2,532 research outputs found
Theory of nonequilibrium dynamics of multiband superconductors
We study the nonequilibrium dynamics of multiband BCS superconductors
subjected to ultrashort pump pulses. Using density-matrix theory, the time
evolution of the Bogoliubov quasiparticle densities and the superconducting
order parameters are computed as a function of pump pulse frequency, duration,
and intensity. Focusing on two-band superconductors, we consider two different
model systems. The first one, relevant for iron-based superconductors,
describes two-band superconductors with a repulsive interband interaction
which is much larger than the intraband pairing terms. The second
model, relevant for MgB, deals with the opposite limit where the intraband
interactions are dominant and the interband pair scattering is weak
but attractive. For ultrashort pump pulses, both of these models exhibit a
nonadiabatic behavior which is characterized by oscillations of the
superconducting order parameters. We find that for nonvanishing , the
superconducting gap on each band exhibits two oscillatory frequencies which are
determined by the long-time asymptotic values of the gaps. The relative
strength of these two frequency components depends sensitively on the magnitude
of the interband interaction .Comment: 6 pages, 3 figure
Exploring field scale salinity using simulation modeling, example for Rudasht area, Esfahan Province, Iran
Salinity / Simulation models / Soil-water-plant relationships / Soil properties / Climate / Irrigated farming / Water quality / Iran / Esfahan Province / Rudasht Area
Dielectric Susceptibility and Heat Capacity of Ultra-Cold Glasses in Magnetic Field
Recent experiments demonstrated unexpected, even intriguing properties of
certain glassy materials in magnetic field at low temperatures. We have studied
the magnetic field dependence of the static dielectric susceptibility and the
heat capacity of glasses at low temperatures. We present a theory in which we
consider the coupling of the tunnelling motion to nuclear quadrupoles in order
to evaluate the static dielectric susceptibility. In the limit of weak magnetic
field we find the resonant part of the susceptibility increasing like
while for the large magnetic field it behaves as 1/B. In the same manner we
consider the coupling of the tunnelling motion to nuclear quadrupoles and
angular momentum of tunnelling particles in order to find the heat capacity.
Our results show the Schotky peak for the angular momentum part, and
dependence for nuclear quadrupoles part of heat capacity, respectively. We
discuss whether or not this approach can provide a suitable explanation for
such magnetic properties.Comment: 10 pages, 1 figur
A methodology for project portfolio selection under criteria prioritisation, uncertainty and projects interdependency – combination of fuzzy QFD and DEA
© 2018 Elsevier Ltd Resources of an organisation (people, time, money, equipment, etc) are never endless. As such, a constant and continuous challenge for decision makers is to decide which projects should be given priority in terms of receiving critical resources in a way that the organisation's productivity and profitability is best guaranteed. Previous literature has already developed a plenitude of project portfolio selection methodologies ranging from simple scoring to complex mathematical models. However, most of them too often fail to propose one integrated and seamless method that can simultaneously take into account three important elements: (1) prioritisation of selection criteria over each other, (2) uncertainty in decision-making, and (3) projects interdependencies. This paper aims to fill this gap by proposing an integrated method that can simultaneously address all these three aspects. The proposed method combines Quality Function Development (QFD), fuzzy logic, and Data Envelopment Analysis (DEA) to accounts for prioritisation, uncertainty and interdependency. We then apply this method in a numerical example from a real world case to illustrate the applicability and efficacy of the proposed methodology
Nonlinear ion waves in Fermi-Dirac pair plasmas
Arbitrary amplitude nonlinear ion waves is investigated in an extremely
degenerate electron-positron-ion plasma with relativistic electrons/positrons
and dynamic cold ions using Sagdeev pseudo-potential method in framework of
quantum hydrodynamics model. The matching criteria of existence for ion
solitary as well as periodic nonlinear excitations is studied numerically in
terms of the relativistic degeneracy parameter, relative positron concentration
and the relativistic normalized propagation-speed range of these waves are
obtained. It is remarked that the electron relativistic degeneracy and relative
positron concentration in such plasmas have significant effects on nonlinear
wave propagations in relativistically degenerate Fermi-Dirac plasma. Our
results are in good agreement with the previously reported ones obtained using
semiclassical Thomas-Fermi approximation in dense plasmas with non-relativistic
and ultra-relativistic electrons and positrons. Current findings can be
appropriate for the study of astrophysical superdense compact objects such as
white dwarfs.Comment: Published in Physics of Plasma
The one thing you need to change is emotions: the effect of multi-sensory marketing on consumer behavior
Retailers are increasingly aware of the importance of store atmosphere on consumers’ emotions. The results of four experimental studies demonstrate that the sensory cues by which customers sense products and the amount of (in)congruency among the sensory stimuli of the products affect consumers’ emotions, willingness to purchase, and experience. In the presence of moderators such as colors, jingles, prices, and scent imagery, when facing sensory-rich experiential products (e.g., juice, coffee, hamburger, soda) with different sensory cues, consumers’ emotions, willingness to purchase, and experience depend on affective primacy and sensory congruency. The results (1) facilitate an improved consideration of the role of the interaction of sensory cues on customer emotions, (2) have consequences for outcomes linked with sensory congruency and affective primacy, and (3) help clarify possible incoherence in preceding studies on cross-modal outcomes in the setting of multi-sensory marketing
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