A5103043253- Physics of Superconductivity and Magnetism
- Superconductivity in MgB2 and Alloys
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Structural Health Monitoring Techniques
- Magnetic and transport properties of perovskites and related materials
- Microstructure and Mechanical Properties of Steels
- Hydraulic and Pneumatic Systems
- Metallurgical Processes and Thermodynamics
- Infrastructure Maintenance and Monitoring
- Agriculture, Soil, Plant Science
- Railway Engineering and Dynamics
- Seismic Performance and Analysis
- Thermal Expansion and Ionic Conductivity
- Magnetic Properties of Alloys
- Magnesium Alloys: Properties and Applications
- Theoretical and Computational Physics
- Soil Carbon and Nitrogen Dynamics
- Microwave Engineering and Waveguides
- Boron and Carbon Nanomaterials Research
- Catalysis and Oxidation Reactions
- Catalytic Processes in Materials Science
- Heavy metals in environment
- Transport Systems and Technology
- Mine drainage and remediation techniques
Korea University
2019-2025
Myongji University
2016-2024
Ulsan National Institute of Science and Technology
2023
Georgia Institute of Technology
2023
Seoul National University of Science and Technology
2022
Hanyang University
2016-2022
Pohang Iron and Steel (South Korea)
2012-2020
Hitachi (Japan)
2001-2019
University of Seoul
2017
Pohang University of Science and Technology
2001-2016
Correct identification of the origins herbal medical products is becoming increasingly important in tandem with growing interest alternative medicine. However, visual inspection raw material still most widely used method, and newer scientific approaches are needed. To develop a more objective efficient tool for discriminating origins, particularly Korean Chinese, we employed nuclear magnetic resonance (NMR)-based metabolomics approach combined an orthogonal projections to latent...
We report the effect of sintering temperature on superconductivity MgB2 pellets prepared under a high pressure 3 GPa. The superconducting properties non-heated in this were poor. However, as increased, vastly enhanced, which was shown by narrow transition width for resistivity and low-field magnetizations. This shows that heat treatment is essential to improve properties. These changes found be closely related surface morphology observed using scanning electron microscopy.
The longitudinal resistivity (ρxx) and Hall coefficient (RH) were measured for MgB2 sintered under high pressure. We found that RH is positive like cuprate high-Tc superconductors, decreases as the temperature increases 40 K <T<300 K. cotangent of angle was to follow a+bT2 behavior from Tc 300 At T=100 K, RH=4.1×10−11 m3/C which hole carrier density determined be 1.5×1023/cm3. This 1–2 orders magnitude larger than those Nb3Sn optimally doped YBa2Cu3Oy superconductors.
This work shows that carbon dioxide, which is a main contributor to the global warming effect, could be utilized as selective oxidant in oxidative dehydrogenation of ethylbenzene over alumina-supported vanadium oxide catalysts. The modification catalytically active component with appropriate amounts antimony led more stable catalytic performance along higher styrene yield (76%) at high selectivity (>95%). improved behavior was attributable enhanced redox properties V-sites.
Quasiparticle tunneling spectra of the electron-doped (n-type) infinite-layer cuprate Sr_{0.9}La_{0.1}CuO_2 reveal characteristics that counter a number common phenomena in hole-doped (p-type) cuprates. The optimally doped with T_c = 43 K exhibits momentum-independent superconducting gap \Delta 13.0 +- 1.0 meV substantially exceeds BCS value, and spectral indicate insignificant quasiparticle damping by spin fluctuations absence pseudogap. response to quantum impurities Cu-sites also differs...
This paper describes the procedures for development of signal analysis algorithms using artificial neural networks Bridge Weigh-in-Motion (B-WIM) systems. Through procedure, extraction information concerning heavy traffic vehicles such as weight, speed, and number axles from time domain strain data B-WIM system was attempted. As one several possible pattern recognition techniques, an Artificial Neural Network (ANN) employed since it could effectively include dynamic effects bridge-vehicle...
A series of laboratory-scale experiments were carried out in order to elucidate the reaction mechanism between high Mn-high Al steel and CaO–SiO2-type molten mold flux at 1450°C, which represents taking place during continuous casting steel. Compared previous study [Kim et al., Metall. Mater. Trans. 44B (2013) 299–308], content liquid ([pct Al]0 = 5.2) MgO ((pct MgO)0 5 15) employed, confirm change rate-controlling step from mass transport more complicated steps including flux. It was found...
Abstract The material properties of steel and concrete vary depending on the loading rate to which they are subjected. To realistically evaluate seismic performance reinforced (RC) columns, it is necessary simulate that structures will experience during events as accurately possible. Real‐time dynamic testing preferred over quasi‐static for this purpose. On other hand, RC columns also depends axial force applied column. However, due large stiffness controlling test, particularly in real‐time...
Scanning tunneling spectroscopy of superconducting ${\mathrm{MgB}}_{2}$ ${(T}_{c}=39 \mathrm{K})$ were studied on high-density pellets and c-axis oriented films. The sample surfaces chemically etched to remove surface carbonates hydroxides, the data compared with calculated spectra for all symmetry-allowed pairing channels. potential $({\ensuremath{\Delta}}_{k})$ is best described by an anisotropic s-wave model,...
We have synthesized ZnCNi3 in which Zn replaces Mg of the superconducting intermetallic perovskite MgCNi3 ( K). Dc-resistivity and magnetic measurements show that is a paramagnetic metal without onset superconductivity down to 2 K. Furthermore, even though two compounds same lattice structure carrier density, their low temperature specific heats are substantially different. consider possible origins these observations strikingly different Tc can be understood within BCS theory.
A c-axis oriented thin film and a high-density sintered pellet of ${\mathrm{MgB}}_{2}$ have been studied by x-ray photoemission spectroscopy, compared to measurements from MgO ${\mathrm{MgF}}_{2}$ single crystals. The as-grown surface has layer which is Mg-rich oxidized, effectively removed nonaqueous etchant. subsurface region the Mg deficient. This nonideal near-surface may explain varied scanning tunneling spectroscopy results. core level Auger signals are similar metallic...
Simple, short, and compact hashtags cover a wide range of information on social networks. Although many works in the field natural language processing (NLP) have demonstrated importance hashtag recommendation, recommendation for images has barely been studied. In this paper, we introduce HARRISON dataset, benchmark real world The dataset is realistic composed 57,383 photos from Instagram an average 4.5 associated each photo. To evaluate our design baseline framework consisting visual feature...
We report the magnetic-field dependence of irreversible magnetization recently discovered binary superconductor ${\mathrm{MgB}}_{2}.$ For temperature region $T<{0.9T}_{c},$ contribution bulk pinning to overwhelms that surface pinning. This was evident from fact curves $M(H)$ were well described by critical-state model without considering reversible and surface-pinning effect. It also found at various temperatures scaled when field normalized characteristic scaling factors ${H}^{*}(T)$...
We present reversible magnetization measurements on MgB2 single crystals in magnetic fields up to 2.5 T applied parallel the crystal's c-axis. This is analyzed terms of Hao-Clem model, and various superconducting parameters, such as critical [Hc(0) Hc2(0)], characteristic lengths [xi(0) lambda(0)], Ginzburg-Landau parameter, kappa, are derived. The temperature dependence penetration depth, lambda(T), obtained from analysis could not be explained by theories assuming a gap. Our data well...