Growth of ZnSe∶Mn Nanocrystals from Vapour Phase

ZnSe∶Mn nanocrystals were grown by chemical vapour transport method using the matrix of SiO2 aerogels. The cubic structure of the nanocrystals was confirmed by powder X-ray diffraction (XRD) and electron diffraction (ED) studies. The size of the crystals was observed using transmission electron microscope (TEM). The oxidation state of Mn in ZnSe nanocrystal was found using electron spin resonance (ESR) spectrum. The room temperature luminescence measurements show the peaks corresponding to both bandgap of the material and Mn in ZnSe.     

Synthesis and characterization of liquid crystalline polymers containing aromatic ester mesogen and a nonmesogenic ferrocene unit in the spacer

A new series of liquid crystalline polymers containing aromatic triad ester mesogen and 1,1′‐disubstituted ferrocene as a nonmesogenic unit along with polymethylene spacer was synthesized. The polymer was synthesized by a room temperature polycondensation reaction between bis(4‐chloroformyl phenyloxy alkyl ferrocene dicarboxylate) and quinol. The alkyl groups have been varied by an even number of methylene groups with a range from two to ten groups. All the polymers were found to possess liquid crystalline properties. The identification of the mesophase is more transparent with an increase in the spacer. The thermal characteristics were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results reveal that the thermal stability of the polymers was decreased with increasing spacer length. The T_g, T_m, and T_i of the polymers decreased with increasing methylene groups. The incorporation of the ferrocene moiety also has a considerable effect on the glass transition temperature. The char yield of the polymer decreases with an increasing methylene chain length. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3494–3501, 2002     

Design of observer based nonlinear model predictive controller for a continuous stirred tank reactor

Model predictive control (MPC) schemes are now widely used in process industries for the control of key unit operations. Linear model predictive control (LMPC) schemes which make use of linear dynamic model for prediction, limit their applicability to a narrow range of operation (or) to systems which exhibit mildly nonlinear dynamics.

In this paper, a nonlinear observer based model predictive controller (NMPC) for nonlinear system has been proposed. An approach to design NMPC based on fuzzy Kalman filter (FKF) and augmented state fuzzy Kalman filter (ASFKF) has been presented. The efficacy of the proposed NMPC schemes have been demonstrated by conducting simulation studies on the continuous stirred tank reactor (CSTR). The analysis of the extensive dynamic simulation studies revealed that, the NMPC schemes formulated produces satisfactory performance for both servo and regulatory problems. Simulation results also include an inferential control case, where the reactor concentration is not measured but estimated from temperature measurement and used in the NMPC based on FKF and ASFKF formulations.     

Certain Investigation on Healthcare Monitoring for Enhancing Data Transmission in WSN

International Journal of Wireless Information Networks - Wireless Sensor Networks are often to perform autonomous sensing and controlling the real world objects through the sensor nodes across the...     

Network Lifetime Enhancement of Wireless Sensor Networks Using EFRP Protocol

This paper presents a novel transceiver architecture for in-band full duplex radio. A transceiver for full duplex radio requires a self-interference (SI) canceler to remove the SI occurring from the transmitter to the receiver, and a full duplex transceiver generally has two SI cancelers: one at the analog RF stage and the other at the baseband stage. The output from the SI canceler at the RF stage includes much residual SI, and it decreases the number of bits allocated to the analog baseband signal at the analog-to-digital converter. A 1-tap analog baseband SI canceler that uses a replica signal including only the direct path component of the residual SI has been presented for preventing degradation. However, the architecture cannot remove the SI well due to the high Ricial K-factor. To address the problem, the presented architecture has an SI canceler at the analog baseband stage, and this canceler employs a replica signal that is output from a digital-to-analog converter. Because the replica signal is generated in the digital domain, the architecture can generate a multipath replica signal, and improved performance can be expected. Numerical and theoretical analyses are shown to validate the effectiveness of the presented architecture.

     

Detection of Malicious Profiles and Protecting Users in Online Social Networks

Wireless Personal Communications - Everyone today actively uses online social networks to get in touch with their friends, for career opportunities, and business also. Some of the most popular...     

A design approach for systems based on magnetic pulse compression

A design approach giving the optimum number of stages in a magnetic pulse compression circuit and gain per stage is given. The limitation on the maximum gain per stage is discussed. The total system volume minimization is done by considering the energy storage capacitor volume and magnetic core volume at each stage. At the end of this paper, the design of a magnetic pulse compression based linear induction accelerator of 200 kV, 5 kA, and 100 ns with a repetition rate of 100 Hz is discussed with its experimental results.