A midnight dumper discharges a truck load of industrial waste in a gravel pit. Three days after the truck is spotted, a sample of the remaining pool of pure waste is collected and is sent to laboratory for forensic analyses. Test results indicate that sample has a BODs of 80 mg/L O2 with a rate constant of 0.1/day. Three nearby factories generate organic wastes: a winery (ultimate BOD = 275 mg/L 02), a vinegar manufacturer (ultimate BOD 80 mg/L O2) and a pharmaceutical company (ultimate BOD -200 mg/L 02). You are the team of forensic experts here: Determine the source of waste.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length