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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Formulace a testování nanočástic z větvených polyesterů s siRNA / Formulation and testing of siRNA-loaded branched polyesters nanoparticles

Medviďová, Simona January 2018 (has links)
Charles University Faculty of Pharmacy in Hradcec Králové Department of Pharmaceutical Technology Supervisor: doc. RNDr. Milan Dittrich, CSc. Student: Simona Medviďová Title of thesis: Formulation and testing of branched polyesters siRNA-loaded nanoparticles The progression of development increases demand for new and more effective drug systems formulations. This diploma thesis is focused on the preparation of nanoparticles from biodegradable branched polyesters based on PLGA, which are suitable for the transport of an oligonucleotide of a small interfering nucleic acid, siRNA. The theoretical part focuses on the characteristics of usable polymers, their possible modifications, the methods of preparation with closer look at the selected nanoprecipitation method, the important parameters such as particles size, zeta potential, and polydispersity. The main part is also characterization of siRNA in terms of structure, properties, modifications, and its function. A more extensive experimental part deals with the appropriate choice of type and concentration of polyester and stabilizer, methods of preparation and characterization of nanoparticles, and the possibility of analyzing encapsulated siRNA. Chapters results and discussion compares polyesters branched on tripentaerythritol, and polyacrylic acid...
302

Contribution à l'étude des leishmanioses en Iran : Phlébotomes, parasites, réservoirs et Homme / Contribution to the study of leishmaniasis in Iran : Sandflies, parasites, reservoirs and human

Akhoundi Sheikhahmadlou, Mohammad 21 February 2013 (has links)
Notre travail est une contribution à l'étude des leishmanioses en Iran. Il s'est focalisé sur trois volets. Le principal concerne les Phlébotomes. Les deux autres sont constitués par les Rongeurs réservoirs de L. major et l'Homme.L'étude des phlébotomes s'est réalisée selon deux axes : systématique et épidémiologique. Les approches de systématique nous a conduit à réaliser des inventaires faunistiques dans plusieurs régions d'Iran (nord-ouest, Nord-est, est et centre du pays). Ces inventaires nous ont permis de réactualiser la distribution de certains groupes, notamment les phlébotomes du sous-genre Adlerius et de mentionner deux espèces nouvelles pour la faune du l'Iran : Phlebotomus turanicus et P. salangensis. A côté de ces travaix de faunistique, nous avons réalisé deux travaux de systématique évolutive qui couplent des approches morphologique et morphométrique à des approches moléculaires associant un marqueur ribosomique à un marqueur mitochondrial. Nous avons ainsi étudié P. perfiliewi s.l. et le sous-genre Adlerius sur un échantillonnage débordant largement le cadre de l'Iran. Les travaux d'épidémiologie nous ont permis de vérifier que les foyers que nous avons étudiés fonctionnent sur un mode classique dans lequel P. papatasi, et à un degré probablement moindre les femelles du groupe Caucasicus transmettent Leishmania major alors que P. sergenti assure la transmission de L. tropica. L'identification des parasites est réalisée par voie moléculaire : PCR et RFLP et/ou séquençage de marqueurs ribosomiques. L'étude des Rongeurs réservoirs de L. major nous a permis de constater le rôle essentiel de réservoir de Rhombomys opimus et de Meriones libycus dans le pays avec l'observation de prévalences très élevées, supérieures à 30 % chez ces espèces.Enfin, une étude a été conduite dans la region de Fars où sévissent classiquement des leishmanioses à L. major, L. tropica et à L. infantum. Chez 44 patients présentant des lésions cutanées, nous avons isolé et identifié essentiellement L. major et quelques souches de L. tropica. / This work focused on the leishmaniases in Iran. It includes three topics: i) the Phlebotomine sand flies, ii) the rodent reservoirs of Leishmania major and iii) the Humans.The entomological studies concern both systematics and epidemiology.The systematic part of the study of Phlebotomine sand flies includes several inventories carrired out in several provinces of Iran (North-West, North-East, East and Center of the country). Our results update the distribution of the subgenus Adlerius. We also recorded two new species for the fauna of Iran: Phlebotomus turanicus and P. salangensis. We also carried out evolutive and comparative systematics including specimens from Iran, neighbouring and Mediterranean countries. We coupled morphology to morphometrics and molecular systematics. In the latter approach, we coupled a ribosomal DNA marker to a mitochondrial one. We studied P. perfiliewi s.l. and the subgenus Adlerius. Our epidemiological works focusing on the epidemiology in several parts of the country showed that the studied foci are classical: P. papatasi, and also the females of the Caucasicus group transmit Leishmania major whereas P. sergenti is the vector of L. tropica.The identification of the Leishmania has been done using PCR then RFLP and/or sequencing of rDNA Internal Transcribed Spacer 1.We studied the rodent reservoirs of L. major. Rhombomys opimus and Meriones libycus play an important role and the percentage of L. major infection is high (> 30%).Lastly, we carried out a study on patients from the province of Fars. In this area, leishmaniases are due to L. major, L. tropica and L. infantum. We have typed strains isolated from 42 ot 44 patients. The majority of the strains have been identified as L. major and a few L. tropica.
303

