The aim of this work is to use contemporary notation to build theory of Rosser logic, explain in detail its relation to Peano arithmetic, show its Kripke semantics and finally using plural self-reference show the proof of arithmetical completeness. In the last chapter we show some of the properties of Rosser sentences. Powered by TCPDF (www.tcpdf.org)

Parmi les réacteurs de génération IV, le GFR et le VHTR utilisent l'hélium comme caloporteur. Il est nécessaire de contrôler sa qualité chimique. Outre des impuretés radiochimiques et particulaires, il peut contenir H2, CO, CH4, CO2, H2O, O2 et des composés azotés, et doit être purifié en permanence. Au CEA, un pilote permet d'étudier cette purification, réalisée en trois étapes: oxydation de H2 et CO sur CuO, puis deux étapes d'adsorption. L’objectif est de fournir une analyse détaillée des deux premières étapes, en les mettant en œuvre à l'échelle du laboratoire. On montre à l’aide d’une première modélisation que la consommation du lit de CuO est totale, et en régime chimique. Les particules de CuO sont constituées de grains d'environ 200 nm de diamètre. Un deuxième modèle, défini à l'échelle de ces grains, permet de trouver des résultats en accord avec les précédents. Un facteur d'échelle lié à la géométrie entre les constantes cinétiques issues des deux types de modélisation a été mis en évidence. Une compétition entre les réactions d'oxydation du CO et de H2 a été observée. Les énergies d'activation des ces réactions sont de l'ordre de 30 kJ.mol-1. La réaction CO/CuO est favorisée. La simulation numérique du déroulement simultané des deux réactions montre qu'il faut envisager une adsorption préférentielle de CO sur le CuO. Dans le cas de l'étape d'adsorption sur tamis moléculaire de CO2 et H2O, une méthodologie similaire a été mise en œuvre. Les isothermes expérimentales obtenues sont de type Langmuir. Les courbes de percée en sortie d'adsorbeur ont montré que le comportement global du lit était correctement représenté par le modèle retenu / In GEN IV studies on future fission nuclear reactors, two concepts using helium as a coolant have been selected: GFR and VHTR. Among radioactive impurities and dusts, helium can contain H2, CO, CH4, CO2, H2O, O2, as well as nitrogenous species. To optimize the reactor functioning and lifespan, it is necessary to control the coolant chemical composition using a dedicated purification system. A pilot designed at the CEA allows studying this purification system. Its design includes three unit operations: H2 and CO oxidation on CuO, then two adsorption steps. This study aims at providing a detailed analysis of the first and second purification steps, which have both been widely studied experimentally at laboratory scale. A first modelling based on a macroscopic approach was developed to represent the behaviour of the reactor and has shown that the CuO fixed bed conversion is dependent on the chemistry (mass transfer is not an issue) and is complete. The results of the structural analysis of the solids allow considering the CuO as particles made of 200 nm diameter grains. Hence, a new model at grain scale is proposed. It is highlighted that the kinetic constants from these two models are related with a scale factor which depends on geometry. A competition between carbon monoxide and hydrogen oxidation has been shown. Activation energies are around 30 kJ.mol-1. Simulation of the simultaneous oxidations leads to consider CO preferential adsorption. A similar methodology has been applied for CO2 and H2O adsorption. The experimental isotherms showed a Langmuir type adsorption. Using this model, experimental and theoretical results agree

The thesis analyzes the determinants of pharmaceutical expenditures on cardiovascular diseases with particular focus on Central Europe. We show how the pharmaceutical expenditure varies across the countries. We try to empirically verify that factors such as age, GDP, total health expenditure, education and prevalence of a particular disease cause the variation. Applying the fixed effect model on selected countries in the period 2000-2009, we find that the increase in pharmaceutical expenditures on cardiovascular diseases is explained mainly by aging population and prevalence of the diseases. Additionally, countries with higher GDP tend to also have somewhat higher pharmaceutical expenditures on cardiovascular diseases. Key words Pharmaceutical expenditures, cardiovascular diseases, GDP, health expenditure, fixed effect model, prevalence of a disease, aging of population.

In the thesis, we investigate whether hedge fund managers have liquidity timing skills in the fixed income market, foreign exchange market and commodity market, respectively. Managers with the liquidity timing skills can strategically adjust hedge funds exposure to the target financial market based on their forecasts about the future changes in market liquidity. We find empirical evidence that hedge funds in certain categories have the skills to time the liquidity levels in the fixed income market, foreign exchange market and commodity market. We conduct a range of robustness tests, which show that hedge funds still exhibit liquidity timing skills after controlling for the factors that may affect timing ability. In particular, our findings are robust to the usage of leverage, funding constraints, investor redemption restrictions, hedge funds trades on market liquidity, financial crisis, hedge fund data biases, market return and volatility timing, liquidity risk factor, systematic stale pricing and option factors. We also conduct bootstrap analysis to ensure the results are not dependent on the normality assumption. Our investigation is helpful to understand the importance of market liquidity to hedge funds professional portfolio management.

