Balanço de energia de fluxo de CO2: cerrado da floresta estadual de Assis

Based on climatological data and energy flow, this paper analyzes the behavior observed in microclimatic an important remnant of cerrado in the São Paulo State. The seasonal climate is well marked, in the study area, with two climatic periods (one dry and one wet). The vegetation presents physiology as a function of water availability and the local thermal conditions and can be seen marked changes in the landscape due to the more or less presence of solar radiation. It’s important to understand the ecosystems behave in the context of global change. It has gained the attention of many researchers in the world.

Equilíbrio térmico e emissão de metano em vacas Jersey

Pós-graduação em Zootecnia - FCAV

Análise espacial do potencial fotovoltaico em telhados de residências usando modelagem hierárquica bayesiana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação de métodos de estimativa da evapotranspiração de referência para região de Jaboticabal-SP

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Brazilian consensus on photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection.

Evolução diurna e anual da frequência das coberturas de céu em Botucatu/SP

This work presents an analysis of the pattern variation of the sky conditions in Botucatu/SP. The classification was based on the clarness index KT. It was used in the classification a database of global solar irradiance in the horizontal, measured at Radiometric Station of UNESP in Botucatu (latitude 22.85°S, longitude 48.43°W, altitude 786 m) from 1996 to 2005. We analyzed the variations in frequency, during the photoperiod and over the year, of the sky conditions: I - Cloudy (KT < 0.35); II - party cloudy with dominance for the diffuse (0.35 < 0.55 < KT)) III - party cloudy with dominance for the clear (0.55 < KT < 0.65) and IV - clear (KT > 0.65). The frequency of sky conditions I and II are higher during the rainy season of the year and in hours close to sunrise and sunset. And it is lower during the dry season an in hours near noon, in wich there is a predominance of sky conditions III and IV. The monthly hourly frequency of sky condition I ranged from 46,91% of the photoperiod in January to 25.27% in August. And the frequency monthly daily ranged from nine days in January to three days in August. To the sky condition IV, the frequency monthly hourly ranged from 38.81% of the photoperiod in August to 18.17% im January. And the frequency monthly daily ranged from 17 days in August to three days in January.

Aplicação da teoria fuzzy no controle de sistemas de geração de energias alternativas

This paper presents the application and use of a methodology based on fuzzy theory and simulates its use in intelligent control of a hybrid system for generating electricity, using solar energy, photovoltaic and wind. When using a fuzzy control system, it reached the point of maximum generation of energy, thus shifting all energy generated from the alternative sources-solar photovoltaic and wind, cargo and / or batteries when its use not immediately. The model uses three variables used for entry, which are: wind speed, solar radiation and loading the bank of batteries. For output variable has to choose which of the batteries of the battery bank is charged. For the simulations of this work is used MATLAB software. In this environment mathematical computational are analyzed and simulated all mathematical modeling, rules and other variables in the system described fuzzy. This model can be used in a system of control of hybrid systems for generating energy, providing the best use of energy sources, sun and wind, so we can extract the maximum energy possible these alternative sources without any prejudice to the environment.

Estimativas da radiação difusa horária incidente em superfícies inclinadas com base na transmissividade atmosférica

Evaluated statistical equations estimates (based on radiometric fractions) of the hourly diffuse radiation incident on inclined surfaces for the North to 12.85, 22.85 and 32.85°, the climate and geographical conditions of Botucatu, SP. The database was generated from April/1998 to December/2007, with measures in the three tilted surfaces in different periods, but concomitant to the horizontal plane. In the validation of the equations were used indicative statistics MBE (mean absolute error), RMSE (square root mean square error) and index adjustment (d) for three inclinations and conditions of sky coverage. The increased angle of inclination of the surface led to increased scattering of hourly values for the coefficient of atmospheric transmissivity of diffuse radiation for inclined and horizontal surfaces. Estimates of diffuse radiation on the basis of hourly tilted horizontal global radiation occur for quadratic polynomial models, which adjust K'Dβ maximum values of between 0.14 and 0.30 for winter and summer when KTH varies between 0.40 and 0.66, indicating that energy, the highest values of diffuse radiation occur in partly cloudy sky conditions and / or partially open. The increase in atmospheric transmissivity decreases the performance of annual and monthly equations at all inclinations.

