| 204 / | HD | CHEMISTRY: ELECTRICAL AND WAVE ENERGY |
| * | DD | PROCESSES AND PRODUCTS {7} |
| 450 | DF | .~ Electrophoresis or electro-osmosis processes and electrolyte compositions therefor when not provided for elsewhere {14} |
| 518 | DF | .~.~ Barrier separation (e.g., using membrane, filter paper, etc.) {5} |
| 520 | DF | .~.~.~ Ion selective {8} |
| 522 | DF | .~.~.~.~ Using both anion and cation selective membranes {4} |
| 523 | DF | .~.~.~.~.~ Alternating anion and cation selective membranes {8} |
| 526 | | .~.~.~.~.~.~ Gas or vapor treated |