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X-Ray Microbeam Measurement of Local Texture and Strain in Metals (open access)

X-Ray Microbeam Measurement of Local Texture and Strain in Metals

Synchrotron x-ray sources provide high-brilliance beams that can be focused to submicron sizes with Fresnel zone-plate and x-ray mirror optics. With these intense, tunable or broad-bandpass x-ray microbeams, it is now possible to study texture and strain distributions in surfaces, and in buried or encapsulated thin films. The full strain tensor and local texture can be determined by measuring the unit cell parameters of strained material. With monochromatic or tunable radiation, at least three independent reflections are needed to determine the orientation and unit cell parameters of an unknown crystal. With broad-bandpass or white radiation, at least four reflections and one measured energy are required to determine the orientation and the unit cell parameters of an unknown crystal. Routine measurement of local texture and strain is made possible by automatic indexing of the Laue reflections combined with precision calibration of the monochromator-focusing mirrors-CCD detector system. Methods used in implementing these techniques on the MHA-IT-CAT beam line at the Advanced Photon Source will be discussed.
Date: April 6, 1999
Creator: Chung, J. -S.; Tamura, N.; Ice, G. E.; Larson, B. C.; Budai, J. D. & Lowe, W.
Object Type: Article
System: The UNT Digital Library
Year 2000 Computing Challenge: Readiness of Key State-Administered Federal Programs (open access)

Year 2000 Computing Challenge: Readiness of Key State-Administered Federal Programs

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the year 2000 readiness of state-administered federal programs, focusing on: (1) the reported year 2000 readiness of 10 key state-administered federal human services programs; and (2) federal activities to assess states' readiness for these 10 programs."
Date: October 6, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Year 2000 Computing Crisis: Readiness of the Electric Power Industry (open access)

Year 2000 Computing Crisis: Readiness of the Electric Power Industry

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the electric power industry's vulnerability to year 2000 problems and the reported status of the industry's year 2000 readiness."
Date: April 6, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library