TJ Mechanical engineering and machinery TS Manufactures 41 Mechanics applied to machinery. Dynamics 31 Machine design and drawing 28 VM Naval architecture. Shipbuilding. Marine engineering 21 T Technology (General) 20 TL Motor vehicles. Aeronautics. Astronautics 14 Machine construction (General) 12 Engineering machinery, tools, and implements 11 Aeronautics. Aeronautical engineering 8 Engineering mathematics. Engineering analysis 8 Finite element method 8 QA Mathematics 8 TK Electrical engineering. Electronics Nuclear engineering 8 Mechanical and electrical engineering combined 7 TP Chemical technology 7 HD Industries. Land use. Labor 6 HE Transportation and Communications 5 Heat engines 5 Mechanical movements 5 TD Environmental technology. Sanitary engineering 5 HD28 Management. Industrial Management 4 Materials of engineering and construction 4 Mechanics of engineering. Applied mechanics 4 Mechanics of flight: Aerodynamics 4 Metal manufactures. Metalworking 4 Welding 4 Biotechnology 3 Control engineering systems. Automatic machinery (General) 3 GE Environmental Sciences 3