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Item A modelling study for the health risk posed by nuclear power plant in Bulgaria at different parts of Turkey(Parlar Research and Technology, 2004) Ünver, Özge; Tuncel, Gürdal; Kozloduy; TAEK-NGDIn this study, following a severe accident in Kozloduy nuclear power plant in Bulgaria, how Turkey will be affected has been investigated. The atmospheric dispersion model used is Hybrid Single Particle Lagrangian Integrated Transport (HySPLIT) model.For the simplicity, the release of only I-131 and Cs-137 for the worst-case accident scenario was modeled by HySPLIT for each day of the arbitrarily selected year 2000 to find the worst day of deposition, which was seen to result from the release beginning on April 7th 2000 and accumulated at the end of the 15-day simulation. Afterthat release of all fission products was modeled for the worst deposited day. Radiation dose at different receptors, which are 12 grids throughout Turkey, was calculated via inhalation, ingestion and external radiation pathways. Delayed health risk, fatal cancer, non-fatal cancer and hereditary risks, were investigated for the receptor points. The mostly affected part of Turkey fatal cancer is 0.121%. The same approach was applied to investigate the health risk of the proposed nuclear power plant at Akkuyu, Turkey. In this case, it was seen that the worst deposited day was resulted from the release beginning on 21st of February 2000 and accumulated at the end of the 15-day simulation. The worst affected part was found as the area between Kayseri, Niğde and Nevşehir with the total effective dose commitment of 0.108 Sievert and the individual risk of suffering from fatal cancer 0.54%. KEY WORDS: Kozloduy, Turkey, accident, HySPLIT,dose,risk.Item Beneficiation of Eskişehir Beylikova Bastnasite Ore and Rare Earth Elements Recovery(Scopus, 2023-11-14) Türker, Gülşah; Koç Delice, Tülay; Temizkalb, Arda; Özgür, Özgün Cem; Soydaş Sözer, BelmaUnique magnetic, optical and electrical properties of rare earth elements (REEs) have be come essential in modern high technology. Considering this necessity of technology, efficient man agement and utilization of rare earth resources is of great importance. Even though there are more than 250 rare earth minerals in around the world, the number of minerals that can be economically processed, not exceeding three. Among these minerals, bastnaesite, has a significant impact on sci entific advancement and social progress. This project aims to contribute to the establishment of a sustainable supply chain for REE in Turkey and Europe by conducting research and development activities to leverage the utilization of REEs found in our country. The primary objective of this project is to extract rare earth oxides from complex ore in the Eskişehir Beylikova region, which holds the largest reserve potential discovered in our country, and to refine these metal oxides to produce metals that can be used in magnet manufacturing. The project encom passes five main work packages during three years: Project management, ore enrichment, solvent extraction based purification, utilization of REOs and metals in additive material and magnet pro duction.Item Boron Salicylate Ester Compounds as Boron Therapeutics. Their Synthesis, Structural Characterizations and Anticancer Effects Against MDA-MB-231(SPRINGER NATURE, 2024-10-03) Bolat, Melda; Köse, Dursun Ali; Akbaba, SemaThe element boron forms a wide range of borate minerals with different properties. Borate minerals make it possible to design boron-containing molecules with new biological properties in terms of their chemical structure and properties. It is known that boron compounds have antioxidant, anti-inflammatory, anti-tumor and anti-cancer properties. This makes boron compounds important for the future development of boron chemotherapeutics, boron supplements and new drugs. Reliable scientific studies on boron compounds will facilitate the clear presentation of their functions in its biological applications and metabolism. In this study, boron monoester and boron diester structures were synthesized with salicylic acid ligand. To stabilize boron ester structures, Na+, K+, Mg2+, Ca2+ cations were used as counter-ions. Structural properties of the synthesized substances, molecules obtained by crystallization/precipitation from aqueous solutions in solid state, elemental analysis, melting point determination, infrared spectroscopy analysis (FT-IR), thermal analysis (TGA/DTA), mass analysis (GC-MS) and single crystal analysis. Structural properties were tried to be explained by structure analysis (SC-XRD) methods. Additionally, the anticancer potential of boron salicylate esters against the MDA-MB-231 human breast adenocarcinoma cell line was examined. The K-B salicylate diester molecule was found to have the most potential potency with the lowest IC50 value against the MDA-MB-231 cell line. The anticancer potential of boron salicylate esters can be further investigated with other cancer models with the combination of anticancer drugs. It is also thought that the mechanism of action of these molecules may help reveal their further applications.Item Descriptive Process Mineralogy to Evaluate Physical Enrich-ment Potential of Malatya/Kuluncak Rare Earth Ore through MLA(MDPI, 2023-09-12) Ersoy, Burakhan; Beşirli, Mehmet Umut; Topal, Selim; Soydaş Sözer, Belma; Burat, FıratRare Earth Elements (REE) are indispensable parts of magnetic, phosphor, metal alloys, catalysts, ceramics, glass, pol-ishing, and defense systems industries due to their unique physical and chemical properties. Currently, China is the largest sup-plier in the world with a production of more than 95% of the world’s Rare Earth Oxides (REO). To reduce the influence of China on the REE market, the countries have started to develop their national strategies for the production and use of REE-bearing resources. Within the scope of this study, particle size, chemical, MLA, XRD, and SEM-EDS analysis were performed for material characterization, and shaking table, centrifugal, and magnetic separations were carried out for the beneficiation of Mala-tya/Kuluncak rare earth ore. The XRD analysis indicated that the representative sample consists of major minerals such as albite, calcite, montmorillonite, muscovite, titanite, kaolinite, clinochlore, and aegirine. Parisite, bastnaesite, Zr-REE-Silicate, Fe-REE-Oxide, and Ca-Ti-Nb-REE-Oxide were detected as REE-bearing minerals by MLA. The chemical analysis resulted in a ∑REO grade of 3,628 g/t and the ore consists of mostly light REE. According to the result of the gravity separation for the coars-est fraction, about 11.3% by weight of the total feed was concentrated as a heavy product assaying 6,437 g/t ∑REO. As a result of magnetic separation, magnetic products with 5,561 g/t and 6,013 g/t ∑REO were obtained at coarse and fine fractions, respective-ly. Finally, the characterization studies and enrichment results were correlated, and very important and meaningful indications about the behavior of REE-bearing minerals were obtained.Item Development of CuO nanoparticles modified electrochemical sensor for detection of salbutamol(Iop Publishing, 2024-04-29) Koc Delice, Tulay; Ak Azem,Funda; Ozdemir, Kazim; Alpat, SenolMetal oxide structures are being utilized in an increasing variety of applications. This study used cyclic and differential pulse voltammetry techniques to investigate the possible utilization of copper oxide (CuO) nanoparticles modified carbon paste electrode (CPE)for the redox reactions of salbutamol (SAL). The electrochemical performance of the SAL analyte in a complex matrix environment in Ventolin was evaluated in order to assess the appropriateness of the proposed sensor in a real sample environment. CuO nanoparticles were produced via a straightforward, cost-effective and efficient sol– gel method, and characterization studies of synthesized CuO nanoparticles were performed by scanning electron microscopy, x-ray Diffraction (XRD), and x-ray photoelectron spectroscopy. The synthesized CuO nanoparticles had a spherical shape and particle size was found to be 74 nm. The crystal size of the CuO particles was calculated to be 21.79 nm using the Debye–Scherrer equation. Under optimal conditions, differential pulse voltammetry demonstrated a linear response in the 50 nM to 100 μM range, with a salbutamol detection limit of 50 nM (S/N = 3). The SAL concentration (R2= 0.9971)was found to have a good correlation coefficient. The reproducibility of the biosensor was investigated and evaluated with a relative standard deviation of 3% (n = 8). The storage stability of CuO modified CPE for two weeks was evaluated based on the response of DP current measured at intervals every two days. According to the measurement results, the modified electrode exhibited good stability and reproducibility while maintaining 80% of its stability. It is also a rapid and dependable sensor candidate with a measurement time of approximately 20 s. The developed electrode has been utilized successfully to determine doping material with improved performance.Item Exploring the Photoluminescence Origins of Natural Boron Mineral (Tincal) and Its Waste Byproducts(SSRN 4891422, 