Investigation of optical and thermally stimulated properties of SiO2 nanoparticles‐filled polycarbonate

Polycarbonate nanocomposite containing silicon oxide nanoparticles average size of 5 nm at different weight ratio has been prepared by solution mixing method. The dispersion of nanoparticles in polymer matrix was studied by transmission electron microscopy (TEM). The optical and thermally stimulated behavior of nanocomposites were analyzed by energy dispersive X‐ray spectra (EDX), X‐ray diffraction pattern (XRD), UV–vis spectroscopy, differential scanning calorimetry (DSC), and thermally stimulated discharge current (TSDC). TEM images show the dispersion and size of the nanoparticles, however, EDX indicate the presence of SiO₂ on the surface of the nanocomposite film. An XRD result reveals that the crystallinity increases with increase in concentration of SiO₂ nanoparticles in polymer matrix. The direct and indirect optical energy band gaps decreased and number of carbon atom increased with concentration of SiO₂ nanoparticles. We have observed that the increase of SiO₂ nanoparticles in PC significantly reduces the refractive index. DSC and TSDC show that glass transition temperature increases according to SiO₂ weight ratio. The TSDC of nanocomposites samples could be understand in terms of non‐Debye theory of charge relaxation and co‐tunneling mechanism of charge transport. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

A study on the performance and emission of a diesel engine fueled with Jatropha biodiesel oil and its blends

Biodiesel either in neat form or as a mixture with diesel fuel is widely investigated to solve the twin problem of depletion of fossil fuels and environmental degradation. The main objective of the present study is to compare performance, emission and combustion characteristics of biodiesel derived from non edible Jatropha oil in a dual fuel diesel engine with base line results of diesel fuel. The performance parameters evaluated were: brake thermal efficiency, brake specific fuel consumption, power output. As a part of combustion study, in-cylinder pressure, rate of pressure rise and heat release rates were evaluated. The emission parameters such as carbon monoxide, carbon dioxide, un-burnt hydrocarbon, oxides of nitrogen and smoke opacity with the different fuels were also measured and compared with base line results. The different properties of Jatropha oil after transestrification were within acceptable limits of standards as set by many countries. The brake thermal efficiency of Jatropha methyl ester and its blends with diesel were lower than diesel and brake specific energy consumption was found to be higher. However, HC, CO and CO₂ and smoke were found to be lower with Jatropha biodiesel fuel. NO_x emissions on Jatropha biodiesel and its blend were higher than Diesel. The results from the experiments suggest that biodiesel derived from non edible oil like Jatropha could be a good substitute to diesel fuel in diesel engine in the near future as far as decentralized energy production is concerned. In view of comparable engine performance and reduction in most of the engine emissions, it can be concluded and biodiesel derived from Jatropha and its blends could be used in a conventional diesel engine without any modification.     

Hybrid Nanoscale Architecture for Enhancement of Antimicrobial Activity: Immobilization of Silver Nanoparticles on Thiol‐Functionalized Polymer Crystallized on Carbon Nanotubes

We describe here the synthesis and antimicrobial activity of an innovative nanohybrid system, characterized by attachment of silver nanoparticles (AgNPs) to the thiol‐functionalized polymer that was periodically crystallized on carbon nanotubes (CNTs). The synthesis of the nanohybrid architecture first involved direct crystallization of thiol‐functionalized copolymer along the long axis of CNTs, followed by attachment of AgNPs to the thiol‐group of functionalized copolymer. The antimicrobial activity was assessed in terms of interaction with Escherichia coli, where the constituents of the nanohybrid structure play a synergistic role. The antimicrobial activity was approximately four orders of magnitude greater than the ex situ precipitated bare AgNPs. Possible mechanisms underlying enhanced antimicrobial activity are discussed. The study underscores the potential of uniquely combining CNTs and biopolymers for biomedical applications, in the present case, antimicrobial activity.     

Adaptive Neural Fuzzy Inference System for the Detection of Inter-Turn Insulation and Bearing Wear Faults in Induction Motor

The positive features of neural networks and fuzzy logic are combined together for the detection of stator inter-turn insulation and bearing wear faults in single-phase induction motor. The adaptive neural fuzzy inference systems (ANFISs) are developed for the detection of these two faults. These faults are created experimentally on a single-phase induction motor in the laboratory. The experimental data is generated for the five measurable parameters, viz, motor intakes current, speed, winding temperature, bearing temperature, and the noise of the machine. Earlier, the ANFIS fault detectors are trained for the two input parameters, i.e., speed and current, and the performance is tested. Later, the three remaining parameters are added and the five input ANFIS fault detector is trained and tested. It observed from the simulation results that the five input parameter system predicts more accurate results     

Gamma Radiation-Induced Graft Copolymerization of Acrylonitrile Onto Sodium Salt of Partially Carboxymethylated Amylose

The graft copolymerization of acrylonitrile onto Sodium salt of Partially Carboxymethylated Amylose (Na-PCMA, DA=0.313) in aqueous and in water: methanol mixed solvents system has been studied using gamma rays from Co⁶⁰ source as a means of initiation by the mutual method. The optimum condition for affording maximum percentage of grafting of acrylonitrile onto Na-PCMA has been obtained by varying different reaction parameters such as total dose, monomer concentration, amount of water and composition of solvents system. The mechanism of grafting has been postulated. The resulting graft copolymer has been characterized by chemical, spectroscopic, thermogravimetric and scanning electron microscopic methods.     

Statistical evaluation of hyperbaric filtration for fine coal dewatering

A statistical design of parametric study of pressure filtration for fine coal dewatering is presented. The effects of five major parameters of the dewatering, i.e. applied pressure, filtration time, cake thickness, solids concentration and slurry pH, on cake moisture reduction and air consumption were investigated. The study was conducted starting with two level factorial experiments to identify the most significant parameters, and concluding with response surface methodologies to establish an optimum operating condition for the dewatering of fine coal. It was observed that applied pressure, cake thickness and filtration time were identified to be the key operating variables for reduction of filter cake moisture as well as air consumption. With the key parameters, an optimum condition for the dewatering was determined to be an applied pressure of 93 psi with a cake thickness of 2.5 cm and a filtration time of 4.8 minutes for the laboratory filtration system. At these optimum conditions the filter cake containing about 22 percent moisture by weight and consuming air by 4.1 m³/(m²·min·kg) on dry solid basis was obtained.     

A software supported image enhancement approach based on DCT and quantile dependent enhancement with a total control on enhancement level

Multimedia Tools and Applications - In many computer vision applications like medical imaging, pattern recognition etc., image enhancement is an important pre-processing requirement which is used...