Influência do teor de carbono na formação da camada de nitretos e nas propriedades mecânicas em aços da família 43XX submetidos à nitretação a plasma / Carbon content influence on the formation of the nitride layer and on the mechanical properties of steels from 43XX subjected to plasma nitriding treatment

Sakamoto, Felipe Sannomiya 16 February 2018 (has links)
Submitted by Felipe Sannomiya Sakamoto (fesaka@gmail.com) on 2018-04-11T20:16:37Z No. of bitstreams: 1 Dissertação - Felipe Sannomiya Sakamoto.pdf: 6137098 bytes, checksum: a32159d8a079ea4c53b2bde7e050c4ad (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-04-13T17:13:01Z (GMT) No. of bitstreams: 1 sakamoto_fs_me_guara.pdf: 6137098 bytes, checksum: a32159d8a079ea4c53b2bde7e050c4ad (MD5) / Made available in DSpace on 2018-04-13T17:13:02Z (GMT). No. of bitstreams: 1 sakamoto_fs_me_guara.pdf: 6137098 bytes, checksum: a32159d8a079ea4c53b2bde7e050c4ad (MD5) Previous issue date: 2018-02-16 / Os aços de alta resistência da série AISI 43XX apresentam importantes aplicações na indústria aeroespacial e automobilística. Devido as suas características, podem atingir altos limites de escoamento e resistência. A presença de elementos de liga como cromo, molibdênio e níquel juntamente com o teor de carbono, variando neste estudo de 0,20 a 0,70 %, podem promover melhorias nas propriedades mecânicas. O tratamento de superfície de nitretação utilizado pode promover melhorias nas propriedades de corrosão, desgaste e aumento da dureza superficial. Neste estudo foi aplicado o tratamento de nitretação a plasma em amostras dos aços da família AISI 43XX e foi avaliada, de forma comparativa, as alterações na superfície e na microestrutura dos aços nitretados em relação aos não nitretados. A elevação do teor de carbono pode dificultar ou reduzir a formação da camada de nitretos, portanto, é importante avaliar a influência do percentual de carbono nestas estruturas. As características microestruturais foram analisadas por microscopia óptica, microdureza e difração de raios-X. Foram também estudadas a influência do teor de carbono no aço apenas temperado e temperado e revenido. Com o aumento do teor de carbono do aço foi observada a elevação na dureza do aço temperado ou apenas recozido. O tratamento termoquímico de nitretação a plasma elevou a dureza da superfície para valores em torno de 800 HV, dureza superior à encontrada no substrato. A profundidade da zona de difusão de nitrogênio foi menor para os aços com teores de carbono mais elevados. A autenita retida aumentou juntamente com o teor de carbono, mas só foi possível quantificar a fração volumétrica desta fase pela microscopia óptica, uma vez que, pela técnica de difração de raio X, é de difícil detecção concentrações abaixo de 5% ou distribuídas de forma fina e homogênea. / The high strenght steel from series AISI 43XX are heavely applied on the aerospacial and automotive industry. Due to their chacteristics, they reach high yield values and resistence levels. The presence of chrome, nickel and molybdenum allied with the carbon content, from 0,20 to 0,70% in this study, can provide improvements on the mechanical properties. The nitriding surface threatment used may provide improvement on corrosion, wear properties and increase the surface hardness. In this study was applied the nitriding plasma threatment on samples of family 43XX steel and was evaluated, on comparative basis, the alterations on the surface and in the microstructure of nitrided steels in comparison to not nitrided steels. Higher carbon content may hamper or reduce the nitrides deposition, therefore, it is important to evaluate the influence of the carbon concentration in theses structures. The microstructure characteristics were analysed by optical microscopy, microhardness and X-ray difraction. The nitriding plasma thermochemical threatment raised the surface hardness to values of about 800 HV, higher than the values measured in the substract. The nitrogen diffused zone of higher carbon content steels was thicker than the lower. The content of arrested austenite increased as the carbon contend increased, but was just possible to measure it by optical microscopy, because it is difficult to measure lower contents than 5% or homogen and thick distributed by X-ray difraction.
304

