Orientador: Alex Sandro Campos Maia / Coorientador: Vinícius de França Carvalho Fonseca / Banca: Sheila Tavares Nascimento / Banca: Marcelo Simão da Rosa / Resumo: O estudo dos efeitos do ambiente térmico radiante sobre as respostas fisiológicas e termorregulação de animais sob diferentes ambientes em região tropical pode resultar em achados relevantes sobre a adaptação a esse meio. O presente estudo teve como objetivo investigar as respostas termorregulatórias de vacas da raça Holandesa expostas e protegidas da radiação solar direta. Foram utilizadas doze vacas Holandesas multíparas com produção média de leite de 20 kg, 676 kg de peso vivo e 120 dias de ordenha, foram distribuídas aleatoriamente em quatro quadrados latinos 6x6 sob duas condições ambientais distintas, sendo seis animais destinados a um piquete com pastagem e seis estabulados em galpão tipo Free Stall. As variáveis meteorológicas avaliadas foram temperatura do ar (TAR, °C), umidade relativa (UR, %), radiação solar (RS, W m-2 ), temperatura radiante média (TRM, °C) e velocidade do vento (VV, m s-1 ). Dados fisiológicos, incluindo frequência respiratória (FR, resp mín-1 ), ventilação (VE, L s-1 ), proporções dos gases respiratórios (oxigênio, O2; dióxido de carbono, CO2; metano, CH4), temperatura retal (TR, °C), da epiderme (TEP, °C) e temperatura superficial (TS, °C). Ao caracterizar o ambiente térmico radiante foi evidenciado que há um menor gradiente de temperatura entre TS e TRM em comparação ao gradiente entre TS e TAR mesmo em animais protegidos da radiação solar direta. A exposição das vacas a radiação solar direta influenciou na elevação das temperaturas profundas ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The study of the effects of radiant thermal environment on the physiological responses and thermoregulation of animals under different environments in a tropical region may result in relevant findings on the adaptation to this environment. This work aimed to investigate the thermoregulatory responses of Holstein cows protected and exposed to direct solar radiation. Twelve multiparous Holstein cows with average milk yield of 20 kg, 676 kg of live weight, and 120 days in milking, were randomly assigned in four 6x6 latin square design under two management system, being six subjects managed on pasture and six in housed system. The following variables were evaluated: air temperature (AT, °C), relative humidity (RH,%), solar radiation (SR, W m-2 ), mean radiant temperature (MRT, °C) and wind speed (WS, m s-1 ). Physiological data including respiratory rate (RR, breaths min-1 ), ventilation (VE, L s-1 ), proportions of respiratory gases (oxygen, O2; carbon dioxide, CO2; methane, CH4). Additionally, rectal (TR, °C), skin (TEP, °C), and hair coat surface temperature (TS, °C) were also collected. In characterizing the radiant thermal environment it was evidenced that there is a lower temperature gradient between TS and TRM compared to the gradient between TS and TAR even in animals protected from direct solar radiation. The exposure of cows to direct solar radiation influenced the elevation of deep temperatures and consequently greater heat losses in a sensitive and latent way in compa... (Complete abstract click electronic access below) / Mestre

I analyzed the 21 year dynamics of dissolved organic carbon (DOC) in 55 lakes in five sites across Eastern Canada in relation to regional and global variables. Regional variables included total solar radiation (TSR), precipitation (PPTN), air temperature (T) and sulfate deposition (SO4). Global variables included the Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO) and Pacific Decadal Oscillation (PDO). A synchronous pattern in DOC was found among lakes within each region; however, a synchronous pattern in DOC was not found between sites, except for Kejimkujik and Yarmouth which were only 80 km apart from each other. This suggested that the variation of the long-term DOC pattern was in response to the temporal pattern of regional variables, and it supports the recent understanding that regional factors have a strong influence on many lake properties. Significant long-term trends in DOC were not evident except at the Experimental Lakes Area (ELA), where an increase in DOC was observed together with a decrease in summer TSR and an increase in summer precipitation. Annual mean air temperature has increased at the Nova Scotia and Turkey lakes sites over the study period. The relationship between the long-term pattern in DOC with the regional and global variables was analyzed for each study site to determine the key variables that could best explain the variation in the long-term pattern in DOC. TSR and PPTN were important independent variables across all sites, except for the Turkey Lakes Watershed site (TLW). Summer TSR (annual TSR for Kejimkujik and Yarmouth) had a negative relationship, while summer precipitation had a positive relationship with the long-term DOC pattern for all sites except TLW. TSR and PPTN explained 78%, 49% and 84% of the variation in the long-term DOC pattern at Dorset, ELA, and Nova Scotia (NS) sites, respectively. In contrast, the long-term pattern in DOC at TLW only had a weak relationship with the regional and global variables considered. A General model was developed to compare the strength of the response of DOC to the regional variables among sites. Therefore, only the variables which had a significant linear correlation with DOC across sites were selected. If