16,887 research outputs found
Strategic manoeuvres and impression management: communication approaches in the case of a crisis event
This historical study examines the actions of the Australian former asbestos company, James Hardie, when faced with a potentially ruinous corporate scandal between 2001 and 2007. The company became vilified as public awareness grew of the damage to public health its use of asbestos had caused. In response, it set- up a knowingly underfunded compensation fund supported by a strategy of misinformation and denial. Its actions are analysed using Oliver’s typology of strategic responses and theories of crisis management and crisis communications, providing insights into the company’s motivations for adopting strategies that took it to the brink of financial collaps
Energy spectrum of the relativistic Dirac-Morse problem
We derive an elegant analytic formula for the energy spectrum of the
relativistic Dirac-Morse problem, which has been solved recently. The new
formula displays the properties of the spectrum more vividly.Comment: Replaced with a more potrable PDF versio
WMAP confirming the ellipticity in BOOMERanG and COBE CMB maps
The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB)
radiation maps have detected ellipticity of the temperature anisotropy spots
independent on the temperature threshold. The effect has been found for spots
up to several degrees in size, where the biases of the ellipticity estimator
and of the noise are small. To check the effect, now we have studied, with the
same algorithm and in the same sky region, the WMAP maps. We find ellipticity
of the same average value also in WMAP maps, despite of the different
sensitivity of the two experiments to low multipoles. Large spot elongations
had been detected also for the COBE-DMR maps. If this effect is due to geodesic
mixing and hence due to non precisely zero curvature of the hyperbolic
Universe, it can be linked to the origin of WMAP low multipoles anomaly.Comment: More explanations and two references adde
Is there a common origin for the WMAP low multipole and for the ellipticity in BOOMERanG CMB maps?
We have measured the ellipticity of several degree scale anisotropies in the
BOOMERanG maps of the Cosmic Microwave Background (CMB) at 150 GHz. The average
ellipticity is around 2.6-2.7. The biases of the estimator of the ellipticity
and for the noise are small in this case. Large spot elongation had been
detected also for COBE-DMR maps. If this effect is due to geodesic mixing, it
would indicate a non precisely zero curvature of the Universe which is among
the discussed reasons of the WMAP low multipole anomaly. Both effects are
related to the diameter of the Universe: the geodesics mixing through
hyperbolic geometry, low multipoles through boundary conditions.This common
reason can also be related with the origin of the the cosmological constant:
the modes of vacuum fluctuations conditioned by the boundary conditions lead to
a value of the cosmological constant being in remarkable agreement with the
supernovae observations.Comment: Added: two co-authors and a comment on the possible relation of the
discussed CMB properties with the origin of the observed value of the
cosmological constan
The trispectrum of the Cosmic Microwave Background on sub-degree angular scales: an analysis of the BOOMERanG data
The trispectrum of the cosmic microwave background can be used to assess the
level of non-Gaussianity on cosmological scales. It probes the fourth order
moment, as a function of angular scale, of the probability distribution
function of fluctuations and has been shown to be sensitive to primordial
non-gaussianity, secondary anisotropies (such as the Ostriker-Vishniac effect)
and systematic effects (such as astrophysical foregrounds). In this paper we
develop a formalism for estimating the trispectrum from high resolution sky
maps which incorporates the impact of finite sky coverage. This leads to a
series of operations applied to the data set to minimize the effects of
contamination due to the Gaussian component and correlations between estimates
at different scales. To illustrate the effect of the estimation process, we
apply our procedure to the BOOMERanG data set and show that it is consistent
with Gaussianity. This work presents the first estimation of the CMB
trispectrum on sub-degree scales.Comment: 14 pages, submitted to MNRA
Brief review on semileptonic B decays
We concisely review semileptonic B decays, focussing on recent progress on
both theoretical and experimental sides.Comment: 18 pages, 2 figures; version to be published in Mod. Phys. Lett.
Realization of microwave quantum circuits using hybrid superconducting-semiconducting nanowire Josephson elements
We report the realization of quantum microwave circuits using hybrid
superconductor-semiconductor Josephson elements comprised of InAs nanowires
contacted by NbTiN. Capacitively-shunted single elements behave as transmon
qubits with electrically tunable transition frequencies. Two-element circuits
also exhibit transmon-like behavior near zero applied flux, but behave as flux
qubits at half the flux quantum, where non-sinusoidal current-phase relations
in the elements produce a double-well Josephson potential. These hybrid
Josephson elements are promising for applications requiring microwave
superconducting circuits operating in magnetic field.Comment: Main text: 4 pages, 4 figures; Supplement: 10 pages, 8 figures, 1
tabl
MAXIMA: an experiment to measure temperature anisotropy in the cosmic microwave background
We describe the MAXIMA experiment, a balloon-borne measurement designed to
map temperature anisotropy in the Cosmic Microwave Background (CMB) over a wide
range of angular scales (multipole range 80 < l < 800). The experiment consists
of a 1.3 m diameter off-axis Gregorian telescope and a receiver with a 16
element array of bolometers cooled to 100 mK. The frequency bands are centered
at 150, 240, and 410 GHz. The 10' FWHM beam sizes are well matched to the scale
of acoustic peaks expected in the angular power spectrum of the CMB. The first
flight of the experiment in its full configuration was launched in August 1998.
A 122 sq-deg map of the sky was made near the Draco constellation during the 7
hour flight in a region of extremely low galactic dust contamination. This map
covers 0.3% of the sky and has 3200 independent beamsize pixels. We describe
the MAXIMA instrument and its performance during the recent flight.Comment: To appear in proceedings of `3K Cosmology', ed. F Melchiorri,
Conference held Oct 5-10 1998, Rome, 13 pages LaTeX (using aipproc2.sty &
aipproc2.cls), Postscript with higher resolution graphics available at
http://cfpa.berkeley.edu/group/cmb/gen.htm
Observation of Andreev Reflection Enhanced Shot Noise
We have experimentally investigated the quasiparticle shot noise in
NbN/MgO/NbN superconductor - insulator - superconductor tunnel junctions. The
observed shot noise is significantly larger than theoretically expected. We
attribute this to the occurrence of multiple Andreev reflection processes in
pinholes present in the MgO barrier. This mechanism causes the current to flow
in large charge quanta (Andreev clusters), with a voltage dependent average
value of m = 1+ 2 Delta/eV times the electron charge. Because of this charge
enhancement effect, the shot noise is increased by the factor m.Comment: 4 pages, 5 figures include
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