Códigos QR: Museografía Nómade para la puesta en valor del patrimonio cultural

Directory of Open Access Journals (Sweden)

Lilian Meneses Plaza

2014-07-01

Full Text Available En la última década el sector cultural se ha apropiado de los avances científicos y las nuevas tecnologías para crear imágenes, sonidos, objetos y experiencias comunicacionales digitales que hacen más atractivo el patrimonio, mejorando la oferta de los museos y sitios patrimoniales desde el punto de vista turístico, cultural y educativo. Entre los medios que podemos mencionar destacan los museos virtuales, salas de exhibición 3D, audio-guías, códigos QR y aplicaciones para teléfonos móviles, entre otros, lo que deriva en una oferta novedosa y eficiente para la puesta en valor del patrimonio cultural. En el artículo se propone una metodología orientativa basada en la Interpretación del Patrimonio y la Museografía Nómada, para desarrollar una herramienta de gestión patrimonial apoyada en el uso de códigos QR. En esta propuesta se utilizó como referente la Ciudad de Valparaíso - Sitio Patrimonio de la Humanidad- dado que posee aptitudes de museo al aire libre, alta demanda por el turismo cultural y, además, constituye un lugar emblemático para la gestión patrimonial chilena en espacios urbanos habitados. Abstract From last decade that the cultural sector has taken the scientific advances and the new technologies to create images, sounds, objects and digital communication experiences that make the heritage more attractive, improving the museums and patrimonial sites offer to the tourism, the culture and education. Some the supports that we can mention are the virtual museums, 3D rooms, sonorous guide, QR codes and app for mobiles, etc.,presenting a new and efficient offer for putting in value the cultural heritage. In this article I propose a methodology guide based on the Heritage Interpretation and the Nomad Museography, to develop a heritage management tool about QR codes. In this methodology I use Valparaíso as example -World Heritage Site- because possesses aptitudes of outdoors museum, a high cultural tourism demand

Air permeability of the artificially synthesized Zn-Al-Mg alloy rusts

International Nuclear Information System (INIS)

Ishikawa, Tatsuo; Ueda, Masato; Kandori, Kazuhiko; Nakayama, Takenori

2007-01-01

The rust particles of Zn-Al-Mg alloys were synthesized from aqueous solutions dissolving ZnCl 2 , AlCl 3 , and MgCl 2 at different atomic ratios of the metal ions. The crystal phase and particle morphology of the products depended on the composition of the starting solutions. The compactness of the layers of the products was estimated by measuring their air permeability. The layer of mixed metal hydroxide chloride formed at Zn:Al:Mg = 1:1:1 showed a highest compactness, that was ascribed to the preferred orientation of the fine plate particles. The addition of Mg(II) made plate particles smaller to give more compact layers

Effect of Air Pollutants on Rain Water Characteristics in Hammam Al-Aleel District/ Al-Erej Village South of Mosul City

Directory of Open Access Journals (Sweden)

Ayad F. Qasim

2012-06-01

Full Text Available This study focused on Hammam Al-Aleel district/ Al-Erej village which is located south of Mosul city. This area has been suffering from spreading the air-pollutants resulted from the chimneys of Hammam Al-Aleel cement factories. Different areas were chosen for collecting samples of the rain water from December 2008 to March 2009. The study showed that rain-water is generally basic. The tests show an increase in ( EC, Mg+2, Ca+2, Cl-1, SO4-2 and NO-1,  due to the air pollutants emitted from local industries. The concentration of heavy elements represented by  Pb and Cd were high and this increase is due to the source of these elements from burning of the crude oil which is used in running the rotating kiln to produce the clinker in cement factory, In addition to the fuel used for  running vehicle and the friction between tires and  road.

Performance of Mg-14Li-1Al-0.1Ce as anode for Mg-air battery

Energy Technology Data Exchange (ETDEWEB)

Ma, Yibin; Li, Deyu [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Li, Ning [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China); Zhang, Milin; Huang, Xiaomei [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China)

2011-02-15

In this research, a new Mg-air battery based on Mg-14Li-1Al-0.1Ce was prepared and the battery performance was investigated by constant current discharge test. The corrosion behavior of Mg, AZ31 and Mg-Li-Al-Ce were studied by self-corrosion rate measurement and potentiodynamic polarization measurement. The characteristics of Mg-Li-Al-Ce after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that Mg-Li-Al-Ce is more active than Mg and AZ31. The self-corrosion rate is found to be in the order: Mg-Li-Al-Ce < Mg < AZ31. It has been observed that the Mg-air battery based on Mg-Li-Al-Ce offers higher operating voltage, anodic efficiency and capacity than those with Mg and AZ31. SEM and EIS results show that the discharge product of Mg-Li-Al-Ce is loosely adhered to the alloy surface, and thus Mg-Li-Al-Ce could keep high discharge activity during discharge. (author)

El granito como piedra de construcción en Madrid: durabilidad y puesta en valor

OpenAIRE

Freire Lista, David Martín

2016-01-01

La tesis titulada “El granito como piedra de construcción en Madrid: durabilidad y puesta en valor” está estructurada en 6 artículos científicos publicados, 1 aceptado y otro en revisión, en diferentes revistas internacionales indexadas y un capítulo de un libro divulgativo. El uso de la piedra de construcción ha estado determinado por la proximidad de los recursos geológicos. Los materiales pétreos que históricamente se han utilizado en la Comunidad de Madrid provienen del Sistema Central Es...

Mastitis: Puesta al día

OpenAIRE

Espínola-Docio, Blanca; Costa-Romero, Marta; Díaz-Gómez, N. Marta; Paricio-Talayero, José M

2016-01-01

La mastitis es una de las principales causas de abandono evitable de la lactancia materna, con el aumento de la morbimortalidad infantil que ello supone, pero no hay uniformidad en los criterios diagnósticos ni terapéuticos. El diagnóstico de la mastitis aguda es fundamentalmente clínico, y, solo en determinados casos, está indicado el cultivo de leche. El drenaje del pecho es fundamental en el tratamiento, por lo que debe mantenerse la lactancia. Si persisten los síntomas o si existe mucha r...

Los nuevos desafios de la puesta en práctica de las políticas de saneamiento ambiental

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Horacio Alejandro Chamizo Garcia

2009-01-01

del saneamiento ambiental desde una perspectiva compleja. Así mismo, se evidencia el papel de las relaciones de agencia en condiciones de cuasimercados y su influencia en la conformación de redes de actores. Los hallazgos explican integradamente los principales factores que influyen durante la puesta práctica políticas públicas de gran relevancia para la salud de la población y la reducción de inequidades sociales.

Enfoque por competencias, ¿una respuesta al fracaso escolar?

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Philippe Perrenooud

2009-01-01

Full Text Available Son tiempos de reflexión sobre las competencias. Queda mucho por investigar acerca de sus posibilidades pero es cierto que, desde el punto de vista teórico, el enfoque por competencias se presenta como potente al complementar una pedagogía que, tradicionalmente, se ha centrado en las disciplinas y en los saberes. Pero también este enfoque aparece fuerte en el campo de la formación en la medida en que viene vinculado a las prácticas sociales y educativas, al trabajo pedagógico de los problemas educativos en las diferentes situaciones, a los proyectos que los educadores desean materializar en sus lugares de trabajo. Están por demostrar las expectativas puestas en el enfoque por competencias y este texto trata de pensar toda una serie de cuestiones relacionadas con su puesta en marcha en los contextos formativos.---------------------------------------------------------------------These are times for reflection on skills. There is much left to investigate on their possibilities but it is true that, from the theoretical point of view, the skill approach appears to be powerful by complementing a pedagogy which, tradicionally, has focused on the knowledge and disciplines. But this approach appears strongly in the training field as it is linked to the social and educational practices, to the pedagogic work on educative problems, to the different situations, to the project that teachers wish to materialize in the labor places. Still to be demonstrated are the expectations on the skills approach, and this text tries to think on a series of matters related with its set in motion in the learning contexts.

Efecto que se obtiene en la industria con la automatización del sistema de aire comprimido

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Jorge Torres Rodríguez

2016-06-01

Full Text Available Hoy en día todas las empresas tienen dentro de sus compromisos el cuidado del medio ambiente, por lo cual se tiene como objetivo reducir al mínimo el consumo de energía dentro de sus operaciones. En una empresa de manufacturación los principales equipos que consumen energía son los motores; principalmente los tipos cuadráticos (banda transportadoras, compresores, ventiladores y bombas. El control eficiente de los motores cuadráticos puede llegar a reducir el consumo eléctrico hasta un 20% a 30% en cada uno de estos equipos, lo cual convierte en una inversión rentable a futuro. En el anterior control de los compresores hacían arranques continuos cada cierto tiempo, (dependiendo de la señal del presostato lo cual originaba picos de corriente elevando los Kw/h, esto se debe a que los equipos de puesta en marcha son mediante dispositivos eléctricos y electromecánicos que no pueden controlar la velocidad de cada compresor. La presente investigación tiene como fin el diseño, instalación y puesta en marcha de un sistema de control descentralizado para la generación de aire comprimido. El nuevo sistema propuesto interconectará 4 compresores (2 VDP con arranque variador  de  frecuencia, 2 AD arranque directo. Este regulará la velocidad de 2 de los compresores, con el objetivo principal de ahorrar energía  para la planta y a su vez mejorar el sistema de funcionamiento  de los mismos. Todo el Sistema será controlado por PLC y su proceso será monitoreado en el Intouch (Software de monitoreo del Scada de la planta. Lo cual me generará ahorro en costos de mantenimiento de cada uno de los compresores a utilizar, ahorro de consumo de energía eléctrica y por ende  se contribuye  a cuidar el medio ambiente realizando un uso eficiente de cada uno de los equipos.

Ambient Air Quality Assessment of Al-Mansoriah Residential Area in the State of Kuwait

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S.M. Al-Salem

2009-12-01

Full Text Available Air quality data (ground level ozone (O3 , non-methane hydrocarbons (NMHC, methane (CH4 , nitrogen oxide (NO, nitrogen dioxide (NO2 , carbon monoxide (CO, hydrogen sulfide (H2 S and sulfur dioxide (SO2 of a Kuwaiti residential area, Al-Mansoriah, were analyzed to evaluate and determine: (a the exceedances of air quality from permissible limits set by the Kuwait Environment Public Authority (KUEPA, (b the diurnal patterns of air pollutants, (c the predominant sources of airborne pollutants in the surrounding area, and (d the ''weekend effect'' on ozone levels. The dataset covered the period of five consecutive years, from January 2000 to December 2004. High levels of ozone were witnessed; recording a number of exceedances. Inhabitants of Al-Mansoriah were exposed, during the period of study, to acute and chronic levels of SO2 . Concerning NMHC, the permissible limit (0.24 ppm- rolling average between 6-9 am, was violated in each of the monitoring years. NO diurnal pattern showed two distinct strong peaks during the months from October to March, in which the low solar radiation does not cause intense photochemical reactions, which lead to NO destruction. A clear H2 S source (considered as a primary one was witnessed from Kuwait city (Sharq district. The backed up sewage lines and maintenance work coinciding with study period clearly affected Al- Mansoriah. A clear "weekend effect", in terms of difference in levels occurring during midweek and weekends, was ascertained. The analysis suggests that Al-Mansoriah residential area should be considered a NOx sensitive region of Kuwait.

Cableado y puesta en marcha de puesto de laboratorio de automatización : mecanizado de taladro automatizado

OpenAIRE

Tena Fernández, Juan Diego

2011-01-01

El Proyecto Fin de Carrera titulado: “Cableado y puesta en marcha de puesto de laboratorio de automatización. Mecanizado de taladro automatizado”, trata sobre la construcción de un nuevo puesto de laboratorio para las practicas del área de automatización industrial de la Universidad Carlos III. El puesto de laboratorio consiste en una maquina-herramienta que realiza taladros de forma automática. El puesto está formado por una armario eléctrico y una maqueta. En el armario eléctrico se encuent...

Aluminum anode for aluminum-air battery - Part II: Influence of In addition on the electrochemical characteristics of Al-Zn alloy in alkaline solution

Science.gov (United States)

Park, In-Jun; Choi, Seok-Ryul; Kim, Jung-Gu

2017-07-01

Effects of Zn and In additions on the aluminum anode for Al-air battery in alkaline solution are examined by the self-corrosion rate, cell voltage, current-voltage characteristics, anodic polarization, discharge performance and AC impedance measurements. The passivation behavior of Zn-added anode during anodic polarization decreases the discharge performance of Al-air battery. The addition of In to Al-Zn anode reduces the formation of Zn passivation film by repeated adsorption and desorption behavior of In ion onto anode surface. The attenuated Zn passive layer by In ion attack leads to the improvement of discharge performance of Al-air battery.

Enhancing the Light-Extraction Efficiency of AlGaN Nanowires Ultraviolet Light-Emitting Diode by using Nitride/Air Distributed Bragg Reflector Nanogratings

KAUST Repository

Alias, Mohd Sharizal; Janjua, Bilal; Zhao, Chao; Priante, Davide; Alhamoud, Abdullah A.; Tangi, Malleswararao; Alanazi, Lafi M.; Alatawi, Abdullah A.; Albadri, Abdulrahman M.; Alyamani, Ahmed Y.; Ng, Tien Khee; Ooi, Boon S.

2017-01-01

The performance and efficiency of AlGaN ultraviolet light-emitting diodes have been limited by the extremely low light-extraction efficiency (LEE) due to the intrinsic material properties of AlGaN. Here, to enhance the LEE of the device, we demonstrate an AlGaN nanowires light-emitting diode (NWs-LED) integrated with nitride/air Distributed Bragg Reflector (DBR) nanogratings. Compared to a control device (only mesa), the AlGaN NWs-LED with the nitride/air DBR nanogratings exhibit enhancement in the light output power and external quantum efficiency (EQE) by a factor of ∼1.67. The higher light output power and EQE are attributed mainly to the multiple reflectances laterally for the transverse magnetic (TM)-polarized light and scattering introduced by the nanogratings. To further understand the LEE enhancement, the electrical field distribution, extraction ratio and polar pattern of the AlGaN NWs-LED with and without the nitride/air DBR nanogratings were analyzed using the finite-difference-time-domain method. It was observed that the TM-field emission was confined and scattered upward whereas the polar pattern was intensified for the AlGaN NWs-LED with the nanogratings. Our approach to enhance the LEE via the nitride/air DBR nanogratings can provide a promising route for increasing the efficiency of AlGaN-based LEDs, also, to functioning as facet mirror for AlGaN-based laser diodes.

Enhancing the Light-Extraction Efficiency of AlGaN Nanowires Ultraviolet Light-Emitting Diode by using Nitride/Air Distributed Bragg Reflector Nanogratings

KAUST Repository

Alias, Mohd Sharizal

2017-09-11

The performance and efficiency of AlGaN ultraviolet light-emitting diodes have been limited by the extremely low light-extraction efficiency (LEE) due to the intrinsic material properties of AlGaN. Here, to enhance the LEE of the device, we demonstrate an AlGaN nanowires light-emitting diode (NWs-LED) integrated with nitride/air Distributed Bragg Reflector (DBR) nanogratings. Compared to a control device (only mesa), the AlGaN NWs-LED with the nitride/air DBR nanogratings exhibit enhancement in the light output power and external quantum efficiency (EQE) by a factor of ∼1.67. The higher light output power and EQE are attributed mainly to the multiple reflectances laterally for the transverse magnetic (TM)-polarized light and scattering introduced by the nanogratings. To further understand the LEE enhancement, the electrical field distribution, extraction ratio and polar pattern of the AlGaN NWs-LED with and without the nitride/air DBR nanogratings were analyzed using the finite-difference-time-domain method. It was observed that the TM-field emission was confined and scattered upward whereas the polar pattern was intensified for the AlGaN NWs-LED with the nanogratings. Our approach to enhance the LEE via the nitride/air DBR nanogratings can provide a promising route for increasing the efficiency of AlGaN-based LEDs, also, to functioning as facet mirror for AlGaN-based laser diodes.

High temperature cyclic oxidation of Ti-Al based intermetallic in static laboratory air

International Nuclear Information System (INIS)

Astuty Amrin; Esah Hamzah; Nurfashahidayu Mohd Badri; Hafida Hamzah

2007-01-01

The objective of this study is to investigate the oxidation behaviour of binary γ-Ti Al based intermetallics with composition (at%) of 45A, 48Al and 50 Al, and ternary alloys of Ti-48Al containing 2Cr and 4Cr. Thermal cyclic oxidation was conducted discontinuously at temperatures of 700 degree Celsius and 900 degree Celsius in static laboratory air. Optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and X-ray diffraction (XRD) techniques were employed for the analysis. SEM examination of cross-sectional samples using secondary electron and line-scan analysis after exposure at 700 degree Celsius showed that non-adherent oxides scales formed due to the spallation caused by cyclic condition. For exposure to 900 degree Celsius, only binary alloys exhibited breakaway oxidation whereas the oxide scales formed on the ternary alloys were well-adhered on the substrate alloy. Overall, exposure at 900 degree Celsius resulted in thicker and harder oxide scales and addition of Cr seems to improve oxidation resistance of Ti-Al based intermetallics at higher temperature. (author)

PET/CT en Urología Oncológica: Puesta al día

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David Ladrón de Guevara, Dr.

2018-03-01

Full Text Available Resumen: A pesar del amplio uso actual del PET/CT en patología oncológica, su expansión en urología ha sido bastante más lenta, debido principalmente a la excreción fisiológica de la F18-Fluorodeoxiglucosa (F18-FDG por vías urinarias y a la baja captación de F18-FDG de varios de los tumores urológicos, principalmente renales y prostáticos. Debido a las mejoras técnicas del PET/CT y al desarrollo de nuevos radiotrazadores distintos al F18-FDG, su uso en oncología urológica ha aumentado en los últimos años. En cáncer testicular, es el método de elección en masas residuales post quimioterapia. En cáncer vesical muestra un aumento progresivo en su uso tanto para etapificación como para seguimiento post tratamiento. En cáncer renal es útil en sospecha de recidiva local y vigilancia post tratamiento. En cáncer de próstata, gracias al advenimiento de radiotrazadores específicos como la F18/C11-Colina y G68-PSMA, es de amplio uso en pacientes que se han realizado tratamiento curativo y que presentan recidiva bioquímica. El desarrollo de nuevos radiotrazadores y de la técnica híbrida PET/MR posiblemente potenciarán aún más las aplicaciones en urología oncológica. Summary: In spite of extensive use of PET/CT in general oncology, its expansion in urological oncology has been quite slower, due principally to F18-Fluorodeoxiglucosa (F18-FDG physiological urinary excretion and low F18-FDG uptake of several of urological tumors, mainly renal and prostatic tumors. Owing to PET/CT technical improvements and the development of new radiopharmaceuticals different than F18-FDG, the use of PET/CT in oncological urology has increase last years. In testis cancer, it represents the best choice for assessment of residual mass post chemotherapy. Its clinical use has progressively increased for staging and follow up of patients with bladder cancer. In renal cancer, PET/CT is useful for suspicion of local relapse and surveillance. In

High-temperature oxidation behavior of Ti3AlC2 in air

Institute of Scientific and Technical Information of China (English)

XU Xue-wen; LI Yang-xian; ZHU Jiao-qun; MEI Bing-chu

2006-01-01

Not only the isothermal oxidation behaviors at 900-1 300 ℃ for 20 h in air of bulk Ti3AlC2 with 2.8% TiC which was sintered by hot pressing with the additive of silicon,but also the cyclic oxidation behavior at 1 100-1 300 °C for 30 cycles,were investigated by using TG,XRD,SEM. The isothermal and cyclic oxidation behaviors generally follow a parabolic rate law. The parabolic rate constants of the former increased from 1.39×10-10 kg2/(m4·s) at 900 ℃ to 5.56×10-9 kg2/(m4·s) at 1 300 ℃. The calculated activation energy is 136.45 kJ/mol. The oxidation products are á-Al2O3 and little TiO2 at 900-1 000 ℃,however when the temperature is raised up to 1 200 ℃,TiO2 partially reacts to Al2TiO5,and the reaction is completed at 1 300 ℃. This demonstrates that Ti3AlC2 has excellent oxidation resistance and good thermal shock because the dense continuous oxide scale consists of mass á-Al2O3 and little TiO2 and/or Al2TiO5. Generally,the oxide scale is grown by the inward diffusion of O2- and the outward diffusion of Ti4+ and Al3+.

Temperature Mapping of Air Film-Cooled Thermal Barrier Coated Surfaces Using Cr-Doped GdAlO3 Phosphor Thermography

Science.gov (United States)

Eldridge, Jeffrey I.; Shyam, Vikram; Wroblewski, Adam C.; Zhu, Dongming; Cuy, Michael D.; Wolfe, Douglas E.

2016-01-01

It has been recently shown that the high luminescence intensity from a Cr-doped GdAlO3 (Cr:GdAlO3) thermographic phosphor enables non-rastered full-field temperature mapping of thermal barrier coating (TBC) surfaces to temperatures above 1000C. In this presentation, temperature mapping by Cr:GdAlO3 based phosphor thermometry of air film-cooled TBC-coated surfaces is demonstrated for both scaled-up cooling hole geometries as well as for actual components in a burner rig test environment. The effects of thermal background radiation and flame chemiluminescence on the measurements are investigated, and advantages of this method over infrared thermography as well as the limitations of this method for studying air film cooling are discussed.

Ciclo reproductivo de Liolaemus gracilis Bell, 1843 (Iguanidae: Tropidurinae en las dunas costeras de Buenos Aires, Argentina

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Vega, Laura Estela

2005-02-01

Full Text Available Estudiamos la fenología y edad de madurez reproductiva y el tamaño y la frecuencia de la puesta de una población de Liolaemus gracilis de las dunas costeras de Buenos Aires, Argentina. Examinamos las gónadas de 93 ejemplares coleccionados mensualmente a lo largo de un año en la localidad de Mar del Sur (provincia de Buenos Aires y medimos 11 caracteres morfométricos en 39 adultos en búsqueda de dimorfismo sexual. Las hembras se consideraron maduras si poseían folículos yemados mayores a 2 mm, o huevos oviductales, u oviductos claramente distendidos. En los machos los indicadores de madurez sexual fueron la presencia de testículos agrandados y el estado convoluto de los epidídimos, midiéndose el ancho y largo del testículo izquierdo en cada uno. L. gracilis exhibió un patrón reproductivo estacional con características del tipo parcial de otoño. El tamaño medio de las hembras en actividad reproductiva fue de 48,9 mm ± 3,5 (largo hocico-cloaca (n = 19 y la menor madura sexualmente midió 43,8 mm. El tamaño de la puesta varió de 4 a 6 huevos ( X = 4,75 ± 0,95, n = 4. El macho de menor tamaño con testículos agrandados midió 40,5 mm. (largo hocico-cloaca. Tanto los machos como las hembras estuvieron reproductivamente activos desde comienzos del otoño hasta comienzos del verano. Las hembras producirían una puesta por año entre fines de la primavera y comienzos del verano y las crías nacerían a mediados de esta estación. Encontramos dimorfismo sexual en la mayor distancia entre los miembros anteriores y posteriores de las hembras y en la mayor longitud de la cabeza, tibio-fíbula y pie de los machos. We studied the reproductive phenology, size at maturity, frequency and clutch size of a lizard population of Liolaemus gracilis from coastal sand dunes of Buenos Aires, Argentina. We examined 93 specimens collected monthly throughout a year in the locality of Mar del Sur (Buenos Aires province and measured 11 morphometric

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...

Aportaciones a la transición del hiero I al hierro II en el centro de la cuenca del udero

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Manuel GARCÍA ALONSO

2009-10-01

Full Text Available En la diversidad de publicaciones que se ponen al alcance del investigador, y que son referidas a la Edad del Hierro, entendida de una manera amplia, se viene observando, en el manejo terminológico más bien, una serie de cuestiones que quedan latentes entre las diferentes tomas de postura; pero que, salvo excepciones, no dan pie a una discusión o puesta en común de las mismas, y que entendemos son de capital importancia para la zona objeto de la presente comunicación.

IDENTIFICACIÓN, EVALUACIÓN Y PUESTA EN VALOR DE UN PATRIMONIO HIDRÁULICO SINGULAR: LAS GALERÍAS DRENANTES DE LA CUENCA DEL JÚCAR

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Emilio Iranzo García

2010-01-01

Full Text Available De los bienes que conforman el patrimonio cultural de España, los relacionados con el manejo de los recursos hídricos, ya sean destinados al riego o al abastecimiento humano, han sido históricamente y siguen siendo elementos mínimamente valorados y poco estudiados en el seno de la investigación histórica, artística y etnológica. Sin embargo, estas arquitecturas del agua y conocimientos ancestrales para la gestión de la escasez hídrica juegan un papel importante en la configuración de buena parte de nuestros paisajes; paisajes a los que desde la disciplina geográfica nos tratamos de aproximar. El conocimiento del medio natural, la construcción de artilugios y el uso de determinados artefactos para la captación y distribución del agua son, sin duda alguna, un patrimonio de la sociedad que los ha generado y los ha mantenido. Uno de los elementos más singulares por su antigüedad, concepción técnica y arquitectura son las galerías drenantes o foggaras, un sistema de captación de aguas subterráneas mediante un túnel excavado horizontalmente en el subsuelo. Su identificación, estudio y puesta en valor puede convertirse en un ejercicio efectivo, en primer lugar para la salvaguarda de las galerías como bien patrimonial, en segundo lugar para comprender el origen de un paisaje de regadío y en tercer lugar como estrategia para el desarrollo socioeconómico de un territorio.

Una mirada al surgimiento del turismo en Pátzcuaro

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José Manuel Martínez Aguilar

2017-01-01

Full Text Available El turismo en Pátzcuaro, como actividad económica, tuvo su origen y primer impulso desde finales del siglo XIX, a partir de la puesta en marcha del tramo ferroviario de Morelia a Pátzcuaro, cuando distintos empresarios apostaron por invertir en servicios de hospedaje, alimentación y transporte destinados al turismo. Sin embargo, la inestabilidad de la Revolución Mexicana cortó la inercia del desarrollo turístico. Fue hasta que el General Lázaro Cárdenas del Rio tomó la gubernatura del estado que se implementaron estrategias, se decretaron leyes y se hicieron mejoras en la ciudad, con el objeto de que ésta fuera un foco de atracción para el turismo nacional y extranjero, y que permitiera a la población tener mayores ingresos económicos.

Funciones parentales: Indagación sobre las actitudes hacia el juego infantil y la puesta de límites en un grupo de padres. Elaboración de una escala para evaluarlas Parental functions: Inquiry on attitudes towards children's game and putting limits on group of parents. Development of a scale to evaluate them

Directory of Open Access Journals (Sweden)

Graciela Paolicchi

2011-12-01

Full Text Available Con la investigación UBACyT (2010-2012 "Juego, apego y poblaciones vulnerables. El juego como facilitador del desarrollo infantil y su relación con las modalidades de apego en poblaciones vulnerables", se comenzó a construir una escala para evaluar las actitudes de los padres hacia el juego infantil y otros tópicos como la puesta de límites y la calidad vincular con sus hijos. Solidariamente a esta tarea, se implementan Talleres a padres -en el marco del Programa de Extensión Universi- taria "Juegotecas Barriales"- en que se que actualizan, entre otros temas, el lugar y el valor del juego en la infancia. Con el fin de diagnosticar la percepción parental sobre el juego infantil y la puesta de límites, al inicio de cada taller se administró una escala tipo Likert. En el presente escrito se presenta esta metodología de carácter cuantitativo, así como se sintetizan algunos de los resultados derivados del uso de este instrumento en un grupo de 104 padres de la Ciudad de Buenos Aires, que corresponde a la primera etapa de la construcción de la escala y otro grupo de 367 padres de la ciudad de Salta, sobre la que se aplicó la escala para continuar con el proceso de construcción y ajuste de los items.With the research UBACyT (2010-2012 "Game, attachment and vulnerable populations. The game as a facilitator of child development and its relation with patterns of affection in vulnerable populations" began to build upa a scale to assess attitudes of parentes towards children´s play and other topics such as setting limits and quality links with their children. The project is consistent with the University Extension Program "Neighborhood playground" in which workshops are deployed to parents whom updates, among other topics, the place and value of playing in childhood. In order to diagnose the parental perception of children's game and a limits setting, at the beginning of each workshop were given a Likert's scale. This paper presents the

Effect of ion plating TiN on the oxidation of sputtered NiCrAlY-coated Ti3Al-Nb in air at 850-950 C

International Nuclear Information System (INIS)

Rizzo, F.C.; Zeng, C.; Chinese Academy of Sciences, Shenyang; Wu, W.

1998-01-01

A single sputtered NiCrAlY coating and a complex coating of inner ion-plated TiN and outer sputtered NiCrAlY were prepared on the intermetallic compound Ti 3 Al-Nb. Their oxidation behavior was examined at 850, 900, and 950 C in air by thermal gravimetry combined with XRD, SEM, and EDAX. The results showed that Ti 3 Al-Nb followed approximately parabolic oxidation, forming an outer thin Al 2 O 3 -rich scale and an inner TiO 2 -rich layer doped with Nb at the three temperatures. The TiO 2 -rich layer doped with Nb dominated the oxidation reaction. The single NiCrAlY coating did not follow parabolic oxidation exactly at 850 and 950 C, but oxidized approximately in a parabolic manner, because the instantaneous parabolic constants changed slightly with time. Besides the Al 2 O 3 scale, TiO 2 formed from the coating surface at the coating-substrate interface. The deterioration of the coating accelerated with increasing temperature. The NiCrAlY-TiN coating showed two-stage parabolic oxidation at 850 and 900 C, and an approximate parabolic oxidation at 950 C. The TiN layer was effective as a barrier to inhibit coating-alloy interdiffusion

Madres y médicos en torno a la cuna: Ideas y prácticas sobre el cuidado infantil (Buenos Aires, 1930-1945) Mothers and doctors around the cradle: Practices and ideas about the child care. (Buenos Aires, 1930-1945)

OpenAIRE

María José Billorou

2007-01-01

En la ciudad de Buenos Aires, desde mediados de la década de 1930 con la creación de la Sociedad de Puericultura, se intensificó la acción desarrollada por la Dirección de Protección a la Primera Infancia en el seno de la Asistencia Pública desde 1908. La disminución de la mortalidad infantil, objetivo central de la labor de ambas instituciones, se había logrado a través de la puesta en práctica de un programa de protección infantil. Los Dispensarios e Institutos de Puericultura se convirtier...

Oxidation of (Cr,Ti)_2AlC Compounds at 700-1000 °C for One Year in Air

International Nuclear Information System (INIS)

Lee, Jae Chun; Won, Sung Bin; Lee, Dong Bok; Park, Sang Whan

2013-01-01

(Cr,Ti)_2AlC compounds were synthesized by hot pressing, and oxidized at 700, 850, and 1000 °C in air for up to one year. They consisted of Ti-incorporated Cr_2AlC phase, Ti-rich phase, and Cr-rich phase. The formed scales divided into a uniform oxide layer and oxide nodules. The uniform oxide layer consisted primarily of a thin Al_2O_3 scale. The oxide nodules that originated from the Ti-rich phase consisted of TiO_2, which grew by both the outward diffusion of Ti"4+ ions and inward diffusion of O"2‒ ions. Chromium did not appreciably enter the oxide scale. Instead, it existed in the Ti-incorporated Cr_7C_3 sublayer after oxidation. (Cr,Ti)_2AlC compounds had good oxidation resistance, because of formation of the Al_2O_3 barrier layer.

Methodology for evaluating the grounding system in electrical substations; Metodologia para la evaluacion del sistema de puesta a tierra en subestaciones electricas

Energy Technology Data Exchange (ETDEWEB)

Torrelles Rivas, L.F [Universidad Nacional Experimental Politecnica: Antonio Jose de Sucre (UNEXPO), Guayana, Bolivar (Venezuela)]. E-mail: torrellesluis@gmail.com; Alvarez, P. [Petroleos de Venezuela S.A (PDVSA), Maturin, Monagas (Venezuela)]. E-mail: alvarezph@pdvsa.com

2013-03-15

The present work proposes a methodology for evaluating grounding systems in electrical substations from medium and high voltage, in order to diagnose the state of the elements of the grounding system and the corresponding electrical variables. The assessment methodology developed includes a visual inspection phase to the elements of the substation. Then, by performing measurements and data analysis, the electrical continuity between the components of the substation and the mesh ground is verified, the soil resistivity and resistance of the mesh. Also included in the methodology the calculation of the step and touch voltage of the substation, based on the criteria of the International IEEE standards. We study the case of the 115 kV Pirital Substation belonging to PDVSA Oriente Transmission Network. [Spanish] En el presente trabajo se plantea una metodologia para la evaluacion de sistemas de puesta a tierra en subestaciones electricas de media y alta tension, con la finalidad de diagnosticar el estado de los elementos que conforman dicho sistema y las variables electricas correspondientes. La metodologia de evaluacion desarrollada incluye una fase de inspeccion visual de los elementos que conforman la subestacion. Luego, mediante la ejecucion de mediciones y analisis de datos, se verifica la continuidad electrica entre los componentes de la subestacion y la malla de puesta a tierra, la resistividad del suelo y resistencia de la malla. Se incluye tambien en la metodologia el calculo de las tensiones de paso y de toque de la subestacion, segun lo fundamentado en los criterios de los estandares Internacionales IEEE. Se estudia el caso de la Subestacion Pirital 115 kV perteneciente a la Red de Transmision de PDVSA Oriente.

Factores predictivos de la no adherencia al tratamiento de la tuberculosis en municipios del Área Metropolitana de Buenos Aires, Argentina

OpenAIRE

Silvina Arrossi; María Belén Herrero; Adriana Greco; Silvina Ramos

2012-01-01

El objetivo de este estudio fue identificar las características sociodemográficas de los pacientes y las características del tratamiento que influyen en la no-adherencia al tratamiento antituberculoso. Se realizó un estudio de corte transversal, en el Área Metropolitana de Buenos Aires. Se encuestaron 38 pacientes que no adhirieron al tratamiento y 85 pacientes que adhirieron al tratamiento, diagnosticados durante el año 2007, residentes y atendidos en hospitales de municipios seleccionados. ...

Ionic Conductivity and Air Stability of Al-Doped Li₇La₃Zr₂O₁₂ Sintered in Alumina and Pt Crucibles.

Science.gov (United States)

Xia, Wenhao; Xu, Biyi; Duan, Huanan; Guo, Yiping; Kang, Hongmei; Li, Hua; Liu, Hezhou

2016-03-02

Li7La3Zr2O12 (LLZO) is a promising electrolyte material for all-solid-state battery due to its high ionic conductivity and good stability with metallic lithium. In this article, we studied the effect of crucibles on the ionic conductivity and air stability by synthesizing 0.25Al doped LLZO pellets in Pt crucibles and alumina crucibles, respectively. The results show that the composition and microstructure of the pellets play important roles influencing the ionic conductivity, relative density, and air stability. Specifically, the 0.25Al-LLZO pellets sintered in Pt crucibles exhibit a high relative density (∼96%) and high ionic conductivity (4.48 × 10(-4) S cm(-1)). The ionic conductivity maintains 3.6 × 10(-4) S cm(-1) after 3-month air exposure. In contrast, the ionic conductivity of the pellets from alumina crucibles is about 1.81 × 10(-4) S cm(-1) and drops to 2.39 × 10(-5) S cm(-1) 3 months later. The large grains and the reduced grain boundaries in the pellets sintered in Pt crucibles are favorable to obtain high ionic conductivity and good air stability. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy results suggest that the formation of Li2CO3 on the pellet surface is probably another main reason, which is also closely related to the relative density and the amount of grain boundary within the pellets. This work stresses the importance of synthesis parameters, crucibles included, to obtain the LLZO electrolyte with high ionic conductivity and good air stability.

Improved Thermally Grown Oxide Scale in Air Plasma Sprayed NiCrAlY/Nano-YSZ Coatings

International Nuclear Information System (INIS)

Daroonparvar, M.; Yajid, M.A.M.; Yusof, N.M.; Hussain, M.S.

2013-01-01

Oxidation has been considered as one of the principal disruptive factors in thermal barrier coating systems during service. So, oxidation behavior of thermal barrier coating (TBC) systems with nano structured and micro structured YSZ coatings was investigated at 1000 degree c for 24 h, 48 h, and 120 h. Air plasma sprayed nano-YSZ coating exhibited a tri modal structure. Microstructural characterization also demonstrated an improved thermally grown oxide scale containing lower spinels in nano-TBC system after 120 h of oxidation. This phenomenon is mainly related to the unique structure of the nano-YSZ coating, which acted as a strong barrier for oxygen diffusion into the TBC system at elevated temperatures. Nearly continues but thinner Al 2 O 3 layer formation at the NiCrAlY/nano-YSZ interface was seen, due to lower oxygen infiltration into the system. Under this condition, spinels formation and growth on the Al 2 O 3 oxide scale were diminished in nano-TBC system compared to normal TBC system.

“implementación de un sistema de aire comprimido para un taller de mecánica automotriz”

OpenAIRE

Zhimnaycela Reino, Carlos Fernando; Camposano, Filian

2013-01-01

En este proyecto de graduación se encontrara una guía práctica para la instalación, puesta en marcha y mantenimiento de un sistema de aire comprimido. Para calcular el consumo total del sistema, se hacen las estimaciones de equipos a utilizar, la forma que debe determinarse la unidad compresora con su respectivo factor de seguridad en el caso de aumentar el consumo del sistema. Se diseña la red de tuberías, se calcula el diámetro de la tubería, la caída de presión y selecciona la tuberí...

La puesta en valor de la Huaca Pucllana y su repercusión en la conciencia turística de la comunidad de Miraflores

OpenAIRE

Mendoza Cáceres, Angélica Maciel

2015-01-01

El presente trabajo de investigación busca medir la evolución de conciencia turística de los vecinos de la comunidad de Miraflores a través del tiempo y como este ha influido en el desarrollo de la Huaca Pucllana, como producto turístico y que la puesta en valor no es un gasto sino una inversión a largo plazo viable y auto sostenible y es ejemplo tanto para otras comunidades urbanas como para poblados rurales de nuestro país, y puede fomentar en los moradores el deseo de gestionar los espacio...

Análisis de las estrategias de vinculación de los varones al Programa de Salud Sexual y Procreación Responsable de la municipalidad de La Plata

OpenAIRE

Rodríguez Moreno, Sandra Milena

2014-01-01

La responsabilidad de las decisiones en la salud sexual y reproductiva ha sido puesta en mayor parte sobre las mujeres, invisibilizando las relaciones de poder que se viven al interior de las parejas; por esta razón surge el interés de analizar las estrategias de vinculación de los varones que se implementan desde el Programa de Salud Sexual y Procreación Responsable PSSyPR. En este aspecto, este trabajo propuso estudiar la temática, con el fin de aportar elementos que permitan mejorar sus re...

Study on the isothermal oxidation behavior in air of Ti3AlC2 sintered by hot pressing

Institute of Scientific and Technical Information of China (English)

XU Xuewen; LI Yangxian; MEI Bingchu; ZHU Jiaoqun; LIU Heyan; QU Jingping

2006-01-01

The isothermal oxidation behavior at 900―1300℃ for 20 h in air of bulk Ti3AlC2 with 2.8 wt% TiC sintered by means of hot pressing was investigated in the work. The isothermal oxidation behavior generally followed a parabolic rate law. The parabolic rate constants increased from 1.39×10-10 kg2·m-4·s-1 at 900℃ to 5.56×10-9 kg2·m-4·s-1 at 1300℃. The calculated activation energy was 136.45 kJ/mol. It was demonstrated that Ti3AlC2 had excellent oxidation resistance due to the continuous, dense and adhesive protect scales consisted of a mass of α-Al2O3 and a little of TiO2 and/or Al2TiO5. In principle, the oxide scale was grown by the inward diffusion of O2- and the outward diffusion of Ti4+ and Al3+. The rapid outward diffusion of cations usually resulted in the formation of cracks, gaps, and holes.

Medición "in situ" de la permeabilidad al aire del hormigón: status quo Concrete air permeability "in situ "test status quo

Directory of Open Access Journals (Sweden)

Luis Ebensperger

2010-01-01

Full Text Available Los autores han estado involucrados en la creación y primeros ensayos y desarrollos del llamado "Método Torrent" para medir la permeabilidad al aire del hormigón. Transcurridos más de 15 años de ese trabajo fundacional, el artículo presenta una revisión de la evolución y estado de situación del método, incluido como Norma Oficial Suiza en 2003. Se presentan ejemplos de su aplicación en laboratorio y en obras (puentes, túneles, etc., con datos de valores medidos, provenientes de distintos países del mundo. Se presentan correlaciones entre el coeficiente de permeabilidad al aire kT y otros indicadores de durabilidad, tales como la migración de cloruros (ASTM C1202 y la penetración de agua a presión (EN 12390-8 o por capilaridad. Finalmente se discuten sus perspectivas de uso futuro, como herramienta de control de calidad de estructuras nuevas, con las importantes implicancias que ello acarreará, así como de diagnóstico de estructuras existentes.The authors have been involved in the creation, preliminary tests and development of the "Torrent Method", which is intended to test air permeability in concrete. It's been more than 15 years since such foundational research and, now, this paper presents a review of the evolution and current situation of the Method, included in the Switzerland standards in 2003. Application examples conducted in laboratory and civil works (bridges, tunnels, and so on are introduced, including data from different countries worldwide. Correlations between the air permeability coefficient kT and other durability indicators, such as chloride migration (ASTM C1202, penetration of water under pressure (EN 12390-8 or capillary action are presented. Finally the future prospective uses are discussed, as quality control tool for new structures, considering relevant implications they would lead to, as well as the diagnosis on existing structures.

Un método rápido y no-destructivo para medir la permeabilidad al aire del hormigón

Directory of Open Access Journals (Sweden)

Torrent, R. J.

1999-06-01

Full Text Available New device for non-destructive test. It is designed for "in situ" measurement of the impermeability to air of a concrete coating. The system is based on creating a vacuum inside a cell placed on its surface, and to measure how long does it take for the pressure to be back to the atmospheric value. The characteristic aspects of the method are: a cell with an inward chamber and a regulator to keep the pressure in balance inside this central chamber (measurement and in the surrounding chamber (preservation ring. This ensures a single air flow direction towards the central chamber, avoiding any spurious transversal flow. The data of the measurement are processed by a microprocessor that indicates the permeability coefficient value at the end of the test which lasts 2 to 12 minutes. Results on coatings of different quality obtained through this technique are presented, which show an excellent correlation with values obtained on specimens using Cembureau method for permeability to oxigen imperviousness.

Se presenta un nuevo dispositivo de ensayo no destructivo, diseñado para la medición "in situ " de la permeabilidad al aire del recubrimiento de hormigón. Se basa en crear vacío dentro de una celda colocada sobre la superficie del mismo y en medir la velocidad con que la presión retorna al valor atmosférico. Aspectos característicos del método son: una celda con doble cámara y un regulador que equilibra la presión en la cámara central (de medicióny en la cámara exterior (anillo de guarda. Esto asegura un flujo unidireccional de aire hacia la cámara central, eliminando todo flujo espúreo transversal. Los datos de la medición son procesados por un microprocesador que indica el valor del coeficiente de permeabilidad al finalizar el ensayo, que dura de 2 a 12 minutos. Se presentan resultados obtenidos con esta técnica sobre recubrimientos de distinta calidad, que muestran una excelente correlación con los valores obtenidos

Estudio comparativo de los diseños de dos programas públicos de apoyo al manejo forestal comunitario en México y Guatemala

OpenAIRE

Michel, Marike

2009-01-01

Análisis del diseño de dos programas públicos de apoyo al manejo forestal comunitario en dos países de la región mesoamericana, México y Guatemala, con el propósito de entender mejor los factores que han generado la definición de un problema público alrededor de los bosques comunitarios y que han permitido su puesta en la agenda pública. Capítulo I. comparación de los contextos rurales de México y de Guatemala en el siglo XX. -- Capítulo II. Marco teórico de las políticas públicas. -- Capí...

Análisis de la permeabilidad al aire de filtros de protección respiratoria

OpenAIRE

Garcia Torrent, Javier; Grima Olmedo, Carlos; Ramírez Gómez, Álvaro

2013-01-01

Los filtros que forman los equipos de protección respiratoria están constituidos por una serie de capas formadas por fibras entrecruzadas, orientadas al azar, que reducen los espacios libres en la dirección del flujo de aire inspiratorio. La estructura tridimensional formada permite orificios mayores que las partículas a retener con el fin de no provocar una excesiva caída de presión. Cuando los orificios se reducen significativamente o se obstruyen por la deposición excesiva de partículas ca...

Air sparging as a supporting measure to redevelopment of a LCFC-contaminated industrial site; Air-Sparging als begleitende Sanierungsmassnahme an einem LCKW-kontaminierten Industriestandort

Energy Technology Data Exchange (ETDEWEB)

Breh, W.; Suttheimer, J. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie; Holub, B. [G.U.T Linz (Austria)

1998-12-31

On a company ground in Vorchdorf, Austria, from the 23{sup rd} to 26{sup th} of July 1996 an air-sparging experiment has been carried out as a supporting measure to a running redevelopment of an LCKW-contamination case. On this occasion compressed air, from which the oil had been extracted, was blown into the contaminated aquifer through a well with a maximum excess pressure of 0,6 MPa. The blowing-in of compressed air caused a mobilisation of the harmful substances in the ground water and the soil air. As a result circa 2,7 kg LCKW could be removed from the underground through neighbouring ground water and soil air wells. For the observed period of time this meant a tripling of the rate of discharge. On the basis of the obtained data we suggested a routine interval of blowing in compressed air into the well 1516. A blowing-in of compressed air into the highly contaminated wells 1617 and 1625 can not be realised until the construction of upstream situated injection wells, because of the danger of an uncontrollable spread of the harmful substances. (orig.) [Deutsch] Auf einem Firmengelaende in Vorchdorf, Oesterreich, wurde vom 23.07. bis 26.07.1996 ein Air-Sparging-Versuch als unterstuetzende Massnahme zur laufenden hydraulisch-pneumatischen Sanierung eines LCKW-Schadensfalles durchgefuehrt. Hierbei wurde entoelte Druckluft ueber einen Brunnen mit einem maximalen Ueberdruck von 600 mbar in den kontaminierten Aquifer eingeblasen. Die Drucklufteinblasung fuehrte zu einer Mobilisierung von Schadstoffen im Grundwasser und in der Bodenluft, so dass ueber benachbarte Grundwasser- und Bodenluftfoerderbrunnen ca. 2,7 kg LCKW aus dem Untergrund entfernt werden konnten. Fuer den Beobachtungszeitraum bedeutet dies eine Verdreifachung des Schadstoffaustrags. Aufgrund der gewonnenen Daten wird ein routinemaessiger Intervallbetrieb der Drucklufteinblasung in einen der Brunnen vorgeschlagen. Fuer zwei kontaminierte Brunnen ist eine Drucklufteinblasung wegen der Gefahr einer

Performance e identidad en la fiesta "carnavalesca" de la Virgen de la Candelaria en Puno : la puesta en escena de dos mundos que entran en tensión

OpenAIRE

Tito Mamani, Charo

2012-01-01

La problemática de la identidad y performance en una ―puesta en escena‖como lo es la fiesta de la Candelaria en Puno nos muestra todo un mundo de encuentros y desencuentros, de diálogo y de tensiones a la vez. Pues estas construcciones colectivas de identidad local– las identidades son tanto hegemónicas como subalternas; originarias, mestizas o modernas– buscan mecanismos de auto-afirmación situados en un espacio y en un tiempo determinado asignado por este magnífico evento como es la fies...

Operation of ohmic Ti/Al/Pt/Au multilayer contacts to GaN at 600 °C in air

Science.gov (United States)

Hou, Minmin; Senesky, Debbie G.

2014-08-01

The high-temperature characteristics (at 600 °C) of Ti/Al/Pt/Au multilayer contacts to gallium nitride (GaN) in air are reported. Microfabricated circular-transfer-line-method test structures were subject to 10 h of thermal storage at 600 °C. Intermittent electrical characterization during thermal storage showed minimal variation in the contact resistance after 2 h and that the specific contact resistivity remained on the order of 10-5 Ω-cm2. In addition, the thermally stored multilayer contacts to GaN showed ohmic I-V characteristics when electrically probed at 600 °C. The microstructural analysis with atomic force microscopy showed minimal changes in surface roughness after thermal storage. Observations of the thermochemical reactions after thermal storage using Auger electron spectroscopy chemical depth profiling showed diffusion of Pt and minimal additional Al oxidation. The results support the use of Ti/Al/Pt/Au multilayer metallization for GaN-based sensors and electronic devices that will operate within a high-temperature and oxidizing ambient.

Diseño e implementación de instalación électrica, electromecánica y sistema de puesta a tierra para el Catamaran Ocean Spray

OpenAIRE

Moreira Mite, Enrique Francisco; Camacho Delgado, Ricardo Javier

2012-01-01

Diseño e implementación de implementación de instalación eléctrica y puesta a tierra de una embarcación tipo   Catamaran. Siendo el turismo una fuente de ingreso económico muy importante para el país especialmente en las islas Galápagos, la asociación de armadores de Galápagos se encuentran en la necesidad de ampliar los medios para un mejor servicio a los turistas en los lugares de visita dentro de las islas, se proponen construir nuevas embarcaciones que cumplan con todas las seguridad...

Diseño, construcción y puesta a punto de un banco de pruebas para el estudio del golpe de ariete en instalaciones hidráulicas

OpenAIRE

Calonge Hervás, Cynthia María

2016-01-01

El objetivo del presente trabajo sobre el diseño, construcción y puesta a punto de una instalación para ensayos de golpe de ariete es profundizar en el estudio de dicho fenómeno. En el documento se describe de manera teórica el golpe de ariete, los efectos que produce y las aplicaciones que tiene. Se incluyen los cálculos y los bocetos del diseño de la instalación. Para ello, se aplican conocimientos de las asignaturas de la rama Fluidomecánica y de CAD. Contiene también ...

Intrinsic ductility and environmental embrittlement of binary Ni3Al

International Nuclear Information System (INIS)

George, E.P.; Liu, C.T.; Pope, D.P.

1993-01-01

Polycrystalline, B-free Ni 3 Al (23.4 at.% Al), produced by cold working and recrystallizing a single crystal, exhibits room temperature tensile ductilities of 3-5% in air and 13-16% in oxygen. These ductilities are considerably higher than anything previously reported, and demonstrate that the 'intrinsic' ductility of Ni 3 Al is much higher than previously thought. They also show that the moisture present in ordinary ambient air can severely embrittle Ni 3 Al (ductility decreasing from a high of 16% in oxygen to a low of 3% in air). Fracture is predominantly intergranular in both air and oxygen. This indicates that, while moisture can further embrittle the GBs in Ni 3 Al, they persist as weak links even in the absence of environmental embrittlement. However, they are not 'intrinsically brittle' as once thought, since they can withstand relatively large plastic deformations prior to fracture. Because B essentially eliminates environmental embrittlement in Ni 3 Al - and environmental embrittlement is a major cause of poor ductility in B-free Ni 3 Al - it is concluded that a significant portion of the so-called B effect must be related to suppression of moisture-induced environmental embrittlement. However, since B-doped Ni 3 Al fractures transgranularly, whereas B-free Ni 3 Al fractures predominantly intergranularly, B must have the added effect that it strengthens the GBs. A comparison with the earlier work on Zr-doped Ni 3 Al shows that Zr improves the ductility of Ni 3 Al, both in air and (and even more dramatically) in oxygen. While the exact mechanism of this ductility improvement is not clear at present, Zr appears to have more of an effect on (enhancing) GB strength than on (suppressing) environmental embrittlement

Capital psicológico: una puesta al día

OpenAIRE

Salessi, Solana Magalí

2017-01-01

En el marco de la psicología organizacional positiva, el capital psicológico ha sido definido como un estado psicológico positivo, caracterizado por tener confianza para asumir y llevar a cabo con éxito una tarea desafiante; hacer una atribución positiva sobre el resultado de la misma; perseverar en la búsqueda de los objetivos, redireccionando los esfuerzos hacia las metas en caso de ser necesario, y a pesar de estar acosado por los problemas, fortalecerse en la adversidad para alcanzar el é...

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.)

Experiencias de la instauración de normas relativas al contenido de plomo en aire y el agua, en los Estados Unidos de América Establishing lead in air and water standards in the United States of America

Directory of Open Access Journals (Sweden)

J Michael Davis

2003-01-01

Full Text Available En los Estados Unidos de América se ha logrado una disminución de la exposición a plomo de la población en general, gracias al establecimiento de diversas normas. En este artículo se destaca parte de los conocimientos adquiridos a través de la experiencia obtenida en este país en materia de plomo, en particular respecto al aire y al agua. Uno de los aspectos fundamentales es la posibilidad de contar con una base científica sólidamente establecida y claramente entendida, a partir de la cual se tomarán las medidas correspondientes. Los efectos secundarios de ciertas normas concernientes al aire ponen de manifiesto de qué manera los esfuerzos orientados a solucionar un problema pueden aportar beneficios en otras áreas, si bien pueden surgir consecuencias no deseadas, debido a la falta de previsión y de evaluación. Asimismo, en este documento se discuten las diferencias entre los enfoques centralizados y los descentralizados para el manejo de la exposición a plomo.Lead regulations and standards have resulted in a lower exposure to lead in the general population of the United States of America. This paper highlights some of the know-how developed through lead-containing experiences, particularly regarding lead content in air and water. The availability of a solid and clear scientific knowledge is central to the success of these policies. Collateral effects of some air-related standards show the extent to which problem-oriented efforts may be beneficial in other areas, inasmuch as they may have untoward consequences if careful planning and evaluation are not considered. Finally, this paper presents a discussion of the differences between centralized and decentralized approaches to lead exposure control.

Administrative law judge as a watchdog for air quality; Bestuursrechter stelt zich terecht op als waakhond voor de luchtkwaliteit

Energy Technology Data Exchange (ETDEWEB)

Schutte-Postma, L.; Van Wee, B. [Faculteit Techniek, Bestuur en Management, Technische Universiteit Delft, Delft (Netherlands)

2005-12-01

Insight is given on the correctness of judgements of the judge for the administrative law in the Netherlands with regard to air quality and the discontinuation of related spatial planning and building and construction projects. Also attention is paid to the new Decree on Air Quality, including the regulation on balancing. This regulation implies that deteriorated air quality in one place must be compensated by improved air quality somewhere else. [Dutch] In de media worden de uitspraken van de Nederlandse bestuursrechter over luchtkwaliteit (en ruimtelijke plannen) verkeerd uitgelegd. Steeds zou de normstelling het probleem vormen. Juridische analyse van de rechterlijke uitspraken leert echter dat het steeds om oude, al in het verleden gemaakte, fouten gaat. In de 'vernietigde' plannen is onvoldoende met de luchtkwailteit rekening gehouden op het moment van vaststelling van die plannen door de gemeenteraad of de minister van Verkeer en Waterstaat. Steeds was sprake van gebrekkige informatie bij de afweging door gemeente of minister. Die plannen moeten daarom terecht 'overnieuw'. Het is vooral belangrijk dat overheden de regeling serieus nemen en onderzoek doen. Het nieuwe Besluit luchtkwaliteit, inclusief salderingsregeling, kan zulke fouten niet verbeteren.

Cementerio: lugar de memoria y museo al aire libre. Educación patrimonial en el ámbito escolar

Directory of Open Access Journals (Sweden)

Jenny González Muñoz

2017-08-01

Full Text Available El presente artículo pertenece a una propuesta en desarrollo, expresado con el objetivo de mostrar la importancia de incluir en la escuela el estudio del cementerio como lugar de memoria y museo al aire libre que permita comprender perspectivas del arte y simbolismo como sentido de pertenencia social hacia su salvaguarda, conservación y preservación. La metodología cualtitativo-interpretativa con observación directa, apoyo fotográfico y documental aborda el rol protagónico del cementerio como espacio común cultural, lugar de memoria (tomando las palabras de Pierre Nora que busca recordar al que murió en los que viven, para su perpetuidad. Narra el desarrollo social de la localidad a la que pertenece desde monumentos memoriales susceptibles a ser admirados y estudiados contribuyendo al impulso de la salvaguarda, conservación y preservación del patrimonio cultural material, siendo la educación en la escuela elemento de sensibilización hacia el cementerio como lugar de la identidad de sus habitantes.

