[Ecell-users] Fwd: Help!

[sushil r. <ron...@gm...>]

---------- Forwarded message ----------
From: sushil ronghe <ron...@gm...>
Date: Dec 8, 2007 6:12 PM
Subject: Help!
To: e-c...@e-...


Dear all,

I am modeling a reaction with E-Cell where reagent (R)
is added to the system say M (infinitely).
Rate of addition of R to M is known.

The rate of conversion of R to R2 is given.
I want to calculate the concentration of R
In M whose volume is also given.
Concentration in M is calculated as

 C = [Concentration of R in M] / Volume of M;

and Concentration of R in M is calculated as
 - [Rate of Conversion of R to R2] + [Rate of Addition of R]

I want to simulate this equation:

 d/dt [M] =  - [Rate of Conversion of R to R2] + [Rate of Addition of R]

My Em file looks like this.I am not very much sure about the selection
of stepper
and process.

Constant are as fallows :

 [Concentration of R in M]  (initially) =0;
 [Rate of Conversion of R to R2] = 7.2
 [Rate of addition]= 600


>  Stepper ODE45Stepper( DT_1 )
> {
>        StepInterval 0.01;
> }
>
>
> System System( / ){
>    StepperID DT_1;
>
>    Process ExpressionFluxProcess(C0){
>        Expression "M0.MolarConc/14";
>        VariableReferenceList [C0:./compartment:C 1]
> [M0:./compartment:M];
>        }
>
>    Process ExpressionFluxProcess(M0){
>        Expression "-(7.2*C0.MolarConc) +R0.Value";
>        VariableReferenceList [M0:./compartment:M -1]
> [C0:./compartment:C][R0:./compartment:R];
>        }
>    }
> System System( /compartment ){
>    StepperID DT_1;
>
>    Variable Variable(Size){
>        Value 1;
>        Fixed 1;
>    }
>
>    Variable Variable(M){
>        Value 0.0;
>        }
>
>    Variable Variable(R){
>        Value 600;
>        }
>
>    Variable Variable(C){
>        Value 0.0;
>        }
> }
>
I am expecting a graph starting from 0 and reaching 600,

what i am getting is Concentration of C is dropping and also
the simulation is stopped because of infinite numbers.

Any help is really appreciated



-- 
********************************
sushil ronghe
*********************************


-- 
********************************
sushil ronghe
*********************************