 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 working in laboratories and offices typically work in industries including architectural, engineering-related services, basic chemical manufacturing and scientific research. This type of working environment means standard working hours with days starting between 8 and 9 a.m.