Made available in DSpace on 2014-06-11T19:24:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-27Bitstream added on 2014-06-13T19:11:22Z : No. of bitstreams: 1 inacio_t_me_botfca.pdf: 488409 bytes, checksum: f07ac54da8077b5df98e78bea1785b2e (MD5) / No presente trabalho é apresentado o estudo do potencial da energia solar disponível no município de Botucatu, através das análises das séries temporais médias anuais diárias, médias mensais diárias e séries anuais dos acumulados mensais das radiações global, difusa e direta na horizontal do período de 1996 à 2005. As irradiações, em MJ/m2, foram calculadas a partir das integrações diárias das irradiâncias global , irradiância difusa , irradiância direta na horizontal e no topo da atmosfera , determinando-se as irradiações diárias: , e ; e médias mensais: G I d I D I O I dG H d d H dD H dGH , d d H e dD H . A partir das médias mensais, determinou-se o índice de claridade t K (razão da irradiação global pela do topo da atmosfera), e as demais frações das radiações: d K (razão da irradiação difusa pela global), ′ d K (razão da irradiação difusa pela do topo da atmosfera), D K (razão da irradiação direta pela global), ′ D K (razão da irradiação direta pela do topo da atmosfera). Realizou-se uma análise estatística dos dados de radiação solar, de forma a se obter os valores médios, desvios, máximos, mínimos, variação e acumulados, mensais e anuais. E apresentaram-se de forma gráfica os resultados estatísticos obtidos para compará-los com os valores médios mensais diários da precipitação, nebulosidade e insolação, para que se possam explicar os fenômenos que causam as variações nos valores da série temporal de radiação solar na superfície terrestre de Botucatu. Os valores médios mensais diários da radiação global variaram de 21,0 MJ/m² em novembro até 12,6 MJ/m² em junho. A fração t K media anual foi de 53,0%. Os valores médios mensais diários da radiação difusa variaram de 10,0 MJ/m² em dezembro... / The present work presents the potential of solar energy available in the city of Botucatu, by analyzing time series of annual average daily, monthly averages of daily and cumulative monthly series of annual global radiation, diffuse and horizontal direct in the period of 1996 to 2005. The irradiation in MJ/m2 were calculated from daily integrations of the global irradiance , diffuse irradiance , horizontal direct irradiance and at the top of the atmosphere , by providing daily the daily irradiation: , and ; and monthly averages: G I d I D I O I dG H d d H dD H dG H , d d H and dD H . From the monthly averages, it was determined the clearness index t K (global/top of the atmosphere irradiation), and other fractions of radiation: d K (diffuse/global irradiation), ′ d K (diffuse/top of the atmosphere irradiation), D K (direct/global irradiation), ′ D K (direct/top of the atmosphere irradiation). Was held a statistical analysis of data on solar radiation in order to obtain the average values, deviation, minimum, maximum, variation and cumulative, monthly and yearly. And it showed in graphic statistical results obtained to compare them with the monthly average daily values of precipitation, cloudiness and sunshine, so that can explain the phenomena that cause variation in te values of time series of solar radiation on the Earth's surface of Botucatu. The values daily monthly average global radiation varied from 21.0 MJ/m² in november to 12,6 MJ/m² in june. The average annual t K fraction was 53,0%. The values daily monthly average diffuse radiation varied from 10,0 MJ/m² in december to 3,7 MJ/m² in june. The average annual d K fraction was 37% and the average annual ′ d K fraction was 19,7%. The values daily average monthly direct radiation varied from 11,8 MJ/m² in november... (Complete abstract click electronic access below)

