No description available.

The present Master thesis entitled "Engineering Design and Optimization of Injector Holder" deals with the design of clamping holder, whose function is to ensure the exact position of injector system Common Rail. The shape of the injector holder is designed in the modelling program, both with respect to the installation space of internal combustion engine and also the method of manufacture. The proposed geometry is then subjected to stress analysis in the program using FEM. The final design phase is to optimize the geometry of the injector holder using the same method with the aim to reduce the weight of the component.

This dissertation presents a series of studies relating to optimization of kinematics and consumables during chemical mechanical planarization processes. These are also evaluated with the purpose of minimizing environmental and cost of ownership impacts.In order to study diamond micro-wear and substrate wear during planarization processes, a series of static etch tests and wear tests were performed using different types of diamond discs and subjected to various treatments. Scanning Electron Microscopy (SEM) and Inductively Coupled Plasma Membrane Spectroscopy (ICPMS) were used to estimate the extent of diamond micro-wear and substrate wear.Next, the impact of various factors (type of slurry abrasive, pH, abrasive content and abrasive concentration) on pad wear rate during planarization process was studied. Another study in this dissertation focuses on the development of a novel technique of using coefficient of friction (COF) data to distinguish between good and bad diamond discs. This study made use of the innovative tool diamond disc dragging device (DDD-100) designed and developed for the purpose of this study.It is known that the performance of chemical mechanical planarization depends significantly on the polishing pad grooving type and the kinematics involved in the process. Variations in pad grooving type as well as pressure and sliding velocity can affect polishing performance. One study in this dissertation investigates the effect of pressure and sliding velocity on the polishing performance. The study is conducted on multiple pressure and sliding velocity variations to understand the characteristic of each condition. A subsequent study focuses on the impact of pad grooving type on polishing performance.The greatest contribution of this dissertation involves development of the novel slurry injector to optimize the utilization of slurry during planarization processes. Slurry is a critical component in chemical mechanical planarization processes and accounts for approximately 50 percent of the cost of ownership (CoO). The novel injector apart from reducing the consumption of slurry, also contributed in addressing problems associated with foaming, reduced the number of defects and achieved better within wafer non-uniformity (WIWNU).

Children with life threatening food allergies live with the constant threat of a fatal reaction, and caregivers must always be prepared to treat with an epinephrine auto-injector (EAI). This interpretive phenomenological study explored parents’ perceptions and lived experiences with prescribed EAI use for their child. The purposive sample included 10 parents of five children under 12 years of age, diagnosed with a food allergy and prescribed with an EAI who recently experienced anaphylaxis. Eight main themes emerged: perception of anaphylaxis, life challenges, isolation, anxiety, hesitation, guilt, influence of health care, and lessons learned. Parents described multiple life challenges and feelings of isolation, anxiety and hesitation during a reaction that lead to subsequent guilt. Handling reactions correctly provided parents with confidence to treat subsequent reactions. Witnessing the effects of an EAI and receiving positive feedback from health care providers further strengthened their confidence to quickly and competently intervene in future reactions. / February 2017

