Navegando por Autor "OLIVEIRA, Roberto Célio Limão de"

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Análise do Tratamento de Resíduos Oleosos com Reaproveitamento de Borra de Óleo Pesado em Termelétricas
(Instituto de Tecnologia, 2011) SILVA, Wagner Ferreira; OLIVEIRA, Roberto Célio Limão de
The main objective of this work is to evaluate a technology to transform oily residue into distinct liquids, water and oil, whose water can be separated and disposed within tolerable legal limits and the treated oil returned to the power generation process. The study was conducted in two power plants in Manaus, Brazil, between 2009 and 2011. Laboratory analyses and bibliographic research were carried out to validate the use of oily residues and incorporate innovative technical concepts that would enable the design of a treatment prototype. The developed prototype aims to remove impurities and mixed water, returning the oil to a viable product for reuse as fuel in electricity generation.
Análise do Tratamento de Resíduos Oleosos com Reaproveitamento de Borra de Óleo Pesado em Termelétricas
(Universidade Federal do Pará, 2011) SILVA, Wagner Ferreira; OLIVEIRA, Roberto Célio Limão de
The main objective of this work is to evaluate a technology to transform oily waste into distinct liquids, water and oil, where the water can be separated and disposed of within tolerable legal limits and the treated oil can be reused in the power generation process. The study was conducted in two power plants in Manaus, Brazil, between 2009 and 2011. Field evaluations, characterization of oily waste and fuel oil, laboratory analyses, and a literature review were conducted. The study proposes a treatment prototype aimed at removing impurities and mixed water, returning the oil to viable characteristics for reuse as fuel in electricity generation.
Análise Ergonômica no Posto de Trabalho numa Linha de Produção Utilizando Método NIOSH – Um Estudo de Caso no Pólo Industrial de Manaus
(Universidade Federal do Pará, 2011) AGAHNEJAD, Payman; OLIVEIRA, Roberto Célio Limão de
This study aims to conduct an ergonomic analysis in a production line, focusing on work biomechanics and manual handling of loads. Through research, analysis of reports, and procedures, proposals were formulated to reduce the impact of work on employee health. The method used consisted of collecting real production data, analyzing similar cases, and mathematical calculations. The conclusions indicate the need to implement actions aimed at improving the work area with appropriate equipment, benefiting both the employee and the employer.
Aplicação da Lógica Difusa para Avaliação de Maturidade de Processos de TI: Um Estudo de Caso
(Universidade Federal do Pará, 2012) FERREIRA, Heleno dos Santos; OLIVEIRA, Roberto Célio Limão de
This study presents how to use fuzzy logic to reduce the subjectivity in the evaluation of IT process maturity, allowing for a more precise quantification of subjective analyses. Initially, the work addresses the theoretical foundation of fuzzy logic and the maturity model for IT processes described in the CobiT® 4.1 framework. Then, it demonstrates that the application of fuzzy logic as a tool for analyzing IT process maturity in a company allows for an analytical model that captures results through simple observations and interviews, quantifying them to provide the overall maturity level of the process more accurately than an empirical analysis. The work presents a practical example of maturity analysis of processes related to information security in an IT service provider company. The proposed model can be adopted by organizations to provide accurate information that helps direct efforts to improve processes with lower maturity levels, adding value to the organization and the services offered to customers.
Aplicação da Manutenção Autônoma Proporcionando Ganho de Produção: Estudo de Caso no Polo Industrial de Manaus
(Universidade Federal do Pará, 2012) GOMES, Paulo Cesar Rocha; OLIVEIRA, Roberto Célio Limão de
Globalization has forced companies to continuously seek improvements in their processes to remain competitive. Maintenance, especially autonomous maintenance, plays a crucial role in this context, aiming to reduce production line stoppages and increase productivity. This work proposes the application of autonomous maintenance in a refrigerant gas leak detection system in an air conditioning production line at the Manaus Industrial Pole. The study identified that most stoppages were caused by dirt in the system filters and proposed simple solutions, such as regular cleaning and the installation of pre-filters, which reduced failures by more than 85%. Autonomous maintenance proved effective by involving operators in preventive maintenance, increasing equipment availability, and reducing costs.
