@article {157,
	title = {Modeling and estimation of production rate for the production phase of non-growth associated high cell density processes},
	journal = {Bioprocess and Biosystems Engineering},
	volume = {38},
	year = {2015},
	pages = {1903-1914},
	abstract = {This paper addresses the estimation of the specific production rate of intracellular products and the modeling of the bioreactor volume dynamics in high cell density fed-batch reactors.
In particular, a new model for the bioreactor volume is proposed, suitable to be used in high cell density cultures where large amounts of intracellular products are stored. Based on the proposed volume model, two forms of a high order sliding mode observer are proposed. Each form corresponds to the cases with residual biomass concentration or volume measurement respectively. The observers achieve finite time convergence and robustness to process uncertainties as the kinetic model is not required. Stability proofs for the proposed observer are given. The observer algorithm is assessed numerically and experimentally.},
	keywords = {Bioplastics, Estimation, high cell density, Observer, PHB, Sliding mode, Software sensor, volume model},
	doi = {10.1007/s00449-015-1430-7},
	author = {Jamilis, Mart{\'\i}n and Garelli, Fabricio and Mozumder, MSI and Casta{\~n}eda, Teresita and De Battista, Hern{\'a}n}
}
@article {117,
	title = {Specific growth rate observer for the growing phase of a Polyhydroxybutyrate production process},
	journal = {Bioprocess and Biosystems Engineering},
	volume = {38},
	year = {2015},
	pages = {557-567},
	abstract = {<p>This paper focuses on the specific growth rate estimation problem in a <em>Polyhydroxybutyrate</em> bioplastic production process by industrial fermentation. The kinetics of the process are unknown and there are uncertainties in the model parameters and inputs. During the first hours of the growth phase of the process, biomass concentration can be measured online by an optical density sensor, but as cell density increases this method becomes ineffective and biomass measurement is lost. An asymptotic observer is developed to estimate the growth rate for the case without biomass measurement based on corrections made by a pH control loop. Furthermore, an exponential observer based on the biomass measurement is developed to estimate the growth rate during the first hours, which gives the initial condition to the asymptotic observer. Error bounds and robustness to uncertainties in the models and in the inputs are found. The estimation is independent of the kinetic models of the microorganism. The characteristic features of the observer are illustrated by numerical simulations and validated by experimental results.</p>
},
	keywords = {Bioplastics, Estimation, Observer, PHB, Software sensor},
	issn = {1615-7591},
	doi = {10.1007/s00449-014-1295-1},
	url = {http://dx.doi.org/10.1007/s00449-014-1295-1},
	author = {Jamilis, Mart{\'\i}n and Garelli, Fabricio and Mozumder, Md Salatul Islam and Volcke, Eveline and De Battista, Hern{\'a}n}
}
