MDS 621.3229

Wording: Technology Engineering Applied physics Electrical, magnetic, optical, communications, computer engineering; electronics, lighting Lighting Lighting in specific situations Exterior lighting

Dewmoji: 💡🔩🏭????

0 Computer science, information & general works 252,013 ℹ️	1 Philosophy and Psychology 270,129 🧠	2 Religion 681,242 🙏	3 Social sciences 1,328,382 👫	4 Language 209,883 💬	5 Natural sciences & mathematics 431,918 🔬	6 Technology 940,635 💡	7 Arts & recreation 1,031,850 🎨	8 Literature & rhetoric 1,436,736 📚	9 History & geography 837,760 🗺️
60 Technology 9,943 💡	61 Medicine & health 306,082 💉	62 Engineering 157,979 🔩	63 Agriculture 88,093 🌱	64 Home economics & family management 172,237 🏠	65 Management & public relations 145,064 👔	66 Chemical engineering 19,470 🚀	67 Manufacturing 8,724 📦	68 Manufacture for specific uses 20,805 🔨	69 Construction of buildings 12,238 👷
620 Engineering and allied operations 21,480 🔩	621 Applied physics 47,082 🏭	622 Mining and related operations 3,895 🕳	623 Military and nautical engineering 15,890 ⚓	624 Civil engineering 8,105 🌉	625 Engineering of railroads and roads 6,655 🛤	626 [Formerly: Canal Engineering] 83	627 Hydraulic engineering 1,873 🌊	628 Environmental engineering and sanitary engineering 7,319 🚽	629 Other branches of engineering 45,597 🌿
621.0 1,207	621.1 Steam engineering 687	621.2 Hydraulic machinery 291	621.3 Electrical, magnetic, optical, communications, computer engineering; electronics, lighting 33,501	621.4 Heat engineering 4,105	621.5 Pneumatic machinery and Compressed air and Refrigeration and refrigerating machinery 454	621.6 Fans (Machinery) and Pumping machinery 161	621.7 Production engineering and Factories and Machine-shop practice 182	621.8 Machine Engineering 2,644	621.9 Machine-tools 1,518
621.30 Electric power plant 436	621.31 Generation, modification, storage, transmission of electric power 5,025	621.32 Lighting 393	621.33 Electric Railways 50	621.34 Magnets and Electromagnets 121	621.35 Batteries and Superconductivity 40	621.36 Optical engineering 2,905	621.37 Electrical Measurement Instruments 156	621.38 Electronics, communications engineering 20,091	621.39 Computer engineering 2,322
621.320 17	621.321 Principles of lighting 6	621.322 Lighting in specific situations 43	621.323 12	621.324 1	621.325	621.326 3	621.327 14	621.328 13	621.329 6
621.3220 2	621.3221	621.3222	621.3223	621.3224	621.3225 Interior lighting for public structures 5	621.3226 Interior lighting for buildings for religious and related purposes 1	621.3227 Interior lighting for buildings for educational and research purposes	621.3228 Interior lighting for residential and related buildings 5	621.3229 Exterior lighting 11