180 resultados para Descarga atmosférica


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This study aims to analyze the relationship between deforestation in the highlands of the São Francisco River Basin over the past 45 years due to agricultural activities and livestock , and the observed changes in the dynamics of the same river in the Pantanal of Mato Grosso , as sinuosity , discharge sediment , flow, points of erosion and morphological changes . It is observed that deforestation occurs in the plain and on the plateau , however with much more intensity in the latter, provided the extensive land use in the region . Thus, the study aims to contribute to a better understanding of the relationships between the uplands and flood plains . To achieve this goal will be used proper methods of geomorphological and geological sciences , with emphasis on the use of satellite imagery and hydrological data side . The research will include the following steps : I) literature review ; II) characterization geomorphological , geological , hydrological and climate , III) Dynamics of vegetation ; IV) Analysis of cause-effect relationships in the river system . Product analysis will suggest preventive measures to minimize the effects caused by the practices of use and occupation in the study area, as well as other regions suffer the same impacts

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Increasingly, people searches for an efficient and economic way for transporting bulk materials. Transport through belts is now the most widely used mean for transporting bulk materials, used by companies from various sectors such as mining, quarrying, agribusiness, etc. There are many advantages of using a conveyor belt as compared to rail or by truck. Trucks needs a driver, have a high risk of accidents as well as a high cost for maintenance and as well as trains, after making the downloading of the material, return empty to the next load. The cost for the construction of a railway is very high, making it often impossible. The conveyor belt have a high cost of installation, but it works 24 hours a day, 365 days a year. The upper side of the belt is always loaded, the maintenance cost is average and the risk of accidents is low, causing it to be the ideal way to transport bulk materials. This monography aims to interest the reader about what is a conveyor belt, what are its main components and demonstrate the basic calculations for their sizing and selection of components. Throughout the work, scaled a belt conveyor for use in the mining sector, but the concepts demonstrated apply to the transport of any material

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The concentration of metal pollutants such as lead (Pb), has grown and developed in populated areas due to pollution and other human activities. Consequently, the potential for achieve this element food chain has also increased. Lead is very toxic to humans, especially to children, and exposure to lead can cause adverse health effects mainly on human nervous system, bone marrow and kidneys, interfering with chromosomal or genetic processes. This paper presents an overview of the main aspects related to environmental contamination by lead from battery plants. The assessment of an area contaminated by lead in Bauru-SP next a battery factory was reported in this work as well as the entire history of monitoring, classification and application of processes applied by CETESB since 2002. Analyzing the issue in its economic aspects, we found that the degradation of the environment is directly related to the development model adopted by the capitalist system, which is based on the law of supply and demand for products and services. The data presented indicate that Brazil still needs a broader policy where government agencies, industries and population through awareness can be united for the same purpose: to preserve life

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The climate is one of the main elements of the natural environment that governs the life of man. Specific conditions of temperature, humidity, light, wind and precipitation have direct influence on physiological conditions that man needs to survive and more than that, besides the influence on human and animal physiology, the climatic elements are also responsible for a significant portion of economic activities such as industry, agriculture, commerce, transportation, and others. Therefore, any change in weather patterns has great impact on daily activities, and even more in urban sites, where the most of population is concentrated nowadays. Based on this discussion and concerned in understand the atmospheric structure, this monograph intends to analyze the pattern of atmospheric and temperature element in seven cities of small and medium size located in the state of São Paulo countryside... (Complete abstract click electronic access below)

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In this work concepts of flammability limits of anhydrous and hydrated ethanol to pressures below atmospheric, using the Dalton model for gaseous mixtures. Theoretical and experimental methods for determining the boundaries and the influence of parameters such as concentration, temperature and pressure were introduced. Analyzes from partial pressures of fuel vapor and correlations with temperature and total pressure were made. Finally presents an overview of aviation fuels, their requisites and trends in the use of biofuels in commercial aviation industry

