566 research outputs found
Interactions of C+(2PJ) with rare gas atoms: incipient chemical interactions, potentials and transport coefficients
Accurate interatomic potentials were calculated for the interaction of a singly charged carbon cation, C+, with a single rare gas atom, RG (RG = Ne–Xe). The RCCSD(T) method and basis sets of quadruple-ζ and quintuple-ζ quality were employed; each interaction energy was counterpoise corrected and extrapolated to the basis set limit. The lowest C+(2P) electronic term of the carbon cation was considered, and the interatomic potentials calculated for the diatomic terms that arise from these: 2Π and 2Σ+. Additionally, the interatomic potentials for the respective spin-orbit levels were calculated, and the effect on the spectroscopic parameters was examined. In doing this, anomalously large spin-orbit splittings for RG = Ar–Xe were found, and this was investigated using multi-reference configuration interaction calculations. The latter indicated a small amount of RG → C+ electron transfer and this was used to rationalize the observations. This is taken as evidence of an incipient chemical interaction, which was also examined via contour plots, Birge–Sponer plots and various population analyses across the C+-RG series (RG = He–Xe), with the latter showing unexpected results. Trends in several spectroscopic parameters were examined as a function of the increasing atomic number of the RG atom. Finally, each set of RCCSD(T) potentials was employed, including spin-orbit coupling to calculate the transport coefficients for C+ in RG, and the results were compared with the limited available data
Stability and fluctuation modes of giant gravitons with NSNS B field
We study the stability of the giant gravitons in the string theory background
with NSNS B field. We consider the perturbation of giant gravitons formed by a
probe D brane in the background generated by D-D branes for
. We use the quadratic approximation to the brane action to find
the equations of motion. For , giant graviton configurations are stable
independent of the size of the brane. For , we calculated the range of
the size of the brane where they are stable. We also present the mode
frequencies explicitly for some special cases.Comment: 16 pages, spectrum of fluctuation modes included, title chang
Stability of Subsequent-to-Leading-Logarithm Corrections to the Effective Potential for Radiative Electroweak Symmetry Breaking
We demonstrate the stability under subsequent-to-leading logarithm
corrections of the quartic scalar-field coupling constant and the
running Higgs boson mass obtained from the (initially massless) effective
potential for radiatively broken electroweak symmetry in the
single-Higgs-Doublet Standard Model. Such subsequent-to-leading logarithm
contributions are systematically extracted from the renormalization group
equation considered beyond one-loop order. We show to be the dominant
coupling constant of the effective potential for the radiatively broken case of
electroweak symmetry. We demonstrate the stability of and the running
Higgs boson mass through five orders of successively subleading logarithmic
corrections to the scalar-field-theory projection of the effective potential
for which all coupling constants except the dominant coupling constant
are disregarded. We present a full next-to-leading logarithm
potential in the three dominant Standard Model coupling constants
(-quark-Yukawa, , and ) from these coupling constants'
contribution to two loop - and -functions. Finally, we
demonstrate the manifest order-by-order stability of the physical Higgs boson
mass in the 220-231 GeV range. In particular, we obtain a 231 GeV physical
Higgs boson mass inclusive of the -quark-Yukawa and coupling
constants to next-to-leading logarithm order, and inclusive of the smaller
gauge coupling constants to leading logarithm order.Comment: 21 pages, latex2e, 2 eps figures embedded in latex file. Updated
version contains expanded analysis in Section
Asymmetric Orbifolds, Noncommutative Geometry and Type I String Vacua
We investigate the D-brane contents of asymmetric orbifolds. Using T-duality
we find that the consistent description of open strings in asymmetric orbifolds
requires to turn on background gauge fields on the D-branes. We derive the
corresponding noncommutative geometry arising on such D-branes with mixed
Neumann-Dirichlet boundary conditions directly by applying an asymmetric
rotation to open strings with pure Dirichlet or Neumann boundary conditions. As
a concrete application of our results we construct asymmetric type I vacua
requiring open strings with mixed boundary conditions for tadpole cancellation.Comment: TeX, harvmac, 24 pages, 2 figures, v2: Clarifying remarks concerning
the identification of commutative and non-commutative theories on asymmetric
orbifolds; additional reference
The Iowa Homemaker vol.28, no.1
Housemothers Enjoy Personal Ties, Janet Sutherland, page 2
Your Hope Chest Plans, Jo Ann Breckenridge, page 3
Select Your Electives Now, Barbara Parson, page 4
With Spring – Sport’s The Thing, Barbara Allen, page 5
You Can Make Packing Fun, Patricia Close, page 7
Vicky Boasts – Bring On The Rain, Katherine Williams, page 8
