Questions and Answers of Fundamentals Momentum Heat

A spherical pellet containing pure solid A is suspended in a flowing liquid stream at 20°C. The initial diameter of the pellet is 1.0 cm, and the bulk liquid velocity is 10.0 cm/s. Component A is
A spherical drug capsule dispenses Dicyclomine (an irritable bowel syndrome drug) to the body’s gastrointestinal tract over time. Initially, 2.00 mg of Dicyclomine (mAo) is loaded into the
A spherical silica gel adsorbent particle of 0.20 cm diameter in placed in a rapidly flowing air stream at a velocity of 50 cm/s containing 1.0 mole% of H2O vapor at total system pressure of 1.0 atm
An engineer proposes to use the mass-transfer equipment shown in the figure (next page) to prepare a water stream containing dissolved oxygen. Liquid water containing no dissolved oxygen is fed to
An aeration basin is used to oxygenate wastewater at 283 K. The basin is filled to a depth of 4.55 m with 283 m3 wastewater of 0.050 mmole/L initial dissolved oxygen (O2) concentration. The filled
A 1.75-cm diameter naphthalene mothball is suspended in an air stream at 280 K, 1.0 atm, and constant velocity of 1.4 m/s. Solid naphthalene exerts a vapor pressure of 2.8 Pa at 280 K. Consequently,
Investigators studying the mass transfer from single spheres recommended the generalized equation Sh = 2.0 + C RemSc1/3 As discussed in Section 30.1, the value of 2.0 can be derived
Pure liquid benzene (C6H6) at 290 K flows as a thin film down the outside of a vertical, 0.08-m-diameter cylinder at a flow rate of 4.0 kg/hr. Dry air at 290 K and 1.0 atm flows perpendicular to the
A €œstent€ is used to €œprop up€ a clogged artery to allow blood to pass through it. But stents can also be loaded with drugs to facilitate the timed release
Beaver Brewing Corporation has received a contract to produce carbonated beverages. A packed-bed absorption tower will be used for dissolving carbon dioxide (CO2) gas into water. In the present
A packed tower, 2.0 ft in diameter and 4.0 ft in packed height, is used to produce a solution of dissolved oxygen in water for a biochemical process. The tower will be pressured to 5.0 atm with pure
An aeration basin is used to oxygenate wastewater at 283 K. The basin is filled to a depth of 4.55 m with 283 m3 wastewater of 0.050 mmole/L initial dissolved oxygen (O2) concentration. The filled
An ozone (O3) treatment system is proposed to oxidize organic materials from wastewater. The first step in this process is to dissolve O3 in the wastewater. The wastewater has been stripped of all
A gas stream of flow rate 10.0 lbmole/ft2· h contains 6.0% sulfur dioxide (SO2) by volume in air. It is desired to reduce the SO2level in the treated gas to no greater than 0.5% in a counter
A natural gas stream with a total volumetric flow rate of 880 standard cubic meters (SCM) per hour (std m3/h), temperature of 40°C, and total system pressure of 405 kPa is contaminated with 1.0
Exit gas from an amination reactor contains 10 mole% ammonia (NH3) vapor in a nitrogen (N2) carrier gas. This gas mixture is fed into the bottom of a packed tower at a molar flow rate of 2.0
The cooled exhaust gas from a reactor that makes silicon by the chemical vapor deposition of trichlorosilane contains 8.0 mole% anhydrous HC1 vapor and 92.0 mole % hydrogen (H2) gas at 25°C. The
Wastewater contaminated with 1,2,2-trichioroethane (C2H3C13, molecular weight 133.5 g/gmole) will be treated in a counter current packed tower using contaminant-free air as the stripping gas. In the
Acetone, a solvent used for cleaning of silicon wafers, is highly volatile with a vapor pressure of 185 mm Hg at 20°C and 148 mm Hg at 15°C. An air handling system at 20°C captures the
A process waste gas stream containing 5.0 mole% of benzene (solute A) enters the bottom of a packed tower. The tower is packed with 0.5-inch ceramic Raschig rings, and the diameter of the tower is
A pilot-scale tower packed to a height of 6.0 ft with 5/8- inch ceramic Raschig rings is used to study the absorption of carbon disulfide (CS2, solute A) from nitrogen gas (N2) into a liquid
A packed-bed liquid stripping process will be designed to remove benzene from contaminated wastewater. A liquid wastewater stream containing dissolved benzene of concentration 693 mg benzene/L (mole
