915 resultados para Contamination by Pb


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One of the key objectives in fuel-cell technology is to improve the performance of the anode catalyst for the alcohol oxidation and reduce Pt loading. Here, we show the use of six different electrocatalysts synthesized by the sol -gel method on carbon powder to promote the oxidation of methanol in acid media. The catalysts Pt-PbO(x) and Pt-(RuO(2)-PbO(x)) with 10% of catalyst load exhibited significantly enhanced catalytic activity toward the methanol oxidation reaction as compared to Pt-(RuO(2))/C and Pt/C electrodes. Cyclic voltammetry studies showed that the electrocatalysts Pt-PbO(x)/C and Pt-(RuO(2)-PbO(x))/C started the oxidation process at extremely low potentials and that they represent a good novelty to oxidize methanol. Furthermore, quasi-stationary polarization experiments and cronoamperometry studies showed the good performance of the Pt-PbO(x), Pt-(RuO(2)-PbO(x))/C and Pt-(RuO(2)-IrO(2))/C catalysts during the oxidation process. Thus, the addition of metallic Pt and PbO(x) onto high-area carbon powder, by the sol -gel route, constitutes an interesting way to prepare anodes with high catalytic activity for further applications in direct methanol fuel cell systems.

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O presente estudo tem como proposta, identificar o modo como o mineral monazita se encontra no concentrado final de ilmenita. Este concentrado é o produto resultante do beneficiamento do minério extraído de depósitos do tipo pláceres, conhecidos como depósitos de areias pretas. Estes depósitos são formados por dunas litorâneas pertencentes à jazida do Guaju, no município de Mataraca-PB. Todo o processo de lavra e beneficiamento deste minério ocorre na Mina do Guaju, a qual é operada pela empresa Millennium Inorganic Chemicals do Brasil S/A, pertencente a Lyondell Chemical Company. A ilmenita é um mineral composto por óxido de ferro e titânio, FeTiO3. Quase toda a ilmenita produzida na mina é transferida para o processo de fabricação de pigmento. A exigência para o uso na fabricação de pigmento é de que o concentrado final de ilmenita tenha um teor mínimo de 53% de TiO2 e um teor máximo de 0,1% de P2O5, entre outras substâncias. A monazita é o principal mineral fonte de óxido de tório, que é radioativo. No processo de fabricação de pigmento, a monazita é um contaminante indesejado. De acordo com a proposta de trabalho, foi feito um estudo de caracterização mineralógica de amostras do concentrado final de ilmenita fornecidas pela empresa. Inicialmente foram feitas análises em lupa, onde muitos grãos de leucoxeno foram identificados. O leucoxeno é uma alteração da ilmenita que permanece com as mesmas características magnéticas e eletrostáticas, tornando impossível, assim, a sua separação no processo de concentração. Também foi verificada a existência de grãos de monazita liberados em pequenas quantidades neste concentrado, indicando uma provável ineficiência no processo de separação. Numa segunda etapa foram realizadas análises dos grãos de ilmenita com o uso de um Microscópio Eletrônico de Varredura (MEV) acoplado a um Espectrômetro de Dispersão de Energia (EDS), para permitir a determinação de elementos químicos na amostra. Esta análise teve como objetivo verificar a existência de inclusões de monazita nos grãos de ilmenita. Porém, o que se observou foi a existência de algumas inclusões de quartzo e de alguns vazios deixados, provavelmente, por inclusões arrancadas durante o processo de preparação das amostras. Alguns destes vazios apresentaram formas semelhantes a de cristais de monazita, indicando a possibilidade da existência de inclusões deste mineral. Entretanto, a quantidade de grãos com possíveis inclusões de monazita é muito pequena, sendo insignificante como contaminante do concentrado final. Embora alguns vazios se assemelhem à forma da monazita, nenhum dos resultados do EDS identificou vestígios de sua presença. Ao final deste estudo ficou evidente que a principal fonte de contaminação do concentrado final de ilmenita corresponde à monazita, a qual se encontra liberada neste concentrado. Desta forma, há a necessidade de se melhorar o processo de separação dos minerais, de modo que a quantidade de monazita no concentrado final seja a menor possível, não prejudicando o rendimento da recuperação de ilmenita.

