L'équipe micro-capteurs de l'IM2NP développe des capteursde gaz dont le principe de détection est basé sur la mesure de la variationde la conductance en présence de gaz. Le matériau utilisé comme élémentsensible est l'oxyde de tungstène (WO3) en couches minces. L'objet de cettethèse est donc d'étudier la surface de WO3 dans sa reconstruction c(2x2),obtenue par clivage selon la direction [001]. Cette étude a été également suivied'une étude des lacunes par des calculs ab initio basés sur la DFT, dans lesdeux approximations LDA et GGA. Ensuite, l'dsorption de molécules de gazsimples (O3, COx, NOx) sur des surfaces plus ou moins riches en oxygènea été effectuée. Pour simuler ces systèmes, nous avons fait le choix du codeSIESTA basé sur la DFT et qui présente l'avantage de pouvoir travailler. / The team of micro sensors at IM2NP mainly focuses onthe development of gas sensors based on measurement in conductancevariation in presence of gas. The material used as sensitive element istungsten oxide (WO3) thin film. The objective of present thesis is to studythe surface properties of WO3 in its reconstruction c(2x2), obtained bycleavage along the [001] direction. This study is also followed by a gapanalysis using ab initio calculations based on DFT in both LDA andGGA approximations. Then, the adsorption of molecules of simple gases((O3, COx NOx) for these surfaces (more or less rich in oxygen), is performed.To simulate these systems, we have chosen the SIESTA code based onDFT which is used for the larger number of atoms as compared to other codes.

The object of this work is to obtain a fundamentalunderstanding of the principal issues concerning the handlingof an aqueous WC-Co powder suspension. The WO3 surface layer on the oxidised tungsten carbidepowder dissolves at pH&gt;3 with the tungsten concentrationincreasing linearly with time. Adding cobalt powder to thetungsten carbide suspension resulted in a significant reductionof the dissolution rate at pH&lt;10. Electrokinetic studiesindicated that the reduced dissolution rate may be related tothe formation of surface complexes; the experiments showed thatCo species in solution adsorb on the oxidised tungsten carbidepowder. The surface forces of oxidised tungsten and cobalt surfaceswere investigated using the atomic force microscope (AFM)colloidal probe technique. The interactions at various ionicstrengths and pH values are well described by DLVO theory. Theadsorption of cobalt ions to tungsten oxide surfaces resultedin an additional non-DLVO force and a reduced absolute value ofthe surface potential. It was shown that the adsorption ofpoly(ethylene imine) (PEI) to the WO3 surfaces induces anelectrosteric repulsion. The properties of spray-dried WC-Co granules were related tothe WC primary particle size, and the poly(ethylene glycol)(PEG) binder and PEI dispersant content in aqueous WC-Cosuspensions. The granule characterisation includes a new methodfor measuring the density of single granules. The increase inthe fracture strength of granules produced from suspensionsthat were stabilised with PEI was related to a more densepacking of the WC-Co particles. The AFM was used to study the friction and adhesion ofsingle spray-dried WC-Co granules containing various amounts ofPEG binder. The adhesion and friction force between two singlegranules (intergranular friction) and between a granule and ahard metal substrate (die-wall friction) have been determinedas a function of relative humidity. The granule-wall frictionincreases with binder content and relative humidity, whereasthe granule-granule friction is essentially independent of therelative humidity and substantially lower than the granule-wallfriction at all PEG contents. Key words:Hard Metal, Cemented Carbide, WC-Co, TungstenCarbide, Cobalt, Oxidation, Dissolution, Surface Complexation,XPS, AFM, Colloidal Probe, Hamaker Constant, Cauchy, WO3,CoOOH, ESCA, Zeta-Potential, Surface Potential, Poly(ethyleneimine), PEI, Suspension, van der Waals, Steric, Spray-Dried,Poly(ethylene glycol), Strength, Density, Friction, Adhesion,Granule, PEG, Pressing, FFM. / <p>QC 20161027</p>

In this work, we explored one material from the broad family of 2D semiconductors, namely WSe2 to serve as an enabler for advanced, low-power, high-performance nanoelectronics and optoelectronic devices. A 2D WSe2 based field-effect-transistor (FET) was designed and fabricated using electron-beam lithography, that revealed an ultra-high mobility of ~ 625 cm2/V-s, with tunable charge transport behavior in the WSe2 channel, making it a promising candidate for high speed Si-based complimentary-metal-oxide-semiconductor (CMOS) technology. Furthermore, optoelectronic properties in 2D WSe2 based photodetectors and 2D WSe2/2D MoS2 based p-n junction diodes were also analyzed, where the photoresponsivity R and external quantum efficiency were exceptional. The monolayer WSe2 based photodetector, fabricated with Al metal contacts, showed a high R ~502 AW-1 under white light illumination. The EQE was also found