Brown University - Joint Materials/Solid Mechanics Seminar Series
Department of Mechanical and Aerospace Engineering, Rutgers - The State University of New Jersey, Piscataway, NJ 08854 cuitino@jove.rutgers.edu | |
Abstract: Cohesive particles tend to form structures with relatively large voids during die filling. Upon application of a relatively small compaction load, the large voids disappear by a densification mechanism involving non-affine particle motion or by particle rearrangement. In this talk, experimental observations, theoretical predictions and numerical simulations will show that the rearrangement process does not yield to a spatially uniform density profile. Instead, two zones with different densities separated by a sharp density gradient band, the rearrangement front, are observed. This process proceeds as a system exhibiting phase transformation. This compaction front is nucleated at the moving (top) punch and moves away as the compaction proceeds until the front reaches the stationary (bottom) punch, ending the rearrangement process. Also, numerical studies will be presented to analyze the evolution of the rearrangement process and the subsequent consolidation where particle deformation dominates. For this regime a Granular Quasi-Continuum formulation is proposed to trace particle motion within a constrained displacement field. The predictions of the theory compare well with the experimental observations.
Stochastic Systems Seminar
Abstract: Debt is a useful means for economic development, but high debt levels involve risks if conditions become unfavorable. Stochastic control models of investment, consumption and debt are discussed in three different contexts: debt incurred nationally by borrowing from foreign sources, debt owed by businesses and consumer debt. The models considered are controlled Markov diffusion processes, and the method to analyze them is dynamic programming.
Interdepartmental Seminar Series On
Computational Molecular Biology
Abstract: In this talk, I will affirmatively answer the following question: Given a particular protein - a site specific-recombinase - and given the topology of the DNA before and after the protein action, can one determine the local orientation of the bound DNA? I answer this using biochemical analyses coupled with mathematical/topological arguments - primarily arguments known in mathematics as Dehn surgery. (No, no prior knowledge of recombinase or Dehn surgery needed).
PDE Seminar
Department of Mathematics Colloquium
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