4-Nitrophenol (4NP) is a vital intermediate in organic industries, and its exploitation creates serious environmental issues. We propose a fluorescence quenching-based strategy with nitrogen and sulfur co-doped carbon dots (NS-CDs) for highly sensitive 4NP detection with excellent selectivity. The NS-CDs are produced through the hydrothermal process, in which citric acid serves as a carbon source and cysteamine hydrochloride as a source of N and S. The effect of doping was also studied by synthesizing undoped CDs and examining their properties. As-developed NS-CDs exhibit a bright cyan blue color with maximum emission centered at 465 nm. The fluorescence of NS-CDs is significantly quenched in an approximately linear fashion with increasing 4NP concentration (7.5–97.5 μM). The inner filter effect (IFE) and static quenching (SQ) between NS-CDs and 4NP are responsible for such fluorescence reduction. The fluorimetry technique enables the quantification of 4NP with a limit of detection (LOD) of about 0.028 μM. Moreover, the fluorescence quenching is tested for several other chemical compounds but they generate false quenching signals; only 4NP leads to fluorescence quenching of NS-CDs, demonstrating excellent selectivity. The “turn-off” fluorescence properties and visually apparent color change of the fluorescent probe reveal the excellent performance for 4NP sensing. The NS-CDs’ capability of quantifying 4NP in real water samples (tap water and drinking water) produces an excellent recovery rate ranging between 96.24 and 98.36%.

With the digitalization of production and consumption environments, consumers are no longer merely targets of marketing, but key players in creating value jointly with companies by participating in various decision-making processes. Much virtual content in particular, such as fashion shows, exhibitions, games, social activities, and shopping, which fashion brands implement in virtual worlds, cannot be completed without consumers’ active engagement and interaction. Thus, this study considers consumers’ participation in virtual content provided by fashion brands as value co-creation in virtual worlds. This study aims to examine how consumer (i.e., consumer smartness) and fashion firm (i.e., perceived intellectual capital) factors influence value co-creation behavior intention in virtual worlds. Data were collected from 410 consumers in their 20s nationwide through an online survey, and a higher-order structural equation modeling analysis was conducted to test the research model. The results showed that both consumer smartness and perceived intellectual capital positively influenced customer participation behavior and citizenship behavior intentions. Specifically, perceived intellectual capital had a greater impact on value co-creation behavior in the virtual world than consumer smartness. The findings provide empirical evidence that the fashion firms’ intangible assets and consumers’ competence in the digital shopping environment encourage their intentions to co-create value in virtual worlds.

Hindwings of many lycaenid butterflies have a unique tail-like wing structure referred to as a false head, which actually mimics the antennae. False heads increase butterfly survival by directing predatory attacks towards the false heads thereby enhancing the chance of escape. In this study, using discrete character evolution models of European and American butterflies, we examined the co-evolutionary patterns between false head structures and two associated traits: a highly contrasting color patch neighboring the false head, and hindwing rubbing behaviors. The former is considered a eye-mimicking structure that enhances the effectiveness of false head, and latter generates the movement of false heads which likely increases the success of false head deception. Our findings demonstrate that false heads are ancestral states for both European and American lycaenids. Both contrasting colors and hindwing rubbing behaviors follow correlated evolution models, suggesting that these traits co-evolved in lycanid butterflies. However, specific evolutionray patterns differed between the two continents.

Over four years (2020–2023), 305 traps were strategically placed across South Korea to collect data on Vespidae species. Our findings showed that Vespula flaviceps, Vespa crabro, and Vespula koreensis were the most frequently encountered species. Vespa velutina was also widespread, suggesting its successful integration into local ecosystems. The ARL analysis, using the “apriori” algorithm, identified significant co-occurrence patterns and potential interactions. The rules generated indicated both competitive and coexistent relationships with varying levels of association strength across different regions. Clustering analyses, including hierarchical and k-means clustering, grouped species based on their occurrence similarities. The distinct clusters formed in the analysis highlighted the unique ecological roles and interactions of V. velutina and other Vespidae species in South Korean ecosystems.

