Makale

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A computer program to help for resolution of complex and poorly resolved Cu2+ and VO2+ ions doped single EPR spectra
(Taylor & Francis, 2009-11-01) Bıyık, Recep; Çemberci, Mustafa; Tapramaz, Recep; 0000-0001-7929-4395; TAEK-ÇNAEM
Complex and poorly resolved Cu2+ and VO2+ doped single-crystal electron paramagnetic resonance (EPR) spectra are some of the serious problems that exist in this area. In order to help the resolution of this sort of spectra, and for easily resolvable spectra as well, a versatile computer program known as EPR RESolution, or EPRES, is presented. All detectable line positions in the single-crystal spectra taken in three mutually perpendicular planes are given as input. The program plots these line positions. The user then manually determines the lines by selecting the true data points on the plot and fitting them to a well-known variation function. If selection is not suitable, the process is canceled and renewed. By this process, as many resolvable lines as in the spectra can be resolved and determined. The user then groups the resolved lines according to the paramagnetic center to which they belong. This includes the attribution of correct nuclear spin I and MI to correct lines. After this step, hyperfine and g tensor elements can be found, constructed, and diagonalized. [Supplemental materials are available for this article. Go to the publisher’s online edition of Spectroscopy Letters for the following free supplemental resource: a copy of the EPRES computer program.]
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-NGD
In 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.
A portable fast neutron radiography system for nondestructive analysis
(SCİENDO, 2019) Kam, Erol; Reyhancan, İskender Atilla; Bıyık, Recep; 0000-0001-7929-4395; TAEK-ÇNAEM
Depending on the neutron energy used, neutron radiography can be generally categorized as fast and thermal neutron radiography. Fast Neutron Radiography (FNR) with neutron energy more than 1 MeV opens up a new range of possibilities for a nondestructive inspection when the inspected object is thick or dense. Other traditional techniques, such as X-ray, gamma ray and thermal neutron radiography do not meet FNRs penetration capabilities in this area. Because of these distinctive features, this technique used in different industrial applications such as security (cargo investigation for contraband such as narcotics, explosives and illicit drugs ), gas/liquid flow and mixing, radiography and tomography of encapsulated heavy shielded low Z compound materials. The FNR images are produced directly during exposure; the neutrons create recoil protons, the protons activate a scintillator screen, the images can be collected with a computer controlled charge –coupled device (CCD) camera and finally the picture can be saved on a computer for the image processing. The aim of this research is to set up a portable fast neutron radiography (FNR) system and to test it for use in nondestructive testing of different composite materials. Experiments were carried out by using fast portative neutron generator Thermo Fischer MP320.
A review of the TAEA proficiency test on natural and anthropogenic radionuclides activities in black tea
(Elsevier B.V., 2018-04) Yeltepe, Emin; Şahin, Namık Kemal; Aslan, Nazife; Hult, Mikael; Özçayan, Gülten; Wershofen, Herbert; Yücel, Ülkü; TAEK-SANAEM
A proficiency test amongst 15 Turkish laboratories with participation of 5 non-Turkish laboratories was organized to determine the 137Cs, 40K and 90Sr massic activities in black tea powder samples. The bulk material, consisting of tea produced in 2014, was mixed with contaminated tea that was withdrawn from the market after the Chernobyl accident. Nineteen laboratories reported 41 results. The evaluation of the results was based on the accuracy and precision criteria adopted by the IAEA Proficiency Testing Group and resulted in 49% acceptable results, 19% acceptable with warning and 32% were found to be not acceptable.
