O presente trabalho tem como objetivo principal o desenvolvimento de um sistema de identificação do surgimento de vazamentos (rupturas) em dutos, através da análise do sinal de sensores de pressão de resposta rápida (frequência de corte superior a 1 kHz). O reconhecimento do sinal de vazamento se realiza através de uma rede neural artificial feed-foward do tipo Perceptron Multi Camadas, previamente treinada. Neste trabalho, a implementação para tal operação foi feita off-line, mas devido ao baixo custo computacional pode ser facilmente implementada em eletrônica embarcada, em tempo real (on-line). Os resultados experimentais foram obtidos no oleoduto piloto do NETeF - Núcleo de Engenharia Térmica e Fluidos da USP - Universidade de São Paulo, com uma seção de testes com 1500 metros e diâmetro de 51,2 mm. Especificamente, os resultados foram obtidos com escoamento monofásico de água. Os resultados mostram-se promissores, visto que o sistema de redes neurais artificiais foi capaz de discriminar 2 universos linearmente separáveis, para sinais de vazamento e de não vazamento, para diversas vazões e localizações de vazamentos simulados. / The present dissertation deals with the development of a system to identify abrupt leaks (ruptures) in pipelines, by analyzing the signal of fast response pressure sensors (cutoff frequency over then 1kHz). The recognition of the leak signal is established by an artificial neural network feed-forward Perceptron Multi Layer, previously trained. In the present work the implementation was performed off-line, but due to low computational costs, the neural network can be easily implemented in real time embedded electronics (online). The experimental results were obtained in a 1500 meter-long and 51.2 millimeter-diameter pilot pipeline at the Center of Thermal Engineering and Fluids. Specifically, the results were obtained with single-phase flow of water. The results have proven to be promising, as the trained neural network was capable of classifying the 2 types of signals into 2 linearly separable regions, for leakage signals and no leakage signals, for various flow rates and locations of simulated leaks.

This thesis has been a study in memory management in C/C++, with practical work in finding and solving memory leaks in a large project. A background theory of C++ and memory management has been presented along with the memory problems that can arise in development in C/C++. Several topics in minimizing memory problems with using inbuilt C++ libraries and the Boost libraries have also been presented. There is also an overview of the PLC-Opt 2.2 Beta application and its inner workings. The method was to learn all about memory management and solve the memory leaks in PLC-Opt. The results showed that there were approximately 28.000 instances of memory leaks and the end result showed that approximately 700 instances of leaks remained unresolved. A list with clues of the remaining memory leaks was provided in the Future work chapter.

This research used an Integrated Water Resource Management approach to investigate how Water Demand Management (WDM) measures at government, utility and end-user levels could contribute to providing sustainable water supply to Bahrain, which is in an arid to semiarid region. The main driver for this research was the supply-driven orientation favoured by policy makers and practitioners in Bahrain with little consideration for demand management. This leads to a high estimated gross per capita consumption 525 l/c/d as of 2010. There was also a need to investigate the institutional environment for managing water resources and delivering sustainable water supply to Bahrain. The research adopted a case study methodology which included qualitative analysis of interviews and documents from the water authority, and quantitative analysis of questionnaire surveys and pilot studies. The research adopted a cross-sectional approach to the analysis of activities associated with WDM practice in Bahrain. All findings and conclusions were evaluated/validated using surveys distributed to water experts and customers. Based on their feedback, findings and conclusions were revised. The main finding of this research was that the tariff is highly subsidized by the government and there is no encouragement for water savings. The low tariff leads to low revenue which in turn affects the budget allocated to the relevant departments and units at the Electricity and Water Authority (EWA). This impacts negatively on their activities. It was found that there is no effective strategy for integrated water resources management; there is a high level of Non Revenue Water (NRW) (38%); and limited reuse of grey water and water use saving devices. In addition there is a lack of public awareness and understanding of the benefits of WDM among all levels of society including professionals and water supply providers. The research concluded that improving water use efficiency in Bahrain should be a priority due to the current high water supply costs. There is a need for proper legislation that enforces the use of WDM; establishment of a national WDM committee with the Water Resources Directorate, and for water resource professionals to follow WDM oriented policies. The research proposed six areas to be further investigated to achieve more efficient use of water: (a) Water tariff reform to recover full water supply costs; (b) institutional reform through activating and enforcing Water Resources Council roles; (c) promoting public awareness about WDM and its benefits; (d) reducing non revenue water; (e) applying positive economic sliding scale incentives for customers who reduce their water consumption.

An investigation into the thermo-mechanical closure effect when a fluid leaks through a crack is presented here. The extended finite element method is the modelling scheme adopted for this, and the application of heat flux and pressure jump conditions along the crack is one of the novel contributions of this work. By modelling the fluid as one dimensional steady state and obtaining a heat transfer coefficient, it has been shown here that coupling the fluid with the structure is possible all within a single element. Convergence studies done with analytical models as a benchmark demonstrate the accuracy of the new method. Simulations are performed with the new element for conditions seen in both gas cooled and water cooled reactors. Significant crack closure is observed when the bulk fluid temperature is 20oC hotter than the structure. It was also found that the amount of closure due to crack wall heating varies depending on the external boundary conditions, this is quantified in the thesis.

