2,701 research outputs found
Discriminating different scenarios to account for the cosmic excess by synchrotron and inverse Compton radiation
The excesses of the cosmic positron fraction recently measured by PAMELA and
the electron spectra by ATIC, PPB-BETS, Fermi and H.E.S.S. indicate the
existence of primary electron and positron sources. The possible explanations
include dark matter annihilation, decay, and astrophysical origin, like
pulsars. In this work we show that these three scenarios can all explain the
experimental results of the cosmic excess. However, it may be difficult
to discriminate these different scenarios by the local measurements of
electrons and positrons. We propose possible discriminations among these
scenarios through the synchrotron and inverse Compton radiation of the primary
electrons/positrons from the region close to the Galactic center. Taking
typical configurations, we find the three scenarios predict quite different
spectra and skymaps of the synchrotron and inverse Compton radiation, though
there are relatively large uncertainties. The most prominent differences come
from the energy band MHz for synchrotron emission and GeV for inverse Compton emission. It might be able to discriminate at least
the annihilating dark matter scenario from the other two given the high
precision synchrotron and diffuse -ray skymaps in the future.Comment: published in Pr
The effects of different tensile parameters for the neurodynamic mobilization technique on tricipital muscle wet weight and MuRf-1 expression in rabbits with sciatic nerve injury
BACKGROUND: After peripheral nerve injury, muscles without innervation begin to undergo atrophy. Research has suggested that MuRf-1 may play a role in muscle atrophy. The neurodynamic mobilization technique (NMT) is a manual therapy method used to elongate a nerve along its long axis, resulting in improved blood flow to the nerve. However, the nerve can be damaged if elongated too much. The purpose of this study is to observe the effect of NMT on muscle wet weight and MuRf-1 expression in rabbits with sciatic nerve injury. METHODS: Six adult rabbits were measured to determine the relationship between the joint angle of the lower limb and percent of sciatic nerve elongation to define the tensile parameters of NMT; Thirty adult rabbits were randomly assigned into a sham, model, NMT-A, NMT-B, or NMT-C groups. Four weeks post-treatment, the wet mass of the tricipital muscles and MuRf-1 expression were observed. RESULTS: The wet mass of the tricipital muscles in the NMT-B group was significantly greater than the NMT-A, NMT-C, and model groups. In addition, MuRf-1 expression was significantly reduced in the NMT-B group compared with the NMT-A, NMT-C, and model groups. CONCLUSIONS: Elongating the nerve by NMT of 9% in rabbits decreased MuRf-1 expression and decelerated muscle atrophy in the subjects with sciatic nerve injury
2,6-Dichloro-N-(4-chlorophenyl)benzamide
In the title compound, C13H8Cl3NO, the dihedral angle between the benzene rings is 63.2 (2)°. In the crystal, N—H⋯O hydrogen bonds link the molecules into C(4) chains propagating in [001]. Weak aromatic π–π stacking also occurs [centroid–centroid separations = 3.759 (3) and 3.776 (3) Å]
Electromagnetic Performance Comparison between 12-Phase Switched Flux and Surface-Mounted PM Machines for Direct-Drive Wind Power Generation
In this article, the 12-phase switched flux permanent magnet (PM) (SFPM) machine and three surface-mounted PM (SPM) machines designed for direct-drive wind power generation are comparatively analyzed. First, feasible stator-slot/rotor-pole combinations for symmetrical 12-phase winding layout are investigated for both machine topologies. Second, the key design parameters of the PM generators including the split ratio and stator teeth width ratio are optimized by finite element analysis to achieve a high phase fundamental EMF per turn and a low cogging torque, both of which are desired by the direct-drive wind power generator. Third, electromagnetic performances including air-gap field, cogging torque, static torque, inductance, output voltage and its regulation factor, output power, and efficiency of the generators are compared. A 10-kW 24-slot/22-pole SFPM prototype is built and tested to validate the FE predicted results.</p
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