The major aim of this thesis has been to contribute to the understanding of the CH$ sb2$/OH/NH$ sb2$ group interactions by means of studies of alcohol-amine mixtures in the gas and liquid phases. / To study these interactions in the gas phase a Burnett type equipment was designed, built and operated at low pressure, obtaining experimental pressure-temperature (P-T) data for various systems including alcohol-amylamine mixtures. The P-T data were reduced by a method developed in this work to give values of second virial coefficients. Measurements on known systems were in excellent agreement with values reported in the literature. A group contribution method for predicting pure compounds and interaction second virial coefficients is presented. This method is equal, or superior to methods already available. / To study the CH$ sb2$/OH/NH$ sb2$ group interactions in the liquid phase, vapor-liquid-equilibrium (VLE) experiments with alcohol-amylamine mixtures were carried out in a Van Ness type apparatus. The raw data were reduced by a novel model free method using the second virial coefficients obtained previously for these mixtures. A group contribution method for predicting vapor-liquid-equilibria of multicomponent multigroup mixtures is proposed. Excellent predictions are obtained with this method. / Finally, computer experiments of Lennard-Jones fluid mixtures were carried out to help in the understanding of the local composition concept. This concept is of fundamental importance not only in the models used in this work but also in numerous other solution models.

The theory of “punctuated equilibrium” suggests that species evolve rapidly during or immediately upon speciation, “punctuating” long periods of little or no morphological evolution. Here I confirm that body size differences within clades of birds and mammals are best explained using a model of punctuated evolution. This allows me to suggest that rates of speciation and extinction are responsible for why there are more small mammals than large, as large mammals likely speciate and go extinct at a higher rate than small mammals, and hence undergo cladogenetic change more often. Likewise, mammals appear to evolve at a higher rate than birds, because mammals, as a whole, speciate and go extinct at a higher rate than birds. Furthermore I show that mass extinctions and competition, i.e. forms of natural selection, do not seem to explain differences in body size between species on a macroevolutionary scale. Taken together, these findings not only contradict the idea that apparently different rates of evolution are due to differential selection intensities, and emphasize the importance of the speciation process in evolution, but raise the intriguing question as to what limits evolution in established species. Here I suggest that phenotypic traits, dependent on one another for development and/or function may constrain evolution by exerting stabilizing selection from within the organism, as opposed to external environmental selection, which has been the main focus of evolutionary studies thus far. / Teorin om "punkterad jämvikt" säger att arter utvecklas snabbt under och omedelbart efter artbildning, vilket "punkterar" långa perioder med lite eller ingen morfologisk föränding. I den här avhandlingen visar jag att skillnader i kroppsstorlek inom klader (grupp med gemensam förfader) hos fåglar och däggdjur förklaras bäst när man använder en modell med punkterad evolution. Detta gör i sin tur att jag kan föreslå att hastigheten var med artbildning och utdöende sker, förklarar varför det finns fler små däggdjur än stora, eftersom stora däggdjur sannolikt bildar nya arter och dör ut med en högre hastighet än små däggdjur. Likaså förefaller däggdjur i sin helhet att evolvera med en högre hastighet än fåglar, detta eftersom däggdjur bildar nya arter och dör ut med en högre hastighet än fåglar. Dessutom visar jag att massutdöenden och konkurrens (naturlig selektion) inte verkar förklara skillnader mellan arter över makroevolutionära skalor (över geologisk tid). Sammantaget motsäger dessa resultat inte bara idén om att skenbart olika hastighet på evolution främst beror på skillnader i selektionstryck utan understryker också vikten av artbildningsprocessen som en viktig faktor som styr evolutionens hastighet. Dessutom leder dessa resultat till frågan om vad som begränsar evolutionen hos redan etablerade arter. Här föreslår jag att fenotypiska karaktärsdrag som är beroende av varandra för sin funktion och utveckling kan begränsa evolutionen genom att utöva stabiliserande selektion inifrån organismen, i motsats till selektion från den omgivande miljön vilket har varit fokus för de flesta evolutionära studier hittills.

