Advanced Materials Research Vols. 233-235

Abstract: PTFE suspension latex and PVA solution are blended at different ratio, and the rotary rheometer is used to test the rheological properties of these solutions. The result shows that both PTFE suspension latex and PTFE/PVA blended solution are all shear thinning fluid; with increasing shear rate, apparent viscosity decreases; with increase of PVA content in blended solution, apparent viscosity and Non-Newtonian index increase, and spinnability of blended solution can be improved; with increase of temperature, the apparent viscosity decreases.

Abstract: This paper presents an optimization technology for the molecular design of environmentally friendly solvents for extractive distillation. The approach based on the concept of group contribution methods (GCM). To decrease the complexity and random of design problem, a set of functional groups are pre-selected based on the modified UNIFAC method. Combination of groups can produce different molecule, once the molecule is generated, the properties are evaluated to determine if it satisfy the criteria. The criteria include separation performance and environmental performance. Simulated annealing algorithm is used to search feasible molecular structures. The molecule transition strategies and parameters of algorithm are described detailedly. Finally, the method is demonstrated with two examples, and the design results show that the proposed technology is a valid technology to design the desirable solvents.

Abstract: Anthocyanins was known for their antioxidant and pharmacological properties used by humans for therapeutic purposes. Here, we study the inhibitory effects of anthocyanins from Lonicera edulis on the proliferation of HT-29 colorectal adenocarcinoma cells and its possible mechanism in vivo by MTT. The different percentages of apoptotic cells present in flow cytometry analysis. The effect on HT29 cells was enhanced with increasing amount of anthocyanins. Typical morphological features of apoptosis were observed by transmission electron microscope. The mechanism of anthocyanins from Lonicera edulis on HT29 cell growth inhibition may be related to the induction of apoptosis.

Abstract: The heat transfer in granular materials can be found in many industry processes. But the phenomenon is not well understood. A particle contact heat transfer model (PCHM) was developed by taking each independent mechanism into account. The model combined with DEM was used to simulate heat transfer between particles and inserted heating surface. Comparing with each mechanism, the heat conduction through contact area has the most contribute to apparent effective quantity of heat transfer. The key factors effecting on Q_eff include: the number of particles contacting with heating surface, the contact time, and the contact area. When the average diameter is same, the diameter distribution has little effects on heat transfer. While the average diameter is different, the effective heat transfer coefficient decreases with the increasing of particle diameter. The quantity of heat transfer is spatially non-uniform.

Abstract: It is fracture, wear and abscission of bit tooth that make up of the main failure forms for the air hammer bit, which have badly restricted the further popularization and application of the air hammer drilling. The main reason is that the ordinary cemented carbide tooth is difficult to meet the complex conditions of the air the hammer drilling. Therefore, this research puts forward a new thought that we strengthen the carbide tooth by adding the nano-Al₂O₃ into the substrate materials of WC-Co. According to the study of several formulas of nano-composites, the test of sample performance, experimental study of impact abrasive wear and microstructure, we draw some conclusions that adding amount of nano-Al₂O₃ can refine grain, make microstructure more uniform and improve the wear resistance of composites, but also can enhance the strength of boundaries of WC-Co and transform the fracture form from the intergranular fracture to the transgranular fracture. Meanwhile, it can also improve nano-composites comprehensive performance by adding rare earth. The result for site test of bit shows that comparing with the bit equipped the original carbide teeth, the efficiency of rock breaking of the bit equipped nano-composites teeth increase by 20% and the service life increase by 80%.

Abstract: Pineapple peel as main material was fermented with Phaffia rhodozyma to produce astaxanthin. Using the Box-Behnken design, the effects of sugar content, initial pH and nitrogen content were studied with the yield of astaxanthin as response value, which was evaluated to optimize the fermentation conditions of astaxanthin production. The optimal fermentation conditions have been reached by the study: sugar content was 36.3 g/L, the initial pH was at 5.85 and nitrogen content was 8 g/L. By validation test, the astaxanthin yield under the optimal condition, which was basically corresponded to the model prediction, was 97.11 %.

Abstract: The porous SiO₂/TiO₂ bilayer antireflection coatings with self-cleaning capacity have been prepared by a sol-gel dip-coating method, the surfactant template, Pluronic F123 (PF123) was added to the sol as a pore generator. The performances of the coatings were analyzed with ultraviolet visible spectrophotometer (UV-Vis), scanning electron microscope (SEM) and atomic force microscopy (AFM). The self-cleaning function of coatings was evaluated by means of photocatalytic degradation of methyl orange in aqueous solution, and mechanical strength of the coatings has also been studied. The results indicate that the average transmittance of porous SiO₂/TiO₂ coating increases by 6% as compared to uncoated glass, the coating has a small particle size, a porous structure and a low roughness. After illuminated by ultraviolet light for 3 h, the 5 mg/L methyl orange can be degraded by 56.5%. In addition, the coating has an excellent mechanical strength.

Abstract: Distillation-crystallization coupling process is a new kind of separation technology based on vapor-liquid equilibrium and solid-liquid equilibrium. The separation of azeotropic systems composed with Acetic acid and N-neptane by distillation-crystallization process (DCC) was studied in this paper. We apply the orthogonal experiment to search for the optimal technique process. The final results demonstrate that the DCC process can purify the heavy and light components over 90 wt% respectively, verifying the advantage of the DCC for the azeotropic systems separation.

Abstract: In this paper, a new polymer process machine--- centrifugal extruder is introduced. The performance of centrifugal extruder has been studied by theoretical analysis and experiments. By the thermodynamic analyses, the mathematic model is founded including the radiation transfer and convection transfer. And the function described the temperature on the surface of the rotor is gotten. So, it is known that the rotation speed is the main influencing factor on the temperature of the surface. According to the experiments, it is known that the design of the experiment equipment can provide enough thermal energy for produce and the mathematic result is fit the experiments’ very well.

Abstract: The erosion wear experiments of low-chromium cast iron containing nickel were done by MCF-30 Erosion Abrasion Experimental Machine. The structure and surface morphology after erosive wear were analyzed by SEM and XRD. The results indicated that the distribution of carbide was reticular after tempering at 250and oil quenching at 960. The maximal erosion wear rate was appeared at 60 °erosion angle, high acid corrosion media have great influence on the abrasion resistance of experimental material and corrosion effects almost had no influence on the abrasion resistance of experimental material in the weak acid environment of pH≥3. The erosive wear mechanism of the experimental material was studied.