Question 90 - In the calculation of the growth of bacteria, absorbance, A in spectrophotometry is used. According to Beer-Lambert Law, A = e x l x c where A is the absorbance of the solution (no unit), l is the distance of light travels through the solution (in cm), e is the molar absorptivity or the molar extinction coefficient [ in L / (mol.cm) ]. For a particular solute and fixed path length : As / Ao = Cs / Co where Ao is the observed signal for a known concentration Co, and As is the observed signal for a sample concentration Cs. (a) For a cell concentration of 560 cells / mL, a spectrophotometre gives an absorbance reading of 1.0. A mixture of concentration 3600000 cells / mL can be diluted in several operations, with each operation having a dilution of 1:20. How many dilutions should be made so that the concentration of this mixture can be calculated within a range of A = 0.0 to 1.0. (b) In another experiment, a sample tube of 1 cm in width is used. Let A = 0.06 and e = 0.0012 ml / (cell.cm). Find the cell concentration of the sample.

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Question 61 – A biochemical trolley of mass 15 kg is towing a trailer of mass 5 kg along a straight horizontal pathway. The trailer and the trolley are connected by a light inextensible tow-bar. The engine of the trolley exerts a driving force of magnitude 100 N. The trailer and the trolley experience resistances of magnitude 10 N and 30 N respectively. (a) Form 2 equations with unknowns T and a, that represents the equilibrium for the 2 systems of the trolley and trailer. (b) Solve the simultaneous equations from the 2 equations that are obtained in part (a) of this question. T is the tension of the tow-bar and a is the acceleration.

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ELECTRICAL TECHNOLOGY - EXAMPLE 16.3 : In the design of a solar power system steps of calculations below are followed : (a) The power output of the inverter of the solar panel is 100 watts. What is the power input, Pin to the inverter when the efficiency of the inverter is 50 %? (b) If the rated power of the inverter is 300 watts, how many inverter is needed for the solar panel? (c) Charge controller of V = 12 volts is used to supply power to the inverter. What is the input current I to the inverter? (d) If the charge controller capacity is 10 A, how many charge controllers are needed? (e) If a biochemical mixer consumes 100 watts, running for 2 hours per day, what is the energy consumption in kilowatt hour per day? (f) What is the input energy needed when the efficiency of the inverter is 50 %? (g) If your area receives 2.88 hours of full sunlight per day, how much energy, in kilowatt hour can be produced per day when one solar panel can produce 20 watts of power? (h) If you know that you have to produce total energy as the answer for (f), how many solar panels are needed? (i) Each V = 12 V battery has 5 ampere hours. If the total energy needed is in answer (f), then how many batteries are needed to run the biochemical mixer if without sunlight for 3 days?

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.37 : A biochemical engineering professional applies 5-step Du Pont formula in the accounting. Let Net Income = A, Earning Before Tax (EBT) = B, Earning Before Interest, Tax (EBIT) = C, Net Sales = D, Total Assets = E, Shareholders Equity = F. Let Tax Burden = A / B = 0.75, Interest Burden = B / C = 1.05, EBIT Margin = C / D = 0.27, Asset Turnover = D / E = 0.66, Return on Equity = A / F = 0.37. (a) Calculate the value of Leverage = E / F. (b) If AB + BC + CD + DE + EF = $$ 141932, find the values of A, B, C, D, E and F.

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Are some heat transfer services more prone to tube vibration that others for a shell and tube exchanger?

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What are the some common problems associated with dilute phase pneumatic conveying?

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i badly need a chemical process details for making a project...plz help me out......i m a btech final yr chemical engg student in a govt univ,and we have to make a detailed project on any chemical process with contents like...intro,kinetics , material balance,thermodynamics,process layout,process design,physical conditions,plant location,cost estimation etc.............if any one could help me i will never forget hi thankless work and always try to help u in whatever u ask.............

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For a given bulk solid how can the particle size distribution be determined?

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how interstage pressure of multistage compressor is calculated?

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Can anybody suggest the Methods/Procedures for estimation of oxygen, hydrogen, methane, carbon dioxide, CO, etc. in binary or complex gas mixtures?

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why distillation of water takes more time than toluene ,eventhough the later boiling point is more than water ?

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Explain what is a quick way to calculate frictional pressure drops in carbon steel pipe?

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