Sabrina J Poon

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Measures of episodic memory are often used to identify Alzheimer's disease (AD) and mild cognitive impairment (MCI). The Neuropsychological Assessment Battery (NAB) List Learning test is a promising tool for the memory assessment of older adults due to its simplicity of administration, good psychometric properties, equivalent forms, and extensive normative(More)
Half-Heuslers would be important thermoelectric materials due to their high temperature stability and abundance if their dimensionless thermoelectric figure of merit (ZT) could be made high enough. The highest peak ZT of a p-type half-Heusler has been so far reported about 0.5 due to the high thermal conductivity. Through a nanocomposite approach using ball(More)
The toughness of Fe-based bulk metallic glasses BMGs has been significantly improved via systematic changes in chemistry. Chemistry changes were selected based on their likely effects on critical elastic constants shown to affect plasticity/toughness in various BMGs, in addition to their recently discovered effects on chemical bonding in these Fe-based(More)
V. Yu. Kazimirov,1 Despina Louca,1 M. Widom,2 X.-J. Gu,1 S. J. Poon,1 and G. J. Shiflet3 1Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA 2Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA 3Department of Materials Science and Engineering, University of Virginia, Charlottesville,(More)
The synthesis and properties of a class of metallic glasses containing up to 90 atomic percent aluminum are reported. The unusual formability of the glasses and their structural features are pointed out. Mechanical properties including tensile fracture strength and Young's modulus are reported along with crystallization temperatures. The unusually high(More)
Systematic changes in composition were employed to increase the notch toughness of a variety of Fe-based Bulk Metallic Glasses (BMGs). The Fe50Mn10Mo14Cr4C16B6 BMG possessed very high hardness (e.g. 12GPa) but very low notch toughness (e.g. 5.7MPam) at room temperature, consistent with fracture surface observations of brittle features. Many of the other(More)
BACKGROUND Surgical safety checklists, such as the perioperative time-out, have been shown to improve performance on a variety of patient safety measures. A variety of methods have been used to assess compliance with the perioperative time-out, but no standardized methodology with a reliable observer group currently exists. An observation-based methodology(More)
Half-Heusler alloys ~MgAgAs type! with the general formula MNiSn where M is a group IV transition metal ~Hf, Zr, or Ti! are currently under investigation for potential thermoelectric materials. These materials exhibit a high negative thermopower (240 to 2250 mV/K) and low electrical resistivity values ~0.1–8 mV cm! both of which are necessary for a(More)
New phases of the type La2-xAx(l+)CUO4-y have been prepared where A(l+) is sodium or potassium. The sodium phases are superconducting for x values from 0.2 to 0.5 at temperatures up to about 40 K. In addition, there are unusual magnetic properties below about 10 K that may be indicative of spin glass behavior. Phases of the type La2-xKxCuO4-y could only be(More)