2,950 research outputs found

    Regional income convergence and regional policy in the European Union

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    In this paper we use a generalized entropy index such as the Theil index to analyze regional inequalities in Europe. We proved that there is a synchronization between the convergence and catching-up process of objective 1 regions towards the EU15 average with the reform of the EU regional policy. During the period 1982-1988 the Theil index shows that inequalities between objective 1 regions and non-objective 1 regions have increased while from 1989 onwards the reduction in the inequalities between these two groups has been the norm. We also remark the fact that there are high disparate rates of growth among objective 1 regions both within countries and across countries but our computations show also a trend towards a more balanced growth among objective 1 regions within and across EU countries. This success of the European Union regional policy in objective 1 regions will mean a big opportunity for Central and Eastern European countries and hence the increases in competition arising from an enlarged European market combined with a suitable regional development policy should in the future boost the growth of those countries. In the last part of the paper we made a simulation for the funding envelope from 2007, based on the 2000-2006 budget. We show that the figures of the Agenda 2000 provide enough financial support for 90% of the total CEEC population and for 75% of “current” objective 1 population. Key Words: Regional Policy, European Enlargement, Central and Eastern European Countries, Strategic Planning, Regional Growth, Regional Development

    Electromagnetic interaction between a laser beam and semiconductor nanowires deposited on different substrates: Raman enhancement in Si Nanowires

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    Raman scattering of Si nanowires (NWs) presents antenna effects. The electromagnetic resonance depends on the electromagnetic coupling of the system laser/NW/substrate. The antenna effect of the Raman signal was measured in individual NWs deposited on different substrates, and also free standing NWs in air. The one phonon Raman band in NWs can reach high intensities depending on the system configuration; values of Raman intensity per unit volume more than a few hundred times with respect to bulk substrate can be obtainedRaman scattering of Si nanowires (NWs) presents antenna effects. The electromagnetic resonance depends on the electromagnetic coupling of the system laser/NW/substrate. The antenna effect of the Raman signal was measured in individual NWs deposited on different substrates, and also free standing NWs in air. The one phonon Raman band in NWs can reach high intensities depending on the system configuration; values of Raman intensity per unit volume more than a few hundred times with respect to bulk substrate can be obtaine

    Interaction between a laser beam and semiconductor nanowires: application to the raman spectrum of Si nanowires

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    One presents in this work the study of the interaction between a focused laser beam and Si nanowires (NWs). The NWs heating induced by the laser beam is studied by solving the heat transfer equation by finite element methods (fem). This analysis permits to establish the temperature distribution inside the NW when it is excited by the laser beam. The overheating is dependent on the dimensions of the NW, both the diameter and the length. When performing optical characterization of the NWs using focused laser beams, one has to consider the temperature increase introduced by the laser beam. An important issue concerns the fact that the NWs diameter has subwavelength dimensions, and is also smaller than the focused laser beam. The analysis of the thermal behaviour of the NWs under the excitation with the laser beam permits the interpretation of the Raman spectra of Si NWs, where it is demonstrated that temperature induced by the laser beam play a major role in shaping the Raman spectrum of Si NW

    SiGe/Si nanowire axial heterostructures grown by LPCVD using Ga-Au

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    The use of Ga-Au alloys of different compositions as metal catalysts for the growth of abrupt SiGe/Si nanowire axial heterostructures has been investigated. The heterostructures grown in a continuous process by just switching the gas precursors, show uniform nanowire diameters, almost abrupt compositional changes and no defects between the different sections. These features represent significant improvements over the results obtained using pure Au

