Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu Kurumsal Araştırma Arşivi

Kurum yayınları ve kurum çalışanlarının yayınları “Açık Erişim” kapsamında yayınlanmaktadır. Açık Erişim “evrensel nitelikteki bilimsel bilginin insanlığın yararına sunulması” amacını taşır. Tezler, konferans bildirileri ve sunumlar ile makaleler kurum çalışanları tarafından sisteme girilmektedir.Tezler için; YÖK'ten alınan görüş doğrultusunda tez sahibinin izin vermesi yeterlidir. Konferans bildirileri ve sunumların yayına gönderildiği son hali arşive konulabilir.Makaleler için ise; hakem onayından geçmiş, yayına gönderildiği son halinin (post-print) Açık Erişime sunulmasına yayıncılar %90 oranında izin vermektedir. Arşivde şu an 1.639 yayın bulunmaktadır, çalışma bitiminde bu sayı yaklaşık 2.000 yayın sayısına ulaşacaktır.

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EXPERIMENTAL AND THEORETICAL ASSESSMENT OF SELECTED POLLUTANTS TREATED WITH GAMMA RADIATION AND HYDROGEN PEROXIDE

(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu (TENMAK), 2024-11-28) Genç, Ayşenur; Ergun, Ece; Fitoz, Alper; Kantoğlu, Ömer; İnce, Mahir; Acar, Orhan

Degradation of ibuprofen, triclosan, diclofenac, and ketoprofen in real wastewater effluent by gamma radiation/hydrogen peroxide was investigated on the basis of removal efficiencies, G-values, and kinetics. Gamma irradiation was performed using a 60Co source irradiator in the presence of different concentrations of hydrogen peroxide. The analyses of the pollutants were performed before and after irradiation treatment using a Liquid Chromatography-Mass Spectrometry (LC-MS) system. The addition of 0.5% hydrogen peroxide resulted in an enhanced removal efficiency of the target pollutants (93.92% for ibuprofen, 99.47% for triclosan, 86.65% for diclofenac, and 86.32% for ketoprofen) compared with the performance of the gamma irradiation process alone. The rate constants (k) of ibuprofen, triclosan, diclofenac, and ketoprofen increased by 1.42, 2.38, 1.38, and 3.37 times with 0.5% hydrogen peroxide addition, respectively. Moreover, the 90% decomposition of the target pollutants was achieved at lower doses in the gamma-ray/hydrogen peroxide system in comparison with the gamma treatment without hydrogen peroxide. Fukui functions and dual descriptor were calculated using density functional theory (DFT) to investigate the sensitivity of the target pollutants to hydroxyl radical attacks, to identify the initial reaction pathway, and to predict the degradation by-products. The findings were consistent with literature mechanisms and observed by-products.

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Shielding effect of boron carbide-tungsten carbide-aluminum metal matrix hybrid composite against different type of radiations

(SSRN, 2024-11-12) AKKAS, Ayhan; TUGRUL, A. Beril; TAZEGUL, Onur

The present study examined the shielding effect of composite materials containing varying proportions of aluminum, boron carbide and tungsten carbide compounds against different radiation types. The transmission technique was used to investigate the attenuation properties of the materials against gamma, beta and neutron radiation. The linear and mass attenuation coefficients of the samples were determined by 0.059 MeV (Am-241), 0.662 MeV (Cs-137) and 1.25 MeV (Co-60) energetic gamma rays and Emax = 2.25 MeV energetic beta rays. Furthermore, the total macroscopic cross section (T) was calculated for the materials in the presence of the Pu-Be neutron source. The gamma mass attenuation coefficient values were compared with theoretical values obtained from the XCOM programme code. Calculations of the half-value thickness (HVT) were conducted utilising linear attenuation coefficient and total macroscopic cross-section values. The results demonstrated that an increase in the tungsten carbide content of the materials resulted in an enhancement of the HVTs against gamma and beta radiation from Am-241, Cs-137 and Co-60. Furthermore, an increase in the boron carbide ratio resulted in an enhancement of the HVTs against the Pu-Be neutron source. The findings of this study may prove useful in the selection of effective shielding materials against mixed radiation in nuclear industries.

