Browsing by Author "Kaynar U.H."
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Item Removal of uranium(VI) from aqueous solutions using nanoporous ZnO prepared with microwave-assisted combustion synthesis(Kluwer Academic Publishers, 2014) Kaynar U.H.; Ayvacıklı M.; Kaynar S.C.; Hiçsönmez U.The adsorption of the uranyl ions from aqueous solutions on the nanoporous ZnO powders has been investigated under different experimental conditions. The adsorption of uranyl on nanoporous ZnO powders were examined as a function of the contact times, pH of the solution, concentration of uranium(VI) and temperature. The ability of this material to remove U(VI) from aqueous solution was followed by a series of Langmuir and Freunlinch adsorption isotherms. The adsorption percent and distribution coefficient for nanoporous ZnO powders were 98.65 % ± 1.05 and 7,304 mL g -1 , respectively. The optimum conditions were found as at pH 5.0, contact time 1 h, at 1/5 Zn 2+ /urea ratio, 50 ppm U(VI) concentration and 303 K. The monomolecular adsorption capacity of nanoporous ZnO powders for U(VI) was found to be 1,111 mg g -1 at 303 K. Using the thermodynamic equilibrium constants obtained at different temperatures, various thermodynamic parameters, such as ΔG, ΔH and ΔS, have been calculated. Thermodynamic parameters (ΔH = 28.1 kJ mol -1 , ΔS = 160.30 J mol -1 K -1 , ΔG = -48.54 kJ mol -1 ) showed the endothermic and spontaneous of the process. The results suggested that nanoporous ZnO powders was suitable as sorbent material for recovery and adsorption of U(VI) ions from aqueous solutions. © 2014 Akadémiai Kiadó, Budapest, Hungary.Item Removal of thorium (IV) ions from aqueous solution by a novel nanoporous ZnO: Isotherms, kinetic and thermodynamic studies(Elsevier Ltd, 2015) Kaynar U.H.; Ayvacikli M.; Hiçsönmez U.; Çam Kaynar S.The adsorption of thorium (IV) from aqueous solutions onto a novel nanoporous ZnO particles prepared by microwave assisted combustion was studied using batch methods under different experimental conditions. The effect of contact time, solution pH, initial concentration and temperature on adsorption process was studied. The ability of this material to remove Th (IV) from aqueous solution was characterises by Langmuir, Freunlinch and Temkin adsorption isotherms. The adsorption percent and distribution coefficient for nanoporous ZnO powders in optimum conditions were 97% ± 1.02; 8080 L kg-1for Th (IV), respectively. Based on the Langmuir model, the maximum adsorption capacity of nanoporous ZnO for Th (IV) was found to be 1500 g kg-1. Thermodynamic parameters were determined and discussed. The results indicated that nanoporous ZnO was suitable as sorbent material for recovery and adsorption of Th (IV) ions from aqueous solutions. The radioactive Th (VI) in surface water, sea water and waste waters from technologies producing nuclear fuels, mining (uranium and thorium) and laboratories working with radioactive materials (uranium and thorium) can be removed with this nanoporous ZnO. © 2015 Elsevier Ltd.Item Determination of 210Po and 210Pb depositions in lichen and soil samples collected from Köprübaşı-Manisa, Turkey(Springer, 2018) Çam Kaynar S.; Kaynar U.H.; Hiçsönmez U.; Sevinç O.S.In this study, we aimed to determine the accumulations of 210Po and 210Pb in soil and lichen samples in Köprübaşı. The Köprübaşı district is home to the largest uranium deposits in Turkey. To date, there has been no study recorded in the literature related to 210Po and 210Pb depositions in lichens in Köprübaşı. Six different lichen species (Cladonia convoluta, Parmelina tiliacea, Physcia stellaris, Pleurosticta acetabulum, Xanthoparmelia conspersa, and Xanthoria parietina) as well as soil samples were collected from seven sampling locations around Köprübaşı. Lichens were used as biomonitors for 210Po and 210Pb deposition. The 210Po and 210Pb activity concentrations were measured in all the samples by alpha spectrometry. The activity concentrations in the lichen samples ranged from 64 to 577 Bq kg−1 with an average of 266 Bq kg−1 for 210Po and from 78 to 565 Bq kg−1 with an average of 333 Bq kg−1 for 210Pb. The activity ratios of 210Po/210Pb ranged