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Functional Polymeric Binders for Interfacial Stabilization of High-Nickel Cathodes in High-Voltage Lithium-Ion Batteries
No full textDynamic Distributed TDMA Resource Allocation Algorithm for Robotic MANETs
No full textRobotic Mobile Ad-hoc Networks (MANETs) face significant challenges in efficiently allocating network resources due to frequent topology changes and varying communication demands. Traditional static TDMA schemes are inade- quate for such highly dynamic environments, leading to inefficient resource usage and communication delays. To address these challenges, we propose D2TRA-RM, a dynamic and distributed TDMA resource allocation algorithm specifically designed for robotic MANETs. Through extensive simulations using NS-3, we demonstrate that D2TRA-RM improves network throughput by 198.7% and reduces packet delay by 59.5% compared to traditional static TDMA. Additionally, D2TRA-RM’s meticulous design for Robotic MANETs outperforms a naïve Dynamic-Distributed TDMA scheme, offer- ing a 125.7% increase in throughput and 68.7% reduction in delay. Although it generates a small number of MAC control messages for negotiation, D2TRA-RM provides substantial gains in network performance, making it a robust solution for real-time, resource-constrained applications in robotic MANET environments. Our results demonstrate that D2TRA-RM effectively handles dynamic traffic and resource reallocation, ensuring efficient communication in highly variable network conditions.
Cocatalyst is matter: Cocatalyst engineering of photocatalysts on hydrogen evolution and carbon dioxide reduction
No full textPhotocatalysis provides a promising and sustainable pathway for converting solar energy into chemical fuels, particularly via the hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CO2RR). The integration of metal cocatalysts with semiconductor photocatalysts offers an effective strategy to enhance three fundamental steps of photocatalysis: light absorption, charge separation, and surface reactions. In this review, we present a comprehensive overview of cocatalyst deposition techniques and engineering strategies, with emphasis on five key parameters-chemical composition, size, morphology, loading density, and spatial distribution. We discuss their individual effects and synergistic roles in governing photocatalytic performance for HER and CO2RR. In addition, we highlight recent progress in the use of in situ characterization techniques, which provide critical insights into dynamic structural and chemical changes of cocatalyst-semiconductor systems under operating conditions. Finally, we outline the remaining challenges-such as long-term stability, scalable synthesis, and mechanistic understanding-and suggest that future advances will be accelerated by integrating in situ techniques with computational approaches and machine learning. This review aims to guide the rational design of next-generation cocatalyst-semiconductor photocatalysts for efficient solar-to-chemical energy conversion.
Enhancement of Mechanical Properties, Adhesion Strength, Ultraviolet Shielding, and Antifungal Effect in Graphene Composite Fibers for Beauty Products
No full text목적: 본 연구는 PBT 섬유에 환원된 산화 그래핀을 복합화하고, 섬유의 단면 형상을 조절하여 경량화, 접착 강도, 기계적 물성, 자외선 차단성, 항곰팡이 특성을 향상시킴으로써 미용 제품용 소재로의 활용 가능성을 평가하는 것에 목적이 있다. 방법: 그래핀을 PBT 고분자에 복합화하고 섬유 단면을 원형 및 십자형으로 제작한 후, 섬유의 경량성, 접착강도, 인장강도, 신도를 분석하였다. 또한, 건열 및 열수 환경에서의 치수안정성, 자외선 차단성과 항곰팡이 효과를 평가하였다. 결과: 섬유 단면 형상이 원형에서 십자형으로 변할수록 섬유의 중량이 감소하여 경량화되었으며, 접착 시 섬유 계면의 상호작용 증가로 인해 접착강도가 향상되었다. 또한, PBT 섬유에 소량의 그래핀을 첨가함으로써 인장강도 및 신도가 개선되었으며, 건열 및 열수 환경에서 치수가 안정적으로 유지되고, 자외선 차단성과 항곰팡이 효과가 확인되었다. 결론: 그래핀 복합화 및 십자형 이형 단면 설계는 섬유의 경량화, 접착강도, 기계적 물성을 효과적으로 향상시켰으며, 치수 안정성, 자외선 차단성, 항곰팡이 효과 또한 확보하였다. 이를 통해 미용 제품용 인조 속눈썹, 메이크업 브러시 섬유로의 실용적 활용 가능성이 기대된다.
