2,394 research outputs found
Nanometric pitch in modulated structures of twist-bend nematic liquid crystals
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 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
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
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
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.
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.
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
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A 3D printed drug delivery implant formed from a dynamic supramolecular polyurethane formulation
Using a novel molecular design approach, we have prepared a thermo-responsive supramolecular polyurethane as a matrix material for use in drug eluting implants. The dynamic supramolecular polyurethane (SPU) is able to self-assemble through hydrogen bonding and π-π stacking interactions, resulting in an addressable polymer network with a relatively low processing temperature. The mechanical properties of the SPU demonstrated the material was self-supporting, stiff, yet flexible thus making it suitable for hot-melt extrusion processing, inclusive of related 3D printing approaches. Cell-based toxicity assays revealed the SPU to be non-toxic and therefore a viable candidate as a biocompatible polymer for implant applications. To this end, the SPU was formulated with paracetamol (16 %w/w) and 4 wt% or 8 wt% poly(ethylene glycol) (PEG) as an excipient and hot melt extruded at 100 °C to afford a 3D printed prototype implant to explore the extended drug release required for an implant and the potential manipulation of the release profile. Furthermore, rheological, infra-red spectroscopy, powder X-ray diffraction and scanning electron microscopy studies revealed the chemical and physical properties and compatibility of the formulation components. Successful release of paracetamol was achieved from in vitro dissolution studies and it was predicted that the drug would be released over a period of up to 8.5 months with hydrophilic PEG being able to influence the release rate. This extended release time is consistent with applications of this novel dynamic polymer as a drug eluting implant matrix
GAME: Grb and All-sky Monitor Experiment
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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