This thesis reports a detailed investigation into the use of the Shear Strength Reduction (SSR) method to determine factor of safety values in discontinuum models using the Universal Distinct Element Code. The SSR method depends on the definition of failure within the model and two different criteria were compared: the numerical unbalanced force definition and a more qualitative displacement-monitoring based method. A parametric study was first undertaken, using a simple homogeneous rock slope, with three different joint networks representing common kinematic states. Lessons learned from this study were then applied to a more complex case history used for validation of the SSR method. The discontinuum models allow for the failure surface to propagate based on constitutive models that better idealize the rockmass than simpler methods such as limit equilibrium (e.g. either method of slices or wedge solutions) and even numerical continuum models (e.g. finite difference, finite element). Joints are explicitly modelled and can exert a range of influences on the SSR result. Simple elasto-plastic models are used for both the intact rock and joint properties. Strain-softening models are also discussed with respect to the SSR method. The results presented highlight several important relationships to consider related to both numerical procedures and numerical input parameters. The case history was modelled similar to how a typical forward analysis would be undertaken: i.e. simple models with complexities added incrementally. The results for this case generally depict a rotational failure mode with a reduced factor of safety due to the presence of joints within the rockmass when compared to a traditional limit equilibrium analysis. Some models with large persistence of steeply dipping joints were able to capture the actual failure surface. Softening models were employed in order to mimic the generation and propagation of joints through the rockmass in a continuum; however, only discontinuum models using explicitly defined joints in the model were able to capture the correct failure surface.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23924号 / 工博第5011号 / 新制||工||1782(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 浜地 格, 教授 古川 修平, 教授 杉安 和憲 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

The predictions of non-equilibrium radiation for a Titan aerocapture aeroshell vary significantly amongst Computational Fluid Dynamics (CFD) analyses and are limited by the physical models of the non-equilibrium flow. Of particular interest are the non-equilibrium processes associated with the cyanogen (CN) molecule which is known to be a strong radiator. It is therefore important to have experimental data for these radiating shock layers which will allow for validation of CFD models. Furthermore, a more detailed understanding of the chemical processes that lead to the formation of CN above equilibrium concentration is required. This thesis describes the modelling of the radiation behind a shock using a collisional-radiative (CR) model and presents measurements of radiation intensity behind a shock in simulated Titan and Martian atmospheres. The uncertainties in radiation is more significant at lower speeds (around 5-8 km/s) with these atmospheres when compared to Earth entry. This is due to the formation of CN and because of the highly non-equilibrium nature of the flow. The motivation for this work began with the successful landing of the Huygens probe on the surface of Titan which led to the renewed interest in inter-planetary missions. Thus radiative heating during atmospheric entry to Titan and Mars was the subject of several experimental campaigns and extensive computational analyses. In order to better understand the formation of CN, and the nonequilibrium radiation emitted under such atmospheric conditions, NASA Ames Research Center conducted a series of experiments on their Electric Arc Shock Tube facility, EAST. Furthermore, several research groups in Europe and the United States independently developed CR models to predict the measured levels of radiation. The results from these simulations showed some ma jor discrepancies and highlighted a lack of knowledge and understanding about the fundamental physics behind the formation and decay of the CN molecule and its associated excited states. Based on a comparison of the various simulations with the CR models and the EAST experimental data, it was concluded that the absolute level of peak radiation was well predicted, however, there was a significant discrepancy related to the decay rate of the radiation. Therefore, to add to the relatively small amount of experimental data for these highly non-equilibrium radiating flow conditions, experiments were performed on the X2 shock tube at The University of Queensland with the aim of producing a comprehensive set of benchmark data for Titan entry. The data obtained from these experiments have been used to validate the results from the NASA Ames testing, and due to the large parametric variation, as a source for code validation. In addition to the experimental component of this thesis, an investigation into the simulation of CN non-equilibrium radiation was conducted. It has been previously concluded that there was a significant discrepancy between the experimentally measured radiation decay rate and the predicted value from CR models. Therefore, the primary aim of the simulation work presented in this thesis is to explain the reason behind this discrepancy. Through a parametric study of important reactions combined with an analysis of the reaction set, it was concluded that the coupling between the dissociation of N2 and the formation of CN (through the reaction N2 + C ↔ CN + N) controlled the radiation decay rate. The reason for the super equilibrium concentrations was identified to be a result of the N2 + C ↔ CN + N reaction continuing to over-produce CN after nominal equilibrium values are reached. This is due to the slow build up of N to drive the reverse reaction. Thus it has been shown in this thesis that the behaviour of the CN concentration is controlled by the rate of N2 dissociation. This led to the implementation of a more thorough method for simulating the dissociation process of molecular nitrogen. Therefore, a mono-quantum vibration state specific model that includes excitation and de-excitation reactions for all the vibrational states of nitrogen was incorporated into the CR model developed by Magin et al. The nitrogen vibration state specific model that was implemented was developed by Pierott and is based on SSH theory. The model developed in this thesis is known as the ViSpeN CR model (Vibrationally Specific Nitrogen). The ViSpeN results show significantly better agreement with experimental data in terms of the decay rate, initial rise of the radiation and the overall trends in the data. However, the work in this thesis has shown there are still discrepancies in predicting the absolute level of radiation measured in shock tunnel experiments. This led to the development of a modification to the ViSpeN model (known as ViSpeN-L) which includes a proposed new value for the radiative lifetime of the CN violet transition. The agreement between the experimental data and the ViSpeN-L model is excellent for conditions relevant to Titan entry.

