Dr. Zain M. Al-Amoudi, Doctor of Philosophy in Science, (Experimental Physics) from King Abdulaziz University (KAU), Faculty of Science, Physics Department, Associate Professor. She has Head of physics department 4 years. She has published more than 15 papers in reputed journals, She has attended and participated in many National and International conferences.
In this study, the natural radio activities of 40K, 226Ra,and 232Th and the man- made of 137Cs in samples of solid wastes of (TIG) welding process, collected from the welding workshops in different locations of Saudi Arabia (Jeddah, Asfan and Tabuk). The concentrations of 226Ra, 232Th, 40K and 137Cs were determined by gamma-ray spectrometer using HPGe detector. The results show that the average concentrations were 44.8, 50.23, 431.82 and 1.5 Bq /Kg, respectively. Radium equivalent activities of the samples under consideration were calculated with an average value of 127 Bq/Kg .The total absorbed dose in the study samples ranged between the lower value (0.027) mGy/h (sample No.4) to the higher value (0.628) mGy/h (sample No.5), with an average value of (0.19) mGy/h which is lower than the limits as recommended by (UNSCEAR 2000). Also, heavy metals analyses were done by atomic absorption spectrophotometer. The concentration’s average values of Ca, Fe, K, Mg, Bi, Pb and Th elements in the samples of welding workshops waste were 1.02%, 63.18%, 0.25%, 0.25%, 76.99 ppm, 62.87 ppm and 17.63 ppm respectively.
The data were discussed and compared with limits given by United Nations Scientific Committee for the effects of Atomic Radiation (UNSCEAR).
Cr2O3 nanoparticles were synthesized by biological method using neem plant extract. The synthesized nanoparticles are characterized by SEM, UV-Vis, FT-IR and XRD methods. The size of the nanoparticles were shown to be 35.5nm. This synthesized Cr2O3 nanoparticles were embedded in PVA polymert. The strustural, electrical and optical properties of nanocomposite films were studied experimentally. The effect of concentration of PVA on PVA films and concentration of Cr2O3 nanoparticles were studied. The structural properties are studied using X-ray diffraction, SEM and FT-IR spectra. Optical property is studied using UV-Vis spectroscopy. Results showed number of Braggs planes in the structure of polymer and its crystallinity are increased notiecbly. The ℷ max of Cr2O3 nanoparticles undergoes a blue shift toward the lower wavelength after embedding. Scanning electron microscopy shows that the prepared Cr2O3 nanoparticles were despersed and nearly uniform in diameter within the polymeric matrix. Frequency dependent conductivity, photo-voltaic activity and viscosity measurements of PVA and PVA/Cr2O3 nanocomposites films/ solutions are also compared. The induced structural changes are revealed through XRD and FT-IR spectroscopy. The synthesized Cr2O3 nanoparticles showed very good biological activity and acts as a catalyst for KMnO4 decomposition with the evolution of O2, which plays an important role in renewable source of energy.