Coronavirus Coronavirus Coronaviruses are species of virus belonging to the subfamily "Coronavirinae" in the family "Coronaviridae", in the order Nidovirales. Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome and with a nucleocapsid of helical symmetry. The genomic size of coronaviruses ranges from approximately 26 to 32 kilobases, the largest for an RNA virus. The name "coronavirus" is derived from the Latin "corona", meaning crown or halo, and refers to the characteristic appearance of virions under electron microscopy (E.M.) with a fringe of large, bulbous surface projections creating an image reminiscent of a royal crown or of the solar corona.
Electrical discharge machining of time between sparks. A longer off time, for example, allows the flushing of dielectric fluid through a nozzle to clean out the eroded debris, thereby avoiding a short circuit. These settings can be maintained in microseconds. The typical part geometry is a complex 3D shape, often with small or odd shaped angles. Vertical, orbital, vectorial, directional, helical, conical, rotational, spin and indexing machining cycles are also used. In "wire electrical discharge machining" (WEDM), also known as "wire-cut EDM" and "wire cutting", a thin single-strand metal wire, usually brass, is fed through the workpiece, submerged in a tank of dielectric