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 $\lambda$. Varying systematically the pressure for different values of $\lambda$ 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

Recent breeding records of storks in Eastern Africa

Volume: XXVI

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