887 resultados para Transformative reflection


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Organic microcavity light-emitting diodes typically exhibit a blueshift of the emitting wavelength with increasing viewing angle. We have modeled the shift of the resonance wavelength for several metal mirrors. Eight metals (Al, Ag, Cr, Ti, Au, Ni, Pt, and Cu) have been considered as top or bottom mirrors, depending on their work functions. The model fully takes into account the dependence of the phase change that occurs on reflection on angle and wavelength for both s and p polarization, as well as on dispersion in the organic layers. Different contributions to the emission wavelength shift are discussed. The influence of the thickness of the bottom mirror and of the choice and thickness of the organic materials inside the cavity has been investigated. Based on the results obtained, guidelines for a choice of materials to reduce blueshift; are given. (C) 2002 Optical Society of America.

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An equivalent unit cell waveguide approach (WGA) is described to obtain reflection coefficient phase curves for designing a microstrip patch reflectarray supported by a ground plane with periodic apertures or slots. Based on the presented theory, a computer algorithm for determining the reflection coefficient of a plane wave normally incident on a multi-layer structure of patches and apertures is developed. The validity of the developed algorithm is verified by comparing the obtained results with those published in the literature and the ones generated by Agilent High Frequency Structure Simulator (HFSS). A good agreement in all the presented examples is obtained, proving that the developed theory and computer algorithm can be an effective tool for designing multi-layer microstrip reflectarrays with a periodically perforated ground plane. (C) 2003 Wiley Periodicals, Inc.

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An equivalent unit cell waveguide approach (WGA) to designing 4 multilayer microstrip reflectarray of variable size patches is presented. In this approach, a normal incidence of a plane wave on an infinite periodic array of radiating elements is considered to obtain reflection coefficient phase curves for the reflectarray's elements. It is shown that this problem is equivalent to the problem of reflection of the dominant TEM mode in a waveguide with patches interleaved by layers of dielectric. This waveguide problem is solved using a field matching technique and a method of moments (MoM). Based on this solution, a fast computer algorithm is developed to generate reflection coefficient phase curves for a multilayer microstrip patch reflectarray. The validity of the developed algorithm is tested against alternative approaches and Agilent High Frequency Structure Simulator (HFSS). Having confirmed the validity of the WGA approach, a small offset feed two-layer microstrip patch array is designed and developed. This reflectarray is tested experimentally and shows good performance.

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Like those in other sectors, managers in community-based organisations face an uncertain and challenging future. Research and writing about the community sector (non-government, notjor-profit, or third seclOr) has canvassed a wide range of issues. A selective review of the recent literature reveals the breadth of research interest in the challenges facing community sector managers. While some reflection on the implications for managers of current economic and social policy contexts is crucial for this sector, research effort needs to be focused on understanding how third sector managers construe their current strategic challenges and the strategies they use to address them A small sample ofmanagers working in a regional area in South East Queensland was asked to identify current strategic concerns related to the future viability of their organisations. The key issues raised by managers are compared with the issues raised in the research literature. Results -to date indicate that managers' concerns are reflected in the research literature, but that managers are also concemed about the current trends in social policy towards collaboration, amalgamation, and pannership. Implications of these findings for managers operating in this sector are discussed.

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This discussion argues the transformative potential inherent in the corporeal experience of motherhood as represented in selected textual moments of Japanese narrative. Narratives that address the experiences of the body of the mother are informed and given substance by an intense physicality, and thus have the potential to contest processes of social inscription in addition to suggesting alternative possibilities for all readers, not just those occupying an embodied maternal space. The discussion features brief events from the work of three writers who have written as mothers: Tsushima Y(u)macrko, Ariyoshi Sawako and Enchi Fumiko. In Yama o hashiru onna (1980; translated as Woman Running in the Mountains, 1991), Tsushima Y(u)macrko invites the reader to consider the embodied response to light of Takiko, a young pregnant woman. Emiko, the protagonist of Hishoku (Without Colour, 1967) by Ariyoshi Sawako, is the Japanese wife of an African American and has just given birth to a child. The daughter protagonist in Enchi Fumiko's 'Kami' ('Hair', 1957) operates a hairdressing business that is viable only with her mother's unpaid labour. The narratives are read through a matrix of post-structuralist theories of embodiment, drawing on the work of writers such as Julia Kristeva, Luce Irigaray and Elizabeth Grosz.

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X-ray reflectivity of bovine and sheep surfactant-associated protein B (SP-B) monolayers is used in conjunction with pressure-area isotherms and protein models to suggest that the protein undergoes changes in its tertiary structure at the air/water interface under the influence of surface pressure, indicating the likely importance of such changes to the phenomena of protein squeeze out as well as lipid exchange between the air-water interface and subphase structures. We describe an algorithm based on the well-established box- or layer-models that greatly assists the fitting of such unknown scattering-length density profiles, and which takes the available instrumental resolution into account. Scattering-length density profiles from neutron reflectivity of bovine SP-B monolayers on aqueous subphases are shown to be consistent with the exchange of a large number of labile protons as well as the inclusion of a significant amount of water, which is partly squeezed out of the protein monolayer at elevated surface pressures.

