Compact toroid concepts are generally less well developed than those of toroidal machines. They often have toroidal ferrite cores. The term "toroid" is also used to describe a toroidal polyhedron. The shape often used is a toroidal or doughnut-shaped ferrite core. They have solved numerous problems which exhibit circular cylindrical symmetry employing the toroidal functions. It is the first tokamak to employ superconducting toroidal and poloidal magnets. For an elastic, isotropic, homogeneous sphere, spheroidal, toroidal and radial (or breathing) modes arise. A drawback of toroidal transformer construction is the higher labor cost of winding. The 18 toroidal field coils will also use niobium-tin. It covered the oscillatory exchange of energy between toroidal and poloidal solar magnetic field ingredients. This rotation moves the fluid around the bubble creating a toroidal vortex. This figure shows the half section of a toroidal transformer. Scattering albedo equations have yet to be determined in elliptical, toroidal, conical and many others. For toroidal polyhedra, this manifold is an orientable surface. This corresponds to a negative toroidal energy density symmetric to the "x"-axis.