from 0.80 to 1.99. In the lichen species, the mean 210Po activity values varied from 154 Bq kg−1 in Pleurosticta acetabulum to 390 Bq kg−1 in Xanthoparmelia conspersa. The range of the mean 210Pb activity was between 153 Bq kg−1 in Cladonia convoluta and 378 Bq kg−1 in Parmelina tiliacea. In the soil samples, 210Po and 210Pb activity concentrations were ranged from 14 to 1268 Bq kg−1 and from 19 to 1113 Bq kg−1, respectively. While the values of 210Po and 210Pb measured in the lichen samples are comparable with those of the literature, the results of 210Po and 210Pb in the soil taken from the uranium mine are higher than the results of the literature studies. © 2018, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Chinese Nuclear Society, Science Press China and Springer Nature Singapore Pte Ltd.Item Adsorption of thorium (IV) by amorphous silica; response surface modelling and optimization(Springer Netherlands, 2018) Kaynar U.H.; Şabikoğlu İ.The amorphous SiO2 (200–300 nm) was synthesized as an absorbent and thorium adsorption of SiO2 was investigated using experimental and RSM method. The SiO2 particles were made for the adsorption of thorium from aqueous solutions, and characterized by particle size measurement, XRD and SEM. The adsorption of thorium process was optimized with RSM method. The correlation between four variables was modeled and studied. Under optimum conditions, the adsorption capacity of SiO2 particles was found to be 134.4 mg/g, the correlation coefficient (R2) and the F value was obtained 0.96 and 1.98 × 10−6, respectively. In addition, the adsorption isotherms were examined. © 2018, Akadémiai Kiadó, Budapest, Hungary.Item Studying of 210Po and 210Pb Deposition in Some Lichen Species in Manisa, Turkey(Springer New York LLC, 2018) Çam Kaynar S.; Kaynar U.H.; Sevinç O.S.; Hiçsönmez U.Lichens are very useful for monitoring of the radionuclide deposition because having a high efficiency capturing the radionuclides from the atmospheric fallout. In the present work, 210Po and 210Pb deposition in some lichen species were determined using an alpha spectrometer. Different lichens were collected around Demirci-Manisa and investigated their uses as biomonitor for 210Po and 210Pb deposition. The highest activity concentrations for 210Po and 210Pb were detected in Neofuscelia pulla (898 Bq kg−1 and 1207 Bq kg−1, respectively). The mean activities in the lichen species ranged from 164 to 584 Bq kg−1 for 210Po and from 175 to 671 Bq kg−1 for 210Pb. The activity ratios for 210Po/210Pb ranged from 0.75 to 1.57. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.Item Comprehensive study of photoluminescence and cathodoluminescence of Eu and Tb doped Mg2SiO4 prepared via a solid-state reaction technique(Elsevier B.V., 2020) Ucar Z.G.P.; Akca S.; Dogan T.; Halefoglu Y.Z.; Kaynar U.H.; Ayvacikli M.; Guinea J.G.; Topaksu M.; Can N.We report narrow-band green-red emitting Mg2SiO4 phosphors successfully synthesized through solid-state reaction method, and the cathodoluminescence (CL) and photoluminescence (PL) properties of the samples were investigated in detail. Under electron beam and 275 nm excitation, Mg2SiO4 phosphors doped with various Eu3+ and Tb3+ concentrations in the range of 1 mol % up to 10 mol % exhibit typical green and red emissions, respectively. Tb doped samples were efficiently excited by a low voltage electron beam and UV light, yielding several emission peaks between 370 and 760 nm, and produced a bright green light peaking at 541 nm due to the 5D4 →7F5 transition. Eu3+ doped samples exhibited CL and PL emission spectra from 5D0 to 7Fj manifold transitions of Eu3+. A strong red-light emission peaking at 610 nm also supports the incorporation of Eu3+ ions. A concentration quenching effect was observed and discussed for both phosphors. The optimal doping concentration of Eu3+ and Tb3+ doped phosphors was 7 mol %. In view of the outstanding performance in the PL and CL, the Mg2SiO4:Eu3+, Tb3+ can be considered as a promising green and red phosphor in solid-state lighting applications. © 2020 Elsevier B.V.Item Adsorption of thorium (IV) ions by metal ion doped ZnO nanomaterial prepared with combustion