A contribuition to the study of channel coding in wireless communication systems

Pós-graduação em Engenharia Elétrica - FEIS

Circulação e logística territorial: a instância do espaço e a circulação corporativa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise combinada dos efeitos dos revestimentos nas propriedades de fibras ópticas comerciais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Representação e armazenamento de dados cadastrais 3D em banco de dados geográficos

Pós-graduação em Ciências Cartográficas - FCT

Avaliação de desempenho de respostas motoras combinadas à digitação em diferentes teclados utilizados em dispositivos móveis

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Otimização de planos de manutenções de componentes de sistemas de distribuição de energia elétrica centrados em confiabilidade

Pós-graduação em Engenharia Elétrica - FEIS

Nas ondas da informação: interfaces entre o pensamento geográfico e a geografia econômica para o estudo das telecomunicações no Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise comparativa entre a produção de biogás em aterro controlado e variações no potencial elétrico natural por meio de perfilagem geofísica

This work aims to analyze data from a Natural Electric Potential landfill type ditch located in Cordeirópolis (SP). The procedure measures initially involved the assembly and installation of an apparatus cables, sensors and drain geophysical measurements and flow rate of biogas in a ditch later filled by solid waste. Biogas is a product of degradation of organic matter in waste by the action of microorganisms in an anaerobic environment. Its features high methane content in the gas potentially usable as fuel in energy generation systems or steam. The study area is characterized by clayey soil composition change from the diabase sill correlated to the event Serra Geral Formation siltstones overlapping Tatuí with groundwater level site around 50m. The cables were installed vertically in parallel with drain gas manifold, which allowed the collection of data by the technique geophysical logging every 15 days over a period of eight months. For data analysis we used four parameters in the study, the closing time of the ditch, natural electric potential, the flow velocity of biogas and rain. With the tabulated data plots were constructed for each collection day showing values in the range of the cable is in contact with waste (200 cm - 400 cm) and range of the cable in contact with the soil (600 cm - 800 cm). Subsequently graphs were generated with the period of eight months to analyze the data tabulated. A statistical correlation data, which show the influence of rainfall on the production of biogas. The results were satisfactory and demonstrated the feasibility of the research method in studies for the feasibility analysis for the capture of biogas energy

Aulas práticas para o ensino de Ciências e Biologia: algumas propostas

Os Parâmetros Curriculares Nacionais (PCNs), indicam que o ensino de ciências deve contribuir com eficiência para o desenvolvimento de uma sociedade mais esclarecida, que consiga compreender os avanços científicos e tecnológicos do mundo. Com isso, o ensino das ciências naturais pode ser articulado, apresentando-se de forma interdisciplinar, pois abrange aspectos da Física, Química, Biologia, incluindo Ciências Sociais e Tecnológicas. Focado nessa proposta, esse trabalho tem como finalidade disponibilizar ao professor de Ensino Fundamental aulas experimentais e práticas para serem utilizadas nas escolas. Consiste em uma lista de experimentos, entre outras práticas, organizados segundo os Eixos Temáticos previstos no PCNs. As práticas selecionadas se apropriam de materiais simples, de fácil obtenção e custo reduzido, podem ser realizadas tanto em ambiente laboratorial como em sala de aula, viabilizando sua utilização. Todos os experimentos foram extraídos de diferentes fontes de pesquisa: livros didáticos, apostilas didáticas e da Rede Internacional de Telecomunicação (Internet). Espera-se com esse material que o professor encontre um suporte para auxilio em aulas práticas, que proporcione ao aluno, atividades dinâmicas, facilitando a interação do educando com o conhecimento, atingindo o principal objetivo, a aprendizagem

Análise comparativa entre sistemas de resfriamento de injeção de plástico

This study aims to prove the economic feasibility of the installation of mechanical compression chillers on plastic injection molding machines in order to reduce the production cycle time of toothbrush cables in a specific case study. This evidence was confirmed by the comparative analysis of the system replaced and the new system installed. The old system had only one closed loop cooling tower which pumped chilled water to the injection molds, and the new system has the same tower sending cold water to the condensers of individual chillers installed on each injection machine. We conducted an analysis of energy efficiency in each system, showing that in terms of thermal efficiency virtually nothing has changed, but in terms of electricity demand the new system consumes 60.3 kW more. We conducted an analysis of machine productivity for both systems, showing a much higher productivity of the new system due to reduced cycle times caused by the presence of chillers and their greater cooling capacities. Equipped with data such as electricity rates, increases in operating costs and initial investments, the increase in consumption and demand of electricity plus the cycle time reduction were also calculated over so the simple payback 1 year and 2 months was reached

O risco ambiental representado por campos eletromagnéticos em Presidente Prudente (SP)

