Özbayoğlu, Gülhan
Loading...
Name Variants
Gulhan, Ozbayoglu
O.,Gulhan
O., Gulhan
Ö.,Gülhan
Ozbayoglu,G.
G., Ozbayoglu
Özbayoğlu,G.
G.,Özbayoğlu
Özbayoğlu, Gülhan
G.,Ozbayoglu
Ozbayoglu, Gulhan
Gülhan, Özbayoğlu
Ozbayoglu, G.
O.,Gulhan
O., Gulhan
Ö.,Gülhan
Ozbayoglu,G.
G., Ozbayoglu
Özbayoğlu,G.
G.,Özbayoğlu
Özbayoğlu, Gülhan
G.,Ozbayoglu
Ozbayoglu, Gulhan
Gülhan, Özbayoğlu
Ozbayoglu, G.
Job Title
Profesör Doktor
Email Address
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output
13
Articles
9
Citation Count
103
Supervised Theses
0
8 results
Scholarly Output Search Results
Now showing 1 - 8 of 8
Article Citation Count: 47The effect of synthesis and doping procedures on thermoluminescent response of lithium tetraborate(Elsevier Science Sa, 2011) Özbayoğlu, Gülhan; Yilmaz, A.; Ozbayoglu, G.; Energy Systems EngineeringLithium tetraborate has been a scientific focus since 1960s by the courtesy of the thermoluminescence property it possesses. Moreover, it is utilized in surface acoustic wave apparatuses, in sensor sector and in laser technology owing to its non-linear optical characteristics. For the uses in thermoluminescence dosimetry lithium tetraborate is activated by addition of a variety of metals as dopants. This study includes the synthesis of lithium tetraborate by two methods (high temperature solid state synthesis and water/solution assisted synthesis), doping of activators into the matrix material synthesized and characterization of the products. Lithium tetraborate is readily commercially available in TL (Themoluminescence) dosimetry; hence, the main aim in this study was to specify the effect of synthesis and doping methods on the TL response. The heating temperature for the synthesis was 750 degrees C and the retention time as selected as 4 h for both methods. The synthesis stages were followed by doping step where the compounds of Cu, Ag and In in different proportions were doped in lithium tetraborate by solid state and solution assisted doping techniques. Characterization of the product was achieved by X-ray diffraction (XRD). Fourier transform Infra Red Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) techniques. All samples prepared displayed TL response and the best TL signal was obtained from the sample produced by solid state synthesis and doped by solution assisted method with 0.1% Cu and 0.004% Ag. (C) 2010 Elsevier B.V. All rights reserved.Conference Object Citation Count: 5Synthesis, characterizations and investigation of thermoluminescence properties of strontium pyrophosphate doped with metals(Pergamon-elsevier Science Ltd, 2014) Özbayoğlu, Gülhan; Ozbayoglu, G.; Yilmaz, A.; Energy Systems EngineeringStrontium pyrophosphate, Sr2P2O7, was synthesized by solid-state synthesis method; the product was co-doped with copper-silver (Cu-Ag), copper-indium (Cu-In) and manganese-praseodymium (Mn-Pr) oxides (CuO, MnO, In2O3, Pr6O11 and AgNO3) by solid-state reaction method. The variation of dopant concentrations was investigated from 0.5 to 15% by weight. In addition to these processes, chemical characterizations of samples and the investigation of thermoluminescence (TLD) properties of strontium pyrophosphate with and without dopants were conducted. For the characterization; powder X-ray Diffraction (XRD) were implemented for phase purity of samples. Fourier Transform Infrared Spectroscopy (FTIR) was used to determine whether the bond structures were affected from the doping or not. Thermoluminescence (TLD) analyses were conducted on strontium pyrophosphate doped with different amounts of dopants for the first time. Glow curves showed that intensities were affected by different amounts of dopants. It can be concluded from that strontium pyrophosphate doped with 7% MnO and 1% Pr6O11 had the most powerful peak intensity around 160 degrees C and dosimetric property for promising application. (C) 2014 Elsevier Ltd. All rights reserved.Book Part Citation Count: 0Commercial coal preparation plants capability for the removal of trace elements(Springer International Publishing, 2016) Özbayoğlu, Gülhan; Energy Systems EngineeringIşiklar and Dereköy coal preparation plants clean lignite coals produced in Soma district. Run-ofmine coals contain trace elements and major elements that are associated with coal and inorganic matter. Trace elements are potentially harmful for human health and ecosystem. Physical coal cleaning is effective in reducing the concentration of many trace elements. In this study, the samples were collected from run-ofmine lignite (feed), coal preparation plant products, namely coarse (+18 mm) clean coal, fine (10-18mm, 0.5- 10mm) clean coals, middlings, coarse and fine refuses and slimes from the Dereköy and Işiklar plants systematically and chemical analyses of ash, trace and major elements were performed on each sample. Trace elements contents and distributions in each product were determined. During the cleaning of run-of-mine lignites in Işiklar and Dereköy coal preparation plants, 54.69% and 72.04% ash have been removed from the plants, respectively. Around 1/3 of Ga and Rb contents of Işiklar feed and more than 1/3 of Ga, Rb, Sr, contents of Dereköy feed could be removed by ash. Referring to major elements, rejection of 60% Ca and 53% Mg from Işiklar, and 69% Ca and around 80% Mg from Dereköy plants have been achieved. © Springer International Publishing Switzerland 2016.Article Citation Count: 0Removal of hazardous air pollutants based on commercial coal preparation