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NIST Authors in Bold

Displaying 22626 - 22650 of 74100

A High-Resolution Atlas of Uranium-Neon in the H Band

February 3, 2012
Author(s)
Scott A. Diddams, Stephen L. Redman, Gabriel G. Ycas, Ryan Terrien, Suvrath Mahadevan, Lawrence W. Ramsey, Chad F. Bender, Steve Osterman, Franklyn J. Quinlan, James E. Lawler, Gillian Nave
The rapid advance in near-infrared (NIR) detector technology in the past decade has lead to a number of high-resolution astronomical spectrometers that are either in operation or in the planning stages. Precision wavelength calibration techniques

Annual Report to Sponsor: Understanding Unwanted Combustion Enhancement by Potential Halon Replacements

February 3, 2012
Author(s)
Gregory T. Linteris, Jeffrey A. Manion, Donald R. Burgess Jr., Iftikhar A. Awan, Peter B. Sunderland, John L. Pagliaro
This year, we continued work to numerically model the behavior of the Halon replacements in the FAA Aerosol Can Test (FAA-ACT) to understand why they are causing more overpressure rather than flame extinction. The goal is to understand the process to

Nanoscale structure measurements for polymer-fullerene photovoltaics

February 3, 2012
Author(s)
Dean M. DeLongchamp, Regis J. Kline, Andrew A. Herzing
This review covers methods to measure key aspects of nanoscale structure in organic photovoltaic devices based on polymer-fullerene bulk heterojunctions. The importance of nanoscale structure to the power conversion efficiency and stability of these

Antibacterial amorphous calcium phosphate nanocomposite with quaternary ammonium salt and silver nanoparticles

February 2, 2012
Author(s)
Nancy J. Lin, Lei Cheng, Michael D. Weir, Hockin H. Xu, Joseph M. Antonucci, Alison M. Kraigsley, Sheng Lin-Gibson, Xuedong Zhou
Objectives. Calcium and phosphate ion-releasing resin composites are promising for remineralization; however, so far there has been no report on imparting a potent antibacterial capability to these composites. The objectives of this study were to

Control of Molecular Mass Distributions in Enzymatic Lactone Polymerizations

February 2, 2012
Author(s)
Santanu S. Kundu, Peter M. Johnson, Kathryn L. Beers
Using a model developed for the enzyme catalyzed polymerization and degradation of poly(caprolactone), we illustrate methods and the kinetic mechanisms necessary to improve molecular mass distributions by manipulating equilibrium reactions in the kinetic

Double-Focusing Thermal Triple-Axis Spectrometer at the NCNR

February 2, 2012
Author(s)
Y. Chen, Sung Chang, Yang Zhao, Songxue Chi, William D. Ratcliff, B. G. Ueland, Ross Erwin
The new thermal triple-axis spectrometer at the NIST Center for Neutron Research (NCNR) is located at the BT-7 beam port. The 165 mm diameter reactor beam is equipped with a selection of Söller collimators, beam-limiters, and pyrolytic graphite (PG) filter

NIST Ionization Chamber "A" Sample-Height Corrections

February 2, 2012
Author(s)
Ryan P. Fitzgerald
For over 30 years scientists in the NIST radioactivity group have been using their ionization chamber “A” to make measurements of radioactivity and radioactive half-lives. We now have evidence that some of those reported measurements were incorrect due to

Standardization of Broadband UV Measurements for 365 nm LED Sources

February 2, 2012
Author(s)
George P. Eppeldauer
Broadband UV measurements are analyzed when UV-A irradiance meters measure optical radiation from 365-nm sources. The CIE standardized rectangular-shape UV-A function can be realized only with large spectral mismatch errors. The spectral power-distribution

A statistical study of de-embedding applied to eye diagram analysis

February 1, 2012
Author(s)
Paul D. Hale, Jeffrey A. Jargon, Chih-Ming Wang, Brett Grossman, Matthew Claudius, Jose Torres, Andrew M. Dienstfrey, Dylan F. Williams
We describe a stable method for calibrating digital waveforms and eye diagrams using the measurement system response function and its regularized inverse. The function describing the system response includes the response of the oscilloscope and any

Absolute measurements of x-ray backlighter sources at energies above 10 keVa)

February 1, 2012
Author(s)
Lawrence T. Hudson, B.R. Maddox, H.S. Parks, B A. Remington, C. Chen, S Chen, S. T. Prisbrey, A. Comley, C A. Back, C. Szabo, John F. Seely, Uri Feldman, Stephen M. Seltzer, M. J. Haugh, Z. Ali
Line emission and broadband x-ray sources with x-ray energies above 10 keV have been investigated using a range of calibrated x-ray detectors for use as x-ray backlighters in high energy density (HED) experiments. The conversion efficiency of short- and

Building Security into Off-the-Shelf Smartphones

February 1, 2012
Author(s)
Angelos Stavrou, Jeff Voas, Tom T. Karygiannis, Stephen Quirolgico
Recent advancements in hardware have increased the computing power, memory, storage, and wireless connectivity of handheld mobile devices. Smart-phone devices are used for everyday activities that range from Maps and Geo-location tagging to banking. Indeed

Dispersion-Strengthened Silver Alumina for Sheathing Bi2Sr2CaCu2O8+x Multifilamentary Wire

February 1, 2012
Author(s)
Amir Kajbafvala, William Nachtrab, Xifeng Lu, Frank Hunte, Xiaotao Liu, Najib Cheggour, Terence Wong, Justin Schwartz
High strength, high modulus dispersion strengthened (DS) silver-aluminum alloys are studied for sheathing Bi 2Sr 2CaCu 2O8 +x (Bi2212) round wire. Dispersion strengthening is an effective method for producing a fine grain metallurgical structure that is

Hyperspectral Imaging of Ischemic Wounds

February 1, 2012
Author(s)
David W. Allen
Optical imaging has the potential to achieve high spatial resolution and high functional sensitivity in wound assessment. However, clinical acceptance of many optical imaging devices is hampered by poor reproducibility, low accuracy, and lack of biological

Molecular Insights into a-Synuclein and Its N-terminal Peptides at the Membrane Interface

February 1, 2012
Author(s)
Candace M. Pfefferkorn, Frank Heinrich, Alexander J. Sodt, Alexander S. Malstev, Richard W. Pastor, Jennifer C. Lee
The role of phospholipids in modulating α-synuclein (α-syn) conformation is of great interest because α-syn aggregation is linked to Parkinson¿s disease. Using a sparsely tethered-bilayer composed of 1:1 molar ratio of 1-palmitoyl-2-oleoyl-sn-glycero-3

Numerical Study of the Thermodynamics of Clinoatacamite

February 1, 2012
Author(s)
Ehsan Khatami, Joel Helton, Marcos Rigol
In this Brief Report, we discuss the use of linked-cluster expansions in solving quantum models that break certain symmetries of the underlying lattice. We sketch the algorithm for the numerical linked-cluster expansions (NLCEs) and show that although some
Displaying 22626 - 22650 of 74100