Browsing by Author "Liu, Jian"

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    Endotoxin emissions from commercial composting activities
    (BioMed Central, 2009-12-21T00:00:00Z) Deacon, Lewis J.; Pankhurst, Louise J.; Liu, Jian; Drew, Gillian H.; Hayes, Enda T.; Jackson, Simon; Longhurst, James; Longhurst, Philip J.; Pollard, Simon J. T.; Tyrrel, Sean F.
    This paper describes an exploratory study of endotoxin emissions and dispersal from a commercial composting facility. Replicated samples of air were taken by filtration at different locations around the facility on 10 occasions. Measurements were made of endotoxin and associated culturable microorganisms. The inflammatory response of cell cultures exposed to extracts from the filters was measured. Endotoxin was detected in elevated concentrations close to composting activities. A secondary peak, of lesser magnitude than the peak at source was detected at 100-150 m downwind of the site boundary. Unexpectedly high concentrations of endotoxin were measured at the most distant downwind sampling point. Extracted endotoxin was found to stimulate human monocytes and a human lung epithelial cell line to produce significant amounts of pro- inflammatory cytokines. On a weight basis, endotoxin extracted from the composting source has a greater inflammatory cytokine inducing effect than commercial E. coli endotoxin.
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    In-situ tuning of catalytic activity by thermoelectric effect for ethylene oxidation
    (American Chemical Society, 2018-09-20) Achour, Abdenour; Liu, Jian; Peng, Ping; Shaw, Christopher; Huang, Zhaorong
    Thermoelectric material BiCuSeO used as a support and promoter for catalytic ethylene oxidation is reported here. The catalytic activity on the continuous and non-continuous catalyst Pt supported on BiCuSeO was observed to be promoted in-situ by a thermoelectric Seebeck voltage generated by the temperature gradient across the material. It is also shown this thermoelectric promotion of catalysis enabled the thermoelectric material BiCuSeO itself to be highly catalytic active for ethylene oxidation. A good linear relationship between the logarithm of the reaction rate and the thermoelectric Seebeck voltage was observed. This thermoelectric promotion of catalysis is attributed to the change of work function of the catalyst surface, accompanied by a charge transfer from the bulk to the surface due to the thermoelectric effect.
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    Optimization of multi-tooth milling tool for interlaminar damage suppression in the milling of carbon fiber–reinforced polymers
    (Springer, 2022-05-27) Liu, Jian; Tang, Xinkai; Li, Shipeng; Qin, Xuda; Li, Hao; Wu, Weizhou; Srijana, Yadav; Liu, Wentao; Liu, Haibao
    Carbon fiber–reinforced polymers (CFRP) are widely utilized in the aerospace field due to their significant specific strength, specific modulus, and strong design ability. However, anisotropy and low interlaminar bonding strength lead to burr, tear, lamination, and other damages in CFRP machining. In this paper, a 3D finite element model for the milling of CFRP was carefully developed, and the cutting forces, the interlaminar stress, and the interlaminar damage were properly obtained. Typically based on the developed model, the effects of geometric parameters of the multi-tooth milling tool were precisely analyzed. Next tool geometries were optimized for suppressing the interlaminar damage in the milling of CFRP. Results convincingly show that the multi-tooth milling tool with the geometry of 1.4 mm length of the micro tooth, 38.2° left helix angle, 11 left-handed chip grooves, 15° right helix angle, 12 right-handed helix grooves, approximately rectangular of section shape of the chip groove, 10° rake angle, and 15° clearance angle efficiently delivers the optimal performance. Besides, cutting performance of numerous coated tools was also studied. Results typically show that the multi-tooth milling tool with a diamond coating maintains significant advantages in aspects of the tool life and costs compared with the uncoated and diamond-like carbon coating (DLC)-coated tools.