Resumo: No presente trabalho é apresentado o estudo do potencial da energia solar disponível no município de Botucatu, através das análises das séries temporais médias anuais diárias, médias mensais diárias e séries anuais dos acumulados mensais das radiações global, difusa e direta na horizontal do período de 1996 à 2005. As irradiações, em MJ/m2, foram calculadas a partir das integrações diárias das irradiâncias global , irradiância difusa , irradiância direta na horizontal e no topo da atmosfera , determinando-se as irradiações diárias: , e ; e médias mensais: G I d I D I O I dG H d d H dD H dGH , d d H e dD H . A partir das médias mensais, determinou-se o índice de claridade t K (razão da irradiação global pela do topo da atmosfera), e as demais frações das radiações: d K (razão da irradiação difusa pela global), ′ d K (razão da irradiação difusa pela do topo da atmosfera), D K (razão da irradiação direta pela global), ′ D K (razão da irradiação direta pela do topo da atmosfera). Realizou-se uma análise estatística dos dados de radiação solar, de forma a se obter os valores médios, desvios, máximos, mínimos, variação e acumulados, mensais e anuais. E apresentaram-se de forma gráfica os resultados estatísticos obtidos para compará-los com os valores médios mensais diários da precipitação, nebulosidade e insolação, para que se possam explicar os fenômenos que causam as variações nos valores da série temporal de radiação solar na superfície terrestre de Botucatu. Os valores médios mensais diários da radiação global variaram de 21,0 MJ/m² em novembro até 12,6 MJ/m² em junho. A fração t K media anual foi de 53,0%. Os valores médios mensais diários da radiação difusa variaram de 10,0 MJ/m² em dezembro... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : The present work presents the potential of solar energy available in the city of Botucatu, by analyzing time series of annual average daily, monthly averages of daily and cumulative monthly series of annual global radiation, diffuse and horizontal direct in the period of 1996 to 2005. The irradiation in MJ/m2 were calculated from daily integrations of the global irradiance , diffuse irradiance , horizontal direct irradiance and at the top of the atmosphere , by providing daily the daily irradiation: , and ; and monthly averages: G I d I D I O I dG H d d H dD H dG H , d d H and dD H . From the monthly averages, it was determined the clearness index t K (global/top of the atmosphere irradiation), and other fractions of radiation: d K (diffuse/global irradiation), ′ d K (diffuse/top of the atmosphere irradiation), D K (direct/global irradiation), ′ D K (direct/top of the atmosphere irradiation). Was held a statistical analysis of data on solar radiation in order to obtain the average values, deviation, minimum, maximum, variation and cumulative, monthly and yearly. And it showed in graphic statistical results obtained to compare them with the monthly average daily values of precipitation, cloudiness and sunshine, so that can explain the phenomena that cause variation in te values of time series of solar radiation on the Earth's surface of Botucatu. The values daily monthly average global radiation varied from 21.0 MJ/m² in november to 12,6 MJ/m² in june. The average annual t K fraction was 53,0%. The values daily monthly average diffuse radiation varied from 10,0 MJ/m² in december to 3,7 MJ/m² in june. The average annual d K fraction was 37% and the average annual ′ d K fraction was 19,7%. The values daily average monthly direct radiation varied from 11,8 MJ/m² in november... (Complete abstract click electronic access below) / Orientador: João Francisco Escobedo / Coorientador: Eduardo Nardini Gomes / Banca: Dinival Martins / Banca: Alexandre Dal Pai / Mestre

A terapia fotodinâmica é a combinação do agente fotossensibilizador, da fonte de luz e do oxigênio que pode resultar na oxidação de biomoléculas e gerar danos celulares. Esta técnica é aplicada em diversas situações, desde o controle microbiológico até o tratamento de câncer. A maioria dos estudos utiliza as fontes de luz tradicionais, ou seja, lasers, sistemas à LED e lâmpadas. No entanto, poucos são os estudos que se concentram em propostas de fonte de luz alternativas. Iluminação portátil, flexível e independente de energia elétrica são características de grande interesse, principalmente, aos países em desenvolvimento no qual há uma grande parcela da população não assistida por hospitais de referência, além de cidades que não possuem o fornecimento de energia elétrica. Neste estudo, foi avaliada a viabilidade do uso, in vitro, da quimiluminescência como uma fonte de luz para a terapia fotodinâmica, induzindo a redução microbiana de Staphylococcus aureus. A quimiluminescência é uma reação química onde por meio da mistura de reagentes líquidos ocorre a emissão de luz sem a necessidade de qualquer ativação externa. Previamente aos estudos da aplicação terapia fotodinâmica in vitro, foram avaliadas diversas reações de quimiluminescência no intuito de estabelecer as características mais viáveis ao efeito fotodinâmico. Através de um modelo similar a teoria de Förster, foi estabelecida a relação espectral entre a banda de emissão da quimiluminescência e o espectro de absorção do fotossensibilizador Photogem®. Na análise in vitro, o agente fotossensível foi utilizado em quatro concentrações entre 6 e 75 g/ml e iluminação entre 60 minutos até 240 minutos. Longos tempos de irradiação são necessários devido a baixa intensidade de luz oriunda da quimiluminescência (intervalo de algumas dezenas de W/cm²). Os resultados demonstraram que o longo tempo de experimento não gerou redução microbiana nos grupos em que foi avaliado o efeito isolado da fonte de luz e do fotossensibilizador. Porém, quando foi avaliado o efeito fotodinâmico na combinação da reação química e o fotossensibilizador, atingiu-se redução da bactéria próxima de 98% (redução de duas ordens logarítmicas, aproximadamente) nas maiores concentrações de Photogem® e de dose de luz aplicada. Este estudo demonstra a possibilidade do uso da quimiluminescência como uma fonte de luz alternativa no controle microbiano através do efeito fotodinâmico, além de apresentar as vantagens de irradiação portátil, flexível entre outras quando comparada com as fontes de luz convencionais. / Photodynamic therapy is a combined action of the photosensitizer, a light source and the oxygen that may result in an oxidation of biomolecules and cellular damage. This technique is used for several applications, from microbial control to cancer treatment. The majority of the studies use conventional light sources as lasers, LED systems and lamps, just a few focuse on the proposal of alternative light sources. Portable, flexible and non-wired illumination are duired characteristics especially for developing countries where still great part of the population is not assisted by hospitals and several regions do not have electricity. In this study, the viability of chemiluminescence use a PDT light source was evaluated in the in vitro microbial reduction of Staphylococcus aureus. Chemiluminescence is a chemical reaction where after the reagents mixture a light emission occurs. Previously to the microorganism experiment, several chemiluminescence protocols were tested for the determination of the best reaction for this study photodynamic effect. Using a mathematical model similar to the Förster theory, the spectral relation of chemiluminescence emission and Photogem® absorption band was calculated. The photosensitizer was tested at four concentrations between 6 an 75 g/ml and illumination at exposure times between 60 and 240 minutes. Long exposure times were needed due to the low irradiances of about dozens of W/cm².The results showed that the experiment long procedure did not result in microbial reduction, which was verified at the individual effect of light and of photosensitizer. On the other hand, the photodynamic effect produced by the combination of the photosensitizer and chemiluminescence resulted in 98% microorganism reduction for the higher Photogem® concentrations and light dose. This study shows the viability of the chemiluminescence as a light source for the microbial control by PDT, associated with the characteristics of a portable and flexible illumination device.

