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As células a combustível são dispositivos eletroquímicos que produzem energia elétrica limpa. Entretanto, o seu uso em larga escala ainda é limitado devido às enormes perdas de potencial que ocorrem no cátodo em função da lenta cinética da reação de redução de oxigênio (RRO). Portanto, é necessário o desenvolvimento de novos catalisadores que sejam viáveis comercialmente, apresentem alta atividade eletrocatalítica e grande estabilidade para esta reação. Neste trabalho, a RRO foi estuda em meio ácido em eletrocatalisadores à base de platina suportadas em carbetos de tungstênio (WC) e molibdênio (MoC) com diferentes estruturas cristalinas. Os carbetos foram preparados pelos métodos de decomposição térmica (MDT) e carburação (MC) e, subsequentemente, utilizados para a preparação dos catalisadores do tipo Pt-carbeto pelo método do ácido fórmico ou borohidreto de sódio. Estes materiais foram caracterizados por difração de raios-X (XRD), espectroscopia de energia dispersiva de raios-X (EDX), microscopia eletrônica de transmissão (TEM), espectroscopia de absorção de raios-X (XAS) in situ e espectroscopia de fotoelétrons excitados por raios-X (XPS). As medidas eletroquímicas foram realizadas em meio ácido usando a técnica de eletrodo disco-anel rotativo de camada fina. Os resultados de XRD, em conjunto com as medidas de TEM, indicaram que o MDT e MC fornecem carbetos com estruturas cúbicas (&beta;-WC1-x e &delta;-MoC) e hexagonais (&alpha;-WC e &alpha;-Mo2C) com tamanho de partícula < 2 nm e entre 10 e 40 nm, respectivamente. Os estudos eletroquímicos evidenciaram que os catalisadores Pt-carbeto/C apresentam diferenças de atividade específica (SA) e mássica (MA) para a RRO em função da estrutura e composição e que todos os catalisadores do tipo Pt-&beta;-WC1-x/C, Pt- &alpha;-Mo2C/C e Pt-&delta;-MoC/C e Pt2Ni- &alpha;-WC/C apresentam maior SA em comparação à Pt/C. A concentração de carbeto na matriz de carbono também influenciou significativamente os valores de SA, porém não há uma tendência clara que permita unificar um efeito comum para todos os catalisadores. Dentre todos estes catalisadores, o Pt-&beta;-WC1-x40/C e o Pt-&delta;-MoC40/C são 3,6 e 2,5 vezes mais ativos (SA) em comparação ao catalisador Pt/C. Também foi observado que a via predominante da RRO envolve cerca de 4 elétrons por molécula de oxigênio, com baixa produção de H2O2 em todos os casos. No caso dos materiais baseados em Pt-&beta;-WC1-x/C, análises de XANES in situ mostraram um pequeno aumento na ocupação da banda 5d da Pt, o que deve levar a uma interação Pt-OHx mais fraca, aumentando a cinética da RRO como observado. Além disso, os resultados de XPS evidenciam que a melhora na atividade específica está relacionada a um efeito sinérgico entre Pt ou Pt2Ni com as espécies do tipo WOx ou MoOx; exceto para os catalisadores de ligas Pt2Ni, para o qual os resultados de XPS indicaram a presença de WC na superfície do catalisador. Os testes de estabilidade mostraram que apesar do Pt/C ser mais ativo após 12.000 ciclos, o catalisador Pt-&alpha;-WC20/C é o mais estável em relação a sua AS, indicando que as interações benéficas das fases remanescente de Pt e WC/WOx são mantidas após o teste de durabilidade. / Fuel cells are electrochemical devices that produce clean electrical energy. However, their use on large scale is still limited due to the enormous potential losses that occur at the cathode due the slow kinetics of the oxygen reduction reaction (ORR). Therefore, the development of new catalysts that are commercially viable, present high electrocatalytic activity and great stability for this reaction is still necessary. In this work, the ORR was studied in acid medium on platinum-based electrocatalysts supported on tungsten (WC) and molybdenum (MoC) carbides with different crystalline structures. Carbides were prepared by the thermal decomposition (TDM) and a carburizing (CM) methodes and, subsequently used for the preparation of the Pt-carbide type catalysts by the formic acid or sodium borohydride method. These materials were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS). The electrochemical measurements were performed in acid medium using the thin-layer rotating disk-ring electrode technique. The results of XRD, together with those of TEM, indicate that the MDT and MC provide carbides with cubic (&beta;-WC1-x and &delta;-MoC) and hexagonal ( &alpha;-WC and &alpha;-Mo2C) structures with particle size < 2 nm and between 10 and 40 nm, respectively. The Pt-carbide/C catalysts exhibit differences in the specific activity (SA) and mass (MA) for the ORR as a function of structure and composition. All catalysts of the types Pt-&beta;-WC1-x/C, Pt- &alpha;-Mo2C/C, Pt-&delta;-MoC/C and Pt2Ni- &alpha;-WC/C presented higher SA as compared to Pt/C. The concentration of carbide in the carbon matrix significantly influence the SA, but no tendency was clearly found so to identify a common effect catalysts overall. Among all catalysts, Pt-&beta;-WC1-x40/C and Pt-&delta;-MoC40/C are 3.6 and 2.5 times more active (SA) compared to the Pt/C catalyst. It was also observed that the predominant ORR mechanism involve &cong; 4 electrons per oxygen molecule, and so with negligible production of H2O2. In the case of the materials based on Pt-&beta;-WC1-x/C, in situ XANES analyzes evidenced a small increase in the Pt 5d-band, occupancy leading to a weaker Pt-OHx interaction, increasing ORR kinetics as observed. In addition, XPS results show that the improvement in SA is related to a synergistic effect between Pt or Pt2Ni with WOx or MoOx species, except for the Pt2Ni alloy catalysts, for which the XPS results indicated the presence of some WC on the catalyst surface. Stability tests show that although Pt/C is more active after 12,000 cycles, the Pt-&alpha;-WC20/C catalyst is the most stable relative to its SA, indicating that the beneficial interactions of the remaining phases of Pt and WC/WOx are maintained after the durability test.

Η τεχνική FUE είναι μια ελάχιστα επεμβατική μέθοδος μεταμόσχευσης μαλλιών η οποία χρησιμοποιείται από πολλούς ιατρούς τα τελευταία 10 χρόνια. Ο σκοπός της εργασίας αυτής είναι η εφαρμογή μεθόδων μαθηματικής μοντελοποίησης με ώστε να περιγράψει τα κυριότερα τμήματα της μεταμόσχευσης μαλλιών, ποσοτικοποιώντας πολύ σημαντικά θέματα όπως το τραύμα της δότριας ζώνης,το πρόβλημα της ασφαλούς και με ακρίβεια εξαγωγής των τριχοθυλακιων,την άριστη κατανομή και την λεπτομερή εκτίμηση και επίτευξη της πυκνότητας της λήπτριας περιοχής. Για τους προαναφερθέντες λόγους, ψηφιακές μικροφωτογραφίες από την δότρια και λήπτρια περιοχή αναλύθηκαν με επεξεργασία εικόνας, η οποία βασίστηκε σε ειδικούς μαθηματικούς αλγορίθμους που αναπτύχθηκαν κατά τη διάρκεια αυτής της μελέτης. Τέλος ένα ολοκληρωμένο πλάνο θεραπείας προτείνεται από τον συγγραφέα για περιπτώσεις μεταμόσχευσης μαλλιών που αντιμετωπίζονται με την τεχνική FUE. / The FUE technique is a minimally invasive hair transplantation method, which has been used by many Doctors over the last 10 years. The aim of this study is mathematical principles to be applied in order to describe the major steps of the hair transplantation, quantitating very important issues like the trauma in the donor area, the problem of safe and accurate extraction of the follicular units, the optimal distribution and the precise estimation and achievement of the recipient area density. For the fore mentioned reasons digital micropictures from donor and recipient area were analyzed by using image processing which was based on special mathematical algorithms which were developed during this study. Finally an integrated treatment planning program is proposed by the Author for hair transplantation cases which are treated by using FUE technique.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / With explosive growth in the satellite communication market. there is an increasing need for the satellite network service providers to support many satellites with a common Telemetry, Tracking, and Commanding (TT&C) assets. The open bus technology, and Commercial Off The Shelf (COTS) Hardware and Software components, provides an opportunity to build a common IF and baseband systems that will support many satellites with different frequencies and protocols. However, the high frequency front end components of the ground station such as antenna or HPA can not be common due to different gain and polarization requirements of the various communication bands and frequencies. The system architecture presented in this paper offers such system that is interoperable and reconfigurable in near real-time to support multiple frequency and multiple communication protocols.

