Mostafa Anwar Mansour Ali creator preparation. Ali Y. Ellithi thesis advisor. A. R. Abdulghany thesis advisor. A. F. El Sayed thesis advisor. text theses ua 2025 monographic eng ara 92 pages : illustrations ; 25 cm. + CD. This study assesses the natural radioactivity levels and associated radiological hazards of twenty-eight black sand (BS) deposit samples collected along the Mediterranean Sea coast of North Sinai, Egypt. The samples were obtained from six locations: El Ressa, Abo Sakl, Ghornata, El Arish, El Masaed, and El Romana. The activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K were measured using a high-purity germanium (HPGe) detector with a relative efficiency of 100%. Standard methodologies were followed for sample selection, preparation, energy and efficiency calibration, minimum detectable activity (MDA) determination, and detector performance evaluation. Ambient dose rates at the sampling sites were monitored using two well-calibrated devices. The activity concentrations of Radium (226Ra), Thorium (232Th), and Potassium (40K) in the BS samples were found to vary across the sampling locations. For El Ressa, the activity concentrations ranged from 17.08 ± 0.26 to 29.41 ± 0.34 Bq/kg for 226Ra, 4.80 ± 0.26 to 15.71 ± 0.55 Bq/kg for 232Th, and 21.23 ± 2.26 to 79.48 ± 1.86 Bq/kg for 40K. In Abo Sakl, the ranges were 14.03 ± 0.26 to 28.99 ± 0.45 Bq/kg for 226Ra, 4.39 ± 0.30 to 15.14 ± 0.44 Bq/kg for 232Th, and 104.75 ± 1.87 to 126.35 ± 2.16 Bq/kg for 40K. Samples from Ghornata showed activity concentrations of 14.28 ± 0.30 to 25.09 ± 0.34 Bq/kg for 226Ra, 5.25 ± 0.34 to 11.67 ± 0.39 Bq/kg for 232Th, and 87.63 ± 1.83 to 109.13 ± 2.13 Bq/kg for 40K. For El Arish, the ranges were 14.65 ± 0.25 to 18.15 ± 0.32 Bq/kg for 226Ra, 4.83 ± 0.28 to 7.23 ± 0.49 Bq/kg for 232Th, and 66.19 ± 2.01 to 110.28 ± 1.91 