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NIST Authors in Bold

Displaying 13176 - 13200 of 74137

Trapped-ion optical atomic clocks at the quantum limits

January 31, 2017
Author(s)
David R. Leibrandt, Samuel M. Brewer, Jwo-Sy Chen, Aaron M. Hankin, David B. Hume, David J. Wineland, Chin-Wen Chou
Frequency and its inverse, time, are the most accurately measured quantities. Historically, improvements in the accuracy of clocks have enabled advances in navigation, communication, and science. Since 1967, the definition of the SI second has been based

Tuning flexibility to control selectivity in soft porous crystals

January 31, 2017
Author(s)
Nathan Mahynski, Vincent K. Shen
We use flat-histogram Monte Carlo simulations to study how changing the flexibility of soft porous crystals (SPCs) affects their selective adsorption of a binary, size-asymmetric supercritical fluid. Specifically, we consider mesoporous SPCs which have

2015 Location-Based Services R&D Summit Report

January 30, 2017
Author(s)
Harris Feldman, Adam H. Danielson
The Public Safety Communications Research Program (PSCR) convened over 80 stakeholders at the National Institute of Standards and Technology (NIST) Boulder, CO campus to build on the findings presented in the 2015 Location-Based Services (LBS) Summit- held

2016 PSCR Analytics Summit Report

January 30, 2017
Author(s)
Jeremy E. Benson, Harris Feldman
PSCR hosted over 80 stakeholders from industry, academia, public safety, and government to the NIST Boulder campus in August 2016. The August summit was a follow-up to the Public Safety Analytics R&D Roadmap, published earlier in 2016. This document

Band Alignment Measurement by Internal Photoemission Spectroscopy

January 30, 2017
Author(s)
Nhan V. Nguyen
parameters affecting the performance of advanced electronic and optoelectronic devices. Among the common band offset measurement techniques, internal photoemission has been proven to be a novel method which is almost a direct measurement without

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

Industrial Wireless Systems: Radio Propagation Measurements

January 30, 2017
Author(s)
Richard Candell, Catherine A. Remley, Jeanne T. Quimby, David R. Novotny, Alexandra Curtin, Peter B. Papazian, Galen H. Koepke, Joseph Diener, Mohamed T. Hany
Radio frequency (RF) propagation measurements were conducted at three facilities representing a cross-section of different classes of industrial environments. Selected sites included a multi-acre transmission assembly factory typical of the automotive

Insights into Cruciform Sample Design

January 30, 2017
Author(s)
Adam A. Creuziger, Mark A. Iadicola, Timothy J. Foecke, Evan Rust, Dilip K. Banerjee
Four different cruciform sample designs, based on the work of Abu-Farha et al, were studied in this paper. The original design of Abu-Farha was validated at room temperature for a thicker sample, and two modified sample geometries that would permit thinner

THE USE AND CHALLENGES OF PRECISE TIME IN ELECTRIC POWER SYNCHROPHASOR SYSTEMS

January 30, 2017
Author(s)
Marc A. Weiss, Alison Silverstein, Francis Tuffner, Ya-Shian Li-Baboud
Today, the principal way that power system owners and operators use precision timing is for fault recording, protection system operation and in synchrophasor applications. Synchrophasor applications have among the most stringent precision time and time

An Overview of Mobile Application Vetting Services for Public Safety

January 27, 2017
Author(s)
Gema E. Howell, Michael A. Ogata
The Middle Class Tax Relief Act of 2012 mandated the creation of the Nation's first nationwide, high-speed communications network dedicated for public safety. The law instantiated a new federal entity, the Federal Responder Network Authority (FirstNet), to

Fabrication of Scanning Electrochemical Microscopy-Atomic Force Microscopy (SECM-AFM) Probes to Image Surface Topography and Reactivity at the Nanoscale

January 27, 2017
Author(s)
Jeyavel Velmurugan, Amit K. Agrawal, Sang M. An, Eric A. Choudhary, Veronika A. Szalai
Electrocatalysts, used in energy applications, rely on the solid-liquid interface to carry out productive chemistry. This interface is generally less amenable to standard surface-science characterization methods, making the investigation of the surface

