Mode Gammas and Thermal Expansion of CaF₂

Abstract

on the occasion of his 75th birthdayThe perturbation approach of Achar and Barsch is employed to work out the mode gammas and the thermal expansion of CaF,. A shell model similar to that of Axe is employed. The pressure dependent dynamical matrix components are computed using the available data on the pressure derivatives of the elastic constants and the mode gammas of the long wavelength optical phonons. The modified moments of the phonon density of states are also computed. These results agree fairly well with the experimental values reported by Baily and Yates and the previously reported work of Ruppin.Das Storungsverfahren von Achar und Barsch wird benutzt, um die Modengamma und die thermische Ausdehnung in CaF2 zu betrachten. Verwendet wird ein Schalenmodell Lhnlicher Art, wie das von Axe. Die druckabhangigen dynamischen Matrixkomponenten werden mit erreichbaren Werten der Druckableitungen der elastischen Konstanten und den Modengamma der langwelligen optischen Phononen berechnet. Die modifizierten Momente der Phononenzustandsdichte werden ebenfalls berechnet. Diese Ergebnisse stimmen ziemlich gut mit experimentellen Werten iiberein, die von Baily und Yates und kiirzlich von Ruppin berechnet wurden.

Characterization of Cephalotyre (Ras) Cheese Supplemented with Turmeric Powder

“…Turmeric is an essential spice all over the world with a distinguished human use particularly among the Eastern people (Ravindran et al,2007).Apart from this using as spice, it is used as traditional medicine in Asian countries such as India, Bangladesh and Pakistan because of its beneficial properties ) Chattopadhyay et al,2004). It is called turmeric (Kurkom in Egypt while Zarchooveh in Iran) and has been in continuous use for its flavoring, and medicinal properties ) Govindarajan, 1980). The coloring principle of turmeric is called curcumin, which has yellow color and is the essential component of this plant ) Ammon et al,1992).…”