No abstract

Predicting the amount of solar radiation that strikes a surface is of the highest importance in several engineering applications. Just to name a few, solar radiation estimates is fundamental during the design of technologies such as: flat plates and concentrating collectors, solar energy storage devices, solar heaters, and photovoltaic systems. Furthermore, solar radiation estimates are important in energy studies for buildings, as during the cooling load calculation for air conditioning systems. The calculation of the solar radiation and shading involves many equations and a lot of influencing factors must be considered. Therefore, a Matlab GUI was developed that execute the equations and considers all the influencing factors. The program calculates the solar radiation and shadows caused by a rectangle as well as shadows on a rectangle surface caused by fins beside it. The user only has to set few values (like the location, time, etc.) and he can choose between the calculations either for a selectable time of the day or for a completely day. Then the results are plotted either in simple editor frames or in 2D-and 3D-graphics. The program also shows the results of some influencing angles subject to the location of the sun in the sky that can be helpful for many applications. Finally, on the educational side, the Matlab program can be useful for the engineering student performing some what if studies involving solar radiation.

No abstract

-This work contains a novel approach for the study of stability in fluidized systems. It includes the influence of solid particle kinetic energy variations, which are known as granular temperature. The stability is verified by the temporal evolution of bed fluid-dynamics properties (solid volumetric fraction, fluid velocity, solid particles velocity) after small perturbations. The bed is stable when the amplitudes of perturbations decrease with time. The work departs from the mass and momentum continuity equations for the solid and fluid phase, as proposed by Anderson and Jackson (1968). Those are complemented by an equation describing the energy balance from the point of view of granular temperature. Then, a linear approximation for the equations after the introduction of small magnitude perturbations is obtained. The application of harmonic solutions allows arriving to the temporal description of the perturbations. Results show the occurrence of instabilities on the direction transverse to gravity. This cannot be observed by previous approaches Jackson, 1968, 1969;Homsy et al., 1980;Liu, 1982). The present work also suggests a new mechanism for the formation of bubbles in fluidized systems. The parametric influence of the model on the stability of fluidized systems is also verified.

Neste texto busca-se colocar em evidência a trajetória de criação do Núcleo de Prática Jurídica da Faculdadede Direito da Universidade de Brasília. Para tanto, foram trabalhados conceitos e experiências que permearama implementação das novas diretrizes curriculares e o papel da integração entre ensino, pesquisa e extensão.Entre eles o Direito Achado na Rua, o Núcleo para Paz e Direitos Humanos e a luta por direitos desenvolvidana Vila Telebrasília. Por meio do estudo deste caso, demonstrou-se a indissociabilidade entre teoria e práticae como o direito pode ser compreendido como a legítima organização social da liberdade. O direito seconstrói e reconstrói no seio da sociedade, nas lutas dos movimentos sociais, nos espaços públicos ondecidadãos dotados de autonomia pública e privada vivem sua autolegislação: na rua. Assim, o conhecimentojurídico deve abrir-se de forma transdisciplinar a outras áreas, compreendendo a complexidade social erompendo com a compartimentarização dos saberes. São necessários conhecimentos cada vez mais amplos para lidar com os novos problemas sociais.