Tese aborda, inicialmente, a mobilidade de médicos pelo mundo a partir de levantamento bibliográfico em base de dados. Identifica a escassez de informações referentes aos médicos brasileiros, apesar de existirem algumas evidências a respeito da emigração destes profissionais para exercerem sua profissão em outros países. OBJETIVO: analisar aspectos que determinam a emigração de médicos brasileiros para os EUA. METODOLOGIA: a principio foi realizada uma etapa exploratória, seguida de levantamento de dados em conselhos de classe brasileiros e sites norte-americanos. Utilizou-se uma amostra por conveniência através da técnica \"bola de neve\"; identificou-se a existência de médicos que emigraram; foi enviado, via e-mail, questionário elaborado pela autora com questões fechadas e abertas a respeito dos motivos pelos quais escolheram os EUA para emigrar, por que foram, por que ficaram, por que voltariam e por que não voltariam a morar no Brasil. Realizadas algumas entrevistas por Skype. Foi realizada a tabulação dos dados quanti e qualitativos. RESULTADOS: inicialmente os médicos escolhem emigrar por motivos pessoais (família, oportunidades profissionais, oportunidades em geral, facilidade do idioma); ao se estabelecerem nos EUA vivenciam uma nova forma de vida, o que os faz escolher permanecer (melhores condições de trabalho, qualidade de vida, família e oportunidades gerais); as causas do não retorno ao Brasil passam a ter motivos externos (insegurança, cenários profissional, politico e econômico). CONCLUSÃO: existe um processo emigratório de médicos brasileiros para os EUA; a principio a vontade de emigrar não está bem definida; o salário não é citado como questão primordial para emigrar; a presença da família facilita a permanência no país; fluência na língua inglesa é fundamental e é necessário recomeçar a vida profissional como um recém-formado em medicina pois não existe processo de validação de diploma ou de especialidades / OBJECTIVE: to analyze aspects that determine the emigration of Brazilian doctors to the United States of America. METHODOLOGY: at first there was an exploratory stage, followed by a data collection in Brazilian professional associations and North American websites. A sample by convenience was used through the \"snowball\" technique; the existence of doctors that emigrated was identified; a questionnaire, elaborated by the author with closed and open questions, was sent by e-mail, regarding their motives to choose the USA to emigrate, why they have gone, why they stayed and why they would or wouldn\'t come back to live in Brazil. A few interviews were made by Skype. A tabulation of the quantitative and qualitative data was made. RESULTS: initially the doctors choose to emigrate for personal motives (family, professional opportunities, general opportunities, no language barriers); when established in the USA, they experience a new way of life that makes them stay (better work condition, quality of life, family and general opportunities); external motives become the cause not to come back to Brazil (the lack of security, professional, political and economic scenarios). CONCLUSION: there is an emigrational process of Brazilian doctors to the USA; at first the will to emigrate is not well defined; the salary is not mentioned as a primal reason to emigrate; the presence of the family eases the stay in the country; the proficiency in the English language is fundamental and it is necessary to restart the professional life as a recently graduated in med school since there isn\'t an university degree or medical specialty degree validation.