Caractérisation des structures composites bobinées épaisses, application à l’étude du comportement de réservoirs de stockage d’hydrogène

Pilato, Aurélie 09 December 2011 (has links)
Ce travail de thèse s'est déroulé dans le cadre du programme H2E (Horizon Hydrogène Énergie) piloté par Air Liquide et en partenariat industriel avec Composites Aquitaine. Le stockage d’hydrogène sous forme gazeuse impose que les réservoirs bobinés en composite carbone/époxy utilisés résistent à des pressions internes en service allant de 350 à 700bar.L’état de l’art montre que le procédé d’enroulement filamentaire et son application à des épaisseurs de matériaux composites importantes peuvent générer des variations, dans l’épaisseur, des contraintes résiduelles d’origine thermique, de la teneur en fibres et en porosités et de l’épaisseur des couches. Ces hétérogénéités peuvent alors être à l’origine de modifications des propriétés mécaniques du composite. Notre travail s’est donc appuyé sur la caractérisation physico-chimique à l’échelle des constituants (mesure de températures, nano-indentation, analyse d’images et microtomographie) ainsi que la caractérisation mécanique à l’échelle de la couche de référence mais également à l’échelle de la structure (essais plans spécifiques sur éprouvettes bobinés et essais hors-plan).Les hétérogénéités de la matière ainsi identifiées sur le réservoir ont été intégrées dans un modèle de calcul analytique permettant d'étudier leurs influences sur sa pression d'éclatement. La conception d'un essai de mise sous pression interne d'un anneau a par ailleurs permis de vérifier le comportement mécanique de la structure réelle. / This PhD work was conducted in the H2E (Horizon Hydrogen Energy) program coordinated by Air Liquide and with the industrial partnership of Composites Aquitaine. The hydrogen storage under gaseous form needs the filament-wound carbon/epoxy composite vessels used to resist to service pressures between 350 to 700bar.The influences of the process and of the thickness of the structure on its mechanical behaviour were determined by precise bibliographic work and were supposed to generate thermal residual stresses and also to be responsible of variations in the thickness and fibre content of the plies. These heterogeneities could modify the mechanical properties of the composite material. Our work focuses, first of all, on the physical chemistry characterization at the constituents scale (temperature measurement, nano-indentation, image analysis and microtomography) and then on the mechanical characterization of the reference ply and also of the structure (dedicated tests on filament-wound samples and out-of-plane tests).The material heterogeneities identified on the vessel were integrated in an analytical calculation model to study their influences on its burst pressure. The development of an internal pressure test allows us to verify the global mechanical behaviour of the real structure.
305

Toxicidade, caracterização molecular de bacillus sphaericus da amazônia e parâmetros do crescimento microbiano para a produção de bioinseticida.

