Transfer of molybdenum disulfide to various metals

Sliding friction experiments were conducted with molybdenum disulfide single crystals in contact with sputter cleaned surfaces of copper, nickel, gold, and 304 stainless steel. Transfer of the molybdenum disulfide to the metals was monitored with Auger electron spectroscopy. Results of the investigation indicate molybdenum disulfide transfers to all clean metal surfaces after a single pass over the metal surface with film thickness observed to increase with repeated passes over the same surfaces. Large particle transfer occurs when the orientation of the crystallites is other than basal. This is frequently accompanied by abrasion of the metal. Adhesion of molybdenum disulfide films occurred readily to copper and nickel, less readily to 304 stainless steel, and even less effectively to the gold, which indicates a chemical effect

Chemical sealing of small earth dams using sodium tripolyphosphate

As the seepage rate of 3.1 mm/d was considered too high, sodium tripolyphosphate (STPP) was dissolved in the dam water in an attempt to disperse the clay and reduce the hydraulic conductivity. Application of STPP altered the original sealing layer at first and, as seepage progressed, a new seal started to form at a depth of 0.8 m below the batter. The seepage rate was reduced to 0.39 mm/d and the hydraulic conductivity of this new seal was 2.0 x 10-9 m/s