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Byline: Musa. Joya, Hassan. Nedaie, Ghazale. Geraily, Hadi. Rezaei, Awaz. Bromand, Mahdi. Ghorbani, Peyman. Sheikhzadeh Purpose: According to the revised Task Group number 43 recommendations, a brachytherapy source must be [...]

Topological insulators are materials that in bulk mode have band gap such as an ordinary insulator but can protect the conduction mode at the edge or surface, i.e. apart from a simple and insulated metal. These materials are insulator in their bulk modes but are metal at the surface. Topological insulators are developed in two and three dimensions. Recently, compounds of the Bi2Se3 have attracted a huge attention because of existence of a Dirac cone in their surface state, having a suitable bandgap (0.3 eV), and easy santhesis. In this research, we investigate the properties of this material using density functional theory. The main focus is on bulk calculations and surface properties. The band structure of this material is studied in bulk mode without any consideration of spin - orbit interaction. Then a surface of this material is considered and its band structure and density of states are studied. The results show that the surface of this material has a Dirac cone. [ABSTRACT FROM AUTHOR]

In this article, multilayer nanowires (Ag/Co/Zn) were produced by electrochemical deposition in the form of anodic aluminum oxide. The electrochemical deposition method to produce nanowires are performed by three different methods. We have examined the pulsed periodic method, and we have managed to fabricate the nanowires of Ag/Co/Zn. Then, the produce nanowires are confirmed by the SEM and XRD analyses. Anodic nanoporous alumina with a thickness of 205 nm and a distance between pores of about 250 nm is produced by combining hard and soft anodization. Two-step anodization method including soft anodization and hard anodization was performed. These two anodizations were performed using 0.3 M oxalic acid as electrolyte at 0 degrees Celsius and applying voltages of 40 and 130 volts, respectively. Then the potential was reduced from 130V to 12V to thin the barrier layer. Multilayer nanowire arrays had been electrodeposited into the pores of anodic aluminum oxide (AAO) template. The electrochemical impedance spectroscopy has been carried out to study the in situ growth process of multilayer nanowires at different electrodeposition times. [ABSTRACT FROM AUTHOR]

Purpose: According to the revised Task Group number 43 recommendations, a brachytherapy source must be validated against a similar or identical source before its clinical application. The purpose of this investigation is to verify the dosimetric data of the high dose rate (HDR) BEBIG 192 Ir source (Ir2.A85-2)., Materials and Methods: The HDR 192 Ir encapsulated seed was simulated and its main dosimetric data were calculated using Geant4 Application for Tomographic Emission (GATE) simulation code. Cubic cells were used for the calculation of dose rate constant and radial dose function while for anisotropy function ring cells were used. DoseActors were simulated and attached to the respective cells to obtain the required data., Results: The dose rate constant was obtained as 1.098 ± 0.003 cGy.h - 1 .U - 1 , differing by 1.0% from the reference value reported by Granero et al . Similarly, the calculated values for radial dose and anisotropy functions presented good agreement with the results obtained by Granero et al ., Conclusion: The results of this study suggest that the GATE Monte Carlo code is a valid toolkit for benchmarking brachytherapy sources and can be used for brachytherapy simulation-based studies and verification of brachytherapy treatment planning systems., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Journal of Medical Physics.)