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Micromechanics based modeling of high velocity impact response of layered heterogeneous material systemsChen, Xianglei, Chandra, N. January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. N. Chandra, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed June 15, 2004). Includes bibliographical references.
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Elastic properties of ferroelastic LiKSO4 in the temperature range from 20 K to 150 K /Bromberek, Marek, January 2001 (has links)
Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. / Bibliography: leaves 63-70.
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An inverse problem in elastodynamics /Rachele, Lizabeth, January 1996 (has links)
Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (p. [115]-117).
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International competitiveness and its implications on industrial policyAmin, Ruzita Mohd. January 1994 (has links)
Thesis (Ph. D.)--Rensselaer Polytechnic Institute, 1994. / Includes bibliographical references (leaves 202-209).
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TAXATION OF UNITED STATES GENERAL AVIATIONSobieralski, Joseph Bernard 01 May 2012 (has links)
General aviation in the United States has been an important part of the economy and American life. General aviation is defined as all flying excluding military and scheduled airline operations, and is utilized in many areas of our society. The majority of aircraft operations and airports in the United States are categorized as general aviation, and general aviation contributes more than one percent to the United States gross domestic product each year. Despite the many benefits of general aviation, the lead emissions from aviation gasoline consumption are of great concern. General aviation emits over half the lead emissions in the United States or over 630 tons in 2005. The other significant negative externality attributed to general aviation usage is aircraft accidents. General aviation accidents have caused over 8000 fatalities over the period 1994 - 2006. A recent Federal Aviation Administration proposed increase in the aviation gasoline tax from 19.4 to 70.1 cents per gallon has renewed interest in better understanding the implications of such a tax increase as well as the possible optimal rate of taxation. Few studies have examined aviation fuel elasticities and all have failed to study general aviation fuel elasticities. Chapter one fills that gap and examines the elasticity of aviation gasoline consumption in United States general aviation. Utilizing aggregate time series and dynamic panel data, the price and income elasticities of demand are estimated. The price elasticity of demand for aviation gasoline is estimated to range from -0.093 to -0.185 in the short-run and from -0.132 to -0.303 in the long-run. These results prove to be similar in magnitude to automobile gasoline elasticities and therefore tax policies could more closely mirror those of automobile tax policies. The second chapter examines the costs associated with general aviation accidents. Given the large number of general aviation operations as well as the large number of fatalities and injuries attributed to general aviation accidents in the United States, understanding the costs to society is of great importance. This chapter estimates the direct and indirect costs associated with general aviation accidents in the United States. The indirect costs are estimated via the human capital approach in addition to the willingness-to-pay approach. The average annual accident costs attributed to general aviation are found to be $2.32 billion and $3.81 billion (2006 US$) utilizing the human capital approach and willingness-to-pay approach, respectively. These values appear to be fairly robust when subjected to a sensitivity analysis. These costs highlight the large societal benefits from accident and fatality reduction. The final chapter derives a second-best optimal aviation gasoline tax developed from previous general equilibrium frameworks. This optimal tax reflects both the lead pollution and accident externalities, as well as the balance between excise taxes and labor taxes to finance government spending. The calculated optimal tax rate is $4.07 per gallon, which is over 20 times greater than the current tax rate and 5 times greater than the Federal Aviation Administration proposed tax rate. The calculated optimal tax rate is also over 3 times greater than automobile gasoline optimal tax rates calculated by previous studies. The Pigovian component is $1.36, and we observe that the accident externality is taxed more severely than the pollution externality. The largest component of the optimal tax rate is the Ramsey component. At $2.70, the Ramsey component reflects the ability of the government to raise revenue aviation gasoline which is price inelastic. The calculated optimal tax is estimated to reduce lead emissions by over 10 percent and reduce accidents by 20 percent. Although unlikely to be adopted by policy makers, the optimal tax benefits are apparent and it sheds light on the need to reduce these negative externalities via policy changes.
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[en] A CONTRIBUTION TO THE THERMODYNAMICS FORMULATION OF THE ELASTOPLASTICITY ELASTOVISCOPLASTICITY / [pt] UMA CONTRIBUIÇÃO A FORMULAÇÃO TERMODINÂMICA DA ELETOPLASTICIDADE E DA ELASTOVISCOPLASTICADEHERALDO SILVA DA COSTA MATTOS 03 February 2012 (has links)
[pt] A evolução de um corpo pode ser estudada usando-se as equações de conservação de massa, de energia e o Princípio das Potências Virtuais. Para uma modelagem completa é necessário ainda fornecer informações adicionais que caracterizam o comportamento de um dado material, o que é feito através de hipóteses constitutivas. Uma solução dessas equações será mecanicamente admissível se ela não violar a Segunda Lei da Termodinâmica.