2024-07-10) Karacaoglu, Erkul; Yungevis, Hasan; Acikgoz, Sabriye; Gul, Mert; Ates, Esen Gul; Yildirim, CennetMany natural minerals can exhibit luminescence due to impurities and their crystal structures. Evaluating the waste generated from processing these materials presents significant research opportunities. This study explores tincal, a natural boron source, and its waste, discussing their structural and luminescence properties. Both the mineral and its waste show similar phases like dolomite and calcite. In terms of luminescence, both exhibit PL emission in the 500-650 nm range. Emphasis is placed on evaluating the waste, with heat treatment revealing notable changes. At temperatures exceeding 500°C, the waste transforms from dolomite to monticellite, causing a red-shift in PL emission to the 600-850 nm range. XPS analysis of untreated and heat-treated waste confirms elemental compositions, highlighting the influence of boron on structural changes during heat treatment, despite trace elements like Mn and Fe being undetected.Item FAST AND THERMAL NEUTRON REMOVAL CROSS-SECTION FOR CERAMIC GLASS ALUMINUM OXYNITRIDE(Dergipark, 2024-09-08) Yıldırım, AydınThis study investigates the effectiveness of transparent aluminum oxynitride (AlON) in neutron shielding, focusing on both fast and thermal neutrons. Using conventional radiation attenuation parameters, the macroscopic neutron removal cross-sections of AlON were calculated for varying neutron energies and material thicknesses. The Geant4 simulation toolkit was employed to model and analyze the neutron interactions with AlON. The results indicate that AlON exhibits a high neutron shielding capacity for fast neutrons (2 MeV), with transmission factor values ranging from 0.783 to 0.260 for material thicknesses between 1 and 10 cm. These values are nearly identical to those for water, which range from 0.782 to 0.257, highlighting AlON's comparable performance. However, for thermal neutrons, AlON's performance was less effective, only surpassing lead but not concrete or water. The findings suggest that while AlON is highly effective for fast neutron shielding, it may require complementary materials to adequately shield thermal neutrons. This could involve using AlON in combination with other materials to create a more comprehensive neutron shielding solution. AlON shows significant potential as a neutron shielding material, particularly for fast neutrons. Its integration with additional shielding materials could enhance its overall effectiveness, making it suitable for various nuclear and radiation protection applications.Item First constraints on Non-minimally coupled Natural and Coleman-Weinberg inflation in the light of massive neutrino self-interactions and Planck+BICEP/Keck(SISSA, 2024-07-22) Bostan, Nilay; Roy Choudhuryb, ShouvikIn this work, for the first time in literature, we compare the predictions of nonminimally coupled Natural and Coleman-Weinberg potentials in the ns − r plane against the constraints from the latest cosmological data in an extended ΛCDM model where we include non-standard self-interactions among massive neutrinos, mediated by a heavy scalar or vector boson. For the inflationary potentials, we consider two different formulations in gravity that are non-minimally coupled to the scalar field of the inflaton: Metric and Palatini. We only consider the self-interaction to be present among τ-neutrinos and only at moderate strengths. This is because strong interactions among τ-neutrinos, or any strength self-interaction among electron- and muon-neutrinos, as well as any strength flavor-universal interactions, are strongly disfavoured from particle physics experiments. In terms of cosmological data, we use the latest public CMB datasets from Planck and BICEP/Keck collaborations, along with other data from CMB lensing, BAO, RSD, and SNe Ia luminosity distance measurements. We find that there are some situations where predictions from the inflationary models are ruled out at more than 2σ by the minimal ΛCDM+r model, but they are allowed in the self-interacting neutrino scenario.Item Gamma rays induced enhancement in the phytonutrient capacities of tomato (Solanum Lycopersicum L.)