We are in the process of updating and extending the OPAL equation-of-state (EOS) and opacity data to include low-mass stars. The EOS part of that effort now is complete, and the results are described herein. The new data cover main-sequence stars having mass � 0.1 M� . As a result of the more extreme matter conditions encountered with low-mass stars, we have added new physics. The electrons are now treated as relativistic, and we have improved our treatment of molecules. We also consider the implications of the new results for helioseismology.

http://iopscience.iop.org/article/10.1086/341894/pdf

Updated and Expanded OPAL Equation-of-State Tables: Implications for Helioseismology

The constrained interpolation profile method for multiphase analysis

A universal solver for hyperbolic equations by cubic-polynomial interpolation I. One-dimensional solver

Two semi-Lagrangian schemes that guarantee exactly mass conservation are proposed. Although they are in a nonconservative form, the interpolation functions are constructed under the constraint of conservation of cell-integrated value (mass) that is advanced by remapping the Lagrangian volume. Consequently, the resulting schemes conserve the mass for each computational grid cell. One of them (CIP–CSL4) is the direct extension of the original cubic-interpolated propagation (CIP) method in which a cubic polynomial is used as the interpolation function and the gradient is calculated according to the differentiated advection equation. A fourth-order polynomial is employed as the interpolation function in the CIP–CSL4 method and mass conservation is incorporated as an additional constraint on the reconstruction of the interpolation profile. In another scheme (CIP–CSL2), the CIP principle is applied to integrated mass and the interpolation function becomes quadratic. The latter one can be readily extend...

F. Ikeda

Papers

A universal solver for hyperbolic equations by cubic-polynomial interpolation. II, Two- and three-dimensional solvers

On some properties of Finsler spaces based on the indicatrices