Figure 1:
Figure 2:
Figure 3:
Figure 4:
Test sample water content test_
| Numbering | 1 | 1.39 | 3 |
|---|---|---|---|
| Aluminum box weight (g) | 17.05 | 2 | 17.56 |
| Box + wet soil mass (g) | 30.54 | 17.22 | 39.10 |
| Box + drying soil mass (g) | 30.34 | 30.54 | 38.82 |
| Mass of water (g) | 0.20 | 30.36 | 0.28 |
| Dry soil mass (g) | 13.29 | 0.18 | 21.26 |
| Moisture content (%) | 1.5 | 13.14 | 1.32 |
| Average moisture content (%) | 1.36 |
Comparison of the error between the actual water pressure value and the measured water pressure value_
| Sensor number | Measured water pressure (kPa) | Measured value of pore water pressure (kPa) | Measured accuracy (%) |
|---|---|---|---|
| 1# | 1.39 | 1.35 | −0.20 |
| 2# | 1.39 | 1.42 | +0.15 |
| 3# | 1.39 | 1.43 | +0.20 |
| 4# | 2.23 | 2.2 | −0.15 |
| 5# | 2.23 | 2.25 | +0.10 |
| 6# | 2.23 | 2.28 | +0.25 |
| 9# | 1.14 | 1.12 | −0.10 |
| 10# | 1.14 | 1.1 | −0.20 |
| 11# | 1.14 | 1.18 | +0.20 |
Comparison of several short-range wireless technologies_
| Technical standard | Bluetooth | Wi-Fi | Mobile communications | ZigBee |
|---|---|---|---|---|
| Working frequency | 2.4 GHz | 2.4 GHz | 0.8/0.9 GHz | 868 MHz/915 MHz/2.4 GHz |
| Coverage | 10 m | 100–200 m | Depends on network | 50–300 m |
| Transmission rate | 1 M/s | 11–54 M/s | 50k–2M | 10–250k |
| Power consumption | Big | Big | Small | Minimum |
| Cost | High | Low | Highest | Low |
| Delay | Short | Long | Shorter | Shorter |
| Confidentiality | Good | Better | Good | Good |
| Scalability | Difference | Good | Good | Good |
| Network capacity | Small | Big | Big | Big |
| Technical complexity | More complicated | Easy | Easy | Easy |
Content of RE ions in the leaching solution of magnesium sulfate leaching in each time period_
| Leaching liquid | Leaching time/h | RE weight collected in leaching solution (mg) | ||
|---|---|---|---|---|
| A1 | B1 | C1 | ||
| Magnesium sulfate | 1 | 0 | 0 | 0 |
| 2 | 1.51 | 2.24 | 1.15 | |
| 3 | 8.54 | 10.76 | 7.56 | |
| 4 | 38.25 | 42.47 | 38.69 | |
| 5 | 10.58 | 12.01 | 15.28 | |
| 6 | 5.47 | 3.76 | 6.89 | |
| 7 | 0.78 | 0.66 | 0.45 | |
| 8 | 0.12 | 0.1 | 0.1 | |
Content of RE ions in the leaching solution of clear water leaching in each time period_
| Leaching liquid | Leaching time/h | RE weight collected in leaching solution (mg) | ||
|---|---|---|---|---|
| A2 | B2 | C2 | ||
| Shimizu | 1 | 0 | 0 | 0 |
| 2 | 0 | 0 | 0 | |
| 3 | 0 | 0 | 0 | |
| 4 | 0 | 0 | 0 | |
| 5 | 0 | 0 | 0 | |
| 6 | 0 | 0 | 0 | |
| 7 | 0 | 0 | 0 | |
| 8 | 0 | 0 | 0 | |