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Conventional methods to determine surface diffusion of adsorbed molecules are proven to be inadequate for strongly adsorbing vapors on activated carbon. Knudsen diffusion permeability (B-k) for strongly adsorbing vapors cannot be directly estimated from that of inert gases such as helium. In this paper three models are considered to elucidate the mechanism of surface diffusion in activated carbon. The transport mechanism in all three models is a combination of Knudsen diffusion, viscous flow and surface diffusion. The collision reflection factor f (which is the fraction of molecules undergoing collision to the solid surface over reflection from the surface) of the Knudsen diffusivity is assumed to be a function of loading. It was found to be 1.79 in the limit of zero loading, and decreases as loading increases. The surface diffusion permeability increases sharply at very low pressures and then starts to decrease after it has reached a maximum (B(mum)s) at a threshold pressure. The initial rapid increase in the total permeability is mainly attributed to surface diffusion. Interestingly the B(mum)s for all adsorbates appear at the same volumetric adsorbed phase concentration, suggesting that the volume of adsorbed molecules may play an important role in the surface diffusion mechanism in activated carbon. (C) 2003 Elsevier Ltd. All rights reserved.

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For the first time it was possible to observe regular quasiperiodic scintillations (QPS) in VHF radio-satellite transmissions from orbiting satellites simultaneously at short (2.1 km) and long (121 km) meridional baselines in the vicinity of a typical mid-latitude station (Brisbane; 27.5degreesS and 152.9degreesE geog. and 35.6degrees invar.lat.), using three sites (St. Lucia-S, Taringa-T in Brisbane and Boreen Pt.-B, north of Brisbane). A few pronounced quasiperiodic (QP) events were recorded showing unambiguous regular structures at the sites which made it possible to deduce a time displacement of the regular fading minimum at S, T and B. The QP structure is highly dependent on the geometry of the ray-path from a satellite to the observer which is manifested as a change of a QP event from symmetrical to non-symmetrical for stations separated by 2.1 km, and to a radical change in the structure of the event over a distance of 121 km. It is suggested the short-duration intense QP events are due to a Fresnel diffraction (or a reflection mechanism) of radio-satellite signals by a single ionospheric irregularity in a form of an ellipsoid with a large ionization gradient along the major axis. The structure of a QP event depends on the angle of viewing of the irregular blob from a radio-satellite. In view of this it is suggested that the reported variety of the ionization formation, responsible for different types of QPS, is only apparent but not real. (C) 2003 Elsevier Science Ltd. All rights reserved.

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Como reflexo de uma tend??ncia que tem ganhado import??ncia crescente nas organiza????es p??blicas, privadas e n??o governamentais do Brasil e do mundo, a tem??tica gest??o do conhecimento motivou a realiza????o desta pesquisa, cujo foco imediato ?? fornecer subs??dios para auxiliar organiza????es p??blicas como escolas de governo em seus processos de desenvolvimento de conhecimento organizacional. Este conhecimento ?? criado mediante a intera????o dos conhecimentos t??cito e expl??cito. A intera????o entre eles pode ser verificada por meio de quatro convers??es, as quais formam um ciclo do conhecimento organizacional: a socializa????o, a externaliza????o, a combina????o e a internaliza????o. O estudo em quest??o visa apresentar um conjunto de crit??rios representantes do ciclo de desenvolvimento do conhecimento organizacional e, mediante an??lise comparada entre sete escolas de governo internacionais e uma nacional, a Funda????o Escola Nacional de Administra????o P??blica (Enap), elaborar o desenho de uma estrutura organizacional que maximize o desenvolvimento do conhecimento organizacional em escolas de governo.

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Este artigo objetiva propor o debate sobre qual ser?? o papel das ouvidorias judiciais no processo de comunica????o social do Poder Judici??rio brasileiro. A inten????o ?? iniciar a discuss??o em busca de quais podem ser as contribui????es dessa importante ferramenta de participa????o popular e promo????o da cidadania para a melhoria da comunica????o p??blica realizada pelos tribunais. Essa reflex??o se faz necess??ria no atual cen??rio em que a sociedade brasileira vem, cada vez mais, exigindo maior transpar??ncia da administra????o p??blica, mormente ap??s a edi????o da Lei de Acesso ?? Informa????o.

