ODE Solver Algorithm |POLVER05_1
d(y)/d(W) =    -alpha/(2*y)    #
d(a)/d(W) =   -kd*a^2*Pb/Us   #
d(X)/d(W) =   -raprime/Fao   #
Us =   2   #
Pao =  20  #
Fao =   10   #
kd =   .75   #
Ka =   1.5   #
k =   .1   #
alpha =  .0019  #
Pb =   Pao*X*y   #
Pa =   Pao*(1-X)*y   #
raprime =   -a*k*Pa/(1+Ka*Pa)   #
W(0)=0
y(0)=1
a(0)=1
X(0)=0
W(f)=500