3,341 research outputs found
Lane-formation vs. cluster-formation in two dimensional square-shoulder systems: A genetic algorithm approach
Introducing genetic algorithms as a reliable and efficient tool to find
ordered equilibrium structures, we predict minimum energy configurations of the
square shoulder system for different values of corona width . Varying
systematically the pressure for different values of we obtain
complete sequences of minimum energy configurations which provide a deeper
understanding of the system's strategies to arrange particles in an
energetically optimized fashion, leading to the competing self-assembly
scenarios of cluster-formation vs. lane-formation.Comment: 5 pages, 6 figure
Single-particle and collective slow dynamics of colloids in porous confinement
Using molecular dynamics simulations we study the slow dynamics of a hard
sphere fluid confined in a disordered porous matrix. The presence of both
discontinuous and continuous glass transitions as well as the complex interplay
between single-particle and collective dynamics are well captured by a recent
extension of mode-coupling theory for fluids in porous media. The degree of
universality of the mode-coupling theory predictions for related models of
colloids is studied by introducing size-disparity between fluid and matrix
particles, as well as softness in the interactions.Comment: 4 pages, 5 figures, minor revision
If It Pleases the Court, I Present Exhibit One: An Evidence-Based Law Collection Evaluation
Describes the evidence-based evaluation of a law collection supporting a paralegal program.
It applies the Koufogiannakis & Brettle\u27s Evidence Based Library and Information Practice (EBLIP) framework to review the law collection development evaluation process
Tailoring the Phonon Band Structure in Binary Colloidal Mixtures
We analyze the phonon spectra of periodic structures formed by
two-dimensional mixtures of dipolar colloidal particles. These mixtures display
an enormous variety of complex ordered configurations [J. Fornleitner {\it et
al.}, Soft Matter {\bf 4}, 480 (2008)], allowing for the systematic
investigation of the ensuing phonon spectra and the control of phononic gaps.
We show how the shape of the phonon bands and the number and width of the
phonon gaps can be controlled by changing the susceptibility ratio, the
concentration and the mass ratio between the two components.Comment: 4 pages 3 figure
Computer Assembly of Cluster-Forming Amphiphilic Dendrimers
Recent theoretical studies have predicted a new clustering mechanism for soft
matter particles that interact via a certain kind of purely repulsive, bounded
potentials. At sufficiently high densities, clusters of overlapping particles
are formed in the fluid, which upon further compression crystallize into cubic
lattices with density-independent lattice constants. In this work we show that
amphiphilic dendrimers are suitable colloids for the experimental realization
of this phenomenon. Thereby, we pave the way for the synthesis of such
macromolecules, which form the basis for a novel class of materials with
unusual properties.Comment: 4 pages, 4 figures, 1 tabl
Formation of Polymorphic Cluster Phases for Purely Repulsive Soft Spheres
We present results from density functional theory and computer simulations
that unambiguously predict the occurrence of first-order freezing transitions
for a large class of ultrasoft model systems into cluster crystals. The
clusters consist of fully overlapping particles and arise without the existence
of attractive forces. The number of particles participating in a cluster scales
linearly with density, therefore the crystals feature density-independent
lattice constants. Clustering is accompanied by polymorphic bcc-fcc
transitions, with fcc being the stable phase at high densities.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let
Posters, Programs, and Perspectives on Democracy
Kahl and Paterson provide an example of collaboration around a specific, one-time program that both units were interested in bringing to their university, in this case an art installation on the theme of democracy. Although the authors spearheaded the program, they tapped the expertise of colleagues in their units and across campus in order to accomplish their goals. Kahl and Paterson\u27s work also serves as an example of combining active programming, in this case three lectures by campus faculty, with passive programming, an approach where professionals create exhibits or educational displays in a centrally located venue for students and others to browse and absorb at their convenience
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