Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Alım, Bünyamin(2)
- Alaylar, Burak(1)
- Alim, B.(1)
- Alsaif, Norah A.M.(1)
- Alım, B.(1)
- Arslan, İbrahim(1)
- Aygün, Bünyamin(1)
- Bayram, Sinan(1)
- Demir, Lütfü(1)
- Dikici, B.(1)
- Dikici, Burak(1)
- Guler, O.(1)
- Guler, Omer(1)
- Guler, S.H.(1)
- Gökçe, H.S.(1)
- Güllüce, Medine(1)
- Han, İbrahim(1)
- Karabulut, Abdulhalik(1)
- Karadayi, Mehmet(1)
- Kök, S.(1)
- Lampke, T.(1)
- Rammah, Y.S.(1)
- Sakar, E.(1)
- Sakar, Erdem(1)
- Say, Yakup(1)
- Singh, V.P.(1)
- Türetken, M.S.(1)
- Öksüzer, N.(1)
- Özpolat, Ö.F.(1)
- Özpolat, Özgür Fırat(1)
- Şakar, E.(1)
- Şakar, Erdem(1)
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ1Effect of oxidation on radiation shielding capacity of ZrNbTaMoW Refractory High Entropy Alloys (RHEA) for nuclear reactor applications: Experimental and theoretical assessment
Sakar, E.; Guler, O.; Alim, B.; Guler, S.H.; Dikici, B.; Lampke, T.
This study presents the production and comprehensive assessment of a Refractory High Entropy Alloy (RHEA) with a ZrNbTaMoW composition for possible usage nuclear reactor applications. The alloy was synthesized using the mechanical alloying (MA) method, and its radiation properties were examined. Elemental powders of Zr, Nb, Ta, Mo, and W were utilized in equimolar quantities during the 120-hour MA process, conducted under a high-purity Ar atmosphere to prevent oxidation. The obtained HEA was then subjected to a mechano-thermal process to transform it into Refractory High-Entropy Oxide (RHEO) for comparing their radiation-shielding performance under oxide conditions. The characterization of the produced alloys through X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron dispersive spectroscopy (EDS). The photon shielding parameters of the alloys were experimentally obtained for various energies emitted from a 133Ba radioactive source, employing a Canberra UltraLEGe semiconductor detector. Furthermore, theoretical calculations were performed to validate the experimental data and to evaluate the alloys' photon shielding capabilities comprehensively. For this purpose, Phy-X/PSD software was employed to determine mass attenuation coefficients, half-value layer, effective atomic number, and effective electron density. Fast neutron absorption capabilities were determined through the calculation of average absorption cross-sections in the 2–12 MeV energy range. The results showed that the oxidation process significantly diminished the photon absorption capacity of RHEA.
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İncele - MakaleAçık Erişim2023Scopus SJRQ1A comprehensive study on structural properties, photon and particle attenuation competence of CoNiFeCr-Ti/Al high entropy alloys (HEAs)
Sakar, Erdem; Guler, Omer; Alım, Bünyamin; Say, Yakup; Dikici, Burak
It is well known that high entropy alloys (HEAs) have a wide range of potential applications as radiation shielding due to their superior properties. The CoNiFeCr-Ti/Al compositions were chosen for their low cost as HEA in this study. The HEAs were successfully produced using the mechanical alloying (MA) method with equimolar CoNiFeCr, CoNiFeCrAl, and CoNiFeCrTi compositions. The production and structural properties of the alloys were investigated in detail. Besides, the photon and particle radiation shielding properties of the HEAs were calculated with the help of Phy-X/PSD, SRIM (10 keV-20 MeV), and ESTAR (10 keV-20 MeV) programs. The photon-matter interaction parameters were calculated in both specific photon energies emitted from 241Am, 133Ba, 109Cd, 60Co, 137Cs, 131I, and 22Na nuclides and a continuous energy range of 15 keV-15 MeV. The characterization of the alloys was investigated by using X-ray diffraction (XRD) and scanning electron microscopes (SEM) attached to an energy dispersive spectroscopy (EDX). It was found that the HEAs have a highly amorphous structure due to the selected production method. The crystal size of the alloys was calculated as 70, 35, and 20 nm for CoNiFeCr, CoNiFeCrAl, and CoNiFeCrTi, respectively. In terms of shielding properties, it has been determined that the produced HEAs have better shielding characteristics for photon and particle radiations than standard shielding concretes. In addition, the results demonstrated that CoNiFeCr alloy, which has the best shielding ability among the HEA alloys, can be used as a shielding material application requiring photon, electron, proton, alpha, and neutron radiations.
