Applied Mechanics and Materials Vols. 465-466

Abstract: Biodiesel is an alternative fuel derived from varies sources of vegetable oils, animal fat, or waste frying oil to give the corresponding fatty acid methyl ester. The properties of alternative fuel of CPO biodiesel and SVO biodiesel have been investigated at different temperature. The biodiesel was blended up palm oil blending ratio from 515vol% (B5B15) and straight vegetable oil ratio from 515vol% (S5S15). The properties were tested at 27.5°C, 40°C, 50°C and 60°C with observed the changes of the density, kinematic viscosity, flash point, water contents, and acid value. In this study, properties of CPO biodiesel were found to have a higher value and diesel fuel under all ambient temperature. Under all ambient temperature, preheating CPO fuel increased value of density, kinematic viscosity, water contents, and acid value than SVO biodiesel.

Abstract: The effects of calcination factors on the La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ-SDCC (LSCF-SDCC) composite cathodes powder were investigated. LSCF-SDCC has been prepared using high energy ball milling technique via dry milling method. The resultant LSCF-SDCC composite cathodes powder then were calcined at 700, 750 and 800 °C with soaking time of 1, 2 and 3 hours. The findings reveal that different calcinations temperature and soaking time gives effects to the composite cathodes powder. Clear peak intensity demonstrate from calcination temperature 750 °C as confirm via XRD analysis indicates that crystalline structure has been improved. FESEM investigation demonstrate the presence of large particles in the resultant powder resulting from the increased calcination temperature and soaking time. LSCF-SDCC composite cathodes powder calcined at a temperature of 750oC for soaking time 1, 2 and 3 hours demonstrates good crystallite structure to be served as composite cathode SOFCs compared to samples calcined at 700oC and 800oC with soaking time 1, 2 and 3 hours.

Abstract: This paper presents a state of the art design of a stand-alone photovoltaic (PV) system to provide the required electrical power for a single refrigeration system at Kuala Terengganu, Malaysia. The simulation result shows a total of 1849.7 kW/m2/year horizontal global irradiation available at Kuala Terengganu. After considering losses such as IAM factor, model array miss match etc, the final energy available to the consumer is 5,256 (kWh/year). The energy requirement of the refrigerator system is 83.3% of the energy available.

Abstract: The aim of this project is to transfer knowledge on production of biodiesel from waste cooking oil then the biodiesel is used as a fuel to fire the burner of frying pan for crackers. The project was initially an experimental work of processing the waste cooking oil into biodiesel in the laboratory. The pilot project was built through this knowledge transfer program with the participation of a small local fabricator in Batu Pahat. This continuous biodiesel plant produces a biodiesel for the chip cracker factory. The biodiesel was blended with diesel oil to get B5 and B10 grade biodiesel. The application of this biodiesel has enabled the company to use its waste cooking oil without having to dispose it and this has save cost to the company. The other advantage is that it has significantly help to preserve environment and encourage green practice. The biodiesel plant has also motivated the company towards thinking about environment and also alternative energy thus sustaining its operation. The project benefits both the university and the industry

Abstract: To maximize and improve utilization of solar collector system, there is need to integrate the system with thermal energy storage (TES), this will increase the over all efficiency of the system and provide continuous supply of energy day and night. The performance of the TES depends on its thermal conductivity and this can be enhanced by introducing nanoparticles. Thus, this paper focus on the thermal conductivity enhancement of Cu and Fe nanoparticles dispersed in paraffin based suspension was investigated experimentally for utilization in solar collector integrated with TES. The enhanced thermal conductivity measurement was performed by transient hot disk sensor technique. The increment in thermal conductivity showed approximately linear progression with increase in percentage of mass concentration of the dispersed metal-nanoparticles. It was observed that the nanoparticle with lower thermal conductivity value (Fe-80 W/mK) at bulk enhanced the polymer matrix higher than the nanoparticle with higher thermal conductivity value (Cu-401 W/mK) at the bulk. The Cu and Fe nanoparticles, at mixing ratio of 1.5% by mass, increased the thermal conductivity of the paraffin based nanocomposites by 20.63% and 51.95%, respectively when compared with the pure paraffin. The experimentally measured thermal conductivities of the Cu and Fe-paraffin nanocomposites were compared with some models and it was observed that they were under predicted. The thermal diffusivity and specific heat showed irregular increase and decrease with varying percentage mass concentration of the nanoparticles. The enhanced nanocomposite will be utilized as heat transfer medium in a solar collector system integrated with TES.

