This study evaluates the potential changes in durability when the next-generation concrete surface (NGCS) method is applied to latexmodified concrete (LMC) for bridge deck pavements. Whereas the NGCS method effectively reduces noise and improves drivability on concrete pavement surfaces, concerns have been raised regarding potential durability degradation due to reduced pavement thickness resulting from surface abrasion and increased exposure to the interfacial transition zone (ITZ). Accordingly, this study utilized field cores obtained from the Incheon Bridge and Beonam Bridge as well as laboratory-mixed specimens with varying latex incorporation rates to test their resistance to rapid chloride penetration, chloride ion diffusion coefficient, accelerated carbonation, freeze–thaw cycles, surface spalling, and abrasion resistance. Experimental results showed that the application of NGCS decreased salt damage resistance due to surface abrasion and increased ITZ exposure. However, the carbonation resistance, freeze–thaw resistance, surface spalling resistance, and abrasion resistance improved owing to the removal of the laitance layer. Furthermore, utilizing LMC bridge deck pavements maintained high watertightness and excellent durability through additional hydration. In particular, all the test results satisfied the quality standards for bridge deck pavements, thus indicating that sufficient durability can be secured even when the NGCS is applied in actual field conditions. Therefore, the NGCS does not significantly degrade the overall durability when applied to LMC bridge deck pavements and is highly feasible in securing long-term serviceability, noise reduction, and improved drivability. The reliability of applying the NGCS can be further improved performing additional long-term monitoring and serviceability evaluations in actual bridge environments in the future.

2000년대 초중반 국내 고속도로 교량에 LMC계 교면포장이 도입된 이후, 우수한 수밀성 및 내구성과 기존 바닥판 콘크리 트와 유사한 열팽창 특성에 기반한 구조적 일체성 확보의 장점으로 신설 및 유지관리 현장에서 폭넓게 활용되어 왔다. 이후 조강·초속경 시멘트를 적용한 다양한 공법이 개발되면서 초기 개방 시간 단축 및 교통 통제 최소화를 위한 기술적 확장이 이루어졌으며, 국내 교면포장 기술은 재료 및 시공 측면에서 지속적으로 발전해왔다. 그러나 준공 후 일정 기간이 경과한 교량에서 들뜸, 탈락, 균열 등 손상이 반복적으로 보고되고 있으며, 이에 따른 장기 공용성 저하와 유지관리 비용 증가 문제 가 제기되고 있다. 기존 연구는 실내 물성시험 및 단기 성능 평가에 집중되어 왔으며, 실제 공용 중인 다수 교량을 대상으 로 교통·환경 인자를 통합 고려한 장기 성능 분석은 제한적인 실정이다. 이에 본 연구에서는 실교량 기반의 공용성 데이터 베이스를 구축하고, 누적 교통하중과 환경하중을 포함한 다양한 인자와 손상지표 간의 통계적 분석을 수행함으로써 LMC 교 면포장의 장기 성능 특성을 정량적으로 평가하고자 한다. 이후 통계적 유의성 검정과 함께, 향후 성능 예측 모델 개발 및 고도화를 통해 성능기반 유지관리 의사결정 체계를 위한 기초 자료로 사용될 수 있다.

In the field of high-end optics, the demand for fluorescent-tunable polymers is increasingly urgent. However, traditional fluorescent materials have limitations including insufficient stability, poor processability, and volatile organic compound (VOC) pollution. In this study, using an improved acetone method synthesis process, Schiff base Cu(II) complexes were innovatively introduced into the main chain of waterborne polyurethane (WPU), to successfully prepare fluorescencecontrollable PMBxCu1-WPU (x = 1, 2, 3), realizing the stable bonding of the Schiff base ligand (PMB) and Cu(II) in the polyurethane chain. The successful synthesis of PMB and the structure of the PMBxCu1-WPU were confirmed by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray powder diffractometer and other testing methods. It was found that the particle size of PMBxCu1-WPU increased by increasing Cu(II) content, and the absolute value of its Zeta potential exceeded 40 mV, showing excellent dispersion stability. PMBxCu1-WPU still maintained good thermal stability, with an initial decomposition temperature of about 220 °C. With the increase in Cu(II) coordination degree, the UV-vis absorption peak undergoes a certain degree of redshift. It is worth noting that after PMB was incorporated into WPU, its emission peak redshifted from 499 nm to 551 nm; with the increase of Cu(II) coordination degree, the emission peak further blue-shifted to 534 nm, which indicates that the fluorescence emission wavelength of PMBxCu1-WPU can be precisely regulated by the coordination degree of Cu(II). This study provides a new method for developing high-performance fluorescent-tunable waterborne polyurethane, and has potential application in the fields of intelligent anti-counterfeiting and biomedicine.