AUTENTICAÇÃO BIOMÉTRICA BASEADA NA DINÂMICA DA DIGITAÇÃO EM APARELHOS DE TELEFONIA MÓVEL
(Universidade Federal do Pará, 2012) MATTOS, Edma Valléria Cunha Urtiga de; OLIVEIRA, Roberto Célio Limão de
This paper proposes a new approach to biometric authentication based on keystroke dynamics in mobile devices. The methodology is easily accessible and can be used by anyone familiar with mobile phones. Users store their information in the system, creating an access account. During password entry, the system tracks the time taken to press and release keys and compares these parameters with stored data. If the patterns match, the user is authenticated; otherwise, access is denied. The study analyzed parameters such as input capture time, individual user models, and ideal thresholds. This approach enhances security, ensuring that even if an impostor knows the password, only the legitimate user can gain access.
Autenticação Biométrica Baseada na Dinâmica da Digitação em Aparelhos de Telefonia Móvel
(Universidade Federal do Pará, 2012) MATTOS, Edma Valléria Cunha Urtiga de; OLIVEIRA, Roberto Célio Limão de
This paper proposes a new approach to biometric authentication of users based on the dynamics of typing on mobile telephony equipment. The methodology is easily accessible and may be used by anyone who knows how to handle a mobile device. The system captures the time it takes the user to press and release the keys during typing and compares it with stored parameters. If the result matches the registered data, the user is authenticated; otherwise, access is blocked. This approach provides greater security in the authentication process on mobile devices.
Estudio de la influencia del ciclo de arranques y paradas en el estator de generadores síncronicos
(INSTITUTO DE TECNOLOGIA, 2013) SANTOS, Renato Lélio da Silva; OLIVEIRA, Roberto Célio Limão de; LEITE, Jandecy Cabral; AZEVEDO, Manoel Socorro Santos; ESTEVES, Anderson Fernandes; MACIEL, Paulo Henrique de Lima; MAGALHÃES, Edilson Marques
Synchronous generators undergo frequent start-stop cycles due to maintenance or external factors, causing thermal variations that affect stator insulation. This study, conducted at the Balbina hydroelectric plant in Amazonas, Brazil, examines insulation aging trends in stators through partial discharge testing. Results indicate that continuous operation increases the generators’ lifespan.
Frequency scan on a phase-coordinates frame for unbalanced systems
(INSTITUTO DE TECNOLOGIA, 2012) LEITE, Jandecy Cabral; ABRIL, Ignacio Perez; TOSTES, Maria Emília de Lima; OLIVEIRA, Roberto Célio Limão de; Prof Dr. Walter Barra Junior
This paper presents a method for analyzing unbalanced electric networks using the frequency scan technique in a phase-coordinates frame. The developed model accurately represents unbalanced networks, such as distribution systems with asymmetric transformer banks, single-phase loads, and non-linear elements. The method is implemented in Matlab and tested on a four-wire delta system, demonstrating its effectiveness in identifying resonances and analyzing harmonics.
Metodologia de diagnóstico de manutenção baseada em condição de enrolamentos estatóricos em hidrogeradores
(INSTITUTO DE TECNOLOGIA, 2010) SANTOS, Renato Lelio da Silva; OLIVEIRA, Roberto Célio Limão de; LEITE, Jandecy Cabral; Edilson Marques Magalhães
This paper presents a methodology applied at the Balbina Hydroelectric Power Plant to diagnose faults in stator windings of hydro generators, using partial discharge monitoring as a predictive maintenance tool. This technique enables the identification of insulation deterioration and supports decision-making based on reliable data, reducing costs, increasing reliability, and avoiding unnecessary maintenance. The methodology allows for more effective maintenance planning, extending equipment lifespan.
