Advanced Materials Research Vol. 795

Abstract: Membrane distillation (MD) is one of the novel separation methods used in water and wastewater treatment processes. MD is a thermal driven process which has the potential to be integrated with renewable energy source and can be operated at very low pressure. Polyvinylidene fluoride (PVDF) is a hydrophobic polymeric material which is commonly used to prepare MD membrane. In this study, surface modifying macromolecule (SMM) was added as additive into PVDF dope solution and then the hollow fiber membrane was prepared using phase inversion process. The membrane was characterized with respect to morphology and permeates flux at different temperatures. The results revealed that the PVDF membrane blended with SMM exhibited higher permeate flux than PVDF neat membrane did, mainly due to the better pore size distribution and thinner skin layer. This finding indicated the role of SMM in modifying the properties of PVDF membrane for MD process.

Abstract: This paper presents the thermal management of electronic components, microprocessor by using three dimensional numerical analysis of heat and fluid flow in computer. 3D model of microprocessors is built using GAMBIT and simulated using FLUENT software. The study was made for four microprocessors arranged in line under different types of materials, inlet velocities and package (chip) powers. The results are presented in terms of average junction temperature and thermal resistance of each package The junction temperature is been observed and it was found that the junction temperature of the microprocessors is not exceed 70o C. It also found that the (chip) powers and inlet velocities are the most important elements to control and manage the junction temperature. The strength of CFD software in handling heat transfer problems is proved to be excellent.

Abstract: In this study, we study the physical property and antibacterial bioactivity of ZnO nanopowder towards Staphylococcus Aureus. Transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), FTIR, Raman spectroscopy and UV-Vis were used to characterize the ZnO nanopowder. The major morphology consists of nanorods which have length 70-200 nm and width 30-120 nm. FTIR spectra performed a well-synthesis of ZnO that has Zn-O stretching bond (482 cm^-1). UV-Vis absorption spectra showed an intense UV absorption at 387 nm, corresponding to optical bandgap 3.24 eV. Raman spectroscopy exhibited a prominent peak in E₂^high mode located at 435 cm^-1. The antibacterial response of ZnO was performed toward Staphylococcus aureus. Higher concentration of ZnO had caused higher inhibition of the bacteria. Besides, the increment of capability of ZnO towards the bacteria was observed under UV radiation. It was believed that the irradiation had induced oxygen to be released from the surface of the ZnO and caused the increasing of reactive oxygen species, which enhance the bacteria inhibition.

Abstract: The granular activated carbons (GACs) impregnated with iron oxide containing 6-8 mass% Fe (Fe-GACs) were prepared from a commercially available GAC (BAU) and iron oxalate (BAU-OA), iron chloride (BAU-CL) and iron benzohydroxamate (BAU-HA). The impregnated BAU samples heat treated at 250°C had specific surface areas (S_BET) of 111, 50 and 4 m²/g, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample and had low crystallinity (as FeOOH and Fe₂O₃ phases) in the BAU-HA and BAU-OA samples. The BAU-OA and BAU-CL samples showed higher methylene blue (MB) adsorption capacities than the BAU-HA sample, which was corresponded to the S_BET values. The apparent MB photodegaradation rate constant (k_app) was higher in the BAU-OA sample than the other samples under the standard experimental conditions. The intensive photodegradation was found to be at pH = 3 but decreased greatly at pH>5, consistent with the presence of Fe (III)-OA complexes. Since the current process was performed without the addition of hydrogen peroxide and showed higher efficiency under solar light irradiation, this system can be used in the treatment of wastewater containing organic dyes.

Abstract: Thermal pad is new technology in the world that been used in PLCC in order to reduce junction temperature to the minimum level in electronic components. Thermal Pad was made by using nanosilver as main material. nanosilver silica films were applied on PLCC using a sol-gel process and heat-treated at different temperatures. In electronic industry, the electronic components that exceed 70oC will malfunction and damage due to the overheated. The design is used nanosilver as main material in thermo pad because it has high value of thermal conductivity and enables to dissipate heat very efficiently. The advantages of this product are enables to reduce junction temperature of PLCC 20-30%. It also had constant thickness in order to get accurate results. It was a new technology that been applied in electronic industry in order to reduce the temperature of the electronic components.