A packed tower is used to remove component A from a gas stream mixture containing 12.0 mole% A and 88.0 mole% inerts. The gas mixture is fed to the bottom of the tower, and the desired superficial
It is desired to remove 83.3% of dissolved NH3from an aqueous stream containing 10.7 mole% NH3in water using a packed tower in counter current flow at 1.0 atm and 30°C. The flow rate of this
An aqueous waste stream containing 1.0 mole% of hydrogen sulfide (H2S) dissolved in water will be treated by stripping the liquid with air in a counter current packed tower at 20°C and 12.50 atm
A liquid stream of total molar flow rate 100 lbmole/h that contains 0.20 mole A/mole solvent must be reduced to 0.050 moles A/moles solvent. It is proposed to use a packed tower for this purpose. A
A waste gas of total inlet flow rate 10.0 lbmole/ft2· h containing 0.050 moles solute A/mole carrier gas is treated counter currently in packed tower with a nonvolatile, solute- free absorbing
An aeration basin is filled to a volume of 425 m3with wastewater containing dissolved hydrogen sulfide (H2S) of initial concentration 0.300 gmole/m3. The aeration basin is equipped with 10 gas
A crystalline silicon wafer of 10 cm diameter and 1.0 mm thickness is coated with a thin film of elemental arsenic metal (As), which is a semiconductor dopant. The As-coated silicon wafer is
One step in the processing of cucumbers to pickles is the pickling process itself. In one method of making pickles, young cucumbers with no waxy skins are soaked in a NaC1 solution
Consider the physical system shown in the figure on page 532. which represents a simplified scenario for the treatment of tumor (cancer) tissue. In this experiment, a slab of living tissue is in
A biosensor is a device that uses a biological mechanism to aid in the detection of a solute (A) within a mixture. Consider the hemispherical-shaped biosensor tip shown in the figure on page 529. The
Ammonia (NH3) in air is being absorbed into water within the enclosed tank shown in the figure (next page). The liquid and gas phases are both well mixed, and mass-transfer occurs only at the exposed
Consider the waste treatment process shown in the figure below. In this process, wastewater containing a dissolved TCE concentration of 50 gmole/m3enters a clarifier, which is essentially a shallow,
Jasmone (molecular formula C11H16O) is a valuable specialty chemical that is obtained from the jasmine plant. A common method of manufacture is to extract the plant material in water, and then use
Wastewater containing solute A at concentration of 1.0 · 10 gmole/m3enters an open tank at a volumetric flow rate of 0.20 m3/min, and exits at the same rate, as shown in the figure below.
Ozone gas (O3, solute A) dissolved in high-purity water is commonly used in wet cleaning processes associated with semiconductor device fabrication. It is desired to produce a liquid water stream
Wastewater containing volatile species A dissolved in the water at a dilute inlet concentration of 0.50 gmole A/m3(cAL,0) is pumped into a well-mixed open holding pond at a volumetric flow rate (v0)
At a particular location in a counter current stripper for removal of solute A from a liquid stream, the mole fraction of solute A in the gas phase is 0.010, and the mole fraction of this species in
An engineer at a pulp mill is considering the feasibility of removing chlorine gas (C12, solute A) from an air steam using water, which will be reused for a pulp bleaching operation. The process will
At a particular location in a counter current gas absorber, the mole fraction of the transferring species (solute A) in the gas phase is 0.030, and the mole fraction of this species in the liquid
A packed-bed tower is used for absorption of sulfur dioxide (SO2) from an air stream using water as the solvent. At one point in the tower, the composition of SO2 is 10% (by volume) in the gas phase,
In a gas€“liquid interface mass-transfer process, the bulk mole fraction composition of solute A in the inert carrier gas is 0.010, and the bulk mole fraction composition of solute A in the
It is desired to recover hexane vapor (solute A) from air using an absorption process. The absorption solvent is a nonvolatile mineral oil, which has a mass density of 0.80 g/cm3and a molecular
A gas–liquid convective mass-transfer process involves the transfer of the industrial contaminant methylene chloride (solute A) between air and water at 20°C and 2.20 atm total system pressure.
