Lithium- and manganese-rich layered oxide (LMRO) is considered a promising cathode material for lithium-ion batteries owing to its high capacity and energy density. However, operation at a high voltage of 4.8 V leads to several issues including low Coulombic efficiency, poor cycle life, slow kinetics, and voltage decay due to spinel phase transition, hindering commercialization. Herein, we synthesized a cobalt-free LMRO cathode and studied the effect of Nb2O5 and Sb2O3 coating layers on electrochemical performance. The Nb2O5 coating facilitated the formation of a LiNbO3 layer, which enhanced the initial electrochemical performance, including Coulombic efficiency and energy density. Meanwhile, Sb2O3 not only coated the surface but also doped into the bulk structure, thereby increasing capacity and improving rate capability. Comparative analysis using materials with different structural solubility revealed how oxide coatings influenced lithium-ion transport and electrochemical behavior. This study highlights the importance of interfacial engineering for optimizing LMRO cathodes for high-performance lithium-ion batteries.
Zinc oxide has attracted attention due to its high functionality, including chemical stability, high biocompatibility, and excellent optical properties. In particular, when the particles are nano-sized, they exhibit new characteristics, making them suitable for application in UV-filters, photo-catalysts and cosmetics. This paper provides an overview of nano zinc oxide used for UV filters, and summarizes domestic and international production technology and the industrial status of zinc oxide nano-powder. First, the concept and principle of the nano-sized zinc oxide manufacturing process is provided, and various types of manufacturing methods are analyzed, namely, wet process, dry process, and powder process. Next, the results of an analysis of the domestic sunscreen market size and company status are provided. The production processes of major domestic companies and their product characteristics, such as particle size, purity, surface treatment, and transparency of the zinc oxide powder being produced, are analyzed and provided. The characteristics of zinc oxide produced for use in sunscreens, both domestically and internationally, can be summarized as follows. Manufactured zinc oxide powder is white or transparent, and particle size typically ranges from 30 to 200 nm on average, although non-nano sized powders have also been developed in recent years. When used as a coating, the surface to be coated is typically treated with substances such as silicone oil or silane, and the powder is formulated into products by dispersing it in oil- or water-based systems.
The utilization of pig slurry (PS) as an organic fertilizer plays a pivotal role in nutrient recycling within agricultural systems. However, this practice concomitantly leads nitrogen (N) losses through ammonia (NH₃) volatilization and nitrous oxide (N₂O) emissions. The objective of this study was to investigate the effect of wood biochar on mitigating NH3 and N2O emissions and enhancing N retention from PS-applied soil, and plant biomass production during the vegetative growth of rapeseed (Brassica napus L.). The experiment consisted of three treatments: 1) water (non-PS), 2) PS, and 3) PS combined with wood biochar (PS+WB). The PS+WB treatment resulted in the maintenance of elevated soil water content during the experimental period. The PS+WB treatment significantly enhanced soil nitrogen retention compared to PS alone, maintaining higher total N and NH₄⁺-N levels while reducing NO₃⁻ -N accumulation. Wood biochar application also leds to substantial reductions in NH₃ and N₂O emissions, mitigating environmental N losses. The PS+WB treatment resulted in an improvement of shoot biomass, crude protein content, and total digestible nutrients, indicating enhanced forage quality. The increased soil moisture content in PS+WB further contributed to plant growth benefits. These findings demonstrate that wood biochar is an effective amendment for improving nitrogen retention, reducing gaseous N emissions, and enhancing crop productivity in PS-amended soils.
