Do I have to wait till the system reaches the OCV before adding another resistor? or do I change resistors one after the other without leaving time between them?
Thanks a lot.
Do I have to wait for the cell to reach its maximum OCV before start adding resistors for calculations?
After using resistors, I don't wait for the cell to go back to its OCV, right?
And thanks again. I really needed this info.
Last question, please, Sir .. Do I have to develop trend lines for the polarization curve?
Thanks in advance. And sorry for my so many questions.
Thanks, Dr. Ravinder.
Fatemah, I think because you plot curves against current, and current increases as you decrease resistance. (I is inversely proportional with R).
Menicucci et al. (2005) pointed out some undesirable practices, such as recording the maximum current obtained by the cell when connecting it to a resistance as an indication of its performance, instead of the steady-state current that is often a degree of magnitude lower. Often the data about the values of the used resistance is minimal, or even non-existent, making much of the data non-comparable across all studies. This makes extrapolation from standardized procedures difficult if not impossible. The voltage drops need to be taken only when pseudo-steady-state conditions have been established. The establishment of this pseudo-steady state may take several minutes, depending on the system and the external resistance. Care should however be taken not to wait too long for the establishment of the pseudo-steady state as this would result in change in substrate concentration in the reactor due to substrate demand at the anode (unless continuously replenished). This will in turn affect the incidence of substrate/products mass transfer over voltage and current (Logan et al., 2006).
Again, I want to add that is always better to start with the highest resistor and continue in decreasing order as starting with the smallest resistor may result in very large polarization loss and thus the MFC may not be able to drop maximum voltage across the higher resistors
Actually, yes I am not replenishing substrate.
I read what was mentioned in professor Logan's article about the pseudo-steady state. However, what Dr. Ravinder said is convenient for me, based on this article:
http://www.sciencedirect.com/science/article/pii/S1388248110004765
I didn't get your point, Mr. Simeon, how could starting with the smallest resistor result in polarization loss? will you explain this point, please?
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