Aggregates grain size and press rate dependence of the shielding parameters for some concretes

This study points to evaluate the effect of crushed basalt grain size and the press rate on gamma ray shielding properties for some concretes. Nine different concretes were made up of 75% basalt, 25% Portland cement and drops of sodium meta silicate. Three concretes were performed with an average grain size varied between 25 and 107 μm. The other six concretes were performed under different press rate varied between 1.01 and 142.76 kg/cm2 using a hydraulic press. The mass attenuation coefficient (μm) of the prepared concretes was measured using the narrow beam transmission method using a hyper pure germanium detector at gamma ray energies 661.6, 1173.2, 1332.5, 121.8, 244.7, 344.3, 778.9, 964, 1112, 1408 KeV emitted by point sources 137Cs, 60Co and 152Eu. Other important shielding parameters such as half value thickness and radiation protection efficiency were calculated for the prepared concretes at different energies. The obtained experimental data was compared with theoretical data obtained from XCOM program. The results showed that the mass attenuation coefficient was decreased with energy increase, but it increases with grain size decrease. The obtained results showed also that the mass attenuation enhanced by increasing the pressure rate. © 2019 Elsevier Lt

Uranium/Vanadium Separation from El-Sahu Carnotite-Bearing Kaolin, Southwestern Sinai, Egypt

A working sample of the lower Carboniferous carnotite-bearing kaolin of wadi El Sahu, Southwestern, Sinai assaying 2.6% uranium and 1.2% vanadium species is subjected to sulfuric acid pug leaching. The extraction behavior of both metal values was first studied from their combined synthetic solution using DEHPA and Aliquat-336 extractants. The obtained results are then applied upon El-Sahu sulfuric acid leach liquor where after proper oxidation of the leach liquor, uranium was selectively extracted as cationic ions by DEHPA solvent, while the vanadium left behind was subsequently extracted as anionic ions using Aliquat-336

An Extended Investigation of High-Level Natural Radioactivity and Geochemistry of Neoproterozoic Dokhan Volcanics: A Case Study of Wadi Gebeiy, Southwestern Sinai, Egypt

High-level natural radioactivity, geochemical, geological, and radiological hazard assessment of the poorly investigated Wadi Gebeiy Dokhan volcanics rocks are discussed. Wadi Gebeiy Dokhan volcanics are located in Southwestern Sinai, Egypt, covering an area of ~1.3 km2. Dokhan volcanics rocks are represented by porphyritic dacite. Geochemically, they have medium-k characters and originate from calc-alkaline magma within a volcanics arc environment. Along the fault plane striking NNE-SSW, and at its intersection with the NW-SE fault plane, altered Dokhan volcanics occur with high radioactive anomalies. Radiological parameters (absorbed dose rate, radium equivalent, activity annual effective dose, external and internal hazard indices) are used to evaluate their suitability as an ornamental stone. Except for the absorbed dose rate, all the radiological hazard indices show that unaltered Dokhan volcanics can be used as an ornamental stone. Controversially, the applied radiological indices reveal that altered Dokhan volcanics have a higher content than the recommended values of UNSCEAR, reflecting their risk on human organs. © 2022 by the authors.H.M.H.Z. is funded by a scholarship under the Joint Executive Program between Egypt and Russia

DETERMINATION OF GAMMA RAY ATTENUATION COEFFICIENT OF DIFFERENT TYPES OF BASALTIC ROCKS

Linear and mass attenuation coefficients were studied for basaltic samples from Sinai, Egypt using gamma ray sources 137Cs, 60Co with energies 662, 1173 and 1332 keV.Приведения результаты исследований линейных и массовых коэффициентов ослабления .-излучения 137Cs и 60Co образцами базальта Юго-Западного Синая (Египет) при энергиях 662, 1173 и 1332 кэВ