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Sample records for molde aberto para

  1. Tecnologias de dados abertos para interligar bibliotecas, arquivos e museus: um caso machadiano

    Directory of Open Access Journals (Sweden)

    Antonio Laurindo dos Santos Neto

    Full Text Available O artigo propõe um caso fictício para ilustrar o uso das tecnologias de Dados Abertos Interligados como mecanismos para tornar interoperáveis informações em acervos de bibliotecas, arquivos e museus, utilizando como exemplo as informações sobre o escritor Machado de Assis e sua obra. Utilizou-se como método o estudo de um caso restrito e ilustrativo, não exaustivo. Aplicaram-se diferentes vocabulários para interligação dos dados e para sua representação, utilizando os princípios do Linked Data; sugere-se que os profissionais da informação usufruam dessa potencialidade e busquem novas aplicações para ampliar a interoperabilidade dos dados disponíveis na Web.

  2. O espaço aberto da educação infantil: lugar para brincar e desenvolver-se

    Directory of Open Access Journals (Sweden)

    Luana dos Santos Raymundo

    2010-08-01

    Full Text Available Este estudo teve como objetivo principal identificar as características existentes nas configurações dos espaços abertos de instituições de educação infantil, relacionando os aspectos físicos com as brincadeiras desenvolvidas pelos seus usuários, recorrendo à aplicação da técnica do mapeamento comportamental. O estudo foi conduzido em dois contextos educativos do município de Florianópolis-SC, nos quais os participantes, crianças entre 3 e 5 anos, foram observados no período de recreação. A análise dos dados evidenciou a preferência de determinados equipamentos por seus usuários. Em ambos os contextos, as meninas preferiram os equipamentos de balanço e caixa de areia, enquanto os meninos preferiram os equipamentos múltiplos (bombeiros e casa do Tarzan. Os equipamentos que obtiveram significativa ocupação foram aqueles que possibilitaram uma maior diversidade de brincadeiras (faz de conta. Concluímos que as características físicas dos espaços deram previsibilidade para algumas brincadeiras e continuidade a certos mecanismos biológicos, sociais e culturais experienciados pelos seus usuários

  3. Modelos de negócios para periódicos científicos eletrônicos de acesso aberto.

    OpenAIRE

    Katiúcia Araujo Gumeiro

    2011-01-01

    Trata-se de uma pesquisa que estuda o uso de modelos de negócios no contexto da publicação de periódicos científicos eletrônicos de acesso aberto, em que as diferenças disciplinares são consideradas, especificamente quanto às seguintes questões: velocidades de publicação exigidas, financiamentos e particularidades que envolvem a edição de um periódico científico. Tem como objetivo elaborar um modelo que permita identificar os elementos necessários para configurar um modelo de negócios adequad...

  4. Características de repositório educacional aberto para usuários de língua brasileira de sinais

    Directory of Open Access Journals (Sweden)

    Romario Antunes da Silva

    Full Text Available O objetivo desse artigo é identificar as características que um repositório educacional aberto deve apresentar para atender as necessidade de informação dos alunos surdos e ouvintes do curso Letras Libras na modalidade a distância da Universidade Federal de Santa Catarina. Os objetivos específicos foram: a descrever o perfil dos alunos surdos e ouvintes; b examinar o uso das tecnologias da informação por esses alunos; e c identificar os documentos que um repositório deve apresentar para atender as necessidades de informação desses alunos. A pesquisa é exploratória, descritiva e qualitativo-quantitativa, e a análise foi realizada com estatística descritiva e análise de conteúdo. Conclui-se que os alunos utilizam o e-mail, as listas de discussão, o Messenger, ferramentas para compartilhamento de vídeos e os sites para surdos. Os alunos consideram muito importantes os processadores de texto, Messenger, Movie Maker, Media Player e planilhas para cálculo. Os alunos surdos consideram como documentos mais relevantes as videoaulas, dicionários e apostilas, e os alunos ouvintes, as videoaulas, os livros e as apostilas. O tipo de conteúdo requisitado são notícias sobre surdos, língua brasileira de sinais, tradução, tecnologia, linguística, aprendizagem do português, interpretação médico-jurídica e cultura surda. Os suportes requisitados para acesso à informação são os dicionários, vídeos, livros digitais e artigos. Os alunos preferem acessar as informações no repositório por meio de língua de sinais, legendas e em português.

  5. Clonixinato de lisina injetável intravenoso para o tratamento agudo das enxaquecas: um estudo piloto aberto

    Directory of Open Access Journals (Sweden)

    KRYMCHANTOWSKI ABOUCH V.

    1999-01-01

    Full Text Available Alguns antinflamatórios não esteroidais (AINE orais são eficientes para o tratamento dos ataques de migrânea ou enxaqueca. A despeito de sua eficiência para o tratamento destas cefaléias e de outras dores, existem comercialmente poucos antinflamatórios não esteroidais disponíveis para administração parenteral. O clonixinato de lisina (CL é um AINE derivado do ácido nicotínico que foi comprovadamente eficiente em vários tipos de síndromes álgicas como cólica renal, dor de compressão nervosa, dores musculares e odontalgias. O objetivo deste estudo foi avaliar a eficácia do CL intravenoso (IV no tratamento de um episódio severo de migrânea. Estudamos prospectivamente 19 pacientes, 17 mulheres e 2 homens, com idades de 18 a 57 anos e diagnóstico de migrânea de acordo com os critérios da Sociedade Internacional de Cefaléias (SIC. Os pacientes foram orientados a dirigirem-se à clínica no momento que a dor se iniciasse e, uma vez atingida a intensidade severa, foi iniciada a infusão venosa de CL e salina, em uma veia superficial do antebraço. Avaliadas após 30, 60 e 90 minutos a intensidade da dor e a presença de efeitos colaterais, observamos que todos os 19 pacientes encontravam-se sem dor após 90 minutos. Alguns pacientes apresentaram efeitos adversos leves e não houve alterações significativas nos sinais vitais. Concluímos que o AINE clonixinato de lisina (2-(3-cloro-o-toluidinopiridino-3-carboxilato de lisina IV, derivado do ácido nicotínico, com estrutura química semelhante à do ácido flufenâmico, foi eficiente em abolir um ataque de intensidade severa de migrânea em 90 minutos em 19 pacientes. Estudos controlados com metodologia duplo-cega e randomizada, assim como maior número de pacientes e ataques tratados, são necessários para confirmar estas observações iniciais.

  6. Conteúdos abertos e compartilhados: novas perspectivas para a educação Open and shared contents: new perspectives for education

    Directory of Open Access Journals (Sweden)

    Osmar Mantovani

    2006-04-01

    Full Text Available Mudanças em curso no cenário de produção e divulgação de conhecimentos bem como algumas questões importantes indutoras de tais mudanças são apontadas. A principal é o desbalanceamento, cada vez maior, entre os interesses da indústria cultural e os da sociedade, em favor da primeira, provocado, em anos recentes, por mudanças sucessivas no direito de propriedade intelectual por pressão da mesma indústria cultural que tem, hoje, o seu modelo de negócio ameaçado por práticas apoiadas por novas tecnologias de informação e comunicação e, especificamente, pela Internet. Tal desbalanceamento cerceia, em particular, a escola na escolha dos recursos mais apropriados para a educação de seus alunos. Um contramovimento promove "conteúdos abertos". Um ambiente que foi desenhado para apoiar a comunidade escolar na publicação e no compartilhamento de conteúdos para, dessa forma, ajudá-la a promover uma educação com parâmetros mais democráticos e adequados às transformações em curso é apresentado.Ongoing changes in the scenario of knowledge production and dissemination as well as some of the important issues that induced them are pointed out. The main one is an increasing shift of balance from the interests of society to those of the culture industry promoted, these last years, by successive amendments to the intellectual property rights. These were passed under the pressures of that industry whose business model is nowadays threatened by the practices supported by the new information and communication technologies and the Internet in particular. Such shift of balance specifically limits schools in their choices of the most appropriate resources to educate their students. A counter-movement is promoting "open contents" through an environment, presented here, designed to support the school community in publishing and sharing tasks. It is aimed at helping that community promote an education with more democratic and better

  7. Construção de um catálogo de aglomerados abertos para estudo da dinâmica da estrutura espiral da Galáxia

    Science.gov (United States)

    Carlos, I. M.; Lépine, J. R. D.

    2003-08-01

    Os aglomerados abertos são objetos de grande valor para o estudo da dinâmica da Galáxia devido esses objetos terem uma faixa de idade relativamente ampla. O trabalho visa estudar a dinâmica da estrutura espiral da Galáxia principalmente através do uso desses aglomerados, uma vez que o estudo da cinemática desses objetos é fundamental para esse objetivo. Nosso grupo trabalha no sentido de construir uma base de dados de aglomerados abertos contendo coordenadas, distância, idade, movimentos próprios e velocidades radiais e já disponibiliza uma nova versão do catálogo de aglomerados abertos o qual é uma compilação de edições anteriores, principalmente Lynga (1987), Mermilliod (1995) e ESO-B (Lauberts 1982). Nossa amostra possui cerca de 1630 aglomerados, mas nem todos os parâmetros acima citados foram determinados em sua totalidade. Para determinarmos esses parâmetros, derivamos as cores intrínsecas das estrelas membro de cada aglomerado a partir de seus tipos espectrais (busca feita no SIMBAD) obtendo assim o excesso de cor individual. A distribuição dos excessos de cor foi então utilizada para derivarmos o avermelhamento médio para cada aglomerado. De maneira similar, os tipos espectrais foram usados para estimar as magnitudes absolutas, e com as magnitudes absolutas e aparentes determinamos a respectiva distribuição do módulo de distância e finalmente a distância. Para determinar as idades foram confeccionados os diagramas cor-magnitude das estrelas de cada aglomerado onde foram superpostas a Seqüência Principal de Idade Zero (ZAMS). Superpomos a ZAMS de Schmidt-Kaler e isócronas de composição solar. Essas isócronas foram usadas para determinação das idades dos aglomerados. Uma vez que não temos ainda resultados finais, apresentamos então alguns diagramas cor-magnitude os quais foram usados para determinação, principalmente, da distância e idade dos aglomerados.

  8. POTENCIAL DOS RECURSOS EDUCACIONAIS ABERTOS PARA INTEGRAÇÃO DAS TECNOLOGIAS E CONVERGÊNCIA ENTRE AS MODALIDADES NA UFSM. POTENTIAL OF OPEN EDUCATIONAL RESOURCES FOR TECHNOLOGY INTEGRATION AND CONVERGENCE BETWEEN THE MODALITIES AT UFSM

    Directory of Open Access Journals (Sweden)

    Elena Maria Mallmann

    2013-11-01

    Full Text Available O foco de análise é a implementação e o fomento de práticas escolares, para potencializar a integração das tecnologias e a convergência entre as modalidades na Universidade Federal de Santa Maria (UFSM, Brasil, por meio de Recursos Educacionais Abertos. Objetivamos sistematizar princípios conceituais e práticas que balizam a utilização de recursos educacionais abertos, com vistas a maximizar diálogo e produção curricular mediados por tecnologias. Os procedimentos metodológicos de pesquisa-ação (planejamento participativo, observação e questionários survey geraram dados para análise referente à programação e à problematização de Recursos Educacionais Abertos, em cursos de graduação e pós-graduação mediados pelo Moodle institucional. Os resultados de acoplamento da pesquisa à ação didático-metodológica inovadora na UFSM evidenciam crescimento exponencial na programação semanal de recursos e atividades de estudo no Moodle. A afirmação conclusiva destaca que a disponibilização e o suporte técnico institucional de tecnologias em rede ampliam condições para integração e convergência entre as modalidades, especialmente no âmbito dos recursos educacionais abertos como hipertextos programados em html. The analysis focus is the implementation and the fomentation of school practices in order to enhance the technology integration and the convergence between the modalities at the Federal University of Santa Maria (UFSM, Brazil, through open educational resources. We aimed to systematize conceptual principles and practices that beacon the use of open educational resources, aspiring to maximize dialogue and curricular production mediated by technologies. The action research methodological procedures (participatory planning, observation and survey questionnaires generated analysis data relative to the programming and problematization of open educational resources, in undergraduate and graduate courses mediated

  9. Mold

    Centers for Disease Control (CDC) Podcasts

    2011-05-02

    This podcast answers a listener's question about the risks associated with mold after a natural disaster or severe weather.  Created: 5/2/2011 by National Center for Environmental Health (NCEH).   Date Released: 5/2/2011.

  10. Software para o encaixe de moldes com formato irregular em tecidos listrados

    Directory of Open Access Journals (Sweden)

    Andressa Schneider Alves

    2015-12-01

    Full Text Available Este artigo propõe uma solução para o problema do encaixe de moldes em tecidos listrados da indústria do vestuário. Os moldes são peças com formato irregular que devem ser dispostos sobre a matéria-prima, neste caso o tecido, para a etapa posterior de corte. No problema específico do encaixe em tecidos listrados, o local em que os moldes são posicionados no tecido deve garantir que, após a confecção da peça, as listras apresentem continuidade. Com base na pesquisa bibliográfica desenvolvida, foi proposto um algoritmo para lidar com o problema de encaixe de moldes em tecidos listrados: algoritmo de encaixe com pré-processamento implementado no software Riscare Listrado. Para testar o desempenho do algoritmo foram utilizados seis problemas benchmarks da literatura e proposto um novo problema denominado de camisa masculina. Os problemas benchmarks da literatura foram propostos para matéria-prima lisa e o problema camisa masculina especificamente para tecidos listrados. Quando comparado aos melhores resultados publicados na literatura para matéria-prima lisa, o algoritmo proposto obteve encaixes com eficiências inferiores. Porém, dos sete problemas testados em tecidos listrados, seis apresentaram resultados superiores ao recomendado pela literatura específica da área de moda para tecidos estampados.

  11. O museu aberto e comunicativo : fundamentação e proposta para estudos de públicos à luz de um enfoque info-comunicacional

    OpenAIRE

    Beites, Alexandre Manuel Rodrigues

    2011-01-01

    Os estudos de públicos aplicados ao universo museológico sofreram uma evolução que transitou sem grande efectividade ate um momento - o actual, em que lhes são exigidos resultados uteis. Vive-se uma "encruzilhada" metodológica para a qual esta dissertação pretende contribuir com uma proposta. Apostar no registo e tratamento dos dados info-comunicacionais do visitante como matéria-prima será o ponto de partida para uma estratégia, que se quer qualitativa, integradora de varias disciplinas e co...

  12. Sistema aberto ou fechado de nutrição enteral para adultos críticos: há diferença? Open versus closed enteral nutrition systems for critically ill adults: is there a difference?

    Directory of Open Access Journals (Sweden)

    Stella Marys Rigatti Silva

    2012-04-01

    Full Text Available OBJETIVO: Comparar o volume, calorias totais e proteínas recebidos pelos pacientes críticos quando utilizada nutrição enteral (NE por sistema aberto (SA e sistema fechado (SF; identificar os principais motivos para interrupção da NE. MÉTODOS: Estudo de coorte em que foram acompanhados adultos internados no Centro de Terapia Intensiva (CTI em dois períodos: em novembro de 2009, quando se adotava SA de NE para a totalidade dos pacientes (n = 85; e entre outubro de 2010 e abril de 2011, quando foi utilizado SF de NE (n = 170. Foram utilizados testes paramétricos e não paramétricos para comparação das variáveis respeitando-se sua distribuição. RESULTADOS: Os grupos assemelharam-se quanto às características clínicas e demográficas. Diferenças de mínima magnitude matemática e de nenhuma relevância clínica foram observadas entre os grupos: mais calorias/quilo foram prescritas ao grupo SA (p OBJECTIVE: To compare the volume, total calories, and protein received by critically ill patients between open and closed enteral nutrition (EN systems and identify the main reasons for EN discontinuation. METHODS: A cohort study in which adult patients admitted to the intensive care unit (ICU were followed-up in two periods: throughout November 2009 with all patients (n = 85 receiving EN using the open system (OS group; and from October 2010 to April 2011 with patients (n = 170 receiving EN using the closed system (CS group. Parametric and nonparametric tests were used to compare the variables, taking into account their distribution. RESULTS: Demographic and clinical characteristics were similar in both groups. There were minor differences with no statistical significance between groups: more calories/kg were prescribed to the OS group (p < 0.001, and a higher volume (mL/kg, p = 0.002 and protein (g/kg, p = 0.001 were prescribed to the CS group. Fasting, enteral feeding or gastrointestinal problems, and performance of procedures and ICU

  13. O uso de recursos educativos abertos (rea: benefícios para alunos e professores. O repositório de acesso aberto de Portugal │ Use of open educational resources (oer: benefits for students and teachers. The Portuguese open access repository

    Directory of Open Access Journals (Sweden)

    Maria Teresa Ferreira Costa

    2012-12-01

    Full Text Available Resumo Os Recursos Educativos Abertos (REA têm sido utilizados um pouco por todo o mundo, por Instituições de Ensino Superior, no sentido de abrir o conhecimento a todos que dele necessitam e, muitas vezes, desenvolvendo-se num objectivo de nivelador social. A sua produção assume-se como um procedimento normal por parte dos docentes visando envolver também os alunos, de forma a transformar uma determinada realidade do processo de ensino-aprendizagem numa outra com o objectivo da inclusão. A utilização de materiais pedagógicos digitais livres fornece ao professor a possibilidade de adaptação desses objetos aos mais diversos contextos de aprendizagem conforme os níveis, estilos e necessidades específicas dos alunos. A adopção dos REA, intimamente associada e decorrente do Movimento do Acesso Aberto (AA, no processo de ensino-aprendizagem permite estabelecer uma metodologia diferente, inovadora e tecnologicamente atual, potenciadora do uso das novas tecnologias de informação e comunicação (TIC. Palavras-chave Acesso Aberto, Recursos Educativos Abertos, Processo de Ensino-Aprendizagem, Portugal Abstract Open Educational Resources (OER have been used all over the world by Universities with the purpose of sharing knowledge with those who seek it, and often developing as an objective for social issues. Its production is becoming a common procedure by teachers, in a way to both involve students and to transform a certain reality of the teaching-learning process into a more inclusive one. The use of free digital pedagogical material gives the teacher the possibility of adapting those objects to the many different contexts of the learning process, according to the students’ level, styles and specific needs. The choice for the use of OER, closely associated to the Open Access Movement (OAM, allows establishing an innovative methodology in the teaching-learning process, a technological solution that potentiates the use of the new

  14. Equipamiento y metodología para la determinación de la vida de materiales para moldes

    Directory of Open Access Journals (Sweden)

    Plaza, L. M.

    2010-12-01

    Full Text Available Dies used in the non ferrous die casting process, have a limited service life due to the damage effect by surface cracking appearance. These cracks are mainly produced by thermal fatigue, which are promoted by a repeated heating and cooling process through working cycles. The existing demand to improve materials to extend the die’s service life leads to the development of new equipments to test the material behaviour. INASMET-TECNALIA in collaboration with FEAF (Spanish Federation of the Foundry Associations, has developed a testing machine to evaluate the thermal fatigue behaviour of steels used to manufacture dies. This testing machine is able to test forty samples simultaneously, getting a remarkable advantage in regard to previous developed test equipment. The versatility of heating and cooling system makes possible to test all kind of materials in very different thermal fatigue conditions.

    Los moldes empleados en la fundición inyectada de metales no férreos tienen una vida útil limitada, debido al deterioro del molde, que se manifiesta en forma de grietas superficiales. Dichas grietas son causadas, fundamentalmente, por el fenómeno de fatiga térmica, debido a los sucesivos ciclos de calentamiento-enfriamiento de la superficie del molde durante su trabajo. La exigencia de mejorar los materiales para alargar la vida de los moldes, hace necesario el desarrollo de nuevos equipamientos para evaluar su comportamiento durante los ciclos de trabajo. INASMETTECNALIA, en colaboración con la FEAF (Federación Española de Asociaciones de Fundidores, ha desarrollado una máquina para determinar el comportamiento de los aceros empleados para la fabricación de moldes frente al fenómeno de la fatiga térmica. La máquina de ensayos es capaz de ensayar cuarenta probetas simultáneamente, constituyendo una gran ventaja respecto a las máquinas desarrolladas anteriormente. Su versatilidad, en cuanto a los sistemas de calentamiento y

  15. Diseño de moldes para soldadura robotizada en el armado de dovelas

    OpenAIRE

    García Huerta, Víctor

    2011-01-01

    El Proyecto Final de Carrera “Diseño de moldes para soldadura robotizada en el armado de dovelas” se desarrolla en la sección de I+D de la empresa “Ferrobérica S.L.”, firma líder en el sector, con sede en la provincia de Barcelona. El proyecto consiste en la caracterización de un sistema que permita la automatización del proceso de producción del armado metálico para piezas de hormigón como las utilizadas en el reforzamiento de túneles. El trabajo se centra, para su cuantificac...

  16. Do Universo Privado ao Espaço Aberto, do Espaço Aberto ao Universo Privado - Recepção e Gênese de L´Étranger de Albert Camus

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    Samara Geske

    2009-10-01

    Full Text Available Este artigo pretende traçar linhas gerais sobre a recepção e a gênese de L’Étranger , passando pelo universo privado dos primeiros leitores do manuscrito até chegar ao espaço aberto de seus primeiros críticos, para do espaço aberto da obra publicada retornar o universo privado do processo de criação do romance.

  17. Revisión de las investigaciones con base en el estudio de las pinturas para moldes en la industria de la fundición

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    Álvaro Morales

    2011-11-01

    Full Text Available Las pinturas para moldes son sustancias de muy diversa naturaleza, utilizadas para recubrir las superficies de los moldes que estarán en íntimo contacto con el metal fundido y que buscan la sanidad completa de la pieza. La presente revisión hace énfasis en el papel que tiene la pintura como regulador térmico en los moldes metálicos y describe los parámetros que deben tenerse en cuenta para la correcta caracterización.

  18. CNPq e o acesso aberto à informação científica

    Directory of Open Access Journals (Sweden)

    José Donizetti Freire

    2015-09-01

    Full Text Available Nesta tese se discute o processo formal de comunicação científica por meio de artigos publicados em revistas científicas nacionais e internacionais e a acessibilidade dessas informações em canais de acesso aberto. Descrevem-se os modelos de negócios das editoras científicas e elabora-se uma proposta de sistema de gestão da produção científica financiada pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq em repositório digital de acesso aberto. A pesquisa envolveu várias fontes de informação incluindo um levantamento (survey na comunidade de pesquisadores-bolsistas de produtividade em pesquisa do CNPq, visando conhecer: as razões para publicar artigo científico; o nível de conscientização sobre acesso aberto à informação cientifica; e, a motivação para adotar os canais de acesso aberto para disseminação da produção científica. O trabalho é de natureza quali-quantitativa tendo como referência as técnicas do Discurso do Sujeito Coletivo (DSC na análise qualitativa dos dados. Os resultados revelaram que embora a maioria (66% dos pesquisadores do CNPq tenha conhecimento dos movimentos do acesso aberto à informação científica, desconhecem seus desdobramentos e avanços a ele associados. Sugere-se que esse desconhecimento deve-se à falta de políticas de informação em ciência e tecnologia no Brasil e de ações proativas das instituições de ensino e pesquisa e de agências de fomento à pesquisa para despertar e encorajar seus pesquisadores para o novo paradigma de comunicação universal da informação científica em ambientes digitais de acesso aberto na Internet.

  19. Moldes de arcilla para fundir metales procedentes del Castro Hallstáttico de El Royo (Soria

    Directory of Open Access Journals (Sweden)

    Jorge Juan EIROA

    2009-12-01

    Full Text Available Durante los trabajos de la segunda campaña de excavaciones arqueológicas en el castro de la Virgen del Castillo de El Royo (Soria, que se desarrollaron durante el verano de 1979, apareció un lote de moldes de arcilla para fundir metales que, por su indudable interés para documentar aún más el desarrollo de la metalurgia en la Meseta, ofrecemos hoy, independientemente de la memoria oficial que sobre el yacimiento y su excavación preparamos.

  20. DESENVOLVIMENTO DE UM PROGRAMA ABERTO DE ENSINO DE SISTEMAS DE CONTROLE

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    Ricardo Andrade Cava

    2010-01-01

    Full Text Available Este artigo apresenta os resultados produzidos no desenvolvimento de um Programa Aberto de Ensino de Sistemas de Controle (PAESC a ser utilizado como ferramenta auxiliar nas atividades de ensino da disciplina de Sistemas de Controle. Essa disciplina é parte integrante de vários currículos em cursos de engenharia e possui uma característica multidisciplinar, envolvendo, dentre outros, conteúdos de Cálculo, Física, Circuitos Elétricos, Mecanismos, dificultando o aprendizado dos alunos. Com o objetivo primordial de suprir essa dificuldade, o Programa Aberto de Ensino de Sistemas de Controle está sendo desenvolvido no sentido de proporcionar uma ferramenta tecnológica, disponível pela Web, para auxiliar o aprendizado dos futuros engenheiros. Para tanto, apresenta gráficos, animações e permite a interação. A ferramenta está sendo construída em linguagem Java, e os códigos produzidos são abertos, de modo a permitir que possam ser enviadas contribuições às simulações desenvolvidas.

  1. A indústria de publicação contra o acesso aberto

    Directory of Open Access Journals (Sweden)

    Kenneth Rochel de Camargo Jr

    2012-12-01

    Full Text Available A publicação em revistas de acesso aberto cresceu expressivamente nos últimos anos. As publicações de acesso fechado, por sua vez, têm custo de acesso cada vez mais elevado, por se beneficiarem de um modelo econômico peculiar: o trabalho relevante e os insumos essenciais são entregues gratuitamente a fornecedores que contam com um mercado cativo, praticamente sem concorrência. O mercado editorial é altamente oligopolizado, característico de indústrias que trabalham com o regime de copyright. Isso contribui para a elevação dos preços de seus produtos. Políticas mandatórias de acesso aberto, como a determinada pela agência National Institutes of Health, constituem-se em ameaça a esse modelo de negócios e são enfrentadas pela indústria em várias frentes, incluindo a passagem de legislação para sabotar tais iniciativas. O objetivo deste comentário foi apresentar alguns aspectos principais desse enfrentamento e sugerir possíveis estratégias de incremento da publicação de acesso aberto em nosso meio.

  2. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    Science.gov (United States)

    Martinez Mateo, Isidoro Jose

    Mould materials for injection moulding of polymers and polymer-matrix composites represent a relevant industrial economic sector due to the large quantity of pieces and components processed. The material selection for mould manufacturing, its composition and heat treatment, the hardening procedures and machining and finishing processes determine the service performance and life of the mould. In the first part of the present study, the relationship between the hardness and microstructure and the wear resistance of mould steels from large blocks has been studied by pin-on-disc tests, studying the main wear mechanisms. In order to determine the surface damage on mould steels under real injection conditions, different commercial steels have been studied by measuring the variation of surface roughness with the number of injected pieces with different reinforcement percentages and different mould geometries, by using optical profilometry and scanning electron microscopy techniques. It was important to determine the variation of surface roughness of the moulded pieces with the number of injection operations. The materials used were polybutyleneterephthalate pure and reinforced with either 20% or 50% glass fibre. For the different mould designs, the evolution of the glass fibre orientation with injection flow has been determined by image analysis and related to roughness changes and surface damage, both of the composite parts and of the mould steel surface. Finally, the abrasion resistance of the composite parts has been studied by scratch tests as a function of the number of injected parts and of the scratch direction with respect to injection flow and glass fibre orientation. Los materiales para moldes de inyeccion de polimeros y materiales compuestos representan un sector economicamente muy relevante debido al gran aumento del numero de componentes fabricados a partir de materiales polimericos obtenidos mediante moldeo por inyeccion. La seleccion del material para la

  3. Molde de látex natural (Hevea brasiliensis) para neovaginoplastia

    OpenAIRE

    2008-01-01

    OBJETIVO: avaliar a utilização do molde de látex natural (Hevea brasiliensis) como modificação à neovaginoplastia de McIndoe e Bannister em pacientes portadoras da síndrome de Mayer-Rokitansky-Küster-Hauser (MRKH). MÉTODOS: análise retrospectiva de nove pacientes com o diagnóstico de síndrome de MRKH, submetidas à neovaginoplastia pela técnica de McIndoe e Bannister com molde de látex natural. Foram avaliadas epitelização, amplitude e profundidade das neovaginas, ocorrência de coitos bem como...

  4. Espectroscopia de candidatos a remanescentes de aglomerados abertos

    Science.gov (United States)

    Pavani, D. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2003-08-01

    A pesquisa sobre remanescentes de aglomerados abertos tem despertado grande interesse. Seguindo esta tendência encontramos estudos teóricos e observacionais. Os primeiros baseiam-se em simulações numéricas buscando determinar fração de binárias e distâncias galatocêntricas, tempo de vida e conteúdo estelar. Estes estão relacionados à função inicial de massa e densidade de estrelas, ou seja, se ricos ou pobremente povoados, compactos ou esparsos. No caso observacional procuram-se identificar os remanescentes considerando-se que trazem estas assinaturas de seus percursores. No presente estudo empregamos espectroscopia para analisar oito concentrações pobremente povoadas, previamente classificadas como aglomerados abertos, sendo sete compactas e uma esparsa. As observações foram obtidas através do telescópio de 2,15 m do CASLEO em San Juan, Argentina, em turnos entre 2001 e 2003. Utilizamos uma câmara CCD contendo um chip Tektronics de 1024X1024 pixeis aliado a um espectrógrafo REOSC. O domínio espectral vai de 3700 a 7000 Å. As reduções foram realizadas no Observatório Astronômico de Córdoba (Argentina) usando pacotes IRAF padrões. Determinamos idades, avermelhamentos e tipos espectrais através de comparações com biblioteca de estrelas e de aglomerados. Em alguns casos nossos espectros estavam dominados por estrelas individuais às quais determinamos seus tipos espectrais. Aos oito objetos adicionamos mais cinco da literatura recente analisados via espectro ou diagrama cor-magnitude. O histograma resultante contém idades típicas entre 0.5 e 3 Ganos. Considerando que predominantemente estes objetos encontram-se na vizinhança solar e, portanto, não cruzaram muitas vezes o plano Galático esperamos que a diferença no tempo necessário para dissolução destes prováveis remanescentes seja em função de diferentes massas iniciais.

  5. Diseño de moldes y tecnología para la fabricación de engranajes plásticos de dientes rectos asimétricos. // Diseño de moldes y tecnología para la fabricación de engranajes plásticos de dientes rectos asimétricos.

    Directory of Open Access Journals (Sweden)

    A. R. García Martínez

    2008-05-01

    Full Text Available En el presente trabajo se hace un análisis de los procesos de moldeado por inyección de los engranajes, mostrándose las ventajas conrespecto al maquinado de los polímeros. Se brinda el procedimiento de cálculo para el diseño y fabricación de ruedas dentadas condientes rectos asimétricos, así como los métodos de obtención del herramental necesario que permite acabados de alta calidad en piezasfabricadas de materiales termoplásticos. Se usa una metodología de cálculo que incluye diferentes parámetros de un molde, tales como:número de cavidades, tiempo de enfriamiento, longitud de las vías de frío. Por otra parte se sugiere la configuración de los canales dealimentación y puntos de inyección entre otras. Finalmente se muestra el molde diseñado y fabricado para un caso particulardestacando la validez del método usado. Se resalta en particular la asimetría en los perfiles logrados mediante la utilización del métodode la electro erosión por hilo para fabricar la cavidad del molde.Palabras claves: moldes, engranajes asimétricos, electroerosivo._____________________________________________________________________________Abstract.An analysis of the injection molding process of plastic gears, showing its advantages regarding width machining process itis made in this paper. Calculation procedure for designing and molding of spur gears with asymmetric teeth is offer,including necessary tools for obtaining high quality surface finishing of gears made from thermoplastic materials. Theprocedure includes different molding parameters such as number of cavities, cooling time, injection points, etc. Moldedspur gears, tools, machines and molds are showed.Key words: molds, gears, EDM.

  6. EFECTO DEL MAQUINADO EN DURO EN LA REDUCCIÓN DEL TIEMPO DE FABRICACIÓN DE CAVIDADES PARA MOLDES

    Directory of Open Access Journals (Sweden)

    JOSÉ MANUEL ARROYO OSORIO

    2012-01-01

    Full Text Available La tecnología de maquinado a alta velocidad (High Speed Machining o HSM ha permitido el maquinado de aceros en estado endurecido. En este trabajo se comparó experimentalmente el tiempo fabricación de una cavidad de molde de pequeñas dimensiones utilizando la secuencia de procesos convencional que incluye electroerosión y utilizando una secuencia en que se realiza el proceso de fresado en duro con estrategias HSM tanto para desbaste como para acabado. El uso de la secuencia de procesos con maquinado HSM en duro resultó en una reducción de 55% en el tiempo de manufactura comparado con el proceso tradicional usando electroerosión. Sin embargo, es importante anotar que en aplicaciones específicas debe realizarse un análisis de la secuencia de procesos adecuada para cada caso particular considerando los costos y beneficios pues no hay una secuencia que sea mejor en todos los casos.

  7. Grupo de apoio aberto para pessoas portadoras do HIV: a construção da homogeneidade Open support groups for persons living with HIV/AIDS: the construction of its homogeneity

    Directory of Open Access Journals (Sweden)

    Emerson F. Rasera

    2003-04-01

    Full Text Available Há um debate na literatura a respeito da homogeneidade na composição dos grupos para portadores do HIV, segundo estágios da doença, formas de infecção e sexo dos participantes. Este estudo, baseado em uma concepção construcionista da terapia e da produção do conhecimento, buscou analisar como os sentidos sobre a soropositividade e o apoio eram negociados em uma sessão de um grupo de apoio voltado a esta população. Observamos que a homogeneidade e o apoio, antes de serem categorias a priori usadas para organizar o grupo, são ativamente construídas na e através da situação grupal por seus participantes. Implicações éticas e metodológicas decorrentes dessa análise apontam para o reconhecimento das condições sócio-históricas de construção dos sentidos da soropositividade e da hegemonia de algumas de suas descrições.There is a debate in the literature regarding the homogeneity in the composition of the groups for persons with HIV/AIDS, according to stages of the disease, infection forms, and the participants' sex. This study, based on a constructionist conception of the therapy and of the production of the knowledge, sought analyzing how the senses on the seropositivity and the support were negotiated in a session of a support group oriented to this population. We observed that the homogeneity and the support, before being a priori categories used to organize the group, are actively built in and through the group setting by its participants. Ethical and methodological implications of this analysis point to the recognition of the social-historical conditions for the construction of the senses of the seropositivity and of the hegemony of some of its descriptions.

  8. Caracterización del aluminio para la fabricación de insertos de moldes de inyección de plásticos.

    Directory of Open Access Journals (Sweden)

    H. González Zulueta

    2008-09-01

    Full Text Available Se describe una investigación experimental realizada para estudiar el comportamiento en condiciones reales de insertos para cavidades fabricados con dos aleaciones de aluminio diferentes. Se fabricaron 1000 piezas (probetas para ensayo de plásticos de polipropileno, empleando un molde de diseño normalizado con insertos para la cavidad correspondiente, fabricados con cada una de las aleaciones a ensayar. Cada 250 piezas producidas, tanto las cavidades como la pieza elaborada fueron medidas en zonas previamente seleccionadas y estos resultados se emplearon para caracterizar el comportamiento de las aleaciones ensayadas. Las condiciones de presión y temperatura del proceso de inyección se seleccionaron atendiendo a los requerimientos industriales que corresponden al plástico utilizado.The behaviour of cavities in molds for plastic injection, manufactured with two different aluminium alloys under real conditions is described by experimental investigation. 1000 pieces (probes for testing mechanical properties of plastics were produced from polypropylene, using a normalized designed mold with specially manufactured cavities and the two tested alloys. For the produced pieces, the dimension (width of the cavities and the elaborated pieces were measured in previously selected areas, these results were used to characterize the behaviour of the tested alloys. The conditions of pressure and temperature for the injection process were selected according to the industrial requirements for the plastic used in the investigation.

  9. Jovem aprisionado em regime semi-aberto: um estudo transdisciplinar

    OpenAIRE

    Lazzaron, Leandra Regina

    2008-01-01

    A presente dissertação, vinculada à linha de pesquisa “Criminologia e Controle Social”, do Programa de Pós-Graduação em Ciências Criminais, da Faculdade de Direito da Pontifícia Universidade Católica do Rio Grande do Sul, identifica o perfil do jovem apenado, aprisionado em regime semi-aberto, no Instituto Penal de Viamão, com base na escala PCL-R. O estudo de campo foi realizado na instituição prisional e avaliou 40 jovens, com idade de 18 a 23 anos, que cumprem pena em regime semi-aberto. O...

  10. Método para la replicación, amplificación o secuenciación de un ADN molde

    OpenAIRE

    2009-01-01

    Método para la replicación, amplificación o secuenciación de un ADN molde. La presente invención se encuadra dentro del campo de la biotecnología. Específicamente, se refiere a un método para llevar a cabo la replicación, la amplificación o la secuenciación de un ácido desoxirribonucleico con una ADN polimerasa del tipo 29 y a un kit para llevar a cabo dicho método.

  11. Competitividade e potencial de crescimento do cluster de produtores de moldes para a indústria do plástico de Joinville

    Directory of Open Access Journals (Sweden)

    Marco Flávio da Cunha Resende

    2009-06-01

    Full Text Available As empresas aglomeradas geograficamente, principalmente de pequeno/médio portes, vêm apresentando recentemente êxito no que se refere à competitividade, à geração de empregos, etc. O caso com maior número de referências na literatura internacional são os distritos industriais italianos, destacando-se pela elevada inserção internacional. Em Joinville, encontra-se um significativo aglomerado geográfico de empresas produtoras de moldes para a indústria do plástico. Quando a aglomeração geográfica de empresas se transforma em um cluster de empresas, seu potencial de crescimento e sua competitividade são alavancados. Este trabalho investigou se a aglomeração geográfica de empresas de moldes em Joinville corresponde a um cluster, e, em caso afirmativo, buscou identificar o potencial de seu crescimento e de sua competitividade. Constatou-se que há em Joinville um cluster de produtores de moldes em pleno desenvolvimento, que cresce e prospera com base na intensificação das redes de cooperação na região. Todavia, ele está aquém do desenvolvimento alcançado pelos clusters dos principais centros mundiais produtores de moldes para a transformação do plástico.

  12. Mold Allergy

    Science.gov (United States)

    ... Ask the Allergist Health Professionals Partners Media Donate Allergies Mold Allergy What Is a Mold Allergy? If you have an allergy that occurs over ... basement. What Are the Symptoms of a Mold Allergy? The symptoms of mold allergy are very similar ...

  13. HMS: UM SISTEMA ABERTO PARA AUTOMAÇÃO RESIDENCIAL

    Directory of Open Access Journals (Sweden)

    Paulo C.A. Feitosa Jr

    2010-12-01

    Full Text Available HMS (House Management System is a system for home automation, developed in JAVA platform, that permits you to control electronic devices using a local control unit or a remote control unit, that must be connected by Internet or wireless network. One of the main characteristics of this system is the easily insertion of diverse kind electronics devices without having to make changes in the structure of the system.

  14. El Moldeo en el Proceso de Inyección para el Logro de Objetivos Empresariales // The Molds in Injection Process for the Achievement of Business Objectives // O Molde no Processo de Injeção para Alcançar os Objetivos de Negócios

    Directory of Open Access Journals (Sweden)

    Julio César Acosta-Prado

    2017-01-01

    Full Text Available La inyección de plásticos es un proceso que se ha venido abriendo paso en la industria, debido a los beneficios técnicos y económicos obtenidos en referencia a otros procesos de transformación de materiales. Actualmente, piezas con requerimientos específicos han encontrado en este proceso la mejor solución, desplazando a materiales tradicionales (bronce, aluminio, fundición de hierro gris o de acero, etc. en aplicaciones industriales. El nivel de complejidad, la calidad de los materiales y el número de cavidades inciden en el costo del molde. Para poder establecer una relación adecuada entre costos de producción y el molde se deben definir bien, la figura a inyectar, el número de piezas y el costo del molde. Este artículo pretende realizar una aproximación de los cálculos teóricos y económicos aplicados al molde del proceso de inyección de plástico. Finalmente, se encontró que el molde, no solo presenta una fuerte incidencia con la rentabilidad del proceso, sino que de su adecuado diseño depende la posición competitiva de las fábricas de plásticos.

  15. Fluxes design for continuous casting mold of slab low carbon steels; Diseno de polvos de molde para colada continua de slabs de aceros bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Ramirez, A.; Chavez-Alcala, J. F.; Romero-Serrano, J. A.

    2004-07-01

    Commercial fluxes were characterized by laboratory tests, and their original properties were changed with additions of chemical reagents in order to establish criteria and design strategies to produce new fluxes. The characterization of the commercial fluxes reveals that they are produced by simple mechanical blend of minerals, using feldspars and clays as base materials, containing SiO{sub 2} Al{sub 2}O{sub 3}, Na{sub 2}O and in less quantity K{sub 2}O, Fe{sub 2}O{sub 3} and MnO; limestone as the main source of CaO, fluorspar (CaF{sub 2}) used to control the viscosity and graphite as carbon source. Melting-solidification tests revealed melting and fluidity temperatures and the existence of abundant mineralogical phases formed during the flux solidification. some important mineralogical compounds are the nepheline (NaAlSiO{sub 4}) and cus pidine (Ca{sub 4}Si{sub 2}O{sub 7}F{sub 2}): these species have a direct influence on the heat transfer phenomena from strand to mold and therefore on the phase transformations and the shrinkage of the steel. (Author) 8 refs.

  16. Study on the behaviour of fluxes to steel continuous casting mold; Estudio del comportamiento de los fundentes para molde de colada continua de acero

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, J.F.; Celaya, Arturo; Morales, Rodolfo D. [Instituto Politecnico Nacional, Mexico City (Mexico). Dept. de Ingenieria Metalurgica; Barron, Miguel A. [Universidad Nacional Autonoma de Mexico, Azcapotzalco (Mexico)

    1996-12-31

    A mathematical heat transfer model has been developed, which calculates both the field flow and the temperature profile through the flux thickness between the mold and the strand. The physical condition of the flux in each point is calculated as a function of the physical properties of the powder, the powder film thickness and the oscillation conditions. The model consists of two heat transfer submodels, one for the old and the other one for the steel strand. The dynamic of both system are used as boundary conditions for solving the heat transfer and the Navier-Stokes equations. The calculated dynamic behavior is mostly influenced by the flux properties. The thermophysical and rheological properties of the most employed fluxes by mexican steel plants were considered for carrying out the simulations. Some of these properties were determined by using standard experimental techniques. I has been found a possible non linear velocity profile, which were not prior reported, depending on the flux properties and the operation conditions. This effect has some influence on the shear stress acting on the strand surface due to the presence of the flux. (author) 14 refs., 10 figs., 2 tabs.

  17. Diseño de polvos de molde para colada continua de slabs de aceros bajo carbono

    Directory of Open Access Journals (Sweden)

    Cruz-Ramírez, A.

    2004-02-01

    Full Text Available Commercial fluxes were characterized by laboratory tests, and their original properties were changed with additions of chemical reagents in order to establish criteria and design strategies to produce new fluxes. The characterization of the commercial fluxes reveals that they are produced by simple mechanical blend of minerals, using feldspars and clays as base materials, containing SiO2, Al2O3, Na2 O and in less quantity K2O, MgO, Fe2 O3and MnO; limestone as the main source of CaO, fluorspar (CaF2 used to control the viscosity and graphite as carbon source. Melting-solidification tests revealed melting and fluidity temperatures and the existence of abundant mineralogical phases formed during the flux solidification. Some important mineralogical compounds are the nepheline (NaAlSiO4 and cuspidine (Ca4Si2O7F2; these species have a direct influence on the heat transfer phenomena from strand to mold and therefore on the phase transformations and the shrinkage of the steel.

    A partir de la caracterización de polvos comerciales mediante pruebas de laboratorio y la modificación de sus propiedades mediante adiciones de compuestos químicos, se identificaron y desarrollaron criterios y estrategias de diseño que sirvieron de base para elaborar nuevos polvos. La caracterización de los polvos comerciales indica que se fabrican por simple mezcla mecánica de minerales, utilizando feldespatos y arcillas como materiales base, que contienen SiO2, Al2O3, Na2 O y, en menor proporción, K 2O, MgO, Fe2 O3 y MnO, caliza como fuente principal de CaO, fluorita (CaF2 como fluidificante y grafito como fuente de carbono. Mediante pruebas de fusión-solidificación se determinaron las temperaturas de fusión y fluidez de los polvos y

  18. O espaço político aberto pela leitura literária

    Directory of Open Access Journals (Sweden)

    Leonardo Pinto de Almeida

    2013-01-01

    Full Text Available O presente artigo se propõe questionar sobre o espaço político aberto pela leitura literária. Especificando a literatura como uma tentativa de compreensão de problemas relacionados à existência, sublinhamos como a leitura literária coloca em questão nossas convicções e verdades defendidas cotidianamente. Para tanto, compreendemos as relações tecidas entre a linguagem, o poder e a resistência no seio da experiência literária. Concluímos que a leitura literária é atravessada por formas de resistência às palavras de ordem que circulam de forma hegemônica em nossa sociedade, disponibilizando assim uma transformação em nossa rede afetiva e cognitiva.

  19. Caracterización del aluminio para la fabricación de insertos de moldes de inyección de plásticos. // Aluminium alloys behaviour used in the manufacturing of cavities in molds for plastic injection process.

    Directory of Open Access Journals (Sweden)

    H. González Zulueta

    2008-09-01

    Full Text Available Se describe una investigación experimental realizada para estudiar el comportamiento en condiciones reales de insertospara cavidades fabricados con dos aleaciones de aluminio diferentes. Se fabricaron 1000 piezas (probetas para ensayo deplásticos de polipropileno, empleando un molde de diseño normalizado con insertos para la cavidad correspondiente,fabricados con cada una de las aleaciones a ensayar. Cada 250 piezas producidas, tanto las cavidades como la piezaelaborada fueron medidas en zonas previamente seleccionadas y estos resultados se emplearon para caracterizar elcomportamiento de las aleaciones ensayadas. Las condiciones de presión y temperatura del proceso de inyección seseleccionaron atendiendo a los requerimientos industriales que corresponden al plástico utilizado.Palabras claves: Moldes, cavidades, aluminio, experimento, inyección de plástico.__________________________________________________________________________Abstract:The behaviour of cavities in molds for plastic injection, manufactured with two different aluminium alloys under realconditions is described by experimental investigation. 1000 pieces (probes for testing mechanical properties of plastics wereproduced from polypropylene, using a normalized designed mold with specially manufactured cavities and the two testedalloys. For the produced pieces, the dimension (width of the cavities and the elaborated pieces were measured in previouslyselected areas, these results were used to characterize the behaviour of the tested alloys. The conditions of pressure andtemperature for the injection process were selected according to the industrial requirements for the plastic used in theinvestigation.Key words: Mold, cavity, aluminium, experiment.

  20. Diseño de moldes y tecnología para la fabricación de engranajes plásticos de dientes rectos asimétricos.

    Directory of Open Access Journals (Sweden)

    A. R. García Martínez

    2008-05-01

    Full Text Available En el presente trabajo se hace un análisis de los procesos de moldeado por inyección de los engranajes, mostrándose las ventajas con respecto al maquinado de los polímeros. Se brinda el procedimiento de cálculo para el diseño y fabricación de ruedas dentadas con dientes rectos asimétricos, así como los métodos de obtención del herramental necesario que permite acabados de alta calidad en piezas fabricadas de materiales termoplásticos. Se usa una metodología de cálculo que incluye diferentes parámetros de un molde, tales como: número de cavidades, tiempo de enfriamiento, longitud de las vías de frío. Por otra parte se sugiere la configuración de los canales de alimentación y puntos de inyección entre otras. Finalmente se muestra el molde diseñado y fabricado para un caso particular destacando la validez del método usado. Se resalta en particular la asimetría en los perfiles logrados mediante la utilización del método de electro-erosión por hilo para fabricar la cavidad del molde.An analysis of the injection molding process of plastic gears, showing its advantages regarding width machining process it is made in this paper. Calculation procedure for designing and molding of spur gears with asymmetric teeth is offer, including necessary tools for obtaining high quality surface finishing of gears made from thermoplastic materials. The procedure includes different molding parameters such as number of cavities, cooling time, injection points, etc. Molded spur gears, tools, machines and molds are showed.

  1. Determinação analítica da performance da irrigação por sulcos abertos e em declive

    Directory of Open Access Journals (Sweden)

    Aristides Fraga Lima Filho

    2015-06-01

    Full Text Available Uma solução analítica foi desenvolvida, para avaliar sulcos abertos e em declive, com base na teoria de Balanço de Volume de Walker e Skogerboe (1987. Essa metodologia é capaz de obter, matematicamente, a performance de um sistema, dispensando a construção de gráficos que definem os parâmetros de avaliação. A solução matemática é baseada no ajuste de equações ao modelo potencial, no cálculo das áreas sob as curvas definidas no ajuste e na intercessão de curvas, obtendo-se, assim, a performance de sistemas de irrigação por sulcos abertos e em declive. Para validação da metodologia, foi realizado um experimento de campo, na Fazenda Experimental da Universidade Federal do Ceará, situada no município de Pentecoste, pertencente ao Centro de Ciências Agrárias. Os dados de campo foram submetidos à análise pelas duas metodologias. Os resultados mostraram que a metodologia analítica pode ser usada para avaliar a irrigação por sulcos abertos e em declive.

  2. Allergies, asthma, and molds

    Science.gov (United States)

    Reactive airway - mold; Bronchial asthma - mold; Triggers - mold; Allergic rhinitis - pollen ... Things that make allergies or asthma worse are called triggers. Mold is a common trigger. When your asthma or allergies become worse due to mold, you are ...

  3. Litografia de nanoesferas para obtenção de moldes secundários poliméricos eletrodepositados em sílicio

    OpenAIRE

    Jasinski, Éverton Fabian

    2007-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2007 Este trabalho introduz uma nova técnica de nanoestruturação de materiais baseado em litografia de nanoesferas, que permite a eletrodeposição, em silício, de redes ordenadas de esferas, usando moldes secundários de polipirrol. Embora a viabilidade da técnica já tivesse sido demonstrada para uso em substratos metálicos, foi necess...

  4. Moldes de ABS construídos pelo processo de modelagem por fusão e deposição para injeção de PP e PEBD PP and LDPE injection in ABS molds built with fused deposition modeling

    Directory of Open Access Journals (Sweden)

    José A. Foggiatto

    2004-12-01

    Full Text Available Os processos de prototipagem rápida (Rapid Prototyping - RP e ferramental rápido (Rapid Tooling - RT surgiram para reduzir os tempos de desenvolvimento de produtos na fase de projeto diminuindo a necessidade de retrabalhos e, conseqüentemente, antecipando a entrada de novos produtos no mercado. Neste trabalho foi utilizada uma das tecnologias de prototipagem rápida, denominada Modelagem por Fusão e Deposição (FDM, na construção de moldes em ABS com o objetivo de investigar sua aplicação na moldagem por injeção de termoplásticos. Amostras das peças injetadas foram submetidas a ensaios de difração de raios X, dureza Shore D e tração. Os resultados mostraram a viabilidade de fabricar pequenos lotes de peças em PEBD e PP com propriedades mecânicas bastante similares às encontradas em peças moldadas em moldes metálicos.Rapid Prototyping and Rapid Tooling are aimed at reducing the development time of products in the design phase by minimizing re-workings and, consequently, reducing the time to launch new products. In this work one of the technologies of rapid prototyping, called Fused Deposition Modeling (FDM, was used in the construction of ABS molds with the objective of investigating its application in the injection molding of thermoplastics. Specimens of the molded parts were characterized with X-ray diffraction, Shore D hardness and tensile tests. The results demonstrated the viability to manufacture small batches of LDPE and PP parts with mechanical properties similar to those molded parts in metallic molds.

  5. Molds in the Environment

    Science.gov (United States)

    ... on Facebook Tweet Share Compartir Molds in the Environment What are molds? What are some of the ... molds found? Molds are found in virtually every environment and can be detected, both indoors and outdoors, ...

  6. Mold Testing or Sampling

    Science.gov (United States)

    In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building's compliance with federal mold standards.

  7. A Estrutura de Propriedade, Os Benefícios Privados de Controle e o Valor das Empresas de Capital Aberto no Brasil

    OpenAIRE

    Fernando Correia de Araújo Filho, Luiz

    2003-01-01

    A governança corporativa das empresas tem sido tema de vários trabalhos, nacionais e internacionais, e, considerado por instituições, como o Banco Mundial, questão fundamental para a viabilidade do crescimento econômico de países emergentes. Nesse sentido, essa dissertação investiga a estrutura de propriedade característica da empresa de capital aberto no Brasil, o potencial de apropriação de benefícios privados de controle e os custos de agência decorrentes das características observadas de ...

  8. Investimento e financiamento: um enfoque sobre empresas de capital aberto

    Directory of Open Access Journals (Sweden)

    Elton Eustáquio Casagrande

    2011-12-01

    Full Text Available O objetivo do artigo é analisar os determinantes do investimento para uma amostra com 334 empresas no Brasil para o período de 1998 a 2000. As empresas foram selecionadas segundo o critério de liquidez acionário através do índice de negociabilidade de 1998 da Bolsa de Valores de São Paulo, que aponta o grau de liquidez das ações. Com isso, procuramos contribuir para o entendimento do financiamento das empresas no Brasil em condições de instabilidade macroeconômica.

  9. Emprego de uma lama com caráter refratário para o processo de fundição odontológica Use of a refractory slurry characteristic in mold casting

    Directory of Open Access Journals (Sweden)

    Heitor PANZERI

    1998-07-01

    Full Text Available A utilização de novos materiais, especialmente aqueles metálicos, tem sido uma constante na odontologia. Graças às necessidades da indústria no desenvolvimento de produtos cada vez com maior resistência, principalmente à corrosão, a prótese tem-se beneficiado com um número elevado de ligas metálicas excelentes. Para atender a necessidade de conformar as ligas em restaurações ou aparelhos próprios à nossa profissão, devem ser desenvolvidos refratários para estas ligas. Este é o caso da proposta de usar uma lama refratária como molde para confecção da fundição. A lama proposta, além de servir aos propósitos, tem-se mostrado capaz de oferecer melhor acabamento da liga.The use of new materials, particularly metal alloys, has been a constant trend in Dentistry. The industrial need to develop products with greater resistance to corrosion has benefited prosthodontics with a large number of excellent metallic alloys. In order to adapt such alloys to dental restorations or devices, refractory materials ought to be developed. That is the aim of using slurry as a mold in the casting process, which also makes it possible to obtain surfaces with improved finish.

  10. Competitividade e potencial de crescimento do cluster de produtores de moldes para a indústria do plástico de Joinville

    Directory of Open Access Journals (Sweden)

    Marco Flávio da Cunha Resende

    2004-04-01

    Full Text Available The geographic concentration of firms has been successful recently in many ways: international competitiveness of these firms, regional income growth, etc. The Italian industrial districts are the case of highest relevance in international literature. In Joinville, there is a significant geographic concentration of mold manufacturers for the plastics industry. When a geographic concentration of firms is a cluster, the potential growth and competitiveness of the firms increase. This paper sought to determine whether this geographic concentration of firms was in effect a cluster, and to study its potential of growth and of competitiveness were this true. The finding was that the geographic concentration of mold producers in Joinville does represent a cluster and has significant growth potential. However, this cluster is less developed and less competitive when compared to the major mold producer clusters in the world.

  11. Julgamento de colinearidade e percepção de distância exocêntrica em campo aberto

    Directory of Open Access Journals (Sweden)

    Javier Enrique Santillán

    2011-01-01

    Full Text Available O propósito foi investigar experimentalmente o desempenho dos observadores numa original tarefa de julgamento de colinearidade em campo aberto (dimensões 20 x 30 m. Participaram do experimento 30 observadores. Os estímulos foram estacas verticais de alturas variáveis, quatro fixos e quatro móveis. A tarefa consistiu em ajustar os dois estímulos móveis (mediante controle à distância para que ficassem colineares aos dos estímulos fixos nos extremos de cada diagonal. Foi realizada uma análise de variância (ANOVA fatorial sobre os erros de colinearidade, revelando somente efeito significativo para o fator ‘Estímulo Móvel’ (F(3,473=69,86 p<0,001 notando-se uma sistemática na distribuição dos erros. As pequenas variações na distância exocêntrica percebida (com erros constantes dez vezes menores que os encontrados ao avaliar as distâncias egocêntricas e a relação dos erros cometidos com as distâncias egocêntricas indicariam que o marco de referência eliciado por esta tarefa de colinearidade, embora possa estar baseado nos indícios exocêntricos, é escalado por um fator egocêntrico.

  12. Análise eletromiográfica de músculos do membro inferior em exercícios proprioceptivos realizados com olhos abertos e fechados

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    Daniela Cristina Silveira de Oliveira

    2012-08-01

    Full Text Available INTRODUÇÃO: A propriocepção é um termo utilizado para descrever todas as informações neurais originadas nos proprioceptores das articulações, músculos, tendões, cápsulas e ligamentos, que são enviadas por meio das vias aferentes ao sistema nervoso central. A eletromiografia (EMG é o estudo da função muscular por meio da averiguação do sinal elétrico que emana do músculo, sendo também, o estudo da atividade da unidade motora. OBJETIVO: Realizar uma análise eletromiográfica dos músculos reto femoral (RF e tibial anterior (TA, em diferentes exercícios proprioceptivos (disco de Freeman-DIS e balancim-BAL com os olhos abertos (OA e fechados (OF. MÉTODOS: A análise foi realizada com 10 indivíduos do gênero masculino, fisicamente ativos, em um tempo de coleta de 10 segundos em cada aparelho tanto com olhos abertos como fechados. RESULTADOS: De acordo com nossos achados, observamos uma diferença significativa quando os exercícios proprioceptivos são realizados com olhos abertos e olhos fechados, obtendo uma ativação muscular maior, de acordo com a análise eletromiográfica, nos exercícios com olhos fechados, ressaltando a importância do sistema visual e como ele interfere na posição do corpo quando este é submetido a variações de equilíbrio causadas pelos aparelhos pesquisados. CONCLUSÃO: Concluímos que o músculo reto femoral não apresentou diferenças significativas evidentes entre os aparelhos balancim e disco de Freeman, assim como quando o exercício era realizado com os olhos abertos ou fechados. A diferença significativa ocorrida foi entre o balancim OA e OF e entre balancim OA e disco de Freeman OF. Já o músculo tibial anterior, apresentou diferenças significativas maiores, principalmente com os olhos fechados, independente do aparelho, os quais não apresentaram diferenças significativas entre eles.