Poor bonding occurs with resin due to surface inertness of carbon fiber (CF), so CF surfaces were often treated. In some common surface treatments, sizing was a simple and effective modification method. Polyurethane (PU) was used as the main component of sizing agents due to its similar structure to polyamide 6 (PA6). The CF/PA6 composites’ interfacial properties were improved using PU as a sizing agent. Meanwhile, in this paper, glycidol (GLD) was introduced into the PU emulsion so that the epoxy group reacted with the carboxyl group on the acidified CF. After testing, when the content of glycidyl in the sizing agent is 2%, the CF/PA6 composites showed an important improvement in tensile, impact, and flexural strengths, which increased by 49.4%, 94.6%, and 53.2%, respectively. In addition, the effect of modified WPU sizing agents with different GLD contents on the properties of CF/PA6 composites was investigated.

Water contamination caused by heavy metal pollutants from industrial activities remains a pressing environmental concern. This study reports the development of a novel carbon paste electrode (CPE) modified with ethylenediaminetetraacetic acid (EDTA), polyvinyl alcohol (PVA), and multi-walled carbon nanotubes (MWCNTs) using a mechanochemical method for the electrochemical detection of Cu(II) ions. The modified electrode was thoroughly characterized to evaluate its functional groups, morphology, crystallinity, elemental composition, and electrochemical properties. Electrochemical measurements were performed using cyclic voltammetry (CV) and square-wave anodic stripping voltammetry (SWASV) under optimized conditions in 0.1 M NH₄Cl at pH 5. The EDTA/PVA/MWCNT-CPE exhibited a low detection limit (0.0457 μM), a wide linear range (0.1–2.7 μM), and excellent reproducibility (RSD = 0.51%), repeatability (RSD = 0.43%), and stability (95% retention after six days). Selectivity tests demonstrated high recovery for Cu(II) (99.7%) and Hg(II) (99.89%) with minimal interference. This simple, cost-effective sensor offers high sensitivity and selectivity, making it a promising candidate for Cu(II) detection in environmental monitoring applications.

Urethral obstruction in male cats, commonly caused by urolithiasis or FLUTD, can be life-threatening. Modified perineal urethrostomy (MPU), connecting the proximal urethra to the preputial mucosa, was performed in three male cats. Two cases with urolithiasis underwent concurrent cystotomy, and one FLUTD case received MPU alone. Two cats recovered uneventfully, while one developed re-obstruction from urinary sludge requiring revision. MPU achieved stable urinary patency and good cosmetic results in most cases, suggesting it as an effective alternative to conventional PU; however, recurrence associated with inflammatory or metabolic causes in FLUTD indicates the need for careful postoperative medical management.

This study examined Korean university students’ ability to distinguish between authentic and modified spoken English texts and their perceptions of each in relation to language learning and content appeal. A total of 125 students completed a questionnaire after listening tasks, assessing their perceptions in three domains: authenticity versus modification, language learning, and content appeal. Questionnaire responses were analyzed using descriptive statistics and independent samples t-tests. The results indicated that participants could distinguish between the two types of texts. Modified texts were rated significantly higher for clarity and fluency, whereas authentic texts were viewed as more reflective of natural speech, including features such as unclear pronunciation and hesitation. Pronunciation clarity, however, was not perceived to significantly influence listening comprehension or difficulty. Participants evaluated modified texts more favorably for supporting language learning, particularly in pronunciation, listening skill development, and content understanding. Both text types were considered similarly effective for comprehending real-life conversations. Regarding content appeal, modified texts were rated as more engaging, though no significant differences emerged in their usefulness for real-life application or new information. These findings highlight the pedagogical importance of using both authentic and modified texts to address diverse learner needs.

본 연구에서는 셀루로오스 나노섬유(CNF) 첨가와 (3-아미노프로필)트라이에톡시실란(APTES)로 표면 처리한 CNF가 시멘트 모르타르 복합체에 미치는 영향을 분석하였다. 일반 시료, 비개질 CNF, APTES 개질 CNF, 그리고 APTES 용액만 첨가한 경우 등 네 가지 조건을 주요 변수로 하여 시험을 진행하였다. 최적 성능은 CNF 0.3 wt%와 APTES 3 vol% 처리 시 나타났으며, 이 조건에서 압축강도와 휨강도가 가장 높게 나타났다. SME, XRD, FT-IR 분석 결과, 처리된 CNF가 수화 생성물과 균일하게 분산되고 화학적으로 결합함을 확인할 수 있었다. 이러한 결과를 통해 ATPES 처리로 CNF의 보강 효과가 시멘트 복합체의 역학적 성능을 크게 향상시킴을 확인할 수 있었다. 따라서 CNF 0.3 wt%와 APTES 3 vol%의 혼입 비율이 시멘트 복합체의 기계적 성능을 향상시키는 가장 효과적인 최적 배합비로 확인되었다.