synthesis: Empirical modelling and process optimization by response surface methodology (RSM)(Elsevier Ltd, 2021) Kaynar U.H.; Çam Kaynar S.; Ekdal Karali E.; Ayvacıkli M.; Can N.Environmental problems have reached enormous dimensions, driving efforts to remove and recycle waste from energy and industrial production. In particular, removing the radionuclide contamination that occurs as the nuclear industry grows is difficult and costly, but it is vital. Technologic and economical methods and advanced facilities are needed for the separation and purification of radioactive elements arising from the nuclear industry and uranium and thorium mining. With the adsorption method, which is the most basic separation and recovery method, the use of high-capacity nanomaterials has recently gained great importance in reducing the activity of the waste, reducing its volume by transforming it into solid form, and recovering and removing liquid radioactive wastes that might harm the ecological environment. This study aimed to determine the adsorption properties of metal ion-doped nano ZnO (nano-ZnO:Al) material synthesized by the microwave-assisted gel combustion method for the adsorption of thorium (IV) from aqueous media. First, characterization processes such as XRD, SEM, BET and zeta potential were performed to observe changes in the host ZnO adsorbent structure caused by the doping process. Later, this was optimized via the response surface method (RSM), which is widely used in the characterization of the adsorption properties of thorium (IV) from aqueous solutions. Such characterization is commonly used in industrial research. We tested how pH (3–8), temperature (20–60 °C), Th (IV) concentration (25–125 mg/L) and adsorbent amount (0.01–0.1 g) affect adsorption efficiency. The best possible combinations of these parameters were determined by RSM. It was calculated by RSM that the design fits the second order (quadratic) model using the central composite design (CCD) for the design of experimental conditions. R2 and R2 adjusted values from the parameters showing the model fit were 0.9923 and 0.9856, respectively. According to the model, the experimental adsorption capacity was 192.3 mg/g for the doped-ZnO nanomaterial under the theoretically specified optimum conditions. Also, the suitability of Th (IV) adsorption to isotherms was examined and thermodynamic parameters were calculated. © 2021 Elsevier LtdItem Synthesis and photoluminescence characteristics of a novel Eu and Tb doped Li2MoO4 phosphor(Elsevier Ltd, 2021) Souadi G.; Kaynar U.H.; Ayvacikli M.; Coban M.B.; Oglakci M.; Canimoglu A.; Can N.Li2MoO4:x Eu3+ and Li2MoO4:xTb3+ phosphors, where x = 0.5, 1, 2, 3, 5 and 7 wt%, were synthesized through a gel-combustion method. The XRD data reveals that Eu3+ and Tb3+ doped Li2MoO4 phosphors exhibit a Rhombohedral structure belonging to the space group R3 which matched well with the standard JCPDS files (No.012-0763). We present photoluminescence (PL) spectra from Eu and Tb doped Li2MoO4 under 349 nm Nd:YLF pulses laser excitation over the temperature range of 10–300 K. Undoped Li2MoO4 shows a wide broad band around 600 nm because of the intrinsic PL emission of tetrahedral of MoO42− which was in good agreement with previous findings. Under the excitation of 394 nm, the as-synthesized phosphors exhibited sharp and strong intensity PL emission signals in the red (612 nm, 5D0→7F2 transition) and green (544 nm, 5D4→7F5 transition), respectively. The critical doping concentration of Eu3+ and Tb3+ ions in the Li2MoO4 were estimated to be 2 wt%. The concentration quenching phenomena were discussed, and the critical distances for energy transfer have also been evaluated by the concentration quenching. © 2021 Elsevier LtdItem Thermoluminescence study and evaluation of trapping parameters of samarium doped barium silicate phosphor(Taylor and Francis Ltd., 2021) Alajlani Y.; Oglakci M.; Kaynar U.H.; Ayvacikli M.; Portakal-Uçar Z.G.; Topaksu M.; Can N.We report the detailed analysis of thermoluminescence (TL) glow curves and the evaluation of kinetic parameters of Sm3+-incorporated BaSi2O5.The effect of various heating rates on TL kinetics and glow peak