El impacto de la apertura económica sobre el sistema de transporte y el desarrollo regional en Colombia

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Jan Marco Mu00FCller

2004-01-01

Full Text Available Con base en las condiciones físico-geográficas, demográficas e históricas del sistema de transporte colombiano, el presente estudio investiga el impacto que la apertura económica ha tenido sobre el transporte en Colombia desde 1990. Se analizan los problemas generados o agravados por la apertura y se evalúan las estrategias aplicadas por el gobierno para contrarrestar dichos efectos, así como el impacto de las mismas sobre las disparidades regionales. El estudio llega a la conclusión que la apertura económica generó un fuerte aumento de los volúmenes de transporte el cual benefició principalmente al modo carretero, generando problemas como embotellamientos y un deterioro de la infraestructura. Al mismo tiempo, la creciente dependencia del país de este modo de transporte aumentó la vulnerabilidad del sistema de transporte en general. A pesar de que las medidas adoptadas por el gobierno llevaron hacia un sistema más eficiente gracias a la colaboración del sector privado, al mismo tiempo se agravaron las disparidades regionales.

The transport and distribution of 3H-ABA affected by al sress on soybean seedig

International Nuclear Information System (INIS)

Chen Guang; Sun Yang; Pang Jinduo

2010-01-01

A hydroponic experiment combining radioisotope techniques was carried out to understand the effect of Al stress on the transport and the distribution of 3 H-ABA by using Jilin70, a soybean variety of Al resistance. The transport and distribution of ABA affected by Al stress on soybean seedling were studied with radioisotope technique. The results showed that ABA could be transported up or down in soybean seedling. The stress of Al accelerated the transport of ABA and enhanced the distribution of ABA in the roots by Al stress. The paper present the foundation for the mechanisms of ABA under Al stress in plant. (authors)

Análise do conceito de tecnologia educacional em enfermagem aplicada ao paciente

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Aline Cruz Esmeraldo Áfio

2014-01-01

Full Text Available El objetivo fue analizar el concepto de tecnología educacional, producido por la Enfermería, aplicada al paciente. Se utilizó el Modelo de Evolución de Análisis del Concepto, identificándose antecedentes, atributos, y consecuentes. Se seleccionaron 13 artículos para análisis, donde se identificaron los antecedentes: deficiencia de conocimiento, escasez de tiempo de los profesionales de enfermería, optimización del trabajo da enfermería, necesidad de alcanzar metas de pacientes; atributos: herramienta, estrategia, abordaje innovador, enfoque pedagógico, mediadora de conocimientos, forma creativa de estimular la adquisición de competencias, instrumento de producción de salud; consecuentes: mejora de calidad de vida, estímulo a comportamientos saludables, empoderamiento, reflexión y vínculo. Se enfatiza la importancia de las tecnologías educacionales para la atención de enfermería, al dinamizar actividades de educación en salud.

Alloy scattering dependence of electron transport in AlGaN

International Nuclear Information System (INIS)

Yarar, Z.; Ozdemir, M.

2010-01-01

The electron transport and velocity characteristics in AlGaN are examined using an ensemble Monte Carlo simulation method. A three valley band structure model where nonparabolicity effects are considered in all valleys is used for Monte Carlo calculations. All of the major electron scattering interactions like acoustic and optical phonon, intervaley, ionized impurity and alloy disorder scatterings are included in the calculations. The velocity-applied electric field characteristics are analyzed as a function of Al molar fraction and temperature in the ranges of x=0.1 to x=0.5 and 77 K to 500 K, respectively. The velocity overshoot is clearly observed and the population of valleys seems well-matched with the occupancy of valleys in AlGaN. The results of electron steady state velocity-field curves are found that the alloy disorder scattering has important effects on the electron transport characteristics of AlGaN.

Forward Current Transport Mechanisms of Ni/Au—InAlN/AlN/GaN Schottky Diodes

Science.gov (United States)

Wang, Xiao-Feng; Shao, Zhen-Guang; Chen, Dun-Jun; Lu, Hai; Zhang, Rong; Zheng, You-Dou

2014-05-01

We fabricate two Ni/Au-In0.17Al0.83N/AlN/GaN Schottky diodes on substrates of sapphire and Si, respectively, and investigate their forward-bias current transport mechanisms by temperature-dependent current-voltage measurements. In the temperature range of 300-485 K, the Schottky barrier heights (SBHs) calculated by using the conventional thermionic-emission (TE) model are strongly positively dependent on temperature, which is in contrast to the negative-temperature-dependent characteristic of traditional semiconductor Schottky diodes. By fitting the forward-bias I-V characteristics using different current transport models, we find that the tunneling current model can describe generally the I-V behaviors in the entire measured range of temperature. Under the high forward bias, the traditional TE mechanism also gives a good fit to the measured I-V data, and the actual barrier heights calculated according to the fitting TE curve are 1.434 and 1.413 eV at 300K for InAlN/AlN/GaN Schottky diodes on Si and the sapphire substrate, respectively, and the barrier height shows a slightly negative temperature coefficient. In addition, a formula is given to estimate SBHs of Ni/Au—InAlN/AlN/GaN Schottky diodes taking the Fermi-level pinning effect into account.

Theoretical prediction of the electronic transport properties of the Al-Cu alloys based on the first-principle calculation and Boltzmann transport equation

Science.gov (United States)

Choi, Garam; Lee, Won Bo

Metal alloys, especially Al-based, are commonly-used materials for various industrial applications. In this paper, the Al-Cu alloys with varying the Al-Cu ratio were investigated based on the first-principle calculation using density functional theory. And the electronic transport properties of the Al-Cu alloys were carried out using Boltzmann transport theory. From the results, the transport properties decrease with Cu-containing ratio at the temperature from moderate to high, but with non-linearity. It is inferred by various scattering effects from the calculation results with relaxation time approximation. For the Al-Cu alloy system, where it is hard to find the reliable experimental data for various alloys, it supports understanding and expectation for the thermal electrical properties from the theoretical prediction. Theoretical and computational soft matters laboratory.

Servicios auxiliares asociados al transporte marítimo

OpenAIRE

Godes Gallardo, Daniel

2014-01-01

En este proyecto, mi intención es profundizar en los servicios auxiliares asociados al transporte marítimo, como su título indica. En él haré referencia a todos los servicios que el transporte marítimo en sí, y más en concreto los buques, utilizan cada vez que entran a puerto.En algunos casos, estos servicios no se prestan en las instalaciones del puerto, como pueden ser los servicios exclusivospara la explotación comercial del buque. Hay que tener en cuenta que, se podría hacer un trabajo...

La teoría de los conjuntos-T aplicada al desarrollo de la competencia de modelado matemático

Directory of Open Access Journals (Sweden)

RICARDO JOAQUÍN DE ARMAS COSTA

2016-06-01

Full Text Available En este artículo queremos dar a conocer apartes de la teoría de los conjuntos-T y cómo se aplica en la educación superior para desarrollar la competencia de modelado matemático de los sujetos. Esta teoría surge como respuesta a los problemas de enseñanza aprendizaje de las matemáticas que se originan en los programas curriculares diseñados para adquirir exclusivamente información y no para desarrollar las competencias matemáticas de los estudiantes. The theory of the Conjuntos-T applied to the development of the competition of mathematical modeling In this article we want to present parts of the theory of joint-T and how it is applied in higher education to develop the competence of mathematical modeling subjects. We explain how the theory can develop the skills of students. This theory is a response to the problems of learning of mathematics that originate in the curriculum designed to acquire information and not only to develop the math skills of students. A teoria de Conjuntos-T aplicada ao desenvolvimento da concorrência  modelagem matemática Neste artigo, nos queremos apresentar algumas noções da teoria dos conjuntos-T e como ela é aplicada na docência, de ensino superior, para desenvolver a competência da modelagem matemática. Nos vamos explicar como a teoria pode desenvolver as habilidades dos alunos. Esta teoria é uma resposta para os problemas de ensino e aprendizagem da matemática que se originam nos programas curriculares destinados a adquirir somente informação e não para desenvolver as habilidades matemáticas dos alunos.

Solute transport and the prediction of breakaway oxidation in gamma + beta Ni-Cr-Al alloys

Science.gov (United States)

Nesbitt, J. A.; Heckel, R. W.

1984-01-01

The Al transport and the condition leading to breakaway oxidation during the cyclic oxidation of gamma + beta NiCrAl alloys have been studied. The Al concentration/distance profiles were measured after various cyclic oxidation exposures at 1200 C. It was observed that cyclic oxidation results in a decreasing Al concentration at the oxide/metal interface, maintaining a constant flux of Al to the Al2O3 scale. It was also observed that breakaway oxidation occurs when the Al concentration at the oxide/metal interface approaches zero. A numerical model was developed to simulate the diffusional transport of Al and to predict breakaway oxidation in gamma + beta NiCrAl alloys undergoing cyclic oxidation. In a comparison of two alloys with similar oxide spalling characteristics, the numerical model was shown to predict correctly the onset of breakaway oxidation in the higher Al-content alloy.

Current transport in graphene/AlGaN/GaN vertical heterostructures probed at nanoscale.

Science.gov (United States)

Fisichella, Gabriele; Greco, Giuseppe; Roccaforte, Fabrizio; Giannazzo, Filippo

2014-08-07

Vertical heterostructures combining two or more graphene (Gr) layers separated by ultra-thin insulating or semiconductor barriers represent very promising systems for next generation electronics devices, due to the combination of high speed operation with wide-range current modulation by a gate bias. They are based on the specific mechanisms of current transport between two-dimensional-electron-gases (2DEGs) in close proximity. In this context, vertical devices formed by Gr and semiconductor heterostructures hosting an "ordinary" 2DEG can be also very interesting. In this work, we investigated the vertical current transport in Gr/Al(0.25)Ga(0.75)N/GaN heterostructures, where Gr is separated from a high density 2DEG by a ∼ 24 nm thick AlGaN barrier layer. The current transport from Gr to the buried 2DEG was characterized at nanoscale using conductive atomic force microscopy (CAFM) and scanning capacitance microscopy (SCM). From these analyses, performed both on Gr/AlGaN/GaN and on AlGaN/GaN reference samples using AFM tips with different metal coatings, the Gr/AlGaN Schottky barrier height ΦB and its lateral uniformity were evaluated, as well as the variation of the carrier densities of graphene (ngr) and AlGaN/GaN 2DEG (ns) as a function of the applied bias. A low Schottky barrier (∼ 0.40 eV) with excellent spatial uniformity was found at the Gr/AlGaN interface, i.e., lower compared to the measured values for metal/AlGaN contacts, which range from ∼ 0.6 to ∼ 1.1 eV depending on the metal workfunction. The electrical behavior of the Gr/AlGaN contact has been explained by Gr interaction with AlGaN donor-like surface states located in close proximity, which are also responsible of high n-type Gr doping (∼ 1.3 × 10(13) cm(-2)). An effective modulation of ns by the Gr Schottky contact was demonstrated by capacitance analysis under reverse bias. From this basic understanding of transport properties in Gr/AlGaN/GaN heterostructures, novel vertical field effect

Gobernanza Pública y Gobernabilidad: Accountability y Disclosure posibilitadas por la Contabilidad Aplicada al Sector Público como Instrumento de Sostenibilidad del Estado

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Antonio Gonçalves Oliveira

2013-01-01

Full Text Available El Principio de la Continuidad en una visión contable-financiera aplicado a las organizaciones empresariales presupone su sostenibilidad en dirección a la perpetuidad, influenciando y asegurando a los inversores el retorno de sus inversiones. En la Administración Pública, no es diferente, destacándose la existencia del Principio de la Continuidad del Estado. Tal principio describe el Estado como sociedad política que, así como la empresa, debe ser perenne y sostenible visando siempre a la promoción del bien común y al desarrollo de su pueblo. Consonante a la contribución esperada, este trabajo tiene por objetivo discutir la importancia de la Contabilidad Aplicada al Sector Público como herramienta útil a la efectividad de la Gobernanza y de la Gobernabilidad Públicas adherentes a una visión de sostenibilidad aplicable a la gestión del Estado. La metodología adoptada, en relación a los fines, fue la pesquisa exploratoria y explicativa utilizando, en relación a los medios, de investigaciones bibliográficas y documental y de la observación teórico- empírica concernientes a la adherencia de la disclosure (transparencia y de la accountability (responsabilidad social de prestar cuentas a la sociedad a la Gestión Pública. Como resultados fue posible constatar una fuerte interrelación entre los términos, a la vista del hecho de que la Contabilidad evidencie los resultados y las acciones de los gobiernos a partir de la gobernanza (el medio/el cómo relacionada con la gobernabilidad (poder y acciones políticas, y también que ambas son orientadas para la sostenibilidad del Estado. Sobre la sostenibilidad del Estado, fue constatado asimismo que esta es de más alcance que el propio término “sostenibilidad”, el cual, en muchas veces, es reducido a la visión eco-ambiental y no considera importantes variables de cuño financiero (equilibrio y económico-social inherentes a la función social del Estado.

Gobernanza Pública y Gobernabilidad: Accountability y Disclosure posibilitadas por la Contabilidad Aplicada al Sector Público como Instrumento de Sostenibilidad del Estado

Directory of Open Access Journals (Sweden)

Antonio Gonçalves Oliveira

2013-03-01

Full Text Available El Principio de la Continuidad en una visión contable-financiera aplicado a las organizaciones empresariales presupone su sostenibilidad en dirección a la perpetuidad, influenciando y asegurando a los inversores el retorno de sus inversiones. En la Administración Pública, no es diferente, destacándose la existencia del Principio de la Continuidad del Estado. Tal principio describe el Estado como sociedad política que, así como la empresa, debe ser perenne y sostenible visando siempre a la promoción del bien común y al desarrollo de su pueblo. Consonante a la contribución esperada, este trabajo tiene por objetivo discutir la importancia de la Contabilidad Aplicada al Sector Público como herramienta útil a la efectividad de la Gobernanza y de la Gobernabilidad Públicas adherentes a una visión de sostenibilidad aplicable a la gestión del Estado. La metodología adoptada, en relación a los fines, fue la pesquisa exploratoria y explicativa utilizando, en relación a los medios, de investigaciones bibliográficas y documental y de la observación teóricoempírica concernientes a la adherencia de la disclosure (transparencia y de la accountability (responsabilidad social de prestar cuentas a la sociedad a la Gestión Pública. Como resultados fue posible constatar una fuerte interrelación entre los términos, a la vista del hecho de que la Contabilidad evidencie los resultados y las acciones de los gobiernos a partir de la gobernanza (el medio/el cómo relacionada con la gobernabilidad (poder y acciones políticas, y también que ambas son orientadas para la sostenibilidad del Estado. Sobre la sostenibilidad del Estado, fue constatado asimismo que esta es de más alcance que el propio término “sostenibilidad”, el cual, en muchas veces, es reducido a la visión eco-ambiental y no considera importantes variables de cuño financiero (equilibrio y económico-social inherentes a la función social del Estado

Electron transport in InAs/AlGaSb ballistic rectifiers

International Nuclear Information System (INIS)

Maemoto, Toshihiko; Koyama, Masatoshi; Furukawa, Masashi; Takahashi, Hiroshi; Sasa, Shigehiko; Inoue, Masataka

2006-01-01

Nonlinear transport properties of a ballistic rectifier fabricated from InAs/AlGaSb heterostructures are reported. The operation of the ballistic rectifier is based on the guidance of carriers by a square anti-dot structure. The structure was defined by electron beam lithography and wet chemical etching. The DC characteristics and magneto-transport properties of the ballistic rectifier have been measured at 77 K and 4.2 K. Rectification effects relying on the ballistic transport were observed. From the four-terminal resistance measured at low magnetic fields, we also observed magneto-resistance fluctuations corresponding to the electron trajectories and symmetry-breaking electron scattering, which are influenced by the magnetic field strength

Bordieu e a lingüística aplicada

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Maria de Lourdes Otero Brabo Cruz

2001-02-01

Full Text Available

Procura-se no presente trabalho: (a analisar as concepções de Bourdieu no que diz respeito à competência lingüística e ao tratamento dos fatos lingüísticos; (b traçar um paralelo entre essas concepções e a lingüística aplicada; e (c definir a sua postura como sendo a de um lingüista aplicado.

Bordieu e a lingüística aplicada

OpenAIRE

Maria de Lourdes Otero Brabo Cruz

2001-01-01

Procura-se no presente trabalho: (a) analisar as concepções de Bourdieu no que diz respeito à competência lingüística e ao tratamento dos fatos lingüísticos; (b) traçar um paralelo entre essas concepções e a lingüística aplicada; e (c) definir a sua postura como sendo a de um lingüista aplicado.

Probabilidade e Estatística Aplicada à Hidrologia

OpenAIRE

Guimarães, Rita Cabral

2011-01-01

Esta pubilicação pretende ser um manual de auxilio aos alunos na disciplinas de Hidrologia, Hidrologia Agrícola e Interpretação da Paisagem na área da probabilidade e estatistica aplicada à Hidrologia. Abordam-se temas básicos da teoria da estatística e da probabilidade para depois estes serema aplicados na resolução de problemas ligados à Hidrologia

TRANSPORTE COOPERATIVO DE OBJETOS CON UNA PLATAFORMA MÓVIL EN UN ENTORNO ESTRUCTURADO

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Edwin Andres Beltran Gonzalez

2012-08-01

Full Text Available La robótica cooperativa busca diseñar sistemas compuestos de varios robots capaces de resolver problemas conjuntamente, de tal manera que dicha implementación puede llevar consigo distintos tipos de control (centralizado o distribuido, de esta manera una de las aplicaciones en esta línea de investigación es el transporte de objetos mediante distintas estrategias que van desde el empuje, la sujeción y arrastre de los objetos; tales trabajos se han presentado desde la década de los 90 hasta el día de hoy. El enfoque del presente artículo busca mostrar el desarrollo e implementación de una plataforma robótica cooperativa aplicada al transporte de objetos largos a través de un entorno estructurado utilizando las herramientas que provee el kit Lego Mindstorms RCX 2.0 y el grupo de investigación en robótica móvil autónoma ROMA.

Limitaciones del Transporte Aerocomercial al desarrollo del turismo. Análisis de caso: transporte interno en Argentina

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MG. Noemí Wallingre

2009-11-01

Full Text Available Desde sus orígenes el transporte aéreo fue fundamental para el impulso del turismo siendo sus avances en muchos países de forma interdependiente. Aparentemente, no es el caso argentino a pesar de la contribución que esa modalidad del transporte, representa para el sector turismo. En 1989 Argentina aprobó una Reforma del Estado que produjo importantes transformaciones que afectaron tanto al transporte aéreo como al turismo. Este artículo analizará esas transformaciones y el impacto que produjeron sobre la oferta y la demanda del transporte aéreo interno; así como sobre la relación entre el crecimiento de la demanda turística, la participación del turismo sobre los ingresos y el empleo, el incremento del alojamiento y el transporte aerocomercial. Para el transporte aerocomercial interno se analizará la variación en la cantidad de vuelos semanales, empresas, flotas y en el tráfico regular de pasajeros El estudio se extenderá entre 1990-2007. Se procurará demostrar las limitaciones que sobre el desarrollo del turismo puede producir la ausencia de políticas para el crecimiento del transporte aerocomercial interno. En síntesis, el trabajo se propone los siguientes objetivos: – Presentar las transformaciones desde la implementación de la Reforma del Estado argentino en el transporte aerocomercial interno y el turismo. – Indagar sobre la relación existente entre el crecimiento de los movimientos turísticos, la oferta de alojamiento y el transporte aéreo, y de la participación del turismo sobre los ingresos por exportación. Reflexionar sobre el impacto en el desarrollo del turismo de la falta de políticas en el transporte aéreo interno, y en la coordinación entre ambos sectores.

Calidad del transporte neonatal en el Valle del Cauca: un reto para salud

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Luis Alexander Lovera Montilla

2014-01-01

Full Text Available Introducción: El transporte neonatal es un procedimiento que involucra la exposición al riesgo dependiendo de la complejidad de la patología y de la calidad con que se efectúe. Este estudio pretende evaluar la seguridad en el transporte a recién nacidos que ingresan a una unidad neonatal como un atributo de calidad. Materiales y Métodos: Estudio descriptivo transversal que utilizó un muestreo por conveniencia. La representatividad se determinó de manera subjetiva evaluando el proceso de transporte, recursos humanos, recursos técnicos e insumos. La información se obtuvo de dos fuentes: a Encuesta aplicada a los pediatras asistenciales de la unidad neonatal para conocer su percepción sobre la seguridad del transporte; b Instrumento aplicado al personal profesional y técnico que acompañó 118 transportes. Resultados: De los 118 transportes, el 46% fue realizado por paramédicos; el 76%, en Unidades de Transporte Asistencial Básico (TAB, sólo el 33% del personal responsable de la atención del recién nacido tiene entrenamiento neonatal; el 82% de estos transportes no llevó registro de signos vitales, ni de otras variables fisiológicas requeridas para valorar el estado clínico del neonato durante el traslado; el 76% no verificó la lista de chequeo de insumos y de materiales previo a cada remisión desconociendo su importancia. Por consiguiente, se incrementó el riesgo en la atención, impactando negativamente la calidad del procedimiento. Discusión y Conclusiones: Las instituciones de salud que ofrecen transporte neonatal deben garantizar que todos los neonatos que requieran el servicio lo obtengan en condiciones de calidad y equidad, que minimicen los factores de riesgo y posibiliten la supervivencia en las instituciones receptoras.

27Al, 63Cu NMR spectroscopy and electrical transport in Heusler Cu-Mn-Al alloy powders

Science.gov (United States)

Nadutov, V. M.; Perekos, A. O.; Kokorin, V. V.; Trachevskii, V. V.; Konoplyuk, S. M.; Vashchuk, D. L.

2018-02-01

The ultrafine powder of the Heusler Cu-13,1Mn-12,6Al (wt.%) alloy produced by electrical spark dispersion (ESD) in ethanol and the pellets prepared by pressing of the powders and aged in various gas environment (air, Ar, vacuum) were studied by XRD, nuclear magnetic resonance, magnetic and electric transport methods. The constituent phases were identified as b.c.c. α-Cu-Mn-Al, f.c.c. γ-Cu-Mn-Al, Cu2MnAl, and oxides. The sizes of the coherently scattering domains (CSD) and the saturation magnetizations were in the range of 4-90 nm and 0-1.5 Am2/kg, respectively. 27Al and 63Cu NMR spectra of the powders and pellets have shown hyperfine structure caused by contributions from atomic nuclei of the constituent phases. The aging of pellets in different gas environments had effect on their phase composition but no effect on dispersion of the phases. In contrast to the as-cast alloy, electrical resistance of the pellets evidenced semiconducting behavior at elevated temperatures due to the presence of metal oxides formed on the surfaces of nanoparticles.

Inteligência Competitiva: metodologias aplicadas em empresas brasileiras
Inteligencia Competitiva: metodologías aplicadas en las empresas brasileñas

OpenAIRE

Mônica Erichsen Nassif; Frederico Vidigal

2012-01-01

Introdução: Apresenta um panorama acerca da Inteligência Competitiva no contexto das organizações brasileiras. Objetivo: Investiga a existência de metodologias de Inteligência Competitiva aplicadas a organizações nacionais e multinacionais de diferentes segmentos de mercado. Metodologia: Revisão de literatura nacional e internacional – envolvendo o status quo da atividade de Inteligência Competitiva no mundo – e cujo conteúdo foi confrontado com os resultados obtidos em entrevistas realiza...

Optimizing SuperCDMS phonon energy sensitivity by studying quasiparticle transport in Al films

Science.gov (United States)

Yen, Jeffrey; Shank, Benjamin; Cabrera, Blas; Moffatt, Robert; Redl, Peter; Brink, Paul; Tomada, Astrid; Cherry, Matt; Young, Betty; Tortorici, Teddy; Kreikebaum, John Mark

2014-03-01

In order to further improve the phonon energy sensitivity of Cryogenic Dark Matter Search (CDMS) detectors, we studied quasiparticle transport at ~ 40 mK in superconducting Al films similar in geometry to those used for CDMS detectors. Test structures of Al were deposited and photolithographically patterned on Si wafers using the same production-line equipment used to fabricate kg-scale CDMS detectors. Three Al film lengths and two film thicknesses were used in this study. In the test experiments described here, an 55Fe source was used to excite a NaCl reflector, producing 2.6 keV x-rays that hit our test devices after passing through a collimator. The impinging x-rays broke Cooper pairs in the Al films, producing quasiparticles that propagated into W transition edge sensors (TESs) coupled to the ends of the Al films. In this talk, we will give the motivation behind these studies, describe our experimental setup, and compare our data to results obtained using signal processing models constructed from basic physical parameters. We show that a non-linear, non-stationary optimal filter applied to the data allows us to precisely measure quasiparticle diffusion and other aspects of energy transport in our thin-film Al-W test devices. These results are being used to further optimize next-generation CDMS detectors.

Using Mosaicity to Tune Thermal Transport in Polycrystalline AlN Thin Films

KAUST Repository

Singh, Shivkant

2018-05-17

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 W/mK vs. 8.09 W/mK are measured for samples with tilt angles of 10° vs. 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

Using Mosaicity to Tune Thermal Transport in Polycrystalline AlN Thin Films

KAUST Repository

Singh, Shivkant; Shervin, Shahab; Sun, Haiding; Yarali, Milad; Chen, Jie; Lin, Ronghui; Li, Kuang-Hui; Li, Xiaohang; Ryou, Jae-Hyun; Mavrokefalos, Anastassios

2018-01-01

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 W/mK vs. 8.09 W/mK are measured for samples with tilt angles of 10° vs. 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

Diseño instruccional constructivista de la asignatura “las TIC aplicadas a la educación” para la licenciatura en Educación mención Preescolar de la UNA /

Directory of Open Access Journals (Sweden)

Sorel Andreina Hernández Luque

2015-07-01

Full Text Available En este artículo, se presenta el diseño instruccional constructivista de la Asignatura “Las TIC aplicadas a la Educación” la cual servirá como un aporte a la mejora del currículo para el Pensum de la Licenciatura en Educación Preescolar de la UNA, buscando responder a las debilidades detectadas en los estudiantes frente al uso de las TIC.

Desenvolvimento de uma rede de sensores sem fio aplicada no monitoramento da variabilidade térmica em casas de vegetação

OpenAIRE

Barbosa, Rogério Zanarde [UNESP

2015-01-01

Este é um trabalho de tecnologia computacional aplicada na área agrícola, cujo objetivo principal do trabalho é desenvolver uma rede de sensores sem fio, que envolve aspectos de software e hardware, para o monitoramento térmico no interior de uma casa de vegetação. Além da rede propriamente dita, o trabalho também inclui a sua aplicação no levantamento quantitativo da variabilidade térmica na casa de vegetação o que pode ser aplicado em diversas atividades agrícolas a serem desenvolvidas no i...

Effect of spin reorientation on magnetocaloric and transport properties of NdAl{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Souza, M.V. de, E-mail: marcos_vinicios@hotmail.com [Núcleo de Pós-Graduação em Física, Campus Prof. José Aloísio de Campos, UFS, 49100-000 São Cristóvão, SE (Brazil); Silva, J.A. da [Núcleo de Pós-Graduação em Física, Campus Prof. José Aloísio de Campos, UFS, 49100-000 São Cristóvão, SE (Brazil); Silva, L.S. [Núcleo de Pós-Graduação em Física, Campus Prof. José Aloísio de Campos, UFS, 49100-000 São Cristóvão, SE (Brazil); Instituto Federal de Tocantins, IFTO – Campus Colinas do Tocantins, AV. Bernardo Sayao S/N, Chácara Raio de Sol, Setor Santa Maria, CEP 77760-000 Colinas do Tocantins, TO (Brazil)

2017-01-01

We report the magneto-thermal and resistive properties of rare-earth dialuminide NdAl{sub 2}, including spin reorientation transition. To this purpose, we used a theoretical model that considers the interactions of exchange and Zeeman, besides the anisotropy due to the electrical crystal field. The theoretical results obtained were compared to experimental data of the NdAl{sub 2} in single crystal and bulk forms. Explicitly, we have calculated the anisotropic variation of magnetic entropy with the magnetic field oriented along the three principal crystallographic directions: [100], [110], and [111] of NdAl{sub 2} single crystal, where a signature of the spin reorientation is observed in the [110] and [111] directions. Moreover, of magnetoresistivity we consider the applied magnetic field along the crystallographic directions [100] and [110]. In turn, for the polycrystalline form, the good agreement between theory and experiment confirms the presence of spin reorientation, which was predicted theoretically in magnetization curves. - Highlights: • Modeling of the thermodynamics quantities in NdAl{sub 2} single crystal and policrystal. • Modeling of the transport properties in NdAl{sub 2} single crystal. • Effect of reorientation of spin on caloric and transport properties.

Phase-coherent electron transport in (Zn, Al)Ox thin films grown by atomic layer deposition

Science.gov (United States)

Saha, D.; Misra, P.; Ajimsha, R. S.; Joshi, M. P.; Kukreja, L. M.

2014-11-01

A clear signature of disorder induced quantum-interference phenomena leading to phase-coherent electron transport was observed in (Zn, Al)Ox thin films grown by atomic layer deposition. The degree of static-disorder was tuned by varying the Al concentration through periodic incorporation of Al2O3 sub-monolayer in ZnO. All the films showed small negative magnetoresistance due to magnetic field suppressed weak-localization effect. The temperature dependence of phase-coherence length ( l φ ∝ T - 3 / 4 ), as extracted from the magnetoresistance measurements, indicated electron-electron scattering as the dominant dephasing mechanism. The persistence of quantum-interference at relatively higher temperatures up to 200 K is promising for the realization of ZnO based phase-coherent electron transport devices.

Electromigration-induced drift in damascene and plasma-etched Al(Cu). II. Mass transport mechanisms in bamboo interconnects

Science.gov (United States)

Proost, Joris; Maex, Karen; Delacy, Luc

2000-01-01

We have discussed electromigration (EM)-induced drift in polycrystalline damascene versus reactive ion etched (RIE) Al(Cu) in part I. For polycrystalline Al(Cu), mass transport is well documented to occur through sequential stages : an incubation period (attributed to Cu depletion beyond a critical length) followed by the Al drift stage. In this work, the drift behavior of bamboo RIE and damascene Al(Cu) is analyzed. Using Blech-type test structures, mass transport in RIE lines was shown to proceed both by lattice and interfacial diffusion. The dominating mechanism depends on the Cu distribution in the line, as was evidenced by comparing as-patterned (lattice EM) and RTP-annealed (interface EM) samples. The interfacial EM only occurs at metallic interfaces. In that case, Cu alloying was observed to retard Al interfacial mass transport, giving rise to an incubation time. Although the activation energy for the incubation time was found similar to the one controlling Al lattice drift, for which no incubation time was observed, lattice EM is preferred over interfacial EM because it is insensitive to enhancing geometrical effects upon scaling. When comparing interfacial electromigration in RIE with bamboo damascene Al(Cu), with the incubation time rate controlling for both, the higher EM threshold observed for damascene was shown to be insufficient to compensate for its significantly increased Cu depletion rate, contrary to the case of polycrystalline Al(Cu) interconnects. Two factors were demonstrated to contribute. First, there are more metallic interfaces, intrinsically related to the use of wetting or barrier layers in recessed features. Second, specific to this study, the additional formation of TiAl3 at the trench sidewalls further enhanced the Cu depletion rate, and reduced the rate-controlling incubation time. A separate drift study on RIE via-type test structures indicated that it is very difficult to suppress interfacial mass transport in favor of lattice EM

Reconstrucción del maxilar superior mediante transporte del proceso alveolar: Presentación de un caso Reconstruction of the maxilla by means of transport of the alveolar process: A case report

Directory of Open Access Journals (Sweden)

A. Bilbao

2006-02-01

Full Text Available La osteogénesis mediante distracción aplicada a la reconstrucción del proceso alveolar es una técnica sobradamente contrastada en la literatura, al igual que la utilización del transporte óseo en la reconstrucción de defectos segmentarios mandibulares. Presentamos en este artículo un caso de reconstrucción de un defecto segmentario del maxilar superior mediante transporte de proceso alveolar y su posterior rehabilitación protésica implantosoportada. Mostramos tanto la técnica quirúrgica como el manejo de del vector de distracción utilizando elásticos de ortodoncia y tornillos de bloqueo intermaxilar.Osteogenesis by means of distraction applied to the reconstruction of the alveolar process is a well-documented technique in the literature, as is the use of bone transport in the reconstruction of mandibular segment defects. In the present article we report on a case of reconstruction of a segment defect in the maxilla using the alveolar transport process, and on the subsequent rehabilitation by means of an implant-supported prosthesis. Both the surgical technique and the handling of the distraction vector using orthodontic bands and inter-maxillary fixation screws are shown.

Decay Lengths for Diffusive Transport Activated by Andreev Reflections in Al/n-GaAs/Al Superconductor-Semiconductor-Superconductor Junctions

DEFF Research Database (Denmark)

Kutchinsky, Jonatan; Taboryski, Rafael Jozef; Clausen, Thomas

1997-01-01

In a highly doped GaAs semiconductor with superconducting contacts of Al, clear conductance peaks are observed at zero voltage bias and at V = +/-2 Delta/e, +/-Delta/e. The subharmonic energy gap structure originates from Andreev scattering with diffusive, but energy conserving, transport in the ...

BoALMT1, an Al-Induced Malate Transporter in Cabbage, Enhances Aluminum Tolerance in Arabidopsis thaliana

Directory of Open Access Journals (Sweden)

Lei Zhang

2018-01-01

Full Text Available Aluminum (Al is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104 was cloned from cabbage (Brassica oleracea. BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent cations lanthanum (La, cadmium (Cd, zinc (Zn, or copper (Cu. Subcellular localization studies were performed in onion epidermal cells and revealed that BoALMT1 was localized at the plasma membrane. Scanning Ion-selective Electrode Technique was used to analyze H+ flux. Xenopus oocytes and Arabidopsis thaliana expressing BoALMT1 excreted more H+ under Al treatment. Overexpressing BoALMT1 in transgenic Arabidopsis resulted in enhanced Al tolerance and increased malate secretion. The results suggested that BoALMT1 functions as an Al-resistant gene and encodes a malate transporter. Expressing BoALMT1 in Xenopus oocytes or A. thaliana indicated that BoALMT1 could increase malate secretion and H+ efflux to resist Al tolerance.

CONTAINMENT EVALUATION OF BREACHED AL-SNF FOR CASK TRANSPORT

International Nuclear Information System (INIS)

Vinson, D. W.; Sindelar, R. L.; Iyer, N. C.

2005-01-01

Aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors (FRR/DRR) is being shipped to the Savannah River Site. To enter the U.S., the cask with loaded fuel must be certified to comply with the requirements in the Title 10 of the U.S. Code of Federal Regulations, Part 71. The requirements include demonstration of containment of the cask with its contents under normal and accident conditions. Al-SNF is subject to corrosion degradation in water storage, and many of the fuel assemblies are ''failed'' or have through-clad damage. A methodology has been developed with technical bases to show that Al-SNF with cladding breaches can be directly transported in standard casks and maintained within the allowable release rates. The approach to evaluate the limiting allowable leakage rate, L R , for a cask with breached Al-SNF for comparison to its test leakage rate could be extended to other nuclear material systems. The approach for containment analysis of Al-SNF follows calculations for commercial spent fuel as provided in NUREG/CR-6487 that adopts ANSI N14.5 as a methodology for containment analysis. The material-specific features and characteristics of damaged Al-SNF (fuel materials, fabrication techniques, microstructure, radionuclide inventory, and vapor corrosion rates) that were derived from literature sources and/or developed in laboratory testing are applied to generate the four containment source terms that yield four separate cask cavity activity densities; namely, those from fines; gaseous fission product species; volatile fission product species; and fuel assembly crud. The activity values, A 2 , are developed per the guidance of 10CFR71. The analysis is performed parametrically to evaluate maximum number of breached assemblies and exposed fuel area for a proposed shipment in a cask with a test leakage rate

Characteristics study of 2DEG transport properties of AlGaN/GaN and AlGaAs/GaAs-based HEMT

International Nuclear Information System (INIS)

Lenka, T. R.; Panda, A. K.

2011-01-01

Growth of wide bandgap material over narrow bandgap material, results into a two dimensional electron gas (2DEG) at the heterointerface due to the conduction band discontinuity. In this paper the 2DEG transport properties of AlGaN/GaN-based high electron mobility transistor (HEMT) is discussed and its effect on various characteristics such as 2DEG density, C-V characteristics and Sheet resistances for different mole fractions are presented. The obtained results are also compared with AlGaAs/GaAs-based HEMT for the same structural parameter as like AlGaN/GaN-based HEMT. The calculated results of electron sheet concentration as a function of the Al mole fraction are in excellent agreement with some experimental data available in the literature.

Effect of Al2Cu precipitates size and mass transport on the polarisation behaviour of age-hardened Al-Si-Cu-Mg alloys in 0.05 M NaCl

International Nuclear Information System (INIS)

Vieira, A.C.; Pinto, A.M.; Rocha, L.A.; Mischler, S.

2011-01-01

Research highlights: → Influence of the size distribution of Al-Cu phases on the electrochemical behaviour of well defined alloys under controlled mass transport conditions (RDE). → Oxygen reduction occurs only the Al 2 Cu phases. → Thinner Al-Cu grains the oxygen reduction current deviates at high rotation rates from the Levich behaviour. - Abstract: The electrochemical behaviour of age-hardened Al-Si-Cu-Mg alloys was investigated in a 0.05 M NaCl solution under controlled mass transport conditions using a rotating disk electrode. This work aimed at getting better understanding of the effect of the alloy microstructure, in particular the size distribution of Al 2 Cu phase, on the corrosion behaviour of the alloy. Three different size distributions of the Al 2 Cu phase were obtained through appropriate heat treatments. The cathodic reduction of oxygen was found to occur mainly on the Al 2 Cu phases acting as preferential cathodes. Small sized Al 2 Cu phases were found to promote at high rotation rates a transition from a 4 electron to a 2 electron dominated oxygen reduction mechanisms.

Nanoscale Titanium Dioxide (nTiO2) Transport in Water-Saturated Natural Sediments: Influence of Soil Organic Matter and Fe/Al Oxyhydroxides

Science.gov (United States)

Fisher-Power, L.; Cheng, T.

2017-12-01

Transport of engineered nanoparticles (ENP) in subsurface environments has important implications to water quality and soil contamination. Although extensive research has been conducted to understand the effects of water chemistry on ENP transport, less attention has been paid to influences from the transport medium/matrix. The objective of this research is to investigate the effects of natural organic matter (NOM) and Fe/Al oxyhydroxides in a natural sediment on ENP transport. A sediment was collected and separated into four portions, one of which was unmodified, and the others treated to remove specific components (organic matter, Fe/Al oxyhydroxides, or both organic matter and Fe/Al oxyhydroxides). Transport of nanoscale titanium dioxide (nTiO2) in columns packed with quartz sand and each of the four types of the sediment under water-saturated conditions was studied. Our results showed that nTiO2 transport was strongly influenced by pH and sediment composition. When influent pH = 5, nTiO2 transport in all the sediments was low, as positively-charged nTiO2 was attracted to negatively charged NOM, quartz, and other minerals. nTiO2 transport was slightly enhanced in columns packed with untreated sediment or Fe/Al oxyhydroxides removed sediment due to dissolved organic matter generated by the partial dissolution of NOM, which adsorbed onto nTiO2 surface and reversed its zeta potential to negative. When influent pH = 9, nTiO2 transport was generally high since negatively-charged nTiO2 was repelled by negatively charged transport medium. However, in columns packed with the organic matter removed sediment or the Fe/Al oxyhydroxides removed sediment, nTiO2 transport was low. This was attributable to pH buffering by the sediment, which decreased pore water pH in the column, resulting in zeta potential change and electrostatic attraction between Fe/Al oxyhydroxides and nTiO2. This research demonstrates that electrostatic forces between nTiO2 and mineral/organic components

BoALMT1, an Al-Induced Malate Transporter in Cabbage, Enhances Aluminum Tolerance in Arabidopsis thaliana

OpenAIRE

Zhang, Lei; Wu, Xin-Xin; Wang, Jinfang; Qi, Chuandong; Wang, Xiaoyun; Wang, Gongle; Li, Mingyue; Li, Xingsheng; Guo, Yang-Dong

2018-01-01

Aluminum (Al) is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104) was cloned from cabbage (Brassica oleracea). BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent catio...

Effect of Al and Fe doping in ZnO on magnetic and magneto-transport properties

International Nuclear Information System (INIS)

Kumar, Santosh; Deepika; Tripathi, Malvika; Vaibhav, Pratyush; Kumar, Aman; Kumar, Ritesh; Choudhary, R.J.; Phase, D.M.

2016-01-01

The structural, magnetic and magneto-transport of undoped ZnO, Zn_0_._9_7Al_0_._0_3O, Zn_0_._9_5Fe_0_._0_5O and Zn_0_._9_2Al_0_._0_3Fe_0_._0_5O thin films grown on Si(100) substrate using pulsed laser deposition were investigated. The single phase nature of the films is confirmed by X-ray diffraction and Raman spectroscopy measurements. The possibility of Fe metal cluster in Fe doped/co-doped films is ruled out by Fe 2p core level photoelectron spectra. From O 1s core level spectra it is observed that oxygen vacancy is present in all the films. The undoped ZnO film shows magnetic ordering below ∼175 K, whereas Fe doped/codoped samples show magnetic ordering even at 300 K. The Al doped sample reveals paramagnetic behavior. The magneto-transport measurements suggest that the mobile carriers undergo exchange interaction with local magnetic moments. - Highlights: • Al, Fe, Al–Fe co-doped and undoped films of ZnO are deposited on Si by PLD. • Single phase (002) oriented Wurtzite ZnO phase is formed for all films. • Fe doped and Fe–Al co-doped ZnO films reveal magnetic hysteresis at 300 K. • Negative magnetoresistance is observed in undoped and Fe–Al co-doped ZnO film. • It is apparent that charge carriers are coupled with the local magnetic moment.

Effect of Al and Fe doping in ZnO on magnetic and magneto-transport properties

Energy Technology Data Exchange (ETDEWEB)

Kumar, Santosh, E-mail: skphysics@yahoo.co.in [Department of Physics, College of Commerce, Arts & Science, Patna 800020, Bihar (India); Deepika [Department of Physics, College of Commerce, Arts & Science, Patna 800020, Bihar (India); Tripathi, Malvika [UGC DAE, Consortium for scientific research, Indore 452001, Madhya Pradesh (India); Vaibhav, Pratyush [Jaypee University of Engineering and Technology, Guna 473226, Madhya Pradesh (India); Kumar, Aman [Indian Institute of Technology, Roorkee (India); Kumar, Ritesh [Department of Physics, College of Commerce, Arts & Science, Patna 800020, Bihar (India); Choudhary, R.J., E-mail: ram@csr.res.in [UGC DAE, Consortium for scientific research, Indore 452001, Madhya Pradesh (India); Phase, D.M. [UGC DAE, Consortium for scientific research, Indore 452001, Madhya Pradesh (India)

2016-12-01

The structural, magnetic and magneto-transport of undoped ZnO, Zn{sub 0.97}Al{sub 0.03}O, Zn{sub 0.95}Fe{sub 0.05}O and Zn{sub 0.92}Al{sub 0.03}Fe{sub 0.05}O thin films grown on Si(100) substrate using pulsed laser deposition were investigated. The single phase nature of the films is confirmed by X-ray diffraction and Raman spectroscopy measurements. The possibility of Fe metal cluster in Fe doped/co-doped films is ruled out by Fe 2p core level photoelectron spectra. From O 1s core level spectra it is observed that oxygen vacancy is present in all the films. The undoped ZnO film shows magnetic ordering below ∼175 K, whereas Fe doped/codoped samples show magnetic ordering even at 300 K. The Al doped sample reveals paramagnetic behavior. The magneto-transport measurements suggest that the mobile carriers undergo exchange interaction with local magnetic moments. - Highlights: • Al, Fe, Al–Fe co-doped and undoped films of ZnO are deposited on Si by PLD. • Single phase (002) oriented Wurtzite ZnO phase is formed for all films. • Fe doped and Fe–Al co-doped ZnO films reveal magnetic hysteresis at 300 K. • Negative magnetoresistance is observed in undoped and Fe–Al co-doped ZnO film. • It is apparent that charge carriers are coupled with the local magnetic moment.

Predicción científica y prescripción en mejora genética vegetal en cuanto Ciencia Aplicada de Diseño: El caso de la mejora de frutales del género Prunus

Directory of Open Access Journals (Sweden)

Pedro Martínez-Gómez

2017-01-01

Full Text Available La mejora genética vegetal tiene una doble índole científica: Ciencia Empírica de la Naturaleza y Ciencia Aplicada de Diseño. En este contexto el presente trabajo pretende indagar en la predicción científica como rasgo esencial de esta disciplina en cuanto Ciencia Aplicada de Diseño con especial referencia la mejora de frutales de hueso (del género Prunus. En mejora genética vegetal podemos hablar de tres niveles de conocimiento asociados a la biología molecular (nivel micro, la constitución genética de un individuo (nivel meso y al fenotipo o aspecto global de la nueva variedad (nivel macro, que afectan tanto a los tipos de predicción como a las metodologías a aplicar. La predicción constituye el objetivo principal de la mejora genética como Ciencia de Diseño. Es clave tener un conocimiento del futuro posible para poder hacer un nuevo diseño que estará completo al cabo de algunos años, más de 12 años en el caso de los frutales de hueso que es el objeto de este trabajo. Asimismo, es necesario tener en cuenta en el desarrollo de esta predicción científica aplicada a la mejora de Prunus diversas variables internas (la naturaleza genética del material vegetal de partida, las metodologías disponibles, etc. y externas (la aceptación social, los factores medioambientales, los estreses bióticos y abióticos, etc. a la hora de llevar a cabo esta predicción. El grado de conocimiento de estas variables determinará la calidad de la predicción en el diseño de nuevas variedades de Prunus.

MINERAÇÃO DE DADOS APLICADA A RELAÇÃO CLIENTES E PAGAMENTOS – ESTUDO BIBLIOMÉTRICO

Directory of Open Access Journals (Sweden)

Alcione Dias Silva

2013-03-01

Full Text Available O KDD (Knowledge Discovery in Database e a Mineração de Dados incluem tarefas e métodos para extração de conhecimento útil, interessante e indispensável na tomada de decisões rápidas nas mais diversas áreas de conhecimento. Esta pesquisa tem como objetivo nortear o leitor na vasta relação de trabalhos que se utilizam desta importante ferramenta e apontar as principais publicações de Mineração de Dados utilizadas na relação clientes e pagamentos, no âmbito público e privado, além de propor chaves de pesquisa que possam contribuir para a obtenção de trabalhos relacionados com objetivo de facilitar as buscas pertinentes a este importante assunto. Quanto à metodologia, foram pesquisadas as publicações relacionadas às técnicas de Mineração de Dados aplicadas a base de dados tributária pertencente a entidades governamentais estendendo-se analogamente aos trabalhos similares na área privada. A base de dados utilizada para este estudo foi a SCOPUS no período de janeiro de 1999 a março de 2012. Dentre os 927 resultados obtidos, tem merecido destaque o setor de pagamentos eletrônicos via cartões de crédito e a rede neural artificial como técnica aplicada com maior sucesso. O idioma mais utilizado para a confecção das publicações foi o inglês. Os resultados apresentados contribuem no sentido de direcionar os autores quanto às áreas mais carentes de trabalhos científicos aplicados a Mineração de Dados, os países e idiomas com maior número de publicações, contribuindo de forma direcionada para o enriquecimento de trabalhos futuros.

Effects of the strain relaxation of an AlGaN barrier layer induced by various cap layers on the transport properties in AlGaN/GaN heterostructures

International Nuclear Information System (INIS)

Liu Zi-Yang; Zhang Jin-Cheng; Duan Huan-Tao; Xue Jun-Shuai; Lin Zhi-Yu; Ma Jun-Cai; Xue Xiao-Yong; Hao Yue

2011-01-01

The strain relaxation of an AlGaN barrier layer may be influenced by a thin cap layer above, and affects the transport properties of AlGaN/GaN heterostructures. Compared with the slight strain relaxation found in AlGaN barrier layer without cap layer, it is found that a thin cap layer can induce considerable changes of strain state in the AlGaN barrier layer. The degree of relaxation of the AlGaN layer significantly influences the transport properties of the two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructures. It is observed that electron mobility decreases with the increasing degree of relaxation of the AlGaN barrier, which is believed to be the main cause of the deterioration of crystalline quality and morphology on the AlGaN/GaN interface. On the other hand, both GaN and AlN cap layers lead to a decrease in 2DEG density. The reduction of 2DEG caused by the GaN cap layer may be attributed to the additional negative polarization charges formed at the interface between GaN and AlGaN, while the reduction of the piezoelectric effect in the AlGaN layer results in the decrease of 2DEG density in the case of AlN cap layer. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Functional, structural and phylogenetic analysis of domains underlying the Al sensitivity of the aluminum-activated malate/anion transporter, TaALMT1.

Science.gov (United States)

Ligaba, Ayalew; Dreyer, Ingo; Margaryan, Armine; Schneider, David J; Kochian, Leon; Piñeros, Miguel

2013-12-01

Triticum aestivum aluminum-activated malate transporter (TaALMT1) is the founding member of a unique gene family of anion transporters (ALMTs) that mediate the efflux of organic acids. A small sub-group of root-localized ALMTs, including TaALMT1, is physiologically associated with in planta aluminum (Al) resistance. TaALMT1 exhibits significant enhancement of transport activity in response to extracellular Al. In this study, we integrated structure-function analyses of structurally altered TaALMT1 proteins expressed in Xenopus oocytes with phylogenic analyses of the ALMT family. Our aim is to re-examine the role of protein domains in terms of their potential involvement in the Al-dependent enhancement (i.e. Al-responsiveness) of TaALMT1 transport activity, as well as the roles of all its 43 negatively charged amino acid residues. Our results indicate that the N-domain, which is predicted to form the conductive pathway, mediates ion transport even in the absence of the C-domain. However, segments in both domains are involved in Al(3+) sensing. We identified two regions, one at the N-terminus and a hydrophobic region at the C-terminus, that jointly contribute to the Al-response phenotype. Interestingly, the characteristic motif at the N-terminus appears to be specific for Al-responsive ALMTs. Our study highlights the need to include a comprehensive phylogenetic analysis when drawing inferences from structure-function analyses, as a significant proportion of the functional changes observed for TaALMT1 are most likely the result of alterations in the overall structural integrity of ALMT family proteins rather than modifications of specific sites involved in Al(3+) sensing. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Phase-coherent electron transport in (Zn, Al)O{sub x} thin films grown by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Ajimsha, R. S.; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2014-11-24

A clear signature of disorder induced quantum-interference phenomena leading to phase-coherent electron transport was observed in (Zn, Al)O{sub x} thin films grown by atomic layer deposition. The degree of static-disorder was tuned by varying the Al concentration through periodic incorporation of Al{sub 2}O{sub 3} sub-monolayer in ZnO. All the films showed small negative magnetoresistance due to magnetic field suppressed weak-localization effect. The temperature dependence of phase-coherence length (l{sub φ}∝T{sup −3/4}), as extracted from the magnetoresistance measurements, indicated electron-electron scattering as the dominant dephasing mechanism. The persistence of quantum-interference at relatively higher temperatures up to 200 K is promising for the realization of ZnO based phase-coherent electron transport devices.

Axonal transport of TDP-43 mRNA granules in neurons is impaired by ALS-causing mutations

Science.gov (United States)

Carrasco, Monica A.; Williams, Luis A.; Winborn, Christina S.; Han, Steve S. W.; Kiskinis, Evangelos; Winborn, Brett; Freibaum, Brian D.; Kanagaraj, Anderson; Clare, Alison J.; Badders, Nisha M.; Bilican, Bilada; Chaum, Edward; Chandran, Siddharthan; Shaw, Christopher E.; Eggan, Kevin C.; Maniatis, Tom; Taylor, J. Paul

2014-01-01

Summary The RNA binding protein TDP-43 regulates RNA metabolism at multiple levels, including transcription, RNA splicing, and mRNA stability. TDP-43 is a major component of the cytoplasmic inclusions characteristic of amyotrophic lateral sclerosis and some types of frontotemporal lobar degeneration. The importance of TDP-43 in disease is underscored by the fact that dominant missense mutations are sufficient to cause disease, although the role of TDP-43 in pathogenesis is unknown. Here we show that TDP-43 forms cytoplasmic mRNP granules that undergo bidirectional, microtubule-dependent transport in neurons in vitro and in vivo and facilitate delivery of target mRNA to distal neuronal compartments. TDP-43 mutations impair this mRNA transport function in vivo and in vitro, including in stem cell-derived motor neurons from ALS patients bearing any one of three different TDP-43 ALS-causing mutations. Thus, TDP43 mutations that cause ALS lead to partial loss of a novel cytoplasmic function of TDP-43. PMID:24507191

Prehospital Blood Product Administration Opportunities in Ground Transport ALS EMS - A Descriptive Study.

Science.gov (United States)

Mix, Felicia M; Zielinski, Martin D; Myers, Lucas A; Berns, Kathy S; Luke, Anurahda; Stubbs, James R; Zietlow, Scott P; Jenkins, Donald H; Sztajnkrycer, Matthew D

2018-06-01

IntroductionHemorrhage remains the major cause of preventable death after trauma. Recent data suggest that earlier blood product administration may improve outcomes. The purpose of this study was to determine whether opportunities exist for blood product transfusion by ground Emergency Medical Services (EMS). This was a single EMS agency retrospective study of ground and helicopter responses from January 1, 2011 through December 31, 2015 for adult trauma patients transported from the scene of injury who met predetermined hemodynamic (HD) parameters for potential transfusion (heart rate [HR]≥120 and/or systolic blood pressure [SBP]≤90). A total of 7,900 scene trauma ground transports occurred during the study period. Of 420 patients meeting HD criteria for transfusion, 53 (12.6%) had a significant mechanism of injury (MOI). Outcome data were available for 51 patients; 17 received blood products during their emergency department (ED) resuscitation. The percentage of patients receiving blood products based upon HD criteria ranged from 1.0% (HR) to 5.9% (SBP) to 38.1% (HR+SBP). In all, 74 Helicopter EMS (HEMS) transports met HD criteria for blood transfusion, of which, 28 patients received prehospital blood transfusion. Statistically significant total patient care time differences were noted for both the HR and the SBP cohorts, with HEMS having longer time intervals; no statistically significant difference in mean total patient care time was noted in the HR+SBP cohort. In this study population, HD parameters alone did not predict need for ED blood product administration. Despite longer transport times, only one-third of HEMS patients meeting HD criteria for blood administration received prehospital transfusion. While one-third of ground Advanced Life Support (ALS) transport patients manifesting HD compromise received blood products in the ED, this represented 0.2% of total trauma transports over the study period. Given complex logistical issues involved in

Formación en Aplicaciones Informáticas para el Tratamiento Digital de Imágenes Aplicadas al Control de una Organización de la Comunidad Valenciana

OpenAIRE

Hernandez Franco, Carlos Alberto; Lloret, Jaime; Viñals Blasco, Mª José

2004-01-01

Desde los distintos niveles de la Administración del Estado Español se han podido constatar los cambios que se están operando en la actividad turística de los ciudadanos, sean estos nacionales, comunitarios o del resto del mundo, y que conllevan, fundamentalmente, a un incremento del turismo de naturaleza, el ecoturismo, el turismo rural, cultural, etc. Las Tecnologías de la Información y las Comunicaciones aplicadas a la actividad turística relacionada con los espacios naturales de España...

Els nous reptes del transport amb autocar a Catalunya: guanyar clientela al vehicle privat

OpenAIRE

Herrán Sánchez, Lluís

1992-01-01

Les empreses catalanes de transport col·lectiu amb autocar s'enfronten als canvis que comporta la integració en el nou mercat europeu, canvis que vindran més per l'adaptació a un mercat en creixement i cada cop més exigent, que no pas per la competència que pugui representar l'entrada d'empreses estrangeres. Oferir serveis de qualitat, tecnificar la gestió empresarial i guanyar clientela al competidor immediat, el vehicle privat, són els principals reptes que ha de superar el sector.

A inserção do ensino de custos na disciplina administração aplicada à enfermagem La inserción de la enseñanza de costos en la disciplina administración aplicada a la enfermería Insertion of cost teaching in the discipline of administration applied to nursing

Directory of Open Access Journals (Sweden)

Ivone Maria Fonseca Francisco

2006-03-01

Full Text Available O objetivo deste texto foi realizar um resgate teórico sobre a traje-tória da disciplina de Admi-nistração Aplicada à Enfermagem, na graduação, ao longo da história do ensino da Enfermagem Brasi-leira, relacionando-a ao ensino de Custos. Percebemos, inseridas no ensino dessa disciplina, diversas citações diretas referentes ao tema Custos ou Economia em Saúde, desde o primeiro currículo de Enfermagem de 1890 até as Diretrizes Curriculares Nacionais do Curso de Graduação em Enfer-magem de 2001, além de citações indiretas relacionadas ao geren-ciamento, tomada de decisão, assessorias em projetos de saúde, entre outras, mas sem haver uma continuidade.Este texto tuvo como objetivo realizar un rescate teórico sobre la trayectoria de la disciplina de Administración Aplicada a la enfermería, en el pregrado, a lo largo de la historia de la enseñanza de la Enfermería Brasileña, relacionándola a la enseñanza de Costos. Percibimos, insertadas en la enseñanza de esa disciplina, diversas citaciones directas referentes al tema Costos o Economía en Salud, desde el primer currículo de Enfermería de 1890 hasta las Directivas Curriculares Nacionales del Pregrado en Enfermería del 2001, además de citaciones indirectas relacionadas al gerenciamiento, toma de decisión, asesorías en proyectos de salud, entre otras, pero sin ninguna continuidad.The objective of this text was to make theoretical rescue of the course of the undergraduate disci-pline Administration Applied to Nursing throughout the history of teaching of Nursing in Brazil, connecting it to the teaching of Costs. We noticed, inserted in the teaching of this discipline, many direct quotes related to the themes of Costs or Economics in Health, from the earliest curriculum in Nursing, dating back to 1890, to the National Curricular Policies of the Nursing Undergraduate Course, of 2001, in addition to indirect quotes related to mana-gement, decision taking, and advising in

Transport, Structural and Mechanical Properties of Quaternary FeVTiAl Alloy

Science.gov (United States)

Bhat, Tahir Mohiuddin; Gupta, Dinesh C.

2016-11-01

The electronic, structural, magnetic and transport properties of FeVTiAl quaternary alloy have been investigated within the framework of density functional theory. The material is a completely spin-polarized half-metallic ferromagnet in its ground state with F-43m structure. The structural stability was further confirmed by elastic constants in the cubic phase with high Young's modulus and brittle nature. The present study predicts an energy band gap of 0.72 eV in a localized minority spin channel at equilibrium lattice parameter of 6.00 Å. The transport properties of the material are discussed based on the Seebeck coefficient, and electrical and thermal conductivity coefficients. The alloy presents large values of Seebeck coefficients, ~39 μV K-1 at room temperature (300 K), and has an excellent thermoelectric performance with ZT = ~0.8.

Thermal and electron transport studies on the valence fluctuating compound YbNiAl4

Science.gov (United States)

Falkowski, M.; Kowalczyk, A.

2018-05-01

We report the thermoelectric power S and thermal conductivity κ measurements on the valence fluctuating compound YbNiAl4, furthermore taking into account the impact of the applied magnetic field. We discuss our new results with revisiting the magnetic [χ(T)], transport [ρ(T)], and thermodynamic [Cp(T)] properties in order to better understand the phenomenon of thermal and electron transport in this compound. The field dependence of the magnetoresistivity data is also given. The temperature dependence of thermoelectric power S(T) was found to exhibit a similar behaviour as expected for Yb-based compounds with divalent or nearly divalent Yb ions. In addition, the values of total thermal conductivity as a function of temperature κ(T) of YbNiAl4 are fairly low compared to those of pure metals which may be linked to the fact that the conduction band is perturbed by strong hybridization. A deeper analysis of the specific heat revealed the low-T anomaly of the ratio Cp(T)/T3, most likely associated with the localized low-frequency oscillators in this alloy. In addition, the Kadowaki-Woods ratio and the Wilson ratio are discussed with respect to the electronic correlations in YbNiAl4.

Estudio de Algoritmos 2-Deslizantes Aplicados al Control de Pilas de Combustible

OpenAIRE

Cristian Kunusch; Paul F. Puleston; Miguel A. Mayosky

2008-01-01

Resumen: En este trabajo se hace un estudio comparativo de tres diferentes técnicas de control por modo deslizante de segundo orden, aplicadas al problema específico del control de respiración de una pila de combustible PEM. Los algoritmos diseñados se contrastan por simulación utilizando el modelo completo del sistema, poniendo particular énfasis en la respuesta transitoria y la robustez frente a perturbaciones. Palabras clave: Pilas de Combustible, Control no lineal, Modo Deslizante

ProduÃÃo acadÃmica brasileira em contabilidade de custos aplicada ao setor pÃblico: plataformas teÃrico metodolÃgicas e aspectos normativos

OpenAIRE

Cicero Philip Soares do Nascimento

2013-01-01

A contabilidade de custos aplicada ao setor pÃblico apresenta-se diante de grandes desafios com o advento das diretrizes para a estruturaÃÃo do sistema de informaÃÃo de custos do setor pÃblico. Tais diretrizes normativas, impulsionadas pelas normas brasileiras de contabilidade aplicadas ao setor pÃblico, possibilitam melhorias na qualidade informacional das informaÃÃes de custos no setor pÃblico. Paralelamente, diante do cenÃrio de potencias mudanÃas da contabilidade de custos aplicada ao set...

