scholarly journals Low -parametric equation for calculating the viscosity coefficient of nitrogen in liquid, gas and fluid states

2021 ◽  
Vol 2119 (1) ◽  
pp. 012143
Author(s):  
O S Dutova ◽  
A B Meshalkin
Keyword(s):  
Energy Density ◽  
Internal Energy ◽  
Viscosity Coefficient ◽  
Parametric Equation ◽  
New Correlation

Abstract The formulation for the viscosity coefficient of nitrogen is obtained. In the developed equation the dependence of the residua viscosity of various states of substance on the internal energy density is used. The new correlation represents the viscosity of nitrogen at temperatures from 70 K to 1000 K and pressures of up to 50 MPa within the limits of experimental uncertainties.

Characterization of the internal energy density in Mie scattering

1991 ◽  
Vol 8 (10) ◽  
pp. 1553 ◽  
Author(s):  
H. M. Lai ◽  
P. T. Leung ◽  
K. L. Poon ◽  
K. Young
Keyword(s):  
Energy Density ◽  
Internal Energy ◽  
Mie Scattering

scholarly journals Viscous Matter in FRW Cosmology

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1269
Author(s):  
Marek Szydłowski ◽  
Adam Krawiec
Keyword(s):  
Energy Density ◽  
Exact Solutions ◽  
Viscosity Coefficient ◽  
Chaplygin Gas ◽  
Dynamical Problem ◽  
Frw Cosmology ◽  
Singularity Problem ◽  
Viscosity Effects ◽  
Simple Theorem ◽  
Standard Cosmological Model

We investigate the dynamics of dust matter with bulk viscosity effects. We explored the analogy dynamical problem to Chaplygin gas. Due to this analogy we give exact solutions for the FRW cosmology with viscosity coefficient parameterized by the Belinskii–Khalatnikov power law dependence with respect to energy density. These exact solutions are given in the form of hypergeometrical functions. We proved simple theorem which illustrated as viscosity effects can solved the initial singularity problem present in standard cosmological model.

Further comments on the equivalence of Abraham's, Minkowski's, and others' electrodynamics

1980 ◽  
Vol 58 (8) ◽  
pp. 1163-1170 ◽  
Author(s):  
Gérard A. Maugin
Keyword(s):  
Energy Density ◽  
Total Energy ◽  
Mechanical Behavior ◽  
Internal Energy ◽  
Closed System ◽  
Ad Hoc ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Electromagnetic Energy ◽  
Time Decomposition

Arguments recently proposed by Kranyš concerning the nondistinguishability between Abraham's and Minkowski's electromagnetic contributions to the total energy-momentum tensor of the same relativistic, thermodynamically closed system are extended to other electromagnetic energy-momentum tensors (as proposed by Grot and Eringen and de Groot and Suttorp). The adjustment of the corresponding "matter" contribution, which occurs in each element of the canonical space-time decomposition of the total energy-momentum tensor, is exhibited in those different cases. For dissipation-free systems this adjustment can be achieved for each case by means of an ad hoc Legendre transformation on the internal energy density. The arguments used do not presuppose any isotropy and linearity of the medium and can be readily extended to the cases of media with hysteresis and media endowed with intrinsic spins, be they of a fluid-like or solid-like type of mechanical behavior.

scholarly journals SN Heating Efficiency of the ISM of Starburst Galaxies

2004 ◽  
Vol 217 ◽  
pp. 324-325 ◽  
Author(s):  
C. Melioli ◽  
E. M. de Gouveia Dal Pino ◽  
A. D'Ercole ◽  
A. Raga
Keyword(s):  
Energy Density ◽  
Internal Energy ◽  
Starburst Galaxies ◽  
Expansion Velocity ◽  
Heating Efficiency ◽  
Available Energy ◽  
Phase Medium ◽  
Ambient Gas ◽  
Hydrodynamical Simulations ◽  
Successive Generations