Efforts to improve diesel fuel sprays have led to a significant increase in fuel injection pressures and a reduction in nozzle-hole diameters. Under these conditions, the likelihood for the internal nozzle flow to cavitate is increased, which potentially affects spray breakup and atomisation, but also increases the risk of causing cavitation damage to the injector. This thesis describes the study of cavitating flow phenomena in various single and multi-hole optical nozzle geometries. It includes the design and development of a high-pressure optical fuel injector test facility with which the cavitating flows were observed. Experiments were undertaken using real-scale optical diesel injector nozzles at fuel injection pressures up to 2050 bar, observing for the first time the characteristics of the internal nozzle-flow under realistic fuel injection conditions. High-speed video and high resolution photography, using laser illumination sources, were used to capture the cavitating flow in the nozzle-holes and sac volume of the optical nozzles, which contained holes ranging in size from 110 micrometers to 300 micrometers. Geometric cavitation in the nozzle-holes and string cavitation formation in the nozzle-holes and sac volume were both observed using transient and steady-state injection conditions; injecting into gaseous and liquid back pressures up to 150 bar. Results obtained have shown that cavitation strings observed at realistic fuel injection pressures exhibit the same physical characteristics as those observed at lower pressures. The formation of string cavitation was observed in the 300 micrometers multi-hole nozzle geometries, exhibiting a mutual dependence on nozzle flow-rate and the geometry of the nozzle-holes. Pressure changes, caused by localised turbulent perturbations in the sac volume and transient fuel injection characteristics, independently affected the geometric and string cavitation formation in each of the holes. String cavitation formation of was shown to occur when free-stream vapour was entrained into the low pressure core of a sufficiently intense coherent vortex. Hole diameters less than or equal to 160 micrometers were found to suppress string cavitation formation, with this effect a result of the reduced nozzle flow rate and vortex intensity. Using different hole spacing geometries, it was demonstrated that the formation of cavitation strings in a particular geometry became independent of fuel injection and back pressure once a threshold pressure drop across the nozzle had been reached.

<div>In this experiment, swirl injectors were designed and tested to validate their use in spraying liquid </div><div>lead into a Barton pot combustion chamber to produce lead oxide at a smaller particle size than </div><div>the current stream injection. Testing was done with water and air to determine the best design for </div><div>atomization results, and then the injector was fabricated for liquid lead testing. Thermochemistry </div><div>calculations showed that due to lead oxidation being a surface reaction, the combustion process </div><div>was diffusion controlled. These conditions were used to determine residence time inside a Barton </div><div>pot combustion chamber for predicted droplet sizes. Results of the liquid lead testing showed that </div><div>final lead oxide particle size and residence time was reduced when using a swirl atomizer in place </div><div>of a steady feed stream. Further calculations were done to create a model for a standard combustion </div><div>chamber and injection system for lead oxide production.</div>

Neste trabalho, apresentamos uma nova versão do injetor comutador, baseada na geometria retangular, mantendo a configuração de três peças, sendo a central móvel e as laterais fixas. Nesta condição, os parafusos de ajuste não funcionam como guia, tal como ocorre nos injetores da primeira geração. Este design facilita o deslocamento da parte móvel, contribuindo para a redução do atrito, o que permite o emprego de um pequeno motor de corrente contínua (12 V; 0,4 A), o qual foi usado para fazer o deslocamento da barra central da posição de amostragem para a de injeção e vice-versa. O funcionamento do injetor foi controlado pelo computador, usando apenas 2 bits de controle. A interface de controle projetada para esse fim, inclui a condição de reversão da direção de rotação do motor e lógica anti-duplicidade, então se os dois bits forem ativados ao mesmo tempo, a rotação do motor é mantida no sentido horário. Para testar a viabilidade deste injetor, o mesmo foi empregado para desenvolver um procedimento para determinação de etanol em bebidas destiladas. O procedimento fotométrico foi baseado na reação de etanol com dicromato de potássio. A detecção fotométrica foi realizada empregando um fotômetro de LED com máximo de emissão em 590 nm. O módulo de análise constituído pelo injetor e um conjunto de válvulas solenoide foi projetado para implementar o processo de reamostragem, adição intermitente de reagentes e transporte da zona de amostra com fluxo de ar. Após a definição das variáveis de controle, o sistema apresentou bom desempenho analítico, aliando vantagens tais como, boa velocidade, simplicidade de operação, versatilidade, proporcionando também um menor consumo de amostra e reagentes. Com relação às características analíticas, o sistema proposto apresentou faixa de resposta linear (r = 0,9972) para concentração etanol entre 10 - 50 % (v/v), limite de detecção de 2,0 % (v/v) etanol, desvio padrão relativo de 2,0 % (n =10) para uma amostra de etanol com concentração 40 % (v/v), um consumo de dicromato de 0,012 g por determinação e uma frequência analítica de 34 determinações por hora. / We present a new version of the commutator injector, based on the rectangular geometry, maintaining the three parts configuration with the central mobile and fixed side. In this condition, the adjusting screws do not functi as a guide, as occurs in the injector of first generation. This design facilitates the displacement of the movable part and contributes in reducing the friction, thus allowing the use of a small direct current motor (12 V, 0.4 A), which was used to perform the displacement of the central bar from the sampling position to the injection and vice-versa. The injector operation was controlled by a computer, which was done using only two control bits. The control interface designed for this purpose includes the condition for reversing the direction of the motor rotation and anti-duplication logic, so that both bits were activated at the same time, the motor rotation was maintained at clockwise direction. To test the feasibility of the injector, it was used to develop a procedure for determination of ethanol in spirit beverage. The procedure was based on the photometric reaction of ethanol with potassium dichromate. The photometric detection was performed using a LED based photometer with maximum of emission at 590 nm. The analytical module comprising the injector and a set of solenoid valves, was designed to implement the zone sampling process and Intermittent addition of reagents and sample zone displacement using an air stream. After definition of control variables, the system shown good analytical performance, combining advantages such as speed, simplicity of operation, versatility and also providing lower consumption of sample and reagents. With respect to analytical characteristics, the proposed system presented linear response range (r = 0.9972) between ethanol concentration to 10 - 50% (v/v), a detection limit of 2.0% (v/v) ethanol, relative standard deviation of 2.0% (n = 10) for a sample with an ethanol concentration of 40% (w/v), a dichromate consumption of 0.012 g by determination and a sampling rate of 34 determination per hour.