AtıfScopus30WoS32OpenAlex32İncele - MakaleAçık Erişim2023Scopus SJRQ2Determination of toxicity and radioprotective properties of bacterial and fungal eumelanin pigments
Bayram, Sinan; Aygün, Bünyamin; Karadayi, Mehmet; Alaylar, Burak; Güllüce, Medine; Karabulut, Abdulhalik
Purpose: Determination of the protective property of melanin, an organic polymer class consisting of phenolic and/or indolic compounds isolated from bacteria and fungi, against fast neutron radiation. To show that these melanin samples, which also have antioxidant and metal chelating properties, can be used as an active ingredient for a drug to be developed against neutrons used in nuclear research and medicine. Materials and methods: Bacterial and fungal media were prepared, and melanin pigments were produced and isolated. For molecular characterization of pigments, bacterial genomic DNA extraction, 16S rDNA gene amplification processes, and fungal genomic DNA extraction, ITS1, and ITS4 Gene Regions amplification were performed. The DEL assay was implemented to determine the genotoxicity properties of bacterial and fungal melanin pigments. Samples were prepared in a pad measuring 10 ml volume (60 × 15 mm) at a concentration of 0.2–1 microgram in 1% agarose gel for radiation-absorbed dose measurements. Absorption measurements were made using 241Am-Be fast neutron source and Canberra brand NP series BF3 gaseous detector to determine the neutron radiation absorption capacity of all samples. The results obtained to determine the absorption degrees of melanin samples were compared with paraffin and normal concrete, which are widely used in neutron radiation shielding studies. Results: Melanin pigments were obtained using different bacteria and fungi strains. Afterwards, the fast neutron radiation absorption capacity of these purified pigments were determined. Compared to reference samples, these pigments were found to have slightly lower radiation absorbing ability. In addition to these experiments, cytotoxicity tests were carried out using the Yeast DEL assay technique to evaluate the potential for use of these organic pigments in fields such as medicine and pharmacology. According to the results obtained from the tests, it was determined that these melanin samples did not have any toxic effects. Conclusion: It was determined that these melanin samples have the potential to be used as a radioprotective drug active substance to protect the tissues and cells of people exposed to neutron radiation after a nuclear accident or nuclear war. Giving a drug that will be developed by using these active ingredients before or after people are exposed to a radiation environment can provide great benefits.
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İncele - MakaleAçık Erişim2023Scopus SJRQ2Effect of elevated temperature on radiation shielding properties of cement and geopolymer mortars including barite aggregate and colemanite powder
Kök, S.; Türetken, M.S.; Öksüzer, N.; Gökçe, H.S.
This study aims to investigate the radiation shielding efficiency of cement and geopolymer-based mortars after exposure to elevated temperatures which may happen during the activation process of nuclear reactors. To contribute to the shielding properties, these binders were modified with the substitution of colemanite powder (5 and 10%), and barite aggregate was used to be an alternative to silica sand, as well. The produced specimens were exposed to 300 and 500 °C. While the colemanite powder resulted in significant retardation of setting time up to 183% for cement-based series, a set accelerator effect reaching 67% was found in the geopolymer series. Unlike expectation, the losses in mechanical and shielding properties have become more pronounced in geopolymer mortars at the applied temperatures. In particular, a significant increase reaching 28% in compressive strength of cement series was found after 300 °C exposure. It was noted that cement series with reaching a linear attenuation coefficient of 0.162 cm−1 presented more effective shielding against gamma rays when compared to that (0.134 cm−1) of geopolymers. To moderate thermal neutrons, geopolymer series reaching a linear attenuation factor of 2.799 cm−1, were found to be a more promising alternative according to cement series reaching 2.140 cm−1.
