Data from a state department of transportation fleet shows that the usage of a typical asset decreases as it ages. One possible explanation for decreasing asset usage with age is operator preference for using the newest available asset. In this research the long-term cost and replacement implications of such a...
Oregon Department of Transportation (ODOT) Fleet Services manages a fleet that in 2008 included approximately 5,000 pieces of active equipment worth $340–$390 million. Every biennium, a fixed budget is available to replace a certain amount of this equipment. This research evaluated various measures for establishing equipment replacement priorities.
A model...
Crystal morphology and dimensionality of single-crystal semiconducting materials can have dramatic effects on the optical and electrical properties. Organic photovoltaic (OPV) materials and fluorinated graphene folds are two materials that show these dependencies. Anthradithiophene (ADT), is an OPV that can be functionalized with different side groups to form different crystal...
The photophysical properties of two-dimensional (2D) layered van der Waals (vdW) materials, and their heterostructures are manifestly distinct from crystalline bulk materials. Recently, the discovery of new 2D vdW materials and strongly-bound interlayer excitons in these materials has created a new branch in nanoscience. As such, there are a number...
To assist with risk-assessment with deepwater and ultra-deepwater prospects for offshore energy extraction as well as provide a useful tool for oil spill response, a spatially-explicit model was developed for comprehensive simulations of a blowout event from the wellhead to final fate and degradation. The Blowout and Spill Occurrence Model...
The Kane Oceanic Core Complex (OCC) is a valuable window into crustal architecture and chemical composition of the lithosphere beneath a slow-spreading ocean ridge. A suite of > 30 samples (comprised of whole rocks, mineral separates and basalt glasses) has been analyzed for ³He/⁴He isotope ratios and He concentrations. Gas...
The optical and electronic properties of amorphous oxide thin films depend crucially on chemical composition, and deposition process variations which give rise to sub-gap defect states. Consequently, there is a need for a reliable, high-throughput method to extract sub-gap defect densities of states in amorphous oxide thin films. We present...
Electron behavior in semiconductor materials critically determines electronic applications. Previous research has shown carrier temperature higher than the lattice temperature of LEDs due to energy differences in the quantum well. Study of these findings requires a novel set-up to dig out weak signal in a thermal-noise filled environment; analytical methods...
Understanding the electrical transport properties of graphene provides a basis for determining its future as a potential semiconducting device that can be used for the next generation of transistors and photodetectors. Graphene p-n junctions can also function as field effect transistors, and thus are a logical starting point for I-V...
Organic aggregates and transparent amorphous metals are transforming opto-electronic devices such as highly efficiency solar cells and flexible displays. We present a fundamental optical study of how local morphology critically impacts the device performance of both stacked, conjugated organics and In-Ga-Zn-O (IGZO) transparent metallic materials. Derivatives of anthradithiophene (ADT): ADTTES-F,...