A Simple Synthesis of 2,2'-Azobis[(15-crown-5)- eno[g]quinoxaline]
(Chemische Berichte, 1986) Gül, Ahmet; Okur, Ali İhsan; Can, Şevket; Bekaroğlu, Özer; TAEK-ÇNAEM
A theoretical analysis of the explanation of the significant differences in antiferromagnetic interactions between homologous μ-alkoxo and acetate bridged dicopper(II) complexes: ab initio and semi-empirical calculations
(Elsevier, 2004-07) Zeyrek, C. Tuğrul; Elmalı, Ayhan; Elerman, Y.; 0000-0001-6744-7841; TAEK-ANAEM
A magnetostructural classification of dimmers, containing the Cu (μ-alkoxo) Cu core, based on data obtained from X-ray diffraction analysis reported in the literature has been performed. In these complexes, the local geometry around the copper ions is generally a square planar and each copper ion is surrounded by one N atom and three O atoms. The influence of the overlap interactions between the bridging ligands and the metal (Cu) d orbitals on the super-exchange coupling constant has been studied by means of ab initio Restricted Hatree–Fock molecular orbital calculations. The interaction between the magnetic d orbitals and highest occupied molecular orbitals of the acetate oxygens has been investigated in homologous μ-acetato-bridged dicopper(II) complexes which have significantly different −2J values (the energy separation between the spin-triplet and spin-singlet states). In order to determine the nature of the fronter orbitals, Extended Hückel molecular Orbital calculations are also reported. Ab initio restricted Hartree–Fock calculations have shown that the acetato bridge and the alkoxide bridge contribute to the magnetic interaction countercomplementarily to reduce antiferromagnetic interaction.
Achieving superior strength and ductility in oxide dispersion strengthened IN625 alloy produced by laser powder bed fusion
(ELSEVIER, 2024-12-19) Demirci, Kadir Tuğrul; Özalp, Ali; Güner Gürbüz, Selen Nimet; Bükülmez, İlhan; Aksu, Erhan; Aydoğan, Eda
In this study, a new grade of oxide dispersion strengthened (ODS) Inconel 625 (IN625) alloy having the composition of 0.3 wt% Y2O3 – 0.4 wt% Hf – IN625 has been developed and produced by laser powder bed fusion (L-PBF). Production parameters have been determined for standard and ODS IN625 alloys to yield >99.9% densification. Microstructural analyses reveal similar texture along <001> while a larger but homogenous strain distribution exist in ODS IN625. Nano-particles are determined to be mostly Y-Hf-O and Y2O3 with an average size of ~30 ± 18 nm and 2.2 ± 1.1x1013 m-2 areal fraction. Tensile tests at room temperature (RT) and 700 °C demonstrate superior mechanical properties of ODS-IN625, particularly at elevated temperatures. While the yield strengths of standard and ODS IN625 alloys are similar (~680 MPa), ductility of ODS IN625 is slightly larger at RT. However, the yield strength of ODS-IN625 increased by 7.4%, reaching ~580 MPa, compared to the standard IN625, which has a yield strength of ~540 MPa at 700 °C. More notably, the ductility of ODS IN625 shows a remarkable improvement, increasing from ~12% in the standard IN625 to ~22%, representing an increase of more than 80%. Detailed microstructural analyses on the fracture surfaces of the ODS IN625 alloys exhibit submicron dimples, as well as an extensive amount of dislocation loops, Lomer-Cortrel (L-C) locks, and stacking fault tetrahedra. Nano-oxides were determined to be responsible for the dislocation wall structure and dislocation distribution which in turn improves the mechanical properties. This study sheds light on tailoring the strength-ductility balance in IN625 alloys by introducing the nano-oxide particles and perceiving the mechanism of this improvement.
Activity concentrations of 224Ra, 226Ra, 228Ra and 40K radionuclides in refinery products and the additional radiation dose originated from oil residues in Turkey
(Oxford University Press, 2013-10) Parmaksız, Aydın; Ağuş, Yusuf; Bulgurlu, Figen; Bulur, Emine; Yıldız, Çiğdem; Öncü, Tolga; AAH-5187-2020; 0000-0003-4000-5175; TAEK-SANAEM
Total of 56 crude oil, refinery product, waste water, sludge and scale samples collected from three refineries were measured by gamma-ray spectrometry. Except for nine samples, all refinery products samples were found below the minimum detectable activity (MDA) values. 224Ra, 226Ra, 228Ra and 40K activity concentrations in crude oil and refinery product samples were measured from MDA values to 11.7±4.5, 14.9±3.5, 11.6±4.5, 248.5±18.5 Bqkg-1 respectively. 224Ra, 226Ra, 228Ra and 40K activity concentrations in scale, sludge and water samples were measured from MDA values to 343.7±11.8, 809.2±29.0, 302.5±21.6, 623.0±80.9 Bqkg-1 respectively. Radium equivalent activities of residue samples were calculated up to 1241.8±42.4 Bq/kg. Maximum activity concentration index and alpha index were found 4.2 and 4.0 respectively. The annual effective doses of four residue samples were calculated equal or above permitted dose rate for public, i.e. 1mSv/y.
