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Öğe Eco-Geopolymers: Physico-Mechanical Features, Radiation Absorption Properties, and Mathematical Model(Mdpi, 2022) Dogan-Saglamtimur, Neslihan; Bilgil, Ahmet; Erturk, Sefa; Bozkurt, Vakkas; Suzgec, Elif; Akan, Arife Gozde; Nas, PervinWaste ashes and radiation are hazardous environmental and health factors; thus, a lot of attention is paid to their reduction. We present eco-geopolymer building materials (GPBMs) based on the class F fly ashes (FFAs) from thermal power plants (TPPs) and their implementation as a barrier against radioactive radiation. Different methods of production, ratios of FFA to alkali activator, and temperatures of curing were tested. Small spherical particles and higher content of SiO2 resulted in developed surface area and higher reactivity of Isken TPP FFA than Catalagzi TPP FFA. Lower activator concentration (10% vs. 20%) and curing temperature (70 vs. 100 degrees C) caused an increase in GPBM compressive strength; the highest value was measured as 93.3 MPa. The highest RA was measured for GPBMs, provided alkali activator ratio (Na2SiO3/NaOH) was >2 and its concentration was 20%. The mathematical model developed in this study proved FFA quantity, and thus GPBM mechanical properties, as key factors influencing RA. In the light of these results, the lightweight GPBMs can be excellent materials for the construction sector dedicated to immobilization, storage, and disposal for radionuclides or barriers against radiation; however, multiple steps of their production require careful optimization.Öğe Evaluation of radon gas concentration in indoor air of spas and in spring water in the central Anatolia region of Turkey(Springer, 2022) Bozkurt, Vakkas; Erturk, SefaThe present study aimed to determine the concentration of radon (Rn-222) levels of indoor air of spas and of spring water sites in the Turkish cities of Nigde and Aksaray, both located in Cappadocia, Anatolia, which is a well-known tourist area. In this area there are a lot of spring water and thermal water sites providing both drinking water and water for spas, which are used for therapeutic treatments of diseases and for health services. Therefore, it is necessary to quantify radon gas concentrations in the air of sites that use geothermal waters and spring water. Consequently, radon measurements were carried out using CR-39 detectors placed at different locations within each investigated thermal spa and spring water site. The results obtained indicate that, in the air of spring water at Helvadere, there is a high radon concentration. The average radon concentrations obtained for the air of Ciftehan and Ziga thermal spas were 12.5 +/- 1.4 Bq/m(3) and 15.5 +/- 2.1 Bq/m(3), respectively, while in the air of Kemerhisar, Helvadere, and Okcu village spring water sites the average radon concentrations were 32 +/- 4.2 Bq/m(3), 265 +/- 37.9 Bq/m(3), and 35 +/- 5.1 Bq/m(3), respectively. The corresponding average effective doses were calculated both for patients and workers for Ciftehan and Ziga thermal spas, and for workers 0.09 and 0.11 mSv/year for Ciftehan and Ziga, respectively, were obtained. Doses for patients were 0.0007 and 0.0008 mSv/year for Ciftehan and Ziga, respectively. It is concluded that based on the measured radon concentrations and corresponding effective doses no radiation protection measures must be implemented.Öğe Geopolymer's radiation absorption detected by Geiger-Muller counter(Iop Publishing Ltd, 2019) Suzgec, Elif; Dogan-Saglamtimur, Neslihan; Bozkurt, Vakkas; Erturk, SefaFly ash (FA), which is an industrial solid waste released by the burning of coal in thermal power plants, is responsible for causing environmental problems. Radiation is also an environmental problem besides causing health problems for human being. Geopolymer is a specialized building material resulting from the reaction of a source material, which is rich in silica and alumina, with alkaline solution. It is ordinary Portland cement (OPC) free building material. It has been reported that geopolymer building material has good engineering properties with a reduced carbon footprint resulting from the total replacement of OPC as greener alternative. In this study, it is aimed to measure radiation absorption of geopolymers produced from the reaction of FA, which was supplied from Isken Sugozu Thermal Power Plant (Adana, Turkey) and rich in silica and alumina in total content of 83.74, with alkaline activators (sodium hydroxide and sodium silicate) at curing temperatures (70 degrees C and 100 degrees C). In the study, lattice measurement system consisting of nested lead plates to avoid unwanted radiation was designed to determine radiation absorption of geopolymers. By using this new system, geopolymer was found to be 5% better radiation absorption capacity than OPC building material when it is compared.Öğe Nuclear Data Sheets for A=84(Academic Press Inc Elsevier Science, 2009) Abriola, Daniel; Bostan, Melih; Erturk, Sefa; Fadil, Manssour; Galan, Monica; Juutinen, Sakari; Kibedi, TiborThe evaluated spectroscopic data are presented for 12 known nuclides of mass 84 (Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo). Except for the stable nuelides Sr-84 and Kr-84, extensive new data are available for all the other nuclides since the 1997 evaluation by J.K. Tuli (1997Tu02) of A=84 nuclides. Many precise Penning-trap mass measurements since AME-2003 for A=84 nuclides (2009Re03,2008Ha23,2008We10,2007Ke09,2006Ka48, 2006De36,2006Ri15) have resulted in improved Q values and separation energies. However, many deficiencies still remain. Some examples are given below. Excited-state data for Ga-84 and As-84 are nonexistent, and those for Ge-84 are scarce, The radioactive decay Schemes of Ga-84, Ge-84, Se-84, Y-84 (39.5 min), Y-84 (4.6 s), Zr-84 and Nb-84 suffer from incompleteness and that for Mo-84 decay is not known at all. The energy ordering of the two activities (39.5 min and and 4.6 8) of Y-84 is not well established, although, high-spin with tentative spin-parity of (6+) is adopted here as the ground State of Y-84 based on weak arguments. From a conference report published in 2000, it is clear that extensive experiments were done to investigate decays of Zr-84 and Y-84, but details of these studies never appeared in literature and none were made available to the evaluators when requested from original authors. This evaluation was carried out as part of ENSDF workshop for Nuclear Structure and Decay Data Evaluators, organized and hosted by the Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest, Romania during March 30, 2009 - April 3, 2009. Names of the evaluators principally responsible for evaluation of individual nuelides are given under the respective Adopted data sets.Öğe Yeni Geliştirilen NUMEXO2 Dijital Elektronik ile EXOGAM2 Dedektörünün K-Parametresine Bağlı Enerji Çözünürlüğü(2020) Bozkurt, Vakkas; Erturk, Sefa; Şahin, ElifBu çalışmada, yeni geliştirilen dijital elektronik NUMEXO2 ile EXOGAM2(EXOtic GAMma array spectrometer) dedektörünün K-Parametrelerine (sayım oranını optimize eden Trapezoidal filtre sistemi) bağlı enerji çözünürlüğü için 152Eu radyoaktif kaynak kullanılarak ölçüm ve analiz yapılmıştır. Yapılan bu deneysel çalışma Fransa’da bulunan GANIL (Grand Accelerature National d’Ions Lourd) nükleer araştırma merkezinde gerçekleştirilmiştir. Düşük ve yüksek gama enerji seviyesine sahip 152Eu radyoaktif kaynak kullanılarak farklı K-parametreleri için gerçekleştirilen ölçüm ve analiz sonuçları iki EXOGAM2 dedektörü için gerçekleştirilmiştir. Herhangi bir K-parametresi uygulamadan birinci EXOGAM2 dedektörü için FWHM ile ifade edilen çözünürlük değerleri sırası ile (344,278 keV) için 2,357, (1408,006 keV) için 2,820 olarak ölçülürken, ikinci EXOGAM2 dedektörü için ise sırasıyla 2,451 ve 2,975 olarak ölçülmüştür. Aynı yöntem kullanılarak farklı K-Parametrelerine (K=2µs, K=5µs ve K=10µs) bağlı olarak EXOGAM2 dedektörleri için enerji çözünürlükleri elde edilmiştir.
