2,370 research outputs found

    Nanometric pitch in modulated structures of twist-bend nematic liquid crystals

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    The extended Frank elastic energy density is used to investigate the existence of a stable periodically modulate structure that appears as a ground state exhibiting a twist-bend molecular arrangement. For an unbounded sample, we show that the twist-bend nematic phase NTBN_{TB} is characterized by a heliconical structure with a pitch in the nano-metric range, in agreement with experimental results. For a sample of finite thickness, we show that the wave vector of the stable periodic structure depends not only on the elastic parameters but also on the anchoring energy, easy axis direction, and the thickness of the sample.Comment: 11 page

    The Contribution of the Smectic-Nematic Interface to the Surface Energy

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    The contribution of the smectic-nematic interface to the surface energy of a nematic liquid crystal sample is analyzed. By means of a simple model it is shown that the surface energy depends on the thickness of the region over which the transition smectic-nematic takes place. For perfectly flat substrates this thickness is of the order of the correlation length entering in the transition. An estimate of this contribution shows that it is greater than the one arising from the nematic-substrate interaction. Moreover, it is also shown that the surface energy determined in this way presents a non-monotonic behavior with the temperature.Comment: 10 pages, revte

    The 3D numerical simulation of near-source ground motion during the Marsica earthquake, central Italy, 100 years later

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    In this paper we show 3D physics-based numerical simulations of ground motion during one of the most devastating earthquakes in the recent Italian history, occurred on Jan 13, 1915, Marsica, Central Italy. The results provide a realistic estimate of the earthquake ground motion and fit reasonably well both the geodetic measurements of permanent ground settlement, and the observed macroseismic distribution of damage. In addition, these results provide a very useful benchmark to improve the current knowledge of near-source earthquake ground motion, including evaluation of the best distance metrics to describe the spatial variability of the peak values of ground motion, the relative importance of fault normal vs fault parallel components, the conditions under which vertical ground motion may prevail, as well as the adequacy of 1D vs 3D modelling of site amplification effects

    Elementos da comunicação visual de marca de lugares : análise da composição da marca do Peru

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    Em um cenário cada vez mais competitivo, as marcas auxiliam no processo de identificação e diferenciação de um produto, serviço, território ou lugar, tornando-se cada vez mais importante na conquista do seu reconhecimento diante de seu público. Assim como empresas procuram se destacar diante a concorrência, os países competem para buscar a atenção de turistas e investidores. O Peru, percebendo a necessidade em atrair e impulsionar as exportações, investimentos e turismo, reformulou sua identidade visual e apresentou-a em 2011. O presente estudo foi realizado a partir de uma revisão bibliográfica e de um estudo de caso da marca turística do Peru, que teve como objetivo analisar a utilização dos elementos da comunicação visual verificando se sua aplicação transmite ao público a expectativa desejada pelo país.ABSTRACT: In an increasingly competive environment, brands assist in the identification and differentiation of a product, service, territory or place process, becoming increasingly important in the achievement of their recognition in front of your audience. As companies seek to stand before the competition, countries compete to get the attention of tourists and investors. Peru, realizing the need to attract and boost exports, investments and tourism, redesigned its visual identity and presented it in 2011. This study was conducted from a literature review and a case study of Peru's tourism brand, which aims to analyze the use of elements of visual communication checking if your application passes the expectation required by the country to the public.info:eu-repo/semantics/publishedVersio

    Personalização dos softwares HiperEditor e HiperNavegador para uso na Agência de Informação Embrapa.

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    Este trabalho descreve o desenvolvimento de uma versão personalizada dos softwares HiperEditor e HiperNavegador para uso no Gestor de Conteúdo da Agência de Informação Embrapa, visando atender aos novos requisitos dos usuários nesse sistema. As atualizações foram concebidas por meio do uso dos códigos-fonte dos softwares, da biblioteca JDK, do ambiente de desenvolvimento Eclipse e do sistema operacional Kubuntu. A nova versão do HiperEditor traz uma interface gráfica mais amigável e intuitiva, além de novas funcionalidades: alterar cor do texto ou de preenchimento do nó, ordenação semântica, inserir imagem de ícone ou miniatura ao nó e imprimir estrutura hierárquica. O HiperNavegador personalizado permite que as alterações realizadas em uma determinada estrutura hierárquica por meio do HiperEditor possam ser visualizadas.bitstream/item/11846/1/doc83.pd

    Diretrizes para escolha de um Sistema de Gerenciamento de Conteúdos.

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    O objetivo deste documento é apresentar as diretrizes básicas para escolha de um CMS tomando por base a experiência adquirida com o desenvolvimento do Agritempo.bitstream/CNPTIA/10192/1/comtec53.pdfAcesso em: 28 maio 2008

    GAME: Grb and All-sky Monitor Experiment

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    We describe the GRB and All-sky Monitor Experiment (GAME) mission submitted by a large international collaboration (Italy, Germany, Czech Repubblic, Slovenia, Brazil) in response to the 2012 ESA call for a small mission opportunity for a launch in 2017 and presently under further investigation for subsequent opportunities. The general scientific objective is to perform measurements of key importance for GRB science and to provide the wide astrophysical community of an advanced X-ray all-sky monitoring system. The proposed payload was based on silicon drift detectors (~1-50 keV), CdZnTe (CZT) detectors (~15-200 keV) and crystal scintillators in phoswich (NaI/CsI) configuration (~20 keV-20 MeV), three well established technologies, for a total weight of ~250 kg and a required power of ~240 W. Such instrumentation allows a unique, unprecedented and very powerful combination of large field of view (3-4 sr), a broad energy energy band extending from ~1 keV up to ~20 MeV, an energy resolution as good as ~300 eV in the 1-30 keV energy range, a source location accuracy of ~1 arcmin. The mission profile included a launch (e.g., by Vega) into a low Earth orbit, a baseline sky scanning mode plus pointed observations of regions of particular interest, data transmission to ground via X-band (4.8 Gb/orbit, Alcantara and Malindi ground stations), and prompt transmission of GRB / transient triggers.Comment: 13 pages, 8 figures, published in International Journal of Modern Physics
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