Applied Mechanics and Materials Vols. 799-800

Abstract: The photoactive anode was fabricated by hydrothermal method using the ZnO nanorod array as the template. NiO nanoflakes were assembled on the TiO₂ tubular arrays to form p-n junction heterostrucutures on the Ni substrate. The water electrolysis was coupled with photocatalytic decomposition of water by irradiation of UV and UV-visible light on the modified Ni anode. Under UV and UV-visible light irradiation, the hydrogen evolution rates of the photoactive Ni anode modified by NiO/TiO₂ nanotube composites are 2.92 ml/h·cm² and 3.16 ml/h·cm² respectively, increased by 5.4 % and 15 % in comparison with that of the Ni anode modified by TiO₂ nanotube array and showed 152 % and 172 % improvement in comparison with that of sole Ni anode respectively.

Abstract: Using Density Function Theory (DFT), the lattice parameters of Cr doped BN sheets are optimized, which are still kept on 2D planar geometry, and the band gap and the gas sensitivity are studied. The simulation results show that the gas molecule is very easy to be absorbed by Cr doped N in BN sheet, which is more stable structure. At the same time the band gap is very easy to be tuned by adsorption the gases on the Cr doped BN sheet. The band gap decreases from 4.704eV to 0.053eV. Through adsorption energy, we find Cr substitution N on BN sheet has strong sensitivity to the gases such as N₂, O₂, CO, NO, CO₂, NO₂, H₂S, CH₂O etc. In a word, Cr doped BN sheet is a promising material in gas sensors and tuning the band gap et al.

Abstract: It is all known that the BN sheet is a nonmagnetic wide-band-gap semiconductor. Using Density Function Theory (DFT), the lattice parameters of Cr doped BN sheets were optimized, which were still kept on 2D planar geometry, and the band gap was studied. The simulation results show that the band gap is very easy to be tuned by Cr doped BN sheet, which is more stable structure. So Cr doped BN sheet is a promising material in modulating the band gap and through tuning the band gap it can be a highly efficient photocatalytic material et al. Because Cr is poisonous and harmful substance, it does harm to people’s health and environmental pollution, particularly, heavy metal contamination in soil. So Cr doped BN sheet is a promising material in modulating the band gap, through tuning the band gap it can be a highly efficient photocatalytic material and benefit humanity and protect the environment et al.

Abstract: ABS/CaCO3 nanocomposite with super toughness was processed by pressure induced flow (PIF) moulding. After PIF processing, the impact toughness of ABS/CaCO3 nanocomposite improved remarkably, the average highest Izod impact strength of nanocomposite increased to around 69 kJ/m2, which was 2.3 times higher than that of orignal ABS. Moreover, the relative toughening mechanism was investigated. The disk-like rubber domain and the cavities caused by calcium carbonate were researched by small angle X-ray scattering (SAXS). The synergy of them could prevent the craze becoming a large crack effectively.

Abstract: Dark red meranti and kapur,are two important types of wood in Malaysia were used as precursors to fabricate porous silicon carbide. A carbon template was produced by pyrolysis at 850^o C in an oxygen free atmosphere. The carbon template was further subjected to infiltration process with silicon. The infiltration process was carried out in a tube furnace in argon flow at 1500^o C with two different holding times; 2 hours and 3 hours. Thermo gravimetric analysis was done to investigate the decomposition behavior of the two species. The resulting silicon carbide was characterized by XRD. The formation of silicon carbide and also excess silicon were found. The microstructure was characterized by scanning electron microscope (SEM). An increase in holding time during infiltration increased the density as well as formation of silicon carbide (SiC). Dark red meranti precursor is likely suitable for production of silicon carbide compared to kapur due to the higher SiC

Abstract: The characterization and properties of the HKT800 carbon fiber were performed, and results showed that the tensile strength, tensile modulus and tensile elongation of HKT800 carbon fiber reached 5.6 GPa, 290 GPa and 1.9 %, respectively. The Cv value of all index was less than 3 %, and there were a few HKT800 carbon fibers belong to the cashew type. Furthermore, the surface activity of 6 K carbon fibers was higher than that of the 12 K carbon fibers after the same surface treatment. It was found that the sizing agent existed on the surface of HKT800 carbon fiber was epoxy resin.

