While most stepped spillway design guidelines were developed for uniform step heights, a nonuniform stepped design might be a practical alternative in some cases. A physical study was conducted in a moderate slope stepped chute (1V:2H) and five stepped configurations were tested for 0.7 < dc/h < 1.9. Detailed air-water flow measurements were performed for each configuration and the results were...

The application of tracer techniques to the sugar industry is reviewed. This includes the investigation of residence time distribution in clarifiers, evaporators, continuous pans, crystallizers and fluidized bed dryers; the flow split in diffusers and evaporator vessels; leak detection; measurement of entrainment in vacuum pans and determination of system volumes such as cooling water ponds.

Nitrate determination in waters is generally carried out with cadmium filings and carcinogenic reagents or by reaction with phenolic compounds in highly concentrated sulfuric acid medium. In this work, it was developed a green analytical procedure for nitrate determination in natural waters based on direct spectrophotometric measurements in ultraviolet, using a flow-injection system with an ani...

An automatic microgravimetric screening system based on piezoelectric detection and the use of acidic stannous chloride as reductant was developed for the fast detection and determination of total mercury in water. Reduced mercury is detected as an amalgam by using a gold-coated piezoelectric crystal, the sensor subsequently being regenerated by passing it through a peroxydisulfate solution. Th...

A rapid and sensitive method using pressure-assisted electrokinetic injection (PAEKI) as the on-line sample enrichment technique and electrospray-tandem mass spectrometry as the monitor has been developed for the determination of four halogenated phenols, 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2,3,4,6-tetrachlorophenol and tetrabromobisphenol A, in water samples. In 8-min of injection, the ...