Advanced Materials Research Vols. 160-162

Abstract: In order to study the mechanical performance of Reactive Powder Concrete (RPC) used for structure engineering, 38 series of RPC specimens are fabricated, cured, tested and analyzed. There are 5 sets of specimens are fabricated for each actual site structure engineering. The compressive strength, flexural strength and elastic modulus are tested according to the specimens and the compressive strength is tested with different age time. All the specimens are steam cured with the same situation as the structure. According to the test result, the compressive strength of RPC is up to 80MPa 3days after it is cast and the compressive strength is higher than 120MPa 15days later. The average flexural strength of RPC is 19.4MPa and the elastic modulus is 45.15GPa. The tested results show that the mechanical performance of RPC can satisfy the engineering requirement. The mixing proportion and the curing system can be used for engineering design and construction.

Abstract: Nonlinear bending problem of FGM cantilever beam under distributed load are discussed in this paper. Based on the large deformation theory and considering the axial extension of the beam, the equilibrium equations with geometric nonlinearity of a FGM beam subjected to distributed load are established. They consist of a boundary value problem of ordinary differential equations with strong non-linearity, in which seven unknown functions are included and the arc length of the deformed axis is considered as one of the basic unknown functions. By using shooting method and analytical continuation, the nonlinear boundary-value problem is numerically solved as well as the non-linear bending characteristic curves of the deformed beam versus the load are presented.

Abstract: This paper presents an experimental investigation of the heat transfer characteristics of the heat pipe with CuO-water nanofluid. For this purpose, CuO nanoparticles of 30 nm size were dispersed in distilled water to form stable suspension containing 0.1% ~ 2.0% mass concentrations of nanoparticles, and then the heat pipe was produced after CuO-water nanofluid was added in it as the working fluid. Experimental results show that the use of CuO-water nanofluid hold a lower start-up temperature and shorter start-up time for the evaporation section of the heat pipe compared to distilled water. Their heat transfer performance of the evaporation section and condenser section has been improved than that of distilled water. The heat transfer coefficient of nanofluid is higher than that of the base liquid and found to increase by 29.4% and 125.0% for the mass concentration of 0.5% compared with the heat pipe using distilled water while the input power ranging from 15W to 45W. By examining the thermal resistance, it was found that the thermal resistance has been significantly decreased compared with the heat pipe with distilled water. The thermal resistance of heat pipe using CuO-water nanofluid at a mass concentration of 0.5% is 0.36K/W when the input power is 45W, while the thermal resistance of heat pipe using distilled water is 0.80K/W. Further analysis indicates that the heat pipe using CuO-water nanofluid at 1.0% mass concentrations has the best heat transfer performance.

Abstract: Spinel compound LiNi0.4Mn1.5Cr0.1O4 was synthesized at different reaction temperature. The optimum temperature was 900 0C. The product exhibited good electrochemical properties. It delivered capacity of 128.2, 124.1 and 116.8 mAh g-1 at 0.2, 0.5 and 1C, respectively. The capacity retention was 98%, 99% and 99% after 30 cycles, respectively. The electrochemical property of compound LiNi0.4Mn1.5Cr0.1O4 was better than that of LiNi0.5Mn1.5O4.

Abstract: From the use of renewable resources and environmental protection, recycling of waste printed circuit boards (PCBs) receives wide concerns as the amounts of scrap PCBs increases dramatically. However, the recycle technology for waste PCBs in China is still immature. Previous studies focused on metals recovery, but resource utilization for nonmetallic fractions (NMFs) is relatively fewer. In this paper, the physical properties of the recovered nonmetallic powder is briefly introduced. The preparation of composites including organic and inorganic composites through the recycling NMFs was reviewed. In addition, the research directions of preparation of composites based on recycling NMFs were put forward. Firstly, the study on the reaction mechanism of composites preparation should be strengthened to explore the reasons why the additional quantity and particle size of NMFs powder have effects on the properties of composites. Secondly, a suitable coupling agent should be chosen to improve the the interface compatibility between the NMFs and matrix.

