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Search Publications

NIST Authors in Bold

Displaying 22651 - 22675 of 73697

Application of Internal Curing for Mixtures Containing High Volumes of Fly Ash

August 1, 2012
Author(s)
Igor de la Varga, Javier Castro, Dale P. Bentz, Jason Weiss
Sustainability has become an important issue in the concrete industry in recent years. One way to make concrete more sustainable is through the replacement of portland cement clinker with alternative cementitious materials such as fly ash. While fly ash is

Combustion Properties of Halogenated Fire Suppressants

August 1, 2012
Author(s)
Gregory T. Linteris, Valeri I. Babushok, Oliver Meier
Previous experimental studies have shown that some halogenated fire suppressant agents added to hydrocarbon-air systems can enhance the combustion. For example, their addition to the air stream can widen the flammability limits of lean mixtures, and

Comparison of JP-8 and JP-8+100 with the Advanced Distillation Curve Approach

August 1, 2012
Author(s)
Thomas J. Bruno, Kathryn R. Abel, Jennifer Riggs
Additive packages are used with aviation kerosenes to achieve performance enhancements such as higher or lower operating temperatures or increased lubricity. An additive used to increase operating temperatures for heat sink applications is the +100

Does Your SEM Really Tell the Truth?

August 1, 2012
Author(s)
Michael T. Postek, Andras Vladar
The scanning electron microscope (SEM) has gone through a tremendous evolution to become a critical tool for many, diverse scientific and industrial applications. The high resolution of the SEM is especially useful for qualitative and quantitative

Laser power meter comparison at far infrared wavelengths and terahertz frequencies

August 1, 2012
Author(s)
John H. Lehman, Marla L. Dowell, Nina P. Basta, Kerry N. Betz, Erich N. Grossman
We have evaluated the responsivity of seven different detectors compared to an electrically calibrated photo-acoustic detector at 119 υm (2.5 THz) and 394 υm (0.76 THz) laser wavelengths. Among the detectors is an electrically calibrated thermopile having

Legendre Fit to the Reflection Coefficient of a Radiating Rectangular Waveguide Aperture

August 1, 2012
Author(s)
Dylan F. Williams, Mohammad T. Ghasr, Bradley K. Alpert, Zhongxiang Shen, Alexander Arsenovic, Robert M. Weikle, Reza Zoughi
We accurately calculate the reflection coefficient and normalized admittance of radiating open-ended rectangular waveguides and fit our results with a linear combination of Legendre polynomials. We verify the expression to an accuracy of 0.005 with other

Microscopic Insights into Ion Gel Dynamics using Neutron Spectroscopy

August 1, 2012
Author(s)
Maiko Kofu, Takenori Someya, Soichi Tatsumi, Kazuhide Ueno, Takeshi Ueki, Masayoshi Watanabe, Takuro Matsunaga, Mitsuhiro Shibayama, Victoria Garcia Sakai, Madhu Sudan Tyagi, Osamu Yamamuro
We have investigated the microscopic dynamics of ion gels consisting of a PMMA [poly(methyl methacrylate)] network and EMITSFI [1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide] as the ionic liquid, by means of quasi-elastic neutron

Mid-infrared virtually imaged phased array spectrometer for rapid and broadband trace gas detection

August 1, 2012
Author(s)
Lora L. Nugent-Glandorf, Tyler W. Neely, Florian B. Adler, Adam J. Fleisher, Kevin C. Cossel, Bryce Bjork, Tim P. Dinneen, Chris S. Wood, Jun Ye, Scott A. Diddams
We present and analyze a 2-D imaging spectrometer based on a virtually imaged phased array (VIPA) disperser for rapid, high-resolution molecular detection using mid-infrared (MIR) frequency combs. A broad bandwidth, MIR laser source centered at ~3.1 υm

Sensing Trace Amounts of Nitro-Aromatic Explosives using Nanowire-Nanocluster Hybrids

August 1, 2012
Author(s)
Geetha G. Aluri, Abhishek Motayed, Albert Davydov, Vladimir P. Oleshko, Kristine A. Bertness, Norman A. Sanford
The threat of terrorism and the need for homeland security calls for advanced technologies to detect the concealed explosives safely and efficiently. We demonstrated highly sensitive and selective detection of traces of nitro-aromatic explosive compounds

Using Viscosity Modifiers to Reduce Effective Diffusivity in Mortars

August 1, 2012
Author(s)
Kenneth A. Snyder, Dale P. Bentz, Jeffrey M. Davis
Three viscosity modifiers (a commercial shrinkage-reducing admixture, a polypropylene glycol, and cellulose ether) are used to reduce the effective diffusivity of chloride ions through mortars during a one-year exposure. Two delivery mechanisms were

A Literature Review of the Effects of Fire Smoke on Electrical Equipment

July 31, 2012
Author(s)
Richard D. Peacock, Thomas G. Cleary, Paul A. Reneke, Daniel Murphy
A review is presented of the state of the art of smoke production measurement, prediction of smoke impact as part of computer-based fire modeling, and measurement and prediction of the impact of smoke through deposition of soot on and corrosion of

Calibration uncertainty for the NIST PM/AM noise standards

July 31, 2012
Author(s)
Archita Hati, Craig W. Nelson, Neil Ashby, David A. Howe
NIST provides an on-site calibration service of the accuracy of phase modulation (PM) noise, amplitude modulation (AM) noise and noise floor of the measurement systems at a customer's site using one or more portable PM/AM secondary noise standards. In this

Efficient Methods for Interoperability Testing Using Event Sequences

July 31, 2012
Author(s)
David R. Kuhn, James M. Higdon, J .M. Lawrence, Raghu N. Kacker, Yu Lei
Many software testing problems involve sequences of events. The methods described in this paper were motivated by testing needs of mission critical systems that may accept multiple communication or sensor inputs and generate output to several communication
Displaying 22651 - 22675 of 73697
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