Measurement and correlation of the individual ionic activity coefficients of aqueous electrolyte solutions of KF,NaF and KBr

Ion selective electrodes were used to measure the activity coefficients of individual ions at 298.2 K in aqueous solutions of KF, KBr and NaF up to 3, 2 and 1 molal, respectively. The mean ionic activity coefficients of the electrolytes obtained from the values of individual ions show good agreement with values reported in the literature. The experimental results confirm that the activity coefficients are different for the anion and the cation in an aqueous solution of a single electrolyte. It is also confirmed that the deviation from ideality for each ion depends on its counterion. The Khoshkbarchi—Vera equation was used to correlate the experimental data.     

Effect of the activation procedure on the performance of Mo/H-MFI catalysts for the non-oxidative conversion of methane to aromatics

The effect of pre-treatment on the performance of Mo/H-MFI zeolite catalysts applied to the non-oxidative conversion of methane to aromatics has been investigated. It is demonstrated that catalyst performance depends on activation conditions. Activation of the Mo-oxide/H-MFI precursor with an n-butane/hydrogen mixture results in higher catalyst stability and benzene selectivity which are tentatively attributed to the formation of the -MoC_1−x carbide, with f.c.c. structure as revealed by XRD.     

Alumina Dissolution into Silicate Slag

Dissolution of commercial white fused and tabular Al₂O₃ grains into a model silicate slag was investigated after 1 h at 1450° and 1600°C. Formation of CA₆ and hercynitic spinel layers was observed at all Al₂O₃/slag interfaces. The spinel layer was not always continuous, and so, compared with the CA₆ layer, it had a less-significant effect on the dissolution process. The CA₆ layer that formed adjacent to the tabular Al₂O₃ was incomplete at both temperatures, so that its dissolution was not a totally indirect process. These incomplete CA₆ and spinel layers meant that slag penetrated into the tabular Al₂O₃ grains, which, thus, were corroded and disintegrated by the penetrating slag. There was evidence of liquid in the CA₆ layer adjacent to the fused Al₂O₃ after 1 h at 1450°C, which also enabled direct dissolution. After 1 h at 1600°C, fused Al₂O₃ revealed a thick (∼60 μm), continuous and unpene-trated CA₆ layer, indicating fully indirect dissolution at this temperature.     

Dynamically vulcanized polypropylene/ethylene‐propylene diene monomer/organoclay nanocomposites: Effect of mixing sequence on structural,rheological, and mechanical properties

Dynamically vulcanized thermoplastic elastomer (TPE) nanocomposites based on polypropylene (PP), ethylene‐propylene diene monomer (EPDM) and cloisite 15A were prepared via direct melt mixing in a co‐rotating twin‐screw extruder. The mixing process was carried out with optimized processing parameters (barrel temperature = 180°C; screw speed = 150 rpm; and feeding rate = 0.2 kg/hr). The formulation used to prepare the nanocomposites was fixed to 75/20/5 (PP/EPDM/Cloisite^©15A), expressed in mass fraction. Effect of mixing sequence on the properties of vulcanized and unvulcanized (TPE) nanocomposites prepared under similar conditions was investigated using X‐ray diffraction (XRD) and a tensile testing machine. Results showed that the sequence of mixing does affect the properties of final TPE nanocomposites. Accordingly, nanocomposite samples prepared through mixing the preblended PP/clay masterbatch with EPDM phase, show better clay dispersion within the polymer matrix. J. VINYL ADDIT. TECHNOL., 22:320–325, 2016. © 2014 Society of Plastics Engineers     

The use of biomass and stillage recycle in conventional ethanol fermentation

Modifications of the conventional ethanol fermentation process using biomass and stillage recycle were investigated and the advantages of the technique were studied. The biomass recycle method resulted in a reduction in the use of approximately 8% raw material (molasses). The recycle of 15–70% of stillage (dealcoholised) from a previous fermentation was also tested successfully. Generally the results of these experiments revealed 13–47% less water consumption and consequently about 13–47% reduction of stillage volume, which was more economical for further treatments.     

The glass transition temperature of nitrated polystyrene/poly(acrylic acid) blends

Low-molecular-weight polystyrene was nitrated to different levels. The nitrated polystyrene was blended with different molecular weights of poly(acrylic acid), PAA. The glass transition temperatures (T_g) for the mixtures were investigated by differential scanning calorimetry. A single T_g was observed for all blends, indicating single-phase blends. In general, it was found that the T_g increases with molecular weight of PAA. The T_g values of the blends showed a positive deviation from the linear average T_g as a result of strong hydrogen bonding between the segments of the component polymers. The observed T_g values were not adequately represented by simple predictive equations or by single-parameter fitting equations. However, two-parameter fitting equations gave a reasonable representation of the data.     

MRI and PET image fusion using structure tensor and dual ripplet-II transform

Multimedia Tools and Applications - Medical image fusion aims at preserving salient image features, reducing the redundancy, and increasing the interpretation quality of images in clinical...     

Fucoxanthin content and antioxidant properties of Undaria pinnatifida

This study investigated the fucoxanthin content of New Zealand (NZ) Undaria pinnatifida harvested from two locations in the Marlborough Sounds, New Zealand across its growing season. Fucoxanthin content and antioxidant properties of processed New Zealand U. pinnatifida and commercial wakame from Japan and Korea were further compared. Results showed that U. pinnatifida harvested from Port Underwood had higher fucoxanthin content in the blade compared to Pelorus Sound. The sporophyll also contained a significant amount of fucoxanthin throughout the harvest season, although lower than in the blade. Two antioxidant measurement methods, DPPH and CUPRAC, were utilised to measure antioxidant activities. Processed NZ U. pinnatifida had a lower fucoxanthin content and antioxidant activity than freeze-dried Undaria. Fucoxanthin content and antioxidant activities of NZ processed U. pinnatifida were not significantly different from other commercial samples from Japan and Korea. In conclusion, U. pinnatifida in New Zealand has a great potential to be a food and nutraceutical resource.     

Synthesis and characterization of two new vinyl groups containing alkoxysilanes and their uses in the vinyl acetate/2-ethylhexylacrylate copolymer latexes

The incorporation of alkoxysilanes into latex systems is of major interest in the field of colloidal science. Two novel vinyl-containing alkoxysilanes, 3-(trimethoxysilyl) propylthiomethacrylate (TMSPTM) and methacryloxyethyl triethoxysilylpropylcarbamate (METESPC) were prepared by the condensation reaction of methacryloyl chloride (MC) with (3-mercaptopropyl)-trimethoxysilane (MPTMS) and addition reaction of 2-hydroxyethyl methacrylate (HEMA) with (3-isocyanatopropyl) triethoxysilane (ICPTES), respectively. Then these monomers were copolymerized with vinyl acetate and 2-ethylhexylacrylate (VAc/2-EHA) by seeded emulsion polymerization, and copolymer latexes were obtained. One kind of vinyl-containing alkoxysilane, the triethoxyvinylsilane (TEVS) has been used as coupling reagent for comparison of the effects of alkoxysilane types on the latexes. The structural elucidation of monomers was carried out by FT-IR, ¹H NMR, and ¹³C NMR spectroscopic techniques. The VAc/2-EHA copolymer latexes with TMSPTM or MPTMS were also characterized by FT-IR. The thermal stability of copolymers was respectively studied by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The morphologies of the latexes were characterized with scanning electron microscopy (SEM).