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Sample records for industriais empregando-se tracadores

  1. Evaluation of urban and industrial wastewater treatment plants using radioactive tracers; Otimizacao de unidades de tratamento de aguas residuais urbanas e industriais empregando-se tracadores radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Luis Eduardo Barreira

    2001-07-01

    A methodology for studies and evaluation of sewage treatment plants with radioactive tracers is presented.. Radioisotopes as {sup 82} Br ( for the liquid phase), {sup 110m} Ag and {sup 140} La, (for the solid phase) was used to evaluate sewage flow rates, mixing pattern in equalization tank and test effluent treatment units. The tracer was injected in the unit (instantaneously or in a constant rate with a pump) and NaI-scintillation detectors measured the output signal. The Fortran program TRACADORES was developed to analyze the response function of the units in form of residence times distribution curves (RTD), which represents the probability of an element of the material to interact with the unit, and calculate the mean residence time {gamma}, the central moment of this distribution function. This fundamental parameter characterizes the tank and serves as a quantitative evaluation for its performance. With the radiotracer techniques was possible to identify dead zone, channeling, internal circulation of the solid phase inside the tanks. The technique represents a guideline for redesign a imperfect unit and eliminate the problem. (author)

  2. de projetos industriais

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    Jabra Haber

    2006-01-01

    Full Text Available Neste trabalho, apresenta-se uma ferramenta que pode ser utilizada na análise da viabilidade de projetos industriais. Trata-se de um modelo que combina, matematicamente, dados quantitativos, qualitativos e estratégicos não comparáveis entre si – um conjunto de atributos que, por meio de notas obtidas, levará a um placar que auxiliará na tomada de decisão sobre o investimento.

  3. DIRETRIZES PARA A GESTÃO DE PROJETOS INDUSTRIAIS

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    Tássia Farssura Lima da Silva

    2014-12-01

    Full Text Available A crescente demanda por rapidez na construção, menores custos e maior controle da qualidade geram uma complexidade na gestão do processo de projeto. Estudos voltados aos projetos industriais ou obras por encomenda ainda são em minoria, ou seja, há poucos trabalhos desenvolvidos e publicados sobre este tema. Além disso, especificamente no segmento escolhido, a complexidade e a diversidade dos projetos, associadas às inúmeras exigências de mercado, demandam melhorias das práticas de gestão de projetos.O trabalho tem como objetivo identificar, por meio de estudos de caso, as ações de gestão utilizadas em projetos industriais (obras por encomenda, caracterizar o processo de projeto, assim como analisar a atuação dos gestores de projeto e suas dificuldades.A pesquisa em questão compõe-se de três fases que se sobrepõem: a primeira fase contempla uma revisão bibliográfica de conceitos relevantes para o estudo; a segunda corresponde à apresentação e discussão de estudos de caso, visando caracterizar a gestão do processo de projeto no segmento dos projetos industriais; a terceira e última fase corresponde à reflexão sobre os principais pontos críticos identificados nos estudos de caso. Como resultado, será possível propor diretrizes aos agentes envolvidos, visando à melhoria contínua e a potencializar o sucesso da gestão de projetos industriais.

  4. Mapeamento de Empresas Industriais no Estado de Mato Grosso

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    Rafael Vitaliano Ferreira Coelho

    2014-12-01

    Full Text Available O presente estudo objetivou mapear potenciais Arranjos Produtivos Locais (APLs Industriais no estado de Mato Grosso, por meio de dados quantitativos de Unidades Empresariais e Industriais, obtidos pelo Banco de Dados da JUCEMAT – Junta Comercial do Estado de Mato Grosso, no período de janeiro de 2010 a dezembro de 2013. Foi adotado como metodologia de identificação de APLs potenciais o Coeficiente Locacional (QL. A partir dos dados, foram feitas análises buscando evidenciar as aglomerações industriais dentre o universo total de empresas distribuídas entre os 141 municípios mato-grossenses. Os resultados indicaram cerca de 70 municípios potenciais especialistas em indústria extrativa no período entre 2010 e 2013, sendo que 14 foram classificadas no 1º quartil dos municípios com QL>1 em todo o período. Além disso, cerca de 68 municípios apresentaram QL>1 para indústria de transformação e 12 locais encontram-se no 1º quartil deste grupo no período 2010-2013. De forma geral, a mesorregião Norte Mato-grossense apresentou maior aglomeração de municípios especializados em indústria, indicando potencial de adensamento produtivo. Em que pese a reduzida participação da indústria extrativa no PIB regional, o número de empreendimentos extrativos cresceu a uma taxa geométrica de 3,88% ao ano entre 2010 e 2013, frente a uma expansão de 4,64% de todo o tecido empresarial e de 0,22% das indústrias transformadoras no mesmo período. Concluem-se da necessidade de criação de mecanismos de atratividade e adensamento dos APLs potenciais industriais, aproveitando o nível de especialização existente para que haja maior agregação de valor dos produtos agropecuários de Mato Grosso.

  5. ENERGIA SOLAR TÉRMICA: INOVAÇÃO EM AQUECIMENTO DE ÁGUA PARA PROCESSOS INDUSTRIAIS / SOLAR THERMAL ENERGY: WATER HEATING INNOVATION FOR INDUSTRIAL PROCESSES

    OpenAIRE

    E. F. Carreira Junior; J. B. Sacomano; M. Mollo Neto

    2014-01-01

    O aumento do consumo mundial de energia tem gerado a busca de fontes alternativas, inclusive a solar, de fácil utilização, não exigindo equipamentos muito sofisticados nem complexos. Muitos processos industriais utilizam água em temperaturas até 100°C. O uso de energia solar na indústria ainda é baixo se comparado ao consumo energético total. O objetivo deste artigo é investigar possibilidades de usos de aquecimento solar de água em processos industriais, para o que foi utilizada pesquisa bib...

  6. Reparação de Danos Causados por Contaminação de Organoclorados: O Caso Rhodia Cubatão-SP

    OpenAIRE

    Souza, José Fernando Vidal de

    2016-01-01

    O artigo trata da produção de organoclorados pela fábrica da Rhodia S.A., localizada em Cubatão-SP, responsável pela contaminação do solo, das águas superficiais e subterrâneas da região. Desta forma, empregando os métodos dedutivo e sistêmico para detalhamentos dos fatos e fenômenos, após um histórico da mencionada unidade fabril, discute-se o conceito de organoclorados, analisa-se a reparação do dano causado por resíduos industriais, com as teorias de maior importância para a delimitação do...

  7. Von Thünen e o abastecimento madeireiro de centros urbanos pré-industriais

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    Diogo de Carvalho Cabral

    2011-12-01

    Full Text Available A madeira era um recurso natural indispensável ao metabolismo dos centros urbanos pré-industriais, tanto como material construtivo quanto como fonte energética. Em razão da baixa relação valor/volume dos produtos madeireiros, a espacialidade desse setor econômico era largamente determinada pelo custo de transporte. Deste modo, um arcabouço teórico que pode ser importante para a compreensão do fenômeno do abastecimento madeireiro das cidades pré-industriais é a clássica teoria de von Thünen sobre o efeito da distância do mercado sobre a estrutura da produção agrária. O artigo tem como objetivo discutir as potencialidades e limitações desta abordagem. Inicialmente, é apresentada a teoria do "Estado Isolado" e revisam-se os estudos históricos que a utilizaram, tanto como alicerce interpretativo quanto como teoria empírica. Em seguida, é formulado um modelo teórico-conceitual em que a atividade madeireira responde às variações da intensidade agrícola, procurando mostrar a utilidade desse esquema na interpretação do caso da cidade do Rio de Janeiro, no final do período colonial.

  8. Análise do Uso de Instrumentos de Controladoria nos Empreendimentos Comerciais e Industriais, de São João Del-Rei – Minas Gerais

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    Eduardo Aguiar Silva

    2016-10-01

    Full Text Available Este trabalho teve por objetivo analisar como os empreendimentos comerciais e industriais, fundados a partir de janeiro de 2010 vêm empregando instrumentos de controladoria no processo de tomada de decisão, desde a fase pré-operacional, de modo a verificar como tais instrumentos estão relacionados com o aumento das expectativas de vida e com a saúde financeira dessas empresas. Utilizou-se da pesquisa bibliográfica, documental e de campo. Os principais resultados dos trabalhos foram: a a maioria das empresas na fase operacional não esteve preocupada com o uso de instrumentos de controladoria para o planejamento e controle de suas atividades; b na fase operacional, há um maior uso de instrumentos ligados à função gerencial, que surgiu da necessidade de gerar informações para a tomada de decisões, no entanto, está limitado ao controle de estoques, de pagamentos e recebimento e de fluxo de caixa; c há dificuldade em usar os instrumentos das demais funções - contábil, custos, tributária e proteção ao patrimônio – pela dificuldade em extrair as informações dos demonstrativos e dos documentos gerados pelos escritórios de contabilidade; d as funções contábeis e tributárias têm sido desempenhadas pelos escritórios de contabilidade, com a finalidade apenas de cumprir as exigências da legislação. Conclui-se que, apesar de reconhecerem a importância da controladoria, suas ferramentas têm sido negligenciadas por empresários que, por falta de conhecimento, continuam tomando decisões com base em intuições. Estruturar um bom sistema de informação com base nas ferramentas da Controladoria é importante para garantir a sustentabilidade econômica e financeira desses empreendimentos ao longo do tempo.

  9. Desenvolvimento de princípios fundamentais para a gestão ambiental de empresas industriais

    OpenAIRE

    Delazaro Filho, José

    2010-01-01

    A partir dos conceitos básicos da área de segurança e higiene do trabalho, objetiva criar e organizar um conjunto de princípios próprios para gerenciar o meio ambiente da área industrial. Para tanto, levanta a problemática e os conflitos, e através de casos, apresenta o tratamento de questões ambientais relativas à as operações industriais. Pelas tomadas de decisão verificadas nos casos, comprova a validade de utilização de um conjunto de princípios iniciais, adaptados da área de higiene e se...

  10. O planejamento da manufatura: práticas industriais e métodos de otimização Manufacturing planning: industrial practices and optimization methods

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    M.F. Carvalho

    1998-04-01

    Full Text Available Este trabalho apresenta uma revisão das metodologias mais utilizadas como ferramentas de apoio ao planejamento da produção de sistemas de manufatura. Dentre elas destacam-se as práticas industriais conhecidas como técnicas avaliativas de soluções e os métodos de otimização conhecidos como técnicas gerativas de solução. Procura-se discutir como estas técnicas trabalham e analisar as vantagens e desvantagens de cada uma delas. Na conclusão a otimização é apresentada como uma ferramenta complementar para superar certas deficiências encontradas durante a aplicação das práticas industriais, tornando-se assim essencial ao planejamento da produção.This paper presents a review of the most common methodologies used as tools for supporting the production planning process of manufacturing systems. The industrial practices, known as evaluative techniques, and the optimization methods, known as generative techniques are highlighted. The way these techniques work is discussed, and their advantages and drawbacks are analyzed. It is concluded that optimization is a complementary tool for overcoming certain deficiencies found during the application of industrial practices and is essential for production planning.

  11. Comparing the prevalence rates of social phobia in a community according to ICD-10 and DSM-III-R Comparando estimativas de prevalência da fobia social na comunidade empregando-se a CID-10 e a DSM-III-R

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    Fábio Lopes Rocha

    2005-09-01

    Full Text Available OBJECTIVE: This population-based study aimed to compare the prevalence rates of social phobia using DSM-III-R and CID-10, based on the Composite International Diagnostic Interview (CIDI, in a Brazilian community. METHODS: This survey was carried out in a representative sample of 1,041 residents from Bambuí, Minas Gerais, Brazil (attrition rate = 14.7%. The Brazilian version of the CIDI was used. One-month, one-year and lifetime social phobia prevalence rates were estimated, employing the DSM-III-R and ICD-10 classifications, using the CIDI computer program. RESULTS: One-month, one-year, and life prevalence rates of social phobia, based on the DSM-III-R (7.9, 9.0 and 11.7% respectively were higher than those based on the ICD-10 (4.7, 5.2 and 6.7% respectively; p OBJETIVO: Este estudo populacional visa comparar estimativas de prevalência de fobia social empregando-se a CID-10 e a DSM-III-R em uma comunidade brasileira. MÉTODOS: O levantamento foi realizado em uma amostra representativa de 1.041 residentes de Bambuí, Minas Gerais, Brasil (perda = 14,7%. Foi utilizada a versão brasileira da Composite International Diagnostic Interview (CIDI. As prevalências de 1 mês, 1 ano e vida foram estimadas empregando-se as classificações CID-10 e DSM-III-R, utilizando-se o programa de computador da CIDI. RESULTADOS: As prevalências de 1 mês, 1 ano e vida da fobia social, baseadas na DSM-III-R (7,9, 9,0 e 11,7% respectivamente foram mais elevadas que aquelas baseadas na CID-10 (4,7, 5,2 e 6,7%, respectivamente; p < 0,01 para todos. CONCLUSÃO: Nossos resultados reforçam a hipótese de que as taxas de prevalência de fobia social são mais elevadas quando baseadas na DSM-III-R em comparação com a CID-10.

  12. CARACTERÍSTICAS MICROBIOLÓGICAS E FÍSICO-QUÍMICAS DE SORVETES ARTESANAIS E INDUSTRIAIS COMERCIALIZADOS NA REGIÃO DE ARAPONGAS-PR

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    Laíse Pazianotti

    2010-12-01

    Full Text Available O sorvete é um alimento consumido em todas as faixas etárias, devido suas características sensoriais e alto valor nutricional. Este trabalho teve como objetivo avaliar a qualidade dos sorvetes industriais e artesanais comercializados na região de Arapongas-PR. Três marcas de sorvetes artesanais e quatro de sorvetes industriais foram avaliadas, sendo 3 lotes diferentes de cada marca, quanto as suas características microbiológicas (pesquisa de Salmonella e contagens de estafilococos coagulase-positivo, coliformes totais e coliformes termotolerantes , e fí sico-químicas (pH, acidez titulável e composição centesimal. As amostras atenderam os padrões físico-químicos exigidos pela legislação brasileira. Não foi observada a presença de Salmonella e estafilococos coagulase-positivo. Porém, as contagens de coliformes totais e de termotolerantes estavam acima do limite estabelecido em todas as amostras, apresentando-se, portanto, impróprias para o consumo.

  13. A cultura organizacional e o sucesso da implantação e manutenção da manufatura enxuta: estudo de múltiplos casos em empresas industriais

    OpenAIRE

    Paoli, Filipe Marafon de

    2015-01-01

    O surgimento do relatório do MIT (Massachussets Institute of Technology), o qual fora evidenciado por meio do livro "A máquina que mudou o mundo", contribuiu para que empresas de diversos ramos da indústria tomassem conhecimento sobre a manufatura enxuta e o que ela representa. No Brasil, em particular, observou-se nos últimos anos um aumento expressivo da implementação da manufatura enxuta em diversos setores industriais, pois as empresas aderiram a ela para se tornarem mais competitivas em ...

  14. Modelagem e simulação de uma residência empregando o Sistema Estrutural Light Steel Frame (LSF)

    OpenAIRE

    Chong, Cesar Rodrigo Faraone Wing

    2017-01-01

    Metadados do Trabalho de Conclusão de Curso: Modelagem e simulação de uma residência empregando o Sistema Estrutural Light Steel Frame (LSF), pela/o discente: Cesar Rodrigo Faraone Wing Chong do Centro de Tecnologia e Infraestrutura, curso de Engenharia Civil e Infraestrutura da Universidade Federal da Integração Latino-Americana (UNILA), no Repositório Institucional da UNILA (RI-UNILA) Modelagem e simulação de uma residência empregando o Sistema Estrutural Light Steel Frame (L...

  15. Sistemas de custos para pequenas empresas industriais

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    Moraes, João Vicente de

    2002-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção. Este trabalho define um sistema de custos para pequenas empresas industriais, o qual permite identificar o custo, resultado e margem de contribuição por produto e ponto de equilíbrio , considerando o período de apuração do resultado. O sistema proposto é aplicado em um caso prático, em uma empresa estabelecida na cidade de Cascavel-PR., que produz rodas ...

  16. COMPORTAMENTO DOS SÓLIDOS TOTAIS NO PROCESSO DE DIGESTÃO ANAERÓBIA DE RESÍDUOS SÓLIDOS URBANOS E INDUSTRIAIS

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    Valderi Duarte Leite

    1999-08-01

    Full Text Available RESUMO O processo de digestão anaeróbia pode ser aplicado para bioestabilizar uma grande variedade de substratos. Neste trabalho, empregou-se o processo de digestão anaeróbia à fração orgânica putrescível dos resíduos sólidos urbanos, tomando-se como parâmetros avaliativos os sólidos totais e os sólidos totais voláteis. O trabalho foi realizado em quatro reatores anaeróbios de batelada, com capacidade unitária de 50 L e a análise dos seus dados mostra que é possível se empregar o processo de digestão anaeróbia a esse tipo de substrato que, além de bioestabilizar a matéria orgânica putrescível, produz gás metano, que pode ser utilizado como fonte alternativa de energia para fins domésticos e industriais.

  17. ANÁLISE DAS PRÁTICAS DE REUSO DE ÁGUA RESIDUAL: ESTUDO DE CASOS EM LAVANDERIAS INDUSTRIAIS

    OpenAIRE

    Souza, Mariane Cásseres; Vargas, Andrea; Saueressig, Gislaine Gabriele; Luchese, Juliane; Bauer, Jéssica Mariella; Viegas, Cláudia Viviane

    2016-01-01

    Água é um insumo de uso abundante em processos de lavanderias industriais. O reuso da água em Estação de Tratamento de Efluente reduz custos e traz benefícios ambientais, ou seja, é um fator de ecoeficiência. Esta pesquisa analisa duas empresas do ramo de lavanderias industriais, de médio porte, localizadas na região Sul do Brasil, e identifica melhorias quanto ao reúso da água. O método de pesquisa foi o estudo de caso múltiplo. Os resultados obtidos identificaram a diminuição da carga polui...

  18. O papel das organizações industriais virtuais em mercados emergentes: o caso do Mercosul

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    Andrea V Steil

    1998-12-01

    Full Text Available Este artigo analisa o impacto da globalização nas organizações industriais do Mercosul. O artigo enfatiza que o Mercosul tem o poder de estimular o desenvolvimento de organizações industriais virtuais entre as organizações do Mercosul. Uma vez que a dependência de links eletrônicos para completar o processo de produção é a condição estrutural mais importante das organizações industriais virtuais, este artigo também apresenta a atual infra-estrutura tecnológica da industria média da região. Especificamente, o artigo apresenta o estágio de integração de aplicações da tecnologia da informação nas indústrias do Mercosul e seus níveis de interoperabilidade.This paper analyzes how globalization is impacting Mercosul's industrial enterprises. It stresses that Mercosul has the power to foster the development of industrial virtual enterprises between organizations of the participant countries. Since the most important structural condition of industrial virtual enterprises is their dependency on electronic links to complete the production process, the paper also presents the current technological infrastructure of the average manufacturing organization of the region. Specifically, the paper presents the stage of integration of IT applications in Mercosul's industrial organizations and its levels of interoperability.

  19. A tecnologia de remoção de fósforo: gerenciamento do elemento em resíduos industriais

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    Mariana Manzoni Maroneze

    2014-07-01

    Full Text Available As elevadas concentrações de fósforo em águas residuárias industriais é uma das principais causas da eutrofização de corpos hídricos receptores, havendo em virtude disto, uma crescente preocupação com o gerenciamento das cargas de fósforo dos efluentes industriais. Além dos aspectos de contenção ambiental, é estrategicamente desejável que os processos de tratamento permitam a recuperação e o reúso deste elemento que é considerado de elevada demanda biológica. Neste sentido, esta revisão objetiva descrever e analisar criticamente o estado atual das tecnologias de gerenciamento de fósforo em águas residuais industriais, com ênfase no reúso do elemento. As tecnologias consideradas incluem abordagens químicas (precipitação química e adsorção, biológicas (sistemas bacterianos, uso macroalgas e microalgas além de técnicas de fertirrigação.

  20. Análise dos stakeholders das empresas industriais do estado de São Paulo

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    Flavio Hourneaux Junior

    2014-03-01

    Full Text Available Neste estudo, pretende-se analisar as relações entre as empresas industriais do estado de São Paulo e seus stakeholders, tendo como base conceitual a Teoria dos Stakeholders. A pesquisa, descritiva e quantitativa, parte de três atributos - poder, legitimidade e urgência - que definem a relação ou influência entre cada stakeholder e a organização. O levantamento de dados foi conduzido por meio de uma pesquisa do tipo survey eletrônica, com o uso de um questionário enviado a associados do Centro das Indústrias do Estado de São Paulo. A amostragem adotada foi intencional e não probabilística, obtendo-se uma amostra com 149 respostas válidas. Apesar das restrições metodológicas, os resultados indicam que os stakeholders são vistos pelos respondentes de formas diversas, o que tornaria viável a diferenciação de tratamento e de priorização estratégica dos stakeholders por parte das organizações, com predomínio dos clientes e consumidores sobre os demais. Por meio de uma análise fatorial, agruparam-se as 11 classes de stakeholders analisadas em 3 categorias - relacionamento direto com o negócio, relacionamento indireto com o negócio e propriedade do negócio -, diferentes das classificações propostas em estudos anteriores.

  1. Melhoria da eficiência energética em sistemas motrizes industriais

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    Antonio Vanderley Herrero Sola

    2015-09-01

    Full Text Available A comunidade científica internacional tem considerado o uso eficiente de energia em sistemas de produção extremamente importante para o desenvolvimento sustentável. Este artigo estuda a melhoria da eficiência energética em sistemas motrizes industriais por meio de mudança tecnológica. Inicialmente é feita uma revisão de literatura para apresentar as principais ações e barreiras para a melhoria da eficiência energética em sistemas industriais de energia e também destacar o uso de uma abordagem multicritério em caso de mudança tecnológica. O artigo apresenta um estudo de caso em uma indústria com o objetivo de ordenar motores elétricos para serem substituídos utilizando o método multicritério PROMETHEE II. O estudo revela que a escolha dos critérios pode alterar a ordem de prioridade de escolha das tecnologias a serem substituídas, com impacto no desempenho das novas tecnologias. O artigo enfatiza a importância da integração de todas as áreas da empresa para que sejam atendidos os interesses da organização.

  2. Políticas Industriais e de Ciência, Tecnologia e Inovação na Irlanda: Ênfase em Setores de Alta Tecnologia e Comparação com o Brasil

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    Eduardo Strachman

    2012-11-01

    Full Text Available From a theoretical foundation favorable to industrial policies, this paper intends to show the main policies followed by Ireland since the 1950s, with a special emphasis on those directed to Science, Technology and Innovation (S,T&I, FDI and high tech sectors, like software and biotechnology. We compare these policies with those used in Brazil, in a similar period, in order to have some hints for virtual transformations of current Brazilian policies. We conclude that the compromise of the State with the direction of the development and the continuity of industrial policies is very important to a solid building of comparative advantages in technologically dynamic sectors.A partir de um referencial teórico consistente, este trabalho busca montar um quadro de referências das políticas industriais adotadas pela Irlanda, desde a década de 1950, com especial ênfase sobre aquelas direcionadas para C,T&I, IDE e setores de alta tecnologia, como software e biotecnologia. Comparam-se estas políticas com aquelas adotadas pelo Brasil, em período semelhante, a fim de iluminar virtuais reformulações destas. Conclui-se que o comprometimento do Estado com a orientação do desenvolvimento e a continuidade das políticas industriais é muito importante para a construção de vantagens comparativas em setores de grande dinamismo tecnológico.

  3. Considerações sobre estudos de ambientes industriais e não industriais no Brasil: uma abordagem comparativa Comments on studies of industrial and non-industrial environments in Brazil: a comparative approach

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    Adriana Gioda

    2003-10-01

    Full Text Available A qualidade do ar em ambientes industriais tem sido palco de estudos desde a segunda metade do século XX. Resultados bem documentados apontaram que a exposição prolongada a poluentes químicos, proveniente do consumo, produção, armazenamento etc., pode causar danos à saúde do trabalhador. Recentemente, estudos direcionados a ambientes não industriais mostraram correlações surpreendentes entre a qualidade do ar e os efeitos causados à saúde. O sistema de ventilação artificial tem sido a principal causa de reclamações e de um alto índice de absenteísmo. Os sintomas relacionados com a qualidade do ar em ambientes não industriais são reconhecidos pela Organização Mundial da Saúde que os identifica como "Síndrome dos Edifícios Doentes". No Brasil, há poucos estudos relacionando qualidade do ar em ambientes fechados e saúde. O presente trabalho pretende mapear as pesquisas já realizadas no País, visando, com isso, incentivar novos estudos nessa área, em virtude de sua importância para a saúde da população.Air quality in industrial environments has been studied since the second half of the 20th century. Well-documented results show that exposure to chemical pollutants through their consumption, production, and storage can damage workers' health. New research focusing on non-industrial environments has shown unexpected correlations between air quality and health effects. Artificial ventilation systems have been related to health-related complaints and a high rate of absenteeism. Symptoms related to air quality in non-industrial environments are recognized by the World Health Organization and encompassed under the so-called sick building syndrome (SBS. In Brazil there are few studies comparing indoor air quality and health. The present study is intended to map the studies already conducted in Brazil in order to encourage further research in this area, due to its importance for public health.

  4. ENERGIA SOLAR TÉRMICA: INOVAÇÃO EM AQUECIMENTO DE ÁGUA PARA PROCESSOS INDUSTRIAIS / SOLAR THERMAL ENERGY: WATER HEATING INNOVATION FOR INDUSTRIAL PROCESSES

    Directory of Open Access Journals (Sweden)

    E. F. Carreira Junior

    2014-12-01

    Full Text Available O aumento do consumo mundial de energia tem gerado a busca de fontes alternativas, inclusive a solar, de fácil utilização, não exigindo equipamentos muito sofisticados nem complexos. Muitos processos industriais utilizam água em temperaturas até 100°C. O uso de energia solar na indústria ainda é baixo se comparado ao consumo energético total. O objetivo deste artigo é investigar possibilidades de usos de aquecimento solar de água em processos industriais, para o que foi utilizada pesquisa bibliográfica em artigos internacionais visando identificar o estágio atual dessas aplicações no mundo. Pesquisa exploratória de dados secundários do mercado brasileiro de sistemas de aquecimento solar no Departamento Nacional de Aquecimento Solar (DASOL, e no Plano Nacional de Eficiência Energética 2010-2030 (PNEf-2010 do Ministério de Minas e Energia, buscou caracterizar o estágio atual desse setor no Brasil. O estudo permite concluir que o uso de aquecimento solar de água em indústrias no Brasil é possível e representa uma alternativa que pode contribuir para a redução do custo e do consumo de energia em 30% a 40% dos processos de aquecimento em baixas temperaturas, especialmente nos setores de alimentos, bebidas, têxtil e químico.

  5. INTEROPERABILIDADE DE FERRAMENTAS DE MODELAGEM PARAMÉTRICA EM PROJETOS INDUSTRIAIS

    Directory of Open Access Journals (Sweden)

    Ezequiel Rosa Dias

    2015-11-01

    Full Text Available Este trabalho resulta de uma pesquisa de mestrado que investigou a troca de dados entre diferentes ferramentas BIM utilizadas por um grupo de empresas de Belo Horizonte na elaboração de projetos industriais. As principais fontes da pesquisa exploratória foram entrevistas não estruturadas e análises de documentações. Verificou-se que as empresas utilizam a modelagem 3D principalmente para visualização e verificação de interferências construtivas. As mesmas se encontram focadas na resolução de problemas de interoperabilidade em função da utilização simultânea de ferramentas BIM e de modelagem paramétrica industrial, mescla que pode induzir o uso de novas tecnologias pelo setor AEC à medida que projetos mais complexos são desenvolvidos pelo setor. A interoperabilidade entre os softwares utilizados ocorre preferencialmente por links diretos e padrões proprietários, em virtude de inexistência de definições normativas, fato que requer iniciativas de harmonizações entre padrões como IFC, CIS/2 e ISO-15926. Este estudo mostra que as disciplinas de projeto compõem um modelo digital 3D integrado. Contudo, o modelo integrado não dispõe de características paramétricas suficientes para o emprego de simulações do empreendimento como um todo. Para a gestão da modelagem, as empresas adotam uma ferramenta própria para criação de objetos paramétricos, tradução de modelos entre ferramentas não interoperáveis e gestão de listas de materiais. A pesquisa possibilitou a compilação do fluxo da troca de dados entre softwares, com a discriminação das linguagens utilizadas, das fases de projetos e das equipes envolvidas.

  6. Avaliação da qualidade da água de consumo por comunidades ribeirinhas em áreas de exposição a poluentes urbanos e industriais nos municípios de Abaetetuba e Barcarena no estado do Pará, Brasil

    Directory of Open Access Journals (Sweden)

    Adaelson Campelo Medeiros

    2016-03-01

    Full Text Available Resumo Apesar dos grandes avanços tecnológicos introduzidos nos processos de tratamento das águas de consumo humano, as utilizadas para abastecimento tornaram-se um grande problema de saúde pública. O objetivo deste estudo foi avaliar a qualidade das águas consumidas em duas comunidades ribeirinhas no Estado do Pará expostas a poluentes domésticos e industriais. Foram realizadas quatro campanhas de amostragem nas duas comunidades e as variáveis utilizadas para o cálculo do Índice de Qualidade da Água (IQA foram pH, Sólidos Totais, Cloreto, Fluoreto, Dureza e N-Nitrato. As águas utilizadas para consumo humano na Comunidade Maranhão, onde não há contaminação por poluentes industriais, apresentaram amostras adequadas, com melhora no período seco; já as águas de Vila do Conde, local próximo à atividade industrial, estiveram em ambos os períodos sazonais com qualidade inaceitável para consumo humano. Os principais parâmetros afetados foram o pH e o N-Nitrato, com valores até 25 vezes a referência da legislação brasileira para água de consumo humano. Esses resultados indicaram maior interferência antrópica no entorno da Vila do Conde em Barcarena, necessitando-se de avaliações clínicas por profissionais especializados sobre o estado de saúde desta população.

  7. Decomposição estrutural da variação do emprego nos setores industriais no brasil entre os anos de 2000 e 2009

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    Carina Diane Nakatani-Macedo

    2015-08-01

    Full Text Available RESUMO O objetivo do presente artigo é analisar a variação de emprego nos setores industriais nos anos 2000-2009 para o Brasil. Utiliza-se a metodologia de insumo-pro­duto, através da decomposição estrutural da variação do emprego em efeitos de intensidade, de tecnologia, da demanda, do crescimento e total. Os principais resultados mostraram que entre os dois períodos estudados, houve um acréscimo de 4,39 milhões de vagas para o setor industrial que isoladamente foi responsável por, aproximadamente, 25% do resultado nacional. Dentre os efeitos estudados pode-se destacar o efeito crescimento e intensidade como principal responsável pelos resultados. Ao considerar o efeito total, os setores que apresentaram maior crescimento relativo no número de empregos foram os de alimentos e bebidas, artigos do vestuário e acessórios e construção civil. Os resultados obtidos permitiram concluir que houve um aumento do número de postos de trabalho para a indústria no Brasil no período analisado, onde a tecnologia, apesar de não explicar unicamente o efeito crescimento, mostra impactos positivos na geração de emprego no efeito total.

  8. A Globalização e os Novos Espaços Industriais : A Indústria de Calçados da Paraíba

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    José Antonio Rodrigues da Silva

    2011-05-01

    Full Text Available Nos últimos anos, globalização tornou-se uma palavra-chave para a organização do nosso pensamento acerca das mudanças na economia mundial contemporânea. Observa-se que o processo de globalização está conduzindo a uma profunda reorganização do capitalismo e do papel que determinadas áreas geográficas, como Estados ou regiões, desempenham dentro do sistema. Como resultado, o interesse no papel das economias externas e dos efeitos de cooperação no desenvolvimento regional cresceu expressivamente nos anos 90, influenciado pelo sucesso da experiência italiana de distritos industriais de pequenas firmas. Muitos estudos de caso têm mostrado que a aglomeração produz uma eficiência coletiva que pode ajudar as pequenas empresas locais a superarem as restrições de crescimento. Este trabalho relata os resultados de uma análise empírica de três distritos calçadistas do Estado da Paraíba (cobrindo 38 empresas. Mostrando que nesses distritos existe uma enorme heterogeneidade de tamanho e desempenho. As firmas desenvolvem diferentes tipos de flexibilidade com respeito à produção, tecnologia e a emprego, de forma que nem sempre correspondem ao tipo ideal sugerido no modelo de distrito industrial.

  9. Using radioactive tracers for the evaluation of industrial equipment; Utilizacao de tracadores radioativos na avaliacao de equipamentos industriais

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Luis Eduardo Barreira; Sa, Lidia Vasconcellos de; Sousa, Alvaro Serafim F. de [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2000-07-01

    This paper presents the radioactive tracer technique, giving as example some cases of the possible utilization developed by the Nuclear Engineering Institute, RJ, BR (Argonaut reactor) and through charged particle (CV-28 cyclotron), and also his production and aspects of radiological safety.

  10. AVALIAÇÃO DO GPR NA ESTIMATIVA DA BATIMETRIA DE UMA CAIXA DE DECANTAÇÃO EMPREGANDO O APLICATIVO GRATUITO “GPR BATHYMETRY” NA ANÁLISE DOS RADARGRAMAS

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    Sandro Henrique de Faria

    Full Text Available Este trabalho tem como objetivos avaliar o desempenho do GPR (Ground Penetrating RADAR para aplicações batimétricas em ambiente controlado e do aplicativo “GPR Bathymetry”, desenvolvido para análise de radargramas batimétricos. O estudo foi realizado em uma caixa de decantação da estação de tratamento de água da qual se tem o “as-built”, obtido com estação total, que será empregado nos testes de validação. Realizaram-se três testes de comparação: comparações pontuais; entre Modelos Digitais de Elevação (MDE gerados a partir do interpolador Topo to Raster; e entre os volumes calculados a partir dos MDE’s. Na comparação pontual a maior amplitude de discrepância entre as médias foi de 8cm. Para a amostra de discrepâncias entre os MDE’s, a amplitude foi de 9cm, média de 2cm, acurácia estimada de 4cm e o RMS de 3cm. Na comparação volumétrica obteve-se o valor de 800,6m³ com dados de referência e 806,4m³ com dados do GPR, resultando numa diferença de 1% entre os modelos. Conclui-se que para um reservatório construído em concreto armado, profundidades variando de 3 a 3,5 metros, o levantamento do relevo submerso empregando um GPR apresentou resultados promissores e um MDE com acurácia estimada de 4cm e discrepâncias de até 9cm

  11. Análise desagregada da inflação por setores industriais da economia brasileira entre 1996 e 2011

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    Carlos Pinkusfeld Monteiro Bastos

    2015-08-01

    Full Text Available RESUMO Este artigo reporta uma investigação empírica sobre a dinâmica inflacionária de dezessete setores industriais da economia brasileira entre 1996 e 2011. A partir de uma breve discussão teórica sobre a relação entre a inflação e a demanda agregada nas abordagens convencional (modelo do Novo Consenso, pós-keynesiana e do conflito distributivo, buscaram-se evidências de inflação de excesso de demanda e de pressões de custo nesses setores. As séries temporais utilizadas foram o Índice de Preço ao Produtor Amplo por Origem (IPA-OG, o grau de Utilização da Capacidade Instalada (ambos da FGV, o Índice deCommodities Internacionais (IFS/FMI, a taxa de juros e a taxa de câmbio nominal (ambas do Banco Central do Brasil − BCB. As equações foram estimadas a partir da Metolodogia ADL (Autoregressive Distributed Lags . Os resultados apontaram para a ausência de uma relação forte e sistemática entre a inflação e a demanda agregada e para evidência de pressões de custo, sobretudo os preços internacionais das commodities e o câmbio, como determinantes da dinâmica inflacionária dos setores e período analisados.

  12. O LUGAR DA MORADIA SOCIAL

    OpenAIRE

    Daniela das Neves Alvarenga; Paulo Romano Reschilian

    2017-01-01

    Objetivou-se com este artigo analisar o processo de segregação socioespacial nas cidades industriais europeias, com olhar na localização da moradia operária no espaço urbano. A partir desta análise, parte-se para a construção do cenário no Brasil, apontando as origens da habitação social nas cidades industriais, com enfoque na inserção urbana da moradia produzida pela iniciativa privada e pelo Estado até os dias atuais, culminando na produção de interesse social vinculada ao programa habitaci...

  13. Avaliação do impacto ambiental e caracterização geoquímica de contaminantes em solo e água subterrânea na área do aterro de resíduos industriais da UTRESA na região do Vale dos Sinos, em Estância Velha, RS

    OpenAIRE

    Pedro Valter Augustin Junior

    2011-01-01

    A contaminação de resíduos industriais é um grande problema ambiental relacionado ao desenvolvimento industrial e urbano atual. A região do Vale dos Sinos, RS tem um histórico preocupante no gerenciamento e na destinação final de resíduos industriais ali gerados. Este estudo foi realizado na Central de resíduos da UTRESA, no município de Estância Velha, e teve como objetivo o diagnóstico ambiental e a caracterização do comportamento geoquímico de contaminantes em solo e águas subterrâneas. A ...

  14. Biodiversity and phylogenetic analysis of culturable bacteria indigenous to Khewra salt mine of Pakistan and their industrial importance Biodiversidade e análise filogenética de bactérias cultiváveis indígenas da mina de sal Khewra, Paquistão e sua importância industrial

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    Nasrin Akhtar

    2008-03-01

    Full Text Available Culturable bacterial biodiversity and industrial importance of the isolates indigenous to Khewra salt mine, Pakistan was assessed. PCR Amplification of 16S rDNA of isolates was carried out by using universal primers FD1 and rP1and products were sequenced commercially. These gene sequences were compared with other gene sequences in the GenBank databases to find the closely related sequences. The alignment of these sequences with sequences available from GenBank database was carried out to construct a phylogenetic tree for these bacteria. These genes were deposited to GenBank and accession numbers were obtained. Most of the isolates belonged to different species of genus Bacillus, sharing 92-99% 16S rDNA identity with the respective type strain. Other isolates had close similarities with Escherichia coli, Staphylococcus arlettae and Staphylococcus gallinarum with 97%, 98% and 99% 16S rDNA similarity respectively. The abilities of isolates to produce industrial enzymes (amylase, carboxymethylcellulase, xylanase, cellulase and protease were checked. All isolates were tested against starch, carboxymethylcellulose (CMC, xylane, cellulose, and casein degradation in plate assays. BPT-5, 11,18,19 and 25 indicated the production of copious amounts of carbohydrates and protein degrading enzymes. Based on this study it can be concluded that Khewra salt mine is populated with diverse bacterial groups, which are potential source of industrial enzymes for commercial applications.Avaliou-se a biodiversidade e a importância industrial de bactérias indígenas da mina de sal Khewra, Paquistão. Efetuou-se a amplificação do 16S rDNA dos isolados por PCR empregando-se os iniciadores universais FD1 e rP1, e os produtos foram seqüenciados comercialmente. Essas seqüências de genes foram comparadas com outras seqüências disponíveis no GenBank a fim de encontrar seqüências relacionadas, construindo-se uma árvore filogenética para essas bactérias. Os genes

  15. Modelo para a gestão da cultura de segurança do trabalho em organizações industriais Model for safety culture management in industrial organizations

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    Anastácio Pinto Gonçalves Filho

    2012-01-01

    Full Text Available A pesquisa apresentada neste artigo teve o objetivo de desenvolver e validar um modelo para identificar o estágio de maturidade da cultura de segurança do trabalho em organizações industriais. Com a finalidade de validá-lo, o modelo desenvolvido foi aplicado em 23 empresas químicas e petroquímicas do Polo Industrial de Camaçari, Bahia, Brasil. Foram utilizados os seguintes métodos para validação do modelo desenvolvido: 1 entrevistas individuais, 2 evidências documentais, 3 entrevistas com grupo de gerentes e 4 aplicação do modelo em outro ramo de atividade diferente do ramo químico e petroquímico. O principal resultado obtido foi que o modelo desenvolvido foi validado e pode ser utilizado para identificar o estágio de maturidade da cultura de segurança em organizações industriais.The research presented in this article had the objective to develop and validate a model to identify safety culture maturity in industrial organizations. In order to validate it, the developed model was applied in 23 chemical and petrochemical companies in Camaçari, Bahia, Brazil. The following methods were used: 1. individual interviews; 2. interview with groups of safety managers; 3. documental evidence and 4. application of the model in another industrial activity. Results demonstrated that the developed model was validated and it is suitable to identify safety culture maturity in industrial organizations.

  16. Gerenciamento de resíduos sólidos industriais em uma empresa de usinagem sobre o enfoque da produção mais limpa

    OpenAIRE

    Juliana Simião

    2011-01-01

    As atividades industriais geram resíduos sólidos, de diferentes características e quantidades, que precisam ser gerenciados adequadamente para não causar poluição ambiental e danos à saúde do homem. A Lei n.o 12.305/2010, que institui a Política Nacional dos Resíduos Sólidos, estabelece a seguinte ordem de prioridade no gerenciamento dos resíduos: não geração, redução, reutilização, reciclagem, tratamento dos resíduos e disposição final ambientalmente adequada dos rejeitos. A adoção destas es...

  17. Imunodiagnóstico da leptospirose humana através do teste ELISA-IgM, empregando-se diferentes preparações antigênicas a partir de sorotipos prevalentes de Leptospira interrogans Immunodiagnostic of human leptospirosis by ELISA-IgM, employing: different antigenic preparations as from prevalent serovars of Leptospira interrogans

    Directory of Open Access Journals (Sweden)

    Marcos Vinicius da Silva

    1990-08-01

    Full Text Available Realizou-se estudo comparativo de diferentes sorotipos de Leptospira interrogans utilizados na preparação de antígenos empregados no teste ELISA, para a detecção de anticorpos da classe IgM, em amostras de soro na fase precoce e tardia da leptospirose humana. Foram utilizados dez sorotipos, escolhidos entre os que apresentaram maior reatividade na soroaglutinação microscópica (SAM, na cidade de São Paulo. Os cinco sorotipos que apresentaram melhores resultados individualmente no teste ELISA-IgM (canicola, hebdomadis, icterohaemorrhagiae, cynopteri e brasiliensis, foram também estudados em mistura antigênica. Os antígenos não tratados apresentaram maior reatividade do que os antígenos tratados com Triton X - 100 (4% à temperatura de 50ºC, durante 4 horas. O teste ELISA-IgM empregando os sorotipos não tratados, isoladamente, e em mistura antigênica, mostrou-se altamente sensível, podendo ser empregado como teste de triagem para o diagnóstico precoce da leptospirose humana. Outra aplicação do teste é permitir a detecção do início de situações epidêmicas ou de surtos, possibilitando acionar medidas de vigilância epidemiológica.A comparative study among different serovars of Leptospira interrogans was performed in order to prepare antigens to detect IgM antibodies by ELISA in early and late phase of human leptospirosis. Ten serovars were chosen among the most prevalent detected by microscopic seroagglutination (SAM in São Paulo city. Using ELISA-IgM five of them showed better results (canicola, hebdomadis, icterohaemorrhagiae, cynopteri and brasiliensis. These ones were also studied in a pool. The non-treated antigens showed higher reactivity than the Triton X-100 (4%/50ºC/4h. ELISA-IgM using individually or pool of non treated antigens proved to be reliable with high sensitivity and should be used for an earlier diagnosis of leptospirosis, as a trial test. Faster diagnostic elucidation can be useful to detect

  18. Estratégia analítica para determinação de nitrito e amônia empregando spot test e análise de imagem digital

    Directory of Open Access Journals (Sweden)

    J. L. O. Santos

    2014-11-01

    Full Text Available Neste trabalho é proposta uma estratégia simples para determinação simultânea de nitrito e amônia empregando spot test e imagem digital. O método é baseado na reação do nitrito com a sulfanilamida, formando um cátion de diazônio que posteriormente é acoplado ao dicloreto de N-(1-nafitil etilenodiamina formando uma diazo composto de coloração rósea. A determinação da amônia foi realizada empregando a reação de berthelot modificada, onde o íon amônio em presença de salicilato, nitroprussiato e hipoclorito reage formando um composto de coloração verde. Os sinais analíticos foram obtidos a partir das intensidades de coloração por imagem digital no spot test do produto da reação. Após otimizações do sistema de análise e detecção, as seguintes figuras de mérito foram obtidas: concentração linear entre 0,2 a 10,0 mg L-1 para nitrito e 1,0 a 10,0 mg L-1 para a amônia. Os limites de detecção para o nitrito e amônia foram 0,05 mg L-1 e 0,27 mg L-1, respectivamente. A estratégia proposta foi aplicada com sucesso na determinação de nitrito e amônia em amostras de água subterrânea da zona urbana da cidade de Barreiras-Ba.

  19. Comportamento de firmas industriais em fluxos de conhecimento: Uma análise para dois aglomerados produtivos

    Directory of Open Access Journals (Sweden)

    Janaina Ruffoni

    2015-12-01

    Full Text Available Resumo O tema central do artigo é o comportamento de firmas industriais em redes de conhecimentos tecnológicos. A importância de fluxos de conhecimentos é reconhecida na discussão econômica a respeito da mudança tecnológica como um elemento essencial para as firmas inovarem. O objetivo do estudo é compreender o comportamento cognitivo de firmas localizadas geograficamente próximas quando do estabelecimento de fluxos de conhecimento, considerados relevantes para seus processos de melhoria e desenvolvimento de novos produtos e processos. Foi realizada uma pesquisa de campo com o uso da metodologia Social Networks Analyses em duas aglomerações do segmento produtor de máquinas para calçados: um da Itália e outro do Brasil. Os resultados revelaram a existência de fluxos de conhecimento restritos a algumas firmas e rarefeitos, bem como diferentes comportamentos cognitivos, indicando que coexistem nos dois aglomerados firmas que desempenham papéis heterogêneos, sendo algumas bem articuladas, enquanto outras estão isoladas da rede de conhecimento tecnológico.

  20. Software para cálculo de fluxo e pressões em silos cilíndricos metálicos para armazenamento de produtos agrícolas e industriais

    OpenAIRE

    Licia Carvalho Coelho

    2016-01-01

    Este trabalho apresenta o desenvolvimento e exemplos de aplicação de um software para cálculo de fluxo e pressões em silos cilíndricos metálicos de produtos agrícolas e industriais. As propriedades dos produtos a granel variam amplamente, e consequentemente suas pressões, tanto em grandeza e distribuição. Esses cálculos são importantes para prever picos de pressões imprevisíveis que podem causar sérios danos. O software está desenvolvido em linguagem Python com embasamento nas formulações do ...

  1. DISPOSIÇÃO DE LODO DE ESGOTO NO SOLO: ESTUDO DE VIABILIDADE / USE OF SEWAGE SLUDGE IN THE AGRICULTURE: WORKABILITY STUDY

    OpenAIRE

    DANIEL B. ROSA; DURVAL R. DE PAULA JR

    2009-01-01

    É crescente no país o número de indústrias que vem se adequando às legislações ambientais e obtendo certificações ISO 14000. Estas adequações passam pelo tratamento dos efluentes industriais e domésticos oriundos de suas atividades, gerando assim os lodos das estações de tratamento de efluentes (ETE). Geralmente estes lodos são destinados a aterros sanitários industriais sem avaliar o potencial de reaproveitamento deste resíduo para outras atividades, onerando sobremaneira os custos do tratam...

  2. Resíduo industrial como matéria-prima alternativa para a produção de filtros cerâmicos refratários

    OpenAIRE

    Carvalho,A. C.; Raupp-Pereira,F.; Rodrigues Neto,J. B.; Oliveira,A. P. Novaes de

    2015-01-01

    ResumoO desenvolvimento de atividades de valorização de resíduos sólidos pode viabilizar a produção de produtos industriais com elevado potencial de reaproveitamento como fonte alternativa mineral. Atualmente, os resíduos sólidos industriais tornaram-se uma importante linha de pesquisa na área de Engenharia. Apesar disso, poucos estudos têm sido realizados com interação efetiva de parâmetros ambientais, econômicos e sociais que demonstram aplicações destas matérias-primas pela indústria de tr...

  3. Captura de poeiras finas com ciclones de recirculação electrostática : conceptualização, modelização e validação experimental

    OpenAIRE

    Paiva, Júlio José da Silva

    2010-01-01

    Esta tese realizou-se sob financiamento de uma Bolsa de Doutoramento em Empresa com a referência SFRH/BDE/15628/2006 - Fundação para a Ciência e a Tecnologia e a empresa CUF-Químicos Industriais, S. A

  4. O LUGAR DA MORADIA SOCIAL

    Directory of Open Access Journals (Sweden)

    Daniela das Neves Alvarenga

    2017-01-01

    Full Text Available Objetivou-se com este artigo analisar o processo de segregação socioespacial nas cidades industriais europeias, com olhar na localização da moradia operária no espaço urbano. A partir desta análise, parte-se para a construção do cenário no Brasil, apontando as origens da habitação social nas cidades industriais, com enfoque na inserção urbana da moradia produzida pela iniciativa privada e pelo Estado até os dias atuais, culminando na produção de interesse social vinculada ao programa habitacional Minha Casa, Minha Vida (MCMV. Por fim, será feita uma análise comparativa da localização das vilas operárias em São José dos Campos, com a inserção urbana dos empreendimentos produzidos pelo Estado.

  5. MAICAPI - metodologia para avaliação de impactos e custos ambientais em processos industriais: estudo de caso Methodology for assessment of environmental impacts and costs in industrial processes: a case study

    Directory of Open Access Journals (Sweden)

    Paulo Ricardo Santos da Silva

    2006-09-01

    Full Text Available A preservação do meio ambiente, o uso racional de recursos naturais e a mudança de postura da sociedade frente às questões ambientais têm levado as indústrias a buscar um melhor desempenho nessa área. Aliado a esses fatores, está a constatação de que a geração de rejeitos é sinônimo de perdas econômicas. Desta forma, um melhor desempenho ambiental representa ganhos financeiros para a organização. Em vista disso, este artigo apresenta a Metodologia MAICAPI, desenvolvida para avaliar os impactos e os custos ambientais de processos industriais. Sua aplicação em uma indústria metal-mecânica, fabricante de incineradores industriais, permitiu identificar quais as etapas do processo produtivo apresentam impactos ambientais críticos, revelando as operações que mais contribuem para os custos ambientais dessa empresa.Nowadays, industries are searching a better environmental performance stimulated by changes in society behavior concerning to environmental issues and reasonable use for natural resources. In addition, companies realized that they have economic losses producing wastes. So, a better environmental perfomance means financial benefits to the organization. This work presents MAICAPI Methodology developed to evaluate environmental impacts and costs in industrial processes. This methodology was applied on an incinerator machine factory and it allowed to identify process phases whose environmental impacts were critics. Besides, the methodology application also identified operations with higher environmental costs in this company.

  6. Biofiltração de compostos orgânicos voláteis e gás sulfídrico em estações de despejos industriais de processamento de hidrocarbonetos.

    OpenAIRE

    Beatrix Nery Villa Martignoni

    2007-01-01

    Neste trabalho foi estudado o tratamento simultâneo por biofiltração de emissões de compostos orgânicos voláteis, COV e gás sulfídrico, H2S, em estações de tratamento de despejos industriais, de refinaria de petróleo, ETDI. A biofiltração dos gases emanados da EDTI mostrou ser uma técnica de alta eficiência, atingindo valores de 95 a 99 % para tratamento simultâneo de COV e H2S em concentrações de 1000 e 100 ppmv, respectivamente. Foram realizados testes em 95 dias consecutivos...

  7. Water Quality Research Program: Abstracts of the International Symposium on Gas Transfer at Water Surfaces (2nd) Held in Minneapolis, Minnesota on 11-14 September 1990

    Science.gov (United States)

    1990-08-01

    layer on the surface) it is 2 - 3 times less. Many in- situ observations show that different patterns of temperature distribution in the surface water...Coeficiente de Reaeracao dos Escoamentos Naturais da Agua com o Emprego de Tracador Gasoso. M.Sc Dissertation, Universidade de Sao Paulo, EESC, Depto. de...structure. If methane is present in measurable quantities it may prove to be an excellent in- situ tracer of gas transfer. Transfer efficiency has been used

  8. Hidrocarbonetos policíclicos aromáticos em resíduos sólidos industriais: uma avaliação preliminar do risco potencial de contaminação ambiental e humana em áreas de disposição de resíduos

    Directory of Open Access Journals (Sweden)

    Cristina L. S. Sisinno

    Full Text Available A disposição adequada dos resíduos sólidos é importante para evitar que os mesmos se transformem em fonte de contaminação ambiental e humana. A NBR 10.004 - Classificação de Resíduos - lista vários hidrocarbonetos policíclicos aromáticos (HPAs e indica que, a presença de pelo menos um deles na massa bruta do resíduo é suficiente para classificá-lo como resíduo perigoso. O objetivo deste estudo foi verificar a presença de HPAs em amostras de resíduos sólidos provenientes de alguns segmentos industriais, para se obter uma avaliação preliminar do potencial de contaminação que estes resíduos podem representar, caso não recebam destino adequado. Pelo menos um dos HPAs previstos na NBR 10.004 (benzo[a]antraceno, benzo[a]pireno, benzo[b]fluoranteno, benzo[k]fluoranteno, indeno[1,2,3-c,d]pireno, criseno ou fluoranteno foi identificado em todos os resíduos estudados, classificando-os como perigosos. Nossos resultados indicam que todos os resíduos estudados continham HPAs de importância toxicológica, o que implica que sua disposição final seja feita em locais adequados para minimizar os riscos à saúde humana e ambiental oriundos das áreas de disposição de resíduos.

  9. Hidrocarbonetos policíclicos aromáticos em resíduos sólidos industriais: uma avaliação preliminar do risco potencial de contaminação ambiental e humana em áreas de disposição de resíduos

    Directory of Open Access Journals (Sweden)

    Sisinno Cristina L. S.

    2003-01-01

    Full Text Available A disposição adequada dos resíduos sólidos é importante para evitar que os mesmos se transformem em fonte de contaminação ambiental e humana. A NBR 10.004 - Classificação de Resíduos - lista vários hidrocarbonetos policíclicos aromáticos (HPAs e indica que, a presença de pelo menos um deles na massa bruta do resíduo é suficiente para classificá-lo como resíduo perigoso. O objetivo deste estudo foi verificar a presença de HPAs em amostras de resíduos sólidos provenientes de alguns segmentos industriais, para se obter uma avaliação preliminar do potencial de contaminação que estes resíduos podem representar, caso não recebam destino adequado. Pelo menos um dos HPAs previstos na NBR 10.004 (benzo[a]antraceno, benzo[a]pireno, benzo[b]fluoranteno, benzo[k]fluoranteno, indeno[1,2,3-c,d]pireno, criseno ou fluoranteno foi identificado em todos os resíduos estudados, classificando-os como perigosos. Nossos resultados indicam que todos os resíduos estudados continham HPAs de importância toxicológica, o que implica que sua disposição final seja feita em locais adequados para minimizar os riscos à saúde humana e ambiental oriundos das áreas de disposição de resíduos.

  10. Um estudo sobre a implantação de sistemas ERP: pesquisa realizada em grandes empresas industriais A study on ERP system implementation: a survey at large industrial companies

    Directory of Open Access Journals (Sweden)

    Lindomar Subtil de Oliveira

    2012-08-01

    Full Text Available A notável expansão dos sistemas ERP gerou muitas discussões entre especialistas, pesquisadores e empresários, no intuito de encontrar uma explicação para os diversos casos de sucesso e insucesso na sua implantação. O objetivo desse estudo empírico foi identificar nas 50 maiores empresas industriais atuantes no Brasil quais os principais fatores que dificultam ou contribuem para o processo de implantação de sistemas ERP. Tratou-se de uma pesquisa aplicada e exploratória. Além do levantamento bibliográfico, elaborou-se um questionário estruturado com 29 perguntas, o qual foi respondido pelos gestores de TI (tecnologia de informação das empresas selecionadas. Os resultados demonstraram que fatores relacionados às dificuldades funcionais do sistema, customização, adaptação aos processos de negócio e carências do ERP no apoio aos planos estratégicos globais foram alguns dos pontos considerados mais complexos. Essencialmente, outros fatores concernentes ao intenso treinamento, engajamento das principais lideranças, fatores humanos, sociais e culturais também foram referidos.The large utilization of ERP systems has become the scope of discussion among specialists, researchers and professionals of the area, with the purpose of finding an answer for the success and failure cases on ERP implementation. This paper aimed to present an experimental study with the 50 biggest industrial companies with activities in Brazil in order to identify the main factors that contribute or hinder ERP implementation processes. This study was characterized by an applied and exploratory research. Besides the bibliographical survey, a structured questionnaire containing 29 questions was elaborated by the researchers and then responded by the IT (Information Technology managers of the selected companies. Results showed that the factors concerning system functionality difficulties, customization, adjustment to business processes, and lack of support

  11. Estudo laboratorial do tempo de fechamento das alças e do grau de inclinação do canino, durante o procedimento de retração, empregando mecânica de arco segmentado Laboratorial study of loops closure time and degree of cuspid´s tipping, during the retraction phase, using segmented arch mechanics

    Directory of Open Access Journals (Sweden)

    Gilberto Kauling Bisol

    2010-02-01

    Full Text Available OBJETIVO: avaliar o tempo de retração e o grau da inclinação sofrida pelo canino empregando três tipos de molas ortodônticas para retração - a alça em "T", a alça em "L" e a alça em forma de gota. MÉTODOS: foram utilizados três tipos de fio - aço inoxidável da marca comercial Morelli, aço inoxidável da marca comercial 3M Unitek e liga de beta-titânio da marca comercial Ormco; todos de calibre 0,019" x 0,025". A amostra resultante da combinação dos fatores mola e fio foi submetida à avaliação em modelo de typodont específico para essa finalidade. RESULTADOS: com relação ao tempo de fechamento das alças, verificou-se que um fechamento mais lento, e consequentemente com menor liberação de forças, foi obtido com o desenho de alça em "T" e, ainda, empregando-se a liga de beta-titânio para sua confecção. No que diz respeito à inclinação gerada pelas alças, as alças em forma de gota promoveram uma inclinação dentária maior do que as demais avaliadas. As alças em "T", por outro lado, mantiveram-se relacionadas estatisticamente aos menores valores de inclinação. Porém, quando se empregou o fio de aço inoxidável da marca comercial 3M Unitek para sua confecção, os três tipos de alça não apresentaram diferença estatisticamente significante. CONCLUSÃO: independentemente do desenho de alça empregado, aquelas construídas com liga de beta-titânio mantiveram-se relacionadas estatisticamente aos menores valores de inclinação observados para o elemento dentário movimentado.OBJETIVE: Evaluate the cuspid's retraction time and tipping effects, after submitting it to three different orthodontic retraction loops: the "T" loop, the "boot" loop, and the "tear drop" loop. METHODS: It was used the following orthodontic wires: Morelli 0.019" x 0.025" stainless steel, 3M Unitek 0.019" x 0.025" stainless steel and Ormco 0.019" x 0.025" beta-titanium (TMA™. The resulting sample from the combination of these

  12. Resistência mecânica de compósitos cimentícios leves utilizando resíduos industriais e fibras de sisal Mechanical resistence of lightweight cement composites utilizing industrial residues and fibers of sisal

    Directory of Open Access Journals (Sweden)

    Nivaldo T. de Arruda Filho

    2012-08-01

    Full Text Available A valorização de materiais alternativos incorporados com resíduos como opção ao convencional deve possibilitar a geração de um produto com qualidade, estética, produtividade e com potencial de reduzir impactos da poluição ambiental. Este trabalho foi realizado com o objetivo de desenvolver elementos construtivos para forro e divisórias, a partir de matrizes cimentícias com incorporação de resíduos industriais (resíduo cerâmico, etil vinil acetato - EVA e fibras de sisal. Desenvolveram-se técnicas de moldagem em matrizes cimentícias autoadensáveis e se avaliou a resistência mecânica dos novos compósitos. Uma placa com resíduos de EVA foi produzida e, através de trabalhos de reologia, encontrou-se a pasta matriz de revestimento desta placa, com teor adequado de adições pozolânicas e aditivo superplastificante. Avaliaram-se as resistências mecânicas das placas, da pasta matriz de revestimento encontrada, com e sem adição de fibras, e do novo compósito formado pela união desses dois elementos. Utilizou-se a técnica de alinhamento de fibras com o intuito de incrementar resistência ao novo compósito leve. A adição da matriz com fibras alinhadas melhorou a resistência a flexão do novo compósito.The appreciation of alternative materials incorporated in waste as an option to conventional material should enable to generate a product with quality, aesthetics, productivity and reduce the potential impacts of environmental pollution. This study aims to develop constructive elements for ceilings and walls from cementitious matrix incorporating industrial waste (ceramic waste, ethyl vinyl acetate - EVA and sisal fibers. Moulding techniques to produce self-compacting cementitious matrices were developed and the strength of the new composites were evaluated. A plate with EVA waste was produced and through rheology studies, a matrix plaster for coating of plate surface was found, with appropriate content of pozzolanic and

  13. Estudo numérico do comportamento de estacas carregadas lateralmente

    OpenAIRE

    Rosa González, Jorge de la

    2014-01-01

    Neste trabalho estuda-se o problema da interação solo-estrutura, vinculado ao comportamento de fundações profundas tipo estaca isolada, carregadas lateralmente de forma monotônica, empregando a Modelagem Numérica e Constitutiva, a Teoria da Plasticidade e o Método dos Elementos Finitos (M.E.F). Consideram-se as principais deficiências que os métodos analíticos não têm conseguido resolver e empregam-se adequados modelos constitutivos tanto para o solo (Modelagem Geotécnica) como para as estaca...

  14. Utilização da técnica de eletrofloculação para o tratamento de efluentes têxteis: uma revisão

    Directory of Open Access Journals (Sweden)

    Leandro Fleck

    2013-12-01

    Full Text Available Nos últimos anos o desenvolvimento de atividades industriais tem provocado inúmeros impactos aos recursos naturais. A indústria têxtil gera elevada quantidade de efluente, devido à grande utilização de água em seu processo produtivo, que quando não corretamente tratado deteriora a qualidade da água do curso hídrico receptor. Diante das formas tradicionais de tratamento de efluentes, a eletrofloculação surge como uma técnica inovadora. Tal processo constitui na passagem de corrente elétrica através de uma célula eletrolítica, originando dois processos distintos: eletrocoagulação e eletroflotação. O presente artigo tem como objetivo apresentar uma revisão bibliográfica acerca da utilização da técnica de eletrofloculação para o tratamento de efluentes industriais, com enfoque ao efluente têxtil. A forte coloração é a característica predominante em efluentes têxteis, como conseqüência da utilização de corantes para o tingimento do tecido. Devido a sua toxicidade e baixa biodegradabilidade, a presença de corantes causa inúmeros impactos aos seres vivos, o que justifica a busca por métodos alternativos para remoção desses constituintes. Atualmente não se encontram na literatura muitos estudos relacionados à aplicação da técnica de eletrofloculação para o tratamento de efluentes industriais. O pequeno número de estações de tratamento por eletrofloculação no Brasil torna-se um obstáculo para sua disseminação em grande escala. Entretanto, os resultados positivos alcançados em estudos prévios demonstram que a aplicabilidade da técnica de eletrofloculação será ampliada para o tratamento em grande escala de efluentes provenientes de atividades industriais potencialmente poluidoras.

  15. ANÁLISE DESCRITIVA QUANTITATIVA DE BUTTERMILK PROBIÓTICO

    Directory of Open Access Journals (Sweden)

    Adriane Elisabete Costa ANTUNES

    2012-12-01

    Full Text Available O buttermilk é uma bebida produzida a partir da fermentação do leitelho ou do leite, empregando-se Culturas Aromáticas Mesofílicas. Esse produto pode representar um novo veículo para culturas probióticas e conquistar nicho de mercado no Brasil. Objetivou-se no presente trabalho determinar o perfil sensorial de amostras de buttermilk probiótico sabor morango adoçadas com sacarose ou sucralose em comparação com iogurte light comercial empregando-se Análise Descritiva Quantitativa. O produto foi avaliado por análises microbiológicas, físico-químicas e de viscosidade, caracterizando-se como produto seguro do ponto de vista microbiológico, com baixo teor de lipídios e pouco viscoso. A amostra de buttermilk com sucralose diferiu da amostra com sacarose (p<0,05 por apresentar sabor residual de edulcorante e maior intensidade de doçura. Ambas as amostras de buttermilk caracterizaram-se por possuir sabor amanteigado, sensação de picância e de efervescência, que são características típicas do produto e o diferenciaram do iogurte comercial. A contagem de Bifidobacterium animalis no produto final foi de 8,5 log UFC/mL, estando acima do limite mínimo estabelecido na legislação brasileira para alimentos funcionais.

  16. Estudo da reciclagem do banho de caleiro de pele caprina

    OpenAIRE

    Sampaio, António Manuel Pinheiro

    2008-01-01

    Mestrado em Engenharia Química Nos dias que correm cada vez mais o ambiente é um factor preocupante, levando assim a que se procurem medidas e/ou alternativas mais limpas nos processos industriais. Sendo do conhecimento global que a industria dos curtumes é uma industria fortemente poluidora, consumindo elevadas quantidades de água e ao mesmo tempo produzindo elevados caudais de efluentes líquidos alcalinos ricos em sulfuretos, procurou-se minimizar o consumo de água e de reagentes reco...

  17. Crescimento urbano e poluição hídrica na zona norte de Londrina – PR

    OpenAIRE

    Fábio César Alves da CUNHA

    1999-01-01

    Estudou-se neste trabalho o crescimento urbano que se efetivou na área drenada pelos ribeirões Quatí e Lindóia, localizados na zona norte da cidade de Londrina, assim como verificou-se a poluição hídrica por efluentes residenciais e industriais nesses dois ribeirões. A questão da carência de saneamento básico nessa porção da cidade também foi tratada. Os dados obtidos permitiram um zoneamento hídrico-ambiental dos cursos hídricos envolvidos e a elaboração de algumas propostas objetivando mini...

  18. A intervenção do design no desenho da rota da cerveja

    OpenAIRE

    Lima, Tiago André Leones

    2017-01-01

    O estudo que aqui se apresenta, reflete a importância de uma abordagem a partir do design no desenvolvimento do projeto Rota da Cerveja, um roteiro nacional que pretende abarcar as cervejas artesanais portuguesas, espaços e eventos com maior relevância para este produto. A cerveja artesanal floresce como uma nova realidade de consumo nos hábitos dos portugueses. Outrora habituados e conduzidos ao consumo de cervejas industriais pouco distintas entre si, a cerveja artesanal apresenta-se como u...

  19. ECONOMIA CRIATIVA E LIDERANÇA CRIATIVA: UMA ASSOCIAÇÃO (IM) POSSÍVEL?

    OpenAIRE

    Felipe Carvalhal; Henrique Muzzio

    2015-01-01

    RESUMO Atuando em uma economia caracterizada por indivíduos criativos, fontes de vantagem competitiva e crescimento nas economias pós-industriais, os líderes das organizações assumem enorme importância no ambiente competitivo atual, tornando-se um diferencial, visto que o estilo de liderar reflete sobre o desempenho da organização. Diante disso, este artigo procurou analisar a liderança exercida por gestores da economia criativa, com vistas à liderança criativa. Especificamente buscou-se conh...

