Evaluation of the pseudocapacitance in RuO2 with a RuO2/GC thin film electrode

The pseudocapacitance of nanocrystalline RuO₂ with BET surface area of 42 m² g⁻¹ was evaluated using a RuO₂ modified Glassy Carbon (RuO₂/GC) thin film electrode. The charge storage behavior of the RuO₂/GC thin film electrode was studied from fast to slow scan cyclic voltammetry between various potential windows. The utilization of the thin film electrode method for nanocrystalline RuO₂ with known specific surface area allowed a semi-quantitative understanding of the electric double-layer capacitance (C_dl), adsorption related charge (C_ad), and the irreversible redox related charge (C_irr) per unit mass and surface area of RuO₂. Comparison of the cyclic voltammograms between different voltage windows revealed that the contribution from C_irr is especially dominant below 0.4 V (versus RHE) at slow scan rates.     

Dyeing properties of oxygen low-temperature plasma-treated wool and nylon 6 fibres with acid and basic dyes

Wool and nylon 6 fibres treated with oxygen low-temperature plasma were dyed with acid and basic dyes. Despite the increase of electronegativity of the fibre surface caused by the plasma treatment, the rate of dyeing of wool was increased with both dyes, while that of nylon 6 was decreased with the acid dye and increased with the basic dye.     

Revealing microbial community structures in large- and small-scale activated sludge systems by barcoded pyrosequencing of 16S rRNA gene

The diversity of bacterial groups in activated sludge from large- and small-scale wastewater treatment plants was explored by barcoded pyrosequencing of 16S rRNA gene. Activated sludge samples (three small and 17 large scale) were collected from 12 wastewater treatment plants to clarify precise taxonomy and relative abundances. DNA was extracted, and amplified by 4 base barcoded 27f/519r primer set. The 454 Titanium (Roche) pyrosequences were obtained and analyses performed by Quantitative Insight Into Microbial Ecology (QIIME) with around 100,000 reads. Sequence statistics were computed, while constructing a phylogenetic tree and heatmap. Computed results explained total microbial diversity at phylum and class level and resolution was further extended to Operational Taxonomic Unit (OTU) based taxonomic assignment for investigating community distribution based on individual sample. Composition of sequence reads were compared and microbial community structures for large- and small-scale treatment plants were identified as major phyla (Proteobacteria and Bacteroidetes) and classes (Betaproteobacteria and Bacteroidetes). Also, family level breakdowns were explained and differences in family Nitrospiraceae and phylum Actinobacteria found at their species level were also illustrated. Thus, the pyrosequencing method provides high resolution insight into microbial community structures in activated sludge that might have been unnoticed with conventional approaches.     

Diffusion-limited characteristics of mechanically induced currents in polypyrrole/Au-membrane composites

A mechanically induced current (MIC) in a polypyrrole/Au-coated membrane (PPy/Au-membrane) composite with various surface morphologies was investigated, and the electrolyte conditions were determined in an electrochemical cell. A MIC was induced on porous PPy/Au-membranes with a thin layer of PPy. Conversely, relatively small MICs were observed in non-highly porous films such as freestanding films and PPy/Au-membranes with thick PPy deposits. A MIC smaller by one order of magnitude was also observed in a Au-membrane without PPy. These results indicated that the MICs was due to a charging phenomenon in both the redox and the double layer capacitances. The MIC also varied with supporting electrolyte and their concentration. The MIC was strongly reduced in solutions with diluted electrolytes and with bulky cationic electrolytes, indicating that the number and the penetration speed of mobile ions limited the magnitude of the MIC. These characteristics indicated that the MIC was essentially a diffusion limited current. A two-electrode MIC cell was also configured to investigate a power generation film in a normal saline solution, which can possibly be utilized for biomedical applications.     