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O trabalho pretende desenvolver uma reflex??o sobre a profissionaliza????o dos cargos de dire????o na administra????o p??blica e sua evolu????o ao longo das ??ltimas d??cadas nos pa??ses desenvolvidos, tendo como eixo condutor a institucionaliza????o dos cargos de dirigentes p??blicos nos sistemas pol??tico-administrativos contempor??neos. Inicia-se definindo a expans??o e o desenvolvimento do gerenciamento nos sistemas p??blicos, descrevendo, de forma breve e comparada, sua evolu????o mais recente em alguns pa??ses da OCDE. Em seguida, s??o apontados os tra??os b??sicos de um modelo de exerc??cio das fun????es de dire????o na administra????o p??blica. A seguir, trata-se do tema central mencionado. Primeiramente, o texto define os elementos que configuram um marco institucional para as fun????es de dire????o no setor p??blico. Depois, aborda o conte??do, o alcance e o ??mbito das reformas necess??rias para a constru????o desse marco. Por ??ltimo, analisa as vari??veis que podem influenciar a elabora????o das reformas, expondo os principais desafios e dificuldades tra??ados pelos empenhos de reforma.

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O artigo explora o est??gio de implementa????o do governo eletr??nico no Brasil, apoiando-se no ranking das Na????es Unidas para discutir o posicionamento do pa??s diante do contexto global de e-gov. ?? apresentado o conceito de governo eletr??nico, sendo abordados, em seguida, os programas do governo federal brasileiro relacionados com essa pol??tica. Conclui-se que o Brasil alcan??ou, at?? 2002, boas avalia????es em seu programa de e-gov como resultado, especialmente, da implementa????o de alguns ???casos de sucesso??? ??? como o Comprasnet e o imposto de renda pela Internet. A partir de 2003, entretanto, sua trajet??ria passou a ser descendente, cedendo lugar a outros pa??ses que se encontravam, anteriormente, em posi????es inferiores no ranking. Ao final do artigo ?? feita uma reflex??o sobre as perspectivas para o e-gov no pa??s, vislumbrando-se um futuro capaz de recolocar o Brasil em posi????o mais pr??xima a dos pa??ses que possuem programas de e-governo em est??gios mais avan??ados de desenvolvimento.

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Quais as funcionalidades necess??rias aos sistemas de compras eletr??nicas no ambiente da administra????o p??blica? Que par??metros s??o relevantes para a an??lise e a avalia????o desses sistemas? O trabalho aborda a aplica????o da tecnologia da informa????o ??s compras governamentais, focalizando o caso do Sistema Integrado de Administra????o de Servi??os Gerais (Siasg) e seu portal na Internet, o Comprasnet, desenvolvido pela Administra????o P??blica Federal brasileira. Contextualiza a emerg??ncia do com??rcio eletr??nico e sua aplica????o ?? administra????o p??blica. Sistematiza as fases e os procedimentos do processo de compras e contrata????es na administra????o p??blica brasileira, indicando os componentes e as funcionalidades que devem compor os sistemas de compras eletr??nicas governamentais. Prop??e par??metros de an??lise para a avalia????o desses sistemas: abrang??ncia, inser????o e impacto na transforma????o da gest??o. A aplica????o desses par??metros ao estudo de caso evidencia que o Siasg/Comprasnet apresenta abrang??ncia ainda incompleta, inser????o consolidada e impacto transformador mais acentuado sobre as compras realizadas por meio de modalidades de licita????o eletr??nicas.

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?? crescente o envolvimento de organiza????es p??blicas e privadas com alian??as e parcerias. No novo cen??rio colaborativo, uma nova abordagem para o planejamento das organiza????es precisa ser desenvolvida, com especial aten????o para o setor p??blico, em cujo ambiente a escassez de recursos pode ser total ou parcialmente suprida pela cria????o ou incremento de redes entre organiza????es e sistemas. A nova abordagem para a coordena????o interorganizacional no ??mbito do planejamento governamental pode resultar em algum tipo de ???organiza????o virtual??? para o setor p??blico, ?? semelhan??a do que j?? ocorre no setor privado. O artigo destaca a import??ncia da reflex??o sobre as implica????es e possibilidades que os conceitos relativos a organiza????es virtuais podem trazer para a coordena????o interorganizacional no ??mbito do planejamento governamental, de forma a contribuir para incrementar a efetividade da a????o de governo, por meio de ambiente informacional cooperativo. Aspectos como cultura organizacional, poder e controle, fronteiras e estruturas organizacionais, confian??a e gest??o cooperativa da informa????o dever??o ser observados no contexto do planejamento governamental, caso se pretenda evoluir na aplica????o do conceito de organiza????es virtuais no setor p??blico

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Nesta comunica????o, discutem-se as compet??ncias exigidas aos dirigentes pelos novos desafios de gest??o p??blica e prop??em-se as bases do que poder?? vir a constituir uma carta latino-iberoamericana sobre as compet??ncias que devem ser desenvolvidas e garantidas no grupo dirigente da Administra????o P??blica dos Estados representados no CLAD. Esta reflex??o baseia-se nos processos de diagn??stico e de forma????o que t??m vindo a ser promovidos pelo Instituto Nacional de Administra ????o no ??mbito da reforma da Administra????o P??blica em curso em Portugal.