Electrical and mechanical properties of acrylonitrile‐butadiene‐styrene/multiwall carbon nanotube nanocomposites prepared by melt‐blending

The electrical properties in polymer/carbon nanotube (CNT) nanocomposites are governed not only by the degree of dispersion but also to a greater extent on the aspect ratio of the CNTs in the final composites. Melt‐mixing of polymer and CNTs at high shear rate usually breaks the CNTS that lowers the aspect ratio of the nanotubes. Thus, homogeneous dispersion of CNTs while retaining the aspect ratio is a major challenge in melt‐mixing. Here, we demonstrate a novel method that involves melt‐blending of acrylonitrile‐butadiene‐styrene (ABS) and in situ polymerized polystyrene (PS)/multiwalled CNT (MWCNT) nanocomposites, to prepare electrically conducting ABS/MWCNT nanocomposites with very low CNT loading than reported. The rationale behind choosing PS/MWCNT as blending component was that ABS is reported to form miscible blend with the PS. Thus, (80/20 w/w) ABS/(PS/MWCNT) nanocomposites obtained by melt‐blending showed electrical conductivity value ≈1.27 × 10^?6 S cm^?1 at MWCNT loading close to 0.64 wt %, which is quite lower than previously reported value for ABS/MWCNT system prepared via solution blending. Scanning electron microscopy and differential scanning calorimetry analysis indicated the formation of homogenous and miscible blend of ABS and PS. The high temperature (100°C) storage modulus of ABS (1298 MPa) in the nanocomposites was increased to 1696 MPa in presence of 0.64 wt % of the MWCNT. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Delineation of ECG characteristic features using multiresolution wavelet analysis method

A discrete wavelet transform (DWT) based feature extraction technique in the QT segment of digitized electrocardiograph recordings is proposed. At first, the signal is denoised by decomposing it using DWT technique and discarding the coefficients corresponding to the noise components. A multiresolution approach along with an adaptive thresholding is used for the detection of R-peaks. Then Q, S peak, QRS onset and offset points are identified. Finally, the T wave is detected. By detecting the baseline of the ECG data, height of R, Q, S and T wave are calculated. For R-peak detection, proposed algorithm yields sensitivity and positive predictivity of 99.8% and 99.6% respectively with MIT BIH Arrhythmia database, 99.84% and 99.98% respectively with PTB diagnostic ECG database. For time plane features, an average coefficient of variation of 3.21 is obtained over 150 leads tested from PTB data, each with 10,000 samples.     

Antioxidant effects of broccoli powder extract in goat meat nuggets

The antioxidant potential of broccoli powder extract (BPE) was determined and evaluated in goat meat nuggets at three different levels 1, 1.5 and 2%, compared with control and butylated hydroxyl toluene (100ppm BHT). Total phenolics in 5mg broccoli powder was higher (P<0.05) than 100ppm BHT. Free radical scavenging activity of 2.25mg and 3mg broccoli powder was found similar to 50 and 100ppm BHT. Reducing power of 10mg broccoli powder was comparable to the 100ppm BHT. Incorporation of 1.5 and 2% BPE decreased (P<0.05) the pH value of the products. Total phenolics in product with 2% BPE was similar to BHT nuggets. Chroma value of products with 1.5 and 2% BPE was lower (P<0.05) than control and BHT nuggets. Thiobarbituric acid reactive substances number of BPE nuggets was lower (P<0.05) than control throughout the storage. Thus 2% BPE can be used as natural antioxidant in goat meat nuggets without affecting product acceptability.     

Supported ionic liquid membranes for removal of dioxins from high-temperature vapor streams

Dioxins and dioxin-like chemicals are predominantly produced by thermal processes such as incineration and combustion at concentrations in the range of 10-100 ng of I-TEQ/kg (I-TEQ = international toxic equivalents). In this work, a new approach for the removal of dioxins from high-temperature vapor streams using facilitated supported ionic liquid membranes (SILMs) is proposed. The use of ceramic membranes containing specific ionic liquids, with extremely low volatility, for dioxin removal from incineration sources is proposed owing to their stability at very high temperatures. Supported liquid membranes were prepared by successfully immobilizing the ionic liquids tri-C(8)-C(10)-alkylmethylammonium dicyanamide ([Aliquat][DCA]) and 1-n-octyl-3-methylimidazolium dicyanamide ([Omim][DCA]) inside the porous structure of ceramic membranes. The porous inorganic membranes tested were made of titanium oxide (TiO(2)), with a nominal pore size of 30 nm, and aluminum oxide (Al(2)O(3)), with a nominal pore size of 100 nm. The ionic liquids were characterized, and the membrane performance was assessed for the removal of dioxins. Different materials (membrane pore size, type of ionic liquid, and dioxin) and different operating conditions (temperature and flow rate) were tested to evaluate the efficiency of SILMs for dioxin removal. All membranes prepared were stable at temperatures up to 200 °C. Experiments with model incineration gas were also carried out, and the results obtained validate the potential of using ceramic membranes with immobilized ionic liquids for the removal of dioxins from high-temperature vapor sources.     

Instrumental testing of tea by combining the responses of electronic nose and tongue

In the tea industry, experienced tea tasters are employed for evaluation of tea quality and gradation of tea is done on the basis of their scores. This subjective method of assessment has numerous problems like inaccuracy and non-repeatability. Electronic nose and electronic tongue systems are recently being used for measurement of odor and taste of tea samples. As the senses of smell and taste are not independent, and both are interacting, the measured data from the individual systems are combined in this paper for improved estimation of black tea quality. It is found that for the combined system, both the clustering and classification rates improve when compared to the individual systems. With radial basis function neural network, the classification rate increases up to 93%, whereas with the independent systems, the classification rate obtained is 83–84% with electronic nose and 85–86% with electronic tongue.     

