivo foi desenvolver um dispositivo capaz de realizar leituras dos sinais elétricos do coração, a partir das tecnologias da eletrônica, visando a visualização da forma de onda do sinal, como também auxiliar no aprendizado acadêmico na área de engenharia elétrica e biomédica, tornando os estudantes mais familiarizados com os instrumentos e conceitos utilizados pelos profissionais da área. O projeto consiste em um circuito de aquisição, amplificação e filtragem do sinal de ECG. Foi desenvolvido um amplificador capaz de amplificar esses sinais; no entanto, os sinais estão sujeitos a ruídos aleatórios e perturbações que podem dificultar a análise de um sinal ou outro procedimento, sendo indispensável a utilização de filtros apropriados para limpar e condicionar os dados obtidos com maior eficiência e clareza em sua leitura. Os resultados obtidos na aquisição do sinal de ECG foram satisfatórios, como também foi possível desenvolver um material de fácil compreensão, para fins acadêmicos, como auxílio para toda a comunidade especifica na compreensão deste processo.","PeriodicalId":258655,"journal":{"name":"VETOR - Revista de Ciências Exatas e Engenharias","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129917578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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