Applied Mechanics and Materials Vols. 548-549

Abstract: In this paper, anaxis-symmetry mode is set up to simulate the high speed liquid-solid impact of 17-4ph material, which is widely used inwet steam turbine bladesof the nuclear power units. The initial speed of the droplet with the diameter of 0.3mm is 400m/s. The deformation of the solid and the stress distribution variation with time are obtained via numerical method. And the variation of the pressure inside the droplet and solid target has also been analyzed in detail. In this case, the maximum pressure in the vertical direction of the solid is 1099MPa, and the maximum deformation distance of the plateis 140nm. The results provide useful supplement and reference to the high-speed liquid-solid impact theory.

Abstract: Vanadium oxide nanoparticles were synthesized with controlled size and dispersity by gas phase cluster beam deposition. The composition of the nanoparticle film is dominated with VO₂ nanoparticles. The VO₂ nanoparticles undergo a phase transition between the room temperature monoclinic insulator phase and the higher temperature rutile metal phase. In the metallic phase, the VO₂ nanoparticles exhibit a strong surface plasmon resonance in the near-IR region from 900nm to the 2000nm, which generates a large enhancement on the extinction coefficient. This plasmon resonance is thermally controlled by the VO₂ MIT and can be used to improve the optical switching characteristics of VO₂ based devices in the near-IR region.

Abstract: In order to reduce the production cost of biodiesel, the transesterification process under ultrasound-assisted condition is studyed in this paper by using heterogeneous solid base catalyst NaAlO₃/Al₂O₃ instead of the traditional homogeneous catalyst. Through one-factor experimentation, ultrasonic frequency, oil-alcohol molar ratio, catalyst amount and reaction time on the yield of biodiesel are examined. Transesterification conditions are optimized through orthogonal experiment and the effect order of four factors is as follows: ultrasonic frequency >molar ratio of methanol to oil > reaction time > the amount of catalyst. Results show that the amount of catalyst and reaction time are reduced under ultrasound-assisted condition, and the optimum preparation conditions are: 20min of reaction time, 28KHz of the ultrasonic frequency, molar ratio of methanol to oil 9:1 and 2% catalyst. Under above conditions, the yield of biodiesel reaches 95.21%.

Abstract: A series of waterborne polyurethane (WPU) with different soft segment structures were sythesised, and the effects of the structure and molecular weight of the soft segment on the degree of PU microphase separation were evaluated by the infrared spectroscopy (FTIR) computer peak fitting. The experiment results indicated that phase separation between hard and soft segments of poly (ether–urethane) was more significant than poly (ester–urethane), based on the qualitative analysis on the N–H stretching region of the FTIR spectrum. And the qualitative analysis on the carbonyl stretching region showed that PU with lower soft segment molecular weight had a higher relative amount of hard segment, and possesses higher microphase separation degree. The addition of polyether soft segment PEG had an internal plasticization by actuating the PCD molecular chain. Therefore, it becomes easier for PU to conduct structure adjustment and increased the phase separation degree.

Abstract: This paper reports the preparation of Fe_xTi alloys from natural ilmenite by electro-reduction in molten CaCl₂. The electro-reduction experiment was carried out at 1000 °C and potential of 3.8 V, and an inert solid oxide oxygen-ion-conducting membrane (SOM) anode system was used to control the electrochemical experiment. The phase composition and morphology of the final product were investigated. The reaction mechanism involved in the electro-reduction process is discussed based on our experimental results and thermodynamic analysis. It is suggested that Fe_xTi alloys powder with different Fe contents (Fe_xTi, 0 ≤ x ≤ 2) and particle sizes can be obtained by controlling electrolysis conditions strictly. The result implies that the SOM process is a promising green method for the preparation of ferrotitanium alloys direct from natural ilmenite.

Abstract: The losses due to copper corrosion in H₂S atmospheric corrosion have attracted much focus. It’s important to improve copper corrosion resistance that the corrosion law, corrosion mechanism and characteristics were studied in H₂S environment. This paper reviewed the corrosion behavior of copper, analyzed the impact of environment factors and corrosion analysis tools. Through evaluating and improving corrosion by external factors, including improving corrosive environment, using coating protection and adding corrosion inhibitors, appropriate corrosion measures were taken to extend the life of the equipment.

Abstract: We propose and theoretically study a novel plasmonic nanostructure composed of two malposed silver (Ag) triangular nanocylinder arrays by the finite-difference time-domain (FDTD) method. The excitation of the localized surface plasmons (LSPs) of the metal triangular nanocylinders, and the strong interaction coupling between LSPs contribute to the enhanced transparency in the visible and near-in region (NIR). The transparency response in the proposed nanostructure is modified by changing the gap distances between two adjacent triangular nanocylinders, and the dielectric environments. The tunable enhanced optical transparency of the proposed nanostructure provides potential applications in sensors and plasmonic filters.

Abstract: During the period of building construction on the beach clay, the sludge foundation treatment of large area is the most important issue. The chemical strengthening of silt using curing agent is one of the effective and feasible foundation treatment methods. In order to obtain the physical characteristics of stabilized soil, a great deal of laboratory tests were done to study the strength of stabilized soil which were prepared using beach clay as raw material, cement as curing agent, composite additives as additive agent, and the best ratio for silt is obtained. The microscopic characteristics and curing mechanism of stabilized soil is studied using the microscopic test to analyze the pore structure of stabilized soil. The test results show that the ratio of the curing agent has a positive effect, and can provide fundamental basis for the engineering application of the coastal mud flat silt solidification.

Abstract: This paper reported on the product yield of automotive paint sludge via microwave assisted pyrolysis. By having an optimum weight sample loading and power level at 500g and 1000W respectively, optimum product in terms of liquid yields has been obtained. This desired liquid product comprised hydrocarbon material since it contains oil layer and almost 40% of the product can be recovered from the automotive paint sludge with an optimum microwave parameter. Furthermore, the liquid product has a potential to be used as fuel since it exhibit high energy content at 22.6 MJ/kg.

Abstract: Zinc oxide (ZnO) on silica modified polyaniline (SM-PANI) was prepared via chemical bath deposition and in situ polymerization. The optical characteristics of the nanocomposites were investigated using ultraviolet-visible (UV-Vis) spectroscopy. The bands showed higher absorbance in the visible region. Fourier transform infrared (FTIR) spectroscopy revealed that there is an interaction between SM-PANI and ZnO.