Equation Of State For Density Research Articles

Quantum Statistical Entropy of Five-Dimensional BlackHole

The generalized uncertainty relation is introduced to calculatequantum statistic entropy of a black hole. By using thenew equation of state density motivated by the generalizeduncertainty relation, we discuss entropies of Bose field and Fermifield on the background of the five-dimensional spacetime. In ourcalculation, we need not introduce cutoff. There is not thedivergent logarithmic term as in the original brick-wall method. Andit is obtained that the quantum statistic entropy corresponding toblack hole horizon is proportional to the area of the horizon.Further it is shown that the entropy of black hole is the entropy ofquantum state on the surface of horizon. The black hole's entropyis the intrinsic property of the black hole. The entropy is aquantum effect. It makes people further understand the quantum statistic entropy.

The generalized uncertainty relation and the thermodynamic quantities near the black holes

The thermodynamic quantities of massless scalar, neutrino, electromagnetic, massless Rarita-Schwinger and gravitational fields near the general spherically symmetric static black holes are investigated by using the modified equation of state density due to the generalized uncertainty relation. It is shown that the thermodynamic quantities depend not only on the characteristic of the black hole but also on the spin of the fields and the size of minimal length.

Uncertainty relation and black hole entropy of Kerr spacetime

The properties of thermal radiation are discussed by using a new equation of state density, which is motivated by the generalized uncertainty relation in the quantum gravity. There is no burst at the last stage of the emission of Kerr black hole. When the new equation of state density is utilized to investigate the entropy of a Bosonic field and Fermionic field outside the horizon of a static Kerr black hole, the divergence appearing in the brick wall model is removed, without any cutoff. The entropy proportional to the horizon area is derived from the contribution of the vicinity of the horizon.

Entropy of Nonstatic Black Hole with the Internal GlobalMonopole and the Generalized Uncertainty Relation

The new equation of state density is obtained by the utilization of thegeneralized uncertainty relation. With the help of coordinates and theWentzel–Kramers–Brillouin approximation, direct calculation of thescalar field entropy of the non-state black hole with an internalglobal monopole is performed. The entropy obtained from the calculationis proportional to the horizon area. The calculation can be free fromconvergence if without any cutoff, which is different from thebrick-wall method. However, the pertinent result is limited.

Quantum Entropy of Black Hole with Internal Global Monopole

Using the generalized uncertainty relation, the new equation of statedensity is obtained, and then the entropy of black hole with an internalglobal monopole is discussed. The divergence that appears in black holeentropy calculation through original brick-wall model is overcome. Theresult of the direct proportion between black hole entropy and its eventhorizon area is drawn and given. The result shows that the black holeentropy must be the entropy of quantum state near the event horizon.

Uncertainty relation and black-hole entropy of NUT-Kerr-Newman space-time

In this paper, by using the quantum-statistical method and the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity, we directly obtain the partition function of the Bose field and the Fermi field on the background of the axisymmetrical NUT-Kerr-Newman black hole. Then we calculate the entropy of the Bose field and the Fermi field of the black hole near the horizon. And it is obtained that the entropy of the black hole is proportional to the area of the horizon. The inherent contact between the entropy of the black hole and the area of the horizon is opened out. It is shown the entropy of the black hole is the entropy of the quantum state on the surface of the horizon. The entropy is a quantum effect. The fact that the state density diverges near the horizon is removed by introducing the generalized uncertainty relation showing that the brick-wall method is related to quantization of the quantum field.

UNCERTAINTY RELATION AND BLACK HOLE ENTROPY OF TOROIDAL SPACETIME

By using the method of quantum statistics and via the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity, we avoid the difficulty of solving wave equation, and directly derive the partition functions of bosonic and fermionic field in Toroidal black hole. Then we calculate the entropies of bosonic and fermionic field near the black hole horizon on the background of a black hole. In our result, the divergent logarithmic term and ultraviolet cutoff in the original brick-wall method by which the black hole entropy was derived no longer exist. It is shown that the entropy of the black hole is proportional to the area of the horizon. These results are similar to that in the black hole with horizon topology S2.

Letter: Dilatonic Black Hole Entropy Without Brick Walls

The properties of the thermal radiation are discussed by using the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity. There is no burst at the last stage of the emission of dilatonic black hole. When the new equation of state density is utilized to investigate the entropy of a bosonic field and fermionic field outside the horizon of a static dilatonic black hole, the divergence appearing in the brick wall model is removed, without any cutoff. It is derived from the contribution of the vicinity of the horizon that the entropy is proportional to the horizon area.

Reissner-Nordström black-hole entropy without brick walls

The properties of the thermal radiation are discussed by using the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity. There is no burst at the last stage of the emission of the Reissner-Nordstrom black hole. When the new equation of state density is utilized to investigate the entropy of a bosonic field and a fermionic field outside the horizon of a static Reissner-Nordstrom black hole, the divergence appearing in the brick wall model is removed, without any cut-off. The entropy proportional to the horizon area is derived from the contribution of the vicinity of the horizon.

