Personalized air exhaust combined with mixing ventilation for environmental management and airborne droplets in a train cabin DOI
Renze Xu, Fan Wu, Lian Shen

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

The enclosed space and high passenger density in high-speed train cabins pose substantial challenges providing a safe, healthy, comfortable indoor environment, especially during pandemics such as COVID-19 influenza. High ventilation rates, while beneficial reducing pathogen transmission, may compromise airflow field quality result great energy consumption. Therefore, understanding the tradeoffs between transmission risk, thermal comfort, saving is critical for devising cabin systems. As primary method of regulating environments, heating, ventilation, air conditioning systems are central to this study, which proposes an improved personalized mode that combines exhaust with various supply strategies. results indicate considerably reduces longitudinal spread particles rapidly decreases their concentration air. When paired higher proportion entering through sidewall outlets, primarily diffuses upward. proposed enhances balances consumption quality, delivers significant performance improvements, including 22.4% increase utilization efficiency over 23.3% reduction suspended droplets. This study provides theoretical foundation optimizing post-pandemic era.

Language: Английский

Reversible Swell–Shrink Hydrogel Microspheres for High-Selectivity Digital SERS Analysis of Nonvolatile Fentanyl in Simulated Breath Aerosols DOI
Yuzhu Li, Zhongxiang Ding, Hongyan Wang

et al.

Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

In clinical diagnostics, human breath presents an alternative and more convenient sample than biofluids for detecting the ingestion of nonvolatile drugs. Surface-enhanced Raman spectroscopy (SERS) is a powerful vibrational technique with high sensitivity based on molecular fingerprinting. However, low affinity traditional SERS substrates aerosols stochastic fluctuation signal at concentrations limit their application in aerosol analysis. this study, we synthesized hydrogel microsphere highly reversible swelling/shrinking properties that enhance target analyte accumulation promote plasmonic nanoparticle aggregation intense hotspot formation. Furthermore, these function as three-in-one system, enabling multilevel selectivity size, charge, hydrophilicity molecules simultaneously without pretreatment. Notably, by "digitizing" each individual calculating proportion positive microspheres, microspheres can serve digital platform circumvents stability issues resulting from fluctuations intensity. Consequently, achieved detection 0.5 ppm fentanyl simulated aerosols. This innovative sensing strategy not only demonstrates promising approach screening drugs but also simplifies sampling process, holding great potential diagnosis

Language: Английский

Citations

0
Personalized air exhaust combined with mixing ventilation for environmental management and airborne droplets in a train cabin DOI
Renze Xu, Fan Wu, Lian Shen

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

The enclosed space and high passenger density in high-speed train cabins pose substantial challenges providing a safe, healthy, comfortable indoor environment, especially during pandemics such as COVID-19 influenza. High ventilation rates, while beneficial reducing pathogen transmission, may compromise airflow field quality result great energy consumption. Therefore, understanding the tradeoffs between transmission risk, thermal comfort, saving is critical for devising cabin systems. As primary method of regulating environments, heating, ventilation, air conditioning systems are central to this study, which proposes an improved personalized mode that combines exhaust with various supply strategies. results indicate considerably reduces longitudinal spread particles rapidly decreases their concentration air. When paired higher proportion entering through sidewall outlets, primarily diffuses upward. proposed enhances balances consumption quality, delivers significant performance improvements, including 22.4% increase utilization efficiency over 23.3% reduction suspended droplets. This study provides theoretical foundation optimizing post-pandemic era.

Language: Английский

Citations

0