Yu Shao

Physical Modeling on Sand Erosion around Defective Sewer Pipes under the Influence of Groundwater

AbstractThis paper studies soil-erosion problem around cracked sewer pipes, which is usually associated with groundwater infiltration in sewer systems. Four factors (soil-particle size, defect size, water head, and soil height) that are associated with the erosion process were investigated experimentally. Two experimental setups were used: a cylindrical bin with a circular outlet at the bottom center to simulate the erosion process and a rectangular box with the outlet on the side wall to show the internal erosion process. The quantitative influences of the four factors on the erosion-void shape, volume, and length were analyzed. It is found that the geometry of the erosion void is determined by water head and soil height. Relationships were developed for calculating the water-discharge rate, sand-discharge rate, and erosion-void diameter.

Fabrication of a cross-linked supramolecular polymer on the basis of cucurbit[8]uril-based host–guest recognition with tunable AIE behaviors

A photoresponsive ternary host–guest molecular recognition motif between cucurbit[8]uril (CB[8]), the 1,1-dimethyl-4,4-bipyridinium dication (DMV2+) and an azobenzene derivative (trans-2) in water was applied in this paper to construct a cross-linked supramolecular polymer. Various characterization methods were adopted to prove the formation of the polymer, such as 1H NMR, DOSY, specific viscosity measurements, and fluorescence spectroscopy. Additionally, the tetraphenylethylene moiety was incorporated into this system and the aggregation induced emission (AIE) properties of the supramolecular polymer were also investigated.

Experimental Observations on the Initiation of Sand-Bed Erosion by an Upward Water Jet

AbstractErosion of a saturated sand bed by a vertically upward water jet was studied experimentally. Direct observations on the behavior of sand-bed erosion were obtained by increasing the flow rat...