Time filter

Source Type

Gomaa R.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Adly I.,The British University in Egypt | Sharshar K.,National Center for Radiation Research And Technology | Safwat A.,Cairo University | Ragai H.,Ain Shams University
IEEE Radiation Effects Data Workshop | Year: 2014

WSN deployment for monitoring nuclear environment has recently addressed as incremental and experimental networks. The work objective is to determine dose tolerance of commercially wireless Zigbee modules in nuclear embedded applications, with gamma irradiation fluxes. © 2014 IEEE. Source

Akl Z.F.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | El-Saeed S.M.,Egyptian Petroleum Research Institute | Atta A.M.,Egyptian Petroleum Research Institute | Atta A.M.,King Saud University
Journal of Industrial and Engineering Chemistry | Year: 2016

A new in-situ magnetite nanoparticles inserted into crosslinked poly (acrylamido-amineamidoxime-co-2-acrylamido-2-methylpropane sulfonic acid (AO/AMPS) were prepared and used as novel uranium adsorbents. The prepared composites were applied as adsorbents to remove U(VI) from aqueous solutions that could be separated by a simple magnetic separation method. The removal of U(VI) was evaluated by spectrophotometric method using arsenazo-III as complexing agent. The results showed that, the sorption process strongly depended on pH and the sorption equilibrium can be reached within 150 min. The Langmuir sorption isotherm model correlated well with the uranium sorption equilibrium data for the concentration range of 50-500 mg/L. © 2015 The Korean Society of Industrial and Engineering Chemistry. Source

Atta A.M.,King Saud University | Atta A.M.,Egyptian Petroleum Research Institute | Akl Z.F.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA
Materials Chemistry and Physics | Year: 2015

The present study describes synthesis and characterization of diacrylamidoxime triaethylenetetralevopimaramide (DPAO) and its use in surface modification of Fe3O4 magnetic nanoparticles to obtain DPAO-based magnetic nanoparticles (DPAO-MNPs). The prepared composite was characterized by FTIR, 1HNMR, XRD, DLS, TEM, SEM and EDX. Vibrating sample magnetometer is used to determine the magnetic properties of DPAO-MNPs. Results of analyses indicate that the surface of Fe3O4 was successfully capped with DPAO. The adsorption features of the prepared composite towards thorium ions were investigated in a batch system. Kinetic study of Th(IV) adsorption on DPAO-MNPs indicate the adsorption equilibrium achieved within 150 min and is pH dependent. The adsorption results were described mathematically using Langmuir and Freundlich sorption models. The composite showed a maximum Th(IV) loading capacity of 666 mg/g at 25 °C and pH 4. The thermodynamic results indicated that the adsorption process was thermodynamically favorable, spontaneous and endothermic nature. The obtained results suggest that DPAO-MNPs composite may be considered as a potential fast, effective and simple adsorbent for sorption thorium(IV) from water. © 2015 Elsevier B.V. All rights reserved. Source

Abdeen Z.,Egyptian Petroleum Research Institute | Akl Z.F.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA
RSC Advances | Year: 2015

Poly(vinyl alcohol)/multiwalled carbon nanotubes (PVA/MWCNTs) composite hydrogels were prepared by a dispersion method and their ability to adsorb and remove uranyl ions from aqueous solutions was investigated. The prepared composites were characterized by XRD, TEM, SEM and FTIR. The effect of contact time, solution pH, initial UO22+ ion concentration and temperature on UO22+ ion adsorption from aqueous solution onto the prepared hydrogels was studied. The obtained results illustrated that, dispersion of MWCNTs into the PVA matrix enhanced the removal efficiency of UO22+ ions compared to PVA only. The Langmuir and Freundlich adsorption models have been applied to evaluate the adsorption efficiency and the data correlated well with the Langmuir model. Thermodynamic parameters (ΔH°, ΔS°, ΔG°) were determined which indicated that the UO22+ ion adsorption process onto the prepared hydrogels was exothermic and spontaneous. The adsorbed UO22+ can be desorbed effectively by 0.1 M EDTA. © The Royal Society of Chemistry 2015. Source

Shaban S.E.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Ibrahiem N.M.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | El-Mongy S.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Elshereafy E.E.,Menoufia University
Journal of Radioanalytical and Nuclear Chemistry | Year: 2013

Ten ore samples, two unpurified yellow cake samples and natural uranyl nitrate hexahydrate sample were analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) method to verify source nuclear material. Samples represent source nuclear material as possible. All samples were scanned at ideal conditions; working distance = 10 mm, voltage = 30 kV, magnification value = × 100, spot size = 50 to screen samples for the presence of uranium and thorium, Also Hyper pure germanium (HPGe) gamma spectrometers were applied to estimate the uranium and thorium contents in Bq/kg (ppm). For the ore samples uranium-238 ranges from 1,049.23 Bq/kg (85.30 ppm) to 2,096.06 Bq/kg (170.41 ppm), uranium-235 ranges from 47.51 to 105.61 Bq/kg and thorium-232 ranges from 22.84 Bq/kg (5.65 ppm) to 41.78 Bq/kg (10.34 ppm). For the yellow cake samples and uranyl nitrate hexahydrate uranium-238 ranges from 42.99 Bq/kg (3.50 ppm) to 71,887.2 Bq/kg (5,844.49 ppm) and thorium-232 is 4.78 Bq/kg (1.83 ppm) and the other two samples are lower than the detection limit. © 2012 Akadémiai Kiadó, Budapest, Hungary. Source

Discover hidden collaborations