Anomalous Transport in Sketched Nanostructures at the LaAlO_{3}/SrTiO_{3} Interface

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Guanglei Cheng

2013-03-01

Full Text Available The oxide heterostructure LaAlO_{3}/SrTiO_{3} supports a two-dimensional electron liquid with a variety of competing phases, including magnetism, superconductivity, and weak antilocalization because of Rashba spin-orbit coupling. Further confinement of this two-dimensional electron liquid to the quasi-one-dimensional regime can provide insight into the underlying physics of this system and reveal new behavior. Here, we describe magnetotransport experiments on narrow LaAlO_{3}/SrTiO_{3} structures created by a conductive atomic force microscope lithography technique. Four-terminal local-transport measurements on Hall bar structures about 10 nm wide yield longitudinal resistances that are comparable to the resistance quantum h/e^{2} and independent of the channel length. Large nonlocal resistances (as large as 10^{4}  Ω are observed in some but not all structures with separations between current and voltage that are large compared to the two-dimensional mean-free path. The nonlocal transport is strongly suppressed by the onset of superconductivity below about 200 mK. The origin of these anomalous transport signatures is not understood, but may arise from coherent transport defined by strong spin-orbit coupling and/or magnetic interactions.

Linguística Aplicada: uma identidade construida nos CBLA Applied Linguistics: an identity constructed in the Brazilian Congresses of Applied Linguistics

OpenAIRE

Renata Archanjo

2011-01-01

Este artigo objetiva investigar a Linguística Aplicada (LA) como um campo de estudos produtor de conhecimento que tem sofrido muitas transformações ao longo de sua trajetória de busca de uma identidade própria. Tais transformações são recuperadas nas vozes de suas pesquisas ao longo dos anos. Assim, esse estudo analisa o percurso histórico da LA, com base na produção científica apresentada nos Congressos Brasileiros de Linguística Aplicada (CBLA), buscando compreender os significados revelado...

Estudio de Algoritmos 2-Deslizantes Aplicados al Control de Pilas de Combustible

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Cristian Kunusch

2008-07-01

Full Text Available Resumen: En este trabajo se hace un estudio comparativo de tres diferentes técnicas de control por modo deslizante de segundo orden, aplicadas al problema específico del control de respiración de una pila de combustible PEM. Los algoritmos diseñados se contrastan por simulación utilizando el modelo completo del sistema, poniendo particular énfasis en la respuesta transitoria y la robustez frente a perturbaciones. Palabras clave: Pilas de Combustible, Control no lineal, Modo Deslizante

Electronic transport in the heavy fermion superconductors UPd2Al3 and UNi2Al3. Thin film studies

International Nuclear Information System (INIS)

Foerster, Michael

2008-01-01

This work addresses the electronical properties of the superconductors UPd 2 Al 3 and UNi 2 Al 3 on the basis of thin film experiments. Epitaxial thin film samples of UPd 2 Al 3 and UNi 2 Al 3 were prepared using UHV Molecular Beam Epitaxy (MBE). For UPd 2 Al 3 , the change of the growth direction from the intrinsic (001) to epitaxial (100) was predicted and sucessfully demonstrated using LaAlO3 substrates cut in (110) direction. With optimized deposition process parameters for UPd 2 Al 3 (100) on LaAlO 3 (110) superconducting samples with critical temperatures up to T c =1.75 K were obtained. UPd 2 Al 3 -AlO x -Ag mesa junctions with superconducting base electrode were prepared and shown to be in the tunneling regime. However, no signatures of a superconducting density of states were observed in the tunneling spectra. The resistive superconducting transition was probed for a possible dependence on the current direction. In contrast to UNi 2 Al 3 , the existence of such feature was excluded in UPd 2 Al 3 (100) thin films. The second focus of this work is the dependence of the resistive transition in UNi 2 Al 3 (100) thin films on the current direction. The experimental fact that the resistive transition occurs at slightly higher temperatures for I parallel a than for I parallel c can be explained within a model of two weakly coupled superconducting bands. Evidence is presented for the key assumption of the two-band model, namely that transport in and out of the ab-plane is generated on different, weakly coupled parts of the Fermi surface. Main indications are the angle dependence of the superconducting transition and the dependence of the upper critical field B c 2 on current and field orientation. Additionally, several possible alternative explanations for the directional splitting of the transition are excluded in this work. An origin due to scattering on crystal defects or impurities is ruled out, likewise a relation to ohmic heating or vortex dynamics. The

II SEMINARIO INTERNACIONAL EN CIENCIAS APLICADAS “Una mirada hacia la innovación y el desarrollo sostenible”

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Diana Verónica Cortés-Espinosa; et. al.

2013-12-01

Full Text Available INTRODUCCIÓN La Química, Biología y las Matemáticas son el pilar de las ciencias aplicadas. La investigación en el área básica se ve reflejada en el desarrollo de disciplinas como las ciencias de la salud, ingenierías y ciencias ambientales. De esta forma, la integración entre la investigación básica y las ciencias aplicadas es fundamental en el desarrollo del profesional moderno. Considerando lo anterior la Facultad de Ciencias Exactas Físicas y Naturales organiza el segundo seminario internacional en Ciencias Aplicadas,como una ventana a la integración de la investigación en la identificación de problemas cotidianos y a la búsqueda de soluciones a los mismos, contribuyendo a la vez el enriquecimiento profesional de los participantes y generando espacios de discusión científica en la Universidad de Santander UDES. OBJETIVOS Desarrollar temáticas de actualidad en diversas áreas del conocimiento con perspectivas de innovación y desarrollo tecnológico en áreas de la salud, investigación y el ambiente. Ofrecer talleres formativos para contextualizar el conocimiento de manera que los asistentes reconozcan las herramientas tecnológicas utilizadas para obtener mejores resultados en su futuro desempeño como profesionales.

CONTABILIDADE APLICADA AO SETOR PÚBLICO COMO MECANISMO INSTITUCIONAL ESTATAL DE MELHORIA DA ACCOUNTABILITY

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Antonio Firmino da Silva Neto

2015-12-01

Full Text Available A informação contábil é um instrumento que proporciona a accountability, que pode ser considerada a razão de ser da Contabilidade. Este ensaio objetiva discutir a Contabilidade Aplicada ao Setor Público como um mecanismo institucional estatal e não-institucional de melhoria de accountability. A metodologia utilizada nesta pesquisa foi a dedutiva com embasamento nos artigos 84 e 110 da Lei Federal no 4.320/1964, Lei de Direito Financeiro, e nas discussões sobre mecanismos de accountability apresentadas por Oakerson (1989, Paul (1992, O’Donnell (1998, 1999, Schedler (1999, Dunn (1999, Elster (1999, Keohane (2002, Mainwaring (2003, Abrucio e Loureiro (2004. As considerações deste estudo são no sentido de que a Contabilidade Aplicada ao Setor Público pode ser caracterizada, preferencialmente, como um mecanismo institucional estatal de accountability, cujo papel é monitorar, fiscalizar, controlar, e com prerrogativas de exigir responsabilização por partes dos agentes públicos, contudo, sem “poderes” de punição ou sanção, mas que pode de uma forma indireta exercer essa prerrogativa como pré-condição para a melhoria da accountability

Magneto-transport properties of oriented Mn{sub 2}CoAl films sputtered on thermally oxidized Si substrates

Energy Technology Data Exchange (ETDEWEB)

Xu, G. Z.; Du, Y.; Zhang, X. M.; Liu, E. K.; Wang, W. H., E-mail: wenhong.wang@iphy.ac.cn; Wu, G. H. [State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, H. G. [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China)

2014-06-16

Spin gapless semiconductors are interesting family of materials by embracing both magnetism and semiconducting due to their unique band structure. Its potential application in future spintronics requires realization in thin film form. In this Letter, we report fabrication and transport properties of spin gapless Mn{sub 2}CoAl films prepared on thermally oxidized Si substrates by magnetron sputtering deposition. The films deposited at 673 K are well oriented to (001) direction and display a uniform-crystalline surface. Magnetotransport measurements on the oriented films reveal a semiconducting-like resistivity, small anomalous Hall conductivity, and linear magnetoresistance representative of the transport signatures of spin gapless semiconductors. The magnetic properties of the films have also been investigated and compared to that of bulk Mn{sub 2}CoAl, showing small discrepancy induced by the composition deviation.

First-principles study of electron transport through monatomic Al and Na wires

DEFF Research Database (Denmark)

Kobayashi, Nobuhiko; Brandbyge, Mads; Tsukada, Masaru

2000-01-01

We present first-principles calculations of electron transport, in particular, the conduction channels of monatomic Al and Na atom wires bridged between metallic jellium electrodes. The electronic structures are calculated by the first-principles recursion-transfer matrix method, and the conduction...... channels are investigated using the eigenchannel decomposition (ECD) of the conductance, the local density of states (LDOS), and the current density. The ECD is different from the conventional decomposition of atomic orbitals, and the study of decomposed electronic structures is shown to be effective...

O Sistema Nacional de Combate ao Abuso e à Exploração Sexual Infantojuvenil e o Plano Nacional: um exemplo de política pública aplicada

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Thaísa Veras

Full Text Available Este artigo tem por objetivo principal tratar de uma política pública aplicada, qual seja, o Sistema Nacional de Combate ao Abuso e à Exploração Sexual Infantojuvenil. Para tanto, inicialmente, é apresentada uma breve definição dos termos, com o intuito de esclarecer a forma como foram interpretados e utilizados no texto. Além disso, é definido o significado de políticas públicas, para que se tenha maior clareza sobre como estas podem auxiliar no entendimento do tema. Por fim, são apresentados os impactos sociais do Sistema Nacional e feito um breve relato sobre o Plano Nacional.

La investigación en biomecánica aplicada a la natación olímpica: Evolución histórica y situación actual

OpenAIRE

Llana Belloch, Salvador; Priego Quesada, José Ignacio; Pérez Soriano, Pedro; Lucas Cuevas, Ángel

2013-01-01

A lo largo de los años, los records mundiales en natación han mejorado de forma notable respecto a otros deportes. Esto se ha debido, tanto a la mejora de la condición física de los nadadores como a la evolución de las técnicas de nado. Gran “culpa” de esto se debe al avance científico en el que se ha visto inmerso este deporte. El presente trabajo tiene como objetivo presentar de una forma organizada y coherente la evolución histórica de la investigación en biomecánica aplicada a la natación...

Dinámica de fluidos computacional aplicada al estudio de regeneradores térmicos

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Cesar Nieto Lodoño

2004-01-01

Full Text Available En el presente artículo, muestra los resultados logrados durante la simulación de un regenerador térmico de lecho poroso empacado, sometido a convección forzada transitoria y su respectiva verificación experimental. Para visualizar la aplicación de la Dinámica de Fluidos Computacional (en inglés Computational Fluid Dynamics, CFD en regeneradores de calor, se realiza un estudio detallado de los elementos que conforman la malla; analizando su distribución, tamaño y respectivo efecto sobre la precisión de los resultados. Se establecen las simplificaciones y alcances de los modelos empleados. Se comprueba la veracidad de los resultados obtenidos, mediante la validación experimental de estos en un modelo físico idéntico al empleado durante la simulación. Estas etapas permitieron observar que el comportamiento exponencial de la temperatura en los elementos empacados durante el periodo de calentamiento, fue idéntico al observado por Mejía [8]. Los resultados obtenidos aquí, verifican la capacidad de la CFD para el estudio de los regeneradores térmicos.

Effects of polarization field on vertical transport in GaN/AlGaN resonant tunneling diodes

International Nuclear Information System (INIS)

Park, Seoung-Hwan; Shim, Jong-In

2012-01-01

Polarization-field effects on the vertical transport in GaN/AlGaN resonant tunneling diodes (RTDs) were theoretically investigated by using the transfer matrix formalism. The self-consistent model shows that the resonant peaks are shifted toward higher energies with increasing Al composition in the AlGaN barrier, and the transmission probability values are shown to decrease rapidly. In the case of the flat-band model, on the other hand, the shift of the resonant peaks is smaller than it is for the self-consistent model and the variation of transmission probability values with increasing Al composition is relatively smaller than that of the self-consistent model. The current voltage characteristics of the self-consistent model are asymmetric while those of the flat-band model are symmetric for positive and negative current directions. The peak-to-valley ratio (PVR) of the self-consistent model is shown to be slightly smaller than that of the flat-band model for Al = 0.3.

EVALUACIÓN DEL ÁREA DE CIENCIAS APLICADAS (600 DEWEY) DE LA COLECCIÓN DE LA BIBLIOTECA “JOAQUIN GARCÍA MONGE”

OpenAIRE

Campos Cerdas, Jorge; Arguedas Ramírez, Sonia; Bermúdez León, Yamileth; Marín Marín, Rafael Angel; Rojas Padilla, María Carlina

2005-01-01

Con esta investigación se pretende determinar la calidad, actualidad, grado de satisfacción de los usuarios, uso y pertinencia de la colección del área de Ciencias Aplicadas de la Biblioteca “Joaquín García Monge” en relación con las necesidades de los usuarios.Se seleccionó como estudio de caso la colección del área de Ciencias Aplicadas de la Biblioteca “Joaquín García Monge” que cubre ciencias ambientales, agrarias y forestales; física y química industrial; medicina veterinaria, psiquiatrí...

Piezoelectric polarization and quantum size effects on the vertical transport in AlGaN/GaN resonant tunneling diodes

International Nuclear Information System (INIS)

Dakhlaoui, H; Almansour, S

2016-01-01

In this work, the electronic properties of resonant tunneling diodes (RTDs) based on GaN-Al x Ga (1−x) N double barriers are investigated by using the non-equilibrium Green functions formalism (NEG). These materials each present a wide conduction band discontinuity and a strong internal piezoelectric field, which greatly affect the electronic transport properties. The electronic density, the transmission coefficient, and the current–voltage characteristics are computed with considering the spontaneous and piezoelectric polarizations. The influence of the quantum size on the transmission coefficient is analyzed by varying GaN quantum well thickness, Al x Ga (1−x) N width, and the aluminum concentration x Al . The results show that the transmission coefficient more strongly depends on the thickness of the quantum well than the barrier; it exhibits a series of resonant peaks and valleys as the quantum well width increases. In addition, it is found that the negative differential resistance (NDR) in the current–voltage ( I – V) characteristic strongly depends on aluminum concentration x Al . It is shown that the peak-to-valley ratio (PVR) increases with x Al value decreasing. These findings open the door for developing vertical transport nitrides-based ISB devices such as THz lasers and detectors. (paper)

Medidas de calidad aplicadas a los levantamientos topográficos en Colombia

OpenAIRE

Sabogal Lemus, Carlos Augusto

2016-01-01

Este trabajo documenta la investigación “Medidas de calidad aplicadas a los levantamientos topográficos en Colombia”; la propuesta metodológica de este documento, tiene como objetivo principal la realización de la evaluación de calidad de un conjunto de datos levantados en campo, para lo cual es necesario revisar los antecedentes de la topografía en Colombia, así como los diferentes sistemas de referencia que gobiernan la cartografía del país -- Previo a realizar una evaluación de calidad, se...

Expertos culturales e intervención social: tensiones y transformaciones en antropología aplicada

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Enrique Jaramillo Buenaventura

2008-12-01

Full Text Available A partir de una breve revisión bibliográfica sobre la antropología aplicada y la antropología del desarrrollo este artículo explora algunos de los problemas teriricos y metodológicos sobre los retos y las implicaciones de pensar a la antropología como un "saber experto" parala intervención social.

Innovación docente y uso de las TICS aplicadas al trabajo colaborativo y al fomento de la creatividad

OpenAIRE

García Gómez, Blanca; Gómez Aguirre, Alfonso; Vargas Soria, Piedad

2015-01-01

Innovación Educativa RESUMEN: Los cambios que hoy caracterizan a la sociedad exigen de las instituciones de educación superior la flexibilización necesaria para adaptar la formación a dichas modificaciones. En este sentido, la preeminencia de las TIC, así como el fomento de sistemas de trabajo colaborativos que contribuyan al desarrollo de capacidades de equipo, son los elementos clave que impulsan este PID. A través de la experimentación se diseñó una metodología docente que se aplicó ...

Defect Formation and Electronic Transport at AlGaN/GaN Interfaces

International Nuclear Information System (INIS)

Haller, E.E.; Hsu, Leonardo; Walukiewicz, W.

1997-01-01

We have calculated the effects of charged defects located near an Al x Ga 1-x N/GaN heterointerface on the transport properties of the two dimensional electron gas confined at the interface and also determined the distribution of those defects taking into consideration the dependence of the formation energy on the Fermi level. In addition, we have investigated the effects of hydrostatic pressure on such modulation doped heterostructures and find that pressure can be used to make the determination of the properties of the two dimensional electron gas easier by eliminating parallel three dimensional conduction paths

Métodos y usos agrícolas de la ingeniería genética aplicada al cultivo de arroz

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Cristina DiazGranados D.

2012-07-01

Full Text Available Methods and agricultural uses of genetic engineering applied to rice crop Resumen: En biotecnología de arroz se han logrado avances en transformación genética, con importantes resultados en el mejoramiento genético de variedades elite de las subespecies japónica e índica. Con el propósito de revisar los métodos y los usos agrícolas de la ingeniería genética aplicada al cultivo del arroz, se usaron varias palabras claves en idioma inglés en algunas de las bases de datos de revistas científicas indexadas, disponibles en el Sistema Nacional de Bibliotecas de la Universidad Nacional de Colombia (SINAB, seleccionando documentos publicados entre 2000 y 2011. La base de esta revisión inicial, se complementó con artículos publicados en fechas anteriores, que se consideraron relevantes, debido a que implicaban cambios metodológicos importantes. Desde que se logró producir la primera planta transgénica de arroz a finales de los 80´s, varios protocolos para la transferencia de genes se han empleado con éxito logrando la modificación genética de más de 60 cultivares de arroz. Para ello se han empleado sistemas de transformación tanto directos como indirectos.  Se han realizado modificaciones de rasgos importantes en el cultivo, tales como la resistencia a factores bióticos (insectos, hongos, bacterias, virus, nematodos, tolerancia a factores abióticos (salinidad, sequía, altas y bajas temperaturas, inmersión, y mejoramiento de características agronómicas (calidad nutricional, rendimiento, uso de nutrientes, tolerancia a herbicidas. Palabras claves: Arroz; cultivos transgénicos; factores bióticos; factores abióticos. Abstract: In rice biotechnology advances have been made in genetic transformation, with significant results in breeding elite varieties of japonica and indica subspecies. In order to review the methods and agricultural uses of genetic engineering applied to rice, calves were used several words in English in

Atributos do Serviço de Transporte no Relacionamento Indústria-VarejoAttributes of Transport Service in Retail-Industry RelationshipAtributos del Servicio de Transporte en la Relación Industria-Ventas al por Menor

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MARTINS, Ricardo Silveira

2011-06-01

the supply chains. In the universe of 400 manufacturing companies located in the state of Minas Gerais, 101 were selected as they had a retail account for more than 60% of their sales, which was analyzed as to the desired constructs and attributed evaluation. In general, industrial shippers seem to minimize the importance of logistics in the retail service, giving the transport merely operational functions and not strategic ones. They fail to aggregate the value of logistics to their products and services. The results forwarded to specific management issues relevant such as the relationship between orders fulfillment and problems of internal processes, structure of distribution channels, logistics networks and decisions about to internalizing/outsourcing logistics services.RESUMENEn el segmento de la distribución, las actividades logísticas se perciben más fácilmente como generadoras de valor. Entre ellas, el transporte tiene gran significado. Así, este estudio tuvo por objetivo analizar la gestión del transporte en las empresas industriales que trabajan con ventas al por menor. La motivación de los estudios se debe a que, en la literatura hay evidencias de que, la forma de gestionar el transporte en términos de atributos del servicio es diferente según el cliente; como también en lo referente al formato de la demanda de servicios de transporte y sus especificidades para atender segmentos de la cadena de suministro. Entre 400 empresas industriales instaladas en el estado de Minas Gerais, se seleccionaron 101, cuyas ventas al por menor correspondían a más del 60% de las ventas, se realizaron análisis de los constructos deseados y evaluación de atributo. En general, los embarcadores industriales parecen minimizar la importancia de la logística en los servicios al por menor y atribuyen al transporte funciones meramente operacionales, o sea, no estratégicas. Por lo tanto, dejan de agregar el valor de la logística a sus productos y servicios. Los

Estrategias flexibilizadoras aplicadas por las empresas del sector avícola del estado Zulia

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María Bonomie

2008-01-01

Full Text Available El artículo tiene como objetivo, analizar las estrategias flexibilizadoras aplicadas en el proceso productivo por las empresas del sector avícola, específicamente las empresas productoras de pollo del estado Zulia. Para tal fin, se describe el proceso productivo de estas empresas y además se identifican las estrategias aplicadas considerando los acontecimientos económicos influenciados por cambios políticos que en los últimos años han incidido en las empresas productoras de pollo. Se realizó una revisión bibliográfica para determinar los criterios de clasificación de las estrategias, asumiendo la establecida por Gamboa y col. (2001. Se diseñó un instrumento semiestructurado, el cual fue administrado a los gerentes y trabajadores de las empresas analizadas. Los resultados obtenidos reflejan, que las empresas utilizan las estrategias con la finalidad de reestructurar y modernizar sus procesos productivos, mejorar continuamente sus productos e introducir nueva tecnología. Se concluye que estas empresas logran incrementar la productividad, aumentando la cantidad de productos ante la utilización óptima de los recursos humanos y tecnológicos, optimización que implica una reducción de costos de producción para poder expandirse y ofrecer precios competitivos en el mercado.

Transport and magnetic properties of new heavy-fermion antiferromagnet YbNi{sub 3}Al{sub 9}

Energy Technology Data Exchange (ETDEWEB)

Ohara, S; Yamashita, T; Mori, Y; Sakamoto, I, E-mail: ohara.shigeo@nitech.ac.jp [Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2011-01-01

We have synthesized a new Yb-based Kondo-lattice compound YbNi{sub 3}Al{sub 9}. This compound crystallizes in a trigonal ErNi{sub 3}Al{sub 9}-type structure (space group R32), in which the Yb-ion is arranged in a two-dimensional honey-comb lattice perpendicular to the c-axis. We report the first measurements of electrical resistivity and magnetization for single-crystalline samples of YbNi{sub 3}Al{sub 9}. The electrical resistivity of YbNi{sub 3}Al{sub 9} is characteristic of the typical properties of heavy-fermion antiferromagnets with a Neel temperature of T{sub N} = 3.4 K. The transport and magnetic properties exhibit large anisotropy in the low-temperature region owing to an interplay among the crystalline-electric-field effect, the Ruderman-Kittel-Kasuya-Yoshida interaction, and the Kondo effect. Below T{sub N}, the metamagnetic transition is observed at a very low magnetic field of around 1 kOe with the field applied along the a-axis. The magnetic structure of YbNi{sub 3}Al{sub 9} is highly sensitive to the applied magnetic field.

Hardening en servidor web Linux Apache, PHP y configurar el firewall de aplicaciones modsecurity para mitigar ataques al servidor

OpenAIRE

Espol; Delgado Quishpe, Byron Alberto

2017-01-01

Realizar un hardening al servidor web, se procederá a revisar las directivas en los archivos de configuración del servicio Apache, PHP, y se procederá a realizar instalación y configuración de un firewall de aplicaciones llamado mod_security la cual nos permitirá mitigar ataques a nuestro servidor web. realizando un análisis de vulnerabilidades encontrado en el servidor. Guayaquil Magíster en Seguridad Informática Aplicada

Decreased Charge Transport Barrier and Recombination of Organic Solar Cells by Constructing Interfacial Nanojunction with Annealing-Free ZnO and Al Layers.

Science.gov (United States)

Liu, Chunyu; Zhang, Dezhong; Li, Zhiqi; Zhang, Xinyuan; Guo, Wenbin; Zhang, Liu; Ruan, Shengping; Long, Yongbing

2017-07-05

To overcome drawbacks of the electron transport layer, such as complex surface defects and unmatched energy levels, we successfully employed a smart semiconductor-metal interfacial nanojunciton in organic solar cells by evaporating an ultrathin Al interlayer onto annealing-free ZnO electron transport layer, resulting in a high fill factor of 73.68% and power conversion efficiency of 9.81%. The construction of ZnO-Al nanojunction could effectively fill the surface defects of ZnO and reduce its work function because of the electron transfer from Al to ZnO by Fermi level equilibrium. The filling of surface defects decreased the interfacial carrier recombination in midgap trap states. The reduced surface work function of ZnO-Al remodulated the interfacial characteristics between ZnO and [6,6]-phenyl C71-butyric acid methyl ester (PC 71 BM), decreasing or even eliminating the interfacial barrier against the electron transport, which is beneficial to improve the electron extraction capacity. The filled surface defects and reduced interfacial barrier were realistically observed by photoluminescence measurements of ZnO film and the performance of electron injection devices, respectively. This work provides a simple and effective method to simultaneously solve the problems of surface defects and unmatched energy level for the annealing-free ZnO or other metal oxide semiconductors, paving a way for the future popularization in photovoltaic devices.

La hipoteràpia aplicada en alumnes amb trastorn de l'espectre autista

OpenAIRE

Sánchez i García, Lorena

2015-01-01

A continuació, es pot trobar un treball de recerca i investigació, conegut amb el nom de Treball final de Grau. El tema principal d’aquest estudi és sobre la hipoteràpia aplicada a alumnes amb autisme, per aquest motiu la principal finalitat d’aquesta recerca és identificar i conèixer com beneficia la teràpia amb cavalls a l’alumnat amb Trastorn de l’Espectre Autista. Per portar a terme aquest procés d’investigació ha sigut necessari el disseny d’un projecte d’investigació que, entre d’alt...

O modelo de Karl Popper sob a ótica das Ciências Sociais Aplicadas

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Milton de Abreu Campanario

2012-04-01

Full Text Available DOI: http://dx.doi.org/10.5007/2175-8077.2012v14n32p124 Karl Popper é o principal filósofo da ciência na modernidade, disputando com Thomas Kuhn a primazia de interpretação do método científico. Claramente há diferentes visões para uma leitura desse importante autor que cunhou o método chamado de dedutivo com teste. O texto reconhece a relevância da visão de Karl Popperno desenvolvimento de trabalhos científicos das ciências exatas e biológicas, onde é amplamente aceita. No entanto, nota-se que essa formulação é pouco sistematizada na área das ciências sociais aplicadas. Este é um ensaio que busca resgatar a sua contribuição, numa tentativa de traduzir os conceitos por ele desenvolvidos de forma didática. Para tanto, será feita uma introdução aos fundamentos da ciência como forma específica de conhecimento, buscando contrastar os métodos dedutivo e indutivo e os procedimentos da ciência formal, básica e aplicada. Uma tentativa de classificar a formulação de proposições a serem testadas ou falseadas é feita com a utilização de diferentes critérios, utilizando exemplos da administração e da economia para ilustração.

Electronic transport in the heavy fermion superconductors UPd{sub 2}Al{sub 3} and UNi{sub 2}Al{sub 3}. Thin film studies

Energy Technology Data Exchange (ETDEWEB)

Foerster, Michael

2008-07-01

This work addresses the electronical properties of the superconductors UPd{sub 2}Al{sub 3} and UNi{sub 2}Al{sub 3} on the basis of thin film experiments. Epitaxial thin film samples of UPd{sub 2}Al{sub 3} and UNi{sub 2}Al{sub 3} were prepared using UHV Molecular Beam Epitaxy (MBE). For UPd{sub 2}Al{sub 3}, the change of the growth direction from the intrinsic (001) to epitaxial (100) was predicted and sucessfully demonstrated using LaAlO3 substrates cut in (110) direction. With optimized deposition process parameters for UPd{sub 2}Al{sub 3} (100) on LaAlO{sub 3}(110) superconducting samples with critical temperatures up to T{sub c}=1.75 K were obtained. UPd{sub 2}Al{sub 3}-AlO{sub x}-Ag mesa junctions with superconducting base electrode were prepared and shown to be in the tunneling regime. However, no signatures of a superconducting density of states were observed in the tunneling spectra. The resistive superconducting transition was probed for a possible dependence on the current direction. In contrast to UNi{sub 2}Al{sub 3}, the existence of such feature was excluded in UPd{sub 2}Al{sub 3}(100) thin films. The second focus of this work is the dependence of the resistive transition in UNi{sub 2}Al{sub 3}(100) thin films on the current direction. The experimental fact that the resistive transition occurs at slightly higher temperatures for I parallel a than for I parallel c can be explained within a model of two weakly coupled superconducting bands. Evidence is presented for the key assumption of the two-band model, namely that transport in and out of the ab-plane is generated on different, weakly coupled parts of the Fermi surface. Main indications are the angle dependence of the superconducting transition and the dependence of the upper critical field B{sub c{sub 2}} on current and field orientation. Additionally, several possible alternative explanations for the directional splitting of the transition are excluded in this work. An origin due to scattering on

Entre puertos, campos y acopios: Trabajo y transporte de granos en torno al Sudeste bonaerense.

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Paula Tagliabue

2014-12-01

Full Text Available En este artículo, se analiza el proceso de trabajo en el transporte automotor de granos en torno al sudeste bonaerense. Desde un abordaje cualitativo, se describen y analizan las prácticas durante la cosecha y pos-cosecha, y los trayectos campo-acopio, acopio-puerto. También se analizan las relaciones laborales a partir de una perspectiva ampliada de las relaciones laborales clásicas (asalariadas, estables, protegidas.Los rasgos que asume el trabajo en el transporte de granos están asociados a los cambios técnicos y tecnológicos de la producción de granos, así como a procesos de flexibilización laboral, vinculados a la disponibilidad permanente para fletar, la extensión de la jornada laboral y la intensidad del trabajo camionero.

Effect of Melt Convection and Solid Transport on Macrosegregation and Grain Structure in Equiaxed Al-Cu Alloys

Science.gov (United States)

Rerko, Rodney S.; deGroh, Henry C., III; Beckermann, Christoph; Gray, Hugh R. (Technical Monitor)

2002-01-01

Macrosegregation in metal casting can be caused by thermal and solutal melt convection, and the transport of unattached solid crystals. These free grains can be a result of, for example, nucleation in the bulk liquid or dendrite fragmentation. In an effort to develop a comprehensive numerical model for the casting of alloys, an experimental study has been conducted to generate benchmark data with which such a solidification model could be tested. The specific goal of the experiments was to examine equiaxed solidification in situations where sinking of grains is (and is not) expected. The objectives were: 1) experimentally study the effects of solid transport and thermosolutal convection on macrosegregation and grain size distribution patterns; and 2) provide a complete set of controlled thermal boundary conditions, temperature data, segregation data, and grain size data, to validate numerical codes. The alloys used were Al-1 wt. pct. Cu, and Al-10 wt. pct. Cu with various amounts of the grain refiner TiB2 added. Cylindrical samples were either cooled from the top, or the bottom. Several trends in the data stand out. In attempting to model these experiments, concentrating on experiments that show clear trends or differences is recommended.

La crisis económica y el "gran salto al vacío" de la dolarización

OpenAIRE

Salgado, Wilma

2000-01-01

Las políticas aplicadas que trataron de impedir la quiebra de los bancos, esto es, las políticas de salvataje bancario, constituyen el principal elemento explicativo de la profundización de la crisis en el Ecuador al haber alimentado la fuga de los capitales -dada la libre circulación internacional de capitales vigente- y en consecuencia, haber alimentado la devaluación monetaria, la inflación, profundizado la recesión económica y deteriorado la situación financiera de las familias ecuatoria...

Tensión aplicada y exposición gradual en un caso de fobia a las inyecciones

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José Pedro Espada Sánchez

2004-01-01

Full Text Available La fobia a las inyecciones es un subtipo de fobia específica caracterizada por respuestas de miedo intenso y por conductas de evitación ante la situación de recibir una inyección. En este trabajo se presenta el caso clínico de una mujer de 28 años que padecía de forma crónica este trastorno, sufriendo desmayos de forma recurrente. El tratamiento se desarrolló durante 6 sesiones semanales de una hora. Los objetivos del tratamiento se establecieron a partir de la hipótesis explicativa de la respuesta de ansiedad ante la sangre. La terapia se centró en enseñar a la paciente a controlar la frecuencia cardiaca y a identificar los síntomas previos al desvanecimiento. Se aplicó un programa multicomponente que combinaba la técnica de la tensión aplicada y estrategias cognitivo-conductuales para el control de la activación anticipatoria y el afrontamiento de la situación fóbica. Las técnicas empleadas fueron la exposición en imaginación enriquecida, exposición en vivo, afrontamiento simbólico, autoinstrucciones y respiración profunda. Se discuten los resultados de la intervención, que confirman la eficacia del programa aplicado.

Sensibilidad a la recompensa y al castigo, personalidad, impulsividad y aprendizaje: Un estudio en un contexto de violencia de pareja

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David Pascual Nicolás

2014-01-01

Full Text Available El objetivo de la presente investigación es estudiar los patrones de sensibilidad a la recompensa y al castigo en una tarea de aprendizaje y su relación con distintas dimensiones de personalidad en una muestra de 81 mujeres víctimas de violencia de pareja. Se evalúa la sensibilidad a la recompensa y al castigo, el afecto positivo y negativo, la impulsividad y la personalidad de los participantes mediante pruebas de auto-informe. En relación al aprendizaje, realizan una tarea de aprendizaje de inversión afectivo. Los análisis de varianza muestran la escasa relación entre medidas de autoinforme y lo que deberían ser sus correlatos conductuales en el paradigma de inversión afectiva, discutiéndose tanto sus implicaciones teóricas como aplicadas.

INTRODUCCIÓN AL MÉTODO CIENTÍFICO EN NIÑOS DE CINCO AÑOS

OpenAIRE

Soler-López, Elena

2013-01-01

Este trabajo pretende introducir a los niños de cinco años en el método científico como proceso que favorece la adquisición y desarrollo de capacidades, habilidades y competencias en los alumnos, estimulando un desarrollo integral de la persona a nivel físico, cognitivo, emocional y social. Para ello, el diseño de la propuesta ha abarcado desde una fundamentación teórica hasta la puesta en práctica de la misma. Este diseño, realizado a través de las fases del método aplicadas al estudio de...

Enhanced two dimensional electron gas transport characteristics in Al2O3/AlInN/GaN metal-oxide-semiconductor high-electron-mobility transistors on Si substrate

International Nuclear Information System (INIS)

Freedsman, J. J.; Watanabe, A.; Urayama, Y.; Egawa, T.

2015-01-01

The authors report on Al 2 O 3 /Al 0.85 In 0.15 N/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistor (MOS-HEMT) on Si fabricated by using atomic layer deposited Al 2 O 3 as gate insulator and passivation layer. The MOS-HEMT with the gate length of 2 μm exhibits excellent direct-current (dc) characteristics with a drain current maximum of 1270 mA/mm at a gate bias of 3 V and an off-state breakdown voltage of 180 V for a gate-drain spacing of 4 μm. Also, the 1 μm-gate MOS-HEMT shows good radio-frequency (rf) response such as current gain and maximum oscillation cut-off frequencies of 10 and 34 GHz, respectively. The capacitance-voltage characteristics at 1 MHz revealed significant increase in two-dimensional electron gas (2DEG) density for the MOS-HEMT compared to conventional Schottky barrier HEMTs. Analyses using drain-source conductivity measurements showed improvements in 2DEG transport characteristics for the MOS-HEMT. The enhancements in dc and rf performances of the Al 2 O 3 /Al 0.85 In 0.15 N/GaN MOS-HEMT are attributed to the improvements in 2DEG characteristics

Piezo-tunnel effect in Al/Al2O3/Al junctions elaborated by atomic layer deposition

Science.gov (United States)

Rafael, R.; Puyoo, E.; Malhaire, C.

2017-11-01

In this work, the electrical transport in Al/Al2O3/Al junctions under mechanical stress is investigated in the perspective to use them as strain sensors. The metal/insulator/metal junctions are elaborated with a low temperature process (≤200 °C) fully compatible with CMOS back-end-of-line. The conduction mechanism in the structure is found to be Fowler-Nordheim tunneling, and efforts are made to extract the relevant physical parameters. Gauge factors up to -32.5 were found in the fabricated devices under tensile stress. Finally, theoretical mechanical considerations give strong evidence that strain sensitivity in Al/Al2O3/Al structures originates not only from geometrical deformations but also from the variation of interface barrier height and/or effective electronic mass in the tunneling oxide layer.

Temporally resolved characterization of shock-heated foam target with Al absorption spectroscopy for fast electron transport study

Energy Technology Data Exchange (ETDEWEB)

Yabuuchi, T.; Sawada, H.; Wei, M. S.; Beg, F. N. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Regan, S. P.; Anderson, K.; Betti, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Hund, J.; Paguio, R. R.; Saito, K. M.; Stephens, R. B. [General Atomics, San Diego, California 92186 (United States); Key, M. H.; Mackinnon, A. J.; McLean, H. S.; Patel, P. K.; Wilks, S. C. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2012-09-15

The CH foam plasma produced by a laser-driven shock wave has been characterized by a temporally resolved Al 1s-2p absorption spectroscopy technique. A 200 mg/cm{sup 3} foam target with Al dopant was developed for this experiment, which used an OMEGA EP [D. D. Meyerhofer et al., J. Phys.: Conf. Ser. 244, 032010 (2010)] long pulse beam with an energy of 1.2 kJ and 3.5 ns pulselength. The plasma temperatures were inferred with the accuracy of 5 eV from the fits to the measurements using an atomic physics code. The results show that the inferred temperature is sustained at 40-45 eV between 6 and 7 ns and decreases to 25 eV at 8 ns. 2-D radiation hydrodynamic simulations show a good agreement with the measurements. Application of the shock-heated foam plasma platform toward fast electron transport experiments is discussed.

Optoelectronic and transport properties of LiBZ (B = Al, In, Ga and Z = Si, Ge, Sn) semiconductors

Science.gov (United States)

Shah, Syed Hatim; Khan, Shah Haider; Laref, A.; Murtaza, G.

2018-02-01

Half-Heusler compounds LiBZ (B = Al, In, Ga and Z = Si, Ge, Sn) are comprehensively investigated using state of the art full potential linearized augmented plane wave (FP-LAPW) method. Stable geometry of the compounds obtained through energy minimization procedure. Lattice constant increased while bulk modulus decreased in replacing the ions of size increasing from top to bottom of the periodic table. Band structure calculations show LiInGe and LiInSn as direct bandgap while LiAlSi, LiInGe and LiGaSn indirect bandgap semiconductors. Density of states demonstrates mixed s, p, d states of cations and anions in the valence and conduction bands. These compounds have mixed ionic and covalent bonding. Compounds show dominant optical response in the visible and low frequency ultraviolet energy region. The transport properties of the compounds are described in terms of Seebeck coefficient, electrical and thermal conductivities. The calculated figure of merit of LiAlSi is in good agreement with the recent experimental results.

Nonlinear electron transport in InAs/AlGaSb three-terminal ballistic junctions

International Nuclear Information System (INIS)

Koyama, M; Inoue, T; Amano, N; Maemoto, T; Sasa, S; Inoue, M

2008-01-01

We have fabricated and characterized an InAs/AlGaSb three-terminal ballistic junction device. The fabricated device exhibited nonlinear electron transport properties because of ballistic motion of electrons in this structure that is comparable to the electron mean free path. When the left branch is biased to a finite voltage Vand the right to a voltage of -V (push-pull fashion), negative voltages appeared at the floating central branch regardless of the polarity of the input voltages. In the case of the central branch grounded in push-pull fashion, the clear current rectification effect also observed in the current flow of the central branch at 4.2K to even at 300K

Las nuevas tecnologías y redes sociales aplicadas al turismo. Caso práctico: turismo de Segovia

OpenAIRE

Gozalo Sanz, Noelia

2013-01-01

Las nuevas tecnologías se han adaptado en un breve período de tiempo a todos los ámbitos de la sociedad y más aún en lo referente al ocio y al turismo, convirtiéndose este mercado en una de las principales industrias a nivel mundial y siendo uno de los más implicados en la promoción en la red. Las nuevas tecnologías y las redes sociales que nos llegan a través de Internet, no son solo un nuevo canal de comunicación, sino un canal de comercialización muy potente, que nos ha abierto las puertas...

O SIGNIFICADO DA ADMINISTRAÇÃO APLICADA À ENFERMAGEM SEGUNDO A OPINIÃO DE GRADUANDAS

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Paulina Kurcgant

Full Text Available Este estudo teve por objetivo conhecer as opiniões que as alunas têm, quando chegam para cursar a disciplina Administração aplicada à Enfermagem. Para tanto, coletou-se as opiniões de 30 alunas do 8° semestre do Curso de Graduação da EEUSP. Os resultados mostraram que as alunas consideram a administração como uma forma de organizar o trabalho e que a função administrativa da enfermeira consiste em conciliar a assistência com a burocracia do serviço.

Caracterização da clientela atendida no Núcleo de Psicologia Aplicada da Universidade Federal do Espírito Santo Profile of the clients assisted at "Núcleo de Psicologia Aplicada" (Applied Psychology Center of the Federal University of Espírito Santo

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Rita de Cássia Ramos Louzada

2003-12-01

Full Text Available Este artigo apresenta o perfil da clientela do Núcleo de Psicologia Aplicada da Universidade Federal do Espírito Santo, de acordo com as seguintes variáveis: sexo, idade, renda familiar, escolaridade, local de moradia, ocupação, motivo da consulta e forma de encaminhamento. Com base nos dados encontrados são feitas reflexões em torno da estruturação deste tipo de serviço, suas articulações com os serviços de saúde mental da rede pública e a formação de psicólogos no âmbito do Estado do Espírito Santo.This article presents the profile of the clients assisted at "Núcleo de Psicologia Aplicada" of Federal University of Espírito Santo, according to the following variables: sex, age, family income, education, place of residence, occupation, reasons for consultation and types of assistance provided. Based on data obtained, some reflections are presented in regard to the organization of this kind of service, its relations with public mental health services and the professional preparation of psychologists in the state of Espírito Santo.

La contribución del turismo al crecimiento económico: análisis regional en México.

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Enrique Sánchez Flores

2016-07-01

Full Text Available El turismo es una actividad económica que se considera cada vez más importante para generar crecimiento económico y combatir la pobreza. Sin embargo, la relación que existe entre el turismo y el crecimiento económico a nivel regional ha sido poco estudiada. En este artículo se presenta la metodología propuesta por Ivanov y Webster para medir la contribución del turismo al crecimiento económico y se aplicada durante el periodo 2004-2012 para las cinco Entidades Federativas con mayor atracción de turistas en México: Quintana Roo, Jalisco, Guerrero, Veracruz y Chiapas. Los resultados indican que en Quintana Roo es el estado donde el turismo contribuye más al crecimiento económico, mientras que Jalisco en el estado donde las actividades turísticas están menos relacionadas al proceso de crecimiento económico.

Inverted Organic Solar Cells with Low-Temperature Al-Doped-ZnO Electron Transport Layer Processed from Aqueous Solution

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Qianni Zhang

2018-01-01

Full Text Available The aqueous-based Zn-ammine complex solutions represent one of the most promising routes to obtain the ZnO electron transport layer (ETL at a low temperature in inverted organic solar cells (OSCs. However, to dope the ZnO film processed from the Zn-ammine complex solutions is difficult since the introduction of metal ions into the Zn-ammine complex is a nontrivial process as ammonium hydroxide tends to precipitate metal salts due to acid-base neutralization reactions. In this paper, we investigate the inverted OSCs with Al-doped-ZnO ETL made by immersion of metallic Al into the Zn-ammine precursor solution. The effects of ZnO layer with different immersion time of Al on film properties and solar cell performance have been studied. The results show that, with the Al-doped-ZnO ETL, an improvement of the device performance could be obtained compared with the device with the un-doped ZnO ETL. The improved device performance is attributed to the enhancement of charge carrier mobility leading to a decreased charge carrier recombination and improved charge collection efficiency. The fabricated thin film transistors with the same ZnO or AZO films confirm the improved electrical characteristics of the Al doped ZnO film.

Trends in energy consumption in the transportation sector of Mexico and its environmental impact; Tendencias del consumo de energia en el Sector Transporte de Mexico y su impacto al medio ambiente

Energy Technology Data Exchange (ETDEWEB)

Mar, E.; Sheinbaum, C. [Instituto de Ingenieria, UNAM, Mexico, D. F. (Mexico)

1997-12-31

serie de problemas de tipo ambiental, los cuales se concentran en mayor escala en las areas urbanas. Por tanto, el estudio del sector transporte como consumidor de energia requiere plantear nuevos terminos donde la constante a estudiar (de forma directa e indirecta) sea la variable ambiental tratando de vincular las actividades propias del sector, su desarrollo y el consumo de energia con el medio ambiente. El objetivo de este articulo es conocer la situacion del sector transporte en el area metropolitana de la ciudad de Mexico (AMCM) y su impacto al medio ambiente. Se trata de un inventario energetico- ambiental enfocado al uso de los combustibles en el sector transporte, cuyo efecto ambiental tiene un costo significativo para el pais. El trabajo se ha dividido en cuatro partes. Primero se caracteriza la importancia del sector como consumidor de energia en el AMCM de forma agregada. Segundo, se describen las principales variables que inciden en el desarrollo del sector para obtener el consumo de forma desagregada, asi como los criterios base para su desarrollo, obteniendo una serie de resultados que muestran la incidencia de los diferentes modos y tipos en el consumo de energia. En la tercera parte, se hace referencia al impacto ambiental generado por el uso de combustibles fosiles en el sector transporte, destacando el modo de transporte que mas impacta por la emision de contaminantes. Por ultimo se presentan una serie de alternativas que permitiran encontrar un balance entre ransporte-energia-medio ambiente.

Trends in energy consumption in the transportation sector of Mexico and its environmental impact; Tendencias del consumo de energia en el Sector Transporte de Mexico y su impacto al medio ambiente

Energy Technology Data Exchange (ETDEWEB)

Mar, E; Sheinbaum, C [Instituto de Ingenieria, UNAM, Mexico, D. F. (Mexico)

1998-12-31

serie de problemas de tipo ambiental, los cuales se concentran en mayor escala en las areas urbanas. Por tanto, el estudio del sector transporte como consumidor de energia requiere plantear nuevos terminos donde la constante a estudiar (de forma directa e indirecta) sea la variable ambiental tratando de vincular las actividades propias del sector, su desarrollo y el consumo de energia con el medio ambiente. El objetivo de este articulo es conocer la situacion del sector transporte en el area metropolitana de la ciudad de Mexico (AMCM) y su impacto al medio ambiente. Se trata de un inventario energetico- ambiental enfocado al uso de los combustibles en el sector transporte, cuyo efecto ambiental tiene un costo significativo para el pais. El trabajo se ha dividido en cuatro partes. Primero se caracteriza la importancia del sector como consumidor de energia en el AMCM de forma agregada. Segundo, se describen las principales variables que inciden en el desarrollo del sector para obtener el consumo de forma desagregada, asi como los criterios base para su desarrollo, obteniendo una serie de resultados que muestran la incidencia de los diferentes modos y tipos en el consumo de energia. En la tercera parte, se hace referencia al impacto ambiental generado por el uso de combustibles fosiles en el sector transporte, destacando el modo de transporte que mas impacta por la emision de contaminantes. Por ultimo se presentan una serie de alternativas que permitiran encontrar un balance entre ransporte-energia-medio ambiente.

Minería de datos aplicada en detección de intrusos

Directory of Open Access Journals (Sweden)

Diego Vallejo P.

2012-06-01

Full Text Available Con base a los fundamentos y técnicas de la minería de datos se pueden diseñar y elaborar modelos que permiten encontrar comportamientos clandestinos de fácil detección a simple vista como lo es la información no evidente -desconocida a priori y potencialmente útil- en referencia a hechos determinados. En particular la utilidad de la minería de datos en esta área radica en una serie de técnicas, algoritmos y métodos que imitan la característica humana del aprendizaje: ser capaz de extraer nuevos conocimientos a partir de las experiencias. La minería de datos posee características como: análisis de grandes volúmenes de información, generación de comportamientos que no son fácilmente perceptibles, depuración de datos para toma de decisiones. Estas características pueden ser de vital importancia para ser aplicadas en la seguridad de la información a través de la detección de intrusos. En la actualidad la seguridad de la información es uno de los grandes retos que tiene el mundo, y en especial, la detección de anomalías en los registros de acceso de los diferentes sistemas de información. Con esta aplicabilidad resulta un método básico y muy eficiente de poder prevenir intrusiones. Se centra el campo de en la detección de intrusos al nutrir el proceso de seguimiento de los acontecimientos que ocurren en la red informática, seguido del análisis de los mismos; con el fin de detectar los factores que ponen en peligro la confidencialidad, integridad, disponibilidad y no repudio de los datos. En el presente trabajo se pretende mostrar el aporte a la seguridad de la información de la minería de datos en el contexto de la detección de intrusos.

El paradigma del ZMOT como modelo de negocio aplicado al sector turístico en el año 2013 : estudio sobre el comportamiento del consumidor turístico de la Ciudad Autónoma de Buenos Aires en los medios online

OpenAIRE

Costas Chillemi, Martín

2014-01-01

Costas Chillemi, M. (2014). El paradigma del ZMOT como modelo de negocio aplicado al sector Turístico en el año 2013. Estudio sobre el comportamiento del consumidor turístico de la Ciudad Autónoma de Buenos Aires en los medios online (Tesis de posgrado). Universidad Nacional de Quilmes, Bernal, Argentina. El presente estudio es de finalidad aplicada, alcance temporal transversal y grado de conocimiento Exploratorio, fundamentalmente porque se realiza un primer acercamiento al fenómeno del ...

Fluência em filtros cerâmicos de Al2O3 Creep in Al2O3 ceramic filters

Directory of Open Access Journals (Sweden)

V. R. Salvini

2001-12-01

Full Text Available O comportamento de fluência em materiais cerâmicos sólidos é afetado pela sua microestrutura. Fundamentalmente, são três os parâmetros que influenciam o comportamento de fluência nestes materiais: o constituinte mineralógico, a fase vítrea e a porosidade. Além destes fatores microestruturais, a fluência em cerâmicas celulares depende também da sua macroestrutura, constituída de um arranjo tridimensional de filamentos sólidos interligados. Assim, a análise dos resultados de fluência nestes materiais compreende duas etapas: na primeira deve-se identificar o modo de deformação dos filamentos cerâmicos (macroestrutura e na segunda, identificar o(s mecanismo(s de fluência da microestrutura através dos parâmetros n (expoente da tensão aplicada e Q (energia de ativação do processo. Neste trabalho avaliou-se a fluência em filtros cerâmicos de Al2O3 de 10 ppi sob compressão de 0,034; 0,051 e 0,068 MPa às temperaturas de 1500, 1550 e 1600 ºC ao ar. De acordo com os resultados obtidos, supõe-se que o modo de deformação por flambagem dos filamentos paralelos a carga aplicada é um dos principais fatores que contribui para o aumento da taxa de deformação do filtro e, portanto, dos valores de n e Q. Além do modo de deformação dos filamentos, observou-se que o tipo de ensaio de fluência (com ou sem troca de carga também influencia a determinação dos valores de n e Q.The creep behavior of solid ceramics is strongly affected by the microstructure. Fundamentally, there are three microstructural features which influence the creep behavior: the mineral content, the flux content and the apparent porosity. Additionally, the creep of cellular ceramics also depends on their macrostructure constituted by a tridimensional array of struts. Therefore, the creep analysis of these materials should consist of two stages. Firstly, identification of the macrostructure deformation mode and secondly, determination of the stress exponent

Caos, complexidade e Lingüística Aplicada: diálogos transdisciplinares

Directory of Open Access Journals (Sweden)

Antônio Carlos Soares Martins

2007-01-01

Full Text Available Neste texto, apresentamos um panorama de estudos na área da Lingüística Aplicada que discutem questões relativas ao processo de desenvolvimento de segunda língua, bem como aspectos relacionados aos ambientes interacionais de aprendizagem na perspectiva das teorias do Caos e Complexidade. Para isso, discutimos as principais noções da perspectiva da complexidade, retomando alguns aspectos da física clássica e contemporânea.In this paper, we present a panorama of studies in the area of Applied Linguistics that discuss questions regarding second language development as well as aspects related to interactional learning environments in the light of Chaos and Complexity theories. To accomplish this, we discuss the main notions of complexity through the rethinking of some aspects of classic and contemporary physics.

Transport properties of LaAlO{sub 3}/SrTiO{sub 3} nanostructures

Energy Technology Data Exchange (ETDEWEB)

Mueller, Alexander; Minhas, Mohsin; Blaschek, Hans-Helmuth [Institut fuer Physik, Martin-Luther-Universitaet Halle-Wittenberg, 06099 Halle (Saale) (Germany); Schmidt, Georg [Institut fuer Physik, Martin-Luther-Universitaet Halle-Wittenberg, 06099 Halle (Saale) (Germany); Interdisziplinaeres Zentrum fuer Materialwissenschaften, Martin-Luther-Universitaet Halle-Wittenberg, 06099 Halle (Saale) (Germany)

2015-07-01

Deposition of thin layers of LaAlO{sub 3} (LAO) on top of a TiO{sub 2} terminated SrTiO{sub 3} (STO) substrate with Pulsed Laser Deposition results in a two dimensional electron gas at the interface. Using PMMA as resist and etch mask this electron gas can be patterned by a standard electron-beam lithography step and subsequent Reactive Ion Etching to remove the LAO. With this process transport structures with minimum dimensions in the sub-micron regime have been fabricated. The structures include gaps of approx. 100 nm width. Transport through the gap is characterized by taking I/V characteristics in a standard four point geometry from room temperature down to 1.5 K. Between 1.5 and 30 K up to a threshold voltage of tens of mV no current is observed. Beyond that threshold voltage the current increases dramatically. Within a few tens of mV the current can increase by up to eight orders of magnitude. The threshold voltage is temperature dependent in a non-monotonic fashion and all I/V curves are free of any hysteresis.

Aportes del liderazgo, la comunicación y el trabajo en equipo al clima organizacional: un análisis del caso Bancolombia de Arauca

OpenAIRE

León Fandiño, Jenitze Liliana

2013-01-01

El interés de esta investigación fue identificar los aportes de las dimensiones Liderazgo, Comunicación y Trabajo en equipo al clima organizacional en el caso Bancolombia, Arauca. Para ello se utilizó el instrumento de recolección de datos adaptado Organizational Climate Questional, modelo de Litwin y Stringer. Los resultados demostraron que las 3 dimensiones aplicadas para la determinación del clima se encuentran percibidas de forma positiva por los empleados de la organización. Se constató ...

Dinámica de Sistemas aplicada al Mercado de Hidrocarburos Líquidos en España

OpenAIRE

Bozhidarova Vladimirova, Natali

2015-01-01

En primer lugar, en este TFG se trata el mercado de petróleo a nivel mundial, comentando las reservas, la producción y el consumo de petróleo producidos en los últimos diez años, así como, los principales conflictos bélicos sucedidos en la historia, ligados estrechamente al petróleo. En segundo lugar, se aporta información relevante sobre el mercado de hidrocarburos en España, para después, aplicar la Dinámica de Sistemas a este mercado y poder ver la evolución que tendrán las variables princ...

Perceptions of transport corridors and intermodal transport - as ways to control the space of freight transport flows

DEFF Research Database (Denmark)

Hansen, Leif Gjesing

2009-01-01

This paper presents empirical findings and results from a study conducted as a part of an INTERREG IIIB project on intermodal transport solutions and corridors in the North Sea Region (SUTRANET - Sustainable Transport Research & Development Network in the North Sea Region (Hansen et.al., 2007......; Kristiansen et.al., 2005 and http://www.sutranet.org/ ). The aim of the study has been to explore possibilities and barriers for the development of intermodal transport solutions in selected corridors in the North Sea Region. The North Sea Region is one among several regions appointed by the EU......-Commission to exemplify the operationalisation of the concept Motorways of the Sea (European Commission, 2004). The policies of promoting Motorways of the Sea is aiming at revitalise the short-sea-shipping within Europe as a transport industry, but also to relieve the heavily congested road network in central regions...

Centro de Investigaciones Nucleares Aplicadas a la Agricultura (CINAGRI). Venezuela. Final report of the projects VEN/86/007 and VEN/5/009

International Nuclear Information System (INIS)

Gil, J.L.

1992-01-01

The summary of the technical activities carried out on the project ''Centro de Investigaciones Nucleares Aplicadas a la Agricultura'' (CINAGRI) is presented. The objectives of this project are to establish nuclear and biotechnology techniques, practices with a view to increasing agriculture and live-stock productivity, and to transfer this technology to farmers

Enhanced two dimensional electron gas transport characteristics in Al{sub 2}O{sub 3}/AlInN/GaN metal-oxide-semiconductor high-electron-mobility transistors on Si substrate

Energy Technology Data Exchange (ETDEWEB)

Freedsman, J. J., E-mail: freedy54@gmail.com; Watanabe, A.; Urayama, Y. [Research Center for Nano-Devices and Advanced Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466 8555 (Japan); Egawa, T., E-mail: egawa.takashi@nitech.ac.jp [Research Center for Nano-Devices and Advanced Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466 8555 (Japan); Innovation Center for Multi-Business of Nitride Semiconductors, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466 8555 (Japan)

2015-09-07

The authors report on Al{sub 2}O{sub 3}/Al{sub 0.85}In{sub 0.15}N/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistor (MOS-HEMT) on Si fabricated by using atomic layer deposited Al{sub 2}O{sub 3} as gate insulator and passivation layer. The MOS-HEMT with the gate length of 2 μm exhibits excellent direct-current (dc) characteristics with a drain current maximum of 1270 mA/mm at a gate bias of 3 V and an off-state breakdown voltage of 180 V for a gate-drain spacing of 4 μm. Also, the 1 μm-gate MOS-HEMT shows good radio-frequency (rf) response such as current gain and maximum oscillation cut-off frequencies of 10 and 34 GHz, respectively. The capacitance-voltage characteristics at 1 MHz revealed significant increase in two-dimensional electron gas (2DEG) density for the MOS-HEMT compared to conventional Schottky barrier HEMTs. Analyses using drain-source conductivity measurements showed improvements in 2DEG transport characteristics for the MOS-HEMT. The enhancements in dc and rf performances of the Al{sub 2}O{sub 3}/Al{sub 0.85}In{sub 0.15}N/GaN MOS-HEMT are attributed to the improvements in 2DEG characteristics.

La wiki-webquest: una actividad colaborativa en la asignatura de "Nuevas Tecnologías Aplicadas a la Educación"

Directory of Open Access Journals (Sweden)

Roberto Santos Fernández

2010-01-01

Full Text Available Las instituciones de educación superior están sufriendo un proceso de reconversión buscando su adaptación a las características del Espacio Europeo de Educación Superior. Uno de los cambios más importantes, a los que debe hacer frente su profesorado, consiste en una reorganización metodológica diferente de sus clases. Por ello, es necesario pensar en nuevas fórmulas en la formación del profesorado. Como resultado de esta necesidad, decidimos organizar la asignatura de Nuevas Tecnologías Aplicadas a la Educación, de la Facultad de Educación de Valladolid, empleando una metodología activa, el IBL, apoyada en una plataforma Wiki, proponiendo a nuestro alumnado una serie de actividades que debían realizar colaborativamente. En este trabajo, presentamos una de esas actividades, la elaboración de una Wiki- WebQuest. A partir de la descripción de esta actividad, pretendemos mostrar algunas luces y sombras sobre su puesta en práctica (la versatilidad y flexibilidad de la plataforma, la posibilidad de colaboración entre la universidad y la escuela, la falta de adaptación de algunos contenidos al nivel curricular del curso concreto, la falta de asesoramiento del profesorado al alumnado de primaria sobre el uso de estas nuevas herramientas, etc. Esta actividad fue desarrollada a partir de la colaboración con contextos educativos reales (dos centros de primaria, sirviendo de caso de estudio para diseñar una Wiki-WebQuest. Asimismo, también colaboraron dos asignaturas de la titulación de Magisterio (Didáctica General y Metodología del Idioma Extranjero, con el objetivo de enriquecer el proceso de aprendizaje.

Análisis de datos con Excel: Una herramienta al alcance de todos.

Directory of Open Access Journals (Sweden)

M. L. Martínez Romero

2000-01-01

Full Text Available En la actualidad, cualquier alumno puede disponer de un ordenador y del paquete Microsoft office, el cual incorpora un módulo de herramientas para análisis de datos. Elegimos dicho programa por varias razones, en primer lugar por su facilidad de manejo, en segundo por ser utilizado en la asignatura Informática Aplicada a la Gestión de la Empresa y por último por ser uno de los programas de más uso en la empresa hoy en día. El objetivo de dicha práctica era que el alumno resolviese un problema estadístico de actualidad utilizando como soporte informático el programa Excel, y a partir de los resultados obtenidos, comprender la información y usarla eficazmente. Al finalizar la práctica se pasó una encuesta a los alumnos para medir la consecución de los objetivos a conseguir, así como su nivel de satisfacción. Los resultados obtenidos los presentamos al final del trabajo.

Simulation of electron transport in GaAs/AlAs superlattices with a small number of periods for the THz frequency range

International Nuclear Information System (INIS)

Pavelyev, D. G.; Vasilev, A. P.; Kozlov, V. A.; Koschurinov, Yu. I.; Obolenskaya, E. S.; Obolensky, S. V.; Ustinov, V. M.

2016-01-01

The electron transport in superlattices based on GaAs/AlAs heterostructures with a small number of periods (6 periods) is calculated by the Monte Carlo method. These superlattices are used in terahertz diodes for the frequency stabilization of quantum cascade lasers in the range up to 4.7 THz. The band structure of superlattices with different numbers of AlAs monolayers is considered and their current–voltage characteristics are calculated. The calculated current–voltage characteristics are compared with the experimental data. The possibility of the efficient application of these superlattices in the THz frequency range is established both theoretically and experimentally.

