Structured light-field focusing for flowfield diagnostics

A novel structured light-field focusing system is developed for flowfield measurements and visualization. The imaging technique provides true planar, two-dimensional, refractive measurements of flow structures. The innovative method is based on the light-field principle and multiple light sources to structure the two-dimensional planar focused imaging. The system is further unique in that it provides velocity fields from particles at extreme sampling rates (\u3e15 kHz) driven by the forward scatter relative to traditional particle image velocimetry (PIV) systems. The arrangement and characteristics of the system are presented. The method has also been used to visualize an under-expanded free jet and impinging jet. The technique is demonstrated on various flows including spray imaging and velocimetry at high acquisition rates to characterize the performance of the diagnostic system. Additionally, the limits of the system have been demonstrated as a method for micro-scale visualizations and dense medium imaging. The study developed a formulation for using the optical diagnostic technique. The optical system parameters can be tailored to drive a shallow depth of field. Detail optimization of the diagnostic technique to achieve shallow range depth of field at a high signal to noise ratios is discussed. Finally, design considerations are proposed which will be pertinent in future, large-scale experiments

Fast Dynamics and Stabilization of Proteins: Binary Glasses of Trehalose and Glycerol

We present elastic and inelastic incoherent neutron scattering data from a series of trehalose glasses diluted with glycerol. A strong correlation with recently published protein stability data in the same series of glasses illustrates that the dynamics at Q ≥ 0.71 Å(−1) and ω > 200 MHz are important to stabilization of horseradish peroxidase and yeast alcohol dehydrogenase in these glasses. To the best of our knowledge, this is the first direct evidence that enzyme stability in a room temperature glass depends upon suppressing these short-length scale, high-frequency dynamics within the glass. We briefly discuss the coupling of protein motions to the local dynamics of the glass. Also, we show that T(g) alone is not a good indicator for the protein stability in this series of glasses; the glass that confers the maximum room-temperature stability does not have the highest T(g)