Alterations along the Mississippi River, such as dams and levees, have greatly reduced the amount of freshwater and sediment that reaches the Louisiana coastal area. Several freshwater and sediment diversions have been proposed to combat the associated land loss problem. To aid in this restoration effort a 1-D numerical model was calibrated, validated, and used to predict the response of the river to certain stimuli, such as proposed diversions, channel closures, channel modifications, and relative sea level rise. This study utilized HEC-RAS 4.0, a 1-D mobile-bed numerical model, which was calibrated using a discharge hydrograph at Tarbert Landing and a stage hydrograph at the Gulf of Mexico, to calculate the hydrodynamics of the river. The model showed that RSLR will decrease the capacity of the Lower Mississippi River to carry bed material. The stage at Carrollton Gage is not significantly impacted by large scale diversions

Sometimes, changes in consequences are accompanied by a clear stimulus change explicitly arranged by the experimenter. Other times when new consequences are in effect, there is little or no accompanying stimulus change explicitly arranged by the experimenter. These differences can be seen in the laboratory as multiple (signaled) schedules and mixed (unsignaled) schedules. The current study used college students and a single-subject design to examine the effects of introducing signaled and unsignaled schedules, and the transitions between them. In one phase, a card was flipped from purple to white every time the schedule was switched from VR-3 to FT-10. In another phase, the schedule still changed periodically, but the card always remained on the purple side. Results showed that the participants' responding was controlled by the schedule of reinforcement, by the color of the card, or both. These results suggest that changes in patterns of reinforcement lead to changes in stimulus control. In addition, the stimulus control for a behavior can come from several different sources. During teaching, it may facilitate the development of stimulus control to change the environment when a new behavior is required.

The design approach is currently very diverse for glass. It differs greatly between European countries and there is not one definite method for the design of glass components. Research in this field has a potential for better design optimization and industry professionals express a limitation of tools and knowledge about glass structure design.The purpose of this study is to analyze glass balustrades with point-fixings and to test a structural verification approach using a Finite Element (FE) software. The theory provides insight of glass as a structural material, different interlayers used for laminated glass, joints and connections, as well as design standards, concepts and regulations. Different models of varying configurations and geometries are created from the evaluation of balustrades with point-fixings available on the Swedish market and the theory. The models represent a glass balustrade with 4- or 6-point-fixings and is regarded as a fully toughened laminated glass component with different stiff and standard interlayers. The structural analysis of point-fixed glass balustrades on the Swedish market indicated a lower stress and deflection resistance capacity than the pre-normative Eurocode criterion. Based on the FE calculations, some guidelines for fulfilling the criterion are proposed.To make glass more generally applicable as a load-bearing material, the limitations of the FE-software, and how the parameters affect the calculation results needs to be taken into consideration. In order to evaluate the interlayers used for the model, a parametric study using FE-analysiswas carried out, in which the maximum stresses and deflections for several variations were calculated. A sensitivity analysis of the balustrade was conducted to evaluate various geometric and material parameters and how they affect the FE software-based model. Comparisons of guidelines and national codes for simplified hand-calculation and the FE-approach were made to obtain some understanding of calculation methods used in the glass industry and to evaluate the results of the structural analysis. The study suggests that the FE approach is an effective method for a relatively quick and easy verification of glass balustrades.

This thesis seeks to investigate the vastly varying time to market of newly approved drugs across Europe. Firtsly, I use a country fixed effects model on data of newly approved drugs from 2014 to 2017 from 18 European countries. I investigate the correlations between medication specific characteristics and the launch time and find that drugs intended to treat HIV, rheumatism or hepatitis are correlated with a faster launch time. Orphan drugs, though they represent a third of the dataset are found to be insignificantly correlated with time to market. Using a drug fixed effects model, I research important country characteristics in relation to the launch time and find that countries with higher imports of medications are correlated with a quicker time to market. Countries with larger medication export sectors experience a longer waiting time, which could be linked to companies trying to hinder the parallel export of new drugs.