Avaliação da qualidade térmica de espaços de transição do tipo linear externo

Pós-graduação em Arquitetura e Urbanismo - FAAC

Yield potential and resource-use efficiency of maize systems in the western U.S. Corn Belt

Maize demand for food, livestock feed, and biofuel is expected to increase substantially. The Western U.S. Corn Belt accounts for 23% of U.S. maize production, and irrigated maize accounts for 43 and 58% of maize land area and total production, respectively, in this region. The most sensitive parameters (yield potential [YP], water-limited yield potential [YP-W], yield gap between actual yield and YP, and resource-use efficiency) governing performance of maize systems in the region are lacking. A simulation model was used to quantify YP under irrigated and rainfed conditions based on weather data, soil properties, and crop management at 18 locations. In a separate study, 5-year soil water data measured in central Nebraska were used to analyze soil water recharge during the non-growing season because soil water content at sowing is a critical component of water supply available for summer crops. On-farm data, including yield, irrigation, and nitrogen (N) rate for 777 field-years, was used to quantify size of yield gaps and evaluate resource-use efficiency. Simulated average YP and YP-W were 14.4 and 8.3 Mg ha-1, respectively. Geospatial variation of YP was associated with solar radiation and temperature during post-anthesis phase while variation in water-limited yield was linked to the longitudinal variation in seasonal rainfall and evaporative demand. Analysis of soil water recharge indicates that 80% of variation in soil water content at sowing can be explained by precipitation during non-growing season and residual soil water at end of previous growing season. A linear relationship between YP-W and water supply (slope: 19.3 kg ha-1 mm-1; x-intercept: 100 mm) can be used as a benchmark to diagnose and improve farmer’s water productivity (WP; kg grain per unit of water supply). Evaluation of data from farmer’s fields provides proof-of-concept and helps identify management constraints to high levels of productivity and resource-use efficiency. On average, actual yields of irrigated maize systems were 11% below YP. WP and N-fertilizer use efficiency (NUE) were high despite application of large amounts of irrigation water and N fertilizer (14 kg grain mm-1 water supply and 71 kg grain kg-1 N fertilizer). While there is limited scope for substantial increases in actual average yields, WP and NUE can be further increased by: (1) switching surface to pivot systems, (2) using conservation instead of conventional tillage systems in soybean-maize rotations, (3) implementation of irrigation schedules based on crop water requirements, and (4) better N fertilizer management.

Yellowstone Super-Volcano: Evalutaion, Potential Threats, and Possible effects on Nebraska Citizens Health and Prosperity

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.

The effects of river discharge and seasonal winds on the shelf off southeastern South America

The Rio de la Plata waters form a low salinity tongue that affects the circulation, stratification and the distributions of nutrients and biological species over a wide extent of the adjacent continental shelf. The plume of coastal waters presents a seasonal meridional displacement reaching lower latitudes (28,S) during austral winter and 32 degrees S during summer. Historical data suggests that the wind causes the alongshore shift, with southwesterly (SW) winds forcing the plume to lower latitudes in winter while summer dominant northeasterly (NE) winds force its southward retreat. To establish the connection between wind and outflow variations on the distribution of the coastal waters, we conducted two quasi-synoptic surveys in the region of Plata influence on the continental shelf and slope of southeastern South America, between Mar del Plata, Argentina and the northern coast of Santa Catarina, Brazil. We observed that: (A) SW winds dominating in winter force the northward spreading of the plume to low latitudes even during low river discharge periods; (B) NE winds displace the plume southward and spread the low salinity waters offshore over the entire width of the continental shelf east of the Plata estuary. The southward retreat of the plume in summer leads to a volume decrease of low salinity waters over the shelf. This volume is compensated by an increase of Tropical waters, which dominate the northern shelf. The subsurface transition between Subantarctic and Subtropical Shelf Waters, the Subtropical Shelf Front, and the subsurface water mass distribution, however, present minor seasonal variations. Along shore winds also influence the dynamics and water mass variations along the continental shelf area. In areas under the influence of river discharge, Subtropical Shelf Waters are kept away from the coastal region. When low salinity waters retreat southward, NE winds induce a coastal upwelling system near Santa Marta Cape. In summer, solar radiation promotes the establishment of a strong thermocline that increases buoyancy and further enhances the offshore displacement of low salinity waters under the action of NE winds. (C) 2008 Elsevier Ltd. All rights reserved.

