9,060 research outputs found
Tables of joint probabilities useful in evaluating mixed acceptance sampling plans
Tables of joint probabilities useful in evaluating mixed acceptance sampling plan
An A Bailey lemma and Rogers--Ramanujan-type identities
Using new -functions recently introduced by Hatayama et al. and by (two
of) the authors, we obtain an A_2 version of the classical Bailey lemma. We
apply our result, which is distinct from the A_2 Bailey lemma of Milne and
Lilly, to derive Rogers-Ramanujan-type identities for characters of the W_3
algebra.Comment: AMS-LaTeX, 25 page
Coaxial prime focus feeds for paraboloidal reflectors
A TE11 - TM11 dual mode coaxial feed for use in prime focus paraboloidal antenna systems is investigated. The scattering matrix parameters of the internal bifurcation junction was determined by the residue calculus technique. The scattering parameters and radiation fields of the aperture were found from the Weinstein solution. The optimum modeing ratio for minimum cross-polarization was determined along with the corresponding optimum feed dimensions. A peak cross-polarization level of -58 dB is predicted. The frequency characteristics were also investigated and a bandwidth of 5% is predicted over which the cross-polarization remains below -30 dB, the input VSWR is below 1.15, and the phase error is less than 10 deg. Theoretical radiation patterns and efficiency curves for a paraboloidal reflector illuminated by this feed were computed. The predicted sidelobe level is below -30 dB and aperture efficiencies greater than 70% are possible. Experimental results are also presented that substantiates the theoretical results. In addition, experimental results for a 'short-cup' coaxial feed are given. The report includes extensive design data for the dual-mode feed along with performance curves showing cross-polarization as a function of feed parameters. The feed is useful for low-cost ground based receiving antennas for use in direct television satellite broadcasting service
Der zweite Tod des Autors?:Metamorphosen der Postmoderne in Christoph Ransmars "Die letzte Welt"
In seinem Beitrag zu Christoph Ransmayrs ‚Die letzte Welt setzt sich Erik Schilling mit den Möglichkeiten des historischen Romans für das postmoderne Schreiben auseinander. Anhand von Michel Foucaults Konzept der Heterotopie geht der Autor dem Übergang des Zentrums in die Peripherie nach und stellt durch Untersuchung von Raum und Zeit die selbstreflexiven Strukturen des Romans heraus
Crystal nucleation mechanism in melts of short polymer chains under quiescent conditions and under shear flow
We present a molecular dynamics simulation study of crystal nucleation from
undercooled melts of n-alkanes, and we identify the molecular mechanism of
homogeneous crystal nucleation under quiescent conditions and under shear flow.
We compare results for n-eicosane(C20) and n-pentacontahectane(C150), i.e. one
system below the entanglement length and one above. Under quiescent conditions,
we observe that entanglement does not have an effect on the nucleation
mechanism. For both chain lengths, the chains first align and then straighten
locally. Then the local density increases and finally positional ordering sets
in. At low shear rates the nucleation mechanism is the same as under quiescent
conditions, while at high shear rates the chains align and straighten at the
same time. We report on the effects of shear rate and temperature on the
nucleation rates and estimate the critical shear rates, beyond which the
nucleation rates increase with the shear rate. We show that the viscosity of
the system is not affected by the crystalline nuclei.Comment: 9 page
Heralded Entanglement of Arbitrary Degree in Remote Qubits
Incoherent scattering of photons off two remote atoms with a Lambda-level
structure is used as a basic Young-type interferometer to herald long-lived
entanglement of an arbitrary degree. The degree of entanglement, as measured by
the concurrence, is found to be tunable by two easily accessible experimental
parameters. Fixing one of them to certain values unveils an analog to the
Malus' law. An estimate of the variation in the degree of entanglement due to
uncertainties in an experimental realization is given.Comment: published version, 4 pages and 2 figure
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