Litaiff, Eleilza de Castro 03 April 2006 (has links)
Made available in DSpace on 2015-04-20T12:31:08Z (GMT). No. of bitstreams: 1 eleilza.pdf: 788700 bytes, checksum: 7900cf61a2a7a4d6a517f73e27656735 (MD5) Previous issue date: 2006-04-03 / Larvicidal activity of B. sphaericus from several places in Amazonia, was estimated to Anopheles darlingi and Culex quinquefasciatus. Pobit analysis was used to determine the median lethal concentration (LC50) and potency relative to the 2362 standard strain. Findings pointed out strains IB15 (LC50 = 0.040 ppm), IB19 and S1116 (LC50 = 0.048 ppm), IB16 (LC50 = 0.052 ppm) and S265 (LC50 = 0.057 ppm) as the most effective ones, being IB15 with a potency of close to 50%, higher to strain 2362 in the assays carried out with A. darlingi. IB16 and S1116 were more potent in the experiments with C. quinquefasciatus, showing to be nearly 300-400% higher. Through molecular characterisation were diagnosed the binary toxin gene in all twenty studied stains and MTX1 toxin was found only on fourteen of them. Twenty-three polymorphic sites on the sequences were observed on the basis of the BinA sequences, being only four of them informative for the parsimony. As a whole, ten haplotypes were obtained amongst the Amazonian strains, being haplotype 1 (nine strains) similar to that of 2362 (Type 2) and the rest presenting distinct sequences. The 16 polymorphic sites observed on the aminoacid sequences resulted into 19 variant aminoacids and, on the basis of the genetic distance among the strains, it was not possible to establish a correlation between variations on BinA toxin sequences and toxicity level, as well as precedence of the strains. As B. sphaericus raises biotechnological interest in the production of biolarvicides, IB15 strain microbial growth in NYSM medium during 24h of fermentation, was studied. It was found that IB15 presented a growth profile similar to 2362 strain to prduction of cells, spores, biomass and larvicidal activity throughout fermentation, with no statistically significant differences. At the end, 1.61x109 spores.mL-1 was obtained with IB15 and 6.46x108 spores.mL-1 with 2362. LT50 values were similar, being in average 2.5h in the experiments with one culture of the bacillus at the end of 24 hours. Strain IB15 showed to be suitable for growth in NYSM medium, presenting desirable levels of production of spores and toxins throughout fermentation. Further studies are needed on the large-scale production with that strain for the development of biolarvicides. Therefore, with the findings obtained in this study, one verifies the great importance of mosquito biological control with the use of entomopathogenic bacteria, showing to be a viable complement or alternative on the control of vector mosquitoes in Amazonia. / A atividade larvicida de B. sphaericus, procedentes de diversas localidades da Amazônia, foi estimada por meio de bioensaios com Anopheles darlingi e Culex quinquefasciatus. Pela análise de Probit foi determinada a concentração letal mediana (CL50) e a potência em relação à estirpe padrão 2362. Os resultados apontaram as estirpes IB15 (CL50 = 0,040 ppm), IB19 e S1116 (CL50 = 0,048 ppm), IB16 (CL50 = 0,052 ppm) e S265 (CL50 = 0,057 ppm) como mais efetivas, sendo IB15 com potência cerca de 50% superior à estirpe 2362 nos bioensaios realizados contra A. darlingi e IB16 e S1116 mais potentes nos testes com C. quinquefasciatus, mostrando-se cerca de 300-400% superiores. Na caracterização molecular o gene da toxina binária foi diagnosticado em todas as estirpes estudadas e a toxina MTX1 foi observada em apenas quatorze estirpes. Com base nas sequências de BinA, foram observados 23 sítios polimórficos nas sequências, sendo apenas quatro informativos para parcimônia. Ao total obteve-se dez haplótipos entre as estirpes da Amazônia, sendo o haplótipo 1 (nove estirpes) similar a 2362 (Tipo 2) e o restante com sequências distintas. Os 16 sítios polimórficos observados nas sequências de aminoácidos resultaram em 19 aminoácidos variantes e, com base na distância genética, não foi possível estabelecer uma correlação entre variações nas sequências da toxina BinA e o nível de toxicidade, bem como a procedência das estirpes. Como B. sphaericus desperta um interesse biotecnológico na produção de biolarvicidas para controle de mosquitos vetores, foi estudado o crescimento microbiano da estirpe IB15 em meio NYSM, durante 24 horas de fermentação. IB15 apresentou um perfil de crescimento semelhante à estirpe 2362 quanto às produções de células, esporos, biomassa e em atividade larvicida ao longo da fermentação. Ao final, obteve-se 1,61x109 esporos.mL-1 com IB15 e 6,46x108 esporos.mL-1 com 2362. Os valores de TL50 foram semelhantes, sendo em média 2,5h nos testes com uma cultura do bacilo ao final de 24 horas. A estirpe IB15 demonstrou ser adequada para crescimento em meio NYSM, apresentando níveis desejados de produção de esporos e toxinas ao longo da fermentação. São necessários estudos complementares sobre produção em grande escala com essa estirpe para o desenvolvimento de biolarvicidas. Portanto, com os resultados obtidos nesse trabalho, verifica-se a grande importância do controle biológico de mosquitos com o emprego de bactérias entomopatogênicas, mostrando ser uma alternativa ou complemento viável no controle de mosquitos vetores na Amazônia.
306