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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.Sibel

The 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.

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Radyonüklid Bakımından Zengin Plaj Kumlarının Mineralojik Bileşiminin Değerlendirilmesi, Geyikli-Çanakkale (Batı Anadolu) Assessment of mineralogical composition of the natural radionuclide rich beach sands in Geyikli, Çanakkale (Western Anatolia)

(Hacettepe Üniversitesi Yerbilimleri Uygulama ve Araştırma Merkezi Bülteni (Bulletin of the Earth Sciences Application and Research Centre of Hacettepe University, 0021-11-24) GÜLMEZ, FATMA; YILDIRIM, AYDIN; ŞİŞMAN TÜKEL, FATMA; ÜNAL ERCAN, HATİCE; ÖRGÜN TUTAY, YÜKSEL; KARACIK, ZEKİYE

Bu çalışma, Batı Anadolu'da Kestanbol plütonunu da bulunduran Miyosen yaşlı Ezine-Ayvacık magmatik kompleksinin kıyısı boyunca uzanan sahilde gözlenen radyonüklid bakımından zengin plaj kumlarının mineralojik bileşimini ele almaktadır. Sahil boyunca radyonüklitlerin plaj kumlarındaki dağılımı düzensizdir. Hantepe plajında en yüksek 238U ve 232Th serisi spesifik aktiviteleri gözlenirken, 40K spesifik aktivitesi orta düzeydedir. Buna karşılık, olasılıkla Kestanbol plütonundan türeyen malzemelerin ağırlıkta olduğu güneydeki plajlarda, Hantepe plajına kıyasla daha yüksek 40K ile daha düşük 238U ve 232Th serisi spesifik aktiviteleri gözlenmektedir. Bu çalışma kapsamında gama spektrometresi, tüm ve noktasal jeokimya analizleri kullanılmış, kum örneklerinin mineralojik bileşimi ve Kestanbol plütonuna ait felsik damar kayaçları ile nefelin monzogabro ve tefrifonolitik dayklar gibi farklı litolojilerinin radyonüklid konsantrasyonlarının değerlendirilmiştir. Sonuçlar, Hantepe plajındaki yüksek radyoaktivitenin kaynağının torit grubu mineraller olduğunu ve Kestanbol plütonunun pegmatitik damarlarının, bu minerallerin ana kayacı olduğunu ortaya koymuştur. Bununla birlikte, Miyosen magmatizmasının tüm ürünlerinin farklı seviyelerde radyoelement ve radyonüklid zenginleşmeleri sergilediği, diğer kayaç yapıcı ve aksesuar minerallerin de potansiyel olarak bölgedeki yüksek doğal arka plan radyasyonuna katkıda bulunduğu değerlendirilmiştir. This study investigates the mineralogical composition of radionuclide-rich beach sands along the coast of the Miocene Ezine-Ayvacık magmatic complex including Kestanbol pluton, in Western Anatolia. The distribution of the radionuclides shows variations along the coast with the highest recorded radioactivity at Hantepe Beach, where specific activities of the 238U-, and 232Th-series are significantly high, while 40K concentrations are moderate. In contrast, the southern beaches, dominated by material from the Kestanbol pluton, have higher 40K concentrations but lower 238U-, and 232Th-series specific activities than Hantepe beach. Using gamma spectrometry, bulk geochemical, and in-situ analyses, we provide a detailed assessment of the mineralogical composition of the sand samples and the primordial radionuclide concentrations of the different lithologies within the Kestanbol pluton, such as felsic veins, nepheline monzogabbro and tephriphonolitic dykes. We suggest that thorite group minerals control the high radioactivity at Hantepe beach, and pegmatitic veins of the Kestanbol pluton are the main source rock for thorite minerals. However, all the products of Miocene magmatism in the region exhibit elevated radioelement and radionuclide contents suggesting that other accessory and rock-forming minerals are the potential contributors to the high natural background radiation in the area.

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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.

Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu Kurumsal Araştırma Arşivi

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