39 resultados para Mandibular growth
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Tese de doutoramento em Engenharia do Ambiente, especialidade em Sistemas Sociais
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Shape Memory Alloy (SMA) Ni-Ti films have attracted much interest as functional and smart materials due to their unique properties. However, there are still important issues unresolved like formation of film texture and its control as well as substrate effects. Thus, the main challenge is not only the control of the microstructure, including stoichiometry and precipitates, but also the identification and control of the preferential orientation since it is a crucial factor in determining the shape memory behaviour. The aim of this PhD thesis is to study the optimisation of the deposition conditions of films of Ni-Ti in order to obtain the material fully crystallized at the end of the deposition, and to establish a clear relationship between the substrates and texture development. In order to achieve this objective, a two-magnetron sputter deposition chamber has been used allowing to heat and to apply a bias voltage to the substrate. It can be mounted into the six-circle diffractometer of the Rossendorf Beamline (ROBL) at the European Synchrotron Radiation Facility (ESRF), Grenoble, France, enabling an in-situ characterization by X-ray diffraction(XRD) of the films during their growth and annealing. The in-situ studies enable us to identify the different steps of the structural evolution during deposition with a set of parameters as well as to evaluate the effect of changing parameters on the structural characteristics of the deposited film. Besides the in-situ studies, other complementary ex-situ characterization techniques such as XRD at a laboratory source, Rutherford backscattering spectroscopy(RBS), Auger electron spectroscopy (AES), cross-sectional transmission electron microscopy (X-TEM), scanning electron microscopy (SEM), and electrical resistivity (ER) measurements during temperature cycling have been used for a fine structural characterization. In this study, mainly naturally and thermally oxidized Si(100) substrates, TiN buffer layers with different thicknesses (i.e. the TiN topmost layer crystallographic orientation is thickness dependent) and MgO(100) single crystals were used as substrates. The chosen experimental procedure led to a controlled composition and preferential orientation of the films. The type of substrate plays an important role for the texture of the sputtered Ni-Ti films and according to the ER results, the distinct crystallographic orientations of the Ni-Ti films influence their phase transformation characteristics.
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In this paper, the determinants of growth of aggregate health expenditures are investigated. The study departs from previous literature in that it looks at differences across countries in growth (and not levels) of health care expenditures. Estimation is made for 24 OECD countries. Health system characteristics usually believed to influence health expenditures growth, like population ageing, the type of health system (public reimbursement, public contract or integrate) and existence of gatekeepers, are found to be non-significant. Nevertheless, there is evidence that health expenditures experienced a clear slower growth in the last decade. The explanation for this slowdown could not be found in the proposed model and should stimulate further research.
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Quimica Nova, Vol. 32, Nº2
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International Biodeterioration & Biodegradation,xxx (2009) 1–8
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Dissertation for the Master Degree in Structural and Functional Biochemistry
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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Dissertation presented to obtain the Ph.D degree in Developmental Biology
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We conduct a systematic study of the impact of European Union (EU) regional policies on regional economic growth that controls for national policies and geographic characteristics. Special care is taken in distinguishing between the impact of EU policies and of national policies on economic growth. Our empirical study tries to answer two different questions. First, is there convergence across EU regions, and if so, do regions converge to a common European steady-state or to a national one? Second, how do European and national policies affect regional growth? We find evidence of regional convergence at the national level but not at the European level. In addition we find that trade openness at the national level is associated with regional convergence while European regional policies contribute, though weakly, to regional convergence. Our results suggest that policies that foster market integration – and convergence to a common steady-state - such as the promotion of labour and capital movements across countries and common regulatory policies are as important for European-wide regional convergence as regional structural funds.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics
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This paper aims at analyzing the effects of lobbying over economic growth and primarily welfare. We model explicitly the interaction between policy-makers and firms in a setup where the latter undertakes political contributions to the former in exchange for more restrictive market regulations which induce exit and enhance the profitability of the market. In a sectorial equilibrium, despite stimulating growth, lobbying restricts the market structure and reduces welfare when compared to the free-entry outcome. However, once general equilibrium considerations are taken into account, we find that lobbying may improve welfare over a welfare maximizing free-entry equilibrium, by means of an expansion in aggregate demand. This introduces a new paradigm in the literature about the effects of lobbying over economic performance.