Il est communément admis que les écoulements dans les aquifères karstiques sont particulièrement concentrés dans les conduits et les fractures principaux. Dans ce travail, on cherche à décrire le comportement du flux à différentes échelles. A l'échelle locale, on considère une modélisation des écoulements en milieu continu. A cela s'ajoute à l'échelle régionale l'inclusion de drains comme éléments discrets (approche hybride). Nous avons recours pour ceci à l'utilisation d'un modèle d'écoulement défini par des équations aux dérivées partielles qui décrivent l'écoulement dans un milieu à double-porosité. La solution analytique de ce modèle nous permet d'étudier les phases de transition des flux selon une condition à la limite de type charge imposée. Cela correspond à une perturbation hydraulique tel qu'un puits maintenu à charge constante. Afin d'inclure des conditions aux limites spécifiques (par exemple une limite imperméable) et une géométrie de domaine irrégulière, nous développons et employons un modèle numérique basée sur la méthode des éléments intégrales de frontière. Ceci permet de mettre en oeuvre l'approche hybride (milieu continu et discret) dans laquelle nous considérons les intersections entre conduits verticaux et horizontaux. Ce type de modélisation permet ainsi de considérer une échelle plus importante qu'un modèle continu seul.Par ailleurs, un modèle expérimental de laboratoire est conçu et réalisé afin d'étudier expérimentalement les phases de transition du flux issu de milieux hétérogènes. Cette approche est complémentaire de celle développée à l'aide de la solution analytique et du modèle numérique.Enfin, nous proposons le développement et les essais préliminaires d'un nouvel instrument de mesure. Il s'agit d'une sonde autonome qui a pour objectif de cartographier les conduits noyés dans les aquifères karstiques. Ainsi la géométrie des drains discrets pourra être représentée de façon plus réaliste dans le modèle numérique hybride.Les conclusions principales de ce travail sont les suivantes : à l'échelle locale et régionale, les phases de transition du flux dépendent des propriétés hydrauliques du milieu. La solution numérique permet d'étudier l'influence des géométries de domaine et de conditions aux limites complexes. Le modèle expérimental permet de reproduire qualitativement les phases de transition du flux analysées théoriquement. Enfin, la sonde permet de cartographier son parcours dans des conditions expérimentales contrôlées. Ces nouvelles méthodes contribuent à la caractérisation de l'hydrodynamique dans les aquifères karstiques. / Groundwater flow in karst aquifers is mainly concentrated into the principals hydraulic features such as conduits and fractures. This work is devoted to the description of the flow behavior at different scales. At the local scale, we model the groundwater flow with a continuum approach. At the regional scale however, we describe the groundwater flow by mean of a hybrid modeling approach that considers discret conduits and a multi continuum approach.We use in this work a groundwater flow model based on the double porosity approach. The analytical solution of this model allows to investigate the different flow transitions phases that are present when a constant head boundary condition is applied, for instance at a well.In order to include different boundary conditions as well as specific domain geometries, we apply in this work a boundary element method to solve the partial differential equations that describe our problem. This allows to further investigate the hybrid model (discret element and multi continuum) in which we consider discret intersections of vertical conduits with horizontal conduits. This modeling approach allows to consider a broader scale that the local scale to describe groundwater flow in karst aquifers.Asides, a physical experiment is developped in order to study experimentally the transition phases of the flow which comes from a heterogeneous reservoir. This approach is complementary to those developped with the analytical and the numerical studies. Finally, a new measuring instrument is developped and early field trials were carried out in this work. This new sensor is an autonomous underwater probe which aims to map unaccessible drowned karst conduits. With this tool, the geometry of the karst conduits will be more realisticly represented in the hybrid numerical model.The main conclusions of this work are the following : at the local and regional scales, the transition periods in the flux depend of the hydraulic properties of the reservoir. The numerical solution allow to study the influence of various complex domain geometries and boundary conditions. The physical experiment allows to reproduce qualitatively the transition periods in laboratory conditions. Finally, the autonomous sensor allows to map its path in controlled field conditions.These new approaches and methods contributes to the caracterisation of the hydrodynamical behavior of karst aquifers.

As a consequence of an aging workforce, electric utilities are at risk of losing their most experienced and knowledgeable electrical engineers. In this research, the problem was a lack of understanding of what electric utilities were doing to capture the tacit knowledge or know-how of these engineers. The purpose of this qualitative research study was to explore the tacit knowledge capture strategies currently used in the industry by conducting a case study of 7 U.S. electrical utilities that have demonstrated an industry commitment to improving operational standards. The research question addressed the implemented strategies to capture the tacit knowledge of retiring electrical engineers and technical personnel. The research methodology involved a qualitative embedded case study. The theories used in this study included knowledge creation theory, resource-based theory, and organizational learning theory. Data were collected through one time interviews of a senior electrical engineer or technician within each utility and a workforce planning or training professional within 2 of the 7 utilities. The analysis included the use of triangulation and content analysis strategies. Ten tacit knowledge capture strategies were identified: (a) formal and informal on-boarding mentorship and apprenticeship programs, (b) formal and informal off-boarding mentorship programs, (c) formal and informal training programs, (d) using lessons learned during training sessions, (e) communities of practice, (f) technology enabled tools, (g) storytelling, (h) exit interviews, (i) rehiring of retirees as consultants, and (j) knowledge risk assessments. This research contributes to social change by offering strategies to capture the know-how needed to ensure operational continuity in the delivery of safe, reliable, and sustainable power.