temperatures of Sm3+-doped BaSi2O5 phosphors exposed to beta particle irradiation at room temperature are investigated. The glow curve of the phosphor exposed to β-irradiation consists of two main peaks with maxima at about 91°C and 193°C and exhibits good linearity between 1 and 10 Gy. The activation energies and frequency factors of trap centers involved in the TL emission were calculated from the TL glow curve of the sample by means of variable heating rate (VHR), repeated initial rise (RIR), and computerized glow-curve deconvolution (CGCD). Analysis of the main dosimetric peak techniques indicate that activation energies (E) and pre-exponential factor (s) vary between 0.93 and 1.72 eV, 1010 and 1013 s−1. It is found that the temperature of the glow peaks shifts toward the higher temperatures and the TL intensity smoothly decreases as the heating rate increases. The behavior of the TL intensities and glow peak temperatures as a function of the heating rate are discussed with regards to thermal quenching. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of The Korean Ceramic Society and The Ceramic Society of Japan.Item Thermoluminescence glow curve analysis and evaluation of trapping parameters of dysprosium doped lanthanum calcium borate La2CaB10O19(Elsevier B.V., 2021) Bulcar K.; Oglakci M.; Kaynar U.H.; Ayvacikli M.; Souadi G.; Topaksu M.; Can N.The present work elucidates thermoluminescence study of Dy activated lanthanum calcium borate (La2CaB10O19) phosphors and determination of trapping parameters. Two glow curves located at 132 and 295 °C were observed and showed a linear TL response. The kinetic parameters of the glow peaks were evaluated using variable heating rate, repeated initial rise method and Computerized Glow Curve Deconvolution. Analysis of the main dosimetric peaks reveals that the values of the activation energy and pre-exponential factor are found to be 0.78–1.145 eV and 8.59 × 109–8.44 × 1011 s−1, respectively. The sample doped with 1% Dy3+ exhibits a good stability for the reusability. Besides, the found results indicate that the temperature maximum shifts to the higher temperature side as the heating rate increases. Contrary to previously expressed theoretical expectations, anomalous heating rate dependence was observed in Dy3+ doped La2CaB10O19 sample and a semi-localized transition model explaining the anomalous heating rate effect was employed. © 2020 Elsevier B.V.Item Synthesis and enhanced photoluminescence of the BaSiF6:Dy3+ phosphors by Li+ doping via combustion method(Elsevier B.V., 2022) Souadi G.; Kaynar U.H.; Ayvacikli M.; Canimoglu A.; Can N.Undoped BaSiF6, Dy3+ doped BaSiF6, and Dy3+, Li+ co-doped BaSiF6 phosphors were synthesized through a gel-combustion method. The prepared samples were characterized by powder x-ray diffraction (XRD), Fourier transform infrared (FTIR), energy dispersive x-ray spectroscopy (EDS), and photoluminescence (PL) techniques. The XRD data revealed that both the Dy3+ doped and Li + co-doped BaSiF6 phosphors exhibited a single-phase structure belonging to the space group R3m‾ which matched well with the standard JCPDS files (No. 002–6613). FTIR spectra showed absorption bands at 3417 cm−1, 1640 cm−1, and 1620 cm−1 corresponding to water molecules. EDS analysis confirmed the chemical composition of the prepared samples. The PL emission spectra of BaSiF6:Dy3+ by different co-doping concentrations of Li+ exhibited prominent emission peaks at 490 nm, 572 nm, 672 nm and 758 nm. The incorporation of Li+ is beneficial for enhancing the photoluminescence intensity. The optimum Li+ amount was 8% for BaSiF6:Dy3+ and then started to decrease. The enhancement could be due to the occurrence of oxygen vacancies due to the incorporation of Li + ions. The x = 0.301 and y = 0.361 coordinates of this phosphor with varying Li+ dopant concentration determined by the Commission Internationale de l'Eclairage (CIE - 1931) were in the white range. The present work demonstrates how a simple and effective method can be used to prepare novel nanophosphors for applications in the field of visible light emitting devices with enhanced white emission. © 2021 Elsevier B.V.Item Samarium doped