Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening (open access)

Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening

Article describes study in which researchers attribute the 600% increase in creep life in a prototypical Mg–rare earth (RE)–Zn alloy to multiple mechanisms caused by RE–Zn bonding—stabilization of a large volume fraction of strengthening precipitates on slip planes, increase in vacancy diffusion barrier, reduction in activated cross-slip, and enhancement of covalent character and bond strength around Zn solutes along the c-axis of Mg using atomic-scale characterization and first principles calculations.
Date: December 8, 2017
Creator: Choudhuri, Deep; Srivilliputhur, Srinivasan; Gibson, Mark A.; Zheng, Yufeng; Jaeger, David L.; Fraser, Hamish L. et al.
System: The UNT Digital Library
Algorithmically Optimized Hemispherical Dome as a Secondary Optical Element for the Fresnel Lens Solar Concentrator (open access)

Algorithmically Optimized Hemispherical Dome as a Secondary Optical Element for the Fresnel Lens Solar Concentrator

This article focuses on a way to maximize the concentration acceptance product (CAP), while using the minimum SOE and receiver geometry at a given f-number and incidence angle (also referred to as the tracking error angle). The laws of polychromatic light refraction along with trigonometry and spherical geometry were utilized to optimize the POE grooves, SOE radius, receiver size, and SOE–receiver spacing.
Date: July 8, 2019
Creator: Qandil, Hassan; Wang, Shuping & Zhao, Weihuan
System: The UNT Digital Library