272 research outputs found

    Biogas from sugarcane vinasse: environmental, energy and regulatory issues for a political agenda in Braszil

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    XX Encontro Nacional de Economia Política: desenvolvimento Latino-Americano, Integração e Inserção Internacional - UNILA, Foz do Iguaçu, 26 a 29 de maio de 2015Brazil is the largest sugarcane producer in the world, an important input to ethanol production, which puts the country in a privileged position in biofuel world market. Besides the importance of sugar production in the sugarcane chain, this work focuses on ethanol production (ethanol industry), particularly its main waste, vinasse. Vinasse presents several environmental risks due to its bio composition and, if dumped in rivers or lakes, causes the phenomenon of eutrophication, which promotes a high growth of aquatic plant species and spread environmental problems. In this scenario, the anaerobic digestion of vinasse (the most abundant effl uent from a sugarcane biorefi nery) arises as an interesting alternative because, in addition to promoting the stabilization of organic matter, it also enables energy generation from biogas (biomethane). Anaerobic digestion generates biomethane and biofertilizer from vinasse. The objective of this article is to study the biogas potential generation from sugarcane vinasse in Brazil using anaerobic digestion technology also presenting the challenges and the governmental agenda required to develop biogas systems to sugarcane sector in Brazil. This work presented a huge biogas production potential from sugarcane vinasse. It can be used in multiple ways, and this work emphasized two important energy uses: to substitute natural gas and to generate electricity in a distributed generation concept. Besides the huge potential, there is an extensive agenda to solve and overcome the multiple barriers for biogas systems implementation in Brazil. According to international experience the strong governmental involvement is necessary and suffi cient condition to develop renewable energy sources. In that sense, biogas systems need to be inserted in Brazil’s policy agendaBanco Nacional de Desenvolvimento Econômico e Social (BNDES); Usina Hidrelétrica de Itaipu (ITAIPU); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Universidade Federal da Integração Latino-Americana (UNILA

    ASTM A923-Practice A application to identify intermetallic phases in a UNS S32750 superduplex welded joint

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    Os aços inoxidáveis duplex e superduplex apresentam propriedades superiores aos aços inoxidáveis convencionais. Essa superioridade é baseada na composição química e em uma microestrutura balanceada (aproximadamente 50% de ferrita). Durante a soldagem podem ocorrer alterações, tanto na composição química, como na fração volumétrica das fases presentes, que podem gerar a presença de fases intermetálicas, que alteram as propriedades originais desses aços. O objetivo deste trabalho é de aplicar a norma ASTM A923-Prática A para verificar a presença de fases intermetálicas na junta soldada de aço inoxidável superduplex UNS 32750. Foram soldados tubos de UNS 32750 com diâmetros externos de 18 e 44 mm e espessura de 1,5 mm. O processo utilizado foi o TIG orbital, com adição de 25Cr-10Ni-4Mo e diâmetro de 0,8 mm. O metal de base e as juntas soldadas foram caracterizados tanto em microscopia óptica como em microscopia eletrônica de varredura. Os resultados mostraram que não houve a precipitação de fases intermetálicas detectadas pela norma ASTM A923, porém na ZAC dos dois tubos estudados apareceram pequenas regiões com precipitação de nitretos de cromo, que também podem alterar as propriedades das juntas soldadas.Duplex and superduplex stainless steels present superior mechanical and corrosion properties when compared to usual stainless steels. This superiority is based on chemical composition when in a balanced microstructure (approximately 50% of ferrite). During welding, changes may occur in both, the chemical composition and volume fraction of phases in the material, which may generate the presence of intermetallic phases and, as a consequence, modify the mechanical and corrosion properties of this group of stainless steels. The objective of this work is to apply ASTM A923- Practice A to verify the presence of intermetallic phases in welded joints of UNS 32750 su-perduplex stainless steel. Tubes of UNS 32750, with external diameters of 18 and 44 mm and a thickness of 1.5 mm, were welded using orbital GTAW, with filler metal 25Cr-10Ni-4Mo and a diameter of 0.8 mm. The metal-based and welded joints were characterized by optical and scanning electron microscopy. The results showed that there was no precipitation of the intermetallic phase, such as sigma phase, detected by ASTM A923, but the HAZ of the two tubes studied presented small regions with chromium nitrides, which can also change the properties of welded joins.MCT/FINE

    Mulheres prefeitas e educação infantil: uma evidência empírica para os municípios brasileiros