목적 : 본 연구는 세륨(IV)-지르코늄(IV) 산화물 나노입자를 사용하여 콘택트렌즈를 제조한 후, 안의료용 기능성 렌즈로의 사용 가능을 확인 위해 제조된 렌즈의 물성을 비교 분석하였다. 방법 : 2-Hydroxyethyl methacrylate에 나노 세륨-지르코늄 산화물(cerium(IV)-zirconium(IV) oxide)을 첨가하여 공중합 한 후 물성을 측정하고, 친수성 단량체인 methacrylic acid(MA)를 추가로 첨가하여 물성을 측정, 비교하였다. 결과 : 다양한 비율의 세륨(IV)-지르코늄(IV) 산화물 나노입자와 MA를 첨가한 렌즈의 물성을 평가한 결과, UV-B 투과율은 40.95~66.26%, 굴절률 1.4163~1.4357, 함수율 37.44~47.18%, 접촉각 36.87~56.36°, 인장 강도 0.0612~0.561 kgf/mm², 표면거칠기 7.70~8.72 nm로 각각 측정되었다. 나노입자 및 MA 첨가는 습윤성, 인장강도 및 중합안정성을 향상시키고, UV-B 투과율과 표면거칠기를 감소시켰으며, 황색포도상구균에 대한 항균 성이 확인되었다. 결론 : 세륨(IV)-지르코늄(IV) 산화물 나노입자에 MA를 첨가하여 제조한 렌즈가 중합 안정성, 내구성, 습윤성 을 향상시키는 것을 확인하였으며, 따라서 안의료용 기능성 콘택트렌즈 소재로 활용할 수 있을 것으로 판단된다.
Background: The poultry industry experiences genetic losses due to recurring infectious diseases, necessitating effective preservation strategies. Nitric oxide plays a crucial role in male reproduction, and optimal NO (nitric oxide) levels may enhance sperm viability. This study investigated the effects of SNAP (S-nitroso-Nacetylpenicillamine) on the longevity of rooster sperm. Methods: Semen was diluted with Beltsville Poultry Semen Extender-I containing 0 or 25 μM SNAP and stored at 10°C. Sperm motility and acrosome integrity were assessed at 1, 3, and 7 days. NO levels were quantified by DAF-FM diacetate and AI trials were evaluated by fertility and hatchability. Results: On day 1, sperm motility in the SNAP 25 μM-treated group was significantly higher than in the control. NO quantification confirmed that SNAP-treated semen exhibited higher NO levels. For fertilization and hatchability assessment, hens were divided into two groups based on the presumed duration sperm resided in sperm storage tubules. Before artificial insemination, the sperm was preserved at low temperature (10°C) to maintain viability. Fertilization rates were significantly higher in the SNAP-treated group in both short-term and long-term SST storage conditions. However, hatchability was only significantly improved in the SNAP-treated group when fertilization occurred after extended storage. Conclusions: These findings suggest that NO enhances sperm viability and fertility in poultry semen stored at low temperatures. SNAP 25 μM enhances AI efficiency by maintaining sperm viability and extending fertilization potential. Further research is needed to refine NO-based fertility enhancement strategies for avian species.
This study focuses on analyzing the impact range of toxicity, overpressure and radiant heat (pool fire and boiling liquid expanding vapor explosion, BLEVE) resulting from a propylene oxide leakage accident and proposes mitigation strategies to minimize damage. A risk assessment was conducted by designing accident scenarios based on variables such as substance quantity and wind speed. The results indicated that toxicity and BLEVE were the primary risk factors, and the risk level increased as the substance quantity increased and wind speed decreased. For future mitigation strategies, it is suggested that a quantitative analysis of vapor dispersion rates and dilution and effects under various environmental conditions be conducted, along with preliminary research on optimizing absorbents and catalytic materials.
Supercapacitors, renowned for their high power density and rapid charge-discharge rates, are limited by their low energy density. This limitation has prompted the need for advanced electrode materials. The present study investigated reduced graphene oxide (rGO) in two distinct structures, as a film and as an aerogel, for use as supercapacitor electrodes. The rGO film, prepared by vacuum filtration and thermal reduction, exhibited a compact, lamellar structure, while the aerogel, synthesized through hydrothermal treatment, was a highly porous three-dimensional network. Electrochemical analyses demonstrated the aerogel’s superior performance, as shown by a specific capacitance of 121.2 F/g at 5 mV/s, with 94% capacitance retention after 10,000 cycles. These findings emphasize the importance of structural design in optimizing ion accessibility and charge transfer. They also demonstrate the potential of rGO aerogels for increasing the energy storage efficiency of advanced supercapacitor systems.
