Screw be an appropriate choice. The left side pedal of a bicycle has a left-hand thread. More generally, screw may mean any helical device, such as a clamp, a micrometer, a ship's propeller, or an Archimedes' screw water pump. There is no universally accepted distinction between a screw and a bolt. A simple distinction that is often true, although not always, is that a bolt passes through a substrate and takes a nut on the other side, whereas a screw takes no nut because it threads directly into the substrate (a screw "screws into something", a bolt "bolts several things together").
GNU Archimedes of TCAD software, i.e. tools utilized to assist the development of technologically relevant products. In particular, this package assists engineers in designing and simulating submicron and mesoscopic semiconductor devices. In a next-future version Archimedes will also be able to simulate nanodevices, using the Wigner Monte Carlo formalism (an experimental release can be found at). Today Archimedes is used in several big companies for simulation and production purposes. Archimedes is also useful for teaching purposes since everybody can access the sources, modify and test them. Today, it is used for teaching courses in several hundreds universities all around the world. Furthermore,