The potential release of toxic metals such as Li, Ni, and Co into aquatic environments is increasing due to the growth of the lithium-ion battery (LIB) industry and the expansion of recycling processes. In this study, the 24-h acute toxicity of Li, Ni, and Co was evaluated in both single-metal exposures and binary mixture using Daphnia magna. Single-metal toxicity showed the highest toxicity for Co, followed by Li and Ni. Mixture toxicity results indicated antagonistic interactions in the Li-Ni and Li-Co combinations, whereas a strong toxicity enhancement was observed for the Ni-Co combination. Nonlinear interaction patterns dependent on fixed concentrations and concentration ratios were also identified. These findings highlight the limitations of simple additivity assumptions and provide fundamental data for mixture-based ecological risk assessment related to LIB recycling activities.

Al–Mg co-doped ZnO thin films were fabricated by a sol–gel spin-coating process to investigate the effect of dopant ratio on their structural, electrical, and optical properties. The total dopant concentration was fixed at 3 mol%, while the Al-to-Mg ratio was systematically varied in AlxMg0.03-xZn0.97O (0 ≤ x ≤ 0.03). X-ray diffraction analysis showed that the films maintained a hexagonal wurtzite structure with a preferred (002) orientation up to an Al concentration of 1.5 mol%, whereas higher Al contents resulted in a degradation of crystallinity due to exceeding the solid solubility limit of Al in the ZnO lattice. Hall effect measurements revealed a decrease in carrier mobility with increasing Al content, attributed to enhanced ionized impurity scattering, while the carrier concentration and electrical conductivity reached optimal values at an Al–Mg co-doping ratio of 1.5 mol%–1.5 mol%. All films exhibited high optical transmittance in the visible region, with the highest average transmittance of approximately 83% observed at the same composition. These results demonstrate that controlling the Al/Mg dopant ratio is crucial for optimizing the performance of ZnO-based transparent conducting oxide thin films.

In this study, the influence of bimodal WC particle size design on the microstructure and mechanical properties of WC–27 wt.% Mo₂C–10 wt.% Co cemented carbides was systematically investigated. Bimodal hard-phase designs were realized by combining ultrafine WC (300 nm) and coarse WC (1.8 μm) at various ratios, followed by consolidation via spark plasma sintering (SPS). During sintering, Mo₂C preferentially dissolved into the Co-rich liquid phase due to its higher solubility than WC, forming a Co–Mo–C liquid. As sintering progressed, ultrafine WC selectively dissolved owing to its high interfacial energy, gradually transforming the liquid composition into a Co–Mo–W–C system. Owing to the short holding time and rapid cooling rate of SPS, the η-phase (M₆C) formed during sintering remained metastable. Meanwhile, selective dissolution–reprecipitation resulted in the formation of Mo₂C-based core–rim structures with W enrichment in the rim region as (Mo, W)₂C. As the fraction of ultrafine WC increased, the hardness increased from 1769 to 1997 kgf/mm2, whereas the fracture toughness exhibited an insignificant difference from 6.56 to 6.65 MPa·m¹/². Fracture behavior analysis revealed that crack deflection and crack bridging occurred at the Mo₂C core–rim interfaces, effectively suppressing straight crack propagation. These results demonstrate that the introduction of ultrafine WC plays a dominant role in enhancing mechanical performance, and that bimodal WC design combined with Mo₂C addition is a highly effective strategy for developing high-performance cemented carbides for machining

The co-sintered phosphor of cerium-doped yttrium aluminum garnet (YAG:Ce) and aluminum nitride (AlN) is a promising material for next-generation light-emitting diode lighting applications. Despite AlN’s excellent thermal conductivity, its high sintering temperature and surface reactivity limit its industrial use in co-sintered phosphors, and effective methods to improve its sinterability without compromising properties remain underexplored. In this study, the sinterability of the AlN and YAG:Ce composite is improved by coating AlN particles with a soluble carbon material (SCM) prior to sintering. SCM coating leads to a 6.75% increase in photoluminescence (PL) intensity under 15 W laser excitation and a 6.85% improvement in thermal conductivity, which suppresses thermal quenching. The enhanced thermal conductivity also minimizes PL decay over time, thereby maintaining high luminosity for extended periods. Furthermore, the hardness and handling properties of the obtained sintered body are significantly improved, with hardness increasing by 112.3% when SCM-coated AlN is used. Notably, the SCM does not remain in the final product, as it is fully removed during sintering, leaving no impurities or adverse effect on the material’s properties. Given its ability to easily and uniformly coat ceramic particles, SCM coating holds promise for broader application in enhancing the sinterability and performance of various ceramic-based materials.

