Showing papers by "Sushabhan Choudhury published in 2010"

Design and Development of Wireless Sensor Node

Abstract: This paper presents design and development of intelligent sensor node for environmental monitoring. The node is equipped with multimode sensors for sensing different environmental parameters, the node can sense four different environmental parameters, light, temperature, humidity, and three different types of gases. The node has half duplex wireless communication feature which is achieved by using an IEEE 802.15.4 standard compliant transceiver. Here we have deployed various intelligent protocols to achieve intelligent power management and precision sensing. The node comes with various error detection and correction capability which enhanced the performance of the node. Two different types of methodology are used to prove the intelligence of the node. The node is equipped with multiple sensors like gas, temperature, and humidity, light. A Special remote system enables user to wirelessly select the particular sensor which provides high wireless hardware flexibility. More priority is given to power consumption and sensing efficiency which is achieved by incorporating various smart tasking and power management protocol. All sensed data are digitized and processed by the internal analog to digital converter (ADC) of a Programmable interface controller (PIC) microcontroller and wirelessly transmitted to the base station for data acquisition and statistical analysis.

Thermoelectric power in ultrathin films, quantum wires and carbon nanotubes under classically large magnetic field: Simplified theory and relative comparison

Abstract: We study the thermoelectric power under classically large magnetic field (TPM) in ultrathin films (UFs), quantum wires (QWs) of non-linear optical materials on the basis of a newly formulated electron dispersion law considering the anisotropies of the effective electron masses, the spin-orbit splitting constants and the presence of the crystal field splitting within the framework of k.p formalism. The results of quantum confined III-V compounds form the special cases of our generalized analysis. The TPM has also been studied for quantum confined II-VI, stressed materials, bismuth and carbon nanotubes (CNs) on the basis of respective dispersion relations. It is found taking quantum confined CdGeAs2, InAs, InSb, CdS, stressed n-InSb and Bi that the TPM increases with increasing film thickness and decreasing electron statistics exhibiting quantized nature for all types of quantum confinement. The TPM in CNs exhibits oscillatory dependence with increasing carrier concentration and the signature of the entirely different types of quantum systems are evident from the plots. Besides, under certain special conditions, all the results for all the materials gets simplified to the well-known expression of the TPM for non-degenerate materials having parabolic energy bands, leading to the compatibility test. (C) 2009 Elsevier B.V. All rights reserved.