152 resultados para Difusão iônica


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Oil exploration is one of the most important industrial activities of modern society. Despite its derivatives present numerous applications in industrial processes, there are many undesirable by-products during this process, one of them is water separated from oil, called water production, it is constituted by pollutants difficult to degrade. In addition, the high volume of generated water makes its treatment a major problem for oil industries. Among the major contaminants of such effluents are phenol and its derivatives, substances of difficult natural degradation, which due their toxicity must be removed by a treatment process before its final disposal. In order to facilitate the removal of phenol in wastedwater from oil industry, it was developed an extraction system by ionic flocculation with surfactant. The ionic flocculation relies on the reaction of carboxylate surfactant and calcium íons, yielding in an insoluble surfactant that under stirring, aggregates forming floc capable of attracting the organic matter by adsorption. In this work was used base soap as ionic surfactant in the flocculation process and evaluated phenol removal efficiency in relation to the following parameters: surfactant concentration, phenol, calcium and electrolytes, stirring speed, contact time, temperature and pH. The flocculation of the surfactant occurred in the effluent (initial phenol concentration = 100 ppm) reaching 65% of phenol removal to concentrations of 1300 ppm and calcium of 1000 ppm, respectively, at T = 35 °C, pH = 9.7, stirring rate = 100 rpm and contact time of 5 minutes. The permanence of the flocs in an aqueous medium promotes desorption of the phenol from the flake surface to the solution, reaching 90% of desorption at a time of 150 minutes, and the study of desorption kinetics showed that Lagergren model of pseudo-first order was adequate to describe the phenol desorption. These results shows that the process may configure a new alternative of treatment in regard the removal of phenol of aqueous effluent of oil industry.

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RAMOS, A. S. M. Estágio da difusão das tecnologias internet em organizações acadêmicas. In: ENCONTRO NACIONAL DE PRODUÇÂO, 18., 1998, Niteroi-RJ. Anais... Niteroi: ENP, 1998.

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Plasma process like ionic nitriding and cathodic cage plasma nitriding are utilized in order to become hard surface of steels. The ionic nitriding is already accepted in the industry while cathodic cage plasma nitriding process is in industrial implementation stage. Those process depend of plasma parameters like electronic and ionic temperature (Te, Ti), species density (ne, ni) and of distribution function of these species. In the present work, the plasma used to those two processes has been observed through Optical Emission Spectroscopy OES technique in order to identify presents species in the treatment ambient and relatively quantify them. So plasma of typical mixtures like N2 H2 has been monitored through in order to study evolution of those species during the process. Moreover, it has been realized a systematic study about leaks, also thought OES, that accomplish the evolution of contaminant species arising because there is flux of atmosphere to inside nitriding chamber and in what conditions the species are sufficiently reduced. Finally, to describe the physic mechanism that acts on both coating techniques ionic nitriding and cathodic cage plasma nitriding

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The ionic plasma nitriding is one of the most important plasma assisted treatment technique for surface modification, but it presents some inherent problems mainly in nitriding pieces with complex geometries. In the last four years has appeared a plasma nitriding technique, named ASPN (Active Screen Plasma Nitriding) in which the samples and the workload are surrounded by a metal screen on which the cathodic potential is applied. This new technique makes possible to obtain a perfect uniform nitrided layer apart from the shape of the samples. The present work is based on the development of a new nitriding plasma technique named CCPN (Cathodic Cage Plasma Nitriding) Patent PI 0603213-3 derived from ASPN, but utilizes the hollow cathode effect to increase the nitriding process efficiency. That technique has shown great improvement on the treatment of several types of steels under different process conditions, producing thicker and harder layers when compared with both, ASPN and ionic plasma nitriding, besides eliminating problems associated with the later technique. The best obtained results are due to the hollow cathode effect on the cage holes. Moreover, characteristic problems of ionic plasma nitriding are eliminated due to the fact that the luminescent discharge acts on the cage wall instead of on the samples surface, which remains under a floating potential. In this work the enhancement of the cathodic cage nitriding layers proprieties, under several conditions for some types of steels was investigated, besides the mechanism for nitrides deposition on glass substrate, concluding that the CCPN is both a diffusion and a deposition process at the same time

