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Your search keyword '"Hutchins, David A."' showing total 34 results
Start Over Author "Hutchins, David A." Publication Type Conference Materials
34 results on '"Hutchins, David A."'

4. The biogeochemical balance that controls oceanic nickel cycling in the modern and past oceans

Author

John, Seth, primary, Kelly, Rachel, additional, Bian, Xiaopeng, additional, Yang, Shun-Chung, additional, Fu, Feixue, additional, Smith, Magdalene, additional, Lanning, Nathan, additional, Liang, Hengdi, additional, Pasquier, Benoit, additional, Seelen, Emily, additional, Holzer, Mark, additional, Conway, Tim, additional, Fitzsimmons, Jessica, additional, and Hutchins, David, additional

Published
2022
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8. Air-coupled ultrasonic inspection of composite materials for aerospace applications.

Author

Rizwan, Muhammad Khalid, Laureti, Stefano, Burrascano, Pietro, Petrucci, Roberto, Torre, Luigi, Hutchins, David, and Ricci, Marco

Subjects
COMPOSITE materials, SIGNAL-to-noise ratio, BANDWIDTHS, CARBON fiber-reinforced plastics, MEASUREMENT
Abstract

Inspection of carbon fiber reinforced polymers (CFRP) using air-coupled (AC) ultrasonic measurements is challenging due to the large acoustic mismatch of the material to air. The acquired signal-to-noise ratio (SNR) of measurement process is not enough to obtain the required sensitivity of inspection. Pulse compression (PuC) is applied together with other signal processing tools to overcome the problem of low SNR of the measurement process. In this work, a linear chirp signal is used to implement PuC for the AC ultrasonic inspection of a CFRP sample for the delamination identifications. It is shown that the defects are characterized with a good lateral and spatial resolution in C-Scan images obtained by exploiting both the time amplitude and phase parameters of the retrieved impulse response. The required sensitivity of inspection is achieved by optimizing time duration and bandwidth of the applied chirp signal in accordance with the measurement setup. [ABSTRACT FROM AUTHOR]

Published
2019
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9. Pulse compression based phased array ultrasonic inspection: Optimization of the system and the code selection.

Author

Rizwan, Muhammad Khalid, Laureti, Stefano, Burrascano, Pietro, Giovannetti, Matteo, Cellai, Andrea, Watson, Richard, Hutchins, David, and Ricci, Marco

Subjects
PULSE compression (Signal processing), TRANSDUCERS, SIGNAL processing, SIGNAL-to-noise ratio, ALUMINUM
Abstract

Pulse compression applied to the signal processing in NDT inspections has shown significant improvement in the signal-to-noise-ratio of the measurements. The sensitivity of ultrasonic phased array measurements is enhanced when combined with pulse compression procedures. In this work, pulse compression has been implemented to linear array transducers, while using frequency modulated, chirp excitation signals. A system of signal generation and acquisition has specifically been designed for the realization of the proposed phased array inspection system based on pulse compression. A reference aluminum sample with known flat bottom holes was inspected with the proposed system. The spatial and lateral resolutions obtained from Sector B-scan images demonstrate the quality of defect detection and characterization. [ABSTRACT FROM AUTHOR]

Published
2019
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11. Rigging the oceans of Disney's "Moana"

Author

Garcia, Jonathan, primary, Drakeley, Sara, additional, Palmer, Sean, additional, Ramos, Erin, additional, Hutchins, David, additional, Habel, Ralf, additional, and Stomakhin, Alexey, additional

Published
2016
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16. Big Hero 6

Author

Hutchins, David, primary, Riley, Olun, additional, Erickson, Jesse, additional, Stomakhin, Alexey, additional, Habel, Ralf, additional, and Kaschalk, Michael, additional

Published
2015
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17. Further Capacitive Imaging Experiments Using Modified Probes.

Author

Xiaokang Yin, Zhen Li, An Yan, Wei Li, Guoming Chen, and Hutchins, David. A.

Subjects
IMAGING systems, NONDESTRUCTIVE testing, STRUCTURAL engineering, CARBON fibers, CRYSTAL defects
Abstract

In recent years, capacitive imaging (CI) is growing in popularity within the NDE communities, as it has the potential to test materials and structures for defects that are not easily tested by other techniques. In previous work, The CI technique has been successfully used on a various types of materials, including concrete, glass/carbon fibre composite, steel, etc. In such CI experiments, the probes are normally with symmetric or concentric electrodes etched onto PCBs. In addition to these conventional coplanar PCB probes, modified geometries can be made and they can lead to different applications. A brief overview of these modified probes, including high resolution surface imaging probe, combined CI /eddy current probe, and CI probe using an oscilloscope probe as the sensing electrode, is presented in this work. The potential applications brought by these probes are also discussed. [ABSTRACT FROM AUTHOR]

Published
2016
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23. Negative Measurement Sensitivity Values of Planar Capacitive Imaging Probes.

Author

Xiaokang Yin, Guoming Chen, Wei Li, and Hutchins, David

Subjects
PHYSICAL measurements, CAPACITIVE sensors, PARAMETER estimation, ELECTRODES, SENSITIVITY analysis
Abstract

The measurement sensitivity distribution of planar capacitive imaging (CI) probes describes how effectively each region in the sensing area is contributing to the measured charge signal on the sensing electrode. It can be used to determine the imaging ability of a CI probe. It is found in previous work that, there are regions in the sensing area where the change of the charge output and the change of targeting physical parameter are of opposite trends. This opposite correlation implies that the measurement sensitivity values in such regions are negative. In this work, the cause of negative sensitivity is discussed. Experiments are also designed and performed so as to verify the existence of negative sensitivity and study the factors that may affect the negative sensitivity distributions. [ABSTRACT FROM AUTHOR]

Published
2014
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26. Prep and landing

Author

Coony, Ian J., primary, Hutchins, David, additional, Lee, Kevin, additional, Harris, Mike, additional, Molinder, Tim, additional, and Suong, Kee, additional

Published
2010
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29. The SAMTEX Experiment: Overview and Preliminary Results

Author

G. Jones, Alan, primary, L. Evans, Rob, additional, R. Muller, Mark, additional, P. Hamilton, Mark, additional, P. Miensopust, Marion, additional, Garcia, Xavier, additional, Cole, Patrick, additional, Ngwisanyi, Tiyapo, additional, Hutchins, David, additional, Stoffel Fourie, C.J., additional, Evans, Shane, additional, Jelsma, Hielke, additional, Aravanis, Theo, additional, Pettit, Wayne, additional, Webb, Sue, additional, Wasborg, Jan, additional, and The SAMTEX Team, and, additional

Published
2009
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30. Magnetotelluric Study in Northeastern Botswana

Author

P. Miensopust, Marion, primary, G. Jones, Alan, additional, R. Muller, Mark, additional, P. Hamilton, Mark, additional, Garcia, Xavier, additional, L. Evans, Rob, additional, Cole, Patrick, additional, Ngwisanyi, Tiyapo, additional, Hutchins, David, additional, Fourie, C.J.S., additional, Jelsma, Heilke, additional, Aravanis, Theo, additional, Pettit, Wayne, additional, Webb, Sue, additional, Wasborg, Jan, additional, and SAMTEX Team, The, additional

Published
2009
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