Quantifying the travel times, pathways, and dispersion of solutes moving through stream environments is critical for understanding the biogeochemical cycling processes that control ecosystem functioning. Validation of stream solute transport and exchange process models requires data obtained from in-stream measurement of chemical concentration changes through time. This can be expensive and tim...

Highly orientated polypyrrole (PPy)-coated polyacrylonitrile (PAN) (PPy-PAN) nanofiber yarn was prepared with an electrospinning technique and in-situ chemical polymerization. The morphology and chemical structure of PPy-PAN nanofiber yarn was characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and fou...

A novel wearable electronic nose for armpit odor analysis is proposed by using a low-cost chemical sensor array integrated in a ZigBee wireless communication system. We report the development of a carbon nanotubes (CNTs)/polymer sensor array based on inkjet printing technology. With this technique both composite-like layer and actual composite film of CNTs/polymer were prepared as sensing layer...

A carbon-paste electrode (CPE) chemically modified with the N-4,4'-azodianiline(ferrocenyl Schiff base) complex and multi wall carbon nanotubes (ADAFCNTE) was used as a highly sensitive electrochemical sensor for determination of trace amounts of atenolol. The oxidation peak potentials in cyclic voltammogram of ADAFCNTE occurred around 550 mV vs Ag/AgCl (at pH 6.0) while this peak potential at ...

Target factor analysis is an important issue in the analysis of sensor array data as it allows to test whether measurements contain only the substances a chemical sensor system was calibrated with. In this paper a new approach based on the properties of random matrices is presented. The problem is rst transformed to a pseudorank estimation problem by forming a combined calibration-prediction da...

a carbon-paste electrode (cpe) chemically modified with the n-4,4'-azodianiline(ferrocenyl schiff base) complex and multi wall carbon nanotubes (adafcnte) was used as a highly sensitive electrochemical sensor for determination of trace amounts of atenolol. the oxidation peak potentials in cyclic voltammogram of adafcnte occurred around 550 mv vs ag/agcl (at ph 6.0) while this peak potentia...

This paper addresses the need for a broad-base signal conditioning module designed to process chemical sensor signals in such a way that the output of the conditioning circuits ensures similar baseline and dynamic range, regardless of fabrication variation and sensor drift. These baseline compensation circuits are demonstrated in the context of processing resistance changes from composite polym...

Chemical sensing of explosives may allow differentiation between mines and other mine-like objects, especially if close proximity to the targets can be achieved. Robotic crawlers are well suited to achieve the required proximity and have added advantages, including stability on the bottom and station-keeping. We have performed initial tests with an explosive sensor mounted on crawlers and two t...

Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sen...

This article presents a simple version of Integrated Sensing and Processing (ISP) for statistical pattern recognition wherein the sensor measurements to be taken are adaptively selected based on task-specific metrics. Thus the measurement space in which the pattern recognition task is ultimately addressed integrates adaptive sensor technology with the specific task for which the sensor is emplo...