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- MakaleYalnız künye2024Scopus SJRQ1First-ever fusion of high entropy alloy (HEA) with glass: Enhancing of critical properties of zinc-tellurite glass through TiZrNbHfTaOx incorporation
Güler, Ömer; Kilic, G.; Kavaz, E.; Ilik, E.; Guler, Seval Hale; ALMisned, Ghada; Tekin, H.O.
Many oxide additives have historically been used to enhance the radiation shielding properties of glasses, yet the potential of high-entropy oxides (HEOs), which have gained popularity in material science for their unique properties, has not been explored in this context. This study is the first to investigate the radiation shielding capabilities of Zinc-Tellurite glass infused with High Entropy Oxide (HEO), specifically utilizing the novel attributes of a synthesized TiZrNbHfTa. In this study, the nuclear shielding properties of newly fabricated Zinc-Tellurite glasses doped with TiZrNbHfTaOx with a composition (25ZnO·75TeO2)100-x. (TiZrNbHfTaOx)x (x = 0, 1, 2, 3, 4 mol%) were studied. Through the synthesis of a TiZrNbHfTa HEA and its integration into glass structure, we have developed a series of novel materials with enhanced protective properties against both gamma-ray and neutron radiation. Experimental results demonstrate that the HEO-infused glass, particularly the HEC1-4 composition, significantly surpasses traditional shielding materials in neutron attenuation, evidenced by its superior effective neutron removal cross-section. Additionally, the HEC1-4 glass demonstrates improved gamma-ray shielding capabilities, with increased mass attenuation coefficients and decreased half-value layers, indicating a higher capacity for photon interaction and absorption. It can be concluded that the incorporation of High Entropy Alloys into glass matrices not only opens a new frontier in radiation shielding materials but also provides a versatile and effective solution with considerable potential for enhancing safety measures in radiation-prone environments.
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İncele - MakaleYalnız künye2024Scopus SJRQ2A first-time fusion of TiNbWMoZrOx high entropy oxide (HEO) with zinc-tellurite glass: Toward superior physical properties
Kilic, G.; Güler, Ömer; Kavaz, E.; Ilik, E.; Guler, Seval Hale; ALMisned, Ghada; Tekin, H.O.
While numerous oxide additives have traditionally been employed to enhance the radiation shielding capabilities of glasses, the unique attributes of high-entropy oxides (HEOs), a group of materials acclaimed in contemporary material science for their distinctive properties have remained unexamined in this specific area. This novel study explores the enhancement of radiation shielding properties in zinc-tellurite glasses through the integration of TiNbWMoZrOx High Entropy Oxides (HEO). Utilizing advanced synthesis techniques, including mechanical alloying and oxidation, the research successfully incorporates HEOs into glass matrices, aiming to improve gamma-ray and neutron attenuation. Characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirms the uniform distribution and structural integrity of the HEOs within the glasses. The synthesis of glass samples with a base structure suitable for the molar composition of 25ZnO.75TeO2 (mol%) and glass samples doped with TiNbWMoZrOx (HEO) was carried out using the traditional high-temperature melting and annealing method. The outcomes demonstrate a concentration-dependent increase in shielding efficacy, particularly highlighting the superior performance of glasses doped with 4 mol% of TiNbWMoZrOx (HEC2–4), which exhibit significantly enhanced mass attenuation coefficients, lower half-value layers, and higher effective atomic numbers. This indicates the effective role of HEOs in boosting radiation protection capabilities. Comparative analysis with traditional shielding materials showcases the HEC2–4 glasses' competitive advantage, underlining their potential as a versatile shielding solution. It can be concluded that incorporating TiNbWMoZrOx high entropy oxides into zinc-tellurite glasses significantly augments their radiation shielding properties, offering a novel approach for enhancing protection against gamma-ray and neutron in various applications.
