10,110 research outputs found
New Muslim Cool: Engaging Stakeholders in the Filmmaking Process
Provides an overview of the production, funding model, project partners, and impact of New Muslim Cool, a documentary film on American Muslim youth culture with a mission to promote interfaith dialogue. Discusses the role of social media outreach
Perturbed breakup of gas bubbles in water: Memory, gas flow, and coalescence
The pinch-off of an air bubble from an underwater nozzle ends in a
singularity with a remarkable sensitivity to a variety of perturbations. I
report on experiments that break both the axial (i.e., vertical) and azimuthal
symmetry of the singularity formation. The density of the inner gas influences
the axial asymmetry of the neck near pinch-off. For denser gases, flow through
the neck late in collapse changes the pinch-off dynamics. Gas density is also
implicated in the formation of satellite bubbles. The azimuthal shape
oscillations described by Schmidt et al., can be initiated by anisotropic
boundary conditions in the liquid as well as with an asymmetric nozzle shape. I
measure the n = 3 oscillatory mode, and observe the nonlinear, highly
three-dimensional outcomes of pinch-off with large azimuthal perturbations.
These are consistent with prior theory
An investigation of the interaction of N2O with the Si(111)-7 × 7 surface using AES and optical reflectometry; A comparison with O2
At 300 K, N2O decomposes into N2, leaving behind atomic oxygen at the Si(111)¿7 × 7 surface. Decomposition at two different sites is proposed, having the overall initial reaction probability: s(0) = (6.7 ± 0.7) × 106. SiOx(x not, vert, similar 1) bonds are predominantly formed, saturation occurring at monolayer coverage. This oxygen monolayer appears to completely prevent further oxygen uptake by additional N2O or O2 exposures, in contrast with the adsorption behaviour of O2 on Si(111)-7 × 7, which exhibits slow sorption beyond one monolayer
Effective One-Dimensional Models from Matrix Product States
In this paper we present a method for deriving effective one-dimensional
models based on the matrix product state formalism. It exploits translational
invariance to work directly in the thermodynamic limit. We show, how a
representation of the creation operator of single quasi-particles in both real
and momentum space can be extracted from the dispersion calculation. The method
is tested for the analytically solvable Ising model in a transverse magnetic
field. Properties of the matrix product representation of the creation operator
are discussed and validated by calculating the one-particle contribution to the
spectral weight. Results are also given for the ground state energy and the
dispersion.Comment: 17 pages, 8 figure
Comparison of 2D melting criteria in a colloidal system
We use super-paramagnetic spherical particles which are arranged in a
two-dimensional monolayer at a water/air interface to investigate the crystal
to liquid phase transition. According to the KTHNY theory a crystal melts in
thermal equilibrium by two continuous phase transitions into the isotropic
liquid state with an intermediate phase, commonly known as hexatic phase. We
verify the significance of several criteria based on dynamical and structural
properties to identify the crystal - hexatic and hexatic - isotropic liquid
phase transition for the same experimental data of the given setup. Those
criteria are the bond orientational correlation function, the Larson-Grier
criterion, 2D dynamic Lindemann parameter, the bond-orientational
susceptibility, the 2D Hansen-Verlet rule, the L\"{o}wen-Palberg-Simon
criterion as well as a criterion based on the shape factor of Voronoi cells and
Minkowski functionals. For our system with long range repulsion, the bond order
correlation function and bond order susceptibility works best to identify the
hexatic - isotropic liquid transition and the 2D dynamic Lindemann parameter
identifies unambiguously the hexatic - crystalline transition.Comment: 20 pages, 13 figure
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