We have considered the production of bromine isotopes by studying the cross-sections of nuclear reactions in the selenium enriched target. This is of importance due to the applications in nuclear medicine and radiation therapy. Eight channels are observed in the production of bromine isotopes: 7634Se(p, 2n) 7535Br, 7734Se(p, 3n) 7535Br, 7634Se(p, n) 7635Br, 7734Se(p, 2n) 7635Br, 7734Se(p, n) 7735Br, 7834Se(p, 2n) 7735Br, 8034Se(p, 4n) 7735Br, and 8034Se(p, n) 8035mBr. The energy of the interacting protons ranging from the threshold is 2.20–84.20 MeV and is calculated by using an activation technique. For the proton-induced production of bromine isotopes from selenium target atoms, the stopping power and the yield have been calculated. The Zeigler formula was applied to investigate the cross-sections and to determine the yield for each reaction over the stopping power range. The total energy of each reaction and the corresponding crosssections are statistically analyzed. These energies are reproduced by the incident proton energy with acceptable errors at 0.01 MeV intervals. One of the most significant results of the current calculations is the stopping power of targets evaluated within the Ziegler and SRIM approaches.

In general, the transition elements, including Hafnium (Hf), have become the focus of researchers' attention, as when they combine with chalcogens and halides, they turn into semiconductors with distinct energy gaps. Moreover, chalcogens and halides are desirable in scientific research when forming layers or membranes. The Janus monolayer is unique two-faced material composed of two different chemical species on opposite sides of a single layer. Herein, we use first-principles simulations to thoroughly investigate the electrical and optical properties of this material. Our calculations reveal that the Bromochlorohafnium (HfClBr) Janus monolayer is an indirect semiconductor at equilibrium, with an energy gap of 0.928 eV and changing from 0.532 eV to 1.233 eV after applying the biaxial strain, as determined by the Perdew-Burke-Ernzerhof (PBE) method. The results indicate that the Janus HfClBr monolayer has a competitive advantage over other materials for use in solar cells and energy storage devices due to its unique optical and electrical characteristics. Furthermore, our analysis showed that the optical and electrical characteristics of the Janus HfClBr monolayer are significantly impacted by biaxial strain, with the ability to absorb light in both the visible and ultraviolet spectral regions. Additionally, the first optical gap of the Janus HfClBr monolayer is found to be shiftable under the biaxial strain, suggesting potential applications in nano-electronics, particularly in the field of solar cells.

Natural radioactivity is common in the environment. As well as in geological formations such as soil, rock, air, water and plants. Which required extensive researches in many countries are due to the global interest in exposure to natural radioactivity. Ten different samples of milk collected from Iraqi markets were evaluated for concentration of alpha radioactivity (uranium concentration, effective radium content and radon concentrations) using CR-39. After exposure, the detectors were etched in a (NaOH) solution of normality (6.25 N) at a temperature of 70 °C for 8 hours. The tracks were calculated by the microscope track-counting system. At a rate of 0.171 ppm, uranium concentrations ranged between 0.079 – 0.263 ppm. While, the effective radium content varied from 53.724 - 178.47 mBq/kg with an arithmetic rate of 116.096 mBq/kg. The variation of the radon exhalation values for the mass unit and for the area unit was also observed between 0.406 - 1.349 mBq/kg.h and 3.076 -10.217 mBq/m 2.h, at a mean rate of 0.943 mBq/kg.h and 6.646 mBq/m2.h, respectively. The average of annual average internal effective dose (AAIED) due to ingestion of 222Rn in milk samples in children and adults has been found 0.60 nSv/y and 0.2 nSv/y respectively, there are excellent correlation between radium concentrations and radon exhalation rate and uranium concentration(R2=1). Thus, the results of this study do not constitute a health hazard to the lives of people because they are within the limits allowed internationally.

Dye-sensitized solar cells (DSCs) remain an interesting photovoltaic concept, although recent times have seen their envisioned broad-scale applications being replaced with more niche ones. Nevertheless, as a key component of DSCs, titanium(IV) oxide (TiO2) must be produced in a large volume, low cost, and highly reproducible manner. Degussa P25 remains a benchmark TiO2 product, addressing the first two of the above points very well. Post-treatment processes that may also be carried out on a large scale give some hope to addressing the reproducibility issue. This paper builds on our previous works wherein mixed-phase P25 (anatase + rutile + amorphous TiO2) was converted into an amorphous free form by selectively dissolving and recrystallizing the amorphous component. Here we investigated the performance of metal-free organic dye (D149)-based DSCs with three different TiO2 films: (1) as-received P25 (TiO2-P25), (2) amorphous-free P25 (TiO2-HP25), and (3) anatase nanoparticles obtained from Dyesol (TiO2-DSL). DSCs based on TiO2-HP25 showed comparable performance (5.8 ± 0.2% PCE) to DSCs based on the TiO2-DSL (5.8 ± 0.4% PCE) and substantially higher than for devices based on the as-obtained P25 nanoparticles (3.9 ± 0.4% PCE). The enhancement resulting from the post-processing of P25 derives from simultaneous increases in photo-current density (Jsc), open-circuit voltage (VOC), and the fill factor (FF), due to enhancing the dye-loading capability and the charge-transport efficiency (suppressing the electron recombination) as a result of the removal of amorphous barriers and associated defect states. This is in line with enhancing DSC performance based on the organometallic N719 dye we reported previously. However, the photoanode material based on abundant P25 TiO2 sensitized with high-extinction-coefficient organic D149 dye can be adopted as a cost-effective DSC as an alternative to relatively high-cost DSCs based on the commercial anatase TiO2 sensitized with organometallic N719 dye.

In this work we investigate the effect of bending defect on the electronic and structural properties of the (3,3), (4,4), (5,0) and (6,0) single-wall carbon nanotubes (SWCNTs) using density functional theory (DFT) within Becke three parameter Lee–Yang–Parr (B3LYP) functional using 6-31 basis set. Our result revealed that as the bending angle increases, the deformation of atomic structure of the tube increases, particularly in the centralized zone of the tube. The obtained outcomes revealed that the bandgap fluctuates with the bending angle of CNTs and the cohesive energy, the highest occupied (EHOMO) and the lowest unoccupied molecular orbitals energies (ELUMO) decrease (in magnitude) as the CNTs bending increases. On the other hand, the electron affinity and the ionization potential increases with the bending angle of CNTs, while the Fermi energy decreases with the bending angle of CNTs, with a fluctuation of Fermi energy with the bending for (4,4) tube. Finally, in the presence of bending deformation, the highest number of density of states in the valence and conduction bands decrease with increasing the bending angle of CNTs.