This paper proposes a circular sequential lighting control method to reduce current imbalance and luminance deviation among multiple LED modules in AC-powered LED lighting systems. Conventional fixed-sequence lighting control repeatedly prioritizes the same LED modules in every rectified voltage cycle, which leads to unequal current distribution, luminance non-uniformity, and the accelerated degradation of specific modules during long-term operation. To address these limitations, a circular sequential lighting strategy is introduced, in which the lighting order is cyclically rotated at every rectified cycle, ensuring that all LED modules experience equal lighting opportunities. A prototype AC-LED lighting system consisting of four series-connected LED modules was implemented and experimentally evaluated. The results demonstrate that, while the conventional fixed-sequence method produces a maximum average current deviation of up to 1.6 mA among modules, the proposed method equalizes the average current across all modules to approximately 17.1 mA. Furthermore, the flicker index remains at 0.13, which is comparable to that of the conventional method, indicating that luminance uniformity is improved without degradation of optical performance. The proposed circular sequential lighting control effectively distributes electrical stress, enhances luminance uniformity, and improves long-term reliability, making it a practical and efficient solution for high-quality AC-LED lighting applications.

This review systematically examines the structural characteristics, compositional design strategies, and recent research trends of layered double hydroxides (LDHs), which are recognized as promising electrocatalyst materials in electrochemical nitrate-to-ammonia conversion. Despite the rapid growth in related research, achieving simultaneous high selectivity and efficiency remains a significant technical challenge due to the complex mechanisms of the nitrate reduction reaction (NitRR) and its inherent competition with the hydrogen evolution reaction (HER). In this study, we analyzed the structural contributions of LDH catalysts for maximizing nitrate reduction efficiency and systematically established key catalyst design indicators required to ensure optimal performance. Specifically, we provide a detailed investigation of the physicochemical mechanisms for enhancing NH₃ production by precisely regulating the adsorption energies of reaction intermediates and maximizing charge transfer efficiency through compositional control and defect engineering. Furthermore, we discuss advanced structural design strategies, such as core-shell tandem structures, MOF-derived architectures, and interlayer anion control, as effective methods for enhancing catalytic performance and optimizing mass transport processes. These insights offer a strategic roadmap for designing high-performance LDH catalysts and represent a critical step toward the practical implementation of sustainable green ammonia production systems, particularly for integration into high-efficiency membrane electrode assembly (MEA) technologies.

The growing demand for miniaturized, lightweight, and sustainable electronic devices has intensified the need for advanced bonding materials. Existing electrically conductive adhesives (ECAs) often rely on high silver (Ag) content, resulting in elevated costs and environmental concerns. This study successfully developed a novel ECA with significantly reduced Ag content without compromising essential electrical conductivity and adhesion performance. Experimental results revealed that the optimized ECA demonstrates electrical conductivity comparable to that of commercial products, with notable advantages in cost reduction and eco-friendliness. These advancements position the developed ECA as a promising solution for next-generation electronic manufacturing, contributing to low-carbon technologies and sustainable practices. Future applications could further broaden its use across diverse electronic systems, driving progress in environmentally conscious technologies.

This paper is a study on frequency analysis and electronic noise reduction of energy storage system (ESS). We acquired 4 necessary data for about 2 minutes and 4 seconds using a sampling frequency of 10,000 Hz in ESS. Fast Fourier transform (FFT) was used for electronic noise analysis from the acquired data. As a result, it was confirmed that DC component, fundamental wave, second and higher harmonic component exist. For the attenuation of harmonics, low-pass filter (LPF) was applied. We confirmed that an attenuation of approximately 59.3% appears from the second harmonic. The presence of many harmonic components in the data of the ESS was expected to occur due to the insufficiency of optimization among the modules inside the ESS. Therefore, we propose that a national certification system for ESS should be introduced to settle down the issue properly.

In this study, we created a DBD plasma device and a MnO₂ catalyst mesh filter for evaluating ozone reduction of devices via the catalyst method. The DBD plasma device was manufactured by applying MnO₂ paste to soda lime glass via the screen-printing method. The MnO₂ catalyst mesh filter was manufactured by mixing MnO₂ powder with binder with a 10% difference in concentration from 10% to 50% and then applying it using the dip-coating method. Finally, we sintered a MnO₂ catalyst mesh filter in an electric furnace. We evaluated the characteristics of ozone generation according to the MnO₂ gas flow of DBD plasma devices, the opening ratio, and ozone reduction performance of the MnO₂ catalyst filters. Ozone reduction performance was approximately 20.4% at MnO₂10 wt%, 37.8% at MnO₂ 30 wt% and 50% at MnO₂ 50 wt%.