Currently the mobile services represent an essential tool in daily life of the population. However, while offering greater convenience to its users, there is growing concern about the harmful effects to human health, derived from daily exposure of the public to electromagnetic fields from radio base stations (RBS), since even today, there is no study proving that longterm exposure to low-level fields are not harmful to health. In Presidente Prudente has not been a study reporting values of measurements of electromagnetic fields from base stations installed in the city. Based on these data, this study aimed to assess the levels of electromagnetic exposure in the city of Presidente Prudente regarding recommended by international bodies, as well as propose measures that can reduce public exposure to electromagnetic fields. For measuring values of electromagnetic fields, we used appliance Electromagnetic Field Meter Portable Digital - DRE-050, the Instrutherm, following the methodology suggested and adapted from the Adilza Condessa Dode’study. In total, 49 points were mapped corresponding to the areas at risk of exposure to electromagnetic fields generated by the substations of power grid, transmission towers and telecommunication towers located in the city of Presidente Prudente (SP)

Cinética de degradação do sistema resina epóxi/fibra de carbono

With the increasing demand for electricity, the retraining of transmission lines is necessary despite environmental restrictions and crossings in densely populated areas to build new transmission and distribution lines. Solution is reuse the existent cables, replacing the old conductor cables for new cables with higher capacity power transmission, and control of sag installed. The increasing demand for electrical power has increased the electric current on the wires and therefore, it must bear out temperatures of 150°C or more, without the risk of the increasing sag beyond the established limits. In the case of long crossings or densely populated areas, sag is due to high weight of the cable on clearance. The cable type determines the weight, sag, height and the towers dimensions, which are the items that most influence the investment of the transmission line. Hence, to reduce both cost of investment and maintenance of the line, the use of a lighter cable can reduce both number and the height of the towers, with financial return on short and long term. Therefore, in order to increase the amount of transmitted energy and reduce the number of built towers and sag, is recommended in the current work substitute the current core material (steel or aluminium) for alternatives alloys or new materials, in this case a composite, which has low density, elevated stiffness (elasticity module), thus apply the pultruded carbon fiber with epoxy resin as matrix systems and perform the study of the kinetics of degradation by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC), according to their respective standards

Estudo da variação do limite de resistência à tração ao longo da bobina de vergalhão de alumínio 1350 AA

Therebar of aluminum 1350 AA produced by CBA are used inthe manufacture of wires and cables for electric power transmission, which marketshows increasingly favorableto aluminum due to itslow densityand high electrical conductivity, but to ensure that this materialmeets all specifications of projectsfor electricity transmission, it must have homogeneity in the chemicaland mechanicalproperties.One of the points of improvement in the process of rod production isreducing the high variation of the limitof tensile strengthalong the coils, therefore, this work seeks a better understanding of the factors that significantly influence the mechanical properties of rebar, specifically assessing the influence oftemperatureat the output of the coils, which can cause a recovery effect on the material andif thereare relevantdifferences between the two modes of rebar production: auto and manual.Samples of six coils have been specifically produced forthis study, which weresubsequently subjected to different annealing temperatures for one hour and ten minutes, similar to what occurs in the output of the coil from the machine. The tensile tests showed that aluminum 1350 AA is significantly influenced by temperature, whose behavior was very similar to that presented in the literature. It was found that the phenomenon of recovery occurred more significantly at high temperatures. Through the optical electron microscope Zeiss, 18 surface maps were made with 100x magnification for each sample in different conditions and the images were analyzed using entropy and fractal dimension, aiming to relate the condition of surface hardening on mechanical property of the samples in that condition. The results showed that these methods can be applied, provided they do not have any kind of imperfection on the surface, once they can influence the results. The study concluded that a more efficient cooling is required in ... (Complete abstract click electronic access below)

Transmissão de potência em corrente contínua e em corrente alternada: estudo comparativo

This paper presents a comparative study based on literature and examples in the literature, the two main technologies for the transmission of electricity at high voltage: alternate current transmission and direct current transmission. Inside the direct current transmission will be shown two technologies currently employed, transmission by current source and transmission by voltage source, contributing to a better understanding of them. The ultimate goal is to provide a text for consultation to identify key characteristics that influence the choice of future transmission lines

O uso de software para estudo de seletividade e coordenação

The present work aims to prepare a study of selectivity and coordination in an isolated electrical system with the aid of computer software PTW (Power Tools for Windows). Based on appropriate protection standards, on equipment data and the survey of the curves of “time versus current” (Time Current Curve – TCC), may be defined protection settings to leave the system selective, coordinated and properly protected. Definitions of adjustments are made taking into account the data of, so called, thermal curves of the equipment, which take into account the rated current and the supportability of short-circuit current of the equipment and cables involved in the installation in question. For that we use the tools provided by the PTW in which an industrial electrical circuit is simulated, presenting and discussing the results. With that validates the software PTW, taking it as a great tool helper implementation the coordination and selectivity study