Top IPC subclasses
1
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C02F
|
23
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Treatment of water, waste water, sewage, or sludge
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2
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F17B
|
3
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gas-holders of variable capacity
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3
|
B01D
|
2
|
Separation
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4
|
C12F
|
2
|
recovery of by-products of fermented solutionsdenaturing of, or denatured, alcohol
|
5
|
A01G
|
1
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Horticulture; cultivation of vegetables, flowers, rice, fruit, vines, hops, or seaweed; forestry; watering
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