 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.
Chemical engineers can change the world. Chemical engineers work to improve the quality of people's lives. Most items used by people everyday have needed chemical engineers to produce them. Chemical engineers are helping to end starvation, disease and poverty. They are working to save the environment by developing alternative technologies to combat acid rain, lead pollution and the greenhouse effect.