As the limitations of Moore’s Law become evident, there has been growing interest in advanced packaging technologies. Among various 3D packaging techniques, Cu-SiO2 hybrid bonding has gained attention in heterogeneous devices. However, certain issues, such as its high-temperature processing conditions and copper oxidation, can affect electrical properties and mechanical reliability. Therefore, we studied depositing only a heterometal on top of the Cu in Cu-SiO2 composite substrates to prevent copper surface oxidation and to lower bonding process temperature. The heterometal needs to be deposited as an ultra-thin layer of less than 10 nm, for copper diffusion. We established the process conditions for depositing a Co film using a Co(EtCp)2 precursor and utilizing plasma-enhanced atomic layer deposition (PEALD), which allows for precise atomic level thickness control. In addition, we attempted to use a growth inhibitor by growing a self-assembled monolayer (SAM) material, octadecyltrichlorosilane (ODTS), on a SiO2 substrate to selectively suppress the growth of Co film. We compared the growth behavior of the Co film under various PEALD process conditions and examined their selectivity based on the ODTS growth time.

자율주행차량의 첨단 운전자 보조 시스템(ADAS)의 발전은 자율주행차량의 상용화를 가속화하고 있지만, 그 안전성을 입증하기 위한 충분한 테스트와 검증이 필요하다. 실제 차량을 이용한 대규모 테스트는 비용과 시간뿐만 아니라 다양한 시나리오를 구현하고 평가하 는 데 어려움이 있어, 다수의 연구자들은 시뮬레이션을 활용하고 있다. 이러한 문제를 해결하기 위해, 본 연구에서는 차량 시뮬레이션 소프트웨어인 CarMaker와 교통 흐름 시뮬레이션인 VISSIM을 결합하여 공동으로 시뮬레이션을 진행한다. 또한 두 시뮬레이션의 장점 을 결합하여 자율주행차량의 데이터를 보다 포괄적으로 분석할 수 있는 프레임워크를 제안한다. 시뮬레이션 결과, 각각의 시뮬레이션 에서 얻은 Ego Vehicle의 속도 값은 미세한 차이를 보였으며, 이는 실시간 시뮬레이션의 통신 과정에서 발생하는 오류로 해석된다. 또 한, 특정 시나리오에서는 차량이 급정지 후 출발하는 형태를 보였으며, 이는 자율주행차량이 주변 차량의 주행을 인식하여 주행 패턴 에 변화를 주는 것으로 해석된다. 향후에는 도심 도로에서의 자율주행 평가를 통해 복잡한 교통 상황과 불확실한 요소들로 인해 어려 운 문제를 겪는 상황을 분석할 수 있을 것으로 기대된다.

A semi-natural composite of κ-carrageenan and bentonite, two natural biopolymers, was synthesized through free radical polymerization. This synthesis aimed to obtain a biodegradable, biocompatible, and swellable composite that is environmentally friendly. The components used in this synthesis are readily available, making it economically feasible and promising for potential biomedical applications. The composite is pH-responsive and intended for oral delivery of metformin hydrochloride and aminophylline, which have low bioavailability and undesirable side effects, respectively. The organic composite exhibits the advantage of reducing drug release in the acidic gastric medium. This composite is a stimuli-responsive polymeric material that has garnered significant attention in recent years for its application in oral drug delivery systems. These materials enable site-specific and controlled drug release while minimizing toxicity. The carrageenan-g-poly(acrylamide-co-acrylic acid)/bentonite composite was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM), which confirmed the successful synthesis of the composite. The swelling behaviour and point of zero charge of the composite were studied at different pH values, which showed a strong influence on the swelling properties of the composite. The drug loading capacity of the composite was measured at pH 5.3, and it was 70.60 mg/g for metformin and 95.66 mg/g for aminophylline at pH(3). The in vitro release profile of both drugs from the composite was also affected by the ionic strength, and it exhibited a lower release rate with higher salt concentration. The maximum release percentage of the drugs from carrageenan-g-poly(acrylic acid-acrylamide)/bentonite in simulated gastric, intestinal, and colon fluids was achieved within 40 h. The maximum release was 80% for metformin in simulated intestinal fluid (SIF) and 75% for aminophylline after 40 h.