Numerical study of the impact of inoculant and grain transport on macrosegregation and microstructure formation during solidification of an Al-22%Cu alloy

International Nuclear Information System (INIS)

Tveito, K O; M'Hamdi, M; Bedel, M; Zaloz'nik, M; Combeau, H; Kumar, A; Dutta, P

2012-01-01

We investigate the impact of the nucleation law for nucleation on Al-Ti-B inoculant particles, of the motion of inoculant particles and of the motion of grains on the predicted macrosegregation and microstructure in a grain-refined Al-22 wt.% Cu alloy casting. We conduct the study by numerical simulations of a casting experiment in a side-cooled 76×76×254 mm sand mould. Macrosegregation and microstructure formation are studied with a volume-averaged two-phase model accounting for macroscopic heat and solute transport, melt convection, and transport of inoculant particles and equiaxed grains. On the microscopic scale it accounts for nucleation on inoculant particles with a given size distribution (and corresponding activation undercooling distribution)and for the growth of globular solid grains. The growth kinetics is described by accounting for limited solute diffusion in both liquid and solid phases and for convective effects. We show that the consideration of a size distribution of the inoculants has a strong impact on the microstructure(final grain size) prediction. The transport of inoculants significantly increases the microstructure heterogeneities and the grain motion refines the microstructure and reduces the microstructure heterogeneities.

La biotecnología aplicada al medio ambiente

OpenAIRE

Pueyo, José Javier

2002-01-01

La Federación Europea de Biotecnología define biotecnología como el uso integrado de la bioquímica, la microbiología, y la ingenieria para la consecución de aplicaciones de las capacidades de microorganismos, células cultivadas animales o vegetales.

VULNERABILIDAD DE REDES COMPLEJAS Y APLICACIONES AL TRANSPORTE URBANO: UNA REVISIÓN DE LA LITERATURA

Directory of Open Access Journals (Sweden)

Laura Lotero Vélez

Full Text Available El interés de investigadores y profesionales de diversas disciplinas en el análisis de sistemas sociales, biológicos y artificiales desde la perspectiva de las redes complejas ha crecido notablemente en los últimos años. Algunas de estas redes son la base de muchas de las actividades del ser humano, como es el caso de las redes de transporte urbano que hacen parte de la infraestructura crítica. Una de las propiedades de mayor relevancia práctica de las redes complejas es su capacidad para mantener algunas funciones cuando ocurren fallas, errores o ataques a sus nodos o vínculos, la cual ha sido denominada robustez, resiliencia o vulnerabilidad por distintos autores. En este artículo se presenta una revisión de la literatura sobre el concepto de vulnerabilidad en el formalismo de las redes complejas y algunas aplicaciones al transporte urbano. El propósito de este artículo de revisión es el de dar a conocer a académicos y tomadores de decisión nuevos enfoques para el análisis del sistema de movilidad.

Insight into electronic, mechanical and transport properties of quaternary CoVTiAl: Spin-polarized DFT + U approach

Energy Technology Data Exchange (ETDEWEB)

Yousuf, Saleem, E-mail: nengroosaleem17@gmail.com; Gupta, D.C., E-mail: sosfizix@gmail.com

2017-07-15

Highlights: • 100% spin-polarized material important for the application in spintronics. • It is ferromagnetic and ductile in nature. • Shows semiconducting behavior with a band gap of 1.06 eV. • Possibly efficient high temperature thermoelectric material. - Abstract: We present a preliminary investigation of band structure and thermoelectric properties of new quaternary CoVTiAl Heusler alloy. Structural, magnetic property and 100% spin polarization of equiatomic CoVTiAl predicts ferromagnetic stable ground state. Band profile outlines the indirect semiconducting behavior in spin down channel with band gap of 1.06 eV, and the magnetic moment of 3 µ{sub B} in accordance with Slater-Pauling rule. To evaluate the accuracy of different approximations in predicting thermoelectric properties, the comparison with available experimental data is made which shows fair agreement for the transport coefficients. The high temperature (800 K) positive Seebeck coefficient of 73.71 µV/K describes the p-type character of the material with high efficiency due to highly influential semiconducting behavior around the Fermi level. Considering the combination of 100% spin-polarization, high Seebeck coefficient and large figure of merit, ferromagnetic semiconducting CoVTiAl may prove as a potential candidate for high temperature thermoelectrics and an ideal spin source material for spintronic applications.

Strain induced effects on the transport properties of metamorphic InAlAs/InGaAs quantum wells

International Nuclear Information System (INIS)

Capotondi, F.; Biasiol, G.; Ercolani, D.; Grillo, V.; Carlino, E.; Romanato, F.; Sorba, L.

2005-01-01

The relationship between structural and low-temperature transport properties is explored for In x Al 1 - x As/In x Ga 1 - x As metamorphic quantum wells with x > 0.7 grown on GaAs by molecular beam epitaxy. Different step-graded buffer layers are used to gradually adapt the in-plane lattice parameter from the GaAs towards the InGaAs value. We show that using buffer layers with a suitable maximum In content the residual compressive strain in the quantum well region can be strongly reduced. Samples with virtually no residual strain in the quantum well region show a low-temperature electron mobility up to 29 m 2 /V s while for samples with higher residual compressive strain the low-temperature mobility is reduced. Furthermore, for samples with buffers inducing a tensile strain in the quantum well region, deep grooves are observed on the surface, and in correspondence we notice a strong deterioration of the low-temperature transport properties

Columnar to equiaxed transition in a refined Al-Cu alloy under diffusive and convective transport conditions

Energy Technology Data Exchange (ETDEWEB)

Dupouy, M.D.; Camel, D.; Mazille, J.E. [CEA Centre d' Etudes et de Recherches sur les Materiaux, 38 - Grenoble (France); Hugon, I. [Lab. de Metallographie, DCC/DTE/SIM, CEA Valrho (France)

2000-07-01

The columnar-equiaxed transition under diffusive transport conditions was studied in microgravity (EUROMIR95 and spacelab-LMS96) by solidifying four Al-4wt%Cu alloys refined at different levels, with a constant cooling rate (1 K/min), both under nearly isothermal conditions and under a decreasing temperature gradient. Isothermal samples showed a homogeneous equiaxed structure with no fading of the refiner efficiency. Gradient samples revealed a continuous transition consisting of an orientation of the microsegregation parallel to the solidification direction, without any grain selection effect. For comparison, ground samples evidence the influence of the motion of both refiner particles and growing equiaxed grains. (orig.)

METODOLOGIA DE ENSINO ORIENTADA PARA PROJETOS: UM ESTUDO DE CASO DA DISCIPLINA DE ESTATÍSTICA APLICADA DO CURSO DE GESTÃO AMBIENTAL DO CEFET/RN

Directory of Open Access Journals (Sweden)

JOÃO MARIA FILGUEIRA

2007-12-01

Full Text Available A presente pesquisa tem como objetivo avaliar uma metodologia de ensino orientada para projetos, utilizada na disciplina “Estatística Aplicada” na turma 3.77.1N do curso superior de Tecnologia em Gestão Ambiental do CEFET-RN. É proposta uma discussão em relação à metodologia aplicada a fim de se obter sugestões de melhoria, além de avaliar o grau de satisfação do aluno no que diz respeito à importância da referida disciplina para o curso. Para tanto, foram realizados levantamentos bibliográficos e pesquisas destinadas aos alunos que cursaram a disciplina. Em relação aos resultados alcançados, pode-se destacar uma melhora no aprendizado do aluno, na medida em que ele pôde se envolver com situações reais da sua área de atuação. Foi possível depreender da pesquisa que o modelo Pedagogia de Projetos é altamente viável e proporciona uma maior integração entre os alunos. Palavras-chave: pesquisa, questionário, metodologia, pedagogia de projetos, estatística, aprendizagem.

Monte Carlo Transport for Electron Thermal Transport

Science.gov (United States)

Chenhall, Jeffrey; Cao, Duc; Moses, Gregory

2015-11-01

The iSNB (implicit Schurtz Nicolai Busquet multigroup electron thermal transport method of Cao et al. is adapted into a Monte Carlo transport method in order to better model the effects of non-local behavior. The end goal is a hybrid transport-diffusion method that combines Monte Carlo Transport with a discrete diffusion Monte Carlo (DDMC). The hybrid method will combine the efficiency of a diffusion method in short mean free path regions with the accuracy of a transport method in long mean free path regions. The Monte Carlo nature of the approach allows the algorithm to be massively parallelized. Work to date on the method will be presented. This work was supported by Sandia National Laboratory - Albuquerque and the University of Rochester Laboratory for Laser Energetics.

Advantages of electrical propulsion applied to the urban transportation with express lines; Vantagens da propulsao eletrica aplicada ao transporte urbano em linhas expressas

Energy Technology Data Exchange (ETDEWEB)

Schwob, Marcelo Rousseau Valenca; Rodrigues, Joaquim Augusto Pinto; Henriques Junior, Mauricio F.; Dresch, Patricia Miranda; Dantas, Fabricio dos Santos [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil). Div. de Energia], E-mail: energia@int.gov.br; Bernardes, Fernanda Manhaes [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

2010-07-01

This paper intends to compare the various possible solutions for urban bus propulsion under the environmental aspects (gaseous emissions, vibrations and noises), energy efficiency and energetic operational costs, facing the evident signals of energy inefficiency and environmental limitations presented at urban highway transports of large cities.

Adaptación al español del instrumento sobre cultura organizacional de Denison

Directory of Open Access Journals (Sweden)

Tomás Bonavia

2013-08-01

Full Text Available En este estudio se presentan los resultados de la adaptación a grupos I+D universitarios de habla hispanade la encuesta sobre cultura organizacional de Denison. Este cuestionario, compuesto por 60 ítems que identifican 12 tipos culturales, que a su vez se agrupan en cuatro dimensiones, ha demostrado su influencia para aumentar la efectividad organizacional. La adaptación al castellano que aquí se propone ha sido aplicada a 488 personas pertenecientes a 39 grupos de I+D tecnológicos de la Universidad Politécnica de Valencia. Los resultados obtenidos muestran unas propiedades psicométricas adecuadas para la adaptación realizada en cuanto a validez y fiabilidad, que replican casi en su totalidad la estructura del modelo de la versión original.

Ajuste de parâmetros de transporte de solutos no solo utilizando Matlab 6.5 Adjustment of soil solute transport parameters with Matlab 6.5

Directory of Open Access Journals (Sweden)

Anderson L. de Souza

2011-12-01

Full Text Available O sucesso na utilização de modelos matemáticos no estudo do transporte de íons no solo está intimamente ligado à precisão com que os parâmetros de transporte envolvidos neste processo são estabelecidos. De maneira geral, tais parâmetros são determinados mediante a resolução de um problema de otimização não linear em que os dados experimentais, obtidos em ensaios de deslocamento miscível, são ajustados a um modelo teórico. Neste sentido, a utilização de softwares de alta performance no ajuste destes parâmetros mostra-se vantajosa, uma vez que, além da consistência e da disponibilidade de ferramentas numéricas preexistentes, possibilita a incorporação de novas rotinas de acordo com o fenômeno que se queira simular. Sendo assim, este trabalho teve como objetivo desenvolver, em ambiente MATLAB 6.5, uma rotina computacional para a otimização dos seguintes parâmetros de transporte: fator de retardamento (R e coeficiente de dispersão (D. A rotina desenvolvida foi aplicada a dados experimentais de três ensaios de deslocamento miscível do íon potássio em colunas preenchidas com um Latossolo Vermelho- -Amarelo, fase arenosa. A qualidade dos ajustes obtidos foi avaliada utilizando-se do coeficiente de exatidão. Concluiu-se que a rotina proposta apresentou ótimo desempenho, o que, além de reforçar a consistência do método numérico utilizado, indica que a rotina proposta neste trabalho pode contribuir com o avanço dos estudos teóricos da dinâmica da água e de solutos em meios porosos não saturados.The successful use of mathematical models in studies of solute transport in soil is dependent on the accuracy to which the transport parameters involved in this process can be specified. In general, these parameters are determined by using nonlinear optimization techniques to fit theoretical models to experimental data obtained in miscible displacement experiments. The use, therefore, of high-performance software to

Transporte e sorção do agroquímico paclobutrazol em solos irrigados cultivados com manga

OpenAIRE

Lúcia Milfont de Souza, Monica

2006-01-01

O aumento nas áreas cultivadas com manga, no mundo e no Brasil, conduziu a um aumento no uso de reguladores de crescimento vegetal, como o paclobutrazol. Apesar da grande quantidade de paclobutrazol que é aplicada às culturas e do risco de contaminação dos aqüíferos associados a essa molécula, seu destino no solo ainda não está claro e é pobremente documentado. Neste trabalho foram estudadas as interações físico-químicas e os mecanismos envolvidos no transporte da molécula do paclobutrazol na...

Teaching the Modes of Ca[superscript 2+] Transport between the Plasma Membrane and Endoplasmic Reticulum Using a Classic Paper by Kwan et al.

Science.gov (United States)

Liang, Willmann

2009-01-01

This teaching article uses the report by Kwan et al., "Effects of methacholine, thapsigargin, and La[superscript 3+] on plasmalemmal and intracellular Ca[superscript 2+] transport in lacrimal acinar cells," where the effects of Ca[superscript 2+]-mobilizing agents in regulating Ca[superscript 2+] fluxes were examined under various conditions.…

Inteligência Competitiva: metodologias aplicadas em empresas brasileirasInteligencia Competitiva: metodologías aplicadas en las empresas brasileñas

Directory of Open Access Journals (Sweden)

Mônica Erichsen Nassif

2012-01-01

Full Text Available Introdução: Apresenta um panorama acerca da Inteligência Competitiva no contexto das organizações brasileiras. Objetivo: Investiga a existência de metodologias de Inteligência Competitiva aplicadas a organizações nacionais e multinacionais de diferentes segmentos de mercado. Metodologia: Revisão de literatura nacional e internacional – envolvendo o status quo da atividade de Inteligência Competitiva no mundo – e cujo conteúdo foi confrontado com os resultados obtidos em entrevistas realizadas em 13 organizações nacionais e multinacionais com atuação no Brasil, no período de dezembro de 2010 a abril de 2011. Resultados: No artigo foram analisados os diferentes objetivos e experiências de Inteligência Competitiva em organizações envolvendo diferentes práticas para a projeção de cenários, análise de conteúdos provenientes de mídias e monitoramento do ambiente geral e setorial das organizações. A pesquisa apontou ainda as principais fontes e produtos de informação, perfil dos participantes e ferramentas utilizadas para a prática de Inteligência Competitiva no ambiente organizacional brasileiro. Conclusões: Embora as organizações adotem metodologias relativamente similares de Inteligência Competitiva, essa atividade apresenta objetivos distintos, afeitos tanto ao enfoque estratégico, quanto aos enfoques mercadológico, comercial e de vendas, prevalecendo o primeiro. O aspecto estratégico também está refletido nos modelos de subordinação hierárquica dominante das áreas de Inteligência Competitiva.

Estrategia educativa no ensino de anatomia humana aplicada à enfermagem

Directory of Open Access Journals (Sweden)

Raissa Cláudia Eufrázio de Oliveira

2018-01-01

Full Text Available Objetivo: avaliar a eficácia de uma estratégia educativa no ensino de anatomia humana aplicada à enfermagem. Metodologia: estudo descritivo, do tipo pré e pós-teste. A amostra foi composta por alunos do primeiro período do curso de enfermagem de uma universidade do nordeste do Brasil, durante o ano de 2014. A estratégia educativa foi composta por aulas expositivas dialogadas, com a utilização de casos clínicos. Resultados: foram abordados os seguintes conteúdos: miologia e aplicações intramusculares; sistema nervoso e reflexos; sistema cardiovascular, punção venosa e pressão arterial; sistema geniturinário, exame ginecológico e sondagem vesical. Verificou-se evolução quantitativa no período pós-teste em todas as aulas da estratégia educativa. Conclusão: a estratégia educativa foi considerada positiva, expressa pelo número de acertos no pós-teste e por associações estatísticas significativas. Destaca-se ainda a contribuição dessa estratégia no processo de formação crítica e reflexiva dos futuros enfermeiros.

Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

Directory of Open Access Journals (Sweden)

Julián Rodrigo Quintero

2011-03-01

Full Text Available Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una herramienta práctica para complementar los procedimientos de campo y optimizar los procesos y análisis de resultados orientados a identificar, caracterizar y cuantificar las variables relacionadas con el desarrollo del fenómeno del tránsito y la actividad del transporte.

La prensa escrita en México frente al cambio de régimen

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Eva Salgado Andrade

2007-01-01

Full Text Available Este artículo aborda el discurso de la prensa escrita para encontrar evidencias sobre los elementos lingüísticos y semióticos para recrear la realidad, funcionar como intermediaria entre diversos actores sociales o convertirse, ella misma, en actor político. El análisis abarca todos los materiales publicados entre el 3 y el 7 de julio del 2000 en diez periódicos de circulación nacional, en torno a los resultados electorales: 838 notas, editoriales, artículos, columnas, entrevistas y reportajes. La selección obedece a que, luego de las elecciones presidenciales en México, se consiguió captar masivamente la atención de la opinión pública, al suponer que con este resultado se hacía posible la alternancia política en México y terminaban siete décadas de hegemonía del Partido Revolucionario Institucional (PRI. Por medio de una metodología original aplicada al análisis de un corpus exhaustivo, se demuestra la utilidad de las perspectivas interdisciplinarias para la investigación en ciencias sociales.

La investigación cualitativa aplicada al estudio del nacionalismo: el discurso neoespañolista

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HELENA BÉJAR

2007-01-01

Full Text Available El siguiente artículo es parte de una investigación cualitativa de diecisiete grupos sobre «Nacionalismo y sentido de pertenencia: nacionalismo español, catalán y vasco». Se analiza aquí lo que llamo discurso neoespañolista, caracterizado por establecer una crítica del nacionalismo tanto en su versión españolista como en la de las naciones sin Estado y la apertura a un discurso cívico-republicano. Dicho discurso reivindica la noción de ciudadanía frente a la de pertenencia, propia del lenguaje político nacionalista. El artículo se aproxima, en primer lugar, a la concepción que los participantes en cinco grupos de discusión ofrecen sobre la comprensión de España como Estado, no como nación, enmarcando dicha concepción a lo largo de las últimas décadas. En segundo lugar se estudian los sentidos que se dan a la identidad española. En tercer y último lugar se analizan las formas de contestación política que se juzgan necesarios frente al progreso del llamado nacionalismo periférico.

COMPOSIÇÃO IDEAL DA SOLUÇÃO FILMOGÊNICA ADICIONADA DE PREBIÓTICO, APLICADA EM UVAS ‘THOMPSON’

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IURI MIRA

2015-06-01

Full Text Available A aplicação de coberturas comestíveis em frutas e hortaliças deve ser precedida de testes que busquem a formulação que melhor se adapta àquele produto. O objetivo deste trabalho foi determinar a composição ideal da cobertura comestível à base de cera de carnaúba adicionada de prebiótico a ser aplicada em uvas variedade Thompson, armazenadas sob refrigeração. Após a seleção, os frutos foram higienizados e procedeu-se à aplicação de soluções aquosas de cera de carnaúba adicionadas de Fruto-oligossacarídeo (FOS. Foram testadas treze formulações, utilizando as combinações de 50; 33; 25 e 0% (v/v de cera de carnaúba e 30; 20; 10 e 0% do FOS (p/v. Durante 25 dias, foram avaliados parâmetros de textura, físicoquímicos e físicos. Os parâmetros de textura avaliados sofreram alterações durante o período do estudo, mas sem evidências de terem sofrido interferência das coberturas aplicadas. As formulações que se mostraram mais promissoras para futuras aplicações comerciais foram dos tratamentos B (50% de cera, 20% de FOS, K (25% de cera, 10% de FOS e L (25% de cera, 0% de FOS.

Two-dimensional electron and hole gases in GaN/AlGaN heterostructures; Zweidimensionale Elektronen- und Loechergase in GaN/AlGaN-Heterostrukturen

Energy Technology Data Exchange (ETDEWEB)

Link, A.

2004-12-01

The aim of this PhD thesis is to investigate the electronic properties of electron and hole gases in GaN/AlGaN heterostructures. Particularly, a deeper and broadened understanding of scattering mechanisms and transport properties is in the focus of this work. The main experimental techniques used for this purpose are the study of Shubnikov-de Haas (SdH) effect and Hall measurements at low temperatures. By means of these magnetotransport measurements, a series of GaN/AlGaN heterostructures with different Al content of the AlGaN barrier were investigated. Since the sheet carrier density of the 2DEG in these semiconductor structures is strongly dependent on the Al content (n{sub s}=2 x 10{sup 12}-10{sup 13} cm{sup -2}), the variation of transport parameters was determined as a function of sheet carrier concentration. First, from the temperature dependence of the SdH oscillations the effective transport mass was calculated. A Hall bar structure with an additional gate contact was used as an alternative to tune the carrier density of a 2DEG system independent of varying structural parametes such as Al content. Thus, the scattering mechanisms were investigated in the carrier density region between 3 x 10{sup 12} and 9.5 x 10{sup 12} cm{sup -2}. The transport properties of subband electrons were studied for a 2DEG system with two occupied subbands. (orig.)

Current transport mechanisms in lattice-matched Pt/Au-InAlN/GaN Schottky diodes

Energy Technology Data Exchange (ETDEWEB)

Ren, Jian; Yan, Dawei, E-mail: daweiyan@jiangnan.edu.cn; Yang, Guofeng; Wang, Fuxue; Xiao, Shaoqing; Gu, Xiaofeng [Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122 (China)

2015-04-21

Lattice-matched Pt/Au-In{sub 0.17}Al{sub 0.83}N/GaN hetreojunction Schottky diodes with circular planar structure have been fabricated and investigated by temperature dependent electrical measurements. The forward and reverse current transport mechanisms are analyzed by fitting the experimental current-voltage characteristics of the devices with various models. The results show that (1) the forward-low-bias current is mainly due to the multiple trap-assisted tunneling, while the forward-high-bias current is governed by the thermionic emission mechanism with a significant series resistance effect; (2) the reverse leakage current under low electric fields (<6 MV/cm) is mainly carried by the Frenkel-Poole emission electrons, while at higher fields the Fowler-Nordheim tunneling mechanism dominates due to the formation of a triangular barrier.

Experiencias y recursos con las tics para la atención al alumnado con necesidades educativas especiales

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Eladio Sebastian Heredero

2014-02-01

Full Text Available Este trabajo tiene como objetivo levantar algunas experiencias llevadas a cabo en centros educativos en los que se ponen de manifiesto buenas prácticas con el uso de las tecnologías para la atención al alumnado con necesidades educativas. Se ha realizado a través de una metodología mixta que alterna el trabajo de investigación de campo con el análisis documental, para finalmente llegar a presentar algunos ejemplos clarificadores y eficaces de prácticas educativas concretas. Los ejemplos aquí aportados, tienen como innovación, que nos presentan prácticas de aula, testadas y aplicadas, y a partir de ellas poder establecer algunas conclusiones e ideas para su mejora.

Direct in situ transmission electron microscopy observation of Al push up during early stages of the Al-induced layer exchange

International Nuclear Information System (INIS)

Birajdar, B.I.; Antesberger, T.; Butz, B.; Stutzmann, M.; Spiecker, E.

2012-01-01

The mechanism of Al transport during Al-induced layer exchange and crystallization of amorphous Si (a-Si) has been investigated by in situ and analytical transmission electron microscopy. Significant grain boundary realignment and coarsening of Al grains close to the Si crystallization growth front as well as push up of excess Al into the a-Si layer at distances even a few micrometers away from the crystallization front were observed. Stress-mediated diffusion of Al is postulated to explain the experimental observations.

Frecuencia de los hongos asociados al desarrollo de mohos poscosecha en el pedúnculo de la piña en dos zonas de Costa Rica

OpenAIRE

Johanny Castro Chinchilla; Gerardina Umaña Rojas

2017-01-01

La piña es uno de los principales cultivos de exportación en Costa Rica y la presencia de moho en el pedúnculo afecta su calidad en los mercados internacionales. El objetivo de esta investigación fue determinar en frutos de piña, en la cera aplicada sobre la fruta y en el aire de las cámaras de enfriamiento, la frecuencia de los principales hongos asociados al desarrollo de mohos en el pedúnculo. Se realizó un muestreo mensual de abril de 2012 a marzo de 2013 en empacadoras de Sarapiquí y Pun...

Frecuencia de los hongos asociados al desarrollo de mohos poscosecha en el pedúnculo de la piña en dos zonas de Costa Rica

OpenAIRE

Castro Chinchilla, Johanny; Umaña Rojas, Gerardina

2017-01-01

ResumenLa piña es uno de los principales cultivos de exportación en Costa Rica y la presencia de moho en el pedúnculo afecta su calidad en los mercados internacionales. El objetivo de esta investigación fue determinar en frutos de piña, en la cera aplicada sobre la fruta y en el aire de las cámaras de enfriamiento, la frecuencia de los principales hongos asociados al desarrollo de mohos en el pedúnculo. Se realizó un muestreo mensual de abril de 2012 a marzo de 2013 en empacadoras de Sarapiqu...

Transporte frigorífico internacional de fruta: intermodalidad y sistemas de transporte inteligente

OpenAIRE

Barreiro Elorza, Pilar; Robla Villalba, José Ignacio

2004-01-01

n el año 2001 la UE presentó el Libro Blanco del Transporte en el que se plantea la necesidad acuciante de fomentar los medios de transporte alternativos al transporte por carretera: transporte marítimo, ferroviario y fluvial, especialmente de cara a la ampliación europea. En este artículo se revisan los conceptos de Intermodalidad y Sistemas de Transporte Inteligentes tal y como los define la UE. Se presentan también los resultados de un seguimiento de transporte marítimo intercontinental ll...

Chemical failure modes of AlQ3-based OLEDs: AlQ3 hydrolysis.

Science.gov (United States)

Knox, John E; Halls, Mathew D; Hratchian, Hrant P; Schlegel, H Bernhard

2006-03-28

Tris(8-hydroxyquinoline)aluminum(III), AlQ3, is used in organic light-emitting diodes (OLEDs) as an electron-transport material and emitting layer. The reaction of AlQ3 with trace H2O has been implicated as a major failure pathway for AlQ3-based OLEDs. Hybrid density functional calculations have been carried out to characterize the hydrolysis of AlQ3. The thermochemical and atomistic details for this important reaction are reported for both the neutral and oxidized AlQ3/AlQ3+ systems. In support of experimental conclusions, the neutral hydrolysis reaction pathway is found to be a thermally activated process, having a classical barrier height of 24.2 kcal mol(-1). First-principles infrared and electronic absorption spectra are compared to further characterize AlQ3 and the hydrolysis pathway product, AlQ2OH. The activation energy for the cationic AlQ3 hydrolysis pathway is found to be 8.5 kcal mol(-1) lower than for the neutral reaction, which is significant since it suggests a role for charge imbalance in promoting chemical failure modes in OLED devices.

Charge-transport in Josephson-junctions with ferromagnetic Ni3Al-interlayer

International Nuclear Information System (INIS)

Born, F.

2006-01-01

The present dissertation reports on experimental studies about superconducting coupling through a thin Ni 76 Al 24 film. A new patterning process has been developed, which allows in combination with the wedge shaped deposition technique the in situ deposition of 20 single Nb/Al/Al 2 O 3 /Ni 3 Al/Nb multilayers, each with its own well defined Ni 3 Al thickness. Every single multilayer consists of 10 different sized Josephson junctions, showing a high reproducibility and scaling with its junction area. Up to six damped oscillations of the critical current density against F-layer thickness were observed, revealing three single 0-π-transitions in the ground state of Josephson junctions. Contrary to former experimental studies, the exponential decay length is one magnitude larger than the oscillation period defining decay length. The theoretical predictions based on linearised Eilenberger equations results in excellent agreement of theory and experimental results. (orig.)

Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

Directory of Open Access Journals (Sweden)

Julián Rodrigo Quintero

2011-11-01

Full Text Available Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una herramienta práctica para complementar los procedimientos de campo y optimizar los procesos y análisis de resultados orientados a identificar, caracterizar y cuantificar las variables relacionadas con el desarrollo del fenómeno del tránsito y la actividad del transporte.

Transport Equations for CAD Modeling of Al(x)Ga(1-x)N/GaN HEMTs

Science.gov (United States)

Freeman, Jon C.

2003-01-01

BEMTs formed from Al(x)Ga(1-x)N/GaN heterostructures are being investigated for high RF power and efficiency around the world by many groups, both academic and industrial. In these devices, the 2DEG formation is dominated by both spontaneous and piezoelectric polarization fields, with each component having nearly the same order of magnitude. The piezoelectric portion is induced by the mechanical strain in the structure, and to analyze these devices, one must incorporate the stress/strain relationships, along with the standard semiconductor transport equations. These equations for Wurtzite GaN are not easily found in the open literature, hence this paper summarizes them, along with the constitutive equations for piezoelectric materials. The equations are cast into the format for the Wurtzite crystal class, which is the most common way GaN is grown epitaxially.

An InDel in the Promoter of Al-ACTIVATED MALATE TRANSPORTER9 Selected during Tomato Domestication Determines Fruit Malate Contents and Aluminum Tolerance[OPEN

Science.gov (United States)

Wang, Xin; Hu, Tixu; Zhang, Fengxia; Wang, Bing; Li, Changxin; Yang, Tianxia; Li, Hanxia; Lu, Yongen; Ye, Zhibiao

2017-01-01

Deciphering the mechanism of malate accumulation in plants would contribute to a greater understanding of plant chemistry, which has implications for improving flavor quality in crop species and enhancing human health benefits. However, the regulation of malate metabolism is poorly understood in crops such as tomato (Solanum lycopersicum). Here, we integrated a metabolite-based genome-wide association study with linkage mapping and gene functional studies to characterize the genetics of malate accumulation in a global collection of tomato accessions with broad genetic diversity. We report that TFM6 (tomato fruit malate 6), which corresponds to Al-ACTIVATED MALATE TRANSPORTER9 (Sl-ALMT9 in tomato), is the major quantitative trait locus responsible for variation in fruit malate accumulation among tomato genotypes. A 3-bp indel in the promoter region of Sl-ALMT9 was linked to high fruit malate content. Further analysis indicated that this indel disrupts a W-box binding site in the Sl-ALMT9 promoter, which prevents binding of the WRKY transcription repressor Sl-WRKY42, thereby alleviating the repression of Sl-ALMT9 expression and promoting high fruit malate accumulation. Evolutionary analysis revealed that this highly expressed Sl-ALMT9 allele was selected for during tomato domestication. Furthermore, vacuole membrane-localized Sl-ALMT9 increases in abundance following Al treatment, thereby elevating malate transport and enhancing Al resistance. PMID:28814642

Rating adab: al-Tawḥīdīon the merits of poetry and prose. The 25^th night of the Kitāb al-imtā' wa-l-mu'ānasa, translation and commentary

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Hachmeier, Klaus

2004-12-01

Full Text Available Abū Ḥayyān al-Tawḥīdī (d. 414/1023 actively contributed to the rich and diverse debate that took place in all fields of adab in the middle Abbasid period. In the 25th night of this Kitāb al-imtā‘ wal-l-mu’ ānasa, al-Tawḥīdī talks about the respective virtues of poetry and prose. This highly entertaining debate, where jest and earnest (jidd wa-hazl are skillfully interwoven, also stands under the influence of Aristotelian ideas that were applied to literary theory. The article offers a commented translation with references to other contemporary sources.

Abū Ḥayyān al-Tawḥīdī (m. 414/1023 contribuyó activamente al rico y variado debate que se produjo en todos los ámbitos del adab hacia mediados del periodo 'abbāsí. En la noche 25 de su Kitāb al-imtā‘ wal-l-mu’ ānasa, al-Tawḥīdī habla acerca de los méritos respectivos de la poesía y de la prosa. Este entretenido debate, en el que lo humorístico y lo serio (ŷidd wa-hazl están estrechamente entrelazados, también muestra la influencia de las ideas aristotélicas que fueron aplicadas a la teoría literaria. Este artículo ofrece una traducción comentadas con referencias a otras fuentes contemporáneas.

Modelagem matemática aplicada a síntese do biodiesel a partir de gordura animal e óleo vegetal

OpenAIRE

Letícia Thaís Chendynski

2015-01-01

O baixo custo e a alta disponibilidade da gordura animal está gerando interesse industrial na sua utilização em conjunto com o óleo de soja para a produção de biodiesel, diminuindo custos e maximizando o lucro. Atualmente, o delineamento de experimentos é uma tecnologia aplicada para se conseguir um produto de excelência, otimizando sistemas e processos, reduzindo custos e solucionando eventuais problemas de fabricação Esse trabalho teve como objetivo a aplicação do delineamento experimental ...

Drivers of South African transport and transport infrastructure

CSIR Research Space (South Africa)

Rust, FC

2009-01-01

Full Text Available There is no doubt that infrastructure in general and specifically transport infrastructure plays a major role in economic development (Weisbrod G 1997, Chapman P et al 2002) as well as in social development (UNCDF 2007). In addition, construction...

OBSERVATORIO DE COSTES Y FINANCIACIÓN DEL TRANSPORTE URBANO COLECTIVO: UN PROGRAMA DE INVESTIGACIÓN

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Sánchez Toledano, Daniel

2014-01-01

Full Text Available El Observatorio de Costes y Financiación del Transporte Urbano Colectivo y sus informes anuales sobre el sector constituyen una excelente plataforma para mejorar el conocimiento de su estructura de costes, posibilitar prácticas de benchmarking a las operadoras y orientar políticas para una financiación eficiente del servicio. Constituye objetivo principal del presente trabajo divulgar el contenido y la estructura del Informe delObservatorio de Costes y Financiación del Transporte Urbano Colectivo 2008-2009, el universo poblacional objeto de estudio y la metodología aplicada tanto para la selección de la muestra analizada como para la definición de los indicadores analizados. Por último, se esbozan algunas propuestas para identificación de itinerarios de investigación de los aspectos críticos para una gestión eficiente y sostenible del servicio y se presentan las principales conclusiones del trabajo.

Primera red sudamericana de biomedicina. investigación, educación y biotecnología aplicadas a la salud

OpenAIRE

Perone, Marcelo Javier; Velázquez, Graciela; Rojas de Arias, Antonieta; Chamorro, Gustavo; Coluchi, Norma; Pirmez, Claude; Savino, Wilson; Barbeito, Luis; Arzt, Eduardo Simon

2017-01-01

Se da a conocer la creación del primer programa de integración regional de una red de Institutos de Investigación en Biomedicina pertenecientes a países miembros del MERCOSUR. Se analizan las bases que dieron sustento a su creación y sus objetivos en el mediano y largo plazo. Además, se estima el potencial de los resultados de este programa en los campos de la investigación médica aplicada, educación y biotecnología. Fil: Perone, Marcelo Javier. Consejo Nacional de Investigaciones Cien...

El Instituto Navarro de Administración Pública y el desarrollo de la Psicología Aplicada en Navarra

OpenAIRE

JESÚS RAMÓN LOITEGUI ALDAZ

2007-01-01

El presente trabajo muestra el desarrollo orgánico del Instituto de Psicología Aplicada de Navarra, creado en 1961, hasta convertirse en la actualidad en el Instituto Navarro de Administración Pública y su vinculación con la aplicación de la Psicología en Navarra. Finalizando la década de los años 60 las funciones propias del Instituto eran la orientación profesional, la selección profesional, la asistencia psiquiátrica y la investigación y promoción de la Psicología. Estas funciones se lleva...

Tendencias en investigación sobre seguridad y salud laboral: Propuesta metodológica aplicada al sector de la construcción Trends in research about occupational safety and health: Methodology applied to the construction industry

Directory of Open Access Journals (Sweden)

Gloria Isabel Carvajal Peláez

2009-07-01

Full Text Available En este artículo se realiza un análisis de las tendencias en investigación sobre seguridad y salud ocupacional aplicadas al sector de la construcción. Se investigaron fuentes publicadas en inglés (1930 -2007 y se encontraron más de 250 artículos. Para clasificar la información, se propone el "ciclo riesgo accidente" formado por cinco pasos que reflejan la realidad de la seguridad laboral en la construcción. Para cada paso, se seleccionaron las publicaciones más representativas y se elaboraron árboles de evolución lógica teniendo en cuenta el contenido, grado de importancia, orden cronológico, aplicación sobre cada tema, etc. Con estos árboles, se pasa de lo general a lo particular en forma cronológica, para demostrar las tendencias actuales en investigación en seguridad y salud en la construcción y podemos concluir que la investigación en este aspecto sigue siendo escasa, tratándose de un campo lleno de oportunidades y con un futuro prometedor.This article analyzes trends in research in occupational safety and health applied to the construction industry. The sources of information published in English (1930-2007 and found more than 250 articles. In order to classify these documents, is proposed the "risk-accident cycle" composes by five steps that reflect the reality of occupational safety and health in the construction industry. For each one of them, the papers more representative were selected and later elaborated a tree of chronological evolution considering aspects such as the content, degree of importance, chronological order, application on each subject, etc. With the elaboration of these trees, show the passage of the general to the particular in chronological form, for demonstrating the actual trends in research in safety and health in the construction. As a final remark, nowadays, research in safety and health in the construction is still very limited, being a field with many opportunities and a promising future.

Growth of CdTe: Al films; Crecimiento de peliculas de CdTe: Al

Energy Technology Data Exchange (ETDEWEB)

Gonzalez A, M.; Zapata T, M. [CICATA-IPN, 89600 Altamira, Tamaulipas (Mexico); Melendez L, M. [CINVESTAV-IPN, A.P. 14-740, 07000 Mexico D.F. (Mexico); Pena, J.L. [CINVESTAV-IPN, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico)

2006-07-01

CdTe: AI films were grown by the close space vapor transport technique combined with free evaporation (CSVT-FE). The Aluminum (Al) evaporation was made by two kinds of sources: one made of graphite and the other of tantalum. The films were deposited on glass substrates. The Al source temperature was varied maintaining the CdTe source temperature fixed as well as the substrate temperature. The films were characterized by x-ray energy dispersive analysis (EDAX), x-ray diffraction and optical transmission. The results showed for the films grown with the graphite source for Al evaporation, the Al did not incorporate in the CdTe matrix, at least to the level of EDAX sensitivity; they maintained the same crystal structure and band gap. For the samples grown with the tantalum source, we were able to incorporate the Al. The x-ray diffraction patterns show that the films have a crystal structure that depends on Al concentration. They were cubic up to 2.16 at. % Al concentration; for 19.65 at. % we found a mixed phase; for Al concentration higher than 21 at. % the films were amorphous. For samples with cubic structure it was found that the lattice parameter decreases and the band gap increases with Al concentration. (Author)

Ciencia básica y ciencia aplicada Basic science and applied science

Directory of Open Access Journals (Sweden)

Ruy Pérez-Tamayo

2001-08-01

Full Text Available En el contexto de una intervención en el Foro de Consulta Democrática de la Coordinación de los Institutos Nacionales de Salud sobre Enseñanza e Investigación en Salud, realizado en el Instituto Nacional de Cardiología Ignacio Chávez, se hace una revisión crítica de la clasificación convencional de la ciencia en básica y aplicada; además, se analiza lo que deberían ser la enseñanza y la investigación en salud. Para apoyar su propia clasificación de la ciencia en "bien hecha", la cual "genera conocimientos verificables sobre la realidad" y la "mal hecha", improductiva o productora de "puras mentiras" y "no debe patrocinarse", el autor revisa las definiciones utilitaristas y peyorativas como las que establecen ciencia comprometida y ciencia pura, ciencia útil y ciencia inútil, y ciencia práctica y ciencia esotérica, como sinónimos de ciencia aplicada y ciencia básica y afirma que, en México, esta diferenciación "para lo único que ha servido en el pasado es para justificar la reducción en el apoyo oficial a la ciencia básica, porque no estaba dirigida a resolver ´los problemas nacionales´o porque no caía en las prioridades establecidas en ese sexenio". En cuanto a educación e investigación en salud reconoce que el programa actual de formación de investigadores tiene una eficiencia muy baja y propone un estudio científico crítico, realizado por un equipo de especialistas, interdisciplinario, "para integrar la carrera del investigador científico desde la captura de la juventud inteligente hasta la jubilación o muerte del investigador" y para el cual la evaluación de la eficiencia del apoyo a sus proyectos de investigación no se restrinja a si se publicó o no un artículo "pues la calidad del trabajo científico y la contribución de un investigador al desarrollo de la ciencia no es nada más el número de sus publicaciones". El texto completo en inglés de este artículo está disponible en: http

Transporte intra-hospitalar de pacientes adultos em estado crítico: complicações relacionadas à equipe, equipamentos e fatores fisiológicos Transporte intrahospitalario de pacientes adultos en estado crítico: complicaciones relacionadas al equipo, equipamientos y factores fisiológicos Intra-hospital transport of critically ill adult patients: complications related to staff, equipment and physiological factors

Directory of Open Access Journals (Sweden)

Ana Carolina Goulardins de Almeida

2012-01-01

Full Text Available OBJETIVO: Identificar na literatura as complicações relacionadas às alterações fisiológicas do paciente, à equipe multidisciplinar e ao uso de equipamentos durante o transporte intra-hospitalar de pacientes críticos. MÉTODOS: Revisão integrativa da literatura, com busca nas bases de dados PUBMED, MEDLINE, e LILACS. RESULTADOS: Foram encontrados 20 artigos, todos escritos na língua inglesa. Os estudos mostraram que as alterações na pressão arterial e na frequência cardíaca são as mais comuns durante o transporte. Dos eventos adversos relacionados a problemas com a equipe, destacaram-se, a falta de conhecimento do profissional e a falha de comunicação, além dos provenientes dos equipamentos utilizados. CONCLUSÃO: Transportar o paciente crítico de maneira segura significa melhorar a comunicação entre as equipes, padronizar as ações e equipamentos utilizados por meio de protocolos e identificar intercorrências para obter excelência no atendimento durante o transporte.OBJETIVO: Identificar en la literatura las complicaciones relacionadas a las alteraciones fisiológicas del paciente, al equipo multidisciplinario y al uso de equipamientos durante el transporte intrahospitalario de pacientes críticos. MÉTODOS: Revisión integrativa de la literatura, con búsqueda en las bases de datos PUBMED, MEDLINE, y LILACS. RESULTADOS: Fueron encontrados 20 artículos, todos escritos en el idioma inglés. Los estudios mostraron que las alteraciones en la presión arterial y en la frecuencia cardíaca son las más comunes durante el transporte. De los eventos adversos relacionados a problemas con el equipo, se destacaron, la falta de conocimiento del profesional y la falla en la comunicación, además de los provenientes de los equipamientos utilizados. CONCLUSIÓN: Transportar al paciente crítico de manera segura significa mejorar la comunicación entre los equipos, patronizar las acciones y equipamientos utilizados por medio de

Tonoplast- and plasma membrane-localized aquaporin-family transporters in blue hydrangea sepals of aluminum hyperaccumulating plant.

Directory of Open Access Journals (Sweden)

Takashi Negishi

Full Text Available Hydrangea (Hydrangea macrophylla is tolerant of acidic soils in which toxicity generally arises from the presence of the soluble aluminum (Al ion. When hydrangea is cultivated in acidic soil, its resulting blue sepal color is caused by the Al complex formation of anthocyanin. The concentration of vacuolar Al in blue sepal cells can reach levels in excess of approximately 15 mM, suggesting the existence of an Al-transport and/or storage system. However, until now, no Al transporter has been identified in Al hyperaccumulating plants, animals or microorganisms. To identify the transporter being responsible for Al hyperaccumulation, we prepared a cDNA library from blue sepals according to the sepal maturation stage, and then selected candidate genes using a microarray analysis and an in silico study. Here, we identified the vacuolar and plasma membrane-localized Al transporters genes vacuolar Al transporter (VALT and plasma membrane Al transporter 1 (PALT1, respectively, which are both members of the aquaporin family. The localization of each protein was confirmed by the transient co-expression of the genes. Reverse transcription-PCR and immunoblotting results indicated that VALT and PALT1 are highly expressed in sepal tissue. The overexpression of VALT and PALT1 in Arabidopsis thaliana conferred Al-tolerance and Al-sensitivity, respectively.

Electrical transport properties of calcium and barium aluminates

NARCIS (Netherlands)

Metselaar, R.; Hoefsloot, A.M.

1987-01-01

Electrical conductivity and ionic transport numbers have been measured of barium and calcium aluminates with composition CaO·nAl2O3 (n=7/12, 1, 2, 6) and 0.82 BaO·6Al2O3. At room temperatures these compounds are insulators, but at high temperatures mixed conductivity is observed. Ionic transport

Realidad aumentada aplicada al patrimonio histórico molinar

Directory of Open Access Journals (Sweden)

Miguel Castro García

2011-04-01

Full Text Available The development of computer tools in the last decade is indisputable evidence that is allowing perceive reality more fully through different techniuqes, such as the Augmented Reality (AR. Taking as a starting point Augmented Reality technology, this study seeks to support the implementation of milling heritage knowledge and its application to the recovery of the Windmills of Andalusia (Spain. In this way, ensures that the visitor gets a more pleasant experience when interpreting the remains and the operation of these windmills' owm pre-industrial archaeology.

Herramienta web para calcular el impacto radiologico asociado al transporte de residuos radiactivos al ATC

OpenAIRE

Calleja Rubio, Jose Antonio; Gutierrez Martin, Fernando; Colón Hernández, Cristobal

2012-01-01

Técnicos de TECNATOM, S.A. e Investigadores de la (UPM), han desarrollado un programa para analizar la logística y los impactos potenciales del transporte por carretera de materiales radiactivos en España. El transporte de materiales radiactivos es un tema de renovado interés en nuestro país debido a la creciente movilidad que cabe esperar, sobre todo tras la entrada en operación del almacén temporal centralizado (ATC) previsto para los próximos años. Este almacén está destinado a resi...

Magnetic and transport properties of amorphous Ce-Al alloy

Science.gov (United States)

Amakai, Yusuke; Murayama, Shigeyuki; Momono, Naoki; Takano, Hideaki; Kuwai, Tomohiko

2018-05-01

Amorphous (a-)Ce50Al50 has been prepared by DC high-rate sputter method. The structure of the obtained sample has been confirmed to have an amorphous structure because there are no Bragg peaks in the X-ray diffraction measurement and have a clear exothermic peak by the differential scanning calorimetry measurement. We have measured the resistivity ρ, magnetic susceptibility χ, specific heat Cp and thermoelectric power S for a-Ce50Al50. The temperature dependence of ρ exhibits a small temperature dependence less than 10% in the whole temperature region. χ follows a Curie-Weiss behavior in the high-temperature region of T>90 K. The effective paramagnetic moment peff, estimated from C is 2.18 μB/Ce-atom. The low-temperature Cp/T increases rapidly with decreasing temperature and tends to a saturation. S(T) exhibits negative values in a wide temperature region. A minimum of S appear at around 60 K, and S decreases linearly with decreasing temperature down to 10 K. The low-temperature S is almost 0 μV/K down to 2 K. From these results, we have pointed out that present a-Ce50Al50 would be an incoherent Kondo material.

Espectroscopia de admitancias de banda ancha aplicada al control microestructural de propiedades eléctricas en varistores cerámicos

Directory of Open Access Journals (Sweden)

Fernández Hevia, D.

2004-06-01

Full Text Available In the present work, the theory of charge transport through active interfaces is used to study the electronic properties of ZnO-based varistors. It has been observed that for a certain range of sintering temperatures the microscopic electrical response of the material is constant, so that the macroscopic response is microstructure controlled. This allows controlling the functional response of the material with a high precision.

En el presente estudio se utiliza la teoría de transporte de carga a través de interfases eléctricamente activas para estudiar las propiedades electrónicas de varistores basados en ZnO. Se obtiene un rango de temperaturas de sinterización en el que la respuesta eléctrica microscópica del material se mantiene esencialmente constante, de manera que su respuesta macroscópica está controlada por su microestructura. Esto permite una gran precisión en el control de las propiedades eléctricas funcionales del material.

De la empresa al mercado: la desintegración vertical del transporte terrestre en España

Directory of Open Access Journals (Sweden)

Compés López, Raúl

2005-12-01

Full Text Available Las empresas españolas recurren cada vez más a la subcontratación del servicio de transporte terrestre. Este modelo es el resultado de un proceso de desintegración vertical que lleva a vender los vehículos y a reubicar a los trabajadores dentro o fuera de la empresa. Las reformas del marco institucional que regula la prestación de este servicio, y las normas fiscales, contractuales y sociales que afectan los costos y beneficios de la prestación del servicio inciden de manera diferente en los distintos tipos de empresas. La desintegración vertical genera costos de salida que afectan al ritmo, la estrategia y el resultado del cambio del modelo organizativo.

Use of environmental isotope techniques in studying surface and groundwaters in the Damascus basin (Al-Ghotta): A case study of geochemical modeling of elements and pollutants transport

International Nuclear Information System (INIS)

Kattan, Z.

2004-09-01

This work discuses in details the hydrochemical and isotopic characteristics of surface and groundwaters in the Damascus Ghotta basin. In addition, it deals with the chemical and isotopic compositions of rainfall of some surrounding stations (Damascus, Bloudan, Arneh, Al-Kounietra, Izraa, Al-Souweida, Homs and Tartous). The objective of this research was to make new assessment of the available water resources in this basin, together with conducting essays to model geochemically the elements and pollutants transport in the groundwater, by the use of PHREEQM code.(author)

A novel method for trace tritium transport studies

International Nuclear Information System (INIS)

Bonheure, Georges; Mlynar, Jan; Murari, A.; Giroud, C.; Popovichev, S.; Belo, P.; Bertalot, L.

2009-01-01

A new method combining a free-form solution for the neutron emissivity and the ratio method (Bonheure et al 2006 Nucl. Fusion 46 725-40) is applied to the investigation of tritium particle transport in JET plasmas. The 2D neutron emissivity is calculated using the minimum Fisher regularization method (MFR) (Anton et al 1996 Plasma Phys. Control. Fusion 38 1849, Mlynar et al 2003 Plasma Phys. Control. Fusion 45 169). This method is being developed and studied alongside other methods at JET. The 2D neutron emissivity was significantly improved compared with the first MFR results by constraining the emissivity along the magnetic flux surfaces. 1D profiles suitable for transport analysis are then obtained by subsequent poloidal integration. In methods on which previous JET publications are based (Stork et al 2005 Nucl. Fusion 45 S181, JET Team (prepared by Zastrow) 1999 Nucl. Fusion 39 1891, Zastrow et al 2004 Plasma Phys. Control. Fusion 46 B255, Adams et al 1993 Nucl. Instrum. Methods A 329 277, Jarvis et al 1997 Fusion Eng. Des. 34-35 59, Jarvis et al 1994 Plasma Phys. Control. Fusion 36 219), the 14.07 MeV D-T neutron line integrals measurements were simulated and the transport coefficients varied until good fits were obtained. In this novel approach, direct knowledge of tritium concentration or the fuel ratio n T /n D is obtained using all available neutron profile information, e.g both 2.45 MeV D-D neutron profiles and 14.07 MeV D-T neutron profiles (Bonheure et al 2006 Nucl.Fusion 46 725-40). Tritium particle transport coefficients are then determined using a linear regression from the dynamic response of the tritium concentration n T /n D profile. The temporal and spatial evolution of tritium particle concentration was studied for a set of JET discharges with tritium gas puffs from the JET trace tritium experiments. Local tritium transport coefficients were derived from the particle flux equation Γ = -D∇n T + Vn T , where D is the particle diffusivity and V

Strongly capacitively coupled double quantum dots in GaAs-AlGaAs heterostructures. Preparation and electrical transport; Kapazitativ stark gekoppelte Doppelquantenpunkte in GaAs-AlGaAs-Heterostrukturen. Herstellung und elektrischer Transport

Energy Technology Data Exchange (ETDEWEB)

Huebel, A.

2007-11-22

In this work, a double quantum dot system is studied whose two dots are electrically insulated from one another and contacted independently with two leads. The geometry is optimized to maximize the capacitive interaction between the dots. The samples are characterized by electrical transport measurements in a dilution refrigerator. It is then studied at different tunnel couplings how the capacitive interaction influences the electrical transport in equilibrium. Under certain conditions correlated tunnel processes can be observed. A simple model is derived that serves to understand these processes. The double quantum dot system is defined in lateral arrangement by reactive ion etching of a two-dimensional electron system located only 50 nm below the surface of a GaAs-AlGaAs heterostructure. The samples are characterized in a dilution refrigerator at 25 mK near the common pinch-off point of all four tunnel barriers. A measurement of the differential equilibrium conductances of both quantum dots as a function of two gate voltages yields a honeycomb-like charge stability diagram. The most important sample characteristic is the ratio between the interaction capacitance and the total capacitance of a single quantum dot. For the optimized sample, this ratio turns out to be larger than one third near the common pinch-off point, with a single-dot charging energy of up to 800 {mu}eV. At more positive gate voltages, the capacitances between the quantum dots and their leads increase more and more, thereby diminishing the charging energy. It is shown for the optimized sample that all capacitance coefficients except the dot-lead capacitances are constant to within considerable accuracy over several Coulomb blockade oscillations. In order to measure correlated electrical transport in equilibrium, special parameter regions are examined in which the charges of both quantum dots cannot fluctuate independently of each other. An analytical formula is derived that describes the

Preface: Nonclassical Transport

International Nuclear Information System (INIS)

Bolshov, L.; Kondratenko, P.; Pruess, K.

2008-01-01

Transport phenomena in highly heterogeneous media can be dramatically different from those in homogeneous media and therefore are of great fundamental and practical interest. Anomalous transport occurs in semiconductor physics, plasma physics, astrophysics, biology, and other areas. It plays an especially important role in hydrogeology because it may govern the rate of migration and degree of dispersion of groundwater contaminants from hazardous waste sites. The series of four articles in this special section of Vadose Zone Journal is devoted to transport phenomena in heterogeneous media in the context of geologic disposal of radioactive waste. It contains the results of joint investigations performed at the Nuclear Safety Institute of the Russian Academy of Sciences and Lawrence Berkeley National Laboratory in California. The work was supported by the U.S. DOE (under Contract No. DEAC02-05CH11231). The problems addressed in this research involve a broad range of space and time scales and were approached using modern methods of theoretical and computational physics, such as scaling analysis and diagrammatic techniques used before in critical phenomena theory. Special attention is paid to the asymptotics of concentration behavior (concentration tails). This issue is exceptionally important for the reliability assessments of radioactive waste disposal because, depending on the structure of the tails, concentrations at large distances from the source can differ by many orders of magnitude. In the first paper of this special section, Bolshov et al. (2008b) present an overview of field and laboratory observations that demonstrate nonclassical flow and transport behavior in geologic media. It is recognized that natural fracture networks as a rule have fractal geometry and can be classified as percolation systems. This is one of the main factors giving rise to anomalous transport in geologic media. Another important factor is the presence of contaminant traps provided by

Cuestiones en torno al poderoso efecto de los videojuegos violentos: del neoconductismo a la cognición social

Directory of Open Access Journals (Sweden)

Roberto de Miguel Pascual

2012-04-01

Full Text Available Desde los años ochenta, el paradigma cognitivista domina la teoría y el examen empírico de los efectos de los contenidos mediáticos violentos sobre las actitudes y las conductas agresivas. No obstante, los enfoques basados en la psicología conductista, y más en concreto su énfasis en los principios de condicionamiento y aprendizaje, siguen vigentes en muchas escuelas científicosociales y en la investigación aplicada. En este artículo se discuten los avances que trae consigo la observación y el análisis de los comportamientos asociados al uso de videojuegos violentos a raíz de la incorporación de sus hallazgos a la literatura efectista.

La suspensión condicional del procedimiento aplicada en la Unidad Judicial Norte Nº 2 por el Cantón Guayaquil

OpenAIRE

Fierro Bosquez, Lincol Giovanny

2013-01-01

El tema de investigación trata sobre: “LA SUSPENSIÓN CONDICIONAL DEL PROCEDIMIENTO APLICADA EN LA UNIDAD JUDICIAL NORTE N° 2 POR EL CANTÓN GUAYAQUIL”, procedimientos penales y salidas alternativas que se pueden aplicar para mejorar y agilitar las actuaciones de los operadores de justicia. Política que fue expedida por el Consejo Consultivo de la Función Judicial y resuelta en la cesión del 15 de febrero del 2011, como aplicación prioritaria de las salidas alternativas y procedimientos especia...

Resolving the mystery of transport within internal transport barriers

Energy Technology Data Exchange (ETDEWEB)

Staebler, G. M.; Belli, E. A.; Candy, J.; Waltz, R. E.; Greenfield, C. M.; Lao, L. L.; Smith, S. P. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Kinsey, J. E. [CompX, P.O. Box 2672, Del Mar, California 92014-5672 (United States); Grierson, B. A. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Chrystal, C. [University of California-San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States)

2014-05-15

The Trapped Gyro-Landau Fluid (TGLF) quasi-linear model [G. M. Staebler, et al., Phys. Plasmas 12, 102508 (2005)], which is calibrated to nonlinear gyrokinetic turbulence simulations, is now able to predict the electron density, electron and ion temperatures, and ion toroidal rotation simultaneously for internal transport barrier (ITB) discharges. This is a strong validation of gyrokinetic theory of ITBs, requiring multiple instabilities responsible for transport in different channels at different scales. The mystery of transport inside the ITB is that momentum and particle transport is far above the predicted neoclassical levels in apparent contradiction with the expectation from the theory of suppression of turbulence by E×B velocity shear. The success of TGLF in predicting ITB transport is due to the inclusion of ion gyro-radius scale modes that become dominant at high E×B velocity shear and to improvements to TGLF that allow momentum transport from gyrokinetic turbulence to be faithfully modeled.

COMPOSIÇÃO IDEAL DA SOLUÇÃO FILMOGÊNICA ADICIONADA DE PREBIÓTICO, APLICADA EM UVAS ‘THOMPSON’

OpenAIRE

IURI MIRA; CELSO DUARTE CARVALHO FILHO; DENISE NUNES VIOLA

2015-01-01

A aplicação de coberturas comestíveis em frutas e hortaliças deve ser precedida de testes que busquem a formulação que melhor se adapta àquele produto. O objetivo deste trabalho foi determinar a composição ideal da cobertura comestível à base de cera de carnaúba adicionada de prebiótico a ser aplicada em uvas variedade Thompson, armazenadas sob refrigeração. Após a seleção, os frutos foram higienizados e procedeu-se à aplicação de soluções aquosas de cera de carnaúba adicionadas de Fruto-olig...

Aplicación de los sistemas de separación hidráulica y magnética al reciclado de los residuos de construcción y demolición

OpenAIRE

Rodríguez-Avello Sanz, Ángel; Gómez-Limón, Dulce; Peña Narciso, Christian; Fueyo, Luis

2013-01-01

En el presente estudio se analizan las últimas técnicas aplicadas al reciclaje de los residuos de construcción y demolición (RCD), en los que además de los sistemas clásicos de estrio manual y mecánico, trituración y clasificación granulométrica se introducen los equipos de separación hidráulica (clasificadores de banda y tornillos sin fin) y los de pulsación por corriente turbulenta de acción diferencial (Jig). De igual forma los áridos reciclados ganan en calidad cuando se someten a pro...

Análisis acústico del llanto del niño recién nacido orientado al diagnóstico de patología en su neurodesarrollo debido a hipoxia

OpenAIRE

Escobedo Beceiro, Daniel Isac

2010-01-01

Investigaciones acerca del llanto infantil han permitido correlacionar características acústicas de éste con diversas patologías, demostrándose que el llanto infantil puede reflejar la integridad neurofisiológica del niño, el que como fenómeno biopsicosocial da una medida de la interacción del niño con el ambiente y de su desarrollo cognitivo y social. En esta tesis se presenta una Metodología de Análisis de Llanto Orientado al Diagnóstico de Patología en el Neurodesarrollo Infantil, aplicada...

Intrinsic Charge Transport in Organic Field-Effect Transistors

Science.gov (United States)

Podzorov, Vitaly

2005-03-01

Organic field-effect transistors (OFETs) are essential components of modern electronics. Despite the rapid progress of organic electronics, understanding of fundamental aspects of the charge transport in organic devices is still lacking. Recently, the OFETs based on highly ordered organic crystals have been fabricated with innovative techniques that preserve the high quality of single-crystal organic surfaces. This technological progress facilitated the study of transport mechanisms in organic semiconductors [1-4]. It has been demonstrated that the intrinsic polaronic transport, not dominated by disorder, with a remarkably high mobility of ``holes'' μ = 20 cm^2/Vs can be achieved in these devices at room temperature [4]. The signatures of the intrinsic polaronic transport are the anisotropy of the carrier mobility and an increase of μ with cooling. These and other aspects of the charge transport in organic single-crystal FETs will be discussed. Co-authors are Etienne Menard, University of Illinois at Urbana Champaign; Valery Kiryukhin, Rutgers University; John Rogers, University of Illinois at Urbana Champaign; Michael Gershenson, Rutgers University. [1] V. Podzorov et al., Appl. Phys. Lett. 82, 1739 (2003); ibid. 83, 3504 (2003). [2] V. C. Sundar et al., Science 303, 1644 (2004). [3] R. W. I. de Boer et al., Phys. Stat. Sol. (a) 201, 1302 (2004). [4] V. Podzorov et al., Phys. Rev. Lett. 93, 086602 (2004).