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The ionic nitriding process presents some limitations related with the control of the thickness of the layer and its uniformity. Those limitations that happen during the process, are produced due to edge effects, damage caused by arcing arc and hollow cathode, mainly in pieces with complex geometry and under pressures in excess of 1 mbar. A new technique, denominated ASPN (active screen shapes nitriding) it has been used as alternative, for offering many advantages with respect to dc plasma conventional. The developed system presents a configuration in that the samples treated are surrounded by a large metal screen at high voltage cathodic potencials, (varying between 0 and 1200V) and currents up to 1 A. The sample is placed in floting potential or polarized at relatively lower bias voltages by an auxiliary source. As the plasma is not formed directly in the sample surface but in the metal screen, the mentioned effects are eliminated. This mechanism allows investigate ion of the transfer of nitrogen to the substrate. Optical and electronic microscopy are used to exam morphology and structure at the layer. X-ray difration for phase identification and microhardness to evaluate the efficiency of this process with respect to dc conventional nitriding

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The pair contact process - PCP is a nonequilibrium stochastic model which, like the basic contact process - CP, exhibits a phase transition to an absorbing state. While the absorbing state CP corresponds to a unique configuration (empty lattice), the PCP process infinitely many. Numerical and theoretical studies, nevertheless, indicate that the PCP belongs to the same universality class as the CP (direct percolation class), but with anomalies in the critical spreading dynamics. An infinite number of absorbing configurations arise in the PCP because all process (creation and annihilation) require a nearest-neighbor pair of particles. The diffusive pair contact process - PCPD) was proposed by Grassberger in 1982. But the interest in the problem follows its rediscovery by the Langevin description. On the basis of numerical results and renormalization group arguments, Carlon, Henkel and Schollwöck (2001), suggested that certain critical exponents in the PCPD had values similar to those of the party-conserving - PC class. On the other hand, Hinrichsen (2001), reported simulation results inconsistent with the PC class, and proposed that the PCPD belongs to a new universality class. The controversy regarding the universality of the PCPD remains unresolved. In the PCPD, a nearest-neighbor pair of particles is necessary for the process of creation and annihilation, but the particles to diffuse individually. In this work we study the PCPD with diffusion of pair, in which isolated particles cannot move; a nearest-neighbor pair diffuses as a unit. Using quasistationary simulation, we determined with good precision the critical point and critical exponents for three values of the diffusive probability: D=0.5 and D=0.1. For D=0.5: PC=0.89007(3), β/v=0.252(9), z=1.573(1), =1.10(2), m=1.1758(24). For D=0.1: PC=0.9172(1), β/v=0.252(9), z=1.579(11), =1.11(4), m=1.173(4)

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MEDEIROS, Rildeci; MELO, Erica S. F.; NASCIMENTO, M. S. Hemeroteca digital temática: socialização da informação em cinema.In:SEMINÁRIO NACIONAL DE BIBLIOTECAS UNIVERSITÁRIAS,15.,2008,São Paulo. Anais eletrônicos... São Paulo:CRUESP,2008. Disponível em: http://www.sbu.unicamp.br/snbu2008/anais/site/pdfs/3018.pdf

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CARVALHO, Monica Marques; CARVALHO, Luciana Moreira; FREIRE, I.M. A digitalizaçao do acervo do nucleo tematico da seca da UFRN como possibilidade de socializaçao da informaçao. Interface, v.1, n.1, 2004.Disponivel em: http://www.ccsa.ufrn.br/interface/1-1/artigos.htm. Acesso em: 04 nov.2010.

