Al Azher University

Asyūţ, Egypt

Al Azher University

Asyūţ, Egypt
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El-Taher A.,Al Azher University | El-Taher A.,Qassium University
Applied Radiation and Isotopes | Year: 2010

Neutron activation analysis (NAA) is one of the most powerful analytical techniques for multielement determination of rocks. In the present work NAA and HPGe detector γ-spectroscopy was used to determine chromium and 15 minor and trace elements qualitatively and quantitatively from chromite rock samples collected from El-Robshi area in the Eastern Desert, Egypt. The samples were properly prepared together with their standards and simultaneously irradiated by thermal neutrons at the TRIGA Mainz research reactor. Short time irradiation (1-5min) was used to determine Mg, Ti and Mn. Long time irradiation (6h) was used to determine Na, Ga, As, La, Sc, Cr, Fe, Co, Zn, Zr, Ce, Ce, Yb, Lu, Hf and Ta. In El-Robshi chromite comprises 18 sites, more than 100 lenses of massive chromite, more than 2700 tons averaging 44% Cr 2O 3 and the average of 51Cr 40.2%. © 2010 Elsevier Ltd.


El-Taher A.,Al Azher University | El-Taher A.,Qassium University
Applied Radiation and Isotopes | Year: 2012

The instrumental neutron activation analysis technique (INAA) was used for qualitative and quantitative analysis of granite samples collected from four locations in the Aswan area in South Egypt. The samples were prepared together with their standards and simultaneously irradiated in a neutron flux of 7×10 11n/cm 2s in the TRIGA Mainz research reactor. Gamma-ray spectra from an hyper-pure germanium detector were analyzed. The present study provides the basic data of elemental concentrations of granite rocks. The following elements have been determined Na, Mg, K, Fe, Mn, Sc, Cr, Ti, Co, Zn, Ga, Rb, Zr, Nb, Sn, Ba, Cs, La, Ce, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U. The X-ray fluorescence (XRF) was used for comparison and to detect elements, which can be detected only by XRF such as F, S, Cl, Co, Cu, Mo, Ni, Pb, Se and V. The data presented here are our contribution to understanding the elemental composition of the granite rocks. Because there are no existing databases for the elemental analysis of granite, our results are a start to establishing a database for the Egyptian granite. It is hoped that the data presented here will be useful to those dealing with geochemistry, granite chemistry and related fields. © 2011 Elsevier Ltd.


El-Taher A.,Qassium University | El-Taher A.,Al Azher University | Althoyaib S.S.,Qassium University
Applied Radiation and Isotopes | Year: 2012

The present work deals with identifying and determining the activity levels of natural occuring radionuclides, 226Ra and 232Th series, their decay products and 40K, in chemical and organic fertilizers used in Kingdom of Saudi Arabia. A total of 30 samples: 20 phosphatic fertilizers (single super-phosphate SSP and triple super-phosphate,TSP) and 10 organic fertilizers (cow, sheep and chicken) collected from markets and farms. The gamma-ray spectrometer consists of NaI(Tl) detector and its electronic circuit was used for measuring γ-ray spectra. The ranges of radioactivity levels of 226Ra, 232Th and 40K in chemical fertilizers are 51.5±5.2-106.3±7.5, 5.1±1.6-9.9±3.2. and 462.6±21-607.3±14Bqkg -1, respectively. The activities of 226Ra, 232Th and 40K in natural fertilizers (cow, sheep and chicken) are lower than the activities in chemical fertilizers. The obtained data are compared with available reported data from other countries in literature. The Ra eq in chemical fertilizer ranges from 100.37 to 161.43Bqkg -1 and in organic fertilizer ranges from 34.07 to 102.19Bqkg -1, which are lower than the limit of 370Bqkg -1 adopted from NEA-OECD (1979). The average heavy metal (Pb, Cd, Ni, Co and Cr) contents of the fertilizers marketed in the Kingdom of Saudi Arabia are also determined and within the limits of those used worldwide. © 2011 Elsevier Ltd.


El-Taher A.,Al Azher University | El-Taher A.,Qassium University
Radiation Protection Dosimetry | Year: 2011

Representative environmental samples (sandy soil, limestone, marble and gravels) collected from Wadi El Assuity, protective area, Assuit governorate in Upper Egypt have been investigated radiometrically using NaI (Tl) gamma-ray spectrometer. The specific activity of the radionuclides in Bq kg-1 for soil ranged between 10.5 and 18.7 for 226Ra, 1.5 to 4.6 for 232Th and from 94 to 107 for 40 K, for limestone ranged between 19 and 27.1 for 226Ra, 32.9 to 50 for 232Th and from 49 to 7 3 for 40 K, where, for marble ranged between 12.2 and 30.7 for 226Ra, 32.6 to 59.5 for 232 Th and 55 to 70 for 40 K and for gravels ranged between 7.8 and 21.8 for 226Ra, 19.8 to 30.0 for 232Th and from 151 to 260 for 40 K. The mean activity concentrations of measured radionuclides were compared with other literature values. The absorbed dose rate, radium equivalent activity and external hazard index were calculated and compared with internationally recommended values. The gamma absorbed dose rates in the samples ranged between 8.44 and 50.89 nGy h -1 . These dose rates are consistent with the accepted worldwide average 55 nGy h -1 for the public. All values obtained for radium equivalent activity are <370 Bq kg -1 , which are acceptable for safe use. The calculated values of external hazard index obtained varied from 0.12 to 0.24. Since these values are lower than unity, one can say that the radiation hazard is insignificant for the population living in the investigated area. This permits the use of these materials sediments as building materials in any probable development projects at this area. © The Author 2010. Published by Oxford University Press. All rights reserved.


