Abstract: The planar solid oxide fuel cell (p-SOFC) is a promising configuration of a high-T fuel cell. Barium alumosilicate glass ceramics are suggested to use as sealants by many authors since these materials seem to meet the requirements to establish a hermetic and electrically insulating seal between the steel components of the SOFC. However, in long-term application, the formation of BaCrO4 may degrade the interfacial strength between glass-ceramics and metallic interconnect and disrupt the cell components. In this work, a series of barium-free glass-ceramics in the system of CaO-MgO-B2O3-Al2O3-SiO2 were prepared. The selected compositions were located within the constitutional range of åkermanite – forsterite –anorthite. The thermal properties including glass transition temperature (Tg) and crystallization temperature (Tc) of the produced glasses were measured. The effect of boron oxide additions was studied in order to optimize the softening and flow behavior. For the experiments, a hot – stage microscope was used. Some glass compositions were mixed with high – CTE akermanite powder in order to increase their CTE after sintering. The CTE of the investigated materials after sintering at 900 °C, 2 h, ranged from 10.5 to 11.8 10−6 K−1.
Abstract: Currently solid wastes generated from manufacturing process of thermosetting composite have caused environmental problems because they are non biodegradable product and cannot be recycled or remolded due to chemically crosslinked. Thus, the aim of this research is to convert glass fiber reinforced epoxy composite waste to fuel gases by gasification process. The composite waste was first grounded and its thermal decomposition behavior was then investigated using isothermal thermogravimetric analysis (TGA) from an ambient to 900°C at heating rate of 10°C/min under nitrogen atmosphere. The results showed that major decomposition temperatures of the epoxy matrix were ranging from 300 to 450°C. The composite sample was then mixed with two different catalysts, olivine (LiFePO4) or 10%NiAl2O3 in order to study the effect of catalyst on gas conversion efficiency before it was gasified in a fixed bed reactor at final temperature of 500, 600, 700, and 800°C under nitrogen mixed with air at total flow rate of 200 mL/min. Gasification process indicated that solid residues were mainly brittle black containing residual glass fiber. The significant increasing of carbon monoxide and carbon dioxide conversion was achieved from sample mixed with olivine catalyst at gasification temperature of 700°C, when compared with result without catalyst at baseline conversion of 500°C as. Therefore, it can be expected that gasification process is a promising method to deal with epoxy composite for producing renewable energy.
Abstract: We have annealed the thin layer of the amorphous silicon (a-Si) using the Q-swtiched Nd:YAG laser pulses in order to transform the a-Si into polycrystalline silicon (poly-Si) and investigated the crystalline structures of the poly-Si. Before illuminating the light to the layer, the frequency of the laser was doubled through the second harmonic generation (SHG) process to enhance the absorption efficiency of the optical energy. When the optical energy was higher than 500 mJ/cm2, we could obtain the micro-crystalline structure with grain size as large as 500 nm.
Abstract: Expansion-treated rice husk (ERH) had been used as adsorbent for removing copper(II) ions, and showed strong adsorption ability and removal efficiency for copper(II) ions. In this paper, the surface and bulk structures of ERH adsorbent were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM), ERH was treated by water solution with different pH value, and the adsorption performance of ERH for copper(II) ions was investigated through adsorption static experiments in order to study the adsorption mechanism. The result showed that ERH treated by alkaline solution had high removal efficiency for copper(II) ions, the reason ascribed to the large surface area of ERH. ERH had competitive adsorption for H+ and Cu2+, and a monolayer adsorption process played an important role in the whole process.
Abstract: Purified cadmium sulfide crystals were successfully synthesized from 1:2 molar ratio of Cd and S powders by a 900 W microwave plasma for 120 min and 140 min. In the present research, XRD and SAED patterns including SEM, TEM, and FIB images were used to indicate phase and morphology of the products, with their Raman peaks at 303 and 605 cm-1. Photoemission was determined to be 537 nm, and direct energy gap (Eg) to be 2.48-2.51 eV.
Abstract: The ceramic layers containing Cu(II) were prepared by Micro-arc Oxidation on aluminum under alkaline electrolyte (NaSiO3; Cu(Ac)2; Na2WO4; Na3PO4; Na2B4O7). Using x ray photoelectron spectroscopy, scanning electron microscopy, ultraviolet spectrophotometry and chemical oxygen demand analyzer on the film composition, structure and catalytic properties were characterized. The results showed that when the Cu2p peaks emerged in XPS pattern, the corresponding substances were CuO and Al2CuO4, it told us that there had the catalyst in the ceramic coating composition containing CuO. As can be seen from the SEM image analysis, with the pulse width increased, the ceramic layer surface volcanic hole size also increased and the area density trended to loose. Meanwhile, phenol oxidation test results demonstrated that with the pulse width parameter increasing, the catalytic effect of the micro-arc oxidation ceramic layers trended to increasing. However, at higher pulse width such as 750 microseconds, the conversion rate of phenol was weakened strongly.
Abstract: The palladium membranes were fabricated by mean of electroless plating method which provided thin and uniform film on a tubular alumina porous support. Subsequently, the annealing process which is one of the effective ways to enhance the permeability of membrane was performed in the temperature range of 600-800°C. The annealing temperature and time were found to have influence on membrane microstructure and its performance. Palladium annealed at 700°C for 8 hrs in nitrogen atmosphere had the highest hydrogen permeability and separation factor when operated at 600°C. The membrane morphologies observed by SEM showed that the sample treated at higher temperature had lower surface roughness. The annealed palladium composite membrane at 800°C revealed that some voids which occurred during electroless plating process were enlarged and caused the lower separation factor.
Abstract: The performance of expanding rice husk (ERH) fixed bed column in removing Zn (II) from aqueous solution were studied in this work. Different column design parameters like bed height, flow rate and initial concentration were calculated. It was found that ERH was found to be an effective adsorbent for removal of Zn (II); and when conducted with Zn (II) concentration 12.8 mg L-1 and flow rate 10 ml min-1 with different bed depths such as 3, 6 and 9 cm, the equilibrium uptake was decreased from 5.181 to 4.33 mg g-1; the equilibrium uptake also decreased from 4.51 to 3.807 mg g-1 with increasing of flow rate from 5 to 15 ml min-1 and increased from 4.447 to 5.752 mg g-1 when initial concentration increased from 12.8 to 35 mg L-1. The dynamics of adsorption process was modeled by bed depth service time (BDST), and indicating the validity of BDST model when applied to the continuous column studies.
Abstract: New thermoplastic soy protein isolated (SPI) and methyl methacrylate (MMA) copolymers (T-SPI) were prepared using graft copolymerization and initiated with ammonium persulfate (APS). The reaction conditions such as initiator concentration and temperature on the graft percentage (GP) were investigated. The single factor experimental showed that the optimal conditions of the graft reaction. The products were characterized by means of FT-IR and DSC. The results indicated that the monomer was grafted successfully on SPI and the T-SPI had a glass transition at 122°C, and the most important, the water absorption of materials declined obviously.