Traditionally archaeology has referred to the anthropic sediments accumulated around prehistoric settlements with the blanket term ‘midden’. This is now recognised as an inadequate term to describe the complex formation processes and functions represented in these sediments. This thesis reviewed the body of evidence accumulated over the past century of research into Neolithic and Bronze Age settlements on the islands of the Scottish North Atlantic seaboard and extrapolated the many occurrences of ‘midden’. Several contexts emerged for these sediments including interior floors, hearths, exterior occupational surfaces, dumped deposits, building construction materials and abandonment infill. In addition, ‘midden’ is described added to cultivated soils to form fertile anthrosols. The way in which prehistoric communities exploited this material for agriculture and construction has been described through geoarchaeological research which implied that to past communities ‘midden’ was a valuable resource. This led to the formation of a model based upon a human ecodynamics framework to hypothesise sediment formation pathways. Rescue excavation at the Links of Noltland, Westray provided an opportunity to conduct a holistic landscape and fine resolution based study of Neolithic and Bronze Age settlement to test this model. The research incorporated auger survey, archaeological and geoarchaeological excavation, thin section micromorphology and SEM EDX analyses. Sediments identified in literature review and recovered from the field site were described using this toolkit and set within a cultural and environmental context. Results demonstrate that anthropic materials were incorporated into all contexts examined. Discrete burning and maintenance activities were found to have taken place during the gradual accumulation of open-air anthropic sediments whilst incorporation of fuel residues and hearth waste into floors lead to the gradual formation of ‘living floors’ inside structures. An unexpected discovery was evidence of animal penning within late Neolithic/Early Bronze Age settlement and the in situ burning of stabling waste. Three types iv | P a g e of land management strategy which relied upon the input of anthropic sediments were evidenced and the range and extent of anthropic inclusions in the landscape recorded. Spatial interpolation of auger survey data utilised a new sub-surface modelling technique being developed by the British Geological Survey to explore soil stratigraphic relationships in 3D. SEM EDX analysis supported micromorphological analysis providing chemical data for discrete inclusions and assisting in the identification of herbivore dun ash and the Orcadian funerary product ‘cramp’. SEM EDX analysis was also applied to fine organo-mineral material for statistical testing of nutrient loadings across context groups. It was found that anthropic sediments were enriched in macro and intermediate plant nutrients Mg, P, K, S and Ca compared to geological controls, and the application of anthropic material to cultivated soils improved soil fertility for the three observed land management practices. The versatility of anthropic sediments was explored through discussion of context groups based upon the results of this research and the potential significance of this material to prehistoric communities is explored.

Avec près de 25 000 cas en 2015, le cancer du sein est de loin le cancer le plus fréquent chez les femmes canadiennes. En termes de mortalité, le cancer du sein se place au deuxième rang (13,8%), derrière le cancer du poumon (26,5%). Suite au diagnostic, 70% des femmes avec un cancer de stade avancé et 30% des femmes avec cancer précoce choisiront de subir une mastectomie totale. Plusieurs options de reconstructions mammaires sont ensuite offertes. Plus de 70% des reconstructions se feront par la mise en place d’implants mammaires (plutôt que par reconstruction autologue utilisant les tissus de la patiente). Parmi les complications survenant après cette intervention, la contracture capsulaire en est une des plus fréquente. La contracture capsulaire se définit comme la contraction anormale de la capsule fibreuse se formant autour des implants mammaires, pouvant causer des douleurs en plus d’un mauvais résultat sur le plan esthétique. Les études cliniques ont démontré un risque accru de développer une contracture capsulaire chez les femmes ayant du suivre un protocole de radiothérapie. Si plusieurs études ont cherché à démontré l’influence des radiations sur l’histologie et l’immunologie du tissu capsulaire, aucune étude ne s’était intéressée à leur effet sur l’ultrastructure capsulaire. Notre équipe a récemment démontré que l’ultrastructure capsulaire dépendait