Summary: In engineering, the transition from idea to product requires that the engineer produce clear proposals demonstrating the idea's practicality and economic feasibility. Smelser describes how writing is a key element in this process. Engineers don't need to know how to write.
Cradle to gate Cradle to gate is a boundary condition associated with embodied carbon, carbon footprint and LCA studies. A study to these boundaries considers all activities starting with the extraction of materials from the earth (the cradle), their transportation, refining, processing and fabrication activities until the material or product is ready to leave the factory gate.
Mantrap door systems are specialized doors used primarily for security purposes. Basically is is a small, enclosed vestibule with two sets of interlocking doors. Typically, one door cannot be opened without the other being shut or locked. Purpose. The main purpose of a mantrap door is security.