Applied Mechanics and Materials Vols. 511-512

Abstract: The effect of high oxygen treatment on quality of Fuji fresh-cut apples during 24 days of storage at 4°C was investigated. Results indicated that the high oxygen could significantly inhibit the browning as well as keep the sensory quality of fresh-cut apples. Moreover, the treatment of 100% oxygen for 5 days better maintained the color and firmness, also with higher contents of the total soluble solids and titratable acid of fresh-cut apples, compared to the other treatments.

Abstract: The apparent wall slip flows of incompressible and viscoplastic fluids in plane pipeline were analyzed assuming that the apparent slip layer consists solely wall slip layershear layerslug flow part and they are independent of the flow rate. Taking coal slurry for example,the experiment is conducted on pressure pipe rheological and resistance characteristic test system. It studies how two key factors (the particle concentration and the pipe diameter) influence the dense paste wall slip velocity. The assumed apparent slip mechanism provides methodologies for the determination of the slip velocity values that are consistent with the traditional Mooney method and furthermore allows the determination of the true shear rate of the dense paste at the wall and the yield stress. The analysis of the slip data of various dense pastes of rigid particles reveals that the apparent slip layer thickness is related to the particle concentration and the pipe diameter.

Abstract: This paper regarded the sediments of Lake Baiyangdian as the object of study, researched and analyzed ammonia nitrogen adsorption characteristics of sediment samples. The results showed that: the sediments adsorption to ammonia nitrogen reached a state of equilibrium after 2.5h, The ammonia nitrogen adsorption rate was maximum in 0~10min. Sediment adsorption of ammonia nitrogen was higher as ammonia nitrogen liquid balance concentration increased. The adsorption isotherm curve of ammonia nitreogen can be fitted well by the Langmuir adsorption isotherm model. The total maximum adsorption quantity of ammonia nitrogen by the sediments of Lake Baiyangdian is between 54.12mg/kg to 240.12mg/kg.

Abstract: Microstructure of Ti-6Al-4V laser weld joint heat affected zone was observed. The results suggested that the heat affected zone microstructure first transformed to lamellar structure, then the grain growth and transformed to equiaxial grains. At the same temperature, the grain growth rate was faster at lower deformation rate, and the microstructure was more uniform.

Abstract: Deformation behavior of steel 33Μn2v for oil well tube was studied by hot compression tests conducted at various temperatures and strain rates.The Kumar model was developed to predict the hot deformation behavior of steel 33Mn2V for oil well tube.In this regard,the hot compression tests were carried out at the temperatures from 750°C to 1200°C and at the strain rates of 0.02s¹ to 0.16 s¹.The experimental data were then used to determine the constants of developed constitutive equations. The Kumar model can be represented by ZenerHollomon parameter in a hyperbolic sinusoidal equation form.The apparent activation energy of deformation is calculated to be 342.1481kJ/Mol.Dynamic recrystallization of steel 33Mn2V occur and the completion of the critical deformation is small,termination error and the initial deformation is smaller.Therefore,its easy for the steel 33Mn2V to the occurrence and completion of dynamic recrystallization.

Abstract: Taking the finite element method, the resonant frequency of the 1-3-2 type piezoelectric composites is calculated by finite element analysis software ANSYS. The relationship between the thickness of the composite material and its resonant frequency of admittance characteristics are calculated. The different structural parameters 1-3-2 type piezoelectric composite material samples are designed and prepared. The results show that the theoretical calculations are well matched with experimental results .

Abstract: Using relaxor ferroelectric single crystals PMNT as piezoelectric phase and epoxy resin as a non-piezoelectric phase material, the piezoelectric composite is fabricated with the cutting - filling method. Using the same micro-structure parameters and the same process, the piezoelectric composite is prepared with the conventional piezoelectric ceramic PZT5 as piezoelectric phase material. The transducer array is respectively assembled with the PMNT /epoxy composites and PZT5/epoxy piezoelectric composite materials. Experimental results show that the relaxor ferroelectric single crystals PMNT / epoxy composite transducer array has higher sensitivity and less resonant impedance than PZT5/epoxy piezoelectric composite transducer array.

Abstract: Nd:YAG nanopowder was prepared by urea co-precipitation method. XRD, TG-DTA, SEM and spectra analysis were utilized to study the properties of the powder. Results indicated that fine Nd:YAG nanopowder can be acquired at 1000°C for 10h. The fluorescence spectra shown that the strongest peak was located at 1061nm, corresponding to the ⁴F_3/2⁴I_11/2 energy level transition of Nd³⁺ ion.

Abstract: Improvement of long-term stability is one of the major issues of SOFC. Research efforts are being made to clarify the mechanisms of cell performance degradation and to improve durability effectively. It is necessary to quest for potential degradation sources of all sorts. In this work, influence of sulfur concentration on the performance and durability of SOFC cathode has been studied, and degradation behavior was analyzed for conventional cathode material, (La_0.8Sr_0.2)MnO₃ (LSM) by GCI technique.

Abstract: The effect of carbon ion species distribution in arc discharge process becomes significant for the formation of carbon nanomaterial. It is essential to account for the velocity distribution of each carbon ion species to determine the greatest contribution from the kinetic energy possesses by each species that govern the binding energy for carbon formation. The resultant speed of the particle as a result of collisions determines the resultant force exerted by the particles which consider in non-conservative force. The variation of velocity distribution is investigated while the reaction rate for carbon species during kinematic process, the transient condition for carbon species is analyzed. Collision rate of carbon ion species is underway to derive carbon ion motion in electrode gap region where the external electric field is constant. The theoretical development has shown that at constant pressure and temperature, carbon ion species possess the resultant speed due to collision frequency affecting the distribution function quantified for each species.