A steam turbine expands steam from 70 bar, 300 °C, to 6.5 bar. The flow rate of steam is 2.5 kg/s and the turbine generates 500 kW of power.
a) Determine the temperature at the outlet.
b) Determine the efficiency of the turbine.
c) Determine the entropy generation.
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1. Define BOD. Describe the measurement of BOD. Give an estimate of possible BOD values for the following three water types: pristine river, sewage and stormwater.
2. Classify microorganisms according to their source of energy and carbon. In your answer, define chemotroph, autotroph, heterotroph, phototroph, decomposer and producer.
3. In which class(es) are you likely to find algae, bacteria and fungi?
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2. “Famine is a natural occurrence.” Explain what is wrong with this statement by drawing on examples of famines in two different world regions. 500 words
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a) A natural draft cooling tower is used to cool the condenser of a 100 MW power plant. The water enters the tower at 40 °C at a rate of 80 kg/s. The range value of cooling tower is 15 °C. The water is cooled by air stream and the air entering the tower is at 1.01325 bar, 23°C and 60% relative humidity. The air leaves the tower as saturated at 32°C. According to the given data, using pyschrometric chart and steam table, determine the volumetric flow rate of air flowing into the cooling tower.
b) Describe briefly the definition and function of cooling tower fill material.
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Ethanol-water pressure swing distillation is to be designed with the use of FUG method. first column is at 1 bar and second is at 7 bar.
Column 1 results: minimium number of theoretical stages = 7, Rmin = 0.99 ,
Column 2 results: minimuim number of theoretical stages = 40 Rmin =8.4. How come the second distillation column is so costly due large amount of stages needed . This may be due to the relative volatility being close to 1 in the second column.
Is Pressure swing distillation a wise choice for the separation of water and ethanol
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a. Explain why magnetic materials that are to be used in information storage should have either square or rectangular-shaped hysteresis loops.
b. Why cannot pure iron metal be used in transformer cores?
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15,000 kg / h of colloidal solution of composition 5% by weight enter a simple evaporator and must be concentrated up to 20% by weight. Heating is effected by means of live steam which condenses at 110 ° C and the condensate leaves the condensation chamber without cooling. An absolute pressure of 250 mm Hg is maintained in the evaporation chamber. The solution has no appreciable increase in boiling point, and its specific heat can be considered equal to unity for all con. centrations. The feed enters at 20 ° C. The integral coefficient of heat transmission for the operating conditions is 1,800 Kcal / m2.h. ° C. The steam from the solution is condensed in a direct contact condenser with water that enters the condenser at 20 ° C and exits at 50 ° C. Calculate: a) The heating surface b) the hourly consumption of live steam c) hourly water consumption for condesacion
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Hydrogen chloride is made by the action of sulfuric acid on sodium chloride. The hydrogen chloride, being readily soluble in water, will form a solution of hydrochloric acid. Calculate the weight in grams of hydrogen chloride formed by the action of excess sulfuric acid on 1 kg of salt which is 99.5% pure NaCl.
a. 620.5 b. 320.1 c. 380.2 d.120.5
A sample of pure oxalic acid (H2C2O4.2H2O) weighs 0.200 g and requires 30.12 mL of KOH solution for complete neutralization. What is the normality of the KOH solution?
a. 0.2106 N
b. 0.0567 N
c. 0.2108 N
d. 0.1053 N
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What are the differences between the mechanism of free radical and coordination polymerization?
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141m3 / min of hydrogen measured at normal conditions and nitrogen in 300% excess enter an isobaric reactor. Inlet gases at 460 ° C are reacted in the presence of a catalyst to synthesize ammonia. The process has an efficiency of 26%. The exhaust gases are cooled to -40 ° C to condense the ammonia. Assume that the Cp of the gas phase species can be used in the temperature range, and that Cp NH3 (l) = 0.071938 kJ / mol K. Calculate the overall heat flow of the system in kW.
In: Other
Write is the sentences false or true:
1- Executing Process Group, required to track and review the
proegress and performance of the project.
2- The five Process Groups are dependent of application areas or industry focus.
In: Other
13. An object's mass and velocity determines which of
the following?
An object's gravitational energy
An object's kinetic energy
An object's activation energy
An object's potential energy
14.
What happens to the kinetic energy of a bowling ball
once it strikes pins?
It increases.
It stays the same.
It transforms to mechanical energy.
It decreases.
15.The force that is exerted on a machine is referred to as which type of force?
Advantage force
Output force
Input force
Initiation force
16. Which of the following are two force carrier particles for strong forces?
Pions and bosons
Gluons and electrons
Gluons and pions
Quarks and gluons
17.Scientists use the color change in quarks to do which of the following?
Determine the electrical charges
Differentiate similar quarks in a single particle
Differentiate one atom from another
Identify protons and electrons
18.
