Navegando por Autor "Feitor, Michelle Cerqueira"
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TCC Desenvolvimento de um sistema de controle de ordens de serviço para o setor de manutenção de uma indústria têxtil(Universidade Federal do Rio Grande do Norte, 2022-02-22) Lima, Raissa Sousa de; Costa, Thércio Henrique de Carvalho; Lima, Luiz Henrique Pinheiro de; Feitor, Michelle CerqueiraCom o crescente desenvolvimento tecnológico as indústrias estão cada vez mais complexas e automatizadas. Isso de certa forma sugere que os setores de manutenção precisam estar sempre em constante busca por melhorias. Pensando nisso este trabalho de conclusão de curso foi desenvolvido com o objetivo de elaborar uma proposta de um sistema de controle de manutenção utilizando uma metodologia simples de levantamento do número de máquinas, divisão por grupos, criação de formulários para preenchimento de ordens de serviço, alimentação de banco de dados e análise de indicadores utilizando uma ferramenta de fácil acesso como o Microsoft Excel. Tornando possível a criação de um histórico que pode ser facilmente consultado e que serve de base para análise de alguns indicadores como a distribuição de atividades por tipo de manutenção e que futuramente possa vir a contribuir para análises mais avançadas. Chegando à conclusão de que se adotado o modelo proposto possa contribuir para as tomadas de decisões da área, no que diz respeito a gestão de manutenção.Artigo Optical-electrical properties and thickness analysis of TiO2 thin films obtained by magnetron sputtering(Springer Science and Business Media LLC, 2020-09-23) Feitor, Michelle Cerqueira; S. Sobrinho, V. S.; Miranda Neto, José Queiroz de; Lima, L. L. F.; Souza, Iedo A; Libório, Maxwell Santana; Queiroz, José César Augusto de; Sousa, Rômulo Ribeiro Magalhães de; Almeida, Érika Oliveira de; Costa, Thércio Henrique de CarvalhoThe study of thin films with properties that meet specific needs and improve people’s quality of life has been the focus of many researchers. However, knowing and controlling the production techniques of these films have been a challenge for the industry of optical-electronic devices, functional coatings, and energy conservation. The thickness of thin films is a parameter that influences the optical and electrical characteristics of these materials, thus being one of the most important information in the plasma deposition process. Because of the need for precision in measuring the thickness of thin transparent films, this work proposes to evaluate the Swanepoel methods (envelope) and the PUMA, computational method, from optical transmittance curves and compare them with the measurements directly made by microscopy. Scanning electronics for thin films of TiO2 deposited by magnetron sputtering in different conditions. The results of this study showed that the PUMA method is capable of calculating film thicknesses of a few hundred nanometers and with few interference fringes. The PUMA method showed convergence with high precision for films produced with 30 and 60 min of treatment and a difference of 17% for films with 120 min of deposition concerning the measurements made by microscopyArtigo Structural and optical properties of ZnO: Al thin films produced by magnetron sputtering with different oxygen flow: an experimental and Ab initio study(Wiley, 2020-08-05) Feitor, Michelle Cerqueira; Queiroz, José César Augusto de; Azevedo Filho, João Batista de; Libório, Maxwell Santana; Santos, Edson José da Costa; Souto, Ulisses Borges; Sousa, Rômulo Ribeiro Magalhães de; Costa, Thércio Henrique de CarvalhoThis work addresses, in an experimental and theoretical way, the influence of different oxygen pressure values on the physical and electronic properties of thin conductive and transparent oxide films of Al-doped ZnO, with different thicknesses. A series of characterization techniques, which include X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), optical spectrophotometry, and Hall measurements are conducted. All films have a hexagonal wurtzite structure characteristic of ZnO, with preferential orientation along the plane (002) and transmittance values, in the visible range, greater than 80%. The increase in flow oxygen up to 25% provides an increase in the film’s density resulting in a decrease in electrical resistivity from 9.58 103 Ω cm to 8.14 103 Ω cm. The ab initio calculations allow to observe the distortions in the microstructure of the films attributed to the presence of impurities and to obtain the values of the total and formation energies. The values of the Mulliken population and chemical bond length are notoriously influenced by the concentration of oxygen in the atmosphere. The displacement of the valence band (VB) and the Fermi level, together with the decrease in the gap energy, reinforce the influence of oxygen gas on the electronic structure of the films