Abstract: Fluorination of the zeolite has been known as a useful method to modify its acidity and surface performance. In this paper, a set of zeolite Hβ were impregnated with aqueous solution of NH4F. The effects of NH4F impregnation on the structure and acidity of Hβ was investigated by XRD, BET measurements, NH3-TPD, and Py-IR. The change of specific surface area and pore volume of the fluorinated samples with NH4F can be attributed the reaction of NH4F with non-framework and framework aluminum. The fluorination increases the strength and changes the distribution of the acid sites; the fluorination also leads to the decrease of the total acid sites and the Brönsted acid sites due to the dealuminization of the samples and the substitution of the OH- by fluorine atoms.

Abstract: A new kind of dendritic-salicylaldehydeimine ligand was synthesized with 1.0G polyamidoamine and salicylaldehyde through schiff reaction, and further formed two kinds of dendritic metal complexes by complexing Cu and Zn. The dendritic-salicylaldehydeimine ligand and its metal complexes were characterized by elemental analysis, IR, NMR and UV. The results indicate that two kinds of dendritic metal complexes with stable structure have been synthesized by complexing Cu and Zn, the yield were 88.2% and 65.2% respectively; Intra-molecular hydrogen bond between the hydroxyl H atom of ph-OH and the N atom of >C=N- has been formed in the ligand; The structures of complexes agree well with the theory.

Abstract: Roller quench is a rapid cooling technique used in strip continuous heat-treatment process, which is one of the most important processes in producing cold-rolled strip steel. Heat transports by contact heat transfer in roller quench, for the complex characteristics of contact heat transfer, roller quench is very difficulty to simulate. In this paper a roller quench heat transfer model is build based on Fourier-Kirchhoff differential equations. A new correlation function of contact conductance is developed from statistical mechanics model results by least square method. This correlation function solves the heat transfer boundary condition in contact region between strip and roller. In this model the contact radiation is also considered. The roller quench model predicts the heat transfer characteristics of roller quench. The model is useful for the designing and controlling of the roller quench system.

Abstract: Through a series of Piezocone Penetration Test (CPTU) model tests with saturated clay soil, excess pore pressure produced by CPTU penetrating and dissipating has been measured by CPTU probe and pore pressure mini-transducers, the variation rules of excess pore pressure has been analyzed, the results show that at the same transducers layer, the value of initial excess pore pressure at the probe is biggest, and with the horizontal distance from probe increasing, the value of initial excess pore pressure measured by transducers around the probe has been decreased quickly; at the same dissipating process, the value of initial excess pore pressure measured by transducers locating in the same horizontal plane with probe is bigger than the value by transducers of the other layer; difference between the variation rule of excess pore pressure dissipation measured by CPTU probe and pore pressure mini-transducers is that after the value of excess pore pressure is maximum, with the dissipating time increasing, the value of excess pore pressure measured by probe decreased rapidly, but at first the value of excess pore pressure measured by transducers decreased slowly and then after a short time decreased rapidly; the time of 90% of the maximum of excess pore pressure dissipating measured by CPTU probe is longer than the time of 90% of the maximum of excess pore pressure dissipating measured by transducers; at the same transducers layer, with horizontal distance from the probe increasing, the time of 90% of the maximum of excess pore pressure dissipating decreased. The achieved result can provide a foundation for further study for CPTU mechanism.

Abstract: The utilization of stay in place formwork in concrete structure has received considerable attention in recent years. It is comparatively low labor intensity, readily available and has a range of attractive properties and characteristics that makes it suitable for a variety of building and construction applications. The fabrication and seismic behavior was studied in this paper. The experiments have shown that sufficient data have been obtained to give confidence in the reinforcing mechanism of stay in place construction formwork, and future work need only be focused on formwork design and standardization.