Abstract: Turbine blade cooling is crucial in order to maintain its temperature below melting point. Integrated impingement cooling (IIC) is one method to achieve this. Present study deals with 3-dimensional transient numerical simulations of the IIC structure for high performance turbine. Cooling performance of four newly proposed IIC configurations along with two configurations by Funazaki and Hamidon (2008) have been investigated using k-ε turbulence model via commercial CFD package, Ansys Fluent. The simulations were validated against the experimental data of Funazaki and Hamidon (2008) and good agreement between the numerical results and the experimental data was observed. Pin configuration of STAG1 and STAG3 gave the highest heat transfer coefficient at the target plate and pin surfaces respectively. Evidently, conductive pin that acts as fin can improve the overall heat transfer of the IIC system studied.

Abstract: Emulsified biodiesel are often stabilized using a combination ratio water, biodiesel and surfactant in achieving stable emulsions. The objective of this study was to evaluate the long-term stability of three phase oil-in-water-in-oil (O/W/O) with respect to the water content and Tween 80. Biodiesel emulsions containing 5 mL, 10 mL and 15 mL water were produce with combination of 95 mL, 90 mL and 85 mL B20 (80 % diesel + 20 % biodiesel) and surfactant by using a mechanical stirrer machine. The experimental results show that increasing concentration of Tween 80 more than 1.5g gave destructive effect on water in oil emulsion stability. In addition, lowering concentration of water content contribute to low polydispersity of emulsion which produced the high emulsification stability.

Abstract: . La_0.8Sr_0.2Ga_0.8Mg_0.2O_2.8 (LSGM) acts as a promising electrolyte material for solid oxide fuel cell (SOFC) at intermediate temperature although its single phase synthesis is comparably difficult. However, phase purity is influenced by the amount and type of the transition metals doped and with the addition of transition metals both bulk and grain boundary conductivities are increased. In this work, Co is doped at Ga site of LSGM by Pechini method. The powders are then calcined, sintered and subsequently characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo-mechanical (TMA), nanoindentation test and impedance analysis. As observed from XRD single phase La_0.8Sr_0.2Ga_0.8Mg_0.15 Co_0.05O_2.8 (LSGMC) is found at 1400°C and getting its single phase is easier than synthesizing single phase LSGM. As found from Rietveld analysis, the synthesized LSGMC is having orthorhombic crystal structure with Pbnm space group. TEM images show the spherical particles with size ~35 nm. Density of the sintered pellet as measured by Archimedes principle is found to be 98% at 1400°C, 8h. Thermal expansion co-efficient of the sintered pellet is found to be 12.2 ×10^-6/°C, which is nearly same as of LSGM and nearly matches with other SOFC components. Hardness and Youngs modulus of the material as found from the Nanoindentation test are found as 13.14 ±0.9 GPa and 204.5±5.7 GPa respectively, which are suitable for SOFC application. The diffused semicircle observed in Nyquist plot simulated as (RQ)(RQ) circuit and the ionic conductivity is found to be higher than LSGM at equivalent temperature.

Abstract: This research investigated the physical properties of Jatropha oil to determine its viability as a clean and renewable source of lubricant oil. The study was performed using a four-ball tribotester, CCD camera, digital microscope and viscosity meter. The experiment was conducted using different temperatures (55, 75 and 105°C). The experiment was conducted of constant parameters as speed; load and time under the American Society for Testing and Materials (ASTM), number D 4172.The data included the evaluation of anti-wear, anti-friction and viscosity of Jatropha oil. To evaluate lubricant ability all results of this research were compared to findings regarding hydraulic oil as a mineral oil-based lubricant. The results showed that, under various temperatures Jatropha oil had better lubricant ability compared to hydraulic mineral oil.

Abstract: In this study, a dynamic behavior of a two bed adsorption chiller has been analyzed using highly porous activated carbon of type Maxsorb III as adsorbent and hydrofluoro olefin [R1234ze (E)] as refrigerant. R1234ze (E) has a low global warming potential (GWP) and zero ozone depletion potential (ODP). A parametric study has been presented where the effects of adsorption/desorption cycle time, cooling water inlet temperature and regeneration temperature on the performance are reported in terms of cooling capacity and coefficient of performance (COP). This chiller can be driven by the waste heat of internal combustion engine and hence it is applicable in automobile air conditioning.