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Theoretical Physics Colloquia

Friday, February 03, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II

Hamid Ramezani, graduate student Wesleyan Physics Department

ESC 216

Friday, February 10, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II

Prof. Reinhold Blumel, Physics Department Wesleyan Nano trap for neutral, polar molecules

ESC 216

Friday, February 17, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II

Prof. Fred Ellis, Professor Physics Department, Wesleyan"Tailoring Nonlinear Elements in Electronics"

ESC 216

Friday, February 24, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II

APS Practice Talks

ESC 216

Friday, March 02, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II, More than one dynamic crossover in protein hydration water

More than one dynamic crossover in protein hydration waterGiancarlo Franzese,Universitat de BarcelonaBulk water freezes at its homogeneous nucleation temperature ($\approx 235$~K), but protein hydration water avoids this crystallization because each water molecule binds to a protein. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules and compare the measurements of a hydrated globular protein with the results of a coarse-grained model that successfully reproduces the properties of hydration water. Using dielectric spectroscopy we measure the temperature dependence of the relaxation time of proton charge fluctuations. These fluctuations are associated with the dynamics of the HB network of water molecules adsorbed on the protein surface. Using Monte Carlo (MC) simulations and mean-field (MF) calculations, we study the dynamics and thermodynamics of the model. Both experimental and model analyses are consistent with the interesting possibility of two dynamic crossovers, (i) at $\approx 252$~K, and (ii) at $\approx 181$~K. Because the experiments agree with the model, we can relate the two crossovers to the presence at ambient pressure of two specific heat maxima. The first is caused by fluctuations in the HB formation, and the second, at a lower temperature, is due to the cooperative reordering of the HB network.

ESC 216

Friday, March 09, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II

YunSeong Nam '12

ESC 216

Friday, March 30, 2012

01:10 pm - 02:00 pm

PHYS-510-01 Theoretical Physics Seminar II

Prof. Francis Starr, Physics Department Wesleyan University

ESC 216

Friday, April 06, 2012