WorldWideScience

Sample records for cu-ni-sn para fins

  1. Studies of the development and characterization of the Cu-Ni-Pt and Cu-Ni-Sn alloys for electro-electronic uses; Estudos do desenvolvimento e caracterizacao das ligas Cu-Ni-Pt e Cu-Ni-Sn para fins eletro-eletronicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis Carlos Elias da

    2006-07-01

    The Cu and its alloys have different applications in the owed modern society the excellent electric properties, thermal conductivity, resistance to the corrosion and other properties. These applications can be in valves, pipes, pots for absorption of solar energy, radiators for automobiles, current driver, electronic driver, thermostats elements and structural parts of nuclear reactors, as, for example, reels for field toroidal for a reactor of nuclear coalition. The alloys used in nuclear reactors, we can highlight Cu-Be, Cu-Sn and Cu-Pt. Ni and Co frequently are added to the Cu alloys so that the solubility is moved for temperatures more elevated with relationship to the binary systems of Cu-Sn and Cu-Pt. The addition of Ni-Pt or Ni-Sn to the Cu in the same or inferior percentages to 1,5% plus thermomechanical treatments changes the properties of the copper. We studied the electric conductivity and hardness Vickers of the Cu-Ni-Pt and Cu-Ni-Sn and compared with the electrolytic Cu. In the proposed flowcharts, breaking of the obtaining of the ingot, we proceeded with thermo mechanical treatments. (author)

  2. Incorporation of trace elements in Portland cement clinker: Thresholds limits for Cu, Ni, Sn or Zn

    International Nuclear Information System (INIS)

    Gineys, N.; Aouad, G.; Sorrentino, F.; Damidot, D.

    2011-01-01

    This paper aims at defining precisely, the threshold limits for several trace elements (Cu, Ni, Sn or Zn) which correspond to the maximum amount that could be incorporated into a standard clinker whilst reaching the limit of solid solution of its four major phases (C 3 S, C 2 S, C 3 A and C 4 AF). These threshold limits were investigated through laboratory synthesised clinkers that were mainly studied by X-ray Diffraction and Scanning Electron Microscopy. The reference clinker was close to a typical Portland clinker (65% C 3 S, 18% C 2 S, 8% C 3 A and 8% C 4 AF). The threshold limits for Cu, Ni, Zn and Sn are quite high with respect to the current contents in clinker and were respectively equal to 0.35, 0.5, 0.7 and 1 wt.%. It appeared that beyond the defined threshold limits, trace elements had different behaviours. Ni was associated with Mg as a magnesium nickel oxide (MgNiO 2 ) and Sn reacted with lime to form a calcium stannate (Ca 2 SnO 4 ). Cu changed the crystallisation process and affected therefore the formation of C 3 S. Indeed a high content of Cu in clinker led to the decomposition of C 3 S into C 2 S and of free lime. Zn, in turn, affected the formation of C 3 A. Ca 6 Zn 3 Al 4 O 15 was formed whilst a tremendous reduction of C 3 A content was identified. The reactivity of cements made with the clinkers at the threshold limits was followed by calorimetry and compressive strength measurements on cement paste. The results revealed that the doped cements were at least as reactive as the reference cement.

  3. EFFECTS OF TIN ON HARDNESS, WEAR RATE AND COEFFICIENT OF FRICTION OF CAST CU-NI-SN ALLOYS

    Directory of Open Access Journals (Sweden)

    S. ILANGOVAN

    2013-02-01

    Full Text Available An investigation was carried out to understand the effects of Sn on hardness, wear rate and the coefficient of friction of spinodal Cu-Ni-Sn alloys. Alloys of appropriate compositions were melted in a crucible furnace under argon atmosphere and cast into sand moulds. Solution heat treated and aged specimens were tested for hardness, wear rate and the coefficient of friction. It was found that the hardness increases when the Sn content increases from 4% to 8% in the solution heat treated conditions. The peak aging time is found to decrease with an increase in the Sn content. Further, the coefficient of friction is independent of hardness whereas the wear rate decreases linearly with hardness irrespective of Sn content.

  4. Studies of the development and characterization of the Cu-Ni-Pt and Cu-Ni-Sn alloys for electro-electronic uses

    International Nuclear Information System (INIS)

    Silva, Luis Carlos Elias da

    2006-01-01

    The Cu and its alloys have different applications in the owed modern society the excellent electric properties, thermal conductivity, resistance to the corrosion and other properties. These applications can be in valves, pipes, pots for absorption of solar energy, radiators for automobiles, current driver, electronic driver, thermostats elements and structural parts of nuclear reactors, as, for example, reels for field toroidal for a reactor of nuclear coalition. The alloys used in nuclear reactors, we can highlight Cu-Be, Cu-Sn and Cu-Pt. Ni and Co frequently are added to the Cu alloys so that the solubility is moved for temperatures more elevated with relationship to the binary systems of Cu-Sn and Cu-Pt. The addition of Ni-Pt or Ni-Sn to the Cu in the same or inferior percentages to 1,5% plus thermomechanical treatments changes the properties of the copper. We studied the electric conductivity and hardness Vickers of the Cu-Ni-Pt and Cu-Ni-Sn and compared with the electrolytic Cu. In the proposed flowcharts, breaking of the obtaining of the ingot, we proceeded with thermo mechanical treatments. (author)

  5. Plan de Mercadeo para una “FinTech”.

    OpenAIRE

    Escalante Lee, Maria Alejandra

    2016-01-01

    Las empresas deben contar con una misión clara, estableciendo los objetivos de apoyo, diseñando una cartera de negocio sólida y coordinar sus estrategias a futuro, con el fin de cumplir las metas propuestas para entregar e intercambiar ofertas que tienen valor para los consumidores, clientes, socios y la sociedad en general. El presente trabajo de grado tiene como objetivo proponer un plan de mercadeo para la empresa Comyno una FinTech ubicada en Frankfurt am Main, en Alemania. Este tiene ...

  6. Estrabismo após toxina botulínica para fins estéticos

    Directory of Open Access Journals (Sweden)

    Marta Halfeld Ferrari Alves Lacordia

    2011-06-01

    Full Text Available RESUMO Nas últimas décadas, a toxina botulínica tem sido aplicada para fins terapêuticos em inúmeras afecções. A toxina do tipo A foi aprovada primeiramente em 1989 para o uso em estrabismo, blefaroespasmo e espasmo hemifacial de pacientes maiores que 12 anos de idade. A observação de que pacientes tratados de blefaroespasmo com toxina botulínica apresentavam um efeito adicional de diminuição das rugas de expressão inspirou estudos sobre a aplicação cosmética da toxina. Recentemente, a toxina botulínica do tipo A foi aprovada para fins estéticos. Este trabalho relata um caso de ocorrência de estrabismo após aplicação de toxina botulínica na face para fins estéticos.

  7. Meios e fins do desenvolvimento para Celso Furtado

    Directory of Open Access Journals (Sweden)

    Fabio Antonio de Campos

    2014-10-01

    Full Text Available O objetivo desse artigo é expor o conceito de desenvolvimento para Celso Furtado. Para tanto, nos interessa apresentar o desenvolvimento nacional como um fim em sua abordagem sobre a formação social brasileira Para atingir tal estágio, os meios para o autor seriam assegurados por um típico desenvolvimento capitalista. Dentro dessa problemática, mostraremos também o alcance e os limites dessa concepção para o caráter dependente e subdesenvolvido do capitalismo brasileiro.

  8. POTENCIAL FARMACOINDUSTRIAL DE Trichoderma harzianum PARA FINS FARMACOTERAPÊUTICOS

    Directory of Open Access Journals (Sweden)

    Luís Fernando Albarello Gellen

    2014-12-01

    Full Text Available Linhagens de Trichoderma estão bem difundidas nos processos de controle de fitopatógenos, além disto, para promoção do desenvolvimento e crescimento das culturas onde são inoculados, estes benefícios dão-se pela gama de processos desempenhados por este organismo, os processos são classificados em parasitismo, antibiose e competição, além de secretarem produtos enzimáticos com ações degradantes, compostos voláteis e antimicrobianos. Por meio de testes de produção enzimática, confronto em placa, metabólitos voláteis e sensibilização do agente, os isolados de Trichoderma harzianum mostraram-se como um potente produtor de substâncias antimicrobianas e antifúngicas perante Sthaphylococcus aureus, Streptococcus pyogenes, E. coli, Pseudomonas aeruginosa, E. faecalis e Rhodotorula sp., Candida albicans, Candida parapsilosis e Candida lusitaniae. Palavras-chave: antimicrobianos, antifúngicas, metabólitos, sensibilização. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n4p91-96

  9. UTILIZAÇÃO DO CUSTEIO POR ABSORÇÃO PARA FINS GERENCIAIS

    Directory of Open Access Journals (Sweden)

    César Augusto Tibúrcio Silva

    2009-08-01

    Full Text Available O urso grizzly gasta o outono a caçar e comer marmotas (McGee, 294. Para tanto, ele move grandes e profundas pedras. Considerando em termos globais, este trabalho do urso, quando comparado com o seu tamanho e o da marmota, leva à conclusão de que o urso desperdiça tempo e energia. Como o inverno é geralmente longo e rigoroso, esta dedução pode ser precipitada. O urso talvez esteja praticando esporte, divertindo-se ou exercitando-se ou talvez variando sua dieta. Ou ainda tudo isto em conjun-to. Provavelmente, a energia obtida em decorrência da ingestão da marmota seja superior aos custos da caça. O presente texto revela como o custeio por absorção pode ser utilizado para fins gerenciais. Apresenta, inicialmente, discus-são acerca da não utilização do custeio por absorção com a referida finalidade, em razão de promover distorções nas decisões devido à arbitrariedade dos rateios e de incentivar a superprodu-ção, aspecto enfatizado pela bibliografia da área de contabilidade gerencial. Por fim, demonstra que tal sistema de custeio pode ser um meio de implantação de certas estratégias empresariais e um substituto para mensuração das denominadas externalidades. (Custeio por Absorção – Contabilidade Gerencial

  10. Casas estudio: alternativa pedagógica para el proyecto de fin de carrera

    Directory of Open Access Journals (Sweden)

    Edison Henao Carvajal

    2011-12-01

    Full Text Available Este artículo da cuenta del proceso de elaboración del trabajo de grado de algunos de los estudiantes inscritos en la Línea de Profundización en Proyectos Arquitectónicos, del programa curricular de Arquitectura, de la sede Manizales de la Universidad Nacional de Colombia, durante los semestres segundo del 2009 y primero del 2010. El propósito de la experiencia, coordinada por los autores del artículo, consistió en poner a prueba un método de enseñanza-aprendizaje para el taller de proyectos de fin de carrera, en el marco de una concepción pedagógica basada en la solución de problemas de forma, a partir del reconocimiento y de la asimilación de las soluciones universales presentes en las obras de los grandes maestros de la arquitectura. En contravía de la metodología de concepción arquitectónica contemporánea, basada en “la realización de las ideas del autor”, el taller se centró en recuperar las maneras de operar de la modernidad arquitectónica, en las que tiene mayor importancia la búsqueda de una implantación correcta de la obra, la solución de los requerimientos programáticos del proyecto, su concepción constructiva y el planteamiento consistente de los espacios requeridos, en este caso, para una casa-estudio.

  11. Conteúdos hipermodais para fins de aprendizagem: usos em contexto pelos alunos Hypermodal content to learning: student's contextualized use

    Directory of Open Access Journals (Sweden)

    Eduardo S Junqueira

    2010-12-01

    Full Text Available A análise dos usos de artefatos e conteúdos hipermodais pelos alunos, para fins de aprendizagem na modalidade do ensino a distância, indicou dois elementos-chave. A estrutura e a coesão dos conteúdos, identificados a partir de categorias estáveis de análi se semiótica de materiais hipermodais, não determinaram o uso. Norteados por elemen tos culturais e por suas intenções, os alunos formularam práticas comunicativas que extrapolaram a dicotomia impresso/digital. Imprimiram os conteúdos disponibilizados na tela do computador e instituíram a centralidade do impresso para a aprendizagem, sem, no entanto, ignorar os conteúdos hipermodais. A partir do impresso, utilizaram tais conteúdos em "rede" e construíram trilhas de navegação e leitura coerentes, voltadas a fins de aprendizagem específicos. Indica-se a necessidade de processos flexíveis e com a participação dos usuários-alunos para a produção de conteúdos mais interativos e democráticos.The analysis of the use of hypermodal artifacts and content by distance learning students indicated two key elements. Content structure and cohesion, estab lished by stable semiotic categories of hypermodal artifact's analysis, indicated that they have not determined the student's use. Guided by cultural elements and their own goals, students established communicative practices that extrapolated the print/digital dichoto my. The students printed the online content and established the centrality of the print ing material for their learning without disregarding hypermodal content. From the print ing material, they used content as "webs" and developed paths as they coherently navi gated and read the materials. The study indicates the need to establish flexible, open to participation processes of content design aimed at the student's participation to produce more interactive and democratic content for the production of learning.

  12. UTILIZAÇÃO DO CUSTEIO POR ABSORÇÃO PARA FINS GERENCIAIS

    OpenAIRE

    César Augusto Tibúrcio Silva

    2009-01-01

    O urso grizzly gasta o outono a caçar e comer marmotas (McGee, 294). Para tanto, ele move grandes e profundas pedras. Considerando em termos globais, este trabalho do urso, quando comparado com o seu tamanho e o da marmota, leva à conclusão de que o urso desperdiça tempo e energia. Como o inverno é geralmente longo e rigoroso, esta dedução pode ser precipitada. O urso talvez esteja praticando esporte, divertindo-se ou exercitando-se ou talvez variando sua dieta. Ou ainda tudo isto em conjun-t...

  13. UTILIZAÇÃO DE MÉTODOS DE CUSTEIO PARA FINS GERENCIAIS: ADERÊNCIA EMPÍRICA EM EMPRESAS DA REGIÃO SUL DO BRASIL

    OpenAIRE

    Gabriel Grubel Bandeira; Maicon Manoel Benin; Marcos Antônio de Souza; Débora Gomes Machado

    2017-01-01

    Esta pesquisa teve como objetivo determinar, para fins gerenciais, qual é a aderência empírica dos métodos de custeio em empresas da Região Sul do Brasil. Para atingir o objetivo deste estudo foi realizado um estudo de campo qualitativo e descritivo. A pesquisa foi realizada por meio de entrevista com os gestores de cinco empresas de diferentes setores da economia. Os resultados demonstram que as empresas pesquisadas, utilizam método de custeio para auxiliar na geração de informações à tomada...

  14. Un modelo conceptual para la realización del Trabajo Fin de Gradoapoyado en el uso de las TICs

    Directory of Open Access Journals (Sweden)

    Úrsula Faura -Martínez

    2017-01-01

    Full Text Available En el actual escenario del ámbito universitario l as herramientas de la tecnología y la comunicación (TIC están siendo empleadas para favorecer nuevos enfoques metodológicos con un matiz claramente colaborativo proporcionando una im portante proyección en los procesos de innovación educativa. Este trabajo describe una experiencia desarrollada en el ámbito universitario, cuyo objetivo es crear un modelo conceptual que refleje la influencia del trabajo colaborativo generado a través de las tutorías grupales y el uso de las TICs en el rendimiento académico en la elaboración del T rabajo Fin de Grado (TF G . Participaron estudiantes de los Grado s en Administración y Dirección de Empresas y M arketing de la Universidad de Murcia durante tres c ursos académicos . El 100% de los estudiantes que siguieron esta metodología superaron con éxito la evaluación del TFG. El 40 % obtuvo una nota superior a 9, el 23,3 % entre 8 y 9 y un 20 % superó la evaluación con matrícula de honor . Se concluye que esta form a de desarrollar el proyecto basada en las tutorías grupales, el trabajo colaborativo y el uso de TIC favorece la elaboración de l TFG , obteniendo unos resultados excelentes , produciéndose menos diferencias en las notas obtenidas y no hallándose ninguna inf luencia del sexo en dichos resultados.

  15. UTILIZAÇÃO DE MÉTODOS DE CUSTEIO PARA FINS GERENCIAIS: ADERÊNCIA EMPÍRICA EM EMPRESAS DA REGIÃO SUL DO BRASIL

    Directory of Open Access Journals (Sweden)

    Gabriel Grubel Bandeira

    2017-01-01

    Full Text Available Esta pesquisa teve como objetivo determinar, para fins gerenciais, qual é a aderência empírica dos métodos de custeio em empresas da Região Sul do Brasil. Para atingir o objetivo deste estudo foi realizado um estudo de campo qualitativo e descritivo. A pesquisa foi realizada por meio de entrevista com os gestores de cinco empresas de diferentes setores da economia. Os resultados demonstram que as empresas pesquisadas, utilizam método de custeio para auxiliar na geração de informações à tomada de decisão gerencial, apenas varia a finalidade para qual o empregam. A combinação de métodos mais observada foi a do custeio ABC, custeio variável e custeio direto, destaca-se que a aplicação foi parcial e de forma simultânea, sendo que cada método de custeio contribui para a gestão de acordo com o benefício específico de cada um. O método de custeio absorção que é utilizado para cumprimento da legislação fiscal.

  16. Caracterização físico-química de misturas de óleos vegetais para fins alimentares.

    OpenAIRE

    ALMEIDA, K. M. de; MEDEIROS, E. P. de; GOMES, J. P.; SOUSA, E. P. de; SANTOS, J. W. dos

    2014-01-01

    Objetivou-se, com este trabalho, a elaboração e caracterização de misturas especiais de óleos vegetais para fins alimentícios, com base nos óleos de amendoim, gergelim, maracujá e soja. Os óleos de amendoim e gergelim foram extraídos de sementes das cultivares BRS-Havana e BRS-Seda, respectivamente, cedidas pela Embrapa Algodão enquanto o óleo de maracujá foi adquirido no comércio de São Paulo e o de soja no de Campina Grande. As misturas foram elaboradas com base em uma matriz de planejament...

  17. Potencialidade de uso de fontes alternativas de água para fins não potáveis em uma unidade residencial

    OpenAIRE

    Peters, Madelon Rebelo

    2006-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pos-Graduação em Engenharia Ambiental. O uso racional da água compreende o controle de desperdícios e uma re-educação de hábitos e costumes. Esta re-educação está associada ao uso de fontes alternativas como, por exemplo, os efluentes tratados gerados na própria residência e a captação de águas pluviais, em substituição a água potável para fins que não seja o consumo humano. O uso de águas de c...

  18. O Marketing de Serviços e suas Implicações para uma Organização sem Fins Lucrativos

    OpenAIRE

    Magali Costa Guimarães

    2003-01-01

    Este estudo restringiu-se em tentar compreender a visão de marketing de serviços dos responsáveis por uma organização sem fins lucrativos. O objetivo centrou-se em conhecer se tais pessoas conhecem quem são, o que desejam e esperam seus clientes, como vêm utilizando os conceitos de marketing e como avaliam a qualidade dos serviços executados na organização à luz da teoria de marketing. O estudo traz algumas reflexões importantes sobre a utilização do marketing de valor para as organizações se...

  19. Caracterização físico-química de misturas de óleos vegetais para fins alimentares

    Directory of Open Access Journals (Sweden)

    Katcilanya Menezes Almeida

    2013-05-01

    Full Text Available Objetivou-se, com este trabalho, a elaboração e caracterização de misturas especiais de óleos vegetais para fins alimentícios, com base nos óleos de amendoim, gergelim, maracujá e soja. Os óleos de amendoim e gergelim foram extraídos de sementes das cultivares BRS-Havana e BRS-Seda, respectivamente, cedidas pela Embrapa Algodão enquanto o óleo de maracujá foi adquirido no comércio de São Paulo e o de soja no de Campina Grande. As misturas foram elaboradas com base em uma matriz de planejamento experimental e, em seguida, submetidas aos ensaios físico-químicas (umidade, índice de acidez, índice de iodo, índice de refração, densidade e viscosidade segundo a metodologia do IAL (2008. Os resultados foram submetidos à análise de variância (ANOVA por delineamento inteiramente casualizado com 17 tratamentos e 6 variáveis pelo software ASSISTAT versão 7.6 beta. Todas as misturas diferiram estatisticamente entre si a nível de 1% pelo teste de Tukey e apresentaram-se aptas para fins alimentares, com influência da significante quantidade de ácidos graxos insaturados em todas as medidas físico-quimicas. Os óleos de maracujá e soja são quimicamente semelhantes.

  20. Análise do EIA/RIMA do Terminal de Combustíveis da Paraíba (TECOP para fins de licenciamento ambiental

    Directory of Open Access Journals (Sweden)

    Valdeniza Delmondes Pereira

    2016-09-01

    Full Text Available O estudo de impacto ambiental precede ao licenciamento ambiental, sendo obrigatório para atividades efetiva ou potencialmente poluidoras ou capazes de degradar o meio ambiente. Este trabalho teve como objetivo fazer a análise do EIA/RIMA do Terminal de Combustíveis da Paraíba Ltda-TECOP, observando se foram cumpridas as exigências legais para a caracterização dos impactos ambientais, e verificando também a existência de medidas mitigadoras para os impactos adversos e indicação de monitoramento para os referidos impactos identificados. Trata-se de uma pesquisa descritiva e documental, que teve como objetos de estudo, o EIA/RIMA e o Processo de Licenciamento Ambiental do TECOP, cujos dados foram coletados junto ao Setor de Documentação da SUDEMA. O EIA/RIMA se mostrou extremamente superficial no que diz respeito à caracterização dos impactos ambientais, estes não sendo devidamente caracterizados conforme determina a Resolução Conama 01/86, artigo 6, inciso II. Os atributos para a correta caracterização dos impactos não foram levados em consideração sequer para os principais impactos adversos passíveis de ocorrerem na fase de operação do empreendimento. O estudo também não mostrou clareza quanto à proposição das medidas mitigadoras e monitoramento para os impactos identificados, pois nem todos os impactos adversos continham a indicação de mitigação e como seriam monitorados.

  1. QUALIDADE DE ÁGUAS PARA FINS DE IRRIGAÇÃO DA REGIÃO DO CONGO, PB

    Directory of Open Access Journals (Sweden)

    Jacqueline da Silva Mendes

    2008-01-01

    Full Text Available The research was carried out to evaluate the quality of waters used in the irrigation of agricultural areas of Congo region, Paraíba State, Brazil. The water samples were collected in Cordeiro dam, in wells and in river, in two periods of the year, rainy (May/2006 and dry period (December/2006 and analyzed under the qualitative aspects of salinity, sodicity and toxicity of ions. For the studied conditions and in agreement with the evaluated parameters in both periods, most of the samples of water, as for the salinity, were considered normal for the use in the irrigation since special practical of soil and water management are adopted; as the toxicity of the ion sodium, more than 40% didn't present restriction to the use. In relation to the toxicity of the ion chloride, in the rainy period, 61% of the samples didn't indicate restriction to the use for irrigation and in the dry period, 44% presented restriction varying from low to moderate.

  2. Proposta de metodologia para o cadastro territorial para fins de regularização fundiária em áreas de interesse social

    Directory of Open Access Journals (Sweden)

    Kleber Rafael de Almeida

    Full Text Available O presente trabalho apresenta o modelo de regularização fundiária adotado pela Prefeitura Municipal de Quatro Barras - PR, através do Programa Moradia Legal, visando a regulamentação das áreas da Vila Pinheirinho e, desta forma, legalizando a permanência dos moradores na região, de modo a garantir a qualidade de vida e bem estar da população com a implantação de infraestrutura urbana adequada. Atualmente os programas de regularização fundiária necessitam de uma correta mensuração dos limites da propriedade e um banco de dados. Para tanto, foi idealizada uma metodologia específica de cadastro territorial e regularização fundiária, a qual permitiu a tomada de decisões nesses processos junto à Defensoria Pública do Município. Assim, para a aplicação da referida metodologia foi definida uma área piloto composta de ocupações irregulares, sendo utilizados os dados cadastrais constantes no banco de dados geográfico da prefeitura. Confirmou-se com este experimento a função social do cadastro urbano como um instrumento de acesso à propriedade.

  3. Alimento para fins especiais: ingredientes, elaboração e aglomeração Food for special needs: ingredients, development and agglomeration

    Directory of Open Access Journals (Sweden)

    Luciana Azevedo

    2011-04-01

    Full Text Available OBJETIVO: Desenvolver uma dieta enteral nutricionalmente completa, com condições ajustadas de aglomeração, visando contemplar as características físicas e químicas desejadas para esse alimento especial. MÉTODOS: Como ingredientes foram utilizados maltodextrina, óleo de canola, triglicerídios de cadeia média, goma acácia, inulina e frutooligossacarídeos, proteínas do soro de leite, isolado proteico de soja, vitaminas e minerais. Após os ajustes das quantidades e proporções dos ingredientes, a formulação foi aglomerada e submetida às análises de composição centesimal, molhabilidade, densidade aparente, atividade de água, viscosidade e cor. RESULTADOS: Obteve-se uma fórmula contendo 1kcal.mL-1, normoproteica (3,9g.100mL-1 e normolipídica (3,9g.100mL-1. Após a aglomeração da dieta, observaram-se os seguintes resultados: molhabilidade de 0,262g.s-1, densidade aparente de 0,317g.cm-3e atividade de água de 0,393. A análise de cor indicou redução da luminosidade e aumento dos parâmetros de cor a*e b*, apresentando leve variação para o vermelho e forte presença do amarelo. CONCLUSÃO: Os ingredientes empregados, e suas respectivas proporções, bem como o processo de aglomeração, possibilitaram a obtenção de um alimento para fins especiais com propriedades bioativas. O processo de aglomeração possibilitou uma dieta de fácil reconstituição e utilização através de sondas, facilitando a infusão e, consequentemente, a diminuição de intercorrências.OBJECTIVE: This study aimed to develop a nutritionally complete enteral diet, with adjusted agglomeration conditions, and determine the physical and chemical characteristics required by this special food. METHODS: The ingredients were maltodextrin, canola oil, medium-chain triglycerides, acacia gum, inulin, fructooligosaccharides, milk whey protein, soy protein isolate, vitamins and minerals. After the quantities and proportions of the ingredients were adjusted

  4. Processo de credenciamento das escolas de magistraturas para fins de reconhecimento junto ao MEC e a adoção de padrões de qualidade na política de coleções para as bibliotecas jurídicas

    OpenAIRE

    Adriana Carla de Oliveira; Hallysson Nóbrega

    2017-01-01

    Descreve os procedimentos necessários para o credenciamento junto ao Ministério da Educação, das instituições de ensino, pertencentes à Administração Pública, especificamente as vinculadas aos órgãos da justiça, a saber, as Escolas de Magistratura, para fins da promoção e do auto-chancelamento de cursos de pós-graduação lato sensu. Para efeito da pesquisa foi realizada uma pesquisa documental e exploratória, acerca da legislação aplicada para o credenciamento de instituiç...

  5. Legislação de proteção animal para fins científicos e a não inclusão dos invertebrados - análise bioética

    OpenAIRE

    Oliveira, Elna Mugrabi; Goldim, José Roberto

    2014-01-01

    A legislação que regulamenta o uso de animais para fins científicos nos países ocidentais segue princípios semelhantes, diferindo apenas em complexidade e extensão. Em geral, a lei protege apenas os vertebrados por considerá-los dotados da capacidade de ter experiências subjetivas como dor e sofrimento. Estudos utilizando parâmetros fisiológicos, neuroanatômicos e comportamentais evidenciam a senciência em invertebrados como cefalópodes e decápodes, dando-lhes o direito de proteção legal em a...

  6. La importancia de los números especiales “fin de temporada” de la revista 6Toros6 como fuente de información especializada para la práctica periodística

    Directory of Open Access Journals (Sweden)

    María Verónica de Haro de San Mateo

    2010-01-01

    Full Text Available Este artículo estudia los números especiales “fin de temporada” editados por la revista 6TOROS6 con el objetivo de poner de relieve su importancia como fuente de información especializada para la práctica periodística. Los procedimientos metodológicos empleados han consistido en la descripción y el estudio de contenido de los ciento treinta y nueve ejemplares especiales publicados por este prestigioso semanario especializado en tauromaquia. Dicho estudio nos ha permitido constatar la objetividad de los apéndices estadísticos contenidos en estos anuarios así como el grado de especialización de los profesionales que los confeccionan. Y entre otros, estos valores nos han permitido concluir que los especiales “fin de temporada” de la revista 6TOROS6 son una válida y muy útil herramienta documental para el ejercicio de la actividad periodística.

  7. Viabilidade técnica de implantação de sistema de aproveitamento de água pluvial para fins não potáveis em universidade

    OpenAIRE

    Salla, Marcio Ricardo; Lopes, Gabriela Bernardi; Pereira, Carlos Eugênio; Moura Neto, João da Costa; Pinheiro, Aline Martins

    2013-01-01

    Este artigo tem como objetivo analisar a viabilidade técnica de implantação de sistema de aproveitamento de águas pluviais para fins não potáveis em uma edificação com salas de aula e anfiteatros na Universidade Federal de Uberlândia, no município de Uberlândia. Dois tipos de análise foram realizadas: sob o ponto de vista quantitativo, verificando se a quantidade de água pluvial coletada supre satisfatoriamente a demanda por água não potável; e sob o ponto de vista qualitativo, verificando se...

  8. Tráfico de Pessoas para fins de exploração do trabalho na cidade de São Paulo Human trafficking for labour exploitation in the city of São Paulo

    Directory of Open Access Journals (Sweden)

    Paulo Illes

    2008-12-01

    Full Text Available Este artigo busca contextualizar, em linhas gerais, o fluxo de imigrantes bolivianos para fins de trabalho nas oficinas de costura da cidade de São Paulo, demonstrando a interface dessa imigração com o tráfico de migrantes e o tráfico de pessoas. Por meio de depoimentos, são apresentadas as recorrentes dificuldades enfrentadas pelas trabalhadoras imigrantes.This article seeks to contextualize, along general lines, the Bolivian migratory flow towards sweatshops in the city of São Paulo, showing the interaction between this migratory flow, migrant smuggling and human trafficking. The most frequent problems faced by the migrant women are presented in testimonials.

  9. Caracterização de acessos de pimenta cumari de distribuição natural para fins de melhoramento genético

    Directory of Open Access Journals (Sweden)

    Marco Antônio Pereira Lopes

    2016-12-01

    Full Text Available A pimenta cumari (Capsicum baccatum var. baccatum, Capsicum baccatum var. praetermissum é uma espécie considerada semi-domesticada. As pesquisas no melhoramento genético e obtenção de plantas mais produtivas de pimenta cumari são de grande importância, uma vez que a cultura  é  pouco  difundida,  sendo  que  não  se  encontra  nenhuma  linhagem  comercial disponível. O presente trabalho teve como objetivo coletar, caracterizar materiais de pimenta cumari de distribuição natural e identificar materiais promissores a utilização em programas de melhoramento genético. Para isso, o trabalho foi divido em três etapas, sendo elas: coleta e identificação de materiais, análise da germinação e caracterização morfoagronômica. Na primeira fase foram realizadas visitas em propriedades de ocorrência de pimenta cumari, onde foram coletados frutos de nove plantas em regiões distintas para retirada de sementes, levantando as características das plantas e do local de ocorrência. Foram selecionados quatro materiais dos nove encontrados para implantação do ensaio, nomeadas de CH5, BI3, MA2 e CH2. A segunda etapa consistiu na avaliação da germinação das sementes com a adoção de algumas técnicas para quebra de dormência das sementes. Na última etapa foram realizadas avaliações para caracterização da planta de pimenta e dos seus frutos. Os dados foram submetidos à Análise de Variância, onde não obteve diferenças significativas para as características avaliadas.  Logo, pode-se observar que qualquer um dos materiais coletados apresenta potencial para utilização em programa de melhoramento genético.

  10. Técnicas de utilização de dicionário como material didático na aula de LE para fins específicos

    Directory of Open Access Journals (Sweden)

    Camila Höfling

    2006-01-01

    Full Text Available Este artigo apresenta uma metodologia de trabalho relacionado ao uso do dicionário como material didático na aula de língua estrangeira com fins específicos, em atividades como desenvolvimento de vocabulário, gramática, pronúncia, uso de língua, cultura, leitura e interpretação de texto. Com certas técnicas, os professores podem aproveitar esse material em suas aulas e orientar seus alunos sobre qual dicionário adquirir e como empregá-lo de maneira eficiente. Oferecemos algumas sugestões de atividades para serem realizadas com o dicionário, seja em aulas para alunos particulares ou em cursos profissionalizantes em áreas específicas.This paper presents a methodology related to the use of dictionary as a pedagogic resource in the foreign language for specific purposes class, in activities developing vocabulary, grammar, pronunciation, language use, culture, and reading comprehension. By using some techniques, teachers can benefit from this resource in class and instruct their students about how to choose and use a dictionary properly. We offer some suggestions of activities to be performed both in private classes (one-to-one and with groups of professionals with specific purposes.

  11. APLICACIÓN INFORMÁTICA PARA LA EVALUACIÓN DE RIESGOS INDUSTRIALES A FIN DE DETERMINAR UN INDICADOR DE RIESGOS EN EMPRESAS VENEZOLANAS

    Directory of Open Access Journals (Sweden)

    Liliana Manduca Alvarado

    2008-11-01

    Full Text Available

    Con la aplicación del sistema para la evaluación de riesgos industriales (SIPERI descrito en el trabajo, la autora logra facilitar la evaluación del indicador de riesgos de las empresas. La metodología propuesta obliga a que las empresas cumplan los pasos esenciales de control de gestión en cuanto a planificar, organizar, dirigir y controlar los riesgos industriales. La disminución del indicador de riesgos industriales (IRI, es un incentivo económico para las entidades y exige el mejoramiento continuo de la seguridad en el trabajo a partir del control sistemático de las condiciones de trabajo.

  12. The shark's fin

    International Nuclear Information System (INIS)

    Listinsky, J.L.; Griffiths, H.J.

    1989-01-01

    Initial plain film studies of seven patients with facet fracture-dislocations of the cervical spine were examined retrospectively. Rotation of the cross-table lateral film from a standard vetical viewing orientation to a simulated brow-down position allowed easier appreciation of the dislocated pillar in six of the seven patients. The displaced pillar had an appearance similar to that of the dorsal fin of a shark. We conclude that the finding of a shark's fin appearance of an articular pillar in a traumatized patient warrants further radiographic studies. (author). 8 refs.; 3 figs

  13. ÍNDICE DE ESTRESSE HÍDRICO NA CULTURA DO ALGODÃO PARA FINS DO MANEJO DE IRRIGAÇÃO

    Directory of Open Access Journals (Sweden)

    Silvia Oliveira Dayube

    2017-02-01

    Full Text Available A cotonicultura é uma atividade praticada em grande escala no Brasil e tem grande importância social e econômica, sendo de fundamental importância o uso da irrigação Para um manejo de irrigação mais racional, o monitoramento dos parâmetros fisiológicos da planta se destaca como o controle ideal. Assim, objetivou-se verificar a variação do índice de estresse hídrico na cultura do algodão irrigado (determinado através de termômetro de infravermelho em função do déficit de umidade no solo. O estudo foi realizado em Fazenda, durante o período de 10 de março a 11 de junho do ano de 2015. Foram coletadas, amostras de solo indeformadas para determinação da umidade atual, conforme o Método-Padrão de Estufa. O cálculo do Crop Water Stress Index (CWSI foi feito em função dos valores de: temperatura foliar, umidade relativa do ar, e temperatura do ar adquiridos por meio de um termômetro infravermelho. Valores de CWSI variam de forma proporcional ao déficit de umidade no solo. A metodologia tem potencial para ser utilizada na realização do manejo de irrigação.

  14. Processo de credenciamento das escolas de magistraturas para fins de reconhecimento junto ao MEC e a adoção de padrões de qualidade na política de coleções para as bibliotecas jurídicas

    Directory of Open Access Journals (Sweden)

    Adriana Carla de Oliveira

    2017-12-01

    Full Text Available Descreve os procedimentos necessários para o credenciamento junto ao Ministério da Educação, das instituições de ensino, pertencentes à Administração Pública, especificamente as vinculadas aos órgãos da justiça, a saber, as Escolas de Magistratura, para fins da promoção e do auto-chancelamento de cursos de pós-graduação lato sensu. Para efeito da pesquisa foi realizada uma pesquisa documental e exploratória, acerca da legislação aplicada para o credenciamento de instituições de ensino superior referente aos critérios exigidos pela Secretaria de Ensino Superior (Sesu, vinculada ao Ministério da Educação (MEC. Também foram descritos os padrões de qualidade esperados e a descrição do processo necessário para a auferição do referido credenciamento, bem como, os procedimentos necessários para as bibliotecas, que se aplica ao contexto jurídico. Destacam-se os critérios de uma política de desenvolvimento de coleções. E por fim, o processo de chancelamento da Escola de Magistratura do Rio Grande do Norte.

  15. Caracterização dos parâmetros de recozimento de aços totalmente processados para fins elétricos

    OpenAIRE

    Gebler, Sérgio Roberto

    2000-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. A busca mundial pela redução do consumo de energia tem incitado os fabricantes de motores elétricos a procurar alternativas para aumentar o rendimento de seus produtos. Dentre as diversas variáveis que estão envolvidas no processo produtivo, merece destaque a influência exercida pelos parâmetros do ciclo de tratamento térmico a que são submetidos os aços utilizados na fabricação de rotores e estatores. A d...

  16. Comparação entre métodos de valoração de danos ambientais para fins periciais

    Directory of Open Access Journals (Sweden)

    Thais Brasil Barros da Silva

    2015-11-01

    Full Text Available Este trabalho avaliou 24 métodos e procedimentos de valoração ambiental e selecionou dois deles (Taxa de Juros e Custo de Oportunidade para utilizá-los na comparação com valores de danos ambientais precificados em laudos do Instituto de Criminalística (IC da Polícia Civil do Distrito (PCDF. Entre 2.014 laudos de crimes ambientais emitidos pelo IC/PCDF no período de 2009 a 2014, 598 laudos apresentavam a precificação dos danos constatados. Os valores dos danos indiretos presentes nos laudos foram recalculados por meio da aplicação de uma taxa de juros de 12% ao ano sobre o valor do Custo de Reposição (danos diretos presentes nos mesmos laudos. Os valores dos danos totais presentes nos laudos foram recalculados por meio do método Custo de Oportunidade. Os resultados indicaram que os diferentes métodos produzem valores de danos ambientais que apresentam pouca ou nenhuma relação de equivalência ou proporcionalidade entre si. Portanto, o valor dos danos ambientais foi determinado pelo método utilizado para precificá-los e não por fatores ambientais relacionados ao dano.

  17. Fin de Copenhague

    DEFF Research Database (Denmark)

    Baumeister, Ruth

    2016-01-01

    FIN DE COPENHAGUE this book by the Danish Cobra artist Asger Jorn and the French philosopher Guy Debord, is the first in a series of two and was published in 1957, shortly before the authors founded the Situationist International. According to Jorn, upon arrival to Copenhagen, they stole some...

  18. Uma cidade criativa de tipo relacional: Para uma cartografia das ligações em rede entre os setores público, privado e sem fins lucrativos nas indústrias criativas

    Directory of Open Access Journals (Sweden)

    Roberta Comunian

    2013-09-01

    Full Text Available Tem sido grande a atenção recentemente dada ao papel que as artes, a cultura e a criatividade podem desempenhar na requalificação e desenvolvimento das cidades. Neste quadro, o presente artigo utiliza a análise de redes sociais (ARS com vista a investigar não só o impacto decorrente da requalificação física, mas também o papel desempenhado pelas redes de conhecimento e de apoio no contexto da economia criativa urbana. Embora o método não seja novo, a sua adoção pelos estudiosos deste tema tem sido pouco significativa. Tomando como exemplo o estudo levado a cabo em Newcastle‑Gateshead e na região do Nordeste da Inglaterra, que investigou as redes e as relações existentes entre as indústrias criativas, o trabalho que aqui se apresenta visa trazer a este debate um contributo metodológico e teórico. Os resultados evidenciam a importância das redes de conhecimento e de apoio no campo das indústrias criativas, apontando para a necessidade de adotar uma abordagem baseada nas redes pessoais para compreender cabalmente quem são os atores‑chave de um dado sistema local e de que modo eles interagem. Longe de restringir ao plano empresarial as interações baseadas no conhecimento, o artigo mostra, além disso, a importância das interligações com os setores público e sem fins lucrativos.

  19. Esplanada: cultivar de cenoura de verão para fins de processamento Esplanada: a new tropical carrot variety suitable for minimum processing

    Directory of Open Access Journals (Sweden)

    Jairo V. Vieira

    2005-07-01

    Full Text Available A cenoura é uma das hortaliças tradicionais mais consumidas no Brasil. Entretanto, o consumo de mini cenouras tipo "cenourete" obtidas via processamento mínimo ainda é muito pequeno no país. Isto se deve possivelmente ao restrito conhecimento da tecnologia de produção deste produto e da dificuldade em se obter matéria prima de qualidade e com regularidade, especialmente no período de verão. As raízes das principais cultivares utilizadas no Brasil não apresentam características de qualidade como coloração, formato e tamanho adequados para possibilitar máximo rendimento industrial. Neste contexto, foi desenvolvida a cultivar de polinização aberta "Esplanada", que apresenta boa adaptação às condições edafoclimáticas brasileiras, possui alta resistência à queima-das-folhas, baixa incidência de florescimento precoce no verão e resistência moderada a nematóides formadores de galhas. Estas características viabilizam seu cultivo em qualquer época do ano, nas principais regiões de produção. As raízes são compridas, finas e apresentam coloração uniforme, características estas adequadas para o processamento mínimo visando a produção de cenourete. Esta cultivar poderá ocupar posição estratégica na cadeia produtiva de cenoura, uma vez que vai possibilitar a produção de mini cenouras durante todo o ano em qualquer região do país.Carrot is one of the most consumed vegetables in Brazil. However, the consumption of "baby carrots", obtained by minimally processed roots, is still very low in the country, due to lack of processing technology knowledge and the low amount of minimally processed carrots produced in Brazil as a consequence of the low industrial productivity. The carrot varieties currently employed in minimum processing have as major disadvantages a series of low quality attributes including inadequate root shape and size which precludes reaching the maximum industrial yield. In this context, Embrapa

  20. Caracterização físico-química e microbiológica do esgoto da UEPB com proposta de tratamento para fins de reuso

    Directory of Open Access Journals (Sweden)

    M. U. Sousa

    2015-12-01

    Full Text Available Nos últimos anos, a preocupação com as questões ambientais vem sendo bastante discutidas, onde merece destaque, o descarte indevido do esgoto doméstico no meio ambiente, portanto o presente estudo objetivou realizar a caracterização físico-química e microbiológica do esgoto descartado no solo, no Centro de Ciências e Tecnologia da Universidade Estadual da Paraíba, campus de Campina Grande – PB. Para tanto foram desenvolvidas análises físico-químicas, tais como pH, Fósforo Total, DBO, DQO, Nitratos, Nitritos, Nitrogênio Amoniacal, Orto-Fosfatos e Alcalinidade, bem como análise microbiológica (coliformes. Observou-se que o efluente na unidade em questão não recebe tratamento para seu descarte, sendo identificadas características físico-químicas e microbiológicas de esgoto in natura. Faz-se necessário desta forma, investimentos em análises periódicas para assim realizar um tratamento adequado ao efluente visando-se reduzir os riscos ambientais e de saúde pública. Após os resultados das análises, foi proposto, além do tratamento preliminar, um tratamento biológico para o efluente, do tipo, lagoa facultativa primária seguida de duas lagoas de maturação, onde a eficiência do tratamento nos parâmetros analisados se enquadra aos padrões estabelecidos pelo CONAMA 430/2011, na qual o efluente pós - tratado poderia ser reutilizado para fins menos nobres, destinando a água potável para atividades que requerem uma qualidade melhor.Physicochemical and microbiological characterization of wasterwater of the UEPB with proposed of treatment for reuse purposesAbstract: In recent years, concern about environmental issues has been widely discussed, which deserves mention the improper disposal of domestic sewage into the environment, so this study aimed to perform the physicochemical and microbiological sewage discarded the soil, in the Science and Technology Center of the State University of Paraiba, campus of Campina

  1. El fin del petróleo

    OpenAIRE

    Fontaine, Guillaume

    2007-01-01

    En el momento en que los demócratas de los Estados Unidos han encabezado, al parecer, la cruzada mundial contra el cambio climático, quizá no es inútil leer (o releer) el ensayo del periodista Paul Roberts, publicado a finales del 2004 bajo el título llamativo de "El fin del petróleo". En efecto, cuando se reactivan las recetas del "charity business" (como eran los megaconciertos contra la hambruna y la sequía en Somalia, o para la liberación de Mandela) para salvar nuestro planeta, y m...

  2. Fully-Implicit Navier-Stokes (FIN-S)

    Science.gov (United States)

    Kirk, Benjamin S.

    2010-01-01

    FIN-S is a SUPG finite element code for flow problems under active development at NASA Lyndon B. Johnson Space Center and within PECOS: a) The code is built on top of the libMesh parallel, adaptive finite element library. b) The initial implementation of the code targeted supersonic/hypersonic laminar calorically perfect gas flows & conjugate heat transfer. c) Initial extension to thermochemical nonequilibrium about 9 months ago. d) The technologies in FIN-S have been enhanced through a strongly collaborative research effort with Sandia National Labs.

  3. Desenvolvimento e validação de meio de cultura para detecção de Pseudomonas Aeruginosa em água purificada para fins farmacêuticos

    OpenAIRE

    Albini, Bárbara Pereira

    2012-01-01

    Resumo: A água purificada é uma das principais matérias-primas para medicamentos e cosméticos. Participa efetivamente de processos de esterilização por via úmida, limpeza de equipamentos e é utilizada nas análises de controle de qualidade. Assim, influencia diretamente na qualidade dos produtos e portanto deve seguir um rigoroso parâmetro de qualidade físico-químico e microbiológico. A Farmacopéia Brasileira 5 ed. que passa a vigorar em fevereiro do presente ano, indica como parâmetro microbi...

  4. Caracterização molecular e variabilidade genética de acessos elite de mandioca para fins industriais Molecular characterization and genetic variability of elite cassava accessions for industrial purpose

    Directory of Open Access Journals (Sweden)

    Eduardo Alano Vieira

    2010-12-01

    Full Text Available Marcadores moleculares são ferramentas úteis na caracterização molecular de acessos de mandioca, em razão de apresentarem elevada capacidade de detecção das informações contidas no genoma. O objetivo deste trabalho foi caracterizar, por meio de marcadores RAPD, 20 acessos de mandioca para fins industriais conservados no Banco Regional de Germoplasma de Mandioca do Cerrado (BGMC. Em laboratório, os acessos foram avaliados por meio de marcadores RAPD, sendo posteriormente estimada a matriz de similaridade genética entre os acessos, por meio do índice de Jaccard. A análise, feita através de 11 iniciadores, gerou um total de 120 marcadores RAPD, dos quais 74 (62% foram polimórficos, revelando a presença de elevada variabilidade genética no grupo de acessos avaliados. A análise de agrupamento revelou a formação de apenas um agrupamento forte, formado pelos acessos BGMC 1130, BGMC 788, BGMC 1270 e BGMC 1107, o que indica que, no melhoramento genético de mandioca, não devem ser priorizadas hibridações entre esses acessos, sob pena de efeitos de endogamia. Por sua vez, o acesso BGMC 436 foi o mais divergente em relação aos demais e, como expressa elevado potencial produtivo na região do Cerrado do Brasil Central, representa boa opção como genitor para o melhoramento de mandioca para essa região. O estudo comprovou que os marcadores RAPD são eficientes na determinação da variabilidade genética dos acessos avaliados e que neste grupo existe elevada variabilidade genética passível de ser utilizada no melhoramento genético.Molecular markers are useful tools for the molecular characterization of cassava accessions since they present high capacity to detect information within the genome. The aim of this research was to characterize through RAPD molecular markers, 20 industrial cassava accessions conserved in the Cerrado Cassava Regional Germoplasm Bank ("Banco Regional de Germoplasma de Mandioca do Cerrado"-BGMC. Upon

  5. Toward quantum FinFET

    CERN Document Server

    Wang, Zhiming

    2013-01-01

    This book reviews a range of quantum phenomena in novel nanoscale transistors called FinFETs, including quantized conductance of 1D transport, single electron effect, tunneling transport, etc. The goal is to create a fundamental bridge between quantum FinFET and nanotechnology to stimulate readers' interest in developing new types of semiconductor technology. Although the rapid development of micro-nano fabrication is driving the MOSFET downscaling trend that is evolving from planar channel to nonplanar FinFET, silicon-based CMOS technology is expected to face fundamental limits in the near future. Therefore, new types of nanoscale devices are being investigated aggressively to take advantage of the quantum effect in carrier transport. The quantum confinement effect of FinFET at room temperatures was reported following the breakthrough to sub-10nm scale technology in silicon nanowires. With chapters written by leading scientists throughout the world, Toward Quantum FinFET provides a comprehensive introductio...

  6. Channels with Different Fin Shapes

    Directory of Open Access Journals (Sweden)

    R. J. Goldstein

    1998-01-01

    Full Text Available The mass transfer (analogous to heat transfer and pressure loss characteristics of staggered short pin-fin arrays are investigated experimentally in the range of Reynolds number 3000 to 18,000 based on fin diameter and mean approach-flow velocity. Three different shapes of fins with aspect ratio of 2 are examined: one uniform-diameter circular fin (UDCF and two stepped-diameter circular fins (SDCF1 and SDCF2. Flow visualization using oil-lampblack reveals complex flow characteristics associated with the repeated production of horseshoe vortices and fin wakes, and the interactions among these. The SDCF1 and SDCF2 arrays show flow characteristics different from the UDCF array due to downflow from the steps. For all arrays tested, the near-endwall flow varies row by row in the initial rows until it reaches a stable pattern after the third row. The row-averaged Sherwood numbers obtained from the naphthalene sublimation experiment also show a row-by-row variation pattern similar to the flow results. While the SDCF2 array has the highest mass transfer rate, the SDCF1 array has the smallest pressure loss at the same approach-flow velocity. The fin surfaces have higher array-averaged Sherwood number than the endwall and the ratio between these changes with fin shape and Reynolds number. The performance of the pin-fin arrays is analyzed under two different constraints: the mass[heat transfer rate at fixed pumping power, and the mass/heat transfer area and pressure loss to fulfill fixed heat load at a fixed mass flow rate. In both cases, the SDCF2 array shows the best performance.

  7. FinTech in Denmark

    OpenAIRE

    Hategan, Ramona Anamaria; Mockus, Gytis; Trinkunaite, Sarune

    2017-01-01

    ABSTRACTThe purpose of this paper has been to seek understanding and knowledge of FinTech phenomenon, with a particular focus on the effect of its emergence on the Danish financial sector. We have attempted to answer our initial research question with the help of a theoretical and methodological framework conceived of concepts belonging to Actor-Network Theory, Diffusion of Innovation Theory and alluding to Foucault’s concepts of power, knowledge and discourses. We have followed FinTech as an...

  8. Effect of the Curved Fin Top Edge on the Electrical Characteristics of FinFETs.

    Science.gov (United States)

    Ahn, Joonsung; Kim, Tae Whan

    2018-03-01

    The effect of the curved fin top edge on the electrical characteristics of FinFETs was investigated. The curvature radius of the fin top edge for the FinFETs was changed from 0 to 5 nm in order to determine the optimum condition of the electrical characteristics for the devices. The on-current level of the FinFETs with a curvature radius of 5 nm of fin top edge was 24.45% larger than that of the FinFETs with a cuboid fin. The electron current density and the electron mobility of the fin top edge for the FinFETs were larger than those for the FinFETs with a cuboid fin. The electrical characteristics of the FinFETs with a curvature radius of 5 nm for the fin top edge showed the best performance due to the largest expansion of the effective channel region.

  9. La Sociedad del Conocimiento y el Fin de la Escuela

    OpenAIRE

    Rodríguez Rojas, Pedro

    2004-01-01

    Educere:Una Brizna de Aliento en el Tiempo Rivas, Pedro El Paradigma Reinante y su Paideia Alonso, Leonor La Experiencia Contemporánea como Expresión del Fin de una ÉticaAlgunas Ideas desde la Postmodernidad para Releer el Dato Educativo Perdomo, José Camilo La Sociedad del Conocimiento y el Fin de la Escuela Rodríguez Rojas, Pedro Escuela, Alteridad y Experiencia de SíLa Producción Pedagógica del Sujeto Valera Villegas, G...

  10. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Shark finning; possession at sea and landing of shark fins. 600.1204 Section 600.1204 Wildlife and Fisheries FISHERY CONSERVATION AND... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No...

  11. Fin Ray Stiffness and Fin Morphology Control Ribbon-Fin-Based Propulsion.

    Science.gov (United States)

    Liu, Hanlin; Taylor, Bevan; Curet, Oscar M

    2017-06-01

    Ribbon-fin-based propulsion has rich locomotor capabilities that can enhance the mobility and performance of underwater vehicles navigating in complex environments. Bony fishes using this type of propulsion send one or multiple traveling waves along an elongated fin with the actuation of highly flexible rays that are interconnected by an elastic membrane. In this work, we study how the use of flexible rays and different morphology can affect the performance of ribbon-fin propulsion. We developed a physical model composed of 15 rays that are interconnected with an elastic membrane. We tested four different ray flexural stiffness and four aspect ratios. The robotic model was tested in a low-turbulence flume under two flow conditions ([Formula: see text] wavelength/s). In two experimental sets, we measured fin kinematics, net surge forces, and power consumption. Using these data, we perform a thrust and power analysis of the undulating fin. We present the thrust coefficient, power coefficient, and propulsive efficiency. We find that the thrust generation was linear with the enclosed area swept by the fin, and square of the relative velocity between the incoming flow and traveling wave. The thrust coefficient levels off around 0.5. In addition, for our parameter range, we find that the power consumption scales by the cube of the effective tangential velocity of the rays [Formula: see text] (A is the amplitude of the ray oscillating motion, and [Formula: see text] is the angular velocity). We show that a decay in stiffness decreases both thrust production and power consumption. However, for rays with high flexural stiffness, the difference in thrust compared with rigid rays is minimal. Moreover, our results show that flexible rays can improve the propulsive efficiency compared with a rigid counterpart. Finally, we find that the morphology of ribbon fin affects its propulsive efficiency. For the aspect ratio considered in our experiments, [Formula: see text] was the most

  12. PHASE CHANGE AROUND A FINNED TUBE

    Directory of Open Access Journals (Sweden)

    Aytunç EREK

    2003-01-01

    Full Text Available This study presents the heat transfer enhancement in the thermal energy storage system by using radially finned tube. The solution of the system consists of the solving the equations of the heat transfer fluid (HTF, the pipe wall and fin, and the phase change material (PCM as one domain. The control volume finite difference approach and the semi implicit solver (SIS are used to solve the equations. Fully developed velocity distribution is taken in the HTF. Flow parameters (Re number and inlet temperature of coolant and fin parameters (the number of fins, fin length, fin thickness are found to influence solidification fronts and the total stored energy.

  13. Captação de recursos financeiros em organizações sem fins lucrativos: a utilização de indicadores de gestão para os doadores e beneficiários dos projetos sociais Financial funding for non-profit organizations: management indicators for donors and beneficiaries of social projects

    Directory of Open Access Journals (Sweden)

    Nilceia Cristina dos Santos

    2008-01-01

    Full Text Available As organizações sem fins lucrativos encontram dificuldades na captação de recursos financeiros destinados a projetos sociais, já que mais organizações dessa natureza surgem a cada ano e as instituições financiadoras não tendem a surgir na mesma proporção. Dessa forma, é imprescindível a existência de métricas que possam auxiliar os gestores de tais empresas na efetividade da captação dos recursos. O objetivo deste artigo é justamente contribuir para a eficácia dos gestores nesse processo de gestão. Mais especificamente, o artigo propõe uma adaptação do modelo de indicadores de desempenho baseado no marco lógico desenvolvido pela United States Agency for International Development (USAID e no balanced scorecard (BSC de Kaplan e Norton, de modo a auxiliar as organizações sem fins lucrativos na captação de recursos. Neste artigo, são construídas quatro proposições sobre indicadores de desempenho. Também são fornecidos dois quadros com indicadores de desempenho para as associações voltadas às crianças e adolescentes, no intuito de traduzir as proposições e resultados da discussão efetuada. Dessa forma, o artigo busca contribuir com novas idéias, especificando melhor os conceitos teóricos desenvolvidos pela USAID e por Kaplan e Norton e fornecendo constructos operacionalizáveis para uma melhor gestão das empresas sociais e sem fins lucrativos.Non-profit organizations face difficulties in obtaining financial funding for their social projects because there are more new competing organizations while the number of funding sources does not grow at the same rate. Therefore managers must have appropriate measuring means enabling them to achieve efficiency in financial funding. For this reason adaptation of the model of performance indicators based on those developed by the United States Agency for International Development (USAID and the Balanced Scorecard by Kaplan & Norton were proposed to help non

  14. Uma contribuição ao estudo dos métodos de custeio tradicionais e do método de custeio baseado em atividades (ABC) quanto a sua aplicação numa empresa pesqueira cearense para fins de evidenciação de resultado.

    OpenAIRE

    Afonso Celso Pagano Frossard

    2003-01-01

    A Pesca é uma atividade extrativa, expandindo-se nos tres setores da economia. No setor primário, quando considerado a atividade de captura do pescado. No secundário, quando considera-se a atividade de industrialização e, no terciário quando esta se reporta à exportação. A simulação da utilização do método ABC na indústria pesqueira do Estado do Ceará objetiva comparar o resultado desse método com o atualmente utilizado para fins de evidenciaçaõ de resultado. Fishing is an extra...

  15. UOP FIN 571 Final Exam Guide New

    OpenAIRE

    ADMIN

    2018-01-01

    UOP FIN 571 Final Exam Guide New Check this A+ tutorial guideline at http://www.fin571assignment.com/fin-571-uop/fin-571-final-exam-guide -latest For more classes visit http://www.fin571assignment.com Question 1 The underlying assumption of the dividend growth model is that a stock is worth: A. An amount computed as the next annual dividend divided by the required rate of return. B. An amount computed as the next annual dividend divided by the ma...

