| Structural model: | (english) An idealization for analysis purposes of a real or conceived structure. A structural model includes boundaries limiting the scope of the analysis. Supports occur at these boundaries, representing things which hold the structure in place. |
| Support: | (english) A support contributes to keeping a structure in place by restraining one or more degrees of freedom. In a structural model, supports represent boundary entities which are not included in the model itself, e.g., foundations, abutments, or the earth itself. For each restrained translation degree of freedom at a support, there is a corresponding reaction force; for each restrained rotation degree of freedom, there is a reaction moment. |
| Yield stress: | (english) A material loaded beyond its yield stress, no longer exhibits linear elastic behavior. Metals, particularly mild steel, generally have a very well defined yield stress compared to other materials. Yield stress is sometimes called yield strength. |
| Adsorption | (Environmental Engineering) A surface phenomena in which a solute (soluble material) concentrates or collects at a surface (the adsorbent). |
| Advanced wastewater treatment | (Environmental Engineering) The removal of any dissolved or suspended contaminants beyond secondary treatment, often this is the removal of the nutrients nitrogen and/or phosphorus. |
| Alcohol | (Environmental Engineering) An organic compound with one or more hydroxyl "-OH" groups. |
| Aldehyde | (Environmental Engineering) An organic compound with a carbonyl at one end of a hydrocarbon group. |
| Amine | (Environmental Engineering) A functional group consisting of "-NH2." |
| Amino acid | (Environmental Engineering) A functional group which consists of a carbon with a carboxylic acid, "-COOH" and an amine, "-NH2." These compounds are the building blocks for proteins. |
| Aromatic | (Environmental Engineering) A form of bonding in which ring compounds share electrons over more than two atoms. The electrons are delocalized. This leads to unusual ring stability. |