Compressibility may strongly reduce the redistribution of turbulent kinetic energy. The question of how such effects can be taken into account in turbulence models is addressed here. First, a corresponding stochastic turbulence model is developed on the basis of a simplification of the generalized Langevin model for turbulent velocities. This model is then reduced to a deterministic model that ...

The dynamics of fluid particles on cylindrical manifolds is investigated. The velocity field is obtained by generalizing the isotropic Kraichnan ensemble, and is therefore Gaussian and decorrelated in time. The degree of compressibility is such that when the radius of the cylinder tends to infinity the fluid particles separate in an explosive way. Nevertheless, when the radius is finite the tra...

calculate some thermodynamic properties of molten polymers including specific volume and isothermal compressibility (S.M. Hoseini, Physical Chemistry & Electrochemistry, 2 (2014) 56-65). This work extended that EOS to predict the volumetric properties of some molten ethylene copolymers including ethylene/1-octene, ethylene/1-butene (xethylene equal to 0.8543 and 0.563), ethylene/propene. The ab...

The ultrasonic velocity (V), density (ρ) and viscosity (η) measurements of Hydroquinone in n-propanol and iso-propanol have been carried out for the study of solute-solvent interaction. Experimental data have been used to calculate the isentropic compressibility (bs), intermolecular free length (Lf), specific acoustic impedance (Z), molar sound velocity (R), relative association (RA) solvation ...

The ultrasonic velocity (U), density (ρ) and viscosity (η) have been measured for the binary liquid mixtures containing 2-(p-methoxy phenylsulphonyl)-4-methyl sydnone in Ethanol at 303.15K. From these data some of acoustical parameters such as adiabatic compressibility (β), free length (Lf), acoustic impedance (Z), relative association (RA), relaxation strength (r), Rao’s constant (R), molar co...

Electron-electron interactions generally reduce the low temperature resistivity due to the screening of the impurity potential by the electron gas. In the weak-coupling limit, the magnitude of this screening effect is determined by the thermodynamic compressibility which is proportional to the inverse screening length. We show that when strong correlations are present, although the compressibil...

The compressibility of Schur complement matrices is the essential ingredient for H-matrix techniques, and is well understood for Laplace type problems. The Helmholtz case is more difficult: there are several theoretical results which indicate when good compression is possible with additional techniques, and in practice sometimes basic H-matrix techniques work well. We investigate the compressib...

On the basis of quantum Monte Carlo (QMC) simulations we study the formation of Mott domains in the one-dimensional Hubbard model with an additional confining potential. We find evidences of quantum critical behavior at the boundaries of the Mott-insulating regions. A local compressibility defined to characterize the local phases exhibits a non-trivial critical exponent on entering the Mott-ins...

We have measured the local electronic compressibility of a two-dimensional hole gas as it crosses the B = 0 metal-insulator transition. In the metallic phase, the compressibility follows the mean-field Hartree-Fock (HF) theory and is found to be spatially homogeneous. In the insulating phase it deviates by more than an order of magnitude from the HF predictions and is spatially inhomogeneous. T...

The change of the compressibility at the glass transition Tg is evaluated from pressure experiments in the liquid and the glassy state of the ZrTiCuNiBe bulk metallic glass forming system. Via the enthalpy recovery method, we derive an increase of Tg with pressure of 3.6 KyGPa. Comparing the changes of the compressibility, the specific heat capacity, and the thermal expansion coefficient at Tg,...