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The present study aims to understand the process of Participation of the Health Council- CMS in the formularization, implementation and control of the Municipal health plan of Pedras de Fogo, through four criteria of quality of participation considered by Demo (1993): representation, legitimacy, base participation, and self-responsibility. The criteria of representation is related to the quality of politics of the representative over the representings. Legitimacy is related to the politics` quality of the process of participation based on norms and rules that stipulate the participation, the base participation is a necessary political support so that the power authorization directed to the representings can be effective and the self-responsibility refers to the capacity of being responsible when it concerns to the public service or property. Through the descriptive and exploratory study a qualitative method was adopted to consider the conditions of the participation of the twelve council members of the City council of Health of Pedras de Fogo, through a formulated Instrument based on the criteria of DEMO (1993). It was concluded that the quality of the participation of the council members of the CMS of Pedras de Fogo understands essential aspects of the criteria of quality considered by Demo (1993) but it shows fragilities as unfamiliarity with the norms that legitimize the performance of the council; unfamiliarity of its condition of being an agent and the importance of the participation of the base for the reinforcement of its participation, as well as inertia related to the check and rendering of accounts on its performance. This way it makes sense that the participation of the council in the four criteria of quality of politics considered in this paper needs to improve

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The main objective of the study about the citizenship development in elderly attended by the Conviver Program of the City Hall of Campina Grande in Paraiba, Brazil was to evaluate how the actions of the Program contribute for the citizenship practice according to the users. The Citizenship analyzed is the existence of political, civil and social rights according to Marshall. For that it was utilized a descriptive research and a study of case based on technical procedure. The research was settled by the people who are benefited by the Conviver Program of the Snow Hair Group and the sample was formed by the active participants that it is in the Group for over ten years, corresponding to a total of ten elderly. For the data collection was utilized basic questionnaire in function of the low schooling of the interviewed, according to Marshall (2002) theory about the citizenship construction from each person. It was utilized the methodological procedure proposed by Bardin (2006), categorical analysis, in the qualitative data analysis, that was divided in four parts. In relation to Political Rights, noted that the program has stimulated your Watched on the exercise of voting and being voted. On the Civil Rights was observed that the Program has given incentive to actions which provide the users the justice rights in and in occupational activities as a job. In relation to Social Rights it was observed that the Conviver Program has contributed in order that its users can lead their lives according to the standards imposed by the society, which have being failed in the education area. As for the type of citizenship it was verified that the Program has given incentive to the served users, becoming more evidence on the speech basis

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With the disorganized decentralization occurred in Brazil after the 1988 Constitution, municipalities have risen to the level of federal entities. This phenomenon became known as "municipalism" also brought some negative effects such as low capacity financial, economic and political of these entities. In the face of this reality , the municipalities sought in models of collaborative features to address public policy issues ultrarregionais, one of these models are the Public Consortia. Characterized as the organization of all federal entities that aim to solve public policy implementation alone that they could not, or spend great resources for such. This reality of the municipalities have an aggravating factor when looking at the situation in Metropolitan Regions (MRs). This is because the RMs has a historical process of formation that does not encourage cooperation, since that were created top-down during the military regime. Furthermore, the metropolitan municipalities have significant power asymmetries, localist vision, rigidity earmarked revenues, different scenarios conurbation, difficulty standardization of concepts and others that contribute to the vision of low cooperation of these metropolitan areas. Thus, the problem of this work is in the presence of collaborative arrangements, such as the Public Consortia in metropolitan areas, which are seen as areas of low cooperation. To elucidate this research was used for analysis the cases of CONDIAM/PB and Consórcio Grande Recife/PE, because they are apparently antagonistic, but with some points of similarity. The cases has as foundation the Theory of Common Resources, which provides the possibility of collective action through the initiative of individuals. This theory has as its methodology for analyzing the picture IAD Framework, which proposes its analysis based on three axes: external variables, the arena of action and results. The nature of the method of this research was classified as exploratory and descriptive. For the stage of date analysis, was used the method of document analysis and content, Further than of separation of the cases according to theur especificities. At the end of the study, noted that the CONDIAM/PB was a strategy of municipal government of Joao Pessoa to attract funds from the Federal Government for the purpose of to build a landfill, and over the years the ideology of cooperation was left aside, the prevailing view localist municipalities. In the case of Consórcio Grande Recife/PE, members act with some degree of cooperation, especially the collaborative aspect of the region, however, still prevails with greater strength the power of the state of Pernambuco in the decisions and paths of the consortium. Thus, was conclude that the Public Consortia analyzed are an experience of collaborative arrangement, from the initiative of members, as the theory of common resources says, but has not actually signed as a practice of collective action to overcome the dilemmas faced by metropolitan areas