A radiação solar global (RG) é uma das variáveis meteorológicas mais importantes para a compreensão de processos biofísicos em ferramentas ao suporte de decisão na agricultura. Atualmente, ela pode ser medida por diferentes sensores de custo relativamente baixos e, de modo geral, apenas estações meteorológicas instaladas mais recentemente registram RG. Na falta de dados observados, torna-se necessário estimá-la através de modelos tão simples quanto possível e baseados em dados de entrada de fácil obtenção. O presente trabalho teve por objetivo analisar dois modelos (Bristow e Campbell (1984) (BC) e Hargreaves e Samani (1982) (H)) e otimizá-los estatisticamente, ajustando seus parâmetros, tomando como referência uma base de dados observados de 32 localidades pelo Instituto Nacional de Pesquisas Espaciais em todas as regiões brasileiras. O desempenho de cada modelo foi avaliado através do erro médio (EM), erro médio absoluto (EAM), coeficiente de determinação (R2), coeficiente de correlação (r), índice de concordância de Willmott (d) e raiz do erro médio quadrático (RMSE). Utilizando os parâmetros originais, o modelo H apresentou melhor desempenho, analisando RMSE, para todas as regiões brasileiras, com valores de 4.24 MJ.m-2d-1 para a região Norte, 4.55 MJ.m-2d-1 para a região Nordeste, 4.39 MJ.m-2d-1 para a região Centro Oeste, 4.61 MJ.m-2d-1 para a região Sul e 4.21 MJ.m-2d-1 para a região Sudeste. Após a otimização, o melhor desempenho foi dado pelo modelo BC, em todas as regiões do Brasil, com RMSE de 3.44 MJ.m-2d-1 para a Região Norte, 3.70 MJ.m-2d-1 para a região Nordeste, 3.62 MJ.m-2d-1 para a região Centro Oeste, 4.43 MJ.m-2d-1 para a região Sul e 3.50 MJ.m-2d-1 para a região Sudeste. Com a otimização dos parâmetros, encontraram-se valores médios para KT, utilizada pelo modelo de H: 0.152 °C-0,5 para a região Norte, 0.173 °C-0,5 para a região Nordeste, 0.145 °C-0,5 para a região Centro Oeste, 0.163 °C-0,5 para a região Sul e 0.152 °C-0,5 para a região Sudeste. Para os parâmetros adimensionais \"A\", \"B\" e \"C\" do modelo BC obteve-se para cada região, respectivamente, os seguintes valores: 0.619, 0.026 e 1.845 para a região Norte, 0.694, 0.074 e 1.489 para a região Nordeste, 0.635, 0.029 e 1.697 para a região Centro Oeste, 0.671, 0.044 e 1.580 para a região Sul e 0.702, 0.025 e 1.747 para a região Sudeste. / Global solar radiation (RG) is one of the most important weather variables for understanding the biophysical processes in agricultural support tools. Currently, it can be measured by different low cost sensors. In Brazil, weather stations just recently start to record RG values. In the absence of long term observed data, models for estimating RG are needed, and the objective of this study was to analyse two Bristow and Campbell (1984) (BC) and Hargreaves and Samani (1982) (H) models for different regions in Brazil against a reference database of 32 places collected the National Institute of Space Research (INPE) through the coefficient of determination (R2), correlation coefficient (r), Willmott concordance index (d), modelling efficiency (E), and root mean square error (RMSE). They were also statistically optimized based on an iterative approach. Using the original parameters, the H model presented the best performance for all Brazilian regions, with values with RMSE of 4.24 MJ.m-2d-1 for a North region, 4.55 MJ.m-2d-1 for the Northeast Region, 4.39 MJ.m-2d-1 for a Midwest region, 4.61 MJ.m-2d-1 for a South region and 4.21 MJ.m-2d-1 for a Southeast region. After the optimization process, the best performance was given by the BC model for all Brazilian regions, with RMSE of 3.44 MJ.m-2d-1 for a North Region, 3.70 MJ.m-2d-1 for a Northeast region, 3.62 MJ.m-2d-1 for a Midwest region, 4.43 MJ.m-2d-1 for a South region and 3.50 MJ.m-2d-1 for a Southeast region. After the parameter optimization, mean values for KT for H model were 0.152 °C-0.5 for the North region, 0.173°C-0.5 for the Northeast region, 0.145°C-0.5 for the Midwest region, 0.163 °C-0.5 for the South region and 0.152°C-0.5 for the Southeast region. For the BC´s dimensionless parameters \"A\", \"B\" and \"C\" it was found the following values, respectively: 0.619, 0.026 and 1.845 for the North region, 0.694, 0.074 and 1.489 for the Northeast region, 0.635, 0.029 and 1.697 for the Midwest region, 0.671, 0.044 and 1.580 for the South region, and 0.702, 0.025 and 1.747 for the Southeast region.

This thesis presents an energy prediction tool for photovoltaic (PV) modules, based on the measure-correlate-predict principle. The tool allows quantification of the impact of the different environmental factors influencing PV device efficiency for different sites as they deviate from standardised test conditions and combines their effects for energy yield prediction of different module technologies operating in different climates. Amongst these environmental influences, the impact of angle of incidence has been particularly under-researched. In this work, a systematic investigation of the influence of angle of incidence on PV module performance is realised. This is achieved using both short-term module characterisation and long-term energy yield measurement campaigns. A customised purpose built dual axis tracker for mounting paired sets of modules on a fixed south-facing, 45-degree tilted rack is used to investigate the differences in module performance. The quality and quantity of the composition of the incident irradiance is described for various sky conditions at high latitude locations. Furthermore, an understanding of the entangled effects on photocurrent of both the angle of incidence and spectral variation is presented. This is achieved by analysing data from a system developed especially in this work which integrates an instantaneous all-sky mapping of irradiance from a monochromatic CCD camera with precision measurements of small-aperture normal irradiance from a collimated pyranometer in the short-term measurement campaign. The proposed energy prediction tool is validated using long-term datasets from several locations and is compared to other current methods. This was conducted under the European-funded PV-Catapult and IP Performance projects. The tool's prediction uncertainty falls within the ±5% for crystalline and ±10% for thin films, which is the same accuracy as other methods and within the measurement uncertainty of outdoor measurements.