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O objetivo deste estudo foi avaliar a atividade antibacteriana in vitro e cicatrizante do óleo de buriti (M. flexuosa) em feridas realizadas em ratos (Rattus norvegicus albinus). Para a avaliação antibacteriana in vitro, foram utilizados cinco patógenos bacterianos incluindo espécies gram-positivas e espécies gram-negativas mediante o uso do método de difusão em ágar. Para a avaliação da atividade cicatrizante, foram utilizados 40 ratos da linhagem Wistar, divididos em dois grupos: o grupo I, composto por 20 ratos com feridas cutâneas, tratados com aplicação tópica do creme base com 10% de óleo de buriti, e o grupo II, controle, com o mesmo número de animais que receberam a aplicação tópica do creme base. A aplicação do produto foi realizada em feridas padronizadas, circulares de 1cm de diâmetro na região dorsolombar. As avaliações clínica, morfométrica e histopatológica das feridas foram realizadas no 3°, 7°, 14° e 21° dias. Em relação à avaliação da atividade antibacteriana, os resultados mostraram que houve inibição do crescimento bacteriano em quatro dos cinco patógenos testados. Em relação à área da ferida, foi observada redução significativa da área no 14o dia e maior percentual de contração das feridas do grupo tratado em relação ao controle. No décimo quarto dia, as feridas tratadas com o óleo do buriti apresentavam aumento significativo na contagem de fibroblastos e fibras colágenas, além de completo processo de reepitelização, enquanto o grupo controle necessitava de mais tempo para resolução do processo cicatricial

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A nitretação é uma técnica de tratamento de superfície utilizada para endurecer superfícies de metais, principalmente de aços. O uso do plasma para auxiliar esta técnica vem crescendo nos últimos anos. Pelo fato desta técnica utilizar o plasma como fonte energética e este possuir uma vasta aplicação em outras técnicas para processamento de materiais, enobrece ainda mais a leitura do presente livro. Ele apresenta uma revisão da descarga elétrica em gases levando o leitor a refletir, multidisciplinarmente, sobre possibilidades de aplicação da mesma. Apresenta a técnica de nitretação iônica sob o aspecto histórico, científico, tecnológico, operacional e econômico e, finalmente, faz uma revisão das novas técnicas de endurecimento superficial assim como as técnicas convencionais de nitretação

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O contexto hodierno caracteriza-se como um panorama de uso contínuo de informação nas mais variadas esferas da sociedade. A informação é usada em diversos contextos sob vários formatos e isso se torna possível com a evolução tecnológica realizada em ritmo acelerado, sobretudo nos últimos dois séculos. Essa evolução trouxe consigo a possibilidade ampliada de acesso à informação, mas por outro lado, impôs desafios circunstanciais no seu tratamento e difusão. Nos diversos tipos de unidades de informação, faz-se necessária a adoção de estratégias para a melhoria do gerenciamento e desenvolvimento das coleções, sobretudo as coleções digitais. De tal modo, o trabalho visa a traçar um panorama ligado às questões relacionadas à comunicação cientifica com a bibliotecas universitárias, com vistas a ampliar o debate sobre o desenvolvimento digital de coleções de periódicos em bibliotecas universitárias, bem como aspectos relacionados à adoção de critérios de seleção e avaliação destes itens de informação. Aborda os casos específicos, como o do Portal Capes e o SciELO como coleções digitais de periódicos sujeitos a estratégias de desenvolvimento das coleções. Aponta opções para a melhoria da gestão da coleção digital em bibliotecas universitárias. A metodologia empregada foi a de pesquisa bibliográfica em uso de fontes eletrônicas e convencionais, bem como análise de critérios utilizados na Avaliação e Coleções para Bibliotecas Universitárias e o Indicadores Qualis pela Condenação de Aperfeiçoamento de Pessoa de Ensino Superior (CAPES).

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The globalization of markets has confirmed for the processes of change in organizations both in structure and in management. This dynamic was also observed in credit unions because they are financial institutions and are under the rules of the Brazil´s Financial System. Given the context of organizational changes in the financial capital has played the traditional management reform is urgent. In organizations credit unions, given its dual purpose, because in the same organizational environment and capitalism coexist cooperative whose logics are antagonistic, but can live through the balance between instrumental rationality and substantive rationality in credit unions. Based on this concept a new form of management should be thought to be able to accommodate the demand of cooperative, community, government and the market. Hybridization has been observed in management practices` COOPERUFPA into dimensions financial, social and solidarity participation with a trend in paradigmatic form of hybrid management, in that it directly or indirectly affect the management decisions in the credit union. The hybrid management is a trend that has been setting the basis for societal transformation, so that credit unions promote actions of welfare oriented cooperative members and the community around the same time that attend the dynamics of market globalization. These actions, in the context of hybrid management should be implemented by COOPERUFPA from the sociability of the remains and the wide diffusion of solidarity culture between cooperative partnership as a way to recover their participation in trade relations, financial and the social collective developement. For the members of COOPERUFPA financial interest is evidenced in greater relevance for the social interest given its dominant relationship as "mere customer" of the credit union, however, the proactive participation of the life of the cooperative credit union is one of its expectative among of participation of to share power in decisions by general meetings. This passivity`s cooperator of the COOPERUFPA in defending the ideals overshadowed the spread of cooperative principles and values of cooperation among them. Thus his conception for COOPERUFPA in the financial dimension, social and solidarity democracy, performed transversely. The COOPERUFPA for not developing an education policy for the cooperation among its members, contributed to a process of collective alienation of cooperative ideals, since the cooperative do not understand the reality that surrounds them as members of an organization whose mission is to social and financial sustainability of its members

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Based on the definitions of Public Communication, Political Marketing, Public Interest Information and Communication as a Tool of Governance, the study notes the use of the news section of the websites of the City Christmas and Mossoro, Rio Grande do Norte, in regard to strengthening citizenship and encouraging participatory management, from the characterization of materials like pieces of Political Marketing and Public Communication. Data collection in qualitative research was conducted from August to September 2011 and content analysis showed that the appropriation of public property for personal use is a reality, despite legal requirements to the detriment of strategic communication and governance for results from the dissemination of information of public interest and the establishment of a communication channel between State Government and Society. Elements of this study suggest the need for further research to deepen the discussion

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The goal of this paper was to search the state of the art from the Digital Libraries in Architecture and Urbanism in the Higher Education Institutions (IES) through conceptualizations and showing the importance of Digital Libraries in the disclosure and easing of information transferring. Questions about digital information architecture, usability, digital preservation and accessibility were approached. The research was made in the websites of Brazilian Universities, firstly to identify the institutions which offered the Architecture and Urbanism course, focusing on postgraduate education. After identifying the offering, the research was done by analyzing the contents, storage and dissemination and access to information, these libraries. It was found that the digital libraries are increasingly and taking part of organizations and educational institutions focusing on the knowledge dissemination releasing digitally information that may be needed for institution or the individual. A monitoring was done over of the physical and computational restructuring of the Board of Studies and Research in Architecture and Urbanism (Câmara de Estudos e Pesquisa em Arquitetura e Urbanismo, CEPAU), from the Architecture and Urbanism Course of the Federal University of Rio Grande do Norte (UFRN), showing the need of installing a Digital Library to integrate the databases of PPGAU s research groups, which today remain independent, with no interface among themselves. The research chosen area was Architecture and Urbanism, because there is a gap and little documentation about digital libraries in this area

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This work presents a reflection on possibilities and boundaries of consolidation and expansion of human settlements characterized as traditional communities that are located within protected areas, using as study reference the State Sustainable Development Reserve Ponta do Tubarão, at Rio Grande do Norte state. The main topics highlight the conflict between the right to housing and the prevalence of fundamental rights of traditional populations, opposed to the diffuse right to environment, according to the regulatory framework of the Brazilian Urban and Environmental Policies. At the same time that these settlements, historically built, are substantiated by the principles of recognition of rights to traditional populations, they are in a condition of complexity to the resolution of conflicts in its urban dimension and lead to an impairment of natural sites. This work questions how the instruments of land use and occupation are defined and relate to environmental planning, especially considering that the settlements are located in Permanent Preservation Areas (APP). It aims to further the discussion of the urban dimension in settlements, characterizing its formation and growth process, to identify the gaps and convergences between the Urban and Environmental Policy, under the foundations of a socio-environmental approach. The results spotlights the conflicts between occupation and natural areas, inferring that the definition of Urban Policies instruments and its integration with Environmental Policies instruments account for essential and priority actions to the achievement to the rights to a sustainable city, as determined in the Cities Statute and environmental protection goals, defined for the Conservation Units