1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Pie
3 years ago
15

Consider the diffusion of water vapor through a polypropylene (PP) sheet 1 mm thick. The pressures of H2O at the two faces are 3

kPa and 9 kPa, which are maintained constant. Assuming conditions of steady state, what is the diffusion flux, in [(cm3 STP)/cm2-s], at 298 K
Engineering
1 answer:
Neko [114]3 years ago
7 0

Answer:

\boxed{0.000000266 \frac {cm^{3}.STP}{cm^{2}.s}}

Explanation:

Diffusion flux of a gas, J is given by

J=P_m\frac {\triangle P}{\triangle x} where P_m is permeability coefficient, \triangle P is pressure difference and x is thickness of membrane.

The pressure difference will be 10,000 Pa- 3000 Pa= 7000 Pa

At 298 K, the permeability coefficient of water vapour through polypropylene sheet is 38\times 10^{-13}(cm^{3}. STP)(cm)/(cm^{2}.s.Pa)

Since the thickness of sheet is given as 1mm= 0.1 cm then

J=38\times 10^{-13}(cm^{3}. STP)(cm)/(cm^{2}.s.Pa)\times \frac {7000 pa}{0.1cm}=0.000000266 \frac {cm^{3}.STP}{cm^{2}.s}

Therefore, the diffusion flux is \boxed{0.000000266 \frac {cm^{3}.STP}{cm^{2}.s}}

You might be interested in
Which statement best describes how a hearing aid works?
Verizon [17]

The following statement best describes how a hearing aid works, An implant bypasses parts of the cochlea and sends messages to the brain, where they are then recognized as sound.

Explanation:

  • The hearing aid works as An implant bypasses parts of the cochlea and sends messages to the brain, where they are then recognized as sound.
  • A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss.
  • Modern devices uses all sophisticated digital signal processing to try and improve the speech understanding, intelligibility and comfort for the user, such as signal processing
  • Almost all hearing aids in use in the US are digital hearing aids Devices similar to hearing aids include cochlear implant.
  • Early devices, such as ear trumpets or ear horns, were the passive amplification cones which were designed to gather the sound energy and directly goes into the ear canal.
  • Most common issues with hearing aid fitting and use are the occlusion effect, loudness recruitment, and understanding speech in noise.

4 0
3 years ago
Which of the following is not a function of the cooling system
Pie

Answer:

hola soy dora

Explanation:

5 0
2 years ago
A ________ can be installed in a cast-iron block to repair a worn or cracked cylinder. Question 24 options:
VLD [36.1K]

Answer:

Cylinder sleeve

Explanation:

7 0
3 years ago
Water at atmospheric pressure boils on the surface of a large horizontal copper tube. The heat flux is 90% of the critical value
masya89 [10]

Answer:

The tube surface temperature immediately after installation is 120.4°C and after prolonged service is 110.8°C

Explanation:

The properties of water at 100°C and 1 atm are:

pL = 957.9 kg/m³

pV = 0.596 kg/m³

ΔHL = 2257 kJ/kg

CpL = 4.217 kJ/kg K

uL = 279x10⁻⁶Ns/m²

KL = 0.68 W/m K

σ = 58.9x10³N/m

When the water boils on the surface its heat flux is:

q=0.149h_{fg} \rho _{v} (\frac{\sigma (\rho _{L}-\rho _{v})}{\rho _{v}^{2} }  )^{1/4} =0.149*2257*0.596*(\frac{58.9x10^{-3}*(957.9-0.596) }{0.596^{2} } )^{1/4} =18703.42W/m^{2}

For copper-water, the properties are:

Cfg = 0.0128

The heat flux is:

qn = 0.9 * 18703.42 = 16833.078 W/m²

q_{n} =uK(\frac{g(\rho_{L}-\rho _{v})     }{\sigma })^{1/2} (\frac{c_{pL}*deltaT }{c_{fg}h_{fg}Pr  } \\16833.078=279x10^{-6} *2257x10^{3} (\frac{9.8*(957.9-0.596)}{0.596} )^{1/2} *(\frac{4.127x10^{3}*delta-T }{0.0128*2257x10^{3}*1.76 } )^{3} \\delta-T=20.4

The tube surface temperature immediately after installation is:

Tinst = 100 + 20.4 = 120.4°C

For rough surfaces, Cfg = 0.0068. Using the same equation:

ΔT = 10.8°C

The tube surface temperature after prolonged service is:

Tprolo = 100 + 10.8 = 110.8°C

8 0
3 years ago
In response to the market revolution:the legal system worked with local governments to find better ways to regulate entrepreneur
Nataliya [291]

Answer:

Local judges protected businessmen from paying property damages associated with factory construction and from workers seeking to unionize.

Explanation:

The Market Revolution is the name given to change in the economy that occurred in the 19th century. This drastic change led to various important changes in the United States and across the world. During this period, capitalism became more entrenched and society became, for the first time, predominantly capitalist. This gave businessmen great power, as they played an increasingly important role when it came to economic growth. The power that they had influenced society deeply, including legislation. Judges often protected businessmen from paying property damages that were associated with their business enterprises. Moreover, workers had few rights and protections, and judges prevented them from unionizing.

5 0
3 years ago
Other questions:
  • Water flows through two smooth pipes with the same diameter and length as shown below. ipe is twice that through the first-pipe.
    12·1 answer
  • Explain what entropy is in relation to the second law of thermodynamics?
    9·1 answer
  • Talc and graphite are two of the lowest minerals on the hardness scale. They are also described by terms like greasy or soapy. B
    14·1 answer
  • I study to get good grades because my parents want to send me to the college of my choice.” This is an a. Intrinsic motivational
    6·2 answers
  • Airplanes typically have a Pitot-static probe located on the underside that measures relative wind speed as the airplane flies.
    6·1 answer
  • Add my sc please?.<br><br> kindacracked
    12·2 answers
  • Please answer i dont understand and dont know the answer​
    14·1 answer
  • What do Engineering Systems achieve?
    8·1 answer
  • Water flow enters a pipe at a velocity of 1m/s. The pipe inlet is 10cm. The pipe outlet is 6cm. 1. Determine the velocity of the
    9·1 answer
  • Question 2: (a) In your own words, clearly distinguish and differentiate between Ethics in Engineering and Ethics in Computing (
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!