[pt] Esta dissertação de Mestrado teve por objetivo a concepção, desenvolvimento e validação de um dispositivo opto-eletrônico, que opera na faixa do infravermelho, para detecção e medição da velocidade de esferas em meios turvos. A motivação para desenvolvimento deste tema resultou da necessidade de controlar a circulação de esferas para instrumentar um sistema alternativo de limpeza de trocadores de calor de hidrogeradores, que faz uso de artefatos abrasivos de geometria esférica. O método utilizado fundamenta-se no processamento do sinal eletrônico gerado por um circuito que produz pulsos proporcionais ao tempo de passagem da esfera no interior do contador, a cada interrupção do feixe luminoso. O tratamento do sinal, gerado por pares de sensores opto-eletrônicos perpendiculares entre si e montados transversalmente ao fluxo de água de resfriamento que transporta as esferas, é realizado por um controlador lógico programável, que atribui inteligência ao sistema. Dentre os resultados obtidos, constatou-se que o dispositivo consegue detectar esferas circulantes quando transportadas por fluxos de água com diferentes graus de turbidez (ensaios em laboratório) ou quando em operação no ambiente da usina hidrelétrica, cuja opacidade da água de resfriamento é dada pela incrustação removida durante o processo de limpeza. Como conclusão, pode-se afirmar que o dispositivo opto-eletrônico proposto atende às necessidades do projeto de construção de um sistema alternativo de limpeza por esferas abrasivas, conseguindo descartar falsos positivos na contagem das esferas, a exemplo de bolhas de ar ou partículas de incrustação cujas dimensões críticas diferem daquelas das esferas abrasivas. / [en] This dissertation aimed at the design, development and validation of an optoelectronic device, operating in the infrared range, for counting and measuring the velocity of spheres in turbid media. The motivation to develop this theme resulted from the need to control the spheres circulation to implement an alternative system for cleaning heat exchangers used to cool hydrogenerators, which make use of spherical abrasive artefacts. The methodology used is based on the processing of the electronic signal generated by a circuit that produces pulses proportional to the time of passage of the sphere inside the meter, at each interruption of the light beam. The processing of the signal, which is generated by pairs of mutually perpendicular optoelectronic sensors and mounted transversely to the flow of cooling water carrying the spheres, is performed by a programmable logic controller, which provides intelligence to the system. Among the obtained results, it was verified that the device can detect circulating spheres both when transported by water flows with different degrees of turbidity (laboratory tests) and when in operation in the environment of the hydroelectric plant, whose opacity of the cooling water is given by the fouling removed during the cleaning process. As a conclusion, it can be stated that the proposed optoelectronic device meets the needs of the construction of the alternative system of cleaning by abrasive spheres and can eliminate false positives in the counting of the spheres, such as air bubbles or incrustation particles whose critical dimensions differ from those of the abrasive spheres.