  13. Efeito da adição de componentes inorgânicos na resistência mecânica de moldes de areia para fundição Effect of addition of inorganic components on the mechanical strength of sand molds for casting

    Directory of Open Access Journals (Sweden)

    M. S. Cilla

    2012-03-01

    Full Text Available O processo de fundição mais rápido, econômico e convencional é o de moldagem em areia a verde, onde o ligante principal é uma argila umedecida (bentonita. Entretanto, devido a exigências tecnológicas, são utilizados também ligantes tóxicos como resinas furânicas, fenólicas ou uretânicas. Novas tecnologias vêm sendo desenvolvidas para a recuperação e inertização das areias, porém as resinas disponíveis atualmente têm como limitação "ecológica" sua origem química. Após sua utilização estes moldes são descartados, e assim, os ligantes tóxicos tornam-se um problema ambiental. Desta maneira, a substituição destes ligantes por compostos orgânicos derivados de fontes renováveis como a resina poliuretana derivada do óleo de mamona minimiza os impactos ambientais, conduzindo o processo de fundição rumo à sustentabilidade, necessária devido ao aumento do rigor da legislação ambiental. Devido ao comportamento térmico do poliuretano vegetal, que se decompõem de maneira mais acentuada quando exposto a altas temperaturas quando comparado aos ligantes orgânicos tradicionais a adição de componentes inorgânicos se faz necessária como promotora da ligação entre os grãos de areia e conseqüente coesão dos moldes durante a etapa de fusão. Neste sentido, o uso de diagramas de fases na previsão do surgimento de fase líquida pela adição de componentes inorgânicos à mistura areia/resina em moldes de areia para fundição e seu efeito na resistência mecânica dos moldes em altas temperaturas, funciona como ferramenta teórica no auxílio à determinação das composições dos moldes de acordo com sua solicitação térmica durante a fusão. Testes iniciais de moldagem e resistência mecânica a temperatura ambiente mostraram que a resina poliuretana derivada da mamona apresenta resultados comparáveis aos das resinas comerciais. Também a adição dos componentes inorgânicos e seu efeito quando submetido a

  14. Custo-utilidade do tratamento do glaucoma primário de ângulo aberto no Brasil

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto Paletta Guedes

    2016-02-01

    Full Text Available RESUMO Objetivo: Determinar a estratégia mais custo-efetiva para o tratamento do glaucoma primário de ângulo aberto em fase inicial, comparando-se as seguintes alternativas: observação, tratamento clínico ou tratamento com laser. Métodos: Por meio de um modelo de Markov, sob a perspectiva do Sistema Único de Saúde (SUS e um horizonte da expectativa de vida média da população brasileira. Comparou-se a razão de custo-utilidade incremental (ICUR entre 3 alternativas de tratamento, assim como seus custos e o ganho em qualidade de vida, medido em QALY (Quality-adjusted life years. Resultados: A ICUR do tratamento inicial com laser e do tratamento inicial com colírios, em relação a não tratar foi de R$ 2.811,39/QALY e R$ 3.450,47/QALY, respectivamente. Ambas as estratégias foram custo-efetivas, com uma discreta vantagem para o tratamento a laser. Esta diferença diminui ainda mais quando se aumenta a idade de entrada no modelo. As duas alternativas propiciaram ganhos significativos de qualidade de vida (em torno de 2,5 QALYs para o tratamento com laser e de 5,0 QALYs para o tratamento com colírios. Conclusão: Tanto o tratamento primário com trabeculoplastia a laser quanto com medicações foram custo-efetivos e proporcionaram ganhos reais de qualidade de vida quando comparados com o não tratamento do GPAA.

  15. Comparação entre os tratamentos aberto e endovascular dos aneurismas da aorta abdominal em pacientes de alto risco cirúrgico Comparison between open and endovascular treatment of abdominal aortic aneurysms in high surgical risk patients

    Directory of Open Access Journals (Sweden)

    Célio Teixeira Mendonça

    2005-09-01

    Full Text Available OBJETIVO: Comparar os resultados dos tratamentos aberto e endovascular de aneurismas da aorta abdominal em pacientes de alto risco cirúrgico. MÉTODOS: O tratamento aberto foi realizado em 31 pacientes, e o endovascular, em 18. Sucesso no tratamento endovascular foi definido como perviedade da endoprótese sem endoleaks ou conversão para tratamento aberto. RESULTADOS: Não houve diferença na mortalidade perioperatória entre o tratamento aberto (dois óbitos [6,45%] em 31 e o endovascular (um óbito [5,55%] em 18 (P = 0,899; também não houve diferença entre a mortalidade tardia no tratamento aberto (dois óbitos [6,9%] em 29 e no endovascular (dois óbitos [11,7%] em 17 (P = 0,572. A taxa de sucesso imediato foi de 100% (31/31 no tratamento aberto e de 66,7% (12/18 no endovascular (P = 0,0006; a taxa de sucesso tardio foi de 100% (27/27 no tratamento aberto e de 73,3% (11/15 no endovascular (P = 0,0047. Os valores médios do tempo de internação na UTI, tempo de internação hospitalar e da perda de sangue para os grupos dos tratamentos aberto e endovascular foram: 65,6 versus 34,1 horas*, 9 versus 5,6 dias* e 932 versus 225 ml*, respectivamente (*P OBJECTIVE: To compare the results of open repair and endoluminal repair of abdominal aortic aneurysms in high surgical risk patients. METHODS: Open repair was performed in 31 patients, and endoluminal repair was performed in 18. Success in the endoluminal repair group was defined as continuing graft function without endoleak or conversion to open repair. RESULTS: No significant difference was found between the perioperative mortality rate for open repair (two deaths [6.45%] in 31 patients and endoluminal repair (one death [5.55%] in 18 patients (P = 0.899; similarly, no significant difference was seen in late mortality between open repair (two deaths [6.9%] in 29 patients and endoluminal repair (two deaths [11.7%] in 17 patients (P = 0.572; The rate of immediate success was 100% (31/31 for

  16. Influência do DNA mitocondrial no glaucoma primário de ângulo aberto sob a visão da cienciometria

    Directory of Open Access Journals (Sweden)

    Leonardo Mariano Reis

    2013-10-01

    Full Text Available OBJETIVO: O glaucoma primário de ângulo aberto é uma doença degenerativa do nervo óptico que se encontra entre as principais causas de cegueira no mundo. Aspectos familiares já foram implicados como fatores importantes e comprovados em inúmeros estudos. Nesse artigo, apresentamos uma revisão sistemática dos trabalhos sobre glaucoma primário de ângulo aberto e DNA mitocondrial e fazemos uma análise estatística à luz dos conceitos da cienciometria. MÉTODOS: A pesquisa bibliográfica de trabalhos envolvendo DNA mitocondrial e glaucoma primário de ângulo aberto foi realizada por meio da base de dados do sítio Scopus. Foi feito o levantamento a partir das palavras-chaves "Mitochondrial DNA" e "Glaucoma" em todos os campos para publicações no período compreendido de 1992 até agosto de 2012. Finalmente, foi realizada a estatística e cienciometria com os principais dados: autores que publicaram sobre o assunto DNA mitocondrial e glaucoma; revistas e outras publicações que tiveram trabalhos relacionados com o tema; Centros de Pesquisa e Universidades que mais publicaram e países onde foram realizados os estudos sobre DNA mitocondrial e glaucoma. RESULTADOS: Identificamos que esses estudos têm aumentado sobremaneira ao longo dos últimos anos, mas ainda se encontram confinados, na maior parte, a alguns centros de pesquisa e concentrados em seletos grupos de autores na área da oftalmologia em países desenvolvidos. No Brasil, ainda não temos pesquisas publicadas sobre o assunto até o momento. CONCLUSÃO: Esses estudos são de fundamental importância para a elucidação das causas genéticas do glaucoma e para o desenvolvimento de novas terapias que não visem tão somente a diminuição da pressão intraocular.

  17. Otimização econômica de explotações a céu aberto

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    Frederico Augusto Rosa do Carmo

    2006-09-01

    Full Text Available A determinação dos limites da cava final de qualquer projeto de mineração é um dos maiores desafios de um projeto de mineração. Tais limites precisam ser definidos já no início dos trabalhos de planejamento de lavra e devem ser reconsiderados, novamente e rotineiramente, durante toda a vida útil da mina. Um dos propósitos do plano de exaustão de minas a céu aberto é determinar a cava final ótima, baseando-se em um modelo econômico sujeito a restrições técnicas e visando à maximização do valor atual líquido do projeto. O primeiro algoritmo específico relacionado ao tema foi publicado por Lerchs e Grossmann (1965. O algoritmo de Lerchs e Grossmann tem sido aceito como padrão de teste em comparação com outros algoritmos equivalentes, que têm sido propostos, porque ele resolve o problema correspondente, segundo a teoria dos grafos, ao corte mínimo e fluxo máximo. Outros algoritmos de otimização de cavas finais de minas a céu aberto também são apresentados nesse trabalho. Além disto, um programa acadêmico para a otimização de cavas foi desenvolvido pelos autores sendo que os fundamentos deste são apresentados no presente artigo.The determination of the final pit limits of any mining project is one of the most important challenges in a mining project. Such limits need to be defined at the beginning of the mine planning and should be reconsidered, again and routinely, during all the useful life of a mine. One of the purposes of the open pit mine exhaustion plan is the determination of the optimal final pit, based on an economic model subject to technical restrictions and aimed to maximize the net present value. LERCHS e GROSSMANN (1965 published the first specific algorithm related to the theme. This algorithm has been accepted as standard in comparison to other equivalent algorithms which have been proposed, because it solves the corresponding problem, according to the graph theory, of the minimum cut and

  18. EDUCAÇÃO DAS RELAÇÕES ÉTNICO-RACIAIS: UM CAMINHO ABERTO PARA A CONSTRUÇÃO DA EDUCAÇÃO INTERCULTURAL CRÍTICA. EDUCATION OF ETHNIC AND RACIAL RELATIONS: AN OPEN PATH TO THE CONSTRUCTION OF A CRITICAL INTERCULTURAL EDUCATION

    Directory of Open Access Journals (Sweden)

    Janssen Felipe da Silva

    2013-05-01

    Full Text Available Este artigo, fruto do diálogo entre uma pesquisa de Mestrado e uma de Doutorado, baseia-se nos Estudos Pós-Coloniais Latino-Americanos (QUIJANO, 2005, 2007; MIGNOLO, 2005, 2011; WALSH, 2008; SARTORELLO, 2009 e versa sobre a Educação das Relações Étnico-Raciais, partindo do questionamento da cosmovisão da sociedade moderna, a qual está pautada na herança colonial (MIGNOLO, 2005, 2011. A partir da problematização da matriz colonial da raça e do racismo vamos interrogando a geopolítica do conhecimento e discutindo os processos de decolonialidade protagonizado pelos Movimentos Sociais Negros. Nossos objetivos são: a apresentar como os Movimentos Sociais Negros no Brasil vêm participando de forma proativa das possibilidades de mudanças na estrutura da educação, dentre elas na proposição e na formulação de políticas de ações afirmativas; b analisar como estas políticas de ações afirmativas no âmbito educacional têm influenciado as Diretrizes Curriculares Nacionais (DCN; c e analisar a relação entre estas políticas e a Educação Intercultural Crítica. Para tanto, a partir dos critérios da Análise de Conteúdo (BARDIN, 2004, selecionamos o corpus e procedemos à análise documental das Diretrizes Curriculares Nacionais promulgadas no período 2001-2011. As análises mostram que a política curricular nacional apresenta elementos que abrem caminhos para a construção de uma Educação Intercultural Crítica e uma Pedagogia Decolonial Antirracista.This article, the result of a dialogue between a Master’s and a Doctorate researches, is based on the Latin American Postcolonial Studies (QUIJANO, 2005, 2007; MIGNOLO, 2005, 2011; WALSH, 2008; SARTORELLO, 2009 and it discusses the Education of Ethnic and Racial Relations, starting from an enquiry of modern society’s cosmovision, which is based on the colonial heritage (MIGNOLO, 2005, 2011. From the colonial matrix problematization of the race and racism we are

  19. Floods and Mold Growth

    Science.gov (United States)

    Mold growth may be a problem after flooding. Excess moisture in the home is cause for concern about indoor air quality primarily because it provides breeding conditions for pests, molds and other microorganisms.

  20. Bleach Neutralizes Mold Allergens

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Researchers at National Jewish Medical and Research Center have demonstrated that dilute bleach not only kills common household mold, but may also neutralize the mold allergens that cause most mold-related health complaints. The study, published in the Journal of Allergy and Clinical Immunology, is the first to test the effect on allergic…

  1. Performance of cultivars of arugula under shade screens and open field /Desempenho de cultivares de rúcula sob telas de sombreamento e campo aberto

    Directory of Open Access Journals (Sweden)

    Sérgio Batista Silva de Souza

    Full Text Available Considering the increasing economic importance and due to the lack of technical information for growing arugula in tropical regions, it was evaluated the performance of arugula cultivated under different shade screens and at open field. Eight treatments were evaluated in a 2x4 factorial design, with two cultivars (Cultivada and Folha Larga x four crop environments (open field, greenhouse shading with 30%, 40% and 50%, with four replications in randomized blocks. The evaluated were plant height, leaf number, fresh and dry matter of the above ground part. Cultivars Folha Larga and Cultivada, showed satisfactory yield: that production in the open field showed acceptable values, showing viable cultivation in the winter in Cáceres-MT, even in warm temperatures, especially for early harvest at around 37 days after sowing. However, cultivation of arugula is favored using 50% shade screen, which can increase the production about 43%.Pelo crescente aumento da importância econômica e perante a escassez de informações técnicas para o cultivo da rúcula em regiões tropicais, avaliou-se o desempenho de rúcula cultivada sob diferentes telados de sombreamento e a campo aberto. Foram avaliados oito tratamentos em esquema fatorial 2x4, sendo duas cultivares (Cultivada e Folha Larga x quatro ambientes de cultivo (campo aberto, telado com sombrite 30%, 40% e 50% com quatro repetições, em blocos casualizados. As características avaliadas foram altura da planta, número de folhas e massas de matéria fresca e de matéria seca parte aérea. Foi observado que as cultivares Folha Larga e Cultivada apresentaram produção satisfatória: a produção em campo aberto apresentou valores aceitáveis, mostrando-se viável o cultivo no período de inverno em Cáceres-MT, mesmo sob temperaturas cálidas, principalmente para colheitas antecipadas por volta dos 37 dias após a semeadura. Porém, o cultivo de rúcula é favorecido sob tela preta 50%, que pode

  2. O EFEITO DE DIFERENTES RELAÇÕES TRY/LANAA DA DIETA SOBRE A ATIVIDADE EXPLORATÓRIA DE RATOS EM CAMPO ABERTO

    OpenAIRE

    Cruz, Rubens [UNESP; Godinho,Pedro Henrique; Sandra Regina GIMENEZ; José Carlos BARNABÉ

    2009-01-01

    RESUMO: O teor de 5-HT cerebral depende da disponibilidade do Try para o cérebro, expressa pela relação TRY/LANAA da dieta. Como a 5-HT está envolvida em vários comportamentos emocionais, procurou-se verificar o efeito de rações com diferentes valores daquela relação na atividade exploratória de ratos em campo aberto. Vários grupos de 6 ratos machos, adultos, alimentados com rações formuladas com Isolado Protéico de milho (IPM) – baixa relação TRY/LNAA - , farinha des...

  3. Relação entre income smoohing e ratings em companhias brasileiras de capital aberto

    OpenAIRE

    Tonin, Joyce Menezes da Fonseca

    2013-01-01

    Resumo: Este estudo teve como objetivo geral analisar a associação entre rating e gerenciamento de resultados contábeis decorrente do income smoothing em companhias de capital aberto com ações negociadas na BM&FBovespa no período de 2005 a 2011. Com a abordagem da informação contábil de Watts e Zimmerman (1986), a Teoria das Escolhas Contábeis de Fiels, Lys e Vicent (2001) e Francis (2001) e as contribuições de Martinez (2001) quantas as modalidades de Gerenciamento de Resultado, avaliou-se o...

  4. GOVERNANÇA CORPORATIVA E CUSTO DE CAPITAL DE TERCEIROS: EVIDÊNCIAS ENTRE EMPRESAS BRASILEIRAS DE CAPITAL ABERTO

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    Camila Veneo Campos Fonseca

    Full Text Available RESUMO O reduzido acesso ao capital de terceiros, especialmente os de mais longo prazo, é um dos principais problemas do ambiente corporativo brasileiro. Conflitos de agência e existência de informação assimétrica nas transações efetivadas no mercado financeiro resultam no racionamento do crédito e no encarecimento do custo de capital. A adoção de melhores práticas de governança corporativa pelas empresas, ao implicar redução do custo de capital, amplia a captação de recursos para o investimento, mitigando o problema do financiamento empresarial. O objetivo deste estudo é avaliar a relação entre a adoção de melhores práticas de governança corporativa e o custo do capital de terceiros das empresas brasileiras não financeiras de capital aberto no período 2010-2014. De forma a atingir tal objetivo, foi utilizado um modelo de dados de painel com 230 companhias, sendo a estimação realizada pelo Método dos Momentos Generalizado Sistêmico (GMM-Sis. Os resultados apontaram que a adoção de melhores níveis de governança corporativa reduziu o custo do capital de terceiros das companhias presentes na amostra. Além disso, verificou-se que as variáveis custo de capital de terceiros do ano anterior, lucratividade e nível de emissão de ações preferenciais exerceram uma influência estatisticamente significativa sobre o custo contemporâneo da dívida.

  5. EFEITOS DO CAPITAL INTELECTUAL SOBRE O DESEMPENHO FINANCEIRO EM COMPANHIAS DE CAPITAL ABERTO

    Directory of Open Access Journals (Sweden)

    Maria Margarete Baccin Brizolla

    2015-06-01

    Full Text Available O objetivo deste estudo foi identificar a influência do Capital Intelectual, medido pelo Valor agregado do Capital Intelectual (VACI sobre o desempenho financeiro em companhias de capital aberto. A classificação do estudo no que se refere aos objetivos é uma pesquisa descritiva, em relação aos procedimentos classifica-se como documental e a abordagem refere-se à análise quantitativa. A investigação que permeia este estudo envolve as características relacionadas ao capital intelectual, em 166 companhias listadas na BM&FBovespa, compondo a amostra no período de 2013. Os dados foram coletados na base de dados Economática®. Quanto à técnica estatística foi utilizada a Correlação Canônica. Os resultados da pesquisa demonstram que o capital intelectual influência significativamente o desempenho financeiro, em companhias de capital aberto.

  6. Mini tunelizador moldável: um avanço técnico no acesso vascular para hemodiálise Mini moldable tunneler: a technical improvement for hemodialysis access

    Directory of Open Access Journals (Sweden)

    Fabio Henrique Rossi

    2011-12-01

    Full Text Available CONTEXTO: A confecção de fístula para hemodiálise pode envolver a criação de túnel para a acomodação do enxerto - veia autóloga ou prótese sintética. O trajeto e a extensão dependem do local escolhido para a realização das anastomoses e posicionamento do trajeto do enxerto. Na atualidade, os tunelizadores utilizados são constituídos de estruturas cilíndricas metálicas rígidas, que tornam necessário o uso de múltiplos tamanhos e conformações. OBJETIVO: Testar a utilização de um único mini tunelizador universal metálico e moldável na cirurgia de confecção de fístula para hemodiálise. MÉTODOS: Trata-se de um estudo piloto. O tunelizador desenvolvido consiste de uma estrutura cilíndrica e modular composta de fio de aço inoxidável moldável interno, com manopla em extremidade proximal e dupla ponta cônica intercambiável em extremidade distal e bainha cilíndrica externa de polietileno. O tunelizador foi utilizado em dez cirurgias de confecção de fístulas para hemodiálise em membros superiores e inferiores, e o sucesso de sua aplicabilidade e a frequência de complicações precoces foram observados. RESULTADOS: Suas características de maleabilidade e conformibilidade permitiram a utilização do mesmo tunelizador nos diversos tipos de fístulas realizadas. A ponta cônica distal com duplo diâmetro, intercambiável, permitiu que o mesmo aparato fosse aplicado na utilização de veia autógena ou prótese sintética. Todas as cirurgias foram seguidas de sucesso e com baixos índices de complicações precoces. CONCLUSÃO: A versatilidade do mini tunelizador metálico maleável e moldável permitiu sua utilização em todas as fístulas realizadas, independentemente do sítio das anastomoses e o trajeto de acomodação escolhido, sem complicações e com excelente índice de perviedade. Os dados sugerem que o mini tunelizador metálico maleável moldável pode ser utilizado com segurança e vantagens nas

  7. Phenolic Molding Compounds

    Science.gov (United States)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  8. Diseño de molde para el establecimiento de la relación entre resultados de análisis térmico y microestructura del aluminio A357 en moldeo por microfusión

    Directory of Open Access Journals (Sweden)

    Espinosa, M.

    2010-12-01

    Full Text Available Melt treatment of aluminium alloys is essential for optimizing their mechanical properties. Thermal analysis methods usually used as control are based on the cooling of the metal in metallic or sand cups. In investment casting, however, cooling takes place in a refractory mould at high temperatures (400-700 °C, where parts are characterized by thin thicknesses, so the results given by thermal analysis devices are not really representative of what happens in the parts. As a result of the present work a mould design is obtained, which adjusts itself to the typology of the parts in investment casting, and will make it possible to establish, in future trials, a relationship between thermal analysis results, microstructure in the part and final mechanical properties.

    El tratamiento del metal fundido resulta esencial para mejorar las propiedades mecánicas de las aleaciones de aluminio. Los métodos de análisis térmico empleados habitualmente como medio de control están basados en el enfriamiento del metal en una copa metálica o en arena. En el caso de la microfusión, el enfriamiento se produce en un molde refractario a alta temperatura (entre 400 y 700°C, en el que las piezas además poseen espesores muy finos, de modo que los resultados de análisis térmico no son del todo fieles a lo que se obtiene en pieza. Como resultado del presente trabajo se obtiene un diseño de molde capaz de ajustarse a la tipología de pieza común en el moldeo a la cera perdida, lo que permitirá establecer, en ensayos futuros, la relación entre los resultados de análisis térmico, la microestructura en pieza y las propiedades mecánicas finales.

  9. Mold design with simulation for chalcogenide glass precision molding

    Science.gov (United States)

    Zhang, Yunlong; Wang, Zhibin; Li, Junqi; Zhang, Feng; Su, Ying; Wang, Zhongqiang

    2016-10-01

    Compare with the manufacturing of the traditional infrared material, such as signal crystal germanium, zinc sulfide, zinc selenide etc, chalcogenide infrared glass is suitable for precision molding for the low soften temperature to have large mass industry production. So the researches of precision glass molding are necessary, especially for the fast development of infrared product. The mold design is one of the key technologies of precision glass molding. In this paper, the mold processing of a sample chalcogenide glass from the technical drawing, mold design, molding to the lens are introduced. From the result of the precision molding, the technology of finite element simulation is a useful way to guiding the mold design. The molded lens by using mold process fit the design requirement.

  10. Silicon micro-mold

    Science.gov (United States)

    Morales, Alfredo M.

    2006-10-24

    The present invention describes a method for rapidly fabricating a robust 3-dimensional silicon-mold for use in preparing complex metal micro-components. The process begins by depositing a conductive metal layer onto one surface of a silicon wafer. A thin photoresist and a standard lithographic mask are then used to transfer a trace image pattern onto the opposite surface of the wafer by exposing and developing the resist. The exposed portion of the silicon substrate is anisotropically etched through the wafer thickness down to conductive metal layer to provide an etched pattern consisting of a series of rectilinear channels and recesses in the silicon which serve as the silicon micro-mold. Microcomponents are prepared with this mold by first filling the mold channels and recesses with a metal deposit, typically by electroplating, and then removing the silicon micro-mold by chemical etching.

  11. Estratégia da Estrutura de Capital sob os Efeitos das Fusões: Estudo de Caso das Instituições de Ensino Superior Brasileiras de Capital Aberto

    Directory of Open Access Journals (Sweden)

    Raul Carlos de Mello

    2010-11-01

    Full Text Available O objetivo deste artigo foi identificar os reflexos produzidos por uma estratégia de crescimento, que se utiliza das fusões, aquisições ou incorporações, sobre a estrutura de capital das instituições de ensino superior brasileiras de capital aberto. A pesquisa utilizada foi de caráter descritivo e o método empregado foi o dedutivo, tendo como meio de investigação o estudo de caso múltiplo. Desse modo, ao elaborar um mapeamento, para o período de 2004 a 2008, de todas as aquisições desenvolvidas pelas instituições de ensino superior brasileiras de capital aberto e dos indicadores relacionados às estruturas de capital, identificou-se uma influência da estratégia de aquisições sobre a estrutura de capital em duas fases: na própria definição da estratégia, ao identificar e usufruir das fontes necessárias para a implantação, e na sua implantação, ao decidir pela agregação das dívidas da empresa adquirida.

  12. Schirmer test performed with open and closed eyes: variations in normal individuals Comparação entre os testes de Schirmer em olhos abertos e fechados em indivíduos normais

    Directory of Open Access Journals (Sweden)

    Leão Gabbay Serruya

    2009-02-01

    Full Text Available PURPOSE: To analyze the difference between measurements of Schirmer test I (ST I and basal Schirmer test (STB with open and closed eyes. METHODS: Sixty eyes of 30 normal volunteers, 12 males and 18 females aged 28 ± 9 years were recruited for the study. All ST were carried out in a closed environment with the absence of airflow (humidity 60 ± 2.34% and temperature 20.72 ± 1.52ºC. ST I and ST B were performed with the individuals' both eyes open and closed with an interval of 6 hours. All ST were conducted in 5 minutes. For statistical analysis, the ST strip's wetting velocity (ST V (in millimeters per minute was calculated, dividing the ST values by its wetting time. If ST values were 35mm before 5 minutes, wetting time was recorded to obtain ST V. RESULTS: ST V measurements of ST I performed with closed eyes (10.30 ± 11.55 were statistically different from those performed with open eyes (18.85 ± 17.88 and ST V measurements of STB performed with closed eyes (3.74 ± 3.14 were statistically different from those performed with open eyes (6.19 ± 5.86. CONCLUSION: ST performed with open or closed eyes can have an important influence in the results of ST I and STB in normal individuals.OBJETIVO: Analisar a diferença das medidas dos testes de Schirmer I e Schirmer basal realizados com os olhos abertos e olhos fechados. MÉTODOS: Foram analisados 60 olhos de 30 indivíduos normais com idade média de 28 ± 9 anos. A umidade média do ar foi de 60 ± 2,34% e a temperatura média de 20,72 ± 1,52ºC. No primeiro dia, foi feito o teste de Schirmer I com os olhos abertos. Após um intervalo de 6 horas, foi realizado o teste de Schirmer I com os olhos fechados. No segundo dia, foi realizado o mesmo procedimento com o teste de Schirmer basal. Para fins de comparação, as medidas das tiras de papel foram divididas pelo tempo de umedecimento das tiras (velocidade para análise estatística. RESULTADOS:No teste de Schirmer I realizado com os olhos

  13. Glass molding process with mold lubrication

    Science.gov (United States)

    Davey, Richard G.

    1978-06-27

    Improvements are provided in glass forming processes of the type wherein hot metal blank molds are employed by using the complementary action of a solid film lubricant layer, of graphite dispersed in a cured thermoset organopolysiloxane, along with an overspray of a lubricating oil.

  14. Mercado aberto e política monetária

    OpenAIRE

    Shashoua, Esther Baker

    1992-01-01

    Esta tese tem como objetivo realizar uma síntese sobre o Mercado Aberto no Brasil, desde a sua implementação em janeiro de 1970, assim como mostrar a sua participação na política monetária. Buscou-se,também, através de instrumentos estatísticos, mostrar evidências sobre o procedimento operacional utilizado pelas Autoridades Monetárias na realização da política monetária e as possíveis mudanças na sua condução, nestes últimos 20 anos.

  15. Mold Image Library

    Science.gov (United States)

    The image library contains mold-related images in seven categories. There are also animated images that you can choose to view and download. These photos may be used for presentations and educational purposes without contacting EPA.

  16. Transferability of glass lens molding

    Science.gov (United States)

    Katsuki, Masahide

    2006-02-01

    Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

  17. Dynamic of taking out molding parts at injection molding

    Directory of Open Access Journals (Sweden)

    E. Ragan

    2012-10-01

    Full Text Available Most plastic parts used in automobile production are manufactured by injection molding. Their quality depends also on taking out molding and on the manipulators for it. Task of this contribution is to theoretically describe a transport of molding at taking out after injection molding in relation on its regulation. The following quantities are derived at it: the transition characteristic of the taking out system, the blocking diagram of taking out molding regulation, the amplitude and phase characteristic and the transition characteristic of action quantity at taking out molding regulation.

  18. Desenvolvimento de PVC reforçado com fibras de vidro longas para fabricação de produtos moldados Long glass fiber reinforcement of PVC molding compounds

    Directory of Open Access Journals (Sweden)

    Leandro H. Grizzo

    2011-01-01

    Full Text Available Neste trabalho foi desenvolvido um método para reforçar PVC rígido com fibras de vidro longas através da incorporação pelo processo de recobrimento da fibra contínua com um composto de PVC plastificado. Posteriormente o filamento foi picotado para a formação de grânulos, com fibras de vidro já incorporadas, que foram misturados mecanicamente ao PVC rígido granulado para alimentação direta por moldagem. A moldagem por injeção direta foi realizada com sucesso não sendo necessário a compostagem prévia, o que foi considerado conveniente, pois reduziu as etapas de processamento da resina de PVC e que proporcionou, possivelmente, redução de custos, redução da degradação do comprimento médio das fibras de vidro e diminuição da possibilidade de degradação da resina de PVC. O reforçamento do PVC rígido com 20% em massa de fibras de vidro longas de comprimento inicial entre 13 e 14 mm resultou em adequadas propriedades mecânicas, bem superiores ao PVC rígido não reforçado. Os módulos (tração e flexão e a resistência ao impacto Charpy praticamente dobraram, mesmo com os compósitos apresentando grande quantidade de plastificante em sua formulação, que possibilita ao PVC ser utilizado em outras aplicações não antes possíveis como em peças técnicas de engenharia.In this paper, a method to reinforce rigid PVC with long glass fibers (LGF was developed through the incorporation of continuous glass fibers, as rovings, with plasticized vinyl matrix prepared by the wire coating technique. The plasticized vinyl rovings were pelletized. The pellets (13-14 mm were then blended to a granulated rigid PVC formulation and directly injection molded as testing specimens. The direct injection molding, eliminating the preliminary melt-compounding process, was achieved successfully, which was considered convenient because it reduced the number of processing steps, which allowed cutting expenses, reduced the deterioration of the

  19. Desarrollo de moldes de prensado con recubrimientos antidesgaste

    OpenAIRE

    Poyatos, A.; Tur, F.; Pérez, José Antonio; Rodríguez, Miguel A.

    2005-01-01

    [ES] El objetivo del presente trabajo ha sido el desarrollo de una nueva concepción de moldes de prensado para la industria del pavimento y revestimiento cerámicos. El empleo de recubrimientos con materiales compuestos metal-cerámica ha permitido, además de multiplicar la vida útil de los moldes por un factor entre 2 y 3 (1.000.000 – 1.500.000 ciclos de prensado), emplear aceros más económicos en la producción del molde, su reutilización, eliminar etapas de alto consumo energético, c...

  20. O EFEITO DE DIFERENTES RELAÇÕES TRY/LANAA DA DIETA SOBRE A ATIVIDADE EXPLORATÓRIA DE RATOS EM CAMPO ABERTO

    Directory of Open Access Journals (Sweden)

    RUBENS CRUZ

    2009-07-01

    Full Text Available

    RESUMO: O teor de 5-HT cerebral depende da disponibilidade do Try para o cérebro, expressa pela relação TRY/LANAA da dieta. Como a 5-HT está envolvida em vários comportamentos emocionais, procurou-se verificar o efeito de rações com diferentes valores daquela relação na atividade exploratória de ratos em campo aberto. Vários grupos de 6 ratos machos, adultos, alimentados com rações formuladas com Isolado Protéico de milho (IPM – baixa relação TRY/LNAA - , farinha desengordurada de soja – alta relação TRY/LNAA – e IPM suplementado com Try foram observados em campo aberto entre 8º/13º e 25º/30º dias de vigência das respectivas dietas. O grupo mantido com o IPM apresentou médias de locomoção e de exploração vertical (“levantar-se” significativamente maiores (α = 0.05 que os demais no primeiro período de observações. Tais diferenças não foram verificadas na segunda fase de observações, quando os grupos mantidos com o IPM e IPM + Try encontravam-se sob forte depleção protéica. Os resultados sugerem que a menor relação TRY/LNAA da dieta e, provavelmente da 5-HT cerebral, aumenta a atividade exploratória, o que pode significar menor nível de emocionalidade. PALAVRAS – CHAVE: Triptofano; serotonina; atividade exploratória.

  1. Influência da Estrutura de Governança Corporativa na Eficiência Financeira: Evidências de Empresas Brasileiras de Capital Aberto

    Directory of Open Access Journals (Sweden)

    Tatiana Marceda Bach

    2015-12-01

    Full Text Available O agente é responsável por atuar no gerenciamento dos interesses do principal e maximizar os lucros da empresa, com o propósito de coordenar e controlar as atividades realizadas por ambos surge a governança corporativa, visando gerar maiores retornos e eficiência. Este artigo objetiva analisar a influência da governança corporativa na eficiência das empresas de capital aberto listadas na BOVESPA. De natureza quantitativa-descritiva, foram analisados dados de 284 empresas no período de 2008 a 2013. Para o cálculo da eficiência foi utilizado a Análise por Envoltória de Dados (DEA e, para a análise dos dados, utilizou-se o software UNCINET 6.0 e o pacote estatístico STATA versão 11.0. A governança foi avaliada a com base no estudo de Silveira (2004 e com base nas recomendações do código de melhores práticas de Governança Corporativa de agências regulamentadoras. A eficiência dos bancos, ao longo de 6 anos, mostrou-se estável e superior ao das demais empresas. A influência da governança corporativa na eficiência é explicada, para as empresas, pelas variáveis estrutura do conselho e estrutura de propriedade, para os bancos, é explicada pelas variáveis acesso às informações, estrutura do conselho, crescimento da receita e ativo total. Este estudo contribui para a identificação das empresas e bancos eficientes, que a partir deste resultado, podem modificar suas ações e estratégias para aumentar sua eficiência corporativa. Para a governança, as variáveis que se mostraram inversamente proporcionais à eficiência poderiam ser revistas pelas empresas com o propósito de contribuir para um maior crescimento e maximização de seus lucros.

  2. Meer bekend over Black Mold

    NARCIS (Netherlands)

    Duyvesteijn, R.G.E.; Kohrman, E.

    2008-01-01

    In de vollegrondsrozenteelt zorgde Black Mold in 2007 voor een groot aantal mislukte oculaties. In 2008 waren er aanzienlijk minder problemen. Uit onderzoek is meer bekend over de oorzaak en bestrijding van Black Mold.

  3. Meer bekend over Black Mold

    NARCIS (Netherlands)

    Duyvesteijn, R.G.E.; Kohrman, E.

    2008-01-01

    In de vollegrondsrozenteelt zorgde Black Mold in 2007 voor een groot aantal mislukte oculaties. In 2008 waren er aanzienlijk minder problemen. Uit onderzoek is meer bekend over de oorzaak en bestrijding van Black Mold.

  4. Análise da capacidade de explicação dos investimentos das empresas brasileiras de capital aberto através do modelo do acelerador

    Directory of Open Access Journals (Sweden)

    Edson Luis Kammler

    2005-12-01

    Full Text Available Este artigo busca analisar a capacidade de explicação dos investimentos das empresas brasileiras de capital aberto através do Modelo do Acelerador modificado. A alteração feita no modelo foi a substituição dos gastos de consumo agregado, ou do estoque de capital do modelo básico, pelo valor das vendas das empresas. Utilizou-se o método dos mínimos quadrados ordinários em corte transversal para estimar os parâmetros do modelo. A aplicação, para a amostra selecionada, da análise referida permitiu verificar uma forte explicação dos gastos de investimentos com o nível de vendas. Sendo assim, é possível, a partir desses resultados, estimar as alterações do investimento de um ano para o outro. Esse fato é extremamente relevante devido à simplicidade do modelo.This paper seeks to explain the investments made by Brazilian firms operating in the capital market, using a modified accelerator model. The modification done in the basic model was the substitution of either the aggregate consumption or the capital stock by the firms' sales value. The parameters of the model were estimated by ordinary least squares using cross-sections. The application of such analysis to the selected sample allowed us to verify a strong correlation between investment expenditures and sales level. Based on these results, we can estimate changes in investments from one year to another. This is extremely important due to the simplicity of the model.

  5. Estresse em pacientes com glaucoma primário de ângulo aberto

    Directory of Open Access Journals (Sweden)

    Maira Santos Marinho Moura

    Full Text Available Glaucoma Primário de Ângulo Aberto (GPAA é uma importante causa de cegueira no mundo. O presente trabalho teve como objetivo investigar: (1 presença e tipo de estresse; (2 relação do número de colírios e estresse; (3 percepção do glaucoma e tratamento. Um estudo transversal e quantitativo foi realizado com 102 pacientes do Ambulatório de Oftalmologia do HC-FMUSP, com roteiro temático e Inventário de Sintomas de Estresse de Lipp. A maioria dos pacientes apresentou estresse (65,7% e não houve correlação entre estresse e número de colírios. "Tempo de tratamento", "dificuldades na vida diária" e "dificuldades em pingar o colírio" foram variáveis independentemente associadas ao estresse. Conclui-se que o estresse pode interferir negativamente no enfrentamento da doença em pacientes com GPAA.

  6. End moldings for cable dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Roose, L.D.

    1993-12-31

    End moldings for high-voltage cables are described wherein the dielectric insulator of the cable is heated and molded to conform to a desired shape. As a consequence, high quality substantially bubble- free cable connectors suitable for mating to premanufactured fittings are made. Disclosed are a method for making the cable connectors either in the field or in a factory, molds suitable for use with the method, and the molded cable connectors, themselves.

  7. Escala diagramática para avaliação de mofo cinzento (Amphobotrys ricini da mamoneira (Ricinus communis L. Diagramatic scale to assess gray mold (Amphobotyrs ricini in castor bean (Ricinus communis L.

    Directory of Open Access Journals (Sweden)

    Haroldo Antunes Chagas

    2010-06-01

    Full Text Available O objetivo do trabalho foi a elaboração de uma escala diagramática para avaliação de mofo cinzento causado por Amphobotrys ricini (Buchw. em mamoneira (Ricinus communis L.. Utilizaram 59 cachos, que foram desinfestados em solução de hipoclorito de sódio a 2% por 30 segundos e em água destilada e esterilizada. Depois foram acondicionados em bandejas com espuma umedecida, onde receberam discos de micélio de 5mm do patógeno, permanecendo em câmara climática a 25ºC e UR de 80%. Observou-se a evolução da doença e foram obtidos fotos dos cachos doentes diariamente. Para a determinação da porcentagem de severidade dos cachos, os frutos infectados e sadios foram contados, estimando-se dessa forma a porcentagem da área lesionada e elaborando uma escala diagramática com seis níveis de severidade. A adoção da escala proposta, melhorou a acurácia (R²=0,94, com valores de "a" não significativamente diferentes de zero (0 e os valores de "b" não diferentes de um (1.The aim of the present study was to develop a diagrammatic scale to assess gray mold caused by Amphobotrys ricini in castor bean (Ricinus communis L.. The experiment included 59 clusters, which were disinfected in solution of sodium hypochlorite to 2% for 30 seconds and distilled water and sterilized. Then, they were packed in moistened foam trays which received 5mm mycelial discs, and were kept in a climatic chamber at 25º C and 80%. RH. The disease evolution was observed daily pictures of the clusters diseased. To determine the severity percentage of the bunches, infected and healthy fruits were counted, estimating thus the percentage of the injured area, and developing a diagrammatic scale with six severity levels. The adoption of the proposed scale, improved the accuracy (R² = 0,94 "a" values were not significantly different from zero (0 and "b" values were not significantly different from one (1.

  8. Phase separation micro molding

    NARCIS (Netherlands)

    Vogelaar, Laura

    2005-01-01

    The research described in this thesis concerns the development of a new microfabrication method, Phase Separation Micro Molding (PSμM). While microfabrication is still best known from semiconductor industry, where it is used to integrate electrical components on a chip, the scope has immensely expan

  9. High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.

    2012-10-05

    This brief report contains a critique of two key components of FiveFocal's cost model for glass compression molding of chalcogenide lenses for infrared applications. Molding preforms and mold technology have the greatest influence on the ultimate cost of the product and help determine the volumes needed to select glass molding over conventional single-point diamond turning or grinding and polishing. This brief report highlights key areas of both technologies with recommendations for further study.

  10. Molded optics design and manufacture

    CERN Document Server

    Schaub, Michael

    2007-01-01

    While several available texts discuss molded plastic optics, none provide information on all classes of molded optics. Filling this gap, Molded Optics: Design and Manufacture presents detailed descriptions of molded plastic, glass, and infrared optics. Since an understanding of the manufacturing process is necessary to develop cost-effective, producible designs, the book extensively covers various manufacturing methods, design guidelines, trade-offs, best practices, and testing of critical parameters. It also discusses topics that often arise when designing systems with molded optics, such as

  11. Diseño y simulación de un sistema de iluminación natural energéticamente eficiente de una planta industrial dedicada a la producción de moldes de inyección de plástico para el sector del automóvil.

    OpenAIRE

    2015-01-01

    [ES] El objetivo del proyecto es el diseño del sistema de iluminación natural de una planta industrial destinada a la producción de moldes por inyección de plástico para el sector automovilístico, y a posteriori, el análisis de la eficiencia energética en iluminación para diversos sistemas de iluminación. Se realizará un presupuesto para el sistema de iluminación natural y un balance económico donde se observe la viabilidad de implantar un sistema de iluminación natural. ...

  12. Estudo clínico, prospectivo, aberto, randomizado e comparativo para avaliar a segurança e a eficácia da luz azul versus peróxido de benzoíla 5% no tratamento da acne inflamatória graus II e III A prospective, randomized, open and comparative study to evaluate the safety and efficacy of blue light treatment versus a topical benzoyl peroxide 5% formulation in patients with acne grade II and III

    Directory of Open Access Journals (Sweden)

    Lúcia H. F. de Arruda

    2009-10-01

    Full Text Available FUNDAMENTOS: Muitos pacientes relatam melhora da acne com a exposição à luz solar, e vários estudos demonstram que a luz azul é efetiva no tratamento da acne. OBJETIVOS: Verificar a segurança e a eficácia da luz azul (espectro eletromagnético de 407 a 420 nm no tratamento da acne inflamatória graus II e III, comparada à terapêutica tópica com peróxido de benzoíla a 5%. MÉTODOS: O estudo avaliou 60 pacientes em cinco visitas: uma de seleção, uma com 7, 14 e 28 dias de tratamento e uma última de seguimento, 14 dias após o término do tratamento. Trinta foram randomizados para luz azul (oito sessões, duas vezes por semana, e outros 30, para peróxido de benzoíla a 5%, duas vezes ao dia, diariamente. A avaliação foi por meio da contagem das lesões e fotografias. RESULTADOS: A redução no número médio de lesões foi semelhante com os dois tratamentos, independente do tipo de lesão (p 0,05, porém o tratamento com a luz azul apresentou menos efeitos colaterais. CONCLUSÕES: A luz azul foi um tratamento tão eficaz quanto o peróxido de benzoíla a 5% para o tratamento da acne graus II e III, mas com menos efeitos adversos.BACKGROUND: Many acne patients improve after exposure to sunlight and there are many reports about the efficacy of blue light phototherapy on acne lesions. OBJECTIVES - The purpose of this study was to evaluate efficacy and safety of blue light treatment versus topical benzoyl peroxide 5% formulation in patients with acne grades II and III. METHODS - Sixty volunteers with facial acne were included and evaluated in 5 visits: the first one for screening, another 3 held on days 7, 14 and 28 of treatment, and the last one after 14 days of the end of treatment. Thirty of them were irradiated with Blue Light (8 times, twice a week and the other thirty were treated with topical Benzoyl Peroxide 5% formulation, auto-applied twice a day, every day. We assessed the severity of acne by counting the lesions and

  13. Efeito de produtos alternativos para o controle do bolor verde (Penicillium digitatum em pós-colheita de citros Effect of the alternative products for control of green mold (Penicillium digitatum in post-harvest citrus fruit

    Directory of Open Access Journals (Sweden)

    DANIEL ANDRADE DE SIQUEIRA FRANCO

    2002-08-01

    Full Text Available O objetivo do trabalho foi verificar a ocorrência de sinergismo entre misturas de produtos alternativos aos fungicidas, para o controle do bolor verde (Penicillium digitatum em pós-colheita de citros. Foram testados dez produtos individualmente e trinta e cinco combinações destes produtos dois a dois, em comparação com tiabendazole e testemunha, com e sem inoculação. Os produtos testados não apresentaram efeito de sinergismo, exceto a mistura carbonato de Na + ácido bórico. Carbonato de Na e ácido bórico controlaram a doença em 78 e 87%, respectivamente, e, utilizando a mistura, o controle foi de 93%. Destacaram-se, ainda no controle da doença, o bicarbonato de Na, metabissulfito de Na e as misturas de bicarbonato de sódio + ácido bórico, carbonato de Na + carbonato de K, carbonato de Na + sorbato de K, bicarbonato de Na + carbonato de Na, controlando 92; 77; 81; 77; 75 e 71%, respectivamente. O tiabendazole utilizado como padrão controlou totalmente a doença.The objective of this work was verify the ocurrence of synergism of mixtures for alternative products to the fungicides for the control of the green mold (Penicillium digitatum in post-harvest citrus fruits. The efficiency of ten products, tested individually, and thirty five combinations among them, in pairs, were compared to thiabendazole and control, with and without inoculation. The products didn't present a synergism effect, except the mixture sodium carbonate + boric acid, that had a disease control of 93%. The products, sodium carbonate and boric acid controled 78 and 87%, respectively. The sodium bicarbonate, sodium methabisulphite and the mixtures of sodium bicarbonate + boric acid, sodium carbonate + potassium carbonate, sodium carbonate + potassium sorbate, sodium bicarbonate + sodium carbonate had a disease control of 92%, 77%, 81%, 77%, 75% and 71%, respectively. The fungicide treatment with thiabendazole used by standard had a whole disease control.

  14. Aspiração endotraqueal por sistema aberto: práticas de profissionais de enfermagem em terapia intensiva

    OpenAIRE

    Frota, Oleci Pereira; Loureiro, Marisa Dias Rolan; Ferreira,Adriano Menis

    2014-01-01

    O objetivo deste estudo foi investigar as práticas dos profissionais de enfermagem de terapia intensiva quanto à aspiração endotraqueal (AET) por sistema aberto. Métodos: Trata-se de uma pesquisa com enfoque quantitativo desenvolvida em um hospital universitário de Mato Grosso do Sul, Brasil, com 25 sujeitos. Os dados, coletados de abril a setembro de 2011 por meio de instrumento de observação do tipo checklist contendo 23 itens da técnica, foram analisados por estatística descritiva. ...

  15. REGULARIDADE NO PAGAMENTO DE DIVIDENDOS E GOVERNANÇA CORPORATIVA: ESTUDO EM COMPANHIAS DE CAPITAL ABERTO LISTADAS NA BM&FBOVESPA

    Directory of Open Access Journals (Sweden)

    Ramon Kael Benassi Bachmann

    2012-08-01

    Full Text Available O objetivo deste estudo é verificar qual a relação entre nível de governança corporativa e regularidade do pagamento de dividendos das companhias de capital aberto listadas na BM&FBOVESPA, entre 2001 e 2010. Empresas listadas na bolsa compuseram três amostras, segregadas conforme (i pagamento de dividendos a acionistas ordinários, (ii preferenciais ou (iii dividendos totais pagos pela companhia. Para representar regularidade admitiu-se como métrica os coeficientes de variação (CV das séries de pagamento de dividendos das companhias, no período analisado. Para os níveis de governança corporativa foram atribuídas duas métricas: uma simples (NG, atribuindo 1 ponto por ano de enquadramento em algum dos níveis, o que considera-os em termos de tempo de enquadramento; e outra ponderada (NGP, atribuindo 1 ponto por ano de enquadramento no Nível 1 (N1, 2 pontos por ano no Nível 2 (N2 e 3 pontos por ano no Novo Mercado (NM, considerando tempo de enquadramento no nível de governança e tipo de nível. Na análise dos dados utilizou-se correlações de Pearson para verificar qual o tipo de relação entre CV e NG e entre CV e NGP, ambos para as 3 amostras. Os resultados indicam que o tempo de enquadramento em qualquer nível de governança, exceto o tradicional, tem relação inversa com regularidade de pagamento de dividendos, reafirmando possíveis gerenciamentos de resultados (income smoothing em companhias não enquadradas ou com pouco tempo de enquadramento. Constatou-se também que o tipo de nível de governança corporativa guarda relação apenas com a regularidade de pagamento de dividendos aos acionistas preferenciais.

  16. Nanofabrication with molds & stamps

    Directory of Open Access Journals (Sweden)

    Byron D. Gates

    2005-02-01

    Full Text Available A number of methods can be used to fabricate patterns with features having dimensions <100 nm. These techniques, however, can require specialized equipment and are often restricted to a cleanroom environment. Nanofabrication can be made accessible to multiple users by using elastomeric molds or stamps to transfer high-resolution patterns into other materials. These techniques are inexpensive and can transfer patterns into functional materials and onto a number of surfaces. This review describes recent advances in fabricating nanostructures using these techniques.

  17. Mold and Crucible Coatings

    Science.gov (United States)

    1986-04-28

    34;" -"""-"’" " " ""’’ "" "" ’"" ’ j * AD I. AT)-E 9 7 W CONTRACTOR REPORT ARCCD-CR-86007 MOLD AND CRUCIBLE COATINGS Sylvia J. Canino Arthur L. Geary Nuclear...IFnlRpr April 1984_-_December 198, .. AUTNORfo) S. CONTRACT on CRAM? # "I MWef(e)I Sylvia J. Canino and Arthur L. Geary DAAK1O-84-C-0056 PERFORMING

  18. Enhanced Injection Molding Simulation of Advanced Injection Molds

    Directory of Open Access Journals (Sweden)

    Béla Zink

    2017-02-01

    Full Text Available The most time-consuming phase of the injection molding cycle is cooling. Cooling efficiency can be enhanced with the application of conformal cooling systems or high thermal conductivity copper molds. The conformal cooling channels are placed along the geometry of the injection-molded product, and thus they can extract more heat and heat removal is more uniform than in the case of conventional cooling systems. In the case of copper mold inserts, cooling channels are made by drilling and heat removal is facilitated by the high thermal conductivity coefficient of copper, which is several times that of steel. Designing optimal cooling systems is a complex process; a proper design requires injection molding simulations, but the accuracy of calculations depends on how precise the input parameters and boundary conditions are. In this study, three cooling circuit designs and three mold materials (Ampcoloy 940, 1.2311 (P20 steel, and MS1 steel were used and compared using numerical methods. The effect of different mold designs and materials on cooling efficiency were examined using calculated and measured results. The simulation model was adjusted to the measurement results by considering the joint gap between the mold inserts.

  19. Injection Compression Molding of Replica Molds for Nanoimprint Lithography

    Directory of Open Access Journals (Sweden)

    Keisuke Nagato

    2014-03-01

    Full Text Available As a breakthrough in the cost and durability of molds for nanoimprint lithography (NIL, replica molds are fabricated by injection compression molding (ICM. ICM is commonly used for optical disks such as DVDs or Blu-ray disks and is also a practical fabrication method for nanostructures. In this paper, I successfully demonstrated the fabrication of cycloolefin polymer replica molds with structures smaller than 60 nm by ICM. Furthermore, ultraviolet (UV-NIL using these replica molds was demonstrated. UV-cured resist was replicated over an area of 60 mm diameter. The degree of replication by UV-NIL in the first usage of each replica mold had good repeatability. Because ICM is a high-throughput, low-cost process, the replica mold can be disposed of after a certain time for UV-NIL. This method leads to a high-integrity UV-NIL process of patterned media because multiple large-area replica molds can be fabricated simultaneously.

  20. Papéis, conflitos e gratificações do enfermeiro de serviços abertos de assistência psiquiátrica

    Directory of Open Access Journals (Sweden)

    Raphael Valentino Marques de Lima

    2010-06-01

    Full Text Available Frente ao processo de transformação da assistência psiquiátrica, o papel de agente terapêutico é preconizado como um dos principais papéis do enfermeiro desta área específica, e, este estudo, objetivou identificar os papéis, conflitos e gratificações do enfermeiro de serviços abertos de assistência psiquiátrica. Trata-se de um estudo descritivo exploratório, onde foi utilizado um questionário, aplicado a onze enfermeiros dos serviços em questão, na cidade de Ribeirão Preto – São Paulo - Brasil. Os resultados mostraram que a maioria está na faixa etária entre 31 e 40 anos e possuem curso de especialização. Três cursaram mestrado e um cursou doutorado. Como papéis, destacaram os específicos do enfermeiro e os administrativos. Como conflitos, apontaram as condições de trabalho, a baixa remuneração, o não reconhecimento da sua liderança e a falta de recursos. O reconhecimento profissional e a reabilitação do portador de transtorno mental constituíram-se nas gratificações relatadas, permitindo concluir que esses enfermeiros identificam com propriedade o seu papel, apontam dificuldade para desempenhar parte deles, principalmente, frente às situações que enfrentam, identificam os seus conflitos e mostraram-se gratificados pelo reconhecimento da contribuição do seu trabalho na reabilitação do portador de transtorno mental, preservando, assim, certo idealismo relativo ao exercício de sua profissão.

  1. Mold Materials For Permanent Molding of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    John F Wallace; David Schwam; Wen Hong dxs11@po.cwru.edu

    2001-09-14

    A test that involves immersion of the potential mod materials for permanent molds has been developed that provides a thermal cycle that is similar to the experienced during casting of aluminum in permanent molds. This test has been employed to determine the relative thermal fatigue resistance of several different types of mold materials. Four commercial mold coatings have been evaluated for their insulating ability, wear resistance and roughness. The results indicate that composition and structure of the mold materials have considerable effect on their thermal fatigue cracking behavior. Irons with a gray iron structure are the most prone to thermal fatigue cracking followed by compacted graphite irons with the least thermal fatigue cracking of the cast irons experienced by ductile iron. The composition of these various irons affects their behavior.

  2. A visibilidade e a qualidade em revistas de Ciências da Comunicação em acesso aberto no contexto ibero-americano, Portugal e Espanha

    OpenAIRE

    Freitas, M. Cristina V. de; Borges, Maria Manuel; Simões, Maria da Graça; Cardoso, Manuela

    2014-01-01

    As revistas são imprescindíveis na divulgação e no acesso à ciência. O acesso aberto potencia esta divulgação e colateral impacto, onde a visibilidade é uma alavanca e a sua qualidade, ou a ausência desta, é uma oportunidade ou um entrave. Este artigo investiga revistas de Ciências da Comunicação em acesso aberto no espaço ibero-americano, Portugal e Espanha, sob o binómio visibilidade/qualidade. Trata-se de um estudo de caso descritivo e interpretativo. Primeiramente recolhe-se uma amostra n...

  3. Thermophilic molds: Biology and applications.

    Science.gov (United States)

    Singh, Bijender; Poças-Fonseca, Marcio J; Johri, B N; Satyanarayana, Tulasi

    2016-11-01

    Thermophilic molds thrive in a variety of natural habitats including soils, composts, wood chip piles, nesting materials of birds and other animals, municipal refuse and others, and ubiquitous in their distribution. These molds grow in simple media containing carbon and nitrogen sources and mineral salts. Polyamines are synthesized in these molds and the composition of lipids varies considerably, predominantly containing palmitic, oleic and linoleic acids with low levels of lauric, palmiotoleic and stearic acids. Thermophilic molds are capable of efficiently degrading organic materials by secreting thermostable enzymes, which are useful in the bioremediation of industrial wastes and effluents that are rich in oil, heavy metals, anti-nutritional factors such as phytic acid and polysaccharides. Thermophilic molds synthesize several antimicrobial substances and biotechnologically useful miscellaneous enzymes. The analysis of genomes of thermophilic molds reveals high G:C contents, shorter introns and intergenic regions with lesser repetitive sequences, and further confirms their ability to degrade agro-residues efficiently. Genetic engineering has aided in ameliorating the characteristics of the enzymes of thermophilic molds. This review is aimed at focusing on the biology of thermophilic molds with emphasis on recent developments in the analysis of genomes, genetic engineering and potential applications.