Activity concentrations of 226Ra, 232Th, 40K and 137Cs radionuclides in Turkish medicinal herbs, their ingestion doses and cancer risks
(Taylor and Francis, 2014-11) Parmaksız, Aydın; Ağuş, Yusuf; AAH-5187-2020; 0000-0003-4000-5175; TAEK-SANAEM
Twenty-two medicinal herb samples, each representing a distinct species, were collected from Turkish markets and measured by the gamma spectrometric method. The activity concentration of 226Ra in medicinal herbs was found in the range of minimum detectable activity (MDA) and 15.1 ± 2.2 Bqkg−1. The activity concentration of 232Th ranged from MDA values to 3.5 ± 0.8 Bqkg−1. The activity concentration of 40K varied between 50.0 ± 16.8 and 1311.5 ± 57.3 Bqkg−1. All 137Cs activity concentrations of medicinal herbs were found to have lower than MDA values. The bone surface dose, lower large intestine and colon doses were found to be 182.9, 18.8 and 18.7 µSvy−1, respectively. The highest committed effective dose originated from the annual ingestion of 1 kg medicinal herb was calculated notably low as 9.0 µSv. The cancer risk of ingestion of medicinal herbs was found to be small enough to be neglected. The selected Turkish medicinal herbs are considered safe for human consumption.
An analysis and discussion on the concepts of state responsibility and state liability in the context of a nuclear accident or radiological emergency with transboundary effects
(Süleyman BOŞÇA, 2016-01) İnal, Arda; TAEK-NGD
As is known, nuclear related activities, by its very nature, pose special risks to individuals, property and the environment. But it is also well known that nuclear energy holds significant benefits in various fields including electricity production, medicine, agriculture etc. As a result of their both risks and benefits, nuclear related activities need to be kept under a legal regime of regulations covering a regulatory framework, authorisation, continuous control, inspection and imposing sanctions to protect health and safety of persons and the environment. Therefore, very important and various responsibilities are attributed to states via international organizations and legal instruments. For instance, in accordance with the Convention on Nuclear Safety ; “Each Contracting Party shall establish and maintain a legislative and regulatory framework to govern the safety of nuclear installations.” For another instance, states must establish or designate regulatory bodies which are financially independent, separated from the organizations for utilising or promoting nuclear energy, adequately authorised and competent to set standards and enforce them within the legal framework of the state. At the present time, there are plenty of international treaties and conventions and other instruments agreed or accepted by states and innumerable of national standards or regulations to ensure nuclear safety and security to protect individuals, property, environment and even next generations. Despite all these national and international instruments, Fukushima Daiichi nuclear accident occurred in Japan in 2011 and it has shown us that, nuclear accidents may occur in anytime, anywhere despite the existence of rules, standards, regulations, laws or treaties. At this very point, nuclear liability law and liability regimes come forward and concern with procedures and principles regarding compensation of the damages caused by nuclear incidents. Nuclear liability regime is fundamentally a result of international developments emerging in the nuclear energy field and a branch comprising rules regulated by states and/or international organizations. By this means, this regime becomes a junction point between national and international law principles. Throughout this paper, states’ liability or responsibility within the context of liability regimes will be analysed and discussed. In the first section, “nuclear liability” will be scrutinised and in the second section, concepts of state responsibility and state liability in case of a nuclear accident or radiological emergency with transboundary effects will be analysed and discussed under international law and under nuclear law.