[pt] Problemas com incrustações em equipamentos são frequentes em equipamentos de resfriamento de mancais de turbinas hidráulicas e hidrogeradores, drasticamente comprometendo a sua eficiência de operação. Pesquisas aplicadas buscam a eficiência térmica dos trocadores de calor por meio da mitigação do fouling formado nesses equipamentos. Esta dissertação de mestrado tem por objetivo avaliar a eficácia de uma alternativa tecnológica de limpeza dos tubos do trocador de calor que faz uso de esferas abrasivas para mitigar indesejáveis incrustações em trocadores de calor utilizados no arrefecimento de hidrogeradores. A motivação da pesquisa deu-se no contexto do projeto de PeD Light-Aneel Ref.: 07/2011, Proposição de solução inovadora para o sistema de resfriamento dos hidrogeradores da Usina Fontes Nova, desenvolvido pelo Programa de Pós-graduação em Metrologia da PUC-Rio. Superando o desafio de oferecer um método de limpeza que evita a raspagem mecânica e o uso de produtos químicos, o trabalho construiu um equipamento e validou uma alternativa tecnológica de limpeza, que opera on-line, portanto sem a necessidade de parada técnica da usina para realizar a manutenção. A metodologia utilizada fundamenta-se na análise do desempenho hidrodinâmico e térmico do trocador de calor quando assistido pelo sistema proposto. Dentre os resultados, destacam-se (i) o caráter prático da alternativa de limpeza proposta, que realiza a limpeza sem a necessidade de interromper a geração e (ii) o estudo da velocidade ótima das esferas para assegurar eficácia do processo de desobstrução dos trocadores. Os resultados favoráveis dos testes de desempenho realizados em laboratório e no campo consubstanciam a conclusão do trabalho, permitindo validar a técnica e o protótipo de equipamento construído para ser utilizado nas condições reais de operação da usina. / [en] Formation and deposit of fouling is a common problem encountered in heat exchangers, bearings of hydraulic and hydro turbines, drastically reducing their operation efficiency. Applied research continuously seeks for gains in thermal efficiency by encouraging fouling mitigation in the internal passages of heat exchangers. This dissertation aims to evaluate the effectiveness of a technological alternative for cleaning heat exchanger tubes by the use of abrasive spheres to mitigate undesirable fouling in heat exchangers used in hydro generators cooling. The motivation of the research took place in the context of the ReD project Light- Aneel 07/2011, entitled Innovative solution for fouling mitigation of heat exchangers used in the cooling system of the Fontes Nova Power Plant, developed by the postgraduate Metrology Programme of Catholic University of Rio de Janeiro, financed under a Brazilian government regulated R&D Programme. Overcoming the challenge of providing a cleaning method that prevents the mechanical scraping and the use of chemicals, a prototype of an equipment was built and validated as a technological alternative cleaning tool, which operates online, therefore without the need to shutdown the power plant to perform the heat exchanger maintenance. The methodology is based on the analysis of hydrodynamic and thermal performance of the heat exchanger when assisted by the envisioned system. Among the results achieved, the work highlights (i) the practical character of the cleaning alternative proposed, which performs the cleaning without the need to interrupt the electrical energy generation and (ii) the study of the optimum speed that must be imposed to the abrasive spheres to ensure effectiveness of the unclogging process of the exchangers. The favourable results emerged from the performance tests carried out in the laboratory and in the field environments substantiate the conclusion of the work, validating the technical method and the prototype of the equipment to operate in the real conditions of the power plant.

This thesis deals with the design and implementation of a device for measuring pull strength by surface mounted devices (SMD). It analyzes the theory of pull strength testing of solder joints with emphasis on standard IEC 62137-1-3 and describes the selection of components utilized to create mechanical construction and electrical parts. These electronic parts made or innovated in this work were control system based on microcontroler Atmega164P, power circuit for stepper motor and communication of measure equipment TEST 321 with PC. The whole design is complemented by simulation of mechanical stress to the critical components using ANSYS. The conclusion summarizes the most important parameters of this equipment.

No description available.

No description available.

This thesis is concerned with the problem of predicting the remaining part of the trajectory of a golf ball as it travels through the air where only the three-dimensional position of the ball is captured. The approach taken to solve this problem relied on recurrent neural networks in the form of the long short-term memory networks (LSTM). The motivation behind this choice was that this type of networks had led to state-of-the-art performance for similar problems such as predicting the trajectory of pedestrians. The results show that using LSTMs led to an average reduction of 36.6 % of the error in the predicted impact position of the ball, compared to previous methods based on numerical simulations of a physical model, when the model was evaluated on the same driving range that it was trained on. Evaluating the model on a different driving range than it was trained on leads to improvements in general, but not for all driving ranges, in particular when the ball was captured at a different frequency compared to the data that the model was trained on. This problem was solved to some extent by retraining the model with small amounts of data on the new driving range. / Detta examensarbete har studerat problemet att förutspå den fullständiga bollbanan för en golfboll när den flyger i luften där endast den tredimensionella positionen av bollen observerades. Den typ av metod som användes för att lösa problemet använde sig av recurrent neural networks, i form av long short-term memory nätverk (LSTM). Motivationen bakom detta var att denna typ av nätverk hade lett till goda resultatet för liknande problem. Resultatet visar att använda sig av LSTM nätverk leder i genomsnitt till en 36.6 % förminskning av felet i den förutspådda nedslagsplatsen för bollen jämfört mot tidigare metoder som använder sig av numeriska simuleringar av en fysikalisk modell, om modellen användes på samma golfbana som den tränades på. Att använda en modell som var tränad på en annan golfbana leder till förbättringar i allmänhet, men inte om modellen användes på en golfbana där bollen fångades in med en annan frekvens. Detta problem löstes till en viss mån genom att träna om modellen med lite data från den nya golfbanan.

