The topic of presented diploma thesis is study of thermal properties structures of photovoltaic cells. The main goal of this thesis is study of ways of heat spreading from volume and planar materials (conduction, convection and radiation). Then it is needed to determine contributions of heat spread from laminated photovoltaic cell and compare them to results measured by transient pulse method, step wise method and with thermo-camera using. At the beginning of this thesis it will be needed to define heat and ways it’s spread. Heat is closely connected with temperature. That is reason why will be there spoken about temperature and methods of its measuring. Than there will be defined basic thermo-physical parameters of materials. Thermo-physical parameters of materials will be measured by transient methods that will be characterized later and by thermo-camera. This thesis deals with photovoltaic cells, so there will be described their structure, properties, utilization and way of their production. Subsequently after the definition of all needed terms the experimental part of this thesis will be introduced. It will be needed to characterize measured volume material and define its thermo-physical parameters. Using the pulse transient method, step wise method and thermo-camera there will be measured the thermal response of PMMA sample, nonlaminated photovoltaic cell and also samples of laminated photovoltaic cells. Findings of all described methods will be finally compared.

Made available in DSpace on 2015-03-03T15:15:22Z (GMT). No. of bitstreams: 1 SanziaAN.pdf: 964619 bytes, checksum: 25b161330259b5777dcaa8cf03c1242b (MD5) Previous issue date: 2008-04-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / ROTATION is one the most important aspects to be observed in stellar astrophysics. Here we investigate that particularly in stars with planets. This physical parameter supplies information about the distribution of angular momentum in the planetary system, as well as its role on the control of dierent phenomena, including coronal and cromospherical emission and on the ones due of tidal effects. In spite of the continuous solid advances made on the study of the characteristics and properties of planet host stars, the main features of their rotational behavior is are not well established yet. In this context, the present work brings an unprecedented study about the rotation and angular momentum of planet-harbouring stars, as well as the correlation between rotation and stellar and planetary physical properties. Our analysis is based on a sample of 232 extrasolar planets, orbiting 196 stars of dierent luminosity classes and spectral types. In addition to the study of their rotational behavior, the behavior of the physical properties of stars and their orbiting planets was also analyzed, including stellar mass and metallicity, as well as the planetary orbital parameters. As main results we can underline that the rotation of stars with planets present two clear features: stars with Tef lower than about 6000 K have slower rotations, while among stars with Tef > 6000 K we and moderate and fast rotations, though there are a few exceptions. We also show that stars with planets follow mostly the Krafts law, namely < J > / v rot. In this same idea we show that the rotation versus age relation of stars with planets follows, at least qualitatively, the Skumanich and Pace & Pasquini laws. The relation rotation versus orbital period also points for a very interesting result, with planet-harbouring stars with shorter orbital periods present rather enhanced rotation / ROTA??O ? um dos importantes aspectos a ser observado na astrof?sica estelar. Por isto, neste trabalho, investigamos este par?metro no estudo das estrelas hospedeiras de planetas. Par?metro f?sico este que fornece informa??o sobre a distribui??o do momentum angular dos sistemas planet?rios, bem como sobre o seu papel nos mais diferentes fen?menos, incluindo emiss?o cromosf?rica e coronal e sobre aqueles decorrentes de efeitos de mar?. Apesar dos cont?nuos avan?os feitos no estudo das caracter?sticas e das propriedades destes objetos, as principais caracter?sticas de seu comportamento rotat?rio ainda n?o est?o bem estabelecidas. Neste contexto, o presente trabalho traz um estudo pioneiro sobre a rota??o e o momentum angular das estrelas hospedeiras de planetas, bem como sobre a correla??o entre rota??o e par?metros f?sicos estelares e planet?rios. Nossa an?lise ? baseada em uma amostra de 232 planetas extrasolares, orbitando 196 estrelas de diferentes classes de luminosidade e tipos espectrais. Al?m do estudo do comportamento rotacional dessas estrelas, re-visitamos o comportamento das propriedades f?sicas destas estrelas e de seus planetas, incluindo a massa estelar e a metalicidade, bem como os par?metros orbitais planet?rios. Como resultados principais, podemos sublinhar que a rota??o das estrelas com planetas apresenta duas claras caracter?sticas: estrelas com Tef inferiores aproximadamente 6000 K possuem rota??es mais baixas, enquanto que entre aquelas com Tef > 6000 K encontramos rota??es modv eradas e altas, embora algumas exce??es. N?s mostramos tamb?m que as estrelas com planetas seguem, em sua maioria, a lei do Kraft, a saber < J > / v rot. Nesta mesma linha n?s mostramos que a rela??o rota??o versus idade das estrelas com planetas segue, ao menos qualitativamente, como qualquer outra estrela de campo ou de aglomerado, a lei de Skumanich e de Pace & Pasquini. Um resultado interessante a ser destacado ? a rela??o rota??o versus per?odo orbital, que aponta para uma tend?ncia de que as estrelas que abrigam planetas com per?odo orbital menores apresentam rota??es mais real?adas