to vary from 2.74×101 % - 4.02×103 % within the 400 nm -1100 nm spectral range of the tunable laser source. The interfacial metal-2D WSe2 junction characteristics, which promotes the use of such devices for end-use optoelectronics and quantum scale systems, were also studied and the interfacial stated density Dit in Al/2D WSe2 junction was computed to be the lowest reported to date ~ 3.45×1012 cm-2 eV-1. We also examined the large exciton binding energy present in WSe2 through temperature-dependent Raman and photoluminescence spectroscopy, where localized exciton states perpetuated at 78 K that are gaining increasing attention for single photon emitters for quantum information processing. The exciton and phonon dynamics in 2D WSe2 were further analyzed to unveil other multi-body states besides localized excitons, such as trions whose population densities also evolved with temperature. The phonon lifetime, which is another interesting aspect of phonon dynamics, is calculated in 2D layered WSe2 using Raman spectroscopy for the first time and the influence of external stimuli such as temperature and laser power on the phonon behavior was also studied. Furthermore, we investigated the thermal properties in 2D WSe2 in a suspended architecture platform, and the thermal conductivity in suspended WSe2 was found to be ~ 1940 W/mK which was enhanced by ~ 4X when compared with substrate supported regions. We also studied the use of halide-assisted low-pressure chemical vapor deposition (CVD) with NaCl to help to reduce the growth temperature to ∼750 °C, which is lower than the typical temperatures needed with conventional CVD for realizing 1L WSe2. The synthesis of monolayer WSe2 with high crystalline and optical quality using a halide assisted CVD method was successfully demonstrated where the role of substrate was deemed to play an important role to control the optical quality of the as-grown 2D WSe2. For example, the crystalline, optical and optoelectronics quality in CVD-grown monolayer WSe2 found to improve when sapphire was used as the substrate. Our work provides fundamental insights into the electronic, optoelectronic and quantum properties of WSe2 to pave the way for high-performance electronic, optoelectronic, and quantum-optoelectronic devices using scalable synthesis routes.

O objetivo deste trabalho foi avaliar o efeito da soldagem TIG (\"tungsten inert gas\") e compará-la com soldagem a laser, em hastes cilíndricas e supra-estruturas implantosuportadas, confeccionadas em titânio comercialmente puro (Ti cp) por meio dos ensaios de resistência mecânica (tração e flexão) e desajuste marginal, respectivamente. Foram confeccionados noventa corpos-de-prova em titânio cp, sendo sessenta, na forma de hastes cilíndricas, obtidas por fundição de hastes de latão, e trinta na forma de supra-estruturas implanto-suportadas, obtidas por modelo de gesso com quatro análogos de implantes Microunit (Conexão), com dez repetições para cada grupo (controle, solda TIG, solda a Laser). Para a obtenção dos corpos-de-prova, foi realizada inclusão em revestimento Rematitan Plus, de acordo com as instruções fabricante. Os anéis foram submetidos aos ciclos térmicos e posicionados na máquina de fundição (Rematitan), sob arco voltaico, vácuo e atmosfera de argônio, com injeção de titânio sob vácuo-pressão. Após resfriamento, as fundições foram desincluídas e jateadas com óxido de alumínio. Os corpos-de-prova obtidos em forma de hastes cilíndricas foram distribuídos aleatoriamente, em três grupos, para ambos os ensaios, resistência à tração e flexão: grupo controle (sem solda), solda TIG e solda a Laser. As trinta supra-estruturas foram divididas aleatoriamente em três grupos: I- controle - monobloco; II-B- pós-soldagem TIG e III-B- pós-soldagem a Laser; os grupos II-A e III-A, foram constituídos dos espécimes antes do processo de soldagem: II-A- pré-soldagem TIG e III-A- pré-soldagem a Laser. Os dados obtidos para o Ensaio de Tração (MPa) foram analisados estatisticamente pelos testes ANOVA e Tukey (&alpha;= 0,05). O teste complementar de Tukey (p = 0,05) evidenciou que houve diferença entre o grupo controle (605,84 ± 19,83) e os métodos de soldagem TIG (514,90 ± 37,76) e Laser (515,85 ± 62,07). Para o Ensaio de Flexão (MPa), o teste não-paramétrico de Kruskal-Wallis mostrou que não houve diferença estatisticamente significante entre os processos de soldagem TIG (1559,66) e Laser (1621,64), contudo a diferença foi significante entre estes grupos e o controle (1908,75). Para análise dos resultados do desajuste marginal (&mu;m) das supra-estruturas implanto-suportadas, o teste nãoparamétrico de Kruskal-Wallis revelou que não houve diferença estatisticamente significante entre os grupos pós-soldagem TIG (250) e pós-soldagem Laser (241), entretanto, o grupo controle (770) apresentou o maior desajuste. Pelos resultados obtidos e dentro das limitações deste estudo, pode-se afirmar que a soldagem a TIG propicia a obtenção de resultados similares à soldagem a Laser. / The aim of this