  20. Uso de resíduos industriais na remediação de solo contaminado com cádmio e zinco

    Directory of Open Access Journals (Sweden)

    Marcio Osvaldo Lima Magalhães

    2011-06-01

    Full Text Available Este trabalho teve como objetivo avaliar a utilização de dois resíduos industriais na redução de disponibilidade de zinco e cádmio em solo contaminado. O experimento foi conduzido em casa de vegetação na Universidade Federal Rural do Rio de Janeiro por 225 dias, utilizando-se um substrato contaminado com zinco e cádmio, coletado no pátio de minério do Porto de Itaguaí, e próximo ao local de disposição de resíduo perigoso da Cia Mercantil e Industrial Ingá em Itaguaí, RJ. O substrato foi tratado com dois agentes inertizantes, assim descritos: um resíduo industrial com característica alcalina (Escória de Aciaria em duas doses 4 e 6%, e outro com alto teor de óxido de ferro como adsorvente (Carepa de Laminação, em dose única de 1%. Após o plantio das mudas de Eucalyptus urophylla, foram feitas coletas do substrato em cada unidade experimental para determinação das frações biodisponíveis (extraído com MgCl2 e a não disponível. O substrato não tratado apresentava alto teor de cádmio e zinco na fração biodisponível. Os tratamentos causaram uma redução na disponibilidade desses elementos no solo, evidenciado na absorção diferenciada pelas plantas. Por causa da maior disponibilidade do cádmio e zinco no solo sem adição dos inertizantes, as plantas não resistiram aos altos teores desses elementos e morreram 30 dias após a implantação do experimento. A produção de massa seca foi influenciada positivamente pela aplicação dos agentes inertizantes, apresentando melhor resposta na maior dose de escória de aciaria. A maior dose também propiciou as menores concentrações dos elementos nas plantas, sem provocar deficiência do micronutriente zinco e mantendo o cádmio a níveis não tóxicos para as espécies de eucalipto. Apesar de apresentar menores concentrações de cádmio na dose de 6% de Escória de Aciaria,essa dose resultou na maior extração desse elemento pelas plantas.

  1. Optical studies of CdSe/HgSe and CdSe/Ag2Se core/shell nanoparticles embedded in gelatin

    International Nuclear Information System (INIS)

    Azhniuk, Yu M; Dzhagan, V M; Valakh, M Ya; Raevskaya, A E; Stroyuk, A L; Kuchmiy, S Ya; Zahn, D R T

    2008-01-01

    CdSe/HgSe and CdSe/Ag 2 Se core-shell nanoparticles are obtained by colloidal synthesis from aqueous solutions in the presence of gelatin. Optical absorption, luminescence, and Raman spectra of the nanoparticles obtained are measured. The variation of the optical spectra of CdSe/HgSe and CdSe/Ag 2 Se core-shell nanoparticles with the shell thickness is discussed. Sharp non-monotonous variation of the photoluminescence spectra at low shell coverage is observed.

  2. DISPOSIÇÃO DE LODO DE ESGOTO NO SOLO: ESTUDO DE VIABILIDADE / USE OF SEWAGE SLUDGE IN THE AGRICULTURE: WORKABILITY STUDY

    Directory of Open Access Journals (Sweden)

    DANIEL B. ROSA

    2009-11-01

    Full Text Available É crescente no país o número de indústrias que vem se adequando às legislações ambientais e obtendo certificações ISO 14000. Estas adequações passam pelo tratamento dos efluentes industriais e domésticos oriundos de suas atividades, gerando assim os lodos das estações de tratamento de efluentes (ETE. Geralmente estes lodos são destinados a aterros sanitários industriais sem avaliar o potencial de reaproveitamento deste resíduo para outras atividades, onerando sobremaneira os custos do tratamento dos efluentes, perdendo-se excelente oportunidade para incremento da receita do gerador. No entanto, para este reaproveitamento faz-se necessário o estudo criterioso dascaracterísticas lodo e sua eventual adequação ao destino pretendido. Sendo que, em muitos casos, o potencial poluidor do material pode inviabilizar qualquer tipo de reaproveitamento. Dentro deste contexto, buscando redução de custos com disposição em aterro industrial, desenvolveu-se este estudo de viabilidade, através da caracterização do lodo da ETE da unidade não industrial de uma grande montadora com o objetivo de demonstrar possíveis alternativas para a adequação desta ETE visando-se a obtenção de lodos com quantidade e qualidade que possibilitem sua estabilização e tratamento para seu uso como biossólido nas atividades agrícolas desenvolvidas por esta empresa.

  3. Turismo, entre consumo e contemplação : estudo qualitativo sobre as viagens turísticas na contemporaneidade

    OpenAIRE

    Pinto, Débora Regina Garcia

    2010-01-01

    Mediante o panorama sociocultural do fenômeno turístico contemporâneo observa-se uma realidade preocupante: o principal ator é o homem que consome, e não o que explora. Considerando que as viagens turísticas nas sociedades pré-industriais tinham um significado de desbravamento, contemplação e com foco na experiência em si, vislumbra-se hoje uma tendência da indústria do turismo, massificando as práticas e experiências de viagem, visto que na atualidade as experiências apresentam característic...

  4. Estudo de impactos ambientais em solos: o caso da reciclagem de baterias automotivas usadas, tipo chumbo-ácido

    OpenAIRE

    Fernandes, Josely Dantas; Dantas, Edilma Rodrigues Bento; Barbosa, Juliana Nóbrega; Barbosa, Edimar Alves

    2011-01-01

    A ocorrência de solos contaminados com o elemento chumbo está se tornando cada vez mais comum. Ele é, essencialmente, um contaminante ambiental e suas concentrações no meio ambiente vem aumentando de acordo com a aplicação sempre crescente em diversos produtos industriais necessários à sociedade moderna. Hoje, usa-se o chumbo, por exemplo, na fabricação de canos, em revestimentos de cabos elétricos, de chapas para pias, cisternas e telhados e, principalmente, na indústria de baterias automoti...

  5. Qualidade físico-química, microbiológica e ocorrência de micotoxinas de Alternaria alternata em derivados de tomate

    OpenAIRE

    Santos, Grazielle Gebrim

    2014-01-01

    O tomate industrial destina-se à produção de derivados, como extratos, polpas, molhos e conservas de tomate sem pele. A indústria de processamento de tomates no Brasil apresentou um grande crescimento a partir da década de 1970. O Brasil figura entre os dez maiores produtores de tomate industrial do mundo. A cultura do tomate é afetada por um grande número de doenças causadas por fungos e bactérias. Entre os fungos produtores de toxinas que acometem os tomates industriais destacam-se os do gê...

  6. Análise comparativa de métodos de cálculo para fundações de máquinas

    OpenAIRE

    Milet, Rebecca Rolim

    2006-01-01

    Os avanços tecnológicos industriais, nas últimas décadas, geraram o desenvolvimento de máquinas de alta performance e precisão que, por sua vez, têm demandado projetos otimizados de suas fundações. Cada vez mais, diversas tentativas têm que ser consideradas para se obter projetos de fundações que conciliem a máxima eficiência com custos aceitáveis. A modelagem via método dos elementos finitos se constitui uma poderosa ferramenta que pode ser utilizada para prever, de maneira ma...

  7. Classificação das barragens de contenção de rejeitos de mineração e de resíduos industriais no estado de Minas Gerais em relação ao potencial de risco

    OpenAIRE

    Anderson Pires Duarte

    2008-01-01

    Recentes acidentes envolvendo barragens de contenção de rejeitos de mineração e de resíduos industriais vêm despertando a atenção para estas estruturas, que crescem cada vez mais com o aumento da produção industrial. Atualmente, no Brasil, tudo caminha para a criação de uma Política Nacional para Segurança de Barragens, já que ainda não há uma padronização de critérios para cada fase do ciclo de vida destas estruturas. Em Minas Gerais, a FEAM (Fundação Estadual do Meio Ambiente) através da De...

  8. ZnSe/ZnSeTe Superlattice Nanotips

    Directory of Open Access Journals (Sweden)

    Young SJ

    2010-01-01

    Full Text Available Abstract The authors report the growth of ZnSe/ZnSeTe superlattice nanotips on oxidized Si(100 substrate. It was found the nanotips exhibit mixture of cubic zinc-blende and hexagonal wurtzite structures. It was also found that photoluminescence intensities observed from the ZnSe/ZnSeTe superlattice nanotips were much larger than that observed from the homogeneous ZnSeTe nanotips. Furthermore, it was found that activation energies for the ZnSe/ZnSeTe superlattice nanotips with well widths of 16, 20, and 24 nm were 76, 46, and 19 meV, respectively.

  9. Avaliação da qualidade de água de um sistema de captação de água pluvial. Estudo de caso: Laboratório de Ecologia Isotópica/CENA/USP

    OpenAIRE

    Jean Carvalho

    2014-01-01

    Devido à intensificação das atividades industriais e agrícolas, aliada ao grande crescimento urbano e ao aumento exponencial da população no último século, a pressão sobre os recursos hídricos se intensificaram drasticamente. Sendo assim, existe a necessidade de se buscar novas fontes de abastecimento público de água. A captação de água pluvial remonta a milhares de anos, no entanto, por se tratar de uma área onde os estudos são recentes, muitas dúvidas permeiam sobre o método a ser adotado p...

  10. Crescimento urbano e poluição hídrica na zona norte de Londrina – PR

    Directory of Open Access Journals (Sweden)

    Fábio César Alves da CUNHA

    1999-12-01

    Full Text Available Estudou-se neste trabalho o crescimento urbano que se efetivou na área drenada pelos ribeirões Quatí e Lindóia, localizados na zona norte da cidade de Londrina, assim como verificou-se a poluição hídrica por efluentes residenciais e industriais nesses dois ribeirões. A questão da carência de saneamento básico nessa porção da cidade também foi tratada. Os dados obtidos permitiram um zoneamento hídrico-ambiental dos cursos hídricos envolvidos e a elaboração de algumas propostas objetivando minimizar os problemas levantados.

  11. Influência de aditivos na produção de blocos cerâmicos Influence of additives on the production of ceramic bricks

    Directory of Open Access Journals (Sweden)

    R. S. Macedo

    2008-09-01

    Full Text Available A indústria oleira nacional possui uma grande importância econômica e social, movimentando bilhões de reais e empregando milhões de pessoas. No entanto, apresenta uma grande defasagem tecnológica, o que se reflete na produção de peças de baixa qualidade e em uma grande quantidade de perdas na produção. Assim, visando melhorar a qualidade dos blocos cerâmicos esse trabalho tem por objetivo analisar a influência de aditivos no comportamento de plasticidade de massas para produção de blocos cerâmicos e nas propriedades físicas dos corpos produzidos com as massas aditivadas. Foram utilizados cinco massas industriais e dez aditivos durante o estudo. Foi analisada a influência dos aditivos nos limites de Atterberg das massas e selecionados os aditivos que reduziam os limites de plasticidade. Foram preparadas formulações com os aditivos selecionados e conformados corpos de prova por extrusão. Determinou-se o módulo de ruptura à flexão após secagem e queima e a absorção de água após queima desses corpos de prova. Com base nos resultados pode-se concluir que alguns aditivos reduzem o limite de plasticidade das massas e melhoram significativamente o comportamento mecânico após secagem e após queima.The Brazilian ceramic brick industry has an important economic and social role, with a billionaire market and generating millions of jobs. However, this industry presents an outdated technology, which causes the production of low quality bodies and high production losses. Objecting improve the quality of ceramic brick this work evaluated the influence of additives on the plasticity of formulations used for the production of ceramic bricks and on the physical properties of samples produced with additive formulations. Five formulations and ten additives were studied. The influence of additives on the Atterberg limits was analyzed. Additives that reduced the plasticity limit were selected, formulations were produced and test

  12. Relacionando o planejamento de produto ao processo criativo: uma proposta

    Directory of Open Access Journals (Sweden)

    Cesar Antônio Mantovani

    2003-03-01

    Full Text Available Este trabalho apresenta algumas considerações relacionadas à criatividade da mesma manei-ra que são estabelecidas conexões entre os estágios do processo criativo e o planejamento de produtos industriais. Também se menciona sua aplicação na resolução de problemas dentro de áreas distintas: marketing; projeto; educação e produção, para tanto, é traçado um quadro comparativo com os estágios do processo criativo. Este trabalho está embasado em descri-ções de autores representativos destas áreas de conhecimento. O principal objetivo é estabe-lecer as correlações existentes entre os estágios do processo criativo com os diferentes está-gios e níveis do processo de planejamento de produto induzindo a uma proposta de universa-lização de linguagem. Palavras-chave: criatividade, processo criativo, planejamento de produtos industriais

  13. Los ancianos más viejos en el médio rural : realidad de vida y salud de uma población de lo interior gaúcho

    OpenAIRE

    Morais, Eliane Pinheiro de; Rodrigues, Rosalina Aparecida Partezani; Gerhardt, Tatiana Engel

    2008-01-01

    Trata-se de estudo epidemiológico transversal com objetivo de descrever e analisar os dados demográficos, sócio-econômicos e as condições de saúde dos idosos com 80 anos ou mais, residentes no meio rural de Encruzilhada do Sul - RS. Para coleta dos dados dos 137 idosos foram realizadas entrevistas domiciliares entre março a junho de 2006. Os dados foram analisados empregando-se estatística descritiva e inferencial. A idade média das idosas foi de 84,1 (dp= 3,8), e dos idosos, de 85,3 (dp=3,5)...

  14. Verificação do poder preditivo do spread entre as taxas de juros de longo e curto prazos na variação das taxas de curto prazo no Brasil

    OpenAIRE

    Silva, Arlete da

    2006-01-01

    A Hipótese das Expectativas (HE) é testada na Estrutura a Termo das Taxas de Juros brasileira (ETTJ) no sentido de se verificar se a inclinação da curva de juros, representada pelo spread entre as taxas de juros de longo e curto prazos, pode explicar as variações das taxas de juros de curto prazo no Brasil. Foram utilizadas séries com médias mensais das taxas de juros de um, três e seis meses, de janeiro de 1995 a janeiro de 2006, empregando metodologia baseada em regressões individuais. Os r...

  15. Desenvolvimento de eletrodos de pasta de carbono modificada com 2-aminotiazol sílica gel para a determinação de metais em etanol combustível

    OpenAIRE

    Takeuchi, Regina Massako [UNESP

    2007-01-01

    Neste trabalho foram desenvolvidos métodos eletroanalíticos para a determinação de íons metálicos em etanol combustível, empregando-se eletrodos de pasta de carbono modificada com uma sílica organofuncionalizada com grupos 2-aminotiazol (CPE-SiAt). Foi realizado um estudo comparativo entre dois aglutinantes: Nujol® e parafina; sendo observado que este último foi mais apropriado para aplicações em amostras comerciais de etanol combustível. Além da utilização dos CPE-SiAt, empregou-se também um...

  16. Projeto e desenvolvimento de uma interface de rede local para aplicações em automação industrial

    OpenAIRE

    Leonardo Appezato

    1990-01-01

    Resumo: Esta dissertação apresenta o projeto de uma interface de rede local, desenvolvida no Instituto de Automação do Centro Tecnológico para Informática. Este projeto tem uma proposta de implementação de hardware e software objetivando sua utilização em aplicações industriais. O projeto constitue-se em uma placa inteligente onde se localizam as duas camadas inferiores do Modelo de Referência OSI da ISO, implementadas de uma forma similar à especificação Mini-MAP. A subcamada MAC é do tipo "...

  17. Resíduo agroindustrial na formação de mudas ornamentais irrigadas com água residuária

    OpenAIRE

    Aline Costa Ferreira; Viviane F. Silva; Kalyne S. A. de Brito; Elka Costa Nascimento

    2014-01-01

    O reuso de água de esgoto tratada juntamente com o uso de resíduos industriais para a formação de mudas de girassol ornamental vem sendo uma alternativa econômica para o estado da Paraíba. Nesse contexto, a pesquisa foi realizada objetivando-se a utilização de resíduo agroindustrial na formação de mudas ornamentais irrigadas com água residuária. Desenvolvido em ambiente protegido na Universidade Federal de Campina Grande – UFCG, localizado no Estado da Paraíba-PB, utilizaram-se os seguintes t...

  18. Ocorrência de Oryzaephilus surinamensis Linnaeus, 1758 (Coleoptera:Ccujidae) e Necrobia rufipes De Geer, 1775 (Coleoptera:Cleridae) infestando rações de animais domésticos

    OpenAIRE

    Gredilha, Rodrigo; Saavedra, Priscilla Ribeiro; Guerim, Luciana; Lima, Aurino Florêncio de; Serra-Freire, Nicolau Maués

    2005-01-01

    Verificou-se a ocorrência de insetos associados a rações industriais para cães e gatos. Coletas simultâneas de péletes foram realizadas após a abertura dos sacos embalados na indústria e distribuídos para comercialização, no período de maio à novembro de 2003. Foram selecionadas para análise, seis diferentes tipos do total das marcas disponíveis para a venda no comércio da cidade do Rio de Janeiro. Registrou-se a incidência dos besouros Necrobia rufipes e Oryzaephilus surinamensis. The occ...

  19. Uma Visão Descentralizada do Planejamento Energético das Pequenas Centrais Hidrelétricas: A Gestão Municipal

    OpenAIRE

    Francisco de Aragão Antunes Maciel

    1996-01-01

    Nas últimas décadas, o Brasil caracterizou-se por adotar um planejamento energético centralizado, com ênfase em empreendimentos hidrelétricos de grande porte, sintonizado ao atendimento de poucos centros urbanos econômicos-industriais. Com a restruturação do papel da União, em busca de uma função de regulação de mercado, abriram-se precedentes para modelos descentralizados de desenvolvimento e gestão, em especial, no âmbito da energia elétrica, em decorrência da reformulação do sistema de co...

  20. Teor de vitamina C e características físicas do camu-camu em dois estádios de maturação

    OpenAIRE

    Sousa, Rita de Cássia Pereira de

    2011-01-01

    O Camu-Camu é uma das frutas amazônicas que está merecendo atenção pelos teores de vitamina C e sua introdução recente nos mercados mundiais. Desperta interesse de setores industriais como fármaco, cosmético, conservante natural, alimentício e da casca extrai-se corante natural (antocianinas). Considerando a importância do camu-camu como alimento, da vitamina C na dieta humana, realizou-se o presente trabalho com o objetivo de determinar o teor de vitamina C em frutos de camu-camu colhidos em...

  1. Interaction of Se and GaSe with Si(111)

    International Nuclear Information System (INIS)

    Meng, Shuang; Schroeder, B. R.; Olmstead, Marjorie A.

    2000-01-01

    Deposition of Se and GaSe on Si(111)7x7 surfaces was studied with low-energy electron diffraction, x-ray photoelectron spectroscopy, and x-ray photoelectron diffraction to probe initial nucleation and interface structure for GaSe/Si(111) heteroepitaxy. Room-temperature deposition of Se on Si(111)7x7 results in an amorphous film. Subsequent annealing leads to Se evaporation without ordering or interdiffusion. Se deposition at 450 degree sign C saturates at submonolayer coverage with no diffusion of Se into the substrate. There is no clear evidence of ordered sites for the Se. Growth of GaSe on Si(111)7x7 above 500 degree sign C results in a pseudomorphic bilayer, with Si-Ga-Se bonding. Additional GaSe does not stick to the bilayer above 525 degree sign C. The resulting Se lone pair at the surface leads to an ideally passivated surface similar to As/Si(111). This stable surface is similar to the layer termination in bulk GaSe. The single domain bilayer is oriented with the Ga-Se bond parallel to the substrate Si-Si bond. (c) 2000 The American Physical Society

  2. Estudo da influência da adição de cinzas de carvão mineral nas propriedades da cerâmica vermelha

    OpenAIRE

    Zanin,T. L.; Klitzke,W.; Luz Jr.,L. F. L.

    2013-01-01

    A adição de resíduos industriais em cerâmicas vermelhas tem sido o alvo de diversos estudos, onde se busca uma destinação final adequada ao resíduo e melhoria das características da cerâmica. Neste trabalho, avaliou-se a adição de cinzas leves de carvão mineral oriundas de uma usina termelétrica existente em Figueira, PR. Foram preparadas misturas de 0, 10, 20, 30, 40 e 50% de cinzas em argila e produzidos corpos de prova de 6 cm x 2 cm x 0,5 cm por calcinação a 950 ºC. Avaliou-se os parâmetr...

  3. Extended analyses of Se VII and Se VIII

    International Nuclear Information System (INIS)

    Vankleef, Th.A.M.; Joshi, Y.N.

    1984-01-01

    Joshi et al. (1984) have conducted an analysis of the 3d8 4s-3d8 4p transitions in As VII. The present investigation is concerned with an analysis of similar transitions in Se VIII. The selenium spectrum was photographed in the 400-1200-A wavelength region on a variety of normal-incidence spectrographs. Attention is given to least-squares-fit (LSF) and Hartree-Fock (HF) parameter values for the 3d9 4d configuration of Se VII, LSF and HF parameter values for the 3d8 4s and 3d8 4p configurations of Se VIII, the energy and composition of the levels of the 3d9 4d configuration of Se VII, classified lines in Se VII, energy levels and composition of the 3d8 4s configuration and the revised and newly determined levels of the 3d8 4p configuration of Se VIII, and newly classified lines of Se VIII. 15 references

  4. The Ag2Se-HgSe-GeSe2 system and crystal structures of the compounds

    International Nuclear Information System (INIS)

    Parasyuk, O.V.; Gulay, L.D.; Romanyuk, Ya.E.; Olekseyuk, I.D.; Piskach, L.V.

    2003-01-01

    The phase diagram of the quasi-ternary Ag 2 Se-HgSe-GeSe 2 system at 298 K was investigated using X-ray phase analysis and metallography. The formation of five intermediate quaternary phases β (Ag ∼7.12-∼6.32 Hg ∼0.44-∼0.82 GeSe 6 ), γ (Ag ∼6.08-∼4.00 Hg ∼0.96-∼2.00 GeSe 6 ), δ (Ag 3.4 Hg 2.3 GeSe 6 ), ε (Ag ∼2.24-∼2.00 Hg ∼2.88-∼3.00 GeSe 6 ) and ∼Ag 1.4 Hg 1.3 GeSe 6 was established. The crystal structure of the β-phase (for the Ag 6.504 Hg 0.912 GeSe 6 composition) was determined using X-ray single crystal diffraction. It crystallizes in a cubic structure (space group F4-bar 3m) with the lattice parameter a=1.09026(4) nm. The crystal structure of the δ-phase (Ag 3.4 Hg 2.3 GeSe 6 ) was determined using X-ray powder diffraction (space group F4-bar 3m, a=1.07767(8) nm). The crystal structure determination of the γ-phase (space group Pmn2 1 ) was performed for the compositions Ag 5.6 Hg 1.2 GeSe 6 , Ag 4.8 Hg 1.6 GeSe 6 and Ag 4 Hg 2 GeSe 6 using X-ray powder diffraction. The crystal structure of the LT-Hg 2 GeSe 4 compound (space group I4-bar , a=0.56786(2), c=1.12579(5) nm) was confirmed by powder diffraction also.

  5. Ambiente e competitividade industrial em Portugal

    OpenAIRE

    Caetano, Gonçalo

    2000-01-01

    O principal desafio que se coloca ao desenvolvimento industrial português, num enquadramento competitivo marcado, sobretudo, pela globalização e aprofundamento e alargamento da integração europeia, é, sem dúvida, o da promoção sustentada da competitividade, entendida como variável global, relativa e pluridimensional, resultante de processos económicos, tecnológicos, sociais, institucionais e políticos complexos, e caracterizadora da performance das empresas industriais.

  6. Phase diagram of Se-CaIn4Se7 system

    International Nuclear Information System (INIS)

    Musaeva, R.I.; Aliev, I.I; Ismailova, F.I; Aliev, A.A

    2011-01-01

    Full text: The Se-CaIn 4 Se 7 system has been studied using methods of differential thermal analysis, X-ray diffraction, micro structural analysis, density measurements and its phase diagram has been constructed. It has been established that the section Se-CaIn 4 Se 7 is a quasibinary section of the ternary system Ca-In-Se. At room temperature, on the basis of CaIn 2 Se 4 and Se no solid solution has been found

  7. Utilização de plasmas em pressão atmosférica para modificação de polímeros biocompatíveis

    OpenAIRE

    Lopes, Bruno Bellotti [UNESP

    2013-01-01

    Neste trabalho foi desenvolvido um equipamento para produção de plasmas em pressão atmosférica. Empregando esse sistema, o polímero PLDLA (poli(L-Co,L ácido lático)) e sua blenda com o tri(carbonato de metileno) (poli(L-Co-D,L-Co TMC)) foram hidrofilizados em diferentes condições de tempo e potência de plasma. Seus ângulos de contato foram investigados anteriormente e após cada exposição ao plasma para se avaliar o efeito do tratamento. Espectroscopia de emissão óptica foi empregada para se c...

  8. Calculos de potenciais de ionização de algumas bases e aza-analogas utilizando o metodo semi-empirico HAM/3

    OpenAIRE

    Jose Jair Vianna Cirino

    1994-01-01

    Resumo: Inicialmente procedeu-se a otimização de geometrias das bases purinas guanina, 8-azaguanjna, xantina, 8-azaxantina e hipoxantina com o uso dos métodos semi-empíricos MNDO, AMI e MNDO-PM3. Nesta etapa também fez-se uso de métodos ab initio utilizando o conjunto de base cep-31G. Os potenciais de ionização dos elétrons do caroço das bases purinas foram calculados posteriormente por meio do método semi-empírico HAM/3 empregando as geometrias otimizadas pelos métodos semi-empíricos na etap...

  9. Styrene photocatalytic degradation reaction kinetics

    OpenAIRE

    Taffarel, Silvio R.; Lansarin, Marla A.; Moro, Celso C.

    2011-01-01

    A reação de degradação fotocatalítica do estireno foi estudada utilizando-se TiO2 P-25 (Degussa) como catalisador. Os experimentos foram realizados em um reator “slurry” em bateladas, com controle de temperatura, empregando-se uma lâmpada UV. Foram estudados os efeitos do pH, da concentração inicial de estireno, da concentração do catalisador e da adição de H2O2 sobre a velocidade da reação. Os resultados mostraram que, em 90 min, cerca de 95% da quantidade inicial da molécula foi consumida p...

  10. Nordeste industrial: a fragmentação territorial de uma região periférica

    OpenAIRE

    da Silva Filho, Luís Abel; da Silva, Fábio José Ferreira; de Queiroz, Silvana Nunes

    2015-01-01

    A concentração industrial no Brasil condicionou uma série de investigações acerca de suas causas e consequências em âmbito regional e local. Diante disso, este artigo tem como objetivo analisar a concentração industrial no Nordeste brasileiro, a partir da distribuição espacial da mão de obra formal, adotado como indicador de desempenho das atividades industriais na região. Para tanto, recorre-se a revisão de literatura e, em seguida, utilizam-se métodos de análise regional. Os dados são da Re...

  11. On Some Physical Properties of GeSe3-Sb2Se3-ZnSe Thin Films and Their Radiation Response

    International Nuclear Information System (INIS)

    Hosni, H.M.M.A.

    2010-01-01

    Thin films of the chalcogenides GeSe 3 , Sb 2 Se 3 , ZnSe, (GeSe 3 )80(Sb 2 Se 3 )20 and (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20, are prepared by thermal evaporation onto glass substrates. The effect of ZnSe incorporation with both GeSe 3 , Sb 2 Se 3 results in amorphous (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20 composition as obtained from the X-ray analysis. Electrical measurements reveal a decrease in dc activation energy, ΔEdc, and an increase in ac activation energy, ΔEac, for (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20 as compared with (GeSe 3 )80(Sb 2 Se 3 )20. Optical energy gap, Eg, and band tail width, Ee, are estimated in UV/VIS spectral region for fresh and γ-irradiated films, revealing a decrease in Eg and an increase in Ee for ZnSe and (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20 compositions, with irradiation dose.

  12. Semiconductor-metal transition of Se in Ru-Se Catalyst Nanoparticles

    Science.gov (United States)

    Babu, P. K.; Lewera, Adam; Oldfield, Eric; Wieckowski, Andrzej

    2009-03-01

    Ru-Se composite nanoparticles are promising catalysts for the oxygen reduction reaction (ORR) in fuel cells. Though the role of Se in enhancing the chemical stability of Ru nanoparticles is well established, the microscopic nature of Ru-Se interaction was not clearly understood. We carried out a combined investigation of ^77Se NMR and XPS on Ru-Se nanoparticles and our results indicate that Se, a semiconductor in elemental form, becomes metallic when interacting with Ru. ^77Se spin-lattice relaxation rates are found to be proportional to T, the well-known Korringa behavior characteristic of metals. The NMR results are supported by the XPS binding energy shifts which suggest that a possible Ru->Se charge transfer could be responsible for the semiconductor->metal transition of Se which also makes Ru less susceptible to oxidation during ORR.

  13. Práticas de gestão da informação e do conhecimento em pequenas e médias empresas organizadas em rede: um estudo multicasos na indústria brasileira

    Directory of Open Access Journals (Sweden)

    Ricardo Vinícius Dias Jordão

    Full Text Available A pesquisa descrita neste artigo teve como objetivo analisar a influência da organização em rede sobre as práticas de gestão da informação e do conhecimento de pequenas e médias empresas (SMEs, do inglês small and medium-sized enterprises industriais brasileiras. Através de um estudo comparativo de casos de abordagem qualitativa entre dois seguimentos industriais, agronegócios e indústrias em geral, concluiu-se que: (1 os processos de criação, aquisição, manutenção e compartilhamento de informações e conhecimentos foram influenciados pela rede, bem como pela cultura organizacional, pela cooperação e colaboração, e pelas relações e interações existentes dentro e entre as empresas, (2 a troca de informações e experiências traz benefícios para as SMEs (3, a rede promoveu em parte a sistematização do conhecimento, mas facilitou o seu desenvolvimento, (4 o estabelecimento de um contexto favorável ('Ba' pode facilitar a criação e o desenvolvimento das habilidades desses indivíduos e empresas. Nesse sentido, observou-se que a cultura de cooperação pode ser considerada essencial no processo de aprendizagem individual e organizacional.

  14. Bio-fortification and isotopic labelling of Se metabolites in onions and carrots following foliar application of Se and 77Se

    DEFF Research Database (Denmark)

    Kápolna, Emese; Laursen, Kristian H.; Husted, Søren

    2012-01-01

    Se. The 77Se- labelled metabolites in onions were predominantly γ-glutamyl-77Se-selenomethyl-selenocysteine (γ-glu-Me77SeCys), 77Se-methylselenocysteine (Me77SeCys) and 77Se-selenomethionine (77SeMet). Furthermore, we report here for the first time the finding in carrots of the bioactive Me77SeCys...

  15. Degradação de poliolefinas utilizando catalisadores zeolíticos

    OpenAIRE

    Valle,Maria Letícia M.; Guimarães,Maria José O. C.; Sampaio,Cristiane M. S.

    2004-01-01

    Neste trabalho foi estudada a degradação de alguns dos principais constituintes dos rejeitos plásticos (polietileno de alta densidade (HDPE), polietileno de baixa densidade (LDPE) e polipropileno (PP)), empregando-se um catalisador exausto de unidades de craqueamento de fluidos (FCC) e um catalisador zeolítico (ADZ3) sintetizado em laboratório. Utilizando técnicas de termogravimetria (TG-DTG) e cromatografia gasosa (CG), foi possível avaliar os produtos gerados no craqueamento destas poliolef...

  16. One-step synthesis of PbSe-ZnSe composite thin film

    Directory of Open Access Journals (Sweden)

    Abe Seishi

    2011-01-01

    Full Text Available Abstract This study investigates the preparation of PbSe-ZnSe composite thin films by simultaneous hot-wall deposition (HWD from multiple resources. The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films. A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The optical absorption edge of the composite thin films shifts toward the low-photon-energy region as the PbSe content increases. The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

  17. Mudanças em regimes industriais e acumulação de capacidades tecnológicas: evidências de empresas de celulose e papel no Brasil Changes in industrial regimes and accumulation of technological capabilities: evidence from pulp and paper firms in Brazil

    Directory of Open Access Journals (Sweden)

    Claudia Teresa Carvajal García

    2009-12-01

    Full Text Available A despeito da profusão de estudos sobre capacidade tecnológica em nível de empresas ao longo dos últimos 30 anos, há escassez de estudos sobre similaridades e diferenças entre empresas do mesmo setor industrial, em termos de acumulação de capacidades tecnológicas e suas implicações para o aprimoramento de indicadores de performance técnico-econômica ao longo de diferentes regimes industriais, especialmente no contexto de países de industrialização recente, como é o caso do Brasil. Baseando-se em evidências de primeira mão colhidas à base de extensivos trabalhos de campo, este artigo examina essas questões em três grandes empresas de celulose e papel no Brasil (1970-2004. O estudo encontrou: (1 Diferenças inter e intraempresariais em termos da maneira e velocidade de acumulação de capacidades para funções tecnológicas específicas ao longo dos diferentes períodos; (2 Tais diferenças refletiram-se, com diferentes graus de intensidade, no aprimoramento dos indicadores de performance técnico-econômica; (3 As empresas responderam positivamente às mudanças para uma economia aberta partir dos anos 1990; (4 Porém, os aprimoramentos em seus indicadores de performance técnico-econômica não derivaram das mudanças do regime industrial per se, mas, principalmente, dos seus esforços internos para acumulação tecnológica.Despite the profusion of studies of firm-level technological capabilities studies, over the past 30 years, there is a scarcity of analyses on similarities and differences across firms, of the same industrial sector, in terms of types and levels, direction and rate of accumulation of technological capabilities and their implications for the improvement of techno-economic performance across different industrial regimes, especially in the context of late-industrializing countries, as it is the case of Brazil. Based on first-hand qualitative and quantitative empirical evidence, collected on the basis of

  18. Avaliação clínica e radiográfica do tratamento endodôntico em sessão única de dentes com lesões periapicais crônicas

    OpenAIRE

    SOARES Janir Alves; CÉSAR Carlos Augusto Santos

    2001-01-01

    Este estudo teve como objetivo avaliar a incidência de dor pós-operatória e o tipo de reparação periapical, após tratamento endodôntico em sessão única, em pacientes portadores de polpa necrótica associada a áreas radiolúcidas periapicais, assintomáticos. Para tanto, após o preparo biomecânico empregando-se a técnica "step down" seguido por "step back", auxiliada por copiosa irrigação com solução de hipoclorito de sódio a 5,0%, procedeu-se à obturação dos canais radiculares pela técnica conve...

  19. Clinic and radiographic evaluation of one-appointment root canal therapy in teeth with chronic periapical lesions

    OpenAIRE

    SOARES, Janir Alves; CÉSAR, Carlos Augusto Santos

    2001-01-01

    Este estudo teve como objetivo avaliar a incidência de dor pós-operatória e o tipo de reparação periapical, após tratamento endodôntico em sessão única, em pacientes portadores de polpa necrótica associada a áreas radiolúcidas periapicais, assintomáticos. Para tanto, após o preparo biomecânico empregando-se a técnica "step down" seguido por "step back", auxiliada por copiosa irrigação com solução de hipoclorito de sódio a 5,0%, procedeu-se à obturação dos canais radiculares pela técnica conve...

  20. Passivation of iron in solutions containing borate using rotating ring-disc measurements

    OpenAIRE

    Martini, Emilse M.A.; Muller, Iduvirges L.

    1999-01-01

    Investigou-se o comportamento eletroquímico do ferro em soluções neutras de perclorato de sódio contendo pequenas concentrações de borato de sódio, através da técnica de voltametria cíclica e empregando-se eletrodo rotatório de disco e anel. Nas soluções de perclorato, a passivação do ferro ocorreu após o pico anódico correspondente à zona ativa, no qual foi observada a dissolução de espécies Fe2+ e Fe3+. Quando é adicionado borato à solução, tanto a densidade de corrente do pico anódico quan...

  1. A Concise Total Synthesis of (R)-Fluoxetine, a Potent and Selective Serotonin Reuptake Inhibitor

    OpenAIRE

    de Fátima, Ângelo; Lapis, Alexandre Augusto M.; Pilli, Ronaldo A.

    2005-01-01

    (R)-Fluoxetine, potent and selective serotonin reuptake inhibitor, has been synthesized in six steps, 50% overall yield and 99% ee from benzaldehyde via catalytic asymmetric allylation with Maruoka's catalyst. (R)-Fluoxetina, um inibidor potente e seletivo da recaptação da serotonina, foi sintetizada em seis etapas, 50% de rendimento total e 99% de excesso enantiomérico a partir do benzaldeído via alilação catalítica assimétrica empregando-se o sistema catalítico desenvolvido por Maruoka e...

  2. A digitalização tridimensional móvel e sua aplicação no design de produto

    Directory of Open Access Journals (Sweden)

    Fabio Pinto da Silva

    2010-09-01

    Full Text Available A alta competitividade e a busca por novas tecnologias que diferenciem os produtos industriais indicam um ambiente propício para a utilização de novas tecnologias como fator de inovação. Neste trabalho é proposto o uso do Scanner Tridimensional Móvel, aliado a ferramentas computacionais, para captar imagens e dados em 3D. Com o processo de Digitalização Tridimensional obtêm-se, com grande precisão, detalhes de superfícies, texturas e objetos. Esta técnica apresenta-se como uma ferramenta capaz de proporcionar um diferencial para o projeto de bens de consumo, criando novas possibilidades no Design.

  3. Structure and optical properties of GaSe-CdSe composites driven by Cd intercalation in GaSe lamellar crystals

    International Nuclear Information System (INIS)

    Caraman, Iuliana; Kantser, Valeriu; Evtodiev, Igor; Untila, Dumitru; Dmitroglo, Liliana; Leontie, Liviu; Arzumanyan, Grigory

    2015-01-01

    A new composite material composed of GaSe and CdSe has been obtained by treatment of GaSe single-crystal lamellas in Cd vapors at temperatures of 773-853 K and intercalation of Cd interlayers. The structure and optical properties of the GaSe-CdSe composite material have been studied. The content of CdSe crystallites was found to grow with increasing treatment temperature or with increasing duration of treatment at a constant temperature. Analysis of XRD, PL, XPS, AFM, and Raman patterns has shown that the heterogeneous composite composed of micro and nanocrystallites of CdSe in GaSe can be obtained by Cd intercalation in a temperature range of 753-853 K. On the basis of Raman spectrum, the vibrational modes of the composite have been identified. The PL of these materials contains emission bands of free and bound excitons, donor-acceptor bands, and bands of recombination via impurity levels. The PL emission spectra measured at a temperature of 78 and 300 K for the composites result from the overlapping of the emission bands of the components of GaSe doped with Cd and the CdSe crystallites. (authors)

  4. Stable and metastable phases in reciprocal systems PbSe + Ag2I2 Ag2Se + PbI2 and PbSe + CdI2 = CdSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Safronov, E.V.

    2005-01-01

    Mutual system PbSe + Ag 2 I 2 = Ag 2 Se + PbI 2 is investigated. It is shown that diagonal Ag 2 Se-PbI 2 is stable. Liquidus surface and isothermal section at 633 K of phase diagram of PbSe-Ag 2 Se-PbI 2 system are built. Transformations directing to crystallization metastable ternary compound forming in PbSe-PbI 2 system and metastable polytype modifications of lead iodide in PbSe-Ag 2 Se-PbI 2 system at 620-685 K are studied. By hardening from molten state (1150-1220 K) new interstitial metastable phases crystallizing in CdCl 2 structural type are obtained in PbSe-Ag 2 Se-PbI 2 and PbSe + CdI 2 = CdSe + PbI 2 systems [ru

  5. Synthesis and characterization of ZnSe:Fe/ZnSe core/shell nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lin; Zhu, Jianguo, E-mail: yanglin_1028@163.com; Xiao, Dingquan

    2014-04-15

    High-quality ZnSe:Fe/ZnSe core/shell nanocrystals were prepared via a hydrothermal microemulsion technique. Effective surface passivation of monodisperse ZnSe:Fe nanocrystals is achieved by overcoating them with a ZnSe shell. The samples were characterized by means of XRD, EDX, TEM, PSD, XPS, photoluminescence, and Raman spectrum. The results show that the as-synthesized nanocrystals are cubic zinc blende ZnSe structure with high purity and the average particle size of ZnSe:Fe/ZnSe core/shell nanocrystal is larger than that of ZnSe:Fe core. The growth of ZnSe shell causes a small red shift in PL spectra, and then the PL quantum yield (QY) increases from 16% before shell growth to the maximum of 37% after increasing shell thickness up to 1.2 monolayers (ML). Moreover, both transverse optic (TO) and longitudinal optic (LO) phonon modes of ZnSe are shifted toward lower frequency as compared with the reported ones. -- Highlights: • ZnSe:Fe/ZnSe core/shell QDs were prepared by a hydrothermal microemulsion method. • ZnSe shell efficiently passivates surface defects by serving as a physical barrier. • The particle size and PL properties can be turned with the growth of ZnSe shell. • The luminescence efficiency and stability of QDs could be improved in this manner.

  6. Measurement of 76Se and 78Se (γ, n) cross sections

    International Nuclear Information System (INIS)

    Kitatani, Fumito; Harada, Hideo; Goko, Shinji; Utsunomiya, Hiroaki; Akimune, Hidetoshi; Toyokawa, Hiroyuki; Yamada, Kawakatsu

    2011-01-01

    The (γ, n) cross sections of Se isotopes ( 76 Se, 78 Se) were measured to supply fundamental data for estimating the inverse reaction cross section, i.e., the 79 Se(n, γ) 80 Se cross section. The enriched samples and a reference 197 Au sample were irradiated with laser-Compton scattering (LCS) γ-rays. The excitation function of each (γ, n) cross section was determined for the energy range from each near neutron separation energy to the threshold energy of (γ, 2n) reaction. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS γ-rays. Systematic (γ, n) cross sections for Se isotopes including 80 Se were compared with those calculated by using a statistical model calculation code TALYS. (author)

  7. Thermoelectric prospects of chemically deposited PbSe and SnSe thin films

    Science.gov (United States)

    Nair, P. K.; Martínez, Ana Karen; Rosa García Angelmo, Ana; Barrios Salgado, Enue; Nair, M. T. S.

    2018-03-01

    Thin films of PbSe of 400-600 nm in thickness, were obtained via chemical deposition from a solution containing lead nitrate, thiourea and selenosufate. SnSe thin films of 90-180 nm in thickness, were also obtained by chemical deposition from a solution containing selenosulfate. Optical and electrical properties of these thin films were significantly altered by heating them in selenium vapor at 300 °C. Thin film PbSe has a bandgap (Eg) of 1.17 eV (direct gap, forbidden transitions), which decreases to 0.77 eV when it has been heated. Its electrical conductivity (σ) is p-type: 0.18 Ω-1 cm-1 (as-prepared), and 6.4 Ω-1 cm-1 when heated. Thin film SnSe is of orthorhombic crystalline structure which remains stable when heated at 300 °C, but its Eg increases from 1.12 eV (indirect) in as-prepared film to 1.5 eV (direct, forbidden transitions) upon heating. Its electrical conductivity is p-type, which increases from 0.3 Ω-1 cm-1 (as-prepared) to 1 Ω-1 cm-1 when heated (without Se-vapor). When SnSe film is heated at 300 °C in the presence of Se-vapor, they transform to SnSe2, with Eg of 1.5 eV (direct, forbidden) with n-type electrical conductivity, 11 Ω-1 cm-1. The Seebeck coefficient for the PbSe films is: +0.55 mV K-1 (as prepared) and +0.275 mV K-1 (heated); for SnSe films it is: +0.3 mV K-1 (as prepared) and +0.20 mV K-1 (heated); and for SnSe2 film, - 0.35 mV K-1. A five-element PbSe-SnSe2-PbSe-SnSe2-PbSe thermoelectric device demonstrated 50 mV for a temperature difference ΔT = 20 °C (2.5 mV K-1). For SnSe-SnSe2-SnSe-SnSe2-SnSe device, the value is 15 mV for ΔT = 20 °C (0.75 mV K-1). Prospect of these thin films in thermoelectric devices of hybrid materials, in which the coatings may be applied on distinct substrate and geometries is attractive.

  8. Expression and crystallization of SeDsbA, SeDsbL and SeSrgA from Salmonella enterica serovar Typhimurium

    International Nuclear Information System (INIS)

    Jarrott, R.; Shouldice, S. R.; Gunčar, G.; Totsika, M.; Schembri, M. A.; Heras, B.

    2010-01-01

    The cloning, purification, crystallization and preliminary crystallographic studies of three DsbA-like proteins present in S. enterica serovar Typhimurium, SeDsbA, SeDsbL and SeSrgA, are reported. Pathogens require protein-folding enzymes to produce functional virulence determinants. These foldases include the Dsb family of proteins, which catalyze oxidative folding in bacteria. Bacterial disulfide catalytic processes have been well characterized in Escherichia coli K-12 and these mechanisms have been extrapolated to other organisms. However, recent research indicates that the K-12 complement of Dsb proteins is not common to all bacteria. Importantly, many pathogenic bacteria have an extended arsenal of Dsb catalysts that is linked to their virulence. To help to elucidate the process of oxidative folding in pathogens containing a wide repertoire of Dsb proteins, Salmonella enterica serovar Typhimurium has been focused on. This Gram-negative bacterium contains three DsbA proteins: SeDsbA, SeDsbL and SeSrgA. Here, the expression, purification, crystallization and preliminary diffraction analysis of these three proteins are reported. SeDsbA, SeDsbL and SeSrgA crystals diffracted to resolution limits of 1.55, 1.57 and 2.6 Å and belonged to space groups P2 1 , P2 1 2 1 2 and C2, respectively

  9. Estudo do comportamento e da resistencia das vigas mistas aço-concreto constituídas por perfis formados a frios e lajes pré-fabricadas

    OpenAIRE

    Luciano Augusto Figueiredo de Oliveira

    2001-01-01

    O presente trabalho tem como objetivo apresentar os resultados da pesquisa teórico-experimental, realizada no Laboratório de Análise Experimental de Estruturas, do Departamento Engenharia de Estruturas da Escola de Engenharia/UFMG, sobre o comportamento e a resistência de vigas mistas aço-concreto empregando-se perfis metálicos formados a frio e pré-lajes de concreto armado, visando sua aplicação nos sistemas construtivos para edificações residenciais de 04 pavimentos. Para possibilitar a aná...

  10. O humano desumanizado num mundo sem sentido: Samuel Beckett e o herói absurdo = The dehumanized human being in a nonsense world: Samuel Beckett and the absurd hero

    OpenAIRE

    Maristela Kirst de Lima Girola

    2011-01-01

    Este ensaio tem como objetivo discutir a construção das personagens emEsperando Godot, de Samuel Beckett, apoiando-se nos estudos de Martin Esslin sobre o Teatro do Absurdo, uma forma de drama que enfatiza o absurdo da existência humana, empregando fragmentação, repetição e ininteligibilidade, como reação artística à Segunda Guerra Mundial.This essay discusses the construction of the characters in Waiting for Godot by Samuel Beckett, based on Martin Esslin’s studies on the Theatre of the Absu...

  11. O humano desumanizado num mundo sem sentido: Samuel Beckett e o herói absurdo - doi: 10.4025/actascilangcult.v33i1.6485

    OpenAIRE

    Girola, Maristela Kirst de Lima; PUCRS

    2011-01-01

    Este ensaio tem como objetivo discutir a construção das personagens em Esperando Godot, de Samuel Beckett, apoiando-se nos estudos de Martin Esslin sobre o Teatro do Absurdo, uma forma de drama que enfatiza o absurdo da existência humana, empregando fragmentação, repetição e ininteligibilidade, como reação artística à Segunda Guerra Mundial. This essay discusses the construction of the characters in Waiting for Godot by Samuel Beckett, based on Martin Esslin’s studies on the Theatre of the...

  12. Avaliação da capacidade de tratamento do processo LFT

    OpenAIRE

    Martins, Tânia Filipa Antunes

    2010-01-01

    Tendo em vista a reutilização de águas residuais industriais, foi desenvolvida uma tecnologia denominada Liquid Filtration Technology destinada a desinfectar e filtrar um efluente passível de reutilização. As variáveis de processo consideradas no que concerne a este trabalho, basearam-se em parâmetros de qualidade da água e estudos de viabilidade económica. Para o efeito o equipamento foi instalado em dois locais distintos, em termos de características do efluente e relativamente ao tipo d...

  13. O Trabalho e o labirinto da responsabilidade socioempresarial:a experiência da cidadania empresarial do Banco do Brasil

    OpenAIRE

    Ponte, Júlio Ramon Teles da

    2011-01-01

    Na crise sistêmica contemporânea, a política econômica é direcionada para corrigir as consequências do funcionamento deste metabolismo, porém dentro dos limites do capital. Nessa perspectiva, os tomadores de decisão propõem políticas comerciais, agrícolas e industriais a fim de garantir condições para o crescimento econômico. Todavia, tal como numa rua sem saída, constata-se a insuficiência do Estado em conferir efetividade para o funcionamento de todos os segmentos da economia, sobretudo, em...

  14. Desenvolvimento de novas tecnologias para produção de xarope de glicose a partir do amido

    OpenAIRE

    Freitas, Aline Costa de [UNESP

    2012-01-01

    As amilases são enzimas que catalisam a hidrólise do amido, dentre as quais se destaca a α-amilase, a β-amilase e a glicoamilase. Apresentam grande importância biotecnológica devido sua aplicação em vários processos industriais, principalmente alimentício. Podem ser obtidas de plantas, animais e microorganismos, no entanto, enzimas microbianas encontram maior demanda industrial. Além da importância econômica destas enzimas, novas metodologias têm sido desenvolvidas com resíduos como substrato...

  15. Processos de Aprendizagem e Inovação em Setores Tradicionais: Os Arranjos Produtivos Locais de Confecções no Brasil

    OpenAIRE

    José Eduardo Cassiolato; Renato Ramos Campos; Fabio Stallivieri

    2007-01-01

    O estudo analisa as condições dos processos de aprendizagem tecnológica em setores industriais tradicionais enfatizando os esforços internos das empresas, a utilizações das fontes de informação externas a elas, e as características das inovações resultantes destes processos. Destaca-se a dimensão local dos processos de aprendizagem no âmbito de arranjos produtivos locais, considerando a natureza sistêmica e interativa desses processos. Além do recorte setorial abordando as especificidades do ...

  16. Soroprevalência e fatores de risco para sífilis em população carcerária de Goiás

    OpenAIRE

    Andrade,Ana Lúcia Sampaio Sgambatti de; Martelli,Celina Maria Turchi; Sousa,Luiz Carlos Silva; Sousa,Marta Antunes de; Zicker,Fabio

    1989-01-01

    Com o objetivo de dimensionar a prevalência da infecção pelo Treponema pallidum e determinar fatores de risco relacionados a soropositividade foram rastreados 299 presidiários no Centro Penitenciário de Atividades Industriais de Goiás (CEPAI-GO), 20 Km de Goiânia. O rastreamento sorológico foi realizado utilizando-se como critério de positividade, qualquer resultado sororeagente ao VDRL independentemente do título. Através de um questionário padronizado foram avaliados os seguintes fatores de...

  17. Comparação dos modelos de avaliação de empresas com base no fluxo de caixa descontado e no lucro residual: estudo de caso de uma empresa de energia elétrica.

    Directory of Open Access Journals (Sweden)

    Valter Saurin

    2009-02-01

    Full Text Available Na metodologia de avaliação de empresas destacam-se como clássicos os modelos baseados no fluxo de caixa descontado e no lucro residual. Cada modelo tem suas características e fornece uma informação diferenciada, mas teoricamente devem proporcionar resultados financeiros equivalentes, se for empregada à mesma base de dados. O objetivo deste estudo é verificar se, com a utilização da mesma base de dados, os modelos do fluxo de caixa, descontado e do lucro residual, proporcionamresultados equivalentes ou se existem conflitos metodológicos entre eles. Efetuou-se a análise de um caso real, de uma empresa de utilidade pública,empregando-se o modelo do fluxo de caixa descontado e do lucro residual comparando-se os resultados com o preço negociado, ajustado para representar 100% do capital próprio. Os resultados mostraram diferenças significativas entre os valores calculados e entre estes e o preço de venda da empresa em estudo.

  18. CuInSe2 nano-crystallite reaction kinetics using solid state reaction from Cu2Se and In2Se3 powders

    International Nuclear Information System (INIS)

    Hsiang, Hsing-I; Lu, Li-Hsin; Chang, Yu-Lun; Ray, Dahtong; Yen, Fu-Su

    2011-01-01

    Highlights: → CuInSe 2 phase increased gradually accompanied with a decrease in γ-In 2 Se 3 and no intermediate phase during calcination. → CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a one-dimensional diffusion-controlled reaction with apparent activation energy of about 122.5 kJ/mol. → The solid reaction kinetics may be dominated by the diffusion of In 3+ ions. - Abstract: The reaction mechanism and CuInSe 2 formation kinetics using a solid state reaction from Cu 2 Se and In 2 Se 3 powders synthesized using a heating up process were investigated using X-ray diffractomy (XRD) and transmission electron microscopy (TEM). It was observed that the CuInSe 2 phase increased gradually, accompanied with a decrease in γ-In 2 Se 3 with no intermediate phase as the calcination temperature and soaking time were increased. The reaction kinetics was analyzed using the Avrami and polynomial kinetic model, suggesting that CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a diffusion-controlled reaction with an apparent activation energy of about 122.5-182.3 kJ/mol. Cu 2 Se and In 2 Se 3 phases react and directly transform into CIS without the occurrence of any intermediate phase and the size of the newly formed CuInSe 2 crystallites was close to that of the Cu 2 Se reactant particle based on the TEM results, which indicated that the solid reaction kinetics may be dominated by the diffusion of In 3+ ions.

  19. Fatores influenciadores do sucesso da adoção da produção enxuta: uma análise da indústria de três países de economia emergente

    Directory of Open Access Journals (Sweden)

    Daniel A. Glaser-Segura

    2011-12-01

    Full Text Available A cultura organizacional tem sido apontada como um fator importante na obtenção de sucesso de sistemas de produção enxuta. Como as empresas são influenciadas pela cultura dos países onde estão localizadas, é possível que ocorram vantagens comparativas determinadas pela localização, quando a cultura nacional se ajustar melhor à filosofia lean. Neste artigo, apresentam-se os resultados de uma pesquisa do tipo survey, realizada com gerentes industriais de 248 empresas de Argentina, Brasil e Romênia, na qual foram investigados aspectos culturais com potencial influência sobre o grau de sucesso da implantação de sistemas de produção enxuta. Entre outras constatações, descobriu-se uma tímida adoção dos padrões.

  20. Controllable size reduction of CdSe nanowires through the intermediate formation of Se-coated CdSe nanowires using acid and thermal treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lam, N S [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Wong, K W [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Li, Q [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Zheng, Z [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Lau, W M [Surface Science Western, University of Western Ontario, London, ON, N6A 5B7 (Canada)

    2007-10-17

    Thinning of CdSe nanowires (NWs) with controllable size was achieved by a simple acid treatment and subsequent annealing on thick CdSe NWs synthesized from vapour phase growth. During acid treatment, not only the undesired impurities such as native oxides of Cd and Se could be etched, but surface reactions of CdSe NWs were also observed, resulting in the formation of a layer of elemental Se around a thinner CdSe core. As a result, a heterostructure of Se - CdSe nanostructure formed after acid treatment of CdSe NWs. Upon thermal annealing, the Se shell was effectively removed and thinned stoichiometric single-crystalline CdSe NWs could be obtained. It was observed that NWs could be thinned by up to {approx}60% in diameter by acid treatment and subsequent Se thermal desorption. The degree of thinning was controllable by adjusting the duration of acid treatment. The success of the thinning of CdSe NWs by simple acid treatment and the annealing process reported here opens a new processing route for obtaining stoichiometric CdSe NWs with controllable size reduction and improved aspect ratio. This can undoubtedly broadly improve the range of applications of 1D CdSe nanostructures and allow more exploration of their uni-directional properties. A correction was made to the last paragraph of section 3 on 18 September 2007. The corrected electronic version is identical to the print version.

  1. Controllable size reduction of CdSe nanowires through the intermediate formation of Se-coated CdSe nanowires using acid and thermal treatment

    International Nuclear Information System (INIS)

    Lam, N S; Wong, K W; Li, Q; Zheng, Z; Lau, W M

    2007-01-01

    Thinning of CdSe nanowires (NWs) with controllable size was achieved by a simple acid treatment and subsequent annealing on thick CdSe NWs synthesized from vapour phase growth. During acid treatment, not only the undesired impurities such as native oxides of Cd and Se could be etched, but surface reactions of CdSe NWs were also observed, resulting in the formation of a layer of elemental Se around a thinner CdSe core. As a result, a heterostructure of Se - CdSe nanostructure formed after acid treatment of CdSe NWs. Upon thermal annealing, the Se shell was effectively removed and thinned stoichiometric single-crystalline CdSe NWs could be obtained. It was observed that NWs could be thinned by up to ∼60% in diameter by acid treatment and subsequent Se thermal desorption. The degree of thinning was controllable by adjusting the duration of acid treatment. The success of the thinning of CdSe NWs by simple acid treatment and the annealing process reported here opens a new processing route for obtaining stoichiometric CdSe NWs with controllable size reduction and improved aspect ratio. This can undoubtedly broadly improve the range of applications of 1D CdSe nanostructures and allow more exploration of their uni-directional properties. A correction was made to the last paragraph of section 3 on 18 September 2007. The corrected electronic version is identical to the print version

  2. Benefits of oxygen in CuInSe{sub 2} and CuGaSe{sub 2} containing Se-rich grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Chunbao, E-mail: chunbaofeng@126.com [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Luo, Min; Li, Bolin; Li, Dengfeng [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Nie, Jinlan [Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Dong, Huining [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China)

    2014-05-01

    Using density functional theory calculation, we show that oxygen (O) exhibits an interesting effect in CuInSe{sub 2} and CuGaSe{sub 2}. The Se atoms with dangling bonds in a Se-rich Σ3 (114) grain boundary (GB) create deep gap states due to strong interaction between Se atoms. However, when such a Se atom is substituted by an O atom, the deep gap states can be shifted into valence band, making the site no longer a harmful non-radiative recombination center. We find that O atoms prefer energetically to substitute these Se atoms and induce significant lattice relaxation due to their smaller atomic size and stronger electronegativity, which effectively reduces the anion–anion interaction. Consequently, the deep gap states are shifted to lower energy regions close or even below the top of the valence band.

  3. Alternative syntheses of [73,75Se]selenoethers exemplified for homocysteine[73,75Se]selenolactone

    International Nuclear Information System (INIS)

    Ermert, J.; Blum, T.; Hamacher, K.; Coenen, H.H.

    2001-01-01

    The present work describes two radiosynthetic pathways to prepare homocysteine[ 75 Se]selenolactone 1 starting from n.c.a. [ 75 Se]selenite 2. It was achieved either by alkylation reaction of n.c.a. methyl[ 75 Se]selenide 4 or by hydrolysis of alkylated 1,3-dicyclohexyl[ 75 Se]selenourea 11. N.c.a. methyl[ 75 Se]selenide 4 is available using sulfur as non-isotopic carrier. However, the radiochemical yield of the substitution of 2-tert.-butoxycarbonylamino-4-bromobutyric acid ethylester 5 with n.c.a. methyl-[ 75 Se]selenide is only in the range of 15%-20%. Birch reduction of protected n.c.a. [ 75 Se]selenomethionine 6 formed leads to a RCY of 5%-10% homocysteine[ 75 Se]selenolactone 1. Alternatively, the synthesis of homocysteine[ 75 Se]selenolactone 1 is possible by hydrolysis of the corresponding [ 75 Se]selenouronium salt 11 available by addition of 2-tert.-butoxycarbonylamino-4-bromobutyric acid ethylester 5 to 1,3-dicyclohexyl[ 75 Se]selenourea 10. A method was developed for the synthesis of 1,3-dicyclohexyl[ 75 Se]selenourea 10 by addition of c.a. [ 75 Se]SeH 2 to 1,3-dicyclohexylcarbodiimide, which leads to 20%-30% RCY of c.a. homocysteine[ 75 Se]selenolactone 1. (orig.)

  4. The determination of Se content in Se egg by NAA in MNSR

    International Nuclear Information System (INIS)

    Wang Ke; Hou Xiaolin

    1994-01-01

    The selenium contents in the yolk, albumin and shell of the egg which was laid by layer hen fed with various Se concentrations are determined by thermal neutron activation analysis with a nuclear reaction 78 Se(n, γ) 77 Se m on the miniature neutron source reactor (MNSR). The results show that the more the selenium added to the feed, the higher the Se content in the egg and that in the egg constituents, the highest Se content is in the egg yolk and the lowest in the egg albumin

  5. ANÁLISE DO PROCESSO INCLUSIVO EM UMA ESCOLA ESTADUAL NO MUNICÍPIO DE BAURU: A VOZ DE UM ALUNO COM DEFICIÊNCIA VISUAL

    Directory of Open Access Journals (Sweden)

    Eliza Oliveira Lippe

    Full Text Available A proposta de educação inclusiva do governo estadual de São Paulo baseia-se na adaptação curricular. O presente estudo teve por ob jetivo analisar a voz do aluno com deficiência visual incluído na sala de aula regular. Utilizou-se, para análise dos dados, a Análise Textual Discursiva. Os resultados obtidos demonstraram que o aluno com defi ciência visual está apenas inserido na sala de aula regular, e as políticas públicas pouco se atentam para a sua inclusão. Nesse sentido, observa mos a necessidade de uma formação continuada dos professores da sala regular, não apenas para adequar suas metodologias, mas também para que eles se preocupem em dialogar com os professores especialistas, empregando as salas de recursos como um espaço de apoio.

  6. Luminescence spectra of CdSe/ZnSe double layers of quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Reznitsky, Alexander; Permogorov, Sergei; Korenev, Vladimir V.; Sedova, Irina; Sorokin, Sergey; Sitnikova, Alla; Ivanov, Sergei [A.F. Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, 194021 St. Petersburg (Russian Federation); Klochikhin, Albert [B.P. Konstantinov Nuclear Physics Institute, St. Petersburg (Russian Federation)

    2009-12-15

    We have studied the emission spectra and structural properties of double CdSe/ZnSe quantum dot (QD) sheet structures grown by molecular beam epitaxy in order to elucidate the mechanisms of the electronic and strain field interaction between the QD planes. The thickness of the ZnSe barrier separating the CdSe sheets was in the range of 10-60 monolayers (ML) in the set of samples studied. We have found that coupling between dots in adjacent layers becomes relatively strong in CdSe/ZnSe double layers structures with 25-27 ML barrier, while it is rather weak when the barrier thickness exceeds 30 ML. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Hopping conduction in gamma-irradiated InSe and InSe:Sn single crystals

    International Nuclear Information System (INIS)

    MUSTAFAEVA, S.N.; ISMAILOV, A.A.; ASADOV, M.M.

    2010-01-01

    Full text : The semiconductive InSe layer compound is characterized by a strong covalent bond inside the layers and a weak Van der Waals bonding between them. It was shown that across the layers of InSe single crystals at low temperatures (T ≤ 200 K) at direct current (dc) hopping conduction through localized states near the Fermi level takes place. The results of dc-conductivity of gamma-irradiated p-InSe and n-InSe : Sn layer single crystals have been presented in this work. ρ-InSe single crystal specimens grown by the Bridgman method were used in the experiments. Plates of the crystals under study were obtained by cleaving along the layers of single crystal ingots. The single-crystal InSe samples for electric measurements had the form of planar capacitors normal to the C axis of the crystals, with silver-paste electrodes. The thickness of the InSe samples was 300 mkm. Co 60 serves as the source of irradiation with energy of gamma-quantum equal to 1.3 MeV. The electric properties of non-irradiated and gamma-irradiated InSe crystals were measured under the same conditions. It is revealed that InSe and InSe : Sn (0.2 and 0.4 mole percent Sn) single crystals exhibit a variable range hopping conduction along a normal to their natural layers at temperatures T≤200 K in a dc electric field. From experimental data the parameters of localized states of p-InSe and n-InSe : Sn were calculated before and after gamma-irradiation. It is revealed that gamma-irradiation of p-InSe and n-InSe : Sn (0.2 and 0.4 mole percent Sn) single crystals leads to significant change of localized states parameters. After gamma-irradiation the density of states near the Fermi level increased, but their energy spread and the average jump distance decreased. The concentrations of radiated defects were estimated in p-InSe (5.18*10 1 7 sm - 3) and n-InSe : Sn (2.5*10 1 7 - 2.7*10 1 8 sm - 3) single crystals. The present results demonstrate that gamma-irradiation offers the possibility of tuning

  8. Structure of Se-rich As-Se glasses by high-resolution x-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Golovchak, R.; Kovalskiy, A.; Miller, A. C.; Jain, H.; Shpotyuk, O.

    2007-01-01

    To establish the validity of various proposed structural models, we have investigated the structure of the binary As x Se 100-x chalcogenide glass family (x≤40) by high-resolution x-ray photoelectron spectroscopy. From the composition dependence of the valence band, the contributions to the density of states from the 4p lone pair electrons of Se and the 4p bonding states and 4s electrons of Se and As are identified in the top part of the band. The analysis of Se 3d and As 3d core-level spectra supports the so-called chain crossing model for the atomic structure of Se-rich As x Se 100-x bulk glasses. The results also indicate small deviations (∼3-8%) from this model, especially for glass compositions with short Se chains (25 40 Se 60 and of Se-Se-Se fragments in a glass with composition x=30 is established

  9. Phase diagram of SnTe-CdSe cross-section of SnTe+CdSe reversible SnSe+CdTe ternary reciprocal system

    International Nuclear Information System (INIS)

    Dubrovin, I.V.; Budennaya, L.D.; Mizetskaya, I.B.; Sharkina, Eh.V.

    1986-01-01

    Phase equilibrium diagram of SnTe-CdSe cross-section of Sn, Cd long Te, Se ternary reciprocal system is investigated using the methods of differential thermal, X-ray phase, and microstructural analyses. Maximum length of solid solutions on the base of SnTe corresponds to approximately 14 mol.% at 1050 K and approximately 3 mol.% of CdSe at 670 K. Region of solid solutions on the base of CdSe corresponds to less than 1 mol.% of SnTe at room temperature. SnTe-CdSe cross-section is not a quasibinar one. Equilibrium is shifted to the left in the SnTe+CdSe reversible SnSe+CdTe reciprocal system

  10. Resíduo agroindustrial na formação de mudas ornamentais irrigadas com água residuária

    Directory of Open Access Journals (Sweden)

    Aline Costa Ferreira

    2014-06-01

    Full Text Available O reuso de água de esgoto tratada juntamente com o uso de resíduos industriais para a formação de mudas de girassol ornamental vem sendo uma alternativa econômica para o estado da Paraíba. Nesse contexto, a pesquisa foi realizada objetivando-se a utilização de resíduo agroindustrial na formação de mudas ornamentais irrigadas com água residuária. Desenvolvido em ambiente protegido na Universidade Federal de Campina Grande – UFCG, localizado no Estado da Paraíba-PB, utilizaram-se os seguintes tratamentos: 100% substrato comercial (SC, 100% solo (S, 100% fibra de coco (FC e 50% (SC misturado a 50% (FC, combinados com 2 tipos de água (A1 – abastecimento; A2 – residuária. O delineamento experimental foi em blocos ao acaso, num esquema fatorial de 4 x 2, com 3 repetições e 3 plantas por repetição. Foram avaliados a altura de planta (AP, o número de folhas (NF e o diâmetro do caule (DC, comprimento radicular (CR, fitomassa fresca da parte aérea (FFPA e da raiz (FFR, fitomassa seca da parte aérea (FSPA e da raiz (FSR.  As maiores médias foram relacionadas à utilização de água residuária e resultados obtidos pelo uso dos diversos substratos, os quais tiveram significância para algumas variáveis, em pelo menos uma época de avaliação. Percebe-se a importância do uso de água residuária como fertirrigação das mudas e o reaproveitamento de resíduos industriais como substrato, sendo uma alternativa com grande potencial e viável para os pequenos agricultores.

