Ta-Chih (TC) HSIAO | 蕭大智

Research

In the past years, I have conducted several NSC/MOST projects and can be classified into 3 categories:
Aerosol Instrumentation, Atmospheric Aerosol & Ambient Monitoring, PM & Nanoparticle Toxicity.

Aerosol Instrumentation:
Cyclone

(MS. Student: P.K. Chang, W.C. Fang; 開發低耗能混合型靜電旋風集塵器用於去除次微米顆粒物/國科會/NSC 99-2218-E-008 -016)

     We reviewed and detail examined different effects of geometric configurations on cyclone performance (including cyclone’s cutoff size, pressure drop, and the steepness of sampling curve) in this study. This is significant because all these findings of different geometric effects are valuable for designing and optimizing tangential flow cyclones. Therefore, the outcome of this study provided a comprehensive understanding of the effects of these cyclone’s longitudinal and radial dimensional ratios on cyclone’s cutoff size and pressure drop as well as the steepness of sampling curve. The research findings should be of interest to researchers in the areas of developing new cyclone and to who would like to improve/optimize cyclone performance.

 

  1. Ta-Chih Hsiao*, Sheng-Hsiu Huang, Chia-Wei Hsu, Chih-Chieh Chen, Po-Kai Chang. Effects of the geometric configuration on cyclone performance. Journal of Aerosol Science, 2015, 86, 1-12.

  2. Liu, D., Hsiao, T. C., & Chen, D. R*. Performance Study of a Miniature Quadru-inlet Cyclone. Journal of Aerosol Science, 2015, 90, 161-168.

  3. Hsu, Chia-Wei; Huang, Sheng-Hsiu; Hsiao, Ta-Chih; Lin, Wen-Yinn; Chen, Chih-Chieh*, An Experimental study on Performance Improvement of the Stairmand Cyclone Design, Aerosol and Air Quality Research, 2014, 14, 1003-1016.

  4. Ta-Chih Hsiao, Da-Ren Chen*, Paul Greenberg, and Kenneth W. Street, Effect of Geometric Configuration on the Collection Efficiency of Axial Flow Cyclones, Journal of Aerosol Science, 2011, 42, 78-86.

 

APM Performance Evaluation

(MS. Student: Y.C. Tai; 氣懸微粒構型與密度之量測分析及應用於大氣環境監測/國科會/NSC 102-2221-E-008 -004 -MY3) 開發低耗能混合型靜電旋風集塵器用於去除次微米顆粒物/國科會/NSC 99-2218-E-008 -016)

     Effective density is one of important parameters in predicting the particle transport behavior and fate in the atmosphere, in the human respiratory tract and in measurement instruments (Ristimӓki, J. et al., 2002). The aerosol particle mass analyzer (APM) for determining the effective density of aerosol particles was first proposed by Ehara et al. (1996), and a compact design (Kanomax APM-3601) was developed by Tajima et al. (2013). This study evaluated the effect of gas viscosity on APM performance theoretically and experimentally. The transfer function and the APM operation region were also calculated and discussed for examining the performance.Through the cooperation with the other investigators on measuring aerosol optical properties, large-scale aerosol transportation modeling, and particle chemical composition analysis, the effects of aerosol morphology can be studied and the research findings could be applied to clarify the aerosol effect in climate model. The morphology of internal or external mixed aerosol may also be explored, and the soot aggregates could be generated in Lab to test our system. Hygroscopic behavior of fractal particles could be different from spherical particle and can be studied using our generation system and experimental scheme.

 

  1. Yu-Chun Tai and Ta-Chih Hsiao*, Effect of Gas Viscosity on Performance of Aerosol Particle Mass Analyzer, 2015 Asian Aerosol Conference, Kanazawa, Japan, Jun. 24-26, 2015.

  2. 戴于鈞、蕭大智*、楊禮豪, 以APM-SMPS系統量測氣膠微粒之有效密度, 第21屆國際氣膠科技研討會 暨 細懸浮微粒(PM2.5)監測與管制策略研討會, 國立中山大學, Sep. 26-27, 2014.

     

 

Virtual Impactor

(MS. Student: P.K. Chang ; 設計與模擬一高流量之氣膠濃縮器並應用於細懸浮微粒採樣/環保署/MOST 105-EPA-F-005-004)

     For PM2.5 the size-selective inlet and sampling techniques will directly affect the measurements of PM mass concentration and the results of following chemical analysis. For example, when the concentration of air pollutants in ambient environment is low, the sampling time must be extended for collecting enough mass of PM for further studies. However, this would reduce the temporal resolution of measurements and data interpretation. In addition, the PM instruments’ operating are generally fixed and not adjustable. In order to overcome the issue of “low” PM concentration and to increase the temporal resolution, the aerosol concentrator is introduced. Currently the virtual impactor was generally used as an aerosol concentrator for concentrating particles with large Stokes number. In this study, the flow field and particle trajectory of existing virtual impactor, designed with different configurations, under different operation flow will be simulated and analyzed using the commercialized CFD software, COMSOL Multiphysics. Effects of flow and slit geometry, including the total flow (Qin), the ratio of minor to total flow (r), the taper slip nozzle and the collection probe configuration, will be investigated. Based on the knowledge learned from these numerical experiments, the new PM size selective inlet and the aerosol concentrator for ambient PM studies will be proposed. At last, the experimental tests will be conducted to validate the numerical simulation results.

ESP type ALI (Air-Liquid Interface) Cell Exposure System

(MS. Student: Y.C. Chang Chien, W.C. Fang, J.C. Lin ; 空氣中奈米微粒直接進行細胞株危害性測試可行性評估/勞研所/IOSH 1003080, 開發電噴霧帶電技術之靜電集塵式氣液介面細胞暴露系統並評估其應用於非球形態微粒之效能/MOST 106-2221-E-008-009-MY2)

     In recent years, the air-liquid direct/air-liquid interface (ALI) exposure method is considered as a more realistic experimental scheme for in vitro cell exposure to airborne particles. In this study, we will review the current reported ALI exposure methods to investigate their potential issues, challenges and limitations. Second, the feasibility and the potential of utilizing an ALI exposure method for in vitro cell exposure to nano-particles (NP) will be evaluated, and a prospective experimental system/method will be proposed for establishing the standard process. Moreover, a newly-designed ESP-type ALI exposure chamber and system was also constructed, and its performance was evaluated under different operating conditions. The effects of different geometric dimensions and operating conditions were characterized. The preliminary results demonstrated the ALI chamber /system designed in this study is a promising and feasible method for in vitro cell exposure to nano-particles (NP).