Propuesta de adaptación al sistema de créditos (ECTS de la asignatura "El mundo de la Energía" de la diplomatura de maestro

Directory of Open Access Journals (Sweden)

Ana María VÁZQUEZ

2005-01-01

Full Text Available En el presente trabajo se presenta una propuesta de adaptación de la asignatura "El Mundo de la Energía" al sistema de créditos (ECTS del espacio Europeo de enseñanza superior. El programa de la asignatura, vigente desde 1991, no se ha modificado, lo que esta propuesta modifica no es el programa de la asignatura, sino la metodología de impartición. La propuesta de adaptación al sistema de créditos ECTS que se presenta corresponde a la segunda parte de la asignatura: Energía y Sociedad, con una carga de 2,25 créditos del plan de estudios del 91. La metodología de enseñanza/aprendizaje se basa fundamentalmente en dos aspectos: el trabajo personal del alumno y la puesta en común del trabajo realizado.

Rapid ultrasound-induced transient-liquid-phase bonding of Al-50Si alloys with Zn interlayer in air for electrical packaging application.

Science.gov (United States)

Wang, Qian; Chen, Xiaoguang; Zhu, Lin; Yan, Jiuchun; Lai, Zhiwei; Zhao, Pizhi; Bao, Juncheng; Lv, Guicai; You, Chen; Zhou, Xiaoyu; Zhang, Jian; Li, Yuntao

2017-01-01

Al-50Si alloys were joined by rapid ultrasound-induced transient-liquid-phase bonding method using Zn foil as interlayer at 390°C in air, below the melt point of interlayer. The fracture of oxide films along the edge of Si particles led to contact and inter-diffusion between aluminum substrate and Zn interlayer, and liquefied Zn-Al alloys were developed. The width of Zn-Al alloys gradually decreased with increasing the ultrasonic vibration time due to liquid squeezing out and accelerated diffusion. A stage of isothermal solidification existed, and the completion time was significantly shortened. In the liquid metal, the acoustic streaming and ultrasonic cavitations were induced. As the process developed, much more Si particles, which were particulate-reinforced phases of Al-50Si, gradually migrated to the center of soldering seam. The highest average shear strength of joints reached to 94.2MPa, and the fracture mainly occurred at the base metal. Copyright © 2016 Elsevier B.V. All rights reserved.

Experiencias de la instauración de normas relativas al contenido de plomo en aire y el agua, en los Estados Unidos de América

Directory of Open Access Journals (Sweden)

Davis J Michael

2003-01-01

Full Text Available En los Estados Unidos de América se ha logrado una disminución de la exposición a plomo de la población en general, gracias al establecimiento de diversas normas. En este artículo se destaca parte de los conocimientos adquiridos a través de la experiencia obtenida en este país en materia de plomo, en particular respecto al aire y al agua. Uno de los aspectos fundamentales es la posibilidad de contar con una base científica sólidamente establecida y claramente entendida, a partir de la cual se tomarán las medidas correspondientes. Los efectos secundarios de ciertas normas concernientes al aire ponen de manifiesto de qué manera los esfuerzos orientados a solucionar un problema pueden aportar beneficios en otras áreas, si bien pueden surgir consecuencias no deseadas, debido a la falta de previsión y de evaluación. Asimismo, en este documento se discuten las diferencias entre los enfoques centralizados y los descentralizados para el manejo de la exposición a plomo.

Elaboración de un plan de empresa para la puesta en marcha y posterior desarrollo de una empresa de radiodifusión en la comarca de L'Horta

OpenAIRE

GALLENT PÉREZ, JOSÉ MANUEL

2013-01-01

[ES] Elaborar un plan de empresa para presentarlo a inversores y socios para la puesta en marcha y posterior desarrollo de una empresa de medios a través de radio, ofreciendo el servicio de radio fórmula (música comercial) para las localidades de la comarca de L'Horta. Queremos ofrecer un servicio de entretenimiento a través de radio, orientándonos a un tipo de oyente con un perfil de edad joven y a los que les guste la música comercial que más suene en cada momento, principalmente del tip...

El Apando y la puesta en crisis novelesca y fílmica de la racionalidad occidental como denuncia del sistema social

Directory of Open Access Journals (Sweden)

Darcie Doll

2016-12-01

Full Text Available El artículo propone que en las dos versiones de El Apando, la novela y el filme, se exhibe una puesta en crisis de los fundamentos de la racionalidad y sus correlatos totalizadores desde varios frentes: la escenificación de la perspectiva óptica del sujeto geometral, la crítica del discurso tradicional de la nación y el planteamiento del encierro carcelario como extensión de la cárcel que es el mundo. A través de diversas estrategias discursivas se produce una subversión de los códigos realistas, en el marco de una denuncia de la opresión y la violencia del sistema social contemporáneo. Los relatos nos introducen en lo que será, décadas más tarde, la representación del mundo del narcotráfico y las consecuencias de la globalización económica en América Latina.

SIMULACION DE LA PUESTA EN MARCHA DE UN REACTOR DE BIOPELÍCULA ANAEROBIA TIPO INTERCAMBIADOR DE CALOR

Directory of Open Access Journals (Sweden)

Ramiro Escalera Vásquez

2009-01-01

Full Text Available Se ha desarrollado un  modelo de reactor que considera la separación de fases microbianas dentro de un reactor anaerobio tipo intercambiador de calor, donde las bacterias acidogénicas predominan en la masa líquida recirculante y las heteroacetogénicas y metanogénicas lo hacen en la biopelícula adherida a las paredes. El modelo considera también las resistencias difusionales a la transferencia de masa ocasionadas por la capa laminar y la biopelícula. También se consideran las reacciones paralelas y consecutivas propias de la degradación anaerobia de compuestos orgánicos fácilmente biodegradables, por ejemplo, residuos industriales de altas concentraciones de carbohidratos. El modelo de reactor y las ecuaciones pseudo-analíticas para la estimación de los factores de efectividad, desarrolladas para otro tipo de bioreactores anaerobios tales como lechos empacados y fluidizados, pueden utilizarse para estimar la eficacia y evaluar el funcionamiento de un Reactor de Biopelícula Anaerobia tipo Intercambiador de Calor (RBAIC . En este trabajo se ha verificado que los resultados del modelo concuerdan con los resultados experimentales de la eficacia y funcionamiento del RBAIC, dentro del periodo de puesta en marcha.

La acción extraordinaria de protección

OpenAIRE

Estrella C., Carmen

2010-01-01

La presente tesis tiene como propósito contribuir al conocimiento de la nueva garantía de derechos, puesta a disposición de los habitantes del Ecuador por la Constitución de la República, como mecanismo de jurisdicción constitucional para la protección de sus derechos, cuando resulten vulnerados por acción u omisión de los jueces en las decisiones que les corresponde adoptar, en las causas puestas a su conocimiento. Hacia este objetivo, el trabajo contiene una primera ubicación...

Incidencia del tipo de gasolinas, aditivos y equipos optimizadores de combustible comercializados en la ciudad de Cuenca, sobre las emisiones contaminantes emitidas al aire

OpenAIRE

Encalada Cajisaca, Franklin Rafael; Ñauta Uzhca, Pablo Gustavo

2010-01-01

El cantón Cuenca ubicado en la provincia del Azuay al sur de Ecuador, a una cota media de 2.550 msnm, es la tercera ciudad más grande del país y al igual que otras ciudades del Ecuador y del Mundo, registra altos índices de contaminación de su medio ambiente a causa de la emisión de gases nocivos al aire, por su creciente parque automotor, las industrias y otros sectores de actividad que utilizan combustibles fósiles como los derivados del petróleo, es decir gasolina, diesel y bunker en sus a...

Desórdenes lipídicos: una puesta al día Lipid disorders: an updating

Directory of Open Access Journals (Sweden)

Mayra Sánchez León

2003-04-01

Full Text Available Las dislipidemias son desórdenes metabólicos frecuentes, que se constituyen en un importante factor de riesgo de enfermedades, las cuales tienen como sustrato anatómico la aterosclerosis. El efecto particularmente nocivo de los niveles elevados de lípidos en el plasma está bien documentado en relación con la aparición y progresión de la enfermedad coronaria (prevención primaria y secundaria. Su manejo adecuado presupone el conocimiento de los niveles de colesterol de lipoproteína de baja densidad (C-LDL deseados, de acuerdo con la estratificación del riesgo cardiovascular del paciente. Se recomienda siempre en su tratamiento, independientemente de la categoría de riesgo, los cambios terapéuticos en el estilo de vida, y se reserva el tratamiento farmacológico para aquellos pacientes que con lo anterior no lograron las metas propuestas y para los de alto riesgo. Con la presente revisión pretendemos poner al día los principales aspectos relacionados con su clasificación, diagnóstico y tratamiento.Dyslipidemias are frequent metabolic disorders that are an important risk factor for diseases and have atherosclerosis as anatomical substrate. The particularly negative effect of high plasma lipid levels is well documented as to the occurrence and progression of the coronary disease (primary and secondary prevention. The adequate management entails knowledge of the desirable low-density lipoprotein cholesterol levels according to the cardiovascular risk stratification of the patient. Regardless of the risk category, the treatment recommends therapeutic changes in the lifestyle whereas drug treatment is reserved for those patients who did not succeed in attaining the proposed goals and for high-risk patients. The present review intends to update the fundamental aspects related to classification, diagnosis and treatment of dyslipidemias.

Cementerio: lugar de memoria y museo al aire libre. Educación patrimonial en el ámbito escolar

OpenAIRE

Jenny González Muñoz

2017-01-01

El presente artículo pertenece a una propuesta en desarrollo, expresado con el objetivo de mostrar la importancia de incluir en la escuela el estudio del cementerio como lugar de memoria y museo al aire libre que permita comprender perspectivas del arte y simbolismo como sentido de pertenencia social hacia su salvaguarda, conservación y preservación. La metodología cualtitativo-interpretativa con observación directa, apoyo fotográfico y documental aborda el rol protagónico del cementerio como...

A Johnny, compañero indispensable

OpenAIRE

Ocampo, Ángel

2013-01-01

Se trata de presentar al ser, al humano, al hombre-profesor universitario caracterizado por la puesta en práctica de sus valores: actuar con sencillez, humildad, preocuparse por el otro, el humilde avasallado; ser honestoy actuar con dignidad y tesón según lo dicten la conciencia y los valores que se abrigan, a pesar de toda circunstancia, denunciando la injusticia

Interracial Structure and Formation Mechanism of Ultrasonic-assisted Brazed Joint of SiC Ceramics with Al-12Si Filler Metals in Air

Institute of Scientific and Technical Information of China (English)

Xiaoguang Chen; Ruishan Xie; Zhiwei Lai; Lei Liu; Jiuchun Yan; Guisheng Zou

2017-01-01

Ultrasonic-assisted brazing of SiC ceramics was performed by filling with an Al--12Si alloy at a low temperature of 620 ℃ in air.The interfacial characteristics and formation mechanism were investigated.The joint shear strength reached 84-94 MPa using the ultrasonic time of 2-16 s.The fracture morphology showed that the fracture path initiated and propagated in the joint alloy.The thin film of amorphous SiO2 that formed on the SiC surface was non-uniformly decomposed and diffused into the liquid Al-12Si alloy under the cavitation erosion effect of ultrasound.Abnormal isolated blocks of Al2SiO5 compounds formed at the interface between Al--12Si and a thicker SiO2 layer formed during the thermal oxidation treatment of the SiC ceramic.The SiO2 layer on the SiC ceramic did not hinder or impair the wetting and bonding process,and a stronger bond could form between Al-12Si and SiO2 or SiC in ultrasonicassisted brazing.

High temperature properties of the Cr-Nb-Al-N coatings with increasing Al contents

OpenAIRE

Li, W. Z.; Polcar, T.; Evaristo, M.; Cavaleiro, A.

2013-01-01

Cr-Nb-Al-N coatings with Al content from 0 to 12 at.% were deposited by d.c. reactive magnetron sputtering. The coatings were annealed in protective atmosphere at 800 and 900 °C for 1 h and exposed to air at 800, 900 and 1200 °C for different times. The chemical composition, structure, microstructure, hardness and adhesive/cohesive strength of the coatings, in as-deposited and annealed conditions, were investigated and the oxidation resistance was evaluated. As expected, the Al content increa...

Ruedas cuadradas: Introducción al análisis de la falsa creatividad

Directory of Open Access Journals (Sweden)

Juan Martínez-Val

2012-04-01

Full Text Available El objetivo del artículo es analizar la denominada “falsa creatividad”. La creatividad es un valor social firmemente asentado. La falsa creatividad es aquella que se da en el proceso de creación, desarrollo o puesta a punto de un producto o servicio, destinado a un fin social. Es decir, una actividad que no tiene por qué estar ligada a las llamadas profesiones creativas ni a los conocidos como productos de diseño. El autor establece siete criterios diferenciales para analizar la “Falsa Creatividad”. Realiza una descripción exhaustiva de cada uno de ellos, identificando con ejemplos diversos los mismos. La falsa creatividad puede llevar al usuario o consumidor de un producto a rechazar este, o en todo caso, a obtener una imagen del mismo muy diferente a la que el creativo pensó, por lo que es indispensable garantizar que la creatividad en sí misma, no es un impedimento para el consumo de un producto concreto.

Fakinle et al (11)

African Journals Online (AJOL)

DELL

management issues; there is however a concern about air emissions from the ... poses risks to humans and animals through ... Nigeria have focused on cement industries. (Adejumo et al. ... based MCA which controls the sample holder and.

Controladuría como Instrumento de Gobernanza en el Sector Público

Directory of Open Access Journals (Sweden)

Márcia Martins Mendes De Luca

2013-03-01

Full Text Available La Controladuría es considerada un instrumento de Gobernanza Corporativa, en la medida en que puede contribuir para la reducción de la asimetría informacional y de conflictos de intereses, derivados de los problemas de agencia entre propietarios y gestores de las organizaciones, por medio de la puesta a disposición de informaciones que posibiliten la evaluación de la entidad y la verificación del alcance de sus objetivos. La transparencia y la accountability son pilares básicos tanto de la Gobernanza Corporativa como de la Controladuría. El Comité del Sector Público (PSC de la Federación Internacional de Contadores (IFAC desarrolló un estudio sobre gobernanza para el contexto público, teniendo en cuenta que los principios de gobernanza deberían estar presentes en las entidades públicas reflejados en cuatro dimensiones, dos de las cuales se refieren al control y a la puesta a disposición de informes externos Federación Internacional de los Contadores [IFAC] (2001. La presente pesquisa tiene como principal objetivo identificar qué informaciones puestas a disposición por la Controladuría General de la Unión (CGU, en su portal electrónico, atienden al tipo y al contenido de las recomendaciones de la IFAC referentes al control y a los informes externos, en tanto dimensiones de gobernanza en el sector público. Por medio de pesquisa bibliográfica y documental, fue constatado que solamente las informaciones referentes a los informes presupuestarios y financieros atienden al tipo y al contenido recomendado por la IFAC. La pesquisa reveló asimismo que informaciones relacionadas a la auditoría interna y a la prestación de cuentas anual del Gobierno contemplan parcialmente el contenido recomendado por la IFAC.

Controladuría como Instrumento de Gobernanza en el Sector Público

Directory of Open Access Journals (Sweden)

Mônica Clark Nunes Cavalcante

2013-01-01

Full Text Available La Controladuría es considerada un instrumento de Gobernanza Corporativa, en la medida en que puede contribuir para la reducción de la asimetría informacional y de conflictos de intereses, derivados de los problemas de agencia entre propietarios y gestores de las organizaciones, por medio de la puesta a disposición de informaciones que posibiliten la evaluación de la entidad y la verificación del alcance de sus objetivos. La transparencia y la accountability son pilares básicos tanto de la Gobernanza Corporativa como de la Controladuría. El Comité del Sector Público (PSC de la Federación Internacional de Contadores (IFAC desarrolló un estudio sobre gobernanza para el contexto público, teniendo en cuenta que los principios de gobernanza deberían estar presentes en las entidades públicas reflejados en cuatro dimensiones, dos de las cuales se refieren al control y a la puesta a disposición de informes externos Federación Internacional de los Contadores [IFAC] (2001. La presente pesquisa tiene como principal objetivo identificar qué informaciones puestas a disposición por la Controladuría General de la Unión (CGU, en su portal electrónico, atienden al tipo y al contenido de las recomendaciones de la IFAC referentes al control y a los informes externos, en tanto dimensiones de gobernanza en el sector público. Por medio de pesquisa bibliográfica y documental, fue constatado que solamente las informaciones referentes a los informes presupuestarios y financieros atienden al tipo y al contenido recomendado por la IFAC. La pesquisa reveló asimismo que informaciones relacionadas a la auditoría interna y a la prestación de cuentas anual del Gobierno contemplan parcialmente el contenido recomendado por la IFAC.

Civil Air Patrol (CAP) Aircraft Requirement Study

National Research Council Canada - National Science Library

Mercher, Christopher

1999-01-01

The Air Force Audit Agency (AFAA) concluded in its Report of Audit EB0980013 (13 May 98), Air Force Oversight of CY 1996 Civil Air Patrol Corporation Activities, CAP-USAF, Maxwell AFB, AL 36112-6323...

La transferencia de políticas globales de género y su puesta en agenda

Directory of Open Access Journals (Sweden)

Paula Ruíz

2015-06-01

Full Text Available Desde la década de los ochenta, el género se incorpora como categoría analítica e  interpretativa que ha venido evolucionado tanto en su desarrollo teórico y metodológico como político y social. En el ámbito académico, por ejemplo, su análisis se ha abordado como una construcción cultural y social, lo cual ha permitido ampliar su espacio de discusión y de estudio como método de investigación dentro de las ciencias sociales. El feminismo, como movimiento social, ha impactado en la construcción de políticas en pro del empoderamiento de la mujer, impulsando a los Estados a suscribir acuerdos que paulatinamente, en la mayoría de sociedades, han mejorado su situación en los distintos ámbitos. La movilización internacional sobre temas blandos de la agenda internacional ha llevado a la transferencia de políticas de un sistema a otro y a su puesta en agenda a nivel local. En este artículo se estudiarán los aportes que el feminismo ha desarrollado en materia de investigación dentro de las relaciones internacionales, así como la influencia que el género ha tenido para la formulación de políticas globales y la implementación de estas a nivel local.

Improvement of performance in low temperature solid oxide fuel cells operated on ethanol and air mixtures using Cu-ZnO-Al2O3 catalyst layer

Science.gov (United States)

Morales, M.; Espiell, F.; Segarra, M.

2015-10-01

Anode-supported single-chamber solid oxide fuel cells with and without Cu-ZnO-Al2O3 catalyst layers deposited on the anode support have been operated on ethanol and air mixtures. The cells consist of gadolinia-doped ceria electrolyte, Ni-doped ceria anode, and La0.6Sr0.4CoO3-δ-doped ceria cathode. Catalyst layers with different Cu-ZnO-Al2O3 ratios are deposited and sintered at several temperatures. Since the performance of single-chamber fuel cells strongly depends on catalytic properties of electrodes for partial oxidation of ethanol, the cells are electrochemically characterized as a function of the temperature, ethanol-air molar ratio and gas flow rate. In addition, catalytic activities of supported anode, catalytic layer-supported anode and cathode for partial oxidation of ethanol are analysed. Afterwards, the effect of composition and sintering temperature of catalyst layer on the cell performance are determined. The results indicate that the cell performance can be significantly enhanced using catalyst layers of 30:35:35 and 40:30:30 wt.% Cu-ZnO-Al2O3 sintered at 1100 °C, achieving power densities above 50 mW cm-2 under 0.45 ethanol-air ratio at temperatures as low as 450 °C. After testing for 15 h, all cells present a gradual loss of power density, without carbon deposition, which is mainly attributed to the partial re-oxidation of Ni at the anode.

Stratospheric Air Sub-sampler (SAS) and its application to analysis of Delta O-17(CO2) from small air samples collected with an AirCore

NARCIS (Netherlands)

Mrozek, Dorota Janina; van der Veen, Carina; Hofmann, Magdalena E. G.; Chen, Huilin; Kivi, Rigel; Heikkinen, Pauli; Rockmann, Thomas

2016-01-01

We present the set-up and a scientific application of the Stratospheric Air Sub-sampler (SAS), a device to collect and to store the vertical profile of air collected with an AirCore (Karion et al., 2010) in numerous sub-samples for later analysis in the laboratory. The SAS described here is a 20m

Género, Desarrollo y Cooperación al Desarrollo

Directory of Open Access Journals (Sweden)

Teresa Rendón

2003-02-01

Full Text Available La diferenciación social existente entre hombres y mujeres -denominada "género"en la literatura de nuestros días- es considerada como una de las modalidades de desigualdad más generalizadas en el mundo contemporáneo. Por lo tanto, lograr la igualdad social entre los sexos constituye uno de los objetivos del desarrollo y de la cooperación al desarrollo. En un principio, a la luz de un enfoque denominado "Mujeres en el desarrollo", se buscaba una mayor y mejor integración femenina a la actividad económica para el mercado, mediante programas productivos y de capacitación dirigidos a grupos de mujeres. Más tarde, este enfoque centrado en las mujeres, se sustituyó por el de "Género en el Desarrollo", un enfoque más amplio e integrado que abarca los distintos ámbitos del desarrollo y de la cooperación, pues se reconoce que el problema de la inequidad entre los sexos no atañe sólo a las mujeres sino a la sociedad en su conjunto. No obstante, entre los planes y programas y su puesta en práctica hay todavía una enorme brecha.

Diseño, construcción y puesta a punto de una instalación para la determinación de la cavitación en bombas centrífugas

OpenAIRE

Barcina García, Pedro

2016-01-01

El presente proyecto se basa en el diseño, construcción y puesta a punto de una instalación para el estudio de la cavitación en bombas centrífugas. Es una profundización, desde el punto de vista experimental, en los conocimientos aprendidos sobre el tema en las asignaturas de Ingeniería Fluidomecánica, Mecánica de Fluidos y Máquinas Hidráulicas. Además del experimento, se ha preparado la instalación y se ha redactado un guion de prácticas para que pueda ser usada con fines didácticos por los ...

Puesta al día en el manejo de las dislipidemias

Directory of Open Access Journals (Sweden)

Kunstmann F. Sonia, DRA

2012-11-01

Full Text Available Las dislipidemias juegan un rol muy importante en la patogénesis de la enfermedad ateromatosa. El manejo debe basarse en el riesgo individual, con metas de colesterol LDL según las guías internacionalmente aceptadas, que corresponde a colesterol LDL menos de100mg/dl en pacientes con enfermedad ateroesclerótica conocida o de alto riesgo. Los fibratos son drogas de elección en el manejo de las hipertrigliceridemias. Las estatinas han demostrado ser muy eficientes en reducir colesterol total, colesterol LDL y también, aunque en menor grado, en reducir triglicéridos y aumentar colesterol HDL. Están indicadas como primera línea en pacientes de alto riesgo, con enfermedad ateromatosa, o en prevención secundaria. Se discuten otros fármacos en el manejo de las dislipidemias.

Air Leakage Rates in Typical Air Barrier Assemblies

Energy Technology Data Exchange (ETDEWEB)

Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Phillip W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-11-01

Estimates for 2010 indicate that infiltration in residential buildings was responsible for 2.85 quads of energy (DOE 2014), which is about 3% of the total energy consumed in the US. One of the mechanisms being implemented to reduce this energy penalty is the use of air barriers as part of the building envelope. These technologies decrease airflow through major leakage sites such as oriented strand board (OSB) joints, and gaps around penetrations (e.g., windows, doors, pipes, electrical outlets) as indicated by Hun et al. (2014). However, most air barrier materials do not properly address leakage spots such as wall-to-roof joints and wall-to-foundation joints because these are difficult to seal, and because air barrier manufacturers usually do not provide adequate instructions for these locations. The present study focuses on characterizing typical air leakage sites in wall assemblies with air barrier materials.

Comparative analysis of aluminum-air battery propulsion systems for passenger vehicles

Science.gov (United States)

Salisbury, J. D.; Behrin, E.; Kong, M. K.; Whisler, D. J.

1980-02-01

Three electric propulsion systems using an aluminum air battery were analyzed and compared to the internal combustion engine (ICE) vehicle. The engine and fuel systems of a representative five passenger highway vehicle were replaced conceptually by each of the three electric propulsion systems. The electrical vehicles were constrained by the computer simulation to be equivalent to the ICE vehicle in range and acceleration performance. The vehicle masses and aluminum consumption rates were then calculated for the electric vehicles and these data were used as figures of merit. The Al-air vehicles analyzed were (1) an Al-air battery only electric vehicle; (2) an Al-air battery combined with a nickel zinc secondary battery for power leveling and regenerative braking; and (3) an Al-air battery combined with a flywheel for power leveling and regenerative braking. All three electric systems compared favorably with the ICE vehicle.

High-temperature resistant MeCrAlY+Al coatings obtained by ARC-PVD method on Ni Base superalloys

International Nuclear Information System (INIS)

Swadzba, L.; Maciejny, A.; Mendala, B.; Supernak, W.

1999-01-01

Investigations of obtaining high temperature coatings on the Ni base superalloys by the ARC-PVD method, using exothermic reaction processes between Ni and Al with NiAl intermetallic formation are presented in the article. By the diffusion heating at 1050 o C NiAl high temperature diffusion coating containing 21% at. Al and 50 μm thick was obtained. In the next stage coatings with more complex chemical composition NiCoCrAlY were formed. The two targets were applied for formation of complex NiCoCrAlY coatings. The good consistence between the chemical composition of the targets and the coatings and an uniform distribution of elements in the coatings were shown. Then the surface was covered with aluminium also by the ARC-PVD method. In the vacuum chamber of the equipment a synthesis reaction between NiCoCrAlY and Al with the formation NiAl intermetallics of high Co, Cr, Y content was initiated by the changes in process parameters. The final heat treatment of coatings was conducted in the air and vacuum at 1050 o C. The strong segregation of yttrium in to the oxide scale in the specimens heated in the air was shown. It was possible to obtain NiAl intermetallic phase coatings modified by Co, Cr and Y by the ARC-PVD method. An example of the application of this method for the aircraft engine turbine blades was presented. Method of ARC-PVD gives the possibility chemical composition and high resistance to oxidizing and hot corrosion. (author)

La fotografía de moda y la puesta en escena a través de la obra de Deborah Turbeville

Directory of Open Access Journals (Sweden)

Beatriz Guerrero González-Valerio

2015-01-01

Full Text Available La relación entre moda y fotografía ha sido desde siempre muy estrecha y fructífera. Dado que la moda es un producto comercial, debe ser presentada al público, tiene que comunicarse y venderse. En este sentido, las fotogra-fías de moda son muy efectivas porque establecen una comunicación inmediata con el espectador. Sin embargo, el fotógrafo de moda no sólo crea imágenes bellas para vender. A través de sus relatos, el fotógrafo sugiere y hace soñar, propone para hacer sentir y para transmitir una sensación. A la hora de crear un determinado ambiente, la fotografía de moda entra en relación y bebe de otras artes, como la pintura, la arquitectura, el teatro o el cine. Éste es el caso de la fotógrafa que nos ocupa, Deborah Turbeville. Partiendo de este contexto, el presente artículo estudiará y analizará la fotografía de moda realizada por Deborah Turbeville, recientemente fallecida a los ochenta y un años de edad. A lo largo de su dilatada carrera, la mencionada fotógrafa fue capaz de crear su propia visión, a través de unas puestas en escena llenas de poesía y misterio. El principal objetivo será tratar de establecer la concepción personal de la fotografía de moda en Deborah Turbeville y detectar, así mismo, cuáles son los elementos que subyacen en sus imágenes, además de la idea de elegancia y de belleza imperecedera. Se tratarán de establecer las analogías entre las imágenes de Deborah Turbeville y la fotografía pictorialista. La metodología se basa en la localización y recopilación de fuentes documentales. Dentro de las fuentes primarias, se estudian las obras publicadas hasta la fecha con las imágenes de Deborah Turbeville, especialmente la última publicación, Deborah Turbeville: The Fashion Pictures, Rizzoli, 2011. 

LA ESCASA APLICACIÓN DE LA TEORÍA DE RESPUESTA AL ÍTEM EN TESTS DE EJECUCIÓN TÍPICA

Directory of Open Access Journals (Sweden)

Facundo Juan Pablo Abal

2010-01-01

Full Text Available El objetivo de este trabajo fue exponer los factores que explicanla escasa aplicación de la Teoría de Respuesta al Ítem(TRI en tests de ejecución típica. Una revisión exploratoriade la literatura psicométrica permitió identificar dos factores:el histórico, que remite a problemas en la difusión de la TRIpor fuera del campo educativo y a las demandas sociales queprivilegiaron su aplicación en el contexto educativo; y el factorasociado a la aplicación, que describe los obstáculos que enla actualidad dificultan la puesta en práctica de los modelosen tests de ejecución típica. Aunque ambos factores fueronrelativamente superados, el impacto de estos en la produccióncientífica del área es aún significativo.

La integración al empleo de los condenados a una pena privativa de libertad

OpenAIRE

Ortega Bravo, María

2016-01-01

En este trabajo se pretende analizar la situación laboral que mantiene el preso durante su estancia en prisión y contemplar las distintas opciones de reinserción en la sociedad tras su puesta en libertad Grado en Relaciones Laborales y Recursos Humanos

In situ formation of CA6 platelets in Al2O3 and Al2O3/ZrO2 matrices

OpenAIRE

Belmonte , M.; SÁnchez-Herencia , A.; Moreno , R.; Miranzo , P.; Moya , J.; Tomsia , A.

1993-01-01

Al2O3 and Al2O3/ZrO2 compacts containing CaO as a dopant have been sintered under different conditions and atmospheres: air, high vacuum (> 10-6torr). SEM observations have been made on the polished surfaces of sintered and also of annealed samples. Only after the annealing treatment in air at temperatures ranging from 1400° to 1 500°C, a massive formation of CA6 platelets was detected in samples sintered in low oxygen partial pressure atmospheres.ln order to clarify the mechanism of formatio...

Nuevas formas de llevar una ópera al teatro. Un caso de estudio. La flauta mágica de la compañía 1927 y de Kosky: animación 2d, nuevas tecnologías digitales y estilo vintage

OpenAIRE

Sansone, Vincenzo

2017-01-01

La ópera, un género que a menudo se asocia al pasado, está más viva que nunca. Gracias a la aportación de directores y experimentadores provenientes del teatro, la ópera se ha convertido en uno de los campos por excelencia para la experimentación contemporánea, sobre todo en relación con el uso de nuevas tecnologías. Una verdadera paradoja. Un ejemplo es la puesta en escena de La flauta mágica de Mozart de la Komische Oper de Berlín, concebida y realizada por la compañía británica 1927 y por ...

HILOS DE TEATRO: LA PUESTA EN ESCENA DEL PALACIO DE LOS SOVIETS DE LE CORBUSIER, 1931 / Strands of theatre: Le Corbusier’s staging of the Palace of the Soviets, 1931

Directory of Open Access Journals (Sweden)

Josefina González Cubero

2012-11-01

Full Text Available RESUMEN El proyecto para el concurso del Palacio de los Soviets en Moscú (1931 de Le Corbusier plantea otra posible y más fragmentaria clave de interpretación que, aunque en principio sea más marginal, merece ser mencionada: la relación con el teatro, con la renovación de la escena europea y con la experimentación soviética, porque Le Corbusier es consciente de que la arquitectura no consiste sólo en la cualidad del edificio, es también una puesta en escena, una dramaturgia. Escenógrafos como Appia, con la luz, o directores de escena como Max Reinhardt, con el espectáculo de masas, y Vsevelod Meyerhold, con el teatro japonés del Kabuki, van penetrando en el sentir de un Le Corbusier que deja la impronta teatral en la puesta en escena de la megaestructura moscovita. SUMMARY Le Corbusier’s design submitted to the public competition for the Palace of the Soviets in Moscow (1931 may have an additional interpretation which, although less researched and in principal more marginal, is noteworthy. And that is the relationship between theatre and the resetting of the stage in Europe and Soviet experimentation. Le Corbusier was aware that architecture goes beyond the building itself and is also a sort of staging or dramaturgy. Set designers such as Appia, through the use of light, or stage directors like Max Reinhardt, through the use of performance for the masses, and Vsevelod Meyerhold, through Japonese Kabuki theatre, gradually permeated the sensibility of Le Corbusier who left staging as a mark in his design for the Moscow megastructure.

Shaping Air Mobility Forces for Future Relevance

Science.gov (United States)

2017-01-01

King Air University Press 600 Chennault Circle, Building 1405 Maxwell AFB, AL 36112-6010 afri.aupress@us.af.mil http://aupress.au.af.mil...the congressional study’s Persian Gulf scenario.37 Later Defense Department air mobility plans continued the CMMS pat- tern of paring down air mobility

EVALUACIÓN DEL PROGRAMA DE EDUCACIÓN AMBIENTAL FORMAL "AULA AL AIRE LIBRE", RESERVA LOS COYOTES

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María Gabriela Hernández Chaves

2013-01-01

Full Text Available El presente artículo muestra la evaluación realizada al programa “Aula al Aire Libre” de la Reserva Los Coyotes (Mata de Plátano, Goicoechea, en San José, Costa Rica, con el fin de presentarlo como una metodología innovadora y efectiva para la educación formal. Durante el 2010, se e valuó el nivel de conocimiento de los estudiantes participantes (n= 1085 antes y después del trabajo de campo utilizando pruebas cortas . El análisis de los resultados indicó que el momento de la prueba (antes/después tiene un efecto significativo en la nota obtenida; es decir, como consecuencia de su trabajo en Los Coyotes la cantidad de respuestas correctas aumentó de manera significativa. Para comparar la eficiencia de esta metodología con la del sistema tradicional de enseñanza, las evaluaciones post-visita fueron también administradas a un grupo control (n=498. Los resultados revelaron que los estudiantes participantes tienen un mejor manejo de los temas en cuestión que los estudiantes del grupo control. Además se aplicaron encuestas a los estudiantes y docentes de las escuelas participantes; tanto docentes como estudiantes mostraron altos niveles de satisfacción y consideraron el programa como una herramienta eficiente en la enseñanza de los contenidos formales. La encuesta además permitió identificar las fortalezas y debilidades del programa, dando así al personal de Los Coyotes información importante para reformular y mejorar la práctica.

Experimental determination of the temperature range of AlO molecular emission in laser-induced aluminum plasma in air

Energy Technology Data Exchange (ETDEWEB)

Bai, Xueshi; Motto-Ros, Vincent [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); Lei, Wenqi [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Zheng, Lijuan [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Yu, Jin, E-mail: jin.yu@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China)

2014-09-01

Measurements with laser-induced breakdown spectroscopy (LIBS) usually take place in the atmospheric air. For quantitative analysis of metallic elements, oxidation may represent an important issue which can significantly modify the stoichiometry of the plasma. Molecule formation in plasma should be therefore studied and taken into account in the LIBS practice. In this work, we experimentally investigated the temporal evolution and transformation of the plasma induced on an aluminum target by a nanosecond infrared (1064 nm) laser in the atmospheric air, in terms of its temperatures over a large interval of time from hundreds of nanoseconds to tens of microseconds. Such evolution was then correlated to the temporal evolution of the emission intensity from AlO molecules in the ablation plume. In particular, for a given ablation laser pulse energy, the appearance of the molecular emission while the plume cools down allows determining a minimal delay, τ{sub min}, which corresponds to a maximal value of the temperature, T{sub max}, below which the molecular emission begins to be clearly observed and to grow as a function of the delay. Such delay or such temperature indicates the longest delay or the lowest temperature for laser-induced plasma to be suitable for a correct analysis of metallic elements without significant influence of the alternation of the stoichiometry by oxidation. In our experiment, the values of τ{sub min} and T{sub max} have been determined for a range of ablation laser pulse energies from 5 mJ to 50 mJ. These values lie respectively in the range of 3 to 15 μs for τ{sub min}, and 4500 K to 6600 K in terms of the molecule temperature for T{sub max}. Beyond the practical interest for LIBS, our results provide also insights to the kinetics of the AlO molecule formation in laser-induced plasma. - Highlights: • Determination of the temperatures in laser-induced plasma up to tens of microseconds • Determination of the molecule temperature by fitting

Tribological Properties of Ti(Al,O)/Al2O3 Composite Coating by Thermal Spraying

Science.gov (United States)

Salman, Asma; Gabbitas, Brian; Cao, Peng; Zhang, Deliang

The use of thermal spray coatings provides protection to the surfaces operating in severe environments. The main goal of the current work is to investigate the possibility of using a high velocity air fuel (HVAF) thermally sprayed wear resistant Ti(Al,O)/Al2O3 coating on tool steel (H13) which is used for making dies for aluminium high pressure die casting and dummy blocks aluminium extrusion. A feedstock of Ti(Al,O)/Al2O3 composite powder was produced from a mixture of Al and TiO2 powders by high energy mechanical milling, followed by a thermal reaction process. The feedstock was then thermally sprayed using a high velocity air-fuel (HVAF) technique onto H13 steel substrates to produce a composite coating. The present study describes and compares the tribological properties such as friction and sliding wear rate of the coating both at room and high temperature (700°C). The wear resistance of the coating was investigated by a tribometer using a spherical ended alumina pin as a counter body under dry and lubricating conditions. The results showed that composite coating has lower wear rate at high temperature than at room temperature without using lubricant. The composite coating was characterized using scanning electron microscopy (SEM), optical microscopy and X-ray diffractometry (XRD). This paper reports the experimental observations and discusses the wear resistance performance of the coatings at room and high temperatures.

A comprehensive review on recent progress in aluminum–air batteries

Directory of Open Access Journals (Sweden)

Yisi Liu

2017-07-01

Full Text Available The aluminum–air battery is considered to be an attractive candidate as a power source for electric vehicles (EVs because of its high theoretical energy density (8100 Wh kg−1, which is significantly greater than that of the state-of-the-art lithium-ion batteries (LIBs. However, some technical and scientific problems preventing the large-scale development of Al–air batteries have not yet to be resolved. In this review, we present the fundamentals, challenges and the recent advances in Al–air battery technology from aluminum anode, air cathode and electrocatalysts to electrolytes and inhibitors. Firstly, the alloying of aluminum with transition metal elements is reviewed and shown to reduce the self-corrosion of Al and improve battery performance. Additionally for the cathode, extensive studies of electrocatalytic materials for oxygen reduction/evolution including Pt and Pt alloys, nonprecious metal catalysts, and carbonaceous materials at the air cathode are highlighted. Moreover, for the electrolyte, the application of aqueous and nonaqueous electrolytes in Al–air batteries are discussed. Meanwhile, the addition of inhibitors to the electrolyte to enhance electrochemical performance is also explored. Finally, the challenges and future research directions are proposed for the further development of Al–air batteries. Keywords: Aluminum–air battery, Aluminum anode, Air cathode, Oxygen reduction reaction, Electrolytes

Repercusiones de la anorexia y la bulimia en la salud oral, prevención y tratamiento

OpenAIRE

Gomez Jiménez, Antonio; Casals Peidró, Elías; Boj Quesada, Juan Ramón

2000-01-01

El presente artículo trata de aportar una puesta al día de los problemas que presentan los pacientes afectados de anorexia y de bulimia nerviosa. Se expone la información que el odontólogo debe tener en cuenta respecto al conocimiento de la enfermedad, sus manifestaciones orales, los criterios diagnósticos y los enfoques preventivos y terapéuticos necesarios.

Regional Precipitation Forecast with Atmospheric InfraRed Sounder (AIRS) Profile Assimilation

Science.gov (United States)

Chou, S.-H.; Zavodsky, B. T.; Jedloved, G. J.

2010-01-01

Advanced technology in hyperspectral sensors such as the Atmospheric InfraRed Sounder (AIRS; Aumann et al. 2003) on NASA's polar orbiting Aqua satellite retrieve higher vertical resolution thermodynamic profiles than their predecessors due to increased spectral resolution. Although these capabilities do not replace the robust vertical resolution provided by radiosondes, they can serve as a complement to radiosondes in both space and time. These retrieved soundings can have a significant impact on weather forecasts if properly assimilated into prediction models. Several recent studies have evaluated the performance of specific operational weather forecast models when AIRS data are included in the assimilation process. LeMarshall et al. (2006) concluded that AIRS radiances significantly improved 500 hPa anomaly correlations in medium-range forecasts of the Global Forecast System (GFS) model. McCarty et al. (2009) demonstrated similar forecast improvement in 0-48 hour forecasts in an offline version of the operational North American Mesoscale (NAM) model when AIRS radiances were assimilated at the regional scale. Reale et al. (2008) showed improvements to Northern Hemisphere 500 hPa height anomaly correlations in NASA's Goddard Earth Observing System Model, Version 5 (GEOS-5) global system with the inclusion of partly cloudy AIRS temperature profiles. Singh et al. (2008) assimilated AIRS temperature and moisture profiles into a regional modeling system for a study of a heavy rainfall event during the summer monsoon season in Mumbai, India. This paper describes an approach to assimilate AIRS temperature and moisture profiles into a regional configuration of the Advanced Research Weather Research and Forecasting (WRF-ARW) model using its three-dimensional variational (3DVAR) assimilation system (WRF-Var; Barker et al. 2004). Section 2 describes the AIRS instrument and how the quality indicators are used to intelligently select the highest-quality data for assimilation

Quantitative assessments of indoor air pollution and the risk of childhood acute leukemia in Shanghai

International Nuclear Information System (INIS)

Gao, Yu; Zhang, Yan; Kamijima, Michihiro; Sakai, Kiyoshi; Khalequzzaman, Md; Nakajima, Tamie; Shi, Rong; Wang, Xiaojin; Chen, Didi; Ji, Xiaofan; Han, Kaiyi; Tian, Ying

2014-01-01

We investigated the association between indoor air pollutants and childhood acute leukemia (AL). A total of 105 newly diagnosed cases and 105 1:1 gender-, age-, and hospital-matched controls were included. Measurements of indoor pollutants (including nitrogen dioxide (NO 2 ) and 17 types of volatile organic compounds (VOCs)) were taken with diffusive samplers for 64 pairs of cases and controls. Higher concentrations of NO 2 and almost half of VOCs were observed in the cases than in the controls and were associated with the increased risk of childhood AL. The use of synthetic materials for wall decoration and furniture in bedroom was related to the risk of childhood AL. Renovating the house in the last 5 years, changing furniture in the last 5 years, closing the doors and windows overnight in the winter and/or summer, paternal smoking history and outdoor pollutants affected VOC concentrations. Our results support the association between childhood AL and indoor air pollution. - Highlights: • We firstly assessed the effects of indoor air pollution on childhood AL in China. • Indoor air pollutants were assessed by questionnaire and quantitative measurements. • NO 2 and 17 types of VOCs were measured in bedrooms of both cases and controls. • Higher concentrations of indoor air pollutants increased the risk of childhood AL. • Indoor behavioral factors and outdoor pollution might affect indoor air pollution. - Higher concentrations of indoor air pollutants were related to an elevated risk of childhood AL

Kinetic studies of oxidation of MgAlON and a comparison of the oxidation behaviour of AlON, MgAlON, O'SiAlON-ZrO{sub 2}, and BN-ZCM ceramics

Energy Technology Data Exchange (ETDEWEB)

Wang Xidong; Seetharaman, S. [Div. of Metallurgy, Royal Inst. of Tech., Stockholm (Sweden); Li Wenchao [Dept. of Physical Chemistry, Univ. of Science and Technology Beijing (USTB), Beijing, BJ (China)

2002-06-01

The kinetics and morphology of the oxidation process of magnesium-aluminium oxynitride (MgAlON), aluminium oxynitride (AlON), O'SiAlON-ZrO{sub 2}, and BN-ZCM have been studied in the temperature range 1373-1773 K (ZCM=30 wt% ZrO{sub 2}, 52 wt% Al{sub 2}O{sub 3} and 18 wt% 3 Al{sub 2}O{sub 3}.2 SiO{sub 2}). Oxidation experiments with powder and plate samples of the above materials have been carried out in air. MgAlON shows the best resistance to oxidation at lower temperatures (< 1473 K), whereas at higher temperatures ({proportional_to} 773 K), AlON shows the best resistance. O'SiAlON-ZrO{sub 2} shows very good oxidation resistance up to 1673 K. But its oxidation rate increases strongly above 1673 K, presumably due to the formation of liquid phase. BN-ZCM has the poorest oxidation resistance due to the evaporation of B{sub 2}O{sub 3}. The activation energies for the chemical oxidation reaction of AlON, MgAlON, and O'SiAlON-ZrO{sub 2} are 214, 330 and 260 kJ/mol, respectively. The overall diffusion activation energies for AlON, MgAlON, O'SiAlON-ZrO{sub 2} and BN-ZCM are 227, 573, 367 and 289 kJ/mol, respectively. (orig.)

Oxidation behavior of arc evaporated Al-Cr-Si-N thin films

Energy Technology Data Exchange (ETDEWEB)

Tritremmel, Christian; Daniel, Rostislav; Mitterer, Christian; Mayrhofer, Paul H.; Lechthaler, Markus; Polcik, Peter [Christian Doppler Laboratory for Advanced Hard Coatings, Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Christian Doppler Laboratory for Application Oriented Coating Development, Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); OC Oerlikon Balzers AG, Iramali 18, LI-9496 Balzers (Liechtenstein); PLANSEE Composite Materials GmbH, Siebenbuergerstrasse 23, D-86983 Lechbruck am See (Germany)

2012-11-15

The impact of Al and Si on the oxidation behavior of Al-Cr-(Si)-N thin films synthesized by arc evaporation of powder metallurgically prepared Al{sub x}Cr{sub 1-x} targets with x = Al/(Al + Cr) of 0.5, 0.6, and 0.7 and (Al{sub 0.5}Cr{sub 0.5}){sub 1-z}Si{sub z} targets with Si contents of z = 0.05, 0.1, and 0.2 in N{sub 2} atmosphere was studied in detail by means of differential scanning calorimetry, thermogravimetric analysis (TGA), x-ray diffraction, and Raman spectroscopy. Dynamical measurements in synthetic air (up to 1440 Degree-Sign C) revealed the highest onset temperature of pronounced oxidation for nitride coatings prepared from the Al{sub 0.4}Cr{sub 0.4}Si{sub 0.2} target. Isothermal TGA at 1100, 1200, 1250, and 1300 Degree-Sign C highlight the pronounced improvement of the oxidation resistance of Al{sub x}Cr{sub 1-x}N coatings by the addition of Si. The results show that Si promotes the formation of a dense coating morphology as well as a dense oxide scale when exposed to air.

Farklı Çalışma Ortamlarında Oluşabilecek Hava Kirliliğinin Çalışanların Sağlığı Üzerindeki Etkileri / The Effects of Air Pollution on Workers’ Health In Different Work Places

Directory of Open Access Journals (Sweden)

Simge Taner

2012-12-01

ıyla ilgili alınabilecek tedbirler açıklanmaya çalışılmıştır. The Effects of Air Pollution on Workers’ Health In Different Work Places Air quality in industrial and non-industrial work places (such as school, office, photocopy center, restaurant is very significant not only for workers’ comfort, but also for their health. Generally, parameters such as temperature, moisture, air exchange rate, sulphur dioxide (SO2, carbon dioxide (CO2, suspended particulate matter (PM, hydrogen sulphide (H2S, volatile organic compounds (VOC, nitrogen oxides (NOx, carbon monoxide (CO, ozone (O3, radon, hydrogen fluoride (HF, formaldehyde (HCHO and microbial control are analyzed for indoor air quality assessment. With the help of these analyses some important foresights could be made for workers’ health. Lots of pollutant can be defined in production areas, especially metal processing and iron steel industry compared to other working places. In our country, not only production sector but also mining operations have lots of health risks for human and environment. Although occupational diseases have notable risks for employees working in mines, there are not adequate analyses. In this study, parameters which have adverse effects on indoor air quality in mining and metal sectors are investigated and some measures suggested to protect for employees’ health working in these sectors.

Luminescence of delafossite-type CuAlO2 fibers with Eu substitution for Al cations.

Science.gov (United States)

Liu, Yin; Gong, Yuxuan; Mellott, Nathan P; Wang, Bu; Ye, Haitao; Wu, Yiquan

2016-01-01

CuAlO 2 has been examined as a potential luminescent material by substituting Eu for Al cations in the delafossite structure. CuAlO 2 :Eu 3+ nanofibers have been prepared via electrospinning for the ease of mitigating synthesis requirements and for future optoelectronics and emerging applications. Single-phase CuAlO 2 fibers could be obtained at a temperature of 1100 °C in air. The Eu was successfully doped in the delafossite structure and two strong emission bands at ~405 and 610 nm were observed in the photoluminescence spectra. These bands are due to the intrinsic near-band-edge transition of CuAlO 2 and the f-f transition of the Eu 3+ activator, respectively. Further electrical characterization indicated that these fibers exhibit semiconducting behavior and the introduction of Eu could act as band-edge modifiers, thus changing the thermal activation energies. In light of this study, CuAlO 2 :Eu 3+ fibers with both strong photoluminescence and p-type conductivity could be produced by tailoring the rare earth doping concentrations.

Thickness engineering of atomic layer deposited Al2O3 films to suppress interfacial reaction and diffusion of Ni/Au gate metal in AlGaN/GaN HEMTs up to 600 °C in air

Science.gov (United States)

Suria, Ateeq J.; Yalamarthy, Ananth Saran; Heuser, Thomas A.; Bruefach, Alexandra; Chapin, Caitlin A.; So, Hongyun; Senesky, Debbie G.

2017-06-01

In this paper, we describe the use of 50 nm atomic layer deposited (ALD) Al2O3 to suppress the interfacial reaction and inter-diffusion between the gate metal and semiconductor interface, to extend the operation limit up to 600 °C in air. Suppression of diffusion is verified through Auger electron spectroscopy (AES) depth profiling and X-ray diffraction (XRD) and is further supported with electrical characterization. An ALD Al2O3 thin film (10 nm and 50 nm), which functions as a dielectric layer, was inserted between the gate metal (Ni/Au) and heterostructure-based semiconductor material (AlGaN/GaN) to form a metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). This extended the 50 nm ALD Al2O3 MIS-HEMT (50-MIS) current-voltage (Ids-Vds) and gate leakage (Ig,leakage) characteristics up to 600 °C. Both, the 10 nm ALD Al2O3 MIS-HEMT (10-MIS) and HEMT, failed above 350 °C, as evidenced by a sudden increase of approximately 50 times and 5.3 × 106 times in Ig,leakage, respectively. AES on the HEMT revealed the formation of a Ni-Au alloy and Ni present in the active region. Additionally, XRD showed existence of metal gallides in the HEMT. The 50-MIS enables the operation of AlGaN/GaN based electronics in oxidizing high-temperature environments, by suppressing interfacial reaction and inter-diffusion of the gate metal with the semiconductor.

Factores predictivos de la no adherencia al tratamiento de la tuberculosis en municipios del Área Metropolitana de Buenos Aires, Argentina

Directory of Open Access Journals (Sweden)

Silvina Arrossi

2012-01-01

Full Text Available El objetivo de este estudio fue identificar las características sociodemográficas de los pacientes y las características del tratamiento que influyen en la no-adherencia al tratamiento antituberculoso. Se realizó un estudio de corte transversal, en el Área Metropolitana de Buenos Aires. Se encuestaron 38 pacientes que no adhirieron al tratamiento y 85 pacientes que adhirieron al tratamiento, diagnosticados durante el año 2007, residentes y atendidos en hospitales de municipios seleccionados. El análisis de los factores se llevó a cabo mediante regresión logística. Los resultados indican que los pacientes con viviendas sin agua, tuvieron 3 veces más probabilidad de no adherencia (OR=2,8; IC95% 1,1-6,9. Asimismo, los pacientes que realizaban los controles en un hospital tuvieron 3 veces más riesgo de no adherir que los que los realizaban en centros de atención primaria (OR=3,2; IC95% 1,1-8,9. Estos resultados permiten delinear un perfil de paciente en riesgo de no-adherencia, caracterizado por estar en condiciones de pobreza, y con dificultades de acceso a la atención de su salud.

Luminescence of Eu:Y3Al5O12, Eu:Lu3Al5O12, and Eu:GdAlO3 Nanocrystals Synthesized by Solution Combustion

Science.gov (United States)

Vilejshikova, E. V.; Khort, A. A.; Podbolotov, K. B.; Loiko, P. A.; Shimanski, V. I.; Shashkov, S. N.; Yumashev, K. V.

2017-11-01

Nanocrystals of rare-earth garnets Y3Al5O12 and Lu3Al5O12 and perovskite GdAlO3 highly doped (10-20 at%) with Eu3+ are synthesized by the solution combustion technique and subsequent annealing in air at 800 and 1300oC. Their structure, morphology, and phase composition are studied. These materials exhibit intense red luminescence under UV excitation. Eu:GdAlO3 luminescence has CIE 1931 color coordinates (0.632, 0.368); dominant wavelength, 599.6 nm; and color purity, >99%. Judd-Ofelt parameters, luminescence branching ratios, and lifetimes of the Eu3+ 5D0 state are determined. The luminescence quantum yield for Eu:GdAlO3 (10 at%) reaches 74% with a lifetime of 1.4 ms for the 5D0 state. The synthesized materials are promising for red ceramic phosphors.

Effect of iodine on the corrosion of Au-Al wire bonds

DEFF Research Database (Denmark)

Verdingovas, Vadimas; Müller, Lutz; Jellesen, Morten Stendahl

2015-01-01

Corrosion study was performed on Au-Al wire bonds, thin layers of sputter deposited Au and Al, and Au-Al intermetallic nuggets. The test environment was iodine-vapour in air (1. mg/L) at 85 °C with varying relative humidity, and 500 mg/L of KI in water. GDOES, XRD, SEM EDS, wire bond shear......, and electrochemical testing were used to characterize the samples. Failures of Au-Al wire bonds were found to be primarily attributed to the corrosion of Al via formation of Al iodides and consequent formation of Al oxides and/or hydroxides. Most susceptible to corrosion are Al metallization and Al rich intermetallic...

Geoingeniería, apuesta incierta frente al cambio climático

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Gian Carlo Delgado Ramos

2012-01-01

Full Text Available Ante el acelerado aumento de la concentración de gases de efecto invernadero, producto de un metabolismo social creciente (uso de energía y materiales, se ha propuesto, como potencial solución, la puesta en marcha de diversas tecnologías, entre ellas aquellas diseñadas para manipular y controlar el clima. El presente texto revisa el metabolismo social imperante y sus proyecciones para las próximas décadas, para desde ahí presentar la problemática y el reto del cambio climático, sus implicaciones y las soluciones tecnológicas de manipulación del clima propuestas desde un discurso político que aboga por una "economía verde". A partir de describir las geoingenierías propuestas, se revisa críticamente su complejidad, viabilidad, incertidumbres y potenciales implicaciones. Reconociendo que el uso de las geoingenierias es más un asunto económico-político que técnico, se concluye con un llamado a abrir el debate sobre las implicaciones y deseabilidad de tales o cuales geoingenierías, partiendo de la premisa de que la principal medida frente al cambio climático es la efectiva reducción del metabolismo social y por tanto de las emisiones.

Interaction of hydrogen with an Mg-Al alloy

International Nuclear Information System (INIS)

Andreasen, A.; Sorensen, M.B.; Burkarl, R.; Moller, B.; Molenbroek, A.M.; Pedersen, A.S.; Andreasen, J.W.; Nielsen, M.M.; Jensen, T.R.

