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The raw materials of cement contain radioactive elements that come from natural sources. Members of the decay chains of uranium, thorium, and potassium radioisotope ⁴⁰K are the primary sources of this radioactivity. The natural radionuclide concentration levels in cement differ greatly depending on different geographic areas. To estimate the radionuclides concentration in cement specimens from twelve diverse Pakistani companies, gamma-ray spectroscopy analysis was used in the study. ²²⁶Ra, ²³²Th, and ⁴⁰K had activity concentration levels ranging from 18.08 to 43.18 Bq/kg, 16.73 to 23.53 Bq/kg, and 14.24 to 315.22 Bq/kg, respectively. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) threshold for the ²²⁶Ra was surpassed by five of the studied samples. The indoor and outdoor dose rates as well as different radiological health hazard indices were also examined. The Indoor Absorbed Dosage (D_in) for some of the samples exceeded the permissible limit. These samples also had a high Indoor Effective Lifetime Cancer Risk (ELCR) factor, which makes them unsafe for interior construction purposes. The outdoor dosages as well as the hazard indices were well within the permitted ranges. The outdoor ELCR factor is low for all the cement brands, which makes them safe for exterior construction purposes. The findings were compared with published data from other countries around the globe. Finally, a thorough statistical analysis was performed and Pearson’s Correlation Coefficient (r) exhibited a very strong correlation between the different outdoor and indoor radiological health hazard indices. Full article

Rust is a new system-level programming language that prioritizes performance, safety, and productivity. However, as evidenced in many previous works, unsafe code fragments broadly exist in Rust projects. The use of these unsafe fragments can fundamentally violate the safety of systems developed using the programming language. In response to this problem, we propose a novel methodology (Thetis) to enhance the safety capability of Rust. The core idea of Thetis is to reduce unsafe code, encapsulate unsafe code using safety rules, and make it easier to verify unsafe code through formal means. The proposed methodology involves three main components. In the context of Rust itself, Thetis combines replacement and encapsulation for Interior Unsafe segments, minimizing unsafe fragments and reducing unsafe operations and their range. For systems developed using Rust, new ACSL formal statutes are applied to reduce the unsafe potential of the encapsulated Interior Unsafe segments, enhancing the safety of the system. Regarding the development life cycle in Rust, Thetis introduces automatic defect detection and optimization based on feature extraction, improving engineering efficiency. We demonstrate the effectiveness of Thetis by using it to fix defects in BlogOS and ArceOS. The experimental results reveal that Thetis reduces the number of unsafe operations in these OSs by 40% and 45%, respectively. The use of Miri to detect and eliminate defects in ArceOS reduces the likelihood of undefined behavior by about 50%, which effectively demonstrates that the proposed method can improve the safety of the Rust system. In addition, performance test results from LMbench show that the performance loss caused by Thetis is only 1.076%, thereby maintaining the high-performance characteristics of the Rust system. Full article