AtıfScopus6OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ3Structural, physical, and radiation absorption properties of a significant nuclear power plant component: A comparison between REX-734 and 316L SS austenitic stainless steels
Say, Yakup; Güler, Ömer; Kavaz, Esra; ALMisned, Ghada; Ene, Antoaneta; Tekin, Huseyin Ozan
Austenitic stainless steels (SSs) are commonly used as in-core and surrounding structural materials in today’s industrial BWR and PWR systems. Such adaptable steels have also been the primary materials studied and used in several advanced nuclear reactor technologies, such as fast breeding and magnetic fusion reactors. In this study, some critical material properties, such as structural, physical, and radiation-shielding properties of REX-734 and 316L SS, were experimentally evaluated and compared to those of a number of other alloys. In addition to homogeneous element distribution, both alloys exhibit strong crystal orientation. The REX-734 alloy has a tensile strength of 1,259 MPa, whereas the 316L SS alloy has a tensile strength of 495 MPa. Moreover, nitrogen in the REX-734 alloy formed ultra-hard nitrides with Cr, Nb, and Si and precipitated into the structure and increased the strength. According to our findings, the mass attenuation coefficient values of the 316L SS sample were slightly higher than those of the REX-734 sample at all energies. It can be concluded that the REX-734 sample, with its exceptional strength qualities and excellent radiation attenuation capabilities, may be a viable nuclear power plant material for future investigations.
AtıfScopus7İncele - MakaleAçık Erişim2023Scopus SJRQ1FeCoNiMnCr high-entropy alloys (HEAs): Synthesis, structural, magnetic and nuclear radiation absorption properties
Şimşek, Telem; Kavaz, Esra; Güler, Ömer; Şimşek, Tuncay; Avar, Barış; Aslan, Naim; Almisned, Ghada; Zakaly, Hesham M.H.; Tekin, H.O.
We report the synthesis and structural, magnetic and Radiation shielding properties of High Entropy Alloy (HEA) produced through mechanical alloying method. Using an X-Ray Diffractometer (PanalyticalEmpryan) with CuK radiation at 45 kV and 40 mA, the phase identification starting elements and as-milled powders are identified. Scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX), morphological and microstructural investigations were conducted (FEI Quanta FEG 450). EDX and elemental mapping analyses are conducted to assess the purity and elemental distributions of the synthesized alloys. Using the Quantum Design Physical Characteristics Measurement System (PPMS) with vibrating sample magnetometer (VSM) and a magnetic field of 30 kOe at room temperature, magnetic properties are examined. Using 137Cs radioisotope and mathematical methods, gamma-ray and neutron shielding properties of HEA are investigated in a conventional transmission setup using experimental and theoretical approaches. In the presence of a 3 T applied field, the sample exhibits a low magnetization of 5.30 emu/g at 300 K. Moreover, Ms is raised to 22 emu/g at 10 K owing to decreased thermal effects. The temperature dependence of the magnetization is recorded in the presence of a 1 T applied field. HEA exhibits superior neutron attenuation properties than conventional absorption materials such as B4C, graphite, and water. Our results showed that the synthesized HEA has superiority over other alloys and conventional neutron absorption materials. It can be concluded that the proposed novel HEA might be investigated further in terms of broadening its characterization and clarifying its other crucial properties to extend the scope of the current investigation.
AtıfScopus42OpenAlex47İncele - MakaleYalnız künye2023Scopus SJRQ1Oxides dispersion-strengthened (ODS) FeCoNiCuZn high entropy alloys through different rare earth elements: Synthesis, structural, physical, and experimental radiation transmission properties
Güler, Ömer; Kavaz, E.; Güler, Seval Hale; Almisned, Ghada; Özkul, İskender; Basgoz, Oykum; Tekin, H.O.
The oxide dispersoids within ODS alloys can act as sinks for radiation-induced defects, such as vacancies and dislocation loops, effectively reducing their mobility and preventing their accumulation. This property is crucial for HEAs employed in radiation-intensive environments, such as nuclear reactors. The objective of this research is to examine the impact of rare earth elements (REE) such as Y2O3, Er2O3, Pr2O3, and Sm2O3, on Oxides Dispersion-Strengthened (ODS) FeCoNiCuZn High Entropy Alloys (HEAs). The mechanical alloying technique is employed to produce a high entropy alloy consisting of Fe, Co, Ni, Cu, and Zn in their raw form. Subsequently, the raw alloy powder is enriched with separate amounts of Y2O3, Er2O3, Pr2O3, and Sm2O3. The microstructural analysis of the samples obtained from the mechanical alloying process was performed utilizing the X-ray diffraction (XRD) technique. In addition, scanning electron microscopy (SEM) was employed to analyze the ODS-HEA samples encoded S1, S2, S3, S4, and S5. To investigate the transmission properties of gamma-ray and neutron radiation, experimental studies are carried out using two types of detectors: Ultra High Purity Germanium (HPGe) detector and Canberra NP-100B BF3 gas proportional detector, respectively. The X-ray diffraction (XRD) spectra of samples did not display any observable peaks that could be attributed to the presence of dispersed rare earth element (REE) oxides. The uniform distribution of the metallic constituents that make up the High Entropy Alloy (HEA) is observed in the samples. Additionally, it can be observed that the implementation of the ODS-HEA technique, incorporating a 3% (wt.) Er2O3 additive, results in the most advantageous results with respect to the characteristics of gamma ray absorption. The S3 sample demonstrated the greatest degree of neutron absorption, as demonstrated by a recorded value of 0.857 μSv/h, where the S1 sample demonstrated the minimum level of absorption, as evidenced by a recorded value of 0.452 μSv/h. Based on the observed effects on neutron and gamma-ray attenuation behaviors in ODS-HEAs, it can be concluded that Er2O3 exhibits characteristics of a monotonic oxide. This feature is particularly advantageous for applications that necessitate a dual enhancement in these behaviors. It can also be concluded that the S1 sample may be deemed appropriate for situations where the utmost consistency of chain reactions in nuclear reactor fuel rods is desired, due to its possession of the lowest neutron absorption properties.
