Park, Jongee
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Jongee Park
P.,Jongee
P., Jongee
J.,Park
Park J.
Park, Jongee
Park,J.
J., Park
Park,Jongee
Jongee, Park
Park, J
P.,Jongee
P., Jongee
J.,Park
Park J.
Park, Jongee
Park,J.
J., Park
Park,Jongee
Jongee, Park
Park, J
Job Title
Profesör Doktor
Email Address
jongee.park@atilim.edu.tr
Main Affiliation
Metallurgical and Materials Engineering
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Sustainable Development Goals
14
LIFE BELOW WATER
0
Research Products
2
ZERO HUNGER
0
Research Products
11
SUSTAINABLE CITIES AND COMMUNITIES
1
Research Products
1
NO POVERTY
0
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12
RESPONSIBLE CONSUMPTION AND PRODUCTION
0
Research Products
7
AFFORDABLE AND CLEAN ENERGY
12
Research Products
5
GENDER EQUALITY
0
Research Products
3
GOOD HEALTH AND WELL-BEING
2
Research Products
9
INDUSTRY, INNOVATION AND INFRASTRUCTURE
0
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13
CLIMATE ACTION
0
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6
CLEAN WATER AND SANITATION
0
Research Products
10
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0
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4
QUALITY EDUCATION
0
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15
LIFE ON LAND
0
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16
PEACE, JUSTICE AND STRONG INSTITUTIONS
0
Research Products
17
PARTNERSHIPS FOR THE GOALS
0
Research Products
8
DECENT WORK AND ECONOMIC GROWTH
0
Research Products
Documents
53
Citations
927
h-index
19
Documents
50
Citations
890
Scholarly Output
57
Articles
45
Views / Downloads
21/0
Supervised MSc Theses
3
Supervised PhD Theses
0
WoS Citation Count
819
Scopus Citation Count
855
WoS h-index
19
Scopus h-index
19
Patents
0
Projects
1
WoS Citations per Publication
14.37
Scopus Citations per Publication
15.00
Open Access Source
7
Supervised Theses
3
Google Analytics Visitor Traffic
| Journal | Count |
|---|---|
| Ceramics International | 10 |
| Journal of Nanoscience and Nanotechnology | 3 |
| Applied Surface Science | 2 |
| 3rd International Conference on NANOCON -- SEP 21-23, 2011 -- Brno, CZECH REPUBLIC | 2 |
| Advanced Materials Research -- 2012 International Conference on Advances in Materials Science and Engineering, AMSE 2012 -- 9 December 2012 through 10 December 2012 -- Seoul -- 95488 | 2 |
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Article Citation - WoS: 44Citation - Scopus: 54Preparation and Photocatalytic Activity of G-c3n4< Heterojunctions Under Solar Light Illumination(Elsevier Sci Ltd, 2020) Gundogmus, Pelin; Park, Jongee; Ozturk, AbdullahThe solar light sensitive g-C3N4/TiO2 heterojunction photocatalysts containing 20, 50, 80, and 90 wt% graphitic carbon nitride (g-C3N4) were prepared by growing Titania (TiO2) nanoparticles on the surfaces of g-C3N4 particles via one step hydrothermal process. The hydrothermal reactions were allowed to take place at 110 degrees C at autogenous pressure for 1 h. Raman spectroscopy analyses confirmed that an interface developed between the surfaces of TiO2 and g-C3N4 nanoparticles. The photocatalyst containing 80 wt% g-C3N4 was subsequently heat treated 1 h at temperatures between 350 and 500 degrees C to improve the photocatalytic efficiency. Structural and optical properties of the prepared g-C3N4/TiO2 heterojunction nanocomposites were compared with those of the pristine TiO2 and pristine g-C(3)N(4 )powders. Photocatalytic activity of all the nanocomposites and the pristine TiO2 andg-C3N4 powders were assessed by the Methylene Blue (MB) degradation test under solar light illumination. g-C3N4/TiO2 heterojunction photocatalysts exhibited better photocatalytic activity for the degradation of MB than both pristine TiO2 and g-C3N4. The photocatalytic efficiency of the g-C3N4/TiO2 heterojunction photocatalyst heat treated at 400 degrees C for 1 his 1.45 times better than that of the pristine TiO2 powder, 2.20 times better than that of the pristine g-C3N4 powder, and 1.24 times better than that of the commercially available TiO2 powder (Degussa P25). The improvement in photocatalytic efficiency was related to i) the generation of reactive oxidation species induced by photogenerated electrons, ii) the reduced recombination rate for electron-hole pairs, and iii) large specific surface area.Conference Object Citation - WoS: 3Synthesis of Tio2 Nanostructures Via Hydrothermal Method(John Wiley & Sons inc, 2015) Bilgin, Nursev; Agartan, Lutfi; Park, Jongee; Ozturk, AbdullahTitania (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 degrees 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.Article Citation - WoS: 8Effect of H2o Ratio on Photocatalytic Activity of Sol-Gel Tio2 Powder(Ice Publishing, 2013) Agartan, Lutfi; Kapusuz, Derya; Park, Jongee; Ozturk, AbdullahEffect of water/tetraethyl orthotitanate molar ratio (R) on the formation and morphology of sol-gel-derived titania powder