QC Physics 235 TK Electrical engineering. Electronics Nuclear engineering 198 Q Science (General) 61 TJ Mechanical engineering and machinery 61 TA Engineering (General). Civil engineering (General) 35 QD Chemistry 34 T Technology (General) 33 TP Chemical technology 32 Q Science 19 QA75 Electronic computers. Computer science 15 RE Ophthalmology 13 Optics. Light 11 General special. Including optical illusion and visual perception 8 QA76 Computer software 8 HE Transportation and Communications 7 Applied optics. Photonics 4 G70.212-70.215 Geographic information system 4 Spectroscopy 4 Unspecified 4 Detectors. Sensors. Sensor networks 3 Mechanical and electrical engineering combined 3 Mechanics applied to machinery. Dynamics 3 Neural networks (Computer science) 3 Optical fibers 3 Optical pattern recognition 3 Physical and theoretical chemistry 3 Physical optics 3 QH Natural history 3 RF Otorhinolaryngology 3 T Technology 3