13,149 research outputs found
Aquila X--1: a low inclination soft X-ray transient
We have obtained I-band photometry of the neutron star X-ray transient Aql
X--1 during quiescence. We find a periodicity at 2.487 cd-1, which we interpret
as twice the orbital frequency (19.30+/-0.05 h). Folding the data on the
orbital period, we model the light curve variations as the ellipsoidal
modulation of the secondary star. We determine the binary inclination to be
20--31 degrees (90 per cent confidence) and also 95 per cent upper limits to
the radial velocity semi-amplitude and rotational broadening of the secondary
star to be 117 kms-1 and 50 kms-1 respectively.Comment: 4 pages text, 3 figures, to appear in MNRA
Low-Frequency Quantum Oscillations due to Strong Electron Correlations
The normal-state energy spectrum of the two-dimensional - model in a
homogeneous perpendicular magnetic field is investigated. The density of states
at the Fermi level as a function of the inverse magnetic field
reveals oscillations in the range of hole concentrations . The
oscillations have both high- and low-frequency components. The former
components are connected with large Fermi surfaces, while the latter with van
Hove singularities in the Landau subbands, which traverse the Fermi level with
changing . The singularities are related to bending the Landau subbands due
to strong electron correlations. Frequencies of these components are of the
same order of magnitude as quantum oscillation frequencies observed in
underdoped cuprates.Comment: 10 pages, 3 figures, Proc. NSS-2013, Yalta. arXiv admin note: text
overlap with arXiv:1308.056
Planned Closeout of the Cf-252 Loan/Lease Program
New funding is sought to pursue planned closeout of the Cf-252 Loan Program. The work will be performed in phases. In the initial phase, users will be surveyed to determine whether they wish to take ownership of sources in their possession, or return them. In the second phase, sources will be recalled from non-DOE entities, and source ownership transfers will be performed. In the third phase, the remaining sources from DOE entities will be recalled. Initial funding of $350K is sought to fund the first phase, and to plan execution of the remaining phases given information collected from user surveys
High accuracy measure of atomic polarizability in an optical lattice clock
Despite being a canonical example of quantum mechanical perturbation theory,
as well as one of the earliest observed spectroscopic shifts, the Stark effect
contributes the largest source of uncertainty in a modern optical atomic clock
through blackbody radiation. By employing an ultracold, trapped atomic ensemble
and high stability optical clock, we characterize the quadratic Stark effect
with unprecedented precision. We report the ytterbium optical clock's
sensitivity to electric fields (such as blackbody radiation) as the
differential static polarizability of the ground and excited clock levels:
36.2612(7) kHz (kV/cm)^{-2}. The clock's fractional uncertainty due to room
temperature blackbody radiation is reduced an order of magnitude to 3 \times
10^{-17}.Comment: 5 pages, 3 figures, 2 table
Investigation and study of a multi-aperture antenna system final report, 1 jan. - 1 apr. 1964
Multiple aperture adaptive antenna system for telemetry reception from remote space vehicle
Evidence for ammonium-bearing minerals in Ceres
Evidence for ammonium-bearing minerals was found on the surface of the largest asteroid Ceres. The presence of ammonium-bearing clays suggests that Ceres has experienced a period of alteration by substantial amounts of an ammonium-bearing fluid. The presence of the ammonium-bearing clays does not preclude Ceres maintaining a volatile inventory in the core or in a volatile-rich zone at some distance below the surface. Telescopic observations of Ceres, using the 3.0 meter NASA Infrared telescope facility prompted this reevaluation of its surface mineralogy
New Talent Signals: Shiny New Objects or a Brave New World?
Almost 20 years after McKinsey introduced the idea of a war for talent, technology is disrupting the talent identification industry. From smartphone profiling apps to workplace big data, the digital revolution has produced a wide range of new tools for making quick and cheap inferences about human potential and predicting future work performance. However, academic industrial–organizational (I-O) psychologists appear to be mostly spectators. Indeed, there is little scientific research on innovative assessment methods, leaving human resources (HR) practitioners with no credible evidence to evaluate the utility of such tools. To this end, this article provides an overview of new talent identification tools, using traditional workplace assessment methods as the organizing framework for classifying and evaluating new tools, which are largely technologically enhanced versions of traditional methods. We highlight some opportunities and challenges for I-O psychology practitioners interested in exploring and improving these innovations
Forages for Horses
According to the 1997 Census of Agriculture, Ohio had 11,668 horse farms. An OSU survey estimated nearly 250,000 horses in Ohio. The large number of horses in the state has prompted many questions from producers to Extension personnel on the topic of improving forage resources. While many horse producers are proficient at equine management, they have not had formal training in forage production and management. Often, traditional agronomic programs don\u27t target this audience. Many horse producers do not have the land mass, and/or experience to utilise large mechanical equipment for renovation and managemen
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