No description available.

No description available.

This thesis deals with the low cycle fatigue nickel-based superalloy IN713LC with applied TBC barrier at high temperature. The theoretical part is divided into four sections. The first one focuses on description of fatigue damage. The second one provides the basic characteristics of nickel-based superalloys. The third section describes the use of the surface layers - diffusion layers and thermal barriers and the fourth section deals with the influence of these layers on fatigue properties. Experimental part is focused on the evaluation of low cycle fatigue tests and on the explanation of the mechanisms of initiation and propagation of fatigue cracks. For the experimental part, fatigue samples were prepared by vacuum precision investment casting. TBC barrier was applied by atmospheric plasma spraying and consists of two sublayers - the lower metallic bond coating type CoNiCrAlY and top ceramic coating type YSZ. Low cycle fatigue tests were conducted under strain control at controlled temperature of 900 ° C. Fractographical analysis of fracture surfaces was carried out by using light and electron microscopy. Effect of applied barrier to fatigue life was determined - the parameters of Manson-Coffin and Basquin curve. A cyclic stress-strain curve was also obtained. The curves softening / hardening and number of transit cycles were determined. The obtained parameters and values from fatigue tests were compared with available data from fatigue tests of superalloy IN713LC without the layer, as applied AlSi type diffusion layer, at high temperatures. The initiation site on the fracture surfaces was determined within the fractographic evaluation and the influence of the layer on the initiation and propagation of fatigue cracks was discussed. A helpful tool was the assessment of longitudinal sections using scanning electron microscopy.

Cette étude porte sur la caractérisation des mécanismes d'adhésion et d'endommagement de produits colaminés à froid, afin de pouvoir proposer des procédés optimisés. Celle-ci s’inscrit dans le cadre de la participation au projet MeGaN (pour Module Electronique GaN) qui porte le développement de nouvelles technologies de modules de puissances à base de composants à grand gap « GaN », compatibles avec des applications hautes températures et hautes tensions. Notre travail porte essentiellement sur l’intégration d’un substrat innovant (i-TBC), un composite architecturé cuivre invar doté de ponts thermiques pour un bon compromis dialatation thermique/conductivité thermique pour accueillir les composants électroniques développés dans le cadre de ce projet. Ainsi, une première partie de ce travail est axée sur la caractérisation microstructurale du substrat i-TBC durant les étapes de son élaboration, l’objectif est de comprendre l’impact du procédé de colaminage sur la formation de l’adhésion des interfaces de cuivre dans les ponts thermiques. On a ainsi mis en évidence que la recristallisation de grains et la microstructure continue à travers l'interface Cu-Cu était garante d'une bonne adhérence de celle-ci. Dans la seconde partie, nous nous sommes focalisés sur la caractérisation de la tenue mécanique du substrat i-TBCdans des conditions de cycles thermiques passifs. Pour ce faire, des essais de fatigue thermique et de choc thermique nous permettent de déterminer la sensibilité de la tenue mécanique des interfaces à la fois à l’amplitude et à la vitesse de variation de température. La conclusion de cette étudeest que les paramètres de colaminage doivent permettent un compromis entreadhérence du pont Cu-Cu et des interfaces Cu-Invar pour augmenter significativement la durée de vie du composant. Enfin, nous avons procédé à l'analyse thermo-mécanique des propriétés intrinsèques du substrat seul et de l'assemblage électronique complet. Les propriétés intrinsèques ont été établies en termes de comportement mécanique du composite Cu-Invar et d'endommagement des interfaces sous la forme de propagation d'une fissure à l'interface Cu-Cu. / This work is part of ‘MeGaN” project which focuses on the development of new power module technologies based on "GaN" wide gap components, compatible with high temperature and high voltages applications. In This study, a new substrate an innovative thermal bridge composite (i-TBC) has been developed, obtained by roll bonding of two copper sheets separated by perforated invar. The i-TBC is an “architectured” composite material that combines good thermal conductivity associated to copper and limited CTE due to the presence of invar. A particularity of the i-TBC consists of the formation of copper bonding area through the invar perforations during the cold rolling called thermal bridges. These thermal bridges, ensure good thermal conductivity of the i-TBC. Thus, a first part of this work focuses on the microstructural characterization of the i-TBC substrate during the stages of its elaboration, the objective is to understand the impact of the elaboration steps on the adhesion formationof the copper interfaces. in thermal bridges. It was thus demonstrated that the cold welding obtained along the interface Cu-Cu was a guarantee of good adhesion. In the second part, we focused on the characterization of the mechanical strength of the i-TBC substrate under passive thermal cycling conditions. To do this, tests of thermal fatigue and thermal shock allow us todetermine the sensitivity of the mechanical resistance of the interfaces to both the amplitude and the speed of temperature variation. The conclusion of this study is that the parameters of cold rolling must allow a compromise between adhesion of the Cu-Cu bridge and Cu-Invar interfaces to significantly increase the lifetime of the substrate. Finally, a finite element analysis (FEA) wasperformed. firstly, the thermal modeling validated the thermal performance of the i-TBC substrate in an electronic assembly.Then, the intrinsic properties were established in terms of mechanical behavior of the Cu-Invar composite and deterioration of the interfaces in the form of propagation ofa crack at the Cu-Cu interface.

