Jung Won Lee

The spin engineering of CoxPd1−x alloy films on Pb(Zr0.52Ti0.48)O3 substrates was studied by measuring the polar Kerr rotation hysteresis loops and their electric field dependencies. The electric field dependence of polar Kerr rotation strongly depends on the composition of the CoPd alloys. This is especially so in the case of Co0.25Pd0.75 alloy film where the hysteresis loop of magnetic remanence with respect to voltage applied is nearly squared, i.e., the direction of magnetization maintains i

Biofilm formation is one of the leading causes of complications after surgery in clinical settings. In this study, we profiled the biofilm-forming ability of various periprosthetic infection-associated pathogens on medically relevant surfaces, polystyrene (PS) and titanium (Ti). We also explored how a specific environmental stressor, epigallocatechin gallate (EGCG), affected biofilm formation. First, Congo red tests revealed that all microorganisms formed biofilms within 72 h. Then, the amounts

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study,

The increasing frequency of water scarcity is an acute worldwide problem. Nature-inspired water harvesting from fog is an important method to obtain freshwater in arid areas. Existing literature reports varied and diversified results in water harvesting capacity by employing a biphilic surface with control over hydrophilic and hydrophobic patterns. In this study, we first demonstrate a facile and scalable method to fabricate a biphilic surface using a simple electroless etching and desilanizatio

Enhancement in heat-transfer performance via dropwise condensation on superhydrophobic surfaces is much greater than that realized via generic condensation on a regular surface. However, if the supersaturation level during condensation increases above a specific value, water may seep to greater depths between structures. This may lead to attached condensation, which reduces condensation heat-transfer efficiency below that of ordinary surfaces. Therefore, it is critical to avoid the occurrence of

In the present study, we have numerically investigated the effects of the fuel-side nitrogen dilution on the precise structure and NO x formation characteristics of the turbulent syngas non-premixed flames. The turbulence-chemistry interaction is represented by the Lagrangian flamelet model. In context with the Lagrangian flamelet model, the NO concentration is obtained directly from the flamelet calculation based on the full NO x chemistry, and the radiative heat loss is taken into account thro

The main goal of this research effort is to determine the optimal trajectory for an unmanned aerial vehicle (UAV) in a dynamic environment. A Model Predictive Control (MPC) approach is utilized to provide collision avoidance in view of pop-up threats and a random set of moving and stationary obstacles (no fly zones). The UAV path planning needs to adapt in near real-time to the dynamic nature of the operational scenario, and to react rapidly to updates in the situational awareness, given the veh