Wingless locust nymphs can form massive migratory groups known as bands, whose coordinated movement results from local interactions. We analysed the spatial distribution of locusts within naturally occurring bands and compared them with computer simulations to infer which interaction rules are used by individuals. We found that the empirical radial distribution of neighbours around a focal indi...

To one double-breaker model, experimental investigation on blow open force was carried out. It demonstrates that the ratio between the emerging blow open force and arc power FB/ui decreases with the arcing time, the contact gap has less effect on FB/ui, and the characteristics of the blow open force are similar when the peak value of the short circuit current is beyond 4 kA. Then, according to ...

Submitted for the MAR05 Meeting of The American Physical Society Superfluidity of interacting bosons in one-dimension via strong disorder NOAH BRAY-ALI, UC Berkeley, Physics Department, JOEL MOORE, UC Berkeley, Physics Department; Lawrence Berkeley National Laboratory, Materials Science Division — We have found a novel set of superfluid and Mott insulating phases arising in strongly-disordered,...

We discuss the peculiarities of structure interface between a metal and stable colloidal dispersion charged nanoparticles in an electrolyte. It is demonstrated that quasi-2D ionic elevated density arises its vicinity due to effect electrostatic image forces. The stabilized particles, being electroneutral spatially distributed objects bulk electrolyte approaching interface, are attracted it. In ...

Computer simulations and theory are used to systematically investigate how the effective force between two big colloidal spheres in a sea of small spheres depends on the basic (big-small and small-small) interactions. The latter are modeled as hardcore pair potentials with a Yukawa tail which can be either repulsive or attractive. For a repulsive small-small interaction, the effective force fol...

The interaction forces between nanoscale colloidal particles coated with end-grafted Lennard-Jones homopolymers are calculated using off-lattice Monte Carlo simulations in the NVT ensemble. The focus of this work is on grafted polymers that are of approximately the same size as the nanoparticle, a regime intermediate to the star-polymer and Derjaguin limits. The effects of chain length (N), nan...

The forces between colloidal particles at a decane-water interface, in the presence of low concentrations of a monovalent salt (NaCl) and the surfactant sodium dodecyl sulfate (SDS) in the aqueous subphase, have been studied using laser tweezers. In the absence of electrolyte and surfactant, particle interactions exhibit a long-range repulsion, yet the variation of the interaction for different...

One of the most interesting phenomena in the soft-matter realm consists in the spontaneous formation of super-molecular structures (microphases) in condition of thermodynamic equilibrium. A simple mechanism responsible for this self-organization or pattern formation is based on the competition between attractive and repulsive forces with different length scales in the microscopic potential, typ...

We explore two-dimensional self-assembly of tobacco mosaic viruses (TMVs) on a substrate-supported, fluid lipid monolayer by manipulating the electrostatic interactions, with specific focus on the effects of the cationic lipid concentration in the monolayer and the presence of Ca(2+) ions in the surrounding bulk solution. The TMV assemblies were characterized by grazing-incidence X-ray scatteri...

During the last ten years, we have developed a new experimental technique called Total Internal Reflection Microscopy. Using TIRM we can monitor the separation distance between a single microscopic sphere immersed in an aqueous solution and a transparent plate. Because the distance is calculated from the intensity of light scattered by the sphere (3 to 30 microns in diameter) when illuminated b...