Advanced Materials Research Vols. 233-235

Abstract: The crystalline structure, morphology, and nonisothermal crystallization and melting behavior of isotactic polypropylene (iPP) with and without a novel nucleating agent containing amide group (TMC-328) were investigated with differential scanning calorimetric (DSC), polarized optical microscopy (POM) and X-ray diffraction (XRD). TMC-328 could increase the crystallization temperature and accelerate the crystallization rate of iPP. As an efficient α-form nucleating agent, the addition of TMC-328 could obviously reduce the spherulite size of iPP. There is a critical concentration of TMC-328. When the content of TMC-328 is 0.1%, iPP matrix exhibits the maximum crystallization peak temperature (123 °C) and the maximum crystallinity of 45.0%. With the content of TMC-328 increasing, crystallinity of iPP matrix decreases obviously. XRD measurements indicate that the crystal structure of the α-form of iPP is unaffected by TMC-328.

Abstract: In this paper we used sol-gel method for synthesizing Y³⁺-doped BaCeO3 solid electrolyte BaCe_1-xY_xO_3-δ(x=0.10, 0.15, 0.20, 0.25, 0.30). The samples crystallized in a single perovskite phase by X-ray diffraction analysis after sintering at 1450°C in air for 10h; Raman spectrum measurements indicated that the increasing of Y³⁺ doped content increased the crystal symmetry and increased the oxygen vacancy content for the samples, all Y³⁺ ions were doped into the Ce-sites; The electric conductivities of the samples increased with Y content and reach a maximum at x=0.25, then decreased. The relationship between proton conductivity and Y dopant was closely related with oxygen vacancy content, crystal symmetry and the forming of defect association.

Abstract: Defect of continue casting slab is closely related with technology and working conditions, one productive condition usually leads to the same type of defect. So it has a great practical significance to evaluate the operative process by effective recognition of defect types. In this paper, a damped oscillating signal is acquired by differential method. The defect type of continues casting slab is preliminary qualitative detected via three eigenvalue, the wave peak value(called WPV below), the lagging time of peak(called LTP below) and the peak value difference between the rising and failing edge(called PVD below) which extracting from the differential signal.

Abstract: The continuous annealing process of strip steel is aimed to archive the required physical and mechanical properties. During this process, strip temperature is of great importance for controlling metallurgical transformation and grain size. This paper describes the modeling of the heating process in a horizontal annealing furnace used for producing stainless steel. The steady-state model is designed to predict strip temperature in the heating section, so it can simulate the annealing process of new varieties of steel never been produces. The strip temperatures predicted by model well correspond to the field data. This confirms the correctness and accuracy of the model.

Abstract: This study aims to research and develop Pipe Flow Generators. The focus in this paper is on the rotor design for pipes of different sizes. Modern engineering tools such as Computational Fluid Dynamics (CFD) software and Rapid Prototyping technology are utilized to facilitate the numerical and experimental studies. The CFD numerical simulations consist of two and three-dimensional transient and steady analyses. These simulations were conducted to find the relationship between the flow rate, blade geometry and number of blades. During the experimentation process, Rapid Prototyping Technology (RP) was used to fabricate many different types of turbine geometries to test different impeller parameters. RPM and voltages where measured for each turbine design. The study leads to several important findings for better pipe flow generators design.

Abstract: A detailed comparison between kinetic and thermodynamic effects on grain growth in nanocrystalline Gd doped ceria ceramics was given. From the thermodynamic standpoint, the evolution of grain size with annealing time can be described using an analytical model for grain boundary segregation upon isothermal grain growth. From the kinetic standpoint, the single isothermal grain growth can be understood in terms of a single, thermally-activated rate process with constant grain boundary energy, σ_b. The solute excess in grain boundaries increases with grain growth and tends to its saturated value, therefore, the inhibition of grain growth can be attributed to the reduction of grain boundary energy σ_b through solute segregation.

Abstract: Geopolymer was prepared by Metakaolin (MK) stimulated by sodium silicate and sodium hydroxide. X-Ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize micro-structure of geopolymer and geopolymer based coating. A serial of reagents were added to modify the coating and a thermal insulation material was produced. It was revealed that MK has quasi-crystal structure and the produced geopolymers had amorphous structure. The surface of geopolymer based coating, as well as the compressive strength, adhesive strength with concrete, could be modified by adding a certain amount of silane coupling agent, mica powders and wollastonite. By mixing the asprepared geopolymer and hollow glass beads with a volume ratio of 4:1, a thermal inslation coating was produced, which had a promising application in the surface protection of hydropower dam.

Abstract: Huge storage tanks of Vinyl chloride monomer (VCM) are often regarded as major hazard installation because VCM is such a kind of flammable, explosive and toxic gas that leakage of liquid VCM would induce fire, explosion and toxic accidents. In this paper, index system of the safety of VCM storage tanks was established by analyzing four main factors including 18 indexes, based on accidents statistic and technology experience. Taking VCM storage tank in a petrochemical plant as a case, AHP-Fuzzy method was applied to achieve single VCM storage tank safety classification. The study could help companies develop preventive measures and emergency planning to reduce casualties and property losses.

Abstract: The effect of kaolin content on the cell structure of PS foam and the correlation between the cell structure and the physical properties were evaluated in this work. The kaolin as a nucleating agent did facilitate the cell nucleation. The cell structures were apparently enhanced with increasing kaolin content. In addition to facilitating nucleation, the kaolin confined the motion of chain segments of the matrix polymer, which contributed to the change in cell structure by confining cell growth and cell coalescence to some extent. The foam with smaller cell size and larger cell density absorbed more energy, hence the impact strength increased remarkably with decreasing cell size and increasing cell density.

Abstract: Tensile strain in x-direction for monolayer graphene with carbon-circles is considered based on variation principle and energy conservation. The relations between the Young’s modulus in x-direction and the number of carbon-circles of graphene are obtained. The results show that the Young’s modulus of graphene in x-direction is independent of the number of carbon-circles in x-direction, but it increases with the increasing number of carbon-circles in y-direction and finally comes to the constant.