Uma contribuição para o teste baseado em defeitos de software orientado a aspectos / A contribution to the fault-based testing of aspect-orientd software

Fabiano Cutigi Ferrari 16 December 2010 (has links)
A Programação Orientada a Aspectos (POA) é uma técnica contemporânea de desenvolvimento de software fortemente baseada no princípio da separação de interesses. Ela tem como objetivo tratar de problemas de modularização de software por meio da introdução do aspecto como uma nova unidade de implementação que encapsula comportamento relacionado aos interesses transversais do software. A despeito dos benefícios que podem ser alcançados com o uso da POA, seus mecanismos de implementação representam novas potenciais fontes de defeitos que devem ser tratados durante a fase de teste de software. Nesse contexto, o teste de mutação consiste em um critério de seleção de testes baseado em defeitos que tem sido bastante investigado para demonstrar a ausência de defeitos pré-especifiados no software. Acredita-se que o teste de mutação seja uma ferramenta adequada para lidar com as particularidades de técnicas de programação contemporâneas como a POA. Entretanto, até o presente momento, as poucas iniciativas para adaptar o teste de mutação para o contexto de programas orientados a aspectos (OA) apresentam cobertura limitada em relação aos tipos de defeitos simulados, ou ainda requerem adequado apoio automatizado e avaliações. Esta tese visa a mitigar essas limitações por meio da definição de uma abordagem abrangente de teste de mutação para programas OA escritos na linguagem AspectJ. A tese inicia como uma investigação da propensão a defeitos de programas OA e define uma taxonomia de defeitos para tais programas. A taxonomia inclui uma variedade de tipos de defeitos e serviu como base para a definição de um conjunto de operadores de mutação para programas OA. Suporte automatizado para a aplicação dos operadores também foi disponibilizado. Uma série de estudos quantitativos mostra que a taxonomia de defeitos proposta é suficiente para classificar defeitos encontrados em vários sistemas OA. Os estudos também mostram que os operadores de mutação propostos são capazes de simular defeitos que podem não ser relevados por conjuntos de teste pré-existentes, não derivados para cobrir mutantes. Além disso, observou-se que o esforço requerido para evoluir tais conjuntos de teste de forma a torná-los adequados para os requisitos gerados pelos operadores / Aspect-Oriented Programming (AOP) is a contemporary software development technique that strongly relies on the Separation of Concerns principle. It aims to tackle software modularisation problems by introducing the aspect as a new implementation unit to encapsulate behaviour required to realise the so-called crosscutting concerns. Despite the benefits that may be achieved with AOP, its implementation mechanisms represent new potential sources of faults that should be handled during the testing phase. In this context, mutation testing is a widely investigated fault-based test selection criterion that can help to demonstrate the absence of prespecified faults in the software. It is believed to be an adequate tool to deal with testing-related specificities of contemporary programming techniques such as AOP. However, to date, the few initiatives for customising the mutation testing for aspect-oriented (AO) programs show either limited coverage with respect to the types of simulated faults, or a need for both adequate tool support and proper evaluation. This thesis tackles these limitations by defining a comprehensive mutation-based testing approach for AO programs written in the AspectJ language. It starts with a fault-proneness investigation in order to define a fault taxonomy for AO software. Such taxonomy encompasses a range of fault types and underlay the definition of a set of mutation operators for AO programs. Automated tool support is also provided. A series of quantitative studies show that the proposed fault taxonomy is able to categorise faults identified from several available AO systems. Moreover, the studies show that the mutation operators are able to simulate faults that may not be revealed by pre-existing, non-mutation-based test suites. Furthermore, the effort required to augment the test suites to provide adequate coverage of mutants does not tend to overwhelm the testers. This provides evidence of the feasibility of the proposed approach and represents a step towards the practical fault-based testing of AO programs
307

Structural characterisation and in vitro behaviour of apatite coatings and powders.

