Advanced Materials Research Vol. 662

Abstract: The complex of β-cyclodextrin (β-CD) and RC2540 dialkyl pentasulfide was synthesized and characterised by means of fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TG) and scanning electron microscope (SEM). Then the friction and wear behavior of RC2540, β-CD and complex were studied by four-ball test using the mixture of PEG-600 and water as base fluid, and finally the lubrication mechanism of β-CD and the complex were analyzed using energy-dispersive X-ray spectroscopy (EDS). The experimental results revealed that the complex had formed well and had better antifriction and anti-wear property than β-CD. RC2540 in complex was released and the extreme pressure film was formed on the friction interface in the friction process. The β-CD molecules in complex were cracked into fragments, and the fragments with hydroxyl also formed lubricating film and fragments with no hydroxyl were mainly carbonized. The lubricating film of the complex had a better tribological performace due to the cooperation of the lubricating film of β-CD and extreme pressure film of RC2540.

Abstract: The extraction of baicalin, baicalein, wogonin and wogonoside from Scutellaria Baicalenses was performed using subcritical water. The effects of key operation conditions by varying the temperature (110-160 °C), extraction time (10-90 min), water loadings (2.0-4.0 mL)and particle sizes (>20- <100 mesh) were evaluated. The highest extraction yields of baicalin and wogonoside were obtained at extraction temperature of 160 °C, extraction time of 60 min, water loadings of 4.0 mL and 60-100 mesh. The highest extraction yields of baicalein and wogonin were obtained at extraction temperature of 110 °C, extraction time of 10 min, water loadings of 4.0 mL and 60-100 mesh. The subcritical water extraction was compared with the conventional extraction method. The total extraction yield by SCWE was higher than those obtained using ethanol as the solvent.

Abstract: In this article, the methylene diphenyl isocyanate (MDI) containing two benzene rings was used to modify montmorillonite. The detection analysis of the original MMT and the samples after modification were investigated by infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and thermo gravimetry (TG). Analysis of detection results shows that MDI and the surface of montmorillonite form chemical bonds and the spacing of montmorillonite layer increases from 1.24 nm to 1.86 nm. It provides highly active terminal isocyanate groups in situ polymerization for the montmorillonite and smart materials. It will improve the compatibility of the MMT and polymer, and allows the montmorillonite have always been able to maintain a good dispersion in polymer. Meanwhile the diphenyl isocyanate into ring can improve the heat stability of montmorillonite-modified polymer.

Abstract: Arginine in grape juice can be metabolized by wine yeasts to precursors of ethyl carbamate. The aim of this study was to develop a simple, accurate and fast method for determining arginine in grape juice by separating L-arginine with strong cation-exchange resins. The results showed that the optimized parameters as follows: 16g of pretreated resins packed in a glass column (D1.0×30cm), and 10.0mL of testing sample (pH = 2.0) added to the columns, kept for 20min at 20°C, then rinsed with pH 8.0 buffer solution. Finally, it was eluted with 300 mL 1 mol•L-1 NaOH at the rate of 2mL mol•min-1. The optimized method in combination with Sakaguchi reagents was simple, reproducible and accurate. This method can be applied for quick and fast determination of arginine in grape juice to take necessary action and avoid the forming of ethyl carbamate.

Abstract: Folin reagent was one of the most important reagents in protease determination. The differences between Folin reagent from laboratory and Folin reagent sold were studied. The results showed that there was not significant difference between the absorbance of Folin reagent from lab replaced 30d and Folin reagent sold (p<0.05). The RSD of Folin reagent from lab was between 0.3and 1.67, and Folin reagent sold between 0.63 and 1.49. The precision of them was both higher. The maximum absorption wave length of the chromogenic agent of Folin reagent was with 736-755. And there was no significant difference of the value of the same sample protease between both Folin reagent (p<0.05). Folin reagent from lab based on GB/T23527-2009 was perfect.

Abstract: Four kinds of X100 grade pipeline steels containing different chromium content were designed and corrosion behavior were studied in order to confirm the influence of Cr on the properties of high grade pipeline steel. The corrosion experiments demonstrated that Corrosion rates of Four steels in the experiment decrease with the increasing of Cr content, and the scales on the four steels have a two-layer structure under the corrosion of CO2 and H2S. The outer layer is mainly composed of FeS or FeS1-x and the inner layer consisted of FeCO3. Cr enriches in the inner layer and Cr content of the inner layer increases with the Cr content in matrix. The Cr enrichment enhanced the compactness of the scales further hindered the diffusion of ions from liquid to the surface of steel. The corrosion scale with Cr(OH)3 is anion-selective and reduce the amount of anion reaches metal surface, thus reducing corrosion rate.

Abstract: The value of Texture Profile Analysis (TPA) and microstructure of low- and full-fat cheese, fermented by L. acidophilus as starter culture and Str. Thermophilus as adjunct cultures, were changed after ripening for 90 d at 4 °C. The hardness, gumminess and chewiness of low-fat cheese were higher than that of full-fat cheese, while the springiness, cohesiveness and adhesiveness were less than that of full-fat cheese. The structure of low-fat cheese after ripening was more tightening and compact, while that of full-fat cheese had a lot of cavity.

Abstract: Using cutting speed and the roughness as index, the five factors as pulse duration, peak current, offset, ratio of pulse interval to pulse duration and worktable feed were chosen in dry finishing. Based on the single factor experiment, the central composite design (CCD) method is used to study the effects of the five factors and their interactions on cutting speed and the surface roughness and develop empirical models for cutting speed and roughness Ra. Significant order influencing cutting speed and roughness are found. The results of the verification test show that Ra regression model and cutting speed regression model have high reliability, and can achieve significant prediction effect.

Abstract: The red mud lightweight ceramsite was made by using red mud, fly ash and bentonite, mixed with a certain amount of pore-forming agent and cosolvent, through the roasting process. Influence of sintering temperature to red mud ceramsite was studied. The microscopic morphology of red mud lightweight ceramsite damage fracture was analyzed by using scanning electron microscope and the roasting mechanism was investigated preliminarily. The results show that for the best sample, its apparent density is 724kg/m3, its bulk density is 574kg/m3; its cylinder compressive strength is 5.5Mpa, the water absorption is 8.6%.

Abstract: The rapid hardening sulphoaluminate cement was used to prepare foamed cement by the chemical foaming method. The impact of organic and inorganic waterproofing agent on the water absorption, mechanical strength and softening coefficient of foamed cement were studied. The results showed that adding waterproofing agent could improve its foam structure and reduce the water absorption, improve its mechanical strength and softening coefficient, thus improving its water resistance; Organic waterproof agents had a better performance than inorganic waterproof agents. The mechanisms of action of different waterproofing agent were explored.