Fabrication and evaluation of NiO/Y2O3-stabilized-ZrO2 hollow fibers for anode-supported micro-tubular solid oxide fuel cells

In this work NiO/3mol% Y₂O₃-ZrO₂ (3YSZ) and NiO/8mol% Y₂O₃-ZrO₂ (8YSZ) hollow fibers were prepared by phase-inversion. The effect of different kinds of YSZ (3YSZ and 8YSZ) on the porosity, electrical conductivity, shrinkage and flexural strength of the hollow fibers were systematically evaluated. When compared with Ni-8YSZ the porosity and shrinkage of Ni-3YSZ hollow fibers increases while the electrical conductivity decreases, while at the same time also exhibiting enhanced flexural strength. Single cells with Ni-3YSZ and Ni-8YSZ hollow fibers as the supported anode were successfully fabricated showing maximum power densities of 0.53 and 0.67Wcm^-2 at 800°C, respectively. Furthermore, in order to improve the cell performance, a Ni-8YSZ anode functional layer was added between the electrolyte and Ni-YSZ hollow fiber. Here enhanced peak power densities of 0.79 and 0.73Wcm^-2 were achieved at 800°C for single cells with Ni-3YSZ and Ni-8YSZ hollow fibers, respectively.

High performance cobalt-free Cu1.4Mn1.6O4 spinel oxide as an intermediate temperature solid oxide fuel cell cathode

In this work Cu_1.4Mn_1.6O₄ (CMO) spinel oxide is prepared and evaluated as a novel cobalt-free cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). Single phase CMO powder with cubic structure is identified using XRD. XPS results confirm that mixed Cu⁺/Cu²⁺ and Mn³⁺/Mn⁴⁺ couples exist in the CMO sample, and a maximum conductivity of 78 S cm⁻¹ is achieved at 800 °C. Meanwhile, CMO oxide shows good thermal and chemical compatibility with a 10 mol% Sc₂O₃ stabilized ZrO₂ (ScSZ) electrolyte material. Impedance spectroscopy measurements reveals that CMO exhibits a low polarization resistance of 0.143 Ω cm² at 800 °C. Furthermore, a Ni-ScSZ/ScSZ/CMO single cell demonstrates a maximum power density of 1076 mW cm⁻² at 800 °C under H₂ (3% H₂O) as the fuel and ambient air as the oxidant. These results indicate that Cu_1.4Mn_1.6O₄ is a superior and promising cathode material for IT-SOFCs.

Fabrication and characterization of SSZ tape cast electrolyte-supported solid oxide fuel cells

A 10 mol%Sc₂O₃, 1 mol%CeO₂ stabilized-ZrO₂ (SSZ) powder was successfully prepared using the sol-gel method. Subsequent SSZ electrolyte pellets were prepared by tape casting technique and sintered at 1400 °C, 1450 °C, 1500 °C, 1550 °C and 1600 °C. These were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). SSZ showed a pure cubic phase after sintering, the grain size of SSZ increased with the increase of sintering temperature. The SSZ sintered at 1550 °C showed the highest ion conductivity. The maximum power densities of Ni-SSZ/SSZ/La_0.8Sr_0.2MnO_3-δ (LSM)-SSZ single cells sintered at 1550 °C were 0.18, 0.36, 0.51 and 0.72 W cm^-2 at 650, 700, 750 and 800 °C, respectively. The polarization resistance (R_p) of the single cell attained 0.201 Ω cm² at 800 °C.

