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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Determination of Effective Mutation Dose (ED50) To Be Used In Variety Treatment In Tea Plant

(Recep Tayyip Erdogan University Journal of Science and Engineering, 2025-07-29) Karaoğlu Göksu, Burcu; Kaçar Aka, Yıldız; Yazıcı, Keziban

Although tea is cultivated only in the Eastern Black Sea region of Türkiye, all tea plantations in the area have been established from seeds since the beginning of tea farming. This has negatively affected both yield and quality. The high level of heterozygosity in tea plants and the presence of self-incompatibility mechanisms prolong breeding efforts. Mutation breeding is used as a fast and practical method to induce genetic variation. In leading tea-producing countries such as China, India, Kenya, and Sri Lanka, commercially important tea cultivars have been developed through mutation breeding. However, no such studies have been conducted in Türkiye. This study aimed to determine the effective mutation dose that can be used to induce variation in tea plants. The research was conducted between 2020 and 2021 at the Tea Research Greenhouse of the Faculty of Agriculture, Recep Tayyip Erdoğan University. The plant material used was 3–4-node shoots of the Zihni Derin tea cultivar. These shoots were irradiated with 0, 10, 20, 30, 40, 50, 60, and 70 Gray (Gy) doses using the “Ob-Servo Sanguis Co-60 Research Irradiator” gamma irradiation device at the Turkish Energy, Nuclear and Mineral Research Agency. Single-node cuttings obtained from the irradiated shoots were planted in a peat-vermiculite mixture. Survival and rooting rates of the tea cuttings exposed to different gamma doses were recorded, and shoot length (mm) was measured in the growing tea seedlings. Survival and rooting rates decreased with increasing radiation dose. Based on a probit regression analysis of shoot length, the “Effective Mutation Dose” for tea was determined to be 11.45 Gy. This study represents the first mutation breeding research on tea in Türkiye and is expected to provide a foundation for future work in this field.

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Determination of the Effective Mutation Dose Through Physical Mutagen Application in Pearl Millet (Pennisetum glaucum L. cv. Heavri) for the Mutation Breeding Program

(Tekirdag Agricultural Faculty, 2026-03-16) Şenay, Ali

The problems caused by climate change have begun to significantly affect all areas of agricultural production. In particular, the increase in temperature and the resulting drought have become major issues for crop species, leading to an increase in annual yield losses. The advantages of millets (such as their nutritional value and high adaptability) are currently being considered in many countries as an alternative to crops that require more irrigation, especially due to the growing problem of drought. Various methods (classical breeding and biotechnological approaches) are being applied for millet breeding worldwide, and among these techniques, mutation breeding is one method that deserves particular attention. Countries that play an important role in millet production have initiated mutation breeding programs at the national and regional levels to increase nutrient content and enhance disease tolerance. In the present study, the ffective mutation dose was determined as a preliminary step to initiate mutation breeding research for pearl millet (Pennisetum glaucum L. cv. Heavri), which has been agronomically examined in Türkiye. For this purpose, millet seeds with 8% moisture content were irradiated with cesium-137 gamma rays, a physical mutagenic source, at seven different doses (0, 50, 100, 200, 300, 400, and 500 Gray). As a result of the plant measurements taken three weeks after irradiation and the linear regression analysis, 174 Gy was determined to be the effective mutation dose. The negative effects of increasing gamma ray doses on plant development were clearly determined on both shoot length and fresh plant weight, and the resulting difference was determined to be statistically important. The 10% lower and upper limits of the effective mutation dose were defined. Irradiation was conducted at doses of 150, 174, and 200 Gray to generate the M1 generation for the Heavri variety.

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Temperature Effects on Phase Evolution and Particle Morphology in Ce-Rich Commercial NdFeB Magnets During High-Pressure Hydrogen Decrepitation

(Turkish Energy, Nuclear and Mineral Research Agency (TENMAK), 2026-01-14) BILGIN, Salih; ARIK, M. Nasuh; SARITAS, Senem; ÇAKIR, Öznur

NdFeB magnets are essential to clean energy and advanced technological applications due to their superior magnetic properties. However, the availability of rare earth elements is susceptible to geopolitical and environmental challenges. The recycling of NdFeB permanent magnets from secondary sources represents a strategic approach to mitigate this supply risks associated with critical raw materials, particularly Neodymium (Nd) and Dysprosium (Dy). Among the available recycling techniques, Hydrogen Decrepitation (HD) has demonstrated significant potential for the efficient recovery of these elements from commercial magnets. This study investigates the effect of temperature during high pressure hydrogen decrepitation on the structural, microstructural, and compositional evolution of a commercial NdFeB magnet with relatively high Ce content, which is confirmed by inductively coupled plasma (ICP-OES) analysis provided baseline compositional data for the starting material. Experiments were performed at 9 bar hydrogen pressure under constant conditions of time, with three processing temperatures investigated (25 °C, 50 °C, and 75 °C). Scanning electron microscopy (SEM) of the initial magnet illustrated Ce-rich phases, while X-ray diffraction (XRD) confirmed the presence of CeFe2. According to XRD results, main RE2Fe14B phase transformed RE2Fe14BHx hydride phase after hydrogenation process. However, the CeFe2 peaks disappeared, indicating amorph phase transformation. In addition to hydride phase and CeFe2 phase, the presence Nd2O3 phase was detected. LECO elemental analysis was performed to quantify the amount of the oxygen and hydrogen inside hydrogenated powders. These results confirm the presence of oxide and hydrides with different amount. The results demonstrated that powders processed at 75 °C retained higher oxygen levels compared to those treated at 25 °C and 50 °C. This behaviour is attributed to less efficient hydrogen desorption and increased surface oxidation caused by extensive fragmentation. Furthermore, higher processing temperatures produced more agglomerated morphologies with limited cracking, lowering surface reactivity. Overall, the study highlights the effect of temperature on particle morphology, particle fragmentation, and oxidation behaviour during HD. These insights provide valuable guidance for the optimization of NdFeB magnet recycling and reprocessing strategies.

