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Nanoscale Structures And Fracture Processes In Advanced Ceramics: Million-Atom Md Simulations On Parallel Architectures., Andrey A. Omeltchenko
Nanoscale Structures And Fracture Processes In Advanced Ceramics: Million-Atom Md Simulations On Parallel Architectures., Andrey A. Omeltchenko
LSU Historical Dissertations and Theses
Properties and processes in silicon nitride and graphite are investigated using molecular-dynamics (MD) simulations. Scalable and portable multiresolution algorithms are developed and implemented on parallel architectures to simulate systems containing 10$\sp6$ atoms interacting via realistic potentials. Structural correlations, mechanical properties, and thermal transport are studied in microporous silicon nitride as a function of density. The formation of pores is observed when the density is reduced to 2.6 g/cc, and the percolation occurs at a density of 2.0 g/cc. The density variation of the thermal conductivity and the Young's modulus are well described by power laws with scaling exponents of 1.5 …
Photoemission Studies Of Magnetic Systems., Krishnan Subramanian
Photoemission Studies Of Magnetic Systems., Krishnan Subramanian
LSU Historical Dissertations and Theses
I have studied the electronic structure of thin films by photoelectron spectroscopy. My results show that even a monolayer film of Ni/Cu(001) exhibits bulk-like electronic structure and resembles that of bulk Ni. In order to better understand this result, I tracked the sp-band dimension at the Fermi surface of the Ni films for various coverages. For submonolayer coverages of Ni, the sp-band dimension was smaller than that of bulk Cu, but quickly reached that of bulk Ni by 1.2 ML Ni coverage. This continuous decrease implies a charge transfer from the Cu substrate to the Ni film, resulting in a …
A Study Of The Effect Of Energetic Flux Bombardment On Intensified Plasma-Assisted Processing., Albert Amatey Adjaottor
A Study Of The Effect Of Energetic Flux Bombardment On Intensified Plasma-Assisted Processing., Albert Amatey Adjaottor
LSU Historical Dissertations and Theses
An investigation of the plasma nitriding mechanism under intensified conditions (average particle energy up to 1200 eV) was carried out using a triode configuration. The significance of the different physical processes taking place during intensified plasma nitriding, such as sputtering, implantation, defect generation, redeposition and diffusion were investigated experimentally, while theoretical predictions were obtained by using the TRIM (transport of ions in matter) code. A titanium-base alloy was selected as the substrate material. Sputtering yield in an inert atmosphere was found to exhibit three regimes as a function of incoming particle energy. The low energy and high energy regimes were …
Cellulose-Reinforced Composites And Srim And Rtm Modeling., Mohammad Fahrurrozi
Cellulose-Reinforced Composites And Srim And Rtm Modeling., Mohammad Fahrurrozi
LSU Historical Dissertations and Theses
Structural reaction injection molding (SRIM) cellulosic/polyurethane composites were prepared from various forms of cellulosic mats, and elastomeric polyurea-urethane (PUU) and rigid polyurethane (PU) formulations. Mats (woven and non-woven) prepared from different sources of fibers with lignin content ranging from zero (cotton) to at least 10% (sugar cane and kenaf fibers) performed comparably in PUU/cellulosic composites. Young's modulus and tensile strength of PUU/cellulosic composites were doubled with 5% and 7% fiber loading respectively. Young's modulus and tensile strength of PU/cellulosic composites were improved by 300% and 30%, respectively, with 7% fiber loading, whereas their bending moduli and strengths were improved up …
Chemical Vapor Deposition Of Copper Films., Narendra Shamkant Borgharkar
Chemical Vapor Deposition Of Copper Films., Narendra Shamkant Borgharkar
LSU Historical Dissertations and Theses
We have studied the kinetics of copper chemical vapor deposition (CVD) for interconnect metallization using hydrogen (H$\sb2$) reduction of the Cu(hfac)$\sb2$ (copper(II) hexafluoroacetylacetonate) precursor. Steady-state deposition rates were measured using a hot-wall microbalance reactor. For base case conditions of 2 Torr Cu(hfac)$\sb2$, 40 Torr H$\sb2$, and 300$\sp\circ$C, a growth rate of 0.5 mg cm$\sp{-2}$ hr$\sp{-1}$ (ca. 10 nm min$\sp{-1}$) is observed. Reaction order experiments suggest that the deposition rate passes through a maximum at partial pressure of 2 Torr of Cu(hfac)$\sb2$. The deposition rate has an overall half-order dependence on H$\sb2$ partial pressure. A Langmuir-Hinshelwood rate expression is used to …