  11. La lectura en el aula. Qué se hace, qué se debe hacer y qué se puede hacer

    OpenAIRE

    Pablo Lorente Muñoz

    2011-01-01

    Emilio Sánchez Miguel (Coord.). La lectura en el aula. Qué se hace, qué se debe hacer y qué se puede hacer. Graó, col. Crítica y Fundamentos, 27. Barcelona, 2010. 382 págs. ISBN: 978-84-7827-892-3

  12. SE-VYZ

    International Nuclear Information System (INIS)

    Anon

    2004-01-01

    On this CD compact disc 6 video-films (A-1 NPP; Bituminization; Cementation; Pressing; The Interim spent fuel storage facility; Transport into the National radioactive waste repository Mochovce; Ignition; and Vitrification). In these films process of radioactive waste treatment in the Bohunice Radioactive Waste Processing Center (SE-VYZ) is presented. 2 presentations about radioactive wastes treatment in the SE-VYZ are included

  13. Speciation of Se and DOC in soil solution and their relation to Se bioavailability.

    Science.gov (United States)

    Weng, Liping; Vega, Flora Alonso; Supriatin, Supriatin; Bussink, Wim; Van Riemsdijk, Willem H

    2011-01-01

    A 0.01 M CaCl(2) extraction is often used to asses the bioavailability of plant nutrients in soils. However, almost no correlation was found between selenium (Se) in the soil extraction and Se content in grass. The recently developed anion Donnan membrane technique was used to analyze chemical speciation of Se in the 0.01 M CaCl(2) extractions of grassland soils and fractionation of DOC (dissolved organic carbon). The results show that most of Se (67-86%) in the extractions (15 samples) are colloidal-sized Se. Only 13-34% of extractable Se are selenate, selenite and small organic Se (<1 nm). Colloidal Se is, most likely, Se bound to or incorporated in colloidal-sized organic matter. The dominant form of small Se compounds (selenate, selenite/small organic compounds) depends on soil. A total of 47-85% of DOC is colloidal-sized and 15-53% are small organic molecules (<1 nm). In combination with soluble S (sulfur) and/or P (phosphor), concentration of small DOC can explain most of the variability of Se content in grass. The results indicate that mineralization of organic Se is the most important factor that controls Se availability in soils. Competition with sulfate and phosphate needs to be taken into account. Further research is needed to verify if concentration of small DOC is a good indicator of mineralization of soil organic matter.

  14. One-pot synthesis of hollow NiSe-CoSe nanoparticles with improved performance for hybrid supercapacitors

    Science.gov (United States)

    Chen, Haichao; Fan, Meiqiang; Li, Chao; Tian, Guanglei; Lv, Chunju; Chen, Da; Shu, Kangying; Jiang, Jianjun

    2016-10-01

    Hollow NiSe-CoSe samples have been synthesized for the first time via a one-pot solvothermal approach. The strategy is robust enough to synthesize NiSe-CoSe nanoparticles with different NiSe to CoSe ratios but with a similar hollow structure. Co ions in the NiSe-CoSe nanoparticles play decisive role for formation of the hollow structure; otherwise, the nanoparticles become solid for the NiSe sample. When used as the positive electroactive materials for energy storage, the NiSe-CoSe samples show excellent electrochemical activity in alkaline electrolyte. Using the synergistic effect between NiSe and CoSe, the electrochemical performance of NiSe-CoSe can be tuned by varying the NiSe to CoSe ratios. The NiSe-CoSe sample with a NiSe to CoSe ratio of 4:2 shows the best electrochemical performance in terms of superior specific capacity, improved rate capability and excellent cycling stability. In addition, the electrochemical performance of NiSe-CoSe sample with a NiSe to CoSe ratio of 4:2 is also evaluated via assembling hybrid supercapacitors with RGO, and the hybrid supercapacitor delivers both high power and energy densities (41.8 Wh kg-1 at 750 W kg-1 and 20.3 Wh kg-1 at 30 kW kg-1).

  15. Excitons, biexcitons, and phonons in ultrathin CdSe/ZnSe quantum structures

    DEFF Research Database (Denmark)

    Gindele, F.; Woggon, Ulrike; Langbein, Wolfgang Werner

    1999-01-01

    The optical properties of CdSe nanostructures grown by migration-enhanced epitaxy of CdSe on ZnSe are studied by time-, energy-, and temperature-dependent photoluminescence and excitation spectroscopy, as well as by polarization-dependent four-wave mixing and two-photon absorption experiments...

  16. Acceptability of sweetened and low calorie dairy desserts: affective tests and internal preference mapping

    OpenAIRE

    Oliveira, Ana Paula Vital de; Frasson, Karina; Almeida, Tereza Cristina Avancini de; Benassi, Marta de Toledo

    2004-01-01

    A aceitação de sobremesas lácteas de chocolate (três pudins com açúcar, cinco pudins dietéticos e dois flans comerciais) foi avaliada por 56 consumidores utilizando delineamento de blocos completos balanceados e empregando-se uma escala hedônica estruturada de nove pontos. Os provadores foram caracterizados através de um questionário para coleta de informações pessoais e hábitos de consumo de produtos dietéticos e pudins. Os dados de aceitação foram analisados por ANOVA e teste de médias. Emp...

  17. Desenvolvimento e validação de metodologias analíticas para quantificação de β-escina em extratos de Aesculus hippocastanum L. (Castanha da Índia)

    OpenAIRE

    Dutra, Lidiane Silva

    2012-01-01

    Todos os povos do mundo fazem uso de plantas medicinais ou de seus derivados, para o tratamento de doenças. Os fitoterápicos são medicamentos obtidos empregando-se, como princípio ativo, exclusivamente matérias-primas vegetais e são caracterizados pelo conhecimento da eficácia e dos riscos de seu uso. No Brasil estes produtos são regulamentados pela Agência Nacional de Vigilância Sanitária (ANVISA) e devem apresentar qualidade, segurança e eficácia. A β-escina é o principal princípio ativo da...

  18. Remoção de compostos orgânicos causadores de gosto e odor em águas de abastecimento em sistemas pós-filtros adsorvedores de carvão ativado granular.

    OpenAIRE

    Carolina Alves de Souza Ferreira

    2009-01-01

    O objetivo desta pesquisa foi o de estudar o desempenho de pós-filtros adsorvedores de carvão ativado granular de origem mineral e de origem vegetal, com relação a, principalmente, remoção de 2-metilisoborneol e trans-1,10-dimetiltrans- 9-decalol. Os ensaios experimentais foram conduzidos na estação de tratamento de água Alto da Boa Vista, empregando-se quatro filtros piloto em acrílico com diâmetro interno de 14,2 cm e 1,5 m de profundidade de meio filtrante cada, sendo dois deles preenchido...

  19. Estudo eletroquímico e termoanalítico dos sistemas Ir/Hg e Pt - (30%) Ir/Hg

    OpenAIRE

    Milaré, Edilson [UNESP

    2004-01-01

    Eletrodos laminares de Ir ou Pt-Ir(30%) foram empregados como substratos para deposição eletroquímica de Hg, a partir de soluções contendo íons Hg(I), e remoção deste Hg por meio de voltametria cíclica (VC) ou térmica (termogravimetria / termogravimetria derivada - TG/DTG e calorimetria exploratória diferencial - DSC). A superfície dos eletrodos foi caracterizada empregando-se as técnicas complementares de análise: microscopia eletrônica de varredura (imagens SEM, microanálise por EDX e mapas...

  20. Variabilidade espacial e disponibilidade de cobre e zinco em solos de vinhedos e adjacências

    OpenAIRE

    Valladares,Gustavo Souza; Azevedo,Emílio Carlos de; Camargo,Otávio Antônio de; Grego,Célia Regina; Rastoldo,Alessandra Maria Cia Silva

    2009-01-01

    Com o tempo, o uso agrícola pode levar à contaminação do solo por metais pesados, principalmente por se servir de insumos e agroquímicos que possuem cobre e zinco em sua composição. O objetivo deste trabalho foi determinar os teores de cobre e zinco disponíveis no solo extraídos com DTPA e avaliar sua distribuição espacial empregando a geoestatística em áreas de vinhedos comerciais e experimentais e sob outros usos e coberturas nas adjacências das plantações. Foram coletadas amostras de terra...

  1. Resolução cinética de haloidrinas racêmicas com a lipase B de Candida antarctica e biotransformação de produtos naturais por micro-organismos

    OpenAIRE

    Mariana Provedel Martins

    2012-01-01

    Neste trabalho foram realizadas as resoluções cinéticas das haloidrinas racêmicas (RS)-1-benziloxi-3-cloropropan-2-ol (4a), (RS)-1-benziloxi-3-bromopropan-2-ol (4b), (RS)-1-cloro-3-(4-metoxifenoxi)propan-2-ol (5a), (RS)-1-bromo-3-(4-metoxifenoxi)propan-2-ol (5b), (RS)-1-aliloxi-3-cloro-propan-2-ol (6a) e (RS)-1-aliloxi-3-bromo-propan-2-ol (6b) empregando-se a lipase comercial de Candida antarctica CALB como catalisador e acetato de vinila como agente acilante. As razões enantioméricas das res...

  2. Biodegradação de deoxinivalenol por aspergillus oryzae e rhizopus sp.: um estudo bioquímico de degradação e toxicidade

    OpenAIRE

    Buffon, Jaqueline Garda

    2008-01-01

    A contaminação aleatória de alimentos por micotoxinas afeta as condições de sanidade das dietas de humanos e animais. Dentre as toxinas fúngicas, deoxinivalenol (DON) se destaca pela freqüente contaminação de produtos agrícolas e alimentos e pela sua resistência a degradação pelo emprego de métodos tradicionais de processamento, o que motiva políticas de controle e a busca por técnicas de descontaminação. A descontaminação biológica empregando processsos fermentativos tem sido ...

  3. Cerveja artesanal com pimenta rosa: processamento, características físico-químicas e estudo de mercado.

    OpenAIRE

    GAMBA, M. M.

    2016-01-01

    O consumo de cervejas artesanais, bebidas destinadas a atender paladares mais exigentes, está em expansão no Brasil. Entretanto, pesquisas sobre inovação no ramo cervejeiro são escassas. O objetivo deste estudo foi produzir uma cerveja artesanal do tipo American Pale Ale empregando a pimenta rosa na sua elaboração e avaliar os efeitos da adição desta especiaria no processo fermentativo, bem como no produto final, por meio de análises físico-químicas e microbiológica. Além disso, teve-se como ...

  4. A técnica de Kato para o diagnóstico coprológico de infecções parasitárias

    Directory of Open Access Journals (Sweden)

    Jairo Gonçalves Molina

    1971-02-01

    Full Text Available Empregando-se 76 espécimenis de fezes examinados velo método de Kato modificiado por Martin e Beaver (4, fêz-se a comparação com a técnica da sedimentação pelo método de Hoffman, Pons e Janer. Excetuando o diagnóstico das infecções pelo T. trichurus, nas quais houve evidentes vantagens do método de Kato, não se pode confirmar a superioridade do método de Kato, pelo menos nas condições do laboratório clínico normal. O autor frisa porém, que por falta de espécimens adequados não foi possível testar o método nas infecções pelo S. mansoni, campo que se ressente da falta de técnicas adequadas para o diagnóstico de infecções discretas e no qual se antecipam maiores virtudes do método de Kato.

  5. Avaliação da estabilidade da emulsão óleo/água proveniente dos resíduos de uma indústria beneficiadora de gemas frente ao uso de diferentes surfactantes

    OpenAIRE

    Simone Stülp; Max Alan Ritter; Fernanda Cristina Wiedusch Sindelar

    2013-01-01

    A reutilização dos resíduos gerados pelos diversos setores industriais é uma prática que cada dia é mais utilizado, devido ao comprometimento das indústrias com sua responsabilidade social (proteção ao ambiente) ou a exigências dos órgãos de proteção ambiental, já que muitos resíduos não possuem o devido descarte. Na indústria de beneficiamento de gemas a busca pelo reaproveitamento dos resíduos também tem se tornado uma realidade. O presente trabalho tem como objetivo avaliar o reaproveitame...

  6. Utilização de resinas de troca-iônica em efluentes de galvanoplastia.

    OpenAIRE

    Josiane Costa Riani

    2008-01-01

    A crescente industrialização acompanhada do uso de metais pesados nos processos industriais nas últimas décadas resultou num aumento da contaminação do meio ambiente, principalmente em ambientes aquáticos. Assim, sendo a água um recurso natural de suma importância para a vida, métodos de tratamento de efluentes tornam-se indispensáveis para empresas geradoras de efluentes. O objetivo desse trabalho é a utilização de um sistema de troca iônica constituído por micro-colunas de resinas catiônica...

  7. Nível de Serviço Logístico, Estrutura Organizacional da Logística e Desempenho Empresarial: Associações e Contingenciadores

    OpenAIRE

    Vinicius de Souza Silva Oliveira, Marcus

    2005-01-01

    Atividades logísticas de grandes empresas industriais brasileiras é tema pouco explorado em pesquisas empíricas. Esta dissertação se propõe a analisar possíveis associações entre nível de serviço logístico, estrutura organizacional da logística e o desempenho empresarial das maiores indústrias do Brasil, bem como a influência de variáveis moderadoras (tipo de produto, controle de capital e tamanho da empresa) nas mencionadas associações. Para tal, são utilizados questionários respondidos por ...

  8. Segurança e produção: um modelo para o planejamento e controle integrado

    OpenAIRE

    Saurin,Tarcisio A.; Formoso,Carlos T.; Guimarães,Lia B. M.

    2002-01-01

    Este artigo apresenta um modelo de planejamento e controle da segurança no trabalho (PCS) integrado ao processo de planejamento e controle da produção (PCP). O modelo foi desenvolvido por meio de dois estudos empíricos em obras industriais, adotando-se a pesquisa ação como estratégia de pesquisa. Os requisitos de segurança são integrados ao PCP em três níveis hierárquicos deste processo. No nível de longo prazo, o planejamento da segurança é configurado pelo desenvolvimento de análises prelim...

  9. AdsorÃÃo de Ãons MetÃlicos de Efluente Aquoso Usando BagaÃo do PedÃnculo de Caju: Estudo de Batelada e Coluna de Leito Fixo.

    OpenAIRE

    Sarah de Abreu Moreira AraÃjo

    2008-01-01

    O uso de resÃduos agroindustriais puros ou modificados quimicamente para a remoÃÃo de metais em efluentes industriais aparece como uma alternativa promissora Ãs tecnologias existentes. Os agroresÃduos sÃo bastante estudados devido à sua abundÃncia, baixo custo, biodegradabilidade e a nÃo formaÃÃo de lodo. Neste trabalho utilizou-se o bagaÃo do pedÃnculo de caju (Anarcadium occidentale L.) como adsorvente para remoÃÃo de metais pesados de soluÃÃo aquosa e de efluente produzido por uma indÃstri...

  10. Processo de secagem da goma de cajueiro (Anacardium occidentale L.) e suas propriedades tecnolÃgicas.

    OpenAIRE

    Valeria Melo de Souza

    2011-01-01

    PaÃses tropicais, como o Brasil, sÃo depositÃrios de uma grande variedade de fontes de polissacarÃdeos vegetais conhecidos e outros ainda nÃo explorados que possuem grande potencial em aplicaÃÃes industriais. A goma de cajueiro pode ser citada como um desses polissacarÃdeos. Algumas pesquisas reportam a possibilidade do uso da goma de cajueiro em vÃrios setores e por sua semelhanÃa estrutural com a goma arÃbica, tem sido sugerida como substituta. Sendo assim, este projeto se propÃe a ...

  11. Construção de um armazém industrial e acompanhamento das diferentes fases de obra

    OpenAIRE

    Monteiro, Rui Pedro da Silva

    2016-01-01

    O presente relatório foi elaborado no âmbito da disciplina dissertação/projeto/estágio (DIPRE) que se enquadra no plano de estudos do 2º ano do Mestrado em Engenharia Civil, do ISEP, e resulta de um estágio proporcionado pela empresa Euromodal, tendo como orientador no ISEP o Engenheiro José Filinto Castro Trigo e supervisor na empresa Euromodal, o Engenheiro Francisco Quintas Araújo. A construção de pavilhões industriais recorrendo à pré-fabricação em betão armado é uma solução construtiv...

  12. Produção de levana e bioetanol utilizando cascas de banana por Zymomona mobilis

    OpenAIRE

    Ferreira, Juliana [UNESP

    2013-01-01

    Muitos países estão considerando razoável, e necessário, a curto e médio prazo, um constante investimento no estudo de formas, economicamente viáveis, de obtenção de fontes renováveis de energia, com grande destaque para a produção de etanol. O aproveitamento da matéria vegetal desperta grande interesse dos pesquisadores, cientistas e industriais, devido ao fato da mesma ser encontrada em grandes quantidades em vários tipos de resíduos. Por exemplo, só no Brasil, anualmente, tem-se uma geraçã...

  13. Improved photoluminescence quantum yield and stability of CdSe-TOP, CdSe-ODA-TOPO, CdSe/CdS and CdSe/EP nanocomposites

    Science.gov (United States)

    Wei, Shutian; Zhu, Zhilin; Wang, Zhixiao; Wei, Gugangfen; Wang, Pingjian; Li, Hai; Hua, Zhen; Lin, Zhonghai

    2016-07-01

    Size-controllable monodisperse CdSe nanocrystals with different organic capping were prepared based on the hot-injection method. The effective separation of nucleation and growth was achieved by rapidly mixing two highly reactive precursors. As a contrast, we prepared CdSe/CdS nanocrystals (NCs) successfully based on the selective ion layer adsorption and reaction (SILAR) technique. This inorganic capping obtained higher photoluminescence quantum yield (PLQY) of 59.3% compared with organic capping of 40.8%. Furthermore, the CdSe-epoxy resin (EP) composites were prepared by adopting a flexible ex situ method, and showed excellent stability in the ambient environment for one year. So the composites with both high PLQY of nanocrystals and excellent stability are very promising to device application.

  14. Thermoelectric transport of Se-rich Ag2Se in normal phases and phase transitions

    International Nuclear Information System (INIS)

    Mi, Wenlong; Lv, Yanhong; Qiu, Pengfei; Shi, Xun; Chen, Lidong; Zhang, Tiansong

    2014-01-01

    Small amount of Se atoms are used to tune the carrier concentrations (n H ) and electrical transport in Ag 2 Se. Significant enhancements in power factor and thermoelectric figure of merit (zT) are observed in the compositions of Ag 2 Se 1.06 and Ag 2 Se 1.08 . The excessive Se atoms do not change the intrinsically electron-conducting character in Ag 2 Se. The detailed analysis reveals the experiment optimum carrier concentration in Ag 2 Se is around 5 × 10 18  cm −3 . We also investigate the temperature of maximum zT and the thermoelectric transport during the first order phase transitions using the recently developed measurement system

  15. Contenha-se, se for capaz

    Directory of Open Access Journals (Sweden)

    Mirna Feitoza Pereira

    2008-11-01

    Full Text Available Em O Instinto da Linguagem, Steven Pinker discorre sobre sua célebre tese: a linguagem não é a mais prodigiosa invenção cultural humana. Ela é uma peça da constituição biológica do cérebro. A linguagem é uma habilidade complexa e especializada, que se desenvolve espontaneamente na criança, sem qualquer esforço consciente ou instrução formal, que se manifesta sem que se perceba sua lógica subjacente, que é qualitativamente a mesma em todo indiví­duo, e que difere de capacidades mais gerais de processamento de informações ou de comportamento inteligente. Para Pinker, a concepção de linguagem como um tipo de instinto transmite a idéia de que as pessoas sabem falar mais ou menos da mesma maneira que as aranhas sabem tecer suas teias. Ele apóia suas idéias em Darwin e Chomsky. Palavras-chave linguagem, gramática universal, evolução Abstract In Language Instinct, Steven Pinker argues about his famous thesis: language is not the most prodigious human cultural invention. It is a distinct piece of the biological constitution of the brain. Language is a complex, specialized skill, which develops spontaneously in the child, without conscious effort or formal instruction. It reveals itself without awareness of its underlying logic, which is qualitatively the same in every individual, and which is distinct from more general abilities of information processing of intelligent behavior. According to Pinker, the conception of language as a kind of instinct conveys the idea that people know how to talk in more or less the same way as spiders know how to spin webs. His thesis is founded in Darwin and Chomsky-s theories. Keywords language, universal grammar, evolution

  16. EPR of SeO2- and SeO3- radicals in alkaline borate glasses with 77Se isotope

    International Nuclear Information System (INIS)

    Galimov, D.G.; Tarzimanov, K.D.

    1977-01-01

    Alkaline borate glasses with 77 Se were investigated in order to establish the nature of selenium compounds and radicals in glasses. The relationship between alkali ions and the oxygen radical of selenium was determined by decoding the hyperfine structure of the alkaline borate glass EPR spectra obtained before and after γ-irradiation. The irradiated and non-irradiated glasses were characterized by hyperfine splitting of the EPR lines from the α- and β centres. Moreover, the irradiated samples were noted to have a line doublet (signal phi). With intenser reduction conditions of glass fusion, the intensities of α, β, and phi signals were noted to decline. This confirmes the suggestion that these centres were caused by oxygen compouds. The authors concluded that α and β signals were due to the paramagnetic centres of SeO 2 - and [SeO 2 - ]R + , and phi signal to the SeO 3 - radicals

  17. Copaiba oleoresin: evaluation of the presence of polycyclic aromatic hydrocarbons (PAHs

    Directory of Open Access Journals (Sweden)

    Wilson Gomes da Silva

    2010-09-01

    ça de hidrocarbonetos policíclicos aromáticos (HPAs no referido óleo-resina, como possíveis contaminantes. Os HPAs são compostos formados por dois ou mais aneis benzenicos e encontrados na atmosfera como resíduos provenientes das combustões incompletas dos derivados de petróleo e de atividades industriais. Esses compostos, preciptando-se da atmosfera, atingem terrenos, fontes de água e, consequentemente, os vegetais e gêneros alimentícios em geral. O uso de produtos contaminados com os sudetos compostos pode comprometer vidas humanas e animais. O estudo foi realizado com amostras do referido óleo-resina provenientes de diferentes áreas ou regiões da Amazônia, empregando-se a metodologia HPLC com detecção através de fluorescência.

  18. Se-Se isoelectronic centers in high purity CdTe

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, Rita; Andre, Regis; Mariette, Henri [CEA-CNRS, Nanophysique et Semiconducteurs, Institut Neel, 25 rue des martyrs, 38042 Grenoble (France); Golnik, Andrzej; Kossacki, Piotr; Gaj, Jan A. [Institute of Experimental Physics, University of Warsaw, Hoza 69, 00-681 Warsaw (Poland)

    2010-06-15

    We evidence zero-dimensional exciton states trapped on isoelectronic Se centers in CdTe quantum wells, {delta}-doped with Se. Thanks to special precautions taken to have very high purity CdTe heterostructures, it is possible to observe, in photoluminescence spectra, sharp discrete lines arising from individual centers related to the Se doping. These emission lines appear at about 40 meV below the CdTe band gap energy. The most prominent lines are attributed to the recombination of excitons bound to nearest-neighbor selenium pairs in a tetrahedral CdTe environment. This assignment is confirmed by a common linear polarization direction of the emitted light, parallel to <110>. These excitons localized on individual isoelectronic traps are good candidates as single photon emitters (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Sample Set (SE): SE30 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE30 Comparison of seed metabolites among soybean varieties Investigation of Glycine max. green seed metabol...ites. 3 varieties (Kamogawashichiri, Koitozairai, Tanbakuro) data are examined. Tak

  20. Sample Set (SE): SE13 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE13 Comparison of leaf metabolites among spinach varieties Investigation of Spinacia oleracea leaf metaboli...tes. 4 cultivers (Nihon, Kanaji, Kurohaminstarland and Wasesaradaakari) and 3 repli

  1. Influence of CdSe layer air-baking on physical properties of CdSe-As2Se3 heterostructures

    International Nuclear Information System (INIS)

    Schauer, F.; Heza, S.; Kosek, F.; Cimpl, Z.

    1980-01-01

    An investigation is made of the influence of the air-baking time on the physical properties of a CdSe layer, which is a part of the heterogeneous structure CdSe-As 2 Se 3 used as a camera tube target. The I-U characteristics, C-U characteristics, the dependence of both the real and imaginary part admittance on frequency, and the photoconductance characteristics are measured. All measurements are carried out on heterostructures prepared with variable air-baking time of the CdSe layer: t =0, 5, 15, 40, and 120 min. The results of measurements contribute to the finding of the optimal production procedure with a minimum baking time of tsub(min) = 15 min. The heterostructures exhibit satisfactory properties. The dark current Isub(d)(U =1 V, T = 300 K) = 10 -10 Acm -2 with a rectification factor g(U = 10 V) = 10 6 and a capacitance C (2 kHz) = 2900 pFcm -2 . (author)

  2. ZnSe MSM photodetectors prepared on GaAs and ZnSe substrates

    International Nuclear Information System (INIS)

    Lin, T.K.; Chang, S.J.; Su, Y.K.; Chiou, Y.Z.; Wang, C.K.; Chang, S.P.; Chang, C.M.; Tang, J.J.; Huang, B.R.

    2005-01-01

    Homoepitaxial and heteroepitaxial ZnSe metal-semiconductor-metal (MSM) photodetectors were both fabricated and characterized. It was found that homoepitaxial ZnSe MSM photodetector could provide us smaller dark current and large photocurrent. With an incident wavelength of 448 nm, it was found that the maximum responsivities for the homoepitaxial and heteroepitaxial ZnSe photodetectors were 0.128 and 0.045 A/W, which corresponds to a quantum efficiency of 36 and 12%, respectively. Furthermore, it was found that we achieved the minimum noise equivalent power (NEP) of 7.6 x 10 -13 W and the maximum normalized detectivity (D *) of 9.3 x 10 11 cm Hz 0.5 W -1 from our homoepitaxial ZnSe photodetector. In contrast, NEP and D * of the heteroepitaxial ZnSe photodetector were 2.9 x 10 -12 W and 2.44 x 10 11 cm Hz 0.5 W -1 , respectively

  3. SE PREVENINDO?

    Directory of Open Access Journals (Sweden)

    Ana Débora Assis Moura

    2010-01-01

    Full Text Available Este estudio tuvo como objetivo verificar el comportamiento de las prostitutas en relación a la prevención de enfermedades de transmisión sexual y del Síndrome de Inmunodeficiencia Adquirida-SIDA, así como investigar cómo se previenen de esas enfermedades. Se trata de una investigación exploratoria, con enfoque cualitativo, llevada a cabo en la Asociación de las Prostitutas en Ceará, Brazil, en septiembre de 2008, a través de una encuesta con 25 prostitutas. El análisis de los datos se hizo según el análisis de contenido, después de ser agrupados en cuatro categorías: conocimiento sobre las enfermedades de transmisión sexual/SIDA; convivencia con la(s enfermedad(es; prevención de la enfermedad de transmisión sexual/SIDA; y el uso de drogas. Se concluyó que las prostitutas no usan preservativos en todas las relaciones sexuales, por lo tanto, las enfermedades de transmisión sexual representan una realidad; la desinformación sobre la(s enfermedad(es es notable; el consumo de drogas lícitas e ilícitas es frecuente entre ellas, factor que las expone a situaciones más vulnerables con relación al VIH/SIDA.

  4. Qualidade de vida entre adolescentes: estudo seccional empregando o SF-12

    Directory of Open Access Journals (Sweden)

    Marise Fagundes Silveira

    2013-07-01

    Full Text Available A adolescência é um período em que comportamentos potencialmente lesivos ao estado de saúde podem ser iniciados. A avaliação da qualidade de vida nesse contingente torna-se útil para a identificação de grupos em maior risco para comprometimento do bem estar geral. O presente estudo objetivou avaliar a qualidade de vida e fatores associados em uma amostra de 754 adolescentes, com faixa etária de 15 a 19 anos. Para a mensuração da qualidade de vida foi utilizada a versão na língua portuguesa do questionário 12-Item Short-Form Health Survey (SF 12. Os resultados apontaram níveis satisfatórios de qualidade de vida, sendo estes maiores com a prática frequente de atividade física e a ausência de condições como atividades trabalhistas e consumo de tabaco e bebida alcóolica. O sexo feminino foi correlacionado a menores escores em aspectos mentais da qualidade de vida.

  5. Hot exciton relaxation in multiple layers CdSe/ZnSe self-assembled quantum dots separated by thick ZnSe barriers

    International Nuclear Information System (INIS)

    Eremenko, M; Budkin, G; Reznitsky, A

    2015-01-01

    We have studied PL and PLE spectra of two samples (A and B) of MBE grown CdSe/ZnSe asymmetric double quantum wells with different amount of deposited CdSe layers separated by 14 nm ZnSe barrier. It has been found that PLE spectra of the states forming short wavelength side of the PL spectra of both deep and shallow QWs of the sample A as well as that of deep QW of the sample B demonstrate oscillating structure in the spectral ranges corresponding to exciton states of self-assembled quantum dots only. Meanwhile PLE spectra of the short wavelength states of shallow QW the sample B revealed pronounced oscillating structure with energy period of ZnSe LO phonon under excitation with photons in a wide energy range both in the regions of quantum-dot states and in that of free states in the ZnSe barrier. In these spectra creating of excitons with kinetic energies more than 0.3 eV was observed which considerably exceed the exciton binding energy as well as LO phonon energy (both appr. 0.03 eV). It has been concluded that oscillating structure of the PLE spectra arises due to cascade relaxation of hot excitons. We discuss the model which explains these experimental findings. (paper)

  6. Hot exciton relaxation in multiple layers CdSe/ZnSe self-assembled quantum dots separated by thick ZnSe barriers

    Science.gov (United States)

    Eremenko, M.; Budkin, G.; Reznitsky, A.

    2015-11-01

    We have studied PL and PLE spectra of two samples (A and B) of MBE grown CdSe/ZnSe asymmetric double quantum wells with different amount of deposited CdSe layers separated by 14 nm ZnSe barrier. It has been found that PLE spectra of the states forming short wavelength side of the PL spectra of both deep and shallow QWs of the sample A as well as that of deep QW of the sample B demonstrate oscillating structure in the spectral ranges corresponding to exciton states of self-assembled quantum dots only. Meanwhile PLE spectra of the short wavelength states of shallow QW the sample B revealed pronounced oscillating structure with energy period of ZnSe LO phonon under excitation with photons in a wide energy range both in the regions of quantum-dot states and in that of free states in the ZnSe barrier. In these spectra creating of excitons with kinetic energies more than 0.3 eV was observed which considerably exceed the exciton binding energy as well as LO phonon energy (both appr. 0.03 eV). It has been concluded that oscillating structure of the PLE spectra arises due to cascade relaxation of hot excitons. We discuss the model which explains these experimental findings.

  7. Sample Set (SE): SE53 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE53 Covering chemical diversity of genetically-modified tomatoes using metabolomics...signature. We conclude that multi-platform metabolomics is an approach that is both sensitive and robust and

  8. Sample Set (SE): SE10 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE10 Effect of phosphorus nutrition for cabbage metabolites Investigation of Brassi...ca oleracea var. capitata Hatukoi leaf metabolites. 3 growth conditions (high, low and no phosphorus nutrition

  9. Sample Set (SE): SE31 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE31 Comparison of seed metabolites among eggplant fruit tissues Investigation of S...olanum melongena Senryounigou metabolites. 3 tissues (flesh, fruit, peel) data are examined. Takeshi Ara 1,

  10. Sample Set (SE): SE28 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE28 Comparison of leaf metabolites among developmental stages of Hevea brasiliensi...s Investigation of Hevea brasiliensis leaf metabolites. 4 developmental stages and 6 replicates data are exa

  11. Superconductivity in the ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n}

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Corinna; Chiatti, Olivio; Fischer, Saskia F. [Novel Materials Group, Humboldt-Universitaet Berlin (Germany); Alemayehu, Matti B.; Falmbigl, Matthias; Johnson, David C. [Department of Chemistry, University of Oregon, Eugene, OR (United States)

    2016-07-01

    The ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n} are artificially layered materials consisting of n NbSe{sub 2} single-layers stacked alternately with atomic double layers of PbSe. NbSe{sub 2} is a transition metal dichalcogenide with interesting electrical properties such as superconductivity and charge density waves. The influence of turbostratic disorder, a random rotation between the NbSe{sub 2} and PbSe layers, on the superconducting transition temperature has been unknown so far. We investigate the structural and temperature-dependent electrical properties of the ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n} by means of scanning transmission electron microscopy, X-ray diffraction, in-plane resistivity and Hall measurements and compare them to those of analogous non-disordered misfit layer compound (MLC) polymorphs. We observe a superconducting transition in the resistivity of the ferecrystals. The transition temperatures are reduced by up to 55 % with respect to the analogous MLC polymorphs. This indicates that turbostratic disorder substantially weakens the electron-phonon coupling in (PbSe){sub 1.14}(NbSe{sub 2}){sub n}. We discuss the results of the structural and electrical properties of the ferecrystals with respect to their MLC analogues and also with respect to ultra-thin NbSe{sub 2} layers.

  12. Impactos do ADTEN e do FNDCT sobre o Desempenho e os Esforços Tecnológicos das Firmas Industriais Brasileiras

    Directory of Open Access Journals (Sweden)

    Mauro Borges Lemos

    2009-10-01

    Full Text Available O objetivo deste trabalho é avaliar o impacto do Programa de Apoio ao Desenvolvimento Tecnológico da Empresa Nacional (ADTEN o do Fundo Nacional para o Desenvolvimento Científico e Tecnológico (FNDCT, administrado pela FINEP, sobre o desempenho econômico e tecnológico das empresas beneficiadas. O trabalho mostrou que os programas têm alcance relativamente pequeno para as dimensões da indústria brasileira. O programa atende menos de 0,1% das firmas industriais brasileiras com mais de dez pessoas ocupadas e o volume de recursos que são emprestados para as empresas no âmbito dos programas representam menos de 3% dos gastos realizados pelas próprias empresas em P&D no ano de 2000 e 2003. No período de 1996 a 2003, foram encontradas evidências robustas de que os programas influenciam positivamente os gastos privados de P&D das empresas, sugerindo a inexistência do chamado efeito crowding out. E há evidências também robustas de que os programas influenciam positivamente o crescimento das empresas.The present study, which assesses the impact of the National Technological Development Support Program (ADTEN and Scientific and Technological Development Fund (FNDCT, sponsored by the Research & Projects Financing Agency (FINEP, on the technical performance and strength of Brazilian industrial firms, is unprecedented in its content and method. It shows that this R&D incentive programs reaches a relatively limited number of firms, considering the magnitude of the Brazilian industrial sector. The program reaches less than 0,1% of Brazilian industrial firms with over ten employees, and the volume of resources that firms borrowed within the program’s framework was less than 3% of their R&D expenditures in 2000 and 2003. It was found evidences that Programs had a positive influence on companies’ private R&D expenditures from 1996 to 2003. One can say that at least the crowding out hypothesis can be rejected. There are also strong evidences

  13. Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S.K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India); Sharma, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India)

    2013-05-15

    Highlights: ► Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ► From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ► Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ► The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

  14. Sample Set (SE): SE20 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE20 Arabidopsis thaliana leaf metabolite analysis for a software test Investigatio...es that were investigated to optimize the parameters of PowerGet software for better metabolite annotation i

  15. Sample Set (SE): SE18 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available in by Orbitrap MS and automated search engine Lipid Search A comprehensive and precise identification of pho...SE18 Global identification of phospholipid molecular species in mouse liver and bra

  16. Electrochemical synthesis of nanostructured Se-doped SnS: Effect of Se-dopant on surface characterizations

    International Nuclear Information System (INIS)

    Kafashan, Hosein; Azizieh, Mahdi; Balak, Zohre

    2017-01-01

    Highlights: • Nanostructured SnS_1_-_xSe_x thin films were prepared by using electrodeposition method. • The XRD patterns obviously showed that the synthesized films were polycrystalline. • The PL spectra of SnS_1_-_xSe_x thin films showed four emission peaks. • The UV–vis spectra shows a variation in the optical band gap energy of SnS_1_-_xSe_x thin films from 1.22 to 1.65 eV. • SnS_1_-_xSe_x thin films would be suitable for use as absorber layers. - Abstract: SnS_1_-_xSe_x nanostructures with different Se-dopant concentrations were deposited on fluorine doped tin oxide (FTO) substrate through cathodic electrodeposition technique. The pH, temperature, applied potential (E), and deposition time remained were 2.1, 60 °C, −1 V, and 30 min, respectively. SnS_1_-_xSe_x nanostructures were characterized using X-ray diffraction (XRD), field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), room temperature photoluminescence (PL), and UV–vis spectroscopy. The XRD patterns revealed that the SnS_1_-_xSe_x nanostructures were polycrystalline with orthorhombic structure. FESEM showed various kinds of morphologies in SnS_1_-_xSe_x nanostructures due to Se-doping. PL and UV–vis spectroscopy were used to evaluate the optical properties of SnS_1_-_xSe_x thin films. The PL spectra of SnS_1_-_xSe_x nanostructures displayed four emission peaks, those are a blue, a green, an orange, and a red emission. UV–vis spectra showed that the optical band gap energy (E_g) of SnS_1_-_xSe_x nanostructures varied between 1.22–1.65 eV, due to Se-doping.

  17. Sample Set (SE): SE14 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE14 Effect of agricultural films for tomato fruit metabolites Investigation of Sol...anum lycopersicum fruit metabolites. 3 growth conditions (covered with normal or UV cut agricultural film or no agricultura

  18. Verificação da ocorrência do efeito índice no Ibovespa – 2004-2013

    Directory of Open Access Journals (Sweden)

    André Nardy

    2015-06-01

    Full Text Available RESUMO No artigo, analisa-se a ocorrência de retornos e volumes anormais para as ações adicionadas ao Ibovespa entre 2004 e 2013, no contexto do efeito índice, uma das anomalias de mercado mais antigas relatadas em finanças, empregando-se a metodologia de estudo de evento. Diferentemente de outros estudos, encontram-se retornos anormais positivos próximos aos dias que antecedem a data de efetivação do índice à nova carteira. Os resultados são invertidos para períodos de estimação superiores àquele de apuração do índice. Os volumes são anormalmente altos. A não persistência dos retornos anormais ao longo da janela de entrada é coerente com a hipótese de pressão de preços e pode ser considerada coerente com a forma de eficiência semiforte de mercado.

  19. Influência da concentração de soro de leite e de amido modificado sobre algumas características de composição de bebidas lácteas não fermentadas

    Directory of Open Access Journals (Sweden)

    Shana P. Ferreira

    2009-12-01

    Full Text Available Este trabalho teve como objetivo estudar a influência da concentração de soro de leite (26, 30, 40, 50 e 54% e de amido modificado (0,1; 0,2; 0,4; 0,6 e 0,7% sobre os teores de lactose, sólidos totais e acidez titulável de bebidas lácteas não fermentadas. Foram elaboradas 11 formulações empregando-se o planejamento estatístico Delineamento Composto Central Rotacional (DCCR para avaliar a influência dos fatores estudados, sobre as variáveis avaliadas. Para análise estatística dos resultados realizou-se análise de regressão. Constatou-se que as concentrações de soro avaliadas apresentaram efeito significativo sobre os teores de lactose, sólidos totais e acidez titulável, e o amido modificado não apresentou efeito significativo.

  20. As primeiras indústrias, a arquitetura utilitária e o espaço fabril em Santa Cruz do Sul

    Directory of Open Access Journals (Sweden)

    Camila Prus

    2016-10-01

    Full Text Available O objetivo do presente trabalho é descrever a história da indústria de sua origem até 1930, destacando o vínculo colono-industrialização, a origem dos primeiros estabelecimentos industriais, os condicionantes para o desenvolvimento da mesma, a arquitetura empregada nos prédios fabris e sua situação atual. O trabalho baseou-se em análises de imagens encontradas nos arquivos do Centro de Documentação da Universidade de Santa Cruz do Sul (CEDOC, e fontes bibliográficas constituídas por livros, jornais, periódicos e meio eletrônico. Dessa forma, o trabalho permite entender o contexto histórico e a dinâmica pela qual a cidade e a indústria foram estruturando-se no território santa - cruzense, como também, identificar e analisar as edificações da arquitetura industrial e como a mesma se relaciona/relacionou com a paisagem urbana.

  1. Projeto de Redução do Desperdício de Matéria-Prima: Estudo de Caso na Indústria de Embalagens de Papel no Brasil

    Directory of Open Access Journals (Sweden)

    Gleison Hidalgo Hidalgo Martins

    2014-02-01

    Full Text Available Pode-se dizer que em se tratando de produção industrial os desperdícios que podem ocorrer ao longo dos processos são diversos, vão de matéria-prima à recursos financeiros. No entanto pode-se classificar o desperdício de matéria-prima como sendo o mais urgente deste setor e também o mais passivo de ser estudado, uma vez que impacta diretamente no fluxo fabril e na quantidade do produto acabado. O conteúdo desta pesquisa apresenta argumentos através de embasamento teórico e prático que apontam para a importância de trabalhos sobre as possíveis causas do problema do desperdício de matéria-prima nas linhas industriais de embalagem de papel assim como as formas de combater e reagir ao problema.DOI:10.5585/gep.v4i3.186

  2. Properties of the CuGaSe2 and CuInSe2 (001) surface

    International Nuclear Information System (INIS)

    Deniozou, T.

    2005-01-01

    The main task of this work was to investigate the (001) CuGaSe 2 and CuInSe 2 surface in dependence of preparation and stoichiometry. The knowledge of the atomic structure as well as other surface properties is important in respect to optimization of novel thin film solar cells. For the characterization of the layers mainly Auger electron Spectroscopy, low-energy electron diffraction and photoelectron spectroscopy were implemented. The development of an appropriate procedure with Ar + sputtering and annealing combined with decapping enabled the preparation of clean and well-ordered surfaces. Different surface structures were observed in dependence of the layer preparation and composition. A (4 x 1) reconstruction was observed for the first time on CuGaSe 2 layers grown with a moderate Cu-excess after preparation by sputtering and annealing. Similarly a (4 x 2) reconstruction was detected on CuInSe2 surfaces of Cu-poor layers. A reconstruction could be also observed on Cu-poorer layers, however the facets/steps could not be completely removed. Cu-richer layers were facet-free, however the observed reconstruction was also weaker. Thus it was shown that in contrary to recent expectations, according to which only the (112) surface is stable, also the (001) can be stable under particular conditions. The appearance of facets or steps is correlated with the presence of CuIn 3 Se 5 or CuGa 3 Se 5 phases. This information is furthermore important for the understanding of grain boundaries in polycrystalline CuGaSe 2 and CuInSe 2 . Binding energy shifts were observed for the first time on all Se3d, In4d, Ga3d, Cu3d core levels of the reconstructed surfaces. By comparison with results from the literature from the similar ZnSe (100) surface a modell for the (4 x 2) reconstruction was proposed. The surface components in the Se3d, In4d and Cu3d emission were attributed to Se dimers or In and Cu adatoms respectively. The x 1 periodicity of the (4 x 1) reconstruction of CuGaSe 2 is

  3. Sample Set (SE): SE16 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE16 Effect of agricultural films for spinach leaf metabolites 2 Investigation of S...pinacia oleracea leaf metabolites. 3 growth conditions (covered with normal or UV cut agricultural film or no agricultura

  4. Sample Set (SE): SE26 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE26 Effect of compost for cabbage metabolites Investigation of Brassica oleracea v...ar. capitata YR Seisyun leaf metabolites. 2 growth conditions (with or without 6t compost treatment) and 3 r

  5. Stable and metastable equilibria in PbSe + SnI2=SnSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Demidova, E.D.

    2003-01-01

    T-x-y phase diagrams of the PbSe + SnI 2 =SnSe + PbI 2 mutual system (stable states) are plotted for the first time. It is shown that melt, solid solutions on the base of components of the mutual system and phase on the base of Sn 2 SeI 4 take part in phase equilibria. Transformations in the PbSe + SnI 2 =SnSe + PbI 2 mutual system leading to crystallization of metastable polytype modifications of lead iodides and metastable ternary compound forming in PbSe-PbI 2 system are investigated for the first time [ru

  6. Copper Selenidophosphates Cu4P2Se6, Cu4P3Se4, Cu4P4Se3, and CuP2Se, Featuring Zero-, One-, and Two-Dimensional Anions.

    Science.gov (United States)

    Kuhn, Alexander; Schoop, Leslie M; Eger, Roland; Moudrakovski, Igor; Schwarzmüller, Stefan; Duppel, Viola; Kremer, Reinhard K; Oeckler, Oliver; Lotsch, Bettina V

    2016-08-15

    Five new compounds in the Cu/P/Se phase diagram have been synthesized, and their crystal structures have been determined. The crystal structures of these compounds comprise four previously unreported zero-, one-, and two-dimensional selenidophosphate anions containing low-valent phosphorus. In addition to two new modifications of Cu4P2Se6 featuring the well-known hexaselenidohypodiphosphate(IV) ion, there are three copper selenidophosphates with low-valent P: Cu4P3Se4 contains two different new anions, (i) a monomeric (zero-dimensional) selenidophosphate anion [P2Se4](4-) and (ii) a one-dimensional selenidophosphate anion [Formula: see text], which is related to the well-known gray-Se-like [Formula: see text] Zintl anion. Cu4P4Se3 contains one-dimensional [Formula: see text] polyanions, whereas CuP2Se contains the 2D selenidophosphate [Formula: see text] polyanion. It consists of charge-neutral CuP2Se layers separated by a van der Waals gap which is very rare for a Zintl-type phase. Hence, besides black P, CuP2Se constitutes a new possible source of 2D oxidized phosphorus containing layers for intercalation or exfoliation experiments. Additionally, the electronic structures and some fundamental physical properties of the new compounds are reported. All compounds are semiconducting with indirect band gaps of the orders of around 1 eV. The phases reported here add to the structural diversity of chalcogenido phosphates. The structural variety of this family of compounds may translate into a variety of tunable physical properties.

  7. Exciton dephasing and biexciton binding in CdSe/ZnSe islands

    DEFF Research Database (Denmark)

    Wagner, Hans Peter; Tranitz, H.-P.; Preis, H

    1999-01-01

    The dephasing of excitons and the formation of biexcitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of exciton-exciton scattering efficiencies and dephasing times in the range of 0.5-10 ps...

  8. Simultaneous tracing of 76Se-selenite and 77Se-selenomethionine by absolute labeling and speciation

    International Nuclear Information System (INIS)

    Suzuki, Kazuo T.; Somekawa, Layla; Kurasaki, Kazuki; Suzuki, Noriyuki

    2006-01-01

    Nutritional selenocompounds are transformed into the assumed common intermediate selenide, which is utilized for the synthesis of selenoenzymes or transformed into methylated metabolites for excretion. Hence, selenocompound metabolites can be traced only with labeled selenium. Here we applied a new tracer method for the metallomics of biometals using simultaneous speciation of each metallome labeled with different homo-elemental isotopes to metabolism and availability of selenium. Rats were depleted of endogenous natural abundance selenium by feeding a single selenium stable isotope ( 82 Se-selenite) and then administered 76 Se-selenite and 77 Se-selenomethionine ( 77 Se-SeMet)simultaneously. Biological samples were subjected to quantification and speciation analysis by HPLC-ICPMS. Metabolites of the labeled 76 Se and 77 Se and interaction with endogenous selenium were traced and examined without interference from the corresponding endogenous natural abundance isotopes. Differences in the distribution and metabolism among organs and between the two nutritional selenocompounds were compared under exactly identical biological and analytical conditions: (1) selenite was distributed more efficiently than SeMet in organs and body fluids except the pancreas. (2) SeMet was taken up by organs in its intact form. (3) Selenium of SeMet origin was distributed selectively in the pancreas and mostly bound to a protein together with intact SeMet. (4) Selenosugars A and B but not trimethylselenonium (TMSe) were detected in the liver. (5) Selenosugar B and TMSe were detected in the kidneys

  9. Electrochemical synthesis of nanostructured Se-doped SnS: Effect of Se-dopant on surface characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Kafashan, Hosein, E-mail: hosein840521@gmail.com; Azizieh, Mahdi; Balak, Zohre

    2017-07-15

    Highlights: • Nanostructured SnS{sub 1-x}Se{sub x} thin films were prepared by using electrodeposition method. • The XRD patterns obviously showed that the synthesized films were polycrystalline. • The PL spectra of SnS{sub 1-x}Se{sub x} thin films showed four emission peaks. • The UV–vis spectra shows a variation in the optical band gap energy of SnS{sub 1-x}Se{sub x} thin films from 1.22 to 1.65 eV. • SnS{sub 1-x}Se{sub x} thin films would be suitable for use as absorber layers. - Abstract: SnS{sub 1-x}Se{sub x} nanostructures with different Se-dopant concentrations were deposited on fluorine doped tin oxide (FTO) substrate through cathodic electrodeposition technique. The pH, temperature, applied potential (E), and deposition time remained were 2.1, 60 °C, −1 V, and 30 min, respectively. SnS{sub 1-x}Se{sub x} nanostructures were characterized using X-ray diffraction (XRD), field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), room temperature photoluminescence (PL), and UV–vis spectroscopy. The XRD patterns revealed that the SnS{sub 1-x}Se{sub x} nanostructures were polycrystalline with orthorhombic structure. FESEM showed various kinds of morphologies in SnS{sub 1-x}Se{sub x} nanostructures due to Se-doping. PL and UV–vis spectroscopy were used to evaluate the optical properties of SnS{sub 1-x}Se{sub x} thin films. The PL spectra of SnS{sub 1-x}Se{sub x} nanostructures displayed four emission peaks, those are a blue, a green, an orange, and a red emission. UV–vis spectra showed that the optical band gap energy (E{sub g}) of SnS{sub 1-x}Se{sub x} nanostructures varied between 1.22–1.65 eV, due to Se-doping.

  10. Emprego do carvão ativado e de uma protease do Bacillus subtilis na obtenção de hidrolisados protéicos de leite com baixo teor de fenilalanina
    Use of activated carbon and a protease from Bacillus subtilis for obtaining milk protein hydrolysates

    Directory of Open Access Journals (Sweden)

    M. W. S. SOUZA

    2010-09-01

    Full Text Available

    Considerando a importância do leite na dieta do brasileiro e a sua restrição para pacientes fenilcetonúricos, este trabalho teve como objetivo reduzir o teor de fenilalanina (Phe deste alimento. Para isso, vários hidrolisados enzimáticos foram preparados, empregando uma protease do Bacillus subtilis e testando diversos parâmetros de reação, como o efeito do tempo, da temperatura e da relação E:S. A remoção da Phe foi realizada empregando o carvão ativado (CA como meio adsorvente, e avaliou-se as relações proteína:CA de 1:22, 1:44 e 1:88. A efi ciência da remoção foi avaliada por espectrofotometria derivada segunda, determinando-se o teor de Phe livre no leite e em seus hidrolisados, após tratamento com CA. A maior remoção de Phe (75,9% foi obtida com o tempo de 5h, a temperatura de 50ºC, a relação E:S de 4:100 e a relação proteína:CA de 1:22. Este ensaio originou um leite com teor fi nal de 36,9mg de Phe/100ml, o que permitiria a utilização do mesmo por pacientes fenilcetonúricos.

  11. Análise da complexidade, estratégias e aprendizagem em projetos de melhoria contínua: estudos de caso em empresas brasileiras Analysis of complexity, strategies, and learning organization in continuous improvement processes: case studies in brazilian companies

    Directory of Open Access Journals (Sweden)

    Pedro Carlos Oprime

    2010-12-01

    Full Text Available O objetivo deste artigo é analisar projetos de melhoria contínua desenvolvidos por empresas industriais brasileiras com base na abordagem/programa da Manutenção Produtiva Total (Total Productive Maintenance, TPM e da Qualidade Total (Total Quality Management, TQM. As variáveis estudadas nas análises dos projetos foram as seguintes: i complexidade dos projetos; ii seus objetivos específicos; iii as estratégias competitivas relacionadas; iv o aprendizado organizacional obtido; e v as ferramentas e os principais pilares do TPM implementados. Selecionou-se para estudo projetos considerados de sucesso por suas empresas. Ao todo, analisaram-se 42 projetos de 12 diferentes empresas que representaram diversos segmentos industriais do Brasil. Os resultados indicaram correspondência entre a natureza do projeto, em termos da sua complexidade e estrutura organizacional, com a estratégia competitiva adotada.This paper analyses the major goals and results of TPM and TQM processes in companies that adopt these approaches. The main variables considered in this study were: i complexity of the projects developed by the companies; ii projects´ specific goals iii relationship between the projects and the company's strategy; iv relationship between projects and continuous improvement and organizational learning; v tools and TPM concepts that support the projects. A descriptive research was carried out using field research strategies. Forty-two processes adopted by 12 companies were analyzed in this study. The processes implemented were considered successful by the companies that adopt them and by outside specialists. The results indicated close relationship between the project`s nature (its complexity and team structure and the company`s strategy, project goals and organizational learning.

  12. A transferable force field for CdS-CdSe-PbS-PbSe solid systems

    Science.gov (United States)

    Fan, Zhaochuan; Koster, Rik S.; Wang, Shuaiwei; Fang, Changming; Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W.; van Huis, Marijn A.; Vlugt, Thijs J. H.

    2014-12-01

    A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., "Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth," Nano Lett. 14, 3661-3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

  13. A transferable force field for CdS-CdSe-PbS-PbSe solid systems

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhaochuan; Vlugt, Thijs J. H., E-mail: t.j.h.vlugt@tudelft.nl [Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft,The Netherlands (Netherlands); Koster, Rik S.; Fang, Changming; Huis, Marijn A. van [Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht (Netherlands); Wang, Shuaiwei [Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, Henan 450006 (China); Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

    2014-12-28

    A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., “Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth,” Nano Lett. 14, 3661–3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

  14. Determination of K shell fluorescence cross-section and Kβ/Kα intensity ratios for Fe, Se, Te, FeSe, FeTe and TeSe

    International Nuclear Information System (INIS)

    Saydam, M.; Aksoy, C.; Cengiz, E.; Alaşalvar, C.; Tıraşoğlu, E.; Apaydın, G.

    2012-01-01

    The fluorescence cross-sections (σ Ki ) and the intensity ratios K β /K α for pure Fe, Se, Te elements and FeSe, FeTe, TeSe complexes have been investigated. The samples were excited by 59.5 keV γ-rays from 241 Am annular radioactive source and emitted X-rays. They were counted by an Ultra-LEGe detector with resolution of 150 eV at 5.9 keV. For pure elements results have been compared with the theoretical calculated values. According to our results band length and mutual interaction of atoms affected the results. We claimed that these effects would help researchers who study on superconductors, especially determining which compound can be show the superconductor properties. - Highlights: ► TeSe, FeSe and FeTe complexes have affected each other in terms of charge transfer. ► Fe excitement and enhancement have been made by Se and Te. ► Attractive interactions between electrons can help to becoming superconductivity.

  15. Tratamento descentralizado de esgotos de empreendimentos comercial e residencial empregando a ecotecnologia dos wetlandsconstruídos

    Directory of Open Access Journals (Sweden)

    Camila Maria Trein

    Full Text Available ResumoO objetivo deste trabalho é apresentar o desempenho dos wetlandsconstruídos de fluxo vertical (WCFV submetidos a diferentes carregamentos orgânicos e hidráulicos, a fim de incorporar esta tecnologia como opção no tratamento descentralizado de esgotos em empreendimentos comercial e residencial. Avaliou-se ao longo de dois anos dois sistemas de tratamento: (i sistema 1 - empreendimento comercial: composto por um Reator Aneróbio Compartimentado (RAC seguido de WCFV (área superficial total de 189 m2; (ii sistema 2 - condomínio residencial: composto pela sequência RAC e WCFV com fundo saturado (área superficial total de 3.141 m2. Com o monitoramento operacional e analítico junto aos wetlands, determinaram-se taxas hidráulicas aplicadas variando de 130 a 12 mm.d-1 e carregamentos médios aplicados variando de 87 a 1,9 gDQO m-2.d-1 para os sistemas 1 e 2, respectivamente. Os distintos carregamentos foram resultantes da demanda atual dos empreendimentos, sendo que os sistemas 1 e 2 apresentaram eficiências médias globais de remoção em termos de concentração de 75% e 93% para DQO, de 88% e 97% para DBO e de 83% e 94% para SS, respectivamente. A partir dos resultados obtidos, recomenda-se a utilização dos WCFV como alternativa tecnológica de tratamento de esgoto sob o contexto da descentralização.

  16. AgSbSe2 and AgSb(S,Se)2 thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    Garza, J.G.; Shaji, S.; Rodriguez, A.C.; Das Roy, T.K.; Krishnan, B.

    2011-01-01

    Silver antimony selenide (AgSbSe 2 ) thin films were prepared by heating sequentially deposited multilayers of antimony sulphide (Sb 2 S 3 ), silver selenide (Ag 2 Se), selenium (Se) and silver (Ag). Sb 2 S 3 thin film was prepared from a chemical bath containing SbCl 3 and Na 2 S 2 O 3 , Ag 2 Se from a solution containing AgNO 3 and Na 2 SeSO 3 and Se thin films from an acidified solution of Na 2 SeSO 3 , at room temperature on glass substrates. Ag thin film was deposited by thermal evaporation. The annealing temperature was 350 deg. C in vacuum (10 -3 Torr) for 1 h. X-ray diffraction analysis showed that the thin films formed were polycrystalline AgSbSe 2 or AgSb(S,Se) 2 depending on selenium content in the precursor films. Morphology and elemental analysis of these films were done using scanning electron microscopy and energy dispersive X-ray spectroscopy. Optical band gap was evaluated from the UV-visible absorption spectra of these films. Electrical characterizations were done using Hall effect and photocurrent measurements. A photovoltaic structure: glass/ITO/CdS/AgSbSe 2 /Al was formed, in which CdS was deposited by chemical bath deposition. J-V characteristics of this structure showed V oc = 435 mV and J sc = 0.08 mA/cm 2 under illumination using a tungsten halogen lamp. Preparation of a photovoltaic structure using AgSbSe 2 as an absorber material by a non-toxic selenization process is achieved.

  17. Highly luminescent CdSe/ZnSe core-shell quantum dots of one-pot preparation in octadecene

    NARCIS (Netherlands)

    Zeng, Q.; Kong, X.; Zhang, Y.; Zhang, H.

    2008-01-01

    CdSe/ZnSe core-shell quantum dots were synthesized using a new one-pot procedure where the core was prepared in octadecene. A ZnSe shell around a CdSe nanoparticle was formed by the reaction of selenium-richness on the surfaces of CdSe nanoparticles with Zn2+ from the injected zinc stearate

  18. Study of the 76788082Se(d,p)77798183Se reactions using polarized deuterons

    International Nuclear Information System (INIS)

    Montestruque, L.A.

    1978-01-01

    Differential cross sections and vector analyzing powers were measured at an incident deuteron energy of 12.5 MeV for the 76 78 80 82 Se(d,p) 77 79 81 83 Se reactions. The data are compared with the predictions of the DWBA theory to determine the l-value, spin, parity and spectroscopic factor of the resolved states. High resolution measurements were made with a 100 cm broad-range magnetic spectrograph to determine the excitation energies of the states studied, and the possible existence of contaminants in the targets. Definitive spin and parity assignments are made to 16 states in 77 Se, 22 states in 79 Se, 17 states in 81 Se, and 18 states in 83 Se, fifteen of which were previously assigned. In addition, tentative spin assignments were made to one state in 83 Se. The spectrograph measurements allowed the determination of the excitation energies of anumber of additional states in each isotope. Among the 76 states studied in this work, ther are 8 2P/sub 3/2/ states, 4 1F/sub 5/2/ states 6 2P/sub 1/2/ states 4 1G/sub 9/2/ states, 31 2D/sub 5/2/ states, 10 3S/sub 1/2/ states, and 13 2D/sub 3/2 states. A sum-rule analysis was made and the results compared to previous work and to the predictions of the simple pairing theory

  19. A decisão de encerrar as operações: Uma abordagem das alternativas em indústrias maduras

    Directory of Open Access Journals (Sweden)

    Marcelo Silva Pinho

    2009-10-01

    Full Text Available Não é incomum que avaliações de empresas industriais reultem na constatação de que os lucros obtidos, ainda que expressivos, são insuficientes para assegura um adequada remuneração ao capital empregado. Nesses casos, o valor que se pode obter com a liquidação dos seus ativos, mesmo depois de saldadas todas suas obrigações, supera o valor presente do fluxo de caixa que se espera seja gerado pelo negócio. Olhando o mesmo problema por um prisma ligeiramente distinto, teríamos uma situação em que a taxa de desconto aplicável é maior que a taxa interna de retorno obtida pela comparação entre o preço de liquidação e os rendimetos futuros projetados.

  20. Composição e distribuição espacial e sazonal de anfíbios em unidade de conservação da Mata Atlântica, Alfredo Chaves, Espírito Santo

    OpenAIRE

    Dantas, Roberto de Barros

    2009-01-01

    Este estudo objetivou determinar a composição e distribuição espacial e sazonal de anfíbios anuros da Reserva Particular do Patrimônio Natural Oiutrem, fragmento de Mata Atlântica, região de montanha, Alfredo Chaves, Espírito Santo, Brasil, bem como testar a correlação das variáveis climáticas sobre a atividade de vocalização dessas espécies. As amostragens ocorreram de janeiro de 2008 a fevereiro de 2009, empregando-se os métodos de busca ativa e armadilhas de interceptação e queda (pitfalls...

  1. Efeito hipinótico de ecdisterona isolada de Pfaffi a glomerata (Spreng.) Pedersen

    OpenAIRE

    Fenner, Raquel; Zimmer, Aline Rigon; Neves, Gilda Angela; Kliemann, Michele Patricia; Gosmann, Grace; Rates, Stela Maris Kuze

    2008-01-01

    Neste trabalho foi avaliado, em roedores, o efeito depressor das frações clorofórmio (CHCl3), acetato de etila (EtOAc) e n-butanol, obtidas das partes subterrâneas de Pfaffi a glomerata, empregando-se o teste de tempo de sono barbitúrico como referência. Somente a fração lipofílica (CHCl3:EtOAc, 1:1, m/m) (i.p. 500 mg/kg; v.o. 1000 mg/kg) potenciou o tempo de sono induzido por pentobarbital. A ecdisterona foi isolada e identifi cada como constituinte majoritário (1,4% m/m) desta fração, atrav...

  2. Etch Pit Studies of II-VI-Wide Bandgap Semiconductor Materials ZnSe, ZnCdSe, and ZnCdMgSe Grown on InP

    National Research Council Canada - National Science Library

    Semendy, Fred

    1999-01-01

    Etch pit density (EPD) determination studies have been conducted on II-VI semiconductor materials ZnSe, ZnCdSe, and ZnCdMgSe grown on InP surfaces for the first time by using various etching solutions under different...

  3. Avaliação ambiental do setor calçadista sob a ótica da gestão de resíduos sólidos

    OpenAIRE

    Silva, Adriana Hoenisch da

    2016-01-01

    Com a crescente e efetiva preocupação com o meio ambiente, com o uso de recursos não renováveis, a gestão da reutilização e reciclagem e não por menos, da geração de resíduos, industriais, tem sido o interesse de pesquisas e projetos. O produto calçado utiliza em seu processo de fabricação diversos tipos de materiais e recursos. Assim, pode-se considerar o processo produtivo como uma interessante fonte de oportunidades do uso de ferramentas ambientais e estudos de caso para reduzir os impacto...

  4. Estudo de ferramentas de avaliação de maturidade em projetos de capital

    OpenAIRE

    Pedro Rocha Galvao Junior

    2013-01-01

    O estudo das formas como é feita a concepção dos mega empreendimentos, os chamados projetos de capital, têm crescido em importância, tanto nos meios acadêmicos como empresariais, principalmente nos segmentos industriais. Nesse contexto, torna-se importante estudar e avaliar o nível de definição ou maturidade na fase de concepção desses projetos. Este trabalho faz uma análise comparativa de métodos de avaliação do grau de definição da fase de concepção de projetos de capital, destacando a util...

  5. Arquitetura Industrial em Recife: uma face da modernidade

    OpenAIRE

    Maria Vieira Caldas, Renata

    2010-01-01

    Construções ligadas aos processos produtivos (produção, estocagem, distribuição e comercialização) são constituintes de um abrangente grupo denominado edifícios industriais. De um modo geral, estas construções se desenvolveram como parte de dois fenômenos cruciais da modernidade: a mecanização e a industrialização; o que fez delas uma de suas faces ou expressão. Num movimento de redução de suas formas ao estritamente necessário, o edifício industrial passou, ele próprio, a s...

  6. Notas sobre a contribuição do desenho industrial á arquitetura e a cidade

    OpenAIRE

    Alessandro Ventura

    2000-01-01

    A principal preocupação do texto é discutir o uso de técnicas industriais pela arquitetura e refletir sobre suas repercussões na cidade. Nesta discussão procura-se estabelecer uma relação entre as técnicas de projeto do desenho industrial e da arquitetura, focalizando-a dentro de uma forma de pensamento produtivo típico da indústria. Abordamos a idéia de produção na cidade, procurando mostrar que seu desenho é fruto dos produtos que lhe são impostos e não por aqueles gerados por suas necessid...

  7. RELIGIOSIDADE POPULAR E FENOMENOLOGIA RELIGIOSA

    Directory of Open Access Journals (Sweden)

    Waldomiro O. Piazza

    1980-01-01

    Full Text Available Antes de tudo, é preciso ter presente que religiosidade popular não é o mesmo que fenomenologia religiosa, embora estejam intimamente vinculadas entre si. A fenomenologia religiosa é uma ciência que estuda o significado profundo das várias atitudes religiosas que o homem toma motivado por uma experiência religiosa. A religiosidade popular é o complexo destas atitudes condicionadas por alguma estrutura cultural, como a dos primitivos, que se dedicavam à caça, à pesca, à coleta de frutos, ou a dos povos sedentários, dedicados às técnicas agrárias e industriais.

  8. Pesquisa odontológica no estado de Minas Gerais - Brasil: análise retrospectiva de 1986 a 2006

    OpenAIRE

    Júnior, Hercílio Martelli; Júnior, João Róbson Vieira; Domingos, Mônica Ágda; Barbosa, Daniella Reis; Júnior, Manoel Brito; Bonan, Paulo Rogério Ferreti

    2016-01-01

    A Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Fapemig) é a única agência de fomento à pesquisa científica, tecnológica e inovação do Estado. Foi criada em 1985 e implantada em 1986, com espírito e relevo de urgência para se incorporar à tecnologia aos setores industriais. Em decorrência da escassez de estudos mapeando a produção científica e o envolvimento das Faculdades de Odontologia, no Estado de Minas Gerais, este estudo teve como objetivo estabelecer o perfil dos projetos de...

  9. A economia cafeeira no Vale do Paraíba paulista na República Velha: uma avaliação

    OpenAIRE

    Ricci, Fábio

    2008-01-01

    O artigo apresenta, com base em bibliografia e documentação uma interpretação de como, em que pese ser a produção cafeeira no vale do Paraíba Paulista decadente, a política de valorização do café manteve um fluxo de capital para a região suficiente para a manutenção das atividades econômicas e de uma estrutura física e de capitais acumulados que se direcionaram para as atividades manufatureiras e industriais, em particular o setor têxtil. A proximidade com os dois principais centros urbanos d...

  10. Análise de riscos nas indústrias petroquímicas: atmosferas explosivas

    OpenAIRE

    Chu, Jorge Nobre

    2014-01-01

    Dissertação de Mestrado em Segurança e Higiene do Trabalho São inúmeras as atividades industriais que no seu processo fabril estão presentes substâncias inflamáveis que poderão criar atmosferas potencialmente explosivas sob a forma de gases ou vapores. Segundo a diretiva ATEX dever-se-á estabelecer áreas de risco, onde deveram ser adotadas precauções especiais para evitar a ignição ativa e a permanência da concentração dos gases no local. Esta dissertação estuda os fenómenos da criação ...

