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The determination of stopping power and the range of protons present in CH3OH, CH2O, and CO2 was accomplished within the energy range of 0.01–1,000 MeV by employing the Bethe equation and Ziegler equation. The latter two equations utilize quantum mechanics to derive an approximation of the stopping force formula, which applies to highly charged particles. The software MATLAB was utilized in the calculation of the results. A suitable equation for computing the halting power of protons in the range of 0.01–1,000 MeV has been identified. A correlation coefficient of 0.999 was determined, suggesting a high degree of concordance between the derived results and those of the SRIM 2013 and P-STAR programs. Proton stopping power analyses of this nature will aid the scientific community in selecting the optimal formulation of stopping power.

Stopping power, range, and time of proton in water, lung, bladder, and intestinal human tissues are calculated using density functional theory and Beth’s relativistic equation in range of proton energy (0.01–1,000 MeV). The experimental data extracted from SRIM-2013 program were used to proton to the same human tissues applied in the MATLAB-2021 program, and the mean ionization potential of water and the studied tissues is calculated using Gaussian 09W program. A good agreement has been found between our calculations for stopping power, range, and time of protons in the studied human body tissues and SRIM-2013 program calculations.

In this study, the energy loss, range, and stopping time were calculated using the Bethe theory for protons in germanium and copper materials over an energy range of 0.01–1,000 MeV. The mathematical equations were programmed and implemented using MATLAB2013 to obtain the results for the relative mass stopping power and range, illustrated in tables and graphs. The computed results from the Bethe and Ziegler equations were compared with the experimental results from Pstar. The results showed a difference between the experimental and theoretical results at the beginning of the range used in the Bethe equation because it is a quantized equation that is not suitable for low energies. Hence, a correction term was proposed for the Bethe equation to correct the results at low energies, which produced negative values. On the other hand, the Ziegler equation showed good agreement along the range used as it is a semi-empirical equation. The range and stopping time of the incident particle increased with increasing incident particle energy in the mentioned materials.

The study aimed to clarify the legal regulation of the volunteer employment contract in the Kingdom of Saudi Arabia, through the Saudi volunteer work law and its executive regulations. To achieve this goal, the research was divided into an introduction and three sections: The introduction dealt with the concept of volunteer work, while the first section was devoted to explaining the concept of the volunteer work contract. The second section dealt with the effects of the volunteer work contract, and finally, the third section dealt with the termination of the volunteer work contract. The researcher used the descriptive and analytical approach as well as the comparative approach. The study concluded with many results including that the essence of volunteer work is to achieve public benefit without compensation, and that if the work or effort is in exchange for a financial reward, then it does not have the status of volunteer work. The results also showed that the expiration of a volunteer work contract is subject to the general causes of expiration and dissolution of contracts in general. In addition to being subject to special reasons related to it due to its characteristics. As for the recommendations, the study recommended several recommendations, the most prominent of which is: that volunteer work in the Saudi system be within the framework of a written contract between the volunteer or volunteer team and the beneficiary. [ABSTRACT FROM AUTHOR]