2005-01-01

The interaction of hydrogen with an Mg-Al alloy pre-exposed to air have been studied with in situ time resolved X-ray powder diffraction. Phase fractions as a function of time are derived from series of consecutive diffraction patterns allowing kinetic analysis. The apparent activation energy for dehydrogenation of the Mg-Al alloy is found to be 160 kJ/mol. This is not significantly higher than for pure and fully activated Mg. It is suggested that the addition of Al improves the resistance towards oxygen contamination

Cost and energy consumption estimates for the aluminum-air battery anode fuel cycle

Science.gov (United States)

1990-01-01

At the request of DOE's Office of Energy Storage and Distribution (OESD), Pacific Northwest Laboratory (PNL) conducted a study to generate estimates of the energy use and costs associated with the aluminum anode fuel cycle of the aluminum-air (Al-air) battery. The results of this analysis indicate that the cost and energy consumption characteristics of the mechanically rechargeable Al-air battery system are not as attractive as some other electrically rechargeable electric vehicle battery systems being developed by OESD. However, there are distinct advantages to mechanically rechargeable batteries, which may make the Al-air battery (or other mechanically rechargeable batteries) attractive for other uses, such as stand-alone applications. Fuel cells, such as the proton exchange membrane (PEM), and advanced secondary batteries may be better suited to electric vehicle applications.

Le rôle du vocabulaire du théâtre dans la mise en scène du texte dramatique

Directory of Open Access Journals (Sweden)

Mariana CHIRIŢA

2016-05-01

Full Text Available La adquisición del vocabulario de una lengua extranjera asegura el éxito de la comunicación de los hablantes. El trabajo del vocabulario de especialidad, al contrario, permite a los hablantes expresarse mejor en un dominio específico. Este artículo se focaliza en el papel del léxico del teatro en la puesta en escena del teatro dramático y su enseñanza en la clases de FLE. Nuestras actividades están destinadas a los estudiantes principiantes en FLE, con el fin de facilitar la exploración del texto dramático, lo cual supone tanto el trabajo sobre el texto como producto lingüístico como sobre su puesta en escena.

Oxide Morphology of a FeCrAl Alloy, Kanthal APMT, Following Extended Aging in Air at 300 °C to 600 °C

Science.gov (United States)

Li, Nan; Parker, Stephen S.; Wood, Elizabeth S.; Nelson, Andrew T.

2018-05-01

Iron-chromium-aluminum (FeCrAl) alloys are of interest to the nuclear materials community due to their resistance to high-temperature steam oxidation under accident conditions. The present work investigates oxide formation at temperatures relevant to light water reactor cladding operation following extended aging to assess growth kinetics, chemical composition, and microstructure of oxide formation on a commercial FeCrAl alloy, Fe-21 wt pct Cr-5 wt pct Al-3 wt pct Mo (Kanthal APMT). Aging treatments were performed for 100 to 1000 hours in stagnant air at 300 °C, 400 °C, 500 °C, and 600 °C, respectively. Oxide growth behavior under the investigated conditions follows a logarithmic time dependence. When the oxidization temperature is 400 °C or below, the oxide is amorphous. At 500 °C, isolated crystalline regions start to appear during short period aging time and expand with extended exposures. Crystalline α-Al2O3 oxide film develops at 600 °C and the correlated logarithmic rate constant decreases significantly, indicating enhanced oxidation resistance of the formed oxide film. In addition, Mo segregation at grain boundaries has been observed when the aging temperature exceeds 500 °C. The results of this study can be viewed as an upper bounding result for potential oxide coarsening during reactor operation.

Asalto al poder en el porno. Apropiación y empoderamiento en las narraciones postpornográficas

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Alberto García del Castillo

2011-06-01

Full Text Available Es labor de la postpornografía hacer que sexualidades otras y formas nuevas de follar salten al panorama público y, por tanto, político; su discurso crítico revisa la historia del porno desde el post-feminismo y las luchas homosexuales para ganar un espacio de representación y consumo de la sexualidad y permitir la visibilización de lo otro, antes ausente en la pornografía. El postporno, comprendido como representación propia del movimiento queer, alberga en su centro dinámicas de empoderamiento, en estrecha relación con estrategias de apropiación; es toma de poder en si mismo, pero también representación de apropiaciones posibles y creador por tanto de realidades disidentes del discurso normativo. El epoderamiento se juega tanto en el exterior como en el interior del postporno, siendo a la vez agente y documento de apropiaciones. Indagando en el interior de la narración postpornográfica descubrimos elementos que actúan apropiaciones de poder; la propia historia del postporno habla de la puesta en juego de estrategias de empoderamiento. Identificando estos elementos como actantes, se muestra atractiva la búsqueda de un modelo que permita sondar los mecanismos de empoderamiento jugados dentro de las narraciones postpornográficas; por ello, veremos de qué manera la semiótica se acerca a la propuesta contracultural de este asalto al poder en el porno.

Characterization of Conventional and High-Translucency Y-TZP Dental Ceramics Submitted to Air Abrasion.

Science.gov (United States)

Tostes, Bhenya Ottoni; Guimarães, Renato Bastos; Noronha-Filho, Jaime Dutra; Botelho, Glauco Dos Santos; Guimarães, José Guilherme Antunes; Silva, Eduardo Moreira da

2017-01-01

This study evaluated the effect of air-abrasion on t®m phase transformation, roughness, topography and the elemental composition of three Y-TZP (Yttria-stabilized tetragonal zirconia polycrystal) dental ceramics: two conventional (Lava Frame and IPS ZirCad) and one with high-translucency (Lava Plus). Plates obtained from sintered blocks of each ceramic were divided into four groups: AS (as-sintered); 30 (air-abrasion with 30 mm Si-coated Al2O3 particles); 50 (air-abrasion with 50 mm Al2O3 particles) and 150 (air-abrasion with 150 mm Al2O3 particles). After the treatments, the plates were submitted to X-ray diffractometry; 3-D profilometry and SEM/EDS. The AS surfaces were composed of Zr and t phases. All treatments produced t®m phase transformation in the ceramics. The diameter of air-abrasion particles influenced the roughness (150>50>30>AS) and the topography. SEM analysis showed that the three treatments produced groove-shaped microretentions on the ceramic surfaces, which increased with the diameter of air-abrasion particles. EDS showed a decrease in Zr content along with the emergence of O and Al elements after air-abrasion. Presence of Si was also detected on the plates air-abraded with 30 mm Si-coated Al2O3 particles. It was concluded that irrespective of the type and diameter of the particles, air-abrasion produced t®m phase transformation, increased the roughness and changed the elemental composition of the three Y-TZP dental ceramics. Lava Plus also behaved similarly to the conventional Y-TZP ceramics, indicating that this high translucency ceramic could be more suitable to build monolithic ceramic restorations in the aesthetic restorative dentistry field.

OBSTÁCULOS AL APRENDIZAJE DEL CONCEPTO ESTRUCTURANTE EVOLUCIÓN BIOLÓGICA

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Roger Araujo Llamas

2014-05-01

Full Text Available Se contrastaron los obstáculos en el aprendizaje del concepto evolución biológica reportados en publicaciones especializadas en la enseñanza de las ciencias,  con losen la implementación de un juego para enseñar evolución por selección natural. Lo anterior, se realizó mediante la revisión de antecedentes que permitieron identificar los obstáculos encontrados por otros investigadores y la puesta en marcha de la propuesta didáctica que posibilitó identificar y superar algunos de los mismos. Existen múltiples factores que dificultan la comprensión de la evolución biológica, componentes culturales, iconografía inapropiada, insuficiente preparación de los profesores, estrategias didácticas inadecuadas y apreciación negativa de la teoría evolutiva, son algunos de ellos. Por otra parte, algunas ideas previas propias del estudiante o transmitidas por el profesor pueden funcionar como obstáculos al aprendizaje de este concepto estructurante; el esencialismo biológico, las concepciones lamarckistas, la ortogénesis, la teleología, y no concebir el concepto de “miles de millones de años”, hacen parte de las explicaciones que los estudiantes suelen utilizar. Es pertinente señalar que, los obstáculos al aprendizaje de los estudiantes no son muy diferentes a los que tuvo que superar la biología para establecer su actual paradigma. Éstos, se superan en buena medida cuando se comprenden conceptos imprescindibles en el cambio de los sistemas vivos, como: especie biológica, población, variabilidad genética, herencia, azar, mutación, desarrollo ontogénico, filogenia, ancestro común, adaptación, selección natural y tiempo geológico.

Influence of turbulent flow on the explosion parameters of micro- and nano-aluminum powder–air mixtures

International Nuclear Information System (INIS)

Liu, Xueling; Zhang, Qi

2015-01-01

Highlights: • The slope of P_m_a_x versus U_r_m_s is greater for nano-Al powder than for micro-Al powder. • The u_e_f_f_,_m_a_x of micro-Al and nano-Al powder-air mixtures increases linearly with U_r_m_s. • For micro- and nano-Al powders, u_e_f_f_, _m_a_x increases as the percentage of nano-Al increases. - Abstract: The environmental turbulence intensity has a significant influence on the explosion parameters of both micro- and nano-Al at the time of ignition. However, explosion research on turbulence intensity with respect to micro- and nano-Al powders is still insufficient. In this work, micro- and nano-aluminum powders were investigated via scanning electron microscopy (SEM), and their particle size distributions were measured using a laser diffraction analyzer under dispersing air pressures of 0.4, 0.6, and 0.8 MPa in a 20 L cylindrical, strong plexiglass vessel. The particle size distributions in three different mass ratio mixtures of micro- and nano-Al powders (micro-Al:nano-Al_[_m_a_s_s_r_a_t_i_o_] = 95:5, 90:10, and 85:15) were also measured. The results show that the agglomerate size of nano-Al powder is an order of magnitude larger than the nanoparticles’ actual size. Furthermore, the turbulence intensity ranges (U_r_m_s) of the Al powder-air mixtures were measured using particle image velocimetry (PIV) under dispersing air pressures of 0.4, 0.6, and 0.8 MPa. The effect of turbulence intensity on the explosion characteristics of the micro- and nano-Al powders was investigated using a 20 L cylindrical explosion vessel. The results of micro-Al and nano-Al powder-air mixtures with a stoichiometric concentration of 337.00 g·m"−"3 were discussed for the maximum explosion pressure, the maximum rate of pressure increase and the maximum effective burning velocity under the different turbulence intensity.

Friction and wear properties of Ti6Al4V/WC-Co in cold atmospheric plasma jet

International Nuclear Information System (INIS)

Xu Wenji; Liu Xin; Song Jinlong; Wu Libo; Sun Jing

2012-01-01

Highlights: ► Cold plasma jet can effectively reduce the friction coefficients of Ti6Al4V/WC-Co friction pairs. ► Cold plasma jet can easily form nitrides on the surface of Ti6Al4V and on new surfaces generated by tool wear. ► The nitrides can reduce the friction coefficients and protect the friction surface. - Abstract: The friction and wear properties of Ti6Al4V/WC-Co friction pair were studied using an autonomous atmospheric pressure bare electrode cold plasma jet generating device and block-on-ring friction/wear tester, respectively. The study was conducted under air, air jet, nitrogen jet, air cold plasma jet, and nitrogen cold plasma jet atmospheres. Both nitrogen cold and air cold plasma jets effectively reduced the friction coefficients of the friction pairs and decreased friction temperature. The friction coefficient in the nitrogen cold plasma jet decreased to almost 60% compared with that in the air. The scanning electron microscope, energy-dispersive X-ray spectroscope, and X-ray diffraction analyses illustrated that adhesive wear was relieved and the friction surfaces of Ti6Al4V were smoother, both in the nitrogen cold and air cold plasma jets. The roughness value R a of the Ti6Al4V friction surfaces can reach 1.107 μm. A large number of nitrogen particles in the ionic and excited states contained by cold plasma jets reacts easily on the friction surface to produce a large amount of nitrides, which can excellently reduce the wear of Ti6Al4V/WC-Co friction pairs in real-time.

Improving the aluminum-air battery system for use in electrical vehicles

Science.gov (United States)

Yang, Shaohua

The objectives of this study include improvement of the efficiency of the aluminum/air battery system and demonstration of its ability for vehicle applications. The aluminum/air battery system can generate enough energy and power for driving ranges and acceleration similar to that of gasoline powered cars. Therefore has the potential to be a power source for electrical vehicles. Aluminum/air battery vehicle life cycle analysis was conducted and compared to that of lead/acid and nickel-metal hydride vehicles. Only the aluminum/air vehicles can be projected to have a travel range comparable to that of internal combustion engine vehicles (ICE). From this analysis, an aluminum/air vehicle is a promising candidate compared to ICE vehicles in terms of travel range, purchase price, fuel cost, and life cycle cost. We have chosen two grades of Al alloys (Al alloy 1350, 99.5% and Al alloy 1199, 99.99%) in our study. Only Al 1199 was studied extensively using Na 2SnO3 as an electrolyte additive. We then varied concentration and temperature, and determined the effects on the parasitic (corrosion) current density and open circuit potential. We also determined cell performance and selectivity curves. To optimize the performance of the cell based on our experiments, the recommended operating conditions are: 3--4 N NaOH, about 55°C, and a current density of 150--300 mA/cm2. We have modeled the cell performance using the equations we developed. The model prediction of cell performance shows good agreement with experimental data. For better cell performance, our model studies suggest use of higher electrolyte flow rate, smaller cell gap, higher conductivity and lower parasitic current density. We have analyzed the secondary current density distributions in a two plane, parallel Al/air cell and a wedge-type Al/air cell. The activity of the cathode has a large effect on the local current density. With increases in the cell gap, the local current density increases, but the increase is

Una gran medida de ‘opinio juris’ y práctica estatal al gusto: ¿la receta de la costumbre internacional contemporánea?

Directory of Open Access Journals (Sweden)

Fabián Augusto Cárdenas Castañeda

2015-03-01

Full Text Available La práctica social internacional del derecho internacional contemporáneo no corresponde totalmente a la práctica que existía al momento del establecimiento de la cij. El mundo de 1945 definitivamente no es igual al del siglo xxi. Esta realidad ha transformado indudablemente el derecho internacional y cada uno de sus componentes vertebrales, incluyendo la teoría de las fuentes y sus diversos tipos. Desde tal perspectiva, la presente investigación busca revisar el concepto tradicional de la costumbre internacional mediante el estudio de sus dos ingredientes, en particular de la opinio juris, la cual será puesta a prueba a través del uso de literatura y jurisprudencia jurídicas contemporáneas. Luego de exponer algunas de las más grandes dificultades del concepto clásico de la opinio juris, se hará una presentación de novedosos y actualizados conceptos de ella. Lo anterior llevará a demostrar si de hecho se requiere un desarrollo de la definición clásica de la opinio juris y si se puede sugerir que esta es el único ingrediente requerido en la receta de la costumbre internacional contemporánea.

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

International Nuclear Information System (INIS)

Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A.; García, Juan

2013-01-01

Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min −1 and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min −1 , respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T r = 0.098 g Ni min mL −1 . After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T r = 0.098 g Ni min mL −1 , attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

Energy Technology Data Exchange (ETDEWEB)

Vallet, Ana [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Ovejero, Gabriel, E-mail: govejero@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Rodríguez, Araceli [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Peres, José A. [Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal); García, Juan, E-mail: juangcia@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

2013-01-15

Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min{sup −1} and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min{sup −1}, respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T{sub r} = 0.098 g{sub Ni} min mL{sup −1}. After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T{sub r} = 0.098 g{sub Ni} min mL{sup −1}, attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity.

Aluminum anode for aluminum-air battery - Part I: Influence of aluminum purity

Science.gov (United States)

Cho, Young-Joo; Park, In-Jun; Lee, Hyeok-Jae; Kim, Jung-Gu

2015-03-01

2N5 commercial grade aluminum (99.5% purity) leads to the lower aluminum-air battery performances than 4N high pure grade aluminum (99.99% purity) due to impurities itself and formed impurity complex layer which contained Fe, Si, Cu and others. The impurity complex layer of 2N5 grade Al declines the battery voltage on standby status. It also depletes discharge current and battery efficiency at 1.0 V which is general operating voltage of aluminum-air battery. However, the impurity complex layer of 2N5 grade Al is dissolved with decreasing discharge voltage to 0.8 V. This phenomenon leads to improvement of discharge current density and battery efficiency by reducing self-corrosion reaction. This study demonstrates the possibility of use of 2N5 grade Al which is cheaper than 4N grade Al as the anode for aluminum-air battery.

Puesta en valor de algunas construcciones del ing. Salamone

OpenAIRE

Traversa, Luis P.; Di Maio, Ángel A; Longoni, René

2003-01-01

En Enero del año 2002, la Legislatura bonaerense sancionó la ley n° 12.854, que declaró Patrimonio provincial a la obra pública municipal del ingeniero Francisco Salamone (1898-1959), construída durante el Gobierno de Manuel Fresco (1936-1940). De casi un centenar de construcciones y proyectos realizados dentro de lo que se denominó Plan de Obras Públicas Municipales, en más de 20 localidades pertenecientes a 16 Partidos del interior bonaerense, al menos, una treintena de ellas son signifi...

Arte rupestre paleolítico y postpaleolítico al aire libre en los Montes de Toledo occidentales (Toledo, Castilla - La Mancha, España: noticia preliminar

Directory of Open Access Journals (Sweden)

Jesús F. JORDÁ PARDO

2009-12-01

Full Text Available RESUMEN: Se dan a conocer en este trabajo los grabados y pinturas rupestres localizados recientemente en el extremo occidental de los Montes de Toledo (comarca toledana de La Jara en la vertiente meridional de la Cuenca del Tajo. Una primera zona, situada en el valle del río Huso, se desarrolla al aire libre sobre afloramientos de pizarras y en ella se localizan al menos dos conjuntos rupestres: uno caracterizado por grabados de trazo fino atribuidos al Paleolítico Superior y otro realizado mediante diversas técnicas de grabado con una cronología muy amplia desde la Prehistoria reciente hasta épocas históricas. La segunda zona corresponde al valle del río Gévalo y por el momento corresponde a un único gran abrigo desarrollado en cuarcitas en cuyas paredes aparecen pinturas rojas atribuibles a la Prehistoria reciente sobre las que se superponen grabados de trazo fino y repiqueteado con elementos claramente prehistóricos y otros con un marcado carácter histórico.ABSTRACT: This paper deals with rock art findings recently located on the Western edge of Toledo Mountains at the Southern slope of Tagus Basin. The first finding área, placed in the valley of the Huso River, is an open air rock art site on shale outcrop where two main groups of patterns may be seen: fine - line engravings from Upper Palaeolithic times as well as several motifs using various engraving techniques rahging a wider time span from later prehistoric ages to historical times. The second área lies in the valley of the Gévalo River and is a large quartzite rock shelter containing on his walls red paintings dated on Postpalaeolithic times that placed under engravings made using fine-line and beating techbiques both from prehistórica! and historical ages.

Communicating Why: Aligning the Air Force Message

Science.gov (United States)

2015-02-17

Mart, Dell, Starbucks , and even Apple when Steve Jobs retired the first time).21 In other words, to discover and articulate the Air Force’s WHY... Corporation , 2012), iii. 18 Ibid., 9. 19 Squadron Officer School Think Tank Class 14E, “Changing the Air Force Narrative” (Maxwell AFB, AL: Squadron...Through: The Search for a Strong, Unified Culture for America’s Airmen.” Santa Monica, CA: RAND Corporation , 2012. United States Air Force. “United

Oxidation behavior of Al/Cr coating on Ti2AlNb alloy at 900 °C

Science.gov (United States)

Yang, Zhengang; Liang, Wenping; Miao, Qiang; Chen, Bowen; Ding, Zheng; Roy, Nipon

2018-04-01

In this paper, the Al/Cr coating was fabricated on the surface of Ti2AlNb alloy via rf magnetron sputtering and double glow treatment to enhance oxidation resistance. The protective coating with an outer layer of Al and inner layer of Cr has great bonding strength due to the in-diffusion of Cr and the inter-diffusion between Al and Cr to form Al-Cr alloyed layer which has great hardness. Acoustic emission curve which was detected via WS-2005 scratch tester indicates the bonding strength between Al/Cr coating and substrate is great. Morphology of Ti2AlNb alloy with Al/Cr coating after scratch test shows that the scratch is smooth without disbanding, and the depth and breadth of scratch are changed uniformly. The mass change was reduced after oxidation test due to the Al/Cr protective coating. Isothermal oxidation test at 900 °C was researched. Results indicate that Al/Cr coating provided oxidation resistance of Ti2AlNb alloy with prolonged air exposure at 900 °C. Al2O3 was detected by XRD patterns and SEM images, and was formed on the surface of Ti2AlNb alloy to protect substrate during oxidation test. A certain content of Cr is beneficial for the formation of Al2O3. Besides, Cr2O3 was produced under Al2O3 by outward diffusion of Cr to protect substrate sequentially, no cracks were discovered on Al/Cr protective coating. The process of Ti outward diffusion into surface was suppressive due to integration of Cr-Ti and Al-Ti intermetallics. A steady, adherent and continuous coated layer of Al/Cr on Ti2AlNb alloy increases oxidation resistance.

Los nuevos desafíos de la puesta en práctica de las políticas de saneamiento ambiental

Directory of Open Access Journals (Sweden)

Chamizo Garcia, Horacio Alejandro

2009-07-01

Full Text Available Se presentan los resultados más importantes de una revisión bibliográfica sobre el tema de análisis de la gestión de políticas de saneamiento ambiental en asentamientos humanos. La revisión se propuso identificar factores determinantes de la gestión en estudios realizados en diversos países y particularmente en América Latina, tomando como referencia el neoinstitucionalismo y sus vertientes teóricas histórica, sociológica, normativa y de elección racional racional. Como principales resultados se identifica el papel que tiene la resistencia por parte de actores estratégicos frente a las nuevas ideas así como la influencia de los paradigmas dominantes y su socialización. Se constata también la influencia que tiene el marco normativo formal y particularmente el diseño de los espacios de interacción intersectorial en el abordaje del saneamiento ambiental desde una perspectiva compleja. Así mismo, se evidencia el papel de las relaciones de agencia en condiciones de cuasimercados y su influencia en la conformación de redes de actores. Los hallazgos explican integradamente los principales factores que influyen durante la puesta práctica políticas públicas de gran relevancia para la salud de la población y la reducción de inequidades sociales.

La Argentina y el Plan Marshall: promesas y realidades Argentina and the Marshall Plan: promises and realities

Directory of Open Access Journals (Sweden)

Mario Rapoport

2009-06-01

Full Text Available El artículo analiza los intereses y prioridades de la política económica externa de los Estados Unidos y las complejas relaciones entre Washington y el gobierno de Buenos Aires en relación a la puesta en marcha del Plan Marshall de reconstrucción de Europa Occidental. La no participación de la Argentina en él dificultó su proceso de industrialización al restringir su comercio con el viejo continente e impedirle obtener las divisas necesarias para comprar en los EEUU, proveedor fundamental de los bienes que necesitaba.The article analyze both the interests and priorities of the foreign economic policy of the United States and the complex relationship between Washington and the peronist government when President Truman impose the Marshall Plan in Europe making more difficult the industrialisation of Argentina.

Equivalencia aproximada entre las resistencias a la compresión de los morteros de cemento Portland según los Pliegos españoles de 1930, 1960 y algunas Normas extranjeras

Directory of Open Access Journals (Sweden)

Calleja, J.

1961-09-01

Full Text Available Not availableCuando por razones de modernización y puesta al día de las prescripciones y normas de ensayo de un determinado material, por ejemplo el cemento se cambian las especificaciones relativas al mismo, es de todo punto interesante conocer la equivalencia entre las resistencias mecánicas de un mismo cemento ensayado según los métodos antiguos que se abandonan y según los modernos que se adoptan.

The Effect of Mg Addition and Manufacturing Conditions on the Interfacial Reactions between Al and CNT in Al-CNT Pellets

International Nuclear Information System (INIS)

Lim, Jung-Kyu; Choi, Soon-Yool; Choe, Kyong-Hwan; Cho, Gue-Serb; Kim, Sang-Sub

2013-01-01

In the present study, Al-CNT pellets were investigated to understand the effect of Mg addition and manufacturing conditions on the interfacial reactions between Al and CNTs in Al-CNT pellets. The pellets were heated and held at 700 °C and 800 °C for 2 hours under nitrogen (N_2) atmosphere. To confirm the reactions between Al and CNT in the pellets under different manufacturing conditions, the microstructures were observed by optical microscopy (OM) and field emission scanning electro microscopy (FESEM). And, the composition and reaction phases were analyzed by energy dispersive X-ray spectroscory (EDXS) and X-ray diffractometry (XRD). The presence of oxidation products and Mg on the surface of Al powder in the pellets appeared to prevent the formation of Al_4C_3. But, Al_4C_3 reaction products were increased due to the high temperature of 800 °C, which produced a high amount of reduced aluminium and increased the reaction areas between Al and CNT. The Al-CNT pellets compacted under air atmosphere prohibited the reaction between Al and CNT because of the high amount of oxidation products, such as MgO and MgAl_2O_4.

Effect of polymorphism of Al2O3 on the sintering and microstructure of transparent MgAl2O4 ceramics

Science.gov (United States)

Han, Dan; Zhang, Jian; Liu, Peng; Wang, Shiwei

2017-09-01

Transparent MgAl2O4 ceramics were fabricated by reactive sintering in air followed by hot isostatic press treatment using commercial Al2O3 powder (γ-Al2O3 or α-Al2O3) and MgO powder as raw materials. The densification rate, microstructure and optical properties of the ceramics were investigated. Densification temperature of the sample from γ-Al2O3/MgO was lower than that from α-Al2O3/MgO. However, in-line transmission (2 mm thick) of the sample from α-Al2O3/MgO at the wavelength of 600 nm and 1100 nm were respectively 77.7% and 84.3%, higher than those (66.7%, 81.4%) of the sample from γ-Al2O3/MgO. SEM observation revealed that the sample from α-Al2O3/MgO exhibited a homogeneous and pore-free microstructure, while, the sample from γ-Al2O3/MgO showed an apparent bimodal microstructure containing pores.

Notes on the Start-Up of the Latina Power Station; Notes concernant le demarrage de la centrale nucleaire de Latina; Zapusk ehlektrostantsii Latina; Notas sobre la puesta en marcha de la central electrica de Latina

Energy Technology Data Exchange (ETDEWEB)

Calabria, G.; Gualtieri, G. [AGIP Nucleare, Milano (Italy)

1963-10-15

desarrollo de los ensayos finales, sobre la carga del combustible y el orden en que se ejecutaron las operaciones de puesta en marcha y sobre las determinaciones y maniobras de regulacion posteriores al estado critico. Se resenan asimismo las operaciones iniciales de generacion y conexion de la central con la red electrica. Por ultimo, se mencionan los problemas de organizacion derivados de la explotacion de la central, incluyendo la preparacion y formacion profesional del personal y las medidas de seguridad adoptadas. (author) [Russian] Privoditsya informatsiya o zapuske pervoj ital'yanskoj atomnoj ehlektrostantsii Latina moshchnost'yu 200 mgvt. Reaktor rabotaet na prirodnom urane s grafitovym zamedlitelem i gazovym okhlazhdeniem. Posle kratkogo opisaniya osnovnykh kharakteristik ehlektrostantsii privodyatsya podrobnye dannye otnositel'no provedeniya zaklyuchitel'nykh ispytanij stantsii'', toplivnoj zagruzki i poryadka ehkspluatatsii, izmerenij i upravleniya s dovedeniem do kriticheskogo sostoyaniya. Daetsya ob''yasnenie raboty po zapusku i vklyucheniyu stantsii v ehlektroset'. Izlagayutsya takzhe problemy, svyazannye s ehkspluatatsiej stantsii, v tom chisle podgotovka personela i ego kvalifikatsiya, mery po bezopasnosti. (author)

High performance LiNi0.5Mn1.5O4 cathode by Al-coating and Al3+-doping through a physical vapor deposition method

International Nuclear Information System (INIS)

Sun, Peng; Ma, Ying; Zhai, Tianyou; Li, Huiqiao

2016-01-01

Highlights: • Metal Al was used as an electrical conductive coating material for LiNi 0.5 Mn 1.5 O 4 . • The uniform surface coating layer of metal Al was successfully achieved with adjusted thickness through a physical vapor deposition technology. • Al 3+ -doped LiNi 0.5 Mn 1.5 O 4 can be easily obtained by further directly annealing of Al-coated LiNi 0.5 Mn 1.5 O 4 in air. • The conductive Al-coating layer can greatly improve the rate performance and cycle stability of LiNi 0.5 Mn 1.5 O 4 . - Abstract: In this work, spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) hollow microspheres are synthesized by an impregnation method using microsphere MnO 2 as both the precursor and template. To enhance the electrical conductivity of LNMO, metal Al was employed for the first time as a coating material for LNMO. Though an Electron-beam Vapor Deposition approach, the surface of LNMO can be easily coated by a tight layer of Al nanoparticles with adjusted thickness. Further annealing the Al-coated sample at 800 °C in air, the Al 3+ -doped LNMO can be obtained. The effects of Al-coating and Al 3+ -doping on the sample morphology and structure are investigated by SEM, TEM, XRD and FT-IR. The electrochemical properties of Al-coated LNMO and Al 3+ -doped LNMO are measured with comparison of bare LNMO by charge/discharge tests and electrochemical impedance spectroscopy (EIS). The results show that both Al-coating and Al 3+ -doping can greatly enhance the cycle performance and rate capability of LNMO. Especially for Al-coated LNMO, it shows the lowest battery impedance due to the existence of conductive Al coating layer, thus delivers the best rate performance among the three. The physical coating procedure used in this work may provide a new facile modification approach for other cathode materials.

Exposure to hazardous air pollutants and the risk of amyotrophic lateral sclerosis

International Nuclear Information System (INIS)

Malek, Angela M.; Barchowsky, Aaron; Bowser, Robert; Heiman-Patterson, Terry; Lacomis, David; Rana, Sandeep; Ada Youk; Talbott, Evelyn O.

2015-01-01

Background: Amyotrophic lateral sclerosis (ALS) is a serious and rapidly fatal neurodegenerative disorder with an annual incidence of 1–2.6/100,000 persons. Few known risk factors exist although gene–environment interaction is suspected. We investigated the relationship between suspected neurotoxicant hazardous air pollutants (HAPs) exposure and ALS. Methods: A case–control study involving sporadic ALS cases (n = 51) and matched controls (n = 51) was conducted from 2008 to 2011. Geocoded residential addresses were linked to U.S. EPA NATA data (1999, 2002, and 2005) by census tract. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Results: Residential exposure to aromatic solvents significantly elevated the risk of ALS among cases compared to controls in 2002 (OR = 5.03, 95% CI: 1.29, 19.53) and 1999 (OR = 4.27, 95% CI: 1.09, 16.79) following adjustment for education, smoking, and other exposure groups. Metals, pesticides, and other HAPs were not associated with ALS. Conclusions: A potential relationship is suggested between residential ambient air aromatic solvent exposure and risk of ALS in this study. - Highlights: • The effects of ambient air pollutants and risk of ALS was assessed. • EPA NATA data linked to geocoded addresses for 1999, 2002, and 2005. • Residential exposure to aromatic solvents was associated with an increased risk of ALS. - Residential exposure to aromatic solvents was associated with an increased risk of ALS

Microstructural Evolution of NiCoCrAlHfYSi and NiCoCrAlTaY Coatings Deposited by AC-HVAF and APS

Science.gov (United States)

Han, Yujun; Chen, Hongfei; Gao, Dong; Yang, Guang; Liu, Bin; Chu, Yajie; Fan, Jinkai; Gao, Yanfeng

2017-12-01

The chemical composition of NiCoCrAlHfYSi with a suitable particle size, deposited using an activated combustion-high velocity air fuel (AC-HVAF) spray, is a potentially promising process because dense, continuous and pure alumina can be formed on the surface of the MCrAlY metallic coatings after isothermal oxidation exposure. The NiCoCrAlHfYSi (Amdry386) and NiCoCrAlTaY (Amdry997) coatings were produced using AC-HVAF and APS, respectively. Isothermal oxidation was subsequently conducted at 1050 °C in air for 200 h. This paper compares the characteristics of four coated samples, including the surface roughness, elastic modulus, hardness, oxide content, microstructural characteristics and phase evolution of thermally grown oxides (TGO). The growth of both the TGO and alumina scales in the TGO of the HVAF386 coating was relatively rapid. The θ- to α-alumina phase transformation was strongly determined by the Hf and Si dopants in the HVAF386 coating. Finally, the extent of grain refinement and deformation storage energy in the HVAF997 coatings were determined to be significantly crucial for the θ- to α-alumina phase transformation.

Magnesium, Iron and Aluminum in LLNL Air Particulate and Rain Samples with Reference to Magnesium in Industrial Storm Water

Energy Technology Data Exchange (ETDEWEB)

Esser, Bradley K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bibby, Richard K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fish, Craig [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-08-25

Storm water runoff from the Lawrence Livermore National Laboratory’s (LLNL’s) main site and Site 300 periodically exceeds the Discharge Permit Numeric Action Level (NAL) for Magnesium (Mg) under the Industrial General Permit (IGP) Order No. 2014-0057-DWQ. Of particular interest is the source of magnesium in storm water runoff from the site. This special study compares new metals data from air particulate and precipitation samples from the LLNL main site and Site 300 to previous metals data for storm water from the main site and Site 300 and alluvial sediment from the main site to investigate the potential source of elevated Mg in storm water runoff. Data for three metals (Mg, Iron {Fe}, and Aluminum {Al}) were available from all media; data for additional metals, such as Europium (Eu), were available from rain, air particulates, and alluvial sediment. To attribute source, this study compared metals concentration data (for Mg, Al, and Fe) in storm water and rain; metal-metal correlations (Mg with Fe, Mg with Al, Al with Fe, Mg with Eu, Eu with Fe, and Eu with Al) in storm water, rain, air particulates, and sediments; and metal-metal ratios ((Mg/Fe, Mg/Al, Al/Fe, Mg/Eu, Eu/Fe, and Eu/Al) in storm water, rain, air particulates and sediments. The results presented in this study are consistent with a simple conceptual model where the source of Mg in storm water runoff is air particulate matter that has dry-deposited on impervious surfaces and subsequently entrained in runoff during precipitation events. Such a conceptual model is consistent with 1) higher concentrations of metals in storm water runoff than in precipitation, 2) the strong correlation of Mg with Aluminum (Al) and Iron (Fe) in both storm water and air particulates, and 3) the similarity in metal mass ratios between storm water and air particulates in contrast to the dissimilarity of metal mass ratios between storm water and precipitation or alluvial sediment. The strong correlation of Mg with Fe and Al

The effect of crystal orientation on the aluminum anodes of the aluminum-air batteries in alkaline electrolytes

Science.gov (United States)

Fan, Liang; Lu, Huimin; Leng, Jing; Sun, Zegao; Chen, Chunbo

2015-12-01

Recently, aluminum-air (Al-air) batteries have received attention from researchers as an exciting option for safe and efficient batteries. The electrochemical performance of Aluminum anode remains an active area of investigation. In this paper, the electrochemical properties of polycrystalline Al, Al (001), (110) and (111) single crystals are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 4 M NaOH and KOH. Hydrogen corrosion rates of the Al anodes are determined by hydrogen collection. Battery performance using the anodes is tested by constant current discharge at 10 mA cm-2. This is the first report showing that the electrochemical properties of Al are closely related to the crystallographic orientation in alkaline electrolytes. The (001) crystallographic plane has good corrosion resistance but (110) is more sensitive. Al (001) single crystals display higher anode efficiency and capacity density. Controlling the crystallographic orientation of the Al anode is another way to improve the performance of Al-air batteries in alkaline electrolytes.

Synthesis cathode material LiNi0.80Co0.15Al0.05O2 with two step solid-state method under air stream

Science.gov (United States)

Xia, Shubiao; Zhang, Yingjie; Dong, Peng; Zhang, Yannan

2014-01-01

A facile generic strategy of solid-state reaction under air atmosphere is employed to prepare LiNi0.8Co0.15Al0.05O2 layer structure micro-sphere as cathodes for Li-ion batteries. The impurity phase has been eliminated wholly without changing the R-3m space group of LiNi0.8Co0.15Al0.05O2. The electrochemical performance of LiNi0.8Co0.15Al0.05O2 cathodes depend on the sintering step, temperature, particle size and uniformity. The sample pre-sintered at 540 °C for 12 h and then sintered at 720 °C for 28 h exhibits the best electrochemical performance, which delivers a reversible capacity of 180.4, 165.8, 154.7 and 135.6 mAhg-1 at 0.2 C, 1 C, 2 C and 5 C, respectively. The capacity retention keeps over 87% after 76 cycles at 1 C. This method is simple, cheap and mass-productive, and thus suitable to large scale production of NCA cathodes directly used for lithium ion batteries.

Mercury embrittlement of Cu-Al alloys under cyclic loading

Science.gov (United States)

Regan, T. M.; Stoloff, N. S.

1977-01-01

The effect of mercury on the room temperature, high cycle fatigue properties of three alloys: Cu-5.5 pct Al, Cu-7.3 pct Al, and Cu-6.3 pct Al-2.5 pct Fe has been determined. Severe embrittlement under cyclic loading in mercury is associated with rapid crack propagation in the presence of the liquid metal. A pronounced grain size effect is noted under mercury, while fatigue properties in air are insensitive to grain size. The fatigue results are discussed in relation to theories of adsorption-induced liquid metal embrittlement.

Evaluation of aerial microbial pollutants in Al-Haram Al-Nabawi during pilgrimage of 2013

Directory of Open Access Journals (Sweden)

Kholoud M. Alananbeh

2017-01-01

Full Text Available Al-Madinah Al-Munawwarah is the second holiest site in Islam. The possibility of new emerging microbes is valid due to the increased number of pilgrims. The objectives of the current study were to estimate the numbers of fungi and bacteria inside and outside Al-Haram Al-Nabawi and to find whether new bacterial and fungal species have emerged compared to previous studies. Air samples were collected twice a day from 12 spots and four directions during the pilgrim year of 2013 for four consecutive weeks by using the sedimentation method. Thirty five genera and fifty eight species were identified. The most recovered bacterial genera were Staphylococcus, Micrococcus, Bacillus, and Dermacoccus with 32.47%, 18.18%, 12.85%, and 11.23%, respectively. Fifty nine isolates of fungi were molecularly identified. Aspergillus species had the highest percentage (78%. The other fungal genera identified (Alternaria triticina, Emericella nidulans, Emericella striata, Mucor circinelloides, Penicillium chrysogenum, Penicillium minioluteum, Rhizopus arrhizus, Rhizopus oryzae, and Syncephalastrum racemosum had less than 5% frequency. In places such as Al-Haram Al-Nabawi, a large and crowded public (millions exist especially during pilgrimages and Ramadan, thus, exposure to microorganisms is high. On the other hand, microorganism infectivity depends on many factors including their virulence, landing site, and person’s immunity. For those reasons, many aspects should be considered to avoid aerosol contaminants.

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction.

Science.gov (United States)

Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A; García, Juan

2013-01-15

Active nickel catalysts (7 wt%) supported over Mg-Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min(-1) and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min(-1), respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T(r)=0.098 g(Ni) min mL(-1). After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T(r)=0.098 g(Ni) min mL(-1), attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Optimization of the boron content in FeAl (40 at. % Al) alloys

International Nuclear Information System (INIS)

Webb, G.; Juliet, P.; Lefort, A.

1993-01-01

FeAl intermetallic alloys are of interest for several high temperature applications due to excellent oxidation resistance, low density, and relatively low cost. Attempts to further increase the ductility of iron-rich FeAl have met with, at best, marginal success. Of the ductilization techniques employed, B doping appears to be a promising method for obtaining enhanced ductility and high strength in iron rich FeAl. Boron additions enhance the ductility of these alloys by increasing the grain boundary cohesive strength which reduces the tendency for intergranular fracture. The goal of the present work was to determine the optimum B concentration for increasing ambient temperature ductility. To accomplish this, a series of three iron rich FeAl alloys of similar Fe stoichiometries were doped with different levels of B (0,12, and 80 wppm). Secondary ion mass spectrometry (SIMS) was conducted on these alloys for evaluation of the B partitioning after consolidation by extrusion. Ambient temperature tensile testing and SEM fractography were then used to evaluate the effect of such additions on ambient temperature ductility in air. The results of these experiments indicate that optimum ductility is obtained from a homogeneous distribution of boron in which boride precipitation is limited

A comparative wear study on Al-Li and Al-Li/SiC composite

Energy Technology Data Exchange (ETDEWEB)

Okumus, S. Cem, E-mail: cokumus@sakarya.edu.tr; Karslioglu, Ramazan, E-mail: cokumus@sakarya.edu.tr; Akbulut, Hatem, E-mail: cokumus@sakarya.edu.tr [Sakarya University Engineering Faculty, Department of Metallurgical and Materials Engineering, Esentepe Campus, 54187, Sakarya (Turkey)

2013-12-16

Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al{sub 2}O{sub 3} ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms{sup −1} and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

Performance of a rapidly-refuelable aluminum-air battery

Science.gov (United States)

Levy, D. J.; Hollandsworth, R. P.; Gonzales, E. M.; Littauer, E. L.

The Al-air battery is being developed to provide an electric vehicle with conventional automobile performance. A rapidly-refuelable, 6-cell battery (200-sq cm electrodes) was evaluated. RX-808 aluminum anodes and air cathodes were used with a flowing alkaline electrolyte. Peak power was found to increase with temperature, decrease with aluminate concentration and be unaffected by electrolyte flow. The best performance was 5.28 kW/sq m peak power density, 2.08 kWh/kg Al energy density and 80 percent coulombic efficiency. Anode refueling is rapid and 100 percent utilization is achieved. Additional evaluation included cathode catalysts, a thermal balance and monitoring electrolyte composition.

Influence of air and vacuum environment on fatigue behavior of Zr-based bulk metallic glasses

International Nuclear Information System (INIS)

Wang, G.Y.; Liaw, P.K.; Yokoyama, Y.; Peter, W.H.; Yang, B.; Freels, M.; Buchanan, R.A.; Liu, C.T.; Brooks, C.R.

2007-01-01

High-cycle fatigue (HCF) experiments in air and vacuum at room temperature were conducted on zirconium (Zr)-based bulk-metallic glasses (BMGs): Zr 50 Cu 40 Al 10 , Zr 50 Cu 30 Al 10 Ni 10 , and Zr 50 Cu 37 Al 10 Pd 3 in atomic percent. The fatigue-endurance limit of Zr 50 Cu 37 Al 10 Pd 3 was found to be significantly greater than those of Zr 50 Cu 40 Al 10 and Zr 50 Cu 30 Al 10 Ni 10 , which indicates that the inclusions of Pd and the resulting nano structures improve the fatigue resistances of the Zr-based BMGs. The fatigue lives in vacuum and air were generally found to be comparable

Nitrogen-doped carbonaceous catalysts for gas-diffusion cathodes for alkaline aluminum-air batteries

Science.gov (United States)

Davydova, E. S.; Atamanyuk, I. N.; Ilyukhin, A. S.; Shkolnikov, E. I.; Zhuk, A. Z.

2016-02-01

Cobalt tetramethoxyphenyl porphyrin and polyacrylonitrile - based catalysts for oxygen reduction reaction were synthesized and characterized by means of SEM, TEM, XPS, BET, limited evaporation method, rotating disc and rotating ring-disc electrode methods. Half-cell and Al-air cell tests were carried out to determine the characteristics of gas-diffusion cathodes. Effect of active layer thickness and its composition on the characteristics of the gas-diffusion cathodes was investigated. Power density of 300 mW cm-2 was achieved for alkaline Al-air cell with an air-breathing polyacrylonitrile-based cathode.

La tutela efectiva de la creación de contenidos e-learning: una solución en las excepciones al derecho de autor

OpenAIRE

López Rodríguez, Fernando; Peire Arroba, Juan

2015-01-01

La evolución de la tecnología ha llevado, necesariamente, a un desarrollo de los derechos de autor y de la Propiedad Intelectual. Estas evidencias se refieren a la relevancia por la puesta en funcionamiento de las plataformas tecnológicas en relación

Hot Corrosion Behavior of Stainless Steel with Al-Si/Al-Si-Cr Coating

Science.gov (United States)

Fu, Guangyan; Wu, Yongzhao; Liu, Qun; Li, Rongguang; Su, Yong

2017-03-01

The 1Cr18Ni9Ti stainless steel with Al-Si/Al-Si-Cr coatings is prepared by slurry process and vacuum diffusion, and the hot corrosion behavior of the stainless steel with/without the coatings is studied under the condition of Na2SO4 film at 950 °C in air. Results show that the corrosion kinetics of stainless steel, the stainless steel with Al-Si coating and the stainless steel with Al-Si-Cr coating follow parabolic laws in several segments. After 24 h corrosion, the sequence of the mass gain for the three alloys is the stainless steel with Al-Si-Cr coating coating coating. The corrosion products of the three alloys are layered. Thereinto, the corrosion products of stainless steel without coating are divided into two layers, where the outside layer contains a composite of Fe2O3 and FeO, and the inner layer is Cr2O3. The corrosion products of the stainless steel with Al-Si coating are also divided into two layers, of which the outside layer mainly consists of Cr2O3, and the inner layer is mainly SiO2. The corrosion film of the stainless steel with Al-Si-Cr coating is thin and dense, which combines well with substrate. Thereinto, the outside layer is mainly Cr2O3, and the inside layer is Al2O3. In the matrix of all of the three alloys, there exist small amount of sulfides. Continuous and protective films of Cr2O3, SiO2 and Al2O3 form on the surface of the stainless steel with Al-Si and Al-Si-Cr coatings, which prevent further oxidation or sulfide corrosion of matrix metals, and this is the main reason for the much smaller mass gain of the two alloys than that of the stainless steel without any coatings in the 24 h hot corrosion process.

Public Communication on Urban Air Pollution; La Comunicacion al Publico sobre Contaminacion Atmosferica Urbana

Energy Technology Data Exchange (ETDEWEB)

Otra, C.; Sala, R.

2014-02-01

The aim of this study was to analyze the state of public information in the field of air pollution in Spain. We conducted semi-structured interviews with members of public agencies, technical experts, scientists, and members of non governmental associations together with a documentary analysis of air pollution documents (plans, reports, etc.). We tried to characterize the information actions on air quality carried out in Spanish cities during the last years. In the results section we first analyze the ideas, concerns and considerations that underlie the actions of public information on air pollution, as well as the main challenges of public communication on this subject, according to the documents and the different experts consulted. We analyze the various contents of information transmitted nowadays (on levels of pollution, health impacts and mitigation or protection actions), as well as the mechanisms by which it is communicated, both continuously and in the case of threshold overcoming episodes. We also review the different media used to communicate air pollution information (Internet, mobile applications and other forms) and other issues such as information audiences, or the perceived impacts of information provided. Finally, the implications for more diverse and effective public involvement strategies in air pollution are discussed. (Author)

Y-Si-Al-O-N Glass Fibers.

Science.gov (United States)

The excellent mechanical properties and outstanding water corrosion resistance of Y -Si-Al-O- N glasses indicate that they are attractive candidate...materials for forming into high performance glass fibers. Fibers of glasses containing, respectively,3.2 and 6.6 wt% N were drawn freehand in air, and

Interaction of Al with O2 exposed Mo2BC

International Nuclear Information System (INIS)

Bolvardi, Hamid; Music, Denis; Schneider, Jochen M.

2015-01-01

Highlights: • Al adheres to many surfaces. • Solid–solid interactions challenging for real (oxidized) surfaces. • Dissociative O 2 adsorption on Mo 2 BC(0 4 0). • Al nonamer is disrupted on oxidized Mo 2 BC(0 4 0). • Adhesion of a residual Al on the native oxide. - Abstract: A Mo 2 BC(0 4 0) surface was exposed to O 2 . The gas interaction was investigated using ab initio molecular dynamics and X-ray photoelectron spectroscopy (XPS) of air exposed surfaces. The calculations suggest that the most dominating physical mechanism is dissociative O 2 adsorption whereby Mo−O, O−Mo−O and Mo 2 −C−O bond formation is observed. To validate these results, Mo 2 BC thin films were synthesized utilizing high power pulsed magnetron sputtering and air exposed surfaces were probed by XPS. MoO 2 and MoO 3 bond formation is observed and is consistent with here obtained ab initio data. Additionally, the interfacial interactions of O 2 exposed Mo 2 BC(0 4 0) surface with an Al nonamer is studied with ab initio molecular dynamics to describe on the atomic scale the interaction between this surface and Al to mimic the interface present during cold forming processes of Al based alloys. The Al nonamer was disrupted and Al forms chemical bonds with oxygen contained in the O 2 exposed Mo 2 BC(0 4 0) surface. Based on the comparison of here calculated adsorption energy with literature data, Al−Al bonds are shown to be significantly weaker than the Al−O bonds formed across the interface. Hence, Al−Al bond rupture is expected for a mechanically loaded interface. Therefore the adhesion of a residual Al on the native oxide layer is predicted. This is consistent with experimental observations. The data presented here may also be relevant for other oxygen containing surfaces in a contact with Al or Al based alloys for example during forming operations

Numerical Simulation of Spheroidization Process of TiAl Alloy Powders in Radio Frequency Plasma

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ZHU Langping

2017-06-01

Full Text Available A numerical simulation method was used to study the radio frequency plasma spheroidization process of TiAl alloy powder. The effects of velocity field and temperature field on the motion trajectory and mass change of TiAl alloy powder with different particle size were analyzed.The results show that the temperature of powder particles increases rapidly under high temperature plasma, surface evaporation cause the reduction of particle size, and particles with small size tend to evaporate quickly. The motion trajectory of particles with different sizes in the lower end of the cooling tube is different obviously, small particles tend to enter the air outlet,while the larger particles are easy to fall down to the bottom of the cooling tube to be collected. Increasing air flow rate can improve the velocity of air flow in the spheroidizing system, causing larger particles to be taken away by the air, resulting in yield reduction. The simulation results of TiAl alloy powder spheroidization are close to the experimental results refer to parameters such as powder size distribution, average particle size and powder yield, and the model is in good accordance with the actual process of the spheroidization.

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.

Oxidation behaviour of a Ti2AlN MAX-phase coating

International Nuclear Information System (INIS)

Wang Qimin; Kim, Kwangho; Garkas, W; Renteria, A Flores; Leyens, C; Sun Chao

2011-01-01

In this paper, we reported the oxidation behaviour of Ti 2 AlN coatings on a -TiAl substrate. The coatings composed mainly of Ti 2 AlN MAX phase were obtained by magnetron sputtering and subsequent vacuum annealing. Isothermal oxidation tests at 700-900 deg. C were performed in air. The results indicated that the oxidation resistance of the -TiAl alloy can be improved by depositing a Ti 2 AlN layer on the alloy surface, especially at high temperatures. An Al-rich oxide scale formed on the coating surfaces during oxidation. This scale acts as diffusion barrier blocking the ingress of oxidation, and effectively protects the coated alloys from further oxidation attack.

La Fiesta de la Historia, de la Universidad a la ciudadanía: puesta en valor de la Historia y el Patrimonio = The “Feast of History”, from the University to the citizenship: an enhancement of History and Heritage

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Olga Moreno-Fernández

2018-01-01

Full Text Available Resumen: La Fiesta de la Historia nace en Bolonia y se extiende, entre otras ciudades, a Sevilla. En ella juegan un papel fundamental la escuela, la universidad, las instituciones y las asociaciones culturales que, junto a expertos y estudiosos, van a mostrar a la sociedad y a recordar las raíces de dónde venimos, permitiendo poner en valor la historia de la ciudad y el territorio. Es una semana en que las plazas, las calles, teatros y centros escolares y administrativos de las ciudades participantes sirven de escenario para celebrar conferencias, mesas redondas, espectáculos y exposiciones. Estas actividades permiten acercar a la ciudadanía a la historia y al patrimonio de la ciudad. Presentamos las experiencias de Bolonia y presentamos y valoramos la puesta en marcha de la iniciativa en Sevilla, dos iniciativas que surgen desde la Universidad. Abstract:  The “Feast of History” originated in Bologna and extended, among other cities, to Seville. School, college, institutions and cultural associations, together with experts and scholars, play a key role in this Feast and try to make society remember its roots, allowing to value history of the city and territory. For a week the squares, streets, theaters, schools and administrative centers of the participating cities are the setting for lectures, panel discussions, performances and exhibitions. These activities aim at bringing the history and heritage of the city to participants. We present the experiences of Bologna and the initiative of Seville, both initiatives arising from the University.

Stratospheric measurements of ozone-depleting substances and greenhouse gases using AirCores

Science.gov (United States)

Laube, Johannes; Leedham Elvidge, Emma; Kaiser, Jan; Sturges, Bill; Heikkinen, Pauli; Laurila, Tuomas; Hatakka, Juha; Kivi, Rigel; Chen, Huilin; Fraser, Paul; van der Veen, Carina; Röckmann, Thomas

2017-04-01

Retrieving air samples from the stratosphere has previously required aircraft or large balloons, both of which are expensive to operate. The novel "AirCore" technique (Karion et al., 2010) enables stratospheric sampling using weather balloons, which is much more cost effective. AirCores are long (up to 200 m) stainless steel tubes which are placed as a payload on a small balloon, can ascend to over 30 km and fill upon descent, collecting a vertical profile of the atmosphere. Retrieved volumes are much smaller though, which presents a challenge for trace gas analysis. To date, only the more abundant trace gases such as carnon dioxide (CO2) and methane (CH4) have been quantified in AirCores. Halogenated trace gases are also important greenhouse gases and many also deplete stratospheric ozone. Their concentrations are however much lower i.e. typically in the part per trillion (ppt) molar range. We here present the first stratospheric measurements of halocarbons in AirCores obtained using UEA's highly sensitive (detection limits of 0.01-0.1 ppt in 10 ml of air) gas chromatography mass spectrometry system. The analysed air originates from a Stratospheric Air Sub-sampler (Mrozek et al., 2016) which collects AirCore segments after the non-destructive CO2 and CH4 analysis. Successfully measured species include CFC-11, CFC-12, CFC-113, CFC-115, H-1211, H-1301, HCFC-22, HCFC-141b, HCFC-142b, HCFC-133a, and sulphur hexafluoride (SF6). We compare the observed mixing ratios and precisions with data obtained from samples collected during various high-altitude aircraft campaigns between 2009 and 2016 as well as with southern hemisphere tropospheric long-term trends. As part of the ERC-funded EXC3ITE (EXploring stratospheric Composition, Chemistry and Circulation with Innovative Techniques) project more than 40 AirCore flights are planned in the next 3 years with an expanded range of up to 30 gases in order to explore seasonal and interannual variability in the stratosphere

In situ formation of CA6 platelets in Al2O3 and Al2O3/ZrO2 matrices

International Nuclear Information System (INIS)

Belmonte, M.; Sanchez-Herencia, A.J.; Moreno, R.; Miranzo, P.; Moya, J.S.; Tomsia, A.P.

1993-01-01

Al 2 O 3 and Al 2 O 3 /ZrO 2 compacts containing CaO as a dopant have been sintered under different conditions and atmospheres: air, high vacuum (> 10 -6 torr). SEM observations have been made on the polished surfaces of sintered and also of annealed samples. Only after the annealing treatment in air at temperatures ranging from 1400 to 1500 C, a massive formation of CA 6 platelets was detected in samples sintered in low oxygen partial pressure atmospheres. In order to clarify the mechanism of formation of this secondary phase at the grain boundaries, CaO has been introduced in the form of either plaster of Paris (to reproduce a possible contamination provided by the molds in slip casting) or CaCO 3 . The obtained results indicate the important role of the firing atmosphere on the precipitation of secondary phases at grain boundary. (orig.)

Ocupantes espontáneos y derechos por la tierra en la formación de “pueblos de españoles” (Rincón de San Pedro, Buenos Aires, 1740-1860

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Mariana Canedo

2015-01-01

Full Text Available Durante el siglo XVIII, se multiplicó la presencia de “pueblos de espa-ñoles” y villas en la frontera sur hispanoamericana. El protagonismo de ocupantes rurales en la formación de “pueblos de españoles” fue más frecuente en la campaña de Buenos Aires que en otras jurisdicciones, aunque poco se conoce sobre su proceder. El objetivo del artículo fue analizar las características de los ocupantes rurales y el rango de acción que tuvieron para solicitar el reconocimiento legal de terrenos para la formación de un pueblo en la campaña de Buenos Aires durante el siglo XVIII y parte del XIX. El análisis del caso del pueblo de San Pedro nos permitió profundizar la situación de los “ocupantes” y abrir varios inte-rrogantes sobre la regulación de los derechos por la tierra, particularmen-te sobre los pueblos y villas, en un período que suele estar vinculado a transformaciones en los derechos y en las relaciones de poder ejercidas en su puesta en práctica.

