University of Leicester

Department of Engineering

Department of Engineering
Prof Len A. Dissado

Professor of Engineering
University of Leicester, Leicester, LE1 7RH
Tel: (+44)/(0) 116 252 2577
e-mail: lad4@le.ac.uk

Professor Dissado studied at University College, London University between 1960 and 1966, obtaining a B.Sc. 1st Class in Chemistry in 1963 and a Ph.D. in Theoretical Chemistry in 1966. He spent two periods as a Research Fellow at the Australian National University in Canberra (1967-1970 and 1973-1977) where he worked on the theory of exiton-phonon interactions in aromatic chemistry. In between he spent 3 years at the UK Atomic Energy Authority. From 1977 to 1995 he has worked on the theory of dielectric relaxation, electrical degradation and breakdown statistics, first in the Department of Physics at Chelsea College, and after amalgamation at the Department of Physics, King's College, London. He took up an appointment as Reader in Engineering at The University of Leicester in 1995, and was appointed to a personal chair in 1998.

Since 1981 Professor Dissado has been a scientific consultant at STL (Standard Telecommunications Laboratory) Harlow, Essex, UK) now Alcatel Submarine Networks at Greenwich, London. He has published 230 papers on a range of topics relating to excimer formation of crystals, the theory of dielectric relaxation, the impedance spectroscopy of biotissues, pre- breakdown degradation, and breakdown statistics. He has published one book on Electrical Breakdown and Degradation in Polymers, and a chapter on the theory of Dielectric Relaxation in Advances in Chemical Physics. In 1990 he was awarded the degree of Doctor of Science (D.Sc.) by the University of London.

Since 1995 Professor Dissado has spent time as a Visiting Professor or Researcher at, Universite Pierre et Marie Curie (Paris, France), Universite Paul Sabatier (Toulouse, France), Nagoya University Nagoya, Japan), and National Institute of Standards and Technology (Boulder, USA). He has given many invited lectures, and has twice been invited to give the keynote address to the symposium of Electrical and Electronic Insulating Materials and Applications in Systems run by IEE Japan. In June 2001 Professor Dissado delivered the E.O.Forster Memorial Lecture’ at the IEEE conference ICSD at Eindhoven in The Netherlands. He also gave the ‘Whitehead Memorial Lecture’ at the IEEE conference CEIDP in Cancun, Mexico in October 2002. He was elected a fellow of IEEE effective Jan.2006. In 2006 he was also one of four recipients to have the honorary degree ‘Docteur Honoris Causa’ conferred upon him by the Universite Paul Sabatier in Toulouse, France.
Current research interests centre on two major topics: 1) The development of a quantitative physical model for the initiation and propagation of electrical tree degradation in Polymers; and (2) The investigation of space charge effects in insulating materials and in particular their relationship to electrical ageing. A minor interest is the use of impedance spectroscopy to characterise materials of all kinds.
L.A.Dissado BSc, PhD, DSc, FIEEE


Principal Publications, Prof. L. A. Dissado, 2001 – 2005

Space charge behaviour in epoxy laminates under high constant electric field
Hole, Stephane (Laboratoire des Instruments et Systemes d'Ile de France, Universite Pierre et Marie Curie); Dissado, Leonard A.; Ajour, Mohammed N.; Fothergill, John C. Source: Journal of Physics D: Applied Physics, v 38, n 16, Aug 21, 2005, p 2890-2898

Numerical resolution of charge transport in cross-linked polyethylene by means of a bipolar model with a distribution of traps
Boufayed, F. (Inst. de Genie Electr., Electron. et Plasmas, Univ. Paul Sabatier, Toulouse, France); Leroy, G.; Teyssedre, G.; Laurent, C.; Segur, P.; Cooper, E.; Dissado, L.A.; Montanari, G.C. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics (IEEE Cat. No.04CH37539), 2004, pt. 2, p 562-6 Vol.2

Model for electrical tree initiation in epoxy resin
Wu, Kai (Central Research Institute of Electric Power Industry); Dissado, L.A. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 12, n 4, August, 2005, p 655-668

Are partial discharges in artificial tubes chaotic?
Dissado, L.A. (Department of Engineering, The University of Leicester); Suzuoki, Y.; Kaneiwa, H. Source: Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials, v 3, 2003, p 871-874