Diese Dissertation besteht aus drei unabhängigen Kapiteln über mikroökonomische Themen. Die ersten beiden Kapitel befassen sich mit Themen der Industriökonomie und Wettbewerbstheorie, wohingegen das dritte Kapitel Fragestellungen von Cheap Talk Spielen untersucht. Kapitel 1 untersucht die Folgen, die sich aus einer partiellen Akquisition zwischen Wettbewerbern ergeben. Kapitel 2 analysiert die Auswirkungen einer Forschungs-und Entwicklungs (FuE)- Kooperation auf die Investitionsanreize in einem Markt, in dem eine Mehrproduktunternehmer mit einem Einzelproduktuntfirma konkurriert. Kapitel 3 untersucht die Funktion der Mediation zur Erleichterung der Kommunikation mit privaten Informationen. / This dissertation consists of three independent chapters in the field of microeconomics. The first two chapters are concerned with topics of industrial organization and competition policy, whereas the third chapter addresses some problems in cheap talk games. Chapter 1 studies anti-competitive issues that arise from partial acquisition between competitors. Chapter 2 analyzes the effects of cooperation on R&D investment incentives in a market where a multi-product firm competes with a single-product firm. The third chapter examines the role of mediation in facilitating communication with private information.

[pt] Em um primeiro momento a palavra cangaço pode direcionar nosso pensamento aos estudos da História, da Sociologia e da Antropologia. Isso porque, dentre os mais variados estudos científicos sobre o tema, a maior parte de sua produção se dá no âmbito dessas ciências. Não obstante o imenso valor da análise da atuação do cangaço para os mencionados campos de estudo, há uma relevância extraordinária do tema para a ciência jurídica, chegando ao nível de ser alvo de discussões e proposições de emendas durante os trabalhos da Constituinte de 1933/1934, muito embora as propostas tenham ficado de fora do texto final da nova Constituição. O avanço do cangaço na região Nordeste do país, aliado às falhas no sistema de segurança pública e à ausência prestacional do Estado, fizeram com que o banditismo no sertão se expandisse e tornasse uma preocupação nacional. É no período do Governo de Getúlio Vargas que o combate ao cangaço irá se intensificar, e a morte de Lampião, seu principal líder, trará como consequência a desarticulação e extinção do movimento. / [es] En un principio, la palabra cangaço puede orientar nuestro pensamiento a los estudios de Historia, Sociología y Antropología. Esto se debe a que, entre los más variados estudios científicos sobre el tema, la mayor parte de su producción se da en el ámbito de estas ciencias. A pesar del inmenso valor del análisis de la actuación del cangaço para los campos de estudio mencionados, hay una extraordinaria relevancia del tema para la ciencia jurídica, llegando al nivel de ser objeto de discusiones y propuestas de enmiendas durante los trabajos de la Constituyente de 1933/1934, aunque las propuestas quedaron fuera del texto final de la nueva Constitución. El avance del cangaço en la región Nordeste del país, aliado a las fallas en el sistema de seguridad pública y la ausencia de beneficios del Estado, hizo que el bandolerismo en el sertão se convirtiera en una preocupación nacional. Es en el período del gobierno de Getúlio Vargas que la lucha contra el cangaço se intensificará, y la muerte de Lampião, su principal líder, traerá como consecuencia la extinción del movimiento.

No description available.

