Engineering topics

Chang, Hong

Publications and source records attributed to Chang, Hong.

2 records

DOE OSTI2019

Mn-induced ferromagnetism and enhanced thermoelectric properties in Ru 1- x Mn x Sb 2+ δ

We report the experimental investigation of Mn doping effect on the electrical, magnetic, and thermal properties of Ru 1-x Mn x Sb 2+δ single crystals. While RuSb 2+δ is a diamagnetic semiconductor, partial replacement of Ru by Mn results in ferromagnetism with the Curie temperature 536 K and 540 K for x = 0.04 and 0.08, respectively. Correspondingly, the electrical resistivity decreases dramatically and shows metallic character due to the increased electron concentration. Surprisingly, the magnitude of the thermopower increases upon Mn doping, reaching -250 μV K -1 at 300 K for x = 0.08, while the thermal conductivity remains unchanged above 100 K. These indicate a strong modification of electronic structure by doped Mn, leading to enhanced thermoelectric properties. The carriers induced by Mn not only decrease the resistivity, but also mediate the long-range ferromagnetic ordering in Ru 1-x Mn x Sb 2+δ .

36 MATERIALS SCIENCE↗

NASA NTRS2016

Motion Estimation Utilizing Range Detection-Enhanced Visual Odometry

A motion determination system is disclosed. The system may receive a first and a second camera image from a camera, the first camera image received earlier than the second camera image. The system may identify corresponding features in the first and second camera images. The system may receive range data comprising at least one of a first and a second range data from a range detection unit, corresponding to the first and second camera images, respectively. The system may determine first positions and the second positions of the corresponding features using the first camera image and the second camera image. The first positions or the second positions may be determined by also using the range data. The system may determine a change in position of the machine based on differences between the first and second positions, and a VO-based velocity of the machine based on the determined change in position.

Friend, Paul Russell↗