Asheet of bcc iron 2.0-mm thick was exposed to a carburizing atmosphere on one side and a decarburizing atmosphere on the other side at 725°c. after having reached steady state, the iron was quickly cooled to room temperature. the carbon concentrations at the two surfaces were determined to be 0.012 and 0.0074 wt%. calculate the diffusion coefficient if the diffusion flux is 2.2 × 10-8 kg/m2-s, given that the densities of carbon and iron are 2.25 and 7.87 g/cm3, respectively.

The diffusion coefficient is 1.22 * 10 ^-10 m²/s

Explanation:

Step 1: Data given

A sheet of BCC iron 2.0-mm thick

The diffusion flux is 2.2 * 10^-8 kg/m²*s

Density of Carbon = 2.25 g/cm³

Density of Iron = 7.87 g/cm³

Step 2: Define the formula for the carbon concentrations

C"c = Cc / ((Cc/rc)+ (Cfe/rfe))

with C"c = The concentration carbon

with Cc = The % concentration

with rc = The density of Carbon

with Cfe = The % concentration iron

with rfe = the density of Iron

Step 3: For 0.012 wt% C

C"c = 0.012 / ((0.012/2.25)+(99.988/7.87)) *10³

C"c = 0.944 kg C/ m³

Step 4: For 0.0074 wt% C

C"c = 0.0074 / ((0.0074/2.25)+(99.9926/7.87)) * 10³

C"c = 0.5823 kg C/m³

Step 5: Calculate the diffusion coefficient

D = - (diffusion flux)* ((- thickness)/(0.012 wt% C - 0.0074 wt% C)

D = -(2.2 *10^-8 ) *(( -2*10^-3)/(0.944 - .5823)

D = 1.22 * 10 ^-10 m²/s

The diffusion coefficient is 1.22 * 10 ^-10 m²/s

smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. those muscles push materials like food or blood through organs. unlike skeletal muscle, smooth muscle can never be under your control.