In the first two chapters we presented the basics of density functional theory and semiempirical LSD+U approximation, which was implemented in the full-potential local-orbital (FPLO) minimal-basis calculation scheme. In the third chapter we tested the implemented version of LSDA+U on 3d transitional metal monoxides. Essential improvement of the spectroscopic properties was obtained. A simple model describing the value and direction of the magnetic moment of a transition metal ion was presented. The model visualizes the interplay of the spin-orbit coupling and crystal field splitting. In the fourth chapter we calculated the electronic spectrum of the single Zn impurity in CuO2 plane considered as a vacancy in Cu 3d states. The analytic solution for the states of different symmetry was obtained. Depending on the strength of perturbation induced by the impurity on the neighboring Cu ions, the states are either resonant or localized. The critical values of the perturbation were computed. In the fifth chapter we presented the calculations for three novel vanadates: MgVO3, Sb2O2VO3 and VOMoO4. The tight-binding parameters and the exchange integrals were computed. The magnesium and antimony vanadates appeared to be spin-½ one-dimensional systems, the latter having much stronger one-dimensional character and being probably the best realization of inorganic spin-Peierls system. The molybdenum vanadate was found to be two-dimensional spin-½ system. The Mo 4d orbitals play an important role in the electronic transfer.

La condensation de Bose-Einstein est prédite par Einstein en 1925 pour des particules indiscernables de spin entier, les bosons. Il s'agit d'une transition de phase vers un état quantique de cohérence macroscopique, dont la température critique dépend directement de la masse des particules. Ce n'est qu'en 1995 qu'un condensat a pu être formé en phase gazeuse en refroidissant des atomes alcalins à la température ultra-basse de 10−6 degré Kelvin, provoquant ainsi une explosion d'activités de recherche dans le monde sur le sujet. Concernant la phase solide, les excitons dans les semi-conducteurs sont<br />considérés comme le candidat le plus prometteur pour la condensation de Bose-Einstein. En e_et leur masse est cent mille fois plus légère que celle des atomes alcalins, ce qui devrait permettre leur condensation<br />à une température voisine du degré Kelvin. Cependant malgré de nombreuses études depuis une trentaine d'années, aucune preuve convaincante de l'existence de condensat d'excitons n'avait été apportée à<br />ce jour. Récemment l'attention s'est portée sur les polaritons dans les microcavités semi-conductrices contenant des puits quantiques. Une microcavité semi-conductrice à puits quantiques est une hétérostructure<br />photonique destinée à exalter l'interaction matière-rayonnement entre les excitons con_nés dans le puits quantique et les photons con_nés dans la microcavité. Lorsque l'énergie de ces photons coïncide avec<br />celle des excitons, la microcavité peut entrer dans le régime de couplage fort d'oscillations de Rabi. Les nouveaux états propres du système (microcavité-puits quantique) sont appelés polaritons qui sont des états<br />mixtes exciton-photon. Par leur nature photonique, ces bosons possèdent une masse dix mille fois plus légère que celle des excitons, un avantage certain pour l'étude de la condensation de Bose-Einstein.<br />Nous avons observé l'occupation massive de l'état fondamental du polariton, qui se développe à partir d'un nuage de polaritons thermalisés à une température de (16-20) K. La formation du condensat est accompagn<br />ée par l'apparition spontanée de la cohérence temporelle et de la cohérence spatiale à longue portée, ainsi qu'une forte polarisation linéaire. La transition d'un état thermique à un état quantique est démontrée par des mesures de la fonction de corrélation d'ordre 2 en fonction de la densité des polaritons. L'ensemble de ces observations constitue la première évidence de la condensation de Bose-Einstein en phase solide.

Ce texte constitue le document de synthèse de l'habilitation à diriger des recherches de l'auteur. Il constitue une présentation des résultats obtenus par l'auteur au cours de son activité de recherche. La liste des articles, dans lesquels ces résultats ont été démontrés, est fournie dans ce texte. Les thèmes de recherche de l'auteur relèvent de la physique mathématique. Ils concernent essentiellement la théorie semi-classique des collisions moléculaires.

