Modelling of general biotechnological processes

A general biotechnological process is modelled by a finite dimensional ordinary differential equation. The stoichiometry is only modelled qualitatively. It is shown that the usual biochemically motivated assumptions are not sufficient to guarantee boundedness of the solution. To overcome this, the concept of non-cyclic biotechnological processes is introduced. Loosely speaking it means that the process does not contain any reaction loop. The assumption of non-cyclicity replaces the common assumption of Conservation of Mass. An algorithm is presented so that after finitely many steps it is decided whether a process is non-cyclic or cyclic. Non-cyclicity is also characterised in terms of an echelon matrix derived from the stoichiometric matrix via permutations of columns and rows

From pole to pole : 33 years of physical oceanography onboard R/V Polarstern

Measuring temperature and salinity profiles in the world's oceans is crucial to understanding ocean dynamics and its influence on the heat budget, the water cycle, the marine environment and on our climate. Since 1983 the German research vessel and icebreaker Polarstern has been the platform of numerous CTD (conductivity, temperature, depth instrument) deployments in the Arctic and the Antarctic. We report on a unique data collection spanning 33 years of polar CTD data. In total 131 data sets (1 data set per cruise leg) containing data from 10 063 CTD casts are now freely available at doi: 10.1594/PANGAEA.860066. During this long period five CTD types with different characteristics and accuracies have been used. Therefore the instruments and processing procedures (sensor calibration, data validation, etc.) are described in detail. This compilation is special not only with regard to the quantity but also the quality of the data -the latter indicated for each data set using defined quality codes. The complete data collection includes a number of repeated sections for which the quality code can be used to investigate and evaluate long-term changes. Beginning with 2010, the salinity measurements presented here are of the highest quality possible in this field owing to the introduction of the OPTIMARE Precision Salinometer.Peer reviewe

Narrowing the uncertainty for deep-ocean injection efficiency

Publisher Summary The chapter proposes a basic ground rule for future studies of ocean injection efficiency: to be credible they must also demonstrate the associated model's skill in simulating the global inventory of GFG-11 and the global mean for radiocarbon in the deep ocean. A model that performs well in regards to both those constraints will be more likely to simulate reasonable global injection efficiencies. Nonetheless, efficiencies for a given injection site in coarse resolution models could be biased. For instance, the majority of injection sites will be located on eastern or western boundaries, which have known problems in coarse resolution models. Furthermore, coarse-resolution grids are unable to resolve important subgrid-scale processes (e.g., eddies, boundary currents, convection). Properly accounting for these processes may affect large-scale transport and could alter model predictions of CO2 sequestration efficiency. Although, global-scale ocean general circulation models are now becoming available which do resolve these processes, their high resolution means that they can only be integrated for relatively short periods, a few decades at most

Physical oceanography on board of POLARSTERN (1983-11-22 to 2016-02-14)

Measuring temperature and salinity profiles in the world's oceans is crucial to understanding ocean dynamics and its influence on the heat budget, the water cycle, the marine environment and on our climate. Since 1983 the German research vessel and icebreaker Polarstern has been the platform of numerous CTD (conductivity, temperature, depth instrument) deployments in the Arctic and the Antarctic. We report on a unique data collection spanning 33 years of polar CTD data. In total 131 data sets (1 data set per cruise leg) containing data from 10 063 CTD casts are now freely available. During this long period five CTD types with different characteristics and accuracies have been used. Therefore the instruments and processing procedures (sensor calibration, data validation, etc.) are described in detail. This compilation is special not only with regard to the quantity but also the quality of the data - the latter indicated for each data set using defined quality codes. The complete data collection includes a number of repeated sections for which the quality code can be used to investigate and evaluate long-term changes. Beginning with 2010, the salinity measurements presented here are of the highest quality possible in this field owing to the introduction of the OPTIMARE Precision Salinometer