Comparative Study of the Corrosion Resistance of Air-Plasma-Sprayed Ca2SiO4 and Al2O3 Coatings in Salt Water

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Yuan Xiao

2018-03-01

Full Text Available In this study, Ca2SiO4 coating was sprayed on stainless steel substrate and the corrosion resistance of the as-sprayed coating was studied in salt water. At the same time, Al2O3 coatings were produced by air-plasma-sprayed technology as comparison. Immersion test was carried out to evaluate the protection performance of coatings. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS plots were also analyzed. The results indicated that Ca2SiO4 coatings showed a better protection performance than Al2O3 coatings. During the immersion, various calcium carbonate crystals appeared on the surface of Ca2SiO4 coatings. Ca(OH2 was released from Ca2SiO4 coatings into NaCl aqueous solution, increasing the alkalinity, which is in favor of the formation of passivation film, and thus improves the corrosion resistance. Ca2SiO4 coatings became denser after immersion due to the fact that the pores and micro cracks were filled with hydration products i.e., hydrated calcium silicate (C–S–H gel. On the contrary, the microstructure of Al2O3 coatings became loose and obvious rusty spots were observed on the surface after the immersion test.

Dermal uptake of nicotine from air and clothing: Experimental verification

DEFF Research Database (Denmark)

Bekö, Gabriel; Morrison, Glenn; Weschler, Charles J.

2017-01-01

Studies suggest that dermal uptake of certain semivolatile organic compounds (SVOC) directly from air can be a significant exposure pathway. This has been experimentally confirmed for two phthalates (Weschler et al., 2015). Morrison et al. (2016) showed that clean clothing can impede, while cloth...

Effect of Heat Treatment on Commercial AlSi12Cu1(Fe) and AlSi12(b) Aluminum Alloy Die Castings

Science.gov (United States)

Battaglia, E.; Bonollo, F.; Ferro, P.; Fabrizi, A.

2018-03-01

High-pressure die castings (HPDCs) cannot normally be heat-treated at a high temperature because of the presence of inner air/gas- or shrinkage-porosity that may lead to the formation of undesired surface blisters. In this paper, an unconventional heat treatment is proposed. Two secondary Al-Si alloys, AlSi12(b) and AlSi12Cu1(Fe), were stabilization heat-treated at 624 K (350 °C) with soaking times ranging from 1 to 8 hours. Enhancement of both static and dynamic mechanical properties was found to be related to the fragmentation of interconnected eutectic Si particles and the smoothing of coarser crystals. Increased ductility after heat treatment was correlated with a decrease in hardness and Si particle roundness. The formation of Si precipitates within the α-Al matrix was also observed.

Optical properties and thermal stability of TiAlN/AlON tandem absorber prepared by reactive DC/RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Barshilia, Harish C.; Selvakumar, N.; Rajam, K.S. [Surface Engineering Division, National Aerospace Laboratories, Bangalore 560 017 (India); Biswas, A. [Spectroscopy Division, Bhabha Atomic Research Center, Mumbai 400 085 (India)

2008-11-15

Spectrally selective TiAlN/AlON tandem absorbers were deposited on copper and stainless steel substrates using a reactive DC/RF magnetron sputtering system. The compositions and thicknesses of the individual component layers were optimized to achieve high absorptance ({alpha}=0.931-0.942) and low emittance ({epsilon}=0.05-0.06) on copper substrate. The experimental spectroscopic ellipsometric data have been fitted with the theoretical models to derive the dispersion of the optical constants (n and k). In order to study the thermal stability of the tandem absorbers, they were subjected to heat treatment (in air and vacuum) for different durations and temperatures. The tandem absorber deposited on Cu substrates exhibited high solar selectivity ({alpha}/{epsilon}) of 0.946/0.07 even after heat treatment in air up to 600 C for 2 h. At 625 C, the solar selectivity decreased significantly on Cu substrates (e.g., {alpha}/{epsilon}=0.924/0.30). The tandem absorber on Cu substrates was also stable in air up to 100 h at 400 C with a solar selectivity of 0.919/0.06. Studies on the accelerated aging tests indicated that the activation energy for the degradation of the tandem absorber is of the order of 100 kJ/mol. (author)

Working Group 'Air pollution abatement' of the University of Stuttgart -ALS. Annual report 1990

International Nuclear Information System (INIS)

1991-01-01

Despite considerable efforts for air pollution abatement - examples are here desulphurization and nitrogen removal in power and large combustion plants as well as catalytic converters for automobiles there are still many problems to solve. Many small and medium-size companies still have to reduce production-related pollutant emissions, traffic still is a major source of pollutants. Air pollution abatement in the new Federal states and other Eastern European countries is a particularly urgent task and reductions of CO 2 emissions from energy production processes with fossil fuels are not least a great challenge. Apart from industry, legislation and administration especially science is called upon to find solutions to these problems. The university of Stuttgart takes up the challenge. Numerous institutes - 17 of 8 faculties -united in the working group ''air pollution abatement'' of the university of Stuttgart which carries out in interdisciplinary cooperation research work in the area of air pollution abatement. In this annual report activities of individual member states institutes in the area of air pollution abatement (fields of study, current research projects, cooperations and publications in 1991) as well as joint projects are presented. (orig./KW) [de

Influence of air-particle deposition protocols on the surface topography and adhesion of resin cement to zirconia.

Science.gov (United States)

Sarmento, Hugo R; Campos, Fernanda; Sousa, Rafael S; Machado, Joao P B; Souza, Rodrigo O A; Bottino, Marco A; Ozcan, Mutlu

2014-07-01

This study evaluated the influence of air-particle abrasion protocols on the surface roughness (SR) of zirconia and the shear bond strength (SBS) of dual-polymerized resin cement to this ceramic. Sintered zirconia blocks (n = 115) (Lava, 3M ESPE) were embedded in acrylic resin and polished. The specimens were divided according to the 'particle type' (Al: 110 µm Al2O3; Si: 110 µm SiO2) and 'pressure' factors (2.5 or 3.5 bar) (n = 3 per group): (a) Control (no air-abrasion); (b) Al2.5; (c) Si2.5; (d) Al3.5; (e) Si3.5. SR (Ra) was measured 3-times from each specimen after 20 s of air-abrasion (distance: 10 mm) using a digital optical profilometer. Surface topography was evaluated under SEM analyses. For the SBS test, 'particle type', 'pressure' and 'thermocycling' (TC) factors were considered (n = 10; n = 10 per group): Control (no air-abrasion); Al2.5; Si2.5; Al3.5; Si3.5; ControlTC; Al2.5TC; Si2.5TC; Al3.5TC; Si3.5TC. After silane application, resin cement (Panavia F2.0) was bonded and polymerized. Specimens were thermocycled (6.000 cycles, 5-55°C) and subjected to SBS (1 mm/min). Data were analyzed using ANOVA, Tukey's and Dunnett tests (5%). 'Particle' (p = 0.0001) and 'pressure' (p = 0.0001) factors significantly affected the SR. All protocols significantly increased the SR (Al2.5: 0.45 ± 0.02; Si2.5: 0.39 ± 0.01; Al3.5: 0.80 ± 0.01; Si3.5: 0.64 ± 0.01 µm) compared to the control group (0.16 ± 0.01 µm). For SBS, only 'particle' factor significantly affected the results (p = 0.015). The SiO2 groups presented significantly higher SBS results than Al2O3 (Al2.5: 4.78 ± 1.86; Si2.5: 7.17 ± 2.62; Al3.5: 4.97 ± 3.74; Si3.5: 9.14 ± 4.09 MPa) and the control group (3.67 ± 3.0 MPa). All TC specimens presented spontaneous debondings. SEM analysis showed that Al2O3 created damage in zirconia in the form of grooves, different from those observed with SiO2 groups. Air-abrasion with 110 µm Al2O3 resulted in higher roughness, but air-abrasion protocols with SiO2

Riesgo sanitario de la población vulnerable expuesta al arsénico en la provincia de Buenos Aires, Argentina Health risk for the vulnerable population exposed to arsenic in the province of Buenos Aires, Argentina

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Julio A. Navoni

2012-01-01

Full Text Available OBJETIVO: Analizar la concentración de arsénico en agua recolectada en localidades de la provincia de Buenos Aires, Argentina, y su relación epidemiológica con factores de susceptibilidad y patologías asociadas. MÉTODOS: Se cuantificó la concentración de arsénico en 152 muestras provenientes de 52 localidades de Buenos Aires durante el período 2003-2008 mediante generación de hidruros-espectrofotometría de absorción atómica. Se construyó un índice compuesto de salud (ICS considerando el contenido de arsénico, el porcentaje de hogares con necesidades básicas insatisfechas (NBI y el de viviendas sin acceso al agua de red. A partir del ICS se definieron zonas de riesgo que fueron asociadas con la mortalidad por tumores malignos relacionados con el arsénico. RESULTADOS: Las concentraciones de arsénico se ubicaron en un rango amplio, desde 0,3 hasta 187 µg/L, con una mediana de 40 µg/L. El 82% de las muestras presentaron niveles de arsénico superiores al valor límite aceptable de 10 µg/L, y más de la mitad de ellas provenían de agua de red. La mortalidad promedio (defunciones/100 000 habitantes por tumores en los departamentos estudiados fue mayor en los varones que en las mujeres: vías respiratorias (310 frente a 76, vías urinarias (44 frente a 11 y piel (21 frente a 11, respectivamente. Las regiones de mayor concentración de arsénico y pobreza, junto con la falta de agua de red, presentaron un riesgo relativo incrementado de 2 a 4 veces. CONCLUSIONES: La caracterización realizada a través del índice compuesto de salud sintetizó el riesgo sanitario de la exposición al arsénico de la población con niveles de carencia socioeconómica de una amplia región de la provincia de Buenos Aires.OBJECTIVE: To analyze the concentration of arsenic in water collected in localities of the province of Buenos Aires, Argentina, and the epidemiological relationship of that concentration to factors of susceptibility and associated

Imágenes transitorias. Globalización y modificaciones urbanas en ciudades del norte de México

OpenAIRE

Eloy Méndez Sainz

1996-01-01

Las expectativas mexicanas de inserción en los mercados globales, han sido puestas en las ciudades. Aunque frente a limitaciones de fondo, emerge el mercado de la imagen, uno de los renglones de mayor agresividad competitiva. En el escenario urbano, las interrogantes en torno al qué y cómo vender se anteponen por regla a políticas orientadas al bienestar social. En el ámbito particular de la Frontera Norte, formada por ciudades de crecimiento acelerado con ritmo sostenido a lo largo ...

Plan de negocio agencia de marketing digital

OpenAIRE

Menéndez Díaz, Borja

2015-01-01

Con la realización de este plan de negocio, se tratará de estudiar la viabilidad para la puesta en marcha de una empresa dedicada al marketing digital, especializándose en el sector sanitario y fijándose como clientes potenciales todas aquellas empresas farmacéuticas en el ámbito nacional. La empresa pretende hacer marketing digital orientado al sector farmacéutico siguiendo unos procesos rigurosos y estandarizados con los que el cliente esté acorde en todo momento, manteniendo una actitud...

Subjetividades emergentes en el manual de convivencia de la IED Nicolás Buenaventura y el Colegio Liceo Homérico

OpenAIRE

Gaviria De Lima, Christian Alan; Rojas Cordero, William

2017-01-01

Si bien las instituciones educativas ya sean de carácter oficial o privado poseen la autonomía para construir sus Manuales de Convivencia, los mismos deben tener en cuenta las disposiciones que el Ministerio de Educación Nacional refiere al respecto. Se hace evidente la puesta en escena de Manuales de Convivencia que no responden al contexto que viven los establecimientos, sin embargo, si tienen un efecto sobre la configuración del individuo. Los Manuales de Convivencia transportan un saber, ...

Low cycle fatigue behavior of polycrystalline NiAl at 300 and 1000 K

Science.gov (United States)

Lerch, Bradley A.; Noebe, Ronald D.

1993-01-01

The low cycle fatigue behavior of polycrystalline NiAl was determined at 300 and 1000 K - temperatures below and above the brittle- to-ductile transition temperature (BDTT). Fully reversed, plastic strain-controlled fatigue tests were conducted on two differently fabricated alloy samples: hot isostatically pressed (HIP'ed) prealloyed powder and hot extruded castings. HIP'ed powder (HP) samples were tested only at 1000 K, whereas the more ductile cast-and-extruded (C+E) NiAl samples were tested at both 1000 and 300 K. Plastic strain ranges of 0.06 to 0.2 percent were used. The C+E NiAl cyclically hardened until fracture, reaching stress levels approximately 60 percent greater than the ultimate tensile strength of the alloy. Compared on a strain basis, NiAl had a much longer fatigue life than other B2 ordered compounds in which fracture initiated at processing-related defects. These defects controlled fatigue life at 300 K, with fracture occurring rapidly once a critical stress level was reached. At 1000 K, above the BDTT, both the C+E and HP samples cyclically softened during most of the fatigue tests in air and were insensitive to processing defects. The processing method did not have a major effect on fatigue life; the lives of the HP samples were about a factor of three shorter than the C+E NiAl, but this was attributed to the lower stress response of the C+E material. The C+E NiAl underwent dynamic grain growth, whereas the HP material maintained a constant grain size during testing. In both materials, fatigue life was controlled by intergranular cavitation and creep processes, which led to fatigue crack growth that was primarily intergranular in nature. Final fracture by overload was transgranular in nature. Also, HP samples tested in vacuum had a life three times longer than their counterparts tested in air and, in contrast to those tested in air, hardened continuously over half of the sample life, thereby indicating an environmentally assisted fatigue damage

EMISIONES AL AIRE DE LA COMBUSTION DE LLANTAS USADAS (SPANISH VERSION)

Science.gov (United States)

The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

Effect of the aggregate grading on the concrete air permeability

Directory of Open Access Journals (Sweden)

Argiz, C.

2014-09-01

Full Text Available Great durability problems are being found in concrete structures related to the penetrability of aggressive agents through the concrete (ie. chloride penetration, sulphate attack, carbonation, freezing and thawing, and so on. Air permeability coefficient is used as an effective tool to estimate the potential durability of concrete structures due to its direct relation with the microstructure and the moisture content. This paper discusses the effect of the aggregate grading and water/cement ratio on the air permeability coefficient. An aggregate grading with more sand than coarse aggregates has resulted more beneficial from the point of view of concrete air permeability. This fact can be attributed to a denser skeleton formed by the finer aggregates. With fine aggregates, the higher water/cement ratio, the lower air permeability. However, the contrary was found with coarse aggregates. Overall, a temperature increase from 20 °C to 60 °C during preconditioning led to a Dair increase of 40–80%.Se han encontrado una gran cantidad de problemas de durabilidad de estructuras de hormigón relacionados con la penetración de agentes agresivos externos (es decir, penetración de cloruros, ataque por sulfatos, carbonatación, hielo-deshielo, etc.. El coeficiente de permeabilidad al aire se utiliza como una herramienta eficaz para estimar la durabilidad potencial de las estructuras de hormigón debido a su relación directa con su microestructura y contenido de humedad. Se discute el efecto de la gradación de los áridos y relación agua/cemento en el coeficiente de permeabilidad al aire. Con áridos más finos que gruesos, el resultado es más beneficioso, lo que se atribuye a que la arena forma un esqueleto más denso. Con áridos más finos, al aumentar la relación agua/cemento, disminuye la permeabilidad al aire; pero con áridos más gruesos se ha observado lo contrario. Cuando se pre-acondiciona de 20 °C a 60 °C, se produce un aumento del Dair

Ghazala et al., Afr J Tradit Complement Altern Med. (2016) 13(3):54 ...

African Journals Online (AJOL)

Key words: Toxicity; Profenofos; esterase activity; issues; fish ... environmental matrices; e.g., water, air, soil and organisms (Fang et al., 2014; Salem et al., ... restricted and was banned in many countries such as European Union countries, Asia, etc. ..... behavioral pattern of fingerling common carp (Cyprinus carpio L., 1758).

Effects of air humidity on ionization chamber response

International Nuclear Information System (INIS)

Meger, C.; DeLuca, P.M. Jr.; Pearson, D.W.; Venci, R.

1983-01-01

A study of the effect of air humidity on four different ionization chamber cap materials verified earlier studies (Kristensen and Sundbom, 1981; Mijnheer et al., 1983) and extended our understanding of the problem. We found nylon and A-150 plastic caps swell as they absorb water from the air. This accounts for as much as 2.5% increase in ionization response. Graphite chambers readily absorb and desorb water from the air. This creates a problem in maintaining dry air in a wet graphite chamber. Humid air has a different density and W value than dry air (Niatel, 1969, 1975). This decreases the charge collected in a wet graphite chamber. We observe a decrease in response of approximately 2%, a value greater than can be accounted for by these effects alone. Polyethylene chambers are unaffected by humid air. 4 refs., 9 figs

Contribución al desarrollo sostenible local de los proyectos MDL en el sector de generación eléctrica por biomasa: caso INCAUCA S.A.

Directory of Open Access Journals (Sweden)

Carlos Andrés Vergara Tamayo

2016-01-01

Full Text Available La declaración presentada por la comunidad internacional a mediados del siglo XX frente al reconocimiento del fenómeno del cambio climático, dio origen a propuestas de la comunidad para la creación de mecanismos orientados al control y a la reducción de sus causas. Una de estas propuestas es el Protocolo de Kyoto, el cual tiene por objetivo la reducción de los Gases Efecto Invernadero (GEI causantes del calentamiento global. Dicho protocolo planteó tres iniciativas, pero, tan solo una de ellas involucra la participación de países en vía de desarrollo como es el caso de Colombia; se trata de los Proyectos de Mecanismo de Desarrollo Limpio (MDL. En este sentido, el objetivo de este documento es comprender los aportes en términos del desarrollo sostenible local, a partir de la metodología multicriterio AHP, para el proyecto MDL de cogeneración y sustitución de combustible del Ingenio del Cauca S.A., registrado ante la Convención Marco de las Naciones Unidas para el Cambio Climático (CMNUCC. De este trabajo se concluye que no existe una diferencia importante entre la situación “con proyecto” y la situación “sin proyecto”, en otras palabras, la contribución al desarrollo social del Municipio de Miranda (Cauca, no está determinada por la puesta en marcha del proyecto MDL, sin embargo al analizar de manera global el ranking de las dos alternativas evaluadas es evidente que los actores involucrados prefieren la situación antes del proyecto que con este.

Structure of MeCrAlY + AlSi coatings deposited by Arc-PVD method on CMSX4 single crystal alloy

International Nuclear Information System (INIS)

Swadzba, L.; Hetmanczyk, M.; Mendala, B.; Saunders, S.R.J.

2002-01-01

Investigations of depositing high temperature resistant coatings on the Ni base superalloys by Arc-PVD method using exothermic reaction processes between Ni and Al with NiAl intermetallic formation are presented in the article. By the diffusion heating at 1050 o C in vacuum, NiAl diffusion coating containing 21% at. Al and 50 μm thick were obtained. In the next stage coatings with more complex chemical composition - MeCrAlY were formed. The MeCrAlY coatings were made from two targets. Good correlation between the chemical composition of the targets and a uniform distribution of elements in the coatings was shown. Then the surface was also covered with aluminium by the Arc-PVD method . In the vacuum chamber of the equipment a synthesis reaction between NiCoCrAlY and Al with the formation of NiAl intermetallics of high Co, Cr, Y content was initiated. The final heat treatment of coatings was conducted in vacuum at 1323 K. Strong segregation of yttrium into the oxide scale in the specimens heated in the air was shown. It was possible to form NiAl and intermetallics phase coatings modified by Co, Cr and Y by the Arc-PVD method. The coatings were formed on a single crystal CMSX-4. The structure, morphology and phase composition of coatings was carried out. (author)

Oxidation behaviour of a Ti{sub 2}AlN MAX-phase coating

Energy Technology Data Exchange (ETDEWEB)

Wang Qimin; Kim, Kwangho [National Core Research Center for Hybrid Materials Solution, Pusan National University, Busan 609-735 (Korea, Republic of); Garkas, W; Renteria, A Flores [Chair of Physical Metallurgy and Materials Technology, Technical University of Brandenburg at Cottbus, 03046 Cottbus (Germany); Leyens, C [Institute of Materials Science, Technical University of Dresden, Helmholtzstrasse 7, 01069 Dresden (Germany); Sun Chao, E-mail: qmwang@pusan.ac.kr, E-mail: kwhokim@pusan.ac.kr [Division of Surface Engineering of Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2011-10-29

In this paper, we reported the oxidation behaviour of Ti{sub 2}AlN coatings on a -TiAl substrate. The coatings composed mainly of Ti{sub 2}AlN MAX phase were obtained by magnetron sputtering and subsequent vacuum annealing. Isothermal oxidation tests at 700-900 deg. C were performed in air. The results indicated that the oxidation resistance of the -TiAl alloy can be improved by depositing a Ti{sub 2}AlN layer on the alloy surface, especially at high temperatures. An Al-rich oxide scale formed on the coating surfaces during oxidation. This scale acts as diffusion barrier blocking the ingress of oxidation, and effectively protects the coated alloys from further oxidation attack.

Armaflex in Burj al Arab; Armaflex im Burj al Arab

Energy Technology Data Exchange (ETDEWEB)

Steiner, B.

2003-07-01

This article describes the Burj al Arab in Dubai, the unique seven-star high-rise hotel. The construction of the hotel, that is built on 250 piles driven into the sand of an artificial island in the Persian Gulf, is described. In particular, various special materials used in the building are described, as are the luxurious fittings and furnishings of the hotel. The cooling and air-conditioning installations that are necessary as a result of the desert climate of Dubai are described and the use of 'Armaflex' elastomer insulating material for the insulation of refrigeration machines and cold-water piping is discussed.

Effect of air annealing on the color center in Yb:Y3Al5O12 transparent ceramics with MgO as sintering additive

Science.gov (United States)

Lu, Zhongwen; Lu, Tiecheng; Wei, Nian; Zhang, Wei; Ma, Benyuan; Qi, Jianqi; Guan, Yongbing; Chen, Xingtao; Wu, Huajun; Zhao, Yu

2015-09-01

High quality Yb:Y3Al5O12 (YAG) transparent ceramics were fabricated by vacuum sintering with MgO as sintering aids. The Yb:YAG samples were annealed at 1250-1450 °C for 20 h in air. The experimental results showed that the transparency of Yb:YAG samples declined markedly with the annealing temperatures of 1250-1450 °C. The samples became increasingly orange-yellow in color with the increase of annealing temperature. The potential reasons of discoloration were discussed for the first time. It was attributed to the complex color center [Mg2+F+] formed during the annealing, which was evidenced by optical absorption in the range of 300-500 nm wavelength and the presence of an electron spin resonance (ESR) line at g = 1.9806. The formation mechanism of the complex color center was explained in detail. The complex color center can be eliminated after post-HIP (hot isostatic pressing). And by air annealing and post-HIP, the transmittance of the samples increased from 80.3% to 83.4%.

Microstructure/Oxidation/Microhardness Correlations in Gamma-Based and Tau-Based Al-Ti-Cr Alloys

Science.gov (United States)

Brady, Michael P.; Smialek, J. L.; Humphrey, D. L.

1994-01-01

The relationships between alloy microstructure and air oxidation kinetics and alloy microstructure and microhardness in the Al-Ti-Cr system for exposures at 800 C and 1000 C were investigated. The relevant phases were identified as tau (Ll2), gamma (LIO), r-Al2Ti, TiCrAl (laves), and Cr2AI. Protective alumina formation was associated with tau, Al-rich TiCrAl, and gamma/TiCrAl mixtures. Brittleness was associated with the TiCrAl phase and tau decomposition to A12Ti + Cr2AI. It was concluded that two-phase gamma + TiCrAl alloys offer the greatest potential for oxidation resistance and room temperature ductility in the Al-Ti-Cr system.

AL-QUR’AN AND HUMAN MIND: THE FACTS OF SCIENCE DEVELOPMENT

Directory of Open Access Journals (Sweden)

Prima Aswirna

2015-12-01

Fakta-fakta ilmiah yang diklaim dalam al-Qur'an ada di berbagai wacana, ter­masuk dalam hal ini penciptaan, astronomi, reproduksi manusia, oseanologi, embroyologi, zoologi, dan siklus air. Artikel ini ingin mengeksplorasi tentang keajaiban al-Qur'an dalam pengetahuan ilmiah, terutama dalam ilmu alam. Dengan pendekatan analisis deskriptif, penelitian ini mampu menunjukkan fakta empiris keajaiban al-Qur'an telah ditemukan kebenaran ilmiah dalam ilmu. Artikel ini juga menunjukkan keterbatasan kecerdasan manusia untuk me­mahami semua realitas yang ada di dunia ini. Serta mengajak kembali kepada manusia pentingnya untuk kembali mendialogkan antara al-Qur'an dan ke­cerdas­an dalam mengeksplorasi ilmu pengetahuan.

Air pollution tolerance indices of some plants around Ama industrial ...

African Journals Online (AJOL)

SAM

2014-03-12

Mar 12, 2014 ... Table 1. Air pollution tolerance index (APTI) of some plant species around some industries in Ama, Enugu State, Nigeria. Plant specie. Site .... these receive most impact from the pollution load in the environment. APTI is an inherent quality of plants to encounter air pollution stress (Rai et al., 2013). These.

78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

Science.gov (United States)

2013-02-11

... initial speeds, vehicle manufacturers will need to develop unique or complicated braking systems to comply... [Docket No. NHTSA-2013-0011] RIN 2127-AL11 Federal Motor Vehicle Safety Standards; Air Brake Systems... rule that amended the Federal motor vehicle safety standard for air brake systems by requiring...

AL:PE - Acidification of Mountain Lakes: Palaeolimnology and Ecology. Part 2 - Remote Mountain Lakes as Indicators of Air Pollution and Climate Change

Energy Technology Data Exchange (ETDEWEB)

Wathne, Bente M; Patrick, Simon; Cameron, Nigel [eds.

1997-07-01

AL:PE is a multi-disciplinary and multi-national project coordinated by research groups in London and Oslo. It is funded by the European Commission, The project is described in this report. The project is the first comprehensive study of remote mountain lakes on a European scale. It is concerned with ecosystems in the arctic and alpine regions of Europe that are threatened by acid deposition, toxic air pollutants and climatic change despite their remoteness. The studies are important not only for ecosystems of the lakes, for which they were designed, but for the arctic and alpine regions in general, since the lakes with their sediment records act as environmental sensors. The AL:PE results illustrate two overarching issues: (1) the importance of these remote and sensitive ecosystems as sensors of long-range transported pollutants and as providers of early warning signals for more widespread environmental change; and (2) the importance and urgency of understanding the present and future impact of pollutants, both singly and in combination, on aquatic ecosystems. Currently, acid deposition is considered the most potent threat. In the context of global warming, however, it is a formidable scientific challenge to disentangle the interactions between the effects of changing deposition patterns of acids, nutrients, trace metals and trace organics. The AL:PE programme has begun to address this challenge and its successor EU project, MOLAR, is designed to tackle the issues more more specifically by focusing on in-depth studies of key sites. 97 refs., 192 figs., 100 tabs.

Modificación del diseño de la pulpeadora comercial de frutas para pulpeado de fruto entero de Mauritia flexuosa, (aguaje) y mayor valor agregado a partir de la pulpa deshidratada

OpenAIRE

García Pinchi, Ricardo; Alva Arévalo, Alenguer Gerónimo; Tello Célis, Fernando; Silva Ramos, Luis; Díaz Sangama, Emilio; Pasquel Ruíz, Antonio; Vásquez Jurafo, Doylith Claudia; López Ruiz, Tani Lorena; García García, Ronal Stiwar

2015-01-01

La presente investigación plantea : Modificar el diseño del pulpeador, realizar el montaje y puesta en marcha; realizar pruebas de maduración de aguaje en relación al tiempo y al porcentaje de rendimiento en pulpa con el equipo rediseñado; obtener pulpa deshidratada mediante el secador de lecho fluidizado y el liofilizador, realizar pruebas con esta pulpa deshidratadas en la obtención de néctar en distintos envases La modificación del diseño de la pulpeadora convencional nos permitirá pulp...

La responsabilidad social corporativa en el Perú. Realidad versus discurso

OpenAIRE

León Untiveros, Miguel A.

2010-01-01

En nuestro país, la conciencia de la responsabilidad social corporativa (RSC), al menos a nivel del discurso, ocupa un espacio significativo. Por ello, resulta de suma importancia evaluar su puesta en práctica en atención a su realidad económica y social. Así, en este trabajo presentamos el estado del arte junto con algunas críticas importantes sobre la RSC y su noción más amplia: la sostenibilidad corporativa (partes I al IV). Luego pasamos a contrastar el modelo discursivo con la realidad p...

Karabük İlindeki Hava Kirliliğinin Doğal Gaz Kullanımı İle Değişimi / The Change of Air Pollution in Karabuk with the Usage of Natural Gas

Directory of Open Access Journals (Sweden)

Yusuf CAY

2012-12-01

Full Text Available Fosil kaynaklı yakıtların kullanımı, hava kirliliğine sebebiyet veren en önemli unsurlardan bir tanesidir. Bu yakıtların bilinçsizce kullanılması sonucunda çevre problemlerine özellikle de hava kirliliğine neden olmaktadır. Yapılan bu çalışmada, Karabük ilinin doğalgaz kullanmaya başlamadan önceki ve doğalgaza geçiş ile hava kirlilik parametreleri (SO2 ve PM10 incelenmiştir. Doğal gaz kullanımının hava kalitesine etkisi araştırılmıştır. İlde ısınma ihtiyacını karşılamak için kömür, fuel-oil ve mazot kullanılırken 2010 yılı itibariyle doğal gaza geçilmiştir. Doğal gazın kullanılmaya başlanmasıyla bu yakıtların kullanımı azalmıştır. Çalışmanın sonunda, Hava Kalitesi Değerlendirme ve Yönetimi Yönetmeliğinde (HKDYY belirtilen, SO2 için 250 μg/m3 değerinin doğal gaz kullanımına geçilmeden önce bazı aylarda üzerinde olduğu görülmüş ve doğal gaz kullanılmaya başlanmasından sonraki dönemlerde ise 250 μg/m3 değerinin aşılmadığı görülmüştür. PM10 için yönetmelikte belirtilen 200 μg/m3 değerinin kış sezonunda aşıldığı tespit edilmiştir. 2010 yılında Doğal gaz kullanımına geçiş ile birlikte bu değerde tekrar bir düşüş gözlenmiştir. Doğal gaz kullanım oranı artıkça havadaki SO2 ve PM10 değerlerinde ciddi düşüşler olduğu gözlenmiştir. The Change of Air Pollution in Karabuk with the Usage of Natural Gas The Usage of fossil origin fuels is one of the most important cause of air pollution. The usage of these fuels unconsciously causes environmental problems especially air pollution. In this study air pollution parameters (SO2 ve PM10 were analyzed before and after the usage of natural gas in Karabuk. The effect of usage natural gas on air quality is researched. In this city before 2010 coal, foul-oil and diesel were used to provide heat demanded then it is started using natural gas by 2010.With starting the usage of

Disparities in the Impact of Air Pollution

Science.gov (United States)

... et al. Health, Wealth, and Air Pollution: Advancing Theory and Methods. Environ Health Perspect. 2003; 111: 1861- ... error: function() { console.log("An error occurred while processing XML file."); } }); } } --> ... LUNG HEALTH INFORMATION Lung Disease List Warning Signs of Lung Disease ...

New directions: Air pollution challenges for developing megacities like Delhi

Science.gov (United States)

Kumar, Prashant; Khare, Mukesh; Harrison, Roy M.; Bloss, William J.; Lewis, Alastair C.; Coe, Hugh; Morawska, Lidia

2015-12-01

Most major cities around the world experience periods of elevated air pollution levels, which exceed international health-based air quality standards (Kumar et al., 2013). Although it is a global problem, some of the highest air pollution levels are found in rapidly expanding cities in India and China. The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies. We focus here on Delhi, one of the largest global population centres, which faces particular air pollution challenges, now and in the future.

What is IAQ? [Indoor Air Quality]; Wat is IAQ? [Indoor Air Quality

Energy Technology Data Exchange (ETDEWEB)

Fanger, P.O. [International Centre for Inoor Environment and Energy, Technical University of Denmark, Lyngby (Denmark)

2007-07-15

Indoor air quality (IAQ) is often defined as the extent to which human requirements are met. The air should be fresh and pleasant, not have a negative impact on health, that it not effects productivity. Present ventilation standards and guidelines do not include productivity and only require that the indoor air must be 'acceptable'. With such a modest aim it is not surprising that comprehensive field studies in many countries in buildings in which ventilation standards are met show high percentages of dissatisfied persons and of those suffering from Sick Building Syndrome. Recent studies show that improvement of IAQ by a factor of 2-7 compared with existing standards increases office productivity and school learning significantly, while decreasing the risk of allergic symptoms and asthma in homes. To make indoor air acceptable, even for the most sensitive persons, an improvement of 1-2 orders of magnitude may be required. The paper will discuss the development of new methods that can provide such substantial improvements of IAQ while maintaining or even decreasing ventilation end energy usage. [Dutch] In ruimtes die bestemd zijn voor menselijke bezetting wordt de binnenluchtkwaliteit (indoor Air Quality - IAQ) vaak gedefinieerd als de mate waarin aan menselijke behoeften wordt voldaan. Maar welke behoeften hebben mensen van de binnenlucht? Het is wenselijk dat de lucht wordt ervaren als zuiver en aangenaam. Dit betekent dat de lucht geen negatieve invloed mag hebben op de gezondheid en dat de lucht het werken moet stimuleren. De binnenlucht zou de productiviteit van werknemers en de schoolprestaties van kinderen moeten verhogen. In de huidige normen en richtlijnen voor ventilatie worden deze laatste twee aspecten niet meegenomen, er wordt uitgegaan van de bescheiden eis dat de binnenluchtkwaliteit 'acceptabel' dient te zijn. Dit houdt in dat de meest gevoelige groep personen (doorgaans 20%) de lucht als onacceptabel zal beoordelen en dat de

Synthesis of CuAlO2 nanofibrous mats by electrospinning

International Nuclear Information System (INIS)

Zhao Shizhen; Li Miaoyu; Liu Xiaomin; Han Gaoyi

2009-01-01

Electrospinning as a versatile method for preparation of nanofibers has been used to fabricate the polyvinylalcohol nanofibers containing equal molar of aluminum nitrate and copper acetate. After pretreated at 400 deg. C, the composite fibrous mats were annealed at 1100 deg. C in air for 5 h and then the delafossite-structured p-type CuAlO 2 ceramics fibrous mats were obtained. The obtained CuAlO 2 ceramics fibrous mats were characterized by scanning electrical microscope, X-ray diffraction and diffuse reflectance spectroscopy. The direct energy gap of the prepared CuAlO 2 ceramics fibrous mats was measured to be about 3.38 eV. The CuAlO 2 behaved like semiconductors and the thermally activated energy was about 0.25 eV.

EN EL AIRE / In the air

Directory of Open Access Journals (Sweden)

Andrés López Fernández

2011-11-01

Full Text Available RESUMEN En el aire es un viaje a la primera mitad del siglo XX que nos tratará de acercar la frescura y oportunidad de las calles corredor y los jardines en la ciudad vertical. Se inicia en 1909 en Nueva York, con la publicación por la revista Life de La Torre del Globo, se acerca al Inmueble-Villas y al Plan Obus para Argel de Le Corbusier, y finaliza en 1952 con el proyecto para el conjunto residencial de Golden Lane en Londres de A. y P. Smithson. Fragmentos para la ciudad vertical que se construía sobre papel, tras el espejo, paralela en el tiempo, pero muy distinta a la ciudad real, con el objetivo entre otros de integrar arquitectura y naturaleza. Esas propuestas siguen teniendo hoy un gran valor, en un panorama en que el espacio público ligado a la vivienda colectiva, prácticamente ha desaparecido, y el esfuerzo que se demanda al arquitecto se centra, en tejer a modo de encaje de bolillos, una fachada que envuelva un programa de vivienda, funcional y espacialmente obsoleto. SUMMARY In the air, is a journey to the first half of the twentieth century that will try to bring us to the freshness and opportunity of the corridor streets and gardens in the vertical city. It begins in 1909 in New York, with the publication in Life magazine of the Globe Tower, it approaches the Immeubles-Villas and Plan Obus for Algiers by Le Corbusier, and ends in 1952 with the project for the Golden Lane Estate residential complex in London, by A. and P. Smithson. Fragments for the vertical city that was constructed on paper, behind the mirror, parallel in time, but was very different from the real city, with the aim, inter alia, of integrating architecture and nature. These proposals continue to have great value today, in a scenario where the public space linked to the collective home has virtually disappeared, and the effort that is demanded of the architect focuses on weaving a facade like bobbin lace around a functionally and spatially obsolete housing

Degradation of 2DEG transport properties in GaN-capped AlGaN/GaN heterostructures at 600 °C in oxidizing and inert environments

Science.gov (United States)

Hou, Minmin; Jain, Sambhav R.; So, Hongyun; Heuser, Thomas A.; Xu, Xiaoqing; Suria, Ateeq J.; Senesky, Debbie G.

2017-11-01

In this paper, the electron mobility and sheet density of the two-dimensional electron gas (2DEG) in both air and argon environments at 600 °C were measured intermittently over a 5 h duration using unpassivated and Al2O3-passivated AlGaN/GaN (with 3 nm GaN cap) van der Pauw test structures. The unpassivated AlGaN/GaN heterostructures annealed in air showed the smallest decrease (˜8%) in 2DEG electron mobility while Al2O3-passivated samples annealed in argon displayed the largest drop (˜70%) based on the Hall measurements. Photoluminescence and atomic force microscopy showed that minimal strain relaxation and surface roughness changes have occurred in the unpassivated samples annealed in air, while those with Al2O3 passivation annealed in argon showed significant microstructural degradations. This suggests that cracks developed in the samples annealed in air were healed by oxidation reactions. To further confirm this, Auger electron spectroscopy was conducted on the unpassivated samples after the anneal in air and results showed that extra surface oxides have been generated, which could act as a dislocation pinning layer to suppress the strain relaxation in AlGaN. On the other hand, similar 2DEG sheet densities were observed in passivated and unpassivated AlGaN/GaN samples at the end of the 5-h anneal in air or argon due to the combined impact of strain relaxation and changes in the ionized electronic states. The results support the use of unpassivated GaN-capped AlGaN/GaN heterostructures as the material platform for high-temperature electronics and sensors used in oxidizing environmental conditions.

Interaction of Al with O{sub 2} exposed Mo{sub 2}BC

Energy Technology Data Exchange (ETDEWEB)

Bolvardi, Hamid; Music, Denis, E-mail: music@mch.rwth-aachen.de; Schneider, Jochen M.

2015-03-30

Highlights: • Al adheres to many surfaces. • Solid–solid interactions challenging for real (oxidized) surfaces. • Dissociative O{sub 2} adsorption on Mo{sub 2}BC(0 4 0). • Al nonamer is disrupted on oxidized Mo{sub 2}BC(0 4 0). • Adhesion of a residual Al on the native oxide. - Abstract: A Mo{sub 2}BC(0 4 0) surface was exposed to O{sub 2}. The gas interaction was investigated using ab initio molecular dynamics and X-ray photoelectron spectroscopy (XPS) of air exposed surfaces. The calculations suggest that the most dominating physical mechanism is dissociative O{sub 2} adsorption whereby Mo−O, O−Mo−O and Mo{sub 2}−C−O bond formation is observed. To validate these results, Mo{sub 2}BC thin films were synthesized utilizing high power pulsed magnetron sputtering and air exposed surfaces were probed by XPS. MoO{sub 2} and MoO{sub 3} bond formation is observed and is consistent with here obtained ab initio data. Additionally, the interfacial interactions of O{sub 2} exposed Mo{sub 2}BC(0 4 0) surface with an Al nonamer is studied with ab initio molecular dynamics to describe on the atomic scale the interaction between this surface and Al to mimic the interface present during cold forming processes of Al based alloys. The Al nonamer was disrupted and Al forms chemical bonds with oxygen contained in the O{sub 2} exposed Mo{sub 2}BC(0 4 0) surface. Based on the comparison of here calculated adsorption energy with literature data, Al−Al bonds are shown to be significantly weaker than the Al−O bonds formed across the interface. Hence, Al−Al bond rupture is expected for a mechanically loaded interface. Therefore the adhesion of a residual Al on the native oxide layer is predicted. This is consistent with experimental observations. The data presented here may also be relevant for other oxygen containing surfaces in a contact with Al or Al based alloys for example during forming operations.

Application of mesoporous Al-MCM-48 material to the conversion of lignin.

Science.gov (United States)

Lee, Hyung Won; Lee, In-Gu; Park, Sung Hoon; Jeon, Jong-Ki; Suh, Dong Jin; Jung, Jinho; Park, Young-Kwon

2014-04-01

Al-MCM-48 was applied to the catalytic pyrolysis of lignin for the first time. The pyrolysis reaction and in-situ product were analyzed by pyrolysis gas chromatography/mass spectrometry. The main products of the non-catalytic pyrolysis of lignin were phenols. The use of Al-MCM-48 increased the production of light phenols considerably. The yields of high-value-added compounds, such as hydrocarbons and aromatics, were also increased by catalytic upgrading. Al-MCM-48 is believed to promote cracking, aromatization and deoxygenation, such as decarbonylation. On the other hand, Si-MCM-48, which has no acid sites, showed lower deoxygenation efficiency than Al-MCM-48. Al-MCM-48 could be regenerated by calcining in air.

Air pollution tolerance indices of some plants around Ama industrial ...

African Journals Online (AJOL)

SAM

2014-03-12

Mar 12, 2014 ... relative water content and leaf extract pH to evaluate the susceptibility of some ... plants and its level is a direct measure of leaf damage by pollution (Bayon et al., ... plants so as to help mitigate the effects of air pollution globally since air ... Ngwo, Udi Local Government Area (L.G.A.), Enugu. State, Nigeria.

EL AVANCE DE LA FRONTERA AGRÍCOLA EN EL ÁREA ADYACENTE AL SISTEMA SIERRAS DE LA VENTANA (BUENOS AIRES, ARGENTINA

Directory of Open Access Journals (Sweden)

Mario Fabián Marini

2008-01-01

Full Text Available Se determinó el incremento de la superficie agrícola en el área adyacente al Sistema Sierras de la Ventana (Buenos Aires, Argentina. Para ello se emplearon imágenes satelitales Landsat 5 TM de diversas fechas, realizándose una comparación entre la campaña agrícola 1998/ 1999 con respecto a la 2006/ 2007. El análisis llevado a cabo demuestra que existe un incremento en la superficie dedicada a la actividad agrícola que asciende a 55572 has, lo que representa en un aumento del 27,97 %. El mismo es originado principalmente por la propagación de los cultivos de verano, principalmente de la soja, de significativa expansión en la República Argentina en las últimas dos décadas.

La educación puesta a prueba en un espacio de reclusión

Directory of Open Access Journals (Sweden)

Gilles Chantraine

2013-04-01

Full Text Available Recién llegados al paisaje carcelario francés, los establecimientos penitenciarios para menores (EPM son fruto de la voluntad de convertir los espacios de reclusión destinados a jóvenes de entre 13 y 18 años en espacios propiamente “educativos”, al objeto de dar respuesta a la falta de continuidad socioeducativa de los menores presos de los quartiers mineurs ubicados en las prisiones de adultos. Basada en una investigación monográfica realizada en dos EPM que mezcla observaciones directas de la vida cotidiana de la reclusión con entrevistas semiestructuradas hechas al conjunto de actores del EPM.Esta contribución está basada en una investigación monográfica hecha en dos EPM, que mezcla observaciones directas de la vida cotidiana de la reclusión con entrevistas semidirectivas realizadas al conjunto de actores del EPM; su objetivo es analizar la forma adoptada por las prácticas educativas en estos establecimientos y su entrelazamiento con el orden penitenciario. Una vez recordados algunos elementos de contexto relativos a las recientes transformaciones de la justicia de menores en Francia, propondremos una mirada simétrica de las prácticas de los educadores de la PJJ (Protección Judicial de la Juventud y de los vigilantes penitenciarios.Este análisis simétrico nos llevará a demostrar que, aun poniendo de manifiesto una apertura relativa de la institución carcelaria, el EPM sigue marcado por una supremacía de las lógicas securitarias sobre las lógicas educativas, que dibuja una articulación original entre ambas lógicas: en el EPM ya no se trata únicamente de constreñir los cuerpos de los presos a someterse al orden penitenciario, sino también de una labor de movilización de las subjetividades reclusas mediante un trabajo “educativo” de persuasión sobre la pertinencia del orden penitenciario.

The Cost of Crop Damage Caused by Ozone Air Pollution From Motor Vehicles

OpenAIRE

Delucchi, Mark A.; Murphy, James; Kim, Jin; McCubbin, Donald R.

1996-01-01

The detrimental effects of ambient ozone on crops, even at relatively low concentrations, are well-established (Thompson et al., 1976; Heck and Brandt, 1977; Heck et al., 1982; Environmental Protection Agency, 1984; California Air Resources Board, 1987; Olszyk et al., 1988a, 1988b; Heagle et al., 1986; McCool et al., 1986, Ashmore, 1991). Ozone enters plant leaves through the stomatal openings in the leaf surface and then produces byproducts that reduce the efficiency of photosynthesis (CARB...

Variación geográfica y ecológica en los parámetros reproductivos de las aves insectívoras forestales del paleártico occidental

Directory of Open Access Journals (Sweden)

Sanz, J. J.

2003-12-01

Full Text Available The present study shows variation in some breeding parameters (laying date, clutch size in relation to geographical coordinates (latitude, longitude, habitat, elevation and habitat type in insectivorous and hole-nesting passerine of European woodlands. The Great Tit (Parus major was used as a model species. Laying date, at the population level, was not affected by habitat type, and did not show any relationship with longitude and elevation. Laying date showed a significant quadratic relationship with latitude, with the earliest values in central Europe. On the other hand, clutch size at the population level significantly differed among habitat type (large clutches being laid in deciduous forests, showed a positive and negative relationships with longitude and elevation, respectively. Mean clutch size showed a quadratic relationship with latitude, with the highest values at about 55 to 60ºN. In the present study, the main hypotheses proposed to explain these patterns found on the breeding parameters of passerines in the Western Palaearctic are discussed.

En este trabajo se pretende mostrar como ciertos parámetros reproductores (fecha de puesta, tamaño de puesta varían geográficamente (latitud, longitud, altitud, tipo de hábitat en las especies de aves nidícolas e insectívoras. Para ello, se utiliza como especie modelo al Carbonero Común (Parus major. La fecha de puesta poblacional no difiere entre hábitats, no muestra relación con la longitud y se incrementa con la altitud. La fecha de puesta poblacional muestra una relación cuadrática con la latitud, con los valores más tempranos en latitudes medias. Por otro lado, el tamaño de puesta poblacional difiere entre los hábitats estudiados, siendo mayor en los bosques caducifolios, muestra una relación positiva con la longitud y una relación negativa con la altitud. Además, el tamaño de puesta poblacional muestra una relación cuadrática con la latitud, con

Creep behavior of Ti3Al-Nb intermetallic alloys

International Nuclear Information System (INIS)

Yu, T.H.; Yue, W.J.; Koo, C.H.

1997-01-01

It is well known that Ti 3 Al-Nb alloys are potential materials for aerospace applications. The creep property is an important consideration when materials are used at high temperature. In this article, the effect of microstructure of Ti-25Al-10Nb alloy on the creep property was investigated, and the creep property of Ti-25Al-10Nb alloy modified by small addition of silicon 0.2 at.% or carbon 0.1 at.% was observed. The alloy with the addition of molybdenum to replace part of niobium 2 at.% was also studied. The experimental results show that the furnace-cooled Ti-25Al-10Nb alloy has superior creep resistance to the air-cooled Ti-25Al-10Nb alloy at 200 MPa, but exhibits poor creep resistance at 250 MPa or above. Small addition of silicon to the Ti-25Al-10Nb alloy may increase creep resistance. Small addition of carbon to the Ti-25Al-10Nb alloy may reduce creep resistance but raise rupture strain. Molybdenum is the most effective alloying element to increase creep resistance for the Ti-25Al-10Nb alloy. The creep mechanism of Ti-25Al-10Nb alloy is governed by dislocation climb. (orig.)

Current linearity and operation stability in Al2O3-gate AlGaN/GaN MOS high electron mobility transistors

Science.gov (United States)

Nishiguchi, Kenya; Kaneki, Syota; Ozaki, Shiro; Hashizume, Tamotsu

2017-10-01

To investigate current linearity and operation stability of metal-oxide-semiconductor (MOS) AlGaN/GaN high electron mobility transistors (HEMTs), we have fabricated and characterized the Al2O3-gate MOS-HEMTs without and with a bias annealing in air at 300 °C. Compared with the as-fabricated (unannealed) MOS HEMTs, the bias-annealed devices showed improved linearity of I D-V G curves even in the forward bias regime, resulting in increased maximum drain current. Lower subthreshold slope was also observed after bias annealing. From the precise capacitance-voltage analysis on a MOS diode fabricated on the AlGaN/GaN heterostructure, it was found that the bias annealing effectively reduced the state density at the Al2O3/AlGaN interface. This led to efficient modulation of the AlGaN surface potential close to the conduction band edge, resulting in good gate control of two-dimensional electron gas density even at forward bias. In addition, the bias-annealed MOS HEMT showed small threshold voltage shift after applying forward bias stress and stable operation even at high temperatures.

Estudi i modificació d’un difusor de ventilador tipus Dyson Air Multiplier

OpenAIRE

Soler Calderé, Roger

2014-01-01

[CATALÀ] El Dyson Air Multiplier és un tipus de ventilador de sobre taula sense aspes, que produeix un corrent d’aire continu. Per crear aquest corrent, l’aire és accelerat a través d’una obertura anular creant un cabal d’aire a alta velocitat. Aquest flux d’aire passa per una superfície aerodinàmica que canalitza la seva direcció i genera zones de baixa pressió. Aquest canvi de pressió aspira l’aire de l’entorn cap al corrent d’aire, augmentant el cabal mobilitzat. Per a realitzar el seu est...

Simulation evaluation of NIST air-kerma rate calibration standard for electronic brachytherapy.

Science.gov (United States)

Hiatt, Jessica R; Rivard, Mark J; Hughes, H Grady

2016-03-01

Dosimetry for the model S700 50 kV electronic brachytherapy (eBT) source (Xoft, Inc., a subsidiary of iCAD, San Jose, CA) was simulated using Monte Carlo (MC) methods by Rivard et al. ["Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent x-ray source: An electronic brachytherapy source," Med. Phys. 33, 4020-4032 (2006)] and recently by Hiatt et al. ["A revised dosimetric characterization of the model S700 electronic brachytherapy source containing an anode-centering plastic insert and other components not included in the 2006 model," Med. Phys. 42, 2764-2776 (2015)] with improved geometric characterization. While these studies examined the dose distribution in water, there have not previously been reports of the eBT source calibration methods beyond that recently reported by Seltzer et al. ["New national air-kerma standard for low-energy electronic brachytherapy sources," J. Res. Natl. Inst. Stand. Technol. 119, 554-574 (2014)]. Therefore, the motivation for the current study was to provide an independent determination of air-kerma rate at 50 cm in air K̇air(d=50 cm) using MC methods for the model S700 eBT source. Using CAD information provided by the vendor and disassembled sources, an MC model was created for the S700 eBT source. Simulations were run using the mcnp6 radiation transport code for the NIST Lamperti air ionization chamber according to specifications by Boutillon et al. ["Comparison of exposure standards in the 10-50 kV x-ray region," Metrologia 5, 1-11 (1969)], in air without the Lamperti chamber, and in vacuum without the Lamperti chamber. K̇air(d=50 cm) was determined using the *F4 tally with NIST values for the mass energy-absorption coefficients for air. Photon spectra were evaluated over 2 π azimuthal sampling for polar angles of 0° ≤ θ ≤ 180° every 1°. Volume averaging was averted through tight radial binning. Photon energy spectra were determined over all polar angles in both air and vacuum using

La gran vida al aire libre PSA (:30) (The Great Outdoors)

Centers for Disease Control (CDC) Podcasts

2016-05-31

Un hombre y una mujer se están alistando para irse a una caminata. La mujer le recuerda al hombre que se proteja del sol.  Created: 5/31/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 5/31/2016.

Violencia laboral en urgencias extrahospitalarias: una revisión sistemática y líneas de intervención psicológica

Directory of Open Access Journals (Sweden)

Mónica Bernaldo-de-Quirós

2014-01-01

en servicios de emergencia, b programas de prevención dirigidos al entrenamiento en habilidades de comunicación con los pacientes y/o acompañantes, la identificación de situaciones de riesgo y la puesta en marcha de estrategias de afrontamiento adecuadas y medidas de seguridad, y c la atención psicológica de los profesionales que ya han sufrido alguna agresión.

Laboratory Investigations of Ni-Al Coatings Exposed to Conditions Simulating Biomass Firing

DEFF Research Database (Denmark)

Wu, Duoli; Okoro, Sunday Chukwudi; Dahl, Kristian Vinter

2016-01-01

Fireside corrosion is a key problem when using biomass fuels in power plants. A possible solution is to apply corrosion resistant coatings. The present paper studies the corrosion and interdiffusion behaviour of a Ni-Al diffusion coating on austenitic stainless steel (TP347H). Ni-Al coatings were...... prepared by electrolytic deposition of nickel followed by pack aluminizing performed at 650˚C. A uniform and dense Ni-Al coating with an outer layer of Ni2Al3 and an inner Ni layer was formed. Samples were exposed to 560°C for 168h in an atmosphere simulating biomass combustion. This resulted in localized...... corrosion attack. Interdiffusion was studied by isothermal heat treatment in static air at 650˚C or 700˚C for up to 3000h. The Ni2Al3 gradually transformed into NiAl and Ni3Al during the interdiffusion process. Porosity developed at the interface between the Ni-Al coating and the Ni layer and expanded...

Vidas laborales encontradas : trayectorias, posicionamientos y disputas generacionales de jóvenes frente al mundo del trabajo. Un barrio en la zona sur del Área Metropolitana de Buenos Aires

OpenAIRE

Rengifo Gutiérrez, Juan Roberto

2015-01-01

Este estudio considera el ‘problema del trabajo’ desde una perspectiva antropológica. A partir de una postura procesual, analiza los cambios, las tensiones y las convergencias que, a lo la rgo de una misma generación, determinados jóvenes de sectores populares del partido de Lanús (Provincia de Buenos Aires) mantuvieron con relación al trabajo. Se sostiene que el proceso generacional de estos actores estuvo relacionado tanto con los contextos y ti...

