http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Polymer Matrix Templated Synthesis: Manganese Zinc Ferrite Nanoparticles Preparation
Siti Hajar Mohd Noor,Bee Chin Ang,Iskandar Idris Yaacob 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.
Nanoparticles of MnxZn1-xFe2O4 where x = 0, 0.4, 0.5 and 0.6 were prepared by polymer matrix templated synthesis method. This technique utilized synthetic ion exchange resin as a host for precipitation of nanoparticles. Mn2+, Zn2+ and Fe3+ were adsorbed into the matrix of the resin from an aqueous solution mixture of respective chlorides. The resin beads were then recovered washed and dried. Follow by an excess amount of NaOH solution added to the resin that contained Mn2+, Zn2+ and Fe3+. The system was then heated to 85oC to transform the precipitated precursors into magnetic oxide. The morphology and shape of the particles were observed by transmission electron microscopy. The particles were almost spherical in shape and were about 6 - 9 nm in diameter. X-ray diffraction patterns showed broad peaks indicating that the crystallite sizes were in sub-micron dimension. The crystallite sizes for these particles increased with increasing Mn content. Magnetic property measurements were carried out using an alternating gradient magnetometer. The magnetization curves passed through the origin and showed no hysteresis indicating that the particles were superparamagnetic.
Siti Sofiyah Skh Ali,Bee Chin Ang,Serene Teh Seoh Hian 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.
Transfer molding is the most effective method for molding encapsulation for semiconductor packaging due to low maintenance costand high production yield. Wire sweep is a critical moldability issue as excessive wire sweep will contact neighbouring wires, causingelectrical short that consequently leads to electrical failure of the package. Wire sweep characterization was carried out with variouswire locations, mold flow directions, wire lengths, wire pitches and wire angles on Low Quad Flat Packages (LQFP). JMP statisticalanalysis was performed to determine the significant factors and correlations of wire sweep performance. It was found that wire lengthhas the most significant correlation with wire sweep percentage. The four wires, two at the bottom-left and top-right (and hencedesignated as corner 2 and 4, respectively) exhibited the worst wire sweep when the mold gate was located at the top-left corner ofthe package. The wire sweep performance of seven wire layouts with varying wire lengths were also investigated. The results haverevealed and proven that the two wires (corner 2 and 4, respectively) exhibited a higher wire sweep percentage. Overall, it was foundthat wire X4 has the highest wire sweep deflection.
Adsorption capability of activated carbon synthesized from coconut shell
Md Shariful Islam,Bee Chin Ang,Samira Gharehkhani,Amalina Binti Muhammad Afifi 한국탄소학회 2016 Carbon Letters Vol.20 No.-
Activated carbon was synthesized from coconut shells. The Brunauer, Emmett and Teller surface area of the synthesized activated carbon was found to be 1640 m2/g with a pore volume of 1.032 cm3/g. The average pore diameter of the activated carbon was found to be 2.52 nm. By applying the size-strain plot method to the X-ray diffraction data, the crystallite size and the crystal strain was determined to be 42.46 nm and 0.000489897, respectively, which indicate a perfect crystallite structure. The field emission scanning electron microscopy image showed the presence of well-developed pores on the surface of the activated carbon. The presence of important functional groups was shown by the Fourier transform infrared spectroscopy spectrum. The adsorption of methyl orange onto the activated carbon reached 100% after 12 min. Kinetic analysis indicated that the adsorption of methyl orange solution by the activated carbon followed a pseudo-second-order kinetic mechanism (R2 > 0.995). Therefore, the results show that the produced activated carbon can be used as a proper adsorbent for dye containing effluents.