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Search Publications by: Theodore V. Vorburger (Assoc)

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Displaying 26 - 50 of 209

Striation Density for Predicting the Identifiability of Fired Bullets

September 1, 2010
Author(s)
Wei Chu, Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou
Without a selection procedure to exclude the bullets having insufficient individualized ballistics signature, automated ballistics identification systems will correlate an evidence bullet with all reference bullets stored in the database. Correlations that

Topography measurements for correlations of standard cartridge cases

July 1, 2010
Author(s)
Theodore V. Vorburger, Jun-Feng Song, Wei Chu, Thomas Brian Renegar, Xiaoyu Alan Zheng, James H. Yen, Robert M. Thompson, Richard M. Silver, Benjamin Bachrach, Martin Ols
NIST Standard Reference Materials (SRM) 2460 Standard Bullets and 2461 Standard Cartridge Cases are intended for use as check standards for crime laboratories to help verify that their computerized optical imaging equipment for ballistics image

Interlaboratory Comparison of Traceable Atomic Force Microscope Pitch Measurements

June 14, 2010
Author(s)
Ronald G. Dixson, Donald Chernoff, Shihua Wang, Theodore V. Vorburger, Ndubuisi G. Orji, Siew-Leng Tan, Joseph Fu
The National Institute of Standards and Technology (NIST), Advanced Surface Microscopy (ASM), and the National Metrology Centre (NMC) of the Agency for Science, Technology, and Research (A*STAR) in Singapore have undertaken a three-way interlaboratory

Introduction to Surface Finish Metrology

June 14, 2010
Author(s)
Theodore V. Vorburger
We discuss the range of methods available to measure surface finish and emphasize the methods of stylus profiling and various types of optical profiling. Documentary standards for measurement of surface texture and comparisons between methods are also

Applications of Cross-Correlation Functions

April 14, 2010
Author(s)
Theodore V. Vorburger, Jun-Feng Song, Wei Chu, Li Ma, Xiaoyu A. Zheng, Thomas B. Renegar, Son H. Bui
We describe several examples where we use cross-correlation functions to quantify the similarity of 2D surface profiles or of 3D surface topography images. The applications have included 1) the manufacture of Standard Reference Material (SRM) bullets and

Calibration of 1 nm SiC Step Height Standards

March 31, 2010
Author(s)
Theodore V. Vorburger, Albert M. Hilton, Ronald G. Dixson, Ndubuisi G. Orji, J. A. Powell, A. J. Trunek, P. G. Neudeck, P. B. Abel
We aim to develop and calibrate a set of step height standards to meet the range of steps useful for nanotechnology. Of particular interest to this community is the calibration of atomic force microscopes operating at their highest levels of magnification

Three steps towards metrological traceability for ballistics signature measurements

February 1, 2010
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Robert M. Thompson, Thomas Brian Renegar, Xiaoyu Alan Zheng, Li Ma, James H. Yen, Martin Ols
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 bullets and 2461 casings. NIST and ATF are proposing to

Traceability for Ballistics Signature Measurements in Forensic Science

December 1, 2009
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou, Li Ma, Thomas Brian Renegar, Xiaoyu Alan Zheng, Martin Ols
The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D

Influence of room temperature control system on AFM imaging

October 1, 2009
Author(s)
Joseph Fu, Wei Chu, Theodore V. Vorburger
As technology progresses, the control of environment for experiments is also getting more sophisticated; such as the control of lab temperature and vibration. Temperature controlled within ± 0.25° C for a general purpose lab is common place. We illustrate

A moving window correlation method to reduce the distortion of SPM images

August 20, 2009
Author(s)
Wei Chu, Joseph Fu, Ronald G. Dixson, Ndubuisi G. Orji, Theodore V. Vorburger
Many scanning probe microscopes (SPMs), such as the scanning tunneling microscope (STM) and atomic force microscope (AFM), use piezoelectric actuators operating in open loop for generating the scans of the surfaces. However, nonlinearities mainly caused by

Reference Metrology in a Research Fab: The NIST Clean Calibrations Thrust

April 12, 2009
Author(s)
Ronald G. Dixson, Ndubuisi G. Orji, Joseph Fu, Thomas B. Renegar, Xiaoyu A. Zheng, Theodore V. Vorburger, Albert M. Hilton, Marc J. Cangemi, Lei Chen, Michael A. Hernandez, Russell E. Hajdaj, Michael R. Bishop, Aaron Cordes
In 2004, the National Institute of Standards and Technology (NIST) commissioned the Advanced Measurement Laboratory (AML) – a state-of-the-art, five-wing laboratory complex for leading edge NIST research. The NIST NanoFab – a 1765 m2 (19,000 ft2) clean

Evaluation of Polydimethylsiloxane Modification Methods for Cell Response

February 20, 2009
Author(s)
Lisa Pakstis, Alan Zheng, Theodore V. Vorburger, Joy P. Dunkers, Timothy P. Quinn, Marcus T. Cicerone
Many methods exist in the literature to modify surfaces with extracellular matrix (ECM) proteins prior to cell attachment. However, there are few studies that systematically compare surface characterization and cell response results among different

2nd Annual Tri-National Workshop on Standards for Nanotechnology - (NIST presentations)

December 10, 2008
Author(s)
Ronald G. Dixson, Jon R. Pratt, Vincent A. Hackley, James E. Potzick, Richard A. Allen, Ndubuisi G. Orji, Michael T. Postek, Herbert S. Bennett, Theodore V. Vorburger, Jeffrey A. Fagan, Robert L. Watters
A new era of cooperation between North American National Measurement Institutes (NMIs) was ushered by the National Research Council of Canada Institute for National Measurement Standards (NRC-INMS) on February 7, 2007 when the first Tri-National workshop

Topography Measurements for Determining the Decay Factors in Surface Replication

July 4, 2008
Author(s)
Jun-Feng Song, P Rubert, Xiaoyu A. Zheng, Theodore V. Vorburger
The electro-forming technique is used at National Institute of Standards and Technology (NIST) for the production of standard reference material (SRM) 2461 standard casings to support nationwide ballistics measurement traceability and measurement quality

Nano- and Atomic-Scale Length Metrology

December 14, 2007
Author(s)
Theodore V. Vorburger, Ronald G. Dixson, Joseph Fu, Ndubuisi G. Orji, Shaw C. Feng, Michael W. Cresswell, Richard A. Allen, William F. Guthrie, Wei Chu