Orientadores: Sandra Lucia Cruz, João Alexandre Ferreira da Rocha Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-07T19:03:10Z (GMT). No. of bitstreams: 1 Pavan_AndreMauricio_M.pdf: 4399374 bytes, checksum: d76e0e55472d41a43569b1e700a1a749 (MD5) Previous issue date: 2005 / Resumo: Vasos de pressão são equipamentos muito importantes numa indústria, sendo responsáveis por armazenar gases, líquidos e outros fluidos a altas pressões. Um pequeno vazamento nesses vasos pode ser muito perigoso, gerando poluição, explosão e perda financeira para a indústria. Por isso, é imprescindível uma rápida e eficaz detecção da ocorrência de qualquer vazamento. Este trabalho descreve o desenvolvimento e teste de uma técnica de detecção de vazamentos de gás em vasos de pressão, baseada na análise da pressão no interior do vaso e doruído sonoro gerado pelo vazamento. Na montagem experimental utilizou-se um vaso de pressão com capacidade 34,5 litros, operando com ar. A pressão no interior do vaso variou de 1 a 7 kgf/cm2. Vazamentos de diversas magnitudes foram simulados através de um orifício, instalado lateralmente no vaso, cujo diâmetro variou de 0,1 a 4,0 mm. Vazamentos foram detectados quando o vaso de pressão operava em batelada e também quando havia alimentação contínua de ar para o vaso. Para a detecção de vazamentos foi utilizado um microfone e um programa, em linguagem C, que faz a aquisição on-line, através de uma placa ADA, dos sinais provenientes de um transdutor de pressão conectado ao vaso e do microfone instalado no interior do vaso. O circuito elétrico que compatibiliza o sinal proveniente do microfone com aquele compreendido pela placa ADA foi desenvolvido no laboratório e apresenta duas etapas. Na primeira o sinal alternado é amplificado e na segunda o sinal passa por filtros passa banda de 1kHz, 5kHz e 9kHz gerando três sinais contínuos em diferentes faixas de freqüência. Os resultados obtidos mostraram que é possível detectar vazamentos através da detecção e análise dos ruídos sonoros gerados por vazamentos em vasos de pressão, mesmo quando a variação na pressão interna do vaso não é significativa. A resposta em freqüência do sinal do vazamento variou com a magnitude do vazamento e com as diferentes condições de pressão no interior do vaso. O sistema desenvolvido mostrou que pode ser uma ferramenta confiável para a supervisão de vasos de pressão / Abstract: Pressure vessels are very important equipment in the industry, being responsible for storing gases, liquids and other fluids at high pressures. A small leakage on them can be very dangerous, generating pollution, explosion and also financials losses to the industry. For those reasons, it is essential to have a fast and efficient leakage detection system. This work describes a leak detection technique of gas based on the analysis of the pressure in the vessel and the noise generated by the leak. An experimental apparatus was set up using a 34.5 liters pressure vessel, fitted with a system to simulate sudden leakage through small orifices. Compressed air was used in the leakage experiments and the pressure in the vessel varied between 1 and 7 kgf/cm2. Leaks of various magnitudes were simulated through orifices with sizes varying between 0.1 and 4 mm in diameter. Leaks were detected when the vessel operated with a batch of air and also when the vessel was continuously fed with air. The leak detection system used a microphone and a software, written in C language, for data acquisition through an ADA converter of the signals generated by a pressure transducer installed in the vessel and by the microphone which was placed inside the vessel. An electric circuit was developed to process the noise captured by microphone and had two different stages:- on the first, the signal was only amplified and, on the second stage, the signal was filtered through three band pass filters, centered in 1kHz, 5kHz and 9kHz each one, generating three continuous signals in different frequencies. The experimental results show that it is possible to detect leaks based on the detection and analysis of sound noises generated by leak occurrence in pressure vessels even when yht pressure in the vessel does not change significantly. The analysis of the signal amplitude for different frequencies shows that the leakage noise signal changes with the leakage size and pressure in the vessel. The developed system shows to be a very reliable tool for safety supervision of pressure vessels / Mestrado / Sistema de Processos Quimicos e Informatica / Mestre em Engenharia Química

