scholarly journals Kinetic modeling of light limitation and sulfur deprivation effects in the induction of hydrogen production withChlamydomonas reinhardtii: Part I. Model development and parameter identification

2009 ◽  
Vol 102 (1) ◽  
pp. 232-245 ◽  
Author(s):  
Swanny Fouchard ◽  
Jérémy Pruvost ◽  
Benoit Degrenne ◽  
Mariana Titica ◽  
Jack Legrand
Keyword(s):  
Hydrogen Production ◽  
Parameter Identification ◽  
Kinetic Modeling ◽  
Model Development ◽  
Light Limitation ◽  
Sulfur Deprivation

scholarly journals Physical Parameter Identification Algorithm Modeling for Complex Microsystem via Triangulation Functions

2018 ◽  
Vol 7 (4.36) ◽  
pp. 962
Author(s):  
Elena N. Meshcheryakova ◽  
. .
Keyword(s):  
Parameter Identification ◽  
Physical Parameter ◽  
Delaunay Triangulation ◽  
Model Development ◽  
Physical Object ◽  
Identification Algorithm ◽  
Classification Analysis ◽  
Advantages And Disadvantages ◽  
Object Parameters ◽  
D Model

This article describes the possibility of triangulation function use for the classification, analysis and identification of complex microsystem physical object parameters. They analyzed the existing methods and identification algorithms, their advantages and disadvantages are highlighted. The existing methods of triangulation are considered, the possibility of Delaunay triangulation is described for surfactant signal 3-D model development and analysis. They developed the algorithm to identify the state of an object using the triangulation function that takes into account the change of node coordinates and the length of the triangulation grid edges. They presented the visual UML model. The conclusions are drawn about the possibility of triangulation function use for the analysis of complex microsystem state.  

Activated sludge modelling: past, present and future

2006 ◽  
Vol 53 (3) ◽  
pp. 111-119 ◽  
Author(s):  
W. Gujer
Keyword(s):  
Population Dynamics ◽  
Activated Sludge ◽  
Parameter Identification ◽  
Model Development ◽  
Model Complexity ◽  
Computational Power ◽  
Practical Limit ◽  
Simulation Parameter ◽  
Mc Simulation

Model complexity in activated sludge modelling has increased over 30 years in parallel with the computational power of computers. Today, the complexity of biokinetics has reached a practical limit. Future advances may be in the direction of enhanced spacial resolution (CFD, single organisms) respectively, in repetitive computations (MC simulation, parameter identification). Further model development may be in niches such as population dynamics, micropollutants, etc.

scholarly journals Using expert knowledge to increase realism in environmental system models can dramatically reduce the need for calibration

2013 ◽  
Vol 10 (12) ◽  
pp. 14801-14855 ◽  
Author(s):  
S. Gharari ◽  
M. Hrachowitz ◽  
F. Fenicia ◽  
H. Gao ◽  
H. H. G. Savenije
Keyword(s):  
Parameter Identification ◽  
Expert Knowledge ◽  
Model Development ◽  
Distributed Model ◽  
Hydrological Process ◽  
Rainfall Runoff ◽  
Lumped Model ◽  
Knowledge Based ◽  
Runoff Modeling ◽  
Functional Units

Abstract. Conceptual environmental systems models, such as rainfall runoff models, generally rely on calibration for parameter identification. Increasing complexity of this type of model for better representation of hydrological process heterogeneity typically makes parameter identification more difficult. Although various, potentially valuable, strategies for better parameter identification were developed in the past, strategies to impose general conceptual understanding regarding how a catchment works into the process of parameterizing a conceptual model has still not been fully explored. In this study we assess the effect of imposing semi-quantitative, relational expert knowledge into the model development and parameter selection, efficiently exploiting the complexity of a semi-distributed model formulation. Making use of a topography driven rainfall-runoff modeling (FLEX-TOPO) approach, a catchment was delineated into three functional units, i.e. wetland, hillslope and plateau. Ranging from simplicity to complexity, three model set-ups, FLEXA, FLEXB and FLEXC have been developed based on these functional units. While FLEXA is a lumped representation of the study catchment, the semi-distributed formulations FLEXB and FLEXC introduce increasingly more complexity by distinguishing 2 and 3 functional units, respectively. In spite of increased complexity, FLEXB and FLEXC allow modelers to compare parameters as well as states and fluxes of their different functional units to each other. Based on these comparisons, expert knowledge based, semi-quantitative relational constraints have been imposed on three models structures. More complexity of models allows more imposed constraints. It was shown that a constrained but uncalibrated semi-distributed model, FLEXC, can predict runoff with similar performance than a calibrated lumped model, FLEXA. In addition, when constrained and calibrated, the semi-distributed model FLEXC exhibits not only higher performance but also reduced uncertainty for prediction, compared to the calibrated, lumped FLEXA model.

scholarly journals Optimization of Hydrogen Gas Production Conditions from Egyptian Chlamydomonas Sp

2019 ◽  
pp. 70-80
Author(s):  
Hanaa H. Abd El Baky ◽  
Gamal S. El Baroty
Keyword(s):  
Hydrogen Production ◽  
Value Added ◽  
Gas Production ◽  
Hydrogen Gas ◽  
Logarithmic Phase ◽  
Dark Condition ◽  
Sulfur Deprivation ◽  
Total Carbohydrate ◽  
Chlamydomonas Sp ◽  
In Cells

Hydrogen gas could provide attractive options as ideal fuel for a world, in which environmental friendly and economically sustainable manner. Microalgae have the ability to bio-synthesis hydrogen gas. Algal H2 does do not generate any toxic or polluting bi-products and could potentially offer value-added products derived from algal biomass. In this work, the feasibility of coupling sulfur deprivation and light on hydrogen production by Chlamydomonas sp grown in photobioreactor was investigated. The cells growth, hydrogen production, total carbohydrate and chlorophyll content were determined. The results showed that, under optimum condition, algae cells were required 168 hr (7days) to reach the late logarithmic phase (the algal dry weight 4.11 g/L). Whereas the algae cells were needed about 18~22 days to reach this value (3.55 g/ L) when grow in optimum medium. The concentration of Chlorophyll (5.65%) and carbohydrate (39.46%) were accumulated in algae cells grow in S-deprives medium coupled with dark condition over that did in algae cells cultured in optimum medium. After about a 24 h of cultivation, photo-production of H2 was observed for C. sp either in absence or presence of sulfate. But under sulfur deprivation coupled with dark condition, higher H2 gas was obtained after 16 hr (7 several days) of incubation period. In new design photobioreactors (PhBRs), after 18 days of cultivation, the volume of H2 gas in was found to be 450 ml in cells grow in sulfur-deprived culture). This value was 360 ml in cells grow under optimal condition.

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