Applied Mechanics and Materials Vol. 483

Abstract: The effect of particle size of BNT filler on the microstructure, dielectric and mechanical properties of the x BNT - (1-x) LCP composites (x = 40 Vol.%) was investigated with SEM, Impedance analyzer and Universal Test Machine, where BaNd₂Ti₄O₁₂ (hereinafter referred to as BNT) and Liquid Crystal Polymer (hereinafter referred to as LCP). BNT fillers of median particle size of 2.45, 1.39 and 0.69 um were obtained by ball milling for 24, 48 and 72 hours, respectively. BNT and LCP powder were mixed uniformly with twin screw type extruder. Disk samples of 20 mm in diameter and 1 mm in thickness were fabricated with hot press using mixture. As the particle size of BNT filler decreases from 2.45 to 0.69 um, the dielectric constant of composite measured at 10 kHz increases monotonically from 4.8 to 7.2 and its tan δ increases linearly from 0.0052 to 0.0068. Its flexural strength also enhanced with increasing the particle size of BNT filler. It was observed that the smaller particle size of BNT filler is more effective for increasing both dielectric constant and mechanical strength of BNT - LCP composite.

Abstract: The fresh and elegant appearance, and convenient processing properties make wood become the main material of outdoor furniture design. However, there are limitations in the application of wood, for the lumber cycle of wood is too long, which results in a severe market shortage. Bamboo is a fast-growing material, which can exactly make up for the lack of wood. Whats more, bamboo has a profound cultural connotation and natural appearance. If combine wood and bamboo together, and assemble their advantages effectively, a perfect effect can be obtained. This paper summarizes the characteristics of bamboo and wood, and discusses the advantages and rationality of the combination of bamboo and wood from the material physical properties, the relationship between market supply, Manufacture and cultural implication.

Abstract: 3-dimentional CFD Numerical analyses were conducted. Major dimensional parameters were considered in the simulation and meaningful air flow rates were observed under normal conditions. to fully understand the physical mechanism of the phenomenon by air buoyancy. Based on the results of the study, the proposed solar panel chimney and its advantages are worth of further investigation. Based on this innovative concept, the rooftop solar panel could be re-arranged, grouped and boxed to form an effective solar panel chimney, to serve as passive ventilation system without much cost and fully utilize the solar power.

Abstract: As a continuous effort to develop a realistic mist impingement cooling scheme, this paper focuses on simulating mist impingement cooling under typical gas turbine operating conditions of high temperature and pressure in a simplified model of transform piece (double chamber model). Based on the heat-mass transfer analogy, the results of mist cases compare with the none droplet case could be enhanced 320% (the maximum enhancement of adiabatic cooling effectiveness) cooling effectiveness and reduce 108 K of wall temperature.

Abstract: This paper presents the simulation and testing of Vibration-to-Electrical Power Generators (VEPG) with different kinds of permanent magnet oscillators for scavenging ambient vibrations. The finite element method is used for magnetic fields calculation. Firstly, single permanent magnet type oscillators are simulated under the sinusoidal vibration. The calculation results show that the permanent magnet oscillator with diameter 20 mm and height 5 mm will realize 4 V peak-peak voltage. Secondly, multiple permanent magnets type oscillators are simulated under the same vibration and comparative studied with the single permanent magnet type. The results show that multiple permanent magnets oscillator with suitable structure will dramatically improve the power density of VEPG. By the end, prototypes with different kinds of oscillators are tested on the condition of sinusoidal vibration. And the experimental results agree well with the simulation ones.

Abstract: The flow of liquefied natural gas (LNG) which was coupled between heat transfer and fluid-flow in rib-tube was studied in this paper. Based on theoretical analysis, the model and wall-function were chosen to simulate the flow field of rib-tube, and the multiphase flow was described by the mixture model, in which the dispersed phase was defined by different velocity. In addtion, self-defining functions were used and governing equations were set up to solve the dispersed phase, and the result were compared with the experiment. The process of fluid-flow and heat exchange on rib-tube was simulated, and the contours of temperature, pressure, velocity, gas fraction were obtained, which showed that, the parameters of above changed when the temperature was rising and the LNG evaporating along the rib-tube, and a mixed process existed in the middle of the heat tube.

Abstract: The V / H inspection method is analyzed, including its basic definition, purpose and V / H inspection technical process of Gleason Company. In order to improve the quality of the contact region, Gleasons V / H test method is conducted for V/H inspection of spiral bevel gear before heat treatment, and analysis of experimental data is given.

Abstract: A method is proposed to exactly diagonalize the Hamiltonian of a N-layer quantum dot containing a single electron in each dot in arbitrary magnetic fields. the energy spectra of the dot are calculated as a function of the applied magnetic field. We find disco-ntinuous ground-state energy transitions induced by an external magnetic field in the case of strong coupling. However, in the case of weak coupling, such a transition does not occur and the angular momentum remains zero.

Abstract: Abstract:.:Intelligent teaching Dynamic balancing is a new kind of dynamic balancing test system with various functions of teaching need. It integrates the hard bearing method using A, B, C size solution with soft bearing method using the influence coefficient method solution. The system is mainly composed of machine frame, intelligent electric measuring box, high sensitive sensor and far infrared phase sensor. It has the advantages of small volume, simple operation, security with low speed，reliable and convenient operation for students. It can deepen students' understanding of balancing knowledge, which has won the national utility model patent.

Abstract: Abrasive waterjet (AWJ) machining is an emerging machining method to process all kinds of difficult-to-cut materials. In this paper, a mathematical model for the surface roughness generated by a radial-mode AWJ turning process on a high-tensile steel specimen is developed using a dimensional analysis technique. To verify the model, a series of statistically designed experiments are carried out where feed speed, water pressure, abrasive flow rate, nozzle tilt angle, and workpiece surface speed are considered as variables. The model predictions are found to be in good agreement with the experimental results with the average error of 4.3%. Future research to advance the knowledge about this new machining process is also proposed.