Ca3Y2B4O12 phosphor prepared by combustion method: Anomalous heating rate effect, dosimetric features, and TL kinetic analyses(Elsevier B.V., 2022) Hakami J.; Oglakci M.; Portakal-Uçar Z.G.; Sonsuz M.; Kaynar U.H.; Ayvacikli M.; Topaksu M.; Can N.The structural and thermoluminescence characteristics of samarium doped Ca3Y2B4O12 samples at various concentrations are presented. The samples were synthesized via the combustion method. The thermoluminescence (TL) glow curves for Ca3Y2B4O12:Sm3+ depict strong peaks at 97 and 410 °C. Ca3Y2B4O12:Sm3+ exhibited completely opposite behavior, contrary to expectations, in that the luminescence intensity of both the total and individual glow peaks increased with the heating rate throughout the TL experiments. This unusual TL glow peak pattern was discussed via the Mandowski model of semi-localized transitions. The kinetic characteristics of both prominent glow peaks were established using various analysis techniques, including variable heating rate, initial rise (IR) by using the TM-Tstop method and the fractional glow technique (FGT), and computerized glow curve deconvolution (GCD). The dose response of the high temperature peak at 410 °C is linear between 0.1 and 5 Gy, and then sublinear at higher doses. In addition, the repeatability and fading results of 410 °C TL peak also yielded very favorable results. These findings suggest that Ca3Y2B4O12:Sm3+ has great potential in the development of high temperature dosimetric materials for beta irradiation. © 2022 Elsevier B.V.Item Thermoluminescence glow curve analysis and kinetic parameters of Eu doped Li2MoO4 ceramic phosphors(Elsevier Ltd, 2022) Souadi G.; Oglakci M.; Kaynar U.H.; Correcher V.; Benavente J.F.; Bulcar K.; Ayvacikli M.; Hiziroglu A.; Topaksu M.; Can N.; Karali E.E.LiMoO4: x Eu ceramic phosphors with x = 0.5, 1, 2, 3, 5, and 7 mol% were synthesized using a gel combustion method. X-ray diffraction (XRD) measurements confirmed a rhombohedral structure (space group R3) of synthesized compounds. Following irradiation with 50 Gy beta dose, the sample doped with 5 mol% Eu exhibited the highest integrated thermoluminescence (TL) intensity. In order to evaluate dose-response, samples were irradiated with beta radiation for 10–1000 Gy. TL intensity with 1000 Gy dose without saturation yielded the highest integrated value. Different methods were employed to determine the number of peaks, the trap structure, and the kinetic parameters of the thermoluminescence glow curve of Eu doped Li2MoO4: the Hoogenstraaten method, the Booth-Bohun-Parfianovitch method, the initial rise method (IR), combined with the TM-Tstop experiment, various heating rates (VHR), and glow curve fitting with two different software packages. Based on the glow curve deconvolution obtained using both software packages, the component TL glow peaks present in the complex glow curve are composed of well-isolated nine overlapping glow peaks. Two software packages have shown quite similar activation energies and frequency factors. © 2022 Elsevier Ltd and Techna Group S.r.l.Item Novel Dy incorporated Ca3Y2B4O12 phosphor: Insights into the structure, broadband emission, photoluminescence and cathodoluminescence characteristics(Elsevier Ltd, 2022) Qaisi A.H.; Kaynar U.H.; Ayvacikli M.; Garcia-Guinea J.; Alajlani Y.; Topaksu M.; Can N.This study reports cathodoluminescence (CL) and photoluminescence (PL) properties of undoped borate Ca3Y2B4O12 and Ca3Y2B4O12:x Dy3+ (x = 0.5, 1, 2, 3, 5, and 7) synthesized by gel combustion method. Micro-X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), CL and PL under electron beam and 359 nm pulse laser excitation, respectively were used to investigate characterization and luminescence studies of synthesized samples in the visible wavelength. As-prepared samples match the standard Ca3Y2BO4 phase that belongs to the orthorhombic system with space group Pnma (62) based on XRD results. Under electron beam excitation, this borate host shows a broad band emission from about 250 to 450 nm, peaked at 370 nm which is attributed to NBHOC. All as-prepared phosphors exhibited the characteristic PL and CL emissions of Dy3+ ions corresponding to 