TiO₂ is a versatile metal oxide material that is frequently used as a photo-catalyst for organic pollutant oxidation and a functional material for ultraviolet-ray protection. To improve its chemical/physical properties and widen the range of industrial application, it is demanded to control the crystalline feature and morphology precisely by applying advanced nano-synthesis methods. In this study, we prepared TiO₂ nanoparticles using the water-in-oil (W/O) microemulsion method and compared them with the particles synthesized by the conventional precipitation method. Also, we tried to find the optimum conditions for obtaining nano-sized, anatase-rich TiO₂ particles by the W/O microemulsion method. We analyzed the crystalline feature and particle size of the prepared samples using X-ray diffraction (XRD) and Transmission electron microscopy (TEM). In summary, we found the W/O microemulsion is more effective than precipitation in obtaining nano-sized TiO₂. The best result was derived when the microemulsion was formed using AOT surfactant, hydrolysis was performed under basic condition and the sample was calcined at 200℃.

Nowadays, traffic congestion is emerging as a major problem due to the rapid population growth and the increase in automobiles. The train is a convenient means of transportation that can efficiently solve these problems. Trains have been developed in line with human aspirations for a long time, but research on safety is still insufficient. This study aims to check safety by conducting static tests and fatigue tests on bogie frames, and to help develop bogie frames in the future. For the static test, a strain gauge was attached to the point where the local stress concentration was expected beforehand, and the result value was derived, compared with existing theories, and expressed as a Goodman diagram. In the fatigue test, a total of 10 million loads were applied over three stages, and no cracks appeared in the non-destructive test conducted after each stage. Both tests were conducted according to the strict test method of the bogie frame presented by the UIC Code. It satisfied both fatigue life and strength evaluation criteria and was judged to be a bogie frame usable for safe train production.

Lithium-ion batteries are predominantly employed in electric vehicles and energy storage devices, offering the advantage of high energy density. However, they are susceptible to efficiency degradation when operated at high temperatures due to their sensitivity to the external environment. In this study, we conducted experiments using an indirect cooling method to prevent thermal runaway and explosions in lithium-ion batteries. The results were validated by comparing them with heat transfer simulations conducted through a commercial finite element analysis program. The experiments included single-cell exothermic tests and cooling experiments on a battery pack with 10 cells connected in series, utilizing 21700 lithium-ion batteries. To block external temperature influences, the experimental environment featured an extrusion method insulation in the environmental chamber. The cooling system, suitable for indirect cooling, was constructed with copper tubes and pins. The heat transfer analysis began by presenting a single-cell heating model using commercial software, which was then employed to analyze the heating and cooling of the battery pack.

Stretchable and flexible electronics that comply with dynamic movements and micromotion of the human tissues can enable real-time monitoring of physiologic signals onto the human skin and in the brain, respectively. Especially, gallium based liquid metal stretchable electronics can offer human-interactive biosensors to monitor various physiologic parameters. However, the liquid-like nature, surface oxidation and contamination by organic materials, and low biostability of the liquid metals have still limited the long-term use as bioelectronics. Here we introduced electrochemical deposition without oxidation pathways to overcome these practical challenges in liquid metal bioelectronics. CNT/PDDA composite with reduction way and PEDOT:BF₄ with oxidation way under organic solvent are suggested as rationally designed material engineering approaches. We confirmed that the structures with the soft, flexible, and stretchable liquid metal platform can successfully detect dopamine with a high sensitivity and selectivity, record neural signals including action potentials without scar formation, and monitor physiologic signals such as EMG and ECG.

This paper provides a general overview of surface catalytic recombination in hypersonic flow. The surface catalytic recombination phenomena is elaborated in terms of its general overview and numerical modeling associated with it. The general overview of the surface catalytic recombination phenomena describes the elementary surface reactions for the surface catalytic and the role of the surface catalytic recombination efficiency in the heat transfer determination. In the numerical modeling, the surface catalytic recombination is described based on the stagnation-point boundary layer analysis, and finite-rate surface reaction modeling. Throughout this overview manuscript, a general understanding of this phenomena is obtained and can be used as foundation for deeper application with the numerical computational fluid dynamics (CFD) flow solver to estimate the surface heat transfer in the hypersonic vehicles.

Spinel LiNi_0.5Mn_1.5O₄ (LNMO) has been considered as one of most promising cathode material, because of its low-cost and competitive energy density. However, 4.7V vs. Li/Li⁺ of high operating potential facilitates electrolyte degradation on cathode-electrolyte interface during charge-discharge process. In particular, commercial polyvinylidene fluoride (PVDF) is not sutaible for LNMO cathode binder because its weak van der waals force induces thick and non-uniform coverage on the cathode surface. In this review, we study high performance binders for LNMO cathode, which forms uniform coating layer to prevent direct contact between electrolyte and LNMO particle as well as modifying high quality cathode electrolyte interphase, improved cell performace.

Cluster tools are extensively employed in various wafer fabrication processes within the semiconductor manufacturing industry, including photo lithography, etching, and chemical vapor deposition. Contemporary fabrication facilities encounter customer orders with technical specifications that are similar yet slightly varied. Consequently, modern fabrications concurrently manufacture two or three different wafer types using a cluster tool to maximize chamber utilization and streamline the flow of wafer lots between different process stages. In this review, we introduce two methods of concurrent processing of multiple wafer types: 1) concurrent processing of multiple wafer types with different job flows, 2) concurrent processing of multiple wafer types with identical job flows. We describe relevant research trends and achievements and discuss future research directions.

In this review, we introduce the non-parametric Bayesian filtering algorithm known as the point-mass filter (PMF) and discuss recent studies related to it. PMF realizes Bayesian filtering by placing a deterministic grid on the state space and calculating the probability density at each grid point. PMF is known for its robustness and high accuracy compared to other nonparametric Bayesian filtering algorithms due to its uniform sampling. However, a drawback of PMF is its inherently high computational complexity in the prediction phase. In this review, we aim to understand the principles of the PMF algorithm and the reasons for the high computational complexity, and summarize recent research efforts to overcome this challenge. We hope that this review contributes to encouraging the consideration of PMF applications for various systems.