[pt] A dissertação de mestrado tem por objetivo estudar a indesejável formação do fouling no sistema de arrefecimento dos hidrogeradores da usina hidrelétrica Fontes Nova com vistas a propor técnicas alternativas para a sua mitigação. Mais especificamente, avaliar o desempenho de uma técnica antifouling que expõe o escoamento à ação de um campo elétrico externo. A pesquisa foi motivada (i) pela perspectiva de contribuir para o entendimento do complexo fenômeno de formação e mitigação do fouling e (ii) pelo desafio de propor um método on-line, não invasivo, de simples operação, em contraposição aos métodos de limpeza mecânica e química normalmente ofensores do meio ambiente e que requerem a interrupção da geração. Desenvolvido no contexto do projeto de PeD Light/Aneel Ref. OKE 06-07 intitulado Tecnologia de tratamento de água de refrigeração da usina Fontes Nova, a pesquisa, de natureza experimental e quantitativa, desenvolveu-se com base numa metodologia que avalia o desempenho hidrodinâmico e térmico do trocador de calor quando submetido à ação do dispositivo antifouling estudado. Os resultados do trabalho permitiram concluir que a incrustação predominante é de natureza Bio (biofouling) e que embora o dispositivo não invasivo iniba a formação dos indesejáveis micro-organismos que obstruem o trocador e afetam a sua eficácia de operação ele não elimina o problema. A partir dessa constatação, uma técnica alternativa de limpeza on-line que faz uso de esferas abrasivas foi concebida e projetada para promover a limpeza do trocador de calor em operação. / [en] The objective of the master thesis is to study the undesirable formation of fouling in the cooling system of hydroeletric generators of Fontes Nova Power Plant with the view to propose an alternatives techniques for its mitigation. more specifically, to assess the performance of an antifouling device that exposes the flow to the action of an external electric field. The research was motivated by the perspective of contributing to the understanding of the complex phenomenon associated with the formation and mitigation of fouling and by the challenge of proposin an alternate on-line, non-invasive method, of simple operation, contrasting to conventional of mechanical and chemical cleaning methods that normally offender the environment and requires interruption of the generation. Developed in the context of the project R and D light/aneel Ref. OKE 06-07 entitled Technology for treatment of refrigeration water of the Fontes Nova Power Plant, the research, of quantitative and experimental nature, was developed based on a methodology that assess the of hydrodynamic and thermal performance of the heat exchanger when submitted to the action of the antifouling device studied. The results of the work support the conclusion that the fouling is of a biological nature (biofouling) and that although the non-invasive device inhibits the formation of the unwanted microorganisms that block the exchanger and affect its effectiveness of operation it does not eliminate the problem. An alternative on-line cleaning technique that makes use of abrasive spheres was designed and engineered to clean the heat exchanger in operation.

