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NIST Authors in Bold

Displaying 18051 - 18075 of 74137

Policy Machine: Towards a General Purpose Enterprise-Wide Operating Environment

August 28, 2014
Author(s)
David F. Ferraiolo, Larry Feldman, Gregory A. Witte
The ability to control access to sensitive data in accordance with policy is perhaps the most fundamental security requirement. Despite over four decades of security research, the limited ability for existing access control mechanisms to enforce a

Proton Dynamics of Two-Dimensional Oxalate-Bridged Coordination Polymers

August 28, 2014
Author(s)
Satoshi Miyatsu, Maiko Kofu, Atsushi Nagoe, Takeshi Yamada, Masaaki Sadakiyo, Teppei Yamada, Hiroshi Kitagawa, Madhu Sudan Tyagi, Victoria Garcia Sakai, Osamu Yamamuro
A two-dimensional porous coordination polymer (NH 4) 2HOOC(CH 2) 4COOH}[ZN 2(Co 2O 4) 3] (abbreviated to ZnADP), which accommodates water molecules between the [Zn 2(C 2O 4) 3] layers, is highly remarked as a new-type crystalline proton conductor. In order

Structural characterization of Bi2Te3 and Sb2Te3 as a Function of Temperature Using Neutron Powder Diffraction (NPD) and Extended X-ray Absorption Fine Structure (EXAFS) Techniques

August 28, 2014
Author(s)
Winnie Wong-Ng, Azzam Mansour, Qingzhen Huang, Weihua Tang, Jeff Sharp, Alan Thompson
The structure of Bi2Te3 (Seebeck coefficient Standard Reference Material (SRM™ 3451)), and the related phase Sb2Te3 have been characterized as a function of temperature using the neutron powder diffraction (NPD) and the extended X-ray absorption fine

A review of NIST primary activity standards for 18F: 1982 to 2013

August 27, 2014
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Bert M. Coursey, Ryan P. Fitzgerald, Brian E. Zimmerman
The new NIST activity standardization for 18F differs from results obtained between 1998 and 2008 by 4 %. The new results are considered to be very reliable; they are based on a battery of robust primary measurement techniques and bring the NIST standard

July is National Ice Cream Month

August 27, 2014
Author(s)
Elizabeth J. Benham
A short article about ice cream and frozen novelties to appear in the Office of Weights and Measures newsletter, "Weights and Measures Connection." This document sites sections of the NIST Handbook 130, "Uniform Laws and Regulations in the Areas of Legal

Optimization of Focused Ion Beam-Tomography for Superconducting Electronics

August 27, 2014
Author(s)
Aric W. Sanders, Anna E. Fox, Paul D. Dresselhaus, Alexandra Curtin
Superconducting electronics play an important role in quantum computation, ultra-low power electronics, voltage standards and magnetic sensors. Many of these applications rely on the microfabrication of superconducting circuits with multiple wiring layers

Kilohertz Rotation of Nanorods Propelled by Ultrasound, Traced by Microvortex Advection of Nanoparticles

August 26, 2014
Author(s)
Andrew L. Balk, Lamar O. Mair, Pramod Mathai, Paul N. Patrone, Wei Wang, Suzanne Ahmed, Thomas Mallouk, James A. Liddle, Samuel M. Stavis
We measure the microvortical flows around gold nanorods propelled by ultrasound in water using polystyrene nanoparticles as optical tracers. We infer the rotational frequencies of such nanomotors assuming a hydrodynamic model of this interaction. In this

Multiscale Correlative Measurements of Nanoparticles in Cells

August 26, 2014
Author(s)
Aric W. Sanders, Kavita M. Jeerage, Cindi Schwartz, Alexandra E. Curtin, Ann C. Chiaramonti Debay
Nanoparticles are emerging as invaluable tools in disease diagnosis, disease treatment and imaging contrast enhancement agents. The interactions of nanoparticles with host organisms are complex and affect biological systems over length scales that vary

Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source

August 25, 2014
Author(s)
Uwe Arp, Alexander Sorokin, Ulf Jastrow, Pavle Jurani?, Svea Kreis, Mathias Richter, Yiping Feng, Dennis Nordlund, Kai Tiedtke, Philip Heimann, Bob Nagler, Hae Ja Lee, Stephanie Mack, Marco Cammarata, Oleg Krupin, Marc Messerschmidt, Michael Holmes , Michael Rowen, William Schlotter, Stefan Moeller, Joshua Turner
This paper reports novel measurements of x-ray optical radiation on an absolute scale from a recently developed source of radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the physics behind the

Milligram Mass Metrology Using Electrostatics

August 25, 2014
Author(s)
Gordon A. Shaw, John A. Kramar
— Although mass has historically been defined using an artifact standard, other means of realization are possible. One alternative approach employs a precision electromechanical balance, using the SI electrical units to derive a force used to measure the

Pseudomagnetic Fields in a Locally Strained Graphene Drumhead

August 25, 2014
Author(s)
Shuze Zhu, Yinjun Huang, Nikolai Klimov, David B. Newell, Nikolai Zhitenev, Joseph A. Stroscio, Santiago D. Solares Rivera, Teng Li
Recent experiments reveal that a scanning tunneling microscopy (STM) probe tip can generate a highly localized strain field in a graphene drumhead, which in turn leads to pseudomagnetic fields in the graphene that can spatially confine graphene charge

A 100 Tohm Guarded Hamon Transfer Standard

August 24, 2014
Author(s)
Dean G. Jarrett, Edward O'Brien, Marlin E. Kraft
Guarded Hamon transfer standards are used at NIST for scaling to high resistance levels. An improved design for a guarded Hamon transfer standard in the range from 1 TΩ to 100 TΩ is described. Measurements taken to select the primary and guard resistor

AC Waveform Source Referenced to a Programmable Josephson Voltage Standard

August 24, 2014
Author(s)
Alain Rufenacht, Charles J. Burroughs, Bryan C. Waltrip, Stephane P. Solve, Paul D. Dresselhaus, Samuel P. Benz
We are integrating an AC waveform source into our Programmable Josephson Voltage Standard system (PJVS). The objective is to provide a convenient, highly automated quantum-referenced source for ac voltage metrology that does not require the use of a

Accurate High-Ohmic Resistance Measurement Techniques up to 1 Pohm

August 24, 2014
Author(s)
Dean G. Jarrett, Gert Rietveld, Beat Jeckelmann
An overview is presented on precision high-ohmic resistance measurements for values of 100 Mohmand above. The two main measurement techniques in this resistance range are discussed, the current integration technique and the adapted Wheatstone bridge. The

Alignment and testing of the NIST Calculable Capacitor

August 24, 2014
Author(s)
Yicheng Wang, Felipe Guzman, Corey A. Stambaugh, Radek Smid, Hugo Zuniga Calvo, Andrew D. Koffman, Jon R. Pratt, John R. Lawall
This paper reports progress on the NIST effort to develop a new calculable capacitor, focusing on improvement of the guard electrode motion control as well as issues associated with the overall electrode alignment. Design of a multi-wavelength Fabry-Perot
Displaying 18051 - 18075 of 74137