Research & information: general 22 Technology: general issues 19 Optical physics 17 History of engineering & technology 16 Condensed matter physics (liquid state & solid state physics) 5 Medicine 5 Applied optics 4 Materials science 4 Nanotechnology 4 Other technologies & applied sciences 4 Particle & high-energy physics 4 Biology, life sciences 3 Electrical engineering 3 Spectrum analysis, spectrochemistry, mass spectrometry 3 Circuits & components 2 Computer modelling & simulation 2 Energy industries & utilities 2 Science: general issues 2 Alternative & renewable energy sources & technology 1 Atomic & molecular physics 1 Biotechnology 1 Cellular biology (cytology) 1 Chemistry 1 Computer vision 1 Dermatology 1 Endocrinology 1 Energy technology & engineering 1 Environmentally-friendly architecture & design 1 Fluid mechanics 1 Food manufacturing & related industries 1