Abstract: In this paper, proton conducting composite membranes of Nafion®-mordenite for direct methanol fuel cell (DMFC) were prepared using solution casting method. Mordenite, used as inorganic filler, was incorporated into Nafion polymer in order to improve membrane properties for DMFC application. Effect of solution casting temperature on resulting composite membranes was focused. The temperature of the membrane preparation was varied from 80 to 120°C. Properties and morphology of the resulting membranes including solubility, water uptake, ion – exchange capacity were investigated and reported. It was found that composite membrane prepared at 100°C gave the most alcohol resistance and mechanical stability membrane with 0.59% soluble. Furthermore, it gave highest ion – exchange capacity, 0.10 meq⋅g-1, which is 33% and 98% higher than the membranes prepared at 80°C and 120°C respectively.
Abstract: This work deals with studying the mechanical properties specially fatigue behavior for high performance composite materials of poly ether ether ketone (PEEK)/glass fiber, which are used in Aircraft Industry. Two materials have been used: (PEEK natural) and (PEEK+30% glass fiber).To identify the type of (PEEK), infrared (FTIR) test has been conducted. X-ray test has been used to measure the (PEEK) crystalline ,also the tensile properties, impact strength and the fatigue test are performed.The results show that FTIR test peaks are for standard PEEK polymer and that GFRP increases the crystalline of (PEEK) material , while the tensile , impact and fatigue properties of (PEEK) decreases by adding GF to PEEK .
Abstract: Through introduction of the principle and characteristics of electron beam machining technology, the application status and application instance of electron beam in research of materials science and materials processing in recent years were introduced in detail. The research situation of the previous various electron beam machining methods and applications was discussed, and the various research results were analyzed, thus concluded that the emphasis and advantages of the electron beam machining technology in the application of various materials.
Abstract: The combination of atomization and smelting fabricated high strength Al-6Zn-2Mg-2Cu alloy. Microstructure was observed and analyzed by optical microscopy and SEM. The alloy featured with refined grains and even distribution. After being solution treated at 475°C for 1.5h, following multi-pass rolling with total reduction of 33% and aging at 120°C for 40h, the yield strength was 592MPa, peak stress of 597MPa and elongation of 12.2%.
Abstract: The effects of B2O3 additive on the microstructures, the phase formation and the microwave dielectric properties of MgTiO3–CaTiO3 ceramics were investigated. The sintering temperature of B2O3-doped 0.95MgTiO3–0.05CaTiO3 ceramics can be lowered to due to the liquid phase effect. Formation of second phase MgTi2O5 can be effectively restrained through the addition of B2O3. The microwave dielectric properties are found strongly correlated with the sintering temperature as well as the amount of B2O3 addition. At , 0.95MgTiO3–0.05CaTiO3 ceramics with 10 wt% B2O3 addition possesses a dielectric constant of 18.3, a Q×f value of 20,000 (at 7 GHz) and a value of −6.12 ppm/. In comparison with pure 0.95MgTiO3–0.05CaTiO3 ceramics, the doped sample shows not only a 22% loss reduction but also a lower sintering temperature. That makes it a very promising material to replace the present one for GPS patch antennas.
Abstract: In this study, an investigation was conducted to develop oil palm fiber from palm oil mill waste as a thermal insulator. The experimental study focused on comparisons of thermal conductivity and temperature gradient or difference between the existing commercial rockwool and the produced oil palm fiber as a thermal insulator for a chimney of steam packaged boiler. The experiments were conducted at different temperature ranges and packing density. The values of the measured thermal conductivity were found to be 0.02 W/m·K to 0.112 W/m·K for a packing density of 78, 96 and 112 kg/m3, and at a temperatures between 40 oC to 90 oC. The value of the thermal conductivity of the oil palm fiber showed an increase at higher temperatures and greater temperature gradient as compared to the rockwool insulator. Although not being able to match the values at higher temperatures and temperature difference, other factors such as the cost and the environmental benefits of using oil palm waste material should be taken into consideration and hence encouraging its use as at least a supplement to existing insulation materials.
Abstract: In order to improve the coke residue of phenolic resins (PF), different solvents were used in the present work. The research indicates that in comparison with other solvents, such as ethylene glycol (EG) and ethyl silicate (ES), furfural (FF) can enhance crosslinking density and increase residual coke yield of phenolic resins (PF). The results demonstrate that the residual coke yield of PF with furfural is 68 % higher than that with other solvents. In addition, pyrolysis peak temperature of PF with furfural is relatively high and pyrolysis process is more smoothly. FTIR results show that new bonds formed in PF when take furfural as solvent, and furfural changed the structure of phenolic resins. Raman spectra analysis results show that the order degree of the carbonized products (treated at 800 °C) is higher than that in other solvents, and stability of the carbonized products is improved. The research concludes that the type of solvent has great influence on the structure and coke residue.
Abstract: This work aimed to use durian peel as raw material for producing bio-briquette charcoal by combustion and gasification. Briquette charcoal obtained was proposed as an alternative thermal energy for household. The producing process began from washing, drying and then pyrolyzing under carbonization by the designed drum dryer furnace. The pyrolyzed durian peels were crushed and grinded before densified in the designed extrusion briquette producing unit using tapioca starch as a binder. Durian peel briquette charcoals were mixed with starch binder in three different mass ratios of 70:30, 72.5:27.5 and 75:25. The results presented that the density of briquette charcoal was between 0.25 and 0.27 g cm-3. The heating value appeared to be decreased with an increase of the starch binder. Briquette charcoal from the ratio of 75:25 gave the maximum heating value of about 24,382 J g-1, which was approximately 81% of commercial coconut shell briquette charcoal. Fire combustion test showed that the combustion times of the durian peel briquette charcoals were between 2.3 and 2.4 h, which were slightly lower than value of the commercial briquette charcoal (2.85 h).
Abstract: The problem of urban soil pollution has become increasingly prominent. Finding out the source of contamination of the replaced soil, analyzing the potential threat of contaminated soil to human health and ecological environment are the focus and the premise of the urban land replacement work. This paper selected typical region in eastern coast of Jiaozhou Bay, and research of replaced soil was carried out from the analysis of heavy metals pollution and ecological risk assessment. The results show that in the study site the quality of soil environment is poor, and there is a certain degree of heavy metals pollution; Pb,Ni and Cu are the main contribution factors of the ecological risk.