Cheorwon Plasma Research Institute

This study investigated the effects of four LED light qualities, red+blue+far-red (WRS-LED), blue+red (BR-LED), blue (B-LED), and red (R-LED), and exogenous L-glutamic acid at 10 ppm on the growth and quality of red mustard spinach (Brassica rapa var. perviridis) cultivated in a plant factory using a recirculating deep-flow hydroponic system. Plants were exposed to four LED light quality treatments at 180 ± 10 μmol·m−2·s−1 PPFD for 28 days after transplanting. L-glutamic acid at 10 ppm was applied once to the recirculating nutrient solution 15 days after transplanting, resulting in 13 days of exposure prior to final harvest on day 28. All growth and quality parameters were measured at the final harvest after 28 days of cultivation. WRS-LED promoted the greatest biomass production. Additionally, vitamin C content, DPPH radical scavenging activity, and total phenolic content were highest under BR-LED and B-LED conditions. Notably, under B-LED, L-glutamic acid treatment increased total phenolic content to approximately twice that of the control. Leaf redness, expressed as Hunter a* values, was observed exclusively under BR-LED. Principal component analysis revealed that LED light quality was the primary determinant of treatment responses, with growth-related traits associated with WRS-LED and R-LED, and quality-related traits with B-LED and BR-LED. Overall, BR-LED combined with L-glutamic acid represents the most suitable treatment for red mustard spinach cultivation in plant factories, achieving a favorable balance between growth and nutritional quality.

Sodium‐ion batteries (SIBs) are emerging as promising alternatives to lithium‐ion batteries owing to the abundance of sodium resources and the limited supply of lithium raw materials. However, the development of high‐performance anode materials remains a critical challenge owing to the relatively low initial coulombic efficiencies (ICEs) and limited reversible capacities of conventional carbon‐based anodes. Herein, hard carbon (HC) from mangrove wood was synthesized via controlled carbonization, and its electrochemical performance was systematically investigated. HC prepared by carbonization at 1200 °C (MWHC‐1200) exhibited the best performance, delivering a high reversible capacity of 266.6 mAh g −1 and an ICE of 75%. Pitch‐derived soft carbon coatings (containing 5, 10, or 15 wt% pitch) were applied to HC synthesized at the optimal carbonization temperature to further enhance Na + ‐storage performance. Notably, the composite containing 10 wt% pitch (PC‐10) exhibited the best electrochemical performance, delivering a high reversible capacity of 291.5 mAh g −1 , an ICE of 82%, a capacity retention of 90.4% after 200 cycles, and an excellent rate capability. These improvements were associated with the suppression of irreversible reactions and improvement in interfacial stability. This study offers a simple yet effective approach for improving the electrochemical properties of biomass‐derived HC and provides insights into the design of practical SIB anodes.

Biodiesel, predominantly derived from canola oil, isrecognizedas an essential renewable and ecofriendly fuel, significantly reducinggreenhouse gas emissions and fossil fuel dependency. Despite its advantages,optimizing catalytic reactions remains challenging. This researchsystematically evaluates the catalytic efficiency and selectivityof three homogeneous heteropoly acids (HPAs)phosphotungsticacid (PWA), phosphomolybdic acid (PMo), and silicotungstic acid (SiW)forbiodiesel production using canola oil. Under the optimized homogeneousreaction conditions, the Brønsted acidity was quantitativelyanalyzed using UV–vis spectroscopy with 4-nitroaniline, whilesolvent-dependent dissociation characteristics were confirmed viaFT-IR spectroscopy. Among the HPAs, PWA and PMo exhibited higher methanolsolubility, correlating to significantly greater FAME yields (43.97%and 47.22%, respectively) compared with SiW (21.81%). Product analysisrevealed that W-based catalysts (PWA, SiW) predominantly producedpolyunsaturated esters such as C18:3 (65.9% and 67.5%, respectively),while PMo favored monounsaturated esters such as C18:1 (55.1%), reflectingintrinsic differences in acidity and catalyst configuration. Effectivebiphasic separation using dichloromethane and water facilitated catalystrecovery and product purification, with FT-IR confirming HPAs’retention in the aqueous phase. This study underscores the necessityof concurrently managing catalyst solubility and acidity to optimizebiodiesel production and product selectivity using homogeneous HPAs,in which the process of efficient phase separation is an advantagefor effective management.