Demonstrating a threshold for trapped space charge accumulation in solid dielectrics under dc field
Dissado, L.A. (University of Leicester); Laurent, C.; Montanari, G.C.; Morshuis, P.H.F. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 12, n 3, June, 2005, p 612-620

Numerical resolution of charge transport in cross-linked polyethylene by means of a bipolar model with a distribution of traps
Boufayed, F. (Inst. Genie Elec., Electron./Plasmas, Universite Paul Sabatier); Leroy, S.; Teyssedre, G.; Laurent, C.; Segur, P.; Cooper, E.; Dissado, L.A.; Montanari, G.G. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, v 2, Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, 2004, p 562-566

Percolation model for electrical breakdown in insulating polymers
Wu, K. (Department of Engineering, University of Leicester); Dissado, L.A. Source: Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP, 2004 Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP, 2004, p 514-518

Effect of temperature on space charge formation in low density polyethylene - role of antioxidant
Boudou, L. (Lab. de Genie Electr., UMR-CNRS, Toulouse, France); Griseri, V.; Guastavino, J.; Dissado, L.A. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics (IEEE Cat. No.04CH37539), 2004, pt. 1, p 252-5 Vol.1

Electrical, microstructural, physical and chemical characterization of HV XLPE cable peelings for an electrical aging diagnostic data base
Fothergill, John C. (Department of Engineering, University of Leicester); Montanari, Gian Carlo; Stevens, Gary C.; Laurent, Christian; Teyssedre, Gilbert; Dissado, Leonard A.; Platbrood, Gerard; Nilsson, U.H. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 10, n 3, June, 2003, p 514-527

Effect of temperature on space charge formation in low density polyethylene - Role of antioxidant
Boudou, L. (Lab. de Genie Electrique); Griseri, V.; Guastavino, J.; Dissado, L.A. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, v 1, Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, 2004, p 252-255

Model for electroluminescence in polymers during the early stage of electrical tree initiation
Wu, K. (Dept. of Eng., Leicester Univ., UK); Dissado, L.A. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics (IEEE Cat. No.04CH37539), 2004, pt. 2, p 505-8 Vol.2

Comparative study of space charge in the polymeric insulation of power cables using PEA, isothermal and non-isothermal currents measurements
Lanca, M.C. (Departamento de Ciencia dos Materiais, Universidade Nova de Lisboa, Caparica, Portugal); Fu, M.; Neagu, E.; Dissado, L.A.; Marat-Mendes, J.; Tzimas, A.; Zadeh, S. Source: 12th International Symposium on Electrets (IEEE Cat. No.05CH3769), 2005, p 284-7

Anomalous dielectric response of very small quantities of virgin, aged and failed silicone oil
Haidar, A. (Department of Engineering, University of Leicester); Fothergill, J.C.; Dissado, L.A.; Hopewell, P. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 10, n 2, April, 2003, p 336-342

Percolation model for electrical breakdown in insulating polymers
Wu, K. (Dept. of Eng., Leicester Univ., UK); Dissado, L.A. Source: 2004 Annual Report conference on Electrical Insulation and Dielectric Phenomena (IEEE Cat. No.04CH37584), 2004, p 514-18

Molecular Dynamics simulation of the hollandite Nax(Ti 8-xCrx)O16: Ion transport and high frequency dielectric absorption
Khoo, K.L. (Engineering Department, University of Leicester); Dissado, L.A.; Fothergill, J.C.; Hussain, S.; Youngs, I. Source: Proceedings of the International Symposium on Electrical Insulating Materials, v 1, Proceedings of 2005 International Symposium on Electrical Insulating Materials, ISEIM 2005, 2005, p 21-24

"Sub-hertz" dielectric spectroscopy

Fothergill, J.C. (Department of Engineering, University of Leicester); See, K.B.A.; Ajour, M.N.; Dissado, L.A. Source: Proceedings of the International Symposium on Electrical Insulating Materials, v 3, Proceedings of 2005 International Symposium on Electrical Insulating Materials, ISEIM 2005, 2005, p 821-824

Simulation of bipolar charge transport in polyethylene featuring trapping and hopping conduction through an exponential distribution of traps
Boufayed, F. (Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier); Leroy, S.; Teyssedre, G.; Laurent, C.; Segur, P.; Dissado, L.A.; Montanari, G.C. Source: Proceedings of the International Symposium on Electrical Insulating Materials, v 2, Proceedings of 2005 International Symposium on Electrical Insulating Materials, ISEIM 2005, 2005, p 340-343