  4. Sustentabilidade empresarial e o impacto no custo de capital próprio das empresas de capital aberto Sustainable development and consequences for equity costs in public companies

    Directory of Open Access Journals (Sweden)

    Lílian Simone Aguiar da Silva

    2006-12-01

    Full Text Available Este trabalho apresenta o impacto no custo de capital próprio para as empresas brasileiras de capital aberto face à adoção dos princípios de sustentabilidade. O conceito de desenvolvimento sustentável tem se aprimorado num processo contínuo de reavaliação da relação existente entre: crescimento econômico, a sociedade civil e o meio ambiente. O triple-bottom-line das dimensões econômica, ambiental e social da sustentabilidade tem emergido como um modelo de interpretação pelas empresas, embora cada uma dessas dimensões represente um grande desafio. O segmento corporativo vem atendendo às demandas cada vez maiores da sociedade frente a essas questões, ficando a dúvida quanto à legitimidade dessas ações e o questionamento relativo ao papel das empresas na economia e na sociedade. Para avaliar o impacto no custo de capital próprio, foi implementado um modelo de decomposição do beta em medidas contábeis de risco, incluindo uma variável referente à sustentabilidade. O resultado confirma a expectativa de que ao aderir aos padrões de sustentabilidade a empresa reduz o risco corporativo medido pelo risco sistemático, determinando a redução do custo de capital e aumento do valor econômico.This article provides an analysis of equity costs in Brazilian public companies regarding the adoption of sustainability principles. The concept of sustainable development has evolved considering the relation among economic growth, the society and the environment. The triple-bottom-line of economic, environmental, and social dimensions has emerged as an interpretation model by companies, although each of these dimensions may present a challenge. The corporate sector has faced an increasing demand from society regarding these sustainability concepts, though the actions and the role to be played by companies within this context are still being questioned. Equity costs were analyzed by a multivariate regression of beta on accounting measures

  5. Injection Molding of High Aspect Ratio Nanostructures

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels Bent

    We present a process for injection molding of 40 nm wide and >100 nm high pillars (pitch: 200 nm). We explored the effects of mold coatings and injection molding conditions on the replication quality of nanostructures in cyclic olefin copolymer. We found that optimization of molding parameters...

  6. Rapid control of mold temperature during injection molding process

    Energy Technology Data Exchange (ETDEWEB)

    Liparoti, Sara; Titomanlio, Giuseppe [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132, 84084 Fisciano (Italy); Hunag, Tsang Min; Cakmak, Mukerrem [Department of Polymer Engineering, The University of Akron, Akron, OH 44325 (United States); Sorrentino, Andrea [Institute for Polymers, Composite and Biomaterials (IPCB) - CNR, P. Enrico Fermi 1, 80055 Portici (Italy)

    2015-05-22

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  7. A indústria de publicação contra o acesso aberto La industria de publicación contra el acceso abierto The publishing industry against open access journals

    Directory of Open Access Journals (Sweden)

    Kenneth Rochel de Camargo Jr

    2012-12-01

    Full Text Available A publicação em revistas de acesso aberto cresceu expressivamente nos últimos anos. As publicações de acesso fechado, por sua vez, têm custo de acesso cada vez mais elevado, por se beneficiarem de um modelo econômico peculiar: o trabalho relevante e os insumos essenciais são entregues gratuitamente a fornecedores que contam com um mercado cativo, praticamente sem concorrência. O mercado editorial é altamente oligopolizado, característico de indústrias que trabalham com o regime de copyright. Isso contribui para a elevação dos preços de seus produtos. Políticas mandatórias de acesso aberto, como a determinada pela agência National Institutes of Health, constituem-se em ameaça a esse modelo de negócios e são enfrentadas pela indústria em várias frentes, incluindo a passagem de legislação para sabotar tais iniciativas. O objetivo deste comentário foi apresentar alguns aspectos principais desse enfrentamento e sugerir possíveis estratégias de incremento da publicação de acesso aberto em nosso meio.La publicación en revistas de acceso abierto creció expresivamente en los últimos años. Las publicaciones de acceso cerrado, por su parte, tienen costo de acceso cada vez más elevado, por beneficiarse de un modelo económico peculiar: el trabajo relevante y los insumos esenciales son entregados gratuitamente a los proveedores que cuentan con un mercado cautivo, prácticamente sin concurrencia. El mercado editorial es altamente monopolizado, característico de industrias que trabajan con el régimen de copyright. Esto contribuye a la elevación de los precios de sus productos. Políticas obligatorias de acceso abierto, como la determinada por el National Institutes of Health, constituyen amenazas a este modelo de negocios y son enfrentadas por la industria en varios ángulos, incluyendo el paso de legislación para sabotear tales iniciativas. El objetivo de este comentario fue presentar algunos aspectos principales de este

  8. White mold of Jerusalem artichoke

    Science.gov (United States)

    Jerusalem artichoke (Helianthus tuberosus) is a Native American food plant closely related to the common sunflower (Helianthus annuus). Tubers of Jerusalem artichoke are increasingly available in retail grocery outlets. White mold (Sclerotinia stem rot), caused by the fungus, Sclerotinia sclerotioru...

  9. Prevention of Mold Contamination : Ozone Treatment

    OpenAIRE

    Nakarmi, Kanchan

    2016-01-01

    Mold is a common pest that can cause diseases and decay property. Moreover, certain mold can produce toxic chemicals which leads directly or indirectly to additional health impacts and economic losses. Therefore, prevention of mold growth is a major concern, and disinfection of mold has become a center of attention. The purpose of this thesis was to study about the effect of ozone in the disinfection of mold and the method of producing ozone. The usage of ozone for disinfection in in...

  10. Onychomycosis due to opportunistic molds*

    OpenAIRE

    Martínez-Herrera, Erick Obed; Arroyo-Camarena,Stefanie; Tejada-García, Diana Luz; Porras-López, Carlos Francisco; Arenas, Roberto

    2015-01-01

    Abstract BACKGROUND: Onychomycosis are caused by dermatophytes and Candida, but rarely by non- dermatophyte molds. These opportunistic agents are filamentous fungi found as soil and plant pathogens. OBJECTIVES: To determine the frequency of opportunistic molds in onychomycosis. METHODS: A retrospective analysis of 4,220 cases with onychomycosis, diagnosed in a 39-month period at the Institute of Dermatology and Skin surgery "Prof. Dr. Fernando A. Cordero C." in Guatemala City, and confirmed w...

  11. Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

    DEFF Research Database (Denmark)

    Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan;

    2015-01-01

    We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process...

  12. Estudo de caso de peça moldada pelo processo de injeção-compressão para termoplásticos utilizando análise computacional Study of injection-compression molded part using CAE analysis

    Directory of Open Access Journals (Sweden)

    Thyago M. Kiam

    2007-03-01

    Full Text Available O processamento de termoplásticos através do processo de injeção representa o principal método de fabricação de peças plásticas. Limitações do processo de injeção convencional, principalmente quanto à matéria-prima e configuração e funcionamento das máquinas disponíveis, tornam inviável a produção de produtos com grande área projetada e pequena espessura, como janelas automotivas e alguns tipos de lentes. Paralelamente, o processo de injeção evolui continuamente e há uma série de novas tecnologias geradas a partir do processo original, dentre elas o processo de injeção-compressão. No presente trabalho, utilizando análise computacional, estudou-se a produção de lentes de policarbonato através de dois processos distintos: injeção convencional e processo de injeção-compressão. A seqüência de estudos envolveu basicamente os seguintes pontos: estudo do padrão de preenchimento com conseqüente otimização do processo de injeção-compressão quanto à formação de linha de emenda; estudo da janela de processo para ambos os casos e comparação de alguns parâmetros principalmente tensão de cisalhamento e força de fechamento, por se tratarem de fatores limitantes na produção de peças com grande área projetada. Os resultados para o caso estudado comprovam grande vantagem na utilização do processo de injeção-compressão.The injection-molding of thermoplastics is the main process used in the production of plastics parts. There are some limitations in the conventional injection process, specially related to raw materials, machines configuration and operation, which hamper fabrication of thin parts with large areas such as car windows and lenses. On the other hand, the process has been improved continuously with several new technologies, going beyond the conventional injection molding process, including the "injection-compression" process. In this paper, using CAE (computer aided engineering technology

  13. Concentração de propriedade e desempenho: um estudo nas empresas brasileiras de capital aberto do setor de energia elétrica

    Directory of Open Access Journals (Sweden)

    Naiara Leite dos Santos Sant'Ana

    2016-01-01

    Full Text Available Resumo A concentração de propriedade há muito vem sendo estudada para verificar se impacta no desempenho das empresas. O presente artigo tem por objetivo verificar se a estrutura de propriedade, mais especificamente a concentração de propriedade, tem algum impacto no desempenho das empresas do setor elétrico. Embora sejam numerosos os trabalhos que tratam sobre a relação de Desempenho e Concentração de Propriedade, este se propõe a apresentar uma proposta de abordagem metodológica por meio de uma nova combinação de variáveis. O trabalho busca reacender a discussão da concentração de propriedade no Brasil e a identidade desses acionistas em um cenário peculiar de escândalos de má gestão, controle de resultados e corrupção de empresas no Brasil, sob a óptica da relação entre capital privado e público, com a análise sendo feita no setor de energia elétrica. O estudo foi realizado por meio da análise de dados em painel. A amostra compôs-se de 22 empresas brasileiras de capital aberto do setor de energia elétrica analisadas nos anos de 2010 a 2014. Verificou-se melhor desempenho das empresas privadas em comparação com as públicas, das empresas com ações ordinários nas mãos de apenas um acionista majoritário e relação positiva com o lucro líquido. Por outro lado, as variáveis relativas às ações ordinárias nas mãos de dois maiores acionistas e ativo total apresentaram relação negativa com o desempenho.

  14. Simplex network modeling for press-molded ceramic bodies incorporated with granite waste; Dosagem de massa ceramica para blocos prensados com adicao de residuo de granito atraves do metodo simplex

    Energy Technology Data Exchange (ETDEWEB)

    Pedroti, L.G.; Vieira, C.M.F.; Alexandre, J.; Monteiro, S.N.; Xavier, G.C., E-mail: lpedroti@gmail.com [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil)

    2012-07-01

    Extrusion of a clay body is the most commonly applied process in the ceramic industries for manufacturing structural block. Nowadays, the assembly of such blocks through a fitting system that facilitates the final mounting is gaining attention owing to the saving in material and reducing in the cost of the building construction. In this work, the ideal composition of clay bodies incorporated with granite powder waste was investigated for the production of press-molded ceramic blocks. An experimental design was applied to determine the optimum properties and microstructures involving not only the precursors compositions but also the press and temperature conditions. Press load from 15 ton and temperatures from 850 to 1050°C were considered. The results indicated that varying mechanical strength of 2 MPa to 20 MPa and varying water absorption of 19% to 30%. (author)

  15. Functional nanostructures on injection molded plastic

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; Søgaard, Emil; Andersen, Nis Korsgaard

    Nanotechnology can be used to make inexpensive plastic parts with functional surfaces. The plastic parts can be molded using a standard injection molding process. The nanostructures are directly transferred from the surface of the molding tool to the surface of the molded plastic part during...... the molding process. The main advantage with this method is that surface treatments and chemical additives are avoided, which minimizes health risks and simplifies recycling. Another advantage is that the unique technology enables nanostructuring of free form molded parts. The functional surfaces can have...

  16. Grau de exposição a praguicidas organoclorados em moradores de aterro a céu aberto

    Directory of Open Access Journals (Sweden)

    Santos Filho Eladio

    2003-01-01

    Full Text Available OBJETIVO: Estimar o grau de exposição interna aos praguicidas organoclorados (POP dos moradores de um atêrro a céu aberto. MÉTODOS: Estudo observacional, de aferição simultânea e controlado, cujo fator de estudo foi residir em área contaminada por POP e o efeito foi a concentração sanguínea dessas substâncias. A população de estudo foi de 238 pessoas residentes em um aterro a céu aberto (Pilões, no município de Cubatão, SP; e a população de controle ficou dimensionada em 258 pessoas, também residentes no mesmo município (Cota 200. Foram analisados os praguicidas HCB, p-p'DDT, p-p'DDE, p-p'DDD, o-p'DDT, a HCH; b HCH; g HCH; Aldrin; Dieldrin; Endrin; Heptaclor; Heptaclor-epoxi e Mirex. RESULTADOS: Os teores médios sangüíneos de HCB em Pilões foram de 4,66 µg/L, 155 vezes maior que a média na Cota 200 (0,03 µg/L. Em Pilões, os teores médios de DDT total foram de 3,71 µg/L, duas vezes maior do que na Cota 200 (1,85 µg/L e o HCH total apresentou concentrações sangüíneas seis vezes maiores em Pilões, 0,84 µg/L, contra 0,13 µg/L. CONCLUSÕES: Evidenciou-se associação positiva entre residir em Pilões e apresentar teores sangüíneos de POP, com risco muitas vezes maior quando comparado a localidades sem a presença desses contaminantes.

  17. Grau de exposição a praguicidas organoclorados em moradores de aterro a céu aberto

    Directory of Open Access Journals (Sweden)

    Eladio Santos Filho

    2003-08-01

    Full Text Available OBJETIVO: Estimar o grau de exposição interna aos praguicidas organoclorados (POP dos moradores de um atêrro a céu aberto. MÉTODOS: Estudo observacional, de aferição simultânea e controlado, cujo fator de estudo foi residir em área contaminada por POP e o efeito foi a concentração sanguínea dessas substâncias. A população de estudo foi de 238 pessoas residentes em um aterro a céu aberto (Pilões, no município de Cubatão, SP; e a população de controle ficou dimensionada em 258 pessoas, também residentes no mesmo município (Cota 200. Foram analisados os praguicidas HCB, p-p'DDT, p-p'DDE, p-p'DDD, o-p'DDT, a HCH; b HCH; g HCH; Aldrin; Dieldrin; Endrin; Heptaclor; Heptaclor-epoxi e Mirex. RESULTADOS: Os teores médios sangüíneos de HCB em Pilões foram de 4,66 µg/L, 155 vezes maior que a média na Cota 200 (0,03 µg/L. Em Pilões, os teores médios de DDT total foram de 3,71 µg/L, duas vezes maior do que na Cota 200 (1,85 µg/L e o HCH total apresentou concentrações sangüíneas seis vezes maiores em Pilões, 0,84 µg/L, contra 0,13 µg/L. CONCLUSÕES: Evidenciou-se associação positiva entre residir em Pilões e apresentar teores sangüíneos de POP, com risco muitas vezes maior quando comparado a localidades sem a presença desses contaminantes.

  18. El tratamiento de QPQ en el mejoramiento mecánico y químico de los aceros para moldes de plástico: caso de AISI P20

    Directory of Open Access Journals (Sweden)

    Rónald Jiménez Salas

    2010-12-01

    Full Text Available El QPQ es un tratamiento termoquímicoaplicado principalmente a las aleacionesferrosas y de níquel para mejorar sucomportamiento mecánico y su resistenciaa la corrosión.En este artículo se presentanlos primeros resultados del proyecto dela validación de las propiedades de losaceros de herramientas para la industriade procesamiento de plásticos en CostaRica, obtenidas al aplicarle el tratamientotermoquímico de QPQ, y particularmentelos resultados de durezas y espesores decapa obtenidos en aceros AISI P20.Para el desarrollo de la investigación, seprepararon probetas pulidas y se tratarona diferentes tiempos; luego, se realizaronestudios metalográficos y de microdurezapara caracterizar las propiedades obtenidas.Por último, los resultados muestran valoresde dureza y espesores de capa acordes conlos esperados para este tipo de aceros debaja aleación.

  19. CO2 production in extruded dry foods for dogs exposed to different moisture levels with and without use of mold inhibitorProdução de CO2 em dietas extrusadas para cães submetidas a diferentes níveis de umidade com e sem utilização de antifúngico

    Directory of Open Access Journals (Sweden)

    Everton Luis Krabbe

    2013-05-01

    Full Text Available Four extruded dog foods with different moisture contents and ammonium propionate (AP were manufactured with the objective of evaluating CO2 production. The diets were: low moisture (8.1% with no inclusion of ammonium propionate (LMNP, high moisture (10.2% with no inclusion of AP (HMNP, high moisture with inclusion of a low level of AP (0.065% (HMLP, and high moisture with inclusion of a high level of AP (0.130% (HMHP. The diets were stored in a chamber at 75% air relative humidity and 25-28ºC temperature. CO2 was determined on days 0, 30, 60, and 90 by titration with hydrochloric acid (HCl 0.05N to estimate mold growth. A completely randomized splitplot experimental design was applied. The diet HMNP measured in 90 days presented the highest CO2 concentration and mycotoxins production. Dry dog foods with moisture content higher than 10.2% without mold inhibitors may present significant mold growth and mycotoxis production after 90 days storage. Extruded dry foods for dogs with less than 8.1% moisture may not need mold inhibitors.Foram avaliadas quatro dietas extrusadas para cães com diferentes níveis de umidade, com adição ou não de ácido propiônico (PA, com o objetivo de avaliar a produção de CO2 e micotoxinas. As dietas foram: baixa umidade (8,1% sem inclusão de propionato de amônio (BUSP, alta umidade (10,2% sem inclusão de PA (AUSP, alta umidade com inclusão de baixo nível de PA (0,065% (AUBP, e alta umidade com inclusão de alto nível de propionato (0,130% (AUAP. As dietas foram armazenadas em câmara com umidade relativa do ar de 75% e temperatura de 25 a 28 ºC. A produção de CO2 foi determinada nos tempos zero, 30, 60 e 90 dias por meio de titulação com ácido clorídrico (HCl 0,05N. O experimento seguiu delineamento inteiramente casualizado em parcela subdividida no tempo. A dieta AUSP, medida aos 90 dias, apresentou maior concentração de CO2 e produção de micotoxinas. Alimentos secos extrusados para cães com

  20. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    2013-01-01

    having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...... of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer....

  1. Cranioplastia primária nos afundamentos do crânio com ferimento aberto do couro cabeludo

    Directory of Open Access Journals (Sweden)

    Darcy de Freitas Vellutini

    1972-06-01

    Full Text Available Os autores referem 13 casos de afundamentos crânio-encefálicos pós-traumáticos com ferimento aberto do couro cabeludo nos quais foi usado o metilmetacrilato em uma única intervenção cirúrgica. A sede do afundamento era frontal em 9 casos, parietal em dois, parieto-temporal em um e parieto-occipital em um. Os afundamentos interessavam apenas a tábua óssea em 5 casos, estavam associados a lesão de dura-mater em três e também do tecido cerebral em 5. Foi realizada cranioplastia simples em 5 casos e, em 8, ela foi precedida de plástica de dura-mater. O seguimento pós-operatório variou de dois meses a dois anos; até o momento não foi assinalada ocorrência de infecção ou de fenômeno de rejeição da prótese que obrigasse a sua retirada.

  2. Surface microstructure replication in injection molding

    DEFF Research Database (Denmark)

    Theilade, Uffe Arlø; Hansen, Hans Nørgaard

    2006-01-01

    In recent years, polymer components with surface microstructures have been in rising demand for applications such as lab-on-a-chip and optical components. Injection molding has proven to be a feasible and efficient way to manufacture such components. In injection molding, the mold surface topogra...

  3. Injection Molding of Plastics from Agricultural Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, M.; Ruan, R.

    2001-02-22

    The objective of this research was to conduct a systematic study to relate injection molding parameters to properties of blends of starch and synthetic polymer. From this study, we wished to develop a thorough understanding of the injection molding process and gain significant insight into designing molds and aiding in developing products cheaply and efficiently.

  4. Planning an Injection Mold Design Training Program.

    Science.gov (United States)

    Allyn, Edward P.

    With the increased use of plastics worldwide the shortage of trained personnel in moldmaking and design for plastic injection molds is becoming critical. Local schools and community colleges should provide courses in mold design and mold making, since most workers presently learn while working under experienced designers on the job. Following this…

  5. Is Mold the New Asbestos?

    Science.gov (United States)

    Colgan, Craig

    2003-01-01

    Mold and indoor air quality (IAQ) are matters of major concern to architects and their educational clients. The Environmental Protection Agency's Indoor Air Quality Tools for Schools program offers help to districts seeking to tackle IAQ issues. Strengthening community relations is one way to be ready in case of a bad environmental or IAQ report.…

  6. Stochastic resin transfer molding process

    CERN Document Server

    Park, M

    2016-01-01

    We consider one-dimensional and two-dimensional models of stochastic resin transfer molding process, which are formulated as random moving boundary problems. We study their properties, analytically in the one-dimensional case and numerically in the two-dimensional case. We show how variability of time to fill depends on correlation lengths and smoothness of a random permeability field.

  7. Is Mold the New Asbestos?

    Science.gov (United States)

    Colgan, Craig

    2003-01-01

    Mold and indoor air quality (IAQ) are matters of major concern to architects and their educational clients. The Environmental Protection Agency's Indoor Air Quality Tools for Schools program offers help to districts seeking to tackle IAQ issues. Strengthening community relations is one way to be ready in case of a bad environmental or IAQ report.…

  8. Molded Concrete Center Mine Wall

    Science.gov (United States)

    Lewis, E. V.

    1987-01-01

    Proposed semiautomatic system forms concrete-foam wall along middle of coal-mine passage. Wall helps support roof and divides passage into two conduits needed for ventilation of coal face. Mobile mold and concrete-foam generator form sections of wall in place.

  9. Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

    OpenAIRE

    Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan; Pranov, Henrik J.; Larsen, Niels Bent

    2015-01-01

    We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process. At isothermal mold conditions, the average pillar height increases by up to 100% and a more uniform height distribution is observed compared to a traditional metal mold insert. Thermal heat transfer simulat...

  10. Restrição externa e crescimento simulando um modelo multissetorial aberto

    Directory of Open Access Journals (Sweden)

    Maria Isabel Busato

    Full Text Available Resumo O artigo busca discutir a dinâmica do crescimento econômico das economias em desenvolvimento a partir do Princípio da Demanda Efetiva keynesiano e kaleckiano e dos Modelos de crescimento liderado pela demanda e restrito pelo balanço de pagamentos, concebidos pela Cepal e desenvolvidos principalmente por Thirlwall. Para tanto, desenvolveu-se um modelo teórico de simulação capaz de captar os efeitos sobre as taxas de crescimento e sobre as condições externas quando a economia estilizada é submetida a diferentes padrões de crescimento. As principais conclusões foram: i as taxas de crescimento de uma economia cuja dinâmica é exclusivamente impulsionada pelas condições internas (de política expansionista serão em algum momento restringidas por imposições do balanço de pagamentos; e ii se os setores produtivos conseguem introduzir uma dinâmica inovativa capaz de aumentar a competitividade de seus produtos, aumentando o coeficiente de exportação, a economia crescerá impulsionada pela dinâmica interna, postergando, mas não eliminando o risco de vulnerabilidade externa.

  11. Precision injection molding of freeform optics

    Science.gov (United States)

    Fang, Fengzhou; Zhang, Nan; Zhang, Xiaodong

    2016-08-01

    Precision injection molding is the most efficient mass production technology for manufacturing plastic optics. Applications of plastic optics in field of imaging, illumination, and concentration demonstrate a variety of complex surface forms, developing from conventional plano and spherical surfaces to aspheric and freeform surfaces. It requires high optical quality with high form accuracy and lower residual stresses, which challenges both optical tool inserts machining and precision injection molding process. The present paper reviews recent progress in mold tool machining and precision injection molding, with more emphasis on precision injection molding. The challenges and future development trend are also discussed.

  12. Implementation of Molding Constraints in Topology Optimization

    DEFF Research Database (Denmark)

    Marx, S.; Kristensen, Anders Schmidt

    2009-01-01

    In many cases the topology optimization method yield inadmissible solutions in respect to a particular manufacturing process, e.g. injection molding. In the present work it is chosen to focus on the most common injection molding parameters/factors determining the quality of the mold geometry, i.......e. uniform thickness, filling of the die and ejection of the molded item, i.e. extrusion. The mentioned injection mold parameters/factors are introduced in the topology optimization by defining a centerline of the initial domain and then penalize elements in respect to the distance to the defined centerline...

  13. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    2013-01-01

    comprising a chemically bonded monolayer of silane compounds on the at least one surface wherein the silane is a halogenated silane. The at least one surface coated with the anti-stiction coating may be configured to withstand an injection molding process at a pressure above 100 MPa. Furthermore, a mold......A method of preparing an aluminum mold for injection molding is provided, the method comprises the steps of providing an aluminum mold having a least one surface, subjecting the at least one surface to a gas or liquid phase silane to thereby form an anti-stiction coating, the anti-stiction coating...... having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...

  14. Numerical Analysis of Mold Deformation Including Plastic Melt Flow During Injection Molding

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Joon Tae; Lee, Bong-Kee [Chonnam National University, Gwangju (Korea, Republic of)

    2014-07-15

    In the present study, a numerical analysis of an injection molding process was conducted for predicting the mold deformation considering non-Newtonian flow, heat transfer, and structural behavior. The accurate prediction of mold deformation during the filling stage is important to successfully design and manufacture a precision injection mold. While the local mold deformation can be caused by various factors, a pressure induced by the polymer melt is considered to be one of the most significant ones. In this regard, the numerical simulation considering both the melt filling and the mold deformation was carried out. A mold core for a 2D axisymmetric center-gated disk was used for the demonstration of the present study. The flow behavior inside the mold cavity and temperature distribution were analyzed along with the core displacement. Also, a Taguchi method was employed to investigate the influence of the relevant parameters including flow velocity, mold core temperature, and melt temperature.

  15. Compression molding of aerogel microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Pekala, Richard W. (Pleasant Hill, CA); Hrubesh, Lawrence W. (Pleasanton, CA)

    1998-03-24

    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50-800 kg/m.sup.3 (0.05-0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization.

  16. Compression molding of aerogel microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Pekala, R.W.; Hrubesh, L.W.

    1998-03-24

    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner is disclosed. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50--800 kg/m{sup 3} (0.05--0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization. 4 figs.

  17. Onychomycosis due to opportunistic molds*

    Science.gov (United States)

    Martínez-Herrera, Erick Obed; Arroyo-Camarena, Stefanie; Tejada-García, Diana Luz; Porras-López, Carlos Francisco; Arenas, Roberto

    2015-01-01

    BACKGROUND: Onychomycosis are caused by dermatophytes and Candida, but rarely by non- dermatophyte molds. These opportunistic agents are filamentous fungi found as soil and plant pathogens. OBJECTIVES: To determine the frequency of opportunistic molds in onychomycosis. METHODS: A retrospective analysis of 4,220 cases with onychomycosis, diagnosed in a 39-month period at the Institute of Dermatology and Skin surgery "Prof. Dr. Fernando A. Cordero C." in Guatemala City, and confirmed with a positive KOH test and culture. RESULTS: 32 cases (0.76%) of onychomycosis caused by opportunistic molds were confirmed. The most affected age group ranged from 41 to 65 years (15 patients, 46.9%) and females were more commonly affected (21 cases, 65.6%) than males. Lateral and distal subungual onychomycosis (OSD-L) was detected in 20 cases (62.5%). The microscopic examination with KOH showed filaments in 19 cases (59.4%), dermatophytoma in 9 cases (28.1%), spores in 2 cases (6.25%), and filaments and spores in 2 cases (6.25%). Etiologic agents: Aspergillus sp., 11 cases (34.4%); Scopulariopsis brevicaulis, 8 cases (25.0%); Cladosporium sp., 3 cases (9.4%); Acremonium sp., 2 cases (6.25%); Paecilomyces sp., 2 cases (6.25%); Tritirachium oryzae, 2 cases (6.25%); Fusarium sp., Phialophora sp., Rhizopus sp. and Alternaria alternate, 1 case (3.1%) each. CONCLUSIONS: We found onychomycosis by opportunistic molds in 0.76% of the cases and DLSO was present in 62.5%. The most frequent isolated etiological agents were: Aspergillus sp. and Scopulariopsis brevicaulis. PMID:26131862

  18. Gating of Permanent Molds for ALuminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  19. Effect of Functional Nano Channel Structures Different Widths on Injection Molding and Compression Molding Replication Capabilities

    DEFF Research Database (Denmark)

    Calaon, M.; Tosello, G.; Garnaes, J.

    The present study investigates the capabilities of the two employed processes, injection molding (IM) and injection compression molding (ICM) on replicating different channel cross sections. Statistical design of experiment was adopted to optimize replication quality of produced polymer parts wit...

  20. Porous media heat transfer for injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Neil Reginald

    2016-05-31

    The cooling of injection molded plastic is targeted. Coolant flows into a porous medium disposed within an injection molding component via a porous medium inlet. The porous medium is thermally coupled to a mold cavity configured to receive injected liquid plastic. The porous medium beneficially allows for an increased rate of heat transfer from the injected liquid plastic to the coolant and provides additional structural support over a hollow cooling well. When the temperature of the injected liquid plastic falls below a solidifying temperature threshold, the molded component is ejected and collected.

  1. Impacto do sistema de aspiração traqueal aberto e fechado na incidência de pneumonia associada à ventilação mecânica: revisão de literatura Impact of the open and closed tracheal suctioning system on the incidence of mechanical ventilation associated pneumonia: literature review

    Directory of Open Access Journals (Sweden)

    Fernanda Maia Lopes

    2009-03-01

    Full Text Available A pneumonia é a infecção nosocomial mais comum em unidades de terapia intensiva, sendo a ventilação mecânica um fator fortemente associado ao seu desenvolvimento. O objetivo deste estudo foi descrever o impacto do sistema de aspiração traqueal aberto e fechado na incidência de pneumonia associada à ventilação mecânica. Realizou-se uma pesquisa na base de dados Pubmed para identificar tentativas controladas aleatórias, publicadas no período de 1990 a novembro de 2008. Nove estudos foram incluídos. Dos estudos revisados, sete não observaram redução significante da incidência de pneumonia associada à ventilação mecânica com o uso do sistema fechado comparado ao aberto, sendo que dois destes verificaram que o uso do sistema fechado resulta em incremento nas taxas de colonização sem incrementar sua incidência e um observou que o uso do sistema fechado não incrementa a colonização do trato respiratório e reduz a expansão de infecção resultando em redução nas taxas de sepse. Apenas dois estudos verificaram redução na incidência de pneumonia associada à ventilação mecânica com o uso do sistema fechado, e um destes revelou um risco 3.5 vezes maior de desenvolvimento desta infecção com o sistema aberto. Os resultados sugerem que o impacto do sistema de aspiração traqueal aberto e fechado é semelhante para o desenvolvimento da pneumonia associada à ventilação mecânica, assim a escolha do tipo de sistema de aspiração traqueal deve ser baseada em outros parâmetros. Entretanto, o sistema fechado aumenta o risco de colonização do trato respiratório, mas apresenta como vantagens a manutenção da ventilação mecânica e o menor prejuízo hemodinâmico.Pneumonia is the most common nosocominal infection in intensive care units and mechanical ventilation is a significant factor associated to its development. The objective of this study was to describe the impact of the open and closed tracheal suction

  2. Conservação de rúcula minimamente processada produzida em campo aberto e cultivo protegido com agrotêxtil Conservation of minimally processed rocket produced under open field conditions and non woven polypropylene

    Directory of Open Access Journals (Sweden)

    Angela F Gonzalez

    2006-09-01

    Full Text Available Folhas de rúcula produzidas em campo aberto e sob cultivo protegido com agrotêxtil foram minimamente processadas, embaladas inteiras ou picadas em bandejas de poliestireno expandido e cobertas com filme de PVC de 14 micras. O delineamento adotado foi o inteiramente casualizado em esquema fatorial 2x2x2 (ambiente de cultivo, forma de preparo e refrigeração a 0(0C e 10(0C, com quatro repetições por tratamento, totalizando 32 bandejas. Os tratamentos foram armazenados a 0ºC e 10ºC por 10 dias, quando foram avaliadas as variáveis perda de massa (%; pH; sólidos solúveis; acidez titulável; cor e aparência. A conservação a 0ºC promoveu uma diminuição da perda de peso da rúcula minimamente processada. A utilização de folhas inteiras ou minimamente processadas foi significativa para sólidos solúveis sendo os maiores valores encontrados para as folhas inteiras. Para folhas picadas observou-se valores de acidez significativamente maiores para as produzidas sob ambiente natural. Independente da forma de preparo, a rúcula produzida em ambiente natural apresentou menor valor de pH. A cor e aparência da rúcula não foram influenciadas pelos tratamentos.Leaves of rocket salad produced under open field and non woven polypropylene were minimally processed and packed entire or pricked in polyestyrene trays covered with PVC film of 14 micras. The treatments were stored at 0(0C and 10(0C per 10 days, when the variables weight loss (%; pH; soluble solids; titratable acidity; colour and appearance were evaluated. The conservation under 0(0C promoted a reduction of weight loss on rocket salad minimally processed. Using entire or minimally processed leaves were significant for soluble solids the biggest values being found for entire leaves. For pricked leaves bigger values of acidity were observed for the produced ones under natural environment. Independent of the preparation form rocket salad produced under natural environment presented minor

  3. Analysis of optical properties in injection-molded and compression-molded optical lenses.

    Science.gov (United States)

    Wang, Chung Yen; Wang, Pei Jen

    2014-04-10

    Numerical mold-flow simulations and experimental measurements for injection-molded lenses have been investigated in form accuracy on a two-cavity mold with various process conditions. First, form profiles of the molded lenses have been measured together with the corresponding simulated mold-temperature distribution and displacement distribution of the lens in the z direction. A flow-through type layout of cooling channels has been devised for balance of mold-temperature distribution in mold cavities with various parametric distances for assessments in uniformity of temperature distribution. Finally, a compression-molding process is proposed for the post-process of birefringence relaxation as well as adequate form accuracy of lenses. In conclusion, optimization of process parameters to achieve good form accuracy in a multicavity mold with symmetric geometry but nonuniform cooling conditions is difficult. A good design of cooling channels plus optimized process conditions could provide uniform mold-temperature distribution so that molded lenses of good quality would be possible. Then, the profile deviation of lenses could be further compensated by profile geometry corrections. In conclusion, the post-compression-molding process could make birefringence-free plastic lenses with good form accuracy.

  4. Walter Benjamin: tempo de escola - tempo de agora. Prolegômenos para uma educação para dias feriados

    Directory of Open Access Journals (Sweden)

    Angela Medeiros Santi

    2012-03-01

    Full Text Available O propósito deste artigo é relacionar o pensamento de Walter Benjamin com o universo da educação e da infância, através da noção de tempo. A infância, para Benjamin, representa a suspensão do tempo vazio e linear, em favor de um tempo "artístico", um tempo de "dias feriados". A educação, em sua forma tradicional, trabalha com a formação da criança para o tempo linear, mas a infância, em sua potência revolucionária, é a suspensão do tempo como repetição mecânica, em favor de um tempo artístico, um "tempo de agora". Com base na constelação conceitual construída por Benjamin, pretendemos pensar uma agenda voltada para o futuro da educação, onde a escola deve, então, voltar seus investimentos para o tempo intensivo, o das surpresas, o dos cortes, o do inusitado. O artigo aponta para a educação pensada como experiência de outra temporalidade - aquela que se faz num encontro intensivo entre coisas e pessoas, livre e aberto para o inédito, aberto para o radical e para o agora.

  5. Minimization of sink mark defects in injection molding process ...

    African Journals Online (AJOL)

    Minimization of sink mark defects in injection molding process – Taguchi approach. ... plays a very important role in controlling the quality of the injection molded products. ... of injection molding variables on sink marks using Taguchi approach.

  6. Mold

    Science.gov (United States)

    ... all, may produce toxins or poisonous substances called mycotoxins that may cause effects in humans. Although there are many types of mycotoxins, aflatoxins are probably the best known and most ...

  7. Mechanical Properties of Injection Molded and Compression Molded Samples from Nature-Butadiene Rubber

    Directory of Open Access Journals (Sweden)

    Skrobak Adam

    2016-01-01

    Full Text Available The aim of this paper is to show what extent there is an impact on the mechanical properties (tensile strength and tear strength of a standardized testing sample made of rubber compound based on nature rubber and butadiene rubber produced by injection molding in comparison with a sample produced by classic preparation (cutting out a compression molded plate according to the standard ISO 23529. For realization of this study it was necessary to design and produce an injection mold for all types testing samples. Subsequently, mechanical properties such as the tensile stress-strain and tear strenght of compression molded samples and injection molded samples were studied, compared and discussed.

  8. Nonlinear Modeling of a High Precision Servo Injection Molding Machine Including Novel Molding Approach

    Institute of Scientific and Technical Information of China (English)

    何雪松; 王旭永; 冯正进; 章志新; 杨钦廉

    2003-01-01

    A nonlinear mathematical model of the injection molding process for electrohydraulic servo injection molding machine (IMM) is developed.It was found necessary to consider the characteristics of asymmetric cylinder for electrohydraulic servo IMM.The model is based on the dynamics of the machine including servo valve,asymmetric cylinder and screw,and the non-Newtonian flow behavior of polymer melt in injection molding is also considered.The performance of the model was evaluated based on novel approach of molding - injection and compress molding,and the results of simulation and experimental data demonstrate the effectiveness of the model.

  9. Mold Remediation in Schools and Commercial Buildings.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Radiation and Indoor Air.

    This document describes how to investigate and evaluate moisture and mold problems in educational facilities, and presents the key steps for implementing a remediation plan. A checklist is provided for conducting mold remediation efforts along with a resource list of helpful organizations and governmental agencies. Appendices contain a glossary,…

  10. Nanostructuring steel for injection molding tools

    DEFF Research Database (Denmark)

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders

    2014-01-01

    and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro-and nanostructuring the surface of the steel molds. We investigate...

  11. The Thermal Distortion of a Funnel Mold

    Science.gov (United States)

    Hibbeler, Lance C.; Thomas, Brian G.; Schimmel, Ronald C.; Abbel, Gert

    2012-10-01

    This article investigates the thermal distortion of a funnel mold for continuous casting of thin slabs and explores the implications on taper and solidification of the steel shell. The three-dimensional mold temperatures are calculated using shell-mold heat flux and cooling water profiles that were calibrated with plant measurements. The thermal stresses and distorted shape of the mold are calculated with a detailed finite-element model of a symmetric fourth of the entire mold and waterbox assembly, and they are validated with plant thermocouple data and measurements of the wear of the narrow-face copper mold plates. The narrow-face mold distorts into the typical parabolic arc, and the wide face distorts into a "W" shape owing to the large variation in bolt stiffnesses. The thermal expansion of the wide face works against the applied narrow-face taper and funnel effects, so the effect of thermal distortion must be considered to accurately predict the ideal mold taper.

  12. The use of IR thermography to show the mold and part temperature evolution in injection molding

    Science.gov (United States)

    Bula, Karol; Różański, Leszek; Marciniak-Podsadna, Lidia; Wróbel, Dawid

    2016-12-01

    This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm), and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity), SP3, SP4 (located in the 1 mm cavity) and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

  13. The use of IR thermography to show the mold and part temperature evolution in injection molding

    Directory of Open Access Journals (Sweden)

    Bula Karol

    2016-12-01

    Full Text Available This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm, and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity, SP3, SP4 (located in the 1 mm cavity and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

  14. Immune Response among Patients Exposed to Molds

    Directory of Open Access Journals (Sweden)

    Jordan N. Fink

    2009-12-01

    Full Text Available Macrocyclic trichothecenes, mycotoxins produced by Stachybotrys chartarum, have been implicated in adverse reactions in individuals exposed to mold-contaminated environments. Cellular and humoral immune responses and the presence of trichothecenes were evaluated in patients with mold-related health complaints. Patients underwent history, physical examination, skin prick/puncture tests with mold extracts, immunological evaluations and their sera were analyzed for trichothecenes. T-cell proliferation, macrocyclic trichothecenes, and mold specific IgG and IgA levels were not significantly different than controls; however 70% of the patients had positive skin tests to molds. Thus, IgE mediated or other non-immune mechanisms could be the cause of their symptoms.

  15. IC chip stress during plastic package molding

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, D.W.; Benson, D.A.; Peterson, D.W.; Sweet, J.N.

    1998-02-01

    Approximately 95% of the world`s integrated chips are packaged using a hot, high pressure transfer molding process. The stress created by the flow of silica powder loaded epoxy can displace the fine bonding wires and can even distort the metalization patterns under the protective chip passivation layer. In this study the authors developed a technique to measure the mechanical stress over the surface of an integrated circuit during the molding process. A CMOS test chip with 25 diffused resistor stress sensors was applied to a commercial lead frame. Both compression and shear stresses were measured at all 25 locations on the surface of the chip every 50 milliseconds during molding. These measurements have a fine time and stress resolution which should allow comparison with computer simulation of the molding process, thus allowing optimization of both the manufacturing process and mold geometry.

  16. Comparing suppository mold variability which can lead to dosage errors for suppositories prepared with the same or different molds.

    Science.gov (United States)

    Alexander, Kenneth S; Baki, Gabriella; Hart, Christine; Hejduk, Courtney; Chillas, Stephanie

    2013-01-01

    Suppository molds must be properly calibrated to ensure accurate dosing. There are often slight differences between molds and even in the cavities within a mold. A method is presented for the calibration of standard aluminum 6-, 12-, 50-, or 100-well suppository molds. Ten different molds were tested using water for volume calibration, and cocoa butter for standardization involving establishing the density factor. This method is shown to be straightforward and appropriate for calibrating suppository molds.

  17. Mold Simulator Study of the Initial Solidification of Molten Steel in Continuous Casting Mold: Part II. Effects of Mold Oscillation and Mold Level Fluctuation

    Science.gov (United States)

    Zhang, Haihui; Wang, Wanlin

    2016-04-01

    The surface quality of the continuous casting strands is closely related to the initial solidification of liquid steel in the vicinity of the mold meniscus, and thus the clear understanding of the behavior of molten steel initial solidification would be of great importance for the control of the quality of final slab. With the development of the mold simulator techniques, the complex interrelationship between the solidified shell surface profile, heat flux, shell thickness, mold level fluctuation, and the infiltrated slag film was well illustrated in our previous study. As the second part, this article investigated the effect of the mold oscillation frequency, stroke, and mold level fluctuation on the initial solidification of the molten steel through the conduction of five different experiments. Results suggested that in the case of the stable mold level, the oscillation marks (OMs) exhibit equally spaced horizon depressions on the shell surface, where the heat flux at the meniscus area raises rapidly during negative strip time (NST) period and the presence of each OMs on the shell surface is corresponding to a peak value of the heat flux variation rate. Otherwise, the shell surface is poorly defined by the existence of wave-type defects, such as ripples or deep depressions, and the heat flux variation is irregular during NST period. The rising of the mold level leads to the longer-pitch and deeper OMs formation; conversely, the falling of mold level introduces shorter-pitch and shallower OMs. With the increase of the mold oscillation frequency, the average value of the low-frequency heat flux at the meniscus increases; however, it decreases when the mold oscillation stroke increases. Additionally, the variation amplitude of the high-frequency temperature and the high-frequency heat flux decreases with the increase of the oscillation frequency and the reduction of the oscillation stroke.

  18. Restrição materna de polifenóis e dinâmica ductal fetal na gestação normal: um ensaio clínico aberto

    Directory of Open Access Journals (Sweden)

    Paulo Zielinsky

    2013-09-01

    Full Text Available FUNDAMENTOS: Recentemente demonstramos reversão da constrição ductal fetal após redução da ingesta materna de alimentos ricos em polifenóis (ARP, por sua ação inibidora da síntese das prostaglandinas. OBJETIVOS: Testar a hipótese de que fetos normais no 3º trimestre também melhoram a dinâmica ductal após restrição materna de polifenóis. MÉTODOS: Ensaio clínico aberto com 46 fetos com idade gestacional (IG > 28 semanas submetidos a dois estudos Dopplerecocardiográficos com intervalo de duas semanas, sendo os examinadores cegados para os hábitos alimentares maternos. Um questionário de frequência alimentar validado para esse objetivo foi aplicado e uma dieta com alimentos pobres em polifenóis (< 30 mg/100 mg foi orientada. Um grupo controle de 26 fetos no 3º trimestre foi submetido ao mesmo protocolo. Utilizou-se o teste-t para amostras independentes. RESULTADOS: A IG média foi 33 ± 2 semanas. A média do consumo materno diário de polifenóis (CMDP foi 1277 mg, caindo para 126 mg após orientação (p = 0,0001. Ocorreu diminuição significativa nas Velocidades Ductais Sistólica (VSD e Diastólica (VDD e na relação dos diâmetros ventriculares (VD/VE, assim como aumento do índice de pulsatilidade (IP [VSD = 1,2 ± 0,4 m/s (0,7-1,6 para 0,9 ± 0,3 m/s (0,6-1,3 (p = 0,018;VDD = 0,21 ± 0,09 m/s (0,15-0,32 para 0,18 ± 0,06 m/s (0,11-0,25 (p = 0,016; relação VD/VE = 1,3 ± 0,2 (0,9-1,4 para 1,1 ± 0,2 (0,8 - 1,3 (p = 0,004; IP do ducto = 2,2 ± 0,03 (2,0-2,7 para 2,4 ± 0,4 (2,2-2,9 (p = 0,04]. A IG média dos controles foi de 32 ± 4 semanas, não ocorrendo diferenças significativas no CMDP, nas velocidades ductais, no IP do ducto e na relação VD/VE. CONCLUSÃO: A restrição da ingesta de alimentos ricos em polifenóis no 3º trimestre por duas semanas melhora a dinâmica do fluxo no ducto arterioso fetal e as dimensões do VD.

  19. Medical diagnostics for indoor mold exposure.

    Science.gov (United States)

    Hurraß, Julia; Heinzow, Birger; Aurbach, Ute; Bergmann, Karl-Christian; Bufe, Albrecht; Buzina, Walter; Cornely, Oliver A; Engelhart, Steffen; Fischer, Guido; Gabrio, Thomas; Heinz, Werner; Herr, Caroline E W; Kleine-Tebbe, Jörg; Klimek, Ludger; Köberle, Martin; Lichtnecker, Herbert; Lob-Corzilius, Thomas; Merget, Rolf; Mülleneisen, Norbert; Nowak, Dennis; Rabe, Uta; Raulf, Monika; Seidl, Hans Peter; Steiß, Jens-Oliver; Szewszyk, Regine; Thomas, Peter; Valtanen, Kerttu; Wiesmüller, Gerhard A

    2017-04-01

    In April 2016, the German Society of Hygiene, Environmental Medicine and Preventative Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin (GHUP)) together with other scientific medical societies, German and Austrian medical societies, physician unions and experts has provided an AWMF (Association of the Scientific Medical Societies) guideline 'Medical diagnostics for indoor mold exposure'. This guideline shall help physicians to advise and treat patients exposed indoors to mold. Indoor mold growth is a potential health risk, even without a quantitative and/or causal association between the occurrence of individual mold species and health effects. Apart from the allergic bronchopulmonary aspergillosis (ABPA) and the mycoses caused by mold, there is only sufficient evidence for the following associations between moisture/mold damages and different health effects: Allergic respiratory diseases, asthma (manifestation, progression, exacerbation), allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. In comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low. Recent studies show a prevalence of sensitization of 3-10% in the total population of Europe. The evidence for associations to mucous membrane irritation and atopic eczema (manifestation, progression, exacerbation) is classified as limited or suspected. Inadequate or insufficient evidence for an association is given for COPD, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis, and cancer. The risk of infections from indoor molds is low for healthy individuals. Only molds that are capable to form toxins can cause intoxications. The environmental and growth conditions and especially the substrate determine whether toxin formation occurs, but indoor air concentrations are always very low. In the case of indoor moisture/mold damages, everyone can be affected by odor effects and

  20. Thermoplastic blow molding of metals

    Directory of Open Access Journals (Sweden)

    Jan Schroers

    2011-01-01

    Full Text Available While plastics have revolutionized industrial design due to their versatile processability, their relatively low strength has hampered their use in structural components. On the other hand, while metals are the basis for strong structural components, the geometries into which they can be processed are rather limited. The “ideal” material would offer a desirable combination of superior structural properties and the ability to be precision (net shaped into complex geometries. Here we show that bulk metallic glasses (BMGs, which have superior mechanical properties, can be blow molded like plastics. The key to the enhanced processability of BMG formers is their amenability to thermoplastic forming. This allows complex BMG structures, some of which cannot be produced using any other metal process, to be net shaped precisely.

  1. Challenges in mold manufacturing for high precision molded diffractive optical elements

    Science.gov (United States)

    Pongs, Guido; Bresseler, Bernd; Schweizer, Klaus; Bergs, Thomas

    2016-09-01

    Isothermal precision glass molding of imaging optics is the key technology for mass production of precise optical elements. Especially for numerous consumer applications (e.g. digital cameras, smart phones, …), high precision glass molding is applied for the manufacturing of aspherical lenses. The usage of diffractive optical elements (DOEs) can help to further reduce the number of lenses in the optical systems which will lead to a reduced weight of hand-held optical devices. But today the application of molded glass DOEs is limited due to the technological challenges in structuring the mold surfaces. Depending on the application submicrometer structures are required on the mold surface. Furthermore these structures have to be replicated very precisely to the glass lens surface. Especially the micro structuring of hard and brittle mold materials such as Tungsten Carbide is very difficult and not established. Thus a multitude of innovative approaches using diffractive optical elements cannot be realized. Aixtooling has investigated in different mold materials and different suitable machining technologies for the micro- and sub-micrometer structuring of mold surfaces. The focus of the work lays on ultra-precision grinding to generate the diffractive pattern on the mold surfaces. This paper presents the latest achievements in diffractive structuring of Tungsten Carbide mold surfaces by ultra-precision grinding.

  2. Study on Effects of Mold Temperature on the Injection Molded Article

    Directory of Open Access Journals (Sweden)

    Han J.-H.

    2017-06-01

    Full Text Available This is a study of the effects of temperature of injection mold on the injection molded article. By supplying water of the proper temperature in the cooling line of mold in the cooling process, the mold was the appropriate temperature, and the deformation of the injection molded article was examined according to the mold temperature. In this study, we conducted simulation analysis and experiments, and the results were analyzed. The minimum deformation of the injection molded article model obtained by supplying 50°C water in the cooling line is 0.003 mm, and the maximum deformation was 0.813 mm. Injection molded article models obtained by supplying 20°C water were found to be a minimum of 0.002 mm, with deformation of up to 0.761 mm. When comparing both conditions, the error rate of injection molded article obtained by supplying 20°C water in the mold cooling line was lower by about 0.18%.

  3. Characterization of fiberglass-filled diallyl phthalate plastic molding resins and molded parts

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.B.; Glaub, J.E.; Bonekowski, N.R.; Gillham, P.D.

    1980-12-01

    Characterization of diallyl phthalate (DAP) molding resins was undertaken by differential scanning calorimetry (DSC) and by combined size exclusion chromatography (SEC)/low angle laser light scattering (LALLS) in order to better predict moldability and storage life limits. Completeness of cure of molded parts, before and after any post-curing, was also determined by thermal analysis. Molecular weights and molecular weight distributions of the DAP molding resins by SEC/LALLS indicated that the better molding resins have lower M/sub w//M/sub n/ ratios. Association effects were observed, which could not be overcome by solvent modification alone. Determination of DAP molding resin heats of reaction by DSC indicated a linear relation between ..delta..H/sub R/ and weight percent filler for the good molding resins. DSC analyses of molded DAP parts showed that 95% cure was achieved in some as-molded parts, with a post-cure temperature of 165/sup 0/C being required to complete the cure to 100%. Thickness of the parts was a factor, with the thicker parts being 100% cured as molded. The glass transition temperature (T/sub g/) of the molded parts increased as cure was completed, to approx. 160 to 165/sup 0/C maximum. These results are consistent with a model of thermoset resin curing behavior which states that 100% cure can be achieved only if a post-curing operation is conducted above the T/sub g infinity/ (T/sub g/ at complete cure) of the polymer.

  4. Cooling simulation of plastic injection molding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Analyses the cooling of mold and plastic part during injectionmolding and the continued cooling of plastic part after being ejected from mold using the heat transfer theory and Boundary Element Method (BEM) to predict the temperature distribution in both mold and plastic part,and presents the experiments carried out with plates of ABS (Acrylonitrile-Butadiene-Styrene) to verify the validity of the cooling analysis software used to simulate the temperature distribution in ABS plate parts, and concludes that the analysis software agree qualitatively well with actual experimental findings.

  5. Evaluation of stability for monolayer injection molding tools coating

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.

    2012-01-01

    We tested and characterized molecular coating of Aluminium and Nickel prototype molds and mold inserts for polymer replication via injection molding (IM). X-Ray photoelectron spectroscopy (XPS) data, sessile drop contact angles with multiple fluids, surface energy and roughness data have been...... and especially suitable for rapid prototyping and mold geometry testing....

  6. Mechanical Properties of Injection Molded and Compression Molded Samples from Nature-Butadiene Rubber

    OpenAIRE

    Skrobak Adam; Janoštík Václav; Stanek Michal; Manas David; Ovsik Martin; Senkerik Vojtech; Reznicek Martin

    2016-01-01

    The aim of this paper is to show what extent there is an impact on the mechanical properties (tensile strength and tear strength) of a standardized testing sample made of rubber compound based on nature rubber and butadiene rubber produced by injection molding in comparison with a sample produced by classic preparation (cutting out a compression molded plate) according to the standard ISO 23529. For realization of this study it was necessary to design and produce an injection mold for all typ...

  7. Solving depressions formed during production of plastic molding

    Directory of Open Access Journals (Sweden)

    J. Dobránsky

    2015-07-01

    Full Text Available This article deals with improvement of design properties of molded plastic parts. It can be achieved by modifying construction of metal injection mold and optimization of parameters in injection process. The subject of our examination was depressions formed on molded plastic parts which are inacceptable in the process of approval. The problem which has arisen was solved in two phases. The first phase consisted in alteration of injection mold design – enlargement of injection molding gate. In the second phase, we have changed the location of injection molding gate. After performing constructional modifications, new molded plastic parts were manufactured and assessed.

  8. Assessment of mold concentrations in Singapore shopping centers using mold-specific quantitative PCR (MSQPCR) analysis.

    Science.gov (United States)

    Yap, Jennifer; Toh, Zhen Ann; Goh, Vivien; Ng, Lee Chen; Vesper, Stephen

    2009-09-01

    Molds can pose a human health threat and may amplify in buildings in humid climates. The objective of this study was to evaluate the mold growth in Singapore shopping centers based on the collection of 40 dust samples from 15 shopping centers, including one with a history of water damage. The dust was analyzed by a DNA-based technology called mold-specific quantitative PCR (MSQPCR). In a water-damaged shopping center, most of the 26 water-damage indicator species were detected at some concentration and many were much more abundant than the average in the shopping centers. MSQPCR is a useful method for quantifying indoor molds in tropical climates.

  9. A new insight into foaming mechanisms in injection molding via a novel visualization mold

    Directory of Open Access Journals (Sweden)

    V. Shaayegan

    2016-06-01

    Full Text Available The complex mechanisms of bubble nucleation and dynamics in foam injection molding have not been uncovered despite many previous efforts due to the non-steady stop-and-flow nature of injection molding and the non-uniform temperature and pressure distributions in the mold. To this end, a new visualization mold was designed and manufactured for the direct observation of bubble nucleation and growth/collapse in foam injection molding. A reflective prism was incorporated into the stationary part of the injection mold with which the nucleation and growth behaviors of bubbles were successfully observed. The mechanisms of bubble nucleation in low- and high-pressure foam injection molding, with and without the application of gas-counter pressure, was investigated. We identified how the inherently non-uniform cell structure is developed in low-pressure foam injection molding with gate-nucleated bubbles, and when and how cell nucleation occurs in high-pressure foam injection molding with a more uniform pressure drop.

  10. The effect of mold surface topography on plastic parat in-process shrinkage in injection molding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2003-01-01

    An experimental study of the effect of mold surface roughness on in-process in-flow linear part shrinkage in injection molding has been carried out. The investigation is based on an experimental two-cavity tool, where the cavities have different surface topographies, but are otherwise identical....... The study has been carried out for typical commercial polystyrene and polypropylene grades. The relationship between mold surface topography and linear shrinkage has been investigated with an experimental two-cavity mold producing simple rectangular parts with the nominal dimensions 1 x 25 x 50 mm (see...

  11. Molds on Food: Are They Dangerous?

    Science.gov (United States)

    ... food was stored. Check nearby items the moldy food might have touched. Mold spreads quickly in fruits and vegetables. See the attached chart "Moldy Food: When to Use, When to Discard." FOOD HANDLING ...

  12. Injection molded optical backplane for broadcast architecture

    Science.gov (United States)

    Rosenberg, Paul; Mathai, Sagi; Sorin, Wayne V.; McLaren, Moray; Straznicky, Joseph; Panotopoulos, Georgios; Warren, David; Morris, Terry; Tan, Michael R. T.

    2012-01-01

    A low cost, blind mate, injection molded optical backplane is presented. The optical backplane is comprised of 12 channel optical broadcast buses, operating at 10Gbps/channel with six blindmate optical output ports spaced 1U apart.

  13. Three-Dimensional Pneumatic Molding of Veneers

    Directory of Open Access Journals (Sweden)

    Milan Gaff

    2014-07-01

    Full Text Available The goal of this paper is to introduce a new testing method suitable for the evaluation of the three-dimensional (3-D moldability of veneers and to use this method to test the impact of specific factors on the 3-D pneumatic molding process. The tested factors included veneer moisture content, wood species, shape of test piece, and fixing method on the maximum wood deflection. Veneers were molded using compressed air on equipment designed by our group for the sole purpose of this experiment. The results indicated that the monitored factors had an effect on deflection during the 3-D molding process. The results of this investigation extend the state-of-the-art knowledge regarding this technology and indicate the possibility of utilizing this innovative testing method for 3-D molded veneers.

  14. Secondary metabolites of slime molds (myxomycetes).

    Science.gov (United States)

    Dembitsky, Valery M; Rezanka, Tomás; Spízek, Jaroslav; Hanus, Lumír O

    2005-04-01

    The compounds reported from the slime molds (myxomycetes) species are described. Almost 100 natural compounds including their chemical structures and biological activities are described in this review article. Only metabolites with a well-defined structure are included.

  15. Rozen : steeds meer bekend over Black Mold

    NARCIS (Netherlands)

    Smits, A.P.; Kohrman, E.

    2009-01-01

    Onderzoek naar Black Mold heeft al veel informatie opgeleverd over de verspreiding, bestrijding en ontwikkeling van de oculatieschimmel. In dit artikel de nieuwste resultaten van PPO en Cultus Agro Advies

  16. Facts about Stachybotrys chartarum and Other Molds

    Science.gov (United States)

    ... Organization issued additional guidance, the WHO Guidelines for Indoor Air Quality: Dampness and Mould [PDF - 2.52 MB] . Other ... reliable sampling for mold can be expensive, and standards for judging what is and what is not ...

  17. Custom molded thermal MRg-FUS phantom

    Science.gov (United States)

    Eames, Matthew D. C.; Snell, John W.; Hananel, Arik; Kassell, Neal F.

    2012-11-01

    This article describes a method for creating custom-molded thermal phantoms for use with MR-guided focused ultrasound systems. The method is defined here for intracranial applications, though it may be modified for other anatomical targets.

  18. Additive Manufacturing of Wind Turbine Molds

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Richardson, Bradley [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lloyd, Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Love, Lonnie [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nolet, Stephen [TPI Composites, Scottsdale, AZ (United States); Hannan, James [TPI Composites, Scottsdale, AZ (United States)

    2017-07-01

    The objective of this project was to explore the utility of Big Area Additive Manufacturing (BAAM) for low cost manufacturing of wind turbine molds. Engineers at Oak Ridge National Laboratory (ORNL) and TPI Composites (TPI) collaborated to design and manufacture a printed mold that can be used for resin infusion of wind turbine components. Specific focus was on required material properties (operating temperatures and pressures, coefficient of thermal expansion (CTE), thermal conductivity), surface finish (accuracy and coatings) and system integration (integrated vacuum ports, and heating element). The project began with a simple proof of principle components, targeting surface coatings and material properties for printing a small section (approximately 4’ x 4’ x 2’) of a mold. Next, the second phase scaled up and integrated with the objective of capturing all of the necessary components (integrated heating to accelerate cure time, and vacuum, sealing) for resin infusion on a mold of significant size (8’ x 20’ x 6’).

  19. National Allergy Bureau Pollen and Mold Report

    Science.gov (United States)

    ... the Expert Search Search AAAAI National Allergy Bureau Pollen and Mold Report Date: April 11, 2017 Location: ... 11, 2017 Click Here to View Most Recent Pollen and Spore Levels (04/10/2017) If you ...

  20. 21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION..., sheep's milk blue-mold, and blue-mold cheese from sheep's milk. (a) Description. (1) Roquefort...

  1. Die Casting Mold Design for Aluminum Alloy Shell of Instrument

    Directory of Open Access Journals (Sweden)

    Li Yuanyuan

    2015-01-01

    Full Text Available This paper is about die casting mold design for aluminum alloy shell of instrument. Three-dimensional model of the casting and mold are designed by using Pro/Engineer and AutoCad which can analyze forming quality. Digital design and theoretical calculation can greatly shorten product development cycle and mold design cycle, improve the accuracy of product design and mold design, and reduce the cost of mold design.

  2. Integrated mold/surface-micromachining process

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Montague, S.; Sniegowski, J.J.; Hetherington, D.L.

    1996-03-01

    We detail a new monolithically integrated silicon mold/surface-micromachining process which makes possible the fabrication of stiff, high-aspect-ratio micromachined structures integrated with finely detailed, compliant structures. An important example, which we use here as our process demonstration vehicle, is that of an accelerometer with a large proof mass and compliant suspension. The proof mass is formed by etching a mold into the silicon substrate, lining the mold with oxide, filling it with mechanical polysilicon, and then planarizing back to the level of the substrate. The resulting molded structure is recessed into the substrate, forming a planar surface ideal for subsequent processing. We then add surface-micromachined springs and sense contacts. The principal advantage of this new monolithically integrated mold/surface-micromachining process is that it decouples the design of the different sections of the device: In the case of a sensitive accelerometer, it allows us to optimize independently the proof mass, which needs to be as large, stiff, and heavy as possible, and the suspension, which needs to be as delicate and compliant as possible. The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. We anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems.

  3. EFFECTIVENESS OF CELLULAR INJECTION MOLDING PROCESS

    Directory of Open Access Journals (Sweden)

    Tomasz Garbacz

    2013-06-01

    Full Text Available In a study of cellular injection, molding process uses polyvinylchloride PVC. Polymers modified with introducing blowing agents into them in the Laboratory of the Department of Technologies and Materiase of Technical University of Kosice. For technological reasons, blowing agents have a form of granules. In the experiment, the content of the blowing agent (0–2,0 % by mass fed into the processed polymer was adopted as a variable factor. In the studies presented in the article, the chemical blowing agents occurring in the granulated form with a diameter of 1.2 to 1.4 mm were used. The view of the technological line for cellular injection molding and injection mold cavity with injection moldings are shown in Figure 1. The results of the determination of selected properties of injection molded parts for various polymeric materials, obtained with different content of blowing agents, are shown in Figures 4-7. Microscopic examination of cross-sectional structure of the moldings were obtained using the author's position image analysis of porous structure. Based on analysis of photographs taken (Figures 7, 8, 9 it was found that the coating containing 1.0% of blowing agents is a clearly visible solid outer layer and uniform distribution of pores and their sizes are similar.

  4. Análise do índice de especulação de valor agregado para empresas de capital aberto negociadas na Bovespa

    Directory of Open Access Journals (Sweden)

    Wesley Vieira da Silva

    2008-12-01

    Full Text Available This study aims at demonstrating economic sectors’ life cycle of different area in Sao Paulo Stock Exchange (Bovespa. Therefore, data from 30 companies were analysed, selecting three companies of each area on stock exchange. Quarterly financial statements data were used for analyses regarding to the period from December 2000 to March 2006. For the development of this research the Speculation Index of Value Added (IEVA was applied, considering the relation to CAPM – Capital Asset Pricing Model. The results applied to each economic sector IEVA evidences differences between them, as well influences in Bovespa’s performance results in the period of the research. Besides that, IEVA contributes to the understanding of how companies’ economic value is composed. The results demonstrate that each sector with well established companies is heterogeneity in its performance; even though, it is superior to the market expectation. This information allows quantify investments’ risks in the studied sectors.

  5. A Contribuição da Governança Corporativa para o Desempenho das Empresas Brasileiras de Capital Aberto

    Directory of Open Access Journals (Sweden)

    Rodrigo Santos de Melo

    2013-03-01

    Full Text Available The heterogeneity of business performance has been the subject of great concern for entrepreneurs and researchers of Social Sciences. There are numerous approaches and methodologies for the investigation of this subject, producing results on which there is no consensus among the most relevant authors. Regarding the approaches, some of the differences can be attributed to the researchers' preference for one of the competing explanatory theories of this phenomenon – the Industrial Organization, the Resource-based View (RBV, the Dynamic Skills Theory and the Theory of Market Processes. The authors of the Theory of Dynamic Skills consider leverage and regeneration of resources and capabilities as essential factors for the formation of competitive advantage, and highlight the crucial role of strategic management in this field. These new ideas stimulated the analysis of the influence of firm factors performance, among which the contribution of managerial aspects, the line of research chosen for this article, which aims to investigate the contribution of Corporate Governance in the performance of Brazilian publicly traded companies registered at BM&FBOVESPA. The methodology used is the MANOVA, and the results confirm that the Corporate Governance constitutes a relevant explanatory factor in business performance.

  6. Fast Mold Temperature Evolution on Micro Features Replication Quality during Injection Molding

    DEFF Research Database (Denmark)

    Liparoti, S.; Calaon, Matteo; Speranza, V.;

    2016-01-01

    lithography and subsequent nickel electroplating. The mold temperature was controlled by a thin heating device (composed by polyimide as insulating layer and polyimide carbon black loaded aselectrical conductive layer) able to increase the temperature on mold surface in a few seconds (40°C/s) by Joule effect...

  7. Development of sheet molding compound solar collectors with molded-in silvered glass reflective surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Champion, R. L.; Allred, R. E.

    1980-12-01

    The reflecting concentrator of a parabolic trough solar collector system comprises approximately 40% of initial system cost. The parabolic concentrator structure is also the most influential component in determining overall system efficiency. Parabolic test moldings have been fabricated from a general purpose sheet molding compound with flat chemically strengthened glass, flat annealed glass, and thermally formed glass. The test panel configuration was a 1.22 m x 0.61 m, 45/sup 0/ rim angle (0.762 m focal length) parabola. Attempts to mold with annealed sheet glass (1 mm thick) and thermally formed glass (1.25 mm thick) were unsuccessful; only the chemically strengthened glass (1.25 mm thick) was strong enough to survive molding pressures. Because of the mismatch in thermal expansion between glass and sheet molding compound, the as-molded panels contained a sizeable residual stress. The results are given of dimensional changes taking place in the panels under accelerated thermal cycling and outdoor aging conditions; these results are compared to an analytical model of the laminate. In addition, the sheet molding compound has been examined for thermomechanical properties and flow behavior in the rib sections. Results indicated that lowering the thermal expansion coefficient of the sheet molding compound through material modifications would produce a more stable structure.

  8. Periódicos da Ciência da Informação em acesso aberto: uma análise dos títulos listados no DOAJ e indexados na Scopus │ Open access journals in information Science: an analysis of the titles listed in DOAJ and indexed in Scopus

    Directory of Open Access Journals (Sweden)

    Patricia da Silva Neubert

    2012-12-01

    Full Text Available Resumo Analisa os periódicos em acesso aberto da área de ciência da informação listados no DOAJ e indexados na Scopus. Os objetivos específicos são: a descrever os periódicos científicos da área de ciência da informação em acesso aberto, b registrar a visibilidade dos periódicos e c verificar o uso de recursos web. Os periódicos da área de ciência da informação são publicações criadas a partir de 1990 (93,33% sem patrocínio, publicados na América e Europa (80%, em inglês (73,33%, e mantidos por universidades, institutos de fomento a pesquisa e por associações (86,67%. Possuem Ìndice H com média 8,47, e 40% dos títulos são classificados no Qualis. Quanto aos recursos web, 33,33% possui canal de notícias, 26,66% feeds RSS, 13,33% blogs e 6,67% página no Facebook. Em relação aos recursos para compartilhamento pelo leitor, os 13,33% cuja plataforma é o Scielo disponibilizam recursos para compartilhamento por e-mail e por widget. Palavras-chave periódicos científicos; Ciência da Informação; acesso aberto; bases de dados; visibilidade dos periódicos; recursos web Abstract Analysis of open access journals in the field of library and information science listed in DOAJ and indexed in Scopus. The specific objectives are: a to describe the scientific journals in the field of information science open access, b recording the visibility of the journals and c to check the usage of web resources by the journals. The information science open access publications are mostly created starting from 1990 (93.33%, unsponsored, published in North America and Europe (80%, in English (73.33% , and maintained by universities, institutes and research funding agencies and associations (86.67%. The H index has an average of 8.47, and only 40% of the titles are classified in Qualis. The actions associated with web: 33.33% have news, RSS feeds are 26.66%, 13.33% blogs and 6.67% have a page in Facebook. Regarding resources for content

  9. Study On The External Gas-Assisted Mold Temperature Control For Thin Wall Injection Molding

    Directory of Open Access Journals (Sweden)

    ThanhTrung Do

    2017-03-01

    Full Text Available Dynamic mold surface temperature control (DMTC has many advantages in micro-injection molding as well as thin-wall molding product. In this paper, DMTC will be applied for the thin-wall molding part with the observation of the weldline appearance and the weldline strength. The heating step of DMTC will be achieved by the hot air flow directly to the weldline area. The results show that the heating rate could be reached to 4.5C/s, which could raising the mold surface from 30C to over 120C within 15 s. The melt filling was operated with high temperature at the weldline area; therefore, the weldline appearance was eliminated. In addition, the weldline strength was also improved. The results show that the thinner part had the higher strength of the weldline

  10. Effects of mold geometry on fiber orientation of powder injection molded metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Aslam, Muhammad, E-mail: klaira73@gmail.com; Altaf, Khurram, E-mail: khurram.altaf@petronas.com.my; Shirazi, Irfan, E-mail: irfanshirazi@hotmail.com [Mechanical Engineering Universiti Teknologi PETRONAS Malaysia (Malaysia)

    2015-07-22

    Fiber orientations in metal matrix composites have significant effect on improving tensile properties. Control of fiber orientations in metal injection molded metal composites is a difficult task. In this study, two mold cavities of dimensions 6x6x90 mm and 10x20x180 mm were used for comparison of fiber orientation in injection molded metal composites test parts. In both mold cavities, convergent and divergent flows were developed by modifying the sprue dimensions. Scanning electron microscope (SEM) was used to examine the fiber orientations within the test samples. The results showed highly aligned fiber in injection molded test bars developed from the convergent melt flow. Random orientation of fibers was noted in the composites test bars produced from divergent melt flow.

  11. Injection molding simulation with variothermal mold temperature control of highly filled polyphenylene sulfide

    Science.gov (United States)

    Birkholz, A.; Tschiersky, M.; Wortberg, J.

    2015-05-01

    For the installation of a fuel cell stack to convert chemical energy into electricity it is common to apply bipolar plates to separate and distribute reaction gases and cooling agents. For reducing manufacturing costs of bipolar plates a fully automated injection molding process is examined. The high performance thermoplastic matrix material, polyphenylene sulfide (PPS), defies against the chemical setting and the operation temperature up to 200 °C. To adjust also high electrical and thermal conductivity, PPS is highly filled with various carbon fillers up to an amount of 65 percentage by volume. In the first step two different structural plates (one-sided) with three different gate heights and molds are designed according to the characteristics of a bipolar plate. To cope with the approach that this plate should be producible on standard injection molding machines with variothermal mold temperature control, injection molding simulation is used. Additionally, the simulation should allow to formulate a quality prediction model, which is transferrable to bipolar plates. Obviously, the basis for a precise simulation output is an accurate description of the material properties and behavior of the highly filled compound. This, the design of the structural plate and mold and the optimization via simulation is presented, as well. The influence of the injection molding process parameters, e.g. injection time, cycle times, packing pressure, mold temperature, and melt temperature on the form filling have been simulated to determine optimal process conditions. With the aid of the simulation and the variothermal mold temperature control it was possible to reduce the required melt temperature below the decomposition temperature of PPS. Thereby, hazardous decomposition products as hydrogen sulfide are obviated. Thus, the health of the processor, the longevity of the injection molding machine as well as the material and product properties can be protected.

  12. Environmental impact estimation of mold making process

    Science.gov (United States)

    Kong, Daeyoung

    Increasing concern of environmental sustainability regarding depletion of natural resources and resulting negative environmental impact has triggered various movements to address these issues. Various regulations about product life cycle have been made and applied to industries. As a result, how to evaluate the environmental impact and how to improve current technologies has become an important issue to product developers. Molds and dies are very generally used manufacturing tools and indispensible parts to the production of many products. However, evaluating environmental impact in mold and die manufacturing is not well understood and not much accepted yet. The objective of this thesis is to provide an effective and straightforward way of environmental analysis for mold and die manufacturing practice. For this, current limitations of existing tools were identified. While conventional life cycle assessment tools provide a lot of life cycle inventories, reliable data is not sufficient for the mold and die manufacturer. Even with comprehensive data input, current LCA tools only provide another comprehensive result which is not directly applicable to problem solving. These issues are critical especially to the mold and die manufacturer with limited resource and time. This thesis addresses the issues based on understanding the needs of mold and die manufacturers. Computer aided manufacturing (CAM) is the most frequently used software tool and includes most manufacturing information including the process definition and sometimes geometric modeling. Another important usage of CAM software tools is problem identification by process simulation. Under the virtual environment, possible problems are detected and solved. Environmental impact can be handled in the same manner. To manufacture molds and dies with minimizing the associated environmental impact, possible environmental impact sources must be minimized before the execution in the virtual environment. Molds and dies

  13. Injection molding of high aspect ratio sub-100 nm nanostructures

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels B

    2013-01-01

    with FDTS. Reduced adhesion forces are consistent with lowered friction that reduces the risk of fracturing the nanoscopic pillars during demolding. Optimized mold surface chemistry and associated injection molding conditions permitted the fabrication of square arrays of 40 nm wide and 107 nm high (aspect......We have explored the use of mold coatings and optimized processing conditions to injection mold high aspect ratio nanostructures (height-to-width >1) in cyclic olefin copolymer (COC). Optimizing the molding parameters on uncoated nickel molds resulted in slight improvements in replication quality...

  14. Aplicabilidade do termo antocrono para representar a velocidade de abertura de flores em inflorescência

    Directory of Open Access Journals (Sweden)

    Natalia Teixeira Schwab

    2014-09-01

    Full Text Available O objetivo deste trabalho foi propor um termo para representar o intervalo de tempo de abertura entre flores sucessivas em inflorescências, e verificar a aplicabilidade deste termo a gladíolo de corte. O termo foi construído pela junção dos radicais gregos anto- (antos = flor e crono- (cronos = tempo, para corresponder ao tempo necessário para a abertura de flores sucessivas em ramos florais (inflorescências, tendo-se como unidade o tempo por flor. Para testar o conceito e a aplicabilidade do termo, dados do número acumulado de floretes abertos em espigas de gladíolo foram coletados em dois experimentos de campo, em Santa Maria, RS, de agosto de 2011 a novembro de 2013. Para cada parcela de seis plantas, realizou-se uma regressão linear simples entre o número acumulado de floretes abertos na haste floral e os dias após a emergência das plantas. O termo foi denominado "antocrono" e, em gladíolo, foi estimado como sendo o inverso do coeficiente angular da regressão linear, com a unidade dias por florete. O antocrono em gladíolo depende da cultivar e decresce com o aumento da temperatura do ar, durante o período de florescimento da espiga.

  15. Gating of Permanent Molds for Aluminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-01-01

    This report summarizes a two-year project, DE-FC07-011D13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. Other studies have been conducted using water flow and behavior of liquid aluminum in sand mold using real time photography. This investigation utilizes graphite molds transparent to X-Rays making it possible to observe the flow pattern through a number of vertically oriented grating systems. These have included systems that are choked at the base of a rounded vertical sprue and vertical gating systems with a variety of different ingates into the bottom of a mold cavity. These systems have also been changed to include gating systems with vertical and horizontal gate configurations. Several conclusions can be derived from this study. A sprue-well, as designed in these experiments, does not eliminate the vena contracta. Because of the swirling at the sprue-base, the circulating metal begins to push the entering metal stream toward the open runner mitigating the intended effect of the sprue-well. Improved designs of

  16. Future Specialist’s Professional Position Molding

    Directory of Open Access Journals (Sweden)

    Irina A. Levitskaya

    2013-01-01

    Full Text Available The search of conditions for future specialist’s professional position molding is crucial nowadays. This article discloses the features of “position” notion essence in the context of professional self-determination, analyses the problems of future specialist’s professional development in terms of topical social and professional objectives solution, considers debatable issues of professional development as an integral continuous process of future specialist’s personality formation. The stages of personality professional molding are elaborated. The author determines the relation of professional position with different types of positions (social, personal, role-based. It is mentioned that professional position is determined by professional attitudes and characterizes person’s system of stable value relations towards future professional activities. The relation between the professional position molding and the professional orientation, determining person’s peculiarly experienced selective attitude towards reality, influencing his/her activity is emphasized

  17. Modelling and monitoring in injection molding

    DEFF Research Database (Denmark)

    Thyregod, Peter

    2001-01-01

    -conforning unit is only expected very rarely during sampling, a moving sum chart and a CUSUM chart are equivalent. Finally, the correlation structure of 21 process variables has been studied prior to monitoring the process. Is is illustrated how the process can be analysed with multivariate techniques......This thesis is concerned with the application of statistical methods in quality improvement of injection molded parts. The methods described are illustrated with data from the manufacturing of parts for a medical device. The emphasis has been on the variation between cavities in multi-cavity molds...... taken within the same machine set-point did not cause great variation compared to the two preceding sources of variation. A simple graphical approach is suggested for finding patterns in the cavity differences. Applying this method to data from a 16 cavity mold, a clear connection was found between...

  18. High rate fabrication of compression molded components

    Energy Technology Data Exchange (ETDEWEB)

    Matsen, Marc R.; Negley, Mark A.; Dykstra, William C.; Smith, Glen L.; Miller, Robert J.

    2016-04-19

    A method for fabricating a thermoplastic composite component comprises inductively heating a thermoplastic pre-form with a first induction coil by inducing current to flow in susceptor wires disposed throughout the pre-form, inductively heating smart susceptors in a molding tool to a leveling temperature with a second induction coil by applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors, shaping the magnetic flux that passes through surfaces of the smart susceptors to flow substantially parallel to a molding surface of the smart susceptors, placing the heated pre-form between the heated smart susceptors; and applying molding pressure to the pre-form to form the composite component.

  19. Injection molded self-cleaning surfaces

    DEFF Research Database (Denmark)

    Søgaard, Emil

    This PhD thesis concerns the development of superhydrophobic surfaces fabricated by injection molding. Today, injection molding is the prevalent production method for consumer plastic products. However, concerns regarding the environmental impact of a plastic production are increasing, especially...... that are superhydrophobic based on topography rather than chemical compounds. Therefore, a novel method for fabricating superhydrophobic polymer surfaces with excellent water-repellant properties is developed. The method is based on microstructure fabrication and superposed nanostructures on silicon wafers. The nano......° for structured surfaces with a drop roll-off angle of less than 2°. Thereby, it is shown that an extremely water repellant surface can be injection molded directly with clear perspectives for more environmental and healthier plastic consumer products....

  20. Single gate optimization for plastic injection mold

    Institute of Scientific and Technical Information of China (English)

    LI Ji-quan; LI De-qun; GUO Zhi-ying; LV Hai-yuan

    2007-01-01

    This paper deals with a methodology for single gate location optimization for plastic injection mold. The objective of the gate optimization is to minimize the warpage of injection molded parts, because warpage is a crucial quality issue for most injection molded parts while it is influenced greatly by the gate location. Feature warpage is defined as the ratio of maximum displacement on the feature surface to the projected length of the feature surface to describe part warpage. The optimization is combined with the numerical simulation technology to find the optimal gate location, in which the simulated annealing algorithm is used to search for the optimum. Finally, an example is discussed in the paper and it can be concluded that the proposed method is effective.

  1. Neonatal Ear Molding: Timing and Technique.

    Science.gov (United States)

    Anstadt, Erin Elizabeth; Johns, Dana Nicole; Kwok, Alvin Chi-Ming; Siddiqi, Faizi; Gociman, Barbu

    2016-03-01

    The incidence of auricular deformities is believed to be ∼11.5 per 10,000 births, excluding children with microtia. Although not life-threatening, auricular deformities can cause undue distress for patients and their families. Although surgical procedures have traditionally been used to reconstruct congenital auricular deformities, ear molding has been gaining acceptance as an efficacious, noninvasive alternative for the treatment of newborns with ear deformations. We present the successful correction of bilateral Stahl's ear deformity in a newborn through a straightforward, nonsurgical method implemented on the first day of life. The aim of this report is to make pediatric practitioners aware of an effective and simple molding technique appropriate for correction of congenital auricular anomalies. In addition, it stresses the importance of very early initiation of ear cartilage molding for achieving the desired outcome.

  2. Ultrasonically-assisted Polymer Molding: An Evaluation

    Science.gov (United States)

    Moles, Matthew; Roy, Anish; Silberschmidt, Vadim

    Energy reduction in extrusion and injection molding processes can be achieved by the introduction of ultrasonic energy. Polymer flow can be enhanced on application of ultrasonic vibration, which can reduce the thermal and pressure input requirements to produce the same molding; higher productivity may also be achieved. In this paper, a design of an ultrasound-assisted injection mold machine is explored. An extrusion-die design was augmented with a commercial 1.5 kW ultrasonic transducer and sonotrode designed to resonate close to 20 kHz with up to 100 μm vibration amplitude. The design was evaluated with modal and thermal analysis using finite-element analysis software. The use of numerical techniques, including computational fluid dynamics, fluid-structure interaction and coupled Lagrangian-Eulerian method, to predict the effect of ultrasound on polymer flow was considered. A sonotrode design utilizing ceramic to enhance thermal isolation was also explored.

  3. De olhos bem abertos: investigando acuidade visual em alunos de uma escola municipal de Vitória

    OpenAIRE

    Mariana Rabello Laignier; Marlúcia de Almeida Castro; Paula dos Santos Cabral de Sá

    2010-01-01

    Esta pesquisa buscou verificar a acuidade visual dos estudantes de uma escola municipal de Vitória Espírito Santo, por meio da aplicação do teste de acuidade visual, baseado na Escala de Snellen; e encaminhar, para exame especializado no ambulatório de oftalmologia do Hospital Universitário Cassiano Antônio Moraes, as crianças que apresentaram déficit visual. Foi um estudo de abordagem quantitativa que discutiu a acuidade visual relacionada ao sexo, idade, série, uso de lentes corretoras e di...

  4. The Elastic Mold Deformation During the Filling and Packing Stage of the Injection Molding Process

    Directory of Open Access Journals (Sweden)

    Stefan Kleindel

    2014-03-01

    Full Text Available The accurate numerical prediction of the mold filling process of long and thin walled parts is dependent on numerous factors. This paper investigates the effect of various influencing variables on the filling pattern by means of simulation and experimental validation. It was found that mold temperature, process settings and venting conditions have little effect on the predicted filling pattern. However, in the actual case study, the filling behavior observed during the experiments was significantly different compared to the numerical prediction. A structural finite element analysis of the moving mold half showed an unacceptable large deformation of the mold plates under injection pressure. A very good correlation between simulation and experiment was attained after improving the stiffness of the mold. Therefore it can be concluded, that the elasticity of the mold may have a significant influence on the filling pattern when long and thin walled products are considered. Furthermore, it was shown, that even an apparently stiff mold can exhibit a distinct deformation during filling and packing stage.

  5. Desempenho econômico e a responsabilidade social corporativa: uma contribuição para a análise da relação destas variáveis no caso das maiores companhias abertas Brasileiras

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Almeida-Santos

    2013-05-01

    Full Text Available Diversas companhias de capital aberto em âmbito mundial têm utilizado práticas de responsabilidade social como uma estratégia para melhorar o retorno de suas ações, isto é, gerar mais ganhos para os seus acionistas. Nesta perspectiva, o propósito deste artigo é testar a teoria que relaciona o desempenho econômico à reputação social corporativa no caso das maiores empresas brasileiras de capital aberto. O desempenho econômico é medido pelo VEA e pelo VMA, ao passo que a reputação corporativa é mensurada dicotomicamente, em que se investigam as 100 maiores empresas de capital aberto por valor de mercado, listadas e não listadas no ISE da BM&Fbovespa. A partir da aplicação da regressão logística, os resultados indicam uma relação positiva e significante entre o desempenho econômico e a reputação social corporativa. Este resultado coaduna com os achados de pesquisas anteriores sobre o assunto. Deste modo, conclui-se que para o caso das 100 maiores empresas brasileiras de capital aberto, é válida a teoria da relação entre o desempenho econômico, a reputação social corporativa e o desempenho econômico. Infere-se que devido algumas das empresas investigadas já estarem no mercado internacional, a reputação social corporativa pode ser uma estratégia utilizada para melhorar o retorno de suas ações e, consequentemente para a expansão dos seus negócios.

  6. Numerical recipes for mold filling simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kothe, D.; Juric, D.; Lam, K.; Lally, B.

    1998-07-01

    Has the ability to simulate the filling of a mold progressed to a point where an appropriate numerical recipe achieves the desired results? If results are defined to be topological robustness, computational efficiency, quantitative accuracy, and predictability, all within a computational domain that faithfully represents complex three-dimensional foundry molds, then the answer unfortunately remains no. Significant interfacial flow algorithm developments have occurred over the last decade, however, that could bring this answer closer to maybe. These developments have been both evolutionary and revolutionary, will continue to transpire for the near future. Might they become useful numerical recipes for mold filling simulations? Quite possibly. Recent progress in algorithms for interface kinematics and dynamics, linear solution methods, computer science issues such as parallelization and object-oriented programming, high resolution Navier-Stokes (NS) solution methods, and unstructured mesh techniques, must all be pursued as possible paths toward higher fidelity mold filling simulations. A detailed exposition of these algorithmic developments is beyond the scope of this paper, hence the authors choose to focus here exclusively on algorithms for interface kinematics. These interface tracking algorithms are designed to model the movement of interfaces relative to a reference frame such as a fixed mesh. Current interface tracking algorithm choices are numerous, so is any one best suited for mold filling simulation? Although a clear winner is not (yet) apparent, pros and cons are given in the following brief, critical review. Highlighted are those outstanding interface tracking algorithm issues the authors feel can hamper the reliable modeling of today`s foundry mold filling processes.

  7. Mold Simulator Study of Heat Transfer Phenomenon During the Initial Solidification in Continuous Casting Mold

    Science.gov (United States)

    Zhang, Haihui; Wang, Wanlin

    2017-01-01

    In this paper, mold simulator trials were firstly carried out to study the phenomena of the initial shell solidification of molten steel and the heat transfer across the initial shell to the infiltrated mold/shell slag film and mold. Second, a one-dimensional inverse heat transfer problem for solidification (1DITPS) was built to determine the temperature distribution and the heat transfer behavior through the solidifying shell from the measured shell thickness. Third, the mold wall temperature field was recovered by a 2DIHCP mathematical model from the measured in-mold wall temperatures. Finally, coupled with the measured slag film thickness and the calculations of 1DITPS and 2DIHCP, the thermal resistance and the thickness of liquid slag film in the vicinity of the meniscus were evaluated. The experiment results show that: the total mold/shell thermal resistance, the mold/slag interfacial thermal resistance, the liquid film thermal resistance, and the solid film thermal resistance is 8.0 to 14.9 × 10-4, 2.7 to 4.8 × 10-4, 1.5 to 4.6 × 10-4, and 3.9 to 6.8 × 10-4 m2 K/W, respectively. The percentage of mold/slag interfacial thermal resistance, liquid film thermal resistance, and solid film thermal resistance over the total mold/shell thermal resistance is 27.5 to 34.4, 17.2 to 34.0, and 38.5 to 48.8 pct, respectively. The ratio of radiation heat flux is around 14.1 to 51.9 pct in the liquid slag film.

  8. Powder injection molding of pure titanium

    Institute of Scientific and Technical Information of China (English)

    GUO Shibo; DUAN Bohua; HE Xinbo; QU Xuanhui

    2009-01-01

    An improved wax-based binder was developed for powder injection molding of pure titanium. A critical powder loading of 69 vol.% and a pseudo-plastic flow behavior were obtained by the feedstock based on the binder. The injection molding, debinding, and sintering process were studied. An ideal control of carbon and oxygen contents was achieved by thermal debinding in vacuum atmosphere (10-3 Pa). The mechanical properties of as-sintered specimens were less than those of titanium made by the conventional press-sintering process. Good shape retention and ±0.04 mm dimension deviation were achieved.

  9. Natural latex (Hevea brasiliensis) mold for neovaginoplasty

    OpenAIRE

    2008-01-01

    OBJETIVO: avaliar a utilização do molde de látex natural (Hevea brasiliensis) como modificação à neovaginoplastia de McIndoe e Bannister em pacientes portadoras da síndrome de Mayer-Rokitansky-Küster-Hauser (MRKH). MÉTODOS: análise retrospectiva de nove pacientes com o diagnóstico de síndrome de MRKH, submetidas à neovaginoplastia pela técnica de McIndoe e Bannister com molde de látex natural. Foram avaliadas epitelização, amplitude e profundidade das neovaginas, ocorrência de coitos bem como...

  10. Proposta de uma estrutura conceitual de modelagem de empresas para implementação do ERP5 baseada na ISO 19440:2007

    OpenAIRE

    Rochetti, Angela Teresa [UNESP

    2009-01-01

    Para o aumento da capacidade gerencial e competitiva das empresas um dos principais recursos é o uso dos sistemas integrados de gestão ou Enterprise Resource Planning (ERP). Os ERPs livres de código aberto têm ganhado uma aceitação cada vez maior, oferecendo vantagens como diminuição dos custos e o acesso ao código. Para usufruir destas vantagens são necessários métodos e ferramentas adequadas para o levantamento do modelo de requisitos de negócios, visando facilitar o desenvolvimento ou impl...

  11. Reduction of Injection Pressure for Thin Walled Molding using the Laser Metal Sintered Mold

    OpenAIRE

    米山, 猛; 内藤, 圭亮; 阿部, 諭; 宮丸, 充

    2010-01-01

    Using milling combined laser metal sintering, porous surface has been fabricated on the thin walled cavity closed by the surrounded thick cavity in the injection mold. Resin flows into the cavity of 2mm thick at first around the thin part and then flows into the thin cavity of 0.2mm thick with 11mm square by packing pressure. The packing pressure for filling the thin part was compared among laser metal sintered mold with or without porous surface, steel mold with or without porous block. The ...

  12. Relationship Between Casting Distortion, Mold Filling, and Interfacial Heat Transfer in Sand Molds

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Parker; K. A. Woodbury; T. S. Piwonka; Y. Owusu

    1999-09-30

    This project sought to determine the relationship between casting dimensions and interfacial heat transfer in aluminum alloy sand castings. The program had four parts; measurement of interfacial heat transfer coefficients in resin bonded and green sand molds, the measurement of gap formation in these molds, the analysis of castings made in varying gatings, orientations and thicknesses, and the measurement of residual stresses in castings in the as-cast and gate removed condition. New values for interfacial heat transfer coefficients were measured, a novel method for gap formation was developed, and the variation of casting dimensions with casting method, gating, and casting orientation in the mold was documented.

  13. Chemotaxis in the Plasmodial Slime Mold, Physarum polycephalum.

    Science.gov (United States)

    Bozzone, Donna M.; Martin, Denise A.

    1998-01-01

    Describes a biology unit designed so that students pose their own questions and perform experiments to answer these questions. Plasmodial slime mold is employed as the focus of the study with background information about the mold provided. (DDR)

  14. EPA Scientists Develop Research Methods for Studying Mold Fact Sheet

    Science.gov (United States)

    In 2002, U.S. Environmental Protection Agency researchers developed a DNA-based Mold Specific Quantitative Polymerase Chain Reaction method (MSQPCR) for identifying and quantifying over 100 common molds and fungi.

  15. Brief Guide to Mold, Moisture, and Your Home

    Science.gov (United States)

    ... plastic or rubber and have removable cartridges that trap most of the mold spores from entering. In ... thank Paul Ellringer, PE, CIH, for providing the photo of Mold growing on the back side of ...

  16. Affordable, Precision Reflector Mold Technology (PDRT08-029) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advances in replication mold technology that reduce material costs, grinding time, and polishing time would enable fabrication of large, precision molds and possibly...

  17. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  18. Exploring the problem of mold growth and the efficacy of various mold inhibitor methods during moisture sorption isotherm measurements.

    Science.gov (United States)

    Yu, X; Martin, S E; Schmidt, S J

    2008-03-01

    Mold growth is a common problem during the equilibration of food materials at high relative humidity values using the standard saturated salt slurry method. Exposing samples to toluene vapor and mixing samples with mold inhibitor chemicals are suggested methods for preventing mold growth while obtaining isotherms. However, no published research was found that examined the effect of mold growth on isotherm performance or the efficacy of various mold inhibitor methods, including their possible effect on the physicochemical properties of food materials. Therefore, the objectives of this study were to (1) explore the effect of mold growth on isotherm performance in a range of food materials, (2) investigate the effectiveness of 4 mold inhibitor methods, irradiation, 2 chemical inhibitors (potassium sorbate and sodium acetate), and toluene vapor, on mold growth on dent corn starch inoculated with A. niger, and (3) examine the effect of mold inhibitor methods on the physicochemical properties of dent corn starch, including isotherm performance, pasting properties, gelatinization temperature, and enthalpy. Mold growth was found to affect starch isotherm performance by contributing to weight changes during sample equilibration. Among the 4 mold inhibitor methods tested, irradiation and toluene vapor were found to be the most effective for inhibiting growth of A. niger on dent cornstarch. However, both methods exhibited a significant impact on the starches' physiochemical properties, suggesting the need to probe the efficacy of other mold inhibitor methods and explore the use of new rapid isotherm instruments, which hamper mold growth by significantly decreasing measurement time.

  19. Dispositivo robótico para guiagem de agulhas flexíveis em procedimentos minimamente invasivos

    OpenAIRE

    Geraldes, André Augusto

    2016-01-01

    Agulhas flexíveis constituem uma nova tecnologia para a realização de procedimentos cirúrgicos minimamente invasivos. Devido a sua capacidade de curvar dentro do corpo do paciente, elas tem potencial de melhorar a performance de diferentes procedimentos cirúrgicos, no entanto o posicionamento preciso deste tipo de agulha ainda é um desafio em aberto na comunidade científica. Neste contexto, este trabalho apresenta o desenvolvimento de um novo dispositivo robótico para guiagem de agulhas flexí...

  20. 240 Mold Sensitization in Chronic Rhinosinusitis Patients

    OpenAIRE

    2012-01-01

    Background It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allergens could be linked to the presence and persistence of asthma, rhinitis and atopic dermatitis. Mold sensitization is a risk factor for development and deterioration of upper airway allergy, especially chronic rhinosinusitis. We addressed the incidence of mold allergy measured as specific IgE to molds and skin prick tests in chronic sinusitis patients. We assessed ...

  1. COMPUTER AIDED THREE DIMENSIONAL DESIGN OF MOLD COMPONENTS

    Directory of Open Access Journals (Sweden)

    Kerim ÇETİNKAYA

    2000-02-01

    Full Text Available Sheet metal molding design with classical methods is formed in very long times calculates and drafts. At the molding design, selection and drafting of most of the components requires very long time because of similar repetative processes. In this study, a molding design program has been developed by using AutoLISP which has been adapted AutoCAD packet program. With this study, design of sheet metal molding, dimensioning, assemly drafting has been realized.

  2. Inovação aberta na gestão pública: análise do plano de ação brasileiro para a Open Government Partnership

    Directory of Open Access Journals (Sweden)

    Rony Klay Viana de Freitas

    2014-08-01

    Full Text Available Este estudo objetivou analisar o Plano de Ação brasileiro para o Governo Aberto, baseado na teoria da inovação aberta na gestão pública. Utilizou-se de uma pesquisa documental, com vistas a aprofundar o conhecimento do fenômeno em questão. O documento foi escolhido intencionalmente, por ser exemplo basilar das políticas públicas relacionadas à inovação aberta brasileira. Os resultados mostram que os compromissos firmados pelo governo brasileiro estão consoantes com o processo de inovação aberta pública. As ações previstas no Plano estão especificamente relacionadas a transparência, abertura de dados e preparação do corpo estatal para o processo aberto de inovação.

  3. 21 CFR 874.3430 - Middle ear mold.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Middle ear mold. 874.3430 Section 874.3430 Food... DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3430 Middle ear mold. (a) Identification. A middle ear mold is a preformed device that is intended to be implanted to reconstruct the middle...

  4. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...

  5. Comparison of two setups for induction heating in injection molding

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2015-01-01

    To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness, ...

  6. Reducción del Tiempo de Ciclo de Inyección de Termoplásticos con el uso de Moldes con Tratamiento Superficial por Nitruración Cycle Time Reduction of Thermoplastic Injection using Nitriding Treatment Surface Molds

    Directory of Open Access Journals (Sweden)

    Emerson J Corazza

    2012-01-01

    Full Text Available Se presenta un estudio sobre la transferencia de calor en un molde, comparando los ensayos de inyección utilizando moldes con y sin tratamiento superficial de nitruración. Simulaciones del proceso se realizaron con el uso de Asistencia Computacional a Ingeniería (CAE para determinar los parámetros iniciales que se aplicaron en los ensayos reales en moldes instrumentados de acero P20 (con y sin tratamientos, inyectados con el polímero poliestireno cristal. Los resultados indicaron una reducción del tiempo de enfriamiento y del tiempo de proceso en el molde con el tratamiento, debido a una mejora en la conductividad térmica.A study on the heat transfer in a mold, comparing experimental injection tests using a mold with and without surface treatment (nitriding is presented. Process simulations were carried out using Computer Aided Engineering tools (CAE for the estimation of the initial parameters to be applied in the tests in instrumented P20 steel injection molds with the polymer crystal polystyrene. Results indicated a reduction of cooling time and of the time of the process in the mold with treatment, due to an increase of the thermal conductivity.

  7. Fabrication of silicon molds for polymer optics

    DEFF Research Database (Denmark)

    Nilsson, Daniel; Jensen, Søren; Menon, Aric Kumaran

    2003-01-01

    A silicon mold used for structuring polymer microcavities for optical applications is fabricated, using a combination of DRIE (deep reactive ion etching) and anisotropic chemical wet etching with KOH + IPA. For polymer optical microcavities, low surface roughness and vertical sidewalls are often...

  8. Onychomycosis by molds. Report of 78 cases.

    Science.gov (United States)

    Bonifaz, Alexandro; Cruz-Aguilar, Pamela; Ponce, Rosa María

    2007-01-01

    A retrospective study of onychomycohosis by molds was carried out during a 14-year period (1992-2005). All cases were clinically and mycologically proven (repetitive KOH and culture) and then each of the molds was identified. A total of 5,221 cases of onychomycosis were evaluated, 78 of which were molds (1.49%). Mean patient age was 44.1 years. 75/78 cases occurred in toenails. Associated factors were detected in 39/78 (50.0%) cases, with the major ones being: peripheral vascular disease, contact with soil, and trauma. The most frequent clinical presentation was distal and lateral subungual onychomycosis (DLSO), in 54/78 cases (69%). The most frequent causative agents were: Scopulariopsis brevicaulis in 34/78 cases and Aspergillus niger in 13/78 cases. Onychomycoses by molds are infrequent; in this study they accounted for 1.49% of cases. The clinical features are virtually similar to those caused by dermatophytes, which makes the clinicomycological tests necessary.

  9. Flexible Interior-Impression-Molding Tray

    Science.gov (United States)

    Anders, Jeffrey E.

    1991-01-01

    Device used inside combustion chamber of complicated shape for nondestructive evaluation of qualities of welds, including such features as offset, warping, misalignment of parts, and dropthrough. Includes flexible polypropylene tray trimmed to fit desired interior surface contour. Two neodymium boron magnets and inflatable bladder attached to tray. Tray and putty inserted in cavity to make mold of interior surface.

  10. Molding cork sheets to complex shapes

    Science.gov (United States)

    Sharpe, M. H.; Simpson, W. G.; Walker, H. M.

    1977-01-01

    Partially cured cork sheet is easily formed to complex shapes and then final-cured. Temperature and pressure levels required for process depend upon resin system used and final density and strength desired. Sheet can be bonded to surface during final cure, or can be first-formed in mold and bonded to surface in separate step.

  11. Epidemics of mold poisoning past and present.

    Science.gov (United States)

    Meggs, William J

    2009-01-01

    Molds are ubiquitous throughout the biosphere of planet earth and cause infectious, allergic, and toxic diseases. Toxic diseases arise from exposure to mycotoxins produced by molds. Throughout history, there have been a number of toxic epidemics associated with exposure to mycotoxins. Acute epidemics of ergotism are caused by consumption of grain infested by fungi of the genus Claviceps, which produce the bioactive amine ergotamine that mimics the neurotransmitters norepinephrine, serotonin, and dopamine. Acute aflatoxin outbreaks have occurred from ingestion of corn stored in damp conditions that potentiate growth of the molds of the species Aspergillus. Contemporary construction methods that use cellulose substrates such as fiber board and indoor moisture have caused an outbreak of contaminated buildings with Stachybotrys chartarum, with the extent of health effects still a subject of debate and ongoing research. This article reviews several of the more prominent epidemics and discusses the nature of the toxins. Two diseases that were leading causes of childhood mortality in England in the 1970s and vanished with changing dietary habits, putrid malignant fever, and slow nervous fever were most likely toxic mold epidemics.

  12. Introducing the slime mold graph repository

    Science.gov (United States)

    Dirnberger, M.; Mehlhorn, K.; Mehlhorn, T.

    2017-07-01

    We introduce the slime mold graph repository or SMGR, a novel data collection promoting the visibility, accessibility and reuse of experimental data revolving around network-forming slime molds. By making data readily available to researchers across multiple disciplines, the SMGR promotes novel research as well as the reproduction of original results. While SMGR data may take various forms, we stress the importance of graph representations of slime mold networks due to their ease of handling and their large potential for reuse. Data added to the SMGR stands to gain impact beyond initial publications or even beyond its domain of origin. We initiate the SMGR with the comprehensive Kist Europe data set focusing on the slime mold Physarum polycephalum, which we obtained in the course of our original research. It contains sequences of images documenting growth and network formation of the organism under constant conditions. Suitable image sequences depicting the typical P. polycephalum network structures are used to compute sequences of graphs faithfully capturing them. Given such sequences, node identities are computed, tracking the development of nodes over time. Based on this information we demonstrate two out of many possible ways to begin exploring the data. The entire data set is well-documented, self-contained and ready for inspection at http://smgr.mpi-inf.mpg.de.

  13. Residual thermal stresses in injection molded products

    NARCIS (Netherlands)

    Zoetelief, W.F.; Douven, L.F.A.; Ingen Housz, A.J.

    1996-01-01

    Nonisothermal flow of a polymer melt in a cold mold cavity introduces stresses that are partly frozen-in during solidification. Flow-induced stresses cause anisotropy of mechanical, thermal, and optical properties, while the residual thermal stresses induce warpage and stress-cracking. In this study

  14. Injection molding of micro patterned PMMA plate

    Institute of Scientific and Technical Information of China (English)

    Yeong-Eun YOO; Tae-Hoon KIM; Tae-Jin JE; Doo-Sun CHOI; Chang-Wan KIM; Sun-Kyung KIM

    2011-01-01

    A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 mm×213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 mm. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate (PMMA) was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

  15. Mold Die Making. 439-322/324.

    Science.gov (United States)

    Yunke, P.; And Others

    Each unit in this curriculum guide on mold die making contains an introduction, objectives, materials required, lessons, space for notes, figures, and diagrams. There are 10 units in this guide: (1) introduction to Electrical Discharge Machining (EDM); (2) EDM principles; (3) the single pulse; (4) EDM safety; (5) electrode material; (6) electrode…

  16. A REVOLUTION IN MOLD IDENTIFICATION AND ENUMERATION

    Science.gov (United States)

    More than 100 assay were developed to identify and quantify indoor molds using quantitiative PCR (QPCR) assays. This technology incorporates fluorigenic 5' nuclease (TaqMan�) chemistry directed at the nuclear ribosomal RNA operon internal transcribed spacer regions (ITS1 or ITS2...

  17. Progress in Titanium Metal Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Randall M. German

    2013-08-01

    Full Text Available Metal powder injection molding is a shaping technology that has achieved solid scientific underpinnings. It is from this science base that recent progress has occurred in titanium powder injection molding. Much of the progress awaited development of the required particles with specific characteristics of particle size, particle shape, and purity. The production of titanium components by injection molding is stabilized by a good understanding of how each process variable impacts density and impurity level. As summarized here, recent research has isolated the four critical success factors in titanium metal powder injection molding (Ti-MIM that must be simultaneously satisfied—density, purity, alloying, and microstructure. The critical role of density and impurities, and the inability to remove impurities with sintering, compels attention to starting Ti-MIM with high quality alloy powders. This article addresses the four critical success factors to rationalize Ti-MIM processing conditions to the requirements for demanding applications in aerospace and medical fields. Based on extensive research, a baseline process is identified and reported here with attention to linking mechanical properties to the four critical success factors.

  18. Residual stresses in injection molded products

    NARCIS (Netherlands)

    Jansen, K.M.B.

    2015-01-01

    During the molding process residual stresses are formed due to thermal contraction during cooling as well as the local pressure history during solidification. In this paper a simple analytical model is reviewed which relates residual stresses, product shrinkage as well as warpage to the temperature

  19. Cultural Molding: A Modular Approach. Cultural Anthropology.

    Science.gov (United States)

    Kassebaum, Peter

    Designed for use as supplementary instructional material in a cultural anthropology course, this learning module introduces the student to cultural molding, the idea that most human behavior can be traced to enculturation and exposure rather than to a socio-biological explanation of human behavior. Following a brief description of socialization,…

  20. A REVOLUTION IN MOLD IDENTIFICATION AND ENUMERATION

    Science.gov (United States)

    More than 100 assay were developed to identify and quantify indoor molds using quantitiative PCR (QPCR) assays. This technology incorporates fluorigenic 5' nuclease (TaqMan�) chemistry directed at the nuclear ribosomal RNA operon internal transcribed spacer regions (ITS1 or ITS2...

  1. Design of Revolute Joints for In-Mold Assembly Using Insert Molding.

    Science.gov (United States)

    Ananthanarayanan, Arvind; Ehrlich, Leicester; Desai, Jaydev P; Gupta, Satyandra K

    2011-12-01

    Creating highly articulated miniature structures requires assembling a large number of small parts. This is a very challenging task and increases cost of mechanical assemblies. Insert molding presents the possibility of creating a highly articulated structure in a single molding step. This can be accomplished by placing multiple metallic bearings in the mold and injecting plastic on top of them. In theory, this idea can generate a multi degree of freedom structures in just one processing step without requiring any post molding assembly operations. However, the polymer material has a tendency to shrink on top of the metal bearings and hence jam the joints. Hence, until now insert molding has not been used to create articulated structures. This paper presents a theoretical model for estimating the extent of joint jamming that occurs due to the shrinkage of the polymer on top of the metal bearings. The level of joint jamming is seen as the effective torque needed to overcome the friction in the revolute joints formed by insert molding. We then use this model to select the optimum design parameters which can be used to fabricate functional, highly articulating assemblies while meeting manufacturing constraints. Our analysis shows that the strength of weld-lines formed during the in-mold assembly process play a significant role in determining the minimum joint dimensions necessary for fabricating functional revolute joints. We have used the models and methods described in this paper to successfully fabricate the structure for a minimally invasive medical robot prototype with potential applications in neurosurgery. To the best of our knowledge, this is the first demonstration of building an articulated structure with multiple degrees of freedom using insert molding.

  2. Characteristics and influence factors of mold filling process in permanent mold with a slot gating system

    Institute of Scientific and Technical Information of China (English)

    Chang Qingming; Chen Xia; Chen Changjun; Bao Siqian; David Schwam

    2009-01-01

    The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. In this study, the slot gating system is employed to improve mold filling behavior and therefore, to improve the quality of aluminum castings produced in permanent molds. An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum flowing into permanent molds have been developed. Graphite molds transparent to X-rays are utilized which make it possible to observe the flow pattern through a number of vertically oriented gating systems. The investigation discovers that there are many influencing factors on the mold filling process. This paper focuses its research on some of the factors, such as the dimensions of the vertical riser and slot thickness, as well as roughness of the coating layer. The results indicate that molten metal can smoothly fill into casting cavity with a proper slot gating system. A bigger vertical riser, proper slot thickness and rougher coating can provide not only a better mold filling pattern, but also hot melt into the top of the cavity. A proper temperature gradient is obtainable, higher at the bottom and lower at the top of the casting cavity, which is in favor of feeding during casting solidification.

  3. A clínica psicanalítica nos espaços abertos do CAPS

    Directory of Open Access Journals (Sweden)

    Junia de Vilhena

    2011-01-01

    Full Text Available Este texto realiza una reflexión sobre los obstáculos que presenta el psicoanálisis clínico dentro de la institución pública al formarse a partir de la Reforma Psiquiátrica, cuestionando la relación entre el psicoanálisis y otros conocimientos y prácticas que coexisten dentro de un Centro de Atención Psicosocial (CAPS. Retoma, históricamente, el papel del diagnóstico psiquiátrico en la salud mental, su separación del campo de la filosofía y la psicopatología, y las posibilidades actuales que poseen estas clínicas emblemáticas para expresar el sufrimiento y peculiaridad de los pacientes. También cuestiona la forma como el psicoanálisis y los psicoanalistas conciben la inclusión de esta práctica en el contexto de las instituciones, considerando las diferencias de contexto y la diversidad de actores que participan en el proceso analítico. Propone un paralelismo entre las prácticas dirigidas a la recuperación de la ciudadanía de la "locura" y el ideal buscado por la clínica de la subjetividad.

  4. Práticas de responsabilidade socioambiental nas empresas de capital aberto de Santa Catarina listadas na BM&FBOVESPA = Social responsibility practices in open capital companies from Santa Catarina listed on BM&FBOVESPA

    Directory of Open Access Journals (Sweden)

    Daniela Di Domenico

    2015-08-01

    Full Text Available Este artigo tem como objetivo identificar as práticas de ações de responsabilidade social corporativa das sociedades anônimas de capital aberto de Santa Catarina listadas na BM&FBovespa. A justificativa da pesquisa está atrelada à influência da evidenciação dessas informações para os investidores, pesquisadores e usuários das informações ambientais. Quanto aos procedimentos metodológicos o estudo caracteriza-se como exploratório quanto aos objetivos, documental em relação aos procedimentos e a abordagem do problema é predominantemente qualitativa. As empresas que fazem parte da amostra são: BRF S.A., BUETTNER S.A., CASAN, KARSTEN S.A e WEG S.A. Foram várias as práticas de responsabilidade social e ambiental evidenciadas, mas se pode identificar que todas têm como objetivo divulgar a empresa, além do objetivo principal da ação realizada. É possível destacar as principais práticas como sendo as ações e cuidados para o consumo consciente da água e energia, usando fontes que não sejam prejudiciais ao meio ambiente. Outra ação em destaque é o cuidado com a destinação dos resíduos sólidos e líquidos, gerados nos processos operacionais das empresas. A preocupação com a poluição da atmosfera também é evidente, por ser um dos principais problemas ambientais na atualidade.This article aims at identifying the practices of corporate social responsibility of corporations with open capital of Santa Catarina listed BM&FBovespa. The justification of this research is related to the influence of the disclosure of information for the investors, researchers and users of environmental information. In the methodological procedures, the study is characterized as exploratory as its goals, documental regarding the procedures and its approach to the problem is predominantly qualitative. The companies included in the sample are: BRF SA, BUETTNER SA, CASAN, KARSTEN SA and WEG SA. There were several social and environmental

  5. Gestão ambiental nas empresas de capital aberto do segmento ‘Novo Mercado’: discutindo a homogeneidade e heterogeneidade de práticas à luz da teoria institucional [doi: 10.5329/RECADM.20121102003

    Directory of Open Access Journals (Sweden)

    Vivianne Pereira Salas Roldan

    2012-11-01

    Full Text Available O objetivo geral deste estudo foi analisar o comportamento das empresas de capital aberto, do segmento ‘Novo Mercado’ da BM&FBovespa, quanto à adoção de práticas de gestão ambiental, à luz da teoria institucional. Em síntese, os objetivos específicos da pesquisa analisam a tendência para a homogeneidade e heterogeneidade de práticas ambientais das empresas, sua relação com a abordagem de gestão ambiental e com as pressões ambientais evidenciadas, dando destaque especial para o setor de Construção. É uma pesquisa descritiva, bibliográfica e documental, de abordagem quantitativa. Os dados foram obtidos a partir dos websites e relatórios anuais das empresas, de 2009 e 2010. Constatou-se que 66,7% das 123 empresas do Novo Mercado adotam práticas ambientais. Quanto à abordagem de gestão ambiental, 58,5% dessas empresas são proativas, 28% reativas, e 13,4% preventivas. Verificou-se que quanto mais proativa a abordagem de gestão ambiental, mais diversificadas são as pressões ambientais, e maior é a possibilidade de existir isomorfismo entre as empresas quanto à adoção de práticas sustentáveis, assim como heterogeneidade. Na análise do setor de construção, constatou-se essas possibilidades destacadas, sendo as práticas homogêneas e heterogêneas desse campo detalhadas e discutidas no estudo.   Palavras-chave Teoria institucional, Pressões ambientais, Gestão Ambiental.     ENVIRONMENTAL MANAGEMENT OF COMPANIES OF THE SEGMENT 'NEW MARKET': DISCUSSING THE HOMOGENEITY AND HETEROGENEITY OF PRACTICES IN LIGHT OF INSTITUTIONAL THEORY   ABSTRACT The aim of this study was to analyze the behavior of companies of the segment 'New Market' BM&FBovespa, on the adoption of environmental management practices in light of institutional theory. In summary, the specific objectives of the research analyzing the trend toward homogeneity and heterogeneity of environmental practices of firms, their relationship with the approach

  6. Computer simulation for centrifugal mold filling of precision titanium castings

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Computer simulation codes were developed based on a proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings (CASM-3D for Windows). Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings under a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section precision castings.

  7. Testing single point incremental forming molds for thermoforming operations

    Science.gov (United States)

    Afonso, Daniel; de Sousa, Ricardo Alves; Torcato, Ricardo

    2016-10-01

    Low pressure polymer processing processes as thermoforming or rotational molding use much simpler molds then high pressure processes like injection. However, despite the low forces involved with the process, molds manufacturing for this operations is still a very material, energy and time consuming operation. The goal of the research is to develop and validate a method for manufacturing plastically formed sheets metal molds by single point incremental forming (SPIF) operation for thermoforming operation. Stewart platform based SPIF machines allow the forming of thick metal sheets, granting the required structural stiffness for the mold surface, and keeping the short lead time manufacture and low thermal inertia.