Interdiffusion behavior of Al-rich oxidation resistant coatings on ferritic-martensitic alloys

Energy Technology Data Exchange (ETDEWEB)

Velraj, S.; Zhang, Y.; Hawkins, E.W. [Department of Mechanical Engineering, Tennessee Technological University, Cookeville, TN 38505-0001 (United States); Pint, B.A. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6156 (United States)

2012-10-15

Interdiffusion of thin Al-rich coatings synthesized by chemical vapor deposition (CVD) and pack cementation on 9Cr ferritic-martensitic alloys was investigated in the temperature range of 650-700 C. The compositional changes after long-term exposures in laboratory air and air + 10 vol% H{sub 2}O were examined experimentally. Interdiffusion was modeled by a modified coating oxidation and substrate interdiffusion model (COSIM) program. The modification enabled the program to directly input the concentration profiles of the as-deposited coating determined by electron probe microanalysis (EPMA). Reasonable agreement was achieved between the simulated and experimental Al profiles after exposures. The model was also applied to predict coating lifetime at 650-700 C based on a minimum Al content (C{sub b}) required at the coating surface to re-form protective oxide scale. In addition to a C{sub b} value established from the failure of a thin CVD coating at 700 C, values reported for slurry aluminide coatings were also included in lifetime predictions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

RELACIÓN COSTE-BENEFICIO DE LAS POLÍTICAS SOBRE CONSUMO DE TABACO EN EL LUGAR DE TRABAJO

Directory of Open Access Journals (Sweden)

Tamara Raaijmakers

2003-01-01

Full Text Available Este trabajo revisa los motivos que llevan a las empresas a establecer una política sobre control del tabaquismo, los beneficios económicos para la sociedad que se derivan de su adopción, y sus costes, detallados por países en la Unión Europea. Se revisa también la literatura sobre los costes de la aplicación de una política sobre tabaquismo en el ámbito laboral. El principal objetivo de las políticas sobre tabaquismo en el lugar de trabajo es la protección de los empleados del aire contaminado por el humo de tabaco (ACHT. Otros motivos son la reducción de costes; la mejora de la imagen; y la disminución de absentismo, accidentes laborales, conflictos y costes adicionales debidos al tabaco. La protección frente al ACHT no supone mayores costes para la empresa, y se refieren ventajas económicas con su puesta en práctica. Los beneficios sobrepasan con creces las inversiones, en particular a largo plazo, y parecen mayores cuando se establece una prohibición total de fumar en el lugar de trabajo en vez de áreas para fumadores.

Relación coste-beneficio de las políticas sobre consumo de tabaco en el lugar de trabajo

Directory of Open Access Journals (Sweden)

Raaijmakers Tamara

2003-01-01

Full Text Available Este trabajo revisa los motivos que llevan a las empresas a establecer una política sobre control del tabaquismo, los beneficios económicos para la sociedad que se derivan de su adopción, y sus costes, detallados por países en la Unión Europea. Se revisa también la literatura sobre los costes de la aplicación de una política sobre tabaquismo en el ámbito laboral. El principal objetivo de las políticas sobre tabaquismo en el lugar de trabajo es la protección de los empleados del aire contaminado por el humo de tabaco (ACHT. Otros motivos son la reducción de costes; la mejora de la imagen; y la disminución de absentismo, accidentes laborales, conflictos y costes adicionales debidos al tabaco. La protección frente al ACHT no supone mayores costes para la empresa, y se refieren ventajas económicas con su puesta en práctica. Los beneficios sobrepasan con creces las inversiones, en particular a largo plazo, y parecen mayores cuando se establece una prohibición total de fumar en el lugar de trabajo en vez de áreas para fumadores.

Metalorganic vapor phase epitaxy of AlN on sapphire with low etch pit density

Science.gov (United States)

Koleske, D. D.; Figiel, J. J.; Alliman, D. L.; Gunning, B. P.; Kempisty, J. M.; Creighton, J. R.; Mishima, A.; Ikenaga, K.

2017-06-01

Using metalorganic vapor phase epitaxy, methods were developed to achieve AlN films on sapphire with low etch pit density (EPD). Key to this achievement was using the same AlN growth recipe and only varying the pre-growth conditioning of the quartz-ware. After AlN growth, the quartz-ware was removed from the growth chamber and either exposed to room air or moved into the N2 purged glove box and exposed to H2O vapor. After the quartz-ware was exposed to room air or H2O, the AlN film growth was found to be more reproducible, resulting in films with (0002) and (10-12) x-ray diffraction (XRD) rocking curve linewidths of 200 and 500 arc sec, respectively, and EPDs < 100 cm-2. The EPD was found to correlate with (0002) linewidths, suggesting that the etch pits are associated with open core screw dislocations similar to GaN films. Once reproducible AlN conditions were established using the H2O pre-treatment, it was found that even small doses of trimethylaluminum (TMAl)/NH3 on the quartz-ware surfaces generated AlN films with higher EPDs. The presence of these residual TMAl/NH3-derived coatings in metalorganic vapor phase epitaxy (MOVPE) systems and their impact on the sapphire surface during heating might explain why reproducible growth of AlN on sapphire is difficult.

El Habario : un yacimiento musteriense al aire libre en los Picos de Europa cántabros

Directory of Open Access Journals (Sweden)

Javier Baena Preysler

1999-01-01

Full Text Available En el presente trabajo se presentan los resultados del análisis industrial del yacimiento de El Habario (Pendes, Cantabria, primer yacimiento paleolítico cántabro al aire libre excavado en un ambiente de alta montaña. La explotación sobre cantos de cuarcita implica la captación directa de los recursos lítlcos de altura, muy localizados en el entorno. Se describen las características Industriales del conjunto, sus peculiaridades técnicas (con una cadena operativa específica, muy homogénea y bien representada y la funcionalidad supuesta para el mismo (taller. Tdo ello sugiere la existencia de estrategias complejas de aprovechamiento del medio. Aunque por el momento no ha sido posible obtener dataciones absolutas, dada las características de la muestra, el análisis interno de la industria permite el conjunto en momentos del Paleolítico Medio. Así mismo se insiste en la riqueza arqueológica de la comarca de La Liébana, que cuenta hasta el momento con una importante representación en yacimientos paleolíticos y ofrecerá en los próximos años, sin duda, resultados muy prometedores.The present paper outilnes the results of the industry analysis of El Habario (Pendes, Cantabria, first open palaeolithlc open air site, placed at a high altitude, studied in this región. The explotation of quarzite pebbles Implies the direct captation of llthic resources in a mountalnous área, a particular procedure In this case. The industry characterlstlcs are descrlbed, Its technlcal peculiarities (with a speclfic operative secuence, very homogeneous and well represented, as well as the assumed funtionallty of the site (worksite. All this implies the presence of a complex purposefulness in the captation. Allthough up to now it has been impossible the absoluto dating, given the characterlstlcs of the sample, the Internal analysis of the industry permlts US to assign the findings to the Middle Paleolithic period. in this line, we enfatize the

Developing of a New Atmospheric Ionizing Radiation (AIR) Model

Science.gov (United States)

Clem, John M.; deAngelis, Giovanni; Goldhagen, Paul; Wilson, John W.

2003-01-01

As a result of the research leading to the 1998 AIR workshop and the subsequent analysis, the neutron issues posed by Foelsche et al. and further analyzed by Hajnal have been adequately resolved. We are now engaged in developing a new atmospheric ionizing radiation (AIR) model for use in epidemiological studies and air transportation safety assessment. A team was formed to examine a promising code using the basic FLUKA software but with modifications to allow multiple charged ion breakup effects. A limited dataset of the ER-2 measurements and other cosmic ray data will be used to evaluate the use of this code.

Modernización del sistema de aire de alta presión de las corbetas misileras de la armada del Ecuador

OpenAIRE

Espinoza Estrella, Bryan; Orces, Eduardo

2009-01-01

El estudio se lo hace al sistema de aire de alta presión en las corbetas misileras de la Armada del Ecuador. Este sistema de aire trabaja con presiones elevadas de 206 bar, el cual sirve para suministrar aire comprimido al sistema de armamento y a los sistemas contraincendios: Por razón del excesivo tiempo que tardaba el sistema en presurizarse cuando se requería usarlo, se optó en el año 95 por suministrar aire directamente del compresor a las diferentes unidades de servicio, evitando ac...

Air-Sea Interactions in the Marginal Ice Zone

Science.gov (United States)

2016-03-31

elementascience.org Air-sea interactions in the marginal ice zoneAir-Sea interactions in the Marginal Ice Zone Seth Zippel1* • Jim Thomson1 1Applied...Bidlot, 2013; Collins -III et al., 2015). Spectral wave directions and spread are given in Figure 5, where the difference in wave and wind direction...359219a0. Chalikov DV, Belevich MY. 1993. One-dimensional theory of the wave boundary layer. Bound-Lay Meteor 63: 65–96. Collins -III CO, Rogers WE

Characterization of Nd{sub 2}AlO{sub 3}N and Sm{sub 2}AlO{sub 3}N oxynitrides synthesized by carbothermal reduction and nitridation

Energy Technology Data Exchange (ETDEWEB)

Chevire, Francois, E-mail: francois.chevire@univ-rennes1.fr [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , Equipe Verres et Ceramiques, Groupe Materiaux Azotes et Ceramiques, Universite de Rennes 1, 35042 Rennes Cedex (France); Pallu, Arthur; Ray, Erwan; Tessier, Franck [UMR CNRS 6226 ' Sciences Chimiques de Rennes' , Equipe Verres et Ceramiques, Groupe Materiaux Azotes et Ceramiques, Universite de Rennes 1, 35042 Rennes Cedex (France)

2011-05-12

Research highlights: > Carbothermal reduction and nitridation leads to rare earth aluminum oxynitride starting from oxide mixture. > Absorption shifts towards visible in Nd{sub 2}AlO{sub 3}N (orange) and Sm{sub 2}AlO{sub 3}N (yellow). > Oxynitrides are stable up to 600 deg. C in air. > The so-called 'intermediate phase' phenomenon is evidenced in Sm{sub 2}AlO{sub 3}N. - Abstract: The Nd{sub 2}AlO{sub 3}N and Sm{sub 2}AlO{sub 3}N oxynitrides with the K{sub 2}NiF{sub 4}-type structure have been prepared from oxide mixture at 1250 deg. C using the carbothermal reduction and nitridation route (CRN). Optimization of the process is discussed to prevent surface oxidation of the oxynitrides during the synthesis. The absorption of Nd{sub 2}AlO{sub 3}N and Sm{sub 2}AlO{sub 3}N, orange and yellow respectively, has been characterized by diffuse reflectance as well as their thermal stability versus oxidation by thermogravimetric analyses.

Development of weldable, corrosion-resistant iron-aluminide (FeAl) alloys

Energy Technology Data Exchange (ETDEWEB)

Maziasz, P.J.; Goodwin, G.M.; Wang, X.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

1997-04-01

A boron-microalloyed FeAl alloy (Fe-36Al-0.2Mo-0.05Zr-0.13C, at.%, with 100-400 appm B) with improved weldability and mechanical properties was developed in FY 1994. A new scale-up and industry technology development phase for this work began in FY 1995, pursuing two parallel paths. One path was developing monolithic FeAl component and application technology, and the other was developing coating/cladding technology for alloy steels, stainless steels and other Fe-Cr-Ni alloys. In FY 1995, it was found that cast FeAl alloys had good strength at 700-750{degrees}C, and some (2.5%) ductility in air at room-temperature. Hot-extruded FeAl with refined grain size was found to have ductility and to also have good impact-toughness at room-temperature. Further, it was discovered that powder-metallurgy (P/M) FeAl, consolidated by direct hot-extrusion at 950-1000{degrees}C to have an ultra fine-grained microstructure, had the highest ductility, strength and impact-toughness ever seen in such intermetallic alloys.

Synthesis of new metal-matrix Al-Al2O3-graphene composite materials

Science.gov (United States)

Elshina, L. A.; Muradymov, R. V.; Kvashnichev, A. G.; Vichuzhanin, D. I.; Molchanova, N. G.; Pankratov, A. A.

2017-08-01

The mechanism of formation of ceramic microparticles (alumina) and graphene in a molten aluminum matrix is studied as a function of the morphology and type of precursor particles, the temperature, and the gas atmosphere. The influence of the composition of an aluminum composite material (as a function of the concentration and size of reinforcing particles) on its mechanical and corrosion properties, melting temperature, and thermal conductivity is investigated. Hybrid metallic Al-Al2O3-graphene composite materials with up to 10 wt % alumina microparticles and 0.2 wt % graphene films, which are uniformly distributed over the metal volume and are fully wetted with aluminum, are synthesized during the chemical interaction of a salt solution containing yttria and boron carbide with molten aluminum in air. Simultaneous introduction of alumina and graphene into an aluminum matrix makes it possible to produce hybrid metallic composite materials having a unique combination of the following properties: their thermal conductivity is higher than that of aluminum, their hardness and strength are increased by two times, their relative elongation during tension is increased threefold, and their corrosion resistance is higher than that of initial aluminum by a factor of 2.5-4. We are the first to synthesize an in situ hybrid Al-Al2O3-graphene composite material having a unique combination of some characteristics. This material can be recommended as a promising material for a wide circle of electrical applications, including ultrathin wires, and as a structural material for the aerospace industry, the car industry, and the shipbuilding industry.

Narración de un taller de resolución de problemas aritméticos con niños de 4 años

OpenAIRE

Molina, Elisa

2012-01-01

Narración de una sesión de resolución de problemas aritméticos con niñas y niños de 4 y 5. El taller se inicia en la lectura de un cuento en que se basa el enunciado del problema. Después, pasamos al trabajo individual, en que los niños inventan estrategias de modelización, empleando materiales manipulativos. La puesta en común de soluciones y estrategias, compleja a estas edades, constituye la etapa final del taller. Mostramos cómo este tipo de actividad matemática, adecuada al desarrollo de...

Matronas y cambio social en la segunda mitad del siglo XX. De mujeres y partos

OpenAIRE

Alemany Anchel, María José

2014-01-01

Esta investigación profundiza en el análisis de los cambios que se produjeron en la asistencia al parto en la segunda mitad del siglo XX en nuestro país, como consecuencia de las transformaciones políticas, culturales, económicas y sociales. Hemos avanzado en el conocimiento de lo que significó la puesta en marcha de las grandes unidades hospitalarias y en qué medida se transformó la atención al parto de un acto íntimo que se realizaba en el propio domicilio de la parturienta a un acto médico...

Metodologías de desarrollo de proyectos informáticos en entornos web

OpenAIRE

Graña Salgado, Rafael

2011-01-01

El presente TFC tiene dos objetivos principales: 1. Determinar el grado de adaptación de las metodologías ágiles al desarrollo de proyectos web puesta en contexto con la adaptación de las metodologías clásicas a este mismo entorno. 2. Realizar una clasificación de las metodologías de desarrollo de software según el grado de adaptación a los proyectos web. Aquest TFC té dos objectius principals: 1. Pretén determinar el grau d'adaptació de les metodologies àgils al desenvolupament de project...

Plan de negocios Colsisredes 3000

OpenAIRE

2012-01-01

Al analizar los resultados proyectados por el estudio de mercado realizado al sector hotelero y la presencia de las BPO en la ciudad de Bogotá, para la puesta en marcha de la empresa de consultoría COLSISREDES 3000, en la prestación de servicios de consultoría en tecnologías de la información (TI) y servicios contables, se puede deducir que el 63 % de los hoteles encuestados no cuentan con un servicio de BPO, que el 13% de la muestra si les interesa este tipo de servicios y que...

La cultura y el arte del románico: una propuesta didáctica en la programación de 2º de ESO

OpenAIRE

Viñas Rico, Angélica

2017-01-01

El presente trabajo consiste en la realización de una programación didáctica para la asignatura de Historia, correspondiente al curso de 2º de Educación Secundaria Obligatoria.1 Se trata, por tanto, de un instrumento de planificación, desarrollo y evaluación para la puesta en práctica del proceso de enseñanza-aprendizaje, adaptado, lógicamente, al contexto y a las características propias del centro educativo correspondiente. Por otra parte, es importante mencionar que una programación didácti...

Signal compression in radar using FPGA

OpenAIRE

Enrique Escamilla Hemández; Víctor Kravchenko; Volodymyr Ponomaryov; Gonzalo Duchen Sánchez; David Hernández Sánchez

2010-01-01

El presente artículo muestra la puesta en práctica de hardware para realizar el procesamiento en tiempo real de la señal de radar usando una técnica simple, rápida basada en arquitectura de FPGA (Field Programmable Gate Array). El proceso incluye diversos procedimientos de enventanado durante la compresión del pulso del radar de apertura sintética (SAR). El proceso de compresión de la señal de radar se hace con un filtro acoplado. que aplica funciones clásicas y nuevas de enventanado, donde n...

El reto del salario diferido en las pymes españolas

OpenAIRE

Gallego Losada, Rocío

2014-01-01

Tradicionalmente el trabajador de la pequeña y mediana empresa española ha sido el gran olvidado de la llamada previsión social complementaria. Las dificultades que una Pyme encuentra en su camino para la puesta en marcha de un sistema que complemente la pensión pública de sus empleados son muchas, y representan, en definitiva, un alto muro al que la gran mayoría de ellas se niega a asomarse. Dificultades intrínsecas al propio carácter de una Pyme, como es el hecho de la gran facilidad co...

Diagnósticos de enfermería al alta hospitalaria en personas con Síndrome Coronario Agudo

Directory of Open Access Journals (Sweden)

Clara Inés Padilla García

2017-04-01

Full Text Available Introducción: Enfermería juega un rol fundamental en las diferentes etapas de la atención de las personas con síndrome coronario agudo, entre ellas el egreso hospitalario. Brindar cuidado acorde a las necesidades propias de estas personas, requiere de la identificación de los principales diagnósticos de enfermería. Objetivo: Determinar la prevalencia de diagnósticos de Enfermería de las personas con síndrome coronario agudo al momento del alta hospitalaria. Metodología: Estudio de corte transversal en 196 personas hospitalizadas por el evento de interés, se utilizó instrumento de valoración focalizada que evaluaba las características definitorias de los diagnósticos de enfermería: ansiedad, afrontamiento ineficaz, disposición para mejorar la religiosidad, disposición para mejorar los conocimientos, intolerancia a la actividad; los cuales fueron identificados como prioritarios según la literatura científica y por consenso de expertos. Para determinar la prevalencia de los diagnósticos se realizó análisis de definición y características definitorias. Resultados: Se evidenció como principal problema de la población de estudio los conocimientos deficientes, seguido de la intolerancia a la actividad y la ansiedad. De igual forma se logró identificar diagnósticos positivos como la disposición para mejorar los conocimientos y la religiosidad. Conclusiones: El presente trabajo nos permitió identificar necesidades reales y reconocer factores protectores al momento del alta hospitalaria en personas que han vivido un evento coronario agudo, lo cual constituye un punto de partida para el diseño de planes de cuidado y la puesta en marcha de intervenciones que conduzcan a mejorar la situación de salud de este grupo de personas.

Perlongher: sexualidad y saber. Búsqueda ensayística y emergencia intelectual

Directory of Open Access Journals (Sweden)

Javier Gasparri

2013-12-01

Full Text Available El presente artículo se centra en la obra del argentino Néstor Perlongher (1949 – 1992 para intentar rastrear e interrogar un pensamiento sobre la sexualidad, sin descuidar las implicancias literarias del mismo, y en el marco de conjeturas críticas en torno a su singular ejercicio intelectual como así también el recurso al ensayo como forma de articulación conceptual. En esta dirección, la experiencia-límite de Perlongher permite vislumbrar (e hipotetizar consecuencias y proyecciones literarias y políticas, afi rmando así una ética. Se tratará, entonces, de una búsqueda esencialmente escrituraria del saber (en el marco de los saberes actuales a Perlongher, sobre todo las líneas posestructuralistas, y asimismo con la atención puesta en el activismo de disidencia sexual pero que también compromete y se conjuga con la puesta del cuerpo en su afirmación vital.

La borderización del sujeto

Directory of Open Access Journals (Sweden)

Flora Singer

Full Text Available Se analizan en este trabajo ciertas producciones de relaciones de objeto propias a la clínica border-line, pero también a las adicciones y a ciertas situaciones de duelo. De tipo narcisístico, éstas están connotadas desde una doble valencia vivo-muerto, amparadordestructor, y diseñan una figura constituída por un yo que no puede sustentar un conflicto intra-psíquico, una puesta afuera por obra de la proyección – puesta afuera que constituye una desposesión de una parte de sí mismo intolerable –, y la producción de una relación de objeto significativa, que sustituye un trabajo de representación. La “borderización” implicada en esta figura permite, como paradigma, mantener la diversidad de los cuadros clínicos unidos por esta figura común, en forma diferente y complementaria al abordaje nosográfico del border-line.

Nonequilibrium synthesis of Nb-Al alloys by laser processing

International Nuclear Information System (INIS)

Tewari, S.K.; Mazumder, J.

1993-01-01

The technique of laser surface modification provides a unique means of synthesizing novel nonequilibrium materials in near net shape. Claddings of several NbAl 3 alloys with Ti, B and Hf as a ternary alloy addition were prepared using a CW CO 2 laser. Isothermal oxidation behavior of the clads were examined in air. Oxidation tests at 800, 1,200 and 1,400 C. Alternating layers of alumina and NbAlO 4 were not observed in any of the samples as reported in literature for conventionally processed NbAl 3 oxidized under similar conditions. The parabolic rate constants for all the alloys, except 0 B, were comparable to that for isothermal oxidation of β-NiAl, at 1,200 and 1,400 C in 0.1 atm oxygen, which is a known alumina former. Ternary alloying additions for improved oxidation resistance at 1,400 C accompanied with improved ductility were identified

Comparative Investigations on the Stress Corrosion Behavior of α -Al Bronze and α Brass in Sodium Nitrite

International Nuclear Information System (INIS)

Ashour, E.A.

1995-01-01

The stress corrosion behavior of α- Aluminum bronze (copper [Cu] -7% Al) (UNS C 61400) has been investigated as compared to α- brass under slow strain in sodium nitrite solutions under open - circuit and different anodic potentials. While α- brass was quite susceptible to SCC, α- Al bronze was found to be resistant to SCC. The ratios of time to failure in solution to that in air and of maximum stress in solution to that in air decreased sharply with increase of anodic potential for α-brass but remained virtually constant for α- Al bronze. The mode of failure was predominantly ductile for α- Al bronze under various conditions. The stress corrosion cracking of α - brass has been shown to be promoted by relatively concentrated Na N O 2 and high anodic potentials. Previous explanations for the change of the mode of failure from intergranular at open circuit potential (OCP) to transgranular cracking under anodic potential were confirmed. The bronzes resistance to SCC was attributed to the presence of Al 2 O 3 on the alloy surface. 10 Figs

CsPbBr3 QD/AlOx Inorganic Nanocomposites with Exceptional Stability in Water, Light, and Heat.

Science.gov (United States)

Loiudice, Anna; Saris, Seryio; Oveisi, Emad; Alexander, Duncan T L; Buonsanti, Raffaella

2017-08-28

Herein, the assembly of CsPbBr 3 QD/AlO x inorganic nanocomposites, by using atomic layer deposition (ALD) for the growth of the amorphous alumina matrix (AlO x ), is described as a novel protection scheme for such QDs. The nucleation and growth of AlO x on the QD surface was thoroughly investigated by miscellaneous techniques, which highlighted the importance of the interaction between the ALD precursors and the QD surface to uniformly coat the QDs while preserving the optoelectronic properties. These nanocomposites show exceptional stability towards exposure to air (for at least 45 days), irradiation under simulated solar spectrum conditions (for at least 8 h), and heat (up to 200 °C in air), and finally upon immersion in water. This method was extended to the assembly of CsPbBr x I 3-x QD/AlO x and CsPbI 3 QD/AlO x nanocomposites, which were more stable than the pristine QD films. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Panorama de las Academias frente al Siglo XXI

Directory of Open Access Journals (Sweden)

Zoilo Cuellar Montoya

1996-12-01

nombramiento, en ese importante lugar de la salubridad pública, de una persona sin experiencia en esos temas. Las consecuencias de esta decisión no se hicieron esperar y hoy son muy grandes los conflictos existentes en los programas de salud del pueblo colombiano.

Este hecho, por lo menos en Colombia, marca claramente la posición de los estamentos oficiales y políticos frente al médico y a sus posibilidades como administrador en salud. Más tarde, otro economista, que estuvo casi dos años al mando del Ministerio mencionado, contra viento y marea, engañando con su agilidad verbal a quienes ya al final de su período intentaron intervenir, cohonestado por el silencio cómplice del médico y, porque no decirlo, el de nuestra Academia, logró la puesta en marcha de una nueva ley de seguridad social con una filosofía sana, pero totalmente economicista, y en cuyo desarrollo nunca se tuvo en cuenta al médico: ley que busca el cubrimiento universal en salud del pueblo colombiano, loable sin lugar a dudas, pero impracticable por fallas conceptuales básicas, económicas, operacionales y profesionales (desconocimiento del recurso humano en salud...

Washable antimicrobial polyester/aluminum air filter with a high capture efficiency and low pressure drop.

Science.gov (United States)

Choi, Dong Yun; Heo, Ki Joon; Kang, Juhee; An, Eun Jeong; Jung, Soo-Ho; Lee, Byung Uk; Lee, Hye Moon; Jung, Jae Hee

2018-06-05

Here, we introduce a reusable bifunctional polyester/aluminum (PET/Al) air filter for the high efficiency simultaneous capture and inactivation of airborne microorganisms. Both bacteria of Escherichia coli and Staphylococcus epidermidis were collected on the PET/Al filter with a high efficiency rate (∼99.99%) via the electrostatic interactions between the charged bacteria and fibers without sacrificing pressure drop. The PET/Al filter experienced a pressure drop approximately 10 times lower per thickness compared with a commercial high-efficiency particulate air filter. As the Al nanograins grew on the fibers, the antimicrobial activity against airborne E. coli and S. epidermidis improved to ∼94.8% and ∼96.9%, respectively, due to the reinforced hydrophobicity and surface roughness of the filter. Moreover, the capture and antimicrobial performances were stably maintained during a cyclic washing test of the PET/Al filter, indicative of its reusability. The PET/Al filter shows great potential for use in energy-efficient bioaerosol control systems suitable for indoor environments. Copyright © 2018 Elsevier B.V. All rights reserved.

Una mirada estudiantil calificadora al profesorado de la Universidad Técnica de Machala

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MSc. Nasly Paquita Tinoco Cuenca

2018-05-01

Full Text Available Este estudio se realizó en la carrera de Educación Básica de la Universidad Técnica de Machala con el propósito de identificar los criterios de los estudiantes en relación a la labor docente desplegada por sus profesores y socializar estas creencias. La estrategia metodológica asumida responde al paradigma cuanti-cualitativo, se basa en los métodos: fenomenológico, revisión bibliográfica, analítico-sintético y estadístico; la información se obtuvo a través de las técnicas de entrevista en profundidad y el cuestionario, aplicadas a los 138 matriculados en esta carrera que permitieron concluir que en general los profesores se caracterizan por la organización de sus clases, la paciencia mostrada durante la explicación del contenido, la claridad de sus explicaciones y respuestas a las interrogantes de los educandos, la atención a las dificultades del estudiante, la utilidad de las tareas didácticas que asigna y el dominio de los contenidos. No obstante, existen limitaciones en cuanto a las relaciones con los dicentes, el dominio de las tecnologías, y el conocimiento y la puesta en práctica de metodologías de enseñanza que permitan lograr mayor calidad en la formación de los futuros egresados, lo que se refleja en el criterio de estos, quienes manifiestan la posibilidad de recomendarlos a otros condiscípulos.

Converting hcp Mg-Al-Zn alloy into bcc Mg-Li-Al-Zn alloy by electrolytic deposition and diffusion of reduced lithium atoms in a molten salt electrolyte LiCl-KCl

International Nuclear Information System (INIS)

Lin, M.C.; Tsai, C.Y.; Uan, J.Y.

2007-01-01

A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500 deg. C. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12 wt.% Li and only 0.264 wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix

En el arca de Arreola, carne y palabra se buscan (sobre su Bestiario de 1958

Directory of Open Access Journals (Sweden)

François Gramusset

2015-01-01

Full Text Available Este artículo es un análisis del compendio “zoológico” presente en Bestiario de Juan José Arreola. El acercamiento al universo imaginario de Arreola se aborda en primer lugar a través de la puesta en diálogo del Bestiario con el Physiologos, texto embrionario de los bestiarios de la tradición occidental y en segundo lugar a través de un análisis de texto. En esencia se pretende subrayar el modo en que los animales del bestiario (a través de su lexicalización se encarnan en representaciones imaginarias, vinculadas éstas con los tiempos primordiales. Para tal fin estudiamos tres paradigmas clasificatorios de la carne animal que denominamos: tierra, aire, agua. Dicha clasificación pretende dar cuenta de la significación espiritual de la palabra en el libro de Arreola y a la vez reflejar la manera en que los animales del bestiario simbolizan la carne humana, hecha posible a través del lenguaje poético.

Discursos e intervenciones en torno al espacio público. Experiencias en Viena y Buenos Aires a principios de siglo XXI.

Directory of Open Access Journals (Sweden)

Eva Schwab

2014-12-01

Full Text Available En esta contribución indagamos en torno a políticas públicas para el espacio público que se desarrollan en el seno de los gobiernos de Viena y Buenos Aires. Específicamente, pretendemos: a describir los discursos vigentes sobre el espacio público, focalizándonos en relación a la noción de integración, y b analizar diversas intervenciones estatales en el espacio público orientadas -al menos explícitamente- a generar ciudades más inclusivas e integradas. A partir de un análisis sustentado fundamentalmente en fuentes secundarias, entendemos que a pesar de discursos en apariencia similares, se debería considerar que Viena y Buenos Aires inscriben su historia y devenir en contextos territoriales disímiles. Sin embargo, el proceso de globalización implica -entre otras cuestiones- una homogenización de los discursos a la vez que una relativa subestimación de los condicionantes locales. Estimar los mismos resulta indispensable para entender las implicaciones de esos discursos en la implementación de políticas públicas con efecto directo en el espacio público y sus usos. Una evaluación de las diferencias de las condiciones locales enriquece el análisis en torno a las intervenciones en el espacio público por parte de los gobiernos de ambas ciudades, permitiéndonos comprender la ambigüedad de las nociones y el riesgo de pérdida/cuestionamiento de derechos que implica esa ambigüedad -especialmente para los sectores sociales más vulnerables de la sociedad-.

El hombre con su contradicción: del desflorador avergonzado al "hombre color mujer". // The man with his contradiction: from ashamed deflowered to "woman-colored man".

Directory of Open Access Journals (Sweden)

Fredy Ricardo Moreno Chía.

2009-12-01

Full Text Available The basis of this article is the idea that “the masculine” has an internal contradiction. This is supported by some freudian references, and brought out by Jacques Lacan’s formulations, particularly in his sexuation theory and his innovations on the borromean knot. We wonder how these statements explain the internal contradiction of masculinity, and we look for a possible answer in Lacan’s assertion that there is a “woman-colored man”, whose context corresponds to his theory of the sinthome. // El presente trabajo parte de la idea según la cual “lo masculino” posee una contradicción interna. Esta idea que es sustentada en algunas referencias freudianas es puesta a la luz de las formulaciones de Jacques Lacan, en particular su teoría de la sexuación y sus desarrollos en torno al nudo borromeo. Nos preguntamos cómo estas formulaciones dan cuenta de esa contradicción interna de la masculinidad, e intentamos una posible respuesta en la afirmación de Lacan, según la cual hay “hombre color mujer” y cuyo contexto corresponde a su teoría acerca del sinthome.

Ambient air quality monitoring at Universiti Tunku Abdul Rahman (UTAR) Kampar campus

Science.gov (United States)

Jie, Lim Jun; Xinxin, Guo; Ke, Wang

2017-04-01

Air Pollutant includes any substance in solid, liquid or gaseous form present in the atmosphere in concentrations which may tend to be injurious to all living creatures, property and environment. In this study, automatic continuous monitoring station was used to monitor concentration of carbon monoxide (CO), non-methane hydrocarbon (NMHC), and carbon dioxide (CO2) in the ambient air of Kampar Campus, Universiti Tunku Abdul Rahman. High-volume air sampler was also used to monitor the concentration of PM2.5 and the collected PM2.5 was further analysed for the heavy metal concentration such as Zinc (Zn), Cadmium (Cd), Copper (Cu), Arsenic (As), Aluminium (Al), and Lead (Pb) in PM2.5 using inductively coupled plasma-mass spectrometer (ICP-MS). The overall ambient air quality in the campus area is consider unhealthy as the non-methane hydrocarbon (NMHC) and carbon dioxide (CO2) average concentration obtained were far exceeding the recommended limit concentration set by United States Environmental Protection Agency (USEPA). Meteorological data was found that it does not show much relationship with the air quality data in this study. The concentration of Zn and Al were found the dominant heavy metal in the ambient air. The enrichment factor analysis also shows that the heavy metals contained in PM2.5 mainly origin from the natural source except for the Zn which it is highly contaminated by human activities.

Akad On Air: Radio als Schulfach. - Ein Projektbericht aus Salzburg.

Directory of Open Access Journals (Sweden)

Mirjam Winter

2010-03-01

Full Text Available Spätestens seit „Beverly Hills 90210“, der beliebten US-Teenie-Serie der 90er Jahre, kennt man es: das Schulradio. Ein eigenes Radiostudio kann sich keine Schule in Österreich leisten. Trotzdem ist es in Salzburg gelungen, ein Schulradio auf die Beine zu stellen – als eigenes Schulfach, in dem die Schülerinnen und Schüler praktisch mit dem Medium arbeiten und es für ihre Zwecke nutzen lernen. Der folgende Projektbericht skizziert, wie Medienpädagogik und die Vermittlung von Medienkompetenz an Schulen aussehen können.

Model Research On Synthesis Of Al2O3-C Layers By MOCVD

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Sawka A.

2015-06-01

Full Text Available These are model studies whose aim is to obtain information that would allow development of new technology for synthesizing monolayers of Al2O3-C with adjusted microstructure on cemented carbides. The Al2O3-C layer will constitute an intermediate layer on which the outer layer of Al2O3 without carbon is synthesized. The purpose of the intermediate layer is to block the cobalt diffusion to the synthesized outer layer of Al2O3 and to stop the diffusion of air oxygen to the substrate during the synthesis of the outer layer. This layer should be thin, continuous, dense and uniform in thickness.

In-situ Electrodeposition of Highly Active Silver Catalyst on Carbon Fiber Papers as Binder Free Cathodes for Aluminum-air Battery.

Science.gov (United States)

Hong, Qingshui; Lu, Huimin

2017-06-13

Carbon fiber papers supported Ag catalysts (Ag/CFP) with different coverage of electro-active site are prepared by electrochemical deposition and used as binder free cathodes in primary aluminum-air (Al-air) battery. Scanning Electron Microscopy and X-ray Diffraction studies are carried out to characterize the as-prepared Ag/CFP air cathodes. Oxygen reduction reaction (ORR) activities on these air cathodes in alkaline solutions are systematic studied. A newly designed aluminum-air cell is used to further determine the cathodes performance under real operation condition and during the test, the Ag/CFP electrodes show outstanding catalytic activity for ORR in concentrated alkaline electrolyte, and no obvious activity degradation is observed after long-time discharge. The electrochemical test results display the dependence of coverage of the electro-active Ag on the catalytic performance of the air cathodes. The resulting primary Al-air battery made from the best-performing cathode shows an impressive discharge peak power density, outperforming that of using commercial nano-manganese catalyst air electrodes.

Project of energy saving in compressed air; Proyecto de ahorro de energia en aire comprimido

Energy Technology Data Exchange (ETDEWEB)

Automatizacion, Productividad y Calidad S.A. de C.V. Puebla, (Mexico)

2005-07-01

The objective of this project is to reduce the operation costs by means of the energy saving through the use of the compressed air system. For this purpose the solenoid valves controlled per time and the manually acted valves of sphere must be replaced by pneumatic purges that remove from the system the condensed humidity without discharging air and which act automatically when the water reaches the level of unloading in its deposit. The pressure level is the reduction of the operation rank of pressure in the compressors, satisfying the operation requirements of the process equipment. [Spanish] El objetivo de este proyecto es reducir el costo de operacion mediante el ahorro de energia en la utilizacion del sistema de aire comprimido. Para ello se tienen que remplazar las valvulas solenoides controladas por tiempo y valvulas de esfera actuadas manualmente por purgas neumaticas que remueven del sistema la humedad condensada sin descargar aire y que actuan en forma automatica al alcanzar el agua el nivel de descarga en su deposito. El nivel de presion es la reduccion del rango de operacion de presion de los compresores, satisfaciendo los requerimientos de operacion de los equipos de proceso.

AlGaN Channel Transistors for Power Management and Distribution

Science.gov (United States)

VanHove, James M.

1996-01-01

Contained within is the Final report of a Phase 1 SBIR program to develop AlGaN channel junction field effect transistors (JFET). The report summarizes our work to design, deposit, and fabricate JFETS using molecular beam epitaxy growth AlGaN. Nitride growth is described using a RF atomic nitrogen plasma source. Processing steps needed to fabricate the device such as ohmic source-drain contacts, reactive ion etching, gate formation, and air bride fabrication are documented. SEM photographs of fabricated power FETS are shown. Recommendations are made to continue the effort in a Phase 2 Program.

El discurso como ejercicio de la territorialidad. Disputas y discursos territoriales en la costa marítima de Buenos Aires (Argentina

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Facundo Martín Hernández

2016-01-01

Full Text Available El presente artículo aborda la tensión entre actores suscitada en la dialéctica de territorialización en determinados espacios marítimos-costeros bonaerenses (Argentina desde una perspectiva geográfica y discursiva. Se parte del supuesto de que la creación de territorios no siempre implica conflictividad, aunque siempre que existe disputa sobre el carácter de un determinado espacio se están ejerciendo formas antagónicas o divergentes de territorialidad. En los casos donde se producen pugnas por el territorio se activa un tipo discursivo que denominamos territorial, por lo tanto, el primer objetivo del trabajo es proponer una definición del mismo. Como caso de estudio se seleccionaron las disputas territoriales gestadas en torno al desarrollo de infraestructura turística en la costa bonaerense, respondiendo al modelo más simple de enfrentamiento: la oposición de un sujeto colectivo a un particular proceso de territorialización. Una cualidad común de los casos seleccionados es la asimetría en las relaciones de fuerza, lo que lleva al actor que se opone a tal o cual intervención en el territorio a desarrollar su estrategia de territorialidad mediante acciones innovadoras y creativas, entre ellas, la puesta en práctica de discursos territoriales. El segundo objetivo es el análisis de estos discursos elaborados por aquellos actores que protagonizan disputas en escenarios turísticos de la costa bonaerense. Para los objetivos propuestos se efectuó un análisis interpretativo de los discursos territoriales en tres movimientos regionales con proyección social, capacidad organizativa y continuidad, extrayendo el material de las diversas formas de comunicación y difusión con el que cuentan.

Asymptotic analysis of methane-hydrogen-air mixtures

NARCIS (Netherlands)

Hermanns, R.T.E.; Bastiaans, R.J.M.; Goey, de L.P.H.

2005-01-01

In this paper an asymptotic analysis of de Goey et al.concerning premixed stoichiometric methane-hydrogen-air flames is analyzed in depth. The analysis is performed with up to 50 mole percent of hydrogen in the fuel, at gas inlet temperatures ranging from 300 K to 650 K and pressures from 1 to 15

The Accidental Change Agent: Using the Air Force in the Process of Social Change

Science.gov (United States)

2013-04-01

to get out of the military. Additionally, if the pregnant woman was unmarried , she received a punitive discharge and little support, if any, for...7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) School of Advanced Air And Space Studies,,Air University,,Maxwell Air Force Base,AL 8... PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT

Properties of copper matrix reinforced with nano- and micro-sized Al2O3 particles

International Nuclear Information System (INIS)

Rajkovic, Viseslava; Bozic, Dusan; Jovanovic, Milan T.

2008-01-01

The mixture of electrolytic copper powder with 5 wt.% of commercial Al 2 O 3 powder (average particle size: 15 and 0.75 μm, respectively) and the inert gas atomized prealloyed copper powder (average particle size: 30 μm) containing 2.5 wt.% aluminum were separately milled in air up to 20 h in the planetary ball mill. During milling aluminum in the prealloyed copper powders was oxidized in situ by internal oxidation with oxygen from the air forming very fine nano-sized Al 2 O 3 particles. The internal oxidation of 2.5 wt.% aluminum generated 4.7 wt.% of Al 2 O 3 in the copper matrix. Powders and compacts were characterized by light and scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffraction analysis. Microhardness and electrical conductivity were also included in measurements. The microhardness of Cu-2.5 wt.% Al compacts was 3.6 times higher than that of compacts processed from electrolytic copper powder. This increase in microhardness is a consequence of a fine dispersion of Al 2 O 3 particles and refined grain structure. The average values of electrical conductivity of compacts processed from Cu-5 wt.% Al 2 O 3 and Cu-2.5 wt.% Al powders previously milled for 20 h and were 88% and 70% IACS, respectively, which is a rather significant increase if compared with values of 60% and 23% IACS of compacts processed from as-received and non-milled powders. The microhardness of 20-h milled compacts decreases with the heat treatment at 800 deg. C. Due to the effect of nano-sized Al 2 O 3 particles Cu-2.5 wt.% Al compacts show lower decrease in microhardness. The results are discussed in terms of the effect of Al 2 O 3 particle size and fine grain structure on the reinforcing of the copper matrix

Influencia de la estación y de las especies Phragmites australis y Schoenoplectus californicus en la eliminación de materia orgánica y nutrientes contenidos en aguas servidas durante la operación de puesta en marcha de humedales construidos de flujo horizontal subsuperficial

Directory of Open Access Journals (Sweden)

Karen Rojas

2013-01-01

Full Text Available Las plantas de tratamiento de aguas servidas basadas en humedales construidos de flujo horizontal subsuperficial (HSS, logran su etapa de madurez después de dos años de operación. La eficiencia de operación de los sistemas depende de la estacionalidad, tipo de plantas y periodo de madurez del sistema. El objetivo de este trabajo es evaluar la influencia de la estación y de las especies Phragmites australis y Schoenoplectus californicus, en la eficiencia de depuración en materia orgánica y nutrientes de unidades de HSS, durante la etapa operativa de puesta en marcha. Con esta finalidad, se implementaron cuatro unidades de HSS bajo condiciones climáticas mediterráneas australes. Dos unidades fueron plantadas con Phragmites australis y las otras dos, con Schoenoplectus californicus. En este trabajo se presentan los resultados de la etapa de puesta en marcha, que cubre los primeros 193 días de operación. Se evaluó la influencia de la especie de planta y la estación (invierno y primavera, en la eficiencia de depuración de materia orgánica (Demanda Biológica de Oxígeno, DBO5, y Demanda Química de Oxígeno, DQO y nutrientes (nitrógeno (N-NH4+, N-NO3- y NT y fósforo (P-PO4-3 y PT. Las unidades de HSS plantadas con Phragmites australis mostraron mejor adaptación temprana que las unidades de HSS plantadas con Schoenoplectus californicus. Sin embargo, las eficiencias de eliminación fueron similares en todas las unidades. Estacionalmente, se pudo evidenciar una diferencia de eliminación para DQO (invierno: 18 a 30%, primavera: 45 a 55% y NT (invierno: 25 a 65%, primavera: 25 a 35%.

Ambient Air Ammonia (NH3) Concentration in Two Solid Waste ...

African Journals Online (AJOL)

MBI

2017-05-22

May 22, 2017 ... and thereby adds significantly to the external costs related to air pollution in ... condensation nuclei and indirectly increase cloud life time (Myhre et al., 2009). ..... Cost Effective Strategy for Reducing. Atmospheric Particulate ...

Al nanogrid electrode for ultraviolet detectors.

Science.gov (United States)

Ding, G; Deng, J; Zhou, L; Gan, Q; Hwang, J C M; Dierolf, V; Bartoli, F J; Mazuir, C; Schoenfeld, W V

2011-09-15

Optical properties of Al nanogrids of different pitches and gaps were investigated both theoretically and experimentally. Three-dimensional finite-difference time-domain simulation predicted that surface plasmons at the air/Al interface would enhance ultraviolet transmission through the subwavelength gaps of the nanogrid, making it an effective electrode on GaN-based photodetectors to compensate for the lack of transparent electrode and high p-type doping. The predicted transmission enhancement was verified by confocal scanning optical microscopy performed at 365 nm. The quality of the nanogrids fabricated by electron-beam lithography was verified by near-field scanning optical microscopy and scanning electron microscopy. Based on the results, the pitch and gap of the nanogrids can be optimized for the best trade-off between electrical conductivity and optical transmission at different wavelengths. Based on different cutoff wavelengths, the nanogrids can also double as a filter to render photodetectors solar-blind.

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 ...

Elemental analysis of dust trapped in air conditioner filters for the assessment of Lahore city's air quality

International Nuclear Information System (INIS)

Siddique, N.

2011-01-01

A study was undertaken to assess the air quality of Lahore by the elemental analysis of air conditioner (AC) filter dust samples collected from 15 different commercial sites. Samples were prepared using the Leeds Public Analyst Method and were analyzed using instrumental neutron activation analysis (INAA) for up to 31 elements. The elements Al, As, Ba, Ce, Co, Cr, Cs, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sc, Sm, Sn, Ta, Th, Yb and Zn were detected in all 15 samples whereas the remaining elements have been detected in fewer samples; i.e. Mg, Sb and Tb were detected in 14 samples, Br and V in ten samples, U in nine samples and Ca and Ti in eight samples only. Al, Ca, Fe, K, Mg and Na were determined in all samples at percentage levels. The concentrations of most elements were found to lie around the mean values for the 15 samples studied and were not orders of magnitude different. However the concentrations of Ca, Mg, Sn and Zn were found to be more variable and were found to be dependant on activities such as construction, fruit and vegetable handling, tin plating and transport, respectively. (author)

Lope de Vega y el poder monárquico: una puesta al día

Directory of Open Access Journals (Sweden)

Marcella Trambaioli

2012-04-01

Full Text Available The essay tries to outline the ‘state-of-the-art’ about the relationship between Lope deVega and the contemporary monarchic power. After some early studies merely concerning the politicaltheory present inside the texts, the scholars have started to analyze his historical theater in relation withhis construction of the Spanish Empire mythology, even if only recently some of them have realized thatthis glorification of both the Austrias and the Spanish nobles gets on with Lope’s self-promotionstrategies, in order to obtain an official post at court. On the contrary, some scholars, mainlyAnglosaxon, have tried to interpret his works in a critical and satyrical perspective, without consideringthe necessary contextualization of his theater. The reception theory may help studying this controversialmatter, only if it tries to match in the right way both the historical and cultural context of the authorand the cultural background of the contemporary audience.

24 h stability of thick multilayer silicene in air

International Nuclear Information System (INIS)

De Padova, Paola; Ottaviani, Carlo; Quaresima, Claudio; Generosi, Amanda; Paci, Barbara; Le Lay, Guy; Olivieri, Bruno; Imperatori, Patrizia; Salomon, Eric; Angot, Thierry; Quagliano, Lucia; Romano, Claudia; Vona, Alessandro; Muniz-Miranda, Maurizio

2014-01-01

Thick epitaxial multilayer silicene films with a √3 × √3R(30°) surface structure show only mild surface oxidation after 24 h in air, as measured by Auger electron spectroscopy. X-ray diffraction and Raman spectroscopy measurements performed in air without any protective capping, as well as, for comparison, with a thin Al 2 O 3 cap, showed the (002) reflection and the G, D and 2D Raman structures, which are unique fingerprints of thick multilayer silicene. (letter)

Una propuesta para incorporar más semántica de los modelos al código generado

OpenAIRE

Pérez Lovelle, Sonia; Cue Galindo, Julio C.; Hernández Perenzuela, Alexei; Arredondo López, Andry; Recio Nápoles, Luis R.; Carnero González, Frances

2014-01-01

Actualmente hay un amplio uso del paradigma Model Driven Architecture (MDA) para la generación de código a partir de modelos, pues esto garantiza menores tiempos de desarrollo y de puesta a punto. Los modelos creados a partir de los diagramas del Lenguaje Unificado de Modelado (UML) son de amplia utilización teniendo en cuenta que se trata de un estándar y además, la gran cantidad de herramientas de modelado que existen para ello. Cada diagrama de UML es un punto de vista diferente del sistem...

Assessment of health-cost externalities of air pollution at the national level using the EVA model system

Energy Technology Data Exchange (ETDEWEB)

Brandt, J.; Silver, J.D.; Frohn, L.M. (and others)

2011-07-15

Air pollution has significant negative impacts on human health and well-being, which entail substantial economic consequences. We have developed an integrated model system, EVA (External Valuation of Air pollution; Frohn et al., 2005; Andersen et al., 2007; Brandt et al., 2010), to assess health-related economic externalities of air pollution resulting from specific emission sources or sectors. The EVA system was initially developed to assess externalities from power production, but in this study it is extended to evaluate costs at the national level from all major emission sectors. In this study, we estimate the impacts and total externality costs from the main emission sectors in Denmark, representing the 10 major SNAP codes. Furthermore, we assess the impacts and externality costs of all emissions simultaneously from the whole of Europe as well as from international ship traffic in general, since this sector seems to be very important but is currently unregulated. (Author)

The oxidation behaviour of sprayed MCrAlY coatings

International Nuclear Information System (INIS)

Brandl, W.; Toma, D.; Krueger, J.

1996-01-01

Turbine blades are protected against high temperature oxidation by thermal barrier coating (TBC) systems, which consist of a ceramic top coating (ZrO 2 /Y 2 O 3 ) and a metal bond coating (MCrAlY, M = Ni, Co). At high temperatures and under oxidative conditions, between the MCrAlY and the ceramic top coating an oxide scale is formed, which protects the metal against further oxidation. The oxidation behaviour of the thermally sprayed MCrAlY is influenced by the coating process and the composition of the metal alloys. This work is concerned with the isothermal oxidation behaviour of vacuum plasma sprayed (VPS) MCrAlY coatings. The MCrAlY powders used have different aluminium contents: 8 and 12 wt.%. The MCrAlY specimens are oxidized at 1050 C in air as well as in helium with 1% O 2 and the oxidation kinetics are determined thermogravimetrically. The microstructure, morphology and thickness of the oxide scales formed are characterized by metallography, SEM, TEM and XRD. After short time oxidation (6 h) θ-Al 2 O 3 is the main constituent of the oxide scale. Exposure times of 500 h and more lead to oxide scales consisting of α-Al 2 O 3 . Moreover, after a long time oxidation, Cr 2 O 3 and CoO (CoO on the coatings with 8 wt.% Al) are formed. The oxidation rates of both MCrAlY coatings are the same. Beneath the oxide scale an Al-depleted zone is formed and this zone is considerably thicker within the coating with 8 wt.% Al, because the amount of β-NiAl phase in this coating is lower than that in the coating with 12 wt.% Al. The oxide scale formed in He-1% O 2 consists of α-Al 2 O 3 and Cr 2 O 3 on both MCrAlY coatings. (orig.)

La inserción al Asia-Pacífico, oportunidades y desafíos para el Valle del Cauca y la región pacífica colombiana

Directory of Open Access Journals (Sweden)

Ricardo Coutin

2014-12-01

Full Text Available Resumen: El objetivo general del texto es brindar una aproximación a los retos y las oportunidades que representa, para el Valle del Cauca y la Región Pacífica colombiana, la inserción al Asia-Pacífico. Para lo cual se plantean tres objetivos específicos: primero, analizar someramente el contexto económico comercial del Asia-Pacífico y América Latina, con especial énfasis en Colombia y los demás países de la Alianza del Pacífico (AP; segundo, estudiar las oportunidades y los retos para el Valle del Cauca y la Región Pacífica colombiana que plantea la puesta en escena del bloque comercial denominado Alianza del Pacífico; y tercero, indagar sobre los retos de competitividad y productividad que enfrenta el Valle del Cauca y que afectan el ambiente de negocios. El documento concluye que Colombia se encuentra rezagada en su inserción con la cuenca del Asia-Pacífico; también se plantea la necesidad de abordar el tema de estudio desde un enfoque subnacional.

A long-term ultrahigh temperature application of layered silicide coated Nb alloy in air

Science.gov (United States)

Sun, Jia; Fu, Qian-Gang; Li, Tao; Wang, Chen; Huo, Cai-Xia; Zhou, Hong; Yang, Guan-Jun; Sun, Le

2018-05-01

Nb-based alloy possessed limited application service life at ultrahigh temperature (>1400 °C) in air even taking the effective protective coating strategy into consideration for last decades. In this work a long duration of above 128 h at 1500 °C in air was successfully achieved on Nb-based alloy thanked to multi-layered silicide coating. Through optimizing interfaces, the MoSi2/NbSi2 silicide coating with Al2O3-adsorbed-particles layer exhibited three-times higher of oxidation resistance capacity than the one without it. In MoSi2-Al2O3-NbSi2 multilayer coating, the Al2O3-adsorbed-particles layer playing as an element-diffusion barrier role, as well as the formed porous Nb5Si3 layer as a stress transition zone, contributed to the significant improvement.

Structure, tribological and electrochemical properties of low friction TiAlSiCN/MoSeC coatings

International Nuclear Information System (INIS)

Bondarev, A.V.; Kiryukhantsev-Korneev, Ph.V.; Sheveyko, A.N.; Shtansky, D.V.

2015-01-01

Highlights: • TiAlSiCN/MoSeC coatings for tribological applications. • Doping with MoSeC reduces friction coefficient in humid air from 0.8–0.9 to 0.05. • Doping with MoSeC increases wear resistance by one-two orders of magnitude. • TiAlSiCN/MoSeC coatings demonstrated low friction coefficient in distilled water. • TiAlSiCN/MoSeC coatings showed superior tribological properties at moderate temperatures. - Abstract: The present paper is focused on the development of hard tribological coatings with low friction coefficient (CoF) in different environments (humid air, distilled water) and at elevated temperatures. TiAlSiCN/MoSeC coatings were deposited by magnetron sputtering of four-segment targets consisting of quarter circle TiAlSiCN segments, obtained by self-propagating high-temperature synthesis, and one or two cold pressed segments made of MoSe 2 and C powders in a ratio 1:1 wt%. The structure and phase composition of coatings were investigated by means of X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The coatings were characterized in terms of their hardness, elastic modulus, and elastic recovery. The tribological properties of coatings were investigated first at room temperature against Al 2 O 3 and WC–Co balls, after which studied in distilled water and during continuous heating in air in the temperature range of 25–400 °C against Al 2 O 3 counterpart material. To evaluate their electrochemical characteristics, the coatings were tested in 1 N H 2 SO 4 solution. The obtained results show that the coating hardness depends on the amount of MoSeC additives and decreased from 40 to 28 (one MoSeC segment) and 12 GPa (two MoSeC segments). Doping with MoSeC resulted in a significant reduction of CoF values measured in humid air (RH 60 ± 5%) from 0.8–0.9 to 0.05 and an increase of wear resistance by one or two orders of magnitude depending on counterpart material. This was attributed

Structure, tribological and electrochemical properties of low friction TiAlSiCN/MoSeC coatings

Energy Technology Data Exchange (ETDEWEB)

Bondarev, A.V.; Kiryukhantsev-Korneev, Ph.V.; Sheveyko, A.N.; Shtansky, D.V., E-mail: shtansky@shs.misis.ru

2015-02-01

Highlights: • TiAlSiCN/MoSeC coatings for tribological applications. • Doping with MoSeC reduces friction coefficient in humid air from 0.8–0.9 to 0.05. • Doping with MoSeC increases wear resistance by one-two orders of magnitude. • TiAlSiCN/MoSeC coatings demonstrated low friction coefficient in distilled water. • TiAlSiCN/MoSeC coatings showed superior tribological properties at moderate temperatures. - Abstract: The present paper is focused on the development of hard tribological coatings with low friction coefficient (CoF) in different environments (humid air, distilled water) and at elevated temperatures. TiAlSiCN/MoSeC coatings were deposited by magnetron sputtering of four-segment targets consisting of quarter circle TiAlSiCN segments, obtained by self-propagating high-temperature synthesis, and one or two cold pressed segments made of MoSe{sub 2} and C powders in a ratio 1:1 wt%. The structure and phase composition of coatings were investigated by means of X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The coatings were characterized in terms of their hardness, elastic modulus, and elastic recovery. The tribological properties of coatings were investigated first at room temperature against Al{sub 2}O{sub 3} and WC–Co balls, after which studied in distilled water and during continuous heating in air in the temperature range of 25–400 °C against Al{sub 2}O{sub 3} counterpart material. To evaluate their electrochemical characteristics, the coatings were tested in 1 N H{sub 2}SO{sub 4} solution. The obtained results show that the coating hardness depends on the amount of MoSeC additives and decreased from 40 to 28 (one MoSeC segment) and 12 GPa (two MoSeC segments). Doping with MoSeC resulted in a significant reduction of CoF values measured in humid air (RH 60 ± 5%) from 0.8–0.9 to 0.05 and an increase of wear resistance by one or two orders of magnitude depending on

Pensar-habitar, reconceptualizar El cuerpo: Fugas vivenciales, fugas conceptuales

Directory of Open Access Journals (Sweden)

Elizabeth Quiñónez Toro

2008-01-01

Full Text Available Se abordan en este documentos dos perspectivas sobre el cuerpo: la perspec - tiva cognitiva, que retoma la discusión merleaupontiana frente a Descartes y la separación entre el sujeto cognoscente y los objetos a conocer. Segundo, la perspectiva feminista que se ocupa del enfrentamiento entre el mundo de la cultura –en el cual se inscribe al varón, y el mundo de la biología desde el cual se significa a la mujer como cuerpo-objeto–. Se retoman algunas pro - puestas respecto al retorno al mundo orden simbólico de la madre, propuesto por Luisa Muraro como un puente hacia la re-viviscencia de la mujer como cuerpo-sujeto, o cuerpo de sujeto.