  11. Roteiro Tecnológico (roadmap) da Captação, Utilização e Armazenamento de Dióxido de Carbono (CCUS) em Portugal

    OpenAIRE

    Oliveira, Gisela Marta Teixeira de Sousa

    2016-01-01

    O objetivo primordial deste trabalho foi estabelecer um roteiro tecnológico para aplicação das tecnologias de “Captação, Utilização e Sequestração de Carbono - CCUS” em Portugal. Para o efeito procedeu-se à identificação da origem das maiores fontes emissoras estacionárias industriais de CO2, adotando como critério o valor mínimo de 1×105 ton CO2/ano e limitado apenas ao território continental. Com base na informação recolhida e referente aos dados oficiais mais recentes (ano d...

  12. Avaliação da resistência ao rasgamento do silicone submetido à ação de suor artificial

    OpenAIRE

    Teresa Camargo de Castro

    2008-01-01

    O Silicone é um material semi-orgânico, obtido a partir de processos industriais e classificado como polimérico. Ele tem basicamente em sua composição átomos de silício ligados a oxigênio e radicais contendo carbono o que confere ao material, características físico-químicas particulares como inércia química e estabilidade dimensional, mantendo-se íntegro nos mais diversos meios de aplicação. Dentre um sem número de utilizações, o silicone tem indicação na confecção de próteses faciais por apr...

  13. Análise da qualidade da água superficial do Rio Subaé, Bahia e influência do uso e ocupação do solo em seu entorno

    OpenAIRE

    Santos, Leila Thaíse Santana de Oliveira

    2013-01-01

    A bacia do rio Subaé (BRS), cuja nascente localiza-se em Feira de Santana-BA e sua foz na Baía de Todos os Santos, apresenta sérios impactos ambientais nos seus principais cursos d’água decorrentes do despejo de efluentes domésticos e industriais, atividades agropecuária e extrativista. O presente estudo teve como objetivo realizar análise dos processos físico-químicos e microbiológico da água superficial no trecho ainda não estudado ao longo do canal principal do rio Subaé e análise dos proc...

  14. OTIMIZAÇÃO DE SEÇÕES POLIGONAIS DE ELEMENTOS LINEARES DE CONCRETO ARMADO SUJEITAS À FLEXÃO COMPOSTA

    OpenAIRE

    de Faria, Flávia Castro; da Silva, Amilton Rodrigues

    2017-01-01

    Resumo. O concreto é o material mais utilizado na confecção de elementos estruturais para a construção civil no mundo. Devido à sua baixa resistência à tração ele é reforçado com barras de aço formando o concreto armado. Elementos lineares de concreto armado são comuns em edifícios de múltiplos pavimentos, pontes, galpões industriais, entre outros. O objetivo desse trabalho é utilizar um algoritmo de otimização para definir a quantidade de aço e sua posição dentro de uma seção poligonal qualq...

  15. Synthesis of ZnSe and ZnSe:Cu quantum dots by a room temperature photochemical (UV-assisted) approach using Na2 SeO3 as Se source and investigating optical properties.

    Science.gov (United States)

    Khafajeh, R; Molaei, M; Karimipour, M

    2017-06-01

    In this study, ZnSe and ZnSe:Cu quantum dots (QDs) were synthesized using Na 2 SeO 3 as the Se source by a rapid and room temperature photochemical (UV-assisted) approach. Thioglycolic acid (TGA) was employed as the capping agent and UV illumination activated the chemical reactions. Synthesized QDs were successfully characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) and UV-visible (UV-vis) spectroscopy, Fourier transform-infrared (FT-IR), and energy dispersive X-ray spectroscopy (EDX). XRD analysis demonstrated the cubic zinc blend phase QDs. TEM images indicated that round-shaped particles were formed, most of which had a diameter of about 4 nm. The band gap of the ZnSe QDs was higher than that for ZnSe in bulk. PL spectra indicated an emission with three peaks related to the excitonic, surface trap states and deep level (DL) states. The band gap and QD emission were tunable only by UV illumination time during synthesis. ZnSe:Cu showed green emission due to transition of electrons from the Conduction band (CB) or surface trap states to the 2 T 2 acceptor levels of Cu 2 + . The emission was increased by increasing the Cu 2 + ion concentration, such that the optimal value of PL intensity was obtained for the nominal mole ratio of Cu:Zn 1.5%. Copyright © 2016 John Wiley & Sons, Ltd.

  16. LIPASES PRODUZIDAS POR LEVEDURAS: CATALISADORES PODEROSOS PARA APLICAÇÕES INDUSTRIAIS

    Directory of Open Access Journals (Sweden)

    Luiza Lux Lock

    2007-12-01

    Full Text Available O termo “enzimas lipolíticas” refere-se a lípases e hidrolases éster carboxílico. A produção de lipase é ampla entre as leveduras, mas poucas são capazes de produzir lipases com características interessantes e em quantidades suficientes para serem industrialmente úteis. A literatura relativa a lipases produzidas por Candida rugosa, Yarrowia (Candida lipolytica, Candida antarctica e outras leveduras produtoras de lípases é revisada. O uso de lípases recombinantes é discutido, com ênfase na utilização de sistemas de expressão heteróloga e desenho de quimeras. Finalmente, as três abordagens que visam à melhora da produção de lipase ou a modificação da seletividade do substrato da enzima (engenharia do meio, do biocatalisador e da proteína são discutidos.

  17. Theoretical and experimental studies of the ZnSe/CuInSe2 heterojunction band offset

    International Nuclear Information System (INIS)

    Nelson, A.J.; Schwerdtfeger, C.R.; Wei, S.; Zunger, A.; Rioux, D.; Patel, R.; Hoechst, H.

    1993-01-01

    We report first-principles band structure calculations that show that ZnSe/CuInSe 2 has a significant valence band offset (VBO, ΔE v ): 0.70±0.05 eV for the relaxed interface and 0.60±0.05 eV for the coherent interface. These large values demonstrate the failure of the common anion rule. This is traced to a stronger Cu,d-Se,p level repulsion in CuInSe 2 than the Zn,d-Se,p repulsion in ZnSe. The VBO was then studied by synchrotron radiation soft x-ray photoemission spectroscopy. ZnSe overlayers were sequentially grown in steps on n-type CuInSe 2 (112) single crystals at 200 degree C. In situ photoemission measurements were acquired after each growth in order to observe changes in the valence band electronic structure as well as changes in the In 4d and Zn 3d core lines. Results of these measurements reveal that the VBO is ΔE v =0.70±0.15 eV, in good agreement with the first-principles prediction

  18. Que se vea lo que se oye: a vueltas con los fonemas y las letras

    Directory of Open Access Journals (Sweden)

    Gómez del Estal Villarino, Mario

    2011-03-01

    Full Text Available Partiendo de lo que el refrán “La letra con sangre entra” viene a decir a quien se deje escucharlo, se abre una descripción de las diferencias radicales que se dan entre aprender a hablar y aprender a escribir. La relación entre ambas actividades no se puede entender sin analizar la tan extendida perversión que supone hablar lo que se escribe en vez de escribir lo que se habla. A continuación, se detallan algunos de los síntomas más frecuentes de dicha perversión, caracterizados todos por la intromisión de la conciencia en terrenos donde lo único que hace es estorbar, en especial la pronunciación pedantesca de ciertos finales silábicos o de palabra, como en traNSporte, aBStraKción, óPtico, oBjeto, fúTbol, libertaD, diGno o fraK, así como las distintas deformaciones que sufren las palabras que la ortografía académica prescribe que se escriban con la letra equis.

  19. Synthesis and properties of new CdSe-AgI-As2Se3 chalcogenide glasses

    International Nuclear Information System (INIS)

    Kassem, M.; Le Coq, D.; Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E.

    2011-01-01

    Research highlights: → Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As 2 Se 3 system. → Characterization of macroscopic properties of the new CdSe-AgI-As 2 Se 3 glasses. → Far infrared transmission of chalcogenide glasses. → Characterization of the total conductivity of CdSe-AgI-As 2 Se 3 glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As 2 Se 3 system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T g ), crystallisation (T x ), and melting (T m ) temperatures are reported and used to calculate their ΔT = T x - T g and their Hruby, H r = (T x - T g )/(T m - T x ), criteria. Evolution of the total electrical conductivity σ and the room temperature conductivity σ 298 was also studied. The terahertz transparency domain in the 50-600 cm -1 region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  20. SeP, ApoER2 and megalin as necessary factors to maintain Se homeostasis in mammals.

    Science.gov (United States)

    Krol, Magdalena Beata; Gromadzinska, Jolanta; Wasowicz, Wojciech

    2012-10-01

    Selenoprotein P (SeP) is an extracellular protein containing ten selenium atoms in the form of selenocysteine, secreted mainly from the liver. About 60% of the whole plasma selenium level is present in SeP, which makes it a useful biomarker of selenium nutritional status. The main functions of SeP are transport and storage of selenium in plasma. It is especially an important protein for the brain, testes and kidneys where the supplementation of the proper amount of Se ensures the synthesis of selenoenzymes with antioxidant properties.Recently, it has been found that SeP uptake in kidneys, testes and brain depends on the apolipoprotein receptor 2 (ApoER2) and lipoprotein megalin receptor (Lrp2). Megalin receptor represents a physiological SeP receptor in kidneys, mediating the re-uptake of secreted SeP from the primary urine. The absence of a functional megalin receptor causes a significant reduction of plasma selenium and the SeP levels as a result of Se excretion. ApoER2 is a SeP receptor in the brain and testes which uptakes Se from the extracellular fluid. Deletion of ApoER2 in mice leads to a lowered selenium level in the brain and testes, neurological dysfunction, production of abnormal spermatozoa, infertility and even death when the subjects are fed a low-selenium diet. Copyright © 2012 Elsevier GmbH. All rights reserved.

  1. Dynamical properties and their strain-dependence of ZnSe(ZnSe:N: Zinc-blende and wurtzite

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2014-06-01

    Full Text Available The lattice dynamical properties of ZnSe and ZnSe with substitutional N incorporation(ZnSe:N are investigated in both the zinc-blend(ZB and wurtzite(WZ structures using first-principles calculations. The optical phonon modes of ZB-ZnSe at the Γ-point locate at 250 cm−1 for LO and 213 cm−1 for TO. The characteristic E2 phonon modes at about 50 cm−1 and the E1 and another E2 phonon modes around 200 cm−1 of WZ-ZnSe are suggested to be the fingerprint for distinguishing the two polytypes of ZnSe. For substitutional N incorporated ZnSe, the N incorporation introduces three new high energy modes above 500 cm−1, and the splitting of them is much larger in the WZ phase than that in ZB phase. The strain dependence of phonon frequency which could be useful for corresponding spectroscopic strain characterization are also studied. The simple linear dependence is determined for ZB-ZnSe, while the situation for WZ-ZnSe looks more complicated.

  2. Estimação de parâmetros da cinética de trânsito de partículas em bovinos sob pastejo por diferentes seqüências amostrais

    Directory of Open Access Journals (Sweden)

    Detmann Edenio

    2001-01-01

    Full Text Available Objetivou-se, neste estudo, avaliar a capacidade de ajustamento de um modelo não-linear no processo de estimação dos parâmetros da cinética de trânsito de partículas de bovinos em pastejo, empregando-se diferentes seqüências de amostragem fecal. Foram utilizados cinco novilhos F1 Limousin x Nelore, fistulados no esôfago e rúmen, sob pastejo de Brachiaria decumbens, com suplementação concentrada, durante o período das águas. O experimento constituiu de três períodos experimentais, conduzido em delineamento em blocos casualizados. Empregou-se como indicador o cromo mordante, produzido a partir de amostras de extrusa. Ajustou-se às curvas de excreção fecal do indicador o modelo duplo exponencial tempo-dependente, empregando-se as seguintes seqüências amostrais: SEQ 1 - 22 coletas (seqüência amostral completa; SEQ 2 e SEQ 3 - 17 coletas (redução de pontos de coleta nas fases ascendente e descendente da curva, respectivamente; e SEQ 4 e SEQ 5 - 13 e 10 coletas fecais (redução do número de coletas em todo o perfil da curva. As seqüências reduzidas foram produzidas a partir da omissão de pontos específicos da seqüência amostral completa (SEQ 1. A comparação entre as estimativas dos parâmetros cinéticos e da excreção fecal; a análise descritiva do número de iterações necessário à convergência do modelo e do coeficiente de determinação; e a avaliação de falta de ajustamento não apontaram diferenças entre as seqüências. A análise residual apontou, contudo, melhorias quanto ao comportamento gráfico e perfil de corridas de sinal dos resíduos com a redução do número de coletas para SEQ 4 e SEQ 5. Em função de pequena perda de eficiência, avaliada frente à variância residual, observada em SEQ 5, recomenda-se o emprego de 13 coletas fecais (SEQ 4 para avaliação da curva de excreção fecal do indicador em estudos desta natureza.

  3. Sample Set (SE): SE50 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available oids We report that flavonoids with radical scavenging activity mitigate against ox...ress. These data confirm the usefulness of flavonoids for enhancing both biotic and abiotic stress tolerance...SE50 Enhancement of oxidative and drought tolerance in arabidopsis by overaccumulation of antioxidant flavon

  4. Sample Set (SE): SE52 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE52 Mass spectra-based framework for automated structural elucidation of metabolom...e data to explore phytochemical diversity A novel framework for automated elucidation of metabolite structur...te ontology system was also introduced to attain putative characterization of the metabolite signals.The automate

  5. Microstructure and thermoelectric properties of CuInSe2/In2Se3 compound

    Science.gov (United States)

    Wang, Kang; Feng, Jing; Ge, Zhen-Hua; Qin, Peng; Yu, Jie

    2018-01-01

    CuInSe2 powders were synthesized by solvothermal method, and then the CuInSe2/In2Se3 bulk samples were fabricated by spark plasma sintering (SPS) technique. To investigate the phase composition, the powders were determined by X-ray diffraction (XRD). The microstructures of the powders and bulk samples were observed by scanning electron microscopy (SEM). The transportation of the electronic properties and thermal conductivity were measured at room temperature to 700 K. According to the results, the CuInSe2 powders appeared in flower-like patterns which ranged from 3 μm to 6 μm. CuInSe2 powders were synthesized at 180∘C with a chalcopyrite structure. The Seebeck coefficient increased significantly in composite thermoelectric materials up to 200μVṡK-1 at 623 K. The thermal conductivity of the sample significantly decreases from the room temperature to 700 K. The CuInSe2 bulk composite by solvothermal method achieves the highest ZT value of 0.187 at 700 K.

  6. ORQUIECTOMIA EM BOVINOS EMPREGANDO ABRAÇADEIRA DE NÁILON NA HEMOSTASIA PREVENTIVA: EFEITO DA ESTAÇÃO DO ANO, MÉTODO DE CONTENÇÃO E TÉCNICA CIRÚRGICA USE OF NYLON TIE-WRAPS FOR PREVENTIVE HAEMOSTASIS IN BOVINE ORCHIECTOMY: INFLUENCE OF SEASON, RESTRAINT METHOD AND SURGICAL TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Jorge Luis Ferreira

    2009-04-01

    Full Text Available

    A orquiectomia pode ser praticada mediante a utilização de diferentes procedimentos cirúrgicos – método de duas incisões laterais (IL, de incisão transversal (IT e secção do funículo espermático por meio do burdizzo. Avaliaram-se o efeito da estação do ano, o método de contenção e a técnica cirúrgica sobre a recuperação de bovinos mestiços (Zebu x Europeu orquiectomizados empregando a abraçadeira de náilon na hemostasia preventiva. O estudo foi desenvolvido em uma propriedade rural, com 168 bovinos, machos, dezoito meses de idade e peso médio de 290 Kg, nos meses de maio de 2005 e janeiro de 2006. Distribuíram-se os animais em oito grupos compostos por 21 bovinos (GI, GII, GIII, GIV, GV, GVI, GVII, GVIII, para verificar as complicações pós-operátorias e a evolução clínica da cicatrização, nos dias três, 23, 43 e 63 dias após o procedimento. Conclui-se que a orquiectomia em bovinos realizada no mês de maio, mediante o emprego do método de contenção em bretes, resultou em menores índices de complicações pós-operatórias. As técnicas cirúrgicas não influenciaram na ocorrência de complicações. A abraçadeira de náilon mostrou-se eficiente na hemostasia preventiva.

    PALAVRAS-CHAVES: Abraçadeira de náilon, bovinos, castração, pós-operatório.

    Orchiectomy may be carried out through several surgical procedures, from the double lateral incision method (LI, transverse incision (TI, until the section of spermatic funnicle by burdizzo. The scope was to evaluate the effect of the season, contend method and surgical technique on the recovery of crossbred cattle (Bos indicus x Bos taurus submitted to orchiectomy, employing nylon bracers for preventive haemostasia. The study was carried out on a farm using 168 male

  7. Séries temporais e redes neurais: uma análise comparativa de técnicas na previsão de vendas do varejo brasileiro

    Directory of Open Access Journals (Sweden)

    Claudio Felisoni de Angelo

    2011-01-01

    Full Text Available Uma importante atividade econômica em qualquer sociedade diz respeito à comercialização de bens. O varejo consiste exatamente no vínculo que se estabelece entre a indústria e o consumidor final. Prever as vendas é essencial para que se possa gerenciar de modo adequado os processos produtivos e de comercialização. No varejo esse aspecto reveste-se de importância ainda maior. Vender significa harmonizar os interesses dos que produzem com aqueles que compram. Portanto, o presente trabalho tem por propósito examinar comparativamente a aplicação de dois métodos de previsão de vendas de varejo no mercado brasileiro: as séries temporais e as redes neurais. A escolha dessas duas técnicas como objeto dessa comparação foi suscitada pela importância que essas duas concepções têm assumido na literatura. Embora a utilização de redes neurais tenha proporcionado a menor soma dos quadrados dos resíduos, pode-se dizer que os resultados empregando modelos do tipo ARIMA se mostraram praticamente equivalentes.

  8. Phase diagram of the Sb-Se-I system and thermodynamic properties of SbSeI

    International Nuclear Information System (INIS)

    Aliev, Z.S.; Musaeva, S.S.; Babanly, D.M.; Shevelkov, A.V.; Babanly, M.B.

    2010-01-01

    The Sb-Se-I system was investigated by using the DTA and XRD analyses and EMF measurements with an antimony electrode. The T-x diagram of the binary Sb-I system was accurately redefined. A number of polythermal sections and the projection of the liquidus surface were constructed. The fields of the primary crystallization, as well as the types and coordinates of non- and monovariant equilibria were determined. It is shown that the quasi-binary sections Sb 2 Se 3 -SbI 3 , Sb-SbSeI, SbI 3 -Se, and SbSeI-Se triangulate the Sb-Se-I system, leading to five independent subsystems. A broad area of immiscibility, that overlaps a certain part of the antimony primary crystallization field, was found. From the EMF measurements, the partial molar functions of antimony (ΔG-bar, ΔH-bar, ΔS-bar) as well as standard integral thermodynamic functions of SbSeI were calculated. The latter were found to have the following values: ΔG f,298 0 =-80.12±1.81kJ/mol; ΔH f,298 0 =-77.3±1.8kJ/mol; S 298 0 =155.2±9.5J/(molK).

  9. Phase diagram of the Sb-Se-I system and thermodynamic properties of SbSeI

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, Z S; Musaeva, S S; Babanly, D M [Baku State University, General and Inorganic Chemistry Department (Azerbaijan); Shevelkov, A.V., E-mail: shev@inorg.chem.msu.r [Moscow Lomonosov State University, Chemistry Department (Russian Federation); Babanly, M.B., E-mail: Babanly_mb@rambler.r [Baku State University, General and Inorganic Chemistry Department (Azerbaijan)

    2010-09-03

    The Sb-Se-I system was investigated by using the DTA and XRD analyses and EMF measurements with an antimony electrode. The T-x diagram of the binary Sb-I system was accurately redefined. A number of polythermal sections and the projection of the liquidus surface were constructed. The fields of the primary crystallization, as well as the types and coordinates of non- and monovariant equilibria were determined. It is shown that the quasi-binary sections Sb{sub 2}Se{sub 3}-SbI{sub 3}, Sb-SbSeI, SbI{sub 3}-Se, and SbSeI-Se triangulate the Sb-Se-I system, leading to five independent subsystems. A broad area of immiscibility, that overlaps a certain part of the antimony primary crystallization field, was found. From the EMF measurements, the partial molar functions of antimony ({Delta}G-bar, {Delta}H-bar, {Delta}S-bar) as well as standard integral thermodynamic functions of SbSeI were calculated. The latter were found to have the following values: {Delta}G{sub f,298}{sup 0}=-80.12{+-}1.81kJ/mol; {Delta}H{sub f,298}{sup 0}=-77.3{+-}1.8kJ/mol; S{sub 298}{sup 0}=155.2{+-}9.5J/(molK).

  10. Influence of CdTe sub-monolayer stressor on CdSe quantum dot self-assembling in ZnSe

    International Nuclear Information System (INIS)

    Sedova, I.V.; Lyublinskaya, O.G.; Sorokin, S.V.; Sitnikova, A.A.; Solnyshkov, D.D.; Rykhova, O.V.; Toropov, A.A.; Ivanov, S.V.

    2006-01-01

    This paper reports on the attempt to apply the stressor-controlled quantum dot (QD) fabrication technique to the conventional CdSe/ZnSe nanostructures. Super-strained CdTe fractional monolayer (Δa/a∝14% for CdTe/ZnSe) grown on top of the Te-stabilized ZnSe surface prior to deposition of the QD material (CdSe) has been used as a stressor which is expected to affect size, composition and density of CdSe QDs. The grown structures are studied by X-ray diffraction, transmission-electron microscopy, photoluminescence (PL) and PL excitation in comparison with conventional CdSe/ZnSe QDs obtained by a modified migration enhanced epitaxy technique. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Structural and optical properties of nanocrystalline CdSe and Al:CdSe thin films for photoelectrochemical application

    Energy Technology Data Exchange (ETDEWEB)

    Gawali, Sanjay A. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004 (India); Bhosale, C.H., E-mail: bhosale_ch@yahoo.com [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004 (India)

    2011-10-03

    Highlights: {yields} The CdSe and Al:CdSe thin films have been successfully deposited by SPT. {yields} Hexagonal cubic structured CdSe and Al: CdSe thin films are observed. {yields} Large number of fine grains, Uniform and compact growth morphology. {yields} Hydrophilic surface nature. {yields} Al:CdSe have better PEC performance than CdSe. - Abstract: Nanocrystalline CdSe and Al:CdSe semiconductor thin films have been successfully synthesized onto amorphous and FTO glass substrates by spray pyrolysis technique. Aqueous solutions containing precursors of Cd and Se have been used to obtain good quality films. The optimized films have been characterized for their structural, morphological, wettability and optical properties. X-ray diffraction (XRD) studies show that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy (SEM) studies show that the film surface is smooth, uniform and compact in nature. Water wettability study reveals that the films are hydrophilic behavior. The formation of CdSe and Al:CdSe thin film were confirmed with the help of FTIR spectroscopy. UV-vis spectrophotometric measurement showed a direct allowed band gap lying in the range 1.673-1.87 eV. Output characteristics were studied by using cell configuration n- CdSe/Al:CdSe |1 M (NaOH + Na{sub 2} + S)|C. An efficient solar cell having a power conversion efficiency of 0.38% at illumination 25 mW cm{sup -2} was fabricated.

  12. Señas Mexicano

    Directory of Open Access Journals (Sweden)

    Juan F. García Mejía

    2007-01-01

    Full Text Available En este artículo se muestra un sistema que permite el estudio y práctica del Lenguaje de Señas Mexicano (LMS, el cual es el método de comunicación de las personas que padecen un trastorno de procesamiento auditivo. El sistema propuesto en este artículo consta de un guante de tela instrumentado con sensores de flexión, una etapa de acondicionamiento de señales y una tarjeta de adquisición de datos; que en su conjunto constituyen el Hardware. El software esta formado por un programa de adquisición de datos y una interfaz de usuario, ambos codificados en Visual Basic Net. El sistema propuesto se modela por medio del lenguaje de modelado unificado (UML, ya que Visual Basic es un lenguaje orientado a eventos.

  13. Sample Set (SE): SE27 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE27 Effect of agricultural films for cabbage leaf metabolites Investigation of Bra...ssica oleracea var. capitata YR Tenkuu leaf metabolites. 3 growth conditions (covered with normal or UV cut agricultura...l film or no agricultural film), 3 replicates data are examined. Takeshi Ara 1, Naoki Yamamoto 1,

  14. Aplicação aérea e terrestre de fungicida para o controle de doenças do milho Aerial and ground fungicide application to corn for disease control

    Directory of Open Access Journals (Sweden)

    João Paulo Arantes Rodrigues da Cunha

    2010-09-01

    Full Text Available O presente trabalho teve como objetivo avaliar o efeito da aplicação aérea e terrestre de fungicida no controle de doenças do milho e na deposição de calda sobre a cultura. Realizou-se a semeadura do híbrido AG7010, avaliando-se após a aplicação do fungicida (piraclostrobina + epoxiconazol, no estádio fenológico V8 a V10, a deposição de calda na parte inferior, média e superior do dossel da cultura, a severidade de doenças e a produtividade. A aplicação aérea foi realizada com volumes de calda de 15 e 30 L ha-1, empregando pontas de jato plano, e a aplicação terrestre com 100 L ha-1, empregando pontas de jato plano defletor com indução de ar e pontas de jato plano defletor duplo. Como testemunha foi utilizado um tratamento sem o recebimento de fungicida. O estudo da deposição foi realizado com o emprego de papéis hidrossensíveis. Concluiu-se que os tratamentos terrestres apresentaram maior densidade de gotas no dossel da cultura do milho, mas todos os tratamentos proporcionaram a deposição mínima recomendada para aplicação de fungicida. A aplicação aérea empregando volume de calda de 30 L ha-1 proporcionou produtividade semelhante aos tratamentos terrestres, mostrando ser viável tecnicamente sua utilização.This study aimed to evaluate the effect of the aerial and ground application of fungicide in the control of corn diseases and in the spray deposition on the canopy. The hybrid AG7010 was sown and the spray deposition on the bottom, middle and upper canopy of the crop, disease severity and yield were evaluated after the application of the fungicide (pyraclostrobin + epoxiconazol, at the V8 -V10 stage. The aerial application was accomplished with spray volumes of 15 and 30 L ha-1, using flat-fan spray nozzles, and the ground one with 100 L ha-1, using turbo twin flat-fan and air induction turbo flat-fan spray nozzles. An additional treatment that received no fungicide was also evaluated. The study of the

  15. Antiphase Boundaries in the Turbostratically Disordered Misfit Compound (BiSe)(1+δ)NbSe2.

    Science.gov (United States)

    Mitchson, Gavin; Falmbigl, Matthias; Ditto, Jeffrey; Johnson, David C

    2015-11-02

    (BiSe)(1+δ)NbSe2 ferecrystals were synthesized in order to determine whether structural modulation in BiSe layers, characterized by periodic antiphase boundaries and Bi-Bi bonding, occurs. Specular X-ray diffraction revealed the formation of the desired compound with a c-axis lattice parameter of 1.21 nm from precursors with a range of initial compositions and initial periodicities. In-plane X-ray diffraction scans could be indexed as hk0 reflections of the constituents, with a rectangular basal BiSe lattice and a trigonal basal NbSe2 lattice. Electron micrographs showed extensive turbostratic disorder in the samples and the presence of periodic antiphase boundaries (approximately 1.5 nm periodicity) in BiSe layers oriented with the [110] direction parallel to the zone axis of the microscope. This indicates that the structural modulation in the BiSe layers is not due to coherency strain resulting from commensurate in-plane lattices. Electrical transport measurements indicate that holes are the dominant charge carrying species, that there is a weak decrease in resistivity as temperature decreases, and that minimal charge transfer occurs from the BiSe to NbSe2 layers. This is consistent with the lack of charge transfer from the BiX to the TX2 layers reported in misfit layer compounds where antiphase boundaries were observed. This suggests that electronic considerations, i.e., localization of electrons in the Bi-Bi pairs at the antiphase boundaries, play a dominant role in stabilizing the structural modulation.

  16. COMPACTAÇÃO DE SOLOS EM LABORATÓRIO: EFEITO DO DIÂMETRO E DO NÚMERO DE CAMADAS DO CORPO DE PROVA

    Directory of Open Access Journals (Sweden)

    Flavio Alessandro Crispim

    2015-06-01

    Full Text Available RESUMONeste trabalho, estudou-se a influência do diâmetro e do número de camadas do corpo de prova nas curvas de compactação de laboratório e na resistência mecânica de dois solos residuais de gnaisse da Zona da Mata Norte de Minas Gerais, respectivamente, de texturas argilo-areno-siltosa (Solo 1 e areno-silto-argilosa (Solo 2, com vistas à construção de estradas florestais. Além dos resultados dos ensaios de compactação, determinou-se a resistência à compressão não confinada dos solos empregando corpos de prova compactados na umidade ótima (wot e nos teores de umidade 3% abaixo e 2% acima, considerando como referência a energia de compactação do ensaio Proctor normal e empregando corpos de prova compactados em uma, duas e três camadas, bem como nos diâmetros de 35 mm, 73 mm e 100 mm, com nove repetições. Para fins práticos de engenharia e com base em análise estatística aplicada aos parâmetros massa específica aparente seca e resistência à compressão não confinada, pode-se concluir que: (i há diferenças significativas entre as compactações realizadas em uma e em três camadas, não ocorrendo o mesmo nas compactações realizadas em duas e em três camadas, para ambos os solos; e (ii há diferenças significativas entre a compactação de corpos de prova de diâmetro 100 mm e os demais de 73 mm e 35 mm, para o solo 1 (argiloso, bem como há também diferenças apenas no ramo seco da curva de compactação, para o solo 2 (arenoso.

  17. Notas sobre a contribuição do desenho industrial á arquitetura e a cidade

    Directory of Open Access Journals (Sweden)

    Alessandro Ventura

    2000-06-01

    Full Text Available A principal preocupação do texto é discutir o uso de técnicas industriais pela arquitetura e refletir sobre suas repercussões na cidade. Nesta discussão procura-se estabelecer uma relação entre as técnicas de projeto do desenho industrial e da arquitetura, focalizando-a dentro de uma forma de pensamento produtivo típico da indústria. Abordamos a idéia de produção na cidade, procurando mostrar que seu desenho é fruto dos produtos que lhe são impostos e não por aqueles gerados por suas necessidades. Discorremos, assim, sobre a influência dos veículos automotores no desenho das cidades e sobre a necessidade de criar limitações a seu uso urbano. Alguns dados sobre a importância da indústria da construção são levantados, comparando-a à vitalidade e à relativa importância da indústria automobilística. Finalizamos abordando o tema da mobilidade, característica típica dos produtos industriais. Esta mobilidade construtiva pode vir a ser um elemento fundamental de inovação urbana e transformar a cidade em fruto de sua própria produção

  18. Heterojunctions formed by annealing of GaSe and InSe layered crystals in zinc vapor

    Directory of Open Access Journals (Sweden)

    Kudrynskyi Z. R.

    2012-12-01

    Full Text Available The article presents a method of creating heterojunc¬tions based on semiconductors with different lattice types. Substrates manufactured from GaSe and InSe layered crystals were annealed in Zn vapor. This way, n-ZnSe–p-GaSe and n-ZnSe–p-InSe heterojunctions were obtained. The obtained heterojunctions are photo¬sensitive in near and infrared spectral regions. This method opens up greate possibilities of producing heterostructures with a desired sensitivity band.

  19. Thermoelectric study of Ag doped SnSe-Sb2Se3 based alloy

    Science.gov (United States)

    Das, Anish; Talukdar, M.; Kumar, Aparabal; Sarkar, Kalyan Jyoti; Dhama, P.; Banerji, P.

    2018-05-01

    In this article we have synthesized p-type alloy of SnSe and Sb2Se3 (10 atomic %) to study the thermoelectric transport properties. The alloy was prepared by melt grown technique followed by spark plasma sintering and latter doped with 2 atomic % Ag to compensate the carrier density in order to achieve higher electrical conductivity (σ). Out of these, the doped sample resulted in the maximum figure of merit, ZT˜0.7 at 773 K due to the existence of the secondary phase AgSbSe2 and reduced lattice thermal conductivity (0.61 W m-1 K-1 at 300 K). The fitted lattice thermal conductivity shows that point defect and Umklapp scattering are the primary process of phonon scattering for all the samples whereas the fitted mobility data confirms acoustic phonon scattering along with point defect and grain boundary scattering to be the main carrier scattering mechanism. More over room temperature carrier density and electrical conductivity are found to increase for the doped sample which further corroborate (90%)SnSe-(10%)Sb2Se3:2%Ag to be a potential candidate for highly efficient thermoelectric materials.

  20. Optical properties of thermally annealed CdZnSe/ZnSe quantum dots

    International Nuclear Information System (INIS)

    Margapoti, Emanuela

    2010-01-01

    To analyse the diffusion characteristics, photoluminescence (PL) spectroscopy has been carried out in extensive detail on single, as well as, ensembles of thermally annealed (TA) CdSe/ZnSe QDs. For a series of QD-ensembles, each annealed for t A = 30 s at temperatures from T A = 300-550 C, the change in the QD-composition has been calculated from the blue-shift of the exciton ground-state PL-emission, using a concentration function based on Fick's laws of diffusion. The diffusion length (L D ) and the activation energy (E A ) have been determined thereof. For the studied QDs, E A has been evaluated to be 2.2 eV. Additionally, TA results also in an enhancement of the PL-intensity and reduction of the full-width-at-half maximum (FWHM) of the spectra. This point towards an increased homogeneity of the QD-size and composition, and decrease in the concentration of defects around the QDs. For single CdSe/ZnSe QDs, TA has been varied from 100-240 C, in steps for 20 C, with t A kept fixed at 30 s. Finally, the evolution of the magneto-optic response with post-growth thermal annealing has been studied for both individual QDs and QD-ensembles. An external magnetic field, applied perpendicular to the plane of the QDs (Faraday configuration), results in Zeeman spin splitting of the ground exciton state. The emissions from the Zeeman-split states are left and right circularly polarized and from the degree of circular polarization (DCP), as well as, the spectral separation of the PL-peaks, the g-factor can be estimated. For CdSe/ZnSe QD-ensembles, the g-factor has been observed to change sign with TA. (orig.).

  1. Optical properties of thermally annealed CdZnSe/ZnSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Margapoti, Emanuela

    2010-07-01

    To analyse the diffusion characteristics, photoluminescence (PL) spectroscopy has been carried out in extensive detail on single, as well as, ensembles of thermally annealed (TA) CdSe/ZnSe QDs. For a series of QD-ensembles, each annealed for t{sub A} = 30 s at temperatures from T{sub A} = 300-550 C, the change in the QD-composition has been calculated from the blue-shift of the exciton ground-state PL-emission, using a concentration function based on Fick's laws of diffusion. The diffusion length (L{sub D}) and the activation energy (E{sub A}) have been determined thereof. For the studied QDs, E{sub A} has been evaluated to be 2.2 eV. Additionally, TA results also in an enhancement of the PL-intensity and reduction of the full-width-at-half maximum (FWHM) of the spectra. This point towards an increased homogeneity of the QD-size and composition, and decrease in the concentration of defects around the QDs. For single CdSe/ZnSe QDs, TA has been varied from 100-240 C, in steps for 20 C, with t{sub A} kept fixed at 30 s. Finally, the evolution of the magneto-optic response with post-growth thermal annealing has been studied for both individual QDs and QD-ensembles. An external magnetic field, applied perpendicular to the plane of the QDs (Faraday configuration), results in Zeeman spin splitting of the ground exciton state. The emissions from the Zeeman-split states are left and right circularly polarized and from the degree of circular polarization (DCP), as well as, the spectral separation of the PL-peaks, the g-factor can be estimated. For CdSe/ZnSe QD-ensembles, the g-factor has been observed to change sign with TA. (orig.).

  2. Thermally stimulated properties in ZnSe:Tb and ZnSe:(Mn, Tb) phosphors

    Science.gov (United States)

    Mishra, A. K.; Mishra, S. K.; Pandey, S. P.; Lakshmi Mishra, Kshama

    2018-02-01

    Thermoluminescence studies were performed of ZnSe:Tb and ZnSe:(Mn, Tb) phosphors. A method of preparation for ZnSe phosphors doped with Tb and (Mn, Tb) has been discussed. The thermoluminescence (TL) properties of these phosphors have been studied from 100 to 370 K temperature after exciting by UV radiation (365 nm) at three uniform heating rates 0.4, 0.6 and 0.9 K/s. The trapping parameters like trap depth, lifetime of electrons and capture cross-section have also been determined using various methods.

  3. Ab initio phonon thermal transport in monolayer InSe, GaSe, GaS, and alloys

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Tribhuwan; Parker, David S.; Lindsay, Lucas

    2017-10-17

    We compare vibrational properties and phonon thermal conductivities (κ) of monolayer InSe, GaSe and GaS systems using density functional theory and Peierls-Boltzmann transport methods. In going from InSe to GaSe to GaS, system mass decreases giving both increasing acoustic phonon velocities and decreasing scattering of these heat-carrying modes with optic phonons, ultimately giving κInSe< κGaSe< κGaS. This behavior is demonstrated by correlating the scattering phase space limited by fundamental conservation conditions with mode scattering rates and phonon dispersions for each material. We also show that, unlike flat monolayer systems such as graphene, thermal transport is governed by in-plane vibrations in InSe, GaSe and GaS, similar to buckled monolayer materials such as silicene. Alloying of InSe, GaSe and GaS systems provides an effective method for modulating their κ through intrinsic vibrational modifications and phonon scattering from mass disorder giving reductions ~2-3.5 times. This disorder also suppresses phonon mean free paths in the alloy systems compared to those in their crystalline counterparts. This work provides fundamental insights of lattice thermal transport from basic vibrational properties for an interesting set of two-dimensional materials.

  4. Sample Set (SE): SE59 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available idopsis thaliana (Arabidopsis). However, the behavior of flavonoids during drough...t stress is still not well documented. Herein we investigated the time-series alternation of flavonoids in t...vonoids, a class of specialized metabolites, including flavonols and anthocyanins w...SE59 Alternation of flavonoid accumulation under drought stress in Arabidopsis thaliana We reported that fla

  5. Intercalation compounds of NbSe2 und SnSe2. Model systems for low-dimensional superconductors

    International Nuclear Information System (INIS)

    Herzinger, Michael

    2013-01-01

    Quasi-two-dimensional (2D) metal dichalcogenides have received considerable research interest since their complex anisotropic electronic properties can be controlled by the intercalation of donor species. Although layered dichalcogenides have been studied by many aspects of chemical and physical properties, their two-dimensional character is only poorly understood. The present work deals with the layer-shaped dichalcogenides SnSe 2 and NbSe 2 . The host-material SnSe 2 was synthesized by chemical transport with Iodine as transport agent in sealed quartz ampoules. The intercalation of the semiconducting layered single crystals SnSe 2 with the organometallic compound cobaltocene (CoCp 2 ) leads to superconductivity up to T = 8 K. Ex-situ intercalation studies show an intercalation-mechanism outgoing from the host material 2H-SnSe 2 in a stage-2 phase which goes over in a stage-1 phase for higher intercalation degrees. In addition, SnSe 2 {CoCp 2 } x show remarkable low-temperature properties e.g. the coexistence of superconductivity and magnetism in dependence of the staging and cobaltocene-content of the material. Starting from an intercalation degree of 17% CoCp 2 long range ordered magnetism (with increasing saturation magnetization) was observed in 18R-SnSe 2 {CoCp 2 } x . Furthermore SnSe 2 {CoCp 2 } x show an extremely sensitive superconducting pinning behavior in very small magnetic fields partially below B 2 -content. A phase diagram was developed in dependence of the degree of intercalation over the whole range of intercalation between 0 % and 33 %. For comparison of the low-temperature character of SnSe 2 {CoCp 2 } x , another layer-shaped superconductor NbSe 2 was intercalated with CoCp 2 . The layered high-k s-wave superconductor 2H-NbSe 2 belongs to the most prominent low-dimensional materials studied during the past fifty years. After the discovery of the high temperature superconductor MgB 2 , a benchmark system for multi-band superconductivity, NbSe 2

  6. IR and Raman spectra of LaH(SeO3)2 and FeH(SeO3)2

    International Nuclear Information System (INIS)

    Ratheesh, R.; Suresh, G.; Nayar, V.U.; Morris, R.E.

    1995-01-01

    The infrared and Raman spectra of LaH(SeO 3 ) 2 and FeH(SeO 3 ) 2 crystals are recorded and analysed. Bands confirm the coexistence of HSeO 3 - and SeO 3 2- ions in both LaH(SeO 3 ) 2 and FeH(SeO 3 ) 2 crystals. The Se-OH stretching vibrations are observed to be at lower wavenumbers in LaH(SeO 3 ) 2 than that in the iron compound in agreement with the short O-O distance in the former. Observed bands indicate that the SeO 3 2- ions are more angularly distorted in FeH(SeO 3 ) 2 crystal. ABC bands, characteristic of strong hydrogen bonded systems are observed in the infrared spectra of both the crystals. (author). 15 refs., 2 figs., 1 tab

  7. Simultaneous speciation of arsenic (As(III), MMA, DMA, and As(V)) and selenium (Se(IV), Se(VI), and SeCN{sup -}) in petroleum refinery aqueous streams

    Energy Technology Data Exchange (ETDEWEB)

    Tonietto, Gisele B.; Godoy, Jose M.; Oliveira, Ana Cristina [Pontificia Universidade Catolica do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Souza, Marcia V. de [Petrobras/Cenpes, Research and Development Center, Rio de Janeiro (Brazil)

    2010-07-15

    High-performance liquid chromatography (HPLC) coupled to an ICP-MS with an octapole reaction system (ORS) has been used to carry out quantitative speciation of selenium (Se) and arsenic (As) in the stream waters of a refining process. The argon dimers interfering with the {sup 78}Se and {sup 80}Se isotopes were suppressed by pressurizing the octapole chamber with 3.1 mL min{sup -1} H{sub 2} and 0.5 mL min{sup -1} He. Four arsenic species arsenite - As(III), arsenate (As(V)), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) - and three inorganic Se species - selenite Se(IV), selenate Se(VI), and selenocyanate (SeCN{sup -}) - were separated in a single run by ion chromatography (IC) using gradient elution with 100 mmol L{sup -1} NH{sub 4}NO{sub 3}, pH 8.5, adjusted by addition of NH{sub 3}, as eluent. Repeatabilities of peak position and of peak area evaluation were better than 1% and about 3%, respectively. Detection limits (as 3{sigma} of the baseline noise) were 81, 56, and 75 ng L{sup -1} for Se(IV), Se(VI), and SeCN{sup -}, respectively, and 22, 19, 25, and 16 ng L{sup -1} for As(III), As(V), MMA, and DMA, respectively. Calibration curve R {sup 2} values ranged between 0.996 and 0.999 for the arsenic and selenium species. Column recovery for ion chromatography was calculated to be 97 {+-} 6% for combined arsenic species and 98 {+-} 3% for combined selenium species. Because certified reference materials for As and Se speciation studies are still not commercially available, in order to check accuracy and precision the method was applied to certified reference materials, BCR 714, BCR 1714, and BCR 715 and to two different refinery samples - inlet and outlet wastewater. The method was successfully used to study the quantitative speciation of selenium and arsenic in petroleum refinery wastewaters. (orig.)

  8. Third-order nonlinear optical properties of GeSe2-Ga2Se3-PbI2 glasses

    International Nuclear Information System (INIS)

    Tang Gao; Liu Cunming; Luo Lan; Chen Wei

    2010-01-01

    The third-order nonlinear optical (NLO) properties of new selenium-based GeSe 2 -Ga 2 Se 3 -PbI 2 glasses have been measured using the optical Kerr effect (OKE) technique, with picosecond and femtosecond laser pulses. The 0.70GeSe 2 -0.15Ga 2 Se 3 -0.15PbI 2 glass has the largest third-order optical nonlinear susceptibility in GeSe 2 -Ga 2 Se 3 -PbI 2 glass system with χ (3) of 5.28x10 12 esu. In addition, the response time of glasses is sub-picosecond, which is predominantly associated with electron cloud. Local structure of the glasses has been identified by using Raman studies, while the origins of the observed nonlinear optical response are discussed. The [Ge(Ga)Se 4 ] tetrahedral and lone-pair electrons from highly polarizable Pb atom in glasses play an important role in enhanced NLO response. These results as well as their good chemical stability indicate that GeSe 2 -Ga 2 Se 3 -PbI 2 glasses are promising materials for photonic applications of third-order nonlinear optical signal processing.

  9. Remoção e concentração de urânio de rejeito de mina

    Directory of Open Access Journals (Sweden)

    Elizângela Augusta Santos

    2011-01-01

    Full Text Available A utilização de agentes lixiviantes como citrato de sódio e carbonato de amônio foram estudados para a recuperação de urânio (U de um rejeito de mina. Técnicas de concentração como precipitação e troca iônica foram avaliadas. O rejeito estudado apresenta 0,25% de U. Resultados mostraram extração máxima de aproximadamente 40% para ambos os reagentes. 62% de U foram precipitados do licor da lixiviação empregando-se solução a 10 mol L-1 de NaOH. Os carregamentos máximos do metal obtidos a pH 3,9 apontaram uma maior capacidade de remoção empregando-se a resina IRA 910 U cujo valor de carregamento máximo foi de 126,9 mg g-1 e de 148,3 mg g-1 para a DOWEX RPU.Abstract The use of leaching agents, such as sodium citrateand ammonium carbonate, were assessed for the extraction ofuranium from one mining residue containing 0.25% U.Concentration techniques such as precipitation and ion exchangewere employed to recover the uranium from the leaching liquor.Leaching results showed maximum uranium extraction of about 40% for both reagents. The use 10 mol L-1 NaOH to precipitatethe uranium from the leach liquor leads to a recovery of 62%;what was considered not satisfactory. In view of this, resins wereused to concentrate the uranium from the liquor and the metalloading obtained at pH 3.9 was higher for the resin DOWEXRPU, whose maximum loading maximum capacity was148,3 mg g-1, compared to 126,9 mg g-1 presented by the resinIRA 910 U.

  10. Estimativa da evapotranspiração e coeficiente de cultivo da Heliconia bihai L., cultivada em ambiente protegido.

    Directory of Open Access Journals (Sweden)

    Rubens Sonsol Gondim

    2008-07-01

    Full Text Available O trabalho foi desenvolvido em ambiente protegido, do tipo telado, no Campo Experimental do Curu, região litorânea do Estado do Ceará, e teve como objetivo estimar a evapotranspiração e os coeficientes de cultivo da Heliconia bihai L. empregando o método do balanço hídrico e a vapotranspiração de referência (ETo estimada pelo método de Penman-Monteith-FAO e tanque Classe A. Utilizou-se na cultura o espaçamento de 2,00 m entre fileiras por 1,00 m entre plantas e irrigação por microaspersão. A taxa média de ETc foi de 2,3 mm dia-1, totalizando 174,7 mm para todo o período. Com relação às fases fenológicas da cultura, observou-se uma ETc 2,2 mm dia-1 durante a fase F2 (10% até 80% de cobertura vegetal; 2,3 mm dia-1 na fase F3 (80% de cobertura até o inicio da floração e 2,5 mm dia-1 na fase F4 (início da floração até a colheita. Os valores de coeficientes de cultivo (Kc foram maiores quando a ETo foi estimada pelo tanque Classe A, em relação aos valores da ETo estimados pelo método de Penman-Monteith-FAO. Empregando o primeiro método, os valores de Kc foram 0,80; 1,20 e 1,20, enquanto para Penman-Monteith-FAO foram 0,60; 0,80 e 0,80, nas fases F2; F3 e F4, espectivamente.

  11. Determinação simultânea dos teores de cinza e proteína em farinha de trigo empregando NIRR-PLS e DRIFT-PLS Simultaneous determination of ash content and protein in wheat flour using infrared reflection techniques and partial least-squares regression (PLS

    Directory of Open Access Journals (Sweden)

    Marco Flôres Ferrão

    2004-09-01

    Full Text Available As técnicas de espectroscopia por reflexão no infravermelho próximo (NIRRS e por reflexão difusa no infravermelho médio com transformada de Fourier (DRIFTS foram empregadas com o método de regressão multivariado por mínimos quadrados parciais (PLS para a determinação simultânea dos teores de proteína e cinza em amostras de farinha de trigo da variedade Triticum aestivum L. Foram coletados espectros no infravermelho em duplicata de 100 amostras, empregando-se acessórios de reflexão difusa. Os teores de proteína (8,85-13,23% e cinza (0,330-1,287%, empregados como referência, foram determinados pelo método Kjeldhal e método gravimétrico, respectivamente. Os dados espectrais foram utilizados no formato log(1/R, bem como suas derivadas de primeira e segunda ordem, sendo pré-processados usando-se os dados centrados na média (MC ou escalados pela variância (VS ou ambos. Cinqüenta e cinco amostras foram usadas para calibração e 45 para validação dos modelos, adotando-se como critério de construção os valores mínimos do erro padrão de calibração (SEC e do erro padrão de validação (SEV. Estes valores foram inferiores a 0,33% para proteína e a 0,07% para cinza. Os métodos desenvolvidos apresentam como vantagens a não agressão ao ambiente, bem como permitem uma determinação direta, simultânea, rápida e não destrutiva dos teores de proteína e cinza em amostras de farinha de trigo.Partial Least Square (PLS multivariate calibration associated to Near Infrared Reflection Spectroscopy (NIRRS or Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS were used to establish methods for simultaneous determination of protein and ash content on commercial wheat flour samples of Triticum aestivum L. Duplicate spectra of 100 samples with protein content between 8.85-13.23% (Kjeldahl method and ash content between 0.330-1.287% (gravimetric method were employed to build calibration methods. The spectra were used

  12. Trade unions and the economic performance of brazilian establishments

    Directory of Open Access Journals (Sweden)

    Naércio Aquino Menezes-Filho

    2008-03-01

    Full Text Available This paper examines, for the first time in the literature, the impact of trade unions on various performance indicators of Brazilian establishments. A unionism retrospective survey was carried out among 1,000 establishments in the manufacturing sector and its results were matched to performance indicators available from the Brazilian Industrial Surveys between 1990 and 2000. The results using the pooled data indicate that the relationship between unionism and some performance indicators, such as average wages, employment and productivity is non-linear (concave, so that a rise in unionism from low levels is associated with higher performance, but at a decreasing rate. Unions also reduce profitability. Establishments that introduced profit-sharing schemes increased their productivity and profitability overall and paid higher wages in more unionized plants.Este artigo analisa, pela primeira vez na literatura, o impacto dos sindicatos de trabalhadores em vários indicadores de desempenho econômico de firmas industriais brasileiras. Realizou-se uma pesquisa retrospectiva sobre a densidade sindical de 1000 estabelecimentos industriais brasileiros e seus resultados foram combinados aos indicadores de desempenho econômico da Pesquisa Industrial Anual (PIA de 1990 a 2000. Os resultados indicam que a relação entre a densidade sindical na firma e seus salários, emprego e produtividade, é não-linear, ou seja, um aumento no grau de sindicalização leva a um melhor desempenho, porém a taxas decrescentes. Observou-se, também, uma relação negativa entre sindicalização e rentabilidade. Finalmente, estabelecimentos que introduziram mecanismos de 'participação nos lucros' aumentaram sua produtividade e rentabilidade no período e pagaram maiores salários nas firmas onde o grau de sindicalização era maior.

  13. Enhancement of hole mobility in InSe monolayer via an InSe and black phosphorus heterostructure.

    Science.gov (United States)

    Ding, Yi-Min; Shi, Jun-Jie; Xia, Congxin; Zhang, Min; Du, Juan; Huang, Pu; Wu, Meng; Wang, Hui; Cen, Yu-Lang; Pan, Shu-Hang

    2017-10-05

    To enhance the low hole mobility (∼40 cm 2 V -1 s -1 ) of InSe monolayer, a novel two-dimensional (2D) van der Waals heterostructure made of InSe and black phosphorus (BP) monolayers with high hole mobility (∼10 3 cm 2 V -1 s -1 ) has been constructed and its structural and electronic properties are investigated using first-principles calculations. We find that the InSe/BP heterostructure exhibits a direct band gap of 1.39 eV and type-II band alignment with electrons (holes) located in the InSe (BP) layer. The band offsets of InSe and BP are 0.78 eV for the conduction band minimum and 0.86 eV for the valence band maximum, respectively. Surprisingly, the hole mobility in the InSe/BP heterostructure exceeds 10 4 cm 2 V -1 s -1 , which is one order of magnitude larger than the hole mobility of BP and three orders larger than that of the InSe monolayer. The electron mobility is also increased to 3 × 10 3 cm 2 V -1 s -1 . The physical reason has been analyzed deeply, and a universal method is proposed to improve the carrier mobility of 2D materials by forming heterostructures with them and other 2D materials with complementary properties. The InSe/BP heterostructure can thus be widely used in nanoscale InSe-based field-effect transistors, photodetectors and photovoltaic devices due to its type-II band alignment and high carrier mobility.

  14. Complexing in (NH4)2SeO4-UO2SeO4 H2O system

    International Nuclear Information System (INIS)

    Serezhkina, L.B.

    1994-01-01

    Isotherm of solubility in the (NH 4 ) 2 SeO 4 -UO 2 SeO 4 -H 2 O system has been constructed at 25 deg C. (NH 4 ) 2 (UO 2 ) 2 (SeO 4 ) 3 x6H 2 O formation is established for the first time and certain its physicochemical properties are determined. Regularities of complexing in the R 2 Se) 4 -UO 2 SeO 4 -H 2 O systems, where R-univalent cation are under discussion. 6 refs.; 3 tabs

  15. Flexible one-dimensional carbon-selenium composite nanofibers with superior electrochemical performance for Li-Se/Na-Se batteries

    Science.gov (United States)

    Zeng, Linchao; Wei, Xiang; Wang, Jiaqing; Jiang, Yu; Li, Weihan; Yu, Yan

    2015-05-01

    A facile strategy is developed to synthesis selenium/carbon composites (Se@CNFs-CNT) by co-heating Se powder and electrospun Polyacrylonitrile (PAN)-CNT nanofibers at 600°Cin a sealed vessel. The Se molecules are chemically bonded and physical encapsulated by carbonized PAN-CNT composite (CNFs-CNT), which leads to prevent the dissolution of polyselenide intermediates in carbonate based electrolyte. When directly used as flexible free-standing cathode material for Li-Se batteries in low cost carbonate-based electrolyte, the Se@CNFs-CNT electrode exhibits improved cyclability (517 mAh g-1 after 500 cycles at 0.5 A g-1) and rate capability (485 mAh g-1 at 1 A g-1). Moreover, when tested as sodium batteries, it maintains a reversible capacity of 410 mAh g-1 after 240 cycles at 0.5 A g-1. The superior electrochemical performance (especially at high rates) of Se@CNFs-CNT is attributed to synergistic effect of the additive of CNT, the well confine of Se in the CNFs-CNT matrix through chemical bonding and the 3D interconnected carbon nanofibers (CNFs). This simple yet efficient process thus provides a promising route towards fabrication of a variety of high performance flexible Li-Se and Na-Se batteries.

  16. Achieving tunable doping of MoSe2 based devices using GO@MoSe2 heterostructure

    Science.gov (United States)

    Maji, Tuhin Kumar; Tiwary, Krishna Kanhaiya; Karmakar, Debjani

    2017-05-01

    Doping nature of MoSe2, one of the promising Graphene analogous device material, can be tuned by controlling the concentration of functional groups in Graphene oxide (GO)@MoSe2 heterostructure. In this study, by first-principles simulation, we have observed that GO can be used as a carrier injection layer for MoSe2, where n or p type carriers are introduced within MoSe2 layer depending on the type and concentration of functional moieties in it. Both n and p-type Schottky barrier height modulations are investigated for different modeled configurations of the heterostructure. This combinatorial heterostructure can be a promising material for future electronic device application.

  17. Formation of a Colloidal CdSe and ZnSe Quantum Dots via a Gamma Radiolytic Technique

    Directory of Open Access Journals (Sweden)

    Aeshah Salem

    2016-09-01

    Full Text Available Colloidal cadmium selenide (CdSe and zinc selenide (ZnSe quantum dots with a hexagonal structure were synthesized by irradiating an aqueous solution containing metal precursors, poly (vinyl pyrrolidone, isopropyl alcohol, and organic solvents with 1.25-MeV gamma rays at a dose of 120 kGy. The radiolytic processes occurring in water result in the nucleation of particles, which leads to the growth of the quantum dots. The physical properties of the CdSe and ZnSe nanoparticles were measured by various characterization techniques. X-ray diffraction (XRD was used to confirm the nanocrystalline structure, energy-dispersive X-ray spectroscopy (EDX was used to estimate the material composition of the samples, transmission electron microscopy (TEM was used to determine the morphologies and average particle size distribution, and UV-visible spectroscopy was used to measure the optical absorption spectra, from which the band gap of the CdSe and ZnSe nanoparticles could be deduced.

  18. TEMPO E FILOSOFIA NO ROMANCE "PEDRO PÁRAMO", DE JUÁN RULFO

    Directory of Open Access Journals (Sweden)

    Profª Drª Cláudia Falluh Balduino Ferreira

    2012-01-01

    Full Text Available Considerando que a questão filosófica expressa pela composição narrativa visa às relações e as tensões entre o tempo da narrativa e o da vida, e que várias disciplinas são convocadas a este amplo debate, o presente artigo quer ilustrar ao modo como se dão a aliança entre os processos mnemônicos e de anamnese e a experiência do tempo no romance do escritor mexicano Ruan Rulfo, empregando as noções filosóficas de anamnese conforme Platão e a questão do temporal segundo Paul Ricoeur.

  19. Identification of Lactobacillus UFV H2b20 (probiotic strain using DNA-DNA hybridization Identificação de Lactobacillus UFV H2b20 (linhagem probiótica através de hibridização DNA-DNA

    Directory of Open Access Journals (Sweden)

    J.T. de Magalhães

    2008-09-01

    Full Text Available Sequence analyses of the 16S rDNA gene and DNA-DNA hybridization tests were performed for identification of the species of the probiotic Lactobacillus UFV H2b20 strain. Using these two tests, we concluded that this strain, originally considered Lact. acidophilus, should be classified as Lact. delbrueckii.Análise da seqüência do gene 16S rDNA e ensaios de hibridização DNA_DNA foram empregados para identificar a espécie da cepa probiótica Lactobacillus UFV H2b20. Empregando-se estes dois testes, concluímos que esta cepa, originalmente considerada Lact. acidophilus, deve ser classificada como Lact. delbrueckii.

  20. Pirólise rápida de casca de arroz: estudo de parâmetros e caracterização de produtos

    OpenAIRE

    Suelen Rodrigues Almeida

    2010-01-01

    A pirólise (aquecimento em atmosfera inerte) é uma das formas de aproveitamento dos resíduos da agroindústria, gerando o bio-óleo (produto condensável), gases e resíduo sólido (sílico-carbonoso) com utilidades diversas, tanto para fins energéticos como outras utilizações industriais. Neste trabalho estudou-se a pirólise rápida da casca de arroz usando um forno tubular e um reator de leito fixo. Após otimização do processo de pirólise (7 g de casca de arroz moída, pirolisada a 700ºC com uma ta...

  1. Desenvolvimento de controle avançado para processos de aeração por ar difuso visando aplicação em sistemas de tratamento de efluentes

    OpenAIRE

    Tiago Magalhães Soares

    2010-01-01

    Sistemas de aeração são amplamente utilizados em estações de tratamento de esgotos sanitários e efluentes industriais, sendo a configuração mais utilizada os sistemas de lodos ativados. Neste trabalho, buscou-se a implementação e o teste de uma estratégia de controle avançado em um sistema de aeração. Foi utilizado um canal de aeração com recirculação de água como simulação de um tanque de aeração. Para consumir o oxigênio dissolvido na água, foi realizada a dosagem de hipossulfito de sódio n...

  2. Dipole strength in 80Se below the neutron-separation energy for the nuclear transmutation of 79Se

    Directory of Open Access Journals (Sweden)

    Makinaga Ayano

    2017-01-01

    Full Text Available The γ-ray strength function (γSF in 80Se is an important parameter to estimate the neutron-capture cross section of 79Se which is one of the long-lived fission products (LLFPs. Until now, the γSF method was applied for 80Se only above the neutron-separation energy (Sn and the evaluated 79Se(n,γ cross section has an instability caused by the GSF below Sn. We studied the dipole-strength distribution of 80Se in a photon-scattering experiment using bremsstrahlung produced by an electron beam of an energy of 11.5 MeV at the linear accelerator ELBE at HZDR. The present photoabsorption cross section of 80Se was combined with results of (γ,n experiments and are compared with predictions usinmg the TALYS code. We also estimated the 79Se(n,γ cross sections and compare them with TALYS predictionms and earlier work by other groups.

  3. Dipole strength in 80Se below the neutron-separation energy for the nuclear transmutation of 79Se

    Science.gov (United States)

    Makinaga, Ayano; Massarczyk, Ralph; Beard, Mary; Schwengner, Ronald; Otsu, Hideaki; Müller, Stefan; Röder, Marko; Schmidt, Konrad; Wagner, Andreas

    2017-09-01

    The γ-ray strength function (γSF) in 80Se is an important parameter to estimate the neutron-capture cross section of 79Se which is one of the long-lived fission products (LLFPs). Until now, the γSF method was applied for 80Se only above the neutron-separation energy (Sn) and the evaluated 79Se(n,γ) cross section has an instability caused by the GSF below Sn. We studied the dipole-strength distribution of 80Se in a photon-scattering experiment using bremsstrahlung produced by an electron beam of an energy of 11.5 MeV at the linear accelerator ELBE at HZDR. The present photoabsorption cross section of 80Se was combined with results of (γ,n) experiments and are compared with predictions usinmg the TALYS code. We also estimated the 79Se(n,γ) cross sections and compare them with TALYS predictionms and earlier work by other groups.

  4. MAPEAMENTO DO FLUXO DE VALOR E KAIZEN COMO INSTRUMENTOS DE REDUÇÃO DE PERDAS: UM CASO NA INDÚSTRIA DE MOTOSSERRAS

    Directory of Open Access Journals (Sweden)

    Luis Gilberto Scherer

    2007-01-01

    Full Text Available Tem se verificado que as operações industriais aplicam, cada vez mais, esforços e recursos no sentido de promover a melhoria contínua de seus processos e assim garantir uma sólida posição no mercado. Este artigo visa a identificar oportunidades de redução das perdas do processo de manufatura, através da utilização da ferramenta de mapeamento de fluxo de valor e a aplicação de Kaizen. Trata-se de um estudo de caso na indústria de motosserras, em que há um levantamento detalhado de dados de todo o processo produtivo através do mapeamento da cadeia de valor, desde o recebimento da matéria-prima até os clientes. A partir da análise desses dados, demonstra-se o aumento de produtividade e outros ganhos em termos de resposta rápida e flexibilidade. Palavras-Chave: Mapeamento do Fluxo de Valor. Kaizen. Produtividade.

  5. Fundamental absorption edge in CuIn5Se8 and CuGa3Se5 single crystals

    International Nuclear Information System (INIS)

    Leon, M.; Merino, J.M.; Levcenko, S.; Nateprov, A.; Tezlevan, V.; Arushanov, E.; Syrbu, N.N.

    2006-01-01

    Optical absorption spectra of CuIn 5 Se 8 and CuGa 3 Se 5 single crystals have been investigated. The energy gap E g for CuIn 5 Se 8 (CuGa 3 Se 5 ) was found to be varied from 1.27(1.79) to 1.21(1.71) eV in the temperature range between 10 and 300 K. The temperature dependence of E g was studied by means of the Einstein model and the Paessler model. The Einstein temperature {222(267)K}, the Debye temperature {310(380)K}, a dimensionless constant related to the electron-phonon coupling {1.62(2.65)} as well as an effective energy {20 (24) meV} and a cut-off phonon energy {35(39) meV} have been estimated for CuIn 5 Se 8 (CuGa 3 Se 5 ). It was also found that the major contribution of phonons to the shift of E g versus temperature in CuIn 5 Se 8 (CuGa 3 Se 5 ) is mainly from optical phonons. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  6. Charge confinements in CdSe-ZnSe symmetric double quantum wells

    International Nuclear Information System (INIS)

    Tit, Nacir; Obaidat, Ihab M

    2008-01-01

    The bound states in the (CdSe) N w (ZnSe) N b (CdSe) N w -ZnSe(001) symmetric double quantum wells are investigated versus the well width (N w ) and the barrier thickness (N b ). A calculation based on the sp 3 s * tight-binding method which includes the spin-orbit interactions is employed to calculate the bandgap energy, quantum-confinement energy, and band structures. The studied systems possess a vanishing valence-band offset (VBO = 0) in consistency with the well known common-anion rule, and a large conduction-band offset (CBO ≅ 1 eV), which plays an essential role in the confinement of electrons within the CdSe wells. The biaxial strain, on the other hand, plays another role in confining the holes at the interfaces (within the well regions) and thus enhancing the radiative efficiency. The induced-strain energy is estimated to be ∼35 meV. More importantly, the results show that, for a fixed barrier thickness, the double wells are able to confine a pair of bound states when they are very thin. By increasing the wells' width (N w ), further, a new pair of states from the conduction-band continuum falls into the wells every time N w hits a multiple of four monolayers (more specifically, for 4n w ≤4(n+1), the number of bound states is 2(n+1), where n is an integer). On the other hand, the barrier thickness (N b ) is shown to have no effect on the number of bound states, but it solely controls their well-to-well interactions. A critical barrier thickness to switch off these latter interactions is estimated to occur at about N crit b ≅ 9 (L crit b ≅ 25∼AA. Rules governing the variation of the quantum-confinement energy versus both barrier thickness (N b ) and well width (N w ) have been derived. Our theoretical results are also shown to have excellent agreement with the available experimental photoluminescence data

  7. AgSbSe{sub 2} and AgSb(S,Se){sub 2} thin films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Garza, J.G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Shaji, S. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Facultad de Ingenieria Mecanica y Electrica, CIIDIT - Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Rodriguez, A.C.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Krishnan, B., E-mail: kbindu_k@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Facultad de Ingenieria Mecanica y Electrica, CIIDIT - Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2011-10-01

    Silver antimony selenide (AgSbSe{sub 2}) thin films were prepared by heating sequentially deposited multilayers of antimony sulphide (Sb{sub 2}S{sub 3}), silver selenide (Ag{sub 2}Se), selenium (Se) and silver (Ag). Sb{sub 2}S{sub 3} thin film was prepared from a chemical bath containing SbCl{sub 3} and Na{sub 2}S{sub 2}O{sub 3}, Ag{sub 2}Se from a solution containing AgNO{sub 3} and Na{sub 2}SeSO{sub 3} and Se thin films from an acidified solution of Na{sub 2}SeSO{sub 3}, at room temperature on glass substrates. Ag thin film was deposited by thermal evaporation. The annealing temperature was 350 deg. C in vacuum (10{sup -3} Torr) for 1 h. X-ray diffraction analysis showed that the thin films formed were polycrystalline AgSbSe{sub 2} or AgSb(S,Se){sub 2} depending on selenium content in the precursor films. Morphology and elemental analysis of these films were done using scanning electron microscopy and energy dispersive X-ray spectroscopy. Optical band gap was evaluated from the UV-visible absorption spectra of these films. Electrical characterizations were done using Hall effect and photocurrent measurements. A photovoltaic structure: glass/ITO/CdS/AgSbSe{sub 2}/Al was formed, in which CdS was deposited by chemical bath deposition. J-V characteristics of this structure showed V{sub oc} = 435 mV and J{sub sc} = 0.08 mA/cm{sup 2} under illumination using a tungsten halogen lamp. Preparation of a photovoltaic structure using AgSbSe{sub 2} as an absorber material by a non-toxic selenization process is achieved.