a site had no variables in common with other sites, it was excluded from the general model. This resulted in TLW being excluded from the general model because the long-term DOC pattern at TLW was not significantly correlated with any regional variables. The best general model included TSR from Dorset, ELA and NS sites and precipitation from only the NS site. The strengths of the response of DOC to precipitation were weak at Dorset and ELA compared to NS, therefore, they were excluded. The general model explained 91% of the site-to-site variation of DOC among sites. Among them, TSR was an important negative variable which contributed 56% of the explanation to the general model. Precipitation at NS was an important positive variable for the general model. It contributed 34% of the explanation to the model. As the response of the long-term DOC pattern to the changes of environmental variables (TSR and PPTN) was very strong at NS, the NS site dominated the general model, and its temporal (year-to-year) variation in the long-term DOC pattern explained 60% of the site-to-site variation of DOC in Eastern Canada. The other two sites, Dorset and ELA, had weak contributions (20% and 11%, respectively) to the general model.

In this thesis, 41 years of bright sunshine duration (SD) data of 192 meteorological stations in Turkey were analyzed. The main objective is to determine the trends of SD data and the importance of such analyses is the high correlation between SD data and solar irradiation reaching the surface of the earth. Because of the missing value problems, only the data set for 72 stations were examined. After imputing missing values of these stations by expectation maximization algorithm, to test the homogeneity Kruskal Wallis test (K-W) and Wald-Wolfowitz runs test for randomness were applied. Only 36 of the stations passed from these homogeneity tests therefore, trend analysis was carried out for these locations. To exclude the data sets which did not pass from the tests was important to reach more accurate trend analysis of the data in hand. Results of the trend analysis showed that the change of SD over the 41 years are in agreement with the globally identified surface solar radiation dimming and brightening time periods all over the world. The dimming period is mainly between the years 1970 and about 1990 while the brightening period is from about 1990 to 2010. The yearly averages of SD data sets of 27 locations out of 36, for the years in the dimming period, were in a good agreement with the global dimming trends. However, for the brightening period the agreement was not as clear as it was in the dimming period. Nevertheless, during the brightening period, the data set of most of the locations had zero trends or noticeably reduced rates of decrease of SD. The dimming might be attributed to the increase in air pollution and this might be an indication of human induced climate change. Larger amounts of negative trends during winter months supported this conclusion. However, to reach a concrete conclusion more accurate of different climatic parameters should be analyzed. Satellites images may be helpful for further clarifications of such conclusions on climate change issues.

I analyzed the 21 year dynamics of dissolved organic carbon (DOC) in 55 lakes in five sites across Eastern Canada in relation to regional and global variables. Regional variables included total solar radiation (TSR), precipitation (PPTN), air temperature (T) and sulfate deposition (SO4). Global variables included the Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO) and Pacific Decadal Oscillation (PDO). A synchronous pattern in DOC was found among lakes within each region; however, a synchronous pattern in DOC was not found between sites, except for Kejimkujik and Yarmouth which were only 80 km apart from each other. This suggested that the variation of the long-term DOC pattern was in response to the temporal pattern of regional variables, and it supports the recent understanding that regional factors have a strong influence on many lake properties. Significant long-term trends in DOC were not evident except at the Experimental Lakes Area (ELA), where an increase in DOC was observed together with a decrease in summer TSR and an increase in summer precipitation. Annual mean air temperature has increased at the Nova Scotia and Turkey lakes sites over the study period. The relationship between the long-term pattern in DOC with the regional and global variables was analyzed for each study site to determine the key variables that could best explain the variation in the long-term pattern in DOC. TSR and PPTN were important independent variables across all sites, except for the Turkey Lakes Watershed site (TLW). Summer TSR (annual TSR for Kejimkujik and Yarmouth) had a negative relationship, while summer precipitation had a positive relationship with the long-term DOC pattern for all sites except TLW. TSR and PPTN explained 78%, 49% and 84% of the variation in the long-term DOC pattern at Dorset, ELA, and Nova Scotia (NS) sites, respectively. In contrast, the long-term pattern in DOC at TLW only had a weak relationship with the regional and global variables considered. A General model was developed to compare the strength of the response of DOC to the regional variables among sites. Therefore, only the variables which had a significant linear correlation with DOC across sites were selected. If a site had no variables in common