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Displaying 1426 - 1450 of 2503

On the 209Po Half-Life Error and Its Confirmation: A Critique

June 11, 2015
Author(s)
Ronald Colle, Arthur M. Colle
Collé, et al [(2007) Appl. Radiat Isot. 65, 728; (2014) J. Phys. G: Nucl. Part. Phys. 41, 105103], over the course of nearly a decade and with decay data from a period of 20.7 years, initially uncovered and then substantiated a 25 % error in the 209Po half

Recent measurements of the gravitational constant as a function of time

June 11, 2015
Author(s)
Stephan Schlamminger, Jens H. Gundlach, Riley D. Newman
A recent publication (J.D. Anderson et. Al., EPL 110, 1002) found a strong correlation between the measured values of the gravitational constant G and the 5.9-year oscillation of the length of day. Here, we provide a compilation of all published

Gas Chromatographic Retention Indices

June 9, 2015
Author(s)
Thomas J. Bruno
The interpretation of results from chromatographic measurements can often be augmented with an appropriate mathematical treatment of the solute retention that is observed. The goal of treatment is to make the resulting metric as independent of the

Suppression of Spin Pumping between Ni80Fe20 and Cu by a Graphene Interlayer

June 7, 2015
Author(s)
William J. Gannett, Mark W. Keller, Hans Nembach, Thomas J. Silva, Ann Chiaramonti Debay
Abstract We compare ferromagnetic resonance measurements of Py (Ni80Fe20) films sputtered onto Cu(111) with and without a graphene (Gr) interlayer grown by chemical vapor deposition before Py deposition. We find the expected damping enhancement from spin

Tunable Spin Qubit Coupling Mediated by a Multi-Electron Quantum Dot

June 4, 2015
Author(s)
Vanita Srinivasa, Haitan Xu, Jacob M. Taylor
We present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multi-electron, two-level quantum dot. The effective exchange interaction mediated by the dot can be understood as the simplest

Fetal magnetocardiography measurements with a multichannel microfabricated atomic magnetometer array

June 3, 2015
Author(s)
Svenja A. Knappe, Orang Alem, Tilmann H. Sander, Rahul R. Mhaskar, John LeBlanc, Hari Eswaran, Uwe Steinhoff, Yoshio Okada, John E. Kitching, Lutz Trahms
Following the rapid progress in the development of atomic magnetometer technology for the measurement of magnetic fields in the femtotesla range, a successful assembly of individual sensors into an array of nearly identical sensors is within reach. The

Progress on the Optical Lattice Clock

June 1, 2015
Author(s)
Andrew D. Ludlow, Jun Ye
We summarize recent research in the development of the optical lattice clock, with particular focus on the ytterbium and strontium lattice clocks being developed at NIST and JILA. We highlight recent progress in improving the stability and uncertainty of

A Miniature EBIT with Ion Extraction for Isolating Highly Charged Ions

May 28, 2015
Author(s)
Shannon Hoogerheide, Joseph Tan
We report on the development of a room-temperature miniature electron beam ion trap (EBIT) for efficient production of charge states with relatively low ionization energies. A unitary Penning trap is modified slightly to provide the magnetic field and

Spectrum and Energy Levels of Quadruply-Ionized Molybdenum (Mo V)

May 28, 2015
Author(s)
Joseph Reader, Tauheed Ahmad
The spectrum of quadruply-ionized molybdenum Mo V was observed from 200 Å to 4700 Å with sliding spark discharges on 10.7-m normal- and grazing-incidence spectrographs. The existing analyses of this spectrum [Tauheed A et al. 1985 Phys. Scr. 31 369; Cabeza

Spectral homogenization techniques for the hyperspectral image projector

May 15, 2015
Author(s)
Joseph P. Rice, Logan E. Hillberry
In an effort to improve technology for performance testing and calibration of multispectral and hyperspectral imagers, the National Institute of Standards and Technology (NIST) has been developing a Hyperspectral Image Projector (HIP) capable of projecting

New section of the HITRAN database: Collision-Induced Absorption (CIA)

May 14, 2015
Author(s)
Walter J. Lafferty
This paper describes the addition of Collision-Induced Absorption (CIA) into the HITRAN compilation. The data from different sources have been cast into a consistent format and formalism. The implementation of these new spectral data into the HITRAN

Revealing Integrated Intensity Distributions (RIID)

May 14, 2015
Author(s)
John F. Lesoine
Measuring the distribution of a light sources intensity fluctuations is important to many scientific disciplines. However, these integrated intensity distributions are hidden in noisy experimental photon counting data because of the photometric detection

SI-Traceable Calibrations of Celestial Objects

May 14, 2015
Author(s)
Keith R. Lykke, Claire E. Cramer, John T. Woodward IV
Photometric calibration is currently the leading source of systematic uncertainty in supernova surveys that aim to determine the nature of dark energy. The bulk of this uncertainty is due to imperfect knowledge of the spectral energy distribution of stars

Confronting the Complexity of Commercial Carbon Nanotube Materials

May 13, 2015
Author(s)
Luis Fernando Vargas Lara, Jack F. Douglas
The morphology of commercially available carbon nanotube materials is often much more complex than the term “carbon nanotube” (CNT) would imply. Commercial CNT materials are typically composed of roughly spherical CNT domains having a highly ramified

Mid-Infrared Optical Frequency Combs based on Difference Frequency Generation for Dual-Comb Spectroscopy

May 10, 2015
Author(s)
Flavio Caldas da Cruz, Daniel I. Maser, Todd Johnson, Gabriel G. Ycas, Andrew M. Klose, Fabrizio R. Giorgetta, Ian R. Coddington, Nathan R. Newbury, Scott A. Diddams
Mid-infrared femtosecond optical frequency combs at 2.8 - 3.5 υm were produced by difference frequency generation of the spectral components of a near-infrared comb in a 3-mm long MgO:PPLN crystal. We observe strong pump depletion and 9.3 dB parametric

A New Modem for Two Way Satellite Time and Frequency Transfer

April 13, 2015
Author(s)
Shengkang Zhang, Xueyun Wang, Haifeng Wang, Hongbo Wang, Yuan Yuan, Keming Feng
Two Way Satellite Time Frequency Transfer (TWSTFT) is a highly precise time & frequency remote comparison technique, which is widely used in time metrology, satellite navigation, etc. Nowadays, most of the time metrology laboratories in Europe, America and

Bias Corrections in Primary Frequency Standards

April 13, 2015
Author(s)
Steven R. Jefferts, F Levi
Corrections to Primary Frequency Standards (PFS) or Secondary Frequency Standards (SFS) for offsets caused by various physical phenomena, e.g. Zeeman shifts or Blackbody radiation shifts, are typically corrected using formulae that contain “known”

Bias Corrections in Primary Frequency Standards

April 13, 2015
Author(s)
Thomas E. Parker, Thomas P. Heavner, Steven R. Jefferts
Primary frequency standards serve the function of calibrating the rate of International Atomic Time, TAI, and therefore play a critical role in the accuracy of the world's time. The Working Group on Primary and Secondary Frequency Standards, WGPSFS, is an

Long-Term Uncertainty in Time Transfer Using GPS and TWTFT Techniques

April 13, 2015
Author(s)
Victor S. Zhang, Thomas E. Parker, Jian Yao
The techniques of GPS time and frequency transfer (code based and carrier phase) and two-way satellite time and frequency transfer (TWSTFT) are widely used in remote clock comparison and in the computation of International Atomic Time (TAI). Many timing
Displaying 1426 - 1450 of 2503
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