Improved electrochemical performance of Sr2Fe1.5Mo0.4Nb0.1O6-δ -Sm0.2Ce0.8O2-δ composite cathodes by a one-pot method for intermediate temperature solid oxide fuel cells

In this paper, Sr₂Fe_1.5Mo_0.4Nb_0.1O_6-δ (SFMNb)-xSm_0.2Ce_0.8O_2-δ (SDC) (x = 0, 20, 30, 40, 50 wt%) composite cathode materials were synthesized by a one-pot combustion method to improve the electrochemical performance of SFMNb cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The fabrication of composite cathodes by adding SDC to SFMNb is conducive to providing extended electrochemical reaction zones for oxygen reduction reactions (ORR). X-ray diffraction (XRD) demonstrates that SFMNb is chemically compatible with SDC electrolytes at temperature up to 1100 °C. Scanning electron microscope (SEM) indicates that the SFMNb-SDC composite cathodes have a porous network nanostructure as well as the single phase SFMNb. The conductivity and thermal expansion coefficient of the composite cathodes decrease with the increased content of SDC, while the electrochemical impedance spectra (EIS) exhibits that SFMNb-40SDC composite cathode has optimal electrochemical performance with low polarization resistance (R_p) on the La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ electrolyte. The R_p of the SFMNb-40SDC composite cathode is about 0.047 Ω cm² at 800 °C in air. A single cell with SFMNb-40SDC cathode also displays favorable discharge performance, whose maximum power density is 1.22 W cm^-2 at 800 °C. All results indicate that SFMNb-40SDC composite material is a promising cathode candidate for IT-SOFCs.

Treatment of phenanthrene and benzene using microbial fuel cells operated continuously for possible in situ and ex situ applications

Bioelectrochemical systems could have potential for bioremediation of contaminants either in situ or ex situ. The treatment of a mixture of phenanthrene and benzene using two different tubular microbial fuel cells (MFCs) designed for either in situ and ex situ applications in aqueous systems was investigated over long operational periods (up to 155 days). For in situ deployments, simultaneous removal of the petroleum hydrocarbons (>90% in term of degradation efficiency) and bromate, used as catholyte, (up to 79%) with concomitant biogenic electricity generation (peak power density up to 6.75 mWm−2) were obtained at a hydraulic retention time (HRT) of 10 days. The tubular MFC could be operated successfully at copiotrophic (100 ppm phenanthrene, 2000 ppm benzene at HRT 30 days) and oligotrophic (phenanthrene and benzene, 50 ppb each, HRT 10 days) substrate conditions suggesting its effectiveness and robustness at extreme substrate concentrations in anoxic environments. In the MFC designed for ex situ deployments, optimum MFC performance was obtained at HRT of 30 h giving COD removal and maximum power output of approximately 77% and 6.75 mWm−2 respectively. The MFC exhibited the ability to resist organic shock loadings and could maintain stable MFC performance. Results of this study suggest the potential use of MFC technology for possible in situ/ex situ hydrocarbon-contaminated groundwater treatment or refinery effluents clean-up, even at extreme contaminant level conditions.

Long-Term Care Options, March 26, 2015

Information on when and how best to explore Long-Term Care options on a power point presentation.

The phase diagram of the mercury-indium alloy system

The mercury-indium phase diagram has been investigated over the whole composition range from -78°C to the melting point of indium, using thermal analysis, X-ray and superconductivity techniques. This is believed to be the first application of superconductivity measurements to phase diagram investigations. A compound, HgIn, of very limited range of composition, melts congruently at -19.3°C; and gives rise to eutectics at 61.5 at. % indium and -31°C, and at 34.7% indium and -37.2°C. The β phase extends from 2.5 to 19.1 % indium and has a maximum melting point of -14.2°C at 14.2% indium. It forms a peritectic or eutectic at a temperature indistinguishable from the melting point of pure mercury with a solid solution in mercury containing some, but less than 0.3%, indium. A transition from face-centred tetragonal to face-centred cubic in the indium-rich solid solutions at about 93% indium gives rise to a peritectic at 108°C. The solubility of mercury in this face-centred cubic phase falls from about 22% at-31°C to 13% at -78°C. © 1963.

