1,241 research outputs found
Desingularization of vortices for the Euler equation
We study the existence of stationary classical solutions of the
incompressible Euler equation in the plane that approximate singular
stationnary solutions of this equation. The construction is performed by
studying the asymptotics of equation -\eps^2 \Delta
u^\eps=(u^\eps-q-\frac{\kappa}{2\pi} \log \frac{1}{\eps})_+^p with Dirichlet
boundary conditions and a given function. We also study the
desingularization of pairs of vortices by minimal energy nodal solutions and
the desingularization of rotating vortices.Comment: 40 page
Optimization of mobile phase composition for preparative separation of profens enantiomers by chiral liquid chromatography
In this paper it will be presented and discussed the experimental and simulation results obtained for the preparative separation of ketoprofen and flurbiprofen enantiomers by chiral liquid chromatography. Experimental results include solubility studies, elution and frontal chromatographic experiments and the measurement of competitive adsorption isotherms, using different mobile phase compositions. Modeling and simulation tools are used to predict the behavior and the performance of fixed bed and simulated moving bed processes. These prediction tools are used to select the proper mobile phase composition for the enantiomers separation in a preparative and production-scale point of view
Durability of concrete structures in marine atmosphere zones – The use of chloride deposition rate on the wet candle as an environmental indicator
Durability of concrete structures under marine environments has been studied for a long time. This work was focused on marine atmosphere zone and studied the deposition of chlorides on wet candle devices and its relation with chlorides accumulated into concrete. Concrete specimens with three different mixtures were exposed at places located at four different distances from the sea. Periodically, chloride profiles were obtained and analysed taking into account environmental data. Results of numerical extrapolations show that chloride deposition rate on the wet candle can be used as an environmental indicator, helping to preview the expectancy of service life of concrete structures or suggesting minimum concrete cover thicknesses for a required service life. Regarding the studied region, service life decreases between 30% and 60% were observed when changing chloride deposition from 120 mg/m2 day to 500 mg/m2 day, which shows that chloride deposition plays an important role as an environmental indicator on service-life analysis of concrete structures in marine atmosphere zone
Consumer brand choice: Money allocation as a function of brand reinforcing attributes
Previous applications of the matching law to the analysis of consumer brand choice have shown that the amount of money spent purchasing a favorite brand tends to match the quantity bought of the favorite brand divided by the quantity bought of all other brands. Although these results suggest matching between spending and purchased quantity, branded goods differ qualitatively among themselves, rendering previous matching analyses incomplete. Consumer panel data containing information about more than 1,500 British consumers purchasing four grocery product categories (baked beans, biscuits, fruit juice, and yellow fats) during 52 weeks were analyzed. All the brands purchased were classified according to the level of informational and utilitarian reinforcement they were programmed to offer. An adaptation of the generalized matching law was adopted, in which the amount of money spent was a power function of the quantity bought, informational level of the brand bought, utilitarian level of the brand bought, and a measure of price promotion
Local fluctuations in quantum critical metals
We show that spatially local, yet low-energy, fluctuations can play an
essential role in the physics of strongly correlated electron systems tuned to
a quantum critical point. A detailed microscopic analysis of the Kondo lattice
model is carried out within an extended dynamical mean-field approach. The
correlation functions for the lattice model are calculated through a
self-consistent Bose-Fermi Kondo problem, in which a local moment is coupled
both to a fermionic bath and to a bosonic bath (a fluctuating magnetic field).
A renormalization-group treatment of this impurity problem--perturbative in
, where is an exponent characterizing the spectrum
of the bosonic bath--shows that competition between the two couplings can drive
the local-moment fluctuations critical. As a result, two distinct types of
quantum critical point emerge in the Kondo lattice, one being of the usual
spin-density-wave type, the other ``locally critical.'' Near the locally
critical point, the dynamical spin susceptibility exhibits scaling
with a fractional exponent. While the spin-density-wave critical point is
Gaussian, the locally critical point is an interacting fixed point at which
long-wavelength and spatially local critical modes coexist. A Ginzburg-Landau
description for the locally critical point is discussed. It is argued that
these results are robust, that local criticality provides a natural description
of the quantum critical behavior seen in a number of heavy-fermion metals, and
that this picture may also be relevant to other strongly correlated metals.Comment: 20 pages, 12 figures; typos in figure 3 and in the main text
corrected, version as publishe
Consumer Behaviour Analysis and Consumer Brand Choice
This is the SECOND of TWO linked articles on consumer behavioural analysis dealing with the Behavioural Perspective Model, which locates consumer behaviour at the intersection of the consumer’s learning history and the consumer situation. As an example of research inspired by the Model, this article presents investigations into consumers’ patterns of brand choice, showing how brand repertoires are formed and how brands are selected within those repertoires
Consumer Behaviour Analysis and the Behavioural Perspective Model
This is the FIRST of TWO linked articles on consumer behavioural analysis. Cognitive theories have dominated the field of consumer behaviour for the last few decades, however, an observed lack of consistency between attitudes and behaviour has suggested the need to investigate more thoroughly situational and behavioural variables. Consumer behaviour analysis can be viewed as an alternative theoretical approach that emphasizes situational variables and measures of behaviour. Within consumer behaviour analysis, the Behavioural Perspective Model (BPM) interprets consumer behaviour as occurring at the intersection of the individual’s learning history and the consumer setting, which signals utilitarian and informational consequences associated with consumption-related responses. Utilitarian consequences are mediated by the product or service and are related to its functional benefits. Informational consequences are social, mediated by other people, and are related to feedback upon consumers’ behaviour, such as social status and prestige
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
Consumer-based brand equity and brand performance
The relation between consumer-based brand equity and brand performance was investigated across 15 product categories in Brazil and the UK. Brand equity was conceptualized as related to the level of social benefit offered by each brand and was measured with a simple questionnaire that asked consumers to rate brands with respect to their familiarity and quality levels. These measures were then related to brand market share and revenue. Results showed that the relation between consumer-based brand equity and brand performance varies across product categories, indicating that products differ with respect to their level of brandability and suggesting ways to measure it
Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter
Data collected by the Pierre Auger Observatory through 31 August 2007 showed
evidence for anisotropy in the arrival directions of cosmic rays above the
Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{eV}. The
anisotropy was measured by the fraction of arrival directions that are less
than from the position of an active galactic nucleus within 75 Mpc
(using the V\'eron-Cetty and V\'eron catalog). An updated
measurement of this fraction is reported here using the arrival directions of
cosmic rays recorded above the same energy threshold through 31 December 2009.
The number of arrival directions has increased from 27 to 69, allowing a more
precise measurement. The correlating fraction is , compared
with expected for isotropic cosmic rays. This is down from the early
estimate of . The enlarged set of arrival directions is
examined also in relation to other populations of nearby extragalactic objects:
galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in
hard X-rays by the Swift Burst Alert Telescope. A celestial region around the
position of the radiogalaxy Cen A has the largest excess of arrival directions
relative to isotropic expectations. The 2-point autocorrelation function is
shown for the enlarged set of arrival directions and compared to the isotropic
expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201
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