ENGINEERING ECONOMY - EXAMPLE 7.2 : In the purchase of a machine with a period n = 8.5 years, the minimum attractive rate of return, i = 12 %, the cost P = $55000, F = $4000 is the salvage, annual maintenance A = $3500. The return of the investment or equivalent uniform annual benefit is $15000. The equivalent uniform annual cost is P (A / P, i, n) + A - F (A / F, i, n). The investment is considered acceptable only when equivalent uniform annual benefit is greater than the equivalent uniform annual cost. From the compound interest table, (A / P, i = 12 %, n = 8 years) = 0.2013, (A / P, i = 12 %, n = 9 years) = 0.1877, (A / F, i = 12 %, n = 8 years) = 0.0813, (A / F, i = 12 %, n = 9 years) = 0.0677. Prove by calculations whether the investment above is acceptable.

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Why LMTD is calculated in Heat -Exchanger problems..Why dont we take average temperature??

4 Answers   Aker Solutions,

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Explain what information is needed to specify a mixer?

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How does a cyclone separator work?

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Question 83 - The United States of America Energy Information Administration reports the following emissions in million metric tons of carbon dioxide in the world for year 2012 : Natural gas : 6799, petroleum : 11695, coal : 13787. Coal-fired electric power generation emits around 2000 pounds of carbon dioxide for every megawatt hour generated, which is almost double the carbon dioxide released by a natural gas-fired electric plant per megawatt hour generated. If 1 metric ton = 1000 kg and 1 pound = 0.4536 kg, estimate the total energy generated by natural gas in the world for year 2012, in gigawatt hour.

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What are the customization steps in sap?

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What are some common precipitating agents used to remove metals from aqueous waste streams?

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What are the factors involved in considering the choice of dry screw compressor?

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ENVIRONMENTAL ENGINEERING - QUESTION 22.2 : Biochemical Oxygen Demand (BOD) could be calculated using the formula BOD = (DOi - DOf) (Vb / Vs) where Vb = Volume of bottle in ml, Vs = Volume of sample in ml, DOi = Initial dissolved oxygen in mg / L, DOf = Final dissolved oxygen in mg / L. (a) By using a bottle of Vb = 300 ml with sample Vs = 30 ml, find the BOD if DOi = 8.8 mg / L and DOf = 5.9 mg / L. (b) By using a bottle Vb = 600 mL with sample Vs = 100 mL, find the BOD if DOi = 8.8 mg / L and DOf = 4.2 mg / L. (c) Find the average BOD = [ Answer of (a) + Answer of (b) ] / 2. (d) If the BOD-5 test for (a) - (c) is run on a secondary effluent using a nitrification inhibitor, find the nitrogenous BOD (NBOD) = TBOD - CBOD. Let TBOD = 45 mg / L and CBOD = Answer of (c).

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What is the meaning – strain? In a distillation column, if a metal block 10 cm on a side is deformed so that it becomes 9 cm long due to cooling effect, what is the strain involved in percentage?

1 Answers  

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what is the difference between PFR ,MFR and batch rector

1 Answers   BARC, CPCL,

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can you explain about the design calculations and procedure of boiler

0 Answers   Reliance,

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