An EPR study of clinoptilolite from Bigadiç in Turkey
(Elsevier, 2016-01) Bıyık, Recep; Tapramaz, Recep; 0000-0001-7929-4395; TAEK-ÇNAEM
Natural and synthetic zeolites are industrial materials. They are used in many applications as food additives, molecular sieve to trap unwanted ingredients, as heavy metallic ions and groups, as shielding against radiations etc. EPR spectroscopy is a tool to characterize paramagnetic centers and radicals in the zeolite and clay type minerals. In this study natural cliptonilolite obtained from a mine in Bigadiç in western Anatolia, Turkey, was studied using electron paramagnetic resonance spectroscopy (EPR) at room temperature in natural form,following treatment of the samples: adsorbing of CO2, H2S, and SO2 gases, [Cu(H2O)6]2 ions and exposure to gamma rays. Mn atoms become paramagnetic Mn2+ ions when CO2 and H2S gases are adsorbed to clinoptilolite and when SO2 gas is adsorbed the system becomes unstable and the structure of the paramagnetic center changes with time. When Cu2+ ions are adsorbed to the Bigadiç clinoptilolite, the values of the EPR parameters are consistent with the distorted octahedral symmetry environment and after the exposure to gamma rays from a Co-60 source gives O23- radical.
An EPR study on tea: Identification of paramagnetic species, effect of heat and sweeteners
(Elsevier, 2009-10) Bıyık, Recep; Tapramaz, Recep; 0000-0001-7929-4395; TAEK-ÇNAEM
Tea (Camellia Sinensis) is the most widely consumed beverage in the world, and is known to be having therapeutic, antioxidant and nutritional effects. Electron paramagnetic resonance (EPR) spectral studies made on the tea cultivated along the shore of Black Sea, Turkey, show Mn2+ and Fe3+ centers in green tea leaves and in black tea extract. Dry black tea flakes and dry extract show additional sharp line attributed to semiquinone radical. The origins of the paramagnetic species in black tea are defined and discussed. Effect of humidity and heat are investigated. It is observed that dry extract of black tea melts at 100 ◦C and the semiquinone radical lives up to 140 ◦C while Mn2+ sextet disappears just above 100 ◦C in tea extract. Natural and synthetics sweeteners have different effects on the paramagnetic centers. White sugar (sucrose) quenches the Mn2+ and semiquinone lines in black tea EPR spectrum, and glucose, fructose, lactose and maltose quench Fe3+ line while synthetic sweeteners acesulfam potassium, aspartame and sodium saccharine do not have any effect on paramagnetic species in tea.
Application of CNUREAS and MCNP5 codes to VVER-1000 MOX core computational Benchmark
(Elsevier, 2015) Şentürk Lüle, Senem; Özdemir, Levent; Erdoğan, Adem; TAEK-ÇNAEM
In order to strengthen the nuclear design calculation capacity in Turkey, CNUREAS (Cekmece Nuclear Reactor System) was developed to provide easy usage of neutronic and thermal hydraulic nuclear codes included in the CNUREAS package. It was tested and used for research reactors and PWR type power reactors. Modifications were performed to add hexagonal geometry support taking into account VVER type reactors employing hexagonal fuel assemblies that will be built in Turkey. “VVER-1000 MOX Core Computational Benchmark” was used to test new features of the CNUREAS. The maximum deviation in effective multiplication factor results of CNUREAS was 0.7% with deterministic codes and 1.5% with Monte Carlo codes. It was concluded that CNUREAS can be used for neutronic calculations of VVER type power reactors with appropriate cross section libraries and deterministic and Monte Carlo techniques give comparable results when both provided with appropriate cross section libraries.
Assesment of Cyclotron Produced 64Cu Radionuclide with Monte Carlo Simulations
(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-05-15) Yıldırım, Aydın; Boztosun, İsmail
Physical yields and activities of theranostic radioisotope 64Cu were calculated via Monte Carlo simulations. Geant4 simulation toolkit is employed for the Monte Carlo calculations. The study is based on proton irradiation of solid targets at cyclotron facilities. Two types of target material were investigated: Nickel and Zinc. Also, two different target thickness and two beam angles were assessed in order to see the change of yields and activities. The optimum results were achieved at 150 μm thickness, 24 MeV beam energy and 5◦ beam angle for the nickel target, and 150 μm thickness, 30 MeV beam energy and 5◦ beam angle for the zinc target.
