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Öğe Investigating physical existence of charged stellar models(Elsevier B.V., 2024) Demir, Emre; Naseer, Tayyab; Ashraf, Asifa; Güdekli, ErtanThis study aims at the detailed exploration of the internal structure of various anisotropic star configurations interacting with an electromagnetic field within the framework of f(R,T,Q) theory of gravity. We, specifically, consider a standard form of this theory in this regard, represented by a linear function of the Ricci scalar and the factor Q. Our analysis adopts a spherically symmetric, charged metric to describe the internal structure of dense quark models and proceeds to derive the field equations which correspond to the considered scenario. These equations are subsequently solved utilizing the particular metric potentials as well as the bag model. We then adopt the empirical data, specifically the radii and masses, from two quark stars including SMC X-4 and SAX J 1808.4-3658 to investigate the impact of charge and modified correction terms on their physical properties. Furthermore, we assess the physical relevance of the obtained model graphically by varying the modified model parameter. Our findings indicate that the developed models exhibit consistent stability within the modified framework across every parametric choice. © 2024Öğe Alternative gamma-ray shielding material: Ternary composite including polyester resin/barite/molybdenum(Korean nuclear society, 2025) Gürel Özdemir, Hatice; Kacal, M.R.; Akman, F.; Polat, H.In the present study, ternary composites containing different proportions of barite and molybdenum and using unsaturated polyester resin as binder were produced. The gamma ray shielding characteristics of these ternary composites were investigated by experimental, theoretical and simulation processes to obtain reliable results. Herewith, RPE, μ, μ/ρ, HVL, TVL, MFP and Zeff parameters for the prepared composites have been revealed. The experimental process was performed in the gamma-ray energy range of 276.4–1332.5 keV with the help of HPGe detector. In the theoretical and simulation studies carried out at the same gamma-ray energies, WinXCOM and GEANT4 were used, respectively. Data produced by three different methods were compared and it was seen that there was agreement between them. The μ values of the coded as BaMo50 composite are 0.4935,0.4464, 0.3824, 0.3586, 0.2908, 0.2478, 0.1799, 0.1721 and 0.1682 cm−1, respectively at 276.4, 302.9, 356.0, 383.9, 511.0, 661.7, 1173.2, 1274.5 and 1332.5 keV. It has been observed that the values of RPE, μ/ρ, μ and Zeff parameters decrease with increasing gamma-ray energy and the opposite trend was observed for the HVL, TVL, and MFP parameters. The composite with the highest gamma-ray shielding capacity among all prepared ternary composites is the one coded as BaMo50.Öğe Minimally deformed anisotropic version of tolman-finch-skea stellar model in enstein-gauss-bonnet gravity(Institute of physics, 2025) Azmat, Hina; Khalid, Rafia; Zubair, M.; Demir, Emre; Gudekli, ErtanIn this article, a well-known anisotropic solution, the Tolman-Finch-Skea (TFS) solution, is studied using the gravitational decoupling approach within the framework of 4D Einstein-Gauss-Bonnet (EGB) gravity. The radial metric potential is modified linearly through the minimal geometric deformation approach, while the temporal component of the metric remains unchanged. The system of EGB field equations is decomposed into two distinct sets of field equations: one corresponding to the standard energy-momentum tensor and the other associated with an external gravitational source. The first system is solved using the aforementioned known solution, while the second is closed by imposing the mimic constraint on pressure. Moreover, the junction conditions at the inner and outer surfaces of the stellar object are examined, considering the Boulware-Deser 4D space-time as the external geometry. The physical properties of the stellar model are analyzed using parameters such as energy conditions, causality conditions, compactness, and redshift.
