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NIST Authors in Bold

Displaying 24251 - 24275 of 73726

Frequency-stabilization to 6x10 -16 via spectral-hole burning

September 11, 2011
Author(s)
Michael J. Thorpe, Tara M. Fortier, Matthew S. Kirchner, Till P. Rosenband, Lars Rippe
We demonstrate two-stage laser stabilization based on a combination of Fabry-Pérot and spectral-hole burning techniques. The laser is first pre-stabilized by the Fabry-Pérot cavity to a fractional-frequency stability of ς y(τ) -13. A pattern of spectral

A Field Study of User Behavior and Perception in Smartcard Authentication

September 9, 2011
Author(s)
Emile L. Morse, Celeste L. Paul, Aiping L. Zhang, Yee-Yin Choong, Mary F. Theofanos
A field study of 24 participants over 10 weeks explored user behavior and perception in a smartcard authentication system. Ethnographic methods used to collect data included diaries, surveys, interviews, and field observations. We observed a number of

Defining AFIS Latent Print "Lights-Out"

September 8, 2011
Author(s)
Stephen Meagher, Vladimir N. Dvornychenko
The term "lights-out" for AFIS ten-print fingerprint operations has been around for many years and is generally understood to mean "no human intervention is involved." But is this term appropriate for AFIS latent print operations? This IR examines seven

Effect of AlN Buffer Layer Properties on the Morphology and Polarity of GaN Nanowires Grown by Molecular Beam Epitaxy

September 8, 2011
Author(s)
Matthew D. Brubaker, Kristine A. Bertness, Norman A. Sanford, Albert Davydov, Igor Levin, Devin M. Rourke, Victor M. Bright
Low temperature AlN buffer layers grown by plasma-assisted Molecular Beam Epitaxy (MBE) on Si (111) were found to significantly affect the subsequent growth morphology of GaN nanowires. The AlN buffer layers exhibited nanowire-like columnar protrusions

Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis - 2011

September 8, 2011
Author(s)
Amy S. Rushing, Joshua D. Kneifel, Barbara C. Lippiatt
This is the 2011 edition of energy price indices and discount factors for performing life-cycle cost analyses of energy and water conservation and renewable energy projects in federal facilities. It will be effective from April 1, 2011 to March 31, 2012

Near-ground-state transport of trapped-ion qubits through a multidimensional array

September 8, 2011
Author(s)
Dietrich G. Leibfried, Rodney B. Blakestad, Christian Ospelkaus, Aaron Vandevender, Janus Wesenberg, Michael J. Biercuk, David J. Wineland
We have demonstrated transport of 9Be+ ions through a 2D Paul-trap X-junction array while maintaining the ions near the motional ground-state of their local potential well. We expand on the first report of the experiment in [1], including a detailed

NIST Cloud Computing Reference Architecture

September 8, 2011
Author(s)
Fang Liu, Jin Tong, Jian Mao, Robert B. Bohn, John V. Messina, Mark L. Badger, Dawn M. Leaf
The adoption of cloud computing into the Federal Government and its implementation depend upon a variety of technical and non-technical factors. A fundamental reference point, based on the NIST definition of Cloud Computing, is needed to describe an

Extension of ThermoML: The IUPAC Standard for Thermodynamic Data Communications (IUPAC Recommendations 2011)

September 7, 2011
Author(s)
Michael D. Frenkel, Robert D. Chirico, Vladimir Diky, Paul L. Brown, John H. Dymond, Robert N. Goldberg, Anthony R. Goodwin, Heiko Heerklotz, Erich Koenigsberger, John E. Ladbury, Kenneth N. Marsh, David P. Remeta, Stephen E. Stein, William A. Wakeham, Peter A. Williams
ThermoML is an XML-based approach for storage and exchange of experimental, predicted, and critically evaluated thermophysical and thermochemical property data. Extensions to the ThermoML schema for the representation of speciation, complex equilibria, and

Pulse Terahertz Reflection/Scattering Measurement

September 7, 2011
Author(s)
Shu Z. Lo, Edwin J. Heilweil
We report a method to measure reflection and scattering from several samples with different degrees of surface roughness and material properties at terahertz frequencies. Reflection from a flat gold mirror shows that the full width half maximum (FWHM) of

Are Electron Tweezers Possible?