de plusieurs facteurs, notamment de la texture prothétique et du délai de reconstruction. L’objectif de ce mémoire était de décrire l’impact de la radiothérapie sur l’ultrastructure capsulaire en comparant des capsules irradiées et non-irradiées en utilisant la microscopie éléctronique à balayage. Nous avons observé, chez les échantillons issus de capsules irradiés, une perte de relief au niveau de l’interface prothèse-capsule par rapport au échantillons non irradiés. Nous avons aussi démontré que cette caractéristique ultrastructurale est associée à la présence de contracture capsulaire. Enfin, ces effets néfastes de la radiothérapie semblent altérer la capacité de la capsule à adhérer à la prothèse mammaire. En conclusion, mon projet de maîtrise aura permis de décrire pour la première fois l’impact de la radiothérapie sur l’ultrastructure des capsules périprothétiques. Bien que nos résultats ne nous permettent pas d’expliquer de façon certaine le lien potentiel avec l’évolution vers un état de contracture capsulaire, ils laissent croire que cela serait associé avec un diminution de la stabilité de la capsule sur son implant, facteur auparavant évoqué comme ayant une rôle protecteur sur la contracture capsulaire. / With around 25,000 cases in 2015, breast cancer is the most common cancer among Canadian women. In term of mortality, breast cancer is second (13.8%), only behind lung cancer (26.5%). As part of the therapeutic approaches, around 70% and 30% of women with advanced and early breast cancer (respectively) will chose to have a total mastectomy. Following a mastectomy, few options of breast reconstruction are offered to the patients. More than 70% of breast reconstructions are implant-based. Among the complications following this surgery, capsular contracture (CC) is one of the most common. CC is defined as the abnormal, and sometimes painful, contraction of the fibrous capsule that normally grows aroung breast implants, resulting in a aesthetic failure and associated with a higher surgical revision rate. Many studies have demonstrated that the incidence of CC was higher among women who had undergone radiotherapy prior to their implant-based breast breast reconstruction procedure. Most of published studies focus on the influence of radiotherapy on capsular tissue at the immune-histological level but no study has described its influence on capsular architecture. As our team recently demonstrated that capsular ultrastructure is influenced by many factors (prosthetic texture, expansion timing). The main purpose was to describe the impact of radiotherapy on periprosthetic capsule ultrastructural features by comparing irradiated and non-irradiated capsules using scanning electron microscopy (SEM). We observed a significant loss of tridimensional texture at the implant-capsule interface in irradiated capsular samples. This feature was also found to be associated with CC. Finally, our results tend to show that radiotherapy impaires the stability of capsules by preventing them to grow withing their surrounding implant texure. In conclusion, the present research project offers the first description of the capsular response following exposiong to radiations. Even though our results do not allow us to conlude to a clear relation between loss of capsular architecture and a higher risk of CC, we think that the impairement of capsular stability might be part of the answer

Biofilm formation is one of the most common bacterial survival strategies. Majority of bacterial species are able to form these three-dimensional structures, including pathogens like Mycobacterium tuberculosis. Representatives of Mycobacterium genus widely occur in the nature, although they can cause serious problems when they appear in medical equipment and artificial replacements of the human body. Non-pathogenic Mycobacterium smegmatis mc2 155 was used as a model organism in our experiments. We investigated morphology of the three- and six-day-old colonies (in fact biofilms) on agar and agar covered with cellophane using Stereo microscope and Scanning Electron Microscope. We found that a type of surface as well as a carbon source has a great influence on the morphology of the M. smegmatis colonies. We isolated proteomes from the agar and cellophane cultures and from planktonic culture. Two-dimensional electrophoresis was used as the main proteomic method. Proteomic data were analyzed using PDQuest software. Then the sets of proteins detected by qualitative and quantitative analyses were compared using Venn diagrams. As a result, we recognized 7 unique proteins that might be specific for recognition and adhesion of bacteria to the cellophane, no unique protein in agar proteome and 46 unique...