study was to evaluate the effect of TIG welding (tungsten inert gas) and compare it with Laser welding, of the cylindrical rods and implant-supported frameworks, obtained by in commercially pure titanium (cp) through the mechanical resistance (tensile and flexural strength) and misfit marginal, respectively. Ninety specimens have been fabricated titanium cp, and sixty, cylindrical rods, obtained by casting of the brass rods, and thirty implant-supported frameworks, obtained by plaster die with four similar - Microunit implants (Connection), with ten repetitions for each group (control, TIG welding, laser welding). The specimens were invested in Rematitan Plus, according to the manufacturer instructions. The rings were subjected to thermal cycling and positioned in the machine of casting (Rematitan) under voltaic arc, vacuum and atmosphere of argon, with injection of titanium vacuumpressure. After cooling, were manually and airbone-particle abraded with aluminum oxide. The specimes cylindrical rods were randomly distributed in three groups, for tests, tensile and flexural strength: the control group (without welding), TIG welding and soldering laser. The above thirty-structures were randomly divided into three groups: I- one-piece-cast (control)-, II-B-after-TIG welding and III-B-after-Laser welding, the Group II-A, III-A, consisted of specimens before the process of welding: II-A-before-TIG welding and III-A before-Laser welding. The results for the test Traction were submitted to variance analysis ANOVA (p < 0.05) being observed difference between groups. The supplementary Tukey test (p = 0.05) showed that there was a difference between the control group (605.84 ± 19.83) and the methods of welding TIG (514.90 ± 37.76) and laser (515.85 ± 62.07). To test the Flexion nonparametric test Kruskal-Wallis showed that there was no statistically significant difference between the processes of TIG welding (1559.66) and Laser (1621.64), but the difference was significant between these groups and control (1908.75). For analysis of the results of marginal misfit implant-supported frameworks, the non-parametric Kruskal-Wallis test revealed that there was no statistically significant difference between groups after-TIG welding (250) and after- Laser welding (241), however, the control group (770) showed the largest misfit. With these and the limitations of this study TIG welding in may be to Laser welding.

A ausência de adaptação passiva em prótese sobre implantes pode sobrecarregar implantes, componentes protéticos e tecido ósseo, levando à perda óssea marginal e até da osseointegração. A soldagem é utilizada com frequência para melhorar o assentamento de estruturas metálicas de próteses em geral e de próteses sobre implantes. Além disso, a precisão no assentamento da peça protética pode estar relacionada com os cuidados na técnica de confecção da mesma. Assim, o objetivo deste trabalho foi avaliar, por meio de microscopia óptica e confocal a laser, a adaptação marginal de barras metálicas tipo protocolo de Branemark, de ligas de niquel-cromo (NiCr) em monobloco e soldadas, confeccionadas a partir de enceramento convencional. Para isso, foi confeccionado um modelo mestre, simulando quatro implantes sobre o qual foram adaptados transferentes e análogos que serviram para transferir a posição dos implantes para o modelo de gesso. Os enceramentos obtidos pelo método convencional foram fundidos em monobloco e em partes separadas (seccionados), sendo os últimos, posteriormente soldados utilizando as técnicas convencional a maçarico e TIG (Tungsten Inert Gas). As leituras da adaptação da barra em cada implante foram feitas nas peças em monobloco (n=5) e nas peças seccionadas (n=10), antes e após as diferentes técnicas de soldagem. Pelo método de medição de microscopia óptica, foram realizadas as medições em duas regiões pré-determinadas ( Vestibular e Lingual ), com três repetições, totalizando 6 leituras por implante. Já no método de microscopia Confocal a laser, foi realizada somente na Vestibular. Para comparar os dados obtidos quanto ao desajuste marginal entre componente protético/implante, considerando-se as peças em monobloco, as peças soldadas, as técnicas de soldagem (maçarico e TIG), os métodos de medição e a posição dos implantes, foram realizados testes estatísticos, onde para cada uma das análises realizadas foi determinada a aplicação do Teste de Normalidade (Shapiro-Wilk ou Kolmogorov-Smirnov (alfa = 5%)) para determinação da distribuição da amostra. Para a amostra com distribuição normal foi determinada a utilização do teste paramétrico, Análise de Variância, enquanto que a amostra com distribuição não normal, determinou-se a utilização do teste não paramétrico de Kruskal Wallis. Os resultados encontrados foram estatisticamente significantes para comparação método e técnica, sugerindo que as peças em monobloco apresentaram maior desadaptação que as peças soldadas, e que as peças soldadas pela técnica convencional não apresentaram diferença estatística, em