(Frontiers, 2023-08-03) Kantoğlu Kadriye Yaprak; İç Erhan; Özmen Dilan; Bulut F. Şebnem; Ergun Ece; Kantoğlu Ömer; Özçoban MustafaOne of the most important problems for the field-grown Ayaş tomato (Solanum lycopersicum Ayas population), which is preferred for consumption in Central Anatolia because of its aromatic taste, is that the shelf life is short because of insufficient fruit firmness. Therefore, a study was initiated to develop high-quality lines and variety candidates through mutation breeding in the current Ayaş population. In this study, the effective mutation dose (EMD50) was found to be 150 Gy for seeds using a Cobalt-60 gamma ray source. The main mutant population was generated by applying EMD50. During the study, mutant lines selected by following the classicalmutation breeding stages were evaluated in terms of yield and quality traits (antioxidant content, total soluble solid amount, fruit firmness, Brix, etc.) starting from the M4 stage. One of our aims was to determine and improve the phytonutrient content of field-grown tomatoes. The fruits of selected lines at the M4 stage were extracted by liquid-liquid partition and accelerated solvent extraction techniques and analyzed by High Performance Liquid Chromatography (HPLC) in this study. Itwas found that 28 of the 29mutant lines were significantly different from the control and mutant lines. Mutant lines 9-22, 8-90, 8-135, and 8-127 were determined to be the most promising for commercialization.Item GAMMA RAYS INDUCED ENHANCEMENT IN THE PHYTONUTRIENT CAPACITIES OF TOMATO (Solanum Lycopersicum L.)(Frontiers, 2023-08-03) Kantoğlu, K. Yaprak; İç, Erhan; Özmen, Dilan; Bulut, F. Şebnem; Ergun, Ece; Kantoğlu, Ömer; Özçoban, MustafaOne of the most important problems for the field-grown Ayaş tomato (Solanum lycopersicum Ayas population), which is preferred for consumption in Central Anatolia because of its aromatic taste, is that the shelf life is short because of insufficient fruit firmness. Therefore, a study was initiated to develop high-quality lines and variety candidates through mutation breeding in the current Ayaş population. In this study, the effective mutation dose (EMD50) was found to be 150 Gy for seeds using a Cobalt-60 gamma ray source. The main mutant population was generated by applying EMD50. During the study, mutant lines selected by following the classical mutation breeding stages were evaluated in terms of yield and quality traits (antioxidant content, total soluble solid amount, fruit firmness, Brix, etc.) starting from the M4 stage. One of our aims was to determine and improve the phytonutrient content of field-grown tomatoes. The fruits of selected lines at the M4 stage were extracted by liquidliquid partition and accelerated solvent extraction techniques and analyzed by High Performance Liquid Chromatography (HPLC) in this study. It was found that 28 of the 29 mutant lines were significantly different from the control and mutant lines. Mutant lines 9-22, 8-90, 8-135, and 8-127 were determined to be the most promising for commercialization.Item Inflation and reheating predictions of minimally coupled β-exponential potential with an R2 term in the Palatini formulation(T.C. Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu, 2024-08-29) Bostan, Nilay; Dejrah, Rafid H.In this work, we focus on the inflationary predictions of β-exponential potential models, where the field delineating the size of extra-dimension is represented as the inflaton. We include an R2 term in the Palatini gravity since it provides a well-motivated starting point for the analysis of physics at very high energies. Furthermore, the inflaton oscillates around the minimum of the inflation potential until the universe is reheated at the end of the inflationary epoch. This occurs during the reheating phase, at which inflaton decays into the Standard Model particles, which filled the universe. Regardingly, we extend our examination by taking into consideration the reheating effects on inflationary observables. Assuming the standard thermal history after inflation, we present the inflationary predictions, ns,r, dns/d ln k of β-exponential potential with minimal coupling in Palatini R2 gravity by considering the reheating cases. We show that this specific kind of model allows one to study a wide range of predictions to have a better analysis for the inflationary era by adjusting the model parameters, α, β, λ. In addition, different kinds of constraints from a variety of observations, such as BICEP/Keck, Planck 2018, the Baryon Acoustic Oscillations (BAO), as well as future possible detectable constraints by CMB-S4 are taken into consideration in this study. We find that our results are in good agreement with the recent data and sensitivity forecast for the future CMB-S4.Item Inflation in symmergent metric-Palatini gravity(Sissa, 2024-02-21) Bostan, Nilay; Karahan, Canan; Sargın, OzanIn this paper, we study the cosmological inflation phenomenon in symmergent gravity theory. Symmergent gravity is a novel framework which merges gravity and the standard model (SM) so that the gravity