Nanoparticles and the influence of interface elasticity

In this manuscript, we discuss the influence of surface and interface stress on the elastic field of a nanoparticle, embedded in a finite spherical substrate. We consider an axially symmetric traction field acting along the outer boundary of the substrate and a non-shear uniform eigenstrain field inside the particle. As a result of axial symmetry, two Papkovitch-Neuber displacement potential functions are sufficient to represent the elastic solution. The surface and interface stress effects are fully represented utilizing Gurtin and Murdoch's theory of surface and interface elasticity. These effects modify the traction-continuity boundary conditions associated with the classical continuum elasticity theory. A complete methodology is presented resulting in the solution of the elastostatic Navier's equations. In contrast to the classical solution, the modified version introduces additional dependencies on the size of the nanoparticles as well as the surface and interface material properties

Atomistic calculations of interface elastic properties in noncoherent metallic bilayers

The paper describes theoretical and computational studies associated with the interface elastic properties of noncoherent metallic bicrystals. Analytical forms of interface energy, interface stresses, and interface elastic constants are derived in terms of interatomic potential functions. Embedded-atom method potentials are then incorporated into the model to compute these excess thermodynamics variables, using energy minimization in a parallel computing environment. The proposed model is validated by calculating surface thermodynamic variables and comparing them with preexisting data. Next, the interface elastic properties of several fcc-fcc bicrystals are computed. The excess energies and stresses of interfaces are smaller than those on free surfaces of the same crystal orientations. In addition, no negative values of interface stresses are observed. Current results can be applied to various heterogeneous materials where interfaces assume a prominent role in the systems' mechanical behavior.open322

Workshops vs. . . . PROGRAM IS CHANGING THE WAY ENGINEERING STUDENTS LEARN

... retention efforts through their Academic Excellence Program. This program housed two components: peer tutoring and mentoring and group workshops. While both produced successful retention rates among minority students within the College, both students and faculty strongly expressed a need for a more structured and intensive program to assist engineering students with the more challenging courses. In fall of 2000, ASU’s MEP remodeled their efforts at retention and created the Academic Excellence Workshop program. The workshop program replaces tutoring and mentoring programs with weekly workshop sessions. This non-traditional approach to academic support has necessitated a change in paradigm for staff, faculty, and students. The response to this change has been promising. This paper will discuss the AEW program structure and how the workshop concept has been promoted to students and faculty. Index Terms – Workshop session format, group-learning, faculty/student/staff collaboration, workshop marketin