Dynamic Material Testing of the Heat Affected Zone in the Large-scale Forging Weld Joint
No full textThe multi-layer welding method using Flux-Cored Arc Welding (FCAW) is widely employed for joining large-scale forging due to its robustness and efficiency. However, the heat-affected zone (HAZ) of the weld undergoes significant changes in microstructure and mechanical properties caused by high temperatures and rapid cooling, which critically impact the overall performance of the welded joint. Furthermore, the small size of the HAZ poses challenges in measuring its mechanical properties. This study proposes experimental methodologies to evaluate the dynamic hardening and dynamic fracture properties of the HAZ. Cross-section analysis and optical microscopy were used to characterize the weld zone geometries and its microstructure. Additionally, hardness tests were conducted to find the localized softening at the HAZ. Finally, tensile and fracture specimens were carefully fabricated considering the location of the small HAZ. Prepared specimens were tested under various strain rates and the hardening and fracture strain of the HAZ was successfully obtained.
Stabilization of Peridynamic Differential Operators Through Diagonal Scaling Preconditioning
No full textCollaborative Scene Mood Authoring with Voice-driven Multimodal Feedback Design in Virtual Reality
No full textBrain water dynamics across sleep stages measured by near-infrared spectroscopy: Implications for glymphatic function
No full textThis study investigates brain water dynamics across the sleep-wake cycle using near-infrared spectroscopy (NIRS) and linear mixed-effects modeling, motivated by prior observations that glymphatic activity increases during non-rapid eye movement (NREM) and decreases during REM sleep. Forty-one healthy volunteers underwent polysomnography with concurrent cerebral NIRS, with measurements taken 30 minutes before sleep, throughout the night, and for 60 minutes after waking. Brain water content (arbitrary unit, A.U.) was block-averaged for 5-minute epochs and analyzed across WAKE -> NREM, NREM -> WAKE, NREM -> REM, and REM -> NREM transitions. Water content significantly increased during WAKE -> NREM (0.57 A.U., d = 0.77, p < 0.001) and decreased during NREM -> WAKE (-0.93 A.U., d = -1.25, p < 0.001). Decreases during NREM -> REM (-0.40 A.U., d = -0.53, p < 0.05) were followed by increases during REM -> NREM (0.62 A.U., d = 1.10, p < 0.001). Brain water accumulation was significantly greater during the first compared to the last NREM cycle (0.70 A.U., d = 0.86, p < 0.01). These findings reveal robust, state-dependent fluctuations in brain water content that parallel established glymphatic physiology. Water-sensitive NIRS may offer a promising non-invasive approach to monitoring sleep-related brain fluid dynamics in humans, though further multimodal studies are needed to determine its specificity for glymphatic activity.
Design of Sub-THz Low-Power and High-Gain Amplifiers Based on Double-Embedded Technique
No full textThis article presents a sub-THz low-power and high-gain amplifier design technique based on a double-embedded pseudo-G(max)-core. The implementation of the double-embedded pseudo-G(max) -core adopts an additional linear, lossless, and reciprocal (LLR) network that satisfies theG(max)-condition for any even or odd number of N-stage cascaded transistor-level pseudo-G(max)-cores which have a stability factor and phase delay of 1 and 2m pi/N, respectively. By utilizing the proposed double-embedded pseudo-G(max)-cores, the amplifiers can achieve a higher gain with a reduced dc power consumption compared to the previously reported double-G(max) core-based amplifier, which can only employ an even number of stages. For proof of concept, two amplifiers are implemented in a 65-nm CMOS process which achieve power gain of 18.2 and 9.3 dB and gain-per-mW of 1.48 and 1.4 dB/mW at 280.2 and 309.2 GHz, respectively.
MANUFACTURING METHOD OF POROUS MAGNESIUM, THE POROUS MAGNESIUM AND HYDROGEN STORAGE MATERIAL
No full text마그네슘 전구체를 환원제 용액에 첨가하여 반응시키는 간단한 용액 공정의 다공성 구조의 마그네슘 제조방법, 상기 제조방법으로 제조된 다공성 구조의 마그네슘 및 상기 다공성 구조의 마그네슘에 담지된 수소를 포함하는 수소 저장 물질을 제공한다