Modelo para Análise de Negociação em Projetos de Sistemas em uma Fábrica de Software Baseado em Pontos de Caso de Uso
(Universidade Federal do Pará, 2011) MACIEL, Paulo Henrique de Lima; OLIVEIRA, Roberto Célio Limão de
The systems modeling are being increasingly applied in the means of production for many different purposes, including the area of System Design, in order to set the number of people on the team, analyze the effort, software size and total project costs. This study aims to develop a model to support analysis based on Use Case Points (PCU). For this, we use various research methods including the exploratory research laboratory to create a model of support for analysis.
O Estudo da Influência do Ciclo de Partidas e Paradas no Estator de Geradores Síncronos
(Universidade Federal do Pará, 2011) SANTOS, Renato Lélio da Silva; OLIVEIRA, Roberto Célio Limão de
Synchronous generators are subjected to different stop situations, such as forced shutdowns, shutdowns due to external conditions, and scheduled shutdowns for corrective and preventive maintenance. The temperature variations to which the synchronous generator is subjected, especially in the stator, affect its insulation, which does not keep up with these constant changes due to different expansion coefficients. This work seeks to identify a trend in the progression of aging of the insulation of stator windings in machines that undergo repetitive starts and stops and remain with their reserve power off for many hours. The study was applied to the five synchronous generators of the Balbina hydroelectric plant, belonging to the Eletrobrás group, which presents this problem. This study confirms the partial discharge analysis tests of synchronous generators carried out periodically to diagnose problems in their stator windings that present different magnitudes and confirms the hypothesis that machines that present higher magnitudes of partial discharges in their stators are those that undergo more amounts of starts and stops and hours with reserve power off.
Sistema de Controle na Alimentação de Componentes SMD em Processos de Produção SMT – Estudo de Caso no Polo Industrial de Manaus
(Universidade Federal do Pará, 2012) ARAÚJO, Ulysses Silva de; OLIVEIRA, Roberto Célio Limão de
In an era of search for competitiveness, electronics manufacturing enterprises from the Manaus Industrial District (PIM) seek to optimize their processes and reduce operational failures. This dissertation demonstrates a support tool for machine operators of automatic insertion SMD components in order to reduce operational errors. This tool has been applied specifically to the needs of the manufacturing line of a factory in the Manaus Industrial District, resulting in a manufacturing environment with a minimum of failures in the feedings components, reducing the setup time between shifts and consequently increasing production capacity at the automatic insertion area.
Una metodología aplicada en la gestión de la producción utilizando la lógica difusa. Estudio de caso: en una empresa del PIM
(INSTITUTO DE TECNOLOGIA, 2014) SILVA, Wagner Ferreira; OLIVEIRA, Roberto Célio Limão de; AZEVEDO, Manoel Socorro Santos; LEITE, Jandecy Cabral; Jandecy Cabral Leite
O artigo apresenta uma metodologia baseada na lógica difusa para gestão da produção em uma empresa do Polo Industrial de Manaus (PIM). A abordagem utiliza conjuntos difusos para modelar variáveis como equilíbrio da linha, tempo de ciclo, confiabilidade e razão de falhas, visando medir a produtividade. O estudo demonstra a eficácia da simulação computacional com suporte de especialistas, proporcionando uma ferramenta científica para tomada de decisões no processo produtivo.
Utilização do Algoritmo no Controle Estatístico de Processo (CEP) e sua Confiabilidade nos Processos Industriais Aplicado em Controle de Torque: Estudo de Caso do Pólo de Duas Rodas
(Universidade Federal do Pará, 2011) ALENCAR, David Barbosa de; OLIVEIRA, Roberto Célio Limão de
The use of Statistical Process Control (SPC) is undoubtedly crucial in the production process, and competitiveness requires continuous improvement in the application of this tool. This paper aims to guide institutions and companies that want to adopt the use of computer technologies tools as SPC, presented through a simplified and affordable, the use of an algorithm. Statistical techniques can be excellent to show the degree of security required by a particular process, and here we show which tools to use in the SPC, to study and validate retrospectively the performance of understanding the production stage, we discuss the use of an algorithm for this application. The case study was applied in a two-wheel hub company, demonstrating the effectiveness of the algorithm in reducing process time and improving torque control reliability.