function [ fv, sv ] = Clarifier_Disturbance( t, ifv, isv )
%
fv = ifv;
sv = isv;
dist = 1;
%
% Figure 4.20a disturbance
%
if dist == 1,
  if t >= 1.999,
    fv(1) = 700;
    fv(2) = 500;
  end;
  if t >= 2.999, 
    fv(1) = 450;
    fv(2) = 250;
  end;
end;
%
% Figure 4.20b disturbance
%
if dist == 2,
  if t >= 0.999,
    fv(2) = 350;
    fv(3) = 100;
  end;
  if t >= 3.999,
    fv(2) = 250;
    fv(3) = 200;
  end;
end;
%
return;
%-----------------------------------------------------
