Beskrivning: Photo of SDStefan Diehl 

Associate Professor in Applied Mathematics (Docent i tillämpad matematik)

Centre for Mathematical Sciences
Lund University/Lund Institute of Technology
P.O. Box 118
SE-221 00 Lund
SWEDEN

Room: 551A
Direct phone: +46 46 222 0920
Dept phone: +46 46 222 8537
Fax: +46 46 222 4010
E-mail:
stefan.diehl@math.lth.se


Miscellaneous (in Swedish/English)

Introduction to the scalar nonlinear conservation law

Min docentföreläsning om modellering av trafikflöde, september 2006

Jag har skrivit en bok Inledande geometri för högskolestudier (innehåll) som ges ut av Studentlitteratur.

Proposals of thesis projects for Master of Science degree

Modelling and simulation of flotation
Simulation of a wastewater treatment plant with positivity-preserving numerical methods

Modelling, simulation and flux identification of traffic flow

Optimization of pedestrian evacuation modelled by PDE


Research

Interests

Supervision of PhD students

Theses

S. Diehl: Shock behaviour of sedimentation in wastewater treatment, Lund University, 1988:13/ISSN 0327-8475 (1988) (Master's thesis)

S. Diehl: Scalar conservation laws with source term and discontinuous flux function, Lund University, 1992:8/ISSN 0327-8475 (1992) (Licentiate's thesis)

S. Diehl: Conservation Laws with Application to Continuous Sedimentation, Lund University, ISBN 91-628-1632-2 (1995) (PhD thesis)

Journal publications

If you are interested in a publication that you cannot find in the links below, please send me an email.

