7,128 research outputs found
On the Coexistence Magnetism/Superconductivity in the Heavy-Fermion Superconductor CePtSi
The interplay between magnetism and superconductivity in the newly discovered
heavy-fermion superconductor CePtSi has been investigated using the
zero-field SR technique. The SR data indicate that the whole muon
ensemble senses spontaneous internal fields in the magnetic phase,
demonstrating that magnetism occurs in the whole sample volume. This points to
a microscopic coexistence between magnetism and heavy-fermion
superconductivity.Comment: Final version, new figure structure, references correcte
Magnetic field induced non-Fermi liquid to Fermi liquid crossover at the quantum critical point of YbCuAu
The temperature (T) dependence of the muon and Cu nuclear spin-lattice
relaxation rates in YbCu4.4Au0.6 is reported over nearly four decades.
It is shown that for diverges following the behaviour
predicted by the self-consistent renormalization (SCR) theory developed by
Moriya for a ferromagnetic quantum critical point. On the other hand, the
static uniform susceptibility is observed to diverge as and
, a behaviour which is not accounted for by SCR theory.
The application of a magnetic field is observed to induce a crossover to a
Fermi liquid behaviour and for is found to obey the scaling
law .Comment: 4 pages, 4 figure
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A moving-mesh finite element method and its application to the numerical solution of phase-change problems
A distributed Lagrangian moving-mesh finite element method is applied to problems involving changes of phase. The algorithm uses a distributed conservation principle to determine nodal mesh velocities, which are then used to move the nodes. The nodal values are obtained from an ALE (Arbitrary Lagrangian-Eulerian) equation, which represents a generalization of the original algorithm presented in Applied Numerical Mathematics, 54:450--469 (2005). Having described the details of the generalized algorithm it is validated on two test cases from the original paper and is then applied to one-phase and, for the first time, two-phase Stefan problems in one and two space dimensions, paying particular attention to the implementation of the interface boundary conditions. Results are presented to demonstrate the accuracy and the effectiveness of the method, including comparisons against analytical solutions where available
Asymmetry in Leader Image Effects and the Implications for Leadership Positioning in the 2010 British General Election
Using national survey data on voters' perceptions of party leaders during the 2010 British general election campaign, we use logistic regression analysis to explore the association between specific image attributes and overall satisfaction for each leader. We find attribute-satisfaction relationships differ in some respects between the three main party leaders, demonstrating that leader image effects are not symmetrical across leaders. We find evidence that negative perceptions have more powerful effects on satisfaction than positive ones, implying that parties should seek to determine a leader's image attribute perceptions measured against the public's expectations of them on the same dimensions. The positions that campaigners ought then to choose are those that will have the most beneficial effect in encouraging voting behaviour for each particular leader or discouraging voting behaviour for an opponent
'White knuckle care work' : violence, gender and new public management in the voluntary sector
Drawing on comparative data from Canada and Scotland, this article explores reasons why violence is tolerated in non-profit care settings. This article will provide insights into how workers' orientations to work, the desire to care and the intrinsic rewards from working in a non-profit context interact with the organization of work and managerially constructed workplace norms and cultures (Burawoy, 1979) to offset the tensions in an environment characterized by scarce resources and poor working conditions. This article will also outline how the same environment of scarce resources causes strains in management's efforts to establish such cultures. Working with highly excluded service users with problems that do not respond to easy interventions, workers find themselves working at the edge of their endurance, hanging on by their fingernails, and beginning to participate in various forms of resistance; suggesting that even among the most highly committed, 'white knuckle care' may be unsustainable
Technological impacts on market attitudes and behaviors
Technology has had a profound effect on twentieth century society and is increasingly changing the nature of the way we live our lives in the twenty first century, particularly, but not solely, through innovations in digital and social media marketing. As media and other technologies change, the question arising concerns how these changes impact on consumers’ attitudes and behaviors, and consequently on their lives. In this special edition, nine papers are presented, outlining cutting-edge research exploring how changing technologies affect consumer attitudes, emotions and behaviors in a variety of country settings and industries. In this introductory editorial, the papers are outlined in further detail, with a brief exposition of their contribution
1932 The Analysis
WE HAVE toiled, tried to co-operate and now we lay down our efforts. We sincerely hope that the records are accurate. The book contains the amusing and outstanding events that we as a staff carry out into life. Perhaps our vision has been blurred and missed some features, for this we apologize. The humor, we hope, will be looked upon fairly and may it be appreciated to the fullest, with malice to none. The rest lies with public opinion.https://jdc.jefferson.edu/analysis/1004/thumbnail.jp
On the spectroastrometric separation of binary point-source fluxes
Spectroastrometry is a technique which has the potential to resolve flux
distributions on scales of milliarcseconds. In this study, we examine the
application of spectroastrometry to binary point sources which are spatially
unresolved due to the observational point spread function convolution. The
technique uses measurements with sub-pixel accuracy of the position centroid of
high signal-to-noise long-slit spectrum observations. With the objects in the
binary contributing fractionally more or less at different wavelengths
(particularly across spectral lines), the variation of the position centroid
with wavelength provides some information on the spatial distribution of the
flux. We examine the width of the flux distribution in the spatial direction,
and present its relation to the ratio of the fluxes of the two components of
the binary. Measurement of three observables (total flux, position centroid and
flux distribution width) at each wavelength allows a unique separation of the
total flux into its component parts even though the angular separation of the
binary is smaller than the observations' point-spread function. This is because
we have three relevant observables for three unknowns (the two fluxes, and the
angular separation of the binary), which therefore generates a closed problem.
This is a wholly different technique than conventional deconvolution methods,
which produce information on angular sizes of the sampling scale.
Spectroastrometry can produce information on smaller scales than conventional
deconvolution, and is successful in separating fluxes in a binary object with a
separation of less than one pixel. We present an analysis of the errors
involved in making binary object spectroastrometric measurements and the
separation method, and highlight necessary observing methodology.Comment: 11 pages, 8 figures, accepted for publication in Astronomy and
Astrophysic
Sub-milliarcsecond precision spectro-astrometry of Be stars
The origin of the disks around Be stars is still not known. Further progress
requires a proper parametrization of their structure, both spatially and
kinematically. This is challenging as the disks are very small. Here we assess
whether a novel method is capable of providing these data. We obtained spectro
astrometry around the Pa beta line of two bright Be stars, alpha Col and zeta
Tau, to search for disk signatures. The data, with a pixel to pixel precision
of the centroid position of 0.3..0.4 milliarcsecond is the most accurate such
data to date. Artefacts at the 0.85 mas level are present in the data, but
these are readily identified as they were non-repeatable in our redundant
datasets. This does illustrate the need of taking multiple data to avoid
spurious detections. The data are compared with simple model simulations of the
spectro astrometric signatures due to rotating disks around Be stars. The upper
limits we find for the disk radii correspond to disk sizes of a few dozen
stellar radii if they rotate Keplerian. This is very close to observationally
measured and theoretically expected disk sizes, and this paper therefore
demonstrates that spectro-astrometry, of which we present the first such
attempt, has the potential to resolve the disks around Be stars.Comment: 6 pages, A&A accepte
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