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Öztürk, Asiye
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Name Variants
A.,Öztürk
O.,Asiye
Asiye, Ozturk
Ozturk,A.
A.,Ozturk
Ö.,Asiye
Öztürk,A.
Asiye, Öztürk
O., Asiye
Öztürk, Asiye
Ozturk, Asiye
A., Ozturk
O.,Asiye
Asiye, Ozturk
Ozturk,A.
A.,Ozturk
Ö.,Asiye
Öztürk,A.
Asiye, Öztürk
O., Asiye
Öztürk, Asiye
Ozturk, Asiye
A., Ozturk
Job Title
Öğretim Görevlisi
Email Address
asiye.ozturk@atilim.edu.tr
Main Affiliation
English Translation and Interpretation
Status
Former Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Sustainable Development Goals Report Points
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Scholarly Output
6
Articles
0
Citation Count
1
Supervised Theses
0
6 results
Scholarly Output Search Results
Now showing 1 - 6 of 6
Conference Object Citation - Scopus: 0Effect of Porosity on the Efficiency of Dssc Produced by Using Nano-Size Tio2 Powders(2014) Bilgin,N.; Park,J.; Ozturk,A.; Metallurgical and Materials Engineering; English Translation and InterpretationThe effect of porosity on the energy conversion efficiency of dye-sensitized solar cells (DSSCs) prepared by using pastes formed by mixing 20 nm and 200 nm TiO2 particles in different ratios is investigated. XRD and SEM analysis have been done to investigate the microstructure of pastes. The energy conversion efficiency of DSSCs was determined by drawing complete current density-voltage curve. The DSSC prepared using the mixture composed of 40 wt% 20 nm and 60 wt% 200 nm TiO2 particles maintained best energy conversion efficiency of 6.74%. The energy conversion efficiency of the DSSCs prepared by using pastes based on the mixture of two different size of TiO 2 particles is much better than that of the DSSCs prepared by using pastes composed of either only 20 nm or only 200 nm of TiO2 particles. The improved energy conversion efficiency is attributed to the establishment of further porous structure that lets more dye absorption from the surface through interior which provides enhancement of light absorption and multiple scattering.Conference Object Citation - Scopus: 0Production of Highly Efficient Photocatalytic Tio2 Powders by Mechanical Ball Milling(2013) Oztas,T.; Park,J.; Ozturk,A.; Metallurgical and Materials Engineering; English Translation and InterpretationHighly efficient photocatalytic TiO2 powders were prepared using a conventional ball mill with various milling times of 0, 12, 24 and 48 h. The photocatalytic activity of the prepared TiO2 powders was evaluated using the decomposition rate obtained by methylene blue (MB) solution and acetic acid gas under UV light irritation. After 24 h milling, the particle size decreased from 555 nm to 122 nm without changing any of the crystal structure. The photocatalytic TiO2 powders prepared by 24 h milling decomposed 94% of the methylene blue solution while the nonmilled TiO2 powders provided only 61% decomposition. After the removal of acetic acid gas, it took 1.5 h for the 24h-milled powders to decompose 100%, while the non-milled TiO2 showed 73% decomposition with same UV illumination duration. © (2013) Trans Tech Publications, Switzerland.Conference Object Citation - Scopus: 2Synthesis of Tio2 Nanostructures Via Hydrothermal Method(American Ceramic Society, 2015) Bilgin,N.; Agartan,L.; Park,J.; Ozturk,A.; Metallurgical and Materials Engineering; English Translation and InterpretationTitania (TiO2) nanostructures were produced via hydrothermal method using amorphous TiO2 powders synthesized by the sol-gel precipitation process. The hydrothermal system was isolated from the environment and hydrothermal reactions were allowed to execute at 130 °C for 36 h at autogeneous pressure, and at a stirring rate of 250 rpm. Scanning electron microscopy (SEM) analysis revealed that TiO2 nanofibers formed instead of nanotubes upon utilization of amorphous TiO2 precursor. After hydrothermal synthesis, the powders were acid treated by HCl several times. X-ray diffraction (XRD) analysis identified that the synthesized powders were Na-titanate and remained Na-titanate even after subjecting to acidic treatments several times. The photocatalytic performance of the powders was evaluated by degradation of methylene blue (MB) solution in UV illumination. Results were compared with nanotubes which were synthesized previously using P25 commercial titania powder and