  1. S. Diehl: On scalar conservation laws with point source and discontinuous flux function. SIAM J. Math. Anal., 26(6), 1425–1451, 1995. Submitted version.
  2. S. Diehl: Scalar conservation laws with discontinuous flux function: I. The viscous profile condition. Comm. Math. Phys., 176, 23–44, 1996. Submitted version.
  3. S. Diehl, Nils-Olof Wallin: Scalar conservation laws with discontinuous flux function: II. On the stability of the viscous profiles. Comm. Math. Phys., 176, 45–71, 1996.
  4. S. Diehl: A conservation law with point source and discontinuous flux function modelling continuous sedimentation. SIAM J. Appl. Math., 56(2), 388419, 1996.
  5. U. Jeppsson and S. Diehl: An evaluation of a dynamic model of the secondary clarifier. Water Sci. Tech., 34(5–6), 19–26, 1996.
  6. U. Jeppsson and S. Diehl: On the modelling of the dynamic propagation of biological components in the secondary clarifier. Water Sci. Tech., 34(5–6), 85–92, 1996.
  7. S. Diehl: Dynamic and steady-state behaviour of continuous sedimentation. SIAM J. Appl. Math., 57(4), 991–1018, 1997.
  8. S. Diehl: Continuous sedimentation of multi-component particles. Math. Meth. Appl. Sci., 20, 1345–1364, 1997.
  9. S. Diehl and U. Jeppsson: A model of the settler coupled to the biological reactor. Water Res., 32(2), 331–342, 1998.
  10. S. Diehl: On boundary conditions and solutions for ideal clarifier-thickener units. Chem. Eng. J., 80, 119–133, 2000. (A conference talk in 1999.)
  11. S. Diehl: Operating charts for continuous sedimentation I: Control of steady states. J. Eng. Math., 41, 117–144, 2001. (Final draft)
  12. S. Diehl: Operating charts for continuous sedimentation II: Step responses. J. Eng. Math., 53, 139185, 2005. (Final draft)
  13. S. Diehl: Operating charts for continuous sedimentation III: Control of step inputs. J. Eng. Math., 54, 225259, 2006. (Final draft)
  14. S. Diehl: Estimation of the batch-settling flux function for an ideal suspension from only two experiments. Chem. Eng. Sci., 62, 45894601, 2007. http://dx.doi.org/10.1016/j.ces.2007.05.025
  15. S. Diehl: Operating charts for continuous sedimentation IV: Limitations for control of dynamic behaviour. J. Eng. Math., 60, 249264, 2008. (Final draft)
  16. S. Diehl: A regulator for continuous sedimentation in ideal clarifier-thickener units. J. Eng. Math. 60, 265291, 2008. (Final draft)
  17. S. Diehl: The solids-flux theory – confirmation and extension by using partial differential equations. Water Res. 42, 49764988, 2008. http://dx.doi.org/10.1016/j.watres.2008.09.005
  18. S. Diehl: A uniqueness condition for nonlinear convection-diffusion equations with discontinuous coefficients. J. Hyperbolic Differential Equations, 6, 127159, 2009. (submitted version)
  19. R. Bürger, S. Diehl and I. Nopens:  A consistent modelling methodology for secondary settling tanks in wastewater treatment. Water Res. 45, 22472260, 2011. http://dx.doi.org/10.1016/j.watres.2011.01.020
  20. E. Torfs, R. Bürger, S. Diehl, S. Farås and I. Nopens: A reliable numerical method for secondary settling modelling. Comm. Appl. Biol. Sci. 77(1), 151–156, 2012.
  21. R. Bürger, S. Diehl, S. Farås and I. Nopens: On reliable and unreliable numerical methods for the simulation of secondary settling tanks in wastewater treatment. Computers Chem. Eng. 41, 93105, 2012.
  22. S. Diehl and S. Farås: Fundamental nonlinearities of the reactor-settler interaction in the activated sludge process. Water Sci. Tech. 66(1), 28–35, 2012.
  23. S. Diehl and S. Farås: A reduced-order ODE-PDE model for the activated sludge process in wastewater treatment: Classification and stability of steady states. Math. Models Meth. Appl. Sci., 23(3), 369–405, 2013.
  24. S. Diehl and S. Farås: Control of  an ideal activated sludge process in wastewater treatment via an ODE-PDE model. J. Process Control. 23, 359–381, 2013. (submitted version)
  25. R. Bürger and S. Diehl: Convexity-preserving flux identification for scalar conservation laws modelling sedimentation. Inverse Problems. 29(4), 045008, 2013.
  26. R. Bürger, S. Diehl, S. Farås, I. Nopens and E. Torfs: A consistent modelling methodology for secondary settling tanks: A reliable numerical method. Water Sci. Tech., 68(1), 192–208, 2013.
  27. F. Betancourt, R. Bürger, S. Diehl and S. Farås: Modelling and controlling clarifier-thickeners fed by suspensions with time-dependent properties. Minerals Eng., 62,  91–101, 2014.
  28. F. Betancourt, R. Bürger, S. Diehl and C. Mejías: Advanced methods of flux identification for clarifier-thickener simulation models. Minerals Eng., 63, 2–15, 2014.
  29. S. Diehl, E. Henningsson, A. Heyden and S. Perna: A one-dimensional moving-boundary model for tubulin-driven axonal growth. J. Theor. Biol., 358, 194–207, 2014.
  30. S. Diehl: Numerical identification of constitutive functions in scalar nonlinear convection-diffusion equations with application to batch sedimentation. Appl. Num. Math., 95, 154–172, 2015.
  31. E. Torfs, T. Maere, R. Bürger, S. Diehl and I. Nopens: Impact on sludge inventory and control strategies using the benchmark simulation model no. 1 with the Bürger-Diehl settler model. Water Sci. Tech., 71(10), 1524–1535, 2015.
  32. J. Zambrano, B. Carlsson and S. Diehl: Optimal steady-state design of zone volumes of bioreactors with Monod growth kinetics. Biochem. Eng. J., 100, 59–66, 2015.
  33. S. Diehl , S. Farås and G. Mauritsson: Fast reliable simulations of secondary settling tanks in wastewater treatment with semi-implicit time discretization, Computers Math. Appl., 70(4), 459–477, 2015. 
  34. S. Diehl and J. Zambrano and B. Carlsson: Steady-state analysis of activated sludge processes with a settler model including sludge compression. Water Res. 88C, 104116, 2016.
  35. R. Bürger, S. Diehl and C. Mejías: On time discretizations for the simulation of the batch settling-compression process in one dimension. Water Sci. Tech. 73(5), 10101017, 2016.
  36. S. Diehl, E. Henningsson and A. Heyden: Efficient simulations of tubulin-driven axonal growth. J. Comp. Neurosci. 119, 2016.
  37. R. Bürger, J. Careaga, S. Diehl, C. Mejías, I. Nopens, E. Torfs and P. A.Vanrolleghem: Simulations of reactive settling of activated sludge with reduced biokinetic model. Computers Chem. Eng. 92, 216–229, 2016.
  38. S. Diehl, J. Zambrano and B. Carlsson: Steady-state analyses of activated sludge processes with plug-flow reactor. J. Env. Chem. Eng. 5(1), 795–809, 2017.  
  39. E. Torfs,  F. Locatelli, S. Balemans, J. Laurent, P. A.Vanrolleghem, R. Bürger, S. Diehl, P. François and I. Nopens: Concentration-driven models revisited: Towards a unified framework to model settling tanks in WRRFs. Water Sci. Tech. 75(3), 539–551, 2017.
  40. E. Torfs, S. Balemans, F. Locatelli, S. Diehl, R. Bürger, J. Laurent, P. François and I. Nopens: On constitutive functions for hindered settling velocity in 1-D settler models: selection of appropriate model structure. Water Res. 110, 38–47, 2017.
  41. R. Bürger, J. Careaga and S. Diehl: Entropy solutions of a scalar conservation law modelling sedimentation in vessels with varying cross-sectional area. SIAM J. Appl. Math. 77(2), 789–811, 2017.
  42. R. Bürger, S. Diehl, M. C. Martí, P. Mulet; I. Nopens, E. Torfs, P. A. Vanrolleghem: Numerical solution of a multi-class model for batch settling in water resource recovery facilities. Appl. Math. Modelling 49, 415436, 2017.
  43. F. Betancourt, R. Bürger, C. Chalons, S. Diehl and S. Farås: A random sampling method for a family of Temple-class systems of conservation laws. To appear in Numerische Mathematik.
  44. R. Bürger, J. Careaga and S. Diehl: A simulation model for settling tanks with varying cross-sectional area. To appear in Chem. Eng. Commun.
  45. R. Bürger, S. Diehl and C. Mejías: A difference scheme for a degenerating convection-diffusion-reaction system modelling continuous sedimentation. To appear in ESAIM: Math. Modelling Num. Anal.

