Influences of COVID-19 Pandemic Lockdown on Excess Lifetime Cancer Risk Value of Natural Radiation

Abstract: This study focuses on the consequences of the COVID-19 pandemic on annual effective doses and excess lifetime cancer risk values due to ionizing radiation and radon which has been reported UNSCEAR 2000. The random data collection questionnaire method was applied to assess the indoor and outdoor occupancy factor for three age groups during the epidemic in Turkey. The results indicated age group C (Age > 65 y) has more influence from pandemic indoor and outdoor occupancy factor. As compared to before pandemic data in study area and global average exposure to natural radioactive sources. Graphic abstract: [Figure not available: see fulltext.] © 2021, Akadémiai Kiadó, Budapest, Hungary.This research was supported by Project No (TURSP-2020/45) Taif University, Saudi Arabia. Also, the authors are grateful to the University of Kyrenia research group for the use of their facilities

The Impact of PbF2-Based Glasses on Radiation Shielding and Mechanical Concepts: An Extensive Theoretical and Monte Carlo Simulation Study

This work aimed to investigate the impact of Lead-fluoride based glasses via theoretical and simulation techniques on mechanical and radiation shielding parameters. Accordingly, Bi2O3 was blended with TeO2–B2O3–PbF2 glasses by using melt-quenching method. Using Fluka Monte Carlo code, the radiation shielding properties have measured. Moreover, Comparatively higher density PbF80 = 6.163 g/cm3 with 80 mol % Bi2O3, greater µ, µm and Zeff and lower T1/2, λ, tenth value layer values achieved for TeO2–B2O3– PbF2/Bi2O3 glass pointed it out as the best shield of gamma. Besides, the computed effective removal cross-sections against fast neutrons (ΣR) observed that the PbF80 sample has commensurately greater with a value 5.2954 (cm−1). The results observed that the variation PbF2/Bi2O3 improves the gamma protection ability of Lead-fluoride based glasses. The incremental of Bi2O3 at the expense of PbF2 increases the density and the packing density of the glasses and hence increase the longitudinal modulus-L, shear modulus-S, bulk modulus-K, and Young's modulus-Y from 15.89 to 25.9 GPa, from 8.49 to 12.09 -GPa, from 4.58 to 9.77 GPa, and from 15.74 to 25.69 GPa, respectively. The increase of the elastic moduli can be attrinuted to the glass former role of Bi2O3. The results indicate that the highest PbF2/Bi2O3 ratio encoded PbF00 has the best shielding and mechanical competence with measurable physical properties. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Taif University Researchers Supporting Project number (TURSP-2020/45) Taif University, Taif, Saudi Arabia

A comprehensive first principles calculations on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 single-cubic-perovskite superconductor

In this present study, the pseudopotential plane-wave (PP-PW) pathway in the scheme of density functional theory (DFT) is utilized to investigate the various physical properties on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 (BKBPO) single perovskite superconductor. We have analyzed elastic constants and moduli at zero and elevated pressures (up to 25 GPa) as well. We also have investigated the anisotropic nature incorporating both the theoretical indices and graphical representations in 2D and 3D dimensions, which reveals a high level of anisotropy. The flatness of the energy bands near EF is a sign of Van-Hf singularity that might increase the electron pairing and origination of high-TC superconductivity. The computed band structure exhibits its metallic characteristics is confirmed by band overlapping. A band of DOS is formed for the strong hybridization of the constituent elements. The orbital electrons of O-2p contribute most dominantly at EF in contrast to all orbital electrons. The orbital electrons at the EF are higher from both the partial density of states and charge density mapping investigation. The coexistence of the electron and hole-like Fermi sheets exhibits the multi-band nature of BKBPO. On the other hand, Fermi surfaces with flat faces promote transport features and Fermi surface nesting as well. The calculated value of the electron-phonon coupling constant ({\lambda} = 1.46) is slightly lower than the isostructural superconductor, which indicates that the studied BKBPO can be treated as a strongly coupled superconductor similar to the reported isostructural perovskite superconductors. Furthermore, the thermodynamic properties have been evaluated and analyzed at elevated temperature and pressure by using harmonic Debye approximation (QHDA).Comment: 20 pages, 7 figures, 6 table

Aging effect on the structure and optical properties of nano Cu2S films

The amorphous nature is the dominant state of the as deposited Cu2S films. Films were aged for 3, 6 and 12 months. The aged films of 12 months are poly crystalline within nano scale. (102), (110), (103) and (112) were the preferred orientations of 12 months of aging. The calculated crystallite sizes were 13, 29, 33 and 54 nm respectively. The optical gap is direct; it increases with the increasing of aging time as well as oscillation energy and constant A. Refractive index, the infinity dielectric constant, the lattice dielectric constant the real and the imaginary part of the dielectric constant, the ratio of carrier concentration to the effective mass, the dispersion energy are decreasing with the increasing of aging time. Optical conductivity and energy loss function were studied; both decrease by the increasing of aging time. Keywords: Aging, Structure of nano crystals and nano particles, Optical constants, Optical properties of thin films, Amorphous semiconductors, Glasse

The effect of thickness on the structural and optical properties of nano Ge-Te-Cu films

Quartz was used as a substrate to hold different film thicknesses of Ge0.15Te0.78Cu0.07 within range 100–500 nm prepared by thermal evaporation technique. Films are still amorphous up to 200 nm and turn to more ordered nano polycrystalline one by ascending the values of film thickness up to 500 nm. Films turn to crystalline phase due to annealing. The relation of resistance and temperature shows phase transformation. Optical constants; refractive index, n absorption coefficient, α single-oscillator energy, Eo dispersion energy, Ed lattice dielectric constant, εL infinite wavelength dielectric constant, ε∞ the ratio of the carrier concentration to the effective mass, N/m∗ optical conductivity, σ and energy loss function, ELF show decreasing values with thickness up to 200 nm followed by ascending values within range 200–500 nm. It is concluded that the thickness range 100–200 nm introduces more disordered films while 200–500 nm introduces more ordered one. Keywords: GeTeCu alloys, Structural properties, Optical properties, Thickness, Nano materials, Phase change memor

Thermoelectric properties and mobility activation energy of amorphous As

Thermal evaporation technique was used to prepare As20Se80−xTlx films from bulk materials; ($5\leqslant x\leqslant 35$ at.%). The effect of TI addition on the thermoelectric properties and mobility activation energy of As-Se-Tl chalcogenide semiconductors has been studied in the homogeneous glass-forming region through temperature range (300–380 K). The thermoelectric power, TEP had a positive sign over the whole temperature range investigated, indicating p-type conductivity for As20Se80−xTlx films. TEP activation energy, $\Delta E_{s}$ could be calculated from TEP measurements. It was found that $\Delta E_{s}$ decreases with increasing Tl-content and is found to vary between 0.814 and 0.517 eV. The mobility activation energy, $\Delta E_{Q}$ could be calculated