relação as soldadas pela técnica TIG. Em relação a comparação dos métodos de medição, houve diferença estaticamente significante, onde a microscopia Confocal a laser obteve os maiores valores de desadaptação. A interação técnica e método não houve diferenças estatísticas. Na comparação de diferentes secções e soldada, para os 2 métodos de medição, em relação ao fator Secção, não houve diferença significante onde 3 secções apresentam os menores resultados e as soldadas tiveram igualdade em relação a 1 secção. Pelo fator Técnica houve diferença estatisticamente significante, onde a técnica convencional obteve as maiores médias. A interação Secção e Técnica, não teve efeito significante. A adaptação marginal da peça em relação a posição do implante na arcada, não houve diferença estatística, para ambos os métodos. Houve diferença apenas no fator Técnica, pela microscopia óptica, onde a Monobloco teve os maiores resultados e a Solda Convencional e TIG, tiveram igualdade nos resultados. A investigação de sistemas de confecção de estruturas da prótese e de técnicas de soldagem é importante na busca pela produção de próteses sobre dente ou sobre implante com precisão no ajuste marginal que possa ser comprovado visual e numericamente utilizando-se recursos tecnológicos que assegurem a utilização clínica das peças protéticas. / The lack of passive adaptation in prosthesis over implant can overload implants, prosthetics components and bone tissue, leading to marginal bone loss and even osseointegration. Weldering is used frequently to improve the settlement of metal structures of prosthetic in general and prosthesis over implants. In addition, the settlement precision of the workpiece may be related to the care in the technique of manufacturing the same. The objective of this study was to evaluate, through optical and confocal Laser microscopy, the marginal adaptation of metal bars Branemark protocol type alloy nickel-chromium (NiCr) monoblock and welded, made from conventional waxing .For this, a master model was made to simulate four implants were adapted over which transferents and analogs that served to transfer the position of the implants for the cast model. Waxing obtained by the conventional method were cast in one-piece and separate parts (sectioned), the latter being subsequently welded using the conventional techniques blowtorch and TIG (Tungsten Inert Gas).The bar adjustment of readings in each implant were made in monoblock pieces (n = 5) and the severed pieces (n = 10) before and after different weldering techniques. By optical microscopy measurement method, measurements were performed in two predetermined regions (Vestibular and lingual), with three replications, totaling 6 readings per implant. However in the methodology of Confocal laser microscope, was done only on Vestibular. To compare the data obtained on the misfit between prosthetic/implant component, considering the pieces monoblock, the welded parts, the weldering techniques (torch and TIG), measurement methods and the position of the implants, tests were performed statistical where for each of the analyzes determined the application of Normality Test (Shapiro-Wilk test and Kolmogorov-Smirnov test (alpha = 5%)) to determine the distribution of the sample. For the sample of normal distribution was determined using the parametric test, analysis of variance, while the sample with non-normal distribution was determined using the nonparametric Kruskal-Wallis test. The results found were statistically significant for method and technique comparison, suggesting that the monoblock parts showed higher misfit than welded parts, and the parts welded by conventional technique showed no statistical difference in relation welded by TIG technique. Regarding the comparison of measurement methods, there was no statistically significant difference, where the Laser Confocal microscopy obtained the greatest misfit. The technical interaction and method there were no statistical differences. When comparing different sections and welded to the two measurement methods, in relation to Section factor, there was no significant difference where 3 sections have the lowest results and welded had equality with 1 section. The technical factor was no statistically significant difference, the conventional technique had the highest averages. The interaction and Technical Section had no significant effect. The marginal adaptation of the play in relation to the implant in the arch position, there was no statistical difference for both methods. There was a difference only in the technical factor, by optical microscopy, where Monoblock had the greatest results and Conventional Welding and TIG, had equality in results. The research of making the prosthesis structures systems and weldering techniques is important in the search for production of prosthetic tooth or on precisely implant the marginal adjustment that can be verified visually and numerically using technological resources to ensure clinical use of prosthetic pieces.

