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The main technical challenges for the treatment of volatile organic compounds (VOCs) with plasma-assisted catalysis in industrial applications are large volume plasma generation under atmospheric pressure, byproduct control, and aerosol collection. To solve these problems, a back corona discharge (BCD) configuration has been designed to evenly generate nonthermal plasma in a honeycomb catalyst. Voltage-current curves, discharge images, and emission spectra have been used to characterize the plasma. Grade particle collection results and flow field visualization in the discharge zones show not only that the particles can be collected efficiently, but also that the pressure drop of the catalyst layer is relatively low. A three-stage plasma-assisted catalysis system, comprising a dielectric barrier discharge (DBD) stage, BCD stage, and catalyst stage, was built to evaluate toluene treatment performance by BCD. The ozone analysis results indicate that BCD enhances the ozone decomposition by collecting aerosols and protecting the Ag-Mn-O catalyst downstream from aerosol contamination. The GC and FTIR results show that BCD contributes to toluene removal, especially when the specific energy input is low, and the total removal efficiency reaches almost 100%. Furthermore, this removal results in the emission of fewer byproducts.

Data Hiding in Encrypted Domain Based on Encryption Process''. Through excavation and effective use of redundancy in the encryption process, we compromise the information hiding technology and encryption technology, construct the theoretical model of the fusion of cryptography and information hiding technology, and design secure and efficient reversible information hiding methods. ABSTRACT NTRU (Number Theory Research Unit) has the characteristics of resistance to quantum computing attacks, fast encryption and decryption, and high security. It is very suitable for wireless confidential data networks and authentication systems. Combined with reversible data hiding technology, a separable reversible data hiding scheme in homomorphic encrypted domain based on NTRU is proposed. The image owner directly divides the cover-image into groups of a reference pixel and T adjacent pixels. Then, the grouped image is encrypted by NTRU. Finally, the encrypted image is uploaded to the data hider. The encrypted image is divided into groups by the same grouping method as the image owner. After that, the data hider calculates T absolute differences of adjacent pixels in each group to obtain histogram of the absolute differences. The additional data can be embedded into the encrypted image by shifting histogram of the absolute differences. After receiving the encrypted image with hidden data, the receiver can either use the data hiding key to directly extract the additional data from encrypted domain to obtain the encrypted image, or use the private key and data hiding key to extract the additional data from plaintext domain to get the cover-image. Experimental results show that our scheme has higher security and better embedding performance comparing with other state-of-the-art works. INDEX TERMS Reversible data hiding, encrypted domain, public key cryptosystem, homomorphic property, number theory research unit (NTRU).

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An intense luminescence flash can be induced during the collapse phase of bubbles generated by pulsed discharge in water. To gain insight into this special phenomenon, we experimentally investigated the optical characteristics and luminescence temperature inside collapsing bubbles. The duration of the luminescence flash generated by pulsed discharge was around tens of microseconds, which was confirmed by high-speed recording and the photodiode output, and the inception time of the luminescence flash was approximately 32.5 μs before the bubble collapsed to its minimum size. The temperatures of the luminescence flash at discharge energies of 25 and 30 J/pulse calculated according to the two-line radiance ratio method were 6673 and 6728 K, respectively.