Abstract: Palm kernel meal (PKM) which is the by-products of palm oil industry consists of considerable amount of protein that showed its great potential to to be used as a filler of melamine-urea-formaldehyde (MUF) resin based wood adhesive. Besides, due to the high price of melamine, it is attempted to reduce the content of melamine in MUF resins to as low as possible. So, in this study, PKM was used as filler in MUF resin based wood adhesive to study its effects toward the performance of the adhesive. In practical, the shear strength performance tests are done by using automated bonding evaluation system (ABES). However, ABES is a destructive test that only produces one point of data per test. So, in order to make the evaluation of the prediction data more convenience, a response surface methodology D-optimal method was approached. From the results, it has shown that increasing in temperature and pressing time is not always true in obtaining higher shear strength performance for MUF resin with PKM as filler. Smaller the particle size of PKM filler in MUF resin, shorter time the high shear strength performance can be achieved. Also, the relationships of temperature, pressing time and particle size of PKM to obtain optimum and maximum shear strength were studied.
Abstract: Using laser monitoring technique and reliable apparatus, the solubilities of both 2-aminoethyl hydrogen sulfate (AHS) and taurine in water were determined by the dynamic equilibrium method. Results of these measurements were correlated with Wilson equation separately. The solubilities calculated by the model showed good agreement with experimental data for AHS. And the interaction energy parameters of Wilson equation g12-g11 and g21-g22 correlated for binary sysytem could be used to calculate the solubilities of AHS in water. It cauld not be best using it to calculate them of taurine in water.
Abstract: Catalysis is the major process involved in fuel cell technology to generate electricity which is known renewable. Generally, fuel cell electrodes utilize platinum supported carbon to catalyze the reactions at both cathode and anode. However, cheaper substitution materials such as nitrogen-doped carbon catalyst have attracted greater attention in recent year due to its significant catalytic activity at cathode in fuel cell. Nitrogen-doped CNT (N-CNT) is believed to allow oxygen reduction reaction (ORR) at cathode to take place which play a role as n-type dopant for electrical conductivity. The objective of this paper is to understand the mechanism of oxygen adsorption on N-CNT using the density-functional theory (DFT). N-CNT with two configurations involve sp2 and sp3 hybridized nitrogen are studied and compared in order to find the most thermodynamically stable N-CNT for sustainable ORR activity in fuel cell. The structural stability is studied through the binding energies of each configurations and the metallic behavior is examined through the energy gaps from the HOMO-LUMO studies. Finally, the adsorption energies and deformation energies of oxygen on N-CNT is discussed. Results revealed that sp3 hybridized N-CNT gives the most stable structure with compatible oxygen adsorption ability.
Abstract: The curing processes of a novelly synthesized siloxane-containing epoxy resin (SE) and bisphenol A diglycidyl ether (CYD-128) were investigated using dynamic differential scanning calorimetry (DSC), and analyzed by three different methods. The results show that while SE has a lower initial curing temperature and a smaller pre-exponential factor than CYD-128, their curing processes belong to first order kinetic reaction. All the three dynamic methods verified mutually reveal that SE with more catalytic hydroxyls possesses lower activation energy and exhibits a stronger curing reactivity than CYD-128.
Abstract: Solid - liquid Equilibria for the quaternary system Na2B4O7 - Na2SO4 - K2B4O7 - K2SO4 - H2O at 323K were studied experimentally using the method of isothermal solution saturation. Solubilities and densities of the solution of the system were measured experimentally. On the basis of experimental data, the phase diagram of the quaternary system was constructed. In the equilibrium diagrams of the quaternary system Na2B4O7 - Na2SO4 - K2B4O7 - K2SO4 - H2O at 323 K, there are three invariant points F1, F2 and F3, seven univariant curves E1-F1, E2-F1, E4-F3, E5-F3, E3-F2, F1-F2 and F2-F3, and five fields of crystallization corresponding to Na2B4O7·10H2O，K2B4O7·4H2O，Na2SO4，K2SO4 and Na2SO4·3K2SO4. The experimental results show that sulfates have bigger solubilities than borates in the quaternary system Na2B4O7 - Na2SO4 - K2B4O7 - K2SO4 - H2O at 323K.
Abstract: Spherical Ni0.5Mn0.5CO3 is synthesized via carbonate co-precipitation method which uses NH4HCO3 as the precipitator. However, obvious agglomerate of secondary particles occurs when NH4HCO3 is used as the precipitator. The agglomerate particles can result in inferior physical characteristic. An improved carbonate co-precipitation which used NH4HCO3 doped with different proportion of NaOH as a new precipitator is tested in our study. Observed by SEM and Mastersizer, spherical morphology with narrow particle size distribution is synthesized with the proportion of NaOH reaches 10%. The element line analysis by Electron Probe Micro-analyzer shows symmetrical distributions of Ni and Mn elements via the improved carbonate co-precipitation.
Abstract: LiNi0.75Co0.15Mn0.1O2 was prepared by solid state reaction and its crystal structure was studied by Rietveld Refinement. The result shows that the oxygen octahedron surrounding transition elements in LiNi0.75Co0.15Mn0.1O2 is distorted. The lengths of twelve edges of the octahedron are different. The lengths of twelve edges divided into two groups and their length is 2.7098Å and 2.8780Å respectively. The analysis shows that the change crystal fields due to transition metals and lithium ions results in the different length of octahedron edges in LiNi0.75Co0.15Mn0.1O2.
Abstract: Electrode performance is the most important part in proton exchange membrane fuel cell system because all electrochemical processes and chemical conversions into energy occur via electrode interface. However the main problem in widespread proton exchange membrane fuel cells (PEMFCs) applications is the cost of the catalyst and life time of electrode, due to different parameters effects. Intense research imply in reducing the cost with increase the activity of catalyst in additional to other parameters (components) to make electrode for PEM more efficient with reasonable cost. This paper review recent research for the most parameters affecting performance of (Pt/C and Pt/C/M ) electrode for proton exchange membrane fuel cells (PEMFCs) such as Catalyst oxidation (degradation), and life time of the electrode using Pt/C, gas diffusion layer (GDL) thickness, and loading of PTFE in the diffusion layer, Nafion@ solution in the catalyst layer, methods of fabrication of electrode as spraying, casting, and electro deposition methods. Then the link between these parameters to achieve high performance and avoid the electrode degradation by optimized these parameters.
Abstract: Polyaspartic acid (PASP) composite material, a scale and corrosion inhibitor, is prepared from PASP, acrylic acid-acrylic ester- itaconic acid tripolymer (IA-AA-AE) and 2-phosphonobutane- 1,2,4-tricarboxylic acid (PBTCA). The scale inhibition effects of PASP and PASP composite are investigated. Calcium carbonate crystals in scale samples are characterized by means of SEM. Experimental results show that the scale inhibition rate can reach 98.7 % and corrosion inhibition rate 96.5 % under the conditions of Ca2+ 639 mg.L-1 and PASP composite material 40 mg.L-1. SEM results show that calcite and aragonite can be transformed into vaterite completely by using PASP composite material.