With more education and experience, accountants can become certified. Some financial documents, such as those submitted to the Securities and Exchange Commission, must be signed by a Certified Public Accountant.
Hyperchromicity is the increase of absorbance (optical density) of a material. The most famous example is the hyperchromicity of DNA that occurs when the DNA duplex is denatured. The UV absorption is increased when the two single DNA strands are being separated, either by heat or by addition of denaturant or by increasing the pH level.
Germicidal ultraviolet (UVC) used for UV disinfection inactivates microorganisms by disrupting their cellular membranes and by damaging their DNA or RNA. The UV light initiates a reaction between two molecules of thymine, one of the bases that make up DNA. UV light at 253.7nm wavelength (germicidal UV or UVC) causes adjacent thymine molecules on DNA to dimerize. The thymine dimer is very stable.