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.

We have a feed mixture of 22.0 mol% methanol, 47.0 mol% ethanol, 18.0 mol% n-propanol, and 13.0 mol% n-butanol. The feed is a saturated liquid, and F = 10,000 kmol/day. Recover 99.8% of methanol in distillate, and obtain a methanol mole fraction in distillate of 0.99.

a. Find D and B.

b. Find the compositions of distillate and bottoms.

A scientist is working with a hazardous, colourless, and odourless gas, silicon tetrafluoride (SiF₄). It is contained in a poly(ethyl methacrylate) (PEMA) polymeric container at 2 atm pressure. Please answer the following questions given the information below.

Permeant: silicon tetrafluoride (SiF₄), 104.1 g/mol

Polymer: poly(ethyl methacrylate) (PEMA)

P_{M,298 K} = 1.1x10^–14 cm³ STP cm/cm² s Pa

Q_d = 45 kJ/mol

Surface area of container: 300 cm²

Volume of container: 5000 cm³

Volume of room: 60 m³

Temperature: 298 K

1. If the airborne exposure limit for SiF₄ is 3 ppm over an 8 h period, what is the minimum wall thickness of the container?
2. If the pressure of the container is reduced to 0.5 atm, what is the new minimum wall thickness?
3. If the volume of the room is reduced by half, what is the new minimum wall thickness?
4. If the volume of the container is reduced by half, what is the new minimum wall thickness?
5. If the temperature of the room is increased by 20 ∘C, what is the new minimum wall thickness (please consider all factors that are affected by temperature)?

Determine the composition of the liquid in equilibrium with a mixture of 60 mole percent benzene and 40 mole percent toluene vapor, contained in a container subject to a pressure of 1 atm. Predict the temperature at which this equilibrium exists.

100 tons of MSW is combusted per day at a W.T.E. facility.

Assume the MSW is 100% dry volatile solids with the following molar ratio: C₉H₂O₄

Calculate the total oxygen demand of this 100 tons of waste in whole standard cubic feet per minute.

Postulate absorption mechanisms of prednisone. You need to justify your statement.