Graduate Seminar Series
Please check Seminar Announcements for location
Monday November 9, 2009 | 320 Randolph Hall: In order to improve the efficiency of fossil fuel power plant and reduce the emission, some in-line measurement techniques are developed in the Institute of Particle & Two-phase Flow Measurement, University of Shanghai for Science & Technology, Shanghai, China. These techniques includes wet steam measurement in LP steam turbine, in-line measurement of size, concentration and velocity of pulverized coal and concentration of SO2, NOx, dust of emission, in-line monitoring of flame with spectrum analysis, etc. The measurement principles about these methods and results will be briefly presented. Hosted by: Dr. Wing Ng |
Wednesday November 11, 2009 | 1870 Litton Reeves: Recent development of crack propagation analysis is rapidly advanced and its applications are being extended. Usually finite element method is utilized in the analysis. One of the most important tasks is mesh generation which requires a fully automated system with no failures. It is very difficult to meet all geometrical and mechanical requirements for surface mesh generation. This talk presents techniques developed to generate surface crack hexahedral mesh for S-version FEM and to control node generation for surface crack tetrahedral mesh without failures. Hosted by: Dr. Tomonari Furukawa |
Friday November 13, 2009 | 1870 Litton Reeves: Bat echolocation systems must balance the conflicting demands of detecting weak targets in noise and resolving closely spaced reflectors for complex acoustic environments. Bats demonstrate an impressive ability to discriminate targets with multiple reflectors, or glints, where the interglint intervals are much smaller than the integration time of the bat auditory system, and at times even closer together than the mainlobe width for the autocorrelation function of the bat's transmitted chirp signal. This suggests that the bats' auditory processing functions as a sonar receiver which goes beyond a simple matched filter. This talk will present the Variable Resolution and Detection Receiver (VRDR), a new active sonar receiver design which smoothly trades detection performance for resolution performance. The VRDR converges to a matched filter at the detection asymptote and an inverse filter at the resolution asymptote. Monte Carlo experiments indicate that for a broad set of dipole (two echo) targets the VRDR achieves better performance than the classic matched filter or the tunable deconvolution algorithm previously proposed by Senmoto and Childers (IEEE AES, 1972). [Work performed in collaboration with Prof. James A. Simmons of Brown University, and supported by US Office of Naval Research.] Hosted by: Dr. Rolf Mueller |
Wednesday November 20, 2009 | 1060 Torgersen at 9am: Hosted by: Dr. Corina Sandu |
Friday November 20, 2009 | 1870 Litton Reeves: Cell migration is an important physiological process that has been extensively studied by biologists for decades. However, the focus has always been on identifying the genes and proteins that regulate the process. Increasingly, there is growing appreciation that the mechanical and physical aspects of how cells migrate are important too. This is an area where mechanical engineers and physicists can contribute extensively. In this presentation, three examples of applying physical principles to various aspects of cell migration will be discussed. First, we study the mechanics of the lamellipodia, which are actin-rich sheet-like protrusions that cells develop to adhere to and exert traction on their substrates in order to migrate. We develop a mathematical model of the lamellipodia protrusions, and use this model to predict how the velocity of protrusion depends on the rigidity of the substrate. Second, we study the mechanics of blebs, which are blister-like protrusions of cell membranes driven by changes in intracellular pressure. We develop a quantitative model to study how a bleb develops when a portion of the cell membrane detaches from the underlying cortex. From the model, we calculate the minimum cytoplasmic pressure and minimum unsupported membrane length for a bleb to nucleate and grow. Third, we consider how cells move collectively as an epithelial sheet in a directed fashion. Using a model borrowed from statistical physics, we propose that differential adhesion regulates the coordinated migration of cells in the epithelium. Hosted by: Dr. Mark Paul |
Monday December 7, 2009 | 320 Randolph Hall: Advisor: Dr. Danesh Tafti |