Consider the use of coal for the production of electricity, Describe three advantages and three disadvantages for the use of coal to produce electricity.

There are 4 basic units in a nuclear reactor: fuel rods, nuclear modulators or primary cooling system, secondary cooling system and control rods. During the fission of Uranimum-235 describe the role of each units to control the reaction.

Compare the anthracite and bituminous coals to sub-bituminous and lignite. Your comparison should include:

            a. Where they are found in the US (state)

            b. energy content

            c. mining process   

During the latter third of the nineteenth century, leaders of the European “great powers” managed to avoid a generalized war within Europe, mainly because they were able to settle major disputes within the context of the “concert system.” But the concert system broke down in the summer of 1914. Why?

Consider an electrolytic cell consisting of molten AlCl₃ for the following questions:

(a) How many g of Al will be produced if a current of 0.152 A is passed through the electrolytic cell described above for 1.5 hours?

(b) How many Amps (A) of current is required to produce 1.69 g of Al if the electrolytic cell described above is operational for 1.5 hours?

(c) How much time (in hours) would it take for the electrolytic cell described above to produce 1.69 g of Al if 0.252 A of current is passed through the cell?

Note: Use Faraday constant, F = 96500 C / mole e^-

An underground storage tank has sprung a leak, sending 184 kilograms of ethanol into the

subsurface soil. Ethanol can be used as an electron donor under either aerobic (oxygen is the

electron acceptor) or sulfate reducing (sulfate is reduced to H

2

S) conditions. a) How many

electrons are transferred during the oxidation of ethanol (C

2

H

5

OH) to carbon dioxide (CO

2

)?

b) Construct the stoichiometric energy generating reaction from the half reactions associated

with the aerobic oxidation of ethanol to CO

2

. c) Construct the stoichiometric energy generating

reaction from the half reactions associated with oxidation of ethanol to CO

2

under sulfate

reducing conditions. e) Calculate the standard free energy (



G

0

) available from the sulfate

reducing energy generating reaction and compare it to the energy derived from the aerobic

oxidation. Which of the two modes of metabolism of ethanol provides more energy to the

organism and why you think this is the case? f) If you want to pump aerated water (7.0 mg

oxygen per liter) into the subsurface to support the mineralization of the ethanol, how many

gallons of water will you have to pump?

Use the tables in the Energy Calculations Appendix as needed.

Why is it important to consider the entire size range of particulate matter emissions when designing control strategies?

1. Shell momentum balance for flow between parallel plates. A fluid of constant density is flowing in laminar at steady state in the horizontal x direction between two flat and parallel plates. The distance between the two plates in the vertical y direction is 2yo. a) Derive the equations for momentum flux, velocity profile, average velocity, volumetric flow rate and the force exerted by the fluid on the plate. b) Show the shear stress and velocity profiles on the figure.

Consider the reaction

Fe(s) + 2HCl(aq)FeCl₂(s) + H₂(g)

for which H° = -7.400 kJ and S° = 107.9 J/K at 298.15 K.

(1) Calculate the entropy change of the UNIVERSE when 2.097 moles of Fe(s) react under standard conditions at 298.15 K.

S_universe =  J/K

(2) Is this reaction reactant or product favored under standard conditions?

_________reactantproduct

(3) If the reaction is product favored, is it enthalpy favored, entropy favored, or favored by both enthalpy and entropy? If the reaction is reactant favored, choose 'reactant favored'.

Estimate the top heat loss coefficient of a collector that has the following specifications:
Collector area= 2m2
Collector slope =35⁰
Number of glass covers = 3
Thickness of each glass cover =4 mm.
Thickness of absorbing plate =0.5 mm.
Space between glass covers = 20 mm.
Space between inner glass cover and absorber =40 mm.
Mean absorber temperature, Tp =80 ⁰C
Ambient air temperature =15 ⁰C
Absorber plate emissivity, εp =0.10.
Glass emissivity, εg =0.88
Wind velocity = 2.5m/s.
Assuming that temperatures of first, second and third covers are 288.53K, 293.4K and 313.93K, respectively.

If a mixture of water-ethanol containing a significant amount of methanol is being distilled (separation by VLE), can we state that the methanol is not a problem because it boils off first?

The International Space Station uses the electrolysis of water to continuously replenish the oxygen in the station’s atmosphere (the hydrogen formed is vented). The station’s electricity is generated by the four arrays of solar modules, which produce a total of 120 kW. Essential heating/cooling, circulation and steering equipment requires 75 kW. If one of the four modules fails completely, this leaves 15 kW for O2 production, which is run at a 2 V potential. How many astronomers can survive on board of the space station if each of them consumes 25 L of O2(g) per hour? Enter your numerical answer (rounded DOWN to the closest whole number, as we cannot have partial astronauts!) in the answer box. Assume 1 atm and 298 K as conditions.

To help you solve this problem, use the following information, suggested steps and hints:

a) Write the balanced half reactions at each electrode and the overall reaction!

b) If the electrolysis is carried out at 2 V potential, how many moles of electrons are produced in 1 s? (Hint: Calculate the Ampere available first using the following relationships: 1 W = 1 J/s; 1 J = 1 V·1 C; 1 C = 1 A·s)

c) Using your results from a) and b), how many moles of O₂ can be produced in 1 h?

d) How many moles of O₂(g) are required each hour for one astronaut, if s/he consumes 25 L of O₂(g) per hour? Assume 1 atm and 298 K.

e) How many astronauts can survive on the O₂ produced in c) if each consumes the number of moles calculated in d)?

Calculate the CO2 emission reduction in short tons/year that would result from increasing the efficiency of a 1,000 MW coal fired power plant from 33%-39%. The coal is 74% C and has a heat content of 9,800 Btu/lb. One short ton = 2,000 lb.

. What are the advantages of Unit dose packaging over Multiple dose packaging and what further improvement in former is needed to help patient-compliance?

What are the difficulties of patient-compliance of Multiple dose

     medications prescribed by the physicians and how proper

     packaging design can help resolve it?

Using fuel/ air ratios. Find the values to fill in the following combustion reaction chart.

Note: the octane is part of the automobile fuel whereas the Decane is part of the jet fuel.

Pure gaseous hydrogen at 10 atm is stored in a 10-cm-diameter, spherical steel pressure vessel having a wall thickness of 3 mm. The solubility of H2 in steel under these conditions is 0.085 m3 (STP)/(m3 of solid . atm) and the diffusivity of H2 in steel at 300oC is 3.8x10-10 m2 /s (independent of pressure). You may assume that the H2 partial pressure outside the vessel is zero.

a) Calculate the steady–state rate of leakage (in kmol/h) of H2 from the vessel.

b) Calculate the time in hours for the pressure inside the vessel to decrease to 9 atm, assuming the temperature stays constant at 300oC.