Dentre as opções de terapias dessensibilizantes, a proposta mais recente para o tratamento da Hipersensibilidade Dentinária é o uso do biovidro. Esse novo material apresenta a capacidade de promover a formação de hidroxiapatita na superfície da dentina, representando uma união química mais estável e duradoura sobre os túbulos dentinários. Este trabalho comparou o efeito de uma nova formulação de biovidro disperso em ácido fosfórico 30%, associado ao laser de Nd:YAG e ao laser de CO2 na obliteração de túbulos dentinários expostos. Foram obtidas 96 amostras de dentina humana que foram divididas em 6 grupos experimentais (n=16) e distribuídas como a seguir: G1 -­ controle negativo (nenhum tratamento adicional);? G2 -­ laser de Nd:YAG;? G3 -­ laser de CO2;? G4 -­ pasta de biovidro (biovidro + ácido fosfórico 30%);? G5 -­ pasta de biovidro + laser de Nd:YAG;? G6 -­ pasta de biovidro + laser de CO2. Os grupos G5 e G6 foram irradiados com laser de Nd:YAG e laser de CO2, respectivamente, após tratamento com a pasta de biovidro disperso em ácido fosfórico. Ao final do experimento, os grupos foram analisados qualitativamente por Espectroscopia de Infravermelho na Transformada de Fourier (FTIR), Difração de Raios X (DRX), Microscopia Eletrônica de Varredura (MEV) e Espectroscopia de Dispersão de Energia de Raios X (EDS). As análises evidenciaram que a dipersão do biovidro em ácido fosfórico 30% é capaz de formar cristais de hidrogenofosfato de cálcio e, quando a pasta formulada é aplicada sobre a dentina, ocorrem reações químicas com a estrutura dental, formando cristais de monetita. Ao irradiar os cristais formados com laser de Nd:YAG e CO2, ocorreu a desidratação desses cristais, levando à formação de hidroxiapatita. As imagens de MEV demonstram a formação de precipitados cristalinos e amorfos de dimensões variadas sobre a superfície de dentina e na entrada dos túbulos dentinários em todos os grupos que receberam o tratamento com a formulação de biovidro. O laser de CO2 foi capaz de promover alterações na morfologia do material formado de maneira ainda mais evidente especialmente nas dimensões e disposição dos cristais de hidroxiapatita formado sobre a superfície. A análise de EDS evidenciou presença de silício, composto que não está presente naturalmente na estrutura dentária, mas somente na composição do biovidro. Dessa forma, pode-­se concluir que a associação do pó de biovidro com ácido fosfórico 30% permitiu a formação de uma camada de cristais na superfície e entrada dos túbulos dentinários, evidenciando que a pasta formulada viabiliza a aplicação e manutenção do biovidro sobre a superfície dentinária. Sua associação com o laser de Nd:YAG e CO2 parece melhorar a interação desses cristais com a dentina, formando cristais de hidroxiapatita. Nesse estudo, o laser de CO2 promoveu a melhor distribuição e conformação dos cristais sobre a dentina. / Among desensitizing therapies options, the most recent proposal for Dentin Hypersensitivity treatment is the use of bioglass. This new material presents the ability to promote the formation of hydroxyapatite on dentin surface, representing a more stable and lasting chemical bond on dentin tubules. This work compared the effect of a new formulation of bioglass dispersed in 30% phosphoric acid, associated with Nd: YAG laser and CO2 laser in the obliteration of exposed dentin tubules. 96 human dentin samples were obtained, divided into 6 experimental groups (n = 16) and distributed as follows: G1 -­ negative control (no additional treatment);? G2-­ Nd: YAG laser;? G3 - CO2 laser;? G4 -­ bioglass paste (bioglass + 30% phosphoric acid);? G5 -­ bioglass paste + Nd: YAG laser;? G6 -­ bioglass paste + CO2 laser. Groups G5 and G6 were irradiated with Nd:YAG laser and CO2 laser, respectively, after treatment with the slurry dispersed in phosphoric acid. At the end of the experiment, all groups were qualitatively analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-­ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and X-­ray Energy Dispersion Spectroscopy (EDS). The analysis showed that the dispersion of bioglass in 30% phosphoric acid forms calcium hydrogen phosphate crystals and when the formulated paste is applied on dentin surface, chemical reactions occur with the dental structure, forming monetite crystals. When irradiating these crystals with Nd: YAG and CO2 laser, dehydration of these crystals occurred leading to the formation of hydroxyapatite. MEV images demonstrate the formation of crystalline and amorphous precipitates of varying dimensions on the dentin surface and at the entrance of dentinal tubules in all groups receiving treatment with the bioglass formulation. The CO2 laser was able to promote changes in the morphology of the formed material even more evident especially in the dimension and arrangement of hydroxyapatite crystals formed on the surface. The analysis of EDS showed the presence of silicon, a compound that is not naturally present in the tooth structure, but only in the bioglass composition. Thus, it can be concluded that the association of bioglass powder with 30% phosphoric acid allowed the formation of a layer of crystals on the surface and its entrance of the dentinal tubules, evidencing that the formulated paste enables the application and maintenance of bioglass on dentin surface. Its association with the Nd:YAG and CO2 laser seems to improve the interaction of these crystals with dentin, forming hydroxyapatite crystals. In this study. CO2 laser promoted better crystals distribution and conformation on dentin surface.

