Prediction Of Flux Distribution Research Articles

Metabolic model of Synechococcus sp. PCC 7002: Prediction of flux distribution and network modification for enhanced biofuel production

Flux Balance Analysis was performed with the Genome Scale Metabolic Model of a fast growing cyanobacterium Synechococcus sp. PCC 7002 to gain insights that would help in engineering the organism as a production host. Gene essentiality and synthetic lethality analysis revealed a reduced metabolic robustness under genetic perturbation compared to the heterotrophic bacteria Escherichia coli. Under glycerol heterotrophy the reducing equivalents were generated from tricarboxylic acid cycle rather than the oxidative pentose phosphate pathway. During mixotrophic growth in glycerol the photosynthetic electron transport chain was predominantly used for ATP synthesis with a photosystem I/photosystem II flux ratio higher than that observed under autotrophy. An exhaustive analysis of all possible double reaction knock outs was performed to reroute fixed carbon towards ethanol and butanol production. It was predicted that only ∼10% of fixed carbon could be diverted for ethanol and butanol production.

Prediction of flux distribution of mutants by enzyme control fluxes with maximum entropy principal

Prediction of flux distribution of mutants by enzyme control fluxes with maximum entropy principal

Effect of Polydispersity of Droplets in the Prediction of Flux Distribution in a Venturi Scrubber

The effect of polydispersity of droplets on the liquid flux distribution in a Venturi scrubber is investigated using a 2-D model along the length of a Venturi scrubber. Two average drop-sizes (the Sauter mean diameter and the mass median diameter) and two drop-size distribution functions (the upper-limit distribution function and the universal root-normal distribution function) are used in the model to predict liquid flux distribution. It is found that the flux distribution is a strong function of the polydispersity of droplets. It is also found that the throat gas velocity has a greater effect on the polydispersity of droplets than L/G ratio. At low throat gas velocity, flux distributions, predicted by the model using drop-size distributions, match with experimental data for a wide range of L/G ratios. At high throat gas velocities, flux distributions, predicted using average drop-sizes, follow experimental results closely. An analysis of overall collection efficiency reveals that it is nearly independent of polydispersity of droplets at low liquid-to-gas ratios and high gas velocities.

Prediction of flux distribution as a means to nondestructive testing of oil-pipe materials (abstract)

The flux distribution for a given excitation is determined in the cross section of an oil pipe, in its interior and exterior regions, in order to utilize this information eventually for the nondestructive testing of the material of the pipe. A two-dimensional mathematical model is established under certain simplifying assumptions and the grid system is laid out for numerical analysis. The relevant partial differential equations of the magnetic vector potential as well as their difference algorithms are developed. An innovative combination of rectangular and polar grid systems is used to follow the contours of the cross section consisting of the oil pipe and the excitation mechanism made up of a core, coil, and two steel brushes. The reluctivity of ferromagnetic materials is assumed to be a function of the magnetic induction. An iterative procedure consisting of successive-point relaxation of vector potentials with an optimum over-relaxation factor, a block-relaxation method for accelerating the convergence, relaxation of reluctivities with an optimum under-relaxation factor, and a constant monitoring of the convergence of the sum of absolute values of residuals as well as of the absolute value of the maximum residual is described. Computer programs in fortran language are developed and applied to find the flux distribution inside and outside the cross section of the oil pipe for various excitation-current densities. Analytical results are compared with experimental data. Refined analyses including eddy-current and three-dimensional effects are under way.