2,625 research outputs found
Viscoelastic evaluation of biological soft tissue in crush process at subsonic level for anti-bird strike technology of airplane
Miniaturization and lightening of airplane are advanced to improve its economic efficiency, and the safety technology of airplane design becomes difficult while the accident of bird-strike is increasing year by year. Then a system of shock impact test by using airsoft rifle is developed to evaluate the design technology of anti-bird strike structure of airplane. The viscoelastic characteristics of specimen is evaluated by analyzing stress response using the modified Hertz contact theory and the wave equation at the moment when simple ball bullet is shot to specimen by the airsoft rifle. In the results of experiment, the obvious relationship is observed subjectively between quasi-static and impact responses of specimen. The evaluated viscoelastic relationship is applied to simulate the impact test by using LSDYNA with fundamental viscoelastic constitutive equation and the material parameters derived from the impact test, and the well similar behavior has been simulated by the constitutive equation. By using the developed technology here, the phantom imitating real bird will be developed as standard specimen for an anti-bird strike test in future
Abelian Higgs Hair for AdS-Schwarzschild Black Hole
We show that the Abelian Higgs field equations in the background of the four
dimensional AdS-Schwarzschild black hole have a vortex line solution. This
solution, which has axial symmetry, is a generalization of the AdS spacetime
Nielsen-Olesen string. By a numerical study of the field equations, we show
that black hole could support the Abelian Higgs field as its Abelian hair.
Also, we conside the self gravity of the Abelian Higgs field both in the pure
AdS spacetime and AdS-Schwarzschild black hole background and show that the
effect of string as a black hole hair is to induce a deficit angle in the
AdS-Schwarzschild black hole.Comment: 19 pages, 33 figure
Abelian Higgs Hair for a Static Charged Black String
We study the problem of vortex solutions in the background of an electrically
charged black string. We show numerically that the Abelian Higgs field
equations in the background of a four-dimensional black string have vortex
solutions. These solutions which have axial symmetry, show that the black
string can support the Abelian Higgs field as hair. This situation holds also
in the case of the extremal black string. We also consider the self-gravity of
the Abelian Higgs field and show that the effect of the vortex is to induce a
deficit angle in the metric under consideration.Comment: REVTEX4, 12 pages, 6 figures, The version to be appeared in Phys.
Rev.
Is CSR a magic word?: An exploring study of consumer behaviour in cosmetic market in Thailand
Many authors stated that decision-making today is more complex than in the past, especially when they are being confronted by various kinds of product (eg.: Hafstrom et al., 1992; Lysonski et al., 1995; Mitchell et al., 1998). Thailand is an example of a developing country where a huge number of products from various countries imported cosmetic products. Due to the competition in Thailand, cosmetic market is always very intense; therefore it is important for firms to understand the factors that affect the consumers purchasing behaviour. At the same time, Corporate Social Responsibility (CSR) has been one of the most popular theme for academics and marketers when they analyse its impact on consumersâ behaviour (Maignan and Ferrel, 2004; Smith, 2003). Does CSR have a positive impact on Thai consumersâ purchasing intention? To investigate this theme based on quantitative approach, we analyse the impact of CSR factor as an antecedent factor for Thai consumersâ attitudes towards cosmetic products, drawing the pathways resulting in their final decision of purchasing
Thermal-Fluid Flow Transport Phenomenon over Slot-Perforated Flat Plates Placed in Narrow Channel
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76151/1/AIAA-25872-119.pd
Modeling the gamma-ray emission produced by runaway cosmic rays in the environment of RX J1713.7-3946
Diffusive shock acceleration in supernova remnants is the most widely invoked
paradigm to explain the Galactic cosmic ray spectrum. Cosmic rays escaping
supernova remnants diffuse in the interstellar medium and collide with the
ambient atomic and molecular gas. From such collisions gamma-rays are created,
which can possibly provide the first evidence of a parent population of runaway
cosmic rays. We present model predictions for the GeV to TeV gamma-ray emission
produced by the collisions of runaway cosmic rays with the gas in the
environment surrounding the shell-type supernova remnant RX J1713.7-3946. The
spectral and spatial distributions of the emission, which depend upon the
source age, the source injection history, the diffusion regime and the
distribution of the ambient gas, as mapped by the LAB and NANTEN surveys, are
studied in detail. In particular, we find for the region surrounding RX
J1713-3946, that depending on the energy one is observing at, one may observe
startlingly different spectra or may not detect any enhanced emission with
respect to the diffuse emission contributed by background cosmic rays. This
result has important implications for current and future gamma-ray experiments.Comment: version published on PAS
Molecular Clouds as Cosmic-Ray Barometers
The advent of high sensitivity, high resolution gamma-ray detectors, together
with a knowledge of the distribution of the atomic hydrogen and especially of
the molecular hydrogen in the Galaxy on sub-degree scales creates a unique
opportunity to explore the flux of cosmic rays in the Galaxy. We here present
the new data on the distribution of the molecular hydrogen from a large region
of the inner Galaxy obtained by the NANTEN Collaboration. We then introduce a
methodology which aims to provide a test bed for current and future gamma-ray
observatories to explore the cosmic ray flux at various positions in our
Galaxy. In particular, for a distribution of molecular clouds, as provided by
the NANTEN survey, and local cosmic ray density as measured at the Earth, we
estimate the expected GeV to TeV gamma-ray signal, which can then be compared
with observations and use to test the cosmic ray flux.Comment: PASJ (in press
Perturbations of global monopoles as a black hole's hair
We study the stability of a spherically symmetric black hole with a global
monopole hair. Asymptotically the spacetime is flat but has a deficit solid
angle which depends on the vacuum expectation value of the scalar field. When
the vacuum expectation value is larger than a certain critical value, this
spacetime has a cosmological event horizon. We investigate the stability of
these solutions against the spherical and polar perturbations and confirm that
the global monopole hair is stable in both cases. Although we consider some
particular modes in the polar case, our analysis suggests the conservation of
the "topological charge" in the presence of the event horizons and violation of
black hole no-hair conjecture in asymptotically non-flat spacetime.Comment: 11 pages, 2 figures, some descriptions were improve
Probing the Galactic cosmic ray flux with submillimeter and gamma ray data
The study of Galactic diffuse radiation combined with the knowledge
of the distribution of the molecular hydrogen in the Galaxy offers a unique
tool to probe the cosmic ray flux in the Galaxy. A methodology to study the
level of the cosmic ray "sea" and to unveil target-accelerator systems in the
Galaxy, which makes use of the data from the high resolution survey of the
Galactic molecular clouds performed with the NANTEN telescope and of the data
from gamma-ray instruments, has been developed. Some predictions concerning the
level of the cosmic ray "sea" and the -ray emission close to cosmic ray
sources for instruments such as Fermi and Cherenkov Telescope Array are
presented.Comment: Proceedings of the 4th Heidelberg International Symposium on High
Energy Gamma-Ray Astronom
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