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Displaying 451 - 475 of 2605

A Multireflect-Thru Method of Vector-Network-Analyzer Calibration

March 1, 2017
Author(s)
Arkadiusz Lewandowski, Wojciech Wiatr, Nate Orloff, James Booth
We present a new method for two-port vector-network-analyzer calibration which uses multiple offset-reflect standards and a flush thru connection. Offset-reflect standards consist of sections of the same uniform transmission-line with different lengths

Reference nanomaterials to improve the reliability of nanoscale measurements

March 1, 2017
Author(s)
Gert Roebben, Vincent A. Hackley, Hendrik Emons
Reference materials are essential tools to assure the quality of measurement results, from R&D labs to production facilities. They help increase the reliability of measurements, as laboratories can use reference materials to verify, for themselves, and

Standardizing CT Lung Density Measure Across Scanner Manufacturers

March 1, 2017
Author(s)
Huaiyu H. Chen-Mayer, Matthew Fuld, Bernice Hoppel, Phillip Judy, Junfeng Guo, David Lynch, Antonio M. Possolo, Sean B. Fain
Computed Tomography imaging of the lung, reported in Hounsfield Units (HU), can be parameterized as a quantitative image biomarker for the diagnosis and monitoring of lung density changes due to emphysema, a type of chronic obstructive pulmonary disease

Characterization of a PXIe based low-field digital NMR spectrometer

February 25, 2017
Author(s)
Joshua R. Biller, Karl F. Stupic, Anthony B. Kos, Timothy Weilert, George Rinard, Yoshi Nakashima, John M. Moreland
A low-field nuclear magnetic resonance (NMR) instrument is an important tool for investigating a wide variety of samples under different conditions. In this paper, we describe a system constructed primarily with commercially available hardware and control

Comparison between angularly and spectrally resolved gloss measurements with gloss measurements carried out on a national reference goniometer for gloss calibration

February 22, 2017
Author(s)
Andree R. Charriere, Maria E. Nadal, Clarence Zarobila
The present work consists in developing a procedure which will allow to compare gloss values obtained from an angularly and spectrally resolved Bidirectional Reflectance Distribution Function (BRDF) measurement and gloss values measured with a national

Establishing a World-Wide Unified Rockwell Hardness Scale Using Standard Diamond Indenters

February 19, 2017
Author(s)
S Desogus, A Germak, H Ishida, T Polzin, H Yang, Jun-Feng Song, Samuel Low, David J. Pitchure
Recently developed microform measurement techniques have reduced the measurement uncertainties in the geometry of Rockwell diamond indenters. It is now possible to establish standard grade Rockwell diamond indenters characterized by high geometry

Imaging Optics and CCD Camera Characterization for Metrology

February 19, 2017
Author(s)
S Fox, Edward A. Kornegay, Richard M. Silver
Optical semiconductor characterization and metrology rely heavily on digital camera imaging and its associated optical imaging systems. This work characterizes the performance of a widely used, commercially available camera and compares its performance to

LTE impacts on GPS

February 15, 2017
Author(s)
William F. Young, Ari D. Feldman, Sheryl M. Genco, Azizollah Kord, Daniel G. Kuester, John M. Ladbury, Duncan A. McGillivray, Audrey K. Puls, Andre R. Rosete, Adam J. Wunderlich, Wen-Bin Yang
This report describes the test methodology from “LTE impacts on GPS: Test and Metrology Plan” developed by National Advanced Spectrum and Communications Test Network (NASCTN), and data that are the result of executing the test method. The fundamental goals

Noise characteristics of thermistors: measurement methods and results of selected devices

February 13, 2017
Author(s)
Ivan Ryger, Michelle S. Stephens, Malcolm G. White, Nathan A. Tomlin, Matthew T. Spidell, John H. Lehman, Dave Harber
As part of the development of a spectrally-uniform room-temperature absolute radiometer, we have studied the electrical noise of several bulk chip thermistors in order to estimate the noise floor and optical dynamic range. Understanding the fundamental

Enabling photoemission electron microscopy in liquids via graphene-capped microchannel arrays

February 8, 2017
Author(s)
Hongxuan Guo, Evgheni Strelcov, Alexander Yulaev, Jian Wang, Narayana Appathurai, Stephen Urquhart, John Vinson, Subin Sahu, Michael P. Zwolak, Andrei Kolmakov
Photoelectron emission microscopy (PEEM) is a powerful tool to spectroscopically access dynamic surface processes at the nanoscale but is traditionally limited to ultra-high or moderate vacuum conditions. Here, we develop a novel graphene-capped

Final report on the key comparison, CCM.PK15 in the pressure rangefrom 1.0 x 10-4 Pa to 1.0 Pa

January 30, 2017
Author(s)
Christian Wuethrich, Hitoshi Akimichi, Mercede Bergoglio, James A. Fedchak, Karl Jousten, Sueng Soo Hong, Jorge T. Guzman
The comparison CCM.M.P-K14 is a key comparison in pressure involving six laboratories in three regional metrological organizations (RMO). The measurand of the comparison is the accommodation coefficient of two spinning rotating gauge characterized in

From Image Tiles to Web-Based Interactive Measurements in One Stop

January 4, 2017
Author(s)
Antoine Vandecreme, Michael P. Majurski, Joe Chalfoun, Keana Scott, John Henry Scott, Mary C. Brady, Peter Bajcsy
This article aims at introducing readers to a web-based solution useful for interactive measurements of centimeter-sized specimens at nanoscales. Modern imaging technology has enabled nanoscale imaging to become a routine process. As the imaging technology

Gas-phase broadband spectroscopy using active sources: progress, status, and applications

January 1, 2017
Author(s)
Kevin C. Cossel, Eleanor M. Waxman, Ian A. Finneran, Geoffery A. Blake, Jun Ye, Nathan R. Newbury
Broadband spectroscopy is an invaluable tool for measuring multiple gas-phase species simultaneously. In this work we review current applications for broad-band spectroscopy. We discuss components of broad-band spectroscopy including light sources

Automation of Piston Gauge Calibration Services Phase I Results

December 29, 2016
Author(s)
Katie M. Schlatter, Julia Scherschligt, John S. Quintavalle, Robert G. Driver, Christina D. Cross
This report documents efforts to date to automate Piston Gage Calibration Services. This report includes an overview of the project, results for Phase I Implementation efforts, and a look ahead to Phase II. Phase I Measures and Deliverables are based on

Spectral dependence of carrier lifetimes in silicon for photovoltaic applications

December 21, 2016
Author(s)
John F. Roller, Yu-Tai Li, Mario Dagenais, Behrang H. Hamadani
Charge carrier lifetimes in photovoltaic-grade silicon wafers were measured by a spectral-dependent, quasi-steady-state photoconductance technique. Narrow bandwidth LEDs were used to excite excess charge carriers within the material, and the effective

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

December 19, 2016
Author(s)
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

Introduction to the special issue on small-angle scattering

December 19, 2016
Author(s)
Michael Gradzielski, Andrew J. Allen
This is the foreword for a Special Issue of the Journal of Applied Crystallography on Small-Angle Scattering. This special issue collects together full-length peer-reviewed research papers in association with the 15th International Conference on Small
Displaying 451 - 475 of 2605