20150203 Colloquium Talk At Rhodes College

Two grad students (Sunethra Dayavansha and Nazanin Omidi) and I gave a colloquium talk at Rhodes College in Memphis (here's our crazy selfie).

After the talk, we stopped by an SPS meeting (of course free pizza, it's SPS!). Rhodes has an incredible SPS group. They've received outstanding chapter awards for at least the last 10 years running! Then we saw a very cool demo where they supercooled some beer (Corona to be exact) and then by tapping the beer on the lab benchtop, the freezing process was initiated. It was a fun trip.

20150122 Article published in UMB: Theoretical Study of Inertial Cavitation from Acoustic Radiation Force Impulse Imaging and Implications for the Mechanical Index

Charles C. Church, Cecille Labuda and Kathryn Nightingale. A Theoretical Study of Inertial Cavitation from Acoustic Radiation Force Impulse Imaging and Implications for the Mechanical Index. Ultrasound Med Biol; 41(2) 2015. http://dx.doi.org/10.1016/j.ultrasmedbio.2014.09.012

Abstract. The mechanical index (MI) attempts to quantify the likelihood that exposure to diagnostic ultrasound will produce an adverse biological effect by a non-thermal mechanism. The current formulation of the MI implicitly assumes that the acoustic field is generated using the short pulse durations appropriate to B-mode imaging. However, acoustic radiation force impulse (ARFI) imaging employs high-intensity pulses up to several hundred acoustic periods long. The effect of increased pulse durations on the thresholds for inertial cavitation was studied computationally in water, urine, blood, cardiac and skeletal muscle, brain, kidney, liver and skin. The results indicate that, although the effect of pulse duration on cavitation thresholds in the three liquids can be considerable, reducing them by, for example, 6%–24% at 1 MHz, the effect on tissue is minor. More importantly, the frequency dependence of the MI appears to be unnecessarily conservative; that is, the magnitude of the exponent on frequency could be increased to 0.75. Comparison of these theoretical results with experimental measurements suggests that some tissues do not contain the pre-existing, optimally sized bubbles assumed for the MI. This means that in these tissues, the MI is not necessarily a strong predictor of the probability of an adverse biological effect.

20150116 - 0118 APS Conference for Undergraduate Women in Physics at the University of Mississippi

Last year, I along with Luca Bombelli and Marco Cavaglia submitted a proposal to host the American Physics Society Conferences for Undergraduate Women in Physics (APSCUWiP). The Department of Physics at the University of Mississippi was selected as one of the eight host sites (University of Mississippi, North Carolina Research Triangle, Purdue University, Rutgers, University of California Santa Cruz, University of Michigan, University of Texas at Brownsville and Yale University ). The APSCUWiP took place this weekend, January 16 - 18 2015, and about 100 undergraduate students attended. Many of the UM Physics students were part of the local organizing committee.

You can view photo galleries of the conference here: Photo Galleries.