High input impedance voltage‐mode first‐order all‐pass sections

This paper proposes six new first‐order voltage‐mode all‐pass sections (VM‐APSs) based on three general topologies. Each circuit uses two differential voltage current conveyors and three grounded passive components. All the circuits possess high input impedance and easy control of pole frequency either by a simple matching of resistors (two equal‐valued resistors) for the three canonical circuits or by a single resistor for three non‐canonical circuits. PSPICE simulation results using real device 0.5µ CMOS parameters are given to validate the proposed circuits. Copyright © 2007 John Wiley & Sons, Ltd.     

Modeling the performance of molten carbonate based direct carbon fuel cell anode

A mathematical model is developed to study the performance of a molten carbonate based direct carbon fuel cell anode. The direct carbon fuel cell(DCFC) is a fuel cell which uses solid carbon as fuel and molten carbonate as electrolyte. The model assumes that the 4 electron carbon oxidation reaction is the primary reaction driving the DCFC. However, the 2 electron CO oxidation reaction and the reverse Boudouard reaction is also considered in this model. The model studies the effect of performance parameters on the performance of the DCFC. The effect of the bulk conductivity in the solid phase, the bulk conductivity in the liquid phase, carbon loading and the thickness of the anode layer on the potential and current distribution in the cell is modeled. Model results are compared with experimental data and found to compare well.     

Inhibition of melanosis formation in Pacific white shrimp by the extract of lead (Leucaena leucocephala) seed

Lead (Leucaena leucocephala) seed extract was prepared using distilled water as a medium. An extraction yield of 26.16 g/100 g of seed was obtained after extraction at room temperature for 12 h. Total phenolic and mimosine contents in the lead seed extract powder (LSEP) were 17.4 g GAE/100 g and 8.8 g/100 g, respectively. LSEP at different concentrations (0.05%, 0.1%, 0.25%, 0.5%, and 1%, w/v) showed inhibitory activity towards polyphenoloxidase (PPO) of Pacific white shrimp in a dose dependent manner. When the whole Pacific white shrimp were treated with 0.25% and 0.5% (w/v) LSEP, the shrimp treated with 0.5% LSEP had the lower melanosis score throughout the storage of 12 days and showed a higher score for colour and odour, as well as overall likeness, compared with the control (without treatment) and 1.25% sodium metabisulphite treated samples at day 12 (P < 0.05). Meat of shrimps treated with LSEP at both levels had the increase in mimosine content up to 8 days, suggesting the migration of mimosine into shrimp muscle during extended storage. Therefore, 0.5% LSEP can be used as a novel melanosis inhibitor for Pacific white shrimp.     

Electronic Structure Engineered Heteroatom Doped All Transition Metal Sulfide Carbon Confined Heterostructure for Extrinsic Pseudocapacitor

Ultra-high energy density battery-type materials are promising candidates for supercapacitors (SCs); however, slow ion kinetics and significant volume expansion remain major barriers to their practical applications. To address these issues, hierarchical lattice distorted α-/γ-MnS@Co_xS_y core-shell heterostructure constrained in the sulphur (S), nitrogen (N) co-doped carbon (C) metal-organic frameworks (MOFs) derived nanosheets (α-/γ-MnS@Co_xS_y@N, S C) have been developed. The coordination bonding among Co_xS_y, and α-/γ-MnS nanoparticles at the interfaces and the π–π stacking interactions developed across α-/γ-MnS@Co_xS_y and N, S C restrict volume expansion during cycling. Furthermore, the porous lattice distorted heteroatom-enriched nanosheets contain a sufficient number of active sites to allow for efficient electron transportation. Density functional theory (DFT) confirms the significant change in electronic states caused by heteroatom doping and the formation of core-shell structures, which provide more accessible species with excellent interlayer and interparticle conductivity, resulting in increased electrical conductivity. . The α-/γ-MnS@Co_xS_y@N, S C electrode exhibits an excellent specific capacity of 277 mA hg⁻¹ and cycling stability over 23 600 cycles. A quasi-solid-state flexible extrinsic pseudocapacitor (QFEPs) assembled using layer-by-layer deposited multi-walled carbon nanotube/Ti₃C₂T_X nanocomposite negative electrode. QFEPs deliver specific energy of 64.8 Wh kg⁻¹ (1.62 mWh cm⁻³) at a power of 933 W kg⁻¹ and 92% capacitance retention over 5000 cycles.     