Libro electrónico de superficies y volúmenes para décimo año

En los últimos años ha aumentado el deterioro del medio ambiente causado por la contaminación doméstica e industrial, dañando el aire, el agua y el suelo; afectando la vida de los seres vivos y causando enfermedades. Queremos llegar a los educandos ha que tomen conciencia, se sensibilicen, apliquen alternativas de control de la contaminación y sean multiplicadores de la información, para ello se ha elaborado un material audiovisual, en Power Point con información sencilla, actual, de fácil comprensión sobre los causas y efectos que produce la contaminación producida por el Parque Industrial de Cuenca

Implementación de estrategias innovadoras apoyadas en las TIC´S para el aprendizaje de las matemáticas del bloque número uno del segundo año de bachillerato general unificado en la Unidad Educativa Zoila Esperanza Palacios

Este trabajo consistió en el diseño, la implementación, validación y verificación de estrategias innovadoras para el proceso enseñanza-aprendizaje de los contenidos matemáticos del bloque número 1 del 2do año de bachillerato de la U. E. Zoila Esperanza Palacios, mediante el uso de las TIC´s. Se trabajó con dos paralelos para posteriormente poder hacer la comparación respectiva de los logros alcanzados, en las clases se implementaron estrategias previamente diseñadas, utilizando recursos informáticos como: Sitios web con animaciones de formato ¨swf¨, plataforma online THATQUIZ, Algebrator, GeoGebra, videos y Microsoft: Power Point. Lo anterior se logró mediante la propuesta de una ¨Guía Didáctica Para el Docente¨, que incluye las estrategias diseñadas, además a esto se elaboró la planificación micro curricular del bloque número 1. También se elaboraron y aplicaron encuestas para realizar una contextualización del grupo con el que se trabajó, y una segunda encuesta para determinar el nivel de satisfacción de software utilizado. La verificación del impacto de la aplicación de las estrategias propuestas se realizó de la siguiente manera: 1. Obtención y análisis de las notas obtenidas por los 2 paralelos en el primer bloque el año lectivo 2013-2014. 2. Obtención y análisis de las notas obtenidas por los dos paralelos en el primer bloque el año lectivo (2014-2015) 3. Comparación de los análisis obtenidos. 4. Aplicación y análisis de resultados de encuestas de contextualización y satisfacción de software al paralelo intervenido.

La focalización de la pobreza versus la construcción de capacidades ciudadanas: El dilema de los Comedores Comunitarios de Ciudad Bolívar

El interés de esta investigación diagnóstica es establecer la incidencia de la focalización de la pobreza en la construcción de capacidades ciudadanas de los usuarios de los Comedores Comunitarios de Ciudad Bolívar. Se identifica y analiza cómo los mecanismos de focalización aún cuando permiten que se implemente la política pública de Seguridad Alimentaria dentro de esta localidad, limitan el escenario de construcción de capacidades ciudadanas, en tanto que convierten al usuario en un sujeto de la política asistencial que carece de libertades para superar su condición de pobreza. Este ejercicio diagnóstico se apoya en la teoría de libertades y capacidades de Amartya Sen para su diseño metodológico, así como también para el análisis de la información obtenida en el marco de esta investigación.

Reflexiones sobre la ética en el actuar de los servidores públicos en Colombia desde 1991 hasta la actualidad

El presente estado del arte se propone abordar lo concerniente a la ética en las actuaciones de los servidores públicos en Colombia, mediante una revisión exhaustiva de la literatura pertinente que existe del tema, así como de las distintas normas regulatorias y documentos oficiales que versan sobre los servidores públicos. De esta manera, se hará especial énfasis en los cambios que ha tenido la organización, el funcionamiento y el control de quienes sirven al Estado colombiano desde la instauración de la actual Constitución Política de 1991. En consecuencia, se encontrarán algunas reflexiones sobre el tema, las cuales provienen de la investigación y de entrevistas realizadas a servidores públicos.