Increasing evidence indicates low bioaccumulation of carbon nanotubes

January 27, 2017
Author(s)
Rhema Bjorkland, David Tobias, Elijah Petersen
As the production of carbon nanotubes (CNTs) expands, so does the potential for release into the environment. The possibility of bioaccumulation and toxicological effects has prompted research on their fate and potential ecological effects. For many

Uncertainty Assessment of Equations of State Applied to Organic Rankine Cycles

January 27, 2017
Author(s)
Ian H. Bell, Kenneth G. Kroenlein, John P. O'Connell, Jens Abildskov, Jerome Frutiger, Gurkan Sin
This study presents a generic method to analyze and select equations of state (EoS) based on detailed uncertainty analysis of the respective EoS property parameters. A Cubic EoS (i.e. Soave-Redlich-Kwong SRK) is compared to PC-SAFT EoS. The uncertainty

Homogenization Kinetics of a Nickel-based Superalloy Produced by Powder Bed Fusion Laser Sintering

January 26, 2017
Author(s)
Fan Zhang, Lyle E. Levine, Andrew J. Allen, Eric Lass, Sudha Cheruvathur, Mark R. Stoudt, Maureen E. Williams, Yaakov S. Idell, Carelyn E. Campbell
Additively manufactured (AM) metal components often exhibit fine dendritic microstructures and elemental segregation due to the initial rapid solidification and subsequent melting and cooling during the build process, which without homogenization would

Measuring and Improving the Effectiveness of Defense-in-Depth Postures

January 26, 2017
Author(s)
Peter M. Mell, James Shook, Richard Harang
Defense-in-depth is an important security architecture principle that has significant application to industrial control systems (ICS), cloud services, storehouses of sensitive data, and many other areas. We claim that an ideal defense-in-depth posture is

Spatial variation in perfluoroalkyl acids in a population of wild American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR) surrounding the Kennedy Space Center (KSC)

January 26, 2017
Author(s)
John Bowden, Jacqueline T. Bangma, Martin Jones, Russell H. Lowers, Frances Nilsen, Jessica L. Reiner, Thomas R. Rainwater, Stephen E. Somerville, Louis J. Guillette Jr.
This study aimed to quantify fourteen perfluoroalkyl acids (PFAAs) in the plasma of a population of alligators located at Merritt Island national Wildlife Refuge (MINWR). Male (n = 117) and female (n = 112) alligators were sampled in every month during

A New Generation of Magnetoencephalography: Room Temperature Measurements using Optically-Pumped Magnetometers

January 25, 2017
Author(s)
Elena Boto, Sofie S. Meyer, Vishal Shah, Orang Alem, Svenja A. Knappe, Peter Kruger, Mark Fromhold, Peter G. Morris, Richard W. Bowtell, Gareth R. Barnes, Matthew J. Brookes, Mark Lim
Significant advances in the field of quantum sensing mean that magnetic field detectors, operating at room temperature, are now able to achieve sensitivity similar to that of cryogenically cooled devices (SQUIDs). This means that room temperature

Beyond IRBs: Designing Ethical Review Processes for Big Data Research

January 25, 2017
Author(s)
Simson L. Garfinkel
Big Data Research is something new, a practice rooted in large-scale data collection that frequently combines aspects of research, experimentation, and entertainment. Yet another mismatch between the worlds of Big Data research and IRB system are the

Compact 2.2 K Cooling System for Superconducting Nanowire Single Photon Detectors

January 25, 2017
Author(s)
Vincent Y. Kotsubo, Ray Radebaugh, Sae Woo Nam, Joel N. Ullom, Brandon L. Wilson, Paul Hendershott, Micheal Bonczyski
We are developing a compact, low power, closed cycle cooling system for Superconducting Nanowire Single Photon Detectors. The base temperature of the present prototype, which uses a helium-4 Joule-Thomson stage, is 2.2 K with over 1.2 mW of cooling. This
Displaying 13176 - 13200 of 74137