Engineering topics
Manatt, K.
Publications and source records attributed to Manatt, K..
Use of the JPL Electronic Nose to detect leaks and spills in an enclosed environment
An electronic nose to be used as an air quality monitor in human habitats in space has been developed at the Jet Propulsion Laboratory. This device is capable of detecting, identifying and quantifying several organic and inorganic chemical species which might be present as contaminants in spacecraft air. The complete portable device, including sensors, electronics, and software for data analysis, has been extensively tested.
Developing sensor activity relationships for the JPL electronic nose sensors using molecular modeling and QSAR techniques
We report a Quantitative Structure-Activity Relationships (QSAR) study using Genetic Function Approximations (GFA) to describe the polymer-carbon composite sensor activities in the JPL Electronic Nose, when exposed to chemical vapors at parts-per-million concentration levels.
Correlating electronic nose sensor response for air-quality monitoring: an experimental and modeling study
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Temperature effects on polymer-carbon composite sensors
At JPL we have investigated the effects of temperature on polymer-carbon black composite sensors. While the electrical properties of polymer composites have been studied, with mechanisms of conductivity described by connectivity and tunneling, it is not fully understood how these properties affect sensor characteristics and responses.
Using temperature effects on polymer-composite sensor arrays to identify analytes
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NMP environmental monitor: preliminary design concept
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Temperature effects on polymer-carbon composite sensors: evaluating the role of polymer molecular weight and carbon loading
We report the effect of environmental condtions coupled with varying polymer properties and carbon loadings on the performance of polymer-carbon black composite film, used as sensing medium in the JPL Electronic Nose.
Molecular modeling of interactions in electronic nose sensors for environmental monitoring in aerospace applications
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Molecular modeling of interactions in electronic nose sensors for environmental monitoring
We report a study aimed at understanding analyte interactions with sensors made from polymer-carbon black composite films. The sensors are used in an Electronic Nose (ENose) which is used for monitoring the breathing air quality in human habitats. The model mimics the experimental conditions of the composite film deposition and formation and was developed using molecular modeling and simulation tools. The Dreiding 2.21 Force Field was used for the polymer and analyte molecules while graphite parameters were assigned to the carbon black atoms. The polymer considered for this work is methyl vinyl ether / maleic acid copolymer. The target analytes include both inorganic (NH3) and organic (methanol) types of compound. Results indicate different composite-analyte interaction behavior.
Molecular modeling of polymer composite interactions with analytes in electronic nose sensors for environmental monitoring in International Space Station
We report a molecular modeling study to investigate the polymer-carbon black (CB) composite-analyte interactions in resistive sensors. These sensors comprise the JPL Electronic Nose (ENose) sensing array developed for monitoring breathing air in human habitats. The polymer in the composite is modeled based on its stereisomerism and sequence isomerism, while the CB is modeled as uncharged naphthalene rings (with no hydrogens). The Dreiding 2.21 force field is used for the polymer and solvent molecules and graphite parameters are assigned to the carbon black atoms. A combination of molecular mechanics (MM) and molecular dynamics (NPT-MD and NVT-MD) techniques are used to obtain the equilibrium composite structure by inserting naphthalene rings in the polymer matrix. Polymers considered for this work include poly(4- vinylphenol), polyethylene oxide, and ethyl cellulose. Analytes studied are representative of both inorganic (ammonia) and organic (methanol, toluene, hydrazine) compounds. The results are analyzed for the composite microstructure by calculating the radial distribution profiles as well as for the sensor response by predicting the interaction energies of the analytes with the composites.
Molecular modeling of polymer composite interactions with analytes in electronic nose sensors for environmental monitoring in International Space Station
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Environmental monitoring by electronic nose sensors: a molecular modeling study
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Toward a second generation electronic nose at JPL: sensing film optimization studies
Development of a second generation Electronic Nose at JPL is focusing on optimization of the sensing films to increase sensitivity and optimization of the array.
Reactivity of thin metal films on sodium beta alumina ceramic in high temperature, low pressure sodium vapor
Electrochemical techniques including impedance spectroscopy are routinely used to test the performance of AMTEC electrodes.
Mathematical modeling of the impedance of single and multi-tube AMTEC units
AMTEC power systems are designed for use on extended space missions. During the lifetime of such missions the power available for the spacecraft will depend on the degradation of the system performance. Development of a tool that allows monitoring of the system degradation will provide an aid in dtermining the condition of the power source.
Application of a Fundamental Model of the Exchange Current to Performance of Titanium Nitride, Rhodium-Tungsten, and Molybdenum Electrodes in the Alkali Metal Thermal-to-Electric Converter
AMTEC cells are under development as power resources for future outer planetary robotic space missions, where they must operate for very long times.
Slow Reversible and Quasi-Reversible Performance Changes in AMTEC Electrodes and Electrolytes
This paper reports several slow reversible and quasi-reversible processes which occur in the porous electrode/solid electrolyte combination at AMTEC operating temperatures.