Depleting oil reserves and fluctuating oil prices have necessitated to increase the efficiency of oil production process. This thesis is focused on developing low-cost sensors, which can increase oil production efficiency through real-time monitoring of oil wells and help in safe transport of oil products from the wells to the refineries. Produced fluid from an oil well is a complex mixture of oil, water and gases, which needs to be quantified for various strategic and operational decisions. For many years, test separators have been used to separate oil, water and gases into three separate streams and then to analyse them individually. However, test separators are being replaced by multiphase flow meters (MPFM) which can analyse the complex mixture of oil, water and gas without separating it. However, existing MPFMs are either intrusive or require fluid mixing before the sensing stage. In contrast to existing techniques, first part of this thesis presents a microwave sensor, which can measure water fraction in oil in a non-intrusive way without requiring it to be mixed. Gas fraction sensing can also be performed using the same microwave sensor, which is an on-going work. The sensor operates on dielectric measurement principles and comprises a microstrip T-resonator that has been optimized for a 3D pipe surface. Certain locations on an oil field have limited available space, for which we have also presented a compact version of the microwave water-fraction sensor in this thesis. In this version, metallic housing of the sensor has been used to function as a ground plane for the coaxially located spiral resonator. This housing also protects the sensor from environmental effects. In addition to the efficient production of oil, its safe transport is also a concern for the industry. It is physically impossible to inspect a network of thousands of kilometres of pipelines manually. The existing leak detectors suffer from low sensitivity, high false alarms and dependence on environmental effects. In the last part of this thesis, we present a flexible ringresonator based leak detector, which can be clamped at vulnerable locations along the pipeline for early leak detection.

This diploma thesis deals with the study of leakage problems in industry and the use of Agilent weight detectors for its detection. Based on the studies conducted, a hardware and software solution has been proposed for connecting the measuring elements to a helium detector at a simple configurable station. Additionally, a C# application was created. This application allows the leak detector to be controlled and data collected from the detector and its surroundings. The created application was tested in a real environment. The conclusion of this work is devoted to the possibilities of using the created application.

This master's thesis is focuses on problematic of monitoring data in consulting company TG Community Holding a.s. The design will consist of a create monitoring network for a traffic tracking primarily data volume size tracking. It would be a monitoring of atypical events on the network. This master's thesis will be used to implement the proposed solution in the holding.

High speed separators from Alfa Laval are widely in use for processing flammable and non-flammable liquids. The following work is focusing on the case of non-flammable liquid as the process liquid in case the working area around the equipment may contain quantities of explosive gases. As stated by Alfa Laval documentation, the major risk is leaking of the explosive atmosphere into the separator from the surrounding environment which may result in producing zone 1 or zone 2 of hazardous area classification. Zone 1: Area in which an explosive gas-air mixture is likely to occur for short periods in normal operation.1 Zone 2: Area in which an explosive gas-air mixture is not likely to occur, and if it occurs it will only exist for a very short time due to an abnormal condition.1 According to Alfa Laval design package, there is a need of continuous inert gas injection into the separator during the process in order to reduce the oxygen concentration and keep it in the safe level (inert gas purging) and this policy is aimed to meet the requirements of ATEX-directive 94/9/EC/2003. The objective of the current thesis is a wish to have a better understanding of the potential risks, evaluating them and try to find ways to ease the process. The outcome can be useful to make a basic instruction for further tests and simplifications as well. The separator GTN 50 is selected and hydrogen (1% concentration) is used to simulate the explosive atmosphere. The result of the tests indicates that the cooling down stage after normal operation is the only period in which hydrogen will leak into the separator, frame top part and it should be cleaned up before the next start up. A number of recommendations -Ventilation to the fresh air, Water discharges, Pressurized air injectionare also being tested and discussed. Ventilation to the fresh air and injection of pressurized air seem to be applicable A Standard Testing Flow chart is suggested and calculation on real case is considered. A number of additional ideas are also included in the last section.

UCP1 is a member of the mitochondrial transmembrane anion carrier protein superfamily and is required to mediate adaptive thermogenesis in brown adipose tissue (BAT). Once activated, UCP1 uncouples mitochondrial respiration from ATP synthesis, thereby wasting the protonmotive force formed across the mitochondrial inner membrane as heat. It is hypothesized that proton leaks through UCP1 could be a molecular target to combat certain forms of obesity. Although it is well established that UCP1 is regulated by allosteric mechanisms, alternative methods such as post-translational modification still remain to be explored. The aims of the present study were to confirm the phosphorylation of UCP1 and the physiological relevance of this modification. Using isoelectric focusing, we confirmed that UCP1 displayed acidic shifts consistent with phosphorylation in BAT mitochondria isolated from cold exposed versus warm acclimated mice. A mouse model that ectopically expressed UCP1 in skeletal muscle was used to explore the link between the mitochondrial redox status and UCP1 function. Our results show that the expression of UCP1 in skeletal muscle led to decreases in body and tissues weights. In contrast, glucose uptake into skeletal muscle, food intake and energy expenditure was increased with the expression of UCP1. Finally, proton leaks through UCP1 were determined to be increased in isolated mitochondria from transgenic versus wild-type mice. Taken together these results indicate a complex interplay between mitochondrial redox status, post-translational modification and UCP1 function. Elucidation of novel mechanisms regulating UCP1 offers alternatives strategies that can be explored in order to modulate BAT thermogenesis.