As the pace of technological advances accelerates, the role of electrical energy storage has become increasingly important. Among various storage solutions, supercapacitors are garnering significant attention. Their unique attributes, including high power density, rapid charge/discharge capabilities, and extended lifecycle, position them as a promising alternative to conventional batteries. This study investigates the synthesis of a nickel oxide (NiO) and nickel oxide/graphene oxide (NiO/GO) composite using a single-step hydrothermal method, to evaluate their potential as supercapacitor electrode materials. The synthesized NiO, graphene oxide (GO), and NiO/GO composite were comprehensively characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy to analyze their crystal structures and chemical bonding. The XRD analysis confirmed the formation of an NiO phase with a rhombohedral crystal structure, and no change after GO incorporation. SEM analysis revealed the formation of spherical NiO particles and porous morphology of the NiO/GO composite, which also exhibited a spherical shape. The GO displayed a randomly arranged wrinkled sheet-like structure. Electrochemical analysis of the NiO/GO composite exhibited a remarkable specific capacitance of 893 F g-1 at a current density of 1 A g-1, surpassing that of NiO and GO alone, demonstrating NiO/GO has promising performance for supercapacitor applications. The charge transfer resistance, derived from the Nyquist plot, suggests that the reduction in charge transfer resistance contributed significantly to the improved capacitance. Additional stability studies of over 5,000 cycles at 5 A g-1 revealed an 85 % initial capacitance retention, confirming the advantages of GO inclusion to improve material retention for superior long-term performance. The asymmetric supercapacitor (ASC) assembled using an electrode with the configuration NiO/GO//activated carbon (AC) showed a specific capacitance of 77.8 F g-1 obtained at a current density of 0.5 A g-1.
Hydrogen production via photoelectrochemical water splitting relies on the effectiveness of the photoelectrodes. Preparing low-dimensional structures of oxide semiconductors is a promising approach to fabricating effective photoelectrodes, by enhancing the surface-to-volume ratios of the photocatalytic materials. In this study, we performed a comparative investigation of the photoelectrochemical characteristics of p-type oxide semiconductor cupric oxide (CuO) photocathodes based on CuO thin film and nanorods. The CuO thin film was prepared via a facile method involving sputtering a Cu metallic film and subsequent thermal oxidation, while the CuO nanorods were grown via a seed-mediated hydrothermal synthesis method using a CuO nanoparticle seed layer. The structural, optical, and photoelectrochemical properties of the prepared CuO thin film and nanorods were comparatively examined. Our results confirmed that the CuO nanorod photocathode has a higher photocurrent density and better photoconversion efficiency than the CuO thin film photocathode for photoelectrochemical water splitting, implying a promising route to the fabrication of CuO-based photoelectrodes.
Iron oxide (ε-Fe2O3) is emerging as a promising electromagnetic material due to its unique magnetic and electronic properties. This review focuses on the intrinsic properties of ε-Fe2O3, particularly its high coercivity, comparable to that of rare-earth magnets, which is attributed to its significant magnetic anisotropy. These properties render it highly suitable for applications in millimeter wave absorption and high-density magnetic storage media. Furthermore, its semiconducting behavior offers potential applications in photocatalytic hydrogen production. The review also explores various synthesis methods for fabricating ε-Fe2O3 as nanoparticles or thin films, emphasizing the optimization of purity and stability. By exploring and harnessing the properties of ε-Fe2O3, this study aims to contribute to the advancement of next-generation electromagnetic materials with potential applications in 6G wireless telecommunications, spintronics, high-density data storage, and energy technologies.
The heat transfer characteristics of double-pipe spiral heat exchanger using aluminum oxide nano-fluid were investigated by three different sizes of curvature size, experimentally. Five concentration of nano-fluid as working fluid were made and tested to analyze the heat transfer characteristics. As results, the heat transfer performance was improved at 0.25% of nano-fluid due to high thermal conductivity, however, as the concentration of nanofluid increased (~2.0%), the heat transfer performance deteriorated due to the increase in thermal resistance caused by the sedimentation of particles in the flow path. In addition, the nano-fluid has a higher pressure drop than water due to its high density and viscosity. The optimal range for heat transfer enhancement of nano-fluid was found to be less than 4.0 LPM in flow rate and 0.25% of nano-fluid concentration in this study.