Table 5.
Experimental variables and their levels in Box–Behnken design.
| Factor | Level | ||
|---|---|---|---|
| Low (−1) | Central (0) | High (1) | |
| A: Ethanol concentration (%) | 60 | 70 | 80 |
| B: The ratio of liquor to material (mL/g) | 10 | 20 | 30 |
| C: Extraction time (min) | 20 | 30 | 40 |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.