a study on natural radioactivity in virgin and agricultural soil samples collected from sungai petani was conducted using high-purity germanium. the mean activity concentrations of 226ra, 232th, and 40k in virgin soils were 51.06±5.83, 78.44±6.42, and 125.66±7.26 bq kg−1, respectively, while those in agricultural soils were 80.63±5.78, 116.87±7.87, and 200.66±18.24 bq kg−1, respectively. the co...

the n-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. the quantum theoretical calculations for two crystal structures of n-(2-benzoyl-phenyl) oxalyl (compounds i and ii) were performed by density functional theory (b3lyp method and 6-311+g* basis set). from the optimized structures, geometric paramet...