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 due to eroded brass particles causing "brass on brass" wire breakage, therefore copper is recommended. Several manufacturers produce EDM machines for the specific purpose of removing broken tools (drill bits, taps, bolts and studs) from work pieces. In this application, the process is termed "metal disintegration machining" or MDM. The metal disintegration process removes only the center of the tap, bolt or stud leaving the hole intact and allowing a part to be reclaimed. Closed loop manufacturing can improve the accuracy and reduce the tool costs Advantages of EDM include machining of: Disadvantages of EDM include: Electrical discharge machining Electrical