https://hdl.handle.net/11256/12 2026-04-08T11:36:53Z https://hdl.handle.net/11256/1003 Calculated Collision Welding Process Windows in Acoustic, Elastic, and Shock Approximations Barnett, Blake Collision welding is a solid-state joining process which uses shock pressures developed during impact to metallurgically bond flyer and target plates. Various analytical expressions have been developed to describe the process boundaries for ideal welds in the welding velocity-impact angle plane. Existing process boundaries assume symmetric weld members, and/or symmetric post-impact weld behavior (stress partitioning and propagation velocities, peak temperatures, and cooling rates) which are not applicable to the majority of collision welding applications, which use dissimilar weld members. This work extends and modifies existing weld window boundaries through the application of elementary shock physics (Rankine-Hugoniot Relations) via discrete numerical calculations for permutations of weld pairs across approximately 30 elemental and alloy metals. Existing formulations of relevant process boundaries are also included for completeness. The MATLAB program used to generate the datasets and associated plots can be found on GitHub at: https://github.com/BBarnett-615/Collision-Welding-Process-Window-Calculator https://hdl.handle.net/11256/994 Cubic crystal compounds - Jarvis DFT Kaundinya, Prathik This is the dataset of materials obtained from the Jarvis-DFT dataset and used for the study "Machine learning approaches for feature engineering of the crystal structure: Application to the prediction of the formation energy of cubic compounds". https://hdl.handle.net/11256/951 HiPerC Spinodal Decomposition Benchmark Results Keller, Trevor https://hdl.handle.net/11256/105 Sensitivity of gold nano conductors to voids, substitutions and electric field: ab initio results Barzilai, Shmuel; Tavazza, Francesca; Levine, Lyle E. Gold nanowires are good candidates for nanoelectronics devices. A previous study has shown that the beryllium terminated BeO (0001) surface may be a useful platform for supporting nano gold conductors, since it preserves the nano-wire configuration and does not restrict its conductivity. Here, we used ab initio simulations to determine the sensitivity of potential gold nano-conductors to the presence of point defects, O2 substitutions and to an applied perpendicular electric field, as in field effect transistors. We found that the presence of the point defects cause only small changes in the atomic bond lengths of the NW, does not alter the NW configuration, but may affect the overall conductivity. The conductive ability of the conductor depends on the available conductive channels. Single or double voids on the same channel reduce the conductance by 28 % at most, but when the voids arrange in a way that only one channel remains for conductance, it reduces by factor of two to ≈ 1 G0 (G0 = 2e2/h). The presence of a single O2 molecule as a substitution reduces the electron availability in the neighboring Au atoms, in most cases reducing the conductance. The perpendicular electric field, which is typical for field effect transistors, affects the electron density distribution, shifts and changes the conductance spectra profile, but does not decrease the conductivity. 2014-09-26T00:00:00Z