TRAVISTRA

 SCANNING ELECTRON MICROSCOPE It is used for the surface characterization of materials. It produces images of a sample by scanning the surface with a focused beam of electrons. It provides information about topography(surface features), morphology (shape and size), composition, and crystallographic information. PRINCIPLE The electrons interact with the atoms in the sample, producing various signals that contain information about the surface topography and composition of the sample.  The accelerated electrons in an SEM carry significant amounts of kinetic energy, and this energy is dissipated as a variety of signals produced by electron sample interactions. Backscatter electrons are incidental electrons reflected backward which provide composition data related to element and compound detection. Diffracted backscatter electrons determine crystalline structures as well as the orientation of minerals and micro-fabric, X-rays emitted from beneath the sample surface, can provide ele...

 CATHODIC PROTECTION  It is a method of preventing a metallic object from corrosion. It is an electrochemical process in which the metal which is to be protected is forced to act as a cathode. Corrosion occurs only in the anodic area. Therefore the entire surface of the metal can be turned into a cathode, then corrosion can be prevented. In this case, corrosion is not actually eliminated but moved to a known location by adding an anode, which undergoes slow and controlled corrosion. There are two main methods of applying  cathodic protection: Sacrificial anode protection and Impressed current cathodic protection SACRIFICIAL ANODE PROTECTION In this method, the metallic structure which is to be protected is connected to a more anodic metal through a wire, so the entire corrosion is concentrated on the anodic metal, and the metallic structure is protected sacrificially. Anode metals commonly used for this are Mg, Zn, Al, and its alloys.   They are based on the position...