Although suitable CAD tools for thermal and electrical analyses in power electronic systems are available, traditional stand-alone simulation method seldom takes into consideration of the inter-dependency of semiconductor device power loss and junction temperature in an iterative process. However these dependencies are important, especially for applications where both cooling and power losses are driven by complex mechanisms. For a power supply system, a dynamic design process is necessary to address both electrical and thermal issues. It is because the steady state temperatures of the system are obtained from loss-and-temperature iteration. Once a system solid body model is built, iterations between power loss and junction temperature calculations are performed to obtain the steady state temperature distribution. Since reliability and failure rate of components are directly related to temperatures, an accurate model is critical to provide proper thermal management, which achieves maximum power density. All cooling-related data such as placement of components, airflow rate, heat sink size, and device types are subjected to design changes in order to meet ultimately the temperature requirements. The goal of this thesis is to demonstrate the benefits of integrated analysis and design tools applied in distributed power supply systems designs. First, it will significantly speed up the design process and eliminate the errors resulting from repeated manual data entry and information exchange. Second, the integrated electrical-thermal design tools encompass electrical, thermal, layout, and packaging design to obtain the optimal system design. / Master of Science

La combustion d’hydrocarbures représente encore aujourd’hui une part très majoritaire de la production d’énergie dans le monde, et en particulier dans l’industrie aéronautique. La plupart des brûleurs industriels sont alimentés par un carburant sous forme liquide, injecté directement dans la chambre de combustion, générant ainsi de fortes interactions entre le spray, l’écoulement turbulent et la flamme. Dans le but d’acquérir une meilleure compréhension de la structure complexe des flammes de spray, une étude numérique a été réalisée sur la configuration du brûleur diphasique KIAI, caractérisée de façon précise et complète expérimentalement. Une approche de type simulation des grandes échelles a été utilisée pour simuler la phase gazeuse tandis que la phase liquide était résolue selon un formalisme Lagrangien déterministe (LES-DPS). L’analyse détaillée de la structure de flamme de spray permet de mettre en exergue le rôle important de la combustion non prémélangée dans ce type de flamme. Cela a motivé dans une seconde étape le développement d’une nouvelle approche pour modéliser les flammes de diffusion turbulentes. Le modèle présenté s’appuie sur la réponse des flammes de diffusion laminaires au maillage, à l’étirement et au plissement. Le dégagement de chaleur global de la flamme a été analysé dans des configurations de complexité croissante, et la capacité du modèle à le décrire a été évaluée. / The combustion of hydrocarbons still represents a major part of the worldwide production of energy, especially in the aeronautical industry. Most industrial burners are fed with liquid fuel that is directly injected in the combustion chamber, generating a strong interaction between the spray, the turbulent flow and the flame. In order to provide a better understanding of turbulent spray flame complex structures, a numerical study has been performed on the two-phase flow burner KIAI which has been experimentally fully characterized. Numerical simulations consist of Large Eddy Simulation coupled to Discrete Particle Simulation for the dispersed phase (LES-DPS). A detailed analysis of the flame structure shows that non-premixed combustion plays an important role in this type of spray flame. This motivates, in a second step of the present work, the development of a new approach to model turbulent diffusion flames. The model is based on the response to the mesh, strain rate and wrinkling. The global flame heat release is analyzed through configurations of increasing complexity and the capacity of the model to describe it is evaluated.

