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Knowledge of the reactions between VOCs and atmospheric radicals and oxidants is fundamental to understanding atmospheric chemistry and the formation of air pollution in urban environments. This work describes the development of a new experimental technique for the simultaneous measurement of gas-phase rate coefficients for reactions between multiple VOCs and different atmospheric radicals. The technique is based on the traditional relative rate approach and succeeds in markedly increasing the rate of throughput of target reactions; an improvement necessary when considering the vast number of organic compounds observed in the atmosphere for which experimental oxidation data are not available. New rate coefficients are derived using a suite of the available kinetic literature as reference reactions to calibrate the results over a range of reactivity, thereby reducing the reliance on any single rate coefficient value. This new multivariate method was applied to mixtures containing multiple VOCs with a range in functionalities and under different experimental conditions. Two different atmospherically relevant radicals were tested (OH and Cl) and the technique was adapted to allow for temperature controlled measurements. Rate coefficients for the reactions of eight VOCs (1,2-, 1,3- and 1,4-diethylbenzene, n-pentylbenzene, 2-methylheptane, 2-methylnonane, ethylcyclohexane and 2,3-dimethylpent-1-ene) with OH at room temperature were derived for the first time. Rate coefficients for the reactions of 44 other VOCs with OH were also assessed concurrently with the derivation of these eight new results. A rate coefficient for the reaction between 2-methylheptane and Cl was measured for the first time, alongside the measurement of rate coefficients for the reactions of seven other VOCs with Cl.

The following investigation aims to determine the potential of plant material to produce pigments capable of acting as alternatives to the standard range of process (CMYK) colours used in screen printing. A review of the literature on so-called `natural dyes' reveals the extent of the pre-synthetic (1857) use of a range of dye-plants in the textile and related industries over a period of many centuries. Several plant sources are identified for investigation in the context of this study. Chemical, botanical and historical aspects of these plants are described along with notes on their cultivation and nomenclature. The necessary thickeners and other additives that may be required for the production of a stable ink formulation are also discussed. The establishment of the Cat Hill Ink Garden is described as well as a discussion of other sources of raw material supply. Methods of aqueous extraction, lake production, comparative light fastness and spectral reflectance testing are all described and test results are provided in appendix form. The environmental, economic and health and safety aspects of the new inks is contrasted with the commercial oil-based product as well as a brief discussion of their potential for commercial development. Printed examples by the author and several of his students form the final part of the study and demonstrate the use of both CMYK and other non-primary ink formulations.

The enterprise resource planning (ERP) system industry accounts for $8.8 billion annually. Enterprise resource planning systems are not performing as expected due to implementation barriers, changes in job responsibilities, and access to information; 50% of all information technology failures are due to the implementation of ERP systems. Guided by general systems theory, the purpose of this qualitative case study was to identify key factors underlying an effective ERP system deployment. A structured interview protocol that explored participant perceptions of barriers, changes in job responsibility, and information exchange within and between departments was conducted with a purposeful sample of 20 local government employees. Recorded interviews and field notes were first coded and then sequentially analyzed to finally extract 3 emergent themes that characterized the ERP deployment: (a) efficiencies and inefficiencies, (b) access to information, and (c) future optimism. The recommendations in this study will help managers in local governments and the private sector understand critical considerations when implementing an ERP system. This understanding will influence social change through increasing cost savings by informing managers of the specific challenges faced with implementing an ERP system. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

In this paper, the intersections of deleted digits Cantor sets and their fractal dimensions were analyzed. Previously, it had been shown that for any dimension between 0 and the dimension of the given deleted digits Cantor set of the real number line, a translate of the set could be constructed such that the intersection of the set with the translate would have this dimension. Here, we consider deleted digits Cantor sets of the complex plane with Gaussian integer bases and show that the result still holds.

