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Search Publications by: Thomas Brian Renegar (Fed)

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Displaying 1 - 25 of 42

Sub-picoliter Traceability of Microdroplet Gravimetry and Microscopy

December 20, 2021
Author(s)
Lindsay C. C. Elliott, Adam L. Pintar, Craig R. Copeland, Thomas Brian Renegar, Ronald G. Dixson, Robert Ilic, R. Michael Verkouteren, Samuel M. Stavis
Volumetric analysis of single microdroplets is difficult to perform by ensemble gravimetry, whereas optical microscopy is often inaccurate beyond the resolution limit. To address the latter issue, we advance and integrate these complementary methods

Addressing Quality Assurance Issues in 3D Firearm and Toolmark Imaging

April 1, 2018
Author(s)
Michael T. Stocker, Robert M. Thompson, Johannes A. Soons, Thomas B. Renegar, Xiaoyu A. Zheng
The emerging capability for measuring and analyzing the three-dimensional (3D) surface topography of forensic samples is expected to have a profound impact on firearm and toolmark identification. As forensic laboratories are working to integrate 3D

The Second National Ballistics Imaging Comparison (NBIC-2)

January 5, 2015
Author(s)
Theodore V. Vorburger, James H. Yen, Jun-Feng Song, Robert M. Thompson, Thomas Brian Renegar, Xiaoyu Alan Zheng, D Ott, Martin G. Ols
In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, NIST and the ATF initiated a

Applications of Surface Metrology in Firearm Identification

January 8, 2014
Author(s)
Xiaoyu Alan Zheng, Johannes A. Soons, Theodore V. Vorburger, Jun-Feng Song, Thomas Brian Renegar, Robert M. Thompson
Surface metrology is commonly used to characterize functional engineering surfaces. The technologies developed offer opportunities to improve forensic toolmark identification. Toolmarks are created when a tool comes into contact with a surface and causes

Applications of Surface Metrology in Toolmark Identification

January 8, 2014
Author(s)
Xiaoyu Alan Zheng, Johannes A. Soons, Theodore V. Vorburger, Jun-Feng Song, Thomas Brian Renegar, Robert M. Thompson
Surface metrology is commonly used to characterize functional engineering surfaces. The technologies developed offer opportunities to improve forensic toolmark identification. In 2009, a report by the National Academies called into question, amongst others

The Effect of Tip Size in Calibration of Surface Roughness Specimens with Rectangular Profiles

September 2, 2013
Author(s)
Jun-Feng Song, Thomas B. Renegar, Johannes A. Soons, Balasubramanian Muralikrishnan, John S. Villarrubia, Xiaoyu A. Zheng, Theodore V. Vorburger
For the calibration of rectangular and trapezoidal profile roughness specimens, stylus tip will increase profile peak width and decrease valley width, which may cause the Ra changes (either increase or decrease, depends on the profile shape). Sometimes the

International Comparison of Surface Roughness, APMP.L-K8

June 17, 2013
Author(s)
Andrew Baker, Siew-Leng Tan, Richard Leach, Lena Jung, Seung Yin Wong, Anusorn Tonmueanwai, Kazuya Naoi, Jaewan Kim, Thomas Brian Renegar, K P Chaudhary, Louise Mostert, Mohamed Amer, Sitian Gao, Chin-Lung Tsai, Ngo N. Anh, Augustinus Drijarkara
Surface roughness calibration services of sixteen countries from four metrology regions are compared through measurements of roughness and step height standards. The artefacts circulated include three steps of nominal depths 0.4 μm, 2.4 μm and 10 μm

Topography Measurements and Performance Comparisons between NIST SRM 2460 Standard Bullet Masters and BKA Bullet Replicas

