Advanced Materials Research Vols. 634-638

Abstract: The p-toluene sulphonic acid (PTSA)/MCM-41 was prepared by impregnation method with self-synthesized MCM-41. The investigation of effects on PTSA solution concentration was investigated and the catalyst prepared with 0.1mol/L PTSA performed best. Oleic acid was chosen as a simulation of high-acid-value oil to esterify with methanol. The experimental results showed that PTSA/MCM-41 was a high active catalyst in esterification. The optimal condition was as following: the reaction temperature was 80°C, the methanol/oleic acid molar ratio was 5:1, the catalyst amount was 5% (wt. /wt.) of the oleic acid, and reaction time was 1h. Under this condition, the oleic acid conversion could reach 94.3%. The stability of the catalyst was very well for the oleic acid conversion can still maintain 92.8% after used four times.

Abstract: The lignocellulose is a widespread renewable resource. With the decrease of the petrochemical resources, lignocellulose is very important as an alternative resource to produce fuel ethanol. As for the conversion of cellulose into fuel ethanol, the saccharification of cellulose is a key process. The environment benign process using ionic liquid-water mixtures is studied to mild hydrolysis of cellulose to glucose without acid as catalyst. Ionic liquid of 1-allyl-3-methylimidazolium chloride ([Amim]Cl) is chosen to mix with water because it has great solubility of cellulose. The mass ratio of water with ionic liquid, reaction temperature and reaction time are studied and the optimal conditions of glucose yield are obtained as follows: the mass ratio of water 0.375, the reaction temperature 433 K and the reaction time 4h, and the yield of glucose is 77.08%.

Abstract: Rice husk is a plentiful agricultural byproduct. In this paper, rice husk (RH) surface was first treated by NaOH/urea into a modified-rice husk(MRH), then the MRH was used as a new template for polymerization of acrylamide(AM) on MRH, as a result, the product named as MRH-g-AM, was formed by the free-radical initiation in aqueous solution using ammonium persulfate as an initiator. The polymer grafted on the MRH was considered as a novel copolymer which was thereafter analyzed by FTIR and SEM. The product was washed thoroughly with distilled water to remove all unreactive chemicals. The results showed that MRH was successfully reacted with AM. The SEM images indicated that MRH-g-AM appeared distinct cracks and formed a loosen structure in comparison with RH, indicating the facilitation of heavy metal ion adsorption in the future wastewater treatment.

Abstract: A new damage-adaptive bone remodeling model, in which an algorithm incorporating both strain and damage stimuli, is developed in this paper. Typically, a human proximal femur model is established to predict the bone mass distribution during bone remodeling process. And human physiology damage-repair cycle is considered in the model. The governing equations of the mathematical model, digesting the predecessors’ ideas, are numerically solved and implemented into ANSYS software via the user interface of finite element algorithm. With the aid of this novel model, the whole healing behavior of human proximal femur is elucidated properly.

Abstract: Interest in glycerol dehydratase (GDHt) has increased beyond academic circles in the past few decades because of its role in the fermentation pathway for producing industrial 1,3- propanediol (1,3-PD). This paper introduces the research progress of GDHt with special emphases on its property and structure, gene cloning, mechanism of inactivation and reactivation as well as irrational design and rational design

Abstract: The synthesis of α-pinene oxide mediated by Novozym 435 (lipase from Candida antarctica) in a three-phase system was studied in this work. Novozyme 435 catalysed the formation of peroxyoctanoic acid directly from octanoic acid and hydrogen peroxide, which was then applied for in situ oxidation of α-pinene. The highest conversion of a-pinene (approximately 80%) was obtained when the reaction was performed at 30°C and initial hydrogen peroxide concentration in the water phase was set to be 30%. The parameters affecting the lipase activity were also investigated，where the peracid generated in organic phase was obvserved to greatly inactivate the enzyme compared to other components in the organic phase.

Abstract: The chemical composition of the ethyl acetate and n-butanol extracts of Dolomiaea wardii has been reported for the first time in the present study and eight compounds were isolated and identified as corymbolone(1), encelin(2), 8-oxoargentone(3), betulinic acid(4), lupeol(5), 4-hydroxyacetophenone(6), sweroside(7), Laganoside(8). anti-acetylcholinesterase activity of 1-8 showed that compound 6 have weak inhibitory activity with IC50 value of 1.43 mM.

Abstract: Nine compounds were isolated from the petroleum ether extract of Euphorbia altotibetica. The structures of these compounds were elucidated as: squalene (1), β-sitosterol acetate (2), 11, 15, 19, 23-tetramethy-5, 9, 17-tetracosatrienoic acid (3), physcion (4), (z)-10-nonadecenoic acid (5), (z)-4-undecenoic acid (6), β-sitosterol (7), (24S)-stigmastan-4-en-3-one (8), naringenin (9). These compounds were identified on the basis of comparing their NMR datas with those of corresponding compounds in the literature.

Abstract: Through chemical composition analysis, scanning electron microscope observation, stain-fungi isolation from stained canes and their inoculation on unstained canes, as well as xenon light aging study, causes of Daemonorops margaritae cane’s discoloration were investigated. Results show that the yellow discoloration is mainly chemical photo-induced and the blue, brown and red stains are mainly resulted from the stain-fungi’s mycelia colors or secreted pigments. A treatment with hydrogen peroxide solution as main bleaching agent was explored. All the above discoloration could be effectively removed and renewed to be attractive lustrous yellowish.

Abstract: Magnetic Fe3O4/cellulose microspheres with mean diameter of 100 μm were prepared by sol-gel transition method using ionic liquids (AmimCl) as solvent for cellulose dissolution and regeneration. Their structure , properties and morphology were analysed using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer. The results indicated that the synthesized microspheres were good sphere with a mean diameter of about 100 μm. It also showed that cellulose had been successfully covered onto the surface of Fe3O4 after the preparation. Therefore, we have provided a simple and biocompatible support for applications in the biomaterials field.