Consider an inter phase mass-transfer process for the chlorine dioxide (C1O2)-air-water system at 20°C, where ClO2, gas (solute A) is sparingly soluble in water. At the current conditions of
A wetted wall tower is used to “aerate” water using air at 2.0 atm total system pressure and 20°C. The molar composition of air is 21% O2, 78% N2, and 1% other gases. Let solute A = O2. At
A wetted wall tower is used to “aerate” water using air at 2.0 atm total system pressure and 20°C. The molar composition of air is 21% O2, 78% N2, and 1% other gases. Let solute A = O2. At
The table below presents equilibrium distribution data for four gaseous solutes dissolved in water, using air as the carrier gas:a. Using a spreadsheet to perform the calculations, prepare a graph of
Please refer to Problem 28.16 above. At 600 K and 1.0 atm, under a new velocity for gas flow, the heat-transfer coefficient (h) is now 50 W/m2 · K.a. Compare average mass-transfer coefficient for CO
A thin (1.0-mm-thick) coat of fresh paint has just been sprayed over a 1.5-m by 1.5-m square steel body part, which approximates a flat surface. The paint contains a volatile solvent that initially
Compare the Schmidt number (Sc) tor O2 gas in air at 300 K and 1.0 atm with Sc for dissolved O2 in liquid water at 300 K. Then compare these values for CO2 gas in air at 300 K and 1.0 atm, and
As society searches for technical solutions to global warming, one approach to sequester carbon-dioxide rich greenhouse gases is to capture the CO2within an adsorbent material at high pressure. An
A spherical gel capsule of 0.50 cm diameter is used a drug delivery device. Initially, there is a total drug amount 0.005 mmole uniformly loaded into the gel material. The capsule is ingested, and
Consider a rectangular-shaped gel tablet of thickness 0.125 cm and width 0.50 cm. The edges of the gel tablet are sealed so that diffusion only occurs along the thickness of the tablet. The initial
Consider a rectangular-shaped gel tablet of thickness 0.652 cm and width 1.0 cm loaded with the drug Dramamine. The edges of the gel tablet are sealed so that diffusion of Dramamine occurs only along
A small spherical bead is used as a controlled drug release capsule in the gastrointestinal system (i.e., your stomach). In this particular case, a 0.10-cm diameter bead has a uniform initial
Living cells immobilized within an agarose gel require glucose to survive. An important aspect of the biochemical system design is the effective diffusion coefficient of glucose into the agarose gel
Spherical polymer beads of 3.0 mm (0.3 cm) diameter contain residual solvent from the polymer-casting process. Initially, the bead contains 0.20 wt% of residual solvent uniformly distributed within
A polymer coating of 6.0 mm thickness is cast onto a nonporous flat surface. The coating contains a residual amount of casting solvent, which is uniform at 1.0 wt % within the coating. The mass
A novel metal ion adsorbent material based on the bio polymer poly glucosamine is cast into a gel bead. The amine groups on the bio polymer have a high affinity for transition metal ions at
Consider the porous slab shown in the figure below. Very tiny pores of 20 A diameter run through the 2.0 cm slab in parallel array. This device will ultimately serve as a drug delivery vehicle for a
Consider the cylindrical shaped absorbent material designed to selectively remove solute A from solution. The uptake of solute A through the homogeneous absorbent material is limited by the molecular
We are interested in the diffusion of CO2gas out of a randomly porous adsorbent material slab of 2.0 cm thickness, as shown in the figure below. Initially, the gas space inside the porous material
A common procedure for increasing the moisture content of air is to bubble it through a column of water. The air bubbles are assumed to be spheres, each having a radius of 1.0 mm, and are in thermal
The contamination of water-saturated soils with toxic organic solvents is an important environmental problem. The organic solvents can dissolve into to the water and diffuse through the
A simple experiment is set up to measure the effective diffusion coefficient of blue dextran dye into a rigid agarose gel. An aqueous, well-mixed solution of liquid height 10 cm con taining 1.0 g/L
A “drug patch” is designed to slowly deliver a drug (species A) through the body tissue to an infected zone of tissue beneath the skin. The drug patch consists of a sealed reservoir containing
Hydrogen embrittlement weakens the mechanical strength of cast iron. This phenomenon frequently occurs in cast-iron pressure vessels containing hydrogen (H2) gas. The H2 gas dissolves into the iron
A preheated piece of mild steel, having an initial concentration of 0.20% by weight of carbon, is exposed to a carbonizing atmosphere for 1.0 h. Under the processing conditions, the surface
One step of the manufacturing of silicon solar cells is the molecular diffusion (doping) of elemental phosphorous (P) into crystalline silicon to make an n-type semiconductor. This Pdoped layer needs
In the fabrication of a p-type semiconductor, elemental boron is diffused a small distance into a solid crystalline silicon wafer. The boron concentration within the solid silicon deter mines