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Influence of Different Temperatures on Hydrogen Decrepitation of Scrap Hard Disk Drive NdFeB Magnets

(Turkish Energy, Nuclear and Mineral Research Agency (TENMAK), 2026-01-15) KAPLAN, Cansu; KAPLAN, Gizem; ÇAKIR, Öznur

Demand for rare earth elements (REEs) in NdFeB permanent magnets used in wind energy and EV necessitates efficient recycling to address supply chain vulnerabilities and environmental concerns. Hydrogen decrepitation (HD), hydrogen-assisted decrepitation process, offers a promising method for processing end-of-life Hard Disk Drive (HDD) NdFeB magnets by converting them into demagnetised powders while preserving microstructural integrity. This study investigates the impact on hydrogenation temperature (room temperature, 50°C, 75°C) on the recycling process at 4 bar hydrogen pressure and 2 hours. Chemical composition was determined by ICP-OES, oxygen and hydrogen contents by LECO analysis, phase identification by XRD with Rietveld refinement, and microstructure by SEMEDS. Results indicate that reduced temperatures promote hydrogen absorption, diminish oxidation, and produce finer particles characterised by typical intergranular fractures. XRD confirmed the formation of Nd₂Fe₁₄BHₓ phases with decreasing hydrogen content at elevated temperatures, along with an increased presence of Nd₂O₃ due to the exposure of reactive surfaces. According to these results, HD at room temperature under 4 bar is optimal for the effective and sustainable recycling of NdFeB magnets, eliminating the need for further heat treatment.

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NİKEL METAL HİDRİT PİLLERDEN NADİR TOPRAK ELEMENTLERİ VE KRİTİK ELEMENTLERİN KAZANIMI

(Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu, TENMAK, 2026-01-14) KOÇ DELİCE, Tülay; TÜRKER, Gülşah; KAYA, Yasemin; KUTLUATA, Onur Berk; ŞEŞEN, Halil; SEZEN, Büşra; ÖZSARI, Melike; ÖNAL, Mehmet Ali Recai; SOYDAŞ SÖZER, Belma

Günümüzde artan enerji talebi, enerji depolama ihtiyacı ve sürdürülebilirlik hedefleri, kritik ham maddelerin güvenilir kaynaklardan temin edilmesini zorunlu kılmaktadır. Kritik elementleri içeren enerji depolama uygulamalarında yaygın olarak kullanılan pil türleri lityum iyon ve nikel metal hidrit (NiMH) pillerdir. NiMH piller, elektrikli araçlar ve taşınabilir elektronik cihazlarda kullanılmaktadır. NiMH pillerin üretiminde kullanılan nikel ve nadir toprak elementleri (NTE) gibi stratejik metallerin, geri dönüşüm süreçleriyle tekrar kazanılarak ikincil ham madde kaynağı olarak değerlendirilmesi mümkündür. Bu bağlamda, şehir madenciliği yaklaşımıyla atık NiMH pillerin geri dönüşümü, hem çevresel açıdan atık yönetimine katkı sağlamakta hem de stratejik ham maddelerin arz güvenliği açısından kritik bir değer taşımaktadır. Bu çalışmada, öncelikle NiMH pillerden elde edilen “siyah kütle (black mass)” fraksiyonunun fiziksel ve yapısal karakterizasyonu gerçekleştirilmiştir. XRF ve XRD analizleri ile Ni(OH)₂, AB₅ tipi intermetalik hidrojen depolama alaşımları ve grafitik karbonun başlıca fazlar olduğu belirlenmiş; lazer kırınımına dayalı tane boyutu ölçümleri ise D₉₀ = 12,23 μm ve D₅₀ = 8,87 μm değerleriyle, numunenin yüksek özgül yüzey alanına sahip ince partiküllerden oluştuğunu ortaya koymaktadır. Bu morfolojik özellik, hidrometalurjik proseslerde çözünme kinetiklerini doğrudan etkilemekte ve metal kazanım verimini belirleyici bir faktör olarak öne çıkmaktadır. İçeriği belirlenen NiMH pil atığına sistematik liç deneyleri uygulanmış; sıcaklık, asit molaritesi ve sürenin liç verimine etkisi incelenmiştir. Sonuç olarak 0,5–2 M derişim aralığında ve 30–50 °C sıcaklıklarda Zn hariç Ni, Co, Mn, Ce, La ve Nd gibi diğer elementlerde %90’ın üzerinde çözünme verimi sağlanmıştır. Çalışmada ayrıca laboratuvar ölçeğinden pilot ölçeğe geçme amaçlı deneysel altyapı oluşturulmuş, bu kapsamda laboratuvar ölçeğinde elde edilen optimum parametreler yüksek hacimli liç işlemlerine uygulanmıştır. Bu sayede çalışmanın endüstriyel olarak uygulanabilirliği araştırılmıştır.

Türkiye Enerji, Nükleer ve Maden Araştırma Kurumu Kurumsal Araştırma Arşivi

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