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The Urucuia Aquifer System represents a strategic water source in western Bahia. Its baseflow is responsible for the flow rate of the main tributaries of São Francisco river left bank in the dry season, including the Rio Grande, its main tributary in Bahia state. This river has a hydrological regime heavily affected by groundwater and is located in a region with conflicts about water resources. The aquifers geology is constituted by neocretacious sandstones of Urucuia Group subdivided in Posse Formation and Serra das Araras Formation. The embasement is formed by neoproterozoic rocks of Bambuí Group. This work focuses on an important tool application, the mathematical model, whose function is represent approximately and suitably the reality so that can assist in different scenarios simulations and make predictions. Many studies developed in this basin provided the conceptual model basis including a full free aquifer, lithological and hydraulical homogeneity in entire basin, null flux at plateau borders and aquifer base. The finite element method is the numerical method used and FEFLOW the computational algorithm. The simulated area was discretized in a single layer with 27.357,6 km² (314.432 elements and 320.452 nodes) totaling a 4.249,89 km³ volume. Were utilized 21 observation wells from CERB to calibrate the model. The terrain topography was obtained by SRTM data and the impermeable base was generated by interpolation of descriptive profiles from wells and electric vertical drilling from previous studies. Works in this area obtained mean recharge rates varying approximately from 20% to 25% of average precipitation, thus the values of model recharge zones varying in this range. Were distributed 4 hydraulic conductivity zones: (K1) west zone with K=6x10-5 m/s; (K2) center-east zone with K=3x10-4 m/s; (K3) far east zone with K=5x10-4 m/s; e (K4) east-north zone with K=1x10-5 m/s. Thereby was incorporated to the final conceptual model...

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The use of biomass as an energy source has been increasing in Brazil, with emphasis on the use of wood biomass, such as bark, wood chips and sawdust, that after receiving the appropriate treatment can be used in burners for power generation. However, from this burning are emitted fine particles known as particulate matter and a wide range of toxic organic and inorganic components in the form of gases that contribute greatly to air pollution and global warming, affecting human health, the environment and climate. The objective of this project was the quantification of gaseous and particulate, using and evaluating the equipment DR4000 ( Dataram 4 ) sampling of particulates smaller than 2.5μm and EUROTRON ( Ecoline 4000 ) when sampling gaseous pollutants, emitted from the burning of biomass in real time in the firing burner to a chimney attached biomass . We note that there are no specific rules that establish emission limits for particulate matter with diameter less than 2.5μm that are most harmful to human health and the highest concentrations reached about 800000μg/m3, for smaller diameters. It is noticeable the need for sampling of pollutants especially in industries that use biomass to fuel that could be implanted emission control equipment

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The Brazilian government has convinced the world that ethanol deriving from sugar cane is a promissory means of sustainable fuel for vehicles. There is a great growth of ex vehicles , i.e, run both by ethanol and gasoline, due to competent automotive industries and e cient alcohol production technology. In 2009 and 2010 the ethanol production was 25.7 billion liters and 53.8% of sugar cane production was destined to alcohol production. Nevertheless, the sugar production also derived from sugar cane should increase in 2011. Brazil produced 33 million tons of sugar in the last harvest. With sugar cane on the rise production is arising new environmental problems. The harvest using mechanized cut besides improving the logistic transportation system leaves the generating residue in the eld. This residue is a mixture of straw, leavings and scrap of sugar cane named sugar cane crop residue and corresponds to 30% of biomass and can be burned and produce electricity by cogeneration. But the transport the sugar cane crop from the eld is expensive due costs involved in the transport system. This work aims to propose a formulation for the bales collecting problem from sugar cane eld to mill that minimize the costs involved in the transport system. The computational tests use the C++ language and an algorithm based on genetic algorithms techniques

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This Graduate Work aims to exhibit the analyze of the applicability of LED technology in a real outdoor lighting situation, and this project’s illumination solution is compared with the initial proposal, the sodium vapor lamps. What is studied is an outdoor area, like the roads and parking lots of a plant. A light planning software is used for this comparison, and the results are displayed instantly, allowing rapid analysis of the project through a simulation. The medium illuminance is the same in both solutions for this case study and minimum rates set as standard were observed then the analysis are appropriate in this project. Various aspects are considered in order to obtain a comprehensive analysis of this project, such as economic, environmental and quality of lighting. LED technology in outdoor lighting is presented in its infancy, but promising. Solid state lamps show great advantages when compared with other technologies, such as discharge lamps, however there are some disadvantages tied to new products that are expected to be overcome with technological development and increased production

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Environrnental issues are in focus lately, mainly due to climate change that have been registered in recent decades. Some of these changes are attributed to the increased atmospheric concentration of greenhouse gases induce, main1y due to anthropogenic emissions. These gases act by absorbing heat in the form of electromagnetic radiation emitted by the planet, and after a time interval, reissuing such radiation in various directions, including back to the surface, causing overheating of the same. Projections indicate that climate change wiIl tend to increase even more. Because of this, in recent years a number of studies are being conducted on the dynamics of inducers of greenhouse gases, especially C02, because that is primarily responsible for the development of that phenomenon. To better understand the flow of C02 are studied specific areas, as regions bordering the forests, soils that are under preparation for agriculture, urban areas, among others. Forests are an important sink for C02, because during the process of photosynthesis, this molecule is captured and used to obtain glucose. Thus, studies of the regions bordering the forests contribute enough to the understanding of the dynamics of C02. Because it requires a large amount of factors, the concentration of CO2 in a given location is very variable and this makes it much more difficult to understand their dynamics and, consequently, the action of the enhanced greenhouse effect. Being a relatively new area of study, there are many controversies about the consequences of the greenhouse effect, so that the community does not believe that climate change resulting from human action. According to them, such changes are merely natural phenomena and periodicals

