Experimental investigation has been carried out to study the effect og gamma ray radiations on silicon solar cells. The measured experimental data are compared with the theoretical results obtained by computer simulation programs before and after radiation. P-N junction silicon cell samples were used for the study showing degradation behavior for the output power and the short circuit current with less effect on the open circuit voltage as the radiation doses increases. Enhanced series resistance was added to the solar cell model due to deformation of I –V characteristics resulting from gamma ray radiations. Wide spread spectrum of doses were employed to study the effect of the radiation on the crystal deformation and damages on different parameters of solar cells. Study reveals an improvement in the output power and short circuit current due to post annealing effect of gamma ray radiations. The conclusion consist of suggestions to protect the solar cells in space satellites.
W. ABUGHRES, M. EL-MURADI, H. EL-FITOURI(9-1992)

Abstract The increased amount of electromagnetic radiation in the environment has increased the common concern over the possible health risks of wireless devices (e.g. mobile phone ). However, to minimize the amount of energy absorbed by the user is an advantageous from the technical point of view, as well. The reduction of power absorbed by the user not only reduces any possible health hazards but also makes the antenna more efficient. In this master’s thesis, interaction between modern mobile phone antennas and user is studied by using numerical full-wave EM methods. The thesis aims at improving, understanding how mobile terminal antennas behave in the vicinity of the user and how different numerical EM methods can be used to solve the interaction problem. The results give valuable information for antenna designers in order to design antennas which have low interaction with the user as possible. Furthermore this master’s thesis introduces a simple optimization technique to enhance the performance of planar inverted F antenna (PIFA) one of common modern mobile phone antenna in vicinity of user and reduce its effect on health.
محمد على المنصورى (2008)

AbstractThis paper examines the process of sending an image over wireless mobile Channels with errors while maintaining bandwidth, transmission speed and image quality. With the tremendous development in networks, new wireless channels have been opened that threaten the security of data transmitted through networks and communication channels, and from this emerged Encryption techniques to increase the security of the transmitted data, and since the digital image compression algorithm is a process to reassemble the parts of the image so that it takes less space, but this increases the impact of the error extension in sending compressed digital images and greatly reduces the quality of the received image. This prompts us in this paper to study the performance of HQAM technology for the purpose of transmitting image data over wireless communication channels containing errors. In this paper, image quality performance has been evaluated by the BER, SNR, PSNR, SSIM, and Correlation evaluation criteria. The simulated results show that there is an improvement in the image quality received using the proposed technique.
wael saleh mohamed abughres, , , Ashrf Alzrouk Almagdob1, Ahmed B. Abdurrhman, Ibrahim A.Nasir, (9-2020)