Alfv\'en wave-driven wind from RGB and AGB stars

We develop a magnetohydrodynamical model of Alfv\'en wave-driven wind in open magnetic flux tubes piercing the stellar surface of Red Giant Branch (RGB) and Asymptotic Giant Branch (AGB) stars, and investigate the physical properties of the winds. The model simulations are carried out along the evolutionary tracks of stars with initial mass in the range of 1.5 to 3.0 $M_{\odot}$ and initial metallicity $Z_{\rm ini}$=0.02. The surface magnetic field strength being set to be 1G, we find that the wind during the evolution of star can be classified into the following four types; the first is the wind with the velocity higher than 80 km s$^{-1}$ in the RGB and early AGB (E-AGB) phases; the second is the wind with outflow velocity less than 10 km s$^{-1}$ seen around the tip of RGB or in the E-AGB phase; the third is the unstable wind in the E-AGB and thermally pulsing AGB (TP-AGB) phases; the fourth is the stable massive and slow wind with the mass-loss rate higher than 10$^{-7} M_{\odot}$ yr$^{-1}$ and the outflow velocity lower than 20 km s$^{-1}$ in the TP-AGB phase. The mass-loss rates in the first and second types of wind are two or three orders of magnitude lower than the values evaluated by an empirical formula. The presence of massive and slow wind of the fourth type suggests the possibility that the massive outflow observed in TP-AGB stars could be attributed to the Alfv\'en wave-driven wind.Comment: 17 pages, 15 figures, accepted for publication in Ap

Sensitivity of T2KK to the non-standard interaction in propagation

Assuming only the non-zero electron and tau neutrino components $\epsilon_{ee}$, $\epsilon_{e\tau}$, $\epsilon_{\tau\tau}$ of the non-standard matter effect and postulating the atmospheric neutrino constraint $\epsilon_{\tau\tau}=|\epsilon_{e\tau}|^2/(1+\epsilon_{ee})$, we study the sensitivity to the non-standard interaction in neutrino propagation of the T2KK neutrino long-baseline experiment. It is shown that T2KK can constrain the parameters $|\epsilon_{ee}|\lesssim 1$, $|\epsilon_{e\tau}|\lesssim 0.2$. It is also shown that if $|\epsilon_{e\tau}|$ and $\theta_{13}$ are large, then T2KK can determine the Dirac phase and the phase of $\epsilon_{e\tau}$ separately, due to the information at the two baselines. We also provide an argument that the components $|\epsilon_{\alpha\mu}|$ $(\alpha=e,\mu,\tau)$ must be small for the disappearance oscillation probability to be consistent with high-energy atmospheric neutrino data, which justifies our premise that these quantities are negligible.Comment: 29 pages, 25 figures, uses revtex4-1. Several places including typos revised. New references adde

A Study Of Surface Dynamics Of Polymers. II. Investigation By Plasma Surface Implantation Of Fluorine–containing Moieties

Macromolecules at the surface of a polymeric solid have considerable mobility, and the specific arrangement of functional groups of macromolecules at the surface is dictated by the environmental conditions in which the surface is placed. Consequently, the change of environmental conditions, such as immersion in water or placement in a biological surrounding, could cause a considerable degree of change in the surface characteristics of a polymer from those evaluated in the laboratory against ambient air. The mobile nature of a polymer surface can be investigated by surface‐implanting fluorine‐containing moieties, mainly—CF3, by the plasma implantation technique and following the disappearance and reappearance of fluorine atoms on the surface. The disappearance rates (based on the immersion time in water at room temperature) of ESCA F1s signals, the decay rates of (advancing) contact angle of water, and the recovery of these values on heat treatment of water‐immersed samples were measured as a function of crystallinity of polymer samples (at three levels of crystallinity) for poly (ethylene terephthalate) and nylon 6. Copyright © 1988 John Wiley & Sons, Inc

Nuclear effects in Neutrino Nuclear Cross-sections

Nuclear effects in the quasielastic and inelastic scattering of neutrinos(antineutrinos) from nuclear targets have been studied. The calculations are done in the local density approximation which take into account the effect of nucleon motion as well as renormalisation of weak transition strengths in the nuclear medium. The inelastic reaction leading to production of pions is calculated in a $\Delta$ dominance model taking into account the renormalization of $\Delta$ properties in the nuclear medium.Comment: 4 pages,3 figures, Ninth International Workshop on Neutrino Factories, Superbeams and Betabeams (NuFact07), August 6-11, 2007, Okayama University, Okayama, Japa

Field Induced Multiple Reentrant Quantum Phase Transitions in Randomly Dimerized Antiferromagnetic S=1/2 Heisenberg Chains

The multiple reentrant quantum phase transitions in the $S=1/2$ antiferromagnetic Heisenberg chains with random bond alternation in the magnetic field are investigated by the density matrix renormalization group method combined with the interchain mean field approximation. It is assumed that the odd-th bond is antiferromagnetic with strength $J$ and even-th bond can take the values {\JS} and {\JW} ({\JS} > J > {\JW} > 0) randomly with probability $p$ and $1-p$, respectively. The pure version ($p=0$ and $p=1$) of this model has a spin gap but exhibits a field induced antiferromagnetism in the presence of interchain coupling if Zeeman energy due to the magnetic field exceeds the spin gap. For $0 < p < 1$, the antiferromagnetism is induced by randomness at small field region where the ground state is disordered due to the spin gap in the pure case. At the same time, this model exhibits randomness induced plateaus at several values of magnetization. The antiferromagnetism is destroyed on the plateaus. As a consequence, we find a series of reentrant quantum phase transitions between the transverse antiferromagnetic phases and disordered plateau phases with the increase of the magnetic field for moderate strength of interchain coupling. Above the main plateaus, the magnetization curve consists of a series of small plateaus and the jumps between them, It is also found that the antiferromagnetism is induced by infinitesimal interchain coupling at the jumps between the small plateaus. We conclude that this antiferromagnetism is supported by the mixing of low lying excited states by the staggered interchain mean field even though the spin correlation function is short ranged in the ground state of each chain.Comment: 5 pages, 8 figure

In situ imaging of microstructure formation in electronic interconnections

The development of microstructure during melting, reactive wetting and solidification of solder pastes on Cu-plated printed circuit boards has been studied by synchrotron radiography. Using Sn-3.0Ag-0.5Cu/Cu and Sn-0.7Cu/Cu as examples, we show that the interfacial Cu6Sn5 layer is present within 0.05 s of wetting, and explore the kinetics of flux void formation at the interface between the liquid and the Cu6Sn5 layer. Quantification of the nucleation locations and anisotropic growth kinetics of primary Cu6Sn5 crystals reveals a competition between the nucleation of Cu6Sn5 in the liquid versus growth of Cu6Sn5 from the existing Cu6Sn5 layer. Direct imaging confirms that the β-Sn nucleates at/near the Cu6Sn5 layer in Sn-3.0Ag-0.5Cu/Cu joints