4F9/2→6HJ transitions when excited with laser at 359 nm. The CL emission spectra of phosphors were identical to those of the PL spectra. Concentration quenching occurred when the doping concentration was 1 mol% in both the CL and PL spectra. The underlying reason for the concentration quenching phenomena observed in the discrete orange-yellow emission peaked at 574 nm of Dy3+ ion-doped Ca3Y2B4O12 phosphor is also discussed. According to these data, we can infer that this new borate can be used as a yellow emitting phosphor in solid-state illumination. © 2022 Elsevier LtdItem Thermoluminescence characteristics of a novel Li2MoO4 phosphor: Heating rate, dose response and kinetic parameters(Elsevier Ltd, 2022) Souadi G.; Kaynar U.H.; Oglakci M.; Sonsuz M.; Ayvacikli M.; Topaksu M.; Canimoglu A.; Can N.Lithium molybdate (Li2MoO4) phosphor was synthesized by a gel combustion method and its thermoluminescence properties were studied with the irradiation of beta. Various Heating Rate (VHR), Initial Rise (IR), and Computerized Glow Curve Deconvolution (CGCD) methods were used to determine the kinetic parameters (activation energy E (eV), frequency factor s (s−1), and kinetic order b) of the visible glow peaks. According to the kinetic study, the TL glow curve is made up of seven separate peaks with activation energies of 1.05, 0.76, 0.40, 0.60, 0.78, 1.81 and 1.25 eV and these peaks follow general-order kinetics. The results clearly showed that undoped Li2MoO4 has a potential to be considered in dosimetric applications where high doses have to be monitored as in the case of clinical dosimetry. © 2022 Elsevier LtdItem Synthesis and beta particle excited thermoluminescence of BaSiF6 phosphor(Elsevier Ltd, 2022) Souadi G.; Akca-Ozalp S.; Ekdal Karali E.; Kaynar U.H.; Ayvacikli M.; Topaksu M.; Can N.BaSiF6 phosphor was synthesized by a gel combustion method. The crystalline size was found to be 54.17 ± 4.36 nm using Williamson-Hall (W–H) approximation. The TL data collected by means of a combination of a commercial BG39 and HC575/25 filters was studied to evaluate basic kinetic parameters. Three TL glow peaks of BaSiF6 phosphors are centered at around 84, 190 and 322 °C. Tm-Tstop, various heating rate (VHR) and computerized glow-curve deconvolution (CGCD) method were utilized to analyse collected data. Our findings indicate that luminescence process in scrutinized material may obey second order kinetics. The TL dose response of the TL glow peaks exhibits a linear characteristic up to 100 Gy. Deconvolution of the glow curve reveals that the number of the component TL glow peaks in the complex glow curve is composed of well-isolated six overlapping glow peaks. The FOM value is 2.32. © 2021Item Thermoluminescence glow curve analysis of Ca3Y2B4O12 phosphor prepared using combustion method(Elsevier Ltd, 2022) Hakami J.; Sonsuz M.; Kaynar U.H.; Ayvacikli M.; Oglakci M.; Yüksel M.; Topaksu M.; Can N.Ca3Y2B4O12 (CBYO) phosphor was synthesized using a gel combustion method. X-ray diffraction (XRD) measurement confirmed a single-phase structure (space group Pnma (62)) of synthesized compound. TL measurements were conducted between room temperature (RT) and 450 °C at a heating rate of 2 °Cs−1. Significant glow peaks were observed at 64, 116, and 242 °C in CYBO phosphor sample exposed to different beta doses. In the range of 0.1–100 Gy, the TL intensity of the glow peak displayed good linearity. Different methods were employed to determine the number of peaks, the trap structure, and the kinetic parameters of the thermoluminescence glow curve of CBYO; the Hoogenstraaten method, various heating rates (VHR), and glow curve deconvolution method (CGCD) implemented through tgcd:An R package. Currently available findings confirm that CYBO host is a promising candidate for environmental studies because one exhibits adequate TL dose response coupled with a good sensitivity and linearity. © 2022 Elsevier LtdItem Thermoluminescence characterization and kinetic parameters of Dy3+ activated Ca3Y2B4O12(Elsevier B.V., 2022) Hakami J.; Sonsuz M.; Kaynar U.H.; Ayvacikli M.; Oglakci M.; Topaksu M.; Can N.In this study, thermoluminescence (TL) characteristics of