No description available.

On the reefs of Bermuda, the coral Diploria labyrinthiformis is rarely infected with black band disease (BBD) while BBD-infected colonies of D. strigosa are common. This study investigated several possible explanations for the documented difference in BBD prevalence including: 1) temperature and light conditions differentially affect the progression of the disease among these two species; 2) the bacterial communities associated with each species are different and 3) the bacterial composition of BBD in Bermuda is unique from that of other geographical regions where D. labyrinthiformis has been reported with BBD. Results suggest that light and temperature are important variables in determining BBD progression for both species; reef location, rather than coral species dictates the coral associated bacterial diversity; and the BBD bacterial mat in Bermuda is unique compared to other regions of the Caribbean. Many factors are likely responsible for the low occurrence of BBD among D. labyrinthiformis in Bermuda.

Concentrator photovoltaics is a promising renewable energy technology, especially for utility or large-scale deployments. Like all new technologies, it has obstacles and setbacks to overcome. More specifically, the optics in a concentrator photovoltaics system introduce non-uniform spatial and spectral illumination on the cell, which can change under different operating conditions. This work was put together to discover a new characterization technique capable of analyzing the performance of a concentrator photovoltaics and provide insight to the field on what is happening within the system, linking modeling results seen in the literature to these experimental outcomes. The thesis is composed of three journal papers written by the candidate, who’s contributions are outlined at the beginning of each chapter. In order to study the illumination profiles on the cells, a new method to characterize the optical components had to be developed. Previous version lacked the ability to control the temperature of the lens and had low spectral resolution of the irradiance profiles. To improve, a novel indoor measurement method was developed capable of spectrally imaging concentrator photovoltaics optics and recreate outdoor operating conditions in a controllable environment. With the calibrated system, our test-bench is capable of measuring the spectral distribution with a 10μm2 resolution and characterizing the output of a system to within 3%. Exploiting this experimental technique, the individual effects of module misalignment, cell to primary distance, and lens temperature was studied for three leading technologies associated with the three generations of concentrator photovoltaics optical architectures. Focusing on Fresnel-based concentrator optics, the performance of silicone on a glass module without a secondary optic is the most sensitive to operating conditions, where lens temperature can decrease the absolute efficiency resulting in a difference of 11% in the annual energy yield. The next two generations have secondary optics but are designed slightly differently. The truncated inverted pyramid, designed independently of the primary optic, favoured higher lens temperature values and there was only a difference of 1% in the energy yield calculation. The primary and secondary optics in the 4-fold Fresnel-Kohler are designed together, due to new development tools, and showed the highest stability under the different operating conditions, demonstrating that concentrator photovoltaics is on the right track to overcoming its onset issue. As the technology matures, future designs can improve on the issues characterized within this thesis.

Sizing renewable energy power plants with storage devices needs new resource assessment. Global amount of energy available has to be replaced by time series to depict the resource as a function of time. This paper introduces methodology to generate time series for wind speed and solar irradiance with a granularity between 10minutes and 1seconde. Ground measurements and macro-date from satellite imagery are analyzed and processed to obtain long-term site-specific time series. Because renewable energy forecasting is a growing concern, a second part of the work presents how to modify previously generated profiles in order to obtain forecasts with an expected error.

Solar energy is widely used for electricity generation, heating systems, and indoor environment daytime illumination. Indeed, large amounts of Sunlight energy remain insufficiently used. In this work, we aim at employing sunlight for data transmission as another option for wireless communications. Being emitted by an uncontrollable source, taming the Sunlight is a challenging task that requires appropriate technolo- gies to manipulate incident light. Throughout this thesis, we first review switchable glass technologies and investigate their potential use for light modulation. Liquid Crystal Devices (LCD) have adequate response time and contrast characteristics for such an application. In this regard, we design a novel Dual-cell Liquid Crystal Shutter (DLS) by stacking two Liquid Crystal cells that operate in opposite manners, and we build our Sunlight modulator with an array of DLSs. Then, we adopt Time Division Multiplexing and polarization-based modulation to boost the data rate and eliminate the flickering effect. In addition, we provide mathematical modeling of the system and study its performance in terms of communication and energy consumption. Finally, we introduce some numerical results to examine the impact of multiple parameters on the system’s performance and compare it with state-of-the-art, which showed that our system features higher data rates and extended link ranges.