  8. Padrões, Estratégias de Competição e Competitividade

    Directory of Open Access Journals (Sweden)

    Dirceu Grasel

    2011-05-01

    Full Text Available Este trabalho mostra que o aumento da competição internacional e o aumento do grau de exigência dos consumidores estabeleceram novos parâmetros de competição, gerando, por sua vez, inconsistências para os parâmetros tradicionais de tomada de decisão. Neste sentido, objetiva-se contribuir para o debate sobre a nova visão de competitividade, baseada em padrões de competição e destacar a necessidade de incorporação desses aspectos nas decisões empresariais. Conclui-se que, no contexto atual, estratégia baseada exclusivamente no mínimo custo deixa de ser regra geral para tornar-se estratégia aplicável a determinados tipos de estruturas industriais, embora esse nunca possa ser menosprezado. Em produtos de elevado valor agregado, geralmente os setores mais dinâmicos da economia, qualidade e preço baixo se tornaram requisitos mínimos para a sobrevivência no mercado e as estratégias empresariais devem levar em conta os padrões de concorrência da indústria, definidos pelos seus clientes.

  9. Uma instituição de ensino popular no Maranhão império: a Sociedade Onze de Agosto

    Directory of Open Access Journals (Sweden)

    Samuel Luis Velázquez Castellanos

    2015-08-01

    Full Text Available Propõe-se a análise da contribuição da “Sociedade Onze de Agosto”, procurando entendê-la como centro de referência cultural no solo maranhense do século XIX. Esta instituição tinha a finalidade de oferecer a instrução das primeiras letras à população adulta, com privilégio aos conteúdos das artes mecânicas e industriais. Descreve-se o movimento social, político e educacional do oitocentos, de modo a situar as condições que propiciaram a criação do estabelecimento em 1870. Considera-se o ensino noturno oferecido aos trabalhadores em diferentes localidades da Província, como Caxias, Alcântara e São Bento, por exemplo. Enfatiza-se a Escola Normal criada pela “Sociedade Onze de Agosto”, que objetiva formar professores e professoras para o ensino primário, para o ensino das artes voltadas às atividades manuais (carpinteiro, sapateiro, alfaiate, etc. e para a indústria, o comércio e a lavoura.

  10. Porøse materialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2000-01-01

    Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM).......Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM)....

  11. Synthesis and properties of new CdSe-AgI-As{sub 2}Se{sub 3} chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, M. [Univ Lille Nord de France, F-59000 Lille (France); ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque (France); Le Coq, D., E-mail: david.lecoq@univ-littoral.fr [Univ Lille Nord de France, F-59000 Lille (France); ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque (France); Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E. [Univ Lille Nord de France, F-59000 Lille (France); ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque (France)

    2011-02-15

    Research highlights: {yields} Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system. {yields} Characterization of macroscopic properties of the new CdSe-AgI-As{sub 2}Se{sub 3} glasses. {yields} Far infrared transmission of chalcogenide glasses. {yields} Characterization of the total conductivity of CdSe-AgI-As{sub 2}Se{sub 3} glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T{sub g}), crystallisation (T{sub x}), and melting (T{sub m}) temperatures are reported and used to calculate their {Delta}T = T{sub x} - T{sub g} and their Hruby, H{sub r} = (T{sub x} - T{sub g})/(T{sub m} - T{sub x}), criteria. Evolution of the total electrical conductivity {sigma} and the room temperature conductivity {sigma}{sub 298} was also studied. The terahertz transparency domain in the 50-600 cm{sup -1} region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  12. Effect of dietary sodium selenite, Se-enriched yeast and Se-enriched Chlorella on egg Se concentration, physical parameters of eggs and laying hen production

    Czech Academy of Sciences Publication Activity Database

    Skřivan, M.; Šimáně, J.; Dlouhá, G.; Doucha, Jiří

    2006-01-01

    Roč. 51, č. 4 (2006), s. 163-167 ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50200510 Keywords : sodium selenite * se-yeast * se-chlorella Subject RIV: EE - Microbiology, Virology Impact factor: 0.421, year: 2006

  13. Effect of the ITO substrate on the growth of Cu(In,Ga)Se{sub 2}, CuGa{sub 3}Se{sub 5}, CuGa{sub 5}Se{sub 8} and CuIn{sub 3}Se{sub 5} thin films by flash evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, E J; Merino, J M; Leon, M [Department of Applied Physics, Universidad Autonoma de Madrid (UAM), Cantoblanco, 28049 Madrid (Spain); Trigo, J F; Guillen, C [Department of Energy, CIEMAT, Avda Complutense, 22, 28040 Madrid (Spain); Ramiro, J, E-mail: josue.friedrich@uam.e [Department of Theory of Signal and Communications, URJC, Campus Fuenlabrada, 122, 28943 Madrid (Spain)

    2009-04-21

    Structural, compositional, electrical and morphological properties of CuIn{sub 1-x}Ga{sub x}Se{sub 2} (x = 0.15, 0.30) and ordered defect compounds (ODC) CuGa{sub 3}Se{sub 5}, CuGa{sub 5}Se{sub 8}, CuIn{sub 3}Se{sub 5} thin films grown by flash evaporation onto soda lime glass substrates (SLG) and ITO/SLG have been studied. Polycrystalline thin films with accentuated preferential orientation in the (1 1 2) plane of the tetragonal structure have been obtained. Annealing in Se atmosphere improves the structural, morphological, electrical and optical properties of the evaporated films, but provokes the formation of a CuIn{sub x}Se{sub y} phase on the surface of the films. Band gap values ranging between 1.01 and 1.21 eV have been obtained for the as-grown CuIn{sub 1-x}Ga{sub x}Se{sub 2} thin films and between 1.09 and 2.01 eV for the CuGa{sub 3}Se{sub 5}, CuGa{sub 5}Se{sub 8} and CuIn{sub 3}Se{sub 5} thin films.

  14. Cu(InGa)Se{sub 2} absorber formation by in-situ, low-temperature annealing of co-evaporated bilayer (InGa){sub 2}Se{sub 3}/CuSe precursors

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Kyeongchan; Kim, Woo Kyoung, E-mail: wkim@ynu.ac.kr

    2015-12-01

    Chalcopyrite Cu(InGa)Se{sub 2} (CIGS) absorbers were fabricated by the formation of bilayer stacked glass/Mo/(InGa){sub 2}Se{sub 3}/CuSe precursors followed by in-situ thermal annealing at 450 °C for approximately 10 min in a vacuum evaporator. The material properties (e.g., crystal orientation, compositional depth profile, and overall composition) and device performance of the resulting CIGS absorbers were compared with those of the CIGS absorbers formed by conventional 1-stage and 3-stage CIGS formation processes at a similar temperature. X-ray diffraction confirmed that the 1-stage co-evaporation and in-situ annealing of the bilayer precursor produced a polycrystalline CIGS absorber without a specific texture, whereas the CIGS absorber formed by the 3-stage process showed a highly (220) preferred orientation. Secondary ion mass spectrometry revealed Ga accumulation at the bottom of CIGS formed by in-situ annealing of the bilayer precursors. The cell efficiency of the device with the CIGS absorber formed by the in-situ, low-temperature (450 °C) annealing of bilayer stacked glass/Mo/(InGa){sub 2}Se{sub 3}/CuSe precursors was comparable to that produced by the conventional 3-stage process at a similar temperature. - Highlights: • Annealing of (InGa){sub 2}Se{sub 3}/CuSe precursors was compared with coevaporation process. • In-situ annealing of (InGa){sub 2}Se{sub 3}/CuSe precursors at 450 °C produced about 9% solar cell. • Ga profile within Cu(InGa)Se{sub 2} depended on process profile during co-evaporation.

  15. Short and medium range structures of 80GeSe2–20Ga2Se3 chalcogenide glasses

    Science.gov (United States)

    Petracovschi, Elena; Calvez, Laurent; Cormier, Laurent; Le Coq, David; Du, Jincheng

    2018-05-01

    The short and medium range structures of 80GeSe2–20Ga2Se3 (or Ge23.5Ga11.8Se64.7) chalcogenide glasses have been studied by combining ab initio molecular dynamics (AIMD) simulations and experimental neutron diffraction studies. The structure factor and total correlation function were calculated from glass structures generated from AIMD simulations and compared with neutron diffraction experiments showing reasonable agreement. The atomic structures of ternary chalcogenide glasses were analyzed in detail, and it was found that gallium atoms are four-fold coordinated by selenium (Se) and form [GaSe4] tetrahedra. Germanium atoms on average also have four-fold coordination, among which Se is 3.5 with the remaining being Ge–Ge homo-nuclear bonds. Ga and Ge tetrahedra link together mainly through corner-sharing and some edge-sharing of Se. No homo-nuclear bonds were observed among Ga atoms or between Ge and Ga. In addition, Se–Se homo-nuclear bonds and Se chains with various lengths were observed. A small fraction of Se atom triclusters that bond to three cations of Ge and Ga were also observed, confirming earlier proposals from 77Se solid state nuclear magnetic resonance studies. Furthermore, the electronic structures of ternary chalcogenide glasses were studied in terms of atomic charge and electronic density of states in order to gain insights into the chemical bonding and electronic properties, as well as to provide an explanation of the observed atomic structures in these ternary chalcogenide glasses.

  16. Absorption Spectra of CuGaSe2 and CuInSe2 Semiconducting Nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb; Singh, Nirpendra; Schwingenschlö gl, Udo

    2015-01-01

    The structural and optical properties of the chalcopyrite CunGanSe2n and CunInnSe2n nanoclusters (n = 2, 4, 6, and 8) are investigated as a function of the size using a combination of basin-hopping global optimization and time-dependent density

  17. Assessment of the anticancer compounds Se-methylselenocysteine and glucosinolates in Se-biofortified broccoli (Brassica oleracea L. var. italica) sprouts and florets.

    Science.gov (United States)

    Ávila, Fabricio William; Faquin, Valdemar; Yang, Yong; Ramos, Silvio Junio; Guilherme, Luiz Roberto G; Thannhauser, Theodore W; Li, Li

    2013-07-03

    Broccoli (Brassica oleracea L. var. italica) is a rich source of chemopreventive compounds. Here, we evaluated and compared the effect of selenium (Se) treatment on the accumulation of anticancer compounds Se-methylselenocysteine (SeMSCys) and glucosinolates in broccoli sprouts and florets. Total Se and SeMSCys content in sprouts increased concomitantly with increasing Se doses. Selenate was superior to selenite in inducing total Se accumulation, but selenite is equally effective as selenate in promoting SeMSCys synthesis in sprouts. Increasing sulfur doses reduced total Se and SeMSCys content in sprouts treated with selenate, but not in those with selenite. Examination of five broccoli cultivars reveals that sprouts generally have better fractional ability than florets to convert inorganic Se into SeMSCys. Distinctive glucosinolate profiles between sprouts and florets were observed, and sprouts contained approximately 6-fold more glucoraphanin than florets. In contrast to florets, glucosinolate content was not affected by Se treatment in sprouts. Thus, Se-enriched broccoli sprouts are excellent for simultaneous accumulation of chemopreventive compounds SeMSCys and glucoraphanin.

  18. Enhanced thermoelectric properties of N-type polycrystalline In4Se3-x compounds via thermally induced Se deficiency

    Science.gov (United States)

    Zhao, Ran; Shu, Yu-Tian; Guo, Fu

    2014-03-01

    In4Se3-x compound is considered as a potential thermoelectric material due to its comparably low thermal conductivity among all existing ones. While most studies investigated In4Se3-x thermoelectric properties by controlling selennium or other dopants concentrations, in the current study, it was found that even for a fixed initial In/Se ratio, the resulting In/Se ratio varied significantly with different thermal processing histories (i.e., melting and annealing), which also resulted in varied thermoelectric properties as well as fracture surface morphologies of In4Se3-x polycrystalline specimens. Single phase polycrystalline In4Se3-x compounds were synthesized by combining a sequence of melting, annealing, pulverizing, and spark plasma sintering. The extension of previous thermal history was observed to significantly improve the electrical conductivity (about 121%) and figure of merit (about 53%) of In4Se3-x polycrystalline compounds. The extended thermal history resulted in the increase of Se deficiency (x) from 0.39 to 0.53. This thermally induced Se deficiency was observed to associate with increasing carrier mobility but decreasing concentration, which differs from the general trend observed for the initially adjusted Se deficiency at room temperature. Unusually large dispersed grains with nanosize layers were observed in specimens with the longest thermal history. The mechanism(s) by which previous thermal processing enhances carrier mobility and affect microstructural evolution are briefly discussed.

  19. Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-03-01

    Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

  20. Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-05-01

    Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

  1. Mudança de comportamento de médicos com transferência passiva de informações

    Directory of Open Access Journals (Sweden)

    Jorge de Azevedo

    Full Text Available Avaliou-se a mudança de comportamento de um grupo de médicos empregando-se a mala direta como estratégia de divulgação de informações, objetivando otimizar o uso de "Serviços Auxiliares de Diagnose e Terapia - SADT" numa regional de cooperativa médica do Sul do Brasil. Do total de 176 médicos, 130 constituíram a amostra para estudo quase-experimento. Utilizando-se o método Audit and Feedback, mensalmente durante um ano, a relação SADT solicitados/consultas atendidas (aqui denominada "Índice de Solicitação de SADT - IsSADT" retornou em forma de gráficos aos médicos. Para análises, os respondentes foram estratificados de diferentes formas, compararam-se os IsSADT pré e pós-intervenções e entre e intraestratos com testes de Wilcoxon, Mann-Whitney e Kruskall Wallis. Apesar de as solicitações de SADT que vinham sendo praticadas serem o quádruplo do estimado para a população de beneficiários, o comportamento do grupo estudado não se modificou com o fornecimento de informações desacompanhadas de outras medidas administrativas

  2. Formation of ZnSe/Bi2Se3 QDs by surface cation exchange and high photothermal conversion

    Directory of Open Access Journals (Sweden)

    Guozhi Jia

    2015-08-01

    Full Text Available Water-dispersed core/shell structure ZnSe/Bi2Se3 quantum dots were synthesized by ultrasonicwave-assisted cation exchange reaction. Only surface Zn ion can be replaced by Bi ion in ZnSe quantum dots, which lead to the ultrathin Bi2Se3 shell layer formed. It is significance to find to change the crystal of QDs due to the acting of ultrasonicwave. Cation exchange mechanism and excellent photothermal conversion properties are discussed in detail.

  3. Absorption Spectra of CuGaSe2 and CuInSe2 Semiconducting Nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2015-10-01

    The structural and optical properties of the chalcopyrite CunGanSe2n and CunInnSe2n nanoclusters (n = 2, 4, 6, and 8) are investigated as a function of the size using a combination of basin-hopping global optimization and time-dependent density functional theory. Although the lowest energy structures are found to show almost random geometries, the band gaps and absorption spectra still are subject to systematic blue shifts for decreasing cluster size in the case of CunGanSe2n, indicating strong electron confinement. The applicability of the nanoclusters in photovoltaics is discussed. © 2015 American Chemical Society.

  4. Die tema van God se spraak in Hebreërs se inleidingsformules

    Directory of Open Access Journals (Sweden)

    Albert J. Coetsee

    2015-03-01

    Full Text Available Alhoewel die voorkoms en gebruik van die Ou Testament in die meeste navorsing oor Hebreërs besonder baie aandag geniet, is dit nie die geval met die Hebreërskrywer se gebruik van inleidingsformules vir sy Ou-Testamentiese aanhalings nie. Die gevolg is dat daar tot op hede betreklik min selfstandige navorsing oor die Hebreërskrywer se tema van God se spraak by sy inleidingsformules gedoen is. In hierdie artikel word Hebreërs se inleidingsformules in besonderhede nagegaan om te bepaal wat die aard en inhoud van die Hebreërskrywer se verwysings na die tema van God se spraak in sy inleidingsformules is. Daar word onder andere bepaal dat Hebreërs 38 direkte aanhalings vanuit die Ou Testament bevat, dat die Hebreërskrywer, met slegs een uitsondering, elke inleidingsformule met ’n werkwoord van sêinlei, dat ’n Persoon van die Drie-eenheid in 34 van die 38 direkte aanhalings (± 89% die onderwerp en gevolglike Spreker van die Ou-Testamentiese woorde is, dat die Hebreërskrywer al drie Persone van die Drie-eenheid as God beskou, en dat die Hebreërskrywer oortuig is dat die Ou Testament geïnspireer is en God se geldige en relevante openbaring bly. The theme of God’s speech in Hebrews’ introduction formulae. Whilst the occurance and function of the Old Testament in research on Hebrews enjoys a lot of attention, this is not the case for the writer of Hebrews’ use of introduction formulae for his Old Testament quotations. The result is that up to date relatively few independent studies have been made on the writer of Hebrews’ theme of God’s speech in his introduction formulae. In this article the introduction formulae in Hebrews are researched in detail to determine the nature and content of the writer of Hebrews’ reference to the theme of God’s speech in his introduction formulae. Amongst other things it is determined that Hebrews has 38 direct quotations from the Old Testament, that with the exception of one

  5. SE debt restructuring plan

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

    Slovenske elektrarne, a.s. (SE) plans to restructure one's own debts in 2003-2005. Debt restructuring plan is following: 2003: Collection of pre-payment on electricity - 60 million Euro (2.5 billion Slovak crowns), consumer unknown. Own promissory notes in total value of 100 million US$ (3.5 billion Slovak crowns) - in process. Sale of claims worth 2.4 billion Slovak crowns (57.21 million Euro) - negotiations in process. 2003/2004: Restructuring of loans payable IV. quarter 2003 and at the beginning of 2004 in value of 200 million Euro (8.3 billion Slovak crowns). Aim of SE is a new credit payable within 7 years, with instalments payable in the last two to three without any state subsidies. 2005: Loans worth 460 million Euro (189 billion Slovak crowns) will still remain. SE want to negotiate them with banks without state support

  6. Sample Set (SE): SE47 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE47 Metabolomic correlation-network modules in Arabidopsis based on a graph-cluste...as a system. Typical metabolomics data show a few but significant correlations among metabolite levels when ...itions. Although several studies have assessed topologies in metabolomic correlation networks, it remains un... (mto1), and transparent testa4 (tt4) to compare systematically the metabolomic correlation...s in samples of roots and aerial parts. We then applied graph clustering to the constructed correlation

  7. Polytypism and band alignment in ZnSe nanowires revealed by photoluminescence spectroscopy of embedded (Zn,Cd)Se quantum dots

    Science.gov (United States)

    Bieker, S.; Pfeuffer, R.; Kiessling, T.; Tarakina, N.; Schumacher, C.; Ossau, W.; Molenkamp, L. W.; Karczewski, G.

    2015-03-01

    We report on the optical characterization of single (Zn,Cd)Se quantum dots (QDs) embedded in vapor-liquid-solid-grown ZnSe nanowires (NWs). The temperature dependent quenching of the QD luminescence demonstrates that their electronic structure is comparable to that of self-assembled (Zn,Cd)Se QDs in ZnSe matrices. The photoluminescence excitation (PLE) spectrum of single nanowire QDs reveals the presence of both zinc blende (ZB) and wurtzite (WZ) crystal modifications of ZnSe in the NW shafts. PLE provides, therefore, a complementary technique to transmission electron microscopy imaging to reveal polytypism in ZnSe NWs. A transient quenching of the PL emission suggests a type II staggered band alignment at the ZB/WZ interface in our ZnSe NWs.

  8. FRAGILIDADE POTENCIAL E EMERGENTE NA BACIA DO RIO DAS PEDRAS, GUARAPUAVA, PR - BRASIL

    Directory of Open Access Journals (Sweden)

    Paulo Eugênio Pachechenik

    2013-10-01

    Full Text Available O presente trabalho teve por objetivo delimitar a potencialidade do uso do solo para auxiliar no planejamento da exploração dos recursos naturais da bacia do rio das Pedras, situada no município de Guarapuava, Paraná, Brasil. Aplicou-se uma metodologia de análise empírica da fragilidade ambiental, digitalizando a área e rede de drenagem da bacia, e gerando-se, posteriormente, um modelo numérico do terreno, empregando programas especializados. A área da bacia apresenta fragilidade ambiental potencial entre as classes “média” e “alta”, com os usos do solo classificando-a na fragilidade ambiental emergente “muito baixa” e “baixa”. Os limites da potencialidade de uso do solo indicam que a bacia está protegida da erosão e os fatores de forma demonstram, para as atuais condições, que há “pequena” possibilidade de ocorrer enchentes.

  9. Efeito de diferentes fertilizantes nitrogenados na produção do trigo em vasos Effect of different nitrogen fertilizers on wheat production

    Directory of Open Access Journals (Sweden)

    Hermano Gargantini

    1972-01-01

    Full Text Available Estudou-se a influência do sulfato de amônio, do salitre-do-chile e da uréia no desenvolvimento e na produção do trigo, em vasos, em casa de vegetação, empregando-se um Latossolo Vermelho Escuro orto, do município de Itapetininga, Estado de São Paulo. Os resultados indicaram que, para produção de matéria seca, não houve diferença entre os fertilizantes utilizados, porém para produção de grãos o sulfato de amônio foi o mais eficiente.The influence of ammonium sulphate, Chilean nitrate, and urea on wheat production was studied in a greenhouse pot experiment using a ortho Dark Red Latosol. The results showed that in the dry matter production any difference was noted among the fertilizers compared; in grain production, however, ammonium sulphate gave the best results.

  10. CdSe/ZnSe quantum dot structures grown by molecular beam epitaxy with a CdTe submonolayer stressor

    International Nuclear Information System (INIS)

    Sedova, I. V.; Lyublinskaya, O. G.; Sorokin, S. V.; Sitnikova, A. A.; Toropov, A. A.; Donatini, F.; Dang, Si Le; Ivanov, S. V.

    2007-01-01

    A procedure for formation of CdSe quantum dots (QDs) in a ZnSe matrix is suggested. The procedure is based on the introduction of a CdTe submonolayer stressor deposited on the matrix surface just before deposition of the material of the QDs. (For CdTe/ZnSe structure, the relative lattice mismatch is Δa/a ∼ 14%.) The stressor forms small strained islands at the ZnSe surface, thus producing local fields of high elastic stresses controlling the process of the self-assembling of the QDs. According to the data of transmission electron microscopy, this procedure allows a considerable increase in the surface density of QDs, with a certain decrease in their lateral dimensions (down to 4.5 ± 1.5 nm). In the photoluminescence spectra, a noticeable (∼150 meV) shift of the peak to longer wavelengths from the position of the reference CdSe/ZnSe QD structure is observed. The shift is due to some transformation of the morphology of the QDs and an increase in the Cd content in the QDs. Comprehensive studies of the nanostructures by recording and analyzing the excitation spectra of photoluminescence, the time-resolved photoluminescence spectra, and the cathodoluminescence spectra show that the emission spectra involve two types of optical transitions, namely, the type-I transitions in the CdSeTe/ZnSe QDs and the type-II transitions caused mainly by the low cadmium content (Zn,Cd)(Se,Te)/ZnSe layer formed between the QDs

  11. Effective mRNA Inhibition in PANC-1 Cells in Vitro Mediated via an mPEG-SeSe-PEI Delivery System.

    Science.gov (United States)

    Zhang, Yuefeng; Yang, Bin; Liu, Yajie; Qin, Wenjie; Li, Chao; Wang, Lantian; Zheng, Wen; Wu, Yulian

    2016-05-01

    RNA interference (RNAi)-mediated gene therapy is a promising approach to cure various diseases. However, developing an effective, safe, specific RNAi delivery system remains a major challenge. In this study, a novel redox-responsive polyetherimide (PEI)-based nanovector, mPEG-SeSe-PEI, was developed and its efficacy evaluated. We prepared three mPEG-SeSe-PEI vector candidates for small interfering glyceraldehyde-3-phosphate dehydrogenase (siGADPH) and determined their physiochemical properties and transfection efficiency using flow cytometry and PEG11.6-SeSe-PEI polymer. We investigated the silencing efficacy of GADPH mRNA expression in PANC-1 cells and observed that PEG11.6-SeSe-PEI/siGADPH (N/P ratio=10) polyplexes possessed the appropriate size and zeta-potential and exhibited excellent in vitro gene silencing effects with the least cytotoxicity in PANC-1 cells. In conclusion, we present PEG11.6-SeSe-PEI as a potential therapeutic gene delivery system for small interfering RNA (siRNA).

  12. Turismo gastronômico, cultura e comida de festa

    Directory of Open Access Journals (Sweden)

    Beber, Ana Maria Costa

    2017-06-01

    Full Text Available As migrações da Península Itálica para o sul do Brasil datam da segunda metade do século XIX. As adaptações ao novo território marcaram as práticas culinárias desses grupos. Este artigo apresenta a situação atual das comunidades originadas na imigração, em termos de suas práticas alimentares associadas às festas locais e, consequentemente, ao turismo. O procedimento metodológico retomou pesquisas anteriores no mesmo local, utilizando seus dados primários. Depois, realizaram-se entrevistas semiestruturadas com mulheres, que atualmente vivem na mesma comunidade. Os resultados comparados mostram mudanças associadas à origem dos ingredientes, uso de novas tecnologias e introdução de produtos industriais, bem como uma nova organização nos menus. Pratos cotidianos tornaram-se parte da chamada comida de festa, depois apresentados aos turistas como marcas de identidade da comunidade local.

  13. Negative ion photoelectron spectroscopy of SeO-

    International Nuclear Information System (INIS)

    Coe, J.V.; Snodgrass, J.T.; Freidhoff, C.B.; McHugh, K.M.; Bowen, K.H.

    1985-01-01

    Negative ion photoelectron spectroscopy (NIPES) involves a kinetic energy analysis of electrons which are photodetached when a mass selected beam of negative ions is crossed with a fixed frequency laser beam. The photodetachment spectra of SeO - displays transitions from the X 2 PI state of SeO - to both the X 3 Σ - and a 1 Δ states of SeO. The singlet-triplet splitting of SeO is readily observable since selection rules regarding spin do not apply in the bound to free state process of photodetachment. The electron affinity of SeO and the negative ion potential parameters of SeO - have been determined

  14. Syntheses, structures, and properties of Ag4(Mo2O5)(SeO4)2(SeO3) and Ag2(MoO3)3SeO3

    International Nuclear Information System (INIS)

    Ling Jie; Albrecht-Schmitt, Thomas E.

    2007-01-01

    Ag 4 (Mo 2 O 5 )(SeO 4 ) 2 (SeO 3 ) has been synthesized by reacting AgNO 3 , MoO 3 , and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO 2 2+ molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C 2 distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C 2 distortion. Upon heating Ag 4 (Mo 2 O 5 )(SeO 4 ) 2 (SeO 3 ) looses SeO 2 in two distinct steps to yield Ag 2 MoO 4 . Crystallographic data: (193 K; MoKα, λ=0.71073 A): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) A, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2σ(I). Ag 2 (MoO 3 ) 3 SeO 3 was synthesized by reacting AgNO 3 with MoO 3 , SeO 2 , and HF under hydrothermal conditions. The structure of Ag 2 (MoO 3 ) 3 SeO 3 consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO 6 units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoKα, λ=0.71073 A): monoclinic, space group P2 1 /n, a=7.7034(5), b=11.1485(8), c=12.7500(9) A, β=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2σ(I). Ag 2 (MoO 3 ) 3 SeO 3 decomposes to Ag 2 Mo 3 O 10 on heating above 550 deg. C. - Graphical abstract: A view of the one-dimensional [(Mo 2 O 5 )(SeO 4 ) 2 (SeO 3 )] 4- chains that extend down the c-axis in the structure of Ag 4 (Mo 2 O 5 )(SeO 4

  15. Modelo Hackefors para obtenção de certificado ambiental ISO-14.001 em pequenas e médias empresas: uma discussão sobre sua aplicação em empresas brasileiras

    Directory of Open Access Journals (Sweden)

    José Jorge Abdalla

    Full Text Available Baseado em estudo feito no Distrito Industrial Fazenda Botafogo, no município do Rio de Janeiro, este artigo analisa a possibilidade de aplicação conjunta em distritos industriais brasileiros de um modelo de sistema de gestão ambiental (SGA, o modelo Hackefors, criado para facilitar a obtenção da certificação ambiental ISO 14.001 por empresas de pequeno e médio porte de distritos industriais na Suécia. O modelo Hackefors, surgido em 1997 no distrito sueco que lhe deu o nome, foi adotado por 450 empresas de 24 distritos industriais daquele país, basicamente, por ter possibilitado a certificação ambiental a cada empresa que a ele aderiu, com ganhos individuais e coletivos para as mesmas. Para a elaboração deste artigo, foi analisada a literatura sobre distritos industriais e sistemas de gestão ambiental e, também, consultados documentos relativos ao modelo Hackefors e ao Distrito Industrial Fazenda Botafogo. Além disso, foram entrevistados consultores que trabalharam na implantação do referido modelo, representantes das empresas do distrito industrial carioca e especialistas em certificação ISO 14.001. Esse esforço permitiu comparar as duas situações e fazer algumas considerações sobre a aplicação do modelo sueco em Fazenda Botafogo. O resultado mostra que as diferenças entre as situações iniciais de atuação ambiental nos dois distritos não são um empecilho à construção de redes. Revela ainda que as semelhanças existentes sugerem que a aplicação do modelo Hackefors no distrito industrial do Rio de Janeiro poderia ser bem-sucedida. Por outro lado, em Fazenda Botafogo não foi identificado nenhum fator que transformasse a busca individual por um sistema de gestão ambiental nos moldes da ISO 14.001 numa busca coletiva, como ocorreu nos distritos industriais suecos.

  16. Pulsed laser deposited heterogeneous mixture of Li2Se-Sb2Se3 nanocomposite as a new storage lithium material

    International Nuclear Information System (INIS)

    Yu Le; Chen Jie; Fu Zhengwen

    2010-01-01

    Li 2 Se-Sb 2 Se 3 nanocomposites with a highly heterogeneous mixture have been fabricated by reactive pulsed laser deposition method. The electrochemical properties of the as-deposited Li 2 Se-Sb 2 Se 3 thin film during the first charging and discharging have been investigated by the galvanostatic cycling and cyclic voltammetry measurements for the first time. By using ex situ X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and selected-area electron diffraction (SAED) measurements, the decomposition of Li 2 Se driven by Sb 2 Se 3 under the electrochemical potential is revealed. In the first cycle, the oxidation peaks at 2.5 V and 3.2 V and the reduction peaks at 2.0 V can be attributed to the decomposition and formation of Li 2 Se with the conversion reaction of Sb 2 Se 3 into Sb 2 Se 5 . Our findings demonstrate that nanocomposite Li 2 Se-Sb 2 Se 3 can possess very high electrochemical activity. These results present a special case of solid-state heterogeneous electrochemistry with both nanostructured binary materials.

  17. Surface Passivation of CdSe Quantum Dots in All Inorganic Amorphous Solid by Forming Cd1-xZnxSe Shell.

    Science.gov (United States)

    Xia, Mengling; Liu, Chao; Zhao, Zhiyong; Wang, Jing; Lin, Changgui; Xu, Yinsheng; Heo, Jong; Dai, Shixun; Han, Jianjun; Zhao, Xiujian

    2017-02-07

    CdSe quantum dots (QDs) doped glasses have been widely investigated for optical filters, LED color converter and other optical emitters. Unlike CdSe QDs in solution, it is difficult to passivate the surface defects of CdSe QDs in glass matrix, which strongly suppress its intrinsic emission. In this study, surface passivation of CdSe quantum dots (QDs) by Cd 1-x Zn x Se shell in silicate glass was reported. An increase in the Se/Cd ratio can lead to the partial passivation of the surface states and appearance of the intrinsic emission of CdSe QDs. Optimizing the heat-treatment condition promotes the incorporation of Zn into CdSe QDs and results in the quenching of the defect emission. Formation of CdSe/Cd 1-x Zn x Se core/graded shell QDs is evidenced by the experimental results of TEM and Raman spectroscopy. Realization of the surface passivation and intrinsic emission of II-VI QDs may facilitate the wide applications of QDs doped all inorganic amorphous materials.

  18. Phase diagrams of novel Tl{sub 4}SnSe{sub 4}–TlSbSe{sub 2}–Tl{sub 2}SnSe{sub 3} quasi-ternary system following DTA and X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Barchiy, I.E.; Tatzkar, A.R. [Department of Chemistry, Uzhgorod National University, Pidgirna St., 46, Uzhgorod 88000 (Ukraine); Fedorchuk, A.O. [Department of Inorganic and Organic Chemistry, Lviv National University of Veterinary Medicine and Biotechnologies, Pekarska St., 50, Lviv 79010 (Ukraine); Plucinski, K., E-mail: kpluc2006@wp.pl [Electronics Department, Military University Technology, Warsaw, Kaliskiego 2, Warsaw 00-908 (Poland)

    2016-06-25

    Phase relation in the Tl{sub 4}SnSe{sub 4}–TlSbSe{sub 2}–Tl{sub 2}SnSe{sub 3} quasiternary system were studied by the DTA and X-ray diffraction in combination with mathematical modeling. The phase diagrams of the Tl{sub 4}SnSe{sub 4}–TlSbSe{sub 2} and Tl{sub 2}SnSe{sub 3}–TlSbSe{sub 2} systems, the perspective views of the phase interaction in the ternary system, the liquidus surface projection, the isothermal section at 423 K were built for the first time. The Tl{sub 4}SnSe{sub 4}–TlSbSe{sub 2}–Tl{sub 2}SnSe{sub 3} system is of the invariant eutectic type and is characterized by the formation of limited solid solutions following initial ternary compounds. New complex compounds are not formed. - Highlights: • Two Tl{sub 4}SnSe{sub 4}–TlSbSe{sub 2},Tl{sub 2}SnSe{sub 3}–TlSbSe{sub 2} systems were explored. • Invariant processes in the ternary system were determined. • New complex compounds were not observed in ternary system.

  19. Two anionically derivatized scandium oxoselenates(IV): ScF[SeO3] and Sc2O2[SeO3

    Science.gov (United States)

    Greiner, Stefan; Chou, Sheng-Chun; Schleid, Thomas

    2017-02-01

    Scandium fluoride oxoselenate(IV) ScF[SeO3] and scandium oxide oxoselenate(IV) Sc2O2[SeO3] could be synthesized through solid-state reactions. ScF[SeO3] was obtained phase-pure, by reacting mixtures of Sc2O3, ScF3 and SeO2 (molar ratio: 1:1:3) together with CsBr as fluxing agent in corundum crucibles embedded into evacuated glassy silica ampoules after firing at 700 °C for seven days. Sc2O2[SeO3] first emerged as by-product during the attempts to synthesize ScCl[SeO3] following aforementioned synthesis route and could later be reproduced from appropriate Sc2O3/SeO3 mixtures. ScF[SeO3] crystallizes monoclinically in space group P21/m with a=406.43(2), b =661.09(4), c=632.35(4) pm, β=93.298(3)° and Z=2. Sc2O2[SeO3] also crystallizes in the monoclinic system, but in space group P21/n with a=786.02(6), b=527.98(4), c=1086.11(8) pm, β=108.672(3)° for Z=4. The crystal structures of both compounds are strongly influenced by the stereochemically active lone pairs of the ψ1-tetrahedral [SeO3]2- anions. They also show partial structures, where the derivatizing F- or O2- anions play an important role. For ScF[SeO3] chains of the composition 2+∞ 1[FS c 2 / 2 ] form from connected [FSc2]5+ dumbbells, while [OSc3]7+ pyramids and [OSc4]10+ tetrahedra units are condensed to layers according to 2+ ∞ 2[O2Sc2 ] in Sc2O2[SeO3].

  20. Possibility of using BeMgZnSe as a new cladding material for ZnSe-based blue laser diodes

    International Nuclear Information System (INIS)

    Kim, D. C.; Choi, J. H.; Yoo, K. H.; Kim, T. W.; Yao, T.

    1999-01-01

    We calculated the gain and the radiative recombination current density of ZnSe/Be x Mg y Zn 1-x-y Se/Be x Mg y Zn 1-x - y Se separate confinement heterostructure (SCH) laser diodes and compared the results with those for the more popular ZnSe/Zn 1-x Mg x S y Se 1-y /Zn 1-x Mg x S y Se 1-y system. For five different values of the cladding-layer energy gap (E g,c ), we sought the optimum SCH structure that had a minimum threshold current density for both quaternaries, and we compared the corresponding current densities. For the same E g,c , ZnMgSSe was found to have a smaller threshold current density. The threshold current density decreased rapidly with increasing. E g,c in both materials. Therefore, if the available energy gap of the BeMgZnSe cladding is larger than that of ZnMGZnSSe, BeMgZnSe may be the better choice

  1. Cs2UPd3Se6

    Directory of Open Access Journals (Sweden)

    George N. Oh

    2011-02-01

    Full Text Available Dicaesium uranium(IV tripalladium(II hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2, Cs1 (222, Cs2 (m2m, Pd1 (.m., Pd2 (2mm, Se1 (m.., and Se2 (1. This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010. The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.

  2. C-type Nd2Se3

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The title compound, neodymium sesquiselenide, is isotypic with the other known rare-earth metal(III selenides M2Se3 (M = La–Pr and Sm–Lu with the cubic C-type structure. It adopts a cation-defective Th3P4-type arrangement with close to 8/9 of the unique neodymium-cation site occupied, leading to the composition Nd2.667Se4 (Z = 4 or Nd2Se3 (Z = 5.333, respectively. The Nd3+ cations are thus surrounded by eight selenide anions, forming trigonal [NdSe8]13− dodecahedra, whereas the Se2− anions exhibit a sixfold coordination, but due to the under-occupation of neodymium, each one is statistically surrounded by only 5.333 cations. The crystal studied was a merohedral twin with a 0.31 (6:0.69 (6 domain ratio.

  3. Opportunities and challenges for a sustainable energy policy in SE Europe: SE European Energy Community Treaty

    International Nuclear Information System (INIS)

    Mihajlov, Andjelka

    2010-01-01

    Energy demand continues to increase in turn raising concerns about energy supply. In this paper, the author has tried to systematize the role of the energy sector in South Eastern (SE) Europe in the context of the European energy policy process. This should make the energy sector in SE Europe more visible and open to substantial activities and appropriate funding. This is important to assure its full alignment with the European energy policy process, and in so doing, make it less fragile. According to the SE European Energy Community Treaty, parties to the Treaty are obliged to implement reforms in the energy and environmental sector in accordance with the European Union's respective policy. This paper raises awareness of the environmental requirements that have been set, of renewable energy and its implementation, at the same time pointing out that the response in SE Europe has been at a low level. It is believed that this paper could draw attention to the existing problems and could contribute to the establishment of a common integrated energy market in SE Europe and the EU. (author)

  4. E-beam irradiation effect on CdSe/ZnSe QD formation by MBE: deep level transient spectroscopy and cathodoluminescence studies

    International Nuclear Information System (INIS)

    Kozlovsky, V I; Litvinov, V G; Sadofyev, Yu G

    2004-01-01

    CdSe/ZnSe structures containing 1 or 15 thin (3-5 monolayers) CdSe layers were studied by cathodoluminescence (CL) and deep level transient spectroscopy (DLTS). The DLTS spectra consisted of peaks from deep levels (DLs) and an additional intense peak due to electron emission from the ground quantized level in the CdSe layers. Activation energy of this additional peak correlated with an energy of the CdSe-layer emission line in the CL spectra. Electron-beam irradiation of the structure during the growth process was found to influence the DLTS and CL spectra of the CdSe layers, shifting the CdSe-layer emission line to the long-wave side. The obtained results are explained using the assumption that e-beam irradiation stimulates the formation of quantum dots of various sizes in the CdSe layers

  5. ¿ Como se hace una Telenovela ?

    Directory of Open Access Journals (Sweden)

    Iván Gavaldón

    2015-01-01

    Full Text Available La autora relata la historia de las Relaciones Públicas y dice que surgieron y se desarrollaron para legitimar ante el público los intereses económicos y políticos de quienes detentan el poder. Se cuestiona sobre el por qué no aplicar las relaciones públicas, en organizaciones populares, para que mejoren su publicación y orienten sus propósitos de desarrollo. El tema que aborda las Políticas culturales en América Latina acopia un extracto de lo más trascendente de los ensayos del libro editado por Néstor García Canclini. Sobre la telenovela se afirma que esta ha llegado a ser uno de los instrumentos más importantes de la comunicación popular: por ella desfilan las identidades de las más variadas culturas brasileñas. Y en cuanto a la caricatura se relata lo que ocurrió en el Seminario taller " Caricatura y Periodismo", realizado el(9-11 de Nov.- 1987 en el CIESPAL. El estudio sobre el mercado del vídeo se ve dificultado por la imprecisión de los datos obtenidos. Los datos oficiales no siempre se aproximan a la realidad, pues el mercado de vídeo se instauró en América Latina partiendo de una lógica totalmente diversa de los equipos de sonido e imagen.

  6. Facile fabrication of CNTs@C@MoSe2@Se hybrids with amorphous structure for high performance anode in lithium-ion batteries.

    Science.gov (United States)

    Jin, Rencheng; Cui, Yuming; Wang, Qingyao; Li, Guihua

    2017-12-15

    Amorphous MoSe 2 and Se anchored on amorphous carbon coated multiwalled carbon nanotubes (CNTs@C@MoSe 2 @Se) have been synthesized by a facile solvothermal strategy. The one dimensional CNTs@C@MoSe 2 @Se can effectively buffer the volume variation, prohibit the aggregation and facilitate electron and ion transport throughout the electrode. Furthermore, the combination of MoSe 2 and Se also provides buffer spaces for the volumetric change during cycling. Thus, the obtained CNTs@C@MoSe 2 @Se hybrids display the enhanced cycle stability and excellent high rate capacity. The reversible capacity of 1010mAhg -1 can be achieved after 100 cycles at the current density of 0.1Ag -1 . Even after 500 cycles, a reversible capacity of 508mAhg -1 is still retained at 5Ag -1 . Copyright © 2017 Elsevier Inc. All rights reserved.

  7. PbSe Quantum Well VECSEL on Si

    Science.gov (United States)

    Fill, M.; Khiar, A.; Rahim, M.; Felder, F.; Zogg, H.

    2011-12-01

    Vertical external cavity surface emitting lasers in the wavelength region from 3-5 μm are presented. They are based on PbSe quantum wells grown on Si substrates. As host material Pb1-xEuxSe and Pb1-xSrxSe are used. With Pb1-xSrxSe as host material maximum operation temperatures of 325 K are achieved, while with Pb1-xEuxSe an operation temperature of 245 K could not be overcome. This may be explained by a band alignment transition from type I to type II with increasing temperature.

  8. Investigation of short and ballistic coupling in vertical NbSe2 - graphene - NbSe2 Josephson junctions

    Science.gov (United States)

    Kim, Minsoo; Park, Geon-Hyoung; Yi, Jongyoon; Lee, Jae Hyeong; Park, Jinho; Lee, Hu-Jong

    2H-NbSe2 is a layered two-dimensional superconducting material, which can be constructed into a van der Waals heterostructure with versatile functionality. Here we fabricated a vertically stacked NbSe2 - graphene - NbSe2 heterostructure by the dry transfer technique, where defect-free contact via van der Waals force provides the high interfacial transparency. Insertion of an atomically thin graphene layer between two NbSe2 flakes ensures the formation of highly coherent proximity Josephson coupling. Observed temperature dependence of the junction critical current (Ic) and large value of IcRn product (as large as 2.3ΔNbSe 2) reveal the short and ballistic Josephson coupling characteristics. Large junction critical current density of 104 A/cm2, multiple Andreev reflection in the subgap structure of the differential conductance, and magnetic field modulation of Ic also suggest the strong Josephson coupling via the graphene layer.

  9. PHEIFFER SE TAALPOLITIEK JC Steyn

    African Journals Online (AJOL)

    sigself maak tog nie Chomsky se teorie oor n aangebore taalaanleg en die konsekwensie daarvan nl. dat elke taal opgebou moet wees volgens dieselfde grondprinsipes, ongeldig nie? Taalpolitieke oortuigingskrag het hierdie argument nog minder. Sal jy in alle erns vir mense kan se: "Ons moet aanhou om die taal te praat ...

  10. Assessing the anticancer compounds Se-methylselenocysteine and glucosinolates in Se-biofortified broccoli (brassica oleracea L. var. italica) sprouts and florets

    Science.gov (United States)

    Broccoli (Brassica oleracea L. var. italica) is a rich source of chemopreventive compounds. Here, we evaluated and compared the effect of selenium (Se) treatment on the accumulation of anticancer compound Se-methylselenocysteine (SeMSCys) and glucosinolates in broccoli sprouts and florets. Total Se ...

  11. The effects of staggered bandgap in the InP/CdSe and CdSe/InP core/shell quantum dots.

    Science.gov (United States)

    Kim, Sunghoon; Park, Jaehyun; Kim, Sungwoo; Jung, Won; Sung, Jaeyoung; Kim, Sang-Wook

    2010-06-15

    New type-II structures of CdSe/InP and InP/CdSe core-shell nanocrystals which have staggered bandgap alignment were fabricated. Using a simple model for the wave function for electrons and holes in InP/CdSe and CdSe/InP core/shell nanocrystals showed the wave function of the electron and hole spread into the shell, respectively. The probability density of the InP/CdSe and CdSe/InP core/shell QDs also showed a similar tendency. As a result, the structure exhibits increased delocalization of electrons and holes, leading to a red-shift in absorption and emission. Quantum yield increased in the InP/CdSe, however decreased in the CdSe/InP. The reason may be due to the surface trap and high activation barrier for de-trapping in the InP shell. 2010 Elsevier Inc. All rights reserved.

  12. O humano desumanizado num mundo sem sentido: Samuel Beckett e o herói absurdo = The dehumanized human being in a nonsense world: Samuel Beckett and the absurd hero

    Directory of Open Access Journals (Sweden)

    Maristela Kirst de Lima Girola

    2011-01-01

    Full Text Available Este ensaio tem como objetivo discutir a construção das personagens emEsperando Godot, de Samuel Beckett, apoiando-se nos estudos de Martin Esslin sobre o Teatro do Absurdo, uma forma de drama que enfatiza o absurdo da existência humana, empregando fragmentação, repetição e ininteligibilidade, como reação artística à Segunda Guerra Mundial.This essay discusses the construction of the characters in Waiting for Godot by Samuel Beckett, based on Martin Esslin’s studies on the Theatre of the Absurd, a form of drama that emphasizes the absurdity of human existence by employing split subjects, repetitions and meaninglessness as artistic reactions to World War II.

  13. Glass forming tendencies of chalcogenides of the system (As2Se3)sub(1-x):(T12Se)sub(x)

    International Nuclear Information System (INIS)

    Majid, C.A.

    1982-07-01

    In this paper glass forming capabilities of chalcogenide glasses based on As 2 Se 3 with T1 2 Se concentrations are discussed. The studies were made using the differential thermal analysis (DTA) technique. These studies show that the glass forming tendency of As 2 Se 3 decreases as the concentrations of T1 2 Se molecules are increased. Also these studies show that with addition of T1 2 Se, the glass transition temperature Tsub(g) of As 2 Se 3 decreases, suggesting a tendency for weaker bonding and hence less stability of T1-rich compositions. (author)

  14. Synthesis of dextran/Se nanocomposites for nanomedicine application

    International Nuclear Information System (INIS)

    Shen Yuhua; Wang Xiufang; Xie Anjian; Huang Lachun; Zhu Jinmiao; Chen Long

    2008-01-01

    In this study, spherical Se nanoparticles were prepared by the reduction of aqueous selenious acid with ice bath through a simple, conventional, and one-step method without the aid of any surfactant, or template. The nanoparticles were characterized by transmission electron microscopy (TEM), photon correlation spectroscopy (PCS), X-ray powder diffraction (XRD), Ultraviolet-visible spectroscopy (UV-vis), Zeta potential, respectively. The results show the Se nanoparticles have good particle dispersion with the average diameters of 36 nm and are amorphous (α-Se). Tablets A and B containing dextran and Se nanoparticles were synthesized with different preparation methods. Se nanoparticles studded equably in the interior and the surface of the tablets, and there are strong interactions between Se and dextran. The release of Se from tablets is investigated in the simulated gastric and intestinal conditions. It is found that the pH environment and different synthetical methods have significant influence on the release rate of Se. The release mechanism of Se nanoparticles is also discussed. The nanocomposites can be applied in controlled releasing of Se nanomedicine

  15. Molecular structure of virgin and Tg cycled (Ag2Se)x (AsSe)1-x bulk glasses

    Science.gov (United States)

    Wachtman, Jacob; Chen, Ping; Boochand, P.

    2009-03-01

    AsSe, the base glass (x = 0) in the titled ternary, is an interesting example of a chalcogenide that is partially de-mixed into As4Se4 molecules segregated from a connected AsSe network, with the latter determining glass network properties. Raman scattering reveals sharp modes of the Realgar molecules that are superimposed on broad modes coming from of the backbone. Upon Tg cycling virgin samples (as quenched melts), the concentration of de-mixed As4Se4 molecules decreases, suggesting that thermally induced polymerization occurs; molecules break up to form part of the connective tissue. Modulated DSC experiments reveal a broad exotherm near 140 ^oC in virgin samples, which becomes nearly extinct in Tg cycled samples. The exotherm may represent Realgar molecules nano-crystallizing as the temperature approaches Tg. Compositional trends in thermal parameters such as Tg(x), δCp(x), and the δHnr(x) as a function of Ag2Se content `x' of the glasses will be reported.

  16. Autismos que se 'curan'

    OpenAIRE

    Artigas, Josep, 1948-; Paula Pérez, Isabel, 1970-

    2016-01-01

    Introducción. La investigación sobre el autismo, basada principalmente en el modelo categórico del Manual diagnóstico y estadístico de los trastornos mentales, se ha centrado de forma preferente en la epidemiología, las manifestaciones clínicas, los mecanismos cognitivos y los determinantes biológicos y ambientales; sin embargo, se ha prestado escaso interés a las trayectorias evolutivas, las cuales son decisivas de cara al pronóstico a medio y largo plazo. Objetivo. Revisar el curso evolutiv...

  17. Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}, and Cs{sub 7}[Fe{sub 4}Se{sub 8}]. Missing links of known chalcogenido ferrate series

    Energy Technology Data Exchange (ETDEWEB)

    Stueble, Pirmin; Roehr, Caroline [Institut fuer Anorganische und Analytische Chemie, Universitaet Freiburg (Germany)

    2017-11-17

    The three cesium selenido ferrate title compounds with an Se:Fe ratio of 2:1 were synthesized from stoichiometric samples reacting elemental Cs either (A) with Fe and Se in a double-crucible setup (Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}) or (B) with previously prepared FeSe{sub 2} (Cs{sub 3}[FeSe{sub 2}]{sub 2}, Cs{sub 7}[Fe{sub 4}S{sub 8}]) (T{sub max} = 800-1000 C). The pure Fe{sup III} ferrate Cs[FeSe{sub 2}] crystallizes in the Tl[FeSe{sub 2}] type [monoclinic, space group C2/m, a = 1392.95(10), b = 564.43(3), c = 737.44(6) pm, β = 119.163(5) , Z = 4, R{sub 1} = 0.0550]. It is thus not isotypic to all other alkali ferrates(III) A[FeS{sub 2}] and A[FeSe{sub 2}] containing chains of edge-sharing tetrahedra, but crystallizes in a t2 subgroup of the Immm structure of Cs[FeS{sub 2}]. The mixed-valent chain compound Cs{sub 3}[FeSe{sub 2}]{sub 2} is isotypic to its sulfido analogue [orthorhombic, space group Pnma, a = 777.88(6), b = 1151.02(6), c = 1341.61(7) pm, Z = 4, R{sub 1} = 0.0470]. In contrast to the isopunctal Na{sub 3}[FeSe{sub 2}]{sub 2} type K/Rb compounds the chains are only slightly corrugated. The monoclinic, likewise mixed-valent Fe{sup II/III} selenido ferrate Cs{sub 7}[Fe{sub 4}Se{sub 8}] [monoclinic, space group C2/c, a = 1953.79(10), b = 879.71(5), c = 1717.03(10) pm, β = 117.890(2) , Z = 4, R{sub 1} = 0.0816] is isostructural both to the cesium sulfido and tellurido compound. The structure contains oligomeric moieties of four edge sharing [FeSe{sub 4}] tetrahedra forming slightly distorted tetrahedral clusters [Fe{sub 4}Se{sub 8}]{sup 7-}, which are surrounded by a cube of 26 Cs cations. Based on a structure map, the crystal chemistry of the three title compounds is discussed together with all chain/cluster ferrates of the general series A{sub 1+x}[Fe{sup III}{sub 1-x}Fe{sup II}{sub x}Q{sub 2}] (x = 0-1; A = Na, K, Rb, Cs; Q = S, Se, Te). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. A simple and facile synthesis of MPA capped CdSe and CdSe/CdS core/shell nanoparticles

    Science.gov (United States)

    Sukanya, D.; Sagayaraj, P.

    2015-06-01

    II-VI semiconductor nanostructures, in particular, CdSe quantum dots have drawn a lot of attention because of their promising potential applications in biological tagging, photovoltaic, display devices etc. due to their excellent optical properties, high emission quantum yield, size dependent emission wavelength and high photostability. In this paper, we describe the synthesis and properties of mercaptopropionic acid capped CdSe and CdSe/CdS nanoparticles through a simple and efficient co-precipitation method followed by hydrothermal treatment. The growth process, characterization and the optical absorption as a function of wavelength for the synthesized MPA capped CdSe and CdSe/CdS nanoparticles have been determined using X-ray diffraction study (XRD), Ultraviolet-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) and High Resolution Transmission Electron Microscopy (HRTEM).

  19. A simple and facile synthesis of MPA capped CdSe and CdSe/CdS core/shell nanoparticles

    International Nuclear Information System (INIS)

    Sukanya, D.; Sagayaraj, P.

    2015-01-01

    II-VI semiconductor nanostructures, in particular, CdSe quantum dots have drawn a lot of attention because of their promising potential applications in biological tagging, photovoltaic, display devices etc. due to their excellent optical properties, high emission quantum yield, size dependent emission wavelength and high photostability. In this paper, we describe the synthesis and properties of mercaptopropionic acid capped CdSe and CdSe/CdS nanoparticles through a simple and efficient co-precipitation method followed by hydrothermal treatment. The growth process, characterization and the optical absorption as a function of wavelength for the synthesized MPA capped CdSe and CdSe/CdS nanoparticles have been determined using X-ray diffraction study (XRD), Ultraviolet-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) and High Resolution Transmission Electron Microscopy (HRTEM)

  20. Como Perseu se defendeu de Medusa?

    Directory of Open Access Journals (Sweden)

    Rose Lumertz de Freitas

    2012-04-01

    Full Text Available Na psicanálise francesa, principalmente com Lacan, o conceito de falta passou a ser de grande importância. Ao que, então, perguntamos: o que é a falta? E quando esta falta? O que acontece? O que acontece quando o não especularizável não está excluído, se fazendo, assim, especular? Quando Perseu vai ao encontro de Medusa, guiando-se por sua imagem refletida em um espelho de bronze polido, segurado por Atena, como pôde este herói defender-se de Medusa? Qual foi a forma encontrada por ele para se defender da presença do objeto que introduz a dimensão do real nu?

  1. Apical and periapical repair of dogs' teeth with periapical lesions after endodontic treatment with different root canal sealers Reparação apical e periapical de dentes de cães com lesão periapical crônica após tratamento endodôntico utilizando diferentes materiais obturadores

    Directory of Open Access Journals (Sweden)

    Mário Roberto Leonardo

    2003-03-01

    Full Text Available The aim of this study was to evaluate the apical and periapical repair after root canal treatment of dogs' teeth with pulp necrosis and chronic periapical lesion using different root canal sealers. After periapical lesion induction, forty-four root canals of 3 dogs were submitted to biomechanical preparation using 5.25% sodium hypochlorite as an irrigating solution. A calcium hydroxide dressing (Calen PMCC was applied for 15 days and the root canals were filled using the lateral condensation technique with gutta-percha points and Sealapex, AH Plus or Sealer Plus for sealing. After 180 days, the animals were sacrificed by anesthetic overdose and the obtained histological sections were stained with hematoxylin-eosin for optical microscopic analysis of the apical and periapical repair. The groups filled with Sealapex and AH Plus had better histological repair (p O objetivo do presente estudo foi avaliar a reparação apical e periapical pós-tratamento endodôntico de dentes de cães com necrose pulpar e reação periapical crônica, em que se utilizaram diferentes materiais obturadores. Foram utilizados 44 canais radiculares, nos quais, após indução das lesões periapicais, foi efetuado o preparo biomecânico empregando-se como solução irrigadora uma solução de hipoclorito de sódio a 5,25%. Após curativo de demora com pasta à base de hidróxido de cálcio (Calen PMCC, mantida no canal radicular durante 15 dias, os canais radiculares foram obturados pela técnica clássica complementada pela condensação lateral ativa, empregando-se os cimentos Sealapex, AH Plus ou Sealer Plus. Decorrido o período de 180 dias, os animais foram mortos e as peças submetidas ao processamento laboratorial. Os cortes histológicos obtidos foram corados com hematoxilina-eosina. A análise histopatológica demonstrou que nos canais radiculares obturados com os cimentos Sealapex e AH Plus ocorreu melhor reparação (p < 0,05 do que nos canais obturados com o

  2. Construção sustentável : contributos do gesso para a sustentabilidade da construção

    OpenAIRE

    Torgal, Fernando Pacheco; Jalali, Said

    2010-01-01

    Este artigo apresenta uma revisão da literatura sobre o contributo do gesso para a sustentabilidade da indústria construção. A utilização de gesso obtido como sub-produto em vários processos industriais, o reaproveitamento do gesso quer durante a fase de construção ou demolição ou mesmo a produção de materiais à base de gesso incorporando resíduos industriais, são temas abordadas no presente artigo os quais constituem contributos inequívocos para uma construção mais sustentável....

  3. Seleção de flexibilidades de manufatura: uma analogia à carteira de ações para minimização de riscos e problemas no ambiente fabril Manufacturing flexibility selection: an analogy to the stock portfolio management for risk and problem minimization in the manufacturing environment

    Directory of Open Access Journals (Sweden)

    Ualison Rébula Oliveira

    2010-01-01

    Full Text Available Para empresas de manufatura, vários autores recomendam a utilização da flexibilidade de manufatura para a minimização dos impactos prejudiciais que os riscos incutem às organizações. Entretanto, a característica multidimensional da flexibilidade de manufatura e os trade-offs existentes entre os diversos tipos dificultam a tarefa de se selecionar e adequar o grau de flexibilidade a ser adotado, frente às variáveis existentes. Além disso, a escolha indevida de tipos de flexibilidade para a solução de problemas pode gerar investimentos desnecessários e inadequados, ocasionando perda de capital e ineficiência no uso dos recursos flexíveis escolhidos para antecipação aos riscos. Assim, disponibilizar à gestão de operações resultados que permitam a seleção de diferentes tipos de flexibilidade, segundo as necessidades e a disponibilidade de recursos de cada empresa, torna-se crucial. Com esse propósito, efetuou-se uma pesquisa empírica que contemplou oito empresas de cinco segmentos industriais, na qual, por meio de uma analogia à diversificação de riscos em carteira de ações, propõe-se a composição de cinco diferentes tipos de carteiras de flexibilidades, para cinco diferentes segmentos industriais.Many authors recommend the use of manufacturing flexibility to minimize the harmful effects that risks instill in manufacturing companies. However, the multidimensional feature of manufacturing flexibility and the several different types of trade-offs make it difficult to select and customize the flexibility level to be adopted due to the existing variables. Moreover, choosing wrong types of flexibility for the solution of problems may lead to unnecessary and inadequate investments resulting in capital loss and inefficiency in the use of flexible resources for risk anticipation. Therefore, it becomes crucial to provide operations management with results that allow the selection of different types of flexibility according

  4. Comparing the influence of selenite (Se4+) and selenate (Se6+) on the inhibition of the mercury (Hg) phytotoxicity to pak choi.

    Science.gov (United States)

    Tran, Thi Anh Thu; Dinh, Quang Toan; Cui, Zeiwei; Huang, Jie; Wang, Dan; Wei, Tianjiao; Liang, Dongli; Sun, Xin; Ning, Ping

    2018-01-01

    Selenite (Se (IV)) and selenate (Se (IV)) have recently been demonstrated to be equally effective in inhibiting mercury (Hg) phytotoxicity to plants. This assertion is still unclear. In this study, we aimed to explore the potential effects of Se species (Se 4+ and Se 6+ ) on the inhibition of the mercury (Hg) bioavailability to pak choi in dry land. Pot experiments with exposure to different dosages of mercuric chloride (HgCl 2 ) and selenite (Na 2 SeO 3 ) or selenate (Na 2 SeO 4 ) were treated. To compare the influence of Se (IV) and Se (VI) on the bioaccumulation and bioavailability of Hg, the levels of total Hg in different pak choi (Brassica chinensis L.) tissues (roots and shoots) and the distribution changes of Hg fractions in soil before planting and after harvest were determined as well as the Hg I R values in soils (relative binding intensity) were analyzed. Results showed that application Se (IV) reduced the concentrations of Hg in pak choi roots more than Se (VI). Hg concentrations were also decreased in pak choi shoots in Se (IV) treatments, while which notably increased in Se (VI) treatments. Thus, Se (IV) plays a more important role than Se (VI) in limiting the absorption and bioaccumulation of Hg in pak choi. Moreover, this inhibition may only significantly occur when Se (IV) is at an appropriate level (2.5mg/kg). In addition, the good correlations between the proportions of mobile Hg fractions (soluble and exchangeable fractions), I R values with the Hg concentrations in plants were observed. This affirmed the importance of the Hg fractions transformation and the I R indicator of Hg in the assessment of their bioavailability. Our findings regarding the importance of Se (IV) influence in reducing Hg bioaccumulation not only provided the correct appraisal about the effect of Se species on the inhibition of the Hg phytotoxicity to pak choi in dry land, but also be a good reference for selecting Se fertilizer forms (Se 4+ or Se 6+ ). Copyright © 2017

  5. Surface half-metallicity of half-Heusler compound FeCrSe and interface half-metallicity of FeCrSe/GaP

    Energy Technology Data Exchange (ETDEWEB)

    Khalaf Al-zyadi, Jabbar M., E-mail: jabbar_alzyadi@yahoo.com [Department of Physics, College of Education for Pure Sciences, University of Basrah (Iraq); Jolan, Mudhahir H. [Department of Physics, College of Education for Pure Sciences, University of Basrah (Iraq); Yao, Kai-Lun, E-mail: klyao@mail.hust.edu.cn [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); International Center of Materials Physics, Chinese Academy of Sciences, Shenyang 110015 (China)

    2016-04-01

    Recent studies showed that half-Heusler FeCrSe exhibits half-metallic ferromagnetism (Huang et al. [20]). In this paper, we investigate extensively the electronic, magnetic, and half-metallic properties of the half-Heusler alloy FeCrSe (111) and (001) surfaces and the interface with GaP (111) substrate by using the first-principles calculations within the density functional theory. The atomic density of states demonstrates that the half-me tallicity verified in the bulk FeCrSe is maintained at the CrSe-terminated (001) and Se-terminated (111) surfaces, but lost at both Cr- and Fe-terminated (111) surfaces and the Fe-terminated (001) surface. Alternatively, for the interface of FeCrSe/GaP (111), the bulk half-metallicity is destroyed at Se–P configuration while Se–Ga interface and subinterface show nearly 100% spin polarization. Moreover, the calculated interfacial adhesion energies exhibit that Se–Ga shape is more stable than the Se–P one. The calculated magnetic moments of Se, Ga at the Se–Ga (111) interface and P at the Se–P (111) interface increase with respect to the corresponding bulk values while the atomic magnetic moment of Se atom at the Se–P (111) interface decreases. We also notice that the magnetic moments of subinterface Fe at both Se–Ga and Se–P (111) interfaces decrease compared to the bulk values. - Highlights: • The half-metallicity verified in the bulk FeCrSe is kept at the CrSe-terminated (001) and Se-terminated (111) surfaces. • The calculated interfacial adhesion energies exhibit that Se–Ga shape is more stable than Se–P. • The magnetic moments of Se, Ga and P atoms at the interface increase. • The Se–Ga interface shows nearly 100% spin polarization.

  6. Transport Properties of ZnSe- ITO Hetero Junction

    Science.gov (United States)

    Ichibakase, Tsuyoshi

    In this report, ITO(Indium Tin Oxide) was used on the glass substrates as the transparent electrode, and ZnSe layer was prepared by the vacuum deposition on this ITO. Then, the electrical characteristics of this sample were investigated by mans of the electric current transport analysis. The sample that ZnSe was prepared as 3.4 μm in case of ITO-ZnSe sample, has high density level at the junction surface. The ITO-ZnSe junction has two type of diffusion current. However, the ITO-ZnSe sample that ZnSe layer was prepared as 0.1 μm can be assumed as the ohmic contact, and ITO-ZnSe(0.1μm) -CdTe sample shows the avalanche breakdown, and it is considered that the avalanche breakdown occurs in CdTe layer. It is difficult to occur the avalanche breakdown, if ZnSe-CdTe junction has high-density level and CdTe layer has high-density defect. Hence, the ZnSe-CdTe sample that CdTe layer was prepared on ITO-ZnSe(0.1μm) substrate has not high-density level at the junction surface, and the CdTe layer with little lattice imperfection can be prepared. It found that ITO-ZnSe(0.1μm) substrate is available for the II-VI compounds semiconductor device through above analysis result.

  7. Li diffusion in NbSe/sub 2/ and Ag/sub 0.25/NbSe/sub 2/ single crystals

    International Nuclear Information System (INIS)

    Folinsbee, J.T.; Simpson, A.M.; Jericho, M.H.

    1986-01-01

    Measurements are reported of the diffusion of Lithium into NbSe/sub 2/ and into NbSe/sub 2/ preintercalated with silver. Diffusion parallel to the layers is found to be at least 2 orders of magnitude greater than perpendicular to the layers, but not to be greatly affected by the presence of intercalated silver. The activation energy for Li hopping in NbSe/sub 2/ is estimated to be 520 meV. The staging structure of Ag/sub x/NbSe/sub 2/ is also reported. These results have implications for the characterization of cathode materials in intercalation batteries

  8. Luminescence of nanocrystalline ZnSe:Mn2+

    NARCIS (Netherlands)

    Suyver, J.F.; Wuister, S.F.; Kelly, J.J.; Meijerink, A.