Bq/kg for 40K. In El Masaed, the activity concentrations were 13.22 ± 0.32 to 17.72 ± 0.31 Bq/kg for 226Ra, 3.90 ± 0.25 to 6.67 ± 0.68 Bq/kg for 232Th, and 66.02 ± 1.20 to 108.90 ± 2.17 Bq/kg for 40K. Finally, El Romana samples exhibited activity concentrations of 13.73 ± 0.31 to 14.44 ± 0.26 Bq/kg for 226Ra, 3.82 ± 0.40 to 6.18 ± 0.53 Bq/kg for 232Th, and 267.09 ± 3.07 to 294.25 ± 4.09 Bq/kg for 40K. El Ressa samples exhibited the highest average activity concentrations for 226Ra and 232Th, while El Romana samples showed the highest levels of 40K. Radiological hazard indices, including the absorbed gamma dose rate (𝐷), annual effective dose (𝐸), radium equivalent activity (𝑅𝑎𝑒𝑞), and external (𝐻𝑒𝑥) and internal (𝐻𝑖𝑛) hazard indices, were calculated. All values were found to be significantly lower than the world average values and maximum permissible limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Additionally, ambient dose rates across the six studied areas ranged from 0.06 to 0.10 µSv/h, well below international safety thresholds. The results indicate that the black sand deposits along the North Sinai coast pose minimal radiological risks to public health and the environment under current conditions. This study highlights the effectiveness of HPGe gamma-ray spectrometry for precise and reliable radionuclide activity measurements and underscores the importance of continuous monitoring to ensure environmental and public safety. ﺗﻘﯿّﻢ ھﺬه اﻟﺪراﺳﺔ ﻣﺴﺘﻮﯾﺎت اﻟﻨﺸﺎط اﻹﺷﻌﺎﻋﻲ اﻟﻄﺒﯿﻌﻲ واﻟﻤﺨﺎطﺮ اﻹﺷﻌﺎﻋﯿﺔ اﻟﻤﺮﺗﺒﻄﺔ ﺑﮭﺎ ﻓﻲ ﺛﻤﺎﻧﯿﺔ وﻋﺸﺮﯾﻦ ﻋﯿﻨﺔ ﻣﻦ رواﺳﺐ اﻟﺮﻣﺎل اﻟﺴﻮداء اﻟﺘﻲ ﺟُﻤﻌﺖ ﻋﻠﻰ طﻮل ﺳﺎﺣﻞ اﻟﺒﺤﺮ اﻷﺑﯿﺾ اﻟﻤﺘﻮﺳﻂ ﻓﻲ ﺷﻤﺎل ﺳﯿﻨﺎء، ﻣﺼﺮ. ﺗﻢ ﺟﻤﻊ اﻟﻌﯿﻨﺎت ﻣﻦ ﺳﺘﺔ ﻣﻮاﻗﻊ: اﻟﺮﺳﺔ، أﺑﻮ ﺻﻘﻞ، ﻏﺮﻧﺎطﺔ، اﻟﻌﺮﯾﺶ، اﻟﻤﺴﺎﻋﯿﺪ، ورﻣﺎﻧﺔ. ﺗﻢ ﻗﯿﺎس ﺗﺮﻛﯿﺰات اﻟﻨﺸﺎط اﻹﺷﻌﺎﻋﻲ ﻟﻜﻞ ﻣﻦ اﻟﺮادﯾﻮم226- (²²6Ra) واﻟﺜﻮرﯾﻮم232- (²³²Th) واﻟﺒﻮﺗﺎﺳﯿﻮم40- (40K) ﺑﺎﺳﺘﺨﺪام ﻛﺎﺷﻒ اﻟﺠﺮﻣﺎﻧﯿﻮم ﻋﺎﻟﻲ اﻟﻨﻘﺎء (HPGe) ﺑﻜﻔﺎءة ﻧﺴﺒﯿﺔ ﺗﺒﻠﻎ 100٪. ﺗﻢ اﺗﺒﺎع ﻣﻨﮭﺠﯿﺎت ﻗﯿﺎﺳﯿﺔ ﻓﻲ اﺧﺘﯿﺎر اﻟﻌﯿﻨﺎت وﺗﺤﻀﯿﺮھﺎ، وﻣﻌﺎﯾﺮة اﻟﻄﺎﻗﺔ واﻟﻜﻔﺎءة، وﺗﺤﺪﯾﺪ اﻟﺤﺪ اﻷدﻧﻰ ﻟﻠﻨﺸﺎط اﻟﻘﺎﺑﻞ ﻟﻠﻜﺸﻒ (MDA) ، وﺗﻘﯿﯿﻢ أداء اﻟﻜﺎﺷﻒ. ﻛﻤﺎ ﺗﻢ ﻣﺮاﻗﺒﺔ ﻣﻌﺪﻻت اﻟﺠﺮﻋﺔ اﻟﻤﺤﯿﻄﺔ ﻓﻲ ﻣﻮاﻗﻊ أﺧﺬ اﻟﻌﯿﻨﺎت ﺑﺎﺳﺘﺨﺪام ﺟﮭﺎزﯾﻦ ﻣﻌﺎﯾﺮﯾﻦ ﺑﺪﻗﺔ. أظﮭﺮت ﻧﺘﺎﺋﺞ ﻗﯿﺎس اﻟﻨﺸﺎط اﻹﺷﻌﺎﻋﻲ ﺗﺒﺎﯾﻨًﺎ ﻓﻲ ﺗﺮﻛﯿﺰات اﻟﻨﻮﯾﺪات اﻟﻤﺸﻌﺔ ﺑﯿﻦ اﻟﻤﻮاﻗﻊ اﻟﻤﺨﺘﻠﻔﺔ. ﺗﺮاوﺣﺖ ﺗﺮﻛﯿﺰات اﻟﻨﺸﺎط اﻹﺷﻌﺎﻋﻲ ﻓﻲ ﻣﻮﻗﻊ اﻟﺮﺳﺔ ﺑﯿﻦ 0.26 ± 17.08 و 29.41±0.34 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺮادﯾﻮم226-، وﺑﯿﻦ 0.26 ± 4.80 و 15.71±0.55 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺜﻮرﯾﻮم232-، وﺑﯿﻦ 2.26 ± 21.23 و 79.48±1.86 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺒﻮﺗﺎﺳﯿﻮم.40- أﻣﺎ ﻓﻲ ﻣﻮﻗﻊ أﺑﻮ ﺻﻘﻞ، ﻓﻜﺎﻧﺖ اﻟﺘﺮاﻛﯿﺰ ﻓﻲ اﻟﻨﻄﺎق 0.26 ± 14.03 إﻟﻰ 28.99±0.45 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺮادﯾﻮم226-، و 0.30 ± 4.39 إﻟﻰ 15.14±0.44 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺜﻮرﯾﻮم232-، و 1.87 ± 104.75 إﻟﻰ±2.16 126.35 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺒﻮﺗﺎﺳﯿﻮم.40- أﻣﺎ اﻟﻌﯿﻨﺎت ﻣﻦ ﻣﻮﻗﻊ ﻏﺮﻧﺎطﺔ، ﻓﻘﺪ ﺗﺮاوﺣﺖ اﻟﺘﺮاﻛﯿﺰ ﺑﯿﻦ 0.30 ± 14.28و±0.34 25.09 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺮادﯾﻮم226-، و 0.34 ± 5.25 و ±0.39 11.67 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺜﻮرﯾﻮم232-، و 1.83 ± 87.63 و±2.13 109.13 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺒﻮﺗﺎﺳﯿﻮم40- . وﻓﻲ اﻟﻌﺮﯾﺶ، ﺗﺮاوﺣﺖ اﻟﻘﯿﻢ ﺑﯿﻦ 0.25 ± 14.65 و 18.15±0.32 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺮادﯾﻮم226-، و 0.28 ± 4.83 و±0.49 7.23 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺜﻮرﯾﻮم232- ، و2.01 ± 66.19 و±1.91 110.28 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺒﻮﺗﺎﺳﯿﻮم.40- ﺑﯿﻨﻤﺎ ﻛﺎﻧﺖ ﺗﺮﻛﯿﺰات اﻟﻨﺸﺎط اﻹﺷﻌﺎﻋﻲ ﻓﻲ اﻟﻤﺴﺎﻋﯿﺪ ﺑﯿﻦ 0.32 ± 13.22 و±0.31 17.72 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺮادﯾﻮم226-، و 0.25 ± 3.90 و0.68 