have shown that TiO2 in tubular structure offers better photocatalytic performance for the degradation of MB solution under UV illumination as compared to fiber-like structure. Copyright © 2015 by The American Ceramic Society. All rights reserved.Conference Object Citation - Scopus: 0Influence of Particle Size of Tio2 Powder on the Energy Conversion Efficiency of a Dye-Sensitized Solar Cell(2013) Bilgin,N.; Park,J.; Ozturk,A.; Metallurgical and Materials Engineering; English Translation and InterpretationDye-sensitized solar cells (DSSCs) have been fabricated using a TiO2 paste composed of mixtures of 25 nm and 250 nm TiO2 particles at various ratios. A maximum energy conversion efficiency of 6.7% has been achieved using the DSSC, based on a TiO2 layer composed of 40 wt% 25 nm and 60 wt% 250 nm TiO2 particles. The short-circuit current density, open-circuit voltage, and filling factor of the cell were 12.95 mA, 0.82 V, and 0.63, respectively. The overall performance of the DSSCs based on TiO2 layers composed using a mixture of two different sized particles is much better than that of either only 25 nm or only 250 nm TiO2 particles. It is recognized that adding the larger particles to the small particles in the TiO2 paste increases the dye absorption and light scattering effects of DSSC, resulting in a higher short-circuit current density and improved energy conversion efficiency. © (2013) Trans Tech Publications, Switzerland.Conference Object Citation - Scopus: 0Production of Potassium Titanate Whisker Reinforced Dental Composites(2014) Kapusuz,D.; Park,J.; Ozturk,A.; Metallurgical and Materials Engineering; English Translation and InterpretationPotassium titanate (K2O.nTiO2) whiskers (KTWs) were produced by sol-gel method and embedded into UDMA-TEGDMA resins to produce KTW reinforced composites that could be used for both anterior and posterior fillings. The effect Ti/K molar ratio on the chemical, structural and functional properties of the KTWs was investigated using XRD, HR-TEM, and BET analysis. Morphology and the surface properties of the KTWs rely on the Ti/K ratio. However, HR-TEM studies clarified that the KTWs grow along [110] axis regardless of Ti/K ratio. BET analysis revealed the presence of slit shaped meso-pores in the KTWs. The KTW reinforced composites were produced by mixing UDMA-TEGDMA resins at molar compositions of 30-70, 70-30, and 50-50 wt%, and by embedding 5 wt% KTW homogeneously into the mixtures. Photocatalytic activity of the KTWs and the KTW reinforced composites were evaluated through Methylene Blue degradation test. Photocatalytic activity of the composites decreased as Ti/K ratio is increased although it showed a tendency to increase in the KTWs with increasing Ti/K ratio. Meanwhile, the photocatalytic activity of the composites was superior to unreinforced resin mixtures. Mechanical properties namely, nanoindentation hardness and wear-rate of the bulk polymers enhanced significantly by KTW reinforcement.Conference Object Citation - Scopus: 3Production of Silver Loaded Photocatalytic Tio2 Powders by Ball Milling(TANGER Ltd., 2011) Aysin,B.; Park,J.; Ozturk,A.; Metallurgical and Materials Engineering; English Translation and InterpretationThe present study was undertaken to improve photocatalytic efficiency of TiO2 powder by silver doping and/or particle size reduction through mechanical ball milling. A planetary ball mill was employed to reduce the particle size of TiO2 powders to nanoscale and silver loading to TiO2 powders. Silver nitrate was used as silver source to obtain about 1% Ag load. Slurry taken from ball mill was separated by centrifugal separator into nano and micro sols. Separated nanosol was taken into the furnace to be dried at 103 °C and calcined at 400° C for 1 hour to assist silver loading. X-Ray powder diffraction (XRD) was employed to identify the crystalline phases present in the powders produced. XRD results revealed that doped TiO2 powders were consisted of only anatase phase of TiO2. Changes in lattice parameters of TiO2 structure after doping were determined also by XRD. Scanning Electron Microscope (SEM) and particle size analyzer were used for examining the size reduction effect of ball milling process. Photocatalytic performance of the powders was evaluated by Methylene Orange (MO) test under UV light illumination using UV-Spectrophotometer. © 2011 TANGER Ltd., Ostrava.