O objetivo principal deste trabalho foi desenvolver um dispositivo de filme fino com anisotropia de resistividade elétrica. A idéia foi usar um efeito quântico presente em filmes muito finos de materiais condutores ou semicondutores com morfologia anisotrópica na superfície. A morfologia foi um perfil unidirecional quase-senoidal. As resistividades foram determinadas medindo-se as resistências elétricas destes materiais em direções ortogonais, levando-se em conta a geometria da amostra e suas dimensões. O material condutor usado foi Polimetilmetacrilato (PMMA) com ouro implantado na superfície. A profundidade média de implantação foi 2,7 nm. Na fabricação do dispositivo foi utilizada micro e nanolitografia, caracterização por Microscopia Eletrônica de Varredura e Microscopia de Força Atômica e implantação de ouro por MePIIID (Metal Plasma Immersion Ion Implantation and Deposition). / The main purpose of this work was to develop a thin film device with electrical anisotropic resistivity. The idea was to use a quantum effect which is present in very thin films of conductor or semiconductor materials with anisotropic morphology on the surface. The morphology was a sinusoidal-like unidirectional profile. The resistivities were determined measuring the electrical resistances of theses materials in orthogonal directions, taking in account the sample geometry and dimensions. The conductive material used was Polymethylmethacrylate (PMMA) with gold implanted on the surface. The average implanted depth was 2.7 nm. In the device fabrication were used micro and nanolithography, characterization by Scanning Electron Microscopy and Atomic Force Microscopy and gold implantation by MePIIID (Metal Plasma Immersion Ion Implantation and Deposition).

Made available in DSpace on 2017-07-21T20:43:45Z (GMT). No. of bitstreams: 1 Luis Otavio Ribas Lima.pdf: 8124964 bytes, checksum: d16bc8c64f9e15d57f770b1b271d6b3b (MD5) Previous issue date: 2014-06-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Aluminum alloys have been the primary material of choice for the aircraft due to their properties such as low density, high mechanical and corrosion resistance. Commercial aircraft apply aluminum alloys for the fuselage, wings and supporting structure due to the extensive knowledge in design and production of aluminum components, and most importantly, aluminum alloys continue to be developed, keeping it highly competitive. A great development happen with the heat-treatable alloys, which allow improvement of the mechanical properties. Among this alloys stand out the Al-Zn-Mg-Cu series, known for high strength, toughness and corrosion resistance. The improvement of those alloys occurs by the precipitation of nanometric particles MgZn2, called η phase. This study’s aim was to promote an interrupted heat treatment T6I4-65 in an AA7050 aluminum alloy, with fatigue crack growth resistance as priority. Interrupted heat treatments’ goal is optimizing the consumption of solute atoms during process of nucleation and growth of precipitates as a finely dispersion. The T6I4-65 condition obtained was analyzed by differential scanning calorimetry, DSC, optical and electronic microscopy, mechanical tests as hardness, tensile and fatigue crack growth. The T6I4-65 treatment results in a microstructure with a fine dispersion of precipitated phase η’, about 75% smaller than those resulting from in current use, T7451. This microstructure resulted in a reduction of up to 24% in fatigue crack growth rate compared to that resulting from T7451 treatment, keeping the ductility of 17% of area reduction and yield strength higher than 400MPa. / Ligas de alumínio são o principal material de uso na indústria aeronáutica devido a suas propriedades como baixa densidade, alta resistência mecânica e a corrosão. Aeronaves comerciais utilizam ligas de alumínio em sua fuselagem, asas e na estrutura de suporte devido ao extenso conhecimento no projeto e produção de componentes em alumínio, e mais importante, as ligas de alumínio continuam a serem desenvolvidas, mantendo-se altamente competitivas. Ocorreu um grande avanço com o desenvolvimento das ligas tratáveis termicamente, que permitiram a otimização das propriedades mecânicas. Entre estas ligas tratáveis, destaca se a família