Fixed bed reactors are widely applicable in a range of chemical process industries. Their ease of use and simplified operation make them an attractive and preferred option in reactor selection, however the geometric complexities within the bed as a result of the unstructured packing has made the design of such beds historically based on pseudo-homogenous models together with correlation-based transport parameters. Low tube-to-particle diameter ratio (N) beds, in particular, are selected for highly exothermic or endothermic reactions, such as in methane steam reforming or alkane dehydrogenation. Due to the large fraction of tube to catalyst particle contact in these low N beds, wall effects induce a mass transfer boundary layer at the wall, and in the case of thermal beds, a simultaneous resistance to heat transfer. Computational Fluid Dynamics (CFD) has been shown to be an accurate tool for experimental validation and predictive analysis of packed beds, and may be used to derive more accurate design parameters for fixed bed reactors. More specifically, the elucidation of dispersion, or the transport of reactant and product within the bed due to molecular diffusion and convective flow is of fundamental interest to the design of fixed beds. Computational Fluid Dynamics was used in this research to study solute dispersion in eight beds of varying N at a range of particle Reynolds numbers in the laminar flow regime. In the first stage of research, flow development was simulated in three-dimensional packed beds of spheres. Then, the reactor wall was sectioned to include a boundary condition of pure methane, from which the solute could laterally disperse into the bed. In the second stage, a two-dimensional representation of the bed was created using the commercial Finite Element Analysis software COMSOL Multiphysics. In these models, axial velocity profiles and radial methane concentration profiles taken from the 3-D models were supplied, and a fitting procedure by use of the Levenberg-Marquardt Least-Squares optimization algorithm was completed to fit radial dispersion coefficients and near-wall mass transfer coefficients to the CFD data. These optimization runs were conducted for all N at a number of bed depths in each case. Two sub-studies were conducted in which a constant velocity profile and a local velocity profile were supplied to the 2-D model, and the optimization re-run. It was found that this two parameter model did not fully account for various mechanisms of dispersion in the bed, namely the increasing rate of dispersion from the tube wall boundary layer up to the bed center, but only accounted for a diffusive-dispersion at the wall and a constant-rate, convective-dispersion everywhere else in the bed. Length dependency of dispersion coefficients were also noted, particularly in the developing sections of the bed. Nevertheless, the combined CFD and optimization procedure proved to be an accurate and time-efficient procedure for the derivation of dispersion coefficients, which may then lend themselves to the standard design of packed bed reactors.

Fixed bed reactors are widely applicable in a range of chemical process industries. Their ease of use and simplified operation make them an attractive and preferred option in reactor selection, however the geometric complexities within the bed as a result of the unstructured packing has made the design of such beds historically based on pseudo-homogenous models together with correlation-based transport parameters. Low tube-to-particle diameter ratio (N) beds, in particular, are selected for highly exothermic or endothermic reactions, such as in methane steam reforming or alkane dehydrogenation. Due to the large fraction of tube to catalyst particle contact in these low N beds, wall effects induce a mass transfer boundary layer at the wall, and in the case of thermal beds, a simultaneous resistance to heat transfer. Computational Fluid Dynamics (CFD) has been shown to be an accurate tool for experimental validation and predictive analysis of packed beds, and may be used to derive more accurate design parameters for fixed bed reactors. More specifically, the elucidation of dispersion, or the transport of reactant and product within the bed due to molecular diffusion and convective flow is of fundamental interest to the design of fixed beds. Computational Fluid Dynamics was used in this research to study solute dispersion in eight beds of varying N at a range of particle Reynolds numbers in the laminar flow regime. In the first stage of research, flow development was simulated in three-dimensional packed beds of spheres. Then, the reactor wall was sectioned to include a boundary condition of pure methane, from which the solute could laterally disperse into the bed. In the second stage, a two-dimensional representation of the bed was created using the commercial Finite Element Analysis software COMSOL Multiphysics. In these models, axial velocity profiles and radial methane concentration profiles taken from the 3-D models were supplied, and a fitting procedure by use of the Levenberg-Marquardt Least-Squares optimization algorithm was completed to fit radial dispersion coefficients and near-wall mass transfer coefficients to the CFD data. These optimization runs were conducted for all N at a number of bed depths in each case. Two sub-studies were conducted in which a constant velocity profile and a local velocity profile were supplied to the 2-D model, and the optimization re-run. It was found that this two parameter model did not fully account for various mechanisms of dispersion in the bed, namely the increasing rate of dispersion from the tube wall boundary layer up to the bed center, but only accounted for a diffusive-dispersion at the wall and a constant-rate, convective-dispersion everywhere else in the bed. Length dependency of dispersion coefficients were also noted, particularly in the developing sections of the bed. Nevertheless, the combined CFD and optimization procedure proved to be an accurate and time-efficient procedure for the derivation of dispersion coefficients, which may then lend themselves to the standard design of packed bed reactors.