WorldWideScience

Sample records for se trata realmente

  1. Manejo de información: Cuando de rumores se trata.

    Directory of Open Access Journals (Sweden)

    Alejandro Querejeta

    2008-09-01

    Full Text Available Inicia con varias acepciones sobre el rumor. Enfatiza en que nunca se debería publicar un rumor, primero hay que confirmar, confrontar y valorar. Los rumores no son noticia pueden ser considerados como datos disparadores para iniciar una investigación. Otro autor señala que el periodista debería "analizar el rumor base, diseccionarlo, sazonarlo con lógica y conocimientos y definir el campo de investigación". La práctica del rumor socava el buen periodismo y puede hacer vivir costosas crisis de credibilidad de graves consecuencias.

  2. Economia social, economia solidária, terceiro setor: do que se trata?

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    Lechat, Noëlle Marie Paule

    2002-01-01

    Full Text Available A partir da segunda metade da década de 90, aparece na literatura acadêmica brasileira uma série de novas categorias que poderiámos agrupar sob as apelações de "terceiro setor" e "economia solidária". A pesquisa concentra-se na segunda categoria e tem por objetovo identificar sua origem e a realidade que ela pretende abranger. Neste texto são expostas algumas definições que podem ser encontradas na literatura internacional a respeito de termos como economia social, economia solidária, terceiro setor e outros mais. Deste confronto aparece que os conceitos utilizados no Brasil para estudar o campo da economia solidária tendem a uma certa estreiteza devido à pouca ênfase sobre questões como o resgate histórico anterior aos anos 80, a pluralidade ideológica e o hibridismo econômico, porém demonstram sensibilidade quanto à construção de uma outra cultura econômica de mercado, economia estatal e economia de reciprocidade que a categoria de terceiro setor tende a mascarar. Em vista disto, constata-se a necessidade de repensar esta categoria e de questionar as grandes expectativas assentadas na for mação de uma economia solidária para a transformação da sociedade

  3. Sustantivos que plantean dudas sobre su formación en femenino cuando se trata de profesiones, títulos y actividades

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    GLORIA SMITH AVENDAÑO DE BARÓN

    2012-01-01

    Full Text Available Este artículo recoge los resultados de un trabajo de investigación enmarcado en el campo de la Lingüística. A partir de un corpus de sustantivos con formación en femenino, se presenta un análisis razonado y contrastado desde el punto de vista gramatical. Se argumenta a favor del uso de este tipo de sustantivos con base en las distintas posiciones, tanto de la Real Academia Española (RAE como de otros estudios de gramática, pero haciendo compatible lo propio de la norma culta con los registros de uso extendido, regional, coloquial y la presencia en documentos: textos literarios, periodísticos y científicos.

  4. Lactancia materna exclusiva: ¿la conocen las madres realmente?

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    Yeis Miguel Borre Ortiz

    2014-11-01

    Full Text Available Introducción: La Organización Mundial de la Salud declara que la lactancia materna es un hábito ligado íntimamente a la supervivencia de la especie humana desde tiempo inmemorial. A nivel mundial, únicamente el 35% de los bebés son amamantados durante sus primeros cuatro meses de vida. La literatura evidencia que aún existen madres que desconocen su importancia. Por ello, el objetivo del presente estudio fue identificar si las madres de una localidad determinada de Santa Marta, conocían los beneficios y consecuencias de la lactancia materna exclusiva. Materiales y Métodos: Estudio descriptivo, transversal, cuantitativo, en el que se encuestaron 90 madres que acudieron al Centro de Salud 11 de Noviembre de Santa Marta (Colombia; seleccionadas por muestreo intencional, no probabilístico. Se preservaron aspectos éticos y metodológicos que dieran cuenta del rigor científico correspondiente. Resultados: De las 90 madres encuestadas, el 51% tiene edades entre 15 a 25 años, el 30% entre 26 a 35 años, y el 19% son mayores de 35 años. El 85.6% posee conocimientos adecuados sobre lactancia materna exclusiva. El 48.9% conoce la técnica de amamantamiento adecuada, mientras que el 51.1% restante no tiene idea de ello. Discusión: Los resultados del presente estudio guardan relación con estudios similares realizados a nivel nacional e internacional, los cuales muestran que aunque la LM es un factor fundamental para el adecuado desarrollo de la primera infancia, infancia y adolescencia, requiere que las madres estén más educadas y mejor informadas. Conclusiones: Las madres continúan mostrando altos índices de desinformación con respecto a la lactancia materna. Por tanto, se necesita el desarrollo y establecimiento de programas de educación, que permitan educar a esta población y a futuras madres lactantes; específicamente, a primigestantes y adolescentes.Palabras clave: Lactancia Materna, Madres, Conocimiento. (Fuente: DeCS BIREME

  5. DOLARIZAR:: ¿REALMENTE UN DILEMA?

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    Beethoven Herrera V

    Full Text Available Este trabajo presenta el debate teórico actual en torno a las ventajas y desventajas, costos y beneficios, de adoptar los diversos regímenes cambiarios, en especial el de régimen es cambiarios ultrafijos como la dolarización, en el actual escenario de crisis financiera internacional y de inestabilidad macroeconómica de América Latina. Luego se contrastan las diferentes propuestas teóricas con la evidencia empírica del desempeño económico de los países que operan bajo regímenes cambiarios cercanos a la dolarización, y finalmente, ofrece algunas conclusiones.This paper analyses the present theoretical debate on the advantages and disadvantages, costs and benefits referred to the adoption of different foreign exchange regimes, and sp¿cially the ul tra-fix ones such as the dollarization in the present si tuation of international financial crisis and saec roeconomi:c instability in Latin America. Further on different theoretical propositions are contrasted with empir.ícal evidence of the economic performance of those countries that operate under foreign trade regimes close to dollarization, and finally, is otfers some conclusions.

  6. Trata de Personas: un déficit de trabajo decente

    OpenAIRE

    Jakeline Vargas Parra; Lya Fernández de Mantilla

    2013-01-01

    La búsqueda de situaciones de explotación en las resoluciones de la Dirección Territorial Santander del Ministerio de Trabajo que se aproximaran a las modalidades de trata de personas, permitió iniciar un análisis de la brecha existente entre el abordaje de la trata de personas, el mercado laboral y la protección social. Las violaciones a la legislación laboral identificadas, si bien no constituyen trata de personas, sí reflejan un déficit de trabajo decente en la estructura del mercado labor...

  7. La trata de personas en la modalidad de trabajo infantil

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    Angélica García Marbella

    2017-01-01

    Full Text Available En este trabajo se describen las causas y el proceso evolutivo del trabajo infantil en México; sin embargo, en la exposición se retoman elementos que identifican el problema en el contexto mundial. En ese sentido, se destaca que durante algún tiempo el quehacer de los infantes en el mercado de trabajo era considerado como un medio para que aprendieran determinado oficio, así como que dicha connotación no ha dejado de existir, pero ahora coexiste con otras tendencias asociadas a la delincuencia organizada, tales como prostitución, pornografía y turismo infantil; es decir, con actividades vinculadas estrechamente con la trata de personas. La pretensión es evidenciar el problema y las principales prácticas de quienes llevan a cabo dicho comportamiento; por lo que hubo necesidad de recurrir a la aplicación de una entrevista focalizada, basada en ocho informantes, con la finalidad de conocer la percepción de personas involucradas en dicha problemática. Al final del trabajo, lo observado es que la problemática en cuestión sigue creciendo en México; situación que es corroborada por los datos que aportan diversas instituciones, que señalan que en la actualidad este país ocupa el primer lugar en dicho comportamiento.

  8. La posible segurizaci?n de la trata de personas en el hemisferio Americano

    OpenAIRE

    Benito Cuellas, Joanna Milena

    2004-01-01

    La trata de personas, se ha identificado como un problema creciente a nivel global, construy?ndose como la tercera actividad delictiva m?s lucrativa, despu?s del tr?fico de drogas y armas respectivamente, generando entre 7000 y 10000 millones de d?lares anuales

  9. La trata de mujeres de Europa del Este con fines de explotación sexual en el Reino Unido

    OpenAIRE

    Bryl, Kateryna

    2016-01-01

    Actas del I Congreso de jóvenes investigadorxs con perspectiva de género (Getafe, 16 y 17 de junio de 2016) organizado por el Instituto Universitario de Estudios de Género de la Universidad Carlos III de Madrid. La trata de mujeres con fines de explotación sexual se considera la forma más rentable de la trata de personas, ya que las mujeres, como un bien, pueden ser vendidas y utilizadas muchas veces, a diferencia de, por ejemplo, la trata para la extracción de órganos, porque no se puede ...

  10. CLIENTES DE PROSTITUCIÓN: REPRESENTACIONES SOCIALES DE TRATA DE PERSONAS

    OpenAIRE

    Luis, Anel Hortensia Gómez San; Avendaño, Ariagor Manuel

    2015-01-01

    Se reportan los hallazgos de una investigación realizada en la comunidad de La Merced de la Ciudad de México, donde la trata y la explotación sexual comercial se conjugan para victimizar a niñas, adolescentes y adultas, ante una comunidad pasiva, y la participación activa de clientes de prostitución, quienes no suelen cuestionar el proceso que las llevó a estar inmersas en el comercio sexual. El análisis de las entrevistas realizadas a hombres que se identificaron como clientes de prostitució...

  11. CLIENTES DE PROSTITUCIÓN: REPRESENTACIONES SOCIALES DE TRATA DE PERSONAS

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    Anel Hortensia Gómez San Luis

    2015-08-01

    Full Text Available Se reportan los hallazgos de una investigación realizada en la comunidad de La Merced de la Ciudad de México, donde la trata y la explotación sexual comercial se conjugan para victimizar a niñas, adolescentes y adultas, ante una comunidad pasiva, y la participación activa de clientes de prostitución, quienes no suelen cuestionar el proceso que las llevó a estar inmersas en el comercio sexual. El análisis de las entrevistas realizadas a hombres que se identificaron como clientes de prostitución, muestra en su representación social la existencia de elementos que dan cuenta de la trata y explotación sexual de mujeres prostituidas, sin embargo, no reconocen su participación en el delito, al utilizar a mujeres que han sido víctimas de trata con fines de explotación sexual.

  12. Poblaciones-Mercancía: Tráfico y trata de mujeres en España

    OpenAIRE

    García Cuesta, Sara; López Sala, Ana María; Hernández Corrochano, Elena; Mena Martínez, Luis

    2011-01-01

    Se trata de la primera publicación que hace la Delegación del Gobierno para la Violencia de Género a fin de ahondar en el fenómeno de la Trata de Seres Humanos con fines de explotación sexual. El estudio refleja la situación en España de las mujeres que han sido víctimas del tráfico y de la trata de seres humanos con fines de explotación sexual, trazando de manera firme la diferencia entre tráfico de personas y trata de mujeres con fines de explotación sexual.

  13. It's Not About American Football: Tony Dungy's Journey of Self-Emancipation from Rejected Black Quarterback to Celebrated African American Coach (No se trata de fútbol americano: la emancipación de Tony Dungy, de marginado quarterback negro a célebre

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    James R. Zimmerman

    2015-06-01

    Full Text Available Abstract: The ideals of individual freedom and universal equality contrast with the persistence of oppression and inequality worldwide, making every case study of practical progress toward freedom and equality valuable. The example of Coach Tony Dungy, the first African American to lead a Super Bowl championship team, is an instance of incremental self-emancipation. Dungy's competitive nature shows up in everything he writes and says, but his emphasis on commitment to self-improvement and community-building illustrates the possibilities of individual and collective progress. Dungy's narrative, seen in the context of Jacques Ranciere's theoretical approach, is an instructive example of "intellectual equality." Ranciere insists that we are all intellectual equals, and Dungy's autobiographical writing exemplifies a pragmatic application of this attitude, which also suggests a theoretical and practical approach to the development of community through a process of dedicated self-emancipation.Resumen: Los ideales de la libertad individual e igualdad universal contrastan con la persistencia de la opresión y desigualdad mundial, y por lo tanto cada estudio hacia la libertad y la igualdad se hace valioso. El ejemplo del entrenador de fútbol americano Tony Dungy, el primer afroamericano en entrenar un equipo que ganó la Super Bowl, es un ejemplo de auto-emancipación gradual. La naturaleza competitiva de Dungy está presente en todo lo que él escribe y dice, pero el énfasis otorgada a su compromiso con la autosuperación y la creación de comunidad ilustran las posibilidades del progreso tanto a nivel individual como colectivo. La narrativa de Dungy, vista en el contexto del enfoque teórico de Jacques Ranciere, es un ejemplo didáctico de "igualdad intelectual." Ranciere insiste en que todos poseemos igualdad de intelecto y la escritura autobiográfica de Dungy ejemplifica una aplicación pragmática de esta actitud, la cual sugiere un enfoque te

  14. Prostitución y trata de mujeres con fines de explotación sexual

    OpenAIRE

    Morales Plaza, Eva María

    2011-01-01

    [ES]Este estudio se centra en la explotación de la prostitución de una persona, ya sea como forma de supervivencia por una situación completamente precaria o por la explotación a través de la trata de personas. [EN] This study focuses on the exploitation of prostitution of a person, whether as a survival strategy for an entirely precarious or exploitation through trafficking. Trabajo de Fin de Máster del Máster en Estudios Interdisciplinares de Género, curso 2010-2011.

  15. Trata de mujeres con fines de explotación sexual en Tlaxcala

    OpenAIRE

    Martínez de Ita, María Eugenia; Hernández Gutiérrez, Regina Isabel

    2014-01-01

    La trata de personas es un problema que ha cobrado magnitud mundial, cuyas expresiones podemos encontrarlas en el ámbito local. Este es el caso que sucede en Tlaxcala, una de las entidades más pequeñas de México, que se ha destacado porque de aquí han emergido redes que explotan mujeres en todo el país y fuera del mismo, siendo la modalidad de explotación sexual la más común. El grupo más vulnerado en cuanto a explotación sexual corresponde a las mujeres, quienes son convertidas e...

  16. Trata de personas con fines de explotación sexual y papel del Trabajador/a Social

    OpenAIRE

    Coterillo García, Ainhoa

    2016-01-01

    La trata de personas con fines de explotación sexual es un fenómeno poco visible en nuestra sociedad, que supone graves dificultades a nivel biopsicosocial para las personas que lo sufren. Para la superación de estas dificultades y propiciar su inclusión en la sociedad, es necesario que exista una intervención integral y de calidad desde el Trabajo Social. En el presente Trabajo de Fin de Grado se pretende conocer la realidad que rodea la trata de personas con fines de explotación sexual....

  17. ¿Comprendemos realmente el significado del ALCA?

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    Orlando Zelaya Martínez; Luis Murillo Orozco

    2004-01-01

    Después de finalizada la segunda guerra mundial, Estados Unidos se convierte en el gendarme del mundo tanto en lo económico como en lo político, razón por cual decide no únicamente convertirse en el banquero del mundo, sino en su salvador ante el potencial peligro que representaba el comunismo como sistema. De esta forma crea un nuevo tipo de guerra de intensidad en el enfrentamiento directo, pero trasladando tal circunstancia al campo de la amenaza nuclear. Nos estamos refiriendo a la "Guerr...

  18. ¿Comprendemos realmente el significado del ALCA?

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    Orlando Zelaya Martínez

    2004-06-01

    Full Text Available Después de finalizada la segunda guerra mundial, Estados Unidos se convierte en el gendarme del mundo tanto en lo económico como en lo político, razón por cual decide no únicamente convertirse en el banquero del mundo, sino en su salvador ante el potencial peligro que representaba el comunismo como sistema. De esta forma crea un nuevo tipo de guerra de intensidad en el enfrentamiento directo, pero trasladando tal circunstancia al campo de la amenaza nuclear. Nos estamos refiriendo a la "Guerra Fría": el incentivo para que las dos nuevas potencias militares del mundo desarrollen una infraestructura de industria pesada bélica.

  19. Aspectos conceptuales sobre la trata de personas y el tráfico ilícito de migrantes y su trascendencia en la agenda internacional migratoria

    OpenAIRE

    Tapia Vivas, Gianina

    2014-01-01

    Con la dación de la Ley 29850, publicada el 16 de enero del 2007, Ley que reprime la trata de personas y el tráfico ilícito de migrantes, se define el concepto de trata. Dicho concepto surge a partir de la firma del Protocolo para Prevenir, Reprimir y Sancionar la Trata de Personas Especialmente Mujeres y Niños, que complementa la Convención de las Naciones Unidas contra la Delincuencia Organizada Transnacional. Por tal motivo, existe una motivación para realizar el presente ensayo, a fin de ...

  20. ¿Realmente sabemos lo que hacemos cuando creemos combatir la delincuencia?

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    David Coronado

    2006-01-01

    Full Text Available Este artículo trata el tema de las percepciones de la delincuencia que han sido formadas por los habitantes de dos zonas urbanas de la ciudad de Guadalajara, México: el barrio de Analco y la colonia Providencia. Las percepciones son definidas como una construcción social que propicia las configuraciones subjetivas con las que los sujetos se apropian de las vivencias cotidianas y la manera como seleccionan las posibles interpretaciones. Esta definición relaciona a las percepciones con las sensaciones y los sentidos, pero también con un entramado que se puede llamar red, esquema o ejemplar- de símbolos, sentidos y significados, que les ayudan a actuar en y con el mundo. La propia construcción de las percepciones otorga elementos para eslabonarlas con situaciones de vital importancia para los sujetos: descripciones espacio-temporales del mundo, evaluaciones cotidianas de las situaciones y, especialmente, con los aspectos prescriptivos de la vida. En el sentido arriba descrito, las percepciones están incluidas dentro de los procesos de cognición social, ubicados espacio-temporalmente, en tanto que dependen de los sentidos de los sujetos para captar la realidad y de los conocimientos previos. Esto es lo que da piso para hablar de la subjetividad, de la racionalidad y de las creencias.

  1. FORMAS CONTEMPORÁNEAS DE ESCLAVITUD: TRATA DE MUJERES

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    Waldimeiry Correa da Silva

    2013-10-01

    Full Text Available Afirma-se que o Tráfico de seres humanos é una forma contemporânea de escravidão, com base em que fundamento? Que elementos caracterizam o tráfico como escravidão contemporânea? Por outro lado, se o Tráfico é uma forma contemporânea de escravidão, temos de reconhecer a existência de uma prática que foi objeto de “proibição”, “abolição”, há mais de 150 anos: a escravidão. Uma prática condenada por diversas normas internacionais, tanto a nível universal quanto regional e nacional. Diante da inegável existência de formas contemporâneas de escravidão no cenário internacional, nos preguntamos se este fato não seria um exemplo da desordem internacional, produzida pela ausência de ação (ou baixa eficácia do ator principal para sua erradicação: o Estado. A estes efeitos, para a presente investigação, partimos da hipótese de que o Tráfico de seres humanos é um exemplo manifesto da desordem internacional. Para fundamentar nossa hipótese, a presente tese se encontra estruturada em quatro partes que guardam devida relação entre si. Na primeira, realizamos una análise teórica das Relaciones internacionais, no marco de nosso estudo: o Tráfico de mulheres como forma contemporânea de escravidão, um exemplo da desordem internacional. Esta análise está fundamentada, tanto desde a perspectiva construtivista das relações internacionais, com uma aproximação à teoria dos regímenes internacionais, quanto desde a humanização do Direito internacional contemporâneo. Na segunda, desenvolvemos o conceito de escravidão, suas formas análogas e do trabalho forçado. Na terceira, aprofundamos a análise no Tráfico de seres humanos, particularmente no tráfico de mulheres para fins de exploração sexual, no qual examinamos a evolução conceitual e as sinergias com outras formas contemporâneas de escravidão; sua manifestação como uma forma de violência contra a mulher e uma violação sistemática de

  2. Mujeres subsaharianas posibles víctimas de trata. Derecho a la salud en tránsito

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    Nuria Cordero Ramos

    2016-07-01

    Full Text Available En este artículo se abordan los problemas de salud integral derivados de la violencia de género a la que se ven sometidas las mujeres subsaharianas próximas a redes de trata, que cruzan fronteras y que se encuentran en Andalucía (España demandando servicios de salud. Así mismo, se analizan las dificultades con las que se encuentran éstas para ejercer su derecho a la salud en Andalucía, como lugar de tránsito, y las barreras que presentan los profesionales, condicionando su capacidad de intervención. El objetivo es fomentar la sensibilización y capacitación de los profesionales para favorecer la proximidad de los servicios sanitarios públicos en Andalucía a este colectivo.

  3. Programa bolsa família: a condicionante saúde realmente existe?

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    Núbia Maria Uchôa Barbosa

    2014-12-01

    saúde dos jovens. Esses são os novos marcos ético-legais que devem nortear as políticas nacionais de atenção à saúde dos jovens no Sistema Único de Saúde(7. Diante desse contexto, pergunta-se: os beneficiários do Programa Bolsa Família têm conhecimento sobre a condicionante saúde? A saúde pública tem conhecimentosobre a importância dessa condicionante para a nossa população jovem? Acreditamos que a condicionante saúde existe, mas, infelizmente, muito aquém do que realmente a nossa população merece e necessita.

  4. Las políticas públicas contra la trata de personas con fines de explotación sexual en tiempos del capitalismo global : Un análisis crítico de los elementos de identificación de situaciones de trata de personas en el sector aeroportuario

    OpenAIRE

    Moreno, Magdalena

    2017-01-01

    El presente trabajo tiene por objeto realizar un estudio introductorio sobre las políticas públicas sobre la trata de personas en relación a las prácticas migratorias, en Argentina en el período actual. El escrito tiene cinco apartados. En el primero, se realiza una mención, desde una perspectiva de género, a las características de la etapa global del capitalismo, a modo de contexto del proceso de feminización de las migraciones y del desarrollo global de la campaña anti-trata. Luego, se llev...

  5. SE PREVENINDO?

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    Ana Débora Assis Moura

    2010-01-01

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

  6. Estudio nacional exploratorio descriptivo sobre el fenómeno de trata de personas en Colombia.

    OpenAIRE

    2009-01-01

    Para el Ministerio del Interior y de Justicia como Secretaría Técnica del Comité Interinstitucional para la lucha contra la Trata de Personas y para la Oficina de Naciones Unidas contra la Droga y el Delito en Colombia UNODC, es un honor presentar a ustedes en esta oportunidad el primer Estudio Nacional Exploratorio Descriptivo sobre el Fenómeno de la Trata de Personas en Colombia, desarrollado por unequipo de Investigadoras e Investigadores de la Escuela de Estudios de Género de la Universid...

  7. La trata de mujeres con fines de explotación sexual : la globalización de la violencia de género

    OpenAIRE

    Casado Caballero, Vanessa

    2011-01-01

    La trata con fines de explotación sexual se ha convertido en la esclavitud del siglo XXI. La misma afecta fundamentalmente a millones de mujeres, niñas y niños y sus dimensiones de género son incuestionables. En este sentido, la explotación sexual del ser humano se puede producir a través de diversos mecanismos, de los que se pueden destacar entre otros, la pornografía, el matrimonio forzado, la esclavitud sexual, los espectáculos eróticos y sobre todo la prostitución. Es decir: la mayor part...

  8. La trata de mujeres como expresión internacional de la violencia de género

    OpenAIRE

    García Pedriz, Micaela Belén

    2017-01-01

    La trata de mujeres no es una problemática reciente, sino que es un fenómeno que ha ido evolucionando a lo largo de los años y que ha estado unido desde sus orígenes a la esclavitud y a la consideración de la mujer como objeto de satisfacción sexual, perdiendo las mujeres su condición de seres humanos. Por lo que el interrogante que se nos plantea es la razón de que en pleno siglo XXI, todavía continúe la violencia, el engaño, la cosificación; en sí la explotación de las mujeres con fines sex...

  9. La explotación sexual y las políticas de lucha contra la trata de seres humanos en España y Europa

    OpenAIRE

    López Villanueva, Enrique; Jornada sobre el tràfic d'éssers humans com a fenomen transnacional (2016:Mollet del Vallès)

    2016-01-01

    La trata de seres humanos, históricamente hablando, está vinculada a la esclavitud, al comercio esclavista y al tráfico ilegal de personas. La esclavitud es tan antigua como lo son las primeras civilizaciones, de hecho se conocen documentos históricos que datan de la antigua Mesopotamia. Esta ponencia explica el marco legal existente a Europa y España.

  10. Monitoreo de la Temperatura durante la Anestesia: ¿Es realmente necesario?

    Directory of Open Access Journals (Sweden)

    Lincoln de Parte Pérez

    Full Text Available La temperatura corporal debe ser monitoreada en todos los pacientes a los que se les realiza procedimientos quirúrgicos con el objetivo de detectar precozmente sus variaciones, así como las complicaciones que se presentan con las variaciones de esta, como son: fiebre, hipertermia maligna e hipotermia accidental y para el monitoreo de la hipertermia inducida. Se muestra una revisión de los factores que producen hipotermia durante el transoperatorio, así como la prevención y tratamiento de ella.

  11. Trayectorias y ciclos de explotación sexual y trata para la explotación sexual de mujeres en la Amazonía peruana

    OpenAIRE

    Jaris Mujica

    2014-01-01

    La explotación sexual comercial es una actividad constante y extendida en varias partes del Amazonía peruana. en los alrededores del puerto fluvial de Pucallpa, en la región Ucayali, esa práctica aparece sistemáticamente: las adolescentes que atienden las precarias tabernas alrededor del puerto y aquellas dedicadas a las labores de cocina en los campamentos madereros son víctimas de explotación constante, y muchas de ellas también de trata de personas. este artículo se dirige a reconstruir la...

  12. La trata de seres humanos con fines de explotación sexual: propuestas para un cambio de paradigma en la orientación de las políticas públicas

    OpenAIRE

    Nuño Gómez, Laura

    2017-01-01

    En la gran mayoría de las naciones del mundo la trata con fines de explotación sexual está tipificada y castigada por la legislación penal, pese a ello se estima que entre 1,3 y 4,4 millones mujeres y niñas permanecen explotadas por las redes crimina

  13. Monitoreo de la Temperatura durante la Anestesia: ¿Es realmente necesario?

    Directory of Open Access Journals (Sweden)

    Lincoln de Parte Pérez

    2003-04-01

    Full Text Available La temperatura corporal debe ser monitoreada en todos los pacientes a los que se les realiza procedimientos quirúrgicos con el objetivo de detectar precozmente sus variaciones, así como las complicaciones que se presentan con las variaciones de esta, como son: fiebre, hipertermia maligna e hipotermia accidental y para el monitoreo de la hipertermia inducida. Se muestra una revisión de los factores que producen hipotermia durante el transoperatorio, así como la prevención y tratamiento de ella.Body temperature should be monitored in all patients undergoing surgical procedures in order to detect its variations early, as well as the complications appearing with them, such as malignant hyperthermia and accidental hypothermia and for monitoring induced hyperthermia. A review of the factors producing hypothermia during the transoperative is made. Its prevention and treatment are also dealth with.

  14. Revisar Ley contra la Trata de Personas y Creación de la Coalición Nacional contra el Tráfico Ilícito de Migrantes y Trata de Personas, desde el enfoque de Derechos Humanos

    OpenAIRE

    Artavia Campos, Silvia Elena

    2014-01-01

    Esta investigación cualitativa, de tipo normal y socio-jurídica, se toma como base el análisis de la Ley 9095, Ley contra la Trata de Personas y Creación de la Coalición Nacional contra el Tráfico Ilícito de Migrantes y Trata de Personas, publicada en el año 2013, a la luz de los derechos promulgados en la Declaración Universal de Derechos Humanos. Además aprovecho mi experiencia profesional, durante la realización de la presente investigación, mi trabajo consiste en la atención integral d...

  15. Dificultades en la investigación preparatoria en delitos de trata de personas por explotación sexual de menores en la ciudad de Iquitos durante los años 2013 y 2014.

    OpenAIRE

    Vegas Pérez, María Luisa

    2016-01-01

    Problema: ¿Cuáles son las dificultades en la Investigación Preparatoria en Delitos de Trata de Personas por Explotación Sexual de menores en la ciudad de Iquitos durante los años 2013 y 2014? Objetivo: Identificar las dificultades en la investigación preparatoria en Delitos de Trata de Personas por Explotación Sexual de menores en la ciudad de Iquitos durante los años 2013 y 2014. Material y método: Se aplicó un cuestionario estructurado a una muestra de 500 sujetos, previa ...

  16. Trayectorias y ciclos de explotación sexual y trata para la explotación sexual de mujeres en la Amazonía peruana

    Directory of Open Access Journals (Sweden)

    Jaris Mujica

    2014-01-01

    Full Text Available La explotación sexual comercial es una actividad constante y extendida en varias partes del Amazonía peruana. en los alrededores del puerto fluvial de Pucallpa, en la región Ucayali, esa práctica aparece sistemáticamente: las adolescentes que atienden las precarias tabernas alrededor del puerto y aquellas dedicadas a las labores de cocina en los campamentos madereros son víctimas de explotación constante, y muchas de ellas también de trata de personas. este artículo se dirige a reconstruir la trayectoria de vida y el ciclo de reproducción de las formas de explotación en una muestra de veinte mujeres, y se concentra en: (i la evidencia de formas de explotación estacionales; (ii la trayectoria de vida de estas mujeres que muestra pasos en una cadena de explotación de varias etapas y en diferentes áreas de trabajo; (iii en ese contexto, la explotación sexual y la trata parecen no ser fenómenos permanentes sino estar concentrados en un momento de la trayectoria y detenerse con la maternidad, entre los 19 y 25 años, y (iv con la maternidad y el asentamiento matrilocal, las hijas e hijos repiten el ciclo y reproducen la cadena.

  17. Las paradojas del tráfico y la trata de mujeres de la Amazonía brasileña en España

    OpenAIRE

    Oliveira Marcia, Maria

    2011-01-01

    En la actualidad, según informes de la Organización Internacional del Trabajo, un 55% de las víctimas de la trata de personas en el mundo está constituido por mujeres, objetos de la explotación sexual comercial. El Brasil se presenta entre los principales países de origen, mientras que la Amazonía brasileña es la región con mayor cantidad de víctimas y rutas del tráfico internacional de mujeres. Los estudios apuntan que gran cantidad de estas mujeres llegan a España donde se encuentran los pr...

  18. Cada lengua en su olfato: ¿Es realmente torpe el hombre nombrando olores?

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    Benamí Barros García

    2015-03-01

    Full Text Available Probemos a decir a qué huele la carne cruda o cómo es algo que huele a viejo. Se ha asumido durante mucho tiempo que el ser humano es torpe nombrando olores y expresando sus cualidades abstractas. Recientes estudios sobre el jahai y el maniq, lenguas habladas por pequeñas comunidades del sudeste asiático, ponen en duda la inefabilidad de los olores como característica universal, a la vez que podrían aportar ideas en el estudio de los mecanismos de la percepción en su relación con el lenguaje.

  19. Aprendiendo sin prestar atención: ¿Qué aprendemos realmente?

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    Ruth de Diego-Balaguer

    2017-11-01

    Full Text Available En una nueva lengua, aprender palabras es más fácil que aprender las reglas que las combinan. ¿Las aprenderemos mejor si nos focalizamos más en ellas? Mediante un paradigma artificial de aprendizaje de reglas creamos distintas condiciones de forma que hubiese reglas más atendidas que otras. Los resultados mostraron que la atención no afecta al aprendizaje implícito (automático de las reglas, pero el conocimiento explícito (más consciente sí difiere en función de la cantidad de atención prestada. La atención potencia la adquisición de un conocimiento más específico sobre la regla, aunque el conocimiento más abstracto sobre el orden de las palabras se aprende independientemente de la atención prestada.

  20. La protección internacional de los refugiados víctimas de trata de personas

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    Shirley Llain Arenilla

    2014-01-01

    Full Text Available En el delito de trata de personas, la víctima, con miras a ser explotada por un tercero, es obligada o engañada para trasladarla a un lugar diferente al de su origen, bien sea a nivel interno o internacional. En este último caso, de acuerdo con los instrumentos internacionales en la materia, las víctimas del mencionado delito pueden llegar a ser sujetos de protección por el Estado receptor mediante la figura del refugio. En ese orden de ideas, con esta inves - tigación nos proponemos, en primer lugar, analizar la concepción del refugio en la actualidad y la ubicación del delito de trata a nivel trasnacional y, en segundo lugar, revisar la situación del cuestionamiento que respecto de su estatus migratorio sufren quienes siendo víctimas de trata solicitan refugio.

  1. El proceso de estructuración de mecanismos de cooperación bilateral : consideraciones para la lucha contra la trata de personas a partir del caso peruano-ecuatoriano

    OpenAIRE

    Galdos Frisancho, Melina Alejandra

    2016-01-01

    En la última década, el Perú ha respondido a las demandas del Régimen Internacional contra la Trata de Personas a través del diseño e implementación de medidas para prevenir, reprimir y sancionar este delito y sus formas de explotación. Dentro de este marco, Ecuador, a diferencia del resto de países de vecinos, se ha convertido en el país con el que más se ha avanzado en lo que respecta a la construcción de una agenda bilateral contra la trata de personas. Esta agenda común no parecería respo...

  2. Análisis del proceso que condujo a la construcción del concepto de explotación inserto en el Protocolo para prevenir, reprimir y sancionar la trata de personas, incorporado a la legislación colombiana a través de la Ley 800 de 2003

    OpenAIRE

    González Marín, Laura Lucía

    2012-01-01

    El objetivo de este trabajo de grado es describir una disputa política por el significado del concepto de explotación en el marco de la redacción del “Protocolo para prevenir, reprimir y sancionar la trata de personas, especialmente mujeres y niños”, en el cual se define aquello que se entiende por trata de personas. La construcción de este concepto excluye e invisibiliza otros tipos de explotación comunes en el sistema de producción capitalista contemporánea que pertenecen al universo de vio...

  3. La trata de personas con fines de explotación sexual en España: elementos para la reflexión

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    Belén Blázquez-Vilaplana

    2018-03-01

    Full Text Available Aunque la legislación española no reconoce como violencia de género la Trata de Personas con Fines de Explotación Sexual, lo cierto es que desde distintas instancias se está trabajando para su modificación en línea con los acuerdos internacionales firmados y ratificados por el Gobierno español y con las voces que se han alzado desde la sociedad civil. Su estrecha relación con la prostitución, su confusión con el tráfico ilícito de personas y el baile de datos que existe para su cuantificación, lo han convertido en un fenómeno que muchos dicen desconocer pero que alcanza importantes cotas de presencia en el territorio. Visibilizar este fenómeno y abrir espacios para la reflexión son los objetivos de este trabajo.

  4. Mujeres invisibles y victimización sexual en México. El caso de la trata de mujeres en Monterrey

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    Arun Kumar Acharya

    2013-01-01

    Full Text Available El objetivo principal del artículo es analizar el fenómeno y la dinámica de la trata de mujeres hacia la ciudad de Monterrey, así como la explotación sexual y sus consecuencias. R esultados muestran que en los últimos años el fenómeno se ha incrementado en Monterrey por diversas cues tiones. El crecimiento económico ha provocado un aumento masivo de los viajes de negocios y turísticos. Paralelamente, se ha desarrollado el turismo sexual. Para satisfacer la demanda, los dueños de bares y centros de masajes viajan a las zonas marginadas del país, enganchan a muchachas jóvenes por medio de varias promesas y después las obligan a prostituirse. Las mujeres tratadas sufren una constante violencia y explotación, lo que afecta su salud física, mental y sexual.

  5. PREVENCIÓN, ATENCIÓN Y PROTECCIÓN DE LAS VÍCTIMAS Y POSIBLES VÍCTIMAS DE LA TRATA DE PERSONAS POR PARTE DEL MUNICIPIO DE MEDELLÍN.

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    Mauricio Bocanument-Arbeláez

    2011-05-01

    Full Text Available El fenómeno de la trata de personas alcanza hoy dimensiones similares al tráfico de drogas y armas. La mayoría de las víctimas son mujeres, niños y niñas, aquienes se les explota en la industria del sexo, mano de obra barata y matrimonios forzados. Para el año 2008, Medellín se encontraba en el segundo lugar de los municipios de Colombia con los mayores reportes de casos; por lo tanto, se consideró importante hacer un análisis de la política pública local dirigida a este problema. Lo anterior arrojó tres cosas: lo primero es que la política se encuentra en una fase de construcción; segundo, el municipio, en lugar de aquella, cuenta con medidas contra la prostitución y explotación o abuso sexual, especialmente dirigidas a menores de edad y; tercero, una de las principales causas de las dos anteriores es el tratamiento indistinto que le han dado los diferentes actores sociales a los problemas de: prostitución, explotación o abuso sexual y trata de personas.

  6. De la "letra de la ley" a la labor interpretante: la "vulnerabilidad" femenina en los procesos de judicialización de la ley de trata de personas (2008-2011)

    OpenAIRE

    Varela,Cecilia Inés

    2013-01-01

    Este trabajo constituye una aproximación a los primeros procesos judiciales de la trata de mujeres y niñas con fines de comercio sexual en la Argentina a partir de la sanción de la ley 26.364. Como corpus para la indagación se analizará un conjunto de autos de procesamiento confirmados por fallos de primera y/o segunda instancia, desde la puesta en marcha de la ley. Me propongo describir y analizar la labor interpretante desarrollada por los actores judiciales con el objetivo de constituir ac...

  7. ¿Es el EVA, realmente, un indicador del valor económico agregado? ¿Es el EVA, realmente, un indicador del valor económico agregado?

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    Hernán Herrera Echeverry

    2006-12-01

    Full Text Available In this article we analyze the relevance of EVA (Economic Value Added as a tool for measuring value added, as well as its usefulness as an indicator in choosing investment projects.  First, we show five ways of calculating EVA, providing examples of each case. Second, we show MVA (Market Value Added and NPV (Net Present Value to be equivalent as criteria used to evaluate investment projects.  This is done with both the limited term and the perpetual cases, as well as for projects with partial and total recovery of the investment.We present a thorough analysis, showing the possibilities and limitations of EVA as a value added measure.  We also introduce three measurements of residual income, CVA (Cash Value Added, Cash Flow Return on Investment (CFROI and Economic Profit (EP, which complement EVA in the value measurement process. Finally, we introduce an example that explicitly shows the equivalence between CVA’s present value, MVA and NPV.En este artículo se hace un análisis sobre la validez del EVA (Economic ValueAdded como una medida del valor generado, y de su utilidad para la evaluaciónde proyectos de inversión. Primero se muestran varias formas de calcular el EVA,haciendo ejercicios ilustrativos en cada caso, posteriormente se establece laequivalencia entre el MVA (Market Value Added y el VPN (valor presente netocomo criterios para la evaluación de proyectos de inversión finitos y perpetuos conrecuperación parcial y total de la inversión.Se realiza un examen crítico mostrando las limitaciones y posibilidades del EVAcomo medida de valor económico agregado, y se plantea la utilidad de indicadoresde ingreso residual para complementar al EVA como criterios de medición de valor,tales son el CVA (Cash Value Added, TRFC (tasa de retorno del flujo de caja yUtilidad Económica (UE. Finalmente, se hace un ejemplo en donde se explicitacómo el valor presente del CVA coincide con el MVA y el VPN.

  8. COCIENTES Y UNIDADES: ¿QUÉ COMPRENDEN REALMENTE LOS ESTUDIANTES DE FÍSICA DE NUEVO INGRESO A LA UNIVERSIDAD?

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    Antonio Lara Barragán Gómez

    2009-09-01

    Full Text Available Se presenta una estrategia didáctica para el aprendizaje de conceptos esenciales de física, fundamentada en la interpretación de cocientes y el uso de unidades de manera intencionada. La conceptuación de la división es el punto de partida de la estrategia.Se menciona una experiencia cualitativa en el aula en temas de electromagnetismo, que muestra que la estrategia propicia una comprensión adecuada de conceptos y permite, además, desarrollar y construir conceptos nuevos.

  9. COCIENTES Y UNIDADES: ¿QUÉ COMPRENDEN REALMENTE LOS ESTUDIANTES DE FÍSICA DE NUEVO INGRESO A LA UNIVERSIDAD?

    Directory of Open Access Journals (Sweden)

    Antonio Lara Barragán Gómez

    2009-01-01

    Full Text Available Se presenta una estrategia didáctica para el aprendizaje de conceptos esenciales de física, fundamentada en la interpretación de cocientes y el uso de unidades de manera intencionada. La conceptuación de la división es el punto de partida de la estrategia. Se menciona una experiencia cualitativa en el aula en temas de electromagnetismo, que muestra que la estrategia propicia una comprensión adecuada de conceptos y permite, además, desarrollar y construir conceptos nuevos.

  10. Revisitando as estratégias de momento: o mercado brasileiro é realmente uma exceção?

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    Pedro Guilherme Ribeiro Piccoli

    2015-06-01

    Full Text Available RESUMO No artigo, reexaminam-se as estratégias de momento a fim de verificar se a falta de evidências quanto a sua lucratividade no mercado brasileiro pode estar relacionada às quebras que elas experimentam durante as crises, conforme reportado por Daniel e Moskowitz. Para tanto, utilizou-se o teste t-student com o intuito de comparar os retornos médios auferidos pela carteira de momento dentro e fora das crises financeiras entre janeiro de 1997 e março de 2014. A partir dos resultados, demonstra-se que, em linha com o reportado para outros mercados, a carteira experimenta quebras durante as crises, ao passo que proporciona retornos positivos e significativos nos demais períodos, mesmo após o controle para os fatores de risco dos modelos do Capital Asset Pricing Model (CAPM e de Fama-French. Esses achados indicam que a falta de evidências quanto à lucratividade dessas estratégias não implica o entendimento do mercado brasileiro como uma exceção, mas pode ser explicada pela quebra das carteiras de momento durante as crises, que anulam grande parte dos retornos positivos auferidos por essa estratégia em outros períodos.

  11. ¿Los alumnos se aburren con la poesía?

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    José Coloma Maestre

    2012-08-01

    Full Text Available Con la pregunta del título de la experiencia, ¿los alumnos de E/LE se aburren con la poesía?, quiero reflexionar sobre qué motiva o no motiva realmente a nuestros alumnos cuando llevamos un texto a clase para trabajar con ellos. Veremos como para mí la actitud del profesor y las actividades que se generen a partir de ese texto serán fundamentales para conseguir el éxito y la atención de los alumnos.