    Mercado laboral de las personas discapacitadas en España

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    En este trabajo, partiendo de un análisis inicial basado en el estudio de las políticas públicas dirigidas a las personas discapacitadas y de los problemas en la definición de la discapacidad, se analizan las características sociodemográficas de las personas discapacitadas en edad de trabajan y aquellas que están trabajando. A partir de la información disponible en el Panel de Hogares de la Unión Europea para el año 1998, los resultados obtenidos permiten afirmar que uno de los principales obstáculos para la integración laboral de las personas discapacitadas se sitúa en la primera fase del proceso de inserción, es decir, en pasar de la inactividad a la actividad. Estos resultados tienen implicaciones en las futuras políticas públicas dirigidas a favorecer la integración laboral y social de este colectivo.________________________________In this piece of work, beginning with a preliminary analysis of the public policies for disabled persons and the problems associated to the concept of disability, we analyse the sociodemographics characteristics of working age and employed disabled persons in Spain. Using the data from the European Household Panel for 1998, our results show that the main barrier for the labour integration of the disabled person is found in the first phase of the process, this is to say, from the inactivity to labour activity. These results have implication for the future public policies lead to this specific group

    Interaction between a laser beam and semiconductor nanowires: application to the raman spectrum of Si nanowires

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    One presents in this work the study of the interaction between a focused laser beam and Si nanowires (NWs). The NWs heating induced by the laser beam is studied by solving the heat transfer equation by finite element methods (FEM). This analysis permits to establish the temperature distribution inside the NW when it is excited by the laser beam. The overheating is dependent on the dimensions of the NW, both the diameter and the length. When performing optical characterisation of NWs using focused laser beams, one has to consider the temperature increase introduced by the laser beam. An important issue concerns the fact that the NW's diameter has subwavelength dimensions, and is also smaller than the focused laser beam. The analysis of the thermal behaviour of the NWs under the excitation with the laser beam permits the interpretation of the Raman spectrum of Si NWs. It is demonstrated that the temperature increase induced by the laser beam plays a major role in shaping the Raman spectrum of Si NWs

    Raman spectrum of group IV nanowires: influence of temperature

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    Group IV semiconductor nanowires are characterized by Raman spectroscopy. The results are analyzed in terms of the heating induced by the laser beam on the nanowires. By solving the heat transport equation one can simulate the temperature reached by the NWs under the exposure to a laser beam. The results are illustrated with Si and Si1-xGex nanowires. Both bundles of nanowires and individual nanowires are studied. The main experimental conditions contributing to the nanowire heating are discusse

    Laser Induced Heating of Group IV Nanowires

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    Semiconductor nanowires (NWs) are fundamental structures for nanoscale devices. The excitation of NWs with laser beams results in thermal effects that can substantially change the spectral shape of the spectroscopic data. In particular, the interpretation of the Raman spectrum is greatly influenced by excitation induced temperature. A study of the interaction of the NWs with the excitation laser beam is essential to interpret the spectra. We present herein a finite element analysis of the interaction between the laser beam and the NWs. The resultas are applied to the interpretation of the Raman spectrum of bundles of NW

    Raman spectroscopy in Group IV nanowires and nanowire axial heterostructures

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    The control of the SiGe NW composition is fundamental for the fabrication of high quality heterostructures. Raman spectroscopy has been used to analyse the composition of SiGe alloys. We present a study of the Raman spectrum of SiGe nanowires and SiGe/Si heterostructures. The inhomogeneity of the Ge composition deduced from the Raman spectrum is explained by the existence of a Ge-rich outer shell and by the interaction of the NW with the electromagnetic field associated with the laser beam

    MicroRaman Spectroscopy of Si Nanowires: Influence of Size

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    Si Nanowires (NWs) were studied by Raman microspectroscopy. The Raman spectrum of the NWs reveals important thermal effects, which broaden and shift the one phonon Raman bands. The low thermal conductivity of the NWs and the low thermal dissipation are responsible for the temperature enhancement in the NW under the excitation with the laser beam. We have modeled, using finite element methods, the interaction between the laser beam and the NWs. The Raman spectrum of Si NWs is interpreted in terms of the temperature induced by the laser beam excitation, in correlation with finite element methods (fem) for studying the interaction between the laser beam and the NWs
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