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published_or_final_version / Geography and Geology / Master / Master of Philosophy

<p> A micrometeorological investigation was conducted over and within a crop of corn (Zea mays, var. Seneca Chief). The purpose of the experiment was to observe net radiation profiles within the canopy and to determine their behavior with respect to crop density. Discussion of the construction and evaluation of linear net radiometers for use in this study is included. The net radiation profiles are examined and compared with existing theoretical models. The form of the profiles is studied and a new model of net global radiation profiles based on micrometeorological data and crop parameters is discussed. </p> / Thesis / Master of Science (MSc)

The spectral distribution of the global radiation from 0.4 to 2.5 microns penetrating deciduous and coniferous canopies were measured during clear days between 10 a.m. and 2 p.m. using a double-quartz monochromator. In the visible region (0.4 to 0.7 micron) the average relative spectral transmissions under both canopies are about one percent beginning at 0.4 micron and decreasing to about half a percent at 0.67 micron. There is only a small peak in the green (0.55 micron) transmission under deciduous stands while there is none under coniferous canopies. The slightly higher transmission in the blue (0.4 micron) is attributed to the direct sky radiation penetrating through the gaps in the canopies. There is a steep increase in the transmission at about 0.7 micron. The increase is relatively higher under deciduous stands compared to coniferous stands. In the infrared region from 0.8 to about 1.4 microns, the average relative spectral transmission under deciduous stands is about 10 percent which is double the transmission under coniferous canopies. The transmission under deciduous stands is about twice that of the coniferous stands throughout the near infrared with very low transmission in the water absorption band at 1.45 and practically no transmission at all in the 1.90 micron-band. The absolute spectral transmission exhibit a somewhat different distribution, especially in the visible region. Since the highest intensity of the solar spectrum in the open is located in the 0.5 micron-band, this is also reflected in the absolute values. The small peak in the green under deciduous stands is now indicated as a slight shift of the peak to the 0.55 micron-band. The water absorption bands at the 0.95 and 1.15 microns are also distinct, with hardly no transmission at all beyond 1.7 microns. The spectral transmittance of forest canopies differ from those reported for single leaves in the proportion of radiation transmitted in the visible and infrared regions. For example, the ratio of the transmission at 0.55 micron to that at 1.10 micron-band is about one to twelve compared to about one to five in single leaves. A deciduous canopy consisting of several layers of leaves wi ll only allow a very small amount of transmission, mostly in the green portion and somewhat more in the infrared region between 0.72 and 1.40 microns. Under natural conditions in the forest, there exists a very weak "green" shadow and a somewhat stronger "infrared" shadow. The altered spectral composition may influence the understory vegetation as regards photosynthesis, seed germination, and the photoperiodic responses in the forest floor.

Solceller utvecklas ständigt med avseende på effektivitet och i samband med modulernas minskade inköpskostnad intresserar sig allt fler människor för solenergi. Solen är den renaste energikällan och det finns en stor potential för lönsamma anläggningar i Sverige sett till mängden solinstrålning. Arbetet syftar till att projektera en solcellsanläggning åt Ljusdalshem och beräkna dess lönsamhet. Vidare undersöks solcellens uppbyggnad, vilka solcellstyper som finns på marknaden idag samt vilka faktorer som påverkar en projektering. Undersökningen har genomförts med litteraturstudie av tryckta källor med internet som komplement. En del av informationen har också samlats in från personalen på Ljusdalshem samt från en leverantör med erfarenhet inom området. Energiberäkningarna har utförts genom manuella beräkningar och två olika beräkningsprogram som komplement. Lönsamheten bedöms utifrån nuvärdesmetoden och Payoff-metoden. Fastigheten har två lämpliga takpartier, ett placerat åt sydöst och ett åt sydväst. Takets olika riktningar ger större produktionsspann över dagen men ger lägre totalproduktion. Anläggningen kommer bestå av monokristallina kiselsolceller, växelriktare och effektoptimerare. Tillsammans kan dessa producera el motsvarande 17 procent av fastighetens årsförbrukning. I fastigheten bedrivs verksamheter dagtid, vilket passar bra för att ta emot producerad energi från solceller. Med hänsyn tagit till elprisökning, diskonteringsfaktor, modulerna degradering och nyinvesteringar har nuvärdet påvisat en investering som inte är lönsam. Investeringsstöd till solcellsanläggningar