  12. El control penal de las trabajadoras del sexo en el ámbito de las políticas contra la trata de mujeres con fines de explotación sexual (el caso español

    Directory of Open Access Journals (Sweden)

    Agustina Iglesias Skulj

    2011-06-01

    Full Text Available Este artículo retoma los cambios tanto en el ámbito del control de los flujos migratorios como en la emergencia de nuevas subjetividades políticas con el objeto de analizar el fenómeno de las migraciones femeninas. Asimismo, sugiere reexaminar el discurso de la protección de los derechos humanos construido con lógicas securitarias. Para ello se propone explorar las formas en las cuales el género y la sexualidad son visibilizados por las normas y los regímenes de control para producir diferenciaciones y estratificaciones entre la soberanía, las formas de trabajo y la ciudadanía. Por último, se consideran las nuevas gramáticas de control y las tecnologías activadas por el riesgo en el supuesto particular de la trata de mujeres para explotación sexual.

  13. El embarazo múltiple: ¿es realmente un factor de alto riesgo obstétrico?

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    Herrera León, Lorenzo

    2009-01-01

    Full Text Available El embarazo múltiple hoy en días esta adquiriendo dimensiones epidémicas, debido en gran medida a la inducción de la ovulación y al uso cada vez más frecuente de técnicas de reproducción asistida. Se sabe a través de diversos estudios que los fetos procedentes de embarazos múltiples poseen un riesgo de muerte fetal entre 5 y 10 veces superior al de tipo sencillo y también son más propensos a presentar bajo peso y una serie de episodios mórbidos comparativamente con los fetos únicos. Objetivo: Determinar el riesgo de mortalidad y estimar el nivel de sobrevivencia fetal según tipo de embarazo y factores asociados. Metodología: Se calcularon las tasas de mortalidad fetal atendiendo a factores como la edad materna, número de embarazos previos, abortos, sexo del feto y peso al momento de la expulsión, según el tipo de embarazo. Además se reconstruyeron cohortes de embarazos con lo que fue posible aplicar técnicas de tablas de vida para estimar las curvas de sobrevivencia del feto en útero. Resultados: Se confirmó el carácter esencialmente de riesgo del embarazo múltiple con respecto al sencillo, no obstante salió a la luz un grupo de paradojas como la de la edad materna avanzada para embarazos múltiples, la cual evidencia que a mayor edad materna el riesgo de experimentar muerte fetal descrece en los embarazos múltiples. Algo similar ocurrió con el número de embarazos previos tenidos por las gestantes. Otro hecho paradójico lo constituyó el factor peso, por conducto del cual se manifestó que en las categorías inferiores de peso, el feto procedente de un embarazo múltiple posee un riesgo similar e incluso menor que el sencillo y consecuentemente una sobrevivencia en útero superior.

  14. O que realmente importa em programas de transferência condicionada de renda? Abordagens em diferentes países

    Directory of Open Access Journals (Sweden)

    Daiane Medeiros Roque

    2015-12-01

    Full Text Available Diferentes estratégias de proteção social têm sido utilizadas no mundo visando combater a fome e promover a mobilidade social. Dentre elas, os programas de transferência condicionada de renda têm se destacado pelo desenho contratual e pela estrutura de governança que tem a promoção do comportamento positivo do indivíduo, e não a assistência, como elemento central. Portanto, famílias que participam desses programas recebem, em geral, determinada quantia financeira destinada a satisfazer as necessidades básicas e contribuir para o atendimento das condições positivas impostas à sua manutenção no programa. Conhecer as condicionalidades e perceber sob qual contexto de investigação essas práticas têm sido abordadas no meio acadêmico torna-se fator de relevância científica e social. Nessa direção, este trabalho teve como propósito discutir os diferentes desenhos dessa política em diversos países. Para tanto, 50 trabalhos científicos, distribuídos por 28 países, foram analisados, visando contextualizar metodologias e resultados alcançados. Para realizar tal análise, foi procedido um estudo exploratório, a partir da técnica de metaestudo, utilizando como referência a base de dados do Banco Mundial, sítios eletrônicos e artigos sobre o assunto, publicados entre 2003 e 2011, com a finalidade perceber sob qual ótica têm sido estudados os principais programas de transferência de renda do mundo. Dentre os principais resultados alcançados, merece destaque o fato de, indiferentemente do país ou programa de transferência considerado, a manutenção das crianças na escola e o cuidado com a saúde infantil são condições centrais de inclusão e manutenção da família no sistema de transferência.

  15. Lo que se debe a las cimentaciones

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    Oroviogoicoechea, Alberto

    1975-05-01

    Full Text Available This article describes: the problems that arise when the foundations has to act on soils with low consistency or when very narrow tolerances have to be met; the origin of the above mentioned problems; the requirements that are not really necessary, with suitable examples; the absolute and relative admissible magnitudes of differential settlements in concrete structures, walls, partitions and metal structures; the tolerances for mechanical installations; recommendations for projects and a table that sums up the proposed tolerances for relative foundations.En el artículo se describen: los problemas que surgen cuando la cimentación ha de actuar sobre terrenos poco consistentes o cuando se quieren cumplir tolerancias muy estrechas; de dónde provienen dichos problemas; las exigencias que no son realmente necesarias, con ejemplos apropiados; las magnitudes absolutas y relativas admisibles de asientos diferenciales, en estructuras de hormigón, muros, tabiques y estructuras metálicas; las tolerancias para instalaciones mecánicas; recomendaciones para proyecto, y una tabla que recoge las tolerancias propuestas para asientos relativos.

  16. Víctimas de trata de personas versusmigrantes en situación irregular: Retos y lineamientos para la atención y protección delas víctimas de trata de personas extranjerasen el Perú

    OpenAIRE

    Blanco, Cristina; Marinelli, Chiara

    2017-01-01

    El texto apunta a determinar los aspectos que deben ser considerados para perfeccionar el funcionamiento del aparato estatal con el fin de luchar efectivamente contra la trata de personas de carácter transnacional y para orientarlo por los principios propios de un enfoque de derechos humanos con respecto a la víctima de trata de personas. Aborda cuatro puntos centrales. Primero, advierte la problemática particular de las víctimas de trata extranjeras, al ser proclive su confusión o superposic...

  17. ¿Es realmente una herejía hablar de equidad, justicia y confianza en las organizaciones?

    Directory of Open Access Journals (Sweden)

    Esteban Fernández Sánchez

    2010-06-01

    Full Text Available El objetivo de este trabajo era revisar las aportaciones de la literatura acerca de cómo evitar la destrucción de confianza y cómo crearla dentro de una organización, considerando que la misma constituye un recurso organizativo clave, especialmente en las organizaciones con determinadas características. Para ello, se revisaron las aportaciones de la teoría de la equidad y la justicia organizativa. La revisión de la literatura nos ha permitido concluir que el recurso confianza es escaso, fácil de destruir y prácticamente imposible de reconstruir.The aim of this paper is to review the contributions of the literature about how to avoid the confidence destruction and how to create it inside an organization. We have considered that confidence is a key organizational resource, specially in certain kind of organizations. With this objective, we have reviewed the contributions of the theory of equity and the theory of organizational justice. The review of the literature has allowed us to conclude that the resource confidence is scanty, easily to destroy and practically impossibly to reconstruct.

  18. A avaliação pré-anestésica para cirurgia oftalmológica em idosos é realmente necessária? A realidade de um hospital público

    Directory of Open Access Journals (Sweden)

    Flora Margarida Barra Bisinotto

    Full Text Available RESUMO Objetivos: A avaliação pré-anestésica (APA e a realização de exames laboratoriais são questionadas para cirurgias oftalmológicas ambulatoriais por acrescentarem custos e retardarem a cirurgia. Estas são de baixo risco, mas os pacientes são idosos e com várias comorbidades. O objetivo deste estudo foi determinar se a APA é realmente necessária nestes pacientes em um hospital público. Métodos: Foi conduzido um estudo retrospectivo em 297 prontuários contendo a APA de pacientes para cirurgias oftalmológicas em um hospital público. Foram avaliados através da história, exame clínico e exames complementares, a proporção de pacientes que apresentaram na APA doenças desconhecidas ou não controladas e alterações dos exames complementares. Resultados: A média de idade dos pacientes foi de 71,5 anos, com 95,28% tendo pelo menos uma doença crônica. A doença mais prevalente foi hipertensão arterial sistêmica (62,96%, que em 7,7% dos pacientes estavam sem controle adequado; 2.3% não tinham diagnóstico de HAS. O diabetes mellitus tipo 2 apareceu em segundo (22,22%, com 5,3% sem controle adequado. Glicemia acima de 100 mg.dl-1 foi encontrada em 25,92%, sem diagnóstico conhecido. Do total, 84,8% tomavam pelo menos um medicamento. Somente 73,4% dos pacientes foram liberados para a cirurgia na primeira consulta. Conclusão: A APA em oftalmologia é capaz de detectar doenças não diagnosticadas, ou condições clínicas instáveis, e exerce um papel não só de otimização do paciente para a cirurgia como de atendimento primário, desempenhando papel importante na saúde global da população e, portanto, considerada necessária nos pacientes idosos do sistema público de saúde.

  19. «Bajo el casco de Hades»: menores migrantes no acompañadas como posibles víctimas de trata y su triple invisibilización

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    María J. García de Diego

    2013-12-01

    Full Text Available El presente texto pretende acercarse al caso de las menores migrantes no acompañadas, con el fin de visibilizar las peculiaridades de su proyecto migratorio y el contexto en el que viven en España. Este artículo considera transversal la perspectivade género y recoge las incidencias de trata de seres humanos y explotaciónde estas menores migrantes.Desde comienzos de siglo ha aumentado el número de las menores que llegan a nuestro país. A las dificultades, ya conocidas, que enfrentan los menores no acompañados, se añaden otras que las chicas sufren en virtud de su género. Estas menores son, en ocasiones,víctimas de redes de explotación sexual, laboral o, tristemente ambas

  20. La ruta Atlántica del pensamiento afrodescendiente. Hacia un referencial teórico afro sobre la historia de la trata transatlántica, la esclavitud perpetua y la invención del sofisma racial

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    Christianne Silva Vasconcellos

    2014-01-01

    Full Text Available Este artículo tiene el propósito de presentar un referencial teórico escrito en las rutas del Atlántico por personas africanas y afrodescendientes, entre los siglos XVIII y XIX. En particular se abordará la interpretación de tres procesos históricos relevantes en la historia de América: la trata transatlántica, la esclavitud perpetua y la invención y uso del sofisma racial. Las autoras y autores que aquí señalaremos teorizaron las experiencias que atravesaron en el seno de sociedades esclavistas y racialistas en América, el Caribe y Europa a punto de forjar un pensamiento propio que está registrado en cartas, poemas, novelas, autobiografías y tesis académicas. Lo que aquí se propone es que estas versiones conforman un referencial teórico capaz de descolonizar la comprensión de la historia de la Diáspora Africana en los centros educativos y académicos en América.

  1. Análisis de la influencia de los organismos adscritos a la organización de naciones unidas (UNICEF- ECPAT) en la solución de la problemática de la trata de niños en el sudeste asiático continental. periodo 2000-2010

    OpenAIRE

    Granada Brito, Juliana

    2014-01-01

    La trata de niños es un fenómeno cada vez más relevante en el sistema internacional y ha generado importantes esfuerzos de cooperación de agencias internacionales como UNICEF y ECPAT. En ese sentido, ambos organismos han enfocado su actividad en las regiones donde se han registrado los mayores índices de violación de los Derechos Humanos. Este Estudio de Caso se ha centrado en el Sudeste Asiático continental conformado por Tailandia, Laos, Camboya, Vietnam, Singapur, Myanmar y Malasia; con ...

  2. La reforma del Código penal español motivada por la trasposición de la Directiva 2011/36, sobre prevención y lucha contra la trata de seres humanos y protección de las víctimas.

    Directory of Open Access Journals (Sweden)

    Tania García Sedano

    2013-06-01

    Full Text Available El presente artículo aborda el análisis del Anteproyecto de Ley Orgánica por la que se modifica la Ley Orgánica 10/95, de 23 de Noviembre, del Código Penal en lo que atañe al delito de trata de seres humanos, regulado en artículo 177 bis. El análisis se realiza desde el punto de vista del cumplimiento por España de sus obligaciones internacionales, en concreto la incorporación de la Directiva 2011/36/UE.

  3. Género y violencia: La trata de personas con fines de explotación sexual en Misiones. 16H279

    OpenAIRE

    Moniec, Susana, dir.; Montiel, Sandra; Fuentes, Guillermo

    2009-01-01

    La trata de personas con fines de explotación sexual es uno de las formas extremas de discriminación de género. Constituye la forma moderna de esclavitud focalizada en la explotación sexual de mujeres prioritariamente y de niños en segundo lugar. Es una nueva forma de servidumbre sexual, con modalidades distintas a partir de la expansión global de los negocios, y de los usos tecnológicos. Pero sostiene como característica principal de todos lo...

  4. El bien jurídico protegido por el delito de trata de personas en el ordenamiento jurídico peruano

    OpenAIRE

    Villarroel Quinde, Carlos Abel

    2017-01-01

    La presente investigación tiene por objeto analizar dogmáticamente el bien jurídico protegido por el delito de trata de personas en el ordenamiento jurídico peruano. Al respecto, existen diversas posturas sobre dicho tópico, lo que determina la poca o nula aplicación del tipo penal de acuerdo al bajo índice de sentencias expedidas por dicho delito en nuestro país. En ese sentido –a partir de un análisis exclusivamente teórico, basado en fuentes jurídicas (normas, jurisprudencia...

  5. Limitaciones temporales en la investigación técnica científica especializada de la DIRINTRAP en los casos de flagrancia del delito por trata de personas en la modalidad de explotación sexual de menores de edad en Lima Metropolitana durante 2015

    OpenAIRE

    Vergaray Van Meerbeck, Eduardo Mesías

    2016-01-01

    La presente investigación busca comprender como operan los procedimientos que se encuentran en las coordinaciones entre la Policía Nacional del Perú y el Ministerio Público en la investigación del delito de trata de personas. La investigación de este delito debería, en teoría, contar con el respaldo institucional de las partes involucradas. Sin embargo, los hallazgos de la investigación demuestran la existencia de una serie de problemáticas en las coordinaciones entra ambas ...

  6. A Sociedade do Conhecimento realmente existente na perspectiva do desenvolvimento desigual The really existing Knowledge Society from the perspective of uneven development

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    Ivo Marcos Theis

    2013-06-01

    Full Text Available Tem sido afirmado, sobretudo, nos três últimos decênios, tanto na academia quanto em outros ambientes, que se vive numa sociedade do conhecimento. Esta seria amparada por uma nova economia, fundada no uso cada vez mais intensivo de informação e conhecimento. Mas, pode-se aceitar que se vive numa sociedade do conhecimento? Que uma nova economia, movida pela aceleração de ciência, tecnologia e inovação, dá sustentação a essa sociedade do conhecimento? Neste breve ensaio se pretende jogar luz sobre alguns aspectos que encobrem a noção de sociedade do conhecimento, visando-se um questionamento das bases sobre as quais essa sociedade do conhecimento poderia emergir. É possível que a sociedade atual seja uma na qual a informação, o conhecimento, a ciência, a tecnologia e a inovação tenham sua centralidade. Contudo, além da centralidade dessas dimensões, também é um traço dessa sociedade do conhecimento uma dinâmica cada vez mais favorável à busca de ganhos econômicos e ao enriquecimento dos estratos mais abastados da população em escala planetária, de modo que há problemas em se considerar que qualquer indivíduo pode ingressar no admirável mundo novo do conhecimento. Talvez, por se desprezar que ele é atravessado por múltiplas implicações econômicas, tecnológicas, ambientais, culturais, políticas e ideológicas.

  7. Se trata de escribir un poema con los pies…”, el homenaje de Enrique Lihn a Rubén Darío en Casa de las Américas

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    Marcela Zanin

    2011-12-01

    Full Text Available O trabalho apresentado aborda o poema-homenagem de Enrique Lihn “Varadero de Rubén Darío”, publicado no número 42 da Revista Casa de las Américas, observando a perspectiva de ruptura e desafio que o poeta chileno desenvolve no marco das releituras dos anos 70 do século XX, a qual nos permite falar mais de uma modulação de uma anti-homenagem do que da retórica de uma celebração. Atentamos, em particular, aos modos em que o discurso de Enrique Lohn retoma e reformula os temas da crítica dariana, sobretuo  aqueles do afrancesamento e da representação do “hombre que siente” (Rodó.

  8. El escaso reflejo que todavía tiene en los medios de comunicación la imagen corporal de las chicas y el acoso escolar. Cuando se trata de algo más que causa y efecto

    OpenAIRE

    Fernández Guerrero, Manuel; Suárez Ramírez, Miriam; Godoy Merino, María José

    2012-01-01

    Con este trabajo pretendemos reseñar la poca transcendencia que tienen en los mass media al acoso escolar. Actualmente, el acoso escolar es casi un tema “tabú” no solo en los medios de comunicación, sino también en la educación, a pesar de que son actos que ocurren a diario en todos los centros educativos con más o menos frecuencia en el que predomina el género masculino como agresor y el femenino como víctima. Para profundizar en este asunto, hemos realizado una investigación basada en ...

  9. Bioconectores: ¿son realmente eficaces en la reducción de las bacteriemias relacionadas con el catéter permanente para hemodiálisis?

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    Isabel Crehuet Rodríguez

    Full Text Available Uno de los mayores problemas que presentan los catéteres venosos centrales tunelizados para hemodiálisis son las infecciones, por su gravedad y los elevados costes que generan. Por ello, es importante su prevención, ya que, además, el número de catéteres ha aumentado considerablemente en los últimos años. Objetivos: Realizamos este estudio en nuestra unidad para analizar: • Eficacia de unos conectores con sistema cerrado (TEGO® en la prevención de bacteriemia relacionada con el catéter. • Incidencia de Staphylococcus aureus y gérmenes causantes más frecuentes. Material y método: Se realizó un estudio retrospectivo, comparativo y transversal durante 800 días, que dividimos en dos periodos iguales. En los primeros 400 se aplicó el protocolo de la unidad a 24 pacientes y en los 400 días siguientes se aplicó el mismo protocolo más los conectores anteriormente citados a 25. En ambos periodos, 19 fueron los mismos pacientes. Resultados: En el primer periodo se contabilizaron 4 infecciones en 7062 días de catéter y en el segundo 2 infecciones en 8622 días de catéter. Índice de bacteriemia en ambos periodos: 0,56/1000 y 0,23/1000 respectivamente. Ninguna infección se produjo por Staphylococcus aureus, siendo el germen más frecuente Staphylococcus coagulasa negativo. Conclusión: Nuestra conclusión es que los conectores fueron eficaces en la prevención de las bacteriemias ya que redujeron notablemente nuestros, ya bajos, índices de las mismas.

  10. Trabajo adolescente en la extracción de madera en la Amazonía peruana: explotación laboral, trabajo forzoso, trata de personas

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    Jaris Mujica

    2016-12-01

    Full Text Available La extracción de madera es la actividad económica más importante de la Región Ucayali (al este de la Amazonía peruana, aunque un gran porcentaje de esa extracción es ilegal. Esta investigación describe las precarias condiciones de vida y trabajo en los primeros eslabones de la cadena del comercio de madera, y los elementos asociados a la explotación laboral de adolescentes varones, en la dinámica de extracción en caseríos rurales de la cuenca del río Utuquinía (a siete horas de navegación de la ciudad de Pucallpa, capital de la región Ucayali. Sostenida en el análisis de 27 casos este artículo describe: i la función de la mano de obra adolescente en la dinámica de extracción de madera; ii las condiciones de explotación de estos adolescentes, los que aparecen asociados a la precariedad del escenario y a las severas condiciones de inseguridad extendidas en aquellas localidades; iii un escenario marcado por la precariedad en el que conviven víctimas de explotación, trabajo forzoso y trata de personas.

  11. ¿Representa la expresión patrimonio neto como rubro de los estados contables, lo que realmente quiere representar?

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    Norberto García

    2003-10-01

    Full Text Available El objetivo de este trabajo es señalar la ambigüedad en la utilización de la expresión patrimonio neto como rubro del balance general en la literatura y práctica contable de los países Continentales Europeos, (incluyendo dentro de estos a los países Latinoamericanos. En primer lugar, para lograr el propósito se efectúa una recorrida por los diccionarios de la lengua española e inglesa para analizar las distintas acepciones de la palabra patrimonio, como así también desde el punto de vista del derecho vigente. Luego se analiza el concepto de patrimonio aplicado a la contabilidad tanto desde el punto de vista de la literatura contable Continental Europeo como de la Literatura Anglo Sajona, aunque en esta última no se aplica estrictamente la expresión patrimonio. Para esta finalidad, se hace uso fundamentalmente de la bibliografía Italiana centrada en las obras de Besta y Onida, como representantes de las ideas Continentales Europeas y a Paton en lo que se refiere a las ideas Anglo Sajonas. Al entrar al examen del uso de la palabra patrimonio o patrimonio neto en el balance general en uso en los países Continentales Europeos, se hace hincapié a la ambigüedad que resulta cuando uno hace la pregunta ¿Patrimonio de quién? Si se observa las partidas que están debajo del rubro "Patrimonio Neto" (Capital suscrito, Reservas. Resultados no Asignados uno diría rápidamente que el patrimonio allí representado es el patrimonio de los propietarios, afirmación que no es correcta. En este sentido el uso de la expresión Anglo Sajona "Owner equity" (Participación de los propietarios evita tal ambigüedad.This study aims to point out the ambiguity that exists in the use of net equity as a group of balance sheet accounts in Continental European accounting literature and practice (including Latin-American countries. In the first place, Spanish and English language dictionaries are consulted in order to analyze the different meanings of the

  12. Despistaje rutinario de Síndrome de Cushing en pacientes con obesidad mórbida: ¿es realmente necesario?

    OpenAIRE

    María Rosa Alhambra Expósito; Carmen Tenorio Jiménez; María José Molina Puerta; Gregorio Manzano García; Inmaculada Prior Sánchez; Concepción Muñoz Jiménez; María Ángeles Gálvez Moreno

    2014-01-01

    Introducción: El síndrome de Cushing (SC) es más frecuente en pacientes con síndrome metabòlico. Estudios previos han sugerido que es necesario realizar un despistaje de SC en pacientes obesos; sin embargo, estudios más recientes sólo recomiendan el despistaje en pacientes con hipertensión o diabetes mal controlados, a pesar de tratamiento. Objetivo: Evaluar la prevalencia de SC oculto en pacientes con obesidad mórbida. Pacientes y métodos: Estudio observacional retrospectivo en el que se inc...

  13. ¿Son realmente tan buenos los nativos digitales?: relación entre las habilidades digitales y la lectura digital

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    Inmaculada Fajardo

    2016-01-01

    Full Text Available La competencia en la lectura digital consiste en la comprensión, uso, reflexión y disfrute de los textos escritos con el fin de conseguir nuestros objetivos, desarrollar nuestro conocimiento y potencial, y participar en nuestra sociedad. En la actualidad se considera que los "nativos digitales", aquellos estudiantes que desde la infancia han crecido rodeados de las tecnologías de la información, poseen las habilidades digitales básicas (usar el ratón, el navegador, ... necesarias para desarrollar la competencia en la lectura digital. En el presente estudio ponemos a prueba esta visión, a partir de un estudio en el que estudiantes de 5º de Primaria y 3º de Secundaria realizaron una serie de tareas de lectura digital. Los estudiantes completaron asimismo varias pruebas objetivas para medir sus habilidades digitales básicas, así como su nivel de competencia lectora en papel. Los resultados mostraron que los estudiantes no sólo presentaban dificultades en numerosas habilidades digitales básicas, si no que éstas estaban relacionadas directamente con el éxito en tareas de lectura digital. Para concluir, se reflexiona sobre la necesidad de considerar la instrucción en las habilidades digitales básicas como parte de los esfuerzos actuales por mejorar la competencia en la lectura digital.

  14. Retos en el cumplimiento del protocolo de Palermo. Estudio de caso: trata de personas con fines de explotación sexual en Colombia

    OpenAIRE

    Arévalo Beltrán, Laura Ximena

    2016-01-01

    El presente estudio de caso tiene como objetivo analizar los retos frente al cumplimiento del Protocolo de Palermo, en materia de explotación sexual, en el Sistema Institucional Colombiano, durante el período comprendido entre los años 2003 y 2014. De manera preliminar se indica que dichos retos son político-jurídicos en cuanto a la manera en la que se cumplen los tratados internacionales, las obligaciones derivadas de ellos y quiénes tienen competencia para desarrollar los mandatos contenido...

  15. Is natural history really dead?: Toward the rebirth of natural history ¿Está realmente muerta la historia natural?: Hacia el renacimiento de la Historia Natural

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    MARY F WILLSON

    2006-06-01

    Full Text Available In recent years natural history has been derided by some scientists as an old-fashion endeavor that does not follow the model of "hard" science and therefore should be considered "dead" and replaced by modern ecology, evolutionary biology, and conservation biology. We contend that natural history has much to offer to contemporary scientists and that it has a primary role in the creative process of generating novel hypotheses and designing significant field experiments and observationsEn años recientes, la historia natural ha sido desacreditada por científicos que la consideran un modelo obsoleto de ciencia y que, en consecuencia, se trataría de una disciplina "muerta" que ha sido reemplazada por la ecología moderna, la biología evolutiva y la biología de la conservación. Argumentamos aquí que la historia natural tiene mucho que ofrecer a los científicos contemporáneos y que juega un rol principal en el proceso de creación de hipótesis y en el diseño acertado de observaciones y experimentos de campo

  16. The incandescent lamps in Mexico; are they really a beneficial technology?; Las lamparas incandescentes en Mexico: son realmente una tecnologia benefica?

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Rivero, A. G. [Genertek, S.A. de C.V., Mexico, D. F. (Mexico)

    1995-12-31

    The versatility of the incandescent lamps has originated a sustained increment of its population all over the world. Because of its characteristics they continue being irreplaceable in numberless applications, that go from the movies up to the medicine. Nevertheless the greatest population are represented by the incandescent lamps A-19 with the well-known negative effects to the environment and the economy caused by the electric power generation by conventional methods. No doubt about it, the best option to substitute them are the compact fluorescent lamps (CFL), but the economical barriers, the market and the performance do not permit its massive application in Mexico. In this paper a proposal is set forth that might bring high benefits with a minimum investment and rapid implementation. [Espanol] La versatilidad de las lamparas incandescentes ha causado un incremento sostenido de su poblacion en todo el mundo. Dadas sus caracteristicas continua siendo insustituible en un sinnumero de aplicaciones, que van desde el cine hasta la medicina. Sin embargo, la mayor poblacion la representan las ineficientes lamparas incandescentes A19 con los consabidos efectos negativos en el medio ambiente y la economia, causados por la generacion de energia electrica por medios convencionales. Sin duda, la mejor opcion para sustituirlas son las lamparas compacto fluorescentes (LCF), pero las barreras economicas, de mercado y de desempeno no permiten su aplicacion masiva en Mexico. En este trabajo se hace una propuesta que puede permitir grandes beneficios con minima inversion y rapida implementacion.

  17. The incandescent lamps in Mexico; are they really a beneficial technology?; Las lamparas incandescentes en Mexico: son realmente una tecnologia benefica?

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Rivero, A G [Genertek, S.A. de C.V., Mexico, D. F. (Mexico)

    1996-12-31

    The versatility of the incandescent lamps has originated a sustained increment of its population all over the world. Because of its characteristics they continue being irreplaceable in numberless applications, that go from the movies up to the medicine. Nevertheless the greatest population are represented by the incandescent lamps A-19 with the well-known negative effects to the environment and the economy caused by the electric power generation by conventional methods. No doubt about it, the best option to substitute them are the compact fluorescent lamps (CFL), but the economical barriers, the market and the performance do not permit its massive application in Mexico. In this paper a proposal is set forth that might bring high benefits with a minimum investment and rapid implementation. [Espanol] La versatilidad de las lamparas incandescentes ha causado un incremento sostenido de su poblacion en todo el mundo. Dadas sus caracteristicas continua siendo insustituible en un sinnumero de aplicaciones, que van desde el cine hasta la medicina. Sin embargo, la mayor poblacion la representan las ineficientes lamparas incandescentes A19 con los consabidos efectos negativos en el medio ambiente y la economia, causados por la generacion de energia electrica por medios convencionales. Sin duda, la mejor opcion para sustituirlas son las lamparas compacto fluorescentes (LCF), pero las barreras economicas, de mercado y de desempeno no permiten su aplicacion masiva en Mexico. En este trabajo se hace una propuesta que puede permitir grandes beneficios con minima inversion y rapida implementacion.

  18. Prueba chi-cuadrado y enfoque de señales como modelos de alerta temprana de crisis bancarias: aplicación al caso ecuatoriano

    OpenAIRE

    Rumbea Pavisic, Juan Francisco; Ayala Salcedo, Roberto Andres

    2009-01-01

    Este trabajo trata de modelar la crisis bancaria del Ecuador en 1995-1996. Para esto se analiza las situaciones específicas que diferencian a los bancos de otras empresas en una economía de mercado. Luego, se analiza la experiencia de la crisis. Finalmente se elabora un modelo de alerta temprana para la crisis bancaria de 1995-1996 basado en el enfoque de señales y prueba Chi-cuadrado.

  19. Is a 5 mm rat calvarium defect really critical? Um defeito de 5 mm em calota craniana de rato é realmente critico?

    Directory of Open Access Journals (Sweden)

    Gabriela Granja Porto

    2012-11-01

    Full Text Available PURPOSE: To evaluate bone regeneration in critical defects in the rats' calvarium. METHODS: Eighteen rats Wistar were divided into three groups of six animals each according to the time of evaluation (15, 30 and 60 days. One calvarium defect of 5mm was made in the parietal bone of each animal under general anesthesia. After the time of evaluation, the animals were killed, when the bone was histological studied and classified according to the type of tissue found: fibrosis or bone. RESULTS: The results showed that in the group of 15 days, in five animals there was only fibrosis. In the group of 30 days, the process of regeneration was growing and in four animals was found bone, in three with partial filling and in the other one with complete filling of the defect. In the group of 60 days, out of the three animals with bone, two had a complete filling of the defect. CONCLUSIONS: There was no bone regeneration in critical defects in 15 days. There was regeneration in the most part of the animals in 30 and 60 days.OBJETIVO: Avaliar a regeneração óssea de defeitos críticos em calota craniana de ratos. MÉTODOS: Foram utilizados 18 ratos Wistar que foram distribuídos em três grupos de acordo com o tempo de avaliação (15, 30 e 60 dias. Na calota craniana desses animais foi realizado defeito de 5mm, após anestesia geral prévia. Após o tempo de avaliação, os animais foram submetidos à eutanásia e a calota foi enviada para estudo histológico, quando foi classificada de acordo o tecido encontrado: fibroso ou ósseo. RESULTADOS: Diante dos achados deste estudo, pode-se observar que para o grupo de 15 dias na maioria dos animais, n=5, foi encontrado apenas fibrose. Com o passar do tempo de avaliação, no grupo de 30 dias, o processo de reparo foi evoluindo e em quatro animais já foi encontrado osso, sendo em três com preenchimento parcial e em um completo. No grupo de 60 dias, o processo praticamente permaneceu o mesmo, onde em tr

  20. Contenha-se, se for capaz

    Directory of Open Access Journals (Sweden)

    Mirna Feitoza Pereira

    2008-11-01

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

  1. Por uma cidade que se move e se comunica: corpo, rua e improviso

    Directory of Open Access Journals (Sweden)

    Julia Saldanha Vieira de Aguiar

    2009-06-01

    Full Text Available Este trabalho trata da relação de um lugar com suas pessoas. A reflexão acontece a partir de um estudo de caso: o Camelódromo da Praça XV. O Camelódromo foi uma grande feira, que durante 40 anos ocupou um espaço importante no centro de Porto Alegre/RS. (Auto organizado e vivido principalmente pelo povo, o fenômeno se configurava em um lugar onde improviso e estética constituiam o modo de ser e agir no cotidiano da rua. Ironicamente, no início de 2009, o Camelódromo foi transferido para dentro de um prédio. Hoje, onde se desenrolava o espetáculo do imprevisível, encontra-se um estacionamento para carros. Este trabalho foi produzido nos últimos meses do Camelódromo; em um espírito de elogio à estética do improviso e à auto-organização. Buscamos articular idéias da teoria da complexidade, do urbanismo, das artes e da comunicação, para tentar compreender um pouco essa manifestação espontânea, tão característica da urbe no século XXI.

  2. Información, señal, comunidad y contexto: su importancia al tratar con sistemas adaptativos complejos

    Directory of Open Access Journals (Sweden)

    Jordi Guzman

    2007-07-01

    Full Text Available El artículo trata de las diferencias entre información y conocimiento, así como de la relevancia del contexto en el aprendizaje, el cual se da dentro de una cultura en competencia por su supervivencia con otras culturas. Estas características definen un sistema adaptativo complejo, que se asemeja a la conducta de las especies que luchan por sobrevivir a los cambios de un entorno en continuo movimiento.

  3. Future strategy of SE

    International Nuclear Information System (INIS)

    Arcelli, M.

    2006-01-01

    In this presentation author (General Director of Slovenske elektrarne, a. s.) presents structure and investment plans of SE. The feasibility study of construction of the blocks 3 and 4 of the Mochovce NPP is presented

  4. SE-VYZ

    International Nuclear Information System (INIS)

    Anon

    2004-01-01

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

  5. SE debt restructuring plan

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

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

  6. Autismos que se 'curan'

    OpenAIRE

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

    2016-01-01

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

  7. Como o ortopedista brasileiro trata entorse lateral aguda do tornozelo? How does the brazilian orthopedic surgeon treat acute lateral ankle sprain?

    Directory of Open Access Journals (Sweden)

    Paulo Santoro Belangero

    2010-01-01

    Full Text Available OBJETIVO: A entorse lateral aguda do tornozelo (ELAT é uma afecção frequente cujo tratamento ainda não se encontra totalmente estabelecido. O objetivo do estudo foi verificar a conduta do médico ortopedista brasileiro (incluindo residentes em relação ao diagnóstico, classificação, tratamento e complicações da entorse lateral aguda do tornozelo (ELAT. MÉTODOS: Um questionário de múltipla escolha foi elaborado com objetivo de abordar os principais aspectos do tratamento da ELAT. O questionário foi veiculado na página eletrônica oficial da Sociedade Brasileira de Ortopedia e Traumatologia, no período de 15 de junho a 1º de agosto de 2004. RESULTADOS: Foram incluídos para análise um total de 444 questionários. Os resultados demonstraram concordância da maioria dos entrevistados em relação aos seguintes aspectos: 90,8% utilizam alguma classificação para nortear o tratamento da entorse; 59% classificam a ELAT com segurança; 63,7% utilizam imobilização rígida nas lesões ligamentares completas; 60,6% utilizam medicação anti-inflamatória na ruptura ligamentar parcial; 75,9% relataram que a dor residual é a complicação mais frequente. Não houve consenso quanto ao método de imobilização da ELAT parcial visto que imobilização e tratamento funcional foram escolhidos com a mesma frequência (47%. Não houve diferenças significativas entre as respostas dos residentes e a dos ortopedistas (p = 0,81. CONCLUSÕES: Os ortopedistas e residentes em ortopedia do Brasil têm dificuldade em classificar a ELAT e não há consenso quanto à melhor opção para a ELAT parcial.OBJECTIVE: Acute lateral ankle sprain (ALAS is one of the most common injuries, the treatment of which has yet to be firmly established. The purpose of this study was to determine the Brazilian Orthopaedic Surgeon's behavior in relation to diagnosis, classification, treatment and complications of the Acute Lateral Ankle Sprain. METHODS: A multiple choice

  8. Se comunican los investigadores

    OpenAIRE

    Rafael Roncagliolo

    2015-01-01

    En Brasil se reunieron los investigadores de la comunicación de América Latina y del mundo (1992) El encuentro Latinoamericano fue en Embú-Guacú, poblado de la periferia de Sao Paulo, y el encuentro Mundial en Guarujá, balneario cercano al Puerto de Santos. La amplitud de la participación y la diversidad de temas y enfoques son indicios del desarrollo y dinamismo de la profesión.

  9. Se comunican los investigadores

    Directory of Open Access Journals (Sweden)

    Rafael Roncagliolo

    2015-01-01

    Full Text Available En Brasil se reunieron los investigadores de la comunicación de América Latina y del mundo (1992 El encuentro Latinoamericano fue en Embú-Guacú, poblado de la periferia de Sao Paulo, y el encuentro Mundial en Guarujá, balneario cercano al Puerto de Santos. La amplitud de la participación y la diversidad de temas y enfoques son indicios del desarrollo y dinamismo de la profesión.

  10. Lectura teórica sobre la inclusión de la perspectiva de género en las políticas públicas para combatir la trata de personas en Colombia

    OpenAIRE

    Cardozo Lozano, Sandra Milena

    2010-01-01

    Este documento pretende a partir de preceptos feministas y de perspectivas provenientes de la administración pública y de la ciencia política, explicar la acción estatal a través de políticas o programas, legislaciones al más alto nivel que buscan reducir la trata de personas en Colombia, lo cual permite indagar sobre la inclusión de la transversalidad de la perspectiva de género en las políticas públicas.

  11. Entre la gobernanza social e institucional: Una mirada al fenómeno de la trata de personas en Colombia en el período entre 2000 y 2012

    OpenAIRE

    Pinilla Torres, Angélica María

    2014-01-01

    La presente monografía tiene por objetivo identificar la influencia de las acciones emprendidas por la sociedad civil y las organizaciones internacionales frente a la problemática de la trata de personas en Colombia, durante el período comprendido entre los años 2000 y 2012. En este sentido, la investigación constituye un esfuerzo por develar las transformaciones en las narrativas institucionales que han posibilitado el reconocimiento de los elementos de prevención y centralidad de las víctim...

  12. Empreendedorismo religioso: quando Weber se associa a Granovetter

    Directory of Open Access Journals (Sweden)

    Victor Silva Corrêa

    2016-12-01

    Full Text Available O fenômeno religioso no Brasil vem atraindo crescente atenção da academia, impulsionado, em grande parte, pela expansão das seitas protestantes no país, sobretudo de vertente pentecostal. Na esteira dessa transformação, um tema, em particular, reveste-se de especial importância. Trata-se do papel dos chamados empreendedores religiosos aqui compreendidos como os novos pastores evangélicos. No entanto, tais atores não vêm sendo muito estudados. O presente trabalho busca preencher essa lacuna. Recorre-se, para isso, às contribuições teóricas clássicas derivadas de Weber, em associação às contribuições contemporâneas originárias de Granovetter, em particular, sobre acoplamento e desacoplamento. Conclui-se o trabalho propondo um novo referencial para a análise de certas dimensões do empreendedorismo religioso.

  13. ZnSe/ZnSeTe Superlattice Nanotips

    Directory of Open Access Journals (Sweden)

    Young SJ

    2010-01-01

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

  14. Historia de la Ermita de Nuestro Señor de la Agonía. Liberia Guanacaste

    Directory of Open Access Journals (Sweden)

    Edgar Solano

    2011-11-01

    Full Text Available El artículo trata sobre la Historia de la Ermita de Nuestro Señor de la Agonía, ubicada en Liberia, Guanacaste. Las gestiones comunales ante el gobierno de Costa Rica para iniciar la construcción de la Ermita surgieron en la década de los años 40 del siglo XIX, pero debido a la guerra en Centroamérica,  se restableció hasta los años sesenta de ese siglo, cuando finalmente se inauguró.

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  16. Prostitución y trata de seres humanos con fines de explotación sexual : análisis de la situación actual a través de los anuncios de contactos

    OpenAIRE

    Gutiérrez García, Andrea

    2012-01-01

    La trata de personas es una forma de esclavitud moderna, una violación de derechos humanos que en el 90% de los casos tiene como fin la explotación sexual femenina, bien iniciándolas en la prostitución o en la pornografía, o utilizándolas para el turismo sexual. La prostitución no es una expresión de libertad sexual de la mujer, sino que tiene que ver con la violencia, la marginación, la dificultad económica y la cultura sexista y patriarcal. A pesar de esto, es un negocio que ha ...

  17. Resumen de tesis. La trata de seres humanos con fines de explotación sexual a partir de la reforma operada por LO 5/2010, de 22 de junio: enfoque victimocéntrico de la actuación policial

    OpenAIRE

    Martín Ancín, Francisco

    2015-01-01

    [ES]Hablar de una nueva forma de esclavitud, en estos tiempos, puede resultar extraño para muchas personas. Sin embargo, la trata no es otra cosa; bien claro lo dice el diccionario de la Real Academia: Trata: Tráfico que consiste en vender seres humanos como esclavos. La trata de personas, conocida como la esclavitud del siglo XXI, atenta frontalmente contra los valores superiores de nuestro ordenamiento jurídico, poniendo en jaque un bien tan preciado como es el de la dignidad humana. Los a...

  18. Los problemas en la implementación de la política pública de trata de personas, en el eje de persecución y sanción del delito, entre los años 2010 y 2014.

    OpenAIRE

    Manrique Pino, Víctor Andreé

    2015-01-01

    La Trata de Personas es considerada la esclavitud del siglo XXI y para afrontarla, desde el año 2000, 167 estados miembros de la Organización de Naciones Unidas han suscrito el “Protocolo para prevenir, reprimir y sancionar la Trata de Personas, especialmente en mujeres y niños”, o también conocido como “Protocolo de Palermo”. Este documento establece diversas obligaciones a sus estados parte para combatir la Trata de Personas. Tesis

  19. España se monta en el tren de alta velocidad

    Directory of Open Access Journals (Sweden)

    Pérez-Beato de Cos, Manuel

    1992-08-01

    Full Text Available This article tries to synthesize the historical antecedents leading up to the decision to construct this line, on the one hand, and the basic technical parameters of which it is composed, on the other.

    El presente artículo trata de sintetizar, de una parte, los antecedentes históricos por los que se decide la construcción de esta línea, y de otra, los parámetros esenciales que desde el punto de vista técnico la constituyen.

