18,185 research outputs found
Group theory for structural analysis and lattice vibrations in phosphorene systems
Group theory analysis for two-dimensional elemental systems related to
phosphorene is presented, including (i) graphene, silicene, germanene and
stanene, (ii) dependence on the number of layers and (iii) two stacking
arrangements. Departing from the most symmetric graphene space
group, the structures are found to have a group-subgroup relation, and analysis
of the irreducible representations of their lattice vibrations makes it
possible to distinguish between the different allotropes. The analysis can be
used to study the effect of strain, to understand structural phase transitions,
to characterize the number of layers, crystallographic orientation and
nonlinear phenomena.Comment: 24 pages, 3 figure
The Mass-to-Light Ratio of Binary Galaxies
We report on the mass-to-light ratio determination based on a newly selected
binary galaxy sample, which includes a large number of pairs whose separations
exceed a few hundred kpc. The probability distributions of the projected
separation and the velocity difference have been calculated considering the
contamination of optical pairs, and the mass-to-light ratio has been determined
based on the maximum likelihood method. The best estimate of in the B
band for 57 pairs is found to be 28 36 depending on the orbital
parameters and the distribution of optical pairs (solar unit, km
s Mpc). The best estimate of for 30 pure spiral pairs is
found to be 12 16. These results are relatively smaller than those
obtained in previous studies, but consistent with each other within the errors.
Although the number of pairs with large separation is significantly increased
compared to previous samples, does not show any tendency of increase, but
found to be almost independent of the separation of pairs beyond 100 kpc. The
constancy of beyond 100 kpc may indicate that the typical halo size of
spiral galaxies is less than kpc.Comment: 18 pages + 8 figures, to appear in ApJ Vol. 516 (May 10
Architectural design digital change: interactivity policy
Several researches have been focused on digital architecture historical perspectives of the design throughout the sixties. This paper purposes a different view based on the influence of art, science and computation in architecture that contributed to the use of interactivity in architectural design. The aim is to describe the evolution of interactive CAD from MIT’s Project CAD and Ivan Sutherland’s Sketchpad to the early digital architectural design pioneers: Steven Coons, Gyorgy Kepes and Nicholas Negroponte.info:eu-repo/semantics/publishedVersio
On the quantumness of correlations in nuclear magnetic resonance
Nuclear Magnetic Resonance (NMR) was successfully employed to test several
protocols and ideas in Quantum Information Science. In most of these
implementations the existence of entanglement was ruled out. This fact
introduced concerns and questions about the quantum nature of such bench tests.
In this article we address some issues related to the non-classical aspects of
NMR systems. We discuss some experiments where the quantum aspects of this
system are supported by quantum correlations of separable states. Such
quantumness, beyond the entanglement-separability paradigm, is revealed via a
departure between the quantum and the classical versions of information theory.
In this scenario, the concept of quantum discord seems to play an important
role. We also present an experimental implementation of an analogous of the
single-photon Mach-Zehnder interferometer employing two nuclear spins to encode
the interferometric paths. This experiment illustrate how non-classical
correlations of separable states may be used to simulate quantum dynamics. The
results obtained are completely equivalent to the optical scenario, where
entanglement (between two field modes) may be present
Efeito da água residuária do café em plantas de milho.
O processamento do café por via úmida gera água residuária (ARC), contendo material orgânico, com potencial de poluir o meio aquático. Este trabalho teve como objetivo estudar o efeito da aplicação da ARC sobre o crescimento e teores de minerais em plantas de milho, na fase vegetativa. Foram estudados oito tratamentos: 0, 50, 100, 150, 200, 250, 300 e 350 mL de ARC por planta, aplicada sobre as folhas, em 3 ocasiões. A aplicação da ARC não provocou injúrias visÃveis nas plantas de milho e nem alterou o peso da matéria seca das plantas. O teor de K aumentou e o teor de Mg diminuiu linearmente com o aumento das doses de ARC aplicadas, enquanto os teores de Ca e Na nas folhas de milho não foram afetados
- …