Origin of STMClassical Latin Sacrae Theologiae Magister Master of Sacred Theology
The electrical equivalent of the Synchronous Digital Hierarchy (SDH) optical signal, according to ITU-T international standards. The STM is known as Synchronous Transport Signal (STS) in Synchronous Optical Network (SONET) terminology, according to North American standards.The signal begins in electrical format as three T3 signals plus SDH signaling and control overhead and converts to optical format for transmission over the SDH optical fiber facilities. Each STM-1 frame is transmitted in 125
(Scanning Tunneling Microscope) A microscope that can image down to the atomic level. An STM uses a piezoelectric tube with a tiny sharp tip at the end that is moved within nanometers of the object being sampled. As it gets close, the voltage applied to the tip causes a "tunneling" current to flow to the object. As the tip is moved and bumps into an obstruction, the current changes. In order to maintain a certain constant current, the tip is raised and lowered accordingly, and this movement pattern is magnified and displayed on screen. See AFM, microscopy and nanotechnology.