Factors Controlling Natural Radionuclides Migration in Sedimentary Rock Samples, Gabal Um-Hamd, Southwestern Sinai, Egypt

2019 ◽  
Vol 645 (14) ◽  
pp. 960-968 ◽  
Author(s):  
Nareman Harpy ◽  
Fatma Ragab ◽  
Zeinab Morsy ◽  
Mohamed A. E. Abdel-Rahman
Keyword(s):  
Sedimentary Rock ◽  
Natural Radionuclides ◽  
Rock Samples ◽  
Southwestern Sinai

Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt

2014 ◽  
Vol 134 ◽  
pp. 76-82 ◽  
Author(s):  
Maisa M. Amin ◽  
Ibrahim E. Elaassy ◽  
Mohamed G. El-Feky ◽  
Abdel Sattar M. Sallam ◽  
Mona S. Talaat ◽  
...  
Keyword(s):  
Sedimentary Rock ◽  
Rock Samples ◽  
Southwestern Sinai ◽  
Mineral Constituents

Behavior of Natural Radionuclides, Radiological Hazard Parameters, and Magnetic Minerals in Rock Samples of Kolli Hills, Eastern Ghats, India

2018 ◽  
Vol 12 (3) ◽  
pp. 399-412
Author(s):  
Nanjundan Krishnamoorthy ◽  
Basavaraj Rachappa Kerur ◽  
Sundaram Mullainathan ◽  
Marcos Adrian Eduardo Chaparro ◽  
Sugumaran Murugesan ◽  
...  
Keyword(s):  
Natural Radionuclides ◽  
Eastern Ghats ◽  
Radiological Hazard ◽  
Magnetic Minerals ◽  
Rock Samples ◽  
Kolli Hills ◽  
Hazard Parameters

Natural radionuclides in Niger delta sedimentary organic rock samples

2014 ◽  
Vol 9 (3) ◽  
pp. 169
Author(s):  
Akinsehinwa Akinlua ◽  
Josephine Omolara Fagbemi ◽  
F.O.I. Asubiojo ◽  
Nelson Torto
Keyword(s):  
Niger Delta ◽  
Natural Radionuclides ◽  
Rock Samples

scholarly journals Natural Radioactivity Measurements and Radiation Dose Estimation in Some Sedimentary Rock Samples in Turkey

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
I. Akkurt ◽  
K. Günoğlu
Keyword(s):  
Dose Rate ◽  
Natural Radioactivity ◽  
Sedimentary Rock ◽  
Annual Effective Dose ◽  
Hazard Index ◽  
Absorbed Dose ◽  
Absorbed Dose Rate ◽  
Rock Samples ◽  
External Hazard Index ◽  
Radium Equivalent

The natural radioactivity existed since creation of the universe due to the long life time of some radionuclides. This natural radioactivity is caused byγ-radiation originating from the uranium and thorium series and40K. In this study, the gamma radiation has been measured to determine natural radioactivity of238U,232Th, and40K in collected sedimentary rock samples in different places of Turkey. The measurements have been performed usingγ-ray spectrometer containing NaI(Tl) detector and multichannel analyser (MCA). Absorbed dose rate (D), annual effective dose (AED), radium equivalent activities (Raeq), external hazard index (Hex), and internal hazard index (Hin) associated with the natural radionuclide were calculated to assess the radiation hazard of the natural radioactivity in the sedimentary rock samples. The average values of absorbed dose rate in air (D), annual effective dose (AED), radium equivalent activity (Raeq), external hazard index (Hex), and internal hazard index (Hin) were calculated and these were 45.425 nGy/h, 0.056 mSv/y, 99.014 Bq/kg, 0.267, and 0.361, respectively.

Using Microfossils in Petroleum Exploration

1996 ◽  
Vol 2 ◽  
pp. 237-246
Author(s):  
Brian J. O'neill
Keyword(s):  
Sedimentary Rock ◽  
Drill Hole ◽  
The Other ◽  
Petroleum Exploration ◽  
Drill Bit ◽  
Rock Samples ◽  
The Earth ◽  
Other Hand ◽  
Invertebrate Fossils ◽  
Oil Company

When I meet new people and they find out that I'm a paleontologist working for an oil company, the second question they ask (after “What is a paleontologist?”) is usually “Why would an oil company hire one?” Most people think of dinosaurs or, at the very least, trilobites and other invertebrate fossils when they think of paleontology. However, most of the rock samples available to those engaged in finding and developing hydrocarbon resources are in the form of “cuttings.” Cuttings (Baker, 1979) are the small pieces of rock broken up by the drill bit and brought to the surface by the fluid which lubricates the drill bit and removes the cut rock from the bottom of the drill hole. If the bit encounters dinosaur bones or clam shells, they are so broken up in the process as to be almost unusable. Microfossils on the other hand, by virtue of their small size, can be recovered whole. Microfossils also happen to be abundant, especially in marine rocks, which are the most common form of sedimentary rock in the crust of the Earth.

