Loss of Torque on Magnetic Fluid Seals with Rotating-shafts

Jianhui Hu,Meng Zhao,Lu Wang,Jibin Zou,Yong Li 한국자기학회 2017 Journal of Magnetics Vol.22 No.2

The effects of loss of torque on magnetic fluid seals with rotating-shafts and the general difficulty of studying magnetic fluid seals are the focus of this work. The mechanism underlying loss of torque on such seals is analyzed using theoretical methods that show that loss of torque can be affected by several factors, including the velocity of the rotating-shaft, the structure of the sealing device, the characteristics of the magnetic field, and the characteristics of the magnetic fluid. In this paper, a model of the loss of torque is established, and the results of finite element analysis and testing and simulations are analyzed. It is concluded that (ⅰ) the viscosity of the magnetic fluid increased with the intensity of the magnetic field within a certain range; (ⅱ) when the magnetic fluid was saturated, the increase in loss of torque tended to gradually slow down; and (ⅲ) although the axial active length of the magnetic fluid may decrease with increasing speed of the rotating-shaft, the loss of torque increased because of increasing friction.

The Influence of Dietary Calcium and Phosphorus Imbalance on Intestinal NaPi-IIb and Calbindin mRNA Expression and Tibia Parameters of Broilers

Li, Jianhui,Yuan, Jianmin,Guo, Yuming,Sun, Qiujuan,Hu, Xiaofei Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.4

A $2{\times}2$ factorial experiment was conducted to study the effect of dietary calcium and non-phytate phosphorus (nPP) imbalance on calbindin and NaPi-IIb mRNA levels in the small intestine and tibia parameters of broiler chicks. One hundred and forty four 1-d-old Arbor Acres male broiler chicks were divided into four treatments consisted of six replicates with six chicks each. The two dietary calcium levels were 1.10% and 0.60%, and two dietary nPP levels were 0.50% and 0.27%. Results showed that a high Ca/nPP ratio diet (4.07:1) significantly depressed feed intake and weight gain of broilers (p<0.05), but a lower Ca:nPP ratio (1.2:1) had no influence (p>0.05). Low-Ca with low-P diet resulted in low tibia minerals and tibia breaking strength of broilers, and all the tibia parameters were further decreased when the dietary ratio of Ca to P was relative higher. Low dietary Ca or P up-regulated the calbindin and NaPi-IIb mRNA expression levels. Low Ca with normal P diet up-regulated duodenal calbindin mRNA expression level to the greatest extent. Low P with a normal Ca diet significantly enhanced NaPi-IIb mRNA expression level to the highest extent. These results suggest that the calbindin and NaPi-IIb mRNA expression were enhanced by the imbalance between dietary Ca and nPP, and their expression were not only influenced by Ca or nPP level, but also the ratio of Ca:nPP.

An Efficient Method for Multicomponent Synthesis of Spiro[4H-pyran-oxindole] Derivatives Catalyzed by Magnesium Perchlorate

Chunlei Wu,Runpu Shen,Jianhui Chen,Chunqi Hu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

A simple and efficient method for the synthesis of spiro[4H-pyran-oxindole] derivatives by means of threecomponent reactions between isatins, malononitrile or ethyl cyano-acetate, and 1,3-dicarbonyl compounds in the presence of catalytic amount of magnesium perchlorate in 50% aqueous ethanol medium has been described.

Study on Effects of Blending Fiber Type and Ratio on Antibacterial Properties of Chitosan Blended Yarns and Fabrics

Xiao Tian,Tszyin Poon,Yiyi Yang,Hong Hu,Jimin Fu,Jianhui Li,Ben Niu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.9