The effectiveness of seismic retrofitting applied to enhance seismic performance was assessed for a five-story reinforced concrete (RC) flat-slab building structure in the central United States. In addition to this, an assessment of seismic fragility that relates the probability of exceeding a performance level to the earthquake intensity was conducted. The response of the structure was predicted using nonlinear static and dynamic analyses with synthetic ground motion records for the central U.S. region. In addition, two analytical approaches for nonlinear response analysis were compared. FEMA 356 (ASCE 2000) criteria were used to evaluate the seismic performance of the case study building. Two approaches of FEMA 356 were used for seismic evaluation: global-level and member-level using three performance levels (Immediate Occupancy, Life Safety and Collapse Prevention). In addition to these limit states, punching shear drift limits were also considered to establish an upper bound drift capacity limit for collapse prevention. Based on the seismic evaluation results, three possible retrofit techniques were applied to improve the seismic performance of the structure, including addition of shear walls, addition of RC column jackets, and confinement of the column plastic hinge zones using externally bonded steel plates. Finally, fragility relationships were developed for the existing and retrofitted structure using several performance levels. Fragility curves for the retrofitted structure were compared with those for the unretrofitted structure. For various performance levels to assess the fragility curves, FEMA global drift limits were compared with the drift limits based on the FEMA member-level criteria. In addition to this, performance levels which were based on additional quantitative limits were also considered and compared with FEMA drift limits.

The continuous and aggressive downscaling of conventional CMOS devices has been driving the vast growth of ICs over the last few decades. As the CMOS downscaling approaches the fundamental limits, novel device architectures such as metallic source/drain Schottky barrier MOSFET (SB-MOSFET) and SB-FinFET are probably needed to further push the ultimate downscaling. The ultimate goal of this thesis is to integrate metallic Ni1-xPtx silicide (x=0~1) source/drain into SB-MOSFET and SB-FinFET, with an emphasis on both material and processing issues related to the integration of Ni1-xPtx silicides towards competitive devices. First, the effects of both carbon (C) and nitrogen (N) on the formation and on the Schottky barrier height (SBH) of NiSi are studied. The presence of both C and N is found to improve the poor thermal stability of NiSi significantly. The present work also explores dopant segregation (DS) using B and As for the NiSi/Si contact system. The effects of C and N implantation into the Si substrate prior to the NiSi formation are examined, and it is found that the presence of C yields positive effects in helping reduce the effective SBH to 0.1-0.2 eV for both conduction polarities. In order to unveil the mechanism of SBH tuning by DS, the variation of specific contact resistivity between silicide and Si substrates by DS is monitored. The formation of a thin interfacial dipole layer at silicide/Si interface is confirmed to be the reason of SBH modification. Second, a systematic experimental study is performed for Ni1-xPtx silicide (x=0~1) films aiming at the integration into SB-MOSFET. A distinct behavior is found for the formation of Ni silicide films. Epitaxially aligned NiSi2-y films readily grow and exhibit extraordinary morphological stability up to 800 oC when the thickness of deposited Ni (tNi) <4 nm. Polycrystalline NiSi films form and tend to agglomerate at lower temperatures for thinner films for tNi≥4 nm. Such a distinct annealing behavior is absent for the formation of Pt silicide films with all thicknesses of deposited Pt. The addition of Pt into Ni supports the above observations. Surface energy is discussed as the cause responsible for the distinct behavior in phase formation and morphological stability. Finally, three different Ni-SALICIDE schemes towards a controllable NiSi-based metallic source/drain process without severe lateral encroachment of NiSi are carried out. All of them are found to be effective in controlling the lateral encroachment. Combined with DS technology, both n- and p-types of NiSi source/drain SB-MOSFETs with excellent performance are fabricated successfully. By using the reproducible sidewall transfer lithography (STL) technology developed at KTH, PtSi source/drain SB-FinFET is also realized in this thesis. With As DS, the characteristics of PtSi source/drain SB-FinFET are transformed from p-type to n-type. This thesis work places Ni1-xPtx (x=0~1) silicides SB-MOSFETs as a competitive candidate for future CMOS technology. / QC20100708 / NEMO, NANOSIL, SINANO

A new shallow junction formation process, based on selective silicon etching followed by selective growth of in situ B-doped SiGe, is presented. The approach is advantageous compared to conventional ion implantation followed by thermal activation, because perfectly abrupt, low resistivity junctions of arbitrary depth can be obtained. In B-doped SiGe layers, the active doping concentration can exceed the solid solubility in silicon because of strain compensation. In addition, the compressive strain induced in the Si channel can improve drivability through increased hole mobility. The process is integrated by performing the selective etching and the selective SiGe growth in the same reactor. The main advantage of this is that the delicate gate oxide is preserved. The silicon etching process (based on HCl) is shown to be highly selective over SiO2 and anisotropic, exhibiting the densely packed (100), (311) and (111) surfaces. It was found that the process temperature should be confined between 800 ºC, where etch pits occur, and 1000 ºC, where the masking oxide is attacked. B-doped SiGe layers with a resistivity of 5×10-4 Ωcm were obtained. Well-behaved pMOS transistors are presented, yet with low layer quality. Therefore integration issues related to the epitaxial growth, such as selectivity, loading effect, pile-up and defect generation, were investigated. Surface damage originating from reactive-ion etching of the sidewall spacer and nitride residues from LOCOS formation were found to degrade the quality of the SiGe layer. Various remedies are discussed. Nevertheless, high-quality selective epitaxial growth could not be achieved with a doping concentration in the 1021 cm-3 range. The maximum doping level resulting in a high-quality layer, with the loading effect taken into account, was 6×1020 cm-3. After this careful process optimization, a high-quality layer was obtained in the recessed areas. Finally, Ni mono-germanosilicide was investigated as a material for contact formation to the epitaxial SiGe layers in the recessed source and drain areas. The formation temperature is 550 ºC and it is stable up to 700 ºC. The observation of a recessed step and lateral growth of the silicide led to a detailed treatment of the contact resistivity of the NiSi0.8Ge0.2/Si0.8Ge0.2 interface using 2-D as well as 3-D modeling. Different values were obtained for square shaped and rounded contacts, 5.0x10-8 Ωcm2 and 1.4x10-7 Ωcm2, respectively. / QC 20101028