Photo-induced toxicity of anthracene in the Antarctic shallow water amphipod, Gondogeneia antarctica

The photo-induced toxicity of anthracene was investigated as the mortality in Antarctic shallow water amphipod, Gondogeneia antarctica, at different concentrations of anthracene and different periods of exposure to natural sunlight and artificial UVA and UVB radiations. When exposed to natural sunlight, animals contaminated in the dark and placed in clean water or in anthracene solutions showed different degrees of mortality, dose-time dependent. Effects were even more evident when these animals were exposed to artificial UVA or UVB radiations. Depuration seemed to be a slow process. The effects of UV radiation and anthracene alone and the effects of the interactions of these two stressors implied that solar radiation is an important parameter that deserves consideration in the environmental assessment of polycyclic aromatic hydrocarbons in Antarctic coastal waters. G. antarctica proved to be a good bioindicator for the phototoxicity of anthracene in Antarctic shallow waters.

Dry matter production of Tanzania grass as a function of agrometeorological variables

The objective of this work was to develop and validate linear regression models to estimate the production of dry matter by Tanzania grass (Megathyrsus maximus, cultivar Tanzania) as a function of agrometeorological variables. For this purpose, data on the growth of this forage grass from 2000 to 2005, under dry-field conditions in Sao Carlos, SP, Brazil, were correlated to the following climatic parameters: minimum and mean temperatures, degree-days, and potential and actual evapotranspiration. Simple linear regressions were performed between agrometeorological variables (independent) and the dry matter accumulation rate (dependent). The estimates were validated with independent data obtained in Sao Carlos and Piracicaba, SP, Brazil. The best statistical results in the development and validation of the models were obtained with the agrometeorological parameters that consider thermal and water availability effects together, such as actual evapotranspiration, accumulation of degree-days corrected by water availability, and the climatic growth index, based on average temperature, solar radiation, and water availability. These variables can be used in simulations and models to predict the production of Tanzania grass.

MATHEMATICAL ANALYSIS OF MAXIMUM POWER GENERATED BY PHOTOVOLTAIC SYSTEMS AND FITTING CURVES FOR STANDARD TEST CONDITIONS

The rural electrification is characterized by geographical dispersion of the population, low consumption, high investment by consumers and high cost. Moreover, solar radiation constitutes an inexhaustible source of energy and in its conversion into electricity photovoltaic panels are used. In this study, equations were adjusted to field conditions presented by the manufacturer for current and power of small photovoltaic systems. The mathematical analysis was performed on the photovoltaic rural system I- 100 from ISOFOTON, with power 300 Wp, located at the Experimental Farm Lageado of FCA/UNESP. For the development of such equations, the circuitry of photovoltaic cells has been studied to apply iterative numerical methods for the determination of electrical parameters and possible errors in the appropriate equations in the literature to reality. Therefore, a simulation of a photovoltaic panel was proposed through mathematical equations that were adjusted according to the data of local radiation. The results have presented equations that provide real answers to the user and may assist in the design of these systems, once calculated that the maximum power limit ensures a supply of energy generated. This real sizing helps establishing the possible applications of solar energy to the rural producer and informing the real possibilities of generating electricity from the sun.