  16. Course design, action research and the use of computers: challanges in an ESP course Desenho de curso, pesquisa-ação e o uso do computador: desafios num curso de línguas para fins específicos

    Directory of Open Access Journals (Sweden)

    Silvia Matravolgyi Damião

    2011-01-01

    Full Text Available This paper presents the results of an action research project that focused on the design and teaching of an ESP course and on the collaborative construction and development of a website. In the first year of the study, the course plan was modified due to the feedback given by the students and the same happened to the site, which was uploaded and modified according to the students' productions within the period. The course plan was reformulated in the second year of the study based on the experience acquired in the first year, and tasks were introduced to fulfill the students' academic and future professional needs. At the end of the second year of the study, it was possible to confirm that the course plan, with the modifications that were introduced, was adequate, and that the site reflected the tasks prepared by the students within the period, therefore reaching the objectives proposed at the beginning of the study. It was also possible to propose new directions for ESP teaching at the Institution where the research was carried out.Este artigo descreve os resultados de uma pesquisa-ação que teve como objetivos desenvolver e acompanhar um curso de linglês para fins específicose sua docência, bem como a construção e desenvolvimento de um website. No primeiro ano do trabalho, o plano de curso foi modificado, devido ao retorno dado pelos alunos e o mesmo aconteceu com o site, que foi sendo alimentado e modificado de acordo com as produções dos alunos no período. O plano de curso foi reformulado no segundo ano do estudo, com base na experiência adquirida no ano anterior, e tarefas foram introduzidas para ir ao encontro das necessidades acadêmicas e futuras necessidades profissionais dos alunos. Ao final do segundo ano da pesquisa, foi possível confirmar que o plano de curso, com as modificações implementadas, era adequado e que o site refletia as tarefas feitas pelos alunos durante o curso, confirmando-se, assim, os objetivos

  17. Determinantes sociales frente a estilos de vida en la diabetes mellitus de tipo 2 en Andalucía: ¿la dificultad para llegar a fin de mes o la obesidad? Social determinants vs. lifestyle in type 2 diabetes mellitus in Andalusia (Spain: difficulty in making ends meet or obesity?

    Directory of Open Access Journals (Sweden)

    Antonio Escolar Pujolar

    2009-10-01

    Full Text Available Objetivo: Valorar las relaciones de la dificultad para llegar a fin de mes con la obesidad y la diabetes mellitus de tipo 2 en Andalucía. Métodos: Estudio transversal basado en los datos de la Encuesta de Salud de Andalucía-2003. Cálculo de prevalencias y odds ratio (OR de tener diabetes mellitus de tipo 2 según variables de estilo de vida, y de obesidad y diabetes mellitus de tipo 2 según la dificultad autopercibida para llegar a fin de mes. Resultados: La OR ajustada por edad de tener diabetes mellitus de tipo 2 en personas obesas respecto a las de peso normal fue de 2,52 (intervalo de confianza del 95% [IC95%]:1,63-3,88 y de 2,13 (IC95%:1,28-3,54 en las mujeres y los hombres, respectivamente. El sedentarismo no se asoció con un riesgo significativo de diabetes mellitus de tipo 2 en ninguno de los dos sexos. Para las mujeres con mayor dificultad económica para llegar a fin de mes, respecto a las que tienen más facilidades, la OR de ser obesa, ajustada por edad y ejercicio físico, fue de 3,03 (IC95%:1,96-4,66, y la de diabetes mellitus de tipo 2, ajustada por edad, ejercicio físico e índice de masa corporal, fue de 2,55 (IC95%:1,28-5,10. En los hombres ninguna de las OR fue estadísticamente significativa. Conclusión: En las mujeres, las dificultades para llegar a fin de mes reflejan un contexto socioeconómico favorecedor de obesidad y de diabetes mellitus de tipo 2. Las desigualdades de clase social y género identificadas pueden contribuir a ampliar el actual marco explicativo de los determinantes de la diabetes mellitus de tipo 2, excesivamente centrado en las conductas individuales. La dificultad autopercibida para llegar a fin de mes podría utilizarse como indicador de pobreza en los estudios de desigualdades en salud.Objective: To assess the relationship between difficulty in making ends meet and obesity and type 2 diabetes mellitus in Andalusia. Methods: We performed a cross-sectional survey based on the Andalusian Health

  18. Avaliação de Métodos de Estimativa da Evapotranspiração de Referência para Fins de Manejo da Irrigação

    Directory of Open Access Journals (Sweden)

    Célia Maria Paiva

    2016-01-01

    Full Text Available O conhecimento da evapotranspiração das culturas é muito importante para o manejo da irrigação. A equação FAO56 Penman-Monteith tem sido recomendada pela FAO (Food and Agriculture Organization of the United Nations como método padrão para a estimativa da evapotranspiração de referência (ETo . Entretanto, esse método requer variáveis meteorológicas que em geral não são medidas nas estações meteorológicas no Brasil. Por isso, o objetivo deste estudo foi avaliar cinco métodos empíricos e comparar seus desempenhos com o de Penman-Monteith para as condições climáticas da região de Piraí do Sul no Estado do Paraná. Para tanto, foram utilizados dados meteorológicos registrados por uma plataforma de coleta de dados durante o período de 04/07/2008 a 12/10/2008 em uma cultura de trigo. Os resultados indicam que a ETo pode ser estimada adequadamente pelos métodos da Radiação Solar, Jensen-Haise e Makkink. O pior desempenho foi apresentado pelo método de Hargreaves-Samani, seguido do método de Camargo.

  19. Numerical Analysis of Aerodynamic Characteristics of the Finned Surfaces with Cross-inclined Fins

    Directory of Open Access Journals (Sweden)

    Lagutin A. E.

    2016-12-01

    Full Text Available This paper presents results of numerical research and analyses air-side hydraulic performance of tube bundles with cross inclined fins. The numerical simulation of the fin-tube heat exchanger was performed using the Comsol Femlab software. The results of modeling show the influence of fin inclination angle and tube pitch on hydraulic characteristics of finned surfaces. A series of numerical tests were carried out for tube bundles with different inclination angles (γ =900, 850, 650, 60, the fin pitch u=4 mm. The results indicate that tube bundles with cross inclined fins can significantly enhance the average integral value of the air flow rate in channel between fins in comparison with conventional straight fins. Aerodynamic processes on both sides of modificated channel between inclined fins were analyzed. The verification procedures for received results of numerical modeling with experimental data were performed.

  20. A biorobotic model of the sunfish pectoral fin for investigations of fin sensorimotor control

    International Nuclear Information System (INIS)

    Phelan, Chris; Tangorra, James; Lauder, George; Hale, Melina

    2010-01-01

    A comprehensive understanding of the control of flexible fins is fundamental to engineering underwater vehicles that perform like fish, since it is the fins that produce forces which control the fish's motion. However, little is known about the fin's sensory system or about how fish use sensory information to modulate the fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish pectoral fin, a biorobotic model of the pectoral fin and of the fin's sensorimotor system was developed and used to investigate relationships between sensory information, fin ray motions and propulsive forces. This robotic fin is able to generate the motions and forces of the biological fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the pectoral fin. Results support the idea that fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of fin ray motion will result from the integration of characteristics of many sensor modalities.

  1. A biorobotic model of the sunfish pectoral fin for investigations of fin sensorimotor control

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, Chris; Tangorra, James [Department of Mechanical Engineering, Drexel University, Philadelphia, PA 19104 (United States); Lauder, George [Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138 (United States); Hale, Melina, E-mail: tangorra@coe.drexel.ed [Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637 (United States)

    2010-09-15

    A comprehensive understanding of the control of flexible fins is fundamental to engineering underwater vehicles that perform like fish, since it is the fins that produce forces which control the fish's motion. However, little is known about the fin's sensory system or about how fish use sensory information to modulate the fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish pectoral fin, a biorobotic model of the pectoral fin and of the fin's sensorimotor system was developed and used to investigate relationships between sensory information, fin ray motions and propulsive forces. This robotic fin is able to generate the motions and forces of the biological fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the pectoral fin. Results support the idea that fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of fin ray motion will result from the integration of characteristics of many sensor modalities.

  2. FinTech到RegTech

    Institute of Scientific and Technical Information of China (English)

    孙国峰[1,2

    2017-01-01

    本文分析FinTech(金融科技)监管的必要性,并介绍了FinTech监管的国际经验,在此基础上提出了我国可以探索将人工智能应用于金融监管,即以RegTech(监管科技)应对FinTech的建议。

  3. Frost behavior of a fin surface with temperature variation along heat exchanger fins

    International Nuclear Information System (INIS)

    Kim, Jung Soo; Kim, Min Soo; Lee, Kwan Soo; Kim, Ook Joong

    2007-01-01

    This paper presents a mathematical model for predicting the frost behavior formed on heat exchanger fins, considering fin heat conduction under frosting condition. The model is composed of air-side, the frost layer, and fin region, and they are coupled to the frost layer. The frost behavior is more accurately predicted with fin heat conduction considered (Case A) than with a constant fin surface temperature assumed (Case B). The results indicate that the frost thickness and heat transfer rate for Case B are over-predicted in most regions of the fin, as compared to those for Case A. Also, for Case A, the maximum frost thickness varies little with the fin length variations, and the extension of the fin length over 30 mm contributes insignificantly to heat transfer

  4. Los mecanismos de satisfacción extraprocesal o carencia sobrevenida del objeto, y la enervación del desahucio, para poner fin al proceso de forma anticipada

    Directory of Open Access Journals (Sweden)

    Susana San Cristóbal Reales

    2012-01-01

    Full Text Available La liberalización del sector ferroviario de mercancías está resultando un proceso lento y costoso no sólo en nuestro país sino en el conjunto de los países europeos. No obstante, en los últimos meses se han adoptado importantes decisiones estratégicas que redundarán en un impulso notable para la consecución de los objetivos que sobre esta política se marcaron hace tiempo desde el ámbito del Derecho Comunitario Europeo con la aprobación de las Directivas integrantes de los tres paquetes ferroviarios. Dicho objetivo consiste en elevar sustancialmente el volumen de las mercancías desplazadas por ferrocarril en el conjunto de los países miembros como medio de transporte más ecológico, eficiente y conveniente para descongestionar el transporte de mercancías por carretera sin que ello suponga la desaparición de éste sino su complementariedad mediante una ecuación de sinergias a través de la intermodalidad.

  5. Aluminum fin-stock alloys

    International Nuclear Information System (INIS)

    Gul, R.M.; Mutasher, F.

    2007-01-01

    Aluminum alloys have long been used in the production of heat exchanger fins. The comparative properties of the different alloys used for this purpose has not been an issue in the past, because of the significant thickness of the finstock material. However, in order to make fins lighter in weight, there is a growing demand for thinner finstock materials, which has emphasized the need for improved mechanical properties, thermal conductivity and corrosion resistance. The objective of this project is to determine the effect of iron, silicon and manganese percentage increment on the required mechanical properties for this application by analyzing four different aluminum alloys. The four selected aluminum alloys are 1100, 8011, 8079 and 8150, which are wrought non-heat treatable alloys with different amount of the above elements. Aluminum alloy 1100 serve as a control specimen, as it is commercially pure aluminum. The study also reports the effect of different annealing cycles on the mechanical properties of the selected alloys. Metallographic examination was also preformed to study the effect of annealing on the precipitate phases and the distribution of these phases for each alloy. The microstructure analysis of the aluminum alloys studied indicates that the precipitated phase in the case of aluminum alloys 1100 and 8079 is beta-FeAI3, while in 8011 it is a-alfa AIFeSi, and the aluminum alloy 8150 contains AI6(Mn,Fe) phase. The comparison of aluminum alloys 8011 and 8079 with aluminum alloy 1100 show that the addition of iron and silicon improves the percent elongation and reduces strength. The manganese addition increases the stability of mechanical properties along the annealing range as shown by the comparison of aluminum alloy 8150 with aluminum alloy 1100. Alloy 8150 show superior properties over the other alloys due to the reaction of iron and manganese, resulting in a preferable response to thermal treatment and improved mechanical properties. (author)

  6. Viabilidade do aproveitamento de resíduos de fibras vegetais para fins de obtenção de material de construção Suitability of vegetable fiber residues as construction material

    Directory of Open Access Journals (Sweden)

    Holmer Savastano Junior

    2000-04-01

    Full Text Available O presente estudo abordou a existência e as principais características de vinte resíduos de fibras vegetais, resultantes de processos agroindustriais, voltados para a obtenção de oito diferentes tipos de fibras comerciais. Com base em critérios de seleção inicialmente estabelecidos, foram identificados seis resíduos de maior interesse. Os resultados indicaram a potencialidade do seu emprego, no reforço de matrizes frágeis, à base de cimento Portland, para aumento de sua ductilidade. Telhas produzidas a partir de compósitos reforçados com fibras residuais de sisal "baler twine", coco, polpa de eucalipto, malva e banana, além de combinação entre fibras de coco e polpa de eucalipto, resistiram a cargas na flexão, superiores a 680 N, em conformidade com especificações internacionais.Twenty vegetable fiber by-products from agro-industrial production of eight different commercial fibers were analyzed in this study. Based on previously established selection criteria, six main types of residue were identified. Results showed that the selected by-products may be used as reinforcement of fragile cementitious matrices, for ductility improvement. Tiles produced with composites reinforced by residual fibers of sisal baler twine, coir, eucalyptus pulp, malva, banana, or a mixture of coir fibers and eucalyptus pulp, supported flexural loads in excess of 680N in keeping with international specifications.

  7. Investigation of internally finned LED heat sinks

    Science.gov (United States)

    Li, Bin; Xiong, Lun; Lai, Chuan; Tang, Yumei

    2018-03-01

    A novel heat sink is proposed, which is composed of a perforated cylinder and internally arranged fins. Numerical studies are performed on the natural convection heat transfer from internally finned heat sinks; experimental studies are carried out to validate the numerical results. To compare the thermal performances of internally finned heat sinks and externally finned heat sinks, the effects of the overall diameter, overall height, and installation direction on maximum temperature, air flow and heat transfer coefficient are investigated. The results demonstrate that internally finned heat sinks show better thermal performance than externally finned heat sinks; the maximum temperature of internally finned heat sinks decreases by up to 20% compared with the externally finned heat sinks. The existence of a perforated cylinder and the installation direction of the heat sink affect the thermal performance significantly; it is shown that the heat transfer coefficient of the heat sink with the perforated cylinder is improved greater than that with the imperforated cylinder by up to 34%, while reducing the mass of the heat sink by up to 13%. Project supported by the Scientific Research Fund of Sichuan Provincial Education Department (No. 18ZB0516) and the Sichuan University of Arts and Science (No. 2016KZ009Y).

  8. El fin de la tierra

    OpenAIRE

    Benitez Peña, Frank

    2014-01-01

    Ana Faura, una representante de una asociación de desplazados, desea recuperar la tierra que le fue arrebatada para enterrar allí los restos óseos de su esposo asesinado y volver a una vida que añora. En su propósito deberá enfrentarse no solo a amenazas de muerte en contra suya y de su único hijo sino a la necesidad de perdonar a los victimarios para lograr un verdadero retorno.

  9. Flow and Mass Transfer Performance in Short Pin-Fin Channels with Different Fin Shapes

    OpenAIRE

    Goldstein, R. J.; Chen, S. B.

    1998-01-01

    The mass transfer (analogous to heat transfer) and pressure loss characteristics of staggered short pin-fin arrays are investigated experimentally in the range of Reynolds number 3000 to 18,000 based on fin diameter and mean approach-flow velocity. Three different shapes of fins with aspect ratio of 2 are examined: one uniform-diameter circular fin (UDCF) and two stepped-diameter circular fins (SDCF1 and SDCF2). Flow visualization using oil-lampblack reveals complex flow characteristics assoc...

  10. The use of hydraulic bolts for coupling in order to shorten the maintenance critical path in turbo generator sites; Uso de tornillos hidraulicos para acoplamiento a fin de acortar la ruta critica del mantenimiento en sitios de turbogeneradores

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Arelle, Carlos [Turbomaquinas S. A. de C.V., La Piedad, Michoacan (Mexico)

    2007-11-15

    The use of hydraulic bolts has permitted to diminish the time in the critical path of the maintenance, attaining to reduce the total costs and avoiding that some bolts are stuck, benefits the on time planning of the maintenance. The bolts of radial adjustment provide significant benefits to the General Turbine operator. The hydraulic bolts avoid the normal problems of the conventional coupling bolts and rapidly help to re-establish the couple concentricity. The bolts are individually designed to meet a specific geometry and are a direct replacement of the conventional bolts. [Spanish] El uso de tornillos hidraulicos ha permitido disminuir el tiempo de la ruta critica del mantenimiento, logrando reducir los costos totales y al evitar que algun tornillo se atore, beneficia la planeacion de mantenimientos a tiempo. Los tornillos de ajuste radial proveen beneficios significativos al operador de la Turbina General. Los tornillos hidraulicos eliminan los problemas normales de los tornillos de acoplamiento convencionales y rapidamente ayudan a restablecer la concentridad del cople. Los tornillos son disenados individualmente para completar una geometria especifica y son un reemplazo directo de los tornillos convencionales.

  11. Avaliação da degradação térmica e fotooxidativa do ABS para fins de reciclagem Evaluation of thermal and photo-oxidative ABS degradation with recycling purposes

    Directory of Open Access Journals (Sweden)

    Elisabete Maria Saraiva Sanchez

    2003-07-01

    Full Text Available Este trabalho tem como objetivo avaliar a degradação térmica e fotooxidativa do terpolímero poli (acrilonitrila-butadieno-estireno, ABS, utilizado em componentes internos de automóveis. Corpos de prova de ABS moldados por injeção foram submetidos ao envelhecimento térmico, segundo a norma ASTM D794, e ao envelhecimento fotooxidativo segundo as normas ASTM G24 e G53. As amostras envelhecidas foram submetidas às análises dinâmico-mecânica, e microscópicas por microscopia de força atômica no modo não contato. Os resultados mostraram que as transições, tanto da fase vítrea quanto da fase elastomérica na superfície do ABS, são afetadas pela degradação. As áreas dos picos das curvas de módulo de perda em função da temperatura relativos às transições vítreas do ABS foram correlacionadas ao alongamento na ruptura, em função do tempo e tipo de envelhecimento. As propriedades mecânicas são influenciadas de forma mais acentuada pela extensão da degradação da matriz. O método de envelhecimento ASTM G24 mostrou-se mais agressivo que o G53, seja para a fase BR ou para a fase SAN. As imagens microscópicas mostraram que os diferentes envelhecimentos provocaram diferentes variações na rugosidade das superfícies. Amostras fotooxidadas, com perda de alongamento maior que 50%, foram reprocessadas e mostraram uma recuperação superior a 90% nessa propriedade.The aim of this work is the evaluation of thermal and photo-oxidative degradation of the terpolymer acrylonitrile-butadiene-styrene, ABS, used in internal automotive components. Injection molded specimens were aged by ASTM D794, ASTM G24 and ASTM G53 standards. The aged test specimens were studied by means of dynamic mechanical analysis and non-contact atomic force microscopy. The results revealed that the transitions of the glass and rubber phases were affected by the degradation. The area under linear loss modulus-temperature curves was related to tensile properties

  12. Um método simplificado de fusão de imagens para fins de interpretação visual = A simplified merging method applied to image data for purposes of visual interpretation

    Directory of Open Access Journals (Sweden)

    Selma Regina Aranha Ribeiro

    2009-01-01

    Full Text Available A fusão de imagens é um tema que desperta interesse pela coleta de imagens multiespectrais e pancromáticas com diferentes resoluções espaciais e espectrais. O método de fusão ganhou grande reconhecimento quando imagens Landsat multiespectrais puderamser combinadas com imagens SPOT pancromáticas. Esse processo comprovou ser útil na geração de imagens híbridas que combinam as propriedades das imagens originais numa única nova imagem, que preserva a informação espectral e possui melhor informaçãoespacial. O resultado é uma nova imagem com maior resolução espacial e preservação da maior resolução espectral. Este documento apresenta o método I1I2I3, introduzido por Ohta et al. (1980, como uma opção de fusão por substituição em relação ao método RGBIHS. Para aplicar o método I1I2I3 e o RGB-IHS, duas imagens de altas resoluções foramutilizadas, Ikonos II e Quickbird.Image merging is a topic that has drawn new interest due to theacquirement of multispectral and panchromatic images with different resolutions. The merging approach received great recognition when multispectral Landsat images were matched with panchromatic SPOT images. This process proved to be useful for generating hybrid images that combine properties from the originals into a new unique image, still maintaining spectral information and featuring improved spatial information. The result is a new image with better spatial and preserved spectral resolution. This paper presents the I1I2I3 merging method, introduced by Ohta et al. (1980, as an option for image merging through substitution in relation to the RGB-HSI method. In order to apply the I1I2I3 and RGB-HIS methods, two high resolution images were utilized, Ikonos II and Quickbird.

  13. Fin shape thermal optimization using Bejan's constuctal theory

    CERN Document Server

    Lorenzini, Giulio

    2011-01-01

    The book contains research results obtained by applying Bejan's Constructal Theory to the study and therefore the optimization of fins, focusing on T-shaped and Y-shaped ones. Heat transfer from finned surfaces is an example of combined heat transfer natural or forced convection on the external parts of the fin, and conducting along the fin. Fin's heat exchange is rather complex, because of variation of both temperature along the fin and convective heat transfer coefficient. Furthermore possible presence of more fins invested by the same fluid flow has to be considered.Classical fin theory tri

  14. Performance study of a fin and tube heat exchanger with different fin geometry

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2016-01-01

    This study analyses the effect of different fin geometries on the heat transfer and pressure loss characteristics of a fin and tube heat exchanger. A numerical investigation is carried out on liquid–gas type double-finned tube heat exchanger under cross-flow condition. Three different cross......-sections namely: a) Rectangular, b) Trapezoidal, c) Triangular are adopted to define the fin geometry. The CFD simulations are performed to incorporate coupled steady state conjugate heat transfer with the turbulent flow phenomenon for the Reynolds number in the range of 5000-13000. Dimensionless heat transfer...... models show that triangular fin geometry can provide higher heat transfer performance in comparison to the fins with rectangular and trapezoidal geometry with lower pressure loss and a bonus of 7.27% reduction in weight under similar operating conditions....

  15. Thermal transport in oblique finned microminichannels

    CERN Document Server

    Fan, Yan; Singh, Pawan Kumar; Lee, Yong Jiun

    2015-01-01

    The main aim of this book is to introduce and give an overview of a novel, easy, and highly effective heat transfer augmentation technique for single-phase micro/minichannel heat sink. The specific objectives of the volume are to: Introduce a novel planar oblique fin microchannel and cylindrical oblique fin minichannel heat sink design using passive heat transfer enhancement techniques  Investigate the thermal transport in both planar and cylindrical oblique fin structures through numerical simulation and systematic experimental studies. Evaluate the feasibility of employing the proposed solution in cooling non-uniform heat fluxes and hotspot suppression Conduct the similarity analysis and parametric study to obtain empirical correlations to evaluate the total heat transfer rate of the oblique fin heat sink Investigate the flow mechanism and optimize the dimensions of cylindrical oblique fin heat sink Investigate the influence of edge effect on flow and temperature uniformity in these oblique fin chan...

  16. Realización de un repositorio de Tesis doctorales y Trabajos Fin de Grado con DRUPAL

    OpenAIRE

    Orenes Cayuelas, Tomás

    2012-01-01

    Trabajo fin de grado que pretende la creación de un repositorio de tesis doctorales y trabajos fin de grado para la facultad de Comunicación de la universidad de Murcia. Existe el objetivo a su vez de observar los problemas que puedan surgir al crear el repositorio con un gestor de contenidos cuyo propósito final no es este. Pa...

  17. Studi Analitik dan Numerik Perpindahan Panas pada Fin Trapesium (Studi Kasus pada Finned Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Ahmad Zaini

    2013-09-01

    Full Text Available Penambahan fin pada pipa penukar kalor merupakan suatu upaya memperbesar perpindahan kalor konduksi dan konveksi, dengan cara memperluas bidang geometri. Pada penelitian ini dianalisa secara analitik dan numerik perpindahan kalor pada fin dengan profil longitudinal tidak seragam atau berubah terhadap jarak dari dasar fin, dengan memvariasikan ketebalan ujung fin. Hasil dari kedua studi ini tidak jauh berbeda, pada keduanya menjelaskan bahwa fin dengan ketebalan ujung 0,9 mm (fin trapesium terbalik paling baik dari 5 variasi lainnya; serta perubahan temperatur paling besar terjadi pada sepertiga pertama dari panjang  fin, ini artinya pelepasan kalor terbesar terjadi pada daerah tersebut. Perbedaannya adalah pada persentase penurunan temperatur sepanjang  fin terhadap temperatur dasar fin, untuk ketebalan 0,9 mm pada studi analitik sebesar 91,92% dan pada studi numerik sebesar 91,78%. Hal ini berarti metode penyelesaian persamaan diferensial orde 2 dengan koefisien variabel dengan cara pembedahan koefisien variabel pada ODE, sudah benar dan valid. Namun bila ditinjau dari waktu yang diperlukan untuk komputasinya, studi analitik membutuhkan waktu lebih lama. Waktu yang diperlukan dalam komputasinya tergantung dari fungsi koefisien variabel.

  18. Avaliação de cultivares de soja, sob manejo orgânico, para fins de adubação verde e produção de grãos Evaluation of soybean cultivars under organic management for green manuring and grain production

    Directory of Open Access Journals (Sweden)

    Milton Parron Padovan

    2002-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o desempenho de seis cultivares de soja, sob manejo orgânico, para fins de adubação verde e produção de grãos. Utilizou-se delineamento experimental de blocos casualizados, com quatro repetições por tratamento (cultivar. Na época da colheita, 81 dias após a emergência das plântulas, todas as cultivares testadas (Celeste, Surubi, Campo Grande, Mandi, Lambari e Taquari mostraram excelente nodulação, variando de 545 a 760 mg/planta de massa nodular seca. As cultivares Celeste e Taquari, que produziram, respectivamente, 8,33 e 7,12 t ha-1 de biomassa seca da parte aérea, apresentaram outras características agronômicas vantajosas, tais como: ciclo curto, alta acumulação de nutrientes (N, P, K, Ca e Mg nos tecidos verdes e bom rendimento de sementes. Esses caracteres indicam potencial de 'Celeste' e 'Taquari' para adubação verde de verão em sistemas de agricultura orgânica. Cinco das cultivares avaliadas revelaram tendência ao acamamento, porém dentro de níveis aceitáveis. As cultivares Celeste, Surubi, Campo Grande, Mandi e Taquari suplantaram em 23%, 32%, 33%, 44% e 70%, respectivamente, a média nacional de produtividade de soja, estimada em 2.398 kg ha-1 nas últimas três safras.The objective of this work was to evaluate the grain and aboveground biomass production of six soybean cultivars under organic management. A randomized block design was adopted with four replications per treatment (cultivar. By harvest time, 81 days after plants emergence, all tested cultivars (Celeste, Surubi, Campo Grande, Mandi, Lambari, and Taquari had excellent nodulation ranging from 545 to 760 mg/plant of nodule mass (dry weight. The cultivars Celeste and Taquari, which yielded 8.33 and 7.12 t ha-1 of dry biomass, respectively, showed other advantageous agronomic characteristics such as: short cycle, a high accumulation of nutrients (N, P, K, Ca and Mg in green tissues, and good seed setting. These

  19. A Biologically Derived Pectoral Fin for Yaw Turn Manoeuvres

    Directory of Open Access Journals (Sweden)

    Jonah R. Gottlieb

    2010-01-01

    Full Text Available A bio-robotic fin has been developed that models the pectoral fin of the bluegill sunfish as the fish turned to avoid an obstacle. This work involved biological studies of the sunfish fin, the development of kinematic models of the motions of the fin's rays, CFD based predictions of the 3D forces and flows created by the fin, and the implementation of simplified models of the fin's kinematics and mechanical properties in a physical model. The resulting robotic fin produced the forces and flows that drove the manoeuvre and had a sufficiently high number of degrees of freedom to create a variety of non-biologically derived motions. The results indicate that for robotic fins to produce a level of performance on par with biological fins, both the kinematics and the mechanical properties of the biological fin must be modelled well.

  20. Role of Pectoral Fin Flexibility in Robotic Fish Performance

    Science.gov (United States)

    Bazaz Behbahani, Sanaz; Tan, Xiaobo

    2017-08-01

    Pectoral fins play a vital role in the maneuvering and locomotion of fish, and they have become an important actuation mechanism for robotic fish. In this paper, we explore the effect of flexibility of robotic fish pectoral fins on the robot locomotion performance and mechanical efficiency. A dynamic model for the robotic fish is presented, where the flexible fin is modeled as multiple rigid elements connected via torsional springs and dampers. Blade element theory is used to capture the hydrodynamic force on the fin. The model is validated with experimental results obtained on a robotic fish prototype, equipped with 3D-printed fins of different flexibility. The model is then used to analyze the impacts of fin flexibility and power/recovery stroke speed ratio on the robot swimming speed and mechanical efficiency. It is found that, in general, flexible fins demonstrate advantages over rigid fins in speed and efficiency at relatively low fin-beat frequencies, while rigid fins outperform flexible fins at higher frequencies. For a given fin flexibility, the optimal frequency for speed performance differs from the optimal frequency for mechanical efficiency. In addition, for any given fin, there is an optimal power/recovery stroke speed ratio, typically in the range of 2-3, that maximizes the speed performance. Overall, the presented model offers a promising tool for fin flexibility and gait design, to achieve speed and efficiency objectives for robotic fish actuated with pectoral fins.

  1. Methylmercury in dried shark fins and shark fin soup from American restaurants.

    Science.gov (United States)

    Nalluri, Deepthi; Baumann, Zofia; Abercrombie, Debra L; Chapman, Demian D; Hammerschmidt, Chad R; Fisher, Nicholas S

    2014-10-15

    Consumption of meat from large predatory sharks exposes human consumers to high levels of toxic monomethylmercury (MMHg). There also have been claims that shark fins, and hence the Asian delicacy shark fin soup, contain harmful levels of neurotoxic chemicals in combination with MMHg, although concentrations of MMHg in shark fins are unknown. We measured MMHg in dried, unprocessed fins (n=50) of 13 shark species that occur in the international trade of dried shark fins as well as 50 samples of shark fin soup prepared by restaurants from around the United States. Concentrations of MMHg in fins ranged from 9 to 1720 ng/g dry wt. MMHg in shark fin soup ranged from sharks such as hammerheads (Sphyrna spp.). Consumption of a 240 mL bowl of shark fin soup containing the average concentration of MMHg (4.6 ng/mL) would result in a dose of 1.1 μg MMHg, which is 16% of the U.S. EPA's reference dose (0.1 μg MMHg per 1 kg per day in adults) of 7.4 μg per day for a 74 kg person. If consumed, the soup containing the highest measured MMHg concentration would exceed the reference dose by 17%. While shark fin soup represents a potentially important source of MMHg to human consumers, other seafood products, particularly the flesh of apex marine predators, contain much higher MMHg concentrations and can result in substantially greater exposures of this contaminant for people. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Thermoelectric generator with hinged assembly for fins

    International Nuclear Information System (INIS)

    Purdy, D.L.; Shapiro, Z.M.; Hursen, T.F.; Maurer, G.W.

    1976-01-01

    A cylindrical casing has a central shielded capsule of radioisotope fuel. A plurality of thermonuclear modules are axially arranged with their hot junctions resiliently pressed toward the shield and with their cold junctions adjacent a transition member having fins radiating heat to the environment. For each module, the assembly of transition member and fins is hinged to the casing for swinging to permit access to and removal of such module. A ceramic plate having gold layers on opposite faces prevents diffusion bonding of the hot junction to the shield

  3. Vortex Shedding from Finned Circular Cylinders

    Science.gov (United States)

    1980-11-01

    FINNED CIRCULAR CYLINDERSo ,rm"" 1..UTNOI .)R*., r. *.040, 111SPOR- / T NuMBII f.John G. elute asOHans J.’/, ugt -. . . , ,<-. -. ,:. =., .. Siil P3RPIO...fins and other sharp protuberances. These purely two-dimensional flows then may be used in a strip theory to include at least some aspects of three...boundary- layer theory . Such a prediction method, together with a technique to provide for a vortex sheet at the separation point, will be included in

  4. Effects of ultra-thin Si-fin body widths upon SOI PMOS FinFETs

    Science.gov (United States)

    Liaw, Yue-Gie; Chen, Chii-Wen; Liao, Wen-Shiang; Wang, Mu-Chun; Zou, Xuecheng

    2018-05-01

    Nano-node tri-gate FinFET devices have been developed after integrating a 14 Å nitrided gate oxide upon the silicon-on-insulator (SOI) wafers established on an advanced CMOS logic platform. These vertical double gate (FinFET) devices with ultra-thin silicon fin (Si-fin) widths ranging from 27 nm to 17 nm and gate length down to 30 nm have been successfully developed with a 193 nm scanner lithography tool. Combining the cobalt fully silicidation and the CESL strain technology beneficial for PMOS FinFETs was incorporated into this work. Detailed analyses of Id-Vg characteristics, threshold voltage (Vt), and drain-induced barrier lowering (DIBL) illustrate that the thinnest 17 nm Si-fin width FinFET exhibits the best gate controllability due to its better suppression of short channel effect (SCE). However, higher source/drain resistance (RSD), channel mobility degradation due to dry etch steps, or “current crowding effect” will slightly limit its transconductance (Gm) and drive current.

  5. Performance of tubes-and plate fins heat exchangers

    International Nuclear Information System (INIS)

    Rosman, E.C.

    1979-11-01

    By means of a two-dimensional analysis performance, and using local heat transfer coefficients, the plate fin temperature distribution, the air bulk temperature along the stream path and the fin efficiency can be obtained, for several Reynolds numbers and fin materials. Herein are also presented the average heat transfer coefficients for isothermal plate fins, referring to heat exchangers with central-tube and rear-tube row and to two-row tubes heat exchangers configurations. It is possible to obtain the real tax or the real area of heat transfer, using the average hea transfer coefficients for isothermal plate fins and the fin efficiency. (Author) [pt

  6. Classificação tecnológica de solos e resíduos industriais, com e sem tratamento térmico, para fins rodoviários Technological classification of soils and industrial residues with and without thermal treatment for forest road pavement

    Directory of Open Access Journals (Sweden)

    Carlos Cardoso Machado

    2003-10-01

    Full Text Available Estudou-se o comportamento mecânico das misturas solo-alcatrão, solo-cal-alcatrão e solo-cimento-alcatrão, com base nos ensaios de limites de liquidez e plasticidade, CBR, compressão simples e permeabilidade, visando a aplicabilidade destas em rodovias. Trabalhou-se com três amostras de solos (ETA, NV e VS, representativos das ocorrências da microrregião de Viçosa-MG. Foram empregados alcatrão, nos quantitativos de 0,25, 0,5, 1, 2, 4 e 6%, cal hidratada e cimento Portland, em conjunto com o alcatrão, na dosagem de 2%, considerando-se a energia do ensaio de compactação AASHTO Normal. A adição de alcatrão reduziu significativamente os valores de LL dos solos, mas com pouca variação nos valores de IP. Conclui-se que o alcatrão contribuiu para melhorar as características mecânicas e hidráulicas dos solos, para alguns tratamentos, não atingindo, entretanto, os padrões de resistência mecânica exigida pelo DNER para camadas de sub-base de pavimentos flexíveis. Quanto às misturas solo-cal-alcatrão e solo-cimento-alcatrão, constatou-se melhoria substancial nos parâmetros de resistência mecânica em relação aos solos, principalmente devido à ação cimentante da cal e do cimento, e que para alguns tratamentos esta ação foi potencializada pelo alcatrão, incidindo em resistência mecânica superior à das misturas solo-cal e solo-cimento. O alcatrão, em alguns tratamentos, ocasionou decréscimos na permeabilidade das misturas, com relação ao solo, de até dez vezes. O alcatrão mostrou ser um estabilizante de interesse para fins rodoviários apenas para determinadas condições, envolvendo tipo de solo e tipo e teor de alcatrão, o que indica que estudos nesta direção devem apresentar uma característica regional.The behavior of the mechanical mixtures soil-wood tar, soil-lime-wood tar and soil-cement-wood tar, based on the Atterberg limits California Bearing Ratio (CBR, Unconfined Compression Strength (UCS and

  7. On the Hydrodynamics of Anomalocaris Tail Fins.

    Science.gov (United States)

    Sheppard, K A; Rival, D E; Caron, J-B

    2018-04-25

    Anomalocaris canadensis, a soft-bodied stem-group arthropod from the Burgess Shale, is considered the largest predator of the Cambrian period. Thanks to a series of lateral flexible lobes along its dorso-ventrally compressed body, it is generally regarded as an efficient swimmer, well-adapted to its predatory lifestyle. Previous theoretical hydrodynamic simulations have suggested a possible optimum in swimming performance when the lateral lobes performed as a single undulatory lateral fin, comparable to the pectoral fins in skates and rays. However, the role of the unusual fan-like tail of Anomalocaris has not been previously explored. Swimming efficiency and maneuverability deduced from direct hydrodynamic analysis are here studied in a towing tank facility using a three-vane physical model designed as an abstraction of the tail fin. Through direct force measurements, it was found that the model exhibited a region of steady-state lift and drag enhancement at angles of attack greater than 25° when compared to a triangular-shaped reference model. This would suggest that the resultant normal force on the tail fin of Anomalocaris made it well-suited for turning maneuvers, giving it the ability to turn quickly and through small radii of curvature. These results are consistent with an active predatory lifestyle, although detailed kinematic studies integrating the full organism, including the lateral lobes, would be required to test the effect of the tail fin on overall swimming performance. This study also highlights a possible example of evolutionary convergence between the tails of Anomalocaris and birds, which, in both cases, are well-adapted to efficient turning maneuvers.

  8. Advanced microchannel heat exchanger with S-shaped fins

    International Nuclear Information System (INIS)

    Tsuzuki, Nobuyoshi; Ishizuka, Takao; Kato, Yasuyoshi; Nikitin, Konstantin

    2009-01-01

    Fin shape effects on thermal-hydraulic characteristics were studied for a Microchannel Heat Exchanger (MCHE) with S-shaped fins using 3D-CFD and changing the fin parameters: fin angle, overlapping length, fin width, fin length, and edge roundness. The fin angle effect on the pressure drop is consistent with the equation obtained experimentally by Weisbach for a circular bent tube: the pressure drop in the S-shaped fin configuration results from bent flow. The overlap of fins with those located immediately downstream at the offset position provides a guide wing effect that reduces the pressure drop remarkably. The overlap was changed by changing the fin radial position and arc length. The pressure drop was minimized when the downstream fins are placed in the middle of the bent flow channels formed by the fins upstream, which differs from Ito's configuration obtained from experiments with a single bent duct. Regarding arc length, the pressure drop is minimized at the standard overlapping length, which was formed to have the longest arc without a change in channel width. Shorter arc lengths from the optimum value by 30 and 50%, respectively, give 2.4 and 4.6% decreases in the heat transfer rate and 17 and 13% increases in the pressure drop. Thinner fins show better thermal-hydraulic performance for fin widths of 0.2-0.8 mm. However, the pressure drop reduced by the longer fin and heat transfer rate was also reduced. Rounded fins with 0.1 mm radius increased the pressure drop by about 30% compared with that of the fin designed with no roundness. (author)

  9. FinTech in Norway : the effect of FinTech on the traditional Norwegian banking sector

    OpenAIRE

    Omreng, Stian; Gjendem, Ida

    2017-01-01

    The purpose of this thesis is to investigate the effect of FinTech on the Norwegian banking industry. We investigate the drivers of FinTech, the current and potential Norwegian FinTech market, and the international competitiveness of the Norwegian FinTech movement. We identify nine segments of FinTech within the traditional banking functions Financing, Asset management, Payments and Authentication, and we find the key drivers behind the rapid growth of the FinTech market as cha...

  10. Room to high temperature measurements of flexible SOI FinFETs with sub-20-nm fins

    KAUST Repository

    Diab, Amer El Hajj

    2014-12-01

    We report the temperature dependence of the core electrical parameters and transport characteristics of a flexible version of fin field-effect transistor (FinFET) on silicon-on-insulator (SOI) with sub-20-nm wide fins and high-k/metal gate-stacks. For the first time, we characterize them from room to high temperature (150 °C) to show the impact of temperature variation on drain current, gate leakage current, and transconductance. Variation of extracted parameters, such as low-field mobility, subthreshold swing, threshold voltage, and ON-OFF current characteristics, is reported too. Direct comparison is made to a rigid version of the SOI FinFETs. The mobility degradation with temperature is mainly caused by phonon scattering mechanism. The overall excellent devices performance at high temperature after release is outlined proving the suitability of truly high-performance flexible inorganic electronics with such advanced architecture.

  11. Desarrollo y aplicación de una metodología basada en las mejores prácticas de control de calidad, para aplicar en la implementación de un ERP para empresas del tipo pymes con el fin de reducir los factores de riesgo que afectan el tiempo y el costo de la implementación

    OpenAIRE

    Flores Proaño, Nicolás Andrés

    2015-01-01

    El crecimiento actual acelerado de la tecnología, ha permitido a las empresas crecer de la mano de esta, teniendo acceso a nuevas herramientas que facilitan sus operaciones del día a día. Dentro de las tareas más complejas y que mayor demanda de recursos genera para una empresa, está la gestión de todos sus recursos y su cotejamiento con el control financiero contable. Es por esta necesidad que aparecen los primeros sistemas contables, los cuales permitían a las empresas lle...

  12. Investigation of material efficient fin patterns for cost-effective operation of fin and tube heat exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2017-01-01

    Design management of a thermal energy system is a critical part of identifying basic designs that meet large scale user demand under certain operating characteristics. Fin and tube heat exchangers are among the most commonly used thermal energy systems which are generating considerable interest...... and tube heat exchanger. Computational fluid dynamic models of fin and tube heat exchanger with different fin patterns are developed to investigate the fin pattern behavior on heat transfer and pressure loss performance data. In addition, the numerical results are utilized to analyze the engineering design...... scale-up heat exchanger configurations with each fin pattern focusing on the application of chosen fin and tube heat exchanger in marine exhaust gas boiler. The analysis highlights the impact of material efficient fin patterns investigated and predicts that the polynomial and sinusoidal fin patterns...

  13. Nurturing a FinTech Ecosystem

    DEFF Research Database (Denmark)

    Leong, Carmen; Tan, Barney; Xiao, Xiao

    2017-01-01

    Financial technology, or FinTech, involves the design and delivery of financial products and services through technology. It impacts financial institutions, regulators, customers, and merchants across a wide range of industries. Pervasive digital technologies are challenging the fundamentals...... of the highly regulated financial sector, leading to the emergence of non-traditional payment systems, peer-to-peer money exchanges and increased turbulence in currency markets. This case study explores the development of a FinTech company in China that offers microloans to college students. Five lessons...... learned are presented for organizations to better manage the challenges and to leverage the opportunities amidst the disruption of financial sector. Our findings also shed light on how digital technology 1) offers the strategic capability for a firm to occupy a market niche in financial sector, 2) enables...

  14. Stability Criterion for a Finned Spinning Projectile

    OpenAIRE

    S. D. Naik

    2000-01-01

    The state-of-the-art in gun projectile technology has been used for the aerodynamic stabilisation.This approach is acceptable for guided and controlled rockets but the free-flight rockets suffer fromunacceptable dispersion. Sabot projectiles with both spin and fms developed during the last decadeneed careful analysis. In this study, the second method of Liapunov has been used to develop stability criterion for a projectile to be designed with small fins and is made to spin in the flight. This...

  15. An experimental investigation on the airside performance of fin-and-tube heat exchangers having slit fins under wet condition

    International Nuclear Information System (INIS)

    Kim, Nae Hyun; Kim, Tae Hun

    2015-01-01

    In this study, the heat transfer and friction characteristics of the 5.3 mm O.D. slit-finned heat exchangers under wet condition have been experimentally investigated. Plain-finned heat exchangers having the same 5.3 mm O.D. tubes are also tested for comparison purpose. The effect of fin pitch on j and f factor is negligible. Slit fin samples yield higher j and f factors than plain fin samples. For one row configuration, the average f factor ratio between slit fin sample and plain fin sample is 2.18. The ratio increases to 2.41 for two row configuration, and to 2.65 for three row configuration. As for the j factor, the ratios are approximately the same (1.61, 1.70 and 1.71 for one, two and three row configuration). Both j and f factor increase as the number of tube row decreases. The same trend is observed for the plain fin samples. At high Reynolds numbers, the j/f ratios of the slit fin are approximately the same as those of the plain fin. At low Reynolds numbers, the j/f ratios of the slit fin are smaller than those of plain fin. Data are compared with existing correlations.

  16. Effect of Using Extra Fins on the Pin Fin Classic Geometry for Enhancement Heat Sink Performance using EGM Method

    Directory of Open Access Journals (Sweden)

    Kadhum Audaa Jehhef

    2018-04-01

    Full Text Available In the present study, the effect of new cross-section fin geometries on overall thermal/fluid performance had been investigated. The cross-section included the base original geometry of (triangular, square, circular, and elliptical pin fins by adding exterior extra fins along the sides of the origin fins. The present extra fins include rectangular extra fin of 2 mm (height and 4 mm (width and triangular extra fin of 2 mm (base 4 mm (height. The use of entropy generation minimization method (EGM allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general dimensionless expression for the entropy generation rate is obtained by considering a control volume around the pin fin including a base plate and applying the conservations equations of mass and energy with the entropy balance. The dimensionless numbers used includes the aspect ratio (ε, Reynolds number (Re, Nusselt number (Nu, and the drag coefficients (CD. Fourteen different cross-section fin geometries are examined for the heat transfer, fluid friction, and the minimum entropy generation rate. The results showed that the Nusselt number increases with increasing the Reynolds number for all employed models. The ellipse models (ET and ER-models give the highest value in the Nusselt number as compared with the classical pin fins. The fin of the square geometry with four rectangular extra fins (SR-models gives an agreement in Nusselt number as compared with the previous study.

  17. A biorobotic pectoral fin for autonomous undersea vehicles.

    Science.gov (United States)

    Tangorra, James L; Davidson, S Naomi; Madden, Peter G; Lauder, George V; Hunter, Ian W

    2006-01-01

    A biorobotic fin for autonomous undersea vehicles (AUVs) was developed based on studies of the anatomy, kinematics, and hydrodynamics of the bluegill sunfish pectoral fin. The biorobotic fin was able to produce many of the complex fin motions used by the sunfish during steady swimming and was used to investigate mechanisms of thrust production and control. This biorobotic fin is an excellent experimental tool and is an important first step towards developing propulsive devices that give AUVs maneuvering characteristics that match and exceed those of highly maneuverable fish.

  18. The optimization of longitudinal convective fins with internal heat generation

    International Nuclear Information System (INIS)

    Razelos, P.

    1979-01-01

    The solution of the optimization problem for longitudinal convective fins of constant thickness, triangular or parabolic profile, and uniform internal heat generation, is presented. The cases considered are those of a given heat generation density, total heat generation and heat generation per unit width of the fin, when either the heat dissipation or the width of the fin is prescribed. The results are set forth in a nondimensional form, which are presented graphically. The effect of the fin's thermal conductivity upon the optimum dimensions is discussed, and limiting values for the heat generation and the heat dissipation, which may be imposed on the fin for a feasible optimization, are also obtained. (Auth.)

  19. Study of Swept Angle Effects on Grid Fins Aerodynamics Performance

    Science.gov (United States)

    Faza, G. A.; Fadillah, H.; Silitonga, F. Y.; Agoes Moelyadi, Mochamad

    2018-04-01

    Grid fin is an aerodynamic control surface that usually used on missiles and rockets. In the recent several years many researches have conducted to develop a more efficient grid fins. There are many possibilities of geometric combination could be done to improve aerodynamics characteristic of a grid fin. This paper will only discuss about the aerodynamics characteristics of grid fins compared by another grid fins with different swept angle. The methodology that used to compare the aerodynamics is Computational Fluid Dynamics (CFD). The result of this paper might be used for future studies to answer our former question or as a reference for related studies.

  20. Investigating the effect of non-similar fins in thermoeconomic optimization of plate fin heat exchanger

    International Nuclear Information System (INIS)

    Hajabdollahi, Hassan

    2015-01-01

    Thermoeconomic optimization of plate fin heat exchanger with similar (SF) and different (DF) or non-similar fin in each side is presented in this work. For this purpose, both heat exchanger effectiveness and total annual cost (TAC) are optimized simultaneously using multi-objective particle swarm optimization algorithm. The above procedure is performed for various mass flow rates in each side. The optimum results reveal that no thermoeconomic improvement is observed in the case of same mass flow rate in each side while both effectiveness and TAC are improved in the case of different mass flow rate. For example, effectiveness and TAC are improved 0.95% and 10.17% respectively, for the DF compared with SF. In fact, the fin configuration should be selected more compact in a side with lower mass flow rate compared with the other side in the thermoeconomic viewpoint. Furthermore, for the thermodynamic optimization viewpoint both SF and DF have the same optimum result while for the economic (or thermoeconomic) optimization viewpoint, the significant decrease in TAC is accessible in the case of DF compared with SF. - Highlights: • Thermoeconomic modeling of compact heat exchanger. • Selection of fin and heat exchanger geometries as nine decision variables. • Applying MOPSO algorithm for multi objective optimization. • Considering the similar and different fin specification in each side. • Investigation of optimum design parameters for various mass flow rates

  1. INSTRUMENTOS JURÍDICOS DO MDL–MECANISMO DE DESENVOLVIMENTO LIMPO–NA IMPLEMENTAÇÃO DE RESERVA LEGAL PARA FINS ENERGÉTICOS NO BRASIL/JURIDICAL INSTRUMENTS OF CDM–CLEAN DEVELOPMENT MECHANISM–IN THE IMPLEMENTATION OF LEGAL RESERVE ENERGETIC PURPOSES IN BRAZIL

    Directory of Open Access Journals (Sweden)

    Pedro Fernando CATANEO

    2012-11-01

    , mas sim, a toda a sociedade na qual o homem está incluído. A questão que se apresenta não é apenas de ordem jurídica, que encontra respaldo no direito positivo, mas sim, uma questão de sobrevivência, do homem, que hoje domina a Terra, assim como de todas as outras formas de vida, das quais ele é diretamente dependente. O Código Florestal brasileiro estabelece Reserva Legal como a área localizada no interior de uma propriedade rural, excetuada a de Preservação Permanente, necessária ao uso sustentável dos recursos naturais, à conservação e reabilitação dos processos ecológicos, à conservação da biodiversidade e ao abrigo e proteção de fauna e flora nativas. A Reserva Legal, nas proporções estabelecidas em Lei, tem importante função nesse processo climático. Atualmente áreas destinadas e averbadas como Reserva Legal são ínfimas, mas, apesar dos altos custos decorrentes, poderiam ser maiores, caso os proprietários rurais fossem sensibilizados quanto aos benefícios coletivos de sua implantação. Propõe-se neste trabalho a implantação de áreas de Reserva Legal, com financiamentos e incentivos, através de instrumentos jurídicos e políticos do Mecanismo de Desenvolvimento Limpo, de forma a promover o desenvolvimento sustentável da propriedade, a geração e/ou manutenção da renda dos produtores, tanto pelo comércio de Carbono quanto pela produção de madeira, principalmente para fins energéticos, de modo que a função social da propriedade, como prevista em lei, seja alcançada.

  2. Novel 14-nm Scallop-Shaped FinFETs (S-FinFETs) on Bulk-Si Substrate

    OpenAIRE

    Xu, Weijia; Yin, Huaxiang; Ma, Xiaolong; Hong, Peizhen; Xu, Miao; Meng, Lingkuan

    2015-01-01

    In this study, novel p-type scallop-shaped fin field-effect transistors (S-FinFETs) are fabricated using an all-last high-k/metal gate (HKMG) process on bulk-silicon (Si) substrates for the first time. In combination with the structure advantage of conventional Si nanowires, the proposed S-FinFETs provide better electrostatic integrity in the channels than normal bulk-Si FinFETs or tri-gate devices with rectangular or trapezoidal fins. It is due to formation of quasi-surrounding gate electrod...

  3. Parametric CFD Analysis to Study the Influence of Fin Geometry on the Performance of a Fin and Tube Heat Exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2016-01-01

    Heat transfer and pressure loss characteristics of a fin and tube heat exchanger are numerically investigated based on parametric fin geometry. The cross-flow type heat exchanger with circular tubes and rectangular fin profile is selected as a reference design. The fin geometry is varied using...... a design aspect ratio as a variable parameter in a range of 0.1-1.0 to predict the impact on overall performance of the heat exchanger. In this paper, geometric profiles with a constant thickness of fin base are studied. Three-dimensional, steady state CFD model is developed using commercially available...... are determined. The best performed geometric fin profile based on the higher heat transfer and lower pressure loss is predicted. The study provides insights into the impact of fin geometry on the heat transfer performance which help escalate the understanding of heat exchanger designing and manufacturing...

  4. Gas-flow detector for uranium contamination on finned-can surface of a reactor fuel; Detecteur a courant gazeux pour deceler la contamination en uranium des nervures des gaines de combustible nucleaire; Gazopotochnyj detektor zagryazneniya uranom rebristoj poverkhnosti obolochki reaktornykh teplovydelyayushchikh ehlementov; Detector de flujo gaseoso para medir la contaminacion de uranio en la superficie de la vaina de aletas de los elementos combustibles para reactores

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, H; Shiojiri, T; Maeda, Y [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)

    1962-04-15

    This gas-flow detector is a gridded proportional-counter specially designed for detecting uranium contamination on the finned-can surface of a reactor fuel. A conventional proportional-counter constructed only by a cathode and collector can hardly detect alpha particles emitted from uranium which is contaminated on rugged surfaces such as those of the fins of a reactor-fuel can because of the lack of uniformity of the electric field near the surface. This is the reason why we have constructed the gridded proportional-counter. This counter comprises the fuel, a grid, collectors and a cathode which are cylindrical in construction and arranged coaxially. The fuel is placed in the centre of the grid and negative voltage is applied. The space between the fuel and the grid serves as an ion-collecting space. The grid is made of fine parallel tungsten wires which are constructed cylindrically around the fuel and connected to ground potential. The collectors are 16 fine tungsten wires constructed similarly to the grid, but each wire is electrically insulated from the others. Through 50-k{Omega} resistors all collectors are connected together and to positive high voltage via a feeding resistor. The space between the grid, the collectors and the cathode serves as a gas-multiplication space just like a conventional proportional-counter. Each 50-k{Omega} resistor separates the stray capacity of the connected collector from the others. The detector output is coupled with a low input-impedance-current amplifier. The low inputimpedance also lessens the bad influence of the stray capacity of the input circuitry. These result in a good S/N ratio and allow the sensitive detection of alpha particles. Before measurement, the counter is first evacuated by a rotary pump and then PR gas (A: 90%, Methane: 10%) is admitted. By the use of this new equipment we have successfully detected alpha particles emitted from 1 x 10{sup -5} g natural-uranium contamination of the finned-can surface of a

  5. Undulating fins produce off-axis thrust and flow structures.

    Science.gov (United States)

    Neveln, Izaak D; Bale, Rahul; Bhalla, Amneet Pal Singh; Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A

    2014-01-15

    While wake structures of many forms of swimming and flying are well characterized, the wake generated by a freely swimming undulating fin has not yet been analyzed. These elongated fins allow fish to achieve enhanced agility exemplified by the forward, backward and vertical swimming capabilities of knifefish, and also have potential applications in the design of more maneuverable underwater vehicles. We present the flow structure of an undulating robotic fin model using particle image velocimetry to measure fluid velocity fields in the wake. We supplement the experimental robotic work with high-fidelity computational fluid dynamics, simulating the hydrodynamics of both a virtual fish, whose fin kinematics and fin plus body morphology are measured from a freely swimming knifefish, and a virtual rendering of our robot. Our results indicate that a series of linked vortex tubes is shed off the long edge of the fin as the undulatory wave travels lengthwise along the fin. A jet at an oblique angle to the fin is associated with the successive vortex tubes, propelling the fish forward. The vortex structure bears similarity to the linked vortex ring structure trailing the oscillating caudal fin of a carangiform swimmer, though the vortex rings are distorted because of the undulatory kinematics of the elongated fin.

  6. La Experiencia Contemporánea como Expresión del Fin de una Ética

    OpenAIRE

    Perdomo, José Camilo

    2004-01-01

    Educere:Una Brizna de Aliento en el Tiempo Rivas, Pedro El Paradigma Reinante y su Paideia Alonso, Leonor La Experiencia Contemporánea como Expresión del Fin de una ÉticaAlgunas Ideas desde la Postmodernidad para Releer el Dato Educativo Perdomo, José Camilo La Sociedad del Conocimiento y el Fin de la Escuela Rodríguez Rojas, Pedro Escuela, Alteridad y Experiencia de SíLa Producción Pedagógica del Sujeto Valera Villegas, G...

  7. FinTech Market Development Perspectives

    OpenAIRE

    Kalmykova, Ekaterina Yurievna; Ryabova, Anna

    2016-01-01

    Fast development of technologies has led to emergence of the new market – FinTech – which is very attractive for investors today. By now this market has a great number of different concepts: P2P-crediting, E-wallets, Bitcoins, mPOS-acquiring, T-commerce, mobile banks, etc. Many of these tools have already heavily entered our ordinary life. People can obtain any credits through special services on the Internet from other users without participation of banks, pay by credit card using mobile dev...

  8. Strain relaxation of germanium-tin (GeSn) fins

    Science.gov (United States)

    Kang, Yuye; Huang, Yi-Chiau; Lee, Kwang Hong; Bao, Shuyu; Wang, Wei; Lei, Dian; Masudy-Panah, Saeid; Dong, Yuan; Wu, Ying; Xu, Shengqiang; Tan, Chuan Seng; Gong, Xiao; Yeo, Yee-Chia

    2018-02-01

    Strain relaxation of biaxially strained Ge1-xSnx layer when it is patterned into Ge1-xSnx fin structures is studied. Ge1-xSnx-on-insulator (GeSnOI) substrate was realized using a direct wafer bonding (DWB) technique and Ge1-xSnx fin structures were formed by electron beam lithography (EBL) patterning and dry etching. The strain in the Ge1-xSnx fins having fin widths (WFin) ranging from 1 μm down to 80 nm was characterized using micro-Raman spectroscopy. Raman measurements show that the strain relaxation increases with decreasing WFin. Finite element (FE) simulation shows that the strain component in the transverse direction relaxes with decreasing WFin, while the strain component along the fin direction remains unchanged. For various Ge1-xSnx fin widths, transverse strain relaxation was further extracted using micro-Raman spectroscopy, which is consistent with the simulation results.

  9. Numerical simulation of heat exchangers elliptical tubes and corrugated fins

    International Nuclear Information System (INIS)

    Borrajo Pérez, Rubén; González Bayón, Juan José; Menéndez Pérez, Alberto

    2015-01-01

    The intensified heat exchangers fins are widely used in the automotive and domestic industry. The low heat transfer coefficients on the air side are the main reason why these fins of heat exchangers need to be intensified. In this paper, the numerical simulation of a wavy fin type is made with elliptical tubes. The dimensions of the fin is in the range of those used in air conditioning equipment. The friction factor and the mass transfer coefficient as a function of the Reynolds number for this type of fin, always within the laminar regime is determined. The numerical model against experimental results published in the literature is validated. In addition the mechanisms that produce intensified heat transfer fin in such occur. (full text)

  10. Research on dynamic characteristics of new chaotic-advection fins

    International Nuclear Information System (INIS)

    Kong Songtao; Dong Qiwu; Liu Minshan; Zhu Qing

    2007-01-01

    Analysis and the numerical simulation has confirmed that the flow is of the chaotic advection in the flow channel of the new fin. The chaotic advection results in stronger mixing under low Re, and thus enhances the heat transfer and anti-scaling ability. The new fin provides the beneficial exploration to the concept of chaotic advection which applies to the plate-fin heat exchanger. (authors)

  11. DETERMINATION OF THE TEMPERATURE DISTRIBUTION THE PERFORATED FINS UNDER

    Directory of Open Access Journals (Sweden)

    Aziz7 M. Mhamuad

    2015-02-01

    Full Text Available This work treats the problem of heat transfer for perforated fins under natural convection. The temperature distribution is examined for an array of rectangular fins (15 fins with uniform cross-sectional area (100x270 mm embedded with various vertical body perforations that extend through the fin thickness. The patterns of perforations include 18 circular perforations (holes. Experiments were carried out in an experimental facility that was specifically design and constructed for this purpose. The heat transfer rate and the coefficient of heat transfer increases with perforation diameter increased. 