PETROBRAS Transportes (TRANSPETRO) contingency plan system; Metodologia SIE (Sistema Informatizado de Emergencia) aplicada no gerenciamento das contingencias

Energy Technology Data Exchange (ETDEWEB)

Berardinelli, Ricardo; Mendonca, Daniela [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil). Coordenacao de Seguranca, Saude e Meio Ambiente de Dutos e Terminais; Morais, Lucia B.; Carvalho, Marcelo Tilio M. de [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Informatica. Grupo de Tecnologia em Computacao Grafica (TECGRAF)

2005-07-01

This paper describes the PETROBRAS Transportes Emergency Response System, which was designed to improve the response to emergency situations. The plans are defined based on an evaluation of the organization of the emergency teams, the communication procedures, characterization of the installations, definition of accidental scenarios, environmental sensitivity maps; simulation of oil spill trajectories and dispersion behavior; geographical data of the area surrounding the installations; other conventional data related to the installations, including equipment available and the InfoPAE system. Plans include several scenarios as oil spills, gas, fire, explosion, hazardous materials which can be applied to terminals and pipelines. (author)

Scattering times in the two-dimensional electron gas of AlxGa1-xN/AlN/GaN heterostructures

International Nuclear Information System (INIS)

Han Xiuxun; Honda, Yoshio; Narita, Tetsuo; Yamaguchi, Masahito; Sawaki, Nobuhiko; Tanaka, Tooru; Guo Qixin; Nishio, Mitsushiro

2009-01-01

Low-field Hall and Shubnikov-de Haas (SdH) measurements were performed on two-dimensional electron gas of Al 0.24 Ga 0.76 N/GaN and Al 0.24 Ga 0.76 N/AlN/GaN heterostructures at a low temperature. A dramatic improvement in electron mobility is observed in Al 0.24 Ga 0.76 N/AlN/GaN heterostructures with 1 and 2 nm thick AlN interlayers. A further increase in the AlN thickness degrades the transport behaviour. Transport and quantum scattering times were derived from the corresponding Hall mobility and the oscillatory part of the SdH signal. The ratio of the transport scattering time and the quantum scattering time increases from 3.87 in the heterostructure without the AlN interlayer to 14.34 with the 1 nm AlN interlayer and to 12.45 with the 2 nm AlN interlayer. A modified scattering calculation due to charged dislocation with a finite length suggests that dislocation related long-range scattering event tends to dominate both transport and quantum scattering times when a thin AlN interlayer is introduced.

The effects of surface conditions on electronic transportation mechanism of Al/SnO2/p-Si/Al structure

International Nuclear Information System (INIS)

Karadeniz, S.

2001-01-01

In the present work it was aimed to determine the effect of surface states on the electronic conductivity of Al/SnO 2 /p-Si/Al structure. In order to realize that goal, the Al/SnO 2 /p-Si/Al diodes were prepared p-types, 0.8 Ω-cm resistivity from single crystalline silicon of orientation (111). A spraying system was established in order to produce SnO 2 thin films. The morphology of SnO 2 thin films were measured by means of Atomic Force Microscope (AFM). The physical parameters which effected on the electronical conductivity of the structures were determined. The forward current-voltage (I-V) measurements were performed in the temperature range of 173-313 K. The reverse capacitance-voltage (C-V) characteristics were measured at 100 Hz, 1 kHz,10 kHz, 100 kHz, 500 kHz and 1 MHz frequencies at the same temperature range. The energy profile of the surface states effecting on diodes were determined by using high-low frequency capacitance method, Chattopadhyay method and the relation between surface states and ideality factor

Spectrographic determination of impurities in ammonium bifluoride. III. Study of the processes of vaporization, transport and excitation of the elements Al, B, Cu and Cr; Determinacion espectrografico de impurezas en bifluoruro amonico. III. Estudio de los procesos de volatilizacion, transporte y excitacion de los elementos Al, B, Cu, Cr

Energy Technology Data Exchange (ETDEWEB)

Alduan, F A; Roca, M; Capdevila, C

1979-07-01

The influences of the processes of vaporization, transport and excitation on the shape of the volatilization-excitation curves and on the values of the spectral-line intensities have been investigated in a method for the spectrographic determination of Al, B, Cu and Cr In ammonium bifluoride samples by direct current are excitation in Scribner type electrodes, with addition of different matrices (graphite, 63203, GeO{sub 2}, MgO and Zn0). The reaction products in the electrode cavity have been identified by X-ray powder diffraction analysis and the percentages of vaporized and diffused element evaluated through analysis by total-burning spectrographic methods. In addition, the values of both the number of particles entering the discharge column and the transport efficiencies have been calculated. Thus, the origin of most observed differences has been explained. (Author) 11 refs.

Comparative investigation on cation-cation (Al-Sn) and cation-anion (Al-F) co-doping in RF sputtered ZnO thin films: Mechanistic insight

Energy Technology Data Exchange (ETDEWEB)

Mallick, Arindam; Basak, Durga, E-mail: sspdb@iacs.res.in

2017-07-15

Highlights: • Comparative study on Al, Al-Sn and Al-F doped ZnO films has been carried out. • High transparent Al-F co-doped film shows three times enhanced carrier density. • Al-F co-doped film shows larger carrier relaxation time. • Al-Sn co-doped films shows carrier transport dominated by impurity scattering. • Al-F co-doped ZnO film can be applied as transparent electrode. - Abstract: Herein, we report a comparative mechanistic study on cation-cation (Al-Sn) and cation-anion (Al-F) co-doped nanocrystalline ZnO thin films grown on glass substrate by RF sputtering technique. Through detailed analyses of crystal structure, surface morphology, microstructure, UV-VIS-NIR transmission-reflection and electrical transport property, the inherent characteristics of the co-doped films were revealed and compared. All the nanocrystalline films retain the hexagonal wurtzite structure of ZnO and show transparency above 90% in the visible and NIR region. As opposed to expectation, Al-Sn (ATZO) co-doped film show no enhanced carrier concentration consistent with the probable formation of SnO{sub 2} clusters supported by the X-ray photoelectron spectroscopy study. Most interestingly, it has been found that Al-F (AFZO) co-doped film shows three times enhanced carrier concentration as compared to Al doped and Al-Sn co-doped films attaining a value of ∼9 × 10{sup 20} cm{sup −3} due to the respective cation and anion substitution. The carrier relaxation time increases in AFZO while it decreases significantly for ATZO film consistent with the concurrence of the impurity scattering in the latter.

La investigación en pedagogía y didáctica aplicada a la educación física A pesquisa em pedagogia e didática aplicada à educação física Research on Teaching and Didactics Applied to Physical Education

OpenAIRE

Julia Adriana Castro-Carvajal; Leidy Johana Martínez-Escudero; Beatriz Elena Chaverra-Fernández

2012-01-01

Este texto forma parte de un proyecto de investigación que busca elaborar un estado del arte sobre investigación educativa en educación física, recreación y deporte en Antioquia entre 1998-2009. Este artículo analiza la producción de conocimiento sobre pedagogía y didáctica aplicada en los campos mencionados. Se trata de dar cuenta de aquello que atañe a las concepciones y los modelos pedagógicos y a los enfoques didácticos hallados en las investigaciones educativas revisadas. Los resultados ...

Unravelling regolith material types using Mg/Al and K/Al plot to support field regolith identification in the savannah regions of NW Ghana, West Africa

Science.gov (United States)

Arhin, Emmanuel; Zango, Saeed M.

2015-12-01

The XRF analytical method was used to measure the weight % of the major oxides in regolith samples. The metal weight % of Mg, K and Al were calculated from their oxides and were normalised relative to immobile Al calculated from its oxide. The plot of Mg/Al and K/Al identified the regolith of the study area to consist of 137 transported clays, 4 ferruginous sediments or ferricrete, 2 lateritic duricrust and 4 saprolites. Surface regolith that had undergone secondary transformation and shows compositional overlaps were 4 transported clays with Fe-oxide impregnation may be referred to as nodular laterite and 5 ferruginous saprolites. The variable regolith materials features identified from the 154 samples enabled the characterisation and identification of the different sample materials because an overprint of bedrock geochemistry is reflected in the regolith. Plot of Mg/Al and K/Al highlighted the compositional variability of the regolith samples and refute the notion of the homogeneity of all the sampled materials in the area. The study thus recognized Mg/Al versus K/Al plots to be used in supporting field identification of regolith mapping units particularly in complex regolith terrains of savannah regions of Ghana and in similar areas where geochemical exploration surveys are being carried out under cover.

Políticas de inclusão aplicadas na Universidade Federal de Santa Catarina: gestão social ou gestão estratégica?

Directory of Open Access Journals (Sweden)

Kátia Denise Moreira

2011-06-01

Full Text Available http://dx.doi.org/10.5007/1983-4535.2011v4nespp251   As políticas de inclusão, aplicadas no âmbito da Universidade Federal de Santa Catarina (UFSC estão expressas no programa de Ações Afirmativas, o qual trata do sistema de cotas, o Programa Incluir, aplicado para aqueles portadores de necessidades especiais, e o Curso Pré-Vestibular, que visa a democratizar o acesso ao ensino superior. O objetivo da pesquisa é investigar se essas políticas de inclusão são uma prática de gestão social ou se pretendem apenas atender ao definido na gestão estratégica da Instituição. A metodologia está embasada na abordagem científica de natureza predominantemente qualitativa. É descritiva, com base na análise de documentos, obras e relatórios.  O resultado evidencia que as políticas de inclusão da UFSC são aplicadas sob a ótica da gestão estratégica; entretanto, verificam-se elementos característicos da inovação social, e também há, em suas origens, alinhamento com o que pretende a gestão social.

Win-Win transport strategies: searching for synergies.

OpenAIRE

Valdés Serrano, Cristina; Monzón de Cáceres, Andrés; García Benítez, Francisco

2014-01-01

The need of an urban transport strategy on urban areas which solves the environmental problems derived from traffic without decreasing the trip attraction of these urban areas is taken for granted. Besides there is also a clear consensus among researchers and institutions in the need for integrated transport strategies (May et al., 2006; Zhang et al., 2006). But there is still a lack of knowledge on the policy measures to be implemented. This research aims to deepen in the understanding of h...

Comparison of electrical characteristic between AlN/GaN and AlGaN/GaN heterostructure Schottky diodes

International Nuclear Information System (INIS)

Lü Yuan-Jie; Feng Zhi-Hong; Gu Guo-Dong; Dun Shao-Bo; Yin Jia-Yun; Han Ting-Ting; Cai Shu-Jun; Lin Zhao-Jun

2014-01-01

Ni/Au Schottky contacts on AlN/GaN and AlGaN/GaN heterostructures are fabricated. Based on the measured current—voltage and capacitance—voltage curves, the electrical characteristics of AlN/GaN Schottky diode, such as Schottky barrier height, turn-on voltage, reverse breakdown voltage, ideal factor, and the current-transport mechanism, are analyzed and then compared with those of an AlGaN/GaN diode by self-consistently solving Schrödinger's and Poisson's equations. It is found that the dislocation-governed tunneling is dominant for both AlN/GaN and AlGaN/GaN Schottky diodes. However, more dislocation defects and a thinner barrier layer for AlN/GaN heterostructure results in a larger tunneling probability, and causes a larger leakage current and lower reverse breakdown voltage, even though the Schottky barrier height of AlN/GaN Schottky diode is calculated to be higher that of an AlGaN/GaN diode. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Investigación sobre el cotidiano del sujeto: oportunidades para una ciencia aplicada

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Manuel Amezcua

2012-01-01

Full Text Available Desde un modelo de investigación emergente, la Investigación Aplicada a los Cuidados, se propone reflexionar sobre una de las áreas de indagación: la Investigación sobre el Cotidiano del Sujeto. El cotidiano del sujeto se conceptualiza como un espacio de interacción social donde las personas ejercen autonomía para tomar decisiones y ejecutar acciones para cuidar su salud. A través de diseños principalmente cualitativos, la Investigación sobre el Cotidiano del Sujeto aporta evidencias útiles y pertinentes para la práctica enfermera porque hablan del contexto y desde la perspectiva de los sujetos. Estas evidencias pueden encuadrarse en cuatro grandes dimensiones: la comprensión del padecimiento humano ante la enfermedad, la cultura del cuidado, la percepción sobre las intervenciones en salud, y el cotidiano del cuidador. Finalmente se plantean algunos desafíos que nos propone la Investigación sobre el Cotidiano del Sujeto e implican tres dimensiones imprescindibles en el ejercicio del cuidado: la dimensión ética, política y científica.

Towards a relevant and sustainable R&D agenda for transport and transport infrastructure in South Africa

CSIR Research Space (South Africa)

Rust, FC

2009-01-01

Full Text Available and technological solutions summarised in main Research and Development (R&D) themes and sub-themes. DRIVERS, TRENDS AND ISSUES IN THE TRANSPORT INFRASTRUCTURE SECTOR The drivers that will influence the transport industry in the future were discussed in a... previous chapter. A recent technology foresight study for the construction industry in South Africa (Rust et al 2008) also listed a number of trends in the industry. Many of these trends are also important to the transport and transport infrastructure...

Estrategias mercadotécnicas aplicadas por la Federación Venezolana de Fútbol para posicionar la marca Vinotinto en el aficionado

OpenAIRE

Zavala González, Hely Danilo

2010-01-01

La siguiente investigación tuvo el propósito de conocer las estrategias mercadotécnicas aplicadas por la Federación Venezolana de Fútbol para lograr el posicionamiento de la marca Vinotinto en el público venezolano. Se utilizó la metodología de análisis documental y revisión teórica. Los resultados indican que la aceptación del aficionado por la selección nacional de mayores, es motivada tanto por el crecimiento de su calidad técnica como por unas estrategias mercadotécnicas bien dis...

Maize ZmALMT2 is a root anion transporter that mediates constitutive root malate efflux.

Science.gov (United States)

Ligaba, Ayalew; Maron, Lyza; Shaff, Jon; Kochian, Leon; Piñeros, Miguel

2012-07-01

Root efflux of organic acid anions underlies a major mechanism of plant aluminium (Al) tolerance on acid soils. This efflux is mediated by transporters of the Al-activated malate transporter (ALMT) or the multi-drug and toxin extrusion (MATE) families. ZmALMT2 was previously suggested to be involved in Al tolerance based on joint association-linkage mapping for maize Al tolerance. In the current study, we functionally characterized ZmALMT2 by heterologously expressing it in Xenopus laevis oocytes and transgenic Arabidopsis. In oocytes, ZmALMT2 mediated an Al-independent electrogenic transport product of organic and inorganic anion efflux. Ectopic overexpression of ZmALMT2 in an Al-hypersensitive Arabidopsis KO/KD line lacking the Al tolerance genes, AtALMT1 and AtMATE, resulted in Al-independent constitutive root malate efflux which partially restored the Al tolerance phenotype. The lack of correlation between ZmALMT2 expression and Al tolerance (e.g., expression not localized to the root tip, not up-regulated by Al, and higher in sensitive versus tolerance maize lines) also led us to question ZmALMT2's role in Al tolerance. The functional properties of the ZmALMT2 transporter presented here, along with the gene expression data, suggest that ZmALMT2 is not involved in maize Al tolerance but, rather, may play a role in mineral nutrient acquisition and transport. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

Performance assessment of gate material engineered AlInN/GaN underlap DG MOSFET for enhanced carrier transport efficiency

Science.gov (United States)

Pardeshi, Hemant M.; Raj, Godwin; Pati, Sudhansu; Mohankumar, N.; Sarkar, Chandan Kumar

2013-08-01

In the work proposed, performance of dual material gate (DMG) AlInN/GaN underlap DG MOSFET has been analyzed and compared with the corresponding performance of single material gate (SMG) AlInN/GaN underlap DG MOSFET using Sentaurus TCAD device simulation. A systematic, quantitative investigation of key device metrics for DMG-DG device is presented and a comparison with SMG-DG device is done for a wide range of gate and underlap lengths. The key idea in this paper is to demonstrate the improved performance exhibited by DMG-DG device over SMG-DG device, due to enhanced carrier transport efficiency and suppressed short channel effect (SCE). Simulation reveals an improvement in drain current, drain induced barrier lowering (DIBL), Ion/Ioff, Delay and Energy Delay Product (EDP) for DMG-DG MOSFET as compared to SMG-DG MOSFET. Very high drain current of 6.7 mA/μm, low DIBL of 1.62 mV/V, high Ion/Ioff ratio of 4.044e107, low delay of 0.001 ps and low EDP of 1.37e-31 J s/μm are obtained for DGM-DG device. However, subthreshold slope (SS) for DMG-DG device is on higher side than SMG-DG. The proposed AlInN/GaN Heterostructure Underlap DGM-DG MOSFET shows excellent promise as one of the candidates to substitute present MOSFET for future high speed applications.

Pampa Solar: un proyecto multidisciplinario para la construcción de un vehículo solar

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Silvano Rossi

2014-01-01

Full Text Available Los sistemas basados en energías limpias y de emisión cero como alternativas de movilidad sustentable aplicadas al transporte urbano son hoy una necesidad y justifican el objetivo de disponer de un vehículo solar como prototipo experimental. Así, la iniciativa de un grupo de trabajo constituido por docentes, estudiantes y personal no docente se focalizó en la construcción de un vehículo híbrido experimental motivado por una competencia latinoamericana de autos solares, en la que se validó su desempeño luego de su participación. El prototipo construido fue galardonado con el premio al uso más eficiente de energía solar. En el trabajo se presentan los aspectos constructivos del vehículo y resultados experimentales obtenidos durante la competición.

Síntesis evolutiva de mecanismos aplicada al diseño de un exoesqueleto para la rehabilitación de los dedos de la mano

OpenAIRE

Bataller, Alex; Cabrera, Juan Antonio; Castillo, Juan Jesús; Nadal, Fernando

2017-01-01

El movimiento pasivo es una técnica recomendada para la rehabilitación de ciertas lesiones de los dedos de la mano. Los ejercicios se realizan con ayuda de un fisioterapeuta en sesiones de pocos minutos varias veces al día. En los últimos años se han presentado diversos exoesqueletos para mover los dedos de la mano de forma controlada, que podrían ayudar al fisioterapeuta en esta tarea. Sin embargo, estos dispositivos no se han popularizado, principalmente debido a su complejidad y elevado pr...

Retos y oportunidades de la investigación en marketing interno

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Jessica Mendoza Moheno

2011-01-01

Full Text Available El objetivo de este ensayo es realizar un análisis de la conceptualización del marketing interno y las principales investigaciones aplicadas, con el fin de resaltar las oportunidades y retos que enfrenta, para lo cual, se hace una revisión de la literatura del tema en relación a su conceptualización, se analiza la orientación al cliente interno como elemento central del marketing interno, diferenciándola con la orientación al mercado. Así mismo, se destacan los principales hallazgos sobre las investigaciones aplicadas. Finalmente, se describen retos y oportunidades del marketing interno.

Riluzole protects against glutamate-induced slowing of neurofilament axonal transport.

LENUS (Irish Health Repository)

Stevenson, Alison

2009-04-24

Riluzole is the only drug approved for the treatment of amyotrophic lateral sclerosis (ALS) but its precise mode of action is not properly understood. Damage to axonal transport of neurofilaments is believed to be part of the pathogenic mechanism in ALS and this has been linked to defective glutamate handling and increased phosphorylation of neurofilament side-arm domains. Here, we show that riluzole protects against glutamate-induced slowing of neurofilament transport. Protection is associated with decreased neurofilament side-arm phosphorylation and inhibition of the activities of two neurofilament kinases, ERK and p38 that are activated in ALS. Thus, the anti-glutamatergic properties of riluzole include protection against glutamate-induced changes to neurofilament phosphorylation and transport.

Studies on charge transport in Al–doped La{sub 0.7}Ca{sub 0.3}Mn{sub 1−x}Al{sub x}O{sub 3} manganites

Energy Technology Data Exchange (ETDEWEB)

Rathod, Jalshikhaba S. [C.U. Shah Technical Institute of Diploma Studies, C.U. Shah University, Surendranagar 363030 (India); Keshvani, M.J. [B.H. Gardi College of Engineering and Technology, Rajkot 361162 (India); Department of Physics, Saurashtra University, Rajkot 360005 (India); Solanki, P.S.; Pandya, D.D.; Kataria, Bharat; Shah, N.A. [Department of Physics, Saurashtra University, Rajkot 360005 (India); Kuberkar, D.G., E-mail: dgkuberkar@gmail.com [Department of Physics, Saurashtra University, Rajkot 360005 (India)

2015-12-01

In this communication, we report the results of the studies on the effect of non-magnetic Al{sup 3+}-doping on structure and properties of La{sub 0.7}Ca{sub 0.3}Mn{sub 1−x}Al{sub x}O{sub 3} (LCMAO) manganites synthesized by conventional solid state reaction (SSR) route. The Rietveld refinement of the X-ray diffraction (XRD) data confirms the single phasic nature of the samples without any detectable impurities. All the samples exhibit metal to insulator transition (T{sub P}) which decrease with increase in Al{sup 3+} doping concentration while it increases with applied magnetic field. To understand the nature of charge transport in metallic and insulating regions of resistivity, various models and mechanisms have been used to fit the observed experimental data.

Thermophysical properties of αAl2O3, MgAl2O4 and AlN at low tempertures

International Nuclear Information System (INIS)

Burghartz, S.

1995-12-01

A possibility for producing energy in future might be the nuclear fusion. The process of nuclear fusion is characterized by melting nuclei of hydrogen atoms (deuterium and tritium) which yield to the production of helium atom nuclei. For this process extremely high temperatures of the deuterium-tritium-gas plasma are necessary. The additional heating of the plasma by microwaves requires materials with low diaelectric losses and high thermal conductivity. The thermal conductivity can be increased by cooling the windows which lead to the plasma chambre. Experimental investigations with the aim to check the influence of liquid nitrogen (T=70 K) on the cooling of the windows were performed in the temperature region 70 K 2 O 3 , MgAl 2 O 4 and AlN were measured. The thermal conductivity can be calculated using the equation λ=αc p ρ λ=thermal conductivity α=thermal diffusivity c p =specific heat (at constant pressure) ρ=density. Furthermore a theoretical method to calculate the thermal conductivity at low temperatures is presented; this is done by using a model modification of heat transport in electric insulators. As result the influence of intrinsic parameters (crystal structure, interatomar binding, anharmonicity) and extrinsic parameters (point defects, dislocations, boundary areas) upon thermal conductivity of α-Al 2 O 3 , MgAl 2 O 4 and AlN are achieved. (orig.)

Studies on the InAlN/InGaN/InAlN/InGaN double channel heterostructures with low sheet resistance

Science.gov (United States)

Zhang, Yachao; Wang, Zhizhe; Xu, Shengrui; Chen, Dazheng; Bao, Weimin; Zhang, Jinfeng; Zhang, Jincheng; Hao, Yue

2017-11-01

High quality InAlN/InGaN/InAlN/InGaN double channel heterostructures were proposed and grown by metal organic chemical vapor deposition. Benefiting from the adoption of the pulsed growth method and Two-Step AlN interlayer, the material quality and interface characteristics of the double channel heterostructures are satisfactory. The results of the temperature-dependent Hall effect measurement indicated that the transport properties of the double channel heterostructures were superior to those of the traditional single channel heterostructures in the whole test temperature range. Meanwhile, the sheet resistance of the double channel heterostructures reached 218.5 Ω/□ at 300 K, which is the record of InGaN-based heterostructures. The good transport properties of the InGaN double channel heterostructures are beneficial to improve the performance of the microwave power devices based on nitride semiconductors.

Global Transcriptome Analysis Reveals Distinct Aluminum-Tolerance Pathways in the Al-Accumulating Species Hydrangea macrophylla and Marker Identification.

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Haixia Chen

Full Text Available Hydrangea (Hydrangea macrophylla is a well known Al-accumulating plant, showing a high level of aluminum (Al tolerance and accumulation. Although the physiological mechanisms for detoxification of Al and the roles of Al in blue hydrangea sepals have been reported, the molecular mechanisms of Al tolerance and accumulation are poorly understood in hydrangea. In this study, we conducted a genome-wide transcriptome analysis of Al-response genes in the roots and leaves of hydrangea by RNA sequencing (RNA-seq. The assembly of hydrangea transcriptome provides a rich source for gene identification and mining molecular markers, including single nucleotide polymorphism (SNP and simple sequence repeat (SSR. A total of 401,215 transcripts with an average length of 810.77 bp were assembled, generating 256,127 unigenes. After annotation, 4,287 genes in the roots and 730 genes in the leaves were up-regulated by Al exposure, while 236 genes in the roots and 719 genes in the leaves were down-regulated, respectively. Many transporters, including MATE and ABC families, were involved in the process of Al-citrate complex transporting from the roots in hydrangea. A plasma membrane Al uptake transporter, Nramp aluminum transporter was up-regulated in roots and leaves under Al stress, indicating it may play an important role in Al tolerance by reducing the level of toxic Al. Although the exact roles of these candidate genes remain to be examined, these results provide a platform for further functional analysis of the process of detoxification of Al in hydrangea.

Relaxation-phenomena in LiAl/FeS-cells

Science.gov (United States)

Borger, W.; Kappus, W.; Panesar, H. S.

A theoretical model of the capacity of strongly relaxing electrochemical systems is applied to the LiAl/FeS system. Relaxation phenomena in LiAl and FeS electrodes can be described by this model. Experimental relaxation data indicate that lithium transport through the alpha-LiAl layer to the particle surface is the capacity limiting process at high discharge current density in the LiAl electrode in LiCl-KCl and LiF-LiCl-LiBr mixtures. Strong relaxation is observed in the FeS electrode with LiCl-KCl electrolyte caused by lithium concentration gradients and precipitation of KCl in the pores.

Als2 mRNA splicing variants detected in KO mice rescue severe motor dysfunction phenotype in Als2 knock-down zebrafish.

Science.gov (United States)

Gros-Louis, Francois; Kriz, Jasna; Kabashi, Edor; McDearmid, Jonathan; Millecamps, Stéphanie; Urushitani, Makoto; Lin, Li; Dion, Patrick; Zhu, Qinzhang; Drapeau, Pierre; Julien, Jean-Pierre; Rouleau, Guy A

2008-09-01

Recessive ALS2 mutations are linked to three related but slightly different neurodegenerative disorders: amyotrophic lateral sclerosis, hereditary spastic paraplegia and primary lateral sclerosis. To investigate the function of the ALS2 encoded protein, we generated Als2 knock-out (KO) mice and zAls2 knock-down zebrafish. The Als2(-/-) mice lacking exon 2 and part of exon 3 developed mild signs of neurodegeneration compatible with axonal transport deficiency. In contrast, zAls2 knock-down zebrafish had severe developmental abnormalities, swimming deficits and motor neuron perturbation. We identified, by RT-PCR, northern and western blotting novel Als2 transcripts in mouse central nervous system. These Als2 transcripts were present in Als2 null mice as well as in wild-type littermates and some rescued the zebrafish phenotype. Thus, we speculate that the newly identified Als2 mRNA species prevent the Als2 KO mice from developing severe neurodegenerative disease and might also regulate the severity of the motor neurons phenotype observed in ALS2 patients.

Factores asociados al desplazamiento activo en bicicleta al colegio en el Distrito Bogotá, Colombia. Estudio FUPRECOL

OpenAIRE

Beltrán Ahumada, César Augusto

2016-01-01

Introducción: El transporte activo (TA) puede ser una oportunidad para incrementar los niveles de actividad física diarios de los niños y adolescentes, además de destacarse como una estrategia práctica, accesible y sostenible a largo plazo. Objetivos: El objetivo del presente estudio es doble: Analizar los patrones de desplazamiento activo en bicicleta al y desde el centro educativo, y b) Identificar los factores asociados al uso de la bicicleta como TA; en una muestra de niños...

Ambientes virtuales de aprendizaje utilizando realidad aumentada

Directory of Open Access Journals (Sweden)

Diana Nancy Martínez García

2018-03-01

Full Text Available Realidad aumentada o Augmented reality es una nueva tecnología que al combinarla con espacios físicos permite ampliar el espectro de la información relacionada con dichos espacios; esto se hace a través de la superposición de imágenes, información o material audiovisual específico aplicado a cualquier área de conocimiento. Los ambientes virtuales de aprendizaje basados en realidad aumentada prometen innovación debido a que transforman los escenarios de aprendizaje real mediante el uso de nuevas tecnologías aplicadas al ámbito educativo, complementando de esta manera la percepción e interacción con el mundo real; logrando el acceso a nuevos contenidos prescindiendo de recursos físicos. En cuanto al uso de la realidad aumentada aplicada al área de enfermería, existe un sinnúmero de herramientas para complementar una clase magistral y enriquecer el proceso de aprendizaje. Sin embargo, la mayoría de los desarrollos realizados utilizando realidad aumentada proviene de contextos diferentes al nuestro, por lo que resulta importante fomentar el uso de este tipo de herramientas para que suscite el interés de los desarrolladores locales de tecnologías aplicadas al ámbito educativo y más específicamente el de salud. El objetivo de la presente revisión fue fundamentar teóricamente acerca de los ambientes virtuales de aprendizaje utilizando aplicaciones basadas en realidad aumentada.

CATALIZADOR ESTRUCTURADO DE Pt/Al2O3 SOBRE UNA ESPUMA DE ACERO INOXIDABLE (AISI 314 PARA LA OXIDACIÓN DE CO

Directory of Open Access Journals (Sweden)

Juan P. Bortolozzi

2011-01-01

Full Text Available Se obtuvo un catalizador estructurado por recubrimiento de Pt/Al2O3 sobre las paredes de una espuma de acero inoxidable AISI 314. Para estabilizar térmicamente e incrementar la rugosidad de la superficie de la espuma original se realizó un tratamiento a 900°C por 2 h. El soporte, Al2O3, y el metal activo, Pt, se incorporaron por inmersión. Las técnicas de caracterización aplicadas, XRD, LRS y SEM-EDX, permiten concluir que el tratamiento térmico previo indujo la formación de óxido de cromo y de las espinelas Mn1+xCr2-xO4-x y FeCr2O4 como fases principales en las paredes del sustrato. El espesor de la capa formada es cercano a 1 μm y los cristales producidos tienen forma octaédrica. El cubrimiento de alúmina presentó en general una apariencia homogénea, sin interacción con los óxidos formados durante el tratamiento. El Pt se distribuyó de manera uniforme, resultando un catalizador muy activo para la reacción test elegida: oxidación de monóxido de carbono.

on Ti6AL4V for biomedical applications

Directory of Open Access Journals (Sweden)

Juan José Pavón

2006-01-01

Full Text Available La fijación al tejido receptor de implantes para el reemplazo de hueso puede ser mejorada si poseen una superficie bioactiva con la capacidad de precipitar hidroxiapatita in vivo. Las aleaciones de titanio, a pesar de sus buenas propiedades mecánicas y comportamiento no-tóxico, no son bioactivas y, por tanto, no se enlazan directamente al hueso. Una de las maneras de modificar una superficie metálica bioinerte es recubriéndola con material bioactivo. En este trabajo se presenta la evaluación del comportamiento a fatiga mediante indentación hertziana (esférica de un recubrimiento de vidrio sobre Ti6Al4V. Este recubrimiento pertenece al sistema SiO2-CaO-MgO-Na2O-K2O-P2O5 y, a pesar de que puede usarse para protección contra la corrosión, ha sido específicamente diseñado para ser utilizado como capa interna de un recubrimiento bicapa bioactivo con una capa externa de bajo contenido en SiO2 para garantizar la bioactividad. Los ensayos hertzianos monotónicos permitieron obtener una secuencia de daños comenzando con tres eventos de daño tipo frágil (agrietamiento tipo anillo, cono y radial seguidos por la delaminación del recubrimiento asociada a la deformación plástica del substrato. El primer daño frágil, el agrietamiento tipo anillo, fue usado como criterio para la evaluación del agrietamiento por corrosión bajo tensión y por carga cíclica, en aire y agua destilada. Los resultados mostraron la sensibilidad del recubrimiento a la degradación bajo ambos tipos de carga, estática y cíclica, siendo esta degradación considerablemente mayor en agua destilada debido a la susceptibilidad del vidrio a la corrosión. La delaminación fue también sensible a la carga cíclica hertziana presentando dos mecanismos diferentes dependiendo de la máxima carga aplicada.

Desenvolvimento de uma estrutura de controle de posição aplicada ao Manipulador Robótico RD5NT

Directory of Open Access Journals (Sweden)

Sergio Assis Galito Araujo

2015-02-01

Full Text Available Neste trabalho é desenvolvida uma estrutura de controle de posição do tipo RASTRO e aplicada no estudo de caso com uso do manipulador robótico modelo RD5NT do fabricante Didacta Itália. São detalhados a formulação matemática da estrutura de controle assim como os procedimentos adotados para gerar a trajetória desejada e para identificar em tempo real o modelo matemático do manipulador robótico. A seguir, a estrutura de controle apresentada é implementada numericamente e, através de simulações numéricas, é avaliada a qualidade do controlador proposto.

Cadenas de Markov aplicadas al diagnóstico y tratamiento de conductas y procesos de aprendizaje

Directory of Open Access Journals (Sweden)

Óscar SAENZ BARRIO

2009-11-01

Full Text Available Los paradigmas de investigación educativa se centran fundamentalmente en la determinación de la relación causal entre variables, bien sean éstas uni o multidimensionales, bien concurrentes en el tiempo o distales. En cualquier caso se acepta que las variables causales acontecen antes del evento que producen. Desde un punto de vista teórico, la «covariacion» entre las variables antecedentes y consecuentes sería la evidencia explicativa de la ciencia, y en todo caso permitiría la predictibilidad de un acontecimiento a partir de otro. Sólo si sabemos que hay una relación entre El y E2 podremos hacer previsiones acerca de E2 cuando surja la situación El (Eigenmann, 1981, 29. Desde el punto de vista educativo, la relación entre dos estados (antecedente-consecuente, involucrados en un cambio es muy importante, pero no dice nada en cuanto al proceso de intervención. Puede normar la acción («para conseguir ésto hay que hacer lo otro», pero no prescribe cuándo hay que hacerlo. Dado que la educación es un proceso ordenado en el tiempo, el momento de ejercer las diferentes providencias educativas que configuran conductas, sentimientos, ideales, conocimientos, valores, etc. es uno de los componentes esenciales de su eficacia; lo que hoy podría llamarse optimización de la intervención. Y si ello es cierto para la creación de un aprendizaje cualquiera, lo es más cuando se trata de procesos específicos para reforzar pautas deseables o evitar/eliminar comportamientos indeseables o incorrectos.

Novas tecnologias aplicadas às embalagens de alimentos

Directory of Open Access Journals (Sweden)

Flávia De Floriani Pozza Rebello

2009-12-01

Full Text Available Com o desenvolvimento da indústria de alimentos, as embalagens têm se aperfeiçoado, indo além de sua função básica de proteger o alimento contra danos mecânicos e contaminações químicas e microbiológicas. Elas têm cada vez mais desempenhando papel de destaque, contribuindo ativamente para a venda de um produto. Assim, as indústrias de embalagens têm procurado atender aos consumidores mais exigentes e juntamente aos centros de pesquisa e universidades, têm investido mais em estudos de novas tecnologias, a fim de prolongar as características de qualidade do alimento, conferir melhor aparência, maior proteção mecânica no embarque, transporte, desembarque e nos supermercados, oferecer embalagens mais compactas, que ocupem menos espaço na geladeira, com abertura e fechamento mais fáceis, e que utilizem materiais de fácil reciclagem ou decomposição no ambiente. Com o objetivo de atender às novas expectativas das indústrias de alimentos e dos consumidores, surgem as embalagens ativas e as embalagens inteligentes. As embalagens ativas são aquelas que interagem de alguma forma com o alimento, seja liberando substâncias conservantes ao longo da vida de prateleira do produto, ou “corrigindo” alguns problemas naturais do alimento, como sabor amargo por exemplo, em que algumas enzimas podem ser adicionadas ao material de embalagem, minimizando este problema e tornando o produto mais saboroso. Já as embalagens inteligentes indicam as modificações químicas às quais os alimentos estão passando, como mudanças de pH, por exemplo, indicando alterações na qualidade do produto.

Porous media geometry and transports

CERN Document Server

Adler, Pierre

1992-01-01

The goal of ""Porous Media: Geometry and Transports"" is to provide the basis of a rational and modern approach to porous media. This book emphasizes several geometrical structures (spatially periodic, fractal, and random to reconstructed) and the three major single-phase transports (diffusion, convection, and Taylor dispersion).""Porous Media"" serves various purposes. For students it introduces basic information on structure and transports. Engineers will find this book useful as a readily accessible assemblage of al the major experimental results pertaining to single-phase tr

Fluid transport in reaction induced fractures

Science.gov (United States)

Ulven, Ole Ivar; Sun, WaiChing; Malthe-Sørenssen, Anders

2015-04-01

The process of fracture formation due to a volume increasing chemical reaction has been studied in a variety of different settings, e.g. weathering of dolerites by Røyne et al. te{royne}, serpentinization and carbonation of peridotite by Rudge et al. te{rudge} and replacement reactions in silica-poor igneous rocks by Jamtveit et al. te{jamtveit}. It is generally assumed that fracture formation will increase the net permeability of the rock, and thus increase the reactant transport rate and subsequently the total rate of material conversion, as summarised by Kelemen et al. te{kelemen}. Ulven et al. te{ulven_1} have shown that for fluid-mediated processes the ratio between chemical reaction rate and fluid transport rate in bulk rock controls the fracture pattern formed, and Ulven et al. te{ulven_2} have shown that instantaneous fluid transport in fractures lead to a significant increase in the total rate of the volume expanding process. However, instantaneous fluid transport in fractures is clearly an overestimate, and achievable fluid transport rates in fractures have apparently not been studied in any detail. Fractures cutting through an entire domain might experience relatively fast advective reactant transport, whereas dead-end fractures will be limited to diffusion of reactants in the fluid, internal fluid mixing in the fracture or capillary flow into newly formed fractures. Understanding the feedback process between fracture formation and permeability changes is essential in assessing industrial scale CO2 sequestration in ultramafic rock, but little is seemingly known about how large the permeability change will be in reaction-induced fracturing. In this work, we study the feedback between fracture formation during volume expansion and fluid transport in different fracture settings. We combine a discrete element model (DEM) describing a volume expanding process and the related fracture formation with different models that describe the fluid transport in the

Littoral Hydrodynamics and Sediment Transport Around a Semi-Permeable Breakwater

Science.gov (United States)

2015-09-18

Australasian Coasts & Ports Conference 2015 15 - 18 September 2015, Auckland , New Zealand Li, H et al. Littoral Hydrodynamics and Sediment...Coasts and Ports 2015, Auckland , New Zealand, 15-18 September, 2015, 7 pp. Littoral Hydrodynamics and Sediment Transport Around a Semi...Conference 2015 15 - 18 September 2015, Auckland , New Zealand Li, H et al. Littoral Hydrodynamics and Sediment Transport 2 The bathymetric and side

Técnicas aplicadas al reconocimiento de implicación textual.

OpenAIRE

Herrera, Jesús; Peñas, Anselmo; Verdejo, Felisa

2005-01-01

Tras establecer qué se entiende por implicación textual, se expone la situación actual y el futuro deseable de los sistemas dirigidos a reconocerla. Se realiza una identificación de las técnicas que implementan actualmente los principales sistemas de Reconocimiento de Implicación Textual.

Superconducting properties of Zn and Al double-doped Mg1-x(Zn0.5Al0.5)xB2

DEFF Research Database (Denmark)

Xu, G.J.; Grivel, Jean-Claude; Abrahamsen, A.B.

2004-01-01

(XRD), ac susceptibility, magnetization and resistivity. The double doping leads to decreases in both the lattice parameters a and c, and the T-c decreases with increasing dopant content. A systematical comparison with Al doped- and Li, Al double doped MgB2 of structure, superconducting transition......A series of polycrystalline samples of Mg1-x(Zn0.5Al0.5)(x)B-2 (0less than or equal toxless than or equal to0.8) were prepared by solid state reaction method and their structure, superconducting transition temperature (T-c) and transport properties were investigated by means of X-ray diffraction...

Pesquisando a partir da perspectiva da complexidade na área de linguística Aplicada

Directory of Open Access Journals (Sweden)

Maria Eugenia Witzler D'ESPOSITO

2015-06-01

Full Text Available O mundo em constante evolução solicita mudanças na forma como investigamos as salas de aula, nossa prática docente e desenvolvemos pesquisas. O objetivo deste artigo é ponderar nessa direção e apontar uma visão de pesquisa e de metodologia distanciada do cunho positivista do paradigma tradicional e que permite que tenhamos um olhar diferenciado para as vivências sendo investigadas. Para tal, compartilhamos a experiência de Costa Neves (2011 e D'Esposito (2012 que, ao desenvolverem suas pesquisas de doutoramento na área de Linguística Aplicada, buscaram uma metodologia de pesquisa coaduna à perspectiva da complexidade que foi a base de desenvolvimento de suas pesquisas. Assim sendo, neste trabalho os pesquisadores apresentam o diálogo por eles estabelecido entre a complexidade (Morin, 1990/2008, 1999/2006a,b, 2005/2006; Moraes, 1997/2006; Mariotti, 2007, et alli e a abordagem hermenêutico-fenomenológica (van Manen, 1990; Freire, 1998, 2007, 2008a,b, 2010.

On the optimization of asymmetric barrier layers in InAlGaAs/AlGaAs laser heterostructures on GaAs substrates

International Nuclear Information System (INIS)

Zhukov, A. E.; Asryan, L. V.; Semenova, E. S.; Zubov, F. I.; Kryzhanovskaya, N. V.; Maximov, M. V.

2015-01-01

Band offsets at the heterointerface are calculated for various combinations of InAlGaAs/AlGaAs heteropairs that can be synthesized on GaAs substrates in the layer-by-layer pseudomorphic growth mode. Patterns which make it possible to obtain an asymmetric barrier layer providing the almost obstruction-free transport of holes and the highest possible barrier height for electrons are found. The optimal compositions of both compounds (In 0.232 Al 0.594 Ga 0.174 As/Al 0.355 Ga 0.645 As) at which the flux of electrons across the barrier is at a minimum are determined with consideration for the critical thickness of the indium-containing quaternary solid solution

Modeling spin magnetization transport in a spatially varying magnetic field

Science.gov (United States)

Picone, Rico A. R.; Garbini, Joseph L.; Sidles, John A.

2015-01-01

We present a framework for modeling the transport of any number of globally conserved quantities in any spatial configuration and apply it to obtain a model of magnetization transport for spin-systems that is valid in new regimes (including high-polarization). The framework allows an entropy function to define a model that explicitly respects the laws of thermodynamics. Three facets of the model are explored. First, it is expressed as nonlinear partial differential equations that are valid for the new regime of high dipole-energy and polarization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield (1975) [1]. Differences among the three forms of the model are illustrated by numerical solution with parameters corresponding to a magnetic resonance force microscopy (MRFM) experiment (Degen et al., 2009 [2]; Kuehn et al., 2008 [3]; Sidles et al., 2003 [4]; Dougherty et al., 2000 [5]). A family of analytic, steady-state solutions to the nonlinear equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. Finally, we analyze the separative quality of magnetization transport, and a steady-state solution for the magnetization is shown to be compatible with Fenske's separative mass transport equation (Fenske, 1932 [6]).

Suppression of turbulent transport in NSTX internal transport barriers

Science.gov (United States)

Yuh, Howard

2008-11-01

Electron transport will be important for ITER where fusion alphas and high-energy beam ions will primarily heat electrons. In the NSTX, internal transport barriers (ITBs) are observed in reversed (negative) shear discharges where diffusivities for electron and ion thermal channels and momentum are reduced. While neutral beam heating can produce ITBs in both electron and ion channels, High Harmonic Fast Wave (HHFW) heating can produce electron thermal ITBs under reversed magnetic shear conditions without momentum input. Interestingly, the location of the electron ITB does not necessarily match that of the ion ITB: the electron ITB correlates well with the minimum in the magnetic shear determined by Motional Stark Effect (MSE) [1] constrained equilibria, whereas the ion ITB better correlates with the maximum ExB shearing rate. Measured electron temperature gradients can exceed critical linear thresholds for ETG instability calculated by linear gyrokinetic codes in the ITB confinement region. The high-k microwave scattering diagnostic [2] shows reduced local density fluctuations at wavenumbers characteristic of electron turbulence for discharges with strongly negative magnetic shear versus weakly negative or positive magnetic shear. Fluctuation reductions are found to be spatially and temporally correlated with the local magnetic shear. These results are consistent with non-linear gyrokinetic simulations predictions showing the reduction of electron transport in negative magnetic shear conditions despite being linearly unstable [3]. Electron transport improvement via negative magnetic shear rather than ExB shear highlights the importance of current profile control in ITER and future devices. [1] F.M. Levinton, H. Yuh et al., PoP 14, 056119 [2] D.R. Smith, E. Mazzucato et al., RSI 75, 3840 [3] Jenko, F. and Dorland, W., PRL 89 225001

Ensino e práticas da fisioterapia aplicada à criança na formação do fisioterapeuta

Directory of Open Access Journals (Sweden)

Maria José de Paula Guedes

Full Text Available INTRODUÇÃO: É um dos desafios delegados aos docentes da Fisioterapia formar profissionais conhecedores do que é particular na abordagem à criança, no intuito de favorecer estratégias ambientais e sociais favoráveis ao desenvolvimento potencial da criança. OBJETIVO: Investigar o ensino e a aprendizagem da Fisioterapia aplicada à criança, nos cursos de Fisioterapia de Alagoas. MÉTODOS E MATERIAIS: Estudo exploratório, descritivo, construído a partir de uma abordagem qualitativa e quantitativa, realizado com docentes responsáveis pelo ensino e egressos dos cursos de Fisioterapia do estado. O procedimento adotado é a análise documental do plano de ensino do curso; aplicação de questionário utilizando escala de Lirket aos alunos e entrevistas com os professores, obedecendo a núcleos direcionadores para análise temática. RESULTADOS: Foi percebido que o ensino de Fisioterapia aplicada à criança em Alagoas sofre as consequências do crescimento explosivo do número de cursos, ocorrido nesta última década; demonstra práticas tradicionais da Fisioterapia, voltada para as doenças, entre estas as neurológicas e afecções respiratórias. Os professores com formação docente indicaram iniciativas em metodologias ativas e visão mais intregral da saúde das crianças. CONCLUSÃO: Docentes e egressos sugerem alterações no projeto pedagógico, com ampliação e antecipação das vivências práticas, inserção de novos conteúdos disciplinares e ampliação da carga horária; mudanças na metodologia de ensino com ampliação da problematização no ensino e mais apoio institucional a essas mudanças; implementação de ações inter e multidisciplinares; melhorias na articulação teórico-prática.

Observation of the transition from diffusive regime to ballistic regime of the 2DEG transport property in Al xGa1-xN/GaN heterostructures

International Nuclear Information System (INIS)

Han, K.; Shen, B.; Tang, N.; Tang, Y.Q.; He, X.W.; Qin, Z.X.; Yang, Z.J.; Zhang, G.Y.; Lin, T.; Zhu, B.; Zhou, W.Z.; Chu, J.H.

2007-01-01

Electron-electron interaction effect of the two-dimensional electron gas (2DEG) in Al x Ga 1-x N/GaN heterostructures has been investigated by means of magnetotransport measurements at low temperatures. From the temperature dependence of the longitudinal conductivity of the heterostructures, a clear transition region has been observed. Based on the theoretical analysis, we conclude that this region corresponds to the transition from the diffusive regime to the ballistic regime of the 2DEG transport property. The interaction constant is determined to be -0.423, which is consistent with the theoretical prediction. However, the critical temperature for the transition, which is 8 K in Al x Ga 1-x N/GaN heterostructures, is much higher than the theoretical prediction

Modeling spin magnetization transport in a spatially varying magnetic field

Energy Technology Data Exchange (ETDEWEB)

Picone, Rico A.R., E-mail: rpicone@stmartin.edu [Department of Mechanical Engineering, University of Washington, Seattle (United States); Garbini, Joseph L. [Department of Mechanical Engineering, University of Washington, Seattle (United States); Sidles, John A. [Department of Orthopædics, University of Washington, Seattle (United States)

2015-01-15

We present a framework for modeling the transport of any number of globally conserved quantities in any spatial configuration and apply it to obtain a model of magnetization transport for spin-systems that is valid in new regimes (including high-polarization). The framework allows an entropy function to define a model that explicitly respects the laws of thermodynamics. Three facets of the model are explored. First, it is expressed as nonlinear partial differential equations that are valid for the new regime of high dipole-energy and polarization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield (1975) [1]. Differences among the three forms of the model are illustrated by numerical solution with parameters corresponding to a magnetic resonance force microscopy (MRFM) experiment (Degen et al., 2009 [2]; Kuehn et al., 2008 [3]; Sidles et al., 2003 [4]; Dougherty et al., 2000 [5]). A family of analytic, steady-state solutions to the nonlinear equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. Finally, we analyze the separative quality of magnetization transport, and a steady-state solution for the magnetization is shown to be compatible with Fenske's separative mass transport equation (Fenske, 1932 [6]). - Highlights: • A framework for modeling the transport of conserved magnetic and thermodynamic quantities in any spatial configuration. • A thermodynamically grounded model of spin magnetization transport valid in new regimes, including high-polarization. • Analysis of the separative quality of

Modeling spin magnetization transport in a spatially varying magnetic field

International Nuclear Information System (INIS)

Picone, Rico A.R.; Garbini, Joseph L.; Sidles, John A.

2015-01-01

We present a framework for modeling the transport of any number of globally conserved quantities in any spatial configuration and apply it to obtain a model of magnetization transport for spin-systems that is valid in new regimes (including high-polarization). The framework allows an entropy function to define a model that explicitly respects the laws of thermodynamics. Three facets of the model are explored. First, it is expressed as nonlinear partial differential equations that are valid for the new regime of high dipole-energy and polarization. Second, the nonlinear model is explored in the limit of low dipole-energy (semi-linear), from which is derived a physical parameter characterizing separative magnetization transport (SMT). It is shown that the necessary and sufficient condition for SMT to occur is that the parameter is spatially inhomogeneous. Third, the high spin-temperature (linear) limit is shown to be equivalent to the model of nuclear spin transport of Genack and Redfield (1975) [1]. Differences among the three forms of the model are illustrated by numerical solution with parameters corresponding to a magnetic resonance force microscopy (MRFM) experiment (Degen et al., 2009 [2]; Kuehn et al., 2008 [3]; Sidles et al., 2003 [4]; Dougherty et al., 2000 [5]). A family of analytic, steady-state solutions to the nonlinear equation is derived and shown to be the spin-temperature analog of the Langevin paramagnetic equation and Curie's law. Finally, we analyze the separative quality of magnetization transport, and a steady-state solution for the magnetization is shown to be compatible with Fenske's separative mass transport equation (Fenske, 1932 [6]). - Highlights: • A framework for modeling the transport of conserved magnetic and thermodynamic quantities in any spatial configuration. • A thermodynamically grounded model of spin magnetization transport valid in new regimes, including high-polarization. • Analysis of the separative quality of

Optical and electrical properties of polycrystalline and amorphous Al-Ti thin films

DEFF Research Database (Denmark)

Canulescu, Stela; Borca, C. N.; Rechendorff, Kristian

2016-01-01

The structural, optical, and transport properties of sputter-deposited Al-Ti thin films have been investigated as a function of Ti alloying with a concentration ranging from 2% to 46%. The optical reflectivity of Al-Ti films at visible and near-infrared wavelengths decreases with increasing Ti...... content. Xray absorption fine structure measurements reveal that the atomic ordering around Ti atoms increases with increasing Ti content up to 20% and then decreases as a result of a transition from a polycrystalline to amorphous structure. The transport properties of the Al-Ti films are influenced...... by electron scattering at the grain boundaries in the case of polycrystalline films and static defects, such as antisite effects and vacancies in the case of the amorphous alloys. The combination of Ti having a real refractive index (n) comparable with the extinction coefficient (k) and Al with n much smaller...

Electron transport in all-Heusler Co2CrSi/Cu2CrAl/Co2CrSi device, based on ab-initio NEGF calculations

Science.gov (United States)

Mikaeilzadeh, L.; Pirgholi, M.; Tavana, A.

2018-05-01

Based on the ab-initio non-equilibrium Green's function (NEGF) formalism based on the density functional theory (DFT), we have studied the electron transport in the all-Heusler device Co2CrSi/Cu2CrAl/Co2CrSi. Results show that the calculated transmission spectra is very sensitive to the structural parameters and the interface. Also, we obtain a range for the thickness of the spacer layer for which the MR effect is optimum. Calculations also show a perfect GMR effect in this device.

Análisis al desarrollo social territorial: estimular competencias y fortalecer estrategias

Directory of Open Access Journals (Sweden)

Cristian Eugenio Orellana Pino

Full Text Available Al observar la dinámica regional este trabajo pretende evaluar la acción de los agentes sociales en el modo de aplicar los instrumentos y métodos con objetivos a retos estratégicos. Este trabajo pretende evaluar como implementar proyectos bajo la visión del control de gestión como proceso clave para alcanzar los objetivos de un plano de integración comercial; comprender la necesidad de evaluar herramientas políticas, sociales y económicas, ya que en su ausencia, pueden causar problemas en metodologías cuando aplicadas en espacios periféricos; entender el análisis de la integración de los territorios con miras a la creación de polos regionales estratégicos estableciendo escenarios que se promueven por la creación de un planificado proceso de gestión social. Ciertos países Latinoamericanos, han podido demostrar con casos concretos, que si bien planificados, pueden proyectarse a territorios periféricos en el uso de una estrategia que fortalezca el crecimiento y su desarrollo.

Electrical transport characterization of Al and Sn doped Mg 2 Si thin films

KAUST Repository

Zhang, Bo

2017-05-22

Thin-film Mg2Si was deposited using radio frequency (RF) magnetron sputtering. Al and Sn were incorporated as n-type dopants using co-sputtering to tune the thin-film electrical properties. X-ray diffraction (XRD) analysis confirmed that the deposited films are polycrystalline Mg2Si. The Sn and Al doping concentrations were measured using Rutherford backscattering spectroscopy (RBS) and energy dispersive X-ray spectroscopy (EDS). The charge carrier concentration and the charge carrier type of the Mg2Si films were measured using a Hall bar structure. Hall measurements show that as the doping concentration increases, the carrier concentration of the Al-doped films increases, whereas the carrier concentration of the Sn-doped films decreases. Combined with the resistivity measurements, the mobility of the Al-doped Mg2Si films is found to decrease with increasing doping concentration, whereas the mobility of the Sn-doped Mg2Si films is found to increase.

Dehydration of δ-AlOOH in the lower mantle

Science.gov (United States)

Piet, H.; Shim, S. H.; Tappan, J.; Leinenweber, K. D.; Greenberg, E.; Prakapenka, V. B.

2017-12-01

Hydrous phase δ-AlOOH is an important candidate for water transport and storage in the Earth's deep mantle [1]. Knowing the conditions, under which it is stable and dehydrated, is therefore important for understanding the water transportation to the deep mantle or even to the core. A few experimental studies [1, 2] have shown that δ-AlOOH may be stable in cold descending slabs while it is dehydrated into a mixture of corundum and water under normal mantle conditions, up to 25 GPa. A subsequent study [3] reported the stability of δ-AlOOH in cold descending slabs to the core-mantle boundary conditions (2300 K at 135 GPa). However, the dehydration of δ-AlOOH has not bee directly observed in the experiments conducted at pressures above 25 GPa. We have synthesized δ-AlOOH from diaspore and Al(OH)3 in multi-anvil press at ASU. The sample was mixed with Au for coupling with near IR laser beams and loaded in diamond-anvil cells. We performed the laser-heated diamond anvil cell experiments at the 13IDD beamline of the Advanced Photon Source and ASU. At APS, we measured X-ray diffraction patterns at in situ high pressure and temperature. We observed the appearance of the corundum diffraction lines at 1700-2000 K and 55-90 GPa, indicating the dehydration of δ-AlOOH to Al2O3+ H2O. We found that the transition occurs over a broad range of temperature (500 K). We also observed that the dehydration of δ-AlOOH was accompanied by sudden change in laser coupling, most likely due to the release of fluids. The property change also helps us to determine the dehydration at ASU without in situ XRD. Our new experimental results indicate that δ-AlOOH would be stable in most subducting slabs in the deep mantle. However, because the dehydration occurs very close to the temperatures expected for the lower mantle, its stability is uncertain in the normal mantle. [1] Ohtani et al. 2001, Stability field of new hydrous phase, delta-AlOOH, Geophysical Research Letters 28, 3991-3993. [2

The Advanced Light Source (ALS) Radiation Safety System

International Nuclear Information System (INIS)

Ritchie, A.L.; Oldfather, D.E.; Lindner, A.F.

1993-08-01

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 Gev synchrotron light source facility consisting of a 120 kev electron gun, 50 Mev linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. Figure 1. ALS floor plan. Pairs of neutron and gamma radiation monitors are shown as dots numbered from 1 to 12. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies

Enhanced thermoelectric transport in modulation-doped GaN/AlGaN core/shell nanowires.

Science.gov (United States)

Song, Erdong; Li, Qiming; Swartzentruber, Brian; Pan, Wei; Wang, George T; Martinez, Julio A

2016-01-08

The thermoelectric properties of unintentionally n-doped core GaN/AlGaN core/shell N-face nanowires are reported. We found that the temperature dependence of the electrical conductivity is consistent with thermally activated carriers with two distinctive donor energies. The Seebeck coefficient of GaN/AlGaN nanowires is more than twice as large as that for the GaN nanowires alone. However, an outer layer of GaN deposited onto the GaN/AlGaN core/shell nanowires decreases the Seebeck coefficient at room temperature, while the temperature dependence of the electrical conductivity remains the same. We attribute these observations to the formation of an electron gas channel within the heavily-doped GaN core of the GaN/AlGaN nanowires. The room-temperature thermoelectric power factor for the GaN/AlGaN nanowires can be four times higher than the GaN nanowires. Selective doping in bandgap engineered core/shell nanowires is proposed for enhancing the thermoelectric power.

Mejora en la producción de recubrimientos de NiAl obtenidos por síntesis autopropagada a alta temperatura mediante energía solar concentrada

Directory of Open Access Journals (Sweden)

Sierra, C.

2005-12-01

Full Text Available The production of NiAl coatings on steel can be achieved in a quick, cheap and unpolluted way. All this advantages are possible using concentrated solar energy (CSE and selfpropagating high-temperature synthesis (SHS. SHS process allows the production of NiAl in short periods of using of the heat released in the reaction. Initial energy is provided by concentrated solar energy. The aim of this work is to improve the adherence between steel and coating. Two kinds of samples are examined: samples with Ni powder layer, and samples electroplated with nickel.

Se presenta un procedimiento para la obtención de recubrimientos de NiAl sobre acero, de forma rápida, barata y limpia desde el punto de vista medioambiental. Todas estas ventajas son posibles mediante el empleo combinado de la Energía Solar Concentrada (CSE y la Síntesis Autopropagada a Alta Temperatura (SHS aplicada a la producción de intermetálicos. Las reacciones SHS permiten la obtención de NiAl en procesos de corta duración, prácticamente instantáneos, aprovechando la elevada exotermicidad de la propia reacción. El aporte energético inicial se realiza concentrando radiación solar con una lente de Fresnel. El objetivo del trabajo presentado era mejorar la adherencia del recubrimiento de NiAl al acero base; se comparan los resultados de los ensayos entre probetas con una capa intermedia de polvo de níquel y probetas con níquel electrodepositado.

Spectrographic determination of impurities in ammonium bifluoride. III. Study of the processes of vaporization, transport and excitation of the elements Al, B, Cu and Cr

International Nuclear Information System (INIS)

Alduan, F. A.; Roca, M.; Capdevila, C.

1979-01-01

The influences of the processes of vaporization, transport and excitation on the shape of the volatilization-excitation curves and on the values of the spectral-line intensities have been investigated in a method for the spectrographic determination of Al, B, Cu and Cr In ammonium bifluoride samples by direct current are excitation in Scribner type electrodes, with addition of different matrices (graphite, 63203, GeO 2 , MgO and Zn0). The reaction products in the electrode cavity have been identified by X-ray powder diffraction analysis and the percentages of vaporized and diffused element evaluated through analysis by total-burning spectrographic methods. In addition, the values of both the number of particles entering the discharge column and the transport efficiencies have been calculated. Thus, the origin of most observed differences has been explained. (Author) 11 refs

The evil of good is better: Making the case for basic life support transport for penetrating trauma victims in an urban environment.

Science.gov (United States)

Rappold, Joseph F; Hollenbach, Kathryn A; Santora, Thomas A; Beadle, Dania; Dauer, Elizabeth D; Sjoholm, Lars O; Pathak, Abhijit; Goldberg, Amy J

2015-09-01

Controversy remains over the ideal way to transport penetrating trauma victims in an urban environment. Both advance life support (ALS) and basic life support (BLS) transports are used in most urban centers. A retrospective cohort study was conducted at an urban Level I trauma center. Victims of penetrating trauma transported by ALS, BLS, or police from January 1, 2008, to November 31, 2013, were identified. Patient survival by mode of transport and by level of care received was analyzed using logistic regression. During the study period, 1,490 penetrating trauma patients were transported by ALS (44.8%), BLS (15.6%), or police (39.6%) personnel. The majority of injuries were gunshot wounds (72.9% for ALS, 66.8% for BLS, 90% for police). Median transport minutes were significantly longer for ALS (16 minutes) than for BLS (14.5 minutes) transports (p = 0.012). After adjusting for transport time and Injury Severity Score (ISS), among victims with an ISS of 0 to 30, there was a 2.4-fold increased odds of death (95% confidence interval [CI], 1.3-4.4) if transported by ALS as compared with BLS. With an ISS of greater than 30, this relationship did not exist (odds ratio, 0.9; 95% CI, 0.3-2.7). When examined by type of care provided, patients with an ISS of 0 to 30 given ALS support were 3.7 times more likely to die than those who received BLS support (95% CI, 2.0-6.8). Among those with an ISS of greater than 30, no relationship was evident (odds ratio, 0.9; 95% CI, 0.3-2.7). Among penetrating trauma victims with an ISS of 30 or lower, an increased odds of death was identified for those treated and/or transported by ALS personnel. For those with an ISS of greater than 30, no survival advantage was identified with ALS transport or care. Results suggest that rapid transport may be more important than increased interventions. Therapeutic study, level IV.

