1,039 research outputs found
Intersecting non-SUSY -brane with chargeless 0-brane as black -brane
Unlike BPS -brane, non-supersymmetric (non-susy) -brane could be either
charged or chargeless. As envisaged in [hep-th/0503007], we construct an
intersecting non-susy -brane with chargeless non-susy -brane by taking
T-dualities along the delocalized directions of the non-susy -brane solution
delocalized in transverse directions (where ). In general
these solutions are characterized by four independent parameters. We show that
when the intersecting charged as well as chargeless non-susy -brane
with chargeless 0-brane can be mapped by a coordinate transformation to black
-brane when two of the four parameters characterizing the solution take some
special values. For definiteness we restrict our discussion to space-time
dimensions . We observe that parameters characterizing the black brane
and the related dynamics are in general in a different branch of the parameter
space from those describing the brane-antibrane annihilation process. We
demonstrate this in the two examples, namely, the non-susy D0-brane and the
intersecting non-susy D4 and D0-branes, where the solutions with the explicit
microscopic descriptions are known.Comment: 25 page
Probing the Turbulence Dissipation Range and Magnetic Field Strengths in Molecular Clouds
We study the turbulent velocity dispersion spectra of the coexistent HCN and
HCO+ molecular species as a function of length scale in the M17 star-forming
molecular cloud. We show that the observed downward shift of the ion's spectrum
relative to that of the neutral is readily explained by the existence of an
ambipolar diffusion range within which ion and neutral turbulent energies
dissipate differently. We use these observations to evaluate this decoupling
scale and show how to estimate the strength of the plane-of-the-sky component
of the embedded magnetic field in a completely novel way.Comment: 15 pages, 3 figures, accepted for publication in The Astrophysical
Journa
Comparison of 3-, 5-, and 6-Phase Machines for Automotive Charging Applications
In this paper, the performance of a 5-phase claw-pole machine/converter system is compared with those of 3-phase and 6-phase systems of the same volume. It is shown that the acoustic output of the 5-phase machine compares favorably with that of the 6-phase machine and is much lower than that of the 3-phase machine over a majority of the operating range. In addition, the output current produced by the 5-phase machine Is, in general, 6-8% higher than those of the 3-phase and 6-phase machines. These results suggest that for maximizing power density while minimizing cost and acoustic noise, 5-phase machines provide a competitive alternative to 6-phase machines of identical volume
Local Magnetic Field Role in Star Formation
We highlight distinct and systematic observational features of magnetic field
morphologies in polarized submm dust continuum. We illustrate this with
specific examples and show statistical trends from a sample of 50 star-forming
regions.Comment: 4 pages, 3 figures; to appear in the EAS Proceedings of the 6th
Zermatt ISM Symposium "Conditions and Impact of Star Formation from Lab to
Space", September 201
The alignment of molecular cloud magnetic fields with the spiral arms in M33
The formation of molecular clouds, which serve as stellar nurseries in
galaxies, is poorly understood. A class of cloud formation models suggests that
a large-scale galactic magnetic field is irrelevant at the scale of individual
clouds, because the turbulence and rotation of a cloud may randomize the
orientation of its magnetic field. Alternatively, galactic fields could be
strong enough to impose their direction upon individual clouds, thereby
regulating cloud accumulation and fragmentation, and affecting the rate and
efficiency of star formation. Our location in the disk of the Galaxy makes an
assessment of the situation difficult. Here we report observations of the
magnetic field orientation of six giant molecular cloud complexes in the
nearby, almost face-on, galaxy M33. The fields are aligned with the spiral
arms, suggesting that the large-scale field in M33 anchors the clouds.Comment: to appear in Natur
Quantum Theory Approach for Neutron Single and Double-Slit Diffraction
We provide a quantum approach description of neutron single and double-slit
diffraction, with specific attention to the cold neutron diffraction (\AA) carried out by Zeilinger et al. in 1988. We find the
theoretical results are good agreement with experimental data.Comment: 10 page
Two band gap field-dependent thermal conductivity of
The thermal conductivity of the new superconductor was
studied as a function of the temperature and a magnetic field. No anomaly in
the thermal conductivity is observed around the superconducting
transition in absence or presence of magnetic fields up to 14 Tesla; upon that
field the superconductivity of persisted. The thermal conductivity in
zero-field shows a -linear increase up to 50K. The thermal conductivity is
found to increase with increasing field at high fields. We interpret the
findings as if there are two subsystems of quasiparticles with different
field-dependent characters in a two ( and )-band superconductor reacting
differently with the vortex structure. The unusual enhancement of at low temperature but higher than a () critical field
is interpreted as a result of the overlap of the low energy states outside the
vortex cores in the -band.Comment: 6 pages,3 figure
Ca2+ Cycling in Heart Cells from Ground Squirrels: Adaptive Strategies for Intracellular Ca2+ Homeostasis
Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca2+ homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca2+ current (ICa) was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of ICa did not compromise the Ca2+-induced Ca2+ release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of ICa. Both the caffeine-sensitive and caffeine-resistant components of cytosolic Ca2+ removal were more rapid in ground squirrels. Ca2+ sparks in ground squirrels exhibited larger amplitude/size and much lower frequency than in rats. Due to the high ICa threshold, low SR Ca2+ leak and rapid cytosolic Ca2+ clearance, heart cells from ground squirrels exhibited better capability in maintaining intracellular Ca2+ homeostasis than those from rats and other nonhibernating mammals. These findings not only reveal adaptive mechanisms of hibernation, but also provide novel strategies against Ca2+ overload-related heart diseases
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