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Search Publications by: Thomas Brian Renegar (Fed)

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Displaying 1 - 25 of 87

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

Evaluating Measurement Uncertainty for Firearm Barrel and Overall Length Measurements

November 1, 2021
Author(s)
Michael Stocker, Theodore V. Vorburger, Thomas Renegar, Robert Thompson, Mark Williford
In recent years, more forensic laboratories are seeking accreditation to ISO 17020 and 17025. In the field of firearm and toolmark forensics, the barrel length and overall length of a firearm are typical measurements performed in the laboratory to

A Metrology Foundation for 3D Ballistic Imaging - NIJ Final Technical Report

September 1, 2021
Author(s)
Michael Stocker, Johannes Soons, Thomas Renegar, Xiaoyu Zheng, Robert Thompson
Forensic laboratories considering optical 3D surface topography measurement for objective comparison and VCM face challenges with respect to cost, training, and quality assurance. The primary aim of this research was to address quality assurance issues

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