User:Siegfried Hess/sandbox

Siegfried Hess
Siegfried Hess (born 1940 in Hof/Saale, Northern Bavaria, Germany) is a retired Professor of Theoretical Physics at the Technical University (TU) Berlin. His scientific work is devoted to Statistical Physics of material properties and non-equilibrium phenomena in condensed matter, e.g. in gases, liquids, liquid crystals, colloidal dispersions, ferro-fluids, polymeric liquids, and also to elastic properties and plastic flow of solids. The research ranges from the basics of the theory and the derivation of the relevant equations to their solutions with analytical and numerical calculations, as well as the comparison with results from computer simulations and from experiments or suggestions for new experiments. In addition to about 250 articles in journals and contributions to books, he published an introduction to Mechanics and Quantum Mechanics [1] for "children" from eight to eighty and a compendium on Tensors for Physics [2]. Scientific collaborations led to publications with about 100 coauthors from 20 countries of all continents. He is a member of the Accademia Peloritana dei Pericolanti at Messina, Sicily, Italy.

Education and Career
Siegfried Hess studied Mathematics and Physics at the University Erlangen, where he got a Physics diploma degree in 1964. He was a graduate student in Chemical Engineering at the University of Minnesota in Minneapolis, USA. In 1967 he was promoted to PhD in Erlangen with a thesis on the foundation of the Kinetic Theory for Polyatomic Gases, supervised by Ludwig Waldmann. S. Hess was post doc at the Kamerlingh Onnes Laboratory of the University of Leiden, Holland, he became Professor for Theoretical Physics in Erlangen and, in 1984, at the TU Berlin. He worked as guest scientist and visiting professor at the Physics Department of the University of Toronto, Canada, at the Huygens Laboratory (University of Leiden, Holland), at the National Bureau of Standards in Boulder (Colorado, USA), at the Institute Laue-Langevin, (Grenoble, France), at the Research School of Chemistry of the Australian National University in Canberra and at the Kavli Institute for Theoretical Physics of the University of California, Santa Barbara, USA.

Properties and Phenomena studied:
Transport and relaxation processes, viz. heat conduction, viscous flow and Rheology, diffusion; Influence of external magnetic and electric fields on transport properties; Effects of boundary conditions; Anisotropy of the transport coefficients; Non-equilibrium alignment phenomena, e.g. flow and heat flow birefringence; Spin relaxation and spin-diffusion, line broadening; Phase transitions; Elastic properties and plastic behavior, dry friction; Interplay between macroscopic properties and microscopic structure, shear-flow induced structal changes.

Methods used:
Kinetic Theory [3, 6], mesoscpic Fokker-Planck equation [4] approach, Irreversible Thermodynamics [10], modeling experimental observations by the derivation and solution of ordinary and partial differential equation with analytical and numerical methods [8, 10, 14-16], microscopic computer simulations (MD, NEMD, MC) [5-7, 9, 11-13] suggestions for new experiments [3, 14, 15].

Applications to:
Monatomic and polyatomic gases [3, 6], simple and molecular liquids [7], liquid crystals [4, 5, 8, 10, 13], colloidal dispersions [14-16], ferro-fluids and magneto-rheological fluids [11], polymeric liquids [9], solids [12].

Books:

 * 1. Siegfried Hess, "Opa, was macht ein Physiker?", Wiley-VCH, Weinheim 2014, ISBN 978-3-527-41263-1.
 * 2. Siegfried Hess, "Tensors for Physics", Springer International 2015, ISBN 978-3-319-12786-6.

Pioneering and seminal articles in journals:

 * 3. S. Hess, "Flow birefringence of polyatomic gases", Phys. Letters 30A, 239 (1969).
 * 4. S. Hess, Fokker-Planck-Equation approach to flow aligment in liquid crystals, Z. Naturforsch. 31a, 1034 (1976)
 * 5. D. Baalss and S. Hess, "Nonequilibrium molecular dynamics studies on the anisotropic viscosity of perfectly aligned nematic liquid crystals", Phys. Rev. Lett. 57, 86 (1986);
 * 6. W. Loose and S. Hess, "Velocity distribution function of a streaming gas via nonequilibrium molecular dynamics", Phys. Rev. Lett. 58, 2443 (1987);
 * 7. O. Hess, W. Loose, T. Weider and S. Hess, "Shear-induced anisotropy of the structure of dense fluids", Physica B156/157, 505 (1989).
 * 8. A. Sonnet, A. Kilian and S. Hess, "Alignment tensor versus director: description of defects in nematic liquid crystals", Phys. Rev. E 52, 718 (1995);
 * 9. M. Kröger and S. Hess, "Rheological evidence for a dynamical crossover in polymer melts via nonequilibrium molecular dynamics", Phys. Rev. Lett. 85 (2000) 1128-1131.
 * 10. G. Rienäcker, M. Kröger, and S. Hess, "Chaotic orientational behavior of a nematic liquid crystal subjected to a shear flow", Phys. Rev. E 66 (2002) 040702 (4 pages).
 * 11. P. Ilg, M. Kröger, and S. Hess, "Magnetoviscosity and orientational order parameters of dilute ferrofluids", J. Chem. Phys. 116 (2002) 9078.
 * 12. I. Stankovic, S. Hess and M. Kröger, "Microscopic structure, dynamics, and wear at metal-metal interfaces in sliding contact", Phys. Rev. E 70 (2004) 066139 (14 pages)
 * 13. H. Steuer and S. Hess, "Direct computation of the twist elastic coefficient of a nematic liquid crystal via Monte Carlo simulation", Phys. Rev. Lett. 94 (2005) 027802 (4 pages)
 * 14. M .G. Forest, S. Heidenreich, S. Hess, X. Yang and R. Zhou, "Robustness of pulsating jet-like layers in sheared nano-rod dispersions", .J. Non-Newtonian Fluid Mech. 155 (2008) 130-145.
 * 15. S. Heidenreich, S. Hess and S. H. L. Klapp, "Shear-induced dynamic polarization and mesoscopic structure in suspensions of polar nanorods", Phys. Rev. Lett. 102 (2009) 028301.
 * 16. C. Goddard, O. Hess, and S. Hess, "Low Reynolds number turbulence in nonlinear Maxwell-model fluids", Phys. Rev. E 81, 036310 (2010).