AtıfScopus22OpenAlex26İncele - MakaleAçık Erişim2022Characterization and dye adsorption effectiveness of activated carbon synthesized from olive pomace
Deniz, Fatma; Başgöz, Öyküm; Güler, Ömer; Mazmanci, Mehmet Ali
Studies, about products obtained from agricultural wastes, have increased within the scope of zero waste studies. The olive pomace is produced as a result of olive oil production. In the present study, activated carbon was synthesized using the olive pomace taken from the olive pomace processing plant operating with a three-phase process. The synthesized activated carbon characterization was performed using Scanning Electron Microscope (SEM), Fourier-Transform Infrared Spectroscopy (FT-IR), Brunauer – Emmett – Teller (BET), and X-Ray Crystallography (XRD) devices. Olive pomace activated carbon (OPAC) was used for the adsorption of dye from an aqueous solution. The adsorption efficiency of the OPAC was investigated. The initial pH value of dye solution (6–9), the amount of activated carbon (0.5 and 1.0 g/L), and initial dye concentration (600–1200 mg/L) were optimized. Also, adsorption kinetic and isotherm calculations were evaluated. The optimum parameters were found as the original pH value (pH=8) of dye solutions, OPAC amount of 1.0 g/L and the initial concentration of 1000 mg/L. The Langmuir isotherm model and the pseudo-second-order kinetic model were found as the most suitable models. It can be said that the synthesized material can be used at dye removing from wastewater.
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İncele - MakaleAçık Erişim2022Scopus SJRQ2Effect of Cu, Sn and Sb addition on the structural, thermal and magnetic properties of body-centered cubic structured CoNiMnGaSi high entropy alloy
Şimşek, Telem; Özkul, İskender; Canbay, Canan Aksu; Avar, Barış; Şimşek, Tuncay; Güler, Seval Hale; Özcan, Sadan; Güler, Ömer; Chattopadhyay, Arun K.
In this study structural, morphological, thermal and magnetic properties of equiatomic CoNiMnGaSi (base), CoNiMnGaSiCu, CoNiMnGaSiSn and CoNiMnGaSiSb alloys are discussed. The formation of solid-solution nanocrystalline bcc structure of the alloys was determined by XRD and DTA techniques. SEM–EDS analyses also revealed the homogeneous distribution of the elements. The room temperature magnetic hysteresis loops showed that as-casted alloys reached saturation easily with coercivity less than or equal to 35 Oe. As the Cu and Sn were added to the alloy, the saturation magnetization was decreased from 112 emu/g to 50 emu/g, which was mainly due to the substitution of non-magnetic atoms to the magnetic Co in the base CoNiMnGaSi alloy, whereas the addition of Sb to the base alloy did not have a significant effect on the Ms. The CoNiMnGaSiSb was found to have the highest Curie Temperature of 670 K, which makes the alloy a promising candidate for power industry-related applications.
AtıfScopus3OpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ2Synergistic effect of boron nitride and graphene nanosheets on behavioural attitudes of polyester matrix: Synthesis, experimental and Monte Carlo simulation studies
Başgöz, Öyküm; Güler, Seval Hale; Güler, Ömer; Canbay, Canan A.; Zakaly, Hesham M.H.; Issa, Shams A.M.; ALMisned, Ghada; Tekin, H.O.
