969 resultados para SULFUR DIFLUORIDE
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Pós-graduação em Ciência e Tecnologia de Materiais - FC
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Pós-graduação em Química - IQ
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Pós-graduação em Microbiologia Agropecuária - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The time, dose and applied nutrients in corn have a direct effect on its productivity. Therefore, the objective was to study the application of N and S in corn as ammonium sulfate, in succession to wheat and oats and evaluate different forms of fertilizer management. The experiment was conducted in a randomized block design in Oxisol (Hapludox). The five treatments with N, at a dose of 120 kg ha(-1) were applied in 20 plots (5x4), according to the management of fertilizer: T1-N (120 kg ha(-1)) full at sowing, T2-N (120 kg ha(-1)) total coverage; T3-N (40 kg ha(-1)) at sowing and N (80 kg ha(-1)) in coverage; T4-N advance in wheat sowing and sowing oats (120 kg ha(-1)), T5-(control). The S doses were corresponding to their concentrations in the fertilizer. Only wheat received a dose of 24 kg N ha(-1) at sowing all plots and oats received 24 kg N ha(-1) at sowing only the portions related to treatment with anticipation of corn N (T4). We evaluated the biomass production of winter crops (oats and wheat), according to the fertilization at sowing, and also the influence of winter crops and management of ammonium sulfate, the corn yield. The oats produced more dry matter in relation to wheat, positively influencing the corn yield, regardless of fertilizer management. The anticipation of ammonium sulfate, the sowing of oats, was favorable to corn yield, equating to other forms of management of fertilizer. Rotation corn and oats, forms management, ammonium sulphate, at seeding, topdressing or applied in split were equally efficient in corn yields.
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In materials science, the search for technological improvements have become one of the main subject of study of researchers. This is especially true in the case of materials with reduced sizes, in the nanometer scale. Important phenomena to be studied in these cases are the desorption and adsorption on two-dimensional materials, such as graphene. These phenomena are of great importance in the study of interactions between organic films, synthesis or catalysis of reactions on surfaces and even in the creation of nanoscale devices [1, 2, 3, 4]. Between the most important topics related to these phenomena are the storage of gases in low-dimensional systems and the study of nanostructured fuel cells or batteries. In this context we used two different parametrizations for the reactive force field ReaxFF to study the potential barriers and reaction barriers of our system. First we made a study about the Reaction Barriers and Energy Barriers for bonds between graphene and the following atoms: sulfur, fluorine, hydrogen, nitrogen and oxygen. It is important to have this information in order to make it possible to understand how these atoms react with the graphene sheet. Subsequently, we calculate reaction barriers for mixed structures where fluorine is a fixed element bonded to graphene and other element is simultaneously bonded to graphene. This other element (N, O, H or S) is varied in its possible relative positions (ortho, meta and para in relation to fluorine in either: the same side and in the opposite side of the graphene membrane)
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The lubricant oil used in engines of internal combustion must be, periodically, changed. Its mainly function in the engines is to reduce the friction between the pieces, but its presence also promotes the cleanness and the refrigeration of the equipment. These attributions, at the end of some cycles of operation, make the oil to be dirty, that is, full of contaminating substances such as water, gasoline, diesel, additives, oxidized hydro-carbons and rests of metals, not being recommended, therefore, its discarding in the environment. Thus, all the used lubricant oil that leaves the automobiles engine has been thrust, waiting for a solution. The pollution generated by the discarding of a ton of used oil per day in the soil or in the rivers is equivalent to a domestic sewer of 40 thousand of people. The indiscriminate burning of the used lubricant oil generates significant emissions of metallic oxides, besides other toxic gases, like the dioxin and sulphur oxides. In this context, the mean objective of this essay was to effectuate the rerrefine of the used lubricant oil, aiming the increase of its life cycle and consequently contributing for the reduction of the environmental pollution. According to the used process, it was possible to get a rerrefine oil, of good quality, which physicistchemistries properties are in compliance with the norms of NBR and ASTM
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The aim of this experiment was evaluate the effect of the bioestimulant administered in grafted and non-grafted japanese cucumber (Cucumis sativus L.) plants, under greenhouse conditions, in gas exchanges during the development of the plant and in the increase of yield. The experiment was carried out in the experimental area of Agronomic Sciences University of UNESP, Campus of Botucatu, São Paulo State, Brazil. The experiment design was completely randomized, in a factorial arrangement of 2x5, grafted and non-grafted plants and 5 treatments with bioestimulant: control, indolbutyric acid 0,0005% + citocinine 0,0009% + gibberelic acid 0,005% 250 mL ha-1; indolbutyric acid 0,0005% + citocinine 0,0009% + gibberelic acid 0,005% 375 mL ha-1; indolbutyric acid 0,0005% + citocinine 0,0009% + gibberelic acid 0,005% 500 mL ha-1; Yuca extract (Yucca elephantipes) + manganese + iron + copper + sulfur 375 mL ha-1 applied 15 days after the transplant, in intervals of 7 days between the applications, via leaf. The effect of the treatments were evaluated through the observations of the following characteristics: production of fruits (number and mass), average mass of the fruit and measures of gas exchanges. It can be concluded that indolbutyric acid 0,0005% + citocinine 0,0009% + gibberelic acid 0,005% 250 mL ha-1 increased CO2 assimilation rate and the water efficiency, influencing in addition to increase the quantity of the fruits
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Mass spectrometry is an analytical technique widely used in several areas of academic research. It allows the knowledge of the information about the micro-world of atoms leading to significant advances in science today. The analysis of stable isotopes of carbon, hydrogen, oxygen, nitrogen and sulfur, also known as bio-elements, shows itself as a major area of interest in using the proposed method. The development of techniques and equipment coupled with mass spectrometry promises to deliver even greater progress in this field, in particular, for the biological sciences and related areas. The pyrolytic method in reduction of organic compounds at high temperatures provides simultaneous isotopic analysis of bio-elements H and O, by the gases released, H2 and CO after the pyrolitic process, significantly reducing analysis time and the amount of material to sample. This paper presents a review of mass spectrometry with its basic principles of operation, and pyrolytic method for reducing compounds at temperatures above 1400 ° C for isotopic analysis of bio-elements
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This paper proposes an analysis of two major polluting elements of the atmosphere of São Paulo city, carbon monoxide (CO) and sulfur dioxide (SO2). This study was performed through analysis of data on the quality of air, by means of published reports and records obtained by experiment using measuring rate monitor for CO2. Atmospheric data were collected and sorted. From this work it was possible to identify the concentration of carbon dioxide in the center of São Paulo on September 14, 2012 using the infrared gas analyzer (IRGA). From the ratios of carbon monoxide and sulfur dioxide spatially analyzed could identify major emitters by comparing records of pollutants and their origin. The analysis makes it possible to map the intensity of air pollution in urban areas, identifying the polluting elements, their issuers and thereby contributes to the current understanding of atmospheric features, bringing a geographical spatial analysis of air pollutants in São Paulo, contributing to awareness of vulnerabilities, enabling a useful tool for planning and maintenance of the urban environment related public policies
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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 Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV