13. Injury factors important in radiation-caused damage include:

1. Energy of the particles
2. Number of particles, or activity
3. Region of the body subjected to the ionization event
4. All of the above

A sieve-tray tower is being designed for a gas absorption process. The entering gas contain 1.8% (molar) of A, the component to be absorbed. The gas should leave the tower containing 0.1% (molar) of A. The liquid to be used as absorbent initially contains 0.01% (molar) of A. The system obeys Henry’s law with m = yi / xi = 1.41. At the bottom of the tower, the molar liquid-to-gas ratio is 2.115, while at the other extreme it is 2.326. For these conditions, it has been found that the Murphree efficiency is constant at 0.65. Estimate the number of trays required.

Question 3

A sheathed thermocouple is placed in a combustion chamber to measure the temperature of the gases at a certain point in the process. The thermocouple reading is 1110K and the inside wall temperature was measured at 1008K. The thermocouple has a surface area of 10 mm2 .

(a) A pitot probe is used to measure the velocity of the gas stream in the vicinity of the thermocouple tip. It measures a difference in static and dynamic pressure of 10 Pa. The convection heat coefficient (W/m2K) between the hot gases and the thermocouple is given by a correlation:

h = K.u^0.466

where: u is the velocity in m/s

K = empirical constant at high temperature = 50

What is the true gas temperature?

(b) A thermocouple is instead embedded inside the wall of a small conductive tube of inside diameter 20 mm, outside diameter 25 mm and length of 30 mm. The tube and embedded thermocouple are at a uniform temperature of 1110K. Suction is applied to the tube so that hot gas is drawn through the tube at 200 m/s. The heat transfer coefficient between gas and tube can be calculated by the correlation in part (a).

Assume the inside wall temperature of the combustion chamber is still 1008K. What is the true gas temperature? What is the temperature reduction of the gas in passing through the 30mm length of the tube?

Notes:

The Stefan Boltzmann constant is 5.669x10-8 W/m2 .K4 Assume gas density = 0.28 kg/m3 over the entire range of temperatures in this question. Assume gas Cp =1.19 kJ/kg.K over the entire range of temperatures in this question. The emissivity of the thermocouple and radiation shield and combustion chamber walls are all 0.75.

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.