ABSTRACT
The karst depression with a natural negative landform is favorable for reservoir construction with less excavation work. The underground air-water pressure would be complicated after the construction of a reservoir that blocks the natural air-water channel (sinkhole, karst channel, etc.). To develop a monitoring system for the reservoir, a large-scale laboratory simulation test was carried out to study the air-pressure evolution and water migration process during water table fluctuation after the blockage of the sinkhole in a karst depression. The results are as follows. (1) The positive pressure jacking effect and the negative pressure sucking effect were observed in the karst channel and inside the model during groundwater table fluctuation. (2) A water imbibition test on the rock-like material was carried out with layered resistivity and layered NMR measurement. The relationship of resistivity and water saturation was developed based on Archie's equation. (3) The resistivity evolution during the test was monitored using the high-density electronic resistivity imaging method. The resistivity of the measured profile was sensitive to the variation of the water level, and the water migration process was quantified by the resistivity to water saturation conversion. (4) The suitability of many techniques for monitoring a reservoir built on the karst depression was discussed. The resistivity monitoring technique combined with the air-water pressure monitoring technique could provide useful information for safety and reliability assessment.
ABSTRACT
The combination of mixed-mode chromatography (MMC) and molecular imprinting technology (MIT) has been proven to be successful for protein separation, but suffered from cumbersome material preparation and limited performance. In this work, a new modification method marrying atom transfer radical polymerization (ATRP) and multicomponent reaction was proposed to simplify the preparation process. Using regenerated cellulose (RC) membrane as the substrate, immunoglobulin G (IgG) as the template protein and tryptamine as the ligand, a dual-recognition membrane adsorbers (MIM) was prepared by mild Ugi four-component reaction (Ugi-4CR) and surface initiated ATRP. Control the ATRP time is the key for surface imprinting. The static IgG uptake and selectivity of UGI membrane were 45 mg/mL and 1.8, respectively, while those of MIM-0.5 were 42.5 mg/mL and 14, indicating that the introduction of molecular imprinting technology significantly improved the selectivity of the membrane to IgG. The MIM-0.5 membrane retains the pH-dependent and salt-tolerant of HCIC. The dynamic flow-through results showed that the MIM-0.5 membrane could effectively separate IgG from IgG/BSA mixed solution with the purity of 88% and retained its bioactivity. This work demonstrated the feasibility of bonding HCIC and MIT to the membrane surface by Ugi-4CR and ATRP.
