For piping assemblies, screwed fittings cannot be used for: (a) galvanised piping as corrosion may develop around the threaded section (b) high flow applications as turbulence may be initiated at the threaded section (c) sections that have to be dismantled for maintenance (d) low pressure applications as the depth of the pipe thread reduces the pressure rating of the pipe.

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.

About 3% of the water on earth is freshest. only about 40% of that freshwater is available for human use. why is so much freshwater unavailable for human use?

Identify the correct mole ratio for each substance. sodium chloride (nacl) na: cl = 1: ammonium nitrate (nhno) h: o = 4: