11 research outputs found
Optimization of pH induced flocculation of marine and freshwater microalgae via central composite design
Effective biomass harvesting of marine diatom Chaetoceros muelleri by chitosan-induced flocculation, preservation of biomass, and recycling of culture medium for aquaculture feed application
Comparative Study on the Harvesting of Marine Chlorella vulgaris Microalgae from a Dilute Slurry Using Autoflocculation-Sedimentation and Electrocoagulation-Flotation Methods
Evaluation of Freshwater Microalgal Isolates for Growth and Oil Production in Seawater Medium
Optimal strategies for bioremediation of nitrate-contaminated groundwater and microalgae biomass production
Microalgae Chlorella vulgaris biomass harvesting by natural flocculant: effects on biomass sedimentation, spent medium recycling and lipid extraction
Harvesting a remote renewable resource
Upmann T, Behringer S. Harvesting a remote renewable resource. Theoretical Ecology. 2020;13(4):459-480.**Abstract**
In standard models of spatial harvesting, a resource is distributed over a continuous domain with an agent who may harvest everywhere all the time. For some cases though (e.g., fruits, mushrooms, algae), it is more realistic to assume that the resource is located at a fixed point within that domain so that an agent has to travel in order to be able to harvest. This creates a combined travelling–and–harvesting problem where slower travel implies a lower travelling cost and, due to a later arrival, a higher abundance of the resource at the beginning of the harvesting period; this, though, has to be traded off against less time left for harvesting, given a fixed planning horizon. Possible bounds on the controls render the problem even more intricate. We scrutinise this bioeconomic setting using a two-stage optimal control approach, and find that the agent economises on the travelling cost and thus avoids to arrive at the location of the resource too early. More specifically, the agent adjusts the travelling time so as to be able to harvest with maximum intensity at the beginning and the end of the harvesting period, but may also find it optimal to harvest at a sustainable level, where the harvesting and the growth rate of the stock coincide, in an intermediate time interval