Advanced Materials Research Vols. 774-776

Abstract: A series of water-swelling rubbers (WSR) were prepared by directly mixing room temperature vulcanization-2 components silicone rubber (RTV-2 SR) with superabsorbent polymer (SAP) and nanofiller (s) (halloysite nanotube or/and CaCO₃). The effects of component on its mechanical behaviours and water-absorbent properties such as degree of swelling, swelling ratio, and weight loss ratio were investigated. The equilibrium swelling ratio increased with increasing amounts of water-absorbent resin. Well-dispersed nanofiller (s) increased the mechanical properties of WSR and prevented SAP breaking off from the elastomer network to effectively enhance the water-swelling durability of WSR.

Abstract: The quest for the advanced functional material of superior functionality for advanced structure is being driven in various fronts of engineering materials. One of such front is metal matrix composite (MMC) which has already been proven as one of the most productive field in that respect. With the advance of technology, now it is possible to reinforce the MMCs with nanosized particles compared to conventional micron-sized ones. However, the addition of nanoparticle in the MMC to improve its mechanical properties is not unconditional. To achieve positive gain by adding nanoparticles in the MMCs, all the influencing factors should be taken into consideration. The present paper reviews the failure mechanisms of nanoparticles reinforced MMCs in light of its strengthening mechanisms.

Abstract: This paper studied the removal effect of domestic sewage nitrogen and phosphorus during the start-up period of underground infiltration system. The experiment is conducted under the conditions of influent temperature 9~10°C, hydraulic loading 0.04m³·m^-2·d^-1, COD concentration 112.31~143.49mg / L, NH₄⁺-N 20.93~27.26mg / L and TP 2.12~2.86mg / L. The experimental results showed the removal rate of COD, NH₄⁺-N and TP was 80%, 98% and 95% respectively. In the start-up period, TN removal was not obviously for 34% removal rate. After treated the effluent nitrate nitrogen concentration was high, showing during the start-up period the nitrification was better than the denitrification. Lacking of carbon source and low temperature may account for this. To improve the conditions of the start-up period, promoting denitrification was the key to improve nitrogen removal rate by underground infiltration system.

Abstract: This review presents the oxidation of organic compounds, X (organosulfur compounds, amines, phenols, alcohols, hydrocarbons, ascorbate, and pharmaceuticals) by ferrate (VI). The rate of reactions of these compounds with ferrate (VI) usually decrease with increase in pH in alkaline media. The reactions of ferrate (VI) with compounds may be characterized most commonly by (i) a 1 e^- transfer step from Fe (VI) to Fe (V), followed by a 2 e^- transfer to Fe (III) as the reduced product (Fe^VI Fe^V Fe^III), and (ii) 2 e^- transfer steps (Fe^VI Fe^IV Fe^II). Oxygen-atom transfer to the compounds may occur through involvement of either ferrate (VI) in the oxidations carried out by ferrate (VI). Oxidation of biological species by ferrate (VI) is also briefly presented.

Abstract: In the present work, Cr₂O₃-Al₂O₃-Cr coatings are prepared on Q235 steel by aluminothermic process based on Cr₂O₃ Al system, using Cr₂O₃ as diluents while a small quantity of Fe₂O₃ to reduce reaction temperature. The results showed that after treated at 650oC for 30minutes, homogenous Cr₂O₃-Al₂O₃-Cr coatings can be prepared on Q 235 steel by aluminothermic process with the powders mixture with weight ratio of Cr₂O₃: Fe₂O₃: A1 equal to 4: 0.3: 1.12, while coatings prepared by mixture with superfluous aluminum are fragmentary. Surface hardness of the coatings prepared with superfluous Cr₂O₃ is about 23.9GPa while that of the coatings prepared with superfluous Al is about 10.9 GPa and large scatter of 13.7% in hardness.

Abstract: As the main carrier for the protective casing purposes, cementing material is an important part in cementing design. In order to obtain a high temperature and high pressure resistant cementing material with low elasticity, we investigated on the high-temperature resistant cementing material used in geological exploration drilling materials to seek better cementing material for fulfilling requirements of high-temperature, and to find the best formula using orthogonal test. With compositions of the material in different proportions, this article investigated performances of the cementing material, as thickening time, loss of water, and compressive strength. By comparison, high-temperature resistant cementing materials experimental technology program has been finally estimated, and the composition ratio of the components are determined.

Abstract: This study synthesizes a series of aliphatic biodegradable poly (butylene succinate-block-1,3-propylene sebacate) (PBS-b-PPS) copolyesters by incorporation of PPS into the PBS molecular chains at various molar ratios. The effects of these compositions on the thermal properties, crystallinity and biodegradability were investigated.The PBS-b-PPS were characterized using ¹H NMR, DSC and POM.Biodegradability was evaluated by enzymatic hydrolysis with a lipase from Pseudomonas cepacia. The copolyesters might be potentially useful as the biodegradable materials.

Abstract: In this paper the strain hardening property and the bake hardening property of an original dual phase steel with high Aluminum had been studied. It can be disclosed that the dual phase steel has an excellent strain hardening property and bake hardening property with a strain hardening value of 125MPa and a bake hardening value of 60MPa as well as a total hardening value of 162MPa. The excellent properties of bake hardening and strain hardening will make some contribution to the application properties of the auto parts made by the new dual phase steel. Key Words:dual phase steel, strain hardening, bake hardening

Abstract: Nanorods of platinum with an average length of 500-1000nm have been prepared by a simple reaction between H₂PtCl₆·6H₂O and ascorbic acid in the presence of deionized gelatin at room temperature. Gelatin played a decisive role as an inhibitor of the direct reaction of ascorbic acid with H₂PtCl₆·6H₂O and coagulation of the growing platinum in producing the nanorods. In the absence of gelatin, we can only obtain irregular large platinum particles. The products were characterized by X-ray powder diffraction, scanning electron microscope and X-ray photoelectron spectra.

Abstract: Surface cracks with aspect ratio can occur in pipelines subjected to corrosion attacks. There are few studies on interaction relationship for double semi-elliptical surface cracks with such high aspect ratio. This paper attempts to develop a finite element method to determine on interaction of two semi-elliptical internal surface cracks with high aspect ratio by analyzing two key fracture mechanics parameters, i.e., the stress intensity factor and the-stress. The numerical results prove that the existing flaw-interaction criteria are too general to lose the worthy of application especially in pipeline engineering.