Model for electroluminescence in polymers during the early stage of electrical tree initiation
Wu, K. (Department of Engineering, University of Leicester); Dissado, L.A. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, v 2, Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, 2004, p 505-508

Comparison of constitutive wheat bran tissues by dielectric spectroscopy and effect of their moisture content
Antoine, Carole (UMR, Agropolymers Eng./Emerging Technolog, INRA); Castellon, Jerome; Toureille, Alain; Rouau, Xavier; Dissado, Len Source: Polymer International, v 53, n 12, December, 2004, p 2169-2177

Application of thermoelectric aging models to polymeric insulation in cable geometry
Cooper, E.S. (Engineering Department, University of Leicester); Dissado, L.A.; Fothergill, J.C. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 12, n 1, February, 2005, p 1-10

Electrical aging and life models: The role of space charge
Mazzanti, G. (DIE-LIMAT, University of Bologna); Montanari, G.C.; Dissado, L.A. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 12, n 5, October, 2005, p 876-890

Investigating charge trapping properties of combinations of XLPE and semiconductive materials in plaques and cable models
Montanari, G.C. (DIE-LIMAT, University of Bologna); Laurent, C.; Teyssedre, G.; Campus, F.; Nilsson, U.; Morshuis, P.H.F.; Dissado, L.A. Source: Proceedings of the International Symposium on Electrical Insulating Materials, v 1, Proceedings of 2005 International Symposium on Electrical Insulating Materials, ISEIM 2005, 2005, p 99-102

Improved simulation model for PD pattern in voids considering effects of discharge area
Wu, Kai (Ctr. for Intgd. Res. in Sci./Eng., Nagoya University); Suzuoki, Yasuo; Dissado, L.A. Source: Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report, 2003, p 32-35

The contribution of discharge area variation to partial discharge patterns in disc-voids
Wu, Kai (Ctr. for Intgd. Res. in Sci./Eng., Nagoya University); Suzuoki, Yasuo; Dissado, L.A. Source: Journal of Physics D: Applied Physics, v 37, n 13, Jul 7, 2004, p 1815-1823

Molecular dynamics simulation of high frequency (1010 to 10 12 Hz) dielectric absorption in the Hollandite Nax(Ti 8-xCrx)O16
Khoo, K.L. (Engineering Department, University of Leicester); Dissado, L.A.; Fothergill, J.C.; Youngs, I.J. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, v 2, Proceedings of the 2004 IEEE International Conference on Solid Dielectrics ICSD 2004, 2004, p 550-553

Percolation model for electrical breakdown in insulating polymers
Wu, Kai (Department of Engineering, University of Leicester); Dissado, L.A.; Okamoto, Tatsuki Source: Applied Physics Letters, v 85, n 19, Nov 8 2004;Nov 8, 2004, p 4454-4456

Erratum: Percolation model for electrical breakdown in insulating polymers (Applied Physics Letters (2004) 85 (4454))
Wu, Kai (Ctrl. Res. Inst. Elec. Pwr. Indust.); Okamoto, Tatsuki; Dissado, L.A. Source: Applied Physics Letters, v 86, n 12, Mar 21, 2005, p 129902

A novel electrical model of nerve and muscle using Pspice
Peasgood, W. (Department of Engineering, University of Leicester); Dissado, L.A.; Lam, C.K.; Armstrong, A.; Wood, W. Source: Journal of Physics D: Applied Physics, v 36, n 4, Feb 21, 2003, p 311-329

Molecular dynamics simulation of high frequency (1010 to 1012 Hz) dielectric absorption in the hollandite Nax(Ti8-xCrx)O16
Khoo, K.L. (Dept. of Eng., Leicester Univ., UK); Dissado, L.A.; Fothergill, J.C.; Youngs, J. Source: Proceedings of the 2004 IEEE International Conference on Solid Dielectrics (IEEE Cat. No.04CH37539), 2004, pt. 2, p 550-3 Vol.2

"Sub-hertz" dielectric spectroscopy
Fothergill, J.C. (Dept. of Eng., Leicester Univ., UK); See, K.B.A.; Ajour, M.N.; Dissado, L.A. Source: Proceedings of 2005 International Symposium on Electrical Insulating Materials (ISEIM 2005) (IEEE Cat. No.05TH8798), 2005, pt. 3, p 821-4 Vol. 3