Average glandular doses and national diagnostic reference levels in mammography examinations in Turkey
(Oxford University Press, 2020-05) Parmaksız, Aydın; Ataç, G. K.; Bulur, Emine; İnal, Tolga; Alhan, Aslıhan; AAH-5187-2020; 0000-0003-4000-5175; TAEK-Radyasyon ve Hızlandırıcı Teknolojileri Dairesi Başkanlığı
In order to establish National Diagnostic Reference Levels (DRLs) for mammography examinations, Entrance Skin Air Kerma (ESAK), Entrance Skin Dose (ESD) and Average Glandular Doses (AGDs) were calculated for a total of 25624 cranio-caudal (CC) and mediolateral oblique (MLO) projections of 6309 patients for 40-49 and 50-64 age groups. The average ESAK and ESD values for both age groups were found to be higher in MLO projections compared to CC projections. The minimum and maximum values of AGDs were determined as 0.4 mGy and 7.9 mGy for both projections. The maximum numbers of AGDs for CC and MLO projections were calculated in the range of 1.1-1.5 mGy and 1.6-2.0 mGy respectively. The third quartile values of AGDs were calculated for each compressed breast thickness (CBT) between 20 mm and 99 mm. The first National DRLs of the country were established for each 10 mm CBT in mammography examinations.
Bakliyat ürünlerinde böceklenmeye karşı ışınlama teknolojisi
(Akdeniz İhracatçı Birlikleri, 2012-01) Aylangan, Ayça; Özyardımcı, Berna; İç, Erhan; TAEK-SANAEM
Gıda ışınlama baklagil ticaretinde karşılaşılan böceklenme problemlerini çözen, hem depolanmış hem de taze tarım ürünlerine uygulanabilen, etkinliği kanıtlanmış bir teknolojidir. Böceklenmeyi önlemek amacıyla kullanılan düşük ışınlama dozları üründe kimyasal içerik ve besin değeri açısından önemli bir değişikliğe yol açmamaktadır. Tüketici tutumuna yönelik gerçekleştirilen araştırmalarda da olumlu sonuçlar alınmaktadır. Baklagil grubu gıdaların ışınlanmasında ürün ambalajı yeniden böcek bulaşmasını önleyecek şekilde seçilmelidir. Ayrıca, baklagil grubu gıdaların ışınlanması için gerekli tesisin çalışma özelliklerini de bu gıda ambalajlarının şekil ve büyüklüğü, ürün taşıma sistemi ve ışınlama kaynağının tipi belirlemektedir.
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, Belma
Unique 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.
Bitkilerde mutagen uygulamaları ile genetik çeşitliliğin artırılması ve sebze ıslahında kullanımı
(Gece Kitaplığı, 2021-12-25) Kökpınar, Şule; Kantoğlu, K. Yaprak; Ellialtıoğlu, Şeküre Şebnem; https://orcid.org/ 0000-0002-7247-9116; TENMAK-Nükleer Enerji Araştırma Enstitüsü-Ankara
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, Sema
The 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.
Callus and suspension culture techniques optimized for use in carrot breeding studies (Daucus carota ssp. sativus var. atrorubens alef and D. carota)
(TAGEM, 2023-02-02) Büyükdinç Turan, Damla; Kantoğlu Kadriye Yaprak; Karataş, Arzu; Ellialtıoğlu, Şebnem
In this study, studies were conducted to optimize callus and suspension culture methods for in vitro mutation breeding in purple and orange carrots. Following this, the developed mutant lines were subjected to in vitro salt stress selection. The study determined the optimal agar dose. The first germination, 50% germination, rootcotyledon formation and genuine leaf formation in carrot seedlings were analyzed daily in the study, which was continued with the determined 7g/L agar dose. The cotyledon and hypocotyl explants from the seedlings were cultivated for callus production in mixtures of MS-1, MS-2 and MS-3 nutritional medium. In the second and fourth weeks following the second subculture, callus production percentages and weights were measured. The MS-3 (1 mg/L 2,4-D + 0.5 mg/L kinetin) nutritional medium and hypocotyl explant were found to be particularly effective at producing callus. The second subculture's data on the number of plants that had successfully regenerated per callus, showed that the MS nutritional medium with 0.2 mg/L Thidiazuron (TDZ) was the best medium for plant regeneration. The dispersed calli were grown in a nutritional medium designed for suspension culture in a nutrient medium mixture comprising MS+0.1 mg/L kinetin. The results obtained with the optimization steps were used in the ongoing study.

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