emerges from the matter loops and restores the broken gauge symmetries along the way. Symmergent gravity is capable of inducing the gravitational constant G and the quadratic curvature coefficient cO from the loop corrections of the matter sector in a flat space-time. In the event that all the matter fields, including the beyond the standard model (BSM) sector, are mass degenerate, the vacuum energy can be expressed in terms of G and cO. The parameter which measures the deviation from the mass degeneracy is dubbed ˆ α. The parameters, cO and ˆ α, of symmergent gravity convey the information about the fermion and boson balance in the matter (SM+BSM) sector in number and in mass, respectively. In our analysis, we have investigated the space of the symmergent parameters cO and ˆ α wherein they produce results that comply with the inflationary observables ns, r, and dns/dlnk. Wehaveshownthatthevacuumenergytogetherwiththequadraticcurvaturetermarising in the symmergent gravity prescription are capable of inflating the universe provided that the quadratic curvature coefficient cO is negative (which corresponds to fermion dominance in number in the matter sector) and the deviation from the mass degeneracy in the matter sector is minute for both boson mass dominance and fermion mass dominance cases.Item Influence of Gamma Irradiation on Pollen Viability, Pollen Tube Growth, and Fruit Development in Tomato (Solanum lycopersicum L.)(The Horticulture Journal / The Japanese Society of Horticulture, 2024-03-16) Kantoğlu Kadriye Yaprak; 372103The goal of this study was to assess whether irradiated pollen technology could be used in tomato breeding research. The effects of irradiation on pollen viability, fruit set rate, and embryo formation were investigated. For this purpose, pollens were exposed to gamma rays of 0, 50, 100, 200, 300, and 400 Grays (Gy). The effect of irradiation on pollen viability and tube growth was found to be significant based on counting and measurements performed under in vitro conditions at 24, 48, 72, and 144 h after irradiation. Fruit set and embryo formation in seeds were evaluated 30 days after pollination with pollen irradiated at different doses. It was determined that increasing the irradiation dose resulted in reduced pollen viability and tube length. Endosperm formation was detected in all seeds after 50 Gy of irradiation. However, 50 Gy had no effect on gynogenesis stimulation. Therefore, 100, 200, and 300 Gy doses stimulated embryo formation without endosperm, while 400 Gy of irradiated pollen did not support fruit to set. These results indicate the importance of harvesting time to obtain viable embryos. It should be retracted to an earlier time since late harvest resulted in necrosis of globular embryos on the 30th day after irradiation. Pollination with one-day-old irradiated pollen was more suitable for gynogenesis induction. The results showed that the irradiated pollen technique can be applied in tomato breeding studies, especially in terms of purifying the obtained breeding lines in a shorter time. In particular, determining the appropriate induction dose for gynogenesis depending on the genotype is important for stimulation efficiency.Item Investigation of the Effects of Ion Sources and RF Power on the Neutron Production Rate at SNRTC-IEC Fusion Device(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-08-19) Bölükdemir, Arife Seda; Olgaç, Yeşim; Alaçakır, AliThe studies on inertial electrostatic confinement device are generally focused to increase the particle production. One way to achieve this is to increase the number of the ion source. In this study, D-D fusion reaction was carried out in the SNRTC-IEC fusion device (previously at TAEK, now re-established as TENMAK) at 85 kV cathode voltage and 5×10-4 mbar pressure, and the effect of ion sources and RF power on the neutron production rate was investigated. To ensure a high concentration of ions in the center of the cathode, three Inductively Coupled Plasma (ICP) deuterium ion sources were added to this device. As the number of ion sources increased from 1 to 3, the neutron production rate increased from 2.3 104 n/s to 3.6 105 n/s. Two ion source configurations were used to examine the effect of RF power. It was observed that when the RF power was increased from 40 W to 200 W the neutron production rate increased linearly from 4.6 104 n/s to 1.7 105 n/s.Item Large Field Polynomial Inflation in R2 Gravity with non-minimal coupling: Palatini formalism(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-10-11) Bostan,Nilay; Karahan, Canan; Sargın, OzanIn this paper, we employ the Palatini