| Share | Phrase |
|---|
| 23.23% | reducing [physical/chemical] agent |
| 18.57% | reducing [physical/chemical] valve |
| 9.97% | reducing [physical/chemical] atmosphere |
| 7.07% | reducing [physical/chemical] unit |
| 7.01% | reducing [physical/chemical] gear |
| 6.14% | reducing [physical/chemical] catalyst |
| 3.86% | reducing [physical/chemical] operation |
| 3.11% | reducing [physical/chemical] mechanism |
| 2.75% | reducing [physical/chemical] device |
| 2.60% | reducing [physical/chemical] means |
| 2.50% | reducing [physical/chemical] bore |
| 2.04% | reducing [physical/chemical] signal |
| 1.87% | reducing [physical/chemical] rate |
| 1.54% | reducing [physical/chemical] converter |
| 1.47% | reducing [physical/chemical] tank |
| 1.42% | reducing [physical/chemical] gas |
| 1.33% | reducing [physical/chemical] mode |
| 1.33% | reducing [physical/chemical] portion |
| 1.13% | reducing [physical/chemical] compound |
| 0.98% | reducing [physical/chemical] effect |