  12. Flexibilidad laboral: ¿fin del trabajo permanente?

    Directory of Open Access Journals (Sweden)

    Carmen Añez Hernández

    2016-05-01

    Full Text Available Los trabajos transitorios o atípicos, siguen posicionándose y funcionando trastocando la protección del sistema de regulación y protección del trabajo permanente. De ahí, la importancia de reflexionar teóricamente sobre el tema. Para su desarrollo se plantean los siguientes objetivos: demostrar que la flexibilización laboral ha incidido en la ruptura de las relaciones laborales, caracterizar como la subcontratación laboral encubre dichas relaciones, analizar el despido laboral y sus consecuencias en los trabajadores. El artículo se desarrolló teóricamente, especialmente tomando como referencia autores como: Bravo (2010, Quintero (2010, González (2012 De La Garza (2007, Ugarte (2007, entre otros, lo cual permitió analizar la temática abordada. Los resultados reflejan que dicha estrategia está impulsando la agudización de las condiciones precarias de los derechos laborales, con lo cual se está ante un capitalismo irracional, que tiene como propósito que los trabajadores sufraguen los efectos de las pretensiones de los capitalistas por conseguir mayores tasas de ganancia y niveles más altos de productividad. En consecuencia, la flexibilización de las relaciones laborales está destinada a ocultar los derechos de los trabajadores, agudizar el despido laboral, y propiciar el fin de un trabajo permanente.

  13. Numerical studies on heat transfer and pressure drop characteristics of flat finned tube bundles with various fin materials

    Science.gov (United States)

    Peng, Y.; Zhang, S. J.; Shen, F.; Wang, X. B.; Yang, X. R.; Yang, L. J.

    2017-11-01

    The air-cooled heat exchanger plays an important role in the field of industry like for example in thermal power plants. On the other hand, it can be used to remove core decay heat out of containment passively in case of a severe accident circumstance. Thus, research on the performance of fins in air-cooled heat exchangers can benefit the optimal design and operation of cooling systems in nuclear power plants. In this study, a CFD (Computational Fluid Dynamic) method is implemented to investigate the effects of inlet velocity, fin spacing and tube pitch on the flow and the heat transfer characteristics of flat fins constructed of various materials (316L stainless steel, copper-nickel alloy and aluminium). A three dimensional geometric model of flat finned tube bundles with fixed longitudinal tube pitch and transverse tube pitch is established. Results for the variation of the average convective heat transfer coefficient with respect to cooling air inlet velocity, fin spacing, tube pitch and fin material are obtained, as well as for the pressure drop of the cooling air passing through finned tube. It is shown that the increase of cooling air inlet velocity results in enhanced average convective heat transfer coefficient and decreasing pressure drop. Both fin spacing and tube pitch engender positive effects on pressure drop and have negative effects on heat transfer characteristics. Concerning the fin material, the heat transfer performance of copper-nickel alloy is superior to 316L stainless steel and inferior to aluminium.

  14. PZT thin film actuated elastic fin micromotor.

    Science.gov (United States)

    Dubois, M A; Muralt, P

    1998-01-01

    A piezoelectric elastic fin micromotor based on a PbZr(0.53 )Ti(0.47)O(3) thin film driving a micromachined silicon membrane was fabricated and studied. The stator was characterized by interferometry, and a laser set-up was used to measure the angular velocity and acceleration of the motor. The torque, the output power, and the efficiency of the device were extracted from these measurements. Values up to 1020 rpm and 0.94 microNm were observed for the velocity and the torque, respectively, which would be sufficient for a wristwatch application. The present version exhibited an efficiency of 0.17%, which could theoretically be increased to 4.8%

  15. Numerical simulation of a plate-fin heat exchanger with offset fins using porous media approach

    Science.gov (United States)

    Juan, Du; Hai-Tao, Zhao

    2018-03-01

    In this paper, the study was focused on a double flow plate-fin heat exchanger (PFHE) whose heat transfer element was offset staggered fin. Numerical simulations have been carried out to investigate the thermodynamic characteristics of a full-size PFHE via the porous media approach. Based on the numerical model, the effects of the dynamic viscosity and the locations of the inlet and outlet tubes on flow distribution and pressure drop of the PFHE were studied. The results showed that flow distribution of the PFHE was improved by increasing the dynamic viscosity. Therefore, the relationship between flow distribution and pressure drop was analyzed under various inlet velocity, and a correlation among flow distribution, pressure drop, and Reynolds number was derived. Finally, the middle-based strategy was proposed and numerically verified to improve flow distribution of the PFHE.

  16. En Defensa del Fin de Lucro en Salud.

    Directory of Open Access Journals (Sweden)

    Ramón Abel Castaño Yepes

    2007-06-01

    La quinta premisa se deriva de la cuarta y de la segunda, es decir, que si el diseño del sistema de salud introducido por la Ley 100 tiene como elemento distintivo el fin de lucro, entonces el resultado de dicho diseño tiene que ser indeseable, puesto que el fin de lucro es indeseable...

  17. Optimum length of finned pipe for waste heat recovery

    International Nuclear Information System (INIS)

    Soeylemez, M.S.

    2008-01-01

    A thermoeconomic feasibility analysis is presented yielding a simple algebraic optimization formula for estimating the optimum length of a finned pipe that is used for waste heat recovery. A simple economic optimization method is used in the present study by combining it with an integrated overall heat balance method based on fin effectiveness for calculating the maximum savings from a waste heat recovery system

  18. Experimental Validation of Elliptical Fin-Opening Behavior

    Directory of Open Access Journals (Sweden)

    James M. Garner

    2003-01-01

    Full Text Available An effort to improve the performance of ordnance has led to the consideration of the use of folding elliptical fins for projectile stabilization. A second order differential equation was used to model elliptical fin deployment history and accounts for: deployment with respect to the geometric properties of the fin, the variation in fin aerodynamics during deployment, the initial yaw effect on fin opening, and the variation in deployment speed based on changes in projectile spin. This model supports tests conducted at the Transonic Experimental Facility, Aberdeen Proving Ground examining the opening behavior of these uniquely shaped fins. The fins use the centrifugal force from the projectile spin to deploy. During the deployment, the fin aerodynamic forces vary with angle-of-attack changes to the free stream. Model results indicate that projectile spin dominates the initial opening rates and aerodynamics dominate near the fully open state. The model results are examined to explain the observed behaviors, and suggest improvements for later designs.

  19. High performance flexible CMOS SOI FinFETs

    KAUST Repository

    Fahad, Hossain M.; Sevilla, Galo T.; Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

    2014-01-01

    We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due

  20. FinFET modeling for IC simulation and design

    CERN Document Server

    Hu, Chenming; Lu, Darsen D

    2015-01-01

    This book is the first to explain FinFET modeling for IC simulation and the industry standard - BSIM-CMG - describing the rush in demand for advancing the technology from planar to 3D architecture, as now enabled by the approved industry standard. The book gives a strong foundation on the physics and operation of FinFET, details aspects of the BSIM-CMG model such as surface potential, charge and current calculations, and includes a dedicated chapter on parameter extraction procedures, providing a step-by-step approach for the efficient extraction of model parameters. With this book you will learn: * Why you should use FinFET* The physics and operation of FinFET* Details of the FinFET standard model (BSIM-CMG)* Parameter extraction in BSIM-CMG* FinFET circuit design and simulation * Authored by the lead inventor and developer of FinFET, and developers of the BSIM-CM standard model, providing an experts' insight into the specifications of the standard* The first book on the industry-standard FinFET model - BSIM...

  1. Propulsion of a fin whale (Balaenoptera physalus): why the fin whale is a fast swimmer.

    Science.gov (United States)

    Bose, N; Lien, J

    1989-07-22

    Measurements of an immature fin whale (Balaenoptera physalus), which died as a result of entrapment in fishing gear near Frenchmans Cove, Newfoundland (47 degrees 9' N, 55 degrees 25' W), were made to obtain estimates of volume and surface area of the animal. Detailed measurements of the flukes, both planform and sections, were also obtained. A strip theory was developed to calculate the hydrodynamic performance of the whale's flukes as an oscillating propeller. This method is based on linear, two-dimensional, small-amplitude, unsteady hydrofoil theory with correction factors used to account for the effects of finite span and finite amplitude motion. These correction factors were developed from theoretical results of large-amplitude heaving motion and unsteady lifting-surface theory. A model that makes an estimate of the effects of viscous flow on propeller performance was superimposed on the potential-flow results. This model estimates the drag of the hydrofoil sections by assuming that the drag is similar to that of a hydrofoil section in steady flow. The performance characteristics of the flukes of the fin whale were estimated by using this method. The effects of the different correction factors, and of the frictional drag of the fluke sections, are emphasized. Frictional effects in particular were found to reduce the hydrodynamic efficiency of the flukes significantly. The results are discussed and compared with the known characteristics of fin-whale swimming.

  2. Development of a Simulation Model for Swimming with Diving Fins

    Directory of Open Access Journals (Sweden)

    Motomu Nakashima

    2018-02-01

    Full Text Available The simulation model to assess the performance of diving fin was developed by extending the swimming human simulation model SWUM. A diving fin was modeled as a series of five rigid plates and connected to the human model by springs and dampers. These plates were connected to each other by virtual springs and dampers, and fin’s bending property was represented by springs and dampers as well. An actual diver’s swimming motion with fins was acquired by a motion capture experiment. In order to determine the bending property of the fin, two bending tests on land were conducted. In addition, an experiment was conducted in order to determine the fluid force coefficients in the fluid force model for the fin. Finally, using all measured and identified information, a simulation, in which the experimental situation was reproduced, was carried out. It was confirmed that the diver in the simulation propelled forward in the water successfully.

  3. A contribuicao do direito nuclear para o melhor aproveitamento da energia nuclear para fins pacifico

    International Nuclear Information System (INIS)

    Puig, D.E.

    1983-01-01

    The text describes the contribution of nuclear law in order to improve the nuclear energy utiliation for peaceful uses. The actuation of the nuclear law as mediator between the nuclear progress and its consequences aiming to get better life conditions and education as base for developing are shown [pt

  4. Simulation study of a 3-D device integrating FinFET and UTBFET

    KAUST Repository

    Fahad, Hossain M.; Hu, Chenming; Hussain, Muhammad Mustafa

    2015-01-01

    By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate Fin

  5. ¿El principio del fin o el fin del principio? - Apuntes para una revolución

    Directory of Open Access Journals (Sweden)

    Dr. Ángel Luis Acosta Romero

    1998-01-01

    Full Text Available Al final del segundo milenio nos encontramos, sin duda, en una encrucijada histórica. Y no creemos que se trate sólo, aunque también, de un tópico repetido, y, casi siempre, adornado con tintes apocalípticos. Una encrucijada es un cruce de caminos, es decir, la duda y la apertura a distintas posibilidades. La duda, es cierto, nos obliga elegir. La libertad, en este caso, se nos impone. Debemos elegir y debemos hacerlo siendo conscientes de nuestros límites y de nuestras potencialidades. La crisis de la sociedad -de un modelo de sociedad- refleja y es reflejada por la crisis del conocimiento. Ya sabemos que el sujeto y el objeto se configuran mutuamente y no pueden ser aislados artificialmente. Afrontar la revolución en el conocimiento es afrontar, al mismo tiempo, una revolución política, es decir, una revolución integral, en la que el hombre (la humanidad se reconozca en su devenir complejo (homo sapiens/demens le llama Morin.

  6. FinTech Market Development Perspectives

    Directory of Open Access Journals (Sweden)

    Kalmykova Ekaterina

    2016-01-01

    Full Text Available Fast development of technologies has led to emergence of the new market – FinTech – which is very attractive for investors today. By now this market has a great number of different concepts: P2P-crediting, E-wallets, Bitcoins, mPOS-acquiring, T-commerce, mobile banks, etc. Many of these tools have already heavily entered our ordinary life. People can obtain any credits through special services on the Internet from other users without participation of banks, pay by credit card using mobile devices, and get information about expenses and incomes according to the card anywhere in the world. Users do not need to go to banks anymore and to spend their time for credit arrangements, currency exchange, to look for ATMs to remove cash. Purchases on the Internet can be paid not only in rubles, but also in new digital currency. These tools make life easier, however, they pose a serious threat for banks. Now, bank institutions should create more convenient and utility services for the clients to keep clients. Therefore, bank and credit systems start to change actively.

  7. 3D modeling of dual-gate FinFET.

    Science.gov (United States)

    Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

    2012-11-13

    The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

  8. A note on the heat transfer in convective fins

    International Nuclear Information System (INIS)

    Razelos, P.

    1979-01-01

    In this paper a generalized approach to the problem of heat transfer through convective fins is given. The proper dimensionless variables, which specify the general problem are identified, and upper bounds of the values of the dimensionless number Nsub(r) defined as 'the ratio of the heat transferred by the fin to that of the corresponding bare surface' are derived. It was shown that these limiting values of the Nsub(r) are 1/√B 1 and √2/B 1 for longitudinal fins and spines respectively, where B 1 is the Biot number hb/k, while for annular fins of constant thickness and hyperbolic profile, Nsub(r) 1 , where K(β) is a number determined by the profile of the fin and the ratio β = x 2 /x 1 of the outside to the inside radii. It was also shown that for longitudinal fins and spinces the possible adverse insulating effect by the use of the fin is avoided, if one selects the value of √hA/kC [de

  9. Evaluation of integrally finned cladding for LMFBR fuel pins

    International Nuclear Information System (INIS)

    Cantley, D.A.; Sutherland, W.H.

    1975-01-01

    An integral fin design effectively reduces the coolant temperature gradients within an LMFBR subassembly by redistributing coolant flow so as to reduce the maximum cladding temperature and increase the duct wall temperature. The reduced cladding temperatures are offset by strain concentrations resulting from the fin geometry, so there is little net effect on predicted fuel pin performance. The increased duct wall temperatures, however, significantly reduce the duct design lifetime so that the final conclusion is that the integral fin design is inferior to the standard wire wrap design. This result, however, is dependent upon the material correlations used. Advanced alloys with improved irradiation properties could alter this conclusion

  10. Robotic Pectoral Fin Thrust Vectoring Using Weighted Gait Combinations

    Directory of Open Access Journals (Sweden)

    John S. Palmisano

    2012-01-01

    Full Text Available A method was devised to vector propulsion of a robotic pectoral fin by means of actively controlling fin surface curvature. Separate flapping fin gaits were designed to maximize thrust for each of three different thrust vectors: forward, reverse, and lift. By using weighted combinations of these three pre-determined main gaits, new intermediate hybrid gaits for any desired propulsion vector can be created with smooth transitioning between these gaits. This weighted gait combination (WGC method is applicable to other difficult-to-model actuators. Both 3D unsteady computational fluid dynamics (CFD and experimental results are presented.

  11. Del fin de la guerra fria al comienzo de la guerra sin fin

    OpenAIRE

    Ferrier, Jean Pierre

    2006-01-01

    El Profesor Ferrier nos describe los acontecimientos de la sociedad internacional en los ultimos 15 años y señala la profunda diferencia entre "la estabilidad" durante la guerra fría y la "revolucion" que se ha producido en el escenario internacional a partir de la caida del muro de Berlin. Hace especial referencia al comportamiento de la superpotencia (Estados Unidos) y su guerra sin fin contra los "nuevos enemigos" en los diferentes teatros internacionales en su lucha por imponer el "Bien" ...

  12. Aura fractal, fins da arte e capitalismo primitivista

    Directory of Open Access Journals (Sweden)

    Leonardo Carvalho Bertolossi

    2017-10-01

    Full Text Available Objetiva-se refletir sobre as relações entre as artes visuais e a antropologia a partir do texto seminal de Walter Benjamin sobre a aura para pensar sobre as finalidades e os fins da metafísica da arte no Ocidente diante dos diagnósticos de fim de mundo/fim da história da arte, e da vitória do espetáculo e da indústria cultural no capitalismo contemporâneo. O artigo apresenta alguns dos sentidos da arte no mundo ocidental e em especial no romantismo, avança sobre a crise e o fim dos modelos estruturais e cognitivos do pensamento artístico moderno, destaca o interesse pela política e pela vida, e se indaga sobre a retomada do primitivismo nas artes visuais e na antropologia contemporânea como redenção e renovação das mortes anunciadas. ABSTRACT The objective is to reflect on the relations between the visual arts and anthropology from Walter Benjamin's seminal text on the aura to think about the purposes and ends of the metaphysics of art in the West in the face of end-of-world/end-of-art history, and the victory of spectacle and cultural industry in contemporary capitalism. The article presents some of the meanings of art in the Western world and especially in Romanticism, advances on the crisis and the end of the structural and cognitive models of modern artistic thought, highlights the interest in politics and life, and inquires about the resumption of Primitivism in the visual arts and contemporary anthropology as redemption and renewal of the announced deaths. KEYWORDS Anthropology of art, aura, soul, thanatology, primitivism

  13. Fish locomotion: kinematics and hydrodynamics of flexible foil-like fins

    Science.gov (United States)

    Lauder, George V.; Madden, Peter G. A.

    2007-11-01

    The fins of fishes are remarkable propulsive devices that appear at the origin of fishes about 500 million years ago and have been a key feature of fish evolutionary diversification. Most fish species possess both median (midline) dorsal, anal, and caudal fins as well as paired pectoral and pelvic fins. Fish fins are supported by jointed skeletal elements, fin rays, that in turn support a thin collagenous membrane. Muscles at the base of the fin attach to and actuate each fin ray, and fish fins thus generate their own hydrodynamic wake during locomotion, in addition to fluid motion induced by undulation of the body. In bony fishes, the jointed fin rays can be actively deformed and the fin surface can thus actively resist hydrodynamic loading. Fish fins are highly flexible, exhibit considerable deformation during locomotion, and can interact hydrodynamically during both propulsion and maneuvering. For example, the dorsal and anal fins shed a vortex wake that greatly modifies the flow environment experienced by the tail fin. New experimental kinematic and hydrodynamic data are presented for pectoral fin function in bluegill sunfish. The highly flexible sunfish pectoral fin moves in a complex manner with two leading edges, a spanwise wave of bending, and substantial changes in area through the fin beat cycle. Data from scanning particle image velocimetry (PIV) and time-resolved stereo PIV show that the pectoral fin generates thrust throughout the fin beat cycle, and that there is no time of net drag. Continuous thrust production is due to fin flexibility which enables some part of the fin to generate thrust at all times and to smooth out oscillations that might arise at the transition from outstroke to instroke during the movement cycle. Computational fluid dynamic analyses of sunfish pectoral fin function corroborate this conclusion. Future research on fish fin function will benefit considerably from close integration with studies of robotic model fins.

  14. Results from the FIN-2 formal comparison

    Science.gov (United States)

    Connolly, Paul; Hoose, Corinna; Liu, Xiaohong; Moehler, Ottmar; Cziczo, Daniel; DeMott, Paul

    2017-04-01

    During the Fifth International Ice Nucleation Workshop (FIN-2) at the AIDA Ice Nucleation facility in Karlsruhe, Germany in March 2015, a formal comparison of ice nucleation measurement methods was conducted. During the experiments the samples of ice nucleating particles were not revealed to the instrument scientists, hence this was referred to as a "blind comparison". The two samples used were later revealed to be Arizona Test Dust and an Argentina soil sample. For these two samples seven mobile ice nucleating particle counters sampled directly from the AIDA chamber or from the aerosol preparation chamber at specified temperatures, whereas filter samples were taken for two offline deposition nucleation instruments. Wet suspension methods for determining IN concentrations were also used with 10 different methods employed. For the wet suspension methods experiments were conducted using INPs collected from the air inside the chambers (impinger sampling) and INPs taken from the bulk samples (vial sampling). Direct comparisons of the ice nucleating particle concentrations are reported as well as derived ice nucleation active site densities. The study highlights the difficulties in performing such analyses, but generally indicates that there is reasonable agreement between the wet suspension techniques. It is noted that ice nucleation efficiency derived from the AIDA chamber (quantified using the ice active surface site density approach) is higher than that for the cold stage techniques. This is both true for the Argentina soil sample and, to a lesser extent, for the Arizona Test Dust sample too. Other interesting effects were noted: for the ATD the impinger sampling demonstrated higher INP efficiency at higher temperatures (>255 K) than the vial sampling, but agreed at the lower temperatures (<255K), whereas the opposite was true for the Argentina soil sample. The results are analysed to better understand the performance of the various techniques and to address any

  15. El efecto fin de mes en los principales mercados accionarios latinoamericanos

    Directory of Open Access Journals (Sweden)

    Werner Kristjanpoller Rodríguez

    2015-01-01

    Full Text Available En los mercados accionarios es frecuente encontrar anomalías de calendario, las cuales han sido objeto de diversos estudios en estas últimas décadas, incluso demostrándose que algunas de ellas a través del tiempo han ido desapareciendo. En este contexto, este artículo analiza una de estas anomalías, el efecto fin de mes, tanto en rendimiento como en volatilidad en los mercados accionarios de seis países latinoamericanos; a saber, Brasil, México, Chile, Colombia, Perú y Argentina en el periodo 1993-2011. La importancia de este estudio radica en poder probar si el efecto de fin de mes ha ido desapareciendo o aún persiste, ya que algunos efectos calendario en mercados accionarios desarrollados se han ido disipando. Los hallazgos de esta investigación, que se realizó de acuerdo con los tres periodos diferentes definidos en la literatura para analizar el impacto fin de mes, muestran que la mayoría de los países bajo análisis obtienen rendimientos anormales positivos en los días asociados al cambio de mes y también muestran anomalías en la volatilidad. Esta investigación no solamente analiza los índices característicos de cada mercado, sino que también las acciones en particular de cada uno, dotándolo de una muestra mucho mayor y exigente al momento de concluir sobre la existencia del fenómeno. También se incluye un análisis de volumen de transacción para verificar ciertas hipótesis del fenómeno asociadas a mayor flujo de efectivo.

  16. Flexible nanoscale high-performance FinFETs

    KAUST Repository

    Sevilla, Galo T.

    2014-10-28

    With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show a soft-etch based substrate thinning process to transform silicon-on-insulator (SOI) based nanoscale FinFET into flexible FinFET and then conduct comprehensive electrical characterization under various bending conditions to understand its electrical performance. Our study shows that back-etch based substrate thinning process is gentler than traditional abrasive back-grinding process; it can attain ultraflexibility and the electrical characteristics of the flexible nanoscale FinFET show no performance degradation compared to its rigid bulk counterpart indicating its readiness to be used for flexible high-performance electronics.

  17. Transient heat transfer in longitudinal fins of various profiles with ...

    Indian Academy of Sciences (India)

    School of Computational and Applied Mathematics, University of the Witwatersrand, ... by frequent encounters of fin problems in many engineering applications to enhance heat transfer. In recent .... where β is the thermal conductivity gradient.

  18. Heat transfer in laminar flow for a finned double - tube

    International Nuclear Information System (INIS)

    Colle, S.

    1977-01-01

    An analitical study of the steady-state heat transfer in laminar flow in finned double-tube heat exchangers is presented. The fins are plane, straight and continous, equally spaced and are fixed over the external surface of the inner tube. A constant peripheral temperature distribution is assumed to apply over the inner tube surface and each fin, and a constant peripheral heat flux is assumed to apply over the outer tube surface, while the overall heat flux is suposed to be uniform in the longitudinal direction of the duct. The prediction of the thermal performance of the finned double-tube is made by means of the relationship between the Nusselt number, the boundary conditions and the geometric characteristcs of the duct. (author) [pt

  19. Hydrodynamical analysis of the effect of fish fins morphology

    Science.gov (United States)

    Azwadi Che Sidik, Nor; Yen, Tey Wah

    2013-12-01

    The previous works on the biomechanics of fishes focuses on the locomotion effect of the fish bodies. However, there is quite a insufficiency in unveiling the respective function of fins when the fishes pose statics and exposed to fluid flow. Accordingly, this paper's focus is to investigate the hydrodynamic effect of the fins configuration to the fluid flow of shark-shaped-inspired structure. The drag and lift coefficient is computed for different cases of fish fins addition and configuration. The k-epsilon turbulence model is deployed using finite volume method with the aid of commercial software ANSYS CFX. The finding will demystify some of the functions of the fish's fins in term of their contribution to the hydrodynamic flow around the fishes.

  20. Steady-state and transient heat transfer through fins of complex geometry

    Directory of Open Access Journals (Sweden)

    Taler Dawid

    2014-06-01

    Full Text Available Various methods for steady-state and transient analysis of temperature distribution and efficiency of continuous-plate fins are presented. For a constant heat transfer coefficient over the fin surface, the plate fin can be divided into imaginary rectangular or hexangular fins. At first approximate methods for determining the steady-state fin efficiency like the method of equivalent circular fin and the sector method are discussed. When the fin geometry is complex, thus transient temperature distribution and fin efficiency can be determined using numerical methods. A numerical method for transient analysis of fins with complex geometry is developed. Transient temperature distributions in continuous fins attached to oval tubes is computed using the finite volume - finite element methods. The developed method can be used in the transient analysis of compact heat exchangers to calculate correctly the heat flow rate transferred from the finned tubes to the fluid.

  1. Venus y el fin del mundo

    Directory of Open Access Journals (Sweden)

    Gonzalo Munévar

    2006-01-01

    Full Text Available Este artículo busca demostrar que los argumentos generales acerca de la exploración científica valen también para las ciencias espaciales. El trabajo se basa en el ejemplo de la exploración de Venus y lo que esta nos dice acerca de nuestro propio planeta. Argumenta que el concepto de la probabilidad de Leslie es incorrecto, como también lo son las dudas sobre la evidencia Venusiana. Así mismo, concluye que no se puede rechazar la importancia que tienen los descubrimientos inesperados que han resultado de la exploración de Venus para ayudarnos a comprender nuestro propio planeta. Y que si van a ser rechazados estos descubrimientos debe ser por razones científicas, no por intuiciones acerca de la probabilidad.

  2. A exclusão social no marco da comunicação para o desenvolvimento e a mudança social. Uma análise do tratamento da inclusão social em campanhas de serviço público sem fins lucrativos

    OpenAIRE

    Alvarado López, María Cruz; de Andrés del Campo, Susana; Collado Alonso, Rocío

    2017-01-01

    Este trabajo pretende ubicar el concepto de comunicación inclusiva en el marco de la comunicación para el desarrollo y el cambio social. Se recogen y analizan las referencias a la inclusión social en los textos fundacionales de la comunicación para el cambio social. Se plantean las implicaciones del concepto de comunicación inclusiva y se aportan ejemplos en el ámbito de la comunicación publicitaria social. Se presentan los resultados de un análisis sobre el tratamiento de la inclusión-exclus...

  3. Diseño de estrategias para el uso pedagógico de las redes sociales a fin de mejorar el bajo rendimiento académico en la asignatura desarrollo del pensamiento filosófico del primer año de bachillerato en la Unidad Educativa Julio Moreno Espinosa

    OpenAIRE

    Ramón Orellana, Edison Manuel

    2013-01-01

    El ser humano en los inicios de la historia se puede decir que se educó o aprendió solo, con el avance social fueron apareciendo filósofos (Sócrates, Platón, Aristóteles) y mentes brillantes que de a poco se fueron convirtiendo en “profesores” para sus comunidades. Los conocimientos se compartían a través de ideas y no necesariamente se necesitaban de cuatro paredes para desarrollar la ciencia del conocimiento y por más primitiva que sea la sociedad el hombre se ha educado. Las bases de la ed...

  4. Water flow and fin shape polymorphism in coral reef fishes.

    Science.gov (United States)

    Binning, Sandra A; Roche, Dominique G

    2015-03-01

    Water flow gradients have been linked to phenotypic differences and swimming performance across a variety of fish assemblages. However, the extent to which water motion shapes patterns of phenotypic divergence within species remains unknown. We tested the generality of the functional relationship between swimming morphology and water flow by exploring the extent of fin and body shape polymorphism in 12 widespread species from three families (Acanthuridae, Labridae, Pomacentridae) of pectoral-fin swimming (labriform) fishes living across localized wave exposure gradients. The pectoral fin shape of Labridae and Acanthuridae species was strongly related to wave exposure: individuals with more tapered, higher aspect ratio (AR) fins were found on windward reef crests, whereas individuals with rounder, lower AR fins were found on leeward, sheltered reefs. Three of seven Pomacentridae species showed similar trends, and pectoral fin shape was also strongly related to wave exposure in pomacentrids when fin aspect ratios of three species were compared across flow habitats at very small spatial scales (fish body fineless ratio across habitats or depths. Contrary to our predictions, there was no pattern relating species' abundances to polymorphism across habitats (i.e., abundance was not higher at sites where morphology is better adapted to the environment). This suggests that there are behavioral and/or physiological mechanisms enabling some species to persist across flow habitats in the absence of morphological differences. We suggest that functional relationships between swimming morphology and water flow not only structure species assemblages, but are yet another important variable contributing to phenotypic differences within species. The close links between fin shape polymorphism and local water flow conditions appear to be important for understanding species' distributions as well as patterns of diversification across environmental gradients.

  5. Fin field effect transistor directionality impacts printing of implantation shapes

    Science.gov (United States)

    Wang, Xiren; Granik, Yuri

    2018-01-01

    In modern integrated circuit (IC) fabrication processes, the photoresist receives considerable illumination energy that is reflected by underlying topography during optical lithography of implantation layers. Bottom antireflective coating (BARC) is helpful to mitigate the reflection. Often, however, BARC is not used, because its removal is technically challenging, in addition to its relatively high economic cost. Furthermore, the advanced technology nodes, such as 14/10-nm nodes, have introduced fin field effect transistor (FinFET), which makes reflection from nonuniform silicon substrates exceptionally complicated. Therefore, modeling reflection from topography becomes obligatory to accurately predict printing of implantation shapes. Typically, FinFET is always fixed in one direction in realistic designs. However, the same implantation rectangle may be oriented in either horizontal or vertical direction. Then, there are two types of relations between the critical dimension (CD) and FinFET, namely a parallel-to and a perpendicular-to relation. We examine the fin directionality impact on CD. We found that this impact may be considerable in some cases. We use our in-house rigorous optical topography simulator to reveal underlining physical reasons. One of the major causes of the CD differences is that in the parallel orientation, the solid sidewalls of the fins conduct considerable light reflections unlike for the perpendicular orientation. This finding can aid the compact modeling in optical proximity correction of implantation masks.

  6. Stress analysis of plate-fin structures in recuperator

    International Nuclear Information System (INIS)

    Matsui, Shingo; Muto, Yasushi; Shiina, Yasuaki

    2001-01-01

    A high performance compact recuperator with 95% effectiveness is required to achieve a high thermal efficiency power generation of up to 50% in High Temperature Gas Cooled Reactor (HTGR) coupled with closed cycle helium gas turbine. Though a plate-fin type heat exchanger is proposed for this recuperator, much research and development works are needed to establish this high performance goal since there exists no state-of-the-art technology in such a high pressure and high temperature one. One of the important works is to establish the structural analysis and evaluation method in this plate-fin type heat exchanger. This paper describes the results of stress analysis of the plate-fin structure under the internal pressure as the first step of this work. First, the modeling of a unit plate-fin structure for the analysis was examined and a three layers model was confirmed to be most adequate. The stress distribution within the structure was clarified by using this model. Second, the three layers model was simplified to one layer model with sufficient accuracy. By using this model, both the effects of an inclined angle of fin and a thickness of separate on the strength were examined parametrically. Under the relevant design conditions, it was revealed that the optimum inclined angle of fin locates in the neighborhood of 76 degree rather than most difficult fabrication angle 90 degree and there is possibility to adopt thinner thickness than 0.5 mm in the current design. (author)

  7. Implications of fin profiles on overall performance and weight reduction of a fin and tube heat exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Simonsen, Anders Schou

    2017-01-01

    Fin and tube heat exchangers are being used in several industrial applications by means of novel design and optimized performance. Improvements in geometric design may deliver energy efficient and cost-effective heat exchanger performance with reduced weight. In this paper, a systematic study...... on a cross-flow type fin and tube heat exchanger design for a waste heat recovery application is conducted. The geometric profile of the fin is characterized by a dimensionless design variable named aspect ratio which is parametrically varied to obtain different profiles. Two cases, case-I, and case......,000 using computational fluid dynamics. The numerical results obtained for the reference fin profile are verified with the experimental correlations. Dimensionless parameters such as Nusselt number, Euler number, and efficiency index are calculated to predict the overall performance of the heat exchanger...

  8. Ha vuelto para mirarnos

    OpenAIRE

    Casalderrey, Francisco

    2008-01-01

    En cada entrega analizaremos un cuadro, mirándolo con ojos matemáticos. Con esa particular mirada, fruto de nuestra propia (de)formación. Y desde ese punto de vista haremos paseos por el arte y las matemáticas. Espero que el lector, como hago yo mismo, disfrute descubriendo más allá de lo que a simple vista distinguiría cualquiera. Al fin de cuentas, el arte, como las matemáticas, han sido creados para hacernos disfrutar.

  9. Ice nucleating particles measured during the laboratory and field intercomparisons FIN-2 and FIN-3 by the diffusion chamber FRIDGE

    Science.gov (United States)

    Weber, Daniel; Schrod, Jann; Curtius, Joachim; Haunold, Werner; Thomson, Erik; Bingemer, Heinz

    2016-04-01

    The measurement of atmospheric ice nucleating particles (INP) is still challenging. In the absence of easily applicable INP standards the intercomparison of different methods during collaborative laboratory and field workshops is a valuable tool that can shine light on the performance of individual methods for the measurement of INP [1]. FIN-2 was conducted in March 2015 at the AIDA facility in Karlsruhe as an intercomparison of mobile instruments for measuring INP [2]. FIN-3 was a field campaign at the Desert Research Institutes Storm Peak Laboratory in Colorado in September 2015 [3]. The FRankfurt Ice nucleation Deposition freezinG Experiment (FRIDGE) participated in both experiments. FRIDGE measures ice nucleating particles by electrostatic precipitation of aerosol particles onto Si-wafers in a collection unit, followed by activation, growth, and optical detection of ice crystals on the substrate in an isostatic diffusion chamber [4,5]. We will present and discuss results of our measurements of deposition/condensation INP and of immersion INP with FRIDGE during FIN-2 and FIN-3. Acknowledgements: The valuable contributions of the FIN organizers and their institutions, and of the FIN Workshop Science team are gratefully acknowledged. Our work was supported by Deutsche Forschungsgemeinschaft (DFG) under the Research Unit FOR 1525 (INUIT) and the EU FP7-ENV- 2013 BACCHUS project under Grant Agreement 603445.

  10. The performance of a new gas to gas heat exchanger with strip fin

    NARCIS (Netherlands)

    Wang, J.; Hirs, Gerard; Rollmann, P.

    1999-01-01

    A compact gas to gas heat exchanger needs large heat transfer areas on both fluid sides. This can be realised by adding secondary surfaces. The secondary surfaces are plate fin, strip fin, and louvered fin, etc. The fins extend the heat transfer surfaces and promote turbulence. This paper presents a

  11. Gene expression profiles of fin regeneration in loach (Paramisgurnus dabryanu).

    Science.gov (United States)

    Li, Li; He, Jingya; Wang, Linlin; Chen, Weihua; Chang, Zhongjie

    2017-11-01

    Teleost fins can regenerate accurate position-matched structure and function after amputation. However, we still lack systematic transcriptional profiling and methodologies to understand the molecular basis of fin regeneration. After histological analysis, we established a suppression subtraction hybridization library containing 418 distinct sequences expressed differentially during the process of blastema formation and differentiation in caudal fin regeneration. Genome ontology and comparative analysis of differential distribution of our data and the reference zebrafish genome showed notable subcategories, including multi-organism processes, response to stimuli, extracellular matrix, antioxidant activity, and cell junction function. KEGG pathway analysis allowed the effective identification of relevant genes in those pathways involved in tissue morphogenesis and regeneration, including tight junction, cell adhesion molecules, mTOR and Jak-STAT signaling pathway. From relevant function subcategories and signaling pathways, 78 clones were examined for further Southern-blot hybridization. Then, 17 genes were chosen and characterized using semi-quantitative PCR. Then 4 candidate genes were identified, including F11r, Mmp9, Agr2 and one without a match to any database. After real-time quantitative PCR, the results showed obvious expression changes in different periods of caudal fin regeneration. We can assume that the 4 candidates, likely valuable genes associated with fin regeneration, deserve additional attention. Thus, our study demonstrated how to investigate the transcript profiles with an emphasis on bioinformatics intervention and how to identify potential genes related to fin regeneration processes. The results also provide a foundation or knowledge for further research into genes and molecular mechanisms of fin regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Descrição de uma ferramenta digital e de um ambiente virtual para fins de segunda opinião em oftalmologia Description of a digital image system and a virtual environment to be used as a remote second referral option in ophthalmology

    Directory of Open Access Journals (Sweden)

    Alessandro Dantas Pennella

    2003-10-01

    Full Text Available OBJETIVOS: Idealizar, desenvolver e verificar a funcionalidade um sistema de teleoftalmologia para diagnóstico remoto em casos clínicos. MÉTODOS: Descrever o funcionamento e utilização do sistema, sua capacidade de captura, arquivamento e envio de imagens via internet, e de um domínio virtual voltado ao telediagnóstico, aconselhamento ou segunda opinião. RESULTADOS: Foram definidos os requisitos básicos, detalhes de programação e de funcionamento de um programa de captura de imagens. O funcionamento do mesmo acoplado a uma placa de captura de imagens foi realizado com sucesso, bem como a criação, na internet, de um domínio médico-oftalmológico. CONCLUSÃO: Os resultados preliminares permitiram a avaliação de um sistema misto para o suporte médico em nosso meio. Os instrumentos diagnósticos disponíveis bem como suas conexões com a rede foram satisfatórias e suficientes para viabilizar um estudo piloto bem su-cedido. O sistema revelou-se potencialmente adequado para o telediagnóstico e segunda opinião. O método necessita de testes clínicos e compa-ração com métodos diagnósticos tradicionais para comprovar a sua eficácia.PURPOSE: To investigate the possibilities of a teleophthalmology system to be used in a remote second referral program. METHODS: Digital images of the anterior segment were digitized by the Eyemail program and attached to the clinical description of the case and the file was sent to the website www.suportemedico.com.br for remote telediagnosis. The telediagnosis was then compared with the in loco diagnosis. RESULTS: The Eyemail system was able to capture images from the slit lamp and to send the files to the website. The website received the files and the operator was able to make the diagnosis using those files. CONCLUSION: The Eyemail system proved to have a potential use as a second referral program.

  13. Effects of fin shape on condensation in herringbone microfin tubes

    Energy Technology Data Exchange (ETDEWEB)

    Miyara, Akio [Saga University (Japan). Dept. of Mechanical Engineering; Otsubo, Yusuke; Ohtsuka, Satoshi; Mizuta, Yoshihiko [Saga University (Japan). Graduate School of Science and Engineering

    2003-06-01

    Effects of fin height and helix angle on condensation inside a herringbone microfin tube have been experimentally investigated with five types of herringbone microfin tubes. Heat transfer coefficients are about 2-4 times higher than that of the helical microfin tube under high mass velocity conditions. In the low mass velocity, they are equal to that of the helical microfin tube. The heat transfer enhancement increases with fin height up to 0.18 mm; higher fin heights show enhancement values similar to the 0.18 mm results. Pressure drop increases with the fin height. Larger helix angle yields higher heat transfer and higher pressure drop. For the lowest fin and/or smallest helix angle, the pressure drop is comparable with that of the helical microfin tube, while the heat transfer enhancement is higher. The enhancement mechanism is discussed from flow pattern observations. Effect of mass transfer resistance for R410A is estimated and negligible effects have been proved. (author)

  14. Optimization of geometric parameters of heat exchange pipes pin finning

    Science.gov (United States)

    Akulov, K. A.; Golik, V. V.; Voronin, K. S.; Zakirzakov, A. G.

    2018-05-01

    The work is devoted to optimization of geometric parameters of the pin finning of heat-exchanging pipes. Pin fins were considered from the point of view of mechanics of a deformed solid body as overhang beams with a uniformly distributed load. It was found out under what geometric parameters of the nib (diameter and length); the stresses in it from the influence of the washer fluid will not exceed the yield strength of the material (aluminum). Optimal values of the geometric parameters of nibs were obtained for different velocities of the medium washed by them. As a flow medium, water and air were chosen, and the cross section of the nibs was round and square. Pin finning turned out to be more than 3 times more compact than circumferential finning, so its use makes it possible to increase the number of fins per meter of the heat-exchanging pipe. And it is well-known that this is the main method for increasing the heat transfer of a convective surface, giving them an indisputable advantage.

  15. Strain characterization of FinFETs using Raman spectroscopy

    International Nuclear Information System (INIS)

    Kaleli, B.; Hemert, T. van; Hueting, R.J.E.; Wolters, R.A.M.

    2013-01-01

    Metal induced strain in the channel region of silicon (Si) fin-field effect transistor (FinFET) devices has been characterized using Raman spectroscopy. The strain originates from the difference in thermal expansion coefficient of Si and titanium-nitride. The Raman map of the device region is used to determine strain in the channel after preparing the device with the focused ion beam milling. Using the Raman peak shift relative to that of relaxed Si, compressive strain values up to – 0.88% have been obtained for a 5 nm wide silicon fin. The strain is found to increase with reducing fin width though it scales less than previously reported results from holographic interferometry. In addition, finite-element method (FEM) simulations have been utilized to analyze the amount of strain generated after thermal processing. It is shown that obtained FEM simulated strain values are in good agreement with the calculated strain values obtained from Raman spectroscopy. - Highlights: ► Strain is characterized in nanoscale devices with Raman spectroscopy. ► There is a fin width dependence of the originated strain. ► Strain levels obtained from this technique is in correlation with device simulations

  16. Numerical simulation of natural convection in annuli with internal fins

    International Nuclear Information System (INIS)

    Ha, Man Yeong; Kim, Joo Goo

    2004-01-01

    The solution for the natural convection in internally finned horizontal annuli is obtained by using a numerical simulation of time-dependent and two-dimensional governing equations. The fins existing in annuli influence the flow pattern, temperature distribution and heat transfer rate. The variations of the fin configuration suppress or accelerate the free convective effects compared to those of the smooth tubes. The effects of fin configuration, number of fins and ratio of annulus gap width to the inner cylinder radius on the fluid flow and heat transfer in annuli are demonstrated by the distribution of the velocity vector, isotherms and streamlines. The governing equations are solved efficiently by using a parallel implementation. The technique is adopted for reduction of the computation cost. The parallelization is performed with the domain decomposition technique and message passing between sub-domains on the basis of the MPI library. The results from parallel computation reveal in consistency with those of the sequential program. Moreover, the speed-up ratio shows linearity with the number of processor

  17. RECONHECENDO O VALOR DO COOPERATIVISMO SOB A ÓTICA DA CADEIA MEIOS-FINS

    Directory of Open Access Journals (Sweden)

    Agda Silva Prado

    2015-01-01

    Full Text Available As instituições cooperativistas são importantes promotoras do agronegócio brasileiro, pois através delas, pequenos, médios e grandes agricultores se unem para estabelecerem melhores condições de compra e venda de produtos. Entretanto, faz-se necessário averiguar mercadologicamente qual o valor das cooperativas para os cooperados, como forma de mantê-los unidos e proporcionar desenvolvimento para o setor. Assim, este trabalho tem como objetivo identificar a estrutura cognitiva de valor percebida pelos cooperados de uma cooperativa agropecuária no Sul de Minas Gerais. A pesquisa parte de uma abordagem qualitativa através da teoria de cadeia de meios-fins, utilizando o método de escalonamento laddering e a análise de conteúdo em 25 entrevistas em profundidade. Como resultados, identificou-se que os valores: tranquilidade, felicidade, realização, melhor qualidade de vida e sentimento de pertença são as principais motivações para a participação dos cooperados na cooperativa. Esse estudo contribui no desenvolvimento de pesquisas ligadas ao agronegócio, na compreensão de valores capazes de estimular o fortalecimento de ações cooperativistas e estratégias de marketing.

  18. Effect of fin pitch and number of tube rows on the air side performance of herringbone wavy fin and tube heat exchangers

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Chokeman, Yutasak

    2005-01-01

    An experimental study is conducted to investigate the effects of a fin pitch and number of tube rows on the air side performance of fin and tube heat exchangers having herringbone wavy fin configuration at various fin thicknesses. A total of 10 samples of fin and tube heat exchanger with a tube outside diameter of 9.53mm, transverse tube pitch of 25.4mm and longitudinal tube pitch of 19.05mm, having various fin pitches, number of tube rows and fin thicknesses, are tested in a well insulated open wind tunnel. The heat exchangers are made from aluminium plate finned, copper tube. Ambient air is used as a working fluid in the air side while hot water is used for the tube side. The results are presented as the variation of the Colburn factor and the friction factor with the Reynolds number based on the fin collar outside diameter (Re D c ). The experimental results reveal that the fin pitch has an insignificant effect on the heat transfer characteristic. The friction factor increases with increasing fin pitch when Re D c >2500, approximately. The Colburn factor and the friction factor decrease with increasing number of tube rows when Re D c <4000, approximately. These results remain the same when the fin thickness is changed

  19. Estudio del manejo de residuos sólidos en el Relleno Sanitario Doña Juana con el fin de delinear un borrador de propuesta para el manejo integral de residuos sólidos en la ciudad de Bogotá D.C

    OpenAIRE

    Anzola Parra, Diego Felipe

    2015-01-01

    Con el presente trabajo se busca realizar una propuesta de solución al sistema de manejo de los residuos sólidos urbanos en el relleno sanitario de Doña Juana en la ciudad de Bogotá, porque los desechos producidos por el consumo humano al no ser tratados de la forma correcta, afectan negativamente a la ciudad, rompen el cirulo vital del desarrollo y desequilibran el medio ambiente. Se realiza un diagnostico histórico al manejo de los residuos sólidos en la ciudad de Bogotá, para poder entende...

  20. Efetivação do enquadramento de corpos d’água para fins de consumo humano em regiões semiáridas: Avaliação conforme resolução CONAMA 357/2005 e portaria MS 2914/2011

    Directory of Open Access Journals (Sweden)

    Zuri Bao Pessôa

    2015-12-01

    Full Text Available A escassez hídrica é situação recorrente em regiões de clima semiárido devido às condições climáticas naturais e à crescente pressão antrópica, através do lançamento direto ou indireto de cargas poluentes nas calhas dos rios. Para destinação da água ao consumo humano, uso prioritário em momentos de escassez, a Resolução CONAMA 357/05 estabelece que a água deve apresentar minimamente qualidade equivalente à classe 03, na hipótese de águas doces, ou compatível com classe 01, em se tratando de águas salobras. A Portaria 2.914/11 do Ministério da Saúde estabelece o padrão de potabilidade da água, ou seja, atendendo-se aos valores definidos na Portaria MS 2914/11 a água pode ser prontamente consumida. De acordo com a Resolução CONAMA 357/05, por sua vez, mesmo nas classes com possibilidade de abastecimento humano, a água deve ser submetida a processo de tratamento. Ainda assim, a Resolução CONAMA 357/05 é, para determinados parâmetros, mais restritiva que a Portaria MS 2914/11, o que pode ser associado ao fato de que os padrões definidos devem atender a todos os usos para os quais as classes são destinadas, além do abastecimento humano. Resta evidente, portanto, que é necessário reavaliar o critério de enquadramento de corpos hídricos, principalmente em situações de escassez hídrica. Esse trabalho tem como objetivo comparar a possibilidade de destinação de corpos hídricos para abastecimento humano após a aplicação de ações de saneamento básico considerando a Resolução CONAMA 357/05 isoladamente e em conjunto com a Portaria MS 2914/11. Como área de estudo utilizou-se trecho do baixo Salitre, rio principal da Bacia Hidrográfica do Salitre, inserida na região semiárida e sub-bacia da Bacia Hidrográfica do rio São Francisco. Após a identificação das fontes de poluição predominantes no trecho, selecionaram-se ações de saneamento básico para abatimento da carga poluidora afluente

  1. Laser Welding Of Finned Tubes Made Of Austenitic Steels

    Directory of Open Access Journals (Sweden)

    Stolecki M.

    2015-09-01

    Full Text Available This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301 austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614, and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, one performed metallographic examinations, hardness measurements and a technological attempt to rupture the fin. Analysis of the results proved that the laser-welded finned tubes were performed correctly and that the welded joints had shown no imperfections.

  2. A thermal study of pipes with outer transverse fins

    Directory of Open Access Journals (Sweden)

    S. Gil

    2016-10-01

    Full Text Available This paper provides results of thermal investigations on pipes with outer transverse fins produced by placing a strip, being a form of helical spring which functions as a radiator, on the basis pipe. The investigations were carried out at the facility that enables measurements with respect to both natural and forced convection. Performance of the investigated pipes was assessed in relation to a non-finned pipe and a pipe welded with the use of Metal Active Gas (MAG technology. The experiments have shown that the finned pipe welding technology does not markedly affect their thermal efficiency, which has been confirmed by performed model calculations, while the welding technology has a crucial impact on their operating performance.

  3. Thermohydraulic analysis of smooth and finned annular ducts

    International Nuclear Information System (INIS)

    Braga, C.V.M.

    1987-01-01

    The present work is concerned with the turbulent heat transfer and pressure drop in smooth and finned annular ducts overage heat transfer coefficients have been obtained by means of the heat exchanger theory. In addition, friction factors have also been determined. The experiments were performed by utilizing four double-pipe heat exchangers. The flowing fluids, in the heat exchangers, were air and water. The average heat transfer coefficients, for air flowing in the annular section, were determined by measuring the overall heat transfer coefficients of the heat exchangers. In order to attain fully developed conditions, the heat exchangers had a starting length of 30 hydraulic diameters. The thermal boundary conditions consisted of uniform temperature on the inner surface, the outer surface being insulated. The heat transfer coefficients and friction factors are presented in dimensionaless forms, as functions of the Reynolds number of the flow. The results for the smooth and finned annular ducts were compared. The purpose of such comparison was to study the influence of the fins on the pressure drop and heat transfer rate. In the case of the finned nular ducts, it is shown that the fin efficiency has some fluence on the heat transfer rates. The, a two-dimensional at transfer analysis was performed in order to obtain the n efficiency and the annular region efficiency. It is also shown that the overall thermal performance of finned surfaces epends mainly on the Nusselt number and on the region eficiency. These parameters are presented as functions of the Reynolds number of the flow and the geometry of the problem. (author) [pt

  4. Experimental testing of the thermal performance of finned air coolers

    International Nuclear Information System (INIS)

    Imhof, A.; Keller, J.; Koelliker, A.

    1988-05-01

    Finned heat exchangers are often used as regenerators in heat recovery systems or as a heat source for heat pump installations. These exchangers are usually operating as air coolers. Heat is extracted from the air flowing through the heat exchanger. If the fin temperature lies below the dew point at the air inlet, water vapour may be condensed, increasing the thermal performance of the cooler. If the air/water heat exchanger is installed outdoors, the blower is usually mounted directly at the exchaner's case. In general this leads to non-ideal air flow conditions. For the sizing of such components the manufacturers dispose of design rules which are based either on theoretical models or on experiments using a uniform air stream. These rules which are mostly internal codes of the individual companies presumably do not take into account some non-ideal conditions such as an inhomogeneous air flow, a poorly sized blower or an increased pressure drop between the fins due to condensed water vapour. Moreover, these codes are possibly not sophisticated enough to enable a correct sizing of the products for any given condition of operation, especially in heat pumps operating under condensation conditions. Therfore, the Swiss Federal Institute for Reactor Research (EIR) carried out a research program dealing with the thermal performance of commercially available finned air coolers. The results give a strong evidence that the sizing of finned air coolers involving a phase change in one of the heat transfer fluids is not yet a procedure belonging to the common knowledge of most of the manufacturers. Moreover, the correct sizing of the blower is at least as important as the sizing of the finned exchanger itself. However, it is evident that there are companies on the Swiss market which use already reliable design tools. 25 refs., 81 figs., 12 tabs

  5. Fin Type Variation of Lionhead Strain Goldfish (Carassius auratus Offspring

    Directory of Open Access Journals (Sweden)

    M. Syaifudin

    2007-12-01

    Full Text Available  Lionhead strain goldfish (Carassius auratus inheritance produce many variations in phenotype qualitative traits of their offspring that is not common with the parents. Lionhead is an ornamental freshwater fish, they do not have a dorsal fin, but it is a beauty finfish, is popular to the people and have a high economic value. Of the 846 offspring of lionhead is produced in this experiment, and 57,7% of them have dorsal fin (42,3% normal, 13,1% of them have anal fin which did not similar with their parents, 58,6% caudal fin of them did not have similar to their parents. It might be caused by incompletely segregation in meiosis and many gen responsible to certain phenotype trait. Another abnormalities such as no anal fin, blindness, stumped and no pigmen in their gill lamella also occurred. Key words: Inheritance, fin, phenotype, abnormality   ABSTRAK Ikan maskoki strain lionhead menghasilkan keturunan dengan fenotip yang sangat bervariasi dan berbeda dengan induknya. Ikan ini merupakan ikan hias air tawar yang tidak memiliki sirip punggung namun tetap memiliki keindahan, sehingga menjadi begitu populer di masyarakat dan memiliki nilai ekonomi yang tinggi. Sebanyak 846 keturunan (anakan telah dihasilkan dalam percobaan ini, dan sebanyak 57,7% dari populasi tersebut memiliki sirip punggung (berarti 42,3% merupakan keturunan normal, 13,1% memiliki sirip dubur yang tidak mirip dengan induknya. Variasi keturunan ikan maskoki strain lionhead ini disebabkan oleh segregasi yang tidak sempurna dalam proses meiosis dan banyaknya gen yang terlibat dalam pembentukan penotip tertentu. Abnormalitas lainnya juga terjadi pada keturunan ikan maskoki strain lionhead ini, seperti tidak adanya sirip dubur, mata buta, tubuh pendek dan tidak adanya pigmen pada lemela insang Kata kunci: Keturunan, sirip, fenotip, abnormalitas  

  6. Integral finned heater and cooler for stirling engines

    Science.gov (United States)

    Corey, John A.

    1984-01-01

    A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

  7. Atom-probe for FinFET dopant characterization

    Energy Technology Data Exchange (ETDEWEB)

    Kambham, A.K., E-mail: kambham@imec.be [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W. [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

    2011-05-15

    With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10{sup o} and 45{sup o}) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: {yields} This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). {yields} Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. {yields} The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions

  8. Atom-probe for FinFET dopant characterization

    International Nuclear Information System (INIS)

    Kambham, A.K.; Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W.

    2011-01-01

    With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10 o and 45 o ) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: → This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). → Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. → The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions. → In this publication we

  9. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL FINS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2005-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal fins. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...

  10. Subcooled boiling heat transfer on a finned surface

    International Nuclear Information System (INIS)

    Kowalski, J.E.; Tran, V.T.; Mills, P.J.

    1992-01-01

    Experimental and numerical studies have been performed to determine the heat transfer coefficients from a finned cylindrical surface to subcooled boiling water. The heat transfer rates were measured in an annular test section consisting of an electrically heated fuel element simulator (FES) with eight longitudinal, rectangular fins enclosed in a glass tube. A two-dimensional finite-element heat transfer model using the Galerkin method was employed to determine the heat transfer coefficients along the periphery of the FES surface. An empirical correlation was developed to predict the heat transfer coefficients during subcooled boiling. The correlation agrees well with the measured data. (6 figures) (Author)

  11. Study on finned pipe performance as a ground heat exchanger

    Science.gov (United States)

    Lin, Qinglong; Ma, Jinghui; Shi, Lei

    2017-08-01

    The GHEs (ground heat exchangers) is an important element that determines the thermal efficiency of the entire ground-source heat-pump system. The aim of the present study is to clarify thermal performance of a new type GHE pipe, which consists straight fins of uniform cross sectional area. In this paper, GHE model is introduced and an analytical model of new type GHE pipe is developed. The heat exchange rate of BHEs utilizing finned pips is 40.42 W/m, which is 16.3% higher than normal BHEs, based on simulation analyses.

  12. Criteria for analysis and optimization of longitudinal fins with convective tip

    International Nuclear Information System (INIS)

    Gomes, E.S.

    1983-01-01

    The problem of heat transfer in longitudinal fins with the main geometries used in equipaments of heat transfer by convection is analyzed. The equation of energy is solved analytically of several geometries fins, with unidimensional formulation, through the use of the convective heat transfer coefficient. The problem of fin optimization is approached analytically yielding the parameters which allow the maximum heat transfer for each particular material waste in the fin. The use of the insulated tip model suggests the use of fins and its optimization for any Biot number of the fin. The use of the convective tip model allows us to determine when is vantageous or disadvantageous to use fins and when fin optimization is possible according to the value of the Biot number and to a convection parameter on the fin tip. (Author) [pt

  13. Pilarização de esmectita brasileira para fins catalíticos. Emprego de argila pilarizada na alquilação de benzeno com 1-dodeceno Pillarization of Brazilian smectite for the catalytic of purpose. Use of pillared clay in the alkylation of benzene with 1-dodecene

    Directory of Open Access Journals (Sweden)

    Sidnei Quezada M. Leite

    2000-04-01

    Full Text Available Al-pillared clay was prepared with a Brazilian bentonite from the Campina Grande region (Paraíba, BRAZIL. It was intercalated at 298 K, during 48 hours, with a solution containing [Al3+] = 0.10 mol/L and molar ratio OH/Al = 2.0 prepared at 333 K, and was calcined at 773K. The catalytic activity was evaluated by alkylation of benzene with 1-dodecene. The characterization methods were: X-ray fluorescence and diffraction analysis; 27Al, 29Si and 23Na MAS NMR and textural analysis by N2 adsorption. The thermal stability of the natural clay was improved by the pillaring procedure, as well as the catalytic activity. The intercalated clay presented the highest initial rate of reaction among the systems tested.