Al-Zn-Mg-Cu, conhecidas pela alta resistência mecânica, tenacidade e resistência a corrosão. O aperfeiçoamento destas ligas ocorre pela precipitação de partículas nanométricas de MgZn2, conhecida como fase η. O objetivo deste trabalho foi obter um tratamento térmico interrompido T6I4-65 em uma liga de alumínio AA7050 com prioridade ao aumento de resistência à propagação de trinca por fadiga. Tratamentos interrompidos tem por objetivo otimizar o consumo de átomos de soluto durante os processos de nucleação e crescimento dos precipitados endurecedores na liga na forma de dispersão finamente dispersa. A condição T6I4-65 obtida foi analisada por meio de calorimetria diferencial de varredura, DSC, microscopia ótica e eletrônica de varredura e transmissão, ensaios mecânicos dureza, tração e propagação de trinca por fadiga. Este tratamento resultou em uma microestrutura com uma dispersão de finos precipitados de fase η’, cerca de 75% menores que os resultantes de tratamentos de uso corrente, T7451. Esta microestrutura promoveu a redução de até 24% na taxa de propagação de trinca por fadiga em comparação à resultante do tratamento T7451, mantendo grande ductilidade, até 17% de redução de área e limite de escoamento superior a 400MPa.

Dentre as opções de terapias dessensibilizantes, a proposta mais recente para o tratamento da Hipersensibilidade Dentinária é o uso do biovidro. Esse novo material apresenta a capacidade de promover a formação de hidroxiapatita na superfície da dentina, representando uma união química mais estável e duradoura sobre os túbulos dentinários. Este trabalho comparou o efeito de uma nova formulação de biovidro disperso em ácido fosfórico 30%, associado ao laser de Nd:YAG e ao laser de CO2 na obliteração de túbulos dentinários expostos. Foram obtidas 96 amostras de dentina humana que foram divididas em 6 grupos experimentais (n=16) e distribuídas como a seguir: G1 -­ controle negativo (nenhum tratamento adicional);? G2 -­ laser de Nd:YAG;? G3 -­ laser de CO2;? G4 -­ pasta de biovidro (biovidro + ácido fosfórico 30%);? G5 -­ pasta de biovidro + laser de Nd:YAG;? G6 -­ pasta de biovidro + laser de CO2. Os grupos G5 e G6 foram irradiados com laser de Nd:YAG e laser de CO2, respectivamente, após tratamento com a pasta de biovidro disperso em ácido fosfórico. Ao final do experimento, os grupos foram analisados qualitativamente por Espectroscopia de Infravermelho na Transformada de Fourier (FTIR), Difração de Raios X (DRX), Microscopia Eletrônica de Varredura (MEV) e Espectroscopia de Dispersão de Energia de Raios X (EDS). As análises evidenciaram que a dipersão do biovidro em ácido fosfórico 30% é capaz de formar cristais de hidrogenofosfato de cálcio e, quando a pasta formulada é aplicada sobre a dentina, ocorrem reações químicas com a estrutura dental, formando cristais de monetita. Ao irradiar os cristais formados com laser de Nd:YAG e CO2, ocorreu a desidratação desses cristais, levando à formação de hidroxiapatita. As imagens de MEV demonstram a formação de precipitados cristalinos e amorfos de dimensões variadas sobre a superfície de dentina e na entrada dos túbulos dentinários em todos os grupos que receberam o tratamento com a formulação de biovidro. O laser de CO2 foi capaz de promover alterações na morfologia do material formado de maneira ainda mais evidente especialmente nas dimensões e disposição dos cristais de hidroxiapatita formado sobre a superfície. A análise de EDS evidenciou presença de silício, composto que não está presente naturalmente na estrutura dentária, mas somente na composição do biovidro. Dessa forma, pode-­se concluir que a associação do pó de biovidro com ácido fosfórico 30% permitiu a formação de uma camada de cristais na superfície e entrada dos túbulos dentinários, evidenciando que a pasta formulada viabiliza a aplicação e manutenção do biovidro sobre a superfície dentinária. Sua associação com o laser de Nd:YAG e CO2 parece melhorar a interação desses cristais com a dentina, formando cristais de hidroxiapatita. Nesse estudo, o laser de CO2 promoveu a melhor distribuição e conformação dos cristais sobre a dentina. / Among desensitizing therapies options, the most recent proposal for Dentin Hypersensitivity treatment is the use of bioglass. This new material presents the ability to promote the formation of hydroxyapatite on dentin surface, representing a more stable and lasting chemical bond on dentin tubules. This work compared the effect of a new formulation of bioglass dispersed in 30% phosphoric acid, associated with Nd: YAG laser and CO2 laser in the obliteration of exposed dentin tubules. 