The Dps (DNA-Binding Protein from Starved Cells) proteins are a class of stress-specific proteins with a major role in protecting DNA during the stationary phase of bacterial growth, through direct physical binding as well as ferroxidation. These proteins are characteristically dodecameric in nature. Mycobacterium smegmatis, which is the model organism used in this study has two Dps homologues- MsDps1 and MsDps2. MsDps1, that has previously been studied, is exceptional in having trimeric as well as dodecameric states in vitro. This work focuses on the functional domains of MsDps1, with respect to its oligomerisation and DNA binding property, the identification of a new Dps homologue MsDps2, the in vitro characterization of MsDps2 and elucidation of a possible function of the protein in the physiology of Mycobacterium smegmatis. The Thesis is organized as shown below: Chapter 1: The literature on the bacterial stationary phase physiology and the role of Dps has been reviewed in this chapter. It gives a brief introduction of the background of the present study including the stationary phase response of bacteria and the significance of studying bacteria under stress as apart from ideal conditions of growth, which has been the conventional approach until recently. The advantages of using Mycobacterium smegmatis as a model system, and its starvation-induced stationary phase are also discussed. An introduction to the Dps proteins as a family of proteins branched off from ferritins and nucleoid proteins is explained. A brief summary of the ferritin and nucleoid proteins is given. Similarities connecting Dps to both these protein families is described. The review of earlier work done in our laboratory on the mycobacterial MsDps1 protein is also presented. Chapter 2: involves the study of the solution properties of the protein including its ability to oligomerize in vitro. The MsDps1 protein exists in two forms, a trimer and a dodecamer. The trimer form is a unique feature of the M.smegmatis homologue. Dps proteins from other sources are characteristically dodecameric. Earlier studies have shown that the trimeric form of the protein can perform ferroxidation while the dodecamer can bind to DNA. The dodecamer can also perform ferroxidation and accumulate the oxidized iron in its negatively charged core. In this chapter, we show that the trimeric form is extremely stable, under various conditions of pHs. The protein, when over expressed in M.smegmatis, also shows the presence of the trimer, thus ruling out the effect of heterologous expression of the protein in E.coli. We further report here, the ideal conditions for dodecamerisation of the protein from trimer to dodecamer, which binds to DNA. The dodecamer once formed is also highly stable and does not revert back to the trimeric form. The structural stability of the dodecamer is expected, as it is the fully functional form of the protein that physically protects the DNA from stress. However, the high stability of the trimeric form and its precise conversion into a stable dodecamer is intriguing. It is interesting to study the functional significance in vivo of the oligomerisation process in MsDps1. In addition, we looked at the effect of over expression of the protein on the overall phenotype of Mycobacterium smegmatis, as evidenced by the colony morphology and find no visible alteration, when compared with the wild type. Chapter 3: deals with a more detailed structural analysis of the MsDps1 protein. The role of N and C termini of the protein in maintaining a stable oligomeric structure is studied by making an N-terminal deletion mutant of the protein which is found to be unable to form a dodecamer in solution. On the other hand, MsDps1 with a 16 amino acid C-terminal deletion, MsDpsΔC16, is able to form stable oligomeric structures, when the N-terminal is intact. A previous deletion reported from our laboratory with 26 amino acids deleted from the C-terminal tail, called MsDpsΔC26 showed inability to form stable oligomeric structures in vitro. Putting together all the above results, a model for the interaction of the N and C-terminal tails of the protein in maintaining a stable dodecamer is presented. A demarcation of the C-terminal tail of MsDps1 into regions determining the oligomeric stability and DNA binding was also inferred. The MsDpsΔC16 protein, does not bind to DNA although it forms a stable dodecamer. A further deletion of 10 amino acids, as seen in a previously made construct, MsDpsΔC26 disrupts both the DNA binding as well as the oligomeric stability of the protein. Chapter 4: describes the discovery of a new homolog of the Dps protein in M.smegmatis. It was named as MsDps2. Bio-informatics analysis carried out on the complete genome data of Mycobacterium smegmatis yielded a second homologue of Dps in addition to the one already present and characterized. Interestingly, out of the 300 homogues of Dps found in bacteria, only 195 are present as single copies in a bacterium. The rest exist as more than one homologue in the same bacterial genome. The basic characterization of this new Dps homologue and its confirmation as a Dps family member is the focus of this chapter. Chapter 5: deals with the possible functions of the new protein MsDps2. Electron micrography shows that the purified protein forms stable nucleoprotein-like complexes. Over expression of the MsDps2 proteins presents no difference in the colony morphology when compared with the wild-type. Western analysis shows that the MsDps2 protein is not expressed under normal conditions tested for growth. MsDps1, on the other hand shows expression under conditions of starvation and osmotic stress, as has been established previously in the laboratory. Hence, it can be inferred that the new protein MsDps2 does not perform the same function as MsDps1. However, the in vivo function of this protein remains an important question to be addressed. The appearance of in vitro nucleoid structures involving this protein under the electron microscope, suggests a possible role for this protein in the formation and stabilization of the mycobacterial nucleoid. Indeed extensive evidence for the same exists for the E.coli protein. Chapter 6: describes the results obtained from the sequence comparison of MsDps2 with other Dps proteins listed in the TIGR database. ClustalW sequence analysis, followed by the construction of a phylogenetic tree using the MEGA software, suggests that the mycobacterial Dps proteins fall into two separate groups, represented by the MsDps1 and MsDps2 homologues from Mycobacterium smegmatis. Chapter 7 Summary and Conclusions: A summary of the work presented in the thesis is given followed by the appendix sections. Appendix 1 includes list and maps of plasmids used. Appendix 2 details the theoretical DNA and protein sequences of the recombinant clones generated in the study and theoretical physical and chemical properties of the proteins studied, as calculated with the Expasy Protparam software. Appendix 3 includes raw data obtained from the bio-informatic analysis of MsDps2, obtained using ClustalW analysis.

