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Articles 1 - 4 of 4
Full-Text Articles in Engineering
Application Of Computational Thermodynamic And Kinetic Models To Laser Surface Alloying, S S. Babu, S M. Kelly, R P. Martukanitz, M Murugananth
Application Of Computational Thermodynamic And Kinetic Models To Laser Surface Alloying, S S. Babu, S M. Kelly, R P. Martukanitz, M Murugananth
Faculty of Engineering - Papers (Archive)
Surface physical and mechanical properties can be tailored to different needs by the laser surface alloying process. These property modifications are made by localized melting of substrate material by laser beams with addition of alloying elements as well as hard particles. Through selection of proper hard particles, modification of underlying microstructure through rapid cooling and controlled alloying addition, one can tailor these surfaces for required properties. However, these processes are developed through extensive experimental trial-anderror methodology. This research shows an alternate design methodology by which these processes can be designed through computational thermodynamic and kinetic models.
The Effects Of Electrode Geometry On Current Pulse Caused By Electrical Discharge Over An Ultra-Fast Laser Filament, Matthew Bubelnik
The Effects Of Electrode Geometry On Current Pulse Caused By Electrical Discharge Over An Ultra-Fast Laser Filament, Matthew Bubelnik
Electronic Theses and Dissertations
The time-resolved electrical conductivity of a short-pulse generated plasma filament in air was studied. Close-coupled metal electrodes were used to discharge the stored energy of a high-voltage capacitor and the resulting microsecond-scale electrical discharge was measured using fast current sensors. Significant differences in the time dependence of the current were seen with the two electrode geometries used. Using sharp-tipped electrodes additional peaks in the time-resolved conductivity were seen, relative to the single peak seen with spherical electrodes. We attribute these additional features to secondary electron collisional ionization brought about by field enhancement at the tips. Additional discrepancies in the currents …
Laser Induced Fluorescence Photobleaching Anemometer For Microfluidic Devices, Guiren Wang
Laser Induced Fluorescence Photobleaching Anemometer For Microfluidic Devices, Guiren Wang
Faculty Publications
We have developed a novel, non-intrusive fluid velocity measurement method based on photobleaching of a fluorescent dye for microfluidic devices. The residence time of thefluorescent dye in a laser beam depends on the flow velocity and approximately corresponds to the decaying time of the photobleaching of the dye in the laser beam. The residence time is inversely proportional to the flow velocity. The fluorescence intensity increases with the flow velocity due to the decrease of the residence time. A calibration curve between fluorescence intensity and known flow velocity should be obtained first. The calibration relationship is then used to calculate …
Off-Axis Mgb2 Films Using An In Situ Annealing Pulsed Laser Deposition Method, Yue Zhao, Mihail Ionescu, Josip Horvat, S X. Dou
Off-Axis Mgb2 Films Using An In Situ Annealing Pulsed Laser Deposition Method, Yue Zhao, Mihail Ionescu, Josip Horvat, S X. Dou
Australian Institute for Innovative Materials - Papers
Highly smooth and c-axis oriented superconducting MgB2 thin films were prepared by pulsed laser deposition (PLD) with off-axis geometry. The films were deposited on Al2O3–C substrates perpendicularly aligned to a stoichiometric MgB2 target in a 120 mTorr high purity Ar background gas. An in situ annealing was carried out at 650 °C for 1 min in a 760 Torr Ar atmosphere. Despite the short annealing time, an x-ray θ–2θ scan shows fairly good crystallization, according to the clear c-axis oriented peaks for the films. Both atomic force microscopy and the x-ray diffraction …