96 human dentin samples were obtained, divided into 6 experimental groups (n = 16) and distributed as follows: G1 -­ negative control (no additional treatment);? G2-­ Nd: YAG laser;? G3 - CO2 laser;? G4 -­ bioglass paste (bioglass + 30% phosphoric acid);? G5 -­ bioglass paste + Nd: YAG laser;? G6 -­ bioglass paste + CO2 laser. Groups G5 and G6 were irradiated with Nd:YAG laser and CO2 laser, respectively, after treatment with the slurry dispersed in phosphoric acid. At the end of the experiment, all groups were qualitatively analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-­ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and X-­ray Energy Dispersion Spectroscopy (EDS). The analysis showed that the dispersion of bioglass in 30% phosphoric acid forms calcium hydrogen phosphate crystals and when the formulated paste is applied on dentin surface, chemical reactions occur with the dental structure, forming monetite crystals. When irradiating these crystals with Nd: YAG and CO2 laser, dehydration of these crystals occurred leading to the formation of hydroxyapatite. MEV images demonstrate the formation of crystalline and amorphous precipitates of varying dimensions on the dentin surface and at the entrance of dentinal tubules in all groups receiving treatment with the bioglass formulation. The CO2 laser was able to promote changes in the morphology of the formed material even more evident especially in the dimension and arrangement of hydroxyapatite crystals formed on the surface. The analysis of EDS showed the presence of silicon, a compound that is not naturally present in the tooth structure, but only in the bioglass composition. Thus, it can be concluded that the association of bioglass powder with 30% phosphoric acid allowed the formation of a layer of crystals on the surface and its entrance of the dentinal tubules, evidencing that the formulated paste enables the application and maintenance of bioglass on dentin surface. Its association with the Nd:YAG and CO2 laser seems to improve the interaction of these crystals with dentin, forming hydroxyapatite crystals. In this study. CO2 laser promoted better crystals distribution and conformation on dentin surface.

Semiconductors are used in many electronic applications, for example diodes, solar cells and transistors. Typically, semiconductors are inorganic materials, such as silicon and gallium arsenide, but lately more research and development has been devoted to organic semiconductors, for example semiconducting polymers. One of the reasons is that polymers can be customized, to a greater extent than inorganic semiconductors, to create a material with desired properties. Often, two polymers are blended to obtain the desired function, but two polymers do not usually result in an even blend. Instead they tend to separate from each other to varying degrees. The morphology of the blend affects the material properties, for example how efficiently it can convert electricity to light. In this project, thin films consisting of polymer blends were examined using microscopy techniques for the purpose of increasing our understanding of the morphology of such blends. One goal was to investigate whether a technique called correlative light and electron microscopy can be useful for examining the morphology of these films. In correlative light and electron microscopy, a light microscope and an electron microscope are used in the same location in order to be able to correlate the information from the two microscopes. The second goal was to learn about the morphology of the thin films using various microscopy techniques. The polymers used were Super Yellow and poly(ethylene oxide) with large molecular weight. Super Yellow is a semiconducting and light-emitting polymer while poly(ethylene oxide) is an isolating and non-emitting polymer that can crystallize. In the blend films, large, seemingly crystalline structures appeared. The structures could be up to 1 mm in the lateral