with other sites, it was excluded from the general model. This resulted in TLW being excluded from the general model because the long-term DOC pattern at TLW was not significantly correlated with any regional variables. The best general model included TSR from Dorset, ELA and NS sites and precipitation from only the NS site. The strengths of the response of DOC to precipitation were weak at Dorset and ELA compared to NS, therefore, they were excluded. The general model explained 91% of the site-to-site variation of DOC among sites. Among them, TSR was an important negative variable which contributed 56% of the explanation to the general model. Precipitation at NS was an important positive variable for the general model. It contributed 34% of the explanation to the model. As the response of the long-term DOC pattern to the changes of environmental variables (TSR and PPTN) was very strong at NS, the NS site dominated the general model, and its temporal (year-to-year) variation in the long-term DOC pattern explained 60% of the site-to-site variation of DOC in Eastern Canada. The other two sites, Dorset and ELA, had weak contributions (20% and 11%, respectively) to the general model.

Global climate models (GCM) have been used for nearly two decades now as a tool to investigate and analyze past, present, and future weather and climate. Even though the first several generations of climate models were very simple, today's models are very sophisticated. They use complex parameterization schemes to approximate many nonlinear physical fields. In these models, the resolution and time steps can be set to be as small or as large as desired. In either case, the model generates over 100 atmospheric variables and 20 land surface variables that can be reported daily or monthly. The Community Atmospheric Model Version Two global climate model spends over sixty percent of the time computing shortwave and longwave parameterization schemes. Our goal is to replace its shortwave scheme with empirical methods and show that accuracy of the tropospheric variables is not compromised when using these empirical methods. We found that an autoregressive moving average (ARMA) model can be used to simulate the solar radiation at the top of the model atmosphere. However, the calculated insolation value is only valid for one particular grid point. To simulate the radiation over the entire globe, many ARMA models need to be determined. We also found that large 4-10-10-1 neural networks can be used to simulate the solar radiation to within 2 W m-2. However, much smaller and manageable neural networks can be used to simulate the complete solar insolation term if the neural network only simulates the residual after the annual and diurnal cycles and removed from the field (referred to as the - method). By using the neural network in the - method and by setting the eccentricity term to a constant, we were able to cut the models processing of the solar insolation by at least a factor of four.

Sunshine, air and water are the vital elements to the human. This study investigated the insolation and solar radiation in Kaohsiung city. Solar radiation on the horizontal and declined plane was calculated. Sun shadow model for urban buildings was constructed for computing accumulated sunshining hours. Horizontal and vertical building shadows were displayed in ArcGIS ¡V the GIS software. Raster-based data model was used to analyze the effect of sun shadow shading by neighbour buildings. And the effect of shadow shading for solar water heater was also investigated. According to the results, minor installation error of orientation and decline angles of solar panel will not cause major energy loss. And the distance between the buildings¡Bthe height difference and the orientation between buildings are most important factors which affect optimal installation location of the solar water heater. If there are buildings located to the south, southeast and southwest, and the stories difference between buildings is over three, the installing location should be moved toward north. If buildings are next to each others and the variation of height is large, the efficient of receiving solar radiation will be deteriorated. The larger is the distance between buildings, the better the energy received.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Στην διπλωματική αυτή εργασία παρουσιάζονται οι πτυχές σχετικά με τον έλεγχο του φωτισμού στα θερμοκήπια με τη χρήση των φακών Fresnel ως διαφανή καλύμματα καθώς και τα αποτελέσματα του συνδυασμού των γραμμικών φακών Fresnel με θερμικά (Τ), φωτοβολταικά (PV) ή υβριδικά φωτοβολταϊκά/θερμικά (PV/T) συστήματα μετατροπής της πλεονάζουσας ηλιακής ακτινοβολίας εντός του θερμοκηπίου σε ηλεκτρική ενέργεια και θερμότητα. Τα συστήματα αυτά μελετούνται σχετικά με την απόδοσή τους στην κάλυψη των θερμικών και ηλεκτρικών αναγκών μιας χαρακτηριστικής θερμοκηπιακής μονάδας, δίνοντας κατ / We present aspects and results concerning irradiation control in greenhouses by using glass type fresnel lenses as transparent covering material. We also present results of the combination of the fresnel lenses with thermal (T), photovoltaic (PV) or hybrid photovoltaic/thermal (PV/T) type absorbers to convert the surplus of the solar radiation inside the greenhouse into electricity and heat. The suggested systems are studying regarding their performance in covering thermal and electrical needs of a typical greenhouse unit, giving also the estimated benefits.

