Carbocations are species bearing a formal + charge on carbon. The have sp2 hybridization and trigonal planar geometry, with an empty p orbital on carbon, perpendicular to the plane containing the substituents (see diagrams shown to the right).
Aortic cross-clamp. An aortic cross-clamp is a surgical instrument used in cardiac surgery to clamp the aorta and separate the systemic circulation from the outflow of the heart. An aortic cross-clamping procedure serves, for example, in the repairing of coarctation of the aorta.
Toggle Clamps. Toggle Clamps are ideal for use in a variety of situations, including jigs, bench holdfasts, and for specific production situations, where quick and easy repeatability is vital. The ends of each clamp have an adjustable rubber tip to control pressure sensitivity.