Die Studie wird in fünf Teile unterteilt: Das erste Kapitel beschäftigt sich mit Patentanmeldungen und geförderten Patenten im USPTO, WIPO, und EPO. In diesem Kapitel wird die Korrelation zwischen dem BIP und der länderspezifischen Patentanzahl analysiert. Das zweite Kapitel gibt einen Überblick über die Literatur über Patente in MEDLINE. In diesem Kapitel wird eine szientometrische Analyse durchgeführt, damit die Entwicklung der Patentliteratur in MEDLINE über den Zeitraum von 1965 bis 2005 quantitativ gemessen werden kann. Das dritte Kapitel befasst sich mit der Literatur über Patente im SCI. In diesem Kapitel werden alle Dokumente, die vom SCI über den Zeitraum 1965 bis 2005 als “Patents“ indexiert wurden, unter die Lupe genommen. Das vierte Kapitel analysiert die Patenten, die im SCI zitiert werden. Das fünfte Kapitel analysiert die Anzahl der Literaturhinweise (Referenzen) pro Veröffentlichung im SCI über den Zeitraum 1970-2005. In diesem Hinblick wurde eine Gesamtzahl von 10,000 Dokumenten pro Jahr ausgesucht sowie der Bedeutungswert von Nennungen pro Zeitschrift berechnet. Die Analyse der Daten ergab: Die USA sind das führende Land bezüglich der Erstellung und der Zulassung von Patenten, gleichermaßen gefolgt von Japan und Deutschland. Die Halbwertszeit der Zitierung von Patenten beträgt seit 1994 konstant 8,1 Jahre. Das ist eine 41% längere Zitierungsrate gegenüber den allgemeinen wissenschaftlichen Dokumenten im SCI. Es gibt eine lineare Korrelation zwischen der Zahl von Literaturhinweisen (Referenzen) in einem Journal, wie sie im SCI erfasst sind, und der Wahrscheinlichkeit zitiert zu werden. Die Anzahl der Literaturhinweise (Referenzen) pro Veröffentlichung zwischen 1970 und 2005 im SCI ist ständig angestiegen. Die Selbstzitation von Zeitschriften bei einer steigenden Zahl von Verweisen beeinflusst die Steigerung des Impact Factor im SCI. Die Leitartikelpolitik der Sprachen wurde in der MEDLINE und im SCI geändert. / This study is divided into five sections. The first section consists of patent applications and granted patents issued by USPTO, WIPO), and EPO. In this section the relationship between the GDP and country’s patent quantity is analysed. The second section analysis the patent literature in MEDLINE. In this section a scientometric analysis is performed to assess the quantitative trend of patent literature in MEDLINE throughout 1965-2005. The third section analysis the patent literature in the SCI. In this section all documents indexed as a topic of “patents” in the SCI throughout 1965-2005 are analysed. The fourth section analysis the citations to the patent documents indexed in the SCI, and illustrate the average number of cited references per paper for patent citing documents. The fifth section analysis the references per paper in the SCI through 1970-2005. The Analyses of data showed: The USA is the leading country filing and granting patents followed by Japan and Germany respectively. The half-life of citations to the patent-documents is 41% higher than the half-life of citations to the general scientific documents in the SCI. The number of references per paper from 1970 to 2005 has steadily increased. The rough constant percentage of self-citation of journals and the growing increase of references per paper led to the absolute growing number of self-citations and to the increase of the Impact Factor of the citing journals in the SCI. The editorial policy of languages is being changed in MEDLINE and in the SCI. The consideration of policy makers in these databases have been focused on the literature of science in English. There was a tendency in the last decades towards collaboration in scientific publishing with American authors that can be observed in the SCI with authors from different countries.

This thesis concentrates on literary works written by writers belonging to the resident Korean minority in Japan (zainichi Koreans). Through the use of postcolonial methodology, this work attempts to monitor the development and changes in the complex concept of "identity" in works written between the 1960s and 2010. The thesis is divided into two major parts. The first, theoretical part, explains the birth of the minority, the conflicts that influenced it and the changes it went through during its history. Postcolonial methodology is also explained, with focus put on the parts that are relevant to Japan. The second, practical part of the thesis, shortly explains the history of zainichi literature and then concentrates on five important postwar resident Korean writers - Ri Kaisei, Kin Kakuei, Yi Yang-ji, Kaneshiro Kazuki and Yu Miri. It analyzes between one and four works by each author and attempts to identify changes in the perception of "identity". It also takes into account female characters and the way they are portrayed by the authors and also the language the book is written in, focusing on whether the author chooses to incorporate the Korean language into the text.