AtıfScopus30WoS27İncele - MakaleAçık Erişim2022Scopus SJRQ2Precipitation-hardening stainless steels: Potential use radiation shielding materials
Alım, Bünyamin; Özpolat, Özgür Fırat; Şakar, Erdem; Han, İbrahim; Arslan, İbrahim; Singh, V.P.; Demir, Lütfü
In this study, it was focused on the research of new materials with high attenuation efficiency that can be used as radiation shielding material due to the incapability of conventional materials. In accordance with this purpose, the radiation shielding capabilities of four different precipitation-hardening stainless steels (PH-SSs), which are symbolized 15-5PH, 15-7PH, 17-4PH and 17-7PH, were determined both experimentally and theoretically in a wide range of radiation energy. For experimental measurements, two different detectors (Si(Li) and Na(Tl)) and twenty-three different photon energies (from 22.1 to 1332.5 keV) emitted from seven different radionuclides were used in narrow-beam transmission geometry. Phy-X/PSD software were used for theoretical calculations. The theoretically calculated parameters were determined both in the photon energies emitted by the radionuclides used in the experiment and in the continuous energy range of 0.015–15 MeV. Furthermore, in order to make a remarkable assessment of the integration of PH-SSs to nuclear energy applications, the all results obtained have been compared with the corresponding values of Fe-based steel concretes (steel-scrap (SS) and steel-magnetite (SM)), which are widely used as conventional shield materials in nuclear power plants. Moreover, in order to choose the best material to be used in nuclear applications among the PH-SSs, the results were evaluated comparatively in terms of both the characteristics of the materials and the magnitude of the radiation shielding parameters. Consequently, it was concluded that the material with the best radiation shielding performance among the examined PH-SSs was 15-7PH and the radiation shielding performance ranking was generally in the form of 15-7PH ≥ 15-5PH > 17-4PH > 17-7PH > SM > SS. Due to both high attenuation efficiency and superior properties for radiation shielding, it was determined that the PH-SSs can be used as new shielding materials in nuclear applications.
AtıfScopus25WoS25OpenAlex27İncele - MakaleYalnız künye2022Scopus SJRQ2Evaluation of γ-rays and neutron shielding parameters of high dense bismo-boro-tellurite glasses: Comparative study
Şakar, E.; Özpolat, Ö.F.; Alım, B.; Alsaif, Norah A.M.; Rammah, Y.S.
The main high energy radiation-matter interaction parameters of the 30B2O3-(70-x)TeO2-xBi2O3, where x = 40, 50, 60 and 70 mol% (BTB) glasses have been studied in the wide energy range. The theoretical calculations were made for some special X and γ-ray energies emitted from Fe (55), Am (241), Cs (137) and Co (60) radioactive sources for photon energies in the range of 15 keV - 15 MeV. All evaluated radiation shielding parameters were compared with some selected concretes (Ordinary concrete (OC), Hematite-Serpenite (HS) and Basalt-Magnetide (BM)), and glasses (Te and Pb based). The BTB- glasses have higher mass attenuation coefficient (MAC) values than other glasses (Te and Pb based) and concretes (OC, HS, and BM). The half value layer (HVL) of the investigated BTB-glasses has the following trend: OC > HS > BM > Te-Glass > Pb-glass > BTB40 > BTB50 > BTB60 > BTB70. In terms of mean free path (MFP), the BTB70 coded glass has the lowest MFP values due to the highest Bi2O3 content. In terms of the Zeff values of BTB coded glasses vary between 70 and 75 at the lowest energy level. The effective atomic number (Zeff) values in this energy region were 48.974 and 63.102 for Te and Pb glasses, respectively, and 13,339, 15.520 and 15.894 for OC, HS and BM concretes. The BTB-coded glasses have lower exposure buildup factor (EBF) than all other glass and concrete up to 3 MeV photon energies. The energy absorption buildup factor (EABF) values range from 1 to 4.2 for all samples at 1 MFP and at 40 MFP values, it reaches 108 for BTB coded glasses and 1010 for Te-based glass. Results confirmed that BTB- glasses, especially BTB70 glass sample can be used in applications requiring radiation safety.
AtıfScopus17WoS16OpenAlex17İncele