Showing papers by "Yasser M. Moustafa published in 2004"
TL;DR: In this article, the conductivity data were analyzed in terms of Mott's model for small polaron hopping, and it was suggested that the change of density might be correlated with the change in the relative concentration of FeO4 and FeO6 units.
Abstract: IR spectroscopy, density and DC conductivity measurements have been carried out for Fe2O3–P2O5 glasses. Results indicate that the redox ratio of the Fe2+ ions decreases while the density increases with increasing Fe2O3 content. It is suggested that the change of density might be correlated with the change in the relative concentration of FeO4 and FeO6 units. Analysis of the IR spectra reveals that Fe2O3 enters the phosphate matrix in the form of Fe2+ and Fe3+ ions through the formation of P–O–Fe2+ and P–O–Fe3+ bonds at the expense of P–O–P bonds. The conductivity data were analyzed in terms of Mott's model for small polaron hopping. Variation in conductivity is correlated with structural changes that take place upon increasing the Fe2O3 content in the glasses.
63 citations
6 citations
31 Dec 2004
TL;DR: Exposure to 50 Hz, 5 mTesla magnetic field for periods of 1,2 and 4 weeks has no effect on testosterone level, some changes on FSH and LH serum levels and increase in serum prolactin level.
Abstract: The question of whether extremely low frequency magnetic fields can affect biological system, has attracted attention by many research groups for quite some time. Still today, the theoretical possibility of such an interaction is often questioned and the site of interaction is unknown. In the present study, the influence of Extremely low frequency magnetic field of 50 Hz, 5 mTesla on sex hormone status in male rats was studied. 60 male albino rats, divided into 6 groups of 10 animals each. Animal groups were continuously exposed to 50 Hz, 5 mTesla magnetic field generated by magnetic field chamber for periods of one week, two weeks and four weeks. For each experimental point, sham treated group was used as a control. Assay of serum testosterone hormone, Lutenizing Hormone(LH), Follicular stimulating hormone (FSH) and prolactin hormone were performed. Serum testosterone hormone level showed no significant changes, serum FSH showed significant increased than sham exposed group only after 1 week magnetic field exposure, serum LH showed significant increase than sham exposed group only after 4 weeks magnetic field exposure while serum prolactin hormone level showed significant increase in all magnetic field exposed groups than sham exposed animals. We conclude that exposure to 50 Hz, 5 mTesla magnetic field for periods of 1,2 and 4 weeks has no effect on testosterone level, some changes on FSH and LH serum levels and increase in serum prolactin level.
1 citations