La Tesis Doctoral está dedicada al estudio de ciertas propiedades de los radios sucesivos de los cuerpos convexos (funcionales definidos a partir de circunradios e inradios de proyecciones o secciones del cuerpo). Comenzamos estableciendo las nociones básicas necesarias para el desarrollo de los contenidos. A continuación calculamos los radios sucesivos de familias particulares de conjuntos (p-bolas, anchura constante, cuerpos tangenciales), y estudiamos la conexión existente entre estos funcionales y los números de Gelfand y Kolmogorov. En el tercer capítulo consideramos el problema de Pukhov-Perel'man sobre la mejor cota superior para un cierto cociente de radios, determinando desigualdades para problemas de este tipo que van a permitir mejorar los resultados existentes en ciertos casos. Finalmente, estudiamos cómo se relacionan los radios sucesivos de la suma de Minkowski (Firey) de dos cuerpos convexos con los correspondientes funcionales de los conjuntos, obteniendo los resultados óptimos en todos los casos. / The Doctoral Thesis is focused in the study of some properties of the successive radii of convex bodies (functionals defined by means of circumradii and inradii of projections or sections of the set). We start establishing the basic notions that will be needed further on. Next, we compute the successive radii of particular families of sets (p-balls, constant width sets and tangential bodies), and study the connection between these functionals and the Gelfand and Kolmogorov numbers. In the third chapter we consider the Pukhov-Perel'man problem on the best upper bound for a particular ratio of radii, determining inequalities for some problems of this type which will allow to improve the known results in particular cases. Finally we study how the successive radii of the (Firey)-Minkowski addition of two convex bodies are related with the corresponding functionals of the sets, obtaining the optimal results in all cases.

