964 resultados para Global solar radiation estimation inside polyethylene greenhouses from the sunshine duration
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The present paper deals with numerical corrections factors proposed as a function of the clearness index in order to correct the diffuse solar irradiance measured with the Melo-Escobedo Shadowring Measuring Method (ME shadowring). The global irradiance was measured by an Eppley - PSP pyranometer ; direct normal irradiance by an Eppley-NIP pyrheliometer fitted to a ST-3 sun tracking device and the diffuse irradiance by an Eppley-PSP pyranometer fitted to a ME shadowring. The validations were performed by the MBE and RMSE statistical indicators. The results showed that the numerical correction factors were appropriate to correct the shadowring diffuse irradiance.
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The present study was developed in Departamentos de Engenharia Rural e Morfologia e Fisiologia Animal da FCAV/Unesp. The objective of evaluating different roof slopes and exposure in three types of coverage in models of animal installations. Project 48 built reduced models of wood were used with dimensions of 1,00 x 1,00 x 0,50 meters. The covering was one water, lateral and wood floor, disposed in the exhibitions North-south, being 24 prototypes in the north exhibition and 24 in the south. Were used in the covering roofs of ceramic type, galvanized steel and asbestos. The slopes varied of 20, 30, 40 and 50% for ceramic tile and 10, 30, 40 and 50% for the others and with two repetitions for slope. Inside the reduced models temperature readings were accomplished, of hour in hour during one year, for the system of acquisition of Data Logger Campbell Scientific-Ínc and externally the temperature of the air, incident radiation global solar, precipitation, speed and relative humidity of the air were measured. The results obtained during the experimental period of one year were appraised statistically for the statistical package SAS in the factorial outline, where three factors were considered: tile type, slope degree and exposure. The obtained averages were compared through the test of Tukey to 5% of probability. After analyzing the data we found that with increasing slope, there was a decrease in inside temperature in the cover prototypes, therefore, using steeper slopes with 50% of tipping ceramics and asbestos, with greater coverage on display South, we have lower temperatures in poultry houses in the geographic coordinates of the city of Jaboticabal.
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Estimating equations of global radiation based on the sunshine duration were proposed for horizontal surface and with inclination of 12.85, 22.85 and 32.85° facing the North in Botucatu, SP, Brazil, in monthly, seasonal and annual groupings of data. Simple linear correlations were applied (for definition of the linear and angular coefficients of Angstrom-Prescott model), in a database measured in all three inclinations in different periods (22.85°: 04/1998 to 07/2001; 12.85°: 08/2011 to 02/2003; and 32.85°: 03/2003 to 12/2007) concomitant with horizontal measures and sunshine duration. The statistical performance of the model was analysed by the means absolute error (MBE), the square root of the mean square error (RMSE) and the index adjustment (d). The minimum global radiation transmissivity varied from 14.35% in August (12.85°) to 27.86% in December (32.85°) and the maximum transmissivity ranged between 62.10% and 78.90%, for June (32.85°) and December (12.85°). Increasing the angle of inclination surface increased the scattering and decreased the index of adjustment and performance. The worst results were found for application of the seasonal and annual models in the months of autumn and winter for 32.85° (RMSE below 42.93% and adjustment superior to 0.4693).
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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A avaliação da influência da exclusão da precipitação sobre a variação na produção de liteira foi realizada na Reserva Florestal de Caxiuanã – Estação Científica Ferreira Penna (1º 42' S, 51º 31' W) durante o período de março de 2001 a fevereiro de 2003, com o objetivo de identificar as principais variáveis meteorológicas e do balanço hídrico mensal que afetaram a produção e decomposição de liteira. Este trabalho foi parte do subprojeto EXPERIMENTO DE SECA NA FLORESTA (ESECAFLOR), que tinha o objetivo de estudar o impacto de seca prolongada na floresta nos fluxos de água, energia e dióxido de carbono na floresta amazônica. A sazonalidade na produção de liteira e de seus componentes (folhas, gravetos e partes reprodutivas) foi bem estabelecida, com a ocorrência da maior produção de liteira nos meses com menor precipitação. A produção total mensal de liteira variou durante o período experimental, de 294,78 kg.ha-1 a 1758,69 kg.ha-1, com um valor médio de 777,70 kg.ha-1. A produção total de liteira foi distribuída em folhas (61,40 %), gravetos (18,45 %) e partes reprodutivas (20,14 %). Os resultados obtidos na parcela sob condições naturais apresentaram uma maior produção de liteira, aproximadamente 25 %, comparada com a produção de liteira na parcela submetida à exclusão da água de chuva. As variáveis mais fortemente correlacionadas com a produção de liteira e suas componentes foram a velocidade do vento, a densidade de fluxo de radiação solar global, a densidade de fluxo de radiação fotossintéticamente
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Investigamos a estimativa da orientação de fratura; mergulho e direção, através da análise de AVO multiazimutal de ondas qP e de suas convertidas qS1 e qS2. Assumimos fraco contraste de impedância, fraca anisotropia e ainda que, o meio fraturado comporta-se efetivamente como um meio transversalmente isotrópico (TI). Dentro destas hipóteses, a estimativa da orientação de fratura reduz-se a estimativa da orientação do eixo de simetria a partir de dados de refletividade de ondas qP. Aproximações lineares da refletividade da onda qP são utilizadas na inversão.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The aim of this paper is to present an analytical solution for the spin motion equations of spin-stabilized satellite considering only the influence of solar radiation torque. The theory uses a cylindrical satellite on a circular orbit and considers that the satellite is always illuminated. The average components of this torque were determined over an orbital period. These components are substituted in the spin motion equations in order to get an analytical solution for the right ascension and declination of the satellite spin axis. The time evolution for the pointing deviation of the spin axis was also analyzed. These solutions were numerically implemented and compared with real data of the Brazilian Satellite of Data Collection - SCD1 an SCD2. The results show that the theory has consistency and can be applied to predict the spin motion of spin-stabilized artificial satellites.