Análisis de la participación en la transición hacia el gobierno por comunas de la ciudad de Buenos Aires

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Ana Inés Heras Monner Sans

2007-01-01

Full Text Available En este escrito se analizan las instancias del proceso de transición hacia el Gobierno por Comunas en la Ciudad Autónoma de Buenos Aires, Argentina, con énfasis en el contexto político administrativo y legal, y en las formas que asume la participación mediante la descripción e interpretación de situaciones de interacción cara a cara en dos Comunas de la Ciudad. La división territorial de la Ciudad de Buenos Aires en Comunas, y la descentralización de algunas funciones del Gobierno de la Ciudad en los gobiernos comunales, son parte de los instrumentos y mecanismos de democracia participativa, definidos por la Constitución de la Ciudad de Buenos Aires del año 1996. El análisis nos permite ver que, si bien las Comunas fueron imaginadas como la herramienta más adecuada para concretar nuevas formas de organización democrática, a más de diez años de haberse aprobado dicha Constitución y habiendo superado largamente todos los plazos previstos, quienes componen la clase política han logrado postergar por más de 12 años la puesta en marcha de esta forma innovadora de gobierno local. Además, de distintas maneras han ido imponiendo la misma lógica política que el espíritu de la Constitución se proponía contrarrestar, es decir, se ha impuesto un nivel alto de concentración política en vez de garantizar una participación amplia, directa y no mediada por las estructuras político partidarias.

Comportamiento al margen de la ley: contrabando y sociedad en Buenos Aires en el siglo XVII *

Directory of Open Access Journals (Sweden)

Macarena Perusset Veras

2007-06-01

Full Text Available Illicit Behavior: Smuggling and Society in Seventeenth-Century Buenos Aires ABSTRACTIn this work we look into the origins of illegal commerce to analyze how contraband was conducted in the port of Buenos Aires in the early seventeenth-century. To do this, we will analyze the political and economic context in which contraband arose and gained importance in order to reflect whether this economic practice -conducted by government officials, vecinos (official residents and settlers of the port of Buenos Aires- can be considered corrupt in the context of the period studied. We will situate the behavior of these social actors within an intertwined complex of political beliefs and ideologies, and conjunctures, to explain how a practice like colonial-era contraband has multiple, tightly related causes.

Thioaluminogermanate M(AlS2)(GeS2)4 (M = Na, Ag, Cu): Synthesis, Crystal Structures, Characterization, Ion-Exchange and Solid-State 27Al and 23Na NMR Spectroscopy

KAUST Repository

Alahmary, Fatimah S.

2018-03-14

The new thioaluminogermanate Na(AlS2)(GeS2)4 (1) was successfully synthesized by a direct combination reaction. The compound crystallizes in the monoclinic space group P21/n (no. 14) with unit cell parameters a = 6.803(3) Å, b = 38.207(2) Å, c = 6.947(4) Å, and β = 119.17(3)°. The crystal structure is composed of a [(AlS2)(GeS2)4]− 3D polyanionic network, in which Al and Ge atoms share the atomic positions and Na cations occupy the channels and voids formed by the connection of (Ge/Al)S4 tetrahedra. The title compound shows a cation-exchange property with monovalent Ag+ and Cu+ ions at room temperature in solvent media, resulting in the formation of the isostructural compounds Ag(AlS2)(GeS2)4 (2) and Cu(AlS2)(GeS2)4 (3), respectively. The ion-exchange products Ag(AlS2)(GeS2)4 (2) and Cu(AlS2)(GeS2)4 (3) show higher air stability and narrower bandgap energies compared to those of the parent compound Na(AlS2)(GeS2)4 (1).

Thioaluminogermanate M(AlS2)(GeS2)4 (M = Na, Ag, Cu): Synthesis, Crystal Structures, Characterization, Ion-Exchange and Solid-State 27Al and 23Na NMR Spectroscopy

KAUST Repository

Alahmary, Fatimah S.; Davaasuren, Bambar; Emwas, Abdul-Hamid M.; Rothenberger, Alexander

2018-01-01

The new thioaluminogermanate Na(AlS2)(GeS2)4 (1) was successfully synthesized by a direct combination reaction. The compound crystallizes in the monoclinic space group P21/n (no. 14) with unit cell parameters a = 6.803(3) Å, b = 38.207(2) Å, c = 6.947(4) Å, and β = 119.17(3)°. The crystal structure is composed of a [(AlS2)(GeS2)4]− 3D polyanionic network, in which Al and Ge atoms share the atomic positions and Na cations occupy the channels and voids formed by the connection of (Ge/Al)S4 tetrahedra. The title compound shows a cation-exchange property with monovalent Ag+ and Cu+ ions at room temperature in solvent media, resulting in the formation of the isostructural compounds Ag(AlS2)(GeS2)4 (2) and Cu(AlS2)(GeS2)4 (3), respectively. The ion-exchange products Ag(AlS2)(GeS2)4 (2) and Cu(AlS2)(GeS2)4 (3) show higher air stability and narrower bandgap energies compared to those of the parent compound Na(AlS2)(GeS2)4 (1).

Influence of Al{sub 2}O{sub 3} addition on microstructure and mechanical properties of 3YSZ-Al{sub 2}O{sub 3} composites

Energy Technology Data Exchange (ETDEWEB)

Abden, Md. Jaynul [International Islamic Univ., Chittagong (Bangladesh). Dept. of Electrical and Electronic Engineering; Afroze, Jannatul Dil [Noakhali Science and Technology Univ. (Bangladesh). Faculty of Science and Engineering; Gafur, Md. Abdul [Bangladesh Council of Scientific and Industrial Research, Dhaka (Bangladesh). Pilot Plant and Process Development Centre; Chowdhury, Faruque-Uz-Zaman [Chittagong University of Engineering and Technology (Bangladesh). Dept. of Physics

2015-07-01

The effect of the amount of Al{sub 2}O{sub 3} content on microstructure, tetragonal phase stability and mechanical properties of 3YSZ-Al{sub 2}O{sub 3} composites are investigated in this study. The ceramic composites are obtained by means of uniaxial compacting at 210 MPa and green compacts are sintered at 1550 C for 3 h in air. The monoclinic zirconia (m-ZrO{sub 2}) phase has completely been transformed into tetragonal zirconia (t-ZrO{sub 2}) phase with corresponding higher Al{sub 2}O{sub 3} content. The t-ZrO{sub 2} grains induce transgranular fracture mode that has contribution in improvement of fracture toughness. The maximum flexural strength of 340 MPa, Vickers hardness value of 14.31 GPa and fracture toughness of 5.1 MPa x m{sup 1/2} in the composition containing 40 wt.-% Al{sub 2}O{sub 3} is attributed to the microstructure with t-ZrO{sub 2} grains as inter- and intragranular particles in the Al{sub 2}O{sub 3} grains, which makes it suitable for dental applications.

Forcing of a photochemical air quality model with atmospheric fields simulated by a regional climate model

CSIR Research Space (South Africa)

Naidoo, M

2010-10-01

Full Text Available to the enhanced greenhouse effect (e.g. Engelbrecht et al, 2009). Such changes are likely to influence the future transport and chemistry of air pollutants over the region. The complexity in which climate change may affect regional air quality is evident...

Oxidation-induced crack healing in Ti3AlC2 ceramics

NARCIS (Netherlands)

Song, G.M.; Pei, Y.T.; Sloof, W.G.; Li, S.B.; Hosson, J.Th.M. De; Zwaag, S. van der

Crack healing of Ti3AlC2 was investigated by oxidizing a partially pre-cracked sample. A crack near a notch was introduced into the sample by tensile deformation. After oxidation at 1100 degrees C in air for 2 h, the crack was completely healed, with oxidation products consisting primarily of

Theoretical calculation of solid particles deposition from the air

Directory of Open Access Journals (Sweden)

Bobro Milan

2002-03-01

Full Text Available This paper presents the calculation of harmful substance deposition (air pollution from the point source (Slanèo, et al., 2001 using equation (1. The point source shall be understood as e.g. chimneys of factory, heat plant, incinerator, boiler plant, local heating plant, etc.The theoretical calculation of concentration (1, or deposition (8 is based on the study of transfer and dispersion of pollution in air (Slanèo, et al., 2000a. The movement of pollution in air consists of a movement of the air itself and a relative movement of pollution particles and air, while the movement of harmful substance in the smoke trail is under the influence of turbulent diffusion, convection and gravitation. Molecular diffusion is not important in this process. When calculating concentrations (1 and deposition (8 of air pollution on a particular place near the source, it is assumed that the air speed is constant, the direction of wind does not change with the height and the source of air pollution is time-constant. The change in the wind speed with the height depends on the stability class of atmosphere (temperature gradient (Slanèo, et al., 2000a and it is calculated using equation (10.The theoretical calculation of concentration and or deposition of harmful substance from the point source (1 and (8 shall be applied if the harmful substance particles, which leave the source, have the same density (composition, shape (spherical and size.The experimental observations of dust deposition showed the significance of 0.1-20 µm particles. The application of equation (1 to calculate the concentration is conditioned, in addition to the recognition of source parameters and meteorological conditions, by the recognition of the particle sedimentation speed, which changes with the size of particle radius (2.For a practical calculation of deposition it is therefore necessary to know the differential distribution function f(r of particle radii, which can be made on the basis

Islamic Content On Malaysian TV: A Case study of TV Al Hijrah

Directory of Open Access Journals (Sweden)

Juliana Abdul Wahab

2017-12-01

Full Text Available Religion and media are converging and frequently becoming a subject matter for news content and popular entertainment programmes in television and film, publishing, music as well as the new media. Religion, arguably has become part and parcel of the media environment today. In Malaysian context, during the millennium era, many locally produced ‘Islamic programmes’ started to gain popularity among Malaysian audience especially within the entertainment genre such as television drama. With the establishment of Malaysian first Islamic free-to-air television, TV Al Hijrah in 2010, this paper aims to understand the nature of Islamic content available on the station. The preliminary findings of this paper suggest that there are varieties of television programmes created and aired on TV Al Hijrah cutting across different genres meant for disseminating Islam as a way of life. Programmes available are mainly about showcasing the values of Islamic teaching and beliefs with the ultimate goal to highlight Islam as a beautiful and peaceful religion.

Co-depositing Sn controls the growth of Al films as surfactant

International Nuclear Information System (INIS)

Barna, P. B.; Kovacs, A.; Misjak, F.; Eisenmenger-Sittner, C.; Bangert, H.; Tomastik, C.

2002-01-01

The present study investigates the influence of co-deposited Sn on the atomic processes involved in the structure evolution of vapour-deposited Al films. The films were prepared in HV by thermal evaporation from W sources at 1600 C substrate temperature either on Si wafers covered by a thermally grown oxide or on air cleaved mica. By applying the half-shadow technique, pure and Sn-doped Al films could be deposited simultaneously. The samples were investigated by AFM, scanning AES, X-TEM as well as by X-ray diffraction methods. The grain growth of Al is promoted by Sn in all stages of the film formation. Scanning AES measurements prove the existence of a wetting Sn layer both on the surface of Al islands and on the surface of the continuos Al layer. Excess Sn forms islands on the growth surface. The surface of pure Al layers exhibits grain boundary grooves and bunches of growth steps around terraces, while that of the Sn doped layers is more rounded. The substrate-film interface was covered by a thin Sn layer. AES measurements also prove the presence of Sn on the growth surface of Al films even after termination of Sn addition. Results of these experiments indicate that during co-deposition of Al and Sn the impinging Al atoms penetrate the wetting layer and are incorporated into the already existing Al crystals. A model has been developed for describing the growth of Al crystals in the presence Sn. (Authors)

Modelling the air flow in symmetric and asymmetric street canyons

Energy Technology Data Exchange (ETDEWEB)

Santiago, J.L.; Martin, F. [Research Center for Energy, Environment and Technology (CIEMAT), Madrid (Spain). Fossil Fuels Dept., Numerical Simulation and Modelling Program

2004-07-01

In recent years a large amount of research has been conducted on urban scale and street canyon. Control of air quality inside cities is important for human health. To achieve this objective, street canyon modelling plays a significant role. Pollutant dispersion inside canyons are determined by wind flow around this complex geometry. Experimental investigations have been made by means of field measurements such as Vachon, G. et al. or wind tunnel experiences as Meroney, R.N. et al. or Kastner-Klein, P. and E.J. Plate. In many of these researches, they have used CFD models in several configurations, for instance Assimakopoulos, V.D. et al. or Sini, J.-F. et al. These models are based on a numerical resolution of Navier-Stokes equations with a turbulence closure. In this study, the aim is contribute to the understanding of air circulation inside street canyons. In order to achieve this purpose, several configurations of canyons are investigated. Two-dimensional sequences of real-scale street canyons (order to obstacles height is meters) with different features (symmetric canyons and asymmetric canyons forming step-up and step-down notch configurations) are simulated. These general configurations are modified to investigate some parameters such as aspect ratio, W/H, where W is the width of street and H is the height of buildings. Flows with high Reynolds numbers are modelling. FLUENT CFD software is used. (orig.)

The IPEM code of practice for determination of the reference air kerma rate for HDR 192Ir brachytherapy sources based on the NPL air kerma standard

International Nuclear Information System (INIS)

Bidmead, A M; Sander, T; Nutbrown, R F; Locks, S M; Lee, C D; Aird, E G A; Flynn, A

2010-01-01

This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR 192 Ir brachytherapy sources. In 2004, the National Physical Laboratory (NPL) commissioned a primary standard for the realization of RAKR of HDR 192 Ir brachytherapy sources. This has meant that it is now possible to calibrate ionization chambers directly traceable to an air kerma standard using an 192 Ir source (Sander and Nutbrown 2006 NPL Report DQL-RD 004 (Teddington: NPL) http://publications.npl.co.uk). In order to use the source specification in terms of either RAKR, .K R (ICRU 1985 ICRU Report No 38 (Washington, DC: ICRU); ICRU 1997 ICRU Report No 58 (Bethesda, MD: ICRU)), or air kerma strength, S K (Nath et al 1995 Med. Phys. 22 209-34), it has been necessary to develop algorithms that can calculate the dose at any point around brachytherapy sources within the patient tissues. The AAPM TG-43 protocol (Nath et al 1995 Med. Phys. 22 209-34) and the 2004 update TG-43U1 (Rivard et al 2004 Med. Phys. 31 633-74) have been developed more fully than any other protocol and are widely used in commercial treatment planning systems. Since the TG-43 formalism uses the quantity air kerma strength, whereas this COP uses RAKR, a unit conversion from RAKR to air kerma strength was included in the appendix to this COP. It is recommended that the measured RAKR determined with a calibrated well chamber traceable to the NPL 192 Ir primary standard is used in the treatment planning system. The measurement uncertainty in the source calibration based on the system described in this COP has been reduced considerably compared to other methods based on interpolation techniques.

Electrical Properties of a Thin Anodized Capacitor Made of Y-Doped Al Alloy Film

Science.gov (United States)

Onozuka, Tomotake; Sasaki, Hayato; Mikuni, Naohiro; Shinkai, Satoko; Sasaki, Katsutaka; Yamane, Misao; Abe, Yoshio

2005-09-01

We have prepared an Al-Y anodized capacitor using sputter-deposited Al-Y alloy film with 5 at. % Y atoms, and evaluated the capacitor properties and the leakage current properties before and after heat treatment. In addition, the characterization of Al-Y anodized films was examined by X-ray diffraction, Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy analyses. As a result, it is revealed that the thermal stability of an Al-Y anodized capacitor is superior to that of a pure Al anodized capacitor because of its excellent passive nature, and the loss properties can be improved by increasing the heat treatment temperature in air because of the reduction of the equivalent series resistance. Furthermore, it is clarified that the cause of the short-circuited state observed at 550°C is the formation of a narrow capillary-like conduction path of metallic Al atoms as a result of the interdiffusion of Al.

Air Force Civil Engineer, Volume 10, Number 1, Spring 2002

Science.gov (United States)

2002-01-01

gone into the 823rd Expeditionary RED HORSE Squadron�s military construction (MILCON) funded ramp project at Al Udeid Air Base, Qatar , and the main...AE W P ub lic A ff ai rs an Air Base RED HORSE builds MILCON project in Qatar SSgt Chuck Risinger, 823rd RHS, operates a slip form paver March 24...and were not designed to limit or contain the migration of lead into the environ- ment and sub-surface groundwater aquifers . An estimated 2,000

Oxytocin, trust and corruption: a systemic theory of the road to authoritarism Oxitocina, confianza y corrupción: una teoría sistémica del camino al autoritarismo

Directory of Open Access Journals (Sweden)

Esteban Laso

2012-07-01

Full Text Available In this text I propose a systemic theory about the process through which societies become authoritarian. I postulate, at the micro or individual level, a triadic structure of tendencies towards others (trust, suspicion and hostility; and I link it, at the macro or social level, to a group of structural factors (inequity and distrust, triggers (social, economical or political crisis and catalysts (presence of a caudillo with a populist discourse and authoritarian leaning.  Finally, I present some guidelines for the empirical testing of this theory.

En este texto propongo una teoría sistémica del proceso por el que las sociedades llegan al autoritarismo populista. Postulo, en el nivel individual o micro, una estructura triádica de disposiciones hacia el otro (confianza, suspicacia y hostilidad; y la vinculo, en el nivel social o macro, con un conjunto de factores estructurales (inequidad y desconfianza, sucesos precipitantes (crisis social, económica o política y catalizadores (presencia de un líder caudillista de discurso populista e inclinación autoritaria. Finalmente, expongo algunos lineamientos para la puesta a prueba empírica de esta teoría.

Pollution trends using bark of morus alba in the cities of buenos aires and mendoza (Argentina Tendências de poluição usando cascas de morus alba nas cidades de buenos aires e mendoza (Argentina

Directory of Open Access Journals (Sweden)

Patricia Perelman

2010-06-01

Full Text Available A comparative study of elements deposited on tree bark was carried out for urban and periurban areas of two of the most important cities in Argentina. The content of Fe, Mg, Al, Mn, Zn, Pb, Ba, Cr, Hg, Cu, Ni, Cd and Sb was determined by inductively coupled plasma atomic emission spectrometry (ICP-OES in Morus alba tree bark collected in the cities of Buenos Aires and Mendoza. The main air pollutants detected in the Buenos Aires urban area were Ba, Cr, Cu and Ni and indicate significative difference from the Mendoza urban and periurban areas. Significantly, higher concentrations of Zn, Ba, Cr and Cu were recorded in the periurban area of the city of Buenos Aires than in Mendoza. Bark samples were strongly influenced by dust and show Al, Fe, Mg and other element accumulations that indicate that soil particles were carried out by wind. Elements like Ba and Zn, commonly linked to traffic emissions, showed the highest concentrations in the Buenos Aires metropolitan area, possibly due to more intensive vehicular traffic. Our results indicated that intensity of vehicular traffic and not city structure is responsible for air pollution.Um estudo comparativo dos elementos depositados nas cascas das árvores foi realizado nas áreas urbanas e na periferia de duas cidades das mais importantes da Argentina. Os índices do Fe, Mg, Al, Mn, Zn, Pb, Ba, Cr, Cu, Ni e do Sb foram determinados pela espectrometria da emissão atômica com plasma acoplado indutivamente (ICP-OES nas cascas da árvore Morus alba, coletados nas cidades de Buenos Aires e Mendoza. Os principais elementos da contaminação do ar detectadas na área urbana de Buenos Aires foram Ba, Cr, Cu e Ni, que indicaram diferenças significativas nas áreas urbanas e na periferia de Mendoza. Uma concentração do Zn, Ba, Cr e do Cu foi achada na periferia da cidade de Buenos Aires, significativamente mais elevada do que em Mendoza. As amostras da casca foram influenciadas fortemente pela poeira e

Refining of cast intermetallic alloy Ti - 43 % Al - X (Nb, Mo, B) microstructure using heat treatment

International Nuclear Information System (INIS)

Imaev, R.M.; Imaev, V.M.; Khismatullin, T.G.

2006-01-01

The microstructure and high temperature mechanical properties are studied in a cast alloy Ti - 43 % Al - X (Nb, Mo, B) using methods of optical and scanning electron microscopy, X ray spectrum microanalysis and differential thermal analysis. The alloy belongs to a new class of β-solidifying γ-TiAl+α 2 -Ti 3 Al alloys. The alloy is investigated as cast and after heat treatment that promotes grain refinement. Mechanical properties are determined on tensile tests at 1000 and 1100 deg C in the air [ru

Penyisihan Limbah Organik Air Lindi TPA Jatibarang Menggunakan Koagulasi-Flokulasi Kimia

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Arya Rezagama

2016-12-01

Full Text Available Air lindi yang meresap ke dalam tanah yang berpotensi bercampur dengan air tanah sehingga menimbulkan pencemaran tanah, air tanah dan air permukaan. Komposisi limbah lindi dari berbagai TPA berbeda-beda bergantung pada musim, jenis limbah, umur TPA. Proses dalam TPA menghasilkan molekul organik recalcitrant yang ditunjukkan dengan rendahnya rasio BOD/COD dan tingginya nilai NH3-N. Belum optimalnya pengolahan air lindi di Jatibarang membutuhkan pretreatment sebagai bentuk upaya alternatif dalam proses pengolahan air lindi sebelum masuk ke dalam proses aerated lagun. Penelitian ini bertujuan untuk menganalisa pengaruh koagulan kimia pada penyisihan bahan organik air lindi TPA Jatibarang. Penelitian dilakukan pada bulan April- Agustus 2016. Karaktersitik air lindi TPA Jatibarang termasuk dalam kategori "moderately stable" dan lindi muda. Penyisihan bahan organik dengan menggunakan kuagulan kimia FeCl3 dan Al2SO4 menunjukkan nilai yang cukup signifikan untuk parameter COD, BOD, TSS. Penggunaan dosis optimal terjadi pada 16 g/L FeCl3 serta 16 g/L Al2SO4 dapat menurunkan nilai COD sebesar 51% dan 65%, BOD sebesar 50% dan 56%, dan TSS sebesar 24% dan 21%. Perubahan nilai pH akibat penambahan koagulan berpengaruh positif terhadap tingkat penyisihan, namun memberikan dampak negatif yaitu buih yang cukup banyak. Penurunan beban organik menguntungkan bagi sistem pengolahan lindi eksisting TPA Jatibarang.  [Title: Removal of Lindi Water Organic Waste of TPA Jatibarang using Chemical Coagulation- Floculation] Leachate grounding into the soil that potentially could mix with the groundwater caused contamination of soil, groundwater and surface water. The composition of waste landfill leachate from the various location is depending on the season, the type of waste, and landfill age. Process in the TPA produces recalcitrant organic molecules as indicated by the low ratio of BOD/COD and NH3-N high value. The ineffective treatment of leachate at Jatibarang

Mechanical properties and oxidation behaviour of (Al,Cr)N and (Al,Cr,Si)N coatings for cutting tools deposited by HPPMS

Energy Technology Data Exchange (ETDEWEB)

Bobzin, K.; Bagcivan, N.; Immich, P. [Surface Engineering Institute, RWTH Aachen University, Augustinerbach 4-22, D-52056 Aachen (Germany); Bolz, S. [Surface Engineering Institute, RWTH Aachen University, Augustinerbach 4-22, D-52056 Aachen (Germany)], E-mail: info1@iot.rwth-aachen.de; Cremer, R.; Leyendecker, T. [CemeCon AG, Wuerselen (Germany)

2008-12-01

Hard coatings with high hardness, high oxidation resistance and thermal stability are used for economical machining. In this regard nanostructured (Cr,Al)N and nc-(Cr,Al)N/a-Si{sub 3}N{sub 4} films were sputtered on tungsten carbide tools and WC/Co samples by using the HPPMS (High Power Pulse Magnetron Sputtering) technology. The relationship between coating composition, microstructure and mechanical properties was investigated by using X-ray diffraction, Scanning Electron Microscopy (SEM), and Nanoindentation. The maximum hardness value was about 40 GPa. For the coatings the Al-content was varied from 10-90 at.% while the silicon content was about 5 at.% for the (Cr,Al,Si)N. As this study focuses on oxidation behaviour of the deposited coatings, annealing tests were carried out in air at 1000 deg. C . HPPMS is a promising technology to ensure a uniform coating distribution, especially for complex shaped substrates like cutting tools or moulds. SEM pictures of the cross section have been taken around the cutting edge to determine the deposition rate and the film growth. The coatings morphology has been compared to m. f. (middle frequency)- and d. c. (direct current)-sputtered nanocomposite (Cr,Al,Si)N films indicating enhanced properties due to the application of the HPPMS-technology with regard to denser structure, higher hardness, favourable surface topography and better thickness uniformity.

Ductility and fracture behavior of polycrystalline Ni/sub 3/Al alloys

International Nuclear Information System (INIS)

Liu, C.T.

1987-01-01

This paper provides a comprehensive review of the recent work on tensile ductility and fracture behavior of Ni/sub 3/Al alloys tested at ambient and elevated temperatures. Polycrystalline Ni/sub 3/Al is intrinsically brittle along grain boundaries, and the brittleness has been attributed to the large difference in valency, electronegativity, and atom size between nickel and aluminum atoms. Alloying with B, Mn, Fe, and Be significantly increases the ductility and reduces the propensity for intergranular fracture in Ni/sub 3/Al alloys. Boron is found to be most effective in improving room-temperature ductility of Ni/sub 3/Al with <24.5 at.% Al. The tensile ductility of Ni/sub 3/Al alloys depends strongly on test environments at elevated temperatures, with much lower ductilities observed in air than in vacuum. The loss in ductility is accompanied by a change in fracture mode from transgranular to intergranular. This embrittlement is due to a dynamic effect involving simultaneously high localized stress, elevated temperature, and gaseous oxygen. The embrittlement can be alleviated by control of grain shape or alloying with chromium additions. All the results are discussed in terms of localized stress concentration and grain-boundary cohesive strength

CsPbBr{sub 3} QD/AlO{sub x} inorganic nanocomposites with exceptional stability in water, light, and heat

Energy Technology Data Exchange (ETDEWEB)

Loiudice, Anna; Saris, Seryio; Buonsanti, Raffaella [Department of Chemical Sciences and Engineering, EPFL Valais Wallis, Sion (Switzerland); Oveisi, Emad; Alexander, Duncan T.L. [Interdisciplinary Centre for Electron Microscopy (CIME), EPFL, Lausanne (Switzerland)

2017-08-28

Herein, the assembly of CsPbBr{sub 3} QD/AlO{sub x} inorganic nanocomposites, by using atomic layer deposition (ALD) for the growth of the amorphous alumina matrix (AlO{sub x}), is described as a novel protection scheme for such QDs. The nucleation and growth of AlO{sub x} on the QD surface was thoroughly investigated by miscellaneous techniques, which highlighted the importance of the interaction between the ALD precursors and the QD surface to uniformly coat the QDs while preserving the optoelectronic properties. These nanocomposites show exceptional stability towards exposure to air (for at least 45 days), irradiation under simulated solar spectrum conditions (for at least 8 h), and heat (up to 200 C in air), and finally upon immersion in water. This method was extended to the assembly of CsPbBr{sub x}I{sub 3-x} QD/AlO{sub x} and CsPbI{sub 3} QD/AlO{sub x} nanocomposites, which were more stable than the pristine QD films. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Signal compression in radar using FPGA

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Enrique Escamilla Hemández

2010-01-01

Full Text Available El presente artículo muestra la puesta en práctica de hardware para realizar el procesamiento en tiempo real de la señal de radar usando una técnica simple, rápida basada en arquitectura de FPGA (Field Programmable Gate Array. El proceso incluye diversos procedimientos de enventanado durante la compresión del pulso del radar de apertura sintética (SAR. El proceso de compresión de la señal de radar se hace con un filtro acoplado. que aplica funciones clásicas y nuevas de enventanado, donde nos centramos en obtener una mejor atenuación para los valores de lóbulos laterales. La arquitectura propuesta explota los recursos de computación paralela de los dispositivos FPGA para alcanzar una mejor velocidad de cómputo. Las investigaciones experimentales han demostrado que los mejores resultados para el funcionamiento de la compresión del pulso se han obtenido usando las funciones atómicas, mejorando el funcionamiento del sistema del radar en presencia de ruido, y consiguiendo una pequeña degradación en la resolución de rango. La puesta en práctica del tratamiento de señales en el sistema de radar en tiempo real se discute y se justifica la eficiencia de la arquitectura de hardware propuesta.

Air pollution exposure is associated with restrictive ventilatory patterns

NARCIS (Netherlands)

de Jong, Kim; Vonk, Judith M.; Zijlema, Wilma L.; Stolk, Ronald P.; van der Plaat, Diana A.; Hoek, Gerard; Brunekreef, Bert; Postma, Dirkje S.; Boezen, H. Marike

2016-01-01

Exposure to ambient air pollution is associated with a substantial burden of morbidity and mortality worldwide [1]. In a recent paper, Adam et al. [2] showed significantly impaired levels of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) associated with exposure to the

Spallation of oxide scales from NiCrAlY overlay coatings

International Nuclear Information System (INIS)

Strawbridge, A.; Evans, H.E.; Ponton, C.B.

1997-01-01

A common method of protecting superalloys from aggressive environments at high temperatures is by plasma spraying MCrAlY (M = Fe, Ni and/or Co) to form an overlay coating. Oxidation resistance is then conferred through the development of an alumina layer. However, the use of such coatings is limited at temperatures above about 1100 C due to rapid failure of the protective oxide scales. In this study, the oxidation behaviour of air-plasma-sprayed NiCrAlY coatings has been investigated at 1200 C in 1 atm air. A protective alumina layer develops during the early stages, but breakaway oxidation occurs after prolonged exposure. The results suggest that the critical temperature drop to initiate failure is inversely proportional to the scale thickness, and an analytical model is put forward to explain this behaviour. Local surface curvature of the coating can lead to delamination within the oxide during cooling and it is shown that the largest individual pore in a spall region is the critical flaw for oxide fracture. (orig.)

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.

Escrito en el aire: confabulación de escrituras

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Rosa Sarabia

2014-03-01

Full Text Available En 1964, Rafael Alberti y León Ferrari publican juntos Escrito en el aire. Se trata de 9 poemas visuales a cargo del poeta gaditano que responden a 9 dibujos escritos por el artista argentino. En consonancia con las experimentaciones de las vanguardias, Escrito en el aire cuestionaría conceptos epistemológicos respecto al lugar de la escritura en la cultura e historia de nuestra civilización occidental. El presente estudio propone una lectura de Escrito en el aire centrada en la materialidad visual de la escritura. Los versos que dibujan quebrando la horizontalidad de la línea se confabulan con las escrituras ilegibles de los dibujos a modo de gesto hacia el pensamiento multisensorial pre-alfabético.

Fabrication of FeAl Intermetallic Foams by Tartaric Acid-Assisted Self-Propagating High-Temperature Synthesis

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Krzysztof Karczewski

2018-04-01

Full Text Available Iron aluminides are intermetallics with interesting applications in porous form thanks to their mechanical and corrosion resistance properties. However, making porous forms of these materials is not easy due to their high melting points. We formed FeAl foams by elemental iron and aluminum powders sintering with tartaric acid additive. Tartaric acid worked as an in situ gas-releasing agent during the self-propagating high-temperature synthesis of FeAl intermetallic alloy, which was confirmed by X-ray diffraction measurements. The porosity of the formed foams was up to 36 ± 4%. In the core of the sample, the average equivalent circle diameter was found to be 47 ± 20 µm, while on the surface, it was 35 ± 16 µm; thus, the spread of the pore size was smaller than reported previously. To investigate functional applications of the formed FeAl foam, the pressure drop of air during penetration of the foam was examined. It was found that increased porosity of the material increased the flow of the air through the metallic foam.

Análisis de la sensibilidad de biotipos de Lolium multiflorum a herbicidas inhibidores de la enzima ALS, ACCasa y Glifosato Sensitivity analysis of Lolium multiflorum biotypes to Glyphosate, ACCase and ALS-inhibiting herbicides

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P. Diez De Ulzurrun

2012-09-01

Full Text Available A pesar de los avances logrados en el control de las malezas con el uso de herbicidas, el manejo de las mismas no se simplificó, sino que, al contrario, surgieron nuevos desafíos, como la aparición de resistencia a herbicidas. En 2007, se reportó en Lolium multiflorum el segundo caso de resistencia a glifosato detectado en Argentina. En el sudeste de la provincia de Buenos Aires se registraron fallas de control a campo en poblaciones de Lolium multiflorum debido a su resistencia a distintos herbicidas de las familias de los inhibidores de ALS y de ACCasa y al herbicida glifosato. El objetivo de este estudio fue caracterizar el nivel de resistencia a ciertos herbicidas inhibidores de la ALS y de la ACCasa y al glifosato en una población de L. multiflorum de Lobería (Bs As, Argentina supuestamente resistente (LmR. Se realizaron bioensayos en cajas de Petri y se determinó la GR50 mediante la variación en la longitud de coleoptile. Las curvas de dosis-respuesta se obtuvieron por medio de la ecuación log-logística. El biotipo LmR presentó resistencia múltiple a herbicidas con tres modos de acción diferentes: glifosato, inhibidores de ALS y de ACCasa. Dicho ensayo demostró la aparición de un biotipo de L. multiflorum con resistencia a múltiples principios activos.Despite progress in weed control using herbicides, management has not been simplified, but new challenges such as herbicides resistance have arisen. In 2007, a Lolium multiflorum population resistant to glyphosate was reported, as the second case of glyphosate resistant weeds in Argentina. In the southeast of Buenos Aires province, control failures in populations of L. multiflorum to different families of herbicide such as ALS and ACCase inhibitors and to glyphosate at field level have been registered. The aim of this study was to characterize the level of resistance to certain herbicides inhibitors of ALS, ACCase and glyphosate in a putatively resistant (LmR population of L

Neuro-Linguistic Programming: Human Technology for Today’s Air Force.

Science.gov (United States)

1986-04-01

Part III, pp. 4-5. ’ 26. Ibid, p. 6. 27. Donald W. McCormick, " Neurolinguistic Programming : A Resource Guide and Review of the Research, The 1984...Carol Johnson, " Neurolinguistic Programming --Mystique or Mistake?" Army Organizational Effectiveness Journal, No. 1, 1985, pp. 74-80. 29. Dilts...AD-RI67 836 NEURO-LINGUISTIC PROGRAMMING : HUHAN TECHNOLOGY FOR / TODAY’S AIR FORCEMU AIR COMMAND ANM STAFF COLL NAXHELL AFB AL J B CAULFIELD APR 86

The influence of powder particle size on properties of Cu-Al2O3 composites

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Rajković V.

2009-01-01

Full Text Available Inert gas atomized prealloyed copper powder containing 2 wt.% Al (average particle size ≈ 30 μm and a mixture consisting of copper (average particle sizes ≈ 15 μm and 30 μm and 4 wt.% of commercial Al2O3 powder particles (average particle size ≈ 0.75 μm were milled separately in a high-energy planetary ball mill up to 20 h in air. Milling was performed in order to strengthen the copper matrix by grain size refinement and Al2O3 particles. Milling in air of prealloyed copper powder promoted formation of finely dispersed nano-sized Al2O3 particles by internal oxidation. On the other side, composite powders with commercial micro-sized Al2O3 particles were obtained by mechanical alloying. Following milling, powders were treated in hydrogen at 400 0C for 1h in order to eliminate copper oxides formed on their surface during milling. Hot-pressing (800 0C for 3 h in argon at pressure of 35 MPa was used for compaction of milled powders. Hot-pressed composite compacts processed from 5 and 20 h milled powders were additionally subjected to high temperature exposure (800°C for 1 and 5h in argon in order to examine their thermal stability. The results were discussed in terms of the effects of different size of starting powders, the grain size refinement and different size of Al2O3 particles on strengthening, thermal stability and electrical conductivity of copper-based composites.

The changing face of urban air pollution

Science.gov (United States)

Lewis, Alastair C.

2018-02-01

The atmospheric chemistry that leads to photochemical smog and climate-active aerosols requires the presence of volatile organic compounds (VOCs) (1, 2). The VOCs in urban air typically derive from the prevailing energy and transport technologies as well as the use of petrochemical-derived products. On page 760 of this issue, McDonald et al. (3) report that a notable change in emissions may be underway in U.S. cities, with effects on secondary pollutants such as organic aerosols. Shifting from an urban atmosphere dominated by transport-related VOCs to one dominated by VOCs from coatings, adhesives, and consumer products would alter predictions of urban air quality and challenge the existing policy framework for emissions control.

An Analysis of the Design-Build Delivery Approach in Air Force Military Construction

Science.gov (United States)

2008-03-01

Construction (Department of the Air Force, 2000), known as the Blue Book , for a comprehensive description of the Air Force MILCON process and policy...procurement (Mouritsen, 1993; Songer & Molenaar , 1997; Chan et al., 2002) synonymously when describing design-build methods. Delivery and procurement...broad applicability of the new approach (Buckingham, 1989; Mouritsen, 1993; Molenaar & Songer, 1998). The pendulum has now shifted away from the early

The corrosion behaviour of Zr3Al-based alloys

International Nuclear Information System (INIS)

Murphy, E.V.; Wieler, R.

1977-07-01

The corrosion resistance of several zirconium-aluminum alloys with aluminum contents ranging from 7.6 to 9.6 wt% was examined in 300 deg C and 325 deg C water, 350 deg C and 400 deg C steam and in air and wet CO 2 at 325 deg C and 400 deg C. In the transformed alloys there are three phases present, αZr, Zr 2 Al and Zr 3 Al of which the αZr phase is the least corrosion resistant. The most important factor controlling the corrosion behaviour of these alloys was found to be the size, distribution and amount of the αZr phase in the transformed alloys, which in turn was dependent upon the microstructural scale of the untransformed alloys

The Air Force Fitness Test: Creating New Fitness Assessment Charts Using Waist to Height Ratios

Science.gov (United States)

2017-03-23

Cureton et al ., 1979; Jette et al ., 1990; Vogel and Friedl, Chapter 6; Jones, Bovee, and Knapick, 1992). Jones, Bovee, and Knapick found in a study...research report, No. 2654-74, Air Command and Staff College, Maxwell AFB AL , May 1974. Taylor, R. W., Jones, I. E., Williams, S. M., & Goulding , A...from AFFMS (Callendar, 2004; Knapik, Ang, Reynolds, and Jones, 1993; Knapik, Sharp, Canham-Chervak, Hauret, Patton, Jones, 2001; Mello and Murphy, 1988

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.

Femtosecond laser ablation and nanoparticle formation in intermetallic NiAl

Energy Technology Data Exchange (ETDEWEB)

Jorgensen, David J., E-mail: davidjjorgensen@engr.ucsb.edu; Titus, Michael S.; Pollock, Tresa M.

2015-10-30

Highlights: • The single-pulse fs laser ablation threshold of NiAl is 83 mJ/cm{sup 2}. • The transition between low- and high-fluence ablation regimes is 2.8 J/cm{sup 2}. • A bimodal size distribution of nanoparticles is formed with fs laser ablation. • Smaller nanoparticles are enriched in Al during pulsed fs laser ablation. • The target surface is depleted in Al during pulsed fs laser ablation. - Abstract: The ablation behavior of a stoichiometric intermetallic compound β-NiAl subjected to femtosecond laser pulsing in air has been investigated. The single-pulse ablation threshold for NiAl was determined to be 83 ± 4 mJ/cm{sup 2} and the transition to the high-fluence ablation regime occurred at 2.8 ± 0.3 J/cm{sup 2}. Two sizes of nanoparticles consisting of Al, NiAl, Ni{sub 3}Al and NiO were formed and ejected from the target during high-fluence ablation. Chemical analysis revealed that smaller nanoparticles (1–30 nm) tended to be rich in Al while larger nanoparticles (>100 nm) were lean in Al. Ablation in the low-fluence regime maintained this trend. Redeposited material and nanoparticles remaining on the surface after a single 3.7 J/cm{sup 2} pulse, one hundred 1.7 J/cm{sup 2} pulses, or one thousand 250 mJ/cm{sup 2} pulses were enriched in Al relative to the bulk target composition. Further, the surface of the irradiated high-fluence region was depleted in Al indicating that the fs laser ablation removal rate of the intermetallic constituents in this regime does not scale with the individual pure element ablation thresholds.

Sidereal anisotropy of small air showers observed at Mt. Norikura

International Nuclear Information System (INIS)

Nagashima, K.; Sakakibara, S.; Fujimoto, K.; Fujii, Z.; Ueno, H.; Kondo, I.

1977-01-01

Observation of small air showers has been continued from August 1970, using a part of the multidirectional cosmic ray telescope at Mt. Norikura. Most significant result obtained from this observation was a sidereal diurnal anisotropy of amplitude 0.051 +- 0.004% with maximum at 1.0 +- 0.5 h, which showed a persistent trend over six years. Based on the results of the observation together with those obtained by Gombosi et al. and Fenton et al., a tentative model of sidereal anisotropies is presented. (author)

Surface Microstructure of Nanoaluminized CoCrAlY Coating Irradiated by HCPEB

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Zhiyong Han

2016-01-01

Full Text Available A thermal sprayed CoCrAlY coating was prepared by air plasma spray on the surface of Ni-based superalloy GH4169; then, a nanoscale aluminum film was deposited with electron beam vacuum deposition on it. The coatings irradiated by high-current pulsed electron beam were investigated. After HCPEB treatment, the Al film was remelted into the bond coat. XRD result shows that Al and Al2O3 phase were recorded in the irradiated and aluminized coatings, while Co-based oxides which originally existed in the initial samples disappeared. Microstructure observations reveal that the original coating with porosity, cavities, and inclusions was significantly changed after HCPEB treatment as compact appearance of interconnected bulged nodules. Moreover, the grains on the irradiated coating were very refined and homogeneously dispersed on the surface, which could effectively inhibit the corrosive gases and improve the coating oxidation resistance.

Air pollution in Copenhagen

International Nuclear Information System (INIS)

Flyger, H.; Palmgren Jensen, F.; Kemp, K.

1976-03-01

Aerosols were monitored in Greater Copenhagen in the period June 1973 to July 1974. Size-fractionated cascade impactor samples and unfractionated filter samples were regularly collected and analyzed be neutron activation analysis, spark emission spectroscopy or proton-induced X-ray emission spectroscopy. Concentrations were determined of the following elements: Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Mo, Cd, Sn, Sb, and Pb. All elements showed orders-of-magnitude fluctuationsthe mean concentrations were roughly the same as in other large cities. In relation to proposed air quality standards, Pb was the most critical component. Statistical analysis of variation patterns, size distributions and interelement correlations indicate that automotive exhaust is the source of Br and Pbfuel-oil combustion is the main source of V and Ni (and partly of S)soil dust raised by wind or by human activity (e.g. traffic) is the main source of Al, Si, Ca, Ti, and Fe. (author)

Wearproof composition coatings on the basis of SiC-AL2O3 for restoration and reiforcement of the components of aircraft ground support equipment

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О. П. Уманський

2013-07-01

Full Text Available On the ground of research of a contact interaction of the melts of the system Ni–Al with the ceramics of SiC–Al2O3 content, the possibility of wearproof coating deposition of the system SiC–Al2O3–Ni–Al by gas-flame techniques has been proved. Technological features of their acquisition also have been studied. The structure of coatings from composition material that contains the SiC–Al2O3 wearproof component and Ni–Al metallic binder, deposited by the method of high velocity air fuel deposition (HVAF on medium-carbon steel steels has been researched. Tribotechnical descriptions of the deposited coatings under the conditions of friction without lubricating materials in the air environment in wide range of speed-load modes of the “pin–on–disk” layout have been studied. The features and regularities of their wear mechanisms retaining the constant speed and constant load have been determined

Effect of atmosphere composition on the oxidation behavior of MCrAlY coatings

Energy Technology Data Exchange (ETDEWEB)

Song, P.; Subanovic, M.; Toscano, J.; Naumenko, D.; Quadakkers, W.J. [Forschungszentrum Juelich GmbH, Institute for Energy Research (IEF-2), 52425 Juelich (Germany)

2011-07-15

In the present work the effect of atmosphere composition on the growth rate and adherence of the alumina scales was studied using free-standing MCrAlY-coatings and TBC-specimens with MCrAlY-bondcoats. The exposures comprised isothermal and cyclic exposures in laboratory air and Ar-H{sub 2}-H{sub 2}O at 1100 C. It is shown that minor Zr-addition to the bondcoat results in enhanced scale growth and internal oxidation. This effect is independent of the atmosphere composition. As a consequence of the rapid oxide formation the times to TBC failure on the Zr-containing bondcoat in both atmospheres were much shorter compared to those with Zr-free bondcoat. In the latter case the formation of a thin compact alumina TGO was slower in H{sub 2}/H{sub 2}O than in air resulting in significantly longer TBC-lifetime in the former atmosphere. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Design and Analysis of a Solar-Powered Compressed Air Energy Storage System

Science.gov (United States)

2016-12-01

sized PV panel arrays. Kim et al. [49] and Manfrida et al. [50] proposed that a SS-AA- CAES system using COTS parts could be made more economical by...directly improve system efficiency. Furthermore, the power formulas derived using this approach can easily be used to both size the compressor based on...48] Villela, D., Kasinathan, V., De Valle, S., 2010, “Compressed-Air Energy Storage Systems for Stand-Alone Off-Grid Photovoltaic Modules

Bulk Synthesis and Characterization of Ti3Al Nanoparticles by Flow-Levitation Method

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Shanjun Chen

2013-01-01

Full Text Available A novel bulk synthesis method for preparing high pure Ti3Al nanoparticles was developed by flow-levitation method (FL. The Ti and Al vapours ascending from the high temperature levitated droplet were condensed by cryogenic Ar gas under atmospheric pressure. The morphology, crystalline structure, and chemical composition of Ti3Al nanoparticles were, respectively, investigated by transmission electron microscopy, X-ray diffraction, and inductively coupled plasma atomic emission spectrometry. The results indicated that the Ti3Al powders are nearly spherical-shaped, and the particle size ranges from several nanometers to 100 nm in diameter. Measurements of the d-spacing from X-ray (XRD and electron diffraction studies confirmed that the Ti3Al nanoparticles have a hexagonal structure. A thin oxidation coating of 2-3 nm in thickness was formed around the particles after exposure to air. Based on the XPS measurements, the surface coating of the Ti3Al nanoparticles is a mixture of Al2O3 and TiO2. The production rate of Ti3Al nanoparticles was estimated to be about 3 g/h. This method has a great potential in mass production of Ti3Al nanoparticles.

A preliminary assessment of the Montréal process indicators of air pollution for the United States

Science.gov (United States)

John W. Coulston; Kurt H. Riitters; Grethchen C. Smith

2004-01-01

Air pollutants pose a risk to forest health and vitality in the United States. Here we present the major findings from a national scale air pollution assessment that is part of the United States’ 2003 Report on Sustainable Forests. We examine trends and the percent forest subjected to specific levels of ozone and wet deposition of sulfate, nitrate, and ammonium....

Parámetros reproductores de la gaviota patiamarilla Larus michahellis lusitanius Naumann, 1840 en Gipuzkoa

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ARAIZAGA, J., ALDALUR, A., CUADRADO, J.F., DIEZ, E., GOIKOETXEA, J., HERRERO, A., JAUREGI, J.I., LASO, M., SANCHEZ, J.M.

2012-01-01

Full Text Available El objetivo del presente artículo es estudiar la reproducción de la gaviota patiamarilla Larus michahellis lusitanius Naumann, 1840 en Gipuzkoa. En particular, analizamos (1 el tamaño de puesta (número de huevos/nido, (2 la fecha de eclosión, (3 el número de huevos eclosionados/nido y (4 la proporción de huevos eclosionados en relación al número de huevos en el nido, considerando dos zonas que, a priori, presentan diferente tipo de sustrato de nidificación. Para ello, durante un periodo de 40 días (16.05.201124.06-2011 la colonia de Ulia se visitó a diario. En promedio, se registró un tamaño de puesta de 3 huevos/nido, un número de huevos eclosionados de 3/nido y un porcentaje de eclosión de 88,4%. La fecha media de eclosión sucedió en la segunda quincena de Mayo. Asimismo, se registraron algunas diferencias entre las dos zonas en que se dividió la colonia (tamaño de puesta inferior y porcentaje de huevos eclosionados superior en una zona que presentó más roca y vegetación de mayor porte en relación a otra zona con menos rocas así como más hierba. Discutimos esto en un contexto de zonificación de la colonia de estudio en el marco de áreas de carácter óptimo o subóptimo en términos reproductivos.

Development of aero-space structural Ni3Al-based alloys for service at temperature above 1000 oC in air without protection coating

International Nuclear Information System (INIS)

Kablov, E.N.; Buntushkin, V.P.; Povarova, K.B.; Kasanskaya, N.K.

2001-01-01

The principles of alloying are developed for alloys based on the γ' phase Ni 3 Al and realized for the design of a high-temperature alloy VKNA-1V destined for a wide range of 'hot' GTE articles (e.g., flaps, nozzle vanes, turbine rotor blades, elements of flame tubes, and other complex thin-wall articles) produced by vacuum investment casting. Owing to a fortunate combination of the selected boron-free alloying system (Ni-AI-Cr-W-Mo-Zr-C), the presence of a ductile structure constituent such as nickel-based γ solid solution (∼10 wt%) and directed columnar or single crystal structure the alloy is characterized by high ductility at room (El=14-35 %), middle and high temperatures (El=18-31 % at 673-1473 K), by a melting temperature (solidus) as high as T m = 1613 K, a density of at most 7930 kg /m 3 , high short term and long term strength at temperatures 1273-1573 K (σ 100 =110 MPa at 1373 K). Alloy has a high oxidation resistance at temperatures up to 1573 K and is resistant to stress corrosion and general atmospheric corrosion. New VKNA-1V Ni 3 Al-based alloy with equiaxed grained, directional solidification (DS), or single crystal structures can be produced by conventional cast processes used for investment casting of nickel superalloys, including the process of high-gradient DS. Compared to nickel analogs, the alloy is relatively cheap and do not need in protective coating up to 1573 K in air. (author)

Updated ozone absorption cross section will reduce air quality compliance

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E. D. Sofen

2015-12-01

et al. (2015 as 1.8 % smaller than the accepted value (Hearn, 1961 used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

In-situ Electrodeposition of Highly Active Silver Catalyst on Carbon Fiber Papers as Binder Free Cathodes for Aluminum-air Battery

OpenAIRE

Hong, Qingshui; Lu, Huimin

2017-01-01

Carbon fiber papers supported Ag catalysts (Ag/CFP) with different coverage of electro-active site are prepared by electrochemical deposition and used as binder free cathodes in primary aluminum-air (Al-air) battery. Scanning Electron Microscopy and X-ray Diffraction studies are carried out to characterize the as-prepared Ag/CFP air cathodes. Oxygen reduction reaction (ORR) activities on these air cathodes in alkaline solutions are systematic studied. A newly designed aluminum-air cell is use...

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)

Afghanistan in the Balance: Air Politik

Science.gov (United States)

2010-06-01

of madrassas to build an ideological base and to access a steady pool of recruits echoes Mao Tse Tung’s emphasis on building up the political base...provide sanctuary to insurgents. During the Vietnam War, the insurgent Viet Minh used areas in Laos , Cambodia, and Thailand from which to stage...Force Base, AL: Air University Press, 2007). 19 Zedong Mao, Selected Works of Mao Tse -Tung, 1st ed., 5 vols. (Oxford; New York: Distributed throughout

Al2O3- BSST Based Chemical Sensors for Ammonia Gas Sensing

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L. A. Patil

2009-10-01

Full Text Available Gas sensing behaviour of pure and modified (Ba0.9Sr0.1(Sn0.5Ti0.5O3 (BSST thick films is reported in this article. The surface of the BSST thick film was modified by dipping it into aqueous solution of AlCl3, for different intervals of time. These films were then dried at 500 0C for 24 hours in air ambient for transformation of AlCl3 into Al2O3, for the evaporation of organic binders and also to improve the texture of the film. The gas response, selectivity, response and recovery time of the sensors were measured and presented. The role played by the aluminium species to improve the gas sensing performance of the sensors is discussed.

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

Commentary: Air-conditioning as a risk for increased use of healthservices

Energy Technology Data Exchange (ETDEWEB)

Mendell, Mark J.

2004-06-01

In this issue of the journal, Preziosi et al. [2004] report the first study to assess differences in the utilization of health care related to the presence of air-conditioning in office workplaces. Although the study was simple and cross-sectional, the data variables from questionnaires, and the findings subject to a variety of questions, the findings are striking enough to deserve clarification. The study used a large random national sample of French women assembled for another purpose (to study antioxidant nutrients and prevention of cancer and cardiovascular disease). Participants reported health services and health events in monthly questionnaires over 1 year, and in one questionnaire in the middle of that period also reported whether air-conditioning was in use at their workplace. Fifteen percent of participants reported air-conditioning at work. Analyses adjusting for age and smoking status of participants found increases in most outcomes assessed: use of specific kinds of physicians, sickness absence, and hospital stays. While the increases in odds ratios (OR) and 95% confidence intervals (CI) were statistically significant for only otorhinolaryngology [OR (95% CI) = 2.33 (1.35-4.04)] and sickness absence [1.70 (1.13-2.58)], other increases were notable--dermatology [1.6 (0.98-2.65)]; hospital stay [1.51 (0.92-2.45)], and pneumonology [2.10 (0.65-6.82)]. The least elevated outcomes were for general practice medicine [0.99 (0.65-1.48)] and global medical visits [1.18 (0.67-2.07)]. [Preziosi et al., 2004 ,(Table 2)] Odds ratios for relatively common health outcomes often lie farther from the null than the risk ratios most useful for quantifying the increase in risk. Risk ratios, or prevalence ratios (PRs, the equivalent measure of effect for cross-sectional data), have seldom been used because of the convenience and availability of logistic regression models that estimate odds ratios. With baseline prevalences ranging up to 85.7% in the data from Preziosi et

Conocer el entorno experimentando con el sonido. Una propuesta de innovación en el aula de infantil

OpenAIRE

Melero Paredes, Cristina

2017-01-01

La experimentación es la que constituye una estrategia fundamental para facilitar la aprehensión del medio por parte del niño o la niña al tiempo que se revela un elemento clave para otorgar a éste o ésta el protagonismo en el proceso de enseñanza-aprendizaje. A través de la experimentación, en este trabajo se va a acercar a los niños y niñas al entorno para que puedan experimentar a través del sonido y se den cuenta que es muy importante. Con la puesta en práctica en un aula con un grupo de ...

Improvement of Aluminum-Air Battery Performances by the Application of Flax Straw Extract.

