Made available in DSpace on 2014-06-11T19:25:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-04Bitstream added on 2014-06-13T19:12:15Z : No. of bitstreams: 1 carvalho_jps_me_guara.pdf: 1120789 bytes, checksum: 42d7f707a41ef83886b116f000a33c22 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Uma teoria para estudar o movimento orbital de satélites artificiais sobre efeitos do arrasto atmosférico e da pressão de radiação solar direta - considerando a sombra da Terrae alguns termos do geopotencial - é desenvolvida analiticamente. A sombra daTerra é modelada utilizando a função sombra, como introduzida por ferraz Mello: igual zero quando o satélite está na região de sombra e igual um quando é iluminado pelo sol. As componentes do arrasto são dadas por Vilhena de Moraes baseado no modelo atmosférico TD-88. O método de Hori para sistemas não canônicos é aplicado para resolver as equações de movimento. Um software para manipulação algébrica é fundamental apra fazer os cálculos necessários. Efeitos seculares e periódicos que influenciam no movimento orbital dos satélites artificiais são analisados. Expressões analíticas são apresentada explicitamente para os principais termos seculares nas variações dos elementos orbitais. É dada ênfase aos termos de acoplamento que surgem na solução do sistema de equações diferenciais. Utilizando dados orbitais do satélite CBERS-1 um estudo é feito para analisar ordens da variação do semi-eixo maior devidas as pertubações consideradas. / A theory to study the orbital motion of artificial satellites under the effects of the atmospheric drag and of the direct solar radiatin pressure - considering the Earh's shadow and some terms of the geopotential - is developed analytically. The Earth shadow is modeled using the shadow function introduced by Ferrz Mello: equal zero when the satellite is in the shadow region and equal one when it is illuminated by the Sun. The drag components are given by Vilhena of Moraes based in the TD-88 temospheric model. The Hori's method for non-canonical systems is applied to solve the motion equation. A algebric manipulator software is fundamental to do the necessary calculations. Secular and periodic effects on the orbital motion of artificial satellites are analyzed. Analytic expressions are presented explicity for the main secular terms of the variations of the orbital elements. Emphasis is given to the coupling terms that appear in the solution of the differential euqatin systems. Using orbital data of the satellite CBERS-1 a study is done to analyze the order of magnitude of the variation of the semi-major axis due to the considered pertubation.

