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Azzaz S.A.,Zagazig University | Blasy M.,Zagazig University | Moharem A.,Nuclear Materials Authority of Egypt | Amer O.,Zagazig University
Arabian Journal of Geosciences | Year: 2015

The Dokhan volcanics outcropping around G. Esh granite form a moderate relief and covers an area of about 40 km2. They are thermally metamorphosed along their contact with the pink granite (Y.G) giving cordierite and sillimanite hornfelses. Two groups are identified; the oldest is basic and predominate at the east of the map area, while the youngest one is mainly intermediate to acidic. The basic rocks are composed of basalt, basaltic andesite, and andesite. They exhibit trachytic, porphyritic, and amygdaloidal textures. Tuffacious varieties are present. The acidic rocks comprise dacitic andesite, porphyritic dacite, rhyodacite, and their equivalent tuffs and ignimbrites. The tuffs are laminated and thinly bedded forming thick belts. The phenocrysts are mainly of quartz, orthoclase, sanidine, and plagioclase and rarely pyroxene. Magnetite is common in the basic varieties while hematite predominates in the acidic rocks. The basic group is low-K tholeiitic to calc-alkaline nature while the acidic one is calc-alkaline and medium-K nature. The two groups have Zr/Y ratios more or less constant suggesting the same magma source. They are higher in Pb, Zn, Ba, Rb, and Sr than island-arc volcanic rocks and lower in K and Nb. The study rocks are more or less comparable to SVZ of Andes (thin continental crust). The relations of K2O and Nb abundances with the crustal thickness are discussed. © 2014, Saudi Society for Geosciences. Source

Al Alfy I.M.,Nuclear Materials Authority of Egypt
Applied Radiation and Isotopes | Year: 2013

A set of ten radioactive well-logging calibration pads were constructed in one of the premises of the Nuclear Materials Authority (NMA), Egypt, at 6th October city. These pads were built for calibrating geophysical well-logging instruments. This calibration facility was conducted through technical assistance and practical support of the International Atomic Energy Agency (IAEA) and (ARCN). There are five uranium pads with three different uranium concentrations and borehole diameters. The other five calibration pads include one from each of the following: blank, potassium, thorium, multi layers and mixed. More than 22 t of various selected Egyptian raw materials were gathered for pad construction from different locations in Egypt.Pad's site and the surrounding area were spectrometrically surveyed before excavation for the construction process of pad-basin floor. They yielded negligible radiation values which are very near to the detected general background. After pad's construction, spectrometric measurements were carried out again in the same locations when the exposed bore holes of the pads were closed. No radioactivity leakage was noticed from the pads. Meanwhile, dose rate values were found to range from 0.12 to 1.26. mS/y. They were measured during the opening of bore holes of the pads. These values depend mainly upon the type and concentration of the pads as well as their borehole diameters. The results of radiospectrometric survey illustrate that the specification of top layers of the pads were constructed according to international standards. © 2013 Elsevier Ltd. Source

Mohrez W.A.,Nuclear Materials Authority of Egypt | Mohrez W.A.,Muroran Institute of Technology | Kohyama A.,Muroran Institute of Technology | Kishimoto H.,Muroran Institute of Technology | Kohno Y.,Muroran Institute of Technology
Fusion Engineering and Design | Year: 2013

W-SiC/SiC dual layer tile has many advantages as a high heat flux component (HHFC) material for fusion, in theory. However, due to insufficient data known, its high potentiality and near term availability has not been well recognized. This work provides the recent materials R&D status and the first plasma exposure test result from the world largest helical device, large helical device of National Institute for Fusion Science in Japan. Tungsten armor with SiC/SiC substrate layer survived during the LHD plasma exposure with 10 MW/m2 maximum heat load for the 5.3-s operation cycle. The macro and microstructure evolution, including crack and pore formation, was analyzed and an excellent high heat load resistance was demonstrated. © 2013 Elsevier B.V. Source

Zoheir B.A.,Benha University | Abdel-Fattah M.G.,Nuclear Materials Authority of Egypt | ElAlfy S.M.,Nuclear Materials Authority of Egypt
Arabian Journal of Geosciences | Year: 2013

Orogenic, lode gold mineralisation in the South Eastern Desert of Egypt is related to quartz veins spatially and temporally associated with conjugate NW- and NE-trending brittle-ductile shear zones. These structures are assumed to be linked to a regional transpression deformation which occurred late in the tectonic evolution of the area. In the Betam deposit, gold is confined to quartz(±carbonate) veins cutting through tectonised metagabbro and metasedimentary rocks in the vicinity of small granite intrusions. The ore bodies contain ubiquitous pyrite and arsenopyrite, in addition to minor disseminated chalcopyrite, pyrrhotite, galena, tetrahedrite and rare gold/electrum. New ore microscopy and electron microprobe studies indicate that most free-milling Au is intimately associated with the late-paragenetic galena-tetrahedrite-chalcopyrite assemblage. An early Fe-As sulphide assemblage, however, shows minor traces of refractory gold. New mineralogical and geochemical data are used to better constrain on possible element dispersions for exploration uses. This study indicates that parameters that most consistently define primary dispersion of gold in the mine area include pervasive silicification, sericite and carbonate alteration. The trace element data of gold lodes reflect a systematic dispersion of gold and certain base metals. Low-cost, extensive exploration programs may use elevated concentrations of Ag, Sb, Cu and Pb as tracers for Au ore zones in the Betam mine area and surroundings. © 2012 Saudi Society for Geosciences. Source

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