Science.gov (United States)

Grishina, Ekaterina; Gelman, Danny; Belopukhov, Sergey; Starosvetsky, David; Groysman, Alec; Ein-Eli, Yair

2016-08-23

The effect of a flax straw extract on Al corrosion inhibition in a strong alkaline solution was studied by using electrochemical measurements, weight-loss analysis, SEM, and FTIR spectroscopy. Flax straw extract added (3 vol %) to the 5 m KOH solution to act as a mixed-type Al corrosion inhibitor. The electrochemistry of Al in the presence of a flax straw extract in the alkaline solution, the effect of the extract on the Al morphology and surface films formed, and the corrosion inhibition mechanism are discussed. Finally, the Al-air battery discharge capacity recorded from a cell that used the flax straw extract in the alkaline electrolyte is substantially higher than that with only a pure alkaline electrolyte. This improved sustainability of the Al anode is attributed to Al corrosion inhibition and, consequently, to hydrogen evolution suppression. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Air Force Journal of Logistics, Volume 32, Number 2, Summer 2008

Science.gov (United States)

2008-01-01

will be edited in accordance with if e-mail is not available. They should be sent to the Air Force Journal of Logistics Manual for Style, the...following address. First Edition and the Gregg Reference Manual . r- Air Force Journal of Logistics 501 Ward Street, Maxwell AFB, Gunter Annex AL 36114-3236...future Ai Foc Loitc Manaemen Agenc htp /wwa I ma hq.a.miI 72 ~~Ai Foc Jora of Loitc It is impossible to discuss the total not mission capable

Shahat et al., Afr J Tradit Complement Altern Med. (2017) 14(2):161 ...

African Journals Online (AJOL)

Sayed

The obtained dry extract was weighed and the percentage yield was expressed in terms of air dried weight of plant materials. Material for Antimicrobials. The bacterial, fungal and yeast strains were personally obtained from the microbiology Lab, Botany Dept.,. Fac. of Sci. (Al- Azhar Univ. Assiut, Assiut Univ. and Minia Univ.).

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.

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

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

The crystallization and physical properties of Al-doped ZnO nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Chen, K.J. [Institute of Microelectronics and Department of Electrical Engineering, Center for Micro/Nano Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Fang, T.H. [Institute of Mechanical and Electromechanical Engineering, National Formosa University, Yunlin 632, Taiwan (China); Hung, F.Y. [Institute of Nanotechnology and Microsystems Engineering, Center for Micro/Nano Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China)], E-mail: fyhung@mail.mse.ncku.edu.tw; Ji, L.W. [Institute of Mechanical and Electromechanical Engineering, National Formosa University, Yunlin 632, Taiwan (China); Chang, S.J.; Young, S.J. [Institute of Microelectronics and Department of Electrical Engineering, Center for Micro/Nano Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Hsiao, Y.J. [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China)

2008-07-15

Un-doped Al (0-9 at.%) nanoparticles and doped ZnO powders were prepared by the sol-gel method. The nanoparticles were heated at 700-800 deg. C for 1 h in air and then analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectra and photoluminescence (PL). The results of un-doped (ZnO) and Al-doped ZnO (AZO) nanoparticles were also compared to investigate the structural characteristics and physical properties. XRD patterns of AZO powders were similar to those of ZnO powders, indicating that micro-Al ions were substituted for Zn atoms and there were no variations in the structure of the ZnO nanoparticles. From the XRD and SEM data, the grain size of the AZO nanoparticles increased from 34.41 to 40.14 nm when the annealing temperature was increased. The Raman intensity of the AZO nanoparticles (Al = 5 at.%) increased when the annealing temperature was increased. Increasing the degree of crystalline not only reduced the residual stress, but also improved the physical properties of the nanoparticles.

The crystallization and physical properties of Al-doped ZnO nanoparticles

International Nuclear Information System (INIS)

Chen, K.J.; Fang, T.H.; Hung, F.Y.; Ji, L.W.; Chang, S.J.; Young, S.J.; Hsiao, Y.J.

2008-01-01

Un-doped Al (0-9 at.%) nanoparticles and doped ZnO powders were prepared by the sol-gel method. The nanoparticles were heated at 700-800 deg. C for 1 h in air and then analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectra and photoluminescence (PL). The results of un-doped (ZnO) and Al-doped ZnO (AZO) nanoparticles were also compared to investigate the structural characteristics and physical properties. XRD patterns of AZO powders were similar to those of ZnO powders, indicating that micro-Al ions were substituted for Zn atoms and there were no variations in the structure of the ZnO nanoparticles. From the XRD and SEM data, the grain size of the AZO nanoparticles increased from 34.41 to 40.14 nm when the annealing temperature was increased. The Raman intensity of the AZO nanoparticles (Al = 5 at.%) increased when the annealing temperature was increased. Increasing the degree of crystalline not only reduced the residual stress, but also improved the physical properties of the nanoparticles

La Virtualización de la afectividad

OpenAIRE

Alfama, Eva

2005-01-01

El trabajo inmaterial, al amparo de las sociedades postfordistas actuales donde la vida ha sido puesta a trabajar, se desarrolla operando sobre una constelación de intangibles como son el conocimiento, la información, los saberes, la comunicación o los afectos. Ocio y negocio, tiempo de descanso y de trabajo, relaciones personales y profesionales se entremezclan cada vez más hasta con-fundirse en un solo momento productivo. Así, el universo de lo afectivo, mientras antes se quedaba relegado a...

Una revisión del proceso de la logística inversa y su relación con la logística verde

OpenAIRE

Vicente Reyes De León; Daniel Zavala Rio; Jorge Gálvez Choy

2008-01-01

A nivel mundial, al menos en los países industrializados, el desarrollo de la práctica de Logística Inversa se presenta como una ventaja competitiva significante. Se identifican tres motivos bien diferenciados que promueven el desarrollo y puesta en marcha de esta práctica, y estos son los legales, los sociales y los económicos. Cualquier empresa que planee implementar la Logística Inversa dentro de sus estrategias a mediano y largo plazo, debe identificar con claridad sus alcances, limitacio...

MK-2.0: Secretos a voces del social-media

OpenAIRE

María Aránzazu Sulé Alonso; Javier Prieto García

2010-01-01

Las redes sociales son un fenómeno emergente al que cada día se suman nuevos adeptos convirtiéndose en un sector exitoso que los expertos en marketing digital tienen que aprovechar. Esta investigación evidencia que la multidisciplinariedad entre ambas puede tener efectos muy beneficiosos y que su puesta en práctica es ya una realidad. Pepsi, Starbucks, Avon, Adidas, infinidad de marcas de reconocido prestigio internacional han apostado muy fuerte por estos nuevos canales de actuación obtenien...

La recepción crítica del estreno de Himmelweg, de Juan Mayorga, en Madrid

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Manuel Aznar Soler

2016-12-01

Full Text Available Este trabajo presenta un recorrido por la recepción crítica de Himmelweg, obra del autor español Juan Mayorga que versa sobre el Holocausto judío. Tras su estreno en Málaga el año anterior, Himmelweg llegaba al teatro María Guerrero de Madrid en 2004. Tanto el propio texto como la puesta en escena despertaron opiniones encontradas en las críticas teatrales de la prensa madrileña. Este trabajo recoge esas posturas.

Air Sparging Versus Gas Saturated Water Injection for Remediation of Volatile LNAPL in the Borden Aquifer

Science.gov (United States)

Barker, J.; Nelson, L.; Doughty, C.; Thomson, N.; Lambert, J.

2009-05-01

In the shallow, rather homogeneous, unconfined Borden sand aquifer, field trials of air sparging (Tomlinson et al., 2003) and pulsed air sparging (Lambert et al., 2009) have been conducted, the latter to remediate a residual gasoline source emplaced below the water table. As well, a supersaturated (with CO2) water injection (SWI) technology, using the inVentures inFusion system, has been trialed in two phases: 1. in the uncontaminated sand aquifer to evaluate the radius of influence, extent of lateral gas movement and gas saturation below the water table, and 2. in a sheet pile cell in the Borden aquifer to evaluate the recovery of volatile hydrocarbon components (pentane and hexane) of an LNAPL emplaced below the water table (Nelson et al., 2008). The SWI injects water supersaturated with CO2. The supersaturated injected water moves laterally away from the sparge point, releasing CO2 over a wider area than does gas sparging from a single well screen. This presentation compares these two techniques in terms of their potential for remediating volatile NAPL components occurring below the water table in a rather homogeneous sand aquifer. Air sparging created a significantly greater air saturation in the vicinity of the sparge well than did the CO2 system (60 percent versus 16 percent) in the uncontaminated Borden aquifer. However, SWI pushed water, still supersaturated with CO2, up to about 2.5 m from the injection well. This would seem to provide a considerable advantage over air sparging from a point, in that gas bubbles are generated at a much larger radius from the point of injection with SWI and so should involve additional gas pathways through a residual NAPL. Overall, air sparging created a greater area of influence, defined by measurable air saturation in the aquifer, but air sparging also injected about 12 times more gas than was injected in the SWI trials. The pulsed air sparging at Borden (Lambert et al.) removed about 20 percent (4.6 kg) of gasoline

Innovación y ruptura en la métrica de la poesía en al-Maqāmāt al-Luzūmiyya de al-Saraqusṭī (s. VI/XII

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Ferrando, Ignacio

2016-06-01

Full Text Available Al-Maqāmāt al-Luzūmiyya, a collection of 50 picaresque-like stories couched in rhymed prose by Abū l-Ṭāhir al-Saraqusṭī in al-Andalus in the VI/XIIth century, were considered by Western scholars, up until the eighties of XXth century, as highly rhetorical pieces with a negligible and irrelevant content. However, some contemporary scholars argued that they contain some degree of social and political criticism, as they constitute a fictional domain in which subversion and irony play a fundamental role. In this paper, we cast some light on the particular use of metrical patterns in Al-Maqāmāt al-Luzūmiyya, which should be considered another subversion field: a poetical rhythm that avoids the most usual Arabic metrical patterns, contributing to provide the maqāma a flavor of the countergenre.Al-Maqāmāt al-Luzūmiyya, la colección de 50 relatos de corte picaresco escritos en una exigente prosa rimada por Abū l-Ṭāhir al-Saraqusṭī en al-Andalus en el siglo VI/XII, han sido consideradas por los críticos occidentales como piezas de alta retórica y de virtuosismo lingüístico en las que el contenido es prácticamente irrelevante. Sin embargo, a partir de los años 80 del siglo pasado, algunos investigadores han tratado de incidir en el hecho de que esta obra contiene cierto grado de crítica social y política, puesto que constituye un espacio ficticio en el que la subversión y la ironía desempeñan un papel fundamental. En este trabajo vamos a tratar de arrojar luz sobre el uso particular de los esquemas métricos por parte de al-Saraqusṭī, tratando de mostrar que los metros constituyen otro más de los ámbitos de subversión tan caros al autor. De hecho, el uso de ritmos “invertidos” o contrarios a los más habituales de la poesía clásica contribuye a darle a la maqāma ese aire de anti género que la puebla.

Determination of the reference air kerma rate for 192Ir brachytherapy sources and the related uncertainty

International Nuclear Information System (INIS)

Dijk, Eduard van; Kolkman-Deurloo, Inger-Karine K.; Damen, Patricia M. G.

2004-01-01

Different methods exist to determine the air kerma calibration factor of an ionization chamber for the spectrum of a 192 Ir high-dose-rate (HDR) or pulsed-dose-rate (PDR) source. An analysis of two methods to obtain such a calibration factor was performed: (i) the method recommended by [Goetsch et al., Med. Phys. 18, 462-467 (1991)] and (ii) the method employed by the Dutch national standards institute NMi [Petersen et al., Report S-EI-94.01 (NMi, Delft, The Netherlands, 1994)]. This analysis showed a systematic difference on the order of 1% in the determination of the strength of 192 Ir HDR and PDR sources depending on the method used for determining the air kerma calibration factor. The definitive significance of the difference between these methods can only be addressed after performing an accurate analysis of the associated uncertainties. For an NE 2561 (or equivalent) ionization chamber and an in-air jig, a typical uncertainty budget of 0.94% was found with the NMi method. The largest contribution in the type-B uncertainty is the uncertainty in the air kerma calibration factor for isotope i, N k i , as determined by the primary or secondary standards laboratories. This uncertainty is dominated by the uncertainties in the physical constants for the average mass-energy absorption coefficient ratio and the stopping power ratios. This means that it is not foreseeable that the standards laboratories can decrease the uncertainty in the air kerma calibration factors for ionization chambers in the short term. When the results of the determination of the 192 Ir reference air kerma rates in, e.g., different institutes are compared, the uncertainties in the physical constants are the same. To compare the applied techniques, the ratio of the results can be judged by leaving out the uncertainties due to these physical constants. In that case an uncertainty budget of 0.40% (coverage factor=2) should be taken into account. Due to the differences in approach between the

Some observations on the high temperature oxidation behaviour of plasma sprayed Ni3Al coatings

International Nuclear Information System (INIS)

Singh, H.; Prakash, S.; Puri, D.

2007-01-01

High temperature oxidation resistance of the superalloys can be greatly enhanced by plasma sprayed coatings and this is a growing industry of considerable economic importance. The purpose of these coatings is to form long-lasting oxidation protective scales. In the current investigation, Ni 3 Al powder was prepared by mechanical mixing of pure nickel and aluminium powders in a ball mill. Subsequently Ni 3 Al powder was deposited on three Ni-base superalloys: Superni 600, Superni 601 and Superni 718 and, one Fe-base superalloy, Superfer 800H by shrouded plasma spray process. Oxidation studies were conducted on the coated superalloys in air at 900 deg. C under cyclic conditions for 50 cycles. Each cycle consisted of 1 h heating followed by 20 min of cooling in air. The thermogravimetric technique was used to approximate the kinetics of oxidation. All the coated superalloys nearly followed parabolic rate law of oxidation. X-ray diffraction, SEM/EDAX and EPMA techniques were used to analyse the oxidation products. The Ni 3 Al coating was found to be successful in maintaining its adherence to the superalloy substrates in all the cases. The oxide scales formed on the oxidised coated superalloys were found to be intact and spallation-free. XRD analysis revealed the presence of phases like NiO, Al 2 O 3 and NiAl 2 O 4 in the oxide scales, which are reported as protective oxides against high temperature oxidation. The XRD results were further supported by SEM/EDAX and EPMA

Effect of Surface Treatment on Shear Bond Strength between Resin Cement and Ce-TZP/Al2O3

Directory of Open Access Journals (Sweden)

Jong-Eun Kim

2016-01-01

Full Text Available Purpose. Although several studies evaluating the mechanical properties of Ce-TZP/Al2O3 have been published, to date, no study has been published investigating the bonding protocol between Ce-TZP/Al2O3 and resin cement. The aim of this study was to evaluate the shear bond strength to air-abraded Ce-TZP/Al2O3 when primers and two different cement types were used. Materials and Methods. Two types of zirconia (Y-TZP and Ce-TZP/Al2O3 specimens were further divided into four subgroups according to primer application and the cement used. Shear bond strength was measured after water storage for 3 days or 5,000 times thermocycling for artificial aging. Results. The Y-TZP block showed significantly higher shear bond strength than the Ce-TZP/Al2O3 block generally. Primer application promoted high bond strength and less effect on bond strength reduction after thermocycling, regardless of the type of cement, zirconia block, or aging time. Conclusions. Depending on the type of the primer or resin cement used after air-abrasion, different wettability of the zirconia surface can be observed. Application of primer affected the values of shear bond strength after the thermocycling procedure. In the case of using the same bonding protocol, Y-TZP could obtain significantly higher bond strength compared with Ce-TZP/Al2O3.

AIR SEPARATION BY PRESSURE SWING ADSORPTION USING SUPERIOR ADSORBENTS

Energy Technology Data Exchange (ETDEWEB)

Ralph T. Yang

2001-08-31

Li-X zeolite (Si/Al = 1.0) is currently the best sorbent for use in the separation of air by adsorption processes. In particular, pressure swing adsorption (PSA) using zeolite sorbents is being increasingly used for air separation. Silver is also known to strongly affect the adsorptive properties of zeolites; and it is known that thermal vacuum dehydration of silver zeolites leads to the formation of silver clusters within the zeolite. In this work we have synthesized type X zeolites containing Ag and also varying mixtures of Li and Ag. In this project, we developed the Ag-containing zeolite as the best sorbent for air separation. We have also studied Co-ligand compounds as oxygen-selective sorbents. Syntheses, structural characterization and adsorption properties have been performed on all sorbents. The results are described in detail in 5 chapters.

Effect of aluminium concentration and boron dopant on environmental embrittlement in FeAl aluminides

International Nuclear Information System (INIS)

Liu, C.T.; George, E.P.

1991-01-01

This paper reports on the room-temperature tensile properties of FeAl aluminides determined as functions of aluminum concentration (35 to 43 at. % Al), test environment, and surface (oil) coating. The two lower aluminum alloys containing 35 and 36.5% Al are prone to severe environmental embrittlement, while the two higher aluminum alloys with 40 and 43% Al are much less sensitive to change in test environment and surface coating. The reason for the different behavior is that the grain boundaries are intrinsically weak in the higher aluminum alloys, and these weak boundaries dominate the low ductility and brittle fracture behavior of the 40 and 43% Al alloys. When boron is added to the 40% Al alloy as a grain-boundary strengthener, the environmental effect becomes prominent. In this case, the tensile ductility of the boron-doped alloy, just like that of the lower aluminum alloys, can be dramatically improved by control of test environment (e.g. dry oxygen vs air). Strong segregation of boron to the grain boundaries, with a segregation factor of 43, was revealed by Auger analyses

Modeling the effect of water vapor on the interfacial behavior of high-temperature air in contact with Fe20Cr surfaces

International Nuclear Information System (INIS)

Chialvo, Ariel A.; Brady, Michael P.; Keiser, James R.; Cole, David R.

2011-01-01

Highlights: → Atomistic view of the contrasting interfacial behavior between high-temperature dry- and wet-air in contact with stainless steels. → H 2 O preferentially adsorbs and displaces oxygen at the metal-fluid interface. → Findings are consistent with Ehlers et al.'s proposed competitive adsorption mechanism for the interpretation of the breakaway oxidation. → Significant impact of the inhomogeneous density distribution between the interfacial- and bulk-environments on the fluid transport. -- This work uses molecular dynamics simulation to provide an atomistic view of the contrasting interfacial behavior between high-temperature dry air and wet (10-40 vol.% water) air in contact with stainless steels. A key finding was that H 2 O preferentially adsorbs and displaces oxygen at the metal-fluid interface. We also discuss how these findings are consistent with Ehlers et al. proposed competitive adsorption mechanism for the interpretation of the breakaway oxidation, and highlight their impact on other properties.

Air pollution in Thailand using nuclear-related analytical techniques

International Nuclear Information System (INIS)

Leelhaphunt, N.; Chueinta, W.

1994-01-01

The methods of neutron activation, both instrumental and radiochemical, and atomic absorption spectrophotometry are used in a study of the concentrations of Al, As, Br, Cd, Cl, Co, Cr, Cu, Fe, Hg, Mn, Sb, Sc, Se, Si, V, Zn and Pb in airborne particulate matter collected from 7 permanent and 9 temporary air quality monitoring stations. The location of the stations are urban residential, suburban residential, mixed (commercial and residential), commercial and industrial areas and near major roads in Bangkok Metropolitan areas. Air sampling is performed once a month for 24 hours continuously using the high volume air sampler (GMW 2000 H) and for 5, 10, and 15 days continuously using an Anderson Air Sampler (SIBATA AN-200). The elements As, Cd and Cu are determined destructively using ion exchange chromatography while Hg and Se are determined by the dry combustion technique. The determination of Pb was done by atomic absorption spectrophotometry. The results of Pb concentrations in airborne particulate matters, collected during 1987 to 1991, were reported by the Office of the National Environment Board. Levels of Pb content were found to be lower than the National Ambient Air Quality Standards. (author). 3 refs, 4 tabs

El agotamiento del derecho a la luz del derecho comunitario. Unión Europea y Comunidad Andina

Directory of Open Access Journals (Sweden)

Diana Marín

2012-11-01

Full Text Available La propiedad intelectual otorga a sus titulares una serie de facultades exclusivas y excluyentes denominadas técnicamente ius prohibendi; se trata de una serie de derechos subjetivos que el ordenamiento jurídico reconoce al creador de una obra, inventor de una nueva tecnología o utilidad, diseñador y/o titular de un signo distintivo, y en general una persona natural o jurídica que a partir de su ingenio aporta nuevas creaciones –originales– de cualquier índole a la sociedad. Dichas facultades, al igual que cualquier tipo de derecho, no son ni pueden ser consideradas absolutas, razón por la cual el mismo ordenamiento jurídico limita el ejercicio del ius prohibendi. Entre tales limitaciones se encuentra el agotamiento del derecho, que supone que una vez se ha realizado una primera puesta en el mercado del producto que incorpora la propiedad intelectual por el titular de los derechos o un tercero autorizado por él, el derecho exclusivo de distribución que recae sobre ese bien se extingue, razón por la cual cualquier agente económico podrá realizar actos de comercio sobre ese mismo objeto, y dará lugar a las denominadas importaciones paralelas. El agotamiento del derecho presenta diferentes matices, en donde el alcance de la extinción del derecho de distribución puede ser nacional (se restringe al país donde se realizó la puesta en el mercado, regional (se restringe a una comunidad de países o internacional (abarca todo el universo.

Better Visualisation of Air-borne Laser Scanning for geomorphological and archaeological interpretation

DEFF Research Database (Denmark)

Ljungberg, Thomas; Scott, D; Kristiansen, Søren Munch

Digital elevation models derived from high-precision Air-borne Laser Scanning (ALS or LiDAR) point clouds are becoming increasingly available throughout the world. These elevation models presents a very valuable tool for locating and interpreting geomorphological as well as archaeological features...

Enhanced luminescence in SrMgAl(x)O(17±δ):yMn4+ composite phosphors.

Science.gov (United States)

Cao, Renping; Sharafudeen, Kaniyarakkal N; Qiu, Jianrong

2014-01-03

Red-emitting SrMgAlxO17±δ:yMn(4+) composite phosphors (x=10-100; y=0.05-4.0 mol%) are synthesized by solid-state reaction method in air. Addition of Al2O3 leads to the formation of two concomitant phases, i.e., SrMgAl10O17 and Al2O3 phases in the composite phosphor. Red emission from Mn(4+) ions in the composite phosphors is greatly enhanced due to multiple scattering and absorption of excitation light between SrMgAl10O17 and Al2O3 phases. SrMgAlxO17±δ:yMn(4+) composite phosphors would be a promising candidate as red phosphor in the application of a 397 nm near UV-based W-LED. Copyright © 2013 Elsevier B.V. All rights reserved.

Air pollution holiday effect in metropolitan Kaohsiung

Science.gov (United States)

Tan, P.; Chen, P. Y.

2014-12-01

Different from Taipei, the metropolitan Kaohsiung which is a coastal and industrial city has the major pollution sources from stationary sources such as coal-fired power plants, petrochemical facilities and steel plants, rather than mobile sources. This study was an attempt to conduct a comprehensive and systematical examination of the holiday effect, defined as the difference in air pollutant concentrations between holiday and non-holiday periods, over the Kaohsiung metropolitan area. We documented evidence of a "holiday effect", where concentrations of NOx, CO, NMHC, SO2 and PM10 were significantly different between holidays and non-holidays, in the Kaohsiung metropolitan area from daily surface measurements of seven air quality monitoring stations of the Taiwan Environmental Protection Administration during the Chinese New Year (CNY) and non-Chinese New Year (NCNY) periods of 1994-2010. Concentrations of the five pollutants were lower in the CNY than in the NCNY period, however, that of O3 was higher in the CNY than in the NCNY period and had no holiday effect. The exclusion of the bad air quality day (PSI > 100) and the Lantern Festival Day showed no significant effects on the holiday effects of air pollutants. Ship transportation data of Kaohsiung Harbor Bureau showed a statistically significant difference in the CNY and NCNY period. This difference was consistent with those found in air pollutant concentrations of some industrial and general stations in coastal areas, implying the possible impact of traffic activity on the air quality of coastal areas. Holiday effects of air pollutants over the Taipei metropolitan area by Tan et al. (2009) are also compared.

Trends in motor neuron disease: association with latitude and air lead levels in Spain.

Science.gov (United States)

Santurtún, Ana; Villar, Alejandro; Delgado-Alvarado, Manuel; Riancho, Javier

2016-08-01

Motor neuron diseases (MND) are a group of disorders characterized by motor neuron degeneration. Among them, amyotrophic lateral sclerosis (ALS) is by far the most common in adulthood. This paper assesses the trend and geographical pattern in MND incidence in Spain and the possible air lead levels effect on this pathology. To confirm this concept, we performed a retrospective analysis of the deaths due to MND in Spain during 2000 and 2013, determined the geographical differences, and explored the relationship between MND and the air levels of lead. Overall, between 2000 and 2013, 11,355 people died in Spain because of MND. Disease mortality significantly increased in recent years (2007-2013) when compared with the first time of the period. Spearman's rank correlation coefficient also showed a statistically significant positive trend (CC = 0.824, p = 0.0002). Among people over 65 years, mortality rates were higher in Northern provinces. Moreover, we found a significant association of MND mortality with higher air lead levels (CC = 0.457, p = 0.01). Our study confirms that MND mortality is increasing in Spain, with a significant latitude gradient, which suggests an important role of environmental exposures. This ecological study suggests that air lead levels may be implicated in ALS pathogenesis.

Bonding of composite resins to PEEK: the influence of adhesive systems and air-abrasion parameters.

Science.gov (United States)

Stawarczyk, Bogna; Taufall, Simon; Roos, Malgorzata; Schmidlin, Patrick R; Lümkemann, Nina

2018-03-01

The objective of the study was to investigate the tensile bond strength (TBS) to polyaryletheretherketone (PEEK) after different pretreatment and conditioning methods. Four hundred PEEK specimens were fabricated and allocated to the following air-abrasion methods (n 1  = 80/pretreatment): (i) 50 μm Al 2 O 3 (0.05 MPa); (ii) 50 μm Al 2 O 3 (0.35 MPa); (iii) 110 μm Al 2 O 3 (0.05 MPa); (iv) 110 μm Al 2 O 3 (0.35 MPa); and (v) Rocatec 110 μm (0.28 MPa). These pretreatments were combined with the following conditioning methods (n 2  = 20/pretreatment/conditioning): (a) visio.link (VL); (b) Monobond Plus/Heliobond (MH); (c) Scotchbond Universal (SU); and (d) dialog bonding fluid (DB). After veneering of all specimens with dialog occlusal and aging (28 days H 2 O, 37 °C + 20,000 thermal cycles, 5/55 °C), TBS was measured. Data was analysed using Kaplan-Meier survival analysis with Breslow-Gehan test and Cox-regressions. The major impact on TBS showed the conditioning, followed by the air-abrasion-pressure, while the grain size of the air-abrasion powder did not show any effect. Specimens air-abraded at 0.35 MPa showed the highest survival rates. However, within VL groups, this observation was not statistically significant. Within MH groups, pretreatment using 110 μm Al 2 O 3 and 0.05 MPa resulted in higher survival rates compared to groups treated with 50 and 110 μm Al 2 O 3 using a pressure of 0.35 MPa. The use of VL showed the highest survival rates between the adhesive systems and the TBS values higher than 25 MPa independent of the pretreatment method. As an exception, only VL showed significantly higher survival rates when compared to MH. The adequate choice of the adhesive system and higher pressures improved the TBS between PEEK and veneering resin composite. The particle size had no major impact. According to this study, best veneering of PEEK with dialog occlusal can be achieved by conditioning with visio.link in combination with

New species of ice nucleating fungi in soil and air

Science.gov (United States)

Fröhlich-Nowoisky, Janine; Hill, Thomas C. J.; Pummer, Bernhard G.; Franc, Gray D.; Pöschl, Ulrich

2014-05-01

Primary biological aerosol particles (PBAP) are ubiquitous in the atmosphere (1,2). Several types of PBAP have been identified as ice nuclei (IN) that can initiate the formation of ice at relatively high temperatures (3, 4). The best-known biological IN are common plant-associated bacteria. The IN activity of these bacteria is due to a surface protein on the outer cell membrane that catalyses ice formation, for which the corresponding gene has been identified and detected by DNA analysis (3). Fungal spores or hyphae can also act as IN, but the biological structures responsible for their IN activity have not yet been elucidated. Furthermore, the abundance, diversity, sources, seasonality, properties, and effects of fungal IN in the atmosphere have neither been characterized nor quantified. Recent studies have shown that airborne fungi are highly diverse (1), and that atmospheric transport leads to efficient exchange of species among different ecosystems (5, 6). The results presented in Fröhlich-Nowoisky et al. 2012 (7) clearly demonstrate the presence of geographic boundaries in the global distribution of microbial taxa in air, and indicate that regional differences may be important for the effects of microorganisms on climate and public health. DNA analyses of aerosol samples collected during rain events showed higher diversity and frequency of occurrence for fungi belonging to the Sordariomycetes, than samples that were collected under dry conditions (8). Sordariomycetes is the class that comprises known ice nucleation active species (Fusarium spp.). By determination of freezing ability of fungal colonies isolated from air samples two species of ice nucleation active fungi that were not previously known as biological ice nucleators were found. By DNA-analysis they were identified as Isaria farinosa and Acremonium implicatum. Both fungi belong to the phylum Ascomycota, produce fluorescent spores in the range of 1-4 µm in diameter, and induced freezing at -4 and

Oxidation and corrosion studies of Al-implanted stainless steel AISI 321 using nuclear reaction and electrochemical techniques

International Nuclear Information System (INIS)

Noli, F.; Misaelides, P.; Spathis, P.; Pilakouta, M.; Baumann, H.

1992-01-01

The oxidation of Al-implanted (implantation energy 40 keV, dose 10 16 -10 17 Al ions/cm 2 ) AISI 321 stainless steel samples in air has been studied at temperatures between 450 and 650degC using the 16 O(d,p) 17 O nuclear reaction. The determination of the distribution of the implanted Al atoms has been performed using the resonance at 992 keV of the 27 Al(p,γ) 28 Si nuclear reaction. The determined oxygen profiles indicate that the implantation of 5x10 16 and 10 17 Al ions/cm 2 leads to an improvement of the oxidation resistance of the studied steel samples. The passivation/corrosion behaviour of the Al-implanted steel samples in 0.5M aqueous sulphuric acid solution has also been investigated electrochemically using potentiodynamic and cyclovoltammetric techniques. The passivation potential values and the repassivation moving to more positive values indicate an improvement of the corrosion resistance of the Al-implanted steel samples. (orig.)

Diffusion and Bonding Mechanism of Protective γ-Al2O3 on FeCrAl Foil for Metallic Three-Way Catalytic Converter

Directory of Open Access Journals (Sweden)

Feriyanto Dafit

2017-01-01

Full Text Available High pollutant level contributed by mobile sources/land transportation that become main problems for the human health. Improving exhaust emission system by improving catalytic converter properties is one of the most effective way to produce healthy air in our environment. It is conducted by two methods i.e. ultrasonic during electroplating (UBDEL and electroplating process (EL which are not fully investigated yet as catalytic converter coating process. UBDEL is conducted using sulphamate types electrolyte solution, Frequency of 35 kHz, current of 1.28A, Voltage of 12 V, and various time of 15, 30, 45, 60 and 75 minutes. Meanwhile El method is conducted using parameters of current of 1.28A, Voltage of 12 V, stirrer speed of 60 rpm and various time of 15, 30, 45, 60 and 75 minutes. Fully γ-Al2O3 bonding to the FeCrAl substrate is shown by UBDEL 75 minutes samples proved by SEM images and Ra and Rq are 4.01 μm and 5.64 μm, respectively. Ni present on the FeCrAl substrate as other protective layer generated by Ni electroplating process that will improve thermal stability of FeCrAl at high temperature of 1000 °C. From the results, can summarized that UBDEL technique is promoted as an effective catalytic converter coating technique.

Microstructural development in a rapidly solidified Al-Fe-V-Si alloy

International Nuclear Information System (INIS)

Park, W.J.; Baek, E.R.; Lee, Sunghak; Kim, N.J.

1991-01-01

TEM is used to investigate microstructural development in a rapidly solidified Al-Fe-V-Si alloy. The as-cast microstructure of a rapidly solidified Al-Fe-V-Si alloy was found to vary depending on casting conditions and also through the thickness of ribbon. For completely Zone A ribbon, intercellular phase consists of a microquasi-crystalline phase, while for the Zone A and Zone B mixed ribbon, it consists of a silicide phase. In either case, formation of globular particles of a cluster microquasi-crystalline phase is observed near the air side of the ribbon. Annealing study shows significant differences in the final microstructure depending on the initial status of the ribbon. Completely Zone A ribbon, whose microstructure is composed of a microquasi-crystalline phase, results in a very coarse microstructure after annealing as compared to the Zone A and Zone B mixed ribbon. This result has important implications for the development of high-performance elevated-temperature Al alloys. 12 refs

De la autogestión al modelo de negocios 360º. La producción musical independiente en vivo en la ciudad de Buenos Aires

Directory of Open Access Journals (Sweden)

Guillermo Martín Quiña

2014-01-01

Full Text Available La música independiente ha tendido a ser indagada casi exclusivamente en su dimensión discográfica, pese a la creciente articulación de negocios editoriales y de espectáculos en vivo mediante los llamados contratos 360º y al crecimiento constante de la actividad musical en vivo. El presente trabajo explora, desde una perspectiva sociológica que recupera los aportes de la economía política, las transformaciones concretas que en este nuevo contexto tienen lugar sobre la producción musical independiente en vivo en la ciudad de Buenos Aires. Siendo ésta poco reconocida como una industria, nuestro objetivo es comprender el vínculo entre la producción musical independiente y el proceso de acumulación de capital así como despertar la atención sobre la dinámica de funcionamiento de la música en vivo.

Accuracy of Prediction Equations to Assess Percentage of Body Fat in Children and Adolescents with Down Syndrome Compared to Air Displacement Plethysmography

Science.gov (United States)

Gonzalez-Aguero, A.; Vicente-Rodriguez, G.; Ara, I.; Moreno, L. A.; Casajus, J. A.

2011-01-01

To determine the accuracy of the published percentage body fat (%BF) prediction equations (Durnin et al., Johnston et al., Brook and Slaughter et al.) from skinfold thickness compared to air displacement plethysmography (ADP) in children and adolescents with Down syndrome (DS). Twenty-eight children and adolescents with DS (10-20 years old; 12…

Oxidation properties of laser clad Nb-Al alloys

International Nuclear Information System (INIS)

Tewari, S.K.; Mazumder, J.

1992-01-01

This paper reports on laser cladding parameters for non-equilibrium synthesis for several ternary and complex Nb-Al base alloys containing Ti, Cr, Si, Ni, B and C that have been established. Phase transformations occurring below 1500 degrees C have been determined using differential thermal analysis. Ductility of the clads is qualitatively evaluated from the extent of cracking around the microhardness indentations. Oxidation resistance of the clads in flowing air is measured at 800 degrees C, 1200 degrees C and 1400 degrees C and parabolic rate constants are calculated. Microstructure of the clads is studied using optical and scanning electron microscopes. X-ray diffraction and EDX techniques are used for identification of the oxides formed and the phases formed in as clad material. Oxide morphology is studied using SEM. Effect of alloying additions on the ductility and oxidation resistance of the laser clad Nb-Al alloys is discussed. The results are compared with those reported in literature for similar alloys produced by conventional processing methods

Characteristics of Cu–Al2O3 composites of various starting particle size obtained by high-energy milling

Directory of Open Access Journals (Sweden)

VIŠESLAVA RAJKOVIĆ

2009-05-01

Full Text Available The powder Cu– Al2O3 composites were produced by high-energy milling. Various combinations of particle size and mixtures and approximately constant amount of Al2O3 were used as the starting materials. These powders were separately milled in air for up to 20 h in a planetary ball mill. The copper matrix was reinforced by internal oxidation and mechanical alloying. During the milling, internal oxidation of pre-alloyed Cu-2 mass %-Al powder generated 3.7 mass % Al2O3 nano-sized particles finely dispersed in the copper matrix. The effect of different size of the starting copper and Al2O3 powder particles on the lattice parameter, lattice distortion and grain size, as well as on the size, morphology and microstructure of the Cu– Al2O3 composite powder particles was studied.

High-temperature behavior of oxide dispersion strengthening CoNiCrAlY

Energy Technology Data Exchange (ETDEWEB)

Unocic, Kinga A. [ORNL; Bergholz, Jan [Forschungszentrum Jülich GmbH; Huang, T [Institute for Energy and Climate Research, IEK-2, Forschungszentrum Jülich GmbH; Naumenko, Dymtro [Forschungszentrum Julich GmbH (Julich Research Centre), Germany; Pint, Bruce A. [ORNL; Vaßen, Robert [Forschungszentrum Julich, Germany; Quadakkers, Willem Joseph [Forschungszentrum Julich, Germany

2017-11-01

To fabricate oxide dispersion strengthened bond coatings, commercial Co–30wt-%Ni–20Cr–8Al–0•4Y powder was milled with 2% additions of Al2O3, Y2O3 or Y2O3 + HfO2. Low-pressure plasma sprayed, free-standing specimens were oxidised in air + 10%H2O at 1100 °C both isothermally (100 h) and in 500, 1-h cycles. Dry air cyclic testing conducted at both ORNL and FZJ showed remarkably similar results. In general, the water vapour addition caused more scale spallation. Two LPPS specimens without oxide additions were tested for comparison. The specimens with 2%Al2O3 addition exhibited the best behaviour as the powder already contained 0•4%Y. Additions of 2%Y2O3 and especially 1%Y2O3 + 1%HfO2 resulted in over-doping as evidenced by high mass gains and the formation of Y- and Hf-rich pegs. Scanning transmission electron microscopy of the isothermal specimens showed no Hf and/or Y segregation to the alumina scale grain boundaries in the over-doped specimens.

Schottky Quantum Dot Solar Cells Stable in Air under Solar Illumination

KAUST Repository

Tang, Jiang

2010-01-07

(Figure Presented) The air stability and power conversion efficiency of solution-processed PbS quantum dot solar cells is dramatically improved by the insertion of 0.8 nm LiF between the PbS nanoparticle film and the Al contact. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

La situación energética en el Pacto Andino

OpenAIRE

Centro de Estudios Sudamericanos

2008-01-01

Los países de la región han venido modernizando sus sectores energéticos y han adoptado enfoques similares en cuanto a objetivos generales como la búsqueda de la eficiencia mediante mecanismos de mercado donde ello sea posible; la tendencia al alejamiento del Estado de actividades puramente empresariales y su focalización en los temas de regulación y control; la puesta en marcha de políticas transparentes que promuevan la competencia; y la participación de inversionistas privados, etc. No obs...

La realidad aumentada en el aula de E/LE. Layar como herramienta dinamizadora e interactiva

Directory of Open Access Journals (Sweden)

Cristina Carballal

2015-10-01

A través de la puesta en práctica de la actividad «Hoy cocinas tú», dirigida a estudiantes de español de nivel básico, pretendemos ofrecer al alumno un acercamiento práctico a los contenidos teóricos previamente presentados. Con el objetivo de la realización de una receta simple de la cocina española y a lo largo de una sesión de 60 minutos, los estudiantes practicarán conocimientos gramaticales, léxicos, funcionales y culturales.

Ácido linoleico conjugado en leche de oveja y productos derivados: presencia e influencia del proceso tecnológico

OpenAIRE

Rodríguez Castañedas, José Luis

2012-01-01

[ES] El objetivo general de este trabajo es conocer el contenido de isómeros del Ácido Linoleico Conjugado (CLA) en leche de oveja parcialmente desnatada y tratada térmicamente, así como en yogur y cuajada elaborados con leche de la misma especie animal. Hasta el momento, no existen datos en productos españoles destinados al consumo. Para alcanzar el objetivo general, se han planteado tres objetivos parciales que se exponen a continuación: 1)Puesta a punto de un método que permita la cuan...

Red continua de espacios públicos verdes a escala municipal: el caso de Madrid

OpenAIRE

Casado Postigo, Pablo

2015-01-01

La ubicación marginal y el aislamiento de los Parques Urbanos implican infrautilización y deterioro de los mismos. Su interconexión mediante una red verde peatonal con limitaciones al tráfico rodado, supone una puesta en valor de todo el sistema de espacios libres y zonas verdes de la ciudad y un importante incentivo para desviar determinados flujos rodados a otras vías cercanas, rescatando así, espacios urbanos a favor del peatón. Esta conexión ayuda a minimizar la fragmentación del espacio ...

Instantes velados, escenas retenidas: pequeña escala en la arquitectura finlandesa en el siglo XX: villas, residencias y saunas

OpenAIRE

Rodríguez Andrés, Jairo

2013-01-01

La investigación aborda el tema de la pequeña escala residencial, tan rica y fructífera como desconocida en el ámbito arquitectónico finlandés. Paralelamente al desarrollo de este país y a la emergencia de Alvar Aalto, ha existido un conjunto de obras aparentemente menores que, por su trascendencia, han tratado de ser entendidas y puestas en valor en este trabajo. En este proceso se han establecido cuatro categorías, una por capítulo, representativas de las sensibilidades co...

Avances sobre el cultivo de la centolla (Maja squinado Herbst 1788)

OpenAIRE

Iglesias-Estévez, J. (José); Sánchez-Conde, F.J. (Francisco Javier); Moxica, C. (Covadonga); Fuentes, L. (Lidia); Otero-Pinzas, J.J. (Juan José)

2003-01-01

En este trabajo se muestran los datos preliminares obtenidos a lo largo de los años 2001 y 2002 en el IEO de Vigo, referidos a la reproducción, cultivo larvario y engorde de juveniles de centolla (Maja squinado, Herbst 1788). Se obtuvieron de 3 a 5 puestas de cada hembra estabulada. El cultivo larvario se realizó en dos sistemas: intensivo y semiextensivo; la supervivencia larvaria en el primero osciló entre 8 y 13% al mes de vida. A partir de los 50 días de edad, los juveniles...

Tratamiento quirúrgico e intervencionista de la insuficiencia valvular mitral: revisión del documento de consenso de los Grupos de Trabajo en Cirugía Cardiovascular y Valvulopatías de la Sociedad Europea de Cardiología

OpenAIRE

Rafael García Fuster

2016-01-01

En este documento de consenso de los Grupos de Trabajo en Cirugía Cardiovascular y Valvulopatías de la Sociedad Europea de Cardiología se realiza una puesta al día sobre el manejo más adecuado de los pacientes con insuficiencia valvular mitral. El manuscrito publicado en el mes de enero del 2016 en el European Heart Journal recoge los siguientes puntos: – una enumeración de los principales aspectos clave sobre la evidencia científica referente a este tema; – la importancia de un abordaj...

La Construcción de Políticas Turísticas Orientadas a los Sectores Medios Durante el Primer Peronismo: Argentina 1946-1955

OpenAIRE

Piglia, Melina; Pastoriza, Elisa

2017-01-01

En el marco general de los estudios de las políticas públicas durante el primer peronismo (Argentina 1946-1955), el presente trabajo pretende abordar aspectos descuidados de las políticas turísticas, desde una perspectiva de historia social. El artículo sostiene que, junto a las más conocidas transformaciones producidas en el campo del turismo obrero y el turismo social, se puede advertir durante el período peronista la puesta en marcha de políticas turísticas orientadas al turismo de los sec...

"Lo hicimos ayer, hoy y lo seguiremos haciendo en todos los puestos que nuestra Patria nos necesite" : Análisis de las estrategias del gobierno dictatorial uruguayo para ampliar sus bases de apoyo, y sus recepciones periodísticas, políticas y sociales (1973-1980). Estudio enfocado en la ciudad de Durazno

OpenAIRE

Correa Morales, Javier

2015-01-01

La tesis estudia y analiza una serie de estrategias puestas en prácticas por el régimen cívico militar para construir consensos, entre 1973 y 1980, así como la diversidad de respuestas y actitudes periodísticas, políticas y sociales que, sobre todo, sirvieron de apoyo al régimen. El enfoque está centrado en una localidad del interior, la ciudad de Durazno, o sea: estudia un problema nacional en un escenario específico. Pretende aportar a los estudios sobre el papel que jugaron distintos sujet...

Descontextualización de las teorías financieras: ¿se puede hablar de factores determinantes de la estructura de capital de las PYME venezolanas?

OpenAIRE

María Cristina Fernández

2010-01-01

Las distintas teorías que tratan de explicar la estructura de capital de las empresas, nos ofrecen un abanico de variables que podrían justificar el comportamiento de la estructura del pasivo fijo o financiación permanente; esto es, la combinación óptima de deuda a largo plazo y fondos propios que financian las inversiones permanentes necesarias para la puesta en marcha y desarrollo continuado de la actividad empresarial. Sin embargo, muchas de estas teorías no son útiles al ser a...

El mártir armenio: La construcción política de una figura ejemplar después del genocidio (1915-1918)

OpenAIRE

Antaramián Salas, Carlos

2008-01-01

La figura ejemplar del mártir ha tenido un papel fundamental en la política de memoria estructurada por las comunidades armenias después del genocidio (1915-1918); funge como imagen de honra nacional que ayuda al mantenimiento de la identidad armenia en espacios de asimilación (países anfitriones de la diáspora). En este artículo presento las transformaciones por las cuales ha transitado esta figura a partir de su puesta en escena cada 24 de abril, fecha de conmemoración del genocidio que se ...

El mártir armenio: la construcción política de una figura ejemplar después del genocidio (1915-1918

Directory of Open Access Journals (Sweden)

Carlos Antaramián Salas

2008-06-01

Full Text Available La figura del mártir ha tenido un papel fundamental en la política de memoria estructurada por las comunidades armenias después del genocidio (1915-1918; funge como imagen de honra nacional que ayuda al mantenimiento de la identidad armenia en espacios de asimilación (países anfitriones de la diáspora. En este artículo presento las transformaciones por las cuales ha transitado esta figura a partir de su puesta en escena cada 24 de abril, fecha de conmemoración del genocidio.

Complicaciones mecánicas de los accesos venosos centrales

Directory of Open Access Journals (Sweden)

Dr. T. Rodrigo Rivas

2011-05-01

En esta puesta al día se describen las complicaciones más frecuentes o de mayor gravedad como son: el neumotórax, la embolia aérea, mal-posición del catéter, perforación de grandes venas, punción arterial, arritmias, trombosis venosa asociada a catéter venoso central (CVC y oclusión del CVC; algunos elementos de prevención, diagnóstico y tratamiento así como el impacto que puede tener la ultrasonografía rutinaria para instalar un CVC.

La Publicidad en internet : procesamiento y reactancia psicológica entre los usuarios y consumidores de la red

OpenAIRE

Padilla, Alexander

2010-01-01

Treball Final de Màster Oficial de Publicitat i Relacions Públiques. Curs 2009-2010. Direcció: Dra. Elena Añaños La evolución de la publicidad en internet en estos últimos años está siendo muy importante, sobretodo, debido a la aparición y puesta en marcha de los nuevos formatos publicitarios que permiten sorprender al usuario que navega por internet. Mediante esta investigación se pretende conocer si el internauta percibe o no publicidad mientras navega por Internet, en que tipo de página...

Complicaciones mecánicas de los accesos venosos centrales

OpenAIRE

Rodrigo Rivas, T.

2011-01-01

Las complicaciones mecánicas de los accesos venosos centrales son frecuentes, 2 a 15% y en ocasiones pueden comprometer la vida del paciente. Hay factores que determinan el riesgo de una u otra, que pueden ser modificados o enfrentados de diferente forma para minimizarlo. En esta puesta al día se describen las complicaciones más frecuentes o de mayor gravedad como son: el neumotórax, la embolia aérea, mal-posición del catéter, perforación de grandes venas, punción arterial, arritmias, trom...

Dynamic behavior of reactive aluminum nanoparticle-fluorinated acrylic (AlFA) polymer composites

Science.gov (United States)

Crouse, Christopher A.; White, Brad; Spowart, Jonathan E.

2011-06-01

The dynamic behavior of aluminum nanoparticle-fluorinated acrylic (AlFA) composite materials has been explored under high strain rates. Cylindrical pellets of the AlFA composite materials were mounted onto copper sabots and impacted against a rigid anvil at velocities between 100 and 400 m/s utilizing a Taylor gas gun apparatus to achieve strain rates on the order of 104 /s. A framing camera was used to record the compaction and reaction events that occurred upon contact of the pellet with the anvil. Under both open air and vacuum environments the AlFA composites demonstrated high reactivity suggesting that the particles are primarily reacting with the fluorinated matrix. We hypothesize, based upon the compaction history of these materials, that reaction is initiated when the oxide shells on the aluminum nanoparticles are broken due an interparticle contact deformation process. We have investigated this hypothesis through altering the particle loading in the AlFA composites as well as impact velocities. This data and the corresponding trends will be presented in detail.

[Retrospective study of ALS in French military personnel].

Science.gov (United States)

Drouet, A; Desjeux, G; Balaire, C; Thevenin-Garron, V

2010-01-01

An apparent increased risk for developing Amyotrophic Lateral Sclerosis (ALS), a multifactorial neurodegenerative disease, is considered to exist in the military population. ALS military and veteran patients were retrospectively recruited in April 2008 by searching medical data (Hippocrate) and repayment data (Erasme) of the French National Military Health Care Fund (Caisse nationale militaire de sécurité sociale, CNMSS) from de January 1991 to December 2007. We report a series of 73 patients, 69 male and four female, average age of 52.5 years (range 27 to 72 years) with a peak of patients in the 50-59 year age class. The branch of military service was Army (n=26 patients), Air force (n=14), Navy (n=10) and State Police Force (n=22). The incidence among male active duty military personnel was stable from 2002 to 2007; it was less than the general population (1.7/100,000 per year in 2007), but higher in the 40-44 and 50-54 year age classes (1.90 and 5.07/100,000 per year in 2007 respectively). Duration of active duty was on average 31 years. The retrospective nature of the data and the incomplete population with loss of retired military personnel without CNMSS affiliation are limitations of our study. Another means of collecting all cases of ALS among French military personnel and veterans would be to conduct a search in the 17 ALS centers in France with analysis by occupational activity for entire career.

Zenith-100 Microcomputer Network for Air Command and Staff College.

Science.gov (United States)

1987-04-01

34 AD-A182 495 ZENI T-ipo ml CROCOMFUT E NET WOR( FOR AIR COMAND AND h SAFF CoLLG (U) AIl COMMAND ANDCSTAFF COLL MAX(WELL AFS "CAL W L GALWAY El AL...processing of documents by eliminating the time required to physically move the documents from one office to the next. Reproduction Savings. Information

Synthesis of high-surface-area spinel-type MgAl2O4 nanoparticles by

Indian Academy of Sciences (India)

2Institute of Chemical Technologies, Iranian Research Organization for Science and Technology, Tehran ... on synthesis and textural properties of magnesium aluminate nanopowders. .... −1 over temper- ature range of 10–900. ◦. C, in air atmosphere. XRD patterns ..... assigned to two phases of MgAl2O4 (JCPDS PDF no.

Development of an oxidation resistant glass-ceramic composite coating on Ti-47Al-2Cr-2Nb alloy

Science.gov (United States)

Li, Wenbo; Zhu, Shenglong; Chen, Minghui; Wang, Cheng; Wang, Fuhui

2014-02-01

Three glass-ceramic composite coatings were prepared on Ti-47Al-2Cr-2Nb alloy by air spraying technique and subsequent firing. The aim of this work is to study the reactions between glass matrix and inclusions and their effects on the oxidation resistance of the glass-ceramic composite coating. The powders of alumina, quartz, or both were added into the aqueous solution of potassium silicate (ASPS) to form slurries used as the starting materials for the composite coatings. The coating formed from an ASPS-alumina slurry was porous, because the reaction between alumina and potassium silicate glass resulted in the formation of leucite (KAlSi2O6), consuming substantive glass phase and hindering the densification of the composite coating. Cracks were observed in the coating prepared from an ASPS-quartz slurry due to the larger volume shrinkage of the coating than that of the alloy. In contrast, an intact and dense SiO2-Al2O3-glass coating was successfully prepared from an ASPS-alumina-silica slurry. The oxidation behavior of the SiO2-Al2O3-glass composite coating on Ti-47Al-2Cr-2Nb alloy was studied at 900 °C. The SiO2-Al2O3-glass composite coating acted as an oxygen diffusion barrier, and prevented the inward diffusion of the oxygen from the air to the coating/alloy interface, therefore, decreasing the oxidation rate of the Ti-47Al-2Cr-2Nb alloy significantly.

Short-Term Introduction of Air Pollutants from Fireworks During Diwali in Rural Palwal, Haryana, India: A Case Study

Science.gov (United States)

Gautam, S.; Yadav, A.; Pillarisetti, A.; Smith, K.; Arora, N.

2018-03-01

The contribution of firework-related air pollutants into the rural atmosphere was monitored by measuring ambient air concentrations of PM2.5, CO, and metals over Mitrol- Aurangabad, Haryana, India, before, during, and after the 2015 Diwali celebration. PM2.5 concentrations were observed to be approximately 5 times and 12 times higher than Indian and WHO 24-h standards, respectively. CO concentrations on the day of Diwali were found to be nearly 7.5 times and nearly 1.5 times higher than Indian standards and WHO 8-h standards, respectively. Increased concentrations of SO4, K, N3, Al, and Na were observed. SO4, K, N3, Al, and Na were found between approximately 2 and 5 times higher on festival days than on a normal, non-festival day in November. Use of firecrackers during Diwali and surrounding celebrations thus contribute to decreased air quality and elevated levels of air pollutants associated with adverse health impacts. Optimization or controlled use of firecrackers during Diwali is suggested in rural areas.

Air filtration and indoor air quality

DEFF Research Database (Denmark)

Bekö, Gabriel

2006-01-01

Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

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

Directory of Open Access Journals (Sweden)

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.

AIR SEPARATION BY PRESSURE SWING ADSORPTION USING SUPERIOR ADSORBENTS; FINAL

International Nuclear Information System (INIS)

Ralph T Yang

2001-01-01

Li-X zeolite (Si/Al= 1.0) is currently the best sorbent for use in the separation of air by adsorption processes. In particular, pressure swing adsorption (PSA) using zeolite sorbents is being increasingly used for air separation. Silver is also known to strongly affect the adsorptive properties of zeolites; and it is known that thermal vacuum dehydration of silver zeolites leads to the formation of silver clusters within the zeolite. In this work we have synthesized type X zeolites containing Ag and also varying mixtures of Li and Ag. In this project, we developed the Ag-containing zeolite as the best sorbent for air separation. We have also studied Co-ligand compounds as oxygen-selective sorbents. Syntheses, structural characterization and adsorption properties have been performed on all sorbents. The results are described in detail in 5 chapters

La Virtualización de la Afectividad

Directory of Open Access Journals (Sweden)

Eva Alfama

2005-05-01

Full Text Available El trabajo inmaterial, al amparo de las sociedades postfordistas actuales donde la vida ha sido puesta a trabajar, se desarrolla operando sobre una constelación de intangibles como son el conocimiento, la información, los saberes, la comunicación o los afectos. Ocio y negocio, tiempo de descanso y de trabajo, relaciones personales y profesionales se entremezclan cada vez más hasta con-fundirse en un solo momento productivo. Así, el universo de lo afectivo, mientras antes se quedaba relegado al terreno de lo privado, hoy día cobra especial relevancia tanto por convertirse en materia prima de gobierno y capital como en fuente de estrategias de cooperación que desafían el orden social.

In which direction is budgeting moving? A report in large firms of Spain

Directory of Open Access Journals (Sweden)

Edilberto J. Rodríguez Rivero

2013-01-01

Full Text Available En este trabajo se ofrecen evidencias de la práctica presupuestaria de 135 empresas de gran tamaño localizadas en España. Los datos obtenidos nos han permitido evaluar un amplio abanico de deficiencias atribuidas al procedimiento presupuestario tradicional, aún hoy puestas en entredicho, así como vislumbrar hacia qué paradigma presupuestario emergente se alinea la práctica analizada. Los resultados obtenidos ponen de manifiesto que los procedimientos presupuestarios empleados por las empresas estudiadas solventan gran parte de las limitaciones atribuidas a la gestión presupuestaria tradicional. Al mismo tiempo observamos que en la mayor parte de los casos estudiasos dichos procedimientos se encuentran en línea con la propuesta conceptual del Better Budgeting.