O objetivo deste trabalho foi avaliar o efeito da soldagem TIG (\"tungsten inert gas\") e compará-la com soldagem a laser, em hastes cilíndricas e supra-estruturas implantosuportadas, confeccionadas em titânio comercialmente puro (Ti cp) por meio dos ensaios de resistência mecânica (tração e flexão) e desajuste marginal, respectivamente. Foram confeccionados noventa corpos-de-prova em titânio cp, sendo sessenta, na forma de hastes cilíndricas, obtidas por fundição de hastes de latão, e trinta na forma de supra-estruturas implanto-suportadas, obtidas por modelo de gesso com quatro análogos de implantes Microunit (Conexão), com dez repetições para cada grupo (controle, solda TIG, solda a Laser). Para a obtenção dos corpos-de-prova, foi realizada inclusão em revestimento Rematitan Plus, de acordo com as instruções fabricante. Os anéis foram submetidos aos ciclos térmicos e posicionados na máquina de fundição (Rematitan), sob arco voltaico, vácuo e atmosfera de argônio, com injeção de titânio sob vácuo-pressão. Após resfriamento, as fundições foram desincluídas e jateadas com óxido de alumínio. Os corpos-de-prova obtidos em forma de hastes cilíndricas foram distribuídos aleatoriamente, em três grupos, para ambos os ensaios, resistência à tração e flexão: grupo controle (sem solda), solda TIG e solda a Laser. As trinta supra-estruturas foram divididas aleatoriamente em três grupos: I- controle - monobloco; II-B- pós-soldagem TIG e III-B- pós-soldagem a Laser; os grupos II-A e III-A, foram constituídos dos espécimes antes do processo de soldagem: II-A- pré-soldagem TIG e III-A- pré-soldagem a Laser. Os dados obtidos para o Ensaio de Tração (MPa) foram analisados estatisticamente pelos testes ANOVA e Tukey (&alpha;= 0,05). O teste complementar de Tukey (p = 0,05) evidenciou que houve diferença entre o grupo controle (605,84 ± 19,83) e os métodos de soldagem TIG (514,90 ± 37,76) e Laser (515,85 ± 62,07). Para o Ensaio de Flexão (MPa), o teste não-paramétrico de Kruskal-Wallis mostrou que não houve diferença estatisticamente significante entre os processos de soldagem TIG (1559,66) e Laser (1621,64), contudo a diferença foi significante entre estes grupos e o controle (1908,75). Para análise dos resultados do desajuste marginal (&mu;m) das supra-estruturas implanto-suportadas, o teste nãoparamétrico de Kruskal-Wallis revelou que não houve diferença estatisticamente significante entre os grupos pós-soldagem TIG (250) e pós-soldagem Laser (241), entretanto, o grupo controle (770) apresentou o maior desajuste. Pelos resultados obtidos e dentro das limitações deste estudo, pode-se afirmar que a soldagem a TIG propicia a obtenção de resultados similares à soldagem a Laser. / The aim of this study was to evaluate the effect of TIG welding (tungsten inert gas) and compare it with Laser welding, of the cylindrical rods and implant-supported frameworks, obtained by in commercially pure titanium (cp) through the mechanical resistance (tensile and flexural strength) and misfit marginal, respectively. Ninety specimens have been fabricated titanium cp, and sixty, cylindrical rods, obtained by casting of the brass rods, and thirty implant-supported frameworks, obtained by plaster die with four similar - Microunit implants (Connection), with ten repetitions for each group (control, TIG welding, laser welding). The specimens were invested in Rematitan Plus, according to the manufacturer instructions. The rings were subjected to thermal cycling and positioned in the machine of casting (Rematitan) under voltaic arc, vacuum and atmosphere of argon, with injection of titanium vacuumpressure. After cooling, were manually and airbone-particle abraded with aluminum oxide. The specimes cylindrical rods were randomly distributed in three groups, for tests, tensile and flexural strength: the control group (without welding), TIG welding and soldering laser. The above thirty-structures were randomly divided into three groups: I- one-piece-cast (control)-, II-B-after-TIG welding and III-B-after-Laser welding, the Group II-A, III-A, consisted of specimens before the process of welding: II-A-before-TIG welding and III-A before-Laser welding. The results for the test Traction were submitted to variance analysis ANOVA (p < 0.05) being observed difference between groups. The supplementary Tukey test (p = 0.05) showed that there was a difference between the control group (605.84 ± 19.83) and the methods of welding TIG (514.90 ± 37.76) and laser (515.85 ± 62.07). To test the Flexion nonparametric test Kruskal-Wallis showed that there was no statistically significant difference between the processes of TIG welding (1559.66) and Laser (1621.64), but the difference was significant between these groups and control (1908.75). For analysis of the results of marginal misfit implant-supported frameworks, the non-parametric Kruskal-Wallis test revealed that there was no statistically significant difference between groups after-TIG welding (250) and after- Laser welding (241), however, the control group (770) showed the largest misfit. With these and the limitations of this study TIG welding in may be to Laser welding.

