(iii). Aerated water flows through a cylindrical tube of inner radius 1 cm. The tube wall is porous and has a thickness 0.2 cm. The outer surface of the tube is in contact with pure solvent at a pressure lower than that inside the tube. The mass transfer rate of air per until length of the tube is 0.05 g/s. Estimate the mass transfer rate for a similar process in which the tube used is of the same material, porosity and inner diameter, but has a wall thickness of 0.4 cm. (iv). In an experiment, a naphthalene ball of radius 2 cm was found to dissolve into air in 10 days. Estimate the time required for a ball of radius 4 cm to dissolve under identical environmental conditions. (v). State whether the following assertion is true or false. Briefly justify your answer. "In a steady state diffusion process, mass flux is constant with respect to the distance from the source."

(iii). Aerated water flows through a cylindrical tube of inner radius 1 cm. The tube wall is porous and has a thickness 0.2 cm. The outer surface of the tube is in contact with pure solvent at a pressure lower than that inside the tube. The mass transfer rate of air per until length of the tube is 0.05 g/s. Estimate the mass transfer rate for a similar process in which the tube used is of the same material, porosity and inner diameter, but has a wall thickness of 0.4 cm. (iv). In an experiment, a naphthalene ball of radius 2 cm was found to dissolve into air in 10 days. Estimate the time required for a ball of radius 4 cm to dissolve under identical environmental conditions. (v). State whether the following assertion is true or false. Briefly justify your answer. "In a steady state diffusion process, mass flux is constant with respect to the distance from the source."

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Saturated, pure steam at a temperature of 170 oC condenses on the outer surface of avertical tube of outer diameter 2 cm and length 1.5 m. The tube surface is maintained at auniform temperature of 150 oC.Calculate:a) the local film condensation heat-transfer coefficient at the bottom of the tube. b) the average condensation heat-transfer coefficient over the entire length of the tube. c) the total condensation rate at the tube surface.
QUESTION 2 A new induced raft cooling tower is circulating 120 000 L/h of water that is cooled from 50 °C to 22 °C. How much blow-down and make-up is required to maintain the concentration of dissolved solids in the circulating water at four times the concentration in the make-up water? Assume the following: - The evaporated water contains no dissolved solids so all solids entering the system in the make-up must be removed by blow-down and windage. - The windage value of the induced draft cooling tower is 0.3% for each 5.6 °C. - The evaporative losses value is 1.1%.
The sensible heat-transfer coefficient for a dry surface has been determined to be 50 W/(m2-C) at a certain Reynolds number. Estimate the total heat transfer to the surface per unit area at a location where the wall temperature is 10 C and the state of the moist air flowing over the surface is given by 24 C dry bulb and 18 C wet bulb. Assume that the Reynolds number does not change and the Lewis number is 0.82. Assume that the condensate present on the surface will increase the transfer coefficients by about 15 percent.
Nutrient media is flowing at a rate of 1.5 L min in a tube that is 5 mm in diameter. The walls of the tube are covered with antibody-producing cells, and these cells are anchored to the tube wall by their interaction with a special coating material that was applied to the surface of the tube. If one of these cells has a surface area of 500 um², what is the amount of force that each cell must resist as a result of the flow of this fluid in the tube? Assume the viscosity of the nutrient media is 1.2 cP=0.0012 Pa sec.
True or False? Justify your answer. A. In a rectangular drug delivery device that consists of a drug reservoir and a diffusion barrier made of a polymer gel, the steady state diffusion (mass transfer) rate through a barrier of thickness 1 cm was found to be 20 mg/day. If the barrier thickness were to be doubled keeping the reservoir drug concentration the same, the mass transfer rate would be 10 mg/day. B. In a spherical drug delivery device consisting of a core reservoir surrounded by a polymer gel barrier, the steady state diffusion (mass transfer) rate through a barrier of thickness 1 cm was found to be 20 mg/day. If the barrier thickness were to be doubled keeping the reservoir drug concentration the same, the mass transfer rate would be 10 mg/day.