Medium- and low-temperature coal tar pitch can be prepared as coal-based mesophase pitch for its high value-added utilization. However, its lower aromaticity and higher content of heteroatoms (especially O atoms) led to a higher content of the resulting mesophase pitch mosaic structure. In this study, mesophase pitch was prepared by co-carbonization of high aromaticity, low oxygen content high-temperature refined pitch (RHCTP) with medium- and low-temperature coal tar refined pitch (RCTP). The impact of various blending ratios on the optical and microcrystalline structures of mesophase pitch was analyzed using polarized light microscopy, X-ray diffraction, and Raman spectroscopy. The addition of RHCTP to modify RCTP significantly enhanced the optical and microcrystalline structures of the co-carbonized products. The optimal blending ratio (R-25%) was obtained. Needle coke prepared from mesophase pitch obtained from R-25% had superior fine fiber structure, lowest average resistivity (157.37 μΩ·m) and high true density (2.125 g/cm3). The thermal conversion behavior of the blended refined pitch during co-carbonation was analyzed using thermogravimetric data of the R-25% sample through four isoconversion methods. The thermal conversion of the R-25% sample occurs in three stages: the first stage follows the Parabola law model, while the second and third stages adhere to the random nucleation and nuclei growth model. This analysis of thermal conversion kinetics offers theoretical insights for optimizing mesophase pitch preparation process conditions and reactor design.

This work introduces a high-performance absorber based on a lightweight composite material of corn straw biochar and magnetic cobalt nickel zinc ferrite. A composite absorber of corn straw biochar with hierarchical pore structure and magnetic zinc cobalt nickel ferrite particles (Ni–Co–Zn ferrite/C) was prepared by a simple two-step approach of carbonization followed by in-situ growth method. The morphology, structure, function, and absorbing properties of the prepared samples were characterized, and RCS simulation was performed. The results show that the optimal reflection loss value of Ni–Co–Zn ferrite/C-2 reaches −38.04 dB when the layer thickness is 3.5 mm, and the effective absorption bandwidth is 4.32 GHz. The potential of Ni–Co–Zn ferrite/C-2 composite material in stealth applications is verified. It is mainly attributed to the excellent impedance matching performance caused by the multi-level pore structure and the strong polarization loss caused by the rich heterogeneous interface and active sites, which plays a key role in the attenuation of electromagnetic waves. This study provides a useful reference for the design of magnetic ferrite particles/metal oxides/biomass-derived carbon microwave absorbing materials with hierarchical porous structure characteristics.

Due to the severity of environmental degradation and depletion of natural energy resources, research on sustainable energy storage systems have become quite popular. Supercapacitor is one of the most innovative and promising type of energy storage devices. The effective performance of supercapacitor greatly depends on the electrode material. Therefore, new type of nanocomposite has been fabricated with βCD-stabilized CuO nanoparticles (CuO-βCD NPs) on Co-Al layered double hydroxide (Co-Al LDH) utilizing solvothermal process. The wet impregnation technique facilitates the formation of three distinct CuO-βCD/Co-Al LDH nanocomposites in the ratios of 1:1, 1:2, and 2:1 by promoting the growth of CuO-βCD on Co-Al LDH in corresponding compositions. Synthesized nanocomposites are characterized using a variety of spectroscopic techniques. The average pore size of 2:1 CuO-βCD/Co-Al LDH is 1.7 nm whereas the specific surface area and approximate pore volume of this nanocomposite are 38.306 m2 g− 1 and 0.043 cm3 g− 1, respectively. Electrochemical investigations like cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopic (EIS) measurements and along with cycle stability studies are performed to examine the electrochemical performance of synthesized nanocomposites. The 2:1 ratio has revealed improved specific capacitance (SC) of 1567 F g− 1 at 0.45 A g− 1 in 1 M potassium hydroxide medium in three electrode systems and maintains 76% of its original SC even after 5000 cycles. The improved electrochemical performance of 2:1 ratio reveals the appropriateness of this material as an effective electrode for supercapacitor application.

