Modified electron acoustic field and energy applied to observation data هشام جمعه محمد عبدالواحد
Improved electrostatic acoustic field and energy have been debated in vortex trapped hot electrons and fluid of cold electrons with pressure term plasmas. The perturbed higher-order modified- Korteweg-de Vries equation (PhomKdV) has been worked out. The effect of trapping and electron temperatures on the electro-field and energy properties in auroral plasmas has been inspected.
On Time-Fractional Cylindrical Nonlinear Equation هشام جمعه محمد عبدالواحد
Properties of cylindrical electron acoustic solitons are studied in vortex plasmas. The modified cylindrical Korteweg–de Vries (KdV) equation is acquired and converted into the time fractional cylindrical modified KdV equation by Agrawal’s analysis. Via the Adomian decomposition method, a cylindrical soliton solution to the equation is obtained. The cylindrical time fractional effect on the wave properties is investigated. Further, the increase of the fractional order of time ...
Higher-Order Corrections to Earth's Ionosphere Shocks هشام جمعه محمد عبدالواحد
Nonlinear shock wave structures in unmagnetized collisionless viscous plasmas composed fluid of positive (negative) ions and nonthermally electron distribution are examined. For ion shock formation, a reductive perturbation technique applied to derive Burgers equation for lowest-order potential. As the shock amplitude decreasing or enlarging, its steepness and velocity deviate from Burger equation. Burgers type equation with higher order dissipation must be obtained to avoid this deviation. Solution for the compined two equations has been derived using renormalization analysis. Effects of higher-order, positive- negative mass ratio Q, electron nonthermal parameter δ and kinematic viscosities coefficient of positive (negative) ions η1 and η2 on the electrostatic shocks in Earth’s ionosphere are also argued.
On the ion acoustic obliquely propagation in magnetized inhomogeneous plasmas هشام جمعه محمد عبدالواحد
Inhomogeneous multi-component magnetized plasmas containing inertial ions, nonthermal electrons, and Boltzmannian positrons have been investigated theoretically. Variable coefficients Zakharov Kuznetsov (VZK) equation has been derived in a small amplitude limit. It is found that the propagation directions, positron parameters and magnetic field affected the properties of propagation of positive-negative solitary waves.
A new approach for the evaluation of the effective electrode spacing in spherical ion chambers محمد عبد الرحمن شقير
Ahmed M.Maghraby , MohammedShqair, A new approach for the evaluation of th eeffective electrode spacing in spherical ion chambers. Nuclear Instruments and Methods in Physics Research A 834(2016)10–15
معاملات تكافؤ الموثوقية لنظام توالى من المركبات الغير متماثلة ذات خليط من معدلات الإخفاق محمد السيد الداوودى
A. Mustafa, B. S. El-Desouky and M. El-Dawoody, Reliability Equivalence Factors of Non identical Components Series System with Mixture Failure Rates. International Journal of Reliability and Applications, 2009 AD.
A. Mustafa, B. S. El-Desouky and M. El-Dawoody, Reliability Equivalence Factor of Series System with Mixture Failure Rates, The 42th Annual Conference ISSR Cairo University, Egypt, 2-5 Dec., 2007 AD.
Plasma Enhanced Polymer for Biocompatible and other Industrial Applications عصام محمد عبدالفتاح ابراهيم
The intent of the project is to develop a new functional materials based on plasma modification of polymer surface to use in several emerging novel application as a biocompatible material and/or improves the adhesion and wetability properties of polymer surface for other industrial applications. The conditions of the plasma treatment, such as discharge voltage (power), exposure time, gas type/composition and chamber pressure that determine the nature and degree of the chemical modification of the polymer surface must be adjusted on the polymer type to minimize degradation and aging effects. Various types of polymer that have potential use as biomedical compatible material, tissue engineering. The biomedical studies will focus on the characterization of the blood coagulation and protein adhesion on the surface of treated polymer.
publications عصام رشدى الزهار
The Published Papers د/ أشرف السيد يحيى
Crystal structure of tert-butyl 2-phenylethylcarbamat, محمد بطاح الشمري
tert-Butyl 2-phenylethylcarbamate was synthesized from the reaction of 2-phenylethylamine with 1.2 equivalents of ditert-
butyl dicarbonate in the presence of 1.5 equivalents of triethylamine in dichloromethane at 0 °C for 15 minutes and then under reux for 1 h. The crude product was puried by crystallization from hexane to give the title compound(90%) as colourless crystals, mp 56–57 °C (lit. 56.1–56.4 °C ; 54–55 °C ; 55–56 °C ).