Comparative chronoamperometry: Spheres, discs, cylinders and bands

Gaussian curvature and the equilibrium among bilayer cylinders, spheres, and discs.

In mixtures of cetyltrimethylammonium bromide (CTAB) and sodium perfluorooctanoate (FC(7)) in aqueous solution, novel bilayer cylinders with hemispherical end caps and open, flat discs coexist with spherical unilamellar vesicles, apparently at equilibrium. Such equilibrium among bilayer cylinders, spheres, and discs is only possible for systems with a spontaneous curvature, R(o), and a positive...

Reflections on Spheres and Cylinders of Revolution

In computer graphics, it is often an advantage to calculate reflections directly, especially when the application is time-critical or when line graphics have to be displayed. We specify formulas and parametric equations for the reflection on spheres and cylinders of revolution. The manifold of all reflected rays is the normal congruence of an algebraic surface of order four. Their catacaustic s...

Dense packings of spheres in cylinders: simulations.

We study the optimal packing of hard spheres in an infinitely long cylinder, using simulated annealing, and compare our results with the analogous problem of packing disks on the unrolled surface of a cylinder. The densest structures are described and tabulated in detail up to D/d=2.873 (ratio of cylinder and sphere diameters). This extends previous computations into the range of structures whi...

Fast Distance Computation Between a Point and Cylinders, Cones, Line-Swept Spheres and Cone-Spheres

Non-equilibrium dissociating nitrogen flow over spheres and circular cylinders

Theoretical results based on the methods of Freeman and Garr & Marrone show that the stand-off distance and flow pattern of non-equilibrium dissociating flow of nitrogen over the front part of a blunt body can be correlated in terms of a single reaction rate parameter s2 taking account of parameters describing the speed, density, dissociation and temperature of the free stream. The density patt...