 AD stands for ANNO DOMINI which refers to Christ's birth. BC is before Christ. CE stands for 'Common Era' and is a recent term. It is used in place of AD.   BCD stand â¦ s for 'Before Common Day' and is used instead of BC, however it is more commonly represented as BCE, 'Before Common Era'.
Chemical engineers typically do the following: 1  Conduct research to develop new and improved manufacturing processes. 2  Develop safety procedures for those working with dangerous chemicals. 3  Develop processes for separating components of liquids and gases, or for generating electrical currents, by using controlled chemical processes.
Nanotechnology is another growing field where chemical engineers work. This could be anything from using nanoparticles to purify contaminated groundwater, to working with DNA for gene or stem cell therapies. These are just a few of the most common examples of what a chemical engineer may do for a career.