Advanced Materials Research Vols. 233-235

Abstract: The bolt-flange structure is most one of joint mode, and stress and mass are its major performance parameters. The multi-object optimization of a bolt-flange structure can be performed by using Finite element method and optimization method unitedly. The response surface design method was employed to determine the combination of geometrical parameters to be designed of the bolt-flange structure. The stress of the bolt-flange structure which has the different geometrical parameters was numerically simulated and analyzed by using the software ANSYS. The response surface model is obtained. The optimized geometrical parameters of the bolt-flange structure were obtained by using MATLAB multi-objective optimization method. The results showed that the maximum equivalent stress in the optimized bolt-flange structure decreased 13.4% than that in the original one and the mass of the optimized bolt-flange structure was lower 14.3% than that of the original one.

Abstract: Hydrogen in the steel wall can cause hydrogen embrittlement of the wall material and thereby change the carrying capacity of the vessel. A theoretical model of hydrogen diffusion in the steel wall of a high pressure vessel was established and the formula of hydrogen content in the steel wall was deduced. Based on the hydrogen content formula, the formula of hydrogen pressure within microvoids which naturally exist in the steel wall of a spherical pressure vessel was deduced. At last, as an example to demonstrate the meaning of solving hydrogen pressure in microvoids, by using a representative volume element (RVE) model to carry out FE numerical simulation, the effects of hydrogen pressure on equivalent mechanical properties of the wall material were studied. It is found that the higher the gas pressures are, the lower the ultimate strength, specific elongation and percentage contraction of area are, which is in good accordance with the phenomena of metal hydrogen embrittlement.

Abstract: 2,3-bis(2-pyridyl)-5,6-dihydropyrazine and a protonated phenanthroline (Phen) have been synthesized and the structure of protonated Phen is established by X-ray diffraction single crystal structure analysis. The coordination reactions of Phen, 2,2'- bipyridine and 2,3-bis(2-pyridyl)-5,6-dihydropyrazine with rare earth ions in low pH have been studied. The results show that 2,3-bis(2-pyridyl)-5,6-dihydropyrazine is hydrolyzed to be 2,2’-pyridil and protonated ethylenediamine. Meanwhile, Phen combines with proton, which results that nitrogen atoms can not coordinate with rare earth ions. The molecular formula of protonated Phen is C₁₂H₈N₂HCl·H₂O. It crystallizes in the triclinic space group P -1 (2), with a = 7.1212(14) Å, b = 7.2786(15) Å, c = 20.817(4) Å, α = 90.00º, β = 96.69(3) º, γ = 90.00 º, V = 1071.65(379) ų, Z = 4.

Abstract: The paper chooses foreland basin as its research object. after summarizing the accumulation characteristics of the different phases and different parts of them, the common models of the whole foreland basin are given and the physical simulation experiments are carried out. It shows that the foreland basins experience three phases of evolution. Phase 1 is the period that the source rock and structure oil and gas traps form. Phase 2 is the period that multi-cycle reservoir and lithologic oil and gas pool form. phase 3 is the period that foreland uplift belt and fault anticline pool form. Then a foreland basins has three different belts including of thrust belt, foredeep and foreland slope belt, foreland uplift belt, and the belts have different accumulation models. With regard to the hydrocarbon accumulation period of the foreland basin, the thrust belt have precedence to other belt. foredeep and foreland slope belt forms the secondary pools. Foreland uplift belt accumulates hydrocarbon very quickly.

Abstract: Ball valve with large-diameter, high-pressure, corrosion-resistant and high-reliability has been used for West-East Pipeline. In order to improve the product reliability and safety, reduce the product consumption and costs, and shorten the product design cycles, finite element analysis(FEA) has been used to simulate the strength and sealing analysis process which can’t be proceed on site or in the real environment. The results illustrate the stress and loading distributions as well as pre-identify the potential problems, which show that the strength and sealing of the valve in three different conditions is very safe.

Abstract: In this paper, a neural network method is proposed to solve a one dimensional inverse heat conduction problem (IHCP). The method relies on input/output data of an unknown system to create an intelligent neural network model. Multi layer perceptrons with recurrent properties are utilised in the model. Prepared input/output data are used to train the neural network. Reliable checking processes are also offered to justify the robustness of the method. A numerical sequential function specification (SFS) method is used as another technique to solve the IHCP. The numerical result is compared with that of the proposed method and good agreement is shown between the two methods. However, the numerical method can be only used to solve the IHCP off-line due to the high computation requirement. The proposed neural network method can be used in real-time situations as shown in the experimental tests.

Abstract: Brewers’ spent grain (BSG) is the most common by-product of the brewing industry, contains about 16.8% cellulose, 28.4% non-cellulosic polysaccharides and 27.8% lignin, which is a good raw material for industrial production of soluble dietary fiber (SDF).The antioxidant activity of crude dietary fiber (CDF) and grade dietary fiber (GDF) isolated from BSG was investigated in vitro. The scavenging hydroxyl radical capability of CDF and GDF was respectively reached to15.4% and 69.2% at the concentration of 0.1mg /mL. DF concentration from 0.02mg /mL to 0.1m g /mL was used. The scavenging capability of CDF and GDF to superoxide anion radical was increased from 10.68% and 12.33% to 35.78% and 78.39%. Both of the two DF showed some effect in scavenging superoxide radical and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) radical with the concentration increase. The result showed that BSG DF can be used as a good additive with some functionality.

Abstract: To enhance the water solubility and inhibition efficiency of 2-phenyl-imidazoline, a type of imidazolinylquaternary-ammonium-salt（IMA）was synthesized from 2 - phenyl-imidazoline and benzyl chloride.And then the compound inhibitor was manufactured with IMA, potassium iodide, triethanolamine, polyoxyethylene ether and peregal by weight loss through orthogonal experiment. The effect of the compound inhibitoron on corrosion of A20 carbon steel in hydrochloric acid have been investigated in relation to it’s concentration by various corrosion monitoring techniques. Polarization studies showed depression of cathodic and anodic polarization curves in the presence of the compound inhibitor, indicating mixed type inhibition. EIS results show that the changes in the impedance parameters (R_p and C_d) with concentrations of the compound inhibitor are indicative of the adsorption of these molecules leading to the formation of a protective layer on steel surface.

Abstract: Originated from(C₄H₉O)₄Ti, TiO₂ was synthesized by low temperature hydrolysis process in this paper. After being prepared by decomposing ammonium tungstate and covering on the surface of TiO₂, TiO₂/WO₃ were characterized by XRD, DRS, FS. With sunlight as the light source, pH=5.0, catalyst concentration was 1.0g.L^-1, concentration of methyl orange was 5.0mg.L^-1.It has been shown that TiO₂/WO₃ powders(15%,873K) has the most photodegradation efficiency, and the degradation efficiency of 95% after 4 hours.

Abstract: In this paper, we have studied the hot forming process of composites made by polylactic acid (PLA) and corn straw fiber. In order to obtain the composite cushioning material with ideal density and expansion ratio, the parameters of processing was optimized. It showed that the optimum condition as follows: the hot-press time was 5min, the pressure was 15MPa and the temperature was 200°C. The structure of the composite was characterized by FTIR.