    2000-01-01

    The luminescence properties of nanocrystalline ZnSe:Mn^(2+) prepared via an inorganic chemical synthesis are described. Photoluminescence spectra show distinct ZnSe and Mn^(2+) related emissions, both of which are excited via the ZnSe host lattice. The Mn^(2+) emission wavelength and the

  9. The Influence of Interfaces on Properties of Thin-Film Inorganic Structural Isomers Containing SnSe-NbSe2 Subunits.

    Science.gov (United States)

    Alemayehu, Matti B; Falmbigl, Matthias; Ta, Kim; Johnson, David C

    2015-04-28

    Inorganic isomers ([SnSe]1+δ)m(NbSe2)n([SnSe]1+δ)p(NbSe2)q([SnSe]1+δ)r(NbSe2)s where m, n, p, q, r, and s are integers and m + p + r = n + q + s = 4 were prepared using the modulated elemental reactant technique. This series of all six possible isomers provides an opportunity to study the influence of interface density on properties while maintaining the same unit cell size and composition. As expected, all six compounds were observed to have the same atomic compositions and an almost constant c-axis lattice parameter of ≈4.90(5) nm, with a slight trend in the c-axis lattice parameter correlated with the different number of interfaces in the isomers: two, four and six. The structures of the constituents in the ab-plane were independent of one another, confirming the nonepitaxial relationship between them. The temperature dependent electrical resistivities revealed metallic behavior for all the six compounds. Surprisingly, the electrical resistivity at room temperature decreases with increasing number of interfaces. Hall measurements suggest this results from changes in carrier concentration, which increases with increasing thickness of the thickest SnSe block in the isomer. Carrier mobility scales with the thickness of the thickest NbSe2 block due to increased interfacial scattering as the NbSe2 blocks become thinner. The observed behavior suggests that the two constituents serve different purposes with respect to electrical transport. SnSe acts as a charge donor and NbSe2 acts as the charge transport layer. This separation of function suggests that such heterostructures can be designed to optimize performance through choice of constituent, layer thickness, and layer sequence. A simplistic model, which predicts the properties of the complex isomers from a weighted sum of the properties of building blocks, was developed. A theoretical model is needed to predict the optimal compound for specific properties among the many potential compounds that can be prepared.

  10. Removal of selenite by zero-valent iron combined with ultrasound: Se(IV) concentration changes, Se(VI) generation, and reaction mechanism.

    Science.gov (United States)

    Fu, Fenglian; Lu, Jianwei; Cheng, Zihang; Tang, Bing

    2016-03-01

    In this paper, the performance and application of zero-valent iron (ZVI) assisted by ultrasonic irradiation for the removal of selenite (Se(IV)) in wastewater was evaluated and reaction mechanism of Se(IV) with ZVI in such systems was investigated. A series of batch experiments were conducted to determine the effects of ultrasound power, pH, ZVI concentration, N2 and air on Se(IV) removal. ZVI before and after reaction with Se(IV) was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results indicated that ultrasound can lead to a significant synergy in the removal of Se(IV) by ZVI because ultrasound can promote the generation of OH and accelerate the advanced Fenton process. The primary reaction products of ZVI and Se(IV) were Se(0), ferrihydrite, and Fe2O3. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Semiconductor laser with longitudinal electron-beam pumping and based on a quantum-well ZnCdSe/ZnSe structure grown on a ZnSe substrate by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Kozlovskii, Vladimir I; Korostelin, Yurii V; Skasyrsky, Yan K; Shapkin, P V; Trubenko, P A; Dianov, Evgenii M

    1998-01-01

    The method of molecular beam epitaxy on a ZnSe substrate was used to grow a ZnCdSe/ZnSe structure with 115 quantum wells. This structure was made up into a cavity which included part of the substrate. Lasing was excited by longitudinal pumping with a scanning electron beam of E e = 40 - 70 keV energy. At T = 80 K for E e = 65 keV the threshold current density was 60 A cm -2 and the output power was 0.15 W at the 465 nm wavelength. At T= 300 K the lasing (λ= 474 nm) occurred in the ZnSe substrate. (lasers)

  12. Identificação de indicadores contábeis relevantes para previsão e projeção de rentabilidade

    Directory of Open Access Journals (Sweden)

    Andrei Aparecido de Albuquerque

    2010-12-01

    Full Text Available Vários estudos utilizando indicadores contábeis para a previsão de insolvência têm sido desenvolvidos desde as décadas de sessenta e setenta. Esses trabalhos buscam prever um possível estado de deterioração do desempenho financeiro das empresas, utilizando-se de modelos estatísticos. A presente pesquisa buscou identificar quais os indicadores contábeis mais significativos para a previsão de rentabilidade das empresas, propondo uma função que utilize indicadores passados como base para prever rentabilidade futura. Foram empregadas informações de todas as empresas não financeiras que estavam ativas e possuíam ações negociadas na Bolsa de Valores de São Paulo (Bovespa nos anos de 2004, 2003 e 2002. Utilizando-se a análise descritiva e empregando o modelo de regressão linear múltipla, verificaram-se quais foram as variáveis mais significativas com suas respectivas Ponderações. Conclui-se com uma função de previsão de ROA, contendo cinco variáveis independentes estatisticamente significantes ao nível de 5% (cinco porcento das doze selecionadas para o modelo inicial.

  13. Disposição em aterros controlados de resíduos sólidos industriais não-inertes: avaliação dos componentes tóxicos e implicações para o ambiente e para a saúde humana

    Directory of Open Access Journals (Sweden)

    Sisinno Cristina L. S.

    2003-01-01

    Full Text Available Para que um resíduo sólido seja disposto adequadamente, é necessário classificá-lo segundo as Normas Técnicas Brasileiras, cuja principal é a NBR 10.004. Resíduos sólidos industriais não-inertes normalmente têm sido encaminhados para disposição final em aterros controlados, que em sua maioria não operam de forma eficiente, além de estarem geralmente localizados próximos a núcleos populacionais e ecossistemas importantes. A fim de avaliar a toxicidade potencial dos resíduos produzidos em indústrias de diferentes segmentos, 21 amostras foram analisadas de acordo com as orientações descritas na NBR 10.004. Das amostras estudadas, 18 foram classificadas como resíduos não-inertes. Os principais parâmetros que contribuíram para a classificação das amostras em resíduos não-inertes foram: alumínio, ferro, manganês, fenol e surfactantes. Destes, o alumínio, o manganês e o fenol são as substâncias de maior interesse toxicológico para a saúde humana e ambiental, uma vez que podem alterar a qualidade das águas subterrâneas localizadas nas áreas de disposição de resíduos.

  14. SE-72/AS-72 generator system based on Se extraction/ As reextraction

    Science.gov (United States)

    Fassbender, Michael Ernst; Ballard, Beau D

    2013-09-10

    The preparation of a .sup.72Se/.sup.72As radioisotope generator involves forming an acidic aqueous solution of an irradiated alkali bromide target such as a NaBr target, oxidizing soluble bromide in the solution to elemental bromine, removing the elemental bromine, evaporating the resulting solution to a residue, removing hydrogen chloride from the residue, forming an acidic aqueous solution of the residue, adding a chelator that selectively forms a chelation complex with selenium, and extracting the chelation complex from the acidic aqueous solution into an organic phase. As the .sup.72Se generates .sup.72As in the organic phase, the .sup.72As may be extracted repeatedly from the organic phase with an aqueous acid solution.

  15. Avaliação das propriedades elétricas de barras estatóricas fabricadas com resina do tipo éter diglicidílico do bisfenol F (DGEBF contendo nanopartículas de silica

    Directory of Open Access Journals (Sweden)

    Rafael Novaes da Conceição

    Full Text Available Resumo O presente trabalho visa apresentar resultados da aplicação de uma resina epóxi bisfenólica (DGEBF à base de nanopartículas de sílica (RN e comparar suas propriedades com a resina convencional de referência epóxi bisfenólica (DGEBA (RE, atualmente utilizada. Neste sentido fabricaram-se protótipos de barras estatórica, destinadas a hidrogeradores, através do sistema VPI (Vácuo-Pressão-Impregnação e avaliaram-se as propriedades elétricas pelas técnicas de fator de dissipação e envelhecimento acelerado. Dentre os resultados para as resinas observou-se que: (i o fator de dissipação e de envelhecimento são praticamente os mesmos para ambas as resinas; (ii o valor de tip-up resultaram em 0,014% para RE e 0,020% para a resina RN e (iii a estimativa do tempo de vida útil esta em cerca de 40 anos, o que é aplicável para a maioria das aplicações industriais. Neste sentido sugere-se que a resina RN pode ser uma alternativa a resina RE, com um desempenho elétrico equivalente.

  16. Detecção, transmissão e patogenicidade de fungos em sementes de angico-vermelho (Parapiptadenia rigida

    Directory of Open Access Journals (Sweden)

    Caciara Gonzatto Maciel

    2012-12-01

    Full Text Available Angico-vermelho (Parapiptadenia rigida (Benth. Brenan é uma espécie nativa de grande valor ecológico e econômico, importante para a recomposição de áreas degradadas. O presente trabalho avaliou incidência, transmissão e patogenicidade de fungos associados a sementes de angico-vermelho de distintas procedências do Estado do Rio Grande do Sul. Para isso, utilizaram-se três amostras de sementes, com as quais realizaram-se testes de germinação, sanidade empregando-se o método do papel-filtro (PF e de plaqueamento em batata-dextrose-ágar (BDA, transmissão e patogenicidade dos fungos. A germinação das sementes de angico-vermelho variou de 63 a 91 %. Os fungos considerados potencialmente patogênicos encontrados associados as sementes de angico-vermelho foram: Alternaria sp.; Botrytis sp.; Fusarium sp.; Cladosporium sp. e Pestalotia sp.; sendo que Fusarium sp. foi detectado em todas as amostras pelo método PF, e foi transmitido via semente causando má formação do sistema radicular e dos cotilédones e tombamento de pré emergência. Sua patogenicidade foi confirmada.

  17. Purificação do extrato aquoso de Stevia rebaudiana Bertoni através dos processos com zeólitas e membranas - DOI: 10.4025/actascitechnol.v26i1.1546

    Directory of Open Access Journals (Sweden)

    Suzana Lemansky Rezende

    2004-03-01

    Full Text Available Neste trabalho utilizaram-se os seguintes processos de purificação do extrato aquoso de stevia a 10%: adsorção com zeólita CaX modificada por troca iônica, separação por ultrafiltração tangencial com membranas cerâmicas e o processo acoplado, zeólitas e membrana. Os melhores resultados de clarificação foram obtidos com o processo acoplado, empregando-se adsorção em leitos de zeólita CaX por 12 horas seguido da ultrafiltração em membrana cerâmica de tamanho médio dos poros 0,05 µm e pressão transmembrana de 4 bar. A clarificação final, após 2,5 horas de filtragem chegou a 99,56%. Esses resultados mostram que o processo acoplado, zeólitas e membrana, é promissor na purificação do extrato bruto de stevia. Porém o rendimento dos adoçantes (esteviosídeo e rebaudosídeo foi superior quando se trabalhou com o processo isolado com membranas

  18. Percepções de portadores de diabetes sobre a doença: contribuições da Enfermagem

    Directory of Open Access Journals (Sweden)

    Miriam de Oliveira Chaves

    Full Text Available Este estudo objetivou descrever a percepção dos usuários sobre a diabetes. A pesquisa foi descritiva e exploratória, com abordagem qualitativa; o cenário foi um hospital na cidade de Belém-PA, com participação de 32 sujeitos. Empregando-se a técnica de análise de conteúdo temática, emergiram quatro categorias: Controle do diabetes: a enfermagem na automonitorização da glicemia; O diabético e a enfermagem: uma interação para o autocuidado; Consulta de enfermagem ao diabético: a intervenção no processo saúde-doença; Diabetes e suas complicações: o medo repercutido na perda de funções. Observou-se que o paciente começa a se cuidar impulsionado pelo medo de perder sua saúde, obrigando-o ao autocuidado. O enfermeiro está diretamente ligado com o controle da diabetes, a partir do momento que realiza os cuidados e orientações da automonitorização da doença.

  19. Percepções de portadores de diabetes sobre a doença: contribuições da Enfermagem

    Directory of Open Access Journals (Sweden)

    Miriam de Oliveira Chaves

    2013-04-01

    Full Text Available Este estudo objetivou descrever a percepção dos usuários sobre a diabetes. A pesquisa foi descritiva e exploratória, com abordagem qualitativa; o cenário foi um hospital na cidade de Belém-PA, com participação de 32 sujeitos. Empregando-se a técnica de análise de conteúdo temática, emergiram quatro categorias: Controle do diabetes: a enfermagem na automonitorização da glicemia; O diabético e a enfermagem: uma interação para o autocuidado; Consulta de enfermagem ao diabético: a intervenção no processo saúde-doença; Diabetes e suas complicações: o medo repercutido na perda de funções. Observou-se que o paciente começa a se cuidar impulsionado pelo medo de perder sua saúde, obrigando-o ao autocuidado. O enfermeiro está diretamente ligado com o controle da diabetes, a partir do momento que realiza os cuidados e orientações da automonitorização da doença.

  20. Uso do metronidazol como medicação intracanal em dentes com necrose pulpar e reação periapical: relato de caso = The use of metronidazol as an intracanal medication for teeth with pulpar necrosis and periapical reaction: case report

    Directory of Open Access Journals (Sweden)

    Carneiro, Sérgio Murilo Barbalho de Souza

    2005-01-01

    Full Text Available O objetivo desse trabalho foi comparar dois tratamentos endodônticos realizados em dentes com abscesso periapical crônico, em um mesmo paciente, empregando-se medicações intracanais diferentes. Para isso foram relatados dois casos clínicos de tratamentos endodônticos em dois dentes (31 e 41, nos quais foram empregados a mesma técnica de preparo biomecânico e obturação, variando apenas a medicação intracanal, pois no dente 31 foi empregada uma pasta a base de hidróxido de cálcio (Calen e no dente 41, o metronidazol na forma de gel ginecológico. Após um ano de proservação dos tratamentos realizados, verificou-se reparação dos tecidos periapicais em ambos os dentes, concluindo-se que, nesse caso, a variação da medicação intracanal não interferiu no resultado do tratamento instituído e que o metronidazol pode ser uma alternativa viável como coadjuvante na terapia endodôntica desse tipo de patologia

  1. ¿Como se hace publicidad por internet?

    Directory of Open Access Journals (Sweden)

    Franz Del Pozo

    2015-01-01

    Full Text Available Internet es el medio de comunicación y venta con el mayor potencial de crecimiento y efectividad al más bajo precio. Para vender se usan tarjetas de crédito, depósitos bancarios, franqueo, comercio electrónico. Explica qué y cómo se hace publicidad por Internet. La Red se usa para difundir y para vender y hay la posibilidad de hacer algo diferente a más de llegar directamente al público objetivo se interactúa con él.

  2. Considerações sobre o desempenho de estruturas de concreto pré-moldado em situação de incêndio

    Directory of Open Access Journals (Sweden)

    Cassiano da Silva Zago

    Full Text Available A crescente utilização do concreto pré-moldado para solução estrutural em diversas obras, como edificações industriais e comerciais, tornou-se uma alternativa vantajosa e acessível, principalmente no quesito tempo de construção. Porém, quando em situação de incêndio, determinadas características que esse sistema construtivo usualmente oferece como vantagens podem tornar-se uma desvantagem. Contando com espaços amplos, com grandes vãos livres, materiais combustíveis armazenados e ventilação apropriada, torna-se um cenário ideal para a propagação de um incêndio e consequente perda da capacidade de suporte da estrutura. Neste trabalho são apresentadas as implicações de um projeto que utiliza o concreto pré-moldado em situação de incêndio, além de levantar pontos para discussões sobre possibilidades que amenizem os riscos, tendo como base referências bibliográficas nacionais e internacionais, de uso corrente no meio técnico e acadêmico.

  3. Análise econômica da primeira Lei de Patentes brasileira

    Directory of Open Access Journals (Sweden)

    Andrea Felippe Cabello

    Full Text Available Resumo O Brasil foi um dos primeiros países a ter uma lei de patentes e um dos únicos a conceder prazos de duração da patente de acordo com a qualidade da invenção. Este trabalho analisa um banco de dados inédito com todos os 783 privilégios industriais concedidos sob a vigência da primeira lei de patentes brasileira entre 1830 e 1882. Os resultados mostram que a atividade inventiva esteve conectada à estrutura econômica e social da época e que a escassez de mão de obra incentivou a invenção de máquinas e equipamentos para o setor cafeicultor. O número de patentes apenas começou a se elevar a partir de 1870, quando a economia brasileira passou por grandes mudanças que levaram ao seu desenvolvimento, evidenciando que pouco resultado surge quando se institui uma lei de patentes em um ambiente de estagnação econômica. Mesmo assim, a lei revelou-se o mecanismo menos dispendioso para estimular a atividade inventiva no Brasil do século XIX.

  4. A inércia estrutural da base produtiva brasileira: o IDE e a transferência internacional de tecnologia

    Directory of Open Access Journals (Sweden)

    TULIO CHIARINI

    2016-06-01

    Full Text Available RESUMO O que pode explicar o fato de ter havido uma entrada maciça de IDE no Brasil e ter-se mantido uma inercial estrutural na base produtiva nacional? Existe uma série de fatos macroeconômicos que podem ajudar a explicar essa inércia, como a baixa taxa de investimento e a falta de ordenação dos preços-chave da economia (como taxas de juros e taxa de câmbio, mas a proposição aqui feita é que existe um problema microeconômico estrutural relevante: falta de aptidão tecnológica das empresas industriais brasileiras. Para analisar tal proposição parte-se da separação entre os tipos de IDE (greenfield, fusão e aquisição e 'em carteira' e os tipos de canais de transferência de tecnologia (horizontal e vertical. A partir de elementos empíricos e históricos constrói-se o argumento de que a falta de aptidão tecnológica é elemento-chave no entendimento da perda de dinamismo da indústria nacional.

  5. Trabalho, educação e hegemonia nos anos 1930 e 1940 no Brasil análise a partir do IDORT

    Directory of Open Access Journals (Sweden)

    Eraldo Leme Batista

    2012-08-01

    Full Text Available Neste texto, analisamos o processo de fundação do IDORT1 (Instituto de OrganizaçãoRacional do Trabalho e os objetivos propostos para esta instituição, tendo por pressupostoo entendimento de que com a criação deste Instituto, tornam-se mais explícitos conceitosreferentes à educação para o trabalho, educação profissional, uma vez que a RevistaIDORT, principal meio utilizado para divulgar o pensamento dos industriais paulistas noperíodo, apresentava claramente a sua ideologia, atribuindo à educação papel fundamentalcomo instrumento disciplinador dos trabalhadores. Ao analisar a critica realizada pordiferentes autores, procuramos a compreensão do processo que culminou na consolidaçãode um novo projeto societário não mais caracterizado pelo caráter agrário exportador, masque se realiza por de uma via de consolidação pelo alto, sem ruptura, marcada pela criaçãode uma racionalidade urbano industrial, mediante uma reforma caracterizada por seucaráter repressor, mas que buscava, sobretudo, impor-se como um novo consenso.

  6. Caracterização química de resíduos da indústria metalúrgica para fins de uso agrícola / Chemical characterization of residues of the metallurgic industry for agricultural use

    Directory of Open Access Journals (Sweden)

    Rafael Montanari

    2008-01-01

    Full Text Available Os órgãos de licenciamento ambiental têm se preocupado de modoespecial com os impactos negativos da aplicação de resíduos industriais no meio ambiente. Dentro desse contexto, realizou-se este trabalho,com o objetivo de se estudar os produtos: escória do forno cubilô(EFC, e resíduos de ciclone do sistema de areia (CSA e do ciclone dos desmoldadores (CD, originados de uma indústria metalúrgica, quanto a sua viabilidade de utilização para fins agrícolas. Esse estudo foi motivado pela preocupação com a possibilidade de contaminação do meio ambiente e também pelo elevado requisito de área para destino final desse resíduo. Os teores de elementos possivelmente tóxicos estão abaixo dos limites estabelecidos pela CETESB, possibilitando, assim, o uso agrícola desses resíduos. Dentre os materiais estudados, apenas o EFC apresentou potencial como corretivo de acidez dos solos. Os três materiais analisados apresentaram potencial de atuar como fontes de micronutrientes às plantas.

  7. Análise de riscos tecnológicos ambientais: perspectivas para o campo da saúde do trabalhador

    Directory of Open Access Journals (Sweden)

    Porto Marcelo Firpo de Souza

    1997-01-01

    Full Text Available O objetivo deste artigo é trazer para o âmbito da saúde pública, particularmente para o campo da Saúde do Trabalhador, questões teóricas e desafios colocados pelos denominados riscos tecnológicos ambientais, os quais se relacionam e ultrapassam o universo dos ambientes de trabalho. Partindo-se dos riscos químicos industriais, demonstra-se a vulnerabilidade das sociedades contemporâneas face aos mesmos e seu agravamento nos países de economia periférica. Em seguida, apresenta-se o escopo das análises de riscos pelas vertentes da engenharia, toxicologia e epidemiologia, bem como a crítica que as ciências sociais vem realizando sobre as mesmas. Conclui-se que a Ciência não é capaz de dar conta isoladamente de problemas complexos como os riscos tecnológicos ambientais. Para se avançar sobre esses limites, diversas propostas integradoras do nível teórico-metodológico vêm sendo desenvolvidas nos campos da análise de riscos e da saúde do trabalhador. Dentre estas, destacam-se aquelas sobre interdisciplinaridade, abordagens sistêmicas e participativas, que incorporam o saber dos trabalhadores e comunidades, forjando a interação entre conhecimento e diálogo como condição fundamental da prevenção e controle dos riscos tecnológicos ambientais.

  8. Different effect of quenching temperature on Fe1+σTe0.5Se0.5 and β-FeSe

    Directory of Open Access Journals (Sweden)

    Zhongnan Guo

    2015-02-01

    Full Text Available In this work, we have demonstrated a different effect on Fe1+σTe0.5Se0.5 and β-FeSe by changing the quenching temperature. Tc is clearly reduced in Fe1+σTe0.5Se0.5 after increasing the quenching temperature from 300 °C to 500 °C, while that of β-FeSe is almost unchanged. Structure refinement indicates that after quenched at 500 °C, FeTe4 tetrahedron exhibits an expansion with the stretched Fe-Te bond, together with the increased amount of interstitial iron. These particular changes on structure are believed to be responsible for the suppression of superconductivity in Fe1+σTe0.5Se0.5.

  9. Structure and properties of ZnSxSe1-x thin films deposited by thermal evaporation of ZnS and ZnSe powder mixtures

    Science.gov (United States)

    Valeev, R. G.; Romanov, E. A.; Vorobiev, V. L.; Mukhgalin, V. V.; Kriventsov, V. V.; Chukavin, A. I.; Robouch, B. V.

    2015-02-01

    Interest to ZnSxSe1-x alloys is due to their band-gap tunability varying S and Se content. Films of ZnSxSe1-x were grown evaporating ZnS and ZnSe powder mixtures onto SiO2, NaCl, Si and ITO substrates using an original low-cost method. X-ray diffraction patterns and Raman spectroscopy, show that the lattice structure of these films is cubic ZnSe-like, as S atoms replace Se and film compositions have their initial S/Se ratio. Optical absorption spectra show that band gap values increase from 2.25 to 3 eV as x increases, in agreement with the literature. Because S atomic radii are smaller than Se, EXAFS spectra confirm that bond distances and Se coordination numbers decrease as the Se content decreases. The strong deviation from linearity of ZnSe coordination numbers in the ZnSxSe1-x indicate that within this ordered crystal structure strong site occupation preferences occur in the distribution of Se and S ions. The behavior is quantitatively confirmed by the strong deviation from the random Bernoulli distribution of the three sight occupation preference coefficients of the strained tetrahedron model. Actually, the ternary ZnSxSe1-x system is a bi-binary (ZnS+ZnSe) alloy with evanescent formation of ternary configurations throughout the x-range.

  10. Laser-induced luminescence of multilayer structures based on polyimides and CdSe and CdSe/ZnS nanocrystals

    International Nuclear Information System (INIS)

    Chistyakov, A A; Dayneko, S V; Zakharchenko, K V; Kolesnikov, V A; Tedoradze, M G; Mochalov, K E; Oleinikov, V A

    2009-01-01

    Laser-induced luminescence of multilayer structures based on the solids of CdSe and CdSe/ZnS nanocrystals, different organic semiconductors and on the layers of organic semiconductors with embedded nanocrystals has been investigated. Drastic decrease of luminescence quantum yield is observed in the films of CdSe nanocrystals on organic semiconductors compared to those on optical glasses. The luminescence of the nanocrystals in the matrices of organic semiconductors and in multilayer structures is shown to be suppressed. The effects observed are explained by the transfer of photogenerated carriers from the nanocrystals to the molecules of organic semiconductors. The presence of the charge transfer is confirmed by a drastic increase in the conductivity (by 2 – 4 orders of magnitude) and in photovoltaic effect at the presence of CdSe and CdSe/ZnS nanocrystals in the structures under investigation. The prospects of using the multilayer structures for development new materials for solar cells are discussed

  11. The MgSeO4-UO2SeO4-H2O system at 25 deg C

    International Nuclear Information System (INIS)

    Serezhkina, L.B.; Serezhkin, V.N.

    1984-01-01

    The method of isothermal solubility at 25 deg C has been used to study MgSeO 4 -UO 2 SeO 4 -H 2 O system. Formation of the new compound Mg 2 (UO 2 ) 3 (SeO 4 ) 5 X32H 2 O, congruently soluble in water is stated. Thermographic and X-ray diffraction investigations of the prepared magnesium selenato-uranylate and products of its dehydration are conducted

  12. OS CENTROS LOGÍSTICOS E INDUSTRIAIS ADUANEIROS E A INTEGRAÇÃO TERRITORIAL NO ESTADO DE SÃO PAULO

    Directory of Open Access Journals (Sweden)

    Lucas Ferreira Rosa Penha

    2009-12-01

    Full Text Available De agosto a dezembro de 2006 esteve em vigência uma medida provisória que alterava os procedimentos de criação de estações aduaneiras em zona secundária (portos secos e criava, assim, uma nova categoria de recinto aduaneiro: o Centro Logístico e Industrial Aduaneiro (CLIA. São armazéns alfandegados onde se realizam os procedimentos de desembaraço aduaneiro na importação e exportação de mercadorias, entretanto, não estão localizados nas zonas de portos e aeroportos (zona primária. A medida estabeleu uma “liberalização” do setor ao transferir a iniciativa da criação destes recintos à esfera privada quando até então era de encargo exclusivo da Receita Federal, por meio de processos licitatórios. Trata-se de objetos geográficos com densidades técnicas e normativas que firmam-se como alternativa aos portos e aeroportos para os procedimentos de desembaraço aduaneiro. O presente trabalho pretende entender as implicações territoriais destas novas estruturas no estado de São Paulo, em um período caracterizado pela dispersão e dissolução do processo produtivo e pela crescente importância da circulação dentro deste.

  13. Local structure and defect chemistry of [(SnSe)1.15]m(TaSe2) ferecrystals – A new type of layered intergrowth compound

    International Nuclear Information System (INIS)

    Grosse, Corinna; Atkins, Ryan; Kirmse, Holm; Mogilatenko, Anna; Neumann, Wolfgang; Johnson, David C.

    2013-01-01

    Highlights: •The crystal structure of [(SnSe) 1.15 ] m (TaSe 2 ) ferecrystals was analyzed by TEM. •The layers exhibit turbostratic disorder, but we also observed a local ordering. •The structures of the SnSe and TaSe 2 layers are similar to binary SnSe and 2H-TaSe 2 . •An increasing in-plane SnSe grain size with increasing m was observed. •Defect areas with missing, substituted or additional layers were found. -- Abstract: The atomic structure of the family of ferecrystals [(SnSe) 1.15 ] m (TaSe 2 ) (m = 1, 3, and 6) was investigated by means of transmission electron microscopy. The tantalum in the TaSe 2 layers was observed to have trigonal prismatic coordination similar to that found in the 2H polytype of bulk TaSe 2 . The structure of the SnSe constituent was found to be similar to that of orthorhombic α-SnSe. In the compounds with m = 1 and m = 3, regions with a local ordering of the layers along a commensurate axis, similar to the ordering in conventional misfit layer compounds, were observed. However, on a longer range the ferecrystals were found to exhibit a turbostratically disordered structure. Stacking defects were occasionally found in the samples in which a layer is interrupted and the surrounding layers are bent around these defects, while maintaining abrupt interfaces instead of interdiffusing. Volume defects were found in one sample of [(SnSe) 1.15 ] 1 (TaSe 2 ) 1 in which a SnSe layer locally substitutes a part of a TaSe 2 layer without interrupting the surrounding layers

  14. Composition-controlled optical properties of colloidal CdSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Ayele, Delele Worku [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Department of Chemistry, Bahir Dar University, Bahir Dar (Ethiopia); Su, Wei-Nien, E-mail: wsu@mail.ntust.edu.tw [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Chou, Hung-Lung [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Pan, Chun-Jern [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Hwang, Bing-Joe, E-mail: bjh@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China)

    2014-12-15

    Graphical abstract: - Highlights: • The surface of CdSe QDs are modified with cadmium followed by selenium. • The optical properties of CdSe QDs can be controlled by manipulating the composition. • Surface compositional change affects the surface defects or traps and recombination. • The surface trapping state can be controlled by tuning the surface composition. • A change in composition shows a change in the carrier life time. - Abstract: A strategy with respect to band gap engineering by controlling the composition of CdSe quantum dots (QDs) is reported. After the CdSe QDs are prepared, their compositions can be effectively manipulated from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich QDs. To obtain Cd-rich CdSe QDs, Cd was deposited on equimolar CdSe QDs. Further deposition of Se on Cd-rich CdSe QDs produced Se-rich CdSe QDs. The compositions (Cd:Se) of the as-prepared CdSe quantum dots were acquired by Energy-dispersive X-ray spectroscopy (EDX). By changing the composition, the overall optical properties of the CdSe QDs can be manipulated. It was found that as the composition of the QDs changes from 1:1 (Cd:Se) CdSe to Cd-rich and then Se-rich CdSe, the band gap decreases along with a red shift of UV–vis absorption edges and photoluminescence (PL) peaks. The quantum yield also decreases with surface composition from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich, largely due to the changes in the surface state. Because of the involvement of the surface defect or trapping state, the carrier life time increased from the 1:1 (Cd:Se) CdSe QDs to the Cd-rich to the Se-rich CdSe QDs. We have shown that the optical properties of CdSe QDs can be controlled by manipulating the composition of the surface atoms. This strategy can potentially be extended to other semiconductor nanocrystals to modify their properties.

  15. Composition-controlled optical properties of colloidal CdSe quantum dots

    International Nuclear Information System (INIS)

    Ayele, Delele Worku; Su, Wei-Nien; Chou, Hung-Lung; Pan, Chun-Jern; Hwang, Bing-Joe

    2014-01-01

    Graphical abstract: - Highlights: • The surface of CdSe QDs are modified with cadmium followed by selenium. • The optical properties of CdSe QDs can be controlled by manipulating the composition. • Surface compositional change affects the surface defects or traps and recombination. • The surface trapping state can be controlled by tuning the surface composition. • A change in composition shows a change in the carrier life time. - Abstract: A strategy with respect to band gap engineering by controlling the composition of CdSe quantum dots (QDs) is reported. After the CdSe QDs are prepared, their compositions can be effectively manipulated from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich QDs. To obtain Cd-rich CdSe QDs, Cd was deposited on equimolar CdSe QDs. Further deposition of Se on Cd-rich CdSe QDs produced Se-rich CdSe QDs. The compositions (Cd:Se) of the as-prepared CdSe quantum dots were acquired by Energy-dispersive X-ray spectroscopy (EDX). By changing the composition, the overall optical properties of the CdSe QDs can be manipulated. It was found that as the composition of the QDs changes from 1:1 (Cd:Se) CdSe to Cd-rich and then Se-rich CdSe, the band gap decreases along with a red shift of UV–vis absorption edges and photoluminescence (PL) peaks. The quantum yield also decreases with surface composition from 1:1 (Cd:Se) CdSe QDs to Cd-rich and then to Se-rich, largely due to the changes in the surface state. Because of the involvement of the surface defect or trapping state, the carrier life time increased from the 1:1 (Cd:Se) CdSe QDs to the Cd-rich to the Se-rich CdSe QDs. We have shown that the optical properties of CdSe QDs can be controlled by manipulating the composition of the surface atoms. This strategy can potentially be extended to other semiconductor nanocrystals to modify their properties

  16. PbSe Nanocrystal Excitonic Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2009-11-11

    We report the design, fabrication, and characterization of colloidal PbSe nanocrystal (NC)-based photovoltaic test structures that exhibit an excitonic solar cell mechanism. Charge extraction from the NC active layer is driven by a photoinduced chemical potential energy gradient at the nanostructured heterojunction. By minimizing perturbation to PbSe NC energy levels and thereby gaining insight into the "intrinsic" photovoltaic properties and charge transfer mechanism of PbSe NC, we show a direct correlation between interfacial energy level offsets and photovoltaic device performance. Size dependent PbSe NC energy levels were determined by cyclic voltammetry and optical spectroscopy and correlated to photovoltaic measurements. Photovoltaic test structures were fabricated from PbSe NC films sandwiched between layers of ZnO nanoparticles and PEDOT:PSS as electron and hole transporting elements, respectively. The device current-voltage characteristics suggest a charge separation mechanism that Is distinct from previously reported Schottky devices and consistent with signatures of excitonic solar cells. Remarkably, despite the limitation of planar junction structure, and without film thickness optimization, the best performing device shows a 1-sun power conversion efficiency of 3.4%, ranking among the highest performing NC-based solar cells reported to date. © 2009 American Chemical Society.

  17. Ultra-thin ZnSe: Anisotropic and flexible crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Bacaksiz, C., E-mail: cihanbacaksiz@iyte.edu.tr [Department of Physics, Izmir Institute of Technology, 35430 Izmir (Turkey); Senger, R.T. [Department of Physics, Izmir Institute of Technology, 35430 Izmir (Turkey); Sahin, H. [Department of Photonics, Izmir Institute of Technology, 35430 Izmir (Turkey)

    2017-07-01

    Highlights: • Ultra-thin ZnSe is dynamically stable. • Ultra-thin ZnSe is electronically direct-gap semiconductor. • Ultra-thin ZnSe is ultra-flexible. • Ultra-thin ZnSe is mechanically in-plane anisotropic. - Abstract: By performing density functional theory-based calculations, we investigate the structural, electronic, and mechanical properties of the thinnest ever ZnSe crystal . The vibrational spectrum analysis reveals that the monolayer ZnSe is dynamically stable and has flexible nature with its soft phonon modes. In addition, a direct electronic band gap is found at the gamma point for the monolayer structure of ZnSe. We also elucidate that the monolayer ZnSe has angle dependent in-plane elastic parameters. In particular, the in-plane stiffness values are found to be 2.07 and 6.89 N/m for the arm-chair and zig-zag directions, respectively. The angle dependency is also valid for the Poisson ratio of the monolayer ZnSe. More significantly, the in-plane stiffness of the monolayer ZnSe is the one-tenth of Young modulus of bulk zb-ZnSe which indicates that the monolayer ZnSe is a quite flexible single layer crystal. With its flexible nature and in-plane anisotropic mechanical properties, the monolayer ZnSe is a good candidate for nanoscale mechanical applications.

  18. Ultra-thin ZnSe: Anisotropic and flexible crystal structure

    International Nuclear Information System (INIS)

    Bacaksiz, C.; Senger, R.T.; Sahin, H.

    2017-01-01

    Highlights: • Ultra-thin ZnSe is dynamically stable. • Ultra-thin ZnSe is electronically direct-gap semiconductor. • Ultra-thin ZnSe is ultra-flexible. • Ultra-thin ZnSe is mechanically in-plane anisotropic. - Abstract: By performing density functional theory-based calculations, we investigate the structural, electronic, and mechanical properties of the thinnest ever ZnSe crystal . The vibrational spectrum analysis reveals that the monolayer ZnSe is dynamically stable and has flexible nature with its soft phonon modes. In addition, a direct electronic band gap is found at the gamma point for the monolayer structure of ZnSe. We also elucidate that the monolayer ZnSe has angle dependent in-plane elastic parameters. In particular, the in-plane stiffness values are found to be 2.07 and 6.89 N/m for the arm-chair and zig-zag directions, respectively. The angle dependency is also valid for the Poisson ratio of the monolayer ZnSe. More significantly, the in-plane stiffness of the monolayer ZnSe is the one-tenth of Young modulus of bulk zb-ZnSe which indicates that the monolayer ZnSe is a quite flexible single layer crystal. With its flexible nature and in-plane anisotropic mechanical properties, the monolayer ZnSe is a good candidate for nanoscale mechanical applications.

  19. Wide emission-tunable CdTeSe/ZnSe/ZnS core–shell quantum dots and their conjugation with E. coli O-157

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Haifeng [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Zhou, Guangjun, E-mail: gjzhou@sdu.edu.cn [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Zhou, Juan [Center for Disease Control and Prevention of Jinan Military Command, Jinan 250014 (China); Xu, Dong; Zhang, Xingshuang; Kong, Peng; Yang, Zhongsen [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China)

    2015-05-15

    Highlights: • QDs with variety morphology were obtained via an injection controlled process. • 3-D PL spectra of core–shell QDs show different excitation wavelength dependence. • The PL intensity of QDs with ZnSe transition layer increases dramatically. • Core–shell QDs were processed into aqueous phase and conjugated with E. coli O-157. - Abstract: Wide emission-tunable and different morphological alloyed CdTeSe quantum dots (QDs), CdTeSe/ZnS and CdTeSe/ZnSe/ZnS core–shell QDs were successfully synthesized via an injection controlled process. The effect of injection procedure and reaction temperature were systematically discussed and the growth mechanism was proposed. Most efficient PL wavelength was correlated with reaction time and temperature. The 3-D PL spectra of spherical bare CdTeSe and core–shell QDs with different passivation showed different excitation wavelength dependency. The PL intensity of CdTeSe/ZnSe/ZnS core–shell QDs increased greatly in comparison with that of CdTeSe and CdTeSe/ZnSe QDs. ZnSe transition layer played an important role in improving the PL intensity by providing a smoothened interface and gradient band offsets. The core–shell QDs were transferred into aqueous phase and successfully conjugated with Escherichia coli O-157. The proposed phase-transfer and bio-labeling strategy may be applicable to various QDs with different compositions.

  20. Estratégias competitivas e competências essenciais: perspectivas para a internacionalização da indústria no Brasil

    Directory of Open Access Journals (Sweden)

    Fleury Afonso C. C.

    2003-01-01

    Full Text Available Uma das principais características da nova economia é a transição da eficiência individual para a eficiência coletiva. A competitividade é, e será cada vez mais, relacionada ao desempenho de redes interorganizacionais e não de empresas isoladas. Ao mesmo tempo, a formação dessas redes tem forte dimens��o locacional, associada ao movimento de internacionalização das operações das grandes corporações transnacionais. Do ponto de vista de economias emergentes como a brasileira, importantes mudanças estão tendo lugar, como conseqüência do posicionamento de suas empresas nessas novas redes interorganizacionais internacionais. Este é o foco deste estudo. Um modelo analítico foi desenvolvido para a avaliação de quais setores industriais apresentam potencial para se tornarem competitivos internacionalmente, por demonstrarem possuir as competências organizacionais necessárias. O referencial conceitual foi construído a partir da idéia de que a participação numa rede interorganizacional depende das competências organizacionais desenvolvidas pela empresa e que essa participação vai implicar mudanças na definição de sua estratégia competitiva. A aplicação do modelo foi operacionalizada em um amplo survey da indústria no país. Os resultados permitem realizar uma primeira identificação do posicionamento das empresas em redes internacionais assim como avaliar a competitividade em seus diferentes setores industriais.

  1. Complexation in the system K2SeO4-UO2SeO4-H2O

    International Nuclear Information System (INIS)

    Serezhkina, L.B.; Kuchumova, N.V.; Serezhkin, V.N.

    1994-01-01

    Complexation in the system K 2 SeO 4 -UO 2 SeO 4 -H 2 O at 25 degrees C is studied by isothermal solubility. Congruently soluble K 2 UO 2 (SeO 4 ) 2 ·4H 2 O (I) and incongruently soluble K 2 (UO 2 ) 2 (SeO 4 ) 3 ·6H 2 O (II) are observed. The unit-cell constants of I and II are determined from an X-ray diffraction investigation. For I, a = 12,969, b = 11.588, c = 8.533 angstrom, Z = 4, space group Pmmb. For II, a = 23.36, b = 6.784, c = 13.699 angstrom, β = 104.42 degrees, Z = 4, space group P2/m, P2, or Pm. Complexes I and II are representatives of the crystal-chemical groups AB 2 2 M 1 and A 2 T 3 3 M 1 , respectively, of uranyl complexes

  2. INTERNET OF THINGS (IOT: UM CENÁRIO GUIADO POR PATENTES INDUSTRIAIS

    Directory of Open Access Journals (Sweden)

    Givaldo Almeida Santos

    2015-12-01

    Full Text Available A Internet of Things (IoT ou Internet das Coisas é destaque no cenário global e tem proporcionado o desenvolvimento de interessantes aplicações de georreferenciamento, identificação de pessoas, rastreamento de objetos, sistemas de segurança e automação de processos. Essas aplicações quando se apropriam da tecnologia de IoT amplificam o potencial das inovações em produtos e serviços, as vezes condicionando outros significados para interações homem-máquina. A combinação da IoT com a Bio e Nanotecnologia, sensores eletrônicos (RFID e RSSF, smartphones e sistemas embarcados inteligentes, pode motivar as microempresas e Startups a desenvolverem novas tecnologias que aquecem a economia mundial. Sendo assim, a pesquisa exploratória proposta nesse estudo contou com uma prospecção de pedidos de patentes de IoT e demonstrou que a China e Estados Unidos são os maiores depositantes de patentes, e ainda que investimentos em PD&I com a tecnologia da IoT são pequenos nos demais países, principalmente no Brasil. Os resultados alcançados também indicam que a IoT pode ser aplicada em projetos de governança e desenvolvimento de sistemas de automação autônomos para controle e monitoramento do consumo racional de recursos naturais não renováveis em cidades inteligentes, e dessa forma prover soluções inovadoras para problemas urbanos, criando novas oportunidades de negócios que podem oferecer um diferencial significativo para o mercado consumidor quando for possível utilizar essa tecnologia disruptiva em escala industrial.

  3. Origin of low thermal conductivity in SnSe

    Science.gov (United States)

    Xiao, Yu; Chang, Cheng; Pei, Yanling; Wu, Di; Peng, Kunling; Zhou, Xiaoyuan; Gong, Shengkai; He, Jiaqing; Zhang, Yongsheng; Zeng, Zhi; Zhao, Li-Dong

    2016-09-01

    We provide direct evidence to understand the origin of low thermal conductivity of SnSe using elastic measurements. Compared to state-of-the-art lead chalcogenides Pb Q (Q =Te , Se, S), SnSe exhibits low values of sound velocity (˜1420 m /s ) , Young's modulus (E ˜27.7 GPa ) , and shear modulus (G ˜9.6 GPa ) , which are ascribed to the extremely weak Sn-Se atomic interactions (or bonds between layers); meanwhile, the deduced average Grüneisen parameter γ of SnSe is as large as ˜3.13, originating from the strong anharmonicity of the bonding arrangement. The calculated phonon mean free path (l ˜ 0.84 nm) at 300 K is comparable to the lattice parameters of SnSe, indicating little room is left for further reduction of the thermal conductivity through introducing nanoscale microstructures and microscale grain boundaries. The low elastic properties indicate that the weak chemical bonding stiffness of SnSe generally causes phonon modes softening which eventually slows down phonon propagation. This work provides insightful data to understand the low lattice thermal conductivity of SnSe.

  4. O técnico de escolaridade média no setor produtivo: seu novo lugar e suas competências The secondary school technician in the productive sector: his new place and competences

    Directory of Open Access Journals (Sweden)

    João Bosco Laudares

    2003-12-01

    Full Text Available Os convênios recentes estabelecidos entre os Centros de Formação Profissional e as grandes indústrias empregadoras de profissionais técnicos, de nível médio, parecem indicar uma realocação desses profissionais na estrutura de produção. A posição intermediária, entre os operários e os engenheiros ou entre o "chão de fabrica" e o "escritório de projeto", típica da gestão taylorista, tende ao desaparecimento na gestão horizontalizada dos novos modelos organizacionais. A proximidade desses profissionais com os engenheiros passa a demandar deles um nível mais elevado de qualificação, como atesta o aumento da demanda dos setores produtivos industriais de tecnólogos, profissionais de nível superior. Recorre-se à sociologia do trabalho e às noções construídas por ela, de qualificação, de competência e de saber, como forma de se identificar as tendências de mobilidade profissional dos técnicos e dos tecnólogos no interior de grandes empresas industriais.The recent agreements between the Professional Training Centers (at high-school levels and large industries suggest a new position is given to these professionals in the production structure. Their intermediate position between workers and engineers or between "the factory floor" and the "planning department", typical of taylorism, tends to disappear from the horizontal management of the new organizational models. This leads them to need higher levels of qualification, closer to those of engineers, which is proved by the increasing demand of technologists, professionals of superior level, in the productive sector. Drawing on Sociology of Work and its notions of qualification, competence and knowledge, we seek to identify the tendencies of professional mobility of both technicians and technologists in large industries.

  5. Fatores críticos para a melhoria contínua em indústrias brasileiras Critical factors for the continuous improvement in brazilian manufacturing companies

    Directory of Open Access Journals (Sweden)

    Pedro Carlos Oprime

    2011-03-01

    Full Text Available O objetivo deste artigo é identificar e analisar fatores críticos no desenvolvimento de atividades de melhoria contínua (MC em empresas industriais brasileiras. Um modelo conceitual de relacionamento entre práticas e resultados foi testado por meio de um survey utilizando uma amostra de 46 empresas industriais. Fatores como: treinamento em ferramentas de solução de problemas, o incentivo a sugestões, a comunicação face a face, visitas ao chão de fábrica e adoção de sistemas de incentivos, se mostraram críticos para alcance de sucesso em atividades de MC. Identificaram pela análise fatorial dois constructos críticos relacionados ao processo de melhoria contínua: 1 a promoção das atividades de melhoria contínua por meio de políticas de incentivos; e 2 o suporte e liderança da alta administração e ativa participação da gerência. Observou-se que há relação estatisticamente significativa entre o uso de técnicas de solução de problemas e mecanismos de incentivos com o desempenho das empresas.The aim of this paper is to identify and analyze critical factors in the development of continuous improvement (CI activities in Brazilian manufacturing companies. A conceptual model of relationship between practices and results was tested through a survey conducted in 46 manufacturing companies. Factors such as: problems solving tools training, suggestion incentives, face-to-face communication, visits to the shop floor and adoption of incentive systems, have proved to be critical at reaching success in CI activities. Through factorial analysis, two critical constructs concerning continuous improvement process were identified: 1 promotion of continuous improvement through incentive mechanisms; and 2 High level management support and leadership and management active involvement. It was observed that there is a statistically meaningful relationship between the use of problem solving techniques and the incentive mechanisms in face of

  6. Attempting to realize n-type BiCuSeO

    Science.gov (United States)

    Zhang, Xiaoxuan; Feng, Dan; He, Jiaqing; Zhao, Li-Dong

    2018-02-01

    As an intrinsic p-type semiconductor, BiCuSeO has been widely researched in the thermoelectric community, however, n-type BiCuSeO has not been reported so far. In this work, we successfully realized n-type BiCuSeO through carrying out several successive efforts. Seebeck coefficient of BiCuSeO was increased through introducing extra Bi/Cu to fill the Bi/Cu vacancies that may produce holes, and the maximum Seebeck coefficient was increase from +447 μVK-1 for undoped BiCuSeO to +638 μVK-1 for Bi1.04Cu1.05SeO. The Seebeck coefficient of Bi1.04Cu1.05SeO was changed from p-type to n-type through electron doping through introducing Br/I in Se sites, the maximum negative Seebeck coefficient can reach ∼ -465 μVK-1 and -543 μVK-1 for Bi1.04Cu1.05Se1-xIxO and Bi1.04Cu1.05Se1-xBrxO, respectively. Then, after compositing Bi1.04Cu1.05Se0.99Br0.01O with Ag, n-type BiCuSeO can be absolutely obtained in the whole temperature range of 300-873 K, the maximum ZT 0.05 was achieved at 475 K in the Bi1.04Cu1.05Se0.99Br0.01O+15% Ag. Our report indicates that it is possible to realize n-type conducting behaviors in BiCuSeO system.

  7. Immobilization of Se and U by iron sulfides

    International Nuclear Information System (INIS)

    Kang Mingliang; Ma Bin; Yang Zhuanwei; Liu Chunli; Chen Fanrong

    2014-01-01

    Both uranium and selenium are redox-sensitive, and can occur in several oxidation states. In reducing environments, they exist as insoluble forms. Therefore, reductive precipitation is the most effective way to immobilize U and Se. The interaction of aqueous Se (IV) and uranylwithiron sulfidesweresystematically investigated in light of thermodynamic calculations, X-ray Absorption Spectroscopy (XAS), and X-ray Photoelectron Spectroscopy (XPS). The results from the speciation study revealed that the reduction product was Se (O) when natural pyrite and pyrrhotitereacted with Se (IV), although FeSe 2 is the thermodynamically predicted product from nearly neural to alkaline conditions. This discrepancy is attributed to the oxidizing ability of Se (IV) towards FeSe 2 , of which produce the insoluble Se (0) as the stable product in short-term experiments. In contrast to the thermodynamic calculations, with a reaction product of mixed U (IV) and U (VI) (e.g., U 3 O 8 ), redox reaction was observed only at pH ∼ 8.5 and ∼ 4.5 for U (VI) reduction by nanosized pyrite and natural pyrite, respectively. We proposed that oxidation of pyrite needs an intermediate (e.g., Fe 2+ ), and the reaction between the uranyl and the intermediate is thermodynamically or kinetically limited. Moreover, trace elements generally held within pyrite structure can also greatly influence its reactivity. This study demonstrated that reaction kinetics play a significant role on the reaction product. From a geological time scale, Se and U are likely to be immobilized by iron sulfides via the form of FeSe 2 and UO 2 . (authors)

  8. Chemical and structural evolution in the Th-SeO3(2-)/SeO4(2-) system: from simple selenites to cluster-based selenate compounds.

    Science.gov (United States)

    Xiao, Bin; Langer, Eike; Dellen, Jakob; Schlenz, Hartmut; Bosbach, Dirk; Suleimanov, Evgeny V; Alekseev, Evgeny V

    2015-03-16

    While extensive success has been gained in the structural chemistry of the U-Se system, the synthesis and characterization of Th-based Se structures are widely unexplored. Here, four new Th-Se compounds, α-Th(SeO3)2, β-Th(SeO3)2, Th(Se2O5)2, and Th3O2(OH)2(SeO4)3, have been obtained from mild hydrothermal or low-temperature (180-220 °C) flux conditions and were subsequently structurally and spectroscopically characterized. The crystal structures of α-Th(SeO3)2 and β-Th(SeO3)2 are based on ThO8 and SeO3 polyhedra, respectively, featuring a three-dimensional (3D) network with selenite anions filling in the Th channels along the a axis. Th(Se2O5)2 is a 3D framework composed of isolated ThO8 polyhedra interconnected by [Se2O5](2-) dimers. Th3O2(OH)2(SeO4)3 is also a 3D framework constructed by octahedral hexathorium clusters [Th6(μ3-O)4(μ3-OH)4](12+), which are interlinked by selenate groups SeO4(2-). The positions of the vibrational modes associated with both Se(IV)O3(2-) and Se(VI)O4(2-) units, respectively, were determined for four compounds, and the Raman spectra of α- and β-Th(SeO3)2 are compared and discussed in detail.

  9. 79Se: geochemical and crystallo-chemical retardation mechanisms

    International Nuclear Information System (INIS)

    Chen, F.; Ewing, R.C.

    1999-01-01

    79 Se is a long-lived (1.1 x 10 6 yrs) fission product which is chemically and radiologically toxic. Under Eh-pH conditions typical of oxidative alteration of spent nuclear fuel, selenite, SeO 3 2- or HSeO 3 - or selenate, SeO 4 2- , are the dominant aqueous species of selenium. Because of the high solubility of metal-selenites and metal-selenates and the low adsorption of selenite and selenate aqueous species by geological materials under alkaline conditions, selenium may be highly mobile. However, 79 Se released from altered fuel may become immobilized by incorporation into secondary uranyl phases as low concentration impurities, and this may significantly reduce the mobility of selenium. Analysis and comparison of the known structures of uranyl phases indicate that (SeO 3 ) may substitute for (SiO 3 OH) in structures of α-uranophane and boltwoodite that are expected to be the dominant alteration products of UO 2 in Si-rich groundwater. The substitutions (SeO 3 ) (SiO 3 OH) in sklodowskite, Mg[(UO 2 )(SiO 3 OH)] 2 (H 2 O) 6 and (SeO 3 ) (PO 4 ) in phurcalite, Ca 2 [(UO 2 ) 3 (PO 4 ) 2 O 2 ](H 2 O) 7 , may occur with the eliminated apical anion being substituted for by an H 2 O group, but experimental investigation is required. The close similarity between the sheets in the structures of rutherfordine, [(UO 2 )(CO 3 )] and [(UO 2 )(SeO 3 )] implies that the substitution (SeO 3 ) (CO 3 ) can occur in rutherfordine, and possibly other uranyl carbonates. However, the substitutions: (SeO 3 ) (SiO 4 ) in soddyite and (SeO 3 ) (PO 4 ) in phosphuranylite may disrupt their structural connectivity and are, therefore, unlikely. (orig.)

  10. Exotic topological insulator states and topological phase transitions in Sb2Se3-Bi2Se3 heterostructures

    KAUST Repository

    Zhang, Qianfan

    2012-03-27

    Topological insulator is a new state of matter attracting tremendous interest due to its gapless linear dispersion and spin momentum locking topological states located near the surface. Heterostructures, which have traditionally been powerful in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb 2Se 3-Bi 2Se 3 heterostructures by first-principle simulation and discovered that an exotic topological state exists. Surprisingly, the state migrates from the nontrivial Bi 2Se 3 into the trivial Sb 2Se 3 region and spreads across the entire Sb 2Se 3 slab, extending beyond the concept of "surface" state while preserving all of the topological surface state characteristics. This unusual topological state arises from the coupling between different materials and the modification of electronic structure near Fermi energy. Our study demonstrates that heterostructures can open up opportunities for controlling the real-space distribution of the topological state and inducing quantum phase transitions between topologically trivial and nontrivial states. © 2012 American Chemical Society.

  11. Formation and properties of epitaxial CdSe, ZnSe quantum dots. Conventional molecular beam epitaxy and related techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, Suddhasatta

    2008-01-16

    This thesis systematically investigates three such alternative approaches, along with conventional MBE, with emphasis on the formation-mechanism of QDs, and optimization of their morphological and optical attributes. it is shown here that no distinct 3D islands are formed in MBE growth of CdSe on ZnSe. While CdSe heteroepitaxy occurs in the multilayer-mode at T{sub G}=300 C, a reentrant recovery of the layer-by-layer mode is reported in this thesis, for growth at T{sub G}<{proportional_to}240 C. In the second variant technique, formation of large and distinct islands is demonstrated by deposition of amorphous selenium (a-Se) onto a 2D CdSe epilayer at room temperature and its subsequent desorption at a higher temperature (T{sub D}=230 C). The process steps of the third variant technique, developed in course of this work, are very similar to those of the previous one-the only alteration being the substitution of selenium with tellurium as the cap-forming-material. (orig.)

  12. In-situ XRD study of alloyed Cu2ZnSnSe4-CuInSe2 thin films for solar cells

    International Nuclear Information System (INIS)

    Hartnauer, Stefan; Wägele, Leonard A.; Jarzembowski, Enrico; Scheer, Roland

    2015-01-01

    We investigate the growth of Cu 2 ZnSnSe 4 -CuInSe 2 (CZTISe) thin films using a 2-stage (Cu-rich/Cu-free) co-evaporation process under simultaneous application of in-situ angle dispersive X-ray diffraction (XRD). In-situ XRD allows monitoring the phase formation during preparation. A variation of the content of indium in CZTISe leads to a change in the lattice constant. Single phase CZTISe is formed in a wide range, while at high In contents a phase separation is detected. Because of different thermal expansion coefficients, the X-ray diffraction peaks of ZnSe and CZTISe can be distinguished at elevated substrate temperatures. The formation of ZnSe appears to be inhibited even for low indium content. In-situ XRD shows no detectable sign for the formation of ZnSe. First solar cells of CZTISe have been prepared and show comparable performance to CZTSe. - Highlights: • In-situ XRD study of two-stage co-evaporated Cu 2 ZnSnSe 4 -CuInSe 2 alloyed thin films. • No detection of ZnSe with in-situ XRD due to Indium incorporation • Comparable efficiency of alloyed solar cells

  13. Lattice thermal conductivity of LaSe

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei, E-mail: tolwwt@163.com [School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Pan, Zhong-liang; Chen, Jun-fang; He, Qin-yu [School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Wang, Teng [School of Computer, South China Normal University, 510631 Guangzhou (China)

    2015-07-15

    The phonon dispersions and phonon density of states of LaSe are obtained, based on density functional perturbation theory and the norm-conserving pseudo-potential method. An anomaly in calculated phonon dispersion curves is presented and interpreted as a Kohn anomaly. The heat capacity of LaSe is calculated then. For the three-phonon process scattering, the lowest non-harmonic cubic terms of the interatomic potential are considered to obtain single-phonon relaxation rate by applying the Fermi's golden rule. For the boundary scattering, the average phonon relaxation time was obtained. Considering two kinds of phonon scattering mechanisms, we obtain the lattice thermal conductivity of LaSe.

  14. In situ observation of the formation of FeSe

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Wulff, Anders Christian; Yue, Zhao

    2011-01-01

    The formation of the FeSe compound from a mixture of Fe and Se powders encased in a composite Cu/Nb sheath was studied in situ by means of high-energy synchrotron x-ray diffraction. Tetragonal beta-FeSe does not seem to form directly from the starting elements. Instead, a sequence of FeSe2, Fe3Se...

  15. Histotopography of the radiopharmaceuticals 75Se-selenomethionine and 75Se-selenite in critical organs of adult and embryonic mice

    International Nuclear Information System (INIS)

    Khant, S.E.; Norets, T.A.

    1981-01-01

    Adult male and pregnant mice received 75 Se-labelled methionine and selenite, resp. The critical organs and the embryos were examined histoautoradiographically at different time intervals as to the organ distribution of the radiopharmaceuticals. All organs revealed a heterogeneity of the 75 Se distribution with an intensity being unequally organo-specific and depending on the type of the radiopharmaceutical. 75 Se-selenomethionine was deposited mainly in functional areas of kidneys, liver, bone marrow and testes thus causing a long-term retention and an intensive irradiation of these organs. In the embryos 75 Se-seleno-methionine was distributed unequally preferring liver, hematopoietic areas of the bone marrow and the lens

  16. Influence of defect structure on magnetic and electronic properties of Hg1-x Crx Se and Hg1-x Cox Se

    International Nuclear Information System (INIS)

    Prozorovskij, V.D.; Reshidova, I.Yu.; Puzynya, A.I.; Paranchich, Yu.S.

    1996-01-01

    The results of experimental investigations of the Shubnikov-de Haas oscillations at superhigh frequencies, electron spin resonance, magnetic susceptibility, relaxation dielectric losses, and galvanomagnetic measurements in the Hg 1-x Cr x Se and Hg 1-x Co x Se single crystal samples are presented. Analysis of the results Hg 1-x Cr x Se and Hg 1-x Co x Se depend on the defect structure of the substance and the type of defects making this structure. The manifestation of critical phenomena in Hg 1-x Cr x Se also depends on the defect structure

  17. Ectrópio palpebral em portador da síndrome de Down e conjuntivite alérgica: relato de caso Eyelid ectropion in Down's syndrome related to allergic conjunctivitis: case report

    Directory of Open Access Journals (Sweden)

    Claudia Akemi Shiratori

    2007-08-01

    Full Text Available Relata-se o caso de paciente com síndrome de Down, portador de importante ectrópio mecânico da pálpebra inferior, relacionado com conjuntivite alérgica, catarata e ceratocone. Foi feito tratamento cirúrgico, empregando a técnica de "tarsal strip" e ressecção da lamela posterior que estava redundante e espessa, com bom resultado estético e funcional.This is a case report of a patient with Down's syndrome with an important mechanical ectropion and elongation of the lower lid related to chronic allergic conjunctivitis, besides cataract and keratoconus. The tarsal strip technique and ressection of redundant and thick conjunctiva was the surgical approach chosen for this case. Functional and cosmetic outcomes were considered satisfactory.

  18. Solving the shape conundrum in $^{70}$Se

    CERN Multimedia

    We propose a multi-step Coulomb-excitation study of $^{70}$Se at HIE-ISOLDE using the $^{208}$Pb( $^{70}$Se, $^{70}$Se*)$^{208}$Pb* reaction at a safe energy of 5.0 MeV/u. We aim at a precise measurement of the $\\left \\langle 2^{+}_{1} \\hspace{0.1cm} || \\hspace{0.1cm}\\hat{E}2 \\hspace{0.1cm} || \\hspace{0.1cm}2^{+}_{ 1} \\right \\rangle$ diagonal matrix element as well as gaining information on additional matrix elements. Such information will shed light onto the shape conundrum of the 2$^{+}_{1}$ state in $^{70}$Se as well as foreseeing the opportunity for a more detailed understanding of the shape-coexistence phenomenon in this region.

  19. Novel red-emission of ternary ZnCdSe semiconductor nanocrystals

    Science.gov (United States)

    Chung, Shu-Ru; Wang, Kuan-Wen; Chen, Hong-Shuo; Chen, Hong-Hong

    2015-02-01

    The effect of chain lengths of fatty acids on the physical properties of CdSe and ZnCdSe semiconductor nanocrystals (NCs) synthesized by the colloidal chemistry procedure is investigated. The fatty acids, lauric acid (LA), and stearic acid (SA), with different lengths of carbon chains, are used to prepare CdSe and ZnCdSe NCs when hexyldecylamine (HDA) is applied as the sole surfactant. For CdSe-SA and ZnCdSe-SA, they have the same emission wavelength at 592 nm and the same particle size of 3.3 nm; however, their quantum yield (QY) is 75 and 16 %, respectively. In contrast, the emission wavelength of CdSe-LA and ZnCdSe-LA NCs is 609 and 615 nm, the particle size is about 3.5 and 4 nm under the same reaction time, and the QY of them are 33 and 59 %, respectively. The X-ray diffraction pattern shows that ZnCdSe NCs all have the wurtzite structure, and their main peaks are located between those of pure CdSe and ZnSe materials. The main phase of ZnCdSe-SA and ZnCdSe-LA is ZnSe and CdSe, respectively, implying that alloyed ZnCdSe NC can be prepared and ZnSe and CdSe phase can be promoted by SA and LA, respectively. Moreover, the QY of red-emission ZnCdSe-LA is higher than 50 %. These results suggest that the growth rate of CdSe as well as ZnCdSe NC can be enhanced by using LA as complex reagent and HDA as sole surfactant. It is expected that the reported effective synthetic strategy can be developed as a very practical, easy and not time-consuming approach to prepare red emissive NCs with high QY and high reproducibility.

  20. Produção de celulase por fermentação submersa empregando resíduos agroindustriais para a produção de etanol

    OpenAIRE

    Rocha, Nattácia Rodrigues de Araújo Felipe

    2011-01-01

    Neste trabalho estudou-se a produção de um complexo enzimático gerado a partir de resíduos agroindustriais e Aspergillus niger e na sequência a produção de bioetanol utilizando o mesmo resíduo. Nos testes preliminares estudou-se o melhor substrato e escolheu-se a melhor cepa de micro-organismo capaz de gerar um complexo enzimático com boa atividade em termos de celulase (FPase). O complexo enzimático gerado foi submetido a um processo de precipitação salina com o intuito de concentrar o caldo...

  1. Liquidus Projection and Isothermal Section of the Sb-Se-Sn System

    Science.gov (United States)

    Chang, Jui-shen; Chen, Sinn-wen

    2017-12-01

    Sb-Se-Sn ternary alloys are promising chalcogenide materials. The liquidus projection and 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system are determined. Numerous Sb-Se-Sn alloys are prepared, and their primary solidification phases are examined. In addition to the three terminal phases, (Sb), (Se) and (Sn), there are Sb2Sn3, SbSn, SnSe, SnSe2, Sb2Se3, Sn2Sb9Se9, and SnSb2Se4 phases. In addition, there are two miscibility gaps along the Sb-Se and Se-Sn and sides. There are ten invariant reactions in the Sb-Se-Sn ternary system, and seven of them are experimentally determined in this study. The lowest reaction temperature of determined invariant reaction is L + SbSn = (Sn) + SnSe at 515.4 K ± 5 K (242.2 °C ± 5 °C). There are nine tie-triangles, which are Liquid + SbSn + SnSe, SbSn + SnSe + (Sb), SnSe + (Sb) + Sn2Sb9Se9, (Sb) + Sb2Se3 + Sn2Sb9Se9, SnSe + Sn2Sb9Se9 + SnSb2Se4, Sb2Se3 + Sn2Sb9Se9 + SnSb2Se4, SnSe + SnSe2 + SnSb2Se4, SnSe2 + SnSb2Se4 + Sb2Se3, and SnSe2 + Sb2Se3 + Liquid in the 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system.

  2. Synthesis, crystal structure, optical, and electronic study of the new ternary thorium selenide Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); Mesbah, Adel [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); ICSM, UMR 5257 CEA/CNRS/UM2/ENSCM, Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Beard, Jessica [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); Lebègue, Sébastien [Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2, UMR CNRS 7036), Institut Jean Barriol, Université de Lorraine, BP 239, Boulevard des Aiguillettes, 54506 Vandoeuvre-lès-Nancy (France); Malliakas, Christos D. [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); Ibers, James A., E-mail: ibers@chem.northwestern.edu [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States)

    2015-11-15

    The compound Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} has been synthesized by solid-state methods at 1173 K. Its crystal structure features one-dimensional chains of {sup 1}{sub ∞}[Th(Se){sub 3}(Se{sub 2}){sub 2}{sup 6−}] separated by Ba{sup 2+} cations. Each Th atom in these chains is coordinated to two Se–Se single-bonded pairs and four Se atoms to give rise to a pseudooctahedral geometry around Th. The Th–Se distances are consistent with Th{sup 4+} and hence charge balance of Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} is achieved as 3×Ba{sup 2+}, 1×Th{sup 4+}, 3×Se{sup 2−}, and 2×Se{sub 2}{sup 2−}. From optical measurements the band gap of Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} is 1.96(2) eV. DFT calculations indicate that the compound is a semiconductor. - Graphical abstract: Local coordination environment of Th atoms in the Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} structure. - Highlights: • Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} has been synthesized by solid-state methods at 1173 K. • The structure features chains of {sup 1}{sub ∞}[Th(Se){sub 3}(Se{sub 2}){sub 2}{sup 6−}] separated by Ba{sup 2+} cations. • Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} is a semiconductor with a band gap of 1.96(2) eV.

  3. Por uma cidade que se move e se comunica: corpo, rua e improviso

    Directory of Open Access Journals (Sweden)

    Julia Saldanha Vieira de Aguiar

    2009-06-01

    Full Text Available Este trabalho trata da relação de um lugar com suas pessoas. A reflexão acontece a partir de um estudo de caso: o Camelódromo da Praça XV. O Camelódromo foi uma grande feira, que durante 40 anos ocupou um espaço importante no centro de Porto Alegre/RS. (Auto organizado e vivido principalmente pelo povo, o fenômeno se configurava em um lugar onde improviso e estética constituiam o modo de ser e agir no cotidiano da rua. Ironicamente, no início de 2009, o Camelódromo foi transferido para dentro de um prédio. Hoje, onde se desenrolava o espetáculo do imprevisível, encontra-se um estacionamento para carros. Este trabalho foi produzido nos últimos meses do Camelódromo; em um espírito de elogio à estética do improviso e à auto-organização. Buscamos articular idéias da teoria da complexidade, do urbanismo, das artes e da comunicação, para tentar compreender um pouco essa manifestação espontânea, tão característica da urbe no século XXI.

