40,450 research outputs found
Atomistic origins of the phase transition mechanism in Ge2Sb2Te5
Combined static and molecular dynamics first-principles calculations are used
to identify a direct structural link between the metastable crystalline and
amorphous phases of Ge2Sb2Te5. We find that the phase transition is driven by
the displacement of Ge atoms along the rocksalt [111] direction from the
stable-octahedron to high-energy-unstable tetrahedron sites close to the
intrinsic vacancy regions, which give rise to the formation of local 4-fold
coordinated motifs. Our analyses suggest that the high figures of merit of
Ge2Sb2Te5 are achieved from the optimal combination of intrinsic vacancies
provided by Sb2Te3 and the instability of the tetrahedron sites provided by
GeTe
Sustainability reporting: the case of Meliá
Students seldom contemplate the importance of sustainability in family businesses. Indeed,
the economic dimension of sustainability using performance statements remains a neglected
field of study. The case of a Spain family firm in the tourism sector, Meliá Hotels
International, is used to introduce students to sustainability analyses through the study of
the company's sustainability information. This provides instructors with an opportunity to
discuss the actual financial state of the company and how to improve some indicators, as
well as to present an overview of the long term sustainability of a family business.
A qualitative methodology is used based on the documental analysis of sustainability
reporting and information collected from the company's website and the media.
This case can be used in management and accounting classes at both the bachelor and
master levels. It is an important topic for users of financial information, entrepreneurs and
other stakeholders concerned with these issues.info:eu-repo/semantics/publishedVersio
Análise físico-química e sensorial de biscoitos elaborados com resíduo de caju e de maracujá.
Formas de nitrogênio e tipo de substrato nos parâmetros de absorção de fósforo pelo milho-doce.
Foram realizados dois experimentos em casa de vegetação, em solo e em solução nutritiva, para testar, em milho-doce, o modelo matemático de Cushmao-Barber, utilizado para predizer a absorção de fósforo. Foram efetuadas análises de sensibilidade, para estudar o efeito, na absorção, da mudança de cada um dos parâmetros. A área superficial de raízes teve grande efeito na absorção de fósforo, em ambos os substratos. independente da fonte de nitrogênio. Verificou-se uma interação substrato x fonte de nitrogênio, embora a amplitude de absorção de fósforo fosse a mesma em todos os casos. Os resultados obtidos mostram que o suprimento de fósforo pelo substrato não foi o passo limitante na absorção desse nutriente pelas plantas
Non(anti)commutative superspace with coordinate-dependent deformation
We consider non(anti)commutative superspace with coordinate dependent
deformation parameters . We show that a chiral
supersymmetry can be defined and that chiral and antichiral superfields are
still closed under the Moyal-Weyl associative product implementing the
deformation. A consistent Super Yang-Mills deformed theory can
be constructed provided satisfies a suitable condition which
can be connected with the graviphoton background at the origin of the
deformation. After adding matter we also discuss the Konishi anomaly and the
gluino condensation.Comment: References added. Accepted for publication in PR
Fauna invertebrada epigéica em solo cultivado com adubos verdes em Mato Grosso do Sul.
FERTBIO 2010
Continuous spectra in high-harmonic generation driven by multicycle laser pulses
We present observations of the emission of XUV continua in the 20-37 eV
region by high harmonic generation (HHG) with - pulses
focused onto a Kr gas jet. The underlying mechanism relies on coherent control
of the relative delays and phases between individually generated attosecond
pulse, achievable by adjusting the chirp of the driving pulses and the
interaction geometry. Under adequate negative chirp and phase matching
conditions, the resulting interpulse interference yields a continuum XUV
spectrum, which is due to both microscopic and macroscopic (propagation)
contributions. This technique opens the route for modifying the phase of
individual attosecond pulses and for the coherent synthesis of XUV continua
from multicycle driving laser pulses without the need of an isolated attosecond
burst.Comment: 14 pages, 5 figures. Submitted to Physical Review
Autoria na Web 2.0 no contexto da educação e a ética dos hackers.
Este artigo discute a importância do exercício da autoria em ambiente virtual da Web 2.0, considerando que se trata de fundamento essencial à aprendizagem, no professor e no aluno. Autoria na Web 2.0 é apresentada como estratégia pedagógica para ambientes de aprendizagem virtuais, que se utilizam principalmente de ferramentas como blog, wiki e redes sociais. Embora não sejam determinantes essas, tecnologias digitais são condicionantes para que a aprendizagem e a autoria ocorram. Autoria na Web 2.0, além do estabelecimento de novos aparatos tecnológicos, requer novos modos de produção, nos quais prevaleça a postura ética dos hackers, favorecendo a participação, a colaboração, a liberdade e o compartilhamento.Artigo publicado na revista ETD - Educação Temática Digital, Campinas, SP, v. 12, n. esp., p. 154-173, mar. 2011
Potência, perfil sensorial e aceitação de um sal hipossódico formulado com cloreto de potássio.
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