formalism to investigate the dynamics of large field inflation using a renormalizable polynomial inflaton potential in the context of quadratic gravity. Assuming instant reheating, we make a comparative analysis of Large Field Polynomial Inflation (LFPI). We first consider inflaton (i) minimally and (ii) nonminimally coupled to R gravity, and then we continue with inflaton (iii) minimally and (iv) non-minimally coupled to R + R2 gravity. We scan the parameter space for the inflationary predictions (ns and r) consistent with the Planck and BICEP/Keck 2018 results as well as the sensitivity forecast of the future CMB-S4 and depict the compliant regions in the ϕ0 −β plane where ϕ0 and β are two parameters of polynomial inflation model which control the saddle point of the potential and the flatness in that region respectively. Furthermore, for the polynomial potential, we display the behavior of the running of the spectral index αs ≡ dns/d ln k with respect to the spectral index ns itself for all the cases.Item Measurement of Radon Concentration in Metro Stations of Istanbul, Türkiye(SSRN, 2024-10-24) Akkaş, Ayhan; Baş Mor, Hatice; Ataksor, Berna; Bingöldağ, Nesli; Duhan, Fatma; Köseoğlu, Şule; Altunbayrak, A.SibelThe main objective of this study was to determine the levels of radon concentrations in different metro lines in Istanbul. Measurements were conducted in underground stations of five distinct metro lines: M1A, M1B, M3, M4 and M6. Radon activity concentration (RAC) values were determined by means of measurements. The annual effective dose values were calculated for employees on the metro line and for passengers using these lines. The lowest radon concentration was found to be 15 Bq/m3, while the highest was 80 Bq/m3. It has been shown that the effective dose received by individuals from radon irradiation in underground stations does not appear to contribute significantly to the annual average effective dose. The city of Istanbul is characterised by a rugged topography, with some metro stations reaching depths of up to 40 metres below ground level. Despite this, the increasing depth of the metro stations did not result in a significant increase in radon concentration, due to the effectiveness of the ventilation systems.Item Metabolite profiling of four Tunisian Eucalyptus essential oils and assessment of their insecticidal and antifungal activities(Elsevier, 2023-11-16) Khedri, Sana; Khammassi, Marwa; Bouhachem, Sonia Boukhris; Pieracci, Ylenia; Mabrouk, Yassine; Seçer, Emine; Amri, Ismail; Flamini, Guido; Hamrouni, LamiaAphids (Aphidoidea) and Fusarium spp. are widely recognized as destructive pests that cause significant damage to crops on a global scale. This study aimed to ascertain the chemical composition of essential oils (EOs) of four Tunisian Eucalyptus species and evaluate their toxicity against common aphids and phytopathogenic fungi. The EOs were obtained via hydrodistillation and subsequently analyzed using GC-MS. The chemical composition analysis revealed the presence of five distinct chemical classes in the EOs: monoterpene hydrocarbons (3.8–16.7 %), oxygenated monoterpenes (5.5–86.0 %), sesquiterpene hydrocarbons (0.2–2.2 %), oxygenated sesquiterpenes (4.2–86.7 %), and non-terpene derivatives (0.1–14.1 %).Hierarchical clustering analysis (HCA) and principal component analysis (PCA) of the Eucalyptus leaf EOs highlighted significant differences among them, leading to the generation of distinct HCA clades representing at least twelve major components. The statistical analysis clearly demonstrated a dose-response relationship, indicating the impact of the tested EOs on the growth of insects and fungal mycelium. The observed effects varied due to the variability in the chemical compositions of the EOs. Notably, among the EOs tested, Eucalyptus lesoufii Maiden exhibited particularly potent effects against the targeted insect and fungal species. This research contributes to the ongoing explo- ration of natural alternatives to chemical pesticides, providing further insights for potential in- dustrial applications. It underscores the versatility of these EOs and their potential as valuable candidates in strategies for pest and disease management.Item Microstructural Investigation of Discarded NdFeB Magnets After Low‑Temperature Hydrogenation(Springer, 2024-06-16) Habibzadeh, Alireza; Kucuker, Mehmet Ali; Çakır, Öznur; Gökelma, MertolWith the imposition of some restrictions or the export of rare earth elements (REEs) by China, a dominant producer of these elements, the supply of REEs will soon be a challenge. To mitigate the supplv risk of REEs, a lot of attention