U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 18101 - 18125 of 74079

Radiowave Propagation in Urban Environments with Application to Public-Safety Communications

August 4, 2014
Author(s)
William F. Young, Catherine A. Remley, Christopher L. Holloway, Galen H. Koepke, Dennis G. Camell, John M. Ladbury, Colton R. Dunlap
We characterize key elements that pose challenges to public-safety radio communications into and out of large buildings, including the strong attenuation of radio signals caused by losses and scattering in the building materials and structure, and the

Ignition of Mulch Beds Exposed to Continuous-Wind Driven Firebrand Showers

August 3, 2014
Author(s)
Samuel L. Manzello, Sayaka Suzuki, Koji Kagiya, Junichi Suzuki, Yoshihiko Hayashi
A series of experiments were conducted to examine ignition of mulch beds to continuous, wind-driven firebrand showers. Shredded hardwood mulch, fitted in beds 1.2 m by 1.2 m with a thickness of 51 mm, was attached to a non-combustible re-entrant corner

A Measurement Metric for Forensic Latent Fingerprint Preprocessing

August 1, 2014
Author(s)
Haiying Guan, Andrew Dienstfrey, Mary Theofanos, Brian Stanton
Although fingerprint mark-up and identification are well-studied fields, forensic fingerprint image preprocessing is still a relatively new domain in need of further scientific study and development of guidance of best practice. Latent fingerprint image

Construction of a watt balance with the aim to realize the kilogram at the National Institute of Standards and Technology

August 1, 2014
Author(s)
Darine El Haddad, Leon Chao, Frank Seifert, David B. Newell, Jon R. Pratt, Stephan Schlamminger
A redefinition of the International System of Units, the SI, is impending and could occur as early as 2017. After redefinition a means to realize the unit of mass is required. A watt balance is a promising device to realize the unit of mass at the kilogram

Crosstalk Corrections for Coplanar-Waveguide Scattering-Parameter Calibrations

August 1, 2014
Author(s)
Dylan F. Williams, Franz-Josef Schmuckle, Ralf Doerner, Phung N. Gia, Uwe Arz, Wolfgang Heinrich
We study crosstalk and crosstalk corrections in coplanar waveguide vector-network-analyzer calibrations. We show that while crosstalk corrections can improve measurement accuracy, the effectiveness of the corrections depends on a number of factors

Design and Testing of a Mobile Touchscreen Interface for Multi-Modal Biometric Capture

August 1, 2014
Author(s)
Kristen Greene, Ross J. Micheals, Kayee K. Hanaoka, Gregory P. Fiumara
In this report, we describe in detail the design and usability testing of a touchscreen interface for multimodal biometric capture, an application called WSABI, Web Services for the Acquisition of Biometric Information. The application code is publicly

Development of an EUVL collector with infrared radiation suppression

August 1, 2014
Author(s)
Steven E. Grantham, Mike Kriese, Yuriy Platonov, Bodo Ehlers, Licai Jiang, Jim Rodriguez, Mueller Ulrich, Shayna khatri, Adam Magruder, Charles S. Tarrio
Laser-produced plasma (LPP) sources for extreme ultraviolet lithography (EUVL) systems utilize CO2 lasers operating with wavelength 10.6μm. Since multilayer-coated optics have high reflectivity for this infrared radiation (IR), a significant and

Development of Low Carrier Density Graphene Devices

August 1, 2014
Author(s)
Yanfei Yang, Lung-I Huang, David B. Newell, Yasuhiro Fukuyama, Mariano A. Real, Randolph Elmquist
Epitaxial graphene on SiC(0001) is used to fabricate Hall bar structures for metrological applications with a fabrication process that has been developed to eliminate organic chemical contamination of the graphene. Before any lithographic patterning a

Elliptic Curves arising from Brahmagupta Quadrilaterals

August 1, 2014
Author(s)
Farzali Izadi, Foad Khoshnam, Dustin Moody, Arman Zargar
A Brahmagupta quadrilateral is a cyclic quadrilateral whose sides, diagonals, and area are all integer values. In this article, we characterize the notions of Brahmagupta, introduced by K. R. S. Sastry, by means of elliptic curves. Motivated by these

Improved measurement capabilities at the NIST EUV Reflectometry Facility

August 1, 2014
Author(s)
Charles S. Tarrio, Steven E. Grantham, Thomas A. Germer, Jack C. Rife, Thomas B. Lucatorto, Mike Kriese, Yuriy Platonov, Licai Jiang, Jim Rodriguez
The NIST Extreme Ultraviolet (EUV) Reflectometry Facility was designed in the 1990s to accommodate the largest multilayer optics envisioned at that time. However, with increasing power requirements for an EUV scanner, source collection optics have grown

In Search of Better Pressure Standards

August 1, 2014
Author(s)
Jay H. Hendricks, Jacob E. Ricker, Patrick F. Egan, Gregory F. Strouse
Based on highly accurate optical interferometry and fundamental quantum calculations, researchers at the National Institute of Standards and Technology (NIST) in the US are developing an improved definition of the SI unit for pressure that will consign the

Incorporating Biometric Software Development Kits into the Development Process

August 1, 2014
Author(s)
Karen Marshall, Ross J. Micheals, Kevin C. Mangold, Kayee K. Hanaoka
Biometric devices have emerged as pervasive and indispensable tools in facilitating security in many industries and governments worldwide�. The use of these devices has consistently increased and advanced. However, advancement of the methodologies used to

International comparison of measurements of hard magnets with the Vibrating Sample Magnetometer

August 1, 2014
Author(s)
F. Fiorillo, C. Beatrice, D. Son, Franz Josef Ahlers, R. Groessinger, F. Albertini, Y. P. Liu, A Lin, E. Patroi, Robert D. Shull, O. Thomas
We present the results of an international comparison regarding the magnetic properties of hard magnets, measured using the Vibrating Sample Magnetometer. The comparison involved eight different international laboratories, plus two laboratories using the

Nanoscale Imaging and Spectroscopy of Plasmonic Modes with the PTIR technique

August 1, 2014
Author(s)
Aaron M. Katzenmeyer, Jungseok Chae, Richard Kasica, Glenn Holland, Basudev Lahiri, Andrea Centrone
The collective oscillation of conduction electrons in plasmonic nanomaterials allows the coupling of propagating light waves with nanoscale volumes of matter ("hot spots") and allows engineering their optical response from the UV to THz as a function of

Phase Transitions and Magnetocaloric Effect in Mn 3 Cu 0.89N d0.96^

August 1, 2014
Author(s)
Jun Yan, Ying Sun, Hui Wu, Qingzhen Huang, Cong Wang, Zaixing Shi, Sihao Deng, Kewen Shi, Huiqing Lu, Lihua Chu
We report the large magnetic entropy change observed in the antiperovskite Mn 3Cu 0.89N 0.96. Based in the heat flow peak measured by differential scanning calorimeter (DSC), the total entropy change according to the structural transition (tetragonal to
Displaying 18101 - 18125 of 74079