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Brazilian Housing policy has always promoted homeownership. In 1999, a new form of housing promotion was set up in the country with the PAR (Programa de Arrendamento Residencial, or residential rental programme). This is a sort of leasing, in which a right to buy is granted at the end of contract. Again, with this, the final objective is homeownership. This dissertation aims at further understanding the role of PAR in the wake of the country s housing policies of the post-BNH period, analysing the case of João Pessoa, capital city of Paraíba state. By focusing in the city, it has been possible to analyse also the impact of the programme in the dynamics of the city s urban development. Accordingly, the analysis of PAR seeks to understand the programme s operational aspects as well as its location, urban and architectural aspects. The operational aspects refer to how the programme is operated, considering the differences to the other housing programmes in the country. The urban and architectural aspects refer to location, typology and construction characteristics of housing estates produced under the scheme. This study gives a general view of the country s recent housing policy and programmes and the specific characteristics of PAR, observing also its impacts in the city development

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In the mid-1980s, the magazine Projeto published the Actual Brazilian Architecture catalogue presenting texts by Hugo Segawa and Ruth Verde Zein with a corpus of works and engaged architects of the 1960s and 1970s. To comprehend the Brazilian architectural production post-1964, in those years of the 1980s, became a significant mission to reactivate the Brazilian architectural debate weakened by the military dictatorship. In his doctoral thesis Spadoni (2003) deals with the different ways which characterizes the Brazilian architectural production of the 1970s. Marked by inventiveness, this production was in tune with the modern thinking and in the transition period between the 1970s and the 1980s it synchronized with the international debate about post-modern architecture. Considering Spadoni s doctoral thesis, this work deals with the modern experience observed in the one-family-houses built in the seventies in João Pessoa. Some modern experiences were not clear outside, to observe it, it was necessary to search for the type of experience into the spatial disposition and of the know-how constructive, because into the appearance some houses not make explicit the use of the modern language. Other observed experiences allude to the repertoire of the Brazilian period in the years 1940s-1960s, to the experience of the modern architecture in São Paulo of the 1960s, to the experiences in which the climate of the Northeastern region strongly influenced the architectural conception. We can also find in a reduced number of houses a particular experience: it refers to experiences that expose the constructive doing, which leave the material apparent and apply to the residential type the experience of the industrial pre-fabricated buildings

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Assuming that the form of a building shell and its content the spatial form are distinct dimensions of architecture - however indivisible and interdependent -, this study focus, in the light of the Social Logic of Space (HILLIER; HANSON, 1984), on the intrinsic properties through which domestic space was structured in a sample of single-family dwellings built in João Pessoa (PB) during the 1970s - when the vocabulary of modern architecture still prevailed in Brazil though sharing the urban scene with other architectural trends -, in order to investigate regularities or divergences underlying their conception. These dwellings were originally classified (ARAÚJO, 2010a) in five categories defined according to the form of their building shells and to their prevailing construction techniques: (1) Brazilian modern legacy (considered as truly Brazilian modern style); (2) Paulista architecture (that refers to the modern production of São Paulo, Brazil, from the 1950s through the 1970s); (3) experiences of rationalization and prefabrication ; (4) experiences of adaptation to the climate (referring to a design strongly influenced by the hot and humid climate of North-eastern Brazil); and (5) hybrid (to account for a kind of stylistic hybridism that includes formal attributes, which evoke our colonial past). This study aims to determine, through the analyses of nineteen cases that represent each category, whether this taxonomy corresponds to distinct modes of spatial configuration. This research therefore proposes an approach to the classification of domestic architecture based on topological properties. The dwellings spatial organization was represented, quantified and analyzed, their spatial properties explored in consonance with one another and with the literature. Results pointed out that there is no evidence of a reciprocal relationship between the formal look of the built shells and their respective spatial structures

