244 research outputs found
Influence of various gas inclusion in Ar thermal ICP at atmospheric pressure upon plasma temperature and impedance
The influence of various gas inclusions upon thermal plasma was investigated from the viewpoint of finding alternatives to SF6 as an arc-quenchingmdium in a high voltage circuit breaker. The onductively coupled thermal plasma (ICTP) technique was used to sustain thermal plasma. The effect of SF6 and six enviromental-benign gas inclusions on plasma temperature and impedance was measured. The result indicted that SF6 causes the plasma radius reduction and plasma temperature decline only with a several percentage inclusion. The similar tendency was found for CO2,while it was not found for the other five gases. This indicates that CO2 has a higher plasma-quenching property than the others in the experoment
Diagnosis of large volume pulse modulated Ar-H2 plasmas
金沢大学工学部Atmospheric pressure plasma in pre-mixed Ar/H2 flow was generated by pulse-modulation method. The coil length of the inductively-coupled plasma (ICP) torch was extremely large. The source side power was 30 kW before pulsation, and thus the plasma power had around 25.6 kW considering 85% matching efficiency
Controlling the number of excited atoms flowing into the reaction chamber using pulse-modulated induction thermal plasmas at atmospheric pressure
Controlling the number of excited atoms into a reaction chamber was investigated in Ar pulse-modulated induction thermal plasma (PMITP) with molecular gases at atmospheric pressure. Such control is important in promoting the modification of substrate surfaces in thermal plasma processing. The coil current required for sustaining a PMITP was modulated by setting the firing angle of the metal-oxide-semiconductor field-effect transistor in the inverter power supply used as a high-frequency power source. The radiation intensities of the excited atomic lines were measured using the optical emission spectroscopy technique to estimate the number of excited atoms flowing into the reaction chamber. In particular, we found an increase in the number of excited Ar and H atoms flowing into the reaction chamber in Ar or Ar-H2 PMITPs as a result of the pulse modulation of the coil current. © 2007 IOP Publishing Ltd
Excitations in the Halo Nucleus He-6 Following The Li-7(gamma,p)He-6 Reaction
A broad excited state was observed in 6-He with energy E_x = 5 +/- 1 MeV and
width Gamma = 3 +/- 1 MeV, following the reaction Li-7(gamma,p)He-6. The state
is consistent with a number of broad resonances predicted by recent cluster
model calculations. The well-established reaction mechanism, combined with a
simple and transparent analysis procedure confers considerable validity to this
observation.Comment: 3 pages of LaTeX, 3 figures in PostScript, approved for publication
in Phys. Rev. C, August, 200
Generation of high-power arbitrary-wave-form modulated inductively coupled plasmas for materials processing
Three-body resonances in He-6, Li-6, and Be-6, and the soft dipole mode problem of neutron halo nuclei
Using the complex scaling method, the low-lying three-body resonances of
He, Li, and Be are investigated in a parameter-free microscopic
three-cluster model. In He a 2, in Li a 2 and a 1, and in
Be the 0 ground state and a 2 excited state is found. The other
experimentally known 2 state of Li cannot be localized by our present
method. We have found no indication for the existence of the predicted 1
soft dipole state in He. We argue that the sequential decay mode of He
through the resonant states of its two-body subsystem can lead to peaks in the
excitation function. This process can explain the experimental results in the
case of Li, too. We propose an experimental analysis, which can decide
between the soft dipole mode and the sequential decay mode.Comment: REVTEX, Submitted to Phys. Rev. C, 12 pages, 2 postscript figures are
available upon request. CALTECH, MAP-16
Enhancement of Cardiac Store Operated Calcium Entry (SOCE) within Novel Intercalated Disk Microdomains in Arrhythmic Disease
Store-operated Ca2+ entry (SOCE), a major Ca2+ signaling mechanism in non-myocyte cells, has recently emerged as a component of Ca2+ signaling in cardiac myocytes. Though it has been reported to play a role in cardiac arrhythmias and to be upregulated in cardiac disease, little is known about the fundamental properties of cardiac SOCE, its structural underpinnings or effector targets. An even greater question is how SOCE interacts with canonical excitation-contraction coupling (ECC). We undertook a multiscale structural and functional investigation of SOCE in cardiac myocytes from healthy mice (wild type; WT) and from a genetic murine model of arrhythmic disease (catecholaminergic ventricular tachycardia; CPVT). Here we provide the first demonstration of local, transient Ca2+ entry (LoCE) events, which comprise cardiac SOCE. Although infrequent in WT myocytes, LoCEs occurred with greater frequency and amplitude in CPVT myocytes. CPVT myocytes also evidenced characteristic arrhythmogenic spontaneous Ca2+ waves under cholinergic stress, which were effectively prevented by SOCE inhibition. In a surprising finding, we report that both LoCEs and their underlying protein machinery are concentrated at the intercalated disk (ID). Therefore, localization of cardiac SOCE in the ID compartment has important implications for SOCE-mediated signaling, arrhythmogenesis and intercellular mechanical and electrical coupling in health and disease
Halo Excitation of He in Inelastic and Charge-Exchange Reactions
Four-body distorted wave theory appropriate for nucleon-nucleus reactions
leading to 3-body continuum excitations of two-neutron Borromean halo nuclei is
developed. The peculiarities of the halo bound state and 3-body continuum are
fully taken into account by using the method of hyperspherical harmonics. The
procedure is applied for A=6 test-bench nuclei; thus we report detailed studies
of inclusive cross sections for inelastic He(p,p')He and
charge-exchange Li(n,p)He reactions at nucleon energy 50 MeV. The
theoretical low-energy spectra exhibit two resonance-like structures. The first
(narrow) is the excitation of the well-known three-body resonance. The
second (broad) bump is a composition of overlapping soft modes of
multipolarities whose relative weights depend on
transferred momentum and reaction type. Inelastic scattering is the most
selective tool for studying the soft dipole excitation mode.Comment: Submitted to Phys. Rev. C., 11 figures using eps
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