Fully automated photocolorimetric method for dissolved silica in oil well water rich in sulfide and bicarbonate.
A fully automated photocolorimetric method for dissolved silica in oil well water rich in sulfide and bicarbonate is proposed; the method is based on yellow silicomolybdic heteropolyacid. To eliminate the interference of sulfide a treatment with bromate is utilized. The analytical range is 1-30 mg L(-1); with the automatically performed dilution it extends up to 300 mg L(-1), RSD 5.5%.
Fundamental principles of titrations with potassium bromate
Abstract Based on the results of researches into the chemistry and analytical uses of interhalogen compounds and of halogen ions of one positive charge, the fundamental principles of bromatometry are discussed by the authors. It is pointed out that in redox titrations with potassium bromate, in place of bromate or bromic acid, actually elementary bromine, or bromine chloride, or bromine chloride and elementary chlorine act as agents. Thus, bromine and bromine chloride form a complex with the halide content (bromide and chloride, respectively) of the solution to be titrated. The redox potential and polarity (electrophilic nature) of this complex can be controlled by varying the halide concentration. By clearing up the fundamental principles it has been possible to determine precisely the optimum experimental conditions of the various bromatometric procedures.
Role of the coronoid process in varus osteoarticular stability of the elbow.
The role of the coronoid process in varus osteoarticular stability of the elbow was investigated in 10 cadaveric elbows. Testing was performed at multiple flexion angles after incremental removal of the coronoid. At each flexion angle, removal of more than 50% of the coronoid produced a statistically significant decrease in the load resisting varus displacement compared with all lesser resection levels (P < .003). There was a trend for decreasing load after removal of 50% of the coronoid. The mean decrease in load across all flexion angles was 10.1%, 50.4%, and 75.4% after removal of 50%, 75%, and 100% of the coronoid, respectively. Resistance to varus displacement tended to decrease more as a percent of control at lower flexion angles than at higher flexion angles after removal of more than 50% of the coronoid. The coronoid process was found to be a key varus stabilizer in the elbow and may contribute more to elbow stability in extension than in flexion.