Applied Mechanics and Materials Vols. 229-231

Abstract: Removal the pollutants of the polluted water through flotation bio-film are reached by the cooperation work of microbial degradation and sand filter. This paper through dosing the bacterial suspension and nutrition did the research on biofilm accretion. Results showed that the biomass on quartz sand had greatly increased, and the removal rates of organic and ammonia nitrogen also had a huge increase. At the end of biofilm accretion, the removal rates of pollutants keep at a stable value.

Abstract: Ibuprofen suspensions were prepared by simple homogenization with melt-emulsification process. Tween 80 was used as stabilizer. The homogenized suspensions were evaluated and compared with melt emulsificated suspension. The pH value and rheology behavior were not difference. The viscosity was very low. Zeta potential was -10 to -25 mV. In this study, the suitable process to minimize particle size of ibuprofen suspension was melt emulsification follow by sonication. This process could be developed to obtain nanosuspension by adjust sonication process and improved formulation to obtain suitable nanosuspension.

Abstract: The reconstruction and electronic structures of the interfaces between single wall carbon nanotubes and ferromagnetic Co electrodes were studied in the framework of density functional theory. The obtained results revealed that there is a strong interaction between carbon nanotubes and Co electrodes. At the interface region, Top layers of Co surface have been significantly reconstructed. The nature of chemical bonds at the Co-C interface is covalent bonding. The increase of the electron density occurs mainly at the interface where a substantial concentration of electron accumulates in Co-C bonds. A small amount of charge transfer from Co electrode to carbon nanotube junction was found. In addition, the spin polarization of Co atoms at the interface region has been suppressed due to the interaction with a carbon nanotube. It implies that the spin transport through this layer is low, which results in the small hysteretic magneto-resistance of carbon nanotube devices.

Abstract: Colloidal silicon dioxide is a fine amorphous powder consisting of particles about 7-40 nm in size. This study utilized hydrophobic colloidal silicon dioxide, aerosil R 972, as gelling agent in non-aqueous systems. Aerosil R 972 could convert light mineral oil and Luvitol EHO® into gel at concentrations of 7 and 10% by weight, respectively. The appearance of the systems prepared from polyethylene glycol 400, 600 and light mineral oil was clear, but the others were turbid. There was no phase separation or color changes of the systems after temperature change of 6 cycles. The obtained gel exhibited very little change of pH and viscosity after stability testing. After aerosil R 972 was incorporated into the mixed media with different dielectric constant, all systems showed the decrease of a viscosity, especially, the formulations having low dielectric constant. The addition of aerosil R 972 into dispersing medium with higher dielectric constant provided higher viscosity of the system because of the mismatch of the polarity between particles and dispersing media. In case of the incorporation of aerosil R 972 into mixed media, the rank order of viscosity was PEG 400–glycerin> PEG 400–PG > PEG 400–water. All of PEG 400–glycerin mixtures were obviously converted into gel, while only PEG was not converted with aerosil R 972 addition.

Abstract: Organic light emitting diodes (OLEDs), charged iridium(III) complexes, spiro ligand Abstract. We report the synthesis, characterization and photophysical properties of a cationic cyclometalated Ir(III) complexes of general formula [Ir(ppy)2(spbpy)]⁺Cl, [Ir(diFppy)₂(spbpy)]⁺Cl^ and [Ir(thiopy)2(spbpy)]⁺Cl where ppy, spbpy, diFppy and thiopy are 2-phenylpyridine, 4,5-diaza-9,9′-spirobifluorene, 2-(2′,4′-difluorophenyl)-pyridine and 2-(thiophen-2′-yl)-pyridine, respectively. The complexes exhibit strong absorption bands in the UV region in solution spectra, due to spin-allowed ligand-centred (LC) and weaker absorption bands at longer wavelengths from metal-to-ligand charge transfer (MLCT). The photoluminescence spectra of all the complexes were characterised by a combination of 3MLCT and ³π→π^* states. The emission color of a cationic cyclometalated Ir(III) complexes in solution have successfully tuned from green to orange (501-582 nm).

