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Displaying 10976 - 11000 of 74014

Tissue Distribution of Perfluoroalkyl Acids (PFAAs) and Health Status in Wild Mozambique Tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa

November 29, 2017
Author(s)
Jacqueline T. Bangma, Jessica L. Reiner, Hannes Botha, Theresa M. Cantu, Marco Gouws, Matthew P. Guillette, Jeremy P. Koelmel, Wilmien Luus-Powell, Olivia Rynders, Joseph Sara, Willem J. Smit, John Bowden
This study collected male Mozambique tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa in 2014 and 2016 to investigate the levels of 15 perfluoroalkyl acids (PFAAs) across six tilapia tissues. Nine of the 15 PFAAs were detected

Ultra-high contrast coherent population trapping resonances in a cold-atom microwave clock

November 29, 2017
Author(s)
Xiaochi Liu, V. I. Yudin, A. V. Taichenachev, John Kitching, Elizabeth Donley
A cold-atom coherent population trapping clock can achieve a better long-term frequency stability than similar clocks based on vapor cells, since long interrogation periods are possible without introducing systematic frequency shifts from buffer gases

Characterization of Transmission Lines with Nonlinear Dielectric Materials

November 28, 2017
Author(s)
Aaron M. Hagerstrom, Christian J. Long, Nathan D. Orloff, James C. Booth, Eric J. Marksz
Nonlinear transmission lines are interesting for two broad reasons: first, they have several direct device applications (i.e. harmonic generation, and phase shifters), and second, they provide a way to characterize nonlinear materials at mm-wave

Contributions of precision engineering to the revision of the SI

November 28, 2017
Author(s)
Stephan Schlamminger, Harald Bosse, Horst Kunzmann, Jon R. Pratt, Ian Robinson, Michael de Podesta, Paul Shore, Paul Morantz
All measurements performed in science and industry are based on the International System of Units, the SI. It has been proposed to revise the SI following an approach which had already been implemented for the redefinition of the unit of length, the metre

Establishing Traceability for SOLT Calibration Kits*

November 28, 2017
Author(s)
Ronald A. Ginley
Establishing traceability for a measurement is very important so that the results of the measurement can be used in a common framework for comparisons and understanding. The standard source of traceability for Short-Open-Load-Thru (SOLT) calibrations has

Free Surface Relaxations of Star-Shaped Polymer Films

November 28, 2017
Author(s)
Alexandros Chremos, Bradley R. Frieberg, Emmanouil Glynos, Kyle Johnson, Hengxi Yang, Suresh Narayanan, Peter F. Green, Georgios Sakellariou
X-ray photon correlation spectroscopy (XPCS) studies show that the viscosities of thin film linear chain polymers at temperatures sufficiently high above the bulk glass transition temperature Tg bulk are equal to the bulk zero shear viscosities. The free

Helical Level Structure of Dirac Potential Wells

November 28, 2017
Author(s)
Daniel T. Walkup, Joseph A. Stroscio
In graphene and other massless 2D Dirac materials, Klein tunneling compromises electron confinement, and momentum-space contours can be assigned a Berry phase which is either zero or π. Consequently, in such systems the energy spectrum of circular

Multimodality of Structural, Electrical, and Gravimetric Responses of Intercalated MXenes to Water

November 28, 2017
Author(s)
Eric S. Muckley, Michael Naguib, Hsiu-Wen Wang, Lukas Vlcek, Naresh C. Osti, Robert L. Sacci, Xiahan Sang, Raymond R. Unocic, Yu Xie, Madhu Sudan Tyagi, Eugene Mamontov, Katharine L. Page, Paul R. C. Kent, Jagjit Nanda, Ilia N. Ivanov
Understanding of structural, electrical and gravimetric peculiarities of water vapor interaction with ion-intercalated MXenes used to design of a multimodal humidity sensor. Neutron scattering coupled to molecular dynamics and ab initio calculations showed

Probing the dielectric response of the interfacial buffer layer in epitaxial graphene via optical spectroscopy

November 28, 2017
Author(s)
Heather M. Hill, Albert Rigosi, Sugata Chowdhury, Yanfei Yang, Nhan Van Nguyen, Francesca Tavazza, Randolph Elmquist, David B. Newell, Angela R. Hight Walker
Monolayer epitaxial graphene (EG) is a suitable candidate for a variety of electronic applications. One advantage of EG growth on the Si face of SiC is that it develops as a single crystal, as does the layer below, referred to as the interfacial buffer

Protecting Controlled Unclassified Information in Nonfederal Information Systems and Organizations [including updates as of 11-28-2017]

