Search

Your search keyword '"Wilson, James N."' showing total 2 results
Start Over Author "Wilson, James N." Publisher american institute of physics
2 results on '"Wilson, James N."'

1. Metallurgical analysis and computer simulation of a solid steel sphere under shock loading.

Author

Wilson, James N., Hashemi, Javad, James, Darryl, Gu¨ven, Necip, Dallas, Tim, Kuhrts, Kurtis, Combs, Bret, Hale, Michael, and Willson, Grant

Subjects
*STEEL, *METALLURGICAL analysis, *COMPUTER simulation, *METALLIC surfaces, *HARDNESS
Abstract

An explosive-based spherical shock-recovery system was used to load an annealed solid steel sphere. The hydrocode CTH was utilized to model the explosive-metal interaction. Based on the simulation results, pressures reached as high as 100 GPa (1 Mbar) at the surface and converged to 1.25 TPa (12.5 Mbar) at the center of the sphere. As the computer simulation predicted, post-shock examination of the recovered sphere revealed a large void at its center created as a result of strong tensile waves emanating from the surface. Micro-hardness measurements showed a hardness at the surface of the sphere approximately twice the hardness at its center. X-ray analysis of the pre and post shocked samples revealed no permanent phase transformation. [ABSTRACT FROM AUTHOR]

Published
2000

2. Photoresponsivity of polymer thin-film transistors based on polyphenyleneethynylene derivative with improved hole injection.

Author

Yifan Xu, Berger, Paul R., Wilson, James N., and Bunz, Uwe H.F.

Subjects
*POLYMERS, *TRANSISTORS, *FIELD-effect transistors, *AROMATIC compounds, *THIN films, *PHYSICS
Abstract

The photoresponse of polymer field-effect transistors (PFETs) based on the 2,5-bis(dibutylaminostyryl)-1,4-phenylene-b-alkyne-b-1,4-bis(2-ethylhexyl)benzene terpolymer (BAS-PPE) is investigated. BAS-PPE is a photoluminescent conducting polymer with a band gap of 2.25 eV. The BAS-PPE PFETs were fabricated using an open coplanar configuration and light is illuminated onto the top side of the PFETs with no shadowing present. A sweep of VDS demonstrates that IDS saturation is suppressed during illumination, which suggests that pinch-off cannot be reached since the injected photogenerated carriers continue unabated. Also, with incident light, the channel cannot be turned off, even at high positive gate biases, due to the accumulation of photogenerated carriers. A sweep of VDS shows that BAS-PPE can act as a p-type polymer and favors hole injection and transport. A sweep of VGS shows an increase in IDS with different light intensities. The Ilight/Idark ratio reaches as high as about 6000 at an incident light intensity of 4 μW and a photoresponsivity of 5 mA/W is calculated. [ABSTRACT FROM AUTHOR]

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results