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Measurement of radon concentrations in soil and the extent of their impact on the environment from Al-Qassim, Saudi Arabia

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Natural Science 2013年第1期5卷 93-98页

作者： wedad reif alharbi Adel G. E. Abbady hysics Department Faculty of Science South Valley University Qena Egypt Physics Department Faculty of Science King Abdulaziz University Jeddah KSA

Soil gas radon 222Rn concentration was measured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were taken for soil gas measurements, staring from the ground surface. The results suggested that the largest concentration was 340 ± 22 Bq/m3 for 60cm depth at in Al-Tarfia point sample P3, and the smallest concentration was 26 ± 5 Bq/m3 for surface 0 cm depth at El-Bakria, point sample P5. The results obtained from this study indicate that the region has background radioactivity levels within the natural limits.

关键词： Natural Radioactivity Radon Soil Alpha Guard

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An investigation of planetary nebulae accompanying PG 1159 central stars,based on Gaia DR2 measurements

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Research in Astronomy and Astrophysics 2021年第6期21卷 397-402页

作者： Alaa Ali wedad R.alharbi Department of Astronomy Faculty of ScienceCairo University12613 GizaEgypt Department of Physics College of ScienceUniversity of Jeddah23890 JeddahSaudi Arabia

This article discusses the physical and kinematical characteristics of planetary nebulae accompanying PG 1159 central *** study is based on the parallax and proper motion measurements recently offered by the Gaia space *** approaches were used to investigate the kinematical properties of the *** results revealed that most of the studied nebulae arise from progenitor stars in the mass range 0.9-1.75 M⊙.Furthermore,they tend to live within the Galactic thick disk and move with an average peculiar velocity of 61.7±19.2 km s^(-1) at a mean vertical height of 469±79 *** locations of the PG 1159 stars on the H-R diagram indicate that they have an average final stellar mass and evolutionary age of 0.58±0.08 M⊙and 25.5±5.3×103 yr,*** found a good agreement between the mean evolutionary age of the PG 1159 stars and the mean dynamical age of their companion planetary nebulae(28.0±6.4×103 yr).

关键词： planetary nebulae:general methods:kinematics stars:individual(PG 1159)

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Investigation on ²²⁶Ra, ²³⁸Th, 40⁴⁰K and ¹³⁷Cs Concentrations in Common Polishing Materials Consumed by Inhabitants in Saudi Arabia

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Journal of Environmental Protection 2016年第11期7卷 1466-1472页

作者： wedad Rayif alharbi Department of Physics Faculty Science King Abdulaziz University Jeddah Saudi Arabia

Knowledge of radioactivity present in polishing materials enables one to assess any possible radiological risks to human health. In this work, the radioactivity due to the presence of 226Ra, 232Th, 40K, and 37Cs has been measured in polishing materials con-sumed in Saudi Arabia using gamma spectrometry with HPGe. The activity concentra-tions of 226Ra, 232Th, 40K and 137Cs ranged from 13.61 ± 0.005 to 0.60 ± 0.002, 18.43 ± 0.003 to 0.78 ± 0.001, 342.59 ± 0.009 to 2.47 ± 0.001 and 1.47 ± 0.001 to 0.55 ± 0.001 Bq/l, respectively. For 226Ra and 40K, the highest values are measured in stainless steel polisher. The highest values also measured in metal polisher (copper-chrome) and disinfectant cleaner and polisher sample for 232Th and 137Cs. Radium equivalent activ-ity due to the natural radioactivity of the investigated samples ranged from 51.37 to 1.24 Bq/l. This value is less than the recommended values in the established standards. The evaluated data were compared with the literature data. Our results indicate that no significant radiological hazards arise from using investigated samples hence quite safe to be used as polishing materials.

关键词： Gamma Spectrometry Radiation Hazard Polishing Materials Natural Radioactivity

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