Yazar "Tekin, H.O." seçeneğine göre listele

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    Er 2 O 3 effects on photon and neutron shielding properties of TeO 2 -Li 2 O-ZnO-Nb 2 O 5 glass system
    (Elsevier B.V., 2019) Ağar, Osman; Kavaz, E.; Altunsoy Güçlü, E. E.; Kılıçoğlu, O.; Tekin, H.O.; Sayyed, M.I.; Ergüzel, T.T.
    In this study, a series of 75TeO 2 -5Li 2 O-10ZnO-(10-x)Nb 2 O 5 -(x)Er 2 O 3 (where x = 0, 0.5, 1.0, 1.5, 2.0 and 2.8 mol%) glasses have been surveyed in terms of photon and neutron shielding characteristics. For this aim, 3 × 3 inch NaI(Tl) detector has been simulated in order to detect photons. Afterwards, the mass attenuation coefficients (?/?) and some shielding quantities such as half-value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Z eff ), effective electron density (N el ), equivalent atomic number (Zeq) and exposure build-up factor (EBF) have been calculated. The obtained MCNPX results of all the glasses have been compared and approved with those of XCOM program. Also, their gamma ray buildup factors have been determined in a wide energy range of 0.02–20 MeV for penetration depths up to 15 mfp. Moreover, neutron attenuation abilities of glasses have been evaluated by estimating neutron total effective removal cross section. The results showed that Er 2 O 3 partial replacement of Nb 2 O 5 in 75TeO 2 -5Li 2 O-10ZnO-(10- x)Nb 2 O 5 -(x)Er 2 O 3 glass system enhances photon and neutron attenuation characteristics. It can be deduced that obtained results from the present investigation can be useful to understanding of influence of Er 2 O 3 on nuclear radiation shielding properties of tellurite glasses.
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    The investigation of gamma-ray and neutron shielding parameters of Na 2 O-CaO-P 2 O 5 -SiO 2 bioactive glasses using MCNPX code
    (Elsevier B.V., 2019) Tekin, H.O.; Kılıçoğlu, O.; Kavaz, E.; Altunsoy Güçlü, E. E.; Almatari, M.; Ağar, Osman; Sayyed, M.I.
    Bioactive glasses are silicate glasses with sodium, calcium and phosphorus in its composition used to fulfill or support the functions of living tissues in the human body. The superiority of physical and mechanical properties of the bioactive glasses leads to the opportunity to use for radiation protection. From this point of view, radiation absorption parameters of nine bioactive glasses were reported in the present research. The mass attenuation coefficient (?/?) for the selected bioactive glasses was calculated using MCNPX simulation code in the photon energy range 0.02–20 MeV and the results were compared with XCOM data. The values of ?/? calculated in two methods were found to support each other. Other vital parameters like half and tenth value layer (HVL and TVL), mean free path (MFP) and effective atomic number (Z eff ) for the selected bioactive glasses were also evaluated by utilizing the ?/?. ICSW9 glass with more phosphate and sodium contents possess the lowest MFP, HVL and TVL values while has the highest Z eff values among the bioactive glasses under study. To evaluate the neutron protection performance of investigated bioactive glasses, effective removal cross-section values (?R) have been determined. The results showed that ICSW9 has also superior neutron attenuation properties. Additionally, exposure buildup factor (EBF) values were found with G-P fitting approach depending on the energy and penetration depths. The bioactive glasses with further equivalent atomic number possesses the minimum value of EBF. © 2019 The Authors
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    The Mass stopping power / projected range and nuclear shielding behaviors of barium bismuth borate glasses and influence of cerium oxide
    (Elsevier Ltd, 2019) Kavaz, E.; Tekin, H.O.; Ağar, Osman; Altunsoy Güçlü, E. E.; Kılıçoğlu, O.; Kamışlıoğlu, M.; Abuzaid, M.M.
    This paper aims to evaluate not only photon and neutron but also proton and alpha shielding effectiveness of barium bismuth borate glasses doped by CeO2. The mass attenuation coefficients (?/?) of these glasses have been computed utilizing MCNPX (2.6.0) code in a wide energy range of 0.02–20 MeV and compared with the results of WinXCOM software. Afterwards, some photon attenuation parameters such as half-value layer, (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic number (Zeff), effective electron density (Nel), photon transmission factors (TF) and neutron effective removal cross-sections (?R) for the cerium oxide substituted barium bismuth borate glasses have been estimated. Using G-P fitting method, exposure buildup factor (EBF) values have been found over the energy range 0.015–15 MeV up to 40 mfp. In addition, Mass stopping power (MSP) and projected range (PR) values have been calculated for proton particles (H1) and alpha particles (He+2). The results exhibit that the density of the glass can be related to the photon and neutron shielding. A10 glass has the highest ?R values whereas the lowest TF values in gamma and neutron radiation have been observed for A1 sample. A1 and U glasses possess the highest values of Zeff as well as the smallest values of EBF. It can be concluded that A1 and A10 glasses are alternative materials with terms of photon and neutron attenuation, respectively.