Made available in DSpace on 2014-06-11T19:31:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-02Bitstream added on 2014-06-13T19:02:04Z : No. of bitstreams: 1 scolar_j_dr_botfca.pdf: 1328254 bytes, checksum: ee3f5f1ff4f7b0c84f4f5bffe942ecb7 (MD5) / Neste trabalho, realizou-se um estudo de modelagem da irradiação total que incide sobre uma superfície inclinada, com face voltada para o Equador, e com inclinação de 22,85º, igual a da latitude local. Foram testados 7 modelos, existentes na literatura, utilizando partição diária de energia. Os modelos de Temps & Coulson, Klucher e circunsolar, apresentam os piores desempenhos e não devem ser utilizados na estimativa da irradiação total diária em Botucatu, por outro lado os modelos de Liu & Jordan, Hay, Perez et al. e Reindl et al., são similares entre si, e apresentam boa concordância quando comparados com os dados observacionais, sendo o modelo de Hay ligeiramente superior aos outros. O propósito deste trabalho é obter um modelo que utilize somente a irradiação global medida na superfície horizontal para estimar a irradiação total na superfície inclinada. Para tanto, os modelos de estimativa foram modificados de duas maneiras diferentes. Na primeira, a irradiação difusa foi estimada em função da irradiação global, através do ajuste empírico utilizando a técnica de regressão linear, na forma Kd = f (Kt) , fração da difusa contida na global (Kd ), com o índice de claridade (Kt ), nesse caso, o melhor ajuste é dado por um polinômio de 4º grau Kd = 0,993 + 0,178Kt - 0,945Kt2 - 4,712Kt3 + 4,891Kt4 . Na Segunda modificação, a irradiação direta KBH , fração da irradiação direta contida na irradiação global, foi ajustada através da técnica de regressão linear, em função do índice de claridade, na forma KBH = f (Kt ) , nesse caso o melhor ajuste foi linear, obtido para intervalos específicos de Kt , KBH = 0 para Kt £ 0,25 , e KBH = -0,386 +1,572Kt para Kt >0,25. Os resultados obtidos com essas modificações mostram que os modelos têm melhores... / A modelling study of the total irradiation reaching a tilted surface facing towards the equator at tilt same of local latitude of 22,85º,, is presented. In this study seven total irradiation incident on a tilted surface estimate models were tested and compared among them, using the daily partitioning energy. Temps & Coulson, Klucher and circumsolar models showed very poor results, and it is suggested that they should not be used to estimate the daily total irradiation for the Botucatu region. On the other hand the Liu & Jordan, Hay, Perez et al. and Reindl et al. models have shown similar performance and presented a good agreement with the observational data. The Hay model however produced better irradiation estimates. The aim of this study is examine and improved irradiation estimative model for tilted surface knowing only the global irradiation measured at horizontal surface. In order to achieve this, two modifications were made on those models mentioned above. The first modification consisted to apply empirical functions to determine the diffuse irradiation by the global radiation measurements. These empirical functions were tuned using the regression linear thecnique, the fraction of the diffuse irradiation (Kd ) from the global irradiation, was correlationed with the clearness index (Kt ). In this case the highest correlation found was, Kd = 0,993 + 0,178Kt - 0,945Kt2 - 4,712Kt3 + 4,891Kt4 a fourth order polynomial function. In the second modification the fraction of the direct irradiation KBH from the global irradiation was correlationed assuming a linear correlation at given intervals of Kt : KBH = 0 for Kt £ 0,25 , and KBH = -0,386 + 1,572Kt for Kt >0,25 otherwise. Model results showed the empirical relationship KBH = f (Kt ) , present better results and the Hay model presented a better performance compared with others models for the... (Complete abstract, click electronic address below)

Recent studies of heterothermy in free-ranging mammals have revealed that solar radiation is an important variable influencing torpor patterns. The interaction between solar radiation (SR) and arousal costs can be thought of as a continuum from passive increases in body temperature (Tb) (rewarming at a slower rate but energetically less costly), to supplementation of endogenous heat production (rewarming more rapidly but with costs similar to that in the absence of solar radiation). To better understand the importance of solar radiation I experimentally manipulated its availability for E. myurus rewarming from torpor under natural conditions of air temperature and photoperiod. Tb was recorded for E. myurus housed in deep shade (20 % SR), partial shade (40% SR) or full sun (100% SR), and torpor frequency, rewarming rates, minimum body temperature, torpor bout duration and heterothermy index compared among treatments. Animals in unshaded cages rewarmed more rapidly than individuals in partially shaded cages. Torpor bouts were less frequent, but overall levels of heterothermy were higher in E. myurus receiving natural solar radiation compared to those in partially shaded treatments. This study, as far as I am aware, is the first demonstrating that solar heat gain, separated from the effects of an increase in ambient temperature (Ta), plays an important role in torpor arousal. Taken with the direct evidence for elephant shrews basking while rewarming, this demonstrates that animals in the unshaded treatment used solar radiation to supplement, rather than replace, endogenous metabolic thermogenesis. It is clear that E. myurus does not necessarily depend on solar radiation for rewarming, but will take advantage of this resource if available, primarily by reducing time taken to rewarm. / Dissertation (MSc)--University of Pretoria, 2014. / lk2014 / Zoology and Entomology / MSc / Unrestricted