  8. The Facility and Process Technics of Polyethylene Rotational Molding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ 1. Introduction Rotational molding is the process by which hollow plastic parts are formed. It mainly processes the product which Injection molding and Blow molding can not process medium-sized, large-sized and super large-sized plastic parts. The technics may turn out a tub, dustbin, stock tank, sailboat. The research institute of Lanzhou introduces a suit of RS-16 Rotational Molding Machine from Germany Reinhadt Co. on 1990. It mainly put up experiment and smallscale production. RS-16 rotational molding machine is a single arm and di-axial equipment. It is consisting of a gas heated sintering oven, cooling chamber, mouldcarrying carriage and a controlling unit.

  9. Mold infestation of wet spray-applied cellulose insulation.

    Science.gov (United States)

    Godish, Thad J; Godish, Diana R

    2006-01-01

    Mold investigations were conducted in four buildings that had been insulated with wet spray-applied cellulose insulation (WSACI). Bulk WSACI samples were collected and analyzed by quantitative polymerase chain reaction (QPCR) methods. Airborne mold was evaluated using both Burkard total mold spore and Andersen culturable/viable sampling methods. Although reportedly treated with biocidal borates, QPCR analyses indicated that elevated concentrations of mold cells (reported as spore equivalents per gram) may be present in WSACI. QPCR analyses showed the following: (1) very high concentrations of Penicillium chrysogenum in samples from two of four buildings; (2) very high concentrations of Stachybotrys chartarum in samples from one building and a more moderate presence in a second; (3) moderately high concentrations of Aspergillus versicolor in samples from one building and more moderate concentrations in a second; (4) the presence of the opportunistic pathogen, Aspergillus fumigatus, in samples from three of the four buildings, and (5) the presence of 22 of 23 target mold species. Elevated airborne total mold spore concentrations were observed in all four of the buildings investigated. Culturable/viable airborne mold concentrations were moderately elevated in three of the four buildings. Mold genera/types present were relatively consistent among airborne mold samples collected by both methods and bulk sample analyses. Results of this study suggest that WSACI has the potential to cause elevated airborne mold levels in buildings where it has been applied and pose significant mold exposure and public health risks.

  10. Wavelet Packet Decomposition to Characterize Injection Molding Tool Damage

    Directory of Open Access Journals (Sweden)

    Tomaž Kek

    2016-02-01

    Full Text Available This paper presents measurements of acoustic emission (AE signals during the injection molding of polypropylene with new and damaged mold. The damaged injection mold has cracks induced by laser surface heat treatment. Standard test specimens were injection molded, commonly used for examining the shrinkage behavior of various thermoplastic materials. The measured AE burst signals during injection molding cycle are presented. For injection molding tool integrity prediction, different AE burst signals’ descriptors are defined. To lower computational complexity and increase performance, the feature selection method was implemented to define a feature subset in an appropriate multidimensional space to characterize the integrity of the injection molding tool and the injection molding process steps. The feature subset was used for neural network pattern recognition of AE signals during the full time of the injection molding cycle. The results confirm that acoustic emission measurement during injection molding of polymer materials is a promising technique for characterizing the integrity of molds with respect to damage, even with resonant sensors.

  11. O poema como um diagrama aberto: a poesia gráfico-digital de André Vallias

    Directory of Open Access Journals (Sweden)

    Maíra Borges Wiese

    2013-07-01

    Full Text Available http://dx.doi.org/10.5007/1807-9288.2013v9n1p150   O poeta André Vallias configura-se como um dos nomes pioneiros da poesia digital. Em 1991, foi curador, juntamente com Friedrich Block, da “Primeira Mostra Internacional de Poesia Digital”, a P0es1s, e publicou poemas multimídias e hipermídias em sites e antologias nacionais e internacionais. Em um artigo intitulado “Nous n’avons pas compris Descartes”, Vallias define uma concepção de poema que guiará a sua primeira série de poemas digitais – poemas gráficos, poemas-diagramas –, e retomada nas suas produções multimídia e hipermídia subsequentes. Trata-se da visão do poema como um “diagrama aberto”, um poema que se constrói a partir de uma interrelação de códigos, liberto da predominância do signo verbal, dotados de intermidialidade. Este artigo propõe uma interpretação de três poemas desta primeira série, desenvolvidos através do software de desenho AutoCAD e posteriormente remediados para a interface da Web. As interpretações visam, em primeiro lugar, iluminar alguns dos possíveis sentidos desenvolvidos pelos poemas; e, em segundo, apontar a relação que os poemas estabelecem, por suas características, com aspectos da poética digital como um todo.

  12. Estudo terapêutico aberto com sulfato de aminosidine na leishmaniose mucosa causada for Leishmania (viannia braziliensis

    Directory of Open Access Journals (Sweden)

    Gustavo A.S. Romero

    1996-12-01

    Full Text Available No período de setembro a novembro de 1994 foram tratados 21 pacientes com leishmaniose mucosa ativa, predominantemente adultos lavradores do sexo masculino, com sulfato de aminosidine intramuscular, I6mg/kg/dia por 20 dias. Treze pacientes eram virgens de tratamento e 8 haviam sido tratados sem sucesso com Glucantime®". O diagnóstico baseou-se inicialmente em crítêrios epidemiolôgicos, clínicos e nos resultados da intrademoireação de Montenegro e a imunofluorescência indireta para anticoipos séricos antileishmânia e durante o acompanhamento nos resultados dos estudos parasitológicos. Sessenta e sete por cento dos pacientes tiveram diagnóstico parasitológico confirmado sendo a inoculação do material de biópsia das lesões em hamsters o método mais sensível. O tempo médio de acompanhamento foi de 12,6 meses. A adesão ao tratamento foi de 100%. Os efeitos colaterais foram dor no local da injeção (86%, proteinúria leve (24%, elevação do nível sérico de creatinina (5% e perda auditiva subclínica em um dos dois pacientes que realizaram audiometria. Obsevou-se cura clínica em 48% dos pacientes e a percentagem acumulada de recidiva foi de 29% (4/14pacientes durante o acompanhamento.

  13. Direct molding of pavement tiles made of ground tire rubber

    Science.gov (United States)

    Quadrini, Fabrizio; Gagliardi, Donatella; Tedde, Giovanni Matteo; Santo, Loredana; Musacchi, Ettore

    2016-10-01

    Large rubber products can be molded by using only ground tire rubber (GTR) without any additive or binder due to a new technology called "direct molding". Rubber granules and powders from tire recycling are compression molded at elevated temperatures and pressures. The feasibility of this process was clearly shown in laboratory but the step to the industrial scale was missing. Thanks to an European Project (SMART "Sustainable Molding of Articles from Recycled Tires") this step has been made and some results are reported in this study. The press used for compression molding is described. Some tests were made to measure the energy consumption so as to evaluate costs for production in comparison with conventional technologies for GTR molding (by using binders). Results show that 1 m2 tiles can be easily molded with several thicknesses in a reasonable low time. Energy consumption is higher than conventional technologies but it is lower than the cost for binders.

  14. Stability of FDTS monolayer coating on aluminum injection molding tools

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.

    2012-01-01

    The injection molding industry often employs prototype molds and mold inserts from melt spun (rapid solidification processing [1,2]) aluminum, especially for applications in optics [3,4], photonics [5] and microfludics. Prototypes are also used for verification of mold filling. The use of aluminum...... tools has reduced lead time (days instead of weeks) and manufacturing cost (30% of conventional mold). Moreover, for aluminum, a surface roughness (RMS) below 5 nm can be obtained with diamond machining [3,4,6]. Conventional mold coatings add cost and complexity, and coatings with thicknesses of a few...... trichloro-silane based coating deposited on aluminum or its alloys by molecular vapor deposition. We have tested the stability of this coating in challenging conditions of injection molding, an environment with high shear stress from the molten polymer, pressures up to 200 MPa, temperatures up to 250 ◦C...

  15. Mold exposure and health effects following hurricanes Katrina and Rita.

    Science.gov (United States)

    Barbeau, Deborah N; Grimsley, L Faye; White, LuAnn E; El-Dahr, Jane M; Lichtveld, Maureen

    2010-01-01

    The extensive flooding in the aftermath of Hurricanes Katrina and Rita created conditions ideal for indoor mold growth, raising concerns about the possible adverse health effects associated with indoor mold exposure. Studies evaluating the levels of indoor and outdoor molds in the months following the hurricanes found high levels of mold growth. Homes with greater flood damage, especially those with >3 feet of indoor flooding, demonstrated higher levels of mold growth compared with homes with little or no flooding. Water intrusion due to roof damage was also associated with mold growth. However, no increase in the occurrence of adverse health outcomes has been observed in published reports to date. This article considers reasons why studies of mold exposure after the hurricane do not show a greater health impact.

  16. Ultra-precision molding of chalcogenide glass aspherical lens

    Science.gov (United States)

    Zhang, Feng; Wang, Zhibin; Zhang, Yunlong; Su, Ying; Guo, Rui; Xu, Zengqi; Liu, Xuanmin

    2016-10-01

    With the development of infrared optical systems in military and civil areas, chalcogenide glass aspherical lens possess some advantages, such as large infrared transmission, good thermal stability performance and image quality. Aspherical lens using chalcogenide glass can satisfy the requirements of modern infrared optical systems. Therefore, precision manufacturing of chalcogenide glass aspheric has received more and more attention. The molding technology of chalcogenide glass aspheric has become a research hotspot, because it can achieve mass and low cost manufacturing. The article of molding technology is focusing on a kind of chalcogenide glass aspherical lens. We report on design and fabrication of the mold that through simulation analysis of molding. Finally, through molding test, the fabrication of mold's surface and parameters of molding has been optimized, ensuring the indicators of chalcogenide glass aspherical lens meet the requirements.

  17. JUSTIFICATION OF RATIONAL KINEMATIC CHARACTERISTICS OF MOLDING VIBRATING TABLE

    Directory of Open Access Journals (Sweden)

    P. G. Anofriev

    2016-12-01

    Full Text Available Purpose. One of the efficient ways to obtain castings of complex shape is lost foam casting (LFC in the evacuated molds (containers. Upgrading the quality of this casting method requires improvement of molding techniques. The molding process involves layer-by-layer vibratory compaction of sand in the containers. Most of the lines of LFC sections are equipped with vibrating tables with inertia oscillators driven by induction motors, operating at nominal speed. A promising way of improving the molding technique is the rational setting of the following parameters of vibrating table: vibration displacement, velocity and acceleration. These parameters are determined by the elastic-mass characteristics of the system «vibrating table – mold» and perturbing forces created by inertia oscillators. The aim of the study is to determine the rational range of setting the parameters of oscillators at which the qualitative layer-by-layer compaction of the molding sand in the mold takes place. Methodology. The efficiency criterion for setting characteristics of the vibrating table there were taken the values of averaged accelerations of 6.5 – 7.5 m/s2 corresponding to maximum compaction degree of dry molding sand and the range of acceleration values 9 – 9.5 m/s2 for giving the sand «pseudo-yielding». For the study it was developed a mathematical model of oscillations of the movable part of vibrating table with two types of casting containers for steady and transient operation modes. Findings. In the process of research of the mold oscillations it was calculated the natural frequencies of oscillations at different elastic-mass characteristics of the system using a mathematical model. It was constructed the frequency response of displacements and accelerations of the moving part of the table with container filled with molding sand layer-by-layer. Originality. The author proposes a method of determining the range of frequency setting of inertial

  18. Cranioplastia primária nos afundamentos do crânio com ferimento aberto do couro cabeludo Primary cranioplasty in open depressed fractures of the skull

    Directory of Open Access Journals (Sweden)

    Darcy de Freitas Vellutini

    1972-06-01

    Full Text Available Os autores referem 13 casos de afundamentos crânio-encefálicos pós-traumáticos com ferimento aberto do couro cabeludo nos quais foi usado o metilmetacrilato em uma única intervenção cirúrgica. A sede do afundamento era frontal em 9 casos, parietal em dois, parieto-temporal em um e parieto-occipital em um. Os afundamentos interessavam apenas a tábua óssea em 5 casos, estavam associados a lesão de dura-mater em três e também do tecido cerebral em 5. Foi realizada cranioplastia simples em 5 casos e, em 8, ela foi precedida de plástica de dura-mater. O seguimento pós-operatório variou de dois meses a dois anos; até o momento não foi assinalada ocorrência de infecção ou de fenômeno de rejeição da prótese que obrigasse a sua retirada.Thirteen cases of open depressed fractures of the skull in which methyl-methacrylate was primarily used are reported. The site of the depressed fractures was frontal in 9 cases, parietal in two, parieto-temporal in one and parieto-occipital in one. In 5 cases, only the bone was injured; in three cases dura mater was damaged; in 5 cases brain and dura mater were damaged. In 5 cases, only a cranioplasty was performed and in 8 cases a dura mater graft was associated. The follow-up was from two months to two years without any complication as infection or rejection of the methylmethacrylate.

  19. Profilaxia da migrânea: estudo aberto com a venlafaxina em 42 pacientes Prophylaxis of migraine: open study with venlafaxine in 42 patients

    Directory of Open Access Journals (Sweden)

    ESTÊVÃO DEMÉTRIO NASCIMENTO

    1998-12-01

    Full Text Available O presente estudo aberto teve por objetivo avaliar a eficácia da venlafaxina (inibidor da recaptação da serotonina e da noradrenalina na prevenção das crises de migrânea com ou sem aura em 42 pacientes com idade média de 32,5 anos e variação de 13 a 48 anos. O sexo feminino predominou sobre o masculino. A avaliação ocorreu de maio a setembro de 1997. O tempo de avaliação foi de 4 meses. A média de crises por mês era 3,8. Os efeitos colaterais mais consistentes foram a perda de peso, náuseas e vômitos. A venlafaxina mostrou-se eficaz em 37 dos 42 pacientes selecionados (88,07 % com doses variando de 18,75 - 37,5 mg/dia.The present open study intended to show the prophylactic value of venlafaxine (serotonin and noradrenalin reuptake inhibitor in 42 patients with migraine with or without aura during four months, from May to September 1997. The average age was 32.5 years and average crisis was 3.8 per month. Consistent side-effects included loss of weight, nausea and vomit. The efficacy of drug occurred in 37 patients (88.07% with dosis of 18.75 to 37.5 mg/day. We conclude that venlafaxine is an effective drug in prophylaxis of migraine patients.

  20. La fabricación de lucernas en Tritium Magallum: un molde inédito de M. Oppi Zosi

    Directory of Open Access Journals (Sweden)

    Sáenz Preciado, J. Carlos

    2015-12-01

    Full Text Available This article proposes a research, centered on the lower part of a lamp over-mold, discovered during the excavations of El Quemao (Tricio. The mold was obtained from an original lamp of the Italic potter M. OPPI ZOSI, well distributed in North Africa in the Antonine period. Probably, the original lamp used for the elaboration of the mold was brought, rightly from Africa, by a legionary or a veteran of the legio VII, who was then settled at Tritium.Este artículo presenta una investigación centrada en la parte inferior de un sobremolde de lucerna, descubierto durante las excavaciones de El Quemao (Tricio. El molde fue obtenido de una lucerna original del alfarero itálico OPPI ZOSI, comercializado en África del Norte en época antonina. Probablemente, la lámpara original usada para la elaboración del molde fue traída desde África por un legionario o un veterano del Legio VII, asentada en Tritium.

  1. An education belief worth reflection: Molding intellectuals

    Institute of Scientific and Technical Information of China (English)

    Lu Jie

    2006-01-01

    Molding intellectuals is one of the expectations people have,which comes from a deep-rooted belief in education.The humanity hypothesis of this belief is to take knowledge and the pursuit of knowledge as the only prescription for human beings.This hypothesis overturns the relation of knowledge and life.Intellectuals make scientific paradigm as the limit of knowledge.Experience and consciousness outside the paradigm are ejected from the scope of knowledge.Accordingly,knowledge of intellectuals is broken away from a human being's life.Under the domination of this conception of knowledge,the world of intellectuals has become a world deficient of meaning.The belief that education molds intellectuals should be deconstructed gradually,with criticism in both practice and theory.

  2. Diagnosis parameters of mold filling pattern for optimization of a casting system

    OpenAIRE

    2012-01-01

    For optimal design of a gating system, the setting of diagnosis parameters is very important. In this study, the permanent mold casting process was selected because most of the other casting processes have more complicated factors that influence the mold filling pattern compared to the permanent mold casting process, such as the surface roughness of mold, gas generation from the mold wash and binder of sand mold, and the gas permeability through a sand mold, etc. Two diagnosis parameters (fl...

  3. Manufacturing Science of Improved Molded Optics

    Science.gov (United States)

    2013-12-05

    a physical point shear thinning is an unlikely explanation. In a study of friction mechanisms in polymer extrusion , Joshi et al.27 present a...41 Appendix C2 – glass extrusion paper draft 61 Appendix C3 - ring compression test paper draft (Navier law) 97 D. Protective coatings...complex thermo-mechanical behavior of an optical glass during simulation of the lens molding, extrusion and other glass forming processes. This

  4. Fractal phenomena in powder injection molding process

    Institute of Scientific and Technical Information of China (English)

    郑洲顺; 曲选辉; 李云平; 雷长明; 段柏华

    2003-01-01

    The complicated characteristics of the powder were studied by fractal theory. It is illustrated that powder shape, binder structure, feedstock and mold-filling flow in powder injection molding process possess obvious fractal characteristics. Based on the result of SEM, the fractal dimensions of the projected boundary of carbonylic iron and carbonylic nickel particles were determined to be 1.074±0.006 and 1.230±0.005 respectively by box counting measurement. The results show that the fractal dimension of the projected boundary of carbonylic iron particles is close to smooth curve of one-dimension, while the fractal dimension of the projected boundary of carbonylic nickel particle is close to that of trisection Koch curve, indicating that the shape characteristics of carbonylic nickel particles can be described and analyzed by the characteristics of trisection Koch curve. It is also proposed that the fractal theory can be applied in the research of powder injection molding in four aspects.

  5. Gastroresistant capsular device prepared by injection molding.

    Science.gov (United States)

    Zema, Lucia; Loreti, Giulia; Melocchi, Alice; Maroni, Alessandra; Palugan, Luca; Gazzaniga, Andrea

    2013-01-20

    In the present work, the possibility of manufacturing by injection molding (IM) a gastro-resistant capsular device based on hydroxypropyl methyl cellulose acetate succinate (HPMCAS) was investigated. By performing as an enteric soluble container, such a device may provide a basis for the development of advantageous alternatives to coated dosage forms. Preliminarily, the processability of the selected thermoplastic polymer was evaluated, and the need for a plasticizer (polyethylene glycol 1500) in order to counterbalance the glassy nature of the molded items was assessed. However, some critical issues related to the physical/mechanical stability (shrinkage and warpage) and opening time of the device after the pH change were highlighted. Accordingly, an in-depth formulation study was carried out taking into account differing release modifiers potentially useful for enhancing the dissolution/disintegration rate of the capsular device at intestinal pH values. Capsule prototypes with thickness of 600 and 900 μm containing Kollicoat(®) IR and/or Explotab(®) CLV could be manufactured, and a promising performance was achieved with appropriate gastric resistance in pH 1.2 medium and break-up in pH 6.8 within 1h. These results would support the design of a dedicated mold for the development of a scalable manufacturing process.

  6. Psychodramatic psychotherapy combined with pharmacotherapy in major depressive disorder: an open and naturalistic study Psicoterapia psicodramática combinada ao tratamento medicamentoso no transtorno depressivo maior: um estudo aberto e naturalístico

    Directory of Open Access Journals (Sweden)

    Elisabeth Maria Sene Costa

    2006-03-01

    psicodramática no tratamento do transtorno depressivo maior. O objetivo deste estudo foi o de avaliar o impacto da psicoterapia psicodramática em uma amostra de pacientes com transtorno depressivo maior. MÉTODO: Este estudo constituiu-se de um ensaio clínico controlado, naturalístico, não-randomizado e aberto. Vinte pacientes com transtorno depressivo maior (de acordo com os critérios do DSM-IV, em tratamento farmacológico para depressão, com escores na Escala de Depressão de Hamilton entre 7 e 20 (depressão leve a moderada, foram divididos em dois grupos. Os pacientes do grupo psicoterápico participaram de quatro sessões individuais de psicoterapia psicodramática e 24 sessões de psicoterapia psicodramática em grupo. Os pacientes do grupo controle não participaram de sessões de psicoterapia psicodramática. Ambos os grupos foram avaliados pela Escala de Depressão de Hamilton e pela Escala de Auto-avaliação de Adequação Social. RESULTADOS: Os pacientes que participaram de sessões de psicoterapia psicodramática apresentaram uma melhora significativa nos escores da Escala de Depressão de Hamilton e da Escala de Auto-avaliação de Adequação Social, comparados aos pacientes do grupo controle. CONCLUSÕES: Os resultados sugerem que a psicoterapia psicodramática individual ou em grupo, associada ao tratamento farmacológico, proporciona bons resultados no tratamento do transtorno depressivo maior.

  7. Water modeling of mold powder entrapment in slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The optimal parameters were determined by the water modeling of slab casting. It was found that there are mainly three types of mold powder entrapment in slab continuous casting, i.e., the entrapment caused by the shearing flow near the narrow face of mold, the entrapment caused by vortexes around the submerged entry nozzle (SEN), and the entrapment caused by the Ar bubbling.Both the velocity of the surface flow and the level fluctuation of the liquids are enlarged with increasing the casting speed, reducing the submersion depth of SEN, decreasing the downward angles of the nozzle outlets, and increasing the Ar flowrate, all of which increase the tendency of mold powder entrapment. Among the four above-mentioned factors, casting speed has the largest effect.

  8. Influence of mold surface temperature on polymer part warpage in rapid heat cycle molding

    Science.gov (United States)

    Berger, G. R.; Pacher, G. A.; Pichler, A.; Friesenbichler, W.; Gruber, D. P.

    2014-05-01

    Dynamic mold surface temperature control was examined for its influence on the warpage. A test mold, featuring two different rapid heat cycle molding (RHCM) technologies was used to manufacture complex plate-shaped parts having different ribs, varying thin-wall regions, and both, circular and rectangular cut-outs. The mold's nozzle side is equipped with the areal heating and cooling technology BFMOLD®, where the heating/cooling channels are replaced by a ball-filled slot near the cavity surface flooded through with hot and cold water sequentially. Two local electrical ceramic heating elements are installed into the mold's ejection side. Based on a 23 full-factorial design of experiments (DoE) plan, varying nozzle temperature (Tnozzle), rapid heat cycle molding temperature (TRHCM) and holding pressure (pn), specimens of POM were manufactured systematically. Five specimens were examined per DoE run. The resulting warpage was measured at 6 surface line scans per part using the non-contact confocal topography system FRT MicroProf®. Two warpage parameters were calculated, the curvature of a 2nd order approximation a, and the vertical deflection at the profile center d. Both, the influence strength and the acting direction of the process parameters and their interactions on a and d were calculated by statistical analysis. Linear mathematical process models were determined for a and d to predict the warpage as a function of the process parameter settings. Finally, an optimum process setting was predicted, based on the process models and Microsoft Excel GRG solver. Clear and significant influences of TRHCM, pn, Tnozzle, and the interaction of TRHCM and pn were determined. While TRHCM was dominant close to the gate, pn became more effective as the flow length increased.

  9. Effect of mold treatment by solvent on PDMS molding into nanoholes

    Science.gov (United States)

    Con, Celal; Cui, Bo

    2013-09-01

    Polydimethylsiloxane (PDMS) is the most popular and versatile material for soft lithography due to its flexibility and easy fabrication by molding process. However, for nanoscale patterns, it is challenging to fill uncured PDMS into the holes or trenches on the master mold that is coated with a silane anti-adhesion layer needed for clean demolding. PDMS filling was previously found to be facilitated by diluting it with toluene or hexane, which was attributed to the great reduction of viscosity for diluted PDMS. Here, we suggest that the reason behind the improved filling for diluted PDMS is that the diluent solvent increases in situ the surface energy of the silane-treated mold and thus the wetting of PDMS to the mold surface. We treated the master mold surface (that was already coated with a silane anti-adhesion monolayer) with toluene or hexane, and found that the filling by undiluted PMDS into the nanoscale holes on the master mold was improved despite the high viscosity of the undiluted PDMS. A simple estimation based on capillary filing into a channel also gives a filling time on the millisecond scale, which implies that the viscosity of PMDS should not be the limiting factor. We achieved a hole filling down to sub-200-nm diameter that is smaller than those of the previous studies using regular Sylgard PDMS (not hard PDMS, Dow Corning Corporation, Midland, MI, USA). However, we are not able to explain using a simple argument based on wetting property why smaller, e.g., sub-100-nm holes, cannot be filled, for which we suggested a few possible factors for its explanation.

  10. Three-Dimensional Modeling of Glass Lens Molding

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Hattel, Jesper Henri; Hansen, Hans Nørgaard

    2015-01-01

    The required accuracy for the final dimensions of the molded lenses in wafer-based precision glass molding as well as the need for elimination of costly experimental trial and error calls for numerical simulations. This study deals with 3D thermo-mechanical modeling of the wafer-based precision...... glass lens molding process. First, a comprehensive 3D thermo-mechanical model of glass is implemented into a FORTRAN user subroutine (UMAT) in the FE program ABAQUS, and the developed FE model is validated with both a well-known sandwich seal test and experimental results of precision molding of several...... glass rings. Afterward, 3D thermo-mechanical modeling of the wafer-based glass lens manufacturing is performed to suggest a proper molding program (i.e., the proper set of process parameters including preset force-time and temperature-time histories) for molding a wafer to a desired dimension...

  11. Replication of optical microlens arrays using photoresist coated molds

    DEFF Research Database (Denmark)

    Chakrabarti, Maumita; Dam-Hansen, Carsten; Stubager, Jørgen

    2016-01-01

    A cost reduced method of producing injection molding tools is reported and demonstrated for the fabrication of optical microlens arrays. A standard computer-numerical-control (CNC) milling machine was used to make a rough mold in steel. Surface treatment of the steel mold by spray coating...... the light engine. Polymer injection molded microlens arrays were produced from both the rough and coated molds and have been characterized for lenslet parameters, surface quality, light scattering, and acceptance angle. The surface roughness (Ra) is improved approximately by a factor of two after...... the coating process and the light scattering is reduced so that the molded microlens array can be used for the color mixing application. The measured accepted angle of the microlens array is 40° which is in agreement with simulations....

  12. Validation of three-dimensional micro injection molding simulation accuracy

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F.S.; Hansen, Hans Nørgaard

    2011-01-01

    length, injection pressure profile, molding mass and flow pattern. The importance of calibrated micro molding process monitoring for an accurate implementation strategy of the simulation and its validation has been demonstrated. In fact, inconsistencies and uncertainties in the experimental data must...... be minimized to avoid introducing uncertainties in the simulation calculations. Simulations of bulky sub-100 milligrams micro molded parts have been validated and a methodology for accurate micro molding simulations was established.......Data analysis and simulations on micro-molding experiments have been conducted. Micro molding simulations have been executed taking into account actual processing conditions implementation in the software. Various aspects of the simulation set-up have been considered in order to improve...

  13. Shape retention of injection molded stainless steel compacts

    Institute of Scientific and Technical Information of China (English)

    LI Yi-min; K.A.Khalil; HUANG Bai-yun

    2005-01-01

    The effects of the binder composition, the powder loading, the thermal properties of feedstocks, and the injection molding parameters on the compact shape retention for metal injection molding 17-4PH stainless steel were investigated. The high-density polyethylene is more effective than ethylene vinyl acetate as a second component of the wax-based binder to retain compact shape due to its higher pyrolytic temperature and less heat of fusion. The compact distortion decreases with increasing the powder loading, molding pressure and molding temperature. There exists an optimal process combination including the powder loading of 68%, molding pressure of 120 MPa and molding temperature of 150 ℃. Under this process condition, the percentage of distorted compacts is the lowest.

  14. Mold deformation in soft UV-nanoimprint lithography

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    UV-nanoimprint lithography (UV-NIL) using a soft mold is a promising technique with low cost and high throughput for producing the submicron scale large-area patterns. However, the deformations of the soft mold during imprinting process which can cause serious consequences have to be understood for the practical application of the process. This paper investigated the deformation of the soft mold by theoretical analyses, numerical simulations, and experimental studies. We simulated the mold deformation using a simplified model and finite element method. The simulation and the related experimental results agree well with each other. Through the investigation, the mechanism and affected factors of the mold deformation are revealed, and some useful conclusions have been achieved. These results will be valuable in optimizing the imprinting process conditions and mold design for improving the quality of transferred patterns.

  15. Snow molds: A group of fungi that prevail under snow.

    Science.gov (United States)

    Matsumoto, Naoyuki

    2009-01-01

    Snow molds are a group of fungi that attack dormant plants under snow. In this paper, their survival strategies are illustrated with regard to adaptation to the unique environment under snow. Snow molds consist of diverse taxonomic groups and are divided into obligate and facultative fungi. Obligate snow molds exclusively prevail during winter with or without snow, whereas facultative snow molds can thrive even in the growing season of plants. Snow molds grow at low temperatures in habitats where antagonists are practically absent, and host plants deteriorate due to inhibited photosynthesis under snow. These features characterize snow molds as opportunistic parasites. The environment under snow represents a habitat where resources available are limited. There are two contrasting strategies for resource utilization, i.e., individualisms and collectivism. Freeze tolerance is also critical for them to survive freezing temperatures, and several mechanisms are illustrated. Finally, strategies to cope with annual fluctuations in snow cover are discussed in terms of predictability of the habitat.

  16. Effect of superheat, mold, and casting materials on the metal/mold interfacial heat transfer during solidification in graphite-lined permanent molds

    Science.gov (United States)

    Prabhu, K. Narayan; Suresha, K. M.

    2004-10-01

    Heat transfer during the solidification of an Al-Cu-Si alloy (LM4) and commercial pure tin in single steel, graphite, and graphite-lined metallic (composite) molds was investigated. Experiments were carried out at three different superheats. In the case of composite molds, the effect of the thickness of the graphite lining and the outer wall on heat transfer was studied. Temperatures at known locations inside the mold and casting were used to solve the Fourier heat conduction equation inversely to yield the casting/mold interfacial heat flux transients. Increased melt superheats and higher thermal conductivity of the mold material led to an increase in the peak heat flux at the metal/mold interface. Factorial experiments indicated that the mold material had a significant effect on the peak heat flux at the 5% level of significance. The ratio of graphite lining to outer steel wall and superheat had a significant effect on the peak heat flux in significance range varying between 5 and 25%. A heat flux model was proposed to estimate the maximum heat flux transients at different superheat levels of 25 to 75 °C for any metal/mold combinations having a thermal diffusivity ratio (α R) varying between 0.25 and 6.96. The heat flow models could be used to estimate interfacial heat flux transients from the thermophysical properties of the mold and cast materials and the melt superheat. Metallographic analysis indicated finer microstructures for castings poured at increased melt superheats and cast in high-thermal diffusivity molds.

  17. Diseño y construcción de un molde permanente utilizando un software por elementos finitos Design and construction of a permanent mold using finite element software

    Directory of Open Access Journals (Sweden)

    Fausto Oviedo Fierro

    2013-06-01

    Full Text Available (Recibido: 2012/11/07 - Aceptado: 2013/06/18El proyecto fue desarrollado con especificaciones técnicas de un método de elementos finitospara el cálculo de las variables de campo dentro de un contorno del molde de estudio yeligiendo un modelo matemático apropiado con la incorporación de software. El desarrollo fueuna aplicación físico-practica seleccionando una pieza de aluminio a ser construida, y seanaliza las funciones y solicitaciones a las que está sometida. Se diseña el molde metálico parala producción de las mencionadas piezas con la ayuda del software VULCAN basado en elMétodo de Elementos Finitos (MEF. La simulación se realiza en las tres etapas del proceso defusión: llenado, solidificación y, enfriamiento. En el llenado se considera que existenvelocidades que no produzcan mayores turbulencias y que las piezas se llenen completamente.En la Solidificación se analiza que el sistema de alimentación sea óptimo para que solidifiqueen última instancia y no lo hagan las piezas a producir, evitando así el defecto de falta dematerial en la cavidad del molde (rechupes. En el enfriamiento se analiza la presencia dedeformaciones y tensiones residuales. Paralelamente se validan los resultados de maneraanalítica. Con esta información se define la geometría final del molde metálico y se confirma laaleación con la que se construirá. Posteriormente se utiliza el sistema CAD-CAM-CAE para eldiseño y desarrollo del molde, y así llevar a cabo la construcción. En el molde terminado sevierte la aleación de aluminio seleccionada para obtener las piezas (mancuernas, y finalmenterealizar las pruebas y conclusiones.(Received: 2012/11/07 - Accepted: 2013/06/18The project was developed with specifications of a finite element method for the calculation ofthe field variables within a mold contour by choosing an appropriate mathematical model whichpermitted to incorporate simulation software. The development was a physical

  18. Effect of mold rotation on the bifilar electroslag remelting process

    Science.gov (United States)

    Shi, Xiao-fang; Chang, Li-zhong; Wang, Jian-jun

    2015-10-01

    A novel electroslag furnace with a rotating mold was fabricated, and the effects of mold rotational speed on the electroslag remelting process were investigated. The results showed that the chemical element distribution in ingots became uniform and that their compact density increased when the mold rotational speed was increased from 0 to 28 r/min. These results were attributed to a reasonable mold speed, which resulted in a uniform temperature in the slag pool and scattered the metal droplets randomly in the metal pool. However, an excessive rotational speed caused deterioration of the solidification structure. When the mold rotational speeds was increased from 0 to 28 r/min, the size of Al2O3 inclusions in the electroslag ingot decreased from 4.4 to 1.9 μm. But the excessive mold rotational speed would decrease the ability of the electroslag remelting to remove the inclusions. The remelting speed gradually increased, which resulted in reduced power consumption with increasing mold rotational speed. This effect was attributed to accelerated heat exchange between the consumable electrode and the molten slag, which resulted from mold rotation. Nevertheless, when the rotational speed reached 28 r/min, the remelting speed did not change because of limitations of metal heat conduction. Mold rotation also improved the surface quality of the ingots by promoting a uniform temperature distribution in the slag pool.

  19. Virtual Mold Technique in Thermal Stress Analysis during Casting Process

    Institute of Scientific and Technical Information of China (English)

    Si-Young Kwak; Jae-Wook Baek; Jeong-Ho Nam; Jeong-Kil Choi

    2008-01-01

    It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

  20. Deformation analysis considering thermal expansion of injection mold

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Hyung; Yi, Dae Eun; Jang, Jeong Hui; Lee, Min Seok [Samsung Electronics Co., LTD., Seoul (Korea, Republic of)

    2015-09-15

    In the design of injection molds, the temperature distribution and deformation of the mold is one of the most important parameters that affect the flow characteristics, flash generation, and surface appearance, etc. Plastic injection analyses have been carried out to predict the temperature distribution of the mold and the pressure distribution on the cavity surface. As the input loads, we transfer the temperature and pressure results to the structural analysis. We compare the structural analysis results with the thermal expansion effect using the actual flash and step size of a smartphone cover part. To reduce the flash problem, we proposed a new mold design, and verified the results by performing simulations.

  1. A hybrid optimization approach in non-isothermal glass molding

    Science.gov (United States)

    Vu, Anh-Tuan; Kreilkamp, Holger; Krishnamoorthi, Bharathwaj Janaki; Dambon, Olaf; Klocke, Fritz

    2016-10-01

    Intensively growing demands on complex yet low-cost precision glass optics from the today's photonic market motivate the development of an efficient and economically viable manufacturing technology for complex shaped optics. Against the state-of-the-art replication-based methods, Non-isothermal Glass Molding turns out to be a promising innovative technology for cost-efficient manufacturing because of increased mold lifetime, less energy consumption and high throughput from a fast process chain. However, the selection of parameters for the molding process usually requires a huge effort to satisfy precious requirements of the molded optics and to avoid negative effects on the expensive tool molds. Therefore, to reduce experimental work at the beginning, a coupling CFD/FEM numerical modeling was developed to study the molding process. This research focuses on the development of a hybrid optimization approach in Non-isothermal glass molding. To this end, an optimal configuration with two optimization stages for multiple quality characteristics of the glass optics is addressed. The hybrid Back-Propagation Neural Network (BPNN)-Genetic Algorithm (GA) is first carried out to realize the optimal process parameters and the stability of the process. The second stage continues with the optimization of glass preform using those optimal parameters to guarantee the accuracy of the molded optics. Experiments are performed to evaluate the effectiveness and feasibility of the model for the process development in Non-isothermal glass molding.

  2. Moldagem por injeção da PA 6.6 em moldes de estereolitografia metalizados com Ni-P pelo processo electroless Injection molding of PA 6.6 in stereolithography moulds coated with electroless Ni-P

    Directory of Open Access Journals (Sweden)

    Diovani C. Lencina

    2007-06-01

    Full Text Available A fabricação de moldes por técnicas de prototipagem rápida, como a estereolitografia (SL, é considerada uma importante tecnologia no auxílio ao desenvolvimento de produtos de plástico moldados por injeção. Embora esta tecnologia se mostre vantajosa, a vida útil dos moldes pode ser bastante reduzida em decorrência, por exemplo, de forte adesão entre o polímero injetado e o material do molde SL. Neste trabalho é investigado o uso da técnica de recobrimento metálico com Ni-P por deposição electroless sobre moldes de injeção, fabricados por SL com a resina DSM SOMOS 7110®. Foram comparados resultados de moldagem de PA6.6 em moldes fabricados com e sem recobrimento metálico evidenciando a possibilidade de utilizar a técnica de metalização como alternativa para a moldagem deste material em moldes SL, uma vez que a vida útil foi superior.Manufacturing of moulds by rapid prototyping processes, such as stereolithography (SL, is considered an important technology to aid the development of injection moulding plastic products. Although this technology shows significant advantages, the lifetime of moulds may be drastically be reduced due to strong adhesion between the injected polymer and the material of the SL mould. This work investigates the use of Ni-P metal coating obtained by electroless deposition on SL moulds manufactured with the resin DSM SOMOS 7110. Specimens of PA6.6 have been injected into SL moulds manufactured with and without metal coating. The results showed that the electroless metal coating process can be an appropriate alternative to allow moulding of small series of PA6.6 parts in SL moulds.

  3. Mold Filling Analysis in Vacuum Infusion Molding Process Based on a High-Permeable Medium

    Institute of Scientific and Technical Information of China (English)

    Yingdan ZHU; Hua TAN; Jihui WANG

    2003-01-01

    The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulate the moldingprocess, and the simulation results show good agreement with experiments.

  4. Injection-molded capsular device for oral pulsatile release: development of a novel mold.

    Science.gov (United States)

    Zema, Lucia; Loreti, Giulia; Macchi, Elena; Foppoli, Anastasia; Maroni, Alessandra; Gazzaniga, Andrea

    2013-02-01

    The development of a purposely devised mold and a newly set up injection molding (IM) manufacturing process was undertaken to prepare swellable/erodible hydroxypropyl cellulose-based capsular containers. When orally administered, such devices would be intended to achieve pulsatile and/or colonic time-dependent delivery of drugs. An in-depth evaluation of thermal, rheological, and mechanical characteristics of melt formulations/molded items made of the selected polymer (Klucel® LF) with increasing amounts of plasticizer (polyethylene glycol 1500, 5%-15% by weight) was preliminarily carried out. On the basis of the results obtained, a new mold was designed that allowed, through an automatic manufacturing cycle of 5 s duration, matching cap and body items to be prepared. These were subsequently filled and coupled to give a closed device of constant 600 μm thickness. As compared with previous IM systems having the same composition, such capsules showed improved closure mechanism, technological properties, especially in terms of reproducibility of the shell thickness, and release performance. Moreover, the ability of the capsular container to impart a constant lag phase before the liberation of the contents was demonstrated irrespective of the conveyed formulation.

  5. Investigations on injection molded, glass-fiber reinforced polyamide 6 integral foams using breathing mold technology

    Science.gov (United States)

    Roch, A.; Kehret, L.; Huber, T.; Henning, F.; Elsner, P.

    2015-05-01

    Investigations on PA6-GF50 integral foams have been carried out using different material systems: longfiber- and shortfiber-reinforced PA6 as well as unreinforced PA6 as a reference material. Both chemical and physical blowing agents were applied. Breathing mold technology (decompression of the mold) was selected for the foaming process. The integral foam design, which can be conceived as a sandwich structure, helps to save material in the neutral axis area and maintains a distance between load-bearing, unfoamed skin layers. For all test series an initial mold gap of 2.5 mm was chosen and the same amount of material was injected. In order to realize different density reductions, the mold opening stroke was varied. The experiments showed that, at a constant mass per unit area, integral polyamide 6 foams have a significantly higher bending stiffness than compact components, due to their higher area moment of inertia after foaming. At a constant surface weight the bending stiffness in these experiments could be increased by up to 600 %. Both shortfiber- and longfiber-reinforced polyamide 6 showed an increase in energy absorption during foaming.

  6. Open Access Serials: the High Dilution Research case. Publicaciones de acceso abierto: el caso de la investigación en altas diluciones Publicações de acesso aberto: o caso da pesquisa em altas diluições

    Directory of Open Access Journals (Sweden)

    Carlos Renato Zacharias

    2008-09-01

    ático, revisado por pares e de fácil acesso, capaz de alcançar parâmetros de alto impacto sem perder seu foco, onde os marcos de referência e conceitos teóricos possam ser apresentados e intensamente discutidos, abarcando do experimental ao teórico, pesquisa básica e aplicada, pesquisas clínicas, históricas e sociológicas. As características do sistema aberto se correspondem adequadamente com os requerimentos de um periódico para a comunidade ligada às altas diluições. Igualmente, o meio eletrônico permite divulgar textos e gráficos de maior tamanho, filmes, entrevistas, áudio e outros tipos de formatos multimedia. Por esse motivo, um periódico científico de acesso aberto dedicado às altas diluições seria muito bem recebido pela comunidade internacional. Palavras-chave: Acesso aberto, altas diluições, periódicos online.   Publicaciones de acceso abierto: el caso de la investigación en altas diluciones Resumen La publicación de acceso abierto parece ser el nuevo paradigma en publicación científica, representando una tendencia creciente en todos los segmentos de la sociedad. En particular, nos interesa la aplicación de este modelo en la investigación de altas diluciones. Tal área multidisciplinar está abierta a especialistas de todas las áreas del saber, necesitando aún ensayos y modelos experimentales, así como abordajes teóricos. Sin embargo, estos investigadores deben ser reunidos en torno de un periódico temático, revisado por pares y de fácil acceso, capaz de alcanzar parámetros de alto impacto sin perder su foco, adonde los marcos de referencia y conceptos teóricos puedan ser presentados e intensamente discutidos, abarcando desde lo experimental a lo te

  7. Taxonomy Icon Data: koji mold [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available koji mold Aspergillus oryzae Aspergillus_oryzae_L.png Aspergillus_oryzae_NL.png Aspergillus_oryzae_S.png Asp...ergillus_oryzae_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aspergillus...+oryzae&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aspergillus+oryzae&t=NL http://biosciencedbc.jp.../taxonomy_icon/icon.cgi?i=Aspergillus+oryzae&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aspergil...lus+oryzae&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=63 ...

  8. The flexible resin transfer molding (FRTM) process

    Science.gov (United States)

    Foley, Michael F.

    1992-12-01

    An innovative composite manufacturing process, FRTM, which is based on detailed cost analysis intended to be 'cost effective by design', is described. FRTM is based on a combination of the technical characteristics and respective favorable economics of diaphragm forming, and resin transfer molding. The process control system determines the optimal time for compaction and forming using an empirical resin polymerization model, a fluid flow model, and dielectric sensing of in-situ resin properties. The modified FRTM process is capable of producing high-quality parts with low thickness variation, low void content, and high fiber volume.

  9. Characteristics and infl uence factors of mold fi lling process in permanent mold with a slot gating system

    OpenAIRE

    2009-01-01

    The main problems caused by improper gating are entrained aluminum oxide fi lms and entrapped gas. In this study, the slot gating system is employed to improve mold fi lling behavior and therefore, to improve the quality of aluminum castings produced in permanent molds. An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum fl owing into permanent molds have been developed. Graphite molds transparent to X-rays are utilized which make it possible to obs...

  10. Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography

    Science.gov (United States)

    Bae, Chang-Jun

    Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to

  11. Rotational molding of bio-polymers

    Science.gov (United States)

    Greco, Antonio; Maffezzoli, Alfonso; Forleo, Stefania

    2014-05-01

    This paper is aimed to study the suitability of bio-polymers, including poly-lactic acid (PLLA) and Mater-Bi, for the production of hollow components by rotational molding. In order to reduce the brittleness of PLLA, the material was mixed with two different plasticizers, bis-ethyl-hexyl-phthalate (DEHP) and poly-ethylene-glycol (PEG). The materials were characterized in terms of sinterability. To this purpose, thermomechanical (TMA) analysis was performed at different heating rates, in order to identify the endset temperatures of densification and the onset temperatures of degradation. Results obtained indicated that the materials are characterized by a very fast sintering process, occurring just above the melting temperature, and an adequately high onset of degradation. The difference between the onset of degradation and the endset of sintering, defined as the processing window of the polymer, is sufficiently wide, indicating that the polymers can be efficiently processed by rotational molding. Therefore, a laboratory scale apparatus was used for the production of PLLA and Mater-Bi prototypes. The materials were processed using very similar conditions to those used for LLDPE. The production of void-free samples of uniform wall thickness was considered as an indication of the potentiality of the process for the production of biodegradable containers.

  12. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, G.M.; Domeier, L.A.

    1996-04-01

    The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

  13. Lighting molded optics: Design and manufacturing

    Directory of Open Access Journals (Sweden)

    Kočárková H.

    2013-05-01

    Full Text Available Proper design and manufacturing of glass molded lenses need to be performed in several steps. The whole process from customer requirements to f nal functional product is shown on two examples - a lens for street light and a lens for spot light with narrow lighting angle. After discussing customer requirements, optical design is made. Thanks to various commercial softwares with optimization, manufacturer of the lens can work as well as a designer which enables simplif cation and acceleration of lens manufacturing, since limitations of the manufacturing process are considered during creation of the design. When the prototype is made, its functionality needs to be evaluated. This work shows measurement of light distribution for street light lens in a dark room using goniometer and measurement of light intensity for spot lens f xed on an optical bench. These measurements can reveal the root cause in case of lens malfunction, which enables to optimize manufacturing process or modify lens design accordingly. Designing, manufacturing and evaluation of molded optics under one roof enables creation of easily manufacturable design and fast solution of problems.

  14. Production of Liquid Metal Spheres by Molding

    Directory of Open Access Journals (Sweden)

    Mohammed G. Mohammed

    2014-10-01

    Full Text Available This paper demonstrates a molding technique for producing spheres composed of eutectic gallium-indium (EGaIn with diameters ranging from hundreds of microns to a couple millimeters. The technique starts by spreading EGaIn across an elastomeric sheet featuring cylindrical reservoirs defined by replica molding. The metal flows into these features during spreading. The spontaneous formation of a thin oxide layer on the liquid metal keeps the metal flush inside these reservoirs. Subsequent exposure to acid removes the oxide and causes the metal to bead up into a sphere with a size dictated by the volume of the reservoirs. This technique allows for the production and patterning of droplets with a wide range of volumes, from tens of nanoliters up to a few microliters. EGaIn spheres can be embedded or encased subsequently in polymer matrices using this technique. These spheres may be useful as solder bumps, electrodes, thermal contacts or components in microfluidic devices (valves, switches, pumps. The ease of parallel-processing and the ability to control the location of the droplets during their formation distinguishes this technique.

  15. Sinterability of Zirconia Top Coat of Investment Mold for Ti Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, zirconia is used as top mold material for Ti investment casting. Top mold samples are made by proper mold building technology. The effect of different sintering temperature on chemical composition, microstructure and residual bending strength of the top mold sample is studied. The volume and homogeneity of the air holes in the top mold are determined by sintering temperature, and finally determined the residual bending strength of the mold sample was determined.

  16. Development of the computer-aided process planning (CAPP) system for polymer injection molds manufacturing

    OpenAIRE

    J. Tepić; V. Todić; Lukić, D.; Milošević, M.; Borojević, S.

    2011-01-01

    Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-...

  17. Taxonomic re-evaluation of black koji molds

    NARCIS (Netherlands)

    Hong, S.B.; Yamada, O.; Samson, R.A.

    2013-01-01

    Black koji molds including its albino mutant, the white koji mold, have been widely used for making the distilled spirit shochu in Northeast Asia because they produce citric acid which prevents undesirable contamination from bacteria. Since Inui reported Aspergillus luchuensis from black koji in Oki

  18. Taxonomic re-evaluation of black koji molds

    NARCIS (Netherlands)

    Hong, S.B.; Yamada, O.; Samson, R.A.

    2013-01-01

    Black koji molds including its albino mutant, the white koji mold, have been widely used for making the distilled spirit shochu in Northeast Asia because they produce citric acid which prevents undesirable contamination from bacteria. Since Inui reported Aspergillus luchuensis from black koji in

  19. Multi-height structures in injection molded polymer

    DEFF Research Database (Denmark)

    Andersen, Nis Korsgaard; Taboryski, Rafael J.

    2015-01-01

    We present the fabrication process for injection molded multi-height surface structures for studies of wetting behavior. We adapt the design of super hydrophobic structures to the fabrication constrictions imposed by industrial injection molding. This is important since many super hydrophobic sur...

  20. A fabrication method of microneedle molds with controlled microstructures.

    Science.gov (United States)

    Wang, Qi Lei; Zhu, Dan Dan; Chen, Yang; Guo, Xin Dong

    2016-08-01

    Microneedle (MN) offers an attractive, painless and minimally invasive approach for transdermal drug delivery. Polymer microneedles are normally fabricated by using the micromolding method employing a MN mold, which is suitable for mass production due to high production efficiency and repeat-using of the mold. Most of the MN molds are prepared by pouring sylgard polymer over a MN master to make an inverse one after curing, which is limited in optimizing or controlling the MN structures and failing to keep the sharpness of MNs. In this work we describe a fabrication method of MN mold with controlled microstructures, which is meaningful for the fabrication of polymer MNs with different geometries. Laser micro-machining method was employed to drill on the surface of PDMS sheets to obtain MN molds. In the fabrication process, the microstructures of MN molds are precisely controlled by changing laser parameters and imported patterns. The MNs prepared from these molds are sharp enough to penetrate the skin. This scalable MN mold fabrication method is helpful for future applications of MNs.

  1. Evaluation of Additive Manufacturing for High Volume Composite Part Molds

    Energy Technology Data Exchange (ETDEWEB)

    Duty, Chad E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kunc, Vlastimil [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lokitz, Bradley S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Springfield, Robert M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-01

    ORNL worked with TruDesign, LLC to develop viable coating solutions to enable the use of large scale 3D printing for both low-temperature and high-temperature composite molds. This project resulted in two commercial products and successfully demonstrated the use of printed molds for autoclave processing for the first time.

  2. Effect of processing conditions on shrinkage in injection molding

    NARCIS (Netherlands)

    Jansen, K.M.B.; Dijk, van D.J.; Husselman, M.H.

    1998-01-01

    A systematic study on the effect of processing conditions on mold shrinkage was undertaken for seven common thermoplastic polymers. It turned out that the holding pressure was always the key parameter. The effect of the melt temperature is slightly less important. Injection velocity and mold tempera

  3. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phenolic resins in molded articles. 177.2410... as Components of Articles Intended for Repeated Use § 177.2410 Phenolic resins in molded articles. Phenolic resins identified in this section may be safely used as the food-contact surface of...

  4. Vacuum Infusion Molding Process (Part 2 VIMP Based on Grooves)

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying-dan; DENG Jing-lan; WANG Ji-hui; TAN Hua

    2003-01-01

    The optimal parameters for flow grooves and supply grooves were determined by a series of experiments , and the influences of various molding conditions on the mold filling process were analyzed. Furthermore ,the whole VIMP procedure based on grooves was introduced in detail taking the manufacture of a sandwich panel as an example.

  5. Bestrijden en voorkomen van de oculatieschimmel Black Mold in roos

    NARCIS (Netherlands)

    Werd, de H.A.E.; Breeuwsma, S.J.; Meijer, H.; Wijk, van D.; Pijpers, H.

    2008-01-01

    Black Mold veroorzaakt afsterving van jonge oculaties in de teelt van rozenstruiken. Middels een enquête onder telers, een korte literatuurstudie en infectieproeven is een inventariserend onderzoek gedaan naar de factoren die het optreden van Black Mold beïnvloeden. Op basis van de infectieproeven i

  6. ASTHMATIC HUMAN SERUM IGE-REACTIVITY WITH MOLD EXTRACTS

    Science.gov (United States)

    Although molds have demonstrated the ability to induce allergic asthma-like responses in mouse models, their role in human disease is unclear. This study was undertaken to provide insight into the prevalence of human IgE-reactivity and identify the target mold protein(s). The st...

  7. IGE IN ASTHMATIC HUMAN SERA IS REACTIVE AGAINST MOLD EXTRACTS

    Science.gov (United States)

    Molds have been associated with various health effects including asthma, but their role in induction of asthma is unclear. However, the presence of mold-specific IgE indicates their capacity to induce allergic responses and possibly exacerbate asthma symptoms. This study was und...

  8. Optimization of Mold Yield in MultiCavity Sand Castings

    Science.gov (United States)

    Shinde, Vasudev D.; Joshi, Durgesh; Ravi, B.; Narasimhan, K.

    2013-06-01

    The productivity of ductile iron foundries engaging in mass production of castings for the automobile and other engineering sectors depends on the number of cavities per mold. A denser packing of cavities, however, results in slower heat transfer from adjacent cavities, leading to delayed solidification, possible shrinkage defects, and lower mechanical properties. In this article, we propose a methodology to optimize mold yield by selecting the correct combination of the mold box size and the number of cavities based on solidification time and mold temperature. Simulation studies were carried out by modeling solid and hollow cube castings with different values of cavity-wall gap and finding the minimum value of the gap beyond which there is no change in casting solidification time. Then double-cavity molds were modeled with different values of cavity-cavity gap, and simulated to find the minimum value of gap. The simulation results were verified by melting and pouring ductile iron in green sand molds instrumented with thermocouples, and recording the temperature in mold at predetermined locations. The proposed approach can be employed to generate a technological database of minimum gaps for various combinations of part geometry, metal and process, which will be very useful to optimize the mold cavity layouts.

  9. Mold Flora of Traditional Cheeses Produced in Turkey

    Directory of Open Access Journals (Sweden)

    Musa Yalman

    2016-11-01

    Full Text Available In our country, there are many cheese types that are produced traditionally. Cheeses which produced from cows, sheep and goat milk that matured with spontaneous growth of molds present in livestock skins, pots and similar environments are among them. They are produced traditionally in Mediterrian, Central and Eastern Anatolia regions. Molds that grow spontaneously in cheeses could create public health risk because of their secondary metabolites. Penicillium spp. are the most isolated mold from these cheeses and Penicillium roqueforti is determined as the dominant species. Furthermore, Aspergillus, Alternaria, Mucor, Geotrichum, Cladosporium species have been isolated. It is very important to control the ripening conditions and starter strain selection since some strains were reported as mycotoxin producers. In this review, it has been tried to give general information about traditional production of mold-ripened cheese in Turkey and the mold flora found in traditional cheeses. In addition, public health risk of these cheeses is reported.

  10. THE DURABILITY OF LARGE-SCALE ADDITIVE MANUFACTURING COMPOSITE MOLDS

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K [ORNL; Love, Lonnie J [ORNL; Duty, Chad [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Vaidya, Uday [University of Tennessee, Knoxville (UTK); Pipes, R. Byron [Purdue University; Kunc, Vlastimil [ORNL

    2016-01-01

    Oak Ridge National Laboratory s Big Area Additive Manufacturing (BAAM) technology permits the rapid production of thermoplastic composite molds using a carbon fiber filled Acrylonitrile-Butadiene-Styrene (ABS) thermoplastic. Demonstration tools (i.e. 0.965 m X 0.559 m X 0.152 m) for composite part fabrication have been printed, coated, and finished with a traditional tooling gel. We present validation results demonstrating the stability of thermoplastic printed molds for room temperature Vacuum Assisted Resin Transfer Molding (VARTM) processes. Arkema s Elium thermoplastic resin was investigated with a variety of reinforcement materials. Experimental results include dimensional characterization of the tool surface using laser scanning technique following demolding of 10 parts. Thermoplastic composite molds offer rapid production compared to traditionally built thermoset molds in that near-net deposition allows direct digital production of the net geometry at production rate of 45 kg/hr.

  11. Injection-molded nanocomposites and materials based on wheat gluten.

    Science.gov (United States)

    Cho, S-W; Gällstedt, M; Johansson, E; Hedenqvist, M S

    2011-01-01

    This is, to our knowledge, the first study of the injection molding of materials where wheat gluten (WG) is the main component. In addition to a plasticizer (glycerol), 5 wt.% natural montmorillonite clay was added. X-ray indicated intercalated clay and transmission electron microscopy indicated locally good clay platelet dispersion. Prior to feeding into the injection molder, the material was first compression molded into plates and pelletized. The filling of the circular mold via the central gate was characterized by a divergent flow yielding, in general, a stronger and stiffer material in the circumferential direction. It was observed that 20-30 wt.% glycerol yielded the best combination of processability and mechanical properties. The clay yielded improved processability, plate homogeneity and tensile stiffness. IR spectroscopy and protein solubility indicated that the injection molding process yielded a highly aggregated structure. The overall conclusion was that injection molding is a very promising method for producing WG objects.

  12. Standard Molded Composite Rocket Pyrogen Igniter - A progress report

    Science.gov (United States)

    Lucy, M. H.