A doença da inflamação da glândula mamária, também conhecida como mastite, tem como uma das características o aumento de células somáticas no leite de quartos afetados. Entre as bactérias predominantes causadoras de mastites, destacam-se Staphylococcus spp. e Streptococcus spp. Vários estudos sugerem que estes agentes são tipicamente transmitidos de uma vaca para outra durante o momento da ordenha. A aplicação de programas de boas práticas de ordenha (BPO) permitem o controle da mastite pela eliminação de infecções detectadas no rebanho, prevenção de riscos e adequadas condições produtivas e sanitárias. A interação contínua entre produtores e técnicos tem se confirmado como ferramenta importante nos programas de treinamento, favorecendo o compartilhamento de experiências. Sendo assim, o presente estudo teve como objetivo avaliar a influência da capacitação técnica em BPO na qualidade higiênica do leite, mediante o monitoramento das práticas de ordenha implementadas, análises de componentes químicos e microbiológicos, incluindo a identificação de Staphylococcus spp. e Streptococcus spp., em propriedades leiteiras do estado de São Paulo. Na fase final do estudo foi observado que 84% dos itens de BPO avaliados estavam sendo usados com capacitação técnica, incluindo modificações de infraestrutura e controle da qualidade da fonte de água. O sucesso da aplicação de programas de controle da qualidade requerem o comprometimento dos produtores de leite. Entre as BPO que não foram adotadas, destacam-se o uso de luvas durante a ordenha e sanitizante na limpeza dos equipamentos, práticas que poderiam diminuir a transmissão dos patógenos contagiosos entre os animais. Embora as análises microbiológicas e identificação dos patógenos dos diferentes pontos de coleta tenham apresentado resultados variáveis ao longo do estudo, elas constituíram uma ferramenta importante durante o processo de capacitação técnica. / The mammary gland disease, also known as mastitis, has as characteristic the increase of somatic cells in milk from affected udder. Among the predominant bacteria causing mastitis, Staphylococcus spp. and Streptococcus spp are highlighted. Several studies suggest that these agents are typically transmitted from one cow to another during the milking. The application of programs on good milking practices (GMP) allows the control of mastitis through the elimination of infections detected in the herd, prevention of risks and proper productive and sanitary conditions. The continuous interaction between farmers and trainers has been confirmed as an important tool on training programs, supporting sharing experiences. Therefore, the present study aimed to evaluate the influence of GMP training on hygienic quality of milk, by monitoring milking practices implemented, chemical and microbiological analyzes, including the identification of Staphylococcus spp. and Streptococcus spp. in dairy farms from Sao Paulo state. In the final phase of this study it was demonstrated that 84% of the BPO evaluated items were being used with training including infrastructure modifications and quality control of the water source. The success of the implementation of quality control programs requires the commitment of dairy farmers. The GMP not adopted included the use of gloves during milking and sanitizers on equipment cleaning, practices that could reduce the transmission of contagious pathogens among animals. Although the microbiological analyses of the pathogens in different points on the milking management were inconstant during the study, they constitute an important tool during the training process.