Abstract: Biopolymer made from renewable material is one of the most important groups of polymer because of their versatility and they can be manufactured in a wide range of densities, damping and stiffness. In this project, biopolymer based from waste vegetable oil were synthesized and crosslinked with commercial polymethane polyphenyl isocyanate and doped with titanium dioxide (TiO₂) to produce renewable polymer foam (RPF).The RPF was compressed by using hot compression moulding technique at 90 °C based on the evaporation of volatile matter and is known as compressed renewable polymer (CRP). The compressive strength, compressive modulus, absorption energy, static stiffness, vibration and damping characteristic of RPF and CRP were determined. The compressive strength and compressive modulus of RPF and CRP samples steadily increased with increasing of TiO₂ loading. The highest compressive strength of RPF and CRP samples is at 10 % of TiO₂ loading of 96.43 kPa and 354.55 kPa, respectively due to the amount of filler loading. The absorption energy and static stiffness of CRB allows it to absorb more energy than RPF due to the smaller cell size and higher density. The vibration and damping characteristic of both samples were generated at displacements of 1 mm and acceleration of 0.1 G base excitation according to ASTM D3580-9. It was revealed that, the vibration transmissibility characteristic of RPF and CRP samples slightly increased and damping characteristic is vice versa with the increasing of percentages of TiO₂ loading at the frequency range of 15 - 25 Hz.

Abstract: The purpose of this study is to investigate the effect of accelerated aging cycle (AAC) on water absorption of the composites. The HDPE composite was subjected to a series of six ageing cycles at an elevated temperature. The cycle consist of immersion in water at (49 ± 2°C), explosion to steam and water vapor (93 ± 2°C), stored in freezer (-12 ± 2°C), and heated in oven (99 ± 2°C). It took approximately twelve days to complete this aging cycle. The effect and the changes of water absorption for both control and after accelerated aging were observed and determined. The results showed that water absorption was significant as the greater the fibre percentage, the higher the water absorption. This behavior occurs for both conditions. There were significant differences in the percentage of the water absorption for both control and accelerated aging cycle.

Abstract: Casing design is one of the most important parts of the well planning in the oil and gas industry. Various factors affecting the casing material needs to be considered by the drilling engineers. Wells partaking in thermal oil recovery processes undergo extreme temperature variation and this induces high thermal stresses in the casings. Therefore, forecasting the material behavior and checking for failure mechanisms becomes highly important. This paper uses Finite Element Methods to analyze the behavior two of the frequently used materials for casing - J55 and L80 steels. Modeling the casing and application of boundary conditions are performed through Ansys Workbench. Effect of steam injection pressure and temperature on the materials is presented in this work, indicating the possibilities of failure during heating cycle. The change in diameter of the casing body due to axial restriction is also presented. This paper aims to draw special attention towards the casing design in high temperature conditions of the well.

Abstract: This study provides a better understanding of the effect of density and thickness on impact strength of laminated floor panel from Kenaf high density fibreboard (KHDF). The objective of this study was therefore to determine the role of density and thickness on the impact strength of laminated floor panel. Laminated floor panels consisted of high density fibreboard (HDF) as core and decorative paper as surface layer and backing. Kenaf bast fibres were used for HDF with three different densities (850, 960 and 1000 kg/m³) with thickness of 8mm and 12mm for each panel. Energy (J) value was evaluated to determine the impact strength of all various floor panels. It was found that thickness has affected statistically on impact strength while there was no significantly difference existed on density of laminated floor panel on impact strength.