Din K.S.,South Valley University
Science of the Total Environment | Year: 2011
The concentration of 210Po was determined in different foodstuffs of plant origin purchased from markets in Qena City, Upper Egypt. Measurement of 210Po has been carried out using alpha spectrometry technique in different food categories such as vegetables, fruits, cereals beverages and herbs. The general range of 210Po activity levels ranged widely from <0.010-18.6±0.910mBqg-1, with minimum being in cereal samples and maximum being in beverage samples. Tea samples recorded highest activity concentrations of 210Po with lowest value of 10±0.54 mBqg-1 for Crown tea and highest value of 18.6±0.910mBqg-1 for El maabad tea. The daily intake of 210Po from food consumption reveals that vegetables are the biggest contributors, while beverages are the lowest. The effective ingestion dose has been estimated for Qena City residents and it was found in the range 0.008-38.3μSvy-1. © 2011 Elsevier B.V.
Khalifa M.,South Valley University
European Journal of Mechanics, A/Solids | Year: 2015
Flügge's shell theory and solution for the vibration analysis of a non-homogeneous orthotropic elliptical cylindrical shell resting on a non-uniform Winkler foundation are presented. The theoretical analysis of the governing equations of the shell is formulated to overcome the mathematical difficulties of mode coupling of variable curvature and homogeneity of shell. Using the transfer matrix of the shell, the vibration equations based on the variable Winkler foundation are written in a matrix differential equation of first order in the circumferential coordinate and solved numerically. The proposed model is applied to get the vibration frequencies and the corresponding mode shapes of the symmetrical and antisymmetrical vibration modes. The sensitivity of the vibration behavior and bending deformations to the non-uniform Winkler foundation moduli, homogeneity variation, elliptical and orthotropy of the shell is studied for different type-modes of vibrations. © 2014 Elsevier Masson SAS.
Rashed M.N.,South Valley University
Journal of Hazardous Materials | Year: 2010
This study includes tailing from gold mine, at Allaqi Wadi Aswan, Egypt, used by incident Egyptian and after by some English companies. Tailings, soils and wild plants (Acia Raddiena and Aerva Javanica) were sampled and analysed for toxic metals (Hg, Cd, Pb and As) and associated heavy metals (Cr, Ag, Ni, Au, Mo, Zn, Mn and Cu) using ICP-MS, ICP-AES, CVAAS and FAAS techniques. The present work concerns the distribution and mobility of these metals from tailing to the surrounding soils and wild flora. The results reveal that Cr, Cu, Zn, Ni, Ag, Au, Mn, Hg, As, Ag, Au and Pb in soil decreased as faraway from the tailing, after then irregular trends as a result of input from surrounding rocks. Acia Raddiena plant accumulated As, Cd and Pb in higher levels than Aerva Javanica. Quantification of soil and plant pollution was studied using enrichment factors, contamination factor, pollution index and bioaccumulation factors and show good interpretations of the results. The overall results of this study show that the soil and plants near the gold mine tailing were highly toxic, and the plants and soil must not be uses for grazing or agriculture. © 2010 Elsevier B.V.
Mahdy A.,South Valley University
Nuclear Engineering and Design | Year: 2012
The term of nanofluid refers to a solid-liquid mixture with a continuous phase which is a nanometer sized nanoparticle dispersed in conventional base fluids. A numerical analysis has been presented to investigate the unsteady mixed convection boundary layer flow and heat transfer due to uncertainties of thermal conductivity and dynamic viscosity of nanofluid over a stretching vertical surface. The unsteadiness in the flow and temperature fields is caused by the time-dependent of the stretching velocity and the surface temperature. The governing partial differential equations with the auxiliary conditions are converted to ordinary differential equations with the appropriate corresponding conditions via scaling transformations. Different water-based nanofluids containing Cu, Ag, CuO, Al 2O 3, and TiO 2 are taken into consideration. The effects of pertinent parameters such as the solid volume fraction of nanoparticles, Prandtl number, mixed convection parameter, and the unsteadiness parameter have been discussed. Furthermore, different models of nanofluid based on different formulas for thermal conductivity and dynamic viscosity on the flow and heat transfer characteristics is discussed. Comparison with known results for steady state flow is presented and it found to be in excellent agreement. © 2012 Elsevier B.V.
Awadalla E.A.,South Valley University
Experimental and Toxicologic Pathology | Year: 2012
Paraquat has been demonstrated to be a highly toxic compound for humans and animals and many cases of acute poisoning and death have been reported over the past few decades. The current experiment aimed to examine if vitamin C (ascorbic acid) alleviates the morphological changes induced by paraquat (PQ) administration in the liver and kidney of male albino rats. Male adult rats received paraquat (PQ) (1.5. mg/kg body weight) daily for three weeks. Vitamin C (VC) at a dose of 20. mg/kg body weight was given concomitantly with PQ to rats. Animals were divided into three groups in this experiment (control, PQ and PQ. +. VC). The morphopathological manifestations were investigated in tissues from liver and kidney. As expected, PQ administration induced marked changes in the morphological structure of the liver and kidney in PQ demonstrated animals. Importantly, vitamin C administration restored PQ-induced changes in the studied organs. Vitamin C administration attenuated the morphological damages induced by PQ in the liver and kidney of experimental animals. Our results suggest an antitoxic effect of vitamin C against paraquat. © 2010 Elsevier GmbH.