Chitosan fiber possesses inherent advantages, such as excellent biocompatibility, nontoxicity as well asantibacterial property. However, there is no systematic study on the chitosan fiber blending effect with other fibers, and onthat basis, there is no suitable fiber blending technology for yarn and fabric production, which results in the incorrectproportion of chitosan fiber blended with other fiber type and thus lowers the fabric functionality as well as increases thematerial cost. In this study, thirteen chitosan blended yarns were designed and developed. Blending yarn structure wasexamined and the effects of blending fiber type and ratio on the antibacterial and physical property were firstly investigated. The experimental results show that the inhibition rate rises with the increase of the chitosan blending ratio. The polyester/cotton/chitosan and tencel/chitosan yarns have a better inhibition rate of Staphylococcus than that of the cotton/chitosan yarn,indicating that the blending fiber type has an impact on antibacterial properties. Moreover, various chitosan blended knittedfabrics were produced by using the chitosan blended yarns developed and their antibacterial, physical properties and comfortas well as anti-mite activity were evaluated. The results illustrate that the knitted fabrics with a small amount of chitosanfibers exhibit excellent antibacterial properties and desirable comfort. Furthermore, the chitosan blended fabrics present theanti-mites effect. This work would contribute to lowering the material cost of functional yarns and promoting thedevelopment of antibacterial textiles.

An Efficient Method for Multicomponent Synthesis of Spiro[4H-pyran-oxindole] Derivatives Catalyzed by Magnesium Perchlorate

Wu, Chunlei,Shen, Runpu,Chen, Jianhui,Hu, Chunqi Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

A simple and efficient method for the synthesis of spiro[4H-pyran-oxindole] derivatives by means of three-component reactions between isatins, malononitrile or ethyl cyano-acetate, and 1,3-dicarbonyl compounds in the presence of catalytic amount of magnesium perchlorate in 50% aqueous ethanol medium has been described.

Tunable stability of oil-containing foam systems with different concentrations of SDS and hydrophobic silica nanoparticles

Shuangqing Sun,Yan Wang,Congtai Yuan,Hongbing Wang,Wendong Wang,Jianhui Luo,Chunling Li,Songqing Hu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.82 No.-

Experiment and molecular dynamics simulation were carried out to study the tunable stability of oilcontainingSDS-stabilized Nitrogen-in-water foam. The experimental results show that the foam stabilitycould be tuned by the concentrations of SDS and modified SiO2 nanoparticles. In the foam systems with alow SDS concentration (0.2 wt.%), the foams show poor stability and the foam stability was almost notaffected by the addition of modified SiO2 nanoparticles. The foam stability was greatly improved atmoderate SDS concentration (0.5 wt.%), it enhancedfirst and then weakened with the increase ofmodified SiO2 concentration, and the half-life time achieved a maximum value of 1292 s at 0.05 wt.%modified SiO2. However, at high SDS concentration (0.8 wt.%), the foam stability was pretty good exceptfor when the modified SiO2 concentration is too high (>0.2 wt.%). The microscopic mechanism wasobtained by investigating the structural and dynamic properties of the foamfilm. The simulation workshowed consistent results of foam stability with the experimental results. Moreover, it also revealed thatthe concentration and configuration of SDS will affect its interaction with SiO2 and oil molecule, which iscritical to foam stability.

The physicochemical, antioxidant, hypoglycemic and prebiotic properties of γ-irradiated polysaccharides extracted from Lentinula edodes

Chaomin Yin,Chen Li,Kun Ma,Xiuzhi Fan,Fen Yao,Defang Shi,Wenjing Wu,Jianhui Qiu,Guoyuan Hu,Hong Gao 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.7

In this study, the influence of γ-irradiation with different dose (0, 4, 8, and 16 kGy) on chemical composition, physicochemical features and bioactivities of polysaccharides extracted from Lentinula edodes (LEP) were investigated. The carbohydrate content (from 59.47 to 70.96%), the solubility, the ⋅OH and DPPH scavenging ability of LEP increased with the increased γ-irradiation dose, while the protein content, the weight-average and number-average molecular weight of LEP were significantly decreased with the increased γ-irradiation dose. Moreover, γ-irradiation treatment caused LEP color changes and surface topography destroyed. γ-Irradiated LEP showed higher hypoglycemic activities in vitro than that of non-irradiated LEP. Moreover, γ-irradiated LEP had better proliferation promoting effects on Lactobacillus rhamnosus and L. plantarum. These results showed that γ-irradiation treatment changes the physicochemical features of LEP, thus affects its antioxidant, hypoglycemic and prebiotic properties, which suggests that γ-irradiated LEP has potential application in the pharmaceutical industries and functional foods.