Ca3Y2B4O12:xDy (0 ≤ x ≤ 0.07) phosphor samples were studied. The samples were exposed to beta irradiation in the dose range from 0.1 Gy to 100 Gy to investigate TL dose response. The concentration of Dy3+ in Ca3Y2B4O12 phosphor was optimized and found to be 1 mass % in terms of TL signal quality. The TL glow curve appears to be consisted of three peaks which were discernible at 72 °C, 280 °C and 376 °C. The trapping parameters (E, b, and s) were calculated using initial rise (IR), and variable heating rate (VHR) techniques. The trapping parameters, order of kinetics, frequency factor, and figure of merit have been all determined by means of the Glow Curve Deconvolution (GCD) method (tgcd:An R package). Ca3Y2B4O12:Dy phosphor displays efficient thermoluminescence properties. © 2022 Elsevier B.V.Item Adsorption of thorium (IV) ions using a novel borate-based nano material Ca3Y2B4O12: Application of response surface methodology and Artificial Neural Network(Elsevier Ltd, 2023) Kaynar U.H.; Kaptanoglu İ.G.; Cam-Kaynar S.; Ugurlu O.; Yusan S.; Aytas Ş.; Madkhli A.Y.; Can N.Since nuclear wastes are the most important wastes in terms of health and the environment, they are evaluated differently within nuclear reactors as well as in terms of their use in medical and industrial applications. In some cases, emergency intervention is necessary due to the amount of radioactivity or the physical and/or chemical conditions. The purpose of this study is to investigate the adsorption properties of nano Ca3Y2B4O12 (CYBO) material synthesized by the sol-gel combustion method for the adsorption of Thorium (IV) from an aqueous medium. We tested how pH (3–8), the concentration of Th (IV) (25–125 mg/L), amount of adsorbent value (0.005–0.08 g) and temperature (20–60 °C), affect adsorption efficiency. The best possible combinations of these parameters were examined by Response Surface Methodology (RSM) and Artificial Neural Network (ANN). R2 values for RSM and ANN were 0.9964 and 0.9666, respectively. According to the models, the adsorption capacity under the optimum conditions determined for the RSM and ANN model was found to be 134.62 mg/g and 125.12 mg/g, respectively. © 2022 Elsevier LtdItem Enhancement of luminescence and thermal stability in Eu3+-doped K3Y(BO2)6 with Li+ and Na+ co-doping(Elsevier B.V., 2024) Kaynar U.H.; Aydin H.; Altowyan A.S.; Hakami J.; Coban M.B.; Ayvacikli M.; Ekdal Karali E.; Canimoglu A.; Can N.Eu3+-doped and Li+/Na+ co-doped K3Y(BO2)6 (KYBO) phosphors were synthesized through a microwave-assisted sol–gel method, and their structural and photoluminescent (PL) characteristics were examined. X-ray diffraction (XRD) and Rietveld refinement confirm effective dopant incorporation and preservation of the crystalline structure. Fourier Transform Infrared (FTIR) spectroscopy indicates the maintenance of the borate structure, confirming the structural integrity of the phosphors upon doping. The addition of Li+ and Na+ co-dopants notably enhances luminescent efficiency and thermal stability, making these phosphors promising candidates for solid-state lighting (SSL) applications. PL analysis reveals strong red emission peaks at 612 nm, attributed to the 5Do → 7F2 transition of Eu3+ ions. The study indicates that electric dipole-quadrupole interactions are the primary mechanism for energy migration, with a critical distance of approximately 22.68 Å. This mechanism contributes to concentration quenching at higher doping levels. High temperature PL measurements indicated an activation energy of 0.1389 eV for thermal quenching in the Li+ co-doped sample. Additionally, the Na+ co-doped sample exhibited an abnormal thermal stability behavior, with an even higher activation energy of 0.2536 eV. This suggests that Na+ co-doping significantly enhances the thermal resilience of the phosphor, making it more suitable for high-power light-emitting applications that operate under extreme conditions. CIE chromaticity diagrams highlight the potential for optimizing Eu3+ doping levels, combined with Li+ and Na+ co-doping, to improve luminescent performance and thermal stability for advanced SSL applications. © 2024 The Society of Powder Technology Japan