Chapter 1 introduces the discovery of elemental fluorine by H. Moissan and some uses of inorganic fluoride. Organo fluoro compounds and their place in pharmaceuticals and agrochemicals are also introduced. The general properties of fluorine and the C-F bond are discussed as well as conformational influences such as the fluorine gauche effect. Chapter 2 describes the C-N⁺------F-C charge dipole interactions within protonated amines and explains the influence of a β fluorine on the conformation on various crystalline structures. A number of systems are synthesised which contain this charge dipole interaction, such as four, five and eight membered aza heterocycles. It was demonstrated that these provided a N⁺-C-C-F gauche torsion angle. This electrostatic effect was also observed in the non-protonated N-ethylpyridinium cations possessing a fluorine β to the charged nitrogen. This clearly showed that hydrogen bonding is not playing a part in the observed N⁺-C-C-F gauche interactions and that it is a purely electrostatic effect. Chapter 3 discusses the effort to explore the C-O⁺-------F-C charge dipole interaction and the synthetic approaches that were taken towards candidate substances. However in the event a Grignard reaction on a fluoro cyclohexanone was found to provide an unexpected product where rearrangement followed by fluorine elimination had occurred. Chapter 4 details the experimental procedures for the compounds synthesised in this thesis and an Appendix outlines the detail of 24 crystal structures that were solved during this research.

No description available.

No description available.

No description available.

Conventional charged-particle imaging techniques--such as autoradiography--provide only two-dimensional (2D) images of thin tissue slices. To get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick sections, thus increasing laboratory throughput and eliminating distortions due to registration. In CPET, molecules or cells of interest are labeled so that they emit charged particles without significant alteration of their biological function. Therefore, by imaging the source of the charged particles, one can gain information about the distribution of the molecules or cells of interest. Two special case of CPET include beta emission tomography (BET) and alpha emission tomography (𝛼ET), where the charged particles employed are fast electrons and alpha particles, respectively. A crucial component of CPET is the charged-particle detector. Conventional charged-particle detectors are sensitive only to the 2-D positions of the detected particles. We propose a new detector concept, which we call particle-processing detector (PPD). A PPD measures attributes of each detected particle, including location, direction of propagation, and/or the energy deposited in the detector. Reconstruction algorithms for CPET are developed, and reconstruction results from simulated data are presented for both BET and 𝛼ET. The results show that, in addition to position, direction and energy provide valuable information for 3D reconstruction of CPET. Several designs of particle-processing detectors are described. Experimental results for one detector are discussed. With appropriate detector design and careful data analysis, it is possible to measure direction and energy, as well as position of each detected particle. The null functions of CPET with PPDs that measure different combinations of attributes are calculated through singular-value decomposition. In general, the more particle attributes are measured from each detection event, the smaller the null space of CPET is. In other words, the higher dimension the data space is, the more information about an object can be recovered from CPET.

This thesis examines the properties of transmission and transport of light and charged particles in periodic or quasiperiodic systems of solid state and optics, especially the nonlinear and external field effects and the dynamic properties of these systems.

The gauge-invariant formulation of quantum mechanics is compared to the conventional approach for the case of a one-dimensional charged harmonic oscillator in an electromagnetic field in the electric dipole approximation. The probability of finding the oscillator in the ground state or excited states as a function of time is calculated, and the two approaches give different results. On the basis of gauge invariance, the gauge-invariant formulation of quantum mechanics gives the correct probability, while the conventional approach is incorrect for this problem. Therefore, expansion coefficients or a wave function cannot always be interpreted as probability amplitudes. For a physical interpretation as probability amplitudes the expansion coefficients must be gauge invariant.

Master of Science / Department of Electrical Engineering / William Kuhn / When enough charges accumulate on two objects, the air dielectric between them breaks down to create a phenomenon known as electrostatic discharge (ESD). ESD is of great concern in the integrated circuit industry because of the damage it can cause to ICs. The problem will only become worse as process components become smaller. The three main types of ESD experienced by an IC are the human body model (HBM), the charged device model (CDM), and the machine model (MM). HBM ESD has the highest voltage while CDM ESD has the highest bandwidth and current of the three ESD types. Integrated circuits generally include ESD protection circuitry connected to their pads. Pads are the connection between the IC and the outside world, making them the required location for circuitry designed to route ESD events away from the IC's internal circuitry. The most basic protection pads use diodes connected from I/O to VDD and I/O to ground. A voltage clamp between VDD and ground is also necessary to protect against CDM and MM event types where the device may not yet have a low impedance supply path connected. The purpose of this research is to investigate the performance of ESD circuits and to develop a method for detecting the occurrence of an ESD event in an integrated circuit by utilizing IC fuses. The combination of IC fuses and detection circuitry designed to sense a broken fuse allows the IC to perform a built-in self-test (BIST) for ESD to identify compromised ICs, preventing manufacturers from shipping damaged circuits. Simulations are used to design an optimized protection circuit to complement the proposed ESD detection circuit. Optimization of an ESD pad circuit increases the turn-on speed of its voltage clamps and decreases the series resistance of its protection diodes. These improvements minimize the stress voltage placed on internal circuitry due to an ESD event. An ESD measurement setup is established and used to verify voltage clamp operation. This research also proposes an ESD detection circuit based on IC fuses, which fail during an ESD event. A variety of IC fuses are tested using the ESD measurement setup as well as a TLP setup in order to determine the time and current needed for them to break. Suitable IC fuses have a resistance less than 5 Ω and consistently break during the first trial.