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    Physical, structural, and radiation shielding properties of B 2 O 3 –MgO–K 2 O–Sm 2 O 3 glass network modified with TeO 2
    (Elsevier Ltd, 2019) Divina, R.; Marimuthu, K.; Sayyed, M.I.; Tekin, H.O.; Ağar, Osman
    A new series of Sm 3+ doped Telluroborate glasses with varying TeO 2 content have been prepared following the melt quenching technique. The physical properties like density, refractive index, average molecular weight, molar volume, optical dielectric constant, and metallization criterion were calculated. Structural properties like boron-boron separation (<d B–B >), molar volume of oxygen (V o ), oxygen packing density (OPD), average coordination number (m), bond density (n b ), Poisson ratio (µ cal ), optical electronegativity (? opt ), basicity (? th ), two photon absorption (TPA) coefficient (?), ionic character (I c ), and covalent character (C c ) were calculated. In addition to that, optical bandgap and urbach energy (?E) values of the titled glasses have been calculated from Tauc's plot using the absorption spectra. It is observed that boron-boron separation (<d B–B >) and OPD increases with the decrease in molar volume of oxygen (V o ). Also, the increasing density and refractive index values with the progressive decrease of molar volume with increasing TeO 2 content implies the formation of bridging oxygen (BO) along with nonbridging oxygen (NBO), which is later proved by the Poisson ratio values and basicity values. Further, ionic nature of the Sm 3+ doped telluroborate glasses are identified from the measured optical basicity (? th ), covalent, and ionic characteristic factors. The observed variations in the optical electronegativity, basicity, metallization criterion, and optical bandgap energy (E g ) values have been discussed in terms of the structural changes that take place due to the addition of TeO 2 into the B 2 O 3 network. The gamma photon shielding properties for the prepared samples were studied using MCNPX code in the energy range of 0.356–1.33 MeV. The obtained mass attenuation coefficient exhibit an increasing trend as the TeO 2 content vary from 0 to 40 mol%, especially at the energy 0.356 MeV. Of all the glasses, 4TBS glass sample shows lowest half-value layer value. The study confirms that the replacement of B 2 O 3 by TeO 2 enhances the capability of the prepared glass samples to reduce the gamma photons.
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    Shielding behaviour of (20 + x) Bi2O3 – 20BaO–10Na2O–10MgO–(40-x) B2O3: An experimental and Monte Carlo study
    (Elsevier B.V., 2020) Sayyed, M.I.; Ağar, Osman; Kumar, A.; Tekin, H.O.; Gaikwad, D.K.; Obaid, S.S.
    In this study, (20 + x) Bi2O3 – 20BaO – 10Na2O – 10MgO – (40-x) B2O3 (where x = 0, 5, 10, 15 and 20 mol%) are fabricated by the melt quenching method. The various radiation shielding parameters for the present glasses are determined experimentally using the gamma spectrometric system and Monte Carlo N-Particle Transport Code System-extended (MCNPX). The mass attenuation coefficient and the effective atomic number are found to be dependent on the photon energy, the glass composition and the concentration of Bi2O3. The results reveal that Bi40B20 sample with the maximum amount of Bi2O3 has the lowest MFP and HVL values among all the other samples as well as the other standard shielding glasses. The radiation shielding efficiency also is calculated and the result shows that the present glass samples can highly attenuate low energetic gamma photons, while the capability to attenuate the incident photons is minimized with increasing the photon energy.
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    Shielding features, to non-ionizing and ionizing photons, of FeCr-based composites
    (Elsevier Ltd, 2021) Akman, Ferdi; Özkan, İlkan; Kaçal, Mustafa Recep; Polat, Hasan; Issa, S.A.M.; Tekin, H.O.; Ağar, Osman
    This paper has been focused on the a detail study on non-ionizing and ionizing electromagnetic (EM) shielding features and build-up factors of reinforced with ferrochrome (FeCr) composites. The non-inozing electromagnetic shielding performance quantities of composites have been determined in the frequency range between 12.4 and 18.0 GHz. Also, the experimental mass attenuation coefficients (MAC) have been estimated using gamma spectrometer and various radioactive point, and compared to those of theoretical and simulation (MCNPX) results. With help of the obtained linear attenuation coefficients, several attenuation quantities, i.e., effective atomic number (Zeff), half value layer (HVL), and mean free path (MFP) have been discussed. In addition, buildup factors (EBF and EABF) values have been estimated utilizing the G-P fitting method. The results showed that composite encoded FeCr(15%) is superior shielding attenuation properties among the investigated samples. © 2020 Elsevier Ltd
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    Simulation of shielding parameters for TeO 2 -WO 3 -GeO 2 glasses using FLUKA code
    (Elsevier B.V., 2019) Sharma, A.; Sayyed, M.I.; Ağar, Osman; Tekin, H.O.
    This paper aimed to report the results on the investigation of photon attenuation parameters for TeO 2 -WO 3 -GeO 2 glasses using FLUKA Monte Carlo code. In order to test the validity of the present code, the computational values of mass attenuation coefficients have been in confirmation with those of both previously published experimental data (MoO 3 -B 2 O 3 -Bi 2 O 3 ) and XCOM database at various energies between 356 and 1330 keV. The relative deviation between FLUKA and experimental data is below 5.19% while the difference between the present code and XCOM database is found to be almost 2%. Therefore, the estimated results are in good agreement to each other and exhibited that FLUKA simulation is an alternative technique in determining the shielding performance of the present glass system. Additionally, mean free path and half-value layer results were calculated and it was concluded that among the selected glasses, TeWGe5 sample has superior shielding effectiveness.