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Full-Text Articles in Engineering
Characterizing Phantom Arteries With Multi-Channel Laser Ultrasonics And Photo-Acoustics, Jami L. Johnson, Kasper Van Wijk, Michelle Sabick
Characterizing Phantom Arteries With Multi-Channel Laser Ultrasonics And Photo-Acoustics, Jami L. Johnson, Kasper Van Wijk, Michelle Sabick
Mechanical and Biomedical Engineering Faculty Publications and Presentations
Multi-channel photo-acoustic and laser ultrasonic waves are used to sense the characteristics of proxies for healthy and diseased vessels. The acquisition system is non-contacting and non-invasive with a pulsed laser source and a laser vibrometer detector. As the wave signatures of our targets are typically low in amplitude, we exploit multi-channel acquisition and processing techniques. These are commonly used in seismology to improve the signal-to-noise ratio of data. We identify vessel proxies with a diameter on the order of 1 mm, at a depth of 18 mm. Variations in scattered and photo-acoustic signatures are related to differences in vessel wall …
Heavy Element Doping For Enhancing Thermoelectric Properties Of Nanostructured Zinc Oxide, Priyanka Jood, Rutvik J. Mehta, Yanliang Zhang, Theo Borca-Tasciuc, Shi Xue Dou, David J. Singh, Ganpati Ramanath
Heavy Element Doping For Enhancing Thermoelectric Properties Of Nanostructured Zinc Oxide, Priyanka Jood, Rutvik J. Mehta, Yanliang Zhang, Theo Borca-Tasciuc, Shi Xue Dou, David J. Singh, Ganpati Ramanath
Mechanical and Biomedical Engineering Faculty Publications and Presentations
ZnO is a high melting point, high charge carrier mobility semiconductor with potential as a thermoelectric material, but its high thermal conductivity κ is the limiting factor for increasing the thermoelectric figure of merit ZT. Here, we demonstrate that doping ZnO with heavy elements can significantly enhance ZT. Indium doping leads to ultralow κ 3 W m−1 K−1 and a high power factor α2σ 1.230 × 10−3 W m−1 K−2, yielding ZT1000K 0.45 that is 80% higher than non-nanostructured In–Zn–O alloys. Although Bi doping also yields a high Seebeck coefficient of …