El-Taher A.,Qassim University | El-Taher A.,Al Azher University
Romanian Reports of Physics | Year: 2012

Building materials are one of the potential sources of indoor radioactivity because of the naturally occuring radionuclides in them. External as well as internal exposures are the two pathways of radiation dose imparted to the human beings from the building materials. Natural radioactivity levels of 35 samples of natural and manufactured building materials used in Qassim area, Saudi Arabia have been investigated by using gamma spectrometer with NaI(Tl) detector. The samples were collected from local market and construction sites. From the measured γ-ray spectra, activity concentrations were determined. The activity ranged from 12.7 ±3.4 to 38.4 ±4.4 Bq kg-1 for 226Ra, from 13.2±0.7 to 49.2±2.3 Bq kg-1 for 232Th and from 64±3 to 340±6.7 Bq kg-1 40K. The activities are compared with available reported data from other countries and with the world average value for soils. The radium equivalent activity Raeq, the external hazard index Hex and the absorbed dose rate in air D in each sample was evaluated to assess the radiation hazard for people living in dwelling made of materials studied. All building materials have shwon Raeq ranged from 39.64 to 122.71Bq kg-1. These values are lower than the limit of 370 Bq kg-1 adopted by OECD the Organization for Economic Cooperation and Development. The absorbed dose rate in indoor air are lower than the international recommended values of 55 n Gy h-1 for all test samples. All the materials examined are acceptable for use as building materials as defined by the OECD criterion.


El-Taher A.,Al Azher University | Madkour H.A.,National Institute of Oceanography and Fisheries of Egypt
Applied Radiation and Isotopes | Year: 2011

Forty-four marine sediment samples were collected in-front of wadis mouth along the Egyptian Red Sea coast: Wadi El-Hamra, Wadi El-Esh, Wadi Abu-Shaar, Wadi El-Gemal and Wadi Khashir (Hamata). Several investigations of natural activity and trace metals of surface sediments were carried out. Distributions of naturally occurring radioactive materials (NORM) of 226Ra, 232Th and 40K in the marine sediments were determined using NaI (Tl) γ-ray spectrometry. The average activities (range) of natural radionuclides in all wadis in the studied areas are 27.38 (18-48)Bqkg-1 for 226Ra, 38.45 (34-110)Bqkg-1 for 232Th and 419.4 (214-641)Bqkg-1 for 40K. These results are in agreement with earlier reported data. A comparison of radionuclide activities in the sediment of the studied areas and in other coastal and aquatic environments is given. The radiation hazard parameters (absorbed dose rate, radium equivalent activity and external hazard index) are calculated and compared with the reported data. The results of measurements will serve as base line data and background reference level for Egyptian coastlines. © 2010 Elsevier Ltd.


Because of the increasing use of phosphate in industry world wide, it is interesting to investigate the elemental concentration in phosphate ores. The present work determines the elemental analysis of two different types of phosphate ores, containing different amounts of P2O5 to check the level of the radioactive elements U and Th and of stable environmental pollutants like Cr, Zn in phosphate raw material. In addition, rare earth and other elements are analysed by the INAA method. This knowledge is found to be important in the assessment of possible radiological hazards to human health, since these materials may be used as building material or as phosphatic fertilizers and animal feed ingredients. © 2009 Elsevier Ltd. All rights reserved.


El-Taher A.,Al Azher University
Applied Radiation and Isotopes | Year: 2010

Instrumental neutron activation analysis (INAA) and HPGe detector γ-spectroscopy were used to determine a total of 16 elements qualitatively and quantitatively for the first time from feldspar rock samples collected from Gabel El Dubb, Eastern desert, Egypt. The elements determined are (Na, Mg, K, Sc, Ga, Cr, Fe, Co, Zn, Nb, Ba, Ce, Eu, Hf, Th and U). The samples were properly prepared together with their standard reference material and simultaneously irradiated by thermal neutrons at the TRIGA Mainz research reactor at a neutron flux of 7×1011 n/cm2 s. XRF was also used. Comparison of the results obtained by both techniques showed good agreement for such elements as K, Na, Fe, Mg, Ba and Cr. © 2010 Elsevier Ltd. All rights reserved.


El-Taher A.,Al Azher University
Applied Radiation and Isotopes | Year: 2010

Uranium isotopes found in soil, rock, water, plants, air, etc., contribute to the natural radiation exposure of the population. U concentrations in some Egyptian environmental samples like Toshki soil, Aswan iron-ore, and phosphate samples from El-Sibayia in the Nile Valley and El-Quseir in the Red Sea coast were determined using instrumental neutron activation analysis (INAA) and delayed neutron activation analysis (DNAA) in the Mainz TRIGA research reactor. The results showed that the phosphate rocks are rich natural sources of uranium among the other minerals forming the earth crust. © 2010 Elsevier Ltd.


Twenty representative geological samples (tonalite, granodiorite, adamellite, syenogranite, rapakivi syenogranite, alkali feldspar granite and monzogranite) were collected from G. Kattar area in Eastern Desert, Egypt, for analysis by instrumental neutron activation as a sensitive nondestructive analytical tool for the determination of 14 rare earth elements (REEs) and to find out the following: (1) what information could be obtained about the REEs and distribution patterns of REEs in geological samples under investigation, (2) to estimate the accuracy, reproducibility and detection limit of the INAA method in case of the given samples. The samples were properly prepared together with standard reference material and simultaneously irradiated in a neutron flux of 7×10 11n/cm 2s in the TRIGA Mainz research reactor facilities. The gamma spectra were collected by an HPGe detector and the analysis was done by means of a computerized multichannel analyzer. The choice of the nuclear reaction, irradiation and decay times, and of the proper gamma radiation in counting are presented and discussed. The results are found to be in good agreement with certified values. © 2010 Elsevier Ltd.

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