Ett företag som tillverkar hydrauliska snabbkopplingar har genom regelbundna kvalitetsprover upptäckt att vissa låskulor till snabbkopplingarnas låsmekanism plötsligt fått en bristande kvalité och spricker vid belastning. Låskulorna är gjorda av rostfritt stål och har en viktig funktion i låsmekanismen. Om de spricker vid användning kan det leda till konsekvenser med materiella skador eller personskador. Företaget vill förekomma eventuella kvalitetsproblem och måste därför säkerställa att låskulorna har rätt hållfasthet. Låskulorna köps in från en underleverantör och företaget vill därför utveckla en provmetod som provar låskulornas materialegenskaper när de levereras till fabriken. Arbetet i denna rapport syftar till att hjälpa företaget utveckla en sådan provmetod. Ett första steg är att undersöka orsaken till att låskulorna spricker. Materialanalyser utförs av ett materiallaboratorium för att fastställa vilka faktorer i materialet som orsakar brott i låskulorna. Analyserna visar att låskulorna sannolikt spricker på grund av en ökad sprödhet i materialet. Sprödheten beror på att martensiten i materialet är dåligt anlöpt samt en stor mängd karbider. Med orsaken till sprickorna fastställd undersöks befintliga metoder för materialprovning. En provmetod måste prova materialet i färdigtillverkade låskulor eftersom låskulornas tillverkningsprocess påverkar materialegenskaperna. Många av de standardiserade provmetoderna är dock svåra att tillämpa på låskulorna med anledning av låskulornas geometri och små dimensioner. En form av slagprov och pressprov utförs på låskulorna. Ett av syftena med proven är att undersöka om de är lämpliga att använda som provmetod. Genom proven framträder olika materialegenskaper för olika låskulor. Resultaten är dock inte jämförbara låskulorna emellan och proven anses inte vara lämpliga som provmetod. Även ett utmattningsprov utförs på låskulorna genom en upprepande belastning i en snabbkoppling. Detta prov är inte heller lämpligt att använda som provmetod då provet är mycket tidskrävande samt att det finns vissa osäkerheter kring provresultatet. I detta arbete undersöks även två nyligen framtagna provmetoder för kulor till kullager och möjligheten att tillämpa dessa provmetoder på låskulorna. I undersökningen jämförs de båda provmetoderna med avseende på utförande samt framtagning av provkropp. Även en spänningsanalys av en låskula belastad i en snabbkoppling utförs för att ta reda på i vilket område av låskulan de maximala spänningarna uppstår. Undersökningen ger att enbart en provmetod är intressant för fortsatt arbete.   Den provmetod som föreslås i detta arbete kallas "the notched ball test" (NBT). Provmetoden innebär att en djup och smal skåra bearbetas i en låskula som sedan belastas med en tryckande kraft vinkelrätt mot skåran tills brott uppstår. Den maximala spänningen som verkar vid brottet beräknas med en enkel ekvation och används som mått för låskulans hållfasthet. Provmetoden är lämplig då den går att utföra med befintlig utrustning på företaget, den provar materialet i färdigtillverkade låskulor samt i samma område som de maximala spänningarna i en låskula belastad i en snabbkoppling uppstår. NBT nyttjar även dragspänningar vilket är fördelaktigt när sprödhet ska upptäckas i ett material. För att fastställa hur olika materialegenskaper samt geometrier för provkroppen påverkar provresultaten utförs en djupare analys av provmetoden. Analysen ger även vilka geometrier som bör användas vid utförandet av NBT samt värdet för den konstant som används vid beräkning av brottspänningen. Praktiska prov av NBT utförs inte i detta arbete men rapporten innefattar slutsatser om provmetoden och rekommendationer till företaget hur ett fortsatt arbete med NBT kan utföras. / A company that manufactures hydraulic quick-couplings has discovered through regular quality checks that the quality of some of the locking balls for the locking mechanism in the quick couplings suddenly has become insufficient and the locking balls rupture under load. The locking balls are made of stainless steel and if they rupture during usage the consequences can be material damage or even personal injury. The company wants to prevent any quality problems and must therefore ensure that the strength of the locking balls is sufficient. The locking balls are purchased from a subcontractor and the company would therefore like to develop a method for strength testing locking balls delivered to the factory. This thesis aims to help the company in developing such a method.  A first step is to investigate the cause of the locking balls rupture. Material analyses are executed by a material laboratory in order to determine what features in the material that causes the ruptures. The analyses shows that rupture is probably caused by an increased brittleness in the material and the brittleness is a consequence of less tempered martensite and a high amount of carbides. With the cause of rupture determined, existing methods for testing material properties is studied. It is important that strength testing is carried out with test specimens prepared from the actual locking balls. Otherwise the influence of the locking balls manufacturing process on the material properties is not taking into account. Many of the standardized methods for testing material properties, however, are hard to apply to the locking balls due to the geometry and small dimensions of the locking balls. A kind of impact test and compression test is performed. One of the purposes with the tests is to investigate if they are adequate for strength testing the locking balls. The results of the tests, however, are not suitable for comparison. Also, a fatigue test of the locking balls is performed by a repetitive loading of a quick coupling. The fatigue test is, however, time consuming and there are uncertainties in the test results. None of these tests is considered suitable as a strength testing method. In this thesis, two recently developed methods for strength testing ceramic balls and the possibility to apply these methods on the locking balls is studied. The study includes an analysis of the stress distribution in a locking ball under load to determine in which region the highest stresses occur. The study provides that only one of the methods is suitable for the locking balls due to differences in preparing the test specimen and which region of the locking ball that is tested in each method. The strength testing method that is proposed in this thesis is called the notched ball test (NBT). In NBT a long and narrow notch is cut in a locking ball which is then loaded in compression perpendicular to the notch until rupture occurs. The maximum stress acting at the rupture is calculated and used to determine the strength of the locking ball. NBT is suitable because it can be performed with existing equipment at the company, the test specimen is prepared from actual locking balls and the test uses tensile stresses which is an advantage when brittleness is to be detected in a material. An analysis of NBT is performed to determine how material properties and different notch geometries is affecting the test results. The analysis also gives some recommendations for notch geometries that should be used when performing NBT as well as a constant that is used when calculating the maximum stress. Practical experiments of NBT are not carried out in this thesis. Instead, conclusions regarding NBT and recommendations for the company on how they should proceed with NBT are given.

Title: Guide for selection of tennis equipment for players and coaches Objectives: The main purpose of this thesis is to create a detailed guide for selecting tennis equipment for players and coaches, which will help players choose right racquet, strings, balls, shoes and bags. At the same time, it will inform the reader about equipment for tennis coaches. In addition a questionnare will be elaborated to detect the equipment preferences of players at performance level. Methods: Content analysis of documents was used in this thesis and was completed by a questionnare. Results: Result of this thesis is a guide for selecting tennis equipment for players and a coach, which helps people choose the right racquet and strings. One will also gain better knowledge of tennis ball characteristics in connection with different surfaces and varying game styles. Also results from the questionnare will be elaborated to illustrate the preferences of players at performance level. Keywords: Tennis, guide, tennis racquets, tennis strings, tennis shoes, tennis bags, tennis balls, history of tennis, tennis accessories, equipment, coach.