Advanced Materials Research Vols. 457-458

Abstract: This paper is mainly about power quality monitoring system analysis method, designs and implements the system based on object-oriented UML platform. Combined with UML modeling language CASE tool rational Rose, and further analysis, finally realize the power quality monitoring system.

Abstract: This paper presents the changes on phase structures of niobium alloyed ductile iron after austempering process which started by austenitizing process at 900°C and held at 350°C for 1 hour, 2 hours and 3 hours in salt bath furnace. The phase structure were observed by light microscope, and then verified through X-Ray diffraction (XRD). The phase structure of as cast niobium alloyed ductile iron mainly consists of graphite nodules embedded in ferrite and pearlite phases with presence of niobium carbide. Austempering process resulted in the structure of graphite nodules embedded in ferrite platelets and bainitic structures. Increasing the austempering holding times had resulted in coarsening of the ferrite platelets structures and transformation from lower bainite to upper bainite structures.

Abstract: In this paper，study water content and water stability of AC and SMA asphalt mixtures, and reach the following conclusions. In the normal saturated condition, the maximum water content of AC and SMA asphalt mixture is 0.28% and 0.32%.And in the vacuum saturated condition, the maximum water content of AC and SMA asphalt mixture is 0.8% and 0.78%.The water of AC and SMA asphalt mixture separately take 8 days and 9 days to drain completely in the normal saturated condition. But in the vacuum saturated condition, the time is more than two months. In different water content conditions, the splitting tensile strength of AC asphalt mixture is 0%> 100%> 25%> 75%> 50%.But the splitting tensile strength of SMA asphalt mixture is 0%> 100%> 25%> 50%> 75%.

Abstract: The laminar convective heat transfer behavior of CuO nanoparticle dispersions in water with three different particle sizes (23 nm, 51 nm, and 76 nm) is investigated experimentally in a flow loop with constant heat flux. The main purpose of this study is to evaluate the effect of particle size on convective heat transfer in laminar region. The experimental results show that the suspended nanoparticles remarkably increase the convective heat transfer coefficient of the base fluid, and the nanofluid with 23nm particles shows higher heat transfer coefficient than nanofluids containing the other two particle sizes about 10% under the same Re. Based on the effective medium approximation and the fractal theory, the effective thermal conductivity of suspension is obtained. It is shown that if the new effective thermal conductivity correlation of the nanofluids is used in calculating the Prandtl and Nusselt numbers, the new correlation accurately reproduces the convective heat transfer behavior in tubes.

Abstract: The design and assessment of a flexure-based parallel micromanipulator with two-degrees-of-freedom (2-DOF) for automatic cell injection is presented in this paper. The design and modeling of the micromanipulator are conducted by employing compliance matrix method. The dynamic modeling and analysis via Lagrange equation are conducted to improve the bandwidth of the mechanism. Both theoretical analysis and finite element analysis (FEA) results well validate the good performance of the micromanipulator which will be applied to practical cell manipulations.

Abstract: The tensile test of NOL ring composites with different interply hybrid ratio is simulated by finite element software. The relationship between the stress of Naval Ordnance Laboratory(NOL) ring and the volume fraction of UHMWPEF is linear when the matrix suffering from the equal loading, but tower suddenly appears at the point of 56.25% which is about the critical volume fraction. The critical volume fraction of hybrid NOL ring is figured out on the basis of the constant strain model. By contrast, the results of the Finite Element Method (FEM) and constant strain model have subtle differences. Tooth contact analysis can exactly predict the stress of the interply hybrid NOL ring and the critical volume fraction of GF in interply hybrid NOL ring which has lower breaking strain than UHMWPEF does.

Abstract: The curing kinetics of the novel epoxy system for hot-melt prepreg was investigated using nonisothermal differential scanning calorimetry (DSC), and determined by Kissinger, Ozawa and Crane methods in this paper. The results showed that the value of Ti, Tp, and Tf were 446.5K, 454.7K, 491.4K, respectively. Furthermore the value of Ea1 and Ea2 determined by Kissinger and Ozawa method, respectively, were approximate, and the mean value of activation energy (Ea) is 139.31 KJ/mol. The value 0.9488 of curing reaction order n indicated that the curing reaction was complex reaction.

Abstract: Thermal conductivity prediction models of cement-based materials are inconsistent. In order to get the correct model, parallel hot wire method is used to measure the thermal conductivity of aggregate, cement paste, mortar and cement-based materials. Theoretical analysis values and experimental values of thermal conductivity of cement-based materials are compared to get the correct series-parallel model of the material. Through further research, the test results that the influence of aggregate location and aggregate size on the thermal conductivity of cement-based materials can be ignored in the case of the same aggregate content.

Abstract: This paper analyzes several methods of the present continuous nearest neighbor queries and proposes a query algorithm based on R – tree through the geometric feature of this problem, the algorithms can not only avoid the loss of dividing points and high cost of the query, but also can finish the continuous nearest neighbor query for moving objects effectively.

Abstract: Current sheet metal designing systems calculate the unfolding result automatically without the foundational information interaction with the designers, which limits the special material designing process. This paper concentrates on constructing the 3D environment for the sheet metal design, which is developed by modeling kernels technology and is favorable to construct the relationship between characteristic of material and unfolding parameters. Firstly, the developing mode is presented, by which the data structure is established. Then, the main procedure to realize the system is illustrated. The model construction is the key point. Finally, the oblique cut cylinder is unfolded as an instance to illustrate the approach. In addition, this work is the geometric foundation of the further study of sheet metal designing library.