Essa dissertação desenvolve e faz uso de uma técnica de medição com objetivo de obter dados experimentais envolvidos no ciclo de trabalho dos compressores herméticos alternativos, largamente utilizados nos sistemas de refrigeração. O trabalho mostra o comportamento das válvulas de admissão e descarga durante o funcionamento do compressor, as pressões no cilindro, na sucção, na descarga e também a variação de rotação do eixo durante um ciclo de compressão completo. Todas as características mensuradas estão referenciadas à posição angular do eixo do compressor, o que permitiu monitorar todos os eventos em função do seu deslocamento angular. Para o desenvolvimento desse trabalho foi necessário planejar um sistema de medição robusto, não vulnerável aos fatores ambientais, presentes dentro da carcaça do compressor. A limitação do espaço físico foi um fator de grande importância na escolha dos sensores, assim como a velocidade de resposta dos instrumentos, pois um ciclo de compressão tem período menor que 0,020 segundos. A coleta dos dados e a análise dos sinais foram realizadas com o auxilio de hardware apropriado e software especialmente desenvolvido. / In this dissertation it is developed and applied measurement methods to obtain experimental data of a hermetic compressor work cycle, widely used in the refrigeration systems. This work shows the suction and discharge valve behaviors, the pressure in the cylinder, as well as in the discharge and suction chambers, and also crankshaft rotation variation during a complete compression cycle. All the measurements are reference to crankshaft angular position of compressor which allows to verify the events as a function of the crankshaft angular displacement. For the development of this work it was necessary to plan a reliability measure system, not affected by environmental factors inside the housing of compressor. The inner space limitation was an important feature for choosing the sensors as well as their time response, since the period compression cycle is less than 0.020 seconds. The data acquisition and signal analysis were done with appropriate hardware and it was developed a specific software.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-16T12:04:55Z No. of bitstreams: 1 alcindogandhibarretoalmeida.pdf: 12470862 bytes, checksum: 6af9613cce2cfd9264288cf2d6202d15 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-27T21:27:55Z (GMT) No. of bitstreams: 1 alcindogandhibarretoalmeida.pdf: 12470862 bytes, checksum: 6af9613cce2cfd9264288cf2d6202d15 (MD5) / Made available in DSpace on 2016-06-27T21:27:55Z (GMT). No. of bitstreams: 1 alcindogandhibarretoalmeida.pdf: 12470862 bytes, checksum: 6af9613cce2cfd9264288cf2d6202d15 (MD5) Previous issue date: 2015-04-24 / A divergência entre o parque de iluminação pública em funcionamento e o cadastro informado pelos municípios às concessionárias de energia elétrica pode resultar numa das parcelas das chamadas perdas comerciais. O procedimento usual adotado para minimizar esse problema consiste no envio de uma equipe de técnicos a campo para a inspeção dos pontos de iluminação. Este trabalho propõe um sistema de identificação automático de lâmpadas de iluminação pública (IP), que permite às concessionárias de energia elétrica elaborar um mapa dos pontos de iluminação dos municípios, estimando o consumo e evitando perdas comerciais. Inicialmente, o trabalho aborda o cenário da iluminação pública no Brasil, incluindo as principais tecnologias usadas em IP e a transferência dos ativos de IP para os municípios. Em seguida, são descritos os principais conceitos radiométricos que caracterizam o sistema de IP. Posteriormente, é apresentada a placa de aquisição de dados construída. Essa placa contém um conjunto de nove sensores radiométricos, que medem a radiação eletromagnética proveniente das lâmpadas. Também são apresentados os projetos do firmware de controle da placa e o software de aquisição de dados. É desenvolvida uma metodologia de medição baseada em sensores de posicionamento para garantir a reprodutibilidade das medidas. Além de descrever todos esses itens, este trabalho apresenta uma estrutura de iluminação pública ajustável, que permitiu o estudo comparativo das técnicas empregadas, e uma metodologia de calibração das placas de aquisição de dados. Por fim, tem-se o sistema de classificação de dados radiométricos, que permite inferir qual lâmpada está sendo medida. É feita uma comparação de diversos tipos de classificadores. Os resultados experimentais obtidos demonstram o bom funcionamento do sistema em diversas condições de operação. / The misinformation between the actual public lighting equipment and those reported by municipalities to the electricity companies may result in a kind of loss mainly referred as commercial loss. The usual adopted procedure to minimize this problem is sending technician teams to the field to do a low effective inspection of the lighting points. This paper proposes an automatic identification system of street lighting lamps, which allows the electricity companies to draw up a map of the lighting points, estimating the consumption and avoiding commercial losses. Initially, the work addresses the scenario of public lighting in Brazil, including the main technologies used in street lighting and the transfer of the assets to municipalities. Then, the main radiometric concepts which characterize the street lighting systems are described. After data acquisition board built is presented. This board contains a set of 9 radiometric sensors which measure the electromagnetic radiation from the lamps. The projects of the firmware and the data acquisition software are also presented. A measurement methodology based on positioning sensors to ensure the reproducibility of the measurements is developed. In addition to describing all of these items, this paper presents an adjustable street lighting structure, which allowed the comparative study of the techniques employed, and a calibration method of data acquisition boards. Finally, the radiometric data classification system is shown, which allows us to infer which lamp is being measured. A comparison of various types of classifiers is made. The experimental results demonstrate the proper functioning of the system in various operating conditions.

Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-22T17:34:04Z (GMT). No. of bitstreams: 1 Machado_CintiaGoncalves_M.pdf: 16851986 bytes, checksum: d2b235b62b2caa45fabdb9df65820998 (MD5) Previous issue date: 2013 / Resumo: A injeção alternada de água e gás (WAG) configura um método mundialmente consagrado de recuperação de petróleo, no qual uma fase aquosa exerce controle de mobilidade e aumenta a área de varrido dos gases injetados no reservatório. O processo de injeção alternada de fluidos imiscíveis gera alterações irreversíveis nas curvas de permeabilidade relativa em função do efeito de histerese. Este efeito é consequente do processo e do histórico de saturações dos fluidos presentes no meio poroso. Sendo os dados de permeabilidade relativa parâmetros essenciais para a predição e gerenciamento da produção de reservatórios de petróleo, mostra-se necessário o conhecimento dos efeitos de histerese para o planejamento de projetos de injeção alternada de água e gás durante o desenvolvimento de campos petrolíferos. Este trabalho consistiu em um estudo laboratorial para investigação do efeito de histerese nas curvas de permeabilidade relativa. Os ensaios foram realizados em regime permanente e utilizou-se Tomografia Computadorizada de Raios-X para a quantificação in situ da variação das saturações dos diferentes fluidos no meio poroso durante os processos de deslocamento no meio poroso. Os deslocamentos consistiram na injeção alternada de salmoura de alta salinidade e nitrogênio em uma rocha calcária de afloramento, análoga aos reservatórios do Pré-Sal, saturada com óleo e água residual. Os principais objetivos foram à avaliação dos efeitos histeréticos nas curvas de permeabilidade relativa e a obtenção de parâmetros a serem utilizados em modelos numéricos para simulação de reservatórios. Efeitos histeréticos foram observados tanto nas curvas de permeabilidade relativa ao gás como nas relativas à salmoura. Estes efeitos foram atribuídos principalmente ao aprisionamento de gás no meio poroso ao longo dos ciclos de injeção. Observou-se também que a saturação residual de óleo se reduziu consideravelmente, ao longo da realização dos ciclos / Abstract: Water-alternating-gas (WAG) injection is a useful configuration for enhanced oil recovery (EOR). WAG consists in the improvement of the mobility control and areal sweep by cyclic injection of gas and water and it has been successfully applied worldwide. Application of WAG to carbonate reservoir has produced non-reversible changes in the permeability curves during the injection cycles in consequence of saturation path and history, which are assigned as permeability hysteresis. Consequently, hysteresis parameters obtained from experimental investigations are often required to adjust hysteresis models and to allow the improvement of the oil recovery prediction. This work reports a laboratorial investigation on relative permeability hysteresis during alternating injection of high salinity brine and nitrogen into an oil saturated carbonate core, analog to the reservoir rocks of Brazilian Pre-salt, under steady-state conditions. X-Ray Computed Tomography (CT) was applied to obtain a multiphasic quantitative analysis of the fluid in-situ saturations in the porous media. Main targets were to evaluate the permeability hysteresis and to assess the parameters to be applied in models of relative permeability hysteresis for numerical simulation. Hysteresis effects on the relative permeability curves were observed in each cycle. Permeability hysteresis was mainly attributed to gas trapping in the porous media during the injection cycles. In addition, the oil residual saturation was decreased along the successive cycles / Mestrado / Reservatórios e Gestão / Mestra em Ciências e Engenharia de Petróleo

Global economic trends suggest that there is a need to generate sustainable renewable energy to meet growing global energy demands. Solar energy harnessed by concentrated photovoltaic (CPV) systems has a potential for strong contributions to future energy supplies. However, as a relatively new technology, there is still a need for considerable research into the relationship between the technology and the solar resource. Research into CPV systems was carried out at the University of Ottawa’s Solar Cells and Nanostructured Device Laboratory (SUNLAB), focusing on the acquisition and assessment of meteorological and local solar resource datasets as inputs to more complex system (cell) models for energy yield assessment. An algorithm aimed at estimating the spectral profile of direct normal irradiance (DNI) was created. The algorithm was designed to use easily sourced low resolution meteorological datasets, temporal band pass filter measurement and an atmospheric radiative transfer model to determine a location specific solar spectrum. Its core design involved the use of an optical depth parameterization algorithm based on a published objective regression algorithm. Initial results showed a spectral agreement that corresponds to 0.56% photo-current difference in a modeled CPV cell when compared to measured spectrum. The common procedures and datasets used for long term CPV energy yield assessment was investigated. The aim was to quantitatively de-convolute various factors, especially meteorological factors responsible for error bias in CPV energy yield evaluation. Over the time period from June 2011 to August 2012, the analysis found that neglecting spectral variations resulted in a ~2% overestimation of energy yields. It was shown that clouds have the dominant impact on CPV energy yields, at the 60% level.