This thesis is focused on proposing a design and providing the realisation of a CNC drill used for printed circuits. The first section is concerned with researching the background of CNC drills, which is followed by the proposed design and realisation of a custom model. Fundamental calculations and individual constructional aspects were carried out based on the chosen parameters. Furthermore, the operating electronic functions and the description of a G-code generating program is the main content of the second section. Finally, the last part of this thesis includes economic evaluation and the CNC drill’s assessment in practice.

Táto diplomová práca sa zaoberá návrhom a realizáciou výukového modelu pre študentov mechatroniky na vysokej škole. Úvod práce sa zaoberá krátkym uvedením do problematiky používania univerzálnej sériovej zbernice a jej implementáciou pre komunikáciu s mikrokontrolérom. Druhá časť je venovaná hardwaru zariadenia, medzi čo patrí voľba vhodného motoru, návrh vhodných elektronických komponentov, návrh dosiek plošných spojov a taktiež mechanickej konštrukcie celého zariadenia. Nasleduje softwarová časť, popisujúca praktickú realizáciu komunikácie, program v mikrokontroléry, a Toolbox, ktorý umožňuje užívateľovi jednoduchú interakciu s hardwarom a to jak z Matlabu. tak zo Simulinku. Kombinácia navrhnutých hardwarových a softwarových prvkov umožňuje jednoduchú cestu k zlepšeniu vedomostí študentov v oblastiach programovania, riadenia a modelovaní sústav. Pre tieto účely je práca rozšírená o pracovný list, ktorý dopĺňa navrhnuté zariadenie o sadu experimentálnych úloh, zameraných na vybrané mechatronické problémy.

The aim of this work was to create a communication interface of standard ARINC Aerospace Industry Bus 429. The work has slightly outlined existing solutions, from which it can draw inspiration. Further analysis was performed, analysis of ARINC 429 bus, analysis of Raspberry Pi platform on which the solution will be built, and analysis of selected bus controller HI-3593. After that concept was created, based on concept was created the scheme contains circuitry HI-3593. On the basis of the scheme was created DPS. Next was created software for DPS. In the end of this work was tested abilities to receive and send messages on the bus ARINC 429.

This project deals with the subject of laboratory preparation for low-frequency and audio electronics. It is used DSP audio processor with integrated ADCs and DACs converters ADAU1701 from Analog Devices. Also, Atmel microcontroller with a connected graphic LCD display and buttons is used for adjusting DSP. The work presents the complete instructions of the laboratory project with a model protocol.

No description available.

