David Turnbull died peacefully at home last Saturday, April 28th, at age 92.
He was for many years Gordon McKay Professor of Applied Physics at Harvard University. His seminal work included theoretical and experimental studies of nucleation of crystals, the glass transition and the amorphous state, crystal growth, and atomic diffusion.
<>To describe the crack propagation in a fluid saturated solid I have idea to combine the Strong Discontinuity (XFEM) with the fluid, but at the micro-scale, which probably means to use (Navier-)Stokes equations or some modification of them. <>
Hi everyone,
We are looking for the practical solutions for building a thermal diode using nanocomposites. A thermal diode allows the heat flow from one end to the other, but it inhibits the flow in the opposite direction. There are some simulations and theoretical work in this regard. Does anyone know any experimental work related to this matter? Thanks.
Welcome to the May 2007 issue. This issue focuses on experimental nanomechanics of nanobuilding blocks. The extremely small dimensions of nanobuilding blocks (for instance, nanoparticles, nanotubes, and nanowires) have imposed great challenges to many existing instruments, methodologies, and even theories. In this issue, we will discuss – (1) experimental techniques and (2) size-effects.
Huang et al., PRL 98, 185501 (2007)
Watch movies at: http://netserver.aip.org/cgi-bin/epaps?ID=E-PRLTAO-98-002719
We report exceptional ductile behavior in individual double-walled and triple-walled carbon nanotubes at temperatures above 2000 C, with tensile elongation of 190% and diameter reduction of 90%, during in situ tensile-loading experiments conducted inside a high-resolution transmission electron microscope. Concurrent atomic-scale microstructure observations reveal that the superelongation is attributed to a high temperature creep deformation mechanism mediated by atom or vacancy diffusion, dislocation climb, and kink motion at high temperatures. The superelongation in double-walled and triple-walled carbon nanotubes, the creep deformation mechanism, and dislocation climb in carbon nanotubes are reported here for the first time.
With a shallow chemical etching the roughness with spatial frequency below a critical value grows while the roughness of higher frequency decays.
I'm saddened by the recent resignation of Marilee Jones, the dean of admissions at MIT. By all accounts she has been an excellent employee, but she lied about her degrees when she first applied for an entry-level job 28 years ago.
I do think that lying is wrong, and I can't blame the administration of MIT for taking actions. However, I'm uneasy about the general practice of employment.
Subject: NSF Proposal Writing Workshop ( August 22-23, 2007 - Alaska)
Sponsored by NSF, a Proposal Writing Workshop will be held on August 22-23, 2007, at University of Alaska-Fairbanks. The workshop mainly aims to provide future proposal submitters (in all disciplines funded by NSF) with knowledge and tools to write good proposals, proposal review experience, and it will enable interactions with NSF program directors and recent NSF awardees. The event is targeted at an EPSCoR state, Alaska. However, the workshop is open to participants from other states as space permits.