Abstract In this study, SiOx/spherical graphite (SiOx/SG) composites were successfully prepared as high-performance anode materials for lithium-ion batteries through the combination of thermal plasma and ball milling approach. The thermal plasma method enabled the production of SiOx nanoparticles with controlled morphology and particle size, ensuring high purity and homogeneity. These nanoparticles were then uniformly dispersed into spherical graphite (SG) via ball milling, forming a composite with enhanced structural stability and electrochemical performance. The resulting SiOx/SG composite exhibited superior electrochemical properties, including high specific capacity, excellent cycling stability, and improved rate capability. This synergistic approach offers an efficient, scalable, and industrially viable route for developing advanced anode materials for next-generation lithium-ion batteries.

This study was conducted to investigate effects of LED light quality on the growth and photomorphogenesis of basil (cv. ‘Amethyst Improved’) in a closed-type plant factory. Basil was sown on a urethane sponge and grown for two weeks under a White-LED. When the first main leaf appeared, the plants were transplanted into a nutrient solution hydroponic system (24 ± 2 °C, RH 55±10%) and using a standard nutrient solution for leafy vegetables (N 17.3, P 4.0, K 8.0, Ca 8.0, Mg 4.0, S 4.0 me·L-1). To compare growth and internal traits of basil under various light qualities, QD-LED (combining blue, red, and far-red light), Blue+Red-LED (blue and red wavelengths at a ratio of 1:3), White-LED, 100% Blue-LED, and 100% Red-LED were used to cultivate basil for 35 days. Photosynthetic photon flux density (PPFD) was 200 ± 10 μmol·m-2·s-1 and the light was provided for 16/8 hours (Light/Dark). The plant height was significantly the longest at 26.1 cm in QD-LED, and the number of leaves was the highest at 16.00 ea in QD-LED, but not significant. The leaf length was the longest at 10.9 cm in QD-LED and the shortest at 8.10 cm in White-LED. The leaf width was up to 26% wider in Blue+Red-LED, but there was no statistical significance. The leaf thickness was the thickest at 0.33 mm for Blue+Red-LED and Red-LED, which have a high proportion of red light, and the thinnest at 0.26 mm for Blue-LED. In the case of the curvature index (CI), which indicates the morphological characteristics of basil leaves, the values were highest for Blue+Red-LED and Red-LED. The internode length and leaf stalk length were significantly the longest at 5.73 cm and 3.04 cm, respectively, for QD-LED, and the stem diameter at 5.26 mm for QD-LED. The shoot fresh weight was 26.0 g in QD-LED, which was significantly higher than the other treatment groups by up to four times, but the root fresh weight was the highest at 5.99 g in Blue+Red-LED. On the other hand, the shoot and root dry matter ratio were the highest at about 9% and 5%, respectively, in White-LED. The maximum quantum yield (FvFm) did not differ significantly between the treatment groups, but the value was significantly lowest at 0.79 for Red-LED. The chlorophyll content (SPAD), normalized difference vegetation index (NDVI), and anthocyanin reflectance index (ARI1) values were up to 27% higher in Blue+Red-LED than in other treatment. Also, the DPPH radical scavenging activity and total phenol content were the highest in Red-LED at 74% and 9.47 mgGAE·g-1FW, respectively. As a result, basil (cv. ‘Amethyst Improved’) grew best in QD-LED, and its antioxidant effect was the best in Red-LED. In addition, it was confirmed that the curvature and morphological characteristics of basil leaves changed depending on the ratio of red light at 600-700 nm.

