https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/167 2026-07-24T05:53:12Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/212898 Title: Physical interaction pressure between wearers and back exoskeletons during repetitive lifting Authors: Lei, Ting; Heung, Kelvin Holam; Seo, Joon Oh; Kim, Hyunsoo Abstract: Lower back pain is a widespread occupational hazard among construction workers, causing health and economic burdens. Industrial back exoskeletons provide support to reduce spinal strain, but excessive interaction pressures-the localized contact pressures between wearer and device-limit applicability. This study quantifies interaction pressure magnitude and distribution for four back exoskeletons (Laevo FLEX, IX BACK, SV Exosuit, Laevo V2.5) during controlled repetitive lifting representative of construction tasks. Pressure sensors recorded at upper body (chest for Laevo V2.5; shoulder for others), thigh, and lateral waist (excluding SV Exosuit). Lightweight active SV Exosuit produced the lowest standing pressures. Waist belts offload thigh pressures and enhance stability but create high localized pressures and shift torque to the waist. Chest interfaces distribute loads yet can restrict breathing and cause fit issues. Thigh comfort depends on pad size, strap design, and waist configuration. Findings identify design trade-offs and guide targeted optimizations to reduce pressures and improve comfort. 2026-09-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/218431 Title: Assessing the applicability of 5th-generation district heating and cooling for energy-efficient retrofits in a net zero energy campus Authors: Choi, Won-Jong; Lee, Wangje; Kim, Jongkyu; Jeong, Jae-Weon; Kim, Min-Hwi Abstract: This study evaluated the techno-economic and environmental performance of 5th-generation district heating and cooling systems across 13 cases. Key performance indicators included the levelized cost of heat, seasonal coefficient of performance, primary energy consumption, and CO2 emissions. The results showed that the seasonal coefficient of performance values for the 5th-generation district heating and cooling system cases ranged from 4.5 to 4.85, reflecting higher efficiency compared to conventional air-source heat pumps. It leads to the reduction of primary energy consumption and CO2 emissions by up to 45%. Economic performance improved particularly in cases with a larger proportion of data-center cooling load. INT-1 achieved the lowest LCOH of 0.105 $/kWh, which was 9.5% lower than that of the Base case. It also found that the cases with decreased reliance on external heat sources and increased utilization of waste heat recovery also showed lower system capacity requirements and investment costs. This study concluded that load composition optimization and efficient waste heat utilization are key design variables for enhancing the performance and economic viability of 5th-generation district heating and cooling systems. 2026-09-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213278 Title: Comparative assessment of hexavalent chromium (Cr(VI)) immobilization in cement pastes with copper, steel, granulated blast-furnace, and ferronickel slags Authors: Kim, Gyeongryul; Sim, Sungwon; Cho, Seongmin; Jee, Hyeonseok; Kim, Min Kyoung; Kwon, Seung-Jun; Bae, Sungchul Abstract: Hexavalent chromium (Cr(VI)) is a highly toxic and mobile contaminant that requires effective stabilization in cement-based waste treatment systems. This study comparatively evaluates the Cr(VI) immobilization behavior of cement pastes incorporating four metallurgical slags: copper slag (CS), steel slag (SS), ground granulated blast-furnace slag (GGBFS), and ferronickel slag (FNS), with focus on chemistry-controlled mechanisms. Cr(VI) was introduced in the form of K2CrO4, and immobilization characteristics were examined through phase analysis, spectroscopic techniques, and leaching tests. The results indicate that CaO-rich slags promote the formation of Cr-bearing phases, including CaCrO4, CrO4-substituted AFt/AFm phases, and calcium (alumino)silicate hydrates, which contribute to chromate retention and partial reduction to Cr(III). In contrast, MgO-rich FNS limits the development of key hydrate phases and shows lower stabilization performance despite comparable strength. Phase quantification and chromium valence analysis show consistent agreement with leaching behavior, suggesting that hydrate assemblage and calcium availability play a more decisive role than mechanical performance in governing immobilization efficiency. Toxicity characteristic leaching procedure (TCLP) results confirm higher Cr(VI) retention in CaO-rich slag (SS and GGBFS) systems compared with CaO-deficient slags (CS and FNS), as well as 100% cement paste. These findings provide mechanistic insight into chromium stabilization in cementitious matrices and support the use of selected industrial slags as alternative low-carbon binders for hazardous waste immobilization. 2026-08-01T00:00:00Z https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/218440 Title: Experimental study of liquid-desiccant–evaporative cooling for data Center heat recovery Authors: Lee, Soo-Jin; Sim, Jae Woo; Park, Min-Geon; Lee, Jae-Hee; Kim, Dong Rip; Woo, Je Sang; Kim, Eui Jin; Jeong, Jae-Weon Abstract: This study presents an experimental evaluation of a rack-level cooling system that integrates rear door heat exchangers with liquid desiccant dehumidification and evaporative cooling to improve thermal efficiency and waste heat utilization in data centers. A test platform simulating a 20 kW server rack was constructed to compare a conventional system with the proposed configuration under humid outdoor conditions. The proposed system recovers approximately 98% of condenser heat, of which about 63% is functionally reused for desiccant regeneration, achieving a total heat recovery utilization rate of 62%. Compared to the baseline, the proposed system reduced cooling-related electricity consumption by up to 29%, primarily due to reduced refrigeration power demand. Results also show lower condensing pressure and compression ratio, leading to improved coefficient of performance and power usage effectiveness. The findings highlight the potential of liquid desiccant-assisted cooling for enhancing energy efficiency and heat reuse in hot and humid climates. 2026-08-01T00:00:00Z