Eco-Materials Processing and Design X

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Authors: Hong Gun Kim, Lee Ku Kwac, Yoo Shin Kim, Young Woo Kang
Abstract: An experimental and numerical study of polymer electrolyte membrane fuel cell (PEMFC) is presented and compared with the experimental data to investigate the effects of pressure gradient, flow rate, humidification and supplied oxidant type for the practical application. The membrane and electrolyte assembly (MEA) materials are implemented by double-tied catalyst layers. A single-phase two-dimensional steady-state model is is implemented for the numerical analysis. Testing condition is fixed at 60sccm and 70°C in anode and cathode, respectively. It is found that the performance of PEMFC depend highly on the conditions as gas pressure, temperature, thickness, supplied oxidant type (Oxygen/Air) as well as humidification. The results show that the humidification effect enhances the performance more than 20% and the pure oxygen gas as fuel improves current density more than 25% compared to ambient air suppliance as oxidant.
Authors: Byoung Soo Lee, Hoon Cho, Hyung Ho Jo
Abstract: Energy requirement and yield for production of aluminum wirerods manufactured by continuous casting process were investigated to enhance yield of aluminum wiredrods. Also, it was compared with conventional process including extrusion process. The enhancement of yield more than 30% could be accomplished through the continuous casting process. The conventional process including extrusion process for production of wirerods consumes more energy compared to continuous casting. In addition, a number of intermediate annealing may be introduced during wiredrawing process of wirerods manufactured by conventional process including extrusion process. It can be mentioned that continuous casting process is suitable process for wiredrawing process because it can save energy requirement not only during manufacturing process of wirerods but also during following wiredrawing process.
Authors: Shouhei Yanagiya, Yamato Hayashi, Hirotsugu Takizawa
Abstract: In2O3(ZnO)3 layered compound was synthesized by 2.45 GHz microwave heating in a solid state reaction. Microwave-processed samples were obtained at low temperature by the enhancement of solid state diffusion and sublimation of the powder bed. Plate-like grain microstructures formed on the bottom part of the pellet, and vicinity of the surface was dense. The plate-like grain was oriented in the ab-plane direction. Compared with a conventional heated sample, the electrical conductivity increased and the band gap energy decreased. In the case of deposition on a silica substrate by microwave heating, the plate-like grain film was synthesized.
Authors: Hoon Cho, Jae Hong Ha, Byoung Soo Lee, Sung Ho Chang, Je Sik Shin
Abstract: Eco-friendly grain refinement of A3003 alloy was studied by addition of non-toxic Al-Ti alloy because of toxic-fluorine in Al-Ti-B alloys which used as a representative grain refiner for aluminum and its alloys. TiAl3 phase in Al-Ti alloy bring to decrease grain size of A3003 alloy. But, grain growth occurred with prolonged holding time due to the solution of Ti into aluminum matrix. In contrast, lasting grain refinement of A3003 alloy was occurred in graphite crucible. It can be mentioned that carbon comes from graphite crucible was combined with Ti solute in aluminum melt and then TiC acts as a heterogeneous nucleation for A3003 alloy.
Authors: Zhi Zhou Chen, Jian Qing Wang
Abstract: In this study, corn starch was taken as the raw material and its filming property was studied through single-factor experiments and orthogonal experiment. The results showed that there were significant effects on properties of the corn starch films under different corn starch concentration, glycerol concentration, CMC-Na concentration and pH value of coating liquid. Referring to the effects on properties of corn starch films, the most important factor was the glycerol concentration, the following factors were the pH value of the coating liquid, the CMC-Na concentration and the corn starch concentration. The optimum filming condition was 5.5% corn starch, 1.0% glycerol, 0.15% CMC-Na and pH 6.0-6.9 for the coating liquid of film-forming.
Authors: Wei Ping Xu, Li Xing, Ling Min Ke
Abstract: The grain orientations and microtextures in a friction–stir–welded magnesium alloy AZ80A were analyzed by Orientation Imaging Microscopy (OIM).The results showed that times random of grain orientations in the nugget zone were not strong and orientations were variety. They brought on very fine equiaxed grains. It also showed that deformation texture of {1,-1,0,4}<1,0,-1,0> was a few departure 20deg from the sample normal, The grains in the nugget zone from the base metal inherited the deformation texture of {1, -1,0,4}<1,0,-1,0> . It was concluded that re-crystallized grains in the nugget zone formed by a continuous dynamic re-crystallized mechanism.
Authors: Khanh Quoc Dang, Makoto Nanko, Masakazu Kawahara, Shinichi Takei
Abstract: Densification and sample temperature of alumina (Al2O3) powder during pulsed electric current sintering with different pulse power generators, inverter type and pulsed direct current type were investigated. The sample temperature for inverter generator was higher than that for pulsed direct current generator in same die temperature ranging form 800 to 1400oC. The relative density increased with increasing of the sample temperature.
Authors: Jong Bin Park, Sang Ho Lee, Chae Sung Gee, Hee Bum Pyun
Abstract: Permeable pavement systems are suitable for a variety of residential, commercial and industrial applications because pavements such as water-retentive or water absorbing pavements are helpful to alleviate urban heat island phenomena by reducing pavement temperature, yet are confined to light duty and infrequent usage. And most of study for the permeable pavement is limited to asphalt pavement. Also, immense quantities of coal combustion by-products are produced every year, but only a small fraction of them are currently utilized, particularly bottom ash which is used in this study. So, in this study, it was intended to develop new permeable and water-absorbing pavement blocks to control pavement temperature and storm water runoff. And mechanical characteristics-compressive strength, porosity etc were carried out. Also, Experiments for thermal environment characteristics and pollution control were carried out in laboratory scale using modified pavement samples. Experimental results indicated that blocks with bottom ash were suited to standard and possessed excellent water-retentive and water purification ability.
Authors: M.W. Lee, Sung Lim Ryu, S.J. Yeom, Soon Young Kweon
Abstract: Ferroelectric properties of Lead-free (Bi,La)4Ti3O12 (BLT) films were evaluated on the newly developed MTP (Merged Top-electrode and Plate-line) cell structure. The BLT film was deposited by pulsed-DC sputtering method on a buried Pt/IrOx/Ir bottom electrode stack with W-plug. The BLT composition in the sintered sputtering target was Bi4.8La1.0Ti3.0O12. However, the deposited film composition was about Bi4.0La1.0Ti3.0O12 after the heat treatment of crystallization at 700°C/O2/30sec. And grains of the BLT film were randomly oriented and uniformly small ellipsoidal shape (long direction: ~100nm, short direction: ~20 nm). The remnant polarization (2Pr) and the leakage current density measured in the 100nm-thick BLT film were about 21 C/cm2 and 3 ×10-5 A/cm2 at 3 V, respectively. The fatigue loss was about 10% of the initial polarization value after 1×1011 fatigue cycles.
Authors: Jun Han, Bo Lin Wu, Shao Peng Wu
Abstract: This text contrapose on the contradiction between price of alumina powder material and performance of alumina ceramic manufacture at present. Abundant natural bauxite mineral in China as main raw materials was used through the favorable craft course and a small amount of other auxiliary additive to produce grinding medium which have the character of color white, higher performances, lower sintered temperature, fewer consume of resources, cheaper production cost, etc. And the problem of producing high-level grinding medium only using expensive industrial alumina powder was solved and pollution in production of alumina powder was avoided. So the environmental pollution and energy consuming can be reduced and high added value of bauxite can be achieved through this method. The experimental design continued to use the industrial production route and apt to realize industrialization, once it is put into production, enormous social effect will be achieved.

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