Este trabalho apresenta um procedimento sistemático de obtenção de equações constitutivas que satisfazem automaticamente uma versão local da Segunda Lei da Termodinâmica. A teoria
Desenvolvida estende e generaliza os conceitos da Termodinâmica dos Processos irresistíveis, não supondo a priori o desacoplamento da dissipação térmica e da dissipação intrínseca e permitindo a existência de um potencial de dissipação não convexo e não diferenciável.
A partir dessa teoria termodinâmica básica foram desenvolvidos os seguintes tópicos:
- Classificação e análise dos comportamento usuais de sólidos em pequenos deformações(elasticidade, viscoelasticidade, elastoplasticidade e elastoviscoplasticidade).
- Modelagem, simulação numérica e avaliação experimental do acoplamento entre o envelhecimento e a plasticidade em metais e ligas metálicas (endurecimento por precipitação-mudança de fase).
Na final do trabalho apresenta-se uma alternativa de extensão para um contexto de grandes deformações do estudo feito para sólidos, visando a análise de processos de conformação mecânica de metais. / [en] The evolutuion of a body can be studied using the equations of conservation of mass, of energy and the Virtual Power Principle. For a complete modelling it is also necessary to give additional informations that characterize the behaviour of a paticular material. This is done by means of constitutive hypothesis. A solution of these equation Will be mechanically admissible if it does not violate the Second Law of Thermodynamics.
This work presents a systematic procedure to obtain constitutive equations that satisfy automatically a local version of the Second Law of Thermodynamics. The Theory developed here generalizes the classical ideas of the Thermodynamic of Irreversible Process: The uncoupling between the thermic and the intrinsic dissipation is not used as a basic assumption and the existence of a non convex and non differentiable potencial of dissipation is admissible.
Using this basic thermodynamocal theory, the following topics were developed:
- Classification and analysis of the usual behaviour of solids at infinitesimal deformation (elasticity, elastoviscoplasticity).
- Modelling, numerical simulation and experimental evaluation of the coupling between aging and plasticity in metals and alloys (hardening due to precipiation process-change of phase).
At the end this work, it is also presented na alternative of extension of the study made for solids to a finite deformation context, with the purpose of the simulation of metal forming processess.
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[en] STRESS ANALYSIS IN SPHERICAL SHELLS / [pt] ANÁLISE DE TENSÕES EM CASCAS ESFÉRICASJAYME PEREIRA DE GOUVÊA 09 November 2011 (has links)
[pt] São obtidas expressões analíticas para a análise de tensões atuantes em cascas esféricas submetidas aos carregamentos de pressão interna, peso próprio e pressão hidrostática. Apenas a teoria de membrana é utilizada.
O vaso esférico pode ser apoiado por um suporte elástico ou por colunas.
O problema de uma calota apoiada num sólido elástico semi-infinito também é estudado.
Para estas considerações, são utilizadas teorias de flexão para carregamentos axissimétricos aplicados na borda e para carregamentos arbitrários, como também são estudados deslocamentos, em sólidos semi-infinitos, devido a carregamentos axissimétricos ao longo de um anel. / [en] Analytical solutions are obtained for stresses analysis of spherical shells subjected to internal pressure,dead weight and hidrostatic pressure. Only the membrane theory is used.
The spherical vessel is considered supported by continuos elastic support or by columns.
The problem of hemispherical shells supported by na elastic semi infinite solid is studied.
For this considerations, bending theories for axysimetric edge load and for arbitrary load used. Displacements of semi infinite solids are also studied.
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Pharmaceutical expenditure and gross domestic product: Evidence of simultaneous effects using a two-step instrumental variables strategyShaikh, Mujaheed, Gandjour, Afschin 10 October 2018 (has links) (PDF)
This paper estimates the income elasticity of government pharmaceutical spending
and assesses the simultaneous effect of such spending on gross domestic product
(GDP). Using a panel dataset for 136 countries from 1995 to 2006, we employ a
two-step instrumental variable procedure where we first estimate the effect of
GDP on public pharmaceutical expenditure using tourist receipts as an instrumentforGDP.
In the secondstep,weconstructanadjusted pharmaceutical expenditure
series where the response of public pharmaceutical expenditure to GDP is
partialled out and use this endogeneity adjusted series as an instrument for pharmaceutical
expenditure. Our estimations show that GDP has a strong positive
impact on pharmaceutical spending with elasticity in excess of unity in countries
with low spending on pharmaceuticals and countries with large economic freedom.
