Orientation effects on the specific resistance of copper grain boundaries are studied systematically with two different atomistic tight binding methods. A methodology is developed to model the specific resistance of grain boundaries in the ballistic limit using the Embedded Atom Model, tight binding methods and non-equilibrum Green's functions (NEGF). The methodology is validated against first principles calculations for thin films with a single coincident grain boundary, with 6.4% deviation in the specific resistance. A statistical ensemble of 600 large, random structures with grains is studied. For structures with three grains, it is found that the distribution of specific resistances is close to normal. Finally, a compact model for grain boundary specific resistance is constructed based on a neural network. * valencid@purdue.edu 1 arXiv:1701.04897v3 [cond-mat.mtrl-sci]

The Faraday forcing method in levitated liquid droplets has recently been introduced as a method for measuring surface tension using resonance. By subjecting an electrostatically levitated liquid metal droplet to a continuous, oscillatory, electric field, at a frequency nearing that of the droplet’s first principal mode of oscillation (known as mode 2), the method was previously shown to determine surface tension of materials that would be particularly difficult to process by other means, e.g., liquid metals and alloys. It also offers distinct advantages in future work involving high viscosity samples because of the continuous forcing approach. This work presents (1) a benchmarking experimental method to measure surface tension by excitation of the second principal mode of oscillation (known as mode 3) in a levitated liquid droplet and (2) a more rigorous quantification of droplet excitation using a projection method. Surface tension measurements compare favorably to literature values for Zirconium, Inconel 625, and Rhodium, using both modes 2 and 3. Thus, this new method serves as a credible, self-consistent benchmarking technique for the measurement of surface tension.

A method is presented whereby the pressures, which are generated at the contact surfaces of two axisymmetrical components assembled together with an interference fit, can be determined. The approach of this method is to set up a series of influence coefficients for discrete matching nodal positions on the mating surfaces of the two components and to relate these by means of a matrix formulation, to the local nodal pressure and interference. Solution of the resulting set of linear simultaneous equations is readily performed by digital computer. The finite element approach for the determination of stresses and displacements in axisymmetrical components is used, in a somewhat modified form, to establish the influence coefficients at the surface of the outer component. While this same approach could be used for the inner component, in this present work, in order to emphasize the scope of the method, the inner component has been considered to be a solid shaft of infinite length for which influence coefficients derived from a “classical elasticity” approach can be used. Results are given for the pressure distribution along the contacting surface of a solid shaft when it is filled with axisymmetrical sleeves of various configurations—including rectangular, triangular, and stepped forms. The effect of using materials of different stiffness for the shaft and sleeve is analyzed, and the results obtained for the cases where the ratio of the material stiffness is very high and very low are compared with previously known solutions for these cases. The effect of using a varying interference is also considered. Full sets of computer programs, written in Fortran language, for each of the stages of the computation, together with detailed instructions for the compilation of input data, are presented.

Communicated by E. ZelmanovWe decompose the b sl(n)-module V (Λ 0 ) ⊗ V (Λ 0 ) and give generating function identities for the outer multiplicities. In the process we discover an infinite family of partition identities, which are seemingly new even in the n = 3 case.

We calculate the combinatorial R matrix for all elements of B l ⊗ B 1 where B l denotes the G 1 -crystalB 3l . The scattering rule for our soliton cellular automaton is identified with the combinatorial R matrix for A( 1) 1 -crystals.