Solid state NMR analysis of poly(L‐lactide) random copolymer with poly(ε‐caprolactone) and its reactive extrusion process

A random copolymer based on poly(L ‐lactide) (PLA) with poly(ε‐caprolactone) (PCL) was prepared and characterized by mechanical testing and solid state NMR, compared with a polymer blend. For a monofilament sample consisting of PLA/PCL random copolymer, there were negative correlations between the CL content and the mechanical properties: tensile strength, tensile elastic modulus, flexural rigidity, and flexural hysteresis decreased with increasing CL content. In contrast, the mechanical properties of the polymer blend were only slightly changed by addition of the CL unit. For the random copolymer, the addition of a small amount of CL reduced relaxation times, T₁C and T_1ρH, gradually. The T₁C and T_1ρH values correlated closely with the tensile elastic modulus and the tensile strength, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and optical properties of azobenzene side chain polymers derived from the bifunctional fumaric acid and itaconic acid

Three type polymers containing the same azobenzene side chain group with different backbone structures, poly(DMAz6Fm), poly(DMAz6It) and poly(MAz6Ac) derived respectively from fumaric acid, itaconic acid and acrylic acid, were synthesized. The dependence of photo-response properties on the polymeric architecture was investigated for the solutions and films. By irradiation of the linearly polarized light (436 nm), uniaxial orientations of the thin films were induced and anisotropic properties were investigated by measurements of the order parameters and birefringence values.     

Immersion‐Angle Dependence of the Resonant‐Frequency Shift of a Quartz Crystal Microbalance in Three Types of Newtonian Liquids

Abstract

The present work reports the new characteristics of the immersion‐angle dependence of the resonant‐frequency shift (ΔF) of the one‐face sealed quartz crystal microbalance (QCM) in three types of Newtonian liquids, i.e., sucrose, glucose, and glycerol solutions. Below some 1.80×10^?2 g cm^?2 · s^?1/2, the ΔF values are dependent on the immersion angles in all solutions. However, we have found that the transition phenomenon of ΔF occurs between 1.78×10^?2 and 4.80×10^?2 g · cm^?2 · s^?1/2 in the sucrose solution, between 1.75×10^?2 and 4.34×10^?2 g · cm^?2 · s^?1/2 in the glucose solution and between 1.83×10^?2 and 3.03×10^?2 g · cm^?2 · s^?1/2 in the glycerol solution, respectively. Moreover, above the concentrations of the end points of the transition phenomenon, the ΔF values of the sucrose solution are equal to those of 90° at all immersion angles. On the other hand, those of the glucose and the glycerol solutions are the same as those of 30°. This difference may be caused by inherent characteristics of adsorption to the surface of the QCM electrode.     

Dimeric C34 Derivatives Linked through Disulfide Bridges as New HIV-1 Fusion Inhibitors

C34, a 34-mer fragment peptide, is contained in the HIV-1 envelope protein gp41. A dimeric derivative of C34 linked through a disulfide bridge at its C terminus was synthesized and found to display potent anti-HIV activity, comparable with that of a previously reported PEGylated dimer of C34REG. The reduction in the size of the linker moiety for dimerization was thus successful, and this result might shed some light on the mechanism of the suppression of six-helix bundle formation by these C34 dimeric derivatives. Addition of a Gly-Cys(CH₂CONH₂)-Gly-Gly motif at the N-terminal position of a C34 monomeric derivative significantly increased the anti-HIV-1 activity. This moiety functions as a new pharmacophore, and this might provide a useful insight into the design of potent HIV-1 fusion inhibitors.     

Advanced treatment of secondary sewage effluent by membrane process

The experimental results on advanced treatment of secondary sewage effluent by ultrafiltration (UF) and reverse osmosis (RO) are presented in this paper, particularly focused on pretreatment system, operating condition, membrane cleaning system, and product water quality.     

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at concentrations lower than 8mgCL(-1) and then inhibited at higher concentrations. It is possible that the presence of the soluble humic acid fraction during the ozonation of TCE in acetic acid solutions produces hydroxyl radicals during the TCE ozonation which appears to be the reason for the enhanced TCE decomposition rate. Solid humic acid reduced TCE decomposition rate by acting as an ozone scavenger. Similarly, sorbed TCE reduced the amount of TCE available for decomposition by ozone in solution.