  20. Vivência de mulheres que se submeteram à gastroplastia

    Directory of Open Access Journals (Sweden)

    Glenda Agra

    2009-12-01

    Full Text Available A gastroplastia reduz as co-morbidades e melhora a qualidade de vida, resgatando a auto-estima e inclusão social doobeso mórbido. O estudo teve como objetivo investigar a vivência de mulheres que se submeteram à gastroplastia, apartir de seus discursos. Trata-se de um estudo exploratório com abordagem qualitativa, do qual participaram 16pacientes mulheres que se submeteram à cirurgia bariátrica. Os dados foram coletados nos meses de junho a julho de2007, por meio da técnica de entrevista semi-estruturada, com a utilização do sistema de gravação, as quais foramanalisadas qualitativamente, à luz da técnica do Discurso do Sujeito Coletivo. Emergiram as seguintes idéias centrais:elevação da auto-estima e bem-estar psicológico; promoção de bem-estar físico; mudança negativa no pós-operatórioimediato e mediato; mudança positiva após a fase de adaptação; possibilidade de maior socialização; satisfaçãofamiliar e pessoal enquanto mulher e maior disposição, segurança e melhor estado de humor. Conclui-se, portanto,que, a gastroplastia é um tratamento cirúrgico para obesos mórbidos, que remete à perda ponderal, melhora a autoestima,mas que traz conseqüências negativas. Daí a importância do cuidar destas pacientes desde a decisão de sesubmeter à cirurgia até a total reabilitação.

  1. Software como serviço : impacto nas empresas portuguesas

    OpenAIRE

    Araújo, Virgínia Maria da Silva

    2015-01-01

    Durante los años 90, se ha producido un cambio en la opinión sobre Internet se considera demasiado técnica y académica, emergiendo un creciente interés público en el tema que se vuelve popular a escala global. Las tecnologías están disponibles, pero nadie sabe realmente cómo tomar ventaja de ellas. Se trata de aprovechar el potencial de la red global, surge una profusión de ideas que hace algunos negocios exitosos emergen como es el caso de las empresas Yahoo y Google. Empresas e institucione...

  2. Extended analyses of Se VII and Se VIII

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  3. PHEIFFER SE TAALPOLITIEK JC Steyn

    African Journals Online (AJOL)

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

  4. Alteraciones en la comunicación entre rutas de señalización: un estudio transversal en cáncer

    OpenAIRE

    NEBOT FORCADA, PAU

    2016-01-01

    [ES] El cáncer se describe como un conjunto de enfermedades caracterizadas por un desarrollo tisular incontrolado, donde las células afectadas consiguen evadir los mecanismos intrínsecos de control frente a la muerte celular o la proliferación controlada. Se trata de enfermedades multi-génicas donde una serie de mutaciones en genes clave se encargan de dirigir el proceso de desarrollo tumoral. En este contexto, la biología de sistemas aporta el marco idóneo para el estudio del cáncer ya q...

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

  16. CUANDO LOS DOCENTES SE CONVIERTEN EN AUTORES DE TEXTO

    Directory of Open Access Journals (Sweden)

    Maria Sol Caríssimo

    2015-12-01

    Full Text Available Este trabajo relata una experiencia realizada por diferentes docentes como capacitación permanente. En el marco de "escribir textos de ciencias para el nivel terciario", se nos brindó la posibilidad de aprender a escribir ciencias, en el mas amplio sentido de la frase. Para llevar a cabo esta tarea y ver finalizada la obra, pasamos 1 año y varios meses trabajando en grupo, investigando, leyendo, escribiendo, releyéndonos y  reescribiendo. El aporte de esta experiencia es inmensurable, sobre todo si de estrategias de enseñanza e investigación se trata. La producción de textos resulta sumamente rica por la cantidad de relaciones que por ella se traman, la génesis constante entre colegas, eruditos acompañantes, nivel de lectura, tipos de textos leídos (muchísimos para la enseñanza de la escritura, además de los científicos y lo que todo esto deposita en el educador/autor. Los docentes que participamos del mismo, concluimos que la capacidad de brindar las clases específicas, su calidad, utilizando nuevos y mejores métodos de enseñanza aprendizaje es superior a las dictadas previamente; fuimos capaces de reconocer el transe en el proceso de E-A durante el periodo que llevamos a cabo la escritura; pudimos autoevaluarnos, ser críticos de nuestra propia labor, planificando un cómo mucho mejor.

  17. Señas Mexicano

    Directory of Open Access Journals (Sweden)

    Juan F. García Mejía

    2007-01-01

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

  18. Porøse materialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2000-01-01

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

  19. Modelos de Beaver, Ohlson y Altman: ¿Son realmente capaces de predecir la bancarrota en el sector empresarial costarricense? (Models of Beaver, Ohlson and Altman: are really able to predict the bankruptcy in the Costa Rican business sector?

    Directory of Open Access Journals (Sweden)

    José Alonso Vargas Charpentier

    2014-12-01

    Full Text Available El presente artículo analiza la aplicación de mo- delos para la prevención de bancarrotas empresariales en el sector empresarial costarricense. Se aplicaron los modelos a un grupo de empresas que se acogieron al proceso de intervención financiera, o quiebra, en el Juzgado Concursal de los Tribunales de Justicia de San José, con el fin de determinar si estos modelos fueron capaces de predecir la bancarrota. Dentro de los hallazgos principales están que el Modelo de Altman calificó a cuatro de las cinco empresas anali- zadas como zona roja el año en que se declararon en quiebra, el Modelo de Ohlson, con su ecuación O1 u O3, calificó en quiebra las cinco empresas el año en que se dio, y el modelo de Beaver calificó como el año con peores indicadores al último en tres oca- siones, a diferencia de los otros modelos, los cuales no indicaron que el año de quiebra tuviera los peores indicadores.   Abstract    This article analyzes the models for company bankruptcy prevention used by the Costa Rican business sector. The author applied the studies models to the selected group of companies that had started the judicial intervention or bankruptcy process within the Bankruptcy Court of the Justice Court of San Jose. The objective was to determine if the selected models were capable to prevent the bankruptcy before it initialized. The primary fin- ding was an EM Score 4:5 analyzed companies in the red zone that had filed for bankruptcy within that year. The use of the O1 and O3 equations of the Ohlson method was to predict the bankruptcy of the five companies in the year that had filed to have a bankruptcy case. However, in the Beaver method the companies scored a three as the worst indicators of the year to file for bankruptcy yet the remaining company’s worst year was not the ability to file for bankruptcy within the time.

  20. História, religião e literatura. caminhos que se cruzam no feminino

    OpenAIRE

    Avelino, Carla

    2016-01-01

    Soror Antónia Baptista, religiosa professa no Convento da Esperança de Vila Viçosa, redigiu o Livro da Fundação do santo Convento de nossa Senhora da esperança de Villa viçoza e de algũas plantas que em elle se criarão pera o ceo dignas de memoria, concluído em 1657. Trata-se de um exemplar único, autógrafo, que permaneceu manuscrito até hoje. A faceta de cronista da autora coabita com a de poetisa, almejando uma intencionalidade didática, de doutrinação, ao propor modelos de santidade...

  1. Qué puede hacer realmente un reumatólogo en la atención primaria de salud What can a rheumatologist do in primary health care

    Directory of Open Access Journals (Sweden)

    Reinaldo R Acosta Hernández

    2008-06-01

    Full Text Available INTRODUCCIÓN: la reumatología es una especialidad eminentemente hospitalaria que ha tenido un acercamiento beneficioso a la atención primaria en varios países. OBJETIVO: analizar el comportamiento de las consultas de reumatología en la atención primaria y su influencia sobre la atención hospitalaria. MÉTODOS: se realizó un estudio descriptivo prospectivo de sección transversal a 1 000 pacientes vistos en consulta externa en un período de 6 meses, a los que se recogieron sistemáticamente las variables: edad, sexo, color de la piel, casos nuevos, reconsultas y diagnóstico. Se determinaron los porcentajes, las medidas de frecuencia, de centralización, dispersión y razón reconsultas/casos nuevos. RESULTADOS: se efectuaron 1 122 consultas, y se analizaron los primeros 1 000 registros de nuestra base de datos. El 41,9 % fueron primeras visitas y 58,1 % reconsultas. Las 3 enfermedades más frecuentemente consultadas fueron: la osteoartritis (22,9 %, reumatismos de partes blandas (21 % y la artritis reumatoide (13,3 %, con un predominio de estas sobre las conectivopatías (2,1 %. La tasa de incidencia por enfermedades reumáticas fue de 2,5, y la de prevalencia de 6,2 x 1 000 hab. El promedio de edad fue de 49,4 años, DE 17,3 años, con predominio del sexo femenino en 71,6 % y color de piel blanca en 83,5 %. CONCLUSIONES: las consultas de reumatología en atención primaria descongestionan los servicios hospitalarios, que deben dedicar más tiempo al seguimiento de enfermedades reumáticas sistémicas.INTRODUCTION: rheumatology is an eminently hospital specialty that has had a beneficial approach to primary health care in various countries. OBJECTIVE: to analyze the behavior of the rheumatology consultations in primary health care and their influence on hospital attention. METHODS: a descriptive, prospective and cross-sectional study was conducted among 1 000 patients seen at the outpatient department during 6 months. The following

  2. El rol de las redes de apoyo transnacional en la evolución del régimen de trata de personas en la región del mekong, 2004-2015

    OpenAIRE

    Álvarez Martínez, Laura Camila

    2016-01-01

    Con el fin de la unipolaridad no sólo se fortalecieron mecanismos de gobernanza global como los Regímenes Internacionales, sino también se fortalecieron actores no estatales. A pesar de la importancia que tomaron estos dos elementos aún no existe una teoría que explique exhaustivamente la relación que existe entre ellos. Es por lo anterior que, la investigación busca responder de qué manera el rol de las Redes de Apoyo Transnacional ha incidido en la evolución del régimen de tráfico de person...

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

  7. Ud at se med Erasmus

    DEFF Research Database (Denmark)

    Frandsen, Pernille

    2009-01-01

    Få lidt luft under vingerne, kom ud at møde udenlandske kolleger og se, hvordan man også kan lave uddannelsesbibliotek. Med begejstring fortæller tre bibliotekarer om deres oplevelser i det store udland – alt sammen finansieret af Erasmus.......Få lidt luft under vingerne, kom ud at møde udenlandske kolleger og se, hvordan man også kan lave uddannelsesbibliotek. Med begejstring fortæller tre bibliotekarer om deres oplevelser i det store udland – alt sammen finansieret af Erasmus....

  8. Ud & se - med Claude Monet

    DEFF Research Database (Denmark)

    Bonde, Lisbeth

    2015-01-01

    Udstillingen 'Claude Monet - Lost in Translation - på ARoS stiller ind på Claud Monet og hans samtidige malerkolleger. Udstillingen forsøger at "genlæse" Monet fra et samtidskunstnerisk perspektiv - og vurderer hans indsats, inden hans værker er blevet reproduceret ihjel....

  9. X = S, Se, Te) heterostructures

    KAUST Repository

    Zhang, Qingyun; Schwingenschlö gl, Udo

    2018-01-01

    Using first-principles calculations, we investigate the electronic properties of the two-dimensional GaX/MX2 (M = Mo, W; X = S, Se, Te) heterostructures. Orbital hybridization between GaX and MX2 is found to result in Rashba splitting at the valence

  10. “¿De dónde eres realmente?” Apuntes sobre las ciencias sociales y la “crisis de la sociedad homogénea”

    Directory of Open Access Journals (Sweden)

    Silvia Rodríguez Maeso

    2015-11-01

    Full Text Available Partiendo del trabajo de Alfonso Pérez-Agote sobre la formación y “crisis” del “presupuesto de la homogeneidad” de las sociedades occidentales modernas, este texto interroga los límites de las ciencias sociales y más concretamente de la sociología dominante para interpretar esta “crisis” y el cambio social al que está asociada. Más específicamente, cuestiona el lugar que la categoría raza ha tenido en la sociología, como una perspectiva analítica crucial a la hora problematizar las narrativas hegemónicas sobre la modernidad, la formación del Estado-Nación y la construcción de la idea de Europa. Se argumenta que la comprensión de las llamadas “crisis del multiculturalismo” o “crisis de la integración de la inmigración” en la actualidad, requiere otorgar centralidad a la renovación del contrato racial como la ingeniería política de la pertenencia a la europeidad.

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

    Lifescience Database Archive (English)

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

  12. Is the outcome of schizophrenia really better in developing countries? O prognóstico da esquizofrenia é realmente mais favorável nos países em desenvolvimento?

    Directory of Open Access Journals (Sweden)

    Vikram Patel

    2006-06-01

    Full Text Available That schizophrenia has a better prognosis in non-industrialized societies has become an axiom in international psychiatry; the evidence most often cited comes from three World Health Organization (WHO cross-national studies. Although a host of socio-cultural factors have been considered as contributing to variation in the course of schizophrenia in different settings, we have little evidence from low-income countries that clearly demonstrates the beneficial influence of these variables. In this article, we suggest that the finding of better outcomes in developing countries needs re-examination for five reasons: methodological limitations of the World Health Organization studies; the lack of evidence on the specific socio-cultural factors which apparently contribute to the better outcomes; increasing anecdotal evidence describing the abuse of basic human rights of people with schizophrenia in developing countries; new evidence from cohorts in developing countries depicting a much gloomier picture than originally believed; and, rapid social and economic changes are undermining family care systems for people with schizophrenia in developing countries. We argue that the study of the long-term course of this mental disorder in developing countries is a major research question and believe it is time to thoroughly and systematically explore cross-cultural variation in the course and outcome of schizophrenia.O fato de que a esquizofrenia possui um melhor prognóstico em sociedades não industrializadas tornou-se um axioma na psiquiatria internacional; as evidências mais comumente citadas provêm de três estudos trans-nacionais da Organização Mundial da Saúde (OMS. Ainda que um conjunto de fatores socioculturais tenha sido considerado como contribuinte para o curso da esquizofrenia em diferentes ambientes, possuímos poucas evidências de países de baixa renda que demonstrem claramente a influência benéfica dessas variáveis. Neste artigo

  13. Hablando se entiende la gente

    Directory of Open Access Journals (Sweden)

    Mila Crespo Picó

    2012-08-01

    Full Text Available Habiendo observado que muchos cursos centrados en el desarrollo de la competencia comunicativa oral se limitan a ofrecer actividades inconexas que suponen un gran esfuerzo por parte de los participantes para situarse ante cada actividad y dificultan el establecimiento de relaciones profundas entre los exponentes nociofuncionales, los objetivos comunicativos y los recursos lingüísticos necesarios para realizarlas por contar con un tiempo limitado en el aula para ello, se presentó, bajo el mismo título que esta comunicación, una propuesta didáctica para un curso de conversación que pretende paliar estos aspectos en el I Foro de Profesores de E/LE en la Universitat de València.

  14. Die verpleegster se terapeutiese funksie

    Directory of Open Access Journals (Sweden)

    D.C. Harrington

    1980-09-01

    Full Text Available Ons sou hierdie praatjie graag wou inlei met Virginia Henderson se definisie van verpleging: “ The unique function of the nurse is to assist the individual, sick or well, in the performance of those activities contributing to health or its recovery (or to a peaceful death that he would perform unaided if he had the necessary will, strength or knowledge. And to do this in such a way as to help him gain independence as rapidly as possible.”

  15. EDUCAÇÃO DE JOVENS E ADULTOS: ENTRE VONTADES, DIREITOS E PROGRAMAS, O PENSAMENTO DE FREIRE SE (DESFAZ

    Directory of Open Access Journals (Sweden)

    Isabelle de Luna Alencar Noronha

    2014-04-01

    Full Text Available O analfabetismo de jovens e adultos continua a ser um problema ainda não resolvido em nosso país. A experiência histórica evidencia que as ações pautaram (e continuam a pautar-se em campanhas e programas que objetivam a erradicação do analfabetismo, mas que não chegam ao cerne do problema e, portanto, não conseguem resolvê-lo. O presente artigo traz reflexões a cerca do pensamento pedagógico de Paulo Freire com o objetivo de refletir como práticas e programas de alfabetização de adultos se utilizaram do ideário de Freire para fundamentar seus pressupostos. Trata-se de uma reflexão teórico-prática, fundamenta-se teoricamente nos trabalhos de Gadotti (2010, Freire (1991; 1981; 2010, Romão (2006, Gauthier e Tardif (2010 dentre outros que pensam a educação com uma visão progressista. O texto está estruturado em dois momentos o primeiro trata historicamente a educação de jovens e adultos e no pensamento de Paulo Freire; o segundo apresenta duas propostas para a educação de jovens e adultos, o Projovem Urbano e o Programa Brasil Alfabetizado, mostrando como a concepção de Freire se apresenta de forma ambígua nos discursos, mas não se efetiva nos processos de formação e na elaboração dos projetos.

  16. Vivienda Progresiva, un programa del sector público que se potenció en el hábitat rural chileno

    Directory of Open Access Journals (Sweden)

    Carlos Muñoz Parra

    2007-01-01

    Full Text Available La aplicación de este programa, producto de una sistematización de un hecho espontáneo de la población, que si bien se pensó para atender a la población de los dos deciles más bajos de ingresos en términos nacionales, ha tenido un desarrollo por resultados y demandas realmente destacable en el ámbito rural. Al resultar triunfadora la coalición denominada Concertación de Partidos Por la Democracia, con la candidatura presidencial de Patricio Aylwin a fines de 1989, se vislumbró por parte de los encargados de delinear lo que sería la política habitacional para ese gobierno, que se venia encima un grave problema. El tema radicaba fundamentalmente en que la producción habitacional durante el periodo de la dictadura había sido muy por debajo del crecimiento vegetativo de la población, y por otra parte, con la represión que existía, no había formas de dar un escape a la gran presión que se estaba desarrollando por obtener una solución habitacional a corto plazo. La espera había sido de 17 años, las respuestas pocas y deficientes, las expectativas creadas por tanto eran demasiadas. Ante tal cuadro, era menester crear un programa apropiado para la coyuntura, y sin lugar a dudas, ese fue el de la Vivienda Progresiva. Por la celeridad con que respondió a la demanda, la adecuación que tuvo hacia el usuario y su aprobación relevante por los sectores de más escasos recursos, fundamentalmente rurales, es que este programa se puede clasificar como un "Proyecto Ejemplar".

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  18. Sobre el uso de técnicas chopper para la reducción del ruido flicker en amplificadores para la captación de señales neuronales

    OpenAIRE

    Pérez Prieto, Norberto

    2016-01-01

    La captación de señales neuronales mediante electrodos conectados a circuitos micro-electrónicos es necesaria para aplicaciones clínicas y para el control de prótesis senso-motoras, entre otras muchas aplicaciones bio-médicas. En todas estas aplicaciones, la preservación de la información contenida en las imágenes captadas depende críticamente de las prestaciones de los amplificadores empleados en la cabecera de la cadena de procesamiento electrónica. El problema es que se trata de señales mu...

  19. Selenium Se and tellurium Te

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for determining selenium and tellurium in various objects are presented. The bichromatometric determination of Te in cadmium, zinc and mercury tellurides is based on oxidation of Te(4) to (6) in H 2 SO 4 with potassium bichromate. In steels, Te is determined photometrically with the aid of KI. The determination is hindered by Fe(3), Cu(2), Bi(3) and Se(4) ions, which must be separated. The extraction-photometric determination of Te in native sulfur is carried out with the aid of 5-mercapto-3-(naphthyl-2)-1,3,4-thiadiazolthione-2 (pH=4.8-5.0). The dyed complex is readily extracted with chloroform and benzene. The spectrophotometric determination of Te in selenium is performed with the aid of 3,5-diphenylpyrazoline-1-dithiocarbamate of sodium. Te is determined in commercial indium, arsenic and their semiconductor compounds photometrically with the aid of copper diethyldithiocarbamate. The method permits determining 5x10 -5 % Te in a weighed amount of 0.5 g. The chloride complex of Te(4) with diantipyriodolpropylmethane is quantitatively extracted with dichloroethane from hydrochloric acid solutions. Thus, any amounts of Te can be separated from Se and determined photometrically. The extraction-photometric determination of Te in commercial lead and bismuth is carried out with the aid of pyrazolone derivatives, in commercial copper with the aid of diantipyridolpropylmethane, and in ores (more than 0.01% Te) with the aid of bismuthol 2. Also described is the extraction-polarographic determination of Te in sulfide ores

  20. Se metallomics during lactic fermentation of Se-enriched yogurt.

    Science.gov (United States)

    Palomo, María; Gutiérrez, Ana M; Pérez-Conde, M Concepción; Cámara, Carmen; Madrid, Yolanda

    2014-12-01

    Selenium biotransformation by lactic acid bacteria during the preparation of Se-enriched yogurt was evaluated. The study focused on the distribution of selenium in the aqueous soluble protein fraction and the detection of selenoamino acids. Screening of selenium in Tris-buffer-urea soluble fraction was carried out by sodium dodecyl sulphate polyacrylamide gel electrophoresis after pre-fractionating with asymmetric field flow fractionation using inductively coupled plasma-mass spectrometry as the detector. Selenium-containing fractions were identified by peptide mapping using nano LC-ESI/LTQMS. Proteins such as thioredoxin, glutaredoxin, albumin, β-lactoglobulin, and lactoperoxidase were identified in the selenium-containing fraction. All these proteins were detected in both the control and the selenium-enriched yogurt except chaperones, which were only detected in the control samples. Chaperones are heat-shock proteins expressed in response to elevated temperature or other cellular stresses. Selenium may have an effect on chaperones expression in Lactobacillus. For the amino acids analysis, selenocysteine was the primary seleno-containing species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. La teoría de las inteligencias múltiples. La señora "A"

    OpenAIRE

    Murcia, Ester

    2011-01-01

    El sistema escolar vigente no trata igual a todas las inteligencias, da prioridad a la lógico matemática y a la lingüística. En los sistemas escolares actuales se está promoviendo el proceso de enseñanza y aprendizaje a través de actividades que promueven varias inteligencias. No es de extrañar que un niño tenga que hacer muchos ejercicios de matemáticas pero sin embargo no les enseñamos a prestar atención durante una conversación (tenemos el ejemplo de la cultura oriental). Se debe cambiar l...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  3. ¿Qué ocurrió realmente en Bolivia?

    Directory of Open Access Journals (Sweden)

    Mario Torrico

    2006-07-01

    Full Text Available This article seeks to dispute the explanations which assume that the process Bolivia is going through is similar to the processes other Latin–American countries are experiencing. These perspectives suggest the triumph of Evo Morales in the presidential elections of December 2005 was produced by the failure of the neoliberal policies carried out in this region during the period following the debt crisis of the eighties. Showing data that reveal that the bolivian economic performance in the neoliberal period was better compared to the performance of Argentina, Brazil and Mexico, this article offers an alternative explanation, which not denying the poverty of the bolivian majorities, asserts that the breakdown of the political system and the parties that alternated in power for twenty years is the main factor explaining the rise of the first indigenous president.

  4. A “pessoa” de Rudder Baker é realmente incorporada?

    Directory of Open Access Journals (Sweden)

    Jonas Gonçalves Coelho

    2008-06-01

    Full Text Available Some philosophers materialists think, against the dualism of substance, that an embodied mind is only a mind that depends on a body to exist, that is, that the mind doesn’t exist independently of a body. I will take as representative of this very limited point of view about embodiment the ideas of Lynne Baker and her Constitution View. Baker says that she prefers to face the problem of the relationship between persons and bodies than the problem of the relationship between mind and body because this last formulation of the problem implies the idea of a mind distinct and separated of the body while the first is more according of her view of an embodied and situated mind. But the problem is that Baker forgets it when she defines persons in terms of first-person perspective or self-consciousness. Although, Baker says that the self-consciousness depends on structural – a body – and environmental – the situation – conditions, what becomes a self-conscious human person an entity ontologically distinct of the body that constitutes it and of other animals are their realizations like arts, philosophy, science, moral, etc. It looks like that for Baker the self-consciousness is not only a necessary condition but also a sufficient one for that human realizations, while the body fulfill only an indirect role. Against these ideas we can ask: the great realizations that distinguish the human persons of other animals would be possible independently of the biological constitution of our body and its needs?

  5. El asunto del “Nuestra señora de la Mercedes” (Odyssey

    Directory of Open Access Journals (Sweden)

    F. Jesús Carrera Hernández

    2009-01-01

    Full Text Available Este trabajo constituye, básicamente, una valoración del informe emitido en Estados Unidos por el Juez Pizzo en el que ya podemos calificar como asunto del “Nuestra Señora de La Mercedes”, iniciado hace dos años tras las actividades de expolio desarrolladas por la empresa Odyssey en aguas del Atlántico próximas al Estrecho de Gibraltar. Se trata de un caso que afecta directamente a los intereses españoles en relación con el patrimonio cultural submarino situado en zonas próximas a nuestras costas. De convertirse en jurisprudencia, estaremos dando un paso más en aras de la protección del patrimonio cultural, soslayando la aplicación de legislaciones ancladas enla aplicación de principios de salvamento y hallazgos a bienes que poseen un valor arqueológico, histórico o cultural, y que se encuentran en santuarios de nuestros antepasados.

  6. Phase diagram of Se-CaIn4Se7 system

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  7. Variational approach to 68 Se

    International Nuclear Information System (INIS)

    Petrovici, A.; Schmid, K.W.; Faessler, A.; Baktash, C.; Shashi, P.

    1999-01-01

    . Furthermore, our results concerning the pair structure of the wave functions of the even-spin states in chains of even-even and odd-odd N = Z nuclei in the A 60 - 80 mass region revealed a clear interplay between isovector neutron-proton and like-nucleon pairing correlations. Nevertheless, detailed aspects of these properties are sensitive to the renormalization of the effective interaction in the pairing channels. Taking advantage of our microscopic investigations on the coexistence phenomena in this mass region, which have already past many experimental tests, we address the problem of the structure of the lowest few even-spin positive-parity states in 68 Se. Also we present details of the results obtained using a few slightly different prescriptions for the effective interaction in order to illustrate the above mentioned problems. The theoretical spectrum of 68 Se for even spin positive parity states is compared with the experimental results. (authors)

  8. "2por km2" chozos, estructuras y corrales de piedra en seco en la superficie del término de Tebar, Cuenca

    OpenAIRE

    Ruiz Checa, José Ramón; Cristini, Valentina

    2011-01-01

    [ES] Tanto en la península Ibérica (Maestrazgo... Islas Baleares...), como en Europa (Provenza... Liguria...) aparecen «paisajes construidos» con piedra en seco. Se trata realmente de parajes antropizados prácticamente en toda su totalidad, resultado de un afán milenario de domesticación del territorio, a través de estructuras hidráulicas, pistas, cañadas...caminos, bancales, construcciones o recintos. El caso de Tébar, un municipio a 94 km al sur oeste de Cuenca, e...

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  10. Cómo las superheroínas se convirtieron en amas de casa: Pixar y 'Los Increíbles'

    OpenAIRE

    Mínguez López, Xavier

    2012-01-01

    Pixar representa para buena parte de su público una renovación de la animación en los términos que nos presentaba Disney tradicionalmente. Sin embargo, bien sea por la dependencia de la multinacional americana, bien sea porque no existe una reflexión en profundidad respecto a la transmisión de valores, Pixar continúa lanzando mensajes conservadores, especialmente, cuando se trata de los roles de mujeres y hombres. En este artículo analizamos algunas de sus películas centrándonos especialmente...

  11. Todo se dice en música: La presencia de la estética romántica en la prensa musical porteña (Buenos Aires, 1837- 1838

    Directory of Open Access Journals (Sweden)

    Guillermina Guillamón

    2016-06-01

    Full Text Available El presente trabajo busca indagar en torno a la función social, política y estética que se le atribuye a la música en el diario Boletín Musical (1837 y en La Moda (1837-38. La hipótesis que guía la investigación está orientada a pensar que, valiéndose del romanticismo como paradigma de pensamiento, los diarios erigieron a la música como una práctica inclusiva, al alcance de la totalidad del pueblo, el cual se consideraba destinatario de un programa civilizador impulsado por la “nueva generación romántica”. Al discutir muchos de los supuestos de la ilustración, en tanto ideario que consideraron obsoleto, lo que realmente estaban haciendo era cuestionar los limitados alcances de las políticas culturales del gobierno precedente y, derivado de ello, afirmar su apoyo al gobernador actual, Juan Manuel de Rosas.

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

    Science.gov (United States)

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

    2009-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Abe Seishi

    2011-01-01

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

  14. Cs2UPd3Se6

    Directory of Open Access Journals (Sweden)

    George N. Oh

    2011-02-01

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

  15. C-type Nd2Se3

    Directory of Open Access Journals (Sweden)

    2009-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-15

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

  17. Tornar-se negro: trajetÃrias de vida de professores universitÃrios no CearÃ

    OpenAIRE

    Maria Auxiliadora de Paula GonÃalves Holanda

    2009-01-01

    A pesquisa trata dos processos de construÃÃo de subjetividades dos professores universitÃrios negros da Universidade Federal do Cearà (UFC) ao longo de suas trajetÃrias de vida. O caminho percorrido rumo ao objeto de anÃlise foi conhecer e analisar as construÃÃes identitÃrias de professores dessa universidade nas experiÃncias do tornar-se negro, vivenciadas desde a infÃncia atà o ingresso no mundo do trabalho, no contÃnuo processo de identificaÃÃo e negociaÃÃo prÃprio da formaÃÃo humana. O fo...

  18. DIBUJAR(SE FRENTE AL FUTURO. Hacia una sociología del dibujo escolar

    Directory of Open Access Journals (Sweden)

    Tatiana Beirute

    2011-11-01

    Full Text Available Este trabajo trata de descubrir la lógica implícita en las prácticas sociales naturalizadas mediante la presentación de unanálisis sociológico de los dibujos. Es parte de un proyecto de mayor envergadura titulado “La mujer y la ciencia” que tratóde responder a preguntas como: ¿Qué es la relación entre la ciencia y de género? ¿Cuál es la relación entre la ciencia y laclase social? ¿Cuál es la relación entre la ciencia, la razón y el poder?. Se presenta el análisis que se derivan de pedir a losestudiosos se proyecta hacia el futuro y la respuesta a la pregunta “¿Qué quiero ser cuando crezca?”. Este análisis sugiere quelas desigualdades que experimentan diversos estudiosos de su vida, conduce a una relación muy estrecha entre la clase social,la ciencia y la razón. Esto puede ser visto no sólo en la forma en que las clases se les enseña, sino que también se refleja enlos sueños y las aspiraciones de los niños, que a pesar de su corta edad, se reproducen sus condiciones sociales, y en el casode los niños de baja condición socioeconómica , que la experiencia de sus vidas llevando el peso de sus propias circunstanciasy contextos. La ideología que legitima la desigualdad se internaliza desde la edad escolar. En ese sentido, los niños puedenser ideológicos “transmisores” de la desigualdad y exclusion.education y las demandas sociales exigen que las universidadespúblicas adecuadas oferta curricular flexible de las necesidades

  19. CUANDO EL DESARROLLO SOCIAL SE HACE POSIBLE EN UN PAÍS POBRE: EL CASO DE COSTA RICA

    Directory of Open Access Journals (Sweden)

    Leonardo Garnier Rímolo

    2011-09-01

    Full Text Available Este artículo es una versión ligeramente modificada de un trabajo escrito a finales de 1994 a solicitud del Fondo de las Naciones Unidas para la Infancia (UNICEF, para ser incluido en una publicación que contendrá los análisis retrospectivos de los procesos de desarrollo social de varios países en desarrollo. Se trata de países que, como Costa Rica, han logrado avances significativos en los niveles de bienestar de sus poblaciones, a pesar de sus históricas limitaciones estructurales.La principal pregunta que se busca contestar en el artículo se podría plantear de la siguiente manera: ¿cómo fue posible que ese pequeño país que es Costa Rica, con una economía típica del capitalismo periférico, pudiera alcanzar niveles de calidad de vida más cercanos a los de los países industrializados que a los de los países en desarrollo, a pesar de que el producto económico que genera no supera el nivel medio-bajo en el contexto internacional?Para abordar esa cuestión, se ofrece una interpretación de los rasgos esenciales del proceso de desarrollo social que ha experimentado el país desde la mitad del siglo veinte hasta principios de la década de los noventa. También se analizan los factores que han hecho posible ese proceso, se resaltan los principales instrumentos institucionales que lo han impulsado, y se discute sobre su sostenibilidad futura.

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

    International Nuclear Information System (INIS)

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

    1977-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Hosni, H.M.M.A.

    2010-01-01

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

  3. La Víctima de Trata Sexual y su Des-protección en la Ley Integral contra la Violencia de Género 1/2004 (The Sexual Trafficking Victims and Des-protection in the Law Against Gender Violence 1/2004

    Directory of Open Access Journals (Sweden)

    Izaskun Orbegozo

    2015-06-01

    Full Text Available In this article I make a reflection about the art. 1 L0 1/2004 of 28 December of integral Protection Measures against Gender Violence (law 1/2004 and its relations with sexual trafficking victims, who are absent in these regulation, and as a result any kind of protection.Taking into an account, the most important international instruments aiming at the elimination of violence against women, I am going to focus on sexual trafficking victims and gender violence from the point of view of criminology and victimology, and finally, on the meaning of violence gender from different perspectives, making an special mention to the concept regulated in the article 1 of the integral 1/2004. En el presente artículo realizo una reflexión sobre el art. 1 de la L0 1/2004, de 28 de diciembre, de medidas de Protección integral contra la violencia de género (en adelante ley integral 1/2004 y su relación con las víctimas de trata sexual, ausentes en dicha normativa, y por consiguiente, carentes de protección. Partiendo de los instrumentos internacionales más relevantes que tienen por finalidad la eliminación de la violencia contra la mujer, me centraré en la víctima de trata sexual como violencia de género desde un punto de vista criminológico y victimológico, y finalmente, abordaré el significado de violencia de género desde diversas perspectivas, haciendo mención especial al concepto regulado en el art.1 de la ley integral 1/2004. DOWNLOAD THIS PAPER FROM SSRN: http://ssrn.com/abstract=2612021

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  5. Como Perseu se defendeu de Medusa?

    Directory of Open Access Journals (Sweden)

    Rose Lumertz de Freitas

    2012-04-01

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

  6. Solving the shape conundrum in $^{70}$Se

    CERN Multimedia

    We propose a multi-step Coulomb-excitation study of $^{70}$Se at HIE-ISOLDE using the $^{208}$Pb( $^{70}$Se, $^{70}$Se*)$^{208}$Pb* reaction at a safe energy of 5.0 MeV/u. We aim at a precise measurement of the $\\left \\langle 2^{+}_{1} \\hspace{0.1cm} || \\hspace{0.1cm}\\hat{E}2 \\hspace{0.1cm} || \\hspace{0.1cm}2^{+}_{ 1} \\right \\rangle$ diagonal matrix element as well as gaining information on additional matrix elements. Such information will shed light onto the shape conundrum of the 2$^{+}_{1}$ state in $^{70}$Se as well as foreseeing the opportunity for a more detailed understanding of the shape-coexistence phenomenon in this region.

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

    Science.gov (United States)

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

    2018-03-01

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

  8. Lustre filesystem for CMS storage element (SE)

    International Nuclear Information System (INIS)

    Wu, Y; Kim, B; Avery, P; Fu, Y; Bourilkov, D; Taylor, C; Prescott, C; Rodriguez, J

    2011-01-01

    This paper presents our effort to integrate the Lustre filesystem with BeStMan, GridFTP and Ganglia to make it a fully functional WLCG SE (Storage Element). We first describe the configuration of our Lustre filesystem at the University of Florida and our integration process. We then present benchmark performance figures and IO rates from the CMS analysis jobs and the WAN data transfer performance that are conducted on the Lustre SE.

  9. The system SnTe-InSe

    International Nuclear Information System (INIS)

    Gurshumov, A.P.; Alidzhanov, M.A.; Aliev, A.S.; Gadzhiev, T.G.; Mamedov, N.A.

    1986-01-01

    This paper discusses the nature of the interaction and physicochemical properties of the alloys of the system SnTe-InSe. The DTA was performed on an NTR-74 pyrometer, XPA on a Dron-2.0 diffractometer and MSA on an MIM-7 metallographic microscope. The microhardness of the samples was determined on a PMT-3 microhardness tester. The congruently melting compound SnInTeSe and solid solutions based on the starting components are formed in the system

  10. Los jóvenes se incomunican

    Directory of Open Access Journals (Sweden)

    Margarita Ferro

    2015-01-01

    Full Text Available Hace años los jóvenes se comunicaban y relacionaban con sus amigos del barrio o de la escuela por lo que desde pequeños desarrollaban una comunicación interpersonal fluida. Hoy los video-juegos han sustituido la amistad y se han transformado en elementos de la comunicación. La autora analiza el mundo del nintendo y su influencia en las personas

  11. Jugando se entiende la gente. Una propuesta didáctica para la inclusión de las unidades fraseológicas en el aula de E/LE

    Directory of Open Access Journals (Sweden)

    Alicia Merino González

    2015-10-01

    Full Text Available La enseñanza de unidades fraseológicas en el aula de E/LE suscita controversia, así pues, en este artículo se pretende presentar una actividad que permita a los alumnos participar en el aprendizaje de estas unidades. Se trata de la introducción y refuerzo de fraseologismos mediante un juego adaptado llamado TriviELE. Hay cuatro categorías en las que el alumno deberá realizar asociaciones y escenificar diálogos donde aparezca el fraseologismo o su paráfrasis. En concreto se trata de locuciones con somatismos o con nombre de animal incluidas en una actividad dirigida a alumnos del nivel B2, con la finalidad de que se practique en clase la conversación coloquial y la utilización de las unidades fraseológicas en esta. De este modo, mediante la adquisición de estas unidades el alumno logrará fluidez y precisión en su comunicación.

  12. English Textbooks for Teaching and Learning English as a Foreign Language: Do They Really Help to Develop Communicative Competence? Textos en inglés para el aprendizaje y la enseñanza del inglés como lengua extranjera: ¿realmente ayudan a desarrollar la competencia comunicativa? Textos em inglês para a aprendizagem e o ensino de inglês como língua estrangeira: eles realmente ajudam a desenvolver habilidades de comunicação?

    Directory of Open Access Journals (Sweden)

    Luis Fernando Gómez-Rodríguez

    2010-12-01

    Full Text Available Communicative texts are educational materials for language learning that focus on the genuine use of a language for communicative purposes in a variety of meaningful contexts. Above and beyond the mere study of linguistic forms, these texts offer opportunities to communicate, interact and negotiate meaning. Three common types of English language practice are analyzed in this article: mechanical practice, meaningful practice and communicative practice. Five English texts representative of those currently used in Colombia were selected to determine to what degree they include genuine communicative tasks and, in this respect, how they encourage the development of communicative competence. The extent of communicative practice these texts offer students of English was found to be less than the amount of mechanical and meaningful practice. This information should be useful for training English teachers, particularly those who generally focus their classroom activity on the use of texts. Methodological suggestions are offered, based on the results of the study.Los textos comunicativos son una clase de material didáctico para el aprendizaje de las lenguas, que presentan uso real del lenguaje con propósitos comunicativos, dentro de una gran variedad de contextos significativos. Ofrecen oportunidades de comunicación, interacción y negociación de significado, más que el simple estudio deformas lingüísticas. En el artículo se analizan tres tipos comunes de práctica de la lengua inglesa:práctica mecánica, práctica significativa y práctica comunicativa. Se escogieron cinco textos representativos de inglés, que en la actualidad se implementan en Colombia, con elfin de determinar hasta qué punto incluyen tareas comunicativas auténticas, y en este sentido, cómo fomentan el desarrollo de la competencia comunicativa. Se demostró que el nivel de práctica comunicativa que tales textos ofrecen a los estudiantes de inglés es inferior a las pr

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

    International Nuclear Information System (INIS)

    Wang Ke; Hou Xiaolin

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  17. ¿ Como se hace una Telenovela ?

    Directory of Open Access Journals (Sweden)

    Iván Gavaldón

    2015-01-01

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

  18. As disputas de cortesia no espaço urbano: Quando a cortesia se transforma em violência

    Directory of Open Access Journals (Sweden)

    Carole Gayet-Viaud

    2008-07-01

    Full Text Available O artigo analisa, por meio da descrição de uma pesquisa etnográfica de cinco anos em uma vizinhança de Paris, França, um tipo específico de situação estabelecida nas relações entre atores na vida pública de uma grande cidade, aquelas chamadas aqui de “disputas de cortesia”. Trata-se daquele momento em que pessoas que não se conhecem põem-se a discutir por conta de algum discurso em sinal de reprovação apresentado por uma das partes e, devido a uma polêmica em torno de uma demanda de cortesia, podem chegar ao enfrentamento. The article Courtesy disputes in urban space: When courtesy becomes violence analyses, by the description of a five-year ethnography in a French neighborhood, the “courtesy dispute”, a specific type of situation established on the relations between actors in a big city public life. “Courtesy dispute” refers to the moment when people who don’t know each other start an argument because of a criticism made by another part and, motivated by a demand for courtesy, may follow towards violence.

  19. PbSe Nanocrystal Excitonic Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2009-11-11

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

  20. Se luchaba por sacar adelante a un ser humano enfrentado a una enfermedad

    Directory of Open Access Journals (Sweden)

    Sergio R. López Alonso

    2015-06-01

    Full Text Available Entrevista realizada a Cristina González García, Capitán Enfermera de Vuelo destinada en la Unidad Médica de Aeroevacuación del ejército del Aire, sita en la Base Aérea de Torrejón de Ardoz en Madrid. Su misión se centra en la evacuación aérea internacional de pacientes y es responsable del área de entrenamiento y simulación de los equipos multidisciplinares sanitarios. Su experiencia en el traslado y en el cuidado durante la repatriación desde Liberia de los hermanos de la Orden Hospitalaria "San Juan de Dios" Miguel Pajares Martín y Manuel García Viejo, afectos de ébola, la convierten en un referente nacional e internacional. En el contenido de la entrevista, la Capitán Enfermera trata el papel de las enfermeras en el ejército, los preparativos para el transporte aéreo de personas con ébola, la formación previa, las circunstancias encontradas en destino, la relación con las personas afectadas, su aprendizaje de la experiencia, la opinión social y el caso de Teresa Romero.

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-28

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

  3. Lattice thermal conductivity of LaSe

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei, E-mail: tolwwt@163.com [School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Pan, Zhong-liang; Chen, Jun-fang; He, Qin-yu [School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Wang, Teng [School of Computer, South China Normal University, 510631 Guangzhou (China)

    2015-07-15

    The phonon dispersions and phonon density of states of LaSe are obtained, based on density functional perturbation theory and the norm-conserving pseudo-potential method. An anomaly in calculated phonon dispersion curves is presented and interpreted as a Kohn anomaly. The heat capacity of LaSe is calculated then. For the three-phonon process scattering, the lowest non-harmonic cubic terms of the interatomic potential are considered to obtain single-phonon relaxation rate by applying the Fermi's golden rule. For the boundary scattering, the average phonon relaxation time was obtained. Considering two kinds of phonon scattering mechanisms, we obtain the lattice thermal conductivity of LaSe.

