Mathematics 64 Plasma (Ionized gases) 64 Finite groups 39 Groups-- Algebra-- Mathematics 32 Finite element method 30 Differential equations-- Analysis-- Mathematics 15 Dissertations, Academic (Ph.D) 15 Chemistry 13 Ionized gases 13 Physical chemistry 13 Catalysis 12 Engineering 12 Ionisation 12 Physics 12 Ionizing radiation 11 Finite fields (Algebra) 10 Plasma physics; Properties of matter 10 Radiation 10 Data processing 9 Isotopes 9 Numerical solutions 9 History 8 Ionic solutions 8 Numerical analysis 8 Social sciences 8 Arts 7 Calculus 7 Group theory 7 Lecture Notes in Mathematics 7 Photo chemistry 7