Investigating charge trapping properties of combinations of XLPE and semiconductive materials in plaques and cable models
Montanari, G.C. (DIE-LIMAT, Bologna Univ., Italy); Laurent, C.; Teyssedre, G.; Campus, F.; Nilsson, U.; Morshuis, P.H.F.; Dissado, L.A. Source: Proceedings of 2005 International Symposium on Electrical Insulating Materials (ISEIM 2005) (IEEE Cat. No.05TH8798), 2005, pt. 1, p 99-102 Vol. 1

Simulation of bipolar charge transport in polyethylene featuring trapping and hopping conduction through an exponential distribution of traps
Boufayed, F. (Lab. de Genie Electr., Univ. Paul Sabatier, Toulouse, France); Leroy, S.; Teyssedre, G.; Laurent, C.; Segur, P.; Dissado, L.A.; Montanari, G.C. Source: Proceedings of 2005 International Symposium on Electrical Insulating Materials (ISEIM 2005) (IEEE Cat. No.05TH8798), 2005, pt. 2, p 340-3 Vol. 2

Elemental strain and trapped space charge in thermoelectrical aging of insulating materials Part 1: Elemental strain under thermo-electrical-mechanical stress
Dissado, L.A. (Department of Engineering, University of Leicester); Mazzanti, G.; Montanari, G.C. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 8, n 6, December, 2001, p 959-965

Understanding electrical trees in solids: From experiment to theory
Dissado, L.A. (Department of Engineering, University of Leicester) Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 9, n 4, August, 2002, p 483-497

Dielectric spectroscopy of epoxy/glass composite materials
Ajour, M.N. (University of Leicester); Dissado, L.A.; Fothergill, J.C.; Norman, P.N. Source: Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report, 2002, p 438-441

Electric field requirements for charge packet generation and movement in XLPE
See, A. (Elec./Electron. Power Eng. Res. Grp., Department of Engineering, University of Leicester); Dissado, L.A.; Fothergill, J.C. Source: IEEE International Conference on Conduction and Breakdown in Solid Dielectrics, 2001, p 232-235

Electroluminescence excitation mechanisms in an epoxy resin under divergent field
Griseri, V. (University of Leicester, Department of Engineering); Dissado, L.A.; Fothergill, J.C.; Laurent, C.; Teyssedre, G. Source: IEEE International Conference on Conduction and Breakdown in Solid Dielectrics, 2001, p 248-251

Elemental strain and trapped space charge in thermoelectrical aging of insulating materials. Life modeling
Mazzanti, G. (Dipartimento di Ingegneria Elettrica, University of Bologna); Montanari, G.C.; Dissado, L.A. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 8, n 6, December, 2001, p 966-971

Predicting electrical breakdown in polymeric insulators: From deterministic mechanisms to failure statistics
Dissado, L.A. (Department of Engineering, University of Leicester) Source: Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report, 2002, p 1-18

Material morphology and energy barriers to electrical ageing
Cooper, E.S. (Department of Engineering, University of Leicester); Fothergill, J.C.; Dissado, L.A.; Hampton, R.N. Source: IEEE International Conference on Conduction and Breakdown in Solid Dielectrics, 2001, p 260-263

Towards an understanding of nanometric dielectrics
Nelson, J. Keith (Department of Engineering, University of Leicester); Fothergill, John C.; Dissado, L.A.; Peasgood, W. Source: Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report, 2002, p 295-298

Understanding electrical trees in solids: From experiment to theory
Dissado, L.A. (Department of Engineering, University of Leicester) Source: IEEE International Conference on Conduction and Breakdown in Solid Dielectrics, 2001, p 15-26

Controlling flashover between electrode segments in DC power capacitors
Grafton, M.A. (Elec./Electron. Power Eng. Res. Grp., Department of Engineering, University of Leicseter); Fothergill, J.C.; Dissado, L.A.; Shirley-Elgood, J.R.R.; Stevens, G.C.; Thomas, J.L. Source: IEEE International Conference on Conduction and Breakdown in Solid Dielectrics, 2001, p 279-282