  14. GESTÃO DA ÁGUA EM USINA DE CONCRETO: ANALISE DO RISCO DAS ATIVIDADES E MONITORAMENTO DA QUALIDADE DA ÁGUA RESIDUÁRIA PARA FINS DE REUSO (DOI.:10.5216/reec.V10i1.32759

    Directory of Open Access Journals (Sweden)

    Heber Martins de Paula

    2015-07-01

    Full Text Available RESUMO: As usinas de concreto vêm enfrentando o desafio de aumentar a produção, reduzindo o volume de resíduos gerados. Suas principais atividades demandam de volumes consideráveis de água que, ao mesmo tempo, não devem ser descartadas no solo ou redes coletoras, pois podem gerar riscos ao meio ambiente. Assim, este artigo tem como objetivo avaliar a frequência e o risco das atividades da usina quanto ao uso da água. Além disso, monitorar a qualidade da água do sistema de tratamento quanto ao pH e a turbidez. Para tanto, foi aplicado o método de Avaliação de Risco da Atividade aliado a observações realizadas in loco para melhor representar as ações de um dia convencional de produção. O levantamento foi realizado por seis dias aleatórios por três semanas consecutivas. Para avaliação da qualidade da água residuária foram monitorados o pH e a turbidez, sempre no último dia de produção da usina, representando a pior situação. Os resultados mostraram que a lavagem dos caminhões é a atividade que apresenta maior risco ao meio ambiente, pois acontece com maior frequência dentro do espaço de produção. O sistema atual não consegue remover a turbidez para destinação da água ao reuso, mantendo o pH acima de 12. ABSTRACT: The concrete plants are facing the challenge of increasing production, reducing the volume of waste generated. Its main activities require considerable volumes of water at the same time, should not be dismissed on the ground or collecting networks, they could generate risks to the environment. Thus, this article aims to evaluate the frequency and risk of the activities of the concrete plant on the use of water. In addition, monitor the quality of water treatment system for pH and turbidity. To this end, we applied the method of the Activity Risk Assessment together with in situ observations to better represent the actions of a conventional production day. The survey was conducted by six random days

  15. Experimental Investigation on Effect of Fin Shape on the Thermal-Hydraulic Performance of Compact Fin-and-Tube Heat Exchangers

    Science.gov (United States)

    Moorthy, P.; Oumer, A. N.; Ishak, M.

    2018-03-01

    The aim of this paper is to investigate the effect of fin shapes on the performance of compact finned flat tube heat exchangers. Three types of fin shapes namely plain, wavy, and rectangular grooved fins attached to three by three arrays of flat tube banks were considered. Moreover, the tubes were deployed in in-line and staggered arrangements. In addition to the fin shapes, the air velocity and the tube inclination angles were varied and the thermal-hydraulic performance was analysed. On the other hand, the temperatures at the tube surfaces were kept constant to produce constant heat flux throughout the study. The results showed that as flowrate increases, the heat transfer increases, however, the friction factor decreases. Staggered arrangement produces higher heat transfer and friction factor than inline fin. Moreover, the rectangular fin is the best in terms of high heat transfer however the drawback of high friction factor leads the fin to have the least efficiency of all. On the other hand, plain fin had the least heat transfer performance however the highest efficiency was achieved. Therefore, plain fin should be used when efficiency is prioritized and rectangular fin when high heat transfer is desired.

  16. Numerical study of an innovative design of a finned double-pipe heat exchanger with variable fin-tip thickness

    International Nuclear Information System (INIS)

    Syed, K.S.; Ishaq, Muhammad; Iqbal, Zafar; Hassan, Ahmad

    2015-01-01

    Highlights: • Variable fin tip angle significantly effect the velocity and temperature distribution. • Significant gain in the thermal performance with decrease in the friction factor. • Variable fin tip angle must be considered an important parameter in designing finned annulus. - Abstract: The analysis of fully developed laminar convective heat transfer in an innovate design of a finned double-pipe heat exchanger (DPHE) with longitudinal fins of variable thickness of the tip subjected to the constant heat transfer rate boundary conditions is investigated here. The tip thickness is controlled by the ratio of tip to base angles as a parameter whose values varying from 0 to 1 correspond to the fin shapes varying from the triangular to the rectangular cross-section. Upto the knowledge of the authors, this parameter is being introduced for the first time in the literature. Discontinuous Galerkin finite element method (DG-FEM) has been employed in the present work. The overall performance of the proposed DPHE has been investigated by considering the friction factor, the Nusselt number and the j-factor. Upto 178% gain in the Nusselt number and 89% gain in the j-factor have been achieved relative to the rectangular cross-section. Such gains relative to the triangular cross-section are respectively 9.5% and 19%. The results indicate that the newly introduced parameter the ratio of tip to base angles has proved to play significant role in the design of a double-pipe heat exchanger in reducing the cost, weight and frictional loss, in improving the heat transfer rate and making the exchanger energy-efficient. Therefore, it must be considered as an important design parameter for heat exchanger design

  17. Necropsy report of a fin whale (Balaenoptera physalus) stranded in Denmark in 2010

    DEFF Research Database (Denmark)

    Alstrup, Aage K. O.; Hedayat, Abdi; Jensen, Trine Hammer

    2013-01-01

    There is little detailed information on stranded fin whales (Balaenoptera physalus) in the scientific literature (Notarbartolo di Sciara et al., 2003). In Denmark, at least eight fin whales stranded between the years 1603 and 1958 (Kinze, 1995). On 16 June 2010, a live subadult or adult male fin...... whale stranded in the Bay of Vejle (55º 69' N, 9º 58' E), Denmark. Despite several attempts, it was not possible to rescue the fin whale, which was only partially exposed by the water. The fin whale succumbed after 5 d stranded in shallow water. The dead fin whale was transported to a nearby pier...

  18. Numerical Modeling of Transient Heat Transfer in Longitudinal Fin

    Directory of Open Access Journals (Sweden)

    Farshad Panahizadeh

    2017-11-01

    Full Text Available The main objective of the present numerical study is to investigate the transient heat transfer in one kind of all-purpose longitudinal fin with the triangular profile. The lateral surface of the concerned fin and the tip of it are subjected to general situations included heat flux at the base and insulation on the tip. For this study developed a one dimensional in house code written by Fortran 90 programming language by using finite difference method with an implicit scheme in unsteady state condition. Generally, the result of this study in time variation state after 700 seconds is steady. The results also show the fin efficiency by increasing the time of study decreases due to a reduction in the total heat transfer which is happened in the fin. The grid independence study shows that for the number of nodes greater than 20 the result will not be changed and same as before. Finally, the result of Fortran code verified by commercial CFD code which relies on finite difference method and it was shown have a consistent agreement

  19. Los Grammy Latino, su meta inicial y su fin comercial

    Directory of Open Access Journals (Sweden)

    Marinés Arroyo Sotomayor

    2015-01-01

    Full Text Available El artículo refiere lo que es este festival musical que premia el talento latino, quienes participan, su meta inicial y su fin comercial. Muestra que a pesar de la tradición de intolerancia del exilio cubano, la música sirvió, una vez más, como puente de cultura

  20. First integrals and analytical solutions of the nonlinear fin problem ...

    Indian Academy of Sciences (India)

    2016-07-06

    Jul 6, 2016 ... As stated in [3,4], in the engineering applications, fins are used to facilitate .... This method can be applied when the differential equa- tion does not have a ... method is extended to fractional differential equations. [16]. Now, we ...

  1. Eddy current test of fin tubes for a heat exchanger

    International Nuclear Information System (INIS)

    KIm, Young Joo; Lee, Se Kyung; Chung, Min Hwa

    1992-01-01

    Eddy current probes were designed for the test of fin tubes. Fin tubes, often used for heat exchangers, have uneven outer and inner surfaces to enhance the heat emission. The surface roughness make it difficult to detect flaws employing eddy current test(ECT). In order to overcome the difficulties we performed two types of works, one is the delopment of ECT probes, and the other is the signal processing including fast Fourier transform and digital filtering. In the development of ECT probes, we adopted empirical design method. Our ECT probes for fin tubes are inside diameter type. And we are specially concerned about geometric features such as the widths of the coils composing an ECT probe. We fabricated four probes with various coil widths. Eddy current test was performed using those ECT probes on specimens with artificial flaws. After analyzing the output signals, we found that, in order for the effective testing, the width of a coil should be determined considering the pitch of the fins of a tube. And we also learned that the frequency filtering could improve the s/n ratio.

  2. Transfer coefficients in elliptical tubes and plate fin heat exchangers

    International Nuclear Information System (INIS)

    Saboya, S.M.

    1979-09-01

    Mean transfer coefficients in elliptical tubes and plate fin heat exchangers were determined by application of heat and mass transfer analogy in conjunction with the naphthalene sublimation technique. The transfer coefficients are presented in a dimensionless form as functions of the Reynolds number. By using the least squares method analytical expressions for the transfer coefficients were determined with low scattering. (E.G.) [pt

  3. Flexible nanoscale high-performance FinFETs

    KAUST Repository

    Sevilla, Galo T.; Ghoneim, Mohamed T.; Fahad, Hossain M.; Rojas, Jhonathan Prieto; Hussain, Aftab M.; Hussain, Muhammad Mustafa

    2014-01-01

    With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show

  4. Open Channel Natural Convection Heat Transfer on a Vertical Finned Plate

    International Nuclear Information System (INIS)

    Park, Joo Hyun; Heo, Jeong Hwan; Chung, Bum Jin

    2013-01-01

    The natural convection heat transfer of vertical plate fin was investigated experimentally. Heat transfer systems were replaced by mass-transfer systems, based on the analogy concept. The experimental results lie within the predictions of the existing heat transfer correlations of plate-fin for the natural convections. An overlapped thermal boundary layers caused increasing heat transfer, and an overlapped momentum boundary layers caused decreasing heat transfer. As the fin height increases, heat transfer was enhanced due to increased inflow from the open side of the fin spacing. When fin spacing and fin height are large, heat transfer was unaffected by the fin spacing and fin height. Passive cooling by natural convection becomes more and more important for the nuclear systems as the station black out really happened at the Fukushima NPPs. In the RCCS (Reactor Cavity Cooling System) of a VHTR (Very High Temperature Reactor), natural convection cooling through duct system is adopted. In response to the stack failure event, extra cooling capacity adopting the fin array has to be investigated. The finned plate increases the surface area and the heat transfer increases. However, the plate of fin arrays may increase the pressure drop and the heat transfer decreases. Therefore, in order to enhance the passive cooling with fin arrays, the parameters for the fin arrays should be optimized. According to Welling and Wooldridge, a natural convection on vertical plate fin is function of Gr, Pr, L, t, S, and H. The present work investigated the natural convection heat transfer of a vertical finned plate with varying the fin height and the fin spacing. In order achieve high Rayleigh numbers, an electroplating system was employed and the mass transfer rates were measured using a copper sulfate electroplating system based on the analogy concept

  5. Plant Measurement, Sampling and Analysis for Accountancy Purposes with Particular Reference to Separation Plants at Windscale; Mesures, Echantillonnages et Analyses en Usine a des Fins Comptables, Notamment dans les Installations de Separation de Windscale; Izmereniya, vzyatie obraztsov i analizy v tselyakh ucheta na opyte ustanovki razdeleniya radioizotopov v uindskejle; Medicion, Muestreo y Analisis para Fines Contables, Especialmente en las Plantas de Separacion de Windscale

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, A. S.; Elliott, F.; Powell, R.; Swinburn, K. A. [United Kingdom Atomic Energy Authority, Windscale and Calder Works, Cumberland (United Kingdom)

    1966-02-15

    ) titrimetrie, e) dilution isotopique suivie de spectrometrie de masse, et f) spectrometrie differentielle. Ils soulignent egalement les methodes de dosage de l'uranium, notamment les suivantes: a) gravimetrie de U{sub 3}O{sub 8}. b) extraction a l ' ether suivie de gravimetrie ou de colorimetrie, c) titrimetrie, d) dilution isotopique suivie de spectrometrie de masse, et e) determination de l'enrichissement par spectrometrie de masse ou spectrographie des emissions accompagnees d'un deplacement des raies. Pour toutes les methodes comptables, on utilise des etalons pour assurer le controle de la qualite et faire ressortir toute inexactitude qu'il est necessaire de corriger. Les auteurs indiquent la precision de chaque methode et enumerent les methodes effectivement utilisees dans la nouvelle usine de separation. (author) [Spanish] Todas las cifras destinadas a la contabilidad de materiales especiales corresponden por lo menos a uno de los tres parametros siguientes: medicion en la planta, muestreo y analisis. Para las mediciones en la planta conviene emplear la pesada siempre que sea posible; por ejemplo, la cantidad de plutonio que entra en la nueva planta de separacion de Windscale se calcula a base del peso de las barras de uranio. Los autores exponen los metodos de medicion de volumenes: a) 'pneumercator', y b) empleo de cesio radiactivo como indicador, y evaluan la exactitud y precision de cada uno de esos metodos. El muestreo de soluciones en un proceso intermitente se efectua con tubos evacuados despues de homogeneizar la solucion. Para las corrientes 'continuas' , que requieren mucha exactitud, se ha ideado un dispositivo de muestreo continuo que se emplea a la entrada de la nueva planta de separacion. En Windscale, el metodo normal de muestreo consiste en taladrar lingotes metalicos; para otros solidos se sigue la practica de homogeneizar todo lo posible el material antes de tomar la muestra (para el oxido de plutonio, por ejemplo, se emplea una mezcladora conica en Y

  6. Enhancement of heat transfer from a continuously moving porous fin exposed in convective–radiative environment

    International Nuclear Information System (INIS)

    Bhanja, Dipankar; Kundu, Balaram; Aziz, Abdul

    2014-01-01

    Highlights: • Analytical model for thermal analysis of moving porous fins. • Heat transfer from the fin surface due to convection and radiation. • For practical design aspects, optimization analysis was carried out. • Comparative study was made between the solid and porous moving fins. • Porous moving fin has more heat transfer ability than the stationary fin. - Abstract: In the present article, an exercise has been devoted to establish an analytical model for the determination of temperature distribution, fin efficiency and optimum design parameters of a porous moving fin which is losing heat by simultaneous convection and radiation to its surroundings. For the adaptation of this consideration, the governing equation becomes highly nonlinear. An analytical technique called Adomian decomposition method (ADM) is proposed for the solution methodology. The accuracy of the analytic solution is validated by using a numeric scheme called finite difference method. The results indicate that the numerical data and analytical approach are in agreement with each other. As the present study is an analytic, it is extended to the analysis for determination of optimum dimensions of said fin by satisfying either the maximization of rate of heat transfer for a given fin volume or by the minimization of fin volume for a desired heat transfer rate. The study is further extended to the porous fin in stationary condition and it is found that porous fin in moving condition transfers more heat than stationary condition. Investigation has also been made on solid moving fin to compare the outcomes of these parameters

  7. The Cx43-like connexin protein Cx40.8 is differentially localized during fin ontogeny and fin regeneration.

    Directory of Open Access Journals (Sweden)

    Sarah V Gerhart

    Full Text Available Connexins (Cx are the subunits of gap junctions, membraneous protein channels that permit the exchange of small molecules between adjacent cells. Cx43 is required for cell proliferation in the zebrafish caudal fin. Previously, we found that a Cx43-like connexin, cx40.8, is co-expressed with cx43 in the population of proliferating cells during fin regeneration. Here we demonstrate that Cx40.8 exhibits novel differential subcellular localization in vivo, depending on the growth status of the fin. During fin ontogeny, Cx40.8 is found at the plasma membrane, but Cx40.8 is retained in the Golgi apparatus during regeneration. We next identified a 30 amino acid domain of Cx40.8 responsible for its dynamic localization. One possible explanation for the differential localization is that Cx40.8 contributes to the regulation of Cx43 in vivo, perhaps modifying channel activity during ontogenetic growth. However, we find that the voltage-gating properties of Cx40.8 are similar to Cx43. Together our findings reveal that Cx40.8 exhibits differential subcellular localization in vivo, dependent on a discrete domain in its carboxy terminus. We suggest that the dynamic localization of Cx40.8 differentially influences Cx43-dependent cell proliferation during ontogeny and regeneration.

  8. Chromium Is Elevated in Fin Whale (Balaenoptera physalus) Skin Tissue and Is Genotoxic to Fin Whale Skin Cells

    Science.gov (United States)

    Wise, Catherine F.; Wise, Sandra S.; Thompson, W. Douglas; Perkins, Christopher; Wise, John Pierce

    2015-01-01

    Hexavalent chromium (Cr(VI)) is present in the marine environment and is a known carcinogen and reproductive toxicant. Cr(VI) is the form of chromium that is well absorbed through the cell membrane. It is also the most prevalent form in seawater. We measured the total Cr levels in skin biopsies obtained from healthy free-ranging fin whales from the Gulf of Maine and found elevated levels relative to marine mammals in other parts of the world. The levels in fin whale biopsies ranged from 1.71 ug/g to 19.6 ug/g with an average level of 10.07 ug/g. We also measured the cytotoxicity and genotoxicity of Cr(VI) in fin whale skin cells. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to fin whale skin cells in a concentration-dependent manner. The concentration range used in our cell culture studies used environmentally relevant concentrations based on the biopsy measurements. These data suggest that Cr(VI) may be a concern for whales in the Gulf of Maine. PMID:25805270

  9. Actuation of a robotic fish caudal fin for low reaction torque

    Science.gov (United States)

    Yun, Dongwon; Kim, Kyung-Soo; Kim, Soohyun; Kyung, Jinho; Lee, Sunghee

    2011-07-01

    In this paper, a novel caudal fin for actuating a robotic fish is presented. The proposed caudal fin waves in a vertical direction with a specific spatial shape, which is determined by a so-called shape factor. For a specific shape factor, a traveling wave with a vertical phase difference is formed on a caudal fin during fin motion. It will be shown by the analysis that the maximum reaction torque at the joint of a caudal fin varies depending on the shape factors. Compared with a conventional plate type caudal fin, the proposed fin with a shape factor of 2π can eliminate the reaction torque perfectly, while keeping the propulsion force unchanged. The benefits of the proposed fin will be demonstrated by experiments.

  10. Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

    Directory of Open Access Journals (Sweden)

    Fengming Wang

    2012-12-01

    Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

  11. Constructal design of finned tubes used in air-cooled heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Shokouhmand, Hossein; Mahjoub, Shoeib [University of Tehran, Tehran (Iran, Islamic Republic of); Salimpour, Mohammad Reza [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2014-06-15

    The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

  12. Constructal design of finned tubes used in air-cooled heat exchangers

    International Nuclear Information System (INIS)

    Shokouhmand, Hossein; Mahjoub, Shoeib; Salimpour, Mohammad Reza

    2014-01-01

    The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

  13. Relationships of mercury concentrations across tissue types, muscle regions and fins for two shark species

    KAUST Repository

    O'Bryhim, Jason R.; Adams, Douglas H.; Spaet, Julia L.; Mills, Gary; Lance, Stacey L.

    2017-01-01

    mercury (THg) concentrations from eight muscle regions, four fins (first dorsal, left and right pectorals, caudal-from both the inner core and trailing margin of each fin), and five internal organs (liver, kidney, spleen, heart, epigonal organ) from two

  14. Modelo de negocio para bebidas funcionales Ceiba

    OpenAIRE

    Gil Giraldo, Jhonatan; Restrepo Mesa, Juan Eduardo

    2017-01-01

    El presente documento, modelo de negocio para bebidas naturales Ceiba, es el trabajo de grado realizado por los autores con el fin de optar al título de magíster en Administración (MBA) de la Universidad EAFIT -- El cual esta soportado en los diferentes conceptos y metodologías de modelo de negocio y planes de negocio -- Por tratarse de un prototipo que busca definir los elementos estratégicos necesarios para su desarrollo, arrojó como resultado que la metodología más adecuada para ser aplica...

  15. Note: Dynamic analysis of a robotic fish motion with a caudal fin with vertical phase differences

    Science.gov (United States)

    Yun, Dongwon; Kim, Kyung-Soo; Kim, Soohyun; Kyung, Jinho; Lee, Sunghwi

    2013-03-01

    In this paper, a robotic fish with a caudal fin with vertical phase differences is studied, especially focusing on the energy consumption. Energies for thrusting a conventional robotic fish and one with caudal fin with vertical phase differences are obtained and compared each other. It is shown that a robotic fish with a caudal fin with vertical phase differences can save more energy, which implies the efficient thrusting via a vertically waving caudal fin.

  16. Optimization of Peripheral Finned-Tube Evaporators Using Entropy Generation Minimization

    OpenAIRE

    Pussoli, Bruno; Barbosa Jr., Jader; da Silva, Luciana; Kaviany, Massoud

    2012-01-01

    The peripheral finned-tube (PFT) is a new geometry for enhanced air-side heat transfer under moisture condensate blockage (evaporators). It consists of individual hexagonal (peripheral) fin arrangements with radial fins whose bases are attached to the tubes and tips are interconnected with the peripheral fins. In this paper, experimentally validated semi-empirical models for the air-side heat transfer and pressure drop are combined with the entropy generation minimization theory to determine ...

  17. Effect of Collector Aspect Ratio on the Thermal Performance of Wavy Finned Absorber Solar Air Heater

    OpenAIRE

    Abhishek Priyam; Prabha Chand

    2016-01-01

    A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent hig...

  18. FinTech transformation: how it-enabled innovations shape the financial sector

    OpenAIRE

    Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

    2016-01-01

    FinTech, the phenomenon which spans over the areas of information technologies and financial innovation, is currently on the rise and is gaining more and more attention from practitioners, investors and researchers. FinTech is broadly discussed by the media, which constitutes its understanding and represents social opinion, however, this perception of FinTech should be supported by empirical evidences. Therefore, we examine five Swiss FinTech companies through the lens of the conceptual frame...

  19. Performance measurement of plate fin heat exchanger by exploration: ANN, ANFIS, GA, and SA

    OpenAIRE

    A.K. Gupta; P. Kumar; R.K. Sahoo; A.K. Sahu; S.K. Sarangi

    2017-01-01

    An experimental work is conducted on counter flow plate fin compact heat exchanger using offset strip fin under different mass flow rates. The training, testing, and validation set of data has been collected by conducting experiments. Next, artificial neural network merged with Genetic Algorithm (GA) utilized to measure the performance of plate-fin compact heat exchanger. The main aim of present research is to measure the performance of plate-fin compact heat exchanger and to provide full exp...

  20. Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage

    OpenAIRE

    Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

    2014-01-01

    In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and ...

  1. Effect of storage media and time on fin explants culture in the ...

    African Journals Online (AJOL)

    The effect of storage media and time was investigated on fin explants culture in the goldfish (Carassius auratus). Fin explants under sterile conditions were able to produce cells at different storage media and time. On the outgrowth of cells, fin explants stored for seven days before culturing showed significantly higher growth ...

  2. Velocity Deficits in the Wake of Model Lemon Shark Dorsal Fins Measured with Particle Image Velocimetry

    Science.gov (United States)

    Terry, K. N.; Turner, V.; Hackett, E.

    2017-12-01

    Aquatic animals' morphology provides inspiration for human technological developments, as their bodies have evolved and become adapted for efficient swimming. Lemon sharks exhibit a uniquely large second dorsal fin that is nearly the same size as the first fin, the hydrodynamic role of which is unknown. This experimental study looks at the drag forces on a scale model of the Lemon shark's unique two-fin configuration in comparison to drag forces on a more typical one-fin configuration. The experiments were performed in a recirculating water flume, where the wakes behind the scale models are measured using particle image velocimetry. The experiments are performed at three different flow speeds for both fin configurations. The measured instantaneous 2D distributions of the streamwise and wall-normal velocity components are ensemble averaged to generate streamwise velocity vertical profiles. In addition, velocity deficit profiles are computed from the difference between these mean streamwise velocity profiles and the free stream velocity, which is computed based on measured flow rates during the experiments. Results show that the mean velocities behind the fin and near the fin tip are smallest and increase as the streamwise distance from the fin tip increases. The magnitude of velocity deficits increases with increasing flow speed for both fin configurations, but at all flow speeds, the two-fin configurations generate larger velocity deficits than the one-fin configurations. Because the velocity deficit is directly proportional to the drag force, these results suggest that the two-fin configuration produces more drag.

  3. Externally finned circular tube immerse in a phase-change material

    International Nuclear Information System (INIS)

    Alves, C.L.F.; Ismail, K.A.R.

    1985-01-01

    In an attempt to increase the heat transfer rate and reduce the convective currents during the freezing of phase change materials (PCM) in storage tanks, externally finned circular tubes are studied experimentally. The parameters analysed in this work include number of fins, fin length, initial degree of superheat and freezing time

  4. Single basin solar still with fin for enhancing productivity

    International Nuclear Information System (INIS)

    Velmurugan, V.; Gopalakrishnan, M.; Raghu, R.; Srithar, K.

    2008-01-01

    Distilled water productivity of the single basin solar still is very low. In this work, to augment evaporation of the still basin water, fins were integrated at the basin of the still. Thus production rate accelerated. Also, for further increase in exposure area sponges were used. Experimental results were compared with ordinary basin type still and still with wicks. The governing energy balance equations were solved analytically and compared with experimental results. It was found that 29.6% productivity increased, when wick type solar still was used, 15.3% productivity increased when sponges were used and 45.5% increased when fins were used. A good agreement had been achieved with theoretical results

  5. Multiphysics Numerical Modeling of a Fin and Tube Heat Exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2015-01-01

    In the present research work, a modeling effort to predict the performance of a liquid-gas type fin and tube heat exchanger design is made. Three dimensional (3D) steady state numerical model is developed using commercial software COMSOL Multiphysics based on finite element method (FEM......). For the purposes here, only gas flowing over the fin side is simulated assuming constant inner tube wall temperature. The study couples conjugate heat transfer mechanism with turbulent flow in order to describe the temperature and velocity profile. In addition, performance characteristics of the heat exchanger...... design in terms of heat transfer and pressure loss are determined by parameters such as overall heat transfer coefficient, Colburn j-factor, flow resistance factor, and efficiency index. The model provides useful insights necessary for optimization of heat exchanger design....

  6. Ceramic finned-plate recuperator for industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, M.; Strumpf, H.; Kotchick, D.

    1985-01-01

    High-level recuperation of high-temperature industrial furnaces offers an economically effective means for improving both process and fuel utilization. A ceramic recuperator capable of operating in fuel gas temperatures of up to 1350/sup 0/C and providing a combustion air preheat temperature of 1100/sup 0/C can provide in excess of 50 percent savings in fuel comsumption over an unrecuperated furnace. This recuperator consists of an array of cast ceramic finned plates. The fin geometries are such that when the plates are stacked together, they form the heat transfer flow passages for both the flue gas and combustion air streams. A reference design for industrial recuperator system was created. The current development efforts conducted on this recuperator concept, as well as plans for future activities, are described.

  7. Desalination of effluent using fin type solar still

    Energy Technology Data Exchange (ETDEWEB)

    Velmurugan, V. [Department of Mechanical Engineering, Infant Jesus College of Engineering, Thoothukudi, Tamil Nadu 628 851 (India); Deenadayalan, C.K.; Vinod, H.; Srithar, K. [Department of Mechanical Engineering, Thiagarajar College of Engineering, Madurai, Tamil Nadu 625 015 (India)

    2008-11-15

    In this work, an attempt is made to produce potable water from industrial effluents. An ordinary basin type solar still integrated with fins at the basin plate is used for experimentation. Since industrial effluent is used as feed, before this still, an effluent settling tank is provided to get clarified effluent. This effluent settling tank is fabricated with three chambers, consists of pebble, coal and sand for settling the impurities and removing the bacteria in the effluents. Sponges, pebbles, black rubber and sand are used in the fin type single basin solar still for enhancing the yield. Results show that the productivity increases considerably due to this modification. A theoretical analysis is also carried out which, closely converges with experimental results. The economic analysis proved that the approximate payback period of such kinds of still is 1 year. (author)

  8. BAT摩拳擦掌布局FinTech

    Institute of Scientific and Technical Information of China (English)

    薛健

    2016-01-01

    数据显示,2015年亚太区FinTech领域投资额的90%集中在中国,而BAT等互联网巨头则参与投资了40%以上的项目。花旗发布的一份研究报告显示,中国FinTech公司的用户数已经等同甚至超越中国最大的银行,并且"主要归因于阿里、百度、腾讯等互联网巨头在电子商务、第三方支付、网络借贷上的努力"。

  9. FinTech in Taiwan: a case study of a Bank's strategic planning for an investment in a FinTech company

    OpenAIRE

    Hung, Jui-long; Luo, Binjie

    2016-01-01

    Introduction: Since 2015 is the year of FinTech in Taiwan, it is worth investigating the challenges that emerged when banks were encouraged to invest in FinTech companies for collaboration. This study aims to identify the strategic considerations in the process of searching for FinTech investment targets. Case description: This study used a case study investigation of a top-5 bank in Taiwan. The major data sources include the meeting notes of the FinTech investment task force and interviews w...

  10. Saddle-fin cell transistors with oxide etch rate control by using tilted ion implantation (TIS-fin) for sub-50-nm DRAMs

    International Nuclear Information System (INIS)

    Yoo, Min Soo; Choi, Kang Sik; Sun, Woo Kyung

    2010-01-01

    As DRAM cell pitch size decreases, the need for a high performance transistor is increasing. Though saddle-fin (S-fin) transistors have superior characteristics, S-fin transistors are well known to be more sensitive to process variation. To make uniform S-fin transistors, for the first time, we developed a new fin formation method using tilted ion implantation along the wordline direction after a recess gate etch. Due to the increased etch rate of the oxide film by ion implantation damage, fins are made at the bottom channel of the recess gate after wet etching. The resulting tilt implanted saddle-fin (TIS-fin) transistor has remarkably improved characteristics, such as ∼8% subthreshold swing (SS) and a 40% drain induced barrier lowering (DIBL) decrease. Especially, the TIS-fin with a neutral dopant has a reduced threshold voltage (Vth) variation within a wafer (<100 mV), which is comparable with that of a mass-produced sphere-shaped recessed channel array transistor (SRCAT).

  11. Optimization of fin geometry in heat convection with entransy theory

    International Nuclear Information System (INIS)

    Cheng Xue-Tao; Xu Xiang-Hua; Liang Xin-Gang; Zhang Qin-Zhao

    2013-01-01

    The entransy theory developed in recent years is used to optimize the aspect ratio of a plate fin in heat convection. Based on a two-dimensional model, the theoretical analysis shows that the minimum thermal resistance defined with the concept of entransy dissipation corresponds to the maximum heat transfer rate when the temperature of the heating surface is fixed. On the other hand, when the heat flux of the heating surface is fixed, the minimum thermal resistance corresponds to the minimum average temperature of the heating surface. The entropy optimization is also given for the heat transfer processes. It is observed that the minimum entropy generation, the minimum entropy generation number, and the minimum revised entropy generation number do not always correspond to the best heat transfer performance. In addition, the influence factors on the optimized aspect ratio of the plate fin are also discussed. The optimized ratio decreases with the enhancement of heat convection, while it increases with fin thermal conductivity increasing. (general)

  12. High performance flexible CMOS SOI FinFETs

    KAUST Repository

    Fahad, Hossain M.

    2014-06-01

    We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due to the reduction in off-state leakage and reduced short channel effects on account of the superior electrostatic charge control of multiple gates. At the same time, flexible electronics is an exciting expansion opportunity for next generation electronics. However, a fully integrated low-cost system will need to maintain ultra-large-scale-integration density, high performance and reliability - same as today\\'s traditional electronics. Up until recently, this field has been mainly dominated by very weak performance organic electronics enabled by low temperature processes, conducive to low melting point plastics. Now however, we show the world\\'s highest performing flexible version of 3D FinFET CMOS using a state-of-the-art CMOS compatible fabrication technique for high performance ultra-mobile consumer applications with stylish design. © 2014 IEEE.

  13. The FLUFF code for calculating finned surface heat transfer -description and user's guide

    International Nuclear Information System (INIS)

    Fry, C.J.

    1985-08-01

    FLUFF is a computer code for calculating heat transfer from finned surfaces by convection and radiation. It can also represent heat transfer by radiation to a partially emitting and absorbing medium within the fin cavity. The FLUFF code is useful not only for studying the behaviour of finned surfaces but also for deriving heat fluxes which can be applied as boundary conditions to other heat transfer codes. In this way models of bodies with finned surfaces may be greatly simplified since the fins need not be explicitly represented. (author)

  14. Armamento é Direitos Humanos: nossos fins, os meios e seus modos

    Directory of Open Access Journals (Sweden)

    Jacqueline de Oliveira Muniz

    2013-04-01

    Full Text Available A definição da capacidade coercitiva da polícia é a condição de possibilidade de sua instrumentalidade política para a defesa dos Direitos Humanos, bem como de sua governança. Após uma apresentação que consolida a teorização sobre o uso de força para a produção de obediências consentidas, apresentam-se três passagens históricas que correspondem aos momentos fundacionais das polícias modernas como ilustrações das alternativas de definição de tal capacidade, exemplificando diferentes formas de se conectar fins e meios, preferências políticas e especificidade de armamentos. As questões que essas exposições suscitam permitem apresentar duas considerações relevantes para o debate brasileiro sobre segurança pública: a tensão entre universalidade e localismo no instrumento policial, e a integralidade de fins e meios em duas instâncias em que o uso de força pode ter lugar - a defesa e a segurança pública.The definition of the coercive capacity of the police is the condition of possibility for its political instrumentality as well as its governance. After a presentation that consolidates the theorization of the use of force for the production of consented obediences, the article presents three passages of foundational moments of modern police forces as illustrations of the alternative ways of defining that capability as examples of different ways of connecting ends and means, political preferences and weapons specifics. The issues that these bring about allow the presentation of two issues relevant to the brazilian debate on public security: the tension between universality and localism in the police instrument and the integral nature of ends and means in two instances which admit the possibility of the use of force - defense and public security.

  15. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    International Nuclear Information System (INIS)

    Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

    1981-01-01

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial

  16. Heat transfer enhancement for fin-tube heat exchanger using vortex generators

    International Nuclear Information System (INIS)

    Yoo, Seong Yeon; Park, Dong Seong; Chung, Min Ho; Lee, Sang Yun

    2002-01-01

    Vortex generators are fabricated on the fin surface of a fin-tube heat exchanger to augment the convective heat transfer. In addition to horseshoe vortices formed naturally around the tube of the fin-tube heat exchanger, longitudinal vortices are artificially created on the fin surface by vortex generators. The purpose of this study is to investigate the local heat transfer phenomena in the fin-tube heat exchangers with and without vortex generators, and to evaluate the effect of vortices on the heat transfer enhancement. Naphthalene sublimation technique is employed to measure local mass transfer coefficients, then analogy equation between heat and mass transfer is used to calculate heat transfer coefficients. Experiments are performed for the model of fin-circular tube heat exchangers with and without vortex generators, and of fin-flat tube heat exchangers with and without vortex generators. Average heat transfer coefficients of fin-flat tube heat exchanger without vortex generator are much lower than those of fin-circular tube heat exchanger. On the other hand, fin-flat tube heat exchanger with vortex generators has much higher heat transfer value than conventional fin-circular tube heat exchanger. At the same time, pressure losses for four types of heat exchanger is measured and compared

  17. A successful application of homotopy perturbation method for efficiency and effectiveness assessment of longitudinal porous fins

    International Nuclear Information System (INIS)

    Cuce, Erdem; Cuce, Pinar Mert

    2015-01-01

    Highlights: • Homotopy perturbation method has been applied to porous fins. • Dimensionless efficiency and effectiveness expressions have been firstly developed. • Effects of porous and convection parameters on thermal analysis have been clarified. • Ratio of porous fin to solid fin heat transfer rate has been given for various cases. • Reliability and practicality of homotopy perturbation method has been illustrated. - Abstract: In our previous works, thermal performance of straight fins with both constant and temperature-dependent thermal conductivity has been investigated in detail and dimensionless analytical expressions of fin efficiency and fin effectiveness have been developed for the first time in literature via homotopy perturbation method. In this study, previous works have been extended to porous fins. Governing equations have been formulated by performing Darcy’s model. Dimensionless temperature distribution along the length of porous fin has been determined as a function of porosity and convection parameters. The ratio of porous fin to solid fin heat transfer rate has also been evaluated as a function of thermo-geometric fin parameter. The results have been compared with those of finite difference method for a specific case and an excellent agreement has been observed. The expressions developed are beneficial for thermal engineers for preliminary assessment of thermophysical systems instead of consuming time in heat conduction problems governed by strongly nonlinear differential equations

  18. The Influence of Culture on the International Management of Shark Finning

    Science.gov (United States)

    Dell'Apa, Andrea; Chad Smith, M.; Kaneshiro-Pineiro, Mahealani Y.

    2014-08-01

    Shark finning is prohibited in many countries, but high prices for fins from the Asian market help maintain the international black-market and poaching. Traditional shark fin bans fail to recognize that the main driver of fin exploitation is linked to cultural beliefs about sharks in traditional Chinese culture. Therefore, shark finning should be addressed considering the social science approach as part of the fishery management scheme. This paper investigates the cultural significance of sharks in traditional Chinese and Hawaiian cultures, as valuable examples of how specific differences in cultural beliefs can drive individuals' attitudes toward the property of shark finning. We suggest the use of a social science approach that can be useful in the design of successful education campaigns to help change individuals' attitudes toward shark fin consumption. Finally, alternative management strategies for commercial fishers are provided to maintain self-sustainability of local coastal communities.

  19. Flow-structure Interaction Modeling of a Fish Caudal Fin during Steady Swimming

    Science.gov (United States)

    Liu, Geng; Geng, Biao; Zheng, Xudong; Xue, Qian; Dong, Haibo

    2017-11-01

    It's widely thought that the flexibilities of fish fins play critical roles in propulsive performance enhancement (such as thrust augment and efficiency improvement) in nature. In order to explore the formation mechanisms of the fish fin's flexible morphing and its hydrodynamic benefits as well, a high-fidelity flow-structure/membrane interaction modeling of the fish caudal fin is conducted in this work. Following the realistic configuration of the fish caudal fin, a thin membrane supported by a series of beams is constructed. The material properties of the membrane and the beams are reversely determined by the realistic fin morphing obtained from the high-speed videos and the high fidelity flow-structure interaction simulations. With the accurate material property, we investigate the interplay between structure, kinematics and fluid flow in caudal fin propulsion. Detailed analyses on the relationship between the flexural stiffness, fin morphing patterns, hydrodynamic forces and vortex dynamics are then conducted.

  20. FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

    International Nuclear Information System (INIS)

    Ikushima, Takeshi

    1997-05-01

    In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use's guide for FINCRUSH. (author)

  1. FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use`s guide for FINCRUSH. (author)

  2. A Novel Implementation of a Flexible Robotic Fin Actuated by Shape Memory Alloy

    Institute of Scientific and Technical Information of China (English)

    Qin Yan; Lei Wang; Bo Liu; Jie Yang; Shiwu Zhang

    2012-01-01

    In this paper,study of a novel flexible robotic-fin actuated by Shape Memory Alloy (SMA) is presented.The developed robotic fin is capable of implementing various 3-Dimensional (3D) motions,which plays an important role in robot propulsion and maneuverability.Firstly,the morphological and mechanics parameters of a real pectoral fin from a carp are investigated.Secondly,a detailed design of the flexible pectoral fin driven by SMA is presented according to the previous morphological and mechanics analyses.Thirdly,a simplified theoretical model on the SMA fin plate is derived.The thermodynamics of the SMA plate and the relationship between curvature and phase transformation are analyzed.Finally,several simulations and model experiments are conducted according to the previous analyses.The results of the experiments are useful for the control of the robotic fin.The experimental results reveal that the SMA actuated fin ray has a good actuating performance.

  3. Hydrodynamic function of dorsal fins in spiny dogfish and bamboo sharks during steady swimming.

    Science.gov (United States)

    Maia, Anabela; Lauder, George V; Wilga, Cheryl D

    2017-11-01

    A key feature of fish functional design is the presence of multiple fins that allow thrust vectoring and redirection of fluid momentum to contribute to both steady swimming and maneuvering. A number of previous studies have analyzed the function of dorsal fins in teleost fishes in this context, but the hydrodynamic function of dorsal fins in freely swimming sharks has not been analyzed, despite the potential for differential functional roles between the anterior and posterior dorsal fins. Previous anatomical research has suggested a primarily stabilizing role for shark dorsal fins. We evaluated the generality of this hypothesis by using time-resolved particle image velocimetry to record water flow patterns in the wake of both the anterior and posterior dorsal fins in two species of freely swimming sharks: bamboo sharks ( Chiloscyllium plagiosum ) and spiny dogfish ( Squalus acanthias ). Cross-correlation analysis of consecutive images was used to calculate stroke-averaged mean longitudinal and lateral velocity components, and vorticity. In spiny dogfish, we observed a velocity deficit in the wake of the first dorsal fin and flow acceleration behind the second dorsal fin, indicating that the first dorsal fin experiences net drag while the second dorsal fin can aid in propulsion. In contrast, the wake of both dorsal fins in bamboo sharks displayed increased net flow velocity in the majority of trials, reflecting a thrust contribution to steady swimming. In bamboo sharks, fluid flow in the wake of the second dorsal fin had higher absolute average velocity than that for first dorsal fin, and this may result from a positive vortex interaction between the first and second dorsal fins. These data suggest that the first dorsal fin in spiny dogfish has primarily a stabilizing function, while the second dorsal fin has a propulsive function. In bamboo sharks, both dorsal fins can contribute thrust and should be considered as propulsive adjuncts to the body during steady

  4. Performance and optimum design of convective-radiative rectangular fin with convective base heating, wall conduction resistance, and contact resistance between the wall and the fin base

    International Nuclear Information System (INIS)

    Aziz, Abdul; Beers-Green, Arlen B.

    2009-01-01

    This paper investigates the performance and optimum design of a longitudinal rectangular fin attached to a convectively heated wall of finite thickness. The exposed surfaces of the fin lose heat to the environmental sink by simultaneous convection and radiation. The tip of the fin is assumed to lose heat by convection and radiation to the same sink. The analysis and optimization of the fin is conducted numerically using the symbolic algebra package Maple. The temperature distribution, the heat transfer rates, and the fin efficiency data is presented illustrating how the thermal performance of the fin is affected by the convection-conduction number, the radiation-conduction number, the base convection Biot number, the convection and radiation Biot numbers at the tip, and the dimensionless sink temperature. Charts are presented showing the relationship between the optimum convection-conduction number and the optimum radiation-conduction number for different values of the base convection Biot number and dimensionless sink temperature and fixed values of the convection and radiation Biot numbers at the tip. Unlike the few other papers which have applied the Adomian's decomposition and the differential quadrature element method to this problem but give illustrative results for specific fin geometry and thermal variables, the present graphical data are generally applicable and can be used by fin designers without delving into the mathematical details of the computational techniques.

  5. Diagnóstico molecular para Leishmaniasis

    Directory of Open Access Journals (Sweden)

    Ysabel Montoya

    1997-01-01

    Full Text Available El potencial diagnóstico de epitopes inmunodominantes seleccionados fue ensayado satisfactoriamente a fin de obtener una prueba serodiagnóstica alternativa para la Leishmaniasis Tegumentaria Americana. Dos proteínas recombinantes prometedoras de L. (v. peruviana referidas como T-26-U2/T26-U4 fueron reconocidas por sueros individuales de pacientes con Leishmaniasis Tegumentaria Americana usando Western Blot. La sensibilidad de la prueba fue de 86% con sueros permanentes con Leishmaniasis peruana.

  6. Un modelo Macroeconométrico para la Economía Colombiana.

    Directory of Open Access Journals (Sweden)

    Javier Arturo Birchenall

    2010-05-01

    Full Text Available Este documento analiza un modelo macroeconométrico de corto plazo para la economía colombiana, con el fin de evaluar el impacto de procesos de ajuste y estabilización. Se basa en una estructura que reconoce no neutralidades por rigideces de precios y descompone la economía a través de oferta y demanda agregada. El modelo se estima por diversos métodos para el período comprendido entre 1977 y 1998 con una frecuencia trimestral, con el fin de realizar proyecciones para períodos de uno y dos años.

  7. Differential induction of four msx homeobox genes during fin development and regeneration in zebrafish.

    Science.gov (United States)

    Akimenko, M A; Johnson, S L; Westerfield, M; Ekker, M

    1995-02-01

    To study the genetic regulation of growth control and pattern formation during fin development and regeneration, we have analysed the expression of four homeobox genes, msxA, msxB, msxC and msxD in zebrafish fins. The median fin fold, which gives rise to the unpaired fins, expresses these four msx genes during development. Transcripts of the genes are also present in cells of the presumptive pectoral fin buds. The most distal cells, the apical ectodermal ridge of the paired fins and the cleft and flanking cells of the median fin fold express all these msx genes with the exception of msxC. Mesenchymal cells underlying the most distal cells express all four genes. Expression of the msx genes in the fin fold and fin buds is transient and, by 3 days after fertilization, msx expression in the median fin fold falls below levels detectable by in situ hybridization. Although the fins of adult zebrafish normally have levels of msx transcripts undetectable by in situ hybridization, expression of all four genes is strongly reinduced during regeneration of both paired and unpaired fins. Induction of msx gene expression in regenerating caudal fins occurs as early as 30 hours postamputation. As the blastema forms, the levels of expression increase and reach a maximum between the third and fifth days. Then, msx expression progressively declines and disappears by day 12 when the caudal fin has grown back to its normal size. In the regenerating fin, the blastema cells that develop at the tip of each fin ray express msxB and msxC. Cells of the overlying epithelium express msxA and msxD, but do not express msxB or msxC. Amputations at various levels along the proximodistal axis of the fin suggest that msxB expression depends upon the position of the blastema, with cells of the rapidly proliferating proximal blastema expressing higher levels than the cells of the less rapidly proliferating distal blastema. Expression of msxC and msxD is independent of the position of the blastema cell

  8. Finned Carbon-Carbon Heat Pipe with Potassium Working Fluid

    Science.gov (United States)

    Juhasz, Albert J.

    2010-01-01

    This elemental space radiator heat pipe is designed to operate in the 700 to 875 K temperature range. It consists of a C-C (carbon-carbon) shell made from poly-acrylonitride fibers that are woven in an angle interlock pattern and densified with pitch at high process temperature with integrally woven fins. The fins are 2.5 cm long and 1 mm thick, and provide an extended radiating surface at the colder condenser section of the heat pipe. The weave pattern features a continuous fiber bath from the inner tube surface to the outside edges of the fins to maximize the thermal conductance, and to thus minimize the temperature drop at the condenser end. The heat pipe and radiator element together are less than one-third the mass of conventional heat pipes of the same heat rejection surface area. To prevent the molten potassium working fluid from eroding the C C heat pipe wall, the shell is lined with a thin-walled, metallic tube liner (Nb-1 wt.% Zr), which is an integral part of a hermetic metal subassembly which is furnace-brazed to the inner surface of the C-C tube. The hermetic metal liner subassembly includes end caps and fill tubes fabricated from the same Nb-1Zr alloy. A combination of laser and electron beam methods is used to weld the end caps and fill tubes. A tungsten/inert gas weld seals the fill tubes after cleaning and charging the heat pipes with potassium. The external section of this liner, which was formed by a "Uniscan" rolling process, transitions to a larger wall thickness. This section, which protrudes beyond the C-C shell, constitutes the "evaporator" part of the heat pipe, while the section inside the shell constitutes the condenser of the heat pipe (see figure).

  9. Invertir para el futuro: el fortalecimiento de capacidades en Marruecos

    OpenAIRE

    André, Mathieu; Charlet, France

    2007-01-01

    En 2006, a petición de ACNUR, la ONG francesa Forum Réfugiés dirigió dos misiones para ayudar a reforzar la capacidad local en Marruecos con el fin de proporcionar asistencia letrada y asesoramiento a los solicitantes de asilo y los refugiados.

  10. Correlated evolution of body and fin morphology in the cichlid fishes.

    Science.gov (United States)

    Feilich, Kara L

    2016-10-01

    Body and fin shapes are chief determinants of swimming performance in fishes. Different configurations of body and fin shapes can suit different locomotor specializations. The success of any configuration is dependent upon the hydrodynamic interactions between body and fins. Despite the importance of body-fin interactions for swimming, there are few data indicating whether body and fin configurations evolve in concert, or whether these structures vary independently. The cichlid fishes are a diverse family whose well-studied phylogenetic relationships make them ideal for the study of macroevolution of ecomorphology. This study measured body, and caudal and median fin morphology from radiographs of 131 cichlid genera, using morphometrics and phylogenetic comparative methods to determine whether these traits exhibit correlated evolution. Partial least squares canonical analysis revealed that body, caudal fin, dorsal fin, and anal fin shapes all exhibited strong correlated evolution consistent with locomotor ecomorphology. Major patterns included the evolution of deep body profiles with long fins, suggestive of maneuvering specialization; and the evolution of narrow, elongate caudal peduncles with concave tails, a combination that characterizes economical cruisers. These results demonstrate that body shape evolution does not occur independently of other traits, but among a suite of other morphological changes that augment locomotor specialization. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  11. Effects of the partially movable control fin with end plate of underwater vehicle

    Directory of Open Access Journals (Sweden)

    Chul-Min Jung

    2017-01-01

    Full Text Available Underwater torpedo has control fin with very low aspect ratio due to launching from limited size of cylindrical torpedo tube. If the aspect ratio of control fin of underwater vehicle is very low three-dimensional flow around control fin largely reduces control forces. In this study, the end plate was applied to reduce the three-dimensional flow effects of partially movable control fin of underwater vehicle. Through numerical simulations the flow field around control fin was examined with and without end plate for different flap angles. The pressure, vorticity, lift and torque on the control fin were analyzed and compared to experiments. The comparison have shown a reasonable agreement between numerical and experimental results and the effect of end plate on a low aspect ratio control fin. When the end plate was attached to the movable control fin, the lift increased and the actuator shaft torque did not significantly change. As this means less consumption of the actuator shaft torque compared to the control fin that has the same control force, the inner actuator capacity can be reduced and energy consumption can be saved. Considering this, it is expected to be effectively applied to the control fin design of underwater vehicles such as torpedoes.

  12. Highly flexible SRAM cells based on novel tri-independent-gate FinFET

    Science.gov (United States)

    Liu, Chengsheng; Zheng, Fanglin; Sun, Yabin; Li, Xiaojin; Shi, Yanling

    2017-10-01

    In this paper, a novel tri-independent-gate (TIG) FinFET is proposed for highly flexible SRAM cells design. To mitigate the read-write conflict, two kinds of SRAM cells based on TIG FinFETs are designed, and high tradeoff are obtained between read stability and speed. Both cells can offer multi read operations for frequency requirement with single voltage supply. In the first TIG FinFET SRAM cell, the strength of single-fin access transistor (TIG FinFET) can be flexibly adjusted by selecting five different modes to meet the needs of dynamic frequency design. Compared to the previous double-independent-gate (DIG) FinFET SRAM cell, 12.16% shorter read delay can be achieved with only 1.62% read stability decrement. As for the second TIG FinFET SRAM cell, pass-gate feedback technology is applied and double-fin TIG FinFETs are used as access transistors to solve the severe write-ability degradation. Three modes exist to flexibly adjust read speed and stability, and 68.2% larger write margin and 51.7% shorter write delay are achieved at only the expense of 26.2% increase in leakage power, with the same layout area as conventional FinFET SRAM cell.

  13. Fish Pectoral Fin Hydrodynamics; Part III: Low Dimensional Models via POD Analysis

    Science.gov (United States)

    Bozkurttas, M.; Madden, P.

    2005-11-01

    The highly complex kinematics of the pectoral fin and the resulting hydrodynamics does not lend itself easily to analysis based on simple notions of pitching/heaving/paddling kinematics or lift/drag based propulsive mechanisms. A more inventive approach is needed to dissect the fin gait and gain insight into the hydrodynamic performance of the pectoral fin. The focus of the current work is on the hydrodynamics of the pectoral fin of a bluegill sunfish in steady forward motion. The 3D, time-dependent fin kinematics is obtained via a stereo-videographic technique. We employ proper orthogonal decomposition to extract the essential features of the fin gait and then use CFD to examine the hydrodynamics of simplified gaits synthesized from the POD modes. The POD spectrum shows that the first two, three and five POD modes capture 55%, 67%, and 80% of the motion respectively. The first three modes are in particular highly distinct: Mode-1 is a ``cupping'' motion where the fin cups forward as it is abducted; Mode-2 is an ``expansion'' motion where the fin expands to present a larger area during adduction and finally Mode-3 involves a ``spanwise flick'' of the dorsal edge of the fin. Numerical simulation of flow past fin gaits synthesized from these modes lead to insights into the mechanisms of thrust production; these are discussed in detail.

  14. Guía para la evaluación del riesgo de los polinizadores

    Science.gov (United States)

    La Guía para la evaluación del riesgo de los polinizadores de la EPA es parte de una estrategia de la evaluación de los riesgos que presentan los pesticidas para las abejas a fin de mejorar la protección de los polinizadores.

  15. Transfer coefficients for plate fin and elliptical tube heat exchangers

    International Nuclear Information System (INIS)

    Saboya, S.M.; Saboya, F.E.M.

    1981-01-01

    In order to determine transfer coefficients for plate fin and elliptical tube exchangers, mass transfer experiments have been performed using the naphthalene sublimation technique. By means of the heat-mass transfer analogy, the results can be converted to heat transfer results. The transfer coefficients were compared with those for circular tube exchangers and the comparison revealed no major differences. This is a positive outcome, since the use of elliptical tubes may reduce substantially the pressure drop, without affecting the transfer characteristics.(Author) [pt

  16. Investigations into the dynamic behaviour of finned tube heat exchangers

    International Nuclear Information System (INIS)

    Sandbrink, J.; Stegemann, D.

    1981-01-01

    Atmospheric disturbances due to thunder storms, side wind effects on the shell or ground inversion can impair the heat dissipation of a cooling tower. These effects react on the overall power plant, which is reflected in the varied electrical output. This uncontrolled behaviour has been investigated in detail for the case of a boiling water reactor nuclear power station with indirect natural draught dry cooling and compared with controlled performance. A computer model, which has been checked out by means of experimental investigations on three different types of tube, is presented to describe the dynamic behaviour of finned tube heat exchangers. (orig.) [de

  17. Iterative solution of fluid flow in finned tubes

    International Nuclear Information System (INIS)

    Syed, S.K.; Tuphome, E.G.; Wood, S.A.

    2004-01-01

    A difference-based numerical algorithm is developed to efficiently solve a class of elliptic boundary value problems up to any desired order of accuracy. Through multi-level discretization the algorithm uses the multigrid concept of nested iterations to accelerate the convergence rate at higher discretization levels and exploits the advantages of extrapolation methods to achieve higher order accuracy with less computational work. The algorithm employs the SOR method to solve the discrete problem at each discretization level by using an estimated optimum value of the relaxation parameter. The advantages of the algorithm are shown through comparison with the simple discrete method for simulations of fluid flows in finned circular ducts. (author)

  18. Application of homotopy analysis method and inverse solution of a rectangular wet fin

    International Nuclear Information System (INIS)

    Panda, Srikumar; Bhowmik, Arka; Das, Ranjan; Repaka, Ramjee; Martha, Subash C.

    2014-01-01

    Highlights: • Solution of a wet fin with is obtained by homotopy analysis method (HAM). • Present HAM results have been well-validated with literature results. • Inverse analysis is done using genetic algorithm. • Measurement error of ±10–12% (approx.) is found to yield satisfactory reconstructions. - Abstract: This paper presents the analytical solution of a rectangular fin under the simultaneous heat and mass transfer across the fin surface and the fin tip, and estimates the unknown thermal and geometrical configurations of the fin using inverse heat transfer analysis. The local temperature field is obtained by using homotopy analysis method for insulated and convective fin tip boundary conditions. Using genetic algorithm, the thermal and geometrical parameters, viz., thermal conductivity of the material, surface heat transfer coefficient and dimensions of the fin have been simultaneously estimated for the prescribed temperature field. Earlier inverse studies on wet fin have been restricted to the analysis of nonlinear governing equation with either insulated tip condition or finite tip temperature only. The present study developed a closed-form solution with the consideration of nonlinearity effects in both governing equation and boundary condition. The study on inverse optimization leads to many feasible combination of fin materials, thermal conditions and fin dimensions. Thus allows the flexibility for designing a fin under wet conditions, based on multiple combinations of fin materials, fin dimensions and thermal configurations to achieve the required heat transfer duty. It is further determined that the allowable measurement error should be limited to ±10–12% in order to achieve satisfactory reconstruction

  19. Heat transfer enhancement of phase change materials by fins under simultaneous charging and discharging

    International Nuclear Information System (INIS)

    Joybari, Mahmood Mastani; Haghighat, Fariborz; Seddegh, Saeid; Al-Abidi, Abduljalil A.

    2017-01-01

    Highlights: • CFD simulation of a finned triplex tube heat exchanger with PCM under simultaneous charging and discharging. • Developed fin configurations for SCD, compatible with natural convection. • More fins enhanced the heat transfer as long as natural convection was not suppressed. • Longer fins enhanced the heat transfer as long as natural convection was not suppressed. • The effect of fin thickness was negligible, similar to non-SCD conditions. - Abstract: Due to the inherent intermittency of renewable energy sources such as solar, latent heat thermal energy storage in phase change materials (PCMs) has received considerable attention. Among several techniques to enhance PCMs’ thermal conductivity, the majority of studies have focused on fin integration due to its simplicity, ease of manufacturing, and low cost. In this study, utilization of extended surfaces (by longitudinal fins) was investigated by development of a numerical model to study the performance of a triplex tube heat exchanger (TTHX) equipped with a PCM under simultaneous charging and discharging (SCD). Governing equations were developed and numerically solved using ANSYS Fluent v16.2. Three conventional fin geometries and six developed fin configurations were compared based on the temperature, liquid fraction, and natural convection behavior under both SCD and non-SCD conditions. The intensity of natural convection was investigated for different fins for the inside heating/outside cooling scenario based on the solid–liquid interface evolution over time. The results indicated that since the buoyancy forces induce upward melted PCM motion, the inner hot tube requires fins on its lower half, while the outer cold one should be extended from its upper half. It was concluded that the case with 3 hot tube fins and 1 cold tube fin is most compatible with natural convection and provides the best performance under SCD conditions.

  20. Regulation of use of radiation for quarantine purposes; Regulamentacao do uso da radiacao para fins quarentenarios

    Energy Technology Data Exchange (ETDEWEB)

    Itepan, Natanael Marcio, E-mail: natanael.itepan@unianhanguera.edu.b [Faculdade Anhanguera, Piracicaba, SP (Brazil); Costa, Neivaldo; Furlan, Gilberto Ribeiro; Walder, Julio Marcos Melges, E-mail: neivaldo@cena.usp.b, E-mail: gilfurlan@cena.usp.b, E-mail: jmwalder@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2011-07-01

    The main aspects of Instruction No. 9 are: a) the nuclear plant that use ionizing radiation as a phyto sanitary treatment for quarantine purposes, must be accredited by the agency of the Agriculture, Livestock and Supply Ministry (MAPA) and the licensing by the Nuclear Energy National Commission (CNEN) and other regulatory bodies, b) control of the applied dose will follow a standard operating procedure should be performed by independent organization, authorized by the Brazilian ONPF (Phyto sanitary Protection National Organization), c) the unit of radiation treatment should ensure traceability and must maintain records of phyto sanitary treatments, d) there should be bilateral work plan between the ONPF of Brazil and other countries for the established radiation treatment protocol. The ONPF of Brazil is the Sanitary Vegetarian Department. Ionizing radiation (cold pasteurization) is shown in an alternative technology to phyto sanitary control for quarantine purposes. (author)

  1. Familia - Escuela - Comunidad: pilares para la inclusión

    Directory of Open Access Journals (Sweden)

    Rafael Bell Rodríguez

    2010-01-01

    Full Text Available En el artículo se aborda, desde la perspectiva del enfoque histórico-cultural, la necesidad del establecimiento de una sólida relación familia-escuela-comunidad a fin de asegurar su decisiva contribución para el logro del real acceso de las personas con alguna discapacidad a la cultura, que se reconoce como la más prometedora vía para su desarrollo humano.

  2. Some exact solutions of nonlinear fin problem for steady heat transfer in longitudinal fin with different profiles

    CSIR Research Space (South Africa)

    Mhlongo, MD

    2014-05-01

    Full Text Available and heat transfer coefficient.This work has been extended in [11] whereby the introduction of the Kirchhoff transformation linearized the one-dimensional fin problem when heat transfer is a differential consequence of thermal conductivity. Symmetry methods... 𝑥 ( 𝜉 ) , 𝜁 𝑥𝑥 = 𝐷 𝑥 (𝜁 𝑥 ) − 𝜃 󸀠󸀠 𝐷 𝑥 ( 𝜉 ) , (46) 10 Advances in Mathematical Physics Table 10: Lie bracket of the admitted symmetry algebra for𝑚 ̸= 𝑛, 𝑛 ̸= − 1 and various 𝑓(𝑥). 𝑓(𝑥) = 𝑥 𝑎 𝑎 = 0 𝑛 arbitrary 𝑓(𝑥) = 𝑥𝑎...

  3. FinFET and UTBB for RF SOI communication systems

    Science.gov (United States)

    Raskin, Jean-Pierre

    2016-11-01

    Performance of RF integrated circuit (IC) is directly linked to the analog and high frequency characteristics of the transistors, the quality of the back-end of line process as well as the electromagnetic properties of the substrate. Thanks to the introduction of the trap-rich high-resistivity Silicon-on-Insulator (SOI) substrate on the market, the ICs requirements in term of linearity are fulfilled. Today partially depleted SOI MOSFET is the mainstream technology for RF SOI systems. Future generations of mobile communication systems will require transistors with better high frequency performance at lower power consumption. The advanced MOS transistors in competition are FinFET and Ultra Thin Body and Buried oxide (UTBB) SOI MOSFETs. Both devices have been intensively studied these last years. Most of the reported data concern their digital performance. In this paper, their analog/RF behavior is described and compared. Both show similar characteristics in terms of transconductance, Early voltage, voltage gain, self-heating issue but UTBB outperforms FinFET in terms of cutoff frequencies thanks to their relatively lower fringing parasitic capacitances.

  4. Experimental investigation of water sprayed finned heat exchanger tube bundles

    International Nuclear Information System (INIS)

    Sommer, A.

    1987-07-01

    Experimental investigations have been made to study the performance of two finned tube-bundle heat exchangers (FORGO type) when wetted by water sprays. The heat exchangers are designed to cool water in a dry cooling tower. The test-elements had a frontal area of 1 m 2 . The water sprays were created by 20 nozzles, 200 mm in front of the heat exchangers. Air velocities at the inlet of the coolers were in the range 0,8 m/s to 12 m/s and initial temperature differences ITD reached 45 degrees C. The test facility was designed to determine the combined latent and sensible heat fluxes in the wetted heat exchanger, the airside pressure drop and the air humidity and temperature at the exchanger inlet and outlet, and to measure the weight of the water wetting the cooler's surface. The sprayed test elements were investigated in different positions, but most of the experiments were carried out in the position with the fins horizontal

  5. Fast breeder cladding tubes provided with helical fins

    International Nuclear Information System (INIS)

    Baumgaertner, E.; Hoffmann, H.; Miller, H.; Jacobi, O.; Bojarski, E.; Freund, D.; Reiser, H.

    1977-04-01

    Development of fast breeder tubes with helical fins started around 1966. The development was initiated mainly by the search for a more favorable alternative to the conventional spacers such as grids and spiral wires. First of all the possibility was investigated of fabricating them on an industrial scale. The first thermohydraulic and fluiddynamic tests were made in parallel by AEG, GfK and Interatom. Besides the possibility of industrial fabrication the problems of non-destructive testing for geometry and material defects had to be treated with priority. In this report the different stages of development are shown and, finally, two rather large projects are described. These projects are the study ready for the licensing procedure concerning the irradiation of finned tube oxide fuel elements in KNK II and the already completed 19-rod fuel element bundle irradiation experiment Mol 7D of GfK performed in the 500 kW sodium loop of the Belgian BR2 reactor. In this BR2 experiment the maximum target burnup of 85,000 MWd/t of oxide was attained without trouble. (orig.) [de

  6. Vitrification of caudal fin explants from zebrafish adult specimens.

    Science.gov (United States)

    Cardona-Costa, J; Roig, J; Perez-Camps, M; García-Ximénez, F

    2006-01-01

    No data on vitrification of tissue samples are available in fishes. Three vitrification solutions were compared: V1: 20% ethylene glycol and 20% dimethyl sulphoxide; V2: 25% propylene glycol and 20% dimethyl sulphoxide, and; V3: 20% propylene glycol and 13% methanol, all three prepared in Hanks' buffered salt solution plus 20 percent FBS, following the same one step vitrification procedure developed in mammals. Caudal fin tissue pieces were vitrified into 0.25 ml plastic straws in 30s and stored in liquid nitrogen for 3 days minimum, warmed (10s in nitrogen vapour and 5s in a 25 degree C water bath) and cultured (L-15 plus 20% FBS at 28.5 degree C). At the third day of culture, both attachment and outgrowing rates were recorded. V3 led to the worst results (8% of attachment rate). V1 and V2 allow higher attachment rates (V1: 63% vs V2: 50%. P < 0.05) but not significantly different outgrowing rates (83% to 94%). Vitrification of caudal fin pieces is advantageous in fish biodiversity conservation, particularly in the wild, due to the simplicity of procedure and equipment.

  7. Patella dislocation with vertical axis rotation: the "dorsal fin" patella.

    Science.gov (United States)

    Gamble, David; Otto, Quentin; Carrothers, Andrew D; Khanduja, Vikas

    2015-01-01

    A 44-year-old woman presented following minor trauma to her right knee. While dancing she externally rotated around a planted foot and felt sudden pain in her right knee. She presented with her knee locked in extension with a "dorsal fin" appearance of the soft tissues tented over the patella. This was diagnosed as a rare case of an intraarticular patella dislocation, which was rotated 90 degrees about the vertical axis. Closed reduction in the emergency room was unsuccessful but was achieved in theatre under general anaesthetic with muscle relaxation. Postreduction arthroscopy demonstrated that no osteochondral or soft tissue damage to the knee had been sustained. In patients presenting with a knee locked in extension with tenting of skin over the patella (the "dorsal fin" appearance), intra-articular patella dislocation should be suspected. Attempts to reduce vertical patella dislocations under sedation with excessive force or repeatedly without success should be avoided to prevent unnecessary damage to the patellofemoral joint. In this clinical situation we recommend closed reduction under general anaesthetic followed by immediate knee arthroscopy under the same anaesthetic to ensure that there is no chondral damage to the patella or femoral trochlea and to rule out an osteochondral fracture.

  8. Lionfish predators use flared fin displays to initiate cooperative hunting.

    Science.gov (United States)

    Lönnstedt, Oona M; Ferrari, Maud C O; Chivers, Douglas P

    2014-06-01

    Despite considerable study, mystery surrounds the use of signals that initiate cooperative hunting in animals. Using a labyrinth test chamber, we examined whether a lionfish, Dendrochirus zebra, would initiate cooperative hunts with piscine partners. We found that D. zebra uses a stereotyped flared fin display to alert conspecific and heterospecific lionfish species Pterois antennata to the presence of prey. Per capita success rate was significantly higher for cooperative hunters when compared with solitary ones, with hunt responders assisting hunt initiators in cornering the prey using their large extended pectoral fins. The initiators would most often take the first strike at the group of prey, but both hunters would then alternate striking at the remaining prey. Results suggest that the cooperative communication signal may be characteristic to the lionfish family, as interspecific hunters were equally coordinated and successful as intraspecific hunters. Our findings emphasize the complexity of collaborative foraging behaviours in lionfish; the turn-taking in strikes suggests that individuals do not solely try to maximize their own hunting success: instead they equally share the resources between themselves. Communicative group hunting has enabled Pteroine fish to function as highly efficient predators. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  9. Forced convection heat transfer correlation for finned plates in a duct

    International Nuclear Information System (INIS)

    Chae, Myeong-Seon; Moon, Je-Young; Chung, Bum-Jin

    2014-01-01

    Forced convection heat transfer experiments were conducted for plate-fin in a duct using various fin spacing, fin height, duct width, Reynolds number for Prandtl numbers 2,014. Based upon analogy concept, mass transfer rate were measured instead of heat transfer rates. The heat transfer rates were enhanced with the increase of fin height and decrease of fin spacing as they increase the heat transfer area. Meanwhile, heat transfer rates were impaired with the increase of the duct width as the bypass flows increased to tip clearance region. Forced convection heat transfer correlations were developed for laminar and turbulent flow conditions and for narrow and wide ducts. The work draws attention to the tip clearance on the heat transfer of the finned plate in a duct. (author)

  10. Mechanism of tonal noise generation from circular cylinder with spiral fin

    Science.gov (United States)

    Yamashita, Ryo; Hayashi, Hidechito; Okumura, Tetsuya; Hamakawa, Hiromitsu

    2014-12-01

    The pitch of the spiral finned tube influences seriously to the acoustic resonance in the heat exchanger. In this research, the flow characteristics in relating to the aeolian tone from the finned cylinder are studied by the numerical simulation. It is observed that the tonal noise generated from the finned tube at two pitch spaces. The ratio of the fin pitch to the cylinder diameter is changed at 0.11 and 0.27. The tone level increases and the frequency decreases with the pitch shorter. The separation flow from the cylinder generates the span-wise vortices, Karman vortices, and the separation flow from the fin generates the stream-wise vortices. When the fin pitch ratio is small, the stream-wise vortices line up to span-wise and become weak rapidly. Only the Karman vortices are remained and integrate in span. So the Karman vortex became large. This causes the low frequency and the large aeolian tone.

  11. Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2013-10-01

    Full Text Available The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

  12. Fgf16 is essential for pectoral fin bud formation in zebrafish

    International Nuclear Information System (INIS)

    Nomura, Ryohei; Kamei, Eriko; Hotta, Yuuhei; Konishi, Morichika; Miyake, Ayumi; Itoh, Nobuyuki

    2006-01-01

    Zebrafish pectoral fin bud formation is an excellent model for studying morphogenesis. Fibroblast growth factors (Fgfs) and sonic hedgehog (shh) are essential for pectoral fin bud formation. We found that Fgf16 was expressed in the apical ectodermal ridge (AER) of fin buds. A knockdown of Fgf16 function resulted in no fin bud outgrowth. Fgf16 is required for cell proliferation and differentiation in the mesenchyme and the AER of the fin buds, respectively. Fgf16 functions downstream of Fgf10, a mesenchymal factor, signaling to induce the expression of Fgf4 and Fgf8 in the AER. Fgf16 in the AER and shh in the zone of polarizing activity (ZPA) interact to induce and/or maintain each other's expression. These findings have revealed that Fgf16, a newly identified AER factor, plays a crucial role in pectoral fin bud outgrowth by mediating the interactions of AER-mesenchyme and AER-ZPA

  13. Characteristics of a micro-fin evaporator: Theoretical analysis and experimental verification

    OpenAIRE

    Zheng Hui-Fan; Fan Xiao-Wei; Wang Fang; Liang Yao-Hua

    2013-01-01

    A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good a...

  14. Plate-fin array cooling using a finger-like piezoelectric fan

    International Nuclear Information System (INIS)

    Shyu, Jin-Cherng; Syu, Jhih-Zong

    2014-01-01

    In this study, the heat transfer of a plate-fin array cooled by a vibrating finger-like piezoelectric fan comprising four flexible rectangular blades was investigated. The results indicated that the heat transfer enhancement of the fin array cooled by a vibrating piezoelectric fan at x/L = 0.5 and H = 5 mm ranged between 1.5 and 3.3, regardless of the fin array orientation. However, the heat transfer enhancement caused by a fan being placed at either edge of the fin array yielded a dissimilar result between both of the fin array orientations because of the superimposed effects of the boundary layer development and the air flow induced by the fan. This dissimilarity was especially noticeable when the piezoelectric fan was composed of aluminum blades to accommodate the moderate Reynolds number. In addition to the Reynolds number, the ratio of the fan blade vibration envelope to the source area determined the Nu number of the piezoelectric fan-cooled fin array. This design enhanced the fin array heat transfer and reduced cooler volume by embedding multiple vibrating beams into the fin array. -- Highlights: • Heat transfer of a piezoelectric fan-cooled plate-fin array was investigated. • Effects of fan position, fan height and fan material on heat transfer were examined. • Similar heat transfer enhancement range was shown for both fin array orientations. • Fin heat transfer with a running Al fan at x = 0 was higher than that at x = 0.25L. • Besides fan Reynolds number, the area ratio also determined Nu of the fin array

  15. Simulation study of a 3-D device integrating FinFET and UTBFET

    KAUST Repository

    Fahad, Hossain M.

    2015-01-01

    By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate FinFETs with unprecedented levels of chip-area efficiency. This makes it suitable for ultralarge-scale integration high-performance logic at and beyond the 10-nm technology node.

  16. Integrated Rudder/Fin Concise Control Based on Frequency Domain Analysis

    OpenAIRE

    W. Guan; Z. J. Su; G. Q. Zhang

    2013-01-01

    This paper describes a concise robust controller design of integrated rudder and fin control system in use of the closed loop gain shaping algorithm (CGSA) strategy. Compared with the arbitrary selection of weighting function in integrated rudder and fin H∞ mixed sensitivity control design procedures, the CGSA methods provided a relatively more straightforward and concise design method. Simulations were described that the overall performance of each CGSA rudder and fin control loop and the in...

  17. Thermal performance of a porus radial fin with natural convection and radiative heat losses

    Directory of Open Access Journals (Sweden)

    Darvishi M.T.

    2015-01-01

    Full Text Available An analytic (series solution is developed to describe the thermal performance of a porous radial fin with natural convection in the fluid saturating the fin and radiation heat loss from the top and bottom surfaces of the fin. The HAM results for the temperature distribution and base heat flux are compared with the direct numerical results and found to be very accurate.

  18. Enhancement of heat transfer. The performance of micro-fin tubes

    International Nuclear Information System (INIS)

    Muzzio, A.

    2001-01-01

    Micro-fin tubes are characterised by numerous, very small integral fins that spiral down the inner surface. A very interesting feature of their performance in flow boiling and condensation is a large heat transfer enhancement accompanied by a low pressure drop penalty. This paper presents a general overview of micro-fin tubes and of their performance in evaporation, condensation and single-phase flow [it

  19. The FinTech phenomenon: antecedents of financial innovation perceived by the popular press

    OpenAIRE

    Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

    2016-01-01

    The financial industry has been strongly influenced by digitalization in the past few years reflected by the emergence of 'FinTech,' which represents the marriage of 'finance' and 'information technology.' FinTech provides opportunities for the creation of new services and business models and poses challenges to traditional financial service providers. Therefore, FinTech has become a subject of debate among practitioners, investors, and researchers and is highly visible in the popular media. ...

  20. Computational thermal analysis of cylindrical fin design parameters and a new methodology for defining fin structure in LED automobile headlamp cooling applications

    International Nuclear Information System (INIS)

    Sökmen, Kemal Furkan; Yürüklü, Emrah; Yamankaradeniz, Nurettin

    2016-01-01

    Highlights: • In the study, cooling of LED headlamps in automotive is investigated. • The study is based on free convection cooling of LED module. • Besides free convection, Monte Carlo model is used as radiation model as well. • A new algorithm is presented for designing optimum fin structure. • Suggested algorithm for optimum design is verified by various simulations. - Abstract: In this study, the effects of fin design, fin material, and free and forced convection on junction temperature in automotive headlamp cooling applications of LED lights are researched by using ANSYS CFX 14 software. Furthermore a new methodology is presented for defining the optimum cylindrical fin structure within the given limits. For measuring the performance of methodology, analyses are carried out for various ambient temperatures (25 °C, 50 °C and 80 °C) and different LED power dissipations (0.5 W, 0.75 W, 1 W and 1.25 W). Then, analyses are repeated at different heat transfer coefficients and different fin materials in order to calculate LED junction temperature in order to see if the fin structure proposed by the methodology is appropriate for staying below the given safety temperature limit. As a result, the suggested method has always proposed proper fin structures with optimum characteristics for given LED designs. As another result, for safe junction temperature ranges, it is seen that for all LED power dissipations, adding aluminum or copper plate behind the printed circuit board at low ambient temperatures is sufficient. Also, as the ambient temperature increases, especially in high powered LED lights, addition of aluminum is not sufficient and fin usage becomes essential. High heat transfer coefficient and using copper fin affect the junction temperature positively.

  1. An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

    International Nuclear Information System (INIS)

    Aris, M.S.; McGlen, R.; Owen, I.; Sutcliffe, C.J.

    2011-01-01

    Forced air convection heat pipe cooling systems play an essential role in the thermal management of electronic and power electronic devices such as microprocessors and IGBT's (Integrated Gate Bipolar Transistors). With increasing heat dissipation from these devices, novel methods of improving the thermal performance of fin stacks attached to the heat pipe condenser section are required. The current work investigates the use of a wing type surface protrusions in the form of 3-D delta wing tabs adhered to the fin surface, thin wings punched-out of the fin material and TiNi shape memory alloy delta wings which changed their angles of attack based on the fin surface temperature. The longitudinal vortices generated from the wing designs induce secondary mixing of the cooler free stream air entering the fin stack with the warmer fluid close to the fin surfaces. The change in angle of the attack of the active delta wings provide heat transfer enhancement while managing flow pressure losses across the fin stack. A heat transfer enhancement of 37% compared to a plain fin stack was obtained from the 3-D tabs in a staggered arrangement. The punched-out delta wings in the staggered and inline arrangements provided enhancements of 30% and 26% respectively. Enhancements from the active delta wings were lower at 16%. However, as these devices reduce the pressure drop through the fin stack by approximately 19% in the de-activate position, over the activated position, a reduction in fan operating cost may be achieved for systems operating with inlet air temperatures below the maximum inlet temperature specification for the device. CFD analysis was also carried out to provide additional detail of the local heat transfer enhancement effects. The CFD results corresponded well with previously published reports and were consistent with the experimental findings. - Highlights: → Heat transfer enhancements of heat pipe fin stacks was successfully achieved using fixed and active delta

  2. Burnout in the boiling of water and freon-113 on tubes with annular fins

    International Nuclear Information System (INIS)

    Rubin, I.R.; Pul'kin, I.N.; Roizen, L.I.

    1986-01-01

    This paper presents the results of numerical calculations of burnout heat flux associated with the boiling of Freon-113 and water on an annular fin of constant thickness which have been approximated by simple analytical relations. These are used to calculate the critical burnout parameters of tubes with an annular fin assembly. The calculated data may be used for the analysis of tubes with an annular fin assembly over a wide range of variation of the thermophysical properties of the material and geometrical parameters of the fin assembly

  3. Investigation of thermal effects on FinFETs in the quasi-ballistic regime

    Science.gov (United States)

    Yin, Longxiang; Shen, Lei; Di, Shaoyan; Du, Gang; Liu, Xiaoyan

    2018-04-01

    In this work, the thermal effects of FinFETs in the quasi-ballistic regime are investigated using the Monte Carlo method. Bulk Si nFinFETs with the same fin structure and two different gate lengths L g = 20 and 80 nm are investigated and compared to evaluate the thermal effects on the performance of FinFETs in the quasi-ballistic regime. The on current of the 20 nm FinFET with V gs = 0.7 V does not decrease with increasing lattice temperature (T L) at a high V ds. The electrostatic properties in the 20 nm FinFET are more affected by T L than those in the 80 nm FinFET. However, the electron transport in the 20 nm FinFET is less affected by T L than that in the 80 nm FinFET. The electrostatic properties being more sensitive and the electron transport being less sensitive to thermal effects in the quasi-ballistic regime than in the diffusive regime should be considered for effective device modeling and design.

  4. Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei, E-mail: chenfei@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Zhang, Lishen, E-mail: lishenzhang@sina.com [Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Huai, Xiulan, E-mail: hxl@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Jufeng, E-mail: lijufeng.net@163.com [Nuclear and Radiation Safety Center, Ministry of Environmental Protection, Beijing 100082 (China); Zhang, Hang, E-mail: zhanghang@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhigang, E-mail: zgliu9322@163.com [Energy Research Institute of Shandong Academy of Sciences, Jinan, Shandong 250014 (China)

    2017-04-15

    Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

  5. Comparative study on thermal performance of natural draft cooling towers with finned shells

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, Mohsen [Bu-Ali Sina Univ., Hamedan (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2016-10-15

    The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

  6. Comparative study on thermal performance of natural draft cooling towers with finned shells

    International Nuclear Information System (INIS)

    Goodarzi, Mohsen

    2016-01-01

    The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

  7. DETERMINATION OF TEMPERATURE DISTRIBUTION FOR ANNULAR FINS WITH TEMPERATURE DEPENDENT THERMAL CONDUCTIVITY BY HPM

    Directory of Open Access Journals (Sweden)

    Davood Domairry Ganji

    2011-01-01

    Full Text Available In this paper, homotopy perturbation method has been used to evaluate the temperature distribution of annular fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the fin. This method is useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. The homotopy perturbation method provides an approximate analytical solution in the form of an infinite power series. The annular fin heat transfer rate with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity.

  8. Heat transfer, erosion and acid condensation characteristics for novel H-type finned oval tube

    International Nuclear Information System (INIS)

    Wang, Y; Zhao, X; Tang, G

    2015-01-01

    Low efficiency of heat transfer, acid corrosion and erosion of economizers affect the economy and security in coal-fired power plants significantly. The H-type finned oval tube is proposed to alleviate these problems. Based on the H-type finned oval tube, we investigated three novel types of fins, including bleeding dimples, longitudinal vortex generators (LVGs), and compound dimple-LVG. We considered the three aspects together, and obtained the heat transfer, acid condensation rate and erosion loss. The results show that the tube bank with the new structured fins can improve the performance on the three aspects, and the compound dimple-LVG performs the highest comprehensive effect. (paper)

  9. Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

    International Nuclear Information System (INIS)

    Chen, Fei; Zhang, Lishen; Huai, Xiulan; Li, Jufeng; Zhang, Hang; Liu, Zhigang

    2017-01-01

    Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO_2) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

  10. Comprehensive study of flow and heat transfer at the surface of circular cooling fin

    Science.gov (United States)

    Mityakov, V. Yu; Grekov, M. A.; Gusakov, A. A.; Sapozhnikov, S. Z.; Seroshtanov, V. V.; Bashkatov, A. V.; Dymkin, A. N.; Pavlov, A. V.; Milto, O. A.; Kalmykov, K. S.

    2017-11-01

    For the first time is proposed to combine heat flux measurements with thermal imaging and PIV (particle image velocimetry) for a comprehensive study of flow and heat transfer at the surface of the circular cooling fin. The investigated hollow fin is heated from within with saturated water steam; meanwhile the isothermal external surface simulates one of the perfect fin. Flow and heat transfer at the surface of the solid fin of the same size and shape, made of titanium alloy is investigated in the same regimes. Gradient Heat Flux Sensors (GHFS) were installed at different places of the fin surface. Velocity field around a cylinder, temperature field at the surface of the fin and heat flux for each rated time were obtained. Comprehensive method including heat flux measurement, PIV and thermal imaging allow to study flow and heat transfer at the surface of the fin in real time regime. The possibility to study flow and heat transfer for non-isothermal fins is shown; it is allow to improve traditional calculation of the cooling fins.

  11. El objeto a en los sueños de fin de análisis

    Directory of Open Access Journals (Sweden)

    Celeste Labaronnie

    Full Text Available Resumen Este artículo se ubica en el marco del psicoanálisis lacaniano y su objetivo es la discusión de aportes teóricos sobre la plasmación del objeto a en los sueños de fin de análisis y su relación con el despertar. Se utilizan herramientas conceptuales de la disciplina para analizar cuatro contribuciones teóricas: la propuesta de Colette Soler de considerar la aparición del objeto a en algunos sueños como el punto de inserción de la pulsión, que conduce al despertar; los desarrollos de Ricardo Nepomiachi acerca de la plasmación onírica del vaciamiento del objeto a; la relación entre el objeto y el despertar sin angustia destacado por Frida Nemirovsky y Fabián Naparstek; y la noción de sueños-índice, postulada por Marcelo Mazzuca, en los cuales el objeto se inserta en una trama onírica, según una relación establecida entre deseo y satisfacción en determinado momento del análisis.

  12. Espacios del arte y el acecho de un fin: transitividad, porosidad y desaparición

    Directory of Open Access Journals (Sweden)

    Rosa María Droguett Abarca

    2014-12-01

    Full Text Available Ante la interrogante sobre el agotamiento o fin del arte en la posmodernidad, y el creciente dinamismo y porosidad de sus espacios, se propone la idea de fenómenos "en tránsito", donde la finitud sería reflejo de una crisis, pero también, el input para un nuevo estatuto estético y museológico. El fundamento estaría en la existencia de un tipo de arte y una estética de naturaleza topológica caracterizados por el desplazamiento, tal como lo propone Nicolas Bourriaud, y el museo como catástrofe o ruina planteado por Víctor Stoichita y Jean-Louis Déotte. Estos marcos especulativos se pondrán en tensión con dos proyectos que plantean un vaivén entre lo material y lo inmaterial que es mediado por el lenguaje, así como la literal errancia de los proyectos.

  13. Objetivos de organizações culturais sem fins lucrativos e suas fontes financiadoras

    Directory of Open Access Journals (Sweden)

    Samara Regina Bernardino Hoffmann

    Full Text Available A fim de compreender as mudanças no contexto das organizações culturais, apresenta-se uma reflexão sobre as transformações nos objetivos de dois grupos teatrais sem fins lucrativos de Florianópolis-SC e sobre a influência que os critérios requeridos pelas fontes financiadoras podem ter exercido neste processo. Quatro importantes categorias de análise guiaram a pesquisa: grupo teatral, objetivos, fontes de financiamento e critérios de avaliação de desempenho, orientando as entrevistas semi-estruturadas realizadas com os responsáveis pelas respectivas organizações e a observação constante das pesquisadoras em encontros, reuniões, ensaios e apresentações de espetáculos envolvendo as organizações pesquisadas. A pesquisa, predominantemente qualitativa e longitudinal gerou reflexões ante os dados coletados, com destaque para a história do Erro Grupo, que apresentou um forte distanciamento de seus propósitos iniciais ao longo de sua trajetória, por direcionar suas ações à captação de recursos junto às fontes financiadoras em detrimento de sua dedicação às atividades teatrais.

  14. Actitud Positiva: la base para la competitividad

    Directory of Open Access Journals (Sweden)

    Marco Anderson Espinoza

    2008-04-01

    Full Text Available Una estrategia empresarial enfocado en el mejoramiento continuo de la productividad para la competitividad, depende significativamente del manejo inteligente de tres variables visibles:Calidad, Entrega oportuna y Costo. No obstante, estas tres variables no suelen sersuficientes. La estrategia debe ser complementada con el manejo adecuado de variables intangibles como la Motivación y las Condiciones de Trabajo, con la aplicación de Tecnología Ambientalmente Amigable, en un marco de Actitud Positiva.A final de cuentas, la Actitud Positiva es fundamental para el recurso humano de cualquier organización, a fin de construir una plataforma sólida y estable que sirva de base para soportar un proceso sostenible de mejoramiento de la productividad, para aumentar la competitividad como estrategia empresarial exitosa.

  15. A novel louvered fin design to enhance thermal and drainage performances during periodic frosting/defrosting conditions

    International Nuclear Information System (INIS)

    Kim, Min-Hwan; Kim, Hisuk; Kim, Dong Rip; Lee, Kwan-Soo

    2016-01-01

    Highlights: • Thermal and drainage performances of a novel design louvered fin were investigated. • The thermal performance of the asymmetric fin was improved in the re-frosting cycle. • The asymmetric louvered fin exhibited better drainage on the leading edge of fins. • Lower surface tension between fin surface and water droplet improved the drainage. - Abstract: The retention water on fin surface can significantly degrade the thermal performance of heat exchangers under periodic frosting/defrosting conditions, which also leads to a decrease in the energy efficiency of air-source heat pumps. A novel louvered fin design was suggested to improve the drainage and the thermal performance of heat exchanger. The novel louvered fin had an asymmetric louver arrangement by flattening two louvers on the leading edge. The retention water formed on fin surface markedly decreased the heat transfer rate of the conventional symmetric louvered fins in re-frosting cycles. On the other hand, the asymmetric louvered fins improved the drainage performance of the retention water, which enhanced the heat transfer rate. To identify the reason of the difference in drainage performance between two fin geometries, additional experiments were carried out with enlargement models. The improvement in drainage performance of the asymmetric fin design originated from the lowered surface tension between the fin surface and water droplet.

  16. Methods and criteria for safety analysis (FIN L2535)

    International Nuclear Information System (INIS)

    1992-12-01

    In response to the NRC request for a proposal dated October 20, 1992, Westinghouse Savannah River Company (WSRC) submit this proposal to provide contractural assistance for FIN L2535, ''Methods and Criteria for Safety Analysis,'' as specified in the Statement of Work attached to the request for proposal. The Statement of Work involves development of safety analysis guidance for NRC licensees, arranging a workshop on this guidance, and revising NRC Regulatory Guide 3.52. This response to the request for proposal offers for consideration the following advantages of WSRC in performing this work: Experience, Qualification of Personnel and Resource Commitment, Technical and Organizational Approach, Mobilization Plan, Key Personnel and Resumes. In addition, attached are the following items required by the NRC: Schedule II, Savannah River Site - Job Cost Estimate, NRC Form 189, Project and Budget Proposal for NRC Work, page 1, NRC Form 189, Project and Budget Proposal for NRC Work, page 2, Project Description

  17. Heat flow in a He II filled fin

    International Nuclear Information System (INIS)

    Warren, R.P.

    1984-01-01

    This chapter demonstrates the influence of diameter, length, Kapitza conductance and temperature on the heat carrying capacity of an externally cooled, circular He II filled channel with zero net mass flow and of negligible wall thermal resistance. Topics considered include the internal convection mechanism and the heat transfer model (boundary conditions, solution procedure). The large apparent thermal conductivity of He-II is explained by the two fluid model as an internal convection in which there is a counter flow of the normal and superfluids with no net mass flow. A separate bath is considered in which an He-IIp (pressurized superfluid helium) filled fin is immersed which extends from the heated reservoir. A single heat sink can serve multiple heat sources

  18. Estudio y desarrollo de un vivero hortícola para el autoabastecimiento de comunidades infantiles vulnerables (Bushbuckridge, Mpumalanga; Sudáfrica)

    OpenAIRE

    Ganchegui Ganchegui, Iosu

    2010-01-01

    El presente trabajo fin de carrera ha tenido como principal objetivo estudiar las posibilidades existentes en la región de Bushbuckridge, en la provincia de Mpumalanga (República de Sudáfrica) de crear un vivero hortícola para el autoabastecimiento de las huertas de los proyectos. Además se ensayaron distintos sustratos y contenedores con el fin de elegir los más adecuados para su uso en el semillero, se asistió a las huertas con el fin de mejorar la producción y abastecer de plántula de c...

  19. "Pistolas para el Niño, Muñecas para la Niña"

    OpenAIRE

    Gianini Belotti, Elena

    2004-01-01

    Educere:Una Brizna de Aliento en el Tiempo Rivas, Pedro El Paradigma Reinante y su Paideia Alonso, Leonor La Experiencia Contemporánea como Expresión del Fin de una ÉticaAlgunas Ideas desde la Postmodernidad para Releer el Dato Educativo Perdomo, José Camilo La Sociedad del Conocimiento y el Fin de la Escuela Rodríguez Rojas, Pedro Escuela, Alteridad y Experiencia de SíLa Producción Pedagógica del Sujeto Valera Villegas, G...

  20. Relying on fin erosion to identify hatchery-reared brown trout in a Tennessee river

    Science.gov (United States)

    Meerbeek, Jonathan R.; Bettoli, Phillip William

    2012-01-01

    Hatchery-induced fin erosion can be used to identify recently stocked catchable-size brown trout Salmo trutta during annual surveys to qualitatively estimate contributions to a fishery. However, little is known about the longevity of this mark and its effectiveness as a short-term (≤ 1 year) mass-marking technique. We evaluated hatchery-induced pectoral fin erosion as a mass-marking technique for short-term stocking evaluations by stocking microtagged brown trout in a tailwater and repeatedly sampling those fish to observe and measure their pectoral fins. At Dale Hollow National Fish Hatchery, 99.1% (228 of 230) of microtagged brown trout in outdoor concrete raceways had eroded pectoral fins 1 d prior to stocking. Between 34 and 68 microtagged and 26-35 wild brown trout were collected during eight subsequent electrofishing samples. In a blind test based on visual examination of pectoral fins at up to 322 d poststocking, one observer correctly identified 91.7% to 100.0% (mean of 96.9%) of microtagged brown trout prior to checking for microtags. In the laboratory, pectoral fin length and width measurements were recorded to statistically compare the fin measurements of wild and microtagged hatchery brown trout. With only one exception, all pectoral fin measurements on each date averaged significantly larger for wild trout than for microtagged brown trout. Based on the number of pectoral fin measurements falling below 95% prediction intervals, 93.7% (148 of 158) of microtagged trout were correctly identified as hatchery fish based on regression models up to 160 d poststocking. Only 72.2% (70 of 97) of microtagged trout were identified correctly after 160 d based on pectoral fin measurements and the regression models. We concluded that visual examination of pectoral fin erosion was a very effective way to identify stocked brown trout for up to 322 d poststocking.

  1. Computational investigation of heat transfer and pressure drop in a typical louver fin-and-tube heat exchanger for various louver angles and fin pitches

    Directory of Open Access Journals (Sweden)

    Okbaz Abdulkerim

    2017-01-01

    Full Text Available In this study 3-D numerical simulations on heat transfer and pressure drop characteristics for a typical louver fin-and- double-row tube heat exchanger were carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles, fin pitch and Reynolds number, and reported in terms of Colburn j-factor and Fanning friction factor f. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles between 20° ≤Ө≤ 30°, louver pitch of Lp=3.8 mm and frontal velocities of U between 1.22 m/s - 3 m/s. In addition, flow visualization of detailed flow features results, such as velocity vectors, streamlines and temperature counters have been shown to understand heat transfer enhancement mechanism. The present results indicated that louver angle and fin pitch noticeably affected the thermal and hydraulic performance of heat exchanger. It has been seen that increasing louver angle, increases thermal performance while decreasing hydraulic performance associated to pressure drop for fin pitches of 3.2 mm and 2.5 mm. Fin pitch determines the flow behaviour that for fin pitch of 2 mm, increasing louver angle decreased heat transfer and pressure drop. Velocity vectors and streamlines give considerable information about the flow whether it is duct directed or louver directed. For all conditions the flow is louver directed.

  2. Ontogenetic scaling of caudal fin shape in Squalus acanthias (Chondrichthyes, Elasmobranchii): a geometric morphometric analysis with implications for caudal fin functional morphology.

    Science.gov (United States)

    Reiss, Katie L; Bonnan, Matthew F

    2010-07-01

    The shark heterocercal caudal fin and its contribution to locomotion are of interest to biologists and paleontologists. Current hydrodynamic data show that the stiff dorsal lobe leads the ventral lobe, both lobes of the tail are synchronized during propulsion, and tail shape reflects its overall locomotor function. Given the difficulties surrounding the analysis of shark caudal fins in vivo, little is known about changes in tail shape related to ontogeny and sex in sharks. A quantifiable analysis of caudal fin shape may provide an acceptable proxy for inferring gross functional morphology where direct testing is difficult or impossible. We examined ontogenetic and sex-related shape changes in the caudal fins of 115 Squalus acanthias museum specimens, to test the hypothesis that significant shape changes in the caudal fin shape occur with increasing size and between the sexes. Using linear and geometric morphometrics, we examined caudal shape changes within the context of current hydrodynamic models. We found no statistically significant linear or shape difference between sexes, and near-isometric scaling trends for caudal dimensions. These results suggest that lift and thrust increase linearly with size and caudal span. Thin-plate splines results showed a significant allometric shape change associated with size and caudal span: the dorsal lobe elongates and narrows, whereas the ventral lobe broadens and expands ventrally. Our data suggest a combination of caudal fin morphology with other body morphology aspects, would refine, and better elucidate the hydrodynamic factors (if any) that underlie the significant shape changes we report here for S. acanthias.

  3. Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

    Science.gov (United States)

    Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

    2017-10-01

    The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

  4. 情报研究在FinTech实践中的应用展望%The Application Prospect of Information Science in FinTech Practice

    Institute of Scientific and Technical Information of China (English)

    徐扬; 刘姝雯; 腾菲; 罗晶

    2017-01-01

    [目的/意义]针对金融科技(FinTech)发展的特征、现状及问题,探究情报学知识和技术在FinTech实践中的应用和发展方向.[方法/过程]梳理Fintech概念在国内外的发展历程和现状,并从情报学视角,讨论FinTech在特征、应用、监管等方面的研究展望,提出相应的建议.[结果/结论]研究结果表明,情报学与FinTech相辅相成,共同发展.未来,可以进一步强化FinTech业务的信息化与数字化,加强情报分析、商务智能以及情报学视角的大数据分析,为FinTech的发展注入更多的活力.

  5. Fin de partida de Samuel Beckett: La soberanía del lenguaje y el juego metateatral

    Directory of Open Access Journals (Sweden)

    Carolina Brncic

    2014-05-01

    Full Text Available El artículo analiza Fin de partida de Samuel Beckett como obra metateatral. Para abordar el problema del género se examinan cuatro enfoques críticos relevantes: la teoría de Martin Esslin sobre el Teatro del Absurdo, la interpretación de Theodor Adorno como drama de la descomposición, la lectura de Christoph Menke como una tragedia de la representación y la propuesta de Lionel Abel sobre el metateatro. A partir de la definición señalada por Abel, se analiza la obra atendiendo a dos dimensiones paradigmáticas: la noción de juego representacional como drama autorreflexivo y la soberanía del lenguaje como soporte dramático.

  6. 3-D NUMERICAL STUDY AND COMPARISON OF ECCENTRIC AND CONCENTRIC ANNULAR-FINNED TUBE HEAT EXCHANGERS

    Directory of Open Access Journals (Sweden)

    FAROUK TAHROUR

    2015-11-01

    Full Text Available The use of 3-D computational fluid dynamics (CFD is proposed to simulate the conjugate conduction-convection of heat transfer problems in eccentric annularfinned tube heat exchangers. The numerical simulation results allow us to evaluate the heat transfer coefficient over fin surfaces, the fin efficiency and the pressure drop. The aim of the present paper is to determine the optimum tube position in the circular fin that maximizes heat dissipation and minimizes pressure drop. In addition, this study analyzes the effects of fin spacing and fin tube diameter on heat transfer and flow characteristics for a range of Reynolds numbers, 4500≤Re≤22500. A satisfactory qualitative and quantitative agreement was obtained between the numerical predictions and the results published in the literature. For small fin spacings, the eccentric annular finned tube is more efficient than the concentric one. Among the cases examined, the average heat transfer coefficient of the eccentric annular-finned tube, for a tube shift St =12 mm and a Reynolds number Re = 9923, was 7.61% greater than that of the concentric one. This gain is associated with a 43.09% reduction in pressure drop.

  7. State of FinTech in Europe: Mutation perspectives of the banking sector

    OpenAIRE

    Marasco, Marco

    2017-01-01

    This paper studies the relationship between FinTech start-ups and the banking sector. The aim is to assess the impact that the FinTech sector might have on the business model and profitability of banks. Master [120] en sciences de gestion (Mons), Université catholique de Louvain, 2017

  8. A Comparative Study of Conventional and Tip-Fin Propeller Performance

    DEFF Research Database (Denmark)

    Andersen, Poul

    1997-01-01

    During more than a decade several attempts have been made to obtain higher propeller efficiencies by radically modifying the geometry in the tip region of the blade. In the tip-fin propeller a tip fin or winglet is attached to the blade tip and integrated into the blade in such a way that the bla...

  9. Thermal performance of circular convective–radiative porous fins with different section shapes and materials

    International Nuclear Information System (INIS)

    Hatami, M.; Ganji, D.D.

    2013-01-01

    Graphical abstract: - Highlights: • LSM is an accurate technique for simulating heat transfer in circular porous fins. • Rectangular, convex, triangular and exponential variable sections are considered. • Radiation and convection from porous fin are considered. • Effects of material and geometry on heat transfer from fins are studied. - Abstract: In this study, heat transfer and temperature distribution equations for circular convective–radiative porous fins are presented. It’s assumed that the thickness of circular fins varies with radius so four different shapes, rectangular, convex, triangular and exponential, are considered. The heat transfer through porous media is simulated using passage velocity from the Darcy’s model. After deriving equation for each geometry, Least Square Method (LSM) and fourth order Runge–Kutta method (NUM) are applied for predicting the temperature distribution in the porous fins. The selected porous fin’s materials are Al, SiC, Cu and Si 3 N 4 . Results reveal that LSM has very effective and accurate in comparison with the numerical results. As a main outcome, Si 3 N 4 -exponential section fin has the maximum amount of transferred heat among other fins

  10. A Numerical Study of Natural Convection Heat Transfer in Fin Ribbed Radiator

    Directory of Open Access Journals (Sweden)

    Hua-Shu Dou

    2015-01-01

    Full Text Available This paper numerically investigates the thermal flow and heat transfer by natural convection in a cavity fixed with a fin array. The computational domain consists of both solid (copper and fluid (air areas. The finite volume method and the SIMPLE scheme are used to simulate the steady flow in the domain. Based on the numerical results, the energy gradient function K of the energy gradient theory is calculated. It is observed from contours of the temperature and energy gradient function that the position where thermal instability takes place correlates well with the region of large K values, which demonstrates that the energy gradient method reveals the physical mechanism of the flow instability. Furthermore, the effects of the fin height, the fin number, and the fin shape on the heat transfer rate are also investigated. It is found that the thermal performance of the fin array is determined by the combined effect of the fin space and fin height. It is also observed that the effect of fin shape on heat transfer is insignificant.

  11. Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis)

    DEFF Research Database (Denmark)

    Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta

    2016-01-01

    The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses....

  12. Performance Analysis of a Self-Propelling Flat Plate Fin with Joint Compliance

    Science.gov (United States)

    Reddy, N. Srinivasa; Sen, Soumen; Pal, Sumit; Shome, Sankar Nath

    2017-12-01

    Fish fin muscles are compliant and they regulate the stiffness to suit different swimming conditions. This article attempts to understand the significance of presence of compliance in fin muscle with help of a flexible joint flat plate fin model. Blade element method is employed to model hydrodynamics and to compute the forces of interaction during motion of the plate within fluid. The dynamic model of self-propelling fin is developed through multi-body dynamics approach considering the hydrodynamic forces as external forces acting on the fin. The derived hydrodynamic model is validated with experiments on rigid flat plate fin. The effect of the joint stiffness and flapping frequency on the propulsion speed and efficiency is investigated through simulations using the derived and validated model. The propulsion efficiency is found to be highly influenced by the joint stiffness at a given flapping frequency. The fin attained maximum propulsion efficiency when the joint stiffness is tuned to a value at which flapping frequency matches near natural frequency of the fin. At this tuned joint stiffness and flapping frequency, the resulted Strouhal numbers are observed to fall within the optimum range (0.2 to 0.4) for maximized propulsion efficiency of flying birds and swimming aquatic animals reported in literature.

  13. Mediterranean Fin Whales (Balaenoptera physalus) Threatened by Dolphin MorbilliVirus.

    Science.gov (United States)

    Mazzariol, Sandro; Centelleghe, Cinzia; Beffagna, Giorgia; Povinelli, Michele; Terracciano, Giuliana; Cocumelli, Cristiano; Pintore, Antonio; Denurra, Daniele; Casalone, Cristina; Pautasso, Alessandra; Di Francesco, Cristina Esmeralda; Di Guardo, Giovanni

    2016-02-01

    During 2011-2013, dolphin morbillivirus was molecularly identified in 4 stranded fin whales from the Mediterranean Sea. Nucleoprotein, phosphoprotein, and hemagglutinin gene sequences of the identified strain were highly homologous with those of a morbillivirus that caused a 2006-2007 epidemic in the Mediterranean. Dolphin morbillivirus represents a serious threat for fin whales.

  14. Heat transfer from rotating finned heat exchangers with different orientation angles

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, Adel Abdalla [Suez Canal University, Marine Engineering and Naval Architecture Department, Faculty of Engineering, Port Said (Egypt)

    2010-03-15

    The local and average heat transfer characteristics of spoke like fins that extend outward from a rotating shaft have been determined experimentally. The experiments encompassed a number of geometrical parameters, including the length and chord of the fins, the number of fins deployed around the circumference of the shaft and the orientation angles of the fin. The experiments cover a wider range of rotational speeds, which varies from 25 up to 2,000 rpm. Three wire heat flux sensors have been used in conjunction with a slip ring apparatus to evaluate the local and average heat transfer coefficients. The output results indicated that, the heat transfer transition on rotating fins occurs at Reynolds number lower than encountered on the stationary rectangular fins in crossflow. In general, with non zero incidence angle, the rotating system acts as a fan and creates axial air motion, which enhance the heat transfer rate. However, the effect of orientation angle reduces with increasing the rotational speed. The Nusselt number data are independent of the number of fins in the circumferential array at high rotational speed and are weakly dependent at low Reynolds numbers. To facilitate the use of the results for design, correlations were developed which represent the fin heat transfer coefficient as a continuous function of the investigated independent parameters. (orig.)

  15. Experimental Study on Cooling Heat Transfer of Supercritical Carbon Dioxide Inside Horizontal Micro-Fin Tubes

    Science.gov (United States)

    Kuwahara, Ken; Higashiiu, Shinya; Ito, Daisuke; Koyama, Shigeru

    This paper deals with the experimental study on cooling heat transfer of supercritical carbon dioxide inside micro-fin tubes. The geometrical parameters in micro-fin tubes used in the present study are 6.02 mm in outer diameter, 4.76 mm to 5.11 mm in average inner diameter, 0.15 mm to 0.24 mm in fin height, 5 to 25 in helix angle, 46 to 52 in number of fins and 1.4 to 2.3 in area expansion ratio. Heat transfer coefficients were measured at 8-10 MPa in pressure, 360-690 kg/(m2•s) in mass velocity and 20-75 °C in CO2 temperature. The measured heat transfer coefficients of micro-fin tubes were 1.4 to 2 times higher than those of the smooth tube having 4.42 in inner diameter. The predicted heat transfer coefficients using the correlation equation, which was developed for single-phase turbulent fluid flow inside micro-fin-tubes, showed large deviations to the measured values. The new correlation to predict cooling heat transfer coefficient of supercritical carbon dioxide inside micro-fin tubes was developed taking into account the shape of fins based on experimental data empirically. This correlation equation agreed within ±20% of almost all of the experimental data.

  16. Sistema de autenticidad para aplicaciones de análisis de eventos para seguridad.

    OpenAIRE

    ESCAMILLA PARDO, TONI

    2017-01-01

    [ES] En este proyecto se afronta la creación de un sistema distribuido capaz de garantizar, en aplicaciones empleadas para el análisis de eventos de seguridad, la autenticidad de los datos transmitidos entre el host cliente y servidor con el fin de asegurar la integridad de los mismos en la transmisión entre ambas partes, así como evitar la posible alteración en el destino. Para ello, se utilizará la tecnología blockchain a modo de base de datos en la que se almacenen los hashe...

  17. Experimental studies of Savonius wind turbines with variations sizes and fin numbers towards performance

    Science.gov (United States)

    Utomo, Ilham Satrio; Tjahjana, Dominicus Danardono Dwi Prija; Hadi, Syamsul

    2018-02-01

    The use of renewable energy in Indonesia is still low. Especially the use of wind energy. Wind turbine Savonius is one turbine that can work with low wind speed. However, Savonius wind turbines still have low efficiency. Therefore it is necessary to modify. Modifications by using the fin are expected to increase the positive drag force by creating a flow that can enter the overlap ratio of the gap. This research was conducted using experimental approach scheme. Parameters generated from the experiment include: power generator, power coefficient, torque coefficient. The experimental data will be collected by variation of fin area, horizontal finning, at wind speed 3 m/s - 4,85 m/s. Experimental results show that with the addition of fin can improve the performance of wind turbine Savonius 11%, and by using the diameter of 115 mm fin is able to provide maximum performance in wind turbine Savonius.

  18. Combined natural convection heat and mass transfer from vertical fin arrays

    International Nuclear Information System (INIS)

    Giri, A.; Narasimham, G.S.V.L.; Krishna Murthy, M.V.

    2003-01-01

    Natural convection transport processes play an important role in many applications like ice-storage air-conditioning. A mathematical formulation of natural convection heat and mass transfer over a shrouded vertical fin array is developed. The base plate is maintained at a temperature below the dew point of the surrounding moist air. Hence there occurs condensation of moisture on the base plate, while the fins may be partially or fully wet. A numerical study is performed by varying the parameters of the problem. The local and average Nusselt numbers decrease in streamwise direction and tend to approach fully developed values for sufficiently large values of the fin length. The results show that beyond a certain streamwise distance, further fin length does not improve the sensible and latent heat transfer performance, and that if dry fin analysis is used under moisture condensation conditions, the overall heat transfer will be underestimated by about 50% even at low buoyancy ratios

  19. Laminar fluid flow and heat transfer in a fin-tube heat exchanger with vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, J.I.; Rodriques, R. Jr. [Polytechnic School of Univ. of Sao Paolo, Sao Paolo (Brazil). Dept. of Mechanical Engineering

    1996-12-31

    Development of heat transfer enhancement techniques for fin-tube heat exchangers has great importance in industry. In recent years, heat transfer augmentation by vortex generators has been considered for use in plate fin-tube heat exchangers. The present work describes a numerical investigation about the influence of delta winglet pairs of vortex generators on the flow structure and heat transfer of a plate fin-tube channel. The Navier-Stokes and Energy equations are solved by the finite volume method using a boundary-fitted coordinate system. The influence of vortex generators parameters such as position, angle of attack and aspect ratio were investigated. Local and global influences of vortex generators in heat transfer and flow losses were analyzed by comparison with a model using smooth fin. The results indicate great advantages of this type of geometry for application in plate fin-tube heat exchangers, in terms of large heat transfer enhancement and small pressure loss penalty. (author)

  20. Performance analysis of pin fins with temperature dependent thermal parameters using the variation of parameters method

    Directory of Open Access Journals (Sweden)

    Cihat Arslantürk

    2016-08-01

    Full Text Available The performance of pin fins transferring heat by convection and radiation and having variable thermal conductivity, variable emissivity and variable heat transfer coefficient was investigated in the present paper. Nondimensionalizing the fin equation, the problem parameters which affect the fin performance were obtained. Dimensionless nonlinear fin equation was solved with the variation of parameters method, which is quite new in the solution of nonlinear heat transfer problems. The solution of variation of parameters method was compared with known analytical solutions and some numerical solution. The comparisons showed that the solutions are seen to be perfectly compatible. The effects of problem parameters were investigated on the heat transfer rate and fin efficiency and results were presented graphically.

  1. Laminar fluid flow and heat transfer in a fin-tube heat exchanger with vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, J I; Rodriques, R Jr [Polytechnic School of Univ. of Sao Paolo, Sao Paolo (Brazil). Dept. of Mechanical Engineering

    1997-12-31

    Development of heat transfer enhancement techniques for fin-tube heat exchangers has great importance in industry. In recent years, heat transfer augmentation by vortex generators has been considered for use in plate fin-tube heat exchangers. The present work describes a numerical investigation about the influence of delta winglet pairs of vortex generators on the flow structure and heat transfer of a plate fin-tube channel. The Navier-Stokes and Energy equations are solved by the finite volume method using a boundary-fitted coordinate system. The influence of vortex generators parameters such as position, angle of attack and aspect ratio were investigated. Local and global influences of vortex generators in heat transfer and flow losses were analyzed by comparison with a model using smooth fin. The results indicate great advantages of this type of geometry for application in plate fin-tube heat exchangers, in terms of large heat transfer enhancement and small pressure loss penalty. (author)

  2. Determination of optimum fin profile for a zero-G capillary drained condenser

    Science.gov (United States)

    Mccormick, John A.; Valenzuela, Javier A.; Choudhury, Dipanker

    1990-01-01

    This paper presents the analytical formulation and numerical results for heat transfer in a high heat flux condenser that relies on capillary flow along shaped fins (Gregorig surfaces) and a drainage network embedded in the condenser walls. Results are shown for a variety of fin profile shapes in order to show the geometric trade-offs involved in seeking a maximum effective heat transfer coefficient for the fin. Predictions of the model show excellent agreement with previously reported measurements for steam. Based on this work, a profile has been selected for a 2 kW ammonia condenser currently under development for use in space. In that design the fin half width is 0.5 mm and the model predicts a heat transfer coefficient referred to the base of the fin of 9 W/sq cm deg C for a heat flux of 10/W sq cm at the base.

  3. Optimization of convective-radiative fins by using differential quadrature element method

    International Nuclear Information System (INIS)

    Malekzadeh, P.; Rahideh, H.; Karami, G.

    2006-01-01

    A first endeavor to exploit the differential quadrature element method (DQEM) as a simple, accurate and computationally efficient numerical tool for the shape optimization of convective-radiating extended surfaces or fins is made. The formulations are general so that the spatial and spatial-temperature dependent geometrical and thermal parameters can easily be implemented. The thermal conductivity of the fin is assumed to vary as a linear function of the temperature. The effects of a convective-radiative condition at the fin tip and effective convective condition at the fin base are considered. The optimization of fins with uniform and step cross-sections is investigated. The accuracy of the method is demonstrated by comparing its results with those generated by Adomian's decomposition technique, Taylor transformation technique and finite difference method. It is shown that, using few grid points, highly accurate results are obtained. Less computational effort of the method with respect to the finite difference method is shown

  4. Bio-inspired flexible joints with passive feathering for robotic fish pectoral fins.

    Science.gov (United States)

    Behbahani, Sanaz Bazaz; Tan, Xiaobo

    2016-05-04

    In this paper a novel flexible joint is proposed for robotic fish pectoral fins, which enables a swimming behavior emulating the fin motions of many aquatic animals. In particular, the pectoral fin operates primarily in the rowing mode, while undergoing passive feathering during the recovery stroke to reduce hydrodynamic drag on the fin. The latter enables effective locomotion even with symmetric base actuation during power and recovery strokes. A dynamic model is developed to facilitate the understanding and design of the joint, where blade element theory is used to calculate the hydrodynamic forces on the pectoral fins, and the joint is modeled as a paired torsion spring and damper. Experimental results on a robotic fish prototype are presented to illustrate the effectiveness of the joint mechanism, validate the proposed model, and indicate the utility of the proposed model for the optimal design of joint depth and stiffness in achieving the trade-off between swimming speed and mechanical efficiency.

  5. Experimental Study of Heat Transfer Enhancements from Array of Alternate Rectangular Dwarf Fins at Different Inclinations

    Science.gov (United States)

    Awasarmol, Umesh Vandeorao; Pise, Ashok T.

    2018-02-01

    The main objective of this experimental work is to investigate and compare heat transfer enhancement of alternate dwarf fin array at different angles of inclination. In this study, the steady state heat transfer from the full length fin arrays and alternate dwarf fin arrays are measured in natural convection and radiation environment. Largest increase in the Nusselt number was achieved with alternate dwarf fin at angle of orientation 90°, which shows about 28% enhanced heat transfer coefficient as opposed to the full-length fin array with 25% saving in material. In case of non-black FAB, contribution of radiation heat transfer is found to be very small nearly within 1% of the heater input. After coating lamp black contribution of radiation heat transfer is found to increase to about 3-4% of the heater input in the range of temperatures considered in this study.

  6. The use of pelvic fins for benthic locomotion during foraging behavior in Potamotrygon motoro (Chondrichthyes: Potamotrygonidae

    Directory of Open Access Journals (Sweden)

    Akemi Shibuya

    2015-06-01

    Full Text Available Synchronized bipedal movements of the pelvic fins provide propulsion (punting during displacement on the substrate in batoids with benthic locomotion. In skates (Rajidae this mechanism is mainly generated by the crural cartilages. Although lacking these anatomical structures, some stingray species show modifications of their pelvic fins to aid in benthic locomotion. This study describes the use of the pelvic fins for locomotory performance and body re-orientation in the freshwater stingray Potamotrygon motoro (Müller & Henle, 1841 during foraging. Pelvic fin movements of juvenile individuals of P. motoro were recorded in ventral view by a high-speed camera at 250-500 fields/s-1. Potamotrygon motoro presented synchronous, alternating and unilateral movements of the pelvic fins, similar to those reported in skates. Synchronous movements were employed during straightforward motion for pushing the body off the substrate as well as for strike feeding, whereas unilateral movements were used to maneuver the body to the right or left during both locomotion and prey capture. Alternating movements of the pelvic fins are similar to bipedal movements in terrestrial and semi-aquatic tetrapods. The pelvic fins showed coordinated movements during feeding even when stationary, indicating that they have an important function in maintaining body posture (station holding during prey capture and manipulation. The use of pelvic fins during prey stalking may be advantageous because it results in less substrate disturbance when compared to movements generated by pectoral fin undulation. The range of pelvic fin movements indicates more complex control and coordination of the pelvic radial muscles.