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The aim of this work was the development a computer code for simulation and analysis of atomic spectra from databases constructed from the literature. There were created four routines that can be useful for spectroscopic studies in the atomic processes of laser isotope separation. In the first routine, Possible Transitions, the program checks the possible electron transitions from an energy level of the atom present in the database considering the selection rules for an electric dipole transition. The second routine, Locator Transitions, checks the possible electronic transitions within a user-specified spectral region. The routine Spectra Simulator creates simulated spectra using the graphical application gnuplot through lorentzian curve and finally, the routine Electronic Temperature determines the temperature of electronic excitation of the atom, thought the Boltzmann Plot Method. To test the reliability of the program there were obtained experimental emission spectra of a hollow cathode discharge of dysprosium and argon as a buffer gas. The hollow cathode discharge has been subjected to different values of operating currents and pressure of inert gas. The spectra obtained were treated with the assistance of program routines developed (Transition Locator and Spectra Simulator) and temperatures electronic excitation of the atoms of dysprosium in the different discharge conditions were calculated (routine Electronic Temperature). The results showed that the electronic excitation temperature of the neutral dysprosium atoms in the hollow cathode discharge increases with increasing current applied to the cathode and also by increasing the gas pressure buffer. The determination coefficients, R2, obtained by the Electronic Temperature routine using the linear adjust of the Boltzmann Plot Method were greater... (Complete abstract click electronic access below)

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The growing demand for electricity in Brazil has stimulated the implementation of Small Hydro Power (PCH) in various regions of the country. However, the silting of reservoirs is a major problem faced by power plants and power plants. In this context, this study aimed to evaluate the data hydrosedimentological strategic points of the watershed of the Alto Rio Sucuriú (MS) to identify the possible causes siltation of the reservoir PCH Costa Rica and suggest mitigation measures. Hydrosedimentological surveys were conducted during the rainy season (February / March 2012) and drought (August 2012), and obtained data flow, discharge liquid, suspended solids and bottom and organic matter content. Based on these results it was determined that the points 2, 4, 7 and 9 are the largest contributors to sedimentation, and point 4 got most liquid discharge (38,20 m3s-1), point 7 largest discharge of solid suspension (906,3 mg L-1), points 2 and 4 major discharges solid totals (231,59 t dia-1 and 238,185 t dia-1 respectively) and point 9 higher organic matter content (22,18%) . Found greater fraction of fine sand and very fine suspended solids and solid medium sand in the background. As mitigation measures for the process of silting of the reservoir PCH Costa Rica (MS) highlights the orientation of landowners in adopting conservation measures and planting of leguminous species native to the region in symbiosis with nitrogen-fixing bacteria

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Air pollution is an environmental issue worldwide and frequently cause negative effects on population health and ecosystems on cities. The relationship between climate and atmospheric pollution can be used as a surrogate to the intensity of air pollution. The present and quantity of some gases can be used as indicators to air quality: particulate matter (PM), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and nitrogen dioxide (NO2). Among those gases, CO has its major source within the cities, where automobiles are the main emitter. But measure pollutant concentration are challenging, sometimes because the lack of good equipments due to high costs and of the large variability of models that varies in precision, way of measure and distribution of sellers. Modeling are useful when there are an intend to evaluate air pollution, its sources and evaluate scenarios. This work aims to use CAL3QHCR model developed by the U.S Environmental Protection Agency (EPA) to generate predictive surfaces of CO concentration distribution on a site within Campinas city, located in São Paulo state, Brazil. CAL3QHCR model use data urban automobile circulation to generate spatial results for CO distribution. We observed that the pollution concentration was lower on our modeling than the concentrations measured by Companhia Ambiental do Estado de São Paulo (CETESB), the main environmental company on the São Paulo state. Also the correlation between average estimates of our model and the measure by CETESB was weak, indicating that the model used on this study need to be or better parameterized, or the scale we measured of CO emissions need to be rescaled. Although the model failed to correlate to CETESB data, maybe one that explore the estimated emissions distributed within the sites to understand spatial distributions of CO on the regions. Also, the generated information can also be used to other studies, and come to be useful to explain heat island

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Pós-graduação em História - FCLAS