An increase in the temperature of photovoltaic (PV) modules causes reduced power output and shorter lifetime. Because of these characteristics, demands for the heat dissipation of PV modules are increasing. In this study, we attached a heat dissipation sheet to the back sheet of a shingled PV module and observed the temperature changes. The PV shingled module was tested under Standard Test Conditions (STCs; irradiance: 1,000 W/m², temperature: 25℃, air mass: 1.5) using a solar radiation tester, wherein the temperature of the PV module was measured by irradiating light for a certain duration. As a result, the temperature of the PV module with the heat dissipation sheet decreased by 3℃ compared to that without a heat dissipation sheet. This indicated that the power loss was caused by a temperature increase of the PV module. In addition, it was confirmed that the primary parameter contributing to the reduced PV module output power was the open circuit voltage (Voc).

Radiation noise due to EMI noise generated by the driving circuits of LED lighting devices in a medical imaging room was reduced by decreasing the noise source in the driving circuits and changing the number of corrections in EMI filters. Noise attenuation and filter changes enabled driving circuits that reduced the electromagnetic waves. Such circuits were efficiently designed by using capacitors and inverters in a given space. Therefore, the malfunction of radiation devices can be minimized by using EMI-reduction filter circuits, and reliable operation of medical devices can be expected by blocking electromagnetic waves.

The facile synthesis of shape-controlled Pd nanoparticles (PdNPs) with ascorbic acid as a reducing agent and cetyltrimethylammonium bromide (CTAB) as a capping agent is presented in this study. The synthesized PdNPs were characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman Spectroscopy. The prepared PdNPs show efficient surface-enhanced Raman scattering (SERS) properties. SERS studies on the adsorption characteristics of 1,4-phenylene diisocyanide (1,4-PDI) on colloidal PdNPs have revealed that the relative peak intensity of the (NC)_free and (NC)_bound modes distinctly depends on the 1,4-PDI concentration as well as the shape of the PdNPs. Furthermore, we found that the PdNPs are also efficient photoelectron emitters such that the SERS spectrum of 4-nitrobenzenethiol (4-NBT) on PdNPs is readily converted to that of 4-aminobenzenethiol (4-ABT) under 632.8 nm radiation.

In this work, the magnetic arc reduction phenomena encountered in AC relay contacts were analyzed. To this end, arc duration, instantaneous voltage, and current changes due to changes in the magnetic field were observed. The arc generated at the contact point was affected by the magnitude of the applied magnetic field; the voltage and current waveforms rapidly intersected, resulting in a decrease in arc duration and arc energy. Furthermore, the orientation of the N pole of the magnetic field was found to play a role in the effectiveness of potential arc prevention.

Recently, there has been an increasing interest in the use of graphene as electrode materials for supercapacitors. In this regard, graphene oxide (GO) films were prepared using GO slurry obtained by dispersing GO powder in deionized (DI) water. The degree of dispersion of GO powder in DI water depends on the concentration of GO slurry, pH, impurity content, GO particle size, types of functional groups contained in GO, and manufacturing method of GO powder. In this study, the dispersivity of the GO powder was improved by adjusting the pH using only DI water (without additives), and a uniform GO film was obtained. The GO film was reduced by exposure to xenon intense pulsed light for a few milliseconds, and the reduced GO film was used as electrodes of a supercapacitor. The supercapacitor was characterized using cyclic voltammetry (CV), charge-discharge cycle, and electrochemical impedance spectroscopy measurements, and the specific capacitance of the supercapacitor was found to be ~140 F/g from the CV data.

This study examined the size and shape of the nano-silver particle through the analysis of electrical resistance when synthesizing nano-sized silver by using the chemical liquid reduction. Changes in particle behaviors formed according to the changes in electronic characteristics by electric resistance in each time period in the beginning of reduction reaction in a course of synthesizing the nano-silver particle formation were studied. In addition, analysis was conducted on particle behaviors according to the changes in concentration of AgNO3 and in temperature at the time of reduction and nucleation and growth course when synthesizing the particles based on the particle behaviors were also examined. As the concentration of AgNO3 increased, the same amount of resistance of approximately 5 Ω was increased in terms of initial electronic resistance. Furthermore, according to the result of formation of nuclear growth graph and estimation of slope based on estimated resistance, slops of 6.25×10-3, 2.89×10-3, and 1.85×10-3 were derived from the concentrations of 0.01 M, 0.05 M, and 0.1 M, respectively. As the concentration of AgNO3 increased, the more it was dominantly influenced by the nuclear growth areas in the initial phase of reduction leading to increase the size and cohesion of particles. At the time of reduction of nano-silver particle, the increases of initial resistance were 4 Ω, 4.2 Ω, 5 Ω, and 5.3 Ω, respectively as the temperature increased. As the temperature was increased into 23℃, 40℃, 60℃, and 80℃, slopes were formed as 4.54×10-3, 4.65×10-3, 5.13×10-3, and 5.42×10-3 respectively. As the temperature increased, the particles became minute due to the increase of nuclear growth area in the particle in initial period of reduction.