Graphene, the thinnest material with a stable 2D structure, is a potential alternative for silicon-based electronics. However, zero band gap of graphene causes a poor on-off ratio of current thus making it unsuitable for logic operations. This problem prompted scientists to find other suitable 2D materials. Creating vacancy defects or synthesizing hybrid 2D planar interfaces with other 2D materials, is also quite promising for modifying graphene properties. Experimental productions of these materials lead to the formation of possible defects and impurities with significant influence in device properties. Hence, a detailed understanding of the effects of impurities and defects on the properties of 2D systems is quite important. In this thesis, detailed studies have been done on the effects of impurities and defects on graphene, hybrid graphene/h-BN and graphene/graphane structures, silicene and transition metal dichalcogenides (TMDs) by ab-initio density functional theory (DFT). We have also looked into the possibilities of realizing magnetic nanostructures, trapped at the vacancy defects in graphene, at the reconstructed edges of graphene nanoribbons, at the planar hybrid h-BN graphene structures, and in graphene/graphane interfaces. A thorough investigation of diffusion of Fe adatoms and clusters by ab-initio molecular dynamics simulations have been carried out along with the study of their magnetic properties. It has been shown that the formation of Fe clusters at the vacancy sites is quite robust. We have also demonstrated that the quasiperiodic 3D heterostructures of graphene and h-BN are more stable than their regular counterpart and certain configurations can open up a band gap. Using our extensive studies on defects, we have shown that defect states occur in the gap region of TMDs and they have a strong signature in optical absorption spectra. Defects in silicene and graphene cause an increase in scattering and hence an increase in local currents, which may be detrimental for electronic devices. Last but not the least, defects in graphene can also be used to facilitate gas sensing of molecules as well as and local site selective fluorination.

The ease of manufacturing using additive manufacturing (3D-Printing) reduces the overall production cost compared with the traditional manufacturing techniques. Because of the benefits of 3D printing technologies, it is proposed to be used in manufacturing of different products. But there are some flaws that are causing significant effect on 3D printed models which degrades the quality of the product. Hence in order to handle these defects, different measurement techniques are needed to quantify the defects that are seen on the surface of 3D-printed models. In our study there are two experimental setups. Experimental setup one was made to find out the proper coating timing to enable measurement using two good samples without defects in different colors blue and red with same material. Different 2D and 3D parameters were used for the surface measurements are collected and noted for further research. The Defective samples are measured using the state of the art equipment at Halmstad University. Experimental setup two was made to prepare the defective samples and measure the samples. The results obtained assisted to quantify the surface defects seen in the samples. This thesis studies some of the different methods that can be implemented to measure the surface defects on the 3D printed models. A little study on the various defects formed on the 3D printed models and what are the causes for the defects on the products were performed. The results suggest different method for the defects to be measured in both industrial and home or small scale office applications.

Birth defects are the leading cause of infant death in the United States. Research has linked poor maternal micronutrient intake to birth defects including neural tube defects, heart defects, and oral clefts. After investigating spatial patterns of these birth defects in the City of Dallas and the neighborhood characteristics within clusters, geospatial access to supermarkets and convenience stores measured by proximity and concentrations are examined as environmental risk factors for nutrition-related birth defects. Spatial clusters of all three nutrition-related birth defects exist in the City of Dallas. Cluster for NTD occurs in vulnerable places with lower income and high minority population specifically Hispanics with no supermarkets. Cluster for heart defects mostly occurs in high income and predominantly white neighborhoods with many supermarkets. Clusters of oral clefts mostly occurs in middle-class income with relatively high minority populations with many convenience stores. For the entire study area, geographical access to supermarkets that include healthy foods are shown to be spatially reachable from most of mothers of infants with nutrition-related birth defects as well as convenience stores that typically include the majority of unhealthy processed foods with very few nutrients. Thus, not only easy geographical access to healthy food vendors but to convenience stores with low quality produces is observed at the same time.