The effectiveness of seismic retrofitting applied to enhance seismic performance was assessed for a five-story reinforced concrete (RC) flat-slab building structure in the central United States. In addition to this, an assessment of seismic fragility that relates the probability of exceeding a performance level to the earthquake intensity was conducted. The response of the structure was predicted using nonlinear static and dynamic analyses with synthetic ground motion records for the central U.S. region. In addition, two analytical approaches for nonlinear response analysis were compared. FEMA 356 (ASCE 2000) criteria were used to evaluate the seismic performance of the case study building. Two approaches of FEMA 356 were used for seismic evaluation: global-level and member-level using three performance levels (Immediate Occupancy, Life Safety and Collapse Prevention). In addition to these limit states, punching shear drift limits were also considered to establish an upper bound drift capacity limit for collapse prevention. Based on the seismic evaluation results, three possible retrofit techniques were applied to improve the seismic performance of the structure, including addition of shear walls, addition of RC column jackets, and confinement of the column plastic hinge zones using externally bonded steel plates. Finally, fragility relationships were developed for the existing and retrofitted structure using several performance levels. Fragility curves for the retrofitted structure were compared with those for the unretrofitted structure. For various performance levels to assess the fragility curves, FEMA global drift limits were compared with the drift limits based on the FEMA member-level criteria. In addition to this, performance levels which were based on additional quantitative limits were also considered and compared with FEMA drift limits.

<p>A new shallow junction formation process, based on selective silicon etching followed by selective growth of in situ B-doped SiGe, is presented. The approach is advantageous compared to conventional ion implantation followed by thermal activation, because perfectly abrupt, low resistivity junctions of arbitrary depth can be obtained. In B-doped SiGe layers, the active doping concentration can exceed the solid solubility in silicon because of strain compensation. In addition, the compressive strain induced in the Si channel can improve drivability through increased hole mobility. The process is integrated by performing the selective etching and the selective SiGe growth in the same reactor. The main advantage of this is that the delicate gate oxide is preserved. The silicon etching process (based on HCl) is shown to be highly selective over SiO₂ and anisotropic, exhibiting the densely packed (100), (311) and (111) surfaces. It was found that the process temperature should be confined between 800 ºC, where etch pits occur, and 1000 ºC, where the masking oxide is attacked. B-doped SiGe layers with a resistivity of 5×10-⁴ Ωcm were obtained. Well-behaved pMOS transistors are presented, yet with low layer quality. Therefore integration issues related to the epitaxial growth, such as selectivity, loading effect, pile-up and defect generation, were investigated. Surface damage originating from reactive-ion etching of the sidewall spacer and nitride residues from LOCOS formation were found to degrade the quality of the SiGe layer. Various remedies are discussed. Nevertheless, high-quality selective epitaxial growth could not be achieved with a doping concentration in the 1021 cm-3 range. The maximum doping level resulting in a high-quality layer, with the loading effect taken into account, was 6×10²⁰cm-³. After this careful process optimization, a high-quality layer was obtained in the recessed areas. Finally, Ni mono-germanosilicide was investigated as a material for contact formation to the epitaxial SiGe layers in the recessed source and drain areas. The formation temperature is 550 ºC and it is stable up to 700 ºC. The observation of a recessed step and lateral growth of the silicide led to a detailed treatment of the contact resistivity of the NiSi₀.₈Ge_0.2/Si_0.8Ge_0.2 interface using 2-D as well as 3-D modeling. Different values were obtained for square shaped and rounded contacts, 5.0x10^-8 Ωcm² and 1.4x10^-7 Ωcm², respectively.</p>