Etok , S E 17 November 2009 (has links)
Hydroxyapatite (HAP) coatings are used in orthopaedic surgery for bone regeneration. Current methods of phase quantification of HAP coatings suffer from drawbacks. A novel methodology of quantitative phase analysis of HAP coatings has been devised and validated. This method, based on whole pattern fitting with a fundamental parameters approach, incorporates amorphous calcium phosphate (ACP) and apatite phases into structural refinements. A comparison of the structural and chemical properties of plasma sprayed (PS) and novel electrodeposited (ED) HAP coatings has been conducted. ED coatings contained less ACP and more preferred orientation than the PS coatings, although the stoichiometry was similar. In vitro investigations of PS and ED coatings in simulated body fluid and foetal calf serum revealed that both are bioactive. A carbonated apatite layer produced on the ED coatings was -0.7μm thick with a stoichiometry and chemical constituents similar to that of natural bone apatite. PS coatings produced a nanocrystalline carbonated apatite layer (-4μm). For the first time it has been possible to model crystalline HAP and nanocrystalline apatite as independent phases and obtain accurate lattice parameters for each. A positive linear correlation has been made between microstrain and the solubility of HAP and carbonated apatites. Dissolution studies have shown that the behaviour of HAP and carbonated apatite is dominated by crystallite size at low undersaturation and by crystallite size and microstrain at high undersaturation for crystallites between -30OA- 1000A. Metastable equilibrium occurred for crystallites <_400A at low undersaturation. Carbonate content did not affect the solubility or dissolution behaviour. A novel technology for coating polymeric tape with HAP for potential use in anterior cruciate ligament reconstruction has been devised. Mechanical tests have demonstrated that no adverse properties are induced by the coating technology. Cell culture studies have shown that the HAP layer is capable of enhanced attachment, proliferation and differentiation of osteoblast cells compared to uncoated tape.
308

Intertextuality as a politeness strategy : A qualitative study of the use and function of intertextuality in the television series Suits

Brandström, Felicia January 2014 (has links)
This paper investigates the use and function of intertextuality in the television series Suits, and examines the interplay between intertextuality and politeness. Intertextuality allows a text to incorporate other texts and to draw upon connotations that belong to those texts. Politeness theory offers a tool to analyse the pragmatic use of language in social interaction. Analysing occurrences of intertextuality from the first episode of the television series, the paper explores in what ways the fictional characters use intertextuality and for what purposes. It explores if, and how, intertextuality can be used as a politeness strategy. Findings suggest that intertextuality is used for three main purposes, and functions as characterisation and as a means to establish and/or maintain social relations. Detailed analyses of instances of intertextuality propose that intertextuality can be used as a politeness theory, but only in certain ways. The paper discusses these findings and offers a possible explanation for why intertextuality is only used in this restricted way.
309

Etude numérique et expérimentale de la croissance de couches minces déposées par pulvérisation réactive. / Numerical and experimental study of thin films’ growth deposited by reactive sputtering.

Siad, Ahcene 25 November 2016 (has links)
L’objectif de ce travail est de déterminer expérimentalement les paramètres d’entrée des logiciels de simulation, puis de comparer les résultats expérimentaux et numériques pour différents métaux ainsi que pour leurs oxydes. La configuration GLAD a été volontairement choisie pour les structures inclinées particulières qu’elle permet.Le processus de formation de dépôt en phase vapeur (PVD) peut être divisé en trois étapes : l'éjection d'atomes de la cible, le transport vers le substrat et la croissance des couches minces. Chacune est simulée par un logiciel : SRIM pour l’éjection de matière de la cible suite à l’impact avec un ion, SIMTRA pour le transport des atomes de la cible jusqu’au substrat et Simul3D pour la croissance des dépôts. L’évolution des propriétés des couches inclinées (angle d’inclinaison des colonnes β, épaisseur de la couche, contraintes résiduelles, etc) en fonction de la position et de l’angle d’orientation du substrat est étudiée.Les résultats expérimentaux et numériques se complètent mutuellement et permettent une meilleure compréhension des nombreux aspects de l’étude. / The objective of the present work is to determine experimentally the input parameters of the modelling software and then to compare experimental and numerical results in the case of different metals and their oxides. The GLAD configuration was deliberately chosen for the particular angled structures it allows.The Physical Vapor Deposition (PVD) process can be divided in three steps: ejection of atoms from the target, transport to the substrate and growth of the thin films. Different softwares have been developed for each step: SRIM is a computer program that calculates the interactions of energetic ions; SIMTRA simulates the transport of the atoms from the target to the substrate and Simul3D simulates the growth of the film. The evolution of the thin angled films’ properties (column tilt angles β, thickness, residual stress, etc.) versus the orientation of the substrate is studied.The experimental and numerical results complement each other and allow a better understanding of the many aspects of the study.
310