Os equipamentos elétricos instalados em linhas de transmissão e distribuição de energia são normalmente submetidos a condições anormais e intensos campos elétricos, que, eventualmente, levam, entre outros fenômenos, as descargas parciais (DPs). Estas descargas têm sido apontadas como uma das principais causas de falhas de equipamentos e envelhecimento precoce. Portanto, detectar DPs se tornou uma questão importante na busca de uma energia elétrica eficiente e confiável. No que se refere a detecção de DPs existem vários sensores que podem ser aplicados, a exemplos: óptico, magnético ou acústico, e cada um deles apresentando vantagens particulares e limitações. Uma das desvantagens de tais sensores é o custo elevado, o que restringe o monitoramento de DPs no âmbito da distribuição de energia mais especificamente em transformadores de potência. Embora, se o foco do monitoramento é apenas detectar a ocorrência de DPs, uma nova classe de sensores acústicos implementados com piezoeletretos pode ser uma alternativa econômica viável. Deste modo, nesta dissertação, foi investigado o comportamento acústico de tais transdutores expostos a diferentes condições de DPs, onde o sensor piezoelétrico foi utilizado na detecção de DPs produzidas por uma configuração de eletrodos ponta - ponta separados por diferentes gaps de ar (único ou múltiplo) e excitado por altas tensões alternadas. As amplitudes dos sinais registrados foram correlacionadas com a distância do gap e com a amplitude da tensão aplicada. A partir dos resultados obtidos foi possível observar que a intensidade do som das DPs, capturado com o transdutor piezoelétrico, está relacionada com o tamanho do gap e da amplitude da tensão, como relatado na literatura. / Electrical equipment installed in power transmission and distribution lines are usually subjected to abnormal conditions and intense electric fields, which eventually lead, among others phenomena, to partial discharges (PDs). These discharges have been pointed as one of the main causes of equipment failures and premature aging. Therefore, detect PDs became an important issue in the prospect of efficient and reliable electric energy. Concerning PD detection there are several sensors that can be employed e.g. optical, magnetic or acoustic, and each of them presenting particular advantages and limitations. One of the drawback of such sensors is their elevated cost, which restricts the PD monitoring within the distribution of energy more specifically in power transformers. Although, if the intention of monitoring is only to detect the PD occurrence a new class of acoustic sensors implemented with piezoelectrets may be a feasible economic alternative. Therefore, in this work was investigated the acoustic behavior of such transducers exposed to different PD conditions, for instance, the piezoelectret sensor was employed on the detection of PD produced by a single or multiple point-to-point electrode setup with different air gaps excited by high AC voltages. The recorded signals amplitudes were correlated with the gap distance and voltage amplitude applied. Based on the results obtained it was observed that the intensity of the DPs sound, captured with the piezoelectric transducer, is related to the size of the gap and voltage amplitude, as reported in the literature.

Os equipamentos elétricos instalados em linhas de transmissão e distribuição de energia são normalmente submetidos a condições anormais e intensos campos elétricos, que, eventualmente, levam, entre outros fenômenos, as descargas parciais (DPs). Estas descargas têm sido apontadas como uma das principais causas de falhas de equipamentos e envelhecimento precoce. Portanto, detectar DPs se tornou uma questão importante na busca de uma energia elétrica eficiente e confiável. No que se refere a detecção de DPs existem vários sensores que podem ser aplicados, a exemplos: óptico, magnético ou acústico, e cada um deles apresentando vantagens particulares e limitações. Uma das desvantagens de tais sensores é o custo elevado, o que restringe o monitoramento de DPs no âmbito da distribuição de energia mais especificamente em transformadores de potência. Embora, se o foco do monitoramento é apenas detectar a ocorrência de DPs, uma nova classe de sensores acústicos implementados com piezoeletretos pode ser uma alternativa econômica viável. Deste modo, nesta dissertação, foi investigado o comportamento acústico de tais transdutores expostos a diferentes condições de DPs, onde o sensor piezoelétrico foi utilizado na detecção de DPs produzidas por uma configuração de eletrodos ponta - ponta separados por diferentes gaps de ar (único ou múltiplo) e excitado por altas tensões alternadas. As amplitudes dos sinais registrados foram correlacionadas com a distância do gap e com a amplitude da tensão aplicada. A partir dos resultados obtidos foi possível observar que a intensidade do som das DPs, capturado com o transdutor piezoelétrico, está relacionada com o tamanho do gap e da amplitude da tensão, como relatado na literatura. / Electrical equipment installed in power transmission and distribution lines are usually subjected to abnormal conditions and intense electric fields, which eventually lead, among others phenomena, to partial discharges (PDs). These discharges have been pointed as one of the main causes of equipment failures and premature aging. Therefore, detect PDs became an important issue in the prospect of efficient and reliable electric energy. Concerning PD detection there are several sensors that can be employed e.g. optical, magnetic or acoustic, and each of them presenting particular advantages and limitations. One of the drawback of such sensors is their elevated cost, which restricts the PD monitoring within the distribution of energy more specifically in power transformers. Although, if the intention of monitoring is only to detect the PD occurrence a new class of acoustic sensors implemented with piezoelectrets may be a feasible economic alternative. Therefore, in this work was investigated the acoustic behavior of such transducers exposed to different PD conditions, for instance, the piezoelectret sensor was employed on the detection of PD produced by a single or multiple point-to-point electrode setup with different air gaps excited by high AC voltages. The recorded signals amplitudes were correlated with the gap distance and voltage amplitude applied. Based on the results obtained it was observed that the intensity of the DPs sound, captured with the piezoelectric transducer, is related to the size of the gap and voltage amplitude, as reported in the literature.