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

    Science.gov (United States)

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

    2016-07-01

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

  5. Los cócs: una seña de identidad de la Terra Alta

    Directory of Open Access Journals (Sweden)

    Maria Del Loreto Meix

    2004-04-01

    Full Text Available Este artículo trata sobre la repostería tradicional de la comarca de la Terra Alta (Cataluña vinculada a las fiestas, especialmente sobre las pastas que se suelen hacer en dicha comarca. En esta zona las pastas se llaman cócs, una palabra que está presente tanto en la Terra Alta como en las comarcas vecinas de la Ribera d'Ebre o el Priorat. Junto con las pastas se sirve el vino rancio, la mistela o el vino dulce, que también son productos de estas tierras. Actualmente, panaderías y pastelerías de los pueblos de la comarca elaboran estos productos tradicionales artesanos, que en otras épocas sólo se hacían en casa.El artículo, que nace del trabajo de final de carrera realizado por la autora para la licenciatura de Humanidades de la UOC, aporta una visión privilegiada de la riqueza de la Terra Alta con respecto a su historia gastronómica, sus costumbres y la manera de tratar sus dulces. La autora, que ya había trabajado anteriormente en estos aspectos, sitúa las especificidades de la repostería tradicional terraltina en el contexto de las culturas mediterráneas con raíces comunes que se remontan al mundo antiguo y medieval y que todavía mantienen un "aire de familia" bien identificable; a la vez, recorre por la zona, con interés etnográfico, lo que denomina "el mundo del trigo" (la amasadura del pan, el oficio de panadero, los hornos y otras herramientas, las tradiciones asociadas.... En definitiva, rescata un aspecto vivo de la cotidianidad local y lo sitúa a la luz de la historia de la alimentación, mientras aporta información que puede ser de interés desde otros ángulos de estudio.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

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

    Science.gov (United States)

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

    2016-10-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  9. No todo lo que cuenta se cuenta

    NARCIS (Netherlands)

    van Rijckevorsel, J.

    2008-01-01

    En este trabajo publicado en "Insurance Economics" Nº 58 (Julio 2008), Jan van Rijckevorsel hace un profundo análisis del uso práctico de las estadísticas de seguros aplicadas a aspectos reales del quehacer institucional del sector, y señala varios campos (como el valor y calificación de la

  10. Properties and Bibliography of GaSe

    Science.gov (United States)

    1994-02-01

    Musaev, A. E. Bakhyshev, N. M. Gasanly and L. G. Musaeva . (1975). "Anisotropy of the optical constants of GaS and GaSe near the absorption edge." Sov...Phys. Semiconductors. 9 94-95 Russian ref.: Fiz. Tekh. Poluprovodn. 9 142-145 (January 1975). Akhundov, G. A., L. G. Musaeva and M. D. Khomutova

  11. VerSeDa: vertebrate secretome database.

    Science.gov (United States)

    Cortazar, Ana R; Oguiza, José A; Aransay, Ana M; Lavín, José L

    2017-01-01

    Based on the current tools, de novo secretome (full set of proteins secreted by an organism) prediction is a time consuming bioinformatic task that requires a multifactorial analysis in order to obtain reliable in silico predictions. Hence, to accelerate this process and offer researchers a reliable repository where secretome information can be obtained for vertebrates and model organisms, we have developed VerSeDa (Vertebrate Secretome Database). This freely available database stores information about proteins that are predicted to be secreted through the classical and non-classical mechanisms, for the wide range of vertebrate species deposited at the NCBI, UCSC and ENSEMBL sites. To our knowledge, VerSeDa is the only state-of-the-art database designed to store secretome data from multiple vertebrate genomes, thus, saving an important amount of time spent in the prediction of protein features that can be retrieved from this repository directly. VerSeDa is freely available at http://genomics.cicbiogune.es/VerSeDa/index.php. © The Author(s) 2017. Published by Oxford University Press.

  12. Det faderløse samfund

    DEFF Research Database (Denmark)

    Jensen, Henrik

    Det faderløse samfund er en kulturhistorisk afdækning af fader- og autoritetstabet i det 20. århundredes Europa, med fokus på fader-søn-forholdet og fortalt gennem skikkelser som Max Weber, Freud, Jung, Kafka - og ’den uregerlige søn’ over dem alle, psykologen og anarkisten Otto Gross. Den er...

  13. Señales en el agua

    Directory of Open Access Journals (Sweden)

    Helcías Martan Góngora

    1964-11-01

    Full Text Available La lluvia fue siempre compañera de la soledad. En su ámbito de música se mueve el pensamiento con monótono ritmo y el alma encuentra su centro de gravedad, mientras dura el imperio de su amada caricia.

  14. ¿Cómo se concibe la etnografía crítica dentro de la investigación cualitativa?

    Directory of Open Access Journals (Sweden)

    Ileana Vargas-Jiménez

    2016-05-01

    Full Text Available Recibido 3 de mayo de 2015 • Corregido 7 de setiembre de 2015 • Aceptado 3 de noviembre de 2015 El artículo intenta, en una primera instancia, acercarse a señalar qué es la investigación cualitativa;  posteriormente, se considera con más detalle,  a través de la reflexión,  la vinculación de  la etnografía. Para ello se mencionan los fundamentos y el origen de esta, luego se presentan los resultados de varias investigaciones así como  se señalan algunas líneas de investigación desde la etnografía crítica. Interesa rescatar, dentro de la búsqueda bibliográfica que se llevó a cabo, un caso que ilustra en qué consiste la etnografía crítica y de qué manera se vincula con la investigación. Entre las principales conclusiones se destaca que la etnografía crítica no es solamente escuchar de manera crítica y reflexiva las denuncias, sino denunciar, vehementemente, pero respetando las voces y los planteamientos: esto es lo que la etnografía crítica trata de rescatar desde las voces de sus participantes a través de sus relatos y experiencias.

  15. Cómo las superheroínas se convirtieron en amas de casa: Pixar y “Los Increíbles” / How superheroines became housewifes: Pixar and “The Incredibles”

    OpenAIRE

    Xavier Mínguez López

    2012-01-01

    Resumen: Pixar representa para buena parte de su público una renovación de la animación en los términos que nos presentaba Disney tradicionalmente. Sin embargo, bien sea por la dependencia de la multinacional americana, bien sea porque no existe una reflexión en profundidad respecto a la transmisión de valores, Pixar continúa lanzando mensajes conservadores, especialmente, cuando se trata de los roles de mujeres y hombres. En este artículo analizamos algunas de sus películas centrándonos espe...

  16. Especificidad de la educación de adultos. b a s e s psicopedagógicas y señas de identidad

    Directory of Open Access Journals (Sweden)

    Óscar Medina Fernández

    2000-01-01

    Full Text Available Se plantean en este trabajo las bases psicopedagógicas de la educación de adultos y, a partir de ahí, se aborda el problema del carácter específico de este sector educativo. El autor trata de defender que, basándonos en la investigación psicológica que actualmente tenemos disponible, y haciendo uso de determinados conocimientos pedagógicos, existe base para fundamentar algunos aspectos del carácter específico de la educación de adultos como un tipo de educación propia que se diferencia de lo que habitualmente se realiza en las escuelas para niños y adolescentes. En la medida en que las señas de identidad de esa educación de adultos específica son eminentemente sociales, podemos afirmar que estamos ante un campo de la educación cuyo marco teórico más amplio es el de la Pedagogía Social

  17. Absorption Spectra of CuGaSe2 and CuInSe2 Semiconducting Nanoclusters

    KAUST Repository

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Gómez del Estal Villarino, Mario

    2011-03-01

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

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  1. Anisotropy in CdSe quantum rods

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liang-shi [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    The size-dependent optical and electronic properties of semiconductor nanocrystals have drawn much attention in the past decade, and have been very well understood for spherical ones. The advent of the synthetic methods to make rod-like CdSe nanocrystals with wurtzite structure has offered us a new opportunity to study their properties as functions of their shape. This dissertation includes three main parts: synthesis of CdSe nanorods with tightly controlled widths and lengths, their optical and dielectric properties, and their large-scale assembly, all of which are either directly or indirectly caused by the uniaxial crystallographic structure of wurtzite CdSe. The hexagonal wurtzite structure is believed to be the primary reason for the growth of CdSe nanorods. It represents itself in the kinetic stabilization of the rod-like particles over the spherical ones in the presence of phosphonic acids. By varying the composition of the surfactant mixture used for synthesis we have achieved tight control of the widths and lengths of the nanorods. The synthesis of monodisperse CdSe nanorods enables us to systematically study their size-dependent properties. For example, room temperature single particle fluorescence spectroscopy has shown that nanorods emit linearly polarized photoluminescence. Theoretical calculations have shown that it is due to the crossing between the two highest occupied electronic levels with increasing aspect ratio. We also measured the permanent electric dipole moment of the nanorods with transient electric birefringence technique. Experimental results on nanorods with different sizes show that the dipole moment is linear to the particle volume, indicating that it originates from the non-centrosymmetric hexagonal lattice. The elongation of the nanocrystals also results in the anisotropic inter-particle interaction. One of the consequences is the formation of liquid crystalline phases when the nanorods are dispersed in solvent to a high enough

  2. Explaining the Principle of Mala in Se

    DEFF Research Database (Denmark)

    Dige, Morten

    2012-01-01

    Certain methods and weapons are traditionally considered to be "mala in se", i.e. evil in themselves. Examples are mass rape campaigns and land mines. The article examines different interpretations of the principle that belligerents ought not to use such means. Some interpretations are reductionist...... in the sense that they see the principle as an instance of other principles regulating conduct in war (jus in bello), namely the principles of discrimination and proportionality. I suggest a horizontal and a vertical dimension of the latter. Resort to violence can then be unjustified if 1) the persons......-one should have to endure. I defend the vertical dimension of proportionality as a key to understanding the principle of mala in se and consider whether it leads to an absolute prohibition against such means...

  3. Magnetothermoelectric properties of Bi2Se3

    Science.gov (United States)

    Fauqué, Benoît; Butch, Nicholas P.; Syers, Paul; Paglione, Johnpierre; Wiedmann, Steffen; Collaudin, Aurélie; Grena, Benjamin; Zeitler, Uli; Behnia, Kamran

    2013-01-01

    We present a study of entropy transport in Bi2Se3 at low temperatures and high magnetic fields. In the zero-temperature limit, the magnitude of the Seebeck coefficient quantitatively tracks the Fermi temperature of the three-dimensional Fermi surface at the Γ point as the carrier concentration changes by two orders of magnitude (1017 to 1019 cm-3). In high magnetic fields, the Nernst response displays giant quantum oscillations indicating that this feature is not exclusive to compensated semimetals. A comprehensive analysis of the Landau level spectrum firmly establishes a large g factor in this material and a substantial decrease of the Fermi energy with increasing magnetic field across the quantum limit. Thus, the presence of bulk carriers significantly affects the spectrum of the intensively debated surface states in Bi2Se3 and related materials.

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

    International Nuclear Information System (INIS)

    Deniozou, T.

    2005-01-01

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

  5. Synthèse et spectroscopie IR:

    African Journals Online (AJOL)

    BUREAU

    Synthèse de HCs5P2W18O62.16H2O et application à l'adsorption de la matière ... Résumé. La présente étude porte sur l'adsorption d'un colorant, le bleu de méthylène (BM), par un hétéropolyanion saturé ..... Adsorption of a gas mixture on ...

  6. Double beta decay of 82Se

    International Nuclear Information System (INIS)

    Elliott, S.R.; Hahn, A.A.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1992-01-01

    The two-neutrino double beta decay of 82 Se has been measured during a 20 244 h run resulting in a half-life of 1.08 -0.06 +0.26 x10 20 years (68% C.L.). No candidate events for the zero-neutrino double beta decay during 21 924 h results in a half-life limit of 2.7x10 22 years at the 68% confidence level

  7. Thermoelectric properties of SnSe compound

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Xinhong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Lu, Pengfei, E-mail: photon@bupt.edu.cn [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Wu, Liyuan; Han, Lihong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Liu, Gang [School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Song, Yuxin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Photonics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Gothenburg (Sweden)

    2015-09-15

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data.

  8. Experience with the SE in Germany

    Directory of Open Access Journals (Sweden)

    Jochem Reichert

    2008-03-01

    Full Text Available A rather significant proportion of the Societas Europaeas (the European Company, or SE formed to date have had German roots. German corporate law has been enriched by an interesting alternative which meanwhile seems to have gained momentum. This contribution focuses on SEs incorporated by German entrepreneurs and provides an interesting account concerning the use of SEs in Germany in practice, such as Allianz, Fresenius, BASF and Porsche. Has the SE been used to circumvent rigid company law provisions or is it a more flexible and effective tool, perhaps, for company mobility? The practical motives behind setting up this company form are also reflected upon. These include: the facilitation of cross-border mergers; transfer of the registered office; the ‘European’ image; a more flexible form of co-determination in large companies (reduction of the number of supervisory board members; avoidance and freezing of co-determination for medium-sized enterprises; the appeal of the one-tier system and its endangerment by German co-determination; and flat and uniform structures for company groups. The author also briefly discusses some of the problems arising from the formation of SEs in Germany. He ultimately concludes that practice has shown that it is possible to work with the legal regime of the SE in Germany, which adds a new company form to those available in that Member State.

  9. Thermoelectric properties of SnSe compound

    International Nuclear Information System (INIS)

    Guan, Xinhong; Lu, Pengfei; Wu, Liyuan; Han, Lihong; Liu, Gang; Song, Yuxin; Wang, Shumin

    2015-01-01

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data

  10. Forming Glasses from Se and Te

    Directory of Open Access Journals (Sweden)

    Pierre Lucas

    2009-10-01

    Full Text Available Despite being close neighbors on the Periodic Table, selenium and tellurium present a totally different abilities to form glasses. Se is a very good glass former, and gives rise to numerous glass compositions which are popular for their transparency in the infrared range and their stability against crystallization. These glasses can be shaped into sophisticated optical devices such as optical fibers, planar guides or lenses. Nevertheless, their transparencies are limited at about 12 μm (depending on the thickness of the optical systems due to the relatively small mass of the Se element. On the other hand, tellurium is heavier and its use in substitution for Se permits to shift the IR cutoff beyond 20 μm. However, the semimetallic nature of Te limits its glass formation ability and this glass family is known to be unstable and consequently has found application as phase change material in the Digital Versatile Disk (DVD technology. In this paper, after a review of selenide glasses and their applications, it will be shown how, in a recent past, it has been possible to stabilize tellurium glasses by introducing new elements like Ga or I in their compositions.

  11. Qué se sabe de bullying

    Directory of Open Access Journals (Sweden)

    B. Ricardo Musalem, Ps.

    2015-01-01

    Full Text Available Se define bullying como una dinámica de maltrato sistemática que ocurre entre iguales de manera persistente. Es considerado un problema de salud pública debido a su prevalencia y las consecuencias que tiene en todos sus participantes: en los agresores, en las víctimas, en los espectadores, en los padres y familias, en la comunidad escolar y en la sociedad en general. Las investigaciones muestran efectos a corto, mediano y largo plazo en el desarrollo emocional y social de niños y adolescentes. Se ha constatado una relación del acoso escolar con las patologías físicas, psicosomática y de salud mental en niños, adolescentes y en la vida adulta. En este artículo se describen las características individuales, las relacionales, los factores conocidos como de riesgo y factores protectores, la prevalencia y los programas de abordaje integral del fenómeno. Son múltiples los estudios que muestran la efectividad de la aplicación de estos programas de intervención, diseñados en función de los conocimientos acumulados.

  12. Patrimonio cultural: lo intangible se hace tangible

    Directory of Open Access Journals (Sweden)

    William Heredia Orjuela

    2004-11-01

    Full Text Available Se presentan tres reflexiones a manera de ensayo, elaboradas por estudiantes de vii semestre de la Facultad de Administración de Empresas Turísticas y Hoteleras. El tema central que engloba los escritos es el de la responsabilidad frente al patrimonio cultural, su valoración y su relación con el turismo. En el ensayo La protección del patrimonio cultural como reflejo del ser humano, la estudiante cecilia hinosTrosa hace un llamado de atención frente al problema del tráfico ilícito de bienes que conlleva la pérdida de testimonios de la cultura humana. El escrito de la estudiante mariel cecilia hernández destaca las bondades de recuperar las tradiciones y de cómo éstas se pueden difundir a través del turismo. Por último, el estudiante William heredia hace una reflexión sobre la tangibilidad de lo intangible, en el ensayo Patrimonio Cultural: lo tangible se hace intangible, donde destaca la declaratoria del Carnaval de Barranquilla como patrimonio oral e intangible de la humanidad.

  13. Todavía hoy se puede preguntar: ¿por qué pelearon sartre y camus?

    Directory of Open Access Journals (Sweden)

    Rubén Maldonado Ortega

    2007-01-01

    Full Text Available Se trata de una reflexión sobre la degradación de la protesta humana, manifiesta con la práctica del terrorismo, promocionado este como estrategia legítima para la obtención de “dividendos políticos”. Dicha reflexión se hace a partir de una actualización de los referentes conceptuales y políticos que llevaron a Jean Paul Sartre y Albert Camus a sostener una agria polémica en la década de los cincuenta, en la que debatieron sus ideas sobre la historia. Dicha polémica los colocó en posiciones teóricas contrapuestas sobre la idea de la historia, acabando con una amistad de más de diez años. La profundidad de esa discusión, el acopio argumentativo de que echaron mano y el apasionamiento con que fue llevada a cabo constituyen un invaluable marco de referencia para reexaminar, en el contexto de la historia contemporánea, la comprensión del fenómeno de la acción política legítima y la amenaza del terror para la civilización

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

    Science.gov (United States)

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

    2018-02-01

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

  15. Absorption Spectra of CuGaSe2 and CuInSe2 Semiconducting Nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2015-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-17

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  20. Symmetry effects in neutron scattering from isotopically enriched Se isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J.; Haouat, G.; McEllistrem, M. T.; Patin, Y.; Sigaud, J.; Cocu, F.

    1975-06-01

    Differential cross sections for neutron elastic and inelastic scattering from {sup 76}Se, {sup 78}Se, {sup 80}Se and {sup 82}Se, have been measured at 8-MeV incident neutron energy and from {sup 76}Se and {sup 82}Se at 6- and 10-MeV incident energies. The differences observed in the elastic scattering cross sections are interpretable as the effects of isospin term in the scattering potentials. A full analysis of the elastic scattering data are presented.

  1. ¿Es redundante la prueba de selectividad?.

    Directory of Open Access Journals (Sweden)

    Rúa Vieytes, Antonio.

    2003-01-01

    Full Text Available Como consecuencia de la futura reforma en las pruebas de acceso a la universidad española, en donde la principal novedad será la eliminación de la prueba de conjunto o selectividad, cabe reflexionar sobre tan controvertida prueba y preguntarnos si realmente dicha prueba ha servido para algo y su aplicación ha sido efectiva en el rendimiento del alumno una vez dentro de la universidad o, por el contrario, si se trata de una prueba redundante. A partir del expediente académico y de las notas de selectividad de una muestra de 2.500 alumnos durante siete años, se llevará a cabo un análisis econométrico del grado de explicación que estas notas tienen sobre la prueba de conjunto y se constatará si dicha prueba es efectiva o redundante.

  2. EXAFS cumulants of CdSe

    International Nuclear Information System (INIS)

    Diop, D.

    1997-04-01

    EXAFS functions had been extracted from measurements on the K edge of Se at different temperatures between 20 and 300 K. The analysis of the EXAFS of the filtered first two shells has been done in the wavevector range laying between 2 and 15.5 A -1 in terms of the cumulants of the effective distribution of distances. The cumulants C 3 and C 4 obtained from the phase difference and the amplitude ratio methods have shown the anharmonicity in the vibrations of atoms around their equilibrium position. (author). 13 refs, 3 figs

  3. Thermoelectric power in n-InSe

    International Nuclear Information System (INIS)

    Casanovas, A.; Cantarero, A.; Segura, A.

    1985-01-01

    Thermoelectric power of InSe samples doped with tin has been measured as functions of the doping concentration in the range of 0.01 to 10% Sn and of the temperature in the range of 50 to 550 K. In the low temperature range the results obtained are coherent with the two-dimensional behaviour of electrons proposed by other authors. About 100 K the results can be explained successfully by introducing the same scattering mechanisms used to interpret the temperature dependence of the electron mobility

  4. Colloidal CdSe Quantum Rings.

    Science.gov (United States)

    Fedin, Igor; Talapin, Dmitri V

    2016-08-10

    Semiconductor quantum rings are of great fundamental interest because their non-trivial topology creates novel physical properties. At the same time, toroidal topology is difficult to achieve for colloidal nanocrystals and epitaxially grown semiconductor nanostructures. In this work, we introduce the synthesis of luminescent colloidal CdSe nanorings and nanostructures with double and triple toroidal topology. The nanorings form during controlled etching and rearrangement of two-dimensional nanoplatelets. We discuss a possible mechanism of the transformation of nanoplatelets into nanorings and potential utility of colloidal nanorings for magneto-optical (e.g., Aharonov-Bohm effect) and other applications.

  5. Mesoscopic NbSe3 wires

    International Nuclear Information System (INIS)

    Zant, H.S.J. van der; Kalwij, A.; Mantel, O.C.; Markovic, N.

    1999-01-01

    We have fabricated wire structures with (sub)micron sizes in the charge-density wave conductor NbSe 3 . Electrical transport measurements include complete mode-locking on Shapiro steps and show that the patterning has not affected the CDW material. Our mesoscopic wires show strong fluctuation and hysteresis effects in the low-temperature current-voltage characteristics, as well as a strong reduction of the phase-slip voltage. This reduction can not be explained with existing models. We suggest that single phase-slip events are responsible for a substantial reduction of the CDW strain in micron-sized systems. (orig.)

  6. Microstructure and thermoelectric properties of CuInSe2/In2Se3 compound

    Science.gov (United States)

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

    2018-01-01

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

  7. Stretched Exponential relaxation in pure Se glass

    Science.gov (United States)

    Dash, S.; Ravindren, S.; Boolchand, P.

    A universal feature of glasses is the stretched exponential relaxation, f (t) = exp[ - t / τ ] β . The model of diffusion of excitations to randomly distributed traps in a glass by Phillips1 yields the stretched exponent β = d[d +2] where d, the effective dimensionality. We have measured the enthalpy of relaxation ΔHnr (tw) at Tg of Se glass in modulated DSC experiments as glasses age at 300K and find β = 0.43(2) for tw in the 0 Se100-x glasses as x increases to 20%, the length of the polymeric Sen chains between the Ge-crosslinks decreases to n = 2. and the striking relaxation effects nearly vanish. J.C. Phillips, Rep.Prog.Phys. 59 , 1133 (1996). Supported by NSF Grant DMR 08-53957.

  8. Escuela para señoritas, Inglaterra

    Directory of Open Access Journals (Sweden)

    Stillman y Eastwlck-Field, Arquitectos

    1963-02-01

    Full Text Available The object was to design part of a new building which had been seriously damaged during the war, so that the old and new parts would blend into a pleasant whole, with a capacity for 600 girls. The new designs avoid the glass box style of school buildings, and glass walls have been adopted only on the ground floor, thus giving an impression of light and airiness to what used to be a partial basement. Classrooms have been designed in a simple manner, and give the impression of conventional rooms. Simple lines and materials have been chosen throughout. Strong contrasts in the external finish have been avoided, and colours provide a relaxing background to the intensive activities of the students. A constructional feature is the use of prefabricated concrete joists and supports. Outer walls consist of brick panels filling in the space between the visible concrete framework. Ceilings are of insulating boards, and the floors are covered with linoleum. Special attention has been devoted to the hall. In this case the roof is of white gypsum, and the only features are the grills covering the fluorescent lighting. The walls of this hall are of glass, and are covered with heavy velvet curtains. A balcony with hardwood posts adds a simple and friendly feature to the building. The furniture and drapery have been carefully chosen. Camden school has a rigid tradition of individualism and fine education, and the new building has succeeded in maintaining the exclusive quality of the older parts, as well as offering an overall impression of up to date construction.El problema consistía en proyectar un nuevo núcleo para un edificio que había sido seriamente bombardeado durante la guerra, de tal modo que las partes antiguas y nuevas formasen un conjunto agradable y con capacidad para más de 600 chicas. En la nueva construcción se ha evitado el carácter de «cajas de cristal» de las nuevas escuelas ordinarias y se han empleado muros de cristal solamente en la

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Montestruque, L.A.

    1978-01-01

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

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

    International Nuclear Information System (INIS)

    Mihajlov, Andjelka

    2010-01-01

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

  12. ZnSe MSM photodetectors prepared on GaAs and ZnSe substrates

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

  14. Reflexiones sobre el Real Decreto español 171/2007, de 9 de febrero, por el que se regula la publicidad de los protocolos familiares en las sociedades familiares

    Directory of Open Access Journals (Sweden)

    María Angustias Díaz Gómez

    2011-06-01

    Full Text Available El objeto de este trabajo es analizar el Protocolo Familiar, estudiando su concepto, naturaleza jurídica y eficacia, su contenido, publicidad y desarrollo. El protocolo familiar es un instrumento jurídico que pretende organizar la relación entre la familia y la empresa, separando ambas realidades y, especialmente, trata de planificar adecuadamente la sucesión de la empresa familiar. Se trata de reflexionar sobre el Real Decreto español 171/2007, de 9 de febrero, por el que se regula la publicidad de los protocolos familiares en las Sociedades Familiares.The object of this work is to analyze the Family Protocol, studying his concept, juridical nature and effectiveness, his content, advertising and development. The family protocol is a legal instrument that, intends to organize the interaction between a family and their family-owned business, separating both realities and, specially, it tries to plan adequately the succession of the family business. It is a question of thinking about the Spanish Royal decree 171/2007, of February 9rd, by which there is regulated the advertising of the family protocols in the Familiar Companies.

  15. No se olviden de Bernardo (Kordon

    Directory of Open Access Journals (Sweden)

    Eduardo Romano

    2006-09-01

    Full Text Available No casualmente el título coincide con un eslogan muy divulgado y que intenta conservar la memoria acerca de un hecho y de una víctima. No lo son también aquellos escritores a los que una mezquina política de mercado condena poco menos que al olvido, luego de que durante décadas animaran el proceso literario nacional y obtuvieran reconocimientos de diverso carácter por su producción? No me cabe duda de que Bernardo Kordon (1915-2002 fue uno de esos animadores de la narrativa nacional, al que es indispensable volver para que se entiendan mejor algunos cambios sucedidos en ella a partir de los años 50, aunque su culminación date de la década del 60 y un poco más.

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

    OpenAIRE

    Pablo Lorente Muñoz

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  18. Se-Se isoelectronic centers in high purity CdTe

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-15

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

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

    International Nuclear Information System (INIS)

    Margapoti, Emanuela

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Margapoti, Emanuela

    2010-07-01

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

  2. In situ observation of the formation of FeSe

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Wulff, Anders Christian; Yue, Zhao

    2011-01-01

    The formation of the FeSe compound from a mixture of Fe and Se powders encased in a composite Cu/Nb sheath was studied in situ by means of high-energy synchrotron x-ray diffraction. Tetragonal beta-FeSe does not seem to form directly from the starting elements. Instead, a sequence of FeSe2, Fe3Se...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-01

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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  5. A JUVENTUDE E OS COLETIVOS: COMO SE ARTICULAM NOVAS FORMAS DE EXPRESSÃO POLÍTICA

    Directory of Open Access Journals (Sweden)

    Gretha Leite Maia

    2013-07-01

    Full Text Available O artigo tem por objetivo investigar como se organiza a juventude contemporânea, em torno das redes sociais e no contexto dos novos movimentos sociais. A partir da revisão de literatura sobre juventude e movimentos sociais, analisa a inserção de novos paradigmas, como a liderança horizontal e a cooperação. Identifica formas atuais de mobilização, registro e monitoramento de ações repressivas, caracterizadas pela utilização ampla de suporte tecnológico. Como referência empírica, foram analisadas três experiências: o “Coletivo Conteste”, articulação do movimento estudantil em Fortaleza, junto aos estudantes de Direito da Universidade Federal do Ceará; o movimento estudantil “Barricadas abrem caminhos”; e a ação dos “capacetes”, grupo de registro das ações repressivas da polícia chilena durante manifestações estudantis. A hipótese a ser verificada é se, por meio desses novos paradigmas e experiências, pode-se afirmar a existência de um cenário consistente para o legítimo exercício da soberania popular. Trata-se assim de pesquisa bibliográfica com análise qualitativa de dados obtidos por meio de entrevista semiestruturada com um integrante do “Coletivo Conteste” e análise de sites. Conclui-se que a maneira como se articulam os jovens em torno dos coletivos, a pluralidade de interesses, os meios de mobilização para manifestações de massa e a forma de liderança horizontal são as mudanças mais significativas no atual contexto político brasileiro, viabilizadas pela disponibilidade de tecnologias de informação e comunicação, sem que, no entanto, haja uma reflexão conclusiva dessas mudanças. 

  6. Uma vida que se esvai no Parkinson

    Directory of Open Access Journals (Sweden)

    Eliane Michelini Marraccini

    Full Text Available A doença de Parkinson é uma síndrome neurológica de evolução lenta e progressiva que emerge na idade madura e velhice. A crescente debilitação física contrasta com a manutenção da integridade mental, na maioria dos pacientes até o fim da vida. Nessa enfermidade incurável, que costuma perdurar por longos anos, surgem importantes reações físicas diante da progressiva incapacitação, com profundos reflexos na subjetividade do paciente. Este trabalho refere-se ao atendimento de uma paciente, acompanhada em seu processo de conscientização e elaboração da irreversibilidade da doença. Ao final,é ressaltada a intrínseca articulação somatopsíquica, com destaque para a depressão na acentuação dos sintomas parkinsonianos.

  7. Determination of total, and bound Se in sera by INAA

    International Nuclear Information System (INIS)

    Spate, V.L.; Mason, M.M.; Reams, C.L.; Baskett, C.K.; Morris, J.S.; Mills, D.S.

    1994-01-01

    The comparison between the total selenium in serum ('total Se') with that which is apparently bound to high molecular weight (> 12.000 D) species, presumably proteins ('bound Se') was reported. Nine hundred seventy seven (977) serum samples arising out of a population-based epidemiological study were prepared in duplicate for the determination of 'total Se' by pipeting directly into irradiation vials; and separate duplicate aliquots were dialyzed against DI water for the determination of 'bound Se'. All samples were analyzed by neutron activation analysis via 77m Se (17.4s) A small dialyzable Se component (∼ 6%) ('free Se'), defined as the difference between the 'total Se' minus the 'bound Se', was identified. (author) 2 refs.; 3 figs.; 5 tabs

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  10. Increasing power and taking a lead - What are practitioners really doing? Empirical evidence from European communications managers/Incrementar el poder y asumir el liderazgo - ¿Qué hacen realmente los profesionales? Evidencias empíricas sobre los gestores de comunicación en Europa

    Directory of Open Access Journals (Sweden)

    Ángeles Moreno

    2014-05-01

    Full Text Available The aims of the paper and presented research are to monitor trends in communication management and to evaluate specific topics that include decision-making style, leadership style, role enactment and the power of communication departments in Europe. This paper is based on data from the European Communication Monitor (ECM annual research, the most comprehensive analysis of communication management worldwide. The ECM is an annual research project conducted since 2007. The ECM 2011 collected quantitative data through an on-line survey from 2,209 participating professionals from 43 European countries, with representation of every European region. This paper presents original connections about previous theory and offers empirical evidences about vertical and horizontal power of communication departments into organizations. On despite of the limitations of a self-reported survey, these evidences open new directions or research on hierarchical and social dimensions of power. The aim of this paper is to deepen the understanding of the power of communication management in organizations. Concretely, the paper aims to develop knowledge and understanding about horizontal and vertical power and the relationships established between these dimensions of power and strategic roles, decision making and leadership styles that communicators play. The paper presents original ideas by critiquing and re-focussing the literature and theory of power and leadership in organizations. The paper also presents new empirical data to support these arguments. // Las meta de este artículo y de la investigación que en él se presenta es hacer un seguimiento de las tendencias en gestión de comunicación mediante la evaluación de los estilos toma de decisiones, el estilo de liderazgo, los roles representados y el poder de los departamentos de comunicación en Europa. Este artículo se basa en datos del European Communication Monitor (ECM, el análisis más amplio de la gesti

  11. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-10-01

    Full Text Available Terrestrial inputs of freshwater flux to Sermilik Fjord, SE Greenland, were estimated, indicating ice discharge to be the dominant source of freshwater. A freshwater flux of 40.4 ± 4.9×109 m3 y−1 was found (1999–2008, with an 85% contribution originated from ice discharge (65% alone from Helheim Glacier, 11% from terrestrial surface runoff (from melt water and rain, 3% from precipitation at the fjord surface area, and 1% from subglacial geothermal and frictional melting due to basal ice motion. The results demonstrate the dominance of ice discharge as a primary mechanism for delivering freshwater to Sermilik Fjord. Time series of ice discharge for Helheim Glacier, Midgård Glacier, and Fenris Glacier were calculated from satellite-derived average surface velocity, glacier width, and estimated ice thickness, and fluctuations in terrestrial surface freshwater runoff were simulated based on observed meteorological data. These simulations were compared and bias corrected against independent glacier catchment runoff observations. Modeled runoff to Sermilik Fjord was variable, ranging from 2.9 ± 0.4×109 m3 y−1 in 1999 to 5.9 ± 0.9×109 m3 y−1 in 2005. The sub-catchment runoff of the Helheim Glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage, indicating high runoff volumes, where glacier cover was present at low elevations.

  12. Chemical synthesis of Cu2Se nanoparticles at room temperature

    International Nuclear Information System (INIS)

    Rong, Fengxia; Bai, Yan; Chen, Tianfeng; Zheng, Wenjie

    2012-01-01

    Graphical abstract: The Cu 2 Se nanoparticles were synthesized by a simple and rapid method at room temperature. The TEM and SEM images show that the Cu 2 Se nanoparticles were spherical. Highlights: ► Cu 2 Se nanoparticles were synthesized by the reaction of nanoSe 0 sol with Cu + ions. ► The Cu 2 Se nanoparticles were spherical with cubic structure and well crystallized. ► Optical and electrochemical properties of Cu 2 Se nanoparticles were observed. ► The formation mechanism of Cu 2 Se nanoparticles was proposed. -- Abstract: A simple and rapid method has been developed to synthesize cuprous selenide (Cu 2 Se) nanoparticles by the reaction of selenium nanoparticles sol with copper sulfate solution containing ascorbic acid at room temperature. Cu 2 Se nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray analysis (EDX). The results indicated that Cu 2 Se nanoparticles were cubic crystal structure and spherical with the diameter about 75 nm. The ultraviolet–visible absorption spectrum (UV–vis) and cyclic voltammetry of Cu 2 Se nanoparticles were also investigated. The optical band gap energy of Cu 2 Se nanoparticles was 1.94 eV. On the basis of a series of experiments and characterizations, the formation mechanism of Cu 2 Se nanoparticles was discussed.

  13. La desaceleración económica colombiana: se cosecha lo que se siembra

    Directory of Open Access Journals (Sweden)

    Carlos Humberto Ortiz

    2009-12-01

    Full Text Available La desaceleración económica que experimenta Colombia desde 1980 se explica por el estancamiento estructural de la economía y por la escalada de violencia relacionada con la expansión del narcotráfico. Los datos disponibles no rechazan esta hipótesis. El artículo plantea que la desindustrialización y el narcotráfico se forjaron en el mismo crisol: un modelo de desarrollo que ha integrado progresivamente la economía nacional a los mercados mundiales al tiempo que ha renunciado, también progresivamente, a la opción industrialista. Además, argumenta que la explosión del narcotráfico obedece a la profundización de la guerra contra las drogas en un contexto de demanda mundial creciente e inelástica.

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

    Science.gov (United States)

    Fassbender, Michael Ernst; Ballard, Beau D

    2013-09-10

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

  15. Optical band gap study of a-Se and Se-Sb thin films

    International Nuclear Information System (INIS)

    Kaur, Ramandeep; Singh, Palwinder; Thakur, Anup

    2016-01-01

    Amorphous selenium (a-Se) and a-Se_9_5Sb_5 alloy were prepared using melt quenching technique. X-ray diffraction (XRD) pattern confirmed the amorphous nature of the prepared samples. Composition of the prepared samples has been determined using Energy dispersive X-ray fluorescence (EDXRF) technique. Differential thermal analysis (DTA) confirmed the glassy nature of the prepared samples. Thin films of the prepared samples were deposited on glass substrate using thermal evaporation method. Amorphous nature of the deposited films was confirmed using XRD. Optical properties of these films were obtained from the UV-VIS transmission spectra, at normal incidence, over 200-1100 nm spectral range. The optical absorption edge was described by using the model given by the Tauc. Optical band gap of the deposited films was calculated using Tauc plot. Optical characterization showed that average transmission and optical band gap decreased with the addition of antinomy.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  17. Effect of nonstoichiometry properties of CuInSe2

    International Nuclear Information System (INIS)

    Rogacheva, E.I.; Tavrina, T.V.

    1997-01-01

    The homogeneity area size of the CuInSe 2 semiconductor compound is determined by the (CuIn)-Se profile of the Cu-In-Se ternary system at 350 deg C. The microhardness and thermo-electromotive force dependences on Se content are studied after various kind of thermal treatment. Interpretation of the results obtained is given with and account of defects formation character by deviations from stoichiometry [ru

  18. Electrodeposition of epitaxial CdSe on (111) gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Cachet, H.; Cortes, R.; Froment, M. [Universite Pierre et Marie Curie, Paris (France). Phys. des Liquides et Electrochimie; Etcheberry, A. [Institut Lavoisier (IREM) UMR CNRS C0173, Universite de Versailles- St Quentin en Yvelynes, 45 Avenue des Etats Unis, 78035, Versailles (France)

    2000-02-21

    Epitaxial growth of CdSe has been achieved on GaAs(111) by electrodeposition from an aqueous electrolyte. The structure of the film corresponds to the cubic modification of CdSe. The quality of epitaxy has been investigated by reflection high energy electron diffraction, transmission electron microscopy and X-ray diffraction techniques. By XPS measurements the chemistry of the CdSe/GaAs interface and the composition of CdSe are determined. (orig.)

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

    International Nuclear Information System (INIS)

    Tit, Nacir; Obaidat, Ihab M

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Albert J. Coetsee

    2015-03-01

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

  1. Electronic structure and magnetic properties of KCrSe2

    NARCIS (Netherlands)

    Fang, C.M.; Tolsma, P.R.; Groot, R.A. de; Wiegers, G.A.; Haas, C.; vanBruggen, C.F.; deGroot, R.A.

    1996-01-01

    KCrSe2 characterized by x-ray powder diffraction is a layered compound isostructural with NaCrSe2: a = 3.80 Angstrom; c = 22.19 Angstrom; space group R (3) over bar m. The magnetic properties are similar to those of NaCrSe2 but with ari even more pronounced difference between the intralayer and

  2. Luminescence of nanocrystalline ZnSe:Mn2+

    NARCIS (Netherlands)

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

    2000-01-01

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

  3. Exotic topological insulator states and topological phase transitions in Sb2Se3-Bi2Se3 heterostructures

    KAUST Repository

    Zhang, Qianfan; Zhang, Zhiyong; Zhu, Zhiyong; Schwingenschlö gl, Udo; Cui, Yi

    2012-01-01

    in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb 2Se 3-Bi 2Se 3 heterostructures by first-principle simulation and discovered

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

    Czech Academy of Sciences Publication Activity Database

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

    2006-01-01

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

  5. PbSe Quantum Well VECSEL on Si

    Science.gov (United States)

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

    2011-12-01

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

  6. Lateral structure of (TiSe2)n(NbSe2)m superlattices

    International Nuclear Information System (INIS)

    Noh, M.; Shin, H.; Jeong, K.; Spear, J.; Johnson, D.C.; Kevan, S.D.; Warwick, T.

    1997-01-01

    The structures of a series of (TiSe 2 ) n (NbSe 2 ) m superlattices grown through controlled crystallization of designed multilayer reactants have been studied. X-ray diffraction of the data of the superlattices after crystallization show considerable preferred orientation, with the basal plane of the dichalcogenide structure parallel to the substrate to within 0.1 degree. Lattice refinement using the observed (00scr(l)) diffraction maxima yields lattice parameters along the c axis that are consistent with those expected based on the target superlattices and lattice parameters of the binary constituents. These (00scr(l)) diffraction data, however, contain no information about the crystalline structure in the ab plane of the superlattice associated with the preferred c-axis orientation. Off-specular x-ray diffraction (XRD), scanning electron microscopy, and scanning transmission x-ray microscopy (STXM) were used to explore the structure and homogeneity of the superlattices in the ab plane. XRD results rule out preferred long-range orientational order of the ab plane. Between grains, both the backscattered electron images and STXM images show grain domain structure in the ab plane with a characteristic grain domain size of approximately 50 μm. X-ray absorption microscopy in the STXM mode obtained at the Ti L 2,3 edge shows that the titanium in the superlattices is present as both octahedral Ti consistent with the TiSe 2 structure and metallic Ti. A comparison of the data obtained from these techniques highlights chemical information, which can be deduced on a submicrometer range from the space resolved spectra obtained using STXM. copyright 1997 American Institute of Physics

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  8. È realmente esistita una polemica tra Arcesilao e la scuola epicurea? A-t-il vraiment existé une polémique entre Arcésilas et l'école épicurienne ? Did really exist any controversy between Arcesilaus and the Epicurean school?