Un nouveau modèle de turbulence adapté aux écoulements turbulents soumis à la flottabilité a été développé en utilisant comme référence la configuration du canal plan vertical différentiellement chauffé. L'étude des DNS disponibles pour chacun des régimes de convection a montré les défauts des relations constitutives classiques conduisant à la mauvaise représentation des écoulements de convection naturelle. Ces modèles ne prennent en compte ni le couplage des champs thermique et dynamique ni l'anisotropie de l'écoulement, tous deux induits par la flottabilité. Une approche algébrique a donc été utilisée. L'hypothèse d'équilibre local a été validée dans une large partie du canal sauf dans la région de paroi et au voisinage d'un gradient de vitesse nul, quel que soit le régime de convection. Les modèles homogènes et pariétaux pour les corrélations de pression ont été étudiés et sélectionnés. Deux modèles EARSM et EAHFM prenant en compte les termes de flottabilité ont été développés. Ces modèles intègrent aussi des traitements spécifiques à la paroi reposant sur la pondération elliptique. Ils sont couplés à un modèle k-ω-kθ-r corrigé pour mieux représenter le pic d'énergie cinétique turbulente près de la paroi. Le modèle complet a été confronté aux DNS sur la configuration du canal pour chacun des régimes de convection à travers des tests a priori. Des calculs complets montrent des résultats très encourageants et de meilleures prévisions que les modèles classiques.

Ultra-Relativistic heavy-ion physics is a promising field of high energy physics connecting two fields: nuclear physics and elementary particle physics. Experimental achievements of the last years have provided an opportunity to study the properties of a new state of matter created in heavy-ion collisions called quark-gluon plasma. The initial state of two colliding nuclei is affected by fluctuations coming from wave- functions of nucleons. These fluctuations lead to the momentum anisotropy of the hadronic matter which is observed by the detectors. The system created in the collision behaves like a fluid, so the initial state is connected to the final state via hydrodynamic evolution. In this thesis we model the evolution with relativistic viscous hydrodynamics. Our results, combined with experimental data, give non trivial constraints on the initial state, thus achieving "reverse engineering" of the heavy-ion collisions. The observable which characterizes the momentum anisotropy is the anisotropic flow vn. We present the first measurements of the first harmonic of the anisotropic flow called directed flow v1 in Pb-Pb collisions at the LHC. We then perform the first viscous hydrodynamic modeling of directed flow and show that it is less sensitive to viscosity than higher harmonics. Comparison of these experimental data with the modeling allows to extract the values of the dipole asymmetry of the initial state, which provides constraints on the models of initial states. A prediction for directed flow v1 in Au-Au collisions is also made for RHIC. We then perform a similar modeling of the second and third harmonics of the anisotropic flow, called respectively elliptic v2 and triangular v3 flow. A combined analysis of the elliptic and triangular flow data compared with viscous hydrodynamic calculations allows us to put constraints on initial ellipticity and triangularity of the system. These constraints are then used as a filter for different models of initial state. At the end of this thesis, we show perspectives in the studies of the initial state which are opened by recent measurements of event-plane correlations which could shed light on the initial state fluctuations.

No description available.