The structural analysis serves as a bridge to link the structure of materials to their properties. Revealing the structure details allows a better understanding on the growth mechanisms and properties of materials, and a further designed synthesis of functional materials. The widely used methods based on X-ray diffraction have certain limitations for the structural analysis when crystals are small, poorly crystallized or contain many defects. As electrons interact strongly with matter and can be focused by electromagnetic lenses to form an image, electron crystallography (EC) approaches become prime candidates for the structural analysis of a wide range of materials that cannot be done using X-rays, particularly nanomaterials with poor crystallinity. Three-dimensional electron diffraction tomography (3D EDT) is a recently developed method to automatically collect 3D electron diffraction data. By combining mechanical specimen tilt and electronic e-beam tilt, a large volume of reciprocal space can be swept at a fine step size to ensure the completeness and accuracy of the diffraction data with respect to both position and intensity. Effects of the dynamical scattering are enormously reduced as most of the patterns are collected at conditions off the zone axes. In this thesis, 3D EDT has been used for unit cell determination (COF-505), phase identifications and structure solutions (ZnO, Ba-Ta3N5, Zn-Sc, and V4O9), and the study of layer stacking faults (ETS-10 and SAPO-34 nanosheets). High-resolution transmission electron microscope (HRTEM) imaging shows its particular advantages over diffraction by allowing observations of crystal structure projections and the 3D potential map reconstruction. HRTEM imaging has been used to visualize fine structures of different materials (hierarchical zeolites, ETS-10, and SAPO-34). Reconstructed 3D potential maps have been used to locate the positions of metal ions in a woven framework (COF-505) and elucidate the pore shape and connectivity in a silica mesoporous crystal. The last part of this thesis explores the combination with X-ray crystallography to obtain more structure details.

In this thesis, we first present a brief overview of various theoretical approaches used to examine the electronic structure of defects in GaN. Using the recently developed hybrid density functional theory (HSE06) along with the experimental measurements, we propose a new explanation of the nature of the yellow luminescence band in carbon-doped GaN. We conduct a systematic study of electronic and optical properties of defects (Carbon, Oxygen, Silicon related) that are candidates for the origin of yellow luminescence. We show that the CN-ON complex is significantly more likely to form compared to isolated carbon configurations. In contrast to the properties of the isolated carbon acceptor, calculated defect levels and optical transitions involving deep level of the CN-ON complex agree quite well with our thermal luminescence quenching data as well as with the experimentally measured C-doped GaN luminescence spectra. Hence, the CN-ON complex, rather than isolated C impurity, is more likely to resolve a long-standing problem of the yellow luminescence in GaN.

Time-resolved photoluminescence (TRPL) measurements paired with steady-state photoluminescence (SSPL) measurements can help to determine the PL lifetime, shape and position of unresolved bands, capture coefficients, and concentrations of free electrons and defects.PL bands that are obscured in the SSPL spectra can be accurately revealed by TRPL measurements. TRPL measurements are able to show if the PL band originates from an internal transition between different states of the same defect. The main defect-related PL bands in high-purity GaN grown by hydride vapor phase epitaxy (HVPE) which have been investigated are the ultraviolet, blue, green, yellow and red luminescence bands (UVL, BL, GL, YL and RL, respectively). The concentration of free electrons can be calculated from these measurements providing a contactless alternative to the Hall effect method. The lifetime of most defect-related PL bands decreases with increasing temperature. However, the lifetime of the GL band, with a maximum at 2.4 eV observed in the SSPL spectra only at high excitation intensity, increases as a function of temperature. By analyzing the PL intensity decay, the origin of the GL can be attributed to an internal transition from an excited state of the CN defect, which behaves as an optically generated giant trap, to the 0/+ level of the same defect. This first observation of an optically generated giant trap was detected by analyzing the cubic temperature dependence of the electron capture coefficient. Excitation intensity and temperature dependent studies on Mg-doped GaN grown by HVPE were performed. The position of the UVL (3.2 eV) peak blue-shifts with increasing excitation intensity, which can be explained by the presence of potential fluctuations. The BL peak (2.8 eV) also blue-shifts with increasing excitation intensity, and red-shifts as a function of temperature. These shifts can be explained by the transitions originating from a deep-donor to the MgGa acceptor, and the corresponding donor-acceptor pair nature.

