Preben Graae Sørensen

Postal address
Department of Chemistry
University of Copenhagen
H.C. Ørsted Institute
Universitetsparken 5
DK - 2100, Copenhagen Ø


Phone: (45) 35 32 02 46
Fax:      (45) 35 32 02 59


Dynamics of Chemial Systems

Use of amplitude equations for modelling of spatiotemporal phenomena in complex chemical systems.
M. Ipsen, F. Hynne and P.G. Sørensen ``Systematic derivation of amplitude equations and normal forms for dynamical systems'' Chaos 8 (1998) 834-852.

M. Ipsen, F. Hynne and P. G. Sørensen ``Amplitude equations for reaction-diffusion systems with a Hopf bifurcation and slow real modes'' Physica D 136 (2000) 66-92

M. Ipsen and P.G. Sørensen ``Finite wavelength instabilities in a slow mode coupled complex Ginzburg-Landau equation''
Phys. Rev. Lett. 84 (2000)2389-2392    [Link to abstract or download]

M.Ipsen; L.Kramer, and P.G.Sørensen ``Amplitude equations for description of chemical reaction-diffusion systems''
Phys.Rep.-Rev.Sect.Phys.Lett. 337 (2000) 193-235   

H.Skødt and P.G.Sørensen ''Antispirals in an Artificial Tissue of Oscillatory cells'' Phys.Rev.E 68 020902-1 (2003)

Kinetic spectrometry
The linear behavior of a chemical system close to a stationary state can be investigated in a very efficient way by experimental perturbations with different chemical substances. For oscillatory systems close to a Hopf bifurcation a range of different chemical systems have been studied by a method we have called quenching analysis and we have obtained detailled information on the chemical mechanism. By use of control theory the quenching method has been generalized to a method for efficient experimental determination of all the elements of the Jacobian matrix at the bifurcation point.

E. Mihaliuk, H. Skødt, F. Hynne, P.G. Sørensen, K. Showalter ``Normal modes for chemical reactions from time series analysis'' J. Phys. Chem. 103 (1999) 8246-8251

Experimental studies of wave phenomena.
F.G.Jensen; J.Sporring; M.Nielsen and P.G.Sørensen ''Tracking target and spiral waves'' Chaos 12 (2002) 16-26

Studies of the coupling between chemical reactions and hydrodynamic convection.

A.J. Pons, F. Sagués, M.A. Bees, and P.G.Sørensen ``Pattern Formation in the Methylene-Blue-Glucose System'' J. Phys. Chem 104 (2000) 2251-2259

M.A.Bees; A.J. Pons; P. G. Sørensen; F. Sagués ``Chemoconvection a chemically driven hydrodynamic instability'' J. Chem. Phys. 114 (2001) 1932-1943

A.J.Pons, F.Sagués, M.A.Bees and P.G.Sørensen ''Quantitative analysis of chemoconvection patterns in the Methylene-Blue-Glucose system.'' J.Phys.Chem.B. 106 (2002) 7252-7259

Dynamics of Biological Systems

Oscillations and chaos in yeast extract
K. Nielsen, P.G. Sørensen, F. Hynne and H.G. Busse ``Sustained oscillations in Glycolysis: An experimental and theoretical study of chaotic and complex periodic behavior and of quenching of simple oscillations'' Biophysical Chemistry 72 (1998) 49-62    [MEDLINE]

Oscillations in living yeast cells.
Glycolytic oscillations in stirred suspensions of living yeast cells have been known for a long time. The root of this macroscopically observable phenomenon is that glycolytic oscillations in the individual cell are syncronized by some unknown mechanism of intercellular communication.
S. Danø, P.G. Sørensen og F. Hynne `` Sustained oscillations in living cells''
Nature 102 (1999) 320-322      [MEDLINE]

F.Hynne. S.Danø and P.G.Sørensen ''A Functional Dynamics Approach to Modelling of Glycolysis'' in Function and Regulation of Cellular Systems: Experiments and Models ed. by A.Deutsch Birkhauser Verlag Basel/Switzerland 2003.

M.Madsen, S.Danø and P.G.Sørensen ''On the mechanism of glycolytic oscillations in Saccharomyces cerevisiae'' FEBS J. in press

S.Danø, M-Madsen and P.G.Sørensen ''Chemical interpretation of oscillatory modes at a Hopf point'' PCCP in press

Modelling a population of oscillatory yeast cells
The system has been modelled as a set of Stuart-Landau oscillators communicating with each other through the medium. The Stuart-landau parameters of the cells are estimated from the experimental measurements. Depending on the actual values of the parameters the system shows a remarkable variety in the syncronization dynamics from attration to a stable stationary state through syncroneous oscillations of the system to partial syncronization which can be observed experimentally as periodic or chaotic oscillations of the order parameter.

S. Danø, F. Hynne and P. G. Sørensen ``Dynamics of Yeast Cell Populations'' Physical Chemistry 2000, Proceedings of the 5th International Conference on Fundamental and Applied Aspects of Physical Chemistry, Belgrade, Yugoslavia (2000) 12-19 [gzip'ed PostScript] [PDF]

F.Hynne; S.Danø; P.G.Sørensen ''Full-scale model of glycolysis in Saccharomyces cerevisiae'' Biophys.Chem. 94 (2001) 121-163

S.Danø; F.Hynne; S.DeMonte; F,d'Ovidio; P.G.Sørensen and H.Westerhoff ''Synchronization of glycolytic oscillations in a yeast cell population.'' Faraday Disc. 2001 120 295-312


Experimental course in Physical Chemistry [KemiF1x]


Center for Chaos and Turbulence Studies (CATS)
overview and research.

European Center of Excellence
Biosimulation - A new tool for drug development