The model-theoretic analysis of the concept of logical consequence has come under heavy criticism in the last couple of decades. The present work looks at an alternative approach to logical consequence where the notion of inference takes center stage. Formally, the model-theoretic framework is exchanged for a proof-theoretic framework. It is argued that contrary to the traditional view, proof-theoretic semantics is not revisionary, and should rather be seen as a formal semantics that can supplement model-theory. Specifically, there are formal resources to provide a proof-theoretic semantics for both intuitionistic and classical logic. We develop a new perspective on proof-theoretic harmony for logical constants which incorporates elements from the substructural era of proof-theory. We show that there is a semantic lacuna in the traditional accounts of harmony. A new theory of how inference rules determine the semantic content of logical constants is developed. The theory weds proof-theoretic and model-theoretic semantics by showing how proof-theoretic rules can induce truth-conditional clauses in Boolean and many-valued settings. It is argued that such a new approach to how rules determine meaning will ultimately assist our understanding of the apriori nature of logic.

A new sensor technology based on optical diffraction of visible light shows promise for sensing metal ions and other species that employ chemically-responsive metal oxide and conducting polymer grating elements. These materials undergo reversible redox processes upon interaction with a chemical analyte that subsequently induces changes in the materials refractive index. The two key design parameters of this sensing technique involve preparation of micropatterned sensor elements and the evaluation of appropriate wavelengths for detection of diffracted light. Much of the ability to “tune” a desired sensing response is dictated by the understanding of how factors of size, dimension, crystallinity, morphology, porosity, and heterogeneity influence analyte/sensor interactions (i.e., adsorption, binding, and transport). The effect of composition, structure, and morphology of MoO₃, WO₃, Moₓ W₁₋ₓO₃, IrOₓ and polyaniline grating materials on chemical, electrochemical and optical properties of these systems will be examined by a range of spectroscopic and electrochemical techniques. Comprehensive evaluation and correlation of materials’ optical properties to diffraction-based detection will advance understanding of the capabilities and limitations for the diffraction-based sensing methodology. This information can then used to determine optimal sensing parameters to improve detection limits, enhance sensitivity and increase the dynamic range for detection of model analytes. / text

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Indirect nuclear spin-spin coupling constants in high resolution nuclear magnetic resonance (NMR) spectroscopy provide the most powerful method for determining conformations and structures of molecules in solution. The research described in this dissertation establishes the conformational and substituent dependencies of several new types of nuclear spin-spin coupling for use in structural studies. It was also of interest to determine the electronic factors which lead to the observed experimental trends. Geminal, vicinal, and four-bond carbon-carbon nuclear magnetic resonance coupling constants were studied experimentally with fifty carbon-13 enriched alicyclic compounds. Because of the small magnitudes of many of these coupling constants it ~vas necessary to modify existing Fourier transform NMR equipment to perform J-resolved two-dimensional NMR experiments. With the greater spectral resolution it was possible to determine 56 intercarbon geminal (²J(cc)), 107 vicinal (³J(cc)) and 26 four-bond (⁴J(cc)) coupling constants. These data represent the largest collection of ²J(cc), the only known data for ⁴J(cc), and the most accurate compilation of vicinal ¹³C-¹³C coupling constants. In combination with molecular orbital methods, the relevant conformational and substituent trends in each of these series were elucidated. Because of the great amount of interest in the importance of bridgehead interactions in "strained" molecules, a study is presented of coupling transmitted via nonbonded interactions between the bridgehead carbons in a series of l-substituted-bicycloalkanes. The two-dimensional Fourier transform methods were again used to obtain the experimental coupling constants and molecular orbital methods were used to determine the importance of the intercarbon bridgehead interactions on ¹H-¹H, ¹³c-¹H, ¹³C-¹³C, ¹³c-¹⁹F , and ¹H-¹⁹F coupling constants. In all cases the nonbonded interactions increased dramatically as the separation between the bridgehead carbons decreased. Further understanding of mechanisms of "through space" coupling were based on NMP. studies of the long range coupling constants (⁵J(HF) and ⁴J(HF)) in N-methyl-8-fluoroquinolinium halides. The X-ray structure of N-methyl-8-fluoroquinolinium chloride was determined in an attempt to calculate the observed ⁵J(HF) and ⁴J(HF). A selective population inversion mIR method was used to show that the sign of ⁵J(HF) in N-ethyl-8- fluoroquinolinium iodide is positive.

No description available.

No description available.