In a weak interaction, what accompanies the decay of subatomic
particles?
Decrease in mass
Release of energy
Absorption of energy
Increase in mass
19.Which of the following describes an electric field around a negative charge?
It will repel a negative test charge
It will repel a positive test charge
It will attract a negative test charge
It will attract a positive test charge
20.
What is the correct term for areas in which groups of atoms are
clustered together with their magnetic fields aligned?
Magnetism
North pole
Magnetic domain
Declination
21.Magnetic fields can be created by which of the following?
Voltage sources
Stationary electric charges
Electric current
Electric field
22. What is produced by the combination of an electric and magnetic field?
Electromagnetic fields
Magnetic domains
Electric current
Voltage
23.Which electromagnetic waves are felt as heat?
Visible light
Ultraviolet
Microwaves
Infrared
24.
The mass of how many objects is included in the universal
gravitation equation?
Three
Two
Six
One
25.According to Einstein's Theory of General Relativity, what dimension is added to the three dimensions of space to form the spacetime model?
Time
Length
Depth
Width
26. According to Newton's Law of Universal Gravitation, what is the force that holds planets in their orbits?
Gravity
Mass
Acceleration
Pressure
27. All objects are affected equally by the gravitational field regardless of their mass.
True
False
28. When electrical energy is sent to the metal on a stovetop, what happens to the level of thermal energy in the metal?
It does not change.
It decreases.
It can either increase or decrease.
It increases.
29. Which type of chemical reaction usually does NOT occur without an external source of energy?
Oxidation-reduction
Exothermic
Nuclear
Endothermic
30.What is the direction of flow for electrical energy within a direct current electricity circuit?
From a positive terminal to a negative terminal
From a negative terminal to a positive terminal
From a positive terminal to a positive terminal
From a negative terminal to a negative terminal
31. Which type of radiant energy is used to kill bacteria on hospital equipment?
Gamma rays
X-rays
Ultraviolet radiation
Infrared radiation
32.
What type of particle is propelled into an atomic nucleus, such as
uranium-235, to begin a nuclear fission reaction?
Neutron
Proton
Neutrino
Electron
33.What process do hospitals use to get clear images of the human body structures and functions?
Magnetic resonance imaging
X-rays
Magnetic relativity interference
Magnetic radioactivity indicator
34.
NOT all elastic objects have an elastic limit.
True
False
35.According to the inverse square law of sound, the intensity of sound waves at a distance of 20 feet from a sound source is what fraction of the intensity of the sound waves at a distance of 10 feet?
1/8
1/16
1/4
1/2
36.When an object that has been lifted in a gravitational field is released, gravitational potential energy is converted into what form of energy?
Chemical
Electromagnetic
Elastic
Kinetic
37.When a person climbs stairs, what happens to the gravitational potential energy of his/her body?
It is stored.
It becomes zero.
It decreases.
It remains constant.
38.
The equation "Δ heat = Δ internal energy + work" expresses which
Law of Thermodynamics?
Third
Second
Fourth
First
39.Which of the following is a system that is receiving heat energy from its surroundings?
Endothermic reaction
Exothermic reaction
Transformation reaction
Equilibrium reaction
40.Which of the following is a system that is receiving heat energy from its surroundings?
Endothermic reaction
Exothermic reaction
Transformation reaction
Equilibrium reaction
41.What is referred to as the highest point of a transverse wave?
Candela
Quark
Crest
Trough
42.Waves travel at different speeds through air and water.
True
False
43.
Which of the following can transfer energy waves through the
earth's crust?
A cellular device
An earthquake
A laser
A tsunami
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Give a picture of each type of fractionating column and compare them
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flows through a nozzle which has inlet areas of (10 cm ^ 2) . If the air has a velocity of (120 m/s) a temperature (300K) and a pressure of (700kpaat the inlet section and a pressure of 250kpa) at the exit find the mass flow rate through the nozzle and the velocity at the exit of the nozzle, assuming one dimensional isentropic flow. (R=287 J/kg. K), (K=1.4).
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There are wetlands that exist in South Dakota. I would like you to tell me the type of the wetlands in the state (I am thinking specifically the wetlands in the Lacreek refuge and the wetlands in eastern South Dakota-they are different types). Classify them, provide the value and function of them. Be sure to tell me about the plants, animals, macroinvertebrates, water quality-chemistry, soil types, etc. Why are wetlands important in these areas of South Dakota? What is the keystone species of the wetlands? How is this species important to the wetlands in South Dakota. Is Pollution affecting the wetlands in South Dakota? What is causing this pollution? How could you change that? Is Climate change affecting the wetlands? How/Why? You should have 2 full pages (double spaced of typing, 12 pt font, 1 inch margins, calibri or new time roman font). You can add photos and charts but make sure that you have 2 pages of writing (if I was to extract the photos and charts you should still have 2 pages of writing)
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