    Directory of Open Access Journals (Sweden)

    Aurora Corti

    2013-05-01

    Full Text Available The purpose of this work is to attempt a reconstruction of the debate that existed between the Epicurean school and the Sceptic Academy in the 3rd century BC. At issue is a consideration of a section of Plutarch’s Against Colotes (1121E-1122F, which is a particularly important witness in favor of the actual existence of such a debate. The paper focuses not so much on the questions relevant such a debate – which are touched on here, but which themselves have an ample bibliography – but rather on the properly historiographical aspects, such as the identification of the beginner of the polemic or the reasons that brought it about. In reply to these inquiries it is possible to show that the originality of Colotes’ thought deserves much more serious consideration, also because Colotes played an important role within Epicureanism precisely as the originator of anti-Sceptic polemic.L’objet de cette étude est de chercher à reconstruire le débat entre l’école épicurienne et l’Académie sceptique au IIIe siècle avant J.-C. On examinera une section de l’Adversus Colotem de Plutarque (1121E-1122F, qui se présente comme un témoignage particulièrement significatif en faveur de l’existence effective d’un tel débat. On se concentrera non pas tant sur les questions qui sont en jeu – questions auxquelles on fera quelques allusions, mais sur lesquelles il existe déjà une vaste littérature –, que sur des aspects proprement historiographiques : de l’identification du promoteur de cette polémique aux raisons qui l’ont fait naître. En répondant à ces questions, on sera en mesure de montrer que l’originalité de la pensée de Colotès mérite d’être mieux mise en valeur, car Colotès a joué un rôle particulier au sein de l’épicurisme comme initiateur de la polémique anti-sceptique.Lo scopo del presente lavoro è cercare di ricostruire il dibattito intercorso tra la scuola epicurea e l’Accademia scettica nel

  9. Direct solution-phase synthesis of Se submicrotubes using Se powder as selenium source

    International Nuclear Information System (INIS)

    Yan Shancheng; Wang Haitao; Zhang Yuping; Li Shuchun; Xiao Zhongdang

    2009-01-01

    The selenium submicrotubes were directly prepared using Se powder as selenium source by microwave-assisted method. Field-emission scan electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were adopted to characterize the as-prepared products. The results of high-resolution transmission electron microscopy (HRTEM) and XRD pattern proved that the selenium submicrotubes were single crystalline in nature and [0 0 1] oriented. A possible growth mechanism of the selenium submicrotubes was proposed. The effects of the experimental conditions, such as alkaline concentration and solvent properties, on the morphology and dimension of the products have also been discussed

  10. Mapeamento do potencial de erosão laminar na bacia do rio Japaratuba, SE, via SIG Mapping the laminar erosion potential for the Japaratuba river basin, SE via GIS

    Directory of Open Access Journals (Sweden)

    Ricardo de Aragão

    2011-07-01

    Full Text Available A erosão do solo é a principal causa do empobrecimento precoce de terras produtivas e dentre as suas formas está a erosão laminar. Esta se caracteriza não apenas pela remoção de uma camada relativamente uniforme da superfície, mas também por seus nutrientes, sendo intensificada, portanto, pelas ações antrópicas. Para evitar ou reduzir seus impactos, fazem-se necessárias diretrizes para a adequação do uso e da ocupação às condições de cobertura vegetal, tipo de solo e topografia, através de mapas do potencial erosivo laminar da região de interesse, obtidos via sistemas de informações geográficas (SIG. Neste trabalho foi desenvolvido o mapeamento do potencial erosivo laminar da bacia do rio Japaratuba, SE (1685 km²; trata-se de uma região sujeita a intensa atividade agrícola, pecuária e de mineração, onde só restam 6% da vegetação nativa. Os resultados mostram que 48,71% da área da bacia ficam nas classes de médio e alto potencial erosivo, indicando que a bacia está bastante impactada devido aos usos inadequados para as condições de solo e declividades.Soil erosion is a natural phenomenon that reduces soil fertility and causes a great impact on agricultural areas. Laminar erosion is characterized by the removal of the top soil fairly uniformly as well as its nutrients, which is accelerated by human activities. To minimize the impacts it is necessary to adopt an adequate soil management that takes into account the type of the soil, relief, and vegetation cover. The soil management can be aided by mapping the erosive potential of a region using GIS tools. In this work, the technique that was used for mapping the erosive potential in the Japaratuba River Basin (1685 km² located in the State of Sergipe is presented. The results show that 48.71% of the basin area lie within medium and high erosive potentials zones, suggesting the inadequate land use for the soil types and relief within the basin.

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

    International Nuclear Information System (INIS)

    Serezhkina, L.B.

    1994-01-01

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

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

    Science.gov (United States)

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

    2012-10-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  14. «Un esclavo que se llama Antonio»: venta de dos esclavos asiáticos en Galicia a inicios del siglo XVII

    Directory of Open Access Journals (Sweden)

    Ménard, Caroline

    2012-12-01

    Full Text Available Slavery has existed in the Iberian Peninsula since the Antiquity and up to the Modern Era - and moreover, it was not restricted to the submission of people coming from Africa. This paper will look at the sale of two slaves originally from Asia, Antonio and Domingo, in 1603 in the port of Vigo - it will explore their journey, the role of the Carreira da India Portuguese mariners as sailors, their origin and sale price. Antonio and Domingo might represent a minority compared to all the slaves living at that time in Galicia, but their difference is a rich illustration of the process as it was then working.

    La esclavitud era conocida en la Península Ibérica desde la Antigüedad y durante la Época Moderna y no se limitó a la sumisión de personas de origen africana. Este artículo trata de la venta de dos esclavos de origen asiático, Antonio y Domingo, en el puerto de Vigo en 1603; en él se analiza la ruta emprendida por éstos, el papel desempeñado por los marineros portugueses de la Carreira da India como vendedores, así como su origen y precio. Antonio y Domingo representan una minoria dentro del conjunto de los esclavos viviendo en ese momento en Galicia, pero su presencia es un ejemplo ilustrativo de la dinámica vigente en la época. [gl] A escravitude era coñecida na Península Ibérica dende a Antigüidade e durante a Época Moderna e non se limitou a sumisión de persoas de orixe africana. Este artigo trata da venda de dous escravos de orixe asiática, Antonio e Domingo, no porto de Vigo no 1603. No artigo analízase a ruta realizada por estes e a súa orixe e prezo, así como o papel xogado polos mariñeiros portugueses na Carreira da India como vendedores. Antonio y Domingo representan unha corrente minoritaria dentro do conxunto dos escravos que viven en Galicia nesta época, mais a sua presencia é un bon exemplo da dinamica vivida nesta época.

  15. Synthesis of CdSe Quantum Dots Using Fusarium oxysporum

    Directory of Open Access Journals (Sweden)

    Takaaki Yamaguchi

    2016-10-01

    Full Text Available CdSe quantum dots are often used in industry as fluorescent materials. In this study, CdSe quantum dots were synthesized using Fusarium oxysporum. The cadmium and selenium concentration, pH, and temperature for the culture of F. oxysporum (Fusarium oxysporum were optimized for the synthesis, and the CdSe quantum dots obtained from the mycelial cells of F. oxysporum were observed by transmission electron microscopy. Ultra-thin sections of F. oxysporum showed that the CdSe quantum dots were precipitated in the intracellular space, indicating that cadmium and selenium ions were incorporated into the cell and that the quantum dots were synthesized with intracellular metabolites. To reveal differences in F. oxysporum metabolism, cell extracts of F. oxysporum, before and after CdSe synthesis, were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. The results suggested that the amount of superoxide dismutase (SOD decreased after CdSe synthesis. Fluorescence microscopy revealed that cytoplasmic superoxide increased significantly after CdSe synthesis. The accumulation of superoxide may increase the expression of various metabolites that play a role in reducing Se4+ to Se2− and inhibit the aggregation of CdSe to make nanoparticles.

  16. Synthesis of dextran/Se nanocomposites for nanomedicine application

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  17. Radioisotope Scanning of the Pancreas with Selenomethionine-Se{sup 75}; Gammagraphie du Pancreas a l'Aide de la Selenomethionine-{sup 75}Se; Diagnosticheskoe fotoskennirovanie podzheludochnoj zhelezy; Gammagrafia del Pancreas Mediante Radioisotopos

    Energy Technology Data Exchange (ETDEWEB)

    Sodee, D. B. [Doctors Hospital and Renner Clinic Foundation, Cleveland Heights, OH (United States)

    1964-10-15

    casos. El carcinoma mas pequeno que no pudo visualizarse estaba ocultado por el higado hipertrofiado. La exploracion pancreatica permite tambien confirmar la pancreatitis aguda y cronica, ya que las celulas lesionadas no concentran la selenometionina-{sup 75}Se. El autor trata ademas de la concentracion selectiva de la selenometionina{sup 75}Se en el tejido paratiroideo. Con la misma tecnica de expioracion se han visualizado adenomas paratiroideos en un pequeno grupo de enfermos de hiperparatiroidismo. La fotoexploracion del pancreas es ya una tecnica de uso corriente; actualmente se estudia la posibilidad de una fotoexploracion de la paratiroides. Debido a la mayor importancia medica atribuida a organos que antes no podian visualizarse con las tecnicas radiograficas tradicionales, la exploracion selectiva de organos por medio de compuestos marcados, elegidos segun sus propiedades bioquimicas, va adquiriendo cada vez mayor importancia. (author) [Russian] Nedavno bylo pokazano, chto fotoskennirovanie podzheludochnoj zhelezy s pomoshh'ju selenometionina, mechennogo {sup 75}Se , javljaetsja prakticheskim metodom. U 90%iz 100 bol'nyh, u kotoryh bylo polucheno 250 podobnyh fotoskennogramm, mozhno bylo otchetlivo videt' podzheludochnuju zhelezu. Bylo obnaruzheno, chto fiziologicheskaja stimuljacija podzheludochnoj zhelezy javljaetsja glavnym faktorom koncentracii selenometionina -Se15 v podzheludochnoj zheleze. Za chas do vnutrivennogo vvedenija v organizm 3-4 mkk/kg selenometionina-Ze75 s pomoshh'ju 30 grammov belkovoj pishhi byla nachata fiziologicheskaja stimuljacija podzheludochnoj zhelezy. Cherez 15 minut byla dostignuta nepreryvnaja stimuljacija podzheludochnoj zhelezy putem vvedenija cherez rot 900 mkg gidrohlorida glutaminovoj kisloty. Do skennirovanija podzheludochnoj zhelezy nad oblast'ju pecheni, predvaritel'no opredelennoj pri skennirovanii s pomoshh'ju zolota-198, byl pomeshhen izognutyj zashhitnyj jekran iz svinca razmerom 0,9 sm, Jetot jekran blokiruet

  18. Timely resolved measurements on CdSe nanoparticles; Zeitaufgeloeste Messungen an CdSe Nanopartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Holt, B.E. von

    2006-06-06

    By means of infrared spectroscopy the influence of the organic cover on structure and dynamics of CdSe nanoparticles was studied. First a procedure was developed, which allows to get from the static infrared spectrum informations on the quality of the organic cover and the binding behaviour of the ligands. On qualitatively high-grade and well characterized samples thereafter the dynamics of the lowest-energy electron level 1S{sub e} was time-resolvedly meausred in thew visible range. As reference served CdSe TOPO, which was supplemented by samples with the ligands octanthiole, octanic acid, octylamine, naphthoquinone, benzoquinone, and pyridine. The studied nanoparticles had a diameter of 4.86 nm. By means of the excitation-scanning or pump=probe procedure first measurements in the picosecond range were performed. The excitation wavelengths were thereby spectrally confined and so chosen that selectively the transitions 1S{sub 3/2}-1S-e and 1P{sub 3/2}-1P{sub e} but not the intermediately lyingt transition 2S{sub 3/2}-1S{sub e} were excited. The excitation energies were kept so low that the excitation of several excitons in one crystal could be avoided. The scanning wavelength in the infrared corresponded to the energy difference between the electron levels 1S{sub e} and 1P{sub e}. The transients in the picosecond range are marked by a steep increasement of the signal, on which a multi-exponential decay follows. The increasement, which reproduces the popiulation of the excited state, isa inependent on the choice of the ligands. The influence of the organic cover is first visible in the different decay times of the excited electron levels. the decay of the measurement signal of CdSe TOPO can be approximatively described by three time constants: a decay constant in the early picosecond region, a time constant around hundert picoseconds, and a time constant of some nanoseconds. At increasing scanning wavelength the decay constants become longer. By directed excitation

  19. Negative ion photoelectron spectroscopy of SeO-

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  20. PySE: Software for extracting sources from radio images

    Science.gov (United States)

    Carbone, D.; Garsden, H.; Spreeuw, H.; Swinbank, J. D.; van der Horst, A. J.; Rowlinson, A.; Broderick, J. W.; Rol, E.; Law, C.; Molenaar, G.; Wijers, R. A. M. J.

    2018-04-01

    PySE is a Python software package for finding and measuring sources in radio telescope images. The software was designed to detect sources in the LOFAR telescope images, but can be used with images from other radio telescopes as well. We introduce the LOFAR Telescope, the context within which PySE was developed, the design of PySE, and describe how it is used. Detailed experiments on the validation and testing of PySE are then presented, along with results of performance testing. We discuss some of the current issues with the algorithms implemented in PySE and their interaction with LOFAR images, concluding with the current status of PySE and its future development.

  1. Atomic Defects and Doping of Monolayer NbSe2.

    Science.gov (United States)

    Nguyen, Lan; Komsa, Hannu-Pekka; Khestanova, Ekaterina; Kashtiban, Reza J; Peters, Jonathan J P; Lawlor, Sean; Sanchez, Ana M; Sloan, Jeremy; Gorbachev, Roman V; Grigorieva, Irina V; Krasheninnikov, Arkady V; Haigh, Sarah J

    2017-03-28

    We have investigated the structure of atomic defects within monolayer NbSe 2 encapsulated in graphene by combining atomic resolution transmission electron microscope imaging, density functional theory (DFT) calculations, and strain mapping using geometric phase analysis. We demonstrate the presence of stable Nb and Se monovacancies in monolayer material and reveal that Se monovacancies are the most frequently observed defects, consistent with DFT calculations of their formation energy. We reveal that adventitious impurities of C, N, and O can substitute into the NbSe 2 lattice stabilizing Se divacancies. We further observe evidence of Pt substitution into both Se and Nb vacancy sites. This knowledge of the character and relative frequency of different atomic defects provides the potential to better understand and control the unusual electronic and magnetic properties of this exciting two-dimensional material.

  2. Ser portador de diabetes tipo 2: cuidando-se para continuar vivendo = To be carrying of diabetes type 2: taking care of itself to continue living

    Directory of Open Access Journals (Sweden)

    Welfer, Márcia

    2005-01-01

    Full Text Available Objetivo: Conhecer o que os pacientes diabéticos tipo 2 sabem sobre os cuidados que devem ter para manterem-se estáveis evitando complicações decorrentes dessa patologia. Métodos: Este trabalho trata de uma pesquisa de natureza qualitativa, exploratória e descritiva. A aquisição dos dados ocorreu entre março e abril de 2004, por meio de entrevista com onze portadores de diabetes, residentes no município de Ijuí/RS. Para a aná- lise das informações procedeu-se a ordenação, classificação dos dados e análise final. Resultados: Os dados foram agrupados em duas categorias de análise: a primeira aborda questões referentes ao conhecimento dos pacientes portadores de diabetes acerca do auto cuidado e a segunda categoria aborda sobre quem fornece as informações e orientações. Discussão: O estudo possibilitou identificar que os pacientes portadores de diabetes vivenciam modificações em seu cotidiano, para a manutenção da estabilidade da doença, especialmente em respeito à alimentação. Os profissionais de saúde tem importante função, realizando orientações, esclarecimentos e fornecendo suporte necessário para esses pacientes

  3. Symmetry and optical anisotropy in CdSe/ZnSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, Tobias

    2009-10-29

    The material system of choice for the investigations performed in the frame of this Thesis were self-assembled CdSe/ZnSe QDs. The reason for this choice is twofold. First, CdSe/ZnSe QDs can be grown with excellent optical quality, which is a prerequiste for optical studies. Second, due to the polar nature of II-VI compound semiconductors, optical anisotropies induced by various asymmetries are more pronounced than in their IIIV or element IV counterparts. Unlike in the III-V materials, where the self-organization of QDs is well described by the Stranski-Krastanow growth mode, the peculiarities of the QD formation are not entirely clear in II-VI alloys. For the purposes of the current work QDs emerging from two variants of Molecular Beam Epitaxy (MBE) growth were studied. In order to establish a clear connection between the optically observed anisotropies and the growth induced asymmetries in the QDs we start out by summarizing all available structural and morphological studies that were performed on the resultant QDs, including x-ray diffraction, atomic force microscopy, high resolution transmission electron microscopy and resonant Raman scattering. Extensive investigations by Photoluminescence (PL) and Photoluminescence Excitation (PLE) spectroscopy hence detail the resultant electronic structure of excitons confined to the above QDs as well as their energy relaxation across the latter. We find that for these small-sized strongly confining QDs k-vector conservation is entirely relaxed, which enables interaction of the excitons with a continuum of phonons and explains fast and efficient exciton capture by the QDs, even for excitation conditions far above the ground state. We demonstrate how this provides an alternative fast relaxation channel to Auger-like electron-hole scattering, that may also explain fast hole relaxation and adds to the understanding of the absence of a phonon bottleneck in the energy relaxation in these type of QDs. With the above analysis as a

  4. Symmetry and optical anisotropy in CdSe/ZnSe quantum dots

    International Nuclear Information System (INIS)

    Kiessling, Tobias

    2009-01-01

    The material system of choice for the investigations performed in the frame of this Thesis were self-assembled CdSe/ZnSe QDs. The reason for this choice is twofold. First, CdSe/ZnSe QDs can be grown with excellent optical quality, which is a prerequiste for optical studies. Second, due to the polar nature of II-VI compound semiconductors, optical anisotropies induced by various asymmetries are more pronounced than in their IIIV or element IV counterparts. Unlike in the III-V materials, where the self-organization of QDs is well described by the Stranski-Krastanow growth mode, the peculiarities of the QD formation are not entirely clear in II-VI alloys. For the purposes of the current work QDs emerging from two variants of Molecular Beam Epitaxy (MBE) growth were studied. In order to establish a clear connection between the optically observed anisotropies and the growth induced asymmetries in the QDs we start out by summarizing all available structural and morphological studies that were performed on the resultant QDs, including x-ray diffraction, atomic force microscopy, high resolution transmission electron microscopy and resonant Raman scattering. Extensive investigations by Photoluminescence (PL) and Photoluminescence Excitation (PLE) spectroscopy hence detail the resultant electronic structure of excitons confined to the above QDs as well as their energy relaxation across the latter. We find that for these small-sized strongly confining QDs k-vector conservation is entirely relaxed, which enables interaction of the excitons with a continuum of phonons and explains fast and efficient exciton capture by the QDs, even for excitation conditions far above the ground state. We demonstrate how this provides an alternative fast relaxation channel to Auger-like electron-hole scattering, that may also explain fast hole relaxation and adds to the understanding of the absence of a phonon bottleneck in the energy relaxation in these type of QDs. With the above analysis as a

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

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-05-01

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

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

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-03-01

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

  7. SeRLoc: Robust Localization for Wireless Sensor Networks

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2005-01-01

    .... We show that SeRLoc is robust against known attacks on WSNs such as the wormhole attack, the Sybil attack, and compromise of network entities and analytically compute the probability of success for each attack. We also compare the performance of SeRLoc with state-of-the-art range-independent localization schemes and show that SeRLoc has better performance.

  8. The synthesis and photocatalytic activity of ZnSe microspheres

    International Nuclear Information System (INIS)

    Cao Huaqiang; Xiao Yujiang; Zhang Sichun

    2011-01-01

    This paper reports the synthesis of semiconductor ZnSe microspheres composed of nanoparticles via a solvothermal route between the organic molecule selenophene (C 4 H 4 Se) and ZnCl 2 without adding any surfactant. The ZnSe microspheres were characterized by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), specific surface area measurement, and photoluminescence (PL) spectra. A strong and broad blue PL emission at 443 nm in wavelength (∼2.79 eV in photon energy) is attributed to the near-band-edge (NBE) emission of ZnSe, while the 530 nm peak is a defect-related (DL) emission. The photocatalytic activity of the as-prepared ZnSe microspheres was evaluated by photodegradation of methyl orange (MO) dye under ultraviolet (UV) light and visible light irradiation. The degradations of MO reach 94% or 95.1%, close to 100%, in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 7 or 10 h under UV irradiation, respectively. Meanwhile the degradations of MO reach 94.3% or 60.6% in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 12 h, respectively. The degradation rate of ZnSe microspheres is twice that of ZnSe commercial powder under UV light irradiation, and three times under visible light irradiation. The degradation process of MO dye on ZnSe microspheres under UV or visible light is also discussed.

  9. Atomic defects and doping of monolayer NbSe2

    OpenAIRE

    Nguyen, Lan; Komsa, Hannu-Pekka; Khestanova, Ekaterina; Kashtiban, Reza J; Peters, Jonathan J.P.; Lawlor, Sean; Sanchez, Ana M.; Sloan, Jeremy; Gorbachev, Roman; Grigorieva, Irina; Krasheninnikov, Arkady V.; Haigh, Sarah

    2017-01-01

    We have investigated the structure of atomic defects within monolayer NbSe2 encapsulated in graphene by combining atomic resolution transmission electron microscope imaging, density functional theory (DFT) calculations, and strain mapping using geometric phase analysis. We demonstrate the presence of stable Nb and Se monovacancies in monolayer material and reveal that Se monovacancies are the most frequently observed defects, consistent with DFT calculations of their formation energy. We reve...

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

    Science.gov (United States)

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

    2014-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-03

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

  12. Geoquímica de las aguas subterráneas en rocas metamórficas al SE de Salamanca

    Directory of Open Access Journals (Sweden)

    García, A.

    1991-08-01

    Full Text Available This paper describes the results of 77 chemical analyses of groundwater from springs and wells in the «Complejo Esquisto Grauváquico» and other paleozoic materials from the south of Salamanca province. The types of groundwater are very diverse, usually bicarbonate dominant, with TDS (Total Dissolved Solids between 0.6 and 16 milimoles/l. Salinity is shown to be greater in the drilled wells than in the dug wells and springs, which confirms the existence of deep flow. Principal Component Analysis indicates that the chemical composition of groundwater must be the result of multiple reactions between the water and the minerals that occur in parallel, with none of the reactions being specially predominant. The organization and geographic distribution of sorne of the elements suggest the existence of regional flow systems.Se presentan los resultados de 77 análisis químicos de aguas subterráneas procedentes de manantiales, pozos excavados y sondeos en el Complejo Esquisto Grauváquico y otros materiales paleozoicos al Sur de la provincia de Salamanca. Se trata de aguas muy dispares, en general bicarbonatadas mixtas, con TSD (total de sólidos disueltos entre 0,6 y 16 milimoles/l. Se pone de manifiesto una mayor salinidad de las aguas de sondeos en relación con las de pozos y manantiales, lo que demuestra la existencia de una circulación a cierta profundidad. El análisis de componentes principales muestra que la composición química de las aguas debe ser el resultado de múltiples reacciones entre el agua y los minerales que se producen en paralelo, sin que destaque ninguna en especial. La distribución geográfica ordenada de algunos elementos obliga a plantear como posible la hipótesis de la existencia de un flujo regional.

  13. Cultivation and characterization of GaInSe2 crystals

    International Nuclear Information System (INIS)

    Panakhov, T.M.; Kafarova, D.M.

    2013-01-01

    This work is the first systematic study devoted to the growth of GaInSe 2 crystals and their characterization by experimental methods such as X-ray diffraction, electron microscopy transmission with high resolution, sample electron diffraction. By the method of photoelectron roentgen spectroscopy it was studied the chemical structure of the GaInSe 2 crystals and the microprobe analysis indicated that the individual crystals have an excess of gallium. GaInSe 2 crystals were grown by the Bridgman method. Samples were prepared as single crystals by the Bridgman method. Studies showed that the GaInSe 2 crystals are hexagonal ones

  14. Epitaxial CdSe-Au nanocrystal heterostructures by thermal annealing.

    Science.gov (United States)

    Figuerola, Albert; van Huis, Marijn; Zanella, Marco; Genovese, Alessandro; Marras, Sergio; Falqui, Andrea; Zandbergen, Henny W; Cingolani, Roberto; Manna, Liberato

    2010-08-11

    The thermal evolution of a collection of heterogeneous CdSe-Au nanosystems (Au-decorated CdSe nanorods, networks, vertical assemblies) prepared by wet-chemical approaches was monitored in situ in the transmission electron microscope. In contrast to interfaces that are formed during kinetically controlled wet chemical synthesis, heating under vacuum conditions results in distinct and well-defined CdSe/Au interfaces, located at the CdSe polar surfaces. The high quality of these interfaces should make the heterostructures more suitable for use in nanoscale electronic devices.

  15. ¿Como se hace publicidad por internet?

    Directory of Open Access Journals (Sweden)

    Franz Del Pozo

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

    Eremenko, M; Budkin, G; Reznitsky, A

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  20. Antología de la poesía Eslovena Traducción y notas de María Francisca. de Castro Gil, Introducción de France Koren, Madrid, 1954

    Directory of Open Access Journals (Sweden)

    Irene Mislej

    1995-12-01

    Full Text Available Por intennedio de un distinguido cientifico es1oveno que reside en Canadá, el dr. Srečko Pregelj, ha llegado a mis manos un manuscrito sumamente interesante. Se trata de una Antología de la Poesía eslovena, la cual evidentemente había sido preparada para su impresión en 1954, en Madrid. El hecho de que contemos con tan pocas traducciones de obras literarias eslovenas al castellano hace de este descubrimiento algo realmente curioso e importante. La obra es fruto de la colaboración estrecha de un emigrante esloveno, France Koren y de una escritora y poetisa espanola, María Francisca de Castro Gil. El nacimiento de una obra tan singular merece algunas palabras de explicación.

  1. ¿Dios problemático?

    Directory of Open Access Journals (Sweden)

    García Baró, Miguel

    2002-04-01

    Full Text Available Not available

    El final de la modernidad, ya con dos siglos de historia, es, desde el punto de vista de la religión y su filosofía, sobre todo la gran cuestión abierta de cómo pueda continuar la empresa de la emancipación del hombre después del fracaso del idealismo absoluto y de sus secuelas. Se trata de un tiempo que ha sido comparado con justicia al de una «segunda inocencia», donde importa esencialmente afrontar en toda su amplitud y seriedad el problema del mal y la posibilidad de una esperanza realmente dirigida a la salvación de Dios, y no a cualquier objetivo intramundano.

  2. Electronic structure and superconductivity of FeSe-related superconductors.

    Science.gov (United States)

    Liu, Xu; Zhao, Lin; He, Shaolong; He, Junfeng; Liu, Defa; Mou, Daixiang; Shen, Bing; Hu, Yong; Huang, Jianwei; Zhou, X J

    2015-05-13

    FeSe superconductors and their related systems have attracted much attention in the study of iron-based superconductors owing to their simple crystal structure and peculiar electronic and physical properties. The bulk FeSe superconductor has a superconducting transition temperature (Tc) of ~8 K and it can be dramatically enhanced to 37 K at high pressure. On the other hand, its cousin system, FeTe, possesses a unique antiferromagnetic ground state but is non-superconducting. Substitution of Se with Te in the FeSe superconductor results in an enhancement of Tc up to 14.5 K and superconductivity can persist over a large composition range in the Fe(Se,Te) system. Intercalation of the FeSe superconductor leads to the discovery of the AxFe2-ySe2 (A = K, Cs and Tl) system that exhibits a Tc higher than 30 K and a unique electronic structure of the superconducting phase. A recent report of possible high temperature superconductivity in single-layer FeSe/SrTiO3 films with a Tc above 65 K has generated much excitement in the community. This pioneering work opens a door for interface superconductivity to explore for high Tc superconductors. The distinct electronic structure and superconducting gap, layer-dependent behavior and insulator-superconductor transition of the FeSe/SrTiO3 films provide critical information in understanding the superconductivity mechanism of iron-based superconductors. In this paper, we present a brief review of the investigation of the electronic structure and superconductivity of the FeSe superconductor and related systems, with a particular focus on the FeSe films.

  3. Transport Properties of ZnSe- ITO Hetero Junction

    Science.gov (United States)

    Ichibakase, Tsuyoshi

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

  4. 79Se: geochemical and crystallo-chemical retardation mechanisms

    International Nuclear Information System (INIS)

    Chen, F.; Ewing, R.C.

    1999-01-01

    79 Se is a long-lived (1.1 x 10 6 yrs) fission product which is chemically and radiologically toxic. Under Eh-pH conditions typical of oxidative alteration of spent nuclear fuel, selenite, SeO 3 2- or HSeO 3 - or selenate, SeO 4 2- , are the dominant aqueous species of selenium. Because of the high solubility of metal-selenites and metal-selenates and the low adsorption of selenite and selenate aqueous species by geological materials under alkaline conditions, selenium may be highly mobile. However, 79 Se released from altered fuel may become immobilized by incorporation into secondary uranyl phases as low concentration impurities, and this may significantly reduce the mobility of selenium. Analysis and comparison of the known structures of uranyl phases indicate that (SeO 3 ) may substitute for (SiO 3 OH) in structures of α-uranophane and boltwoodite that are expected to be the dominant alteration products of UO 2 in Si-rich groundwater. The substitutions (SeO 3 ) (SiO 3 OH) in sklodowskite, Mg[(UO 2 )(SiO 3 OH)] 2 (H 2 O) 6 and (SeO 3 ) (PO 4 ) in phurcalite, Ca 2 [(UO 2 ) 3 (PO 4 ) 2 O 2 ](H 2 O) 7 , may occur with the eliminated apical anion being substituted for by an H 2 O group, but experimental investigation is required. The close similarity between the sheets in the structures of rutherfordine, [(UO 2 )(CO 3 )] and [(UO 2 )(SeO 3 )] implies that the substitution (SeO 3 ) (CO 3 ) can occur in rutherfordine, and possibly other uranyl carbonates. However, the substitutions: (SeO 3 ) (SiO 4 ) in soddyite and (SeO 3 ) (PO 4 ) in phosphuranylite may disrupt their structural connectivity and are, therefore, unlikely. (orig.)

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2014-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Guozhi Jia

    2015-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Kudrynskyi Z. R.

    2012-12-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

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

    International Nuclear Information System (INIS)

    Tang Gao; Liu Cunming; Luo Lan; Chen Wei

    2010-01-01

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

  11. On the reversibility window in binary As-Se glasses

    International Nuclear Information System (INIS)

    Golovchak, R.; Shpotyuk, O.; Kozdras, A.

    2007-01-01

    Physical ageing effects caused by prolonged natural storage are recorded for binary As x Se 1-x glasses with 0.2≤x 2 Se 3 composition, which network is formed by a so-called self-organized phase, possesses the ideal non-ageing ability

  12. Photoelectrochemical (PEC) studies on CdSe thin films ...

    Indian Academy of Sciences (India)

    TECS

    Thin films of CdSe were deposited by potentiostatic mode on different substrates such as ... trodeposited from aqueous acidic baths, but very few ... washed with liquid detergent (labolene) followed by ul- .... increases the ionic mobilities and hence the conductivity ... A PEC cell of configuration, CdSe/1 M polysulphide/.

  13. Preparation of PbSe nanoparticles by electron beam irradiation

    Indian Academy of Sciences (India)

    A novel method has been developed by electron beam irradiation to prepare PbSe nanoparticles. 2 MeV 10mA GJ-2-II electronic accelerator was used as radiation source. Nanocrystalline PbSe was prepared rapidly at room temperature under atmospheric pressure without any kind of toxic reagents. The structure and ...

  14. Origin of low thermal conductivity in SnSe

    Science.gov (United States)

    Xiao, Yu; Chang, Cheng; Pei, Yanling; Wu, Di; Peng, Kunling; Zhou, Xiaoyuan; Gong, Shengkai; He, Jiaqing; Zhang, Yongsheng; Zeng, Zhi; Zhao, Li-Dong

    2016-09-01

    We provide direct evidence to understand the origin of low thermal conductivity of SnSe using elastic measurements. Compared to state-of-the-art lead chalcogenides Pb Q (Q =Te , Se, S), SnSe exhibits low values of sound velocity (˜1420 m /s ) , Young's modulus (E ˜27.7 GPa ) , and shear modulus (G ˜9.6 GPa ) , which are ascribed to the extremely weak Sn-Se atomic interactions (or bonds between layers); meanwhile, the deduced average Grüneisen parameter γ of SnSe is as large as ˜3.13, originating from the strong anharmonicity of the bonding arrangement. The calculated phonon mean free path (l ˜ 0.84 nm) at 300 K is comparable to the lattice parameters of SnSe, indicating little room is left for further reduction of the thermal conductivity through introducing nanoscale microstructures and microscale grain boundaries. The low elastic properties indicate that the weak chemical bonding stiffness of SnSe generally causes phonon modes softening which eventually slows down phonon propagation. This work provides insightful data to understand the low lattice thermal conductivity of SnSe.

  15. Low temperature magnetic structure of MnSe

    Indian Academy of Sciences (India)

    Abstract. In this paper we report low temperature neutron diffraction studies on MnSe in order to understand the anomalous behaviour of their magnetic and transport prop- erties. Our study indicates that at low temperatures MnSe has two coexisting crystal structures, high temperature NaCl and hexagonal NiAs. NiAs phase ...

  16. Thermoelectric Performance of Na-Doped GeSe

    NARCIS (Netherlands)

    Shaabani, Laaya; Aminorroaya-Yamini, Sima; Byrnes, Jacob; Akbar Nezhad, Ali; Blake, Graeme R

    2017-01-01

    Recently, hole-doped GeSe materials have been predicted to exhibit extraordinary thermoelectric performance owing largely to extremely low thermal conductivity. However, experimental research on the thermoelectric properties of GeSe has received less attention. Here, we have synthesized

  17. Wittgenstein og respekten for det religiøse

    DEFF Research Database (Denmark)

    Albinus, Lars

    2006-01-01

    Fremstilling af den tidlige og den sene Wittgensteins forhold til det religiøse med særligt henblik på tabet af umiddelbarhed.......Fremstilling af den tidlige og den sene Wittgensteins forhold til det religiøse med særligt henblik på tabet af umiddelbarhed....

  18. SE-ENRICHMENT OF CARROT AND ONION VIA FOLIAR APPLICATION

    OpenAIRE

    Kapolna, Emese; Laursen, Kristian H.; Hillestrøm, Peter; Husted, Søren; Larsen, Erik H.

    2008-01-01

    The aim of this work was to study the selenium accumulation in carrot and onion plants using foliar application by sodium selenite and sodium selenate. Furthermore, we aimed at identifying the Se species biosynthesised by onion and carrot plants. The results were used to prepare for production of 77Se enriched plants for an ongoing human absorption study.

  19. Structural characterization of vacuum evaporated ZnSe thin films

    Indian Academy of Sciences (India)

    The lattice parameter, grain size, average internal stress, microstrain, dislocation density and degree of pre- ferred orientation in the film are calculated and correlated with Ts. Keywords. ZnSe thin films; X-ray diffraction; average internal stress; microstrain; dislocation density. 1. Introduction. Thin films of ZnSe has attracted ...

  20. A Review of SnSe: Growth and Thermoelectric Properties

    Science.gov (United States)

    Nguyen, Van Quang; Kim, Jungdae; Cho, Sunglae

    2018-04-01

    SnSe is a 2D semiconductor with an indirect energy gap of 0.86 - 1 eV; it is widely used in solar cell, optoelectronics, and electronic device applications. Recently, SnSe has been considered as a robust candidate for energy conversion applications due to its high thermoelectric performance ( ZT = 2.6 in p-type and 2.2 in n-type), which is assigned mainly to its anhamornic bonding leading to an ultralow thermal conductivity. In this review, we first discuss the crystalline and electronic structures of SnSe and the source of its p-type characteristic. Then, some typical single crystal and polycrystal growth techniques, as well as an epitaxial thin film growth technique, are outlined. The reported thermoelectric properties of SnSe grown by using each technique are also reviewed. Finally, we will describe some remaining issues concerning the use of SnSe for thermoelectric applications.

  1. Structural and optical properties of CdSe nanosheets

    Science.gov (United States)

    Solanki, Rekha Garg; Rajaram, P.; Arora, Aman

    2018-04-01

    Nanosheets of CdSe have been synthesized using a solvothermal route using citric acid as an additive. It is found that the citric acid effectively controls the structural and optical properties of CdSe nanostructures. XRD studies confirm the formation of hexagonal wurtzite phase of CdSe. The FESEM micrographs show that the obtained CdSe nanocrystals are in the form of very thin sheets (nanosheets). Optical absorption studies as well as Photoluminescence spectra show that the optical gap is around 1.76 eV which is close to the reported bulk value of 1.74 eV. The prepared CdSe nanosheets because of large surface area may be useful for catalytic activities in medicine, biotechnology and environmental chemistry and in biomedical imaging for in vitro detection of a breast cancer cells.

  2. "CRISTO JESUS, O QUAL SE TORNOU SABEDORIA DE DEUS PARA NÓS, ISTO É, JUSTIÇA, SANTIDADE E REDENÇÃO" (l COR 1,30

    Directory of Open Access Journals (Sweden)

    Nélio Schneider

    2000-01-01

    Full Text Available Este breve artigo trata do assunto de maior envergadura na teologia do apóstolo Paulo. A cristologia é o elemento que tudo perpassa, a perspectiva que lança nova luz sobre todas as possíveis considerações teológicas e pastorais. Cristo crucificado e ressuscitado é o conteúdo próprio do evangelho, é a boa nova para toda a criação. Embora possa parecer uma loucura, ele é a expressão maior da sabedoria de Deus, que se manifesta como justiça, santidade e redenção, atribuídas às pessoas por iniciativa de Deus mesmo (1 Co 1,30. Essa definição que o próprio apóstolo dá de Cristo fornece a chave para a compreensão do tema.

  3. Immobilization of Se and U by iron sulfides

    International Nuclear Information System (INIS)

    Kang Mingliang; Ma Bin; Yang Zhuanwei; Liu Chunli; Chen Fanrong

    2014-01-01

    Both uranium and selenium are redox-sensitive, and can occur in several oxidation states. In reducing environments, they exist as insoluble forms. Therefore, reductive precipitation is the most effective way to immobilize U and Se. The interaction of aqueous Se (IV) and uranylwithiron sulfidesweresystematically investigated in light of thermodynamic calculations, X-ray Absorption Spectroscopy (XAS), and X-ray Photoelectron Spectroscopy (XPS). The results from the speciation study revealed that the reduction product was Se (O) when natural pyrite and pyrrhotitereacted with Se (IV), although FeSe 2 is the thermodynamically predicted product from nearly neural to alkaline conditions. This discrepancy is attributed to the oxidizing ability of Se (IV) towards FeSe 2 , of which produce the insoluble Se (0) as the stable product in short-term experiments. In contrast to the thermodynamic calculations, with a reaction product of mixed U (IV) and U (VI) (e.g., U 3 O 8 ), redox reaction was observed only at pH ∼ 8.5 and ∼ 4.5 for U (VI) reduction by nanosized pyrite and natural pyrite, respectively. We proposed that oxidation of pyrite needs an intermediate (e.g., Fe 2+ ), and the reaction between the uranyl and the intermediate is thermodynamically or kinetically limited. Moreover, trace elements generally held within pyrite structure can also greatly influence its reactivity. This study demonstrated that reaction kinetics play a significant role on the reaction product. From a geological time scale, Se and U are likely to be immobilized by iron sulfides via the form of FeSe 2 and UO 2 . (authors)

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-01

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

  7. Photoacoustic spectroscopy of thin films of As2S3, As2Se3 and GeSe2

    Indian Academy of Sciences (India)

    Photoacoustic spectroscopy (PAS) is one of the important branches of spectroscopy, which enables one to detect light-induced heat production following the absorption of pulsed radiation by the sample. As2S3, As2Se3 and GeSe2 exhibit a wide variety of photo-induced phenomena that enable them to be used as optical ...

  8. Fundamental absorption edge in CuIn5Se8 and CuGa3Se5 single crystals

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-03

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

  11. Cs2SeO4-UO2SeO4-H2O system at 25 deg C

    International Nuclear Information System (INIS)

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

    1987-01-01

    Using the method of isothermal solubility at 25 deg C the interaction of cesium and uranyl selenates in aqueous solution is studied. Formation of congruently soluble Cs 2 UO 2 (SeO 4 ) 2 x2H 2 O and Cs 2 (UO 2 ) 2 x(SeO 4 ) 3 is ascertained, their crystallographic characteristics being determined

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

    International Nuclear Information System (INIS)

    Kafashan, Hosein; Azizieh, Mahdi; Balak, Zohre

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-15

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

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

    Science.gov (United States)

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

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

  15. ¿Qué se juega al jugar un juego?

    Directory of Open Access Journals (Sweden)

    Kalejman, Cecilia

    2012-06-01

    Full Text Available En el presente artículo se considera el juego en relación a la niñez. Se indaga acerca del papel que juega el juego en la niñez intentando responder a diversas preguntas, entre ellas la más importante: ¿Qué significa jugar? A lo largo de esta etapa del desarrollo en que comienza a constituirse la subjetividad del individuo el juego constituye, sin dudas, un factor central, una herramienta fundamental en el desarrollo. Juego no es sólo el juego dramático, también consideramos para nuestro análisis aquellas modalidades de juego que se transmiten de generación en generación, juegos de construcción, los dibujos, teniendo en cuenta asimismo los objetos utilizados en los juegos, los contenidos de los mismos, los espacios en los que se desarrollan. Se piensa y se interpreta al juego, como un derecho y como un modo de expresión del niño, se finaliza este desarrollo con una conclusión acera del juego y el espacio que ocupa en la vida cotidiana.

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

    Science.gov (United States)

    Khafajeh, R; Molaei, M; Karimipour, M

    2017-06-01

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

  17. Novel mechanical behaviors of wurtzite CdSe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Bing [Shanghai Normal University, Department of Physics (China); Chen, Li [MCPHS University, School of Arts and Sciences (United States); Xie, Yiqun; Feng, Jie; Ye, Xiang, E-mail: yexiang@shnu.edu.cn [Shanghai Normal University, Department of Physics (China)

    2015-09-15

    As an important semiconducting nanomaterial, CdSe nanowires have attracted much attention. Although many studies have been conducted in the electronic and optical properties of CdSe NWs, the mechanical properties of Wurtzite (WZ) CdSe nanowires remain unclear. Using molecular dynamics simulations, we have studied the tensile mechanical properties and behaviors of [0001]-oriented Wurtzite CdSe nanowires. By monitoring the stretching processes of CdSe nanowires, three distinct structures are found: the WZ wire, a body-centered tetragonal structure with four-atom rings (denoted as BCT-4), and a structure that consists of ten-atom rings with two four-atom rings (denoted as TAR-4) which is observed for the first time. Not only the elastic tensile characteristics are highly reversible under unloading, but a reverse transition between TAR-4 and BCT-4 is also observed. The stretching processes also have a strong dependence on temperature. A tubular structure similar to carbon nanotubes is observed at 150 K, a single-atom chain is formed at 300, 350 and 450 K, and a double-atom chain is found at 600 K. Our findings on tensile mechanical properties of WZ CdSe nanowires does not only provide inspiration to future study on other properties of CdSe nanomaterials but also help design and build efficient nanoscale devices.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2016-08-15

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

  20. Social Set Visualizer (SoSeVi) II

    DEFF Research Database (Denmark)

    Flesch, Benjamin; Vatrapu, Ravi

    2016-01-01

    This paper reports the second iteration of the Social Set Visualizer (SoSeVi), a set theoretical visual analytics dashboard of big social data. In order to further demonstrate its usefulness in large-scale visual analytics tasks of individual and collective behavior of actors in social networks......, the current iteration of the Social Set Visualizer (SoSeVi) in version II builds on recent advancements in visualizing set intersections. The development of the SoSeVi dashboard involved cutting-edge open source visual analytics libraries (D3.js) and creation of new visualizations such as of actor mobility...