Quality characteristics of low-fat chicken nuggets: effect of common salt replacement and added bottle gourd (Lagenaria siceraria L.)

BACKGROUND: There is growing demand for the meat products having healthier characteristics. In an endeavour to develop low‐salt, low‐fat and high‐fibre chicken nuggets an investigation was carried out to observe the effects of partial replacement (40%) of sodium chloride in pre‐standardised low‐fat chicken nuggets (Control, 20 g kg^?1 NaCl) with a salt substitute blend as well as incorporation of bottle gourd (Lagenaria siceraria L.) in the resulting low‐salt, low‐fat products at three different levels, i.e. 50, 75 and 100 g kg^?1 (Treatments, 12 g kg^?1 NaCl) on the various quality attributes. RESULTS: Sodium chloride replacement decreased (P < 0.01) emulsion and product pH, cooking yield, moisture, ash, yellowness, hue value and textural properties. pH values, moisture and dietary fibre increased (P < 0.01) while cooking yield, % protein, textural properties and total cholesterol were decreased with the incorporation of bottle gourd in low‐salt, low‐fat nuggets. Sensory attributes of the product were not affected with salt replacement; however, inclusion of bottle gourd at higher levels decreased (P < 0.05) flavour and texture scores. CONCLUSION: The results suggest that low‐salt, low‐fat and high‐fibre chicken nuggets can be developed with the use of a salt substitute blend and bottle gourd without affecting their acceptability. Copyright © 2012 Society of Chemical Industry     

Vacuum system of SST-1 Tokamak

Vacuum chambers of Steady State Superconducting (SST-1) Tokamak comprises of the vacuum vessel and the cryostat. The plasma will be confined inside the vacuum vessel while the cryostat houses the superconducting magnet systems (TF and PF coils), LN₂ cooled thermal shields and hydraulics for these circuits. The vacuum vessel is an ultra-high (UHV) vacuum chamber while the cryostat is a high-vacuum (HV) chamber. In order to achieve UHV inside the vacuum vessel, it would be baked at 150 °C for longer duration. For this purpose, U-shaped baking channels are welded inside the vacuum vessel. The baking will be carried out by flowing hot nitrogen gas through these channels at 250 °C at 4.5 bar gauge pressure. During plasma operation, the pressure inside the vacuum vessel will be raised between 1.0 × 10^?4 mbar and 1.0 × 10^?5 mbar using piezoelectric valves and control system. An ultimate pressure of 4.78 × 10^?6 mbar is achieved inside the vacuum vessel after 100 h of pumping. The limitation is due to the development of few leaks of the order of 10^?5 mbar l/s at the critical locations of the vacuum vessel during baking which was confirmed with the presence of nitrogen gas and oxygen gas with the ratio of ～3.81:1 indicating air leak. Similarly an ultimate vacuum of 2.24 × 10^?5 mbar is achieved inside the cryostat. Baking of the vacuum vessel up to 110 °C with ±10 °C deviation was achieved with a net mass flow rate of 0.8 kg/s at 1.5 bar gauge inlet pressure and supply temperature of 230 °C at the heater end. Also during gas feed system installation, the pressure inside the VV was raised from 3.01 × 10^?5 mbar to 1.72 × 10^?4 mbar by triggering a pulse of lower amplitude of 25 voltage direct current (VDC) for 100 s to piezoelectric valve. This paper describes in detail the design and implementation of the various vacuum subsystems including relevant experimental results.     

Invariant density analysis: modeling and analysis of the postural control system using Markov chains

In this paper, a novel analysis technique, invariant density analysis (IDA), is introduced. IDA quantifies steady-state behavior of the postural control system using center of pressure (COP) data collected during quiet standing. IDA relies on the analysis of a reduced-order finite Markov model to characterize stochastic behavior observed during postural sway. Five IDA parameters characterize the model and offer physiological insight into the long-term dynamical behavior of the postural control system. Two studies were performed to demonstrate the efficacy of IDA. Study 1 showed that multiple short trials can be concatenated to create a dataset suitable for IDA. Study 2 demonstrated that IDA was effective at distinguishing age-related differences in postural control behavior between young, middle-aged, and older adults. These results suggest that the postural control system of young adults converges more quickly to their steady-state behavior while maintaining COP nearer an overall centroid than either the middle-aged or older adults. Additionally, larger entropy values for older adults indicate that their COP follows a more stochastic path, while smaller entropy values for young adults indicate a more deterministic path. These results illustrate the potential of IDA as a quantitative tool for the assessment of the quiet-standing postural control system.     

Hybrid n-GaN and polymer interfaces: Model systems for tunable photodiodes

Hybrid optoelectronic device structures offer promising options for a wide range of properties. The functioning of hybrid-bilayer devices is largely determined by their interface. Hybrid-bilayer devices based on wide band gap gallium nitride (GaN) and low band-gap donor/acceptor polymers offer a unique combination and model interface systems for application in photodetectors. A systematic study of the optoelectronic properties, specifically the photocurrent as a function of voltage bias and incident wavelength, has been carried out for n-Gan/polymer bilayer structures. A clear evidence of interface polarization originating from the GaN surface manifests in the current–voltage characteristics and photocurrent response of the hybrid structure.