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    Esse trabalho busca investigar o impacto da eleição de prefeitas mulheres sobre o número de creches de um município. É empregado o método de Regression Discontinuity Design usando dados do Tribunal Superior Eleitoral (TSE) para as eleições municipais de 2004 e 2008 e, buscando avaliar o log do número de creches nos municípios por crianças de 0 a 5 anos ao final de cada mandato, é utilizado o Censo Escolar, feito pelo INEP. Os resultados indicam que em municípios onde uma mulher ganha as eleições não tem um aumento significativo do número de creches por crianças no município, com um p-valor de 0,145 para uma margem de vitória das mulheres de 1%, e de 0,118 para uma margem de 0,75%, valores pouco maiores do que os admitidos para rejeitar a hipótese de igualdade entre prefeitos homens e mulheres quanto a essa variável

    Estimating credit and profit scoring of a Brazilian credit union with logistic regression and machine-learning techniques

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    Purpose – Although credit unions are nonprofit organizations, their objectives depend on the efficient management of their resources and credit risk aligned with the principles of the cooperative doctrine. This paper aims to propose the combined use of credit scoring and profit scoring to increase the effectiveness of the loan-granting process in credit unions. Design/methodology/approach – This sample is composed by the data of personal loans transactions of a Brazilian credit union. Findings – The analysis reveals that the use of statistical methods improves significantly the predictability of default when compared to the use of subjective techniques and the superiority of the random forests model in estimating credit scoring and profit scoring when compared to logit and ordinary least squares method (OLS) regression. The study also illustrates how both analyses can be used jointly for more effective decision-making. Originality/value – Replacing subjective analysis with objective credit analysis using deterministic models will benefit Brazilian credit unions. The credit decision will be based on the input variables and on clear criteria, turning the decision-making process impartial. The joint use of credit scoring and profit scoring allows granting credit for the clients with the highest potential to pay debt obligation and, at the same time, to certify that the transaction profitability meets the goals of the organization: to be sustainable and to provide loans and investment opportunities at attractive rates to members

    Porous titanium for biomedical applications : an experimental study on rabbits

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    Objective: The aim of this study was to carry out an in vivo assessment of bone ingrowth in two different types of porous titanium -the first being completely porous, and the second with a porous surface and dense nucleus, manufactured by powder metallurgy- and to evaluate their mechanical properties. Study design: Ten scaffolds from each group were submitted to metallographic analysis and compression tests. Next, two scaffolds of each type were inserted into 14 rabbits, which were sacrificed 8 weeks after surgery. The samples were submitted for histological examination. Results: Metallographic analysis revealed interconnected pores, and the average interconnected pore diameter was about 360 mm, with 36% total porosity. The totally porous titanium samples and the titanium samples with porous surface and dense nucleus showed an average compressive strength of 16.19 MPa and 69.27 MPa, respectively. After 8 weeks, the animals showed bone ingrowth, even into the most internal pores. Conclusions: The pore morphology was effective in permitting bone ingrowth in both groups. Titanium scaffolds with a porous surface and dense nucleus showed the best mechanical properties and most adequate interface

    EFEITOS DE UM PROGRAMA DE CAPACITAÇÃO DE SUSTENTABILIDADE PARA CATADORES PAULISTAS DE MATERIAIS RECICLÁVEIS E COMUNIDADES LOCAIS

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    Objetivo: o estudo buscou analisar os efeitos de um programa de capacitação para catadores de materiais recicláveis e suas comunidades, presentes na região metropolitana de São Paulo. Método/abordagem: o estudo segue a abordagem qualitativa, de pesquisa documental, com 22 entrevistas realizadas em campo, e aplicação dos modelos teóricos do Triple Bottom Line de Elkington (1998), de avaliação de programas de capacitação de Kirkpatrick e Kirkpatrick (2010) e da análise categórica de Flores (1994). Principais Resultados: os resultados indicaram efeitos sociais, econômicos e ambientais relevantes no contexto comunitário de atuação desses profissionais. Contribuições teóricas/práticas/sociais: o estudo colabora com os 17 ODS liderados pela ONU e amplia o papel social do catador para o desenvolvimento de comunidades sustentáveis. Originalidade/relevância: o estudo destaca sua originalidade ao investigar programas de capacitação de sustentabilidade para catadores de materiais recicláveis, bem como os efeitos desses conhecimentos para o progresso de comunidades em estado de vulnerabilidade social

