Table 5 The Plackett − Burman test scheme and results.
No. | Parameters | Repose angle θ/(°) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
CORO−O | CORO−p | COSO−O | COSO−p | CODO−O | CODO−p | NSCO−O | TSCO−O | NCSO−O | TCSO−O | |||
1 | 1 | 1 | 1 | −1 | −1 | −1 | 1 | −1 | 1 | 1 | 13.66 | |
2 | −1 | 1 | 1 | 1 | −1 | −1 | −1 | 1 | −1 | 1 | 16.64 | |
3 | −1 | −1 | −1 | 1 | −1 | 1 | 1 | −1 | 1 | 1 | 25.67 | |
4 | −1 | 1 | −1 | 1 | 1 | −1 | 1 | 1 | 1 | −1 | 33.56 | |
5 | 1 | −1 | −1 | −1 | 1 | −1 | 1 | 1 | −1 | 1 | 17.68 | |
6 | 1 | 1 | −1 | 1 | 1 | 1 | −1 | −1 | −1 | 1 | 36.52 | |
7 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | −1 | 9.56 | |
8 | 1 | 1 | −1 | −1 | −1 | 1 | −1 | 1 | 1 | −1 | 14.53 | |
9 | −1 | −1 | 1 | −1 | 1 | 1 | −1 | 1 | 1 | 1 | 12.86 | |
10 | 1 | −1 | 1 | 1 | 1 | −1 | −1 | −1 | 1 | −1 | 15.47 | |
11 | −1 | 1 | 1 | −1 | 1 | 1 | 1 | −1 | −1 | −1 | 20.89 | |
12 | 1 | −1 | 1 | 1 | −1 | 1 | 1 | 1 | −1 | −1 | 13.46 | |