O termo estratégia: um conceito útil para a lingüística aplicada?

Directory of Open Access Journals (Sweden)

John Robert Schmitz

2001-02-01

Full Text Available

O termo estratégia é usado em certos casos na literatura especializada de lingüística aplicada sem muita precisão, pois, para alguns pesquisadores, ele é uma técnica; para outros, é método, de ensino e, para outros ainda, refere-se aos hábitos de estudo ou estilo cognitivo dos aprendizes. Outro problema é a pletora de estratégias propostas sem rigor na demarcação de diferenças: estratégias de comunicação (communication strategies, estratégias de aprendizagem (learning strategies, estratégias de aquisição (acquisition strategies e estratégias de ensino (teaching strategies. Apesar desses problemas, as pesquisas na área de estratégias são promissoras, já que o treinamento explícito em sua utilização ensina os aprendizes a: (i saber usar novas estratégias, (ii avaliar a eficiência de diferentes tipos; e (iii decidir quando é procedente transferir uma determinada estratégia para uma nova situação.

Bioclimatic transport stop: Urban equipment kit; Parada bioclimatica de transporte: Kit de equipamiento urbano

Energy Technology Data Exchange (ETDEWEB)

Machado, Maria V; Barroso, Helen; Bonvino, Michelangelo; Puerta, Marigabriela [Instituto de Investigaciones de la Facultad de Arquitectura de la Universidad del Zulia, Maracaibo (Venezuela)

2000-07-01

Related to the analysis of offer of the urban public transportation, quantity and quality variables are identified, finding in the last one, the related to bus stop designing and equipping. This is, which elements a bus stop has to count with for its insertion in the urban public transportation system: information for the user, bench, trash can, et cetera: generally omitting, relevant aspects that must be considerate in its design and insertion: 1) the urban public transport, 2) the climate variables and 3) renewable energy and environmental preservation. For this presentation, thermal evaluations were made, using a thermal analysis software on prototypes of urban public transportation bus stops existent in Maracaibo (1.6 Mhab.)-Venezuela, city characterized for its high sunning, which duration approximately the same between the day period and night period: and for a marine climate of temperature (27.70 Celsius degrees) and high relative humidity (75%), low precipitation (490 mm) and predominant nor-northeast winds. The year average values of solar radiation corresponds to 5,59 kw/m{sup 2} day for the global radiation, 3.53 kw/m{sup 2} day for the direct radiation (63.1%) and 2.06% kw/m{sup 2} day for the diffuse radiation (36.9%). The maximum average value was obtained in the month of March with 6.4 kw/m{sup 2} day and the minimum on October, 4.7 kw/m{sup 2} day. In the other hand calculations about energy consumption and CO{sub 2} emissions of the conventional bus stop were made. It is proposed a bus stop design conceptualized as the bioclimatic condenser of the urban equipment. Where beside to comply its clearly determined transportation functions, it can conjunct: 1) complementary urban service activities, depending to its categorization in the urban public transportation system of Maracaibo; 2) orientation; 3) regulator of the urban microclima; and 4) area insertion of these. [Spanish] Dentro de lo que corresponde al analisis de la oferta de transporte publico

La enseñanza del léxico del ELE: resultados de una encuesta sobre la metodología aplicada en el aula

Directory of Open Access Journals (Sweden)

De Miguel García, Mª Lourdes

2005-11-01

Full Text Available Este artículo evalúa la metodología aplicada en el aula relacionada con la enseñanza del léxico español como lengua extranjera. El estudio se llevó a cabo mediante encuestas realizadas a personal docente de varias universidades y centros privados españoles. El análisis de los resultados nos indica que solo un tercio del profesorado aplica principios metodológicos sólidos y experimentados. Finalmente, se propone que la tarea de la enseñanza y el aprendizaje del léxico sea afrontada de un modo sistemático y planificado.

Enhanced thermoelectric transport in modulation-doped GaN/AlGaN core/shell nanowires

International Nuclear Information System (INIS)

Song, Erdong; Martinez, Julio A; Li, Qiming; Pan, Wei; Wang, George T; Swartzentruber, Brian

2016-01-01

The thermoelectric properties of unintentionally n-doped core GaN/AlGaN core/shell N-face nanowires are reported. We found that the temperature dependence of the electrical conductivity is consistent with thermally activated carriers with two distinctive donor energies. The Seebeck coefficient of GaN/AlGaN nanowires is more than twice as large as that for the GaN nanowires alone. However, an outer layer of GaN deposited onto the GaN/AlGaN core/shell nanowires decreases the Seebeck coefficient at room temperature, while the temperature dependence of the electrical conductivity remains the same. We attribute these observations to the formation of an electron gas channel within the heavily-doped GaN core of the GaN/AlGaN nanowires. The room-temperature thermoelectric power factor for the GaN/AlGaN nanowires can be four times higher than the GaN nanowires. Selective doping in bandgap engineered core/shell nanowires is proposed for enhancing the thermoelectric power. (paper)

Porous Fe21Cr7Al1Mo0.5Y metal supports for oxygen transport membranes: Thermo-mechanical properties, sintering and corrosion behaviour

DEFF Research Database (Denmark)

Glasscock, Julie; Mikkelsen, Lars; Persson, Åsa Helen

2013-01-01

and creep rates are sufficiently low. Ceramic interlayers with graded porosity and pore-size were applied and co-fired with the metal supports, producing substrates that were shown to be viable for a 3 μm dense Ce 0.8Gd0.2O1.9 - δ oxygen transport membrane deposited using sputtering. © 2013 Elsevier B.V....... are optimised simultaneously in-situ during sintering by controlling the growth rate of the oxide scale. Oxidation of metal supports with 20-40% porosity at 850 C and oxygen partial pressure of 10- 11 kPa showed sub-parabolic kinetics and stability over 3000 h. The FeCrAl steel shows vastly superior oxidation...... resistance compared with an FeCr steel of similar composition and porosity. Modelling of the alloy lifetime as a function of surface area and Al-content was performed, and lifetimes over 30 000 h are predicted for a metal support with 30% porosity operating at a temperature of 750 C, where the oxidation...

Nutrição aplicada à atividade motora Nutrition applied to motor activity

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Antonio Herbert Lancha Junior

2011-12-01

Full Text Available A Nutrição aplicada a atividade motora se divide em quatro áreas do movimento humano, a saber: esporte, educação física, dança, recreação/lazer. Essa definição conceitual diferencia a população alvo da intervenção nutricional. O organismo humano sempre apresentou o movimento como parte de sua atividade cotidiana e selecionou evolutivamente os organismos mais econômicos. Em contrapartida por conta de demandas, sociais, financeiras dentre outras a vida moderna impôs o sedentarismo como padrão de comportamento motor que aliado ao padrão genético de economia resultaram nas doenças modernas como obesidade, diabetes, etc. Assim a sociedade institucionalizou o movimento humano criando manifestações distintas descritas acima e suas necessidades específicas passaram a ser de interesse acadêmico/cientifico. Nutricionalmente os estudos se concentram no balanço energético, na necessidade de carboidratos, proteínas, lipídios assim como dos micronutrientes e outros compostos biologicamente ativos. Estes estudos definem estas substancias sob critérios de essencialidade ou efeito ergogênico superior a capacidade fisiológica. O primeiro determina mudanças nas necessidades nutricionais e o segundo substâncias consideradas ilícitas. No presente momento grande parte da comunidade cientifica dedicada à nutrição aplicada à atividade motora, dirige sua vocação na tentativa de descobrir as necessidades específicas provocadas pela pratica regular da atividade motora permitindo seu exercício regular para que a mesma propicie os benefícios na manutenção da saúde de forma plena nas quatro áreas descritas acima.Nutrition applied to motor activity is divided in four areas of human movement, namely: sports, physical education, dance, recreation/leisure. This conceptual definition differentiates the target population of nutritional intervention. The human body has always presented the movement as part of their daily activity and

Structural, magnetic and transport properties of Co2FeAl Heusler films with varying thickness

International Nuclear Information System (INIS)

Wang, Xiaotian; Li, Yueqing; Du, Yin; Dai, Xuefang; Liu, Guodong; Liu, Enke; Liu, Zhongyuan; Wang, Wenhong; Wu, Guangheng

2014-01-01

We report on a systematic study of the structural, magnetic properties and the anomalous Hall effect, in the Heusler alloy Co 2 FeAl (CFA) epitaxial films on MgO (001), as a function of film thickness. It was found that the epitaxial CFA films show a highly ordered B2 structure with an in-plane uniaxial magnetic anisotropy. The electrical transport properties reveal that the lattice and magnon scattering contributions to the longitudinal resistivity. Independent on the thickness of films, the anomalous Hall resistivity of CFA films is found to be dominated by skew scattering only. Moreover, the anomalous Hall resistivity shows weakly temperature dependent behavior, and its absolute value increases as the thickness decreases. We attribute this temperature insensitivity in the anomalous Hall resistivity to the weak temperature dependent of tunneling spin-polarization in the CFA films, while the thickness dependence behavior is likely due to the increasing significance of interface or free surface electronic states. - Highlights: ●Highly ordered CFA films with various thicknesses were prepared on MgO substrates. ●The magnon scattering contributions to the longitudinal resistivity in the CFA films. ●The anomalous Hall resistivity of the CFA films shows weakly temperature dependent. ●The CFA films show weak temperature dependent of tunneling spin-polarization

Enhanced electrochemical performance of CoAl-layered double hydroxide nanosheet arrays coated by platinum films

International Nuclear Information System (INIS)

Cheng, J.P.; Fang, J.H.; Li, M.; Zhang, W.F.; Liu, F.; Zhang, X.B.

2013-01-01

Graphical abstract: Schematic illustration for the electron transport between the current collector and the active CoAl LDH arrays, where the yellow arrows indicate the high resistance of CoAl LDH, while the green arrows present the high conductivity of Pt films on LDH. -- Highlights: •CoAl layered double hydroxide nanosheet arrays are synthesized by hydrothermal method. •Pt films coated on surface of CoAl nanosheets facilitate fast electron transport. •CoAl LDH nanosheets coated with Pt film for 5 min have an excellent performance. -- Abstract: Three-dimensional network of cobalt and aluminum layered double hydroxide (LDH) nanosheets was synthesized on nickel foam by a simple hydrothermal method. The CoAl-LDH nonosheets were subsequently coated by ion sputtering with thin layers of Pt films to facilitate fast electron transport between current collector and the CoAl-LDH active materials. The optimal thickness of the Pt film acquiring the best performance was identified by applying various sputtering time in controlled experiments. The supercapacitor built by the CoAl-LDH nanosheets coated with Pt film sputtered for 5 min has a high specific capacitance (734.4 F g −1 at 3 A g −1 ), excellent rate capability as well as cycling stability. Moreover, it showed a long life of 77% retention after 6000 cycles and its general morphology was preserved after the test. The synergetic affect of conductive layer of Pt films and CoAl-LDH on the improvement of electrochemical properties was discussed and this would provide a useful clue in designing novel and effective electrode materials for supercapacitors

Una interpretación del impacto de las maquiladoras en el bienestar familiar y en el desarrollo regional

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Mario M. Carrillo Huerta

1990-01-01

Full Text Available En este trabajo se presenta una evaluación de los impactos de las maquiladoras en las condiciones de vida de la comunidad. Las apreciaciones referentes al impacto de la maquila en el bienestar familiar se basan en una muestra aplicada a 1,200 trabajadores en 4 ciudades. Los resultados obtenidos parecen indicar que, en términos generales y en relación con algunas variables de bienestar, la situación de los trabajadores ha mejorado como consecuencia de su empleo en la maquiladora. No obstante, existen diferencias entre las variables consideradas, pues mientras los puntajes más altos corresponden a alimentación y vestido, los más bajos se encontraron en vivienda, transporte y servicios de salud.

Four-atom period in the conductance of monatomic al wires

DEFF Research Database (Denmark)

Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

2003-01-01

We present first-principles calculations based on density functional theory for the conductance of monatomic Al wires between Al(111) electrodes. In contrast to the even-odd oscillations observed in other metallic wires, the conductance of the Al wires is found to oscillate with a period of four ...... atoms as the length of the wire is varied. Although local charge neutrality can account for the observed period, it leads to an incorrect phase. We explain the conductance behavior using a resonant transport model based on the electronic structure of the infinite wire....

The hydraulic transportation of thickened sludges

African Journals Online (AJOL)

driniev

non-Newtonian sludges (Xu et al., 1993; Spinosa and Lotita, 2001; .... [11]. Analysis and typical applications. Laminar/turbulent transition. For most sewage sludges the ... on Transport and Sedimentation of Solid Particles - Ghent, September.

retardo de transporte

Directory of Open Access Journals (Sweden)

Paola Niño-Suárez

2006-01-01

Full Text Available En este trabajo se presenta la obtención del modelo exacto en tiempo discreto de un robot móvil tipo (2,0, bajo la consideración de la existencia de retardos de transporte en la señal de control, producidos por la propagación de las señales entre los sensores y actuadores del robot y el control remoto. El modelo obtenido es evaluado mediante simulación, comparando su desempeño con un modelo discreto aproximado que incluye también retardos de transporte y con el modelo en tiempo continuo del mismo sistema.

Fenómenos de transporte : un curso introductorio

OpenAIRE

Betancourt Grajales, Ramiro

1991-01-01

Fenómenos de transporte, es el nombre colectivo que se da al estudio sistemático e integrado de tres áreas clásicas de la ciencia de la Ingeniería : 1) Transporte de Energía o Calor, 2) Transporte de Masa o Difusión, y 3) Transporte de Cantidad de Movimiento o Impulso (Momentum en Inglés), o Dinámica de Fluidos. Debido a que con frecuencia el transporte de masa y de calor ocurren en un fluido, algunos planes de estudio incluyen estos procesos en su tratamiento de la mecánica de fluidos....

Generación automática de variantes de trayectorias aplicada al diseño óptimo bajo criterios múltiples de redes hidráulicas de abasto.

Directory of Open Access Journals (Sweden)

J. R. Hechavarría Hernández

2007-05-01

Full Text Available La determinación de las trayectorias más eficientes que deben tener las redes, instalaciones o vías de transporte es un problema que motiva a muchos investigadores de diversas ingenierías: informática, civil, mecánica, hidráulica, etc., cuyas soluciones requieren ser realizadas sobre la base de la elevada integración de la información durante el proceso de análisis y estudio de la tarea, de la aplicación de los métodos modernos de preparación y toma de decisiones, así como la organización racional de los procedimientos de cálculo de ingeniería. Para definir el trazado de trayectorias en los proyectos de ingeniería se tienen en cuenta determinadas condiciones propias del entorno. Estas trayectorias, pese a su diferente designación, pueden coincidir en determinadas zonas y compartir espacios limitados. Por esta razón, un sistema para la generación automática de variantes de trayectorias deberá considerar las limitaciones del espacio disponible al establecer el tipo y dimensiones límites. En el artículo se presenta un procedimiento que apoyado en un sistema informático permite obtener de manera automática variantes de trayectorias cerradas las cuales dependiendo de su destino de servicio serán optimizadas bajo criterios de eficiencias.Determining the most efficient trajectories of networks, installations or transportation roads is a problem to a lot of investigators of different fields: Computer Science, Civil Engineering, Mechanical Engineering, Hydraulics, etc. Solutions should be carried out taking into account a high integration of information in the analysis and study process of the task, the application of the modern methods of preparation and decision making, as well as the rational organization of the procedures of engineering calculation. Several conditions regarding the surroundings are taken into account in engineering projects while defining the layout of trajectories. These trajectories, in spite of their

Rotina computacional e equação simplificada para modelar o transporte de sedimentos num Latossolo Vermelho Distrófico Computational routine and simplified equation for modeling sediment transport capacity in a Dystrophic Hapludox

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Gilmar E. Cerquetani

2006-08-01

Full Text Available Os objetivos do presente trabalho foram desenvolver rotina computacional para a solução da equação de Yalin e do diagrama de Shields e avaliar uma equação simplificada para modelar a capacidade de transporte de sedimento num Latossolo Vermelho Distrófico que possa ser utilizada no Water Erosion Prediction Project - WEPP, assim como em outros modelos de predição da erosão do solo. A capacidade de transporte de sedimento para o fluxo superficial foi representada como função-potência da tensão cisalhante, a qual revelou ser aproximação da equação de Yalin. Essa equação simplificada pôde ser aplicada em resultados experimentais oriundos de topografia complexa. A equação simplificada demonstrou acuracidade em relação à equação de Yalin, quando calibrada utilizando-se da tensão média cisalhante. Testes de validação com dados independentes demonstraram que a equação simplificada foi eficiente para estimar a capacidade de transporte de sedimento.The objectives of the present work were to develop a computational routine to solve Yalin equation and Shield diagram and to evaluate a simplified equation for modeling sediment transport capacity in a Dystrophic Hapludox that could be used in the Water Erosion Prediction Project - WEPP, as well as other soil erosion models. Sediment transport capacity for shallow overland flow was represented as a power function of the hydraulic shear stress and which showed to be an approximation to the Yalin equation for sediment transport capacity. The simplified equation for sediment transport could be applied to experimental data from a complex topography. The simplified equation accurately approximated the Yalin equation when calibrated using the mean hydraulic shear stress. Validation tests using independent data showed that the simplified equation had a good performance in predicting sediment transport capacity.

PREFACE: Transport phenomena in proton conducting media Transport phenomena in proton conducting media

Science.gov (United States)

Eikerling, Michael

2011-06-01

, charge-bearing species at interfaces and porous host materials on proton transport properties. As a common thread, articles in this special issue contribute to understanding the functionality provided by complex materials, beyond hydrogen bond fluctuations in water. The first group of articles (Smirnov et al, Henry et al, Medvedev and Stuchebrukhov) elucidates various aspects of the impact of local structural fluctuations, hydrogen bonding and long-range electrostatic forces on proton transfer across and at the surface of mitochondrial membranes. The second group of articles (Ilhan and Spohr, Allahyarov et al and Idupulapati et al) employ molecular dynamics simulations to rationalize vital dependencies of proton transport mechanisms in aqueous-based polymer electrolyte membranes on the nanoporous, phase-separated ionomer morphology, and on the level of hydration. The articles by Gebel et al, Boillat et al, and Aleksandrova et al employ small angle neutron scattering, neutron radiography, and electrochemical atomic force microscopy, respectively, to obtain detailed insights into the kinetics of water sorption, water distribution, water transport properties, as well as spatial maps of proton conductivity in fuel cell membranes. The contribution of Paschos et al provides a comprehensive review of phosphate-based solid state protonic conductors for intermediate temperature fuel cells. The topic of proton conductive materials for high-temperature, water-free operation of fuel cells is continued in the article of Verbraeken et al which addresses synthesis and characterization of a proton conducting perovskite. The guest editor wishes to acknowledge and thank all contributing authors for their commitment to this special issue. Moreover, I would like to thank the staff at IOP Publishing for coordinating submission and refereeing processes. Finally, for the readers, I hope that this special issue will be a valuable and stimulating source of insights into the versatile and

Biotecnología aplicada a la mejora de "pelargonium"

OpenAIRE

Alonso Gómez, Mercedes

2002-01-01

El trabajo se ha centrado en el género Pelargonium y en especial en el gerario zonal (Pelargonium x hortorum Bailey) debido al interés de esta planta como ornamental y a la disminución de la diversidad genética de esta especie debido al ataque masivo que está sufriendo por el taladro del geranio (Cacyreus marshalii Butler) en toda la Península y Baleares. La pérdida de los explantes iniciales debido a la oxidación fenólica se ha reducido lavando el material vegetal con una solución antioxidan...

NORMAS BRASILEIRAS E INTERNACIONAIS DE CONTABILIDADE APLICADAS AO SETOR PÚBLICO E O DESAFIO DA CONVERGÊNCIA: UMA ANÁLISE COMPARATIVA – IPSAS E NBCTSP

Directory of Open Access Journals (Sweden)

Adriana Rodrigues Fragoso

2012-11-01

Full Text Available O presente estudo tem por objetivo analisar o estágio atual de convergência conceitual entre as normas brasileiras de contabilidade aplicadas ao setor público (NBCTSP e as International Public Sector Accounting Standard (IPSAS. A complexidade e diversidade de transações entre entidades do setor público ou privado, gerada pela internacionalização de mercados, demandam uma avaliação contínua e dinâmica dos eventos que promovem a modificação quantitativa ou qualitativa de um patrimônio. Para esse processo de avaliação, a observação dos princípios e normas de contabilidade é importante para garantir, entre outras características da informação, a compreensibilidade e comparabilidade, reduzindo custos aos investidores e usuários, em geral, considerando as barreiras encontradas na diversidade de idiomas, culturas, políticas fiscais e econômicas. Para a análise de convergência, foi efetuado um estudo comparativo do conteúdo das normas, a partir de uma análise descritiva, com o intuito de verificar a aderência existente entre as normas brasileiras e internacionais aplicadas ao setor público. Os resultados encontrados destacam que ainda há diversos aspectos a serem discutidos para uma efetiva convergência às normas internacionais; esta convergência atual é parcial. No entanto, verifica-se que as NBCTSPs apresentam uma exposição conceitual de qualidade enquanto as IPSAS apresentam um conteúdo mais focado em procedimentos operacionais.

Postguerra y contracultura. Identidades en la ética aplicada

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López de la Vieja de la Torre, M. Teresa

2006-12-01

Full Text Available The article analyses the role of cultural identities in Applied Ethics. Biotechnologies have been actually valued from different perspectives in Europe and in the United States. Since Nazi research and the politics of racial hygiene have shown the role of science under dictatorship. Nazi Doctors acted as soldiers. Therefore The Nürnberg Code claimed respect for human rights in Medicine, to protect individuals in clinical research. However American Doctors considered the Code suitable for a different context. Norms for a “barbaric” research, far away from the American standards. But in the United States radiations experiments have ignored laws and moral standards. Decades later, the Constitutional Treaty for the European Union emphasizes the value of dignity and personal integrity in the fields of Medicine and Biology. The informed consent and the prohibition of Eugenics connect then the future and the past.El artículo analiza el papel de las identidades culturales en la Ética aplicada. Las biotecnologías han sido valoradas efectivamente desde distintas perspectivas, en Europa y en Estados Unidos. Pues la investigación y la política de higiene racial durante el Nacionalsocialismo mostraron el papel desempeñado por la ciencia en la dictadura. Los médicos nazis actuaron como soldados. Por ello, el Código de Nürnberg reclamó respecto por los derechos humanos en Medicina, a fin de proteger a los ciudadanos en la investigación. Los médicos norteamericanos consideraron que el Código era adecuado para otro contexto, sin embargo. Normas para una investigación “bárbara”, alejada de los estándares americanos. Pero en Estados Unidos los experimentos con radiación ignoraron leyes y estándares morales. Décadas mas tarde, el Tratado constitucional para la Unión Europea insiste en el valor de la dignidad y de la integridad personal en Medicina y Biología. El consentimiento informado y la prohibición de practicas eugen

La gestión del conocimiento como generador de competitividad: Aplicación en pymes de la zona metropolitana de Guadalajara

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José Sánchez Gutiérrez

2016-02-01

El resultado final, al que se llegó gracias al análisis multivariable de los datos obtenidos en las encuestas aplicadas, es que en las empresas analizadas no existe un grado aceptable de gestión del conocimiento, por lo que su nivel de competitividad es bajo. actividades de creación de conocimiento

Comparative study of initial growth stage in PVT growth of AlN on SiC and on native AlN substrates

Energy Technology Data Exchange (ETDEWEB)

Epelbaum, B.M.; Heimann, P.; Bickermann, M.; Winnacker, A. [Department of Materials Science 6, University of Erlangen-Nuernberg, Martensstr. 7, 91058 Erlangen (Germany)

2005-05-01

The main issue in homoepitaxial growth of aluminum nitride (AlN) on native seed substrates appears to be aluminum oxynitride poisoning of seed surface leading to polycrystalline growth at 1750-1850 C. This is well below the lowest growth temperature appropriate for physical vapor transport (PVT) of bulk AlN, which is about 2150 C. Contrary, heteroepitaxial growth of AlN on SiC is relatively easy to achieve because of natural formation of a thin molten layer on the seed surface and VLS growth of AlN via the molten buffer layer. The most critical issue of AlN growth on SiC is cracking of the grown layer upon cooling as a result of different thermal expansion. Optimization of seeded growth process can be achieved by proper choice of SiC seed orientation and by use of ultra-pure starting material. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Dual and Direction-Selective Mechanisms of Phosphate Transport by the Vesicular Glutamate Transporter

Directory of Open Access Journals (Sweden)

Julia Preobraschenski

2018-04-01

Full Text Available Summary: Vesicular glutamate transporters (VGLUTs fill synaptic vesicles with glutamate and are thus essential for glutamatergic neurotransmission. However, VGLUTs were originally discovered as members of a transporter subfamily specific for inorganic phosphate (Pi. It is still unclear how VGLUTs accommodate glutamate transport coupled to an electrochemical proton gradient ΔμH+ with inversely directed Pi transport coupled to the Na+ gradient and the membrane potential. Using both functional reconstitution and heterologous expression, we show that VGLUT transports glutamate and Pi using a single substrate binding site but different coupling to cation gradients. When facing the cytoplasm, both ions are transported into synaptic vesicles in a ΔμH+-dependent fashion, with glutamate preferred over Pi. When facing the extracellular space, Pi is transported in a Na+-coupled manner, with glutamate competing for binding but at lower affinity. We conclude that VGLUTs have dual functions in both vesicle transmitter loading and Pi homeostasis within glutamatergic neurons. : Preobraschenski et al. show that the vesicular glutamate transporter functions as a bi-directional phosphate transporter that is coupled with different cations in each direction and hence may play a key role in neuronal phosphate homeostasis. Keywords: VGLUT, SLC17 family, type I Na+-dependent inorganic phosphate transporter, ATPase, proteoliposomes, hybrid vesicles, anti-VGLUT1 nanobody

Intrathecal infusion of a Ca(2+)-permeable AMPA channel blocker slows loss of both motor neurons and of the astrocyte glutamate transporter, GLT-1 in a mutant SOD1 rat model of ALS.

Science.gov (United States)

Yin, Hong Z; Tang, Darryl T; Weiss, John H

2007-10-01

Elevated extracellular glutamate, resulting from a loss of astrocytic glutamate transport capacity, may contribute to excitotoxic motor neuron (MN) damage in ALS. Accounting for their high excitotoxic vulnerability, MNs possess large numbers of unusual Ca(2+)-permeable AMPA channels (Ca-AMPA channels), the activation of which triggers mitochondrial Ca(2+) overload and strong reactive oxygen species (ROS) generation. However, the causes of the astrocytic glutamate transport loss remain unexplained. To assess the role of Ca-AMPA channels on the evolution of pathology in vivo, we have examined effects of prolonged intrathecal infusion of the Ca-AMPA channel blocker, 1-naphthyl acetylspermine (NAS), in G93A transgenic rat models of ALS. In wild-type animals, immunoreactivity for the astrocytic glutamate transporter, GLT-1, was particularly strong around ventral horn MNs. However, a marked loss of ventral horn GLT-1 was observed, along with substantial MN damage, prior to onset of symptoms (90-100 days) in the G93A rats. Conversely, labeling with the oxidative marker, nitrotyrosine, was increased in the neuropil surrounding MNs in the transgenic animals. Compared to sham-treated G93A animals, 30-day NAS infusions (starting at 67+/-2 days of age) markedly diminished the loss of both MNs and of astrocytic GLT-1 labeling. These observations are compatible with the hypothesis that activation of Ca-AMPA channels on MNs contributes, likely in part through oxidative mechanisms, to loss of glutamate transporter in surrounding astrocytes.

La eco-epidemiología retrospectiva como herramienta aplicada a la vigilancia de la leishmaniasis en Misiones, Argentina, 1920-2014

Directory of Open Access Journals (Sweden)

Oscar Daniel Salomón

Full Text Available RESUMEN Se presenta una metodología analítica retrospectiva, basada en el marco teórico de la eco-epidemiología, anclada en una escala espacial subnacional. Esta metodología, aplicada aquí a la caracterización de escenarios de transmisión de la leishmaniasis en la provincia argentina de Misiones —fronteriza con Brasil y Paraguay— permitió fundamentar recomendaciones de vigilancia y control apropiadas a dicha escala. Se realizó una búsqueda exhaustiva de la literatura sobre leishmaniasis en esa provincia y se determinaron tres escenarios de transmisión de leishmaniasis cutánea (LC y visceral (LV, correspondientes a tres períodos: 1920-1997, en el que se constató la transmisión de LC, dispersa en el tiempo y el espacio; 1998-2005, en el que hubo brotes focales de LC; y 2006-2014 en el que, además, se registraron brotes y se documentó la dispersión geográfica de la LV. Para caracterizar los escenarios de riesgo y los procesos antrópicos que los producen, los resultados se sintetizaron e integraron en el contexto socio-histórico y bio-ecológico de cada período analizado. Se fundamentan recomendaciones de vigilancia y control en el territorio estudiado, entre ellas, establecer una vigilancia activa para monitorear posibles tendencias al incremento de la circulación parasitaria y vectorial y, ante la aparición de un foco, realizar estudios para verificar la transmisión autóctona y la intensidad del evento. Además, se debe establecer la obligación legal de tomar medidas adicionales de control por los responsables de los proyectos que impliquen modificación ambiental, como la realización de estudios de evaluación del riesgo de transmisión, y acciones de mitigación del riesgo, detección temprana y tratamiento oportuno de los casos.

Ultra-violet absorption induced modifications in bulk and nanoscale electrical transport properties of Al-doped ZnO thin films

Energy Technology Data Exchange (ETDEWEB)

Kumar, Mohit; Basu, Tanmoy; Som, Tapobrata, E-mail: tsom@iopb.res.in [SUNAG Laboratory, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India)

2015-08-07

Using conductive atomic force microscopy and Kelvin probe force microscopy, we study local electrical transport properties in aluminum-doped zinc oxide (ZnO:Al or AZO) thin films. Current mapping shows a spatial variation in conductivity which corroborates well with the local mapping of donor concentration (∼10{sup 20 }cm{sup −3}). In addition, a strong enhancement in the local current at grains is observed after exposing the film to ultra-violet (UV) light which is attributed to persistent photocurrent. Further, it is shown that UV absorption gives a smooth conduction in AZO film which in turn gives rise to an improvement in the bulk photoresponsivity of an n-AZO/p-Si heterojunction diode. This finding is in contrast to the belief that UV absorption in an AZO layer leads to an optical loss for the underneath absorbing layer of a heterojunction solar cell.

The Advanced Light Source (ALS) Radiation Safety System

International Nuclear Information System (INIS)

Ritchie, A.; Oldfather, D.; Lindner, A.

1993-05-01

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 GeV synchrotron light source facility consisting of a 120 keV electron gun, 50 MeV linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies

Effect of allyl alcohol on hepatic transporter expression: Zonal patterns of expression and role of Kupffer cell function

International Nuclear Information System (INIS)

Campion, Sarah N.; Tatis-Rios, Cristina; Augustine, Lisa M.; Goedken, Michael J.; Rooijen, Nico van; Cherrington, Nathan J.; Manautou, Jose E.

2009-01-01

During APAP toxicity, activation of Kupffer cells is critical for protection from hepatotoxicity and up-regulation of multidrug resistance-associated protein 4 (Mrp4) in centrilobular hepatocytes. The present study was performed to determine the expression profile of uptake and efflux transporters in mouse liver following treatment with allyl alcohol (AlOH), a periportal hepatotoxicant. This study also investigated the role of Kupffer cells in AlOH hepatotoxicity, and whether changes in transport protein expression by AlOH are dependent on the presence of Kupffer cells. C57BL/6J mice received 0.1 ml clodronate liposomes to deplete Kupffer cells or empty liposomes 48 h prior to dosing with 60 mg/kg AlOH, i.p. Hepatotoxicity was assessed by plasma ALT and histopathology. Hepatic transporter mRNA and protein expression were determined by branched DNA signal amplification assay and Western blotting, respectively. Depletion of Kupffer cells by liposomal clodronate treatment resulted in heightened susceptibility to AlOH toxicity. Exposure to AlOH increased mRNA levels of several Mrp genes, while decreasing organic anion transporting polypeptides (Oatps) mRNA expression. Protein analysis mirrored many of these mRNA changes. The presence of Kupffer cells was not required for the observed changes in uptake and efflux transporters induced by AlOH. Immunofluorescent analysis revealed enhanced Mrp4 staining exclusively in centrilobular hepatocytes of AlOH treated mice. These findings demonstrate that Kupffer cells are protective from AlOH toxicity and that induction of Mrp4 occurs in liver regions away from areas of AlOH damage independent of Kupffer cell function. These results suggest that Kupffer cell mediators do not play a role in mediating centrilobular Mrp4 induction in response to periportal damage by AlOH

ANÁLISE DAS NORMAS BRASILEIRAS DE CONTABILIDADE APLICADAS AO SETOR PÚBLICO (NBCASP: UM ESTUDO NAS UNIDADES DA FEDERAÇÃO DO BRASIL

Directory of Open Access Journals (Sweden)

Francisca Francivânia Rodrigues Ribeiro Macêdo

2014-06-01

Full Text Available O objetivo deste estudo é descrever a aderência das Unidades da Federação do Brasil às Normas Brasileiras de Contabilidade Aplicadas ao Setor Público. A metodologia utilizada na pesquisa configura–se como descritiva, com abordagem qualitativa, realizada por meio de pesquisa documental. Os dados da pesquisa revelam que no exercício de 2010, 2011 e 2012 o disclosure dos órgãos públicos do Estado no que concerne à aderência às Normas Brasileiras de Contabilidade Aplicadas ao Setor Público (NBCASP que convergem com as International Public Sector Accounting Standard (IPSAS ainda é incipiente. Ressalta-se que pontos importantes constantes nas normas NBCT 16.3 e NBCT 16.8, que versam, respectivamente, sobre a divulgação do PPA, LDO e Controle Interno ainda não são respeitados, mesmo que tais itens tenham sua divulgação obrigatória exigida na Constituição Federal e pela Lei de Responsabilidade Fiscal. Observou-se também que das 27 unidades federativas, apenas os Estados de Minas Gerais, Maranhão, Rio Grande do Norte, Sergipe, Bahia, Acre, Amazonas, Roraima, Tocantins, Goiás, Mato Grosso e Mato Grosso do Sul não evidenciaram a conta intitulada intangível. Nenhum dos Estados evidenciou a Demonstração do Fluxo de Caixa e a Demonstração do Resultado Econômico ou se mencionou algo sobre o sistema de custos ou a avaliação das disponibilidades e direitos e títulos de crédito. Conclui-se que os Estados brasileiros ainda não estão preparados para iniciar a divulgação obrigatória segundo as NBCASP, dado o nível de disclosure evidenciado até o momento.

Booster extraction, booster-to-storage ring transport and storage ring injection for the ALS

International Nuclear Information System (INIS)

Zisman, M.S.

1988-03-01

A status report on the design of the ALS injection system is presented. The various modifications that have occurred since the time of the ALS Conceptual Design Report in July, 1986 are described, along with the reasons for the changes. 1 ref., 12 figs

Report 1986/1987. Department of Nuclear Engineering and Applied Research; Informe 1986/1987. Departamento de Ingenieria Nuclear e Investigacion Aplicada

Energy Technology Data Exchange (ETDEWEB)

1990-12-31

The objective of the Department of Applied Research is to carry out research on fields of physics, materials sciences, chemistry and engineering. Some branches of research can be mentioned: high Tc superconductors, hydrogen storage in metallic hydrides, extractive metallurgy of strategic minerals and others. In the first case, both the Development Division and the Thermodynamics group in the Metallurgy Division, have actively participated. [Espanol] El Dpto. de Investigacion Aplicada tiene como objetivo realizar investigacion en campos de la fisica, ciencias de materiales, quimica e ingenieria. Se pueden citar nuevas lineas de trabajo, entre ellos: los superconductores ceramicos de alta temperatura critica, el almacenamiento de hidrogeno en hidruros metalicos, el desarrollo de una servo-cuna computarizada, la metalurgia extractiva de materiales estrategicos y otros. En el primer caso han participado activamente la Div. Desarrollo y el Grupo de Termodinamica de la Division Metalurgia.

Oxygen transport properties estimation by DSMC-CT simulations

Energy Technology Data Exchange (ETDEWEB)

Bruno, Domenico [Istituto di Metodologie Inorganiche e dei Plasmi, Consiglio Nazionale delle Ricerche - Via G. Amendola, 122 - 70125 Bari (Italy); Frezzotti, Aldo; Ghiroldi, Gian Pietro [Dipartimento di Scienze e Tecnologie Aerospaziali, Politecnico di Milano - Via La Masa, 34 - 20156 Milano (Italy)

2014-12-09

Coupling DSMC simulations with classical trajectories calculations is emerging as a powerful tool to improve predictive capabilities of computational rarefied gas dynamics. The considerable increase of computational effort outlined in the early application of the method (Koura,1997) can be compensated by running simulations on massively parallel computers. In particular, GPU acceleration has been found quite effective in reducing computing time (Ferrigni,2012; Norman et al.,2013) of DSMC-CT simulations. The aim of the present work is to study rarefied Oxygen flows by modeling binary collisions through an accurate potential energy surface, obtained by molecular beams scattering (Aquilanti, et al.,1999). The accuracy of the method is assessed by calculating molecular Oxygen shear viscosity and heat conductivity following three different DSMC-CT simulation methods. In the first one, transport properties are obtained from DSMC-CT simulations of spontaneous fluctuation of an equilibrium state (Bruno et al, Phys. Fluids, 23, 093104, 2011). In the second method, the collision trajectory calculation is incorporated in a Monte Carlo integration procedure to evaluate the Taxman’s expressions for the transport properties of polyatomic gases (Taxman,1959). In the third, non-equilibrium zero and one-dimensional rarefied gas dynamic simulations are adopted and the transport properties are computed from the non-equilibrium fluxes of momentum and energy. The three methods provide close values of the transport properties, their estimated statistical error not exceeding 3%. The experimental values are slightly underestimated, the percentage deviation being, again, few percent.

On the growth of Al2O3 scales

International Nuclear Information System (INIS)

Heuer, A.H.; Nakagawa, T.; Azar, M.Z.; Hovis, D.B.; Smialek, J.L.; Gleeson, B.; Hine, N.D.M.; Guhl, H.; Lee, H.-S.; Tangney, P.; Foulkes, W.M.C.; Finnis, M.W.

2013-01-01

unambiguous evidence for both O and Al countercurrent transport in Al 2 O 3 scale-forming alloys. We postulate that such transport is mediated by migration of grain boundary disconnections containing charged jogs, rather than by jumping of isolated point defects in random high-angle grain boundaries

Growth optimization and characterization of high mobility two-dimensional electron systems in AlAs quantum wells

Energy Technology Data Exchange (ETDEWEB)

Dasgupta, Shivaji

2009-02-15

In this work two-dimensional electron systems (2DESs) based on AlAs/AlGaAs heterostructures doped with Si are investigated. The electrons are confined in AlAs quantum wells (QWs) sandwiched between AlGaAs buffers. Analytical calculations and simulations for AlAs QWs are presented in the first chapter. The results show a cross-over width, above which the wide (001)-oriented QWs show double valley occupancy and wide (110)-oriented QWs show single valley occupancy. We solve the Schroedinger equation analytically for anisotropic masses. The solution shows the orientation dependence of the elliptical cyclotron orbit due to the anisotropic mass. We also present an introduction to the Landau level crossings based on g{sup *}m{sup *} product. In the next chapter, we present experimental results for the double-valley (001)-oriented AlAs QWs. We present the different structures of the deep AlAs QWs along with the low temperature magnetotransport data for these QWs. Thereafter, we present the results on shallow AlAs QWs. We achieved a mobility of 4.2 x 10{sup 5} cm{sup 2}/Vs at 330 mK for the deep backside doped AlAs QW. For the shallow QWs, we achieved a mobility of2.3 x 10{sup 5} cm{sup 2}/Vs at 330 mK, for a density of 2.9 x 10{sup 11} cm{sup -2}. From the magneto-transport data, we see evidence of the double-valley occupation for the (001)-oriented AlAs wide QWs. In the next chapter, we present experimental results for the single-valley (110)-oriented AlAs QWs. We deduced the donor binding energy and the doping efficiency for this facet from a doping series of double-sided doped QWs. Thereafter, we designed different structures for the (110)-oriented AlAs QWs, which we present along with their respective low temperature magneto-transport data. We measured one of the double-sided doped AlAs QWs at very high magnetic fields and low temperatures, down to 60 mK. At the end of the chapter, we present a spike feature observed in the magneto-transport data of these QWs. This

Ambientes virtuales y colaborativos de aprendizaje. Su aplicación al curso BioPython

Directory of Open Access Journals (Sweden)

Jenny Navas Muñoz

2006-01-01

Full Text Available El siguiente documento permite examinar la tecnología aplicada a la educación virtual y la educación a distancia con relación a la metodología del curso-taller BioPython donde se hace necesario el uso aspectos colaborativos (groupware technology para la enseñanza y el aprendizaje. El objetivo del curso-taller BioPython1 es enseñar a programar a biólogos, a diseñar algoritmos y expresarlos como programas escritos en un lenguaje de programación para poder ejecutarlos en un computador. La estructura del presente documento es como sigue, inicialmente se da una introducción al contenido tocando temas tales como aspectos metodológicos relativos a la educación virtual y a distancia. Las características de los ambientes colaborativos que soportan estas tareas se abordarán en la segunda sección, un caso particular de estudio será descrito en la tercera sección. El escenario será el curso-taller Python para biólogos que tuvo lugar en CIAT en el mes de diciembre.

Del Gabinete Científico al Aprendizaje Interactivo: el Museo Alfredo Dugès Del Gabinete Científico al Aprendizaje Interactivo: el Museo Alfredo Dugès

Directory of Open Access Journals (Sweden)

Gloria Eugenia Magaña-Cota

2012-02-01

Full Text Available Se presenta un estudio que da cuenta de las estrategias con que un museo universitario de Ciencias Naturales, a la vez que busca divulgar la ciencia, responde al reto del paradigma “ver y tocar”. En el curso de este texto se evalúa el aprendizaje de una serie de acciones a través de la atracción al contacto humano. Las estrategias aplicadas parten del contenido de los programas escolares de enseñanza, y buscan su efectividad tras acercar al visitante a la ciencia por primera vez. De esta forma, las actividades permiten multiplicar el público, enriquecer su aprendizaje, aumentar su comprensión y valoración de los avances científicos y tecnológicos; asimismo, ofrecen experiencias que incentivan las labores científicas. En estas condiciones se perfila el reto por desarrollar otras actividades que permitan formar un público leal y permanente, cuyo gusto por las Ciencias Naturales y la ciencia en general sea sólido. A case study is presented which illustrates the strategies employed by a university sponsored natural science museum in meeting the challenge posed by the “hands-on” model in its efforts to bring scientific knowledge to the general public. The extent to which a series of actions are learned, assisted by the attraction that the opportunity to touch provides, is evaluated. The strategies employed are aligned to the general school curriculum and seek to be effective in attracting newcomers to the world of science. Such strategies provide for increased museum attendance, whilst enriching the learning process and enhancing the public’s understanding and appreciation of scientific and technological advances. They also offer a range of experiences to encourage involvement in scientific activity. Furthermore, we take a brief look at the challenge of developing activities aimed at creating a loyal and permanent public with a concrete interest in science in general and the natural sciences in particular.

Transportation Research – Safety and Sustainability

Indian Academy of Sciences (India)

of traditional urban and transport planning 'growth of mobility', 'travel time saving by ... This is why road and driver education programmes have been ... The last paper in the volume by Mukherjee et al illustrates the use of modern modelling.

Enhancement of photoresponse property of perovskite solar cell by aluminium chloride (AlCl3)

Science.gov (United States)

Ghosh, S. S.; Sil, A.

2018-05-01

The fabrication of a three layer solar cell device is a new area of research. The formation of perovskite phase is evident from x-ray diffraction and its particle size is observed by microstructural analysis. A thin layer of gold coating over the device increases the surface conductivity. Direct contact between a SnCl2 or AlCl3 based perovskite with the gold coating increases the durability of the film but decreases the hole transport properties due to absence of an organic hole transport material. The absorbance spectroscopy analysis gives characteristic peaks showing the evidence of ITO, TiO2 (rutile) and Sn2+ complexes present in the Sn-perovskite film or Al3+ complexes present within the Al-perovskite cell. The desired absorbance near 550 nm due to Al3+ complexes causes a much higher flow of current on illumination and thus is also evidenced by the presence of comparatively high intensity PL spectra in the Al-perovskite system which occurred due to free exciton formation near band edge excitation. The fill factor of the devices is estimated as ∼0.83 and ∼0.65 for Sn-perovskite and Al-perovskite devices respectively. The PCE values of Sn-perovskite and Al-perovskite devices are calculated 0.39% and 0.96% respectively, which establish Al-perovskite film as a useful component for future solar cell device manufacturing.

An assessment of gender sensitivity in a selection of transport surveys

CSIR Research Space (South Africa)

Mashiri, M

2006-12-01

Full Text Available at worst (Mashiri, 2001). The starting point for engendering transport data has generally been to gender-disaggregate figures and analyses in transport surveys (ibid). Gender differences in time spent on travel and transport, as well as socio...-economic and health costs relating to transport, have thus far primarily been highlighted in gender-disaggregated quantitative transport data (Venter et al, 2006). Gender- disaggregated travel time data has, in particular, raised awareness of women’s significant...

Physiological responses of food animals to road transportation stress

African Journals Online (AJOL)

STORAGESEVER

2009-12-29

Dec 29, 2009 ... transportation are numerous and the responses of the animal to them are complex, non-specific and ..... at 3 h after a 6 h journey in male Japanese goats. During ..... animals are subjected to concomitant action of transport- tation and heat stress .... those measured in moving vehicles (Warriss et al., 1993).

Polymer solar cells with efficiency >10% enabled via a facile solution-processed Al-doped ZnO electron transporting layer

KAUST Repository

Jagadamma, Lethy Krishnan

2015-10-05

The present work details a facile and low-temperature (125C) solution-processed Al-doped ZnO (AZO) buffer layer functioning very effectively as electron accepting/hole blocking layer for a wide range of polymer:fullerene bulk heterojunction systems, and yielding power conversion efficiency in excess of 10% (8%) on glass (plastic) substrates. We show that ammonia addition to the aqueous AZO nanoparticle solution is a critically important step toward producing compact and smooth thin films which partially retain the aluminum doping and crystalline order of the starting AZO nanocrystals. The ammonia treatment appears to reduce the native defects via nitrogen incorporation, making the AZO film a very good electron transporter and energetically matched with the fullerene acceptor. Importantly, highly efficient solar cells are achieved without the need for additional surface chemical passivation or modification, which has become an increasingly common route to improving the performance of evaporated or solution-processed ZnO ETLs in solar cells.

A Comparison of Analytical and Numerical Methods for Modeling Dissolution and Other Reactions in Transport Limited Systems

Science.gov (United States)

Hochstetler, D. L.; Kitanidis, P. K.

2009-12-01

Modeling the transport of reactive species is a computationally demanding problem, especially in complex subsurface media, where it is crucial to improve understanding of geochemical processes and the fate of groundwater contaminants. In most of these systems, reactions are inherently fast and actual rates of transformations are limited by the slower physical transport mechanisms. There have been efforts to reformulate multi-component reactive transport problems into systems that are simpler and less demanding to solve. These reformulations include defining conservative species and decoupling of reactive transport equations so that fewer of them must be solved, leaving mostly conservative equations for transport [e.g., De Simoni et al., 2005; De Simoni et al., 2007; Kräutle and Knabner, 2007; Molins et al., 2004]. Complex and computationally cumbersome numerical codes used to solve such problems have also caused De Simoni et al. [2005] to develop more manageable analytical solutions. Furthermore, this work evaluates reaction rates and has reaffirmed that the mixing rate,▽TuD▽u, where u is a solute concentration and D is the dispersion tensor, as defined by Kitanidis [1994], is an important and sometimes dominant factor in determining reaction rates. Thus, mixing of solutions is often reaction-limiting. We will present results from analytical and computational modeling of multi-component reactive-transport problems. The results have applications to dissolution of solid boundaries (e.g., calcite), dissolution of non-aqueous phase liquids (NAPLs) in separate phases, and mixing of saltwater and freshwater (e.g. saltwater intrusion in coastal carbonate aquifers). We quantify reaction rates, compare numerical and analytical results, and analyze under what circumstances which approach is most effective for a given problem. References: DeSimoni, M., et al. (2005), A procedure for the solution of multicomponent reactive transport problems, Water Resources Research, 41

Structural, magnetic and transport properties of Co{sub 2}FeAl Heusler films with varying thickness

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaotian [School of Material Sciences and Engineering, Hebei University Technology, Tianjin 300130 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Yueqing [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Metastable Material Sciences and Technology, Yanshan University, Qinhuangdao 066004 (China); Du, Yin [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Dai, Xuefang; Liu, Guodong [School of Material Sciences and Engineering, Hebei University Technology, Tianjin 300130 (China); Liu, Enke [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhongyuan [State Key Laboratory of Metastable Material Sciences and Technology, Yanshan University, Qinhuangdao 066004 (China); Wang, Wenhong, E-mail: wenhong.wang@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Guangheng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-08-01

We report on a systematic study of the structural, magnetic properties and the anomalous Hall effect, in the Heusler alloy Co{sub 2}FeAl (CFA) epitaxial films on MgO (001), as a function of film thickness. It was found that the epitaxial CFA films show a highly ordered B2 structure with an in-plane uniaxial magnetic anisotropy. The electrical transport properties reveal that the lattice and magnon scattering contributions to the longitudinal resistivity. Independent on the thickness of films, the anomalous Hall resistivity of CFA films is found to be dominated by skew scattering only. Moreover, the anomalous Hall resistivity shows weakly temperature dependent behavior, and its absolute value increases as the thickness decreases. We attribute this temperature insensitivity in the anomalous Hall resistivity to the weak temperature dependent of tunneling spin-polarization in the CFA films, while the thickness dependence behavior is likely due to the increasing significance of interface or free surface electronic states. - Highlights: ●Highly ordered CFA films with various thicknesses were prepared on MgO substrates. ●The magnon scattering contributions to the longitudinal resistivity in the CFA films. ●The anomalous Hall resistivity of the CFA films shows weakly temperature dependent. ●The CFA films show weak temperature dependent of tunneling spin-polarization.

Sucrose assimilation and the role of sucrose transporters in plant ...

African Journals Online (AJOL)

STORAGESEVER

2008-12-29

Dec 29, 2008 ... African Journal of Biotechnology Vol. 7 (25), pp. ... Review. Sucrose assimilation and the role of sucrose transporters in plant wound response. Omodele ... Key words: Sucrose transporters, Plasma membrane, carbohydrate, sieve element, source-sink. ... pathogens (Paul et al., 2000) and results in a severe.

MUTC-un modelo de transporte de rios : aplicación al Rio Sinú

OpenAIRE

Jiménez Jaramillo, Mario Alberto

2008-01-01

Se propone un Modelo Unidimensional de Transporte de Contaminantes MUTC que se fundamenta en la aproximación numérica de la clásica ecuación de transporte Advección-Dispersión-Reacción, la cual se acopla con un modelo de tránsito de caudales que permite inferir los parámetros hidráulicos que gobiernan el transporte advectivo y difusivo de solutos introducidos en una corriente. Las reacciones químicas consideradas han sido priorizadas de acuerdo con el marco juridico y ambiental actualmente...

Anisotropic electrical, thermal and magnetic properties of Al{sub 13}Ru{sub 4} decagonal quasicrystalline approximant

Energy Technology Data Exchange (ETDEWEB)

Wencka, Magdalena [Polish Academy of Sciences, Poznan (Poland). Inst. of Molecular Physics; Vrtnik, Stanislav; Kozelj, Primoz; Dolinsek, Janez [Ljubljana Univ. (Slovenia). Faculty of Mathematics and Physics; Jozef Stefan Institute, Ljubljana (Slovenia); Jaglicic, Zvonko [Ljubljana Univ. (Slovenia). Inst. of Mathematics, Physics and Mechanics; Gille, Peter [Muenchen Univ. (Germany). Crystallography Section

2017-09-01

We present measurements of the anisotropic electrical and thermal transport coefficients (the electrical resistivity, the thermoelectric power, the thermal conductivity), the magnetization and the specific heat of the Al{sub 13}Ru{sub 4} monoclinic approximant to the decagonal quasicrystal, in comparison to the isostructural Al{sub 13}Fe{sub 4}. The electrical and thermal transport parameters of Al{sub 13}Ru{sub 4} were found to exhibit significant anisotropy, qualitatively similar to that found previously in the Al{sub 13}Fe{sub 4} (P. Popcevic, et al., Phys. Rev. B 2010, 81, 184203). The crystallographic b direction, corresponding to the stacking direction of the (a,c) atomic planes, is the most conducting direction for the electricity and heat. The thermopower is strongly anisotropic with a complicated temperature dependence, exhibiting maxima, minima, crossovers and sign change. The electronic density of states (DOS) at the Fermi energy is reduced to 35% of the DOS of Al metal. The magnetic susceptibility is diamagnetic and the diamagnetism is by a factor of 2 stronger for the magnetic field along the stacking b direction.

Simulation of electron thermal transport in H-mode discharges

International Nuclear Information System (INIS)

Rafiq, T.; Pankin, A. Y.; Bateman, G.; Kritz, A. H.; Halpern, F. D.

2009-01-01

Electron thermal transport in DIII-D H-mode tokamak plasmas [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] is investigated by comparing predictive simulation results for the evolution of electron temperature profiles with experimental data. The comparison includes the entire profile from the magnetic axis to the bottom of the pedestal. In the simulations, carried out using the automated system for transport analysis (ASTRA) integrated modeling code, different combinations of electron thermal transport models are considered. The combinations include models for electron temperature gradient (ETG) anomalous transport and trapped electron mode (TEM) anomalous transport, as well as a model for paleoclassical transport [J. D. Callen, Nucl. Fusion 45, 1120 (2005)]. It is found that the electromagnetic limit of the Horton ETG model [W. Horton et al., Phys. Fluids 31, 2971 (1988)] provides an important contribution near the magnetic axis, which is a region where the ETG mode in the GLF23 model [R. E. Waltz et al., Phys. Plasmas 4, 2482 (1997)] is below threshold. In simulations of DIII-D discharges, the observed shape of the H-mode edge pedestal is produced when transport associated with the TEM component of the GLF23 model is suppressed and transport given by the paleoclassical model is included. In a study involving 15 DIII-D H-mode discharges, it is found that with a particular combination of electron thermal transport models, the average rms deviation of the predicted electron temperature profile from the experimental profile is reduced to 9% and the offset to -4%.

Desafíos del Sector Transporte

OpenAIRE

Sociedad Chilena de Ingeniería de Transporte

2013-01-01

La Sociedad Chilena de Ingeniería de Transporte (Sochitran), entregó el documento "Desafíos del Sector Transporte" para la discusión pública, como un aporte de esa Institución al debate programático presidencial que se llevó a cabo en Chile en ocasión de las elecciones presidenciales que han de llevar a La Moneda el próximo Presidente de la Nación en el período 2014-2018.

Atomic carbon chains as spin-transmitters: An ab initio transport study

DEFF Research Database (Denmark)

Fürst, Joachim Alexander; Brandbyge, Mads; Jauho, Antti-Pekka

2010-01-01

An atomic carbon chain joining two graphene flakes was recently realized in a ground-breaking experiment by Jin et al. (Phys. Rev. Lett., 102 (2009) 205501). We present ab initio results for the electron transport properties of such chains and demonstrate complete spin-polarization of the transmi......An atomic carbon chain joining two graphene flakes was recently realized in a ground-breaking experiment by Jin et al. (Phys. Rev. Lett., 102 (2009) 205501). We present ab initio results for the electron transport properties of such chains and demonstrate complete spin...

Farmacogenética aplicada al tratamiento de la leucemia linfoide aguda Pharmacogenetics applied to the treatment of acute lymphoid leukemia

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Yalena Prado Vizcaíno

2011-09-01

Full Text Available Las enzimas de biotransformación y eliminación de los fármacos en pacientes con leucemia linfoide aguda tienen una acción determinante en el efecto terapéutico de los medicamentos antineoplásicos. La presencia y actividad de estos complejos enzimáticos está codificada genéticamente y sujeta a variaciones alélicas, cuyas frecuencias son variables en las diferentes poblaciones humanas. Este polimorfismo genético influye sobre la efectividad terapéutica de los medicamentos y condiciona la carencia de toxicidad o presencia de esta, que en ocasiones puede ser fatal. Las enzimas tiopurin-metil-transferasa, metilén-tetrahidrofolato-reductasa y glutatión-tranferasa son sistemas destoxificadores de algunos de los quimioterápicos empleados en el tratamiento de la leucemia linfoide aguda. En este trabajo se revisan las características genéticas de estas enzimas, la frecuencia de sus polimorfismos y las implicaciones clínicas de su expresión. De igual modo se discute la importancia y los beneficios del genotipaje previo al inicio del tratamiento, con el fin de modificar las dosis de los medicamentos para optimizar su efecto terapéutico y disminuir su toxicidad. La farmacogenética constituye un área de creciente interés que ha tenido un desarrollo considerable en los últimos años, su conocimiento e implementación nos colocará en el camino de la medicina personalizada.The biotransformation and elimination enzymes of drugs in patients suffering from acute lymphoid leukemia play a decisive role on the therapeutical effect of anti-neoplastic drugs. The presence and activity of these enzymatic complexes are genetically coded and subjected to allele variations, the frequency of which is variable in the different human populations. This genetic polymorphism has an impact on the therapeutic effectiveness of drugs and determines the lack or the existence of toxicity that may sometimes become lethal. The enzymes called thiopurine

Fuzzy linear programming approach for solving transportation ...

Indian Academy of Sciences (India)

ALI EBRAHIMNEJAD

Department of Mathematics, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran e-mail: ..... est grade of membership at x are μ ˜AL (x) and μ ˜AU (x), respectively. ..... trapezoidal fuzzy numbers transportation problem (12) are.

Produção e qualidade de rosas em razão de doses de boro aplicadas no substrato

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Luiz Antônio Zanão Júnior

2014-04-01

Full Text Available Muitos trabalhos têm demonstrado os efeitos da aplicação do boro (B em variadas culturas; entretanto, poucos registros demonstram seus efeitos na produção de rosas. Objetivou-se com este experimento avaliar os efeitos de doses de B na produção e qualidade de rosas (Rosa hybrida cv. Shiny Terrazza® em vaso. Os tratamentos foram cinco doses de B (0, 1, 4, 8 e 16 mg kg-1, aplicadas no substrato, em delineamento de blocos casualizados, com cinco repetições. Foram avaliados: número de flores por planta; número de folhas por haste floral; produção de matéria seca de raízes, folhas e flores; altura da planta; número de dias para o florescimento; comprimento do botão floral; e diâmetro e longevidade floral. Além disso, foram determinados os teores foliares de clorofila total e B e os sintomas de toxidez desse elemento. Verificou-se efeito significativo das doses de B na maioria das variáveis avaliadas, excetuando-se a altura das plantas, o número de flores por planta, a longevidade floral e a produção de matéria seca de raízes. O teor foliar de B aumentou linearmente em função das doses desse elemento. Houve incremento na produção e qualidade das flores com a aplicação do B, com redução do número de dias para o florescimento. Foram verificados sintomas de toxidez causado pelo B a partir da dose de 4 mg kg-1. Esses sintomas foram caracterizados por manchas do tipo encharcamento, iniciando nas margens do limbo foliar, com essas evoluindo para clorose e posterior necrose; na maior dose ocorreu queda de folhas. Essa queda foi responsável pela diminuição do número de folhas por haste no final do ciclo, a partir da dose de 8 mg kg-1 de B. As plantas com sintomas de toxidez apresentaram teores foliares de B acima de 200 mg kg-1, enquanto as sadias (controle, de 65 a 89 mg kg-1.

Aproximación territorial a los intercambiadores de transporte

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Sonia Esperanza Díaz

2011-03-01

Full Text Available En la búsqueda por entender la relación entre el transporte y el territorio existen numerosos estudios que han realizado diferentes aproximaciones al tema, especialmente desde la teoría de la “interacción transporte-uso del suelo”, los cuales tratan de dilucidar cómo las infraestructuras potencian ciertos procesos de localización de actividades (residenciales, industriales, comerciales y otros servicios, contribuyen a la determinación de la estructura del territorio e inciden en las dinámicas económicas y sociales, principalmente. Este artículo presenta una revisión de los principales elementos de los intercambiadores, como infraestructura de transporte de tipo puntual (definición, servicios que ofrece y estructura física, y de la forma como ha sido estudiada su incidencia en el territorio al que se incardinan.

Acceso al transporte público para personas con discapacidad en Bogotá: caso SITP

OpenAIRE

Carreño Ordóñez, Álvaro Fabián

2015-01-01

U na de la s formas de acceder a los bienes y servicios sociales en las ciudades es por medio del transporte público . Este trabajo realiza el aná lisis del Sistema Integrado de Transporte Público de Bogotá – SITP -­‐ con respecto ...

Model Comparison for Electron Thermal Transport

Science.gov (United States)

Moses, Gregory; Chenhall, Jeffrey; Cao, Duc; Delettrez, Jacques

2015-11-01

Four electron thermal transport models are compared for their ability to accurately and efficiently model non-local behavior in ICF simulations. Goncharov's transport model has accurately predicted shock timing in implosion simulations but is computationally slow and limited to 1D. The iSNB (implicit Schurtz Nicolai Busquet electron thermal transport method of Cao et al. uses multigroup diffusion to speed up the calculation. Chenhall has expanded upon the iSNB diffusion model to a higher order simplified P3 approximation and a Monte Carlo transport model, to bridge the gap between the iSNB and Goncharov models while maintaining computational efficiency. Comparisons of the above models for several test problems will be presented. This work was supported by Sandia National Laboratory - Albuquerque and the University of Rochester Laboratory for Laser Energetics.

