Surface Tension vs Interfacial Tension. Both surface tension and interfacial tension are effects based on liquids. Both these effects take place due to the unbalanced intermolecular forces between the liquid or solutions molecules.
Statistical process control (SPC) is a method of quality control which employs statistical methods to monitor and control a process. This helps ensure the process operates efficiently, producing more specification-conforming product with less waste (rework or scrap).
SPC is one of the three categories of Statistical Quality Control (SQC). SQC is a statistical method of analyzing variations in the manufacturing process in order to make it better and more effective. Only a certain number of samples are needed to determine whether the products are acceptable.