Engineering, 31.03.2020 19:31, jerenasmith8

The permeability coefficient of a type of small gas molecule in a polymer is dependent on absolute temperature according to the following equation:

PM=PM0exp(−Qp/RT)

where PM0 and Qp are constants for a given gas-polymer pair. Consider the diffusion of water through a polystyrene sheet 30 mm thick. The water vapor pressures at the two faces are 20 kPa and 1 kPa, which are maintained constant. Compute the diffusion flux [in(cm^3 STP)/cm^2⋅s] at 350 K? For this diffusion system,

PM0=9.0×10^−5(cm^3 STP)(cm)/cm^2. s. Pa
Qp=42,300J/mol

Assume a condition of steady-state diffusion.

Answers: 1

Show answers

Other questions on the subject: Engineering

Engineering, 03.07.2019 15:10, brooklyn674

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

Answers: 3

continue

Engineering, 04.07.2019 16:10, Arealbot

The force on a cutting tool are 2600n vertically downward and 2100 horizontal. determine the resultant force acting on the tool and the angle at which it acts.

Answers: 1

continue

Engineering, 04.07.2019 18:10, koolgurl2003

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

Answers: 1

continue

Engineering, 04.07.2019 18:10, settasav9641

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

Answers: 3

continue

Do you know the correct answer?

The permeability coefficient of a type of small gas molecule in a polymer is dependent on absolute t...