Mohamed Zaki

We suggest ternary structures of dielectric–metal–dielectric photonic structures to be used as
optical band pass filters. We theoretically study and evaluate the optical properties of these
one-dimensional structures. ZnSe/metal/LiF and SiC/metal/SiO2 with three metals, namely
silver, gold and copper, are suggested as the optical filters. We calculated the reflectance and the
transmittance of electromagnetic waves (EMW) out of these structures using the transfer matrix
method. These calculations take place for the case of normal and oblique incidences using
actual measured values for the indices of refraction. Our calculations show that such photonic
crystal (PC) filters have a well shaped pass band in the visible range and block efficiently
ultraviolet and infrared EMW. Our results show that PCs having silver as the metal layer are
preferred to those having gold and copper because of the high transmittance in the visible range.
A SiC/Ag/SiO2 filter shows better performance than a ZnSe/Ag/LiF one from the transmittance
and the shape of the band points of view. Such a filter shows a well shaped wide band over the
range of incident angles from 0◦ to 80◦.

Background and purpose: Down Syndrome (DS) is one of genetic disorders characterized by some common clinical and functional features. Most children with Down syndrome have deficits in balance, co-ordination, and gait throughout childhood and adulthood. So, it is essential to seek an ideal physical therapy program to help in solving such widespread problem. The purpose of this study was to examine the effects of twelve- week Gravity Force Stimulation (GFS) program on balance and gait in children with Down syndrome. Subjects: Thirty children with DS from both sexes, ranging in age from eight to ten years represented the sample of this study. They were divided randomly into two groups of equal number A (control) and B (study). Procedures: Evaluation before and after three months of treatment for each child of the two groups was conducted via using Biodex stability system to evaluate balance and using foot print method to evaluate selected gait variables (stride length and step width). Group A received a selected exercise program, while group B received GFS program training in addition to the same exercise program given to group A. Results: The results revealed no significant differences in all the measured variables when comparing the pre-treatment results of the two groups, while significant improvement was observed in the two groups when comparing their pre and post-treatment mean values. Significant difference was also observed when comparing the post-treatment results of the two groups in favor of group B. Discussion and Conclusion: Gravity Force Stimulation program utilization provides sensory feedback and may be used as a therapeutic intervention for improving balance and gait in children with DS. Key words: Down Syndrome, Gravity Force Stimulation, Balance, Gait Parameters.

The present study was designed to investigate different parasitological parameters in response to injection of purified secretory - excretory products (SEP) of S. haematobium eggs into hamsters prior to infection with cercariae as an experimental trial for decreasing or modulating severe morbidity

An analysis of the molecular dynamics of ethanol solvated by water molecules in the absence and presence of a Pt surface has been performed using DL_POLY_2.19 code. The structure and diffusion properties of an ethanol–water system have been studied at various temperatures from 250 to 600 K. We have measured the self-diffu- sion coefficients of the 50:50% ethanol-water solution; in the absence of a Pt surface our re-sults show an excellent agreement—within an error of 7.4%—with the experimental data. An increase in the self-diffusion coefficients with the inclusion of a Pt surface has been observed. The estimation of the diffusion coefficients of both water and ethanol in the presence of a Pt surface shows that they obey the Arrhenius equation; the calculated activation energies of diffusion of ethanol and water are 2.47 and 2.98 Kcal/mole, respectively. The radial distribution function graphs and density profiles have been built; their correlations with the self-diffusion coefficients of both ethanol and water mole-cules are also illustrated.