2.34. You arrive at your lab at 8 a.m. and add an indeterminate quantity of bacterial cells to a flask. At 11 a.m. you measure the number of cells using a spectrophotometer (the absorbance of light is directly related to the number of cells) and determine from a previous calibration that the flask contains 3850 cells, and at 5 p.m. the cell count has reached 36,530.
- Fit each of the following formulas to the two given data points (that is, determine the values of the two constants in each formula): linear growth, C = Co + kt; exponential growth, C = Coe*'; power-law growth, C = ktb. In these expressions, Co is the initial cell concentration and k and b arc constants.
- Select the most reasonable of the three formulas and justify your selection.
- Estimate the initial number of cells present at 8 a.m. (/ = 0). State any assumptions you make.
- The culture needs to be split into two equal parts once the number of cells reaches 2 million. Estimate the time at which you would have to come back to perform this task. State any assumptions you make. If this is a routine operation that you must perform often, what does your result suggest about the scheduling of the experiment?

Want to see the full answer?
Check out a sample textbook solution
Chapter 2 Solutions
ELEM.PRINCIPLES OF CHEMICAL PROCESSES
Additional Engineering Textbook Solutions
Starting Out with Java: From Control Structures through Objects (7th Edition) (What's New in Computer Science)
Starting Out With Visual Basic (8th Edition)
Mechanics of Materials (10th Edition)
Database Concepts (8th Edition)
Introduction To Programming Using Visual Basic (11th Edition)
Java: An Introduction to Problem Solving and Programming (8th Edition)
- Problem 1 Marks: 60 Section: 1a): 30 marks, Section 1b):30 marks A laboratory scale fluidized bed is considered for studying a catalytic ozone decomposition. a) It is requested to derive model equations under the following assumptions: ■ Operation of the catalytic reactor under steady state conditions, There is no influence of thermal ozone decomposition reactions. The fluidized bed includes bubbles and dense phase. □ The dense phase can be simulated using a CSTR The fluidized bed bubbles contain catalyst particles and can be simulated as a DSTR (batch). □ The jets contain particles and can be simulated with a PFR. The influence of the freeboard has to be considered using a PFR model. The available catalytic reaction rate model is r (moles/gcat.s)= -k CA b) Same than on a) under unsteady state conditions, using an absorbable and reactive tracer. Note: A step-by step derivation of the model equations is required here. A quick answer will not do. Problem 2 Marks: 40 Section 2a: 30 marks,…arrow_forwardPenicillin process Penicillium chrysogenum is used to produce penicillin in a 90,000-litre fermenter. The volumetric rate of oxygen uptake by the cells ranges from 0.45 to 0.85 mmol l^−1 min^−1 depending on time during the culture. Power input by stirring is 2.9 W l^−1. Estimate the cooling requirements.arrow_forwardProduction of bakers’ yeast Bakers’ yeast is produced in a 50,000-litre fermenter under aerobic conditions. The carbon substrate is sucrose; ammonia is provided as the nitrogen source. The average biomass composition is CH_1.83O_0.55N_0.17 with 5% ash. Under conditions supporting efficient growth, biomass is the only major product and the biomass yield from sucrose is 0.5 g g^−1. If the specific growth rate is 0.45 h^−1, estimate the rate of heat removal required to maintain constant temperature in the fermenter when the yeast concentration is 10 g l^−1.arrow_forward
