Advanced Materials Research Vols. 236-238

Abstract: Resolution of clenbuterol hydrochloride enantiomers and propranolol hydrochloride enantiomers was achieved by thin-layer chromatography using methyl-β-cyclodextrin impregnated silica gel GF254 plates. The effects of stereoselective auxiliary (acetonitrile/different alcohols) were studied. Resolution of clenbuterol hydrochloride enantiomers could be realized by alcohols such as ethanol, n-butanol, 2-butanol or tert-butanol together with acetonitrile, and propranolol hydrochloride enantiomers could only be resoluted by ethanol or n-butanol together with acetonitrile. The optical conditions of simultaneous resolution were obtained as follows: 15.00g silica gel GF254 plates impregnated with 1.00g methyl-β-cyclodextrin, acetonitrile/n-butanol (V/V = 90:10) mixed solvent as spreading solvent, being resolved under ambient temperature. Under these conditions, R_F value of resolution of clenbuterol hydrochloride enantiomers is 3.47, R_F value of resolution of propranolol hydrochloride enantiomers is 3.35. The two couples of enantiomers were all achieved base line separation.

Abstract: Jatropha curcas (Jc) was the most favored biomass plant for bio-diesel production. Jc cakes obtained after oil pressed, rich in protein content, were excellent materials for preparing formaldehyde-free wood adhesives, which could provide alternative to formaldehyde-based resins. Sodium hydroxide, used as denaturing agent, modified protein contained in Jc cakes to prepare wood adhesives. Jc adhesives prepared in different pH value and plywood bonded by them were prepared. The curing behavior of these adhesives was conducted by differential scanning calorimetry (DSC) measurement. The gel content and water absorption of the cured Jc adhesives were measured to evaluate their curing content and the water resistant of plywood bonded with these adhesives was also studied. The results showed that pH value influenced the bonding strength of adhesive significantly. The bonding strength of plywood made by modified Jc adhesive significantly increased comparing with that of unmodified one. The curing peak temperature decreased obviously after modified, which was beneficial to achieve complete curing reaction. Modified Jc adhesives provided a potential way to utilize by-product of energy plant, avoided formaldehyde pollution, and reduced dependence on fossil resources.

Abstract: The influences of desulfurization gypsum on the properties of both Magnesium oxychloride cement (MOC) pastes and MOC abrasive tools were investigated in this study. By incorporating desulfurization gypsum in the MOC pastes, the compressive strength of MOC paste improved slightly. With 5% gypsum addition, the flexural strength of MOC pastes increased by 36%, the abrasion loss of MOC abrasive tools decreased by 35%, the strength softening coefficient greatly increased. The mechanism maybe due to the microstructure of the MOC pastes became more compact with gypsum adding, the rate of hydrolyzation reaction of MOC phases would be postponed.

Abstract: Currently, in almost all stationery business, pastel, which is product with excellent performance and high value-added, is completely artificial packaged. Pastels have many colors (24, 36, 48, 54, etc.), and packaging workers are apt to confuse the colors of pastels which are loaded sequentially. To achieve rapid and orderly pastel packaging, it is necessarily to complete by automatic machinery. Unlike crayons, pastel is soft and easy to deformation, abrasion, adhesion. And six-prism pastel is easy to arching in hopper, leading to poor blanking. Therefore, present automatic packaging machine of crayon is unable to be used for pastel packaging. For the six prism Pastels automatic packaging machine, there are two problems to be solved: first, feed hopper and drop method, and second, the manner and control of orderly loading pastel into prop box. This study only considers the hopper, and blanking mode. The final hopper including bins, anti-bridging picks, kick wheel, blanking roller, etc. basically achieve controllable smooth six-prism pastel blanking.

Abstract: By varying the feed ratios of comonomers, butyl acrylate (BA), acrylic acid (AA), and methyl methacrylate (MMA), four acrylate macromolecular modifiers (AC730, AC532, AC235, and AC037) were synthesized by free radical copolymeration in ethnol. The effect of these modifiers on rheological behaviors of ultrafine CaCO₃ aqueous suspensions was investigated on the basis of a series of rheological measurements. The results showed that comonomer compositions and amounts of modifiers have obvious effect on rheological behaviors of CaCO₃ aqueous suspensions. In the case of AC730 and 0.2-0.4 parts of AC532, suspensions were pseudoplastic fluids, exhibiting shear thinning behavior; while in the case of AC235, AC037 and 0.6-1.4 parts of AC532, suspensions were dilatant fluids, exhibiting shear thickening behavior. Except the suspensions modified by 1.2 and 1.4 parts of AC730, the rheological data of other suspending systems could be well correlated with Herschel-Bulkley model. Optimum amounts of different modifiers were determined on the basis of rheological analysis, 0.8 parts for AC730, 0.6 parts for AC532 or AC235, and 0.4 parts for AC037.

Abstract: In order to study the relation between the design parameters and the oscillation characteristic of the static gas wave refrigerator, the oscillation characteristic influenced by the design parameters including inlet pressure, width of the nozzle and the spliter location is analysed by means of numerical study. The results show that (1)the higher the inlet pressure is, the bigger the fluidic momentum and curvature radius of the fluidic attachment are. The further the attachment location is, the higher the controlling pressure at the port of the interconnection line is, while the smaller the switching time of the fluidic is;(2)When the width of nozzle increases, the fluidic is more unstable and the switching time is shorter and attachment location is obviously further;(3)with the decrease of the spliter location, the time to oscillate becomes shorter and the switching pressure becomes smaller.

Abstract: Experimental investigation of falling film evaporation on horizontal tubes was carried out in this paper. Tube surface, spray flow rate and coolant flow rate were the factors considered in the experiment. The impact on falling film evaporation performance was obtained as expected. Experimental results are obtained that the heat transfer performances of low finned tubes are better than that of smooth tubes. The increasing of flow rate enhances heat transfer performance of falling film evaporation at first, while the flow rate gets a certain value, it will hinder the improvement of heat transfer performance. It was also found that there is almost no effects on heat transfer coefficient when the flow rate of coolant changes.

Abstract: In order to improve the stratification of clay materials in the spiral reamer, we use "bionics method" to modify the structure of the spiral reamer, namely, to add corrugated shape structure to the cutter and hub. Through the analysis of ANSYS software, it is found that corrugated fractal structure can both improve the stratification of clay materials, and increase the yield as well.

Abstract: Numerical simulation by CFD to analyze the mechanism of mud out of mud extrusion process of the velocity field in the simulation, the influence of the quality of the clay mud section the nature of materials were studied. Moisture content through the mud in two different relative speed and absolute speed of analysis, the mud at different water content in the de-airing pug spiral reamer change the speed of flow field.

Abstract: In order to transfer energy between two fluids directly and more efficiently, a novel pressure-exchange ejector was designed, and a multi-period numerical model considering leakage and gradual opening and closing of the ports was set up. The numerical model was validated by experiment and results proved that it could capture the shock wave accurately and predict the performance of pressure-exchange ejector effectively. The pressure waves in one working cycle and the flow field were displayed based on numerical simulation. Results shew that the energy was transfered by pressure waves and the vortexes generated during gradual opening and closing process led to a significant mixing between fluids and a distortion contact interface. Finally the effects of rotary speed and the gaps between ports and channels were investigated. With the increase of the inlet gap, the performance of the device reduced, while the outlet gap had a slight influence on performance. Besides, there was an optimal rotary speed for a fixed geometrical arrangement.