    1978-01-01

    The pyrogen igniter has the function to furnish a controlled, high temperature, high pressure gas to ignite solid propellant surfaces in a rocket motor. Present pyrogens consist of numerous inert components. The Standard Molded Pyrogen Igniter (SMPI) consists of three basic parts, a cap with several integrally molded features, an ignition pellet retainer plate, and a tube with additional integrally molded features. A description is presented of an investigation which indicates that the SMPI concept is a viable approach to the design and manufacture of pyrogen igniters for solid propellant rocket motors. For some applications, combining the structural and thermal properties of molded composites can result in the manufacture of lighter assemblies at considerable cost reduction. It is demonstrated that high strength, thin walled tubes with high length to diameter ratios can be fabricated from reinforced plastic molding compound using the displacement compression process.

  13. Injection molding of bushes made of tribological PEEK composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available Polyetheretherketone (PEEK composites have been extensively studied because of the excellent tribological behavior among plastics. However, laboratory specimens and tests are generally discussed, whereas application studies on industrial components are infrequent. In this paper, an injection molded bush made of tribological PEEK was analyzed to correlate wear behavior and molded material structure. Bushes were tested under unlubricated sliding conditions by means of a short wear test. Surface analysis, differential scanning calorimetry (DSC and optical microscopy were used to evaluate the distribution of the different composite fillers (polytetrafluoroethylene, PTFE, graphite particles and carbon microfibers and their effect on the final bush behavior. A significant lack of homogeneity was observed in the molded bush and black bands appeared on the shaft surface after testing due to the sliding. The bush geometry and the injection molding process should be optimized to allow the best tribological behavior of the molded material under working conditions.

  14. The Facility and Process Technics of Polyethylene Rotational Molding

    Institute of Scientific and Technical Information of China (English)

    LI; BaiShun

    2001-01-01

    1. Introduction Rotational molding is the process by which hollow plastic parts are formed. It mainly processes the product which Injection molding and Blow molding can not process medium-sized, large-sized and super large-sized plastic parts. The technics may turn out a tub, dustbin, stock tank, sailboat.  The research institute of Lanzhou introduces a suit of RS-16 Rotational Molding Machine from Germany Reinhadt Co. on 1990. It mainly put up experiment and smallscale production. RS-16 rotational molding machine is a single arm and di-axial equipment. It is consisting of a gas heated sintering oven, cooling chamber, mouldcarrying carriage and a controlling unit.  ……

  15. Mathematical modeling of the in-mold coating process for injection-molded thermoplastic parts

    Science.gov (United States)

    Chen, Xu

    In-Mold Coating (IMC) has been successfully used for many years for exterior body panels made from compression molded Sheet Molding Compound (SMC). The coating material is a single component reactive fluid, designed to improve the surface quality of SMC moldings in terms of functional and cosmetic properties. When injected onto a cured SMC part, IMC cures and bonds to provide a pain-like surface. Because of its distinct advantages, IMC is being considered for application to injection molded thermoplastic parts. For a successful in mold coating operation, there are two key issues related to the flow of the coating. First, the injection nozzle should be located such that the thermoplastic substrate is totally covered and the potential for air trapping is minimized. The selected location should be cosmetically acceptable since it most likely will leave a mark on the coated surface. The nozzle location also needs to be accessible for easy of maintenance. Secondly, the hydraulic force generated by the coating injection pressure should not exceed the available clamping tonnage. If the clamping force is exceeded, coating leakage will occur. In this study, mathematical models for IMC flow on the compressible thermoplastic substrate have been developed. Finite Difference Method (FDM) is first used to solve the 1 dimensional (1D) IMC flow problem. In order to investigate the application of Control Volume based Finite Element Method (CV/FEM) to more complicated two dimensional IMC flow, that method is first evaluated by solving the 1D IMC flow problem. An analytical solution, which can be obtained when a linear relationship between the coating thickness and coating injection pressure is assumed, is used to verify the numerical results. The mathematical models for the 2 dimensional (2D) IMC flow are based on the generalized Hele-Shaw approximation. It has been found experimentally that the power law viscosity model adequately predicts the rheological behavior of the coating

  16. Public health and economic impact of dampness and mold

    Energy Technology Data Exchange (ETDEWEB)

    Mudarri, David; Fisk, William J.

    2007-06-01

    The public health risk and economic impact of dampness and mold exposures was assessed using current asthma as a health endpoint. Individual risk of current asthma from exposure to dampness and mold in homes from Fisk et al. (2007), and asthma risks calculated from additional studies that reported the prevalence of dampness and mold in homes were used to estimate the proportion of U.S. current asthma cases that are attributable to dampness and mold exposure at 21% (95% confidence internal 12-29%). An examination of the literature covering dampness and mold in schools, offices, and institutional buildings, which is summarized in the appendix, suggests that risks from exposure in these buildings are similar to risks from exposures in homes. Of the 21.8 million people reported to have asthma in the U.S., approximately 4.6 (2.7-6.3) million cases are estimated to be attributable to dampness and mold exposure in the home. Estimates of the national cost of asthma from two prior studies were updated to 2004 and used to estimate the economic impact of dampness and mold exposures. By applying the attributable fraction to the updated national annual cost of asthma, the national annual cost of asthma that is attributable to dampness and mold exposure in the home is estimated to be $3.5 billion ($2.1-4.8 billion). Analysis indicates that exposure to dampness and mold in buildings poses significant public health and economic risks in the U.S. These findings are compatible with public policies and programs that help control moisture and mold in buildings.

  17. CENTRAL CONVEYING & AUTO FEEDING SYSTEMS FOR AN INJECTION MOLDING SHOP

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2011-08-01

    Full Text Available Nowadays injection molding is probably the most important method of Processing of consumer and industrial goods, and is performed everywhere in the world. The developing of injection molding becomes a competition from day to day. This Process now integrated with computer control make the production better in quality and Better quantity. The trends of producing a plastics product in injection molding industries are recently changing from traditional method to using the FEA analysis. For injection molding industries, time and cost is very important aspects to consider because these two aspectswill directly related to the profits at a company. The next issue toconsider, to get the best parameter for the injection molding process, plastics has been waste. Through the experiment, operator will use large amount of plastics material to get the possibly parameters to setup the machine.To produce the parts with better quality and quantity these molding defects are the major obstacles in achieving the targets with quality & quantity. Various defects like Short shot, colour streaks and low productivity rates are associated with the material mixing and feeding as molded plastics are often a blend of two or more materials. Colors (master batch and other additives are often mixed (blended with the raw plastic material prior to the molding process in molding plants. So it is very necessary to work out auto blending and auto feeding of plasticgranules to the machine hopper. This paper will cover the studyof automatic blending unit & central conveying system for plasticgranule feeding to machine & will help in optimizing the injection molding process.

  18. Percepção da aplicação tópica ocular de drogas: comparação entre instilação de gotas em olhos abertos e vaporização em olhos fechados

    Directory of Open Access Journals (Sweden)

    Arlindo José Freire Portes

    2014-04-01

    Full Text Available Objetivo: Avaliar por questionário qual o nível de facilidade ou dificuldade para aplicação tópica de medicações oculares: vaporização em olho fechado ou instilação de gotas em olho aberto e constatar por meio da observação de pacientes pelos autores qual o método que foi utilizado com maior adequação técnica para aplicação de drogas tópicas oculares. Métodos: A pesquisa foi um ensaio clínico pareado e randomizado, realizada nos meses de agosto e setembro de 2012 no ambulatório de Oftalmologia da Policlínica Ronaldo Gazolla (Campus Arcos da Lapa, Faculdade de Medicina da Universidade Estácio de Sá, RJ em 50 pacientes conveniados de planos de saúde ou do SUS. Foi utilizado um frasco de colírio e um de vaporizador com solução Optive®. Cada participante aplicou em um dos olhos a solução por vaporização ou instilação de gotas através de um processo randomizado. Foi perguntado aos pacientes questões pré-formuladas sobre a praticidade de ambos os métodos e observada à técnica de aplicação. Resultados: 32% acharam difícil ou muito difícil a vaporização em olho fechado e 34% a instilação de colírio (p=0,9562. A dificuldade mais comum para ambos os métodos foi "acertar o olho" e ocorreu em 53% dos pacientes que tiveram dificuldades para vaporização e por 65%dos que apresentaram dificuldade para aplicação de colírio. 38% dos pacientes necessitaram de mais de uma instilação para aplicação do colírio, enquanto 30% dos pacientes precisaram de mais de uma aplicação para que a droga vaporizada tivesse contato com o olho (p=0,5224. Em 74% dos pacientes houve toque da ponta do colírio com os cílios, já com o vaporizador não houve um toque do orifício do vaporizador com o dedo do paciente (p=0,5433. Conclusão: A maior facilidade ou dificuldade percebida pelos pacientes foi equivalente para instilar o colírio em relação à vaporização em olho fechado. O método da vaporização foi

  19. Specific mold filling characteristics of highly filled phenolic injection molding compounds

    OpenAIRE

    Scheffler, Thomas; Englich, Sascha; Gehde, Michael

    2016-01-01

    Thermosets show excellent mechanical properties and chemical resistance (for most automotive fluids) even at high temperatures up to 300 °C. Furthermore they can be highly efficient processed by injection molding. So they should be particularly suited for e.g. under the bonnet applications. However, the reality shows that thermosets are, except fiber reinforced composites, heavily underrepresented in technical applications. E.g. thermosetting components only account 0,2 % to a vehicle’s weigh...

  20. Star Mapping with Slime Mold Physarum Polycephalum

    Science.gov (United States)

    Mihklepp, M.; Domnitch, E.; Gelfand, D.; Foing, B. H.; van der Heide, E.

    2014-04-01

    Human curiosity and exploration towards outer space has led to many fantastic inventions and given way to alternative scenarios about the origins of life. In the Space Science in the Arts course together with ESTEC with support from ILEWG. I got interested about unicellular slime mold Physarum polycephalum. There has been and still is a lot of research on Physarum polycephalum. This brainless eucaryotic microbe has its smartness and external memory strategies. Physarum can navigate through a maze made of agar using the shortest route possible when two pieces of food are placed at two separate exits of the maze. It can build efficient networks - Physarum created network similar to the existing Tokyo train system. It is being used to control a robot, in USB-sensor and in sound synthesis. Right now there is a lot of research about using Physarum in bio-computing.

  1. Double blind placebo controlled exposure to molds

    DEFF Research Database (Denmark)

    Meyer, H W; Jensen, K A; Nielsen, K F

    2005-01-01

    with a positive histamine release test to Penicillium chrysogenum were exposed double- blinded to either placebo, approximately 600,000 spores/m3 air of P. chrysogenum or approximately 350,000 spores/m3 of Trichoderma harzianum for 6 min on three separate days. A statistically significant rise in symptoms from...... mucous membranes appeared from the 9-graded symptom scale after exposure to T. harzianum or placebo. Dichotomizing the data, whether the participants experienced at least a two-step rise on the symptom scale or not, gave borderline increase in mucous membrane symptoms after exposure to P. chrysogenum...... to placebo in eight sensitive school employees. However, a statistical type II error cannot be excluded because of the small sample size. PRACTICAL IMPLICATIONS: In this double blind, placebo controlled study of mold exposure changes in symptoms, objective measurements and blood samples were small and mostly...

  2. Ozone reaction on slime mold. [Physarum polycephalum

    Energy Technology Data Exchange (ETDEWEB)

    Kanoh, F.

    1972-01-01

    To determine the effect of ozone, the motive force responsible for protoplasmic streaming in the slime mold, Physarum polycephalum was measured by the Double chamber method which was developed by Kamiya. The effects of ozone on the motive force were investigated by comparison of the Dynamoplasmogram of controls with that of ozone exposure. In the case of high concentration exposure, thickening of plasmagel, inversion of the period of flow and reduction of the extreme point were observed. Succinoxidase of exposed homogenates showed stronger activity than that of controls. It is certain that the Pasteur reaction takes place when plasmodium is kept under high ozone exposure condition. It appears that ozone inhibited a part of the process of glycolysis. 32 references, 8 figures.

  3. IMAGE ANALYSIS DEDICATED TO POLYMER INJECTION MOLDING

    Directory of Open Access Journals (Sweden)

    David Garcia

    2011-05-01

    Full Text Available This work follows the general framework of polymer injection moulding simulation whose objectives are the mastering of the injection moulding process. The models of numerical simulation make it possible to predict the propagation of the molten polymer during the filling phase from the positioning of one point of injection or more. The objective of this paper is to propose a particular way to optimize the geometry of mold cavity in accordance with physical laws. A direct correlation is pointed out between geometric parameters issued from skeleton transformation and Hausdorff's distance and results provided by implementation of a classical model based on the Hele-Shaw equations which are currently used in the main computer codes of polymer injection.

  4. Review of small aspheric glass lens molding technologies

    Science.gov (United States)

    Yin, Shaohui; Jia, Hongpeng; Zhang, Guanhua; Chen, Fengjun; Zhu, Kejun

    2017-01-01

    Aspheric lens can eliminate spherical aberrations, coma, astigmatism, field distortions, and other adverse factors. This type of lens can also reduce the loss of light energy and obtain high-quality images and optical characteristics. The demand for aspheric lens has increased in recent years because of its advantageous use in the electronics industry, particularly for compact, portable devices and high-performance products. As an advanced manufacturing technology, the glass lens molding process has been recognized as a low-cost and high-efficiency manufacturing technology for machining small-diameter aspheric lens for industrial production. However, the residual stress and profile deviation of the glass lens are greatly affected by various key technologies for glass lens molding, including glass and mold-die material forming, mold-die machining, and lens molding. These key technical factors, which affect the quality of the glass lens molding process, are systematically discussed and reviewed to solve the existing technical bottlenecks and problems, as well as to predict the potential applicability of glass lens molding in the future.

  5. Indoor mold, toxigenic fungi, and Stachybotrys chartarum: infectious disease perspective.

    Science.gov (United States)

    Kuhn, D M; Ghannoum, M A

    2003-01-01

    Damp buildings often have a moldy smell or obvious mold growth; some molds are human pathogens. This has caused concern regarding health effects of moldy indoor environments and has resulted in many studies of moisture- and mold-damaged buildings. Recently, there have been reports of severe illness as a result of indoor mold exposure, particularly due to Stachybotrys chartarum. While many authors describe a direct relationship between fungal contamination and illness, close examination of the literature reveals a confusing picture. Here, we review the evidence regarding indoor mold exposure and mycotoxicosis, with an emphasis on S. chartarum. We also examine possible end-organ effects, including pulmonary, immunologic, neurologic, and oncologic disorders. We discuss the Cleveland infant idiopathic pulmonary hemorrhage reports in detail, since they provided important impetus for concerns about Stachybotrys. Some valid concerns exist regarding the relationship between indoor mold exposure and human disease. Review of the literature reveals certain fungus-disease associations in humans, including ergotism (Claviceps species), alimentary toxic aleukia (Fusarium), and liver disease (Aspergillys). While many papers suggest a similar relationship between Stachybotrys and human disease, the studies nearly uniformly suffer from significant methodological flaws, making their findings inconclusive. As a result, we have not found well-substantiated supportive evidence of serious illness due to Stachybotrys exposure in the contemporary environment. To address issues of indoor mold-related illness, there is an urgent need for studies using objective markers of illness, relevant animal models, proper epidemiologic techniques, and examination of confounding factors.

  6. [Biological monitoring in the molding of plastics and rubbers].

    Science.gov (United States)

    Fustinoni, S; Campo, L; Cirla, A M; Cirla, P E; Cutugno, V; Lionetti, C; Martinotti, I; Mossini, E; Foà, V

    2007-01-01

    This survey was carried out in the molding of plastics and rubbers, in the "Professional Cancer Prevention Project" sponsored by the Lombardy region with the objective of developing and implementing protocols for evaluating exposure to carcinogens through the biological monitoring. The realities of molding the thermoplastic polymer ABS, rubber, and thermosetting plastics containing formaldehyde were examined. The carcinogenic substances identified in these processes were: 1,3-butadiene, acrylonitrile and styrene in molding ABS, polycyclic aromatic hydrocarbons (PAH) in molding rubber, and formaldehyde in molding the thermosetting plastics. Only for some of these substances biological indicators are available. The limited exposure to airborne chemicals in molding ABS and the intrinsic characteristics of biological indicators available for 1-3 butadiene have determined the non applicability of biological monitoring to this situation. The absence of a biological indicator of exposure to formaldehyde has made this situation not investigable. Exposure in the rubber molding was studied in 19 subjects applying the determination not metabolized PAH in urine. The levels of these indicators were similar to those measured in other groups of subjects without occupational exposure to PAH, confirming a low airborne contamination in this workplace.

  7. Thermomechanical Behavior in Continuous Bloom Casting with Different Mold Tapers

    Institute of Scientific and Technical Information of China (English)

    LUO Xin; CHEN Yong; SHEN Houfa

    2008-01-01

    A two-dimensional finite element model was used to analyze the thermal and mechanical behavior dunng solidification of the strand in a continuous bloom casting mold.The coupled heat transfer and defermation were analyzed to simulate the formation of the air gap between the mold and the strand.The model was used to investigate the influence of mold taper on the temperature and stress distributions in the strand.The results show that the air gap mainly forms around the strand corner,causing a hoRer and thinner solidifying shell in this region.The mold taper partially compensates for the strand shell shnnkage and reduces the infiuence of the air gap on the heat transfer.The mold taper compresses the shell and changes the stress state around the stmnd comer region.As the strand moves down into the mold,the mold constraint causes compressive stress beneath the comer surface.which reduces the hot tear that forms on the strand.

  8. A New Type Machine of Mixing-molding for Polyblends

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan-sheng; LI Li; BIAN Hui-guang

    2009-01-01

    This paper introduces a new type machine for polyblends with excellent mixing capabilities of internal mixer and continuous molding character of extruder. The machine includes two functions -- mixing and extrusion molding that have been composed together by rational design, so a tandem production mode -- "batch + continuous" are opened up. The mathematical model of continuous mixing molding was established and verified availably by experimental research. The main physical mechanical property of vuicanizate, which had met national waterproof material standard, verified the machine practicability. The essential difference from other similar type machines is that this machine is not only suitable in producing granular and powder rubbers but also lumpish tablets.

  9. Development of Integrated Simulation System for Plastic Injection Molding

    Institute of Scientific and Technical Information of China (English)

    CHENGXue-wen; LIDe-qun; ZHOUHua-min

    2005-01-01

    Numerical simulation of injection molding have had success in predicting the behavior of polymer melt in extremely complicated geometries. Most of the current numerical solutions are based on finite-element/finite-difference/boundary-element/volume-control methods and the surface model. This paper discusses the development of an integrated CAE system for injection molding in detail, and presents the mathematics for numerical simulation of filling, packing,cooling, stress and warpage in injection molding. The developed system named as HsCAE3D is introduced at the end.

  10. The analysis of injection molding defects caused by gate vestiges

    Directory of Open Access Journals (Sweden)

    T. Tabi

    2015-04-01

    Full Text Available Issues of product safety are the most serious problems of an injection molded product due to their risk to human health. Such a safety problem can be the needle-shaped vestige at the gate zone of injection molded products, called a gate vestige. Only observations of the formation of gate vestiges can be found in the literature, but the processing parameters influencing their dimensions, especially their height have not been studied yet. Our goal was to study the effect of various injection molding processing parameters and gate constructions on gate vestige formation.

  11. Recent Developments and Trends in Powder Injection Molding

    Institute of Scientific and Technical Information of China (English)

    Hermina Wang

    2000-01-01

    Injection molding is a productive and widely used technology for shaping plastics. The use of this shaping technique to metal and ceramics powders is termed powder injection molding (PIM). This process combines a certain quantity of a polymer with a metallic or ceramic powder to form a feedstock that can be molded. After shaping, the polymeric binder is extracted and the powder is sintered. When proper powder size or/and its distribution are used, sintered densities of 95% or more, often to near-theoretical densities, are reached and the mechanical properties are, therefore, generally superior to those of traditional PM parts.

  12. Fabrication of micro gear wheels by micropowder injection molding

    Institute of Scientific and Technical Information of China (English)

    Haiqing Yin; Xuanhui Qu; Chengchang Jia

    2008-01-01

    The micropowder injection molding technology was investigated to fabricate the microsized gear wheels on a conventional injection molding machine. The feedstock comprised of carbonyl ferrum powder and a wax-based thermoplastic binder. Microinjection molding was fulfilled at about 423 K under 100 MPa. The heating system was applied to the die to improve the fluidity of the feedstock and subsequently the cooling system was used to enhance the strength of the green compacts after injection by decreasing the temperature of the die. The gear wheels were realized successfully with their addendum circle diameter ranging from 800 to 200 m and with the center hole as small as 60 μtm.

  13. Two component micro injection molding for MID fabrication

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2009-01-01

    Molded Interconnect Devices (MIDs) are plastic substrates with electrical infrastructure. The fabrication of MIDs is usually based on injection molding and different process chains may be identified from this starting point. The use of MIDs has been driven primarily by the automotive sector......, but recently the medical sector seems more and more interested. In particular the possibility of miniaturization of 3D components with electrical infrastructure is attractive. The paper describes possible manufacturing routes and challenges of miniaturized MIDs based on two component micro injection molding...

  14. Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding.

    Science.gov (United States)

    Chung, Philip; Heller, J Alex; Etemadi, Mozziyar; Ottoson, Paige E; Liu, Jonathan A; Rand, Larry; Roy, Shuvo

    2014-06-27

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications.

  15. The use of birefringence for predicting the stiffness of injection molded polycarbonate discs

    NARCIS (Netherlands)

    Neves, N.M.; Pouzada, A.S.; Voerman, J.H.D.; Powell, P.C.

    1998-01-01

    Polycarbonate discs were injection molded with different sets of molding conditions. The parameters studied were the flow rate, melt- and mold-temperature. The discs were subjected to three point support flexural tests. Those tests are specially intended for injection molded discs because of their i

  16. 40 CFR 63.5728 - What standards must I meet for closed molding resin operations?

    Science.gov (United States)

    2010-07-01

    ... molding resin operations? 63.5728 Section 63.5728 Protection of Environment ENVIRONMENTAL PROTECTION... Standards for Closed Molding Resin Operations § 63.5728 What standards must I meet for closed molding resin operations? (a) If a resin application operation meets the definition of closed molding specified in §...

  17. Mold Simulator Study on the Initial Solidification of Molten Steel Near the Corner of Continuous Casting Mold

    Science.gov (United States)

    Lyu, Peisheng; Wang, Wanlin; Zhang, Haihui

    2016-11-01

    Corner cracks are one of the most widespread surface defects of continuous casting slabs, and they are especially severe for peritectic steels and low-alloy steels. Therefore, a clear understanding of molten steel initial solidification around mold corner would be of great importance for the inhibition of corner cracks. This paper has been conducted with the aim to elucidate this understanding, by using a novel mold simulator equipped with a right-angle copper mold. The responding temperatures and heat fluxes across the mold hot-face and corner were firstly calculated through a 2D-inverse heat conduction program mathematical model, and the results suggested that the cooling ability and the fluctuation of heat fluxes around the mold corner are stronger than those for mold hot-face. With the help of power spectral density analysis and fast Fourier transformation, the four characteristic signals of heat fluxes were discussed in this paper. Next, the relation between the thickness of solidified shell and solidification time was fitted with the solidification square root law; as a result, the average solidification factor bar{K} for the hot-face shell is 2.32 mm/s1/2, and it is 2.77 mm/s1/2 for the shell near-corner. For the same oscillation marks (OMs), it appeared that the OMs positions on the shell corner are lower than those on the shell hot-face along the casting direction, because the stronger shrinkage of shell at the corner allows the overflowing steel to penetrate deeper into the larger gap between the shell corner and mold, which is demonstrated through the heat transfer analysis and metallographic examination. Finally, the interrelation between shell profile, mold oscillation, variation rate of heat flux, high-frequency heat flux and high-frequency temperature was discussed for above two cases, and the results suggested that meniscus conditions (heat transfer and melt flow) around the mold corner are more unsteady.

  18. Mold Simulator Study on the Initial Solidification of Molten Steel Near the Corner of Continuous Casting Mold

    Science.gov (United States)

    Lyu, Peisheng; Wang, Wanlin; Zhang, Haihui

    2017-02-01

    Corner cracks are one of the most widespread surface defects of continuous casting slabs, and they are especially severe for peritectic steels and low-alloy steels. Therefore, a clear understanding of molten steel initial solidification around mold corner would be of great importance for the inhibition of corner cracks. This paper has been conducted with the aim to elucidate this understanding, by using a novel mold simulator equipped with a right-angle copper mold. The responding temperatures and heat fluxes across the mold hot-face and corner were firstly calculated through a 2D-inverse heat conduction program mathematical model, and the results suggested that the cooling ability and the fluctuation of heat fluxes around the mold corner are stronger than those for mold hot-face. With the help of power spectral density analysis and fast Fourier transformation, the four characteristic signals of heat fluxes were discussed in this paper. Next, the relation between the thickness of solidified shell and solidification time was fitted with the solidification square root law; as a result, the average solidification factor bar{K} for the hot-face shell is 2.32 mm/s1/2, and it is 2.77 mm/s1/2 for the shell near-corner. For the same oscillation marks (OMs), it appeared that the OMs positions on the shell corner are lower than those on the shell hot-face along the casting direction, because the stronger shrinkage of shell at the corner allows the overflowing steel to penetrate deeper into the larger gap between the shell corner and mold, which is demonstrated through the heat transfer analysis and metallographic examination. Finally, the interrelation between shell profile, mold oscillation, variation rate of heat flux, high-frequency heat flux and high-frequency temperature was discussed for above two cases, and the results suggested that meniscus conditions (heat transfer and melt flow) around the mold corner are more unsteady.

  19. INVESTIGATION OF THE INFLUENCE OF MOLD ROTATIONAL SPEED ON THE CAST WALL THICKNESS IN THE ROTATIONAL MOLDING PROCESS

    Directory of Open Access Journals (Sweden)

    Tomasz Jachowicz

    2013-09-01

    Full Text Available This paper presents the rotational molding process. The general principles of this polymer processing technology have been described. The main applications have been introduced and leading advantages and typical disadvantages of rotational molding process have been discussed. Based on the conducted experimental tests, the influence of changing one selected technological parameter, which characterized rotational molding process, on selected geometrical features of the polymer cast has been determined. Rotational mold’s speed around axes was changed and a thickness of cast walls has been measured. Laboratory test stand, processing properties of polymer, also test program and experimental test methodology have been described.

  20. Governança em estruturas proprietárias concentradas: novas evidências para o Brasil

    Directory of Open Access Journals (Sweden)

    Igor Bernardi Sonza

    2014-06-01

    Full Text Available Neste artigo, o objetivo é analisar a influência da estrutura de propriedade na eficiência das empresas de capital aberto brasileiras, em que é identificada maior concentração de ações nas mãos de um grupo restrito de pessoas. No estudo, unem-se técnicas de otimização estática por meio de análise envoltória de dados, para identificar a eficiência das empresas de capital aberto, com dados em painel, para identificar a influência da estrutura de propriedade na eficiência das empresas, buscando agregar governança corporativa à literatura de eficiência produtiva no contexto de diferenças institucionais no ambiente brasileiro, a fim de complementar os estudos prévios que consideram somente os outputs como medidas de eficiência. Nos resultados obtidos, mostra-se que a estrutura de propriedade influencia negativamente a eficiência, contrariando grande parte dos estudos baseados no modelo norte-americano e evidenciando que as peculiaridades dos países devem ser levadas em consideração, principalmente com relação à sua origem legal.

  1. Cavity air flow behavior during filling in microinjection molding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2011-01-01

    Process monitoring of microinjection molding (μ-IM) is of crucial importance in understanding the effects of different parameter settings on the process, especially on its performance and consistency with regard to parts' quality. Quality factors related to mold cavity air evacuation can provide...... valuable information about the process dynamics and also about the filling of a cavity by a polymer melt. In this paper, a novel experimental setup is proposed to monitor maximum air flow and air flow work as an integral of the air flow over time by employing a microelectromechanical system gas sensor...... mounted inside the mold. The influence of four μIM parameters, melt temperature, mold temperature, injection speed, and resistance to air evacuation, on two air flow-related output parameters is investigated by carrying out a design of experiment study. The results provide empirical evidences about...

  2. Smart plastic functionalization by nanoimprint and injection molding

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Thamdrup, Lasse Højlund; Smistrup, Kristian;

    2015-01-01

    In this paper, we present a route for making smart functionalized plastic parts by injection molding with sub-micrometer surface structures. The method is based on combining planar processes well known and established within silicon micro and sub-micro fabrication with proven high resolution...... the pattern. With this approach, we demonstrate the transfer of down to 140 nm wide holes on large areas with good structure fidelity on an injection molding steel insert. The durability of the sub-micrometer structures on the inserts have been investigated by running two production series of 102,000 and 73......,000 injection molded parts, respectively, on two different inserts and inspecting the inserts before and after the production series and the molded parts during the production series....

  3. Cork is used to make tooling patterns and molds

    Science.gov (United States)

    Hoffman, F. J.

    1965-01-01

    Sheet and waste cork are cemented together to provide a tooling pattern or mold. The cork form withstands moderately high temperatures under vacuum or pressure with minimum expansion, shrinkage, or distortion.

  4. Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Josh A. Salmond

    2009-08-07

    The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

  5. Moldability Evaluation for Molded Parts Based on Fuzzy Reasoning

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Moldability evaluation for molded parts, which is the basis of concurrent design, is a key design stage in injection molding design. By moldability evaluation the design problems can be found timely and an optimum plastic part design achieved. In this paper, a systematic methodology for moldability evaluation based on fuzzy logic is proposed. Firstly, fuzzy set modeling for six key design attributes of molded parts is carried out respectively. Secondly, on the basis of this, the relationship between fuzzy sets for design attributes and fuzzy sets for moldability is established by fuzzy rules that are based on domain experts' experience and knowledge. At last the integral moldability for molded parts is obtained through fuzzy reasoning. The neural network based fuzzy reasoning approach presented in this paper can improve fuzzy reasoning efficiency greatly, especially for system having a large number of rules and complicated membership functions. An example for moldability evaluation is given to show the feasibility of this proposed methodology.

  6. Residual stresses in injection molded shape memory polymer parts

    Science.gov (United States)

    Katmer, Sukran; Esen, Huseyin; Karatas, Cetin

    2016-03-01

    Shape memory polymers (SMPs) are materials which have shape memory effect (SME). SME is a property which has the ability to change shape when induced by a stimulator such as temperature, moisture, pH, electric current, magnetic field, light, etc. A process, known as programming, is applied to SMP parts in order to alter them from their permanent shape to their temporary shape. In this study we investigated effects of injection molding and programming processes on residual stresses in molded thermoplastic polyurethane shape memory polymer, experimentally. The residual stresses were measured by layer removal method. The study shows that injection molding and programming process conditions have significantly influence on residual stresses in molded shape memory polyurethane parts.

  7. A corneal mold to restore normal corneal dimensions.

    Science.gov (United States)

    Swinger, C A; Kornmehl, E W; York, S; Forman, J S

    1986-01-01

    A corneal mold is described that provides an MK corneal button of normal thickness and curvature from an edematous, post-mortem button. The uniform, processed tissue can then be used for experimental refractive surgery.

  8. Modular injection mold manufacturing in a selective laser sintering machine

    Science.gov (United States)

    Ikonen, Ilkka T.; Biles, William E.

    1997-12-01

    Reduced time to market places exacting requirements for the speed and quality of the design, manufacture and testing of new plastic parts. Traditionally, the greatest time for getting a new plastic product prototyped and tested is that for the mold fabrication phase. New metal materials for selective laser sintering (SLS) rapid prototyping technology allow direct mold fabrication for prototype plastic parts. Typically these molds are also useable for small scale production runs up to 50,000 parts. Using this technology prototype parts can be manufactured using the same materials and processes as used for the final product allowing testing of the whole manufacturing process for the prototype. This gives a company new opportunities to get a new or modified product to market faster and cheaper than by using traditional mold making processes. In this paper we describe this new technology and discuss how small and mid-size manufacturing companies can benefit from it.

  9. Method and mold for casting thin metal objects

    Energy Technology Data Exchange (ETDEWEB)

    Pehrson, Brandon P; Moore, Alan F

    2014-04-29

    Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

  10. Material flow data for numerical simulation of powder injection molding

    Science.gov (United States)

    Duretek, I.; Holzer, C.

    2017-01-01

    The powder injection molding (PIM) process is a cost efficient and important net-shape manufacturing process that is not completely understood. For the application of simulation programs for the powder injection molding process, apart from suitable physical models, exact material data and in particular knowledge of the flow behavior are essential in order to get precise numerical results. The flow processes of highly filled polymers are complex. Occurring effects are very hard to separate, like shear flow with yield stress, wall slip, elastic effects, etc. Furthermore, the occurrence of phase separation due to the multi-phase composition of compounds is quite probable. In this work, the flow behavior of a 316L stainless steel feedstock for powder injection molding was investigated. Additionally, the influence of pre-shearing on the flow behavior of PIM-feedstocks under practical conditions was examined and evaluated by a special PIM injection molding machine rheometer. In order to have a better understanding of key factors of PIM during the injection step, 3D non-isothermal numerical simulations were conducted with a commercial injection molding simulation software using experimental feedstock properties. The simulation results were compared with the experimental results. The mold filling studies amply illustrate the effect of mold temperature on the filling behavior during the mold filling stage. Moreover, the rheological measurements showed that at low shear rates no zero shear viscosity was observed, but instead the viscosity further increased strongly. This flow behavior could be described with the Cross-WLF approach with Herschel-Bulkley extension very well.

  11. Bioprospection of yeasts as biocontrol agents against phytopathogenic molds

    Directory of Open Access Journals (Sweden)

    Márcia Maria Rosa-Magri

    2011-02-01

    Full Text Available Yeasts isolated from sugar cane and maize rhizosphere, leaves and stalks were screened against the phytopathogenic molds Colletotrichum sublineolum and Colletotrichum graminicola, both causal agents of the anthracnose disease in sorghum and maize, respectively. Strains identified as Torulaspora globosa and Candida intermedia were able to inhibit the mold growth, with the first species also exhibiting killer activity. No previous report on the application and potentiality of these yeasts as biocontrol agents were found neither the killer phenotype in Torulaspora globosa.

  12. Bioprospection of yeasts as biocontrol agents against phytopathogenic molds

    OpenAIRE

    Márcia Maria Rosa-Magri; Sâmia Maria Tauk-Tornisielo; Sandra Regina Ceccato-Antonini

    2011-01-01

    Yeasts isolated from sugar cane and maize rhizosphere, leaves and stalks were screened against the phytopathogenic molds Colletotrichum sublineolum and Colletotrichum graminicola, both causal agents of the anthracnose disease in sorghum and maize, respectively. Strains identified as Torulaspora globosa and Candida intermedia were able to inhibit the mold growth, with the first species also exhibiting killer activity. No previous report on the application and potentiality of these yeasts as bi...

  13. CAE for Injection Molding — Past, Present and the Future

    Science.gov (United States)

    Wang, Kuo K.

    2004-06-01

    It is well known that injection molding is the most effective process for mass-producing discrete plastic parts of complex shape to the highest precision at the lowest cost. However, due to the complex property of polymeric materials undergoing a transient non-isothermal process, it is equally well recognized that the quality of final products is often difficult to be assured. This is particularly true when a new mold or material is encountered. As a result, injection molding has often been viewed as an art than a science. During the past few decades, numerical simulation of injection molding process based on analytic models has become feasible for practical use as computers became faster and cheaper continually. A research effort was initiated at the Cornell Injection Molding Program (CIMP) in 1974 under a grant from the National Science Foundation. Over a quarter of the century, CIMP has established some scientific bases ranging from materials characterization, flow analysis, to prediction of part quality. Use of such CAE tools has become common place today in industry. Present effort has been primarily aimed at refinements of many aspects of the process. Computational efficiency and user-interface have been main thrusts by commercial software developers. Extension to 3-dimensional flow analysis for certain parts has drawn some attention. Research activities are continuing on molding of fiber-filled materials and reactive polymers. Expanded molding processes such as gas-assisted, co-injection, micro-molding and many others are continually being investigated. In the future, improvements in simulation accuracy and efficiency will continue. This will include in-depth studies on materials characterization. Intelligent on-line process control may draw more attention in order to achieve higher degree of automation. As Internet technology continues to evolve, Web-based CAE tools for design, production, remote process monitoring and control can come to path. The CAE

  14. Evaluation of Additive Manufacturing for Composite Part Molds

    Energy Technology Data Exchange (ETDEWEB)

    Duty, Chad E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Springfield, Robert M. [Tru Design, LLC, Knoxville, TN (United States)

    2015-02-01

    The ORNL Manufacturing Demonstration Facility (MDF) collaborated with Tru-Design to test the quality and durability of molds used for making fiber reinforced composites using additive manufacturing. The partners developed surface treatment techniques including epoxy coatings and machining to improve the quality of the surface finish. Test samples made using the printed and surface finished molds demonstrated life spans suitable for one-of-a-kind and low-volume applications, meeting the project objective.

  15. The Simulation and Optimization of Aspheric Plastic Lens Injection Molding

    Institute of Scientific and Technical Information of China (English)

    WEN Jialing; WEN Pengfei

    2005-01-01

    For the purpose of reducing the volumetric shrinkage and volumetric shrinkage variation, the process in injection molding of aspheric plastic lens was simulated, and several process parameters which include holding pressure, melt temperature, mold temperature, fill time, holding pressure time and cooling time were optimized by using an orthogonal experimental design method. Finally, the optimum process parameters and the influence degree of process parameters on the average volumetric shrinkage and the volumetric shrinkage variation are obtained.

  16. Localized rapid heating process for precision chalcogenide glass molding

    Science.gov (United States)

    Li, Hui; He, Peng; Yu, Jianfeng; Lee, L. James; Yi, Allen Y.

    2015-10-01

    Precision glass molding is an important process for high volume optical fabrication. However, conventional glass molding is a bulk heating process that usually requires a long thermal cycle, where molding assembly and other mechanical parts are heated and cooled together. This often causes low efficiency and other heating and cooling related problems, such as large thermal expansion in both the molds and molded optics. To cope with this issue, we developed a localized rapid heating process to effectively heat only very small part of the glass. This localized rapid heating study utilized a fused silica wafer coated with a thin graphene layer to heat only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating heat on and near the coating. The feasibility of this process was validated by both experiments and numerical simulation. To demonstrate the advantages of the localized rapid heating, both localized rapid heating process and bulk heating process were performed and carefully compared. The uniformity and quality of the molded sample by localized rapid heating process was also demonstrated. In summary, localized rapid heating process by using graphene coated fused silica wafer was characterized and can be readily implemented in replication of micro scale chalcogenide glasses. A fused silica wafer coated with a thin graphene layer was utilized for localized rapid heating only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating high temperature on and near the coating. This process is fast and efficient since only interested areas are heated without affecting the entire glass substrate or the mold assembly. The uniformity and quality of the molded sample by localized rapid heating process was demonstrated by comparing both localized rapid heating

  17. Classification of buildings mold threat using electronic nose

    Science.gov (United States)

    Łagód, Grzegorz; Suchorab, Zbigniew; Guz, Łukasz; Sobczuk, Henryk

    2017-07-01

    Mold is considered to be one of the most important features of Sick Building Syndrome and is an important problem in current building industry. In many cases it is caused by the rising moisture of building envelopes surface and exaggerated humidity of indoor air. Concerning historical buildings it is mostly caused by outdated raising techniques among that is absence of horizontal isolation against moisture and hygroscopic materials applied for construction. Recent buildings also suffer problem of mold risk which is caused in many cases by hermetization leading to improper performance of gravitational ventilation systems that make suitable conditions for mold development. Basing on our research there is proposed a method of buildings mold threat classification using electronic nose, based on a gas sensors array which consists of MOS sensors (metal oxide semiconductor). Used device is frequently applied for air quality assessment in environmental engineering branches. Presented results show the interpretation of e-nose readouts of indoor air sampled in rooms threatened with mold development in comparison with clean reference rooms and synthetic air. Obtained multivariate data were processed, visualized and classified using a PCA (Principal Component Analysis) and ANN (Artificial Neural Network) methods. Described investigation confirmed that electronic nose - gas sensors array supported with data processing enables to classify air samples taken from different rooms affected with mold.

  18. Frequency of Mold Allergens in Allergic Rhinitis Patients

    Directory of Open Access Journals (Sweden)

    Bonyadi, MR. (PhD

    2014-06-01

    Full Text Available Background and Objective: Allergic rhinitis can be stimulated by several allergens. Molds are among these allergens and it is important to assess their frequency in different geographic area. Hence, we aimed at determining the frequency of mold allergens in allergic rhinitis patients referred to specialized clinics of Tabriz Imam Reza hospital, 2011. Material and Methods: This cross-sectional study was conducted on the serums of 90 rhinitis patients diagnosed by specialized physician. Using Immunoblotting method, the level of specific IgE against four molds including Penicillium, Aspergillus, Alternaria and Cladosporium were investigated. Results: Of 90 Patients, 40 were men (44.4% and 50 were women (55.6%. The participants were between 6 to 53 years and the most were 28-31years. The allergy was related to Penicillium (3.3%, Aspergillus (5.6%, Alternaria (13.3% and Cladosporium (4.4%. There was a significant statistical relation between age and allergic rhinitis to Alternaria (P=0.011. Conclusion: Molds can grow and proliferate in very humid environments. Because of low humidity climate in Tabriz (in the northwest of Iran, allergy to molds is relatively low in this region. Key words: Rhinitis Allergic; Mold; Allergy

  19. Prediction of Mold Spoilage for Soy/Polyethylene Composite Fibers

    Directory of Open Access Journals (Sweden)

    Chinmay Naphade

    2015-01-01

    Full Text Available Mold spoilage was determined over 109 days on soy/PE fibers held under controlled temperatures (T ranging from 10°C to 40°C and water activities (aw from 0.11 to 0.98. Water activities were created in sealed containers using saturated salt solutions and placed in temperature-controlled incubators. Soy/PE fibers that were held at 0.823 aw or higher exhibited mold growth at all temperatures. As postulated, increased water activity (greater than 0.89 and temperature (higher than 25°C accelerated mold growth on soy/PE fibers. A slower mold growth was observed on soy/PE fibers that were held at 0.87 aw and 10°C. A Weibull model was employed to fit the observed logarithmic values of T, aw, and an interaction term log⁡T×log⁡aw and was chosen as the final model as it gave the best fit to the raw mold growth data. These growth models predict the expected mold-free storage period of soy/PE fibers when exposed to various environmental temperatures and humidities.

  20. Precision glass molding of high-resolution diffractive optical elements

    Science.gov (United States)

    Prater, Karin; Dukwen, Julia; Scharf, Toralf; Herzig, Hans P.; Plöger, Sven; Hermerschmidt, Andreas

    2016-04-01

    The demand of high resolution diffractive optical elements (DOE) is growing. Smaller critical dimensions allow higher deflection angles and can fulfill more demanding requirements, which can only be met by using electron-beam lithography. Replication techniques are more economical, since the high cost of the master can be distributed among a larger number of replicas. The lack of a suitable mold material for precision glass molding has so far prevented an industrial use. Glassy Carbon (GC) offers a high mechanical strength and high thermal strength. No anti-adhesion coatings are required in molding processes. This is clearly an advantage for high resolution, high aspect ratio microstructures, where a coating with a thickness between 10 nm and 200 nm would cause a noticeable rounding of the features. Electron-beam lithography was used to fabricate GC molds with highest precision and feature sizes from 250 nm to 2 μm. The master stamps were used for precision glass molding of a low Tg glass L-BAL42 from OHARA. The profile of the replicated glass is compared to the mold with the help of SEM images. This allows discussion of the max. aspect-ratio and min. feature size. To characterize optical performances, beamsplitting elements are fabricated and their characteristics were investigated, which are in excellent agreement to theory.

  1. Development of mold for biodegradable materials

    Energy Technology Data Exchange (ETDEWEB)

    Japitana, F.H.; Jabrica, A.M. [Metals Industry Research and Develeopment Center, Manila (Philippines). Dept. of Science and Technology; Komatsu, M. [Komatsu Consulting Engineer Office, Iwaki City, Fukushima (Japan); Takeuchi, Y. [Osaka Univ., Osaka (Japan). Dept. of Mechanical Engineering

    2008-07-01

    The improper disposal of non-biodegradable plastics adversely affect global environmental factors, principles of sustainability, industrial ecology and ecoefficiency. Therefore, a new generation of bio-based polymeric products has been developed. These polylactides (PLA), cellulose esters, starch plastics and polyhydroxyalkanoates (PHAs) are made from renewable natural resources and are biodegradable. They meet environmental conditions and can compete with their petrochemical counterparts. Among them, PLA is particularly attractive as a sustainable alternative to synthetic polymers and a potential candidate for the fabrication of biocomposites. Certain blends have proved successful in medical implants, sutures and drug delivery systems because of their capacity to dissolve away with time. However, widespread use of PLA is limited because of cost. Biodegradable plastic products are currently 6 to 10 times more expensive than traditional plastics. Environmentalists argue that the cheaper price of traditional plastics does not reflect their true cost when their impact is considered. This paper presented a solution to reduce the production cost of biodegradable plastics. In particular, it described a newly developed plastic injection mold for biodegradable materials which can produce a scrapless product. The system reduces processing time because it is not necessary to remove any gating or runners after the injection process. Takeout robots ensure that the quality of the product is maintained. 12 figs.

  2. Determination of heat transfer coefficients at the polymer-mold-interface for injection molding simulation by means of calorimetry

    Science.gov (United States)

    Stricker, M.; Steinbichler, G.

    2014-05-01

    Appropriate modeling of heat transfer from the polymer material to the injection mold is essential to achieve accurate simulation results. The heat transfer is commonly modeled using convective heat transfer and applying heat transfer coefficients (HTC) to the polymer-mold-interface. The set HTC has an influence on the results for filling pressure, cooling performance and shrinkage, among others. The current paper, presents a new strategy to measure HTC in injection molding experiments using Newtons law of cooling. The heat flux is calculated out of demolding heat (measured by means of calorimetry), injection heat (measured by means of an IR-sensor), cooling time and part mass. Cavity surface area, average mold surface temperature and average part surface temperature lead to the HTC.

  3. Evolution of Surface Texture and Cracks During Injection Molding of Fiber-Reinforced, Additively-Manufactured, Injection Molding Inserts

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Mischkot, Michael; Pedersen, David Bue

    2016-01-01

    This paper investigates the lifetime and surfacedeterioration of additively-manufactured, injection-moulding inserts. The inserts were produced using digital light processing and were reinforcedwith oriented short carbon fibers. Theinserts were used during injection molding oflow-density polyethy......This paper investigates the lifetime and surfacedeterioration of additively-manufactured, injection-moulding inserts. The inserts were produced using digital light processing and were reinforcedwith oriented short carbon fibers. Theinserts were used during injection molding oflow......-density polyethylene until their failure. The molded products were used to analyse the development of the surface roughness and wear. By enhancing the lifetime of injection-molding inserts,this work contributes to the establishment of additively manufactured inserts in pilot production....

  4. Evolution of Surface Texture and Cracks During Injection Molding of Fiber-Reinforced, Additively-Manufactured, Injection Molding Inserts

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Mischkot, Michael; Pedersen, David Bue

    2016-01-01

    This paper investigates the lifetime and surfacedeterioration of additively-manufactured, injection-moulding inserts. The inserts were produced using digital light processing and were reinforcedwith oriented short carbon fibers. Theinserts were used during injection molding oflow-density polyethy...

  5. Investigation of Heat Transfer at the Mold/Metal Interface in Permanent Mold Casting of Light Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Robert D. Pehlke; John T. Berry

    2005-12-16

    Accurate modeling of the metal casting process prior to creating a mold design demands reliable knowledge of the interfacial heat transfer coefficient at the mold metal interface as a function of both time and location. The phenomena concerned with the gap forming between the mold and the solidifying metal are complex but need to be understood before any modeling is attempted. The presence of mold coatings further complicates the situation. A commercial casting was chosen and studied in a gravity permanent mold casting process. The metal/mold interfacial heat transfer coefficient (IHTC) was the focus of the research. A simple, direct method has been used to evaluate the IHTC. Both the simulation and experiments have shown that a reasonably good estimate of the heat transfer coefficient could be made in the case studied. It has been found that there is a good agreement between experiments and simulations in the temperature profiles during the solidification process, given that the primary mechanism of heat transfer across the gap in permanent mold casting of light alloys is by conduction across the gap. The procedure utilized to determine the interfacial heat transfer coefficient can be applied to other casting processes. A recently completed project involving The University of Michigan and Mississippi State University, together with several industrial partners, which was supported by the USDOE through the Cast Metals Coalition, examined a number of cases of thermal contact. In an investigation which gave special consideration to the techniques of measurement, several mold coatings were employed and results presented as a function of time. Realistic conditions of coating thickness and type together with an appropriate combination of mold preheat and metal pouring temperature were strictly maintained throughout the investigation. Temperature sensors, in particular thermocouples, play an important part in validating the predictions of solidification models. Cooling

  6. Percebendo as facilidades e dificuldades na implantação de serviços abertos em álcool e drogas

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Ferreira

    2004-01-01

    Full Text Available Estudios demostran el uso de sustancias psicoactivas desde las civilizaciones más antiguas. Los psicóticos actúan en el cerebro alterando el comportamiento y causando graves problemas de salud. Solamente a partir de 1990 fueron organizados los primeros servicios abiertos en alcohol y drogas. La finalidad de este estudio fue describir las facilidades y dificultades observadas por los centros durante el proceso de implantación. Es una investigación cualitativa, basada en estudio de caso, con entrevistas semi-estructuradas y sujetos previamente escogidos, utilizándose la muestra con criterios. Los entrevistados indicaron como dificultades el espacio físico inadecuado, poco investimiento gubernamental, falta de profesionales especializados y recursos financieros. Con respecto a las facilidades, discribiron la motivación de los profesionales para hacer ese trabajo y para especializarse, el interés de las universidades en investigar esa línea, y de la sociedad en nuevas alternativas para el tratamiento. El trabajo será relevante como base para la implantación de nuevos servicios abiertos en alcohol y drogas.

  7. Avaliação de três áreas de solo construído após mineração de carvão a céu aberto em Lauro Müller, Santa Catarina

    Directory of Open Access Journals (Sweden)

    Campos M. L.

    2003-01-01

    Full Text Available Em solos construídos após mineração de carvão, a contaminação das camadas superficiais com pirita provoca intensa acidificação do solo, acelera a intemperização de minerais, eleva os teores de Al e Mn e aumenta a lixiviação de bases. O presente trabalho avaliou características químicas, teor de argila e mineralogia, bem como a variabilidade espacial para algumas dessas características em três áreas de solos construídos após mineração de carvão a céu aberto no município de Lauro Müller, Santa Catarina. As três áreas selecionadas apresentavam diferenças no modo de construção topográfico. A primeira, denominada Mina Juliana (MJ, foi construída em 1996, utilizando material (sólum, regolito argiloso e rocha que foi separado e estocado antes da mineração, conforme previsto no plano de reabilitação. A segunda, denominada Mina do Apertado (MA, foi construída, em 1996, usando, como material de cobertura, o sólum proveniente do decapeamento de um morro adjacente à área. A terceira área, denominada Mina Rio do Meio (MRM, sofreu apenas construção topográfica em 1983, com mistura de resíduos de pirita de carvão e rochas de várias camadas. Amostras de solo foram coletadas em sistema de grade de pontos, em três profundidades, sendo analisados o pH em água, teores de Ca, Mg, K e Al trocáveis, H + Al e condutividade elétrica. Em amostras selecionadas, analisaram-se alguns metais pesados e a mineralogia da fração argila. Análises efetuadas em dois perfis de solo representativos das condições anteriores à mineração foram utilizados, para comparação. Todas as áreas apresentaram grande dispersão de valores para características químicas e teor de argila dos solos entre os pontos amostrados. O processo de construção do solo que resultou em maior uniformidade destas características e melhores condições para o estabelecimento de espécies vegetais foi o da área MJ. O solo da área MA, graças

  8. Characteristics and infl uence factors of mold fi lling process in permanent mold with a slot gating system

    Directory of Open Access Journals (Sweden)

    Chen Changjun

    2009-11-01

    Full Text Available The main problems caused by improper gating are entrained aluminum oxide fi lms and entrapped gas. In this study, the slot gating system is employed to improve mold fi lling behavior and therefore, to improve the quality of aluminum castings produced in permanent molds. An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum fl owing into permanent molds have been developed. Graphite molds transparent to X-rays are utilized which make it possible to observe the fl ow pattern through a number of vertically oriented gating systems. The investigation discovers that there are many infl uencing factors on the mold fi lling process. This paper focuses its research on some of the factors, such as the dimensions of the vertical riser and slot thickness, as well as roughness of the coating layer. The results indicate that molten metal can smoothly fi ll into casting cavity with a proper slot gating system. A bigger vertical riser, proper slot thickness and rougher coating can provide not only a better mold fi lling pattern, but also hot melt into the top of the cavity. A proper temperature gradient is obtainable, higher at the bottom and lower at the top of the casting cavity, which is in favor of feeding during casting solidifi cation.

  9. Foaming morphology control of microcellular injection molded parts with gas counter pressure and dynamic mold temperature control

    Science.gov (United States)

    Shiu, Tai-Yi; Huang, Chao-Tsai; Chang, Rong-Yu; Hwang, Shyh-Shin

    2014-05-01

    Microcellular injection molding process is a promising solution for products with special requirements such as weight reduction, extra thin wall, high dimensional stability, clamping force reduction, etc. Despite microcellular foaming application used in reciprocating screw injection molding machine was built more than a decade, some limitations, such as poor surface quality or poor foaming control, confine the usage of this technology. Earlier CAE simulation tool for microcellular injection molding was not successful due to insufficient physical and computational considerations, limited by complicated bubble growth mechanism; so that, an economic and efficient tool for examining foaming quality of injection foaming product was lack. In this study, a recent developed three-dimensional simulation tool is used to predict injection foaming process. Predictions are carried out with commodity polypropylene and polystyrene with nitrogen and carbon dioxide supercritical fluids (SCFs). Comparisons of simulations between microcellular injection molding with and without counter pressure are discussed to provide insights into the correlation of surface quality and cell size distribution near the surface of product. Furthermore, comparisons between simulation predictions and experimental results of molding process, which is featured with dynamic mold temperature and gas counter pressure, are given for understanding quality improvement by controlling foaming morphology, and benefit of industrial application.

  10. Effect of cross sectional geometry on PDMS micro peristaltic pump performance: comparison of SU-8 replica molding vs. micro injection molding.

    Science.gov (United States)

    Graf, Neil J; Bowser, Michael T

    2013-10-07

    Two different fabrication methods were employed to fabricate micropumps with different cross-sectional channel geometries. The first was to fabricate rectangular cross-sectional microchannel geometries using the well known fabrication method of replica molding (REM). The second, and far less utilized fabrication technique, was to create microchannel molds using an in-house fabricated handheld micro injection molding apparatus. The injection mold apparatus was designed for use with elastomeric room temperature vulcanization (RTV) polymers, as opposed to most other injection molding machines, which are designed for use with thermoplastic polymers. The injection mold's bottom plate was used as a microchannel molding template. The molding template was created by threading a small-diameter wire (150 μm or less) through the injection mold's bottom plate, with subsequent adhesion and smoothing of a thin piece of aluminum foil over the wire-raised injection mold template. When molded against, the template produced a rounded/Gaussian-shaped PDMS microchannel. The design of the injection mold will be presented, along with a direct comparison for micropump performance metrics such as flow rate, valving characteristics, and maximum backpressures attainable for each of the respective micropump channel geometries.

  11. Analysis of Injection Molding Process Based on MoldFlow/MPI for Large Plastic Pallet%基于MoldFlow/MPI的大型塑料托盘注射成型分析

    Institute of Scientific and Technical Information of China (English)

    段贤勇

    2012-01-01

    运用MoldFlow/MPI模块对大型塑料托盘注射成型过程进行模流分析,预测了可能出现的注射短射等缺陷,根据分析结果,提出了工艺优化方案,从而缩短模具设计制造周期。%Used MoldFlow/MPI to analyze the mold flow for the large plastic pallet molding process, and predict the possible injection molding defects such as injection molding short shot. According to the analysis, it gives process optimization to reduce the mold design and manufacture cycle.

  12. The thermal distortion of continuous-casting billet molds

    Science.gov (United States)

    Samarasekera, I. V.; Anderson, D. L.; Brimacombe, J. K.

    1982-03-01

    Preliminary mathematical analyses involving plate bending theory and two-dimensional elastic calculations have revealed that the dominant component contributing to the distortion of continuous-casting billet molds is thermal expansion in the transverse directions. A three-dimensional, elasto-plastic, finite-element analysis of the mold wall has then shown that localized yielding initiates in a region close to the meniscus. The plastic flow is a result of the high thermal stresses induced by the geometric restraint to bending coupled with the locally high temperatures. The resultant distortion profile of the mold down the centerline of a face exhibits a maximum outward bulge of 0.1 to 0.3 mm, which is bounded above by a region of negative taper (1˜2 pct/m) and below by a region of positive taper (˜0.4 pct/m). Measurements of mold wall movement in an operating billet caster using linear displacement transducers compare favorably with model predictions, except in the meniscus region. Case studies of several industrial billet molds have shown that lowering the meniscus level with respect to the location of constraints, or modifying the method of support of the mold tube within its housing so as to reduce the restraint to thermal expansion in the meniscus region, may minimize the extent of permanent distortion. Also, wall thickness can have a significant effect on thermal distortion. Increasing wall thickness results in an increase in both peak wall temperatures and thermal gradients. The former increases the local distortion while the latter causes higher thermal stress levels and possibly permanent distortion. Of the casting variables that can be manipulated to major advantage, cooling water flow rate is the most important. Increasing the water velocity reduces mold wall temperatures, as well as both the total and permanent distortion of the wall.