- Sensible energy change Calculate the enthalpy change associated with the following processes:(a) m-Cresol is heated from 25°C to 100°C(b) Ethylene glycol is cooled from 20°C to 10°C(c) Succinic acid is heated from 15°C to 120°C(d) Air is cooled from 150°C to 65°Carrow_forward▼ Enzyme conversion An immobilised enzyme process is used in an ice-cream factory to hydrolyse lactose (C12H22O11) to glucose (C6H12O6) and galactose (C6H1206): C12H22O11 + H2O →→ C6H12O + C6H12O6 Gel beads containing ß-galactosidase are packed into a column reactor; 2500 kg of lactose enters the reactor per day as a 10% solution in water at 25°C. The reactor operates at steady state and 32°C; all of the lactose is converted. Because the heat of reaction for enzyme conversions is not as great as for cell culture, sensible heat changes and heats of mixing cannot be ignored. Lactose Water Ah (kJ gmol¹) C, (cal g¹ ºC-¹) Ahm (kcal gmol¹) 3.7 -5652.5 0.30 1.0 Glucose -2805.0 0.30 5.6 Galactose -2805.7 0.30 5.6 (a) What is the standard heat of reaction for this enzyme conversion? (b) Estimate the heating or cooling requirements for this process. State explicitly whether heating or cooling is needed.arrow_forwardBacterial production of alginate Azotobacter vinelandii is investigated for production of alginate from sucrose. In a continuous fermenter at 28°C with ammonia as nitrogen source, the yield of alginate was found to be 4 g g^−1 oxygen consumed. It is planned to produce alginate at a rate of 5 kg h^−1. Since the viscosity of alginate in aqueous solution is considerable, energy input due to mixing the broth cannot be neglected. The fermenter is equipped with a flat-blade disc turbine; at a satisfactory mixing speed and air flow rate, the power requirements are estimated at 1.5 kW. Calculate the cooling requirements.arrow_forward
- Preheating nutrient medium Steam is used to heat nutrient medium in a continuous-flow process. Saturated steam at 150°C enters a coil on the outside of the heating vessel and is completely condensed. Liquid medium enters the vessel at 15°C and leaves at 44°C. Heat losses from the jacket to the surroundings are estimated as 0.22 kW. If the flow rate of medium is 3250 kg h^−1 and its heat capacity is 0.9 cal g^−1 °C^−1, how much steam is required?arrow_forwardQ3] Determine the optimal operating conditions (XA, t, and CR) in a mixed flow reactor to maximize the concentration of R (CR) in the effluent, where an aqueous feed A with an initial concentration of CA0-40 mol/m³ enters the reactor, undergoes decomposition, and exits as a mixture containing A, R, and S. K₁ AR, FR = k₁C, k₁ = 0.4 m³/(mol min) SA AS, rs = k₂CA, k₂ = 2(min), CA0 = 40 mol/m³arrow_forwardConsider the parallel decomposition of A of different orders with FR = 1, rs = 2CA and IT = C. Determine the maximum concentration of desired product obtainable in mixed flow reactor and plug flow reactor. (1) R is desired product and CA0 = 2. (2) S is desired product and CA0 = 4. R S Tarrow_forward
- 1. Copper is known to be toxic to fish, and in particular, the free ion Cu²+ species typically shows greatest toxicity. a. Calculate the speciation of Cu(II) for freshwater at a pH value of 8.3 as the hardness increases from 20 (soft) to 100 (moderately hard) to 200 (very hard) mg/L as CaCO3. Assume that the total divalent Cu(II) concentration is 10 µg/L. b. Based on your findings in part (a), do you think it is appropriate to set a single regulatory limit or should it depend on variables such as pH and hardness? Explain your answer.arrow_forwardMaterial Sciencearrow_forwardElectronic devices found in integrated circuits are composed of very high purity silicon to which has been added small and very controlled concentrations of elements found in Groups IIIA and VA of the periodic table. For Si that has had added 9.1 × 1021 atoms per cubic meter of antimony compute (a) the weight percent and (b) the atom percent of Sb present. (Hint: use Equation 100 C₁ = 1 + NAP2 N1A₁ P2 P1 (a) 0.00636 %wt (b) i 0.0182 %atarrow_forward
- Introduction to Chemical Engineering Thermodynami...Chemical EngineeringISBN:9781259696527Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark SwihartPublisher:McGraw-Hill EducationElementary Principles of Chemical Processes, Bind...Chemical EngineeringISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEYElements of Chemical Reaction Engineering (5th Ed...Chemical EngineeringISBN:9780133887518Author:H. Scott FoglerPublisher:Prentice Hall
- Industrial Plastics: Theory and ApplicationsChemical EngineeringISBN:9781285061238Author:Lokensgard, ErikPublisher:Delmar Cengage LearningUnit Operations of Chemical EngineeringChemical EngineeringISBN:9780072848236Author:Warren McCabe, Julian C. Smith, Peter HarriottPublisher:McGraw-Hill Companies, The





