Advanced Materials Research Vols. 455-456

Abstract: The paper investigates the feasibility of integrating 1.5^th and 2^nd generation (G) conversion technology for ethanol production from sweet sorghum stalks, in terms of economic performance, energy consumption and greenhouse gas emissions (3E). To that end, discriminants were developed for economic analysis to determine the conditions under which the transition from pure 1.5^thG to the integration technology takes place. The paper also developed equations to calculate energy output/input ratio and carbon emissions during ethanol production processes. The results indicate that the main barrier of the development of integration technology is the high cost of 2^ndG ethanol production. The residues from 2^ndG production should be burned to supply energy for the ethanol plant, which is important to enhance the energy output/input ratio and to cut down carbon emissions. Compared with 1.5^thG technology, the integration pathway brings about higher energy output/input ratio, but with slightly less amount of carbon emission reduction. However, the absolute amount of carbon emission reduction is still considerable. The estimation shows that the integration technology is promising in long term but infeasible under current conditions.

Abstract: Multi-walled carbon nanotubes (MWCNTs), potassium dichromate (K2Cr2O7) and sulphuric acid were used for the preparation of Cr/MWCNT composite by impregnation method. The composites were comprehensively characterized by transmission electron microscopy （TEM），energy dispersive X-ray analysis (EDX), infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal gravity analysis (TGA). Due to its unique electrical and structural properties, this composite was applied to the synthesis of biodiesel (FAME) as a catalyst, showing effectively catalytic performance.

Abstract: Ethyl acetate was synthesized using inorganic salt as catalyst. The catalytic syntheses of Ethyl Acetate using NaHS04, Sncl2 and Fecl3 as catalysts were introduced. It showed that Sncl₂ was excellent catalysts for synthesis Ethyl Acetate with higher yields and the catalyst can be reused, and the reaction does not cause pollution.

Abstract: The fuzzy pattern recognition has been proved to be a kind of effective method, and fuzzy comprehensive evaluation method, this paper puts forward a aims to improve the analytic hierarchy process (AHP) application of fuzzy version in the real building materials optimization. According to the logic of the original (crisp) method to solve problems, decision and choice standard, balance by fuzzy framework has been created. Finally, a building materials optimization scheme is put forward a kind of fast, reliable program completion, it is never seen evaluation building materials.

Abstract: An experimental investigation was performed on fatigue crack growth behavior of a 16MnR pressure vessel steel. Standard compact tension (CT) specimens with three specimen thicknesses and notch sizes were subjected to Mode I constant amplitude loading with several stress ratios and loading amplitudes. The results revealed that the stress ratio had an insignificant influence on the fatigue crack growth of the material. The stable fatigue crack growth rate (FCGR) was accelerated as specimen thickness increased. The fatigue crack was extended in terms of the curve crack shape. The crack front at the surface was retarded compared to that at the interior along thickness direction, and the crack front at the mid-thickness plane reached the maximum value of the crack length. The similar curve crack shape was obtained in the stable crack growth stage. The maximum difference of the crack front along thickness direction was increased with the increasing of the specimen thickness. The early crack growth from the notch was effected by the size of the notch, the stress ratio and loading amplitude.

Abstract: Shantou atmospheric salt-fog environment is simulated with the comprehensive salt spray test chamber. By using reinforced concrete short beams under different water-cement radio, different corrosion time, the inclined section degradation rules of the corrosive reinforced concrete members are researched for establishing shear capacity of short beam formulas in salt-fog environment.

Abstract: . It is difficult to detect critical knock for a gasoline engine by the common method of knock diagnosis. In this paper, a new approach is presented to detect critical knock for gasoline engines. Based on this approach knock diagnosis consists of four steps. Firstly, discrete wavelet transform (DWT) is chosen as a pre-processor for a neural network to extract knock characteristic signals; Secondly, four characteristic factors are selected and calculated from knock characteristic signals; Thirdly, degree of memberships of the characteristic factors are calculated as the input and output of the neural network; and finally a RBF(Radial Basis Function) neural network is chosen, trained and applied to detect critical knock. Knock experiments were performed on a gasoline engine, and the application of the presented approach was studied. The results show that the presented method is practicable and can be applied to control the ignition of a gasoline engine working under critical knock which is admitted as an improved state of engine performance.

Abstract: The dynamics performance of the articulated steer vehicle is investigated in this paper. This six-wheel drive hybrid articulated vehicle is believed to have good performance because these six motorized wheels can be controlled independently. The hybrid vehicle is modeled as multi-body system that considers the nonlinear vehicle dynamics, tyre models. The transient response of the vehicle, such as yaw angle, tire lateral force and the torques at the wheel are simulated. The effects of the torsional stiffness, the position of center mass on the behavior of vehicle are presented. The simulation results show that the vehicle can be adaptive to the different working conditions by controlling the driving motor torque.

Abstract: In order to roundly investigate the whole structural behavior of the jointed pylon of cable-stayed bridge, 3:40 scaled-down model test and space finite element analysis （FEA） were presented by taking Yongjiang super-large bridge as an example. Test objective, model design principle, the ratio of similarity, test cases, loading method and the strain test point arrangement were introduced in detail. By comparison of two unfavorable cases, most test data were quite agreeable with the theoretical data, which verified the design concept. The results indicate that the whole resistant behavior is well and the structure is safe and reliable. FEA which is conducted using commercial program ANSYS is a reliable method for predicting the complex stress distribution in the jointed pylon structure.

Abstract: . In order to research the overall performance of the natural gas driven Vuilleumier (VM) cycle heat pump deeply, we adopt the fuzzy mathematical theory, the fuzzy comprehensive evaluation of performance of the natural gas driven VM cycle heat pump has been discussed in this paper from five aspects: technology, economy, safety, maintainability and environmental protection. Combine fuzzy comprehensive evaluation with performance study of the natural gas driven VM cycle heat pump; it is a effective way to improve scientific of the comprehensive evaluation and the reliability of the results.