  1. Se interlayer in CIGS absorption layer for solar cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung-Kyu; Sim, Jae-Kwan [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of); Kissinger, N.J. Suthan [Department of General Studies, Physics Group, Jubail University College, Royal Commission for Jubail, Jubail 10074 (Saudi Arabia); Song, Il-Seok; Kim, Jin-Soo; Baek, Byung-Joon [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of); Lee, Cheul-Ro, E-mail: crlee7@jbnu.ac.kr [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of)

    2015-06-05

    Highlights: • Se interlayer is deposited between the CuGa and CuIn/In/Mo/STS stacked layer. • Both CIG precursor layers were selenized at 500 °C for 1 h. • SIMS depth profile shows that Ga distribution is uniform by Se interlayer. • The efficiency was improved for the CIGS solar cell by Se interlayer. - Abstract: A CIGS absorber layer with high gallium contents in the space-charge region can reduce the carrier recombination and improve the open circuit voltage V{sub oc}. Therefore, controlling Ga grading on top of CIGS thin film solar cells is the main objective of this experiment. To reduce Selenium (Se) vacancy, it is important that the diffusion of Ga elements into Se vacancy between Mo back contact and CIGS absorption layer would be controlled. In order to reduce Se vacancy and confirm Ga inter-diffusion, two CIGS solar cells were fabricated by converting CIG precursor with and without Se interlayer. The copper-indium metallic precursors were fabricated corresponding to the sequence CuIn/In/Mo/STS on stainless steel (STS) substrates by sequential direct current magnetron sputtering while Se layer was evaporated by rapid thermal annealing (RTA) system to obtain a Se/CuIn/In/Mo/STS stack. CuGa precursor layer was also fabricated on the Se/CuIn/In/Mo/STS stack. Finally, both CuGa/Se/CuIn/In/Mo/STS and CuGa/CuIn/In/Mo/STS stacks were selenized at 500 °C for 1 h. It was clearly observed from the secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) that there was a change between the fabricated CIGS absorption layers and the amount of Ga elements. Furthermore, the Ga elements gradually decreased from the top to the bottom layer of the CIGS absorption layer. We also discussed the effect of Se interlayer in the CIGS absorption layer and its influence on the solar cell’s performance.

  2. Reversible ultrafast melting in bulk CdSe

    International Nuclear Information System (INIS)

    Wu, Wenzhi; He, Feng; Wang, Yaguo

    2016-01-01

    In this work, transient reflectivity changes in bulk CdSe have been measured with two-color femtosecond pump-probe spectroscopy under a wide range of pump fluences. Three regions of reflectivity change with pump fluences have been consistently revealed for excited carrier density, coherent phonon amplitude, and lattice temperature. For laser fluences from 13 to 19.3 mJ/cm 2 , ultrafast melting happens in first several picoseconds. This melting process is purely thermal and reversible. A complete phase transformation in bulk CdSe may be reached when the absorbed laser energy is localized long enough, as observed in nanocrystalline CdSe

  3. Development of conductive nanotemplates on ZnSe

    International Nuclear Information System (INIS)

    Monaico, Eduard; Tiginyanu, Ion; Colibaba, Gleb; Nedeoglo, D.D.; Cojocaru, Ala; Foell, Helmut

    2011-01-01

    We demonstrate the possibility to fabricate arrays of pores oriented perpendicular and parallel to the top surface of the ZnSe nanotemplate. The control of material conductivity allows one to produce porous ZnSe samples with the mean pore diameter and characteristic skeleton wall thickness from several hundreds of nanometers to about 15 nm. In addition, electrochemical treatment of ZnSe single crystals using photoresist masks allows one to prepare buried porous structures with pores directed parallel to the top template surface, which is especially important for photonic applications.

  4. Magnetic study of Fe-doped CdSe nanomaterials

    International Nuclear Information System (INIS)

    Das, Sayantani; Banerjee, Sourish; Sinha, T. P.

    2016-01-01

    Nanoparticles of pure and iron (50 %) doped cadmium selenide (CdSe) have been synthesized by soft chemical route. EDAX analysis supports the inclusion of Fe into CdSe nanoparticles. The average particle size of pure and doped CdSe is found to be ∼50 nm from scanning electron microscopy (SEM). Magnetization of the samples are measured under the field cooled (FC) and zero field cooled (ZFC) modes in the temperature range from 5K to 300K applying a magnetic field of 500Oe. Field dependent magnetization (M-H) measurement indicates presence of room temperature (RT) paramagnetism and low temperature (5K) ferromagnetism of the sample.

  5. Polybutylcyanoacrylate nanoparticles for the delivery of [75Se]norcholestenol

    International Nuclear Information System (INIS)

    Kreuter, J.; Wilson, C.G.

    1983-01-01

    Polybutylcyanoacrylate nanoparticles have been used for the intravenous and intramuscular administration of a steroidal material ([ 75 Se]norcholestenol) to the rabbit. Whole body profiles of 75 Se, obtained using a gamma camera over a period of 30 days, show that the [ 75 Se]norcholestenol is retained for a longer period of time with the nanoparticle system than for the control system where the drug was dissolved in a micellar system. In vitro dialysis experiments indicate that the thermodynamic activity of the drug can be increased by its incorporation within nanoparticles. This increased activity may affect the distribution of the drug into body tissues. (Auth.)

  6. Se interlayer in CIGS absorption layer for solar cell devices

    International Nuclear Information System (INIS)

    Lee, Seung-Kyu; Sim, Jae-Kwan; Kissinger, N.J. Suthan; Song, Il-Seok; Kim, Jin-Soo; Baek, Byung-Joon; Lee, Cheul-Ro

    2015-01-01

    Highlights: • Se interlayer is deposited between the CuGa and CuIn/In/Mo/STS stacked layer. • Both CIG precursor layers were selenized at 500 °C for 1 h. • SIMS depth profile shows that Ga distribution is uniform by Se interlayer. • The efficiency was improved for the CIGS solar cell by Se interlayer. - Abstract: A CIGS absorber layer with high gallium contents in the space-charge region can reduce the carrier recombination and improve the open circuit voltage V oc . Therefore, controlling Ga grading on top of CIGS thin film solar cells is the main objective of this experiment. To reduce Selenium (Se) vacancy, it is important that the diffusion of Ga elements into Se vacancy between Mo back contact and CIGS absorption layer would be controlled. In order to reduce Se vacancy and confirm Ga inter-diffusion, two CIGS solar cells were fabricated by converting CIG precursor with and without Se interlayer. The copper-indium metallic precursors were fabricated corresponding to the sequence CuIn/In/Mo/STS on stainless steel (STS) substrates by sequential direct current magnetron sputtering while Se layer was evaporated by rapid thermal annealing (RTA) system to obtain a Se/CuIn/In/Mo/STS stack. CuGa precursor layer was also fabricated on the Se/CuIn/In/Mo/STS stack. Finally, both CuGa/Se/CuIn/In/Mo/STS and CuGa/CuIn/In/Mo/STS stacks were selenized at 500 °C for 1 h. It was clearly observed from the secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) that there was a change between the fabricated CIGS absorption layers and the amount of Ga elements. Furthermore, the Ga elements gradually decreased from the top to the bottom layer of the CIGS absorption layer. We also discussed the effect of Se interlayer in the CIGS absorption layer and its influence on the solar cell’s performance

  7. The RiSE climbing robot: body and leg design

    Science.gov (United States)

    Saunders, A.; Goldman, D. I.; Full, R. J.; Buehler, M.

    2006-05-01

    The RiSE robot is a biologically inspired, six legged climbing robot, designed for general mobility in scansorial (vertical walls, horizontal ledges, ground level) environments. It exhibits ground reaction forces that are similar to animal climbers and does not rely on suction, magnets or other surface-dependent specializations to achieve adhesion and shear force. We describe RiSE's body and leg design as well as its electromechanical, communications and computational infrastructure. We review design iterations that enable RiSE to climb 90° carpeted, cork covered and (a growing range of) stucco surfaces in the quasi-static regime.

  8. Colegio Nuestra Señora del Carmen-Ikastetxea

    OpenAIRE

    García Sedano, Esther

    2012-01-01

    Este trabajo se centra en la atención a la diversidad, enfocado en aquellos alumnos con necesidades educativas especiales por dificultades de aprendizaje, por trastorno de déficit de atención, dislexia, inteligencia límite (bordeline) y síndrome de triple X. Con él también se pretende la adaptación de niños de nacionalidad china a nuestros hábitos y se les ilustra en el método silábico para que aprendan el idioma del castellano con prontitud para evitar la dislexia, entre otros problemas. ...

  9. Narrativas sobre conjugalidade de mulheres que se relacionam com crossdressers

    OpenAIRE

    Vencato, Anna Paula

    2017-01-01

    Resumo: Este texto discute dados coletados em pesquisa com mulheres que se identificam como “esposas” ou “S/O’s” de homens que “praticam crossdressing”. É, também, um desdobramento de minha tese de Doutorado, sobre como homens que se identificam como crossdressers negociam esta prática em suas vidas cotidianas. A pesquisa parte de uma etnografia e é complementada por entrevistas semiestruturadas com estas mulheres. Busca-se compreender como elas lidam com as tensões relativas às convenções so...

  10. ¿Con humor se explica y se aprende una lengua mejor?

    Directory of Open Access Journals (Sweden)

    Ricard Morant

    2010-11-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} En el siguiente artículo nos proponemos reflexionar sobre la importancia del humor como estrategia didáctica. Para plantear si “el enseñar contento y el aprender con alegría” pueden aumentar la eficacia en el proceso de enseñanza-aprendizaje presentaremos en el primer apartado las ideas de partida, mostraremos cómo a pesar de las múltiples ventajas que puede aportar el humor a las aulas, se omite su empleo por la existencia de ciertos prejuicios y temores. Seguidamente, y a modo de ejemplo, expondremos, un tema, el tabú lingüístico, en clave de humor con el propósito de acabar planteando si el género humorístico beneficia o perjudica la práctica docente al hablar sobre una lengua o al tratar de enseñarla.

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  12. Cuando la Respuesta Penal a la Violencia Sexista se Vuelve contra las Mujeres: las Contradenuncias (When the Criminal Response to Gender-based Violence Turns Against Women: counterclaims

    Directory of Open Access Journals (Sweden)

    Miren Ortubay Fuentes

    2015-06-01

    Full Text Available In some respects, the legal response to violence against women has gone ahead of cultural change. This gap allows the resurgence of old myths and strategies against gender equality, such as the so-called "counterclaim", that is, the man who has been denounced as an aggressor by his partner, in turn, accuses her from violence against him. In addition to the context in which these cross complaints arise, this paper presents the results of a study based on a group of sentences pronounced in Biscay, in which both man and woman are condemned for gender-based violence. It concludes that, beyond the principles, the criminal justice system treats women more rigorously.En algunos aspectos, la respuesta legal frente a la violencia contra las mujeres ha ido por delante del cambio cultural. Ese desfase abre una grieta por la que resurgen viejos mitos y estrategias contrarias a la igualdad de género, como la denominada "contradenuncia", que consiste en que el hombre que ha sido denunciado como agresor por su pareja, a su vez, acusa a ésta de ejercer violencia contra él. Además del contexto en el que dichas denuncias cruzadas se plantean, se exponen los resultados del análisis realizado sobre un grupo de sentencias -dictadas en Bizkaia- en las que se condena tanto al hombre como a la mujer por violencia de género, llegando a la conclusión de que, más allá de los principios, el sistema penal trata a las mujeres con mayor rigor punitivo. DOWNLOAD THIS PAPER FROM SSRN: http://ssrn.com/abstract=2612114

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

    Directory of Open Access Journals (Sweden)

    Makinaga Ayano

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-09-01

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

  15. Radiation stability of methionine-35S and selenomethionine-75Se

    International Nuclear Information System (INIS)

    Galateanu, I.; Lungu, V.V.; Viorel, D.

    1976-01-01

    The radiation stability of methionine- 35 S and selenomethionine 75 Se was investigated using the methods of thin-layer chromatography, gas chromatography and ESR. Radiation decomposition of methionine- 35 S mainly consists in an oxidation process and in the release of volatile products. The ESR-spectra of irradiated DL-methionine indicated a strong localization of the unpaired electrons on sulfur atoms. Radiation damage to selenomethionine- 75 Se as a function of radiation dose proved an increased stability of this compound and its radiation decomposition consists in the formation of oxidized products and by direct rupture of the selenium bounds accompanied by the formation of volatile compounds like CH 3 SEH and SeH 2 . The self-radiolysis of the aqueous solution of selenomethionine- 75 Se during its storage in air leads, however, to a lower decomposition rate which consists in the release of inorganic selenium and in an oxidation process. (author)

  16. Deelnemende bestuur as funksie van bestuurders se selfkonsep en mensbeskouing

    Directory of Open Access Journals (Sweden)

    W. P. Visser

    1997-06-01

    Opsomming Die literatuur toon 'n leemte aan navorsing betreffende individuele attribute wat 'n persoon tot deelnemende bestuur mag predisponeer. Met hierdie studie is ondersoek ingestel na die verband tussen twee suike attribute, naamlik selfkonsep en mensbeskouing enersyds, en gewilligheid tot deelnemende bestuur andersyds. 'n Instrument gebaseer op McGregor se teorie, is ontwikkel om mensbeskouing binne werkkonteks te meet. Met behulp van faktorontleding is twee faktore onttrek wat onderskeidelik intrinsieke en ekstrinsieke aspekte van 'n persoon se beskouing van ander se houding teenoor werk meet. 'n Gelykkansige steekproef uit 233 toesighouers van 'n openbare versorgingsonderneming het 196 bruikbare vraelyste opgelewer. 'n Beduidende verband tussen selfkonsep en mensbeskouing enersyds, en gewilligheid tot deelnemende bestuur andersyds, is met behulp van kanoniese korrelasie gevind (r =0,601; p < 0,01. Die bevinding bied steun vir McGregor se teorie dat 'n gunstige mensbeskouing tot 'n deelnemende bestuurstyl lei.

  17. Electronic Properties of Graphene-PtSe2 Contacts.

    Science.gov (United States)

    Sattar, Shahid; Schwingenschlögl, Udo

    2017-05-10

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe 2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe 2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe 2 and a p-type Schottky contact with bilayer PtSe 2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  18. Electronic Properties of Graphene–PtSe2 Contacts

    KAUST Repository

    Sattar, Shahid

    2017-04-26

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe2 and a p-type Schottky contact with bilayer PtSe2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  19. Preparation of PbSe nanoparticles by electron beam irradiation ...

    Indian Academy of Sciences (India)

    Wintec

    Recently, the synthesis of binary metal selenides of group. IV has been investigated ... Pb(Ac)2 and Se powder reacted ... hol (PVA), potassium hydroxide (KOH), and isopropyl. *Author for ... 40 ml distilled water and reacted adequately. Subse-.

  20. Thermal characterization of Se-Te thin films

    Czech Academy of Sciences Publication Activity Database

    Svoboda, R.; Kincl, Miloslav; Málek, J.

    2015-01-01

    Roč. 644, 25 September (2015), s. 40-46 ISSN 0925-8388 Institutional support: RVO:61389013 Keywords : krystallization kinetics * DSC * Se-Te glass Subject RIV: CA - Inorganic Chemistry Impact factor: 3.014, year: 2015

  1. ZnSe thin films by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, C.D.; Patil, P.S.; Tributsch, H. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CS, Glienicker Strasse-100, D-14109 Berlin (Germany); Ennaoui, A. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CG, Glienicker Strasse-100, D-14109 Berlin (Germany)

    1998-09-04

    The ZnSe thin films have been deposited onto glass substrates by the simple chemical bath deposition method using selenourea as a selenide ion source from an aqueous alkaline medium. The effect of Zn ion concentration, bath temperature and deposition time period on the quality and thickness of ZnSe films has been studied. The ZnSe films have been characterized by XRD, TEM, EDAX, TRMC (time-resolved microwave conductivity), optical absorbance and RBS techniques for their structural, compositional, electronic and optical properties. The as-deposited ZnSe films are found to be amorphous, Zn rich with optical band gap, Eg, equal to 2.9 eV

  2. Chemical bath ZnSe thin films: deposition and characterisation

    Science.gov (United States)

    Lokhande, C. D.; Patil, P. S.; Ennaoui, A.; Tributsch, H.

    1998-01-01

    The zinc selenide (ZnSe) thin films have been deposited by a simple and inexpensive chemical bath deposition (CBD) method. The selenourea was used as a selenide ion source. The ZnSe films have been characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDAX), Rutherford back scattering (RBS), and optical absorption. The as-deposited ZnSe films on various substrates are found to be amorphous and contain O2 and N2 in addition to Zn and Se. The optical band gap of the film is estimated to be 2.9 eV. The films are photoactive as evidenced by time resolved microwave conductivity (TRMC).

  3. Electronic Properties of Graphene–PtSe2 Contacts

    KAUST Repository

    Sattar, Shahid; Schwingenschlö gl, Udo

    2017-01-01

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe2 and a p-type Schottky contact with bilayer PtSe2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  4. Optical Properties of Multilayer CdSe/POLYMER Structures

    Science.gov (United States)

    Red'Ko, V. P.; Voitenkov, A. I.; Kovalenko, O. E.

    The effects of preparation condition, concentration and size of particles upon optical and photoelectrical characteristics of multilayer structures CdSe/polyethylene terephthalate obtained by electron-beam evaporation were investigated.

  5. Processing and characterization of bulk FeSe

    Czech Academy of Sciences Publication Activity Database

    Muralidhar, M.; Hanai, T.; Furutani, K.; Diko, P.; Jirsa, Miloš; Murakami, M.

    2016-01-01

    Roč. 4, č. 3 (2016), s. 109-115 ISSN 2328-2231 Institutional support: RVO:68378271 Keywords : FeSe * x-ray diffraction * magnetization measurements * SEM * EDX analysis Subject RIV: BM - Solid Matter Physics ; Magnetism

  6. Fabrication and Photocatalytic Properties of ZnSe Nanorod Films

    Directory of Open Access Journals (Sweden)

    Jiajia Yin

    2016-01-01

    Full Text Available ZnSe nanorod films grown on fused quartz glass substrates via a simple two-step synthesis protocol were demonstrated to be environmentally safe and effective recyclable photocatalysts. These films showed greatly enhanced photocatalytic activity compared to pulsed laser deposition ZnSe films in the degradation of methyl orange dye solutions. The well-crystalized ZnSe nanorods had a length of 15 µm and a diameter of 200 nm and were densely grown on the substrate. The morphology, crystal structure, crystal phase, and photophysical properties of the ZnSe nanorod films were investigated using field-emission scanning electron microscopy (FE-SEM, UV-Vis spectroscopy, X-ray diffraction (XRD, transmission electron microscopy (TEM, and high resolution transmission electron microscopy (HRTEM.

  7. Petrus Abelardus se Megariaanse argument in Theologia 'Scholarium'

    African Journals Online (AJOL)

    Test

    7 Jun 2011 ... Martin Heidegger se beroemde opmerking (1958:37; 'Die wêreld word donker . .... Luther en die Wes-Europese Kerkhervorming}]). 7. ...... King, P., 2004, 'Peter Abelard', Stanford Encyclopedia of Philosophy, viewed February.

  8. Nematicity, magnetism and superconductivity in FeSe.

    Science.gov (United States)

    Böhmer, Anna E; Kreisel, Andreas

    2018-01-17

    Iron-based superconductors are well known for their complex interplay between structure, magnetism and superconductivity. FeSe offers a particularly fascinating example. This material has been intensely discussed because of its extended nematic phase, whose relationship with magnetism is not obvious. Superconductivity in FeSe is highly tunable, with the superconducting transition temperature, T c , ranging from 8 K in bulk single crystals at ambient pressure to almost 40 K under pressure or in intercalated systems, and to even higher temperatures in thin films. In this topical review, we present an overview of nematicity, magnetism and superconductivity, and discuss the interplay of these phases in FeSe. We focus on bulk FeSe and the effects of physical pressure and chemical substitutions as tuning parameters. The experimental results are discussed in the context of the well-studied iron-pnictide superconductors and interpretations from theoretical approaches are presented.

  9. Hjemløse borgeres sygdom og brug af sundhedsydelser

    DEFF Research Database (Denmark)

    Benjaminsen, Lars; Birkelund, Jesper Fels; Enemark, Morten Holm

    sygdom er meget udbredt blandt hjemløse borgere. Men også når man korrigerer for misbrug og psykisk sygdom, har de hjemløse borgere forøget risiko for en række sygdomme som fx infektionssygdomme, lungebetændelse og KOL. Undersøgelsen identificerer også et merforbrug af sundhedsydelser blandt de hjemløse...... tandlæge og speciallæge. Den stærke oversygelighed i gruppen af hjemløse borgere peger generelt på et behov for at medtænke en sundhedsmæssig dimension i den sociale støtte til disse borgere. Undersøgelsen er finansieret af Helsefonden....

  10. Sample (S): SE57_S08 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE57_S08 Lotus japonicus (accessions B129 gifu and MG20 miyakojima) Lotus japonicus... NCBI taxonomy:34305 Lotus japonicus accessions were a gift from Dr. Toshio Aoki (Nihon University, Japan). ...

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

    Science.gov (United States)

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

    2017-10-05

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

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

    Science.gov (United States)

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

    2015-11-02

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  14. Annotation Method (AM): SE7_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE7_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  15. On the reversibility window in binary As-Se glasses

    Energy Technology Data Exchange (ETDEWEB)

    Golovchak, R. [Lviv Scientific Research Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv UA-79031 (Ukraine); Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestochowa PL-42201 (Poland); Faculty of Physics of Opole University of Technology, 75 Ozimska str., Opole PL-45370 (Poland); Shpotyuk, O. [Lviv Scientific Research Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv UA-79031 (Ukraine); Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestochowa PL-42201 (Poland)], E-mail: shpotyuk@novas.lviv.ua; Kozdras, A. [Faculty of Physics of Opole University of Technology, 75 Ozimska str., Opole PL-45370 (Poland)

    2007-10-29

    Physical ageing effects caused by prolonged natural storage are recorded for binary As{sub x}Se{sub 1-x} glasses with 0.2{<=}x<0.4. Their origin is associated with pure 'shrinkage' of under-constrained glass networks. It is shown that only stoichiometric As{sub 2}Se{sub 3} composition, which network is formed by a so-called self-organized phase, possesses the ideal non-ageing ability.

  16. Se aprende poco : ¿Qué podemos hacer?

    OpenAIRE

    Quinquer, Dolors

    2006-01-01

    La situación en las aulas es más compleja, heterogénea y pluricultural que antes; las competencias que se han de desarrollar se han diversificado, ahora son cognitivas, éticas y sociales, mientras que los marcos organizativos siguen tan rígidos como siempre. En este contexto, comparando España con otros países, parece que los alumnos aprenden poco.¿Qué podemos hacer? 

  17. Annotation Method (AM): SE2_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE2_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  18. Annotation Method (AM): SE4_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE4_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  19. Annotation Method (AM): SE9_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE9_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  20. Annotation Method (AM): SE3_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE3_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  1. Annotation Method (AM): SE6_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE6_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  2. Annotation Method (AM): SE1_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE1_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  3. Annotation Method (AM): SE8_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE8_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  4. Annotation Method (AM): SE5_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE5_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  5. Det monstrøse i Ezekiels vision

    DEFF Research Database (Denmark)

    Nielsen, Kirsten

    2011-01-01

    Artiklen viser, hvordan det monstrøse introduceres i Ezekiels Bog kap. 1 i form af nogle sammensatte levende væsener, der har træk hentet fra både menneske- og dyreverdenen. Det monstrøse består i denne overskridelse af de gængse grænser og problematiserer dermed de velkendte klassifikationer. Og...

  6. 75Se-labelled cortisol in analysis by competition

    International Nuclear Information System (INIS)

    Glover, J.S.; Chambers, V.E.M.

    1975-01-01

    Selenium 75 has nuclear properties very suitable for the labelling of steroids used as tracers in competition analysis. A method of preparing a selenium-labelled cortisol derivative, 75 Se methylselenoprednisolone, is described. A system based on bonding competition between plasma cortisol and 75 Se methylselenoprednisolone on transcortine was studied, the separation taking place on a Sephadex adsorbant. An early analysis with highly stable reagents was achieved [fr

  7. de drogas que se consumen en su medio

    Directory of Open Access Journals (Sweden)

    José F. Enríquez Bielma

    2006-01-01

    Full Text Available Las adicciones son un problema de salud pública. Se estima que en México 3.5 millones de personas entre 12 a los 65 años han consumido algún tipo de drogas. A pesar de los avances en los estudios, se ha dejado de lado el carácter cultural que tiene la adicción. Con este estudio, se deseba conocer qué saben los estudiantes de segundo de secundaria sobre cuáles son las drogas que se consumen en su medio. Se llevó a cabo un estudio observacional con un muestreo aleatorio, con múltiples etapas y proporcional al tamaño en escuelas públicas y privadas. En total se estudiaron 42 escuelas del municipio de León, Gto., México de las cuales el 76.2% lo conformaron las escuelas públicas y el resto las escuelas privadas. Refirieron que conocen que se consumen, en su medio, 11 tipos de drogas. El 88% mencionó a la cocaína en primer lugar, en segundo lugar con un 85% la marihuana, siguiendo las tachas en un 62% y el pegamento en un 49%. En cuanto a los nombres que los estudiantes le dan a las drogas, estos van desde 23 hasta los 4 nombres, siendo la marihuana a la que se le da el mayor número de nombres, seguidos de la cocaína y el éxtasis.

  8. ¿Se ha abierto el sistema político colombiano? Una evaluación de los procesos de cambio (1970-1998

    Directory of Open Access Journals (Sweden)

    Francisco GUTIÉRREZ SANÍN

    2009-11-01

    Full Text Available RESUMEN: A pesar de la continuidad democrática colombiana, existe una prolongada crisis de su sistema político que se refleja en varias dimensiones. Esta crisis se ha atribuido tradicionalmente a los efectos que se derivan del «cierre» del sistema político colombiano. A través del análisis de las diferentes dimensiones del «cierre político», indicando qué tipo de implicaciones tiene cada una de ellas para el sistema y cómo han evolucionado, se trata de ver si los defectos del sistema político que tradicionalmente se han atribuido a este «cierre» son en realidad causa exclusiva del mismo o bien pudieran deberse en parte a la apertura política del sistema. El paso del cierre a la apertura política tiene como consecuencia que durante un período de tiernpo relativamente prolongado los indicadores de convivencia y cívilidad empeoren, éste sería el caso de Colombia, donde en las últimas décadas se han dado una serie de aperturas y cierres simultáneos, siendo esta tensión entre cierre y apertura la que ha provocado avances, estancamientos y retrocesos democráticos simultaneos.ABSTRACT: In spite of colombian democratic continuity, there is a extend crisis in its political system that reflects in several aspects. This crisis has been derived traditionally from «the closing» of the colombian political system. Through the analysis and evolutions of several aspects of «political closing» and its implies on the system, it is tried to proof if they are cause of the defects of the political system. The transit from the closing to the opening can deteriorate the indicators of coexistence and public spirit, there's the case of Colombia, where in the last decades the excessives openings and closings have simultaneous advances and breaking downs in the democracy.

  9. Synthesis and biodistribution of 75Se-dinonyl-diselenide

    International Nuclear Information System (INIS)

    Liu, Y.F.; Qian, H.Q.; Zhang, Q.X.; Wang, X.Y.; Sun, J.G.; Li, B.Z.; Zhang, W.J.

    1985-01-01

    Selenium-75-labelled dinonyl-diselenide, C 9 H 19 75 SeSeC 9 H 19 , was synthesized and identified. It was injected into white rats in order to observe the selenium distribution in the tissues using inorganic 75 SeO 2 as the control agent. The sequence order of the 75 Se-dinonyl-diselenide uptake by tissues was: pancreas, muscles, stomach, liver, kidneys, spleen, blood, lungs, heart, brain, eyes. A very high accumulation of 75 Se-dinonyl-diselenide in the pancreas was observed, similar to that of the pancreatic imaging agent 75 Se-methionine. Furthermore, the enzymatic activity of glutathione peroxidase in the case of organic diselenide injection was higher than that measured for selenite. Selenium of dinonyl-diselenide was more effective and retainable in the process of converting itself to selenium-containing enzyme via the metabolic reactions. It may be advisable to replace inorganic sodium selenite by organic selenium compounds. Sodium selenite has been widely used in the prevention of the Keshan disease in China. (author)

  10. Identification QTLs Controlling Genes for Se Uptake in Lentil Seeds.

    Directory of Open Access Journals (Sweden)

    Duygu Ates

    Full Text Available Lentil (Lens culinaris Medik. is an excellent source of protein and carbohydrates and is also rich in essential trace elements for the human diet. Selenium (Se is an essential micronutrient for human health and nutrition, providing protection against several diseases and regulating important biological systems. Dietary intake of 55 μg of Se per day is recommended for adults, with inadequate Se intake causing significant health problems. The objective of this study was to identify and map quantitative trait loci (QTL of genes controlling Se accumulation in lentil seeds using a population of 96 recombinant inbred lines (RILs developed from the cross "PI 320937" × "Eston" grown in three different environments for two years (2012 and 2013. Se concentration in seed varied between 119 and 883 μg/kg. A linkage map consisting of 1,784 markers (4 SSRs, and 1,780 SNPs was developed. The map spanned a total length of 4,060.6 cM, consisting of 7 linkage groups (LGs with an average distance of 2.3 cM between adjacent markers. Four QTL regions and 36 putative QTL markers, with LOD scores ranging from 3.00 to 4.97, distributed across two linkage groups (LG2 and LG5 were associated with seed Se concentration, explaining 6.3-16.9% of the phenotypic variation.

  11. Preparation and characterization of polycrystalline n-CdSe photoelectrode

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, T. K.

    1979-01-01

    Thin layers of polycrystalline p-CdSe were prepared by the simultaneous eletrodeposition of cadmium and selenium from cadmium sulfate and selenious acid in a sulfuric acid solution at pH 0-1 on a titanium substrate. The adherence of the layers to the substrate, stoichiometric ratio of Cd:Se and photovoltaic property of the film depend upon the molar ratio of CdSO/sub 4/ and H/sub 2/SeO/sub 3/ and current density as well as on the pH and temperature of the electrolysis bath. On increasing the current density or the ratio of CdSO/sub 4/:H/sub 2/SeO/sub 3/ in the electrolysis bath, the Cd:Se of the electrodeposit increased. The semiconductor films so prepared were annealed at 550/sup 0/C in a nitrogen atmosphere, followed by etching in an acid solution and then used to construct the photo-electrochemical cell, Ti/CdSe/Na/sub 2/S-Na/sub 2/S/sub x/(aq.)/Pt, and the current-voltage curves have been studied. 11 references.

  12. Structural manifestations of aging in Se-rich glasses

    Science.gov (United States)

    Dash, S.; Ravindren, S.; Chen, P.; Boolchand, P.

    2015-03-01

    We examine weakly cross-linked GexSe100-x (0%modulated DSC and Raman scattering experiments. Homogeneity of melts was carefully verified using FT-Raman line profiling. Upon aging at RT for 4 months, we find the width of the glass transition W(x) steadily decreasing from 10C at 7% Ge to 2C for pure Se. The 5-fold reduction of W(x) with a decrease of Ge content is accompanied by a 2-fold increase in the non-reversing enthalpy. Rejuvenation of the aged glasses changes W(x) from 15C at 7% Ge to 7C for pure Se. Tg is found to decrease upon rejuvenation with the difference (Tg(aged)-Tg(rejuv)) showing a maximum near 3% Ge and vanishing for pure Se and 6% of Ge, which are topological thresholds. These results in Se-rich glasses are consistent with aging induced decoupling of Se8 crowns and growth of extended range structural correlations between polymeric Sen chains due to lone pair interactions. At higher x, near 8-10% of Ge, eutectic effects are manifested. Work supported by NSF Grant DMR 08-53957.

  13. Agentive reflexive clitics and transitive 'se' constructions in Spanish

    Directory of Open Access Journals (Sweden)

    Grant Armstrong

    2013-11-01

    Full Text Available This paper investigates the structure of transitive sentences that contain a non-doubling reflexive clitic such as Juan se lavó todos los platos and María se leyó un libro. Though these are traditionally labelled unselected (non-core agreeing datives or aspectual datives, I argue that this label obscures a relevant difference between two classes of constructions. agentive reflexive clitic (= ARC constructions are characterized by a uniform set of effects on the external argument (= it must be an agent and the aspectual interpretation of the VP (= it must be an accomplishment. On the other hand, transitive se clitic (= TSC constructions do not impose any type of uniform restrictions on the kind of external argument they take or on the aspectual interpretation of the VP. I propose that the difference between these two constructions may be captured by treating se in the ARC construction as the realization of a special vDO head, based on an idea in Folli & Harley (2005, while se in the TSC construction is generated in the complement position of the verb and incorporates into V, forming a complex predicate, following work by De Cuyper (2006, MacDonald (2004, 2008 and MacDonald & Huidobro (2010. It is shown that many of the empirical and theoretical disagreements that plague the literature on the role of non-doubling se in transitive sentences have a simple solution given the new division established here

  14. PbSe nanocubes obtained by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: hrojasc@ipn.mx [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM (Mexico); Achimovicova, M. [Slovak Academy of Sciences, Institute of Geotechnics (Slovakia); Daneu, N. [Jozef Stefan Institute, Department for Nanostructured Materials (Slovenia); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN (Mexico)

    2012-06-15

    In this study, PbSe nanocubes were obtained by high-energy milling, and their optical properties were investigated by measuring the UV-VIS-IR spectra in the range of 200-2,000 nm. The optical absorption of all samples showed a strong UV emission band at 1.45 eV. Previously, to obtain only PbSe nanocubes, an intermediate phase was identified, PbSeO{sub 3}. Although both PbSeO{sub 3} and PbSe were traced through this study, a major effort is devoted to characterize the latter. To trace how chemical transitions evolve from precursors to PbSe, X-ray diffraction and Rietveld refinement were carried out. Therefore, the following parameters were evaluated as a function of milling time: phase percentages, area-to-volume ratio, average crystallite dimensions, specific surface area, and morphology changes. To corroborate previous findings, nitrogen adsorption and transmission electron microscopy techniques were used. All the set experimental results unambiguously confirm that crystallites show a cubic morphology, with its average crystallite size distribution being around 24 nm.

  15. Un estudio preliminar sobre la recepción de las campañas de violencia de género televisivas del Ministerio de Sanidad, Política Social e Igualdad (2008-2011

    Directory of Open Access Journals (Sweden)

    Emma Camarero Calandria

    2013-01-01

    Full Text Available En el presente artículo se dan a conocer los primeros resultados obtenidos del estudio piloto realizado sobre las campañas de violencia de género televisivas realizadas por el Ministerio de Sanidad, Igualdad y Políticas Sociales en el período 2008-2011. La investigación tiene como objetivo principal analizar la percepción de los ciudadanos y ciudadanas sobre estas campañas de prevención de violencia de género. Especialmente se trata de saber si son instrumentos eficaces y realmente sensibilizadores en la lucha contra la violencia de género o por el contrario, los medios utilizados en estas campañas resultan ineficaces o insuficientes. Este estudio previo trata también de establecer la validez del cuestionario utilizado, una vez estudiados los resultados obtenidos en esta primera fase de la investigación. Tras su análisis, dichos resultados serán el germen de un macroestudio posterior donde se ampliará la muestra de esta investigación sobre las campañas televisivas contra la violencia de género en España.

  16. NaviSE: superenhancer navigator integrating epigenomics signal algebra.

    Science.gov (United States)

    Ascensión, Alex M; Arrospide-Elgarresta, Mikel; Izeta, Ander; Araúzo-Bravo, Marcos J

    2017-06-06

    Superenhancers are crucial structural genomic elements determining cell fate, and they are also involved in the determination of several diseases, such as cancer or neurodegeneration. Although there are pipelines which use independent pieces of software to predict the presence of superenhancers from genome-wide chromatin marks or DNA-interaction protein binding sites, there is not yet an integrated software tool that processes automatically algebra combinations of raw data sequencing into a comprehensive final annotated report of predicted superenhancers. We have developed NaviSE, a user-friendly streamlined tool which performs a fully-automated parallel processing of genome-wide epigenomics data from sequencing files into a final report, built with a comprehensive set of annotated files that are navigated through a graphic user interface dynamically generated by NaviSE. NaviSE also implements an 'epigenomics signal algebra' that allows the combination of multiple activation and repression epigenomics signals. NaviSE provides an interactive chromosomal landscaping of the locations of superenhancers, which can be navigated to obtain annotated information about superenhancer signal profile, associated genes, gene ontology enrichment analysis, motifs of transcription factor binding sites enriched in superenhancers, graphs of the metrics evaluating the superenhancers quality, protein-protein interaction networks and enriched metabolic pathways among other features. We have parallelised the most time-consuming tasks achieving a reduction up to 30% for a 15 CPUs machine. We have optimized the default parameters of NaviSE to facilitate its use. NaviSE allows different entry levels of data processing, from sra-fastq files to bed files; and unifies the processing of multiple replicates. NaviSE outperforms the more time-consuming processes required in a non-integrated pipeline. Alongside its high performance, NaviSE is able to provide biological insights, predicting cell

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

    Science.gov (United States)

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

    2017-05-01

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

  18. Liquidus Projection and Isothermal Section of the Sb-Se-Sn System

    Science.gov (United States)

    Chang, Jui-shen; Chen, Sinn-wen

    2017-12-01

    Sb-Se-Sn ternary alloys are promising chalcogenide materials. The liquidus projection and 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system are determined. Numerous Sb-Se-Sn alloys are prepared, and their primary solidification phases are examined. In addition to the three terminal phases, (Sb), (Se) and (Sn), there are Sb2Sn3, SbSn, SnSe, SnSe2, Sb2Se3, Sn2Sb9Se9, and SnSb2Se4 phases. In addition, there are two miscibility gaps along the Sb-Se and Se-Sn and sides. There are ten invariant reactions in the Sb-Se-Sn ternary system, and seven of them are experimentally determined in this study. The lowest reaction temperature of determined invariant reaction is L + SbSn = (Sn) + SnSe at 515.4 K ± 5 K (242.2 °C ± 5 °C). There are nine tie-triangles, which are Liquid + SbSn + SnSe, SbSn + SnSe + (Sb), SnSe + (Sb) + Sn2Sb9Se9, (Sb) + Sb2Se3 + Sn2Sb9Se9, SnSe + Sn2Sb9Se9 + SnSb2Se4, Sb2Se3 + Sn2Sb9Se9 + SnSb2Se4, SnSe + SnSe2 + SnSb2Se4, SnSe2 + SnSb2Se4 + Sb2Se3, and SnSe2 + Sb2Se3 + Liquid in the 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system.

  19. Banks offer SE more than it asked for

    International Nuclear Information System (INIS)

    Janoska, J.

    2004-01-01

    About a year ago, when new management took over the financial department of Slovenske elektrarne (SE), a.s. the company was in crisis. It faced an acute cash-flow deficit and due loans of over 20 bill. Sk (501.21 mil. Eur). SE could not provide adequate guarantees for the required loans and without state guarantees it was virtually impossible or too expensive to obtain additional loans. But last week the situation changed for the better. Despite the fact that due to the restructuring of SE's loan portfolio, the company will pay the banks 3 bill. Sk (75.18 mil. Eur) less interest over the next three years than under the original arrangements, even the bakers seemed satisfied. A loan portfolio full of non-standard agreements signed with about 30 banks had previously prevented decisions regarding the structure of the company's assets and liabilities.The cabinet refused to admit that SE was in crisis and offered SE for sale, although it could not be privatised due to its debt structure and the fact that it was close to default. Despite this unfavourable situation, company economists decided to make an offensive move -in cooperation with a small group of banks they converted the tens of company loan agreements into a new loan package that will be simpler, cheaper, and with longer maturity periods, which will not require state guarantees. SE managed to restructure debts with a total value of 550 mil. Eur and until these transactions are completed the banks offered SE a bridge loan of 110 mil. Eur. The transaction related to a syndicated loan of 350 mil. Eur which was concluded in April. Eurobonds with a total value of 200 mil. Eur were issued two months later. The banks offered the company more than it requested. Demand for the Eurobond issue exceeded the 200 mil. Eur of bonds on offer. (author)

  20. Distopie voor oë: Eben Venter se duister kuns

    Directory of Open Access Journals (Sweden)

    Harry Sewlall

    2016-08-01

    Full Text Available Sedert die verskyning van Joseph Conrad se novelle, Heart of Darkness, uitgegee as vervolgverhaal in 1899, was daar al verskeie pogings om Conrad se teks te ‘herskryf’, al was die verwantskap met die meesterteks dikwels gering of selfs twyfelagtig. Nog ’n herskrywing van Conrad se teks is Eben Venter se roman Trencherman, aanvanklik in Afrikaans uitgegee as Horrelpoot. Hierdie teks volg die meesterteks baie nougeset na, nie slegs deur aanhalings daaruit as motto’s vooraan elke hoofstuk te gebruik nie, maar ook deur beelde en woorde uit die oorspronklike teks op ooglopende of bedekte wyse in die narratief in te weef. Die vrae waarmee ’n leser soos ek, wat nie vertroud is met Afrikaans nie, gekonfronteer word, is of dit ’n geval van plagiaat is of ’n oefening in intertekstualiteit en ofdie boek eerder ’n poging is om sensasie te wek ten einde meer boeke te verkoop. Hierdie vraevorm die basis vir ’n intertekstuele verkenning van die twee tekste, wat neerkom op ’n stiplees van Conrad se teks langs Trencherman ten einde die intertekstuele skakels tussen die twee tekste te identifiseer. Teoreties is die artikel gebaseer op die werk van Kristeva en Barthes. Die ondersoek het bevestig dat Trencherman inderdaad ’n oefening in intertekstualiteit is, nie slegs as intertekstualiteit nie, maar eerder as ’n in-gesprek-tree met Conrad se meesterteks. Daaruit volg die slotsom dat Trencherman ’n geldige intertekstuele antwoord is op Heart of darkness wat Conrad se beroemde novelle dekonstrueer en die draaiboek daarvan transponeer na ’n distopiese, post-demokratiese Suid-Afrika.

