922 research outputs found
Effect of annealing on glassy dynamics and non-Fermi liquid behavior in UCu_4Pd
Longitudinal-field muon spin relaxation (LF-muSR) experiments have been
performed in unannealed and annealed samples of the heavy-fermion compound
UCu_4Pd to study the effect of disorder on non-Fermi liquid behavior in this
material. The muon spin relaxation functions G(t,H) obey the time-field scaling
relation G(t,H) = G(t/H^gamma) previously observed in this compound. The
observed scaling exponent gamma = 0.3 pm 0.1, independent of annealing. Fits of
the stretched-exponential relaxation function G(t) = exp[-(Lambda t)^K] to the
data yielded stretching exponentials K < 1 for all samples. Annealed samples
exhibited a reduction of the relaxation rate at low temperatures, indicating
that annealing shifts fluctuation noise power to higher frequencies. There was
no tendency of the inhomogeneous spread in rates to decrease with annealing,
which modifies but does not eliminate the glassy spin dynamics reported
previously in this compound. The correlation with residual resistivity
previously observed for a number of NFL heavy-electron materials is also found
in the present work.Comment: 4 pages, 3 figures, submitted to 10th International Conference on
Muon Spin Rotation, Relaxation, and Resonance, Oxford, UK, August 200
Multiple Extremal Eigenpairs by the Power Method
We report the production and benchmarking of several refinements of the power
method that enable the computation of multiple extremal eigenpairs of very
large matrices. In these refinements we used an observation by Booth that has
made possible the calculation of up to the 10 eigenpair for simple test
problems simulating the transport of neutrons in the steady state of a nuclear
reactor. Here, we summarize our techniques and efforts to-date on determining
mainly just the two largest or two smallest eigenpairs. To illustrate the
effectiveness of the techniques, we determined the two extremal eigenpairs of a
cyclic matrix, the transfer matrix of the two-dimensional Ising model, and the
Hamiltonian matrix of the one-dimensional Hubbard model.Comment: 29 papes, no figure
Prosocial response to client-instigated victimization: the roles of forgiveness and workgroup conflict
We investigate forgiveness as a human service employee coping response to client-instigated victimizations and further explore the role of workgroup conflict in 1) facilitating this response, and 2) influencing the relationship between victimization and workplace outcomes. Using the theoretical lens of Conservation of Resources (Hobfoll, 1989), we propose that employees forgive clients – especially in the context of low workgroup conflict. From low to moderate levels of client-instigated victimization, we suggest that victimization and forgiveness are positively related; however, this positive relationship does not prevail when individuals confront egregious levels of victimization (i.e., an inverted-U shape). This curvilinear relationship holds under low but not under high workgroup conflict. Extending this model to workplace outcomes, findings also demonstrate that the indirect effects of victimization on job satisfaction, burnout, and turnover intentions are mediated by forgiveness when workgroup conflict is low. Experiment- and field-based studies provide evidence for the theoretical model
A Planarity Test via Construction Sequences
Optimal linear-time algorithms for testing the planarity of a graph are
well-known for over 35 years. However, these algorithms are quite involved and
recent publications still try to give simpler linear-time tests. We give a
simple reduction from planarity testing to the problem of computing a certain
construction of a 3-connected graph. The approach is different from previous
planarity tests; as key concept, we maintain a planar embedding that is
3-connected at each point in time. The algorithm runs in linear time and
computes a planar embedding if the input graph is planar and a
Kuratowski-subdivision otherwise
Spin-polaron model: transport properties of EuB
To understand anomalous transport properties of EuB, we have studied the
spin-polaron Hamiltonian incorporating the electron-phonon interaction.
Assuming a strong exchange interaction between the carriers and the localized
spins, the electrical conductivity is calculated. The temperature and magnetic
field dependence of the resistivity of EuB are well explained. At low
temperature, magnons dominate the conduction process, whereas the lattice
contribution becomes significant at very high temperature due to the scattering
with the phonons. Large negative magnetoresistance near the ferromagnetic
transition is also reproduced as observed in EuB.Comment: 4 pages, 3 figures, accepted in Phys. Rev.
Charmed and Bottom Baryons: a Variational Approach based on Heavy Quark Symmetry
The use of Heavy Quark Symmetry to study bottom and charmed baryons leads to
important simplifications of the non-relativistic three body problem, which
turns out to be easily solved by a simple variational ansatz. Our simple scheme
reproduces previous results (baryon masses, charge and mass radii, )
obtained by solving the Faddeev equations with simple non-relativistic
quark--quark potentials, adjusted to the light and heavy--light meson spectra.
Wave functions, parameterized in a simple manner, are also given and thus they
can be easily used to compute further observables. Our method has been also
used to find the predictions for strangeness-less baryons of the SU(2) chirally
inspired quark-quark interactions. We find that the one pion exchange term of
the chirally inspired interactions leads to relative changes of the
and binding energies as large as 90%.Comment: 20 pages, 5 figures. Revised version to be published in Nucl. Phys.
Strong Decays of Strange Quarkonia
In this paper we evaluate strong decay amplitudes and partial widths of
strange mesons (strangeonia and kaonia) in the 3P0 decay model. We give
numerical results for all energetically allowed open-flavor two-body decay
modes of all nsbar and ssbar strange mesons in the 1S, 2S, 3S, 1P, 2P, 1D and
1F multiplets, comprising strong decays of a total of 43 resonances into 525
two-body modes, with 891 numerically evaluated amplitudes. This set of
resonances includes all strange qqbar states with allowed strong decays
expected in the quark model up to ca. 2.2 GeV. We use standard nonrelativistic
quark model SHO wavefunctions to evaluate these amplitudes, and quote numerical
results for all amplitudes present in each decay mode. We also discuss the
status of the associated experimental candidates, and note which states and
decay modes would be especially interesting for future experimental study at
hadronic, e+e- and photoproduction facilities. These results should also be
useful in distinguishing conventional quark model mesons from exotica such as
glueballs and hybrids through their strong decays.Comment: 69 pages, 5 figures, 39 table
An integrated crisis communication framework for strategic crisis communication with the media: A case study on a financial services provider
In order for organisations to survive in an ever-changing milieu in the current business environment, sufficient crisis communication and management practices need to be in place to ensure organisational survival. Despite the latter, organisational crises are often inefficiently managed which could be ascribed to the lack of managing crises strategically (Kash & Darling 1998:180). This article explores the lack of strategic crisis communication processes to ensure effective crisis communication with the media as stakeholder group. It is argued that the media is one of the main influences of public opinion (Pollard & Hotho 2006:725), thereby emphasising the need for accurate distribution of information. Furthermore, the study will focus specifically on the financial industry, as it is believed that this industry is more sensitive and thus more prone towards media reporting as financial services providers manage people’s money (Squier 2009). A strategic crisis communication process with the media is therefore proposed, facilitated through an integrated crisis communication framework, which focuses on a combination of Integrated Communication (IC) literature with emphasis on Grunig’s theory of communication excellence to build sustainable media relationships through two-way communication; and proposing a crisis communication process that has proactive, reactive and post-evaluative crisis communication stages, thereby moving away from crisis communication as a predominant reactive function.Communication Scienc
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