NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 36101 - 36125 of 73697

Component-Level Demonstration of a Microfabricated Atomic Frequency Reference

August 29, 2005
Author(s)
Vladislav Gerginov, Svenja A. Knappe, P Schwindt, V Shah, Li-Anne Liew, John Moreland, Hugh Robinson, Leo W. Hollberg, John E. Kitching, Alan Brannon, J Breitbarth, Z Popovic
We demonstrate component-level functionality of the three critical subsystems for a chip-scale atomic clock: the physics package, the local oscillator and the control electronics. In addition, we demonstrate that these three components functioning together

Evaluation of Pressure Oscillator Losses

August 29, 2005
Author(s)
Peter E. Bradley, Michael A. Lewis, Ray Radebaugh
Efficiencies of regenerative cryocoolers are influenced by losses within the pressure oscillator (compressor). An evaluation of these losses is important when searching for ways to improve the overall cryocooler efficiency. Typically, compressor efficiency

GerberTranslator: Moving towards new PCB standards

August 29, 2005
Author(s)
Matthew L. Aronoff, John V. Messina
This paper describes the key features of the NIST-developed software tool called ?GerberTranslator?. GerberTranslator is a software translator which automates the majority of the work in converting a printed circuit board (PCB) described in the industry

Impedance Measurements of Inertance Tubes

August 29, 2005
Author(s)
Michael A. Lewis, Peter E. Bradley, Ray Radebaugh
The flow impedance of an inertance tube 5.74 mm inside diameter and 2.36 m long coupled to various reservoir volumes was measured and compared with that predicted by a model based on a transmission line analogy. Though data at other average pressures and

Laser cooling and launching performance in a (1,1,1) -geometry atomic fountain

August 29, 2005
Author(s)
Elizabeth A. Donley, Thomas P. Heavner, John O'Brien, Steven R. Jefferts, F Levi
We have successfully cooled and launched cesium atoms in the (1,1,1) atomic fountain geometry at temperatures as low as 0.8 mK. This corresponds to a mean thermal velocity of 0.7 cm/s, which is two times the photon recoil velocity of 0.35 cm/s. Factors

Noise Properties of Microwave Signals Synthesized with Femtosecond Lasers

August 29, 2005
Author(s)
Eugene N. Ivanov, John J. McFerran, Scott A. Diddams, Leo W. Hollberg
We discuss various aspects of high resolution phase noise measurements at microwave frequencies. This includes methods to achieve thermal noise limited sensitivity and improved immunity to amplitude fluctuations of microwave signals. A few prototype

On the Power Dependence of Extraneous Microwave Fields in Atomic Frequency Standards

August 29, 2005
Author(s)
Steven R. Jefferts, Jon H. Shirley, Neil Ashby, Thomas P. Heavner, Elizabeth A. Donley, F Levi
We show that the frequency bias caused by distributed cavity phase has a strong dependence on microwave power. We also show that frequency biases associated with microwave leakage have distinct signatures in their dependence on microwave power and the

Sources of Instabilities in Two-Way Time Transfer

August 29, 2005
Author(s)
Thomas E. Parker, Victor S. Zhang
Two-Way Satellite Time and Frequency Transfer (TWSTFT) has become an important component in the international system for comparing time and frequency over long distances. In order to make further improvements in the stability of TWSTFT a more complete

The Inter-American Metrology System (SIM) Common-View GPS Comparison Network

August 29, 2005
Author(s)
Michael A. Lombardi, Andrew N. Novick, Jose M. Lopez, Jean-Simon Boulanger, Raymond Pelletier
The Inter-American Metrology System (SIM) consists of national metrology institutes in 34 member nations located throughout North, Central, and South America. Currently, at least ten SIM laboratories pursue time and frequency metrology, and are responsible

W-band dual channel AM/PM noise measurement system - an update

August 29, 2005
Author(s)
Archita Hati, Craig Nelson, J Nava, David A. Howe, Fred L. Walls, Huascar Ascarrunz, Justin Lanfranchi, Bill Riddle
We discuss the performance of a W-band (92-96) GHz amplitude modulated (AM) and phase modulated (PM) noise measurement system. The system uses two nearly identical channels to measure the residual noise in amplifiers in pulsed mode with a duty cycle of 10%

Combinatorial Synthesis and Dissolution Testing of Polyanhydride Copolymers

August 28, 2005
Author(s)
Brandon M. Vogel, Naomi Eidelman, Surya Mallapragada, Balaji Narasimhan
A linearly varying compositional library of 100 different polyanhydride randomcopolymers was designed, fabricated, and characterized within a few hours. A subset of this library was chosen and a substrate was designed and fabricated to enable the synthesis

Microfluidic Platform for Combinatorial Measurements of Polymer Particles

August 28, 2005
Author(s)
Zuzanna T. Cygan, Susan E. Barnes, Kathryn L. Beers, Eric J. Amis
Organic-stable microfluidic devices are used for combinatorial measurements of polymerization reactions on chip. Formulation, processing, and measurement are combined on one chip device for the generation of combinatorial polymer libraries. A monomer /

Spectroscopic Monitoring of Polymerization in Microfluidic Channels

August 28, 2005
Author(s)
Susan E. Barnes, Anthony J. Bur, Zuzanna T. Cygan, Kathryn Beers, Eric J. Amis
At NIST Combinatorial Methods Center (NCMC) we are interested in the construction of material libraries that explore a range of polymer chemistries and properties. In this study we extend on-chip application of spectroscopic techniques to the analysis of

Characterization of Optical Traps Using On-Line Estimation Methods

August 26, 2005
Author(s)
Jason J. Gorman, Thomas W. LeBrun, et al
System identification methods are presented for the estimation of the characteristic frequency of an optically trapped particle. These methods are more amenable to automated on-line measurements and are believed to be less prone to erroneous results

Uncertainties in Scaling Factors for Ab Intio Vibrational Frequencies

August 26, 2005
Author(s)
K Irikura, R Johnson, Raghu N. Kacker
The n-qubit concurrence canonical decomposition (CCD) is a generalization of the two-qubit canonical decomposition SU(4)=[SU(2) (x) SU(2)] ? [SU(2) (x) SU(2)], where ? is the commutative group which phases the maximally entangled Bell basis. A prequel

A Microstructure Fiber Two Photon Source With Conjugate Laser Pumps

August 25, 2005
Author(s)
Jingyun Fan, Alan L. Migdall, L Wang
We present a systematic experimental study of generating correlated photon pairs using a reversed degenerate four-wave mixing process. By overlapping a pair of parallel- (or cross-) polarized laser pump pulses at conjugate frequencies in a microstructure

Investigation of 3D Tyrosine-Derived Polycarbonate Scaffold for Tissue Engineering

August 25, 2005
Author(s)
J S. Stephens, Tithi Dutta Roy, Joy P. Dunkers, Aarti Rege, J Kohn
A library of tyrosine-derived polycarbonates of have been developed that share a structurally identical backbone with a rich chemical and structural diversity, which depend solely on the pendent ester substituent (Scheme 1).1 The physical and chemical

Progress Toward the Second-Generation Atomic Fountain Clock at NIST

August 23, 2005
Author(s)
Elizabeth Donley, M O. Tataw, F Levi, Steven R. Jefferts, Thomas P. Heavner
We present results on the performance of two important subsystems for NIST -F2 -the second-generation atomic fountain clock at NIST. Firstly, we demonstrate the efficient capture of cesium atoms from a low-velocity intense source (LVIS) of atoms into an
Displaying 36101 - 36125 of 73697
Was this page helpful?