6.67± ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺜﻮرﯾﻮم232-، و 1.20 ± 66.02 و±2.17 108.90 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺒﻮﺗﺎﺳﯿﻮم.40- وأﺧﯿﺮًا، أظﮭﺮت ﻋﯿﻨﺎت اﻟﺮﻣﺎﻧﺔ ﺗﺮاﻛﯿﺰ ﺗﺘﺮاوح ﺑﯿﻦ 0.31 ± 13.73 و 14.44±0.26ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺮادﯾﻮم226-، و 0.40 ± 3.82 و 0.53 6.18± ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺜﻮرﯾﻮم232-، و 3.07 ± 267.09 و4.09 ± 294.25 ﺑﻜﺮﯾﻞ/ﻛﻐﻢ ﻟﻠﺒﻮﺗﺎﺳﯿﻮم.40- أظﮭﺮت ﻋﯿﻨﺎت اﻟﺮﺳﺔ أﻋﻠﻰ ﻣﺘﻮﺳﻂ ﻟﺘﺮﻛﯿﺰات اﻟﻨﺸﺎط اﻹﺷﻌﺎﻋﻲ ﻟﻜﻞ ﻣﻦ اﻟﺮادﯾﻮم226- و اﻟﺜﻮرﯾﻮم232-، ﺑﯿﻨﻤﺎ ﺳﺠﻠﺖ ﻋﯿﻨﺎت اﻟﺮﻣﺎﻧﺔ أﻋﻠﻰ ﺗﺮﻛﯿﺰات ﻟﻠﺒﻮﺗﺎﺳﯿﻮم.40- ﺗﻢ ﺣﺴﺎب ﻣﺆﺷﺮات اﻟﻤﺨﺎطﺮ واﻟﻨﺸﺎط اﻟﻤﻜﺎﻓﺊ ﻟﻠﺮادﯾﻮم (Raeq) ، وﻣﺆﺷﺮي اﻟﺨﻄﻮرة اﻟﺨﺎرﺟﯿﺔ (Hex) واﻟﺪاﺧﻠﯿﺔ (Hin). ﺗﺒﯿﻦ أن ﺟﻤﯿﻊ اﻟﻘﯿﻢ أﻗﻞ ﺑﻜﺜﯿﺮ ﻣﻦ اﻟﻤﺘﻮﺳﻄﺎت اﻟﻌﺎﻟﻤﯿﺔ واﻟﺤﺪود اﻟﻘﺼﻮى اﻟﻤﻮﺻﻰ ﺑﮭﺎ ﻣﻦ ﻗﺒﻞ اﻟﻠﺠﻨﺔ اﻟﻌﻠﻤﯿﺔ اﻟﺘﺎﺑﻌﺔ ﻟﻸﻣﻢ ﻋﻼوة ﻋﻠﻰ ذﻟﻚ، ﺗﺮاوﺣﺖ ﻣﻌﺪﻻت اﻟﺠﺮﻋﺔ (UNSCEAR). اﻟﻤﺘﺤﺪة اﻟﻤﻌﻨﯿﺔ ﺑﺂﺛﺎر اﻹﺷﻌﺎع اﻟﺬري اﻟﻤﺤﯿﻄﺔ ﻓﻲ اﻟﻤﻨﺎطﻖ اﻟﺴﺖ اﻟﻤﺪروﺳﺔ ﺑﯿﻦ 0.06 و0.10 ﻣﯿﻜﺮوﺳﯿﻔﺮت/ﺳﺎﻋﺔ، وھﻲ أﻗﻞ ﺑﻜﺜﯿﺮ ﻣﻦ اﻟﺤﺪود اﻟﺪوﻟﯿﺔ اﻟﻤﺴﻤﻮح ﺑﮭﺎ. ﺗﺸﯿﺮ اﻟﻨﺘﺎﺋﺞ إﻟﻰ أن رواﺳﺐ اﻟﺮﻣﺎل اﻟﺴﻮداء ﻋﻠﻰ طﻮل ﺳﺎﺣﻞ ﺷﻤﺎل ﺳﯿﻨﺎء ﻻ ﺗﺸﻜﻞ ﻣﺨﺎطﺮ إﺷﻌﺎﻋﯿﺔ ﻛﺒﯿﺮة ﻋﻠﻰ اﻟﺼﺤﺔ اﻟﻌﺎﻣﺔ أو اﻟﺒﯿﺌﺔ ﻓﻲ ظﻞ اﻟﻈﺮوف اﻟﺤﺎﻟﯿﺔ. ﺗﺆﻛﺪ ھﺬه اﻟﺪراﺳﺔ ﻋﻠﻰ ﻓﻌﺎﻟﯿﺔ ﺗﻘﻨﯿﺔ ﻗﯿﺎس اﻟﻄﯿﻒ اﻹﺷﻌﺎﻋﻲ ﺑﺄﺷﻌﺔ ﻏﺎﻣﺎ ﺑﺎﺳﺘﺨﺪام HPGe ﻓﻲ ﻗﯿﺎس ﺗﺮاﻛﯿﺰ اﻟﻨﻮﯾﺪات اﻟﻤﺸﻌﺔ ﺑﺪﻗﺔ وﻣﻮﺛﻮﻗﯿﺔ، ﻛﻤﺎ ﺗﺴﻠﻂ اﻟﻀﻮء ﻋﻠﻰ أھﻤﯿﺔ اﻟﺮﺻﺪ اﻟﻤﺴﺘﻤﺮ ﻟﻀﻤﺎن اﻟﺴﻼﻣﺔ اﻟﺒﯿﺌﯿﺔ واﻟﺼﺤﯿﺔ. specialized by Mostafa Anwar Mansour Ali ; Supervision Dr. Ali Y. Ellithi, Dr. A. R. Abdulghany, Dr. A. F. El Sayed. Thesis (M.Sc)-Cairo University, 2025. Bibliography: pages 80-89. Issues also as CD. Text in English and abstract in Arabic & English. Nuclear physics اﻟﻔﯿﺰﯾﺎء اﻟﻨﻮوﯾﺔ HPGe gamma spectrometry radiological risk assessment black sand deposits North Sinai coast natural radioactivity hazard indices HPGe ﻗﯿﺎس اﻟﻄﯿﻒ اﻹﺷﻌﺎﻋﻲ ﺑﺄﺷﻌﺔ ﻏﺎﻣﺎ ﺗﻘﯿﯿﻢ اﻟﻤﺨﺎطﺮ اﻹﺷﻌﺎﻋﯿﺔ 539.7 EG-GICUC 260509 20260509164113.0 eng