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Cryptocaryon irritans causes one of the most serious diseases in various wild and cultured marine fish, leading to mass mortality and economic loss. In this study, hydroxyl radical (•OH) solution produced by strong ionization discharge combined with water jet cavitation effect was injected into orange‐spotted grouper (Epinephelus coioides) aquaculture tanks for C. irritans control. The results showed that all C. irritans theronts were inactivated by •OH solution at concentrations of 0.5 mg/L within 2 min. •OH could induce alteration of shape, the absence of motility and macronucleus dispersion in theronts. A possible explanation was that the macronucleus of C. irritans might be damaged by •OH; as a result, its metabolism and life activities were disturbed. The •OH treatment increased the survival rate of E. coioides challenged with C. irritans from 64.7 ± 8.0% (mean ± SD) to 100% and reduced their infection intensity significantly. Stress response biomarkers such as malonaldehyde, glutathione, glutathione peroxidase, superoxide dismutase (SOD) and catalase levels in the gills of E. coioides at different time points were analysed. The SOD activity in the •OH group first decreased and then recovered to the initial level at the end of the experiment. The other stress response biomarkers had no significant difference from that in the uninfected control group after •OH treatment. Additionally, the gill of E. coioides in the •OH group exhibited slight and reversible transformation compared with the uninfected control group. Compared with •OH treatment, chlorine dioxide and formalin treatment reduced the survival rate, induced oxidative damage and changed the histological gill structure in E. coioides. In conclusion, •OH could be applied effectively to control C. irritans infection without affecting the normal physiological condition of E. coioides. [ABSTRACT FROM AUTHOR]

ABSTRACT The conversion of methane to liquid products, hydrogen ([H.sub.2]), and ammonia ([NH.sub.3]) was investigated experimentally using microgap discharge plasma at an environmentally friendly condition. The experimental results indicated that [...]

A pilot-scale experiment for killing red tide organisms in a sea enclosure was done in Bohai Sea off Dalian City, China, in August 2003. With the physical method of micro-gap gas discharge, an OH* solution of 24.3 mg/L was produced by the ionization of [O.sub.2] in air and [H.sub.2]O at gas state and then dissolved into one part of seawater. When the OH* concentration was 0.68 mg/L in the sea enclosure, the total kill efficiencies of 26 kinds of red tide organisms reached 99.8%, in which the bacterium and vibrio were reduced below the detection limit, meanwhile Gonyaulax cysts and Prei. Cysts with the cell crust were decreased to under the test limit. In addition, the content of chlorophyll-[alpha] was decreased below the test limit. The dissolved oxygen saturation of seawater was greatly increased to 430%. Therefore, the treatment of red tide using OH* radicals is a kind of advanced oxidation technology, which realizes zero pollution, zero emission, and zero residual. Index Terms--Kill efficiency, micro-gap discharge, OH* radicals, red tide organisms.

ABSTRACT The removal of sulfur dioxide (S[O.sub.2]) from simulated flue gases streams ([N.sub.2]/[O.sub.2]/[H.sub.2]O/S[O.sub.2]) was experimentally investigated using microgap discharge. In the experiment, the thinner dielectric layers of aluminum oxide ([Al.sub.2][O.sub.3]) [...]

The plasma synthesis of ammonia has been studied in nitrogen-hydrogen plasma using a microgap dielectric barrier discharge at ambient pressure. With the new technology of dielectric layers, the high-energy electrons are obtained in a narrow discharge gap; meanwhile, [N.sub.2] and [H.sub.2] molecules are ionized and dissociated and a large number of free atoms, ions, and radicals are formed in a nonequilibrium plasma after inelastic collisions. The final product was mainly ammonia, and the yield of ammonia reaches 12500 ppm (1.25%). In this way, plasma synthesis of ammonia at ambient pressure is realized and a new method is provided for inorganic synthesis. Index Terms--Ambient pressure, concentration of ammonia, dielectric barrier discharge (DBD), synthesis of ammonia.

We demonstrated that the feats of the dolphin biosonar system can be achieved through physical implementation. Numerical and experimental results suggested that dolphins have evolved to intelligently manipulate physical laws. Gradient distributions of sound speed and density in the forehead counterpart can enhance the main beam by gathering more sound energy to reinforce the main beam and lowering side lobes. As dolphins prove to accomplish efficient control on their biosonar capabilities in multiple ways, this paper provides an additional aspect to enrich our understanding of how one of the best natural biosonar systems works and build a step to inspire additional advanced sound control systems. [ABSTRACT FROM AUTHOR]