Application des caractérisations de surface par XPS, ToF-SIMS, SIMS, EELS, SEM, AFM et TEM à la compréhension des mécanismes de protection antimicrobienne de textiles modifiés par traitements de surface / Application of surface characterisation by X-ray photoelectron Spectroscopy (XPS), Time of Flight –Secondary Ion Mass Spectrometry (ToF-SIMS), Static Secondary Ion Mass Spectrometry (SIMS), electron Energy Loss Spectroscopy (EELS), Scanning Electron Microscopy (SEM), Atomic force miccorscopy (AFM) and Transmission Electron Microscopy (TEM) to understand the mechanisms of antimicrobial protection of textiles modified by suface treatments

Brunon, Céline 13 December 2010 (has links)
Ce travail de thèse s’inscrit dans la partie caractérisation d’un projet collaboratif ayant pour objectif d’élaborer des textiles antimicrobiens pour différents domaines d’application, en particulier les domaines de la santé et de l’agroalimentaire. La démarche analytique a consisté à combiner différentes techniques d’analyse de surface (techniques microscopiques (SEM, AFM, TEM) et spectroscopiques (XPS, ToF-SIMS, SIMS, EELS)) avec des analyses microbiologiques pour aider à la compréhension des mécanismes de protection antimicrobienne des textiles traités. Les agents antimicrobiens, l’argent et le Poly HexaMéthylène Biguanide (PHMB), ont été déposés respectivement par plasma (PVD / PECVD) et par foulardage. Les contraintes liées aux domaines d’application des textiles étudiés (implants herniaires et vêtements professionnels) ont été prises en compte (respectivement, quantité minimale de l’agent antimicrobien et résistance au lavage industriel). Malgré certaines contaminations inhérentes à des procédés industriels, les analyses de surface se sont révélées être un ensemble d’outils essentiel au développement des procédés (qualité du dépôt, influence des conditions de dépôt, influence du lavage). Selon les domaines d’application, l’analyse à très haute sensibilité en extrême surface et l’étude de la distribution en profondeur de l’agent antimicrobien ont été des étapes clés pour la compréhension des propriétés antimicrobiennes observées pour les dépôts, démontrant la pertinence de l’approche multi-analytique choisie dans ce travail de thèse / This thesis work concerns the characterization effort within a cooperation project aiming at developing antimicrobial textiles for various application fields, particularly health applications and food-processing industry. The analytical approach combined different surface analysis techniques (microscopy techniques (SEM, AFM, TEM) and spectroscopy techniques (XPS, ToF-SIMS, SIMS, EELS)) to microbiological tests in order to understand the antimicrobial activity of deposits at the surface of textiles. Silver and Poly Hexamethylene Biguanide (PHMB) antimicrobial agents were deposited by plasma (PVD / PECVD) and padding, respectively. Specific constraints related to the application fields (hernia implants and clothing) were considered (minimum concentration in antimicrobial agent and resistance to industrial washing, respectively). Despite some ubiquitous contamination related to industrial processes, surface analysis techniques proved to be an essential help to develop these processes (deposit quality, influence of deposition conditions, influence of washing). Depending on the application fields, high sensitivity surface analysis at the extreme surface and in-depth distribution of the antimicrobial agent were essential to understand the antimicrobial properties of the deposits, which confirms the relevance of the multi-analytical approach used in this thesis work

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