Navegando por Orientadores "VIEGAS, Bruno Marques"

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Acesso aberto (Open Access)
Alocação de religadores automáticos em uma subestação de energia elétrica
(Universidade Federal do Pará, 2021-09-17) NASCIMENTO, Osório Ferreira do; VIEGAS, Bruno Marques; http://lattes.cnpq.br/1196600058247902
This work aims to reduce the number of damaged reclosers and evaluate the electric power distribution process in a 69 kV substation in the city of Manaus. To achieve the objective, the allocation of reclosers was evaluated, with installation at the outputs of 13.8 kV buses, with a descriptive methodology, based on a technical literature study with specifications of equipment and substation techniques, in addition to of national and international normative standards from a construction standard of a 69 kV substation. It was found that the energized and de-energized devices performed as expected, demonstrating the possibility of adapting the reclosers to the 13.8 kV bars, operating satisfactorily within the estimated times for implementation in field equipment and commissioning with the system. Using the recloser allocation, the number of disconnections was reduced by 95.1% and the disconnection time by 94.4%. With the application of the payoff method, using the quantity of disconnections of two circuit breakers during the year 2018 and the amount spent by the company in moving a team to resolve the situation of accidental disconnections, a profit of BRL 62,252 was obtained .87 due to savings over 5 years.
Acesso aberto (Open Access)
Análise dos impactos financeiros dos serviços de impressão por outsourcing em compras governamentais
(Universidade Federal do Pará, 2022-06-24) XAVIER, Sandra Maria Lima; VIEGAS, Bruno Marques; http://lattes.cnpq.br/1196600058247902
This work aims to evaluate the financial impacts in the provision of printing service comparing the traditional methods, managed by the institution itself, and by outsourcing of printing. The print outsourcing service model has replaced the traditional model with own resources in many public and private agencies. For this study, data from a project for the acquisition of outsourcing services were used to replace the services provided by the government institution itself, so that it was possible to make a comparison between the two models: the traditional one, with the entity's own resources, and the print outsourcing. Comparisons were made through the economic analysis of the costs presented by the bidding companies, as well as the costs of the public institution. Tools were used to analyze the cost/volume/profit from the contribution margin, break-even point and operating leverage, which led to a single decision-making model, the contribution margin. After analyzing the documents related to the costs of printing services by the traditional method and by outsourcing, this study found that the outsourcing of printing is a more economical service than the traditional model, as it ensures an advantage of 130% in relation to the offer.
Acesso aberto (Open Access)
Aplicação de técnicas bayesianas no processo debiolixiviação de urânio
(Universidade Federal do Pará, 2022-04-01) CARDOSO, Altair Costa; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; VIEGAS, Bruno Marques; http://lattes.cnpq.br/1196600058247902
This work aims to study the application of Bayesian techniques, Monte Carlo methodvia Markov chain and the importance sampling filter and sequential resampling, for the estimation of kinetic parameters and state variables of the uranium bioleaching processby Acidithiobacillus ferrooxidans. To make the estimates, experimental measures of cell concentration, uranium, ferrous and ferric ion, available in the literature, were used,which were evaluated using a mathematical model composed of a system of ordinary differential equation. Different case studies were conducted involving the measurement and model deviation (1 and 5%), as well as the kinetic model of the specific speed of cell growth. The results of the estimates showed a good agreement with the experimental measurements, presenting coefficient of determination values ranging from 0.95 to 0.99. The mathematical models evaluated were validated by reproducing the experimental measures and the use of Bayesian techniques proved to be adequate.