Effect of nanoclay on the morphology and properties of acrylonitrile butadiene styrene toughened polyoxymethylene (POM)/clay nanocomposites

Here, we report the morphology and properties of melt‐blended poly(acrylonitrile‐butadiene‐styrene) (ABS) toughened polyoxymethylene (POM)/clay nanocomposites at different clay loadings (2.5 and 5 phr). The number average domain diameter (D_n) of the ABS droplets in the (75/25 w/w) POM/ABS blend was gradually decreased with increase in clay loading. The X‐ray diffraction (XRD) study and transmission electron microscopic (TEM) analysis of the (75/25 w/w) POM/ABS/clay nanocomposites revealed that, the major amount of clay silicates was dispersed selectively in the POM phase of the blend with an exfoliated morphology. The thermal stability of the (75/25 w/w) POM/ABS blend was increased with the increase in clay loadings. Differential scanning calorimetry (DSC) study suggested the enhancement in the non‐isothermal crystallization temperature of the matrix polymer in the blend/clay nanocomposites. The rheological study revealed a shear thinning behavior in the nanocomposites indicating good processability of the nanocomposites. The solvent uptake property of the blend was decreased in the presence of small amount of the clay in the nanocomposites. The tensile strength and Young modulus of the (75/25 w/w) POM/ABS blend were increased, whereas, percent elongation of the blend was decreased with increasing the clay content. The toughening effect of the ABS was prominent in the POM/ABS/clay nanocomposites compared to the pristine polymer. POLYM. COMPOS., 35:273–282, 2014. © 2013 Society of Plastics Engineers     

Assessment criteria for solar cooling systems

Solar cooling systems should be able simultaneously to generate refrigeration and save conventional energy. An assessment of the potential of various cooling systems as refrigerators and energy savers is presented in the paper. For this purpose, a solar cooling system has been considered as a combination of an energy conversion and a refrigeration subsystem. Overall efficiencies of the various solar cooling systems are defined for direct quantitative comparison of different systems.     

Radial basis probabilistic neural network for differential protection of power transformer

Protection of medium- and large-power transformers has always remained an area of interest of relaying engineers. Conventionally, the protection is done making use of magnitude of various frequency components in differential current. A novel technique to distinguish between magnetising inrush and internal fault condition of a power transformer based on the difference in the current wave shape is developed. The proposed differential algorithm makes use of radial basis probabilistic neural network (RBPNN) instead of the conventional harmonic restraint- based differential relaying technique. A comparison of performance between RBPNN and heteroscedastic-type probabilistic neural network (PNN) is made. The optimal smoothing factor of heteroscedastic-type PNN is obtained by particle swarm optimisation technique. The results demonstrate the capability of RBPNN in terms of accuracy with respect to classification of differential current of the power transformer. For the verification of the developed algorithm, relaying signals for various operating conditions of the transformer, including internal faults and external faults, were obtained through PSCAD/EMTDC. The proposed algorithm has been implemented in MATLAB.     

Extraction and Isolation of β‐Glucan from Grain Sources—A Review

A collective report on the extraction and isolation of β‐glucan from grain sources, namely, oat, barley, and wheat is presented. An analysis on the effect of medium, pH, and temperature on the purity and yield of the β‐glucan derived under acidic/alkaline/aqueous/enzymatic conditions is also made. Water extraction and alkali extraction processes are preferred as the yield and recovery of extracted β‐glucan were good. Cost‐effective development of the process for deriving high molecular weight β‐glucan is the current requirement for its wide applications in food and pharmaceutical industries.     

Multidimensional Multi-Attribute Approach to Counter the Routing Attacks on MANET

Wireless Personal Communications - The basic characteristic of a wireless sensor network is to sense the environment and to gather different types of data. It is used in various vital sectors, such...