A doença da inflamação da glândula mamária, também conhecida como mastite, tem como uma das características o aumento de células somáticas no leite de quartos afetados. Entre as bactérias predominantes causadoras de mastites, destacam-se Staphylococcus spp. e Streptococcus spp. Vários estudos sugerem que estes agentes são tipicamente transmitidos de uma vaca para outra durante o momento da ordenha. A aplicação de programas de boas práticas de ordenha (BPO) permitem o controle da mastite pela eliminação de infecções detectadas no rebanho, prevenção de riscos e adequadas condições produtivas e sanitárias. A interação contínua entre produtores e técnicos tem se confirmado como ferramenta importante nos programas de treinamento, favorecendo o compartilhamento de experiências. Sendo assim, o presente estudo teve como objetivo avaliar a influência da capacitação técnica em BPO na qualidade higiênica do leite, mediante o monitoramento das práticas de ordenha implementadas, análises de componentes químicos e microbiológicos, incluindo a identificação de Staphylococcus spp. e Streptococcus spp., em propriedades leiteiras do estado de São Paulo. Na fase final do estudo foi observado que 84% dos itens de BPO avaliados estavam sendo usados com capacitação técnica, incluindo modificações de infraestrutura e controle da qualidade da fonte de água. O sucesso da aplicação de programas de controle da qualidade requerem o comprometimento dos produtores de leite. Entre as BPO que não foram adotadas, destacam-se o uso de luvas durante a ordenha e sanitizante na limpeza dos equipamentos, práticas que poderiam diminuir a transmissão dos patógenos contagiosos entre os animais. Embora as análises microbiológicas e identificação dos patógenos dos diferentes pontos de coleta tenham apresentado resultados variáveis ao longo do estudo, elas constituíram uma ferramenta importante durante o processo de capacitação técnica. / The mammary gland disease, also known as mastitis, has as characteristic the increase of somatic cells in milk from affected udder. Among the predominant bacteria causing mastitis, Staphylococcus spp. and Streptococcus spp are highlighted. Several studies suggest that these agents are typically transmitted from one cow to another during the milking. The application of programs on good milking practices (GMP) allows the control of mastitis through the elimination of infections detected in the herd, prevention of risks and proper productive and sanitary conditions. The continuous interaction between farmers and trainers has been confirmed as an important tool on training programs, supporting sharing experiences. Therefore, the present study aimed to evaluate the influence of GMP training on hygienic quality of milk, by monitoring milking practices implemented, chemical and microbiological analyzes, including the identification of Staphylococcus spp. and Streptococcus spp. in dairy farms from Sao Paulo state. In the final phase of this study it was demonstrated that 84% of the BPO evaluated items were being used with training including infrastructure modifications and quality control of the water source. The success of the implementation of quality control programs requires the commitment of dairy farmers. The GMP not adopted included the use of gloves during milking and sanitizers on equipment cleaning, practices that could reduce the transmission of contagious pathogens among animals. Although the microbiological analyses of the pathogens in different points on the milking management were inconstant during the study, they constitute an important tool during the training process.

Thermal barrier coatings (TBCs) of ZrO2-7wt% Y2O3 were deposited by electron beam physical vapor deposition (EB-PVD) onto stationary flat plates and cylindrical surfaces in a multiple ingot coater. Crystallographic texture, microstructure, and deposition rate were investigated in this thesis. The crystallographic texture of EB-PVD TBCs deposited on stationary flat surfaces has been experimentally determined by comparing pole figure analysis data with actual column growth angle data. It was found that the TBC coating deposited directly above an ingot exhibits <220> single crystal type crystallographic texture. Coatings deposited between and off the centerline of the ingots the exhibited a <311>-type single crystal texture. For coatings deposited in the far corners of the coating chamber either a <111> fiber texture or a <311> single crystal type texture existed. The crystallographic texture of EB-PVD TBCs deposited on cylindrical surfaces was characterized using x-ray diffraction (XRD) at different angular positions on the cylinder substrate. XRD results revealed that crystallographic texture changes with angular position. Changes in crystallographic texture are attributed to the growth direction of the columns and substrate temperature. Growth direction is controlled by the direction of the incoming vapor flux (i.e. vapor incidence angle), in which competition occurs between crystallites growing at different rates. The fastest growing orientation takes over and dominates the texture. Substrate temperature variations throughout the coating chamber resulted in different growth rates and morphology. Morphology differences existed between cylindrical and flat plate surfaces. Flat cross sectional surfaces of the coatings exhibited a dense columnar structure in which the columns grew towards the closest vapor source. Surface features were found to be larger for coatings deposited directly above an ingot than coatings deposited away from the ingots. Morphological differences result from substrate temperature changes within the coating chamber, which influences growth kinetics of the coating. Cylindrical surfaces revealed a columnar structure in which columns grew towards the closest vapor. Porosity of the coating was found to increase when the angular position changed from the bottom of the cylinder. Change in angular position also caused the column diameter to decreases. Morphology changes are attributed to self-shadow effects caused by the surface curvature of the cylinder and vapor incidence angle changes. Overall, the microstructure and crystallographic texture of EB-PVD coatings was found to depend on the position in the coating chamber which was found to influence substrate temperature, growth directions, and shadowing effects. The coating thickness profiles for EB-PVD TBCs deposited on stationary cylinders have been experimentally measured and theoretically modeled using Knudsen's cosine law of emissions. A comparison of the experimental results with the model reveals that the model must to be modified to account for the sticking coefficient as well as a ricochet factor. These results are also discussed in terms of the effects of substrate temperature on the sticking coefficient, the ricochet factor, and coating density.