Long term data generated at four rural stations are compared to determine similarities and differences in aerosol compositions and factors contributing to observed differences at different regions in Turkey. The stations used in this study are located at Mediterranean coast (20 km to the west of Antalya city), Black Sea coast (20 km to the east of Amasra town), Central Anatolia (&Ccedil / ubuk, Ankara) and Northeastern part of the Anatolian Plateau (at Mt. Uludag). Data used in comparisons were generated in previous studies. However, some re-analysis of data were also performed / (1) to improve the similarities of the parameters compared and (2) to be able to apply recently-developed methodologies to data sets. Data from Mediterranean and Black Sea stations were identical in terms of parameters measured and were suitable for extensive comparison. However, fewer parameters were measured at &Ccedil / ubuk and Uludag stations, which limited the comparisons involving these two stations. Comparison included levels of major ions and elements, short-term and seasonal variations in concentrations, background (baseline) concentrations of elements, flow climatology of regions, correlations between elements, potential source areas affecting regions, and source types affecting chemical composition of particles. Comparison of levels of measured parameters in four regions showed that there are some differences in concentrations that arise from differences in the local characteristics of the sampling points. For example very high concentrations of elements such as Na and Cl in the Mediterranean region is attributed to closer proximity of the Antalya station to coast and not a general feature of the Mediterranean aerosol. There are also significant regional differences in the concentrations of measured elements and ions as well. Concentrations of anthropogenic elements are very similar at two coastal stations (Antalya and Amasra), but they are approximately a factor of two smaller at the two stations that are located on the Anatolian Plateau. This difference between coastal and high altitude plateau stations, which is common to all anthropogenic species, is attributed to different source regions and transport mechanisms influencing coastal regions and Anatolian Plateau. Some statistically significant differences were also observed in the temporal variations of elements and ions measured in different stations. The elements with crustal origin showed similar seasonal pattern at all stations, with higher concentrations in summer and lower concentrations in winter. This difference between summer and winter is attributed to suppression of re-suspension of crustal aerosol from wet or ice-covered surface soil in winter. Concentrations of anthropogenic elements, on the other hand, did not show a statistically significant seasonal trend at Amasra, &Ccedil / ubuk and Uludag stations, but they have higher concentrations during summer months at the Antalya station. This difference between Mediterranean aerosol and aerosol at the Central and Northern Turkey is due to influence of more local sources on &Ccedil / ubuk, Amasra and Uludag stations and domination of more distant source in determining aerosol composition at the Mediterranean region. A similar conclusion of strong influence of local sources on chemical composition of particles at the Central Anatolia was also suggested by the comparison of baseline concentrations in each station. General features in flow climatology (residence times of upper atmospheric air masses) in each region are found to be similar with more frequent flow from W, WNW, NW and NNW wind sectors. Since these are the sectors that include high emitting countries in Eastern and Western Europe and Russia, transport from these sectors are expected to bring pollution from both distant European countries and more local Balkan countries and western parts of Turkey. Flow climatology in stations showed small, but statistically significant, differences between summer and winter seasons. These variations suggested that the station at the Central Anatolia and Black Sea (&Ccedil / ubuk Amasra and Uludag stations) are affected from sources located at the Western Europe in winter season and from sources located at the Eastern Europe in summer. Mediterranean aerosol, on the other hand, are affected from sources at the Western Europe and do not show any seasonal differences. This variation in flow climatology between summer and winter seasons (and lack of variation at the Mediterranean station) is supported by the seasonal variation (and lack of variation at the Mediterranean station) in SO42-/NO3- ratio measured at the stations. Potential source contribution function (PSCF) values are calculated for selected elements and ions in each station. Statistical significance of calculated PSCF values is tested using bootstrapping technique. Results showed that specific grids at Russia and at Balkan countries are common source regions affecting concentrations of anthropogenic elements at all four regions in Turkey. However, each station is also affected from specific source regions as well. Aerosol composition at the Anatolian Plateau are affected from sources closer to the sampling points whereas Mediterranean and Black Sea aerosol are affected from source regions that farther away from the receptors. It should be noted that the same conclusion is also reached in comparison of seasonal patterns and baseline concentrations at these stations. Types of sources affecting aerosol composition at Black Sea, Mediterranean and Central Anatolia are also compared. Source types affecting atmospheric composition in these regions were calculated using positive matrix factorization (PMF). The results showed that aerosol at the Black Sea, Central Anatolia and Mediterranean atmosphere consists of 8, 6 and 7 components, respectively. Two of these components, namely a crustal component and a long-range transport component are common in all three stations. The chemical compositions of these common components are shown to the same within 95% statistical significance interval. Three factors, namely a fertilizer factor, which is highly enriched in NH4+ ion, a sea salt component and an arsenic factor are common in the Mediterranean and Black Sea aerosol but not observed at the Central Anatolia. Other factors found in the regions are specific for that region.