We report the synergistic effects of boron nitride and graphene nanosheets on physical, structural, and nuclear radiation attenuation properties of polyester matrix-incorporated nanocomposites. Some critical material properties are thoroughly evaluated for several types of synthesized samples. Polyester is employed to strengthen graphene and boron nitride nanolayers, and their characteristics are investigated in detail. Additionally, we report the gamma-ray and fast neutron attenuation characteristics of synthesized nanocomposites to get a better understanding of the reinforcing effect as a function of material type and weight percentage. Thermal analysis findings indicate that adding graphene lowers the decomposition temperature but co-adding graphene and BNNS enhances thermal decomposition in comparison to graphene itself. Tensile tests showed that the inclusion of both GRP and GRP/BNNS strengthens the material. Among the polyester composite samples analyzed, the G3 sample with the most GNP reinforcement had the lowest HVL values throughout the broadest range of energy levels investigated. The recent findings may be beneficial to the scientific community in terms of incorporating these reinforcing types and ratios into polyester materials for a variety of applications, including industrial and research purposes.
AtıfScopus22OpenAlex19İncele - MakaleYalnız künye2022Scopus SJRQ2Production and properties of epoxy matrix composite reinforced with hollow silica nanospheres (HSN): mechanical, thermal insulation, and sound insulation properties
Demir, Eda; Güler, Ömer
Hollow silica nanospheres (HSNs) have superior properties such as low density, low dielectric constant, low thermal conductivity, good sound absorption, dispersibility, fluidity, and stability. They have the potential to be utilised as a reinforcing material in the development of next generation composites due to their properties. Epoxy is one of the commonly utilised polymers in today’s technology. Production of epoxy matrix composite materials reinforced with particles having superior properties will open up new application areas for epoxy. In this study, mesoporous HSNs were produced. The mechanical, thermal and sound insulation properties of the composite were examined by reinforcing these mesoporous HSNs to the epoxy matrix. The epoxy matrix was reinforced with HSNs at 1 wt.%, 5 wt.%, and 10 wt.%. When the concentration of HSNs in the epoxy matrix was increased, its strength increased and its ductility decreased. While the non-reinforced epoxy had a tensile strength of 36.45 MPa, but the tensile strength of epoxy at the end of 10% HSN reinforcement reached 89.06 MPa. The strain % reduced in half. The sound insulation properties of epoxy improved as the concentration of HSNs increased. Thermal conductivity coefficient dropped up to a 5% reinforcement ratio, and then increased slightly at a 10% reinforcement ratio. The microstructure analyses indicated that when the reinforcement ratio increased, difficulties in the distribution of reinforcements to the matrix appeared. Furthermore, it was observed that when the matrix/reinforcement interface was improved, the properties of the composite improved.
AtıfScopus14WoS13OpenAlex12İncele - MakaleAçık Erişim2020Scopus SJRQ2The effect of graphene nanoplatelets on technical properties of micro- and nano-sized TiO2 matrix: a comparative research study on electrical and optical characteristics
Güler, Ömer; Ayhan, Hakan; Başgöz, Öyküm; Yavuz, Çağdaş; Albayrak, M. Gökhan; Evin, Ertan; Safa, Hasan; Yahia, Ibrahim S.
In this study, titanium dioxide (TiO2)-based graphene nanoplatelets (GNPs)-reinforced composite materials were produced and the electrical and optical properties of the composite materials were investigated. Graphene, which was used as a reinforcing material, was produced by using liquid-phase exfoliation method. While the TiO2 used as matrix material was commercially available for the first group of samples, it was produced by using the sol–gel method for the second group of the samples. Different rates of graphene were added to the TiO2 powders which were commercially available and produced by using sol–gel method. GNPs used as a reinforcing material were subjected to TEM analysis. The resulting composite materials were structurally examined in SEM and XRD. Then, the changes in electrical conductivity of these composites under the impact of temperature were measured. UV–Vis spectrometers of the samples were taken and their optical properties were determined. When temperature-based electrical examination of the produced composite materials was performed, an increase was observed on the electrical conductivity values in both groups of samples as a result of addition of the reinforcing element. In addition, TiO2-containing composites produced by using sol–gel method had lower electrical conductivity comparing with commercially purchased TiO2-containing composites especially at high temperatures. In the optical measurements, it was observed that there was an increase in the optical bandgap energy range values with GNPs reinforcement but a decrease in the reflectance values.
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