has been studied. Solutions for R of 3 and 5 have been prepared. Initial viscosity of the solutions and viscosity of the gels prepared by aging the solutions for some time were measured. Results revealed that lower gel viscosities lead to better crystallization of the aerogel. Aerogels were dried at 80 degrees C for 24 h and then calcined at 300 degrees C for 1 h to obtain titania powders. The structural and morphological analyses of the powders were performed using X-ray diffraction and scanning electron microscopic characterization techniques. Titania particles obtained after calcination composed of only anatase phase and were in the size range of 9-50 nm. The photocatalytic activity of the powders was evaluated in terms of the degradation of methylene blue (MB) solution under UV (ultraviolet) illumination. A diffuse reflectance spectroscopy was used for the band gap energy measurements. Results revealed that R had a profound effect on the particle morphology and photocatalytic activity of sol-gel-derived titania powders. The titania powders prepared from the solution for R of 5 degraded 99.47% of MB solution under UV illumination in 90 min.Article A Benchmark of Expert-Level Academic Questions to Assess AI Capabilities(Nature Portfolio, 2026) Phan, Long; Gatti, Alice; Li, Nathaniel; Khoja, Adam; Kim, Ryan; Ren, Richard; Scaramuzza, Davide; Park, JongeeBenchmarks are important tools for tracking the rapid advancements in large language model (LLM) capabilities. However, benchmarks are not keeping pace in difficulty: LLMs now achieve more than 90% accuracy on popular benchmarks such as Measuring Massive Multitask Language Understanding(1), limiting informed measurement of state-of-the-art LLM capabilities. Here, in response, we introduce Humanity's Last Exam (HLE), a multi-modal benchmark at the frontier of human knowledge, designed to be an expert-level closed-ended academic benchmark with broad subject coverage. HLE consists of 2,500 questions across dozens of subjects, including mathematics, humanities and the natural sciences. HLE is developed globally by subject-matter experts and consists of multiple-choice and short-answer questions suitable for automated grading. Each question has a known solution that is unambiguous and easily verifiable but cannot be quickly answered by internet retrieval. State-of-the-art LLMs demonstrate low accuracy and calibration on HLE, highlighting a marked gap between current LLM capabilities and the expert human frontier on closed-ended academic questions. To inform research and policymaking upon a clear understanding of model capabilities, we publicly release HLE at https://lastexam.ai.Article Citation - WoS: 44Citation - Scopus: 43Sol-Gel Synthesis and Photocatalytic Activity of B and Zr Co-Doped Tio2(Pergamon-elsevier Science Ltd, 2013) Kapusuz, Derya; Park, Jongee; Ozturk, AbdullahEffects of boron (B) and/or zirconium (Zr) doping on photocatalytic activity of sol-gel derived titania (TiO2) powders were investigated. A conventional, non-hydrous sol-gel technique was applied to synthesize the B, Zr doped/co-doped TiO2 powders. Doping was made at molar ratios of Ti/B=1 and Ti/Zr=10. Sol-gel derived xero-gels were calcined at 500 degrees C for 3 h. The crystal chemistry and the morphology of the undoped and B, Zr doped/co-doped TiO2 nanoparticles were investigated using X-ray diffractometer and scanning electron microscope. Nano-scale (9-46 nm) TiO2 crystallites were obtained after calcination. Doping and co-doping decreased the crystallite size. Photocatalytic activity was measured through the degradation of methylene blue (MB) under 1 h UV-irradiation using a UV-vis spectrophotometer. Results revealed that B doping into anatase caused the formation of oxygen vacancies, whereas Zr addition caused Ti substitution. Both B and Zr ions had a profound effect on the particle morphology and photocatalytic activity of TiO2. The photocatalytic activity of B and Zr doped TiO2 particles increased from 27% to 77% and 57%, respectively. The best activity (88.5%) was achieved by co-doping. (C) 2013 Elsevier Ltd. All rights reserved.Conference Object Citation - WoS: 1PRODUCTION OF SILVER LOADED PHOTOCATALYTIC TIO2 POWDERS BY BALL MILLING(Tanger Ltd, 2011) Aysin, Basak; Park, Jongee; Ozturk, AbdullahThe 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 degrees C and calcined at 400 degrees 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.Article Effects of Graphene Transfer and Thermal Annealing on Anticorrosive Properties of Stainless Steel(Amer Scientific Publishers, 2017) Oh, Jeong Hyeon; Han, Sangmok; Kim, Tae-Yoon; Park, Jongee; Ozturk, Abdullah; Kim, Soo YoungStainless steel (STS) films were annealed in a thermal quartz tube and covered with graphene to improve their anticorrosive properties. Graphene was synthesized via the chemical vapor deposition method and transferred onto the surface of the STS film by the layer-by-layer