A ausência de adaptação passiva em prótese sobre implantes pode sobrecarregar implantes, componentes protéticos e tecido ósseo, levando à perda óssea marginal e até da osseointegração. A soldagem é utilizada com frequência para melhorar o assentamento de estruturas metálicas de próteses em geral e de próteses sobre implantes. Além disso, a precisão no assentamento da peça protética pode estar relacionada com os cuidados na técnica de confecção da mesma. Assim, o objetivo deste trabalho foi avaliar, por meio de microscopia óptica e confocal a laser, a adaptação marginal de barras metálicas tipo protocolo de Branemark, de ligas de niquel-cromo (NiCr) em monobloco e soldadas, confeccionadas a partir de enceramento convencional. Para isso, foi confeccionado um modelo mestre, simulando quatro implantes sobre o qual foram adaptados transferentes e análogos que serviram para transferir a posição dos implantes para o modelo de gesso. Os enceramentos obtidos pelo método convencional foram fundidos em monobloco e em partes separadas (seccionados), sendo os últimos, posteriormente soldados utilizando as técnicas convencional a maçarico e TIG (Tungsten Inert Gas). As leituras da adaptação da barra em cada implante foram feitas nas peças em monobloco (n=5) e nas peças seccionadas (n=10), antes e após as diferentes técnicas de soldagem. Pelo método de medição de microscopia óptica, foram realizadas as medições em duas regiões pré-determinadas ( Vestibular e Lingual ), com três repetições, totalizando 6 leituras por implante. Já no método de microscopia Confocal a laser, foi realizada somente na Vestibular. Para comparar os dados obtidos quanto ao desajuste marginal entre componente protético/implante, considerando-se as peças em monobloco, as peças soldadas, as técnicas de soldagem (maçarico e TIG), os métodos de medição e a posição dos implantes, foram realizados testes estatísticos, onde para cada uma das análises realizadas foi determinada a aplicação do Teste de Normalidade (Shapiro-Wilk ou Kolmogorov-Smirnov (alfa = 5%)) para determinação da distribuição da amostra. Para a amostra com distribuição normal foi determinada a utilização do teste paramétrico, Análise de Variância, enquanto que a amostra com distribuição não normal, determinou-se a utilização do teste não paramétrico de Kruskal Wallis. Os resultados encontrados foram estatisticamente significantes para comparação método e técnica, sugerindo que as peças em monobloco apresentaram maior desadaptação que as peças soldadas, e que as peças soldadas pela técnica convencional não apresentaram diferença estatística, em relação as soldadas pela técnica TIG. Em relação a comparação dos métodos de medição, houve diferença estaticamente significante, onde a microscopia Confocal a laser obteve os maiores valores de desadaptação. A interação técnica e método não houve diferenças estatísticas. Na comparação de diferentes secções e soldada, para os 2 métodos de medição, em relação ao fator Secção, não houve diferença significante onde 3 secções apresentam os menores resultados e as soldadas tiveram igualdade em relação a 1 secção. Pelo fator Técnica houve diferença estatisticamente significante, onde a técnica convencional obteve as maiores médias. A interação Secção e Técnica, não teve efeito significante. A adaptação marginal da peça em relação a posição do implante na arcada, não houve diferença estatística, para ambos os métodos. Houve diferença apenas no fator Técnica, pela microscopia óptica, onde a Monobloco teve os maiores resultados e a Solda Convencional e TIG, tiveram igualdade nos resultados. A investigação de sistemas de confecção de estruturas da prótese e de técnicas de soldagem é importante na busca pela produção de próteses sobre dente ou sobre implante com precisão no ajuste marginal que possa ser comprovado visual e numericamente utilizando-se recursos tecnológicos que assegurem a utilização clínica das peças protéticas. / The lack of passive adaptation in prosthesis over implant can overload implants, prosthetics components and bone tissue, leading to marginal bone loss and even osseointegration. Weldering is used frequently to improve the settlement of metal structures of prosthetic in general and prosthesis over implants. In addition, the settlement precision of the workpiece may be related to the care in the technique of manufacturing the same. The objective of this study was to evaluate, through optical and confocal Laser microscopy, the marginal adaptation of metal bars Branemark protocol type alloy nickel-chromium (NiCr) monoblock and welded, made from conventional waxing .For this, a master model was made to simulate four implants were adapted over which transferents and analogs that served to transfer the position of the implants for the cast model. Waxing obtained by the conventional method were cast in one-piece and separate parts (sectioned), the latter being subsequently welded using the conventional techniques blowtorch and TIG (Tungsten Inert Gas).The bar adjustment of readings in each implant were made in monoblock pieces (n = 5) and the severed pieces (n = 10) before and after different weldering techniques. By optical microscopy measurement method, measurements were performed in two predetermined regions (Vestibular and lingual), with three replications, totaling 6 readings per implant. However in the methodology of Confocal laser microscope, was