A5044580642- High-Velocity Impact and Material Behavior
- Advanced ceramic materials synthesis
- Advanced Photocatalysis Techniques
- Microwave Dielectric Ceramics Synthesis
- TiO2 Photocatalysis and Solar Cells
- Ferroelectric and Piezoelectric Materials
- Energetic Materials and Combustion
- Electromagnetic Launch and Propulsion Technology
- Semiconductor Quantum Structures and Devices
- Luminescence Properties of Advanced Materials
- GaN-based semiconductor devices and materials
- Metal and Thin Film Mechanics
- Laser-Plasma Interactions and Diagnostics
- Advanced materials and composites
- Structural Response to Dynamic Loads
- Aluminum Alloys Composites Properties
- Glass properties and applications
- Semiconductor materials and devices
- Diamond and Carbon-based Materials Research
- Numerical methods in engineering
- ZnO doping and properties
- Semiconductor materials and interfaces
- Fatigue and fracture mechanics
- Quantum Dots Synthesis And Properties
- Powder Metallurgy Techniques and Materials
Gangneung–Wonju National University
2016-2025
Wonkwang University
2022-2025
Chonnam National University
2024
Kyung Hee University
1992-2023
Chonnam National University Hwasun Hospital
2023
Korea University
2019-2023
New York City Fire Department
2021
Frontier Energy (United States)
2020
Kyungpook National University
2019
Korea Institute of Science and Technology
2019
The performance of dye-sensitized solar cells (DSSCs) consisting anatase TiO2 nanoparticles that were synthesized via a two-step sol−gel process was investigated using electron transport and optical characterizations. Spherical with the average diameter 20 nm, elongated nanorods an aspect ratio (AR) 5, nanowires AR = 10 synthesized. possess narrow size distribution, high crystallinity, negligible surface defects residual organics, which is very suitable for achieving highly efficient...
In this study, an aluminum-doped zinc oxide (AZO) layer was used as a transparent conducting (TCO) in ZnO nanowire (NW)-based dye-sensitized solar cells (DSSCs). The well aligned, single crystalline NW arrays that were grown on the AZO films exhibited better DSSC performance (an increased photocurrent density and fill factor) than those fluorine doped tin (FTO) films. I−V characteristics electrochemical impedance spectroscopy measurements for FTO clearly showed superior caused by facilitated...
Chronic low back pain (CLBP) has a significant effect on quality of life and imposes great economical burden society. In number studies, validated questionnaires had been given to CLBP patients determine their health-associated life, sleep disturbance, psychological status. However, such outcome studies not performed previously in Korea.We used self-report compare with an age- sex-matched healthy control group. Between September 2012 August 2013, we enrolled 47 who for more than 3 months...
Individuals requiring insulin therapy for type 2 diabetes often require escalation of their regimen to achieve glycaemic control. Optimal management strategies uncontrolled would improve control without hypoglycaemia and weight gain. This study compared the efficacy tolerability adding sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, up 20% increase in dose patients with on therapy.We conducted a 24-week, randomized, active-competitor, parallel-group subjects [haemoglobin A1c (HbA1c) =...
Introduction: Cartilage regeneration is a challenging issue due to poor regenerative properties of tissues. Electrospun nanofibers hold enormous potentials for treatments cartilage defects. However, nanofibrous materials used the treatment defects often require physical and/or chemical modifications promote adhesion, proliferation, and differentiation cells. Thus, it highly desirable improve their surface with functionality. We aim design hydrophilic, adhesive, compound K-loaded Methods:...
Plasmodium vivax malaria reemerged in the Republic of Korea 1993 near Demilitarized Zone (DMZ). We reviewed clinical features 101 symptomatic patients with malaria. Of patients, 77 (76.3%) were veterans who had served DMZ; their median age was 23 years. The duration minimum latent period > 6 months 66.2% (51 77) (median, 278 days). Tertian fever developed 69 (68.3%). Severe thrombocytopenia platelet counts < 60,000/microL common (29.6% patients). parasite densities ranged 32-52,127...