Nasopharyngeal stenosis (NPS) is an uncommon but potentially life-threatening condition in cats, capable of causing complete upper airway obstruction in severe cases. Carbon dioxide (CO₂) laser staphylectomy provides precise tissue ablation with minimal collateral thermal injury; however, restenosis could occur when used as a sole treatment modality. Balloon dilation can temporarily restore luminal patency, yet recurrence rates remain high when performed alone. This report describes an 8-month-old Korean Shorthair cat with complete nasopharyngeal stenosis that underwent CO₂ laser ablation as an initial intervention, followed by rapid restenosis within three days. A second procedure combining CO₂ laser ablation with endoscopic balloon dilation achieved short-term maintenance of nasopharyngeal patency. These findings suggest that, in cases of complete stenosis with a high risk of recurrence, a multimodal approach may be more effective than single-modality treatment.

Small VTOL platforms envisioned for Urban Air Mobility (UAM) require compact and high–disk-loading propulsion systems, for which coaxial propellers are a suitable option. While counter-rotating coaxial propellers have been widely studied due to their torque-cancellation advantages, combined experimental and CFD-based research on coaxial co-rotating systems remains limited. This study investigates the aerodynamic performance of such a system using RANS-based CFD simulations, complemented by parallel experiments for validation. A pair of 18-inch, two-bladed propellers was arranged in a stacked layout, with mounting angle and inter-rotor spacing treated as key design variables. Results indicate that rotor–rotor interference leads to a maximum Figure of Merit (FoM) of 0.51 when the upper rotor leads at H/D = 0.07 and index angle of +15°. Increasing axial spacing generally improves the performance of both the upper and lower rotors, with the maximum thrust of 17.5N obtained at H/D = 0.07 and +45°. These performance trends were confirmed experimentally, and differences between CFD predictions and measurements remained within 5% for thrust and 6% for torque, demonstrating strong agreement. This study identifies influential design parameters for coaxial co-rotating propeller systems and provides a validated numerical methodology, offering a useful foundation for future high-efficiency Electric Distributed Propulsion System (EDPS) development.

This study analyzed changes in annual growth and carbon dioxide uptake before and after planting of four major deciduous broadleaf tree species (Prunus serrulata Var. spontanea, Zelkova serrata, Chionanthus retusus, and Quercus acutissima) planted as part of the Geumgang Riverside Ecological Belt Development Project. The study site was selected as an ecologically restored site that had been established for at least 10 years. The diameter at breast height and tree age were measured, and annual growth rates were calculated through tree ring analysis. Based on these data, annual carbon dioxide (CO2) uptake was estimated using the IPCC (2006) formula. The study results showed that all four species experienced a sharp decline in growth immediately after planting, followed by a gradual recovery, though the timeframes varied for each species. Based on the growth analysis results, the average annual CO2 uptake by species was calculated to range from 5.48 to 14.38 kg CO2 y-1, with cherry trees showing the highest values. CO2 uptake before and after planting increased for all four species, with the rate of increase accelerating over time. Furthermore, the time required to recover or exceed the CO2 absorption level before planting varied depending on the tree species, ranging from two years at the shortest to six years at the longest. The zelkova tree took the longest at six years. As such, tree growth is a crucial factor influencing annual CO2 absorption, demonstrating the need to differentiate management periods based on the growth characteristics and recovery rate of each tree species. In particular, trees in urban and riparian ecological restoration areas provide not only direct carbon absorption but also indirect greenhouse gas reduction effects, such as heat island mitigation and energy savings. Therefore, they can serve as important baseline data for establishing future management strategies for urban forests and ecological restoration areas.

중국어 구말조사에 대한 연구는 중국어학계의 지속적인 주목을 받아 왔으며, 선행 연구자들은 다양한 언어학 이론을 바탕으로 이에 대한 유의미한 탐구를 수행해 왔다. 그 결과 중국어 구말조 사에는 여러 기능적 특징이 부여되었으나, 서로 다른 층위의 기능적 특징들이 혼재되면서 오히려 논의가 복잡해지는 문제도 나타났다. 본고는 ‘어기’범주의 초기 개념과 분류를 토대로, [+주요 문장 유형 분포], [+양태 범주], [+발화행위적 기능], [+발화행위력 조정], [+주관성], 그리고 [+상호 주관성]을 매개 변수로 삼아 학계의 일반적인 구말 어기사 연구 성과를 정리·귀납하고, 나아가 기능문법 이론(TFG)과의 결합을 통해 중국어 구말조사의 중복 사용 원인을 구명하고자 한다.

본 연구는 중국의 AI 국가 전략이 공공서비스 분야에 미친 영향과 그 이면에 내재 된 윤리적 쟁점을 인문학적 관점에서 분석한다. 중국은 2017년 ‘차세대 인공지능 발 전계획’을 통해 AI를 국가 핵심 기술로 지정하고, 국가 주도형 데이터 통제 및 투자 를 통해 공공서비스의 비약적인 효율성 증대를 달성했다. 스마트시티 및 스마트 복 지 행정 사례는 이러한 기술적 성과를 입증한다. 그러나 중국의 AI 모델은 효율성 증대와 개인의 자유보다 사회 안정과 국가 통제를 우선하는 국가 통제형 윤리 모델 이라는 이중성을 지닌다. 특히 사회신용시스템(SCS)과 같은 감시 시스템은 개인의 프라이버시를 침해하고, 감시 사회화 위험을 내포한다. 따라서 본 논문은 중국 사례 를 통해 효율성 중심의 기술 만능주의를 경계하고 인간 중심의 가치를 최우선으로 하는 민주적 AI 거버넌스 프레임워크 구축의 필요성과 공공소통 방안을 제언한다. 이는 기술 발전이 인간의 존엄성을 훼손하지 않고 공공선에 기여하기 위한 필수적인 인문학적 성찰이다.

본 연구에서는 페나진(phenazine) 구조를 갖는 고분자인 PIM-7을 합성하고, 그 특성과 전기화학적 거동을 평가하 여 CO2 포집을 위한 산화·환원 활성 고분자 플랫폼으로서의 가능성을 검토하였다. 합성 과정에서는 5,5',6,6'-tetrahydroxy- 3,3,3',3'-tetramethyl-1,1'-spirobisindane의 케톤화 유도체(TTSBI-ketone)를 아세톤 재결정으로 정제하여 순도를 향상시 켰으며, 이를 통해 단계성장 중합이 안정적으로 진행되었다. 최종 고분자의 구조는 FT-IR 및 NMR 분석을 통해 확인하였다. 질소 흡착 분석 결과, PIM-7은 약 519 m2/g의 높은 BET 비표면적을 보여 기체 접근성이 좋은 미세다공성 골격을 형성하고 있음을 알 수 있었다. 또한 cyclic voltammetry 측정에서는 CO2가 존재할 때 PIM-7 복합 필름의 환원 전류가 선택적으로 증 가하는 현상이 관찰되었으며, 이는 환원된 페나진 중심과 CO2 사이의 상호작용에 따른 것으로 해석된다. 이러한 CO2 반응성 은 여러 주사 속도와 반복 측정 조건에서도 일관되게 유지되었고, 이는 해당 산화·환원-CO2 상호작용이 단순 표면 현상이 아 니라 고분자 자체의 고유한 특성임을 보여준다. 이와 같은 결과는 PIM-7이 고체 상태에서 전기적으로 제어 가능하며, 미세다 공성을 갖춘 산화·환원 기반 CO2 포집 소재로 활용될 수 있음을 제시한다.