<div> <div> <div> <p>Surfaces and interfaces in ionic solids play a pivotal role in defining the trans- port properties and microstructural evolution in many of the existing and emerging material applications, including energy-related systems such as fuel cells, recharge- able batteries, as well as advanced electronics such as those found in semiconducting, ferroelectric, and piezotronic applications. Here, a variational framework has been developed to understand the effects of ionic species and point defects on the structural, electrochemical and chemomechanical stability of grain boundaries in polycrystalline ceramics. The theory predicts the equilibrium and phase transition conditions of charged interfaces, and quantifies the properties induced by the broad region of electrochemical and chemomechanical influence in front of a grain boundary capable of spanning anywhere from a few angstroms to entire grains. As an example application, the microstructural mechanisms leading to the onset of the flash during electric field assisted sintering were predicted, where the experimentally observed cascading charge flow, resulting in the onset of a flash event was rationalized. Also, the model was applied to describe the effects of grain boundary drag by the interfacially accumulated ionic species and charged defects during grain growth under electrical, chemical, mechanical, or structural driving forces. Finally, abnormal grain growth in ionic solids with an emphasis on the structural and electrochemical character of the grain boundaries was demonstrated. Here, two moving grain boundary types, highly mobile and immobile interfaces are identified, resulting in three grain size populations. </p> </div> </div> </div>

O gás de Bose carregado foi estudado em duas e três dimensões, sendo que no caso bidimensional foram considerados dois tipos distintos de interação: l/r e ln(r). Aplicamos a esses sistemas o método do campo auto-consistente que leva em consideração a interação de curto alcance entre os bosons através de uma correção de campo local. Por meio de cálculos numéricos auto-consistentes determinamos o fator de estrutura S(&#8594k) em um amplo intervalo de densidades. A partir de S(&#8594k) obtivemos a função de correlação dos pares, a energia do estado fundamental que é essencialmente a energia de correlação, a pressão do gás e o espectro de excitações elementares. Calculamos ainda a densidade de blindagem induzida por uma impureza carregada fixada no gás. No limite de altas densidades nossos cálculos reproduzem os resultados da teoria de perturbação de Bogoliubov. Na região de densidades intermediárias em que os sistemas são fortemente correlacionados nossos resultados apresentam uma boa concordância com cálculos baseados na aproximação de HNC e no método de Monte Carlo. Nossos resultados são em várias situações confrontados com os de RPA demonstrando que o método que utilizamos é muito mais adequado para tratar o sistema. Os sistemas bidimensionais mostraram-se mais correlacionados que o tridimensional, sendo que o gás com interação l/r é mais correlacionado que o logarítmico a altas densidades, mas na região de densidades baixas essa situação se inverte. Finalmente calculamos as funções termodinâmicas dos sistemas bi e tridimensionais a temperaturas finitas próximas do zero absoluto baseando-nos nos espectros de excitação do gás a temperatura zero. / The two and three-dimensional charged Bose gas have been studied. In the bidimensional case two different types of interaction were considered: l/r and ln(r).We have applied to these systems the self-consistent-field method, which takes into account the short range correlations between the bosons through a local-field correction. By using self-consistent numerical calculations we determinate the structure factor S(&#8594k) in a wide range of densities. From S(&#8594k) we obtained the pair-correlation function, the ground-state energy, the pressure of the gas and the spectrum of elementary excitations. In addition we calculated the screening density induced by a fixed charged impurity. In the high-density limit our calculations reproduce the results given by Bogoliubov\'s perturbation theory. In the intermediate-density region, corresponding to the strongly coupled systems, our results are in very good agreement with calculations based on HNC approximation as well as Monte Carlo method. Our results are compared in several situations with RPA results showing that the self-consistent method is much more accurate. The two-dimensional systems showed to be more correlated than the three-dimensional one; the gas with interaction l/r is also more correlated than the logarithmic one at high densities, but it begins to be less correlated than this one in the low-density region. Finally we calculated the thermodynamic functions of the two and three-dimensional systems at finite temperatures near absolute zero, based upon the gas excitation spectra at zero temperature.