Orientadores: Sandra Lucia da Cruz, João A. F. R. Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-07-31T22:23:21Z (GMT). No. of bitstreams: 1 Souza_ArlanLucasde_D.pdf: 3739716 bytes, checksum: 40314e4f8359d3c06b6df822abda9f09 (MD5) Previous issue date: 2002 / Resumo: Uma nova técnica de detecção de vazamentos em tubulação é apresenta­da. A técnica é baseada na análise espectral de sinais de pressão medidos em trechos da tubulação que favorecem a formação de ondas estacionárias. Sendo baseada no espectro do sinal, e não na sua representação temporal, a análise possibilita a identificação do vazamento mesmo quando este ocorre durante a realização de operações que naturalmente encobririam o transiente de pressão gerado pelo vazamento. Testes experimentais foram realizados numa tubulação de 1250 m de comprimento em várias condições de fluxo e configurações de vazamento durante a partida e a parada de uma bomba centrífuga. Transientes de pressão foram obtidos por quatro transdutores conectados a um computador padrão PC comandado por um software de aquisição de dados e controle desenvolvido. Os testes mostraram que a análise espectral dos transientes de pressão, juntamente com o conhecimento dos pontos de reflexão na tubulação, consiste em um método simples e eficiente de se detectar vazamentos / Abstract: The development and test of a technique for leak detection in pipelines is presented. The technique is based on the spectral analysis of pressure signals measured in pipeline sections where the formation of stationary waves is favoured, allowing leakage detection during the start stop of pumps. Experimental tests were performed in a 1250 m long pipeline for various operational conditions of the pipeline (liquid flow rate and leakage configuration). Pressure transients were obtained by four transducers connected to a PC compute. The obtained results show that the spectral analysis of pressure transients, together with the knowledge of reflection points provide a simple and efficient way of identifying leaks during the start stop of pumps in pipelines / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

Subject of this effort is development and realization of one-channel data acquisition unit of mechanical quantities and it’s PC software application. Usage of this data acquisition unit is aimed on applications, where resistive strain gages wired as Wheatstone bridge with AC excitation are used. Output voltage of Wheatstone bridge is amplięed, demodulated with excitation voltage, filtered and level shifted for analog to digital conversion via AD converter. Converted digital data are sent via serial bus into microprocessor which sends them into PC for further meaningful representation in software application. Besides sensing bridge output voltage, data acquisition unit also generates AC excitation of Wheatstone bridge. This excitation voltage is generated via DA converter which communicates with microprocessor and converts incoming digital data into analog sine waveform. There is precise voltage reference circuitry for both of these converters. PC application’s task is to visualize measured data in meaningful form and to give tools for further work with measured data. It’s programmed in Python language and it has one independent thread which does reading and computing of incoming data and there is also class which builds graphical user interface and plots measured data into live graph.

This master’s thesis is mainly focused on creating our own car driving simulator and basic data gathering from the driver’s input. To achieve this goal, the thesis includes introduction to man-machine systems and basic information about functions and runtime game engine employs. Research about commonly used open source game engines is also presented with a detailed focus on the engine we chose - Unreal Engine. In conclusion ofthis thesis, a full version of a car driving simulator is created with gathered data analysis.

The master thesis focuses on the design and implementation of data collection from production using a PLC into an SQL database located in the cloud and subsequent visualization. The work describes the applicable communication protocols MQTT and OPC UA with the fact that the protocol MQTT was selected. It deals with securing data transfer from the line to the cloud using the TLS protocol. The individual cloud services and their possibilities for data collection are described here. The work deals with the possibilities of data visualization using existing open source solutions and the differences between them. I describe the possibilities of modifying the open source environment of the Grafany project. Real dashboards from production are presented. The data collection system was deployed in two plants for testing.

The goal of the diploma thesis is to develop application for data acquisition and analysis during the measurement of electrical consumption at mechanical machines. First part of the diploma thesis is providing general summary about the methods of measuring the electrical consumption. Special focus is given on methods of the metering electrical consumption in three-phase distribution network. Furthermore, the data acquisition components are being described. Hardware components and development environment LabVIEW where the program itself was created are detailly described.

Remote data collection systems are widely used. One of the area is also data collection in energetics, where the energy consumption can be collected daily and presented to users on-line. The advantage of the remote data collection is possibility of frequent readings without a physical presence at the electrometers. The data transmission over the Internet can be subject of various attacks, which is the disadvantage. The understanding of attack method is the most important thing. The protection against the hackers is not complicated, but requires lot of attention. This master's thesis is focused on testing security of the communication unit LAN of remote data acquisition against attacks from the Internet. The next aim of this thesis is to describe algorithm of particular attack, needed recourses for their realization and method of their measurement and evaluation. Communication unit and component composition for attacks simulation is described in the first part of this thesis. The next part is focused on scanning for hosts and ports. The main part of this thesis is focused on the denial of service attacks and man in the middle attacks. In the end of my thesis is described selection of cryptographic system for remote data acquisition and is showed possibility of authentication mirroring. Problems of physical security are described too. The result of this thesis is script implementing all attacks, which are described.