The diffusion of a molecule in a tissue is studied by measuring the uptake of labeled protein into the tissue of thickness L =149.4 um. Initially, there is no labeled protein in the tissue. At t=0, the tissue is placed in a solution with a molecular concentration of C1=1.2 uM, so the surface concentration at x=0 is maintained at C1. Assume the tissue can be treated as a semi-infinite medium. Surface area of the tissue is A = 93.9 cm2. Calculate the uptake of the labeled protein M by the tissue over 100 s.Please give your answer with a unit of pmol. Assuming the diffusion coefficient is known of D=1*10-9 cm2/s
In: Other
Problem 2. : A superheated steam at 20 bars and 500oC is fed to a turbine to generate electricity with a capacity of output of work at 500 kJ/kg. The existing steam is a saturated vapor at 2 bars. The surrounding environment temperature is 25oC. The outer surface temperature of the turbine is 150oC 1.) Clearly state your assumptions and draw the process flow diagram with labels ; 2.) Calculate the amount of heat exchanged between the system and surrounding ; 3.) Calculate the internal, external and total entropy generation for the turbine in kJ/kg-K and total entropy generation of the whole processes (turbine + surrounding environment) .
In: Other
In: Other
Fluid X is flowing in a circular pipe with a constant velocity ν (m/s). The fluid is cooled by a jacket kept at constant temperature, Tj. Fluid velocity is plug shaped , in other words uniform at radial positions. Assume that temperature is uniform in radial positions because of turbulent flow conditions; ρ and Cp of the fluid are constants. The inlet temperature (at z=0) is constant and uniform at To (To>Tj). Assume that thermal conduction of heat along the z axis is small relative to convection. Heat transfer film coeffiecient h is given as 40 (J/m2.°C.s).
Δz
Cooling jacket, Tj
v, To, ρ, Cp
R
z z=0
a. Perform an unsteady state energy balance using shell balance technique and obtain a PDE model. Do not solve.
b. Perform a steady state energy balance using shell balance technique to obtain an ODE model . Solve the model to find the steady state temperature distribution as a function of axial position z. Take Tref=0.
c. Given that; at t=0, To=90°C; ν=0.5 m/s; h=40 J/(m2.°C.s); R=0.1m; ρ=100 kg/m3; Tj=10 °C and Cp=10J/(kg°C); find the temperature value at z=1 m? (Ans.= 26 °C)
In: Other
Predict trends in glass transition and melting temperatures. Why are these properties considered in the design of consumer products like plastic cups and ice trays?
In: Other
Change in concentration of salt in a reactor can be
modeled
by the following equation y’ = ty+y1/2
Initial concentration of salt at time (t= 0 hours) is 1g/l,
y(0)=
1, find the concentration of salt after 0.2 hour y(0.2)= ? by
using Euler, Heun and RK4 methods. Use h= 0.1
In: Other
In: Other
4. (20) A stoichiometric mixture of CO and O2 enters a reactor at 100 oC. CO2, CO and O2 leave the reactor in chemical equilibrium at 1527 oC and 2 atm. Calculate the partial pressures of CO2, CO and O2 in the products.
CO + ½ O2 = CO2: ΔGo373K = -250.8 kJ
CO + ½ O2 = CO2: ΔGo1800K = -127.4 kJ
In: Other
The reaction rate constants for an investigation of ascorbic acid deterioration in a multivitamin mix during storage at different temperatures were:
|
Temperature (oC) |
20 |
30 |
50 |
60 |
70 |
|
Reaction constant (mgml-1day-1) |
0.00062 |
0.024 |
0.24 |
0.66 |
0.18 |
(i) Determine the activation energy at 70 oC
(ii) Determine the rate constant at 80 oC
(iii) Suppose the temperature increased from 20 oC to 70 oC, determine the sensitivity of the reaction rate to this rise is temperature.
(iv) At what time would the ascorbic acid deteriorate by 50%?
In: Other
A binary mixture of benzene and toluene will be separated by continuous distillation. The mixture consists of 20% mol of benzene and 80% mol of toluene at the bubble point of 91ºC. The binary mixture is available at 100 mol h-1 and the separation should deliver a distillate product that has a concentration of 90% mol of benzene and that contains half of the benzene in the feed stream. a) Plot the equilibrium line for benzene. b) Determine the minimum reflux ratio. b) Determine the minimum number of stages required to achieve this separation. Note: You may require looking for properties of components◢
volatilities of components need to looked up
Continue
In: Other
|
Ammonia reacts with sulphuric acid giving ammonium sulphate 2NH3 + H2SO4 à (NH4)2SO4 20 m3 of ammonia at 1.2 bar and 300 K reacts with 40 kg of sulphuric acid. Determine the excess reactant and Calculate the theoretical yield. |
In: Other
You have a sample consisting of unknown concentrations of methanol, ethanol, and 1-propanol. That is, you have one jar that contains all three of these chemicals. You don’t know the concentrations of the chemicals. You also have individual 100% solutions of methanol, ethanol, and 1-propanol. So, one jar of 100% methanol, one jar of 100% ethanol, one jar of 100% 1- propanol. You have methylene chloride to use as a solvent. determining the concentration of each alcohol in your unknown mixture
In: Other
In: Other