Investigations on finite ideal quantum gases

Recursion formulae of the N-particle partition function, the occupation numbers and its fluctuations are given using the single-particle partition function. Exact results are presented for fermions and bosons in a common one-dimensional harmonic oscillator potential, for the three-dimensional harmonic oscillator approximations are tested. Applications to excited nuclei and Bose-Einstein condensation are discussed.Comment: 13 pages, 7 postscript figures, uses 'epsfig.sty'. Submitted to Physica A. More information available at http://obelix.physik.uni-osnabrueck.de/~schnack

Textbook approval systems and the Program for International Assessment (PISA) results: A preliminary analysis

This paper examines the textbook approval systems of various countries in relation to educational outcomes. This investigation is based on research in the Netherlands that aimed to gain an overview of textbook approval systems in use across the world.The study also looked at the Program for International Assessment PISA results, in order to determine which countries have high and low PISA results. The researchers also sought to determine whether there was a relationship between state influence, as reflected and formalised in textbook approval systems, and student achievement educational outcomes.It is hoped this investigation will be a starting point for ongoing discussion about the usefulness of comparing textbook approval systems, and the possible relationships between national approval systems and educational outcomes

Thermodynamic fermion-boson symmetry in harmonic oscillator potentials

A remarkable thermodynamic fermion-boson symmetry is found for the canonical ensemble of ideal quantum gases in harmonic oscillator potentials of odd dimensions. The bosonic partition function is related to the fermionic one extended to negative temperatures, and vice versa.Comment: 7 pages, no figures, submitted to PHYSICA A. More information available at http://www.physik.uni-osnabrueck.de/makrosysteme

Come Ma Honey Come

https://digitalcommons.library.umaine.edu/mmb-vp/1239/thumbnail.jp

Quantized Roentgen Effect in Bose-Einstein Condensates

A classical dielectric moving in a charged capacitor can create a magnetic field (Roentgen effect). A quantum dielectric, however, will not produce a magnetization, except at vortices. The magnetic field outside the quantum dielectric appears as the field of quantized monopoles

Graphs and principal ideals of finite commutative rings

In \cite{ABM}, Afkhami and Khashyarmanesh introduced the cozero-divisor graph of a ring, $\Gamma\u27(R)$, which examines relationships between principal ideals. We continue investigating the algebraic implications of the graph by developing the reduced cozero-divisor graph, which is a simpler analog

The effect of various dietary factores on the serum- cholesterol level

No Abstract

Properties of nanostructured diamond-silicon carbide composites sintered by high pressure infiltration technique

A high-pressure silicon infiltration technique was applied to sinter diamond–SiC composites with different diamond crystal sizes. Composite samples were sintered at pressure 8 GPa and temperature 2170 K. The structure of composites was studied by evaluating x-ray diffraction peak profiles using Fourier coefficients of ab initio theoretical size and strain profiles. The composite samples have pronounced nanocrystalline structure: the volume-weighted mean crystallite size is 41–106 nm for the diamond phase and 17–37 nm for the SiC phase. The decrease of diamond crystal size leads to increased dislocation density in the diamond phase, lowers average crystallite sizes in both phases, decreases composite hardness, and improves fracture toughness