Capacitive deionization (CDI) represents a novel technology for the desalination and purification of seawater. Selecting the appropriate electrode material is crucial, with carbon electrodes frequently employed owing to their high specific surface area, extensive porous structure, and environmentally sustainable nature. This study presents a nitrogen-doped porous carbon, derived from household waste, which demonstrates outstanding electrochemical and desalination performance. The purified chitosan was mixed with a specific ratio of CaCO3 and carbonized at 800 °C to produce chitosan porous carbon (CPC-T). To verify the role of the templating agent, its performance was compared with chitosan porous carbon (CPC) prepared by direct carbonization. CPC-T possesses more mesoporous structures (31.25%), shortening ion transport pathways and significantly enhancing charge transfer rates. The nitrogen-rich doping (8.65 at%) provides numerous active sites and excellent conductivity, making it highly appropriate for capacitive deionization applications. Compared to CPC prepared without a templating agent, CPC-T has a higher specific capacitance (101.5 F g− 1 at a scan rate of 2 mV s− 1) and good cycling stability. The CDI cell made from it exhibits a salt adsorption capacity (SAC) of 25.8 mg g− 1 for 500 mg L− 1 NaCl solution at an applied voltage of 1.4 V, retaining 88% capacity after 50 adsorption–desorption cycles, demonstrating excellent desalination regeneration performance. Additionally, among different concentrations of salt solutions, the CPC-T material shows the best desalination performance for the test solution at a concentration of 500 mg L− 1. For different solute ions, the CDI cell with this material as the electrode exhibits excellent desalination performance for Ca2+, with a SAC value of up to 34.02 mg g− 1. This is a self-doped porous carbon material that significantly outperforms traditional carbon-based materials.

Enhancing the energy storage capabilities of supercapacitors (SCs) while preserving their electrochemical performance is crucial for their widespread application. Our research focuses on developing Sb-modified tin oxide (ATO) nanoparticles via a scalable hydrothermal process, offering substantial potential in this domain. The tetragonal nanoparticle structure provides abundant active sites and a highly porous pathway, facilitating rapid and efficient energy storage. Additionally, tin's varied oxidation states significantly enhance redox capacitance. Electrochemical measurements demonstrate ATO's promise as an advanced SC electrode, achieving a peak specific capacitance of 332 F/g at 3 mA/cm2, with robust redox capacitance confirmed through kinetic analysis. Moreover, the ATO electrode exhibits exceptional capacitance retention over 2000 cycles. This study establishes ATO as a leading candidate for future energy storage applications, underscoring its pivotal role in advancing energy storage technologies.

The catalyst materials 0N-Cu-MOF, 1N-Cu-MOF, and 2N-Cu-MOF were successfully synthesized usinga solvothermal method, and using different concentrations of nitrogen-modified Cu organic frameworks (xN-Cu-MOF). Characterizations using X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) surface area analysis showed that 1N-Cu-MOF had the largest SSA and pore size among the three materials synthesized. 1N-Cu-MOF exhibited the largest pore size and specific surface area among the three materials, which had a decisive effect on CO2 reduction. In addition, stability and CO2 reduction reaction (CO2RR) activity were evaluated by linear sweep voltmeter, cyclic voltmeter, electrochemical impedance spectroscopy, and time flow tests. Faradaic efficiency (FE) was determined by product analysis. Among the three catalyst materials, 1N-Cu-MOF showed the best catalytic performance at 50 mA･cm-2 (maximum current density). The charge transfer resistance was 8.23 Ω, the average current density was 19.9 mA･cm-2, and the FE of methane (CH4) production showed a high efficiency of 70.45 % when tested for 12 h at an overpotential of -0.35 V (to-RHE).

Porcine edema disease (ED) is an enterotoxemia of pigs caused by Escherichia coli that produces Stx2e. In this study, the protective efficacy of a recombinant modified Stx2e toxoid was evaluated as a vaccine candidate against ED in piglets. The recombinant Stx2e toxoid was expressed and purified using a commercial E. coli expression system. A total of 25 piglets were used and divided into 5 groups (A to E), with 5 piglets in each group. All piglets (except those in group A) were intramuscularly immunized at 5 days of age (0 weeks post prime immunization; 0 WPPI) and again at 3 weeks of age (2 WPPI). Group B piglets were inoculated with sterile PBS, while groups C to E were immunized with 25 μg/piglet, 50 μg/piglet, and 100 μg/piglet of the recombinant toxoid, respectively. All piglets in groups B to E were orally challenged with virulent wild-type Stx2e⁺ F18⁺ E. coli isolates at 5 weeks of age (4 WPPI). Serum IgG titers in groups D and E were significantly increased from 2 WPPI until the end of the study. Furthermore, no clinical signs were observed in groups A and E during the 7 days following the challenge, while clinical signs of ED were observed in 80%, 60%, and 20% of piglets in groups B, C, and D, respectively. These results indicate that intramuscular vaccination with 100 μg/piglet of the recombinant modified Stx2e toxoid can provide effective protection against ED in piglets.