  13. Orientation of Carbon Fibers in Copper matrix Produced by Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Irfan Shirazi M.

    2014-07-01

    Full Text Available Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.

  14. Diagnosis parameters of mold filling pattern for optimization of a casting system

    Directory of Open Access Journals (Sweden)

    Jun-Ho Hong

    2012-11-01

    Full Text Available For optimal design of a gating system, the setting of diagnosis parameters is very important. In this study, the permanent mold casting process was selected because most of the other casting processes have more complicated factors that influence the mold filling pattern compared to the permanent mold casting process, such as the surface roughness of mold, gas generation from the mold wash and binder of sand mold, and the gas permeability through a sand mold, etc. Two diagnosis parameters (flow rate difference and arrival time difference of molten metal flow pattern in the numerical simulation are suggested for design of an optimum casting system with a permanent mold. The results show that the arrival time difference can be used as one important diagnosis parameter of the complexity of the runner system and its usefulness has been verified via making aluminum parts using permanent mold casting (Fig. 9.

  15. Improvement of machining quality of copper-plated roll mold by controlling temperature variation

    Institute of Scientific and Technical Information of China (English)

    Tae-Jin JE; Eun-Chae JEON; Sang-Cheon PARK; Doo-Sun CHOI; Kyung-Hyun WHANG; Myung-Chang KANG

    2011-01-01

    Micro prism film used in LCD industry can be manufactured by roll to roll method with copper-plated roll mold. As copper-plated roll mold is getting larger, pitch error is getting severer. The pitch error drops the quality of micro prism film. The main cause of the pitch error was investigated during machining large roll mold whose machined length was 1 200 mm. The temperature of machining system was elevated during machining roll mold, and this elevation induced thermal expansion of the system. The temperature variation around the roll mold also made thermal expansion of the roll mold. The amount of thermal expansion had strong relationship to the amount of pitch error. Therefore, the roll mold was machined after warming-up of machining system and precise temperature controller around copper-plated roll mold was installed, which minimized the temperature variation. Finally,precise micro prism patterns without pitch error were machined on the large roll mold.

  16. Residual stress distribution in injection molded parts

    Directory of Open Access Journals (Sweden)

    P. Postawa

    2006-08-01

    Full Text Available Purpose: The paper presents the results of the investigations of influence of the amorphous polystyrene (PSprocessing on the diversity of the internal stresses observed in the injection moulded piece.Design/methodology/approach: For the tests, the standardized mould piece designed for the investigations ofthe processing shrinkage of thermoplastics materials has been used. The samples have been prepared using theDesign of Experiment (DoE theory.The state of internal stresses has been analysed by means of photoelastic method (used stress viewer equipmenton the basis of the layout and size of the isochromatics (fields with the same colour, which determine the mouldpiece’s areas where the same value for the difference of main tensions. In the article the results of investigationsof influence of 5 chosen processing parameters such as injection temperature Tw, mould temperature Tf,clamping pressure pd, cooling time tch and the injection speed vw on the changes in isochromatics layout as adeterminant for diversity of internal stresses in injection moulded pieces have been presented.Findings: The performed investigations of the influence of injection conditions on the state of internal stressesreached for injection mould pieces were to determine the parameters of injection at which the achieved state ofthe stresses in the mould piece (described by the difference of main tensions will show the lowest values.Practical implications: Effects of examinations of influence of processing conditions on residual stress ininjection molded parts (presented in the article could find practical application in polymer industry, both smalland large enterprises.Originality/value: New approach to fast estimation of value of residual stresses were present in the paper.

  17. Avaliação da eficácia do bimatoprosta 0,03% (Glamigan, Germed, Brasil na redução da pressão intraocular em pacientes com glaucoma primário de ângulo aberto e hipertensão ocular

    Directory of Open Access Journals (Sweden)

    Juliana Almodin

    2012-08-01

    Full Text Available OBJETIVO: Avaliar a eficácia do colírio bimatoprosta 0,03% (Glamigan, Germed, Brasil na redução da pressão intraocular (PIO em pacientes com glaucoma primário de ângulo aberto (GPAA ou hipertensão ocular (HO, bem como avaliar os efeitos colaterais decorrentes do uso da droga no desenho epidemiológico randomizado, controlado. MÉTODOS: Foram avaliados pacientes portadores de GPAA ou HO, acima de 18 anos de idade. Todos os pacientes receberam o colírio Glamigan® como primeira droga a ser introduzida no tratamento, tendo sido utilizada uma gota uma vez ao dia (à noite, e 30 dias após foram submetidos à tonometria de aplanação (Goldmann para mensuração da PIO. RESULTADOS: A amostra do estudo foi composta por 35 (66 olhos pacientes portadores de GPAA e HO, sendo 16 do sexo masculino (45,7% e 19, do feminino (54,3%. A média de idade foi de 66,7 anos, sendo a idade máxima 84 anos. A média de redução da PIO após 30 dias de uso do Glamigan® foi de 6,5mmHg. Em relação aos efeitos colaterais, 17 (26,6% pacientes referiram hiperemia conjuntival, 10 (15,6% a dor, 8 (12,5% o ardor, 5 (7,8% o prurido ocular e 2 (3,1% o embaçamento visual. CONCLUSÃO: A medicação Glamigan® foi eficiente na redução da PIO após 30 dias de uso contínuo, na dose de 1x/dia. Acerca dos efeitos colaterais, os mais observados foram hiperemia ocular (26,6% e dor (15,6%, porém estudos com maior tempo de seguimento dos pacientes se fazem necessários a fim de investigar a importância daqueles na terapia com o Glamigan®.

  18. A influência da qualidade na atratividade de instituições de ensino superior com capital aberto La influencia de la calidad en la atracción de instituciones de educación superior con el capital abierto The influence of the quality in the attractiveness of higher education institutions with open market

    Directory of Open Access Journals (Sweden)

    Maria Cristina N. Gramani

    2008-09-01

    Full Text Available Quando a rentabilidade está aliada à qualidade de uma Instituição de Ensino Superior (IES com capital aberto, sua atratividade por parte de futuros investidores é maior. Em geral, a rentabilidade das IES´s é divulgada por meio de prospectos, resultados trimestrais e relação com investidores (RI, entretanto esforços bem menores são alocados às demonstrações de indicadores de qualidade. Desta forma, este artigo propõe identificar fatores que refletem a qualidade de IES´s, apontando doze indicadores, dentre os quais, alguns que levam a benefícios à qualidade e outros que podem acusar riscos de diminuição da qualidade. Também foi construído um mapa de posicionamento com estes doze indicadores alocando-os nas variáveis rentabilidade e qualidade, de forma a identificar o nível de atratividade de uma IES.Cuando la rentabilidad se alía a la calidad de una Institución de Educación Superior (IES, su atracción de parte de inversor es más grande. La rentabilidad de las IES´s se comunica generalmente a través de prospectos, de informes trimestrales y relaciones con los inversores, no obstante son pocos los esfuerzos para presentar los indicadores de la calidad. De tal manera, este artículo considera los factores que reflejan la calidad de IES´s, señalando doce indicadores, entre las cuales, algo que llevan las ventajas la calidad y otros que pueden acusar riesgos con la reducción de la calidad. También fue construido un mapa de la colocación con estos doce indicadores con sus variables renta y calidad, de la forma que identifique el nivel de la atracción de un IES.When the yield is connected to the quality of a Higher Education Institution (HEI, its attractiveness for future investors is larger. In general, the yield data of the HEI's is available in prospects, quarterly results and relations with investors (RI. However, less effort is placed to demonstrations of quality indicators. So, this article intends to identify

  19. Evaluación de moldes cerámicos en procesos de fundición

    Directory of Open Access Journals (Sweden)

    Héctor Mosquera Mosquera

    2011-11-01

    Full Text Available La búsqueda de nuevas líneas de investigación en el campo de los materiales y procesos, (para desarrollar en el futuro nos llevo a realizar un sondeo de evaluación de los materiales cerámicos en la fabricación de moldes para los procesos de fundición, con el objeto de economizar costos de operación en la elaboración de los elementos de maquinas y piezas matrices de formas complejas(intrincadas principalmente. La tundición en cerámica es un proceso de fundición de precisión que emplea para la fabricación de los moldes, materiales cerámicos de grano muy fino aglutinados con sustancias especiales tales como el silicato de etilo. El uso de este aglutinante permite la posibilidad de controlar el tiempo de endurecimiento del mol de; obteniéndose piezas con gran acabado superficial, finos detalles y alto grade de precisión dimensional. 

  20. Teste de provocação oral aberto na confirmação de alergia ao leite de vaca mediada por IgE: qual seu valor na prática clínica? Open oral food challenge in the confirmation of cow's milk allergy mediated by IgE: what is its value in the clinical practice?

    Directory of Open Access Journals (Sweden)

    Raquel Bicudo Mendonça

    2011-09-01

    Full Text Available OBJETIVO: Revisar os principais protocolos de padronização para o teste de provocação oral aberto aplicado a crianças com suspeita de alergia ao leite de vaca mediada por imunoglobulina E. FONTES DE DADOS: Foram selecionados artigos publicados, nos últimos dez anos, nas bases de dados Medline, Lilacs e SciELO, utilizando-se os descritores de assunto: "hipersensibilidade alimentar", "leite de vaca", "alergia ao leite de vaca", "teste de provocação oral", "crianças" e "diagnóstico". SÍNTESE DOS DADOS: O teste de provocação oral é o método mais fidedigno para estabelecer ou excluir o diagnóstico de alergia alimentar e sua forma aberta pode ser a primeira opção, quando apenas reações objetivas são esperadas. O local para realizar o teste deve possuir todos os recursos para tratamento de emergência. Como preparo, o paciente deve seguir dieta de exclusão do alimento suspeito e descontinuar o uso de medicamentos que possam interferir no resultado do teste. Habitualmente, utilizam-se 8 a 10g de leite em pó ou 100mL de leite fluido, oferecidos em volumes progressivos, a intervalos de dez a 60 minutos. Apesar da rigidez do método, ainda existem situações em que há dificuldade de interpretação dos resultados; por isso, médicos bem treinados devem aplicar o teste, sendo cautelosos ao julgarem as reações. CONCLUSÕES: Mesmo considerando as limitações que dificultam a aplicação do teste de provocação oral na prática clínica, a implementação do teste nos serviços de saúde poderia reduzir diagnósticos falsos-positivos de alergias.OBJECTIVE: To review the main standardization protocols of the open oral food challenge applied to children with suspicion of cow's milk allergy mediated by immunoglobulin E. DATA SOURCE: Medline, Lilacs and SciELO databases were searched for articles published in the last ten years using the following descriptors: "food hypersensitivity", "cow's milk", "cow's milk allergy", "oral food

  1. UG Mold Wizard in injection mold design application%UG MoldWizard在注射模具设计中的应用

    Institute of Scientific and Technical Information of China (English)

    陆龙福; 黄常翼

    2013-01-01

    Currently plastics increasingly broad application areas, plastic products has become the automotive, aerospace, electrical and electronics, packaging, building materials, agriculture and other fields indispensable parts and plastic parts are produced almost all through the plastic mold molding to obtain The. As technology advances and high-tech product development and continuous innovation, the technical plastics increasingly high demand, relying on manual mold design and manufacturing engineers is difficult to meet the needs of the development of production. UG mold soft-ware emergence and development, has become a contemporary mold design and manufacture of an important and indis-pensable auxiliary tools.%目前塑料制品的应用领域日益广阔,塑料产品已成为汽车、航空航天、电子电气、包装、建材、农业等领域中不可缺少的部分,而塑料制件的生产几乎都是通过塑料模具的成型来获得的。随着技术进步以及高科技产品的不断开发与创新,对塑料制品的各项技术要求越来越高,仅靠模具工程师手工设计与制造很难满足生产发展的需要。 UG模具软件的出现与发展,已成为当代模具设计与制造中不可缺少的重要辅助工具之一。

  2. Discussion on compact mechanism of air-stream and synchro-formed clamp plate impact molding

    Directory of Open Access Journals (Sweden)

    Zhenling WANG

    2004-11-01

    Full Text Available Applying the air impact molding method to mold the complicated pattern with wider opening surface and deeper concave, there always exist vaulted phenomenon and lower compactibility of sand mold over the entrance and the concave regions. Using the air-stream and synchro-formed clamp plate impact molding, however, this problem will be preferably solved. In this paper, the compact mechanism of the new molding method and the effect of some configuration factors, such as the area flowed by compressed air and the highness of the protruding block displacement around the diffluent clamp plate, on the compactibility of sand mold were discussed.

  3. Development of the computer-aided process planning (CAPP system for polymer injection molds manufacturing

    Directory of Open Access Journals (Sweden)

    J. Tepić

    2011-10-01

    Full Text Available Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-aided design (CAD, computer-aided process planning (CAPP and computer-aided manufacturing (CAM technologies.

  4. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.

    2007-01-01

    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  5. Surface Graphite Degeneration in Ductile Iron Castings for Resin Molds

    Institute of Scientific and Technical Information of China (English)

    Iulian Riposan; Mihai Chisamera; Stelian Stan; Torbjorn Skaland

    2008-01-01

    The objective of this paper is to review the factors influencing the formation of degenerated graph-ite layers on the surfaces of ductile iron castings for chemical rosins-acid molding and coro-making systems and how to reduce this defect. In the rosin mold technique the sulphur in the P-toluol sulphonic acid (PTSA),usually used as the hardener, has been identified as one factor causing graphite degeneration at the metal-mold interface. Less than 0.15% S in the mold (or even less than 0.07% S) can reduce the surface layer depth. Oxygen may also have an effect, especially for sulphur containing systems with turbulent flows in the mold, water-bearing no-bake binder systems, Mg-Silica reactions, or dross formation conditions. Despite the lower level of nitrogen in the iron melt after magnesium treatment (less than 90 ppm), nitrogen bearing res-ins have a profound effect on the frequency and severity of surface pinholes, but a limited influence on sur-face graphite degeneration.

  6. Relevant Aspects in Modeling of Micro-injection Molding

    Science.gov (United States)

    Nguyen-Chung, Tham; Jüttner, Gábor; Pham, Tung; Mennig, Günter

    2008-07-01

    Growing demands in the manufacturing of micro and precision components in plastics require new concepts for molding machines and micro molds on the one hand. On the other hand, a deeper understanding of the filling and solidification process in a micro mold is indispensable. In this work, the filling process of a micro spiral was analyzed by modeling the compressible flow using pressure dependent viscosity and adjusted heat transfer coefficients. At the same time, experimental filling studies were carried out on an accurately controlled micro-injection molding machine. Based on the relationship between the injection pressure and the filling degree, essential factors for the quality of the simulation can be identified. It can be shown that the flow behavior of the melt in a micro cavity of high aspect ratio is extremely dependent on the melt compressibility in the injection cylinder which needs to be considered in the simulation in order to predict an accurate flow rate. Moreover, the heat transfer coefficients between the melt and the mold wall vary significantly when changing cavity thickness and processing conditions. It is believed that a pressure dependent model for the heat transfer coefficient would be able to improve the quality of the process simulation.

  7. Measuring mechanical stresses on inserts during injection molding

    Directory of Open Access Journals (Sweden)

    Martina Heinle

    2015-05-01

    Full Text Available Assembly molding presents an interesting approach to innovative product solutions. Here, individual components can be simultaneously positioned, affixed, and provided with a casing. However, while overmolding elements in the mold cavity with hot polymer melt, high mechanical loads occur on, in some cases, very sensitive components such as electronic devices. For the design of such systems, it is important to know these stresses, the influences on their quantities, and mathematical options for their prediction. In this article, a new measurement method for determining the forces acting on a small element in the cavity during the injection molding process in three dimensions is presented. Therefore, a new installation method for a force sensor was developed. The results in this article concentrate on force changes during one molding cycle. Our research shows that there are different mechanical load spectra in the different phases of the molding process. For example, the force component in flow direction on an element in the cavity is positive in the direction of the flow during filling. However, after the filling step, the force becomes negative due to the contraction of the injected material and results in a continuously increasing permanent force.

  8. Computer Texture Mapping for Laser Texturing of Injection Mold

    Directory of Open Access Journals (Sweden)

    Yongquan Zhou

    2014-04-01

    Full Text Available Laser texturing is a relatively new multiprocess technique that has been used for machining 3D curved surfaces; it is more flexible and efficient to create decorative texture on 3D curved surfaces of injection molds so as to improve the surface quality and achieve cosmetic surface of molded plastic parts. In this paper, a novel method of laser texturing 3D curved surface based on 3-axis galvanometer scanning unit has been presented to prevent the texturing of injection mold surface from much distortion which is often caused by traditional texturing processes. The novel method has been based on the computer texture mapping technology which has been developed and presented. The developed texture mapping algorithm includes surface triangulation, notations, distortion measurement, control, and numerical method. An interface of computer texture mapping has been built to implement the algorithm of texture mapping approach to controlled distortion rate of 3D texture math model from 2D original texture applied to curvature surface. Through a case study of laser texturing of a high curvature surface of injection mold of a mice top case, it shows that the novel method of laser texturing meets the quality standard of laser texturing of injection mold.

  9. An investigation into the injection molding of PMR-15 polyimide

    Science.gov (United States)

    Colaluca, M. A.

    1984-01-01

    The chemorheological behavior of the PRM-15 molding compounds were characterized, the range of suitable processing parameters for injection molding in a reciprocating screw injection molding machine was determined, and the effects of the injection molding processing parameters on the mechanical properties of molded PMR-15 parts were studied. The apparatus and procedures for measuring viscosity and for determining the physical response of the material during heating are described. Results show that capillary rheometry can be effectively used with thermosets if the equipment is designed to overcome some of the inherent problems of these materials. A uniform temperature was provided in the barrel by using a circulating hot oil system. Standard capillary rheometry methods can provide the dependence of thermoset apparent viscosity on shear rate, temperature, and time. Process conditions resulting in complete imidization should be carefully defined. Specification of controlled oven temperature is inadequate and can result in incomplete imidization. For completely imidized PMR-15 heat at 15 C/min melt flow without gas evolution occurs in the temperature range of 325 C to 400 C.

  10. An in-mold packaging process for plastic fluidic devices.

    Science.gov (United States)

    Yoo, Y E; Lee, K H; Je, T J; Choi, D S; Kim, S K

    2011-01-01

    Micro or nanofluidic devices have many channel shapes to deliver chemical solutions, body fluids or any fluids. The channels in these devices should be covered to prevent the fluids from overflowing or leaking. A typical method to fabricate an enclosed channel is to bond or weld a cover plate to a channel plate. This solid-to-solid bonding process, however, takes a considerable amount of time for mass production. In this study, a new process for molding a cover layer that can enclose open micro or nanochannels without solid-to-solid bonding is proposed and its feasibility is estimated. First, based on the design of a model microchannel, a brass microchannel master core was machined and a plastic microchannel platform was injection-molded. Using this molded platform, a series of experiments was performed for four process or mold design parameters. Some feasible conditions were successfully found to enclosed channels without filling the microchannels for the injection molding of a cover layer over the plastic microchannel platform. In addition, the bond strength and seal performance were estimated in a comparison with those done by conventional bonding or welding processes.

  11. Mold and mycotoxin problems encountered during malting and brewing.

    Science.gov (United States)

    Wolf-Hall, Charlene E

    2007-10-20

    Fusarium infections in grains can have severe effects on malt and beer. While some degree of Fusarium mycotoxins, such as deoxynivalenol, present in infected barley may be lost during steeping, the Fusarium mold is still capable of growth and mycotoxin production during steeping, germination and kilning. Therefore, detoxification of grain before malting may not be practical unless further growth of the mold is also prevented. Methods to reduce the amount of mold growth during malting are needed. Physical, chemical and biological methods are reviewed. Irradiation looks very promising as a means to prevent Fusarium growth during malting, but the effect on the surviving mold to produce mycotoxins and the effect on malt quality needs further study. Chemical treatments such as ozonation, which would not leave residual chemical in the beer also appear to be promising. Although biological control methods may be desirable, due to the use of "natural" inhibition, the effects of these inhibitors on malt and beer quality requires further investigation. It may also be possible to incorporate detoxifying genes into fermentation yeasts, which would result in detoxification of the wort when mold growth is no longer a problem. Development of these types of technological interventions should help improve the safety of products, such as beer, made from Fusarium infected grain.

  12. Long fiber polymer composite property calculation in injection molding simulation

    Science.gov (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin

    2013-05-01

    Long fiber filled polymer composite materials have attracted a great attention and usage in recent years. However, the injection and compression molded long fiber composite materials possess complex microstructures that include spatial variations in fiber orientation and length. This paper presents the recent implemented anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation distribution[1] and a newly developed fiber breakage model[2] for predicting fiber length distribution in injection and compression molding simulation, and Eshelby-Mori-Tanaka model[3,4] with fiber-matrix de-bonding model[5] have been implemented to calculate the long fiber composite property distribution with predicted fiber orientation and fiber length distributions. A validation study on fiber orientation, fiber breakage and mechanical property distributions are given with injection molding process simulation.

  13. Modeling of Mold Filling and Solidification in Lost Foam Casting

    Institute of Scientific and Technical Information of China (English)

    Fengjun LI; Houfa SHEN; Baicheng LIU

    2003-01-01

    Based on the characteristics of the lost foam casting (LFC) and the artificial neural network technique, a mathematicalmodel for the simulation of the melt-pattern interface movement during the mold filling of LFC has been proposed andexperimentally verified. The simulation results are consistent with the experiments in both the shapes of melt frontand filling sequences. According to the calculated interface locations, the fluid flow and the temperature distributionsduring the mold filling and solidification processes were calculated, and the shrinkage defect of a lost foam ductileiron casting was predicted by considering the mold wall movement in LFC. The simulation method was applied tooptimize the casting design of lost foam ductile iron castings. It is shown that the model can be used for the defectsprediction and for casting design optimization in the practical LFC production.

  14. Application of Vacuum Drying to Silica Sol Ceramic Mold

    Institute of Scientific and Technical Information of China (English)

    Ming ZENG; Xinqiang YUAN; Baoluo SHEN; Yunqiu ZHENG

    2008-01-01

    Silica sol ceramic mold was made at room temperature with JN-30 silica sol, silica powder and NH4Cl. It is found that the harden time of silica sol ceramic mold is only 0.5 to 1.5 h under the amount of NH4CI solution of 7% to 8% with 15% concentration, and less surface cracks occur by using vacuum drying. The proper vacuum drying process parameters: vacuum drying temperature is 80 to 100℃, drying time is 5 h and vacuum is 0.06 to 0.07 MPa. The harden mechanics, vacuum drying mechanics and the reason of less surface cracks of silica sol ceramic mold by vacuum drying were also analyzed in this paper.

  15. Influence of melt mixer on injection molding of thermoset elastomers

    Science.gov (United States)

    Rochman, Arif; Zahra, Keith

    2016-10-01

    One of the drawbacks in injection molding is that the plasticizing screw is short such that polymers having high concentrations of additives, such as thermoset elastomers, might not mix homogeneously within the short period of time during the plasticizing stage. In this study, various melt mixers inside the nozzle chamber, together forming a mixing nozzle, were developed. Three different materials were investigated, namely nitrile butadiene rubber (NBR), ethylene propylene-diene monomer (EPDM) and fluorocarbon (FKM). The use of these melt mixers resulted in better homogeneity and properties of the molded parts despite a curing time reduction of 10 s. This was due to the increase in mixing and shearing introduced a higher rate of crosslinking formation in the molded parts.

  16. Injection Molding and its application to drug delivery.

    Science.gov (United States)

    Zema, Lucia; Loreti, Giulia; Melocchi, Alice; Maroni, Alessandra; Gazzaniga, Andrea

    2012-05-10

    Injection Molding (IM) consists in the injection, under high pressure conditions, of heat-induced softened materials into a mold cavity where they are shaped. The advantages the technique may offer in the development of drug products concern both production costs (no need for water or other solvents, continuous manufacturing, scalability, patentability) and technological/biopharmaceutical characteristics of the molded items (versatility of the design and composition, possibility of obtaining solid molecular dispersions/solutions of the active ingredient). In this article, process steps and formulation aspects relevant to IM are discussed, with emphasis on the issues and advantages connected with the transfer of this technique from the plastics industry to the production of conventional and controlled-release dosage forms. Moreover, its pharmaceutical applications thus far proposed in the primary literature, intended as either alternative manufacturing strategies for existing products or innovative systems with improved design and performance characteristics, are critically reviewed.

  17. Injection molding tools with micro/nano-meter pattern

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to methods for embedded a micrometer and/or nanometer pattern into an injection molding tool. In a first main aspect, a micro/nanometer structured imprinting device is applied in, or on, an active surface so as to transfer the micro/nanometer patterned structure...... to the tool while the imprinting device is, at least partly, within a cavity of the injection molding tool. In a second main aspect, a base plate with a micro/nanometer structured pattern positioned on an upper part is positioned on the active surface within the tool, the lower part of the base plate facing...... the tool, the active surface receiving the base plate being non-planar on a macroscopic scale. Both aspects enable a simple and effective way of transferring the pattern, and the pattern may be transferred on the active working site of tool immediately prior to molding without the need for extensive...

  18. Treatment principles for the management of mold infections.

    Science.gov (United States)

    Kontoyiannis, Dimitrios P; Lewis, Russell E

    2014-11-06

    Survival rates among immunocompromised patients with invasive mold infections have markedly improved over the last decade with earlier diagnosis and new antifungal treatment options. Yet, increasing antifungal resistance, breakthrough infections with intrinsically resistant fungi, and potentially life-threatening adverse effects and drug interactions are becoming more problematic, especially with prolonged therapy. Evidence-based recommendations for treating invasive aspergillosis and mucormycosis provide excellent guidance on the initial workup and treatment of these molds, but they cannot address all of the key management issues. Herein, we discuss 10 general treatment principles in the management of invasive mold disease in immunocompromised patients and discuss how these principles can be integrated to develop an effective, individualized treatment plan. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  19. Permanent Mold Casting of JIS-AC4C Aluminum Alloy Using a Low-Temperature Mold

    Science.gov (United States)

    Yamagata, Hiroshi; Nikawa, Makoto

    2011-01-01

    Permanent mold casting using mold temperatures below 200° C was conducted to obtain a high-strength, thin-walled casting. Al-7.36 mass% Si -0.18 Cu- 0.27Mg-0.34Fe alloy JIS-AC4C was cast using a bottom pouring cast plan. The product had a rectangular tube shape (70 mm W x 68 mm D x 180 mm H) with wall thicknesses of 1, 3 and 5 mm. The effect of heat insulation at the melt path was compared when using a sand runner insert and when using a steel runner insert as well as a powder mold release agent. Fine microstructures were observed in the casting. The smaller the thickness, the higher the hardness with smaller secondary dendrite arm spacing (SDAS). However, the hardness and the SDAS were unaffected by the mold temperature. It was proposed that the avoidance of the formation of primary α dendrite at the melt path generates a higher strength casting with adequate mold filling.

  20. Use of the smart tongue to monitor mold growth and discriminate between four mold species grown in liquid media

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Guangying, E-mail: zhaogy-user@163.com [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, Hangzhou 310035 (China); Lin Xiaona; Dou Wenchao; Tian Shiyi; Deng Shaoping; Shi Jinqin [Food Safety Key Lab of Zhejiang Province, Department of Food Quality and Safety, Zhejiang Gongshang University, Hangzhou 310035 (China)

    2011-04-01

    A novel voltammetric electronic tongue, smart tongue, was employed to monitor the growth of mold and to differentiate between four types of mold grown in liquid medium. Principal component analysis (PCA) was used to extract the relevant information obtained by the smart tongue. Reference growth curves were based on measurements of dry weight and pH. The growth detected by the smart tongue was basically consistent with that observed by the measurement of dry weight and pH. The optimal combinations of electrodes and frequencies for monitoring growth were as follows: for Aspergillus, both the Pt and Au electrodes at 1 Hz, 10 Hz and 100 Hz; for Penicillium, the Pt and W electrodes at 100 Hz; for Mucor, the Pt, Pd and W electrodes at the three frequency segments; for Rhizopus, the Pd, Ti and Ag electrodes at the three frequency segments. The Ag electrode at 10 Hz or 100 Hz frequency could differentiate well between the four types of mold for culturing 6 h in the liquid media. Therefore, the smart tongue has a promising future as a modern rapid analytical technology for the real time detection of the growth of mold and for the classification model of mold.

  1. 240 Mold Sensitization in Chronic Rhinosinusitis Patients

    Science.gov (United States)

    Gawlik, Radoslaw; Czecior, Eugeniusz

    2012-01-01

    Background It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allergens could be linked to the presence and persistence of asthma, rhinitis and atopic dermatitis. Mold sensitization is a risk factor for development and deterioration of upper airway allergy, especially chronic rhinosinusitis. We addressed the incidence of mold allergy measured as specific IgE to molds and skin prick tests in chronic sinusitis patients. We assessed prevalence of allergic reactions to mould among surgery treated chronic sinusitis patients. Methods A group of 28 chronic sinusitis patients after surgery were included into the study. Routine medical examination, skin prick tests with common inhaled allergens and extended mold panel (Alternaria alternate, Cladosporium herbarium, Aspergilus fumigatus, Candida albicans, Mucor mucedo, Botrytis cinerea, Rhisopus nigricans, Penicilliumi notatum, Fusarum moniliforme Pullularia pullulans (Allergopharma, Germany), tIgE, asIgE measurement were performed (Phadia, Sweden). All investigated patients were consulted by laryngologist and mycological examination was performed. Results We found that sensitization to at least one allergen was present in 43.8(14/32) of sinusitis patients. The most prevalent was sensitization to house dust mite Dermatophagoides pt., found in 21.8 % (7/32) patients. Positive results of skin prick tests with Candida albicans we observed in 18.8% (6/32), with Alternaria alternate in 15,6% (5/32), Cladosporium herbarium in 6,3% (2/32), Aspergilus fumigatus in 3,13 % (1/32). None of investigated patients presented sensitization to other mold allergens. Microbiological methods demonstrated fungal infection only in 2 patients. Conclusions Almost half of chronic sinusitis patients presented sensitization to at least one allergen. Fungal allergy is relatively rare in chronic sinusitis patients.

  2. Relações hídricas de inflorescências cortadas de ave-do-paraíso (Strelitzia reginae Ait.

    Directory of Open Access Journals (Sweden)

    Mônica M. Campanha

    1997-05-01

    Full Text Available A absorção e o transporte de água pelas flores cortadas mantidas em vaso podem ser diminuídos ou interrompidos devido à obstrução do xilema, acarretando murchamento e senescência de pétalas e sépalas. O presente trabalho teve como objetivo avaliar o efeito de cortes a cada dois dias, na base de hastes de inflorescências de ave-do-paraíso sobre o teor relativo de água de brácteas e sépalas, longevidade e número de floretes abertos. Nas hastes não cortadas, observou-se redução de 3% no teor de água da bráctea e 9,4% nas sépalas após 7 dias em vaso à temperatura de 2SOC. O corte periódico da base das hastes manteve estável o teor relativo de água, cerca de 89,1% na bráctea e 93,9% nas sépalas até 9 dias após a colheita em vaso. O corte periódico aumentou em 49% a longevidade pós-colheita da inflorescência e elevou de 1,6 para 2,7 o número de floretes abertos.

  3. FIBER ORIENTATION IN INJECTION MOLDED LONG CARBON FIBER THERMOPLASTIC COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Nguyen, Ba Nghiep; Mathur, Raj N.; Sharma, Bhisham; Sangid, Michael D.; Costa, Franco; Jin, Xiaoshi; Tucker III, Charles L.; Fifield, Leonard S.

    2015-03-23

    A set of edge-gated and center-gated plaques were injection molded with long carbon fiber-reinforced thermoplastic composites, and the fiber orientation was measured at different locations of the plaques. Autodesk Simulation Moldflow Insight (ASMI) software was used to simulate the injection molding of these plaques and to predict the fiber orientation, using the anisotropic rotary diffusion and the reduced strain closure models. The phenomenological parameters of the orientation models were carefully identified by fitting to the measured orientation data. The fiber orientation predictions show very good agreement with the experimental data.

  4. Smart plastic functionalization by nanoimprint and injection molding

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Thamdrup, Lasse Højlund; Smistrup, Kristian

    2015-01-01

    In this paper, we present a route for making smart functionalized plastic parts by injection molding with sub-micrometer surface structures. The method is based on combining planar processes well known and established within silicon micro and sub-micro fabrication with proven high resolution...... the pattern. With this approach, we demonstrate the transfer of down to 140 nm wide holes on large areas with good structure fidelity on an injection molding steel insert. The durability of the sub-micrometer structures on the inserts have been investigated by running two production series of 102,000 and 73...

  5. Fabrication of Functional Plastic Parts Using Nanostructured Steel Mold Inserts

    Directory of Open Access Journals (Sweden)

    Nicolas Blondiaux

    2017-06-01

    Full Text Available We report on the fabrication of sub-micro and nanostructured steel mold inserts for the replication of nanostructured immunoassay biochips. Planar and microstructured stainless steel inserts were textured at the sub-micron and nanoscale by combining nanosphere lithography and electrochemical etching. This allowed the fabrication of structures with lateral dimensions of hundreds of nanometers and aspect ratios of up to 1:2. Nanostructured plastic parts were produced by means of hot embossing and injection molding. Surface nanostructuring was used to control wettability and increase the sensitivity of an immunoassay.

  6. Study on Antigravity Mold Filling by Conservative Scalar Method

    Institute of Scientific and Technical Information of China (English)

    李日; 王友序; 杨根仓; 毛协民

    2003-01-01

    By SIMPLE method and Van-Leer scheme, a program on numerical simulation for 3D mold filling has been developed. The fluid flow field of gas and liquid is calculated in couples by a single phase N-S equation using SIMPLE method, and free surface control equation is handied by Van-Leer scheme. Then it is verified by an anti-gravity mold filling of thin wall plate. In order to demonstrate its ability to simulate 3D casting, an anti-gravity mould filling of a cube is computed by the program.

  7. Biological Control of Olive Green Mold in Agaricus bisporus Cultivation.

    Science.gov (United States)

    Tautorus, T E; Townsley, P M

    1983-02-01

    Successful methods to control the damaging weed mold Chaetomium olivaceum (olive green mold) in mushroom beds are not presently known. An attempt was made to control C. olivaceum by biological means. A thermophilic Bacillus sp. which showed dramatic activity against C. olivaceum on Trypticase soy agar (BBL Microbiology Systems)-0.4% yeast extract agar plates was isolated from commercial mushroom compost (phase I). When inoculated into conventional and hydroponic mushroom beds, the bacillus not only provided a significant degree of protection from C. olivaceum, but also increased yields of Agaricus bisporus.

  8. PROTEÇÃO DOS ACIONISTAS MINORITÁRIOS NAS SOCIEDADES POR AÇÕES DE CAPITAL ABERTO: PANORAMA DAS PRINCIPAIS MEDIDAS ADMINISTRATIVAS E JUDICIAIS

    Directory of Open Access Journals (Sweden)

    Arthur Giovanardi Dozza

    2014-01-01

    Full Text Available A atividade empresarial é uma das maiores fontes de enriquecimento de um país, gerando, além de emprego e tributos, lucro para seus acionistas. Por isto, se mostra indispensável um estudo mais aprofundando dos instrumentos que possam vir a ser utilizados pelos acionistas minoritários, já que estão sempre contando com a benevolência dos interesses do grupo controlador. Serão tratadas as medidas administrativas e judiciais que o acionista minoritário terá o direito de valer-se no caso de ocorrência de ilegalidade ou injustiça ou caso não esteja satisfeito com alguma medida que seja tomada para o prejudicar indiretamente. Há, sem dúvidas, interesse notório na matéria, já que a sociedade por ações aceita qualquer um que esteja interessado em investir suas economias em ações de companhias abertas deverá saber.Ressalva-se que não há o intuito de esgotar o assunto sobre o tema. O objetivo é o de analisar, em tópicos, as peculiaridades dos instrumentos mais utilizados pelos acionistas minoritários na busca de equilíbrio quando da ocorrência da violação de seus direitos.

  9. Materiais para modelagem: avaliacão dos tempos de presa, das resistências à tração e compressão e das particulas (MEV = Materials for molding: assessing the setting time, tensile and compressive strengths, and particles (SEM

    Directory of Open Access Journals (Sweden)

    Casemiro, Luciana Assirati

    2006-01-01

    Full Text Available Este trabalho comparou os tempos de presa inicial e final e as resistências à tração diametral e compressão de gessos utilizados em odontologia (natural, sintético e reforçado com resina. Os ensaios mecânicos foram realizados nos tempos de 1h e 24h após a manipulação, sendo os resultados submetidos à análise estatística (Anova two way, Tuckey P < 0,05. As partículas foram analisadas em microscópio eletrônico de varredura, procurando-se estabelecer correlações com as propriedades avaliadas. Observou-se que o gesso natural possui propriedades mecânicas superiores e maior tempo de presa que os demais. As partículas do mesmo material se apresentaram maiores que as dos outros gessos, sendo as do gesso reforçado com resina as menores de todas. Conclui-se que há relação direta entre o tamanho das partículas e as propriedades avaliadas, como pode ser observado, por exemplo, para o gesso natural (maiores partículas e maiores valores nos testes realizados

  10. Evaluation of the mold-filling ability of alloy melt in squeeze casting

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mold-filling ability of alloy melt in squeeze casting process was evaluated by means of the maximum length of Archimedes spiral line. A theoretical evaluating model to predict the maximum filling length was built based on the flowing theory of the incompressible viscous fluid. It was proved by experiments and calculations that the mold-filling pressure and velocity are prominent influencing factors on the mold-filling ability of alloy melt. The mold-filling ability increases with the increase of the mold-filling pressure and the decrease of the proper mold-filling velocity. Moreover, the pouring temperature relatively has less effect on the mold-filling ability under the experimental conditions. The maximum deviation of theoretical calculating values with experimental results is less than 15%. The model can quantitatively estimate the effect of every factor on the mold-filling ability.

  11. Polymer microlens array integrated with imaging sensors by UV-molding technique

    Science.gov (United States)

    Lai, Jianjun; Zhao, Yue; Ke, Caijun; Yi, Xinjian; Zhang, TianXu

    2005-01-01

    Fabrication of Polymer microlens array based on UV-molding techniques is presented. UV-molding enables for the integration of polymer microlens array on top of arbitrary substrates like glass, silicon other polymeric films. In this technique, photoresist or glass mold is first fabricated by conventional photolithnic method and subsequently served as transparent replication tool. UV curable polymer resin is then coated on patterned or unpatterned substrates and a contact mask aligner is used to align substrates and replication mold tool and then make the mold immersed into the resin. Replication of polymer on substrates is achieved by UV photopolymerisation of the resin. Resin thickness and gap distance between mold and substrate are carefully controlled in order to obtain acceptable thickness of cured polymer base. The UV molding technique was used to molding of a polymer film carring microlens array on the surface of an experimental CCD imaging sensor chip in this paper to enhance its fill factor and sensitivity.

  12. Finite element stress analysis of a compression mold. Final report. [Using SASL and WILSON codes

    Energy Technology Data Exchange (ETDEWEB)

    Watterson, C.E.

    1980-03-01

    Thermally induced stresses occurring in a compression mold during production molding were evaluated using finite element analysis. A complementary experimental stress analysis, including strain gages and thermocouple arrays, verified the finite element model under typical loading conditions.

  13. Application of statistical methods for analyzing the relationship between casting distortion, mold filling, and interfacial heat transfer in sand molds

    Energy Technology Data Exchange (ETDEWEB)

    Y. A. Owusu

    1999-03-31

    This report presents a statistical method of evaluating geometric tolerances of casting products using point cloud data generated by coordinate measuring machine (CMM) process. The focus of this report is to present a statistical-based approach to evaluate the differences in dimensional and form variations or tolerances of casting products as affected by casting gating system, molding material, casting thickness, and casting orientation at the mold-metal interface. Form parameters such as flatness, parallelism, and other geometric profiles such as angularity, casting length, and height of casting products were obtained and analyzed from CMM point cloud data. In order to relate the dimensional and form errors to the factors under consideration such as flatness and parallelism, a factorial analysis of variance and statistical test means methods were performed to identify the factors that contributed to the casting distortion at the mold-metal interface.

  14. Quantifying mold biomass on gypsum board: Comparison of ergosterol and beta-N-acetylhexosaminidase as mold biomass parameters

    DEFF Research Database (Denmark)

    Reeslev, M.; Miller, M.; Nielsen, Kristian Fog

    2003-01-01

    Two mold species, Stachybotrys chartarum and Aspergillus versicolor, were inoculated onto agar overlaid with cellophane, allowing determination of a direct measurement of biomass density by weighing. Biomass density, ergosterol content, and beta-N-acetylhexosaminidase (3.2.1.52) activity were...... monitored from inoculation to stationary phase. Regression analysis showed a good linear correlation to biomass density for both ergosterol content and beta-N-acetylhexosaminidase activity. The same two mold species were inoculated onto wallpapered gypsum board, from which a direct biomass measurement...... density from ergosterol content and beta-N-acetylhexosaminidase activity were determined. The CFs were used to estimate the biomass density of the molds grown on gypsum board. The biomass densities estimated from ergosterol content and beta-N-acetylhexosaminidase activity data gave similar results...

  15. The effect of mold materials on the overlay accuracy of a roll-to-roll imprinting system using UV LED illumination within a transparent mold

    Science.gov (United States)

    Choi, Sungwoo; Kook, YunHo; Kim, ChulHo; Yoo, SoonSung; Park, Kwon-Shik; Kim, Seok-min; Kang, Shinill

    2016-06-01

    Although several studies on the roll-to-roll (R2R) imprinting process have reported achieving flexible electronics, improving the alignment accuracy in the overlay process of R2R imprinting is recognized as the biggest problem for the commercialization of this technology. For an overlay technique with high alignment accuracy, it is essential to develop a roll mold with high positional accuracy. In this study, a method for fabricating a roll mold with high positional accuracy is proposed by wrapping a thin glass substrate flexible mold around the transparent roll base, because it can provide higher mechanical strength and thermal stability than a conventional polymer substrate. To confirm the usability of the proposed process, the prepared roll mold was used to fabricate a test pattern of thin-film transistor backplane for a rollable display. The positional and overlay accuracy of the roll mold with the proposed thin glass substrate flexible mold were compared with the roll mold with a conventional polymer substrate flexible mold. Large-area transparent flexible molds with a size of 470  ×  370 mm were fabricated by an ultraviolet (UV) imprinting process on thin glass and polyethylene terephthalate substrates, and these flexible molds were wrapped around a roll base of 125 mm radius through a precision alignment process. After an anti-adhesion treatment and the wrapping process, the roll mold with the polymer substrate showed a ~180 μm positional error, whereas the thin glass substrate showed a ~30 μm positional error. After the overlay process using the R2R imprinting system with the alignment system, an average overlay error of ~3 μm was obtained when the thin glass flexible wrapped roll mold was used, whereas a ~22 μm overlay error was obtained when the polymer substrate flexible wrapped roll mold was used.

  16. Comparison Of Simulation Results When Using Two Different Methods For Mold Creation In Moldflow Simulation

    Directory of Open Access Journals (Sweden)

    Kaushikbhai C. Parmar

    2015-08-01

    Full Text Available Simulation gives different results when using different methods for the same simulation. Autodesk Moldflow Simulation software provide two different facilities for creating mold for the simulation of injection molding process. Mold can be created inside the Moldflow or it can be imported as CAD file. The aim of this paper is to study the difference in the simulation results like mold temperature part temperature deflection in different direction time for the simulation and coolant temperature for this two different methods.

  17. Injection molding of iPP samples in controlled conditions and resulting morphology

    Energy Technology Data Exchange (ETDEWEB)

    Sessa, Nino, E-mail: ninosessa.ns@gmail.com; De Santis, Felice, E-mail: fedesantis@unisa.it; Pantani, Roberto, E-mail: rpantani@unisa.it [Department of Industrial Engineering, University of Salerno, 84084 Fisciano (Italy)

    2015-12-17

    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy.

  18. Theoretical Analysis of the Solidification of Aluminum Alloy Billet in Air-Slip DC Mold

    Institute of Scientific and Technical Information of China (English)

    于赟; 马乃恒; 许振明; 李建国

    2004-01-01

    Based on the heat transfer analysis of Air-Slip DC mold, a numerical model was presented to study the quantitative relationships between critical solidification layer and casting rate, pouring temperature and mold cooling ability etc. The analytical results show that the Air-Slip mold heat transfer condition plays important roles on choices of a casting rate and the pouring temperature, and that the product of billet diameter and casting rate is a certain constant under a certain condition of the mold.

  19. Mold Species in Dust from the International Space Station Identified and Quantified by Mold Specific Quantitative PCR

    Science.gov (United States)

    Vesper, Stephen J.; Wong, Wing; Kuo, C. Mike; Pierson, Duane L.

    2008-01-01

    Dust was collected over a period of several weeks in 2007 from various HEPA filters in the U.S. Laboratory Module of the International Space Station (ISS). The dust was returned on the Space Shuttle Atlantis, mixed, sieved, and the DNA was extracted. Using a DNA-based method called mold specific quantitative PCR (MSQPCR), 39 molds were measured in the dust. Opportunistic pathogens Aspergillus flavus and A. niger and toxin producers Penicillium chrysogenum and P. brevicompactum were found at relatively high concentrations (compared to U.S. homes). No cells of the opportunistic pathogens A. fumigatus, A. terreus, Fusarium solani or Candida albicans were detected.

  20. MoldFlow软件在梳子注射模结构改进及其成型缺陷分析中的应用%The Application of MoldFlow Software in the Structure Improvement and Analysis of forming Defects of Comb Injection Molding

    Institute of Scientific and Technical Information of China (English)

    陈叶娣

    2012-01-01

    MoldFlow software is applied to improve the mold structure and solve molding defects according to the problems of comb injection molding during trying mold. These will be provided some valuable references. Aunusual power is provided for the wide application of MoldFlow software in the design of injection mold.%根据梳子注射模在试模过程中存在的一些问题,采用MoldFlow软件进行分析,为改进模具结构、解决其成型缺陷提供有价值的参考。

  1. A rapid colorimetric assay for mold spore germination using XTT tetrazolium salt

    Science.gov (United States)

    Carol A. Clausen; Vina W. Yang

    2011-01-01

    Current laboratory test methods to measure efficacy of new mold inhibitors are time consuming, some require specialized test equipment and ratings are subjective. Rapid, simple quantitative assays to measure the efficacy of mold inhibitors are needed. A quantitative, colorimetric microassay was developed using XTT tetrazolium salt to metabolically assess mold spore...

  2. Experimental Investigation of Comparative Process Capabilities of Metal and Ceramic Injection Molding for Precision Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian;

    2016-01-01

    The purpose of this paper is to make a comparative study on the process capabilities of the two branches of the powder injection molding (PIM) process—metal injection molding (MIM) and ceramic injection molding (CIM), for high-end precision applications. The state-of-the-art literature does not m...

  3. Validation of precision powder injection molding process simulations using a spiral test geometry

    DEFF Research Database (Denmark)

    Marhöfer, Maximilian; Müller, Tobias; Tosello, Guido

    2015-01-01

    Like in many other areas of engineering, process simulations find application in precision injection molding to assist and optimize the quality and design of precise products and the molding process. Injection molding comprises mainly the manufacturing of plastic components. However, the variant ...

  4. 40 CFR Appendix - Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC...

    Science.gov (United States)

    2010-07-01

    ... Limits for Open Molding, Centrifugal Casting, and SMC Manufacturing Operations Where the Standards Are..., Table 5 Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC... casting—CR/HS 3,4 A vent system that moves heated air through the mold 27 lb/ton. 8. Centrifugal...

  5. The history of molded fiber packaging: a 20th century pulp story

    NARCIS (Netherlands)

    Wever, R.; Twede, D.

    2007-01-01

    Molded fiber packaging, which is also referred to as molded pulp packaging, has been around for a little over a hundred years now. From the first patent, dating from 1903, until approximately 25 years ago molded fiber packaging was a niche product used mainly for packing eggs. However, in the last t

  6. Differential allergy induction by molds found in water-damaged homes**

    Science.gov (United States)

    Molds are ubiquitous in the environment and exposures to molds contribute to various human diseases including allergic lung diseases. The Institute of Medicine reports (NAS, 2004) and World Health Organization guidelines (WHO, 2009) concluded that the role of molds in asthma indu...

  7. Three-dimensional numerical modeling of an induction heated injection molding tool with flow visualization

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido; Nielsen, Kaspar Kirstein

    2016-01-01

    Using elevated mold temperature is known to have a positive influence of final injection molded parts. Induction heating is a method that allow obtaining a rapid thermal cycle, so the overall molding cycle time is not increased. In the present research work, an integrated multi-turn induction hea...

  8. Injection molding of nanopatterned surfaces in the sub-micrometer range with induction heating aid

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano

    2014-01-01

    Replication of sub-micrometer structures by injection molding leads to special requirements for the mold in order to ensure proper replica and acceptable cycle time. This paper investigates the applicability of induction heating embedded into the mold for the improvement of nanopattern replicatio...

  9. Fabricación de piezas de fundición con grafito esferoidal en molde metálico

    Directory of Open Access Journals (Sweden)

    Urrestarazu, A.

    2013-10-01

    Full Text Available The features and suitability of high requirements ductile iron castings production using metallic moulds have been studied in the present work. The structural and mechanical properties of the produced castings have been analysed and compared to the corresponding ones but fabricated using green sand moulds according to a conventional production process. The higher cooling rate in the metallic moulds is the main cause for the appearance of the detected structural changes in castings. The mechanical and microstructural properties obtained directly on castings are remarkable due to the higher nodule count among other factors. Finally, the benefits and inconveniences found in this kind of production methodology using metallic moulds are also discussed.En este trabajo se estudia el empleo de moldes metálicos o permanentes para la fabricación de piezas de fundición esferoidal con elevados requerimientos funcionales y se analizan sus propiedades, comparándolas con piezas obtenidas utilizando moldes de arena de sílice, de acuerdo con las metodologías más habituales para este tipo de procesos. La elevada velocidad de solidificación y el posterior enfriamiento rápido de la austenita formada en estado sólido se erigen como los principales factores diferenciadores que originan las modificaciones estructurales detectadas en las piezas. Las propiedades físicas, mecánicas y microestructurales obtenidas directamente sobre pieza son destacables debido, entre otros aspectos, al gran número de esferoides grafíticos obtenidos en las piezas. Se discuten también las ventajas e inconvenientes encontrados en esta metodología de producción que emplea moldes fabricados con una aleación metálica específica.

  10. The Role of Molding Compound Microstructure for Packaging Reliability

    NARCIS (Netherlands)

    Fischer, H.R.; Nabi, H.S.; Weiss, L.; Gielen, A.W.J.

    2015-01-01

    Molding compounds are key materials to deliver well packaged reliable IC’s for demanding applications, such as automotive electronics. With shrinking sizes of IC’s and the increased requirements with respect to loading conditions, application environment and lifetime, the reliability of the

  11. Stability of FDTS monolayer coating on aluminum injection molding tools

    Energy Technology Data Exchange (ETDEWEB)

    Cech, Jiri [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345E, DK-2800 Kongens Lyngby (Denmark); Taboryski, Rafael, E-mail: rafael.taboryski@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345E, DK-2800 Kongens Lyngby (Denmark)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer We present novel and highly useful results on FDTS monolayer coating of aluminum. Black-Right-Pointing-Pointer The coating is particularly applicable for coating of prototyping injection molding tools, which often are made of Al. Black-Right-Pointing-Pointer We have demonstrated that the coating prevails in injection molding conditions and that the coating will prevent wear of the tools. - Abstract: We have characterized perfluorodecyltrichlorosilane (FDTS) molecular coating of aluminum molds for polymer replication via injection molding (IM). X-ray photoelectron spectroscopy (XPS) data, sessile drop contact angles with multiple fluids, surface energies and roughness data have been collected. Samples have been characterized immediately after coating, after more than 500 IM cycles to test durability, and after 7 months to test temporal stability. The coating was deposited in an affordable process, involving near room temperature gas phase reactions. XPS shows detectable fluorine presence on both freshly coated samples as well as on post-IM samples with estimated 30 at.% on freshly coated and 28 at.% on post-IM samples with more than 500 IM cycles with polystyrene (PS) and ABS polymer.

  12. Thermal modeling of wafer-based precision glass molding process

    Science.gov (United States)

    Hu, Yang; Shen, Lianguan; Zhou, Jian; Li, Mujun

    2016-10-01

    Wafer based precision glass optics manufacturing has been an innovative approach for combining high accuracy with mass production. However, due to the small ratio of thickness and diameter of the glass wafer, deformation and residual stress would be induced for the nonuniform temperature distribution in the glass wafer after molding. Therefore, thermal modelling of the heating system in the wafer based precision glass molding (PGM) process is of great importance in optimizing the heating system and the technique of the process. The current paper deals with a transient thermal modelling of a self-developed heating system for wafer based PGM process. First, in order to investigate the effect of radiation from the surface and interior of the glass wafer, the thermal modeling is simulated with a discrete ordinates radiation model in the CFD software FLUENT. Temperature distribution of the glass wafer obtained from the simulations is then used to evaluate the performance of heating system and investigate some importance parameters in the model, such as interior and surface radiation in glass wafer, thermal contact conductance between glass wafer and molds, thickness to diameter ratio of glass wafer. Finally, structure modification in the molding chamber is raised to decrease the temperature gradient in the glass wafer and the effect is significant.

  13. A Recurrent Neural Network for Warpage Prediction in Injection Molding

    Directory of Open Access Journals (Sweden)

    A. Alvarado-Iniesta

    2012-11-01

    Full Text Available Injection molding is classified as one of the most flexible and economical manufacturing processes with high volumeof plastic molded parts. Causes of variations in the process are related to the vast number of factors acting during aregular production run, which directly impacts the quality of final products. A common quality trouble in finishedproducts is the presence of warpage. Thus, this study aimed to design a system based on recurrent neural networksto predict warpage defects in products manufactured through injection molding. Five process parameters areemployed for being considered to be critical and have a great impact on the warpage of plastic components. Thisstudy used the finite element analysis software Moldflow to simulate the injection molding process to collect data inorder to train and test the recurrent neural network. Recurrent neural networks were used to understand the dynamicsof the process and due to their memorization ability, warpage values might be predicted accurately. Results show thedesigned network works well in prediction tasks, overcoming those predictions generated by feedforward neuralnetworks.

  14. Fiber-Based, Injection-Molded Optofluidic Systems

    DEFF Research Database (Denmark)

    Matteucci, Marco; Triches, Marco; Nava, Giovanni

    2015-01-01

    We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow...

  15. Advanced Polymer Composite Molding Through Intelligent Process Analysis and Control

    Science.gov (United States)

    2004-11-30

    In this project. process analysis of Resin Transfer Molding (RTM) was carried out and adaptive process control models were developed. In addition, a...aforementioned work in three separate sections: (1) process analysis and adaptive control modeling, (2) manufacturing of non-invasive sensor, end (3) list of publications resulting from this project.

  16. Precision glass molding: Toward an optimal fabrication of optical lenses

    Science.gov (United States)

    Zhang, Liangchi; Liu, Weidong

    2016-12-01

    It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carried out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable temperature variation, the glass viscosity can change from 105 to 1012 Pas due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxation in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.

  17. Ion channel recordings on an injection-molded polymer chip

    DEFF Research Database (Denmark)

    Tanzi, Simone; Matteucci, Marco; Christiansen, Thomas Lehrmann

    2013-01-01

    In this paper, we demonstrate recordings of the ion channel activity across the cell membrane in a biological cell by employing the so-called patch clamping technique on an injection-molded polymer microfluidic device. The findings will allow direct recordings of ion channel activity to be made u...

  18. On the Injection Molding of Nanostructured Polymer Surfaces

    DEFF Research Database (Denmark)

    Pranov, Henrik; Rasmussen, Henrik K.; Larsen, Niels Bent;

    2006-01-01

    Well-defined nano-topographies were prepared by electron-beam lithography and electroplated to form nickelshims. The surface pattern consisted of square pillars repeated equidistantly within the plane of the surface in a perpendicular arrangement. The width and distance between the squares both...... mold sub-micrometer surface structures in polymers mainly relates to adhesive energy between polymer and shim....

  19. Precision glass molding: Toward an optimal fabrication of optical lenses

    Science.gov (United States)

    Zhang, Liangchi; Liu, Weidong

    2017-03-01

    It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carried out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable temperature variation, the glass viscosity can change from 105 to 1012 Pas due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxation in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.

  20. Packing parameters effect on injection molding of polypropylene nanostructured surfaces

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard

    2012-01-01

    having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing...... to the polymer part was mainly influenced by packing pressure level and distance from the gate....

  1. Fast prototyping of injection molded polymer microfluidic chips

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Selmeczi, David; Larsen, Niels Bent

    2010-01-01

    , likely due to the resulting reduction in sidewall steepness. We employed the latter method for injection molding bondable polymer microfluidic chips with integrated conducting polymer electrode arrays that permitted the culture and on-chip analysis of cell spreading by impedance spectroscopy....

  2. Effective Control of Molds Using a Combination of Nanoparticles

    Science.gov (United States)

    Martínez-Castañón, Gabriel Alejandro; Slavin, Yael N.; Zhao, Wayne; Asnis, Jason; Häfeli, Urs O.

