997 resultados para 6-BA


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2009

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W artykule został przeanalizowany dyskurs bałkański XX wieku z kolonialnego i postkolonialnego punktu widzenia. Pierwsza część przybliża geopolityczny stosunek do Bałkanów,The Balans in the Gaze of Western Travellers (2004) jako przykłady korygującego wobec istniejących dotychczas reprezentacji i wyobrażeń Bałkanów. skupia się jednak nie tylko na nazwie geograficznej Półwysep Bałkański, lecz przede wszystkim na figuratywnym i metaforycznym języku, bazującym na stereotypach i negatywnych „etykietkach” Bałkanów, takich jak: „beczka prochu”, obszar „zadawnionej nienawiści”, „zderzenie cywilizacji”, „strefa rozłamu”, europejskie „jądro ciemności”, „dzika Europa”, „jeszcze- nie” Europa. Ten stosunek opiera się na opozycji My-Oni z kolonialnego, punktu widzenia Zachodu. W drugiej części tekstu zostaje przeprowadzona analiza trzech utworów prozatorskich autorstwa wybitnych pisarzy z Bałkanów – chorwacki dyskurs literacki jest reprezentowany przez Miroslava Krležę w opowiadaniu W Dreźnie. Mister Wu San Pej interesuje się problemem serbsko-chorwackim (1924), serbski dyskurs przedstawia Ivo Andrić w opowiadaniu List z roku 1920 (1946), natomiast bośniacki – Nenad Veličković i jego powieść epistolarna Sahib. Impresje z depresji (2001). Te trzy dyskursy z różnych przełomowych dla Jugosławii okresów pokazują, że pisarze chętnie sięgali po figurę „Obcego”, by uwypuklić problemy związane z własną złożoną, często zwielokrotnioną tożsamością. Ostatnia część akcentuje nowe, postkolonialne podejście do problemu Bałkanów – uczestniczą w nim wybitni naukowcy pochodzący z tego regionu, którzy zrobili kariery w Europie Zachodniej i USA. W tej części zostają zaprezentowane trzy fundamentalne dla tego problemu książki – studium Marii Todorowej (Bułgarka) Imagining the Balkans (1997), monografia Vesny Bjelogrlić-Goldsworthy (Serbka) Inventing Ruritania: The Imperializm of the Imagination (1998) oraz antropologiczna książka Božidara Jezernika (Słoweniec) Wild Europe.

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For the first time, the coupling of fast transient kinetic switching and the use of an isotopically labelled reactant (15NO) has allowed detailed analysis of the evolution of all the products and reactants involved in the regeneration of a NOx storage reduction (NSR) material. Using realistic regeneration times (ca. 1 s) for Pt, Rh and Pt/Rh-containing Ba/Al2O3 catalysts we have revealed an unexpected double peak in the evolution of nitrogen. The first peak occurred immediately on switching from lean to rich conditions, while the second peak started at the point at which the gases switched from rich to lean. The first evolution of nitrogen occurs as a result of the fast reaction between H2 and/or CO and NO on reduced Rh and/or Pt sites. The second N2 peak which occurs upon removal of the rich phase can be explained by reaction of stored ammonia with stored NOx, gas phase NOx or O2. The ammonia can be formed either by hydrolysis of isocyanates or by direct reaction of NO and H2.

The study highlights the importance of the relative rates of regeneration and storage in determining the overall performance of the catalysts. The performance of the monometallic 1.1%Rh/Ba/Al2O3 catalyst at 250 and 350 °C was found to be dependent on the rate of NOx storage, since the rate of regeneration was sufficient to remove the NOx stored in the lean phase. In contrast, for the monometallic 1.6%Pt/Ba/Al2O3 catalyst at 250 °C, the rate of regeneration was the determining factor with the result that the amount of NOx stored on the catalyst deteriorated from cycle to cycle until the amount of NOx stored in the lean phase matched the NOx reduced in the rich phase. On the basis of the ratio of exposed metal surface atoms to total Ba content, the monometallic 1.6%Pt/Ba/Al2O3 catalyst outperformed the Rh-containing catalysts at 250 and 350 °C even when CO was used as a reductant.

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The dielectric properties of BaTiO3 thin films and multilayers are different from bulk materials because of nanoscale dimensions, interfaces, and stress-strain conditions. In this study, BaTiO3/SrTiO3 multilayers deposited on SrTiO3 substrates by pulsed laser deposition have been investigated by high-energy-resolution electron energy-loss spectroscopy. The fine structures in the spectra are discussed in terms of crystal-field splitting and the internal strain. The crystal-field splitting of the BaTiO3 thin layer is found to be a little larger than that of bulk BaTiO3, which has been interpreted by the presence of the internal strain induced by the misfit at the interface. This finding is consistent with the lattice parameters of the BaTiO3 thin layer determined by the selected area diffraction pattern. The near-edge structure of the oxygen K edge in BaTiO3 thin layers and in bulk BaTiO3 are simulated by first-principle self-consistent full multiple-scattering calculations. The results of the simulations are in a good agreement with the experimental results. Moreover, the aggregation of oxygen vacancies at the rough BaTiO3/SrTiO3 interface is indicated by the increased [Ti]/[O] element ratio, which dominates the difference of dielectric properties between BaTiO3 layer and bulk materials.