finns att söka hos Länsstyrelsen och är en förutsättning för att anläggningen ska ha en chans att bli lönsam, en lönsam investering kräver även att elprisökningen är större än den antagna. Åtgärder som sänker elförbrukningen ska utföras, beräkningarna baseras därför på en lägre förbrukning än den aktuella. En ännu lägre elförbrukning skulle ge ett annat resultat, vilket är en anledning till att göra nya mer exakta beräkningar när den nya årförbrukningen blir känd. Återbetalningstiden för investeringen är längre än den tekniska livslängden och därmed bidrar inte installationen till företagets lönsamhet med det antagna elpriset och övriga villkor. Då anläggningen ska ses som en referensanläggning och Ljusdalshem har ett miljömål att uppnå finns möjlighet till investering trots de ekonomiska förlusterna. / Solar cells are constantly evolving with regard to efficiency, and in connection with the modules' reduced purchasing costs, more and more people are becoming interested in solar energy. The sun is the purest source of energy, and there is a great potential for profitable plants in Sweden, given the amount of solar radiation. The project is to plan a solar cell facility for Ljusdalshem and calculating its profitability. Furthermore, the structure of the solar cell is investigated, which types of solar cells are present on the market today, and what factors affect the plan. The survey has been conducted with a literature study of printed sources with internet as a complement. Some of the informat-ion has also been collected from the staff at Ljusdalshem and from a supplier with experience in the area. The energy productions were carried out through manual calculations and two different calculation tools as a complement. Profitability is judged based on the present value method and the payoff method. The building has two suitable roof areas, one located to the south-east and one to the southwest. The different directions of the roof provide a larger production span over the day but inhibit overall solar energy production. The plant will consist of monocrystalline silica sols, inverters, and power optimizers. Together they can produce electricity corresponding to 17 percent of the annual consumption. Activities in the building are conducted during daytime, which fits well to receive produced energy from solar cells. Taking into account electricity price increase, discount factor, re-construction, and reinvestment modules, the present value has shown an investment that is not profitable. Investment support for solar power plants is available at the County Administ-rative Board, and is a prerequisite for the profitability of the plant. A profitable investment also requires that the electricity price increase is greater than assumed. Measures that reduce electricity consumption should be performed, therefore, the calculations are based on a lower consumption than the current one. An even lower power consumption would give another result, which is a reason for making more accurate calculations when the new annual consumption becomes known. The repayment period for the investment is longer than the technical life and thus does not contribute to the company's profitability with the assumed electricity price and other terms. Since the plant is to be regarded as a reference facility and Ljusdalshem has an environmental objective to achieve, there is an opportunity for investment despite the economic losses.

Made available in DSpace on 2017-07-25T19:29:46Z (GMT). No. of bitstreams: 1 ADRIANE ALFARO.pdf: 478436 bytes, checksum: 38077f5d85fcdb2030ceb8b23724f463 (MD5) Previous issue date: 2009-07-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to assess and develop a physical mathematical model to estimats the net radiation. For this we used weather data collected from the meteorological station of the Department of Physics and Meteorology of the Escola Superior de Agricultura "Luis de Queiroz" - ESALQ - University of São Paulo - USP, Piracicaba, Brazil, according to the global radiation (Qg) relative humidity (UR) and average daily temperature (T).The proposed methodology let us to determine the net radiation based on data more easily accessible and relevant to various daily human activities and therefore of great importance in engineering projects aimed at harnessing solar energy in its many forms. The performance of the model estimate of net radiation and its application in determining the potential evapotranspiration was verified by analyzing the coefficients of determination (R2) and agreement index of Willmott (d) applied to the observed and estimated data. The values estimated by the proposed method were compared with values measured by a net radiometer and the results showed that the proposed methodology was efficient for the estimation of net radiation with speed and simplicity. The data set was subjected to a simple linear regression analysis, obtaining a good adjustment between measured and estimated values. The use of estimated