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Polarization switching-induced shielding or anti-shielding of an electrically permeable crack in a mono-domain ferroelectric material with the original polarization direction perpendicular to the crack is simulated by a phase field model based on the time-dependent Ginzburg-Landau equation. The domain wall energy and the long-range mechanical and electrical interactions between polarizations are taken into account. The phase field simulations exhibit a wing-shape- switched zone backwards the crack tip.

A stiff skin forms on surface areas of a flat polydimethylsiloxane (PDMS) upon exposure to focused ion beam (FIB) leading to ordered surface wrinkles. By controlling the FIB fluence and area of exposure of the PDMS, one can create a variety of patterns in the wavelengths in the micrometer to submicrometer range, from simple one-dimensional wrinkles to peculiar and complex hierarchical nested wrinkles. Examination of the chemical composition of the exposed PDMS reveals that the stiff skin resembles amorphous silica. Moreover, upon formation, the stiff skin tends to expand in the direction perpendicular to the direction of ion beam irradiation. The consequent mismatch strain between the stiff skin and the PDMS substrate buckles the skin, forming the wrinkle patterns. The induced strains in the stiff skin are estimated by measuring the surface length in the buckled state. Estimates of the thickness and stiffness of the stiffened surface layer are estimated by using the theory for buckled films on compliant substrates. The method provides an effective and inexpensive technique to create wrinkled hard skin patterns on surfaces of polymers for various applications. Click here for access to the full article. See also the press release: Applied scientists create wrinkled 'skin' on polymers

Sandia National Laboratories, California has established the Engineering Sciences Summer Institute (ESSI) program, in which applied mechanics, structural analysis and mechanical engineering graduate students are invited to spend a summer at SNL/CA performing research that would jointly benefit the students and Sandia. The program is nine years old and a description of the program is attached. Because of the funding base for this program, we can only consider students having U.S.

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Deadline for submitting an abstract: 5 March 2007.

Responding to the wishes of members, the ASME Congress will change to a new format, starting this year. Sessions will not be allocated to Divisions, but will be allocated to symposiums after abstracts are reviewed. Thus, your action item is to submit an abstract to a symposium. Here are terms as used in the 2007 Congress:

Session. Technical sessions will be scheduled for four days, Monday-Thursday. Each session will last 90 minutes, and consists of 4-6 talks. There will be 23 parallell sessions at a given time, 5 time slots for sessions per day, and a total of 23x5x4 = 460 sessions for the entire congress.

Suppose if somebody asked you the following question, and more importantly, wanted the answer to an accuracy of 100-digits:

• Problem A: A particle at the center of a 10 x 1 rectangle undergoes Brownian motion (i.e., two-dimensional random walk with infinitesimal step lengths) until it hits the boundary. What is the probability that it hits at one of the ends rather than at one of the sides?

Or, this question (again, demanding the answer to an accuracy of 100-digits):