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This paper reports on an unmodeled, all-sky search for gravitational waves from merging intermediate mass black hole binaries (IMBHB). The search was performed on data from the second joint science run of the LIGO and Virgo detectors (July 2009-October 2010) and was sensitive to IMBHBs with a range up to similar to 200 Mpc, averaged over the possible sky positions and inclinations of the binaries with respect to the line of sight. No significant candidate was found. Upper limits on the coalescence-rate density of nonspinning IMBHBs with total masses between 100 and 450 M-circle dot and mass ratios between 0.25 and 1 were placed by combining this analysis with an analogous search performed on data from the first LIGO-Virgo joint science run (November 2005-October 2007). The most stringent limit was set for systems consisting of two 88 M-circle dot black holes and is equal to 0.12 Mpc(-3) Myr(-1) at the 90% confidence level. This paper also presents the first estimate, for the case of an unmodeled analysis, of the impact on the search range of IMBHB spin configurations: the visible volume for IMBHBs with nonspinning components is roughly doubled for a population of IMBHBs with spins aligned with the binary's orbital angular momentum and uniformly distributed in the dimensionless spin parameter up to 0.8, whereas an analogous population with antialigned spins decreases the visible volume by similar to 20%.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This paper presents the results of a study on the thermal comfort in open urban spaces, undertaken in pedestrian streets located in the three towns, Campinas, Baurú, and Presidente Prudente, in the state of Sao Paulo. The study was developed as part of a more extensive project on thermal comfort in different kinds of open public spaces in Brazil. The methodology involved monitoring the microclimatic variables (air and globe temperature, humidity, air velocity and global solar radiation), and structured interviews, in order to assess the actual thermal comfort through the Actual Sensation Vote (ASV) and the personal users’ variables. The Physiological Equivalent Temperature (PET) was also calculated. The results show different limits for neutral temperature in each city: 20-29ºC for Campinas, 21-30 ºC for Bauru and 14-24 ºC for Presidente Prudente). However, 59.5% of the total sample (308 out of 519 individuals) indicated comfort limits ranging from 18 to 26 ºC, which is consistent with the limits proposed by Monteiro and Alucci for the city of Sao Paulo. These results can contribute to evaluate the thermal quality of other public spaces in the same towns.
Comparação de métodos de estimativa da evapotranspiração de referência para região de Jaboticabal-SP
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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Abstract Yellowstone National Park is located over a hot spot under the North American tectonic plate and holds a potentially explosive super-volcano that has the ability to cause deadly consequences on the North American continent. After an eruption the surrounding region would see the greatest devastation, covered by pyroclastic deposits and thick ash fall exterminating most all life and destroying all structures in its path. In landscapes of greater distance from the event the consequences will be less dramatic yet still substantial. Records of previous eruption data from the Yellowstone super-volcano show that the ash fall out from the eruption can cover areas as large as one million square kilometers and could leave Nebraska covered in ash up to 10 centimeters thick. This would cause destruction of agriculture, extensive damage to structures, decreased temperatures, and potential respiratory hazards. The effects of volcanic ash on the human respiratory system have been shown to cause acute symptoms from heavy exposure. Symptoms include nasal irritation, throat irritation, coughing, and if preexisting conditions are present some can develop bronchial symptoms, which can last for a few days. People with bronchitis and asthma are shown to experience airway irritation and uncomfortable breathing. In most occurrences, exposure of volcanic ash is too short to cause long-term health hazards. Wearing facial protection can alleviate much of the symptoms. Most of the long-term ramifications of the eruption will be from the atmospheric changes caused from disruption of solar radiation, which will affect much of the global population. The most pertinent concerns for Nebraska citizens are from the accumulation of ash deposits over the landscape and the climatic perturbations. Potential mitigation procedures are essential to prepare our essentially unaware population of the threat that they may soon face if the volcano continues on its eruption cycle.
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This study uses the global Ocean Topography Experiment (TOPEX)/Jason-1 altimeters` time series to estimate the 13-yr trend in sea surface height anomaly. These trends are estimated at each grid point by two methods: one fits a straight line to the time series and the other is based on the difference between the average height between the two halves of the time series. In both cases the trend shows large regional variability, mostly where the intense western boundary currents turn. The authors hypothesize that the regional variability of the sea surface height trends leads to changes in the local geostrophic transport. This in turn affects the instability-related processes that generate mesoscale eddies and enhances the Rossby wave signals. This hypothesis is verified by estimates of the trend of the amplitude of the filtered sea surface height anomaly that contains the spectral bands associated with Rossby waves and mesoscale eddies. The authors found predominantly positive tendency in the amplitude of Rossby waves and eddies, which suggests that, on average, these events are becoming more energetic. In some regions, the variation in amplitude over 13 yr is comparable to the standard deviation of the data and is statistically significant according to both methods employed in this study. It is plausible that in this case, the energy is transferred from the mean currents to the waves and eddies through barotropic and baroclinic instability processes that are more pronounced in the western boundary current extension regions. If these heat storage patterns and trends are confirmed on longer time series, then it will be justified to argue that the warming trend of the last century provides the energy that amplifies both Rossby waves and mesoscale eddies.