A simple phenomenological constitutive model has been proposed to describe dynamic deformation behavior of various metals in wide strain rate, strain, and temperature regimes. The formulation the is, σ=[A+B{1−exp(−Cε)}][D ln(ε̇/ε̇0)+exp(E⋅ε̇/ε̇0)][1−(T−Tref)/(Tm−Tref)]m, where σ is flow stress, ε ε̇ ε̇0 reference T temperature, Tref Tm melting A, B, C, D, E, m are material parameters. successfully describes not only linear rise stress with logarithmic rate for many metals, but also upturn at...
A specimen designed to convert compressive stress into tensile during the split Hopkinson pressure bar (SHPB) test is employed for inverse calibration of a constitutive model steel with flow exceeding approximately 1,600 MPa. This accomplished by tracking signals through repeated simulations. The maximum strain rate, strain, and temperature were 6,500 s−1, 0.53, 550 K, respectively. These values significantly surpassed those obtained from standard SHPB test, as predicted an Excel template...
Economic and reliable online health monitoring strategies are very essential for safe operation of civil, mechanical aerospace structures. This study presents structural (SHM) techniques using wireless impedance sensor nodes equipped with both functions damage identification self-diagnosis. The node incorporating a miniaturized measuring chip, microcontroller radio-frequency (RF) telemetry is the capabilities temperature sensing, multiplexing several sensors, local data analysis. feasibility...
The commonly employed mathematical functions in constitutive models, such as the strain hardening/softening model, strain-rate hardening factor, and temperature-softening are reviewed, their prediction characteristics illustrated. results may assist one (i) to better understand behavior of model that employs a given function; (ii) find reason for deficiencies, if any, an existing model; (iii) avoid employing inappropriate function future models. This study subsequently illustrates flow...
Background Inflammation is believed to predict coronary heart disease (CHD) in healthy subjects and patients with atherosclerosis. We investigated the association of high sensitivity C-reactive protein (HS-CRP) other inflammatory markers on cardiovascular outcome, carotid atherosclerosis hypertensive patients. Methods Results conducted a cross-sectional study 122 compared them 64 normotensive volunteers. measured circulating levels HS-CRP, white blood cells (WBC), albumin, fibrinogen,...
A nanoporous CaCO3 overlayer-coated TiO2 thick film was prepared by the topotactic thermal decomposition of Ca(OH)2, and its performance as an electrode a dye-sensitized solar cell investigated. As compared to bare TiO2, CaCO3-coated provided higher specific surface area and, subsequently, larger amount dye adsorption; this in turn increased short-circuit current (Jsc). Furthermore, coating demonstrated impedance at TiO2/dye/electrolyte interface lifetime photoelectrons, indicating improved...
The surface of TiO2 photoelectrode was treated by dipping in nitric acid and subsequently coating with solar light absorbing dye. influence surface-modified photoelectrodes on the performance dye-sensitized cells (DSCs) investigated. treatment increased DSC energy conversion efficiency from 5.4 to 6.2%, which is mainly attributed increase photocurrent rather than change open circuit voltage. comparative studies were done using hydrochloric photoelectrode. This demonstrates that retards back...
Additional hydrogen (H2) annealing and subsequent electrochemical treatment are found to make tin-doped indium oxide (ITO)-based photoelectrodes suitable for highly efficient dye sensitized solar cells. The additional H2 process recovered the electrical conductivity of ITO film same as its initial high conductivity, which enhanced charge collecting property. Moreover, employment oxidation TiO2/ITO photoelectrode improved energy conversion efficiency ITO-based dye-sensitized cells (DSSC),...
Thermodynamic stability of anatase nanoparticles and their transformation behaviors to rutile phase in an acidic solution was investigated situ at two different peptization temperatures using a freeze-drying method. When peptized 30 °C, the initial product with significantly distorted atomic structure, significant amount hydroxyl group Ti3+ ions, and, thus, thermodynamically unstable state. The instability °C-peptized responsible for suitable later via dissolution form titanium hydroxylate,...