David Y.H. Pui’s research while affiliated with University of Minnesota and other places

... The F-5 sample exhibits filtration efficiencies of 85.88%, 95.57%, and 96.64% for PM2.5, PM5, and PM10, respectively, while the F-10 sample shows efficiencies of 72.85%, 89.65%, and 80.75%. The exceptional filtration efficiency of the LO/PCL fiber membranes can be attributed primarily to the slip effect of the nanofibers [36,37]. When air or gas passes through the nanofiber membrane, the extremely small fiber diameter alters the interaction between the fluid and the fibers compared to traditional flow behavior at the macro scale. ...

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Lavender Essential Oil‐Loaded Composite Fiber Membrane Prepared by Coaxial Electrospinning for High‐Performance, Antibacterial, and Lasting‐Fragrance Air Filtration

... Ozone is a common byproduct of generating air ions, and the amount of ozone generation increases with the strength and type of ionization. Methods to reduce ozone generation include using low-voltage or "soft ionization," selecting ozone-free ionizers, combining ionization with filters, proper ionizer placement, timed operation, active ozone control, and utilizing non-ozoneproducing ionization technologies [5,6,[30][31][32][33][34]. The toxicity of ozone is a function of its concentration, and exposure can lead to numerous long-term and short-term effects, causing damage and complications in the lungs and respiratory system [35,36]. ...

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Combined Intervention Removes More Aerosols From the Environment—A Quantitative Assessment

... This inclusive approach ensured a comprehensive examination of the performance of FEM monitors across various concentration levels. Furthermore, our assessment operated under the assumption that the FRM deployed at each site represented a true value when compared to PM 2.5 continuous monitoring, despite acknowledging the inherent uncertainty (e.g., evaporation loss due to the volatile properties of semivolatile species in PM 2.5 collected on the after-filter associated with FRM measurements [19,20]. ...

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Evaluation of Fine Particulate Matter (PM2.5) Concentrations Measured by Collocated Federal Reference Method and Federal Equivalent Method Monitors in the U.S.

... Interestingly, although academic genealogy is most often visualized as groups of branches at the top converging to a single root below, this genealogy is traced back from the root (or, the subject of interest) through individual branches and scholarly relationships that helped shape the academic ancestry of this individual. This article endeavors to chronicle the academic lineage of Richard J. Goldstein, who was himself a pioneer in the field of heat and mass transfer and is considered by many to be the father of film cooling [1]. ...

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Tracing the Academic Lineage of Richard J. Goldstein

... where U 0 denotes the face velocity (m s −1 ); denotes the solidity of a filter; t is the filter thickness (m). For NF-2 in the transition regime, our previous work [39] by fitting simulation results considering the slip effect on the nanofiber surface with a nonlinear regression with a similar formula of Brown's equation gives ...

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Experimental and Numerical Investigation of Slip Effect on Nanofiber Filter Performance at Low Pressures

... The wafer fabrication stage is particularly intensive in terms of resource use and is the main source of air pollution within semiconductor manufacturing [13]. Etching and deposition processes emit persistent, highly toxic fluorinated gases, while chemical vapor deposition and plasma etching release particulate matter and other hazardous byproducts [27]. In comparison, back-end processes such as chip packaging and testing contribute comparatively lower emissions but still release significant quantities of VOCs and heatrelated pollutants [28,29]. ...

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Sustainable Transition of the Global Semiconductor Industry: Challenges, Strategies, and Future Directions

... The device geometry and micro-structural morphology is controlled during the filter production in order to optimize its performance. It was demonstrated that the filter substrates with non-uniform distribution of porosity, in particular those with a thin layer of reduced pore size on top of the wall, may achieve improved filtration performance [14][15][16][17][18][19][20][21]. ...

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Particle accumulation model in 3D reconstructed wall of a catalytic filter validated with time-resolved X-ray tomography

... Studies have shown that the pre-filter media has a protective effect on the main-filter media, but its effect is affected by the application environment and the matching between the pre-filter and the main filter. When 25% of the oil-coated particles are loaded, the addition of G4 pre-filter media actually shortens the service lifetime of the E11 PTFE main filter and the F9 melt-blown main filter [24]. Improper matching may not prolong the service lifetime of the main-filter media, and even in some cases, the pre-filter may change the particle size distribution, increase the proportion of fine particles, and shorten the service lifetime of the main-filter media instead [25]. ...

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The Effect of Pre-Filter and Main-Filter Media Matching on the Performance of an Ultra-High-Efficiency Two-Stage Filtration System

... Field measurement of PM 2.5 and its composition was carried out on the rooftop of the Institute of Environmental Engineering building, National Yang Ming Chiao Tung University (NYCU) in Hsinchu City. The sampling site was situated about 1 km away from heavy traffic road emission and industrial emission such as Hsinchu Science Park, where SVIMs was found to be dominant in PM 2.5 (Le et al. 2023). PM 2.5 was sampled using three different samplers: chilled Teflon filter sampler (CTF), PDS, and single Teflon filter (STF), which were operated simultaneously with the assistance of a Multifilter PM 10 -PM 2.5 Sampler (MFPPS, Figure 1a) (Liu, Chen, and Tsai 2011). ...

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Optimization of sampling conditions to minimize sampling errors of both PM 2.5 mass and its semi-volatile inorganic ion concentrations

... relates to the size of the incoming soot. The total filter size-resolved efficiency E k,t and total filter overall efficiency E t are calculated based on the entire upstream and downstream wall substrates [36,37]. E k,t has no dependence on the numberor mass-based calculations, but the overall efficiency E t should be specified whether it is in mass E M,t or in number E N,t . ...

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A Dual-Geometry Pore-Size-Resolved Model to Predict Deep-Bed Loading in a Wall-Flow Filter