net radiation was efficient in the estimation of evapotranspiration by the methods of Penman Monteith, Priestley Taylor adjusted and Penman modified by the proposed model with a good adjustment when compared with the values measured for a period of 89 days, with determination coefficient (R2) ranging from 0.910 to 0.940. The proposed methodology is applicable when the meteorological variables needed to estimate potential evapotranspiration when not always are available, particularly those related to the solution of the aerodynamic term (wind velocity and vapor pressure deficit in the air), thus the methods are important to estimate the ETo based on climatic elements that can be obtained in a practice way. The satisfactory correlation found with the net radiometer makes the method of potential use in the region under study because the knowledge of evapotranspiration or latent heat flux contributes to a more rational use of water in crops in critical stages of growth and reproductive when water is a limited factors. Thus, for the climate of the town looked, it was possible to estimate with good precision the value of the net radiation, based on the theory proposed generating equivalent values those obtained by classical methodology for Piracicaba, SP. / O presente trabalho teve por objetivo propor e aferir um modelo físico matemático para estimar a radiação líquida e sua aplicação na determinação da evapotranspiração potencial. Para tanto foram utilizados dados climáticos coletados da Estação Meteorologia do Departamento de Engenharia Rural da Escola Superior de Agricultura “Luis de Queiroz”- ESALQ – da Universidade de São Paulo – USP, Piracicaba, SP, Brasil, em função da radiação global (Qg), da umidade relativa do ar (UR) e temperatura média diária (T). A metodologia proposta permite determinar a radiação líquida em função de dados mais facilmente disponíveis, sendo relevante nas diversas atividades humanas diárias e, portanto, de suma importância em projetos de engenharia que visam o aproveitamento da energia solar nas suas mais variadas formas. O desempenho do modelo proposto foi verificado através da análise dos coeficientes de determinação (R2) e dos índices de concordância de Willmott (d) aplicados aos dados estimados e observados. Os valores estimados pela metodologia proposta foram confrontados com os valores medidos por um saldo radiômetro e os resultados revelaram que a metodologia proposta mostrou-se eficiente para a estimativa da radiação líquida com rapidez e simplicidade. O conjunto de dados foi submetido a uma análise de regressão linear simples, obtendo-se bom ajuste entre os valores medidos e estimados. A utilização da radiação líquida estimada mostrou-se eficiente na estimativa da evapotranspiração pelos métodos de Penman-Monteith, Priestley-Taylor ajustado e Penman modificado, com bom ajustamento quando comparado com os valores medidos para um período de 89 dias, com coeficiente de determinação (R2) variando de 0, 910 a 0,940. A metodologia proposta tem aplicabilidade quando as variáveis meteorológicas necessárias para estimar evapotranspiração potencial nem sempre se encontram disponíveis, particularmente as relacionadas à solução do termo aerodinâmico (velocidade do vento e déficit de pressão do vapor d'água no ar); desta forma, tornam-se importantes os métodos para estimar a evapotranspiração potencial em função de elementos climáticos que podem ser obtidos de maneira mais prática. A correlação satisfatória verificada com o saldo radiômetro torna o método de uso potencial na região em estudo, pois o conhecimento da evapotranspiração ou do fluxo convectivo de calor latente contribui para uma utilização mais racional da água em uma determinada cultura em que as fases críticas de desenvolvimento vegetativo e reprodutivo são limitadas pelo fator hídrico. Assim, para as condições climáticas da localidade analisada, foi possível estimar com boa precisão o valor da radiação líquida, fundamentada na teoria proposta gerando valores equivalentes aqueles obtidos pela metodologia clássica para Piracicaba, SP.

Os vegetais apresentam defesa natural contra os fatores externos, bióticos e abióticos, por meio da síntese de compostos fenólicos no metabolismo secundário, as quais variam com as fases fenológicas e com o clima. O aumento dos compostos fenólicos nas plantas está, diretamente, relacionado com a resistência à infecção por patógenos e à infestação de pragas. Entretanto, pouco se sabe sobre a variação dos teores dessa substância durante os estádios fenológicos do cafeeiro, em particular, nas fases de frutificação, e em razão das condições climáticas. Tais conhecimentos são fundamentais para a previsão dos riscos de ataques aos vegetais, uma vez que a defesa natural da planta deve mudar ao longo do ciclo. O experimento foi realizado em uma cultura de Coffea arabica L., cultivar Obatã IAC 1669-20, instalada no campo experimental do Departamento de Produção Vegetal, da Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba/SP. Para