The density of states of a Bose-condensed gas confined in a harmonic trap is investigated. The predictions of Bogoliubov theory are compared with the ones of Hartree-Fock theory and of the hydrodynamic model. We show that the Hartree-Fock scheme provides an excellent description of the excitation spectrum in a wide range of energy, revealing a major role played by single-particle excitations in...

We study many-particle diffusion in 2D colloidal suspensions with full hydrodynamic interactions through a novel mesoscopic simulation technique. We focus on the behaviour of the effective scaled tracer and collective-diffusion coefficients DT(rho)/D0 and DC(rho)/D0 respectively, where D0 is the single-particle diffusion coefficient, as a function of the density of the colloids rho. At low Schm...

This paper describes an improved microfluidic device that enables hydrodynamic particle concentration and size-dependent separation to be carried out in a continuous manner. In our previous study, a method for hydrodynamic filtration and sorting of particles was proposed using a microchannel having multiple branch points and side channels, and it was applied for continuous concentration and sep...

We investigate diffusion-limited reactions between a diffusing particle and a target site on a semiflexible polymer, a key factor determining the kinetics of DNA-protein binding and polymerization of cytoskeletal filaments. Our theory focuses on two competing effects: polymer shape fluctuations, which speed up association, and the hydrodynamic coupling between the diffusing particle and the cha...

Dissipative particle dynamics is a relatively new technique for simulating fluid flow at meso scales that is more computationally efficient but at the same time able to reproduce some of the detail of molecular dynamics simulations. This report gives an introduction to the background of the technique, along with examples of applications in the fields of microfluidics, hydrodynamic behaviour at ...

Using the techniques of optical microscopy and particle tracking, we measure the pair correlation function and Brownian diffusion in monolayers of strongly interacting colloidal particles suspended at or near three different interfaces and test the universal scaling law of the normalized diffusion coefficient, D[over ˜]≃e(αΔS), as a function of the excess entropy ΔS for a wide range of particle...

The virial expansion of the collective mobility ~sedimentation! coefficient is considered for hard sphere suspensions at equilibrium. The term of the second order in volume fraction, which involves three-particle hydrodynamic interactions, is calculated with high accuracy. To achieve that we represent the collective mobility coefficient as the sum of convergent integrals over particle configura...

Particle-particle interactions in sedimenting systems have been investigated in the present study considering the many-body hydrodynamic and electrodynamic interactions. These interactions primarily occur in two modes: near-field and far-field interactions. The hydrodynamic interactions are modeled employing the Stokesian Dynamics while the electrodynamic interactions are accounted using the gr...

We develop theory and computational methods to investigate particle inclusions embedded within curved lipid bilayer membranes. We consider the case of spherical lipid vesicles where inclusion particles are coupled through (i) intramembrane hydrodynamics, (ii) traction stresses with the external and trapped solvent fluid, and (iii) intermonolayer slip between the two leaflets of the bilayer. We ...

A radial stagnation-point flow cell utilizing an optical microscope and an image-capturing device was used to directly observe the deposition kinetics of colloidal particles onto micropatterned glass surfaces with well-defined surface charge features. Surface charge heterogeneity was microfabricated onto glass surfaces by silanizing specified regions of the glass surface by a soft lithographic ...