| Gap ID | Area researched | Researchers and areas that they have investigated | |||||||||
| Bokor | Butler | Cummings | Gormley | Gauley | Lillywhite | Littlewood | PERC | Swaffield | Wakelin | ||
| 1.0 | Forces on solids | ü | ü |
|
|
|
| ü |
| ü | ü |
| 2.0 | Influence of TP |
|
| ü |
|
|
| ü | ü |
|
|
| 3.0 | LSTD |
| ü |
|
|
|
| ü |
| ü |
|
| 4.0 | WC usage behaviour |
| ü |
|
|
| ü |
|
| ü |
|
| 5.0 | WC type |
|
|
|
|
|
|
|
| ü |
|
| 6.0 | WC flush volume |
|
|
|
|
|
| ü |
| ü |
|
| 7.0 | Pipe configuration |
|
|
|
|
|
|
|
| ü |
|
| 8.0 | Pipe dimensions | ü | ü | ü | ü | ü | ü | ü | ü | ü | ü |
| 9.0 | Pipes (non-circular) |
|
|
|
|
|
|
|
| ü |
|
| 10.0 | Pipe gradient | ü | ü | ü | ü | ü | ü | ü | ü | ü | ü |
| 11.0 | Simulated faeces | ü |
|
|
| ü |
|
| ü | ü |
|
| 12.0 | Faeces degradation |
| ü |
|
|
|
|
|
|
|
|