a realização do experimento foi adotado o delineamento experimental inteiramente casualizado, utilizando quatro tratamentos (plantas com e sem frutos - folhas dreno e plantas com e sem frutos - folhas fonte) e cinco repetições constituídas por plantas individuais. Após a análise de variância dos resultados foi aplicado o teste t de Student ao nível de 5 % de significância para a comparação das médias entre os tratamentos. Os teores de fenóis totais (µg g-1) foram extraídos das folhas maduras (fonte) e novas (dreno) e analisados em relação à produção de café, fenologia e clima. As variáveis climáticas adotadas foram temperatura atmosférica (média, mínima e máxima; oC), radiação global (MJ m-2 dia-1) e insolação diária (h dia-1). Durante a condução do experimento foram realizadas avaliações de altura da planta (cm), diâmetro do caule (mm) e comprimento de ramos plagiotrópicos (cm) para determinar as respectivas taxas de crescimento vegetativo das plantas. As quantidades de fenóis totais determinadas nas plantas com produção (17.40 µg g-1 e 13.89 µg g-1 folhas dreno e fonte, respectivamente) e sem produção de café (18.65 µg g-1 e 12.76 µg g-1 folhas dreno e fonte, nessa ordem) não variaram. No entanto, a concentração de fenóis totais nas folhas novas (dreno) das plantas com e sem produção de café foi maior que a quantidade determinada nas folhas maduras (fonte), da ordem de 25 % e 46 %, respectivamente. A síntese de fenóis nas fases de expansão (16.35 µg g-1) e granação dos frutos (14.68 µg g-1) foi 31 % inferior em relação às quantidades determinadas na fase de maior produção dessas substâncias - fruto em maturação (21.24 µg g-1). A metabolização de fenóis totais depende, indiretamente, da temperatura (oC) e da radiação global (MJ m-2 dia-1), apresentando tendência inversa em relação a estas variáveis climáticas. A orientação do manejo fitossanitário deve levar em consideração as épocas em que há comprometimento da defesa natural da planta, em relação à produção de substâncias protetivas - os fenóis. / The vegetables show a natural defense against external factors, biotic and abiotic, by the synthesis of the phenolic compounds in the secondary metabolism, which varies with the maturity state and with the climate. The increase of phenolic compounds in the plants is directly related to the resistance to the infection thought pathogens and insect infestation. However, little is known about the variation in the content of this substance during the maturity state of the coffee tree, particularly in the fructification phases due to the climatic variations. Such knowledge is the base for the risks analyses of attacks to vegetables, since the natural defense of the plant shall change during the cycle. The experiment was carried out in a Coffea arabica L. crop, to cultivar Obatã IAC 1669-20, installed in the experimental field of the department of vegetal production of the Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Piracicaba/SP. For the accomplishment of the experiment it was adopted a totally randomized experimental design, using four treatments (plants with and without fruits - drain leaves and plants with and without fruits - source leaves) and five repetitions consisting of individual plants. After analysing the variance of the results it was applied Student t test at the level of 5 % of significance to compare the averages between the treatments. The total phenol grade (µg g-1) have been extracted from the mature (source) and new (drain) leaves and have been analyzed in relation to the coffee yield, phenology and climate. The climatic conditions adopted were atmospheric temperature (average, minimum and maximum; oC), global radiation (MJ m-2 day-1) and daily insolation (h day-1). During the conduction of the experiment it was analyzed the evaluations of the height (cm), diameter (mm) and length of the reproductive branches (cm) to determine the respective vegetative growth rates of the plants. The determined amounts of total phenols in the plants with production (17.40 µg g-1 and 13.89 µg g-1 drain and source leaves, respectively) and without coffee production (18.65 µg g-1 and 12.76 µg g-1 drain and source leaves, respectively) did not varied. However, the total phenol concentrations in new leaves of the plants with and without coffee production were greater than the amount determined in mature leaves around 25 % and 46 %, respectively. The secondary substance synthesis in the phases of expansion (16.35 µg g-1) and grain filling of the fruits (14.68 µg g-1) was 31% lower than the amounts determined in the phase of the greatest production of these substances - fruit in maturation (21.24 µg g-1). The total phenol metabolization depends indirectly on the temperature (oC) and on the global radiation (MJ m-2 day-1), presenting inverse trend in relation to these climatic variable. The orientation of the crop protection managing shall take into consideration the period when it has endangerment of the natural defense of the plant.