Abstract: Rapid increasing of industrialization and motorization has led arising of petroleum and energy demand. This pursue a new energy blends to cater the depletion of fossil fuel and the environmental degradation condition. Malaysia is blessed, which has suitable climate to plant alternative fuel (palm oil) and become one of the largest exporters to the world. Palm oil in its refined form as cooking oil has high energy content which can be adopted as an alternative to the petroleum based fuel. This paper evaluates the performance and emission characteristics of refined palm oil (RPO) as a fuel to the diesel engine. Palm oil and its blends composition with 20%, 40%, 60% as well as pure palm oil (100%) and diesel were tested separately under various engine loads. Five series of tests data on each type of fuel were analyzed and compared. Moreover, by increasing the percentage of RPO in blends would lead a character of higher percentage in density and viscosity. Studied revealed that the small percentage of RPO composition promises a good thermal efficiency together with the emission released.

Abstract: A study of catalytic pyrolysis on rice straw was carried out in a fixed-bed reactor. The objectives were to determine the effect of dolomite catalyst on the distribution of product yield and bio-oil characterization. The non-catalytic and catalytic process of rice straw was performed at the optimum conditions. The chemical characterization studies of uncatalysed bio-oil derived from pyrolysis of rice straw reflect a considerable amount of carbonyl and oxygenated compound, resulting in higher oxygen content in elemental composition. In the presence of the dolomite catalyst, the yield of bio-oil was markedly reduced and so was the oxygen content of the bio-oil itself. The product yields and quality of the resultant bio-oil were significantly affected by the use of dolomite catalyst.

Abstract: The paper present the three dimensional numerical analysis of heat and fluid flow through Plastic Leaded Chip Carrier (PLCC) packages in inline orientation horizontally mounted on a printed circuit board in a wind tunnel is carried out using a commercial CFD code, FLUENT^TM by using Epoxy Moulding Compound (EMC) as a main material. The study was made for four and eight packages with different Reynolds Number and package chip powers. The results are presented in term of junction temperature for four and eight PLCC package under different conditions. It is observed the chip temperatures of eight PLCC packages have higher junction temperature compare to four PLCC packages due to effect of other PLCC because of space and gap between PLCC that have more number of PLCC is smaller. Hence it makes junction temperature of eight PLCC higher compare to four PLCC packages. Moreover, the junction temperature of the packages decreases with increase in Reynolds Number.

Abstract: Friction stir welding is a solid state green welding technique. Its key benefit is to allow welding of aluminum that cannot be readily done by fusion arc welding. In this study, two pure aluminum strips of 2mm thick were friction stir welded together. For all welding pairs, three rotational speeds of 1000, 1500 and 2000 rpm were used. The traverse speed, axial force and tool geometry were kept constant. Parameters optimization based on the results of the micrographic, macrographic, microhardness and tensile strength, indicated that sound joints with the best mechanical and microstructural properties can be obtained at rotational speed of 1500 rpm and welding transverse speed of 60 mm/min. Microscopic examination and local mechanical properties analysis suggested that mechanical mixing is the major material flow mechanism in the formation of the nugget stirred zone.

Abstract: This report provides experimental data on the development of PLFP for building construction. An innovative concept was used in the design of this system and the use of lightweight foamed concrete was discussed. Preliminary result of PLFP with double shear truss connectors was analysed and presented. PLFP was tested to determine its ultimate load carrying capacity under axial loading. Ultimate load carrying capacity, load deflection profile, surface strains and crack pattern were recorded and analysed. Test results were compared with calculated values based on classical formulas that developed by previous researchers and experimental data from previous researchers on its compositeness in between wythes. Results shown that PLFP with double shear truss connectors achieved higher compositeness in between wythes and have adequate ultimate load carrying capacity.