Laura E. Schmidt James Franck Institute Gordon Center for Integrative Science 929 E 57th St., Room E208 Chicago, IL 60637 office tel:(773)702-0946

current research previous research links CV (pdf)

(photos by Dan Dry)

I'm a graduate student in the Department of Physics at the University of Chicago. I work with Prof. Wendy Zhang and study a variety of fluid dynamics problems using analytical and numerical techniques.

CURRENT RESEARCH:

A remarkable implosion singularity exhibits distinct vibrations when its natural symmetry is perturbed. Our theoretical analysis predicts that a collapsing circular hole in water should have a precise memory of any distortion to its shape. The memory is manifested in vibrations of the shape as the hole closes. This ideal implosion is relevant to the singularity produced when a bubble breaks up after being released from an underwater nozzle (imaged here). Our collaboration with experimentalists Sid Nagel and Nathan Keim has shown that vibrations induced in an experiment by using a slot-shaped nozzle are consistent with the ideal implosion singularity. As the breakup is approached, the cross-sectional shape of the thin column of air vibrates and inextricably alters the final stages of the singularity, leading to unusual shapes and topology changes. A more general summary can be found here. (APS-DFD 2007 talk and abstract).	Thin, ribbon-like neck of air (black) breaks apart in water (white). This exotic breakup occurs when a burst of air is forced through a slot-shaped nozzle. Keim et al, PRL 97. 144503 (2006)
Thin tendrils of liquid have been observed in thermal convection experiments with two miscible liquid layers (as shown in the image). Despite their tenuous appearance, the tendrils remain fixed and persist for long times. Because mixing between the layers occurs mainly by transport through the tendrils, we derive a scaling argument for the size of and volume flux through the tendrils. A more detailed calculation shows that though the entrainment dynamics is coupled to the large-scale flow, this coupling is very weak, making the tendrils insensitive to fluctuations in the large-scale flow. PRL article , an explanation for non-experts, the U. of Chicago Chronicle article. and Chicago Sun Times article .	Davaille et al, EPSL 203, 621 (2002)
How do cells generate the forces to divide into two? Dictyostelium cells studied in Douglas Robinson's Lab undergo cytokinesis via a robust set of shape changes. A furrow forms and thins into a slender, cylindrical bridge whichc eventually pinches off. Using the known geometry, we are trying to understand cytokinesis from simple physics. ( APS-DFD 2007 talk).	Zhang & Robinson, PNAS 102, 7186 (2005)

PREVIOUS RESEARCH

Stunning patterns are left behind when a drop of a colloidal solution dries. A drop starting with a uniform distribution of particles leaves a very uneven stain. We now understand that the colloid collects at the edge of the drop because the edge is pinned. When liquid evaporates from the drop, an outward flow must occur to maintain the pinned boundary, transporting the particles with it ( more info). With Todd Dupont I simulated the evolution of the drop and the accumulation of particles in the ring at the edge of the drop.	Deegan et al, PRE 62, 756 (2000). Deegan U. Chicago thesis (1998)
Selective withdrawal with a polymer solution. Below is a series of photographs showing the interface transition from "hump" to spout in the selective withdrawal system (upper fluid heavy mineral oil, lower fluid 10 ppm (by mass) PEO in water). Here is my short paper (pdf) on the subject: Polymeric effects on the transition in a selective withdrawal system.
Simple climate modeling investigating the energy balance of the earth. "Development of an Elementary Climate Model: Two-Layer Cellular Case" LLE Review, Vol. 94, Jan-Mar 2003, pgs. 128-138.

LINKS

Computations in Science Seminar series
U. Chicago MRSEC