KG Chemical (South Korea)

Background/Objectives: Whole-body vibration (WBV) has been widely studied for its effects on neuromuscular activation, circulation, and balance. This study investigates the effect of wearing frequency of vibrating sneakers (18 Hz) on lower limb muscle activation during walking and squatting in middle-aged Koreans (40–60 years old). The objective is to assess whether WBV footwear enhances muscle engagement in both active and sedentary individuals. Methods: A 16-week randomized controlled trial was conducted with 64 participants divided into exercise (walking 30 min, three times a week) and non-exercise groups. Each group was further divided into wearing and non-wearing vibrating sneaker subgroups. Muscle activation of the quadriceps and gastrocnemius was measured using surface electromyography before and after the intervention. Results: Participants wearing vibrating sneakers showed significantly increased quadriceps and gastrocnemius activation during squatting and walking compared to non-wearers (p < 0.05). The exercise group wearing WBV sneakers exhibited greater improvements in muscle activation than the non-exercise group, indicating that WBV enhances the benefits of regular walking. However, no significant differences were observed in some lower leg muscles, suggesting that WBV effects may vary based on movement type and muscle group. Conclusions: Findings suggest that WBV sneakers (18 Hz) can enhance muscle activation during dynamic movements, potentially offering a low-impact training alternative for improving lower limb strength. These results provide valuable insights for exercise professionals, rehabilitation specialists, and wearable sensor developers, highlighting the potential of WBV footwear in neuromuscular conditioning and injury prevention.

The development of portable X‐ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations. However, this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors. The weight and thickness of X‐ray detectors can be reduced by replacing the silicon layer with an organic photodetectors. This study presents a novel bithienopyrroledione‐based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer (~700 nm), owing to the symmetric backbone and highly soluble molecular structure of bithienopyrroledione. The ability of bithienopyrroledione‐based polymer donor to strongly suppress the dark current density (Jd ~ 10−10 A cm−2) at a negative bias (−2.0 V) while maintaining high responsivity (R = 0.29 A W−1) even at a thickness of 700 nm results in a maximum shot‐noise‐limited specific detectivity of Dsh* = 2.18 × 1013 Jones in the organic photodetectors. Printed organic photodetectors are developed by slot‐die coating for use in X‐ray detectors, which exhibit Dsh* = 2.73 × 1012 Jones with clear rising (0.26 s) and falling (0.29 s) response times upon X‐ray irradiation. Detection reliability is also proven by linear response of the X‐ray detector, and the X‐ray detection limit is 3 mA.

For scaling-down advanced nanoscale semiconductor devices, tungsten (W)-film surface chemical mechanical planarization (CMP) has rapidly evolved to increase the W-film surface polishing rate via Fenton-reaction acceleration and enhance nanoscale-abrasive (i.e., ZrO2) dispersant stability in the CMP slurry by adding a scavenger to suppress the Fenton reaction. To enhance the ZrO2 abrasive dispersant stability, a scavenger with protonate-phosphite ions was designed to suppress the time-dependent Fenton reaction. The ZrO2 abrasive dispersant stability (i.e., lower H2O2 decomposition rate and longer H2O2 pot lifetime) linearly and significantly increased with scavenger concentration. However, the corrosion magnitude on the W-film surface during CMP increased significantly with scavenger concentration. By adding a scavenger to the CMP slurry, the radical amount reduction via Fenton-reaction suppression in the CMP slurry and the corrosion enhancement on the W-film surface during CMP performed that the W-film surface polishing rate decreased linearly and notably with increasing scavenger concentration via a chemical-dominant CMP mechanism. Otherwise, the SiO2-film surface polishing rate peaked at a specific scavenger concentration via a chemical and mechanical-dominant CMP mechanism. The addition of a corrosion inhibitor with a protonate-amine functional group to the W-film surface CMP slurry completely suppressed the corrosion generation on the W-film surface during CMP without a decrease in the W- and SiO2-film surface polishing rate.

SummaryRecently, semitransparent luminescent solar concentrators (LSCs) have attracted considerable attention because they offer an easy and cost‐effective route to harvest incident light. Various fluorophores including semiconducting quantum dots and organic dyes have been prepared and utilized for LSC fabrication. However, the narrow light absorption range, reabsorption losses, and limited photostability of the fluorophores still hinder the widespread use of LSCs under outdoor and indoor light conditions. Here, we rationally designed an LSC utilizing aggregation‐induced emissive fluorophores (AIEgens) and an energy transfer (ET) strategy. We employ diketopyrrolopyrrole with triphenylamine moiety as a highly stable AIEgen that functions as an emissive ET acceptor in LSC; for a donor, we use tetraphenylethene containing triphenylamine moiety that shows good aggregation‐induced emission features and excellent spectral overlap with the acceptor to yield an efficient ET process. A thin‐film LSC device with an optimized donor:acceptor ratio (1:0.5) was fabricated. Under AM 1.5G solar spectrum, an LSC coupled with three side reflectors and a backside diffuser exhibits 18% optical conversion efficiency and a concentration factor of 1.18. Under indoor white LED illumination, the values were 27% and 1.68%, respectively. After exposed to intense UV radiations for 5 hours, the LSCs preserved 98% fluorescence which suggests their superior long‐term photostability. Our results suggest that the combination of AIEgens and ET holds the potential for enhancing the efficiency of the device and extended stability of the fluorophores, two of the major requirements to allow industrial production and large‐scale use of outdoor/indoor light harvesting LSCs.

Abstract Ultra‐deep‐blue aggregation‐induced delayed fluorescence (AIDF) emitters (TB‐tCz and TB‐tPCz) bearing organoboron‐based cores as acceptors and 3,6‐substituted carbazoles as donors are presented. The thermally activated delayed fluorescence (TADF) properties of the two emitters are confirmed by theoretical calculations and time‐resolved photoluminescence experiments. TB‐tCz and TB‐tPCz exhibit fast reverse intersystem crossing rate constants owing to efficient spin–orbit coupling between the singlet and triplet states. When applied in solution‐processed organic light‐emitting diodes (OLEDs), the TB‐tCz‐ and TB‐tPCz‐based nondoped devices exhibit ultra‐deep‐blue emissions of 416–428 nm and high color purity owing to their narrow bandwidths of 42.2–44.4 nm, corresponding to the Commission International de l´Eclairage color coordinates of (x = 0.16–0.17, y = 0.05–0.06). They show a maximum external quantum efficiency (EQEmax) of 8.21% and 15.8%, respectively, exhibiting an unprecedented high performance in solution‐processed deep‐blue TADF‐OLEDs. Furthermore, both emitters exhibit excellent device performances (EQEmax = 14.1–15.9%) and color purity in solution‐processed doped OLEDs. The current study provides an AIDF emitter design strategy to implement high‐efficiency deep‐blue OLEDs in the future.