(1)	$c\left(x,t\right)=c_0=0$	for $-\frac{d}{2}<x<\frac{d}{2}$	at $t=0$
(2)	$c\left(x,t\right)=c_{\infty }$	for $x=\frac{d}{2} {\displaystyle \cap } x=-\frac{d}{2}$	at $0<t<t_{\infty }$
(3)	$c\left(x,t\right)=c_{\infty }$	for $-\frac{d}{2}<x<\frac{d}{2}$	at $t=t_{\infty }$