1 Subjects: “...closed-loop recycling...”

2 Subjects: “...closing the loop...”

3 Subjects: “...hardware-in-the-loop testing...”

4 Subjects: “...sensitivity loop...”

5 Subjects: “...coal-direct chemical looping combustion...”

6 Subjects: “...open-loop control systems...”

7 Subjects: “...causal loop diagram...”

8 Subjects: “...causal loop diagram...”

9 Subjects: “...closed-loop circulation...”

10 Subjects: “...closed material loops...”

11 Subjects: “...loop order analysis...”

12 Subjects: “...heat recovery loop (HRL)...”

13 Subjects: “...hysteresis loops...”