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Search Publications by

Nicholas Ritchie (Fed)

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Displaying 1 - 16 of 16

Reference Material 8634: Ethylene Tetrafluoroethylene for Particle Size Distribution and Morphology

May 1, 2019
Dean C. Ripple, Srivalli Telikepalli, Kristen L. Steffens, Michael J. Carrier, Christopher B. Montgomery, Nicholas W. Ritchie, John Lu
Reference Material (RM) 8634 is a NIST particle standard produced from abraded ethylene tetrafluoroethylene (ETFE), a chemically inert polymer, that will help standardize and allow more accurate monitoring of subvisible proteinaceous particles in

Solidification of Ni-Re Peritectic Alloys

February 4, 2019
William J. Boettinger, Dale E. Newbury, Nicholas W. Ritchie, Maureen E. Williams, Ursula R. Kattner, Eric Lass, Kil-Won Moon, Michael B. Katz
Differential thermal analysis (DTA) and microstructural and microprobe measurements of DTA and as-cast Ni-Re alloys with compositions between 0.20 and 0.44 mass fraction Re provide information to resolve differences in previously published Ni-Re phase

Chemical Compound Classification by Elemental Signatures in Castle Dust Using SEM Automated X-ray Particle Analysis

August 1, 2018
Diana Ortiz-Montalvo, Edward P. Vicenzi, Nicholas W. Ritchie, Carol A. Grissom, Richard A. Livingston, Zoe Weldon-Yochim, Joseph M. Conny, Scott A. Wight
Discoloration on the Smithsonian Institution Building and Enid A. Haupt Garden gateposts was recently revealed to be related to a Mn enriched rock varnish. Mn does not appear to be derived locally from the building stone; therefore, its source is likely

SEM/EDS Trace Analysis: Limits Imposed by Fluorescence of the Detector

August 4, 2017
Dale E. Newbury, Nicholas W. Ritchie, Michael J. Mengason, Keana C. Scott
Elemental trace analysis by electron-excited x-ray spectrometry performed in the scanning electron microscope (SEM) with energy dispersive x-ray spectrometry (EDS) can reach a limit of detection of 0.0005 mass fraction for many elements. Exceptions include

Certification of New Standard Reference Material 2806b Medium Test Dust in Hydraulic Oil

December 19, 2016
Robert A. Fletcher, Nicholas W. Ritchie, David S. Bright, James J. Filliben, William F. Guthrie
A new material has been certified to become Standard Reference Material (SRM) 2806b - Medium Test Dust in Hydraulic Fluid. SRM 2806b consists of a trace polydisperse, irregularly shaped mineral dust particles suspended in hydraulic fluid. The certified

Microscopy and Microanalysis of Individual Collected Particles- Chapter 10

July 5, 2011
Robert A. Fletcher, Nicholas W. Ritchie, Ian M. Anderson, John A. Small
This chapter describes microscopy and microanalysis techniques used for the characterization of collected, individual particles in a variety of instruments. The instruments discussed are the light microscope, electron microscopes (both scanning and

Bridging the Micro to Macro Gap: A New Application for Milli-probe X-ray Fluorescence

June 1, 2011
Jeffrey M. Davis, Dale E. Newbury, Nicholas W. Ritchie, Edward P. Vicenzi, Dale P. Bentz, Albert J. Fahey
X-ray elemental mapping and x-ray spectrum imaging are powerful microanalytical tools. However, their scope is limited spatially by the raster area of a scanning electron microscope or microprobe. Limited sampling size becomes a significant issue when

Characterization of SiGe Films for use as a National Institute of Standards and Technology (NIST) Microanalysis Reference material (RM 8905)

February 1, 2010
Ryna B. Marinenko, Shirley Turner, David S. Simons, Savelas A. Rabb, Rolf L. Zeisler, Lee L. Yu, Dale E. Newbury, Rick L. Paul, Nicholas W. Ritchie, Stefan D. Leigh, Michael R. Winchester, Lee J. Richter, Douglas C. Meier, Keana C. Scott, D Klinedinst, John A. Small
Bulk SiGe wafers cut from single-crystal boules and two SiGe thick films (4 m and 5 m thick) on Si wafers were evaluated with the electron probe microanalyzer for the extent of heterogeneity and composition for use as reference materials needed by the

Spectrum Simulation in DTSA-II

October 1, 2009
Nicholas W. Ritchie
Spectrum simulation is a useful practical and pedagogical tool. Particularly with complex samples or trace constituents, a simulation can help to understand the limits of the technique and how to optimize the tools for the optimal measurement. DTSA-II