Advanced Materials Research Vol. 740

Abstract: The title compounds 2-alkylamino/alkoxy-3-arylthieno [3,2-pyrimidin-4(3H)-ones were synthesized by base catalytic reactions of primary amines or alcohols with carbodiimides,which were obtained from the aza-wittig reaction of iminophosphorane 2 and arylisocyanates.The conditions of cyclization and spectral properties were researched.

Abstract: TiO₂ films were prepared on the AZ31 Mg alloy substrate by sol-gel method. The morphology was characterized via X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy disperses spectroscopy (EDS). The corrosion rate of the coated AZ31 mg alloy was tested with the method of orthogonal experiment design. The influence of the hydrolysis temperature, coating times, calcinations temperature and time was investigated.

Abstract: Influence of Mn²⁺, Mg²⁺ and Ca²⁺ on β-D-glucosidase activity produced by Xanthophyllomyces dendrorhous was measured. The presence of Mn²⁺ could increase the β-D-glucosidase activity and the change in cell morphology of obviously improves the cell growth and the astaxanthin biosynthesis. The cell biomass, the astaxanthin yield and the astaxanthin content in dry cell was reached to 3.65 g L^-1, 3.06 mg L^-1 and 0.84 mg g^-1 at 72 h of fermentation respectively, which were higher than those in absence of Mn²⁺.

Abstract: Self-assembling of 1O4Cd identical tetrahedral clusters resulting to nanoscale order in ZnTe:(Cd, O) is presented. Such co-doping transforms ZnTe into Cd_xZn_1-xO_yTe_1-y alloy. The decrease of the strain energy is a cause of this phenomenon. The self-assembling conditions are obtained by the minimum condition of the free energy of ZnTe:(Cd, O) at the Cd and oxygen in the dilute and ultra dilute limits, respectively. An occurrence of 1O4Cd clusters and completion of self-assembling (all oxygen atoms are in clusters) are results of the continuous phase transitions. The temperature of the occurrence of self-assembling does not depend on the oxygen content and it is a function of Cd concentration only. Cd_xZn_1-xO_yTe_1-y with all oxygen atoms in clusters may be obtained in temperature ranges from T = 270 °C (x = 0.002, y = 1×10^-4) to T = 620 °C (x = 0.02, y = 1×10^-4) and from T = 240 °C (x = 0.005, y = 0.001) to T = 580 °C (x = 0.02, y = 0.001).

Abstract: This paper proposed a study on solid insulator that can withstands the high electrical field stress. In order to clarify how the solid insulator can withstands the high electrical field stress, an Araldite epoxy resin with specific amount of nanoAluminum Oxide (Al2O3) filler have been chosen for the experiments. The influence of nanoAluminum Oxide (Al2O3) filler on the electrical tree propagation has been investigated. The electrodes of point-plane geometry were impregnated into the sample and tested under high voltage AC. The level of applied voltage was 12 kV (AC), 50 Hz. The results of experiment showed that the specific ratio of nanoAl2O3 (0.1 wt% to 0.3 wt%) filler can inhibit the growth of the electrical tree as well as it can withstands the high electrical field stress.

Abstract: Nafion based IPMC (Ion Polymeric Metal Composites) has been prepared by using a tetraaquaplatinum (II) complex, [Pt (H₂O)₄])ClO₄)₂. Fabrication of a robotic mini-hand comprising five micro-fingers of 5 mm length, 400 μm width at a pitch of 600 μm has been achieved by adopting mechanical micro milling' technique. The micro-fingers prepared from the IPMC material were found to actuate successfully under operating voltage of 2.5 V.

Abstract: Under voltage of 220V, this article has carried out ignition test of three categories of combustible substance including polyurethane foam, cotton cloth and newspaper by simulation of short-circuit fault of aluminum conducting wire, so as to get the characteristic parameters of ignition of combustible substance due to short-circuit bead at different heights, summarize the distribution of fire origins for ignition of polyurethane foam due to short-circuit bead at different heights, and provide detailed fundamental data and effective technical support to fire disaster researchers of primary-level fire protection during onsite investigation.

Abstract: Polymer recycling has received a great deal of attention in recent years. At the present time, small percentages of polymer wastes in Malaysia are being recycled. The recycling process has typically consisted of reprocessing the waste material to make other polymeric products or energy recovery from complete combustion. Thus, the development of concrete using non-conventional aggregates, such as polymer waste (especially polystyrene), ceramic waste, or other wastes, has been investigated to determine the comparative properties of the various concretes and the comparative costs. This paper the results of an experimental study in which the coarse aggregates used in conventional concrete were replaced by polystyrene waste aggregate to produce a lightweight material. The proportions of the mixtures were varied to determine the water-cement ratio and the content of polystyrene waste aggregates that provide the best results. The properties of the aggregates were also compared. Strength tests were conducted after the experimental concrete was cured for 28 days, and the experimental results indicated that the strength of the concrete made with polystryene waste aggregate ranged from 14 to 17 MPa. In addition, the density of these concretes ranged between 1467 to 1560 kg/m³, which means that they would be categorized as lightweight concretes. The results also indicated that the workability of the polystyrene waste aggregate concretes was good, and the strength characteristics were comparable to those of conventional concrete.

Abstract: Foxtail grass, also known as rumput bulu by the local people, is one of the fast growing grasses abundantly available all over Malaysia. A full grown Foxtail grass attains a height of about 0.5 1.5 meters. The fibres were prepared by mechanical grinding procedure and the fibre size and length produced can be controlled through the grinding time of this grass material. The weight loss of the different grinding time was calculated. The polymer composites panel were then made from the mixing the polystyrene with various size of fibre produced. Flexural test exhibited good and comparable strength properties. The results show that this grass fibre may be considered as one of the potential sources of natural/ agro fibres for polymer composites panel.

Abstract: In this test, PVC insulated wire is connected to self-made large current generator, so that different high-multiple overload currents (3Ie, 3.5Ie, 4Ie, 4.5Ie and 5Ie) passes through, with the increase of overload time, observe the change of insulation material of wire and ignition situations of different combustible substance (paper scrap, absorbent cotton and fire-retardant pipe). The results show that the higher the overload multiple, the larger the ignition capability of wire to combustible substance; even though it takes short time for fire-retardant pipe to smolder, but it takes longer time for fire-retardant pipe to become burned black and fail, and both cases are free from ignition, therefore, in case there is no collapse or burn-through, a certain degree of fire retardation is available in fire-retardant pipe in comparison with other two combustible substances.