Advanced Materials Research Vols. 622-623

Abstract: In this paper mixing of reclaimed material with virgin asphalt material has been studied non-destructively. Specimens prepared with virgin asphalt mix and with asphalt mix containing reclaimed material were scanned in X-ray Computed tomography (CT). The obtained Images were analysed for particles and pores (air voids) distribution. All the specimens were also tested in compression test and X-ray scanned while testing. It was found that distribution of reclaimed is not uniform through the samples. There is no considerable effect of increasing the mixing time on particles’ distribution. Similar trend of increase in air voids (cracks) with the increase in load was found for both virgin mix and for asphalt mix containing reclaimed material. Only at failure the increase in voids was found higher for specimens containing reclaimed material.

Abstract: The present study investigates the effect of process parameters like tool rotational speed and tool feed on the mechanical and tribological properties of friction stir processed AZ31B magnesium alloy. The experiments were conducted with 3 level 2 factors full factorial design with two replications. The responses were tensile strength, microhardness and wear. The results were analyzed with the help microstructures of the processed samples. The study reveals that, for all responses, the most significant influencing process parameter is the tool rotational speed.

Abstract: The effects of a polyelectrolyte dispersant agent, polyethyleneimine (PEI), on the rheology of zirconia 3Y-TZP suspensions and the densification characteristics of sintered zirconia were investigated. The colloidal processing technique was used to minimize the agglomeration of nanoparticles during the fabrication of the samples. Five batches of 10% zirconia suspensions containing different amounts of PEI at 0.3, 0.4, 0.5, 0.6, and 0.7 wt% were prepared. The rheological properties of the zirconia suspensions were determined using a rotational viscometer. The optimum amount of PEI that can maximize powders dispersion was determined. The green samples were then prepared using the slip casting process. The samples were densely sintered at a final sintering temperature of 1300 °C. The result revealed that the zirconia suspension with 0.5 wt% PEI was the most optimum amount to obtain a well-dispersed suspension. The sintered density of zirconia 3Y-TZP reached its maximum by adding 0.5 wt% PEI.

Abstract: We present feasibleness of the thermoelectric generator (TEG) from the long thin P-Ca₃Co₄O₉ (CCO) and N-CaMnO₃ (CMO) legs constructing of Cu electrodes, silver paint and ceramic plates to achieve good electrical conduction that improved the performance of the TEG module. The P and N legs synthesized by solid state reaction (SSR) method and measured thermoelectric properties in air dimension of 0.5×20×3 mm³ attracting on ceramic substrate size of 25×25×1 mm³. The electrical voltage and current as a function of temperature difference <160 K were measured. The module boundary condition, the distribution current, current density, distribution voltage, distribution temperature and thermal flux were simulated by finite element method for comparison. The TEG fabrication has been obtained the electrical voltage, current and power of 10 mV, 0.25 µA and 0.025 µW.

Abstract: Single crystals of K_0.5Na_0.5NbO₃ (KNN) and 5wt%, 10wt%, 15wt% of Sb doped KNN crystals were grown by flux method. The formation of crystalline structure, microstructure, domain structure and the dielectric properties were investigated for both pure and Sb doped KNN single crystals. X-ray diffraction (XRD) pattern shows that pure and doped KNN single crystals have orthorhombic perovskite structure. The doped crystals have slight shrinkage in the unit cell volume. The partial substitution of the B-site ion Nb₅₊ by the Sb₅₊ ion in the KNN single crystal results in decreasing phase transition temperatures T_O-T and Curie temperatures TC of the doped crystals with increasing amount of Sb. The dielectric properties of the doped crystals show significant improvement with doping concentration. The peaks slightly shift towards lower frequencies with increasing dopant concentration.

Abstract: Molecular imprinting technology is a convenient approach for preparing synthetic receptors that possesses user defined recognition properties. Oxalic acid imprinted bulk polymer was synthesized by thermal initiated free radical co-polymerization of oxalic acid (template) with two different functional monomers (acrylamide and methacrylic acid) and ethylene glycol dimethacrylate as crosslinker, using acetonitrile (porogen) as solvent. Scanning electron microscopy and FT-IR spectra confirmed the formation of molecularly imprinted polymer (MIP) with acrylamide. The synthesized MIP_(ACR) efficiently adsorbed oxalic acid from aqueous solutions. The binding parameters of molecularly imprinted polymer and non-imprinted polymer were compared by Langmuir-Freundlich adsorption (LF) isotherm.

Abstract: The Pd(II)-catalyzed cross-coupling Suzuki-Miyaura reaction of aryl boronic acid and aryl halide was investigated. We found that 1% PdCl₂(PPh₃)₂,10% PPh₃ and 1 M Na₂CO₃ (aq.) in refluxing 1,4-dioxane for 4 hours is the optimize condition. The desired products e.g. 2-phenyl pyridine and bipyridine derivatives were obtained in moderate to excellent yields.

Abstract: Nowadays, the escalation of technology automotive produced a lot of transports. In connection with that, the rates of accident increased also. The application of composites from fiber is many used as a part of transport. The fiber composite used to absorb the impact directly from that accident. Filament winding is one of method to make a composite fiber. In this investigation, mandrel are made from wood with consists of cone with vertex angle 5ºand 10º. Glass fiber filament is use to winding the mandrel with different orientation angle. The orientations angle is 45°/-45°, 90°/45°, 90°/45°/90°, 45°/90°/-45°, 45°/-45°/45°/-45° and 90°/45°/90°/-45°. Resin epoxy used when process of winding start. Then, the specimen will test with impact testing in 4 velocities which 2.7 m/s, 3.1 m/s, 3.4m/s and last 3.8 m/s. Data from that testing will analyst and discuss. In conclusion, the result shown that both vertex angle and fiber orientation controlled the performance of energy absorption capability. The energy absorption increased when impact loading velocities increase. It is observed that different collapse mechanism have characterized the performances of specific energy absorption. The collapse mechanism happened are ring types splitting.

Abstract: Deformation modeling of an infinite plate of functionally graded materials (FGMs) loaded by normal force to the plate surface is studied. The material properties of FGM plate are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The governing equations are based on stress-strain relation and the equilibrium force equation. Keeping generality, FGM plate has been assumed as a multilayer with linear material property in each layer while arbitrary exponential material property through the thickness. A plate made of Aluminum and Alumina is considered as an example to illustrate the effects of the volume fraction exponent and number of layers on the plate deformation response. Effects of number of layers on the accuracy of the plate behavior under external load are examined. Results indicate that at every certain power-law (M), there exist a number of layers beyond which no variation can be detected on the plate deformation response.

Abstract: Different types of functionalized polymer magnetic core with diameters of 10-20 nm were prepared by condensation polymerization. Bi-layered polymer magnetic core nanoparticles were prepared by coating of magnetic core hydrophobic polymer shell composites of magnetic polyvinylbenzyl chloride with another layer. The second layer consists of 3-amino-1-propanol, butyl-l, 4-diamine or hexamethylenediamine The morphology and size of the magnetic polymer nanoparticles were characterized by TEM. The structure was characterized by IR, TGA and chemical stability against concentrated hydrochloric acid. The magnetic nanocomposites with hydrophilic behavior were easily separated by magnetic field and gives enhancing for using as nanocarrier in bioapplications.