November 28, 2017
Author(s)
Ronald S. Ross, Patrick Viscuso, Gary Guissanie, Kelley L. Dempsey, Mark Riddle
[Superseded by SP 800-171 Rev. 1 (December 2016, updated 02/20/2018): https://doi.org/10.6028/NIST.SP.800-171r1] The protection of Controlled Unclassified Information (CUI) while residing in nonfederal information systems and organizations is of paramount

Rydberg Atom Electric-Field Metrology

November 28, 2017
Author(s)
Joshua A. Gordon, Christopher L. Holloway, Matthew T. Simons
We present a technique which shows great promise for realizing an atomic standard measurement of RF fields that is intrinsically calibrated, directly linked to the SI and atomic structural constants. This technique relies on the reponse of Rydberg atoms to

Guidance on the TDEA Block Ciphers

November 27, 2017
Author(s)
Elaine B. Barker, Larry Feldman, Gregory A. Witte
This bulletin summarizes the information found in NIST SP 800-67, Rev. 2, Recommendation for the Triple Data Encryption Algorithm (TDEA) Block Cipher. This bulletin offers an overview of the TDEA block cipher along with usage guidance and NIST’s plans.

Kicking the Tires of the NIST Microwave Uncertainty Framework Part 2*

November 27, 2017
Author(s)
Ronald A. Ginley
Traceability of a measurement requires two parts. An unbroken chain of measurements and uncertainties for each link of the chain. The NIST Microwave Uncertainty Framework (MUF) can provide both the required parts for a single link in the chain or for

Neutron and X-ray Tomography (NeXT) system for simultaneous, dual modality tomography

November 27, 2017
Author(s)
Jacob M. LaManna, Daniel S. Hussey, Elias M. Baltic, David L. Jacobson
Dual mode tomography offers the potential of improved estimation of the composition of a sample from the complimentary of the interaction of the two probes with the sample. We have developed a simultaneous neutron and 90 keV X-ray tomography system that is

Plasma nanotexturing of silicon surfaces for photovoltaics applications: Influence of initial surface finish on the evolution of topographical and optical properties

November 27, 2017
Author(s)
Guillaume Fischer, Etienne Drahi, Martin Foldyna, Thomas Germer, Erik V. Johnson
Using a plasma to generate a surface texture with feature sizes on the order of nanometers ("nanotexturing") is a promising technique being considered for application in thin, high- efficiency crystalline silicon solar cells. This study investigates the

Pressure Tuning of Collapse of Helimagnetic Structure in Au 2 Mn

November 27, 2017
Author(s)
I Lin NMN Liu, Maria J. Pascale, Juscelino Leao, Craig Brown, William D. Ratcliff, Qingzhen Huang, Nicholas Butch
We identify the phase boundary between spiral spin and ferromagnetic phases in Au 2Mn at a critical pressure of 16.4 kbar, as determined by neutron diffraction, magnetization and magnetoresistance measurements. The temperature-dependent critical field at a

The 2017 IARPA Face Recognition Prize Challenge (FRPC)

November 27, 2017
Author(s)
Patrick J. Grother, Mei L. Ngan, Lars Ericson, Kayee K. Hanaoka, Christopher Boehnen
This report documents NIST’s execution of the Intelligence Advanced Research Projects Activity (IARPA) Face Recognition Prize Challenge 2017. The (FRPC) was conducted to assess the capability of contemporary face recognition algorithms to recognize faces

Towards a Hybrid Human-Computer Scientific Information Extraction Pipeline

November 27, 2017
Author(s)
Roselyne B. Tchoua, Kyle Chard, Debra Audus, Logan T. Ward, Lequieu Joshua, Juan J. de Pablo, Ian Foster
The emerging field of materials informatics has the potential to greatly reduce time-to-market and development costs for new materials. The success of such efforts hinges on access to large, high-quality databases of material properties. However, many such

Two-Dimensional Strain-Mapping by Electron Backscatter Diffraction and Confocal Raman Spectroscopy

November 27, 2017
Author(s)
Andrew J. Gayle, Lawrence Henry Friedman, Ryan Beams, Brian G. Bush, Yvonne B. Gerbig, Chris A. Michaels, Mark D. Vaudin, Robert F. Cook
The strain field surrounding a spherical indentation in silicon is mapped in two dimensions (2- D) using electron backscatter diffraction (EBSD) cross-correlation and confocal Raman spectroscopy techniques. The 200 mN indentation created a 4 m diameter
Displaying 10976 - 11000 of 74014