Advanced Materials Research Vols. 396-398

Abstract: Traditionally, calcium aluminate cement is always used as the binding agent for refractory castable applied in steel and iron, but cement contains many impurities, it is easy to generate low-melting additives and excessive liquid phase may be formed in material calcination, so the thermal shock resistance and moderate temperature intensity of corundum castables bonded with cement is worse; in addition, the flowability of cement-bonded castables also is poorer and it is difficult to construction. In the recent years, China and other countries have started to study properties of colloidal sol bonded castables to improve physical/chemical properties and workability of cement castables. This paper summarizes some characteristics of silica sol bonded materials via test and analysis.

Abstract: Ultrasonic technology was applied to polysaccharides extraction from Ottelia acuminata (Gagnep.) Dandy and Response Surface Methodology (RSM) was used to optimize the effects of processing parameters on polysaccharides yields. Three independent variables such as liquid-solid ratio (ml/g, X1), extraction temperature (°C, X2) and extraction time (hour, X3) were investigated respectively. The statistical analysis indicated that the three variables and the quadratic of X1 and X3 had significant effects on the yields and followed by the significant interaction effects between the variables of X1 and X3, X2 and X3 (p<0.05). A mathematical model with high determination coefficient was gained. The optimal extraction conditions of polysaccharides were determined as follows: liquid-solid ratio 43 ml/g, extraction temperature 90 °C and extraction time 3.45 hours. Under these conditions, the experimental yield of polysaccharides was 107.44 mg/g, which was agreed closely with the predicted value 108.71 mg/g.

Abstract: Residence time distributions were determined for the continuous processing of cut tobacco in the rotary drum by introducing expanded cut tobacco tracers to the inlet of the processing system using the negative step change method. Effects of rotating speed of the rotary cylinder and solids flow rate on the mixing homogenization and residence time distribution (RTD) of experiment materials was investigated. PER-CSTR series model and multistage CSTR model were used to fit the experimental results. The result shows mixing homogenization increased significantly with the increasing feeding rate of cut tobacco and decreasing drum rotating speed. PER-CSTR series model is more suitable to describe the RTD characteristics of flow materials in drum. The axis movement of cut tobacco along the drum is approximate to the plug-flow.

Abstract: A facile method was developed for preparation of fluorescence resonance energy transfer between CdTe QDs (donor) and rhodamine B (acceptor) in gelatin nanoparticles. The fluorescent gelatin nanoparticles embedded CdTe QDs and rhodamine B were prepared by a two-step desolvation way and characterized by UV–Vis spectrometer, spectrofluorometer, transmission electron microscope and fluorescent microscope. The prepared method allowed for short acceptor-donor separation and thus for high energy transfer efficiencies. Energy transfer efficiency (E) and distance (r) between CdTe QDs and rhodamine B were obtained to be 26.5% and 6.84 nm, respectively. The fluorescence resonance energy transfer system was proved to be formed successfully, indicating that the fluorescent gelatin nanoparticles were expected to be promising candidates for biological imaging studies.

Abstract: In this paper, magnetic composite photocatalysts were prepared through depositing TiO₂ on the surface of NiFe₂O₄ by sol-gel method. The composition, structure and magnetism of the samples are tested by XRD, TEM and VSM, respectively. The photoactivity of the as-prepared photocatalysts was investigated by degrading methyl orange under UV light. The effect of NiFe₂O₄ and SiO₂ intermediate layer on the activity of photocatalyst was also studied. It has been found that NiFe₂O₄ has a negative influence on the photocatalytic activity of magnetic TiO₂ compounds. The middle layer of SiO₂ can effectively improve the photocatalytic activity of magnetic TiO₂ compounds.

Abstract: New typical cross-flow Rotating Packed Bed (RPB) called multi-pulverizing RPB was manufactured. Mass and heat transfer property of the new type PRB were studied by two experimental models. In the mass transfer model, the axial fan pumping gas press is only 100 Pa, mass transfer coefficient is similar to countercurrent RPB. In the heat transfer experiment, the axial fan pumping gas press is only 120 Pa; volumetric heat transfer coefficient is from 75 kW.m^-3. K^-1 to 100 kW.m^-3. K^-1.

Abstract: The transport characteristics of cut tobacco as a typical biological wet slender particle were investigated in a pilot-scale rotary cylinder. Effect of solids and gas flow rate, moisture content of particles and rotating speed of cylinder was analyzed. The adaptability of the classical Friedman model for predicting average residence time of these type particles was also investigated. The result shows that the gas flow rate, moisture content of particles as well as rotating speed of cylinder have a significant influence on the axis transport velocity and forward step per cycle of cut tobacco in rotary cylinder. It’s difficult for Friedman model to accurately describe influence of gas flow rate and moisture content on transport of cut tobacco, which was associated with the particle characterize and influence of moisture content on the fluidity of particles.

Abstract: Fluidization behavior of binary mixtures with titanic slag particles and carbon particles had been investigated. Three solids states in the bed: fixed bed, transient fluidization and steady fluidization, emerges as increasing gas velocity. The extent of segregation of solids mixture in transient fluidization regime depended on the size difference between jetsam particles and flotsam particles. The effects of flotsam particle size, initial jetsam concentration and the superficial gas velocity on the segregation of binary solids had been measured.

Abstract: The paper treats of the low cycle fatigue (LCF) behaviour of GX12CrMoVNbN9-1 (GP91) cast steel after heat treatment. Fatigue tests at the temperature of 600oC within the scope of small amount of cycles to failure were carried out for five levels of controlled amplitude of total strain εac = 0.25, 0.30, 0.35, 0.50 and 0.60 %. The investigated cast steel within the scope of low cycle fatigue life reveals a three-stage course of changes in strength and strain. In the given scope of low cycle fatigue for GP91 cast steel, cyclic weakening was observed without the occurrence of stabilization period of its properties.

Abstract: Biocompatible MgAl-CO3-LDH-derived layered double oxide (LDO) as the host and bovine serum albumin (BSA) as a model protein have been chosen to fabricate a novel bioinorganic nanohybrid (BSA-LDO). The structure, morphology and physicochemical properties of the obtained nanohybrids are investigated by XRD, FT-IR, SEM and UV-vis methods and the interaction between LDO and BSA molecules has been discussed. The application of these nanohybrids as drug carrier is primarily studied by examining the adsorption behaviors of three drugs.