Os vegetais apresentam defesa natural contra os fatores externos, bióticos e abióticos, por meio da síntese de compostos fenólicos no metabolismo secundário, as quais variam com as fases fenológicas e com o clima. O aumento dos compostos fenólicos nas plantas está, diretamente, relacionado com a resistência à infecção por patógenos e à infestação de pragas. Entretanto, pouco se sabe sobre a variação dos teores dessa substância durante os estádios fenológicos do cafeeiro, em particular, nas fases de frutificação, e em razão das condições climáticas. Tais conhecimentos são fundamentais para a previsão dos riscos de ataques aos vegetais, uma vez que a defesa natural da planta deve mudar ao longo do ciclo. O experimento foi realizado em uma cultura de Coffea arabica L., cultivar Obatã IAC 1669-20, instalada no campo experimental do Departamento de Produção Vegetal, da Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba/SP. Para a realização do experimento foi adotado o delineamento experimental inteiramente casualizado, utilizando quatro tratamentos (plantas com e sem frutos - folhas dreno e plantas com e sem frutos - folhas fonte) e cinco repetições constituídas por plantas individuais. Após a análise de variância dos resultados foi aplicado o teste t de Student ao nível de 5 % de significância para a comparação das médias entre os tratamentos. Os teores de fenóis totais (µg g-1) foram extraídos das folhas maduras (fonte) e novas (dreno) e analisados em relação à produção de café, fenologia e clima. As variáveis climáticas adotadas foram temperatura atmosférica (média, mínima e máxima; oC), radiação global (MJ m-2 dia-1) e insolação diária (h dia-1). Durante a condução do experimento foram realizadas avaliações de altura da planta (cm), diâmetro do caule (mm) e comprimento de ramos plagiotrópicos (cm) para determinar as respectivas taxas de crescimento vegetativo das plantas. As quantidades de fenóis totais determinadas nas plantas com produção (17.40 µg g-1 e 13.89 µg g-1 folhas dreno e fonte, respectivamente) e sem produção de café (18.65 µg g-1 e 12.76 µg g-1 folhas dreno e fonte, nessa ordem) não variaram. No entanto, a concentração de fenóis totais nas folhas novas (dreno) das plantas com e sem produção de café foi maior que a quantidade determinada nas folhas maduras (fonte), da ordem de 25 % e 46 %, respectivamente. A síntese de fenóis nas fases de expansão (16.35 µg g-1) e granação dos frutos (14.68 µg g-1) foi 31 % inferior em relação às quantidades determinadas na fase de maior produção dessas substâncias – fruto em maturação (21.24 µg g-1). A metabolização de fenóis totais depende, indiretamente, da temperatura (oC) e da radiação global (MJ m-2 dia-1), apresentando tendência inversa em relação a estas variáveis climáticas. A orientação do manejo fitossanitário deve levar em consideração as épocas em que há comprometimento da defesa natural da planta, em relação à produção de substâncias protetivas – os fenóis. / The vegetables show a natural defense against external factors, biotic and abiotic, by the synthesis of the phenolic compounds in the secondary metabolism, which varies with the maturity state and with the climate. The increase of phenolic compounds in the plants is directly related to the resistance to the infection thought pathogens and insect infestation. However, little is known about the variation in the content of this substance during the maturity state of the coffee tree, particularly in the fructification phases due to the climatic variations. Such knowledge is the base for the risks analyses of attacks to vegetables, since the natural defense of the plant shall change during the cycle. The experiment was carried out in a Coffea arabica L. crop, to cultivar Obatã IAC 1669-20, installed in the experimental field of the department of vegetal production of the Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Piracicaba/SP. For the accomplishment of the experiment it was adopted a totally randomized experimental design, using four treatments (plants with and without fruits – drain leaves and plants with and without fruits – source leaves) and five repetitions consisting of individual plants. After analysing the variance of the results it was applied Student t test at the level of 5 % of significance to compare the averages between the treatments. The total phenol grade (µg g-1) have been extracted from the mature (source) and new (drain) leaves and have been analyzed in relation to the coffee yield, phenology and climate. The climatic conditions adopted were atmospheric temperature (average, minimum and maximum; oC), global radiation (MJ m-2 day-1) and daily insolation (h day-1). During the conduction of the experiment it was analyzed the evaluations of the height (cm), diameter (mm) and length of the reproductive branches (cm) to determine the respective vegetative growth rates of the plants. The determined amounts of total phenols in the plants with production (17.40 µg g-1 and 13.89 µg g-1 drain and source leaves, respectively) and without coffee production (18.65 µg g-1 and 12.76 µg g-1 drain and source leaves, respectively) did not varied. However, the total phenol concentrations in new leaves of the plants with and without coffee production were greater than the amount determined in mature leaves around 25 % and 46 %, respectively. The secondary substance synthesis in the phases of expansion (16.35 µg g-1) and grain filling of the fruits (14.68 µg g-1) was 31% lower than the amounts determined in the phase of the greatest production of these substances - fruit in maturation (21.24 µg g-1). The total phenol metabolization depends indirectly on the temperature (oC) and on the global radiation (MJ m-2 day-1), presenting inverse trend in relation to these climatic variable. The orientation of the crop protection managing shall take into consideration the period when it has endangerment of the natural defense of the plant.

The first part deals with an introduction to the basic fundamentals and presentation of theory from the assignment. The fundamentals are presented and described in detail. This part is followed by chapter describing possibilities of using solar energy. The paper presents possibilities of using both direct and diffuse solar radiation. The last chapter of the theoretical part is devoted to the basic description of the IEC 60904 and IEC 60904-9 standards. The practical part presents selected solar simulators and their measurement. Classification class according to IEC 60904-9 is determined from this measurement. The last part of the work is devoted to the construction of a solar simulator composed of LEDs. The simulator is then measured and its class is determined by emitted spectrum.

MSc (Physics) / Department of Physics