Spherically symmetric black-hole entropy without brick walls

Properties of the thermal radiation of black holes are discussed using a new equation of state density motivated by the generalized uncertainty relation in quantum gravity. There is no burst at the last stage of emission from a spherically symmetric black hole. When the new equation of state density is used to investigate the entropy of a bosonic field and fermionic field outside the horizon of a static spherically symmetric black hole, the divergence that appears in the brick-wall model is removed without any cutoff. The entropy proportional to the horizon area is derived from the contribution from the vicinity of the horizon.

Black hole entropy without brick walls

The properties of the thermal radiation are discussed by using the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity. There is no burst at the last stage of the emission of a Schwarzschild black hole. When the new equation of state density is utilized to investigate the entropy of a scalar field outside the horizon of a static black hole, the divergence appearing in the brick wall model is removed, without any cutoff. The entropy proportional to the horizon area is derived from the contribution of the vicinity of the horizon.

Measurement of thermal diffusivities with the photoacoustic effect

A non-resonant photoacoustic detector was used to determine thermal diffusivities of the refrigerants R134a and R32. The measurements were carried out at temperatures ranging from 294 K to 363 K at pressures close to the dilute gas region. The uncertainty for the experimental data of R134a and R32 is ±1.25%. With the aid of accurate equations of state for density and isochoric heat capacity, the measured thermal diffusivities were converted into thermal conductivities. Further improvements of the experimental setup were outlined leading to an uncertainty of ±0.65% with respect to thermal diffusivity.

The high density equation of state and solid-fluid equilibrium in systems of freely jointed chains of tangent hard spheres

We present a study of the solid-fluid phase equilibrium for systems of freely jointed chains of tangent hard spheres using Monte Carlo computer simulation. Extensive calculations of the fluid and solid phase equations of state have been made. Our results for the fluid properties are compared with various theoretical equations of state which have been proposed for these systems. A method for calculating the solid phase free energy of chain molecules has been developed based on finding a reversible path to an Einstein crystal. The stable solid phase structure of these systems approximates cubic close packing of the atoms without long range orientational ordering of the bond vectors. The contribution to the solid phase free energy from the configurational degeneracy has been approximated by the expression developed by Huggins. The dependence of the solid phase thermodynamics upon the chain conformation has been studied and solid-fluid phase diagrams for chains with lengths ranging from three through eight atoms have been determined.

Low density equation of state of asymmetric hard sphere mixtures

Low density equation of state of asymmetric hard sphere mixtures

Low density equation of state of asymmetric hard sphere mixtures

The equation of state of highly asymmetric hard sphere mixtures at low and moderate densities is investigated using NpT Monte Carlo simulations. The discrepancies of the estimated fifth virial coefficient with the reported values of Saija et al. (Saija, F., Fiumara, G. and Giaquinta, P. V., 1996, Molec. Phys., 89, 1181) led us to compute such a coefficient. The new results are fully compatible with the compressibility factors estimated by Monte Carlo simulation and show excellent agreement with the predicted coefficients from the Boublik and Mansoori et al. equation of state.

The study of bubble formation in 316L stainless steel irradiated with helium ions at 873 K

Samples of solution annealed (SA) and 20% cold worked (CW) 316L austenitic stainless steel were irradiated with 2.5 MeV helium ions at 873 K. The ion fluence is 2.0 × 10 17 ions/cm 2 and flux is 2.11 × 10 12 ions/cm 2s. The bubble morphology and distribution along ion penetrating depth were observed with transmission electron microscope (TEM). Bubbles are faceted and the mechanism underlying bubble nucleation seems to be in the transition regime of di-atomic nucleation and multi-atomic nucleation in the SA sample. Helium depth distribution was deduced from the measured bubble size and density with the help of high density equation of state for helium. At the same irradiation condition, dislocations introduced in the CW sample before irradiation can increase bubble nucleation rate and decrease bubble growth rate. The swelling produced by bubbles is smaller in CW sample.

Pions, Supernovae, and the Supranuclear Matter Density Equation of State

We discuss the general trends that result from including pions in the supranuclear matter density equation of state we use to evolve supernovae. Although we find the overall characteristics of the supernovae evolution largely unchanged, we do see in the supranuclear density region of a supernova core, the temperature and electron neutrino number density increasing by about 10% and 160%, respectively, over a similar calculation where pions are neglected. These changes increase the neutrino luminosity and thus increase the explosion energy. The explanation for this behavior, as well as a thorough discussion of pion model we use, are the main topics of this paper

Equation of state for weakly nonideal plasmas

AbstractUsing a Green's function approach a low density equation of state is derived for quantum plasmas up to the order (e2n)5/2.

Computational aspects of a non-cubic equation of state for phase-equilibrium calculations. Effect of density-dependent mixing rules

An efficient procedure is presented for solving a non-cubic equation of state for density. In phase-equilibrium calculations, the costly computing step is not the density calculation but the calculation of the equation-of-state constants for the mixture. Illustrative calculations are given for high-pressure phase equilibria for hydrogen/ethane and methane/water. These calculations show the superiority of non-cubic equations with density-dependent mixing rules.

Comment on rotating fluid spheres

Recently, the slow rotation equation was solved for the uniform gravitational mass density equation of state and the results compared to a slow rotational approximation of the Wahlquist interior. The author shows the results are incorrect as they stand.