done only on Vestibular. To compare the data obtained on the misfit between prosthetic/implant component, considering the pieces monoblock, the welded parts, the weldering techniques (torch and TIG), measurement methods and the position of the implants, tests were performed statistical where for each of the analyzes determined the application of Normality Test (Shapiro-Wilk test and Kolmogorov-Smirnov test (alpha = 5%)) to determine the distribution of the sample. For the sample of normal distribution was determined using the parametric test, analysis of variance, while the sample with non-normal distribution was determined using the nonparametric Kruskal-Wallis test. The results found were statistically significant for method and technique comparison, suggesting that the monoblock parts showed higher misfit than welded parts, and the parts welded by conventional technique showed no statistical difference in relation welded by TIG technique. Regarding the comparison of measurement methods, there was no statistically significant difference, where the Laser Confocal microscopy obtained the greatest misfit. The technical interaction and method there were no statistical differences. When comparing different sections and welded to the two measurement methods, in relation to Section factor, there was no significant difference where 3 sections have the lowest results and welded had equality with 1 section. The technical factor was no statistically significant difference, the conventional technique had the highest averages. The interaction and Technical Section had no significant effect. The marginal adaptation of the play in relation to the implant in the arch position, there was no statistical difference for both methods. There was a difference only in the technical factor, by optical microscopy, where Monoblock had the greatest results and Conventional Welding and TIG, had equality in results. The research of making the prosthesis structures systems and weldering techniques is important in the search for production of prosthetic tooth or on precisely implant the marginal adjustment that can be verified visually and numerically using technological resources to ensure clinical use of prosthetic pieces.

Les dispositifs électrochromes sont des dispositifs qui permettent de moduler la réflexion ou la transmission de la lumière. Ils recouvrent une grande variété d’applications dans le domaine du visible (vitrages intelligents) et dans le domaine de l’infrarouge (protection thermique des satellites et discrétion optique infrarouge). Les travaux présentés dans ce manuscrit répondent essentiellement à une problématique visant à élaborer un dispositif électrochrome tout solide à émissivité infrarouge variable par un procédé unique de pulvérisation cathodique magnétron. Une nouvelle architecture d’empilement avec une électrode de travail monocouche bi fonctionnelle a été choisie pour réunir les propriétés apportées classiquement par deux couches ou plus sur le haut des empilements électrochromes. Cette nouvelle architecture a nécessité la mise en place d’un procédé de dépôt original de pulvérisation cathodique réactive hydratée. Ce procédé a permis d’obtenir une électrode monocouche à base de trioxyde de tungstène réunissant les propriétés optiques et électroniques souhaitées. Il a également permis de déposer les autres couches de l’empilement, la contre-électrode à base de trioxyde de tungstène et les électrolytes solides conducteurs protoniques à base d’oxyde de tantale ou de zirconium. L’étude de l’ajout d’une couche d’encapsulation à base de dioxyde de cérium a également été menée. Cette architecture a permis d’obtenir un empilement électrochrome tout solide fonctionnel. Ce dispositif complet ainsi élaboré présente de bonnes propriétés optiques dans l’infrarouge en terme de modulation d’émissivité dans les bandes spectrales d’intérêt, à savoir 13 % en bande II et 31 % en bande III. / Electrochromic materials are devices for modulating the reflection or transmission of light. They cover a wide variety of applications in the visible range (smart windows) and the infrared range (thermal protection for satellites and optical infrared discretion). The works presented in this manuscript were essentially responding to the problem of developping an all solid electrochromic device with a variable infrared emissivity by a single process of magnetron sputtering. A new stacking architecture with a working bi functional monolayer electrode was chosen to bring the properties conventionally made by two or more layers on top of electrochromic device. This new architecture has required the establishment of an original deposit process of hydrated reactive sputtering. This process yielded a monolayer electrode based on tungsten trioxide combining the desired optical and electronic properties. It allowed to deposit other layers of the stack, the counter electrode based on tungsten trioxide and the proton conductive solid electrolyte based on tantalum or zirconium oxide. The study of the addition of an encapsulation layer based on cerium dioxide was also conducted. This architecture has resulted in a functional all-solid electrochromic stack. The complete device thus prepared exhibits good optical properties in the infrared emissivity in terms of modulation and in particular in the spectral bands of interest, namely 13 % in MW and 31 % in LW.