Sverige har under många decennier sett en minskning av tuberkulos (TBC), men infektionen har kontinuerligt ökat från 2003. Majoriteten av TBC-fallen är personer som är födda utanför Sverige. Hälsotillståndet har förbättrats i Sverige men det finns fortfarande problem. Kommunikationen mellan flyktingar och sjukvårdsspecialister är bristande idag, vilket resulterar att endast ett fåtal genomgår hälsokontroller. Detta kan leda till en ökning av infektioner och sjukdomar i Sverige. Denna studie undersöker hur hälsokommunikationen idag fungerar mellan den svenska sjukvården, nyanlända immigranter, asylsökande och flyktingar, samt vilken typ av vård som finns tillgänglig för flyktingar med hög risk för att utveckla TBC. Specifikt syftar studien till att förstå på vilket sätt kommunikation brister på samt analysera vilka sätt det finns för att en reducering av TBC i Sverige ska kunna ske och hur kommunikationen kan förbättras. Studien har genomförts med hjälp av både primära källor i form av intervjuer och sekundära källor. Baserat på de intervjuer och sekundära källor som genomförts i studien dras slutsatsen att trots att den svenska sjukvården utvecklas positivt så finns det en hel del brister - hälsokommunikation är bristande idag mellan nyanlända flyktingar, sjukvårdspersonal och myndigheter. En av huvudorsakerna som informanterna i studien nämnt är språket, mycket av det som skrivs och sägs är på svenska. Det är viktigt att en mer välfungerad hälsokommunikation utvecklas mellan de nyanlända flyktingarna, sjukvårdspersonal och myndigheterna för att det ska kunna underlättas för flyktingar att söka vård och samarbeta med sjukvårdspersonal med deras arbete för att kunna förhindra spridning av TBC och andra sjukdomar och infektioner i Sverige. / Sweden has for many decades witnessed a decrease of the spread of tuberculosis (TB), but between the years of 2003-2012 a new pattern has emerged with refugees carrying TB entering the country and contributing to a situation where the infection has slowly begun to spread again. The communication between the refugees and the health professionals has been inefficient, which inevitably results in fewer refugees undergoing health examinations. This in turn can lead to an increase of infections and diseases. The purpose of this study is to examine the current health communication between Swedish health professionals and immigrants, asylum seekers and refugees, and to give an overview of what type of health care currently exist for refugees with a high risk of TB. This is done to understand what is missing in the communication process, what has been done in order to improve the situation, and how it can be further improved in order to prevent TB. In order to fulfill the purpose of this study, a qualitative method has been used combining text analysis of interviews and secondary sources. This study has shown based on the interviews and secondary sources that the Swedish prevention work regarding TB is developing positively in general, but the communication between newly arrived refugees, health professionals and authorities in Sweden is lacking due to the fact that most of what is written and said in this communication process is in Swedish. This makes it difficult for the refugees to understand what is communicated and is stated as one of the main reasons why many refugees do not undergo health examinations, combined with the lack of awareness. Therefore a better functioning health communication between refugees, authorities and health professionals is required to support refugees seeking health care, as well as co-operating with health professionals to prevent the spread of not only TB but other infections and diseases in Sweden.

No description available.

The membrane trafficking system mediates delivery of macromolecules and metabolites to discrete intracellular compartments from their site of uptake or synthesis. For many pathogens the trafficking system has a special relevance as it is responsible for maintaining the host-pathogen interface, i.e., the cell surface. Both the surface and the underlying trafficking apparatus are intimately connected with immune evasion in many parasites including those belonging to the highly divergent order Kinetoplastida. Kinetoplastid parasites are etiological agents of several neglected tropical diseases such as African sleeping sickness, Chagas disease, and Leishmaniasis. Newly available sequences of many kinetoplastid genomes were used to reconstruct evolution of trafficking across this lineage, using three central paralogous trafficking families: Rabs, SNAREs and Rab-GAPs, which have defined roles in specific trafficking events. Further, proteomics was used to analyse a representative SNARE complex to explore compositional conservation between kinetoplastids and Opistokhonts. Overall there is little evidence for large scale expansions or contractions of these protein families, excluding a direct association with parasitism or changes to host range, host immunosophistication or transmission mechanisms. The data indicate a stepwise sculpting of the trafficking system where the large repertoire of the basal bodonids is mainly retained by the cruzi group, while extensive lossses characterise other lineages, particularly the African trypanosomes and phytomonads. Kinetoplastids possess several lineage-specific Rabs but all retain a core canonical Rab set; by contrast there is little novelty within the SNARE family even though certain canonical endosomal SNAREs appear to show a considerable degree of sequence divergence. Proteomics suggests that SNARE complex composition is largely conserved. The major changes in Rab and SNARE repertoires are associated with endosomal and late exocytic pathways, which is consistent with the considerable evolution of surface proteomes. Therefore, despite the absence of a transition per se associated with parasitism, adaptation of membrane trafficking is likely under active selection where it meets the host environment.