QD Chemistry TP Chemical technology 19 Q Science (General) 13 Extraction (Chemistry) 6 QC Physics 4 Laboratories. General works 3 Organic chemistry 3 TD Environmental technology. Sanitary engineering 3 Analytical chemistry 2 Quantitative analysis 2 Schiff bases 2 TA Engineering (General). Civil engineering (General) 2 Adsorption 1 Antibacterial agents 1 Clinical pathology. Laboratory technique 1 Electrochemical analysis 1 Food processing and manufacture 1 Fuel 1 GE Environmental Sciences 1 Indexes (General) 1 Inorganic chemistry 1 Medicinal plants (Culture only) 1 Methane 1 Microbial ecology 1 Optics. Light 1 Oxidation 1 Physical and theoretical chemistry 1 Polyvinyl chloride. Vinyl polymers 1 QA76 Computer software 1 QE Geology 1