  7. Performance investigation of an innovative offset strip fin arrays in compact heat exchangers

    International Nuclear Information System (INIS)

    Peng, Hao; Ling, Xiang; Li, Juan

    2014-01-01

    Highlights: • The effect of fin pitch, length and bending distance on thermal performance were presented. • The corresponding Re C values at the j and f slope changes are in the range of 2000–2100. • The numerical results showed a good agreement with the experimental data. • Local high Nu values near the channel inlet, decreasing through the flow directions. - Abstract: Experimental and numerical studies on the flow and heat transfer characteristics for an innovative offset strip fins compact heat exchangers were performed. First, five fin schemes were investigated with various air flow velocities and a constant inlet steam pressure by experiments. The Reynolds number ranged from 500 to 5000 at the air side. The experimental results indicated that the fin pitch (P f ), fin length (L f ) and fin bending distance (C f ) have a significant influence on thermal performance of fins. The Colburn factor j, friction factor f and ‘point of transition’ were calculated from the experimental data. Then, the thermal–hydraulic performances of the novel offset strip fins were analyzed numerically. The simulation results obtained are in agreement with experimental data. Based on these simulations, the maximum values for local Nu number are at the channel inlet which is due to the thermal entrance effect. The longitudinal vortexes near the fin region will increase velocity gradient and reduce the thickness of boundary layer to improve heat transfer. The main conclusion draws from this work will be helpful for future development and design of a high-efficiency heat exchangers involving offset strip fin structures

  8. Self-propelled heaving and pitching flexible fin in a quiescent flow

    International Nuclear Information System (INIS)

    Kim, Boyoung; Park, Sung Goon; Huang, Weixi; Sung, Hyung Jin

    2016-01-01

    Highlights: • A self-propelled flexible fin with heaving and pitching motions in a quiescent flow has been simulated by using the penalty immersed boundary method. • The cruising speed and the swimming efficiency of the self-propelled fin were determined as functions of the bending coefficient (γ), the heaving amplitude (A_h). • We optimized the cruising speed and the swimming efficiency with respect to γ, f, A_h, A_p, and Δϕ. - Abstract: A self-propelled flexible fin with heaving and pitching motions in a quiescent flow has been simulated by using the penalty immersed boundary method. The flexible fin can move freely in the horizontal direction and the body of the flexible fin moves passively along with the active head motion. The position of the head of the fin was described as a harmonic heaving oscillation in the vertical direction, while the inclination angle of the head was prescribed as a harmonic oscillation with a moving clamped condition for the heaving and pitching fin. The cruising speed and the swimming efficiency of the self-propelled fin were determined as functions of the bending stiffness (γ), the heaving amplitude (A_h), the pitching amplitude (A_p), the flapping frequency (f) and the phase difference (Δϕ) between A_h and A_p. We optimized the cruising speed and the swimming efficiency with respect to γ, f, A_h, A_p and Δϕ. For a certain range of A_p, the swimming efficiency of the heaving and pitching fin is larger than that of a heaving-only fin.

  9. A numerical method for PCM-based pin fin heat sinks optimization

    International Nuclear Information System (INIS)

    Pakrouh, R.; Hosseini, M.J.; Ranjbar, A.A.; Bahrampoury, R.

    2015-01-01

    Highlights: • Optimization of PCM-based heat sink by using the Taguchi method. • Derivation of optimal PCM percentage to reach the maximum critical time. • Optimization is performed for four different critical temperatures. • Effective design factors are fins’ height and fins’ number. • The optimum configuration depends on geometric properties and the critical temperature. - Abstract: This paper presents a numerical investigation on geometric optimization of PCM-based pin fin heat sinks. Paraffin RT44HC is used as PCM while the fins and heat sink base is made of aluminum. The fins act as thermal conductivity enhancers (TCEs). The main goal of the study is to obtain the configurations that maximize the heat sink operational time. An approach witch couples Taguchi method with numerical simulations is utilized for this purpose. Number of fins, fins height, fins thickness and the base thickness are parameters which are studied for optimization. In this study natural convection and PCM volume variation during melting process are considered in the simulations. Optimization is performed for different critical temperatures of 50 °C, 60 °C, 70 °C and 80 °C. Results show that a complex relation exists between PCM and TCE volume percentages. The optimal case strongly depends on the fins’ number, fins’ height and thickness and also the critical temperature. The optimum PCM percentages are found to be 60.61% (corresponds to 100 pin fin heat sink with 4 mm thick fins) for critical temperature of 50 °C and 82.65% (corresponds to 100 pin fin heat sink with 2 mm thick fins) for other critical temperatures

  10. Characteristics and formation mechanism for stainless steel fiber with periodic micro-fins

    Science.gov (United States)

    Tang, Tao; Wan, Zhenping; Lu, Longsheng; Tang, Yong

    2016-05-01

    Metal fibers have been widely used in many industrial applications due to their unique advantages. In certain applications, such as catalyst supports or orthopedic implants, a rough surface or tiny outshoots on the surface of metal fibers to increase surface area are needed. However, it has not been concerned about the surface morphologies of metal fiber in the current research of metal fiber manufacturing. In this paper, a special multi-tooth tool composed of a row of triangular tiny teeth is designed. The entire cutting layer of multi-tooth tool bifurcates into several thin cutting layers due to tiny teeth involved in cutting. As a result, several stainless steel fibers with periodic micro-fins are produced simultaneously. Morphology of periodic micro-fins is found to be diverse and can be classified into three categories: unilateral plane, unilateral tapering and bilateral. There are two forming mechanisms for the micro-fins. One is that periodic burrs remained on the free side of cutting layer of a tiny tooth create micro-fins of stainless steel fiber produced by the next neighboring tiny tooth; the other is that the connections between two fibers stuck together come to be micro-fins if the two fibers are finally detached. Influence of cutting conditions on formation of micro-fins is investigated. Experimental results show that cutting depth has no significant effect on micro-fin formation, high cutting speed is conducive to micro-fin formation, and feed should be between 0.12 mm/r and 0.2 mm/r to reliably obtain stainless steel fiber with micro-fins. This research presents a new pattern of stainless steel fiber characterized by periodic micro-fins formed on the edge of fiber and its manufacturing method.

  11. Líneas actividades indicadores y metas estratégicas para el Plan de Mejoramiento Estratégico para el servicio de salud de la Institución Penitenciaria de Acacias

    OpenAIRE

    Rojas Gutiérrez, Dania Magnolia

    2013-01-01

    El presente trabajo tiene como objetivo establecer un plan de de mejoramiento estratégico que permita optimizar el servicio de salud de la Institución Penitenciaria de Acacias. Para lograr este fin se hace un análisis del sector carcelario y penitenciario en Colombia con el fin de identificar la problemática que lo viene afectando en los últimos años, se establece un diagnostico en la Penitenciaria de Acacias con el fin de establecer la problemática que existe en la prestación de servicio...

  12. Efecto del fin de semana y los festivos en los mercados de acciones: Un estudio comparativo entre Chile, Brasil, México y Colombia

    OpenAIRE

    Torres García, Carlos Alberto

    2010-01-01

    Resumen: En la investigación económica y financiera siempre ha sido una constante la discusión acerca de la eficiencia de los mercados y sus implicaciones en el desempeño de los negocios. El presente documento continua en esta línea de investigación analizando el efecto del fin de semana en el rendimiento y la volatilidad de los índices de las bolsas de Chile (IGPA), Brasil (IBOVESPA), México (IPC) y Colombia (IGBC). Para esto se utilizan datos de cierre diarios de los respectivos índic...

  13. Caracterización de un robot para aplicaciones de mecanizado con requerimientos de tolerancias

    OpenAIRE

    Ferreras Higuero, Eugenio

    2014-01-01

    El presente Trabajo fin Fin de Máster, versa sobre una caracterización preliminar del comportamiento de un robot de tipo industrial, configurado por 4 eslabones y 4 grados de libertad, y sometido a fuerzas de mecanizado en su extremo. El entorno de trabajo planteado es el de plantas de fabricación de piezas de aleaciones de aluminio para automoción. Este tipo de componentes parte de un primer proceso de fundición que saca la pieza en bruto. Para series medias y altas, en función de las pr...

  14. Effect of morphological fin curl on the swimming performance and station-holding ability of juvenile shovelnose sturgeon

    Science.gov (United States)

    Deslauriers, David; Johnston, Ryan; Chipps, Steven R.

    2016-01-01

    We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index < 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

  15. Effects of fin pitch and array of the frost layer growth on extended surface of a heat exchanger

    International Nuclear Information System (INIS)

    Yang, Dong Keun; Lee, Kwan Soo

    2003-01-01

    This paper presents the effects of the fin array and pitch on the frost layer growth of a heat exchanger. The numerical results are compared with experimental data of a cold plate to validate the present model, and agree well with experimental data within a maximum error of 8%. The characteristics of the frost formation on staggered fin array are somewhat different from those of in-line array. For fin pitch below 10 mm, the frost layer growth of second fin in the staggered array is affected by that of first fin. The heat transfer of single fin deteriorate with decreasing fin pitch regardless of fin array, however, the thermal performance of a heat exchanger, considering increase of heat surface area, becomes better

  16. Analysis and Evaluation of a Vapor-Chamber Fin-Tube Radiator for High-Power Rankine Cycles

    National Research Council Canada - National Science Library

    Haller, Henry

    1965-01-01

    An analytical investigation of a flat, direct- condensing fin-tube radiator employing segmented vapor-chamber fins as a means of improving heat rejection was performed A for illustrative high-power...

  17. Boiling on fins with wire screen of variable effective conductivity

    Directory of Open Access Journals (Sweden)

    Orzechowski Tadeusz

    2017-01-01

    Full Text Available The high scale of integration of modern equipment used for medical, military and other purposes puts heavy demands as regards the removal of great heat fluxes. This can be achieved only in exchangers that apply the phase change phenomena. Among many methods to improve boiling heat transfer, the wire mesh covering demonstrates some advantages due to the possibilities of designing the desired microstructure parameters, availability on the market, and low cost. The wire mesh microstucture with specified geometrical parameters produces anisotropy in conductivity. The different arrangement of the mesh layers relative to the direction of the heat flux is a cause of the change of temperature distribution within the layer. The consequence is a respective change in the discharge conditions of the gas phase and liquid feed. The experiments were conducted on fins covered with a single layer of copper mesh with lumen of 38 % and boiling FC-72 at ambient pressure. Compared with the smooth surface, the wire mesh structures yield an increase in the heat transfer rate at boiling. It is also shown that nucleate boiling is initiated at lower wall superheat. Formulas for longitudinal and perpendicular thermal conductivity are given for different mesh structure arrangements.

  18. 新加坡FinTech生态系统建设及其启示%Singapore’s FinTech Ecological System Construction and Its Enlightenment

    Institute of Scientific and Technical Information of China (English)

    钟鸣长

    2016-01-01

    Since the financial crisis, the integration of finance and technology has become a new trend in global economic development, and become a hot issue in the political, business, and academic attention. Singapore government maps out a strategy and introduces a series of policies to build FinTech ecosystem, such as financial support, establishing FinTech SUB, and implementing regulatory sandbox. Thus, Singapore will transform the existing financial system, construct the FinTech hub, and become an intelligent country of S&T and intelligent financial center. However, Internet finance in China is still at the stage of FinTech1.0 currently, which appears to be fast, slant, and disordered. So it is urgent to be transformed and upgraded. Meanwhile, we should not only be fully aware of the necessity and urgency of FinTech ecosystem development, clarify the relation between Internet financial and FinTech, but also we should learn from Singapore’s advanced experience to develop the FinTech ecosystem in all aspects, for example, setting up specialized management institutions, determining specific development goals, providing financial support, promoting “Regulatory Sandbox”, mobilizing domestic and international market resources, and exerting the role of the government, market, and enterprises.%金融危机以来,金融与科技的融合成为全球经济发展的一股新潮流和趋势,成为政、商、学界关注的热点话题。新加坡从资金支持、搭建创业加速平台、推行监管沙盒等方面推出了打造FinTech生态系统的组合拳,旨在改造现有金融体系、建设FinTech枢纽中心,立志成为世界智慧科技大国和智慧金融中心。中国互联网金融目前总体上还处于FinTech1.0阶段,呈现一种“快、偏、乱”的现象,亟需转型与升级。因此,我们不仅要充分意识到FinTech产业发展的必要性和紧迫性,厘清互联网金融与FinTech的关系,而且要学习和借鉴新加

  19. Antraquinona e surfactante para otimizaçao do processo Kraft com Pinus Spp.

    OpenAIRE

    Mocelin, Ezequiel Zatoni

    2013-01-01

    A madeira de Pinus é atualmente a matéria-prima mais utilizada na obtenção de fibras longas para papel, juntamente com o processo Kraft pela sua versatilidade e por produzir fibras com boa resistência. As atuais perspectivas florestais apontam para uma escassez da madeira de Pinus para os diversos fins, seja para madeira processada, seja para celulose e papel. O processo Kraft tem como desvantagem o baixo rendimento em celulose, devido à solubilização não somente da lignina como também parte ...

  20. Characteristics of a micro-fin evaporator: Theoretical analysis and experimental verification

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2013-01-01

    Full Text Available A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good agreement with the experimental data. The results show that heat capacity and the heat transfer coefficient of the micro-fin evaporator increase with increasing logarithmic mean temperature difference, the water mass flow rate and the refrigerant mass flow rate. Heat capacity of the micro-fin evaporator for diameter 9.52 mm is higher than that of diameter 7.00 mm with using R290 as refrigerant. Heat capacity of the micro-fin evaporator with using R717 as refrigerant is higher than that of R290 as refrigerant. The results of this study can provide useful guidelines for optimal design and operation of micro-fin evaporator in its present or future applications.

  1. Design, Implementation and Control of a Fish Robot with Undulating Fins

    Directory of Open Access Journals (Sweden)

    Mohsen Siahmansouri

    2011-11-01

    Full Text Available Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

  2. CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

    International Nuclear Information System (INIS)

    Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan

    2012-01-01

    Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number

  3. Heat transfer and pressure drop characteristics of mini-fin structures

    International Nuclear Information System (INIS)

    Jiang Peixue; Xu Ruina

    2007-01-01

    Forced convection heat transfer of air and water in bronze and pure copper mini-fin structures and mini-channel structures was investigated experimentally. The mini-fin dimensions were 0.7 mm x 0.2 mm and 0.8 mm x 0.4 mm. The tests included both staggered diamond-shaped and in-line square mini-fin arrangements. The tests investigated the effects of structures, mini-fin dimensions and arrangement, test section materials, and fluid properties on the convection heat transfer and heat transfer enhancement. For the tested conditions, the convection heat transfer coefficient was increased 9-21 fold for water and 12-38 fold for air in the mini-fin structures compared with an empty plate channel. The friction factor and flow resistance in the mini-channel structures and the in-line square mini-fin arrangement were much less than in the staggered diamond-shaped mini-fin arrangement. For the small channel width, W c = 0.2 mm, the convection heat transfer with the in-line square array structure was more intense than with the staggered diamond-shaped structure, the mini-channel structure or the porous media. For the larger channel width, W c = 0.4 mm, the convection heat transfer in the staggered diamond-shaped array structure was more intense than in the others systems while the in-line square structure had the best overall thermal-hydraulic performance

  4. Thermal management of electronics using phase change material based pin fin heat sinks

    International Nuclear Information System (INIS)

    Baby, R; Balaji, C

    2012-01-01

    This paper reports the results of an experimental study carried out to explore the thermal characteristics of phase change material based heat sinks for electronic equipment cooling. The phase change material (PCM) used in this study is n – eicosane. All heat sinks used in the present study are made of aluminium with dimensions of 80 × 62 mm 2 base with a height of 25 mm. Pin fins acts as the thermal conductivity enhancer (TCE) to improve the distribution of heat more uniformly as the thermal conductivity of the PCM is very low. A total of three different pin fin heat sink geometries with 33, 72 and 120 pin fins filled with phase change materials giving rise to 4%, 9% and 15% volume fractions of the TCE respectively were experimentally investigated. Baseline comparisons are done with a heat sink filled with PCM, without any fin. Studies are conducted for heat sinks on which a uniform heat load is applied at the bottom for the finned and unfinned cases. The effect of pin fins of different volume fractions with power levels ranging from 4 to 8 W corresponding to a heat flux range of 1. 59 to 3.17 kW/m 2 , was explored in this paper. The volume fraction of the PCM (PCM volume / (Total volume – fin volume)) is also varied as 0. 3, 0.6 and 1 to determine the effect of PCM volume on the overall performance of the electronic equipment.

  5. Numerical studies of static aeroelastic effects on grid fin aerodynamic performances

    Directory of Open Access Journals (Sweden)

    Chengde HUANG

    2017-08-01

    Full Text Available The grid fin is an unconventional control surface used on missiles and rockets. Although aerodynamics of grid fin has been studied by many researchers, few considers the aeroelastic effects. In this paper, the static aeroelastic simulations are performed by the coupled viscous computational fluid dynamics with structural flexibility method in transonic and supersonic regimes. The developed coupling strategy including fluid–structure interpolation and volume mesh motion schemes is based on radial basis functions. Results are presented for a vertical and a horizontal grid fin mounted on a body. Horizontal fin results show that the deformed fin is swept backward and the axial force is increased. The deformations also induce the movement of center of pressure, causing the reduction and reversal in hinge moment for the transonic flow and the supersonic flow, respectively. For the vertical fin, the local effective incidences are increased due to the deformations so that the deformed normal force is greater than the original one. At high angles of attack, both the deformed and original normal forces experience a sudden reduction due to the interference of leeward separated vortices on the fin. Additionally, the increment in axial force is shown to correlate strongly with the increment in the square of normal force.

  6. The pelvic fin and girdle of Panderichthys and the origin of tetrapod locomotion.

    Science.gov (United States)

    Boisvert, Catherine A

    2005-12-22

    One of the most marked transformations in the vertebrate transition to land was that of fins to limbs. This transformation involved not only the generation of morphological novelties (digits, sacrum) but also a shift in locomotory dominance from the pectoral to the pelvic appendage. Despite its importance, the transformation from pelvic fin to hindlimb is the least studied and least well-documented part of this transformation, which is bracketed by the osteolepiform Eusthenopteron and the early tetrapods Ichthyostega and Acanthostega, but is not directly illuminated by any intermediate form. Panderichthys is the closest tetrapod relative currently represented by complete fossils, but its pelvic fin skeleton has not been described. Here, I present the only known articulated pelvic fin endoskeleton and associated partial pelvis of Panderichthys. The pelvic girdle is even less tetrapod-like than that of the osteolepiform Eusthenopteron, but the pelvic fin endoskeleton shares derived characteristics with basal tetrapods despite being more primitive than the pectoral fin of Panderichthys. The evolution of tetrapod locomotion appears to have passed through a stage of body-flexion propulsion, in which the pelvic fins played a relatively minor anchoring part, before the emergence of hindlimb-powered propulsion in the interval between Panderichthys and Acanthostega.

  7. Age estimation of burbot using pectoral fin rays, brachiostegal rays, and otoliths

    Science.gov (United States)

    Klein, Zachary B.; Terrazas, Marc M.; Quist, Michael C.

    2014-01-01

    Throughout much of its native distribution, burbot (Lota lota) is a species of conservation concern. Understanding dynamic rate functions is critical for the effective management of sensitive burbot populations, which necessitates accurate and precise age estimates. Managing sensitive burbot populations requires an accurate and precise non-lethal alternative. In an effort to identify a non-lethal ageing structure, we compared the precision of age estimates obtained from otoliths, pectoral fin rays, dorsal fin rays and branchiostegal rays from 208 burbot collected from the Green River drainage, Wyoming. Additionally, we compared the accuracy of age estimates from pectoral fin rays, dorsal fin rays and branchiostegal rays to those of otoliths. Dorsal fin rays were immediately deemed a poor ageing structure and removed from further analysis. Age-bias plots of consensus ages derived from branchiostegal rays and pectoral fin rays were appreciably different from those obtained from otoliths. Exact agreement between readers and reader confidence was highest for otoliths and lowest for branchiostegal rays. Age-bias plots indicated that age estimates obtained from branchiostegal rays and pectoral fin rays were substantially different from age estimates obtained from otoliths. Our results indicate that otoliths provide the most precise age estimates for burbot.

  8. Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus off Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Morteo

    2017-06-01

    Full Text Available Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus. In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n = 6, Gulf of California n = 6 and, Gulf of Mexico n = 7 were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p < 0.05 with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

  9. Assessment of in vitro antifungal activity of preparation ''fin Candimis'' against Candida strains

    Directory of Open Access Journals (Sweden)

    Anna Głowacka

    2013-12-01

    Full Text Available The aim of the study was to assess the antifungal activity of preparation „fin Candimis” (oregano essential oil against yeast-like strains belonging to the genus Candida. During the investigation, there were used up nine Candida albicans strains and ten C. glabrata strains isolated from different clinical material, along with one C. albicans demonstration strain ATCC 90028. The oregano essential oil, utilized in the study, was obtained from fresh leaves of Origanum vulgare L. and bore a trade name „fin Candimis”. According to data yielded by its manufacturer, concentration of pure oregano essential oil in preparation „fin Candimis” totals up to 210 mg/ml. The susceptibility of the Candida strains to preparation „fin Candimis” was assessed by means of the disc-diffusion method, upon the Sabouraud solid medium (after a 24-hour incubation of the cultures at temperature of 37 degrees centigrade; the oregano essential oil had been diluted in 1 ml of DMSO, according to the geometrical progression. A measure of the antifungal activity of preparation „fin Candimis” was the minimal inhibitory concentration (MIC, in terms of the fungus growth. Preparation „fin Candimis” is capable of being applied in the prevention and treatment of candidiasis – alone, or as a natural adjunctive agent. The C. albicans strains are more susceptible to preparation „fin Candimis” in comparison to the C. glabrata ones.

  10. CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan [Pusan National Univ., Busan (Korea, Republic of)

    2012-09-15

    Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number.

  11. Pectoral fin contact as a mechanism for social bonding among dolphins

    Science.gov (United States)

    Dudzinski, Kathleen; Ribic, Christine

    2017-01-01

    Bottlenose dolphins are large-brained social mammals residing in a fission-fusion society with relationships that are established and maintained over decades. We examined a decade-long data set of inter-individual pectoral fin contact exchanges to better understand how dolphins share information via tactile contact. Sex and age are significant factors in pectoral fin contact within non-kin dolphin dyads. Adult females shared more pectoral fin contacts with other adult females, while younger females showed no pattern of contact. Males shared more pectoral fin contacts with other males as juveniles and as adults, but showed no difference in the number of touches versus rubs as pectoral fin contacts with other males. Whether in the role of initiator as rubber or initiator as rubbee, male dolphins again preferred other males. These results support the notion that dolphins, especially male dolphins, might use pectoral fin contact as one tool in their repertoire for social bonding to establish, maintain and manage their inter-individual relationships. Additionally, it is also likely that the exchange of pectoral fin contact is developed and refined as individuals age, mature socially, and establish their place within a fission-fusion society.

  12. Fish's Muscles Distortion and Pectoral Fins Propulsion of Lift-Based Mode

    Science.gov (United States)

    Yang, S. B.; Han, X. Y.; Qiu, J.

    As a sort of MPF(median and/or paired fin propulsion), pectoral fins propulsion makes fish easier to maneuver than other propulsion, according to the well-established classification scheme proposed by Webb in 1984. Pectoral fins propulsion is classified into oscillatory propulsion, undulatory propulsion and compound propulsion. Pectoral fins oscillatory propulsion, is further ascribable to two modes: drag-based mode and lift-based mode. And fish exhibits strong cruise ability by using lift-based mode. Therefore to robot fish design using pectoral fins lift-based mode will bring a new revolution to resources exploration in blue sea. On the basis of the wave plate theory, a kinematic model of fish’s pectoral fins lift-based mode is established associated with the behaviors of cownose ray (Rhinoptera bonasus) in the present work. In view of the power of fish’s locomotion from muscle distortion, it would be helpful benefit to reveal the mechanism of fish’s locomotion variation dependent on muscles distortion. So this study puts forward the pattern of muscles distortion of pectoral fins according to the character of skeletons and muscles of cownose ray in morphology and simulates the kinematics of lift-based mode using nonlinear analysis software. In the symmetrical fluid field, the model is simulated left-right symmetrically or asymmetrically. The results qualitatively show how muscles distortion determines the performance of fish locomotion. Finally the efficient muscles distortion associated with the preliminary dynamics is induced.

  13. 印度尼西亚FinTech生态圈的发展及机遇%Development and Opportunities of FinTech Ecosystem in Indonesia

    Institute of Scientific and Technical Information of China (English)

    熊琦

    2018-01-01

    印尼FinTech是新兴行业,自2014年以来呈现井喷式增长,其生态圈竞争优势主要体现在需求方面:潜在市场巨大,资本投入增长迅猛,但人才优势尚显不足,政策上积极学习国际经验,已推出"监管沙盒"和针对P2P的严格管控法规,从长远看能促进FinTech包容性发展;印尼银行渗透率低,银行分支机构少,物理基础设施建设不足,且印尼人的FinTech意识较弱,中国FinTech企业在印尼的个人消贷和中小企业融资领域将大有作为;可加大对印尼的资金支持以帮助当地建设,更好地进行合作发展FinTech行业,实现共赢.

  14. Analysis of FinTech Innovation and Change%FinTech的创新与变革分析

    Institute of Scientific and Technical Information of China (English)

    韩梅

    2016-01-01

    Financial technology enterprises together with traditional financial institutions make a redefini⁃tion of modern finance, design a new business model, and reestablish the public trust in the financial services, in the process, FinTech has brought a series of financial service innovation and change:For example,get rid of medi⁃ation in loaning, revolution of paying, intelligent trade and financial change, which make the block chain (Block⁃chain) be paid attention to by all big financial institutions and technology enterprises. The biggest beneficiaries are customers, especially those small and medium-sized enterprises that have been discriminated by financial in⁃stitutions,has they have more options in capital and payment. We haveentereda new era in which thebanks seem more like science and technology companies, while science and technology companies are more like banks.%金融科技公司同传统金融机构一道在重新定义现代金融,设计新的商业模式,重新建立公众对金融服务的信任,在这一过程中,FinTech带来了金融服务的创新与系列的变革:例如,存贷去中介、支付革命、智能化交易与理财的变革,使区块链(Blockchain)受到各大金融机构与科技公司的格外关注。最大的受益者是客户,特别是那些一直受到金融机构歧视的中小企业,在资金获得和支付方面有了更多选择。我们已经步入一个银行更像科技公司,科技公司更像银行的新时代。

  15. Optimization analysis of convective–radiative longitudinal fins with temperature-dependent properties and different section shapes and materials

    International Nuclear Information System (INIS)

    Mosayebidorcheh, S.; Hatami, M.; Mosayebidorcheh, T.; Ganji, D.D.

    2015-01-01

    Graphical abstract: Temperature distribution along the fins obtained for different material and section shapes. - Highlights: • The steady state thermal analysis of longitudinal fins is presented. • The properties of fins are assumed as a function of temperature. • The rectangular, convex, triangular and concave profiles are considered for fin shape. • Least Square Method (LSM) is used for solving the governing equation. • Thermal optimization of fin geometry is presented based on maximum value of heat transfer. - Abstract: The main aim of this study is to obtain an optimum design point for fin geometry, so that heat transfer rate reaches to a maximum value in a constant fin volume. Effect of fin thicknesses ratio (τ), convection coefficient power index (m), profile power parameter (n), base thickness (δ) and fin material are evaluated in the fin optimization point for heat transfer rate, effectiveness and efficiency. It’s assumed that the thickness of longitudinal fins varies with length in a special profile, so four different shapes (rectangular, convex, triangular and concave) are considered. In present study, temperature-dependent heat generation, convection and radiation are considered and an analytical technique based on the least square method is proposed for the solution methodology. Results show that by increasing the fin thicknesses ratio, maximum heat transfer rate decreases and Copper among the other materials has the most heat transfer rate in a constant volume.

  16. Feasibility Study to Reduce Thermal Resistance of Finned Containment Wall in Simplified OPR1000

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Hwi; Kang, Hie Chan [Kunsan National University, Gunsan (Korea, Republic of); Noh, Hyung Gyun [Pohang University, Pohang (Korea, Republic of)

    2016-05-15

    This concept is securing of cooling capability by using finned containment itself, it could be another alternative for achieving decompression of containment as heat sink. The objective of this study is a feasibility test to estimate the heat transfer performance from the finned containment wall in case of OPR1000. The commercial code, ANSYS CFX 16 was used in this work. The number of grids is about 1.8 million. Therefore, 250mm rebar affects more considerable than that of 50mm to the temperature distribution. For this reasons, temperature distribution of z-axis direction was showed significant changes in (c). The heat transfer in three types of containment was 267.6W, 265.2W and 307.8W, respectively. The Type B case increased up to 15% of heat transfer than the baseline containment building. Three different types of containment wall were tested by numerical simulation to understand the cooling performance of finned containment wall. We can conclude as follows: For the finned containment wall type A that fins are installed inside and outside with the same rebar configuration of conventional containment building, the heat transfer is almost the same as conventional containment wall. The finned containment wall type B that volume fraction of rebar is increased transfer the heat 15% more compared with conventional one. The cross-sectional area or volume fraction of the rebar to attach fin is important to enhance the heat transfer. The fin efficiency of the fin is very low as 3.1% in the present cases.

  17. Performance ‘S’ Type Savonius Wind Turbine with Variation of Fin Addition on Blade

    Science.gov (United States)

    Pamungkas, S. F.; Wijayanto, D. S.; Saputro, H.; Widiastuti, I.

    2018-01-01

    Wind power has been receiving attention as the new energy resource in addressing the ecological problems of burning fossil fuels. Savonius wind rotor is a vertical axis wind turbines (VAWT) which has relatively simple structure and low operating speed. These characteristics make it suitable for areas with low average wind speed as in Indonesia. To identify the performance of Savonius rotor in generating electrical energy, this research experimentally studied the effect of fin addition for the ‘S’ shape of Savonius VAWT. The fin is added to fill the space in the blade in directing the wind flow. This rotor has two turbine blades, a rotor diameter of 1.1 m and rotor height of 1.4 m, used pulley transmission system with 1:4.2 multiplication ratio, and used a generator type PMG 200 W. The research was conducted during dry season by measuring the wind speed in the afternoon. The average wind speed in the area is 2.3 m/s with the maximum of 4.5 m/s. It was found that additional fin significantly increase the ability of Savonius rotor VAWT to generate electrical energy shown by increasing of electrical power. The highest power generated is 13.40 Watt at a wind speed of 4.5 m/s by adding 1 (one) fin in the blade. It increased by 22.71% from the rotor blade with no additional fin. However, increasing number of fins in the blade was not linearly increase the electrical power generated. The wind rotor blade with 4 additional fins is indicated has the lowest performance, generating only 10.80 Watt electrical power, accounted lower than the one generated by no fin-rotor blade. By knowing the effect of the rotor shape, the rotor dimension, the addition of fin, transmission, and generator used, it is possible to determine alternative geometry design in increasing the electrical power generated by Savonius wind turbine.

  18. Effect of fin-endwall fillet on thermal hydraulic performance of airfoil printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Ma, Ting; Xin, Fei; Li, Lei; Xu, Xiang-yang; Chen, Yi-tung; Wang, Qiu-wang

    2015-01-01

    Printed circuit heat exchanger (PCHE) is recommended to be used for intermediate heat exchanger in Very High Temperature Reactor (VHTR). One of the key features is that it is manufactured by the photochemical etching in order to maintain the internal structure and metal properties. In this paper, a photochemical etching experiment is conducted to manufacture the airfoil PCHE plate. The result indicates that the airfoil fin is not an ideal airfoil profile, but has a fin-endwall fillet. For the purpose of simplifying the numerical model and saving computational time, a validated model with a single fluid is used to further study the effect of fin-endwall fillet on the thermal hydraulic performance of airfoil PCHE. It is found that the fin-endwall fillet can increase the heat transfer and pressure drop in the cases with the non-dimensional longitudinal pitch being 1.63. The effect of fin-endwall fillet on thermal hydraulic performance decreases with the increase of transverse pitch, but the longitudinal pitch has little effect when the non-dimensional longitudinal pitch is greater than 1.88. In the studied cases, the maximum difference of Nusselt number and friction factor between the two models with and without fin-endwall fillet is up to 6.7% and 6.4%. - Highlights: • Fillets are formed in the endwall of airfoil fins during the photochemical etching. • Two-fluid model can be replaced by single-fluid model to perform simulation. • Fin-endwall fillet can increase heat transfer and pressure drop at ζ_l = 1.63. • Effect of fin-endwall fillet decreases as transverse pitch increases at ζ_l = 1.63. • Longitudinal pitch has little effect at ζ_l ≥ 1.88.

  19. Comparação entre a Feição de Hidrografia Extraída de uma Imagem do Srtm (Shuttle Radar Topography Mission) e a Vetorizada pelo Módulo Arcscan/ Arcgis®: : Estudo de Caso para Fins de Análise Hidrológica na Bacia Hidrográfica do Rio Grande, Divisa entre os Estados de MG e SP

    OpenAIRE

    Sady Júnior M. C. de Menezes; Thiago P. M. Soares; Vanessa Mendes Lana; Cleverson Alves de Lima; Fernando Soares de Oliveira; Claubert Wagner G. de Menezes; Carlos Antonio Alvares Soares Ribeiro; Vicente Paulo Soares

    2011-01-01

    O SRTM - Shutle Radar Topography Mission – é uma missão o qual gerou-se uma base topográfica digital de alta resolução. A SRTM consiste num sistema de radar especialmente modificado que voou a bordo do Endea-vour (ônibus espacial), em fevereiro de 2000. As imagens obtidas pelo SRTM garantiu amplas aplicações em estudos espaciais, uma vez que os processos de comunicação visual para a produção de cartografia de base e mapas de precisão da análise espacial foram utilizados. O present...

  20. Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

    International Nuclear Information System (INIS)

    Lan, H.-S.; Liu, C. W.

    2014-01-01

    The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Γ valley occupancy and enhances the injection velocity at virtual source node. (112 ¯ ) sidewall gives the highest current enhancement due to the rapidly increasing Γ valley occupancy. The non-parabolicity of the Γ valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Γ valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity

  1. Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lan, H.-S. [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Liu, C. W., E-mail: chee@cc.ee.ntu.edu.tw [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan (China)

    2014-05-12

    The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Γ valley occupancy and enhances the injection velocity at virtual source node. (112{sup ¯}) sidewall gives the highest current enhancement due to the rapidly increasing Γ valley occupancy. The non-parabolicity of the Γ valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Γ valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity.

  2. Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

    Directory of Open Access Journals (Sweden)

    Sanna Torma

    2004-01-01

    Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

  3. The FinTech phenomenon: antecedents of financial innovation perceived by the popular press

    OpenAIRE

    Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

    2016-01-01

    The financial industry has been strongly influenced by digitalization in the past few years reflected by the emergence of “FinTech,” which represents the marriage of “finance” and “information technology.” FinTech provides opportunities for the creation of new services and business models and poses challenges to traditional financial service providers. Therefore, FinTech has become a subject of debate among practitioners, investors, and researchers and is highly visible in the popular media. ...

  4. Investigation of defect-induced abnormal body current in fin field-effect-transistors

    International Nuclear Information System (INIS)

    Liu, Kuan-Ju; Tsai, Jyun-Yu; Lu, Ying-Hsin; Liu, Xi-Wen; Chang, Ting-Chang; Chen, Ching-En; Yang, Ren-Ya; Cheng, Osbert; Huang, Cheng-Tung

    2015-01-01

    This letter investigates the mechanism of abnormal body current at the linear region in n-channel high-k/metal gate stack fin field effect transistors. Unlike body current, which is generated by impact ionization at high drain voltages, abnormal body current was found to increase with decreasing drain voltages. Notably, the unusual body leakage only occurs in three-dimensional structure devices. Based on measurements under different operation conditions, the abnormal body current can be attributed to fin surface defect-induced leakage current, and the mechanism is electron tunneling to the fin via the defects, resulting in holes left at the body terminal

  5. Thermal-Hydraulic Performance of a Corrugated Cooling Fin with Louvered Surfaces

    DEFF Research Database (Denmark)

    Sønderby, Simon Kaltoft; Hosseini, Seyed Mojtaba Mir; Rezaniakolaei, Alireza

    2017-01-01

    The main objective of the article is to investigate thermal-hydraulic performance of a corrugated cooling fin with louvered surfaces. The investigation is carried out using the fin geometry of one most commonly used liquid-to-air heat exchangers. The investigation was carried out by numerically...... simulating the airflow with louvered fin geometry. The simulation model was verified by comparing simulated j- and f-factors with the corresponding values of several experimental correlations. The j-factors deviated less than 10.7 % from two of the experimental correlations, whereas deviations ranging...

  6. Classical Lie Point Symmetry Analysis of a Steady Nonlinear One-Dimensional Fin Problem

    Directory of Open Access Journals (Sweden)

    R. J. Moitsheki

    2012-01-01

    Full Text Available We consider the one-dimensional steady fin problem with the Dirichlet boundary condition at one end and the Neumann boundary condition at the other. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. We perform preliminary group classification to determine forms of the arbitrary functions appearing in the considered equation for which the principal Lie algebra is extended. Some invariant solutions are constructed. The effects of thermogeometric fin parameter and the exponent on temperature are studied. Also, the fin efficiency is analyzed.

  7. Thermal performance analysis of optimized hexagonal finned heat sinks in impinging air jet

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, Kenan, E-mail: kyakut@atauni.edu.tr [Department of Mechanical Engineering, Faculty of Engineering, Atatürk University, 25100, Erzurum (Turkey); Yeşildal, Faruk, E-mail: fayesildal@agri.edu.tr [Department of Mechanical Engineering, Faculty of Patnos Sultan Alparslan Natural Sciences and Engineering, Ağrı İbrahim Çeçen University, 04100, Ağrı (Turkey); Karabey, Altuğ, E-mail: akarabey@yyu.edu.tr [Department of Machinery and Metal Technology, Erciş Vocational High School, Yüzüncü Yıl University, 65400, Van (Turkey); Yakut, Rıdvan, E-mail: ryakut@kafkas.edu.tr [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Kafkas University, 36100, Kars (Turkey)

    2016-04-18

    In this study, thermal performance analysis of hexagonal finned heat sinks which optimized according to the experimental design and optimization method of Taguchi were investigated. Experiments of air jet impingement on heated hexagonal finned heat sinks were carried out adhering to the L{sub 18}(2{sup 1*}3{sup 6}) orthogonal array test plan. Optimum geometries were determined and named OH-1, OH-2. Enhancement efficiency with the first law of thermodynamics was analyzed for optimized heat sinks with 100, 150, 200 mm heights of hexagonal fin. Nusselt correlations were found out and variations of enhancement efficiency with Reynolds number presented in η–Re graphics.

  8. High temperature mechanical properties on multi stage blazed fin body with ultra fine off-set fin for compact heat exchanger

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro; Muto, Yasushi

    2003-01-01

    Three stage blazed plate fin body with ultra fine off-set fin (thickness x height x pitch x off-set pitch = 0.22 mm x 1.2 mm x 1.6 mm x 5 mm) for 600 MWt High Temperature Gas Cooled Reactor Gas Turbin (HTGR-GT) system was fabricated and tested on its high temperature mechanical properties and the following results were derived. (1) tested body shows almost the same strength an fatigue behavior of SUS 304 as main structural material at elevated temperatures up to 873 K, (2) static and fatigue fracture mainly occurred at ultra fine off-set and (3) high temperature strength and fatigue life are improved by blazing technique to double side walls of the fin by Ni blaze material. (author)

  9. Understanding Fish Linear Acceleration Using an Undulatory Biorobotic Model with Soft Fluidic Elastomer Actuated Morphing Median Fins.

    Science.gov (United States)

    Wen, Li; Ren, Ziyu; Di Santo, Valentina; Hu, Kainan; Yuan, Tao; Wang, Tianmiao; Lauder, George V

    2018-04-10

    Although linear accelerations are an important common component of the diversity of fish locomotor behaviors, acceleration is one of the least-understood aspects of propulsion. Analysis of acceleration behavior in fishes with both spiny and soft-rayed median fins demonstrates that fin area is actively modulated when fish accelerate. We implemented an undulatory biomimetic robotic fish model with median fins manufactured using multimaterial three-dimensional printing-a spiny-rayed dorsal fin, soft-rayed dorsal/anal fins, and a caudal fin-whose stiffnesses span three orders of magnitude. We used an array of fluidic elastomeric soft actuators to mimic the dorsal/anal inclinator and erector/depressor muscles of fish, which allowed the soft fins to be erected or folded within 0.3 s. We experimentally show that the biomimetic soft dorsal/anal fin can withstand external loading. We found that erecting the soft dorsal/anal fins significantly enhanced the linear acceleration rate, up to 32.5% over the folded fin state. Surprisingly, even though the projected area of the body (in the lateral plane) increased 16.9% when the median fins were erected, the magnitude of the side force oscillation decreased by 24.8%, which may have led to significantly less side-to-side sway in the robotic swimmer. Visualization of fluid flow in the wake of median fins reveals that during linear acceleration, the soft dorsal fin generates a wake flow opposite in direction to that of the caudal fin, which creates propulsive jets with time-variant circulations and jet angles. Erectable/foldable fins provide a new design space for bioinspired underwater robots with structures that morph to adapt to different locomotor behaviors. This biorobotic fish model is also a potentially promising system for studying the dynamics of complex multifin fish swimming behaviors, including linear acceleration, steady swimming, and burst and coast, which are difficult to analyze in freely swimming fishes.

  10. MODELO PARA LA CREACIÓN DEL CONOCIMIENTO PARA PYMES

    Directory of Open Access Journals (Sweden)

    Marino Valencia Rodríguez

    2009-01-01

    Full Text Available La creciente importancia del conocimiento, como nuevo factor de producción, hace que la creación y transferencia se convierta en una de las principales prioridades de las organizaciones. El presente artículo describe tanto los fundamentos de la teoría de los recursos y capacidades de la empresa como el enfoque de la gestión del conocimiento, con sus procesos de generación y transferencia del conocimiento. Estos sirven de guía básica teórica para alcanzar el siguiente objetivo: Diseñar un modelo de generación y transferencia de conocimiento para los procesos de dirección, gestión humana y del conocimiento para PyMES, con el fin de que éstas alcancen mayores niveles de competitividad. El modelo se diseña, a partir del direccionamiento estratégico de la organización. Está conformado por tres etapas, articuladas con elementos y actividades. Las acciones se enfocan en dos factores clave de éxito: la cultura organizacional y la formación. La utilización del modelo permitirá a las PyMES optimizar los recursos y capacidades disponibles, lo cual se refleja en el desempeño del trabajador y en el fortalecimiento de la cultura organizacional.

  11. para su puesta en marcha

    Directory of Open Access Journals (Sweden)

    Sergio Franco Maass

    2004-01-01

    Full Text Available Los sistemas de información geográfica (SIG tienen una gran aplicación en la gestión municipal; permiten cumplir con dos objetivos fundamentales: el registro de información territorial y el análisis de problemas territoriales específicos. Con el fin de determinar la viabilidad de este tipo de tecnologías en el ámbito municipal, se enfrentó el problema de la localización de instalaciones para la disposición final de residuos sólidos urbanos en el municipio de Toluca, Estado de México. Se identifican ciertos aspectos que limitan la práctica de los SIG: la diversidad entre los municipios, los problemas administrativos, las deficiencias de la información y la carencia de recursos humanos, técnicos y financieros.

  12. Experimental study of flow friction characteristics of integral pin-fin tubes

    International Nuclear Information System (INIS)

    Ding Ming; Yan Changqi; Sun Licheng

    2007-01-01

    Friction characteristics of integral pin-fin tubes, through which lubricating-oil flowed vertically, were studied experimentally. Effects of the pitch, the height of fins and the machining direction on friction coefficient were analyzed. The experimental results showed that the friction coefficient of the integral pin-fro tube was obviously lager than that of smooth tube. Compared with other influential factors, the effect of the height of fins was dominant. Because the three-dimensional pin fin could disturb and destroy the boundary layer, when the Reynolds Number reached 200-300, the friction coefficient curve began to bend, that was, a turning point was appeared in the friction coefficient curve. (authors)

  13. Optimum design of vaporizer fin with liquefied natural gas by numerical analysis

    International Nuclear Information System (INIS)

    Jeong, Hyo Min; Chung, Han Shik; Lee, Sang Chul; Kong, Tae Woo; Yi, Chung Seub

    2006-01-01

    Generally, the temperature drop under 0 .deg. C on vaporizer surface creates frozen dews. This problem seems to increase as the time progress and humidity rises. In addition, the frozen dews create frost deposition. Consequently, heat transfer on vaporizer decreases because frost deposition causes adiabatic condition. Therefore, it is very important to solve this problem. This paper aims to study of the optimum design of used vaporizer at local LNG station. In this paper, experimental results were compared with numerical results. Geometries of numerical and experimental vaporizers were identical. Studied parameters of vaporizer are angle between two fins (Φ) and fin thickness (TH F ). Numerical analysis results were presented through the correlations between the ice layer thickness (TH ICE ) on the vaporizer surface to the temperature distribution of inside vaporizer (T IN ), fin thickness (TH F ), and angle between two fins (Φ). Numerical result shows good agreement with experimental outcome. Finally, the correlations for optimum design of vaporizer are proposed on this paper

  14. DNR 100K Lakes - Fishing in the Neighborhood (FiN) Ponds

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer represents ponds included in DNR's Fishing in the Neighborhood (FiN) program. This program establishes local ponds to provide urban fishing opportunities...

  15. Multi-Mode Electric Actuator Dynamic Modelling for Missile Fin Control

    Directory of Open Access Journals (Sweden)

    Bhimashankar Gurav

    2017-06-01

    Full Text Available Linear first/second order fin direct current (DC actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviour.

  16. A Numerical Study on Heat Transfer and Flow Characteristics of a Finned Downhole Coaxial Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chun Dong; Lee, Dong Hyun; Park, Byung-Sik; Choi, Jaejoon [Korea Institute of Energy Research (KIER), Daejeon (Korea, Republic of)

    2017-02-15

    In this study, the flow and heat transfer characteristics of the finned annular passage were investigated numerically. The annular passage simulates co-axial geothermal heat exchanger, and fins are installed on its inner wall to reduce heat loss from the production passage (annulus) to injection passage (inner pipe). A commercial CFD program, Ansys Fluent, was used with SST k-ω turbulence model. The effects of the geometric parameters of the fin on the inner tube were analyzed under the periodic boundary condition. The result indicated that most parameters had a tendency to increase with an increase in the height and angle of the fin. However, it was confirmed that the Nusselt number of the inner tube on the coaxial 15, 5, 0.3 was lower than that of the smooth tube. Additionally, the Nusselt number of the inner tube exhibited a tendency of decreasing with a decrease in the spacing in Coaxial 15, S{sub f}, 0.3.

  17. Control characteristics for wrap-around fins on cruise missiles configurations

    Science.gov (United States)

    Sawyer, W. C.; Monta, W. J.; Carter, W. V.; Alexander, W. K.

    1981-01-01

    This paper presents selected results of a panel loads study conducted as part of the final phase of an extensive investigation of an air-breathing missile concept employing wrap-around aerodynamic surfaces. Typical results for M = 2.36 are presented for the fin load results, plus a brief review of basic results of the previously reported tests. Vapor screen results are also discussed. The present results indicate that the fin load characteristics are nearly identical for planar and curved fins having the same projected planform and would permit the use of planar-surface predictions for supersonic speeds in the preliminary design stages of missiles employing wrap-around curved fins.

  18. Study on heat and mass transfer characteristics of humid air-flow in a fin bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hwi [Air-Conditioner Research Laboratory, LG Electronics, Seoul 153-082 (Korea); Koyama, Shigeru; Kuwahara, Ken [Department of Energy and Environmental Engineering, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Kwon, Jeong-Tae [Department of Mechanical Engineering, Hoseo University, Asan, Chungnam 336-795 (Korea); Park, Byung-Duck [School of Mechanical and Automotive Engineering, Kyungpook National University, Sangju, Gyeongbuk 742-711 (Korea)

    2010-11-15

    This paper deals with the heat and mass transfer characteristics of humid air-flow under frosting conditions. A slit fin bundle was used for the simulation of fins of a heat exchanger. The effects of the cooling block temperature, air humidity and air velocity on the frosting characteristics were experimentally investigated. The frosted mass was affected considerably by the cooling block temperature and air humidity. However, the effect of air velocity on it was not so large. The pressure drop was affected remarkably by all experimental parameters in this study. Local heat flux distribution and frost thickness distribution on each fin were predicted from the measured fin temperatures and the mass and energy conservation equations on the frost surface and inside the frost layer. (author)

  19. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

    Directory of Open Access Journals (Sweden)

    Foued Chabane

    2014-03-01

    Full Text Available The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

  20. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater.

    Science.gov (United States)

    Chabane, Foued; Moummi, Noureddine; Benramache, Said

    2014-03-01

    The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s(-1). Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s(-1) with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

  1. The use of hand paddles and fins in front crawl: biomechanical and physiological responses

    Directory of Open Access Journals (Sweden)

    Cristiano Cardoso de Matos

    2013-04-01

    Full Text Available Paddles and fins are used during swim training and practice as tools for improving performance. The use of these equipment can alter physiological and kinematic parameters of swimming. The purpose of this literature review was to present and discussthe effects of paddles and fins on kinematic and physiological variables in front crawl,and provide update on the topic for teachers, researchers, coaches and swimmers. Thirty articles were reviewed. To crawl, paddles can change the averages of stroke length and stroke rate, the average swimming speed, the absolute duration of the stroke phases and the index of coordination. Fins can modify the average stroke rate, the average swimming speed, the kick frequency and deep, and the energy cost. We found no studies that verified the longitudinal effects of the use of paddles and fins on these parameters.

  2. Longline Observer (HI & Am. Samoa) Opah Fin Clip Collection for Lampris spp. Distribution Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set containing information collected from the 1000+ fin clips collected by Hawaii & American Samoa Longline Observers that will be used to analyze the...

  3. Thermal analysis of annular fins with temperature-dependent thermal properties

    Institute of Scientific and Technical Information of China (English)

    I. G. AKSOY

    2013-01-01

    The thermal analysis of the annular rectangular profile fins with variable thermal properties is investigated by using the homotopy analysis method (HAM). The thermal conductivity and heat transfer coefficient are assumed to vary with a linear and power-law function of temperature, respectively. The effects of the thermal-geometric fin parameter and the thermal conductivity parameter variations on the temperature distribution and fin efficiency are investigated for different heat transfer modes. Results from the HAM are compared with numerical results of the finite difference method (FDM). It can be seen that the variation of dimensionless parameters has a significant effect on the temperature distribution and fin efficiency.

  4. Computational Fluid Dynamic (CFD) Analysis of a Generic Missile With Grid Fins

    National Research Council Canada - National Science Library

    DeSpirito, James

    2000-01-01

    This report presents the results of a study demonstrating an approach for using viscous computational fluid dynamic simulations to calculate the flow field and aerodynamic coefficients for a missile with grid fin...

  5. FinTech的发展现状与金融创新分析

    Institute of Scientific and Technical Information of China (English)

    韩梅

    2016-01-01

    FinTech借助于大数据和科技创新的双重驱动,使得过去无法实现的金融服务如数据反欺诈、智能投顾、快速交易验证等成为现实。 FinTech同传统金融机构一道在重新定义现代金融、设计新的商业模式,给金融行业带来了众多的变革,从零售、支付和转账、财富管理、交易经纪、保险乃至监管都在被FinTech强力改变。 FinTech将很快取代互联网金融,进入主流市场。

  6. Experimental research on single phase convection heat transfer in micro-fin tube

    International Nuclear Information System (INIS)

    Fan Guangming; Sun Zhongning; Zhu Sheng

    2011-01-01

    An experimental investigation of heat transfer and flow resistance characteristics of single phase water in three micro-fin tubes with different fin height was conducted. At the same time, the efficiency of micro-fin tubes within the experimental scope was evaluated and the optimal working region was determined. Based on the experimental data in the optimal working region, correlations for predicting the heat transfer and flow resistance were also given by multiple regression method. The result indicates that the micro-fin tubes can greatly enhance the single-phase heat transfer in turbulent flow, and the increase of heat transfer coefficient is higher than the increase of flow resistance. The accuracy of the correlation is very high, of which the deviation from the experimental value is very small. (authors)

  7. Experimental research of inclined-micro-fin flat tube on single phase convection heat transfer

    International Nuclear Information System (INIS)

    Fan Guangming; Sun Zhongning; Wang Meng

    2011-01-01

    The experimental research of heat transfer and flow resistance characteristics of single phase water in four inclined-micro-fin flat tubes with different physical dimensions was conducted. At the same time,suitable criteria were selected to evaluate the efficiency of inclined-micro-fin flat tubes within the experimental scope and the optimal working region was determined. The results indicate that inclined-micro-fin flat tubes can greatly enhance the single-phase heat transfer in turbulent flow and the maximum heat transfer coefficient attains to 5.9 times of that in smooth tube. The quantities of heat transfer for inclined-micro-fin flat tubes are three times higher than that of smooth tube with the same of heat exchange area and pump power. (authors)

  8. Role of fin material and nanofluid in performance enhancement of automobile radiator

    Science.gov (United States)

    Jadar, Raju; Shashishekar, K. S.; Channa Keshava Naik, N.

    2018-04-01

    An effective cooling system can avoid engine and its components from overheating and helps in achieving optimum engine performance. This work deals with the fabrication and performance evaluation of an automobile radiator with i) Aluminum fins and ii) Al-MWCNT fins using 0.1 w/v% f-MWCNT nanofluid. F-MWCNT nanoparticles in the base fluid improves the rate of heat transfer in an automobile radiator integrated with Al-MWCNT fins. The enhancement of heat transfer mainly depends on the quantity of F-MWCNT nanoparticles added to the host fluid. During the study it was found that at a low weight by volume concentration of nanofluid the heat transfer enhancement of 8% was achieved using Al-MWCNT fins compared to base fluid.

  9. Analysis of Turbulence Models in a Cross Flow Pin Fin Micro-Heat Exchanger

    National Research Council Canada - National Science Library

    Lind, Eric

    2002-01-01

    ... of their physical significance to the complex flow environment of a pin fin, cross flow, micro-heat exchanger. Applications of this research include cooling of turbine blades and of closely spaced electronics.

  10. Thermal-hydraulic performance of the finned surface of a compact heat exchanger

    International Nuclear Information System (INIS)

    Errasti Cabrera, Michel

    2015-01-01

    In this work the thermal-hydraulic behavior of the finned surface of a compact heat exchanger is obtained in tube-fin configuration corrugated (wavy). Through numerical simulation are determined average values ​​of intensification of heat transfer and pressure loss in the inter-channel finned. The objective is to characterize the surface to use as a reference, to make comparisons with other heat exchange surfaces enhanced using traditional techniques combined with more current, such as vortex generators. The study is conducted in laminar flow, with Reynolds numbers below 1000. In the working model compact exchanger tubes and corrugated fins (wavy) heat is described, and the results of the coefficient of overall heat transfer and the pressure drop are explained from the local characteristics of the velocity field and temperature inside the heat exchanger. (Full text)

  11. Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

    International Nuclear Information System (INIS)

    Wang Zhenlong; Hang Guanrong; Wang Yangwei; Li Jian; Du Wei

    2008-01-01

    An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s −1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s −1 and 22° s −1 , respectively

  12. Out-of-plane strain effect on silicon-based flexible FinFETs

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-06-21

    Summary form only given. We report out-of-plane strain effect on silicon based flexible FinFET, with sub 20 nm wide fins and hafnium silicate based high-κ gate dielectric. Since ultra-thin inorganic solid state substrates become flexible with reduced thickness, flexing induced strain does not enhance performance. However, detrimental effects arise as the devices are subject to various out-of-plane stresses (compressive and tensile) along the channel length.

  13. Fin efficiency in 2D with convection at the tip and dissymmetry of exchange

    International Nuclear Information System (INIS)

    Bouaziz, Najib

    2009-01-01

    To determine the overall effective surface in the heat exchangers, it is necessary to know the fin efficiency accurately. An analytical formula, taking into account the convective heat at the tip and an unequal exchange in 2D case is derived. Some differences were found between 1D and our expression. The dissymmetry of exchange has a strong effect on the fin efficiency and convection at the tip cannot be ignored.

  14. Out-of-plane strain effect on silicon-based flexible FinFETs

    KAUST Repository

    Ghoneim, Mohamed T.; Alfaraj, Nasir; Sevilla, Galo T.; Fahad, Hossain M.; Hussain, Muhammad Mustafa

    2015-01-01

    Summary form only given. We report out-of-plane strain effect on silicon based flexible FinFET, with sub 20 nm wide fins and hafnium silicate based high-κ gate dielectric. Since ultra-thin inorganic solid state substrates become flexible with reduced thickness, flexing induced strain does not enhance performance. However, detrimental effects arise as the devices are subject to various out-of-plane stresses (compressive and tensile) along the channel length.

  15. Origin of fin-clipped salmonids collected at two thermal discharges on Lake Michigan

    International Nuclear Information System (INIS)

    Romberg, G.P.; Thommes, M.M.; Spigarelli, S.A.

    1974-01-01

    Fin clips observed on fish collected during tagging studies at the Point Beach and Waukegan thermal discharges were recorded and the data were tabulated by species. Using fin clip and fish size, attempts were made to identify probable stocking locations and dates from agency records. Data are presented for lake trout, rainbow trout, brown trout, and Coho salmon. Tables are presented to show probable stocking locations and dates

  16. Finned tube heat exchangers. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The bibliography contains citations concerning theoretical studies and applications of finned tubing in a variety of heat exchanger design configurations. The effects of turbulent and laminar flow are presented in terms of heat transfer for both external and internal finned surfaces. Energy conservation and waste heat recovery systems are featured and the use of refrigerants is also included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. The heartstrings mutation in zebrafish causes heart/fin Tbx5 deficiency syndrome.

    Science.gov (United States)

    Garrity, Deborah M; Childs, Sarah; Fishman, Mark C

    2002-10-01

    Holt-Oram syndrome is one of the autosomal dominant human "heart-hand" disorders, with a combination of upper limb malformations and cardiac defects. Holt-Oram syndrome is caused by mutations in the TBX5 gene, a member of a large family of T-box transcription factors that play important roles in cell-type specification and morphogenesis. In a screen for mutations affecting zebrafish cardiac function, we isolated the recessive lethal mutant heartstrings, which lacks pectoral fins and exhibits severe cardiac dysfunction, beginning with a slow heart rate and progressing to a stretched, non-functional heart. We mapped and cloned the heartstrings mutation and find it to encode the zebrafish ortholog of the TBX5 gene. The heartstrings mutation causes premature termination at amino acid 316. Homozygous mutant embryos never develop pectoral fin buds and do not express several markers of early fin differentiation. The total absence of any fin bud differentiation distinguishes heartstrings from most other mutations that affect zebrafish fin development, suggesting that Tbx5 functions very early in the pectoral fin induction pathway. Moderate reduction of Tbx5 by morpholino causes fin malformations, revealing an additional early requirement for Tbx5 in coordinating the axes of fin outgrowth. The heart of heartstrings mutant embryos appears to form and function normally through the early heart tube stage, manifesting only a slight bradycardia compared with wild-type siblings. However, the heart fails to loop and then progressively deteriorates, a process affecting the ventricle as well as the atrium. Relative to mammals, fish require lower levels of Tbx5 to produce malformed appendages and display whole-heart rather than atrial-predominant cardiac defects. However, the syndromic deficiencies of tbx5 mutation are remarkably well retained between fish and mammals.