EMPIRICAL STRENGTH ENVELOPE FOR SHALE

2016 ◽  
Vol 78 (7-3) ◽  
Author(s):  
Mohd For Mohd Amin ◽  
Nur‘Ain Mat Yusof ◽  
Rini Asnida Abdullah
Keyword(s):  
Failure Criterion ◽  
Sedimentary Rock ◽  
Triaxial Compression ◽  
Compression Tests ◽  
Failure Envelope ◽  
Rock Samples ◽  
Failure Envelopes ◽  
Project Site ◽  
Coulomb Criterion ◽  
Triaxial Compression Tests

Effectively, strength envelope describes behavior of rock when subjected to common stresses in construction, i.e. compressive, triaxial and tensile stresses. This study is aimed at investigating the strength envelope for shale, a sedimentary rock obtained from dam project site in Baram, Sarawak. Series of triaxial compression tests were carried out to obtain the strength envelope for the rock samples. For verification of failure criterion, uniaxial compression and Brazilian tests were also conducted on the rock samples. Results from the relevant tests were analysed using RocData software to obtain the strength envelope. Subsequently, Mohr-Coulomb and Hoek-Brown failure criterion are used to determine failure envelop for the rock samples. Based on the failure envelopes and the related strengths (i.e. compressive and tensile strength), suitability of both approach, in defining strength envelope for shale, is verified. The study shows that for highly laminated sedimentary rock like shale, Hoek-Brown criterion gave a more representative failure behaviour. The failure envelope clearly shown all the strength limits when the rock is subjected to triaxial, uniaxial and tensile stress, which is not clearly shown in the Mohr-Coulomb criterion. Therefore, Hoek-Brown criterion is a more appropriate method for describing strength envelope, as it able to show the limiting stresses when rock samples are subjected to common stresses in construction.

EFFECT OF WORKING CONDITIONS AND NATURAL RADIOACTIVITY LEVELS ON OCCUPATIONAL DOSES TO WORKERS OF AN OLD MANGANESE MINE

2020 ◽  
Vol 190 (3) ◽  
pp. 331-341
Author(s):  
Mohamed H E Monged
Keyword(s):  
Natural Radionuclides ◽  
Dose Assessment ◽  
Dose Equivalent ◽  
Rock Samples ◽  
Decay Products ◽  
Activity Concentrations ◽  
Radon Decay ◽  
Average Activity ◽  
Radiological Dose ◽  
Good Agreement

Abstract The aim of this work was to use RESRAD-Build model to predict the resulting external and internal radiological doses received by the workers of manganese mine located in Southern Sinai. In order to achieve that goal, measurement of the activity concentrations of natural radionuclides in rock samples collected from the inside gallery of such mine, using hyper pure germanium (HPGe) detector. Radon gas concentrations were also measured. The average activity concentrations of 238U, 226Ra, 232Th, 40K and 210Pb in rock samples were 207.3, 155.5, 59.7, 304.5 and 119.3 Bq kg–1, respectively. The average radon activity concentration was 1254.6 Bqm−3, which is equivalent to 0.135 WL. The radon concentration increases further as going deep inside the mine up to 6238 Bqm−3. RESRAD-Build model occupational effective dose equivalent (EDE) received by the workers, from natural radionuclides, dominated by 222Rn emanated from the parent nuclide 226Ra.There was good agreement between the occupational annual EDE calculated from the measured rock samples and that predicted by modeling, with estimated values of 83.8 and 82.1 mSvy−1, respectively. This radiological dose assessment indicated the predominance of internal pathways owing to radon decay products, in both cases (measured and modeled). The occupational radiological dose from the inhalation of radon and radon decay products resulted in a high lung cancer risk based on the current measurements and ventilation conditions within the mine.

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