Determine the heating area required for the production of 4535.9 kg/h of 50% NaOH solution from a 10% NaOH feed entering at 37.8oC. Evaporation is to be carried out in a single-body standard evaporator for which an overall coefficient of 2839 W/m2.K is expected. Steam is available saturated at 446.09 kPa and the evaporator can be operated at 32.4kPa. (A = 137.07 m2)

An irreversible heat pump heats a home on a cold winter’s day. The home loses heat to the outdoors at a rate of Q̇ = B (Tin − Tout), where B is a constant equal to 0.5 [kW/K]. The coefficient of performance (COP) of irreversible heat pump is 50% of that for a reversible heat pump (i.e., β ′ = 0.5 β ′ rev ). If the indoor temperature is to be maintained at 20 °C and the power input to the heat pump is 5 kW: a) Determine the outdoor temperature, Tout. [5 marks] b) Determine the coefficient of performance of the heat pump, β′. [5 marks]

1. Refrigerant R134a is entering a condenser and is being cooled by water. The refrigerant enters the condenser with a mass flow rate of 6 kg/min at 1 MPa and 70 ⁰C and leaves at 35 ⁰C. The cooling water enters at 300 KPa and 15 ⁰C and leaves at 25 ⁰C. Neglecting any pressure drop, determine:

1. The mass flow rate of the cooling water
2. The heat transfer rate from the refrigerant to the water.
3. The rate of entropy production within the heat exchanger in kW/K

Can you please check the grammar and also put them in proper paragraphs?

From the results above, we can confidently state that the results obtained are reliable and accurate. The absolute quantification of DNA using a calibration curve in QPCR is an accurate method. And the quantity in each DNA sample can be quantified successfully using the standard curve equation (y = -3.383x + 50.979). The quality of the data obtained and interpreted using standard/calibration curves depends on the quality of the curve; this is, in turn, governed by various statistical factors. For instance, the accuracy of the curve can be considered focusing on its R2 values (regression coefficient). In the given curve, the R2 is 0.997, which is regarded as a good fit since it is nearly approaching the ideal value of R2, i.e., 1.
Another way to tell the quality and accuracy of the QPCR data is by the cycle shift of the dilution, which is governed by the slope of the curve. Since the given curve has an ideal slope (cycle shift) of -3.383, it makes the obtained data reliable and superior. In QPCR, the efficiency of the experiment is governed by the slope of the standard curve obtained (in other terms, a cycle shift between each 1/10 dilution). Since in the given standard curve, the slope is -3.383, it lies between −3.6 and −3.3, and hence the efficiency is 90-100%. This indicates that the QPCR experiment in question is accurate, and thus can be used for quantification.
Furthermore, qPCR tests can be done either absolutely or relatively. Relative quantification is when the internal reference genes are used to determine the differences (in folds) in the expression of the target gene. The change in mRNA expression levels is governed and used for quantification. Thus, this is considered as an indirect method and hence is ‘relative.’ However, the technique used here is a ‘direct’ one and is based on the exact quantification of DNA about a set standard/calibration curve. This makes it more reliable and accurate. Thus, the QPCR method is accurate and can be used for quantification.

A metal bar of length 30 cm, is initially at 25 ^oC. Then through an electrical wire heat is generated at a rate of 0.5 cal/cm³s. The left end (x = 0 cm ) is contacted with a medium at 10 ^oC. At the right end there is a heat loss due to the air convection at a flux of 0.6 cal/cm²s. The physical properties are, k = 2 cal/cm ^oC s, r = 8 g/cm³, Cp = 0.2 cal/g ^oC.

Use M = 0.25, Dx = 5 cm. Solve the model numerically to find the temperature at the length of 22.5 cm after 10 seconds.

The following is a simplified schematic of a corn ethanol process:

Milled Corn + Water --> Jet Cooking --> Fermentation --> Distillation and Dehydration --> 100% Ethanol

a. Calculate the theoretical yield of ethanol per kg of milled corn. (10 pts)

b. If the feed is slurry that contains 30 wt % milled corn, what is the highest ethanol concentration (wt. %) you would expect to see after fermentation? (10 pts)

The composition of corn is: starch - 62%, protein - 8%, water- 13%, fiber- 8%, fat - 7%, ash - 2%

A function of the feedback control system is desired: = (2 (s + 1)) / (s ^ 2 + 3s + 2). If the function transfer process is second order with gain = 4, time constant = 1, damping factor = 1.5, arrange the form of the PID controller function transfer using the direct synthesis method.

Which technique is commonly used to produce 316L stainless steel? Why?

Germanium-based semiconductors can be fabricated by adding the impurities of wither (i) bismuth or phosphorous and (ii) Aluminum or Gallium will produce ........................... and .................................. respectively

a) n-type and n- type

b)p-type and n-type

c) p-type and p-type

d) n-type and p-type

A solution of benzene and toluene is at equilibrium with vapour phase at 1 atm. Benzene and toluene form ideal solution. The vapour phase, which is at equilibrium with liquid (solution) is ideal gas. Activity of benzene in solution is 0.3.

a) Determine the temperature of the system at equilibrium.

b) Determine the vapour pressure of benzene at the system’s temperature.

Identify the likely corrosion mechanisms at the following locations: a. Hip stem made of titanium coupled with a cobalt chromium head b. Nitinol stent c. Fracture fixation plate made of stainless steel

A packed bed of uniform spherical particles of diameter, d= 2.5 mm, density ρs= 4000 kg/m3 , and voidage e= 0.45 is fluidised by means of a liquid of viscosity μ= 1 mN s/m2 and density ρ= 900 kg/m3 . (a) Starting from Carman’s and Ergun’s equations reported in the attached equations sheet, derive the corresponding expressions for the minimum fluidising velocity, umf, for both equations and explain their meaning.

A falling-head permeameter containing a silty clay loam soil sample has a sample diameter of 10 cm, a falling-head tube of diameter 2 cm, and a sample length of 4 cm. If the initial head is 15 cm. It falls 4 cm over a period of 6 hours. (a) Find the hydraulic conductivity of the soil sample in m/s and ft/d.

(b) What would be the hydraulic head after 12 hours?

(c) How long would it take for the hydraulic head to drop to 95% of the initial value?

An ideal gas is expanded from 5 bars to 1 bar through isentropic(reversible and adiabatic) operation of a turbine. For ambient conditions at 25°C and 1 bar, calculate the exergy of the turbine when the gas inlet temperature to the turbine is:

I) above ambient conditions at 250°C (8marks)

ii) below ambient condition at -50°C (8marks)

iii) comment on your answer to I and ii above (4marks)

(Cp=1.0KJ/Kg.K , n=1.4)