  18. Swimming performance of a bio-inspired robotic vessel with undulating fin propulsion.

    Science.gov (United States)

    Liu, Hanlin; Curet, Oscar M

    2018-06-18

    Undulatory fin propulsion exhibits high degree of maneuver control -- an ideal for underwater vessels exploring complex environments. In this work, we developed and tested a self-contained, free-swimming robot with a single undulating fin running along the length of the robot, which controls both forward motion and directional maneuvers. We successfully replicated several maneuvers including forward swimming, reversed motion, diving, station-keeping and vertical swimming. For each maneuver, a series of experiments were performed as a function of fin frequency, wavelength and traveling wave direction to measure swimming velocities, orientation angles and mean power consumption. In addition, three-dimensional flow fields were measured during forward swimming and station-keeping using volumetric particle image velocimetry (PIV). The efficiency for forward swimming was compared using three metrics: cost of transport, wave efficiency and Strouhal number. The results indicate that the cost of transport exhibits a V-shape trend with the minimum value at low swimming velocity. The robot can reach optimal wave efficiency and locomotor performance at a range of 0.2 to 0.4 St. Volumetric PIV data reveal the shed of vortex tubes generated by the fin during forward swimming and station keeping. For forward swimming, a series of vortex tubes are shed off the fin edge with a lateral and downward direction with respect to the longitudinal axis of the fin. For station keeping, flow measurements suggest that the vortex tubes are shed at the mid-section of the fin while the posterior and anterior segment of the vortex stay attached to the fin. These results agree with the previous vortex structures based on simulations and 2D PIV. The further development of this vessel with high maneuverability and station keeping performance can be used for oceanography, coastal exploration, defense, oil industry and other marine industries where operations are unsafe or impractical for divers or

  19. FinFET centric variability-aware compact model extraction and generation technology supporting DTCO

    OpenAIRE

    Wang, Xingsheng; Cheng, Binjie; Reid, David; Pender, Andrew; Asenov, Plamen; Millar, Campbell; Asenov, Asen

    2015-01-01

    In this paper, we present a FinFET-focused variability-aware compact model (CM) extraction and generation technology supporting design-technology co-optimization. The 14-nm CMOS technology generation silicon on insulator FinFETs are used as testbed transistors to illustrate our approach. The TCAD simulations include a long-range process-induced variability using a design of experiment approach and short-range purely statistical variability (mismatch). The CM extraction supports a hierarchical...

  20. Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance

    Science.gov (United States)

    Pech-Canul, M. A.; Guía-Tello, J. C.; Pech-Canul, M. I.; Aguilar, J. C.; Gorocica-Díaz, J. A.; Arana-Guillén, R.; Puch-Bleis, J.

    An aluminum automotive condenser was designed to exhibit high corrosion resistance in the seawater acetic acid test (SWAAT) combining zinc coated microchannel tubes and fins made with AA4343/AA3003(Zn)/AA4343 brazing sheet. Electrochemical measurements in SWAAT solution were carried out under laboratory conditions using tube-fin assembly and individual fin and tube samples withdrawn from the condenser core. The aim was to gain information on the protective role of the zinc sacrificial layer and about changes in corrosion behavior as a function of immersion time. External corrosion of the tube-fin system was simulated by immersion of mini-core samples under open circuit conditions. The corrosion rate increased rapidly during the first 6 h and slowly afterwards. The short time behavior was related to the dissolution of the oxide film and fast dissolution of the outermost part of the zinc diffusion layer. With the aid of cross-sectional depth corrosion potential profiles, it was shown that as the sacrificial layer gets dissolved, the surface concentration of zinc decreases and the potential shifts to less negative values. The results of galvanic coupling of tube and fins in a mini-cell showed that the tube became the anode while the fins exhibited cathodic behavior. An evolution in the galvanic interaction was observed, due to the progressive dissolution of the sacrificial zinc layer. The difference of uncoupled potentials between tube and fins decreased from 71 mV to 32 mV after 84 h of galvanic coupling. At the end of such period there was still a part of the zinc sacrificial layer remaining which would serve for protection of the tube material for even longer periods and there were indications of slight corrosion in the fins.

  1. Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance

    Directory of Open Access Journals (Sweden)

    M.A. Pech-Canul

    Full Text Available An aluminum automotive condenser was designed to exhibit high corrosion resistance in the seawater acetic acid test (SWAAT combining zinc coated microchannel tubes and fins made with AA4343/AA3003(Zn/AA4343 brazing sheet. Electrochemical measurements in SWAAT solution were carried out under laboratory conditions using tube-fin assembly and individual fin and tube samples withdrawn from the condenser core. The aim was to gain information on the protective role of the zinc sacrificial layer and about changes in corrosion behavior as a function of immersion time. External corrosion of the tube-fin system was simulated by immersion of mini-core samples under open circuit conditions. The corrosion rate increased rapidly during the first 6 h and slowly afterwards. The short time behavior was related to the dissolution of the oxide film and fast dissolution of the outermost part of the zinc diffusion layer. With the aid of cross-sectional depth corrosion potential profiles, it was shown that as the sacrificial layer gets dissolved, the surface concentration of zinc decreases and the potential shifts to less negative values. The results of galvanic coupling of tube and fins in a mini-cell showed that the tube became the anode while the fins exhibited cathodic behavior. An evolution in the galvanic interaction was observed, due to the progressive dissolution of the sacrificial zinc layer. The difference of uncoupled potentials between tube and fins decreased from 71 mV to 32 mV after 84 h of galvanic coupling. At the end of such period there was still a part of the zinc sacrificial layer remaining which would serve for protection of the tube material for even longer periods and there were indications of slight corrosion in the fins. Keywords: Aluminum, Automotive, Corrosion, Galvanic, Zn coating

  2. FIN5 positively regulates far-red light responses in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Cho, D.S.; Hong, S.H.; Nam, H.G.; Soh, M.S.

    2003-01-01

    We report the characterization of a semi-dominant mutation fin5-1 (far-red insensitive 5-1) of Arabidopsis, which was isolated from genetic screening of phytochrome A (phyA) signaling components. Plants with the fin5-1 mutation exhibited a long hypocotyl phenotype when grown under far-red (FR) light, but not under red light. Physiological analyses implied that FIN5 might be differentially involved in diverse responses that are regulated by phyA under continuous FR light. Anthocyanin accumulation, gravitropic response of hypocotyl growth, and FR light-preconditioned blocking of greening were also impaired in the fin5-1 mutant, whereas photoperiodic floral induction was not, if at all, significantly affected. Moreover, light-regulated expression of the CHS, PORA and PsbS genes was attenuated in fin5-1 mutant plants, while the light-induced expression of CAB was normal. The mutation exhibited semi-dominance regarding control of hypocotyl growth in FR light. We suggest that FIN5 defines a novel branch in the network of phyA signaling in Arabidopsis. (author)

  3. A novel mini-DNA barcoding assay to identify processed fins from internationally protected shark species.

    Science.gov (United States)

    Fields, Andrew T; Abercrombie, Debra L; Eng, Rowena; Feldheim, Kevin; Chapman, Demian D

    2015-01-01

    There is a growing need to identify shark products in trade, in part due to the recent listing of five commercially important species on the Appendices of the Convention on International Trade in Endangered Species (CITES; porbeagle, Lamna nasus, oceanic whitetip, Carcharhinus longimanus scalloped hammerhead, Sphyrna lewini, smooth hammerhead, S. zygaena and great hammerhead S. mokarran) in addition to three species listed in the early part of this century (whale, Rhincodon typus, basking, Cetorhinus maximus, and white, Carcharodon carcharias). Shark fins are traded internationally to supply the Asian dried seafood market, in which they are used to make the luxury dish shark fin soup. Shark fins usually enter international trade with their skin still intact and can be identified using morphological characters or standard DNA-barcoding approaches. Once they reach Asia and are traded in this region the skin is removed and they are treated with chemicals that eliminate many key diagnostic characters and degrade their DNA ("processed fins"). Here, we present a validated mini-barcode assay based on partial sequences of the cytochrome oxidase I gene that can reliably identify the processed fins of seven of the eight CITES listed shark species. We also demonstrate that the assay can even frequently identify the species or genus of origin of shark fin soup (31 out of 50 samples).

  4. Resolution of ray-finned fish phylogeny and timing of diversification.

    Science.gov (United States)

    Near, Thomas J; Eytan, Ron I; Dornburg, Alex; Kuhn, Kristen L; Moore, Jon A; Davis, Matthew P; Wainwright, Peter C; Friedman, Matt; Smith, W Leo

    2012-08-21

    Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the "bush at the top of the tree" that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the "Second Age of Fishes."

  5. Numerical Study of Compact Plate-Fin Heat Exchanger for Rotary-Vane Gas Refrigeration Machine

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2017-10-01

    Full Text Available Plate-fin heat exchangers are widely used in refrigeration technique. They are popular because of their compactness and excellent heat transfer performance. Here we present a numerical model for the development, research and optimization of a plate-fin heat exchanger for a rotary-vane gas refrigeration machine. The method of analysis by graphic method of plate - fin heat exchanger is proposed. The model describes the effects of secondary parameters such as axial thermal conductivity through a metal matrix of the heat exchanger. The influence of geometric parameters and heat transfer coefficient is studied. Graphs of dependences of length, efficiency of a fin and pressure drop in a heat exchanger on the thickness of the fin and the number of fins per meter are obtained. To analyze the results of numerical simulation, the heat exchanger was designed in the Aspen HYSYS program. The simulation results show that the total deviation from the proposed numerical model is not more than 15%. 

  6. Indirect adaptive output feedback control of a biorobotic AUV using pectoral-like mechanical fins

    International Nuclear Information System (INIS)

    Naik, Mugdha S; Singh, Sahjendra N; Mittal, Rajat

    2009-01-01

    This paper treats the question of servoregulation of autonomous underwater vehicles (AUVs) in the yaw plane using pectoral-like mechanical fins. The fins attached to the vehicle have oscillatory swaying and yawing motion. The bias angle of the angular motion of the fin is used for the purpose of control. Of course, the design approach considered here is applicable to AUVs for other choices of oscillation patterns of the fins, which produce periodic forces and moments. It is assumed that the vehicle parameters, hydrodynamic coefficients, as well the fin forces and moments are unknown. For the trajectory control of the yaw angle, a sampled-data indirect adaptive control system using output (yaw angle) feedback is derived. The control system has a modular structure, which includes a parameter identifier and a stabilizer. For the control law derivation, an internal model of the exosignals (reference signal (constant or ramp) and constant disturbance) is included. Unlike the direct adaptive control scheme, the derived control law is applicable to minimum as well as nonminimum phase biorobotic AUVs (BAUVs). This is important, because for most of the fin locations on the vehicle, the model is a nonminimum phase. In the closed-loop system, the yaw angle trajectory tracking error converges to zero and the remaining state variables remain bounded. Simulation results are presented which show that the derived modular control system accomplishes precise set point yaw angle control and turning maneuvers in spite of the uncertainties in the system parameters using only yaw angle feedback

  7. A novel mini-DNA barcoding assay to identify processed fins from internationally protected shark species.

    Directory of Open Access Journals (Sweden)

    Andrew T Fields

    Full Text Available There is a growing need to identify shark products in trade, in part due to the recent listing of five commercially important species on the Appendices of the Convention on International Trade in Endangered Species (CITES; porbeagle, Lamna nasus, oceanic whitetip, Carcharhinus longimanus scalloped hammerhead, Sphyrna lewini, smooth hammerhead, S. zygaena and great hammerhead S. mokarran in addition to three species listed in the early part of this century (whale, Rhincodon typus, basking, Cetorhinus maximus, and white, Carcharodon carcharias. Shark fins are traded internationally to supply the Asian dried seafood market, in which they are used to make the luxury dish shark fin soup. Shark fins usually enter international trade with their skin still intact and can be identified using morphological characters or standard DNA-barcoding approaches. Once they reach Asia and are traded in this region the skin is removed and they are treated with chemicals that eliminate many key diagnostic characters and degrade their DNA ("processed fins". Here, we present a validated mini-barcode assay based on partial sequences of the cytochrome oxidase I gene that can reliably identify the processed fins of seven of the eight CITES listed shark species. We also demonstrate that the assay can even frequently identify the species or genus of origin of shark fin soup (31 out of 50 samples.

  8. Line-edge roughness induced single event transient variation in SOI FinFETs

    International Nuclear Information System (INIS)

    Wu Weikang; An Xia; Jiang Xiaobo; Chen Yehua; Liu Jingjing; Zhang Xing; Huang Ru

    2015-01-01

    The impact of process induced variation on the response of SOI FinFET to heavy ion irradiation is studied through 3-D TCAD simulation for the first time. When FinFET biased at OFF state configuration (V gs = 0, V ds = V dd ) is struck by a heavy ion, the drain collects ionizing charges under the electric field and a current pulse (single event transient, SET) is consequently formed. The results reveal that with the presence of line-edge roughness (LER), which is one of the major variation sources in nano-scale FinFETs, the device-to-device variation in terms of SET is observed. In this study, three types of LER are considered: type A has symmetric fin edges, type B has irrelevant fin edges and type C has parallel fin edges. The results show that type A devices have the largest SET variation while type C devices have the smallest variation. Further, the impact of the two main LER parameters, correlation length and root mean square amplitude, on SET variation is discussed as well. The results indicate that variation may be a concern in radiation effects with the down scaling of feature size. (paper)

  9. Impact of line edge roughness on the performance of 14-nm FinFET: Device-circuit Co-design

    Science.gov (United States)

    Rathore, Rituraj Singh; Rana, Ashwani K.

    2018-01-01

    With the evolution of sub-20 nm FinFET technology, line edge roughness (LER) has been identified as a critical problem and may result in critical device parameter variation and performance limitation in the future VLSI circuit application. In the present work, an analytical model of fin-LER has been presented, which shows the impact of correlated and uncorrelated LER on FinFET structure. Further, the influence of correlated and uncorrelated fin- LER on all electrical performance parameters is thoroughly investigated using the three-dimensional (3-D) Technology Computer Aided Design (TCAD) simulations for 14-nm technology node. Moreover, the impact of all possible fin shapes on threshold voltage (VTH), drain induced barrier lowering (DIBL), on-current (ION), and off-current (IOFF) has been compared with the well calibrated rectangular FinFET structure. In addition, the influence of all possible fin geometries on the read stability of six-transistor (6-T) Static-Random-Access-Memory (SRAM) has been investigated. The study reveals that fin-LER plays a vital role as it directly governs the electrostatics of the FinFET structure. This has been found that there is a high degree of fluctuations in all performance parameters for uncorrelated fin-LER type FinFETs as compared to correlated fin-LER with respect to rectangular FinFET structure. This paper gives physical insight of FinFET design, especially in sub-20 nm technology nodes by concluding that the impact of LER on electrical parameters are minimum for correlated LER.

  10. Parametric study of propeller boss cap fins for container ships

    Science.gov (United States)

    Lim, Sang-Seop; Kim, Tae-Won; Lee, Dong-Myung; Kang, Chung-Gil; Kim, Soo-Young

    2014-06-01

    The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed

  11. Desarrollo de un plan de marketing digital para una aplicación móvil basada en planes de ocio

    OpenAIRE

    Silva Padilla, Sergio

    2017-01-01

    En este documento se definirá un Plan de Marketing Digital para una idea de negocio presentada en el proyecto de fin de carrera de la ETSIT UPM por Leonor Barrueco en 2015. Dicho proyecto documentaba un plan de negocio para una aplicación móvil basada en planes de ocio llamada LOCALING , pero dejaba pendiente, para una etapa posterior, la definición con más detalle del plan de marketing digital, que es precisamente lo que se desarrollará en el presente Proyecto de Fin de Carrera. Este P...

  12. Modelo de capacidad de pago para categorizar usuarios de servicios públicos de agua y saneamiento básico

    OpenAIRE

    Betancur Londoño, David

    2012-01-01

    El presente documento es una recopilación teórica y un contraste estadístico para evaluar la estratificación socioeconómica en términos del concepto de capacidad de pago, y en el contexto de los servicios públicos de agua y saneamiento básico. Para tal fin, se realiza una descripción detallada de los componentes económicos circunscritos a este tipo de servicio público, con el fin de lograr una aproximación conceptual que permita determinar un posible valor económico para el mismo. Asimismo, d...

  13. Comercialización e importación al mercado colombiano de productos de iluminación LED para interiores

    OpenAIRE

    Restrepo Cortés, Oscar Eduardo

    2017-01-01

    Este trabajo presenta un plan de negocios para una compañía que importa y comercializa al mercado colombiano productos de iluminación LED para interiores, con el fin de exponer las áreas que se consideran más importantes para este plan y abarcando de manera concreta y objetiva su desarrollo -- Por lo tanto, se busca lograr un avance objetivo del proyecto, con el fin de que la propuesta de valor tenga la mayor similitud posible entre lo planeado y lo ejecutado -- Por medio de la investigación ...

  14. Consejos para los adolescentes latinos que adoptan ambas culturas (Tips for Latino teens)

    Centers for Disease Control (CDC) Podcasts

    Podcast para los adolescentes latinos: Este podcast ofrece consejos útiles a los adolescentes latinos sobre cómo encontrar un equilibrio entre su cultura de origen y la cultura estadounidense, con el fin de disfrutar de una vida más feliz y saludable.

  15. Herramienta web para el aprendizaje autónomo o guiado de instrumentos musicales

    OpenAIRE

    Moreno Rodríguez, Beatriz

    2015-01-01

    El proyecto desarrollado en este trabajo fin de máster consiste en un sitio web pensado para aquellas personas que desean aprender a tocar algún instrumento musical a través de internet, tanto si se prefiere un aprendizaje dirigido como libre.

  16. Performance and cost benefits analysis of double-pass solar collector with and without fins

    International Nuclear Information System (INIS)

    Fudholi, Ahmad; Sopian, Kamaruzzaman; Ruslan, Mohd Hafidz; Othman, Mohd Yusof

    2013-01-01

    Highlights: • The thermal performances and cost analysis of the double-pass solar collector with and without fins absorber were discussed. • The theoretical and experimental study on the double-pass solar air collector with and without fins absorber was conducted. • The ratio of AC/AEG or the cost benefit ratio was presented. • The double-pass solar collector with fins absorber is more cost-effective compared to without fins absorber. - Abstract: The performance and cost benefit analysis of double-pass solar collector with and without fins have been conducted. The theoretical model using steady state analysis has been developed and compared with the experimental results. The performance curves of the double-pass solar collector with and without fins, which included the effects of mass flow rate and solar intensity on the thermal efficiency of the solar collector, were obtained. Results indicated that the thermal efficiency is proportional to the solar intensity at a specific mass flow rate. The thermal efficiency increased by 9% at a solar intensity of 425–790 W/m 2 and mass flow rate of 0.09 kg/s. The theoretical and experimental analysis showed a similar trend as well as close agreement. Moreover, a cost-effectiveness model has been developed examine the cost benefit ratio of double-pass solar collector with and without fins. Evaluation of the annual cost (AC) and the annual energy gain (AEG) of the collector were also performed. The results show that the double-pass solar collector with fins is more cost-effective compared to the double-pass solar collector without fins for mass flow rate of 0.01–0.07 kg/s. Also, simulations were obtained for the double-pass solar collector with fins at Nusselt number of 5.42–36.21. The energy efficiency of collector increases with the increase of Nusselt number. The results show that by increasing the Nusselt number simultaneously would drop the outlet temperature at any solar intensity. Increase in Nusselt number

  17. Optimization methodology for large scale fin geometry on the steel containment of a Public Acceptable Simple SMR (PASS)

    International Nuclear Information System (INIS)

    Kim, Do Yun; NO, Hee Cheon; Kim, Ho Sik

    2015-01-01

    Highlights: • Optimization methodology for fin geometry on the steel containment is established. • Optimum spacing is 7 cm in PASS containment. • Optimum thickness is 0.9–1.8 cm when a fin height is 10–25 cm. • Optimal fin geometry is determined in given fin height by overall effectiveness correlation. • 13% of material volume and 43% of containment volume are reduced by using fins. - Abstracts: Heat removal capability through a steel containment is important in accident situations to preserve the integrity of a nuclear power plant which adopts a steel containment concept. A heat transfer rate will be enhanced by using fins on the external surface of the steel containment. The fins, however, cause to increase flow resistance and to deteriorate the heat transfer rate at the same time. Therefore, this study investigates an optimization methodology of large scale fin geometry for a vertical base where a natural convection flow regime is turbulent. Rectangular plate fins adopted in the steel containment of a Public Acceptable Simple SMR (PASS) is used as a reference. The heat transfer rate through the fins is obtained from CFD tools. In order to optimize fin geometry, an overall effectiveness concept is introduced as a fin performance parameter. The optimizing procedure is starting from finding optimum spacing. Then, optimum thickness is calculated and finally optimal fin geometry is suggested. Scale analysis is conducted to show the existence of an optimum spacing which turns out to be 7 cm in case of PASS. Optimum thickness is obtained by the overall effectiveness correlation, which is derived from a total heat transfer coefficient correlation. The total heat transfer coefficient correlation of a vertical fin array is suggested considering both of natural convection and radiation. However, the optimum thickness is changed as a fin height varies. Therefore, optimal fin geometry is obtained as a function of a fin height. With the assumption that the heat

  18. Agency theory in a nonprofit organization Teoria de agência em uma organização sem fins lucrativos

    Directory of Open Access Journals (Sweden)

    Ivan Luiz Ecco

    2010-10-01

    Full Text Available The aim of this paper is to analyze, based on the agency theory, the existence of agency conflicts in management by results in a professional education nonprofit organization. For the program, the case study method was used in a nonprofit professional education organization, located in the state of Santa Catarina. The study examined the contract between the Headquarters of the Organization (which represents in this study, according to theory of agency, the principal and its School Units (representing, the agents to accomplish goals. The results show that the asymmetry of information and organizational culture are factors that contribute to the problem of agency and the determination of an optimal contract should take into consideration such situations. The main conclusion is that agency problems are also present in nonprofit organizations, even when an instrument for the management by results is implemented.O objetivo deste artigo é analisar, à luz da teoria da agência, a existência de conflitos de agência, em uma gestão por resultados, de uma organização educacional sem fins lucrativos. Para sua realização utilizou-se o método de estudo de caso em uma organização de educação profissional sem fins lucrativos, situada no Estado de Santa Catarina. O estudo analisou o contrato celebrado entre a Sede da Organização (que representa neste estudo, segundo a teoria da agência, o principal e suas Unidades Escolares (consideradas os agentes para o cumprimento de metas. Os resultados demonstram que a assimetria de informação e a cultura organizacional são fatores quecontribuem para que o problema de agência ocorra e a determinação de um contrato ótimo deveria levar em consideração tais situações. A principal conclusão é de que os problemas de agência também estão presentes nas organizações sem fins lucrativos, mesmo quando se implanta um instrumento para realizar a gestão por resultados.

  19. Análisis geotécnico de anclas planas para plataformas marinas

    OpenAIRE

    Arto Cuesta, Javier

    2017-01-01

    RESUMEN: El presente Trabajo de Fin de Grado es un estudio englobado en el campo de la geotecnia offshore sobre el comportamiento de anclas planas para aerogeneradores dispuestas en suelos puramente cohesivos (arcilla) y puramente friccionales (arena). Para elaborar el análisis, se ha realizado un modelado numérico, mediante un software comercial basado en el empleo de elementos finitos, de un ancla plana dispuesta a diferentes profundidades, sobre la cual se aplica un desplazamien...

  20. Cumulative effects of using pin fin heat sink and porous metal foam on thermal management of lithium-ion batteries

    International Nuclear Information System (INIS)

    Mohammadian, Shahabeddin K.; Zhang, Yuwen

    2017-01-01

    Highlights: • 3D transient thermal analysis of a pouch Li-ion cell has been carried out. • Using pin fin heat sink improves the temperature reduction at low pumping powers. • Using pin fin heat sink enhances the temperature uniformity at low air flow rates. • Porous aluminum foam insertion with pin fins improves temperature reduction. • Porous aluminum foam insertion with pin fins enhances temperature uniformity. - Abstract: Three-dimensional transient thermal analysis of an air-cooled module was carried out to investigate cumulative effects of using pin fin heat sink and porous metal foam on thermal management of a Li-ion (lithium-ion) battery pack. Five different cases were designed as Case 1: flow channel without any pin fin or porous metal foam insertion, Case 2: flow channel with aluminum pin fins, Case 3: flow channel with porous aluminum foam pin fins, Case 4: fully inserted flow channel with porous aluminum foam, and Case 5: fully inserted flow channel with porous aluminum foam and aluminum pin fins. The effects of porous aluminum insertions, pin fin types, air flow inlet temperature, and air flow inlet velocity on the temperature uniformity and maximum temperature inside the battery pack were systematically investigated. The results showed that using pin fin heat sink (Case 2) is appropriate only for low air flow velocities. In addition, the use of porous aluminum pin fins or embedding porous aluminum foam inside the air flow channel (Cases 3 and 4) are not beneficial for thermal management improvement. The combination of aluminum pin fins and porous aluminum foam insertion inside the air flow channel (Case 5) is a proper option that improves both temperature reduction and temperature uniformity inside the battery cell.

  1. Anatomy and muscle activity of the dorsal fins in bamboo sharks and spiny dogfish during turning maneuvers.

    Science.gov (United States)

    Maia, Anabela; Wilga, Cheryl D

    2013-11-01

    Stability and procured instability characterize two opposing types of swimming, steady and maneuvering, respectively. Fins can be used to manipulate flow to adjust stability during swimming maneuvers either actively using muscle control or passively by structural control. The function of the dorsal fins during turning maneuvering in two shark species with different swimming modes is investigated here using musculoskeletal anatomy and muscle function. White-spotted bamboo sharks are a benthic species that inhabits complex reef habitats and thus have high requirements for maneuverability. Spiny dogfish occupy a variety of coastal and continental shelf habitats and spend relatively more time cruising in open water. These species differ in dorsal fin morphology and fin position along the body. Bamboo sharks have a larger second dorsal fin area and proportionally more muscle insertion into both dorsal fins. The basal and radial pterygiophores are plate-like structures in spiny dogfish and are nearly indistinguishable from one another. In contrast, bamboo sharks lack basal pterygiophores, while the radial pterygiophores form two rows of elongated rectangular elements that articulate with one another. The dorsal fin muscles are composed of a large muscle mass that extends over the ceratotrichia overlying the radials in spiny dogfish. However, in bamboo sharks, the muscle mass is divided into multiple distinct muscles that insert onto the ceratotrichia. During turning maneuvers, the dorsal fin muscles are active in both species with no differences in onset between fin sides. Spiny dogfish have longer burst durations on the outer fin side, which is consistent with opposing resistance to the medium. In bamboo sharks, bilateral activation of the dorsal in muscles could also be stiffening the fin throughout the turn. Thus, dogfish sharks passively stiffen the dorsal fin structurally and functionally, while bamboo sharks have more flexible dorsal fins, which result from a

  2. Colombia: la guerra irregular en el fin de siglo

    Directory of Open Access Journals (Sweden)

    Alfredo RANGEL SUÁREZ

    2009-11-01

    Full Text Available RESUMEN: El artículo analiza las transformaciones de la guerra irregular de las guerrillas colombianas en las últimas décadas. Para ello, se estudian los cambios que han afectado a distintos factores, como los objetivos estratégicos, los medios financieros, militares, las relaciones que mantienen con los partidos políticos tradicionales en el nivel local, sus parámetros ideológicos, el origen social de sus miembros. Con esta perspectiva, se analiza el cálculo político/temporal que la guerrilla hace en la actual coyuntura y sus consecuencias para el proceso de paz.ABSTRACT: This article examines the transformations of the irregular war of the colombian guerrillas, studying the changes of several factors such as the strategic goals, the financial and army resources, the relationship among the political parties in the local level, the evolution of their ideological parameters and of the social origin of their members. With this perspectiva, the author analyses temporal and political calculation that the guerrilla makes at this point, and its consequences for the peace process.

  3. Conceptos de diseño para manufactura (DFM de piezas microfundidas

    Directory of Open Access Journals (Sweden)

    Carlos Julio Cortés Rodríguez

    2005-09-01

    Full Text Available Una de las metodologIas utilizadas por la ingenierIa concurrente o diseno integrado de productos es el diseno para manufactura, DEM. Esta técnica, que está orientada a melorar la fabricación de piezas analizando geometrIas, valores y tolerancias, es utilizada en las primeras etapas de diseno para disminuir los costos de los elementos a fabricar. Se estudió el diseno para manufactura estableciendo reglas de diseno a fin de elaborar una metodologIa para diseno en microfundición.

  4. Differentiation of chondrocytes and scleroblasts during dorsal fin skeletogenesis in flounder larvae.

    Science.gov (United States)

    Suzuki, Tohru; Haga, Yutaka; Takeuchi, Toshio; Uji, Susumu; Hashimoto, Hisashi; Kurokawa, Tadahide

    2003-01-01

    In teleosts, the embryonic fin fold consists of a peridermis, an underlying epidermis and a small number of mesenchymal cells. Beginning from such a simple structure, the fin skeletons, including the proximal and distal radials and lepidotrichia (finrays), develop in the dorsal fin fold at the larval stage. Their process of skeletogenesis and embryonic origin are unclear. Using flounder larvae, we report the differentiation process for chondrocytes and scleroblasts prior to fin skeletogenesis and the effects of retinoic acid (RA) on it. In early larvae, the mesenchymal cells grow between the epidermis and spinal cord to form a line of periodical condensations, which are proximal radial primordia, to produce chondrocytes. The prescleroblasts, which ossify the proximal radial cartilages, differentiate in the mesenchymal cells remaining between the cartilages. Then, mesenchymal condensations occur between the distal ends of the proximal radials, forming distal radial primordia, to produce chondrocytes. Simultaneously, condensations occur between the distal radial primordia and peridermis, which are lepidotrichia primordia, to produce prescleroblasts. Exogenous RA specifically inhibits the mesenchymal condensation prior to the proximal radial formation together with the down-regulation of sonic hedgehog (shh) and patched (pta) expression, resulting in the loss of proximal radials. Thus, it was indicated that differentiation of the precursor cells of radials and lepidotrichia begins in the proximal part of the fin fold and that the initial mesenchymal condensation prior to the proximal radial formation is highly susceptible to the effects of RA. Lepidotrichia formation does not occur where proximal radials are absent, indicating that lepidotrichia differentiation requires interaction with the radial cartilages. To examine the suggestion that neural crest cells contribute to the medial fin skeletons, we localized the HNK-1 positive cells in flounder embryos and slug and

  5. The impact of internal longitudinal fins in parabolic trough collectors operating with gases

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Tzivanidis, Christos; Daniil, Ilias; Antonopoulos, Kimon A.

    2017-01-01

    Highlights: • In this study, the impact of internal fins in PTC operating with gases is presented. • Air, helium and CO_2 are tested in smooth absorber and with fins of 5–10 mm and 15 mm. • Greater fin length leads to higher thermal efficiency and 10 mm is the optimum length exergetically. • Helium is the best working fluid exergetically, with CO_2 and air to follow. • Up to 290 °C, helium performs better energetically, while CO_2 in higher temperatures. - Abstract: In this study, the use of internal fins in parabolic trough collectors operating with gas working fluids is examined. Air, helium and carbon dioxide are the investigated working fluids, while Eurotrough ET-150 is the examined solar collector. The design and the simulation of this solar collector are performed with the commercial software Solidworks Flow Simulation. The internal fins lead to higher thermal efficiency but also to higher pressure losses; something very important for the solar fields of Concentrated Power Plants. Thus, the collector is examined energetically and exergetically in order to take into account the increase in the useful output with the simultaneous greater need of pumping power. Various fin lengths are examined and finally the fin of 10 mm was proved to be the most appropriate exergetically. In working fluid comparison, helium is the most efficient working fluid exergetically for all the examined cases. In the thermal efficiency comparison, helium performs better up to 290 °C, while carbon dioxide is the best choice in higher temperature levels. Moreover, the optimum mass flow rate for the helium was proved to be 0.03 kg/s and for the other working fluids the value of 0.015 kg/s seems to lead to the most satisfying results.

  6. Optimization design of LED heat dissipation structure based on strip fins

    Science.gov (United States)

    Xue, Lingyun; Wan, Wenbin; Chen, Qingguang; Rao, Huanle; Xu, Ping

    2018-03-01

    To solve the heat dissipation problem of LED, a radiator structure based on strip fins is designed and the method to optimize the structure parameters of strip fins is proposed in this paper. The combination of RBF neural networks and particle swarm optimization (PSO) algorithm is used for modeling and optimization respectively. During the experiment, the 150 datasets of LED junction temperature when structure parameters of number of strip fins, length, width and height of the fins have different values are obtained by ANSYS software. Then RBF neural network is applied to build the non-linear regression model and the parameters optimization of structure based on particle swarm optimization algorithm is performed with this model. The experimental results show that the lowest LED junction temperature reaches 43.88 degrees when the number of hidden layer nodes in RBF neural network is 10, the two learning factors in particle swarm optimization algorithm are 0.5, 0.5 respectively, the inertia factor is 1 and the maximum number of iterations is 100, and now the number of fins is 64, the distribution structure is 8*8, and the length, width and height of fins are 4.3mm, 4.48mm and 55.3mm respectively. To compare the modeling and optimization results, LED junction temperature at the optimized structure parameters was simulated and the result is 43.592°C which approximately equals to the optimal result. Compared with the ordinary plate-fin-type radiator structure whose temperature is 56.38°C, the structure greatly enhances heat dissipation performance of the structure.

  7. Relationships of mercury concentrations across tissue types, muscle regions and fins for two shark species

    KAUST Repository

    O'Bryhim, Jason R.

    2017-01-31

    Mercury (Hg) exposure poses a threat to both fish and human health. Sharks are known to bioaccumulate Hg, however, little is known regarding how Hg is distributed between different tissue groups (e.g. muscle regions, organs). Here we evaluated total mercury (THg) concentrations from eight muscle regions, four fins (first dorsal, left and right pectorals, caudal-from both the inner core and trailing margin of each fin), and five internal organs (liver, kidney, spleen, heart, epigonal organ) from two different shark species, bonnethead (Sphyrna tiburo) and silky shark (Carcharhinus falciformis) to determine the relationships of THg concentrations between and within tissue groups. Total Hg concentrations were highest in the eight muscle regions with no significant differences in THg concentrations between the different muscle regions and muscle types (red and white). Results from tissue collected from any muscle region would be representative of all muscle sample locations. Total Hg concentrations were lowest in samples taken from the fin inner core of the first dorsal, pectoral, and caudal (lower lobe) fins. Mercury concentrations for samples taken from the trailing margin of the dorsal, pectoral, and caudal fins (upper and lower lobe) were also not significantly different from each other for both species. Significant relationships were found between THg concentrations in dorsal axial muscle tissue and the fin inner core, liver, kidney, spleen and heart for both species as well as the THg concentrations between the dorsal fin trailing margin and the heart for the silky shark and all other sampled tissue types for the bonnethead shark. Our results suggest that biopsy sampling of dorsal muscle can provide data that can effectively estimate THg concentrations in specific organs without using more invasive, or lethal methods.

  8. Annual Acoustic Presence of Fin Whale (Balaenoptera physalus) Offshore Eastern Sicily, Central Mediterranean Sea

    Science.gov (United States)

    Sciacca, Virginia; Caruso, Francesco; Beranzoli, Laura; Chierici, Francesco; De Domenico, Emilio; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Simeone, Francesco; Viola, Salvatore; Riccobene, Giorgio

    2015-01-01

    In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus) in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea), throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, “NEMO-SN1”, deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO) Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz–1 kHz, sampling rate: 2 kHz) which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9–22.5 Hz) was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise. PMID:26581104

  9. Plan de comunicación para Barriobar

    OpenAIRE

    Pardo Castillo, Iris

    2016-01-01

    Treball de Final de Grau en Publicitat i Relacions Públiques. Codi: PU0932. Curs acadèmic 2015-2016 Este proyecto es un Trabajo Fin de Grado de la titulación Publicidad y Relaciones Públicas. Se trata de un trabajo de modalidad C que consiste en la elaboración de un Plan de Comunicación íntegro para una empresa. En este caso, para la franquicia de restauración BarrioBar. BarrioBar es una empresa que nació y se expandió a través de Valencia y sus pueblos fronterizos. Con gran...

  10. TIC para enseñar y jugar al ajedrez

    OpenAIRE

    Fernández Amigo, Joaquín; Pallarés Porcar, Maria Rosario

    2009-01-01

    Del año 1990 al 2002 en el CEIP Pompeu Fabra de Parets del Vallès (Barcelona) realizamos una serie de actividades alrededor del ajedrez ya que consideramos que es un extraordinario medio para fomentar en nuestro alumnado aspectos cognitivos, de personalidad, sociabilidad y un sin fin de valores. A lo largo de esta colaboración, incidiremos en los recursos informáticos (programas) y portales de Internet que hemos utilizado para ayudar a implementar el ajedrez en nuestra escuela.

  11. Herramientas CASE para ingeniería de Requisitos

    Directory of Open Access Journals (Sweden)

    Andrea Alarcon

    2008-10-01

    Full Text Available En este artículo se presentan apartes del resultado de la investigación sobre algunas herramientas CASE que apoyan las tareas de la Ingeniería de Requisitos (IR. Dicha fase esta contemplada en el proceso de Ingenieríade Software para el desarrollo de proyectos informáticos. Además se pretende analizar, sistematizar e integrarlos resultados del estudio con el fin de determinarlas principales características, ventajas y desventajas de una herramienta CASE para la IR.

  12. Comparação entre a Feição de Hidrografia Extraída de uma Imagem do Srtm (Shuttle Radar Topography Mission e a Vetorizada pelo Módulo Arcscan/ Arcgis®: : Estudo de Caso para Fins de Análise Hidrológica na Bacia Hidrográfica do Rio Grande, Divisa entre os Estados de MG e SP

    Directory of Open Access Journals (Sweden)

    Sady Júnior M. C. de Menezes

    2011-08-01

    Full Text Available O SRTM - Shutle Radar Topography Mission – é uma missão o qual gerou-se uma base topográfica digital de alta resolução. A SRTM consiste num sistema de radar especialmente modificado que voou a bordo do Endea-vour (ônibus espacial, em fevereiro de 2000. As imagens obtidas pelo SRTM garantiu amplas aplicações em estudos espaciais, uma vez que os processos de comunicação visual para a produção de cartografia de base e mapas de precisão da análise espacial foram utilizados. O presente estudo foi baseado em duas etapas de processamento de dados: inicialmente, incidiu sobre a manipulação de bases vetorizadas (dados de hidrografia obtidos pelo IBGE - Instituto Brasileiro de Geografia e Estatística e, em seguida, gerou-se informações vetorizadas a partir de imagens SRTM. A área de estudo é a Bacia do Rio Grande, MG/SP. Usando o programa de Sistemas de Informação Geográfica - ArcGIS 9.3.1 - foi obtido pelo módulo Spatial Analyst a hidrografia que foi extraída do SRTM. Após essa extração, foram comparadas as informações obtidas com o IBGE (vetor da base de dados utilizando o módulo Arcscan/ArcGIS e as informações obtidas pelo SRTM. Verificou-se uma ligeira diferença entre a distribuição e a concentração dos prováveis canais de drenagem entre os mapas dos vetores gerados (IBGE x SRTM. O trabalho demonstrou o uso dos dados do SRTM possibilitando a atualização de dados da rede hidrográfica de extensas áreas de modo bastante facilitado, com a vantagem de ser organizado pela mesma equipe e pelo mesmo processo metodológico, sem riscos de desigualdades durante sua geração.

  13. An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

    International Nuclear Information System (INIS)

    Palmre, Viljar; Pugal, David; Kim, Sungjun; Kim, Kwang J; Hubbard, Joel J; Fleming, Maxwell; Leang, Kam K

    2013-01-01

    This paper discusses the design, fabrication, and characterization of an ionic polymer–metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s −1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure

  14. An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

    Science.gov (United States)

    Palmre, Viljar; Hubbard, Joel J.; Fleming, Maxwell; Pugal, David; Kim, Sungjun; Kim, Kwang J.; Leang, Kam K.

    2013-01-01

    This paper discusses the design, fabrication, and characterization of an ionic polymer-metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s-1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure. These

  15. Influence of the degree of thermal contact in fin and tube heat exchanger

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

    2016-01-01

    Present work aims to investigate the significance of thermal contact area between fins and tubes in a heat exchanger. The heat exchanger type selected for the study is a liquid-gas fin and tube heat exchanger. Four different cases namely I, II, III, and IV, based on a variable degree of thermal...... contact between fins and tubes are investigated. Case-I with 100% thermal contact area between the fin and tube is set as a reference to cases-II, III, and IV with a thermal contact area of approximately 70%, 50%, and 35%, respectively. Three-dimensional (3D) steady-state numerical models based on finite...... and to compare the performance of heat exchanger design in different cases. Comparative analysis indicates a significant influence of the degree of the thermal contact area between fin and tube on the overall performance. Case-I is found to have higher overall heat transfer coefficient of 47.332 W/(m2 K), higher...

  16. Development of structural design procedure of plate-fin heat exchanger for HTGR

    Energy Technology Data Exchange (ETDEWEB)

    Mizokami, Yorikata, E-mail: yorikata_mizokami@mhi.co.jp [Mitsubishi Heavy Industries, Ltd., 1-1, Wadasaki-cho 1-Chome, Hyogo-ku, Kobe 652-8585 (Japan); Igari, Toshihide [Mitsubishi Heavy Industries, Ltd., 5-717-1, Fukahori-machi, Nagasaki 851-0392 (Japan); Kawashima, Fumiko [Kumamoto University, 39-1 Kurokami 2-Chome, Kumamoto 860-8555 (Japan); Sakakibara, Noriyuki [Mitsubishi Heavy Industries, Ltd., 5-717-1, Fukahori-machi, Nagasaki 851-0392 (Japan); Tanihira, Masanori [Mitsubishi Heavy Industries, Ltd., 16-5, Konan 2-Chome, Minato-ku, Tokyo 108-8215 (Japan); Yuhara, Tetsuo [The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Hiroe, Tetsuyuki [Kumamoto University, 39-1 Kurokami 2-Chome, Kumamoto 860-8555 (Japan)

    2013-02-15

    Highlights: ► We propose high temperature structural design procedure for plate-fin heat exchanger ► Allowable stresses for brazed structures will be newly discussed ► Validity of design procedure is confirmed by carrying out partial model tests ► Proposed design procedure is applied to heat exchangers for HTGR. -- Abstract: Highly efficient plate-fin heat exchanger for application to HTGR has been focused on recently. Since this heat exchanger is fabricated by brazing a lot of plates and fins, a new procedure for structural design of brazed structures in the HTGR temperature region up to 950 °C is required. Firstly in this paper influences on material strength due to both thermal aging during brazing process and helium gas environment were experimentally examined, and failure mode and failure limit of brazed side-bar structures were experimentally clarified. Secondly allowable stresses for aging materials and brazed structures were newly determined on the basis of the experimental results. For the purpose of validating the structural design procedure including homogenization FEM modeling, a pressure burst test and a thermal fatigue test of partial model for plate-fin heat exchanger were carried out. Finally, results of reference design of plate-fin heat exchangers of recuperator and intermediate heat exchanger for HTGR plant were evaluated by the proposed design criteria.

  17. Studi Eksperimental Vertical Axis Wind Turbine Tipe Savonius dengan Variasi Jumlah Fin pada Sudu

    Directory of Open Access Journals (Sweden)

    Ola Dwi Sandra Hasan

    2013-09-01

    Full Text Available Salah satu  teknologi sistem konversi energi angin  yang ada adalah turbin Savonius yang merupakan salah satu jenis Vertical Axis Wind Turbine ( VAWT . Turbin Savonius  memiliki  karakteristik strating torsi yang baik, mudah dalam pembutannya dan dapat menerima angin dari segala arah namun kekurangan yang dimiliki adalah coefficient of power (Cp turbin yang rendah. Untuk itu banyak dilakukan penelitian untuk meningkatkan efisiensi dari turbin Savonius. Salah satunya adalah penambahan end plate yang mampu meningkatkan perbedaan tekanan dari kedua sisi sudu sehingga memperbesar drag positif turbin. Untuk itu pada penelitian ini dilakukan variasi jumlah penambahan fin pada sudu. Variasi jumlah fin yang dilakukan adalah 1,2,4 dan 7 fin serta pengujian dengan menggunakan generator dan tanpa generator. Dari hasil pengujian, variasi fin yang dapat meningkatkan Cp turbin Savonius adalah variasi 1 fin jika dibandingkan  turbin standarnya dengan nilai Cp sebesar 0,11.  SKEA turbin Savonius menggunakan generator 12 V;400W dapat  menghasilkan daya maksimal 5,71 Watt pada putaran 134 rpm

  18. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    International Nuclear Information System (INIS)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K.

    2016-01-01

    Mixed convection flow in enclosures has been a subject of interest for many years due to their ever increasing applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. In comparison, little effort has been given to the problem of mixed convection in enclosures filled with nanofluids, while the addition of nanoparticles in a fluid base to alter specific material properties is considered a feasible solution for many heat transfer problems. Mixed convection of nanofluids is a challenging problem as the addition of nanoparticles changes the fluid’s thermo-physical properties as well as due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, a two-dimensional steady-state numerical model has been developed to investigate mixed convection flow of nanofluids in a square enclosure with an intruded rectangular fin and to optimize the fin geometry for maximizing the heat transfer using the Constructal design. The model has been developed using ANSYS-FLUENT for various fin geometries. Flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers for several geometries of the fin with the aim of maximizing the heat transfer from the fin to the surrounding flow. Outcome of this study provides important insight into the heat transfer behavior of nanofluids, which will help in developing novel geometries with enhanced and controlled heat transfer for solar collectors and electronic devices.

  19. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K., E-mail: prodip.das@ncl.ac.uk [School of Mechanical and Systems Engineering Newcastle University Newcastle upon Tyne, NE1 7RU United Kingdom (United Kingdom)

    2016-07-12

    Mixed convection flow in enclosures has been a subject of interest for many years due to their ever increasing applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. In comparison, little effort has been given to the problem of mixed convection in enclosures filled with nanofluids, while the addition of nanoparticles in a fluid base to alter specific material properties is considered a feasible solution for many heat transfer problems. Mixed convection of nanofluids is a challenging problem as the addition of nanoparticles changes the fluid’s thermo-physical properties as well as due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, a two-dimensional steady-state numerical model has been developed to investigate mixed convection flow of nanofluids in a square enclosure with an intruded rectangular fin and to optimize the fin geometry for maximizing the heat transfer using the Constructal design. The model has been developed using ANSYS-FLUENT for various fin geometries. Flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers for several geometries of the fin with the aim of maximizing the heat transfer from the fin to the surrounding flow. Outcome of this study provides important insight into the heat transfer behavior of nanofluids, which will help in developing novel geometries with enhanced and controlled heat transfer for solar collectors and electronic devices.

  20. A comparison of pectoral fin contact between two different wild dolphin populations

    Science.gov (United States)

    Dudzinski, K.M.; Gregg, J.D.; Ribic, C.A.; Kuczaj, S.A.

    2009-01-01

    Contact behaviour involving the pectoral fin has been documented in a number of dolphin species, and various explanations about its function have been offered. Pectoral fin contact can take a variety of forms, and involves a number of body parts and movements, likely differing depending upon social or ecological context. For this study, we compare the pectoral fin contact behaviour of two species of wild dolphins: Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan, and Atlantic spotted dolphins (Stenella frontalis) from The Bahamas. The two study populations exhibit surprising similarity in the ways in which pectoral fin contacts are used, despite differences in species and environmental conditions at the two sites. Differences in contact rates for calves between the two sites suggest that calf-focused aggression from adult dolphins is more prevalent at Mikura than in The Bahamas. Our results suggest that pectoral fin contact behaviour seems to be driven primarily by social pressures, and may be similar in function to allogrooming described in primates. ?? 2008 Elsevier B.V.

  1. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    Science.gov (United States)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K.

    2016-07-01

    Mixed convection flow in enclosures has been a subject of interest for many years due to their ever increasing applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. In comparison, little effort has been given to the problem of mixed convection in enclosures filled with nanofluids, while the addition of nanoparticles in a fluid base to alter specific material properties is considered a feasible solution for many heat transfer problems. Mixed convection of nanofluids is a challenging problem as the addition of nanoparticles changes the fluid's thermo-physical properties as well as due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, a two-dimensional steady-state numerical model has been developed to investigate mixed convection flow of nanofluids in a square enclosure with an intruded rectangular fin and to optimize the fin geometry for maximizing the heat transfer using the Constructal design. The model has been developed using ANSYS-FLUENT for various fin geometries. Flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers for several geometries of the fin with the aim of maximizing the heat transfer from the fin to the surrounding flow. Outcome of this study provides important insight into the heat transfer behavior of nanofluids, which will help in developing novel geometries with enhanced and controlled heat transfer for solar collectors and electronic devices.

  2. Batoid locomotion: effects of speed on pectoral fin deformation in the little skate, Leucoraja erinacea.

    Science.gov (United States)

    Di Santo, Valentina; Blevins, Erin L; Lauder, George V

    2017-02-15

    Most batoids have a unique swimming mode in which thrust is generated by either oscillating or undulating expanded pectoral fins that form a disc. Only one previous study of the freshwater stingray has quantified three-dimensional motions of the wing, and no comparable data are available for marine batoid species that may differ considerably in their mode of locomotion. Here, we investigate three-dimensional kinematics of the pectoral wing of the little skate, Leucoraja erinacea , swimming steadily at two speeds [1 and 2 body lengths (BL) s -1 ]. We measured the motion of nine points in three dimensions during wing oscillation and determined that there are significant differences in movement amplitude among wing locations, as well as significant differences as speed increases in body angle, wing beat frequency and speed of the traveling wave on the wing. In addition, we analyzed differences in wing curvature with swimming speed. At 1 BL s -1 , the pectoral wing is convex in shape during the downstroke along the medio-lateral fin midline, but at 2 BL s -1 the pectoral fin at this location cups into the flow, indicating active curvature control and fin stiffening. Wing kinematics of the little skate differed considerably from previous work on the freshwater stingray, which does not show active cupping of the whole fin on the downstroke. © 2017. Published by The Company of Biologists Ltd.

  3. Two-dimensional nonlinear transient heat transfer analysis of variable section pin fins

    Energy Technology Data Exchange (ETDEWEB)

    Malekzadeh, P. [Department of Mechanical Engineering, School of Engineering, Persian Gulf University, Boushehr 75168 (Iran); Rahideh, H. [Department of Chemical Engineering, School of Engineering, Persian Gulf University, Boushehr 75168 (Iran)

    2009-04-15

    The two-dimensional nonlinear transient heat transfer analysis of variable cross section pin-fins is studied using the incremental differential quadrature method (IDQM) as a simple, accurate, and computationally efficient numerical tool. The formulations are general so that it can easily be used for arbitrary continuously varying cross section pin fins with the spatial-temperature dependent thermal parameters. On all external surfaces of the pin fin, the convective-radiative condition is considered. The effects of two different types of boundary conditions at the base of pin fin are investigated: time and spatial dependent temperature, and the convection heat transfer. The thermal conductivity of the pin fin is assumed to vary as a linear function of the temperature. The accuracy of the method is demonstrated by comparing its results with those generated by finite difference method. It is shown that using few grid points, results in excellent agreements with those of FDM are obtained. Less computational efforts of the method with respect to finite difference method is shown. (author)

  4. Turbulent Heat Transfer of a Finned Plate in a Duct as Tip Clearance Changes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hae-Kyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    Fins are employed to enhance the cooling performance of a system. There are a number of studies relevant to geometry of fins. Meanwhile, the studies relevant to tip clearance, have not performed enough, which is the distance between the tips of the fins and the wall. We investigated the optimal tip clearance, which maximizes the heat transfers by experimental and numerical analyses with wider range of Re{sub Dh} than the previous studies. Turbulent heat transfers of a finned plate were measured. For an extended range of tip clearance and Re{sub Dh} than other studies. A joint experimental and numerical analyses was performed to measure heat transfers. Mass transfer experiments using electroplating system was used and FLUENT 6.3.26 was used for the calculation. For the narrow tip clearances below 5 mm, were investigated by numerical method only. The bypass flow to the tip clearance region contributes to heat transfer area at the tip clearance region and does not contributes that of the fin region. Thus, the optimal tip clearance was founded and it exists vicinity of 0.2 mm.

  5. Experimental investigations of heat transfer from an internally finned two phase closed thermosyphon

    International Nuclear Information System (INIS)

    Naresh, Y.; Balaji, C.

    2017-01-01

    Highlights: • Experimental investigations on an internally finned vertical thermosyphon. • Two fluids – water and acetone considered. • Optimum fill ratio determined to be 50%. • Addition of internal fins at the condenser leads to improved thermal performance. - Abstract: This paper reports the results of an experimental investigation of heat transfer from an internally finned thermosyphon charged with either water or acetone. Six constant area fins with a rectangular cross section are placed internally along the length at the condenser section. The ratio of initial liquid pool volume to the evaporator volume, known as the filling ratio in a thermosyphon system, has been varied in this study. Experiments are carried out for filling ratios of 20, 50, and 80% for two working fluids (i) water and (ii) acetone. Results show that a fill ratio of 50% gives better heat transfer performance. Providing internal fins at the condenser produces additional condensation which improves the thermal performance of the thermosyphon by 17% in terms of the temperature reduction at the source and sink and 35.48% in terms of reduction in thermal resistance at lower heat inputs. The thermosyphon is tested between power levels of 50 and 275 W.

  6. A comparative analysis on the shed vortices from the wake of finned, foam-wrapped cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Khashehchi, Morteza [Department of Agro-Technology, College of Aburaihan, University of Tehran, Tehran (Iran, Islamic Republic of); Ashtiani Abdi, Iman; Hooman, Kamel, E-mail: m.khashehchi@ut.ac.ir [School of Mechanical and mining Engineering, University of Queensland, Brisbane (Australia)

    2017-08-15

    The wake characteristics behind a finned and a foam-wrapped circular cylinder has been compared in a study (Khashehchi et al 2014 Exp. Therm. Fluid Sci. 52 328–38) done by the Authors. In this paper, the shed vortices from the wake of the same cylinders have been studied. Shedding in a bluff body has an important effect on increasing the pressure drop downstream of the object. Here, we have used particle image velocimetry to investigate the detached vortices from the wake behind a foam-wrapped and a finned cylinder. The standard case of cross-flow over a bare cylinder, i.e. no surface extension, has also been tested as a benchmark. The experiments have been performed for Reynolds numbers 2000 based on the mean air velocity and the cylinder’s outer diameter. To identify the features of each aforementioned case, linear stochastic estimation has been applied to the velocity fields. Results show that unlike the fin, adding foam to the cylinder surface increases the size of detached vortices and amplifies the core strength. Moreover, foam-wrapped cylinder in contrast to the finned one produces strong three-dimensionality. Interestingly, finned cylinder’s results show less three-dimensionality compared to the bare cylinder. (paper)

  7. Structure and Output Characteristics of a TEM Array Fitted to a Fin Heat Exchanger

    Science.gov (United States)

    Zhang, Z.; Chen, L. N.; Chen, Z. J.; Xiao, G. Q.; Liu, Z. J.

    2015-06-01

    In the design of a thermoelectric generator, both the heat transfer area and the number of thermoelectric modules (TEMs) should be increased accordingly as the generator power increases; crucially, both aspects need to be coordinated. A kilowatt thermoelectric generator with a fin heat exchanger is proposed for use in a constant-speed diesel generator unit. Interior fins enhance convective heat transfer, whereas an exterior fin segment increases the heat transfer area. The heat transfer surface is double that of a plane heat exchanger, and the temperature field over the exterior fins is constrained to a one-dimensional distribution. Between adjoining exterior fins, there is a cooling water channel with trapezoid cross-section, enabling compact TEMs and cooling them. Hence, more TEMs are built as a series-parallel array of TEMs with lower resistance and more stable output current. Under nonuniform conditions, to prevent circulation and energy loss, bypass diodes and antidiodes are added. Experiments and numerical calculations show that, with matching and optimization of the heat exchanger and TEM array, a stable maximum output power is obtainable from the interior of the thermoelectric generator system, which can be connected to an external maximum power point tracking system.

  8. Performance measurement of plate fin heat exchanger by exploration: ANN, ANFIS, GA, and SA

    Directory of Open Access Journals (Sweden)

    A.K. Gupta

    2017-01-01

    Full Text Available An experimental work is conducted on counter flow plate fin compact heat exchanger using offset strip fin under different mass flow rates. The training, testing, and validation set of data has been collected by conducting experiments. Next, artificial neural network merged with Genetic Algorithm (GA utilized to measure the performance of plate-fin compact heat exchanger. The main aim of present research is to measure the performance of plate-fin compact heat exchanger and to provide full explanations. An artificial neural network predicted simulated data, which verified with experimental data under 10–20% error. Then, the authors examined two well-known global search techniques, simulated annealing and the genetic algorithm. The proposed genetic algorithm and Simulated Annealing (SA results have been summarized. The parameters are impartially important for good results. With the emergence of a new data-driven modeling technique, Neuro-fuzzy based systems are established in academic and practical applications. The neuro-fuzzy interference system (ANFIS has also been examined to undertake the problem related to plate-fin heat exchanger performance measurement under various parameters. Moreover, Parallel with ANFIS model and Artificial Neural Network (ANN model has been created with emphasizing the accuracy of the different techniques. A wide range of statistical indicators used to assess the performance of the models. Based on the comparison, it was revealed that technical ANFIS improve the accuracy of estimates in the small pool and tropical ANN.

  9. Life-long preservation of the regenerative capacity in the fin and heart in zebrafish

    Directory of Open Access Journals (Sweden)

    Junji Itou

    2012-06-01

    The zebrafish is a widely used model animal to study the regeneration of organs, such as the fin and heart. Their average lifetime is about 3 years, and recent studies have shown that zebrafish exhibit aging-related degeneration, suggesting the possibility that aging might affect regenerative potential. In order to investigate this possibility, we compared regeneration of the fin and heart after experimental amputation in young (6–12 month old and old (26–36 month old fish. Comparison of recovery rate of the caudal fin, measured every two or three days from one day post amputation until 13 days post amputation, show that fins in young and old fish regenerate at a similar rate. In the heart, myocardium regeneration and cardiomyocyte proliferation occurred similarly in the two groups. Moreover, neo-vascularization, as well as activation of fibroblast growth factor signaling, which is required for neo-vascularization, occurred similarly. The epicardial tissue is a thin layer tissue that covers the heart, and starts to express several genes immediately in response to injury. The expression of epicardial genes, such as wt1b and aldh1a2, in response to heart injury was comparable in two groups. Our results demonstrate that zebrafish preserve a life-long regenerative ability of the caudal fin and heart.

  10. Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage.

    Science.gov (United States)

    Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

    2014-07-01

    In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and 2.86 days and were quicker compared with that in the UV only group (4.21 days); (2) zebrafish fins in the UV+comfrey (50 and 100 ppm) groups were 2.05 and 3.25 times more likely to return to normal than those in the UV only group; and (3) comfrey leave extracts had UV-absorbance abilities and significantly reduced ROS production in UV-exposed zebrafish embryos, which may attenuate UV-mediated apoptosis. In conclusion, comfrey leaves extracts may have the potential to be developed as UV-protective agents to protect zebrafish embryos from UV-induced damage.