INFORMATION SYSTEMS APPLIED TO TRANSPORT IMPROVEMENT

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JULIAN ANDRES ZAPATA CORTES

2013-01-01

Full Text Available El transporte es uno de los elementos más relevantes para la competitividad de las empresas y las ciudades, pues un sistema de transporte inadecuado genera altos costos y bajos niveles de servicio al cliente, lo que fi nalmente produce un impacto económico para ambas partes. Este artículo presenta una revisión de herramientas tecnológicas que hacen parte de los sistemas de transporte inteligentes (ITS, sistemas utilizados para el mejoramiento del desempeño y seguridad del transporte, no solo de carga sino también de pasajeros y en diferentes modos. El artículo comienza con una descripción sobre los sistemas de transporte ITS, seguido por la presentación de los benefi cios de estos sistemas y fi nalmente se realiza una revisión de las diferentes herramientas que enmarcan los ITS.

UFD Storage and Transportation - Transportation Working Group Report

International Nuclear Information System (INIS)

Maheras, Steven J.; Ross, Steven B.

2011-01-01

The Used Fuel Disposition (UFD) Transportation Task commenced in October 2010. As its first task, Pacific Northwest National Laboratory (PNNL) compiled a list of structures, systems, and components (SSCs) of transportation systems and their possible degradation mechanisms during extended storage. The list of SSCs and the associated degradation mechanisms (known as features, events, and processes (FEPs)) were based on the list of used nuclear fuel (UNF) storage system SSCs and degradation mechanisms developed by the UFD Storage Task (Hanson et al. 2011). Other sources of information surveyed to develop the list of SSCs and their degradation mechanisms included references such as Evaluation of the Technical Basis for Extended Dry Storage and Transportation of Used Nuclear Fuel (NWTRB 2010), Transportation, Aging and Disposal Canister System Performance Specification, Revision 1 (OCRWM 2008), Data Needs for Long-Term Storage of LWR Fuel (EPRI 1998), Technical Bases for Extended Dry Storage of Spent Nuclear Fuel (EPRI 2002), Used Fuel and High-Level Radioactive Waste Extended Storage Collaboration Program (EPRI 2010a), Industry Spent Fuel Storage Handbook (EPRI 2010b), and Transportation of Commercial Spent Nuclear Fuel, Issues Resolution (EPRI 2010c). SSCs include items such as the fuel, cladding, fuel baskets, neutron poisons, metal canisters, etc. Potential degradation mechanisms (FEPs) included mechanical, thermal, radiation and chemical stressors, such as fuel fragmentation, embrittlement of cladding by hydrogen, oxidation of cladding, metal fatigue, corrosion, etc. These degradation mechanisms are discussed in Section 2 of this report. The degradation mechanisms have been evaluated to determine if they would be influenced by extended storage or high burnup, the need for additional data, and their importance to transportation. These categories were used to identify the most significant transportation degradation mechanisms. As expected, for the most part, the

Otimização dos parâmetros operacionais de eletrocoagulação aplicada à recuperação de efluentes de lavagem de veículos

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Angelita Aparecida Ribeiro da Silva

Full Text Available RESUMO No Brasil, cerca de 32.700 postos de lavagem de veículos consomem 3,7 milhões de m3/mês-1, média de 60 L por veículo. Esse consumo poderia ser minimizado, se o efluente fosse devidamente tratado e reutilizado. Como diversos tipos de efluentes têm sido eficientemente tratados por técnicas eletroquímicas, como a eletrocoagulação (EC e a eletroflotação (EF, o objetivo principal deste estudo foi desenvolver um sistema de tratamento de efluentes de lavagem de carros por EC, usando eletrodos de alumínio. Parâmetros como pH inicial, corrente elétrica aplicada e tempo de eletrólise foram otimizados por meio de análises físico-químicas e estatísticas. Em sua condição ótima, pH 5, corrente elétrica de 3,5 A e tempo de 20 minutos, o sistema conseguiu reduzir em 73% a demanda química de oxigênio (DQO, 58% de surfactantes e no mínimo 90% a turbidez e os sólidos suspensos totais (SST. Além da simples implantação e operação, a técnica mostrou-se eficiente na recuperação desse tipo de efluente, podendo ser utilizada em sistemas de reúso de água de lavagem de veículos.

Riluzole increases the rate of glucose transport in L6 myotubes and NSC-34 motor neuron-like cells via AMPK pathway activation.

Science.gov (United States)

Daniel, Bareket; Green, Omer; Viskind, Olga; Gruzman, Arie

2013-09-01

Riluzole is the only approved ALS drug. Riluzole influences several cellular pathways, but its exact mechanism of action remains unclear. Our goal was to study the drug's influence on the glucose transport rate in two ALS relevant cell types, neurons and myotubes. Stably transfected wild-type or mutant G93A human SOD1 NSC-34 motor neuron-like cells and rat L6 myotubes were exposed to riluzole. The rate of glucose uptake, translocation of glucose transporters to the cell's plasma membrane and the main glucose transport regulatory proteins' phosphorylation levels were measured. We found that riluzole increases the glucose transport rate and up-regulates the translocation of glucose transporters to plasma membrane in both types of cells. Riluzole leads to AMPK phosphorylation and to the phosphorylation of its downstream target, AS-160. In conclusion, increasing the glucose transport rate in ALS affected cells might be one of the mechanisms of riluzole's therapeutic effect. These findings can be used to rationally design and synthesize novel anti-ALS drugs that modulate glucose transport in neurons and skeletal muscles.

Integro-differential transport approaches

International Nuclear Information System (INIS)

Stepanek, J.; Arkuszewski, J.; Boffi, V.; Matausek, M.V.

1981-01-01

This chapter summarizes the work done in Italy, Poland, Switzerland and Yugoslavia in the field of integro-differential neutron transport theory. It reflects different viewpoints in the handling of the subject. Some of the methods are based only on the solution of the integro-differential equation, others use only the integral form of the transport equation. Use of the characteristic solution closely related to the integral equation (ARKUSZEWSKI et al.,(1979)) seems to be a rather effective way to accelerate the 2 dimensional discrete ordinates (Ssub(n)) transport methods and supress one of the main disadvantages, the ray effect. The advanced ''Surface Currents'' (MAEDER (1975)) and ''Surface Flux'' (STEPANEK (1979)) methods are based on the solution of both the integro-differential and integral form of the transport equation. As long as the spatial fluxes were considered to be flat in each region only the integral form of the transport equation was considered. The solution seems to be the best method of simple handling the higher order Legendre polynomials used to approximate spatial and angular flux distribution. The coupling of the Bsub(n) integral transport equations with the related Psub(n) equations removes the greatest disadvantage of the Psub(n) theory and closes the system of the Psub(n) equations (LIGOU, STEPANEK (1974))

Tunneling current via dislocations in Schottky diodes on AlInN/AlN/GaN heterostructures

International Nuclear Information System (INIS)

Arslan, Engin; Ozbay, Ekmel; Altındal, Şemsettin; Özçelik, Süleyman

2009-01-01

The forward current–voltage–temperature characteristics of (Ni/Au)–Al 0.83 In 0.17 N/AlN/GaN heterostructures were studied in a temperature range of 80–375 K. The temperature dependences of the tunneling saturation current (I t ) and tunneling parameters (E 0 ) were obtained. Weak temperature dependence of the saturation current and the absence of temperature dependence of the tunneling parameters were observed in this temperature range. The results indicate that in the temperature range of 80–375 K, the mechanism of charge transport in the (Ni/Au)–Al 0.83 In 0.17 N/AlN/GaN heterostructure is performed by tunneling among dislocations intersecting the space-charge region. A model is used for nonuniform tunneling along these dislocations that intersect the space-charge region. The dislocation density that was calculated from the current–voltage characteristics, according to a model of tunneling along the dislocation line, gives the value 7.4 × 10 8 cm −2 . This value is close in magnitude to the dislocation density that was obtained from the x-ray diffraction measurements value of 5.9 × 10 8 cm −2 . These data show that the current flows manifest a tunneling character, even at room temperature

Biomecánica aplicada al diseño de una Herramienta de Evaluación de los saltos en Gimnasia Rítmica atendiendo al Código Internacional de Puntuación. Aplicación a la evaluación del salto zancada

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Ignacio Grande Rodríguez

2008-09-01

Full Text Available La Biomecánica ha realizado estudios sobre los saltos en Gimnasia Rítmica desde el punto de vista cinemático (Lebré y Sousa, 1997; Sousa y Lebré, 1998 y dinámico (Ferro, Rivera y Pagola, 2000. Sin embargo no tenemos constancia de ningún estudio que los valore atendiendo a los requerimientos específicos del vigente Código de Puntuación. Éstos requerimientos son tres Características de Base que deben cumplir los saltos: altura, forma y amplitud (FIG, 2005. El objetivo principal de este Proyecto es crear una herramienta para evaluar los saltos de Gimnasia Rítmica incluyendo tanto variables cinemáticas generales, variables de uso extensivo en el análisis de este tipo de movimientos desde el punto de vista de la biomecánica, como variables cinemáticas específicas, traduciendo las Características de Base que son juzgadas en competición a variables cinemáticas cuantificables. Para realizar la evaluación de los saltos nos apoyándonos en análisis cinemáticos realizados mediante videogrametría 3D. Tras varios diseños se presenta la Ficha de Evaluación del salto zancada que ha sido ya aplicada en un grupo de gimnastas de alto nivel (n=19. Las principales novedades de esta propuesta son el diseño de una herramienta de evaluación específica para este tipo de elementos técnicos teniendo en cuenta la normativa concreta de la Gimnasia Rítmica, la valoración objetiva de las características de base del salto y el intento de presentar los resultados biomecánicos de una forma entendible y rápidamente asimilable para el entrenador.

Frecuencia de los hongos asociados al desarrollo de mohos poscosecha en el pedúnculo de la piña en dos zonas de Costa Rica

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Johanny Castro Chinchilla

2017-01-01

Full Text Available La piña es uno de los principales cultivos de exportación en Costa Rica y la presencia de moho en el pedúnculo afecta su calidad en los mercados internacionales. El objetivo de esta investigación fue determinar en frutos de piña, en la cera aplicada sobre la fruta y en el aire de las cámaras de enfriamiento, la frecuencia de los principales hongos asociados al desarrollo de mohos en el pedúnculo. Se realizó un muestreo mensual de abril de 2012 a marzo de 2013 en empacadoras de Sarapiquí y Puntarenas, Costa Rica. En cada empacadora se muestreó: frutos luego del proceso-comercial que se realiza para exportación y almacenamiento, la cera aplicada sobre la superficie de las frutas y el aire de las cámaras de enfriamiento. Se realizó un análisis de frecuencia de los principales hongos recuperados por muestreo en cada zona, para la cáscara y el pedúnculo, la cera y el aire. Además, se comparó el crecimiento in vitro a 18°C de los hongos más frecuentes al finalizar los muestreos. El hongo más frecuente en las cámaras de enfriamiento, el pedúnculo y la cáscara de ambas zonas y en la cera de Sarapiquí fue Penicillium diversum, con valores entre 7% y 100%. Mientras que en la cera de Puntarenas únicamente destacó la presencia de un grupo de hongos de micelio blanco. P. purpureogenum, Penicillium sp., Talaromyces calidicanius y Cladosporium sp., fueron microorganismos también recuperados con alta frecuencia tanto en la fruta como en el aire de las cámaras de enfriamiento de ambas empacadoras. P. purpureogenum, P. diversum y T. calidicanius fueron las especies con mayor crecimiento in vitro. Se concluyó que el manejo integrado de P. diversum, P. purpureogenum y T. calidicanius es necesario si se desea evitar el desarrollo de moho en el pedúnculo de la piña.

Tecnoparque SENA : Una apuesta biotecnológica al alcance de todos

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María Isabel Gaviria

2013-01-01

Full Text Available A nivel mundial se considera que la biotecnología y la nanotecnología son ejes centrales para la  solución  de  grandes problemas de la humanidad como el cambio climático, la cura de enfermedades, la generación de energías alternativas y la emergencia alimentaria[1]. En el mercado nacional, la biotecnología se plantea como sector estratégico dentro de las locomotoras de innovación y estrategia transversal para dar valor agregado a sectores de talla mundial[2]. En este contexto, el programa de innovación SENA denominado “Red Tecnoparque” ofrece al país asesoría técnica especializada y acceso gratuito a infraestructura de punta en 4 áreas del conocimiento incluyendo la línea de biotecnología y nanotecnología. Particularmente, en Tecnoparque nodo Medellín esta línea  viene impulsando desde el año 2010 el desarrollo de proyectos productivos basados en conocimiento, trabajando de la mano de las más importantes y reconocidas instituciones acádemicas en áreas estratégicas como nanotecnología aplicada a nuevos materiales y formulación de alimentos funcionales basados en probióticos. [1](Shumpeter, 2012 [2](The Bioeconomy to 2030 - Designing a policy agenda, 2009

La investigación en pedagogía y didáctica aplicada a la educación física A pesquisa em pedagogia e didática aplicada à educação física Research on Teaching and Didactics Applied to Physical Education

Directory of Open Access Journals (Sweden)

Julia Adriana Castro-Carvajal

2012-12-01

Full Text Available Este texto forma parte de un proyecto de investigación que busca elaborar un estado del arte sobre investigación educativa en educación física, recreación y deporte en Antioquia entre 1998-2009. Este artículo analiza la producción de conocimiento sobre pedagogía y didáctica aplicada en los campos mencionados. Se trata de dar cuenta de aquello que atañe a las concepciones y los modelos pedagógicos y a los enfoques didácticos hallados en las investigaciones educativas revisadas. Los resultados reflejan la coexistencia de una multiplicidad de enfoques teórico-metodológicos desamparados de un debate pedagógico que, a su vez, reflejan un vacío científico en la comunidad académica.Este texto faz parte de um projeto de pesquisa que pretende elaborar um estado da arte sobre pesquisa educativa em educação física, recreação e esporte em Antioquia entre 1998-2009. Este artigo analisa a produção de conhecimento sobre pedagogia e didática aplicada nos campos mencionados. Trata-se de dar conta daquilo que se refere às concepções, aos modelos pedagógicos e aos enfoques didáticos encontrados nas pesquisas educativas revisadas. Os resultados refletem a coexistência de uma multiplicidade de enfoques teórico-metodológicos desamparados de um debate pedagógico que, por sua vez, refletem um vazio científico na comunidade acadêmica.This article is part of a research project designed to compile information on the state of the art in educational research on physical education, recreation and sports in Antioquia between 1998 and 2009. Specifically, it analyzes the production of knowledge on teaching and didactics applied to the aforementioned fields and, in that respect, it attempts to identify what concerns the pedagogic concepts and models, and the didactic approaches found in the educational research reviewed for the study. The findings point to the coexistence of a wealth of theoretical and methodological approaches bereft of

Computational Study of Anomalous Transport in High Beta DIII-D Discharges with ITBs

Science.gov (United States)

Pankin, Alexei; Garofalo, Andrea; Grierson, Brian; Kritz, Arnold; Rafiq, Tariq

2015-11-01

The advanced tokamak scenarios require a large bootstrap current fraction and high β. These large values are often outside the range that occurs in ``conventional'' tokamak discharges. The GLF23, TGLF, and MMM transport models have been previously validated for discharges with parameters associated with ``conventional'' tokamak discharges. It has been demonstrated that the TGLF model under-predicts anomalous transport in high β DIII-D discharges [A.M. Garofalo et al. 2015 TTF Workshop]. In this research, the validity of MMM7.1 model [T. Rafiq et al. Phys. Plasmas 20 032506 (2013)] is tested for high β DIII-D discharges with low and high torque. In addition, the sensitivity of the anomalous transport to β is examined. It is shown that the MMM7.1 model over-predicts the anomalous transport in the DIII-D discharge 154406. In particular, a significant level of anomalous transport is found just outside the internal transport barrier. Differences in the anomalous transport predicted using TGLF and MMM7.1 are reviewed. Mechanisms for quenching of anomalous transport in the ITB regions of high-beta discharges are investigated. This research is supported by US Department of Energy.

Inteligência artificial aplicada à Zootecnia Artificial intelligence in Animal Science

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Ernane José Xavier Costa

2009-07-01

Full Text Available Os sistemas biológicos são surpreendentemente flexíveis pra processar informação proveniente do mundo real. Alguns organismos biológicos possuem uma unidade central de processamento denominada de cérebro. O cérebro humano consiste de 10(11 neurônios e realiza processamento inteligente de forma exata e subjetiva. A Inteligência Artificial (IA tenta trazer para o mundo da computação digital a heurística dos sistemas biológicos de várias maneiras, mas, ainda resta muito para que isso seja concretizado. No entanto, algumas técnicas como Redes neurais artificiais e lógica fuzzy tem mostrado efetivas para resolver problemas complexos usando a heurística dos sistemas biológicos. Recentemente o numero de aplicação dos métodos da IA em sistemas zootécnicos tem aumentado significativamente. O objetivo deste artigo é explicar os princípios básicos da resolução de problemas usando heurística e demonstrar como a IA pode ser aplicada para construir um sistema especialista para resolver problemas na área de zootecnia.Biological systems are surprising flexible in processing information in the real world. Some biological organisms have a central unit processing named brain. The human's brain, consisting of 10(11 neurons, realizes intelligent information processing based on exact and commonsense reasoning. Artificial intelligence (AI has been trying to implement biological intelligence in computers in various ways, but is still far from real one. Therefore, there are approaches like Symbolic AI, Artificial Neural Network and Fuzzy system that partially successful in implementing heuristic from biological intelligence. Many recent applications of these approaches show an increased interest in animal science research. The main goal of this article is to explain the principles of heuristic problem-solving approach and to demonstrate how they can be applied to building knowledge-based systems for animal science problem solving.

Diseño de una estrategia que posicione a Transporte Comercial la Estrella SAS como una empresa mas competitiva en el sector transporte

OpenAIRE

Cifuentes Amaya, Mauricio Andrés

2017-01-01

La elaboración de este proyecto busca explicar los factores que actualmente afectan al sector transporte (Costos elevados, sobreoferta, chatarrización, fletes elevados, hacinamiento, Etc.) y, a partir de esto, diseñar estrategias que le permitan a la empresa de transporte: TRANSPORTE COMERCIAL LA ESTRELLA SAS, convertirse en una empresa más competitiva dentro del sector en el que se desenvuelve. El planteamiento estratégico estudiado se fundamenta en el modelo de las 5 fuerzas de Michael P...

Nonvolatile Resistive Switching in Pt/LaAlO_{3}/SrTiO_{3} Heterostructures

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Shuxiang Wu

2013-12-01

Full Text Available Resistive switching heterojunctions, which are promising for nonvolatile memory applications, usually share a capacitorlike metal-oxide-metal configuration. Here, we report on the nonvolatile resistive switching in Pt/LaAlO_{3}/SrTiO_{3} heterostructures, where the conducting layer near the LaAlO_{3}/SrTiO_{3} interface serves as the “unconventional” bottom electrode although both oxides are band insulators. Interestingly, the switching between low-resistance and high-resistance states is accompanied by reversible transitions between tunneling and Ohmic characteristics in the current transport perpendicular to the planes of the heterojunctions. We propose that the observed resistive switching is likely caused by the electric-field-induced drift of charged oxygen vacancies across the LaAlO_{3}/SrTiO_{3} interface and the creation of defect-induced gap states within the ultrathin LaAlO_{3} layer. These metal-oxide-oxide heterojunctions with atomically smooth interfaces and defect-controlled transport provide a platform for the development of nonvolatile oxide nanoelectronics that integrate logic and memory devices.

Aproximación territorial a los intercambiadores de transporte

Directory of Open Access Journals (Sweden)

Sonia Esperanza Díaz

2011-11-01

Full Text Available En la búsqueda por entender la relación entre el transporte y el territorio existen numerosos estudios que han realizado diferentes aproximaciones al tema, especialmente desde la teoría de la “interacción transporte-uso del suelo”, los cuales tratan de dilucidar cómo las infraestructuras potencian ciertos procesos de localización de actividades (residenciales, industriales, comerciales y otros servicios, contribuyen a la determinación de la estructura del territorio e inciden en las dinámicas económicas y sociales, principalmente. Este artículo presenta una revisión de los principales elementos de los intercambiadores, como infraestructura de transporte de tipo puntual (definición, servicios que ofrece y estructura física, y de la forma como ha sido estudiada su incidencia en el territorio al que se incardinan.

Failure to Deliver and Translate-New Insights into RNA Dysregulation in ALS.

Science.gov (United States)

Coyne, Alyssa N; Zaepfel, Benjamin L; Zarnescu, Daniela C

2017-01-01

Amyotrophic Lateral Sclerosis (ALS) is a progressive and fatal neurodegenerative disease affecting both upper and lower motor neurons. The molecular mechanisms underlying disease pathogenesis remain largely unknown. Multiple genetic loci including genes involved in proteostasis and ribostasis have been linked to ALS providing key insights into the molecular mechanisms underlying disease. In particular, the identification of the RNA binding proteins TDP-43 and fused in sarcoma (FUS) as causative factors of ALS resulted in a paradigm shift centered on the study of RNA dysregulation as a major mechanism of disease. With wild-type TDP-43 pathology being found in ~97% of ALS cases and the identification of disease causing mutations within its sequence, TDP-43 has emerged as a prominent player in ALS. More recently, studies of the newly discovered C9orf72 repeat expansion are lending further support to the notion of defects in RNA metabolism as a key factor underlying ALS. RNA binding proteins are involved in all aspects of RNA metabolism ranging from splicing, transcription, transport, storage into RNA/protein granules, and translation. How these processes are affected by disease-associated mutations is just beginning to be understood. Considerable work has gone into the identification of splicing and transcription defects resulting from mutations in RNA binding proteins associated with disease. More recently, defects in RNA transport and translation have been shown to be involved in the pathomechanism of ALS. A central hypothesis in the field is that disease causing mutations lead to the persistence of RNA/protein complexes known as stress granules. Under times of prolonged cellular stress these granules sequester specific mRNAs preventing them from translation, and are thought to evolve into pathological aggregates. Here we will review recent efforts directed at understanding how altered RNA metabolism contributes to ALS pathogenesis.

META-ANÁLISIS DE GENERALIZACIÓN DE LA FIABILIDAD DEL INVENTARIO DE OBSESIONES DE LEYTON VERSIÓN PARA NIÑOS AUTO-APLICADA

Directory of Open Access Journals (Sweden)

Julio Sánchez-Meca

2016-01-01

Full Text Available Fundamentos: El Inventario de Obsesiones de Leyton Versión para niños Auto-Aplicada (LOI-CV-SF es una escala ampliamente utilizada para la detección de síntomas obsesivo-compulsivos y su interferencia en la vida diaria en niños y adolescentes de 10 a 18 años. El objetivo fue estimar la fiabilidad de las puntuaciones del test y cómo varía en función de las características de los estudios. Método: Se realizó un metaanálisis. Una búsqueda exhaustiva permitió seleccionar 13 estudios que reportaron alguna estimación de la fiabilidad del test y, mediante la fórmula KR-21, se pudo incrementar esta base de datos hasta 43 estimaciones de la fiabilidad por consistencia interna. Tomando estos coeficientes se hizo una estimación media de la fiabilidad y un análisis de las variables que podían estar afectando a la heterogeneidad de los coeficientes de fiabilidad. Resultados: En promedio, la fiabilidad por consistencia interna de las puntuaciones del test para la escala de síntomas fue de 0,79 (IC al 95%: 0,76 y 0,82, con valores mínimo y máximo 0,52 y 0,97, respectivamente. Se observó una alta heterogeneidad (I2=96%. El modelo predictivo identificó la desviación típica de las puntuaciones del test como la variable más influyente. Conclusiones: Las puntuaciones del LOI-CV-SF presentan una fiabilidad media satisfactoria para propósitos de investigación, pero no para la práctica clínica. Los análisis de variables moderadoras revelaron, principalmente, que la desviación típica de las puntuaciones del test es la variable más relevante en la fiabilidad, presentando una correlación positiva con esta.

BIM, realidad aumentada y técnicas holográficas aplicadas a la construcción = BIM, increased reality and holographic techniques applied to construction

Directory of Open Access Journals (Sweden)

Jaime Santamarta Martínez

2018-05-01

Full Text Available La metodología BIM (Building Information Modelling, ampliamente implantada en el sector de la edificación y de la arquitectura, ha transformado la manera de desarrollar tanto los proyectos como las obras de construcción. Si bien la esencia de esta metodología se basa en la generación de un modelo tridimensional, la visualización de éste a través de dispositivos bidimensionales hace que la experiencia e interacción con el modelo no sea plena. Es por ello que la aparición en el mercado de nuevas tecnologías como la realidad virtual y la realidad aumentada, abren un amplio abanico de posibilidades ligadas al sector de la construcción. En este sentido, en Acciona Ingeniería se ha desarrollado un proyecto piloto en colaboración con Trimble y Microsoft donde a partir de un modelo BIM se ha creado una realidad aumentada basada en hologramas, que permitan recrear una simulación aplicada a la construcción Abstract The BIM (Building Information Modeling methodology, widely implemented in the building and architecture sector, has transformed the way to develop both projects and construction works. Although the essence of this methodology is based on the generation of a three-dimensional model, the visualization of it through two-dimensional devices means that the experience and interaction with the model is not complete. That is why the appearance in the market of new technologies such as virtual reality and augmented reality, open a wide range of possibilities linked to the construction sector. In this sense, Acciona Engineering has developed a pilot project in collaboration with Trimble and Microsoft where, based on a BIM model, an augmented reality based on holograms has been created, allowing to recreate a simulation applied to construction

Narrow nuclear resonance profiling of Al with subnanometric depth resolution

International Nuclear Information System (INIS)

Rosa, E.B.O. da; Krug, C.; Stedile, F.C.; Morais, J.; Baumvol, I.J.R.

2002-01-01

We report on the use of the narrow and isolated resonance at 404.9 keV in the cross-section curve of the 27 Al(p,γ) 28 Si nuclear reaction for profiling Al in ultrathin aluminum oxide films on Si. The samples were characterized as-deposited and after thermal annealing, so that Al transport could be studied. An estimated depth resolution of approximately 0.4 nm near the surface of the films could be obtained owing to: (i) the very small resonance width; (ii) the high stopping power of Al 2 O 3 for 404.9 keV protons; (iii) the high energy stability of the proton beam provided by the 500 kV HVEE ion implanter at Porto Alegre; and (iv) an apparent thickness magnification by a factor between 2.0 and 2.4 with the use of glancing incidence. This technique is compared to other methods for Al profiling like medium energy ion scattering and some sputtering-based techniques

Neoclassical resonant transport of a mirror cell

International Nuclear Information System (INIS)

Ito, T.; Katanuma, I.

2005-01-01

The neoclassical resonant plateau transport in a mirror cell is studied theoretically. The analytical expression for a non-square-well magnetic field is obtained. The analytical result is applied to the GAMMA10 tandem mirror [T. Cho, M. Yoshida, J. Kohagura et al., Phys. Rev. Lett. 94, 085002-1 (2005)], which consists of several mirror cells in it, and the confinement time due to the neoclassical resonant plateau transport is determined in each mirror cell. It is found that the neoclassical resonant transport of ions trapped in the nonaxisymmetric anchor mirror cell and transition mirror cells is significantly smaller than those trapped in the central cell

Moessbauer and transport studies of amorphous and icosahedral Zr-Ni-Cu-Ag-Al alloys

International Nuclear Information System (INIS)

Stadnik, Z.M.; Rapp, O.; Srinivas, V.; Saida, J.; Inoue, A.

2002-01-01

The alloy Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 in the amorphous and icosahedral states, and the bulk amorphous alloy Zr 65 Al 7.5 Ni 10 Cu 7.5 Ag 10 , have been studied with 57 Fe Moessbauer spectroscopy, electrical resistance and magnetoresistance techniques. The average quadrupole splitting in both alloys decreases with temperature as T 3/2 . The average quadrupole splitting in the icosahedral alloy is the largest ever reported for a metallic system. The lattice vibrations of the Fe atoms in the amorphous and icosahedral alloys are well described by a simple Debye model, with the characteristic Moessbauer temperatures of 379(29) and 439(28) K, respectively. Amorphous alloys Zr 65 Al 7. )5Ni 10 Cu 7.5 Ag 10 and Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 have been found to be superconducting with the transition temperature, T c , of about 1.7 K. The magnitude of Tc and the critical field slope at Tc are in agreement with previous work on Zr-based amorphous superconductors, while the low-temperature normal state resistivity is larger than typical results for binary and ternary Zr-based alloys. The resistivity of icosahedral Zr 65 Al 7.5 Ni 10 Cu 7.3 Fe 0.2 Ag 10 is larger than that for the amorphous ribbon of the same composition, as inferred both from direct measurements on the ribbons and from the observed magnetoresistance. However the icosahedral sample is non-superconducting in the measurement range down to 1.5 K. The results for the resistivity and the superconducting T c both suggest a stronger electronic disorder in the icosahedral phase than in the amorphous phase. (author)

Didáctica del dibujo de contornos ciegos aplicada al retrato gráfico = Teaching the blind contours drawing applied to graphic portrait

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Ignacio Martínez de Salazar Muñoz

2016-07-01

Full Text Available Resumen En el área de la enseñanza del Dibujo Artístico, el retrato es una de las temáticas más complejas e interesantes a las que un estudiante debe enfrentarse. Con una larga tradición en las artes plásticas este género gráfico ofrece un campo de estudio excepcional para la adquisición de competencias básicas relacionada con la praxis del dibujo. El presente artículo muestra los resultados de una propuesta didáctica realizada con estudiantes en el contexto de los estudios universitarios de Diseño. Los objetivos que este estudio persigue son proporcionar una estrategia didáctica complementaria a los métodos de enseñanza del Dibujo Artístico, ofreciendo al docente y al estudiante herramientas que favorezcan la comprensión, validación y ejecución del retrato gráfico. Abstract In the Artistic Drawing education, the portrait is one of the most complex and interesting topics to which students must face. With a long tradition within the plastic arts, this graphic genre offers an unique field of study to acquire basic skills related to the practice of drawing. This artículo reports the results of an innovative didactic project performed with university students of the Design studies. The aim of the project is to provide a complementary teaching strategy to the traditional methods of the Artistic Drawing training. It offers to both, the teacher and the students, distinct tools to promote the understanding, validation and implementation of the graphic portrait.

Molecular motor transport through hollow nanowires

DEFF Research Database (Denmark)

Lard, Mercy; Ten Siethoff, Lasse; Generosi, Johanna

2014-01-01

-driven motion of fluorescent probes (actin filaments) through 80 nm wide, Al2O 3 hollow nanowires of micrometer length. The motor-driven transport is orders of magnitude faster than would be possible by passive diffusion. The system represents a necessary element for advanced devices based on gliding assays...

Aluminum-Activated Malate Transporters Can Facilitate GABA Transport.

Science.gov (United States)

Ramesh, Sunita A; Kamran, Muhammad; Sullivan, Wendy; Chirkova, Larissa; Okamoto, Mamoru; Degryse, Fien; McLaughlin, Michael; Gilliham, Matthew; Tyerman, Stephen D

2018-05-01

Plant aluminum-activated malate transporters (ALMTs) are currently classified as anion channels; they are also known to be regulated by diverse signals, leading to a range of physiological responses. Gamma-aminobutyric acid (GABA) regulation of anion flux through ALMT proteins requires a specific amino acid motif in ALMTs that shares similarity with a GABA binding site in mammalian GABA A receptors. Here, we explore why TaALMT1 activation leads to a negative correlation between malate efflux and endogenous GABA concentrations ([GABA] i ) in both wheat ( Triticum aestivum ) root tips and in heterologous expression systems. We show that TaALMT1 activation reduces [GABA] i because TaALMT1 facilitates GABA efflux but GABA does not complex Al 3+ TaALMT1 also leads to GABA transport into cells, demonstrated by a yeast complementation assay and via 14 C-GABA uptake into TaALMT1 -expressing Xenopus laevis oocytes; this was found to be a general feature of all ALMTs we examined. Mutation of the GABA motif (TaALMT1 F213C ) prevented both GABA influx and efflux, and resulted in no correlation between malate efflux and [GABA] i We conclude that ALMTs are likely to act as both GABA and anion transporters in planta. GABA and malate appear to interact with ALMTs in a complex manner to regulate each other's transport, suggestive of a role for ALMTs in communicating metabolic status. © 2018 American Society of Plant Biologists. All rights reserved.

Problemas éticos al final de la vida

Directory of Open Access Journals (Sweden)

Maria Graciela De Ortuzar

2014-06-01

Full Text Available El presente informe trata sobre el análisis filosófico de un tema complejo y controvertido, como lo es la ?definición de muerte?. Por ello, es importante subrayar que no desarrollaré aquí los aspectos antropológicos, sicológicos, médicos y técnicos de la muerte. Sólo me centraré en las teorías filosóficas principales que justifican diferentes definiciones de muerte (esencialista vs. biológica y sus consecuentes problemas prácticos. La necesidad de realizar esta investigación surge a partir del reconocimiento de confusiones conceptuales y contradicciones cuando se comunica ?la muerte? (falta de concordancia entre la definición filosófica, criterios y tests; contradicciones reflejadas cotidianamente en el lenguaje y en las actitudes del personal médico y de enfermería de nuestras Unidades de Terapia Intensiva (UTIs. Hablar de paciente al referirse a un cadáver al que se le ha diagnosticado la muerte encefálica; hablar de muerte cuando se produce el paro cardiorespitariaco (¿dos muertes?; hablar de eutanasia cuando se retira el respirador al individuo muerto cuyos órganos están siendo mantenidos artificialmente; éstas situaciones -entre otras- reflejan conflictos y falta de claridad conceptual sobre los conceptos básicos de muerte y eutanasia. Dichos conflictos constituyen problemas éticos claves al final de la vida, los cuáles nacen a partir del reciente cambio en el criterio de muerte en un contexto de acelerada ?tecnologización? de la salud. He aquí la necesidad del análisis crítico sobre el marco teórico-conceptual requerido en UTIs y su confrontación aplicada, con el fin de esclarecer los citados problemas. Para ello, estudiaré la teoría moral unificada de Bernard Gert, examinando su justificación teórica y su aplicabilidad práctica, como así también las posiciones alternativas a la misma (Wikler. En términos generales, considero que la defensa de la coherencia, sistematicidad y aplicabilidad de las

an appraisal of transportation facilities effects on agricultural

African Journals Online (AJOL)

Osondu

2013-02-27

Feb 27, 2013 ... Findings show that mode of transportation in the study area is mostly through head- porterage and to ... agricultural production, commodities and markets. Crosssley et al. .... research. Section A: Socio-economics information of.

Organophosphate Related Alterations in Myelin and Axonal Transport in the Living Mammalian Brain

Science.gov (United States)

2015-10-01

function, neuroinflammation, al- tered neurotrophin responses, etc. (reviewed, Soltaninejad and Abdollahi, 2009; Banks and Lein, 2012; Terry, 2012). Conflict...JN, Middlemore ML, Williamson LN, et al. Chronic, intermittent exposure to chlorpyrifos in rats: protracted effects on axonal transport, neurotrophin

Diccionario de geografía aplicada y profesional: terminología de análisis, planificación y gestión del territorio

Directory of Open Access Journals (Sweden)

Isabel Duque Franco

2016-02-01

Full Text Available El Diccionario de geografía aplicada y profesional: terminología de análisis, planificación y gestión del territorio, es un proyecto editorial dirigido por Lorenzo López Trigal, catedrático de Geografía Humana y profesor emérito de la Universidad de León (España. Se trata de una contribución oportuna y necesaria para la Geografía y otras disciplinas afines, desde y para el contexto iberoamericano, teniendo en cuenta que es un trabajo de colaboración con autores de siete nacionalidades, entornos académicos y profesionales distintos (españoles, portugueses, brasileños, argentinos, venezolanos, mexicanos y colombianos.

a-Axis GaN/AlN/AlGaN Core-Shell Heterojunction Microwires as Normally Off High Electron Mobility Transistors.

Science.gov (United States)

Song, Weidong; Wang, Rupeng; Wang, Xingfu; Guo, Dexiao; Chen, Hang; Zhu, Yuntao; Liu, Liu; Zhou, Yu; Sun, Qian; Wang, Li; Li, Shuti

2017-11-29

Micro/nanowire-based devices have been envisioned as a promising new route toward improved electronic and optoelectronic applications, which attracts considerable research interests. However, suffering from applicable strategies to synthesize uniform core-shell structures to meet the requirement for the investigations of electrical transport behaviors along the length direction or high electron mobility transistor (HEMT) devices, heterojunction wire-based electronics have been explored limitedly. In the present work, GaN/AlN/AlGaN core-shell heterojunction microwires on patterned Si substrates were synthesized without any catalyst via metalorganic chemical vapor deposition. The as-synthesized microwires had low dislocation, sharp, and uniform heterojunction interfaces. Electrical transport performances were evaluated by fabricating HEMTs on the heterojunction microwire channels. Results demonstrated that a normally off operation was achieved with a threshold voltage of 1.4 V, a high on/off current ratio of 10 8 , a transconductance of 165 mS/mm, and a low subthreshold swing of 81 mV/dec. The normally off operation may attribute to the weak polarization along semipolar facets of the heterojunction, which leads to weak constrain of 2DEG.

ALS Associated Mutations in Matrin 3 Alter Protein-Protein Interactions and Impede mRNA Nuclear Export.

Science.gov (United States)

Boehringer, Ashley; Garcia-Mansfield, Krystine; Singh, Gurkaran; Bakkar, Nadine; Pirrotte, Patrick; Bowser, Robert

2017-11-06

Mutations in Matrin 3 have recently been linked to ALS, though the mechanism that induces disease in these patients is unknown. To define the protein interactome of wild-type and ALS-linked MATR3 mutations, we performed immunoprecipitation followed by mass spectrometry using NSC-34 cells expressing human wild-type or mutant Matrin 3. Gene ontology analysis identified a novel role for Matrin 3 in mRNA transport centered on proteins in the TRanscription and EXport (TREX) complex, known to function in mRNA biogenesis and nuclear export. ALS-linked mutations in Matrin 3 led to its re-distribution within the nucleus, decreased co-localization with endogenous Matrin 3 and increased co-localization with specific TREX components. Expression of disease-causing Matrin 3 mutations led to nuclear mRNA export defects of both global mRNA and more specifically the mRNA of TDP-43 and FUS. Our findings identify a potential pathogenic mechanism attributable to MATR3 mutations and further link cellular transport defects to ALS.

Cocriação de valor no transporte rodoviário de carga fracionada: um estudo de caso

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Max Roberto da Silva

2015-06-01

Full Text Available Este artigo investiga se a cocriação de valor pode ser aplicada pelos prestadores de serviços de transporte. O estudo focalizou os transportadores e operadores logísticos. Um estudo de caso múltiplo foi realizado. Constructos afetos ao tema cocriação de valor foram extraídos da literatura para a consolidação da fundamentação teórica da pesquisa. Os seguintes tópicos foram investigados: demandas de valor dos compradores, critérios utilizados pelos compradores para avaliar o valor oferecido pelos prestadores de serviços e a possibilidade de cocriação de valor entre os compradores e vendedores. Os achados apontam duas principais barreiras para a cocriação de valor nos serviços de transporte, a saber: um grande número de prestadores de serviços (o que força os provedores de serviço a focalizar essencialmente a dimensão custo dos serviços e as exigências dos clientes. A combinação dos referidos elementos sugere a impossibilidade de adoção de cocriação no contexto estudado. Esses resultados também podem indicar a existência de um limite inferior para a abordagem de valor no setor de serviços (por caso, nos serviços de transporte de carga.

LA UNIVERSIDAD COMO ESPACIO DE INTERVENCIÓN EN ORIENTACIÓN PROFESIONAL: UNA EXPERIENCIA EN LA UNIVERSIDAD PERUANA DE CIENCIAS APLICADAS

Directory of Open Access Journals (Sweden)

Patricia Navarrete Talavera

2007-12-01

Full Text Available RESUMEN: El presente artículo constituye una reflexión acerca de la universidad como un espacio de intervención en la orientación vocacional y profesional. Ha sido realizada a la luz de los trabajos y la discusión teórica actual, tomando como referencia la experiencia desarrollada por la Universidad Peruana de Ciencias Aplicadas1. La orientación profesional es una continuación de la orientación vocacional que tradicionalmente se circunscribe al momento de elección de la carrera. En la actualidad dada la acelerada generación de conocimientos y las demandas de capacitación continua, la orientación cobra un papel primordial en la formación profesional de los estudiantes y, por lo tanto, en el sistema universitario que los alberga. Se hace necesaria entonces la elaboración de nuevas propuestas de trabajo que contemplen conjuntamente el modelo educativo, la labor de los docentes, los servicios de bolsa de trabajo y el Área de Orientación. ABSTRACT: The present article constitutes a reflection about the University as a space for intervention in vocational and professional orientation, taking into account the work presently done as well as the actual theoretical discussions and taking as a reference the experiences that are being developed at the Peruvian University of Applied Sciences nowadays. Professional orientation is conceived as the meaning and importance that the vocational development of a person has, understanding that this does not necessarily corresponds to one moment in your life, but that it develops in a permanent manner during your entire life cycle. Given that, in the world that we live in, the generation of knowledge and the demands for training are continuous, orientation takes a primordial role in the professional formation of the students and thus, in the University’s system that shelters us too. Therefore, it becomes necessary to generate new job offers that contemplate jointly: the educational model, the

¡Alucinados por paisajes! Indicadores para una relectura del paisaje regional

Directory of Open Access Journals (Sweden)

Fabio Aldemar Gómez Sierra

2011-10-01

Full Text Available Otra forma de administrar las localidades en la globalización, es la vinculación del paisaje con las expresiones culturales. Ese, depende de las miradas naturales o fotografiadas, sometidas ambas a la subjetividad. La acepción aplicada al entorno, se expresa como espectáculo rural, dotado de patrimonios, cuyas concepciones poéticas, románticas y turísticas, obstaculizan más posibilidades. Aunque al departamento de Boyacá se le identifique parcialmente como territorio de paisajes, dicho concepto, alejado de las categorías científicas es pasivo y contemplativo. Enriquecerlo con miradas y procedimientos fundamentados, desde la experiencia de los paisajes vitícolas y hablar de la ciencia del paisaje, articulada con disciplinas científicas y aplicadas, permitiría la movilidad de conocimientos y por ende, una transformación social.

Microevolution of ALS inhibitor herbicide resistance in loose silky bentgrass (Apera spica-venti)

DEFF Research Database (Denmark)

Babineau, Marielle

, the ALS resistant biotypes have a fitness advantage over the susceptible biotype in time to germination and time to flowering and seed production growth stages. This study increased the understanding of the spatial, phenotypic, genetic and ecological processes and consequences in ALS herbicide resistance......-neighborhood experiments were conducted with ALS resistant and susceptible populations with a randomized genetic background, vegetative and reproductive growth stages were compared. The results show a large variation in the response of neighboring populations to ALS herbicide. Multiple resistance is observed between ALS...... from known metabolic herbicide resistance pathways, such as cytochrome P450s, ABC-transporters, UDP-glycosyltransferase and glutathione S-transferase, are identified and quantified. Different gene families are up-regulated at different times after herbicide treatment. In low competition conditions...

ATACAMA, DE LA CRISIS TEMPORAL A LA CRISIS PERMANENTE. LA MINERÍA DEL COBRE EN LA SEGUNDA MITAD DEL SIGLO XIX

Directory of Open Access Journals (Sweden)

Hernán Venegas Valdebenito

2011-10-01

Full Text Available La provincia de Atacama constituyó uno de los escenarios de transformación económica más dinámicos del siglo XIX. En ese marco este trabajo sintetiza las transformaciones operadas en la industria minera del cobre en la segunda mitad del siglo XIX, centrando su enfoque sobre los factores de inestabilidad generados por los ciclos cortos de recesión económica y la sensibilidad de los productores locales frente a los cambios operados en el mercado internacional. Al mismo tiempo, se analiza la posición del gremio minero en algunas de esas coyunturas negativas y su particular visión en torno a los problemas relativos al mercado laboral, a las dificultades de transporte, la competencia externa y la política tributaria aplicada por el Estado chileno. El trabajo enfatiza la distinta intensidad con que se manifiestan estos ciclos recesivos entre los actores productivos locales, lo que a su vez profundiza los procesos de diferenciación económica en aquella región minera.

Una aproximación metodológica al estudio integrado del transporte urbano de carga: el caso de la Zona Metropolitana de Querétaro en México

OpenAIRE

Eduardo Betanzo-Quezada

2011-01-01

El transporte urbano de mercancías adquiere importancia en el mundo actual al reconocerse sus efectos nocivos sobre el medio ambiente y la calidad de vida de la población. En el tema de la planificación de las ciudades y sus movimientos de carga, los países y ciudades han experimentado limitaciones tales como la falta de datos, metodologías, análisis y referencias en un campo relativamente reciente. Para entender esta problemática, este artículo tiene como objetivo poner en relieve el estado ...

Transportation System Risk Assessment on DOE Defense Program shipments

International Nuclear Information System (INIS)

Brumburgh, G.P.; Kimura, C.Y.; Alesso, H.P.; Prassinos, P.G.

1992-01-01

Substantial effort has been expended concerning the level of safety provided to persons, property, and the environment from the hazards associated with transporting radioactive material. This work provided an impetus for the Department of Energy to investigate the use of probabilistic risk assessment techniques to supplement the deterministic approach to transportation safety. The DOE recently decided to incorporate the methodologies associated with PRAs in the process for authorizing the transportation of nuclear components, special assemblies, and radioactive materials affiliated with the DOE Defense Program. Accordingly, the LLNL, sponsored by the DOE/AL, is tasked with developing a safety guide series to provide guidance to preparers performing a transportation system risk assessment

Telematics for hazardous goods transportation; Anwendungen fuer den Transport von kritischen Guetern

Energy Technology Data Exchange (ETDEWEB)

Stingl, D [Danzas Logistics GmbH, Hamburg (Germany)

1999-07-01

In the course of the integration of the customer Langnese Iglo in autumn 1997 and in view of the already existing general conditions for the implementation of the equlations of the directive on food hygiene (HACCP-concept) as well as the permanently in reasing demand for quality of logistics DANZAS Logistics GmbH, cooperating closely with in deep-frozen goods customer Langnese-Iglo decided to develop a new system of quality assurance for the transportation of deep-frozen goods and apply this system to all its activities. First ideas about standard demands, technical solutions and multi-functional design showed that the project had to be handled in such a flexible way that temperature controlling (for the transportation of deep-frozen goods, temperature-controlled DANZAS-warehouses and all future temperature-controlled transportation) and the monitoring of security-relevant transportation can be integrated in one and the same project. (orig.) [German] Im Zuge der Integration des Kunden Langnese Iglo im Herbst 1997 und unter Beruecksichtigung der bereits vorliegenden Rahmenbedingungen zur Umsetzung der Bestimmungen der Lebensmittelhygieneverordnung (HACCP-Konzept) sowie des staendig wachsenden Qualitaetsanspruches an logistische Dienstleistungen, hat sich die DANZAS Logistics GmbH in enger Zusammenarbeit mit dem TK-Kunden Langnese Iglo entschlossen, ein innovatives System zur Qualitaetssicherung im Tiefkuehltransport zu erarbeiten und flaechendeckend einzusetzen. Die ersten Gedanken bezueglich Standardanforderungen, technischer Loesungsansaetze und multifunktionaler Ausrichtung zeigten, dass dieses Projekt so variabel zu gestalten ist, dass sowohl Temperaturcontrolling (fuer TK-Transporte, fuer die temperaturgefuehrten DANZAS-Laeger und zukuenftig alle temperaturgefuehrten Transporte) als auch die Ueberwachung sicherheitsrelevanter Transporte zu integrieren sind. (orig.)

From Schottky to Ohmic graphene contacts to AlGaN/GaN heterostructures: Role of the AlGaN layer microstructure

International Nuclear Information System (INIS)

Fisichella, G.; Greco, G.; Roccaforte, F.; Giannazzo, F.

2014-01-01

The electrical behaviour of graphene (Gr) contacts to Al x Ga 1−x N/GaN heterostructures has been investigated, focusing, in particular, on the impact of the AlGaN microstructure on the current transport at Gr/AlGaN interface. Two Al 0.25 Ga 0.75 N/GaN heterostructures with very different quality in terms of surface roughness and defectivity, as evaluated by atomic force microscopy (AFM) and transmission electron microscopy, were compared in this study, i.e., a uniform and defect-free sample and a sample with a high density of typical V-defects, which locally cause a reduction of the AlGaN thickness. Nanoscale resolution current voltage (I-V) measurements by an Au coated conductive AFM tip were carried out at several positions both on the bare and Gr-coated AlGaN surfaces. Rectifying contacts were found onto both bare AlGaN surfaces, but with a more inhomogeneous and lower Schottky barrier height (Φ B  ≈ 0.6 eV) for AlGaN with V-defects, with respect to the case of the uniform AlGaN (Φ B  ≈ 0.9 eV). Instead, very different electrical behaviours were observed in the presence of the Gr interlayer between the Au tip and AlGaN, i.e., a Schottky contact with reduced barrier height (Φ B ≈ 0.4 eV) for the uniform AlGaN and an Ohmic contact for the AlGaN with V-defects. Interestingly, excellent lateral uniformity of the local I-V characteristics was found in both cases and can be ascribed to an averaging effect of the Gr electrode over the AlGaN interfacial inhomogeneities. Due to the locally reduced AlGaN layer thickness, V defect act as preferential current paths from Gr to the 2DEG and can account for the peculiar Ohmic behaviour of Gr contacts on defective AlGaN

Aplicación de la metodología de intervención psicosocial de la Asociación de Expertos en Psicosociología Aplicada - AEPA en una empresa siderometalúrgica

OpenAIRE

López-Barón, Francisco; Carrión García, M. Ángeles

2014-01-01

Peer-reviewed Estudio de caso de la intervención psicosocial en una empresa siderometalúrgica aplicando la metodología de intervención psicosocial de la Asociación de Expertos enb Psicosociología Aplicada - AEPA. A case study of psycho-social intervention in an iron and steel company applying the methodology of psychosocial intervention of the Association of Applied Psychology Experts - AEPA. Estudi de cas de la intervenció psicosocial en una empresa siderometal·lúrgica aplicant la m...

Simulation of Tracer Transport in Porous Media: Application to Bentonites; Simulacion del Transporte de Trazadores en Medios Porosos: Aplicacion al Caso de Arcillas

Energy Technology Data Exchange (ETDEWEB)

Bru, A; Casero, D [CIEMAT, Madrid (Spain)

2001-07-01

We present a formal framework to describe tracer transport in heterogeneous media, such as porous media like bentonites. In these media, mean field approximation is not valid because there exist some geometrical constraints and the transport is anomalous. (Author)

Econometría Espacial Aplicada a la Agricultura de Precisión

Directory of Open Access Journals (Sweden)

Rodolfo Bongiovanni

2013-04-01

Full Text Available La agricultura de precisión se define como la “aplicación de tecnologías y principios de manejo de cultivos para manejar la variabilidad espacio-temporal asociada a la producción agrícola”.El artículo muestra cómo la econometría espacial se puede aplicar al estudio de los datos del monitor de rendimiento para estimar la respuesta del cultivo al fertilizante.En un estudio de caso de fertilización del maíz con nitrógeno en 1998-99 indican: hay autocorrelación espacial y heterocedasticidad en la respuesta del maíz; la respuesta al nitrógeno y las dosis óptimas de nitrógeno difieren en las distintas posiciones topográficas dentro del lote; la dosis variable de nitrógeno es rentable a un costo extra de USD 6 ha-1; la respuesta al nitrógeno y las dosis óptimas por posición en el lote difieren de año en año.Este resultado es interesante y alienta el uso de la econometría espacial en modelos espaciales, como una herramienta efectiva para determinar la rentabilidad de la dosis variable. Se debe tener en cuenta que se trata de un análisis “ex-post”, es decir, se asume que la respuesta del cultivo al N se conoce al momento de realizar la fertilización. A pesar de que la respuesta esperada nunca se va a conocer con certeza, un análisis económico de este tipo es el punto de partida que permite comenzar a comprender las implicaciones del manejo sitio-específico.

A Krylov Subspace Method for Unstructured Mesh SN Transport Computation

International Nuclear Information System (INIS)

Yoo, Han Jong; Cho, Nam Zin; Kim, Jong Woon; Hong, Ser Gi; Lee, Young Ouk

2010-01-01

Hong, et al., have developed a computer code MUST (Multi-group Unstructured geometry S N Transport) for the neutral particle transport calculations in three-dimensional unstructured geometry. In this code, the discrete ordinates transport equation is solved by using the discontinuous finite element method (DFEM) or the subcell balance methods with linear discontinuous expansion. In this paper, the conventional source iteration in the MUST code is replaced by the Krylov subspace method to reduce computing time and the numerical test results are given

Thermal conductivity of layered borides: The effect of building defects on the thermal conductivity of TmAlB4 and the anisotropic thermal conductivity of AlB2

Directory of Open Access Journals (Sweden)

X. J. Wang

2014-04-01

Full Text Available Rare earth metal borides have attracted great interest due to their unusual properties, such as superconductivity and f-electron magnetism. A recent discovery attributes the tunability of magnetism in rare earth aluminoborides to the effect of so-called “building defects.” In this paper, we report data for the effect of building defects on the thermal conductivities of α-TmAlB4 single crystals. Building defects reduce the thermal conductivity of α-TmAlB4 by ≈30%. At room temperature, the thermal conductivity of AlB2 is nearly a factor of 5 higher than that of α-TmAlB4. AlB2 single crystals are thermally anisotropic with the c-axis thermal conductivity nearly twice the thermal conductivity of the a-b plane. Temperature dependence of the thermal conductivity near and above room temperature reveals that both electrons and phonons contribute substantially to thermal transport in AlB2 with electrons being the dominant heat carriers.

Wetting phenomena of Al-Cu alloys on sapphire below 800 deg. C

International Nuclear Information System (INIS)

Klinter, Andreas J.; Leon-Patino, Carlos A.; Drew, Robin A.L.

2010-01-01

Using a modified dispensed drop method, a decrease in contact angle on sapphire from pure aluminum to low-copper-containing Al alloys (7-12 wt.%) was found; with higher copper additions θ transitions to the non-wetting regime. Atomic force microscopy on long-term samples showed a significantly increased surface roughness beneath the drop. Using high-resolution transmission electron microscopy, the reaction product at the interface was identified as CuAl 2 O 4 for Al-7Cu and Al 2 O 3 for an Al-99.99 drop. X-ray photoelectron spectroscopy further confirmed the formation of CuAl 2 O 4 under CuAl 2 drops. Spinel formation is caused by reaction of the alloy with residual oxygen in the furnace that is transported along the interface as modeled by thermodynamic simulations. The formation of CuAl 2 O 4 causes the reduced σ sl and hence the improved wettability of sapphire by low-copper-containing alloys compared to pure aluminum. The main reason for the increase in θ with higher copper contents is the increasing σ lv of the alloy.

Laser field effects on the transport phenomena: Energy loss and stopping power

International Nuclear Information System (INIS)

Torres Silva, H.; Sakanaka, P.H.

1990-01-01

The energy loss method has been applied to a large variety of transport problems in optics, solid-state and fusion research. In these papers, however, the transport equations were linearized, so there are no multiphoton interaction. On the other hand, Bivona et al. (1982) [2] have shown that, for a one-component plasma, the strong field effects would be only of academic interest. On the basis of the center of mass approach [3], a generalization of the energy loss rate which is in accordance with the recent results of Arista et al. (1989) [4] is obtained. (Author)

Fenómenos de transporte en sistemas semiconductores cuánticos confinados

OpenAIRE

Aguado Sola, Ramón

1997-01-01

Analiza el transporte en presencia de potenciales dependientes del tiempo en diferentes sistemas y completado con el estudio de otros problemas, relativos siempre al transporte, como los efectos debidos a la interacción electrón-eletrón o los debidos a campos magnéticos externos. Estudia las propiedades del transporte asistido por fotones de un diodo de doble barrera, desarrolla un modelo teórico que permite estudiar el transporte coherente en presencia de potenciales dependientes del tie...

Fabrication of Nb3Al superconducting wires by utilizing the mechanically alloyed Nb(Al)ss supersaturated solid-solution with low-temperature annealing

International Nuclear Information System (INIS)

Pan, X.F.; Yan, G.; Qi, M.; Cui, L.J.; Chen, Y.L.; Zhao, Y.; Li, C.S.; Liu, X.H.; Feng, Y.; Zhang, P.X.; Liu, H.J.

2014-01-01

Highlights: • This paper reported superconducting properties of the powder-in-tube Nb 3 Al wires. • The Nb 3 Al wires were made by using Nb(Al) ss supersaturated solid solution powders. • The Cu-matrix Nb 3 Al superconducting wires have been successfully fabricated. • The transport J c of Nb 3 Al wires at 4.2 K, 10 T is up to 12,700 A/cm 2 . - Abstract: High-performance Nb 3 Al superconducting wire is a promising candidate to the application of high-field magnets. However, due to the production problem of km-grade wires that are free from low magnetic field instability, the Nb 3 Al wires made by rapid heating, quenching and transformation (RHQT) are still not available to the large-scale engineering application. In this paper, we reported the properties of the in situ powder-in-tube (PIT) Nb 3 Al superconducting wires, which were made by using the mechanically alloyed Nb(Al) ss supersaturated solid solution, as well as the low temperature heat-treatment at 800 °C for 10 h. The results show that Nb 3 Al superconductors in this method possess very fine grains and well superconducting properties, though a little of Nb 2 Al and Nb impurities still keep being existence at present work. At the Nb 3 Al with a nominal 26 at.% Al content, the onset T c reaches 15.8 K. Furthermore, a series of Nb 3 Al wires and tapes with various sizes have been fabricated; for the 1.0 mm-diameter wire, the J c at 4.2 K, 10 T and 14 T have achieved 12,700 and 6900 A/cm 2 , respectively. This work suggests it is possible to develop high-performance Cu-matrix Nb 3 Al superconducting wires by directly using the Nb(Al) ss supersaturated solid-solution without the complex RHQT heat-treatment process

Tritium permeation characterization of Al{sub 2}O{sub 3}/FeAl coatings as tritium permeation barriers on 321 type stainless steel containers

Energy Technology Data Exchange (ETDEWEB)

Yang, Feilong; Xiang, Xin; Lu, Guangda; Zhang, Guikai, E-mail: zhangguikai@caep.cn; Tang, Tao; Shi, Yan; Wang, Xiaolin

2016-09-15

Accurate tritium transport properties of prospective tritium permeation barriers (TPBs) are essential to tritium systems in fusion reactors. By passing a temperature and rate-controlled sweeping gas over specimen surfaces to carry the permeated tritium to an ion chamber, the gas-driven permeation of tritium has been performed on 321 type stainless steel containers with Al{sub 2}O{sub 3}/FeAl barriers, to determine the T-permeation resistant performance and mechanism of the barrier. The tritium permeability of the Al{sub 2}O{sub 3}/FeAl coated container was reduced by 3 orders of magnitude at 500–700 °C by contrast with that of the bare one, which meets the requirement of the tritium permeation reduction factor (PRF) of TPBs for tritium operating components in the CN-HCCB TBM. The Al{sub 2}O{sub 3}/FeAl barrier resists the tritium permeation by the diffusion in the bulk substrate at a limited number of defect sites with an effective area and thickness, suggesting that the TPB quality is a very important factor for efficient T-permeation resistance. - Highlights: • T-permeation has been measured on bare and coated type 321 SS containers. • Al{sub 2}O{sub 3}/FeAl coating give a reduction of T-permeability of 3 orders of magnitude. • Mechanism of Al{sub 2}O{sub 3}/FeAl barrier resisting T-permeation has obtained. • Quality of TPB is a very important factor for efficient T-permeating reduction.

Biotecnología aplicada Un logro del Grupo BIOSEC

Directory of Open Access Journals (Sweden)

Marina Caro Muñoz

2008-07-01

Full Text Available Un sueño hecho realidad, de la academia al campo, gracias a la unión de la empresa privada, Metapetroleum Company, y las entidades públicas Alcaldía de Puerto Gaitán y el Grupo Biosec del Instituto de Biotecnología de la Universidad Nacional de Colombia.

Revisión de herramientas aplicadas al modelamiento de mercados de electricidad

Directory of Open Access Journals (Sweden)

Sandra Milena Londoño Hernández

2009-09-01

Full Text Available La desregulación de los mercados de electricidad alrededor del mundo, en la búsqueda de la eficiencia, ha introducido compe- tencia en los sectores de comercialización y generación de energía. Por esta razón, ha adquirido gran importancia, para regula- dores y oferentes, estudiar la interacción de los agentes competitivos para analizar la evolución del mercado y definir adecuada- mente estrategias de ofertamiento. Por lo tanto, en los últimos años se han utilizado diferentes herramientas para modelar los mercados de electricidad competitivos; este artículo presenta una revisión analítica de la bibliografía encontrada en el tema, en la cual se presentan las herramientas más utilizadas, además de sus ventajas y desventajas. Para realizar este análisis se hicieron comparaciones entre los modelos utilizados en cada herramienta, identificando las principales características del mercado, tales como esquema de mercado, estructura de las ofertas, tipo de subasta, entre otras. De este análisis se concluye que el tipo de herramienta a utilizar depende en gran medida del objetivo y alcance que se busca con el estudio.