direction, while the films were only approximately 170 nm thick. These structures could grow after the films had dried and their shapes were similar to those of poly(ethylene oxide) crystals. Consequently, there is reason to believe that it is the poly(ethylene oxide) that makes up the seemingly crystalline structures, but the structures also emitted more light than the rest of the film, and Raman spectroscopy showed that there was Super Yellow in the same location as the crystals. Among the microscopy techniques used, phase contrast microscopy was particularly interesting. This method visualizes differences in optical path length and was useful for studying polymer blends when the polymers have different indices of refraction. Correlating light and electron microscopy showed that there was a pronounced topographical difference between the seemingly crystalline regions and the rest of the thin film. Light microscopy has a limited resolution due to diffraction, but as long as the resolution of the light microscope is sufficient for seeing phase separation, correlative light and electron microscopy turned out to be a good method for studying the morphology of thin films of polymer blends. / Halvledare är viktiga för många elektroniska ändamål eftersom de kan användas till exempelvis dioder, solceller och transistorer. Traditionellt används inorganiska halvledande material som kisel eller galliumarsenid, men på senare tid har allt mer forskning och utveckling inriktat sig mot organiska (kolbaserade) halvledare, såsom halvledande polymerer, bland annat eftersom det i högre utsträckning går att skräddarsy de organiska materialen så att de får önskvärda egenskaper. Ofta blandas två polymerer med varandra för att skapa ett material med nya egenskaper som är önskvärda, men två polymerer brukar inte blandas jämnt utan tenderar att separera från varandra i olika utsträckning. Hur blandningen ser ut (morfologin) påverkar materialets egenskaper, till exempel hur effektivt det omvandlar ström till ljus. Med syfte att öka förståelsen för hur morfologin ser ut hos en blandning av två polymerer, har detta projekt gått ut på att undersöka tunna filmer av polymer-blandningar med hjälp av mikroskopiska tekniker. Ett delmål var att ta reda på om en teknik som heter korrelativ ljus- och elektronmikroskopi är en bra metod för att undersöka morfologin hos dessa filmer. Vid korrelativ ljus- och elektronmikroskopi används både ett ljusmikroskop och ett elektronmikroskop på samma plats för att kunna korrelera informationen som de båda mikroskopen ger. Det andra delmålet var att undersöka vad de olika mikroskopi-teknikerna kan säga om morfologin hos de tunna filmerna. De polymerer som använts är Super Yellow och poly(etylenoxid) med hög molekylmassa. Super Yellow är en oordnad halvledande och ljusemitterande polymer medan poly(etylenoxid) är en isolerande och icke-emitterande polymer som kan kristallisera. I de blandade filmerna uppstod stora kristall-liknande strukturer som kunde vara upp emot 1 mm breda trots att filmerna bara var ungefär 170 nm tunna. Dessa strukturer kunde växa fram efter det att filmerna redan hade torkat och påminde i form om kristaller som kan bildas av poly(etylenoxid). Det finns alltså skäl att tro att det är poly(etylenoxid) som kristalliserats, men de kristall-liknande strukturerna visade sig emittera mer ljus än vad resten av filmen gjorde, och Raman-spektroskopi visade att det även fanns Super Yellow på samma plats som kristallerna. Bland de mikroskopitekniker som testades utmärker sig faskontrastmikroskopi, som visar skillnader i den optiska vägskillnaden (det vill säga faktisk vägskillnad multiplicerat med brytningsindex). Det visade sig vara en intressant teknik för att studera polymerblandningar när de båda polymererna har olika brytningsindex. Genom att korrelera ljus- och elektronmikroskopi visade det sig att det fanns en tydlig skillnad i struktur mellan de kristall-liknande områdena och resten av den tunna filmen. Ljusmikroskopi har begränsad upplösning på grund av ett fenomen som heter diffraktion, men så länge som ljusmikroskopets upplösning är tillräcklig för att se fasseparation visade det sig att korrelativ ljus- och elektronmikroskopi är en bra metod för att studera morfologin hos tunna filmer av polymerblandningar.