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The State of Paraíba is one of the most dynamic states of Brazil, strategically located in the northeast, is notable for the excellent potential for integration of different transportation modes forming the states of Rio Grande do Norte, Pernambuco and Alagoas. The dynamic that occurs with port activity causes changes in the space where it is installed. And the elements of this space are always more than suffering direct or indirect influences as the flow in the port is expanded. Therefore, this region became subject to the accidental spillage of oil, because it presents a heavy traffic of ships of various sizes that can run aground or collide with oil causing accidental events. The study of geomorphological and sedimentological compositions of seafloor becomes important as more is known about the relationships between these parameters and associated fauna, and can identify their preferred habitats. The database background, acoustically collected along the proposed study area, is a wealth of information, which were duly examined, cataloged and made available. Such information can serve as an important tool, providing a geomorphological survey of the sedimentary area studied, and come to subsidize, in a flexible, future decision making. With the study area Port of Cabedelo, Paraíba - Brazil, this research aimed to evaluate the influence of the tidal surface and background in modeling the seabed, including the acquisition of information about the location of submerged rocky bodies and the depth of these bodies may turn out to be natural traps for the trapping of oil in case of leaks, and obtain the relationship between types of bed and the hydrodynamic conditions present in the region. In this context, for this study were collected bathymetric data (depth) and physical oceanographic (height of water column, water temperature, intensity and direction of currents, waves and turbidity), meteorological (rainfall, air temperature, humidity, winds and barometric pressure) of the access channel to the Port of Cabedelo / PB and its basin evolution (where the cruise ships dock), and includes tools of remote sensing (Landsat 7 ETM +, 2001), so that images and the results are integrated into Geographic Information Systems and used in the elaboration of measures aimed at environmental protection areas under the influence of this scale facilities, serving as a grant to prepare a contingency plan in case of oil spills in the region. The main findings highlight the techniques of using hydroacoustic data acquisition together bathymetric surveys of high and low frequency. From there, five were prepared in bathymetric pattern of Directorate of Hydrography and Navigation - DHN, with the depth in meters, on a scale of 1:2500 (Channel and Basin Evolution of Access to Port of Cabedelo), where there is a large extent possible beachrocks that hinder the movement of vessels in the port area, which can cause collisions, running aground and leaking oil. From the scatter diagram of the vectors of currents, it can be seen as the tidal stream and undergoes a channeling effect caused by the bidirectional effect of the tide (ebb and flood) in the basin of the Port of Cabedelo evolution in NW-direction SE and the highest speed of the currents occurs at low tide. The characterization weather for the period from 28/02 to 04/07/2010 values was within the expected average for the region of study. The multidisciplinary integration of products (digital maps and remote sensing images), proved to be efficient for the characterization of underwater geomorphological study area, reaching the aim to discriminate and enhance submerged structures, previously not visible in the images

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The garimpo gold mining activity has released about 2.500 tons of mercury in the Brazilian Amazonian environment in the 1980-1995 period. The northern region of Mato Grosso State, an important gold mining and trading area during the Arnazonian gold rush is now at a turning point regarding its economic future. Nowadays, the activities related to gold mining have only a low relevance on its economy. Thus, the local communities are looking for economic alternatives for the development of the region. Cooperative fish farming is one of such alternatives. However, some projects are directly implemented on areas degraded by the former garimpo activity and the mercury left behind still poses risks, especially by its potential accumulation in fish. The objective of the present study was to evaluate the levels of mercury contamination in two fish farming areas, Paranaita and Alta Floresta, with and without records of past gold-washing activity, respectively. Data such as mercury concentration in fish of different trophic level, size, and weight as well as the water physical and chemical parameters were measured and considered. These preliminary data have shown no significant difference between these two fish fanning areas, relatively to mercury levels in fish. (c) 2004 Elsevier B.V. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)