  11. Effects of Tube Diameter and Tubeside Fin Geometry on the Heat Transfer Performance of Air-Cooled Condensers

    Science.gov (United States)

    Wang, H. S.; Honda, Hiroshi

    A theoretical study has been made on the effects of tube diameter and tubeside fin geometry on the heat transfer performance of air-cooled condensers. Extensive numerical calculations of overall heat transfer from refrigerant R410A flowing inside a horizontal microfin tube to ambient air were conducted for a typical operating condition of the air-cooled condenser. The tubeside heat transfer coefficient was calculated by applying a modified stratified flow model developed by Wang et al.8). The numerical results show that the effects of tube diameter, fin height, fin number and helix angle of groove are significant, whereas those of the width of flat portion at the fin tip, the radius of round corner at the fin tip and the fin half tip angle are small.

  12. A Study on Aspect Ratio of Heat Dissipation Fin for the Heat Dissipation Performance of Ultra Constant Discharge Lamp

    Science.gov (United States)

    Ko, Dong Guk; Cong Ge, Jun; Im, Ik Tae; Choi, Nag Jung; Kim, Min Soo

    2018-01-01

    In this study, we analyzed the heat dissipation performance of UCD lamp ballast fin with various aspect ratios. The minimum grid size was 0.02 mm and the number of grid was approximately 11,000. In order to determine the influence of the aspect ratio on the heat dissipation performance of UCD lamp ballast fin, the heat transfer area of the fin was kept constant at 4 mm2. The aspect ratios of the fin were 2 mm: 2 mm (basic model), 1.5 mm: 2.7 mm and 2.7 mm: 1.5 mm, respectively. The heat flux and heat flux time at fin were kept constant at 1×105 W/m2 and 10 seconds, respectively. The heat dissipation performance by the fin was the best at an aspect ratio of 1.5 mm: 2.7 mm.

  13. Collector Efficiency in Downward-Type Double-Pass Solar Air Heaters with Attached Fins and Operated by External Recycle

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2012-07-01

    Full Text Available The collector efficiency in a downward-type double-pass external-recycle solar air heater with fins attached on the absorbing plate has been investigated theoretically. Considerable improvement in collector efficiency is obtainable if the collector is equipped with fins and the operation is carried out with an external recycle. Due to the recycling, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperature difference of heat transfer, while the attached fins provide an enlarged heat transfer area. The order of performances in the devices of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

  14. Heat transfer and pressure drop amidst frost layer presence for the full geometry of fin-tube heat exchanger

    International Nuclear Information System (INIS)

    Kim, Sung Jool; Choi, Ho Jin; Ha, Man Yeong; Kim, Seok Ro; Bang, Seon Wook

    2010-01-01

    The present study numerically solves the flow and thermal fields in the full geometry of heat exchanger modeling with frost layer presence on the heat exchanger surface. The effects of air inlet velocity, air inlet temperature, frost layer thickness, fin pitch, fin thickness, and heat exchanger shape on the thermo-hydraulic performance of a fin-tube heat exchanger are investigated. Heat transfer rate rises with increasing air inlet velocity and temperature, and decreasing frost layer thickness and fin pitch. Pressure drop rises with increasing air inlet velocity and frost layer thickness, and decreasing fin pitch. The effect of fin thickness on heat transfer and pressure drop is negligible. Based on the present results, we derived the correlations, which express pressure drop and temperature difference between air inlet and outlet as a function of air inlet velocity and temperature, as well as frost layer thickness

  15. A Theoretical Study of Steady State and Transient Condensation on Axisymmetric Fins Under Combined Capillary and Gravitational Forces

    Science.gov (United States)

    Kostoglou, M.; Karapantsios, T. D.; Buffone, C.; Glushchuk, A.; Iorio, C.

    2016-10-01

    The present work attempts to model the case of combined gravitational and capillary motion of condensate for an axisymmetric fin under steady and transient fin operation conditions. The focus here is to examine the structure of the mathematical problem and to develop suitable numerical techniques rather than yield information on the macroscopic condensate flow rate and fin efficiency. The problem is formulated starting from general conditions and is simplified step by step by introducing corresponding assumptions. The particular fin shape of a paraboloid from revolution is chosen and the equations are properly non-dimensionalized. A vast reduction of the number of problem parameters is achieved in this way. The cases of isothermal fin, steady state operation and dynamic operation are treated separately using specialized numerical solution techniques developed for each case in order to improve computational efficiency and accuracy. Typical results of fin temperature and condensate film thickness are presented and discussed.

  16. Strain characterization of fin-shaped field effect transistors with SiGe stressors using nanobeam electron diffraction

    International Nuclear Information System (INIS)

    Kim, Sun-Wook; Byeon, Dae-Seop; Jang, Hyunchul; Koo, Sang-Mo; Ko, Dae-Hong; Lee, Hoo-Jeong

    2014-01-01

    This study undertook strain analysis on fin-shaped field effect transistor structures with epitaxial Si 1−x Ge x stressors, using nano-beam electron diffraction and finite elements method. Combining the two methods disclosed dynamic strain distribution in the source/drain and channel region of the fin structure, and the effects of dimensional factors such as the stressor thickness and fin width, offering valuable information for device design.

  17. Aluminum-based one- and two-dimensional micro fin array structures: high-throughput fabrication and heat transfer testing

    International Nuclear Information System (INIS)

    Primeaux, Philip A; Zhang, Bin; Zhang, Xiaoman; Miller, Jacob; Meng, W J; KC, Pratik; Moore, Arden L

    2017-01-01

    Microscale fin array structures were replicated onto surfaces of aluminum 1100 and aluminum 6061 alloy (Al1100/Al6061) sheet metals through room-temperature instrumented roll molding. Aluminum-based micro fin arrays were replicated at room temperature, and the fabrication process is one with high throughput and low cost. One-dimensional (1D) micro fin arrays were made through one-pass rolling, while two-dimensional (2D) micro fin arrays were made by sequential 90° cross rolling with the same roller sleeve. For roll molding of 1D micro fins, fin heights greater than 600 µ m were achieved and were shown to be proportional to the normal load force per feature width. At a given normal load force, the fin height was further shown to scale inversely with the hardness of the sheet metal. For sequential 90° cross rolling, morphologies of roll molded 2D micro fin arrays were examined, which provided clues to understand how plastic deformation occurred under cross rolling conditions. A series of pool boiling experiments on low profile Al micro fin array structures were performed within Novec 7100, a widely used commercial dielectric coolant. Results for both horizontal and vertical surface orientations show that roll molded Al micro fin arrays can increase heat flux at fixed surface temperature as compared to un-patterned Al sheet. The present results further suggest that many factors beyond just increased surface area can influence heat transfer performance, including surface finish and the important multiphase transport mechanisms in and around the fin geometry. These factors must also be considered when designing and optimizing micro fin array structures for heat transfer applications. (paper)

  18. Strain characterization of fin-shaped field effect transistors with SiGe stressors using nanobeam electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun-Wook; Byeon, Dae-Seop; Jang, Hyunchul; Koo, Sang-Mo; Ko, Dae-Hong, E-mail: dhko@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Hoo-Jeong, E-mail: hlee@skku.edu [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-08-25

    This study undertook strain analysis on fin-shaped field effect transistor structures with epitaxial Si{sub 1−x}Ge{sub x} stressors, using nano-beam electron diffraction and finite elements method. Combining the two methods disclosed dynamic strain distribution in the source/drain and channel region of the fin structure, and the effects of dimensional factors such as the stressor thickness and fin width, offering valuable information for device design.

  19. Design and Analyze a New Measuring Lift Device for Fin Stabilizers Using Stiffness Matrix of Euler-Bernoulli Beam.

    Directory of Open Access Journals (Sweden)

    Lihua Liang

    Full Text Available Fin-angle feedback control is usually used in conventional fin stabilizers, and its actual anti-rolling effect is difficult to reach theoretical design requirements. Primarily, lift of control torque is a theoretical value calculated by static hydrodynamic characteristics of fin. However, hydrodynamic characteristics of fin are dynamic while fin is moving in waves. As a result, there is a large deviation between actual value and theoretical value of lift. Firstly, the reasons of deviation are analyzed theoretically, which could avoid a variety of interference factors and complex theoretical derivations. Secondly, a new device is designed for direct measurement of actual lift, which is composed of fin-shaft combined mechanism and sensors. This new device can make fin-shaft not only be the basic function of rotating fin, but also detect actual lift. Through analysis using stiffness matrix of Euler-Bernoulli beam, displacement of shaft-core end is measured instead of lift which is difficult to measure. Then quantitative relationship between lift and displacement is defined. Three main factors are analyzed with quantitative relationship. What is more, two installation modes of sensors and a removable shaft-end cover are proposed according to hydrodynamic characteristics of fin. Thus the new device contributes to maintenance and measurement. Lastly, the effectiveness and accuracy of device are verified by contrasting calculation and simulation on the basis of actual design parameters. And the new measuring lift method can be proved to be effective through experiments. The new device is achieved from conventional fin stabilizers. Accordingly, the reliability of original equipment is inherited. The alteration of fin stabilizers is minor, which is suitable for engineering application. In addition, the flexural properties of fin-shaft are digitized with analysis of stiffness matrix. This method provides theoretical support for engineering application by

  20. Small Tails Tell Tall Tales--Intra-Individual Variation in the Stable Isotope Values of Fish Fin.

    Directory of Open Access Journals (Sweden)

    Brian Hayden

    Full Text Available Fish fin is a widely used, non-lethal sample material in studies using stable isotopes to assess the ecology of fishes. However, fish fin is composed of two distinct tissues (ray and membrane which may have different stable isotope values and are not homogeneously distributed within a fin. As such, estimates of the stable isotope values of a fish may vary according to the section of fin sampled.To assess the magnitude of this variation, we analysed carbon (δ13C, nitrogen (δ15N, hydrogen (δ2H and oxygen (δ18O stable isotopes of caudal fin from juvenile, riverine stages of Atlantic salmon (Salmo salar and brown trout (Salmo trutta. Individual fins were sub-sectioned into tip, mid and base, of which a further subset were divided into ray and membrane.Isotope variation between fin sections, evident in all four elements, was primarily related to differences between ray and membrane. Base sections were13C depleted relative to tip (~1‰ with equivalent variation evident between ray and membrane. A similar trend was evident in δ2H, though the degree of variation was far greater (~10‰. Base and ray sections were 18O enriched (~2‰ relative to tip and membrane, respectively. Ray and membrane sections displayed longitudinal variation in 15N mirroring that of composite fin (~1‰, indicating that variation in15N values was likely related to ontogenetic variation.To account for the effects of intra-fin variability in stable isotope analyses we suggest that researchers sampling fish fin, in increasing priority, 1 also analyse muscle (or liver tissue from a subsample of fish to calibrate their data, or 2 standardize sampling by selecting tissue only from the extreme tip of a fin, or 3 homogenize fins prior to analysis.

  1. Genetic Architecture of the Variation in Male-Specific Ossified Processes on the Anal Fins of Japanese Medaka.

    Science.gov (United States)

    Kawajiri, Maiko; Fujimoto, Shingo; Yoshida, Kohta; Yamahira, Kazunori; Kitano, Jun

    2015-10-28

    Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTL with previously identified QTL controlling anal fin length. First, we found that only a few QTL were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays often were controlled by different QTL. Finally, we produced another independent cross and found that some QTL were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTL that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTL and have the potential for independent evolution. Copyright © 2015 Kawajiri et al.

  2. Numerical analysis on interactions between fluid flow and structure deformation in plate-fin heat exchanger by Galerkin method

    Science.gov (United States)

    Liu, Jing-cheng; Wei, Xiu-ting; Zhou, Zhi-yong; Wei, Zhen-wen

    2018-03-01

    The fluid-structure interaction performance of plate-fin heat exchanger (PFHE) with serrated fins in large scale air-separation equipment was investigated in this paper. The stress and deformation of fins were analyzed, besides, the interaction equations were deduced by Galerkin method. The governing equations of fluid flow and heat transfer in PFHE were deduced by finite volume method (FVM). The distribution of strain and stress were calculated in large scale air separation equipment and the coupling situation of serrated fins under laminar situation was analyzed. The results indicated that the interactions between fins and fluid flow in the exchanger have significant impacts on heat transfer enhancement, meanwhile, the strain and stress of fins includes dynamic pressure of the sealing head and flow impact with the increase of flow velocity. The impacts are especially significant at the conjunction of two fins because of the non-alignment fins. It can be concluded that the soldering process and channel width led to structure deformation of fins in the exchanger, and degraded heat transfer efficiency.

  3. The stress characteristics of plate-fin structures at the different operation parameters of LNG heat exchanger

    Directory of Open Access Journals (Sweden)

    Ma Hongqiang

    2018-01-01

    Full Text Available In this paper, the stresses of plate-fin structures at the different operation parameters were analyzed in actual operation process of LNG plate-fin heat exchanger based on finite element method and thermal elastic theory. Stress characteristics of plate-fin structures were investigated at the different operation parameters of that. The results show that the structural failure of plate-fin structures is mainly induced by the maximum shear stress at the brazing filler metal layer between plate and fin while by the maximum normal stress in the region of brazed joint near the fin side. And a crack would initiate in brazed joint near the fin side. The maximum normal stress is also main factor to result in the structural failure of plate-fin structures at the different temperature difference (between Natural Gas (NG and Mixture Refrigerant (MR, MR temperature and NG pressure of LNG heat exchanger. At the same time, the peak stresses obviously increase as the temperature difference, MR temperature and NG pressure increase. These results will provide some constructive instructions in the safe operation of LNG plate-fin heat exchanger in a large-scale LNG cold-box.

  4. The sexually dimorphic adipose fin is an androgen target tissue in the brown trout (Salmo trutta fario).

    Science.gov (United States)

    Hisar, Olcay; Sönmez, Adem Yavuz; Hisar, Şükriye Aras; Budak, Harun; Gültepe, Nejdet

    2013-04-01

    An investigation has been described on the relationship of body length, age and sex with adipose fin length and the number of androgen receptor (AR)-containing cells in the adipose fin as a secondary sexual characteristic for brown trout (Salmo trutta fario). Firstly, body and adipose fin lengths of 2- to 5-year-old brown trout were measured. Thereafter, these fish were killed by decapitation, then their sexes were determined, and adipose fins were excised. The cellular bases of AR binding activities in the adipose fins were analyzed with an antibody against human/rat AR peptide. Immunocytochemistry and western blotting techniques were performed with this antibody. Analysis of morphological measurements indicated that body length and age had a linear relationship with adipose fin length. The coefficients of determination for the body length and age were 0.92 and 0.85 in the male fish and 0.76 and 0.73 in the female fish against the adipose fin length, respectively. At 2 years of age, cells in the adipose fin did not exhibit AR immunoreactivity. However, AR-immunopositive cells were abundant in the adipose fin of 3- to 5-year-old fish. Moreover, the number of AR-immunopositive cells was significantly (P brown trout is a probable target for androgen action and that tissue function or development may to some extent be androgen dependent. In addition, it is likely that such an effect will be mediated by specific androgen receptors.

  5. Numerical analysis of steady state and transient analysis of high temperature ceramic plate-fin heat exchanger

    International Nuclear Information System (INIS)

    Nagarajan, Vijaisri; Chen, Yitung; Wang, Qiuwang; Ma, Ting

    2014-01-01

    Highlights: • Rip saw fin design is considered to be the best because it has thin fins and has higher heat transfer coefficient. • Minimum principal stress and maximum safety factor are obtained for the inverted bolt fin design. • Maximum principal stress and minimum safety factor are obtained for triangular fin design. • Thermal stress has significant impact than mechanical stress. • High principal stress is found at the startup and shutdown stage. - Abstract: In this study three-dimensional model of ceramic plate-fin high temperature heat exchanger with different fin designs and arrangements is analyzed numerically using ANSYS FLUENT and ANSYS structural module. The ability of ceramics to withstand high temperature and corrosion makes silicon carbide (SiC) suitable candidate material to be used in high temperature heat exchanger. The operating temperature of heat exchanger is 950 °C and the operating pressure is 1.5 MPa. The working fluids are helium, sulfur trioxide, sulfur dioxide, oxygen and the water vapor. Fluid flow and heat transfer analysis are carried out for steady and transient state in FLUENT. The obtained thermal and pressure load for the steady and transient state from ANSYS FLUENT are imported to ANSYS structural module to obtain the principal stress and the factor of safety. Different arrangements of rectangular fins, triangular fins, inverted bolt fins and ripsaw fins are studied. From the results it is found that the minimum stress and the maximum safety factor are obtained for inverted bolt fins. The triangular fins have the maximum principal stress and minimum factor of safety. However, the fluid flow and heat transfer analysis show inverted bolt fins and triangular fins produce higher pressure drop and friction factor. The steady state maximum principal stress is 10.08 MPa, 9.90 MPa and 11.43 MPa for straight, staggered and top and bottom ripsaw fin arrangement. The corresponding safety factors are 21.80, 21.95 and 19

  6. Enhanced heat transfer in partially open square cavities with thin fin by using electric field

    International Nuclear Information System (INIS)

    Kasayapanand, N.; Kiatsiriroat, T.

    2009-01-01

    Numerical modeling of the electric field effect on the natural convection in the partially open square cavities with thin fin attached is investigated. The interactions among electric, flow, and temperature fields are analyzed by using a computational fluid dynamics technique. It is found that the flow and heat transfer enhancements are a decreasing function of the Rayleigh number. Moreover, the volume flow rate and heat transfer coefficient are substantially improved by electrohydrodynamic especially at low aperture size, high aperture position, and high inclined angle. Surprisingly, the maximum convective heat transfer is obtained at the minimum electrical energy consumption by placing electrodes at a suitable position. The optimum electrode arrangements for both single fin and multiple fins are also achieved

  7. Copper vertical micro dendrite fin arrays and their superior boiling heat transfer capability

    Science.gov (United States)

    Wang, Ya-Qiao; Lyu, Shu-Shen; Luo, Jia-Li; Luo, Zhi-Yong; Fu, Yuan-Xiang; Heng, Yi; Zhang, Jian-Hui; Mo, Dong-Chuan

    2017-11-01

    Micro pin fin arrays have been widely used in electronic cooling, micro reactors, catalyst support, and wettability modification and so on, and a facile way to produce better micro pin fin arrays is demanded. Herein, a simple electrochemical method has been developed to fabricate copper vertical micro dendrite fin arrays (Cu-VMDFA) with controllable shapes, number density and height. High copper sulphate concentration is one key point to make the dendrite stand vertically. Besides, the applied current should rise at an appropriate rate to ensure the copper dendrite can grow vertically on its own. The Cu-VMDFA can significantly enhance the heat transfer coefficient by approximately twice compared to the plain copper surface. The Cu-VMDFA may be widely used in boiling heat transfer areas such as nuclear power plants, electronic cooling, heat exchangers, and so on.

  8. Charge based DC compact modeling of bulk FinFET transistor

    Science.gov (United States)

    Cerdeira, A.; Garduño, I.; Tinoco, J.; Ritzenthaler, R.; Franco, J.; Togo, M.; Chiarella, T.; Claeys, C.

    2013-09-01

    Multiple-gate MOSFETs became an industrial reality in the last years. Due to a pragmatic trade-off between CMOS process baselines compatibility, improved performance compared to planar bulk architecture, and cost, bulk FinFETs emerged as the technological solution to provide downscaling for the 14/22 nm technological nodes. In this work, a charge based DC compact model based on the SDDG Model is demonstrated for this new generation of FinFET transistors and describes continuously the transistor characteristics in all operating regions. Validating the model against two bulk FinFET baselines (NMOS, PMOS, various gate lengths and EOT), an excellent agreement is found for transfer and output characteristics (linear and saturation regimes), transconductance/output conductance, and gm/IDS characteristics. Temperature dependence is also taken into account and validated (T range from 25 °C up to 175 °C).

  9. Inverse analysis of a rectangular fin using the lattice Boltzmann method

    International Nuclear Information System (INIS)

    Bamdad, Keivan; Ashorynejad, Hamid Reza

    2015-01-01

    Highlights: • Lattice Boltzmann method is used to study a transient conductive-convective fin. • LBM and Conjugate Gradient Method (CGM) are used to solve an inverse problem in fins. • LBM–ACGM estimates the unknown boundary conditions of fins accurately. • The accuracy and CPU time of LBM–ACGM are compared to IFDM–ACGM. • LBM–ACGM could be a good alternative for the conventional inverse methods. - Abstract: Inverse methods have many applications in determining unknown variables in heat transfer problems when direct measurements are impossible. As most common inverse methods are iterative and time consuming especially for complex geometries, developing more efficient methods seems necessary. In this paper, a direct transient conduction–convection heat transfer problem (fin) under several boundary conditions was solved by using lattice Boltzmann method (LBM), and then the results were successfully validated against both the finite difference method and analytical solution. Then, in the inverse problem both unknown base temperatures and heat fluxes in the rectangular fin were estimated by combining the adjoint conjugate gradient method (ACGM) and LBM. A close agreement between the exact values and estimated results confirmed the validity and accuracy of the ACGM–LBM. To compare the calculation time of ACGM–LBM, the inverse problem was solved by implicit finite difference methods as well. This comparison proved that the ACGM–LBM was an accurate and fast method to determine unknown thermal boundary conditions in transient conduction–convection heat transfer problems. The findings can efficiently determine the unknown variables in fins when a desired temperature distribution is available

  10. Plan de negocios para la creación de una empresa comercializadora de un sistema automático contra incendios para vehículos

    OpenAIRE

    García Monroy, Miguel Ángel

    2013-01-01

    El trabajo formula el plan de negocios para crear una empresa ubicada en Bogotá, que vende, instala y realiza el mantenimiento de un sistema automático contra incendios para vehículos; esto con el fin de mejorar los sistemas de seguridad y protección de los autos, para así combatir la problemática real y alarmante de incendios vehiculares, que traen como consecuencia la pérdida de vidas humanas, materiales o monetarias y daños medioambientales irreparables

  11. Estudio de Factibilidad para la Implementación de un ERP como Software como Servicio para la fuerza de ventas de una PYME

    OpenAIRE

    Artola Jarrín, Cyntia Lorena

    2014-01-01

    84 hojas : ilustraciones, 29 x 21 cm + CD-ROM 3681 La cobertura de esta tesis es proporcionar a los empresarios de las Pymes los conocimientos necesarios sobre el proceso y desarrollo en la verificación de la factibilidad de implementar un ERP como Software como Servicio, para potencializar y automatizar los procesos de la organización, con la finalidad de tener la información en tiempo real para la toma de decisiones oportunas. El fin de esta tesis es formar un manual de consulta para el ...

  12. ¿El fin de pensar en enfermedad mental?

    Directory of Open Access Journals (Sweden)

    Richard Pemberton

    2014-01-01

    Full Text Available La teoría y la práctica de la salud mental se encuentran en un momento de cambios significativos. El objetivo de este artículo teórico es mostrar la posición adoptada por la British Psychological Society Division of Clinical Psychology (DCP en el contexto de la práctica actual, tratando de analizar de forma crítica algunos de los factores clave que impulsan estos cambios. La necesidad de una revisión completa de los planteamientos actuales procede del mal funcionamiento de los servicios de salud mental en los que las personas con graves problemas de salud mental han reducido la esperanza de vida. Se aboga por el uso de los avances en los conocimientos de los mecanismos psicológicos, sociales y físicos que sustentan el bienestar psicológico y la angustia mental, rechazando el modelo de enfermedad de la ésta como parte de un paradigma obsoleto. Los avances de la investigación en genética, neurociencia, psicología y teoría social proporcionan la plataforma para cambiar la manera en que conceptualizamos, formulamos y respondemos al sufrimiento psicológico, tanto a nivel comunitario como individual.

  13. Jóvenes, transiciones y el fin de las certidumbres

    Directory of Open Access Journals (Sweden)

    Camilo Soares

    2000-01-01

    Full Text Available El artículo analiza a la "juventud" en proceso de transición, tanto en el sentido de los momentos político, económico y cultural del mundo actual como la juventud misma como un "momento de transición"; e intenta una aproximación al espacio y a las perspectivas de los movimientos juveniles en la actualidad. Teniendo en cuenta el marco general en el que se desarrolla la vida de los y las jóvenes actualmente, el trabajo realiza una aproximación al concepto de "juventud", a su origen y desarrollo. Parte de la idea de que la juventud no es una "transición" entre la niñez y la vida adulta, sino un momento "en sí". El desafío consiste en repensar a la juventud no sólo asociándola a las ideas de cambio, propuestas y renovación, sino como un mismo momento, con ilusiones y expectativas propias, en toda su pluralidad para elaborar alternativas identitarias frente al actual modelo globalizante.

  14. Historia del Pensamiento Político Premoderno 05 Fin de la polis. Alejandro Magno

    OpenAIRE

    Sanz Díaz, Benito

    2010-01-01

    Tema 5 El fin de la polis y el surgimiento de nuevas escuelas filosóficas 1.- El declive de la polis griega 2.- Transformación, decadencia y fin de las polis griegas 3.- Filipo II de Macedonia 4.- Alejandro Magno 5.- Helenismo y nuevas concepciones políticas 6.- Epicureismo. Epicuro de Samos 7.- Los cínicos. Ni hogar ni patria, ni ciudad ni ley 8.- El estoicismo. El estoico es un ciudadano del mundo. El cosmopolitismo. La stoa 9.- Las Meditaciones de Marco Aurel...

  15. Experimental study on void fraction of two-phase flow inside a micro-fin tube

    OpenAIRE

    Koyama, Shigeru; Chen, Yongchang; Kitano, Ryuji; Kuwahara, Ken

    2001-01-01

    In this paper the void fraction and flow pattern of the two-phase flow in a micro-fin tube were investigated experimentally for a pure refrigerant HFC134a. The experiment was carried out at a pressure range of 0.6 and 1.2MPa with mass velocities of 90 and 180kg/m^2 s, in which the vapor quality varied from 0 to 1. The void fraction was measured by means of simultaneously closing valves of both sides of the test tube at adiabatic condition. Experimental results for the micro-fin tube were comp...

  16. Heat transfer simulation of motorcycle fins under varying velocity using CFD method

    Science.gov (United States)

    Shahril, K.; Mohd Kasim, Nurhayati Binti; Sabri, M.

    2013-12-01

    Motorcycle engine releases heat to the atmosphere through the mode of force convection. To solve this, fins are provided on the outer of the cylinder. The heat transfer rate is defined depending on the velocity of vehicle, fin geometry and the ambient temperature. Increasing the temperature difference between the object and the environment, increasing the convection heat transfer coefficient, or increasing the surface area of the object increases the heat transfer. Many experimental methods are available in literature to analyze the effect of these factors on the heat transfer rate. However, CFD analysis will be use to simulate the heat transfer of the engine block. ANSYS software is selected to run the simulation.

  17. The Topology Optimization of Three-dimensional Cooling Fins by the Internal Element Connectivity Parameterization Method

    International Nuclear Information System (INIS)

    Yoo, Sung Min; Kim, Yoon Young

    2007-01-01

    This work is concerned with the topology optimization of three-dimensional cooling fins or heat sinks. Motivated by earlier success of the Internal Element Connectivity Method (I-ECP) method in two dimensional problems, the extension of I-ECP to three-dimensional problems is carried out. The main efforts were made to maintain the numerical trouble-free characteristics of I-ECP for full three-dimensional problems; a serious numerical problem appearing in thermal topology optimization is erroneous temperature undershooting. The effectiveness of the present implementation was checked through the design optimization of three-dimensional fins

  18. An analysis of the effect of endplates upon the fin keel of a sailing yacht

    International Nuclear Information System (INIS)

    Andrews, G.T.; Raiskums, C.L.; Keffer, J.F.

    1985-01-01

    A long-term investigation is presently underway to assess the overall performance of the modern design of fin keels for sailing yachts. An ultimate goal is to determine the specific advantages for such designs with respect to a centre-board configuration with outside ballast. The present preliminary studies were carried out to determine the basic performance of a typical fin keel shape for various values of leeway angle. A second aspect was to determine the effect upon this baseline performance of a number of endplates of varying sizes and shapes. (author)

  19. Inverse scaling trends for charge-trapping-induced degradation of FinFETs performance

    OpenAIRE

    Amoroso, Salvatore Maria; Georgiev, Vihar P.; Gerrer, Louis; Towie, Ewan; Wang, Xingsheng; Riddet, Craig; Brown, Andrew Robert; Asenov, Asen

    2014-01-01

    In this paper, we investigate the impact of a single discrete charge trapped at the top oxide interface on the performance of scaled nMOS FinFET transistors. The charge-trapping-induced gate voltage shift is simulated as a function of the device scaling and for several regimes of conduction-from subthreshold to ON-state. Contrary to what is expected for planar MOSFETs, we show that the trap impact decreases with scaling down the FinFET size and the applied gate voltage. By comparing drift-dif...

  20. The impact of FinTech start-ups on incumbent retail banks' share prices

    OpenAIRE

    Li, Yinqiao; Spigt, Renée; Swinkels, Laurens

    2017-01-01

    Background: This study aims to clarify the role of FinTech digital banking start-ups in the financial industry. We examine the impact of the funding of such start-ups on the stock returns of 47 incumbent US retail banks for 2010 to 2016. Methods: To capture the importance of FinTech start-ups, we use data on both the dollar-volume of funding and number of deals. We relate these to the stock returns with panel data regression methods. Results: Our results indicate a positive relationship exist...

  1. 3D analysis of thermal exchange in finned batteries. A comparison between round and elliptical tubes

    International Nuclear Information System (INIS)

    Valdiserri, P.

    2001-01-01

    In this paper a numerical 3D analysis of the thermal exchange in air-cooled finned batteries has been carried out. Speed and temperature values in each hub of the numerical simulation domain have been reckoned both at different air flows and with different shapes of the tubes. The thermal power exchanged between tubes and air is obtained by the simulation of a numerical model of a finned battery with round section tubes and is compared to the values obtained for three batteries with elliptical section tubes. The comparison has been performed for different values of the air input speed [it

  2. Structure and mechanical implications of the pectoral fin skeleton in the Longnose Skate (Chondrichthyes, Batoidea).

    Science.gov (United States)

    Huang, Wei; Hongjamrassilp, Watcharapong; Jung, Jae-Young; Hastings, Philip A; Lubarda, Vlado A; McKittrick, Joanna

    2017-03-15

    Animal propulsion systems are believed to show high energy and mechanical efficiency in assisting movement compared to artificial designs. As an example, batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming via enlarged wing-like pectoral fins. The aim of this work is to illustrate the hierarchical structure of the pectoral fin of a representative batoid, the Longnose Skate (Raja rhina), and explain the mechanical implications of its structural design. At the macro level, the pectoral fins are comprised of radially oriented fin rays, formed by staggered mineralized skeletal elements stacked end-to-end. At the micro level, the midsection of each radial element is composed of three mineralized components, which consist of discrete segments (tesserae) that are mineralized cartilage and embedded in unmineralized cartilage. The radial elements are wrapped with aligned, unmineralized collagen fibers. This is the first report of the detailed structure of the ray elements, including the observation of a 3-chain mineralized tesserae. Structural analyses demonstrate that this configuration enhances stiffness in multiple directions. A two-dimensional numerical model based on the morphological analysis demonstrated that the tessera structure helps distributing shear, tensile and compressive stress more ideally, which can better support both lift and thrust forces when swimming without losing flexibility. Batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming by applying their enlarged wing-like pectoral fins. Previous studies have shown structural features and mechanical properties of the mineralized cartilage skeleton in various batoid fishes. However, the details of the pectoral fin structure at different length scales, as well as the relationship between the mechanical properties and structural design remains unknown. The present work illustrates the hierarchical structure of the pectoral fin of

  3. FinTech来袭:重塑金融格局

    Institute of Scientific and Technical Information of China (English)

    李淼

    2016-01-01

    所谓FinTech,就是一种运用高科技来促使金融服务更加富有效率的商业模式。作为当下欧美金融圈、互联网圈极其风靡的概念,FinTech的核心是技术驱动金融创新,用创新的方法和模式改善用户体验,提高服务效率,重塑金融格局。

  4. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry\\'s most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  5. Comparison of fin-and-tube interlaced and face split evaporators with flow maldistribution and compensation

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Larsen, Lars Finn Sloth

    2013-01-01

    Flow maldistribution in fin-and tube evaporators for residential air-conditioning is investigated by numerical simulation. In particular, the interlaced and the face split evaporator are compared in flow maldistribution conditions. The considered sources of maldistribution are the liquid/vapor di......Flow maldistribution in fin-and tube evaporators for residential air-conditioning is investigated by numerical simulation. In particular, the interlaced and the face split evaporator are compared in flow maldistribution conditions. The considered sources of maldistribution are the liquid...

  6. Modeling Nanoscale FinFET Performance by a Neural Network Method

    Directory of Open Access Journals (Sweden)

    Jin He

    2017-07-01

    Full Text Available This paper presents a neural network method to model nanometer FinFET performance. The principle of this method is firstly introduced and its application in modeling DC and conductance characteristics of nanoscale FinFET transistor is demonstrated in detail. It is shown that this method does not need parameter extraction routine while its prediction of the transistor performance has a small relative error within 1 % compared with measured data, thus this new method is as accurate as the physics based surface potential model.

  7. “Estudiando cerca de casa”. Un acercamiento desde la perspectiva espacial a la experiencia del Plan FinEs2 en la ciudad de La Plata

    Directory of Open Access Journals (Sweden)

    Federico González

    2016-12-01

    Full Text Available Desde la perspectiva espacial, el presente artículo tiene como objetivo analizar cómo dos espacios, con tradiciones e historias distintas, son transformados por las mediaciones de una política pública y por el trabajo cotidiano que militantes de dos organizaciones llevan a cabo en los barrios donde se encuentran insertos. De esta forma, se intenta contribuir a las discusiones en torno a las relaciones entre espacio y política en el caso de la experiencia de una política pública de terminalidad educativa: el Plan FinEs2. Para ello, trabajamos a partir de dos investigaciones que desde una perspectiva cualitativa analizan las experiencias del Plan FinEs2 en dos barrios de la ciudad de La Plata. Como resultado, pudimos observar las formas en que estos dos espacios son transformados a partir de las relaciones tejidas entre la política, lo educativo y lo espacial.

  8. Los barrios parque y de fin de semana en el mapa de la expansión metropolitana: Buenos Aires, 1910-1950

    Directory of Open Access Journals (Sweden)

    Ana Gómez

    2015-01-01

    Full Text Available En el marco del interés que suscitan los recientes procesos de suburbanización protagonizados por los sectores medios y medios altos, surge la necesidad de identificar núcleos y emprendimientos suburbanos surgidos durante la primera mitad del siglo XX, pensándolos como antecedentes de los fenómenos actuales y partícipes en la formación del territorio metropolitano de Buenos Aires. Desde una perspectiva histórica, nos preguntamos cómo contribuyeron los barrios de fin de semana a producir una nueva configuración del Gran Buenos Aires (GBA. Del corpus de casos seleccionados surge que, más allá de los matices y del rol limitado que en términos materiales tuvieron los barrios de fin de semana en la expansión metropolitana, su relevancia radicó en su capacidad para consolidar los ejes de crecimiento y configurar en su irradiación formas particulares de la expansión.

  9. LA RESOCIALIZACIÓN COMO FIN DE LA PENA – una frustración en el sistema penitenciario y carcelario colombiano

    Directory of Open Access Journals (Sweden)

    Norberto Hernández Jiménez

    Full Text Available En este trabajo, se analiza la resocialización como fin principal de la pena privativa de la libertad en Colombia, durante su fase de ejecución. Para esto, se contextualiza la difícil situación por la que atraviesa el sistema penitenciario y carcelario colombiano que, conforme a lo declarado por la Corte Constitucional, se adecúa a un estado de cosas inconstitucional, donde la dignidad humana de las personas privadas de la libertad se encuentra seriamente comprometida. Dentro de esta realidad, que involucra un marcado hacinamiento carcelario, que, a su vez, propicia un ambiente de violencia, corrupción y desigualdad, la oferta y el acceso a los programas de resocialización son limitados, lo que impide la rehabilitación del individuo. La prueba de fuego en busca del cumplimiento de este fin no es superada, al observar como un gran porcentaje de los reclusos vuelve a prisión, dentro del fenómeno de la reincidencia.

  10. Fluid dynamics of flapping aquatic flight in the bird wrasse: three-dimensional unsteady computations with fin deformation.

    Science.gov (United States)

    Ramamurti, Ravi; Sandberg, William C; Löhner, Rainald; Walker, Jeffrey A; Westneat, Mark W

    2002-10-01

    Many fishes that swim with the paired pectoral fins use fin-stroke parameters that produce thrust force from lift in a mechanism of underwater flight. These locomotor mechanisms are of interest to behavioral biologists, biomechanics researchers and engineers. In the present study, we performed the first three-dimensional unsteady computations of fish swimming with oscillating and deforming fins. The objective of these computations was to investigate the fluid dynamics of force production associated with the flapping aquatic flight of the bird wrasse Gomphosus varius. For this computational work, we used the geometry of the wrasse and its pectoral fin, and previously measured fin kinematics, as the starting points for computational investigation of three-dimensional (3-D) unsteady fluid dynamics. We performed a 3-D steady computation and a complete set of 3-D quasisteady computations for a range of pectoral fin positions and surface velocities. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing was then used to compute the unsteady flow about the wrasse through several complete cycles of pectoral fin oscillation. The shape deformation of the pectoral fin throughout the oscillation was taken from the experimental kinematics. The pressure distribution on the body of the bird wrasse and its pectoral fins was computed and integrated to give body and fin forces which were decomposed into lift and thrust. The velocity field variation on the surface of the wrasse body, on the pectoral fins and in the near-wake was computed throughout the swimming cycle. We compared our computational results for the steady, quasi-steady and unsteady cases with the experimental data on axial and vertical acceleration obtained from the pectoral fin kinematics experiments. These comparisons show that steady state computations are incapable of describing the fluid dynamics of flapping fins. Quasi-steady state computations, with correct incorporation of

  11. Development of plate-fin heat exchanger for intermediate heat exchanger of high-temperature gas cooled reactor. Fabrication process, high-temperature strength and creep-fatigue life prediction of plate-fin structure made of Hastelloy X

    International Nuclear Information System (INIS)

    Mizokami, Yorikata; Igari, Toshihide; Nakashima, Keiichi; Kawashima, Fumiko; Sakakibara, Noriyuki; Kishikawa, Ryouji; Tanihira, Masanori

    2010-01-01

    The helium/helium heat exchanger (i.e., intermediate heat exchanger: IHX) of a high-temperature gas-cooled reactor (HTGR) system with nuclear heat applications is installed between a primary system and a secondary system. IHX is operated at the highest temperature of 950degC and has a high capacity of up to 600 MWt. A plate-fin-type heat exchanger is the most suitable for IHX to improve construction cost. The purpose of this study is to develop an ultrafine plate-fin-type heat exchanger with a finer pitch fin than a conventional technology. In the first step, fabrication conditions of the ultrafine plate fin were optimized by press tests. In the second step, a brazing material was selected from several candidates through brazing tests of rods, and brazing conditions were optimized for plate-fin structures. In the third step, tensile strength, creep rupture, fatigue, and creep-fatigue tests were performed as typical strength tests for plate-fin structures. The obtained data were compared with those of the base metal and plate-fin element fabricated from SUS316. Finally, the accuracy of the creep-fatigue life prediction using both the linear cumulative damage rule and the equivalent homogeneous solid method was confirmed through the evaluation of creep-fatigue test results of plate-fin structures. (author)

  12. Introduction of anti-rolling active vertical fin and its application to maneuverability for displacement-type super high speed ship. 2nd Report.; Haisuiryogata chokosokusen no yokoyure seishiyo active suichoku fin no donyu to sojuseieno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T; Saito, Y [Yokohama National University, Yokohama (Japan). Faculty of Engineering; Niihara, Y [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1997-12-31

    Discussed herein are the effects of vertical fin projecting downwards from the bottom of a displacement-type superhigh-speed ship, installed to improve its transverse stability and turning ability. The system for simultaneously controlling rudder and vertical fin by the optimum regulator was studied for maneuverability in directional following waves and smooth water, and maneuverability was simulated numerically. A ship is greatly rolled and sloped when running in waves. It is found that the vertical fin shows a high anti-rolling effect when the ship runs straight. The optimum regulator greatly improves maneuverability in waves, reducing rolling by 92%. Increased rolling with the vertical fin, observed in the previous study in directional following waves, is found to be due to the rudder. The optimum position of the fin is determined to control transverse sloping of a turning ship in a superhigh-speed region. 21 refs., 12 figs., 4 tabs.

  13. Introduction of anti-rolling active vertical fin and its application to maneuverability for displacement-type super high speed ship. 2nd Report.; Haisuiryogata chokosokusen no yokoyure seishiyo active suichoku fin no donyu to sojuseieno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T.; Saito, Y. [Yokohama National University, Yokohama (Japan). Faculty of Engineering; Niihara, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1996-12-31

    Discussed herein are the effects of vertical fin projecting downwards from the bottom of a displacement-type superhigh-speed ship, installed to improve its transverse stability and turning ability. The system for simultaneously controlling rudder and vertical fin by the optimum regulator was studied for maneuverability in directional following waves and smooth water, and maneuverability was simulated numerically. A ship is greatly rolled and sloped when running in waves. It is found that the vertical fin shows a high anti-rolling effect when the ship runs straight. The optimum regulator greatly improves maneuverability in waves, reducing rolling by 92%. Increased rolling with the vertical fin, observed in the previous study in directional following waves, is found to be due to the rudder. The optimum position of the fin is determined to control transverse sloping of a turning ship in a superhigh-speed region. 21 refs., 12 figs., 4 tabs.

  14. Evaluación e implantación de herramienta móvil para la asistencia de personas con necesidades especiales en sus tareas de la vida diaria

    OpenAIRE

    Torrado Vidal, Juan Carlos

    2014-01-01

    En este Trabajo de Fin de Máster se describe la evaluación de una herramienta basada en smartphone para asistir a personas con discapacidad cognitiva en sus tareas de la vida diaria, llamada AssisT-Task, cuyo diseño inicial fue objeto de Trabajo de Fin de Grado. Esta aplicación proporciona manuales interactivos paso a paso con instrucciones para completar tareas cotidianas en su entorno o centro de empleo, utilizando como apoyo códigos QR y una herramienta de autor para que los...

  15. The role of tip deflection on the thrust produced by rigid flapping fins

    Science.gov (United States)

    Huera-Huarte, Francisco; Gharib, Morteza

    2015-11-01

    It is well known that flexibility plays an important role in the propulsion performance and efficiency of oscillating fin based propulsion systems. Compliance is one of the aspects that has received more attention, as it seems to be a common feature in nature's flyers and swimmers. Active control strategies are also common in nature. We will show how by deflecting only the last 10% of length of a rigid fin, at the tip, the thrust can be changed dramatically. This can be thought as an alternative to passive flexibility for controlling very efficiently the momentum transfer in the wake and therefore the thrust generation when flapping. A series of experiments have been carried with a robotic fin that allowed the control of its flapping kinematics as well as the control of the motions of its tip independently. We will be showing situations in which the tip was kept at a certain fixed position during a power stroke, and others in which it moved either in-phase or out-of-phase with the fin. The observed thrust and wake dynamics will be discussed for all these situations. The authors would like to acknowledge the financial support provided by the Gordon and Betty Moore Foundation and by the Spanish Ministerio de Economia y competitividad (MINECO) through grant DPI2012-37904. Visiting Associate in Aerospace, California Institute of Technology.

  16. Synchronous seasonal change in fin whale song in the North Pacific.

    Directory of Open Access Journals (Sweden)

    Erin M Oleson

    Full Text Available Fin whale (Balaenoptera physalus song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus and humpback whales (Megaptera novaeangliae, these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here.

  17. Eric Clapton et Pete Postlethwaite sur la liste des honneurs de fin d'annee

    CERN Multimedia

    2003-01-01

    "Le guitariste Eric Clapton, l'acteur Pete Postlethwaite et l'un des peres de l'internet Tim Berners-Lee figurent, aux cotes du XV d'Angleterre, sur la liste de fin d'annee des principales personnalites distinguees par la reine Elizabeth II" (1/2 page).

  18. Design and dynamic modeling of electrorheological fluid-based variable-stiffness fin for robotic fish

    Science.gov (United States)

    Bazaz Behbahani, Sanaz; Tan, Xiaobo

    2017-08-01

    Fish actively control their stiffness in different swimming conditions. Inspired by such an adaptive behavior, in this paper we study the design, prototyping, and dynamic modeling of compact, tunable-stiffness fins for robotic fish, where electrorheological (ER) fluid serves as the enabling element. A multi-layer composite fin with an ER fluid core is prototyped and utilized to investigate the influence of electrical field on its performance. Hamilton's principle is used to derive the dynamic equations of motion of the flexible fin, and Lighthill's large-amplitude elongated-body theory is adopted to estimate the hydrodynamic force when the fin undergoes base-actuated rotation. The dynamic equations are then discretized using the finite element method, to obtain an approximate numerical solution. Experiments are conducted on the prototyped flexible ER fluid-filled beam for parameter identification and validation of the proposed model, and for examining the effectiveness of electrically controlled stiffness tuning. In particular, it is found that the natural frequency is increased by almost 40% when the applied electric field changes from 0 to 1.5× {10}6 {{V}} {{{m}}}-1.

  19. Effect of refrigerant mal-distribution in fin-and-tube evaporators on system performance

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Larsen, Lars Finn Sloth

    2009-01-01

    the condenser is a dynamic moving boundary model. The evaporator model is a dynamic distributed one-dimensional homogeneous equilibrium model, in order to capture the distribution phenomena. Fin-and-tube heat exchangers usually have a complex circuitry, however the evaporator will be simplified to be two...

  20. MEMS silicon-based micro-evaporator with diamond-shaped fins

    NARCIS (Netherlands)

    Mihailovic, M.; Rops, C.; Creemer, J.F.; Sarro, P.M.

    2010-01-01

    A new design of micro-evaporators, with 45 channels (100 μm deep) and diamond-shaped fins (40μm wide, 160μm long, 20μm separation), is fabricated by anodic bonding of silicon and glass wafers, in a five masks process. This new design improves stability of the working conditions, and has a localized

  1. Disturbance-specific social responses in long-finned pilot whales, Globicephala melas

    NARCIS (Netherlands)

    Visser, F.; Curé, C.; Kvadsheim, P.H.; Lam, F.P.A.; Tyack, P.L.; Miller, P.J.O.

    2016-01-01

    Social interactions among animals can influence their response to disturbance. We investigated responses of long-finned pilot whales to killer whale sound playbacks and two anthropogenic sources of disturbance: Tagging effort and naval sonar exposure. The acoustic scene and diving behaviour of

  2. Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA in Shark Fins

    Directory of Open Access Journals (Sweden)

    John Pablo

    2012-02-01

    Full Text Available Sharks are among the most threatened groups of marine species. Populations are declining globally to support the growing demand for shark fin soup. Sharks are known to bioaccumulate toxins that may pose health risks to consumers of shark products. The feeding habits of sharks are varied, including fish, mammals, crustaceans and plankton. The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA has been detected in species of free-living marine cyanobacteria and may bioaccumulate in the marine food web. In this study, we sampled fin clips from seven different species of sharks in South Florida to survey the occurrence of BMAA using HPLC-FD and Triple Quadrupole LC/MS/MS methods. BMAA was detected in the fins of all species examined with concentrations ranging from 144 to 1836 ng/mg wet weight. Since BMAA has been linked to neurodegenerative diseases, these results may have important relevance to human health. We suggest that consumption of shark fins may increase the risk for human exposure to the cyanobacterial neurotoxin BMAA.

  3. Exergo-economic analysis of finned tube for waste heat recovery including phase change heat transfer

    International Nuclear Information System (INIS)

    Wu, Shuang Ying; Jiu, Jing Rui; Xiao, Lan; Li, You Rong; Liu, Chao; Xu, Jin Liang

    2013-01-01

    In this paper, an exergo-economic criterion, i.e. the net profit per unit transferred heat load, is established from the perspective of exergy recovery to evaluate the performance of finned tube used in waste heat recovery. Also, the dimensionless exergy change number is introduced to investigate the effect of the flow (mechanical) exergy loss rate on the recovered thermal exergy. Selecting R245fa as a working fluid and exhaust flue gas as a heat source, the effects of the internal Reynolds number Re_i, the external Reynolds number Re_o , the unit cost of thermal exergy ε_q , the geometric parameter of finned tube η_oβ and the phase change temperature T_v etc. on the performance of finned tube are discussed in detail. The results show that the higher T_v and η_oβ, and lower Re_i may lead to the negligible flow(mechanical) exergy loss rate. There exists an optimal value of Re_i where the net profit per unit transferred heat load peaks, while the variations of Re_o, ε_q and T_v cause monotonic change of the net profit per unit transferred heat load. The phase change temperature exerts relatively greater influence on the exergo-economic performance of finned tube in comparison with other parameters. And there exists a critical phase change temperature, where the net profit per unit transferred heat load is equal to zero.

  4. Thermal performance analysis and optimum design parameters of heat exchanger having perforated pin fins

    International Nuclear Information System (INIS)

    Sahin, Bayram; Demir, Alparslan

    2008-01-01

    This paper reports the heat transfer enhancement and corresponding pressure drop over a flat surface equipped with circular cross section perforated pin fins in a rectangular channel. The channel had a cross section area of 100-250 mm 2 . The experiments covered the following ranges: Reynolds number 13500-42,000, clearance ratio (C/H) 0, 0.33 and 1 and interfin spacing ratio (S y /D) 1.208, 1.524, 1.944 and 3.417. Correlation equations were developed for the heat transfer, friction factor and enhancement efficiency. The experimental results showed that the use of circular cross section pin fins may lead to heat transfer enhancement. Enhancement efficiencies varied between 1.4 and 2.6 depending on clearance ratio and interfin spacing ratio. Using a Taguchi experimental design method, optimum design parameters and their levels were investigated. Nusselt number and friction factor were considered as performance parameters. An L 9 (3 3 ) orthogonal array was selected as an experimental plan. First of all, each goal was optimized separately. Then, all the goals were optimized together, considering the priority of the goals, and the optimum results were found to be Reynolds number of 42,000, fin height of 50 mm and streamwise distance between fins of 51 mm

  5. pour le trimestre qui a pris fin le 30 septembre 2016

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    30 sept. 2016 ... Le CRDI finance des travaux de recherche appliquée ... internationales dʼinformation financière (normes IFRS). ..... voie de développement et sur la mise en oeuvre des connaissances scientifiques, techniques et autres en vue du .... Les accords expirent à des dates différentes, et le dernier prend fin en.

  6. Rapport financier trimestriel pour le trimestre qui a pris fin le 31

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    31 déc. 2015 ... Le CRDI finance des travaux de recherche appliquée ... recherches pour le développement international (CRDI, le Centre) et ..... voie de développement et sur la mise en oeuvre des connaissances scientifiques, techniques et autres en .... Les accords expirent à des dates différentes, et le dernier prend fin.

  7. pour le trimestre qui a pris fin le 30 juin 2015

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    30 juin 2015 ... Le CRDI finance des travaux de recherche appliquée ... recherches pour le développement international (le Centre) et de ..... voie de développement et sur la mise en oeuvre des connaissances scientifiques, techniques et autres en .... Les accords expirent à des dates différentes, et le dernier prend fin en.

  8. pour le trimestre qui a pris fin le 31 décembre 2014

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    31 déc. 2014 ... Le CRDI finance des travaux de recherche appliquée ... recherches pour le développement international (le Centre) et de ...... voie de développement et sur la mise en oeuvre des connaissances scientifiques, techniques et autres en vue .... Les accords expirent à des dates différentes, et le dernier prend fin.

  9. Rapport financier trimestriel pour le trimestre qui a pris fin le 30

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    30 sept. 2015 ... Le CRDI finance des travaux de recherche appliquée ... recherches pour le développement international (le Centre) et de ..... voie de développement et sur la mise en oeuvre des connaissances scientifiques, techniques et autres en .... Les accords expirent à des dates différentes, et le dernier prend fin en.

  10. Genetic characterization of fin fish species from the Warri River at ...

    African Journals Online (AJOL)

    SAM

    2014-07-02

    Jul 2, 2014 ... Genetic characterization of fin fish species from the. Warri River at Ubeji, Niger Delta, Nigeria. Asagbra ..... Prochilodus lineatus, Salminus brasiliensis and Steindachneridion scripta) from Uruguay River basin. Brazilian Archives Biol. Tech. 49(4):589-598. Saad YM, Shaden-Hanafi M, Essa MA, Guerges AA ...

  11. Mitogenomic phylogenetics of fin whales (Balaenoptera physalus spp.) : Genetic evidence for revision of subspecies

    NARCIS (Netherlands)

    Archer, Frederick I.; Morin, Phillip A.; Hancock-Hanser, Brittany L.; Robertson, Kelly M.; Leslie, Matthew S.; Bérubé, Martine; Panigada, Simone; Taylor, Barbara L.

    2013-01-01

    There are three described subspecies of fin whales (Balaenoptera physalus): B. p. physalus Linnaeus, 1758 in the Northern Hemisphere, B. p. quoyi Fischer, 1829 in the Southern Hemisphere, and a recently described pygmy form, B. p. patachonica Burmeister, 1865. The discrete distribution in the North

  12. Rapport financier trimestriel pour le trimestre qui a pris fin le 30 juin ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Sophie Comeau

    30 juin 2017 ... Régi par la Loi sur le Centre de recherches pour le développement international ... des retombées; forme des leaders dans les secteurs de l'administration .... Au cours de la période de trois mois qui a pris fin le 30 juin 2017, ...

  13. Dolphin Morbillivirus in a Fin Whale (Balaenoptera physalus) in Denmark, 2016

    DEFF Research Database (Denmark)

    Jo, Wendy K.; Grilo, Miguel L.; Wohlsein, Peter

    2017-01-01

    We studied the etiology of encephalitis in a fin whale (Balaenoptera physalus) that stranded in 2016 on the coast of Denmark. Dolphin morbillivirus (DMV) was detected in the brain and other organs. Phylogenetics showed close relation to DMV isolated from a striped dolphin (Stenella coeruleoalba...

  14. Study on Fins' Effect of Boiling Flow in Millimeter Channel Heat Exchanger

    Science.gov (United States)

    Watanabe, Satoshi

    2005-11-01

    Recently, a lot of researches about compact heat exchangers with mini-channels have been carried out with the hope of obtaining a high-efficiency heat transfer, due to the higher ratio of surface area than existing heat exchangers. However, there are many uncertain phenomena in fields such as boiling flow in mini-channels. Thus, in order to understand the boiling flow in mini-channels to design high-efficiency heat exchangers, this work focused on the visualization measurement of boiling flow in a millimeter channel. A transparent acrylic channel (heat exchanger form), high-speed camera (2000 fps at 1024 x 1024 pixels), and halogen lamp (backup light) were used as the visualization system. The channel's depth is 2 mm, width is 30 mm, and length is 400 mm. In preparation for commercial use, two types of channels were experimented on: a fins type and a normal slit type (without fins). The fins are circular cylindrical obstacles (diameter is 5 mm) to promote heat transfer, set in a triangular array (distance between each center point is 10 mm). Especially in this work, boiling flow and heat transfer promotion in the millimeter channel heat exchanger with fins was evaluated using a high-speed camera.

  15. Thermal performance of a spirally coiled finned tube heat exchanger under wet-surface conditions

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Naphon, Paisarn

    2006-01-01

    This paper is a continuation of the author's previous work on spiral coil heat exchangers. In the present study, the heat transfer characteristics and the performance of a spirally coiled finned tube heat exchanger under wet-surface conditions are theoretically and experimentally investigated. The test section is a spiral-coil heat exchanger which consists of a steel shell and a spirally coiled tube unit. The spiral-coil unit consists of six layers of concentric spirally coiled finned tubes. Each tube is fabricated by bending a 9.6 mm diameter straight copper tube into a spiral-coil of four turns. The innermost and outermost diameters of each spiral-coil are 145.0 and 350.4 mm, respectively. Aluminium crimped spiral fins with thickness of 0.6 mm and outer diameter of 28.4 mm are placed around the tube. The edge of fin at the inner diameter is corrugated. Air and water are used as working fluids in shell side and tube side, respectively. The experiments are done under dehumidifying conditions. A mathematical model based on the conservation of mass and energy is developed to simulate the flow and heat transfer characteristics of working fluids flowing through the heat exchanger. The results obtained from the present model show reasonable agreement with the experimental data

  16. Oscillatory Adaptive Yaw-Plane Control of Biorobotic Autonomous Underwater Vehicles Using Pectoral-Like Fins

    Directory of Open Access Journals (Sweden)

    Mugdha S. Naik

    2007-01-01

    Full Text Available This article considers the control of a biorobotic autonomous underwater vehicle (BAUV in the yaw plane using biologically inspired oscillatory pectoral-like fins of marine animals. The fins are assumed to be oscillating harmonically with a combined linear (sway and angular (yaw motion producing unsteady forces, which are used for fish-like control of BAUVs. Manoeuvring of the BAUV in the yaw plane is accomplished by altering the bias (mean angle of the angular motion of the fin. For the derivation of the adaptive control system, it is assumed that the physical parameters, the hydrodynamic coefficients, and the fin force and moment are not known. A direct adaptive sampled-data control system for the trajectory control of the yaw-angle using only yaw-angle measurement is derived. The parameter adaptation law is based on the normalised gradient scheme. Simulation results for the set point control, sinusoidal trajectory tracking and turning manoeuvres are presented, which show that the control system accomplishes precise trajectory control in spite of the parameter uncertainties.

  17. Results of Monte-Carlo studies on backscattering and sputtering from 'pocket' and 'finned' structures

    International Nuclear Information System (INIS)

    Brown, K.P.

    1978-01-01

    A Monte-Carlo computer program which has been developed for studying backscattering and sputtering processes involving high energy particles in complex vacuum structures has been used to show that useful reductions in backscattering and sputtering can be achieved by pocketing or finning the wall surfaces of plasma containment vessels. (author)

  18. The relationship between the mercury concentration in fish muscles and scales/fins and its significance

    Czech Academy of Sciences Publication Activity Database

    Červenka, R.; Bednařík, A.; Komárek, J.; Ondračková, Markéta; Jurajda, Pavel; Vítek, T.; Spurný, P.

    2011-01-01

    Roč. 9, č. 6 (2011), s. 1109-1116 ISSN 1895-1066 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Mercury determination * Fish muscle * Scale * Fin Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 1.073, year: 2011

  19. Compensation of flow maldistribution in fin-and-tube evaporators for residential air-conditioning

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Brix, Wiebke; Elmegaard, Brian

    2011-01-01

    Compensation of flow maldistribution in multi-channel fin-and-tube evaporators for residential air-conditioning is investigated by numerical modeling. The considered sources of maldistribution are distribution of the liquid and vapor phases in the distributor and non-uniform airflow distribution....

  20. Liquid-metal pin-fin pressure drop by correlation in cross flow

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

    1994-01-01

    The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed