Presentations

    Exclusively-visual analysis of classroom group interactions, at American Association of Physics Teachers Winter Conference (San Diego, CA), Sunday, January 4, 2015:
    Data that measures group learning are time-consuming to collect and analyze on a large scale. As an initial step towards scaling qualitative classroom observation, our team qualitatively coded classroom video using an established coding scheme with and without its audio. We find that inter-rater reliability is as high when using visual data only—without audio—as when using both visual and audio data to code. Also, inter-rater reliability is high even when comparing use of visual and audio data to visual-only data. We see a small bias that interactions are more often coded as group... Read more about Exclusively-visual analysis of classroom group interactions
    Plasmonic Cell Transfection using Micropyramid Arrays, at SPIE Photonics West, SPIE (San Francisco, CA), Sunday, February 8, 2015:
    We present a new cell transfection method that uses femtosecond laser-excited localized surface plasmons (LSPs) on a nanostructured micropyramid array. Our gold-layered micropyramids have nano-apertures at the apex to form high local electric field enhancements, or “hot spots.” These hot spots form microbubbles that temporarily perforate mammalian cell (HeLa S3) membranes and allow dye molecules and plasmid vectors to diffuse through the membrane openings. We introduce an emerald green fluorescent protein (EmGFP) reporter plasmid into the cells to determine the LSP-mediated transfection... Read more about Plasmonic Cell Transfection using Micropyramid Arrays
    Raman spectroscopy of infrared multiphoton excited molecules, at XIVth Int. Quantum Electronics Conf. (San Francisco, CA), Wednesday, January 1, 1986
    Anti-Stokes signals from various modes of isolated, infrared multiphoton excited SF6 and C2H4F2 molecules are measured as a function of pressure, infrared fluence and wavelength. This allows to verify whether intramolecular equilibrium of vibrational energy is established after infrared multiphoton excitation in isolated molecules.
    Light scattering from nonequilibrium liquid interfaces, at Tenth Symposium on Thermophysical Properties (Gaithersburg, MD), Wednesday, June 1, 1988
    The asymmetry of the two Brillouin peaks of light scattered from capillary waves on a water-nitrogen interface subject to a temperature gradient has been observed using a Fourier transform heterodyne technique. The local oscillator is frequency-shifted by a few kHz to separate the Stokes and anti-Stokes components. Although the sign and the order of magnitude of the effect agree with linear theory, the magnitude of the experimental asymmetry is about one half of the one predicted by linear fluctuating hydrodynamics.
    Fourier transform heterodyne spectroscopy of liquid interfaces, at Conference on Laser Materials and Laser Spectroscopy '88 (Shanghai, People's Republic of China), Friday, July 1, 1988
    By acousto-optically shifting the local oscillator in a heterodyne set-up, a spectral resolution of better than 150 mHz can be obtained. Applications of the technique to the study of interfacial phenomena are discussed.
    Laser melting of silicon: the first few picoseconds, at Annual Meeting of the Electrochemical Society (Chicago, IL), Saturday, October 1, 1988
    The use of a streak camera makes it possible to improve the study of the melting of silicon during picosecond laser annealing. Its time resolution of 1.8 ps enables us to confirm that the molten silicon is heated above the melting temperature. It also provides spatial information on the melting process.
    Multiplex CARS study of infrared-multiphoton-excited OCS, at Ninth International Conference on Laser Spectroscopy (Bretton Woods, NH), Thursday, June 1, 1989
    The vibrational energy distribution following the ?2 overtone excitation of OCS by a pulsed CO2 laser can be studied by coherent anti-Stokes Raman spectroscopy (CARS) of the ?1 mode. Since the anharmonicity of the pumped mode is small, and since the relaxation to other modes is slow, OCS allows one to study the interaction of an isolated harmonic mode with an intense laser field. Single-shot spectra are obtained by using a broadband dye laser and recording the CARS signal on a multichannel analyzer. The phase matching of the beams is done in a so-called folded boxcars arrangement. The... Read more about Multiplex CARS study of infrared-multiphoton-excited OCS

Pages