September 6, 2011
Author(s)
Vladimir P. Oleshko, James M. Howe
Positively answering the question above, we demonstrate in this work single electron beam trapping and steering of 20-100 nm solid Al nanoparticles generated inside opaque submicron-sized molten Al-Si eutectic alloy spheres. Imaging of solid nanoparticles

State Discriminiation Signal Nulling Receivers

September 6, 2011
Author(s)
Francisco E. Becerra Chavez, Jingyun Fan, Gerald Baumgartner, Sergey V. Polyakov, Julius Goldhar, Jonathan Kosloski, Alan L. Migdall
Optimized state-discrimination receiver strategies for nonorthogonal states can improve the capacity of the communication channels operating with error rates below the ones corresponding to conventional receivers. Coherent signal-nulling receivers use a

User's Guide for SRM 2494 and 2495: The MEMS 5-in-1, 2011 Edition

September 6, 2011
Author(s)
Janet M. Cassard, Jon C. Geist, Theodore V. Vorburger, David T. Read, David G. Seiler
The Microelectromechanical Systems (MEMS) 5-in-1 is a standard reference device sold as a NIST Standard Reference Material (SRM) that contains MEMS test structures on a test chip. The two SRM chips (2494 and 2495) provide for both dimensional and material

Measuring agglomerate size distribution and dependence of localized surface plasmon resonance absorbance on gold nanoparticle agglomerate size using analytical ultracentrifugation

September 3, 2011
Author(s)
Justin M. Zook, Vinayak Rastogi, Robert I. MacCuspie, Athena M. Keene, Jeffrey A. Fagan
Nanoparticles frequently agglomerate when dispersed into relevant biological and environmental media, with the resulting change to the effective size distribution dramatically affecting the potential nanotoxicity and the absorbance for biosensor

Absence of Long-Range Ordering in the Pyrochlore Compound Er 2 Sn 2 O 7

September 2, 2011
Author(s)
P. M. Sarte, H. J. Silverstein, B. T. K. Van Wyk, Jason S. Gardner, Yiming Qiu, H. D. Zhou, C. R. Wiebe
The low temperature behavior of powder Er 2Sn 2O 7 samples has been studied by magnetic susceptibility, heat capacity, and neutron scattering experiments. We report here the presence of no magnetic ordering down to 100 mK. Anomalies in the heat capacity

Control of magnetic fluctuations by spin current

September 2, 2011
Author(s)
Vladislav E. Demidov, Sergei Urazhdin, Eric Edwards, Mark D. Stiles, Robert McMichael, Sergej O. Demokritov
We utilize micro-focus Brillouin light scattering spectroscopy to study the interaction of spin current generated by the spin Hall effect with magnetic fluctuations in a Permalloy microdisc. We show that the fluctuations can be efficiently enhanced or

p-Wave Cold Collisions in an Optical Lattice Clock

September 2, 2011
Author(s)
Nathan D. Lemke, Andrew D. Ludlow, J. von Stecher, Jeffrey A. Sherman, A.M. Rey, Christopher W. Oates
State-of-the-art optical clocks with neutral atoms employ an optical lattice to tightly confine the atoms, enabling high-resolution spectroscopy and the potential for high-accuracy timekeeping. Interrogating many atoms simultaneously facilitates high

An Interlaboratory Stopwatch Comparison in the SIM Region

September 1, 2011
Author(s)
Michael A. Lombardi, Raul Solis, Harold Sanchez, J. Mauricio Lopez-Romero, Francisco Jimenez, Henry Postigo, Daniel Perez, Walter Adad, Victor Masi, Ahmed Ibrahim, Bill Hoger, Ricardo de Carvalho, Jose L. Kronenberg, Gustavo C. Orozco, Theodore Reddock, Leonardo Trigo
Stopwatches and timers are used for an almost unlimited number of applications and are among the most common devices calibrated by metrology laboratories. In large nations, stopwatch calibrations are typically handled by secondary laboratories, such as

Atomic Sensors - A Review

September 1, 2011
Author(s)
John E. Kitching, Svenja A. Knappe, Elizabeth A. Donley
We discuss the basic physics and instrumentation issues related to high performance physical and inertial sensors based on atomic spectroscopy.

Cost-Efficient Routing with Controlled Node Mobility in Sensor Networks

September 1, 2011
Author(s)
Kamran Sayrafian
In this paper, an energy-efficient strategy is proposed for tracking a moving target in a mobile sensor network. The energy expenditure of the sensors in the network is assumed to be due to communication, sensing and movement. First, the target area is

Experimental characterization and crystal plasticity finite element modeling of heterogeneous deformation in commercial purity titanium

September 1, 2011
Author(s)
Y Yang, L. Wang, C. Zambaldi, P. Eisenlohr, R. Barabash, W. Liu, Mark R. Stoudt, M. A. Crimp, T. R. Bieler
Heterogeneous deformation, including local dislocation shear activity and lattice rotation, was analyzed in microstructure patches of polycrystalline, commercial purity titanium specimens using three different experimental methods. Crystal plasticity
Displaying 24251 - 24275 of 73726
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