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

    Directory of Open Access Journals (Sweden)

    Aeshah Salem

    2016-09-01

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

  2. ¿Qué tienes en la cara, eso se quita?

    Directory of Open Access Journals (Sweden)

    Jimmy Arévalo Romero

    2013-10-01

    Full Text Available El presente texto es un ensayo preparado por estudiantes de Medicina que tiene origen en su experiencia personal, ya que trata del padecimiento del acné en lo adolescencia, en él quieren concienciar a lo comunidad en general sobre las consecuencias psicológicas que genera el padecimiento del acné en el adolescente, y estimular a las personas a contribuir al desarrollo de estos jóvenes en la sociedad.

  3. After four months new privatisation committee in SE

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

    In spite of a delay the Minister of Economy of the Slovak Republic wants to meet the schedule set by Government. In middle of September 2002 six prospect submitted their tender offers for entering Slovenske elektrarne (SE), a.s, Bratislava. Representative of privatisation advisor of SE, PricewaterhouseCoopers, Peter Mitka told TREND that he was in contact with the investors but they were waiting for a signal from official authorities about the current state of the tender. And they have been waiting for four months. Only last week a new privatisation commission started dealing with the offers. In spite of these facts Minister of Economy, Robert Nemcsics does not consider the process slow and said that the Ministry would use all its efforts to adhere to the original privatisation schedule prepared by the former government. He further added that everything would depend on the offers submitted. Investors are not interest in SE as a whole but only in its parts. Several members of the committee do not agree with the privatisation and restructuring principles set by the government including a split of SE to conventional and nuclear parts. One of the opponents is the former manager of SE Tibor Mikus (HZDS) - representative of the Parliament or Vladimir Mojs representative of Slovak Energeticists Unions. This put a brake on the tender and changes in the management of SE as well. Privatisation Agency FNM still has not decided upon calling a Extraordinary General Meeting of SE that would elect new bodies. Spokeswoman of FNM, Tatjana Lesajova claims that the Fund is still missing a legal analysis that would review the possibility of changing SE's Articles of Association so that the Board of Directors could be assigned based on a tender (proposal of the Ministry). Members of SE Privatisation Committee: Eva Simkova - Secretary of State, Ministry of Economy SR; Laszlo Pomothy - Secretary of State, Ministry of Economy SR; Henrich Herceg - Advisor to the Minister of Economy SR

  4. ¿Y, cómo se hacen?

    Directory of Open Access Journals (Sweden)

    Juan Ruiz

    2015-01-01

    Full Text Available El mundo de los dibujos animados es producto de la imaginación, de la fantasía que vuela en los sueños de los hombres de cualquier edad. El artículo relata la forma en cómo estos simpáticos personajes, que vemos a diario en el cine o la televisión, pueden moverse tan libremente y con tanto desenfado. Se parte de la idea o argumento, el guionista narra la historia de lo que será el animado. Luego el director con un dibujante trazan las escenas principales de la historia (storyboard o guión dibujado se discute con los artistas y realizadores del filme; una vez aprobado este se perfila el diseño de los personajes, se realiza la escenografía (maquetas de ser necesario. Se hacen los parlamentos o diálogos de los personajes para que actores(as pongan las voces y sigue el proceso más fino y técnico.

  5. Transition probabilities in neutron-rich Se,8684

    Science.gov (United States)

    Litzinger, J.; Blazhev, A.; Dewald, A.; Didierjean, F.; Duchêne, G.; Fransen, C.; Lozeva, R.; Sieja, K.; Verney, D.; de Angelis, G.; Bazzacco, D.; Birkenbach, B.; Bottoni, S.; Bracco, A.; Braunroth, T.; Cederwall, B.; Corradi, L.; Crespi, F. C. L.; Désesquelles, P.; Eberth, J.; Ellinger, E.; Farnea, E.; Fioretto, E.; Gernhäuser, R.; Goasduff, A.; Görgen, A.; Gottardo, A.; Grebosz, J.; Hackstein, M.; Hess, H.; Ibrahim, F.; Jolie, J.; Jungclaus, A.; Kolos, K.; Korten, W.; Leoni, S.; Lunardi, S.; Maj, A.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatovic, T.; Million, B.; Möller, O.; Modamio, V.; Montagnoli, G.; Montanari, D.; Morales, A. I.; Napoli, D. R.; Niikura, M.; Pollarolo, G.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Sahin, E.; Salsac, M. D.; Scarlassara, F.; Söderström, P.-A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Theisen, Ch.; Valiente Dobón, J. J.; Vandone, V.; Vogt, A.

    2015-12-01

    Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich Se,8684 are investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was performed at the Istituto Nazionale di Fisica Nucleare (INFN) Laboratori Nazionali di Legnaro using the Cologne Plunger device for the RDDS technique and the AGATA Demonstrator array for the γ -ray detection coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 86Se the level lifetime of the yrast 21+ state and an upper limit for the lifetime of the 41+ state are determined for the first time. The results of 86Se are in agreement with previously reported predictions of large-scale shell-model calculations using Ni78-I and Ni78-II effective interactions. In addition, intrinsic shape parameters of lowest yrast states in 86Se are calculated. In semimagic 84Se level lifetimes of the yrast 41+ and 61+ states are determined for the first time. Large-scale shell-model calculations using effective interactions Ni78-II, JUN45, jj4b, and jj4pna are performed. The calculations describe B (E 2 ;21+→01+) and B (E 2 ;61+→41+) fairly well and point out problems in reproducing the experimental B (E 2 ;41+→21+) .

  6. Electroluminescence of colloidal ZnSe quantum dots

    International Nuclear Information System (INIS)

    Dey, S.C.; Nath, S.S.

    2011-01-01

    The article reports a green chemical synthesis of colloidal ZnSe quantum dots at a moderate temperature. The prepared colloid sample is characterised by UV-vis absorption spectroscopy and transmission electron microscopy. UV-vis spectroscopy reveals as-expected blue-shift with strong absorption edge at 400 nm and micrographs show a non-uniform size distribution of ZnSe quantum dots in the range 1-4 nm. Further, photoluminescence and electroluminescence spectroscopies are carried out to study optical emission. Each of the spectroscopies reveals two emission peaks, indicating band-to-band transition and defect related transition. From the luminescence studies, it can be inferred that the recombination of electrons and holes resulting from interband transition causes violet emission and the recombination of a photon generated hole with a charged state of Zn-vacancy gives blue emission. Meanwhile electroluminescence study suggests the application of ZnSe quantum dots as an efficient light emitting device with the advantage of colour tuning (violet-blue-violet). - Highlights: → Synthesis of ZnSe quantum dots by a green chemical route. → Characterisation: UV-vis absorption spectroscopy and transmission electron microscopy. → Analysis of UV-vis absorption spectrum and transmission electron micrographs. → Study of electro-optical properties by photoluminescence and electroluminescence. → Conclusion: ZnSe quantum dots can be used as LED with dual colour emission.

  7. Optical studies of CdSe/PVA nanocomposite films

    Science.gov (United States)

    Kushwaha, Kamal Kumar; Ramrakhaini, Meera

    2018-05-01

    The nanocomposite films of CdSe nanocrystals in polyvinyl alcohol (PVA) matrix were synthesized by environmental friendly chemical method. These composites were characterized by X-ray diffraction which indicates the hexagonal crystalline structure of CdSe with crystal size up to a few nm. The crystal size is found to decrease by increasing PVA Concentration. The photoluminescence (PL) characteristics of these composite films with varying concentration of PVA as well as Cd2+ content have been investigated. The PL peak of CdSe was observed at 510 nm and higher intensity is observed by increasing PVA concentration without any change in position of PL peak. Due to proper passivation of surface states non-radiative transition are reduced which enhance the PL intensity. By increasing concentration of Cd2+ content in the CdSe/PVA nanocomposite films, smaller CdSe nanocrystals were obtained giving higher intensity and blue shift in the PL peak due to enhanced oscillator strength and quantum confinement effect. The PL peak in green and blue region makes these composite films promising materials for optical display devices. The Refractive index of these composites was also measured at sodium line with the help of Abee's refractometer and was found in the range of 2.20-2.45. It is seen that refractive index varies with polymer concentration. This may be useful for their potential application in anti-reflection coating, display devices and optical sensors.

  8. Diffusion behavior for Se and Zr in sodium-bentonite

    International Nuclear Information System (INIS)

    Sato, Haruo; Yui, Mikazu; Yoshikawa, Hideki

    1995-01-01

    Apparent diffusion coefficients for Se and Zr in bentonite were measured by in-diffusion method at room temperature using water-saturated sodium-bentonite, Kunigel V1 reg-sign containing 50wt% Na-smectite as a major mineral was used as the bentonite material. The experiments were carried out in the dry density range of 400--1,800 kg/m 3 . Bentonite samples were immersed with distilled water and saturated before the experiments. The experiments for Se were carried out under N 2 atmospheric condition (O 2 : 2.5ppm). Those for Zr were carried out under aerobic condition. The apparent diffusion coefficients decrease with increasing density of the bentonite. Since dominant species of Se in the pore water is predicted to be SeO 3 2- , Se may be retarded by anion-exclusion because of negative charge on the surface of the bentonite and little sorption. The dominant species of Zr in the porewater is predicted to be Zr(OH) 5 - or HZrO 3 - . Distribution coefficient measured for Zr on the bentonite was about 1.0 m 3 /kg from batch experiments. Therefore, the retardation may be caused by combination of the sorption and the anion-exclusion. A modeling for the diffusion mechanisms in the bentonite were discussed based on an electric double layer theory. Comparison between the apparent diffusion coefficients predicted by the model and the measured ones shows a good agreement

  9. Quasi-two-dimensional thermoelectricity in SnSe

    Science.gov (United States)

    Tayari, V.; Senkovskiy, B. V.; Rybkovskiy, D.; Ehlen, N.; Fedorov, A.; Chen, C.-Y.; Avila, J.; Asensio, M.; Perucchi, A.; di Pietro, P.; Yashina, L.; Fakih, I.; Hemsworth, N.; Petrescu, M.; Gervais, G.; Grüneis, A.; Szkopek, T.

    2018-01-01

    Stannous selenide is a layered semiconductor that is a polar analog of black phosphorus and of great interest as a thermoelectric material. Unusually, hole doped SnSe supports a large Seebeck coefficient at high conductivity, which has not been explained to date. Angle-resolved photoemission spectroscopy, optical reflection spectroscopy, and magnetotransport measurements reveal a multiple-valley valence-band structure and a quasi-two-dimensional dispersion, realizing a Hicks-Dresselhaus thermoelectric contributing to the high Seebeck coefficient at high carrier density. We further demonstrate that the hole accumulation layer in exfoliated SnSe transistors exhibits a field effect mobility of up to 250 cm2/V s at T =1.3 K . SnSe is thus found to be a high-quality quasi-two-dimensional semiconductor ideal for thermoelectric applications.

  10. Self-Assembled PbSe Nanowire:Perovskite Hybrids

    KAUST Repository

    Yang, Zhenyu

    2015-12-02

    © 2015 American Chemical Society. Inorganic semiconductor nanowires are of interest in nano- and microscale photonic and electronic applications. Here we report the formation of PbSe nanowires based on directional quantum dot alignment and fusion regulated by hybrid organic-inorganic perovskite surface ligands. All material synthesis is carried out at mild temperatures. Passivation of PbSe quantum dots was achieved via a new perovskite ligand exchange. Subsequent in situ ammonium/amine substitution by butylamine enables quantum dots to be capped by butylammonium lead iodide, and this further drives the formation of a PbSe nanowire superlattice in a two-dimensional (2D) perovskite matrix. The average spacing between two adjacent nanowires agrees well with the thickness of single atomic layer of 2D perovskite, consistent with the formation of a new self-assembled semiconductor nanowire:perovskite heterocrystal hybrid.

  11. Some kinetic properties of DySnSe2 combination

    International Nuclear Information System (INIS)

    Murguzov, M.I.; Mammadova, E.R.

    2008-01-01

    Recently, to the acquisition of multi-component alloys and combination in the presence of rare-earth metals (REM) interest has grown considerably. According to preliminary data, in the presence of rare-earth metals you can obtain perspective semiconductor materials which are of practical importance, and can be used in various fields of microelectronics in a complex system of chalcogenides. DySnSe 2 combination is also includes to this system. Physical peculiarities of these combinations have been studied in wide interval. DySnSe 2 combination crystallizes in ortho rhombic crystal system and is an indemnification n-type semiconductor material. The mechanism of electrical conductivity in DySnSe 2 semiconductor combination is complicated and cargo carrier scattering changes at low temperatures. That is why, the mixed type conductivity occurs

  12. Concentrations of Se, Ba, Zn and Mn in Brazil nuts

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cozollino, Silvia M.F., E-mail: marmelin@ipen.br, E-mail: vmaihara@ipen.br, E-mail: msaiki@ipen.br, E-mail: pscsilva@ipen.br, E-mail: smfcozzo@usp.br [Universidade de São Paulo (USP), SP (Brazil). Faculdade de Ciências Farmacêuticas

    2017-07-01

    The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

  13. PySE: Python Source Extractor for radio astronomical images

    Science.gov (United States)

    Spreeuw, Hanno; Swinbank, John; Molenaar, Gijs; Staley, Tim; Rol, Evert; Sanders, John; Scheers, Bart; Kuiack, Mark

    2018-05-01

    PySE finds and measures sources in radio telescope images. It is run with several options, such as the detection threshold (a multiple of the local noise), grid size, and the forced clean beam fit, followed by a list of input image files in standard FITS or CASA format. From these, PySe provides a list of found sources; information such as the calculated background image, source list in different formats (e.g. text, region files importable in DS9), and other data may be saved. PySe can be integrated into a pipeline; it was originally written as part of the LOFAR Transient Detection Pipeline (TraP, ascl:1412.011).

  14. Linkages between Icelandic Low position and SE Greenland winter precipitation

    Science.gov (United States)

    Berdahl, M.; Rennermalm, A. K.; Hammann, A. C.; Mioduszewski, J.; Hameed, S.; Tedesco, M.; Stroeve, J. C.; Mote, T. L.

    2015-12-01

    Greenland's largest flux of precipitation occurs in its Southeast (SE) region. An understanding of the mechanisms controlling precipitation in this region is lacking despite its disproportionate importance in the mass balance of Greenland and the consequent contributions to sea level rise. We use weather station data from the Danish Meteorological Institute to reveal the governing influences on precipitation in SE Greenland during the winter and fall. We find that precipitation in the fall is significantly correlated to the longitude of the Icelandic Low and the NAO. Winter precipitation is correlated with the strength and longitude of the Icelandic Low, as well as the NAO. We show that in years of extreme high precipitation, onshore winds dominate, thereby advecting more moisture inland. In low precipitation years, winds are more westerly, approaching the stations from land. Understanding the controls of SE Greenland precipitation will help us predict how future precipitation in this key region may change in a warming climate.

  15. SE and ENEL - One Year Together One Year after Privatization

    International Nuclear Information System (INIS)

    Anon

    2007-01-01

    In Bratislava, one year ago, exactly in April 28, the privatization deal of a 66% stake in Slovenske elektrarne (SE) was finally closed. The Slovak government and the Italian company ENEL signed final documents and ENEL thus definitely entered into SE. In May 2006, Miroslav Pikus, a former CEO, was replaced by Marco Arcelli, who, as a regional manager for Slovakia, had been preparing the entry of ENEL into SE since March 2005. Not only did he sometimes cook for us, in his 'kitchen' but also there were prepared 160 investment projects, e.g the improvement of nuclear safety and resistance of the Bohunice power plant, electricity sale through the so-called 'virtual power plant', ensuring a non-attended operation in hydro power plants, reconstruction and modernization of the Orava and Dobsina hydro power plants. (author)

  16. Teoria feminista: o desafio de tornar-se um paradigma

    Directory of Open Access Journals (Sweden)

    Mirian Santos Paiva

    1997-12-01

    Full Text Available Partindo da crise do paradigma tradicional e tendo como epicentro a crítica feminista, este trabalho tenta mostrar o desafio que enfrenta a teoria feminista para tornar-se um novo paradigma e para tanto realiza-se uma pesquisa bibliográfica, consubstanciada na literatura pertinente ao tema. Evidencia-se que o desafio de ser um paradigma em ascensão faz com que esta teoria enfrente problemas teóricos, conceituais e metodológicos que precisam de um esforço conjunto para serem aprofundados e resolvidos. Todavia, o desenvolvimento desta teoria não depende apenas do mundo acadêmico, mas está também atrelado a mudanças na estrutura social, pois, de uma sociedade mais igualitária, mais facilmente emergirá um conhecimento sem dominação de gênero.

  17. Concentrations of Se, Ba, Zn and Mn in Brazil nuts

    International Nuclear Information System (INIS)

    Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko; Cozollino, Silvia M.F.

    2017-01-01

    The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

  18. Optics of colloidal quantum-confined CdSe nanoscrolls

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, R B; Sokolikova, M S [M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Vitukhnovskii, A G; Ambrozevich, S A; Selyukov, A S; Lebedev, V S [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-09-30

    Nanostructures in the form of 1.2-nm-thick colloidal CdSe nanoplatelets rolled into scrolls are investigated. The morphology of these scrolls is analysed and their basic geometric parameters are determined (diameter 29 nm, longitudinal size 100 – 150 nm) by TEM microscopy. Absorption and photoluminescence spectra of these objects are recorded, and the luminescence decay kinetics is studied. It is shown that the optical properties of CdSe nanoscrolls differ significantly from the properties of CdSe quantum dots and that these nanoscrolls are attractive for nanophotonic devices due to large oscillator strengths of the transition, small widths of excitonic peaks and short luminescence decay times. Nanoscrolls can be used to design hybrid organic–inorganic pure-color LEDs with a high luminescence quantum yield and low operating voltages. (optics and technology of nanostructures)

  19. Self-Assembled PbSe Nanowire:Perovskite Hybrids

    KAUST Repository

    Yang, Zhenyu; Yassitepe, Emre; Voznyy, Oleksandr; Janmohamed, Alyf; Lan, Xinzheng; Levina, Larissa; Comin, Riccardo; Sargent, Edward H.

    2015-01-01

    © 2015 American Chemical Society. Inorganic semiconductor nanowires are of interest in nano- and microscale photonic and electronic applications. Here we report the formation of PbSe nanowires based on directional quantum dot alignment and fusion regulated by hybrid organic-inorganic perovskite surface ligands. All material synthesis is carried out at mild temperatures. Passivation of PbSe quantum dots was achieved via a new perovskite ligand exchange. Subsequent in situ ammonium/amine substitution by butylamine enables quantum dots to be capped by butylammonium lead iodide, and this further drives the formation of a PbSe nanowire superlattice in a two-dimensional (2D) perovskite matrix. The average spacing between two adjacent nanowires agrees well with the thickness of single atomic layer of 2D perovskite, consistent with the formation of a new self-assembled semiconductor nanowire:perovskite heterocrystal hybrid.

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

    International Nuclear Information System (INIS)

    Herzinger, Michael

    2013-01-01

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

  1. Enhanced field emission behavior of layered MoSe2

    International Nuclear Information System (INIS)

    Suryawanshi, Sachin R; Pawbake, Amit S; Jadkar, Sandesh R; More, Mahendra A; Pawar, Mahendra S; Late, Dattatray J

    2016-01-01

    Herein, we report one step facile chemical vapor deposition method for synthesis of single-layer MoSe 2 nanosheets with average lateral dimension ∼60 μm on 300 nm SiO 2 /Si and n-type silicon substrates and field emission investigation of MoSe 2 /Si at the base pressure of ∼1 × 10 −8 mbar. The morphological and structural analyses of the as-deposited single-layer MoSe 2 nanosheets were carried out using an optical microscopy, Raman spectroscopy and atomic force microscopy. Furthermore, the values of turn-on and threshold fields required to extract an emission current densities of 1 and 10 μA cm −2 , are found to be ∼1.9 and ∼2.3 V μm −1 , respectively. Interestingly, the MoSe 2 nanosheet emitter delivers maximum field emission current density of ∼1.5 mA cm −2 at a relatively lower applied electric field of ∼3.9 V μm −1 . The long term operational current stability recorded at the preset values of 35 μA over 3 hr duration and is found to be very good. The observed results demonstrates that the layered MoSe 2 nanosheet based field emitter can open up many opportunities for their potential application as an electron source in flat panel display, transmission electron microscope, and x-ray generation. Thus, the facile one step synthesis approach and robust nature of single-layer MoSe 2 nanosheets emitter can provide prospects for the future development of practical electron sources. (paper)

  2. An x-ray study of InSe

    International Nuclear Information System (INIS)

    Nagpal, K.C.; Ali, Z.

    1975-01-01

    Complete X-ray powder pattern of InSe, so far not available to literature, has been analyzed. The layer structure is based on a rhombohedral lattice cell, with space group R 3m, a sub(o) = 4.0046 +- 0.0005 A, csub(o) = 25.960 +- 0.004 A, and atomic position in 3 (a) of the space group : Zsub(In) = +-0.0555, Zsub(se) = 2/3 +- 0.106. Extreme softness and initial observe-reverse orientation of the rhombohedral cell in adjacent parts of a crystal or in thin lamellae parallel to the basal cleavage planes appear to be the main factors responsible for the characteristic sets of sharp and diffuse lines in the powder patterns normally obtained. These and Gandolfi camera powder patterns for several crystals are given. Heat treatment of powders obtained through cold work has indicated that comparatively short duration of 'annealing' at 600 deg C improves the powder pattern to some extent, but longer periods give products consisting of other phases of the In-Se system with small amount of InSe. The relative proportion of free space over the InSe powders in capsules as well as the amount of cold work seem to be the two main factors affecting the decomposition of InSe and appearance of other phases. Large platy crystals, on the other hand, withstand the heat treatment for a longer time. Even they undergo drastic changes in the sructure on prolonged heating at 600 deg C, yielding hexagonal phases with a common csub(o) = 19.26 A and a sub(o) = 4.0 and 7.11 respectively. (author)

  3. Photoluminescence properties of boron doped InSe single crystals

    International Nuclear Information System (INIS)

    Ertap, H.; Bacıoğlu, A.; Karabulut, M.

    2015-01-01

    Undoped and boron doped InSe single crystals were grown by Bridgman–Stockbarger technique. The PL properties of undoped, 0.1% and 0.5% boron doped InSe single crystals have been investigated at different temperatures. PL measurements revealed four emission bands labeled as A, B, C and D in all the single crystals studied. These emission bands were associated with the radiative recombination of direct free excitons (n=1), impurity-band transitions, donor–acceptor recombinations and structural defect related band (impurity atoms, defects, defect complexes, impurity-vacancy complex etc.), respectively. The direct free exciton (A) bands of undoped, 0.1% and 0.5% boron doped InSe single crystals were observed at 1.337 eV, 1.335 eV and 1.330 eV in the PL spectra measured at 12 K, respectively. Energy positions and PL intensities of the emission bands varied with boron addition. The FWHM of direct free exciton band increases while the FWHM of the D emission band decreases with boron doping. Band gap energies of undoped and boron doped InSe single crystals were calculated from the PL measurements. It was found that the band gap energies of InSe single crystals decreased with increasing boron content. - Highlights: • PL spectra of InSe crystals have been studied as a function of temperature. • Four emission bands were observed in the PL spectra at low temperatures. • PL intensity and position of free exciton band vary with doping and temperature. • Temperature dependences of the bands observed in the PL spectra were analyzed

  4. Det stedløse fællesskab

    DEFF Research Database (Denmark)

    Andreasen, Torsten Arni Caleb

    2009-01-01

    Det værkløse, det uvedgåelige, det kommende fællesskab. I nr. 4 af tidsskriftet Aléa (1983) udkom første udgave af den franske filosof Jean-Luc Nancys artikel "La communauté désœuvrée" (Det værkløse fællesskab), der senere udkom med tilføjelser i bogen af samme navn (1986). Via en analyse af...

  5. HgSe(Te)-HgHal2 systems

    International Nuclear Information System (INIS)

    Pan'ko, V.V.; Khudolij, V.A.; Voroshilov, Yu.V.

    1989-01-01

    Using the methods of differential thermal and X-ray phase analyses the character of chemical interaction in the systems HgTe(Se)-HgHal 2 , where Hal is Cl, Br, I, is investigated. Formation of compounds Hg 3 Se 2 Hal 2 , Hg 3 Te 2 Hal 2 , Hg 3 TeCl 4 and Hg 3 TeBr 4 in these systems is established. The phase diagrams of the studied systems are presented. The parameters of elementary cells of the compounds with the unknown structure, as well as their unknown physicochemical properties, are determined

  6. Transcriptor de Lenguaje de Señas a Texto

    OpenAIRE

    Escalante Crespo, Perla Artemisa

    2006-01-01

    Este proyecto tiene como nombre "Transcriptor de Lenguaje de Señas a Texto" y tiene una orientación al procesamiento digital de imágenes. Nótese la aclaración de ser un transcriptor en lugar de traductor, el término es bien empleado, ya que traductor se aplica al significado de las palabras de un idioma a otro, y este proyecto es un transcriptor del lenguaje español signado a español, de ahí la diferencia. La acción de este proyecto viene implícita en su nombre, preci...

  7. Differential diagnosis of scintigraphic brain centres by 75Se selenite

    International Nuclear Information System (INIS)

    Bestagno, M.; Garraffa, V.; Rembado, R.; Guerra, U.

    1975-01-01

    Since standard brain scintigraphy with sup(99m)Tc is not always adequate for a satisfactory differential diagnosis of the radioactive foci detected, the possibilities of 75 Se sodium selenite were investigated. It was observed that in centres due to a vascular lesion the selenite concentration is always low, rising steeply in neoplasmic foci. The 75 Se-selenite scintigraphic method is considered highly valid, complementing that of sup(99m)Tc when this latter is unsuitable for diagnosis of the nature of cerebral foci [fr

  8. Far-Infrared Absorption of PbSe Nanorods

    KAUST Repository

    Hyun, Byung-Ryool

    2011-07-13

    Measurements of the far-infrared absorption spectra of PbSe nanocrystals and nanorods are presented. As the aspect ratio of the nanorods increases, the Fröhlich sphere resonance splits into two peaks. We analyze this splitting with a classical electrostatic model, which is based on the dielectric function of bulk PbSe but without any free-carrier contribution. Good agreement between the measured and calculated spectra indicates that resonances in the local field factors underlie the measured spectra. © 2011 American Chemical Society.

  9. Use of [75Se]selenomethionine in immunoglobulin biosynthetic studies

    International Nuclear Information System (INIS)

    Gutman, G.A.; Warner, N.L.; Harris, A.W.; Bowles, A.

    1978-01-01

    The gamma-emitting amino acid analog, [ 75 Se] selenomethionine, has been used as a biosynthetic label for immunoglobulins secreted by plasmacytomas in tissue culture. The secreted products are structurally intact with respect to their antibody combining sites and their class and allotype antigenic specificities. A component of [ 75 Se] selenomethionine preparations was found to bind to fetal calf serum proteins, in a manner releasable by mercaptoethanol, but not by sodium dodecyl sulfate and urea. Methods for circumventing the problems caused by this binding are described. (Auth.)

  10. Preparation of SnSe thin films by encapsulated selenization

    International Nuclear Information System (INIS)

    Sabar D. Hutagalung; Samsudi Sakrani; Yussof Wahab

    1994-01-01

    Tin selenide thin films were prepared by encapsulated selenization. A stacked layer of evaporated Sn and Se films were annealed in a carbon block at temperatures 100 - 500 degree Celsius for 3 hours. X-ray analysis and SEM (Scanning electron) micrograph results showed that SnSe was initially formed at 150 degree Celsius with crystal size 30.0 nm and reached optimum formation at 200 daximum of 57.4 % yield of 5-decene. Other factors such as reaction temperatures, types of solvent and wt% of rhenium loadings influence the activity of the catalytic system

  11. Microscopic theory of cation exchange in CdSe nanocrystals.

    Science.gov (United States)

    Ott, Florian D; Spiegel, Leo L; Norris, David J; Erwin, Steven C

    2014-10-10

    Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We use density-functional theory and kinetic Monte Carlo simulations to develop a microscopic theory that explains structural, optical, and electronic changes observed experimentally in Ag-cation-exchanged CdSe nanocrystals. We find that Coulomb interactions, both between ionized impurities and with the polarized nanocrystal surface, play a key role in cation exchange. Our theory also resolves several experimental puzzles related to photoluminescence and electrical behavior in CdSe nanocrystals doped with Ag.

  12. Electric field gradient studies in SnSe

    Energy Technology Data Exchange (ETDEWEB)

    Pal, G. [IUC, DAE Facilities (India); Sebastian, K.C. [M.S. University, Physics Department (India); Chintalapudi, S.N. [IUC, DAE Facilities (India); Somayajulu, D.R.S. [M.S. University, Physics Department (India)

    1999-09-15

    The EFG in IV-VI compound semiconductor SnSe was studied using two hyperfine interaction techniques, namely, TDPAC and Moessbauer spectroscopy. The EFG in this material increases sharply up to 300 K and thereafter at higher temperatures it gets saturated. However, the conductivity increases steadily at all the temperatures. The conductivity curve has two slopes. The first portion is due to the population of shallow Cd acceptor levels. Thus, in SnSe also the variation of the EFG with temperature is complex, as in other medium-gap semiconductors.

  13. Electric field gradient studies in SnSe

    International Nuclear Information System (INIS)

    Pal, G.; Sebastian, K.C.; Chintalapudi, S.N.; Somayajulu, D.R.S.

    1999-01-01

    The EFG in IV-VI compound semiconductor SnSe was studied using two hyperfine interaction techniques, namely, TDPAC and Moessbauer spectroscopy. The EFG in this material increases sharply up to 300 K and thereafter at higher temperatures it gets saturated. However, the conductivity increases steadily at all the temperatures. The conductivity curve has two slopes. The first portion is due to the population of shallow Cd acceptor levels. Thus, in SnSe also the variation of the EFG with temperature is complex, as in other medium-gap semiconductors

  14. Positive magnetoresistance in Fe3Se4 nanowires

    Science.gov (United States)

    Li, D.; Jiang, J. J.; Liu, W.; Zhang, Z. D.

    2011-04-01

    We report the magnetotransport properties of Fe3Se4 nanowire arrays in anodic aluminum oxide (AAO) porous membrane. The temperature dependence of resistance of Fe3Se4 nanowires at a zero field shows thermal activated behavior below 295 K. The exponential relationship in resistance is consistent with the model of strong localization with variable-range hopping (VRH) for a finite one-dimensional wire. Resistance versus magnetic field curves below 100 K show small positive magnetoresistance (MR). The field dependencies of log[R(H)/R(0)] explain the positive MR as the effect of magnetic field on the VRH conduction.

  15. Capacitors on the basis of intercalate GaSe

    Directory of Open Access Journals (Sweden)

    Kovalyuk Z. D.

    2010-06-01

    Full Text Available The compound GaSe is obtained by the technique of intercalation of a GaSe single crystal in a melt of the ferroelectric salt KNO3. The x-ray analysis of its crystal structure has been carried out and dielectric frequency characteristics of samples has been measured. It is estab-lished, that accumulation of electric charges occurs in the examined examples in frequency area 100—1000 Hz. A sample of filter capacitor has been created on the basis of the re-ceived compounds.

  16. ¿Cómo se leen los números?

    OpenAIRE

    Pedro Macizo; Amparo Herrera

    2012-01-01

    En los modelos de procesamiento numérico se asume que para llegar a la información fonológica que nos permite nombrar un dígito arábigo como “3”, tenemos que acceder previamente a su significado (la cantidad 3). Esto no es necesario cuando leemos una palabra numérica como “tres”, pues podemos pronunciarla sin entender a qué cantidad se refiere. Pero nuestro equipo ha mostrado recientemente que tanto la denominación de dígitos arábigos como la lectura de palabras numéricas pueden realizarse si...

  17. g-factor of the ground state of 73Se

    International Nuclear Information System (INIS)

    Nishimura, Katsuhiko; Ohya, Susumu; Mutsuro, Naoshi

    1987-01-01

    Nuclear magnetic resonance on oriented 73 Se in an iron host has been observed at about 7mK. From resonance-shift measurement, the magnetic hyperfine-splitting frequency μ M , g-factor and magnetic hyperfine field were derived as μ M =102.61(3)MH z , |g(9/2 + )|=0.188(16) and B HF ( 73 SeFe)=716(81)kG. The experimental values of the g-factors of the g 9/2 neutron states, in the neighborhood of the neutron number 40, are compared with the theoretical values based on the core-polarization model. (author)

  18. Formation and properties of epitaxial CdSe, ZnSe quantum dots. Conventional molecular beam epitaxy and related techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, Suddhasatta

    2008-01-16

    This thesis systematically investigates three such alternative approaches, along with conventional MBE, with emphasis on the formation-mechanism of QDs, and optimization of their morphological and optical attributes. it is shown here that no distinct 3D islands are formed in MBE growth of CdSe on ZnSe. While CdSe heteroepitaxy occurs in the multilayer-mode at T{sub G}=300 C, a reentrant recovery of the layer-by-layer mode is reported in this thesis, for growth at T{sub G}<{proportional_to}240 C. In the second variant technique, formation of large and distinct islands is demonstrated by deposition of amorphous selenium (a-Se) onto a 2D CdSe epilayer at room temperature and its subsequent desorption at a higher temperature (T{sub D}=230 C). The process steps of the third variant technique, developed in course of this work, are very similar to those of the previous one-the only alteration being the substitution of selenium with tellurium as the cap-forming-material. (orig.)

  19. Exotic topological insulator states and topological phase transitions in Sb2Se3-Bi2Se3 heterostructures

    KAUST Repository

    Zhang, Qianfan

    2012-03-27

    Topological insulator is a new state of matter attracting tremendous interest due to its gapless linear dispersion and spin momentum locking topological states located near the surface. Heterostructures, which have traditionally been powerful in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb 2Se 3-Bi 2Se 3 heterostructures by first-principle simulation and discovered that an exotic topological state exists. Surprisingly, the state migrates from the nontrivial Bi 2Se 3 into the trivial Sb 2Se 3 region and spreads across the entire Sb 2Se 3 slab, extending beyond the concept of "surface" state while preserving all of the topological surface state characteristics. This unusual topological state arises from the coupling between different materials and the modification of electronic structure near Fermi energy. Our study demonstrates that heterostructures can open up opportunities for controlling the real-space distribution of the topological state and inducing quantum phase transitions between topologically trivial and nontrivial states. © 2012 American Chemical Society.

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

    Science.gov (United States)

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

    2009-03-01

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

  1. Investigation of CuGaSe2/CuInSe2 double heterojunction interfaces grown by molecular beam epitaxy

    Directory of Open Access Journals (Sweden)

    Sathiabama Thiru

    2015-02-01

    Full Text Available In-situ reflection high-energy electron diffraction (RHEED observation and X-ray diffraction measurements were performed on heterojunction interfaces of CuGaSe2/CnInSe2/CuGaSe2 grown on GaAs (001 using migration-enhanced epitaxy. The streaky RHEED pattern and persistent RHEED intensity oscillations caused by the alternate deposition of migration-enhanced epitaxy sequence are observed and the growths of smooth surfaces are confirmed. RHEED observation results also confirmed constituent material interdiffusion at the heterointerface. Cross-sectional transmission electron microscopy showed a flat and abrupt heterointerface when the substrate temperature is as low as 400 °C. These have been confirmed even by X-ray diffraction and photoluminescence measurements.

  2. Formation and properties of epitaxial CdSe, ZnSe quantum dots. Conventional molecular beam epitaxy and related techniques

    International Nuclear Information System (INIS)

    Mahapatra, Suddhasatta

    2008-01-01

    This thesis systematically investigates three such alternative approaches, along with conventional MBE, with emphasis on the formation-mechanism of QDs, and optimization of their morphological and optical attributes. it is shown here that no distinct 3D islands are formed in MBE growth of CdSe on ZnSe. While CdSe heteroepitaxy occurs in the multilayer-mode at T G =300 C, a reentrant recovery of the layer-by-layer mode is reported in this thesis, for growth at T G D =230 C). The process steps of the third variant technique, developed in course of this work, are very similar to those of the previous one-the only alteration being the substitution of selenium with tellurium as the cap-forming-material. (orig.)

  3. Mobility activation in thermally deposited CdSe thin films

    Indian Academy of Sciences (India)

    Effect of illumination on mobility has been studied from the photocurrent decay characteristics of thermally evaporated CdSe thin films deposited on suitably cleaned glass substrate held at elevated substrate temperatures. The study indicates that the mobilities of the carriers of different trap levels are activated due to the ...

  4. An effective pair potential for liquid semiconductor, Se: Structure and ...

    Indian Academy of Sciences (India)

    The effective pair potential of liquid semiconductor Se is extracted from its experimental structure factor data using an accurate liquid state theory and this shows important basic features. A model potential incorporating the basic features of the structure factor extracted potential is suggested. This model potential is then used ...

  5. Far-Infrared Absorption of PbSe Nanorods

    KAUST Repository

    Hyun, Byung-Ryool; Bartnik, A. C.; Koh, Weon-kyu; Agladze, N. I.; Wrubel, J. P.; Sievers, A. J.; Murray, Christopher B.; Wise, Frank W.

    2011-01-01

    Measurements of the far-infrared absorption spectra of PbSe nanocrystals and nanorods are presented. As the aspect ratio of the nanorods increases, the Fröhlich sphere resonance splits into two peaks. We analyze this splitting with a classical

  6. Giant Rashba spin splitting in Bi2Se3: Tl

    KAUST Repository

    Singh, Nirpendra; Saeed, Yasir; Schwingenschlö gl, Udo

    2014-01-01

    First-principles calculations are employed to demonstrate a giant Rashba spin splitting in Bi2Se3:Tl. Biaxial tensile and compressive strain is used to tune the splitting by modifying the potential gradient. The band gap is found to increase under

  7. Electrical conduction mechanism in GeSeSb chalcogenide glasses

    Indian Academy of Sciences (India)

    by melt quenching has been determined at different temperatures in bulk through the I–V characteristic curves ... DC conductivity; chalcogenide glass; Sb–Se bonding; Poole–Frenkel mechanism .... measurements were taken at room temperature as well as ele- .... age across the sample was continuued, the induced thermal.

  8. Introduction : A decade of experience with the SE

    NARCIS (Netherlands)

    Cremers, Jan; Cremers, Jan; Stollt, Michael; Vitols, Sigurt

    2013-01-01

    The first (introductory) chapter of this book describes the (legal) background, the definition of the European Company (SE) and the different articles of the legislation. The focus is on workers involvement and the relationship with national practices. It also summarizes the different contributions.

  9. Pollen of Syzygium (Myrtaceae) from SE Asia, especially Thailand

    NARCIS (Netherlands)

    Parnell, J.

    2003-01-01

    Pollen of 57 species of Syzygium from SE Asia were surveyed by SEM. The grains are all ± triangular in polar view, uniformly small (mean diameter 10.4 μm) with few surface sculpturing features. All species examined exhibit a distinct apocolpium and, usually, apocolpial field. The presence of an

  10. Locoh, Thérèse - AJOL

    African Journals Online (AJOL)

    Locoh, Thérèse. Vol 10, No 3 (1999) - Articles Early Marriage and Motherhood in Sub-Saharan Africa Abstract. ISSN: 0850-8518. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

  11. Sample (S): SE40_S24 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE40_S24 Solanum lycopersicum Kyotemari fruit Solanum lycopersicum NCBI taxonomy:40...81 Solanum lycopersicum Kyotemari fruit are grown in greenhouses of the Experimental Farm of Kyoto University (Takatsuki, Osaka, Japan) from winter 2013 to spring 2014. ...

  12. P. S. D DIE TEOLOGIESE HOOFGEDAGTES IN KIERKEGAARD SE ...

    African Journals Online (AJOL)

    Test

    D.Phil. DIE TEOLOGIESE HOOFGEDAGTES IN KIERKEGAARD SE. STRYD TEEN DIE HEGELSE SISTEEM. A. INLEIDENDE OPMERKING. Ons is van oordeel dat dit ongetwyfeld paslik is om in ons waardering van die persoon en werk van prof. H. P. Wolmarans, oor die Deense denker en digter, Kierkegaard, te skrywe.

  13. Vody i lesy Šumavy se zotavují

    Czech Academy of Sciences Publication Activity Database

    Kopáček, Jiří

    2018-01-01

    Roč. 97, č. 1 (2018), s. 52-54 ISSN 0042-4544 Institutional support: RVO:60077344 Keywords : bark beetle infestation * soil * water * atmospheric deposition Subject RIV: DJ - Water Pollution ; Quality https://vesmir.cz/cz/casopis/archiv-casopisu/2018/cislo-1/vody-lesy-sumavy-se-zotavuji.html

  14. Space charge limited conduction in CdSe thin films

    Indian Academy of Sciences (India)

    Unknown

    of trap limited space charge limited conduction (SCLC) at higher voltage. The transition voltage (Vt ) from ohmic to SCLC is found to be quite independent of ambient temperature as well as intensity of illumination. SCLC is explained on the basis of the exponential trap distribution in CdSe films. Trap depths estimated from.

  15. Strain tuning of optical properties in Bi2Se3

    DEFF Research Database (Denmark)

    Jensen, Mathias Rosdahl; Mørk, Jesper; Willatzen, Morten

    2017-01-01

    Based on symmetry principles we determine the most general Hamiltonian for the low energy physics of Bi2Se3, including contributions due to a static electric field and strain. The full three-dimensional model is projected into the surface states at k= 0, giving an effective two-dimensional Hamilt...

