We utilised first-principles computations based on density functional theory to investigate the optical and electronic properties of bilayer CdS before and after the adsorption of gas molecules. Initially, we examined four candidate adsorption sites to determine the best site for adsorbing CO, CO₂, SO₂, H₂S, and SO. In order to achieve the optimal adsorption configurations, we analysed the adsorption energy, distance, and total charge. Our findings reveal that the CdS bilayer forms a unique connection between the O and Cd atoms, as well as the S and Cd atoms, which renders it sensitive to SO₂, H₂S, and SO through chemical adsorption, and CO and CO₂ through strong physical adsorption. The adsorption of gas molecules enhances the optical properties of the CdS bilayer. Consequently, the CdS bilayer proves to be a highly efficient gas sensor for SO₂, H₂S, and SO gases.

Catalysis involving Cu–In nanoparticles represents an exciting area of technological advancement. However, our fundamental grasp of the mechanisms governing mixing within Cu–In clusters at the sub-nanometer scale and their gas-phase physicochemical properties remains inadequate. We have determined the global minima for gas-phase Cu–In clusters containing 3 to 10 atoms using the Mexican Enhanced Genetic Algorithm in conjunction with density functional theory. Simulations were also conducted for Cu and In atoms and their dimers at the same theoretical level. Comparative analyses were performed between mixed Cu–In systems and their pure counterparts, with pure Cu and In clusters being modeled up to 13 atoms. The findings indicate a 2D–3D transition for pure Cu clusters at 7 atoms, while for pure In clusters, this transition occurs at 5 atoms. For Cu–In nanoalloys, both cluster size and doping have been found to significantly and non-linearly impact cluster structures. Stability assessments, including binding energies, second differences in energy, and mixing energies, were used to evaluate the energetics, structures, and segregation tendencies of sub-nanometer Cu–In clusters. The most stable composition, as indicated by mixing energies, is achieved when the Cu to In ratio is equal or nearly equal. The HSE06 spin-projected band structure reveals that In₄Cu₁ displays magnetic properties akin to monometallic In₅. Conversely, the spin-projected band structure and partial density of states (PDOS) analysis for bimetallic Cu₇In₁ show that the cluster is non-magnetic. Analysis of the topological parameters of Cu–Cu, In–In, and Cu–In bonds in bimetallic clusters, using the Quantum Theory of Atoms in Molecules (QTAIMs), indicates that these interactions are not purely closed-shell but involve significant covalent contributions.

Developing effective methods and materials for hydrogen (H ₂ ) storage in hydrogen fuel cell vehicles is essential to reduce reliance on fossil fuels in the transportation sector. Carbon‐based materials have been proposed as promising candidates for H ₂ storage. In this article, van der Waals‐corrected density functional theory calculations are employed to explore the potential of ψ‐graphene monolayers doped with transition metals (Sc, Ti, and V) as promising H ₂ storage materials. Metal dopants strongly bind with ψ‐graphene with binding energies of 4.38, 4.11, and 2.44 eV for Sc, Ti, and V, respectively. Additionally, the diffusion energy barriers of (0.5, 0.51, and 0.24 eV) for Sc, Ti, and V, respectively, on the ψ‐graphene surface significantly reduce the calculated metal agglomeration probability when Sc, Ti, and V are displaced from the Hp site to the Ha site. Metal decorated ψ‐graphene can bind up to six H ₂ molecules, with average adsorption energies of 0.31, 0.37, and 0.41 eV per H ₂ molecule for Sc, Ti, and V, respectively. The calculated H ₂ storage capacities are 5.97%, 5.89%, and 5.80% for decorated ψ‐graphene systems with Sc, Ti, and V, respectively. These calculated properties align well with the U.S. Department of Energy's criteria for reversible H ₂ storage in fuel cell vehicles. Thermodynamic analysis indicates that Sc@ψ‐graphene and Ti@ψ‐graphene offer the most favorable hydrogen storage performance under realistic operating conditions (30 atm and 25 °C for adsorption; 3 atm and 100 °C for desorption). AIMD simulations conducted at 400 K demonstrate the excellent thermal stability of X@ψ‐graphene (X = Sc, Ti, V) complexes, even at elevated doping concentrations. Throughout the 5 ps simulation, regulated by a Nosé–Hoover thermostat, the systems preserved their structural integrity, highlighting their resilience to thermal fluctuations and suitability for high‐temperature applications. Consequently, ψ‐graphene doped with Sc, Ti, or V emerges as an exceptional material for reversible H ₂ storage.

This work studies the activity concentration of natural radioactivity in 20 different types of rice, including imported rice and that produced locally. The rice samples were collected from markets and farms in Iraq, and then a natural radioactivity investigation was done in the environmental laboratory of the Kufa University, using gamma-ray spectrometer systems. The research focused on measuring the activity concentration of natural radioactivity (238U, 232Th, and 40K) to determine the level of the radium equivalent activity, internal hazard indices, and annual effective dose. The results show that all these parameters are within the permissible limits and that radioactivity is present in almost all foodstuffs at levels ranging from 40 to 600 Bq/kg of food. Radioactivity in foodstuffs is attributed to a natural source, potassium-40, and to artificial sources, which include industrial radioactivity, weapons testing, and accidents involving radioactivity. In this article, radionuclides have been i...