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BaCe1-xYxO3-δ (BCY) and BaCe0.8-yZryY0.2O3-δ (BCZY) compounds were synthesised via an aqueous sol-gel method and two different calcination processes were tested for BCZY synthesis. The highest hydration capacity was recorded for the compound that contained the highest Y-doping level (x=0.2). Further substitution of Ce4+ by Zr4+ enhanced the chemical stability especially for y≥0.2, although decreased proton conductivity. However, BaCe0.6-0.2Zr0.2Y0.2O2.9 (BCZ20Y20) which presented adequate water uptake and high chemical stability in presence of CO2, was found to be the best candidate compound to be used in applications such as electrocatalytic CO2 hydrogenation.

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Knowledge management theory has struggled with the concept of `knowledge creation'. Since the seminal article of Nonaka in 1991, an industry has grown up seeking to capture the knowledge in the heads and hearts of individuals so as to leverage them for organizational learning and growth. But the process of Socialization, Externalization, Combination and Internalization (SECI) outlined by Nonaka and his colleagues has essentially dealt with knowledge transfer rather than knowledge creation. This paper attempts to fill the gap in the process - from Nonaka's own addition of the need for "ba" to Snowden's suggestion of that we consider "Cynefin" as a space for knowledge creation. Drawing upon a much older theoretical frame - work the Johari Window developed in group dynamics, this paper suggests an alternative concept - latent knowledge - and introduces a different model for the process of knowledge creation.

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Single-phase polycrystalline ceramics in the MO-La2O3-Ti02 (M = Ca, Sr, Ba) system, such as cation-deficient hexagonal perovskites CaLa4Ti4O15, SrLa4Ti4O15, BaLa4Ti4O15, and Ca2La4Ti5O18 and the orthorhombic phases CaLa4Ti5O17 and CaLa8Ti9O31, were prepared through the solid-state ceramic route. The phases and structure of the ceramics were analyzed through x-ray diffraction and scanning electron microscopy. The microwave dielectric properties of the ceramics were studied using a network analyzer. The investigated ceramics show high Er in the range 42 to 54, high quality factors with Q x f in the range 16,222 to 50,215 GHz, and low Tf in the range -25 to +6 ppm3/°C. These high dielectric constant materials with high Q x f up to 50,215 GHz are suitable for applications where narrow bandwidth and extremely low insertion loss is necessary, especially at frequencies around 1.9 GHz

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Microwave dielectric resonators (DRs) based on Ba(B1,2Nbi/2)03 [B' = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Yb, and In] complex perovskites have been prepared by conventional solid state ceramic route. The dielectric properties (relative permittivity, Er; quality factor, Q; and resonant frequency, rr) of the ceramics have been measured in the frequency range 4-6 GHz using resonance methods. The resonators have relatively high dielectric constant in the range 36-45, high quality factor and small temperature variation of resonant frequency. The dielectric properties are found to depend on the tolerance factor (t), ionic radius (r), and lattice parameter (ap)

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La Librer??a Abracadabra de Avil??s colabora con los centros p??blicos de la comarca con la propuesta de un ba??l de libros que recorre las escuelas promoviendo una nueva actividad de fomento de la lectura. Se narra la experiencia, coordinada desde el Centro del Profesorado y de Recursos de Avil??s, y se enlaza al archivo pdf con el listado de los cuentos seleccionados que, en esta ocasi??n, van dirigidos a ni??os de 3 a 6 a??os.

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Se recogen páginas web de interés sobre la hipertensión arterial

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Monográfico con el título: I Jornadas de Educación Infantil 'la emoción de aprender: una visión de la Educación Infantil desde la metodología de proyectos'

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Se analiza la Ley Orgánica de Educación (LOE) a partir de la experiencia personal del profesor Julián Martín Martínez. Se destaca la marcha atrás en la legislación con esta ley y los mecanismos educativos, metodologías y didácticas. Se reflexiona y comparan las dos etapas de Secundaria: la obligatoria y la voluntaria. Por último, se proponen unas soluciones: grupos más pequeños y grupos homogéneos con más divisiones según la competencia académica y la actitud del alumno, por niveles de preparación; libertad organizativa del Centro para establecer grupos, desdobles dentro de un grupo, horas de clase en determinadas materias; que el trabajo-estudio sea decisivo para aprobar contando con la agrupación de los alumnos por niveles; en los pequeños grupos la atención se acompaña con refuerzos y recuperaciones; una prueba externa al finalizar la ESO que para el alumno sea como ganar algo permite subir la calidad y el nivel, motivaría al alumno y homologaría los centros; y la publicación de los resultados de los controles externos, necesaria para dinamizar el sistema.

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In this work, Ba(Zr(0.25)Ti(0.75))O(3) ceramic was prepared by solid-state reaction. This material was characterized by x-ray diffraction and Fourier transform Raman spectroscopy. The temperature dependent dielectric properties were investigated in the frequency range from 1 kHz to 1 MHz. The dielectric measurements indicated a diffuse phase transition. The broadening of the dielectric permittivity in the frequency range as well as its shifting at higher temperatures indicated a relaxor-like behaviour for this material. The diffusivity and the relaxation strength were estimated using the modified Curie-Weiss law. The optical properties were analysed by ultraviolet-visible (UV-vis) absorption spectroscopy and photoluminescence (PL) measurements at room temperature. The UV-vis spectrum indicated that the Ba(Zr(0.25)Ti(0.75))O(3) ceramic has an optical band gap of 2.98 eV. A blue PL emission was observed for this compound when excited with 350 nm wavelength. The polarity as well as the PL property of this material was attributed to the presence of polar [TiO(6)] distorted clusters into a globally cubic matrix.