Synthesis of tailor‐made nanoporous polyaniline derived with PVA/alkaline metal system for metal complexation

Nanoporous polyanilines (PANIs) have attracted attention due to well‐defined molecular structures and chemical versatility, which also complicate the mechanisms of interaction between metal ions and PANI. To further understand the complexation with metal ions, tailor‐made nanoporous PANIs were synthesized with self‐stabilized dispersion polymerization (SSDP) using the poly(vinyl alcohol) (PVA) and various alkaline metals for suitable target metal complexation. The effective complexation results for the removal of Cr ions were obtained by the nanoporous PANI derived from a PVA/Li system. The synthesized tailor‐made PANI‐emeraldine base (EB) was easily oxidized by a Cr(VI) oxidant resulting in an pernigraniline form with a rigid polymer template and effective metal ion binding sites, and then the reduced form of Cr(III) can be complexed with the resulting PANI. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Airborne Particle Generation Through Acoustic Ejection of Particles-In-Droplets

This article reports a method to produce airborne particles by generating uniformly sized droplets that contain particles, where the droplets are made with an acoustic ejector that does not need any small orifice or nozzle which might become clogged. We demonstrate stable and continuous ejection for more than 10 minutes of 14-μ m droplets containing 1-μ m polystyrene latex (PSL) particles at a concentration of 1% solids. There was no indication of clogging. We have demonstrated ejection of droplets containing PSL at rates up to 3,000 droplets/s (90,000 1-μ m-PSL particles/s). This method should produce, at a known rate, (1) uniform particles of known volume when the particles are soluble in the liquid and/or (2) particles with a statistical distribution (e.g., Poisson distribution) when the particles are aggregates of primary particles. The method should be useful for aerosol generation systems requiring no volatile organic compounds (VOC).     

Sorptive removal and recovery of nickel(II) from an actual effluent of electroplating industry: Comparison between <Emphasis Type="Italic">Escherichia coli</Emphasis> biosorbent and Amberlite ion exchange resin

The removal and recovery of nickel(II) from wastewater of an electroplating factory was investigated using the waste Escherichia coli biomass as the biosorbent. The results were compared with those from using Amberlite IRN-150 as a commercial sorbent resin. The resin showed better performance with a q _max value of 30.48 mg/g compared to 26.45 mg/g for the biomass, as predicted by the Langmuir isotherm model. Kinetic experiments revealed that the biosorption equilibrium was attained within 15 min. In the recycling of the sorbents, the desorption of nickel(II) from Amberlite was only 50%, which is too low for the adsorption performance of the resin to be maintained at an economic level in subsequent cycles. In contrast, the biomass exhibited reasonable adsorption-desorption performance over three repeated cycles. The capability for repeated use of the sorbent over several cycles and for recovery of the metal ions is the main advantage of the waste biomass.     

Beamforming for Downlink Multiuser MIMO Time‐Varying Channels Based on Generalized Eigenvector Perturbation

A beam design method based on signal‐to‐leakage‐plus‐noise ratio (SLNR) has been recently proposed as an effective scheme for multiuser multiple‐input multiple‐output downlink channels. It is shown that its solution, which maximizes the SLNR at a transmitter, can be simply obtained by the generalized eigenvectors corresponding to the dominant generalized eigenvalues of a pair of covariance matrices of a desired signal and interference leakage plus noise. Under time‐varying channels, however, generalized eigendecomposition is required at each time step to design the optimal beam, and its level of complexity is too high to implement in practical systems. To overcome this problem, a predictive beam design method updating the beams according to channel variation is proposed. To this end, the perturbed generalized eigenvectors, which can be obtained by a perturbation theory without any iteration, are used. The performance of the method in terms of SLNR is analyzed and verified using numerical results.     

Cable-TV-based home video streaming system: practice and experience

This article presents a practical home video streaming system that has actually been implemented and deployed for commercial services on a cable television network. Because streaming components and network connections of a cable TV network are considerably different from those of desktop streaming systems available on the Internet, traditional systems and techniques for video streaming are not enough for a cable TV network. Therefore, several special systems and server-centric streaming techniques have been developed for a cable TV network and home video clients. In particular, server-centric streaming techniques are crucial because a set-top box, which is the client in the case of a home video streaming system, lacks processing power. We have developed a highly efficient streaming server using network acceleration and data bypassing techniques. As a result, our stateof- the-art streaming server enables high scalability and provides various content navigation modes, including faster playback, to off-the-shelf set-top boxes.     

Memory characteristics of MOSFET with silicon nanoclusters formed using a pulse-type gas-feeding technique in the LPCVD system

The digital gas-feeding method was used in this study, with Si₂H₆ as the source gas, in a low-pressure chemical-vapor deposition system, to grow Si nanoclusters with high densities and uniform sizes. The densities of the Si nanoclusters rose to 7 × 10¹¹ cm⁻², and their sizes slightly changed at about 7 nm based on the frequency of gas-pulse feeding in the digital process. MOSFETs containing Si nanoclusters as a floating gate in the gate stack were fabricated, and the various nonvolatile-memory characteristics of MOSFET were investigated. The total threshold voltage shift of 3.7 V was achieved, and the program/erase times were found to be 5 μs/50 ms when the program/erase voltages were +18/−20 V, respectively. The charge-storage memory window was extrapolated over 1 year to be 1.5 V in the retention measurements of the fabricated Si nanocluster floating-gate memory device.     

Piezoelectrically actuated dome-shaped diaphragm micropump

This paper describes a piezoelectric micropump built on a dome-shaped diaphragm with one-way parylene valves. The micropump uses piezoelectric ZnO film (less than 10 /spl mu/m thick) to actuate a parylene dome diaphragm, which is fabricated with an innovative, IC-compatible process on a silicon substrate. Piezoelectric ZnO film is sputter-deposited on a parylene dome diaphragm with its C-axis oriented perpendicular to the dome surface. Two one-way check valves (made of parylene) are integrated with a piezoelectrically actuated dome diaphragm to form a multi-chip micropump. The fabricated micropump (10/spl times/10/spl times/1.6 mm/sup 3/) consumes extremely low power (i.e., 3 mW to pump 3.2 /spl mu/L/min) and shows negligible leak up to 700 Pa static differential pressure.     

Discolouration of raw and cooked coloured fleshed potatoes differing in anthocyanins and polyphenols content

Despite variations in the content of polyphenols, the tested potato varieties with red and purple flesh contained similar amounts of anthocyanins. Potatoes of the red-fleshed HBr variety were distinguished by a significant content of pelargonidin-3-feruloylrutinoside-5-glucoside, and those of the purple-fleshed Vitelotte variety were characterised by a significant cyanidin-3-rutinoside content. Immediately after cutting, raw potatoes with red flesh showed a small share of yellow (b* parameter) and double the share of red (a*) as compared to purple-fleshed tubers. A reduction in the share of red dye was observed in purple- and red-fleshed potatoes except Vitelotte and Rosalinde tubers, at both 1 and 4 h after being cut. The flesh colour of cooked potatoes was characterised by low susceptibility to darkening, and purple-fleshed tubers were more saturated by chroma than tubers of red-fleshed varieties.