  16. Nonlinear optical characteristics of monolayer MoSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Le, Chinh Tam; Ullah, Farman; Senthilkumar, Velusamy; Kim, Yong Soo [Department of Physics and Energy Harvest Storage Research Center, University of Ulsan (Korea, Republic of); Clark, Daniel J.; Jang, Joon I. [Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY (United States); Sim, Yumin; Seong, Maeng-Je [Department of Physics, Chung-Ang University, Seoul (Korea, Republic of); Chung, Koo-Hyun [School of Mechanical Engineering, University of Ulsan (Korea, Republic of); Park, Hyoyeol [Electronics, Communication and Semiconductor Applications Department, Ulsan College (Korea, Republic of)

    2016-08-15

    In this study, we utilized picosecond pulses from an Nd:YAG laser to investigate the nonlinear optical characteristics of monolayer MoSe{sub 2}. Two-step growth involving the selenization of pulsed-laser-deposited MoO{sub 3} film was employed to yield the MoSe{sub 2} monolayer on a SiO{sub 2}/Si substrate. Raman scattering, photoluminescence (PL) spectroscopy, and atomic force microscopy verified the high optical quality of the monolayer. The second-order susceptibility χ{sup (2)} was calculated to be ∝50 pm V{sup -1} at the second harmonic wavelength λ{sub SHG} ∝810 nm, which is near the optical gap of the monolayer. Interestingly, our wavelength-dependent second harmonic scan can identify the bound excitonic states including negatively charged excitons much more efficiently, compared with the PL method at room temperature. Additionally, the MoSe{sub 2} monolayer exhibits a strong laser-induced damage threshold ∝16 GW cm{sup -2} under picosecond-pulse excitation{sub .} Our findings suggest that monolayer MoSe{sub 2} can be considered as a promising candidate for high-power, thin-film-based nonlinear optical devices and applications. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. The Crystal Structure of Cu4Bi4Se9

    DEFF Research Database (Denmark)

    Makovicky, E.; Søtofte, Inger; Karup-Møller, S.

    2002-01-01

    contains three square pyramidal Bi sites, an octahedrally coordinated Bi site as well as two tetrahedrally and two irregularly coordinated Cu sites. The structure is an intergrowth of PbS-like slabs with irregularly configured slabs of Bi pyramids and Cu tetrahedra. It contains covalently bonded Se-2...

  18. Sample (S): SE3_S02 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE3_S02 Solanum lycopersicum House Momotaro fruit Solanum lycopersicum NCBI taxonom...y:4081 Solanum lycopersicum House Momotaro (ref: http://www.e-taneya.com/item/914.html) are grown at agricultural field under normal film in natural conditions. ...

  19. Det jordløse landbrug i industrikvarteret

    DEFF Research Database (Denmark)

    Rentz-Petersen, Nee

    2014-01-01

    Forskningsprojektet 'Det Jordløse Landbrug i Industrikvarteret' undersøger muligheder og konsekvenser ved at placere større landbrugsanlæg nær bynære industrikvarterer i Danmark. Projektet opstiller fire konkrete scenarier for fremtidens agro-industrikvarter, hvor fødevareproduktion kobles med bl...

  20. Electricity producer SE decided to solve crisis through offensive

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

    Instalment payments in this and the coming two years amount to 32 billion Sk (762.8 mn Euro) - that is about 60 percent of the overall credit burden of the electricity producer Slovenske elektrarne (SE). And so the situation from three years ago is repeating itself - a new financial department of the company is expected to lead the company out of the substantial cash-flow crisis caused by credit burden. This difficulties have been caused by decisions taken by state like building of power plant in Mochovce. Minister Nemcsics will not be in the position to complete his ambition to direct the activities of SE, his successor will need time to find his way and so the solution stays in hands of the company management. Where will they look for the necessary recourses? The operation generates virtually no cash-flow increase - reminds General Manager for Economy and Finances, Milos Sujansky. What the manager considers a possible solution is loan restructuring. 'We have to review the whole loan portfolio in order to eliminate the pressure caused by the necessity to repay the debts in 2004 and the beginning of 2005 and that would allow as to survive in a relatively normal state,' unveils the company plans M. Sujansky. That would mean postponing the instalment payments until 2007. Before this strategy was prepared the existing debts had to be analysed. The results of this analysis showed 'an inconsistent debt portfolio with many non-standard elements anchored in relevant contracts'. In the opinion of Director for External Financing this fact makes the loan management and decision making in regards to assets/liabilities structure difficult. 'When you have 35 different loans and every contract is different - communication and monitoring costs much effort,' he adds. According to an Auditors Report for 2002 prepared according to ISA standards even the share of third-party capital is high and inhomogeneous. The previous financial management managed to minimize the deficit. The fact

  1. Chemistry in CESM-SE: Evaluation, Performance and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Lamarque, Jean-Francois [National Center for Atmospheric Research, Boulder, CO (United States); Conley, Andrew [National Center for Atmospheric Research, Boulder, CO (United States); Vitt, Francis [National Center for Atmospheric Research, Boulder, CO (United States); Drake, John [Univ. of Tennessee, Knoxville, TN (United States); Sun, Jian [Univ. of Tennessee, Knoxville, TN (United States)

    2016-01-06

    The purpose of the proposed work focused on development of chemistry representation within the Spectral Element (SE) dynamical core as implemented in the Community Earth System Model (CESM). More specifically, a main focus was on the ability of SE to accurately represent tracer transport. The proposed approach was to incrementally increase the complexity of the problem, starting from specified two-dimensional flow and tracers to simulations using specified dynamics and full chemistry. As demonstrated below, we have successfully studied all aspects of the proposed work, although only part of the work has been published in the refereed literature so far. Furthermore, because the SE dynamical core has been found to have several deficiencies that are still being investigated for solution, not all proposed tasks were finalized. In addition to the tests for SE performance, in an effort to decrease the computational burden of interactive chemistry, especially in the case of a large number of chemical species and chemical reactions, development on a faster chemical solver and implementation on GPUs has been implemented in CESM under the leadership of John Drake (U. Tennessee).

  2. Exciton dephasing in ZnSe quantum wires

    DEFF Research Database (Denmark)

    Wagner, Hans Peter; Langbein, Wolfgang Werner; Hvam, Jørn Märcher

    1998-01-01

    The homogeneous linewidths of excitons in wet-etched ZnSe quantum wires of lateral sizes down to 23 nm are studied by transient four-wave mixing. The low-density dephasing time is found to increase with decreasing wire width. This is attributed mainly to a reduction of electron-exciton scattering...

  3. On the symmetry of phosphorous doped ZnSe

    Indian Academy of Sciences (India)

    The site symmetry of P doped ZnSe is analysed in detail here, as the recent experiments suggest two possible symmetries T d and C 3 V . The reduction to C 3 V is attributed to the presence of natural impurity, Ga. Our calculations based on molecular model and Green's functions suggest that the symmetry C 3 V is possible ...

  4. On the symmetry of phosphorous doped ZnSe

    Indian Academy of Sciences (India)

    Unknown

    Abstract. The site symmetry of P doped ZnSe is analysed in detail here, as the recent experiments suggest two possible symmetries Td and C3V. The reduction to C3V is attributed to the presence of natural impurity,. Ga. Our calculations based on molecular model and Green's functions suggest that the symmetry C3V is.

  5. Low temperature scintillation in ZnSe crystals

    Czech Academy of Sciences Publication Activity Database

    Dafinei, I.; Fasoli, M.; Ferroni, F.; Mihóková, Eva; Orio, F.; Pirro, S.; Vedda, A.

    2010-01-01

    Roč. 57, č. 3 (2010), 1470-1474 ISSN 0018-9499 Institutional research plan: CEZ:AV0Z10100521 Keywords : bolometers * double beta decay * scintillation detectors * ZnSe Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.519, year: 2010

  6. Specific heat of ZnCoSe semimagnetic semiconductor

    NARCIS (Netherlands)

    Twardowski, A.; Swagten, H.J.M.; Jonge, de W.J.M.; Demianiuk, M.

    1990-01-01

    The magnetic specific heat of ZnCoSe data are reported in the temperature range 1.5

  7. Tests of pancreatic function using /sup 75/Se--Selenomethionine

    Energy Technology Data Exchange (ETDEWEB)

    Krasner, N; Brodie, M J; Sumner, D J; Thomson, T J

    1976-04-01

    Pancreatic function was investigated in 43 patients using a combination of conventional and subtraction scans of the pancreas and duodenal aspiration of the /sup 75/Se-Selenomethionine injected, in the time periods 60 to 150 minutes, 90 to 120 minutes and 105 to 150 minutes after injection. Patients with chronic alcoholism, chronic pancreatitis, pancreatic carcinoma, extrahepatic biliary obstruction and liver disease were included. Seven patients with no evidence of gastro-intestinal disease served as controls. Pancreatic scanning provided eight false positive and two false negative results (23.3 percent) and with /sup 75/Se-Selenomethionine excretion at 105 to 150 minutes, six false results were obtained (14 percent). In only one patient was a false positive result obtained with both scans and the /sup 75/Se-Selenomethionine test. The performance of conventional and subtraction scans of the pancreas with measurement of /sup 75/Se-Selenomethionine activity in the duodenal aspirate collected from 105 to 150 minutes after injection provides a convenient means of testing pancreatic exocrine function in a single three hour session.

  8. Quantum chemistry of the minimal CdSe clusters

    Science.gov (United States)

    Yang, Ping; Tretiak, Sergei; Masunov, Artëm E.; Ivanov, Sergei

    2008-08-01

    Colloidal quantum dots are semiconductor nanocrystals (NCs) which have stimulated a great deal of research and have attracted technical interest in recent years due to their chemical stability and the tunability of photophysical properties. While internal structure of large quantum dots is similar to bulk, their surface structure and passivating role of capping ligands (surfactants) are not fully understood to date. We apply ab initio wavefunction methods, density functional theory, and semiempirical approaches to study the passivation effects of substituted phosphine and amine ligands on the minimal cluster Cd2Se2, which is also used to benchmark different computational methods versus high level ab initio techniques. Full geometry optimization of Cd2Se2 at different theory levels and ligand coverage is used to understand the affinities of various ligands and the impact of ligands on cluster structure. Most possible bonding patterns between ligands and surface Cd/Se atoms are considered, including a ligand coordinated to Se atoms. The degree of passivation of Cd and Se atoms (one or two ligands attached to one atom) is also studied. The results suggest that B3LYP/LANL2DZ level of theory is appropriate for the system modeling, whereas frequently used semiempirical methods (such as AM1 and PM3) produce unphysical results. The use of hydrogen atom for modeling of the cluster passivating ligands is found to yield unphysical results as well. Hence, the surface termination of II-VI semiconductor NCs with hydrogen atoms often used in computational models should probably be avoided. Basis set superposition error, zero-point energy, and thermal corrections, as well as solvent effects simulated with polarized continuum model are found to produce minor variations on the ligand binding energies. The effects of Cd-Se complex structure on both the electronic band gap (highest occupied molecular orbital-lowest unoccupied molecular orbital energy difference) and ligand binding

  9. Electronic structure and exchange interactions in diluted semimagnetic semiconductors (Zn,Co)Se and (Zn,Mn)Se

    Science.gov (United States)

    Mašek, J.

    1991-05-01

    A comparative study of the electronic structure of (Zn,Co)Se and (Zn,Mn)Se is done by using a tight-binding version of the coherent potential approximation. The densities of states, relevant for a photoemission experiment, are calculated for a magnetically disordered phase. The exchange constant Jpd is obtained from the splitting of the valence band top in the ferromagnetic phase of the mixed crystal; Jdd is estimated from the energy of a spin reversal. We explain the large exchange constant in the Co-based systems as a result of efficient hybridization of the d-states with the valence band.

  10. Complexing in the system Rb2SeO4-UO2SeO4-H2O

    International Nuclear Information System (INIS)

    Kuchumova, N.V.; Shtokova, I.P.; Serezhkina, L.B.; Serezhkin, V.N.

    1989-01-01

    Method of isothermal solubility at 25 deg C is used to study interaction of rubidium and uranyl selenates in aqueous solution. Formation of congruently soluble Rb 2 UO 2 (SeO 4 ) 2 x2H 2 O and Rb 2 (UO 2 ) 2 x(SeO 4 ) 3 x6H 2 O is stated. For the last compound crystallographic characteristics (a=10.668; b=14.935(9); c=13.891(7) A; β=104.94(1); Z=4, sp.gr. P2 1 /c) are determined. Thermal decomposition of a compound results in formation of Rb 2 U 2 O 7

  11. Neutron Activation Resonance Integrals of 74Se, 78Se, 80Se, 81Br, 127I, 130Te, 138Ba, 140Ce, and 142Ce

    International Nuclear Information System (INIS)

    Ricabarra, M. D.; Turjanskl, R.; Ricabarra, G. H.; Bigham, C.B.

    1968-01-01

    A lithium-drift germanium γ-ray spectrometer has been used to make accurate intercomparisons of the ratio of resonance-integral to thermal-activation cross section by measuring cadmium ratios or relative activation rates in two different neutron spectra. The standard, gold, or secondary standard, indium, was mixed uniformly in the samples and the activities resolved with the spectrometer. Expressed as Westcott S 0 values, the results relative to S 0 = 17.7 for gold were as follows: 74 Se = 10.3 +± 0.1, 78 Se = 12.3 ± 0.3, 80 Sc = 2.65 ± 0.02, 81 Br = 24.3 ± 0.5, 127 I = 27.8 ± 0.5, 130 Te = 2.10 ± 0.07, 138 Ba = 0.649 ± 0.004, 140 Ce = 0.476 ± 0.003, 142 Ce = 0.865 ± 0.005. (author)

  12. Effect of lattice disorder on the thermal conductivity of ZnBeSe, ZnMgSe and ZnBeMgSe crystals

    International Nuclear Information System (INIS)

    Strzałkowski, K.

    2015-01-01

    Zn 1−x−y Be x Mg y Se mixed crystals investigated in this work were grown from the melt by the high pressure high temperature modified Bridgman method in the range of composition 0 < x,y < 0.33. Photopyroelectric (PPE) calorimetry in the back (BPPE) and front (FPPE) configuration was applied for thermal investigation of solid samples. The thermal diffusivity and effusivity of investigated crystals were derived from the experimental data. Since dynamic thermal parameters are connected with each other, thermal conductivity of the specimens was calculated from theoretical dependencies between them. The influence of the beryllium (x) and magnesium (y) content on thermal properties of these crystals have been presented and discussed. Order-disorder effects observed for these materials previously have been also taken into account. Finally, thermal diagrams, i.e. thermal conductivity versus composition were presented and discussed applying model given by Sadao Adachi. - Highlights: • Investigated II–VI crystals were obtained by a high pressure modified Bridgman method. • A complete thermal characterization of Zn 1−x−y Be x Mg y Se semiconductors was carried out. • The effect of lattice disorder on thermal properties was presented and discussed. • Obtained data were analyzed applying lattice thermal conductivity model. • Contribution to thermal resistivity arising from lattice disorder was calculated

  13. Que es lo que queda cuando el agua se va

    Directory of Open Access Journals (Sweden)

    Hernán Ascui Fernández

    2007-10-01

    Full Text Available El agua siempre deja huellas de su paso. Las aguas del Nilo, después de inundar las llanuras del río, se retiraban dejando el suelo colmado de los nutrientes que habían traído desde el corazón de África. Las costas de Chile han sido modeladas por el ir y venir de las aguas marinas, el río Ibáñez ha esculpido un profundo canal en la roca para abrirse paso, dando nacimiento a un magnífico lugar conocido como Garganta del río Ibáñez. Las cascadas horadan montañas para poder deslizarse como blancas lágrimas, la sobrecogedora belleza de los glaciares ha dejado potentes huellas de sus trayectorias. La lluvia también deposita marcas en los lugares y superficies que moja. A veces son apenas sutiles señales como el musgo que crece en las piedras húmedas o en el perfume de los bosques de Valdivia, con su tierra negra y empapada de lluvia y rocío. Otras veces las huellas del agua están presentes en la arquitectura como ocurre con los palafitos de Castro o Caleta Tortel, donde las casas se levantan para tomar distancia del agua que se mueve al ritmo de las mareas. En otras ocasiones, las huellas del descorren el velo de un drama urbano; es lo que ocurrió con la inundación del invierno pasado. Las huellas del agua aún son visibles en las paredes manchadas, en los muebles, en los pisos. El agua se fue pero dejando tras de sí un desalentador recuerdo de su paso por las ciudades, los pueblos y las casas.

  14. Sensor Exposure, Exploitation, and Experimentation Environment (SE4)

    Science.gov (United States)

    Buell, D.; Duff, F.; Goding, J.; Bankston, M.; McLaughlin, T.; Six, S.; Taylor, S.; Wootton, S.

    2011-09-01

    As the resident space object population increases from new launches and events such as the COSMOS/IRIDIUM collision, the maintenance of high-level Space Situational Awareness (SSA) has become increasingly difficult. To maintain situational awareness of the changing environment, new systems and methods must be developed. The Sensor Exposure, Exploitation and Experimentation Environment (SE4) provides a platform to illustrate “The Art of the Possible” that shows the potential benefit of enriched sensor data collections and real-time data sharing. Through modeling and simulation, and a net-centric architecture, SE4 shows the added value of sharing data in real-time and exposing new types of sensor data. The objective of SE4 is to develop an experimentation and innovation environment for sensor data exposure, composable sensor capabilities, reuse, and exploitation that accelerates the delivery of needed Command and Control, Intelligence, Surveillance, and Reconnaissance capabilities to the warfighter. Through modeling, simulation and rapid prototyping, the art of the possible for a fully-connected, net-centric space Command and Control (C2) and sensor enterprise can be demonstrated. This paper provides results that demonstrate the potential for faster cataloging of breakup events and additional event monitoring that are possible with data available today in the Space Surveillance Network (SSN). Demonstrating the art of the possible for the enterprise will guide net-centric requirements definition and facilitate discussions with stakeholder organizations on the Concept of Operations (CONOPS), policy, and Tactics, Techniques, and Procedures (TTP) evolution necessary to take full advantage of net-centric operations. SE4 aligns with direction from Secretary Gates and the Chairman Joint Chief of Staff that emphasizes the need to get the most out of our existing systems. Continuing to utilize SE4 will enable the enterprise by demonstrating the benefits of applying

  15. Photoinduced interaction of CdSe quantum dot with coumarins

    Energy Technology Data Exchange (ETDEWEB)

    El-Kemary, Maged, E-mail: elkemary@sci.kfs.edu.eg [Nanotechnology Center, Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh (Egypt); Gaber, Mohamed; El-Sayed, Y.S. [Chemistry Department, Faculty of Science, University of Tanta, Tanta (Egypt); Gheat, Youssef [Nanotechnology Center, Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh (Egypt); Chemistry Department, Faculty of Science, University of Tanta, Tanta (Egypt)

    2015-03-15

    Cadmium selenide (CdSe) quantum dots (QDs) were synthesized with a cubic shape having a diameter of ∼5.24 nm. The prepared CdSe QDs were characterized by using UV–visible, Fourier transform infrared (FTIR), powder X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The UV–visible absorption spectra indicate that the optical band gap of CdSe QDs is ∼622 nm and the peak shift can mainly be due to the quantum size effects. The fluorescence decay kinetics for the synthesized QDs was followed by time-resolved fluorescence spectroscopy, and the spectra were analyzed in regard to a bi-exponential model to identify two lifetime values, that is, shorter-lifetime 1.37 ns (55%) and longer-lifetime 6.58 ns (45%). The interaction of coumarin 152 (C152) and coumarin 153 (C153) with QDs surface brings about further considerable changes in the absorption and fluorescence patterns. The calculated binding constant from fluorescence quenching method matches well with that determined from the absorption spectral changes. The static quenching mechanism was confirmed by large magnitude of K{sub SV} and unaltered fluorescence lifetime. - Highlights: • CdSe QDs were synthesized with a cubic shape having a diameter of ∼5.24 nm. • The UV–visible absorption spectra indicate that the optical band gap of CdSe QDs is ∼622 nm. • Picosecond fluorescence measurements of the QDs suggest bi-exponential function. • The calculated binding constant from fluorescence quenching method matches well with that determined from the absorption spectral changes. • The static quenching mechanism was confirmed by large magnitude of K{sub SV} and unaltered fluorescence lifetime.

  16. Synthesis, crystal structure, optical, and electronic study of the new ternary thorium selenide Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); Mesbah, Adel [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); ICSM, UMR 5257 CEA/CNRS/UM2/ENSCM, Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Beard, Jessica [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); Lebègue, Sébastien [Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2, UMR CNRS 7036), Institut Jean Barriol, Université de Lorraine, BP 239, Boulevard des Aiguillettes, 54506 Vandoeuvre-lès-Nancy (France); Malliakas, Christos D. [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States); Ibers, James A., E-mail: ibers@chem.northwestern.edu [Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 (United States)

    2015-11-15

    The compound Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} has been synthesized by solid-state methods at 1173 K. Its crystal structure features one-dimensional chains of {sup 1}{sub ∞}[Th(Se){sub 3}(Se{sub 2}){sub 2}{sup 6−}] separated by Ba{sup 2+} cations. Each Th atom in these chains is coordinated to two Se–Se single-bonded pairs and four Se atoms to give rise to a pseudooctahedral geometry around Th. The Th–Se distances are consistent with Th{sup 4+} and hence charge balance of Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} is achieved as 3×Ba{sup 2+}, 1×Th{sup 4+}, 3×Se{sup 2−}, and 2×Se{sub 2}{sup 2−}. From optical measurements the band gap of Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} is 1.96(2) eV. DFT calculations indicate that the compound is a semiconductor. - Graphical abstract: Local coordination environment of Th atoms in the Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} structure. - Highlights: • Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} has been synthesized by solid-state methods at 1173 K. • The structure features chains of {sup 1}{sub ∞}[Th(Se){sub 3}(Se{sub 2}){sub 2}{sup 6−}] separated by Ba{sup 2+} cations. • Ba{sub 3}ThSe{sub 3}(Se{sub 2}){sub 2} is a semiconductor with a band gap of 1.96(2) eV.

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

    Science.gov (United States)

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

  18. Qué hace el cuidador familiar en el hospital: Cómo se ve a sí mismo y cómo lo ven los profesionales The role of the family caregivers in the hospital: Their self-concept and how they are seen by health professionals

    Directory of Open Access Journals (Sweden)

    Rafael Villar Dávila

    2012-03-01

    Full Text Available Los cuidadores familiares han sido ampliamente estudiados en el ámbito domiciliario y de la atención primaria pero prácticamente no existen estudios que incidan sobre su realidad dentro de los hospitales. Con un enfoque cuantitativo y diseño descriptivo transversal mediante el uso de cuestionarios validados al efecto realizado a familiares que cuidan a ancianos ingresados en los hospitales se conoce el perfil de los mismos, qué actividades realizan y qué valoración hacen de ellos los profesionales de enfermería. Como conclusiones principales destacar: a Las principales actividades del cuidador familiar en el hospital son de acompañamiento, entretenimiento, soporte emocional e intermediación. b El desconocimiento de la actividad inhiben al cuidador familiar a realizar más actividades. c Si se educa y entrena al cuidador familiar en las actividades de cuidado, se harán más. d Los profesionales desconocen lo que los familiares dicen que hacen. No consideran que muchas de las acciones del cuidador sean realmente cuidados. Creen que los cuidadores familiares no ayudan tanto como ellos esperan al cuidado básico de los ancianos ingresados.Family caregivers have been widely studied in the home and primary care but virtually do no exits studies which influence the reality in hospitals. With a quantitative approach and cross-sectional design using questionnaires validated for that purpose made to relatives who care for elderly people in hospitals is called the profile them, what activities do and what makes them value the nurses. As main findings include: a The main activities of family caregivers in the hospital are accompanying, entertainment, emotional support and brokerage. b Lack of activity inhibit the family caregiver to be more active. c If you educate and train the family caregiver in activities of care, will be more. d Professionals know what family members say they do. Do not think that many of the actions of the caregiver are

  19. Constraining the cross section of 82Se(n, γ)83Se to validate the β-Oslo method

    Science.gov (United States)

    Childers, K.; Liddick, S. N.; Crider, B. P.; Dombos, A. C.; Lewis, R.; Spyrou, A.; Couture, A.; Mosby, S.; Prokop, C. J.; Naqvi, F.; Larsen, A. C.; Guttormsen, M.; Campo, L. C.; Renstrom, T.; Siem, S.; Bleuel, D. L.; Perdikakis, G.; Quinn, S.

    2017-09-01

    Neutron capture cross sections of short-lived nuclei are important for a variety of basic and applied nuclear science problems. However, because of the short half-lives of the nuclei involved and the nonexistence of a neutron target, indirect measurement methods are required. One such method is the β-Oslo method. The nuclear level density and γ strength function of a nucleus are extracted after β-decay and used in a statistical reaction model to constrain the neutron capture cross section. This method has been used previously, but must be validated against a directly measured neutron capture cross section. The neutron capture cross section of 82Se has been measured previously, and 83Se can be accessed by the β-decay of 83As. The β-decay of 83As to 83Se was studied using the SuN detector at the NSCL and the β-Oslo method was utilized to constrain the neutron capture cross section of 82Se, which is compared to the directly measured value.

  20. Tests for the absorption of /sup 75/Se-labelled homocholic acid conjugated with taurine (/sup 75/Se-HCAT)

    Energy Technology Data Exchange (ETDEWEB)

    Schroth, H.J.; Berberich, R.; Mueller, K.P.; Feifel, G.; Ecker, K.W.

    1985-05-01

    The absorption of selenomethionine Se 75-labelled homocholic acid conjugated with taurine (/sup 75/-SE-HCAT) was tested in 46 patients. Retention measurements using (1) an uncollimated gamma camera and (2) a measuring arrangement similar to a human-body counter were compared in order to obtain a quantitative assessment of the absorption capacity of the terminal ileum for bile acids. The retention curve obtained after the oral administration of the /sup 75/Se-labelled bile-acid analogue showed a monoexponential decline; in the case of unimpaired absorption, the half-life was greater than 2.5 days. When more than 30 cm of the ileum had been eliminated by inflammatory infection or resection, the measured half-life was below 0.5 days due to malabsorption. We also performed a quantitative determination of the hepatic secretion of /sup 75/-Se-HCAT into the gall bladder. If more than 80% of the activity administered is found in the gall bladder, disturbed absorption of bile acids in the terminal ileum can be excluded. Values smaller than 80%, however, do not provide proof of disturbed absorption.

  1. CdSe quantum dot in vertical ZnSe nanowire and photonic wire for efficient single-photon emission

    DEFF Research Database (Denmark)

    Cremel, Thibault; Bellet-Amalric, Edith; Cagnon, Laurent

    conformal dielectric coating of Al2O3 on the NW-QDs using Atomic Layer Deposition so that a photonic wire is formed with the CdSe QD deterministically positioned on its axis. The collection enhancement effect is studied by measuring the emission (with pulse excitation, at saturation intensity) of single...

  2. Complexation in the system K2SeO4-UO2SeO4-H2O

    International Nuclear Information System (INIS)

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

    1994-01-01

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

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

    Science.gov (United States)

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

    2017-12-15

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

  4. Influence of Se concentrations and species in hydroponic cultures on Se uptake, translocation and assimilation in non-accumulator ryegrass.

    Science.gov (United States)

    Versini, Antoine; Di Tullo, Pamela; Aubry, Emmanuel; Bueno, Maïté; Thiry, Yves; Pannier, Florence; Castrec-Rouelle, Maryse

    2016-11-01

    The success of biofortification and phytoremediation practices, addressing Se deficiency and Se pollution issues, hinges crucially on the fate of selenium in the plant media in response to uptake, translocation and assimilation processes. We investigate the fate of selenium in root and shoot compartments after 3 and 6 weeks of experiment using a total of 128 plants grown in hydroponic solution supplied with 0.2, 2, 5, 20 and 100 mg L -1 of selenium in the form of selenite, selenate and a mixture of both species. Selenate-treated plants exhibited higher root-to-shoot Se translocation and total Se uptake than selenite-treated plants. Plants took advantage of the selenate mobility and presumably of the storage capacity of leaf vacuoles to circumvent selenium toxicity within the plant. Surprisingly, 28% of selenate was found in shoots of selenite-treated plants, questioning the ability of plants to oxidize selenite into selenate. Selenomethionine and methylated organo-selenium amounted to 30% and 8% respectively in shoots and 35% and 9% in roots of the identified Se, suggesting that selenium metabolization occurred concomitantly in root and shoot plant compartments and demonstrating that non-accumulator plants can synthesize notable quantities of precursor compound for volatilization. The present study demonstrated that non-accumulator plants can develop the same strategies as hyper-accumulator plants to limit selenium toxicity. When both selenate and selenite were supplied together, plants used selenate in a storage pathway and selenite in an assimilation pathway. Plants might thereby benefit from mixed supplies of selenite and selenate by saving enzymes and energy required for selenate reduction. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Degradação redutiva de azo-corantes utilizando-se ferro metálico Reductive degradation of azo-dyes by metallic iron

    Directory of Open Access Journals (Sweden)

    Cláudio Lima de Souza

    2006-03-01

    Full Text Available Corantes azo são extensivamente utilizados em processos de tingimento de fibras têxteis, sendo caracterizados por elevada resistência frente a processos aeróbios de biodegradação e, por conseqüência, persistência nos processos convencionais de tratamento de resíduos. Neste trabalho reporta-se a degradação redutiva de corantes azo, utilizando-se ferro metálico. Em condições experimentais otimizadas (pH 7 e 10 g de lã de aço comercial a completa descoloração do corante modelo (preto reativo 5 foi conseguida em um sistema contínuo, operando com tempos de retenção de 6 min. Nestas condições, o ferro solubilizado alcança concentrações compatíveis com os limites impostos pela atual legislação brasileira (12 mg L-1. Trata-se de um resultado bastante promissor, principalmente levando-se em consideração o caráter recalcitrante dos azo corantes e a simplicidade do sistema proposto.Azo dyes are extensively used in textile dying processes and are characterized by extreme resistance to biodegradation and consequently persistence during conventional wastewater treatment processes. In this work the reductive degradation of azo dyes was studied using zero-valent iron. At optimized experimental conditions (pH 7 and 10 g of commercial iron wool complete decolorization of the model dye (reactive black 5 was afforded in a continuous system operating with hydraulic retention time of 6 min. At these conditions the released total soluble iron reaches a concentration compatible with the limits imposed by the current Brazilian legislation (12 mg L-1. That is a very promising result, mainly taking into account the high recalcitrant character of azo dyes and the simplicity of the proposed system.

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

    Science.gov (United States)

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

    2015-02-01

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

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

    Science.gov (United States)

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

    2013-07-03

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

  8. Superconductivity at high pressure in NbSe3

    International Nuclear Information System (INIS)

    Nunez Regueiro, M.; Castello, D.; Mignot, J.M.

    1992-01-01

    We have measured the electrical resistivity of NbSe 3 between 2 K and room temperature up to a pressure of 7.2 GPa. At P 1 = 3.5 GPa we observe the extinction of the high-temperature charge density wave (T 1 -CDW) and the enhancement of the superconducting critical temperature T c to ≅ 5 K. The logarithmic pressure slopes of T 1 (P 1 ) and T c (P > P 1 ) are found to be practically equal. A similar behaviour had been reported previously at lower pressures for T 2 (P 2 ) and T c (P 2 1 ) in the distorted state. We discuss these results in terms of an anisotropic superconducting state in NbSe 3 , with different gaps associated with different types of chains. 10 refs., 2 figs

  9. Electronically-driven orthorhombic distortion in FeSe

    Science.gov (United States)

    Watson, Matthew; Davies, Nathaniel; Haghighirad, Amir; Narayanan, Arjun; Kim, Timur; Hoersch, Moritz; Blake, Samuel; Coldea, Amalia

    2015-03-01

    FeSe is structurally the simplest of Fe-based superconductors, and exhibits a tetragonal-to-orthorhombic structural transition at ~ 90 K, but no long-range magnetism at any temperature. We report measurements of the resistivity anisotropy in FeSe above Ts finding a large and divergent response to an applied strain, with a comparable magnitude and temperature-dependence to measurements in Ba(Fe1-xCox)2As2, but opposite sign. We compare this data with literature reports on NMR and our own ARPES data, which taken together indicate that the structural transition is electronically-driven with orbital degrees of freedom playing a central role. This work was supported by EPSRC, UK (EP/I004475/1) and Diamond Light Source.

  10. Optical nonlinear absorption characteristics of Sb2Se3 nanoparticles

    Science.gov (United States)

    Muralikrishna, Molli; Kiran, Aditha Sai; Ravikanth, B.; Sowmendran, P.; Muthukumar, V. Sai; Venkataramaniah, Kamisetti

    2014-04-01

    In this work, we report for the first time, the nonlinear optical absorption properties of antimony selenide (Sb2Se3) nanoparticles synthesized through solvothermal route. X-ray diffraction results revealed the crystalline nature of the nanoparticles. Electron microscopy studies revealed that the nanoparticles are in the range of 10 - 40 nm. Elemental analysis was performed using EDAX. By employing open aperture z-scan technique, we have evaluated the effective two-photon absorption coefficient of Sb2Se3 nanoparticles to be 5e-10 m/W at 532 nm. These nanoparticles exhibit strong intensity dependent nonlinear optical absorption and hence could be considered to have optical power limiting applications in the visible range.

  11. HORMIGAS QUE (SE OBSESIONAN: UNA TRADUCCIÓN EN ORATURA

    Directory of Open Access Journals (Sweden)

    Kyle Wanberg

    2014-10-01

    Full Text Available En el presente estudio, se examina una traducción de las Canciones de las Hormigas (Ant Songs, de transmisión oral, del ‘akimel ‘o‘odham (pima al inglés y se hace hincapié en cómo los problemas de traducción transfiguran su recepción en tanto que obras literarias. Un análisis de su canto, su lenguaje, sus códigos culturales y su oralidad arroja algo de luz sobre un territorio extraordinariamente ambiguo. El estudio de esta y otras traducciones de oratura, incluidas las dificultades que estas ponen de manifiesto, puede enriquecer nuestra concepción tanto de la literatura como de la traducción.

  12. Kristeva's Thérèse: Mysticism and Modernism

    Directory of Open Access Journals (Sweden)

    Carol Mastrangelo Bové

    2013-05-01

    Full Text Available This essay focuses on Julia Kristeva’s recent volume Thérèse mon amour:  Sainte Thérèse d’Avila (2008, describing and placing this blend of novel, play, psychoanalytic cultural theory, and case history in the context of her work.  I argue that the volume contributes to an understanding of religion’s impact—especially Catholic mysticism--on Western categories of women.  I address in particular Thérèse’s mysticism and modernist use of a feminine figure to subvert practices threatening the vitality of the psyche and of social relations.  As in Kristeva’s earlier writing, her psychoanalytic approach to Catholicism’s influence continues to raise questions concerning the apparent stereotypes the approach may feed, especially that of the masochistic woman.

  13. High temperature XRD of Cu2GeSe3

    International Nuclear Information System (INIS)

    Premkumar, D. S.; Malar, P.; Chetty, Raju; Mallik, Ramesh Chandra

    2015-01-01

    The Cu 2 GeSe 3 is prepared by solid state synthesis method. The high temperature XRD has been done at different temperature from 30 °C to 450 °C. The reitveld refinement confirms Cu 2 GeSe 3 phase and orthorhombic crystal structure. The lattice constants are increasing with increase in the temperature and their rate of increase with respect to temperature are used for finding the thermal expansion coefficient. The calculation of the linear and volume coefficient of thermal expansion is done from 30 °C to 400 °C. Decrease in the values of linear expansion coefficients with temperature are observed along a and c axis. Since thermal expansion coefficient is the consequence of the distortion of atoms in the lattice; this can be further used to find the minimum lattice thermal conductivity at given temperature

  14. Characterization of CdSe polycrystalline films by photoluminescence spectroscopy

    International Nuclear Information System (INIS)

    Brasil, M.J.S.P.

    1985-01-01

    The characterization of CdSe polycristalline films were done by photoluminescence spectroscopy, X-ray diffraction analysis, diagrams IxV, and efficiency of solar energy conversion for cells done by these films. The experimental data shown strong temperature dependence of annealing, and the optimum temperature around 650 0 C was determined. The films did not present photoluminescence before heat treatment, but the annealed sample spectrum showed fine structures in the excitonic region, crystal phase transformation, enhancement of grain size, and better efficiency of the cell. Measurements of photoluminescence between 2 and 300 K, showed two bands of infrared emission, width and intense enough. The shape, at half-width, and the integrated intensity of one these bands were described by a configuration coordinate model for deep centers. Based on obtained results, some hypothesis about the origin of these bands and its correlation with efficiency of cells done with CdSe polycrystalline films, are proposed. (M.C.K.) [pt

  15. Doping mechanism in pure CuInSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Werner, F.; Colombara, D.; Melchiorre, M.; Spindler, C.; Siebentritt, S. [Physics and Materials Science Research Unit, University of Luxembourg, Rue du Brill 41, L-4422 Belvaux (Luxembourg); Valle, N.; El Adib, B. [Materials Research and Technology Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422 Belvaux (Luxembourg)

    2016-05-07

    We investigate the dopant concentration and majority carrier mobility in epitaxial CuInSe{sub 2} thin films for different copper-to-indium ratios and selenium excess during growth. We find that all copper-poor samples are n-type, and that hopping conduction in a shallow donor state plays a significant role for carrier transport. Annealing in sodium ambient enhances gallium in-diffusion from the substrate wafer and changes the net doping of the previously n-type samples to p-type. We suggest that sodium incorporation from the glass might be responsible for the observed p-type doping in polycrystalline Cu-poor CuInSe{sub 2} solar cell absorbers.

  16. Los datos: la cancha donde se juega la democracia

    Directory of Open Access Journals (Sweden)

    Omar Rincón

    2016-08-01

    Full Text Available La guerra de los datos existe. La guerra, por ahora, la va ganando el capital, las empresas y los gobiernos. Jobs-Zuckerberg-Page-Bezos-EE.UU. y todos los gobiernos están cerca del control total de los datos sobre los sujetos y la sociedad. Nos persiguen y encuentran gracias a nuestras intimidades conectadas. Lo peor, parecemos felices entregados a la vigilancia y el control. En este contexto, los datos son la cancha donde se está jugando la democracia. En este texto-ensayo se pasa del optimismo tecnológico (el big data es solo una tecnología y una maravilla que lo puede todo, a la ironía de la tecnología como dispositivo de poder y al cinismo del big data como ideología.

  17. An Account of Señorita Maquiladora

    Directory of Open Access Journals (Sweden)

    Rosina Conde

    2008-06-01

    Full Text Available Performer and scholar Rosina Conde finds that Señorita Maquiladora is the performance piece that has gone through the most transformations, not in its script, but in its text, as it is constantly being rewritten to speak to contemporary social issues. She believes that Señorita Maquiladora has potential because it speaks to global themes that affect workers in the assembly plant industry, not only with respect to the questions of the environment and health, but also in terms of the patriarchial patterns that force these women to compete in an atmosphere of a vertical structure dominated by men, with all the attendant disadvantages, without taking into account that women are responsible for procreation. Feminicide, health problems like breast and uterine cancer, and the birth of anacephalic children are only a few conditions suffered by this group of women who remain today the most vulnerable sector of the Mexican workforce.

  18. Epitaxial growth of CZT(S,Se) on silicon

    Science.gov (United States)

    Bojarczuk, Nestor A.; Gershon, Talia S.; Guha, Supratik; Shin, Byungha; Zhu, Yu

    2016-03-15

    Techniques for epitaxial growth of CZT(S,Se) materials on Si are provided. In one aspect, a method of forming an epitaxial kesterite material is provided which includes the steps of: selecting a Si substrate based on a crystallographic orientation of the Si substrate; forming an epitaxial oxide interlayer on the Si substrate to enhance wettability of the epitaxial kesterite material on the Si substrate, wherein the epitaxial oxide interlayer is formed from a material that is lattice-matched to Si; and forming the epitaxial kesterite material on a side of the epitaxial oxide interlayer opposite the Si substrate, wherein the epitaxial kesterite material includes Cu, Zn, Sn, and at least one of S and Se, and wherein a crystallographic orientation of the epitaxial kesterite material is based on the crystallographic orientation of the Si substrate. A method of forming an epitaxial kesterite-based photovoltaic device and an epitaxial kesterite-based device are also provided.

  19. Señales purinérgicas Purinergic signals

    Directory of Open Access Journals (Sweden)

    Eduardo R Lazarowski

    2009-04-01

    Full Text Available En la última década se ha aportado clara evidencia de que tanto nucleósidos como nucleótidos de adenina y uridina pueden funcionar como factores de señalización extracelular. Su acción es mediada por dos tipos principales de receptores de superficie denominados purinérgicos. Los receptores P1 se activan por adenosina, y son todos metabotrópicos, mientras que los receptores de nucleótidos (ATP, ADP, UTP y UDP y nucleótidos-azúcares (UDP-glucosa y UDP-galactosa pueden ser metabotrópicos (P2Y o ionotrópicos (P2X. La importancia y complejidad de este sistema de señalización se evidencia por la diversidad de mecanismos de liberación de nucleótidos al medio extracelular y por la distribución ubicua de varios grupos de ectonucleotidasas capaces de catalizar la degradación y conversión de nucleótidos. Hasta el momento se han descrito y clonado una veintena de estos receptores que modulan una variedad de respuestas, como el impulso nervioso, la respuesta inflamatoria, la secreción de insulina, la regulación del tono vascular y la percepción del dolor. En la presente revisión se describen las características estructurales y farmacológicas de los receptores purinérgicos y se analiza la interacción dinámica entre estos receptores, los nucleósidos y nucleótidos, y las ectonucleotidasas, con especial atención a la dinámica de la agregación plaquetaria, la respuesta inmune y la hidratación de las mucosas respiratorias.In the last decade evidence accumulated that nucleosides and nucleotides of both uridine and adenine can act as extracellular signaling factors. Their action is mediated by two main types of surface receptors commonly known as purinergic. P1 receptors are metabotropic and activated by adenosine, whereas receptors for nucleotides (ATP, ADP, UTP and UDP and nucleotide-sugars (UDP-glucose and UDP-galactose can be either metabotropic (P2Y or ionotropic (P2X. The importance and complexity of this signaling system

  20. /sup 75/Se selenomethionine in the diagnosis of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, J G; Zambartas, C N; Sumerling, M D; Finlayson, N D.C.

    1981-02-01

    A 74 year old man presented with cryptogenic liver cirrhosis and ascites. On /sup 99/Tcsup(m) sulphur colloid scanning he was found to have a filling defect in the right lobe of the liver which disappeared when the liver scan was repeated with /sup 75/Se selenomethionine. This lesion, initially thought to be a hepatoma, proved eventually at post mortem to be a hyperplastic hepatic nodule.