    Proteome Analysis of Leptospira interrogans Virulent Strain

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    Leptospirosis is a worldwide zoonotic infection of human and veterinary concern. Caused by pathogenic spirochetes of the genus Leptospira, the disease presents greater incidence in tropical and subtropical regions. The identification of proteins that could be involved in the bacteria host interactions may facilitate the search for immune protective antigens. We report the proteomic analysis of Leptospira interrogans serovar Pomona virulent strain LPF cultured from kidney and liver of infected hamsters. Total protein extracts were separated by two-dimensional gel electrophoresis (2-DE), 895 spots were analyzed by MALDI-TOF mass spectrometry (MS), and 286 were identified as leptospiral proteins, corresponding to 108 distinct proteins. These proteins are allocated in all the bacterial cell compartments and are distributed in every functional category. Furthermore, the previously described, known outer membrane proteins, OmpL1, LipL21, LipL31, LipL32/Hap-1, LipL41, LipL45, LipL46, LruA/LipL71, and OmpA-like protein Loa22 were all recognized. Most importantly, this research work identified 27 novel leptospiral proteins annotated as hypothetical open reading frames (ORFs). We report for the first time an array of proteins of the Leptospira expressed by virulent, low-passage strain. We believe that our studies, together with the genome data will enlighten our understanding of the disease

    Bremsstrahlung in carbon thick targets by proton incidence

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    The subtraction of the continuum from an X-ray spectrum emitted by proton bombardment is usually carried out by means of a mathematical fitting. The purpose of the present work is to develop an analytical function to model the continuous spectrum generated in a PIXE experiment for different incident beam energies in carbon thick targets. With this purpose, PIXE spectra of a carbon bulk sample were measured in an ion accelerator. The proton beam energies were varied between 0.7 MeV and 2 MeV and the X-rays generated were collected by an energy dispersive spectrometer. The spectra analysis was performed taking into account the main effects underlying the production of the continuous spectrum. Nevertheless, for the cases considered here, it was found that the atomic bremsstrahlung is the most important and other contributions were neglected. The experimental spectra from carbon thick targets were corrected by self-absorption and detector efficiency. The results show that the spectral shape corresponding to thick targets corrected by these effects is similar to the functional behavior presented by thin targets.Fil: Pérez, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Bertol, Ana Paula Lamberti. Universidade Federal do Rio Grande do Sul; BrasilFil: Rodríguez, Tabatha P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Vasconcellos, Marcos Antônio Zen. Universidade Federal do Rio Grande do Sul; BrasilFil: Trincavelli, Jorge Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

    Para onde caminha o ensino das Artes Visuais?

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    En 2016 se cumplieron 20 años de la promulgación de la “Lei de Diretrizes e Bases da Educação” que reconoció el arte como área de conocimiento específica e instituyó como componente curricular obligatorio en todos los niveles de la educación básica. Pero, esta garantía se ha deshecho ante la creación de una “Base Nacional Comum Curricular” (BNCC) y de la “Reforma do Ensino Médio”. Tales situaciones colocaron el arte como subárea del currículo y de carácter optativo en la educación secundaria. ¿Cuáles son los posibles efectos de tales cambios para la formación docente y escolar en arte? ¿De qué modo estas resoluciones son una pérdida histórica para la enseñanza del arte? Acá presentamos algunas reflexiones sobre los cambios ocurridos en el escenario educativo para situar y ampliar las discusiones sobre la concepción de enseñanza y aprendizaje presente en esos documentos y que adentra los espacios escolares y la formación docente en arte.Em 2016 completaram-se 20 anos da promulgação da Lei de Diretrizes e Bases da Educação que reconheceu a arte como uma área de conhecimento específica e assegurou-a enquanto um componente curricular obrigatório em todos os níveis da educação básica. Contudo, algumas fissuras foram abertas diante de um movimento para a criação de uma Base Nacional Comum Curricular (BNCC) e de Reforma do Ensino Médio. Tais situações colocaram a arte enquanto subárea do currículo e de caráter optativo na etapa do ensino médio. Quais os possíveis efeitos de tais mudanças para a formação docente e escolar em arte? De que modo essas resoluções se constituem como uma perda histórica para o ensino da arte? Neste texto apresentamos um conjunto de reflexões sobre as mudanças ocorridas no cenário educacional para situar e ampliar as discussões sobre a concepção de ensino e aprendizagem presente nesses documentos e que adentra os espaços escolares e a formação docente em arte
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