This study investigated the influence of tissue electron density on proton beam dose distribution using TOPAS Monte Carlo simulation. Heterogeneous tissue models composed of 14 materials were constructed to simulate the dose deposition process of a 169.23 MeV proton beam. The study analyzed the relationships between electron density and key parameters such as maximum dose, total dose, and dose distribution. Results showed that increasing electron density led to higher local maximum dose, lower total dose, and decreased Bragg peak depth, range, penumbra width, and full width at half maximum (FWHM). High-density tissues caused a sharp, concentrated Bragg peak at shallower depths, while low-density tissues caused a backward shift and widening of the Bragg peak. Differences in proton energy deposition in various tissues were the fundamental reasons for dose distribution variations. This study quantified the relationship between electron density and proton beam dose distribution, providing a reference for accurate dose calculation and optimization in proton therapy.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.apradiso.2025.111665 | DOI Listing |
Sci Rep
January 2025
Department of Physics, Faculty of Science, Fasa University, Fasa, 74616-86131, Iran.
In this work, we explored the role of a single electron in the energy of neutral and charged clusters of using data visualization and statistical techniques as a new insight. Initially, we studied the effects of one electron, time, and temperature on energy using multiple linear regression analysis with dummy variables, and the results demonstrated that all three predictors significantly affected the energy. Time had a positive impact (direct ratio effect) on the energy of , and and a negative impact (inverse ratio effect) on the energy of while temperature had a positive effect on the energy of all three sodium clusters.
View Article and Find Full Text PDFEnviron Pollut
January 2025
College of Land Resources and Environment, Jiangxi Agricultural University, Nanchang, 330045, P.R. China.
Propyrisulfuron, a novel sulfonylurea herbicide, effectively suppresses intracellular acetolactate synthase activity for weed control, but its adsorption behavior in the soil environment remains unclear. To assess potential agroecosystem risks, the adsorption-desorption behavior and mechanism of propyrisulfuron in six typical agricultural soils of China were investigated using a batch equilibrium method, Density Functional Theory (DFT), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy equipped with Energy Dispersive X-ray (SEM-EDX) techniques. It is indicated that the adsorption-desorption of propyrisulfuron in six soils reached equilibrium at 36 hours under the optimum water-to-soil ratio (WSr) of 5:1.
View Article and Find Full Text PDFEnviron Res
January 2025
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Key Laboratory of Renewable Energy, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of High-Quality Recycling of End-of-Life New Energy Devices, Guangzhou 510640, China. Electronic address:
Hydrogen sulfide (HS) is a major air pollutant posing a serious threat to both the environment and public health. In this study, a novel nitrogen-rich biocarbon that effectively removes HS was produced from a mixture of sewage sludge and pine sawdust using melamine as nitrogen source. Compared with pristine biocarbons, nitrogen (N)-doped biocarbons possessed an adjustable porosity, e.
View Article and Find Full Text PDFWater Res
January 2025
China Electronics System Engineering No.2 Construction Co., Ltd., Wuxi 214115, PR China.
Copper-containing industrial wastewater, characterized by strong acidity, high ionic strength, and various competing metals, presents significant challenges for Cu(II) recovery. To address these issues, an electric field-enhanced ultrafiltration process was developed, assisted with a functional polyelectrolyte with high selectivity for Cu(II). The polyelectrolyte, termed PPEI, was synthesized by grafting picolyl groups onto polyethyleneimine (PEI), enhancing its affinity for Cu(II).
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China. Electronic address:
Developing efficient catalysts to enhance photoreduction carbon dioxide (CO) into hydrocarbon fuels is a great challenge. As metallic material, molybdenum dioxide (MoO) has very high conductivity and charge density, which make it a promising candidate as photocatalyst. However, its photocatalytic activity is limited by the serious charge recombination.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!