Abstract: The molecular-scale pore structure, called nanopore, interacting with target molecules in its functionalized lumen, can produce characteristic changes in the pore conductance, which allows us to identify single molecules and simultaneously quantify each target species in the mixture. Nanopore sensors have been created for tremendous biomedical detections, with targets ranging from metal ions, drug compounds and cellular second messengers, to proteins and DNAs. Here we will review our recent discoveries with a lab-in-hand glass nanopore: single-molecule discrimination of chiral enantiomers with a trapped cyclodextrin, sensing of bioterrorist agent ricin and site-directed capturing a single nanoparticle.

Abstract: The remarkable properties of graphene nanoribbons (GNRs) make them attractive for nano-scale devices applications, especially for transistor and interconnect. Furthermore, for reduction interconnects signal delay, low dielectric constant materials are being introduced to replace conventional dielectrics in next generation IC technologies. With these regards, studding the effect of varying dielectric constant (ɛr) on relative stability of graphene nanoribbons interconnect is an important viewpoint in performance evaluation of system. In this paper, Nyquist stability analysis based on transmission line modeling (TLM) for graphene nanoribbon interconnects is investigated. In this analysis, the dependence of the degree of relative stability for multilayer GNR (MLGNR) interconnects on the dielectric constant has been acquired. It is shown that, increasing the dielectric constant of each ribbon, MLGNR interconnects become more stable.

Abstract: Achieving dense off-chip interconnection with satisfactory electrical performance is emerging as a major challenge in advanced system engineering. Graphene nanoribbons (GNRs) have been recently proposed as one of the potential candidate materials for both transistors and interconnect. In addition, development is still underway for alternative materials and processes for high aspect ratio (AR) contacts. Studding the effect of varying aspect ratio on relative stability of graphene nanoribbon interconnects is an important viewpoint in performance evaluation of system. In this paper, Nyquist stability analysis based on transmission line modeling (TLM) for GNR interconnects is investigated. In this analysis, the dependence of the degree of relative stability for multilayer GNR (MLGNR) interconnects on the aspect ratio has been acquired. It is shown that, with increasing the aspect ratio of each ribbon, MLGNR interconnects become more unstable.

Abstract: M-type strontium hexaferrites with substitution of Fe³⁺ by Al³⁺, according to the formula SrAl_xFe12_-xO₁₉ (x=0, 1, 2, 3, 4, 6, 8, 10), are prepared by the sol-gel auto-combustion method. Influences of the substituted amount of Al³⁺ on structure and magnetic properties of SrAl_xFe12_-xO₁₉ compounds have systematically been investigated by XRD, TEM and VSM. X-ray diffraction shows that the samples are single M-type hexagonal ferrites. Because of the resemblance of Al³⁺ ionic radii with Fe³⁺ the two ions are easily replaced at any substitution ratio without changing the crystal structure. The materials show structural and morphology changes upon replacement of iron by aluminum. A shift in peak position to larger angles shown by XRD is observable with increasing aluminum doping. The values of Ms, Mr and Hc decrease with the addition of Al content but there is an exception for x=3 when H_c=8.9 KO_e.

Abstract: We synthesized polyimide (based on ODA-PMDA) and polyimide foam and polyimide/clay foam that pore size was uniform about 1㎛. We identified that the clay layers are well dispersed in polyimide matrix and achieved exfoliation structure by X-ray diffraction. And we compared thermal conductivity of PI, PI foam, PI/clay foam. Thermal conductivity decreased up to maximum 28 % by introducing both pores and clay layers. Exfoliated structure of clay leads to decrease of thermal conductivity by thermal barrier effect. Also, the presence of clay could considerably reinforce the poor mechanical properties of polyimide by foam because of interfacial interaction between clay layers and polymer matrix. Through the this results, it has shown that this study may provide an effective method to prepare polymer/clay nanocomposite foams having exfoliation structure, and can be used as insulating material having low thermal conductivity.