Life cycle assessment in support of sustainable transportation

Science.gov (United States)

Eckelman, Matthew J.

2013-06-01

In our rapidly urbanizing world, sustainable transportation presents a major challenge. Transportation decisions have considerable direct impacts on urban society, both positive and negative, for example through changes in transit times and economic productivity, urban connectivity, tailpipe emissions and attendant air quality concerns, traffic accidents, and noise pollution. Much research has been dedicated to quantifying these direct impacts for various transportation modes. Transportation planning decisions also result in a variety of indirect environmental and human health impacts, a portion of which can accrue outside of the transit service area and so outside of the local decision-making process. Integrated modeling of direct and indirect impacts over the life cycle of different transportation modes provides decision support that is more comprehensive and less prone to triggering unintended consequences than a sole focus on direct tailpipe emissions. The recent work of Chester et al (2013) in this journal makes important contributions to this research by examining the environmental implications of introducing bus rapid transit and light rail in Los Angeles using life cycle assessment (LCA). Transport in the LA region is dominated by automobile trips, and the authors show that potential shifts to either bus or train modes would reduce energy use and emissions of criteria air pollutants, on an average passenger mile travelled basis. This work compares not just the use of each vehicle, but also upstream impacts from its manufacturing and maintenance, as well as the construction and maintenance of the entire infrastructure required for each mode. Previous work by the lead author (Chester and Horvath 2009), has shown that these non-operational sources and largely non-local can dominate life cycle impacts from transportation, again on an average (or attributional) basis, for example increasing rail-related GHG emissions by >150% over just operational emissions

IMPLEMENTASI MAQĀṢID AL-SHARĪ'AH DALAM HUKUM EKONOMI ISLAM

Directory of Open Access Journals (Sweden)

Syufa'at

2013-10-01

Full Text Available The objective revelation of Islamic law is to create public interest (maṣlaḥat, both individually and collectively. The public interest that mentioned in Islamic law is the true goodness, not the pseudo benefit which influenced human desires. The Public interest here includes physical and spiritual. The public interest that intended by Islamic law is the goodness in this life and in the hereafter, not solely in the world live. maslahah in the Shariah perspective is based on five principles called al-mabādi'al-khamsah or al-uṣūl alkhamsah namely: keeping religion (hifẓ al-dīn, keeping the soul (hifẓ al-nafs, keeping mind (hifẓ al-‘aql, keeping property (hifẓ al-māl, and keeping descent (hifẓ al-nasl. Maqāṣid al-sharī’ah implementation of some economic problems is to answer the reality of modern society to face the challenges of basic needs such as clothing, food, shelter, health, education, employment, sanitation, energy, transport and information. Crucial needs of modern man is the spiritual and ethical, because modern society only measure the welfare just from the outer side only, that is to meet the needs according to the principle of utility and pragmatism

Non-equilibrium spin and charge transport in superconducting heterojunctions

Energy Technology Data Exchange (ETDEWEB)

Thalmann, Marcel; Rudolf, Marcel; Braun, Julian; Pietsch, Torsten; Scheer, Elke [Department of Physics, University of Konstanz, Universitaetsstrasse 10, 78464 Konstanz (Germany)

2015-07-01

Ferromagnet Superconductance (F/S) junctions are rich in exciting quantum-physical-phenomena, which are still poorly understood but may provide bright prospects for new applications. In contrast to conventional normal-metal proximity systems, Andreev reflection is suppressed for singlet cooper pairs in F/S heterostructures. However, long-range triplet pairing may be observed in S/F systems with non-collinear magnetization or spin-active interfaces. Herein, we investigate non-equilibrium transport properties of lateral S/F heterojunctions, defined via electron beam lithography. In particular we focus microwave- and magneto-transport spectroscopy on conventional type-I (Al, Pb, Zn) and type-II (Nb) superconductors in combination with strong transition metal ferromagnets (Ni, Co, Fe). A cryogenic HF readout platform and advanced electronic filtering is developed and results on Al-based heterojunctions are shown.

Thermal stability and in situ SiN passivation of InAlN/GaN high electron mobility heterostructures

Energy Technology Data Exchange (ETDEWEB)

Lugani, L.; Carlin, J.-F.; Py, M. A.; Grandjean, N. [ICMP, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

2014-09-15

We investigate the thermal stability of nearly lattice-matched InAlN layers under metal organic vapor phase epitaxy conditions for temperatures >800 °C and show that they are not fully stable. In particular, InAlN top layers undergo degradation during high temperature annealing due to a surface related process, which causes the loss of crystal quality. This strongly impacts the transport properties of InAlN/GaN HEMT heterostructures; in particular, the mobility is significantly reduced. However, we demonstrate that high thermal stability can be achieved by capping with a GaN layer as thin as 0.5 nm. Those findings enabled us to realize in situ passivated HEMT heterostructures with state of the art transport properties.

Development of procedures for spectrometer brand Spectral Products to capture spectra of incoherent optical radiation for the Laboratorio de Fotonica y Tecnologia Laser Aplicada

International Nuclear Information System (INIS)

Arias Avendano, Fabio Andres

2008-01-01

The procedure to capture spectra of incoherent optical radiation for the Laboratorio de Fotonica y Tecnologia Laser Aplicada (LAFTLA), of the Escuela de Ingenieria Electrica de la Universidad de Costa Rica is developed through the use of a spectrometer brand Spectral Products. The thorough understanding of manuals spectrometer brand Spectral Products was necessary for the satisfactory development of the project. Spectrometer and the card National Instruments are installed and run both devices with a montage of suitable laboratory. Two catches of spectrum for two different sources of optical radiation are performanced, since damages to the files .ddl precluded that the SM 240 spectrometer worked properly to take more catches to other sources of optical radiation. A final report containing the two catches is produced with the respective analysis. (author) [es

Historia de la psicología aplicada a la educación. ¿se reproducen las contradicciones o la dominación de clases?

Directory of Open Access Journals (Sweden)

Regina Helena De Freitas Campos

1989-12-01

Full Text Available En esta investigación se analizan tres aproximaciones diferentes a la interpretación de la historia de la psicología aplicada a la educación. Se presentan y evalúan las contribuciones de la teoría de la reproducción, de la teoría institucional y de la teoría del conflicto de clases para explicar el desarrollo de dos puntos de vista que compiten entre sí sobre la relación entre psicología y educación en Brasil. El artículo concluye afirmando que la teoría de conflicto de clases es el modelo que mejor ayuda a explicar la historia de la psicología educacional en el Brasil.

Electron density and currents of AlN/GaN high electron mobility transistors with thin GaN/AlN buffer layer

Energy Technology Data Exchange (ETDEWEB)

Bairamis, A.; Zervos, Ch.; Georgakilas, A., E-mail: alexandr@physics.uoc.gr [Microelectronics Research Group, IESL, Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1385, GR-71110 Heraklion, Crete (Greece); Department of Physics, University of Crete, P.O. Box 2208, GR-71003 Heraklion, Crete (Greece); Adikimenakis, A.; Kostopoulos, A.; Kayambaki, M.; Tsagaraki, K.; Konstantinidis, G. [Microelectronics Research Group, IESL, Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1385, GR-71110 Heraklion, Crete (Greece)

2014-09-15

AlN/GaN high electron mobility transistor (HEMT) structures with thin GaN/AlN buffer layer have been analyzed theoretically and experimentally, and the effects of the AlN barrier and GaN buffer layer thicknesses on two-dimensional electron gas (2DEG) density and transport properties have been evaluated. HEMT structures consisting of [300 nm GaN/ 200 nm AlN] buffer layer on sapphire were grown by plasma-assisted molecular beam epitaxy and exhibited a remarkable agreement with the theoretical calculations, suggesting a negligible influence of the crystalline defects that increase near the heteroepitaxial interface. The 2DEG density varied from 6.8 × 10{sup 12} to 2.1 × 10{sup 13} cm{sup −2} as the AlN barrier thickness increased from 2.2 to 4.5 nm, while a 4.5 nm AlN barrier would result to 3.1 × 10{sup 13} cm{sup −2} on a GaN buffer layer. The 3.0 nm AlN barrier structure exhibited the highest 2DEG mobility of 900 cm{sup 2}/Vs for a density of 1.3 × 10{sup 13} cm{sup −2}. The results were also confirmed by the performance of 1 μm gate-length transistors. The scaling of AlN barrier thickness from 1.5 nm to 4.5 nm could modify the drain-source saturation current, for zero gate-source voltage, from zero (normally off condition) to 0.63 A/mm. The maximum drain-source current was 1.1 A/mm for AlN barrier thickness of 3.0 nm and 3.7 nm, and the maximum extrinsic transconductance was 320 mS/mm for 3.0 nm AlN barrier.

Electron density and currents of AlN/GaN high electron mobility transistors with thin GaN/AlN buffer layer

International Nuclear Information System (INIS)

Bairamis, A.; Zervos, Ch.; Georgakilas, A.; Adikimenakis, A.; Kostopoulos, A.; Kayambaki, M.; Tsagaraki, K.; Konstantinidis, G.

2014-01-01

AlN/GaN high electron mobility transistor (HEMT) structures with thin GaN/AlN buffer layer have been analyzed theoretically and experimentally, and the effects of the AlN barrier and GaN buffer layer thicknesses on two-dimensional electron gas (2DEG) density and transport properties have been evaluated. HEMT structures consisting of [300 nm GaN/ 200 nm AlN] buffer layer on sapphire were grown by plasma-assisted molecular beam epitaxy and exhibited a remarkable agreement with the theoretical calculations, suggesting a negligible influence of the crystalline defects that increase near the heteroepitaxial interface. The 2DEG density varied from 6.8 × 10 12 to 2.1 × 10 13 cm −2 as the AlN barrier thickness increased from 2.2 to 4.5 nm, while a 4.5 nm AlN barrier would result to 3.1 × 10 13 cm −2 on a GaN buffer layer. The 3.0 nm AlN barrier structure exhibited the highest 2DEG mobility of 900 cm 2 /Vs for a density of 1.3 × 10 13 cm −2 . The results were also confirmed by the performance of 1 μm gate-length transistors. The scaling of AlN barrier thickness from 1.5 nm to 4.5 nm could modify the drain-source saturation current, for zero gate-source voltage, from zero (normally off condition) to 0.63 A/mm. The maximum drain-source current was 1.1 A/mm for AlN barrier thickness of 3.0 nm and 3.7 nm, and the maximum extrinsic transconductance was 320 mS/mm for 3.0 nm AlN barrier.

Análisis de la implementación de un modelo hidrodinámico tridimensional al flujo de un cauce natural

Directory of Open Access Journals (Sweden)

Santiago Aurelio Ochoa García

2017-04-01

Full Text Available En el análisis de la hidrodinámica fluvial están presentes una gran cantidad de variables, que al ser consideradas en la solución de las ecuaciones de estado describen el comportamiento del flujo. En este trabajo, se presenta la solución tridimensional de las ecuaciones de Navier Stokes promediadas por Reynolds con un modelo de cierre para la turbulencia K–ξ; solución aplicada en el flujo del río Tercero o Ctalamochita de la provincia de Córdoba, Argentina. La herramienta de cálculo para la solución de las ecuaciones de estado es el modelo SSIIM, un software libre orientado a la mecánica de fluidos computacional desarrollado en la Universidad Noruega de Ciencia y Tecnología. La importancia de analizar el flujo en forma tridimensional contrasta con la dificultad de su solución numérica, por lo que se ha descrito el algoritmo SIMPLE aplicado en este trabajo para la solución de las ecuaciones de estado.

Al-Qurû’ fi Al-Qur’an ‘Inda Al-Anbary fi Al-Adhdâd

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Raushani Azza

2018-03-01

Full Text Available This study examines about the term al-Qurû in the Qur’an. Al-Qurû is one of the most popular discussions among muslim scholars and mufasir, both in terms of language and fiqh. However, there is a bate among muslim scholar and mufasir about the meaning of al-Qurû. It’s because al-Qurû is one of the sentence of al-Adhdâd wich has two meaning, especially in the Qur’an, namely haid (menstruation and thahr. One of the most popular muslim scholar who concern in Qur’an and Arabic is al-Anbari with his book al-Adhdâd. Al-Anbari explains that Qurû has two meanings, First, al-Qurû in etymology is the form of Jama’ from aqra and qurû. Second, al-Qurû has a meaning of menstruation, thahr, or the period of iddah as a sign of being allowed to remarry after certain period of time.

Questões estratégicas aplicadas ao transporte marítimo internacional : como empresas dessa indústria devem inventar e interceptar o futuro?

OpenAIRE

Damianovic, Paulo Sergio

2010-01-01

Trata dos problemas que afetam o horizonte de lucratividade sustentável das empresas do setor de transporte marítimo internacional. Aborda conceitos de estratégia e modelos de negócios entrelaçando considerações sobre a atual realidade de seus resultados e ciecunstâncias externas. Aponta para oportunidades de transformação do modelo de negócios dessas empresas

Humidity dependence of molecular tunnel junctions with an AlOx/COOH- interface

Science.gov (United States)

Zhang, Xiaohang; McGill, Stephen; Xiong, Peng

2006-03-01

We have studied the electron transport in planar tunneling junctions with aluminum oxide and an organic self-assembled monolayer (SAM) as the tunnel barrier. The structure of the junctions is Al/AlOx/SAM/(Au, Pb) with a junction area of ˜ 0.4mm^2. The organic molecules investigated include mercaptohexadecanoic acid (MHA), hexadecanoic acid (HDA), and octadecyltrichlorosilane (OTS); all of which form ordered SAMs on top of aluminum oxide. The use of a superconducting electrode (Al) enables us to determine unambiguously that these are high-quality tunnel junctions. For junctions incorporating MHA, the transport behavior is found to be strongly humidity dependent. The resistance of these junctions drops more than 50% when placed in dry nitrogen and recovers when returned into the ambient. The same drop also occurs when the sample is placed into a vacuum, and backfilling the vacuum with either dry N2 or O2 has negligible effect on the resistance. For comparison, junctions with HDA show the same humidity dependence, while OTS samples do not. Since both MHA and HDA have carboxylic groups and OTS does not, the results suggest that water molecules at the AlOx/COOH- interface play the central role in the observed behavior. Inelastic tunneling spectroscopy (IETS) has also been performed to understand the role of water. This work was supported by a FSU Research Foundation PEG grant.

Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance.

Science.gov (United States)

Liu, Jiping; Magalhaes, Jurandir V; Shaff, Jon; Kochian, Leon V

2009-02-01

Aluminum-activated root malate and citrate exudation play an important role in plant Al tolerance. This paper characterizes AtMATE, a homolog of the recently discovered sorghum and barley Al-tolerance genes, shown here to encode an Al-activated citrate transporter in Arabidopsis. Together with the previously characterized Al-activated malate transporter, AtALMT1, this discovery allowed us to examine the relationship in the same species between members of the two gene families for which Al-tolerance genes have been identified. AtMATE is expressed primarily in roots and is induced by Al. An AtMATE T-DNA knockdown line exhibited very low AtMATE expression and Al-activated root citrate exudation was abolished. The AtALMT1 AtMATE double mutant lacked both Al-activated root malate and citrate exudation and showed greater Al sensitivity than the AtALMT1 mutant. Therefore, although AtALMT1 is a major contributor to Arabidopsis Al tolerance, AtMATE also makes a significant but smaller contribution. The expression patterns of AtALMT1 and AtMATE and the profiles of Al-activated root citrate and malate exudation are not affected by the presence or absence of the other gene. These results suggest that AtALMT1-mediated malate exudation and AtMATE-mediated citrate exudation evolved independently to confer Al tolerance in Arabidopsis. However, a link between regulation of expression of the two transporters in response to Al was identified through work on STOP1, a transcription factor that was previously shown to be necessary for AtALMT1 expression. Here we show that STOP1 is also required for AtMATE expression and Al-activated citrate exudation.

A new method to determine the 2DEG density distribution for passivated AlGaN/AlN/GaN heterostructure field-effect transistors

Science.gov (United States)

Fu, Chen; Lin, Zhaojun; Cui, Peng; Lv, Yuanjie; Zhou, Yang; Dai, Gang; Luan, Chongbiao; Liu, Huan; Cheng, Aijie

2018-01-01

A new method to determine the two-dimensional electron gas (2DEG) density distribution of the AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) after the Si3N4 passivation process has been presented. Detailed device characteristics were investigated and better transport properties have been observed for the passivated devices. The strain variation and the influence of the surface trapping states were analyzed. By using the polarization Coulomb field (PCF) scattering theory, the 2DEG density after passivation was both quantitively and qualitatively determined, which has been increased by 45% under the access regions and decreased by 2% under the gate region.

Volatile Transport on Pluto: First Results from the 2013 Observing Season

Science.gov (United States)

Buratti, B. J.; Dalba, P. A.; Hicks, M.; Chu, D.; O'Neill, A.; Chesley, J. P.

2013-12-01

With the New Horizons spacecraft due to encounter Pluto in slightly less than two years, close scrutiny of this dwarf ice planet has begun in earnest. Ground-based observations are especially critical for context and for a larger temporal excursion. Seasonal transport of volatiles should occur on Pluto, and this transport should be detectable through changes in its rotational light curve, once all variations due to viewing geometry have been modeled. Giving the steady increase observed in Pluto's atmospheric pressure over the past two decades, associated sublimation of frost from the surface has likely occurred, as predicted by volatile transport models. Rotational light curves of Pluto through time have been created for static frost models based on images from the Hubble Space Telescope. These models, which account for changes in viewing geometry, have been compared with observed light curves obtained between 1950 and 2013. No evidence for transport was evident prior to 2000. Observations from 2002 (Buie et al., 2010, Astron. J. 139, 1128) and 2007-2008 (Hicks et al. 2008, B.A.A.S. 40, 460) suggest changes in the frost pattern on Pluto's surface. New observations of Pluto's light curve from the 2013 season from Table Mountain Observatory show no evidence for the large transport of volatiles on Pluto's surface. Our data are the first measurement of a large opposition surge on Pluto similar to that seen on other icy bodies. Both Buie et al. (2010) and our observations from the 2012-2013 seasons show that Pluto is becoming more red in color. This observation makes sense if nitrogen is being removed from the surface to uncover a red, photolyzed substrate of methane. Funded by NASA.

Structural details of Al/Al 2O3 junctions and their role in the formation of electron tunnel barriers

Science.gov (United States)

Koberidze, M.; Puska, M. J.; Nieminen, R. M.

2018-05-01

We present a computational study of the adhesive and structural properties of the Al/Al 2O3 interfaces as building blocks of the metal-insulator-metal (MIM) tunnel devices, where electron transport is accomplished via tunneling mechanism through the sandwiched insulating barrier. The main goal of this paper is to understand, on the atomic scale, the role of the geometrical details in the formation of the tunnel barrier profiles. Initially, we concentrate on the adhesive properties of the interfaces. To provide reliable results, we carefully assess the accuracy of the traditional methods used to examine Al/Al 2O3 systems. These are the most widely employed exchange-correlation functionals—local-density approximation and two different generalized gradient approximations; the universal binding-energy relation for predicting equilibrium interfacial distances and adhesion energies; and the ideal work of separation as a measure of junction stability. In addition, we show that the established interpretation of the computed ideal work of separation might be misleading in predicting the optimal interface structures. Finally, we perform a detailed analysis of the atomic and interplanar relaxations in each junction, and identify their contributions to the tunnel barrier parameters. Our results imply that the structural irregularities on the surface of the Al film have a significant contribution to lowering the tunnel barrier height, while atomic relaxations at the interface and interplanar relaxations in Al2O3 may considerably change the width of the barrier and, thus, distort its uniformity. Both the effects may critically influence the performance of the MIM tunnel devices.

Transportation incidents involving Canadian shipments of radioactive material

International Nuclear Information System (INIS)

Jardine, J.M.

1979-06-01

This paper gives a brief statement of the legislation governing the transportation of radioactive materials in Canada, reviews the types of shipments made in Canada in 1977, and surveys the transportation incidents that have been reported to the Atomic Energy Control Board over the period 1947-1978. Some of the more significant incidents are described in detail. A totAl of 135 incidents occurred from 1947 to 1978, during which time there were 644750 shipments of radioactive material in Canada

El carácter híbrido de las dinámicas grupales online: del grupo de discusión al grupo focal

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Francisco Javier Parada Dueñas

2013-07-01

Full Text Available Este artículo reflexiona sobre formas de acceder a la realidad social a través del uso de metodologías de investigación online que tienen características híbridas. Primero se dan algunas claves para la construcción y ejecución de grupos de discusión en un contexto online. Una de las características centrales de esta técnica es su composición híbrida, moviéndose entre lo que sería un grupo de discusión y un grupo focal. El paso de la mediación a la conducción marca fuertemente la transición de una fase de grupos de discusión a una fase de grupo focal. Segundo, se reflexiona sobre Facebook y algunos posibles usos que se le puede dar a esta red social digital con la finalidad de llevar a cabo de mejor manera técnicas de investigación aplicadas al contexto online. En este sentido, se reflexiona sobre el avatar o perfil de Facebook en dos direcciones: para efectos de la composición muestral de un grupo de discusión online y como material que ayuda al análisis de las posiciones discursivas que tienen los sujetos estudiados.

Electrical transport characterization of Al and Sn doped Mg 2 Si thin films

KAUST Repository

Zhang, Bo; Zheng, Tao; Sun, Ce; Guo, Zaibing; Kim, Moon J.; Alshareef, Husam N.; Quevedo-Lopez, Manuel; Gnade, Bruce E.

2017-01-01

Thin-film Mg2Si was deposited using radio frequency (RF) magnetron sputtering. Al and Sn were incorporated as n-type dopants using co-sputtering to tune the thin-film electrical properties. X-ray diffraction (XRD) analysis confirmed

Al-Âyah al-Mutasyâbihât al-Lafzhiyyah fi Sûrah al-An’âm ‘Inda al-Kirmâny

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Hikmatiar Pasya

2017-07-01

Full Text Available This paper discusses about the verses of mutasyâbihât in the Quran. The debate of this verses caused various opinions. The meaning of the mutasyâbihât in this paper is the similarity and difference of the words in the Qur'an. Mufasir have different opinion about the meaning of the verse of mutasyâbihât al-lafdzi. In addition, many Hufadz of the Quran who are confused from one verse to another, or one chapter to another. It’s because similarity of verses in the Qur'an with other verses. So the writer wants to explain the verses mutasyâbihât al-lafdzi in the perspective of Hamzh al-Karmani in Surah al-An'âm. In this discussion the author discovers some passages in mutasyâbihât al-lafdzi, namely Asrâru al-balaghah fi mutasyabih al-lafdzi, Asrar al-balaghah fi mutasyabih al-hurf, and murâ'ah al-ikhtilâfmurâd bi al-lafdzi al-mukarrar.

Efeito de cargas aplicadas e profundidades de semeadura no desenvolvimento da cultura do feijão em sistema plantio direto Effect of loads applied and depths of sowing in the development of bean culture in no-tillage system

Directory of Open Access Journals (Sweden)

Alcir José Modolo

2010-06-01

Full Text Available Dentre os fatores primordiais para a germinação estão a umidade, a temperatura e a aeração do solo. É importante citar que esses fatores são diretamente influenciados pelo estado de compactação do solo ao redor da semente. Objetivou-se, neste trabalho, estudar os efeitos da combinação entre profundidades de semeadura e cargas aplicadas pela roda compactadora da semeadora-adubadora sobre o desenvolvimento da cultura do feijão, em sistema plantio direto. Foi utilizado o esquema fatorial no delineamento em blocos ao acaso, composto por doze tratamentos (três profundidades de semeadura e quatro níveis de cargas aplicadas pela roda compactadora e quatro repetições. Os resultados mostraram que a profundidade de semeadura influenciou, significativamente, o índice de velocidade de emergência, os estandes inicial e final de plantas e o rendimento da cultura. As diferentes cargas aplicadas pela roda compactadora não influenciaram significativamente as variáveis avaliadas.Among the primordial factors for the germination are humidity, temperature, and aeration of the soil. It is important to mention that these factors are directly influenced by the soil compaction state around the seed. The present paper had the aim of studying the effects of the combination between depths of sowing and loads applied by press wheel of the seeder upon the development of bean culture, in a no-tillage system. Factor schedule was applied to the delineation in random blocks composed by twelve treatments (three depths of sowing and four levels of loads applied by the press wheel and four replications. The results showed that depth of sowing significantly influenced the index of emergency speed, the initial and final stands of plants and yield of culture. The different loads applied for the press wheel did not significantly influence the evaluated variables.

Polymer Solar Cells with Efficiency >10% Enabled via a Facile Solution-Processed Al-Doped ZnO Electron Transporting Layer

KAUST Repository

Jagadamma, Lethy Krishnan

2015-04-22

A facile and low-temperature (125 °C) solution-processed Al-doped ZnO (AZO) buffer layer functioning very effectively as electron accepting/hole blocking layer for a wide range of polymer:fullerene bulk heterojunction systems, yielding power conversion efficiency in excess of 10% (8%) on glass (plastic) substrates is described. The ammonia-treatment of the aqueous AZO nanoparticle solution produces compact, crystalline, and smooth thin films, which retain the aluminum doping, and eliminates/reduces the native defects by nitrogen incorporation, making them good electron transporters and energetically matched with the fullerene acceptor. It is demonstrated that highly efficient solar cells can be achieved without the need for additional surface chemical modifications of the buffer layer, which is a common requirement for many metal oxide buffer layers to yield efficient solar cells. Also highly efficient solar cells are achieved with thick AZO films (>50 nm), highlighting the suitability of this material for roll-to-roll coating. Preliminary results on the applicability of AZO as electron injection layer in F8BT-based polymer light emitting diode are also presented. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Implementation of Solute Transport in the Vadose Zone into the `HYDRUS Package for MODFLOW'

Science.gov (United States)

Simunek, J.; Beegum, S.; Szymkiewicz, A.; Sudheer, K. P.

2017-12-01

The 'HYDRUS package for MODFLOW' was developed by Seo et al. (2007) and Twarakavi et al. (2008) to simultaneously evaluate transient water flow in both unsaturated and saturated zones. The package, which is based on the HYDRUS-1D model (Šimůnek et al., 2016) simulating unsaturated water flow in the vadose zone, was incorporated into MODFLOW (Harbaugh et al., 2000) simulating saturated groundwater flow. The HYDRUS package in the coupled model can be used to represent the effects of various unsaturated zone processes, including infiltration, evaporation, root water uptake, capillary rise, and recharge in homogeneous or layered soil profiles. The coupled model is effective in addressing spatially-variable saturated-unsaturated hydrological processes at the regional scale, allowing for complex layering in the unsaturated zone, spatially and temporarily variable water fluxes at the soil surface and in the root zone, and with alternating recharge and discharge fluxes (Twarakavi et al., 2008). One of the major limitations of the coupled model was that it could not be used to simulate at the same time solute transport. However, solute transport is highly dependent on water table fluctuations due to temporal and spatial variations in groundwater recharge. This is an important concern when the coupled model is used for analyzing groundwater contamination due to transport through the unsaturated zone. The objective of this study is to integrate the solute transport model (the solute transport part of HYDRUS-1D for the unsaturated zone and MT3DMS (Zheng and Wang, 1999; Zheng, 2009) for the saturated zone) into an existing coupled water flow model. The unsaturated zone component of the coupled model can consider solute transport involving many biogeochemical processes and reactions, including first-order degradation, volatilization, linear or nonlinear sorption, one-site kinetic sorption, two-site sorption, and two-kinetic sites sorption (Šimůnek and van Genuchten, 2008

Safety Analysis Report for Packaging (SARP): USA/5790/BLF (ERDA-AL) and USA/5791/BLF (ERDA-AL)

International Nuclear Information System (INIS)

Griffin, J.F.; Bertram, R.E.; Blauvelt, R.K.; Edling, D.A.; Flanagan, T.M.; Peterson, J.B.; Prosser, D.L.

1976-01-01

The Safety Analysis Report for Packaging (SARP) satisfies the request of the U. S. Energy Research and Development Administration for a formal safety analysis of the two insulated drum shipping containers identified as USA/5790/BLF ERDA-AL and USA/5791/BLF ERDA-AL. Discussions of structural integrity, thermal resistance, radiation shielding and radiological safety, nuclear criticality safety, and quality control are included. Much of the information was previously submitted to ERDA/OSD/ALO and the Department of Transportation (DOT) and provided the basis for obtaining special permits DOT-SP-5790 and DOT-SP-5791 as well as the Interim Certificates of Compliance until the SARP could be prepared. Complete physical and technical descriptions of the packages are presented. Each package consists of a modified DOT Specification 2R cylindrical steel inner container centered within an insulated steel drum. The contents may be any radioactive materials which satisfy the requirements established in this SARP. A shipment of Plutonium-238 in the form of a solid oxide is evaluated in this SARP as an example. The results of the nuclear criticality safety analysis show how much of the fissile isotopes may be shipped as Fissile Class I, II, or III for each container. Design and development considerations, the test and evaluations required to prove the ability of the containers to withstand normal transportation conditions, and the sequence of four hypothetical accident conditions (free drop, puncture, thermal, and water immersion) are discussed

Estudio y optimización de los sistemas de intercambio de calor en generación termoeléctrica aplicada al aprovechamiento del calor residual

OpenAIRE

Aranguren Garacochea, Patricia

2015-01-01

La presente tesis doctoral estudia el aprovechamiento del calor residual mediante generación termoeléctrica para la obtención de potencia eléctrica generada gracias al efecto Seebeck. Dos son las aproximaciones empleadas, la simulación computacional, empleando variables obtenidas experimentalmente y la experimentación de escenarios reales. Ambas dos han obtenido valores muy prometedores para la generación eléctrica a través de los gases residuales. Con el desarrollo de esta tesis doctoral,...

Oxidation process of AlOx-based magnetic tunnel junctions studied by photoconductance

NARCIS (Netherlands)

Koller, P.H.P.; Vanhelmont, F.W.M.; Boeve, H.; Lumens, P.G.E.; Jonge, de W.J.M.

2003-01-01

The oxidation process of Co/AlOx/Co magnetic tunnel junctions has been investigated by photoconductance, in addition to traditional transport measurements. The shape of the photoconductance curves is explained within the framework of a simple qualitative model, assuming an oxidation time dependent

Ética aplicada, interculturalidad y acción social

Directory of Open Access Journals (Sweden)

José Emilio Palacios Esteban

2014-04-01

Full Text Available Dentro de los objetivos de igualdad de género y justicia social que persigue el Ateneo citado y su compromiso de transferir internacional e interculturalmente los correspondientes resultados en conocimientos y experiencias, la inquietante actualidad en la que hoy vivimos los seres humanos nos exige abrir un espacio de razón pública, distinto al tradicional, orientado a la reflexión y práctica éticas. Es preciso garantizarlo tanto en los procesos de investigación como en su plasmación fáctica por parte de las instituciones y los agentes, profesionales o voluntarios, que ejercen la intervención social. Se trata, en efecto, de una responsabilidad que han de cumplir desde la nueva compresión que la complejidad de hoy día entiende mediante la expresión de “Ética Aplicada” (EA, la cual desplaza su centro de gravedad de los principios al contexto en el que viven las personas y suele plantearse en comités y grupos de discusión. Su caracterización en el presente escrito se condiciona a un doble momento, anterior y posterior a ella.

Wetting phenomena of Al-Cu alloys on sapphire below 800 deg. C

Energy Technology Data Exchange (ETDEWEB)

Klinter, Andreas J., E-mail: andreas.klinter@mail.mcgill.ca [Mining and Materials Engineering, McGill University, M.H. Wong Building, 3610 University Street, Montreal, QC, H3A 2B2 (Canada); Leon-Patino, Carlos A. [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, Apdo. Postal 888, CP 58000 Morelia, Michoacan (Mexico); Drew, Robin A.L. [Faculty of Engineering and Computer Science, Concordia University, 1455 Maisonneuve Blvd, EV 2.169, Montreal, QC, H3G 1M8 (Canada)

2010-02-15

Using a modified dispensed drop method, a decrease in contact angle on sapphire from pure aluminum to low-copper-containing Al alloys (7-12 wt.%) was found; with higher copper additions {theta} transitions to the non-wetting regime. Atomic force microscopy on long-term samples showed a significantly increased surface roughness beneath the drop. Using high-resolution transmission electron microscopy, the reaction product at the interface was identified as CuAl{sub 2}O{sub 4} for Al-7Cu and Al{sub 2}O{sub 3} for an Al-99.99 drop. X-ray photoelectron spectroscopy further confirmed the formation of CuAl{sub 2}O{sub 4} under CuAl{sub 2} drops. Spinel formation is caused by reaction of the alloy with residual oxygen in the furnace that is transported along the interface as modeled by thermodynamic simulations. The formation of CuAl{sub 2}O{sub 4} causes the reduced {sigma}{sub sl} and hence the improved wettability of sapphire by low-copper-containing alloys compared to pure aluminum. The main reason for the increase in {theta} with higher copper contents is the increasing {sigma}{sub lv} of the alloy.

Novel properties of the wheat aluminum tolerance organic acid transporter (TaALMT1) revealed by electrophysiological characterization in Xenopus Oocytes: functional and structural implications.

Science.gov (United States)

Piñeros, Miguel A; Cançado, Geraldo M A; Kochian, Leon V

2008-08-01

Many plant species avoid the phytotoxic effects of aluminum (Al) by exuding dicarboxylic and tricarboxylic acids that chelate and immobilize Al(3+) at the root surface, thus preventing it from entering root cells. Several novel genes that encode membrane transporters from the ALMT and MATE families recently were cloned and implicated in mediating the organic acid transport underlying this Al tolerance response. Given our limited understanding of the functional properties of ALMTs, in this study a detailed characterization of the transport properties of TaALMT1 (formerly named ALMT1) from wheat (Triticum aestivum) expressed in Xenopus laevis oocytes was conducted. The electrophysiological findings are as follows. Although the activity of TaALMT1 is highly dependent on the presence of extracellular Al(3+) (K(m1/2) of approximately 5 microm Al(3+) activity), TaALMT1 is functionally active and can mediate ion transport in the absence of extracellular Al(3+). The lack of change in the reversal potential (E(rev)) upon exposure to Al(3+) suggests that the "enhancement" of TaALMT1 malate transport by Al is not due to alteration in the transporter's selectivity properties but is solely due to increases in its anion permeability. The consistent shift in the direction of the E(rev) as the intracellular malate activity increases indicates that TaALMT1 is selective for the transport of malate over other anions. The estimated permeability ratio between malate and chloride varied between 1 and 30. However, the complex behavior of the E(rev) as the extracellular Cl(-) activity was varied indicates that this estimate can only be used as a general guide to understanding the relative affinity of TaALMT1 for malate, representing only an approximation of those expected under physiologically relevant ionic conditions. TaALMT1 can also mediate a large anion influx (i.e. outward currents). TaALMT1 is permeable not only to malate but also to other physiologically relevant anions such as Cl

Modeling of 1-D nitrate transport in single layer soils | Dike | Journal ...

African Journals Online (AJOL)

The transport of nitrate in laboratory single soil columns of sand, laterite and clay were investigated after 21 days. The 1-D contaminant transport model by Notodarmojo et al (1991) for single layer soils were calibrated and verified using field data collected from a refuse dump site at avu, owerri, Imo state. The experimental ...

Inter-machine validation study of neoclassical transport modelling in medium- to high-density stellarator-heliotron plasmas

International Nuclear Information System (INIS)

Dinklage, A.; Beidler, C.D.; Baldzuhn, J.; Feng, Y.; Geiger, J.; Jakubowski, M.; Maaßberg, H.; Yokoyama, M.; Tanaka, K.; Satake, S.; Ida, K.; Miyazawa, J.; Morisaki, T.; Velasco, J.L.; López-Bruna, D.; Ascasíbar, E.; Arévalo, J.; López-Fraguas, A.; Gates, D.; Isaev, M.

2013-01-01

A comparative study of energy transport for medium- to high-density discharges in the stellarator-heliotrons TJ-II, W7-AS and LHD is carried out. The specific discharge parameters are chosen to apply a recently concluded benchmarking study of neoclassical (NC) transport coefficients (Beidler et al 2011 Nucl. Fusion 51 076001) to perform this validation study. In contrast to previous experiments at low densities for which electron transport was predominant (Yokoyama et al 2007 Nucl. Fusion 47 1213), the current discharges also exhibit significant ion energy transport. As it affects the energy transport in 3D devices, the ambipolar radial electric field is addressed as well. For the discharges described, ion-root conditions, i.e. a small negative radial electric field were found. The energy transport in the peripheral region cannot be explained by NC theory. Within a ‘core region’(r/a < 1/2 ∼ 2/3), the predicted NC energy fluxes comply with experimental findings for W7-AS. For TJ-II, compliance in the core region is found for the particle transport and the electron energy transport. For the specific LHD discharges, the core energy transport complied with NC theory except for the electron energy transport in the inward-shifted magnetic configuration. The NC radial electric field tends to agree with experimental results for all devices but is measured to be more negative in the core of both LHD and TJ-II. As a general observation, the energy confinement time approaches the gyro-Bohm-type confinement scaling ISS04 (Yamada et al 2005 Nucl. Fusion 45 1684). This work is carried out within the International Stellarator-Heliotron Profile Database (www.ipp.mpg.de/ISS and http://ishpdb.nifs.ac.jp/index.html). (paper)

Petrographic al and mineralogical study of the sands of Al-Areen wildlife Sanctuary in the state of Bahrain

International Nuclear Information System (INIS)

Abu-Hussain, A. A

1998-01-01

Eileen sand covers about (8%) of Bahrain Island, and is concentrated in the western and southwestern regions of the Island as a thin s rip between the western coast and the cap rock, forming a distinguished ge morphologic feature on the Island. In the last few years, the area have suffered from sand from sand drifts which affected some of the important places in Bahrain as Al-Reen Wildlife sanctuary, alerting the spread of dentifrice's processes in new parts of the Island. The results showed that Al-Areen sand is composed mainly of quarts (68%) with lesser amounts of carbonates (15%) gypsum (12%), and heavy minerals. The compassion of Al-Areen sand with the surface sediments and rock exposure sin Bahrain, revealed that these sands have been drifting throughout the Quatenary period from the northwestern part of the Arabian peninsula peninsula by the northern wind (Shamal), prevailing at that time, transporting the quartzitic sand southeasted toward Bahrain. The influx of quartzitic sand to Bahrain was eliminated about 7000 year B.P. due to the ecstatic change of sea level in the Arabian Gulf which formed a natural water counter between Bahrain and the Arabian peninsula. Accordingly the sand drifts in Al-Areen Widife sanctuary is a result of diffraction's affecting the Island of Bahrain, this requires further studies to combat it. . (author). 25 refs., 5 figs. 2 tab

Determinación de restricciones y posibilidades ambientales para la expansion del transporte de gas natural en Colombia

Directory of Open Access Journals (Sweden)

Ángel Sanint Enrique

2011-11-01

Full Text Available En la línea de la Evaluación Ambiental Estratégica, EAE, se desarrolló un método para la determinación de restricciones y posibilidades ambientales en proyectos de transporte de gas natural por ductos, basado en el uso de herramientas de análisis territorial aplicadas sobre la plataforma SIG (Sistema de Información Geográfica, incorporando criterios ambientales que a escala 1:500.000 apoyarán la toma de decisiones en el nivel de planeación y propiciarán la elaboración del plan de expansión para el transporte de gas natural en Colombia. Para esto, se definió el concepto de ambiente a partir de un Modelo Analítico preexistente; se delimitó un área con posibilidades para la expansión de la red de transporte de gas natural incorporando nuevos trazados; se seleccionaron las variables y factores que complementaban el Modelo Analítico; se definió la estructura de preferencias a partir de una encuesta a expertos; se determinaron las restricciones nacionales y se construyeron superficies numéricas síntesis de critici dad ambiental para cada dimensión. Como resultado, se obtuvieron 5 superficies síntesis, una por cada dimensión, y una superficie final para Colombia, con restricciones y posibilidades ambientales. Además se propusieron análisis complementarios para establecer prioridades en la gestión ambiental.

Isotopically exchangeable Al in coastal lowland acid sulfate soils

Energy Technology Data Exchange (ETDEWEB)

Yvanes-Giuliani, Yliane A.M. [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia); Centre Européen de Recherche et d' Enseignement des Géosciences de l' Environnement, Aix-Marseille Université, Aix en Provence (France); Fink, D. [Centre Européen de Recherche et d' Enseignement des Géosciences de l' Environnement, Aix-Marseille Université, Aix en Provence (France); Rose, J. [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Waite, T. David [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia)

2016-01-15

Periodic discharges of high concentrations of aluminium (Al) causing fish kills and other adverse effects occur worldwide in waterways affected by coastal lowland acid sulfate soils (CLASS). The exchangeability — a metal's ability to readily transfer between the soil solid- and solution-phases — of Al in these soils is therefore of particular importance as it has implications for metal transport, plant availability and toxicity to living organisms. In the present study, the concentrations of isotopically exchangeable Al (E values) were measured in 27 CLASS and compared with common salt extractions (i.e. KCl and CuCl{sub 2}) used to estimate exchangeable soil pools of Al. E values of Al were high in the soils, ranging from 357 to 3040 mg·kg{sup −1}. Exchangeable concentrations estimated using 1 M KCl were consistently lower than measured E values, although a reasonable correlation was obtained between the two values (E = 1.68 × Al{sub KCl}, r{sup 2} = 0.66, n = 25). The addition of a 0.2 M CuCl{sub 2} extraction step improved the 1:1 agreement between extractable and isotopically exchangeable Al concentrations, but lead to significant mobilisation of non-isotopically exchangeable Al in surficial ‘organic-rich’ CLASS having E values < 1000 mg·kg{sup −1}. It was concluded that currently used (i.e. 1 M KCl) methodology severely underestimates exchangeable Al and total actual acidity values in CLASS and should be corrected by a factor similar to the one determined here. - Highlights: • Isotopically exchangeable Al was compared to 1 M KCl or 0.2 M CuCl{sub 2} extractable Al. • 1 M KCl always underestimated isotopically exchangeable Al concentrations. • 0.2 M CuCl{sub 2} mobilised non-isotopically exchangeable Al • 1 M KCl values require correction of ~ 1.7 to reflect exchangeable Al concentrations.

Drift-Scale Radionuclide Transport

International Nuclear Information System (INIS)

Houseworth, J.

2004-01-01

The purpose of this model report is to document the drift scale radionuclide transport model, taking into account the effects of emplacement drifts on flow and transport in the vicinity of the drift, which are not captured in the mountain-scale unsaturated zone (UZ) flow and transport models ''UZ Flow Models and Submodels'' (BSC 2004 [DIRS 169861]), ''Radionuclide Transport Models Under Ambient Conditions'' (BSC 2004 [DIRS 164500]), and ''Particle Tracking Model and Abstraction of Transport Process'' (BSC 2004 [DIRS 170041]). The drift scale radionuclide transport model is intended to be used as an alternative model for comparison with the engineered barrier system (EBS) radionuclide transport model ''EBS Radionuclide Transport Abstraction'' (BSC 2004 [DIRS 169868]). For that purpose, two alternative models have been developed for drift-scale radionuclide transport. One of the alternative models is a dual continuum flow and transport model called the drift shadow model. The effects of variations in the flow field and fracture-matrix interaction in the vicinity of a waste emplacement drift are investigated through sensitivity studies using the drift shadow model (Houseworth et al. 2003 [DIRS 164394]). In this model, the flow is significantly perturbed (reduced) beneath the waste emplacement drifts. However, comparisons of transport in this perturbed flow field with transport in an unperturbed flow field show similar results if the transport is initiated in the rock matrix. This has led to a second alternative model, called the fracture-matrix partitioning model, that focuses on the partitioning of radionuclide transport between the fractures and matrix upon exiting the waste emplacement drift. The fracture-matrix partitioning model computes the partitioning, between fractures and matrix, of diffusive radionuclide transport from the invert (for drifts without seepage) into the rock water. The invert is the structure constructed in a drift to provide the floor of the

The C9orf72 repeat expansion disrupts nucleocytoplasmic transport.

Science.gov (United States)

Zhang, Ke; Donnelly, Christopher J; Haeusler, Aaron R; Grima, Jonathan C; Machamer, James B; Steinwald, Peter; Daley, Elizabeth L; Miller, Sean J; Cunningham, Kathleen M; Vidensky, Svetlana; Gupta, Saksham; Thomas, Michael A; Hong, Ingie; Chiu, Shu-Ling; Huganir, Richard L; Ostrow, Lyle W; Matunis, Michael J; Wang, Jiou; Sattler, Rita; Lloyd, Thomas E; Rothstein, Jeffrey D

2015-09-03

The hexanucleotide repeat expansion (HRE) GGGGCC (G4C2) in C9orf72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Recent studies support an HRE RNA gain-of-function mechanism of neurotoxicity, and we previously identified protein interactors for the G4C2 RNA including RanGAP1. A candidate-based genetic screen in Drosophila expressing 30 G4C2 repeats identified RanGAP (Drosophila orthologue of human RanGAP1), a key regulator of nucleocytoplasmic transport, as a potent suppressor of neurodegeneration. Enhancing nuclear import or suppressing nuclear export of proteins also suppresses neurodegeneration. RanGAP physically interacts with HRE RNA and is mislocalized in HRE-expressing flies, neurons from C9orf72 ALS patient-derived induced pluripotent stem cells (iPSC-derived neurons), and in C9orf72 ALS patient brain tissue. Nuclear import is impaired as a result of HRE expression in the fly model and in C9orf72 iPSC-derived neurons, and these deficits are rescued by small molecules and antisense oligonucleotides targeting the HRE G-quadruplexes. Nucleocytoplasmic transport defects may be a fundamental pathway for ALS and FTD that is amenable to pharmacotherapeutic intervention.

Evaluación de un cosechador de café por vibración circular al tallo.

Directory of Open Access Journals (Sweden)

Ramírez V Carlos Mario

2003-06-01

Full Text Available Un prototipo para aplicar vibración circular al tallo del cafeto, desarrollado en el Centro Nacional de Investigaciones de Café CENICAFÉ, fue evaluado en campo para estudiar su factibilidad técnica en la cosecha mecanizada de café. La evaluación consistió en determinar el efecto de la frecuencia, excentricidad y punto de aplicación de la vibración circular en la selectividad y el rendimiento del desprendimiento de frutos de café. El análisis estadístico indicó que el mejor tratamiento para vibrar el tallo (chupón y tocón de la zoca del café corresponde a una frecuencia de excitación de 2000 c.p.m, con una excentricidad de 2,5 cm aplicada en el chupón, lográndose desprender hasta el 45% de los frutos maduros presentes en el árbol con un porcentaje de frutos verdes desprendidos de 27%. Se encontró como en otros trabajos previos que el desprendimiento de los frutos depende del incremento de la amplitud (mayor excentricidad y de la frecuencia de vibración. La selectividad de este desprendimiento depende también del porcentaje inicial de frutos maduros presentes en los árboles.

Fabrication of Nb{sub 3}Al superconducting wires by utilizing the mechanically alloyed Nb(Al){sub ss} supersaturated solid-solution with low-temperature annealing

Energy Technology Data Exchange (ETDEWEB)

Pan, X.F. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Yan, G., E-mail: gyan@c-nin.com [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Qi, M. [Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Cui, L.J. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Chen, Y.L.; Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity and New Energy R and D Center, Southwest Jiaotong University, Chengdu 610031 (China); Li, C.S. [Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Liu, X.H. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Feng, Y.; Zhang, P.X. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity and New Energy R and D Center, Southwest Jiaotong University, Chengdu 610031 (China); Liu, H.J. [Institute of Plasma Physics, Chinese Academy of Sciences (CAS), Hefei 230031 (China); and others

2014-07-15

Highlights: • This paper reported superconducting properties of the powder-in-tube Nb{sub 3}Al wires. • The Nb{sub 3}Al wires were made by using Nb(Al){sub ss} supersaturated solid solution powders. • The Cu-matrix Nb{sub 3}Al superconducting wires have been successfully fabricated. • The transport J{sub c} of Nb{sub 3}Al wires at 4.2 K, 10 T is up to 12,700 A/cm{sup 2}. - Abstract: High-performance Nb{sub 3}Al superconducting wire is a promising candidate to the application of high-field magnets. However, due to the production problem of km-grade wires that are free from low magnetic field instability, the Nb{sub 3}Al wires made by rapid heating, quenching and transformation (RHQT) are still not available to the large-scale engineering application. In this paper, we reported the properties of the in situ powder-in-tube (PIT) Nb{sub 3}Al superconducting wires, which were made by using the mechanically alloyed Nb(Al){sub ss} supersaturated solid solution, as well as the low temperature heat-treatment at 800 °C for 10 h. The results show that Nb{sub 3}Al superconductors in this method possess very fine grains and well superconducting properties, though a little of Nb{sub 2}Al and Nb impurities still keep being existence at present work. At the Nb{sub 3}Al with a nominal 26 at.% Al content, the onset T{sub c} reaches 15.8 K. Furthermore, a series of Nb{sub 3}Al wires and tapes with various sizes have been fabricated; for the 1.0 mm-diameter wire, the J{sub c} at 4.2 K, 10 T and 14 T have achieved 12,700 and 6900 A/cm{sup 2}, respectively. This work suggests it is possible to develop high-performance Cu-matrix Nb{sub 3}Al superconducting wires by directly using the Nb(Al){sub ss} supersaturated solid-solution without the complex RHQT heat-treatment process.

Dinámica demográfica y generación de viajes al trabajo en el AMCM: 1994-2000

Directory of Open Access Journals (Sweden)

Boris Graizbord

2005-01-01

Full Text Available Entre la vasta gama de problemas urbanos que afectan a la Ciudad de México es de vital importancia el transporte pues implica la movilidad de la población. Los diversos modos de transporte, públicos y privados, permiten acceder a los mercados urbanos, principalmente al de trabajo y al de vivienda, pero también a los mercados de bienes y servicios. Sin embargo, no se ha llevado a cabo un análisis a fondo de tales fenómenos conforme lo exigen los problemas, y a nuestro entender esto obedece a dos razones fundamentales: 1 la incipiente generación y escasa disponibilidad de datos que permitananalizar la estructura del transporte, y 2 la carencia de los elementos conceptuales necesarios para vincular el transporte con la dinámica de crecimiento de la metrópoli ycon el proceso de planificación de la ciudad. En este trabajo pretendemos avanzar en el análisis de la dinámica del transporte urbano de pasajeros en el Área Metropolitana de la Ciudad de México (AMCM. Lo haremos resaltando las diferencias absolutas y relativas en la generación de viajes rumbo al trabajo en dos momentos en el tiempo: 1994 y 2000. Esto nos brinda la posibilidad de acercarnos a una mayor comprensión de la dinámica de dos fenómenos,la ciudad y el transporte, y de apreciar así algunas relaciones entre ambos.

Melting of Au and Al in nanometer Fe/Au and Fe/Al multilayers under swift heavy ions: A thermal spike study

International Nuclear Information System (INIS)

Chettah, A.; Wang, Z.G.; Kac, M.; Kucal, H.; Meftah, A.; Toulemonde, M.

2006-01-01

Knowing that Fe is sensitive to swift heavy ion irradiations whereas Au and Al are not, the behavior of nanometric metallic multilayer systems, like [Fe(3 nm)/Au(x)] y and [Fe(3 nm)/Al(x)] y with x ranging between 1 and 10 nm, were studied within the inelastic thermal spike model. In addition to the usual cylindrical geometry of energy dissipation perpendicular to the ion projectile direction, the heat transport along the ion path was implemented in the electronic and atomic sub-systems. The simulations were performed using three different values of linear energy transfer corresponding to 3 MeV/u of 208 Pb, 132 Xe and 84 Kr ions. For the Fe/Au system, evidence of appearance of a molten phase was found in the entire Au layer, provided the Au thickness is less than 7 nm and 3 nm for Pb and Xe ions, respectively. For the Fe/Al(x) system irradiated with Pb ions, the Al layers with a thickness less than 4 nm melt along the entire ion track. Surprisingly, the Fe layer does not melt if the Al thickness is larger than 2 nm, although the deposited energy surpasses the electronic stopping power threshold of track formation in Fe. For Kr ions melting does not occur in any of the multilayer systems

On the pull: periplasmic trapping of sugars before transport.

Science.gov (United States)

Thomas, Gavin H

2017-06-01

Bacteria have evolved many routes for taking up nutrients, demonstrating great versatility in the types and mechanism of uptake used in different physiological conditions. The discovery of a single transporter in the bacterium Advenella mimigardefordensis for the uptake of five different sugars, including L-glucose and D-xylose, is described in this issue (Meinert et al., ), providing yet another example of the surprising adaptability of bacterial transport strategies. The transporter identified is a tripartite ATP-independent (TRAP) transporter, not previously associated with sugar transport, and in fact does not transport the sugars directly at all, rather requiring them to be converted in the periplasm to their respective sugar acid forms before transport through what appears to be a novel general sugar acid transporter. In this commentary, I describe how this process is consistent with the known mechanisms of TRAP transporters and consider how the role of sugar oxidation, or oxidative fermentation, operates with multiple hexose and pentose sugars. Finally I suggest that the periplasmic conversion of nutrients acquired across the outer membrane, before transport across the inner membrane, could have potentially useful biological functions in Gram negative bacteria. © 2017 John Wiley & Sons Ltd.

Diffusion-induced quadrupole relaxation of 27Al nuclei in dilute Al-Ti, Al-Cr, Al-Mn, and Al-Cu alloys at high temperatures

International Nuclear Information System (INIS)

Bottyan, L.; Beke, D.L.; Tompa, K.

1983-01-01

The temperature dependence of the laboratory frame spin-lattice relaxation time of 27 Al nuclei is measured in 5N Al and in dilute Al-Ti, Al-Cr, Al-Mn, and Al-Cu alloys at 5.7 and 9.7 MHz resonance frequencies. The relaxation in pure aluminium is found to be purely due to the conduction electrons. An excess T 1 -relaxation contribution is detected in all Al-3d alloys investigated above 670 K. The excess relaxation rate is proportional to the impurity content and the temperature dependence of the excess contribution is of Arrhenius-type with an activation energy of (1.3 +- 0.3) eV for all of the investigated alloys. The relaxation contribution is found to be quadrupolar in origin and is caused by the relative diffusional jumps of solute atoms and Al atoms relatively far from the impurity. (author)

Interface electron structure of Fe3Al/TiC composites

Institute of Scientific and Technical Information of China (English)

PANG Lai-xue; SUN Kang-ning; SUN Jia-tao; FAN Run-hua; REN Shuai

2006-01-01

Based on YU's solids and molecules emperical electron theory(EET), interface valence electron structure of TiC-Fe3Al composites was set up, and the valence electron density of different atomic states TiC and Fe3Al composites in various planes was determined. The results indicate that the electron density of (100)Fe3Al is consistent with that of (110)TiC in the first-class approximation, the absolute value of minimum electron density difference along the interface is 0.007 37 nm-2, and the relative value is 0.759%. (110)TiC//(100)Fe3Al preferred orientation is believed to benefit the formation of the cuboidal shape TiC. In the other hand, it shows that the particle growth is accompanied by the transport of electron, the deviation continuity of electron density intrinsically hinders the grain growth. The electron density of (100)TiC is not consistent with Fe3Al arbitrary crystallographic plane,thus it well explains that the increased titanium and carbon contents do not increase the size of large particles. The crystallographic orientation of (110)TiC//(100)FeAl will improve the mechanical properties. Therefore interface electron theory is an effective theoretical implement for designing excellent property of composites.

Structural instability and photoacoustic study of AlSb prepared by mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Triches, D.M.; Souza, S.M.; Poffo, C.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Lima, J.C. de, E-mail: fsc1jcd@fsc.ufsc.b [Departamento de Fisica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Grandi, T.A. [Departamento de Fisica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Biasi, R.S. de [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil)

2010-09-03

High-purity elemental Al and Sb powders were blended with equiatomic composition and submitted to mechanical alloying. For all milling times, the milled powders showed a mixture of AlSb and elemental Sb. The largest amount of AlSb was reached for milling times between 7 and 10 h. For milling times larger than 10 h, decomposition of AlSb was observed. The volume fractions of the crystalline and interfacial components were estimated using the X-ray diffraction pattern of a sample milled for 10 h. Photoacoustic absorption spectroscopy (PAS) was used to determine the thermal diffusivity and other heat transport parameters in the same sample. A combination of XRD and PAS data was used to estimate the thermal diffusivity of the interfacial component, which has a significant contribution to the thermal diffusivity of the sample.

Structural instability and photoacoustic study of AlSb prepared by mechanical alloying

International Nuclear Information System (INIS)

Triches, D.M.; Souza, S.M.; Poffo, C.M.; Lima, J.C. de; Grandi, T.A.; Biasi, R.S. de

2010-01-01

High-purity elemental Al and Sb powders were blended with equiatomic composition and submitted to mechanical alloying. For all milling times, the milled powders showed a mixture of AlSb and elemental Sb. The largest amount of AlSb was reached for milling times between 7 and 10 h. For milling times larger than 10 h, decomposition of AlSb was observed. The volume fractions of the crystalline and interfacial components were estimated using the X-ray diffraction pattern of a sample milled for 10 h. Photoacoustic absorption spectroscopy (PAS) was used to determine the thermal diffusivity and other heat transport parameters in the same sample. A combination of XRD and PAS data was used to estimate the thermal diffusivity of the interfacial component, which has a significant contribution to the thermal diffusivity of the sample.

Interfacial phenomena in the reactions of Al-B, Al-Ti-B, and Al-Zr-B alloys with KF-AlF3 and NaF-AlF3 melts

International Nuclear Information System (INIS)

Lee, M.S.; Terry, B.S.; Grieveson, P.

1993-01-01

The interfacial phenomena occurring during the contacting of liquid Al-B, Al-Ti-B, and Al-Zr-B melts with KF-AlF 3 liquid fluxes have been investigated by optical examination of quenched metal drops previously immersed in the liquid fluxes. Reactions in the Al-B/KF-AlF 3 system involve the formation of metastable AlB 12 at the metal/flux interface. At high KBF 4 levels in the flux, the AlB 12 is dispersed in the flux and also at low KBF 4 levels in the metal. Reactions in the Al-Ti-B/KF-AlF 3 system involve the formation of TiB 2 , which may be dispersed in either the metal or the flux depending upon the composition of the flux. The results obtained for the Al-Ti-B/NaF-AlF 3 and Al-Zr-B/KF-AlF 3 systems were similar to those observed for the Al-Ti-B/KF-AlF 3 system

Ferromagnetic quantum criticality in the uranium-based ternary compounds URhSi, URhAl, and UCoAl

International Nuclear Information System (INIS)

Combier, Tristan

2014-01-01

In this thesis we explore the ferromagnetic quantum criticality in three uranium-based ternary compounds, by means of thermodynamical and transport measurements on single crystal samples, at low temperature and high pressure. URhSi and URhAl are itinerant ferromagnets, while UCoAl is a paramagnet being close to a ferromagnetic instability. All of them have Ising-type magnetic ordering. In the orthorhombic compound URhSi, we show that the Curie temperature decreases upon applying a magnetic field perpendicular to the easy magnetization axis, and a quantum phase transition is expected around 40 T. In the hexagonal system URhAl, we establish the pressure-temperature phase diagram for the first time, indicating a quantum phase transition around 5 GPa. In the isostructural compound UCoAl, we investigate the metamagnetic transition with measurements of magnetization, Hall effect, resistivity and X-ray magnetic circular dichroism. Some intriguing magnetic relaxation phenomena are observed, with step-like features. Hall effect and resistivity have been measured at dilution temperatures, under hydrostatic pressure up to 2.2 GPa and magnetic field up to 16 T. The metamagnetic transition terminates under pressure and magnetic field at a quantum critical endpoint. In this region, a strong effective mass enhancement occurs, and an intriguing difference between up and down field sweeps appears in transverse resistivity. This may be the signature of a new phase, supposedly linked to the relaxation phenomena observed in magnetic measurements, arising from frustration on the quasi-Kagome lattice of uranium atoms in this crystal structure. (author) [fr

Photonuclear Physics in Radiation Transport - II: Implementation

International Nuclear Information System (INIS)

White, M.C.; Little, R.C.; Chadwick, M.B.; Young, P.G.; MacFarlane, R.E.

2003-01-01

This is the second of two companion papers. The first paper describes model calculations and nuclear data evaluations of photonuclear reactions on isotopes of C, O, Al, Si, Ca, Fe, Cu, Ta, W, and Pb for incident photon energies up to 150 MeV. This paper describes the steps taken to process these files into transport libraries and to update the Monte Carlo N-Particle (MCNP) and MCNPX radiation transport codes to use tabular photonuclear reaction data. The evaluated photonuclear data files are created in the standard evaluated nuclear data file (ENDF) format. These files must be processed by the NJOY data processing system into A Compact ENDF (ACE) files suitable for radiation transport calculations. MCNP and MCNPX have been modified to use these new data in a self-consistent and fully integrated manner. Verification problems were used at each step along the path to check the integrity of the methodology. The resulting methodology and tools provide a comprehensive system for using photonuclear data in radiation transport calculations. Also described are initial validation simulations used to benchmark several of the photonuclear transport tables

A domain-based approach for analyzing the function of aluminum-activated malate transporters from wheat (Triticum aestivum) and Arabidopsis thaliana in Xenopus oocytes.

