Capture efficiency of torrent ducks by the active mist-net method

Particle deposition could decrease the aerodynamic performance and cooling efficiency of turbine vanes and blades. The particle motion in the flow and its temperature are two important factors affecting its deposition. The size of the particle influences both its motion and temperature. In this study, the motion of particles with the sizes from 1 to 20 μm in the first stage of a turbine are firstly numerically simulated with the steady method, then the particle deposition on the vanes and blades are numerically simulated with the unsteady method based on the critical viscosity model. It is discovered that the particle deposition on vanes mainly formed near the leading and trailing edge on the pressure surface, and the deposition area expands slowly to the whole pressure surface with the particle size increasing. For the particle deposition on blades, the deposition area moves from the entire pressure surface toward the tip with the particle size increasing due to the effect of rotation. For vanes, the particle capture efficiency increases with the particle size increasing since Stokes number and temperature of the particle both increase with its size. For blades, the particle capture efficiency increases firstly and then decreases with the particle size increasing.

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Tannic acid-functionalized HEPA filter materials for influenza virus capture

Scientific Reports ◽

10.1038/s41598-020-78929-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Subin Kim ◽

Jinhyo Chung ◽

Sang Hyun Lee ◽

Jeong Hyeon Yoon ◽

Dae-Hyuk Kweon ◽

...

Keyword(s):

Influenza Virus ◽

Tannic Acid ◽

High Efficiency ◽

Influenza Viruses ◽

Capture Efficiency ◽

Protective Equipment ◽

Filter Materials ◽

Washing Process ◽

Pathogenic Viruses ◽

Cost Efficient

AbstractInfluenza, one of the most contagious and infectious diseases, is predominantly transmitted through aerosols, leading to the development of filter-based protective equipment. Though the currently available filters are effective at removing submicron-sized particulates, filter materials with enhanced virus-capture efficiency are still in demand. Coating or chemically modifying filters with molecules capable of binding influenza viruses has received attention as a promising approach for the production of virus-capturing filters. For this purpose, tannic acid (TA), a plant-derived polyphenol, is a promising molecule for filter functionalization because of its antiviral activities and ability to serve as a cost-efficient adhesive for various materials. This study demonstrates the facile preparation of TA-functionalized high-efficiency particulate air (HEPA) filter materials and their efficiency in influenza virus capture. Polypropylene HEPA filter fabrics were coated with TA via a dipping/washing process. The TA-functionalized HEPA filter (TA-HF) exhibits a high in-solution virus capture efficiency of up to 2,723 pfu/mm2 within 10 min, which is almost two orders of magnitude higher than that of non-functionalized filters. This result suggests that the TA-HF is a potent anti-influenza filter that can be used in protective equipment to prevent the spread of pathogenic viruses.

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Sparse damage detection via the elastic net method using modal data

Structural Health Monitoring ◽

10.1177/14759217211021938 ◽

2021 ◽

pp. 147592172110219

Author(s):

Rongrong Hou ◽

Xiaoyou Wang ◽

Yong Xia

Keyword(s):

Damage Detection ◽

Structural Damage ◽

Damage Identification ◽

Measurement Data ◽

Elastic Net ◽

Sensitivity Matrix ◽

Regularization Technique ◽

Modal Data ◽

Regularization Techniques ◽

Net Method

The l1 regularization technique has been developed for damage detection by utilizing the sparsity feature of structural damage. However, the sensitivity matrix in the damage identification exhibits a strong correlation structure, which does not suffice the independency criteria of the l1 regularization technique. This study employs the elastic net method to solve the problem by combining the l1 and l2 regularization techniques. Moreover, the proposed method enables the grouped structural damage being identified simultaneously, whereas the l1 regularization cannot. A numerical cantilever beam and an experimental three-story frame are utilized to demonstrate the effectiveness of the proposed method. The results showed that the proposed method is able to accurately locate and quantify the single and multiple damages, even when the number of measurement data is much less than the number of elements. In particular, the present elastic net technique can detect the grouped damaged elements accurately, whilst the l1 regularization method cannot.

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