Factors | Name | Unit | Experimental value | ||||
---|---|---|---|---|---|---|---|
− 2 | − 1 | 0 | + 1 | + 2 | |||
X 1 | pH | – | 5.75 | 6.50 | 7.25 | 8.00 | 8.75 |
X 2 | Temperature | °C | 0.00 | 10.00 | 20.00 | 30.00 | 40.00 |
X 3 | Diesel concentration | % (v/v) | − 0.50a | 1.00 | 2.50 | 4.00 | 5.50 |
X 4 | NaCl concentration | % (w/v) | − 1.00a | 0.00 | 1.00 | 2.00 | 3.00 |