6,546 research outputs found
Near room-temperature colossal magnetodielectricity and multiglass properties in partially-disordered La2NiMnO6
We report magnetic, dielectric and magnetodielectric responses of pure
monoclinic bulk phase of partially-disordered La2NiMnO6, exhibiting a spectrum
of unusual properties and establish that this system intrinsically is a true
multiglass with a large magnetodielectric coupling (8-20%) over a wide range of
temperatures (150 - 300 K). Specifically, our results establish a unique way to
obtain colossal magnetodielectricity, independent of any striction effects, by
engineering the asymmetric hopping contribution to the dielectric constant via
the tuning of the relative spin orientations between neighboring magnetic ions
in a transition metal oxide system. We discuss the role of anti-site (Ni-Mn)
disorder in emergence of these unusual properties.Comment: 5 pages, 4 figures, Slightly revised version of previous article in
condmat: arXiv:1202.4319v
Carbon stars in the X-shooter Spectral Library
We provide a new collection of spectra of 35 carbon stars obtained with the
ESO/VLT X-shooter instrument as part of the X-shooter Spectral Library project.
The spectra extend from 0.3m to 2.4m with a resolving power above
8000. The sample contains stars with a broad range of (J-K) color and
pulsation properties located in the Milky Way and the Magellanic Clouds. We
show that the distribution of spectral properties of carbon stars at a given
(J-K) color becomes bimodal (in our sample) when (J-K) is larger than about
1.5. We describe the two families of spectra that emerge, characterized by the
presence or absence of the absorption feature at 1.53m, generally
associated with HCN and CH. This feature appears essentially only in
large-amplitude variables, though not in all observations. Associated spectral
signatures that we interpret as the result of veiling by circumstellar matter,
indicate that the 1.53m feature might point to episodes of dust production
in carbon-rich Miras.Comment: 29 pages, 21 figures, 9 tables, Accepted for publication in A&
Large Non-perturbative Effects of Small \Delta m^2_{21}/\Delta m^2_{31} and \sin \theta_{13} on Neutrino Oscillation and CP Violation in Matter
In the framework of three generations, we consider the CP violation in
neutrino oscillation with matter effects. At first, we show that the
non-perturbative effects of two small parameters, \Delta m_{21}^2/\Delta
m_{31}^2 and \sin \theta_{13}, become more than 50% in certain ranges of energy
and baseline length. This means that the non-perturbative effects should be
considered in detailed analysis in the long baseline experiments. Next, we
propose a method to include these effects in approximate formulas for
oscillation probabilities. Assuming the two natural conditions,
\theta_{23}=45^\circ and the fact that the matter density is symmetric, a set
of approximate formulas, which involve the non-perturbative effects, has been
derived in all channels.Comment: 25 pages, 4 figures, version to appear in JHE
Lepton polarization asymmetry in radiative dileptonic B-meson decays in MSSM
In this paper we study the polarization asymmetries of the final state lepton
in the radiative dileptonic decay of B meson (\bsllg) in the framework of
Minimal Supersymmetric Standard Model (MSSM) and various other unified models
within the framework of MSSM e.g. mSUGRA, SUGRA (where condition of
universality of scalar masses is relaxed) etc. Lepton polarization, in addition
of having a longitudinal component (\pl), can have two other components, \pt
and \pn, lying in and perpendicular to the decay plane, which are proportional
to \ml and hence are significant for final state being or
. We analyse the dependence of these polarization asymmetries
on the parameters of the various models.Comment: typos corrected to match with published versio
A systematic literature review of the use of social media for business process management
In today’s expansion of new technologies, innovation is found necessary for organizations to be up to date with the latest management trends. Although organizations are increasingly using new technologies, opportunities still exist to achieve the nowadays essential omnichannel management strategy. More precisely, social media are opening a path for benefiting more from an organization’s process orientation. However, social media strategies are still an under-investigated field, especially when it comes to the research of social media use for the management and improvement of business processes or the internal way of working in organizations. By classifying a variety of articles, this study explores the evolution of social media implementation within the BPM discipline. We also provide avenues for future research and strategic implications for practitioners to use social media more comprehensively
Tuning of dielectric properties and magnetism of SrTiO3 by site-specific doping of Mn
Combining experiments with first principles calculations, we show that
site-specific doping of Mn into SrTiO3 has a decisive influence on the
dielectric properties of these doped systems. We find that phonon contributions
to the dielectric constant invariably decrease sharply on doping at any site.
However, a sizable, random dipolar contribution only for Mn at the Sr site
arises from a strong off-centric displacement of Mn in spite of Mn being in a
non-d0 state; this leads to a large dielectric constant at higher temperatures
and gives rise to a relaxor ferroelectric behavior at lower temperatures. We
also investigate magnetic properties in detail and critically reevaluate the
possibility of a true multi-glass state in such systems.Comment: 24 Pages, 2 Tables, 9 Figure
A construção do movimento sindical de trabalhadores como superação de exclusão do campesinato.
Síntese da história e evolução do campesinato brasileiro.bitstream/item/142608/1/ID-34374.pd
Observation of Individual Josephson Vortices in YBCO Bicrystal Grain-boundary Junctions
The response of YBCO bicrystal grain-boundary junctions to small dc magnetic
fields (0 - 10 Oe) has been probed with a low-power microwave (rf) signal of
4.4 GHz in a microwave-resonator setup. Peaks in the microwave loss at certain
dc magnetic fields are observed that result from individual Josephson vortices
penetrating into the grain-boundary junctions under study. The system is
modeled as a long Josephson junction described by the sine-Gordon equation with
the appropriate boundary conditions. Excellent quantitative agreement between
the experimental data and the model has been obtained. Hysteresis effect of dc
magnetic field is also studied and the results of measurement and calculation
are compared.Comment: 11 pages, 4 figure
de Sitter branes with a bulk scalar
We propose new braneworld models arising from a scalar field in the bulk. In
these examples, the induced on--brane line element is de Sitter (or anti de
Sitter) and the bulk (five dimensional) Einstein equations can be exactly
solved to obtain warped spacetimes. The solutions thus derived are single and
two-brane models -- one with {\em thin} branes while the other one of the {\em
thick} variety. The field profiles and the potentials are obtained and analysed
for each case. We note that for the {\em thick} brane scenario the field
profile resembles a kink, whereas for one or more {\em thin} branes, it is
finite and bounded in the domain of the extra dimension. We have also addressed
the localisation of gravity and other matter fields on the brane for these
braneworld models.Comment: 18 pages, 5 figures. Substantial changes and new results. To appear
in GR
Searching for new physics in decays
For any new physics possibly emerging in the future B experiments, the
problem is how to extract the signals from the SM background. We consider the
decay which is very small in the SM. In the MSSM this decay is
possibly accessible in the future experiments. In the supersymmetric models
with R-parity violating couplings, this channel is not strictly constrained,
thus being useful in obtaining bounds on the lepton-number violating couplings.
A typical candidate for the suggested search is the mode.Comment: 9 pages, one figure, late
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