Superheroes in comic books have been recently used in psychological interventions (e.g. Superhero Therapy, Geek Therapy, Comic Book Therapy, etc.). Previous research has placed focus on the effects of, the experiences of bibliotherapy, cinema therapy, video game effects or "media effects" among other forms of when used in psychological intervention. However, little research has been conducted on the effects of and experience of superhero comic books on mental health. The present study looks to gain understanding of the effect and experience of superhero comic books using qualitative phenomenology. Self-Determination Theory of motivation was used as a guide in interpreting the data. A sample size of 15 participants were selected and interviewed. Phenomenological thematic analysis yielded physiological & emotional reactions, nostalgia, source of coping, moral guidance, social utility, relating to characters, and building knowledge as common themes reported by participants. The essence of experiences or overall experience of participants who read superhero comic books was a form of psychological coping & escape.

This thesis is the collation of four papers, adapted from their original versions as to form here four distinct chapters. In the first chapter we illustrate and solve the pricing problem of a target volatility option (TVO) using three different methodologies. In the second chapter we study the pricing PDE for a general contingent claim involving an asset and its realized volatility, and then solve it for a variety of actual models and payoffs. The third chapter introduces a class of time-changed stochastic processes based on which a martingale asset price evolution can be devised. Pricing equations for volatility-linked derivatives are also obtained in this framework. In the final chapter we analyze one specific model of this class; we conclude that it does show high flexibility in explaining the forward volatility skew dynamics and that it can capture certain interesting stylized facts.

It is well-known that the probabilistic behaviour of financial asset returns is not captured well by the classical Black-Scholes model. The true behaviour will never be perfectly captured in any model, but insight is continually being obtained into our understanding of more sophisticated and realistic models. Much research has been published recently exploring the use of L\'{e}vy process models, which maintain the original \emph{independent stationary increments} assumption present in the Black-Scholes model, but incorporate jumps in the modelling. This investigation seeks to motivate a new class of models, throwing out the stationary increments hypothesis. We argue that certain techniques of trading decision-making are not independent of previous price movements, and the returns, being driven by the trade order flow, will reflect that. From here, we develop two particular such models, which are both diffusion models, and study them for their probabilistic behaviour. The first of these models is a hybrid of the arithmetic and geometric Brownian motions, which has transition probabilities expressible in terms of a spectral expansion involving Legendre functions. The second is a hybrid of the arithmetic Brownian motion and the Cox-Ingersoll-Ross process, and its spectral expansions involve the confluent hypergeometric functions. Having developed these expressions in sufficient detail to do so, we consider the calculation of value-at-risk and expected shortfall in these two models.

The focus of the present work is on the use of magneto hydrodynamics as a flow control device for supersonic and hypersonic vehicles. A three dimensional parabolized Navier Stokes solver was developed to take into account the effects of magnetic fields , by incorporating two magneto-hydrodynamic models. The modified solver was then used to study the effects of magneto-hydrodynamics on a variety of configurations, one study of which involved surrogate model based optimisation procedures. The first component of research involved validation of the low magnetic Reynolds number model model against well documented test cases. Good agreement with the nu- merical test cases for flows past a blunt body and a flat plate boundary layer flow, both in the presence of a magnetic field, was found. A novel application of the method of man- ufactured solutions to the simplified mapeto-hydrodynamic model was made to ensure its Accuracy. Assessment of the procedures used for numerical optimisation, were made against known closed-form solutions, and a theoretical axisymmetric body of revolution. An investigation for an optimal magnetic field configuration, for an over-sped Ram- jet intake was made. It was found that for a suitable choice of magnetic field strength, shock on lip could be achieved. Furthermore, for a suitable choice for the position of the magnetic field source, the design condition can also be satisfied using a weaker mag- netic field. Finally a study examining the use of magnetic fields for flows past a slender body were was performed. Given a suitably orientated dipole source, it was shown that the magnetic field can introduce asymmetries, for an otherwise symmetric flowfield, and thereby introduce side form on the missile.

