Which of the following statements are true and which are false?

The decimal reduction time D is the heating time in min at a certain temperature required for the number of viable microbes to be reduced to 10% of the original number.

The z value is the temperature increase required for a ten-fold decrease in D.

Thermal death time is the heating time required to give commercial sterility.

Thermal death time does not depend on the initial microbial load.

The D value does not depend on the initial microbial load.

The D value of a microorganism is independent of the food item.

The D value of a microbe is a measure of the thermal resistance of the microbe.

If the number of microbes in a process has to be reduced from an initial load of 10⁶ to a final 10⁴, the required thermal death time will be 10D.

A copper-nickel diffusion couple is annealed at 1025 C for 100 hours. The specimen is partially sectioned into sequential thin layers, each of 50 micrometers thick, located around the original Cu/Ni interface. The sections are analyzed using an electron microprobe with the following results:

Determine the diffusion coefficient for Cu-Ni at 1025 C using the Boltzmann-Matano method.

Assume that the distribution coefficient (Kd) for Hg(II) is 104.9 (log Kd=4.9), the concentration of suspended sediments (Csed) is 10 mg L-1, the settling velocity (vs) of the silt-size particles is 4.17 cm hr-1, the area (A) of the water body is 50 km2 and the mean depth (H) is 6 m. What is the rate constant for removal of Hg(II) by scavenging, in units of per day?

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Methyl alcohol and water are brought into contact in such a way that the two components form a layer 1.00 cm thick on top of a 3cm deep layer of water. Both components(water and methyl alcohol) are mutually diffusing into each other at 27⁰C, there is no mixing of water and methyl alcohol and they are fully miscible. Calculate the following:

(1) The rate of diffusion of methyl alcohol into water, include a rough diagram indicating all given variables.

(2) The rate of diffusion of water into methyl alcohol

The compression ratio is 10 in the air standard Otto cycle. Pressure at the beginning of the compression stroke is 1XY kPa and the temperature is 15 ºC. The heat transfer to the air for each cycle is 18XY kJ / kg air. Draw the T-s and P-v diagrams. (x=9 y=8).

Note: Accept that specific temperatures do not change with temperature. Take k = 1.4 and Cp = 1.0031 kJ / kg-K.

a)

For question 1, we draw the temperature and pressure values ​​at the end of each condition in the cycle by drawing a table.

b)

Write the thermal efficiency for Question 1.

c)

For Question 1, write down the mean effective pressure. (Unit kPa)

d)

Calculate the efficiency of the Carnot machine operating between the maximum and minimum temperatures in Question 1.

Considering a geyser in a home, classify each of the following as an open system, closed system,neither or both:
(a) the geyser is being filled with cold water
(b) hot water is being drawn from the tap
(c) the geyser leaks
(d) the heater is turned on to heat the water
(e) the geyser is full and the heater is turned off.

Elementary , irreversible and isothermal gas phase reaction A+B--------- C. Reaction rate constant is 20M^-1min^-1 at temeperature 80 degree celcius . Feed flow rate (10L/min) to the plug flow reactor , which volume is 80 litres, contains 2%A and 2%B and inert gas temperature of 80 degree celcius and pressure 6 bar . Calculate the conversion of A.

During their vacation, the Baldwin Family hired contractors to repaint their house. One warm afternoon, fire broke out on one side of the house and the house burned to the ground. The painters had left linseed oil soaked rags out near the house, which they had been using to finish the wood deck. An arson investigator was sent out to investigate whether the fire could have been deliberately set. How could the lab technician determine whether the fire was accidental (or not)? Clearly describe what kinds of samples would need to be collected and what kind of chromatographic analysis would need to be 5 performed. Discuss the type of columns, standards and detectors you would use and what type(s) of compounds the analyst would seek to analyze given the information above. Hint: Do not ignore the linseed oil soaked rags.

A gas mixture with a volumetric composition of 35% CO + 65% N2 is burned with fuel, 63% excess air. Fuel enters the furnace at 100 0C and air enters at 25 0C. Calculate the adiabatic (theoretical) flame temperature.

b) Ethane gas at 1 bar and 25 oC is compressed adiabatically to 55 bar in a steady-state flow process for which W = 10 J mol-1. Assume ethane is ideal gas at its initial state and the residual enthalpy of the gas at its final state is - 3270 J/mol, and its heat capacity is constant (CP = 4.5 R), the temperature of ethane at the final state, i.e., after compression, is

i. 403.3 oC; ii. 403.3 K; iii. 130.1 oC; iv. 130.1 K v. Other

c) Air enters the opening of a jet engine of an airplane flying at Mach 2.2. We want to convert the kinetic energy of the incoming airflow to pressure before the air is introduced to the entrance of a compressor, which is to compress the air stream to a pressure that is slightly higher than that in the combustion chamber. To increase the efficiency of such a conversion of energy, we should design the engine entrance channel as a diffuser so that

i) dP/dx > 0 ii) du/dx < 0; iii) dA/dx < 0; iv) I, ii, and iii ; v) None

Answer BOTH and EXPLAIN WHY