Thermodynamic properties of an interacting hard-sphere Bose gas in a trap using the static fluctuation approximation

A hard-sphere (HS) Bose gas in a trap is investigated at finite temperatures in the weakly-interacting regime and its thermodynamic properties are evaluated using the static fluctuation approximation (SFA). The energies are calculated with a second-quantized many-body Hamiltonian and a harmonic oscillator wave function. The specific heat capacity, internal energy, pressure, entropy and the Bose-Einstein (BE) occupation number of the system are determined as functions of temperature and for various values of interaction strength and number of particles. It is found that the number of particles plays a more profound role in the determination of the thermodynamic properties of the system than the HS diameter characterizing the interaction, that the critical temperature drops with the increase of the repulsion between the bosons, and that the fluctuations in the energy are much smaller than the energy itself in the weakly-interacting regime.Comment: 34 pages, 24 Figures. To appear in the International Journal of Modern Physics

A HAMILTON-JACOBI TREATMENT OF DISSIPATIVE SYSTEMS

Dissipative systems are investigated within the framework of the Hamilton-Jacobi equation. The principal function is determined using the method of separation of variables. The equation of motion can then be readily obtained. Three examples are given to illustrate our formalism: the damped harmonic oscillator, a system with a variable mass, and a charged particle in a magnetic field

CANONICAL QUANTIZATION OF DISSIPATIVE SYSTEMS

The canonical method is invoked to quantize dissipative systems using the WKB approximation. The wave function is constructed such that its phase factor is simply Hamilton’s principal function. The energy eigenvalue is found to be in exact agreement with the classical case. To demonstrate our approach, the three examples considered in our previous work (ESJ 9(30), 70-81, 2013) are quantized in detail: the damped harmonic oscillator, a system with a variable mass, and a charged particle in a magnetic field

Association between periodontitis and systemic medication intake: A case- control study

BackgroundTo investigate the frequency of systemic drugs taken by elderly patients with or without periodontitis and the possible association between medication consumption and the severity of periodontitis.MethodsA total of 1221 patients, including 608 with generalized moderate to severe periodontitis (periodontitis group) and 613 age- and gender- matched individuals with healthy periodontium (healthy group) were selected. Systemic conditions, medications and periodontal status were recorded. Medication intake frequency (%) was compared using unconditional logistic regression.ResultsThe top three most common medications were angiotensin- converting enzyme (ACE) inhibitors (17.9%), antidepressants (17.8%), and lipid- lowering medications (16.5%). Both ACE inhibitors and antidepressants showed statistically higher intake frequency in the periodontitis group relative to healthy controls (21.5% versus 14.4%; odds ratio [OR] = 1.64), (21.1% versus 14.5%, OR = 1.57) (P < 0.01). Additionally, intake of oral hypoglycemic agents, calcium channel blockers (CCB), insulin, and diuretics were significantly higher in the periodontitis group with OR = 2.49, 2.32, 2.08 and 1.79, respectively (P < 0.05). Several medications demonstrated a disease severity- dependent association comparing generalized severe periodontitis with moderate periodontitis and healthy group: oral hypoglycemic agents (17.4% versus 16.8% versus 8.0%), CCB (14.8% versus 14.4% versus 8.0%) and anticonvulsants (13.4% versus 7.7% versus 6.4%) with OR of 2.43, 1.99, and 2.28 (severe periodontitis versus healthy group), respectively.ConclusionThere was a significantly higher frequency of medication intake related to cardiovascular disease and diabetes in patients with periodontitis. A disease severity- dependence with medication intake frequency was also noted. This study provides indirect evidence for the possible relationship between systemic diseases and periodontitis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163409/2/jper10532_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163409/1/jper10532.pd

Basics of Bose-Einstein Condensation

The review is devoted to the elucidation of the basic problems arising in the theoretical investigation of systems with Bose-Einstein condensate. Understanding these challenging problems is necessary for the correct description of Bose-condensed systems. The principal problems considered in the review are as follows: (i) What is the relation between Bose-Einstein condensation and global gauge symmetry breaking? (ii) How to resolve the Hohenberg-Martin dilemma of conserving versus gapless theories? (iii) How to describe Bose-condensed systems in strong spatially random potentials? (iv) Whether thermodynamically anomalous fluctuations in Bose systems are admissible? (v) How to create nonground-state condensates? Detailed answers to these questions are given in the review. As examples of nonequilibrium condensates, three cases are described: coherent modes, turbulent superfluids, and heterophase fluids.Comment: Review articl

Scattering Properties of Argon Gas in the Temperature Range 87.3-120 K

A theoretical model, based on the Galitskii-Migdal-Feynman formalism, is introduced for determining the scattering properties of argon gas, especially the "effective" total, viscosity and average cross-sections. The effective phase shifts are used to compute the quantum second virial coefficient in the temperature range 87.3-120 K. The sole input is the Hartree-Fock dispersion (HFD-B3) potential. The thermophysical properties of the gas are then calculated. The results are in good agreement with experimental data

Scattering properties of argon gas in the temperature range 87.3-120 K

A theoretical model, based on the Galitskii-Migdal-Feynman formalism, is introduced for determining the scattering properties of argon gas, especially the "effective" total, viscosity and average cross-sections. The effective phase shifts are used to compute the quantum second virial coefficient in the temperature range 87.3-120 K. The sole input is the Hartree-Fock dispersion (HFD-B3) potential. The thermophysical properties of the gas are then calculated. The results are in good agreement with experimental data