Possible Enhanced Flux of Glassy Solid Helium in Cylindrical Corrugated Nanopores

By using the glassy (helium-)fluid model and boundary perturbation method, we can obtain the velocity fields (as well as the flow rate; up to the second order) inside the wavy-rough cylindrical nanopores which are of the same size as those samples prepared by Kim and Chan as well as Day {\it et al.} Our results show that the velocities measured in porous Vycor samples could be reproduced by carefully selecting relevant parameters but those in glass capillaries are difficult to obtain.Comment: 2 figure

Dispersion Relations for Waves propagating in Composite Fermion Gases

The discrete Uehling-Uhlenbeck equations are solved to study the propagation of plane (sound) waves in a system of composite fermionic particles with hard-sphere interactions and the filling factor ($\nu$) being 1/2. The Uehling-Uhlenbeck collision sum, as it is highly nonlinear, is linearized firstly and then decomposed by using the plane wave assumption. We compare the dispersion relations thus obtained by the relevant Pauli-blocking parameter $B$ which describes the different-statistics particles for the quantum analog of the discrete Boltzmann system when $B$ is positive (Bose gases), zero (Boltzmann gases), and negative (Fermi Gases). We found, as the effective magnetic field being zero ($\nu$=1/2 using the composite fermion formulation), the electric and fluctuating (induced) magnetic fields effect will induce anomalous dispersion relations.Comment: 13 pages with 2 figure

Comments on "Attainable conditions and exact invariant for the time-dependent harmonic oscillator"

We make remarks on Fern\'{a}ndez Guasti's paper [{\it J. Phys. A: Math. Gen.} 39 (2006) 11825-11832] by pointing out some mistakes Fern\'{a}ndez Guasti derived therein.Comment: Comments for ; 2 Pages in tota

Phantom Thermodynamics Revisited

Although generalized Chaplygin phantom models do not show any big rip singularities, we investigated k-essence models together with noncanonical kinetic energy for which there might be a big rip future singularity in the phantom region. We present our results by finely tuning the parameter ($\beta$) which is closely related to the canonical kinetic term in $k$-essence formalism. The scale factor $a(t)$ could be negative and decreasing within a specific range of $\beta$ during the initial evolutional period. There will be no singularity for the scale factor for all times once $\beta$ is carefully selected.Comment: 4 pages; 1 figur

Possible Pressure Effect for Superconductors

We make an estimate of the possible range of $\Delta T_c$ induced by high-pressure effects in post-metallic superconductors by using the theory of {\it extended irreversible/reversible thermodynamics} and Pippard's length scale. The relationship between the increment of the superconducting temperature and the increase of the pressure is parabolic.Comment: 6 pages; 1999-March result

Possible Orientation Effects to Phase Diagram of Strange Matter

We obtain possibly valuable information about the orientation-tuning of phase diagram of superdense nuclear matter at high fermion as well as boson number density but low temperature, which is not accessible to relativistic heavy ion collision experiments. Our results resemble those proposed before by Alford. Possible observational signatures associated with the theoretically proposed states of matter inside compact stars are discussed as well.Comment: 3 Figures; 2006-Jan. work

Stability of Quantum Fluids : Wavy Interface Effect

A numerical investigation for the stability of the incompressible slip flow of normal quantum fluids (above the critical phase transition temperature) inside a microslab where surface acoustic waves propagate along the walls is presented. Governing equations and associated slip velocity and wavy interface boundary conditions for the flow of normal fluids confined between elastic wavy interfaces are obtained. The numerical approach is an extension (with a complex matrix pre-conditioning) of the spectral method. We found that the critical Reynolds number ($Re_{cr}$ or the critical velocity) decreases significantly once the slip velocity and wavy interface effects are present and the latter is dominated ($Re_{cr}$ mainly depends on the wavy interfaces).Comment: 4 Figures; 2004-Jan work

Possible Structures of Sprites

Upon using the hydrodynamic analog we can derive some families of stationary Beltrami field-like solutions from the free Maxwell equations in vacuum. These stationary electromagnetic fields are helical and/or column-like once they are represented in a suitable frame of reference. Possible dendritic and jelly-fish-like patterns of sprites are demonstrated.Comment: 2005 Feb. works; 5 figure

Transport induced by Density Waves in a Andreev-Lifshitz Supersolid

Macroscopic derivation of the entrainment in in a Andreev-Lifshitz Supersolid induced by a surface elastic wave propagating along the flexible interface is conducted by considering the nonlinear coupling between the interface and the rarefaction effect. We obtain the critical bounds for zero-volume-flow-rate states corresponding to specific rarefaction measure and wave number which is relevant to the rather small critical velocity of supersolid flows reported by Kim and Chan.Comment: 2 Figures in total, 2006-March work

Possible Negative Pressure States in the Evolution of the Universe

Hydrodynamic derivation of the entrainment of matter induced by a surface elastic wave propagating along the flexible vacuum-matter interface is conducted by considering the nonlinear coupling between the interface and the rarefaction effect. The critical reflux values associated with the product of the second-order (unit) body forcing and the Reynolds number (representing the viscous dissipations) decrease as the Knudsen number (representing the rarefaction measure) increases from zero to 0.1. We obtained the critical bounds for matter-freezed or zero-volume-flow-rate states corresponding to specific Reynolds numbers (ratio of wave inertia and viscous dissipation effects) and wave numbers which might be linked to the evolution of the Universe. Our results also show that for positive evolution of the matter (the maximum speed of the matter (gas) appears at the center-line) there might be existence of negative pressure.Comment: 4 Figures in tota