  4. Synthesis of CdSe Quantum Dots Using Fusarium oxysporum

    Directory of Open Access Journals (Sweden)

    Takaaki Yamaguchi

    2016-10-01

    Full Text Available CdSe quantum dots are often used in industry as fluorescent materials. In this study, CdSe quantum dots were synthesized using Fusarium oxysporum. The cadmium and selenium concentration, pH, and temperature for the culture of F. oxysporum (Fusarium oxysporum were optimized for the synthesis, and the CdSe quantum dots obtained from the mycelial cells of F. oxysporum were observed by transmission electron microscopy. Ultra-thin sections of F. oxysporum showed that the CdSe quantum dots were precipitated in the intracellular space, indicating that cadmium and selenium ions were incorporated into the cell and that the quantum dots were synthesized with intracellular metabolites. To reveal differences in F. oxysporum metabolism, cell extracts of F. oxysporum, before and after CdSe synthesis, were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. The results suggested that the amount of superoxide dismutase (SOD decreased after CdSe synthesis. Fluorescence microscopy revealed that cytoplasmic superoxide increased significantly after CdSe synthesis. The accumulation of superoxide may increase the expression of various metabolites that play a role in reducing Se4+ to Se2− and inhibit the aggregation of CdSe to make nanoparticles.

  5. Mechanical and magneto-electronic properties of half-metallic ferromagnetism in Ti-doped ZnSe and CdSe alloys: Ab initio study

    Science.gov (United States)

    El Amine Monir, Mohammed; Ullah, Hayat; Baltach, Hadj; Gulbahar Ashiq, M.; Khenata, R.

    2017-11-01

    In this article we have studied the structural, elastic, electronic and magnetic properties of Zn1-xTixSe and Cd1-xTixSe alloys at (x = 0.25, 0.50, 0.75) using first principles density functional theory calculations with local spin density approximation (LSDA) and generalized gradient approximation plus Hubbard parameter (GGA+U) as exchange-correlation potential. The physical properties of both alloys were investigated in the zinc-blend phase. The structural parameters at equilibrium are consistent with experimental and earlier theoretical predictions. The elastic constants are also computed and compared with the literature. The DOS curves of Zn1-xTixSe and Cd1-xTixSe alloys for all the concentrations show the existence of hybridization among Ti (3d) and Se (4p) states. The calculated exchange constants N0α(s-d) and N0β (p-d) are useful to determine the contribution in the valence band and conduction band and are also shows the magnetic character of these alloys. In addition, the p-d hybridization in the PDOS reduces local magnetic moment of Ti from its free space charge of 2 μB and results small magnetic moments on the nonmagnetic Zn, Cd and Se sites. The calculated negative values of formation energy (Ef) reveal that all the Zn1-xTixSe and Cd1-xTixSe alloys are thermodynamically stables. A larger/Smaller value of Curie temperature (TC) for all the Zn1-xTixSe and Cd1-xTixSe alloys shows the strong/low interaction among the magnetic atoms respectively.

  6. Microbial Precipitation of Cr(III)-Hydroxide and Se(0) Nanoparticles During Anoxic Bioreduction of Cr(VI)- and Se(VI)-Contaminated Water.

    Science.gov (United States)

    Kim, Yumi; Oh, Jong-Min; Roh, Yul

    2017-04-01

    This study examined the microbial precipitations of Cr(III)-hydroxide and Se(0) nanoparticles during anoxic bioreductions of Cr(VI) and Se(VI) using metal-reducing bacteria enriched from groundwater. Metal-reducing bacteria enriched from groundwater at the Korea Atomic Energy Research Institute (KAERI) Underground Research Tunnel (KURT), Daejeon, S. Korea were used. Metal reduction and precipitation experiments with the metal-reducing bacteria were conducted using Cr(VI)- and Se(VI)-contaminated water and glucose as a carbon source under an anaerobic environment at room temperature. XRD, SEM-EDX, and TEM-EDX analyses were used to characterize the mineralogy, crystal structure, chemistry, shape, and size distribution of the precipitates. The metal-reducing bacteria reduced Cr(VI) of potassium chromate (K₂CrO₄) to Cr(III) of chromium hydroxide [Cr(OH)3], and Se(VI) of sodium selenate (Na₂SeO₄) to selenium Se(0), with changes of color and turbidity. XRD, SEM-EDX, and TEM-EDX analyses revealed that the chromium hydroxide [Cr(OH)₃] was formed extracellularly with nanoparticles of 20–30 nm in size, and elemental selenium Se(0) nanoparticles had a sphere shape of 50–250 nm in size. These results show that metal-reducing bacteria in groundwater can aid or accelerate precipitation of heavy metals such as Cr(VI) and Se(VI) via bioreduction processes under anoxic environments. These results may also be useful for the recovery of Cr and Se nanoparticles in natural environments.

  7. Ud at se med Erasmus

    DEFF Research Database (Denmark)

    Frandsen, Pernille

    2009-01-01

    Få lidt luft under vingerne, kom ud at møde udenlandske kolleger og se, hvordan man også kan lave uddannelsesbibliotek. Med begejstring fortæller tre bibliotekarer om deres oplevelser i det store udland – alt sammen finansieret af Erasmus.......Få lidt luft under vingerne, kom ud at møde udenlandske kolleger og se, hvordan man også kan lave uddannelsesbibliotek. Med begejstring fortæller tre bibliotekarer om deres oplevelser i det store udland – alt sammen finansieret af Erasmus....

  8. Effects of hydrostatic pressure on the thermoelectric properties of the ɛ-polytype of InSe, GaSe, and InGaSe2 semiconductor compounds: an ab initio study

    Science.gov (United States)

    Elsayed, H.; Olguín, D.; Cantarero, A.

    2017-12-01

    This work presents an ab initio study of the effects of hydrostatic pressure on the Seebeck coefficients and thermoelectric power factors of the ɛ-polytype of InSe, GaSe, and InGaSe2 semiconductor compounds. Our study is performed using the semi-classical Boltzmann theory and the rigid band approach. The electronic band structures of these materials are calculated using the full-potential linearized augmented plane-wave method. The obtained thermoelectric properties are discussed in terms of the results of the electronic structure calculations. As we will show, our calculated Seebeck coefficient values indicate that these materials are good alternatives to other well-studied thermoelectric systems.

  9. VerSeDa: vertebrate secretome database.

    Science.gov (United States)

    Cortazar, Ana R; Oguiza, José A; Aransay, Ana M; Lavín, José L

    2017-01-01

    Based on the current tools, de novo secretome (full set of proteins secreted by an organism) prediction is a time consuming bioinformatic task that requires a multifactorial analysis in order to obtain reliable in silico predictions. Hence, to accelerate this process and offer researchers a reliable repository where secretome information can be obtained for vertebrates and model organisms, we have developed VerSeDa (Vertebrate Secretome Database). This freely available database stores information about proteins that are predicted to be secreted through the classical and non-classical mechanisms, for the wide range of vertebrate species deposited at the NCBI, UCSC and ENSEMBL sites. To our knowledge, VerSeDa is the only state-of-the-art database designed to store secretome data from multiple vertebrate genomes, thus, saving an important amount of time spent in the prediction of protein features that can be retrieved from this repository directly. VerSeDa is freely available at http://genomics.cicbiogune.es/VerSeDa/index.php. © The Author(s) 2017. Published by Oxford University Press.

  10. Raman scattering and structural analysis of electrodeposited CuInSe2 and S-rich quaternary CuIn(S,Se)2 semiconductors for solar cells

    International Nuclear Information System (INIS)

    Izquierdo-Roca, Victor; Fontane, Xavier; Morante, Joan Ramon; Saucedo, Edgardo; Ruiz, Carmen M.; Grand, Pierre-Philippe; Jaime-Ferrer, Jesus Salvador; Bermudez, Veronica; Calvo-Barrio, Lorenzo; Alvarez-Garcia, Jacobo; Perez-Rodriguez, Alejandro

    2009-01-01

    This work reports the Raman scattering characterisation of CuInSe 2 precursors grown by single step electrodeposition and the corresponding layers recrystallised under sulphurising conditions for solar cell devices. The analysis of the spectra measured on the as-grown precursors has allowed identifying the main secondary phases in these layers with elemental Se, Cu-Se phases and chalcopyrite Cu-poor ordered vacancy domains. To deepen in the identification of the Cu-Se phases, these measurements have been correlated with the analysis of binary Cu-Se layers. The experimental data indicate that formation of both Se and Cu-Se phases is likely controlled by the Se content in the layers. For values of stoichiometry below 1.15, excess Cu in the layers is accommodated in a phase with very low Raman efficiency (as Cu 2 Se). Increasing the content of Se leads to an increase in the spectral contribution from both Se and Cu 2-x Se, being the formation of these phases likely favoured under high excess Se conditions. The characterisation of the corresponding recrystallised layers has allowed analysing the impact of the presence of the secondary phases in the as-grown absorbers on the performance of the final solar cells. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Determination of the optimal conditions for simultaneous production of 73SE and 75SE radioisotopes in a 30 MeV cyclotron

    International Nuclear Information System (INIS)

    Pejman Rowshanfazad; Amirreza Jalilian; Mahsheed Sabet

    2004-01-01

    Purpose: 73 Se and 75 Se radioisotopes are widely used in medicine, industry and agriculture. 75 Se is used in high activity brachytherapy (1), assessment of pancreatic exocrine function (2, 3), study of bile acids and evaluation of illeal function (4, 5, 6), industrial radiography (7, 8) and as a tracer in the assessment of chemical, biochemical, biophysical processes, metabolic research and agricultural studies. 73 Se is used in pancreas scanning (9), hyperthyroidism diagnosis(10), adrenal scanning (11), tumor detection (12, 13, 14), detection of brain dopamine receptors (15), parathyroid tumor detection (10) and detection of brain blood flow (16). These radioisotopes were selected to be produced in the country according to their wide range of applications. The idea of simultaneous production of 73 Se and 75 Se arouse after the completion of primary studies. Important physical characteristics of these radioisotopes are shown in table l. Methods: 1 Selection of the Best Reaction. Various nuclear reactions which may be used for the production of 73 Se and 75 Se are shown in table 2 (17, 18, 19). Among the above reactions, those which use α and 3 He as the projectile particles were discarded since high energy and high intensity beams of α and 3 He are not available in the country at present. Those reactions which used 74 Se and 76 Se as the target material could not be used, since these isotopes have low isotopic values (0.87% and 9.02% respectively), and their chemical separation processes are difficult, expensive and time-taking, due to the equal chemical properties of the product and the target material (20). Thus 75 As(p, n) 75 Se seemed to be the most appropriate reaction for the production of 75 Se. The 75 As(d, 4n) 73 Se reaction is not as suitable as 75 As(p, 3n) 73 Se, because of the lower radionuclidic purity of the product (18). Thus the best reaction for the production of 73 Se was determined to be 75 As(p, 3n) 73 Se. There was no need for an isotopic

  12. Seed-mediated direct growth of CdSe nanoclusters on substrates

    International Nuclear Information System (INIS)

    Pan Shangke; Ebrahim, Shaker; Soliman, Moataz; Qiao Qiquan

    2013-01-01

    Different shapes of CdSe nanostructures were obtained by hydrothermal method with varied Se sources and buffer layers. Hexagonal nanoparticles of CdSe with Wurtzite structure were synthesized from Se powder resource, while CdSe nanoclusters with Wurtzite structure were grown from Na 2 SeO 3 aqueous solution resources at 165 °C using cetyltrimethylammonium bromide as surfactant. Using ZnO nanoparticles as a seed layer, CdSe nanostructures only partially covered the indium tin oxide (ITO) substrates. With ZnO/CdSe quantum dots composite seed layer, CdSe nanostructures fully covered the ITO substrates.

  13. Exotic topological insulator states and topological phase transitions in Sb2Se3-Bi2Se3 heterostructures

    KAUST Repository

    Zhang, Qianfan; Zhang, Zhiyong; Zhu, Zhiyong; Schwingenschlö gl, Udo; Cui, Yi

    2012-01-01

    in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb 2Se 3-Bi 2Se 3 heterostructures by first-principle simulation and discovered

  14. Hidrocarbonetos policíclicos aromáticos em resíduos sólidos industriais: uma avaliação preliminar do risco potencial de contaminação ambiental e humana em áreas de disposição de resíduos Polycyclic aromatic hydrocarbons in industrial solid waste: a preliminary evaluation of the potential risk of environmental and human contamination in waste disposal areas

    Directory of Open Access Journals (Sweden)

    Cristina L. S. Sisinno

    2003-04-01

    Full Text Available A disposição adequada dos resíduos sólidos é importante para evitar que os mesmos se transformem em fonte de contaminação ambiental e humana. A NBR 10.004 - Classificação de Resíduos - lista vários hidrocarbonetos policíclicos aromáticos (HPAs e indica que, a presença de pelo menos um deles na massa bruta do resíduo é suficiente para classificá-lo como resíduo perigoso. O objetivo deste estudo foi verificar a presença de HPAs em amostras de resíduos sólidos provenientes de alguns segmentos industriais, para se obter uma avaliação preliminar do potencial de contaminação que estes resíduos podem representar, caso não recebam destino adequado. Pelo menos um dos HPAs previstos na NBR 10.004 (benzo[a]antraceno, benzo[a]pireno, benzo[b]fluoranteno, benzo[k]fluoranteno, indeno[1,2,3-c,d]pireno, criseno ou fluoranteno foi identificado em todos os resíduos estudados, classificando-os como perigosos. Nossos resultados indicam que todos os resíduos estudados continham HPAs de importância toxicológica, o que implica que sua disposição final seja feita em locais adequados para minimizar os riscos à saúde humana e ambiental oriundos das áreas de disposição de resíduos.Proper solid waste disposal is important to avoid human and environmental contamination. The NBR 10,004 Waste Classification lists several polycyclic aromatic hydrocarbons (PAHs and indicates that the presence of at least one PAH in a waste sample is enough to classify it as hazardous. The aim of this study was a preliminary evaluation of PAHs in solid waste samples from selected industries to obtain a preliminary overview of their potential for contamination in case of improper disposal. One or more PAHs listed in NBR 10,004 (benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, indene[1,2,3-c,d]pyrene, chrysene, or fluoranthene were found in all samples, thus leading to their classification as hazardous waste. Our results showed

  15. Software de simulações dos modelos Sir e Seir como ferramenta de gerenciamento ambiental de doenças epidemiológicas

    Directory of Open Access Journals (Sweden)

    Ranaya Silva Barbosa

    2016-10-01

    Full Text Available As epidemias têm causado pânico em todo o mundo desde a antiguidade, nos dias de hoje a dengue, zika vírus e a chikungunya tem sido alvo de grande preocupação nacional. Observa-se, portanto, a importância de se compreender a dinâmica de transmissão dessas doenças através da técnica de investigação por modelos matemáticos, uma vez que este método não interfere no meio estudado. Visando auxiliar no gerenciamento ambiental por meio da compreensão da dinâmica das epidemias, captura do comportamento qualitativo do modelo e dos parâmetros que podem influenciar significativamente no processo de transmissão, foi desenvolvido um software de simulação dos modelos SIR e SEIR empregando o Método de Integração Numérica de Runge-Kutta de 4ª ordem implementado em linguagem de programação JAVA.

  16. Paracoctidioidomicose: atendimento a nível de assistência primária a saúde The treatment of paracoccidioidomycosis at primary health level

    Directory of Open Access Journals (Sweden)

    Sérgio Pripas

    1988-06-01

    Full Text Available Discute-se o tratamento de pacientes com paracoccidioidomicose a nível de assistência primária a saúde. Foram tratados 8 pacientes no Centro de Saúde I, de São Carlos, SP (Brasil, empregando-se o cetoconazol, durante um ano, na dose de 400 mg diários, em uma única tomada. Em todos os pacientes tratados, houve remissão do quadro clínico e melhora dos exames laboratoriais. Não houve relato de efeitos colaterais. Conclui com proposta de tratamento da paracoccidioidomicose, a nível de rede básica de saúde.The treatment of paracoccidioidomycosis, with ketoconazole, at public health level is discussed. Eight patients were treated with single daily doses of 400 mg of ketoconazole for one year. The patients were treated at Health Center I in S. Carlos, Brazil. All patients treated showed clinical remission and an improvement in radiological findings. No side-effects were reported. The benefits of this treatment at Health Centers, under the administrative, social and economic aspects are stressed.

  17. Fagotipagem de cepas de Staphylococcus aureus resistentes a antibióticos, isoladas de leite

    Directory of Open Access Journals (Sweden)

    Wanderley Pereira de Araújo

    1998-01-01

    Full Text Available A partir de amostras de leite cru foram isoladas 201 cepas de S. aureus, as quais foram submetidas a provas de resistência a antibióticos pelo método dos discos impregnados com os seguintes antibacterianos: amicacina, ampicilina, cefalotina, cefoxitina, cloranfenicol, clindamicina, oxacilina, penicilina, tetraciclina, tobramicina e vancomicina. Com exceção de 88 (43,8%, 90 (44,8%, 24 (11,9% e 40 (19,9% cepas resistentes à penicilina, ampicilina, cloranfenicol e tetraciclina, respectivamente, a maioria das 201 cepas (95% ou mais foi sensível aos antibióticos utilizados. As cepas resistentes a estes quatro antibióticos foram fagotipadas, empregando-se os Conjuntos Básicos Internacionais de bacteriófagos para cepas de origem humana e bovina, verificando-se que houve predomínio de cepas sensíveis a fagos dos grupos III e III/NC do conjunto básico humano e a fagos dos grupos III, IV e da associação III/IV do conjunto bovino.

  18. Avaliação química de fertilizantes com micronutrientes tipo fritas

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    F. Vale

    2003-02-01

    Full Text Available O objetivo deste trabalho foi analisar fertilizantes tipo fritas comercializados no Brasil, utilizando o método prescrito para análise de fertilizantes minerais não-fritas, o que normalmente tem sido feito na rotina pelos laboratórios de análises de fertilizantes. Também foram analisados os teores de Cd, Ni e Pb nesses fertilizantes. Observou-se que o método utilizado foi adequado para a análise dos fertilizantes tipo fritas, o que indica que as fritas comercializadas no Brasil não são realmente fritas, isto é, silicatos fundidos com micronutrientes. A presença de micronutrientes metálicos nos produtos sem as respectivas garantias e a alta concentração de metais indesejáveis, principalmente Pb, são fortes indícios de utilização de resíduos industriais na fabricação desses fertilizantes. Sugere-se que sejam estudados e propostos extratores químicos para avaliar a eficiência agrícola desses produtos.

  19. A práxis de Lebret: economia humana, desenvolvimentismo católico e a industrialização do Nordeste

    Directory of Open Access Journals (Sweden)

    José Henrique Artigas de Godoy

    Full Text Available Resumo O estudo do pensamento do padre dominicano francês Louis-Joseph Lebret procura refletir sobre as estratégias desenvolvimentistas formuladas nas décadas de 1950 e 1960 no Brasil. Destaca-se uma linhagem de pensamento católica, pouco estudada na história do pensamento desenvolvimentista no país. O foco na trajetória e na práxis de Lebret, envolvendo a recepção de seu pensamento junto à esquerda católica e às primeiras gerações de urbanistas no Brasil, atenta para a relevância histórica e para a atualidade do pensamento do clérigo. Neste sentido, ressalta-se o relatório sobre a industrialização de Pernambuco, primeiro esforço de planejamento de políticas de desenvolvimento regional e marco inaugural do Complexo Industrial e Portuário de Suape, um dos maiores polos de investimentos industriais da história da região.

  20. BRAND EQUITY DA USIMINAS: UM ESTUDO NO SETOR SIDERÚRGICO BRASILEIRO DE AÇOS PLANOS

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    Daniel Hofer Bastos

    2015-02-01

    Full Text Available O objetivo deste trabalho foi medir o valor agregado (“Brand Equity” da marca USIMINAS® na percepção de compradores de aços planos no mercado brasileiro. Para tanto, foi testado o modelo desenvolvido por Juntunen, Juntunen e Juga (2011 relacionado a empresas industriais do setor de logística. Além disso, foi avaliado se a inserção do construto Confiança (BALLESTER, 2004  no modelo teórico original aumenta a variância explicada do Brand Equity. Foi feita pesquisa descritiva em que foi aplicado questionário de pesquisas anteriores com pequenas alterações ao setor de negócios contextual. Os resultados indicam que a inserção do construto Confiança aumenta a variância explicada do Brand Equity em relação ao modelo original de Juntunen, Juntunen e Juga (2011. Além disso, foram observados alguns resultados divergentes no que se refere à relação positiva entre Imagem e Brand Equity, e entre Imagem e Fidelidade.

  1. The synthesis and photocatalytic activity of ZnSe microspheres

    International Nuclear Information System (INIS)

    Cao Huaqiang; Xiao Yujiang; Zhang Sichun

    2011-01-01

    This paper reports the synthesis of semiconductor ZnSe microspheres composed of nanoparticles via a solvothermal route between the organic molecule selenophene (C 4 H 4 Se) and ZnCl 2 without adding any surfactant. The ZnSe microspheres were characterized by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), specific surface area measurement, and photoluminescence (PL) spectra. A strong and broad blue PL emission at 443 nm in wavelength (∼2.79 eV in photon energy) is attributed to the near-band-edge (NBE) emission of ZnSe, while the 530 nm peak is a defect-related (DL) emission. The photocatalytic activity of the as-prepared ZnSe microspheres was evaluated by photodegradation of methyl orange (MO) dye under ultraviolet (UV) light and visible light irradiation. The degradations of MO reach 94% or 95.1%, close to 100%, in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 7 or 10 h under UV irradiation, respectively. Meanwhile the degradations of MO reach 94.3% or 60.6% in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 12 h, respectively. The degradation rate of ZnSe microspheres is twice that of ZnSe commercial powder under UV light irradiation, and three times under visible light irradiation. The degradation process of MO dye on ZnSe microspheres under UV or visible light is also discussed.

  2. ¿Y, cómo se hacen?

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    Juan Ruiz

    2015-01-01

    Full Text Available El mundo de los dibujos animados es producto de la imaginación, de la fantasía que vuela en los sueños de los hombres de cualquier edad. El artículo relata la forma en cómo estos simpáticos personajes, que vemos a diario en el cine o la televisión, pueden moverse tan libremente y con tanto desenfado. Se parte de la idea o argumento, el guionista narra la historia de lo que será el animado. Luego el director con un dibujante trazan las escenas principales de la historia (storyboard o guión dibujado se discute con los artistas y realizadores del filme; una vez aprobado este se perfila el diseño de los personajes, se realiza la escenografía (maquetas de ser necesario. Se hacen los parlamentos o diálogos de los personajes para que actores(as pongan las voces y sigue el proceso más fino y técnico.

  3. The influence of CdSe and ZnSe nanoparticles on the optical properties of Sm"3"+ ions in lead borate glasses

    International Nuclear Information System (INIS)

    Mallur, Saisudha B.; Heidorn, William D.; Fatokun, Stephen O.; Joshi, Krishna D.; Bista, Sandip S.; Babu, Panakkattu K.

    2017-01-01

    The effect of glass composition and the presence of CdSe/ZnSe nanoparticles (NPs) on the optical absorption and fluorescence of Sm-doped lead borate glasses are studied. Three sets of glass samples xPbO:(99.5-x) B_2O_3:0.5Sm_2O_3, x = 29.5–69.5 mol%, xPbO:(96.5-x) B_2O_3:0.5Sm_2O_3: 3CdSe/ZnSe, x = 36.5, and 56.5 mol% are prepared. NPs are grown by annealing these glasses just below the glass transition temperature. Average size of both types of NPs increases with annealing time; however, CdSe NPs grew to a larger size range (2 to 20 nm) compared to ZnSe NPs (1 to 16 nm). We analyzed the hypersensitive transition, intensity parameters, radiative transition probability, stimulated emission cross section (σ_p), and the area ratio of the electric dipole/magnetic dipole transitions of Sm"3"+. The intensity parameters show a minimum at 11 h annealing for 36.5 mol% and a maximum for the same annealing duration in 56.5 mol% PbO containing CdSe NPs. The σ_p for 56.5 mol% of PbO with CdSe NPs is found to be a maximum when the average NP size is around 14 nm. ZnSe NPs containing glasses also show significant changes in σ_p when the average particle size is ~16 nm, for 36.5 mol% PbO. Our results suggest that the optical properties of Sm"3"+ in lead borate glasses are sensitive to its electronic environment which can be modified by varying the base glass composition and/or incorporating large NPs of CdSe/ZnSe. The large σ_p values that we observe for some of the glass compositions make them attractive materials for photonic devices and photovoltaic applications.

  4. Variation of Se, Zn, Co, Fe and Rb distribution in rats upon sequence of injection with SeO2 and glutathione

    International Nuclear Information System (INIS)

    Czauderna, M.; Samochocka, K.; Kwiathkowska, J.

    1984-01-01

    The contents of Se, Zn, Co, Fe and Rb in several organs of Wistar rats were determined by instrumental neutron activation analysis (INAA) after injections of SeO 2 and glutathione (GSH). Se was incorporated in all the examined organs, and the efficiency of incorporation does not depend upon the sequence of injection with SeO 2 and GSH. The sequence of these injections affects the contents of the other elements in all the examined organs. (author)

  5. Instantaneous preparation of CuInSe2 films from elemental In, Cu, Se particles precursor films in a non-vacuum process

    International Nuclear Information System (INIS)

    Kaigawa, R.; Uesugi, T.; Yoshida, T.; Merdes, S.; Klenk, R.

    2009-01-01

    CuInSe 2 (CIS) films are successfully prepared by means of non-vacuum, instantaneous, direct synthesis from elemental In, Cu, Se particles precursor films without prior synthesis of CIS nanoparticle precursors and without selenization with H 2 Se or Se vapor. Our precursor films were prepared on metal substrates by spraying the solvent with added elemental In, Cu, and Se particles. Precursor films were instantaneously sintered using a spot welding machine. When the electric power was fixed to 0.6 kVA, elemental In, Cu, or Se peaks were not observed and only peaks of CIS are observed by X-ray diffraction (XRD) on the film sintered for 7/8 s. We can observe XRD peaks indicative of the chalcopyrite-type structure, such as (101), (103) and (211) diffraction peaks. We conclude that the synthesized CIS crystals have chalcopyrite-type structure with high crystallinity

  6. Constraining the cross section of 82Se(n, γ)83Se to validate the β-Oslo method

    Science.gov (United States)

    Childers, K.; Liddick, S. N.; Crider, B. P.; Dombos, A. C.; Lewis, R.; Spyrou, A.; Couture, A.; Mosby, S.; Prokop, C. J.; Naqvi, F.; Larsen, A. C.; Guttormsen, M.; Campo, L. C.; Renstrom, T.; Siem, S.; Bleuel, D. L.; Perdikakis, G.; Quinn, S.

    2017-09-01

    Neutron capture cross sections of short-lived nuclei are important for a variety of basic and applied nuclear science problems. However, because of the short half-lives of the nuclei involved and the nonexistence of a neutron target, indirect measurement methods are required. One such method is the β-Oslo method. The nuclear level density and γ strength function of a nucleus are extracted after β-decay and used in a statistical reaction model to constrain the neutron capture cross section. This method has been used previously, but must be validated against a directly measured neutron capture cross section. The neutron capture cross section of 82Se has been measured previously, and 83Se can be accessed by the β-decay of 83As. The β-decay of 83As to 83Se was studied using the SuN detector at the NSCL and the β-Oslo method was utilized to constrain the neutron capture cross section of 82Se, which is compared to the directly measured value.

  7. Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors

    Science.gov (United States)

    Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

    2018-02-01

    In this work, bismuth selenides (Bi2Se3 and Bi3Se4), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi2Se3 nanoplates exhibit much better performance as an electrode material than Bi3Se4 nanoparticles do, delivering a higher specific capacitance (272.9 F g-1) than that of Bi3Se4 (193.6 F g-1) at 5 mV s-1. This result may be attributed to the fact that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi3Se4). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi2Se3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm-3 at 20 mV s-1 (Bi3Se4: 79.1 F cm-3), a high energy density of 17.9 mWh cm-3 and a high power density of 18.9 W cm-3. The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi2Se3 (Bi3Se4:90.3%). Clearly, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

  8. Production of Se-methylselenocysteine in transgenic plants expressing selenocysteine methyltransferase

    Directory of Open Access Journals (Sweden)

    Harris Hugh

    2004-01-01

    Full Text Available Abstract Background It has become increasingly evident that dietary Se plays a significant role in reducing the incidence of lung, colorectal and prostate cancer in humans. Different forms of Se vary in their chemopreventative efficacy, with Se-methylselenocysteine being one of the most potent. Interestingly, the Se accumulating plant Astragalus bisulcatus (Two-grooved poison vetch contains up to 0.6% of its shoot dry weight as Se-methylselenocysteine. The ability of this Se accumulator to biosynthesize Se-methylselenocysteine provides a critical metabolic shunt that prevents selenocysteine and selenomethionine from entering the protein biosynthetic machinery. Such a metabolic shunt has been proposed to be vital for Se tolerance in A. bisulcatus. Utilization of this mechanism in other plants may provide a possible avenue for the genetic engineering of Se tolerance in plants ideally suited for the phytoremediation of Se contaminated land. Here, we describe the overexpression of a selenocysteine methyltransferase from A. bisulcatus to engineer Se-methylselenocysteine metabolism in the Se non-accumulator Arabidopsis thaliana (Thale cress. Results By over producing the A. bisulcatus enzyme selenocysteine methyltransferase in A. thaliana, we have introduced a novel biosynthetic ability that allows the non-accumulator to accumulate Se-methylselenocysteine and γ-glutamylmethylselenocysteine in shoots. The biosynthesis of Se-methylselenocysteine in A. thaliana also confers significantly increased selenite tolerance and foliar Se accumulation. Conclusion These results demonstrate the feasibility of developing transgenic plant-based production of Se-methylselenocysteine, as well as bioengineering selenite resistance in plants. Selenite resistance is the first step in engineering plants that are resistant to selenate, the predominant form of Se in the environment.

  9. Optical band gap study of a-Se and Se-Sb thin films

    International Nuclear Information System (INIS)

    Kaur, Ramandeep; Singh, Palwinder; Thakur, Anup

    2016-01-01

    Amorphous selenium (a-Se) and a-Se_9_5Sb_5 alloy were prepared using melt quenching technique. X-ray diffraction (XRD) pattern confirmed the amorphous nature of the prepared samples. Composition of the prepared samples has been determined using Energy dispersive X-ray fluorescence (EDXRF) technique. Differential thermal analysis (DTA) confirmed the glassy nature of the prepared samples. Thin films of the prepared samples were deposited on glass substrate using thermal evaporation method. Amorphous nature of the deposited films was confirmed using XRD. Optical properties of these films were obtained from the UV-VIS transmission spectra, at normal incidence, over 200-1100 nm spectral range. The optical absorption edge was described by using the model given by the Tauc. Optical band gap of the deposited films was calculated using Tauc plot. Optical characterization showed that average transmission and optical band gap decreased with the addition of antinomy.

  10. Green synthesis of ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) using a new, rapid and room temperature photochemical approach

    International Nuclear Information System (INIS)

    Molaei, M.; Bahador, A.R.; Karimipour, M.

    2015-01-01

    In this work, ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) were synthesized using a one-pot, rapid and room temperature photochemical method. UV illumination provided the required energy for the chemical reactions. Synthesized NCs were characterized using X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), UV–vis and photoluminescence (PL) spectroscopy. XRD pattern indicated cubic zinc blende structure for ZnSe NCs and the TEM image indicated round-shaped particles, most of which had a diameter of about 3 nm. Band gap of ZnSe NCs was obtained as about 3.6 eV, which was decreased by increasing the illumination time. Synthesized NCs indicated intensive and narrow emission in the UV-blue area (370 nm) related to the excitonic recombination and a broad band emission with a peak located at about 490 nm originated from the DAP (donor–acceptor pairs) recombination. ZnS shell was grown on ZnSe cores using a reaction based on the photo-sensitivity of Na 2 S 2 O 3 . For ZnSe@ZnS core–shell NCs, XRD diffraction peaks shifted to higher angles. TEM image indicated a shell around cores and most of the ZnSe@ZnS NCs have a diameter of about 5 nm. After the ZnS growth, ZnSe excitonic emission shifted to the longer wavelength and PL intensity was increased considerably. PL QY was obtained about 11% and 17% for ZnSe and ZnSe@ZnS core–shell QDs respectively. - Highlights: • A green photochemical approach was reported for synthesis of ZnSe NCs. • ZnS shell was grown around ZnSe using a new method. • Synthesis method was rapid, simple and at room temperature. • ZnSe NCs indicated a narrow UV-blue and a broad DAP emissions. • PL intensity was increased considerably by ZnS shell growth

  11. de drogas que se consumen en su medio

    Directory of Open Access Journals (Sweden)

    José F. Enríquez Bielma

    2006-01-01

    Full Text Available Las adicciones son un problema de salud pública. Se estima que en México 3.5 millones de personas entre 12 a los 65 años han consumido algún tipo de drogas. A pesar de los avances en los estudios, se ha dejado de lado el carácter cultural que tiene la adicción. Con este estudio, se deseba conocer qué saben los estudiantes de segundo de secundaria sobre cuáles son las drogas que se consumen en su medio. Se llevó a cabo un estudio observacional con un muestreo aleatorio, con múltiples etapas y proporcional al tamaño en escuelas públicas y privadas. En total se estudiaron 42 escuelas del municipio de León, Gto., México de las cuales el 76.2% lo conformaron las escuelas públicas y el resto las escuelas privadas. Refirieron que conocen que se consumen, en su medio, 11 tipos de drogas. El 88% mencionó a la cocaína en primer lugar, en segundo lugar con un 85% la marihuana, siguiendo las tachas en un 62% y el pegamento en un 49%. En cuanto a los nombres que los estudiantes le dan a las drogas, estos van desde 23 hasta los 4 nombres, siendo la marihuana a la que se le da el mayor número de nombres, seguidos de la cocaína y el éxtasis.

  12. Future strategy of SE

    International Nuclear Information System (INIS)

    Arcelli, M.

    2006-01-01

    In this presentation author (General Director of Slovenske elektrarne, a. s.) presents structure and investment plans of SE. The feasibility study of construction of the blocks 3 and 4 of the Mochovce NPP is presented

  13. Magnetic excitation and local magnetic susceptibility of the excitonic insulator Ta2NiSe5 investigated by 77Se NMR

    Science.gov (United States)

    Li, Shang; Kawai, Shunsuke; Kobayashi, Yoshiaki; Itoh, Masayuki

    2018-04-01

    77Se NMR measurements were made on polycrystalline and single-crystalline samples to elucidate local magnetic susceptibility and magnetic excitation of Ta2NiSe5 , which is proposed to undergo an exciton condensation accompanied by a structural transition at Tc=328 K . We determine the 77Se Knight shift tensors for the three Se sites and analyze their anisotropy based on the site symmetry. The temperature dependence of the Knight shift is discussed on the basis of spin and orbital susceptibilities calculated for two-chain and two-dimensional three-band models. The large fraction of the Se 4 p orbital polarization due to the mixing between Ni 3 d and Se 4 p orbitals is estimated from the analysis of the transferred hyperfine coupling constant. Also the nuclear spin-lattice relaxation rate 1 /T1 is found not to show a coherent peak just below Tc and to obey the thermally activated temperature dependence with a spin gap energy of 1770 ±40 K . This behavior of 1 /T1 monitors the exciton condensation as proposed by the theoretical study of 1 /T1 based on the three-chain Hubbard model for the excitonic insulator.

  14. Thermoelectric and mechanical properties of spark plasma sintered Cu3SbSe3 and Cu3SbSe4: Promising thermoelectric materials

    Science.gov (United States)

    Tyagi, Kriti; Gahtori, Bhasker; Bathula, Sivaiah; Toutam, Vijaykumar; Sharma, Sakshi; Singh, Niraj Kumar; Dhar, Ajay

    2014-12-01

    We report the synthesis of thermoelectric compounds, Cu3SbSe3 and Cu3SbSe4, employing the conventional fusion method followed by spark plasma sintering. Their thermoelectric properties indicated that despite its higher thermal conductivity, Cu3SbSe4 exhibited a much larger value of thermoelectric figure-of-merit as compared to Cu3SbSe3, which is primarily due to its higher electrical conductivity. The thermoelectric compatibility factor of Cu3SbSe4 was found to be ˜1.2 as compared to 0.2 V-1 for Cu3SbSe3 at 550 K. The results of the mechanical properties of these two compounds indicated that their microhardness and fracture toughness values were far superior to the other competing state-of-the-art thermoelectric materials.

  15. Determination of total, and bound Se in sera by INAA

    International Nuclear Information System (INIS)

    Spate, V.L.; Mason, M.M.; Reams, C.L.; Baskett, C.K.; Morris, J.S.; Mills, D.S.

    1994-01-01

    The comparison between the total selenium in serum ('total Se') with that which is apparently bound to high molecular weight (> 12.000 D) species, presumably proteins ('bound Se') was reported. Nine hundred seventy seven (977) serum samples arising out of a population-based epidemiological study were prepared in duplicate for the determination of 'total Se' by pipeting directly into irradiation vials; and separate duplicate aliquots were dialyzed against DI water for the determination of 'bound Se'. All samples were analyzed by neutron activation analysis via 77m Se (17.4s) A small dialyzable Se component (∼ 6%) ('free Se'), defined as the difference between the 'total Se' minus the 'bound Se', was identified. (author) 2 refs.; 3 figs.; 5 tabs

  16. Operação de Rastelli utilizando-se conduto valvulado de pericárdio bovino: experiência inicial Rastelli operation with bovine pericardium valved conduit: early experience

    Directory of Open Access Journals (Sweden)

    Carlos R Moraes

    1988-08-01

    Full Text Available O presente trabalho descreve a experiência inicial com a operação de Rastelli, utilizando-se um conduto valvulado de pericárdio bovino preservado em glutaraldeído. O enxerto consta de um conduto, que serve para reconstruir a via de saída do ventrículo direito e o tronco pulmonar, com uma válvula tricúspide suturada em seu interior sem anel de suporte, permitindo, assim, um mecanismo de fluxo unidirecional. De maio de 1986 a outubro de 1987, 5 crianças foram submetidas à operação de Rastelli empregando-se este tipo de conduto valvulado. Três eram do sexo feminino e 2, do masculino, variando a idade de 1 a 8 anos x 5. Três pacientes tinham transposição das grandes artérias, comunicação interventricular (CIV e estenose subpulmonar. Uma criança era portadora de atresia pulmonar com CIV e de um shunt prévio tipo Waterston e, finalmente, a outra tinha um tronco arterial comum tipo II. Dois doentes faleceram de causas não relacionadas ao tipo de conduto valvulado utilizado. O conduto valvulado de pericárdio bovino preservado em glutaraldeído mostrou excelente flexibilidade, facilitando o manuseio cirúrgico e permitindo perfeita adaptabilidade dentro do saco pericárdico. A ausência de anel de suporte tem a vantagem de eliminar qualquer gradiente e de abolir o turbilhonamento do sangue - causas reconhecidas de calcificação.The present report describes the initial experience with the Rastelli operation utilizing a composite graft of glutaraldehyde preserved bovine pericardium. The graft is made up of a tube which serves to reconstruct the outflow tract of the right ventricle and the pulmonary artery, and an inner tricuspid valve, without a supporting ring, which provides the tube with a one-way flow mechanism. From May, 1986 to October, 1987, five children were submitted to Rastelli operation utilizing this valved tube. Three were female and two male, ranging in age from 1 e to 8 years (mean 5 years. Three had transposition

  17. Structural and optical properties of CdSe nanosheets

    Science.gov (United States)

    Solanki, Rekha Garg; Rajaram, P.; Arora, Aman

    2018-04-01

    Nanosheets of CdSe have been synthesized using a solvothermal route using citric acid as an additive. It is found that the citric acid effectively controls the structural and optical properties of CdSe nanostructures. XRD studies confirm the formation of hexagonal wurtzite phase of CdSe. The FESEM micrographs show that the obtained CdSe nanocrystals are in the form of very thin sheets (nanosheets). Optical absorption studies as well as Photoluminescence spectra show that the optical gap is around 1.76 eV which is close to the reported bulk value of 1.74 eV. The prepared CdSe nanosheets because of large surface area may be useful for catalytic activities in medicine, biotechnology and environmental chemistry and in biomedical imaging for in vitro detection of a breast cancer cells.

  18. Evaluation of urban and industrial wastewater treatment plants using radioactive tracers

    International Nuclear Information System (INIS)

    Brandao, Luis Eduardo Barreira

    2001-07-01

    A methodology for studies and evaluation of sewage treatment plants with radioactive tracers is presented.. Radioisotopes as 82 Br ( for the liquid phase), 110m Ag and 140 La, (for the solid phase) was used to evaluate sewage flow rates, mixing pattern in equalization tank and test effluent treatment units. The tracer was injected in the unit (instantaneously or in a constant rate with a pump) and NaI-scintillation detectors measured the output signal. The Fortran program TRACADORES was developed to analyze the response function of the units in form of residence times distribution curves (RTD), which represents the probability of an element of the material to interact with the unit, and calculate the mean residence time γ, the central moment of this distribution function. This fundamental parameter characterizes the tank and serves as a quantitative evaluation for its performance. With the radiotracer techniques was possible to identify dead zone, channeling, internal circulation of the solid phase inside the tanks. The technique represents a guideline for redesign a imperfect unit and eliminate the problem. (author)

  19. PySE: Software for extracting sources from radio images

    Science.gov (United States)

    Carbone, D.; Garsden, H.; Spreeuw, H.; Swinbank, J. D.; van der Horst, A. J.; Rowlinson, A.; Broderick, J. W.; Rol, E.; Law, C.; Molenaar, G.; Wijers, R. A. M. J.

    2018-04-01

    PySE is a Python software package for finding and measuring sources in radio telescope images. The software was designed to detect sources in the LOFAR telescope images, but can be used with images from other radio telescopes as well. We introduce the LOFAR Telescope, the context within which PySE was developed, the design of PySE, and describe how it is used. Detailed experiments on the validation and testing of PySE are then presented, along with results of performance testing. We discuss some of the current issues with the algorithms implemented in PySE and their interaction with LOFAR images, concluding with the current status of PySE and its future development.

  20. Synthesis and biodistribution of 75Se-dinonyl-diselenide

    International Nuclear Information System (INIS)

    Liu, Y.F.; Qian, H.Q.; Zhang, Q.X.; Wang, X.Y.; Sun, J.G.; Li, B.Z.; Zhang, W.J.

    1985-01-01

    Selenium-75-labelled dinonyl-diselenide, C 9 H 19 75 SeSeC 9 H 19 , was synthesized and identified. It was injected into white rats in order to observe the selenium distribution in the tissues using inorganic 75 SeO 2 as the control agent. The sequence order of the 75 Se-dinonyl-diselenide uptake by tissues was: pancreas, muscles, stomach, liver, kidneys, spleen, blood, lungs, heart, brain, eyes. A very high accumulation of 75 Se-dinonyl-diselenide in the pancreas was observed, similar to that of the pancreatic imaging agent 75 Se-methionine. Furthermore, the enzymatic activity of glutathione peroxidase in the case of organic diselenide injection was higher than that measured for selenite. Selenium of dinonyl-diselenide was more effective and retainable in the process of converting itself to selenium-containing enzyme via the metabolic reactions. It may be advisable to replace inorganic sodium selenite by organic selenium compounds. Sodium selenite has been widely used in the prevention of the Keshan disease in China. (author)

  1. PbSe nanocubes obtained by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: hrojasc@ipn.mx [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM (Mexico); Achimovicova, M. [Slovak Academy of Sciences, Institute of Geotechnics (Slovakia); Daneu, N. [Jozef Stefan Institute, Department for Nanostructured Materials (Slovenia); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN (Mexico)

    2012-06-15

    In this study, PbSe nanocubes were obtained by high-energy milling, and their optical properties were investigated by measuring the UV-VIS-IR spectra in the range of 200-2,000 nm. The optical absorption of all samples showed a strong UV emission band at 1.45 eV. Previously, to obtain only PbSe nanocubes, an intermediate phase was identified, PbSeO{sub 3}. Although both PbSeO{sub 3} and PbSe were traced through this study, a major effort is devoted to characterize the latter. To trace how chemical transitions evolve from precursors to PbSe, X-ray diffraction and Rietveld refinement were carried out. Therefore, the following parameters were evaluated as a function of milling time: phase percentages, area-to-volume ratio, average crystallite dimensions, specific surface area, and morphology changes. To corroborate previous findings, nitrogen adsorption and transmission electron microscopy techniques were used. All the set experimental results unambiguously confirm that crystallites show a cubic morphology, with its average crystallite size distribution being around 24 nm.

  2. Selective Cytotoxic Activity of Se-Methyl-Seleno-L-Cysteine- and Se-Polysaccharide-Containing Extracts from Shiitake Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

    Science.gov (United States)

    Klimaszewska, Marzenna; Górska, Sandra; Dawidowski, Maciej; Podsadni, Piotr; Szczepanska, Agnieszka; Orzechowska, Emilia; Kurpios-Piec, Dagmara; Grosicka-Maciag, Emilia; Rahden-Staroń, Iwonna; Turło, Jadwiga

    2017-01-01

    Numerous formulations derived from the shiitake medicinal mushroom, Lentinus edodes, demonstrate anticancer activities. We hypothesized that isolates from selenium (Se)-enriched mycelia of L. edodes would possess stronger cancer-preventive properties than current preparations. The aim of this study was to investigate whether the presence of Se-methyl-seleno-L-cysteine in mycelial extracts of L. edodes affects their cytotoxic activity (makes them stronger) or whether they are as effective as Se-containing polysaccharides. Extracts were prepared from Se-containing mycelia under various conditions and assayed for cytotoxic activity in cancer (PC3 and HeLa) and normal (HMEC-1) cell lines. The chemical composition of the extracts was examined; specifically, the amounts of potentially cytotoxic Se compounds (methylselenocysteine, selenomethionine, and Se-containing polysaccharides) were measured. The relationship between extract composition and biological activity was characterized. Mycelial cultures were cultivated in a 10-L bioreactor in medium enriched with sodium selenite. Mycelial extracts were prepared either at 100°C or at 4°C in acidic solution. Total Se content was determined using the atomic absorption spectrometry method, and methylselenocysteine and selenomethionine contents were measured using reverse-phase high-performance liquid chromatography. Protein, carbohydrate, and polyphenolic contents were determined with spectrophotometric methods, and Se-containing polysaccharides were measured with the use of precipitation. Anticancer activity of mycelial extracts was examined using the MTT cell viability assay. Extracts containing Se-methyl-seleno-L-cysteine or Se-polysaccharides prepared at 4°C and 100°C, respectively, display moderate, time-dependent, specific cytotoxic activity in HeLa and PC3 cell lines. The effect in HeLa cells is more pronounced in the extract prepared at 4°C than at 100°C. The effect is almost equal for the PC3 cell line. However

  3. Development of conductive nanotemplates on ZnSe

    International Nuclear Information System (INIS)

    Monaico, Eduard; Tiginyanu, Ion; Colibaba, Gleb; Nedeoglo, D.D.; Cojocaru, Ala; Foell, Helmut

    2011-01-01

    We demonstrate the possibility to fabricate arrays of pores oriented perpendicular and parallel to the top surface of the ZnSe nanotemplate. The control of material conductivity allows one to produce porous ZnSe samples with the mean pore diameter and characteristic skeleton wall thickness from several hundreds of nanometers to about 15 nm. In addition, electrochemical treatment of ZnSe single crystals using photoresist masks allows one to prepare buried porous structures with pores directed parallel to the top template surface, which is especially important for photonic applications.

  4. Thermoelectric Performance of Na-Doped GeSe

    NARCIS (Netherlands)

    Shaabani, Laaya; Aminorroaya-Yamini, Sima; Byrnes, Jacob; Akbar Nezhad, Ali; Blake, Graeme R

    2017-01-01

    Recently, hole-doped GeSe materials have been predicted to exhibit extraordinary thermoelectric performance owing largely to extremely low thermal conductivity. However, experimental research on the thermoelectric properties of GeSe has received less attention. Here, we have synthesized

  5. Formation and reconstruction of Se nanoislands at the surface of thin epitaxial ZnSe layers grown on GaAs substrates

    Energy Technology Data Exchange (ETDEWEB)

    Kozlovskiy, V. I.; Krivobok, V. S., E-mail: krivobok@lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Kuznetsov, P. I.; Nikolaev, S. N.; Onistchenko, E. E.; Pruchkina, A. A.; Temiryazev, A. G. [Russian Academy of Sciences, Kotel’nikov Institute of Radio-Engineering and Electronics (Russian Federation)

    2016-05-15

    Strained epitaxial ZnSe layers are grown on GaAs substrates by the method of vapor-phase epitaxy from metal-organic compounds. It is found that Se nanoislands with a density of 10{sup 8} to 10{sup 9} cm{sup –2} are formed at the surface of such layers. It is established that an increase in the size of Se islands and a decrease in their density take place after completion of growth. Annealing in a H{sub 2} atmosphere at a temperature higher than 260°C leads to the disappearance of Se islands and to a decrease in the surface roughness. It is shown that annealing does not lead to deterioration of the structural perfection of the epitaxial ZnSe films; rather, annealing gives rise to a decrease in the intensity of impurity–defect luminescence and to an increase in the intensity of intrinsic radiation near the bottom of the exciton band.

  6. Chemical synthesis of Cu2Se nanoparticles at room temperature

    International Nuclear Information System (INIS)

    Rong, Fengxia; Bai, Yan; Chen, Tianfeng; Zheng, Wenjie

    2012-01-01

    Graphical abstract: The Cu 2 Se nanoparticles were synthesized by a simple and rapid method at room temperature. The TEM and SEM images show that the Cu 2 Se nanoparticles were spherical. Highlights: ► Cu 2 Se nanoparticles were synthesized by the reaction of nanoSe 0 sol with Cu + ions. ► The Cu 2 Se nanoparticles were spherical with cubic structure and well crystallized. ► Optical and electrochemical properties of Cu 2 Se nanoparticles were observed. ► The formation mechanism of Cu 2 Se nanoparticles was proposed. -- Abstract: A simple and rapid method has been developed to synthesize cuprous selenide (Cu 2 Se) nanoparticles by the reaction of selenium nanoparticles sol with copper sulfate solution containing ascorbic acid at room temperature. Cu 2 Se nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray analysis (EDX). The results indicated that Cu 2 Se nanoparticles were cubic crystal structure and spherical with the diameter about 75 nm. The ultraviolet–visible absorption spectrum (UV–vis) and cyclic voltammetry of Cu 2 Se nanoparticles were also investigated. The optical band gap energy of Cu 2 Se nanoparticles was 1.94 eV. On the basis of a series of experiments and characterizations, the formation mechanism of Cu 2 Se nanoparticles was discussed.

  7. Electronic structure and superconductivity of FeSe-related superconductors.

    Science.gov (United States)

    Liu, Xu; Zhao, Lin; He, Shaolong; He, Junfeng; Liu, Defa; Mou, Daixiang; Shen, Bing; Hu, Yong; Huang, Jianwei; Zhou, X J

    2015-05-13

    FeSe superconductors and their related systems have attracted much attention in the study of iron-based superconductors owing to their simple crystal structure and peculiar electronic and physical properties. The bulk FeSe superconductor has a superconducting transition temperature (Tc) of ~8 K and it can be dramatically enhanced to 37 K at high pressure. On the other hand, its cousin system, FeTe, possesses a unique antiferromagnetic ground state but is non-superconducting. Substitution of Se with Te in the FeSe superconductor results in an enhancement of Tc up to 14.5 K and superconductivity can persist over a large composition range in the Fe(Se,Te) system. Intercalation of the FeSe superconductor leads to the discovery of the AxFe2-ySe2 (A = K, Cs and Tl) system that exhibits a Tc higher than 30 K and a unique electronic structure of the superconducting phase. A recent report of possible high temperature superconductivity in single-layer FeSe/SrTiO3 films with a Tc above 65 K has generated much excitement in the community. This pioneering work opens a door for interface superconductivity to explore for high Tc superconductors. The distinct electronic structure and superconducting gap, layer-dependent behavior and insulator-superconductor transition of the FeSe/SrTiO3 films provide critical information in understanding the superconductivity mechanism of iron-based superconductors. In this paper, we present a brief review of the investigation of the electronic structure and superconductivity of the FeSe superconductor and related systems, with a particular focus on the FeSe films.

  8. Exploration work function and optical properties of monolayer SnSe allotropes

    Science.gov (United States)

    Cui, Zhen; Wang, Xia; Ding, Yingchun; Li, Meiqin

    2018-02-01

    The work function and optical properties are investigated with density functional theory for three monolayer SnSe allotropes. The calculated results indicate that the α-SnSe, δ-SnSe, ε-SnSe are semiconductor with the band gaps of 0.90, 1.25, and 1.50 eV, respectively. Meanwhile, the work function of δ-SnSe is lower than α-SnSe and ε-SnSe, which indicates that the δ-SnSe can be prepared of photoemission and field emission nanodevices. More importantly, the α-SnSe, δ-SnSe, ε-SnSe with the large static dielectric constants are 4.22, 5.48, and 3.61, which demonstrate that the three monolayer SnSe allotropes can be fabricated the capacitor. In addition, the static refractive index of δ-SnSe is larger than α-SnSe and ε-SnSe. The different optical properties with three monolayer SnSe allotropes reveal that the allotropes can regulate the properties of the materials. Moreover, our researched results show that the three monolayer SnSe allotropes are sufficient for fabrication of optoelectronic nanodevices.

  9. Green synthesis of ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) using a new, rapid and room temperature photochemical approach

    Energy Technology Data Exchange (ETDEWEB)

    Molaei, M., E-mail: m.molaei@vru.ac.ir; Bahador, A.R.; Karimipour, M.

    2015-10-15

    In this work, ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) were synthesized using a one-pot, rapid and room temperature photochemical method. UV illumination provided the required energy for the chemical reactions. Synthesized NCs were characterized using X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), UV–vis and photoluminescence (PL) spectroscopy. XRD pattern indicated cubic zinc blende structure for ZnSe NCs and the TEM image indicated round-shaped particles, most of which had a diameter of about 3 nm. Band gap of ZnSe NCs was obtained as about 3.6 eV, which was decreased by increasing the illumination time. Synthesized NCs indicated intensive and narrow emission in the UV-blue area (370 nm) related to the excitonic recombination and a broad band emission with a peak located at about 490 nm originated from the DAP (donor–acceptor pairs) recombination. ZnS shell was grown on ZnSe cores using a reaction based on the photo-sensitivity of Na{sub 2}S{sub 2}O{sub 3}. For ZnSe@ZnS core–shell NCs, XRD diffraction peaks shifted to higher angles. TEM image indicated a shell around cores and most of the ZnSe@ZnS NCs have a diameter of about 5 nm. After the ZnS growth, ZnSe excitonic emission shifted to the longer wavelength and PL intensity was increased considerably. PL QY was obtained about 11% and 17% for ZnSe and ZnSe@ZnS core–shell QDs respectively. - Highlights: • A green photochemical approach was reported for synthesis of ZnSe NCs. • ZnS shell was grown around ZnSe using a new method. • Synthesis method was rapid, simple and at room temperature. • ZnSe NCs indicated a narrow UV-blue and a broad DAP emissions. • PL intensity was increased considerably by ZnS shell growth.

  10. Shell Thickness Dependence of Interparticle Energy Transfer in Core-Shell ZnSe/ZnSe Quantum Dots Doping with Europium

    Science.gov (United States)

    Liu, Ni; Li, Shuxin; Wang, Caifeng; Li, Jie

    2018-04-01

    Low-toxic core-shell ZnSe:Eu/ZnS quantum dots (QDs) were prepared through two steps in water solution: nucleation doping and epitaxial shell grown. The structural and morphological characteristics of ZnSe/ZnS:Eu QDs with different shell thickness were explored by transmission electron microscopy (TEM) and X-ray diffraction (XRD) results. The characteristic photoluminescence (PL) intensity of Eu ions was enhanced whereas that of band-edge luminescence and defect-related luminescence of ZnSe QDs was decreased with increasing shell thickness. The transformation of PL intensity revealed an efficient energy transfer process between ZnSe and Eu. The PL intensity ratio of Eu ions ( I 613) to ZnSe QDs ( I B ) under different shell thickness was systemically analyzed by PL spectra and time-resolved PL spectra. The obtained results were in agreement with the theory analysis results by the kinetic theory of energy transfer, revealing that energy was transmitted in the form of dipole-electric dipole interaction. This particular method of adjusting luminous via changing the shell thickness can provide valuable insights towards the fundamental understanding and application of QDs in the field of optoelectronics.

  11. Novel mechanical behaviors of wurtzite CdSe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Bing [Shanghai Normal University, Department of Physics (China); Chen, Li [MCPHS University, School of Arts and Sciences (United States); Xie, Yiqun; Feng, Jie; Ye, Xiang, E-mail: yexiang@shnu.edu.cn [Shanghai Normal University, Department of Physics (China)

    2015-09-15

    As an important semiconducting nanomaterial, CdSe nanowires have attracted much attention. Although many studies have been conducted in the electronic and optical properties of CdSe NWs, the mechanical properties of Wurtzite (WZ) CdSe nanowires remain unclear. Using molecular dynamics simulations, we have studied the tensile mechanical properties and behaviors of [0001]-oriented Wurtzite CdSe nanowires. By monitoring the stretching processes of CdSe nanowires, three distinct structures are found: the WZ wire, a body-centered tetragonal structure with four-atom rings (denoted as BCT-4), and a structure that consists of ten-atom rings with two four-atom rings (denoted as TAR-4) which is observed for the first time. Not only the elastic tensile characteristics are highly reversible under unloading, but a reverse transition between TAR-4 and BCT-4 is also observed. The stretching processes also have a strong dependence on temperature. A tubular structure similar to carbon nanotubes is observed at 150 K, a single-atom chain is formed at 300, 350 and 450 K, and a double-atom chain is found at 600 K. Our findings on tensile mechanical properties of WZ CdSe nanowires does not only provide inspiration to future study on other properties of CdSe nanomaterials but also help design and build efficient nanoscale devices.

  12. Los jóvenes se incomunican

    Directory of Open Access Journals (Sweden)

    Margarita Ferro

    2015-01-01

    Full Text Available Hace años los jóvenes se comunicaban y relacionaban con sus amigos del barrio o de la escuela por lo que desde pequeños desarrollaban una comunicación interpersonal fluida. Hoy los video-juegos han sustituido la amistad y se han transformado en elementos de la comunicación. La autora analiza el mundo del nintendo y su influencia en las personas

  13. Influência do emprego de areia de fundição residual nas propriedades no estado fresco e endurecido de misturas cimentícias

    Directory of Open Access Journals (Sweden)

    W. R. L da Silva

    Full Text Available A areia de fundição residual (AFR consiste em um resíduo arenoso proveniente dos moldes utilizados no processo de fundição de metais. O presente trabalho foi desenvolvido com o objetivo de avaliar a influência do uso da AFR nas propriedades concreto. Para tanto, utilizou-se cimento CPV-ARI RS, aditivo plastificante, AFR e areias fina, média natural e de britagem. As propriedades no estado fresco foram avaliadas através da determinação da consistência e teor de ar incorporado. No estado endurecido avaliou-se a resistência à compressão axial. Os resultados indicaram que o uso da AFR resulta no aumento do teor de ar incorporado, fissuração por reações expansivas e conseqüente redução de resistência. Visando investigar a origem das tendências observadas, realizou-se um estudo complementar empregando AFR de diferentes composições. Todavia, independente da composição utilizada, os resultados indicaram tendência semelhante à observada anteriormente. Por fim, considerando os materiais empregados nesta pesquisa, conclui-se que a utilização da AFR em concreto é inadequada, pois prejudica não apenas a resistência mecânica, mas também a durabilidade do material.

  14. Estratégias de instituições da sociedade civil no acesso a medicamentos para câncer de mama no SUS

    Directory of Open Access Journals (Sweden)

    Aline Scaramussa Deprá

    2015-07-01

    Full Text Available Esta pesquisa objetiva identificar e analisar as estratégias de instituições da sociedade civil dedicadas ao câncer de mama (ISC-CM no acesso a medicamentos no SUS e seus principais atores sociais. Utilizou-se a abordagem qualitativa, empregando-se os métodos de análise de redes sociais e bola-de-neve e as técnicas de observação participante e entrevistas semiestruturadas. A análise temática baseou-se nas categorias: acesso a medicamentos para tratamento de câncer de mama; relacionamento das ISC-CM com o Estado; relacionamento das ISC-CM com a indústria farmacêutica; e outras estratégias utilizadas por ISC-CM no acesso a medicamentos. Os resultados mostraram que as ISC-CM têm influenciado o acesso a medicamentos para câncer de mama no SUS e sua principal estratégia é a pressão sobre o Estado. A indústria farmacêutica patrocina algumas dessas instituições para fortalecê-las com o intuito de ampliar seu mercado. As principais dificuldades no acesso a medicamentos se referem à deficiência de serviços, à iniquidade dos tratamentos oferecidos, e à inclusão de tecnologias no SUS.

  15. Repercussões da ambiência hospitalar na perspectiva dos trabalhadores de limpeza

    Directory of Open Access Journals (Sweden)

    Elen Petean

    Full Text Available Objetivou-se compreender o trabalho de limpeza hospitalar da perspectiva dos trabalhadores e descrever, na visão deles, as repercussões da ambiência hospitalar sobre o seu cotidiano de vida e trabalho. É um estudo de caso de abordagem qualitativa, empregando a hermenêutica como apoio teórico-metodológico. Os dados foram colhidos por meio da observação não participante e de entrevista com cinco trabalhadoras da limpeza de um hospital universitário. A análise foi por meio de leituras, buscando-se as unidades de significados contidas na transcrição dos dados empíricos, que permitiu o desmembramento em duas categorias: o cotidiano do trabalho de limpeza hospitalar e os reflexos da terceirização na vida do trabalhador da limpeza hospitalar. No hospital estudado, predominou o trabalho feminino e a constante preocupação com os riscos à saúde, principalmente os riscos biológicos. A terceirização reflete-se diretamente sobre o trabalhador, causando-lhe a sensação de um menor valor social e humano. Aponta-se a necessidade dos hospitais oferecerem um ambiente mais acolhedor ao trabalhador terceirizado da limpeza, tão exigidos física e mentalmente.

  16. Assessoria Aberta com Viés Social: Um Estudo de Caso no Centro de Referência de Assistência Social

    Directory of Open Access Journals (Sweden)

    Suéllen Ramos

    2015-12-01

    Full Text Available O presente estudo teve por objetivo realizar uma análise sobre o Centro de Referência de Assistência Social (CRAS. O estudo transcorre a estrutura organizacional do CRAS e a política de assistência social na forma de proteção social básica, articulando como meio de mediação, da gestão-sociedade às assessorias abertas. Utilizou-se o método dialético para reconhecer a realidade e transpô-la como conhecimento de forma exploratória e descritiva, no contexto da abordagem qualitativa, empregando-se as técnicas de tipo de pesquisa bibliográfica, documental e entrevista. Os resultados obtidos apontam para três principais categorias: serviços, gestão do CRAS e gestão das assessorias abertas. Os diálogos entre a gestão social e o Secretariado Executivo se apresenta interdisciplinar de forma a preencher as lacunas que emergem ao se revelar a problemática existente no Centro de Referência de Assistência Social sob a perspectiva de que a sua gestão pode ser analisada através das assessorias abertas, com o objetivo de mostrar a articulação gestão-sociedade do CRAS sob a óptica dos conhecimentos transversais na área das assessorias.

  17. SeRLoc: Robust Localization for Wireless Sensor Networks

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2005-01-01

    .... We show that SeRLoc is robust against known attacks on WSNs such as the wormhole attack, the Sybil attack, and compromise of network entities and analytically compute the probability of success for each attack. We also compare the performance of SeRLoc with state-of-the-art range-independent localization schemes and show that SeRLoc has better performance.

  18. Nematicity, magnetism and superconductivity in FeSe.

    Science.gov (United States)

    Böhmer, Anna E; Kreisel, Andreas

    2018-01-17

    Iron-based superconductors are well known for their complex interplay between structure, magnetism and superconductivity. FeSe offers a particularly fascinating example. This material has been intensely discussed because of its extended nematic phase, whose relationship with magnetism is not obvious. Superconductivity in FeSe is highly tunable, with the superconducting transition temperature, T c , ranging from 8 K in bulk single crystals at ambient pressure to almost 40 K under pressure or in intercalated systems, and to even higher temperatures in thin films. In this topical review, we present an overview of nematicity, magnetism and superconductivity, and discuss the interplay of these phases in FeSe. We focus on bulk FeSe and the effects of physical pressure and chemical substitutions as tuning parameters. The experimental results are discussed in the context of the well-studied iron-pnictide superconductors and interpretations from theoretical approaches are presented.

  19. Lateral structure of (TiSe2)n(NbSe2)m superlattices

    International Nuclear Information System (INIS)

    Noh, M.; Shin, H.; Jeong, K.; Spear, J.; Johnson, D.C.; Kevan, S.D.; Warwick, T.

    1997-01-01

    The structures of a series of (TiSe 2 ) n (NbSe 2 ) m superlattices grown through controlled crystallization of designed multilayer reactants have been studied. X-ray diffraction of the data of the superlattices after crystallization show considerable preferred orientation, with the basal plane of the dichalcogenide structure parallel to the substrate to within 0.1 degree. Lattice refinement using the observed (00scr(l)) diffraction maxima yields lattice parameters along the c axis that are consistent with those expected based on the target superlattices and lattice parameters of the binary constituents. These (00scr(l)) diffraction data, however, contain no information about the crystalline structure in the ab plane of the superlattice associated with the preferred c-axis orientation. Off-specular x-ray diffraction (XRD), scanning electron microscopy, and scanning transmission x-ray microscopy (STXM) were used to explore the structure and homogeneity of the superlattices in the ab plane. XRD results rule out preferred long-range orientational order of the ab plane. Between grains, both the backscattered electron images and STXM images show grain domain structure in the ab plane with a characteristic grain domain size of approximately 50 μm. X-ray absorption microscopy in the STXM mode obtained at the Ti L 2,3 edge shows that the titanium in the superlattices is present as both octahedral Ti consistent with the TiSe 2 structure and metallic Ti. A comparison of the data obtained from these techniques highlights chemical information, which can be deduced on a submicrometer range from the space resolved spectra obtained using STXM. copyright 1997 American Institute of Physics

  20. Determinação do valor de referência do aluguel de imóveis residenciais empregando o Método TODIM

    Directory of Open Access Journals (Sweden)

    Luís Alberto Duncan Rangel

    2007-08-01

    Full Text Available As avaliações de alternativas em presença de múltiplos critérios, quantitativos e qualitativos, são realizadas nas mais diversas áreas. Este artigo apresenta um estudo dessa natureza, conduzido junto às imobiliárias da cidade de Volta Redonda, RJ, visando auxiliar a definição do valor de referência de aluguel de imóveis residenciais. Para isto, faz-se uso do método TODIM, do Apoio Multicritério à Decisão. Com a finalidade de obter os valores de referência o mais próximo possível dos valores de mercado, alguns imóveis que tinham acabado de ser alugados foram inseridos na pesquisa, conhecendo-se desta forma o seu valor de aluguel. Assim, ao empregar o Método TODIM para realizar a ordenação dos imóveis com diferentes características, em função dos critérios empregados na análise e de suas importâncias relativas para os decisores, obtém-se a ordenação de todos os imóveis, e, como conseqüência disto, chega-se às diversas faixas de valor de aluguel dos imóveis em estudo. Uma análise de sensibilidade dos resultados numéricos obtidos complementa o estudo.Setting rent reference values for residential housing units is normally performed under multiple, conflicting criteria. This article shows how the TODIM method of Multicriteria Decision Aiding can be of a significant help in that task. A case study was carried through in the city of Volta Redonda, in the State of Rio de Janeiro, Brazil. The TODIM method allows considering quantitative as well as qualitative evaluation criteria and is founded on Prospect Theory. In order to obtain a maximum adherence of rent reference values to market values, some housing units that had just been rent were taken into account in the study. The application of the TODIM method produced the ordering of all such housing units and then led to identifying ranges for rent. A sensitivity analysis complemented the study by providing useful insights on the numerical results that were

  1. Unusually large chemical potential shift in a degenerate semiconductor: Angle-resolved photoemission study of SnSe and Na-doped SnSe

    Science.gov (United States)

    Maeda, M.; Yamamoto, K.; Mizokawa, T.; Saini, N. L.; Arita, M.; Namatame, H.; Taniguchi, M.; Tan, G.; Zhao, L. D.; Kanatzidis, M. G.

