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Displaying 18276 - 18300 of 74061

A nonlinearity in permanent-magnet systems used in watt balances

June 25, 2014
Author(s)
Shisong Li, Stephan Schlamminger, Jon R. Pratt
In watt balances that employ permanent magnet systems to generate the magnetic flux the effects of the weighing current on the magnet systems can generate a systematic bias that can lead to an error in the result if not accounted for. In this article a

Interrelationship between Number of Mobile Protons, Diffusion Coefficient, and AC Conductivity in Superprotonic Conductors, CsHSO 4 and Rb 3 H(SeO 4 ) 2

June 25, 2014
Author(s)
Kazuya Kamazawa, Masashi Harada, Toru Araki, Yasumitsu Matsuo, Madhu Sudan Tyagi, Jun Sugiyama
Using quasielastic neutron scattering (QENS), we investigated proton dynamics for two superprotonic conductors, CsHSO 4 and Rb 2H(SeO 4) 2. In the superprotonic conducting phase, two translational proton motions were observed for the both compounds. Making

SRM Spotlight July 2014

June 25, 2014
Author(s)
Regina R. Montgomery
The SRM Spotlight is a newsletter published by the Office of Reference Materials for users of NIST standard reference materials. The Spotlight announces new reference materials and provides information about their use. In addition, this newsletter contains

Vapor Phase Metal-Assisted Chemical Etching of Silicon

June 25, 2014
Author(s)
Owen J. Hildreth, Daniel R. Schmidt
This work introduces and explores vapor phase metal‐assisted chemical etching (VP‐MaCE) of silicon as a method to bypass some of the challenges found in traditional liquid phase metal‐assisted chemical etching (LP‐MaCE). Average etch rates for Ag, Au, and

LDPC Error Correction for Gb/s QKD

June 24, 2014
Author(s)
Alan Mink, Anastase Nakassis
Low Density Parity Check (LDPC) error correction is a one-way algorithm that has become popular for quantum key distribution (QKD) post-processing. Graphic processing units (GPUs) provide an interesting attached platform that may deliver Gb/s error

Modelling the vertical UL 94 test: Competition and collaboration between melt dripping, gasification and combustion

June 24, 2014
Author(s)
Florian Kempel, Bernhard Schartel, Julio M. Marti, Kathryn Butler, Riccardo Rossi, Sergio R. Idelsohn, Anja Hofmann
An experimental and numerical investigation of the impact of the additives bisphenol A bis(diphenyl phosphate) (BDP) and polytetrafluoroethylene (PTFE) on the fire behaviour of bisphenol A polycarbonate / acrylonitrile butadiene styrene (PC/ABS) in the

Measuring Freeze and Thaw Damage in Mortars Containing Deicing Salt Using a Low Temperature Longitudinal Guarded Comparative Calorimeter and Acoustic Emission (AE-LGCC)

June 23, 2014
Author(s)
Yaghoob Farnam, Dale P. Bentz, Aaron R. Sakulich, Daniel R. Flynn, Jason Weiss
Deicing salts are often applied to the surface of pavements and bridge decks in the winter to melt ice; thereby improving safety for the travelling public. In this paper, the influence of NaCl deicing salt on freezing and thawing temperatures of pore

A Cognitive-Behavioral Framework of User Password Management Lifecycle

June 22, 2014
Author(s)
Yee-Yin Choong
Passwords are the most commonly used mechanism in controlling users’ access to information systems. Little research has been established on the entire user password management lifecycle from the start of generating a password, maintaining the password

Character Strings, Memory and Passwords: What a Recall Study Can Tell Us.

June 22, 2014
Author(s)
Brian C. Stanton, Kristen Greene
Many users must authenticate to multiple systems and applications, often using different passwords, on a daily basis. At the same time, the recommendations of security experts are driving increases in the required character length and complexity of

Development of a Scale to Assess the Linguistic and Phonological Difficulty of Passwords

June 22, 2014
Author(s)
Jennifer R. Bergstrom, Stefan A. Frisch, David C. Hawkins, Joy Hackenbracht, Kristen K. Greene, Mary Theofanos, Brian Griepentrog
Increasingly, institutions are requiring or recommending that their employees use secure, system-generated passwords. It is not clear how well linguistic and phonological language properties map onto complex, randomly-generated passwords. Passwords

I Can't Type That! P@$$w0rd Entry on Mobile Devices

June 22, 2014
Author(s)
Kristen Greene, Melissa A. Gallagher, Brian C. Stanton, Paul Y. Lee
Given the numerous constraints of onscreen keyboards, such as smaller keys and lack of tactile feedback, remembering and typing long, complex passwords — an already burdensome task on desktop computing systems —becomes nearly unbearable on small mobile

The Decline in Reported Smoking-Caused Wildfires

June 21, 2014
Author(s)
David T. Butry, Jeffrey P. Prestemon, Douglas S. Thomas
The number of smoking-caused wildfires has been falling nationwide. On national forests in 2011, smoking-caused wildfires represented only 10 % of their 1980 level. No other cause of wildfire has experienced this level of decline. Using U.S. Forest Service

Computational Modeling and Validation of Aerosol Deposition in Ventilation Ducts

June 20, 2014
Author(s)
Kristopher J. Overholt, Jason Floyd, Ofodike A. Ezekoye
In fire models, the accurate prediction of aerosol/soot concentrations in the gas phase and aerosol/soot deposition thicknesses in the condensed phase is important for a wide range of applications, including human egress calculations, heat transfer in

Figure metrology for x-ray focusing mirrors with Fresnel holograms and photon sieves

June 20, 2014
Author(s)
Ulf Griesmann, Johannes A. Soons, Quandou (. Wang, Lahsen Assoufid
We report on interferometric measurements of the figure error of an ultra-precise mirror with the shape of an elliptical toroid for the diffraction limited focusing of hard x-rays from an undulator x-ray source. We describe measurement configurations using
Displaying 18276 - 18300 of 74061