function xprime=input_rectifier(t,X) 
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%%%%% Program written by Stathis Skouras, August 2003 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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% Number of stages in the rectifying section: 
Nr=51;
% Total number of 'stages'  
NT=Nr+2;

% Inputs
VB=5;                                  % Boilup (kmol/hr)
L0=VB;                                 % Nominal liquid flows in both sections of the column (kmol/hr)

% L-Controllers gains, integral time and level set-point  
Kc1=0.41; 
Tsp1=72.2;

% Precaution so as condenser and middle vessel do not run empty
Hmin=0.035;                            % Minimum liquid holdup in condenser and middle vessel   

% Store all inputs and disturbances
U(1)=VB; U(2)=L0; U(3)=Kc1; U(4)=Tsp1; U(5)=Hmin; 
xprime=rectifier(t,X,U);
t