has been paid to recycling recently. Despite the more commun recycling methods, including hydrometallurgical and pyrometalluraıcal processes, the hydrogen processing of magnetic serap (HPMS) is stili in the development stage. Magnet-to-magnet recycling via hydrogenation of end-of-life (EoL)NdFcB magnets provides a fine powder suitable for the produetion of new magnets from secondary sources, One of the crucial aspects of HPMS is the degree of recovery of the magnetic properties, as the yield effıciency can easily reach över 96%, The amount. morphology. and distribution of the Nd-rich phase are the key parameters to achieve the highest ma\imum energv produet (BH)max by isolatıng the matrix grain. Therefore, a better insight into the microstructure of the matrix grains and the Nd-rich phase before and alî er hydrogenation is an important aspect in terms of restoring the final magnetic properties. In this study, a low-temperature hydrogenation process in the range of roon. temperature to 400 °C was conducted to recycle NdFeB magnets fforn ııscarded hard disk drives (HDDs), and the hydroaenated powder was chaıacterized by eleetron microscopy and X-ray diffraction. fhe results show that there are three different morphologies of the Nd-rich phase, which undergo two different transformations through oxidation and hydride fbrmation. While at lower temperatures (below 250 °C) the degree of pulverization is higher and the experimental evidence of hydride formation is less clear, the opposite is true at higher temperatures. The formation of neodymium hydride at higher temperatures prevents fiırther oxidation of the Nd-rich phase due to its higb stability.Item Preparation and characterization of various column-filling materials in order to optimize 68Ge-68Ga generator column(T.C. Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu, 2024-06-15) Ekebaş Çavdar, Elif; Oktar, Okan; Çantay, Eren; Ergun, Ece; Ertaş, Nur Banu; Aydın, Büşra; Abay, ÖzlemIn order to obtain ready-to-use 68Ga in Positron Emission Tomography (PET) applications, the 68Ge/68Ga generator system is an ideal source and allows PET imaging in centers without cyclotrons. Radiochemical separation of Ge (mother) and Ga (daughter) radionuclide though commercial generators is carried out with columns consisted of inorganic metal oxides. In this study, commercially available tin dioxide (SnO2), laboratory-synthesized SnO2, titanium dioxide (TiO2) and zeolite as a column filling material in 68Ge/68Ga generators were used. The sorption behavior of column-filling materials as adsorbent was investigated without the use of radioactive materials. All elements, especially Ge and Ga for representing 68Ge/68Ga generator system, were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In addition, since these column-filling materials used in the thesis will be exposed to radiation during the shelf life of the 68Ge/68Ga generator, their radiation stability were investigated. Structural characterization studies were performed with, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). In order to calculate surface area and pore sizes, Brunauer-Emmett-Teller (BET) method were used. The promising results obtained in this study, calcined at 900 °C Kw_SnO2 would be prepared and evaluated of pilot 68Ge/68Ga generators.Item Radiation Attenuation Properties of Transparent Aluminum Oxynitride: A Comprehensive Study(Sprınger, 2024-04-09) Yıldırım, AydınThe investigation of radiation-durable materials with outstanding gamma shielding capabilities and lead-free alternatives remains a compelling area of research. This study fills a critical gap by exploring, for the first time, the radiation attenuation properties of the novel material aluminum oxynitride (AlON) and its shielding mechanism. Utilizing the XCOM database and Geant4 Monte Carlo simulation toolkit, we systematically examined AlON’s linear attenuation coefficient, mass attenuation coefficient, half-value layer, tenth-value layer, mean-free path, effective atomic number, and effective electron density. Comparing AlON to traditional shielding materials and glasses, including both lead-containing and lead-free compositions, our study suggests its superiority over concrete and lead-free glasses. At higher energies, AlON demonstrates comparability with lead-doped materials. These findings contribute valuable insights into the potential applications of AlON across diverse radiation shielding contexts. This research provides a foundational understanding of AlON’s radiation attenuation capabilities, paving the way for future exploration and practical applications in the field of gamma shielding.