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Full-Text Articles in Engineering

Rational Design Of Cell Configurations For High-Performance Na-O2 Batteries, Xiaoting Lin Aug 2020

Rational Design Of Cell Configurations For High-Performance Na-O2 Batteries, Xiaoting Lin

Electronic Thesis and Dissertation Repository

Na-O2 batteries are considered as the promising candidates for electric vehicles due to their ultrahigh theoretical energy densities. However, state-of-the-art Na-O2 batteries suffer from serious challenges including 1) pore clogging and insufficient O2 transportation within the air electrode; 2) degradation of air electrode, 3) Na dendrite growth; and 4) Na corrosion induced by O2/O2- crossover. This thesis, therefore, focuses on rational design of cell configurations to address these problems and understanding the insight mechanisms.

3D printing of “O2 breathable” air electrodes for Na-O2 batteries were first developed. The unique air electrode …


Effects Of Corner Radii On Wind Tunnel Testing Of Low-Rise Buildings, Kytin Kwan Jul 2020

Effects Of Corner Radii On Wind Tunnel Testing Of Low-Rise Buildings, Kytin Kwan

Electronic Thesis and Dissertation Repository

Wind effects on buildings are commonly studied by testing 3D printed building models in a wind tunnel. A challenge with 3D printing is that the edges of these models may not be perfectly sharp, but rounded with a radius of curvature, R. It is well known that when edges are significantly rounded, the aerodynamics of the building can be altered (Robertson, 1991; Mahmood 2011), leading to inaccurate predictions of full-scale surface pressures and wind loads. However, there is presently no guidance on model edge radii prescribed in wind tunnel testing standards such as ASCE 49-12. The objective of the present …


Metal Additive Manufacturing For Fixed Dental Prostheses, Mai El Najjar Jun 2020

Metal Additive Manufacturing For Fixed Dental Prostheses, Mai El Najjar

Electronic Thesis and Dissertation Repository

The use of additive manufacturing (AM) in dentistry has gained momentum in recent years. However, high initial costs and uncertainty surrounding the quality of AM products are considered barriers to their use. This research compared dental substructures fabricated by AM versus conventional casting and milling.

Cobalt-chromium alloy rectangular bars and three-unit bridge substructures were fabricated by AM, casting or milling. Bars manufactured by AM exhibited superior flexural strength, shear bond strength of porcelain coating, and Vickers hardness. Bridge substructures fabricated by AM showed similar flexural stiffness to cast, similar flexural loads at failure to milled and cast, and overall accuracy …