The interstellar medium heated by supernova explosions (SN) may acquire an expansion velocity larger than the escape velocity and leave the galaxy through a supersonic wind. Galactic winds are effectively observed in many local starburst galaxies (Lehnert & Heckman 1996). The SN ejecta are transported out of the galaxies by such winds which must affect the chemical evolution of the galaxies. The effectiveness of the processes mentioned above depends on the heating efficiency (HE) of the SNs, i.e., the ratio between the kinetic plus internal energy density of the ambient gas and the SN energy density. In a starburst region, several SN explosions occur at a large rate inside a relatively small volume. If the successive generations of SN remnants (SNRs) interact with each other very fast, then a superbubble of high temperature and low density will rapidly develop, before a significant increase of the ambient gas density that could lead to substantial losses of energy by radiation. In this case, it is common to assume a value for HE of the order of unity, since most of the available energy of the SNs will be transferred to the ambient gas in the form of kinetic and internal energy, instead of being radiated away. However this assumption fails to reproduce both the chemical and dynamical characteristics of most starburst (SB) galaxies. In order to solve this paradigm, we have constructed a simple semi-analytical model, considering the essential ingredients of a SB environment, i.e., a three-phase medium composed by hot diffuse gas, SNRs and clouds, which is able to qualitatively trace the thermalisation history of the ISM in a SB region and determine the HE evolution (Melioli, de Gouveia Dal Pino, & D'Ercole, A&A, 2003, submitted). Our study has also been accompanied by fully 3-D radiative cooling, hydrodynamical simulations of SNR-SNR and SNR-clouds interactions (see Melioli, de Gouveia Dal Pino, & Raga 2003, in preparation).

scholarly journals ON THE ROLE OF VISCOSITY IN EARLY COSMOLOGY

2008 ◽  
Vol 23 (08) ◽  
pp. 1248-1252
Author(s):  
NAKIA CARLEVARO ◽  
GIOVANNI MONTANI
Keyword(s):  
Energy Density ◽  
Power Law ◽  
Bulk Viscosity ◽  
Viscosity Coefficient ◽  
Hydrodynamic Equations ◽  
Restricted Domain ◽  
Asymptotic Approach ◽  
Cosmological Singularity ◽  
Second Order In Time

We present a discussion of the effects induced by bulk viscosity on the very early Universe stability. The viscosity coefficient is assumed to be related to the energy density ρ via a power-law of the form ζ = ζ0ρs (where ζ0, s = const.) and the behavior of the density contrast in analyzed. In particular, we study both Einstein and hydrodynamic equations up to first and second order in time in the so-called quasi-isotropic collapsing picture near the cosmological singularity. As a result, we get a power-law solution existing only in correspondence to a restricted domain of ζ0. The particular case of pure isotropic FRW dynamics is then analyzed and we show how the asymptotic approach to the initial singularity admits an unstable collapsing picture.

scholarly journals MAGNETOELECTRIC PONDEROMOTIVE FORCE

2013 ◽  
Vol 27 (21) ◽  
pp. 1350150 ◽  
Author(s):  
SYLVAIN D. BRECHET ◽  
ALEXANDRE ROULET ◽  
JEAN-PHILIPPE ANSERMET
Keyword(s):  
Energy Density ◽  
Internal Energy ◽  
Electromagnetic Fields ◽  
Continuity Equation ◽  
Ponderomotive Force ◽  
Nonrelativistic Limit ◽  
Local Scale ◽  
Magnetoelectric Coupling ◽  
Electric And Magnetic Fields ◽  
Ponderomotive Forces

The dynamics of a system consisting of a matter continuum with a weak linear magnetoelectric coupling interacting with electromagnetic fields is examined on a local scale in a nonrelativistic limit. A consistent expression for the internal energy of the system is derived. The internal energy density and the continuity equation for the momentum lead to the derivation of ponderomotive forces. A nonuniform magnetoelectric coupling generates a "magnetoelectric" ponderomotive force that could be distinguished from the purely electric or magnetic ponderomotive forces by applying alternating electric and magnetic fields at distinct frequencies.

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