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Verma M.L.,Shri Shankaracharya Group of Institutions | Minakshi M.,Murdoch University | Singh N.K.,Shri Shankaracharya Institute of Engineering and Technology
Electrochimica Acta

This paper describes the synthesis and characterization of a new silver ion conducting solid polymer electrolyte based on activated carbon. Solid nanocomposite polymer electrolytes and their application in energy storage devices has been widely studied because of their environmental safe, no leakage and ion transport mechanism directly connected with the salt (silver iodide) used. Aqueous and non-aqueous electrolytes are widely used in electronic devices but have numerous limitations such as volatility, flammability and leakage. Therefore, we have developed all solid state capacitor in this report and used polymer electrodes and electrolyte as the host. A solid polymer electrode of type 1-x (70 polyethylene oxide: 30 silver iodide): x activated carbon (where x = 10 ≤ x ≤ 50 wt.%) composites have been synthesized using hot press method. The ionic conductivity has been significantly improved for the optimum amount (30 wt.%) of the activated carbon added into the polymer host. The performance of the synthesized electrodes is studied by various physical and electrochemical methods. The leakage current and self-discharge characteristics of the solid state capacitor device have been reported. © 2014 Elsevier Ltd. Source

Verma M.L.,Shri Shankaracharya Group of Institutions | Minakshi M.,Murdoch University | Singh N.K.,Shri Shankrachayra Institute of Engineering and Technology
Industrial and Engineering Chemistry Research

This report describes the structural and electrochemical properties of the nanocomposite polymer electrolyte (70PEO:30AgI) incorporating SiO2 filler of different weight percentage (wt %) ranging between 1 and 10 wt %. Studies on inorganic filler in polymer matrix may be quite familiar, but the chosen polymer, the effect of concentration exhibiting the highest conductivity, and its use for capacitor studies are novel and are studied with the aid of impedance spectroscopy. The optimum composite composition (OCC) of 5 wt % loading, 95(70PEO:30AgI):5SiO2, exhibited the best performance of conductivity (σ ∼ 2.50 × 10-3 S/cm) and a low activation energy of 0.1 eV. The impedance, capacitive, and other structural behavior of the polymer electrolyte validated the proposed conceptual idea. The conductivity enhancement has been well-correlated with the change in structure and morphology of the polymer electrolyte, suggesting that the amorphous domain is found to be suitable for solid-state capacitor applications. © 2014 American Chemical Society. Source

Patel B.C.,Shri Shankaracharya Group of Institutions | Sinha G.R.,Shri Shankaracharya Group of Institutions
Proceedings - International Conference on Electronic Systems, Signal Processing, and Computing Technologies, ICESC 2014

This paper introduces a novel approach for accomplishing mammographic feature analysis through detection of tumor, in terms of their size and shape with experimental work for early breast tumor detection. The objective is to detect the abnormal tumor/tissue inside breast tissues using three stages: Preprocessing, Segmentation and post processing stage. By using preprocessing noise are remove and than segmentation is applied to detect the mass, after that post processing is applied to find out the benign and malignant tissue with the affected area in the cancers breast image. Size of tumor is also detected in these steps. The occurrences of cancer nodules are identified clearly. Compared with an expert observer reading the Mammography, our algorithm achieves 96.5% sensitivity, 89% specificity, 95.6% accuracy value. © 2014 IEEE. Source

Verma M.L.,Shri Shankaracharya Group of Institutions | Rao B.K.,Shri Shankaracharya Group of Institutions

For the study of transport properties of a nano-composite material, an open circuit condition of current is considered, where the sum of diffusion current density, displacement current density, ohmic current density, and excess charge current density is vanished. Including the effects of drift and trapping of ions, drift and trapping diffusion coefficients are modeled respectively and the significance of the type of ionic motion in the study of ionic diffusion is discussed. © 2013 Springer-Verlag Berlin Heidelberg. Source

Goel N.,Shri Shankaracharya Group of Institutions | Patel R.N.,Shri Shankaracharya Group of Institutions | Chacko S.,Shri Shankaracharya Group of Institutions
International Journal of Power Electronics and Drive Systems

In recent years an advanced control method called direct torque control (DTC) has gained importance due to its capability to produce fast torque control of induction motor. Although in these systems such variables as torque, flux modulus and flux sector are required, resulting DTC structure is particularly simplistic. Conventional DTC does not require any mechanical sensor or current regulator and coordinate transformation is not present, thus reducing the complexity. Fast and good dynamic performances and robustness has made DTC popular and is now used widely in all industrial applications. Despite these advantages it has some disadvantages such as high torque ripple and slow transient response to step changes during start up. Torque ripple in DTC is because of hysteresis controller for stator flux linkage and torque. The ripples can be reduced if the errors of the torque and the flux linkage and the angular region of the flux linkage are subdivided into several smaller subsections. Since the errors are divided into smaller sections different voltage vector is selected for small difference in error, thus a more accurate voltage vector is selected and hence the torque and flux linkage errors are reduced. The stator resistance changes due to change in temperature during the operation of machine. At high speeds, the stator resistance drop is small and can be neglected. At low speeds, this drop becomes dominant. Any change in stator resistance gives wrong estimation of stator flux and consequently of the torque and flux. Therefore, it is necessary to estimate the stator resistance correctly. This paper aims to review some of the control techniques of DTC drives and stator resistance estimation methods. © 2015, Institute of Advanced Engineering and Science. All rights reserved. Source

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