전기화학적 탄소 포집은 에너지 집약적인 열역학적 공정에 대한 유망한 대안으로, 등온 운전 및 재생 에너지원과 의 통합을 가능하게 한다. 그러나 주로 드롭 캐스팅 기술에 의존하는 현재의 전극 제조 방식은 확장성을 제한하고 활물질과 전도성 물질 사이의 불균일한 계면으로 인해 전도 경로의 효율을 저해한다. 본 연구에서는 확장 가능한 전기화학적 탄소 포집 응용 분야를 위해 전기화학적 CO2 반응 특성을 가짐과 동시에 용액 공정이 가능하고 산화-환원 활성을 가지는 폴리이미드 (redox-active polyimides, RAP)의 첫 번째 사례를 보고한다. 합성된 RAP는 N-메틸-2-피롤리돈(N-methyl-2-pyrrolidone, NMP) 및 N,N-디메틸포름아미드(N,N-dimethylformamide, DMF)와 같은 유기 용매에서 우수한 용액 가공성을 보였으며, 용해도는 산화-환원 활성 유닛을 가지는 단량체의 조성에 따라 달랐다. 질소 및 이산화탄소 포화 조건에서 수행된 순환 전압전류법 실 험을 통해 CO2 대기 조건에서 반파 전위의 뚜렷한 변화를 관찰하였으며, 이는 RAP의 CO2 분자와의 반응성을 입증해주는 결 과이다. 용액 가공성, 산화-환원 활성, CO2 반응성의 조합은 RAP를 대규모 전기화학적 탄소 포집 시스템에서 활용 가능한 유 망한 후보로 자리매김하여 효과적인 CO2 제거 성능을 유지하면서 전극 호환성과 제조 확장성 측면에서 중요한 과제를 해결 할 수 있다.

Covalent organic framework (COF) membranes have emerged as promising candidates for hydrogen purification due to their tunable pore sizes and robust structures. However, achieving high selectivity and permeability simultaneously remains a challenge due to the inherent pore size distribution of COF materials. In this study, we fabricated two distinct COF membranes, TpPa-1 and TpTGCl, with pore sizes of 1.8 nm and 0.39 nm, respectively, using tailored synthesis methods. The TpTGCl membrane, synthesized via room temperature interfacial polymerization and vacuum-assisted filtration, exhibits an ultrathin nanosheet structure with an interlayer π–π stacking distance of 0.33 nm. This unique architecture, combined with its affinity for CO2 adsorption, enables exceptional hydrogen separation performance, achieving a H2/ CO2 selectivity of 52.5 and a H2 permeability of 3.49 × 10– 7 mol m− 2 s− 1 Pa− 1. Molecular dynamics simulations confirmed the steric hindrance effect as the primary mechanism for the selective permeation of hydrogen. The TpTGCl membrane effectively sieves larger gas molecules ( CO2, N2, CH4, etc.) without the need for material modification or excessive membrane thickness. This study demonstrates the potential of COF membranes with tailored pore sizes for high-performance hydrogen purification and offers valuable insights for the development of advanced separation technologies.

Combining CuPc with semiconductor materials as organic‒inorganic hybrid photocatalysts can effectively improve the light absorption capacity and separation efficiency of photogenerated electrons and holes in semiconductor photocatalysts. Herein, a CuPc/Bi2WO6 Z-scheme heterojunction was successfully designed and used for CO2 photoreduction. The separation of photogenerated electrons and holes is greatly enhanced because of the formation of a compact organic‒inorganic heterointerface and the built-in electric field between CuPc and Bi2WO6, which increases the photocatalytic CO2 reduction efficiency. Moreover, the photosensitizer CuPc can effectively enhance the light absorption of Bi2WO6. The optimal 1CuPc/ Bi2WO6 composite exhibits the best photocatalytic performance, with a CO production rate of 2.95 μmol g− l h− 1, which is three times greater than that of Bi2WO6 under visible-light irradiation. This work provides a new idea for the construction of an organic‒inorganic photocatalytic system for CO2 reduction.