Liability for Defects in Civil Law The goal of my thesis is to analyze the legal institute of liability for defects in the Czech Civil Law. The main focus is on the Civil Code, complemented by other relevant regulations in the area of liability for defective goods. Due to a major new private law codex that will replace the current Civil Code starting year 2014, thesis also includes new legislation overview and its comparison to the old one. The goal of this paper is to both describe and analyze the issues regarding the liability for defect, its impact and practical aspects related to it. My work draws from current literature and for a better overview of the matter also presents some judicial cases dealing with liability for defects. Thesis is divided into several parts, each dealing with different aspect of liability for defects. First part introduces a reader into civil liability in general and describes its systematics. Next part deals with a current legislation that regulates a civil liability. Third part already goes through the liability for defects and its different dimensions. Fourth part focuses on liability for defects in relation to consumers. In the next section thesis describes different aspects of liability for defects. How the liability for defects is established is a content of the fifth...

Ce travail de thèse propose une méthode générale de reconstruction de défauts. Cette méthode donne un aperçu sur le problème d’observabilité des entrées inconnues. Par la suite, une méthodologie de détection et d’isolation de défauts capteurs et actionneurs est proposée. Le schéma de FDI est basé sur une banque d’observateurs. L’implémentation de cette méthode pour un modèle ASM1 réduit conduit à une table de signature fortement localisante.La deuxième partie porte sur la problématique de « l’observation des systèmes non linéaires ». Le filtre de Kalman étendu (FKE) est l’un des observateurs les plus largement utilisé à cette fin. Cependant, la convergence de cet observateur n’est pas prouvée. Lorsque le FKE est appliqué à un système mis sous une forme canonique d’observabilité, il acquiert, des propriétés de convergence exponentielle globales. Cependant, ce dernier entraine une amplification de bruit. Afin de combiner l’efficacité d’un FKE en termes de lissage de bruit, et la réactivité d’un OKE grand gain face aux larges variations, [Boizot et al., 2010] ont proposé un observateur adaptatif. Ainsi, cet observateur est appliqué au système non-linéaire MIMO d’une station d’épuration biologique. Une étude comparative entre ces trois observateurs est menée afin de mettre en évidence la pertinence de l’observateur adaptatif. / This thesis proposes a general methodology for identifying and reconstructing sensor faults on dynamical processes. This identification theory provides a general framework for the problem of "observability with unknown inputs". Next, a framework for fault detection and isolation of sensors and actuators is proposed. The FDI sheme is based on bank of high-gain observers. A simulation study of a waste water treatment plant shows the effectiveness of the proposed approach.The second point evoked in the thesis is the observability of nonlinear dynamic systems and state estimation. The Extended Kalman Filter (EKF) is a widely used observer for such nonlinear systems. However, it suffers from the lack of theoretical justifications. The EKF, when applied to a system put in a normal form of observability, it acquires the property of global exponential convergence. Unfortunately, this latter observer (HG-EKF) is very sensitive to measurement noise. In order to combine the behaviors of the EKF (efficiency with respect to noise smoothing) and of the HG-EKF (reactivity to large estimation errors), (Boizot et al, 2010) proposed an adaptive high gain observer. This observer is applied to a MIMO nonlinear system of an Activated Sludge Process. A comparison study of the performances of the three observers under consideration is carried out. Results show a clearly better state estimation for the adaptive observer.