In the second step, we find that when the quantitatively large reverse effect
of GDP is accounted for, public pharmaceutical spending has a negative effect
on GDP per capita particularly in countries with limited economic freedom.
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Essays on exchange rate pass throughHan, Lu January 2018 (has links)
This dissertation contributes to the theoretical and empirical understandings of international transmissions of exchange rate shocks. It consists of three chapters. The first chapter extends Corsetti and Dedola (2005) and further allows for competition in retail networks. In the model, there are four types of firms interacting with each other including retailing manufacturers, non-retailing manufacturers, specialised retailers and nontradable good producers. The equilibrium depends on the interaction among these four types of firms, which leads to a dynamic and incomplete exchange rate pass through (ERPT) depending on the firms’ share of retail networks. With the standard calibration, the model can generate a high (4-5) long-run trade elasticity without conflicting with a low (0.5-1) short-run elasticity, suggesting that the dynamics of retail networks offer a potential explanation of the trade elasticity puzzle. Chapter 2 investigates the ERPT of Chinese exporters. We propose an estimator that utilises orthogonal dimensions to control for unobserved marginal costs and estimate destination specific markup adjustments to bilateral and multilateral exchange rate shocks. Our estimates suggest that the cost channel accounts for roughly 50% of conventional EPRT estimates. We offer new channels of heterogeneity in firms’ pricing behaviour and provide supporting evidence on the international pricing system. Chapter 3 aims to bridge the gap between theoretical and empirical works on ERPT. I propose a machine learning algorithm that systematically detects the determinants of ERPT. The proposed algorithm is designed to work directly with highly disaggregated firm-level customs trade databases as well as publicly available commodity trade flow datasets. Tested on the simulated data from a realistic micro-founded multi-country trade model, my algorithm is proven to have accuracies around 95% and 80% in simple and complex scenarios respectively. Applying the algorithm to China’s customs data from 2000 to 2006, I document new evidence on the nonlinear relationships among market structures, unit value volatility and ERPT.
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Liquid crystal biosensorsCronin, Thomas January 2011 (has links)
The aim of the thesis was to identify and hence investigate the physical properties of liquid crystals that influence their potential as components of biosensor devices. Silicon surfaces presenting photolithographically fabricated arrays of 50nm thick gold spots were used as the model for a biosensor that detects the surface binding of a biological analyte. The spots ranged in diameter from 2μm to 16μm and their spatial separation varied between 5μm to 40μm. A Self Assembled Monolayer (SAM) of the thiol 3-mercaoptopropionic acid was used to control the surface chemistry of the gold. The responses of the nematic liquid crystals 5CB, E7, ZLI 1695, ZLI 1132 and MDA 01-2012 to were measured by optical microscopy. The spots were seen to induce a tilted planar alignment in the liquid crystals in their nematic phase for spot diameters down to 4μm and for all separations. Anchoring transitions between different tilt angles were observed between spots for some arrays. This was linked to a change in anchoring energy at the gold, possibly stemming from the angle of gold deposition. When heated through the nematic to isotropic phase transition cross defects were observed to nucleate on the gold spots for all spot sizes above 4μm. On cooling through the transition grid patterns of defects were observed to nucleate pinned between the spots for arrays of spots with length scales between 10μm and 20μm. The birefringence and elastic constants K11 and K33 of the liquid crystals were measured for temperatures up to their nematic to isotropic transition points. The birefringences of the liquid crystals at the transition were found to range between 0.003 and 0.007. The device thickness was varied between 7μm and 40μm. Values for the elastic constants were found to range between 1pN and 4pN. The intensity of monochromatic light (670nm) reflected from the arrays as the liquid crystals were cooled through the phase transition was found to increase for smaller values of the elastic constants and found to be highest where the grid of defects on the array was observed most clearly. The effect on the intensity of the birefringence and cell thickness was shown to be small compared to the effect of elasticity. Two possible biosensor designs are proposed. The first would identify the presence of a biological analyte at a surface by the change in alignment of a liquid crystal. This type of sensor would be optimised by carefully controlling the anchoring energy of the liquid crystal at the surface to minimise the quantity of surface binding required to induce an anchoring transition. The second would detect the presence at a patterned surface of an analyte by the defects that form over the pattern as the liquid crystal changes between the nematic to isotropic phases. This type of sensor would be optimised by choosing a liquid crystal with small elastic constants at the phase transition and by designing a patterned surface with length scales between 10microns and 20microns.
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