Des recherches très importantes ont été dédiées à l'étude des composés ferroélectriques de type bronze de tungstène quadratique (TTB). Cette thèse concerne la synthèse et la caractérisation de 7 matériaux TTB de formule générale A6M2M'8O30 (A = Sr2+, Ba2+ ou Pb2+, M = Ti4+, Zr4+ ou HF4+; M' = Nb5+ ou Ta5+). Ces composés cristallins de grande taille ∼100 nm ont été synthétisés sous forme de poudre. Les moyennes expérimentales : diffractions des rayons X, spectroscopie Raman, la microscopie électronique MEB et MET, l'optique non linéaire ONL, ont permis d'établir des relations étroites entre structure et propriétés physiques. Les susceptibilités optiques non linéaires de 2eme et 3eme ordres, χ(2), χ(3) de chaque composés ont été déterminées et les valeurs résultantes du χ(3) ne montrent pas les mêmes caractéristiques que χ(2), car le signal de THG est moins dépendant de structure que SHG qui requiert un milieu non-centrosymétrique. Le décalage fréquentiel (Δσ) des modes de vibrations entre les structures à base de strontium(Sr) et celles à base de Barium(Ba) a été constaté afin d'identifier les signatures propres de ces composés. L'interprétation de ces poudres n'était pas facile car les pics sont très délicats. Nos mesures expérimentales montrent clairement que les positions des pics peuvent être modifiées par le changement cationique au sein des matériaux, plus la maille cristalline est rigide, plus on a des pics plus discernables. La différence est nettement visible là ou l'émission est autour de 808 cm-1 pour la structure (Sr), alors que pour le (Br) elle est autour de 780cm-1. Nous attribuons ce Δσ (28cm-1) à la transition de groupe de symétrie spatiale de Pba2 vers P4bm. L'ensemble des résultats décrits dans ce travail ont montrés la grande variété des paramètres sur lesquels il est possible d'agir afin d'optimiser les compositions en vue d'une application spécifique. / Recently, very significant research has been devoted to the study of ferroelectric compounds of tetragonal tungsten bronze (TTB). This thesis deals with the synthesis and characterization of 7 TTB's material with general formula A6M2M'8O30 (A = Sr2+, Ba2+ or Pb2+, M = Ti4+, Zr4+ or HF4+, M '= Nb5+ or Ta5+). These crystalline compounds of large size ~ 100 nm were synthesized in powder form. The experimental Technics: X-ray diffraction, Raman spectroscopy, scanning electron microscopy SEM and TEM and nonlinear optics NLO, allowed us to establish close relationships between structure and physical properties. The nonlinear 2nd and 3rd order optical susceptibility χ(2), χ(3) of all compounds were determined and the resulting values of χ(3) did not show the same characteristics as measures of χ(2) because the THG signal is less dependent on the structure where SHG signal requires a non-centro-symmetric medium. The frequency shift between the vibration modes of structures containing strontium (Sr) and those based on Barium (Ba) has been detailed to identify signatures of these specific compounds. The interpretation of these powders wasn't that easy as these peaks are very delicate but our experimental results clearly show that the positions of the peaks can be modified by the change in cation materials, as long as the crystal lattice is more rigid, more we get discernible Raman modes. This difference is clearly visible where the emission is around 808 cm-1 for the structure Sr, whereas the Br it is centered around 780cm-1. We attribute these Δσ (28cm-1) to the transition of spatial symmetry group from Pba2 to P4bm. Results showed the wide variety of settings in which it is possible to act in order to optimize the compositions for a specific application.

Les processus élémentaires hétérogènes à l’interface gaz-solide présentent un intérêt fondamental dans de nombreux domaines tels que la catalyse hétérogène, la chimie atmosphérique et des milieux interstellaires, la rentrée atmosphérique de véhicules spatiaux ou encore la description des interactions plama-paroi. Cette thèse a pour objet l’étude de la dynamique des processus de collision non réactive de l’azote N2 sur une surface de tungstène W(100) et des processus de recombinaison moléculaire de l’hydrogène H2 sur des surfaces de tungstène W(100) et W(110). Leur dynamique quasi classique est simulée au moyen de surfaces d’énergie potentielle préalablement construites à partir de calculs de théorie de la fonctionnelle de la densité. Un potentiel multi-adsorbats est notamment développé pour tenir compte du taux de couverture de surface afin d’étudier la compétition entre la recombinaison directe, de type Eley-Rideal et la recombinaison par « atomes chauds » après diffusion hyperthermique d’un atome sur la surface. / Heterogeneous elementary processes at the gas-solid interface are ofgreat interest in many domains such as heterogeneous catalysis, atmospheric and interstellar media chemistry, spacecraft atmospheric re-entry and plasma-wall interactions description. This thesis focus on the dynamics of nitrogen, N2, non reactive scattering on a tungsten W(100) surface and hydrogen, H2, recombination processes on tungsten surfaces W(100) and W(110). The quasiclassical dynamics of these processes is simulated using potential energy surfaces based on density functional theory calculations. In particular, a multi-adsorbate potential is developed to include surface coverage in the dynamics simulation in order to scrutinize the interplay between both direct abstraction, the so-called Eley-Rideal recombination,and the Hot-Atom recombination process after hyperthermal diffusion on the surface