The Countable Chain Condition for C*-Algebras

In this paper, we introduce the countable chain condition for C*-algebras and study its fundamental properties. We show independence from ZFC of the statement that this condition is preserved under the tensor products of C*-algebras.Comment: 9 page

Indirect Optical Absorption of Single Crystalline beta-FeSi2

We investigated optical absorption spectra near the fundamental absorption edge of beta-FeSi2 single crystals by transmission measurements. The phonon structure corresponding to the emission and absorption component was clearly observed in the low-temperature absorption spectra. Assuming exciton state in the indirect allowed transition, we determined a phonon energy of 0.031 +- 0.004 eV. A value of 0.814 eV was obtained for the exciton transition energy at 4K.Comment: 10 pages with 3 figure

Mechanical Characteristics of Amorphous Metals

This paper reviews new informations obtained from the latest experiments concerned with the mechanical properties of amorphous metals. The selected subjects are of static and dynamic properties, plastic deformation and toughness, and several important effects on mechanical behaviors such as compositional, structural and environmental effects. Amorphous metals are a new type material having consistently very high strengths together with a distinguished toughness and also they are classified as an elastic-perfectly plastic solid. In amorphous transition metal-metalloid alloys, the alloy system containing silicon and boron has high values of strengths and hardness, and a wide region of concentrations for becoming amorphous. An appreciable loss of ductility in some amorphous ferroalloys takes place by aging at temperatures much lower than the crystallization temperature or by hydrogen embrittlement under a corrosive condition