plant data(oficyna Wydawnicza Politechniki Wroclawskiej, 2013) Özbayoğlu, Gülhan; Energy Systems EngineeringThis paper investigates the concentration, distribution, and rejection of hazardous air pollutants, specifically identified by the US Clean Air Act Amendments of 1990, based on commercial coal preparation plant data obtained on-site. The samples were collected from the products of the different cleaning circuits of the operating plant. The concentrations of twelve potentially hazardous trace elements, including As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Se, Th and U in those samples were determined. Compared with the average concentration of the trace elements in Turkish coals, the run-of-mine coal fed to the existing plant appears to contain higher concentrations of Cd, Hg, Mn, Th and V. However, the concentrations of As, Cd, Cr, Mn, Se, Th, U and V of the run-of-mine coal are above the world averages. Cd, Cr, Hg, Mn, Pb and Th concentrations of run-of-mine coal were easily removed at commercial coal preparation plant refuse in the range of 51.8% to 77.4 %, while only a small reduction was achieved for U and V as they were concentrated in clean coals. The present study reveals that conventional coal preparation technologies could significantly reduce hazardous air pollutants concentrations in coal.Article Citation Count: 10Removal of hazardous air pollutants based on commercial coal preparation plant data(2013) Özbayoğlu, Gülhan; Energy Systems EngineeringThis paper investigates the concentration, distribution, and rejection of hazardous air pollutants, specifically identified by the US Clean Air Act Amendments of 1990, based on commercial coal preparation plant data obtained on-site. The samples were collected from the products of the different cleaning circuits of the operating plant. The concentrations of twelve potentially hazardous trace elements, including As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Se, Th and U in those samples were determined. Compared with the average concentration of the trace elements in Turkish coals, the run-of-mine coal fed to the existing plant appears to contain higher concentrations of Cd, Hg, Mn, Th and V. However, the concentrations of As, Cd, Cr, Mn, Se, Th, U and V of the run-of-mine coal are above the world averages. Cd, Cr, Hg, Mn, Pb and Th concentrations of run-of-mine coal were easily removed at commercial coal preparation plant refuse in the range of 51.8% to 77.4 %, while only a small reduction was achieved for U and V as they were concentrated in clean coals. The present study reveals that conventional coal preparation technologies could significantly reduce hazardous air pollutants concentrations in coal.Article Citation Count: 5Potential of Removing Trace Elements from a Turkish Lignite(Taylor & Francis inc, 2010) Özbayoğlu, Gülhan; Energy Systems EngineeringLignite is a significant source for producing electricity in Turkey. However, the hazardous trace elements content, namely, vanadium (V), chromium (Cr), copper (Cu), arsenic (As), thorium (Th), and uranium (U), are much higher than those observed around the world. In this article, the potential of removing the trace elements from the Lignite obtained from the Soma mine using the gravity separation principles is discussed. The float-sink studies conducted using heavy liquid of 1.3 and 1.9 specific gravities identified that removal of the trace elements from the Soma lignite ranged from 15% to 83%.Article Citation Count: 18Synthesis and thermoluminescence properties of rare earth oxides (Y, Ce-Lu) doped lithium triborate(Elsevier Science Bv, 2011) Özbayoğlu, Gülhan; Ozbayoglu, Gulhan; Yilmaz, Aysen; Energy Systems EngineeringLithium triborate (LiB(3)O(5)) was synthesized by high temperature solid-state reaction method, and then rare earth oxides were doped into LiB(3)O(5) to enhance its thermoluminescent (TL) properties. The identification and characteristics of the obtained compounds were determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) analyses, differential thermal analyses (DTA) and scanning electron microscopy (SEM). The glow curves were obtained using a thermoluminescent (TL) reader. The results revealed that all the rare earth oxides were not good activators for lithium triborate and the obtained compounds could not be used for dosimetric applications.Article Citation Count: 18Comparison of Different Synthesis Methods to Produce Lithium Triborate and Their Effects on Its Thermoluminescent Property(Springer, 2010) Özbayoğlu, Gülhan; Ozbayoglu, Gulhan; Yilmaz, Aysen; Energy Systems EngineeringLithium triborate (LiB3O5) was produced by different synthesis methods, which included high-temperature solid-state reaction, microwave-assisted high-temperature solid-state reaction, and precipitation-assisted high-temperature solid-state reaction. After the synthesis, metal oxides (CuO and Al2O3) were doped into LiB3O5 to enhance its thermoluminescent (TL) properties, and the TL intensities were compared with each other. The identification and characteristics of undoped and doped LiB3O5 were determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) analyses, differential thermal analyses (DTA), scanning electron microscopy (SEM), and particle size analyzer. The glow curves were obtained by using a TL reader. The results showed that synthesis routes affected the physical and structural properties of lithium triborate, which have an important effect on its TL intensity.