Tyrimų tikslas – ištirti galimybę panaudoti tiesioginę spinduliuotę džiovinamos medžiagos ir džioviklio įkaitimui džiovinant grūdus Lietuvos sąlygomis . Lietuvoje nuimtų grūdų drėgnumas dažniausiai viršija kondicinį, todėl siekiant išvengti kokybės nuostolių juos būtina nedelsiant konservuoti. Darbe apžvelgti grūdų fizinių savybių pokyčiai džiovinimo metu, plačiau analizuojama tiesioginės saulės spinduliuotės panaudojimas Lietuvos sąlygomis džiovinant grūdus su saulės kolektoriais. Ištirtas tiesioginės saulės spinduliuotės poveikis grūdams ir džioviklio paruošimui. Nustatyta, kad tiesioginė saulės spinduliuotė sutrumpina grūdų džiovinimo laiką ir sutaupo energiją naudojamą grūdų džiovinimui. Nustatyta saulės kolektoriaus pasvirimo kampo priklausomybė nuo spindulių kritimo kampo, džiovinimo greičio priklausomybė nuo oro filtracijos greičio ir grūdų drėgnio. / Purpose of the study - research the possibility of using direct solar radiation to heat desiccant material and siccative when drying grain in Lithuanian weather conditions. In Lithuania, humidity of harvested grain is generally higher than conditioned. To avoid loss of quality grain should be cured immediately. This paper reviews changes in physical properties of grain during drying. A wider analysis of use of solar collectors for drying grain in Lithuania using direct solar radiation is also given. Direct solar radiation impact on grain and preparation of dryer has been investigated. It has been found that direct solar radiation reduces the drying time and lowers energy costs when drying grain. Dependence of solar collector tilt angle and solar radiation incidence angle was established. Drying speed relation to air filtration rate and grain moisture has also been found.

Agricultural scientists are faced with the challenge of producing enough food for the increasing world population. Hence the need to develop tools for managing soil and plant systems to increase food production in order to meet the world food demand in the future. Crop simulation models have become promising tools in predicting yield and related components fi'om a set of weather, soil, plant and management data inputs. This study describes the estimation of solar radiant density, a crucial input in crop simulation models; calibration and validation of a soil-plant growth simulator, CropSyst, for management purposes; and generation of weather data for assessment of crop production under possible climate changes in the future. Daily solar radiant density, an input required by most crop simulation models, is infiequently observed in many stations. This may prevent application of crop simulation models for specific locations. Long-term data records of daily minimum and maximum air temperatures, precipitation, sunshine hours and/or solar radiant density were obtained for Cedara, Durban, Seven Oaks and Ukulinga in KwaZulu-Natal, South Africa. Solar radiant density was estimated fi'om sunshine hours using the Angstrom equation and ten other models that involved daily minimum and maximum air temperatures and/or precipitation along with extratelTestrial radiant density. Coefficients for the Angstrom equation and one of the other ten models were specifically developed for South African conditions; the remaining models required fitting coefficients using the available data for all locations. The models were evaluated using (i) conventional statistics that involved, root mean square elTor (RMSE) along with its systematic and unsystematic components, slope, intercept, index of agreement (d), and coefficient of determination (R\ and (ii) a fuzzy expert system that involved a single modular indicator (Ira d) aggregated from the modules of accuracy (aggregation of the indices relative RMSE, model efficiency and I-student probability), con'elation (Pearson's correlation coefficient) and pattem (aggregation of pattem index vs day of year and pattem index vs minimum air temperature). For each index, two functions describing membership to the fuzzy subsets Favourable (F) and Unfavourable (V) were defined. The expelt system calculates the modules according to both the degree of membership and a set of decision rules. Solar radiant density estimated from sunshine hours for the Durban station resulted in R2 , RMSE (MJ m,2) and d index of 0.90, 2.32 and 0.97 respectively. In the absence of observed solar radiant density data, estimations from sunshine hours were used for derivation of coefficients as well as evaluation of the models. For Durban, the performance of the models was generally poor. For Cedara, Seven Oakes and Ukulinga two of the models resulted in a high d index and smallest systematic RMSE. The solar radiant density estimated from each model was also used as an input to simulate maize grain yields using the soil-plant growth simulator, CropSyst. The models were ranked according to their ability to simulate grain yields that match those obtained from using the observed solar radiant