Advanced Materials Research Vols. 383-390

Abstract: The process ,directly using desulfurization gypsum to produce gesso block in a wet environment ,is $irect to produce α-half water gesso ,directly used to gel pulverized coal , through the block automated production line to produce on the lightweight partition materials which are in large demand at the market. The complete set of technology and equipment needs less investment and saves energy .This technology integrates the two major industrial wastes to get new wall materials and change waste materials into things into things of valu.

Abstract: Channel fluorine implantation (CFI) has been successfully integrated with silicon nitride contact etch stop layer (SiN CESL) to further improve the channel hot electron stress (CHES) and constant voltage stress (CVS) reliability of n-channel metal-oxide-semiconductor field-effect-transistor with HfO2/SiON gate stack. Although the improvement of transconductance, drain current and subthreshold swing due to the fluorine passivation is screened out by the effect of uniaxial tensile strain, the result clearly demonstrates that integrating the CFI process in the SiN CESL-strained device can further suppress the CHES- and CVS-induced threshold voltage shift.

Abstract: A visible-light-driven CeVO4/TiO2 photocatalyst with nanostructured heterojunction has been successfully prepared by a simple coupled method. The catalyst was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and spin-trapping electron paramagnetic resonance (EPR). The visible light-induced photocatalytic activities were evaluated by decomposing benzene in gas phase. The result showed that the prepared catalyst exhibited efficient photocatalytic activities with high photochemical stability under visible light irradiation.

Abstract: A visible-light-responsive TiO_2-xN_x photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO_2-xN_x photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO_2-xN_x photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.

Abstract: Magnesium stands for a very attractive material for biodegradable stents because of its natural process and its steady disintegration into the human body by a corrosion process. The objective of the present work is to investigate the effect of the thickness on mechanical properties of the magnesium stent design. A nonlinear transient finite element simulation has been performed to analyze the influence of various thicknesses (from 50µm to 110µm with the increment of 30µm) on the behavior of a magnesium coronary stent. The model was constrained symmetrically to ensure that any virtual rigid movement does not occur during the process of coronary stent expansion. The transient load is applied in three steps in the inner surface of the stent. Four mechanical properties are studied by mathematical modeling with determination of: (1) stent deployment pressure; (2) the intrinsic elastic recoil of the material used; (3) the stent longitudinal recoil; (4) and the stress maps. The results indicate the potential application of magnesium stent and the effect of the thickness on the behavior of magnesium stent design and material.

Abstract: This study focuses on inorganic gas barrier material in the advanced process techniques of solar cell devices for planarization properties and sublimate defect reduction. The inorganic gas barrier material have been optimized and studied for excellent surface planarization property. The newest approach by excellent collaborations from both process and material has the planarization property on an irregular substrate such as the patterned steps, via and trenches to increase the depth of focus and pattering resolution. A remarkable reduction in via topography with 0.6 μm as a depth and 0.13 μm as a diameter has been achieved excellent thickness bias less than 50 nm in 220 nm blanket field thickness. In addition, the sublimate amount of the film obtained from the developed inorganic gas barrier material was low as compared with that of the film obtained from the referenced organic non-gas barrier material.

Abstract: In this article, parametric optimization for material removal rate (MRR) and surface roughness (SR) study on the powder mixed electrical discharge machining (PMEDM) of EN-8 steel has been carried out. Response surface methodology (RSM) has been used to plan and analyze the experiments. Average current, duty cycle, diameter of electrode and concentration of micro-nickel powder added into dielectric fluid of EDM were chosen as process parameters to study the PMEDM performance in terms of MRR and SR. Experiments have been performed on newly designed experimental setup developed in laboratory. Most important parameters affecting selected performance measures have been identified and effects of their variations have been observed.

Abstract: The influence of forming process on mechanical properties and microstructure of high strength microalloyed steel has been studied in this research. All samples selected from 90º and 180º of pipes in transverse and longitudinal orientations after UOE forming. The steel was supplied as a hot rolled plate with accelerated cooling. Microstructure of the micro alloy steel was various combinations of acicular ferrite, granular ferrite and M/A phases. Charpy impact fracture toughness tests were carried out in -50 °C to 0 °C. Minimum and maximum yield strength appears in the 180º and 90º of pipe in longitudinal and transverse orientations respectively. Increasing in the yield strength related to minimum amount was about 5.8 % after UOE forming. Comparison between yield strength after and before forming appears increased about 6.9 % due to forming. With decreasing in the test temperature from -50 °C to 0 °C, fracture energy decrease up to 0.9 % that it’s very little and relinquishment. However for samples that fractured in the temperature of -50 °C difference between highest and lowest energy was about 5.9 %. Charpy test results appear that fine M/A phase not a major factor on decrease of upper shelf energy, if homogenize distributed in the acicular ferrite matrix.

Abstract: The dynamic stability behavior of laminated composite shells subjected to hygrothermal loadings are studied in the present investigation. A simple laminated model is developed for the vibration and stability analysis of laminated composite shells subjected to hygrothermal conditions. A computer program based on FEM in MATLAB environment is developed to perform all necessary computations. An eight-node isoparametric element is employed in the present The analysis with five degrees of freedom per node. Element elastic stiffness matrices, mass matrices, geometric stiffness matrix due to mechanical and hygrothermal loads and load vectors are derived using the principle of minimum potential energy. Quantitative results are presented to show the effects of curvature, ply-orientation, degrees of orthotropy and static load factors of laminate on dynamic stability of composite shells for different temperatures and moisture concentrations.

Abstract: Dissimilar joints of Monel 400 and AISI 304 are used widely in marine and offshore environments for the fabrication of heat exchangers, evaporators, piping and vessels as well as in the chemical, petrochemical, and power generation industries. An attempt was made to weld Monel 400 and AISI 304 by gas tungsten arc welding using ENiCu-7 and E309L filler wires. A comparative analysis was carried out on these weldments so as to examine the weldability, mechanical and metallurgical properties of the weldment. In addition, corrosion behavior of these weldments has been carried out on the dissimilar weldments in K₂SO₄ + NaCl (60%) molten salt environment at 600°C under cyclic conditions. The oxide scales formed on the various zones of the weldment have been characterized systematically using surface analytical techniques. Weld zone was found to be more susceptible to degradation than in base metals.