We present and explore a new formulation of perturbative QCD based not on the renormalised coupling but on the dimensional transmutation parameter of the theory and the property of asymptotic scaling. The approach yields a continued function, the iterated function being that involved in the solution of the two-loop β-function equation. In the so-called large-b limit the continued function reduces to a continued fraction and the successive approximants are diagonal Padé approximants. We investigate numerically the convergence of successive approximants using the leading-b approximation, motivated by renormalons, to model the all-orders result. We consider the Adler D-function of vacuum polarisation, the Polarised Bjorken and Gross-Llewellyn Smith sum rules, the (unpolarised) Bjorken sum rule, and the Minkowskian quantities R(_r) and the R-ratio of e(^+)e(^-) annihilation. In contrast to diagonal Fade approximants the truncated continued function method gives remarkably stable large-order approximants in cases where infra-red renormalon effects are important. We also use the new approach to determine the QCD fundamental parameters from the R(_r) and the R-ratio measurements, where we find Ā(^(3))(_MS)=516±48 MeV (which yields a(_s)(µ=m(_r))=0.360(^+0.021)(_=0.020)), and Ā(^(5))(_MS)=299(^+6)(_-7) MeV (which yields a(_s)(µ=m(_zo)=0.1218±0.0004), respectively. The evolution of the former value to the m(_zo) energy results in a(_s)(µ= m(_zo)) = 0.123 ± 0.002. These values are in line with other determinations available in the literature. We implement the Complete Renormalisation Group Improvement (CORGI) scheme throughout all the calculations. We report on how the mathematical concept of Stieltjes series can be used to assess the convergence of Padé approximants of perturbative series. We find that the combinations of UV renormalons which occur in perturbative QCD may or may not be Stieltjes series depending on the renormalisation scheme used.

In den letzten Jahren haben sich die Anwendungsoptionen natürlicher und synthetischer Porphyrinsysteme stark erweitert, was sich auch in der permanent steigenden Anzahl von Publikationen in der Fachliteratur widerspiegelt. Die Inhalte der Veröffentlichungen reichen dabei von grundlegenden Fragestellungen zur Synthese und Charakterisierung über die Untersuchung typischer Eigenschaften bis hin zur Testung der Systeme in der Photovoltaik, als optische Speicher-medien, molekulare Schalter und Drähte oder in der Medizin. Eine interessante Eigenschaft von Porphyrinen besteht darin, nach Lichtanregung Energie an die Umgebung zu übertragen. Diese Beobachtung ist bereits seit etwa 100 Jahren bekannt und hat zur Entwicklung der photodynamischen Therapie (PDT) und Diagnostik (PDD) geführt, die vorteilhaft zur Erkennung und Bekämpfung von Krebs eingesetzt werden kann. Um die Beziehungen zwischen Struktur und Wirkung aufzuklären, ist es notwendig, Porphyrine innerhalb des Grundgerüsts zu modifizieren sowie das Substitutionsmuster gezielt zu variieren. Die logischen Schlüsse, die aus den Untersuchungen der synthetisierten Substanzreihen gezogen werden, können beim Aufbau einer idealen Wirkstruktur helfen, wodurch dessen Wirksamkeit optimiert und die auftretenden Nebenwirkungen minimiert werden können. Im Rahmen dieser Arbeit sollen als potentielle PDT-Agenzien neue meso- und beta-substituierte Thiaporphyrine synthetisiert und charakterisiert werden. Neben dem Einsatz spektroskopischer Methoden in Lösung, wie UV/Vis-, NMR- und Fluoreszenzspektroskopie, sollen vor allem Kristalle für die Röntgeneinkristallstrukturanalyse gezüchtet werden, um charakteristische Bindungsmotive und strukturelle Besonderheiten zu identifizieren. Desweiteren soll durch die Einführung kationischer, funktioneller Gruppen die Löslichkeit der Thiaporphyrine in polaren Lösungsmitteln erhöht werden.

In this study the elastic properties of a fcc Fe0.87Mn0.13 random alloy are studied by ab initio calculations. Ground state lattice parameters and elastic properties are calculated with Density Functional Theory using the Exact Muffin-Tin Orbital method and the Coherent Potential Approximation. Several magnetic models, approximations and distortion techniques are evaluated for optimized results, which are obtained by a Disordered Local Moment model with the Frozen Core and Generalized Gradient approximations using volume-conserving distortions.  Conclusively the longitudinal sound velocities are calculated from second order elastic stiffness constants and visualized by two different codes. The importance of magnetism for elastic properties is confirmed, as is the usefulness of the optimized computational scheme; all quantities obtained via the scheme is in accord with earlier theoretical and experimental results. Volume-conserving distortions are found to be more precise than volume-altering for calculation of elastic constants but also to be highly dependent on the precision of bulk modulus determination. The two sound-velocity codes are in complete agreement.

La simulation de fluide fait l’objet de recherches actives en infographie. Largement utilisée dans le domaine des jeux vidéos ou de l’animation, elle permet de simuler le comportement des liquides, des gaz et autres phénomènes pouvant être apparentés à un fluide. Pour cela, la simulation de fluide dispose d’outils de calcul numériques adaptés, permettant de produire des animations visuellement réalistes pour un temps de calcul raisonnable. Ce mémoire décrit les deux principales approches utilisées en simulation de fluide : l’approche eulérienne et l’approche lagrangienne, ainsi que certains outils numériques associés, que sont les différences finies et les fonctions de lissage. Chaque approche et chaque outil numérique possède ses avantages et ses inconvénients. Les noyaux constants par morceaux constituent un nouvel outil de calcul numérique et ouvrent de nouvelles possibilités à la simulation de fluide. Ils seront étudiés en détails puis intégrés dans une simulation de fluide eulérienne. L’atout notable qu’apportent les noyaux constants par morceaux est la possibilité d’augmenter la précision des calculs là où cela est jugé nécessaire dans la simulation. En augmentant la précision des calculs aux endroits clés, où sont susceptibles d’apparaitre des effets visuellement attrayants comme les tourbillons ou les remous, nous améliorons la qualité des animations.