Advanced Materials Research Vols. 472-475

Abstract: The performances of paper pulp mould and foam net as packaging materials for mango transportation were studied and compared. Mangoes were packed in both types of packaging materials, vibration tested, and left for 24 days. Firmness, weight loss, and colour changes were measured. It is found that firmness of mangoes in both types of packaging during the first 3 days and slowly afterwards. The performances of both types of packaging are similar. Paper pulp mould performed better with regards to weight loss. Colour changes as measured by lab equipment are not conclusive but through naked eyes paper pulp mould seemed to perform better. It is concluded that paper pulp mould as a packaging material performs better than foam net in some respects, therefore an interesting alternative packaging material.

Abstract: The pipe model is simplified as elastic foundation beam model of Euler-Bernoulli, the form of pin rocker bearing in the analysis of transverse vibration in the paper. According the principle of Hamilton, after a series of variation, exchanging the order of integral and integration by parts, the transverse vibration differential equation of pipe is obtained without fluid. Considering different boundary consitions, the solving process is carried out. By utlization of MALAB language, the numerical example is analyzed, considering fluid and foundation. Thus, the fluid-solid coupling interaction is not ignored in transverse vibration in the buried pipeline.

Abstract: Ultranarrow gap welding with the gap of less than 5mm was executed successfully. In order to prevent the arc from being attracted by sidewall and going up along the sidewall, the flux strips consisting of the specified aggregates are placed onto the sidewalls to constrain the arc. This technique was tested on the welding experiment of pipeline steel with thickness of 30mm. The involved welding parameters were obtained. The width of gap is 4mm, the welding voltage 20~24V, and the heat input 0.6 KJ/mm. The cross sections of weld profile were analyzed. The width of heat affected zone is relatively narrow and about 1.3mm, and the weld hardness is much higher than that of HAZ and base metal.

Abstract: A novel electrolyte membrane PVDF-Al₂O₃-CsHSO₄ usable at medium temperatures was prepared by composite of PVDF and an inorganic proton conductor Al₂O₃-CsHSO₄. The membrane has a steep increase in proton conductivity around 90°C and retains the high conductivity, about 10^-3 S•cm^-1, up to 200°C. The incorporation of Al₂O₃-CsHSO₄ with PVDF leads to a dramatic improvement of the properties of PVDF, including widen the phase transition temperature of CsHSO₄, improve proton conductivity and enhance chemical stability over wide temperature range.

Abstract: In order to develop theoretical instructions for design of high performance linear motor, a piezoelectric linear motor based on an H-shaped vibrator is proposed, which employed the vibrator’s 2nd bending vibration mode and 1st longitudinal planar vibration to drive the motor in this paper. Firstly, the driving principle of the motor is presented, and the elliptical motion generated on the driving end of the vertical bars of the vibrator is proved. Then, FEM simulation model is built for the vibrator, which is used to calculate the vibrator’s working modes and to execute harmonic response analysis and sensitivity analysis for the vibrator. Furthermore, the vibration’s optimal size is given and the motor assembly structure is designed. Finally, modal test is done for the vibrator to validate the anticipated work modes vibration and the bending vibration and longitudinal planar vibration could be 1.4μm and1.2μm under normal drive.

Abstract: In this study, wheat-straw lignocelluloses were liquefied in liquefaction solvents. Polyethyleneglycol 400 (PEG 400) and ethylene glycol (EG) were used as main liquefaction solvents. The effect of liquefaction time and liquefaction solvents on the properties of liquefied products was investigated. As the reaction time increased, the hydroxyl value, residue content and viscosity decreased, and the acid value decreased gradually in the previous period of time then increased. The optimum liquefaction conditions were as follows: wheat-straw lignocelluloses with steam-explosion pretreatment, the main liquefaction reagent of PEG 400, auxiliary liquefaction solvents of glycerin, catalyst of sulfuric acid, liquefaction temperature of 150°C, liquefaction time of 4 h. The hydroxyl value of liquefaction product was 206 mgKOH/g, the residue content was 0.19% and the viscosity was 88 mPa•s.

Abstract: Mg films were prepared by magnetron sputtering on zirconia substrate. The surface morphology, structure and adhesion performance were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and automatic nano scratch tester, respectively. The results show that the Mg films deposited on the substrates at 50 °C, 200 °C, 300 °C are mainly of hexagonal phase with the crystal planes (002) in highly preferred orientation that is weaken with the substrate temperature increased. After annealed at 230 °C, the quality of thin film deposited on the substrate at 50 °C can be improved as crystallizability enhanced and grain size increased. The adhesion of Mg film increases firstly, and then decreases with increasing the substrate temperatures.

Abstract: Machine thermal equilibrium seriously influences the machining accuracy,a significant amount of research has been dedicated to the task of achieving and reasonablely controlling the thermal equilibrium time.In this paper,based on the analysis of the trait of thermal equilibrium process of machine tool ,the affection of room temperature and spindle speed on this process and the temperature when each point reaches to the heat balance is investigated.A new method of estimating thermal equilibrium time of each measured points based on spindle thermal model theory and multivariate optimization is presented,the results are analysed,further research about the control of machine thermal equilibrium process can be made based on this paper.

Abstract: The characteristics and causes of the formation of adiabatic shear bands (ASB) in 30CrMnMo armor steel plate are analyzed by shooting 93W projectiles. The results show that adiabatic shear bands do not occur in the initial stages of the opening-crater and plugging. Adiabatic shear bands distributed sparsely appear in the stable penetrating phase because of the necessary strain volume. Adiabatic shear bands are formed along main shear stress lines at an angle of about 450 in relation to the penetrating direction. These are approximately consistent with the direction of the plastic deformation slip line. The non-homogenous deformation and centralizing of stress and strain inside the adiabatic shear band causes micro-cracks and micro-bores during cooling of the plate.

Abstract: The purpose of this study was to introduce the design and realization about a measurement system, which is based by accelerometer ADXLl05 and wireless data-transmission module for starting line of athlete’s reaction time. This system plotted curves of players’ reaction time using 89C205l as the core of the front-end of the system reaction time measurement device, the measurement device take real-time captures players' reaction time, and then sent over the wireless data-transmission module player reaction time to the PC machine to display, and to record the reaction time.