Top IPC subclasses
1
|
C10G
|
5
|
cracking hydrocarbon oilsproduction of liquid hydrocarbon mixtures, e.g. by destructive hydrogenatio
|
2
|
G01N
|
4
|
Investigating or analysing materials by determining their chemical or physical properties
|
3
|
F02B
|
2
|
Internal-combustion piston engines; combustion engines in general
|
4
|
H04N
|
1
|
pictorial communication, e.g. television
|