You are here
TREND Fair 2011
August 3, 2011
On this page... TREND 2011 Presentations
- Multiscale Oscillator Interaction in Large Networks of Networks, Dustin Anderson and Ari Tenzer
- Electromagnetic Wave Chaos in 3D Cavities, Sabrina Atienza
- Cesium Evaporation Rate on Tungsten Photocathodes, Ameerah Jabr-Hamdan
- Two-Dimensional Spatiotemporal Communication, Kristi Engel
- Charge Buildup in Sandstorms, Zack Lasner
- Recording Sounds in Superfluid
He at 2.17 Kelvin and Below, Patrick M. McDonough
- Particle Image Velocimetry of Optically Stretched Cells, Samuel Engel
- Using Morphology to Characterization LAT Protein Patterns, Brian Slusher
- Estimation Methods in a Magnetic Marking System for Cancer Surgery, Maia Werbos
Winners of TREND Fair 2011
Best Overall Project: Dustin Anderson and Ari Tenzer for their project titled "Multiscale Oscillator Interactions in Large Networks of Networks."
The TREND runner-up for Best Overall Project went to Zack Lasner for his project titled "Charge Buildup in Sandstorms."
Dustin Anderson, Carleton College
Ari Tenzer, Washington University in St. Louis
Advisors: Professor Edward Ott, Professor Thomas Antonsen, Assistant Professor Michelle Girvan, and Gilad Barlev
Networks of coupled oscillators occur commonly in physics, biology, and neuroscience. The Kuramoto model, which formalizes and explains the phenomenon of synchronization in such networks, is a useful tool for understanding their dynamics. We explore an extension of the Kuramoto model in which each oscillator acts as part of a community. Oscillators within a community synchronize and act as a coherent unit, while oscillators in different communities have a repulsive effect on one another. We characterize the equilibrium configurations of this kind of oscillator network and determine which configurations are stable. We also investigate how these equilibria change when the oscillator groups are allowed to have different natural frequency distributions.
Sabrina Atienza, University of California - Berkeley
Advisor: Dr. John Rodgers
We investigate the applicability of the Random Coupling Model (RCM) to electromagnetic (EM) fields within general complex cavities. In this experiment, we measure the statistics of the scattering and impedance matrices of a two-port, three-dimensional cavity, not known to produce wave chaos but of sufficient complexity to randomize steady-state EM field distributions. Rotation of an aluminum perturber generates unique realizations of EM field distributions. We demonstrate that RCM provides a valid statistical description of our sufficiently complex cavity given time reversal symmetry (TRS) or TRS broken, thereby validating the utility of RCM in predicting semclassical wave-chaotic structures.
Ameerah Jabr-Hamdan, Clarkson University
Advisors: Professor Patrick O'Shea, Dr. Eric J. Montgomery, Blake Riddick, and Peter Zhigang Pan
Photocathodes are necessary for high peak power free electron lasers and other accelerator applications. The optimal photocathode has a long lifetime and high quantum efficiency. Knowledge of the evaporation rate of cesium on tungsten is important for calculating the lifetime of tungsten dispenser photocathodes and minimizing cesium contamination of any system in which the photocathodes are used. Maintaining a cesium coating increases the lifetime of the photocathode, while allowing a lower work function than that of the metals the cesium rests on. In this work, a submonolayer coating of cesium was evaporated from a tungsten dispenser photocathode, after a shutter was built to shield different elements in the vacuum chamber as needed.
Advisors: Professor Rajarshi Roy, Associate Professor Thomas Murphy, and Aaron Hagerstrom
We explore the idea of two-dimensional spatiotemporal communication using a pair of nonlinear electro-optic feedback loops based on liquid crystal spatial light modulations (SLM) and digital cameras, which operate at 1550 nm. The device exploits the synchronization of spatiotemporal chaos to encode and decode messages in the form of two-dimensional images. We linearly couple an experimental ring containing a SLM to a numerical model, allowing them to achieve synchronization. By utilizing this synchrony, the model is able to recover data hidden in the chaotic behavior of the optical ring. Mathematical modeling of spatiotemporal array synchronization was also performed using MATLAB. In both systems, the error effects of different topology and parameter mismatch in the encoding-decoding process were evaluated.
Zack Lasner, Pomona College
Advisors: Professor Daniel Lathrop, Donald Martin, Dr. Daniel Zimmerman, Hansen Nordsiek, and David Meichle
We experimentally investigate triboelectric charging, a poorly understood process by which insulators of identical material become statically charged upon contact. Dry sand is shaken in a cell with metal plates on two opposite walls, with voltage spikes across the cell observed when a charged particle collides with the conducting walls and discharges. The effect of externally applied electric fields is quantitatively investigated to elucidate observations that external electric fields significantly contribute to the charging process in natural sandstorms.
Patrick M. McDonough, University of Maryland
Advisors: Professor Daniel Lathrop, Enrico Fonda, and David Meichle
4He starts the transition to a superfluid at 2.17 Kelvin. Quantized vorticies are an experimentally verified feature which explains some of the exotic properties of superfluid. An observed process of these vorticies is called reconnection which occurs when two vorticies cross. In this manner, two horizontally moving vorticies will come in contact and form an "X." Then the "X" will snap into two vorticies moving vertically away from each other similar to rubber bands snapping apart from each other. I have acoustically recorded this process using a Microelectromechanical systems microphone. These recordings are being analyzed to isolate the sound of one reconnection.
Samuel Engel, Columbia University
Advisors: Associate Professor Wolfgang Losert, Eleanor Ory, and Matthew Kretschmer
One approach to better understanding cancer metastasis is to study the dynamics of a cancer cell. An optical stretcher aims two lasers at opposite ends of a cell, causing the cell to expand along the axis of the beams. Observing a cell's stretch and recoil gives information about that cell. Previous studies of optical stretcher data have focused primarily on cell boundaries, but internal shifts could yield equally valuable insights. Particle Image Velocimetry (PIV) can be used to produce velocity data about a moving cell's interior as well as its edge. This work aims to analyze chemically-treated and optically-stretched cancer cells using PIV.
Brian Slusher, The Ohio State University
Advisors: Associate Professor Wolfgang Losert and Joshua Parker
With development of the photoactivated localization microscopy (PALM), it is now possible to image the spatial distribution of proteins in vivo with approximately 10 nm reolution. From these images, one can generate point distributions of the proteins. The proteins studied as examples here, LAT, are essential for function and differentiation of T-cells and are of great interest in immunology. A standard approach to characterizing the protein localization patterns would be seco
Maia Werbos, University of Maryland
Advisor: Professor Wesley Lawson
A magnetic marking system for use in cancer surgery is being tested. In this system, a small permanent magnet is inserted into the affected region before surgery; during surgery, a device using an array of magnetic sensors detects the presence of the magnet and guides the surgeon in locating it. This method can make surgery safer and quicker, but the precision and usefulness of the device need to be improved. In this project, mathematical methods for estimating different parameters that will assist the surgeon, such as distance to the magnet and angle of incidence to the magnet, are proposed and tested in simulations of the magnet's generated field.