Despite the recent development in PLA and PLGA based medical devices, there are still needs to further improve the mechanical performance of bioresorbable medical implants and their bioactivity. This is normally done by optimizing the filler compositions in selected groups ofbiodegradable polymer matrices. In this study, the effects of various filler levels on mechanical strength and thermal properties of PLA and PLGA composites were investigated. Composites containing different dosage of osteoconductive HAp with various particles size (0-5μm, 0-50 μm, nano size), β-TCP, bioactive glass and biodegradable Poly-L-lactide and Polylactide-glycolic acid was manufactured with melt blending, using a twin-screw extruder.The samples were investigated by Differential Scanning Calorimetry (DSC), thermo gravimetric analysis (TGA), Scanning Electron Microscopy (SEM), viscometer, three points bending machine, and Optical Microscopy (OM). The Extruder produced a porous profile. The result from TGA and SEM indicated that there was homogenous filler dispersion in the matrix after compounding.The result from DSC and Viscometer shows that there was some degradation duringcompounding. Mechanical properties of composites were modified by adding filler to matrix. The addition of Bioactive glass, as a filler, increases the degradation of the polymer matrix. The best filler that was applied is 0-5μm and nano HAp. Also in in-vitro degradation part of this thesis work, the effects of calcium phosphate materialsare investigated on degradation process.

Ce travail présente la mise en oeuvre d’un protocole de synthèse de gradients deconcentration dans les oxydes lamellaires riches en Li et en Mn. Le but a été dedévelopper la formation d’oxydes lamellaires riches en Li et Mn au coeur des agrégatssphériques du matériau actif et, en se rapprochant de la surface, d’enrichir lacomposition de l’oxyde lamellaire en Co et en Ni, afin de combiner une forte densitéd’énergie (apportée par le coeur du gradient) et une excellente stabilité thermique etstructurale (apportée par la surface du gradient). La synthèse a été réalisée en deuxétapes, une co-précipitation pour former un carbonate de métaux de transition suivied’une calcination à haute température pour obtenir le matériau actif lithié. L’influencede différents paramètres (pH, débit d’injection, taille du réacteur, composition, …) surla nature du carbonate à gradient de concentration ainsi formé a été étudiée. De lamême façon, le contrôle du ratio Li/M (ici M = Ni, Co, Mn), de la température et de ladurée de calcination s’est révélé important pour parvenir à maintenir le gradient deconcentration dans le matériau lithié. Le ratio Li/M est également déterminant pourcontrôler la nature des matériaux obtenus (lamellaire - spinelle ou lamellaire –lamellaire). Des caractérisations extrêmement pointues, et complexes à mettre enoeuvre, ont été menées afin d’obtenir des informations pertinentes sur la distributiondes phases au sein des agrégats (composition et structure), de la surface au coeur dugradient : différentes techniques de microscopie (EPMA, MEB-EDX et FIB-STEM) ontainsi été largement utilisées. Les matériaux les plus intéressants ont été étudiés enbatteries Lithium-ion avec une électrode de graphite à la négative, les performancesélectrochimiques et la stabilité thermique à l’état chargé de la batterie sont largementdiscutées par rapport à l’état de l’art et notamment au matériau de coeur riche en Li eten Mn. / This work describes in details the implementation of the synthesis protocol for theformation of Li- and Mn-rich layered oxides with concentration-gradients. The purposewas to develop the synthesis of Li- and Mn-rich layered oxides in the bulk of sphericalaggregates of active material and, moving to the surface, to enrich the layered oxides’composition with Co and Ni, in order to combine a high energy density (provided bythe bulk) and an excellent thermal and structural stability (provided by the surface).The synthesis was performed in two steps, a coprecipitation to form a transition metalcarbonate followed by a calcination at high temperature to obtain the lithiated activematerial. The influence of several parameters (pH, feeding rate, size of the reactor,composition …) on the nature of the carbonates formed with concentration-gradientswas studied. Similarly, the control of the Li/M ratio (with M = Ni, Co, Mn) and of thetemperature and duration of calcination was revealed to be important to maintain theconcentration-gradient in the lithiated materials. The Li/M ratio is also the keyparameter to control the nature of the materials obtained (layered - spinel or layered -layered). Advanced characterizations, complex to be implemented, were performed inorder to obtain in-depth information on the distribution of phases within the aggregates(composition and structure), from the bulk to the surface: complementary microscopytechniques (EPMA, SEM-EDS and FIB-STEM) were widely used. The most interestingmaterials were studied in Lithium-ion batteries with graphite at the negative electrode,their electrochemical performance and the thermal stability in the charged state of thebattery were compared to the state of art, and particularly to the bulk Li and Mn-richlayered oxide.