Measurement of space-charge distributions in solid insulators under rapidly varying voltage using the high-voltage, high-speed pulsed electro-acoustic (PEA) apparatus
See, A. (Department of Engineering, Elec./Elctrnc. Power Eng. Res. Group, University of Leicester); Fothergill, J.C.; Dissado, L.A.; Alison, J.M. Source: Measurement Science and Technology, v 12, n 8, August, 2001, p 1227-1234

Electroluminescence excitation mechanisms in an epoxy resin under divergent and uniform field

Griseri, V. (University of Leicester, Department of Engineering); Dissado, L.A.; Fothergill, J.C.; Teyssedre, G.; Laurent, C. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 9, n 1, February, 2002, p 150-160

Erratum: Elemental strain and trapped space charge in thermoelectric ageing of insulating materials life modeling (IEEE Transactions on Dielectrics and Electrical Insulation (2001) 8 (966-971)
Mazzanti, G.; Montanari, C.; Dissado, L.A. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 9, n 3, June, 2002, p 481

The relationship between charge distribution, charge packet formation and electroluminescence in XLPE under DC
See, A. (University of Leicester); Dissado, L.A.; Fothergill, J.C.; Teyssedre, G.; Laurent, C.; Montanari, G.C.; Palmieri, F. Source: IEEE International Conference on Conduction and Breakdown in Solid Dielectrics, 2001, p 97-100

Electroluminescence excitation mechanisms in an epoxy resin under divergent field
Chiseri, V. (Dept. of Eng., Leicester Univ., UK); Dissado, L.A.; Fothergill, J.C.; Laurent, C.; Teyssedre, G. Source: ICSD'01. Proceedings of the 20001 IEEE 7th International Conference on Solid Dielectrics (Cat. No.01CH37117), 2001, p 248-51

Improvement of PEA signal analysis using simulations for complex geometry samples
Hole, Stephane (Lab. Instrum. Syst. d'lle de France, Universite Pierre et Marie Curie, ESPCI); Griseri, Virginie; Dissado, Leonard A.; Fothergill, John C. Source: Journal of Physics D: Applied Physics, v 35, n 1, Jan 7, 2002, p 19-24

Application of polymer ageing models to power cables
Cooper, E.S. (Department of Engineering, University of Leicester); Fothergill, J.C.; Dissado, L.A. Source: Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report, 2002, p 392-395

Deterministic chaos in breakdown does it occur and what can it tell us?

Dissado, L.A. (Department of Engineering, The University of Leicester) Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 9, n 5, October, 2002, p 752-762

Deep trapping centers in crosslinked polyethylene investigated by molecular modeling and luminescence techniques

Teyssedre, G. (Lab. de Genie Electr., Univ. Paul Sabatier, Toulouse, France); Laurent, C.; Aslanides, A.; Quirke, N.; Dissado, L.A.; Montanari, G.C.; Campus, A.; Martinotto, L. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 8, n 5, Oct. 2001, p 744-52

Electric field criteria for charge packet formation and movement in XLPE
See, A. (Department of Engineering, University of Leicester); Dissado, L.A.; Fothergill, J.C. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 8, n 6, December, 2001, p 859-866

Predicting electrical breakdown in polymeric insulators from deterministic mechanisms to failure statistics

Dissado, L.A. (Department of Engineering, The University of Leicester) Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 9, n 5, October, 2002, p 860-875

Photoluminescence, recombination induced luminescence and electroluminescence in epoxy resin

Griseri, V. (University of Leicester, Department of Engineering); Dissado, L.A.; Fothergill, J.C.; Laurent, C.; Teyssedre, G. Source: Journal of Physics D: Applied Physics, v 34, n 16, Aug 21, 2001, p 2534-2540

Charge distribution and electroluminescence in cross-linked polyethylene under dc field

Teyssedre, G. (Universite Paul Sabatier, Laboratoire de Genie Electrique); Laurent, C.; Montanari, G.C.; Palmieri, F.; See, A.; Dissado, L.A.; Fothergill, J.C. Source: Journal of Physics D: Applied Physics, v 34, n 18, Sep 21, 2001, Future of technological plasmas, p 2830-2844

The fractal analysis of water trees: an estimate of the fractal dimension

Lanca, M.C. (Dept. de Ciencia dos Mater., Univ. Nova de Lisboa, Portugal); Marat-Mendes, J.N.; Dissado, L.A. Source: IEEE Transactions on Dielectrics and Electrical Insulation, v 8, n 5, Oct. 2001, p 838-44

 

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This document has been approved by the Head of Department.