ABSTRACT
We apply numerical optimal control methods to an existing algae growth model with the aim to determine the best performance of the model under known conditions using a variety of decision variables. We transform the system of differential algebraic equations in the existing model to a system of ordinary differential equations which introduces dynamics for average light intensity and chlorophyll. In addition, we allow for variable nitrogen concentration of the inflow as well as variable initial nitrogen concentration of the raceway. Our main focus is on optimizing of the production of lipids. We calculate both open and closed loop optimal controllers and test their robustness. Finally, we also consider raceway depth as a decision variable. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:107-119, 2018.
Subject(s)
Chlorella/growth & development , Chlorophyll/chemistry , Microalgae/growth & development , Biomass , Chlorella/genetics , Chlorella/radiation effects , Chlorophyll/genetics , Chlorophyll/radiation effects , Hydrodynamics , Kinetics , Light , Lipids/chemistry , Microalgae/genetics , Microalgae/radiation effects , Nitrogen/chemistryABSTRACT
Cardiac syndrome X (CSX), or angina with no flow-limiting stenosis on coronary angiogram, has been regarded as a condition with an excellent prognosis despite variable symptomatic improvement. Newer data show that patients with CSX with endothelial dysfunction have an increased risk for future adverse cardiac events. Current hypotheses of CSX pathophysiology emphasize a dysfunctional vascular endothelium that leads to microvascular ischemia. Treatments that target improving endothelial function, such as statins, angiotensin-converting enzyme inhibitors, estrogen, and lifestyle modification, are promising additions to treatment regimens for CSX. The goal of this article is to provide information for improved diagnosis, risk stratification, and therapy for the population with CSX.