43,602 research outputs found
Transonic wind-tunnel tests of an F-8 airplane model equipped with 12 and 14-percent thick oblique wings
An experimental investigation was conducted in the Ames 14-foot transonic wind tunnel to study the aerodynamic performance and stability characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing. Two elliptical planform (axis ratio = 8:1) wings, each having a maximum thickness of 12 and 14 percent, were tested. Longitudinal stability data were obtained with no wing and with each of the two wings set at sweep angles of 0, 45, and 60 deg. Lateral directional stability data were obtained for the 12 percent wing only. Test Mach numbers ranged from 0.6 to 1.2 in the unit Reynolds number range from 11.2 to 13.1 million per meter. Angles of attack were between -6 and 22 deg at zero sideslip. Angles of sideslip were between -6 and +6 deg for two angles of attack, depending upon the wing configuration
The 2MASS Tully-Fisher Survey : Mapping the Mass in the Universe
The 2MASS Tully-Fisher Survey (2MTF) aims to measure Tully-Fisher (TF)
distances for all bright inclined spirals in the 2MASS Redshift Survey (2MRS)
using high quality HI widths and 2MASS photometry. Compared with previous
peculiar velocity surveys, the 2MTF survey provides more accurate width
measurements and more uniform sky coverage, combining observations with the
Green Bank, Arecibo and Parkes telescopes. With this new redshift-independent
distance database, we will significantly improve our understanding of the mass
distribution in the local universe.Comment: 4 pages, 3 figures, IAU Symposium 289 proceedin
Critical review of the impacts of grazing intensity on soil organic carbon storage and other soil quality indicators in extensively managed grasslands
Acknowledgements This work contributes to the N-Circle project (grant number BB/N013484/1), and CINAg (BB/N013468/1) Virtual Joint Centres on Agricultural Nitrogen (funded by the Newton Fund via UK BBSRC/NERC), U-GRASS (grant number NE/M016900/1), the Belmont Forum/FACCE-JPI DEVIL project (grant number NE/M021327/1), Soils-R-GGREAT (grant number NE/P019455/1), ADVENT (grant number NE/M019713/1), SĂȘr Cymru LCEE-NRN project, Climate-Smart Grass and the Scottish Governmentâs Strategic Research Programme.Peer reviewedPublisher PD
Management and Labor Appraisals and Criticisms of the Arbitration Process: A Report with Comments
Although arbitration as a means of resolving disputes arising under collective bargaining agreements has received widespread acceptance in this country/ in recent years there has been some evidence of increasing criticism of the process. As part of a research project dealing with the impact of the 1960 Supreme Court decisions in the Warrior & Gulf trilogy and the 1962 Sinclair trilogy, we decided to ascertain how parties are appraising the arbitration process. We report here the more significant results of this survey along with our evaluation of the criticisms and suggestions which were received
The Supreme Court and Labor Dispute Arbitration: the Emerging Federal Law
Within the past few years, the United States Supreme Court has handed down a number of decisions of great significance to the labor dispute arbitration process. Some have been concerned with problems of arbitrability or arbitral authority; others with the availability and exclusivity of the arbitration process vis-a-vis alternative legal remedies for breach of the labor agreement; and still others with the effect of a breach of obligation by one party to the labor agreement upon the obligations of the other party. We propose in this article to analyze these decisions, to attempt to categorize the different kinds of challenges to arbitral jurisdiction or authority which can be made, and to assess, insofar as this may be done, the import of the Court\u27s decisions for the arbitration process. In a sense, we shall be dealing with the extent to which, under developing federal law, judicial review of the arbitration process is available
An X-Ray Study of the Supernova Remnant G290.1-0.8
G290.1-0.8 (MSH 11-61A) is a supernova remnant (SNR) whose X-ray morphology
is centrally bright. However, unlike the class of X-ray composite SNRs whose
centers are dominated by nonthermal emission, presumably driven by a central
pulsar, we show that the X-ray emission from G290.1-0.8 is thermal in nature,
placing the remnant in an emerging class which includes such remnants as W44,
W28, 3C391, and others. The evolutionary sequence which leads to such X-ray
properties is not well understood. Here we investigate two scenarios for such
emission: evolution in a cloudy interstellar medium, and early-stage evolution
of a remnant into the radiative phase, including the effects of thermal
conduction. We construct models for these scenarios in an attempt to reproduce
the observed center-filled X-ray properties of G290.1-0.8, and we derive the
associated age, energy, and ambient density conditions implied by the models.
We find that for reasonable values of the explosion energy, the remnant age is
of order (1 - 2) x 10^{4} yr. This places a fairly strong constraint on any
association between G290.1-0.8 and PSR J1105-610, which would require an
anomalously large velocity for the pulsar.Comment: 7 pages, 7 figures, ApJ, accepte
A New Class of non-Hermitian Quantum Hamiltonians with PT Symmetry
In a remarkable development Bender and coworkers have shown that it is
possible to formulate quantum mechanics consistently even if the Hamiltonian
and other observables are not Hermitian. Their formulation, dubbed PT quantum
mechanics, replaces hermiticity by another set of requirements, notably that
the Hamiltonian should be invariant under the discrete symmetry PT, where P
denotes parity and T denotes time reversal. All prior work has focused on the
case that time reversal is even (T^2 = 1). We generalize the formalism to the
case of odd time reversal (T^2 = -1). We discover an analogue of Kramer's
theorem for PT quantum mechanics, present a prototypical example of a PT
quantum system with odd time reversal, and discuss potential applications of
the formalism. Odd time reversal symmetry applies to fermionic systems
including quarks and leptons and a plethora of models in nuclear, atomic and
condensed matter physics. PT quantum mechanics makes it possible to enlarge the
set of possible Hamiltonians that physicists could deploy to describe
fundamental physics beyond the standard model or for the effective description
of condensed matter phenomena.Comment: Replaced submitted version with accepted version; to appear in Phys
Rev
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