In this thesis I address several neglected issues relating to the theoretical and applied analysis of human capital and the impact of taxation. I begin with the problem of measuring the effective tax rate on human capital accumulation. I develop a forward-looking measure of the effective tax rate that is grounded in human capital theory, allowing for features that differentiate human capital formation from physical capital formation. These features include concavity of the earnings-investment frontier and adjustments in capital utilization through leisure. I argue that the few attempts that have been made to measure the effective tax rate on skill formation are either limited by the fact that they inherit assumptions applicable to the theory of the firm or have dubious theoretical foundations (Chapter Two). The new measure is used to derive the effective tax rate on human capital in 25 OECD countries, including Australia (Chapter Three). While there are numerous general equilibrium models which integrate nominal rigidities of one form or another, little attention has been devoted to nominal rigidities arising from partial indexation of income tax thresholds. No doubt one of the reasons for this gap in the literature is the difficulty associated with introducing a fully specified progressive tax regime into an applied general equilibrium model. I show that this hurdle can be overcome through a zero-profit condition for general equilibrium on the labour market. The condition is integrated into an aggregative model of the economy consisting of two sectors (consumption and education) and two factors of production (skilled and unskilled labour). Since skill formation is endogenous, the model allows us to reopen research into the optimal level of skill formation and the role of government (Chapter Four). An applied general equilibrium version of the model is used to evaluate the impact of recent tax reform proposals on skill formation (Chapter Five). A concluding chapter draws together these lines of enquiry with suggestions for future research (Chapter Six).

Bibliography: p. 648-661. / 2 v. (xviii, 661 p. : ill.([1] col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Economics, 2001

The purpose of this thesis is to assess the effects of China???s growth, investment in higher education and trade liberalisation on China and its neighbouring East Asian economies. The study is conducted within the framework of a dynamic multi-sector, multi-region computational general equilibrium model, which incorporates endogenous capital and skill accumulation. China???s trade liberalisation induces substantial investment spending and accumulation of capital and skilled labour in China and East Asia. There is a positive wage outcome for skilled and unskilled labour in both regions. The expanded trade opportunities with China should compensate East Asia for the loss of exports to the rest of the world. Complementarity exists between the exports of China and East Asia with East Asia supplying China???s skill-intensive manufacturing sectors with components and parts which are then used as inputs into China???s exports. Furthermore, the simulation results indicate that China???s trade reforms will support the industrial upgrading process in China but the impact is more apparent in the long term. As China transforms into a more skill oriented, open and competitive economy, it will impose significant structural adjustments on itself and East Asia. A large increase in the output and exports of low tech manufacturing is seen in China, as well as in the high skill sectors of intermediate manufacturing, durables and traded services. China???s exports and imports surge, further rising its presence in the global trading system. The exports of East Asia to the rest of the world decline across the sectors except for the durables sector. However, the decline in the exports of several sectors in East Asia to the rest of the world was offset by the increase in the exports of these sectors to China.

Thesis (Ph.D.)--University of Tulsa, 1990. / Bibliography: leaves 123-126.

Thesis (Ph.D.)--University of Tulsa, 1988. / Bibliography: leaves 149-154.