A thin plastic membrane is used to separate helium from a current.gaseous. Under steady-state conditions, a concentration of helium in the membrane is known to be 0.02 and 0.005 kmol/m³ on the inner and outer surfaces, respectively. If the membrane has a thickness of 1 mm and the coefficient ofbinary diffusion of helium to plastic is 10^(-9) m²/ s, what is the value of the flow diffusive?
A tanker ship is transporting 0.798 kg/m3 of a rare gas in its tank. After the fill-up, the 1.94 m long pipe used to fill the tank was left open for 10.4 hours. In that time, 11.7 x10-4 kg of the gas diffuses out of the tank, almost nothing compared to the original quantity of gas in the tank. If the concentration of that gas in our atmosphere is typically zero, and the diffusion constant of that gas is 2.13 x10-5 m2/s, what is the cross-sectional area of the pipe?
In a paint manufacturing process, two different colored paints are being mixed in an infinitelylarge drum.Paint A, with a concentration of 30% pigment, is pumped into the drum at a rate of 10 liters perminute.Paint B, with a concentration of 17% pigment, is pumped into the drum at a rate of 17 liters perminute.Both paints have the same density of 1.0 kg/liter.If the mixture is cotinuously stirred and drained from the drum at a rate of 22 liters perminute, what isthe concentration of pigment in the resulting mixture?
The sensible heat-transfer coefficient for a dry surface has been determined to be 50 W/(m2-C) at a certain Reynolds number. Estimate the total heat transfer to the surface per unit area at a location where the wall temperature is 10 C and the state of the moist air flowing over the surface is given by 24 C dry bulb and 18 C wet bulb. Assume that the Reynolds number does not change and the Lewis number is 0.82. Assume that the condensate present on the surface will increase the transfer coefficients by about 15 percent
**JUST PART C PLEASE** The pressure in a pipeline that transports helium gas at a rate of 5 lbm/s is maintained at 14.7 psia by venting helium to the atmosphere through a 0.25-inch internal diameter vertical tube that extends10 ft into the air. Helium and atmospheric air are at 60F. The diffusion coefficient for a mixture of helium with air is 2.79 ft2/h at 77oF. Assume the mole fraction of helium in the atmosphere is negligible, and the mole fraction of air in the helium pipeline is negligible. Determine the following:(a) The mass flow rate of helium flowing to the atmosphere through the tube.(b) The mass flow rate of air that infiltrates into the pipeline.(c) The net mass flow rate in the vertical tube.
*** 32. A double-chambered container contains one mole of helium in one of its 1000 cm³ Pull to volume chambers. The container is well-insulated, and of low specific heat, so that no appre- remove ciable heat is added to the gas during the process we describe. The gas is initially at a tempera- ture of 300 K and a pressure of 1 atmosphere. The partition between the two chambers is then quickly raised, and the gas expands freely to fill the entire container. Whenever a monatomic gas like helium doubles its volume adiabatically like this, the pressure in the gas will drop to 0.315 of what it was before (for reasons that we did not explain in this chapter), so the final 1000 cm3 1000 cm³ pressure of the expanded gas will be 0.315 atmospheres. a) What is the temperature of the gas after the expansion? b) What is the change in the internal energy of the gas? c) How much heat is added to the gas? [Hint: Maybe read the problem again.] d) How much work is done by the gas as it expands? [Hint:…
Develop a mathematical expression for the effective mass transfer rate achieved by an implanted drug delivery device that consists of a spherical core of radius R0 containing the drug, surrounded by a gel barrier of uniform thickness (R1-R0), i.e., the radius of the device (reservoir + barrier) is R1. When implanted, a scar tissue layer of thickness (R2-R1) forms around the device. State and justify any assumptions you might make. For a spherical shell, the flux and mass transfer rate are given by the following expressions (see notes “Steady State Molecular Diffusion: Geometry Effects”