Science.gov (United States)

Sasaki, Takayuki; Tsuchiya, Yoshiyuki; Ariyoshi, Michiyo; Ryan, Peter R; Furuichi, Takuya; Yamamoto, Yoko

2014-12-01

Wheat and Arabidopsis plants respond to aluminum (Al) ions by releasing malate from their root apices via Al-activated malate transporter. Malate anions bind with the toxic Al ions and contribute to the Al tolerance of these species. The genes encoding the transporters in wheat and Arabidopsis, TaALMT1 and AtALMT1, respectively, were expressed in Xenopus laevis oocytes and characterized electrophysiologically using the two-electrode voltage clamp system. The Al-activated currents generated by malate efflux were detected for TaALMT1 but not for AtALMT1. Chimeric proteins were generated by swapping the N- and C-terminal halves of TaALMT1 and AtALMT1 (Ta::At and At::Ta). When these chimeras were characterized in oocytes, Al-activated malate efflux was detected for the Ta::At chimera but not for At::Ta, suggesting that the N-terminal half of TaALMT1 is necessary for function in oocytes. An additional chimera, Ta(48)::At, generated by swapping 17 residues from the N-terminus of AtALMT1 with the equivalent 48 residues from TaALMT1, was sufficient to support transport activity. This 48 residue region includes a helical region with a putative transmembrane domain which is absent in AtALMT1. The deletion of this domain from Ta(48)::At led to the complete loss of transport activity. Furthermore, truncations and a deletion at the C-terminal end of TaALMT1 indicated that a putative helical structure in this region was also required for transport function. This study provides insights into the structure-function relationships of Al-activated ALMT proteins by identifying specific domains on the N- and C-termini of TaALMT1 that are critical for basal transport function and Al responsiveness in oocytes. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Reduced Gravity Studies of Soret Transport Effects in Liquid Fuel Combustion

Science.gov (United States)

Shaw, Benjamin D.

2004-01-01

Soret transport, which is mass transport driven by thermal gradients, can be important in practical flames as well as laboratory flames by influencing transport of low molecular weight species (e.g., monatomic and diatomic hydrogen). In addition, gas-phase Soret transport of high molecular weight fuel species that are present in practical liquid fuels (e.g., octane or methanol) can be significant in practical flames (Rosner et al., 2000; Dakhlia et al., 2002) and in high pressure droplet evaporation (Curtis and Farrell, 1992), and it has also been shown that Soret transport effects can be important in determining oxygen diffusion rates in certain classes of microgravity droplet combustion experiments (Aharon and Shaw, 1998). It is thus useful to obtain information on flames under conditions where Soret effects can be clearly observed. This research is concerned with investigating effects of Soret transport on combustion of liquid fuels, in particular liquid fuel droplets. Reduced-gravity is employed to provide an ideal (spherically-symmetrical) experimental model with which to investigate effects of Soret transport on combustion. The research will involve performing reduced-gravity experiments on combustion of liquid fuel droplets in environments where Soret effects significantly influence transport of fuel and oxygen to flame zones. Experiments will also be performed where Soret effects are not expected to be important. Droplets initially in the 0.5 to 1 mm size range will be burned. Data will be obtained on influences of Soret transport on combustion characteristics (e.g., droplet burning rates, droplet lifetimes, gas-phase extinction, and transient flame behaviors) under simplified geometrical conditions that are most amenable to theoretical modeling (i.e., spherical symmetry). The experiments will be compared with existing theoretical models as well as new models that will be developed. Normal gravity experiments will also be performed.

Modelo matemático de tipo valor medio de un motor de combustión interna y estimación de estados usando técnicas Bayesianas

OpenAIRE

Hernández Lordui, Mónica Patricia

2013-01-01

En el presente trabajo se obtiene el modelo matemático orientado al control de un motor de combustión interna de ignición por chispa. El modelo aplica ecuaciones de primeros principios con no-linealidades y parámetros desconocidos. Las ecuaciones aplicadas al modelo están explicadas mediante relaciones termodinámicas conocidas en la literatura como \\Mean Value Engine Modelling" (MVEM). La MVEM describe un modelo matemático orientado al control para las máquinas de combustión interna de ignici...

Self-consistent gyrokinetic modeling of neoclassical and turbulent impurity transport

OpenAIRE

Estève , D. ,; Sarazin , Y.; Garbet , X.; Grandgirard , V.; Breton , S. ,; Donnel , P. ,; Asahi , Y. ,; Bourdelle , C.; Dif-Pradalier , G; Ehrlacher , C.; Emeriau , C.; Ghendrih , Ph; Gillot , C.; Latu , G.; Passeron , C.

2018-01-01

International audience; Trace impurity transport is studied with the flux-driven gyrokinetic GYSELA code [V. Grandgirard et al., Comp. Phys. Commun. 207, 35 (2016)]. A reduced and linearized multi-species collision operator has been recently implemented, so that both neoclassical and turbulent transport channels can be treated self-consistently on an equal footing. In the Pfirsch-Schlüter regime likely relevant for tungsten, the standard expression of the neoclassical impurity flux is shown t...

Seasonal Transport in Mars' Mesosphere-Thermosphere revealed by Nitric Oxide nightglow

Science.gov (United States)

Royer, E. M.; Stiepen, A.; Schneider, N. M.; Jain, S.; Milby, Z.; Deighan, J.; Gonzalez-Galindo, F.; Bougher, S. W.; Gerard, J. C. M. C.; Stevens, M. H.; Evans, J. S.; Stewart, I. F.; Chaffin, M.; McClintock, B.; Clarke, J. T.; Montmessin, F.; Holsclaw, G.; Lefèvre, F.; Forget, F.; Lo, D.; Hubert, B. A.; Jakosky, B. M.

2017-12-01

We analyze the ultraviolet nightglow in the atmosphere of Mars through the Nitric Oxide (NO) δ and γ band emissions observed by the Imaging Ultraviolet Spectrograph (IUVS, McClintock et al., 2015) when the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft is at apoapsis and periapsis. On the dayside thermosphere of Mars, solar extreme ultraviolet radiation dissociates CO2 and N2 molecules. O(3P) and N(4S) atoms are carried by the day-to-night hemispheric transport. They descend in the nightside mesosphere, where they can radiatively recombine to form NO(C2Π). The excited molecules rapidly relax by emitting UV photons in the δ and γ bands. These emissions are thus indicators of the N and O atom fluxes transported from the dayside to Mars' nightside and the descending circulation pattern from the nightside thermosphere to the mesosphere (e.g. Bertaux et al., 2005 ; Bougher et al., 1990 ; Cox et al., 2008 ; Gagné et al., 2013 ; Gérard et al., 2008 ; Stiepen et al., 2015, 2017). A large dataset of nightside disk images and vertical limb scans during southern winter, fall equinox and southern summer conditions have been accumulated since the beginning of the mission. We will present a discussion regarding the variability of the brightness and altitude of the emission with season, geographical position (longitude) and local time and possible interpretation for local and global changes in the mesosphere dynamics. We show the possible impact of atmospheric waves structuring the emission longitudinally and indicating a wave-3 structure in Mars' nightside mesosphere. Quantitative comparison with calculations from the LMD-MGCM (Laboratoire de Météorologie Dynamique-Mars Global Climate Model) show that the model globally reproduces the trends of the NO nightglow emission and its seasonal variation but also indicates large discrepancies (up to a factor 50 fainter in the model) suggesting that the predicted transport is too efficient toward the night winter pole

Synthesizing (ZrAl3 + AlN)/Mg-Al composites by a 'matrix exchange' method

Science.gov (United States)

Gao, Tong; Li, Zengqiang; Hu, Kaiqi; Han, Mengxia; Liu, Xiangfa

2018-06-01

A method named 'matrix exchange' to synthesize ZrAl3 and AlN reinforced Mg-Al composite was developed in this paper. By inserting Al-10ZrN master alloy into Mg matrix and reheating the cooled ingot to 550 °C, Al and Mg atoms diffuse to the opposite side. As a result, liquid melt occurs once the interface areas reach to proper compositions. Then dissolved Al atoms react with ZrN, leading to the in-situ formation of ZrAl3 and AlN particles, while the Al matrix is finally replaced by Mg. This study provides a new insight for preparing Mg composites.

Enhancing Transportation Education Using Mobile Devices and Applications

Science.gov (United States)

Gallup, Jennifer; Lamothe, Saron N.; Gallup, Adam

2015-01-01

The most salient aspect of independent living and successful post-high school transition to employment is having the ability to independently use transportation. Adolescents and young adults with disabilities continue to experience significantly lower employment rates than their peers without disabilities (Wagner et al., 2003). One way to support…

Human behavior research and the design of sustainable transport systems

Science.gov (United States)

Schauer, James J.

2011-09-01

reduced carbon emissions are central to the design and optimization of future low carbon transport systems. Gaker et al (2011) suggest a framework, and provide insight into the willingness of transport consumers to pay for emission reductions of carbon dioxide from their personal transport choices within the context of other attributes of transport variables. The results of this study, although limited to a small demographic segment of the US population, demonstrate that people can integrate information on greenhouse gas emissions with other transport attributes including cost and time. Likewise, the research shows that the study group was willing to pay for reduction in greenhouse gas emissions associated with their transport choices. The study examined auto purchase choice, transport mode choice and transport route choice, which represent key decisions associated with transport that impact greenhouse gas emissions. Interestingly, they found that the study group was willing to pay for reductions in greenhouse gas emissions at a relatively consistent price across these transport choices. Clearly, the study results may not broadly apply to all demographics of users of transport, even in the study domain, due to the small demographic segment that was examined and the fact that the study was conducted in the laboratory. However, the methods used by Gaker et al (2011) are cause for optimism that future studies can obtain much needed mapping of transport preferences and willingness to pay for greenhouse gas emission reductions associated with personal transport choices. Although the Gaker et al (2011) study is directed at understanding the promotion of low carbon transport in the context of existing infrastructures, the ability of these studies to elucidate human behavior and preferences within the trade-offs of transport are critical to the design of future transport systems that seek to meet transport demand with constrained greenhouse gas emissions. Additional studies of

Coupled growth of Al-Al2Cu eutectics in Al-Cu-Ag alloys

International Nuclear Information System (INIS)

Hecht, U; Witusiewicz, V; Drevermann, A

2012-01-01

Coupled eutectic growth of Al and Al 2 Cu was investigated in univariant Al-Cu-Ag alloys during solidification with planar and cellular morphology. Experiments reveal the dynamic selection of small spacings, below the minimum undercooling spacing and show that distinct morphological features pertain to nearly isotropic or anisotropic Al-Al 2 Cu interfaces.

AL ITTIJAHAT AL MUNHARIFAH FI AT TAFSIR LI BADLI ASHAB AL MADZAHIB AL NAHWIYYAH WA BADL MAN YAJHALUNA QAWAID AL LUGHAH AL ARABIYYAH FI NADHAR MUHAMMAD HUSAIN AL DZAHABIY

Directory of Open Access Journals (Sweden)

Misbakhudin Misbakhudin

2017-06-01

Full Text Available One of the most precious achievement in qur’anic studies was the book of Al-Ittijâhât al-Munharifah fî al-Tafsîr: Dawâfi’uha wa Daf’uha written by A great Islamic scholar, Muhammad Husein al-Dzahabî. He was succeeded in discussing several issues of corruptions of the exegesis of the holy Qur’an. This article is aimed to explain and to describe his analysis toward several corrupted linguist interpretations in their originations and such corrupted linguistic interpretations of the holy Qur’an which are ignoring Arabic structures and grammers

Effects of varying the step particle distribution on a probabilistic transport model

International Nuclear Information System (INIS)

Bouzat, S.; Farengo, R.

2005-01-01

The consequences of varying the step particle distribution on a probabilistic transport model, which captures the basic features of transport in plasmas and was recently introduced in Ref. 1 [B. Ph. van Milligen et al., Phys. Plasmas 11, 2272 (2004)], are studied. Different superdiffusive transport mechanisms generated by a family of distributions with algebraic decays (Tsallis distributions) are considered. It is observed that the possibility of changing the superdiffusive transport mechanism improves the flexibility of the model for describing different situations. The use of the model to describe the low (L) and high (H) confinement modes is also analyzed

Novel Properties of the Wheat Aluminum Tolerance Organic Acid Transporter (TaALMT1) Revealed by Electrophysiological Characterization in Xenopus Oocytes: Functional and Structural Implications1[OA

Science.gov (United States)

Piñeros, Miguel A.; Cançado, Geraldo M.A.; Kochian, Leon V.

2008-01-01

Many plant species avoid the phytotoxic effects of aluminum (Al) by exuding dicarboxylic and tricarboxylic acids that chelate and immobilize Al3+ at the root surface, thus preventing it from entering root cells. Several novel genes that encode membrane transporters from the ALMT and MATE families recently were cloned and implicated in mediating the organic acid transport underlying this Al tolerance response. Given our limited understanding of the functional properties of ALMTs, in this study a detailed characterization of the transport properties of TaALMT1 (formerly named ALMT1) from wheat (Triticum aestivum) expressed in Xenopus laevis oocytes was conducted. The electrophysiological findings are as follows. Although the activity of TaALMT1 is highly dependent on the presence of extracellular Al3+ (Km1/2 of approximately 5 μm Al3+ activity), TaALMT1 is functionally active and can mediate ion transport in the absence of extracellular Al3+. The lack of change in the reversal potential (Erev) upon exposure to Al3+ suggests that the “enhancement” of TaALMT1 malate transport by Al is not due to alteration in the transporter's selectivity properties but is solely due to increases in its anion permeability. The consistent shift in the direction of the Erev as the intracellular malate activity increases indicates that TaALMT1 is selective for the transport of malate over other anions. The estimated permeability ratio between malate and chloride varied between 1 and 30. However, the complex behavior of the Erev as the extracellular Cl− activity was varied indicates that this estimate can only be used as a general guide to understanding the relative affinity of TaALMT1 for malate, representing only an approximation of those expected under physiologically relevant ionic conditions. TaALMT1 can also mediate a large anion influx (i.e. outward currents). TaALMT1 is permeable not only to malate but also to other physiologically relevant anions such as Cl−, NO3−, and

Emission Depth Distribution Function of Al 2s Photoelectrons in Al2O3

Science.gov (United States)

Hucek, S.; Zemek, J.; Jablonski, A.; Tilinin, I. S.

The escape probability of Al 2s photoelectrons leaving an aluminum oxide sample (Al2O3) has been studied as a function of depth of origin. It has been found that the escape probability (the so-called emission depth distribution function - DDF) depends strongly on the photoelectron emission direction with respect to that of the incident X-ray beam. In particular, in the emission direction close to that of photon propagation, the DDF differs substantially from the simple Beer-Lambert law and exhibits a nonmonotonic behavior with a maximum in the near-surface region at a depth of about 10 Å. Experimental results are in good agreement with theoretical predictions based on Monte Carlo simulations of the electron transport and with analytical solution of the linearized Boltzmann kinetic equation with appropriate boundary conditions. Both theoretical approaches take into account multiple elastic scattering of photoelectrons on their way out of the sample. It is shown that the commonly used straight line approximation (SLA), which neglects elastic scattering effects, fails to describe adequately experimental data at emission directions close to minima of the differential photoelectric cross section.

Extended analysis of the frequency dependence of the admittance of MIS structures with pulsed-laser-deposited AlN films

Energy Technology Data Exchange (ETDEWEB)

Simeonov, S; Bakalova, S; Szekeres, A; Kafedjiijska, E [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Grigorescu, S; Socol, G; Mihailescu, I N [Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-54, RO-77125, Bucharest-Magurele (Romania)], E-mail: sbakalova@issp.bas.bg

2008-05-01

MIS structures with AlN films deposited on p-Si by pulsed laser deposition were prepared and admittance measurements were carried out in the frequency range of 100 Hz - 10 MHz. The density of traps in the AlN film and at the AlN/Si interface was evaluated using the electrical characteristics obtained, and the hopping mechanism of charge transport was determined from the dispersion of the a.c. conductance.

Cosmic-Ray Transport in Heliospheric Magnetic Structures. II. Modeling Particle Transport through Corotating Interaction Regions

Energy Technology Data Exchange (ETDEWEB)

Kopp, Andreas [Université Libre de Bruxelles, Service de Physique Statistique et des Plasmas, CP 231, B-1050 Brussels (Belgium); Wiengarten, Tobias; Fichtner, Horst [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Effenberger, Frederic [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Kühl, Patrick; Heber, Bernd [Institut für Experimentelle und Angewandte Physik, Christian-Albrecht-Universität zu Kiel, D-24098 Kiel (Germany); Raath, Jan-Louis; Potgieter, Marius S. [Centre for Space Research, North-West University, 2520 Potchefstroom (South Africa)

2017-03-01

The transport of cosmic rays (CRs) in the heliosphere is determined by the properties of the solar wind plasma. The heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric CR transport are structures such as corotating interaction regions (CIRs), which, due to the enhancement of the magnetic field strength and magnetic fluctuations within and due to the associated shocks as well as stream interfaces, do influence the CR diffusion and drift. In a three-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with the numerical magnetohydrodynamic (MHD) framework Cronos (Wiengarten et al., referred as Paper I), and the results serve as input to a transport code employing a stochastic differential equation approach (this paper). While, in Paper I, we presented results from 3D simulations with Cronos, the MHD output is now taken as an input to the CR transport modeling. We discuss the diffusion and drift behavior of Galactic cosmic rays using the example of different theories, and study the effects of CIRs on these transport processes. In particular, we point out the wide range of possible particle fluxes at a given point in space resulting from these different theories. The restriction of this variety by fitting the numerical results to spacecraft data will be the subject of the third paper of this series.

Supercurrent and quasi-particle transport in a two-dimensional electron gas with superconducting electrodes

NARCIS (Netherlands)

vanWees, BJ

1996-01-01

We have investigated supercurrent and quasi-particle transport in the 2DEG present in InAs/Al(Ga)Sb quantum wells. The physics of these systems will be discussed with two examples: (i) supercurrent transport in Nb/InAs/Nb junctions, and (ii) phase-dependent resistance in a superconductor-2DEG

Emissão de CO2 do transporte da madeira nativa da Amazônia

Directory of Open Access Journals (Sweden)

Érica Ferraz Campos

Full Text Available A madeira aplicada à construção é considerada um estoque de carbono. O transporte na cadeia produtiva da madeira implica em emissão de CO2, reduzindo seu estoque líquido. Com base nos dados de 2007 do IBAMA sobre origem, destino e volume de madeira serrada amazônica transportada nacionalmente, a distância média percorrida foi estimada em 1.956km. Fatores de consumo de diesel entre 0,005L/t.km e 0,017L/t.km, equivalentes a fatores de emissão de 12,8gCO2/t.km a 50,6gCO2/t.km, foram identificados em literatura e levantamentos realizados neste estudo. Para quantificar a emissão de CO2, foram analisados quatro modelos de veículos, com diferentes capacidades de carga. A influência da densidade da madeira determinou uma variabilidade de até 210% no resultado final; o peso próprio do veículo, de 30 a 43%. Deslocamentos de 1.000km, com madeira serrada de diferentes densidades, representam entre 1,3 e 6,1% de redução do estoque de carbono da madeira; dados do GHG Protocol indicam valores entre 20,1% e 24,4%. Em 2007, o transporte legal de madeira serrada amazônica teria determinado consumo nacional de diesel estimado entre 0,16% e 0,56%; em termos de emissão nacional, assumindo o ano base de 2005, o resultado teria sido de 0,12% a 0,46%. O estoque líquido potencial, relativo à madeira serrada contabilizada na base DOF 2007 do IBAMA, considerando apenas a redução por transporte, teria potencialmente estocado entre 4,77 e 5,19 x106 tCO2.

The ALMT Family of Organic Acid Transporters in Plants and Their Involvement in Detoxification and Nutrient Security.

Science.gov (United States)

Sharma, Tripti; Dreyer, Ingo; Kochian, Leon; Piñeros, Miguel A

2016-01-01

About a decade ago, members of a new protein family of anion channels were discovered on the basis of their ability to confer on plants the tolerance toward toxic aluminum ions in the soil. The efflux of Al 3+ -chelating malate anions through these channels is stimulated by external Al 3+ ions. This feature of a few proteins determined the name of the entire protein family as Aluminum-activated Malate Transporters (ALMT). Meanwhile, after several years of research, it is known that the physiological roles of ALMTs go far beyond Al-detoxification. In this review article we summarize the current knowledge on this transporter family and assess their involvement in diverse physiological processes.

The ALMT family of organic acid transporters in plants and their involvement in detoxification and nutrient security

Directory of Open Access Journals (Sweden)

Tripti Sharma

2016-10-01

Full Text Available About a decade ago, members of a new protein family of anion channels were discovered on the basis of their ability to confer on plants the tolerance towards toxic aluminum ions in the soil. The efflux of Al3+-chelating malate anions through these channels is stimulated by external Al3+ ions. This feature of a few proteins determined the name of the entire protein family as Aluminum-activated Malate Transporters (ALMT. Meanwhile, after several years of research, it is known that the physiological roles of ALMTs go far beyond Al-detoxification. In this review article we summarize the current knowledge on this transporter family and assess their involvement in diverse physiological processes.

Diferentes metodologias aplicadas ao ensino de astronomia no Ensino Médio

Science.gov (United States)

Albrecht, E.; Voelzke, M. R.

2009-03-01

O presente trabalho de intervenção foi realizado junto à Escola Estadual Colònia dos Pescadores na cidade de Caraguatatuba, com très turmas do terceiro ano do Ensino Médio, envolvendo 119 alunos com idades entre 16 e 19 anos. A fase inicial foi composta de um questionário de vinte questíes dissertativas e objetivas, aplicado pelo professor titular da sala, que era o mesmo nas très turmas, para diagnosticar nos educandos os conceitos prévios sobre Astronomia e, partindo destes realizar um trabalho de intervenção nas classes envolvidas utilizando, em cada uma, metodologias diferentes: (A) sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervençíes necessárias; (B) de forma tradicional, com auxílio de multimídias para desenvolvimento das aulas e a terceira (C) tradicional, fazendo uso exclusivo de lousa e giz. Ao final do trabalho os alunos responderam novamente o questionário inicial para diagnosticar dentre as très metodologias utilizadas qual apresentou melhores aplicaçíes, os resultados iniciais foram comparados com os finais. Quando questionados a respeito do significado de Astronomia observou-se inicialmente que os acertos na turma A foram de 100%, turma B: 64%, turma C: 84%, após a intervenção os acertos foram: 100%, 97% e 85% respectivamente, demonstrando que houve um avanço significativo na turma B, a turma A manteve seu índice e a turma C evoluiu, porém não tanto quanto a B. Quando interrogados sobre quantos planetas vocè acha que existem em nosso Sistema Solar? os acertos foram: turma A: 39%, turma B: 48% e turma C: 46%, após o desenvolvimento do trabalho os acertos foram 94%, 97% e 90% respectivamente. Dentro das respostas obtidas observa-se que a metodologia tradicional com o auxílio de multimeios, aplicada na turma B, demonstrou melhores resultados, sendo a mais significativa. Outra conclusão muito importante é que apesar de o tema Astronomia ser amplamente

Enfoque Legal de Ciber Defensa Aplicada a Empresas

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Ronaldo Bach da Graça

2015-12-01

Full Text Available Este trabajo tiene como objetivo presentar la utilidad de ciberdefensa promovida por el Estado en favor de las empresas comerciales; que, en última instancia beneficia a toda la comunidad y el Estado. La investigación fue realizada por el método de enfoque descriptivo y lógico-intuitivo, mencionandose que la sociedad debe proteger a sus empresas como una forma de mantener la propia calidad de vida. Una forma de protección, relevante en el momento en que vivimos, se da a través de una adecuada protección ofrecida por la defensa cibernética. Es importante para el derecho de los negocios que se ocupe de las garantías constitucionales, que pueden ser apoyadas por un Estado que actúa con la defensa cibernética. En nuestros tiempos, doctrina y jurisprudencia en Brasil reconocen los derechos fundamentales de las personas jurídicas, y existe una relación de dependencia entre la comunidad y sus empresas comerciales que desemboca en una mejor calidad de vida, empleo y ingresos. Con el fin de preservar la seguridad nacional, deben recibir protección especial los activos intangibles de las empresas que son susceptibles a los ataques cibernéticos. El artículo contribuye al debate sobre la protección por la guerra cibernética de las empresas, concluyendo que la seguridad jurídica proporcionada por la actividad de la guerra cibernética en favor de las empresas y la protección de sus derechos fundamentales protege a la comunidad y el estado al que pertenece. Este trabajo fomenta la protección cibernética a las empresas per el Estado, como una especie de auto-protección y seguridad de toda la sociedad componente del Estado.

Growth and characterization of ternary Ni, Mg–Al and Ni–Al layered double hydroxides thin films deposited by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Birjega, R. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Vlad, A., E-mail: angela.vlad@gmail.com [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Matei, A.; Ion, V.; Luculescu, C.; Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Zavoianu, R. [University of Bucharest, Faculty of Chemistry, Department of Chemical Technology and Catalysis, 4-12 Regina Elisabeta Bd., Bucharest (Romania)

2016-09-01

Layered double hydroxides (LDHs) are a class of layered materials consisting of positively charged brucite-like layers and exchangeable interlayer anions. Layered double hydroxides containing a transition metal which undergoes a reversible redox reaction in the useful potential range have been proposed as electrode coating materials due to their properties of charge transport and redox catalysts in basic solutions. Ni–Al,(Ni,Mg)–Al and, as reference, non-electronically conductive Mg–Al double hydroxides thin films were obtained via pulsed laser deposition technique. The thin films were deposited on different substrates (Si, glass) by using a Nd:YAG laser (1064 nm) working at a repetition rate of 10 Hz. X-ray diffraction, Atomic Force Microscopy, Energy Dispersive X-ray spectroscopy, Fourier Transform Infra-Red Spectroscopy, Secondary Ions Mass Spectrometry, Impedance Analyzer and ellipsometry were the techniques used for the as deposited thin films investigation. The optical properties of Ni based LDH thin films and the effect of the Ni amount on the structural, morphological and optical response are evidenced. The optical band gap values, covering a domain between 3.84 eV and 4.38 eV, respond to the Ni overall concentration: the higher Ni amount the lower the band gap value. - Highlights: • Ternary Ni, Mg–Al and Ni–Al layered double hydroxides thin films were deposited. • The effect of the nickel is evidenced. • The possibility to tailor the materials accompanied by an optical response is shown.

La crisis económica en España : la crisis del sistema bancario

OpenAIRE

Pachón Gallegos, Ana Luna

2014-01-01

El trabajo profundiza en los factores determinantes que favorecieron la aparición de la crisis economica en España, haciendo una especial mención al desarrollo de dicha crisis en el sistema bancario nacional. Departamento de Economía Aplicada Grado en Marketing e Investigación de Mercados

El pulso de la Tierra

OpenAIRE

Instituto Geofísico del Perú

2010-01-01

Trata sobre la sismología y geodesia espacial aplicada a nuestro país. El BCRP agradece al IGP el haber compartido este artículo aparecido en la memoria institucional 2009, Presente y Futuro, el que contribuirá a ampliar nuestro conocimiento sobre el origen y comportamiento de los terremotos.

Nanostructural origin of semiconductivity and large magnetoresistance in epitaxial NiCo2O4/Al2O3 thin films

Science.gov (United States)

Zhen, Congmian; Zhang, XiaoZhe; Wei, Wengang; Guo, Wenzhe; Pant, Ankit; Xu, Xiaoshan; Shen, Jian; Ma, Li; Hou, Denglu

2018-04-01

Despite low resistivity (~1 mΩ cm), metallic electrical transport has not been commonly observed in inverse spinel NiCo2O4, except in certain epitaxial thin films. Previous studies have stressed the effect of valence mixing and the degree of spinel inversion on the electrical conduction of NiCo2O4 films. In this work, we studied the effect of nanostructural disorder by comparing the NiCo2O4 epitaxial films grown on MgAl2O4 (1 1 1) and on Al2O3 (0 0 1) substrates. Although the optimal growth conditions are similar for the NiCo2O4 (1 1 1)/MgAl2O4 (1 1 1) and the NiCo2O4 (1 1 1)/Al2O3 (0 0 1) films, they show metallic and semiconducting electrical transport, respectively. Post-growth annealing decreases the resistivity of NiCo2O4 (1 1 1)/Al2O3 (0 0 1) films, but the annealed films are still semiconducting. While the semiconductivity and the large magnetoresistance in NiCo2O4 (1 1 1)/Al2O3 (0 0 1) films cannot be accounted for in terms of non-optimal valence mixing and spinel inversion, the presence of anti-phase boundaries between nano-sized crystallites, generated by the structural mismatch between NiCo2O4 and Al2O3, may explain all the experimental observations in this work. These results reveal nanostructural disorder as being another key factor for controlling the electrical transport of NiCo2O4, with potentially large magnetoresistance for spintronics applications.

CuAlTe{sub 2}: A promising bulk thermoelectric material

Energy Technology Data Exchange (ETDEWEB)

Gudelli, Vijay Kumar [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502 205, Telangana (India); Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502 205, Telangana (India); Vaitheeswaran, G. [Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500 046, Telangana (India)

2015-11-05

Transport properties of Cu-based chalcopyrite materials are presented using the full potential linear augmented plane wave method and Boltzmann Semi-classical theory. All the studied compounds appear to be direct band gap semiconductors evaluated based on the Tran-Blaha modified Becke-Johnson potential. The heavy and light band combination found near the valence band maximum (VBM) drive these materials to possess good thermoelectric properties. Among the studied compounds, CuAlTe{sub 2} is found to be more promising, in comparison with CuGaTe{sub 2}, which is reported to be an efficient thermoelectric material with appreciable figure of merit. Another interesting fact about CuAlTe{sub 2} is the comparable thermoelectric properties possessed by both n- type and p-type carriers, which might attract good device applications and are explained in detail using the electronic structure calculations. - Highlights: • Band structure calculation of Cu(Al,Ga)Ch{sub 2} compounds with the TB-mBJ functional. • Mixed heavy-light bands near Fermi level might favour good thermoelectric properties. • Among the investigated compounds CuAlTe{sub 2} appears to be more promising. • Thermoelectric properties of CuAlTe{sub 2} are almost comparable with CuGaTe{sub 2}. • Both n,p-type thermoelectric properties of CuAlTe{sub 2} can attract device applications.

Ética organizacional aplicada. Estudo de caso de uma organização de serviços sociais na Espanha

Directory of Open Access Journals (Sweden)

Carla Cubillos-Vega

2018-01-01

Full Text Available Estudiar la ética organizacional de una organización de servicios sociales es de suma importancia, dado el cometido público de este tipo de entidades con la sociedad. Dicho estudio se puede realizar analizando la estructura y el comportamiento de la organización con base en la cultura ética organizacional, donde convergen distintos valores: individuales, profesionales y de la entidad. Este artículo tiene por objetivo presentar un estudio de caso en el que se analiza la ética de una organización privada de servicios sociales española, identificando su modelo de gestión ética. Para ello, se utilizó el método cualitativo de observación participante y entrevistas en profundidad. Se explora algunos elementos que articulan el estudio de la cultura ética organizacional, así como de la ética aplicada a la intervención social; además, se identificaron los valores implícitos y explícitos compartidos, que operan transversalmente en dicha organización y el modo en que estos inciden en su actividad.

Flux and reactive contributions to electron transport in methane

International Nuclear Information System (INIS)

Ness, K.F.; Nolan, A.M.

2000-01-01

A previously developed theoretical analysis (Nolan et al. 1997) is applied to the study of electron transport in methane for reduced electric fields in the range 1 to 1000 Td. The technique of analysis identifies the flux and reactive components of the measurable transport, without resort to the two-term approximation. A comparison of the results of the Monte Carlo method with those of a multiterm Boltzmann equation analysis (Ness and Robson 1986) shows good agreement. The sensitivity of the modelled electron transport to post-ionisation energy partitioning is studied by comparison of three ionisation energy partitioning regimes at moderate (300 Td) and high (1000 Td) values of the reduced electric field. Copyright (2000) CSIRO Australia

Scaling with toroidal current of impurity transport in ATC

International Nuclear Information System (INIS)

Marmar, E.S.; Cohen, S.A.; Cecchi, J.L.

1976-06-01

An experiment measuring the scaling with changing plasma conditions of a parameter characteristic of the transport of aluminum injected into the ATC tokamak is discussed. This parameter is the time after injection at which the photon signal from Al XI reaches its maximum. It is found that the data are in agreement with the predictions of a computer code which uses neoclassical theory in the Pfirsch-Schluter regime. An approximate model describing impurity transport in ATC is also presented. This model is utilized to calculate the expected scaling with current of the aluminum transport assuming classical, neoclassical and pseudoclassical forms for the diffusion coefficient. The data are in agreement with both the neoclassical and pseudoclassical results from this model

Diseño del sistema scada del proceso de transporte de cemento para holcim-Ecuador

OpenAIRE

Coronel Perez, Ivan Ariolfo; Arreaga Medina, Miguel Angel; Manssur Hanna, Alberto

2009-01-01

Entre los diferentes procesos de fabricación de cemento se encuentra el de transportación del producto y es en este punto en el cual desarrollamos el siguiente proyecto, el mismo tiene por objeto diseñar un sistema automático para operar dicha línea de transporte, empezando en los silos de almacenamiento al granel hasta las máquinas envasadoras desde donde se lo despacha al mercado de consumo. La automatización permitirá a la empresa una operación más veloz y estable del transporte del ...

Theory of transport through molecular magnets

Science.gov (United States)

Schoeller, Herbert

2007-03-01

Quantum transport through single molecular magnets (SMM) is starting to become a new exciting field in molecular spin electronics. Recent experiments [1,2] have shown that magnetic excitations can be identified in transport measurements and that NDC effects and complete current suppression can be explained by charge dependent anisotropies. Recent theoretical investigations [3,4,5] are presented which demonstrate fingerprints of quantum tunneling of magnetization (QTM). For weak tunneling, the violation of spin-selection rules leads to the occurence of fake resonances with temperature-dependent position [3]. For strongtunneling, it is show that a pseudo spin-1/2 Kondo effect is induced by QTM. If the Kondo temperature TK is smaller than the distance to excited magnetic states, selection rules depending on spin and symmetry of the SMM are derived for the Kondo effect to occur [4]. If TK exceeds the anisotropy barrier, it is shown that a reentrant Kondo effect can be induced by application of a longitudinal magnetic field for SMM with half-integer or integer spin [5]. This effect can be used for transport spectroscopy of the various anisotropies characterizing a SMM. [1] H.B. Heersche et al., Phys. Rev. Lett. 96, 206801 (2006). [2] Moon-Ho Jo et al., Nano Lett. 6, 2014 (2006). [3] C. Romeike, M.R. Wegewijs, H. Schoeller, Phys. Rev. Lett. 96, 196805 (2006). [4] C. Romeike, M.R. Wegewijs, W. Hofstetter, H. Schoeller, Phys. Rev. Lett. 96, 196601 (2006). [5] C. Romeike, M.R. Wegewijs, W. Hofstetter, H. Schoeller, to be published in Phys. Rev. Lett., cond-mat/0605514.

Cargo distributions differentiate pathological axonal transport impairments.

Science.gov (United States)

Mitchell, Cassie S; Lee, Robert H

2012-05-07

Axonal transport is an essential process in neurons, analogous to shipping goods, by which energetic and cellular building supplies are carried downstream (anterogradely) and wastes are carried upstream (retrogradely) by molecular motors, which act as cargo porters. Impairments in axonal transport have been linked to devastating and often lethal neurodegenerative diseases, such as Amyotrophic Lateral Sclerosis, Huntington's, and Alzheimer's. Axonal transport impairment types include a decrease in available motors for cargo transport (motor depletion), the presence of defective or non-functional motors (motor dilution), and the presence of increased or larger cargos (protein aggregation). An impediment to potential treatment identification has been the inability to determine what type(s) of axonal transport impairment candidates that could be present in a given disease. In this study, we utilize a computational model and common axonal transport experimental metrics to reveal the axonal transport impairment general characteristics or "signatures" that result from three general defect types of motor depletion, motor dilution, and protein aggregation. Our results not only provide a means to discern these general impairments types, they also reveal key dynamic and emergent features of axonal transport, which potentially underlie multiple impairment types. The identified characteristics, as well as the analytical method, can be used to help elucidate the axonal transport impairments observed in experimental and clinical data. For example, using the model-predicted defect signatures, we identify the defect candidates, which are most likely to be responsible for the axonal transport impairments in the G93A SOD1 mouse model of ALS. Copyright © 2012 Elsevier Ltd. All rights reserved.

New data on the phase transition in SrAlF5

International Nuclear Information System (INIS)

Bondarev, V. S.; Vasil’ev, A. D.; Gorev, M. V.; Mel’nikova, S. V.; Isaenko, L. I.

2011-01-01

The thermophysical characteristics of the SrAlF 5 crystal have been investigated on samples differing in quality. The results of studying the thermal expansion and birefringence in heating-cooling cycles in the temperature range of 100–800 K have been analyzed. Specific heat anomalies are found whose position on the temperature scale depends on the sample quality and thermal history. An X-ray diffraction analysis of SrAlF 5 showed the absence of structural phase transitions in the temperature range under study. It is suggested that the specific heat anomalies are related to the peculiarity of transport properties of this crystal.

Ion transport analysis of a high beta-poloidal JT-60U discharge

International Nuclear Information System (INIS)

Horton, W.; Tajima, T.; Dong, J.-Q.; Kim, J.-Y.; Kishimoto, Y.

1997-01-01

The high beta-poloidal discharge number 17110 in JT-60U (JT-60 Team, IAEA, Vienna, 1993) that developes an internal transport barrier is analysed for the transport of ion energy and momentum. First, the classical ion temperature gradient stability properties are calculated in the absence of sheared plasma flows to establish the L-mode transport level prior to the emergence of the transport barrier. Then the evolving toroidal and poloidal velocity profiles reported by Koide et al (1994 Phys. Rev. Lett. 72 3662) are used to show how the sheared mass flows control the stability and transport. Coupled energy-momentum transport equations predict the creation of a transport barrier. The balance of the steep ion temperature gradient against the magnetic shear and sheared mass flow is calculated for the profiles in the 17110 discharge. (Author)

Discrete Diffusion Monte Carlo for Electron Thermal Transport

Science.gov (United States)

Chenhall, Jeffrey; Cao, Duc; Wollaeger, Ryan; Moses, Gregory

2014-10-01

The iSNB (implicit Schurtz Nicolai Busquet electron thermal transport method of Cao et al. is adapted to a Discrete Diffusion Monte Carlo (DDMC) solution method for eventual inclusion in a hybrid IMC-DDMC (Implicit Monte Carlo) method. The hybrid method will combine the efficiency of a diffusion method in short mean free path regions with the accuracy of a transport method in long mean free path regions. The Monte Carlo nature of the approach allows the algorithm to be massively parallelized. Work to date on the iSNB-DDMC method will be presented. This work was supported by Sandia National Laboratory - Albuquerque.

PERSPECTIVAS DO SISTEMA DE TRANSPORTE URBANO DE LONDRINA - PARANÁ

Directory of Open Access Journals (Sweden)

Mirian Vizintim Fernandes Barros

2014-03-01

Full Text Available O artigo propõe indicar os problemas encontrados no atual sistema de transporte urbano na cidade de Londrina - Paraná, marcado pela predominância do uso do transporte individual e do coletivo ineficiente e de alto custo. Para tanto, utilizou-se ferramenta dos Sistemas de Informação Geográfica (SIG para, por meio da manipulação dos dados, confirmar a ideia da intrínseca e necessária integração entre o planejamento do uso e ocupação do solo (sobretudo da densidade demográfica e do transporte urbano, essencial para delinear diretrizes de melhorias no sistema coletivo de deslocamento. Identificado os principais problemas, propostas são traçadas e, algumas perspectivas são discutidas objetivando, além da melhoria no sistema de transporte urbano de Londrina, a reflexão sobre o ideal de uma cidade inclusiva, do ponto de vista dos transportes.

Vertical transport in isotype InAlN/GaN dipole induced diodes grown by molecular beam epitaxy

Science.gov (United States)

Fireman, M. N.; Li, Haoran; Keller, Stacia; Mishra, Umesh K.; Speck, James S.

2017-05-01

InAlN dipole diodes were developed and fabricated on both (0001) Ga-Face and (" separators="| 000 1 ¯) N-face oriented GaN on sapphire templates by molecular beam epitaxy. The orientation and direction of the InAlN polarization dipole are functions of the substrate orientation and composition, respectively. Special consideration was taken to minimize growth differences and impurity uptake during growth on these orientations of opposite polarity. Comparison of devices on similarly grown structures with In compositions in excess of 50% reveals that dipole diodes shows poorer forward bias performance and exhibited an increase in reverse bias leakage, regardless of orientation. Similarly, (0001) Ga-face oriented InAlN at a lowered 40% In composition had poor device characteristics, namely, the absence of expected exponential turn on in forward bias. By contrast, at In compositions close to 40%, (" separators="| 000 1 ¯) N-face oriented InAlN devices had excellent performance, with over five orders of magnitude of rectification and extracted barrier heights of 0.53- 0.62 eV; these values are in close agreement with simulation. Extracted ideality factors ranging from 1.08 to 1.38 on these devices are further evidence of their optimal performance. Further discussion focuses on the growth and orientation conditions that may lead to this discrepancy yet emphasizes that with proper design and growth strategy, the rectifying dipole diodes can be achieved with InAlN nitride dipole layers.

Evaluation of advanced propulsion options for the next manned transportation system: Propulsion evolution study

Science.gov (United States)

Spears, L. T.; Kramer, R. D.

1990-01-01

The objectives were to examine launch vehicle applications and propulsion requirements for potential future manned space transportation systems and to support planning toward the evolution of Space Shuttle Main Engine (SSME) and Space Transportation Main Engine (STME) engines beyond their current or initial launch vehicle applications. As a basis for examinations of potential future manned launch vehicle applications, we used three classes of manned space transportation concepts currently under study: Space Transportation System Evolution, Personal Launch System (PLS), and Advanced Manned Launch System (AMLS). Tasks included studies of launch vehicle applications and requirements for hydrogen-oxygen rocket engines; the development of suggestions for STME engine evolution beyond the mid-1990's; the development of suggestions for STME evolution beyond the Advanced Launch System (ALS) application; the study of booster propulsion options, including LOX-Hydrocarbon options; the analysis of the prospects and requirements for utilization of a single engine configuration over the full range of vehicle applications, including manned vehicles plus ALS and Shuttle C; and a brief review of on-going and planned LOX-Hydrogen propulsion technology activities.

Design rules for modulation doped AlAs quantum wells

Science.gov (United States)

Chung, Yoon Jang; Baldwin, K. W.; West, K. W.; Kamburov, D.; Shayegan, M.; Pfeiffer, L. N.

AlxGa1-xAs/AlAs/AlxGa1-xAs quantum wells were grown with various barrier compositions ranging from x =0.26 to x =0.8. We investigate the modulation doping characteristics of the samples by magneto-transport measurements. The carrier concentration in the well peaks near the barrier alloy fraction of x =0.26 in the dark and near x =0.38 after illumination with a red LED. This behavior is consistent with the results in a separate study for AlxGa1-xAs/GaAs/AlxGa1-xAs quantum wells in the range of x =0.26 to x =1.0. We show from a charge transfer model that the calculated energy difference between the conduction band offset at the well interface and the donor energy level, ΔEC-ED, coincides for the two types of wells. This implies that, despite the differing positions of the conduction band minimum for the GaAs and AlAs wells, the doping of either well is governed by the electronic properties of the barrier. Based on this knowledge we designed high quality AlAs quantum wells with low (1 x 1011 cm-2) and high (3 x 1011 cm-2) density, and the magneto-transport data show clear signals of the fractional quantum Hall effect (2/3, 3/5, 4/7 for low density and 5/3, 8/5 for high density). Work supported by the NSF (Grants DMR-1305691, ECCS-1508925, and MRSEC DMR-1420541), the DOE Basic Energy Sciences (Grant DE-FG02-00-ER45841), the Gordon and Betty Moore Foundation (Grant GBMF4420), and the Keck Foundation.

Na+-dependent nucleoside transport in liver: two different isoforms from the same gene family are expressed in liver cells.

OpenAIRE

Felipe, A; Valdes, R; Santo, B; Lloberas, J; Casado, J; Pastor-Anglada, M

1998-01-01

Hepatocytes show a Na+-dependent nucleoside transport activity that is kinetically heterogeneous and consistent with the expression of at least two independent concentrative Na+-coupled nucleoside transport systems (Mercader et al. Biochem. J. 317, 835-842, 1996). So far, only a single nucleoside carrier-related cDNA (SPNT) has been isolated from liver cells (Che et al. J. Biol. Chem. 270, 13596-13599, 1995). This cDNA presumably encodes a plasma membrane protein responsible for Na+-dependent...

Evolution of magnetic and transport properties in pore-modified CoAlO antidot arrays

International Nuclear Information System (INIS)

Ma, Y G; Lim, S L; Ong, C K

2007-01-01

CoAlO composite antidot arrays were fabricated on self-organized porous anodic aluminium oxide (AAO) membranes. The effects of pore size and film thickness on the magnetism and magnetotransport properties of the CoAlO films were investigated. On increasing the pore dimensions in the arrays, an anisotropic to isotropic magnetism transition was observed. The result is discussed based on the competitive contributions from the external field induced uniaxial anisotropy and the topology-induced shape anisotropy superimposed by the stray fields from the pore channels. Magnetoresistance showed corresponding variations with increasing pore sizes, as evidenced by a magnetoresistance variation from typically anisotropic to nearly isotropic behaviour. When deposited on large-pored AAO membranes, the antidot arrays showed no obvious anisotropy at different film thicknesses. It led to negligible magnetoresistive loops in the thick films of high structural continuity. The possible reasons for spin-independent electron scatterings are discussed

Development of AL{sub 2}O{sub 3} - ZrO{sub 2} ceramic composite reinforced with rare earth oxides (Y{sub 2}O)3) for inert coating of storage and transport systems of crude petroleum; Desenvolvimento de composito ceramico Al{sub 2}O{sub 3} - ZrO{sub 2} reforcada com oxido de terra rara para sistema de armazenamento e transporte de petroleo cru

Energy Technology Data Exchange (ETDEWEB)

Silva, J.C.; Yadava, Y.P.; Sanguinetti Ferreira, R.A.; Albuquerque, L.T., E-mail: juliana.carvalhosilva@ufpe.br [Universidade Federal de Pernambuco (UFPE), Jaboatao de Guararapes, PE (Brazil). Centro de Tecnologia. Departamento de Engenharia Mecanica

2014-07-01

The advancement of the oil sector has generated the need for the use of materials resistant to aggressive environments to oil. Although ceramics have high melting point and high hardness is, on the other hand, more fragile and less tough, which can cause damage to the metal structure. The Al{sub 2}O{sub 3} based ceramics reinforced with rare earth oxide can improve tenaciousness and makes the ceramic material more resistant. This article aims to present the production of composite Al{sub 2}O{sub 3} - Y{sub 2}O{sub 3} stabilized ZrO{sub 2} by uniaxial pressing, following sintering (1200-1350 deg C). Structural and microstructural characterizations as XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy) and mechanical tests as Vickers hardness, % absorption and % linear shrinkage were conducted to evaluate the feasibility of using the composite and ceramic coating for storage and transportation of oil tanks. The results indicate that the proportions of 5%, 10% and 30% ZrO{sub 2} make it suitable as a good composite suitable coating. (author)

Laser metrology applied to the nuclear maintenance; Metrologia laser aplicada al mantenimiento nuclear

Energy Technology Data Exchange (ETDEWEB)

Garrido Garcia, J.; Sarti Fernandez, F.

2012-07-01

The development of this paper focuses on providing an overview of the state of the art about laser metrology. This type of equipment combines the measurement philosophy of laser scanning with the great precision of the robotic equipment of auscultation. Getting micron.

La neurociencia aplicada al estudio del género: ¿una nueva perspectiva?

OpenAIRE

Pallarés Domínguez, Daniel Vicente

2011-01-01

Setzenes Jornades de Foment de la Investigació (Any 2011) La neurociencia es a día de hoy una ciencia experimental que va conformando su sentido y modificando las disciplinas en las que influye. Como método científico utiliza todas las herramientas posibles para explicar el funcionamiento cerebral humano sobre todo, y lo estudia desde el parámetro de los estímulos y reacciones innatas con los que crea circuitos neuronales, ayudando a los seres humanos a tomar decisiones...

Una tipologia de la definició lexicogràfica aplicada al «DGLC»

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Victòria Alsina

2015-10-01

Full Text Available This article aims at establishing a typology of lexicographic definitions by means of the study of the definitions found in Pompeu Fabra’s Diccionari General de la Llengua Catalana in nouns, verbs and adjectives. Several typologies based on different criteria are arrived at: in the first place, the difference between synthetic and periphrastic definitions is established; this classification is based on the amount of words used in the definition. In the second place, the typology which comprises substantial and relational definitions is explained; it was established by Rey-Debove (1967 and it is based on the metalanguage used in the definition. And thirdly, a classification within substantial periphrastic definitions is established, based on the defining words used: lexical and semo-componential definitions.

Musicoterapia aplicada al desarrollo del lenguaje en alumnos con Síndrome de Down

OpenAIRE

Cabezudo Unzueta, María del Henar

2015-01-01

En la actualidad son muchas las terapias que surgen como alternativas a los convencionales métodos de tratamiento. En el ámbito de la Educación Especial una de las técnicas empleadas es la Musicoterapia, debido a su amplia aplicación en alumnos con necesidades educativas específicas (discapacidad intelectual, autismo, parálisis cerebral, trastorno por déficit de atención e hiperactividad...) además de sus beneficios en la prevención y mejora de la salud física, mental y emocional que produce ...

Theory-based transport simulation of tokamaks: density scaling

International Nuclear Information System (INIS)

Ghanem, E.S.; Kinsey, J.; Singer, C.; Bateman, G.

1992-01-01

There has been a sizeable amount of work in the past few years using theoretically based flux-surface-average transport models to simulate various types of experimental tokamak data. Here we report two such studies, concentrating on the response of the plasma to variation of the line averaged electron density. The first study reported here uses a transport model described by Ghanem et al. to examine the response of global energy confinement time in ohmically heated discharges. The second study reported here uses a closely related and more recent transport model described by Bateman to examine the response of temperature profiles to changes in line-average density in neutral-beam-heated discharges. Work on developing a common theoretical model for these and other scaling experiments is in progress. (author) 5 refs., 2 figs

Transport of radionuclides in the atmosphere during complex meteorological conditions

International Nuclear Information System (INIS)

Antic, D.; Telenta, B.

1991-01-01

Radionuclides from various sources (nuclear and fossil fuel power plants, nuclear facilities, medical facilities, etc.) are being released to the atmosphere. The meteorological conditions determine the atmospheric turbulence, dispersion, and removal processes of the radionuclides. A two-dimensional version of the cloud model based on the Klemp-Wilhelmson dynamic and Lin et al.'s microphysics and thermodynamics has been adapted and used to simulate the transport of radionuclides emitted from a power plant or other source to the atmosphere. Calculations of the trajectories and radii for a few puffs are included in this paper. These numerical investigations show that the presented model can be used for the transport simulation of radionuclides and for the assessment of the radiological impact of power plants and other sources in safety assessments and comparative studies. Because it can simulate puff trajectories, this model is especially valuable in the presence of complex meteorological conditions

LA FORMACIÓN UNIVERSITARIA EN INVESTIGACIÓN APLICADA Y EL CONTEXTO DE LA COMPLEJIDAD: UNA PERSPECTIVA ESTRATÉGICA PARA LA INNOVACIÓN EN INGENIERÍA

Directory of Open Access Journals (Sweden)

Renzo Astorne

2011-12-01

Full Text Available RESUMEN: ¿Cómo afrontar la educación universitaria para la formación en investigación aplicada en un “cambio de época” donde el conocimiento se ha vuelto el activo substancial a la generación de valor en los bienes y servicios de las organizaciones? ¿Qué estrategia implementar cuando su eficacia se tiende a medir a través de mecanismos externos a las áreas de investigación de la universidad? Dos interrogantes que permiten, por un lado recorrer la forma tradicional en que la universidad reitera mecanismos triviales de formación en investigación para ingeniería, y por otro, el enfoque holístico -sistémico–cibernético- de promover esta formación para el contexto de la complejidad. Esta ponencia repasa la experiencia en áreas de ingeniería, con énfasis en la estrategia educativa encaminada a lograr una visión sobre el conocimiento, donde la universidad encuentra una creciente dificultad para establecer la dirección de sus áreas de investigación aplicada en ingeniería y los procesos de formación asociados; vale decir, para establecer la estrategia. ABSTRACT: How to approach higher education for training in applied research in a "change of epoch" where knowledge has become a substantial asset to the generation of value in goods and services in organizations? What strategy should be implemented when its efficiency tends to be measured through mechanisms external to the research areas of the university? Two questions that allow, on the one hand, going the traditional way in which the university reiterates trivial mechanisms for engineering research training, and, on the other, the holistic -systemic-cybernetic- approach that promotes this same training in the context of complexity. This paper reviews the experience in the field of engineering, emphasizing the educational strategy aimed at achieving an insight of knowledge, where the university is facing increasing difficulty in setting the direction of the areas of

Familial ALS

Science.gov (United States)

Boylan, Kevin

2015-01-01

Synopsis Genes linked to ALS susceptibility are being identified at an increasing rate owing to advances in molecular genetic technology. Genetic mechanisms in ALS pathogenesis appear to exert major effects in ~10% of patients, but genetic factors at some level may be important components of disease risk in most ALS patients. Identification of gene variants associated with ALS has informed concepts of the pathogenesis of ALS, aided the identification of therapeutic targets, facilitated research to develop new ALS biomarkers, and supported the establishment of clinical diagnostic tests for ALS-linked genes. Translation of this knowledge to ALS therapy development is ongoing. PMID:26515623

Malamih al-Ashwat al-'Arabiyyah wa Makharijaha

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Amrah Muhammad Kasim

2015-12-01

Full Text Available This writing discusses on al-ashwat al-‘arabiyyah that is known with “phonetic” term. It talks and interprets makharij al-huruf or place for producing sounds and also processing production of sounds by parts of mouth in Arabic language. The problems of sounds and its systems in Arabic language have been conducted by the scholars of al-ashwat al-‘arabiyyah attractively, neatly, and detail and gotten ahead the phonetic western scholars. Part of their analysis results formulate the study about al-ashwat al-sakinah (al-Shamit is known with vocal and consonant sounds in research questions shawait – shawamit. Ibnu Jinni has formulated “harakat”(wowel in Arabic language and dimension of letter  mad and liyn on alif  letter - waw - ya’ (ا و ي, from these letters create  harakat fathah, dammah, and kasrah. Moreover, in this writing also exist the description of hija’i letters and its makhraj that are correct from parts of mouth and the unity of coordinative sounds that produce sounds in morphemes arrangement, in one word that produces meaning. The result of phonological study has divided al-ashwat to be kinds of sound like the pronounced sounds, produced sounds from mouth, and heard sound.

Pressureless infiltration of porous Al2O3 preform in molten 6061 commercial aluminium alloy

International Nuclear Information System (INIS)

Marin, J.; Olivares, L.; Moreno, C.; Ordonez, S.; Martinez, V.

2001-01-01

This paper presents an infiltration study of Al 2 O 3 samples containing, approximately, 40% of pores with 1μ average radios. These samples were totally infiltrated with Al-6061 at 1100 deg C for 24 hs in air. Microstructural analysis showed the presence of an alumina matrix infiltrated through mechanisms that combine reactive processes and capillarity, and thus being coherent with the presence of open and closed porosity. The metallographic analysis showed open porosity infiltrated with Al-6061 by capillarity, while SEM micrographs corresponding to this system also showed closed pores filled with metal, that was transported into the ceramic matrix through a reactivate infiltration mechanism. The EDAX analysis for the Al 2 O 3 /Al 6061 system showed areas rich in silicon and copper at the metal-ceramic interface, while the ceramic phase showed the presence of Mg. XRD identified the presence of the MgAl 2 O 4 spinel in the ceramic phase

Método de Evaluación Dinámica de Planes en Sistemas Inteligentes Autónomos

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Ezequiel González

2015-05-01

Full Text Available La característica principal de los sistemas inteligentes autónomos es que son capaces de auto proponerse planes, de ejecutarlos y de retroalimentar su base de conocimiento a partir de la información que extraen del entorno. En este trabajo se presenta una revisión de los métodos de aprendizaje y planificación de dichos sistemas, para luego centrar la investigación sobre la arquitectura LOPE. Aunque publicaciones posteriores implementaron modificaciones y extensiones que lograron mejorar su rendimiento, se han identificado ciertos aspectos del modelo que aún no han sido abordados. Por tal motivo, se proponen mejoras para ser aplicadas dentro de los módulos de planificación y aprendizaje, como también refinamientos al proceso de control y ejecución. Además, se elabora un indicador que permite una evaluación integral de la arquitectura y una comparación objetiva de los resultados alcanzados con las distintas mejoras aplicadas, en relación al diseño original.

adecuado a la cultura de ocio y diversión

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Andreas Otto Brunold

2007-01-01

Full Text Available El incremento de la cultura del ocio no solo genera divisas y fuentes de trabajo sino también alteraciones ambientales. El presente artículo esgrime algunas pautas metodológicas y principios para establecer una educación orientada hacia una política de desarrollo sostenible. Una pedagogía aplicada a la cultura del ocio busca generar una conciencia de protección ambiental. Un elemento especial en un turismo de masa, como caracteriza a Mallorca, debe centrarse en la preservación de la identidad cultural amenazada por diversas manifestaciones como idioma, costumbres, valores e intereses que un turista no considera o los obvia. Un enfoque interdisciplinario adecuado a una filosofía de desarrollo sostenible ya no exige entonces al turista tan solo el pasaje y equipaje, sino básicamente la predisposición a reglas de conducta que buscan el bienestar colectivo y la protección al ambiente. La contribución de los jóvenes a esta pedagogía aplicada puede ser garantizar un éxito multiplicador.

Bilateral Transport Cost, Infrastructure, Common Bilateral Ties and Political Stability.

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Danielken Molina

2010-05-01

Full Text Available Los costos de transporte son una de las más importantes fuentes de barreras al comercio. Inspirados por este aspecto, utilizamos un modelo empírico ad-hoc con el fin de examinar los posibles determinantes de los costos de transporte. Utilizando una base de datos de costos de transporte bilaterales para el año 1990, replicamos el trabajo de Limao y Venables (2001 y encontramos que el efecto de su ´índice de infraestructura sobre los costos de transporte no es robusto. Siguiendo a Micco (2004 y Micco y Serebrinzky (2005 calculamos dos ´índices alternativos de infraestructura. Utilizando estos ´índices encontramos que aparte de la distancia, la infraestructura, la estabilidad política, las relaciones bilaterales comunes y los acuerdos de cielos abiertos son otros importantes canales mediante los cuales los costos de transporte pueden reducirse.

Efecto del tratamiento térmico posterior sobre la resistencia al desgaste por deslizamiento de un recubrimiento base níquel depositado por HVOF

Directory of Open Access Journals (Sweden)

Cadenas, P.

2007-02-01

Full Text Available In the present research, a nickel base coating was deposited on an AISI 1020 substrate by using high velocity oxy-fuel technique (HVOF. The coating was subsequently post heat -treated by means of an oxyacetylene flame. For the conditions evaluated in the present study, it was found that the CTT coating has 1,15 better wear resistance for the smaller level of the applied load and nearly 50 times for the highest level of the applied load when compared to the STT coatings. These results have been attributed to a better distribution of the hard phases, better cohesion between particles and an increase in hardness, as consequence of the post heat treatment process. A severe wear regime was found for all the samples since the wear rates presented values which were higher than 1·10-5 mm3/m. For the CTT coatings, the wear mechanism was mainly due to the adhesion and oxidation phenomena, meanwhile for the steel counterpart mechanisms such oxidation, grooving and three body abrasion were observed.

En el presente trabajo, se depositó un recubrimiento base níquel sobre un acero AISI 1020 por la técnica de termorrociado de alta velocidad que utiliza oxígeno como combustible (High Velocity Oxygen Fuel - HVOF y, posteriormente, fue tratado térmicamente mediante llama oxiacetilénica. Para las condiciones evaluadas en este estudio, se encontró que el recubrimiento CTT tiene desde 1,15 veces más resistencia al desgaste, para el menor nivel de carga aplicada y mayor velocidad de deslizamiento y, hasta 50 veces más resistencia al desgaste para el mayor nivel carga aplicada y mayor velocidad de deslizamiento, comparado con el recubrimiento STT. Estos resultados se atribuyeron a una mejor distribución de las fases endurecedoras, una mejor cohesión entre partículas y un aumento en la microdureza del recubrimiento, como consecuencia del tratamiento térmico posterior. El régimen de desgaste presente en todas las muestras fue severo, ya que las

Simulación de eventos discretos y líneas de balance, aplicadas al mejoramiento del proceso constructivo de la cimentación de un edificio

OpenAIRE

Gomez, Adriana; Ávila Díaz, Jorge Orlando; Quintana Pulido, Natalia

2014-01-01

El objeto de este trabajo fue establecer propuestas de mejoramiento al proceso de planeación de tiempos y costos en la etapa de cimentación de un edificio, a partir de la integración de herramientas como simulación de eventos discretos, programación con líneas de balance y metodologías Building Information Modeling – BIM -- A partir de mediciones en campo se levantó información para la elaboración de un modelo de simulación de eventos discretos que imitara el proceso constructivo real -- Se p...

Transient oxidation of Al-deposited Fe-Cr-Al alloy foil

International Nuclear Information System (INIS)

Andoh, A.

1997-01-01

The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas (θ-Al 2 O 3 , γ-Al 2 O 3 ). Scales consisting of θ-Al 2 O 3 and a small amount of α-Al 2 O 3 develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of θ-Al 2 O 3 and α-Al 2 O 3 grow rapidly on the Al-deposited foil. The transformation from θ-Al 2 O 3 to α-Al 2 O 3 is very fast, and the scales result in only α-Al 2 O 3 . In contrast, α-Al 2 O 3 scales containing a minor amount of FeAl 2 O 4 develop on the alloy foil. The growth rate of α-Al 2 O 3 scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.)

The effects of methylglyoxal-bis(guanylhydrazone) on spermine binding and transport in liver mitochondria.