Technology: general issues 20 History of engineering and technology 15 History of engineering & technology 9 discrete element method 9 Research & information: general 7 Discrete elements method 6 Finite difference method 4 Biology, life sciences 3 Deformation 3 Technology, engineering, agriculture 3 Aggregates 2 Biomedical engineering 2 Conservation of buildings and building materials 2 Materials science 2 Mechanics of solids 2 Reinforcement 2 Software testing 2 Soils 2 discrete element 2 discrete element modeling 2 Aggregate base 1 Air voids 1 Asia 1 Asia-Pacific Economic Cooperation 1 Asia-pacific economic cooperation 1 Asian Pacific Economic Cooperation Forum 1 Asphalt mixtures 1 Base material 1 Blast furnace hearth 1 Blast furnaces 1