Oportunidades en los mercados de Nueva York, Nueva Jersey y Nebraska para las empresas colombianas

Actualmente, las barreras comerciales a nivel internacional resultan cada vez menos tangibles entre los diferentes mercados, haciendo que las oportunidades de comercialización de bienes y servicios entre países sea cada vez mayor. Sin embargo, es muy común todavía encontrarse con historias de fracaso en los esfuerzos de diferentes empresarios medianos y pequeños que en su momento decidieron emprender el camino de la internacionalización de sus compañías y que por diferentes factores, bien sea desconocimiento de leyes comerciales internacionales, desinformación primordial del mercado objetivo o simplemente por situaciones ajenas a ellos sufrieron esta adversidad y dejaron de lado su impulso e interés por internacionalizarse. Por tal razón, hemos enfocado nuestros esfuerzos en tratar de identificar las diferentes potencialidades y oportunidades que el empresario colombiano puede llegar a tener en cuatro estados de Estados Unidos de Norteamérica, Nueva York, Nueva Jersey, Nuevo Hampshire y Nebraska específicamente. La metodología a desarrollar a lo largo de esta investigación principalmente recoge información cualitativa y cuantitativa que nos permitirá desglosar diversos aspectos con mayor profundidad, para que el empresario interesado tenga un panorama más claro de lo que puede llegar a encontrarse en los estados mencionados anteriormente.

Materiais electrocrómicos e mecaelectroquímicos: contextualização e experimentação na disciplina de química do 12º ano

Durante os últimos 1O anos, em particular, tem-se assistido à descoberta e desenvolvimento de materiais com propriedades únicas e potencialmente úteis em vários domínios da Ciência e Tecnologia. Quer seja na área das Ciências Biomédicas e do Ambiente, na área das Novas Tecnologias de Informação e Comunicação ou nas Novas Tecnologias relacionadas com sistemas de Conversão e Armazenamento de Energia Eléctrica, encontram-se inúmeros exemplos de Novos Materiais com propriedades muito interessantes, e cujas aplicações inovadoras podem revolucionar o nosso Mundo. O presente trabalho é uma proposta de contextualização e experimentação do tema "Materiais Electrocrómicos e Mecaelectroquímicos" no Programa de Química de 12° Ano, nomeadamente na terceira Unidade - Plásticos, Vidros e Novos Materiais. Neste, é apresentada uma sub-unidade que possa integrar a unidade referida. Faz-se especial referência às aplicações dos polímeros condutores, que pela sua inovação e actualidade tomam a leccionação do tema mais apelativa, interessante e facilitadora de uma literacia científica. São apresentadas experiências laboratoriais demonstrativas e elucidativas do tema em questão. Como forma de apoiar a leccionação do referido tema, é apresentada a proposta de uma animação gráfica animada em Power Point. ABSTRACT: During the past 1O years, in particular, it has witnessed to the discovery and development of materials with unique properties and potentially useful in various fields of Science and Technology. There are numerous examples of new materials in different areas, such as Biomedical, Energy and Environmental Sciences and New information and Communication Technologies, with very interesting properties, and whose innovative applications can have an outstanding impact in our world. This dissertation is a proposal of contextualization and experimentation of theme "Electrochromic Materials and Electrochemical Artificial Muscles" in the Program of Chemistry, in 12th year, particularly in the third unit - Plastics, Glass and New Materials. lt will present a sub-unit that can integrate the unit above. The definitions and some applications of the Electrochromic Materials and Electrochemical Artificial Muscles are showed. Demonstrative and illustrative laboratory experiments of the theme are proposed. ln order to support the teaching of that subject, it is presented an animated graphical presentation in Power Point.

Violência contra o idoso

Aula em Power point narrada na qual são elucidadas as situações de violência domésticas contra o idoso, onde se reconhecem os indicadores da violência contra o idoso, com o conhecimento da legislação pertinente e do conhecimento das redes de apoio, proporcionando uma visão mais ampla ao profissional de saúde da APS.

Violência Doméstica

Aula em Power point narrada na qual são elucidadas as situações de violência domésticas, explicando a Lei Maria da Penha e as principais áreas de atuação do profissional da saúde.