Dark Stool: If your stool is black or bright red in color, it can mean that you are bleeding internally, as a possible result of an ulcer or cancer, and warrants a call to your doctor even if you think it could be hemorrhoids, or tiny tears in the anal tissue, due to constipation and straining.
The chemical reaction in which high molecular mass molecules are formed from monomers is known as polymerization. There are two basic types of polymerization, chain-reaction (or addition) and step-reaction (or condensation) polymerization.
Chemical vapor deposition (CVD) is a chemical process used to produce high quality, high-performance, solid materials.The process is often used in the semiconductor industry to produce thin films. Hybrid Physical-Chemical Vapor Deposition (HPCVD) â This process involves both chemical decomposition of precursor gas and vaporization of a solid source. 2  Metalorganic chemical vapor deposition (MOCVD) â This CVD process is based on metalorganic precursors.