Wee Listeners Join Radio Fans, Lee Ann Smiley, page 10
Zipper History Has Ups and Downs, Margaret Leveson, page 12
Simple Corsages That You Can Make, Emogene Olson, page 15
Keeping Up with Today, Mary West, page 1
World-Volume Interactions on D-Branes
We examine in detail various string scattering amplitudes in order to extract
the world-volume interactions of massless fields on a Dirichlet brane. We find
that the leading low-energy interactions are consistent with the Born-Infeld
and Chern-Simons actions. In particular, our results confirm that the
background closed string fields appearing in these actions must be treated as
functionals of the non-abelian scalar fields describing transverse fluctuations
of the D-brane.Comment: 14 page
Conformal Quivers and Melting Molecules
Quiver quantum mechanics describes the low energy dynamics of a system of
wrapped D-branes. It captures several aspects of single and multicentered BPS
black hole geometries in four-dimensional supergravity such
as the presence of bound states and an exponential growth of microstates. The
Coulomb branch of an Abelian three node quiver is obtained by integrating out
the massive strings connecting the D-particles. It allows for a scaling regime
corresponding to a deep AdS throat on the gravity side. In this scaling
regime, the Coulomb branch is shown to be an invariant
multi-particle superconformal quantum mechanics. Finally, we integrate out the
strings at finite temperature---rather than in their ground state---and show
how the Coulomb branch `melts' into the Higgs branch at high enough
temperatures. For scaling solutions the melting occurs for arbitrarily small
temperatures, whereas bound states can be metastable and thus long lived.
Throughout the paper, we discuss how far the analogy between the quiver model
and the gravity picture, particularly within the AdS throat, can be taken.Comment: 49 pages, 16 figure
Effects of sn-2 palmitic acid-fortified vegetable oil and fructooligosaccharide on calcium metabolism in growing rats fed casein based diet
This study was carried out to investigate the efficacy of sn-2 palmitic acid-fortified vegetable oil (Sn2PA) on calcium absorption and to confirm the synergistic effects of fructooligosaccharide on calcium absorption. Male SD rats were fed 6 kinds of casein based diets containing vegetable oil (control), sn-2 palmitic acid-fortified vegetable oil (Sn2PA) and Sn2PA with fructooligosaccharide(Sn2PAFO) in two levels of calcium (normal 0.5% and high 1.0%) for 3 weeks. Total lipids, cholesterol, triglyceride and calcium in blood were measured. Feces were collected using cages for 4 days. Serum concentrations of total lipids and calcium were not significantly different among groups. However, serum triglyceride was significantly decreased by fructooligosaccharide supplementation regardless of dietary calcium level. The lipid absorption was not significantly different among experimental groups. Calcium absorption was significantly higher in Sn2PAFO group than other groups. Calcium solubility of intestine was increased by sn-2 palmitic acid supplementation. These results suggest that sn-2 palmitic acid and fructooligosaccharide supplementation could be beneficial for baby foods including infant formula, with regard to increasing absorption of calcium by more soluble calcium in the small intestinal content
Hydrogen sulfide attenuates cardiac dysfunction in a rat model of heart failure: a mechanism through cardiac mitochondrial protection
HF (heart failure) after MI (myocardial infarction) is a major cause of morbidity and mortality worldwide. Recent studies have shown that hydrogen sulfide (H2S) has cardioprotective effects. Hence, we aimed to elucidate the potential effects of H2S on HF after MI in rats. The HF model after MI was made by ligating the left anterior descending coronary artery. HF groups and sham-operated groups of rats were treated with vehicle, sodium hydrosulfide (NaHS) or PAG (propagylglycine). Equal volumes of saline, 3.136 mg·kg−1·day−1 NaHS or 37.5 mg·kg−1·day−1 PAG, were intraperitoneally injected into rats for 6 weeks after operation. Survival, lung-to-body weight ratio and left ventricular haemodynamic parameters were measured. The protein and gene expression of Bcl-2, Bax, caspase 3 and cytochrome c were analysed by Western blotting and RT–PCR (reverse transcription–PCR). TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) and EM (electron microscopy) were used to examine apoptosis of heart tissues. NaHS was found to improve the survival and lower the lung-to-body weight ratio. It increased the LVSP (left ventricular systolic pressure) and the maximum rate of pressure and decreased LVEDP (left ventricular end-diastolic pressure). Furthermore, NaHS promoted Bcl-2 protein and mRNA expression and demoted Bax, caspase 3 protein and mRNA expression in HF rats. We also showed that NaHS decreased the leakage of cytochrome c protein from the mitochondria to the cytoplasm. Histological observation by TUNEL and EM proved that NaHS inhibited cardiac apoptosis in HF hearts and improved mitochondrial derangements, but that PAG aggravated those indices. Hence, H2S has protective effects in HF rats
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