Advanced Materials Research Vol. 830

Abstract: Effects of ultrasonic parameters (ultrasonic time, temperature and ultrasonic power) under different ultrasonic frequencies including 20, 60, 100 kHz on total phenolic contents (TPC) of extracts from citrus peel (CP) were analyzed. The results showed that TPC of extracts from CP increased significantly with increases of ultrasonic time, temperature and ultrasonic power under three ultrasonic frequencies.

Abstract: In this paper, the simulation of the piercing process is performed by the three-dimensional finite-element method in Dieschers mill. The material properties of steel 33Mn2V are introduced. The simulated results visualize dynamic evolution of temperature, especially inside the workpiece. Its show the distribution of temperature on the internal and external surface of the work-piece is non-uniform. The temperature of the internal surface is far higher than that of the external surface of workpiece.

Abstract: Removed at authors request

Abstract: To ensure safe and stable dragging operations of engineering equipments under the complex sea conditions as well as realizing the quick response and precise control of constant tension winch, the design of the hydraulic control system for constant tension winch regards constant tension winch as research objects coupled with a combination of PDF control (pseudo differential control) algorithm. By establishing the PDF mathematical model of hydraulic control scheme, calculateing the appropriate PDF controller parameters and using sumlink simulation analysis. It is safe to draw a conclusion that the PDF based control algorithm of constant tension control system bears a good dynamic response characteristics and robustness to meet control requirements of constant tension winch in operation under complex sea conditions, in order to provide a reference for further research and development of the constant tension control technology.

Abstract: Papain was first used as the catalyst for the synthesis of 5-benzylidene rhodanine derivative through the condensation reaction of 4-nitrobenzaldehyde and rhodanine. The result showed that the yield could be up to 86% by optimizing the reaction conditions.

Abstract: Pyrrolo [1,2-a] pyrazine possessed widely bioactivities due to its particular structure. In this work, three pyrrolo [1,2-a] pyrazines derivatives were synthesized from the 2-bromo-5-methoxypyrazine and propargyl amines or ethers through the Pd-catalyzed intermolecular cycloisomerization strategy. Their structures were characterized by NMR, IR, EI-MS and elemental analysis, and all of them exhibited moderate in vitro anti-inflammatory effects with the inhibitions of 43-59% against IL-6 at 50 μM. The compound 3c revealed relatively good anti-inflammatory activities. The bioactive pyrrolo [1,2-a] pyrazines might be potentially used as anti-inflammatory agents.

Abstract: Lipase from Candida rugosa (CRL) was used to catalyze the transesterification of vinyl acetate with 2-hydroxymethyl-1,4-benzodioxan in ionic liquid microemulsions (H₂O/[BmiPF₆, water in 1-butyl-3-methylimidazolium hexafluorophosphate), and the results demonstrated that CRL could preserve higher catalytic activity in H₂O/[BmiPF₆ microemulsions.

Abstract: Butanol is considered as a potential fuel due to several advantage over ethanol. However, it is still of urgent demand to identify better feedstock, which is more renewable and cost-effective, for the production of bio-butanol. Microalgae can mitigate CO₂ emission and convert CO₂ into biomass abundant in carbohydrates, and thus appear as emerging third-generation feedstock for fermentation. In this study, an isolated microalga Chlorella vulgaris was cultivated photoautotrophically and the biomass was then harvested for the use in butanol fermentation with a Clostridium acetobutylicum strain via acetone-butanol-ethanol (ABE) fermentation. The results show that 3.37 g L^-1 of butanol was produced from 111g of acid-pretreated biomass of C. vulgaris. This demonstrates the potential of using microalgal feedstock for fermentative butanol production. The results also suggest that to improve hydrolysis efficiency of C. vulgaris, higher concentration of sulfuric acid (>2%) should be used.

Abstract: Gallnut products are widely used in pharmaceutical, chemical, food, printing, aerospace, national defense and microelectronics industries due to their irreplaceable superiorities. In this paper, membrane separation technology was used to concentrate the tannin in the gall extract. Separation efficiency was investigated by different NF and RO membrane model, and the optimized purity of extracted tannin was 98% with yield of 97.5% that achieve the industrial tannin standards. Moreover, the flux capacity of membrane can be restored by corresponding cleaning solution.

Abstract: Double-perovskites Y_1-xCa_xBaCo₂O_5+δ (YCBC,x = 0.1-0.5) were synthesized with a auto ignition process and were assessed as cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCx) based on Sm_0.2Ce_0.8O_1.9 (SDC) electrolyte. X-ray diffraction confirms that there are some undesired peaks in YCBC0.1 and YCBC0.5, while the YCBC (x = 0.2-0.4) retains single phase with tetragonal structure. The YCBC materials exhibit chemical compatibility with SDC electrolyte up to a temperature of 1100°C. The conductivity of the samples decreases with increasing Ca content, and the maximum conductivity of YCBC is 506 Scm^-1 for x = 0.2 sample. The increased doping of Ca deteriorates the area-specific resistances of YCBC (x = 0.2-0.4) cathodes. The Rp values of YCBC cathodes at x = 0.2,0.3 and 0.4 on the SDC electrolyte are 0.26, 0.53 and 1.19Ωcm² at 650°C, respectively. This study suggests that YCBC0.2 can be potential candidates for utilization as IT-SOFCs cathode.