46,800 research outputs found
Tipstreaming of a drop in simple shear flow in the presence of surfactant
We have developed a multi-phase SPH method to simulate arbitrary interfaces
containing surface active agents (surfactants) that locally change the
properties of the interface, such the surface tension coefficient. Our method
incorporates the effects of surface diffusion, transport of surfactant from/to
the bulk phase to/from the interface and diffusion in the bulk phase.
Neglecting transport mechanisms, we use this method to study the impact of
insoluble surfactants on drop deformation and breakup in simple shear flow and
present the results in a fluid dynamics video.Comment: Two videos are included for the Gallery of Fluid Motion of the APS
DFD Meeting 201
The Universal Edge Physics in Fractional Quantum Hall Liquids
The chiral Luttinger liquid theory for fractional quantum Hall edge transport
predicts universal power-law behavior in the current-voltage (-)
characteristics for electrons tunneling into the edge. However, it has not been
unambiguously observed in experiments in two-dimensional electron gases based
on GaAs/GaAlAs heterostructures or quantum wells. One plausible cause is the
fractional quantum Hall edge reconstruction, which introduces non-chiral edge
modes. The coupling between counterpropagating edge modes can modify the
exponent of the - characteristics. By comparing the fractional
quantum Hall states in modulation-doped semiconductor devices and in graphene
devices, we show that the graphene-based systems have an experimental
accessible parameter region to avoid the edge reconstruction, which is suitable
for the exploration of the universal edge tunneling exponent predicted by the
chiral Luttinger liquid theory.Comment: 7 pages, 6 figure
Relativistic description of magnetic moments in nuclei with doubly closed shells plus or minus one nucleon
Using the relativistic point-coupling model with density functional PC-PK1,
the magnetic moments of the nuclei Pb, Pb, Tl and
Bi with a closed-shell core Pb are studied on the basis of
relativistic mean field (RMF) theory. The corresponding time-odd fields, the
one-pion exchange currents, and the first- and second-order corrections are
taken into account. The present relativistic results reproduce the data well.
The relative deviation between theory and experiment for these four nuclei is
6.1% for the relativistic calculations and somewhat smaller than the value of
13.2% found in earlier non-relativistic investigations. It turns out that the
meson is important for the description of magnetic moments, first by
means of one-pion exchange currents and second by the residual interaction
provided by the exchange.Comment: 11 pages, 7 figure
Metamagnetic Transition in NaCoO Single Crystals
We report the magnetization, specific heat and transport measurements of high
quality NaCoO single crystals in applied magnetic fields up to
14T. In high temperatures, the system is in a paramagnetic phase. It undergoes
a magnetic phase transition below about 20K. When the field is applied along
the c-axis, the measurement data of magnetization, specific heat and
magnetoresistance reveal a metamagnetic transition from an antiferromagnetic
state to a quasi-ferromagnetic state at about 8T in low temperatures. However,
no transition is observed in the magnetization measurements up to 14T when the
field is applied perpendicular to the c-axis. The low temperature magnetic
phase diagram of NaCoO is determined.Comment: 4 pages, 5 figure
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