approach. The structure of the STS film changed from alpha-Fe to gamma-Fe after annealing at 700 C for 1 h, resulting in an increase of 82.72% in the inhibition efficiency. However, one-layer graphene acted as a conductive pathway and therefore deteriorated the anticorrosive properties of the STS film. To overcome this problem, graphene was transferred layer by layer onto the STS film. It was found that transfer of three layers of graphene onto the STS film resulted in a 91.57% increase in the inhibition efficiency. Therefore, thermal annealing and transfer of multilayer graphene are considered to be effective in enhancing the anticorrosive properties of STS films.Article Citation - WoS: 12Citation - Scopus: 11Enhanced Bioactivity and Low Temperature Degradation Resistance of Yttria Stabilized Zirconia/Clay Composites for Dental Applications(Elsevier Sci Ltd, 2022) Tufan, Yigithan; Park, Jongee; Ozturk, Abdullah; Ercan, BaturYttria stabilized zirconia (YSZ)/clay composites were produced to improve osseointegration and undesired tetragonal-to-monoclinic phase transformation (low temperature degradation, LTD) of YSZ ceramics so that long-term clinical success of YSZ implants is achieved. Various amounts (0.5,1,2, and 4 wt%) of clay was incorporated to YSZ. Predetermined amounts of clay and YSZ were mixed and pressed uniaxially at 15 MPa into compacts that were subsequently pressureless sintered at 1450 degrees C. Density, compressive strength, hardness and indentation crack resistance of 4 wt% clay incorporated YSZ/clay composite were 5.77 +/- 0.01 g/cm3, 1188 +/- 121 MPa, 1223 +/- 9 HV, and 4.4 +/- 0.1 MPa root m, respectively. Additionally, biological properties of YSZ/clay composites were assessed in vitro using bone cells. Incorporation of 4 wt% clay significantly enhanced bone cell prolifer-ation, spreading, and functions. Moreover, a significant increase in the LTD resistance of YSZ was achieved upon 4 wt% clay incorporation. The findings collectively suggest that YSZ/clay composites have a potential to be used as an alternative material for dental applications.Article Citation - WoS: 11Citation - Scopus: 10Synthesis and Characterization of Hydrothermally Grown Potassium Titanate Nanowires(Korean Assoc Crystal Growth, inc, 2015) Kapusuz, Derya; Kalay, Y. Eren; Park, Jongee; Ozturk, Abdullah; Metallurgical and Materials EngineeringPotassium titanate (KT) nanowires were synthesized by a one-step hydrothermal reaction between TiO2 and aqueous KOH solution. The effects of KOH concentration and reaction time on hydrothermal formation and KT nanowire growth were investigated. The nanowire growth mechanism was elucidated using a combined study of powder X-ray diffraction, and scanning and transmission electron microscopy. The results revealed that hydrothermal growth was initiated by the formation of amorphous-like Ti-O-K sheets in anatase. Increasing hydrothermal reaction time caused the transformation of anatase to Ti-O-K sheets, from which potassium hexa-titanate (K2Ti6O13) nuclei formed and grew to establish one-dimensional morphology through preferential growth along the b-axis. It was revealed that the hydrothermal reactions followed a quite different mechanism than the well-known calcination route. Potassium tetra-titanate (K2Ti4O9) crystals formed in the amorphous region using the hexa-titanate phase as a nucleation site for heterogeneous crystallization. Increasing the KOH concentration in the solution accelerated the hydrothermal reaction rate.Article Citation - WoS: 10Alkaline Hydrothermal Synthesis, Characterization, and Photocatalytic Activity of Tio2 Nanostructures: the Effect of Initial Tio2 Phase(Amer Scientific Publishers, 2019) Erdogan, Nursev; Park, Jongee; Choi, Woohyuk; Kim, Soo Young; Ozturk, AbdullahOne-dimensional (1D) titanate nanostructures were synthesized by hydrothermal route, using commercially available TiO2 (P25) and anatase powders as precursor materials and strong NaOH solution as catalyzer. The prepared titanates were calcined, followed by protonation to produce TiO2 nanostructures having enhanced photocatalytic and photovoltaic properties. The synthesized TiO2 1D nanostructures were characterized using field-emission scanning electron microscope, high-resolution electron microscope, X-ray diffraction analysis, and UV-Vis photospectroscopy to understand the effect of initial TiO2 phase on morphological and crystallographic features, and bandgap. Methylene blue degradation test was applied to evaluate the photoactivity of the products obtained after different stages of the process. The findings indicate that 1D TiO2 nanostructures form by different mechanisms from dissolved aggregates during hydrothermal process, depending on the crystal structure of the initial precursor used. Photocatalytic test results reveal that protonated titanates have considerable adsorption capability, while photocatalytic degradation depends on TiO2 transformation.