O objetivo desta pesquisa foi avaliar a reparação de defeitos de furca classe II em cães tratados com o retalho deslocado coronariamente, sozinho ou em associação com a regeneração tecidual guiada e o enxerto de tecido reparativo de alvéolos utilizando uma análise imuno-histoquímica. Os defeitos foram criados nos 2os, 3os e 4os pré-molares direitos e esquerdos mandibulares em quatro cães sem raça definida. No lado teste de cada cão, após a instrumentação radicular, os defeitos foram enxertados com o tecido reparativo, removidos de locais de extração dental com cinco dias de reparação. As áreas cirúrgicas foram recobertas com membranas absorvíveis e o retalho deslocado coronariamente suturado. No lado controle, após a instrumentação radicular, o retalho também foi deslocado coronariamente e suturado. Após 45 dias os cães foram sacrificados. As análises imuno-histoquímicas para osteonectina, osteopontina e sialoproteína óssea foram feitas no plano vestíbulo-lingual das furcas dos 3os pré-molares. As marcações imuno-histoquímicas foram similares entre os grupos demonstrando que eles provavelmente estavam em um estágio reparativo semelhante. / The aim of this research was to evaluate the repair of class II furcation defects in dogs treated with the coronally positioned flap alone or in association with guided tissue regeneration and post extraction tissue graft using an immunohistochemical analysis. The defects were created on the lower jaw right and left 2nd, 3rd and 4th premolars on four mongrel dogs. On the test side of each dog, after root instrumentation, the defects were grafted with a alveolar socket reparative tissue removed from five days healing teeth extraction sites. The surgical areas were covered with absorbable membranes and a coronally positionated flap was sutured. At the control side, after root instrumentation the coronally positionated flap was sutured. After 45 days, the dogs were sacrificed. The immunohistochemical analyses for osteonectin, osteopontin and bone sialoprotein were done on the bucal-lingual plane extent of the 3rd premolars furcations. The immunohistochemical expressions were similar among the two groups showing that they probably were in a similar healing stage.

Os moinhos de bolas são equipamentos presentes em plantas de mineração, sendo uma máquina importante no circuito de cominuição de minérios. Em função de inúmeros fatores como, por exemplo, projeto, fabricação, sobrecarga no equipamento, falta de manutenção e procedimentos de operação inadequados, são desenvolvidas descontinuidades nos componentes estruturais desse equipamento. Os componentes estruturais dos moinhos, basicamente, corpo, tampas e munhões, além do custo elevado, possuem prazos de fabricação que podem variar de dois a três anos dependendo da demanda do mercado. Portanto é cada vez mais necessário que as descontinuidades detectadas nesses componentes sejam corretamente avaliadas. Neste trabalho analisaram-se pela mecânica da fratura a criticalidade de descontinuidades, tais como trincas constatadas em um munhão de um moinho de bolas e compararam-se os valores teóricos de taxa de propagação (crescimento) dessas descontinuidades com valores reais obtidos por meio de inspeções periódicas realizadas neste componente. A nucleação das trincas foi causada por falta de lubrificação nos mancais do moinho, gerando esforços térmicos circunferenciais no munhão, em que a temperatura estimada do contato munhão e bucha atingiu a faixa de 100 °C a 150 °C. No período analisado, os resultados obtidos por meio da norma BS7910 mostraram-se mais próximos dos valores reais do que a norma ASME Seção XI, Apêndice A. O tamanho da trinca mais crítica foi aceito pelos critérios da norma BS7910 e aprovado apenas na condição de emergência da norma ASME Seção XI, Apêndice A. / The grinding ball mills are equipments present in mining plants, being important in the ore comminution circuits. Depending on numerous factors, such as, for example, design, manufacturing, overloads, poor maintenance and inadequate operating procedures, flaws are developed in the structural components of this equipment. The structural components of a mill, basically, shell, heads and trunnions, besides high costs, have lead times that might vary from two to three years, according to market demand. Therefore, it becomes increasingly necessary that any flaws in those components to be properly evaluated. This paper analyzed the fracture mechanics of the criticality of flaws, such as cracks observed in a ball mill trunnion and compared the theoretical values of growth rate of these defects with actual values obtained through periodic inspections performed in this component. The cracks nucleation was caused by lack of lubrication in the trunnion bearings, generating circumferential thermal stresses, thus the estimated temperature of the trunnion and bushing contact achieved the range 100 °C to 150 °C. During the analyzed period, the results obtained by the standard BS7910 proved to be closest to the actual values than the standard ASME, Section XI, Appendix A. The most critical crack size was accepted by the criteria of the BS7910 and approved only on emergency condition of ASME Section XI, Appendix A.