    2018-03-01

    We have studied the electronic structure of SnSe and Na-doped SnSe by means of angle-resolved photoemission spectroscopy. The valence-band top reaches the Fermi level by the Na doping, indicating that Na-doped SnSe can be viewed as a degenerate semiconductor. However, in the Na-doped system, the chemical potential shift with temperature is unexpectedly large and is apparently inconsistent with the degenerate semiconductor picture. The large chemical potential shift and anomalous spectral shape are key ingredients for an understanding of the novel metallic state with the large thermoelectric performance in Na-doped SnSe.

  2. NaviSE: superenhancer navigator integrating epigenomics signal algebra.

    Science.gov (United States)

    Ascensión, Alex M; Arrospide-Elgarresta, Mikel; Izeta, Ander; Araúzo-Bravo, Marcos J

    2017-06-06

    Superenhancers are crucial structural genomic elements determining cell fate, and they are also involved in the determination of several diseases, such as cancer or neurodegeneration. Although there are pipelines which use independent pieces of software to predict the presence of superenhancers from genome-wide chromatin marks or DNA-interaction protein binding sites, there is not yet an integrated software tool that processes automatically algebra combinations of raw data sequencing into a comprehensive final annotated report of predicted superenhancers. We have developed NaviSE, a user-friendly streamlined tool which performs a fully-automated parallel processing of genome-wide epigenomics data from sequencing files into a final report, built with a comprehensive set of annotated files that are navigated through a graphic user interface dynamically generated by NaviSE. NaviSE also implements an 'epigenomics signal algebra' that allows the combination of multiple activation and repression epigenomics signals. NaviSE provides an interactive chromosomal landscaping of the locations of superenhancers, which can be navigated to obtain annotated information about superenhancer signal profile, associated genes, gene ontology enrichment analysis, motifs of transcription factor binding sites enriched in superenhancers, graphs of the metrics evaluating the superenhancers quality, protein-protein interaction networks and enriched metabolic pathways among other features. We have parallelised the most time-consuming tasks achieving a reduction up to 30% for a 15 CPUs machine. We have optimized the default parameters of NaviSE to facilitate its use. NaviSE allows different entry levels of data processing, from sra-fastq files to bed files; and unifies the processing of multiple replicates. NaviSE outperforms the more time-consuming processes required in a non-integrated pipeline. Alongside its high performance, NaviSE is able to provide biological insights, predicting cell

  3. Layer Structured Bismuth Selenides of Bi2Se3 and Bi3Se4 for High Energy and Flexible All-Solid-State Micro-Supercapacitors.

    Science.gov (United States)

    Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

    2017-12-20

    Bismuth selenides (Bi2Se3 and Bi3Se4), both of which have the layered rhombohedral crystal structure, and found to be useful as electrode materials for supercapacitor application in this work. Bi2Se3 nanoplates as electrode material exhibit much better performance than that of Bi3Se4 nanoparticles in liquid electrolyte system (6 M KOH), which delivers a higher specific capacitance (272.9 F/g) than that of Bi3Se4 (193.6 F/g) at 5 mV/s. This result would may be attributed to that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to its planar quintuple stacked layers (septuple layers for Bi3Se4). For the demand of electronic skin, we used a novel flexible annular interdigital structure electrode applying for all-solid-state micro-supercapacitors (AMSCs). Bi2Se3 AMSCs device delivers a much more excellent supercapacitor performance, exhibits a large stack capacitance 89.5 F/cm3 (Bi3Se4: 79.1 F/cm3) at 20 mV/s, a high energy density 17.9 mWh/cm3 and high power density 18.9 W/cm3. The bismuth selenides also exhibit good cycle stability, retention 95.5% (90.3%) after 1000 c for Bi2Se3 (Bi3Se4). Obviously, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital all-solid-sate supercapacitor. © 2017 IOP Publishing Ltd.

  4. Absorbed dose to man from the Se-75 labeled conjugated bile salt SeHCAT: concise communication

    International Nuclear Information System (INIS)

    Soundy, R.G.; Simpson, J.D.; Ross, H.M.; Merrick, M.V.

    1982-01-01

    The absorbed radiation dose that would result from the oral or intravenous administration of SeHCAT (23-[ 75 Se]selena-25-homotaurocholate) has been calculated using the MIRD tables and formulas and data from measurements of whole-body distribution and from long-term whole-body counting in rats, mice, and man. When SeHCAT is administered to normal subjects, the gallbladder is the critical organ, receiving 12 mrad (oral dose) or 22 mrad (i.v.) per microcurie. The whole-body dose is 1 mrad/μCi, whatever the route of administration. In severe hepatic failure the liver might receive 200 mrad/μCi. The activity likely to be used in routine clinical practice is 10 μCi. Where a whole-body counter is used, an activity of 1 μCi has proved adequate. Even at an administered activity of 25 μCi, the absorbed dose is small compared with established techniques of investigating the gastrointestinal tract

  5. Absorbed dose to man from the Se-75 labeled conjugated bile salt SeHCAT: concise communication

    International Nuclear Information System (INIS)

    Soundy, R.G.; Simpson, J.D.; Ross, H.M.; Merrick, M.V.

    1982-01-01

    The absorbed radiation dose that would result from the oral or intravenous administration of SeHCAT (23-[75Se]selena-25-homotaurocholate) has been calculated using the MIRD tables and formulas and data from measurements of whole-body distribution and from long-term whole-body counting in rats, mice, and man. When SeHCAT is administered to normal subjects, the gallbladder is the critical organ, receiving 12 mrad (oral dose) or 22 mrad (i.v.) per microcurie. The whole-body dose is 1 mrad/microCi, whatever the route of administration. In severe hepatic failure the liver might receive 200 mrad/microCi. The activity likely to be used in routine clinical practice is 10 microCi. Where a whole-body counter is used, an activity of 1 microCi has proved adequate. Even at an administered activity of 25 microCi, the absorbed dose is small compared with established techniques of investigating the gastrointestinal tract

  6. Structural manifestations of aging in Se-rich glasses

    Science.gov (United States)

    Dash, S.; Ravindren, S.; Chen, P.; Boolchand, P.

    2015-03-01

    We examine weakly cross-linked GexSe100-x (0%modulated DSC and Raman scattering experiments. Homogeneity of melts was carefully verified using FT-Raman line profiling. Upon aging at RT for 4 months, we find the width of the glass transition W(x) steadily decreasing from 10C at 7% Ge to 2C for pure Se. The 5-fold reduction of W(x) with a decrease of Ge content is accompanied by a 2-fold increase in the non-reversing enthalpy. Rejuvenation of the aged glasses changes W(x) from 15C at 7% Ge to 7C for pure Se. Tg is found to decrease upon rejuvenation with the difference (Tg(aged)-Tg(rejuv)) showing a maximum near 3% Ge and vanishing for pure Se and 6% of Ge, which are topological thresholds. These results in Se-rich glasses are consistent with aging induced decoupling of Se8 crowns and growth of extended range structural correlations between polymeric Sen chains due to lone pair interactions. At higher x, near 8-10% of Ge, eutectic effects are manifested. Work supported by NSF Grant DMR 08-53957.

  7. Social Set Visualizer (SoSeVi) II

    DEFF Research Database (Denmark)

    Flesch, Benjamin; Vatrapu, Ravi

    2016-01-01

    This paper reports the second iteration of the Social Set Visualizer (SoSeVi), a set theoretical visual analytics dashboard of big social data. In order to further demonstrate its usefulness in large-scale visual analytics tasks of individual and collective behavior of actors in social networks......, the current iteration of the Social Set Visualizer (SoSeVi) in version II builds on recent advancements in visualizing set intersections. The development of the SoSeVi dashboard involved cutting-edge open source visual analytics libraries (D3.js) and creation of new visualizations such as of actor mobility...

  8. Reversible ultrafast melting in bulk CdSe

    International Nuclear Information System (INIS)

    Wu, Wenzhi; He, Feng; Wang, Yaguo

    2016-01-01

    In this work, transient reflectivity changes in bulk CdSe have been measured with two-color femtosecond pump-probe spectroscopy under a wide range of pump fluences. Three regions of reflectivity change with pump fluences have been consistently revealed for excited carrier density, coherent phonon amplitude, and lattice temperature. For laser fluences from 13 to 19.3 mJ/cm 2 , ultrafast melting happens in first several picoseconds. This melting process is purely thermal and reversible. A complete phase transformation in bulk CdSe may be reached when the absorbed laser energy is localized long enough, as observed in nanocrystalline CdSe

  9. Transition probabilities in neutron-rich Se,8684

    Science.gov (United States)

    Litzinger, J.; Blazhev, A.; Dewald, A.; Didierjean, F.; Duchêne, G.; Fransen, C.; Lozeva, R.; Sieja, K.; Verney, D.; de Angelis, G.; Bazzacco, D.; Birkenbach, B.; Bottoni, S.; Bracco, A.; Braunroth, T.; Cederwall, B.; Corradi, L.; Crespi, F. C. L.; Désesquelles, P.; Eberth, J.; Ellinger, E.; Farnea, E.; Fioretto, E.; Gernhäuser, R.; Goasduff, A.; Görgen, A.; Gottardo, A.; Grebosz, J.; Hackstein, M.; Hess, H.; Ibrahim, F.; Jolie, J.; Jungclaus, A.; Kolos, K.; Korten, W.; Leoni, S.; Lunardi, S.; Maj, A.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatovic, T.; Million, B.; Möller, O.; Modamio, V.; Montagnoli, G.; Montanari, D.; Morales, A. I.; Napoli, D. R.; Niikura, M.; Pollarolo, G.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Sahin, E.; Salsac, M. D.; Scarlassara, F.; Söderström, P.-A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Theisen, Ch.; Valiente Dobón, J. J.; Vandone, V.; Vogt, A.

    2015-12-01

    Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich Se,8684 are investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was performed at the Istituto Nazionale di Fisica Nucleare (INFN) Laboratori Nazionali di Legnaro using the Cologne Plunger device for the RDDS technique and the AGATA Demonstrator array for the γ -ray detection coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 86Se the level lifetime of the yrast 21+ state and an upper limit for the lifetime of the 41+ state are determined for the first time. The results of 86Se are in agreement with previously reported predictions of large-scale shell-model calculations using Ni78-I and Ni78-II effective interactions. In addition, intrinsic shape parameters of lowest yrast states in 86Se are calculated. In semimagic 84Se level lifetimes of the yrast 41+ and 61+ states are determined for the first time. Large-scale shell-model calculations using effective interactions Ni78-II, JUN45, jj4b, and jj4pna are performed. The calculations describe B (E 2 ;21+→01+) and B (E 2 ;61+→41+) fairly well and point out problems in reproducing the experimental B (E 2 ;41+→21+) .

  10. Extraction, characterization and antioxidant activities of Se-enriched tea polysaccharides.

    Science.gov (United States)

    Wang, Yuanfeng; Li, Yongfu; Liu, Yangyang; Chen, Xueqing; Wei, Xinlin

    2015-01-01

    Se-polysaccharides from Se-enriched tea leaves were purified by DEAE-sepharose fast flow gel column (2.5×60cm) and three polysaccharide fractions (Se-TPS1, Se-TPS2, and Se-TPS3) were isolated and purified with yields of 6.5, 37.14, and 8.57%, respectively. The average sizes of Se-TPS1 and Se-TPS2 were determined by HPGPC system, with molecular weights of 1.1×10(5) and 2.4×10(5)Da, respectively. Se-TPS3 was a polysaccharide polymer with two peaks with molecular weights of 9.2×10(5) and 2.5×10(5)Da. Monosaccharide components analysis by ion chromatography revealed Se-polysaccharides were acidic polysaccharoses and different from each other in monosaccharide kinds and molar ratio. Elements of Se, C, H, N, S, and 14 kinds of mineral elements were analyzed by AFS, EA, and ICP-AES, respectively. Spectral analysis (IR and UV) indicated Se-polysaccharides were typical glycoproteins. Morphological analyses of the samples were determined by SEM and AFM. In addition, the DPPH and superoxide radicals scavenging activities were also discussed to assess antioxidant activities of the samples, and Se-polysaccharides showed higher antioxidant activities compared to the ordinary polysaccharides. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Atomic Defects and Doping of Monolayer NbSe2.

    Science.gov (United States)

    Nguyen, Lan; Komsa, Hannu-Pekka; Khestanova, Ekaterina; Kashtiban, Reza J; Peters, Jonathan J P; Lawlor, Sean; Sanchez, Ana M; Sloan, Jeremy; Gorbachev, Roman V; Grigorieva, Irina V; Krasheninnikov, Arkady V; Haigh, Sarah J

    2017-03-28

    We have investigated the structure of atomic defects within monolayer NbSe 2 encapsulated in graphene by combining atomic resolution transmission electron microscope imaging, density functional theory (DFT) calculations, and strain mapping using geometric phase analysis. We demonstrate the presence of stable Nb and Se monovacancies in monolayer material and reveal that Se monovacancies are the most frequently observed defects, consistent with DFT calculations of their formation energy. We reveal that adventitious impurities of C, N, and O can substitute into the NbSe 2 lattice stabilizing Se divacancies. We further observe evidence of Pt substitution into both Se and Nb vacancy sites. This knowledge of the character and relative frequency of different atomic defects provides the potential to better understand and control the unusual electronic and magnetic properties of this exciting two-dimensional material.

  12. Thermal analysis of chalcogenide glasses of the system (As/sub/2Se/sub/3)/sub/(1-x):(Tl/sub/2Se)/sub/x

    International Nuclear Information System (INIS)

    Majid, C.A.

    1987-01-01

    In this paper differential thermal analysis (DTA) measurements of chalcogenide glasses of the system (As/sub/2Se/sub/3)/sub/(1-x): (Tl/sub/2Se)/sub/x, with x=0, 0.125, 0.25 and 0.50 are reported. The glass-forming tendencies of these materials have been calculated. The glass-forming tendency of As/sub/2Se/sub/3 has been found to be the highest among the member glasses of this family of chalcogenides. It was found that the glass-forming tendency of As/sub/2Se/sub/3 decreasing gradually at the Tl/sub/2/Se concentration increases. Tl/sub/2Se additions lower the glass transition temperature T/sub/q and the area under the endothermic peak for glass transition temperature, suggesting a tendency for relatively weaker bonding and hence less stability of Tl-rich glass compositions. These studies show that Tl/sub/2Se concentrations result in glasses with progressively higher crystallization tendencies. (author)

  13. Tests for the absorption of /sup 75/Se-labelled homocholic acid conjugated with taurine (/sup 75/Se-HCAT)

    Energy Technology Data Exchange (ETDEWEB)

    Schroth, H.J.; Berberich, R.; Mueller, K.P.; Feifel, G.; Ecker, K.W.

    1985-05-01

    The absorption of selenomethionine Se 75-labelled homocholic acid conjugated with taurine (/sup 75/-SE-HCAT) was tested in 46 patients. Retention measurements using (1) an uncollimated gamma camera and (2) a measuring arrangement similar to a human-body counter were compared in order to obtain a quantitative assessment of the absorption capacity of the terminal ileum for bile acids. The retention curve obtained after the oral administration of the /sup 75/Se-labelled bile-acid analogue showed a monoexponential decline; in the case of unimpaired absorption, the half-life was greater than 2.5 days. When more than 30 cm of the ileum had been eliminated by inflammatory infection or resection, the measured half-life was below 0.5 days due to malabsorption. We also performed a quantitative determination of the hepatic secretion of /sup 75/-Se-HCAT into the gall bladder. If more than 80% of the activity administered is found in the gall bladder, disturbed absorption of bile acids in the terminal ileum can be excluded. Values smaller than 80%, however, do not provide proof of disturbed absorption.

  14. Symmetry effects in neutron scattering from isotopically enriched Se isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J.; Haouat, G.; McEllistrem, M. T.; Patin, Y.; Sigaud, J.; Cocu, F.

    1975-06-01

    Differential cross sections for neutron elastic and inelastic scattering from {sup 76}Se, {sup 78}Se, {sup 80}Se and {sup 82}Se, have been measured at 8-MeV incident neutron energy and from {sup 76}Se and {sup 82}Se at 6- and 10-MeV incident energies. The differences observed in the elastic scattering cross sections are interpretable as the effects of isospin term in the scattering potentials. A full analysis of the elastic scattering data are presented.

  15. Detailed Visualization of Phase Evolution during Rapid Formation of Cu(InGa)Se2 Photovoltaic Absorber from Mo/CuGa/In/Se Precursors.

    Science.gov (United States)

    Koo, Jaseok; Kim, Sammi; Cheon, Taehoon; Kim, Soo-Hyun; Kim, Woo Kyoung

    2018-03-02

    Amongst several processes which have been developed for the production of reliable chalcopyrite Cu(InGa)Se 2 photovoltaic absorbers, the 2-step metallization-selenization process is widely accepted as being suitable for industrial-scale application. Here we visualize the detailed thermal behavior and reaction pathways of constituent elements during commercially attractive rapid thermal processing of glass/Mo/CuGa/In/Se precursors on the basis of the results of systematic characterization of samples obtained from a series of quenching experiments with set-temperatures between 25 and 550 °C. It was confirmed that the Se layer crystallized and then melted between 250 and 350 °C, completely disappearing at 500 °C. The formation of CuInSe 2 and Cu(InGa)Se 2 was initiated at around 450 °C and 550 °C, respectively. It is suggested that pre-heat treatment to control crystallization of Se layer should be designed at 250-350 °C and Cu(InGa)Se 2 formation from CuGa/In/Se precursors can be completed within a timeframe of 6 min.

  16. Investigation of CuGaSe2/CuInSe2 double heterojunction interfaces grown by molecular beam epitaxy

    Directory of Open Access Journals (Sweden)

    Sathiabama Thiru

    2015-02-01

    Full Text Available In-situ reflection high-energy electron diffraction (RHEED observation and X-ray diffraction measurements were performed on heterojunction interfaces of CuGaSe2/CnInSe2/CuGaSe2 grown on GaAs (001 using migration-enhanced epitaxy. The streaky RHEED pattern and persistent RHEED intensity oscillations caused by the alternate deposition of migration-enhanced epitaxy sequence are observed and the growths of smooth surfaces are confirmed. RHEED observation results also confirmed constituent material interdiffusion at the heterointerface. Cross-sectional transmission electron microscopy showed a flat and abrupt heterointerface when the substrate temperature is as low as 400 °C. These have been confirmed even by X-ray diffraction and photoluminescence measurements.

  17. Effect of nonstoichiometry properties of CuInSe2

    International Nuclear Information System (INIS)

    Rogacheva, E.I.; Tavrina, T.V.

    1997-01-01

    The homogeneity area size of the CuInSe 2 semiconductor compound is determined by the (CuIn)-Se profile of the Cu-In-Se ternary system at 350 deg C. The microhardness and thermo-electromotive force dependences on Se content are studied after various kind of thermal treatment. Interpretation of the results obtained is given with and account of defects formation character by deviations from stoichiometry [ru

  18. Transient and modulated charge separation at CuInSe{sub 2}/C{sub 60} and CuInSe{sub 2}/ZnPc hybrid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Morzé, Natascha von, E-mail: natascha.von_morze@helmholtz-berlin.de; Dittrich, Thomas, E-mail: dittrich@helmholtz-berlin.de; Calvet, Wolfram, E-mail: wolfram.calvet@helmholtz-berlin.de; Lauermann, Iver, E-mail: iver.lauermann@helmholtz-berlin.de; Rusu, Marin, E-mail: rusu@helmholtz-berlin.de

    2017-02-28

    Highlights: • Surface physical properties of non- and Na-treated CuInSe{sub 2} layers studied. • Evidence of exciton dissociation and charge separation at CuInSe{sub 2}/ZnPc interface. • Strong band bending at the CuInSe{sub 2} surface in contact with C{sub 60} observed. • No evidence for exciton dissociation at the CuInSe{sub 2}/C{sub 60} interface found. • Cu-poor phase at CuInSe{sub 2}/organic interface crucial for charge separation. - Abstract: Spectral dependent charge transfer and exciton dissociation have been investigated at hybrid interfaces between inorganic polycrystalline CuInSe{sub 2} (untreated and Na-conditioned) thin films and organic C{sub 60} as well as zinc phthalocyanine (ZnPc) layers by transient and modulated surface photovoltage measurements. The stoichiometry and electronic properties of the bare CuInSe{sub 2} surface were characterized by photoelectron spectroscopy which revealed a Cu-poor phase with n-type features. After the deposition of the C{sub 60} layer, a strong band bending at the CuInSe{sub 2} surface was observed. Evidence for dissociation of excitons followed by charge separation was found at the CuInSe{sub 2}/ZnPc interface. The Cu-poor layer at the CuInSe{sub 2} surface was found to be crucial for transient and modulated charge separation at CuInSe{sub 2}/organic hybrid interfaces.

  19. SeO2 adsorption on CaO surface: DFT study on the adsorption of a single SeO2 molecule

    Science.gov (United States)

    Fan, Yaming; Zhuo, Yuqun; Lou, Yu; Zhu, Zhenwu; Li, Liangliang

    2017-08-01

    Selenium is a hazardous element in coal. During coal combustion, most of the selenium will convert to SeO2 in the flue gas. Ca-based adsorbents, especially CaO, have been considered as a potential sorbent to adsorb SeO2 due to its low cost. In this paper, the adsorption mechanisms of single SeO2 on CaO surface were investigated by density functional theory (DFT) calculation. Both the physisorption and chemisorption structures were determined. It has been identified that the adsorption of SeO2 on CaO surface is primarily chemisorption, while physisorption takes effects at the initial stage of the process. Under O2 atmosphere, selenate is hard to form. Most of the adsorption products are selenite. Additionally, the electron density maps were obtained to reveal the surface active sites. The partial density of states (PDOS) was calculated for analyzing the electronic structural change of SeO2 and CaO surface during adsorption. The results provide fundamental information of the adsorption process, which could be meaningful for the development of new absorbents.

  20. A geração de resíduos sólidos em um processo produtivo de uma indústria automobilística: uma contribuição para a redução

    Directory of Open Access Journals (Sweden)

    Cíntia Madureira Orth

    2014-06-01

    Full Text Available É sabido que a produção de resíduos industriais constitui uma das principais formas de degradação do meio ambiente. As indústrias têm empreendido um esforço crescente para tornarem seus processos produtivos menos agressivos, especialmente no que se refere à geração e gestão de resíduos sólidos. O objetivo desta pesquisa consistiu em estudar a geração de resíduos sólidos no processo produtivo de uma indústria automobilística, visando a apresentação de ações de redução. O estudo se deu por meio de observações in loco, registros fotográficos e cálculos da quantidade de resíduos sólidos gerados no processo de Moldagem e Acabamento em Plástico Reforçado com Fibra de Vidro. Constatou-se que a moldagem do tipo aberta, adotada pela fábrica, representa a principal fonte de geração de resíduos. Outra fonte refere-se ao desperdício de materiais, atribuído à falta de capacitação e de Educação Ambiental. Concluiu-se que a migração para um processo mais limpo e a adoção de um Programa de Educação Ambiental devem ser consideradas pela unidade fabril estudada.

  1. Detecção de DNA de Brucella spp. em amostras de sangue e de suabe vaginal ou prepucial de cães do município de Natal, Rio Grande do Norte, Brasil

    Directory of Open Access Journals (Sweden)

    Annielle Regina da Fonsêca Fernandes

    2013-06-01

    Full Text Available Objetivou-se com este trabalho detectar o DNA de Brucella spp. em amostras de sangue e de suabe vaginal ou prepucial de 80 cães sorologicamente positivos para brucelose pela prova de imunodifusão em gel de ágar (IDGA, no município de Natal, estado do Rio Grande do Norte, Brasil. Amostras de sangue total foram colhidas com anticoagulante (citrato de sódio juntamente com amostras de suabe vaginal e prepucial, para extração de DNA e posterior realização da reação em cadeia da polimerase (PCR empregando-se os primers ITS66 e ITS279. O DNA de Brucella spp. foi amplificado em seis animais, sendo um animal em ambas as amostras, dois cães em amostras de sangue e três em amostras de suabe do trato reprodutivo. Concluiu-se que a infecção por Brucella spp. está presente em cães no município de Natal, e que a detecção de DNA do agente em amostras de suabe do trato reprodutivo podem ser utilizadas como ferramenta suplementar no diagnóstico de brucelose canina.

  2. ELABORAÇÃO E CARACTERIZAÇÃO FÍSICO-QUIMICA E SENSORIAL DE ESTRUTURADOS DE POLPA CONCENTRADA DE ABACAXI

    Directory of Open Access Journals (Sweden)

    Johnatt Alan Rocha de OLIVEIRA

    2012-01-01

    Full Text Available Este trabalho teve por objetivo estudar o procedimento de estruturação de polpa concentrada de abacaxi, empregando-se diferentes hidrocoloides e altas concentrações de polpa de abacaxi. Os hidrocoloides utilizados foram: pectina de baixa metoxilação, gelatina, ágar-ágar e alginato de sódio. Utilizou-se como processo para concentração da polpa a desidratação osmótica e a concentração por evaporação á vácuo. O fruto in natura foi submetido a análises físico-químicas e para os estruturados foram realizadas análises físico-químicas e sensoriais. Os resultados mostraram ser possível obter estruturados a partir de polpa concentrada de abacaxi, com concentrações significativas de vitamina C, proteína e fibra. Quanto à análise sensorial, os estruturados de abacaxi obtiveram elevada aceitação por parte dos possíveis compradores, apresentando índices elevados de intenção de compra, com cerca de 90% dos provadores que afirmaram que certamente ou possivelmente comprariam o produto se o encontrassem à venda.

  3. Photoacoustic spectroscopy of thin films of As2S3, As2Se3 and GeSe2

    Indian Academy of Sciences (India)

    Photoacoustic spectroscopy (PAS) is one of the important branches of spectroscopy, which enables one to detect light-induced heat production following the absorption of pulsed radiation by the sample. As2S3, As2Se3 and GeSe2 exhibit a wide variety of photo-induced phenomena that enable them to be used as optical ...

  4. Cs2SeO4-UO2SeO4-H2O system at 25 deg C

    International Nuclear Information System (INIS)

    Serezhkina, L.B.; Serezhkin, V.N.

    1987-01-01

    Using the method of isothermal solubility at 25 deg C the interaction of cesium and uranyl selenates in aqueous solution is studied. Formation of congruently soluble Cs 2 UO 2 (SeO 4 ) 2 x2H 2 O and Cs 2 (UO 2 ) 2 x(SeO 4 ) 3 is ascertained, their crystallographic characteristics being determined

  5. Certificação ISO 9001:2015 e medição de desempenho: benefícios e desafios para implantação de um sistema de gestão robusto

    Directory of Open Access Journals (Sweden)

    José Henrique de Andrade

    2018-04-01

    Full Text Available O objetivo deste trabalho foi avaliar como a certificação na norma ABNT NBR ISO 9001:2015 pode ser combinada com a medição de desempenho a fim de se obter um sistema de gestão robusto. Nas últimas décadas as organizações têm enfrentado novas e constantes demandas provenientes do ambiente onde atuam, sejam elas de clientes, concorrentes e outras partes interessadas. A fim de responder essas demandas com eficiência e eficácia, cada vez mais, sistemas de gestão consistentes e alinhados ao novo cenário são necessários. Diante disto, no presente trabalho realizou-se uma revisão da literatura das certificações nos sistemas de medição e um estudo múltiplo de casos em duas empresas industriais do interior do estado de São Paulo. Como principais resultados observou-se que as empresas desfrutam de benefícios e desafios comuns relacionados aos temas e os autores recomendam a exploração dos pontos fortes das duas abordagens propostas, assim como a superação dos desafios observados, como forma de obter um sistema de gestão robusto.

  6. Uma questão para a educacão inclusiva: expor-se ou resguardar-se?

    Directory of Open Access Journals (Sweden)

    Marie Claire Sekkel

    Full Text Available Este artigo discute as relações entre os atores institucionais que participam de uma proposta de educação escolar inclusiva. Com essa finalidade, foram utilizados recortes dos dados coletados em uma pesquisa sobre a construção de ambientes inclusivos, realizada em uma escola municipal de educação infantil em São Paulo, no período de 2006 a 2008. Os dados foram organizados em torno da questão expor-se ou resguardar-se?, que dá visibilidade aos movimentos presentes nas relações institucionais. A pesquisa utilizou a etnografia como método de coleta de dados, e a análise foi feita com base no referencial da teoria crítica da sociedade. Os resultados apontam a presença do sentimento de ameaça, que gera a necessidade de resguardo, e também de situações de abertura à experiência no trabalho desenvolvido com as crianças, que pressupõem a necessidade de expor-se diante de si e do(s outro(s. Segundo autores da Escola de Frankfurt, a origem desse sentimento de ameaça é social, e o medo deve tornar-se consciente para que seus efeitos destrutivos para o indivíduo e para as relações sociais possam ser evitados. A abertura à experiência, por outro lado, é necessária para a produção de uma consciência verdadeira, que é o principal objetivo da educação segundo Theodor Adorno, e deve ser considerada elemento fundamental para os processos educacionais inclusivos.

  7. Novel red-emission of ternary ZnCdSe semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Shu-Ru, E-mail: srchung@nfu.edu.tw [National Formosa University, Graduate Institute of Materials Science and Green Energy Engineering (China); Wang, Kuan-Wen [National Central University, Institute of Materials Science and Engineering (China); Chen, Hong-Shuo; Chen, Hong-Hong [National Formosa University, Graduate Institute of Materials Science and Green Energy Engineering (China)

    2015-02-15

    The effect of chain lengths of fatty acids on the physical properties of CdSe and ZnCdSe semiconductor nanocrystals (NCs) synthesized by the colloidal chemistry procedure is investigated. The fatty acids, lauric acid (LA), and stearic acid (SA), with different lengths of carbon chains, are used to prepare CdSe and ZnCdSe NCs when hexyldecylamine (HDA) is applied as the sole surfactant. For CdSe–SA and ZnCdSe–SA, they have the same emission wavelength at 592 nm and the same particle size of 3.3 nm; however, their quantum yield (QY) is 75 and 16 %, respectively. In contrast, the emission wavelength of CdSe–LA and ZnCdSe–LA NCs is 609 and 615 nm, the particle size is about 3.5 and 4 nm under the same reaction time, and the QY of them are 33 and 59 %, respectively. The X-ray diffraction pattern shows that ZnCdSe NCs all have the wurtzite structure, and their main peaks are located between those of pure CdSe and ZnSe materials. The main phase of ZnCdSe–SA and ZnCdSe–LA is ZnSe and CdSe, respectively, implying that alloyed ZnCdSe NC can be prepared and ZnSe and CdSe phase can be promoted by SA and LA, respectively. Moreover, the QY of red-emission ZnCdSe–LA is higher than 50 %. These results suggest that the growth rate of CdSe as well as ZnCdSe NC can be enhanced by using LA as complex reagent and HDA as sole surfactant. It is expected that the reported effective synthetic strategy can be developed as a very practical, easy and not time-consuming approach to prepare red emissive NCs with high QY and high reproducibility.

  8. Novel red-emission of ternary ZnCdSe semiconductor nanocrystals

    International Nuclear Information System (INIS)

    Chung, Shu-Ru; Wang, Kuan-Wen; Chen, Hong-Shuo; Chen, Hong-Hong

    2015-01-01

    The effect of chain lengths of fatty acids on the physical properties of CdSe and ZnCdSe semiconductor nanocrystals (NCs) synthesized by the colloidal chemistry procedure is investigated. The fatty acids, lauric acid (LA), and stearic acid (SA), with different lengths of carbon chains, are used to prepare CdSe and ZnCdSe NCs when hexyldecylamine (HDA) is applied as the sole surfactant. For CdSe–SA and ZnCdSe–SA, they have the same emission wavelength at 592 nm and the same particle size of 3.3 nm; however, their quantum yield (QY) is 75 and 16 %, respectively. In contrast, the emission wavelength of CdSe–LA and ZnCdSe–LA NCs is 609 and 615 nm, the particle size is about 3.5 and 4 nm under the same reaction time, and the QY of them are 33 and 59 %, respectively. The X-ray diffraction pattern shows that ZnCdSe NCs all have the wurtzite structure, and their main peaks are located between those of pure CdSe and ZnSe materials. The main phase of ZnCdSe–SA and ZnCdSe–LA is ZnSe and CdSe, respectively, implying that alloyed ZnCdSe NC can be prepared and ZnSe and CdSe phase can be promoted by SA and LA, respectively. Moreover, the QY of red-emission ZnCdSe–LA is higher than 50 %. These results suggest that the growth rate of CdSe as well as ZnCdSe NC can be enhanced by using LA as complex reagent and HDA as sole surfactant. It is expected that the reported effective synthetic strategy can be developed as a very practical, easy and not time-consuming approach to prepare red emissive NCs with high QY and high reproducibility

  9. Electrochemical synthesis of nanostructured Se-doped SnS: Effect of Se-dopant on surface characterizations

    Science.gov (United States)

    Kafashan, Hosein; Azizieh, Mahdi; Balak, Zohre

    2017-07-01

    SnS1-xSex nanostructures with different Se-dopant concentrations were deposited on fluorine doped tin oxide (FTO) substrate through cathodic electrodeposition technique. The pH, temperature, applied potential (E), and deposition time remained were 2.1, 60 °C, -1 V, and 30 min, respectively. SnS1-xSex nanostructures were characterized using X-ray diffraction (XRD), field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), room temperature photoluminescence (PL), and UV-vis spectroscopy. The XRD patterns revealed that the SnS1-xSex nanostructures were polycrystalline with orthorhombic structure. FESEM showed various kinds of morphologies in SnS1-xSex nanostructures due to Se-doping. PL and UV-vis spectroscopy were used to evaluate the optical properties of SnS1-xSex thin films. The PL spectra of SnS1-xSex nanostructures displayed four emission peaks, those are a blue, a green, an orange, and a red emission. UV-vis spectra showed that the optical band gap energy (Eg) of SnS1-xSex nanostructures varied between 1.22-1.65 eV, due to Se-doping.

  10. The influence of thermal treatment and irradiation on specific resistance of (SnSe)1-x - (PrSe)x solid solutions

    International Nuclear Information System (INIS)

    Huseynov, J.I.; Murguzov, M.I.; Ismayilov, Sh.S.; Jafarov, T.A.

    2014-01-01

    Full text: It was studied some kinetic coefficients in cluding specific resistance of (SnSe) 1 -x - (PrSe) x solid solutions as well. Special interest was caused by composetions of above mentioned system for which the influence of irradiation and thermal treatment following this irradiation was explored. By its electric characteristics praseodymium monoselenide belongs to metals because a metallic link is formed among cation atoms in PrSe, at the expense of cohich praseodymium atoms possess an oxidation degree equalling to 3+

  11. Anisotropy in CdSe quantum rods

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liang-shi [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    The size-dependent optical and electronic properties of semiconductor nanocrystals have drawn much attention in the past decade, and have been very well understood for spherical ones. The advent of the synthetic methods to make rod-like CdSe nanocrystals with wurtzite structure has offered us a new opportunity to study their properties as functions of their shape. This dissertation includes three main parts: synthesis of CdSe nanorods with tightly controlled widths and lengths, their optical and dielectric properties, and their large-scale assembly, all of which are either directly or indirectly caused by the uniaxial crystallographic structure of wurtzite CdSe. The hexagonal wurtzite structure is believed to be the primary reason for the growth of CdSe nanorods. It represents itself in the kinetic stabilization of the rod-like particles over the spherical ones in the presence of phosphonic acids. By varying the composition of the surfactant mixture used for synthesis we have achieved tight control of the widths and lengths of the nanorods. The synthesis of monodisperse CdSe nanorods enables us to systematically study their size-dependent properties. For example, room temperature single particle fluorescence spectroscopy has shown that nanorods emit linearly polarized photoluminescence. Theoretical calculations have shown that it is due to the crossing between the two highest occupied electronic levels with increasing aspect ratio. We also measured the permanent electric dipole moment of the nanorods with transient electric birefringence technique. Experimental results on nanorods with different sizes show that the dipole moment is linear to the particle volume, indicating that it originates from the non-centrosymmetric hexagonal lattice. The elongation of the nanocrystals also results in the anisotropic inter-particle interaction. One of the consequences is the formation of liquid crystalline phases when the nanorods are dispersed in solvent to a high enough

  12. Electrodeposition of epitaxial CdSe on (111) gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Cachet, H.; Cortes, R.; Froment, M. [Universite Pierre et Marie Curie, Paris (France). Phys. des Liquides et Electrochimie; Etcheberry, A. [Institut Lavoisier (IREM) UMR CNRS C0173, Universite de Versailles- St Quentin en Yvelynes, 45 Avenue des Etats Unis, 78035, Versailles (France)

    2000-02-21

    Epitaxial growth of CdSe has been achieved on GaAs(111) by electrodeposition from an aqueous electrolyte. The structure of the film corresponds to the cubic modification of CdSe. The quality of epitaxy has been investigated by reflection high energy electron diffraction, transmission electron microscopy and X-ray diffraction techniques. By XPS measurements the chemistry of the CdSe/GaAs interface and the composition of CdSe are determined. (orig.)

  13. Obtenção de nanocompósito de EVA/sílica e caracterização por ressonância magnética nuclear no estado sólido Preparation of EVA/silica nanocomposites characterized with solid state nuclear magnetic resonance

    Directory of Open Access Journals (Sweden)

    Adriano A. Passos

    2011-01-01

    Full Text Available Nanocompósitos a base de poli(etileno-co-acetato de vinila (EVA e óxido de sílica (SiO2, com tamanho nanométrico da ordem de 40 nm, foram preparados via intercalação por solução, empregando clorofórmio como solvente. Os nanocompósitos foram caracterizados principalmente pela espectroscopia de ressonância magnética nuclear (RMN, empregando a análise dos núcleos de carbono-13 (matriz polimérica; silício-29 (nanopartícula e pela determinação do tempo de relaxação spin-rede do núcleo de hidrogênio no eixo rotatório (T1rH (matriz polimérica. Pelos dados de RMN foi observado que até cerca de 5% de sílica em massa obteve-se um nanocompósito polimérico com boa dispersão da sílica devido a uma forte interação entre a sílica e matriz de EVA.Nanocomposites of poly(ethylene-co-vinyl acetate/silica (SiO2 with dimensions of ca. 40 nm were prepared via solution intercalation employing chloroform as a solvent. They were mainly characterized with nuclear magnetic resonance spectroscopy (NMR employing carbon-13 (polymeric matrix, silicon-29 (nanoparticles and through the determination of the proton spin-lattice relaxation time in the rotating frame (T1rH (polymer matrix. From the NMR results it was inferred that up to 5% of silica in mass a well dispersed nanocomposite was obtained, owing to a strong interaction between silica and the EVA matrix.

  14. An x-ray study of InSe

    International Nuclear Information System (INIS)

    Nagpal, K.C.; Ali, Z.

    1975-01-01

    Complete X-ray powder pattern of InSe, so far not available to literature, has been analyzed. The layer structure is based on a rhombohedral lattice cell, with space group R 3m, a sub(o) = 4.0046 +- 0.0005 A, csub(o) = 25.960 +- 0.004 A, and atomic position in 3 (a) of the space group : Zsub(In) = +-0.0555, Zsub(se) = 2/3 +- 0.106. Extreme softness and initial observe-reverse orientation of the rhombohedral cell in adjacent parts of a crystal or in thin lamellae parallel to the basal cleavage planes appear to be the main factors responsible for the characteristic sets of sharp and diffuse lines in the powder patterns normally obtained. These and Gandolfi camera powder patterns for several crystals are given. Heat treatment of powders obtained through cold work has indicated that comparatively short duration of 'annealing' at 600 deg C improves the powder pattern to some extent, but longer periods give products consisting of other phases of the In-Se system with small amount of InSe. The relative proportion of free space over the InSe powders in capsules as well as the amount of cold work seem to be the two main factors affecting the decomposition of InSe and appearance of other phases. Large platy crystals, on the other hand, withstand the heat treatment for a longer time. Even they undergo drastic changes in the sructure on prolonged heating at 600 deg C, yielding hexagonal phases with a common csub(o) = 19.26 A and a sub(o) = 4.0 and 7.11 respectively. (author)

  15. Study of structural phase transition in KD3 (Se O3)2 and Na H3(Se O3)2 by EPR

    International Nuclear Information System (INIS)

    Silva, J.C.M. da.

    1988-01-01

    The electron paramagnetic resonance of Se O - 2 centers in KD 3 (Se O 3 ) 2 and Na H 3 (Se O 3 ) 2 was done in the temperature ranges of -170 0 C o +80 0 C and +25 0 C to -185 0 C, respectively. (A.C.A.S.)

  16. The system SnTe-InSe

    International Nuclear Information System (INIS)

    Gurshumov, A.P.; Alidzhanov, M.A.; Aliev, A.S.; Gadzhiev, T.G.; Mamedov, N.A.

    1986-01-01

    This paper discusses the nature of the interaction and physicochemical properties of the alloys of the system SnTe-InSe. The DTA was performed on an NTR-74 pyrometer, XPA on a Dron-2.0 diffractometer and MSA on an MIM-7 metallographic microscope. The microhardness of the samples was determined on a PMT-3 microhardness tester. The congruently melting compound SnInTeSe and solid solutions based on the starting components are formed in the system

  17. Electronic Properties of Graphene-PtSe2 Contacts.

    Science.gov (United States)

    Sattar, Shahid; Schwingenschlögl, Udo

    2017-05-10

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe 2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe 2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe 2 and a p-type Schottky contact with bilayer PtSe 2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  18. Electronic Properties of Graphene–PtSe2 Contacts

    KAUST Repository

    Sattar, Shahid

    2017-04-26

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe2 and a p-type Schottky contact with bilayer PtSe2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  19. Electronic Properties of Graphene–PtSe2 Contacts

    KAUST Repository

    Sattar, Shahid; Schwingenschlö gl, Udo

    2017-01-01

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe2 and a p-type Schottky contact with bilayer PtSe2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  20. Avaliação do potencial de compostos naturais (argila, turfa e carvão na remoção de chumbo e toxicidade de um efluente industrial

    Directory of Open Access Journals (Sweden)

    Richard Clayton Tomasella

    2015-06-01

    Full Text Available Métodos de tratamento avançado utilizando-se de materiais adsorventes alternativos podem substituir ou complementar tratamentos convencionais existentes, auxiliando na remoção de substâncias tóxicas provindas de diversos processos industriais. Espectrometria e testes biológicos (toxicidade aguda e crônica auxiliam no monitoramento dos rejeitos industriais, avaliando a eficiência desses sistemas alternativos de tratamento de efluentes. O trabalho objetivou promover a redução da concentração do chumbo (Pb e da toxicidade de um efluente industrial utilizando o potencial de compostos naturais (argilominerais e turfa e do carvão ativado (controle como adsorventes em ensaios em batelada. O carvão ativado permitiu remover 99,4% do Pb no efluente (15 min, e para os demais adsorventes a remoção ocorreu progressivamente até 24 horas, resultando em eficiências de remoção de 88,0% (argila do Vale do Paraíba - VP, 73,6% (argila de Ajapí - A e 63,5% (turfa. A toxicidade aguda foi completamente removida com a utilização do carvão ativado, enquanto eficiências de remoção maiores do que 50% foram obtidas utilizando compostos naturais. Efeito tóxico significativo não foi observado após o tratamento com o carvão ativado e argila VP com relação à toxicidade crônica. Os resultados indicam a possibilidade de utilização da argila VP como adsorvente de baixo custo comercial em métodos de tratamento avançado.

  1. The influence of CdSe and ZnSe nanoparticles on the optical properties of Sm{sup 3+} ions in lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mallur, Saisudha B.; Heidorn, William D.; Fatokun, Stephen O.; Joshi, Krishna D.; Bista, Sandip S.; Babu, Panakkattu K., E-mail: PK-Babu@wiu.edu [Western Illinois University, Department of Physics (United States)

    2017-03-15

    The effect of glass composition and the presence of CdSe/ZnSe nanoparticles (NPs) on the optical absorption and fluorescence of Sm-doped lead borate glasses are studied. Three sets of glass samples xPbO:(99.5-x) B{sub 2}O{sub 3}:0.5Sm{sub 2}O{sub 3}, x = 29.5–69.5 mol%, xPbO:(96.5-x) B{sub 2}O{sub 3}:0.5Sm{sub 2}O{sub 3}: 3CdSe/ZnSe, x = 36.5, and 56.5 mol% are prepared. NPs are grown by annealing these glasses just below the glass transition temperature. Average size of both types of NPs increases with annealing time; however, CdSe NPs grew to a larger size range (2 to 20 nm) compared to ZnSe NPs (1 to 16 nm). We analyzed the hypersensitive transition, intensity parameters, radiative transition probability, stimulated emission cross section (σ{sub p}), and the area ratio of the electric dipole/magnetic dipole transitions of Sm{sup 3+}. The intensity parameters show a minimum at 11 h annealing for 36.5 mol% and a maximum for the same annealing duration in 56.5 mol% PbO containing CdSe NPs. The σ{sub p} for 56.5 mol% of PbO with CdSe NPs is found to be a maximum when the average NP size is around 14 nm. ZnSe NPs containing glasses also show significant changes in σ{sub p} when the average particle size is ~16 nm, for 36.5 mol% PbO. Our results suggest that the optical properties of Sm{sup 3+} in lead borate glasses are sensitive to its electronic environment which can be modified by varying the base glass composition and/or incorporating large NPs of CdSe/ZnSe. The large σ{sub p} values that we observe for some of the glass compositions make them attractive materials for photonic devices and photovoltaic applications.

  2. Core–shell interaction and its impact on the optical absorption of pure and doped core-shell CdSe/ZnSe nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xinqin; Cui, Yingqi; Zeng, Qun; Yang, Mingli, E-mail: myang@scu.edu.cn [Institute of Atomic and Molecular Physics, Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610065 (China); Yu, Shengping [College of Chemistry and Environment Protection Engineering, Southwest University for Nationalities, Chengdu 610041 (China)

    2016-04-07

    The structural, electronic, and optical properties of core-shell nanoclusters, (CdSe){sub x}@(CdSe){sub y} and their Zn-substituted complexes of x = 2–4 and y = 16–28, were studied with density functional theory calculations. The substitution was applied in the cores, the shells, and/or the whole clusters. All these clusters are characterized by their core-shell structures in which the core-shell interaction was found different from those in core or in shell, as reflected by their bondlengths, volumes, and binding energies. Moreover, the core and shell combine together to compose a new cluster with electronic and optical properties different from those of separated individuals, as reflected by their HOMO-LUMO gaps and optical absorptions. With the substitution of Cd by Zn, the structural, electronic, and optical properties of clusters change regularly. The binding energy increases with Zn content, attributed to the strong Zn–Se bonding. For the same core/shell, the structure with a CdSe shell/core has a narrower gap than that with a ZnSe shell/core. The optical absorption spectra also change accordingly with Zn substitution. The peaks blueshift with increasing Zn concentration, accompanying with shape variations in case large number of Cd atoms are substituted. Our calculations reveal the core-shell interaction and its influence on the electronic and optical properties of the core-shell clusters, suggesting a composition–structure–property relationship for the design of core-shell CdSe and ZnSe nanoclusters.

  3. The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule.

    Science.gov (United States)

    Timoney, John F; Suther, Pranav; Velineni, Sridhar; Artiushin, Sergey C

    2014-01-01

    Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were significantly (P ≤ 0.02) greater compared to CF32 and SF463. The results indicate capsule and SeM are both required for resistance to phagocytosis and killing and that the anti-phagocytic property of SeM is greatly reduced in the absence of capsule.

  4. Electrodeposition and Thermoelectric Properties of Cu-Se Binary Compound Films

    Science.gov (United States)

    Yang, Mengqian; Shen, Zhengwu; Liu, Xiaoqing; Wang, Wei

    2016-03-01

    Cu-Se binary compound films have been prepared by electrodeposition from solutions containing CuSO4, H2SeO3, and H2SO4 and their composition, structure, and thermoelectric performance analyzed. Moving the depositing potential negatively increased the Cu content in the film, remarkably so for relatively low Cu2+ concentration in the solution. X-ray diffraction analysis showed that the phase composition of the films varied with their Cu content. Cu-Se binary compound films electrodeposited from solutions with different concentration ratios of CuSO4 to H2SeO3 showed two different phases: α-Cu2- x Se (monoclinic) with Se content in the range of 33.3 at.% to 33.8 at.%, and β-Cu2Se (cubic) with Se content in the range of 35.3 at.% to 36.0 at.%. The highest power factor for electrodeposited Cu2- x Se film was 0.13 mW/(K2 m) with Seebeck coefficient of 56.0 μV/K.

  5. Formation and properties of epitaxial CdSe, ZnSe quantum dots. Conventional molecular beam epitaxy and related techniques

    International Nuclear Information System (INIS)

    Mahapatra, Suddhasatta

    2008-01-01

    This thesis systematically investigates three such alternative approaches, along with conventional MBE, with emphasis on the formation-mechanism of QDs, and optimization of their morphological and optical attributes. it is shown here that no distinct 3D islands are formed in MBE growth of CdSe on ZnSe. While CdSe heteroepitaxy occurs in the multilayer-mode at T G =300 C, a reentrant recovery of the layer-by-layer mode is reported in this thesis, for growth at T G D =230 C). The process steps of the third variant technique, developed in course of this work, are very similar to those of the previous one-the only alteration being the substitution of selenium with tellurium as the cap-forming-material. (orig.)

  6. SeO2 adsorption on CaO surface: DFT and experimental study on the adsorption of multiple SeO2 molecules

    Science.gov (United States)

    Fan, Yaming; Zhuo, Yuqun; Li, Liangliang

    2017-10-01

    SeO2 adsorption mechanisms on CaO surface were firstly investigated by both density functional theory (DFT) calculations and adsorption experiments. Adsorption of multiple SeO2 on the CaO (001) surface was investigated using slab model. Based on the results of adsorption energy and surface property, a double-layer adsorption mechanisms were proposed. In experiments, the SeO2 adsorption products were prepared in a U-shaped quartz reactor at 200 °C. The surface morphology was investigated by field emission scanning electron microscopy (FE-SEM). The superficial and total SeO2 mass fractions were measured by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES), respectively. The surface valence state and bulk structure are determined by XPS and X-Ray Diffraction (XRD). The experimental results are in good agreement with the DFT results. In conclusion, the fundamental SeO2 chemisorption mechanisms on CaO surface were suggested.

  7. Electroluminescence of colloidal ZnSe quantum dots

    International Nuclear Information System (INIS)

    Dey, S.C.; Nath, S.S.

    2011-01-01

    The article reports a green chemical synthesis of colloidal ZnSe quantum dots at a moderate temperature. The prepared colloid sample is characterised by UV-vis absorption spectroscopy and transmission electron microscopy. UV-vis spectroscopy reveals as-expected blue-shift with strong absorption edge at 400 nm and micrographs show a non-uniform size distribution of ZnSe quantum dots in the range 1-4 nm. Further, photoluminescence and electroluminescence spectroscopies are carried out to study optical emission. Each of the spectroscopies reveals two emission peaks, indicating band-to-band transition and defect related transition. From the luminescence studies, it can be inferred that the recombination of electrons and holes resulting from interband transition causes violet emission and the recombination of a photon generated hole with a charged state of Zn-vacancy gives blue emission. Meanwhile electroluminescence study suggests the application of ZnSe quantum dots as an efficient light emitting device with the advantage of colour tuning (violet-blue-violet). - Highlights: → Synthesis of ZnSe quantum dots by a green chemical route. → Characterisation: UV-vis absorption spectroscopy and transmission electron microscopy. → Analysis of UV-vis absorption spectrum and transmission electron micrographs. → Study of electro-optical properties by photoluminescence and electroluminescence. → Conclusion: ZnSe quantum dots can be used as LED with dual colour emission.

  8. Crystal structure, Raman scattering and magnetic properties of CuCr2-xZrxSe4 and CuCr2-xSnxSe4 selenospinels

    Science.gov (United States)

    Pinto, C.; Galdámez, A.; Barahona, P.; Moris, S.; Peña, O.

    2018-06-01

    Selenospinels, CuCr2-xMxSe4 (M = Zr and Sn), were synthesized via conventional solid-state reactions. The crystal structure of CuCr1.5Sn0.5Se4, CuCr1.7Sn0.3Se4, CuCr1.5Zr0.5Se4, and CuCr1.8Zr0.2Se4 were determined using single-crystal X-ray diffraction. All the phases crystallized in a cubic spinel-type structure. The chemical compositions of the single-crystals were examined using energy-dispersive X-ray analysis (EDS). Powder X-ray diffraction patterns of CuCr1.3Sn0.7Se4 and CuCr1.7Sn0.3Se4 were consistent with phases belonging to the Fd 3 bar m Space group. An analysis of the vibrational properties on the single-crystals was performed using Raman scattering measurements. The magnetic properties showed a spin glass behavior with increasing Sn content and ferromagnetic order for CuCr1.7Sn0.3Se4.

  9. The absolute age of SE-RF-6 (Ngamanie) and its relation to SE-RF-2 (Nenumbo) : two decorated lapita sites in the southeast Solomon Islands

    International Nuclear Information System (INIS)

    Green, R.C.; Jones, M.

    2007-01-01

    The relative age of SE-RF-6, SE-RF-2 and SE-SZ-8, three decorative phase Lapita sites in the Reef/Santa Cruz region of the Outer Easter Islands of Solomon Islands, has been the subject of dispute. A review of the evidence recovered from SE-RF-6 (Ngamanie), in conjunction with a Bayesian calibration model, supports the notion that it postdates the nearby site of SE-RF-2 (Nenumbo). We conclude that the SE-RF-6 represents an occupation of 50 to 100 years duration (compared with 50 or less for SE-RF-2), beginning some time in the interval 2470-2910 BP. (author). 22 refs., 4 figs., 3 tabs

  10. Raman scattering and structural analysis of electrodeposited CuInSe{sub 2} and S-rich quaternary CuIn(S,Se){sub 2} semiconductors for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo-Roca, Victor; Fontane, Xavier; Morante, Joan Ramon [Departament d' Electronica, Universitat de Barcelona (Spain); Saucedo, Edgardo; Ruiz, Carmen M.; Grand, Pierre-Philippe; Jaime-Ferrer, Jesus Salvador; Bermudez, Veronica [Institut de Recherche et Developement sur l' Energie Photovoltaique (IRDEP), Chatou (France); Calvo-Barrio, Lorenzo [Departament d' Electronica, Universitat de Barcelona (Spain); Lab. Analisis de Superficies, SCT, Universitat de Barcelona (Spain); Alvarez-Garcia, Jacobo [Centre de Recerca i Investigacio de Catalunya (CRIC), Barcelona (Spain); Perez-Rodriguez, Alejandro

    2009-05-15

    This work reports the Raman scattering characterisation of CuInSe{sub 2} precursors grown by single step electrodeposition and the corresponding layers recrystallised under sulphurising conditions for solar cell devices. The analysis of the spectra measured on the as-grown precursors has allowed identifying the main secondary phases in these layers with elemental Se, Cu-Se phases and chalcopyrite Cu-poor ordered vacancy domains. To deepen in the identification of the Cu-Se phases, these measurements have been correlated with the analysis of binary Cu-Se layers. The experimental data indicate that formation of both Se and Cu-Se phases is likely controlled by the Se content in the layers. For values of stoichiometry below 1.15, excess Cu in the layers is accommodated in a phase with very low Raman efficiency (as Cu{sub 2}Se). Increasing the content of Se leads to an increase in the spectral contribution from both Se and Cu{sub 2-x}Se, being the formation of these phases likely favoured under high excess Se conditions. The characterisation of the corresponding recrystallised layers has allowed analysing the impact of the presence of the secondary phases in the as-grown absorbers on the performance of the final solar cells. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Properties of different temperature annealed Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films prepared by RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Yu Zhou; Liu Lian; Yan Yong; Zhang Yanxia; Li Shasha; Yan Chuanpeng; Zhang Yong [Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education of China, Superconductivity and New Energy R and D Center (SNERDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhao Yong, E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education of China, Superconductivity and New Energy R and D Center (SNERDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The Cu(In,Ga)Se{sub 2} and Cu(In,Ga)2Se{sub 3.5} films follow different process to form CIGS phase. Black-Right-Pointing-Pointer Composition loss of the annealed Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films are different. Black-Right-Pointing-Pointer Hexagonal CuSe phase exhibits unique transport feature. Black-Right-Pointing-Pointer Conductivity of the CIGS films is affected by the 'variable range hopping' mechanism. - Abstract: We have investigated the effect of annealing temperature on structural, compositional, electrical properties of the one-step RF sputtered Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films. After the annealing at various temperatures, loss of Se element is significant for the Cu(In,Ga)Se{sub 2} films and meanwhile composition of the annealed Cu(In,Ga){sub 2}Se{sub 3.5} films keeps almost constant. The as-deposited Cu(In,Ga)Se{sub 2} and Cu(In,Ga){sub 2}Se{sub 3.5} films show amorphous structure and they follow different transformation process to form chalcopyrite structure. Electrical conductivity of the annealed CIGS films related to their chemical composition. Cu(In,Ga)Se{sub 2} films annealed at 150 Degree-Sign C show unique electron transport mechanism for the formation of hexagonal CuSe phase. Electrical conductivity of the chalcopyrite structure films are dominated by the 'variable range hopping' transport mechanism. The annealed Cu(In,Ga){sub 2}Se{sub 3.5} films present higher density of disorders than the annealed Cu(In,Ga)Se{sub 2} films for their significant Cu deficient composition.

  12. Fe-vacancy and superconductivity in FeSe-based superconductors

    Science.gov (United States)

    Wang, C. H.; Chen, T. K.; Chang, C. C.; Lee, Y. C.; Wang, M. J.; Huang, K. C.; Wu, P. M.; Wu, M. K.

    2018-06-01

    This review summarizes recent advancements in FeSe and related systems. The FeSe and related superconductors are currently receiving considerable attention for the high Tcs observed and for many similar features to the high Tc cuprate superconductors. These similarities suggest that understanding the FeSe based compounds could potentially help our understanding of the cuprates. We shall first review the common features observed in the FeSe-based system. It was found that with a careful control of material synthesizing processes, numerous rich phases have been observed in the FeSe-based system. Detailed studies show that the Fe-vacancy ordered phases found in the FeSe based compounds, which are non-superconducting Mott insulators, are the parent compounds of the superconductors. Superconductivity emerges from the parent phases by disordering the Fe vacancy order, often by a simple annealing treatment. Recent high temperature X-ray diffraction experiments show that the degree of structural distortion associated with the disorder of Fe-vacancy is closely related to volume fraction of the superconductivity observed. These results suggest the strong lattice to spin coupling are important for the occurrence of superconductivity in FeSe based superconductors.

  13. ¿Qué se juega al jugar un juego?

    Directory of Open Access Journals (Sweden)

    Kalejman, Cecilia

    2012-06-01

    Full Text Available En el presente artículo se considera el juego en relación a la niñez. Se indaga acerca del papel que juega el juego en la niñez intentando responder a diversas preguntas, entre ellas la más importante: ¿Qué significa jugar? A lo largo de esta etapa del desarrollo en que comienza a constituirse la subjetividad del individuo el juego constituye, sin dudas, un factor central, una herramienta fundamental en el desarrollo. Juego no es sólo el juego dramático, también consideramos para nuestro análisis aquellas modalidades de juego que se transmiten de generación en generación, juegos de construcción, los dibujos, teniendo en cuenta asimismo los objetos utilizados en los juegos, los contenidos de los mismos, los espacios en los que se desarrollan. Se piensa y se interpreta al juego, como un derecho y como un modo de expresión del niño, se finaliza este desarrollo con una conclusión acera del juego y el espacio que ocupa en la vida cotidiana.

  14. Internationalization of companies in industrial clusters: a study of medical, dental and hospital supply industries in Ribeirão Preto - SP Internacionalización de empresas en clusters industriales: un estudio aplicado en el polo médico-hospitalar-odontológico de Ribeirão Preto - SP Internacionalização de empresas em clusters industriais: um estudo aplicado no polo médico-hospitalar-odontológioco de Ribeirão Preto - SP

    Directory of Open Access Journals (Sweden)

    Gustavo Barbieri Lima

    2011-03-01

    resultados, se puede mencionar: (a las empresas de la región se muestran altamente favorables al proceso de internacionalización, y ese polo ya puede ser caracterizado como exportador; (b la cooperación ínter organizacional fue apuntada por el Sebrae-SP como de suma importancia no sólo para la sobrevivencia de las micro y pequeñas empresas monitoreadas, como también para su introducción en mercados internacionales y el incremento de las exportacionesUma tendência, tanto em âmbito nacional quanto internacional, tem sido evidenciada em pesquisas acadêmicas, assim como nos meios empresariais e governamentais: a de empresas, especialmente micro, pequenas e médias, procurarem se organizar em redes estratégicas de cooperação interorganizacionais, para se manterem competitivas nos mercados em que atuam ou mesmo para assegurar sua sobrevivência ante a acirrada competição advinda do processo denominado globalização de mercados. O objetivo geral do presente estudo é investigar as interligações do processo de internacionalização que permitem às micro e pequenas empresas cooperarem em clusters industriais ou arranjos produtivos locais, em contraponto à inserção individual das empresas nos mercados internacionais. Utilizou-se o método de estudo de caso para a realização da presente pesquisa. Como resultados, podem-se mencionar: (a as empresas da região se posicionam altamente favoráveis ao processo de internacionalização, e esse polo já pode ser caracterizado como exportador; (b a cooperação interorganizacional foi apontada pelo Sebrae-SP como de suma importância não só para a sobrevivência das micro e pequenas empresas monitoradas, como também para sua inserção em mercados internacionais e o incremento das exportações

  15. Low temperature magnetic structure of MnSe

    Indian Academy of Sciences (India)

    Abstract. In this paper we report low temperature neutron diffraction studies on MnSe in order to understand the anomalous behaviour of their magnetic and transport prop- erties. Our study indicates that at low temperatures MnSe has two coexisting crystal structures, high temperature NaCl and hexagonal NiAs. NiAs phase ...

  16. Thermoelectric properties of SnSe compound

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Xinhong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Lu, Pengfei, E-mail: photon@bupt.edu.cn [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Wu, Liyuan; Han, Lihong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Liu, Gang [School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Song, Yuxin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Photonics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Gothenburg (Sweden)

    2015-09-15

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data.

  17. Thermoelectric properties of SnSe compound

    International Nuclear Information System (INIS)

    Guan, Xinhong; Lu, Pengfei; Wu, Liyuan; Han, Lihong; Liu, Gang; Song, Yuxin; Wang, Shumin

    2015-01-01

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data

  18. ARTESANATO NO E PARA O MERCADO: AS REDES DE PRODUÇÃO E COMERCIALIZAÇÃO DOS ARTESANATOS DAS FEIRAS HIPPIE E DO CERRADO DE GOIÂNIA - GO

    Directory of Open Access Journals (Sweden)

    Cristiana Andrade Fernandes

    2010-08-01

    Full Text Available Artesanato são peças feitas com técnicas manuais e que pressupõem ausência de auxílio de máquinas industriais. A aceleração do consumo propiciada pela globalização, o constante avanço da tecnologia, a indústria cultural e o turismo são alguns fatores que alteram o artesanato na medida em que há o risco de padronização dos objetos e conseqüente modificação no seu significado e sentido. Considerando-se tais pressupostos, analisa-se o comércio e a produção, ou seja, o artesanato no e para o mercado tendo como foco aquele exposto nas feiras Hippie e do Cerrado em Goiânia, recuperando-se suas redes organizacionais. A pesquisa justifica-se pela carência de produção geográfica versando sobre esta atividade, apesar de sua relevância, já que comumente, mesmo nas viagens de curta distância, não há quem não compre uma “lembrancinha�? ou não se admire com a habilidade de alguém para produzir tal ou qual objeto, ao circular por uma feira. Metodologicamente, recorrem-se às técnicas de observação e entrevista com questionários estruturados e semi-estruturados aplicados em trabalhos de campo, além das análises documental e bibliográfica.

  19. Epitaxial CdSe-Au nanocrystal heterostructures by thermal annealing.

    Science.gov (United States)

    Figuerola, Albert; van Huis, Marijn; Zanella, Marco; Genovese, Alessandro; Marras, Sergio; Falqui, Andrea; Zandbergen, Henny W; Cingolani, Roberto; Manna, Liberato

    2010-08-11

    The thermal evolution of a collection of heterogeneous CdSe-Au nanosystems (Au-decorated CdSe nanorods, networks, vertical assemblies) prepared by wet-chemical approaches was monitored in situ in the transmission electron microscope. In contrast to interfaces that are formed during kinetically controlled wet chemical synthesis, heating under vacuum conditions results in distinct and well-defined CdSe/Au interfaces, located at the CdSe polar surfaces. The high quality of these interfaces should make the heterostructures more suitable for use in nanoscale electronic devices.

  20. Synthesis, field emission properties and optical properties of ZnSe nanoflowers

    Energy Technology Data Exchange (ETDEWEB)

    Xue, S.L., E-mail: slxue@dhu.edu.cn [Department of Applied Physics, College of Science, Donghua University, Shanghai 201620 (China); Wu, S.X.; Zeng, Q.Z.; Xie, P.; Gan, K.X.; Wei, J.; Bu, S.Y.; Ye, X.N.; Xie, L. [Department of Applied Physics, College of Science, Donghua University, Shanghai 201620 (China); Zou, R.J. [State Key Laboratory for Modification and Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); Zhang, C.M.; Zhu, P.F. [Department of Physics, School of Fundamental Studies, Shanghai University of Engineering Science, Shanghai 201620 (China)

    2016-03-01

    Graphical abstract: Unique ZnSe nanoflowers have been successfully synthesized by reaction of Se powder with Zn substrates. They are characterized by XRD, SEM, TEM, XPS, EDS and Raman spectroscopy and were single crystals with cubic zinc blende (ZB) structure. They also have excellent field emission properties and optical properties. - Highlights: • Novel ZnSe nanoflowers are grown on Zn foils. • ZnSe nanoflowers are characterized by XRD, SEM, TEM, XPS and Raman spectra. • ZnSe nanoflowers on Zn foils as cathodes possess good FE properties. - Abstract: ZnSe nanoflowers have been synthesized by reaction of Se powder with Zn substrates at low temperature. The as-prepared ZnSe nanoflowers were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray energy dispersive spectroscope (EDS) and Raman spectroscopy measurements. It was found that the morphologies of the as-prepared samples highly depended on reaction time. ZnSe nanoclusters and nanoflowers formed at 573 K when the reaction time was 20 and 60 min, respectively. The as-prepared ZnSe nanoflowers were composed of radically aligned ZnSe nanorods with smooth surfaces. The results of XRD, XPS, EDS, TEM and Raman showed that the as-prepared ZnSe nanocrystals were single crystals with cubic zinc blende (ZB) structure. The formation mechanism of the as-prepared ZnSe nanoflowers was also discussed. In addition, the as-prepared ZnSe nanoflowers had excellent electron emission properties. The turn-on field of the as-prepared ZnSe nanoflowers was 3.5 V/μm and the enhancement factor was 3499. The optical properties of the as-prepared ZnSe nanoflowers were also investigated. The results demonstrated that the as-prepared ZnSe nanoflowers were potential candidates for optoelectronic devices.