Neutron Tests at the Start-Up of EDF1; Les essais neutroniques au demarrage du reacteur EDF1; Nejtronnye izmereniya pri puske reaktora EDF1; Ensayos neutronicos efectuados durante la puesta en marcha del reactor EDF1

Energy Technology Data Exchange (ETDEWEB)

Teste du Bailler, A. [Centre d' Etudes Nucleaires de Saclay (France); Janin, R. [Electricite de France, Paris (France)

1963-10-15

. Au cours de certains paliers de temperature (jusqu'a 140{sup o}C), des mesures de coefficients de temperature et d'efficacite de barres de controle ont ete effectuees. Dans le meme temps des mesures d'indices de spectre ont ete realisees par activation de detecteurs appropries (U, Pu, Lu, Mn, In, Au). La technique d'oscillation a ete utilisee pour mesurer l'efficacite de certains barres de compensation. Enfin des mesures de neutrons rapides ont ete faites concernant les etudes de protection et de dommages sur le graphite. (author) [Spanish] Con motivo de la puesta en marcha del reactor EDF1 los autores efectuaron una serie de mediciones neutronicas utilizando los principales metodos experimentales perfeccionados en los reactores de Marcoule. Las mediciones versaron esencialmente sobre la eficacia de las barras de control a diferentes profundidades. Sobre esta base los autores elaboraron un plan de extraccion de las barras que permite alcanzar la plena potencia respetando ciertos limites impuestos por la temperatura de las envolturas y del gas. Paralelamente, llevaron a cabo mediciones del flujo para distintas posiciones de las barras de compensacion y para diferentes absorbentes en ciertos canales, con arreglo a calculos de prevision bidimensionales. Estas mediciones se efectuaron por activacion de detectores puntiformes, recurriendo a la tecnica clasica por envenenamiento mediante aire. Dentro de ciertos intervalos de temperatura (hasta 140{sup o}C) efectuaron mediciones de los coeficientes termicos y de la eficacia de las barras de control. Al mismo tiempo, realizaron mediciones de los indices espectrales por activacion de detectores apropiados (U, Pu, Lu, Mn, In, Au). Utilizaron la tecnica de oscilacion para medir la eficacia de ciertas barras de compensacion. Por ultimo, efectuaron mediciones de neutrones rapidos relacionados con los estudios de proteccion y de dafios provocados en el grafito. (author) [Russian] Seriya njtronnykh izmerenij s primeneniem osnovnykh

FAA Air Traffic Activity, Fiscal Year 1980,

Science.gov (United States)

1980-09-30

CONTROL I(8ERS B1 STATE1*1 ICONIINULD) STATE AN0 LOCATION U AIR AIR GENERAL -ML -" LOCATION NAME INOLN IF ItR 6 a01AL CARRIER TAXI AVIATION MILITAR...I RUC 235 0 0 19 216 RLSEAU P14 N 2 IMP 55 1 I §4 0 RSEBUKG L N 2 SE 718 0 0 78 0 ROSWELL NM N 1 ROW 902 196 66 5,2 96 RUGBY NC h 2 1MP 0 C 5 0...LIT1) LA 301.2 291 P85 2989 22 At0101111 1UNICIPAL 1083) L A b1 0 1 63 0 CkOH~ty It 1.L’S (321 LA 3 0 0 3 0 LUN ICt (E8) LA 50 C 0 52a 0 TNT AC CASTAL

Kinetic studies of oxidation of {gamma}-AlON-TiN composites

Energy Technology Data Exchange (ETDEWEB)

Zhang Zuotai; Wang Xidong; Li Wenchao

2005-01-25

The present article deals with the investigation of the oxidation kinetics of {gamma}-aluminum oxynitride-Titanium Nitride composites (AlON-TiN) in the temperature range of 1100-1300 deg. C by thermogravimetry. Oxidation experiments with AlON-TiN composite plates have been carried out in air both in isothermal and nonisothermal modes. The results showed that the rate of oxidation was negligible below 1000 deg. C, and showed an increase with increasing temperature at higher temperature. Both isothermal studies as well as experiments with ramped temperature clearly indicated that the mechanism of the reaction changes around 1400 deg. C. In the nonisothermal mode, the oxidation curve showed an increased reaction rate in this temperature range. Oxidation of AlON-TiN composite results in {alpha}-Al{sub 2}O{sub 3} and TiO{sub 2} at a low temperature and Al{sub 2}TiO{sub 5} at higher temperature. The buildup of the product layer leads to diffusion controlled kinetics. In the nonisothermal experiments, the phase transformation from Al{sub 2}O{sub 3} and TiO{sub 2}, to a Al{sub 2}TiO{sub 5} product layer at higher temperature would lead to crack formation, thereby leading to direct chemical reaction. From the experiments for the isothermal oxidation of AlON-TiN composite plates, the overall reactions are separated into three stages: chemistry reaction-controlling stage; chemical reaction- and diffusion-mixed-controlled stage; diffusion-controlled stage. The apparent activation energy for the experiments were calculated to be 10.109, 2.19 and 5.614 kJ mol{sup -1}, respectively, in the above three stages.

Cuando la alegría entra al centro de salud: una experiencia de promoción de salud en Buenos Aires, Argentína

Directory of Open Access Journals (Sweden)

Claudia Bang

2016-06-01

Full Text Available Como parte de una investigación posdoctoral, el presente trabajo describe y analiza una experiencia de promoción y educación para la salud integral desarrollada por un Centro de Salud y Acción Comunitaria en una zona marginal urbana del sur de la Ciudad de Buenos Aires. Se trata de un estudio exploratorio-descriptivo que utiliza técnicas cualitativas para el trabajo de campo y análisis del material. En articulación con las dimensiones de la APS integral, se describe y analiza un dispositivo vincular, centrado en la interdisciplina y la articulación intersectorial como elementos clave de la organización de los cuidados en salud, con la inclusión de la dimensión intercultural y la participación comunitaria. Se incorporan actividades de promoción de salud integral centradas en el arte, creatividad y juego, constituyéndose en una experiencia resistencial al modelo biomédico de atención, con fuerte impacto subjetivo en los profesionales y la comunidad participante.

Air oxidation of Zr65Cu17.5Ni10Al7.5 in its amorphous and supercooled liquid states, studied by thermogravimetric analysis

International Nuclear Information System (INIS)

Dhawan, A.; Sharma, S.K.; Raetzke, K.; Faupel, F.

2003-01-01

The oxidation behaviour of the bulk amorphous alloy Zr 65 Cu 17.5 Ni 10 Al 7.5 was studied in air at various temperatures in the temperature range 591-732 K using a thermogravimetric analyser (TGA). The oxidation kinetics of the alloy obeys the parabolic rate law showing two different linear regions (in the plots of mass gain versus square root of oxidation time) which are attributed to the amorphous and the supercooled liquid states of the alloy. The value of the activation energy Q for the amorphous state as calculated from the temperature dependence of the rate constants is found to be 1.80±0.1 eV and the corresponding value obtained for the supercooled liquid state is 1.20±0.1 eV. It is suggested that the rate controlling process during oxidation of the amorphous state is the back-diffusion of Ni, and possibly Cu also, while the oxidation in the supercooled liquid state is dominated by the inward diffusion of oxygen. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

EL ITINERARIO COMO HERRAMIENTA PARA LA PUESTA EN VALOR TURÍSTICO DEL PATRIMONIO TERRITORIAL

OpenAIRE

Alfonso M. Doctor

2011-01-01

Se presentan los antecedentes, desarrollo y avance de resultados del proyecto de investigación «Articulación de los recursos patrimoniales turísticos y aplicación de la tecnología SIG a su planificación y gestión» (Proyecto A/017070/08, financiado durante las anualidades 2009 y 2010 por la Agencia Española de Cooperación Internacional al Desarrollo, AECID, del Ministerio de Asuntos Exteriores), desarrollado por un equipo conjunto de las universidades Austral de Chile, Católica de Salta (Argen...

Construcción y puesta en marcha de una impresora 3D modelo Rostock

OpenAIRE

Ponce Antolín, Miguel

2014-01-01

Proyecto dedicado a documentar la construcción de una máquina de prototipado rápido por deposición de material fundido o impresora 3D. El modelo construido, denominado como Rostock, es un ejemplo de máquina de cinemática paralela de bajo coste. Esta arquitectura permite alcanzar mayores aceleraciones y velocidades. Además, proporciona una mayor estabilidad al cabezal impresor y dobla la altura de impresión en comparación con las impresoras de bajo coste más difundidas. Este ...

Soft Magnetic Properties of High-Entropy Fe-Co-Ni-Cr-Al-Si Thin Films

Directory of Open Access Journals (Sweden)

Pei-Chung Lin

2016-08-01

Full Text Available Soft magnetic properties of Fe-Co-Ni-Al-Cr-Si thin films were studied. As-deposited Fe-Co-Ni-Al-Cr-Si nano-grained thin films showing no magnetic anisotropy were subjected to field-annealing at different temperatures to induce magnetic anisotropy. Optimized magnetic and electrical properties of Fe-Co-Ni-Al-Cr-Si films annealed at 200 °C are saturation magnetization 9.13 × 105 A/m, coercivity 79.6 A/m, out-of-plane uniaxial anisotropy field 1.59 × 103 A/m, and electrical resistivity 3.75 μΩ·m. Based on these excellent properties, we employed such films to fabricate magnetic thin film inductor. The performance of the high entropy alloy thin film inductors is superior to that of air core inductor.

Evaluación del programa de educación ambiental formal “aula al aire libre”, Reserva Los Coyotes

Directory of Open Access Journals (Sweden)

Hernández Chaves, María Gabriela

2013-05-01

Full Text Available Resumen: El presente artículo muestra la evaluación realizada al programa “Aula al Aire Libre” de la Reserva Los Coyotes (Mata de Plátano, Goicoechea, en San José, Costa Rica, con el fin de presentarlo como una metodología innovadora y efectiva para la educación formal. Durante el 2010, se evaluó el nivel de conocimiento de los estudiantes participantes (n= 1085 antes y después del trabajo de campo utilizando pruebas cortas. El análisis de los resultados indicó que el momento de la prueba (antes/después tiene un efecto significativo en la nota obtenida; es decir, como consecuencia de su trabajo en Los Coyotes la cantidad de respuestas correctas aumentó de manera significativa. Para comparar la eficiencia de esta metodología con la del sistema tradicional de enseñanza, las evaluaciones post-visita fueron también administradas a un grupo control (n=498. Los resultados revelaron que los estudiantes participantes tienen un mejor manejo de los temas en cuestión que los estudiantes del grupo control. Además se aplicaron encuestas a los estudiantes y docentes de las escuelas participantes; tanto docentes como estudiantes mostraron altos niveles de satisfacción y consideraron el programa como una herramienta eficiente en la enseñanza de los contenidos formales. La encuesta además permitió identificar las fortalezas y debilidades del programa, dando así al personal de Los Coyotes información importante para reformular y mejorar la práctica. Abstract: This paper presents the evaluation of the program "Outdoor Classroom" of Reserva Los Coyotes (Mata de Plátano, Goicoechea, in San José, Costa Rica, in order to evince it as an innovative and effective methodology for formal education. During 2010, the level of knowledge of participating students (n = 1085 was assessed before and after the field work, using quiz-like instruments. The analysis of the results indicated that the moment of testing (before / after has a significant

Proton irradiation studies on Al and Al5083 alloy

Science.gov (United States)

Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

2017-10-01

The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

Evaluation of the impact of general phosphate fertilizers factories company on the surrounding environment by determining natural radionuclides and some trace elements in air particulates

International Nuclear Information System (INIS)

Al-Masri, M. S.; Al-Kharfan, K.; Al-Hamwi, A.; Al-Shamali, K.

2004-01-01

Natural radionuclides and some trace element levels in air particulates of the areas surrounding the phosphate fertilizers factory in Homs have been determined Mean total air particulates concentration ranged from 31 μg/m3 in Kerba Al-Teen in Autumn period. While trace element concentrations in air particulates were relatively high in air particulates collected from AECS center and other sites situated north east of the factory; about 1.7 ng/m3 in AECS site and 1.7 ng/m3 in Abel for uranium and cadmium, respectively. In addition, radioactivity analysis of air particulates has shown low levels of polonium 210 and lead 210; a value of 2 mBq/m3 in Kerba Al-Teen has not been exceeded. However, air particulate, natural radionuclides and the studied trace elements concentrations in the surrounding areas were within the natural levels. Therefore, air emissions from the factory containing radioactive materials and trace elements are relatively low. This is due to strict control procedures on transport and loading processes of phosphate in addition to the high efficiency of filters used for air emissions from the phosphate fertilizers factory during the study period (2002). (author)

Evaluation of the impact of general phosphate fertilizers factories company on the surrounding environment by determining natural radionuclides and some trace elements in air particulates

International Nuclear Information System (INIS)

Al-Masri, M. S.; Al-Kharfan, K.; Al-Hamwi, A.; Al-Shmali, K.; Abdul Haleem, M.

2003-12-01

Natural radionuclides and some trace element levels in air particulates of the areas surrounding the phosphate fertilizers factory in Homs have been determined mean total air particulates concentration ranged from 31μg/m 3 in Kerba Al-Teen in autumn period. While trace element concentrations in air particulates were relatively high in air particulates collected from AECS center and other sites situated north east of the factory: about 1.7 ng/m 3 in AECS site and 1.7 ng/m 3 in Abel for uranium and cadmium, respectively. In addition, radioactivity analysis of air particulates have shown low levels of polonium 210 and lead 210, a value of 2 mBg/m 3 in Kerba Al-Teen has not been exceeded. However, air particulate, natural radionuclides and the studied trace elements concentrations in the surrounding areas were within the natural levels. Therefore, air emissions from the factory containing radioactive materials and trace elements are relatively low. This is due to strict control procedures on transport and loading processes of phosphate in addition to the high efficiency of filters used for air emissions from the phosphate fertilizers factory during the study period (2002).(author)

El declive de una población costera cantábrica de Rana bermeja (Rana temporaria

Directory of Open Access Journals (Sweden)

GOSA, A.

1998-01-01

Algunas de las características reproductoras de la población son de notable alargamiento de su periodo de puesta, que comienza a primeros de noviembre y puede extenderse hasta febrero y primeros de marzo ; la baja fecundidad de las hembras (media de 1006 huevos por puesta y la permanencia de los machos en los charcos donde se reproducen(algunos pasan en ellos hasta dos meses y medio.El pico reproductor medio para el periodo de estudio se produce en la segunda decena de diciembre, fecha en la que ya se ha hecho el 60% de la puesta total.

PAST: Programa para el proyecto y análisis de sistemas de puesta a tierra. (Primera parte; SistPTEx: Program for the project and analysis of grounding system. (First part.

Directory of Open Access Journals (Sweden)

Angel Cecilio Valcárcel Rojas

2011-05-01

Full Text Available resistencia de contacto a tierra de diferentes configuraciones de electrodos, desde métodos aproximados, métodos semiexactos, hasta métodos que garantizan muy buenos niveles de exactitud. El desarrollo alcanzado por la computación ha permitido el rescate de algoritmos relativamente antiguos como los basados en la teoría de las imágenes de Maxwell, hasta el desarrollo de métodos basados en la teoría de los elementos finitos. En este trabajo se exponen las características y bondades de un programa para el proyecto y análisis de sistemas de puesta a tierra para cualquier instalación eléctrica, aplicando la teoría de las imágenes de Maxwell.  During the historical development of electrical engineering, have developed many methods for calculating the contact resistance grounding electrodes of different configurations, from approximate methods, semi exact methods up methods which guarantee good levels of exactness. The development achieved by the computer has enabled the rescue of relatively old algorithms, such as those based on the theory of Maxwell’s images, until the development of methods based on the theory of finite elements. In this paper we describe the features and benefits of a program for the design and analysis of grounding systems for any electrical installation, using the theory of Maxwell’s images.

PEMBARUAN MASLAḤAH DALAM MAQĀṢID AL- SHARĪ‘AH: TELAAH HUMANISTIS TENTANG AL-KULLIYYĀT AL-KHAMSAH

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Zaenuddin Mansyur

2012-06-01

Full Text Available Abstract:   In order to answer a variety of issues faced by human being in the current era, such as human rights abuses, social disintegration, and terrorism, the renewal of Islamic law in the level of theoretical and practical aspects is very urgent. This paper aims to examine one of the Islamic legal reform efforts, namely to build a more technical understanding of the concept of maṣlaḥah contained in the maqāṣīd sharī‘ah, called the al-kulliyat al-khamsah. Therefore, the concept of maṣlaḥah in ḥifẓ al-dīn is technically defined as al-ḥurriyah al-i‘tiqād (freedom of religion and schools; in ḥifẓ al-nafs as al-karamat al-insān (human being breeding; in ḥifẓ al-nasl as ḥifẓ al-usrah (wholeness and harmony of the family; in ḥifẓ al-māl as al-taḍammun al-insān (social solidarity , and in ḥifẓ al-‘aql as al-ḥuqūq as al-tarbiyāt (increasing human resources quality.Abstrak: Demi menjawab aneka persoalan zaman yang dihadapi manusia era sekarang, seperti penyelewengan terhadap HAM, disintegrasi sosial, dan terorisme, maka pembaharuan hukum Islam dalam tataran teoretis dan praktis urgen dilakukan. Tulisan ini bertujuan untuk mengkaji salah satu upaya pembaruan hukum Islam, yaitu membangun pemahaman yang lebih teknis terhadap konsep maṣlaḥah yang terkandung dalam maqāṣīd sharī‘ah, yang disebut dengan al-kulliyāt al-khamsah. Oleh karena itu, konsep maṣlaḥah dalam ḥifẓu al-dīn secara teknis dimaknai sebagai ḥurriyah al-i‘tiqād (kebebasan untuk beragama dan beraliran; dalam ḥifẓu al-nafs sebagai al-karāmāt al-insān (pemuliaan kemanusiaan; dalam ḥifẓu al-nasl sebagai ḥifẓu al-usrah (keutuhan dan keharmonisan keluarga; dalam ḥifẓu al-māl sebagai al-taḍammun al-insān (solidaritas sosial; dan dalam ḥifẓu al-‘aql sebagai al-ḥuqūq al-tarbiyāt (peningkatan sumber daya manusia.

Combustion synthesis of AlB2-Al2O3 composite powders with AlB2 nanowire structures

Science.gov (United States)

Yang, Pan; Xiao, Guoqing; Ding, Donghai; Ren, Yun; Yang, Shoulei; Lv, Lihua; Hou, Xing

2018-05-01

Using of Al and B2O3 powders as starting materials, and Mg-Al alloy as additives, AlB2-Al2O3 composite powders with AlB2 nanowire structures were successfully fabricated via combustion synthesis method in Ar atmosphere at a pressure of 1.5 MPa. The effect of different amount of Mg-Al alloy on the phase compositions and morphology of the combustion products was investigated. The results revealed that AlB2 and Al2O3 increased, whereas Al decreased with the content of Mg-Al alloy increasing. The impurities MgAl2O4 and AlB12 would exist in the sample with adding of 18 wt% Mg-Al alloy. Interestingly, FESEM/TEM/EDS results showed that AlB2 nanowires were observed in the products when the content of Mg-Al alloy is 6 wt% and 12 wt%. The more AlB2 nanowires can be found as the content of Mg-Al alloy increased. And the yield of AlB2 nanowires with the diameter of about 200 nanometers (nm) and the length up to several tens of micrometers (μm) in the combustion product is highest when the content of Mg-Al alloy is 12 wt%. The vapor, such as Mg-Al (g), B2O2 (g), AlO (g) and Al2O (g), produced during the process of combustion synthesis, reacted with each other to yield AlB2 nanowires by vapor-solid (VS) mechanism and the corresponding model was also proposed.

The effects of boron in TiAl/Ti3Al

International Nuclear Information System (INIS)

Feng, C.R.; Michel, D.J.; Crowe, C.R.

1989-01-01

The authors discuss the TiAl/Ti 3 Al interfacial misfit dislocations structures investigated by TEM in Ti-45Al alloy and Ti-45Al/TiB 2 composite. For TiAl with c/a = 1.02, only a single set of misfit dislocation arrays are crystallographically possible; these were observed in Ti-45Al alloy. However, the observation of three sets of misfit dislocation arrays in the Ti-45Al/TiB 2 composite suggests that the occupation of octahedral sites in the TiAl structure by excess boron was responsible for a decrease in the c/a ratio leading to an increased fcc character of the TiAl at the TiAl/Ti 3 Al interface

Corrosion Behavior of Detonation Gun Sprayed Fe-Al Type Intermetallic Coating

Science.gov (United States)

Senderowski, Cezary; Chodala, Michal; Bojar, Zbigniew

2015-01-01

The detonation gun sprayed Fe-Al type coatings as an alternative for austenitic valve steel, were investigated using two different methods of testing corrosion resistance. High temperature, 10-hour isothermal oxidation experiments at 550, 750, 950 and 1100 °C show differences in the oxidation behavior of Fe-Al type coatings under air atmosphere. The oxide layer ensures satisfying oxidation resistance, even at 950 and 1100 °C. Hematite, α-Al2O3 and metastable alumina phases were noticed on the coatings top surface, which preserves its initial thickness providing protection to the underlying substrate. In general, only negligible changes of the phase composition of the coatings were noticed with simultaneous strengthening controlled in the micro-hardness measurements, even after 10-hours of heating at 1100 °C. On the other hand, the electrochemical corrosion tests, which were carried out in 200 ppm Cl− (NaCl) and pH ~4 (H2SO4) solution to simulate the acid-rain environment, reveal higher values of the breakdown potential for D-gun sprayed Fe-Al type coatings than the ones for the bulk Fe-Al type alloy and Cr21Mn9Ni4 austenitic valve steel. This enables these materials to be used in structural and multifunctional applications in aggressive environments, including acidic ones. PMID:28787991

Mechanical properties and dual atmosphere tolerance of Ag-Al based braze

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Yong; Choi, Jung-Pyung; Scott Weil, K. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

2008-07-15

In this paper, the effects of aluminum on the microstructure, mechanical properties, and high temperature dual atmosphere tolerance of silver and silver-copper oxide filler metals were investigated. It was found that joints brazed with binary Ag-Al braze foils containing more than 2 at% Al retained a metallic form of aluminum within the metallic braze filler matrix after brazing at 1000 C in air. The bend strengths of these joints decreased with increasing aluminum content due to the formation of interfacial aluminum oxide. However, the existence of metallic aluminum in the braze filler matrix appeared to enhance the high-temperature dual atmosphere tolerance of the silver-based braze filler, which displayed measurably less porosity after 1000h of exposure at 800 C in a dual reducing/oxidizing atmosphere environment than unalloyed silver. A series of binary and ternary braze pastes based on the Ag-Al(-Cu) system were also formulated as potential pSOFC (planar solid oxide fuel cell) sealants. Model alumina joints brazed with these pastes exhibited an increase in bend strength with increasing copper content. However, unlike the binary Ag-Al filler metals, the ternary compositions often retained no protective metallic aluminum after brazing. Thus, while the addition of copper improves filler metal wettability and, therefore, joint strength in the Ag-Al alloys, it appears to reduce the dual atmosphere tolerance of these filler metals. (author)

Influence of thermal treatments on the basic and catalytic properties of Mg,Al-mixed oxides derived from hydrotalcites

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Bastiani R.

2004-01-01

Full Text Available This work studied the influence of calcination conditions on basic properties and catalytic performance of Mg,Al-mixed oxides derived from a hydrotalcite sample (Al/(Al+Mg=0.20. Various heating rates, calcination atmospheres and lengths of calcination at 723K were evaluated. TPD of CO2 and retroaldolization of diacetone alcohol (DAA were used to determine the basic properties of the mixed oxides. The basic site density determined by TPD of CO2 showed a better correlation with catalytic activity for acetone/citral aldol condensation than the relative basicity obtained from retroaldolization of DAA. Calcination atmosphere was the parameter that influenced most the basic and the catalytic properties of the Mg,Al-mixed oxides, with calcination under dry air being the best choice.

In Situ Fabrication of AlN Coating by Reactive Plasma Spraying of Al/AlN Powder

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Mohammed Shahien

2011-10-01

Full Text Available Reactive plasma spraying is a promising technology for the in situ formation of aluminum nitride (AlN coatings. Recently, it became possible to fabricate cubic-AlN-(c-AlN based coatings through reactive plasma spraying of Al powder in an ambient atmosphere. However, it was difficult to fabricate a coating with high AlN content and suitable thickness due to the coalescence of the Al particles. In this study, the influence of using AlN additive (h-AlN to increase the AlN content of the coating and improve the reaction process was investigated. The simple mixing of Al and AlN powders was not suitable for fabricating AlN coatings through reactive plasma spraying. However, it was possible to prepare a homogenously mixed, agglomerated and dispersed Al/AlN mixture (which enabled in-flight interaction between the powder and the surrounding plasma by wet-mixing in a planetary mill. Increasing the AlN content in the mixture prevented coalescence and increased the nitride content gradually. Using 30 to 40 wt% AlN was sufficient to fabricate a thick (more than 200 µm AlN coating with high hardness (approximately 1000 Hv. The AlN additive prevented the coalescence of Al metal and enhanced post-deposition nitriding through N₂ plasma irradiation by allowing the nitriding species in the plasma to impinge on a larger Al surface area. Using AlN as a feedstock additive was found to be a suitable method for fabricating AlN coatings by reactive plasma spraying. Moreover, the fabricated coatings consist of hexagonal (h-AlN, c-AlN (rock-salt and zinc-blend phases and certain oxides: aluminum oxynitride (Al₅O₆N, cubic sphalerite Al₂₃O₂₇N₅ (ALON and Al₂O₃. The zinc-blend c-AlN and ALON phases were attributed to the transformation of the h-AlN feedstock during the reactive plasma spraying. Thus, the zinc-blend c-Al

Corrosion resistance of structural material AlMg-2 in water following heat treatment and cooling

International Nuclear Information System (INIS)

Maman Kartaman A; Djoko Kisworo; Dedi Hariyadi; Sigit

2005-01-01

Corrosion tests of structural material AlMg-2 in water were carried out using autoclave in order to study the effects of heat treatment on the corrosion resistance of the material. Prior to the tests, the samples were heat-treated at temperatures of 90, 200, 300 and 500 °C and cooled in air, sand and water. The corrosion tests were conducted in water at temperature of 150 °C for 250 hours. The results showed that AlMg-2 samples were corroded although the increase of mass gain was relatively small. Heat treatment from 90 to 500 °C in sand cooling media resulted in an increase of mass gain despite that at 300 °C the increase was less than those at 200 °C and 500 °C. For water cooling media in the temperature range of 90 to 200 °C, the mass gain increased from 0.1854 g/cm 2 to 2.1204 g/cm 2 although after 200 °C it decreased to 1.8207 g/cm 2 and 1.6779 g/cm 2 respectively. For air cooling media, the mass gain was relatively constant. Based on the experiment results, it can be concluded that heat treatment and cooling did not significantly influence the corrosion resistance of material AlMg-2. The passive film Al 2 O 3 on the surface was able to protect the inner surface from further corrosion. Water media with pH range from 4 – 9 did not cause damage to passive layer formed. (author)

33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. (a...

Instability of TiC and TiAl3 compounds in Al-10Mg and Al-5Cu alloys by addition of Al-Ti-C master alloy

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

The performance of Al-Ti-C master alloy in refining Al-10Mg and A1-5Cu alloys was studied by using electron probe micro-analyzer (EPMA) and X-ray diffractometer (XRD) analysis.The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds.Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading.However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti(Al, Cu)2, which is responsible for the refinement fading in Al-5Cu alloy.These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.

Characterization of laser-induced ignition of biogas-air mixtures

International Nuclear Information System (INIS)

Forsich, Christian; Lackner, Maximilian; Winter, Franz; Kopecek, Herbert; Wintner, Ernst

2004-01-01

Fuel-rich to fuel-lean biogas-air mixtures were ignited by a Nd:YAG laser at initial pressures of up to 3 MPa and compared to the ignition of methane-air mixtures. The investigations were performed in a constant volume vessel heatable up to 473 K. An InGaAsSb/AlGaAsSb quantum well ridge diode laser operating at 2.55 μm was used to track the generation of water in the vicinity of the laser spark in a semi-quantitative manner. Additionally, the flame emissions during the ignition process were recorded and a gas inhomogeneity index was deduced. Laser-induced ignition and its accompanying effects could be characterized on a time scale spanning four orders of magnitude. The presence of CO 2 in the biogas reduces the burning velocity. The flame emissions result in a much higher intensity for methane than it was the case during biogas ignition. This knowledge concludes that engines fuelled with biogas ultimately affect the performance of the process in a different way than with methane. Methane-air mixtures can be utilized in internal combustion engines with a higher air-fuel ratio than biogas. Comparing failed laser-induced ignition of methane-air and biogas-air mixtures similar results were obtained. The three parameters water absorbance, flame emission and the gas inhomogeneity index constitute a suitable tool for judging the quality of laser-induced ignition of hydrocarbon-air mixtures at elevated pressures and temperatures as encountered in internal combustion engines

PEMAHAMAN HADITS TARBAWI BURHAN AL ISLAM AL ZARNUJI DALAM KITAB TA’LIM AL MUTA’ALLIM

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Benny Afwadzi

2017-01-01

Full Text Available This paper explores the understanding of tarbawi (education hadith from one of the major influential clerics in the Islamic educational system, especially in pesantren. He is Burhan al Islam al Zarnuji with his landmark book Ta’lim al Muta’allim. The conclusion that can be drawn is that al Zarnuji has shades of sufistical view in understanding tarbawi hadith. This can be seen in his understanding of hadith on obligation to seek knowledge (thalab al ilmi faridhatun ‘ala kulli muslimin wa muslimatin, which is interpreted as ilm al hal, the science concerning the condition of the human religious or simplistically said as the religious sciences; and the hadith of intention of studying (innama al a’malu bi al niyyat with the intention for the sake of the hereafter and religion, not mundane. Such an understanding is not something taken for granted, but it can be reinterpreted and perfected in accordance with the spirit of the times of context.

Royal Danish Air Force. Air Operations Doctrine

DEFF Research Database (Denmark)

Nørby, Søren

This brief examines the development of the first Danish Air Force Air Operations Doctrine, which was officially commissioned in October 1997 and remained in effect until 2010. The development of a Danish air power doctrine was heavily influenced by the work of Colonel John Warden (USAF), both...... through his book ”The Air Campaign” and his subsequent planning of the air campaign against Iraq in 1990-1991. Warden’s ideas came to Denmark and the Danish Air Force by way of Danish Air Force students attending the United States Air Force Air University in Alabama, USA. Back in Denmark, graduates from...... the Air University inspired a small number of passionate airmen, who then wrote the Danish Air Operations Doctrine. The process was supported by the Air Force Tactical Command, which found that the work dovetailed perfectly with the transformation process that the Danish Air Force was in the midst...

Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model

International Nuclear Information System (INIS)

Li, H.Q.; Yang, Y.S.; Tong, W.H.; Wang, Z.Y.

2007-01-01

With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni . To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24

Preparation of ZnO-Al2O3 Particles in a Premixed Flame

DEFF Research Database (Denmark)

Jensen, Joakim Reimer; Johannessen, Tue; Wedel, Stig

2000-01-01

Zinc oxide (ZnO) and alumina (Al2O3) particles are synthesized by the combustion of their volatilized acetylacetonate precursors in a premixed air-methane flame reactor. The particles are characterized by XRD, transmission electron microscopy, scanning mobility particle sizing and by measurement...... temperature and a decreasing precursor vapour pressure. The combustion of precursor mixtures leads to composite particles consisting of zinc aluminate ZnAl2O4 intermixed with either ZnO or Al2O3 phases. The zinc aluminate particles are dendritic aggregates, resembling the alumina particles, and are evidently...... synthesized to the full extent allowed by the overall precursor composition. The addition of even small amounts of alumina to ZnO increases the specific surface area of the composites significantly, for e.g. zinc aluminate particles to approximately 150 m2/g. The gas-to-particle conversion is initiated...

"Del archivo al concierto": un itinerario para la recuperación teórica y práctica del barroco musical hispánico

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Ezquerro Esteban, Antonio

2013-12-01

í conscientemente acotado al ámbito hispánico de los siglos XVII y XVIII, desde la localización documental de los manuscritos en los archivos, su transcripción, estudio y posterior edición crítica por parte del musicólogo, hasta su puesta en práctica por el músico con la interpretación pública en concierto.

Modelación de sistemas de puesta a tierra para evaluación de sobretensiones transitorias; Modelling large grounding systems to evaluate transient voltages

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Yandi Anibal Gallego Landera

2015-04-01

Full Text Available En plantas generadoras y en subestaciones se requieren sistemas de puesta a tierra (SPT espaciosos, con configuraciones complejas como parte del sistema de protección contra rayos. Las corrientes provocadas por una descarga atmosférica pueden causar altas tensiones en los cables de señales ubicados cerca de los SPT. Estas tensiones transitorias pueden causar falsas señales, las cuales provocan un mal funcionamiento de la instrumentación electrónica. Determinar medidas de protección contra rayos requiere del conocimiento de la máxima elevación de la tensión entre el SPT y la tierra remota. El presente trabajo propone una metodología para analizar el comportamiento transitorio de redes de tierra. La técnica se basa en considerar los diferentes segmentos de la malla de tierra como elementos de líneas de transmisión. Para desarrollar esta metodología se utilizó el software MATLAB-Simulink. Los resultados se validan por comparación con modelos basados en la teoría del campo electromagnético publicados en la literatura. In generating plants and substations spacious grounding systems with complex configuration as part of the protection system against lighting, are required. The current caused by an atmospheric discharge can cause high voltages in the signal cables located near the grounding systems. These transient voltages may be the reason for the occurrence of false signals, which can cause malfunctioning and of electronic instruments. The knowledge of maximum elevation of voltage between the grounding systems and the remote ground is required to determine protection against lightning. This paper proposes a methodology to analyze the transient behavior of grounding grid. The technique is based on considering the different segments of the ground grid as elements of transmission lines. For modeling the grounding systems behavior in its transient state faster, the MATLAB-Simulink software was used. The results were validated by

Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

International Nuclear Information System (INIS)

Peng, Enchao; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan; Hou, Xun; Wang, Zhanguo

2013-01-01

Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

Microstructure of MCMgAl12Zn1 magnesium alloy

Directory of Open Access Journals (Sweden)

Dobrzański L. A.

2007-01-01

Full Text Available In this paper is presented the structure of the cast magnesium alloys as cast state and after heat treatment cooled with different cooling rate, depending on the cooling medium (furnace, water, air. For investigations samples in shape of 250x150x25 mm plates were used. The structure have been study in the light microscope, scanning electron microscope equipped with an electron back scattering facility. The effects of the addition of Al on the microstructure were also studied. In the analysed alloys a structure of α solid solution and fragile phase β(Mg17Al12 occurred mainly on grain borders as well as eutectic and phase with Mn, Fe and Si. Investigation are carried out for the reason of chemical composition influence and precipitation processes influence to the structure and mechanical properties of the magnesium cast alloys with different chemical composition in as cast alloys and after heat treatment.

The code of light: al-ghazali and al-suhrawardi

OpenAIRE

Gediminaitė, Barbora

2017-01-01

The Code of Light: Al-Ghazali and Al-Suhrawardi The Bachelor’s thesis The Code of Light in Islam: al-Ghazali and al-Suhrawardi presents a comparative study of light. The study analyses the philosophical systems of al-Ghazali and al-Suhrawardi through the reconstruction of the image of light and its operation principles. The main subject of the thesis are the attributes of light. The main problem of the research is the semantics and contextuality of light in Islamic theology and philosophy. Th...

Pemikiran Filosofis Sadra Dalam Tafsir Al-Qur’an Al-Karim : Surah Al-’A‘la

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Kerwanto Kerwanto

2014-12-01

Full Text Available Abstrak : Dalam tafsir atas Surah al-’A‘lā, Mulla Sadra, melalui karyanya Tafsīr al Qur’ān al-Karīm, mengajak jiwa kita berpetualang menuju lapisan makna terdalam untuk mengenali realitas ketauhidan (al- mabdā’, kenabian (shirāth atau nubuwwah dan kebangkitan (ma‘ād dan mengulasnya secara filosofis. Penelitian ini merupakan suatu upaya untuk menggali manfaat dari aspek-aspek penting dari sumber-sumber keagamaan yang tergali dari petunjuk al Qur’an yang berpadu dengan prinsip- prinsip rasional filosofis dan pengalaman mistik (intuitif Sadra. Setiap bab pada tafsir ini diberikan judul dengan tasbīḥ (pernyataan pemujian dan pensucian, dengan tetap memaparkan beragam pokok persoalan terkait metafisika al-Qur’an. Prinsip-prinsip filosofis yang digunakan dalam risalah tafsir ini bisa menjadi salah satu bukti ketidakberjarakan antara filsafat dengan teks-teks keagamaan. Sadra menggunakan metode tafsir yang tetap menerima sisi lahiriah al-Qur’an, dan selanjutnya mencari misteri-misteri, rahasia-rahasia, dan dengan bantuan intelek (akal, intuisi dan iluminasi Tuhan untuk memperoleh realitas-realitas dan makna- makna dibalik selaput ekternalnya (aspek literalnyaKata kunci : Ḥikmah Muta’āliyah, irfan, al-mabdā’, kebangkitan setelah mati, nubuwwah, takwīl, gerak substansial (ḥarakah jawhariyyah, denotasi utama (al-maqshūd al-ashlī, penyempurnaan diri (takammul, tasbīḥ.  Abstract : In his commentary on Surah al-’ A‘lā, Mulla Sadra, through his Tafsīr al-Qur’ān al-Karīm invites our souls to ventureinto the deepest layers of meaning to recognize the reality of Divinity (al- mabdā’, prophethood (Ṣirāṭ or nubuwwah and resurrection (ma‘ād and discusses it in a more philosophical manner. This study is an attempt to explore the benefits of these important aspects of religious sources unearthed from Qur’anic injunctions combined with rational principles of philosophical and mystical experiences

A united refinement technology for commercial pure Al by Al-10Ti and Al-Ti-C master alloys

International Nuclear Information System (INIS)

Ma Xiaoguang; Liu Xiangfa; Ding Haimin

2009-01-01

Because flake-like TiAl 3 particles in Al-Ti-C master alloys prepared in a melt reaction method dissolve slowly when they are added into Al melt at 720 deg. C, Ti atoms cannot be released rapidly to play the assistant role of grain refinement, leading to a poor refinement efficiency of Al-Ti-C master alloys. A united refinement technology by Al-10Ti and Al-Ti-C master alloys was put forward in this paper. The rational combination of fine blocky TiAl 3 particles in Al-10Ti and TiC particles in Al-Ti-C can improve the nucleation rate of α-Al. It not only improves the grain refinement efficiency of Al-Ti-C master alloys, but also reduces the consumption

Subjetivación de la experiencia violenta en el transtorno por estrés postraumático

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Oscar Alfredo Muñiz

2005-12-01

Full Text Available A través de este estudio, se buscó establecer el estado de SaludMental de las personas víctimas de violencia armada en el Departamentodel Chocó (Colombia. Específicamente se buscó comprenderel modo en que se ha subjetivado o ha sido integradapsíquicamente la experiencia violenta. La metodología es el deestudio de caso. El estudio es particularista y descriptivo se basó enel razonamiento inductivo a partir del manejo de datos que para elcaso provienen de entrevistas clínicas puesta al servicio de lainvestigación. La mirada cualitativa del problema indica que elnarcisismo protege al sujeto de la experiencia de muerte realimplicado en el trauma por violencia, la lógica paranoide se estableceen relación al Otro, y el repliegue sobre el núcleo familiar se dacomo consecuencia de estos dos aspectos.

Strategy and technologies for the air pollution active control: The MONIQA system; Estrategia y tecnologias para el control activo de la contaminacion del aire: El sistema MONIQA

Energy Technology Data Exchange (ETDEWEB)

Sozzi, Roberto; Favaron, Maurizio [Servizi Territorio, Cinisello Balsamo, (Italy)

1997-12-31

What all the environmental laws of the various nations manifest is to permit a harmonic economical development without creating problems to the environment. This paper states that in order to achieve the former it is needed first to know the air pollution, second, the understanding of the transport phenomena and the dispersion of the pollutants in the air, and third the air pollution control. To confront in an effective manner the air pollution problems it is proposed the use of the MONIQA System. This system will aid the designer, the authorities and the population to respond to their questions in a fast and quick manner [Espanol] Lo que expresan todas las leyes ambientales de las diferentes naciones es permitir un desarrollo economico armonico sin crear problemas al medio ambiente. Esta ponencia propone que para lograr lo anterior es necesario primero el conocimiento de la contaminacion atmosferica, segundo la comprension de los fenomenos del transporte y de la dispersion de los contaminantes en el aire y tercero, el control de la contaminacion del aire. Para confrontar de manera eficaz los problemas de contaminacion atmosferica se propone el uso del sistema MONIQA. Este sistema ayudara a los proyectistas, autoridades y a la poblacion a responder sus preguntas de manera rapida y veloz

Strategy and technologies for the air pollution active control: The MONIQA system; Estrategia y tecnologias para el control activo de la contaminacion del aire: El sistema MONIQA

Energy Technology Data Exchange (ETDEWEB)

Sozzi, Roberto; Favaron, Maurizio [Servizi Territorio, Cinisello Balsamo, (Italy)

1996-12-31

What all the environmental laws of the various nations manifest is to permit a harmonic economical development without creating problems to the environment. This paper states that in order to achieve the former it is needed first to know the air pollution, second, the understanding of the transport phenomena and the dispersion of the pollutants in the air, and third the air pollution control. To confront in an effective manner the air pollution problems it is proposed the use of the MONIQA System. This system will aid the designer, the authorities and the population to respond to their questions in a fast and quick manner [Espanol] Lo que expresan todas las leyes ambientales de las diferentes naciones es permitir un desarrollo economico armonico sin crear problemas al medio ambiente. Esta ponencia propone que para lograr lo anterior es necesario primero el conocimiento de la contaminacion atmosferica, segundo la comprension de los fenomenos del transporte y de la dispersion de los contaminantes en el aire y tercero, el control de la contaminacion del aire. Para confrontar de manera eficaz los problemas de contaminacion atmosferica se propone el uso del sistema MONIQA. Este sistema ayudara a los proyectistas, autoridades y a la poblacion a responder sus preguntas de manera rapida y veloz

Leaping shampoo glides on a 500-nm-thick lubricating air layer

Science.gov (United States)

Li, Erqiang; Lee, Sanghyun; Marston, Jeremy; Bonito, Andrea; Thoroddsen, Sigurdur

2013-11-01

When a stream of shampoo is fed onto a pool in one's hand, a jet can leap sideways or rebound from the liquid surface in an intriguing phenomenon known as the Kaye effect. Earlier studies have debated whether non-Newtonian effects are the underlying cause of this phenomenon, making the jet glide on top of a shear-thinning liquid layer, or whether an entrained air layer is responsible. Herein we show unambiguously that the jet slides on a lubricating air layer [Lee et al., Phys. Rev. E 87, 061001 (2013)]. We identify this layer by looking through the pool liquid and observing its rupture into fine micro-bubbles. The resulting micro-bubble sizes suggest that the thickness of this air layer is around 500 nm. This thickness estimate is also supported by the tangential deceleration of the jet during the rebounding, with the shear stress within the thin air layer sufficient for the observed deceleration. Particle tracking within the jet shows uniform velocity, with no pronounced shear, which would be required for shear-thinning effects. The role of the surfactant may primarily be to stabilize the air film.

Comportamiento del gel de sílice como filtro deshumidificador en sistemas de acondicionamiento de aire por compresión de vapor

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Antonio José Bula Silvera

2004-01-01

Full Text Available Con el fin de determinar la tasa de adsorción de humedad por un filtro a base de gel de sílice, se han llevado a cabo una serie de experimentos en los cuales se ha variado la densidad de gel de sílice por unidad de área y la velocidad con que el aire se acerca al filtro. Los resultados mostraron que al disminuir la velocidad del aire y al aumentar la masa de desecante por unidad de área, se consigue mayor nivel de adsorción por parte del filtro. Sin embargo, al adimensionar la cantidad de agua retenida por unidad de masa de desecante, se observa que el filtro con menor densidad presenta mayor efectividad en el proceso de remoción de humedad. Los resultados se presentan en función del tiempo en un lapso de 50 minutos de muestreo.

Liquidus projection of the Nb-Cr-Al system near the Al3(Nb,Cr) + Cr(Al,Nb) eutectic region

International Nuclear Information System (INIS)

Souza, S.A.; Ferrandini, P.L.; Nunes, C.A.; Coelho, A.A.; Caram, R.

2006-01-01

The system Nb-Cr-Al was investigated in the region near the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic and the liquidus projection of that region was determined based on the microstructural characterization of arc melted alloys. The characterization utilized scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results allowed one to determine three primary solidification liquidus surfaces ((Cr,Al) 2 Nb, Cr(Al,Nb) and Al 3 (Nb,Cr)), that are originated from the binary systems Cr-Nb, Cr-Al and Al-Nb. It is proposed the occurrence of the invariant reaction L + (Cr,Al) 2 Nb ↔ Al 3 (Nb,Cr) + Cr(Al,Nb) and of a point of minimum, which involves a three phase reaction, L ↔ Al 3 (Nb,Cr) + Cr(Al,Nb). All alloys studied showed formation of the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic as the last solidification step with Al(Nb)Cr 2 precipitating from Cr(Al,Nb)

Characteristics of hydrogen co-doped ZnO : Al thin films

International Nuclear Information System (INIS)

Lee, S H; Lee, T S; Lee, K S; Cheong, B; Kim, W M; Kim, Y D

2008-01-01

ZnO films co-doped with H and Al (HAZO) were prepared by sputtering ZnO targets containing 1 wt% Al 2 O 3 on Corning glass at a substrate temperature of 150 deg. C with Ar and H 2 /Ar gas mixtures. The effects of hydrogen addition to Al-doped ZnO (AZO) films with low Al content on the electrical, the optical and the structural properties of the as-grown films as well as the vacuum- and air-annealed films were examined. Secondary ion mass spectroscopy analysis showed that the hydrogen concentration increased with increasing H 2 in sputter gas. For the as-deposited films, the free carrier number increased with increasing H 2 . The Hall mobility increased at low hydrogen content, reaching a maximum before decreasing with a further increase of H 2 content in sputter gas. Annealing at 300 deg. C resulted in the removal of hydrogen, causing a decrease in the carrier concentration. It was shown that hydrogen might exist as single isolated interstitial hydrogen bound with oxygen, thereby acting like an anionic dopant. Also, it was shown that the addition of hydrogen to ZnO films doped with low metallic dopant concentration could yield transparent conducting films with very low absorption loss as well as with proper electrical properties, which is suitable for thin film solar cell applications

A united refinement technology for commercial pure Al by Al-10Ti and Al-Ti-C master alloys

Energy Technology Data Exchange (ETDEWEB)

Ma Xiaoguang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Liu Xiangfa [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)], E-mail: xfliu@sdu.edu.cn; Ding Haimin [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)

2009-03-05

Because flake-like TiAl{sub 3} particles in Al-Ti-C master alloys prepared in a melt reaction method dissolve slowly when they are added into Al melt at 720 deg. C, Ti atoms cannot be released rapidly to play the assistant role of grain refinement, leading to a poor refinement efficiency of Al-Ti-C master alloys. A united refinement technology by Al-10Ti and Al-Ti-C master alloys was put forward in this paper. The rational combination of fine blocky TiAl{sub 3} particles in Al-10Ti and TiC particles in Al-Ti-C can improve the nucleation rate of {alpha}-Al. It not only improves the grain refinement efficiency of Al-Ti-C master alloys, but also reduces the consumption.

Numerical simualtions and implications of air inclusions on the microdynamics of ice and firn

Science.gov (United States)

Steinbach, Florian; Weikusat, Ilka; Bons, Paul; Griera, Albert; Kerch, Johanna; Kuiper, Ernst-Jan; Llorens-Verde, Maria-Gema

2016-04-01

Although ice sheets are valuable paleo-climate archives, they can loose their integrity by ice flow (Faria et al. 2010). Consequently, understanding the dynamic processes that control the flow of ice is essential when investigating the past and future climate. While recent research successfully modelled the microdynamics of pure ice (e.g. Montagnat et al., 2014; Llorens et al., 2015), work taking into account second phases is scarce. Only a few studies also show the microstructural influence of air inclusions (Azuma et al., 2012, Roessiger et al., 2014). Therefore, modelling was performed focussing on the implications of the presence of bubbles on the microdynamical mechanisms and microstructure evolution. The full-field theory crystal plasticity code (FFT) of Lebensohn (2001), was coupled to the 2D multi-process modelling platform Elle (Bons et al., 2008), following the approach by Griera et al. (2013). FFT calculates the viscoplastic response of polycrystalline materials deforming by dislocation glide, taking into account mechanical anisotropy. The models further incorporate surface- and stored strain energy driven grain boundary migration (GBM) and intracrystalline recovery simulating annihilation and rearrangement of dislocations by reduction of internal misorientations. GBM was refined for polyphase materials following Becker et al. (2008) and Roessiger et al. (2014). Additionally, the formation of new high angle grain boundaries by nucleation and polygonisation based on critical internal misorientations has been implemented. Successively running the codes for different processes in very short numerical timesteps effectively enables multi-process modelling of deformation and concurrent recrystallisation. Results show how air inclusions control and increase strain localisation, leading to locally enhanced dynamic recrystallisation. This is in compliance with Faria et al. (2014), who theoretically predicted these localizations based on firn data from EPICA

La neolitización del nordeste de la Península Ibérica: datos radiocarbónicos y culturales de los asentamientos al aire libre del Penedès

Directory of Open Access Journals (Sweden)

Oms, F. Xavier

2014-06-01

Full Text Available The work now presented puts forward new data on three open-air sites located in Penedès (Barcelona, Catalan Coastal Depression with Early Neolithic occupation phases: the settlement of Les Guixeres de Vilobí and the pit complexes of La Serreta and Mas d’en Boixos. The sites’ pottery assemblages were analyzed and, for the first time, 5 short-lived samples were radiocarbon dated to collaborate in the discussion of the current knowledge on the Early Neolithic of NE Iberia and the broader Western Mediterranean. It suggests this area played an important role during the earliest phases of the Neolithic together with other key areas such as the Llobregat valley or the Alicante region. The chronology obtained enabled us to discuss the earliest Neolithic of the Iberian Peninsula.En este trabajo se presentan datos inéditos acerca de tres asentamientos al aire libre situados en el llano prelitoral del Penedès (Barcelona con ocupaciones del Neolítico inicial: el hábitat de Les Guixeres de Vilobí y las agrupaciones de silos-fosas de La Serreta y el Mas d’en Boixos. Se estudian sus materiales cerámicos y 5 fechas radiocarbónicas inéditas en el marco de la discusión sobre el Neolítico antiguo del nordeste de la Península Ibérica y de la neolitización del Mediterráneo occidental. Se propone que esta zona fue clave y con cierta densidad poblacional durante las primeras fases neolíticas y comparable a enclaves emblemáticos como el cercano valle del Llobregat (Garraf-llano de Barcelona y Vallès o la zona alicantina. La antigüedad de las fechas obtenidas aporta nuevos datos al debate acerca del primer neolítico en la Península Ibérica.

EL ITINERARIO COMO HERRAMIENTA PARA LA PUESTA EN VALOR TURÍSTICO DEL PATRIMONIO TERRITORIAL

Directory of Open Access Journals (Sweden)

Alfonso M. Doctor

2011-01-01

Full Text Available Se presentan los antecedentes, desarrollo y avance de resultados del proyecto de investigación «Articulación de los recursos patrimoniales turísticos y aplicación de la tecnología SIG a su planificación y gestión» (Proyecto A/017070/08, financiado durante las anualidades 2009 y 2010 por la Agencia Española de Cooperación Internacional al Desarrollo, AECID, del Ministerio de Asuntos Exteriores, desarrollado por un equipo conjunto de las universidades Austral de Chile, Católica de Salta (Argentina, Guadalajara (México, Pablo de Olavide, Sevilla y Huelva (España.

Voces [en la cabeza]: espacialidad, mediaciones teletecnológicas y las verdades caleidoscópicas en el proceso de Justicia y Paz en Colombia

Directory of Open Access Journals (Sweden)

Alejandro Castillejo-Cuéllar

2013-03-01

Full Text Available Este texto explora —en el contexto del proceso instaurado por la puesta en marcha de la llamada Ley de Justicia y Paz en Colombia, encargada de administrar “la reincorporación de miembros de grupos armados organizados al margen de la ley”— un espacio legal concreto en el que miembros desmovilizados de las Autodefensas Unidas de Colombia confiesan los actos delictivos que realizaron durante su “pertenencia” al grupo ante un Fiscal Especial de Justicia y Paz. A esta diligencia se le llama técnicamente audiencia de versión libre. Este documento hace parte de una investigación más amplia realizada en diferentes escenarios nacionales sobre lo que llamaría los espacios de la ley, particularmente, en el contexto de la aplicación de leyes transicionales. Así, el documento se concentra, primero, en lo que llamaría una antropología de la ley y la cotidianidad, para mostrar algunos de los elementos que definen la puesta en escena de la versión libre. Segundo, en dicha cotidianidad, pero en el caso específico de seres queridos que usan el proceso de Justicia y Paz para encontrar a sus parientes desaparecidos. Este proceso, donde se vinculan mediaciones auditivas, visuales y orales, produce lo que llamo “verdades caleidoscópicas”, donde fragmentos de historias, lugares y hechos son “unificados” a veces de manera precaria, para formar una imagen del pasado.

United modification of Al-24Si alloy by Al-P and Al-Ti-C master alloys

Institute of Scientific and Technical Information of China (English)

韩延峰; 刘相法; 王海梅; 王振卿; 边秀房; 张均艳

2003-01-01

The modification effect of a new type of Al-P master alloy on Al-24Si alloys was investigated. It is foundthat excellent modification effect can be obtained by the addition of this new type of A1-P master alloy into Al-24Simelt and the average primary Si grain size is decreased below 47 μm from original 225 μm. It is also found that theTiC particles in the melt coming from Al8Ti2C can improve the modification effect of the Al-P master alloy. Whenthe content of TiC particles in the Al-24Si melt is 0.03 %, the improvement reaches the maximum and keeps steadywith increasing content of TiC particles. Modification effect occurs at 50 min after the addition of the Al-P master al-loy and TiC particles, and keeps stable with prolonging holding time.

Nanoporous Al sandwich foils using size effect of Al layer thickness during Cu/Al/Cu laminate rolling

Science.gov (United States)

Yu, Hailiang; Lu, Cheng; Tieu, A. Kiet; Li, Huijun; Godbole, Ajit; Kong, Charlie

2018-06-01

The roll bonding technique is one of the most widely used methods to produce metal laminate sheets. Such sheets offer interesting research opportunities for both scientists and engineers. In this paper, we report on an experimental investigation of the 'thickness effect' during laminate rolling for the first time. Using a four-high multifunction rolling mill, Cu/Al/Cu laminate sheets were fabricated with a range of thicknesses (16, 40, 70 and 130 μm) of the Al layer. The thickness of the Cu sheets was a constant 300 μm. After rolling, TEM images show good bonding quality between the Cu and Al layers. However, there are many nanoscale pores in the Al layer. The fraction of nanoscale pores in the Al layer increases with a reduction in the Al layer thickness. The finite element method was used to simulate the Cu/Al/Cu rolling process. The simulation results reveal the effect of the Al layer thickness on the deformation characteristics of the Cu/Al/Cu laminate. Finally, we propose that the size effect of the Al layer thickness during Cu/Al/Cu laminate rolling may offer a method to fabricate 'nanoporous' Al sandwich laminate foils. Such foils can be used in electromagnetic shielding of electrical devices and noisy shielding of building.

Comparison between PIII superficial treatment and ceramic coating in creep test of Ti-6Al-4V alloy

International Nuclear Information System (INIS)

Reis, D.A.P.; Moura Neto, C.; Silva, M.M.; Ueda, M.; Oliveira, V.S.; Couto, A.A.