Corrections to linear mixing in binary ionic mixtures and plasma screening at zero separation

Using the results of extensive Monte Carlo simulations we discuss corrections to the linear mixing rule in strongly coupled binary ionic mixtures. We analyze the plasma screening function at zero separation, H_{jk}(0), for two ions (of types j=1,2 and k=1,2) in a strongly coupled binary mixture. The function H_{jk}(0) is estimated by two methods: (1) from the difference of Helmholtz Coulomb free energies at large and zero separations; (2) by fitting the Widom expansion of H_{jk}(x) in powers of interionic distance x to Monte Carlo data on the radial pair distribution function g_{jk}(x). These methods are shown to be in good agreement. For illustration, we analyze the plasma screening enhancement of nuclear burning rates in dense stellar matter.Comment: 4 pages, 2 figures, pre-peer reviewed version of the article accepted for publication in Contrib. Plasma Phys. (2009). The results can be applied to plasma screening enhancement of nuclear burning rates in dense stellar matte

Collecting \u3ci\u3eNeocurtilla Hexadactyla\u3c/i\u3e, the Northern Mole Cricket (Orthoptera: Gryllidae), in Iowa

(excerpt) The northern mole cricket, Neocurtilla hexadactyla (Perty), is a common insect that is infrequently collected perhaps owing to its burrowing and nocturnal habits. It tunnels into moist soil and feeds on tender roots, earthworms, or various insect larvae (Blatchley, 1920)

Green development: improving the health of residents and neighborhoods

Building sustainable developments for long-term savings and better community healthArchitecture and energy conservation ; Housing - Boston

Vincent Van Gogh\u27s Personal Possession

I am an amatuer artist, so when I was in Arles in southern France, it was nat­ural. for me to want to see all the places thereabouts that the famous Dutch painter Vincent van Gogh had been concerned with when he lived there in 1888

Klein-Gordon-Wheeler-DeWitt-Schroedinger Equation

We start from the Einstein-Hilbert action for the gravitational field in the presence of a "point particle" source, and cast the action into the corresponding phase space form. The dynamical variables of such a system satisfy the point particle mass shell constraint, the Hamilton and the momentum constraints of the canonical gravity. In the quantized theory, those constraints become operators that annihilate a state. A state can be represented by a wave functional $\Psi$ that simultaneously satisfies the Klein-Gordon and the Wheeler-DeWitt-Schr\"odinger equation. The latter equation, besides the term due to gravity, also contains the Schr\"odinger like term, namely the derivative of $\Psi$ with respect to time, that occurs because of the presence of the point particle. The particle's time coordinate, $X^0$, serves the role of time. Next, we generalize the system to $p$-branes, and find out that for a quantized spacetime filling brane there occurs an effective cosmological constant, proportional to the expectation value of the brane's momentum, a degree of freedom that has two discrete values only, a positive and a negative one. This mechanism could be an explanation for the small cosmological constant that drives the accelerated expansion of the universe.Comment: 14 pages; typos corrected; journal reference include

Quantum Gravity Without Ghosts

An outline is given of a recently discovered technique for building a quantum effective action that is completely independent of gauge-fixing choices and ghost determinants. One makes maximum use of the geometry and fibre-bundle structure of the space of field histories and introduces a set of nonlocal composite fields: the geodesic normal fields based on Vilkovisky's connection on the space of histories. The closed-time-path formalism of Schwinger, Bakshi, Mahantappa {\it et al} can be adapted for these fields, and a set of gauge-fixing-independent dynamical equations for their expectation values (starting from given initial conditions) can be computed. An obvious application for such equations is to the study of the formation and radiative decay of black holes, and to other back-reaction problems.Comment: This is a paper submitted to the Gravity Research Foundation Essay Competition of 1998 that received Honorable Mentio