Aluminum is the primary conductor material for fabrication of microelectronic devices. Consider the composite thin film shown in the figure below. A thin film of solid aluminum is sputter-coated onto
The transient concentration profile cA(z,t) resulting from transient one-dimensional diffusion in a slab under conditions of negligible surface resistance is described by equation (27.16). Use this
Please refer to example 5 of this chapter. Estimate the total transfer rate of solute A from the mass-transfer system shown in Figure 26.14, in units of gmole/h. As part of this analysis, consider
In the distillation of a benzene/toluene mixture, a vapor richer in the more volatile component benzene is produced from the benzene/toluene liquid solution. Benzene is transferred from the liquid to
Recall from example 3, Chapter 25, that the differential model for the radial concentration profile of dissolved oxygen within one cylindrical engineered tissue bundle (Figure 25.8) iswith boundary
Many bio catalytic reactions are carried out with living cells as the bio catalyst. In some processes, the cells are immobilized within an agarose gel. However, living cells uniformly distributed
Carbon dioxide (CO2) from waste sources is a sustain able feed stock for chemicals production if new technologies can be developed to carry out the reduction of CO2, the most oxidized form of carbon,
The pesticide Atrazine (C8H14C1N5, mol wt. 216 g/ mol) degrades in soil by a first-order reaction process. Consider the situation shown in the figure below, where there is a spill of solid Atrazine
A bio film reactor with a well-mixed liquid phase shown below will be used to treat wastewater contaminated with trichioroethylene (TCE) at a concentration 0.25 mg/L (1.9 mmole/m3, MTCE = 131.4
A bio film reactor with a well-mixed liquid phase shown below will be used to treat wastewater contaminated with trichioroethylene (TCE) at a concentration 0.25 mg/L (1.9 mmole/m3, MTCE= 131.4
Consider a spherical gel bead containing a bio catalyst uniformly distributed within the gel. Within the gel bead, a homogeneous, first-order reaction A †’k1D is promoted by the bio
A “bio film” (component B) coats the surface of a nonporous inert sphere. The diameter of the nonporous inert core is 4.0 mm, and the overall diameter of the spherical bio film particle is 8.0
The €œdrug patch€ shown in the figure in the next column releases a water-soluble epidermal growth factor (species A) to repair a specific region of wounded tissue on the human
A flat surface containing many parallel pores is clogged with €œcoke€ from a manufacturing process, as shown in the figure below. Pure oxygen gas (O2) at high temperature is used
The Arnold Diffusion Cell shown in Figure 26.5 is a simple device used to measure gas-phase diffusion coefficients for volatile substrates in air. In the present experiment, liquid acetone is loaded
The data provided in Figure 26.7 are based on the diffusion of O2into SiO2formed from the oxidation of (100) crystalline silicon at 1000°C. Estimate the diffusion coefficient of O2in SiO2formed
A cylindrical graphite rod (pure solid carbon, density 2.25 g/cm3) of length 25 cm and initial diameter of 2.0 cm is inserted into a flowing air stream at 1100 K and 2.0 atm total system pressure.
€œMicrovia€ are microscopic passages between two thin films on a microelectronic device. Often, microvia are filled with a conductive metal to make a microscopic conductor for
Consider the timed drug release pill shown in the figure below. The pill is ingested into the stomach. The pill is a slab of 0.36 cm per side, which has an array of 16 cylindrical pores in it. Each
The mass transfer device shown in the figure at the top of the next column is used to carry out the controlled release of a vapor-phase pheromone drug used in pest control. The solid drug sublimes at
Consider a hemispherical droplet of liquid water residing on a flat surface, as shown in the figure on page 526. Still air surrounds the droplet. At an infinitely long distance from the gas film, the
A spherical ball of solid, nonporous naphthalene, a “mothball,” is suspended in still air. The naphthalene ball slowly sublimes, releasing the naphthalene vapor into the surrounding air by
Tubular membranes of silicone rubber can be used for €œbubble less€ aeration of water. A cross section of the tube is shown in the figure (right-hand column). Pure oxygen (O2)
An open well contains water contaminated with volatile benzene at the bottom of the well, with dimensions shown in the figure on page 525. The concentration of dissolved benzene in the water is 156
A cell mono layer used in a tissue engineering scaffold adheres onto the top surface of a silicone rubber (polymer) sheet of 0.10 cm thickness, as shown in the figure below. The rectangular sheet is
A porous €˜water vapor barrier€ is placed over the tissue implant shown in the figure in the next column. The purpose of the porous €œwater vapor barrier€ is
We are interested analyzing the diffusion processes associated with the treatment of cancer cells. Consider the experimental system shown in the figure on page 524. A hemispherical clump of cancer
Consider the biosensor device shown in the figure in the next column. The biosensor is designed to measure the concentration of solute A in the well-mixed liquid phase. At the base of the device is

Showing 100 - 200 of 974