July 31, 2012
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Robert M. Thompson, Susan M. Ballou, Xiaoyu Alan Zheng, Thomas Brian Renegar, Richard M. Silver
Two Standard Reference Material (SRM) 2460 Bullets produced by the National Institute of Standards and Technology (NIST) were used as masters for the fabrication of replica bullets at the Bundeskriminalamt (BKA). The surface topography of the SRM masters

Development of Ballistics Identification - From Image Comparison to Topography Measurement in Surface Metrology-

March 22, 2012
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Robert M. Thompson, Thomas Brian Renegar, Xiaoyu Alan Zheng, James H. Yen, Richard M. Silver, Wei Chu
Fired bullets and ejected cartridge cases have unique ballistics signatures left by the firearm. By analyzing the ballistics signatures, forensic examiners can trace these bullets and cartridge cases to the firearm used in a crime scene. Current automated

Stylus Tip-Size Effect on the Calibration of Periodic Roughness Specimens with Rectangular Profiles

March 21, 2012
Author(s)
Thomas B. Renegar, Johannes A. Soons, Balasubramanian Muralikrishnan, John S. Villarrubia, Xiaoyu A. Zheng, Theodore V. Vorburger, Jun-Feng Song
Stylus instruments are widely used for surface characterization. It is well known that the size and shape of the stylus tip affects the measured surface geometry and parameters. In most cases, increasing the tip size decreases the measured Ra value because

The National Ballistics Imaging Comparison (NBIC) Project

March 10, 2012
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou, Robert M. Thompson, James H. Yen, Thomas Brian Renegar, Xiaoyu Alan Zheng, Richard M. Silver, Martin Ols
In response to the guidelines issued by the ASCLD/LAB-International (American Society of Crime Laboratory Directors/Laboratory Accreditation Board) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project

An Iterative Algorithm for Calculating Stylus Radius Unambiguously

September 24, 2011
Author(s)
Theodore V. Vorburger, Xiaoyu A. Zheng, Thomas B. Renegar, Jun-Feng Song, Li Ma
The stylus radius is an important specification for stylus instruments and is commonly provided by instrument manufacturers. However, it is difficult to measure the stylus radius unambiguously. Accurate profiles of the stylus tip may be obtained by

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

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

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

NIST SRM (Standard Reference Material) 2460/2461 Standard Bullets and Casings Project

October 13, 2009
Author(s)
Jun-Feng Song, Thomas Brian Renegar, Xiaoyu Alan Zheng, Robert M. Thompson, Richard M. Silver, Martin M. Ols, Ted T. Vorburger
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 Cartridge Cases. NIST has also

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

Surface Topography Analysis for a Feasibility Assessment of a National Ballistics Imaging Database

May 1, 2007
Author(s)
Theodore V. Vorburger, James H. Yen, B Bachrach, Thomas Brian Renegar, Li Ma, Hyug-Gyo Rhee, Xiaoyu Alan Zheng, Jun-Feng Song, Charles D. Foreman
This document reports on a study to determine the feasibility and utility of a national ballistics database of casing and bullet images. The purpose of such a proposed database would be to provide a reference collection of ballistic images against which

Comparison of Optical and Stylus Methods for Measurement of Rough Surfaces

January 1, 2007
Author(s)
Theodore V. Vorburger, H G. Rhee, Thomas B. Renegar, Jun-Feng Song, Xiaoyu A. Zheng
Abstract Optical methods are increasingly used for measurement of surface texture, particularly for areal measurements where the optical methods are generally faster. A new Working Group under Technical Committee (TC) 213 in the International Organization

NIST Standard Bullets and Casings Project

January 1, 2007
Author(s)
Jun-Feng Song, Theodore V. Vorburger, Susan M. Ballou, Thomas Brian Renegar, Li Ma, Eric P. Whitenton, David R. Kelley, Robert A. Clary, A Zheng, M Ols
The National INstitute of Standards and Technology (NIST) standard bullets and casings project will provide support to firearm examiners and to the National Integrated Ballistics Information Network (NIBIN) in the United States. The standard bullet is