    2017-01-01

    Molds are filamentous fungi able to grow on a variety of surfaces, including constructed surfaces, food, rotten organic matter, and humid places. Mold growth is characterized by having an unpleasant odor in enclosed or non-ventilated places and a non-aesthetic appearance. They represent a health concern because of their ability to produce and release mycotoxins, compounds that are toxic to animals and humans. The aim of this study was to evaluate commercial nanoparticles (NPs) that can be used as an additive in coatings and paints to effectively control the growth of harmful molds. Four different NPs were screened for their antifungal activities against the mycotoxin producing mold strains Aspergillus flavus and A. fumigatus. The minimal inhibitory concentrations of the NPs were determined in broth media, whereas an agar diffusion test was used to assess the antimold activity on acrylic- and water-based paints. The cytotoxic activity and the inflammatory response of the NPs were also evaluated using the established human derived macrophage cell line THP-1. Results showed that a combination of mix metallic- and ZnO-NPs (50:10 μg/mL) effectively inhibited the fungal growth when exposed to fluorescent light. Neither cytotoxic effect nor inflammatory responses were recorded, suggesting that this combination can be safely used in humid or non-ventilated environments without any health concerns. PMID:28122038

  3. Injection molding tools with micro/nano-meter pattern

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to methods for embedded a micrometer and/or nanometer pattern into an injection molding tool. In a first main aspect, a micro/nanometer structured imprinting device is applied in, or on, an active surface so as to transfer the micro/nanometer patterned structure to t...

  4. Metal Injection Molding of Alloy 718 for Aerospace Applications

    Science.gov (United States)

    Ott, Eric A.; Peretti, Michael W.

    2012-02-01

    The metal injection molding process, used in the automotive, medical, and consumer markets for several decades, was investigated for application to superalloys for small, complex-shaped, aerospace components. With sufficient control on processing, inclusion risks, and chemistry, the process can successfully be applied to superalloy 718 components. Assessments included tensile and fatigue property evaluation, characterization of microstructure, and development of an AMS specification.

  5. Bestrijding Black Mold in geoculeerde rozenteelt 2008-2009

    NARCIS (Netherlands)

    Duyvesteijn, R.G.E.; Smits, A.P.; Werd, de H.A.E.; Breeuwsma, S.J.; Bent, van der J.; Meijer, H.; Kohrman, E.; Wijk, van D.; Boer, de M.

    2010-01-01

    Black Mold (Chalaropsis thielavioides) is een schimmel die in 2007 veel schade heeft veroorzaakt in de struikrozen. De schimmel infecteert de oculatiewond met als gevolg dat het oculatieoog niet aanslaat. Op sommige percelen ging tot wel 70% van de enten verloren. In een tweejarig PT project is onde

  6. A flexible mold for double curved precast concrete elements

    NARCIS (Netherlands)

    Schipper, H.R.; Vambersky, J.N.J.A.

    2010-01-01

    The manufacturing of double curved precast concrete elements is still expensive, due to the high costs and limited possibilities for repetitive use of the molds or formwork. The goal of a PhD project recently initiated at TU Delft is to develop a production method that overcomes these difficulties b

  7. QTLs for Snow Mold Disease Resistance in Creeping Bentgrass

    Science.gov (United States)

    Snow molds caused by Typhula spp. are the most economically important winter diseases of turfgrass in the northern and alpine regions of the United States and Canada. During winter, the psychrophilic pathogens take advantage of the weakened host plants at low temperatures under persistent snow cover...

  8. Leach and mold resistance of essential oil metabolites

    Science.gov (United States)

    Carol A. Clausen; Vina W. Yang

    2011-01-01

    Purified primary metabolites from essential oils were previously shown to be bioactive inhibitors of mold fungi on unleached Southern pine sapwood, either alone or in synergy with a second metabolite. This study evaluated the leachability of these compounds in Southern pine that was either dip- or vacuum-treated. Following laboratory leach tests, specimens were...

  9. Optimizing biomass blends for manufacturing molded packaging materials using mycelium

    Science.gov (United States)

    Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; 3) Extruded polys...

  10. Incipient flocculation molding: A new ceramic-forming technique

    Science.gov (United States)

    Arrasmith, Steven Reade

    Incipient Flocculation Molding (IFM) was conceived as a new near-net-shape forming technique for ceramic components. It was hypothesized that the development of a temperature-dependent deflocculant would result in a forming technique that is flexible, efficient, and capable of producing a superior microstructure with improved mechanical properties from highly reactive, submicron ceramic powders. IFM utilizes a concentrated, nonaqueous, sterically stabilized ceramic powder and/or colloidal suspension which is injected into a non-porous mold. The suspension is then flocculated by destabilizing the suspension by lowering the temperature. Flocculation is both rapid and reversible. Cooling to -20°C produces a green body with sufficient strength for removal from the mold. The solvent is removed from the green body by evaporation. The dried green body is subsequently sintered to form a dense ceramic monolith. This is the first ceramic forming method based upon the manipulation of a sterically-stabilized suspension. To demonstrate IFM, the process of grafting polyethylene glycol (PEG), with molecular weights from 600 to 8000, to alumina powders was investigated. The maximum grafted amounts were achieved by the technique of dispersing the alumina powders in molten polymer at 195°C. The ungrafted PEG was then removed by repeated centrifuging and redispersion in fresh distilled water. The rheological behavior of suspensions of the PEG-grafted powders in water, 2-propanol and 2-butanol were characterized. All of the aqueous suspensions were shear thinning. The PEG 4600-grafted alumina powder aqueous suspensions were the most fluid. Sample rods and bars were molded from 52 vol% PEG-grafted alumina suspensions in 2-butanol. The best results were obtained with a preheated aluminum mold lubricated with a fluorinated oil mold-release. The samples were dried, sintered, and their microstructure and density were compared with sintered samples dry pressed from the same alumina powder

  11. Applications of thin carbon coatings and films in injection molding

    Science.gov (United States)

    Cabrera, Eusebio Duarte

    In this research, the technical feasibility of two novel applications of thin carbon coatings is demonstrated. The first application consists of using thin carbon coatings on molds for molding ultra-thin plastic parts (coated nanoparticle thin films or nanopapers to create a conductive top layer. During this research, the technical feasibility of a new approach was proven which provides injection molding of ultra-thin parts at lower pressures, without the need of fast heating/fast cooling or other expensive mold modification. An in-house developed procedure by other members of our group, was employed for coating the mold surface using chemical vapor deposition (CVD) resulting in a graphene coating with carbide bonding to the mold surface. The coating resulted in a significant decrease of surface friction and consequently easiness of flow when compared to their uncoated counterparts. Thermoplastic polymers and their composites are a very attractive alternative but are hindered by the non-conductive nature of polymers. There are two general approaches used to date to achieve EMI shielding for plastic products. One is to spray a conductive metal coating onto the plastic surface forming a layer that must maintain its shielding effectiveness (SE), and its adhesion to the plastic throughout the expected life of the product. However, metal coatings add undesirable weight and tend to corrode over time. Furthermore, scratching the coating may create shielding failure; therefore, a protective topcoat may be required. The other approach is to use polymer composites filled with conductive fillers such as carbon black (CB), carbon nanofiber (CNF), and carbon nanotube (CNT). While conductive fillers may increase the electrical conductivity of polymer composites, the loading of such fillers often cannot reach a high level (coated nanoparticle thin films or nanopapers to create a conductive top layer. For many years, in-mold coating (IMC) has been commercially applied to Sheet

  12. Development of an open source software of quantitative analysis for radionuclide determination by gamma-ray spectrometry using semiconductor detectors; Desenvolvimento de um codigo computacional aberto de analise quantitativa para determinacao de radionuclideos por espectrometria gama com detectores semicondutores

    Energy Technology Data Exchange (ETDEWEB)

    Maduar, Marcelo Francis

    2010-07-01

    Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. (author)

  13. Solidification process and infrared image characteristics of permanent mold castings

    Science.gov (United States)

    Viets, Roman; Breuer, Markus; Haferkamp, Heinz; Kruessel, Thomas; Niemeyer, Matthias

    1999-03-01

    Interdependence between the development of temperature gradients at the solid-liquid interface during solidification of metals and the formation of local defects demands for thermal investigation. In foundry practice thermocouples are used to control the die's overall cooling-rate, but fluctuations in product quality still occur. Capturing FIR- thermograms after opening the die visualizes the state, when most thermal throughput has already flattened the temperature gradients in the mold. Rapid dissipation of heat from liquid metal to the mold during solidification forces further approach of the process investigation by slowing down the heat flux or the use of transparent mold material. Aluminum gravity casting experiments under technical vacuum conditions lead to decelerated solidification by suppression of convection and image sequences containing explicit characteristics that could be assigned to local shrinkage of the casting. Hence relevant clusters are extracted and thermal profiles are drawn from image series, pointing out correlations between feeding performance from the sink heads and the appearance of local defects. Tracing thermal processes in vacuum casting can scarcely be transferred to image data in foundry practice, since only little analogies exist between atmospheric and vacuum casting. The diagnosis of the casting process requires detection of the still closed mold using a transparent silica- aerogel sheet as part of the die. Hereby thermograms of the initial heat input are recorded by adapting a NIR-camera in addition to the FIR-unit. Thus the entire thermal compensation at the joint face for each casting is visualized. This experimental set-up is used for image sequence analysis related to the intermediate casting phases of mold filling, body formation and solidification shrinkage.

  14. Estudio experimental del llenado de moldes pulvimetalúrgicos

    Directory of Open Access Journals (Sweden)

    Istúriz, A.

    2005-12-01

    Full Text Available Die filling is the first step in the process of powder compaction. The density distribution depends of the powder characteristics and method of filling. In this work we present the first results obtained with different experimental methods of the filling. Results have been analyzed using a video system which permits the observation of the powder flow. The aim of the work is to determinate the effects of size, morphology and nature of the powder, as well as shoe speed, and die geometry on the apparent density distribution in industrial dies of complex geometry.

    En el proceso de conformado pulvimetalúrgico, la consolidación del polvo se inicia con el llenado del molde en el que se fabricará la preforma porosa, el cual está caracterizado por la distribución de densidades del polvo dentro del molde y depende tanto de las propiedades del mismo como del método de llenado utilizado. A continuación, presentamos los primeros resultados obtenidos mediante un montaje experimental que reproduce el llenado de moldes y que, empleando un sistema de video, permite analizar el flujo de las partículas durante el llenado. El objetivo es determinar el efecto del tamaño, naturaleza y morfología del polvo, así como el de la velocidad del cargador y la geometría del molde en la distribución de la densidad aparente en moldes industriales de geometría compleja.

  15. Molding Properties of Inconel 718 Feedstocks Used in Low-Pressure Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Fouad Fareh

    2016-01-01

    Full Text Available The impact of binders and temperature on the rheological properties of feedstocks used in low-pressure powder injection molding was investigated. Experiments were conducted on different feedstock formulations obtained by mixing Inconel 718 powder with wax-based binder systems. The shear rate sensitivity index and the activation energy were used to study the degree of dependence of shear rate and temperature on the viscosity of the feedstocks. The injection performance of feedstocks was then evaluated using an analytical moldability model. The results indicated that the viscosity profiles of feedstocks depend significantly on the binder constituents, and the secondary binder constituents play an important role in the rheological behavior (pseudoplastic or near-Newtonian exhibited by the feedstock formulations. Viscosity values as low as 0.06 to 2.9 Pa·s were measured at high shear rates and high temperatures. The results indicate that a feedstock containing a surfactant agent exhibits the best moldability characteristics.

  16. O papel da visão na aversão aos espaços abertos no labirinto em cruz elevado

    Directory of Open Access Journals (Sweden)

    Silvio Morato

    2006-01-01

    Full Text Available O labirinto em cruz elevado é um dos modelos mais usados no estudo da ansiedade, medo e fármacos que alteram esses estados. Apesar da simplicidade aparente do modelo, diversos são os fatores que afetam o comportamento de ratos submetidos a esse modelo. Além disso, não se conhece exatamente quais os estímulos ambientais são os desencadeadores da aversão nesse modelo. O presente trabalho sugere que, em estudos onde os estímulos auditivos e olfativos são controlados, a aversão em ratos é desencadeada pela visão. A hipótese de trabalho é que os mecanismos mediadores da aversão (e estados emocionais concomitantes são deflagrados pela entrada de luz e pela formação de imagens na retina dos animais. Para fundamentar essas hipóteses complementares, vários experimentos são analisados, cujos resultados favorecem uma, outra ou ambas as hipóteses. Finalmente, resultados obtidos com marcação da proteína c-Fos fornecem evidência neurofuncional que apóia as duas hipóteses sugeridas.

  17. Quantifying mold biomass on gypsum board: Comparison of ergosterol and beta-N-acetylhexosaminidase as mold biomass parameters

    DEFF Research Database (Denmark)

    Reeslev, M.; Miller, M.; Nielsen, Kristian Fog

    2003-01-01

    Two mold species, Stachybotrys chartarum and Aspergillus versicolor, were inoculated onto agar overlaid with cellophane, allowing determination of a direct measurement of biomass density by weighing. Biomass density, ergosterol content, and beta-N-acetylhexosaminidase (3.2.1.52) activity were...

  18. Measurement of casting parameters in ZnAlCu3 molds created by additive technology

    Directory of Open Access Journals (Sweden)

    S. Medić

    2016-10-01

    Full Text Available This paper examines the parameters of casting ZnAl4Cu3 alloy (volume, castability, density and occupancy of the mold in mold made additive technology. Molds made by additive technology are: cheaper in production of a small number of castings, geometrically more accurate and faster made. From obtained results of this paper it is clearly seen that printed mold must be protected with thermal coating because liquid adhesive of powder otherwise evaporates during casting and creates additional moisture in the mold, as it was noted.

  19. Temperature and Thermal Stress Distribution for Metal Mold in Squeeze Casting Process

    Institute of Scientific and Technical Information of China (English)

    K.H.Chang; G.C.Jang; C.H.Lee; S.H.Lee

    2008-01-01

    In the squeeze casting process, loaded high pressure (over approximately 100 MPa) and high temperature influence the thermo-mechanical behavior and performance of the used metal mold. Therefore, to safely maintain the metal molds, the thermo-mechanical characteristics (temperature and thermal stress) of metal mold in the squeeze casting must be investigated. In this paper, temperature and thermal stress distribution of steel mold in squeeze casting process were investigated by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis considering temperature-dependent thermo- physical and mechanical properties of the steel mold.

  20. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    Directory of Open Access Journals (Sweden)

    Daming XU

    2004-08-01

    Full Text Available Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section prcision castings.

  1. Effects of Process Parameters on Replication Accuracy of Microinjection Molded Cyclic Olefins Copolymers Parts

    Science.gov (United States)

    Lin, Hsuan-Liang; Chen, Chun-Sheng; Lee, Ruey-Tsung; Chen, Shia-Chung; Chien, Rean-Der; Jeng, Ming-Chang; Hwang, Jiun-Ren

    2013-04-01

    In this study, the effects of various processing parameters of microinjection molding on the replication accuracy of the micro featured fluidic platform used for DNA/RNA tests are investigated. LIGA-like processes were utilized to prepare a silicon-based SU-8 photoresist, followed by electroforming to make a Ni-Co-based stamp. A cyclic olefin copolymer (COC) was used as the injection molding material. The molding parameters associated with the replication accuracy of micro channel parts were investigated. It was found that for microinjection molded devices, the replication accuracies of the imprint width and depth increase with increasing of mold temperature, melt temperature, injection velocity, and packing pressure.

  2. An Impedance-Based Mold Sensor with on-Chip Optical Reference

    OpenAIRE

    Poornachandra Papireddy Vinayaka; Sander van den Driesche; Roland Blank; Muhammad Waseem Tahir; Mathias Frodl; Walter Lang; Michael J. Vellekoop

    2016-01-01

    A new miniaturized sensor system with an internal optical reference for the detection of mold growth is presented. The sensor chip comprises a reaction chamber provided with a culture medium that promotes the growth of mold species from mold spores. The mold detection is performed by measuring impedance changes with integrated electrodes fabricated inside the reaction chamber. The impedance change in the culture medium is caused by shifts in the pH (i.e., from 5.5 to 8) as the mold grows. In ...

  3. Investigation of micro-injection molding based on longitudinal ultrasonic vibration core.

    Science.gov (United States)

    Qiu, Zhongjun; Yang, Xue; Zheng, Hui; Gao, Shan; Fang, Fengzhou

    2015-10-01

    An ultrasound-assisted micro-injection molding method is proposed to improve the rheological behavior of the polymer melt radically, and a micro-injection molding system based on a longitudinal ultrasonic vibration core is developed and employed in the micro-injection molding process of Fresnel lenses. The verification experiments show that the filling mold area of the polymer melt is increased by 6.08% to 19.12%, and the symmetric deviation of the Fresnel lens is improved 15.62% on average. This method improved the filling performance and replication quality of the polymer melt in the injection molding process effectively.

  4. Uma análise de aspectos relacionados ao desenvolvimento e adoção de Enterprise Resources Planning livre de código aberto An analysis of aspects related to the development and adoption of free open source Enterprise Resources Planning

    Directory of Open Access Journals (Sweden)

    Rogério Atem de Carvalho

    2009-12-01

    Full Text Available Sistemas Integrados de Gestão ou Enterprise Resources Planning - ERP possibilitam o processamento das informações necessárias em uma empresa usando um único banco de dados. Muito tem se escrito sobre este tipo de software, abordando questões como o alto custo da aquisição de licenças, e a dependência de consultoria para a sua adaptação e implantação nas empresas. Atualmente vem crescendo o desenvolvimento e uso de ERP Livre de Código Aberto (FOS-ERP. Porém verifica-se que este tipo de sistema ainda não é suficientemente explorado, mesmo no meio acadêmico. Este artigo relata alguns trabalhos publicados sobre o assunto e levanta questões que devem ser tratadas por pesquisadores e demais interessados para adequar e viabilizar o uso desses sistemas conforme a realidade nacional. Assim, após uma introdução ao tema, são apresentadas algumas diferenças entre o FOS-ERP e seus equivalentes proprietários (Proprietary ERP ou P-ERP em termos de modelos de negócios, seleção, customização e evolução. Em seguida são elencados alguns desafios e oportunidades que o FOS-ERP pode oferecer a usuários, fornecedores, pesquisadores e colaboradores individuais. Concluindo, este artigo busca ampliar a discussão sobre FOS-ERP, destacando fatores tais como seu potencial de inovação tecnológica e estratégias de negócios.Enterprise Resources Planning (ERP enables the processing of information required in an enterprise, using a single database. Much has been written about this type of software, addressing issues such as the high cost of licenses acquisitions, and the dependence on consultants for its adaptation and implementation in companies. Currently the development and use of ERP Free Open Source (FOS-ERP has increased. However, this type of system is still not sufficiently explored, even in academia. This article analyses some papers on the subject, and raises questions that must be addressed by researchers and other stakeholders

  5. A eficácia do milnaciprano em pacientes ambulatoriais com transtorno depressivo maior não respondedores ao tratamento com ISRSs: um estudo aberto de 12 semanas Efficacy of milnacipran in outpatients experiencing major depression non respondent to SSRIs: a 12-week open study

    Directory of Open Access Journals (Sweden)

    Marcelo P. Fleck

    2010-01-01

    Full Text Available CONTEXTO: O objetivo deste estudo é avaliar a eficácia do milnaciprano em pacientes ambulatoriais com depressão maior grave que não respondem em tempo e em dosagem adequados à terapia com ISRSs. MÉTODOS: Um estudo aberto multicêntrico com a duração de 12 semanas foi elaborado para avaliar a eficácia do milnaciprano após falha em um experimento com ISRS. Remissão completa (HAMD-17 50%, CGI e avaliação da qualidade de vida (WHOQOL-Bref. RESULTADOS: O escore HAMD-17 médio da amostra foi de 27 (7,2. As taxas de remissão com o milnaciprano foram de 17,5%, e as de resposta, 61,3%. Na linha de base, 70,9% dos pacientes foram classificados como gravemente sintomáticos. Ao final do tratamento, 48,1% dos pacientes foram classificados como normais assintomáticos ou sintomáticos limítrofes e 20,2% eram moderadamente sintomáticos. Além disso, os quatro domínios do WHOQOL-Bref, um instrumento genérico de mensuração de qualidade de vida, apresentou diferenças clínicas e estatísticas: CONCLUSÃO: Nossos resultados sugerem que o milnaciprano é uma possível opção para pacientes que não respondem a ISRSs. Uma vez que não há evidências na literatura de um antidepressivo que seja a melhor opção quando um ISRS falha, o uso do milnaciprano deveria ser considerado em casos de pacientes com depressão severa.BACKGROUND: The objective of this study is to evaluate the efficacy of milnacipran in outpatients experiencing severe MDD non-respondent to adequate time and dosing of SSRI therapy. METHODS: A 12 week multi-centric study open study was designed to evaluate the efficacy of milnacipran after a SRRI trial failure. Complete remission (HAMD-17 50%, CGI and quality of life measure (WHOQOL-Bref. RESULTS: The mean HAMD-17 score of the sample was 27 (7.2. The remission rates for minalcipran were 17.5% and response 61.3%. At baseline, 70.9% of the patients were markedly or severely ill. At treatment end, 48.1% of the patients were normal

  6. Comparison between the 1% and 2% ibopamine provocative test in primary open-angle glaucoma patients: sensitivity, specificity and tolerability Comparação entre o teste de ibopamina a 1% e a 2% no glaucoma primário de ângulo aberto: sensibilidade, especificidade e tolerabilidade

    Directory of Open Access Journals (Sweden)

    Leopoldo Magacho

    2006-10-01

    Full Text Available PURPOSE: To compare intraocular pressure (IOP rise in normal individuals and primary open-angle glaucoma patients and the safety and efficacy of ibopamine eye drops in different concentrations as a provocative test for glaucoma. METHODS: Glaucoma patients underwent (same eye the ibopamine provocative test with two concentrations, 1% and 2%, in a random sequence at least 3 weeks apart, but not more than 3 months. The normal individuals were randomly submitted to one of the concentrations of ibopamine (1% and 2%. The test was considered positive if there was an IOP rise greater than 3 or 4 mmHg at 30 or 45 minutes to test which subset of the test has the best sensitivity (Se/specificity (Sp. RESULTS: There was no statistically significant difference in any of the IOP measurements, comparing 1% with 2% ibopamine. The IOP was significantly higher at 30 and 45 minutes with both concentrations (pOBJETIVO: Comparar a tolerabilidade e a eficácia do teste provocativo da ibopamina com diferentes concentrações em pacientes com glaucoma primário de ângulo aberto. MÉTODOS: Pacientes com glaucoma (mesmo olho foram aleatoriamente submetidos ao teste provocativo da ibopamina com as duas concentrações comercialmente disponíveis: 1% e 2% com pelo menos 3 semanas de intervalo, mas não superior a 3 meses. Os indivíduos normais foram randomizados a uma das concentrações utilizadas. O teste era considerado positivo se houvesse elevação da pressão intra-ocular (Pio superior a 3 ou 4 mmHg 30 ou 45 minutos após o início do teste para se estabelecer a melhor relação sensibilidade (Se/especificidade (Es do teste. RESULTADOS: Treze pacientes com glaucoma, 15 indivíduos normais com a ibopamina a 2% e 13 com a ibopamina a 1% foram incluídos. Não houve diferença estatisticamente significativa em qualquer uma das médias da Pio entre a ibopamina a 1% ou a 2%. A Pio foi significativamente maior aos 30 e 45 minutos com ambas as concentrações (p3 mm

  7. Effects of centrifugal and Coriolis forces on the mold-filling behavior of titanium melts in vertically rotating molds

    Institute of Scientific and Technical Information of China (English)

    Xu Daming; Jia Limin; Fu Hengzhi

    2008-01-01

    The vertical centrifugal-casting technique is widely used in the manufacture of various irregularly-shaped castings of advanced structural alloys with thin walls, complex shapes and/or large sizes. These castings are used in the increasing applications in aero-space/aviation industries, human teeth/bone repairs with near-net shaped components, etc. In a vertically rotating casting system, the mold-filling processes of alloy melts, coupled with solidification-heat transfer, may be much more complicated, because they are driven simultaneously by gravity, centrifugal and Codolis forces. In the present work, an N-S/VOF-equations-based model, solved using a SOLA-VOF algorithm, under a rotating coordinate system was applied to numerically investigate the impacts of centrifugal and Coriolis forces on metallic melt mold-filling processes in different vertical centrifugal-casting configurations with different mold-rotation rates using an authors' computer-codes system. The computational results show that the Coriolis force may cause remarkable variations in the flow patterns in the casting-part-cavities of a large horizontal-section area and directly connected to the sprue via a short ingate in a vertical centrifugal-casting process. A "turn-back" mold-filling technique, which only takes advantage of the centrifugal force in a transient rotating melt system, has been confirmed to be a rational centrifugal-casting process in order to achieve smooth and layer-by-layer casting-cavities-filling control. The simulated mold-filling processes of Ti-6Al-4V alloy melt, in a vertical centrifugal-casting system with horizontally-connected plate-casting cavities, show reasonable agreement with experimental results from the literature.

  8. Precision molding of advanced glass optics: innovative production technology for lens arrays and free form optics

    Science.gov (United States)

    Pongs, Guido; Bresseler, Bernd; Bergs, Thomas; Menke, Gert

    2012-10-01

    Today isothermal precision molding of imaging glass optics has become a widely applied and integrated production technology in the optical industry. Especially in consumer electronics (e.g. digital cameras, mobile phones, Blu-ray) a lot of optical systems contain rotationally symmetrical aspherical lenses produced by precision glass molding. But due to higher demands on complexity and miniaturization of optical elements the established process chain for precision glass molding is not sufficient enough. Wafer based molding processes for glass optics manufacturing become more and more interesting for mobile phone applications. Also cylindrical lens arrays can be used in high power laser systems. The usage of unsymmetrical free-form optics allows an increase of efficiency in optical laser systems. Aixtooling is working on different aspects in the fields of mold manufacturing technologies and molding processes for extremely high complex optical components. In terms of array molding technologies, Aixtooling has developed a manufacturing technology for the ultra-precision machining of carbide molds together with European partners. The development covers the machining of multi lens arrays as well as cylindrical lens arrays. The biggest challenge is the molding of complex free-form optics having no symmetrical axis. A comprehensive CAD/CAM data management along the entire process chain is essential to reach high accuracies on the molded lenses. Within a national funded project Aixtooling is working on a consistent data handling procedure in the process chain for precision molding of free-form optics.

  9. Análise das propriedades do PP injetado em molde-protótipo em Zamac-8 visando a obtenção de protótipos funcionais

    OpenAIRE

    Junkes, Vanderlei

    2015-01-01

    O uso de moldes-protótipo é uma opção para a obtenção de protótipos funcionais de peças de plástico injetadas. Estes protótipos devem possuir características mecânicas e físicas as mais próximas possíveis das peças finais obtidas em moldes de produção. A fim de diminuir o custo e o tempo de fabricação destes moldes, materiais alternativos, tais como o alumínio e ligas de zinco, podem ser empregados. Os diferentes níveis de condutividade térmica desses materiais resultam em diferentes taxas de...

  10. EXPERIMENTAL RESEARCH AND NUMERICAL SIMULATION OF MOLD TEMPERATURE FIELD IN CONTINUOUS CASTING OF STEEL

    Institute of Scientific and Technical Information of China (English)

    X.S. Zheng; M.H. Sha; J.Z. Jin

    2006-01-01

    Mold is the heart of the continuous casting machine. Heat transfer and solidification in a watercooled mold are the most important factors during the continuous casting of steel. For studying the temperature distribution of a mold wall, a simulated apparatus of mold was designed and experiments were performed by it. The measured results indicated that the mold wall temperature approaches the temperature of cooling-water. An equivalent thermal-conductivity coefficient was proposed and deduced on the basis of the conclusion of the experiments. This coefficient was applied to solve the heat transfer between the melt and cooling water, and to characterize the heat transfer capacity of the mold. By this equivalent thermal-conductivity coefficient, it is very easy and convenient to numerically simulate the solidification process of continuous casting. And the calculation results are in agreement with the experiments. The effects of casting speed and water flow rate on the mold temperature field were also discussed.

  11. Modeling and flow analysis of pure nylon polymer for injection molding process

    Science.gov (United States)

    Nuruzzaman, D. M.; Kusaseh, N.; Basri, S.; Oumer, A. N.; Hamedon, Z.

    2016-02-01

    In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured.

  12. EXPERIMENTAL MEASUREMENT OF MAGNETIC FIELD IN A NOVEL FLOW CONTROL OF MOLD

    Institute of Scientific and Technical Information of China (English)

    G.J. Xu; D.H. Li; J.C. He

    2002-01-01

    In order to know the distribution of magnetic field in a novel flow control of mold(NFC Mold) and to provide the experimental data for the electromagnetic structuredesign and the analysis of flow control in continuous casting mold, the magnetic fieldin a NFC Mold were measured by Tesla meter of Model CT-3. The method of vectorsynthesis was adopted in the measurement of magnetic fields. The results showed thatthe magnetic field in the NFC Mold was composed of two main magnetic areas thatwere symmetrical. Although there was leaking magnetic flux between the lower surfaceof the upper pole and the upper surface of the lower pole on the sides, it was restrainedby the main magnetic fields effectively. Therefore the NFC Mold was more preferablysatisfied to be used in controlling the molten steel flow in continuous casting mold.

  13. Analysis of the origin of periodic oscillatory flow in the continuous casting mold

    Science.gov (United States)

    Lee, Jun-young; Kim, Yong-tae; Yi, Kyung-woo

    2015-03-01

    It is very important to understand flow patterns within the continuous casting mold because they have a significant impact on product quality. Water model experiment and particle image velocimetry were conducted to identify the fluid flow pattern in the steel slab continuous casting mold. The fluid flow pattern in the mold is not steady but instead an oscillatory flow with a specific oscillation frequencies. Many studies have been reported about oscillatory flow within the mold. However, these studies do not provide a clear explanation of physical origin of oscillatory flow. We identified the physical origins of various specific oscillation frequencies, and confirmed through experimentation and simulation that each frequency is related to the cross flow and injection stream oscillation. Moreover, the degree of oscillation at each frequency appears differently depending on the location within the mold, and is shown to have a effect near the mold wall. These results provide a better understanding of complex oscillatory flow patterns within the mold.

  14. Fiber Reinforcement in Injection Molded Nylon 6/6 Spur Gears

    Science.gov (United States)

    Senthilvelan, S.; Gnanamoorthy, R.

    2006-07-01

    Injection molded polymer composite gears are being used in many power and or motion transmission applications. In order to widen the utilization of reinforced polymers for precision motion transmission and noise less applications, the accuracy of molded gears should be increased. Since the injection molded gear accuracy is significantly influenced by the material shrinkage behaviour, there is a need to understand the influence of fiber orientation and gate location on part shrinkage behaviour and hence the gear accuracy. Unreinforced and 20% short glass fiber reinforced Nylon 6/6 spur gears were injection molded in the laboratory and computer aided simulations of gear manufacturing was also carried out. Results of the mold flow simulation of gear manufacturing were correlated with the actual fiber orientation and measured major geometrical parameters of the molded gears. Actual orientation of the fibers near the tooth profile, weld line region and injection points of molded gears were observed using optical microscope and correlated with predicted fiber orientation.

  15. Increasing the life of molds for casting copper and its alloys

    Science.gov (United States)

    Smirnov, A. N.; Spiridonov, D. V.

    2010-12-01

    The work of the molds intended for casting copper and copper alloys in semicontinuous casters for producing flat billets is considered. It is shown that, to increase the resistance of mold plates, the inner space of the mold should have a taper shape toward the casting direction and take into account the shrinkage of the linear dimensions of the ingot during its motion in the mold. The taper shape increases the intensity and uniformity of heat removal due to close contact between the ingot and the mold inner surface. Testing of new design molds under industrial conditions demonstrates that their resistance increases by a factor of 4.0-4.5. The taper effect of the mold plates is much more pronounced in their narrow faces.

  16. Composite materials molding simulation for purpose of automotive industry

    Science.gov (United States)

    Grabowski, Ł.; Baier, A.; Majzner, M.; Sobek, M.

    2016-08-01

    Composite materials loom large increasingly important role in the overall industry. Composite material have a special role in the ever-evolving automotive industry. Every year the composite materials are used in a growing number of elements included in the cars construction. Development requires the search for ever new applications of composite materials in areas where previously were used only metal materials. Requirements for modern solutions, such as reducing the weight of vehicles, the required strength and vibration damping characteristics go hand in hand with the properties of modern composite materials. The designers faced the challenge of the use of modern composite materials in the construction of bodies of power steering systems in vehicles. The initial choice of method for producing composite bodies was the method of molding injection of composite material. Molding injection of polymeric materials is a widely known and used for many years, but the molding injection of composite materials is a relatively new issue, innovative, it is not very common and is characterized by different conditions, parameters and properties in relation to the classical method. Therefore, for the purpose of selecting the appropriate composite material for injection for the body of power steering system computer analysis using Siemens NX 10.0 environment, including Moldex 3d and EasyFill Advanced tool to simulate the injection of materials from the group of possible solutions were carried out. Analyses were carried out on a model of a modernized wheel case of power steering system. During analysis, input parameters, such as temperature, pressure injectors, temperature charts have been analysed. An important part of the analysis was to analyse the propagation of material inside the mold during injection, so that allowed to determine the shape formability and the existence of possible imperfections of shapes and locations air traps. A very important parameter received from

  17. Influence of mold and substrate material combinations on nanoimprint lithography process: MD simulation approach

    Science.gov (United States)

    Yang, Seunghwa; Yu, Suyoung; Cho, Maenghyo

    2014-05-01

    A molecular dynamics (MD) study was performed to examine the effect of mold-substrate material composition on the pattern transferring and defects of the resist polymer in a thermal Nano Imprint Lithography (NIL) process. As candidate materials, single crystalline nickel (Ni), silicon (Si) and silica (SiO2, α-quartz) for the rigid mold substrate, and amorphous poly-(methylmethacrylate) (PMMA) thin film for the resist were considered for common applications in NIL processes. Three different material compositions of Si mold-Ni substrate, Ni mold-Si substrate, and quartz mold-Ni substrate were considered. In accordance with a real NIL process, a sequence of indentation-relaxation-release processes was quasi-statically simulated using isothermal ensemble simulation on tri-layer molecular structures consisting of a mold, resist, and substrate. To correlate the deformed shape and delamination of PMMA resist from the substrate in indentation and release processes, non-bond interaction energy between a rigid mold and resist was calculated for each combination of mold and substrate materials. The Si mold-Ni substrate combination shows successful pattern transfer to the resist polymer even without an anti-sticking layer as a result of the desirable balance of surface free energy for mold and substrate materials. However, Ni mold-Si substrate combination shows a critical delamination of the resist in the release process due to strong van der Waals adhesion between the resist and Ni mold. Similarly, the quartz mold-Ni substrate combination shows the same delamination in pattern transfer, but the adhesion of the resist to the quartz mold is attributed to electrostatic interaction. In order to provide guidelines for material selection in imprint-like processes where surface adsorption and wetting characteristics are critical design parameters, a simple PMMA-rigid plate model is proposed, with which consistent surface interaction characteristics in the full model NIL process

  18. Determinantes da Qualidade das Práticas de Governança Corporativa das Empresas Brasileiras de Capital Aberto que Possuem Investimentos PúblicosQuality Determinants of Corporate Governance Practices of Brazilian Companies of Traded that Have Public InvestmentDeterminantes de la Calidad de las Prácticas de Gestión Corporativa de las Empresas Brasileñas de Capital Abierto con Inversiones Públicas

    Directory of Open Access Journals (Sweden)

    ALMEIDA, Moisés Araújo

    2010-12-01

    Full Text Available RESUMOA adoção das boas práticas de governança corporativa abre espaço para uma gestão mais transparente, diminuindo a assimetria de informações e o conflito de agência. O objetivo do artigo é investigar os determinantes da qualidade das práticas de governança corporativa das empresas brasileiras de capital aberto que possuem investimento público. A amostra da pesquisa é formada por 35 empresas públicas brasileiras de capital aberto para o ano de 2005 e por 34 empresas para o ano de 2006, com informações públicas disponibilizadas pela CVM. Utilizaram-se técnicas econométricas de regressão linear múltipla, com aplicação do método dos mínimos quadrados ordinários. Os resultados mostraram que a maior parte das empresas analisadas apresentam um nível de governança acima da média da amostra. Também foi evidenciado que maior concentração de ações de controle nas mãos de um único acionista influencia positivamente o indicador da qualidade das práticas de governança corporativa, e que alavancagem, tangibilidade, crescimento e idade impactam negativamente sobre as práticas de governança das empresas analisadas.ABSTRACTThe adoption of good practices of corporate governance allows transparent management, diminishing the asymmetry of information and the agency conflict. This article investigates the determinants of the corporate governance quality on Brazilian companies with public investment. The sample of the research was constituted by 35 firms for the year 2005 and 34 firms for the year 2006, with public information available on CVM database. It was used econometric techniques of multiple linear regression with application of the ordinary least squares. The results show that the major part of the analyzed companies presents levels of governance above the average. Also, it is evidenced that the greater ownership concentration in the hands of a single shareholder influences positively the corporate governance index

  19. Route 20, Autobahn 7, and Slime Mold: Approximating the Longest Roads in USA and Germany With Slime Mold on 3-D Terrains.

    Science.gov (United States)

    Adamatzky, Andrew I

    2014-01-01

    A cellular slime mould Physarum polycephalum is a monstrously large single cell visible by an unaided eye. The slime mold explores space in parallel, is guided by gradients of chemoattractants, and propagates toward sources of nutrients along nearly shortest paths. The slime mold is a living prototype of amorphous biological computers and robotic devices capable of solving a range of tasks of graph optimization and computational geometry. When presented with a distribution of nutrients, the slime mold spans the sources of nutrients with a network of protoplasmic tubes. This protoplasmic network matches a network of major transport routes of a country when configuration of major urban areas is represented by nutrients. A transport route connecting two cities should ideally be a shortest path, and this is usually the case in computer simulations and laboratory experiments with flat substrates. What searching strategies does the slime mold adopt when exploring 3-D terrains? How are optimal and transport routes approximated by protoplasmic tubes? Do the routes built by the slime mold on 3-D terrain match real-world transport routes? To answer these questions, we conducted pioneer laboratory experiments with Nylon terrains of USA and Germany. We used the slime mold to approximate route 20, the longest road in USA, and autobahn 7, the longest national motorway in Europe. We found that slime mold builds longer transport routes on 3-D terrains, compared to flat substrates yet sufficiently approximates man-made transport routes studied. We demonstrate that nutrients placed in destination sites affect performance of slime mold, and show how the mold navigates around elevations. In cellular automaton models of the slime mold, we have shown variability of the protoplasmic routes might depends on physiological states of the slime mold. Results presented will contribute toward development of novel algorithms for sensorial fusion, information processing, and decision making, and

  20. Seasonal dynamics of a drosophilid (Diptera assemblage and its potencial as bioindicator in open environments Dinâmica sazonal de uma assembléia de drosofilídeos (Diptera e seu potencial como bioindicadora em ambientes abertos

    Directory of Open Access Journals (Sweden)

    Luís Bizzo

    2010-09-01

    Full Text Available Drosophila Fallen, 1823 (Diptera, Drosophilidae is for long a well-established model organism for genetics and evolutionary research. The ecology of these flies, however, has only recently been better studied. Recent papers show that Drosophila assemblies can be used as bioindicators of forested environment degradation. In this work the bioindicator potential of drosophilids was evaluated in a naturally opened environment, a coastal strand-forest (restinga. Data from nine consecutive seasonal collections revealed strong temporal fluctuation pattern of the majority of Drosophila species groups. Drosophila willistoni group was more abundant at autumns, whereas D. cardini and D. tripunctata groups were, respectively, expressive at winters and springs, and D. repleta group at both seasons. The exotic species D. simulans Sturtevant, 1919 (from D. melanogaster group and Zaprionus indianus Gupta, 1970 were most abundant at summers. Overall, the assemblage structure did not show the same characteristics of forested or urban environments, but was similar to the forests at winters and to cities at summers. This raises the question that this locality may already been under urbanization impact. Also, this can be interpreted as an easily invaded site for exotic species, what might lead to biotic homogenization and therefore can put in check the usage of drosophilid assemblages as bioindicators at open environments.Drosophila Fallen, 1823 (Diptera, Drosophilidae é, há muito tempo, um organismo modelo em pesquisas de genética e evolução. A ecologia destas moscas, no entanto, apenas recentemente foi melhor estudada. Trabalhos recentes apontam que as assembléias de Drosophila podem ser utilizadas como bioindicadoras de degradação de ambientes florestais. Neste trabalho, foi avaliado o potencial bioindicador dos drosofilídeos em um ambiente de restinga, naturalmente aberto. Dados de nove coletas sazonais consecutivas revelaram um forte padrão de flutua

  1. Grau de exposição a praguicidas organoclorados em moradores de aterro a céu aberto Levels of exposure to organochlorine pesticides in open-air dump dwellers

    Directory of Open Access Journals (Sweden)

    Eladio Santos Filho

    2003-08-01

    Full Text Available OBJETIVO: Estimar o grau de exposição interna aos praguicidas organoclorados (POP dos moradores de um atêrro a céu aberto. MÉTODOS: Estudo observacional, de aferição simultânea e controlado, cujo fator de estudo foi residir em área contaminada por POP e o efeito foi a concentração sanguínea dessas substâncias. A população de estudo foi de 238 pessoas residentes em um aterro a céu aberto (Pilões, no município de Cubatão, SP; e a população de controle ficou dimensionada em 258 pessoas, também residentes no mesmo município (Cota 200. Foram analisados os praguicidas HCB, p-p'DDT, p-p'DDE, p-p'DDD, o-p'DDT, a HCH; b HCH; g HCH; Aldrin; Dieldrin; Endrin; Heptaclor; Heptaclor-epoxi e Mirex. RESULTADOS: Os teores médios sangüíneos de HCB em Pilões foram de 4,66 µg/L, 155 vezes maior que a média na Cota 200 (0,03 µg/L. Em Pilões, os teores médios de DDT total foram de 3,71 µg/L, duas vezes maior do que na Cota 200 (1,85 µg/L e o HCH total apresentou concentrações sangüíneas seis vezes maiores em Pilões, 0,84 µg/L, contra 0,13 µg/L. CONCLUSÕES: Evidenciou-se associação positiva entre residir em Pilões e apresentar teores sangüíneos de POP, com risco muitas vezes maior quando comparado a localidades sem a presença desses contaminantes.OBJECTIVE: To estimate the degree of internal exposure to organochlorine pesticides (persistent organic pollutants, POP among inhabitants of an open-air dump. METHODS: This was an observational study with simultaneous measurement and control, in which the criterion for subjects was that they dwelled in an area contaminated by POP and the effect of such contamination was the concentration of such substances into the blood. The study population consisted of 238 people living on an open-air dump in Pilões, in the municipality of Cubatão, SP, Brazil, and the control population was formed by 258 people, also resident in that municipality, in the Cota 200 district. The following

  2. Fluvoxamina no transtorno depressivo maior: um estudo multicêntrico aberto Fluvoxamine in the treatment of major depressive disorder: an open multicentric study

    Directory of Open Access Journals (Sweden)

    José Alberto Del Porto

    2007-01-01

    Full Text Available OBJETIVO: Este trabalho estudou a eficácia e a tolerabilidade da fluvoxamina no tratamento, de forma aberta, sem comparação com placebo ou outros agentes, por 6 semanas, de pacientes com o diagnóstico de transtorno depressivo maior (TDM. Constitui-se em objetivo secundário do estudo avaliar os efeitos da fluvoxamina sobre o sono dos pacientes. MÉTODOS: Foram incluídos 104 pacientes, maiores de 18 anos, com o diagnóstico de TDM, de acordo com os critérios do Manual Diagnóstico e Estatístico de Transtornos Mentais, 4ª edição (DSM-IV, e com escores, na Escala de Hamilton para Depressão, versão de 17 itens (HAM-D 17, de 17 pontos ou mais. Avaliou-se a eficácia da fluvoxamina por meio das Escalas HAM-D 17 e da CGI (Impressão Clínica Global. A análise dos itens 4, 5 e 6 da HAM-D 17 foi utilizada para a avaliação do sono dos pacientes. Avaliaram-se a segurança e a tolerabilidade da fluvoxamina ao longo das 6 semanas, registrando-se quaisquer eventos adversos. A fluvoxamina foi inicialmente ministrada em doses de 50 ou 100 mg/dia, podendo haver aumentos progressivos até 300 mg/dia. RESULTADOS: Dos 104 pacientes incluídos, 81 (78% concluíram o estudo. Obtiveram resposta favorável (diminuição de 50% ou mais na HAM-D 17 69% dos pacientes, e a taxa de remissão (HAM-D 17 OBJECTIVE: This research studied the efficacy and tolerability of fluvoxamine in the treatment of major depressive disorder (MDD, during 6 weeks, in an open trial, without placebo or active comparator. A secondary objective was the evaluation of the effects of fluvoxamine on the sleep of the pacients. METHODS: 104 patients were inicially included, with the diagnosis of MDD in accordance to the criteria of the Diagnostic and Statistical Manual for Mental Disorders, 4th edition (DSM-IV. Patients should have scores > 17 in the Hamilton Depression Scale for Depression 17 itens (HAM-D 17. The efficacy of fluvoxamine was studied through the HAM-D 17 and CGI (Clinical

  3. Fabrication of Complex Optical Components From Mold Design to Product

    CERN Document Server

    Riemer, Oltmann; Gläbe, Ralf

    2013-01-01

    High quality optical components for consumer products made of glass and plastic are mostly fabricated by replication. This highly developed production technology requires several consecutive, well-matched processing steps called a "process chain" covering all steps from mold design, advanced machining and coating of molds, up to the actual replication and final precision measurement of the quality of the optical components. Current market demands for leading edge optical applications require high precision and cost effective parts in large volumes. For meeting these demands it is necessary to develop high quality process chains and moreover, to crosslink all demands and interdependencies within these process chains. The Transregional Collaborative Research Center "Process chains for the replication of complex optical elements" at Bremen, Aachen and Stillwater worked extensively and thoroughly in this field from 2001 to 2012. This volume will present the latest scientific results for the complete process chain...

  4. Preparation of Ti-Mo getters by injection molding

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhenmei; WEI Xiuying; XIONG Yuhua; MAO Changhui

    2009-01-01

    Ti-Mo getters have been fabricated via metal injection molding (MIM) using three kinds of Ti powders with different mean particle sizes of 46 μm, 35 μm and 26 μm, respectively. The surface morphology, porosity, and hydrogen sorption properties of Ti-Mo getters formed by MIM using paraffin wax as a principal binder constituent were examined. It has been proven that the powder injection molding is a viable forming technique for porous Ti-Mo getter. The particle size of Ti powders and the powder loading influence the porosity of getters, and this affects the sorption capacity of Ti-Mo getters. Ti-Mo getters produced with the Ti powders possessing a mean particle size of 35 μm using a powder loading of 40 vol.% have a high porosity, resulting in a good sorption capacity.

  5. Characteristics of shell thickness in a slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)

    Di-feng Wu; Shu-sen Cheng; Zi-jian Cheng

    2009-01-01

    The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold.A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid (VOF) model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions.The results show that the jet acts a stronger impingement on the shell of narrow face,which causes a zero-increase of shell thickness in a certain range near the impingement point.The thinnest shell on the slab cross-section locates primarily in the center of the narrow face,and secondly near the comer of the wide face.Nozzle optimization can obviously increase the shell thickness and make it more uniform.

  6. FPGA-Based Multiprocessor System for Injection Molding Control

    Directory of Open Access Journals (Sweden)

    Roque A. Osornio-Rios

    2012-10-01

    Full Text Available The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected.

  7. Injection molded polymeric hard X-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik; Simons, Hugh; Jakobsen, Anders Clemen;

    2015-01-01

    A novel and economical approach for fabricating compound refractive lenses for the purpose of focusing hard X-rays is described. A silicon master was manufactured by UV-lithography and deep reactive ion etching (DRIE). Sacrificial structures were utilized, which enabled accurate control of the et......A novel and economical approach for fabricating compound refractive lenses for the purpose of focusing hard X-rays is described. A silicon master was manufactured by UV-lithography and deep reactive ion etching (DRIE). Sacrificial structures were utilized, which enabled accurate control...... of the etching profile and were removed after DRIE. By electroplating, an inverse nickel sample was obtained, which was used as a mold insert in a commercial polymer injection molding machine. A prototype lens made of polyethylene with a focal length of 350 mm was tested using synchrotron radiation at photon...

  8. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    Energy Technology Data Exchange (ETDEWEB)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  9. Pressureless sintering behavior of injection molded alumina ceramics

    Directory of Open Access Journals (Sweden)

    Liu W.

    2014-01-01

    Full Text Available The pressureless sintering behaviors of two widely used submicron alumina (MgOdoped and undoped with different solid loadings produced by injection molding have been studied systematically. Regardless of the sinterability of different powders depending on their inherent properties, solid loading plays a critical role on the sintering behavior of injection molded alumina, which greatly determines the densification and grain size, and leads to its full densification at low temperatures. As compared to the MgO-doped alumina powder, the undoped specimens exhibit a higher sinterability for its smaller particle size and larger surface area. While full densification could be achieved for MgO-doped powders with only a lower solid loading, due to the fact that MgO addition can reduce the detrimental effect of the large pore space on the pore-boundary separation.

  10. Surviving freezing in plant tissues by oomycetous snow molds.

    Science.gov (United States)

    Murakami, Ryo; Yajima, Yuka; Kida, Ken-ichi; Tokura, Katsuyuki; Tojo, Motoaki; Hoshino, Tamotsu

    2015-04-01

    Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis.

  11. Bearing Behavior of Drilled and Molded-in Holes

    Science.gov (United States)

    Durante, Massimo; Langella, Antonio

    2009-10-01

    Glass/epoxy composites were manufactured using RIFT (Resin Infusion under Flexible Tool), a closed mould process capable of obtaining large and complex forms, by impregnating, under a vacuum, a dry preform placed on a flat rigid mould. At certain points of these composite laminates, molded-in holes were made in the dry perform before the resin infusion phase, using two different methods: displacing or cutting the yarn of the fibers. After the resin treatment, other holes were made in the same laminates by drilling. Single-point pin-loaded specimens, cut from laminates, were tested for different values of specimen width-to-hole diameter ratio (W/D) and edge distance-to-hole diameter ratio. In the results of the experiment, the specimens with molded in holes made by displacing the fiber yarn showed higher bearing strength values.

  12. Numerical Simulation and Water Analog of Mold Filling Processes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper demonstrates the potential of a computer code, developed by the authors, in shaping gating systems by modeling the fluid flow phenomena through a complex gating system during mold filling. A plate casting with dimension 200 mm×200 mm×50 mm was chosen as the verifying problem. Water analog studies were carried out on this casting. The comparison indicates that computer simulation could be a powerful tool in shaping gating systems.

  13. Tackification of textile preforms for resin transfer molding

    Institute of Scientific and Technical Information of China (English)

    Wuyunqiqige; YI; Xiao-su

    2005-01-01

    Tackified textile fiber preforms are used widely in resin transfer molding (RTM) to produce aerospace-grade composite parts. In the present study, a new tackifier was developed to improve RTM laminate performance. The influence of tackifier concentration on spring back, thermal properties and mechanical performance was studied . It has showed that the new tackifier was compatible with the matrix resin and improved the textile handling ability; the ILSS was slightly increased without decreasing of thermal properties, modulus and flexural strength.

  14. Presurgical nasoalveolar molding in unilateral cleft lip and palate

    Directory of Open Access Journals (Sweden)

    Rahul J Hegde

    2015-01-01

    Full Text Available Unilateral cleft lip and palate (UCLP patients have an esthetic and functional compromise of the middle third of the face and nasal structures. To improve the esthetic result of lip repair, the concept of presurgical nasoalveolar molding (PNAM was brought into conception. PNAM is an easy and passive method of bringing the alveolus and lips together by redirecting the forces of natural growth. This case report documents a 2-year follow-up of PNAM in UCLP.

  15. ''Heat Transfer at the Mold-Metal Interface in Permanent Mold Casting of Aluminum Alloys'' Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Professor R. D. Pehlke, Principal Investigator, Dr. John M. Cookson, Dr. Shouwei Hao, Dr. Prasad Krishna, Kevin T. Bilkey

    2001-12-14

    This project on heat transfer coefficients in metal permanent mold casting has been conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigation of squeeze casting at CMI-Tech Center (Now Hayes-Lemmerz Technical Center) and the experimental investigation of low pressure permanent mold casting at Amcast Automotive.

  16. Occurrence of Foodborne Pathogens and Molds in Turkish Foods

    Directory of Open Access Journals (Sweden)

    Sebnem Ozturkogu-Budak

    2016-07-01

    Full Text Available A survey of the occurrence of food pathogens like Salmonella, Listeria, Escherichia, Clostridium, Bacillus and Staphylococcus analyses were performed on 301 food samples from 8 different food categories such as dry legumes, milk products, meat products, fish, frozen foods, deserts, nuts and vegetables and fruits. Yeast and mold analyses were also performed on 364 food products from 9 main food categories such as dry legumes, milk products, meat products, seasonings, deserts, nuts, bee products, bakery products and dried fruits produced in Turkey. S. aureus and Salmonella were the most prevalent (1.33% of the six isolated pathogens. The species Cl. perfringens, L. monocytogenes and B. cereus were detected with the ratios of 1.00%, 0.66% and 0.66%, respectively. Total yeast and molds occurrence were 1.65% and 9.06%, respectively. Pathogens were detected in cream cheese, spinach, strawberry and cod fish most prevalently, whereas dried fig, chilli pepper, hazelnut and bakery products were determined as foods prone to the growth of molds. The results of this study suggest that faecal contamination of water needs to be prevented, and the production and storage conditions of food materials should be improved. These findings have implications for the use of these surveillance data in developing evidence-based food policy.

  17. Fabrication of Composite Material Using Gettou Fiber by Injection Molding

    Science.gov (United States)

    Setsuda, Roy; Fukumoto, Isao; Kanda, Yasuyuki

    This study investigated the mechanical properties of composite using gettou (shell ginger) fiber as reinforcement fabricated from injection molding. Gettou fiber is a natural fiber made from gettou, a subtropical plant that is largely abundant in Okinawa, Japan. We used the stem part of gettou plant and made the gettou fiber by crushing the stem. The composite using gettou fiber contributed to low shrinkage ratio, high bending strength and high flexural modulus. The mechanical strength of composite using long gettou fiber showed higher value than composite using short gettou fiber. Next, because gettou is particularly known for its anti-mold characteristic, we investigated the characteristic in gettou plastic composite. The composite was tested against two molds: aspergillius niger and penicillium funiculosum. The 60% gettou fiber plastic composite was found to satisfy the JISZ2801 criterion. Finally, in order to predict the flexural modulus of composite using gettou fiber by Halpin-Tsai equation, the tensile elastic modulus of single gettou fiber was measured. The tendency of the experimental results of composite using gettou fiber was in good agreement with Halpin-Tsai equation.

  18. Influence of the Mold Current on the Electroslag Remelting Process

    Science.gov (United States)

    Hugo, Mathilde; Dussoubs, Bernard; Jardy, Alain; Escaffre, Jessica; Poisson, Henri

    2016-08-01

    The electroslag remelting process is widely used to produce high value-added alloys. The use of numerical simulation has proven to be a valuable way to improve its understanding. In collaboration with Aubert & Duval, the Institute Jean Lamour has developed a numerical transient model of the process. The consumable electrode is remelted within a mold assumed to be electrically insulated by the solidified slag skin. However, this assumption has been challenged by some recent studies: the solidified slag skin may actually allow a part of the melting current to reach the mold. In this paper, the evolution of our model, in order to take into account this possibility, is presented and discussed. Numerical results are compared with experimental data, while several sensitivity studies show the influence of some slag properties and operating parameters on the quality of the ingot. Even, a weakly conductive solidified slag skin at the inner surface of the mold may be responsible for a non-negligible amount of current circulating between the slag and crucible, which in turn modifies the fluid flow and heat transfer in the slag and ingot liquid pool. The fraction of current concerned depends mainly on the electrical conductivities of both the liquid and solidified slag.

  19. Modeling injection molding of net-shape active ceramic components.

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Tomas (Gram Inc.); Cote, Raymond O.; Grillet, Anne Mary; Yang, Pin; Hopkins, Matthew Morgan; Noble, David R.; Notz, Patrick K.; Rao, Rekha Ranjana; Halbleib, Laura L.; Castaneda, Jaime N.; Burns, George Robert; Mondy, Lisa Ann; Brooks, Carlton, F.

    2006-11-01

    To reduce costs and hazardous wastes associated with the production of lead-based active ceramic components, an injection molding process is being investigated to replace the current machining process. Here, lead zirconate titanate (PZT) ceramic particles are suspended in a thermoplastic resin and are injected into a mold and allowed to cool. The part is then bisque fired and sintered to complete the densification process. To help design this new process we use a finite element model to describe the injection molding of the ceramic paste. Flow solutions are obtained using a coupled, finite-element based, Newton-Raphson numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. Thermal, rheological, and wetting properties of the PZT paste are measured for use as input to the model. The viscosity of the PZT is highly dependent both on temperature and shear rate. One challenge in modeling the injection process is coming up with appropriate constitutive equations that capture relevant phenomenology without being too computationally complex. For this reason we model the material as a Carreau fluid and a WLF temperature dependence. Two-dimensional (2D) modeling is performed to explore the effects of the shear in isothermal conditions. Results indicate that very low viscosity regions exist near walls and that these results look similar in terms of meniscus shape and fill times to a simple Newtonian constitutive equation at the shear-thinned viscosity for the paste. These results allow us to pick a representative viscosity to use in fully three-dimensional (3D) simulation, which because of numerical complexities are restricted to using a Newtonian constitutive equation. Further 2D modeling at nonisothermal conditions shows that the choice of

  20. Drag material change in hot runner injection molding

    Institute of Scientific and Technical Information of China (English)

    蒋炳炎; 黄伯云

    2001-01-01

    Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time-costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi-injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.