Problem Four: $(35$ points$)$

In water desalination plants, sult fouling in the units is a major problem that sornetimes

require acid cleaning. To mitigute such issue some chemiculs are pumped into the system.

As an assigned engineer you want to study the previous year behavior which can expressed

by:

Salt fouling in unit A: $S_c=*exp(-\frac{t}{10})t+37t+{10}^3$exp$(-t)[ppm]$

Chemical pumped into unit $A$:$C_c=1**{10}^5=(1-$exp$(-\frac{t}{30}))[$mgal$/$day$]$

Where $=20**{10}^{3}ppm$

a$)$ Use MATLAB to create a plot displaying toth the salt concentration $($using cross$-$

shuped, dotted line$)$ and the chemical concentration $($using u red, dashed line$).$ Plot

the function in the time interval $1t300$ days with $t-1$ day. Include labels,

grid, and legend.

b$)$ Use subplot to generate a side$-$by$-$side graph of $S_c$ versus $t$ and $C_c$ versus $f.$ Add

titles to each subplot.