964 resultados para Veículos flex
Resumo:
This study aimed to assess ambient air quality in a urban area of Natal, capital of Rio Grande do Norte (latitude 5º49'29 '' S and longitude 35º13'34'' W), aiming to determine the metals concentration in particulate matter (PM10 and PM2,5) of atmospheric air in the urban area o the Natal city. The sampling period for the study consisted of data acquisition from January to December 2012. Samples were collected on glass fiber filters by means of two large volumes samplers, one for PM2,5 (AGV PM 2,5) and another for PM10 (PM10 AGV). Monthly averages ranged from 8.92 to 19.80 g.m-3 , where the annual average was 16,21 g.m-3 for PM10 and PM2,5 monthly averages ranged from 2,84 to 7,89 g.m -3 , with an annual average of 5,61 g.m-3 . The results of PM2,5 and PM10 concentrations were related meteorological variables and for information on the effects of these variables on the concentration of PM, an exploratory analysis of the data using Principal Component Analysis (PCA) was performed. The results of the PCA showed that with increasing barometric pressure, the direction of the winds, the rainfall and relative humidity decreases the concentration of PM and the variable weekday little influence compared the meteorological variables. Filters containing particulate matter were selected in six days and subjected to microwave digestion. After digestion samples were analyzed by with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The concentrations for heavy metals Vanadium, Chromium, Manganese, Nickel, Copper, Arsenic and lead were determined. The highest concentrations of metals were for Pb and Cu, whose average PM10 values were, respectively, 5,34 and 2,34 ng.m-3 and PM2,5 4,68 and 2,95 ng.m-3 . Concentrations for metals V, Cr, Mn, Ni, and Cd were respectively 0,13, 0,39, 0,48, 0,45 and 0,03 ng.m-3 for PM10 fraction and PM2,5 fraction, 0,05, 0,10, 0,10, 0,34 and 0,01 ng.m-3. The concentration for As was null for the two fractions
Resumo:
The aim of this paper is to analyze the street demonstrations occurred last June and July 2013, which appear as samples of the hegemonic fights in course in Brazil, during the so-called Big Wave of the social groups in conflict nowadays in the country. Among other questions, this study tries to explain how the varied stages of these fighting groups influenced their late ones. For that, it takes into consideration the bibliography available not only on these groups, but also on the social and political contemporary Brazil. That is why it evaluates political documents, as well as opinion pieces, news and others disseminated by the press or by political groups. Speeches made by political leaderships, as, for example, that one the President Dilma Roussef made on 21 July 2013, deserves close analysis. This also applies to contributions made by secondary data, poll institutions and IBGE’s socio-economic data. Categories and concepts of Antonio Gramsci’s political sociology are used here as theoretic bases. In fact, it favors the hypothesis that, during the dispute for the intellectual and moral command of demonstrations on July 2013, a certain middle-class conservative ideology emerged on scene. This group conquered the agreement of hegemonic mass media acting now as a political party, here designated as media party. These media resorted to platforms preexistent to the demonstration movements, especially their rejection to political organizations and programs in order to ascend as the demonstrations’ leaders along a certain period in which corruption appeared as the central theme of these efforts, while the government tried to get control of the situation. In view of the several forces and issues at stake, the present study contributes to the discussion about the current reality in Brazil and its perspectives, without losing sight of the centrality of the June Movements as political and ideological milestones
Resumo:
One of the main problems related to the use of diesel as fuel is the presence of sulfur (S) which causes environmental pollution and corrosion of engines. In order to minimize the consequences of the release of this pollutant, Brazilian law established maximum sulfur content that diesel fuel may have. To meet these requirements, diesel with a maximum sulfur concentration equal to 10 mg/kg (S10) has been widely marketed in the country. However, the reduction of sulfur can lead to changes in the physicochemical properties of the fuel, which are essential for the performance of road vehicles. This work aims to identify the main changes in the physicochemical properties of diesel fuel and how they are related to reduction of sulfur content. Samples of diesel types S10, S500 and S1800 were tested according with the methods of the American Society for Testing and Materials (ASTM). The fuels were also characterized by thermogravimetric analysis (TG) and subjected to physical distillation (ASTM D86) and simulated distillation gas chromatography (ASTM D2887). The results showed that the reduction of sulfur turned the fuel lighter and fluid, allowing a greater applicability to low temperature environments and safer for transportation and storage. Through the simulated distillation data was observed that decreasing sulfur content resulted in higher initial boiling point temperatures and the decreasing of the boiling temperature of the medium and heavy fractions. Thermogravimetric analysis showed a loss event mass attributed to volatilization or distillation of light and medium hydrocarbons. Based on these data, the kinetic behavior of the samples was investigated and it was observed that the activation energies (Ea) did not show significant changes throughout conversion. Considering the average of these energies, the S1800 had the highest Ea during the conversion and the S10 the lowest values
Resumo:
The Brazilian Northeast has been a constant subject for journalists of one of the world's leading media companies - The New York Times - between 1933 and 1945. This time, the US government implemented a new foreign policy for Latin America - known as the Good Neighbor Policy. It preached, various points including more respect and attention to the countries south of U.S. borders. Because of her geostrategic importance, Brazil was one of the countries that received the most attention of the bureaucracy and American press. This study investigates the multiple Northeast representations formulated in The New York Times' pages when the Americans were spotlight is on the region. It delineates similarities and differences between the NYT, the press and the governments of the United States and Brazil from the ways of conceiving this particular part of Brazil. Through the analysis of texts, photographs and maps, it is dedicated to establish connections between spaces, press and politics of the 1930s and 1940s. These decades there were relevant changes in the political landscape of both countries that permeated the news, reports and articles of NYT. Circumstances such as the 1935 armed uprisings - known as Communist Conspiracy - the installation and operation of the New State, and especially the Brazilian and US participation in World War II and the bilateral negotiations on the installation of US bases in Brazil were cardinal for the various Northeast images that circulated in the publication. The region was repeatedly subject of correspondent of the New York newspaper in Brazil, Frank M. Garcia, but also present on matters of professionals responsible for various sections: review of books, publishing, tourism, foreign affairs, etc. Along the investigated period, the visions of the region made in the articles published in the newspaper that suffered major metamorphoses. Starting with Northeast of the drought, famine and death recurrent in Brazilian literature to the most dangerous point for hemispheric defense, passing through representations of the American West lawless nineteenth century and the Latin America marked by the dominance of exotic nature and stagnation, a space to be transformed by the US technical knowledge.