Um injetor de pastilhas (pellets) de impurezas foi projetado, construído e instalado junto ao tokamak TCABR do Instituto de Física da Universidade de São Paulo - USP. O injetor é basicamente constituído por uma câmara com gás a alta pressão cuja vazão é controlada por uma bobina de acionamento rápido. Uma fonte de alta tensão (7kV) e alta corrente (6kA) foi construída para alimentar a bobina. Ao ser disparada, o gás propulsor (N2 ou He) acelera a pastilha para o interior do vaso do tokamak, sem que gás penetre no mesmo. Pastilhas de grafite cilíndricas com diâmetro de 0,4mm a 0,9mm, e comprimento de 0,5mm a 1mm, foram utilizadas para investigar a possibilidade de se mitigar os e*feitos de uma disrupção maior O processo de ablação da pastilha no TCABR foi investigado através de simulações que consideraram, de uma maneira simplificada, o resfriamento sofrido pelo plasma devido à propagação da pastilha no seu interior. O modelo, ao ser aplicado aos dados experimentais do tokamak T-10, por exemplo, apresentou resultados bastante encorajadores. Na maioria dos casos em que houve a injeção das pastilhas no TCABR, o plasma terminou devido ao surgimento de uma disrupção maior. Analisando a taxa de queda da corrente de plasma em dois instantes próximos ao fim da descarga, tanto para pulsos que sofreram uma disrupção natural quanto aos que sofreram um disrupção induzida (devido à injeção de pastilhas de grafite), constatou-se que a corrente de plasma decresce mais lentamente nos casos em que houve o disparo do injetor. Isto significa uma menor sobrecarga nos sistemas eletro-mecânicos do tokamak, em resultado à ocorrência da disrupção. A análise da atividade MHD foi realizada no entorno da disrupção causada pela injeção de pastilha. Observou-se, em conseqüência, uma redução da velocidade de rotação das ilhas magnéticas após o início da interação da pastilha com o plasma. Também constatou-se, em todos os disparos analisados, um aumento significativo da atividade MHD. Um outro resultado interessante foi a constatação de que a emissão de raios-X de altas energias decresce significativamente no final das descargas nas quais ocorre a injeção de pastilhas. / An impurity pellet injector has been projected, built and installed in the TCABR tokamak, at the Physics Institute of Physics of the University of São Paulo - USP. Basically, the injector is composed of a high pressure gas chamber, in which the gas flow (N2 or He) is controlled by a fast switch valve. An high voltage (7kA) and high electric current (6kA) power supply has been built to provide energy for the valve. When fired, the propellant gas move the pellet into the interior of the tokamak vessel. During this process, the gas is properly collected before reaching the tokamak vacuum chamber. For this work, cylindrical carbon pellets with 0,4mm to 0,9mm in diameter and 0,5mm to 1mm in length were chosen as to investigate how the hazardous effects of a major disruption could be mitigated. The pellet ablation process in TCABR was studied trough running simulations that take into account, in a simplified way, the cooling of the plasma by the propagating pellet. The model, when applied to the T-10 tokamak experimental data, for example, exhibited very encouraging results. For the TCABR tokamak, in most of the cases in which pellets were injected, the plasma was terminated because of the advent of a major disruption. By analyzing the plasma current decay rate in two time intervals - within the end of plasma discharges, with and without the injection of pellets, it was observed that the plasma current decays significantly slower when pellets are injected. Consequently the load on the tokamak\'s electromechanical systems is reduced. Fourier analysis has been carried out to investigate the MHD activity near the disruption time, caused by the pellet injection. It could be noticed a reduction on the magnetic island\'s velocity rotation, after the pellet-plasma interaction initiates. Also, for all discharges analyzed, the MHD activities increased in amplitude after the pellet-plasma interaction. Another interesting result refers to the fact that the hard X-ray emission was observed to decrease significantly within the end of discharges in which pellets were injected

Decades of research on compression ignition engines have led to a highly efficient combustion cycle in contemporary diesel engines. Nonetheless, the combustion process is being studied perpetually to meet both current and future emission regulations. One of the most influential parameters that impacts the combustion quality, is the fuel spray evolution during injection, and subsequent fuel-air mixture formation inside the engine cylinder. The spray evolution has been investigated to a high level of detail, and the highly complex processes of mixture formation and combustion are well-documented for diesel engines. Most of these investigations are limited to studying either research-grade injectors, or brand new production injectors. Injectors in real-world diesel engines, i.e. normal passenger cars and trucks that are used on a daily basis, are however subject to deposit formation at the tip of the injector nozzle. These deposits have the potential of altering the internal nozzle flow and fuel spray pattern, which in turn degrades combustion quality and increases engine emissions. In the work presented in this thesis the spray evolution of production injectors has been studied over a wide range of injector conditions. Common rail light-duty injectors with a usage history of up to 90 000 miles were acquired from the UK commuter car parc, and several brand new injectors were studied for comparison purposes. It is shown that the spray pattern of the injected fuel changes over the lifetime of the injector. For used injectors a reduced penetration rate was observed in the transient regime of fuel injection, during needle lift. The reduced penetration rate was often accompanied by anomalous radial expansions. Although the magnitude of the effects varied from injector to injector, the highest mileage injectors tended to produce the strongest spray deviations. For several high-mileage injectors the end of injection appeared retarded with respect to new injectors. Expulsions of liquid ligaments and droplets after the end of injection were observed from all injectors, irrespective of the mileage of the injector.