The relationship between the ZnO aspect ratio (AR) and the piezoelectric performance of the composite piezoelectric nanogenerators (PNGs) has not been clearly identified, especially theoretically. Herein, we developed a multiphysics simulation considering the mechanical and electrical coupling mechanism to identify the theoretical mechanism for the relationship. In addition, a strategy to control the ZnO AR according to the synthesis conditions was adopted to minimize changes in the chemical composition that could affect the consistency of the experimental results when compared to theoretical results. The ZnO AR increased from 3.3 to 26.3 as the growth temperature increased from 65 to 95 °C at the optimum growth time of 60 min. The piezoelectric current/voltage of the composite PNGs was improved by 1367/232 and 650/516% by repetitive mechanical force and hammer stamping, respectively, according to the increased AR of randomly dispersed ZnO. From the developed simulation, which can successfully describe these experimental results, it was demonstrated that the increased AR was advantageous for large deformation of ZnO, continuous stress transfer and piezoelectric potential generation in the composite PNG. • Theoretical simulation quantifying piezoelectric potential of PNGs was developed • ZnO NP, NR and NW were synthesized by controlling hydrothermal process conditions • Piezoelectric output of the composite PNGs was improved according to the ZnO AR • From the simulation, the improved output was mainly due to large deformation of ZnO

Core-shell colloidal nanocrystals (CNCs) are promising candidates for photoelectrochemical (PEC) photocathodes due to their strong light absorption, tunable bandgaps, and efficient charge separation. In this study, we developed a simple and versatile strategy for fabricating narrow-bandgap shells compatible with various core materials. Among the configurations tested, the matrix-type MoS x shell demonstrated the most effective performance, significantly enhancing photocurrent generation and operational stability through improved surface defect passivation and charge carrier separation. Band-level engineering further enabled the formation of reverse type-I heterojunctions in both CdSe and CIS2 CNCs. Although type-II systems are traditionally favored for charge separation, our results show that the reverse type-I architecture not only enhances photocarrier separation under standard illumination but also effectively suppresses dark current. This is attributed to the dual physical and electronic passivation provided by the reverse type-I structure, which stabilizes the core-shell interface and reduces nonradiative recombination. Notably, the Cu2O/CuO/red CIS2 CNCs with a high indium ratio achieved the highest photocurrent density and retained over 86% of their initial performance after 24 hours of continuous operation at -0.1 V vs. RHE, demonstrating excellent long-term stability. These results highlight the strong potential of matrix-type reverse type-I core-shell CNCs as efficient and durable photocathode materials for PEC applications.

The surface morphology of Mg-Al-layered double hydroxide (LDH) was successfully controlled by reconstruction during systematic phase transformation from calcined LDH, which is referred to as layered double oxide (LDO). The LDH reconstructed its original phase by the hydration of LDO with expanded basal spacing when reacted with water, including carbonate or methyl orange molecules. During the reaction, the degree of crystal growth along the ab-plane and stacking along the c-axis was significantly influenced by the molecular size and the reaction conditions. The lower concentration of carbonate gave smaller particles on the surface of larger LDO (2000 nm), while the higher concentration induced a sand-rose structure. The reconstruction of smaller-sized LDH (350 nm) did not depend on the concentration of carbonate due to effective adsorption, and it gave a sand-rose structure and exfoliated the LDH layers. The higher the concentration of methyl orange and the longer the reaction time applied, the rougher the surface was obtained with a certain threshold point of the methyl orange concentration. The surface roughness generally increased with the loading mount of methyl orange. However, the degree of the surface roughness even increased after the methyl orange loading reached equilibrium. The result suggested that the surface roughening was mediated by not only the incorporation of guest molecules into the LDH but also a crystal arrangement after a sufficient amount of methyl orange was accommodated.