000			03285cam a2200313 a 4500
003			EG-GiCUC
008			180419s2017 ua dh f m 000 0 eng d
040			_aEG-GiCUC _beng _cEG-GiCUC
041	0		_aeng
049			_aDeposite
097			_aM.Sc
099			_aCai01.12.20.M.Sc.2017.En.A
100	0		_aEnas Khalifa Mahfouz Khalifa
245	1	0	_aAssessment of environmental hazards of natural radioactivity emitted and heavy elements exist in local cement in Egypt / _cEnas Khalifa Mahfouz Khalifa ; Supervised Saher Mohamed Darwish Ahmed , Mogahed Ebrahim Ali Alabyad
246	1	5	_aتقييم المخاطر البيئية للنشاط الإشعاعي الطبيعي المنبعث و العناصر الثقيلة الموجودة في الأسمنت المحلي في مصر
260			_aCairo : _bEnas Khalifa Mahfouz Khalifa , _c2017
300			_a98 , 35 P. : _bcharts , facsimiles ; _c25cm
502			_aThesis (M.Sc.) - Cairo University - Faculty of Science - Department of Physics
520			_aThe principal aim of this thesis is to investigate the radiological hazard for cement samples and measure the heavy elements and toxic substances in them. Using Þ spectrometry, the concentration of natural radionuclides 238U, 232Th and 40K has been determined in cement and its raw materials which are utilized as construction materials in Egypt. Twenty three samples of raw materials and final products utilized in the cement factories were collected for study. Thirteen samples were obtained from (Limestone, Clay, Slag, Clinker, gypsum) which represent the raw materials utilized in cement industry and ten samples of final products of commercial cement were obtained from (Portland, El-Mohands and White cement). The activity concentration of 238U, 232Th and 40K in raw materials were observed to be ranged from (56.32 to 615.59) Bq/kg, (11.47 to 77.05) Bq/kg and (68.36 to 948.07) Bq/kg with mean value 134.07, 35.97 and 403.48 Bq/kg for 238U, 232 40 238 232 40 Th and K, respectively. The activity concentration of U, Th and K in final products were observed to be ranged from (62.93 to 234.73 Bq/kg), (20.10 to 38.07 Bq/kg) and (200.53 to 306.58 Bq/kg) with mean value 93.49,29.64 and 257.90 Bq/kg for 238U, 232Th and 40K, respectively. The permissible activity levels of building materials are (50, 50 and 500) Bq/kg for 226Ra, 232Th and 40K, respectively [NEA-OECD, 1979 and UNSCEAR, 1993]. All concentration values of 238U in raw materials and final products are higher than recommended value. The concentration values of 232Th in raw materials and final products are lower than recommended value except sample S1, S3, S8, S10 and S13. The concentration values of 40K in raw materials and final products are lower than recommended value except samples S3, S8 and S13. The results of concentration levels are compared with other measurements from different parts of the world
530			_aIssued also as CD
653		4	_aEnvironmental hazards
653		4	_aLocal cement in Egypt
653		4	_aNatural radioactivity emitted
700	0		_aMogahed Ebrahim Ali Alabyad , _eSupervisor
700	0		_aSaher Mohamed Darwish Ahmed , _eSupervisor
905			_aEnas _eCataloger
905			_aNazla _eRevisor
942			_2ddc _cTH
999			_c65950 _d65950