density. The rankings according to crop simulation, conventional statistics and expert system were compared. The CropSyst model was also evaluated for its ability to simulate crop water-use of fallow and cropped (oats, Italian ryegrass, rye and maize) plots at Cedara, KwaZulu-Natal, South Africa. Soil characteristics, initial soil water conditions, irrigation and weather data were inputted to CropSyst. Crop input parameters for oats, Italian ryegrass and rye were used, with little modifications, as determined from field experiments conducted at Kromdraai open cast mine, Mpumalanga province, South Africa. Crop input parameters for maIze were either determined fi'om field experiments or taken from CropSyst crop input parameters documentation and adjusted within a narrow specification range of values as dictated by CropSyst. The findings indicated that CropSyst was generally able to simulate reasonably well the water-use of fallow and cropped (oats, Italian ryegI°ass, rye and maize) plots; leaf area index and crop evapotranspiration of rye; and grain yield and developmental stages of maize. The validated CropSyst model was also used to simulate timing and amount of irrigation water, and investigate incipient water stress in oats, Italian ryegrass and rye. The CropSyst model was used to investigate potential effects of future climate changes on the productivity of maize grain yields at Cedara, KwaZulu-Natal, South Africa. The effect of planting date (local planting date, a fortnight earlier and a fortnight later) was also included in the study. A 30-year baseline weather data input series were generated by a stochastic weather generator, ClimGen, using 30 years of observed weather data (l971 to 2000). The generated weather data series was compared with the observed for its distributions of daily rainfall and wet and dry series, monthly total rainfall and its variances, daily and monthly mean and variance of precipitation, minimum and maximum air temperature, and solar radiant density. Four months of the year failed to reproduce distributions of wet and dry series, daily precipitation, and monthly variances of precipitation of the observed weather data series. In addition, Penman-Monteith reference evaporation (ETa) was calculated using the observed and generated data series. Cumulative probability function of ETa calculated using the generated weather data series followed the observed distribution well. Moreover, maize grain yields were simulated using the generated and observed weather data series with local, a fortnight earlier and a fortnight later planting dates. The mean simulated grain yields for the respective planting dates were not statistically different from each other; the grain yields simulated using the generated weather data had significantly smaller variance than the grain yields simulated using the observed weather data series. When the generated weather data series was used an input, the early planting date as compared to the locally practiced and late planting dates resulted in significantly greater simulated grain yields. The grain yields simulated using the observed weather data for the early and local planting dates were not statistically different from each other. The baseline period was modified by synthesized climate projections to create future climatic scenarios. The climate changes considered corresponded to doubling of [C02] from 350 to 700 ~t1 ,-I without air temperature and water regime changes, and doubling of [C02] accompanied by increases in mean air temperature and precipitation changes of 2 (lC and 10%, 2 (le and 20%>, 4 °c and 10%, and 4 (lC and 20% respectively. Solar radiant density was also estimated from daily air temperature range for all scenarios that involved change in mean air temperature. In addition, input crop parameters of radiation-use and biomass transpiration efficiencies were modified for maize, in CropSyst, to accommodate changes in elevated levels of [C02]. Equivalent doubling of [C02], without air temperature or water regime changes, resulted in increased simulated grain yields as compared to the baseline period. Adding 2 QC to the mean daily temperature and 10% to the daily precipitation of a [C02] elevated atmosphere reduced the grain yield but still kept it above the level of the baseline period grain yield. Adding 4 QC to the mean daily temperature and 10% to the daily precipitation fLllther decreased the yield. Increasing the daily precipitation by 20% instead of 10% did not change the simulated grain yield as compared to the 10% increments. Early planting date, for all scenarios, also resulted in higher yields, but the relative increment in grain yield was higher for the late planting dates with scenarios that involved increment in mean air temperature. In general, this study confi1l11ed that doubling of [C02] increases yield but the accompanied increase in mean air temperature reduces yield. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.