Photocatalytic reduction of CO2 into fuels offers a promising avenue to tackle present energy challenges and mitigate global warming. At present, TiO2 has been widely used in photocatalytic CO2 reduction reactions, and element doping can optimize the band structure of TiO2 to improve the efficiency of photocatalytic CO2 reduction. In this work, TiO2 doped with different content of N was prepared using TiN as the precursor through a simple one-step calcination method. Under optimized conditions, the optimal CO yield of the modified photocatalyst is 41.1 μmol g− 1 h− 1, which is 8 times higher than that of p25 type TiO2. Density functional theory (DFT) calculations confirmed that N-doping can reduce the band gap of TiO2 and decrease the Gibbs free energy of CO2 reduction reaction. In-situ-XPS indicated that N-doping can enhance the activation of CO2 by enriching photo generated electrons. Additionally, In-situ-FTIR spectra were employed to detect intermediates and track variations in the consumption of H2O and CO2, providing deeper insights into the mechanism responsible for enhancing efficiency. Our work addresses the deficiencies of the past and provides more detailed theoretical insights for the accelerated photocatalytic reduction of CO2 by N-doping TiO2.

A considerable amount of the food is wasted each year, creating an urgent global problem with negative economic and environmental effects. Livestock manure, a by-product of intensive animal farming, can contribute to environmental issues if not properly managed. While biochar, a product of pyrolysis, can speed up the composting process and improve compost quality, sawdust is frequently used in composting to balance the carbon-to-nitrogen ratio. This study aimed to investigate the effects of biochar on compost quality in co-composting food waste and swine manure and the influence of raw materials in obtaining good quality ecofriendly compost. Experimental manipulations were conducted both with feedstock materials present and absent. The findings revealed that a biochar concentration of 6% had a positive impact on the composting process. Furthermore, the presence or absence of feedstocks influenced the composting rate and the quality of the compost. Through the addition of biochar, moisture balance and porosity were improved, promoting the growth of beneficial microorganisms. Organic waste can be managed more sustainably and agricultural systems may be improved by keeping it out of landfills and composting it with biochar. According to this study, a proper balance of feedstock composition is equally important to the addition of biochar. The study contributes to the understanding of the composting process and the role of balancing feedstock components for the production of good quality compost.

A hierarchical porous carbon/silicon composite material (CSCM) was prepared through KOH activation and acid leaching using coal gasification fine slag (CGFS) as the raw material. The KOH dosage, activation temperatures, and HCl acid amount were optimized. The obtained CSCMs showed higher pore volume in the range of 0.62–0.96 cm3/ g, and hierarchical porous structure with Vmicro./ Vmeso. ratio in the range of 1.54–3.31. The influence of Vmicro./ Vmeso. ratio of CSCM on CO2 adsorption at 0 °C was higher than that at 25 °C. Under higher specific area and pore volume, hierarchical pores with Vmicro./ Vmeso. ratio in the range of 2.81–2.91 were benefit for CO2 adsorption at 0 °C. The optimized CSCM demonstrated excellent CO2 adsorption capacities of 2.96 and 4.60 mmol/g at 25 and 0 °C, respectively. CO2 adsorption on CSCM was a heterogeneous physical process, and the cycle stability was excellent. Meanwhile, CSCM was mixed with Fe-based catalyst (Fe-K/CS) for CO2/ H2 catalysis. The hierarchical porous structure of CSCM improved the CO2 adsorption and H2 adsorption around the active sites, promoting CO2 conversion. The combination method of Fe-K and CSCM affected the distribution of CO2 hydrogenation products, and reasonable Vmicro./ Vmeso. ratio in CSCM effectively inhibited C–C chain growth, leading to higher olefins selectivity. The Fe-0.1K/CS-P catalyst achieved a CO2 conversion rate of 21.6% and a C2 =-C4 = selectivity of 47.7%. This study presented a promising approach for effectively utilizing CO2 and for the sustainable valorization of industrial solid waste.