The adhesion of membranes is often governed by an interaction potential which exhibits a potential barrier at intermediate membrane separations. At low temperatures, the membranes are trapped by the barrier. As the temperature is increased, thermally-excited shape fluctuations act to reduce the strength of this barrier until the membranes undergo an unbinding transition. This transition is disc...

We have fabricated (Ga,Mn)As nanostructures in which domain walls can be pinned by sub-10 nm constrictions. Controlled by shape anisotropy, we can switch the regions on either side of the constriction to either parallel or antiparallel magnetization. All samples exhibit a positive magnetoresistance, consistent with domain-wall trapping. For metallic samples, we find a magnetoresistance up to 8%...

Evolutionary Algorithm (EA) is applied to a practical three-dimensional shape optimization for aerodynamic design of an aircraft wing. Aerodynamic performances of the design candidates are evaluated by using the three-dimensional compressive Navier-Stokes equations. A structural constraint is introduced to avoid an apparent solution of zero thickness wing for low drag in high speeds. To overcom...

Helicopters operations on board ships require special procedures introducing additional limitations known as ship helicopter operational limitations (SHOLs) which are a priority for all navies. This paper presents the main results obtained from the experimental investigation of a simple frigate shape (SFS) which is a typical case of study in experimental and computational aerodynamics. The resu...

Wind tunnel and water tank experiments were carried out on a penguin model in order to optimise the shape and attachment of a back-mounted datalogger. Device-induced turbulence was minimised when the unit was placed in the most caudal position. Drag was further reduced by shaping the device to match the body contour. The hydrodynamic resistance of the package could be reduced by 65 % compared w...

We report results from Monte Carlo simulations of systems of magnetic dipoles that relax through quantum tunneling, much as Fe8 crystals at very low temperature. For short times, a hole develops in suitably defined magnetic field pseudo–distributions, which matches the shape of the tunnel window (TW). Much later, ordinary field distributions P (h) develop similar holes if thermal energies are n...

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The most important practical characteristic of a Josephson junction is its critical current. The shape of the junction determines the specific form of the magnetic-field dependence of the its Josephson current. Here we address the magnetic diffraction patterns of specially shaped planar Josephson tunnel junctions. We focus on a wide ensemble of generalized ellipses, called superellipses, which ...

This paper describes the investigation of a DC surface corona discharge established on a rounded edge of a dielectric material. The ionic wind induced by the discharge was measured with the Particle Image Velocimetry system. A physical induced flow model is proposed to interpret the shape of the velocity field. Experiments on a flat plate and a NACA 0015 were performed in a subsonic wind tunnel...