A petroleum wastewater has a suspended solids concentration of 400mg/L. The solid density is 1.8g/cm^3. The liquid density after filtering is 0.7g/cm^3.
Calculate the solid concentraction in ppm.
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A worker is exposed to a hazardous material at level that is about 2/3 of the allowable limit yet is reporting symptoms consistent with exposure to the material. Explain this in terms of exposure limits, absorbed dose, and other relevant factors.
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. A liquid mixture containing 25.0 wt% n-octane (ρoct = 703 kg/m3 ) and the balance n-decane (ρdec = 730 kg/m3 ) flows into a tank mounted on a balance. The mass in kg indicated by the scale is plotted against time. The data fall on a straight line that passes through the points (t = 3 min, m = 225 kg) and (t = 10 min, m = 510 kg). (a) Estimate the volumetric flow rate of the liquid mixture. (b) What does the empty tank weigh?
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One cubic meter of ethanol and 1 m3 of water are mixed together. Determine, (a) The composition of the resulting mixture in mass fractions. (b) The composition in mole fractions. (c) The volume of the resulting mixture (d) The composition as volume %.
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From a contaminant transport viewpoint, describe the advantages and disadvantages of selecting in situ bioremediation to clean a groundwater supply aquifer contaminated with petroleum hydrocarbons from a punctured underground storage tank. Benzene is compound of concern.
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Fluid: Shell and Tube Heat Exchanger Questions
1- What's the purpose of putting baffles on the shell side? How does having more baffles affect the shell fluid velocity? The flow rate? What about the total residence time the fluid spends in the shell? Explain your answers
2- Point where heat transfer occurs? Write formulas for that area
3- Write the Donahue equation for the Nusselt No. (dimensionless heat transfer coefficient) correlation for the shell side. It is valid for Re down ~400. Why do you think it works for such small Re?
4- What do the terms parallel and cross flow mean, and at what points in the shell and tube exchanges would you find parallel flow and cross flow?
5- Determine a formula for the area available for cross flow, A_cross. Draw a sketch and discuss and then do the actual formula
6- Determine the area for parallel flow, A_parallel, in the baffle window. Draw a sketch and discuss and then do the actual formula
7- Explain how the areas are used in the correlation for the shell side heat transfer coefficient.
8- Write the formula for Nusselt No. on the tube side.
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Compare and contrast the following hydrogen-storage technologies:
(1) compressed hydrogen; (2) liquid hydrogen; and (3) complex hydrides.
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For the titration of 25.0 mL of 0.20 M hydrofluoric acid with 0.20 M sodium hydroxide , determine the volume of based added when pH is a) 2.85 b) 3.15 c)11.89
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Outline of procedure:
Dilute bleach solution A 1/10.
Prepare analyte for titration by adding 10mL of diluted bleach solution, indicator and 5mL of 2 M HCl.
Titrate the analyte with 0.05524 M Na2S2O3.
Average volume of Na2S2O3 added = 31.25 mL
Question: Calculate the percent of sodium hypochlorite in the original bleach bottle using your averaged result. Show the calculation for solution A only. Which bleach solution is the more potent cleaning agent?
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A large insulated bottle containing 703 mL of water initially at 21.5 degrees C is cooled by adding ice at 0 degrees C. Assume the specific heat of liquid water is constant at 4.18 kJkg K
(a) If 82 grams of ice is added to the bottle, what will the final temperature be? (Degrees C)
(b) How much ice must be added if the desired temperatue is 5.1 degrees C? (grams)
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Fundamentals of Instrumentation & Controls
Distillation is a process of continuous boiling and condensing used to separate mixtures of different fluids. A practical example of distillation is the separation of crude oil into multiple gases and liquids (propane, butane, naphtha, hexane, etc.). Components with higher boiling points (typically denser fluids) collect at the bottom of the tower, while components with lower boiling points (typically lighter fluids) and gases collect at the top of the tower.
In this distillation tower, the levels of liquid products at the bottom and top are being controlled. Explain how the control loops work
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Drilling course.
List the advantages obtained by adding weighting material to mud?.
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Phosphorus is diffused into a thick slice of silicon with no previous phosphorus in it. If the surface concentration of the phosphorus is 1 x 10^18 atoms/cm^3, and its concentration at 1 micrometer needs to be 1 x 10^15 atoms/cm^3, after a diffusion time of 1 hour. What is the temperature needed for the process?
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Consider the following reaction: 3C2H5OH + 2 Na2Cr2O7 + 8H2SO4 à 3CH3COOH + 2Cr2(SO4)3 + 2Na2SO4 + 11 H2O
a) If a reactor is fed with a mixture having the following composition (in mol%): 20% de C2H5OH, 20% de Na2Cr2O7, and the balance H2SO4, which is the limiting reactant?
b) If 230 kg/h of C2H5OH are fed to the reactor, what is the amount (in kg/h) of the other two reactants that need to be fed to have a stochimetric feed?
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