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A High-Speed X-Ray Detector System For Noninvasive Fluid Flow Measurements, Timothy B. Morgan, Benjamin R. Halls, Terrence R. Meyer, Theodore J. Heindel
A High-Speed X-Ray Detector System For Noninvasive Fluid Flow Measurements, Timothy B. Morgan, Benjamin R. Halls, Terrence R. Meyer, Theodore J. Heindel
Terrence R Meyer
The opaque nature of many multiphase flows has long posed a significant challenge to the visualization and measurement of desired characteristics. To overcome this difficulty, X-ray imaging, both in the form of radiography and computed tomography, has been used successfully to quantify various multiphase flow phenomena. However, the relatively low temporal resolution of typical X-ray systems limit their use to moderately slow flows and time-average values. This paper discusses the development of an X-ray detection system capable of high-speed radiographic imaging that can be used to visualize multiphase flows. Details of the hardware will be given and then applied to …
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Joan Carletta
We present the design, fabrication and testing of a microfluidic multichannel resistive pulse sensor for high throughput counting of microparticles. The high throughput counting results from using multiple parallel microfluidic channels to analyze the sample. Detection is achieved by using frequency division multiplexing where a known and unique frequency is applied to modulate each microchannel and a combined measurement is made across a single pair of electrodes. Testing results using 30μm polystyrene particles demonstrate that the throughput of the multiplexed device is improved 300% over a single channel device. In addition, the AC modulation method reduces the polarization effect on …
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Dr. Jiang Zhe
We present the design, fabrication and testing of a microfluidic multichannel resistive pulse sensor for high throughput counting of microparticles. The high throughput counting results from using multiple parallel microfluidic channels to analyze the sample. Detection is achieved by using frequency division multiplexing where a known and unique frequency is applied to modulate each microchannel and a combined measurement is made across a single pair of electrodes. Testing results using 30μm polystyrene particles demonstrate that the throughput of the multiplexed device is improved 300% over a single channel device. In addition, the AC modulation method reduces the polarization effect on …
Optimization Of Threshold Values For Estimators Based On Single-Bit Quantized Sensors Using Genetic Algorithms, Nishant Unnikrishnan, Ajay Mahajan, Antonios Mengoulis, R. Viswanathan
Optimization Of Threshold Values For Estimators Based On Single-Bit Quantized Sensors Using Genetic Algorithms, Nishant Unnikrishnan, Ajay Mahajan, Antonios Mengoulis, R. Viswanathan
Dr. Ajay Mahajan
The paper considers the problem of signal parameter estimation using a collection of distributed sensors called a sensor pack. Each sensor quantizes its data to one-bit information and sends it to a fusion processor for the estimation of the parameter. Estimation of a constant signal in additive noise is considered. Estimators are formulated based on one-bit sensor data and their mean squared error (MSE) performances are evaluated through simulation studies. It is shown that selecting certain threshold values for quantizing the sensor outputs can lower the MSE. Genetic algorithms are used to find the optimal threshold values for the sensors. …
Intelligent Sensors For Integrated Health Management Systems, Christopher Oesch, Ajay Mahajan, Lucas Utterback, Haricharan Padmanaban, Sanjeevi Chitikeshi, Fernando Figueroa
Intelligent Sensors For Integrated Health Management Systems, Christopher Oesch, Ajay Mahajan, Lucas Utterback, Haricharan Padmanaban, Sanjeevi Chitikeshi, Fernando Figueroa
Dr. Ajay Mahajan
This paper describes work being conducted on the development of intelligent sensors with learning capabilities as part of an integrated systems approach. The integrated systems approach treats the sensor as a complete system with its own sensing hardware (the traditional sensor), A/D converter, processing and storage capabilities, software drivers, self-assessment algorithms, communication protocols and evolutionary methodologies that allow the system to learn its own behavior. The immediate application is the monitoring of rocket test stands, but the technology should be generally applicable to the Integrated Systems Health Monitoring (ISHM) vision. This paper outlines progress made in the development of intelligent …
Application Of Intelligent Sensors In The Integrated Systems Health Monitoring Of A Rocket Test Stand, Ajay Mahajan, Sanjeevi Chitikeshi, Lucas Utterback, Pavan Bandhil, Fernando Figueroa
Application Of Intelligent Sensors In The Integrated Systems Health Monitoring Of A Rocket Test Stand, Ajay Mahajan, Sanjeevi Chitikeshi, Lucas Utterback, Pavan Bandhil, Fernando Figueroa
Dr. Ajay Mahajan
This paper describes the application of intelligent sensors in the Integrated Systems Health Monitoring (ISHM) as applied to a rocket test stand. The development of intelligent sensors is attempted as an integrated system approach, i.e. one treats the sensors as a complete system with its own physical transducer, A/D converters, processing and storage capabilities, software drivers, self-assessment algorithms, communication protocols and evolutionary methodologies that allow them to get better with time. Under a project being undertaken at the NASA Stennis Space Center, an integrated framework is being developed for the intelligent monitoring of smart elements associated with the rocket tests …
Apparatus And Method Of Fabricating Directional Fiber Optic Taps, Sensors And Other Devices With Variable Angle Output, Susan D. Allen, Changhun Lee
Apparatus And Method Of Fabricating Directional Fiber Optic Taps, Sensors And Other Devices With Variable Angle Output, Susan D. Allen, Changhun Lee
Susan D. Allen
An apparatus and method for fabricating directional fiber optic taps having a variety of output angles. The taps can be used to monitor losses due to misalignment of the fiber or losses due to bending and straining of the fiber. The apparatus and method can also be used to fabricate taps which filter out higher order modes in a fiber. The apparatus and method can also be used to produce taps which can be used in a position or refractive index measuring system.
Characterization Of Conducting-Polymer-Based Bimorph Vibration Sensors, Weihua Li, Geoffrey M. Spinks, Lianbin Zhao, Yanzhe Wu, Dezhi Zhou, G G. Wallace
Characterization Of Conducting-Polymer-Based Bimorph Vibration Sensors, Weihua Li, Geoffrey M. Spinks, Lianbin Zhao, Yanzhe Wu, Dezhi Zhou, G G. Wallace
Professor Weihua Li
This paper presents theoretical and experimental investigation of mechanical-electrical properties of conducting polymers based bimorph sensors. A material parameter, hCP , is proposed to represent linear relationship between induction charge and the applied external deformation. Based on this assumption, a constitutive equation for bimorph sensors under steady-state external loadings are constructed and then solved. Mechanical-electrical properties of bimorph sensors are experimentally studied using both vibration-amplitude sweep mode and frequency sweep mode. The material parameter hCP , is identified by comparing theoretical analysis and experimental results. The applications of conducting polymers based bimorph sensors in smart structures are also discussed.
Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace
Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace
Gursel Alici
The characterization of the dynamic response (including transfer function identification) of trilayer polypyrrole (PPy) type conducting polymer sensors is presented. The sensor was built like a cantilever beam with the free end stimulated through a mechanical lever system, which provided displacement inputs. The voltage generated and current passing between the two outer PPy layers as a result of the input was measured to model the output/input behavior of the sensors based on their experimental current/displacement and voltage/displacement frequency responses. We specifically targeted the low-frequency behavior of the sensor as it is a relatively slowsystem. Experimental transfer function models were generated …
Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace
Response Characterization Of Electroactive Polymers As Mechanical Sensors, G. Alici, Geoffrey M. Spinks, J. D. Madden, Y. Wu, G G. Wallace
Gordon Wallace
The characterization of the dynamic response (including transfer function identification) of trilayer polypyrrole (PPy) type conducting polymer sensors is presented. The sensor was built like a cantilever beam with the free end stimulated through a mechanical lever system, which provided displacement inputs. The voltage generated and current passing between the two outer PPy layers as a result of the input was measured to model the output/input behavior of the sensors based on their experimental current/displacement and voltage/displacement frequency responses. We specifically targeted the low-frequency behavior of the sensor as it is a relatively slowsystem. Experimental transfer function models were generated …
Application Of A Bayesian Inference Method To Reconstruct Short-Range Atmospheric Dispersion Events, Inanc Senocak
Application Of A Bayesian Inference Method To Reconstruct Short-Range Atmospheric Dispersion Events, Inanc Senocak
Inanc Senocak
In the event of an accidental or intentional release of chemical or biological (CB) agents into the atmosphere, first responders and decision makers need to rapidly locate and characterize the source of dispersion events using limited information from sensor networks. In this study the stochastic event reconstruction tool (SERT) is applied to a subset of the Fusing Sensor Information from Observing Networks (FUSION) Field Trial 2007 (FFT 07) database. The inference in SERT is based on Bayesian inference with Markov chain Monte Carlo (MCMC) sampling. SERT adopts a probability model that takes into account both positive and zero-reading sensors. In …
Ultra-Thin-Film Aln Contour-Mode Resonators For Sensing Applications, Matteo Rinaldi, Chiara Zuniga, Gianluca Piazza
Ultra-Thin-Film Aln Contour-Mode Resonators For Sensing Applications, Matteo Rinaldi, Chiara Zuniga, Gianluca Piazza
Matteo Rinaldi
This paper reports on the design and experimental verification of a new class of ultra-thin-film (250 nm) aluminum nitride (AlN) microelectromechanical system (MEMS) contour mode resonators (CMRs) suitable for the fabrication of ultra-sensitive gravimetric sensors. The device thickness was opportunely scaled in order to increase the mass sensitivity, while keeping a constant frequency of operation. In this first demonstration the resonance frequency of the device was set to 178 MHz and a mass sensitivity as high as 38.96 KHz⋅μm2/fg was attained. This device demonstrates the unique capability of the CMR-S technology to decouple resonance frequency from mass sensitivity.
Dna-Decorated Carbon Nanotubes As Sensitive Layer For Aln Contour-Mode Resonant-Mems Gravimetric Sensor, Chiara Zuniga, Matteo Rinaldi, Samuel M. Khamis, Timothy S. Jones, A T. Johnson, Gianluca Piazza
Dna-Decorated Carbon Nanotubes As Sensitive Layer For Aln Contour-Mode Resonant-Mems Gravimetric Sensor, Chiara Zuniga, Matteo Rinaldi, Samuel M. Khamis, Timothy S. Jones, A T. Johnson, Gianluca Piazza
Matteo Rinaldi
In this work a nano-enabled gravimetric chemical sensor prototype based on single-stranded DNA (ss-DNA) decorated single-walled carbon nanotubes (SWNT) as nano-functionalization layer for Aluminun Nitride (AIN) contour-mode resonant-MEMS gravimetric sensors has been demonstrated. Two resonators fabricated on the same silicon chip and operating at different resonance frequencies, 287 and 450 MHz, were functionalized with this novel bio-coating layer to experimentally prove the capability of two distinct single strands of DNA bound to SWNT to enhance differently the adsorption of volatile organic compounds such as dinitroluene (DNT, simulant for explosive vapor) and dymethyl-methylphosphonate (DMMP, a simulant for nerve agent sarin). The …
Nanoenabled Microelectromechanical Sensor For Volatile Organic Chemical Detection, Chiara Zuniga, Matteo Rinaldi, Samuel M. Khamis, A. T. Johnson, Gianluca Piazza
Nanoenabled Microelectromechanical Sensor For Volatile Organic Chemical Detection, Chiara Zuniga, Matteo Rinaldi, Samuel M. Khamis, A. T. Johnson, Gianluca Piazza
Matteo Rinaldi
A nanoenabled gravimetric chemical sensor prototype based on the large scale integration of single-stranded DNA (ss-DNA) decorated single-walled carbon nanotubes (SWNTs) as nanofunctionalization layer for aluminum nitride contour-mode resonant microelectromechanical (MEM) gravimetric sensors has been demonstrated. The capability of two distinct single strands of DNA bound to SWNTs to enhance differently the adsorption of volatile organic compounds such as dinitroluene (simulant for explosive vapor) and dymethyl-methylphosphonate (simulant for nerve agent sarin) has been verified experimentally. Different levels of sensitivity (17.3 and 28 KHz µm^2/fg) due to separate frequencies of operation (287 and 450 MHz) on the same die have also …
5-10 Ghz Aln Contour-Mode Nanoelectromechanical Resonators, Matteo Rinaldi, Chiara Zuniga, Gianluca Piazza
5-10 Ghz Aln Contour-Mode Nanoelectromechanical Resonators, Matteo Rinaldi, Chiara Zuniga, Gianluca Piazza
Matteo Rinaldi
This paper reports on the design and experimental verification of Super High Frequency (SHF) laterally vibrating NanoElctroMechanical (NEMS) resonators. For the first time, AlN piezoelectric nanoresonators with multiple frequencies of operation ranging between 5 and 10 GHz have been fabricated on the same chip and attained the highest f-Q product (4.6E12 Hz) ever reported in AlN contour-mode devices. These piezoelectric NEMS resonators are the first of their class to demonstrate on-chip sensing and actuation of nanostructures without the need of cumbersome or power consuming excitation and readout systems. Effective piezoelectric activity has been demonstrated in thin AlN films having vertical …
Measurements Of Oh Mole Fraction And Temperature Up To 20 Khz By Using A Diode-Laser-Based Uv Absorption Sensor, Terrence Meyer, Sukesh Roy, Thomas Anderson, Joseph Miller, Vlswanath Katta, Robert Lucht, James Gord
Measurements Of Oh Mole Fraction And Temperature Up To 20 Khz By Using A Diode-Laser-Based Uv Absorption Sensor, Terrence Meyer, Sukesh Roy, Thomas Anderson, Joseph Miller, Vlswanath Katta, Robert Lucht, James Gord
Terrence R Meyer
Diode-laser-based sum-frequency generation of ultraviolet (UV) radiation at 313.5 nm was utilized for high-speed absorption measurements of OH mole fraction and temperature at rates up to 20 kHz. Sensor performance was characterized over a wide range of operating conditions in a 25.4 mm path-length, steady, C2H4-air diffusion flame through comparisons with coherent anti-Stokes Raman spectroscopy (CARS), planar laser-induced fluorescence (PLIF), and a two-dimensional numerical simulation with detailed chemical kinetics. Experimental uncertainties of 5% and 11% were achieved for measured temperatures and OH mole fractions, respectively, with standard deviations of <3% at 20 kHz and an OH detection limit of <1 part per million in a l m path length. After validation in a steady flame, high-speed diode-laser-based measurements of OH mole fraction and temperature were demonstrated for the first time in the unsteady exhaust of a liquid-fueled, swirl-stabilized combustor. Typical agreement of 5% was achieved with CARS temperature measurements at various fuel/air ratios, and sensor precision was sufficient to capture oscillations of temperature and OH mole fraction for potential use with multiparameter control strategies in combustors of practical interest.