This thesis comprises three essays on the international movement of merchandise and people. The first essay measures the effects of foreign aid flows on a donor's merchandise exports. On average, donor countries tie approximately 50% of their foreign aid to exports, but the export stimulation of aid may exceed the amount that is directly tied. This essay uses the gravity model of trade to statistically test the link between aid and export expansion. The results suggest that aid is associated with an increase in exports of goods amounting to 120% of the aid. The essay also makes comparisons among donors and finds that Japan, which has drawn harsh criticism for using aid to gain unfair trade advantages, derives less merchandise exports from aid than the average donor. The second essay investigates the effects of immigration on Canada's pattern of trade. I derive three alternative functional forms capturing the relationship between immigration and trade based on the proposition that immigrants use their superior "market intelligence" to exploit new trade opportunities. I then employ province-level trade data with over 150 trading partners to identify immigrant effects and obtain results suggesting that immigrants account for over 10% of Canada's exports. The third essay addresses the question of whether tax differences contribute toward the brain drain from Canada to the U.S. This essay tests whether the U.S.'s lower taxes draw Canadians south by examining a sample of Canadians living in Canada and a sample of Canadians living in the U.S. Using information from these samples I estimate how much these individuals would earn in the opposite country and estimate the taxes they would pay. I find that the people who have the most to gain in income and in tax-savings are the most likely to choose to live in the U.S., and thus corroborate the claim that tax differences contribute toward Canada's brain drain.

Laisvas asmenų judėjimas Europos Sąjungoje suteikia galimybę laisvai pasirinkti darbo bei gyvenimo vietą. Naujosioms Europos Sąjungos narėms, tai reiškia emigracijos augimą. Šis procesas turi neigiamos įtakos šalies ekonomikai, ypač, kai išvyksta kvalifikuoti darbuotojai. Šio darbo objektas Lietuvos, Latvijos ir Slovėnijos politikos sprendimai, susiję su „protų nutekėjimu“. Šiame darbe buvo iškeltas tikslas išanalizuoti Lietuvos, Latvijos bei Slovėnijos situaciją „protų nutekėjimo“ kontekste bei palyginti jų vykdomą politiką šiuo klausimu. Tikslui pasiekti buvo keliami uždaviniai: apžvelgti intelekto migraciją bei jos problemas, išanalizuoti Lietuvos „protų nutekėjimo“ priežastis bei pasekmes, Palyginti Latvijos ir Slovėnijos situaciją „protų nutekėjimo“ klausimu, išanalizavus Lietuvos, Latvijos bei Slovėnijos valstybių vykdomą politiką aukštos kvalifikacijos darbuotojų migracijos mažinimui, pateikti rekomendacijas. Darbe buvo iškelta hipotezė: aiškios politinės programos, nukreiptos į „protų cirkuliaciją“, mažina „protų nutekėjimą“ bei sudaro sąlygas mokslo ir technologijų vystimuisi. Išanalizavus vykdomas politikas „protų nutekėjimo“ klausimu, yra pateikiamos pagrindinės išvados ir rekomendacijos: 1. Lietuvos ir Latvijos mokslinių tyrimų finansavimas yra ne investicinio, o remiamojo pobūdžio, nepakankamas tarptautinis bendradarbiavimas, vakarų Europoje nepakankamai pristatomas Lietuvos mokslo potencialas. Slovėnijoje mokslinių tyrimų finansavimas yra investicinio... [toliau žr. visą tekstą] / Having no borders in the European Union, gives the opportunity to choose the place of work and life. For the new members of EU, it means the increased emigration. This process has negative effects on the economics of the country especially talking about qualified workers. The object of this work is political decisions of Lithuania, Latvia and Slovenia which are related with “brain drain”. The aim of the work is to analyze the situation of Lithuania, Latvia and Slovenia in the content of “brain drain” and compare their political decisions. To reach this aim there were the following goals for this work: to observe the emigration of skilled labour, to analyze the reasons and consequences of Lithuania’s “brain drain” and to give recommendations after comparison of Lithuania, Latvia and Slovenia’s policies of reducing “brain drain”. The hypothesis of this work was: clear political programs directed towards “brain circulation” reduces “brain drain” provides conditions for the development of science and technologies. After analysis of the pursued politics of “brain drain” there are given some findings and recommendations: 1. Lithuania and Latvia’s scientific research is non investment character but supportive, too weak international collaboration, Lithuania’s research is not presented in the west well enough. In Slovenia science is based on business investment which stimulates competitiveness and development of economics. 2. Lithuania, and Latvia’s MTTP human resources are not... [to full text]