We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 μl) in a total volume of ~2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO(3) in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors.

We present an unconventional but high performance pulsating conductivity monitoring instrument constructed by using a new class of sensor, viz., pulsating sensor developed in house. The design consists of a special type of logic gate oscillator (LGO) powered by 5 V direct current (dc). The conductivity cell constitutes a part of LGO. In this conductivity meter the primary signal generated from the sensor is directly in digital domain which is easily transmitted either to a personal computer or to a stand-alone embedded system. Hence it reduces the hardware components making the instrumentation highly simplified. The output of the instrument is pulse frequency which is directly related to the conductivity of solution used for measurement. The relation between pulse frequency and conductivity is determined following a multipoint calibration technique developed in our laboratory using a series of KCl standards. The performance of the instrument is demonstrated with a few examples which reveal the diverse application of this new approach of measurement technique.

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The Network lifetime is an important factor in WSN. This paper proposes a hybrid mechanism called "SUBCLUST" that combines clustering and subset formation. It is observed that randomization while dividing the subsets is not an efficient method to improve the lifetime of WSN. Hence in the proposed scheme during subset formation each sensor's coverage area is assumed to overlap with other sensor. The one with the least area of overlapping is added to the subset to which the current sensor belongs. This process continues until all the sensors are allotted to a particular subset. In order to minimize the energy consumption, scheduling is done in such a way that only one subset of nodes which covers the entire network will remain active at a time and making the remaining subset of nodes to get deactivated. Each subset will be activated one after another to ensure that no event is gone unnoticed. The proposed scheme also uses ARN (Active Routing Nodes) for packet forwarding which minimizes handoff while subset switching occurs. The proposed novel hybrid scheme has been validated using simulation studies and it is observed that the proposed scheme gives better performance than the existing work in terms of network lifetime, network coverage intensity, energy utilization and detection probability.

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