Answer:
B only
Explanation:
Squeeze-type resistance spot welding (STRSW)is a type of electric resistance welding that brings about the weld on interfacing sheet metal pieces through which heat generated from electric resistance bring about fusion and welding of the two pieces together
Therefore, it is not meant for opening but joints but it can be used for making replacement spot welds adjacent to the original spot weld due to the smaller heat affected zone (HAZ) created by the STRSW process.
Acid mine drainage is the formation and movement of highly acidic water rich in heavy metals. This acidic water forms through the chemical reaction of surface water (rainwater, snowmelt, pond water) and shallow subsurface water with rocks that contain sulfur-bearing minerals, resulting in sulfuric acid.
Answer:
Both Technician A and B are correct
Explanation:
Methanol is used in internal combustion engines. However, the use of methanol in internal combustion engines has decreased lately even though it was thought to lead to cleaner emissions than gasoline. Methanol internal combustion engines produce formaldehyde which is also an environmental pollutant. Also, the cost of methanol is slightly higher than that of good quality gasoline.
MTBE replaced tetraethyllead as a gasoline additive because the former lead to the emission of particulate lead from automobile exhausts which is a serious environmental pollutant. The use of MTBE has declined over the years due to environmental concerns. It has been banned because it has been found to be a significant groundwater pollutant if gasoline containing MTBE is spilled or leaked at gas stations.
Answer:
The required pumping head is 1344.55 m and the pumping power is 236.96 kW
Explanation:
The energy equation is equal to:
For the pipe 1, the flow velocity is:
Q = 18 L/s = 0.018 m³/s
D = 6 cm = 0.06 m
The Reynold´s number is:
Using the graph of Moody, I will select the f value at 0.0043 and 335339.4, as 0.02941
The head of pipe 1 is:
For the pipe 2, the flow velocity is:
The Reynold´s number is:
The head of pipe 1 is:
The total head is:
hi = 1326.18 + 21.3 = 1347.48 m
The required pump head is:
The required pumping power is:
