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Search Publications by: Andrew J Allen (Fed)

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Displaying 76 - 100 of 129

Development of Ultrasmall-Angle X-ray Scattering - X-ray Photon Correlation Spectroscopy

February 1, 2011
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Jan Ilavsky, Gabrielle G. Long, Anthony M. Santana
In this paper, we present the development of ultrasmall-angle X-ray scattering - X-ray photon correlation spectroscopy (USAXS-XPCS). This technique takes advantage of Bonse-Hart crystal optics and is capable of probing the slow equilibrium and

Multi-Scale Pore Morphology in Vapor-Deposited Yttria-Stabilized Zirconia Coatings

June 16, 2010
Author(s)
Derek D. Hass, H. Zhao, Tabbetha A. Dobbins, Andrew J. Allen, Andrew Slifka, H. N. Wadley
A high pressure, electron-beam directed-vapor deposition process has been used to deposit partially stabilized zirconia containing 7 % yttria by mass at deposition pressures of 7.5 Pa to 23 Pa. Anisotropic ultra-small-angle X-ray scattering (USAXS) was

Glassy Carbon as an Absolute Intensity Calibration Standard for Small Angle Scattering

August 19, 2009
Author(s)
Andrew J. Allen, Jan Ilavsky, Fan Zhang, Gabrielle G. Long, Pete R. Jemian
Absolute calibration of small-angle scattering (SAS) intensity data (in units of differential cross-section per unit sample volume per unit solid angle) is essential for many important aspects of quantitative SAS analysis, such as obtaining the number

Characterization of Fly Ash Reactivity in Hydrating Cement by Neutron Scattering

July 14, 2009
Author(s)
W Bumrongjaroen, Richard A. Livingston, Dan A. Neumann, Andrew J. Allen
A combination of small-angle and inelastic neutron scattering studies are presented to elucidate the different effects of Class F and Class C fly ash additions on microstructure development in hydrating cement (and concrete). Small angle neutron scattering

Ultra-small-angle X-ray scattering at the Advanced Photon Source

June 12, 2009
Author(s)
Pete R. Jemian, Jan Ilavsky, Andrew J. Allen, Fan Zhang, Lyle E. Levine, Gabrielle G. Long
The design and operation of a versatile ultra-small-angle X-ray scattering (USAXS) instrument at the Advanced Photon Source (APS) at Argonne National Laboratory are presented. The instrument is optimized for the high brilliance and low emittance of an APS

Process-Controlled Plasma-Sprayed Yttria-Stabilized Zirconia Coatings: New Insights from

February 11, 2009
Author(s)
Y Li, W Chi, S Sampath, A N. Goland, H Herman, Andrew J. Allen, J Ilavsky
A multi-component microstructure model is applied in ultrasmall-angle X-ray scattering (USAXS) studies of the processing microstructure property relationships for two groups of plasma-sprayed yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs)

Analysis of C-S-H Gel and Cement Paste by Small-Angle Neutron Scattering

January 16, 2007
Author(s)
Andrew J. Allen, J Thomas
The role of small-angle x-ray and neutron scattering (SAXS and SANS) in the characterization of cement is briefly reviewed. The unique information obtainable from SANS analysis of C-S-H gel in hydrating cement is compared with that obtainable by other

Composition and Density of Amorphous Calcium-Silicate-Hydrate in Cement

January 16, 2007
Author(s)
Andrew J. Allen, J Thomas, Hamlin M. Jennings
Despite intensive research for over a century, the main binding reaction product of cement hydration, calcium-silicate-hydrate (C-S-H) gel, is not fully understood. By combining absolute-calibrated small-angle and ultrasmall-angle neutron and x-ray

Growth of Nanocrystalline Ceria Studied Using a USAXS Capillary Flow-Cell

July 1, 2006
Author(s)
Vincent A. Hackley, Andrew J. Allen, P R. Jemian, J M. Raitano, S W. Chan
Nanocrystalline ceria particles, with dimensions as small as 2 nm, have been prepared at room temperature by a soft chemical route using aqueous cerium nitrate and hexamethylenetetramine (HMT) as reactants. HMT decomposes slowly in aqueous solution