The possibility of using sunlight to pump a CW carbon dioxide laser has been analyzed. Such a laser could be of interest for such applications as space communication and power transmission. In order to optically pump CO2 using sunlight, the intense vibrational-rotational absorption bands of CO2 in the 4.3 micron spectral region would have to be utilized. The total pumping power from sunlight can be calculated from the known data of the solar spectral irradiance outside the atmosphere and the infrared absorption by carbon dioxide at 4.3 microns. The pumping power is proportional to the collector area of the sunlight and is also dependent on the characteristics of the absorbing gas mixture, such as the gas composition, the gas temperature, the total pressure of the mixture, the partial pressure of CO2, and the absorption path length of the sunlight in the gas. To analyze the carbon dioxide laser system, a thermodynamic approach was used with a simplified CO2 chemical kinetic model. The gain and saturation intensity were obtained by solving a set of energy balance equations which describe the processes among the various vibrational modes. From those results, along with the estimated cavity losses, the output power was found.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18523号 / 農博第2080号 / 新制||農||1026(附属図書館) / 学位論文||H26||N4867(農学部図書室) / 31409 / 京都大学大学院農学研究科農学専攻 / (主査)教授 白岩 立彦, 教授 奥本 裕, 教授 稲村 達也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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Page 7 was mistyped as being page 8. All content present is in logical order. / A simple method for computing the effect of atmospheric aerosol on the net solar radiation balance of the surface-lower atmosphere system is presented. It was found that in clear sky conditions at Goose Bay, Toronto and Winnipeg, for the period 1977 -1982, the presence of aerosol made the systems 10 -20% more efficient at absorbing radiation than if the aerosol was absent. Furthermore, surface albedo is shown to be the most important parameter governing the effect of aerosol on the net solar radiation balance in an aerosol system, while the effect of volcanic aerosol produced by El Chichon had a minor influence on the net solar radiation balance. / Thesis / Bachelor of Science (BSc)

<p> Monthly median and annual mean values of optical depth and the ratio of diffuse to direct solar radiation for 1981-1983 were calculated using integrated values of global and diffuse radiation and calculations of precipitable water, under cloudless conditions. Results indicate that El Chichon's volcanic dust cloud has affected turbidity over southern Ontario. This is reflected in an increase in optical depth and the ratio of diffuse to direct solar radiation. </p> / Thesis / Bachelor of Arts (BA)

In his book Ritual House, Ralph Knowles states, "The houses we inhabit, the cities surrounding our houses, even the clothes we wear - all are shelters we erect against the elements. But they are also manifestations of ancient rituals, developed in response to nature's rhythms" (2006). Implicit within this quote is the importance of nature's rhythms in our lives, particularly those related to the movement of the sun. Many built environments have no connection to the exterior. Those who work in these spaces are disconnected from these natural rhythms and often experience detrimental physiological effects. However, technology has the potential to reintroduce aspects of natural rhythms into built environments. This research crossed disciplinary boundaries separating architecture, engineering, psychology, and building science during the design of an architectural intervention for an interior workspace known as the Sandbox, at Virginia Tech. The design proposal includes skylights that combine Photovoltaic-integrated glazing with LED lighting to create conditions that stimulate the occupants while connecting inside to out. To reestablish a connection to natural rhythms the BIPV energy monitoring is used during the day to record variations in solar radiation which at night are played back through intensity and color variations of LED lighting. The effect of the LED lighting was compared with the sunlight entering through the skylights using quantitative analysis methods and qualitative visual comparison tools including time lapse photos and videos. The research merges architectural design, lighting technology and BIPV to demonstrate a proof-of-concept for the reintroduction of natural rhythms into built environments. / Master of Science

The Earth Radiation Budget Experiment (ERBE) is an operational system of radiometric instruments placed in Earth orbit by the National Aeronautics and Space Administration (NASA). Its purpose is to monitor those components of the Earth radiation budget which influence the weather and climate. The active cavity radiometer (ACR) instruments on board the ERBE satellites are periodically calibrated against internal standards and against the relatively well-known solar constant. In order to better understand the dynamic behavior of the instruments, a high resolution dynamic model has been developed and used to simulate the solar calibration. The instrument dynamic model consists of two elements: a radiation distribution factor model and a finite element model of the heat conduction process. The distribution factors, which lie at the heart of the simulation, distribute the thermal radiation incident to the instrument aperture over the diffuse-specular active cavity surface. The results of the model for a transient analysis during solar calibration are compared with two sets of operational data provided by NASA. Very acceptable agreement is found between the model results and the operational data. / Master of Science