Fayoum University

Graphene nanomeshes (GNMs) are porous structures that have attracted theor. and exptl. interest over the past decade.Pores of pristine graphene nanomeshes must be passivated by some species (X) to give chem. stable structures (X-GNM).Here, we consider semiconducting GNMs passivated with H, N, and O.We study substitutional implantation of X-GNM with transition metal elements M (M=Sc, Ti, V, Mn, Co, Ni, Cu, Zn), taking into account various doping locations from the center of the pore (P1, P2, P3, P4 and P5 located at 11.47 Å, 10.03 Å, 7.34 Å, 5.57 Å, and 5.98 Å, resp.).We seek to understand how altering the position of the dopant can influence the electronic and magnetic properties of GNM using d. functional theory.The pore induces new symmetries compared to the parent graphene structure, requiring the consideration of various doping positions in the X-GNM unit cell.The doped H-GNM structures remain planar, whereas the M atoms in the (N, O)-GNM structures protrude from the plane.The M-(N, O)-GNM systems generally demonstrated stability greater than that of the M-H-GNM, with Co-H-, Ti-(N, O)-GNMs being the most stable structures.We find that the electronic properties and magnetization of the M-X-GNM are M- and X-dependent.Structures can be semiconductors, diluted magnetic semiconductors (DMSC), and metals.Notably, we find that the Ti-X-, the Ni-(N, O)-, and the Zn-N-GNMs are semiconductors, irresp. of the doping location.The (Mn, Co)-(N, O)-, V-(H, O)-, and Cu-N-GNMs are DMSCs, while the (Sc, Co, Cu)-H- and Cu-O-GNMs are metals.The V-N-GNM at position P2 and Co-O-GNM at position P4 are half-metallic systems, and can thus be used in spintronic applications.Our results can be valuable for designing graphene-based semiconductor and spintronic devices.

The thyroid gland is an essential endocrine organ that regulates the body's metabolic rate, helps maintain the body's weight, and supports the development of various body organs. Our research is a novel effort to examine the histomorphometric features of the thyroid gland and its relationship with the bone formation of three post-hatching development age stages of Baladi chickens: juvenile (fourteen days old), immature (two months), and mature (six months). This study employs histology, histochemistry, and analysis of thyroid hormone levels. Thyroid glands and femurs of thirty male, healthy chickens of three different post-hatching development ages were collected. The results indicated that the thyroid gland of fourteen-day-old chicks primarily consisted of a single-layer capsule and small to medium inactive follicles. As the chickens aged, the capsule developed into two layers, and there was an increase in large and active follicles. In the thyroid gland at six months, the active follicles were lined with cuboidal cells featuring vacuolated cytoplasm. The colloid (hormonal secretion of follicles) showed a pale acidophilic reaction in younger birds, which deepened with age. Thyroid hormone levels increase with age as a result of heightened gland activity. The histological changes of the femur correlate closely with the development of the thyroid gland across different ages. Future research aimed at gaining a deeper understanding of the intricate histophysiology and histopathology of the digestive system in zoo birds would benefit from this knowledge.

A novel Zinc-Tellurite borosilicate (ZTBS) glass system was successfully synthesized via the melt quench process. Its chemical composition is represented by the formula (44SiO₂-25B₂O₃-18Na₂O-6CaO-1ZrO₂-(6-x)ZnO-xTeO₂), and its weight fraction (x = 0, 2, 4, 6 wt%). The shielding properties, there is perfect agreement between the results of the theoretical calculation of the mass attenuation coefficient using the Phy-X/PSD and the compatible values derived from the WinXCom databases. Further, several photon shielding parameters were computed in the 15 keV-15 MeV energy range, including the mass attenuation coefficient (MAC), half value layer (HVL), mean free path (MFP), exposure buildup factor (EBF), and effective atomic number (Z_eff). The preferred sample for gamma ray shielding is the sample with the highest TeO₂ concentration (ZTBS3), according to the results. ZTBS3 glass samples have greater MAC and HVL values than other published borosilicate glasses at 662.61 k eV photon energy which reaches 0.07626 cm^-2/g and 3.429 cm respectively. Also, LAC values is higher in the sample with the largest concentration of TeO₂. Furthermore, the computed HVL and MFP were lower than those of regular concrete. The shielding results indicate that the newly developed transparent ZTBS glasses compositions that are lightweight and have good shielding properties that may be suitable in shielding applications. Depending on the application, the ratio of TeO₂ additive should be balanced between improved shielding and glass stability features.