Conference publications

  1. S. Diehl, G. Sparr and G. Olsson: Analytical and numerical description of the settling process in the activated sludge operation. In R. Briggs, editor, Instrumentation, Control and Automation of Water and Wastewater Treatment and Transport Systems, pages 471-478. IAWPRC, Pergamon Press, 1990.
  2. U. Jeppsson and S. Diehl: Validation of a robust model of continuous sedimentation. Proc. 9th Forum for Applied Biotechnology (FAB), Med. Fac. Landbouww. Univ. Gent, 60/4b, 1995, pp 2403-2414.
  3. R. Bürger, S. Diehl, S. Farås and I. Nopens: Simulations of the secondary settling process with consistent numerical methods.WATERMATEX 2011: 8th IWA Symposium on Systems Analysis and Integrated Assessment, San Sebastian, Spain, 2011.
  4. S. Diehl and S. Farås: Fundamental nonlinearities of the reactor-settler interaction in the activated sludge process. WATERMATEX 2011: 8th IWA Symposium on Systems Analysis and Integrated Assessment, San Sebastian, Spain, 2011.
  5. S. Diehl. Shock-wave behaviour of sedimentation in wastewater treatment: a rich problem. Analysis for Science, Engineering and Beyond. The Tribute Workshop in Honour of Gunnar Sparr held in Lund, May 8-9, 2008. Åström, K.; Persson, L.-E.; Silvestrov, S. D. (Eds.). Springer Proceedings in Mathematics, Springer Berlin Heidelberg.Vol. 6, 175–214, 2012.
  6. S. Gedda, C. Andersson, J. Åkesson and S. Diehl: Derivative-free Parameter Optimization of Functional Mock-up Units. Proceedings of the 9th International MODELICA Conference, September 3-5, 2012, Munich, Germany.
  7. E. Torfs, T. Maere, R. Bürger, S. Diehl, S. Farås and I. Nopens: Towards improved 1-D settler modelling: impact on control strategies using the Benchmark Simulation Model. In: Proceedings of Instrumentation Control and Automation, 11th IWA conference, International Water Association (IWA), Narbonne, France, Sep 18-20, 2013.
  8. E. Torfs, P. Vlasschaert, Y. Amerlinck, R. Bürger, S. Diehl, S. Farås and I. Nopens: Towards improved 1-D settler modelling: calibration of the Bürger model and case study. Proceedings of 86th Annual Water Environment Federation Technical Exhibition and Conference (WEFTEC), Mc Cormick Place South, Chicago, IL, USA, 5-9 October 2013.
  9. E. Torfs,  F. Locatelli, S. Balemans, J. Laurent, P. A.Vanrolleghem, R. Bürger, S. Diehl, P. François, R. Mosse and I. Nopens: Concentration-driven models revisited: Towards a unified framework to model settling tanks in WWTPs. Proceedings 5th IWA/WEF Wastewater Treatment Modelling Seminar (WWTmod2016). Annecy, France, April 2-6, 2016. 109-118. 2016.
  10. J. Zambrano, B. Carlsson, S. Diehl and E. Nehrenheim: A simplified model of an activated sludge process with a plug-flow reactor. Proceedings of The 9th Eurosim Congress on Modelling and Simulation, Oulu Finland, 12-16 September 2016.
  11. R. Bürger, S. Diehl and C. Mejías: A Model for Continuous Sedimentation with Reactions for Wastewater Treatment. Lecture Notes in Civil Engineering 4. G. Mannina (ed.). Springer International Publishing. 596-601. 2017.

Submitted manuscripts


  1. R. Bürger, J. Careaga and S. Diehl: Flux identification of scalar conservation laws from sedimentation in a cone.
  2. S. Diehl, J. Zambrano and B. Carlsson: Analysis of photobioreactors in series.
  3. R. Bürger, S. Diehl and M. C. Martí: A conservation law with multiply discontinuous flux modelling a flotation column.
  4. R. Bürger, J. Careaga, S. Diehl, R. Merckel and J. Zambrano: Estimating the hindered-settling flux function from a batch test in a cone.