In this work a high-fidelity low-cost surrogate of a computational fluid dynamics analysis tool was developed. This computational tool is composed of general and physics- based approximation methods by which three dimensional high-speed aerodynamic flow- field predictions are made with high efficiency and an accuracy which is comparable with that of CFD. The tool makes use of reduced-basis methods that are suitable for both linear and non-linear problems, whereby the basis vectors are computed via the proper orthogonal decomposition (POD) of a training dataset or a set of observations. The surrogate model was applied to two flow problems related to high-speed weapon aerodynamics. Comparisons of surrogate model predictions with high-fidelity CFD simulations suggest that POD-based reduced-order modelling together with response surface methods provide a reliable and robust approach for efficient and accurate predictions. In contrast to the many modelling efforts reported in the literature, this surrogate model provides access to information about the whole flow-field. In an attempt to reduce the up-front cost necessary to generate the training dataset from which the surrogate model is subsequently developed, a variable-fidelity POD- based reduced-order modelling method is proposed in this work for the first time. In this model, the scalar coefficients which are obtained by projecting the solution vectors onto the basis vectors, are mapped between spaces of low and high fidelities, to achieve high- fidelity predictions with complete flow-field information. In general, this technique offers an automatic way of fusing variable-fidelity data through interpolation and extrapolation schemes together with reduced-order modelling (ROM). Furthermore, a study was undertaken to investigate the possibility of modelling the transonic flow over an aerofoil using a kernel POD–based reduced-order modelling method. By using this type of ROM it was noticed that the weak non-linear features of the transonic flow are accurately modelled using a small number of basis vectors. The strong non-linear features are only modelled accurately by using a large number of basis vectors.

An investigation into the current methods employed to conserve vorticity in numerical calculations is undertaken. Osher’s flux for the artificial compressibility equations is derived, implemented and validated in Cranfield University’s second order finite volume compressible flow solver MERLIN. Characteristic Decomposition is applied as a method of vorticity conservation in both the compressible and artificial compressibility MERLIN solvers. The performance of this method for vorticity conservation in both these solvers is assessed. Following a discussion of the issues associated with application of limiter functions on unstructured grids three modified versions of the method of Characteristic Decomposition are proposed and tested in both the compressible and incompressible solvers. It is concluded that the method of Characteristic Decomposition is an effective method for improving vorticity conservation and compares favourably in terms of increased computational cost to vorticity conservation through grid refinement.

A novel transition model has been developed for use in CFD simulations of helicopter rotor aerodynamics. The model includes significantly improved physical modelling of the transition processes occurring in the steady and unsteady flows found on helicopter rotors. The model has been coupled with the k-co and k-co SST two equation turbulence models using a novel adaptation of the technique developed by Wilcox for the low Reynolds number k-oa model. The method has been employed to calculate transitional flows occurring in three key ow regimes found in helicopter aerodynamics; that around steady and unsteady aerofoils and that around a hovering helicopter rotor. The performance of the k-co and the k-w SST turbulence models have been investigated for transitional flow simulations and the k-w SST shown to provide substantial improvements for transitional flows containing separations. Dramatic improvements in the computed pressure and skin friction distributions for several aerofoil flows have been observed over those computed using a conventional fully turbulent simulation. Corresponding improvements are observed in the computed lift and drag polars and transition on set is well predicted for both low and high Reynolds number flows. A novel structured/unstructured a priori adapted grid generation strategy has been developed for hovering rotor flows that provides improved rotor solutions for transitional flow analysis. The method offers vast improvements in the preservation of vorticity in the solution at greatly reduced computational expense. Tip vortices have been maintained to a Wake age of 1170 degrees with just 2 million cells per blade. The transition model has then been applied to the high quality rotor solutions and good agreement obtained between computed and experimental results, highlighting that three-dimensional effects have a relatively small effect on hovering rotor transition in-board of the blade tip. I addition, the first known verification of a Navier-Stokes rotor code against the Fogarty semi-analytical rotating at plate case was presented and excellent agreement obtained.