O recente avanço tecnológico dos processadores embarcados aumentou a complexidade dos compiladores e o uso de recursos heterogêneos, como Arranjo de Portas Programáveis em Campo (Field Programmable Gate Array - FPGA) e Unidade de Processamento Gráfico (Graphics Processing Unit - GPU), integrado aos processadores. Além disso, aumentou-se o uso de componentes de prateleira (Commercial off-the-shelf - COTS) em aplicações críticas, ao invés de chips tolerantes a radiação, pois os COTS podem ser mais baratos, flexíveis, terem uma rápida colocação no mercado e um menor consumo de energia. No entanto, mesmo com essas vantagens, os COTS são suscetíveis a falha sendo necessário garantir uma alta confiabilidade nos sistemas utilizados. Assim como, no caso de aplicações em tempo real, também se precisa respeitar os requisitos determinísticos. Como caso de estudo, este trabalho utiliza a Zynq que é um dispositivo COTS do tipo Sistema em Chip Totalmente Programável (All Programmable System on Chip - APSoC) no qual possui um processador ARM Cortex-A9 embarcado. Nesta pesquisa, investigou-se o impacto das falhas que afetam o arquivo de registradores na confiabilidade dos processadores embarcados. Para tanto, experimentos de injeção de falhas e de radiação de íons pesados foram realizados. Além do mais, avaliou-se como os diferentes níveis de otimização do compilador modificam o uso e a probabilidade de falha do arquivo de registradores do processador. Selecionou-se seis benchmarks representativos, cada um compilado com três níveis diferentes de otimização. Realizamos campanhas exaustivas de injeção de falhas para medir o Fator de Vulnerabilidade Arquitetural (Architectural Vulnerability Factor - AVF) de cada código e configuração, identificando os registradores que são mais propensos a gerar uma corrupção de dados silenciosos (Silent Data Corruption - SDC) ou uma interrupção funcional de evento único (Single Event Functional Interruption - SEFI). Também foram correlacionadas as variações de confiabilidade observadas com a utilização do arquivo de registradores. Finalmente, irradiamos com íons pesados dois dos benchmarks selecionados compilados com dois níveis de otimização. Os resultados mostram que mesmo com o melhor desempenho, o menor uso do arquivo de registradores ou o menor AVF não é garantido que as aplicações irão alcançar a maior Carga de Trabalho Média Entre Falhas (Mean Workload Between Failure - MWBF). Por exemplo, os resultados mostram que o melhor desempenho da aplicação Multiplicação de Matrizes (Matrix Multiplication - MxM) é alcançado no nível de otimização mais alta. No entanto, nos resultados dos experimentos de injeção de falhas, a maior confiabilidade é alcançada no menor nível de otimização que possuem os menores AVFs e o menor uso do arquivo de registradores. Os resultados também mostram que o impacto das otimizações está fortemente relacionado com o algoritmo executado e como o compilador faz esta otimização. / The recent advances in the embedded processors increase the compilers complexity, and the usage of heterogeneous resources such as Field Programmable Gate Array (FPGA) and Graphics Processing Unit (GPU) integrated with the processors. Additionally, the increase in the usage of Commercial off-the-shelf (COTS) instead of radiation hardened chips in safety critical applications occurs because the COTS can be more flexible, inexpensive, have a fast time-to market and a lower power consumption. However, even with these advantages, it is still necessary to guarantee a high reliability in a system that uses a COTS for safety critical applications because they are susceptible to failures. Additionally, in the case of real time applications, the time requirements also need to be respected. As a case of study, this work uses the Zynq which is a COTS device classified as an All Programmable System-on-Chip (APSOC) and has an ARM Cortex-A9 as the embedded processor. In this research, the impact of faults that affect the register file in the embedded processors reliability was investigated. For that, fault-injection and heavy-ion radiation experiments were performed. Moreover, an evaluation of how the different levels of compiler optimization modify the usage and the failure probability of a processor register file. A set of six representative benchmarks, each one compiled with three different levels of compiler optimization. Exhaustive fault injection campaigns were performed to measure the registers Architectural Vulnerability Factor (AVF) of each code and configuration, identifying the registers that are more likely to generate Silent Data Corruption (SDC) or Single Event Functional Interruption (SEFI). Moreover, the observed reliability variations with register file utilization were correlated. Finally, two of the selected benchmarks, each one compiled with two different levels of optimization were irradiated in the heavy ions experiments. The results show that the best performance, the minor register file usage, or the lowest AVF does not always bring the highest Mean Workload Between Failures (MWBF). As an example, in the Matrix Multiplication (MxM) application, the best performance is achieved in the highest compiler optimization. However, in the fault injection, the higher reliability is obtained in the lower compiler optimization which has, the lower AVFs and the lower register file usage. Results also show that the impact of optimizations is strongly related to the executed algorithm and how the compiler optimizes them.