This dissertation explains why behavioral genetic research can be better informed by using characteristics in the human iris as biomarkers for personality, and is divided into five parts. Part I gives an introduction to the classical twin method and an overview of the findings that have led most developmental researchers to recognize that the normal variation of personality depends on a complex interplay between genetic and environmental factors. Part II highlights empirical findings that during the last twenty years have gradually moved genetic and environmental theory and research to evolve toward one another, and also presents the theory of genetics and experience that currently is used to explain how the interplay between genes and the environment works. Part III explains why, from a developmental perspective, it is of interest to identify candidate genes for personality, and gives a brief overview of genes that have been associated with personality. Problems associated with genetic research on the molecular level and how these apply to personality are also highlighted. Part IV examines molecular research on the iris and the brain, which suggests that genes expressed in the iris could be associated with personality, and explains how the use of iris characteristics can increase power to test candidate genes for personality by taking advantage of the self-organizing properties of the nervous system. The empirical foundation for the questions posed in this dissertation and also the empirical results are presented here. Part V discusses the associations found between iris characteristics and personality, and exemplifies how iris characteristics can be used within the theoretical frameworks presented in parts I, II, III and IV. In other words, Part V explains how iris characteristics – in addition to identify as well as test candidate genes for personality – can be used to investigate how people’s experiences in themselves are influenced by genetic factors.

The main objectives of the present project were to increase the understanding of small intestinal precipitation of poorly soluble pharmaceutical drugs, investigate occurrence of crystalline small intestinal precipitation and effects of precipitation on absorption. The aim was to create and evaluate methods of predicting crystalline small intestinal drug precipitation using in vivo, in vitro and in silico models. In vivo small intestinal precipitation from highly supersaturated solutions of two weakly basic model drugs, AZD0865 and mebendazole, was investigated in humans and canine models. Potential precipitation of AZD0865 was investigated by examining dose dependent increases in human maximum plasma concentration and total exposure, which turned out to be dose linear over the range investigated, indicating no significant in vivo precipitation. The small intestinal precipitation of mebendazole was investigated from drug concentrations and amount of solid drug present in dog jejunum as well as through the bioavailability after direct duodenal administration in dogs. It was concluded that mebendazole small intestinal precipitation was limited, and that intestinal supersaturation was measurable for up to 90 minutes. In vitro precipitation methods utilizing simulated or real fasted gastric and intestinal fluids were developed in order to simulate the in vivo precipitation rate. The methods overpredicted in vivo precipitation when absorption of drug was not simulated. An in vitro-in silico approach was therefore developed, where the in vitro method was used for determining the interfacial tension (γ), necessary for describing crystallization in Classical Nucleation Theory (CNT). CNT was evaluated using a third model drug, bicalutamide, and could successfully describe different parts of the crystallization process of the drug. CNT was then integrated into an in silico absorption model. The in vivo precipitation results of AZD0865 and mebendazole were well predicted by the model, but only by allowing the fundamental constant γ to vary with concentration. Thus, the in vitro-in silico approach could be used for small intestinal precipitation prediction if the in vitro concentration closely matched in vivo small intestinal concentrations.

This research was geared towards the investigation of management strategies (factors) that affect the performance ofMSMEs in Kenya. Many developed countries record a time in history when entrepreneurial activities led to revival of economical growth after decline. This implies MSMEs is a very vital sector especially for a developing country like Kenya. MSMEs stagnate and their performance is uncertain according to writers such as Namusonge, Management inadequacies have been suggested in several studies. The objectives of this research was to, 1. To identifY the critical management factors affecting the performance of MSMEs in Kenya; ii. To establish the process through which managerial factors affect the performance of a MSMEs in Kenya ; m. To determine the integrative effect of various management factors in the MSMES in Kenya; IV. To establish the effect of demographics and management factors on performance, v. To establish effects of external environment on internal management factors A conceptual model was formulated from the literature review showing relationships of the management strategies and the environment they operate in. These relationships became the basis for the hypotheses which were later tested. In chapter 4, a mini research (pilot study) was conducted in May 2007,whose main aim was to test the reliability and validity of the research instruments. The 36 questionnaires returned were analysed through descriptive method. Results obtained indicated the instruments were reliable and the results valid. A few corrections suggested were made. The major correction was addition of question 35 to collect financial information. The data collection was done between mid August and mid October 2007.In chapter 5, the researcher analysesd the results of the survey after receiving 180 questionnaires. Time was a constraint. In chapter 6, the hypotheses and conceptual model were analysed and the results obtained suggested that, most strategies did not affect the profitability separately but severally. The integrated effect of the management strategies and the associated factors had a higher impact on performance of the MSMES than any individual strategies. In chapter 7, the conclusions, summaries and Recommendations are given. / Business Management / D. Com. (Business Management and Policy)