You are asked to determine the concentration of a diffusing gas at a given depth on a metal surface after a given time. If you know the temperature of the metal, the surface concentration of the gas, and the diffusion coefficient, describe how you would approach this problem.

I am trying to calculate surface concentration: gamma = -(1/RT)(dy/d(ln(C)) and express in units of mol/m^2. However I cannot seem to get the units right. I am unsure which R gas constant units to use. I need to convert the (dy/d(ln(C)) units: (dyn/cm)(mol/L) into terms of mol/m^2. And the same for the R gas constant units.

A thermal evaporator is used to deposit aluminum. The aluminum charge is maintained at a uniform temperature of 1100 o C. If the the vapor pressure of aluminum is about 1x10-3 torr at that temperature, calculate the evaporation rate of aluminum?

Thermal fluid mechanics Detailed solution With an understanding of the laws of the subject

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.

Many biological tissues have layers with different extracellular matrix components and different orientations of these components. As a result, diffusion coefficients vary from region to region. Even within a region, the diffusion coefficient depends on the direction of transport, a situation know as anisotropy. Consider the steady-state, one-dimensional diffusion of a molecule across an artery wall consist of an acellular phase and a cellular phase. There are no chemical reactions. An example of such a tissue is an elastic artery that contains a layer of smooth muscle cells of thickness L1 and an elastic lamina of thickness L2. (Actually, an artery consists of repeating layers of elastin and smooth muscle cells, but for the present discussion, consider a single layer of each.) The molecule diffusion coefficients of the two layers are Di, 1 and Di, 2 respectively. The concentration of the molecule at the lumen surface (x = 0) is C0, and the concentration at x = L1 + L2 = L is CL.  L1 =…

The diffusion coefficients for carbon in nickel are given at two temperatures: T(°C) D (m²/s) (a) Determine the value of Do. i (b) Determine the value of Qd. i i kJ/mol (c) What is the magnitude of D? at 810°C. 600 700 ! m²/s (Use scientific notation.) 5.5 x 10-14 3.9 × 10-13 m²/s (Use scientific notation.)

Solve with me time 40 minutes