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List of Publications


PhD Thesis

Modelling of the Microphysical Processes that Lead to Warm Rain Formation, 1998, UMIST, Manchester


Refereed Journal Papers

  1. Liperovskaya, E.V., N. Christakis, V. Liperovsky, M. A. Oleynik, 1994a: The effects of seismic and anthropogenic activity on the sporadic E-layer of the ionosphere (in Russian). Geomagnetism i Aeronomia, 3, 34, p.56-59. [view in PDF format]

  2. Christakis, N, N.W.H. Allsop, R.G. Beale, A.J. Cooper, J.M. Dennis, 2002a: A Volume of Fluid Numerical Model for Wave Impacts at Coastal Structures. Water & Maritime Engineering 154, 3, p. 159-168. [view in PDF format]

  3. Christakis, N, M.K. Patel, M. Cross, J. Baxter, H. Abou-Chakra, U. Tüzün 2002b:  Predictions of Segregation of Granular Material with the aid of PHYSICA, a 3-D Unstructured, Finite-Volume Modelling Framework , Int. J. Numer. Meth. Fluids 40, p. 281-291.  [view in PDF format]

  4.  Chapelle, P., H. Abou-Chakra, N. Christakis, M.K. Patel, A. Abu-Nahar, U. Tüzün, M. Cross, 2004a: Computational model for prediction of particle degradation during dilute phase pneumatic conveying. The use of a laboratory scale degradation tester for the determination of degradation propensity Advanced Powder Technology 15, 1, 13-30.    [view in PDF format]

  5. Chapelle, P., N. Christakis, H. Abou-Chakra, I. Bridle, M.S.A. Bradley, M.K. Patel, M. Cross, 2004b: Computational model for prediction of particle degradation during dilute phase pneumatic conveying.  Modelling of dilute phase pneumatic conveying Advanced Powder Technology 15, 1, 31-50.   [view  in PDF format]

  6. Chapelle, P., H. Abou-Chakra, N. Christakis, I. Bridle, M.K. Patel, J. Baxter, U. Tüzün, M. Cross, 2004c  Numerical predictions of particle degradation in industrial scale pneumatic conveyors, Powder Technology 143-144, 321-330. [view in PDF format]

  7. Wang, J., N. Christakis, M.K. Patel, M.C. Leaper, M. Cross, 2004d: A Computational Model of Coupled Heat and Moisture Transfer with Phase Change in Granular Sugar During Varying Environmental Conditions Numerical Heat Transfer, Part A, 45, 8, p. 751-776.   [view in PDF format]

  8. P. Chapelle, N. Christakis, J. Wang, N. Stroussevitch, M.K. Patel, M. Cross, H. Abou-Chakra, J. Baxter, U. Tuzun, 2005: Application of simulation technologies in the analysis of granular material behaviour during transport and storage, Proceedings of I MECH E, Part E, Journal of Process Mechanical Engineering, 219 (1), p. 43-52. [view in PDF format]

  9. Haldoupis, C., C. Meek, N. Christakis, D. Pancheeva, A. Bourdillon, 2006a: Ionogram height-time intensity observations of descending sporadic E layers Journal of Atmospheric and  Solar-Terrestrial Physics, 68, p. 539-557. [view in PDF format]

  10. Christakis, N., P. Chapelle, M.K. Patel, 2006b: Analysis and Modelling of Heaping Behaviour of Granular Mixtures, Advanced Powder Technology, 17, 4, p.383-398. [view in PDF format]

  11. Christakis N., Wang, J., M.K. Patel, M.S.A. Bradley, M.C. Leaper, M. Cross, 2006c: Aggregation and Caking Processes of Granular Material: Continuum Model and Numerical Simulation with Application to Sugar, Advanced Powder Technology 17, 5, p.543-565. [view in PDF format]

  12. Christakis Ν., P. Chapelle, N. Strusevich, I. Bridle, J. Baxter, M.K. Patel, M. Cross, U. Tüzün, A.R. Reed, M.S.A. Bradley, 2006d: A hybrid numerical model for predicting segregation during core flow discharge, Advanced Powder Technology 17, 6, p.641-662. [view in PDF format]

  13. Cross M., T.N. Croft, A.K. Slone, A.J. Williams, N. Christakis, M.K. Patel, C. Bailey, K. Pericleous, 2007a: Computational Modelling of Multi-Physics and Multi-Scale Processes in Parallel, International Journal for Computational Methods in Engineering Science and Mechanics 8, p.1-12. [view in PDF format]

  14. A. Vairis, Christakis N., 2007b: The development of a continuum framework for friction welding processes with the aid of micromechanical parametrisations. International Journal of Modelling, Identification and Control 2, 4, p.347-355.  [view in  PDF format]

  15. Christakis N., A. Vairis, 2007c: An analytical description of the Frictional Behaviour of a Titanium Alloy. Research Letters in Material Science.  Article ID 92170, 4 pages, doi:10.1155/2007/92170. [view in  PDF format]

  16. Christakis N., C. Haldoupis, Q. Zhou, C. Meek, 2009: Variability and descent of mid-latitude sporadic E layers at Arecibo. Ann. Geophys., 27, 923-931, 2009. [view in PDF format]

  17. Christakis N., V. Barbaris, A. Spentzos, 2011: A new approach in financial modelling with the aid of artificial neural networks. Journal of Algorithms and Computational Science, 5, 3, 513-529.
  18. Christakis N., M.K. Patel, M. Cross, U. Tuzun, 2013: A Hybrid Approach for the Modelling of Complex Systems. Journal of Algorithms and Computational Science, 7, 2, 113-123.

  19. Herbrych J., A. Hazirakis, N. Christakis, J.J.P. Veerman, 2017: Dynamics of locally coupled agents with next nearest neighbor interactions. Differential Equations and Dynamical Systems. DOI: 10-1007/s12591-017-0377-3.

  20. Fraile A., E. Panagiotakis, N. Christakis, L. Acedo, 2018: Cellular automata and artificial brain dynamics. Mathematical and Computational Applications, 23, 4.

  21. Christakis N., M. Politis, P. Tirchas et al., 2021a: COVID-LIBERTY, A Machine Learning Computational Framework for the Study of the Covid-19 Pandemic in Europe. Part 1: Building of an Artificial Neural Network and Analysis and Parametrization of Key Factors which Influence the Spread of the Virus. International Journal of Neural Networks and Advanced Applications, 8, p.13-26. [view online]

  22. Christakis N., P. Tirchas, M. Politis et al., 2021b: COVID-LIBERTY, A Machine Learning Computational Framework for the Study of the Covid-19 Pandemic in Europe. Part2: Setting up the Framework with Ensemble Modeling. International Journal of Neural Networks and Advanced Applications, 8, p.27-42 [view online]

  23. Christakis N., P. Tirchas, M. Politis, G. Kossioris, 2021c: Utilizing Machine Learning to Study the Effects of Vaccination against Covid-19: A Preliminary Study. International Journal of Mathematics and Physics, 1, 1, p.13-18. [view online]


 

Refereed Conference Papers

  1. Waller, M.N.H., N. Christakis, N.W.H. Allsop, R.G. Beale, J.M. Dennis, 1998: Development and Validation of a Numerical Model of Wave Dynamics. 17th Innternational Conference on Offshore Mechanics and Arctic Engineering, ASME, Lisbon (OMAE98-4086, 9 pages).

  2. Christakis, N, M.K. Patel, M. Cross, U. Tüzün, J. Baxter, H. Abou-Chakra 2001: Continuum Modelling of Granular Flows using PHYSICA, a 3-D Unstructured, Finite-Volume Code. In: M.Cross, J.W. Evans, C.Bailey (Eds)  Computational Modeling of Materials, Minerals and Metals Processing, San Diego, CA, TMS, p.129-138.

  3. Christakis, N,  P. Chapelle, M.K. Patel, M. Cross, I. Bridle, H. Abou-Chakra, J. Baxter 2002:  Utilising Computational Fluid Dynamics (CFD) for the Modelling of Granular Material in Large-Scale Engineering Processes. In: P.M.A. Sllot, C.J.K. Tan, J.J. Dongara, A.G. Hoekstra (Eds). Lecture Notes in Computer Science 2329: Computational Science-ICCS 2002, Springer-Verlag Berlin Heidelberg, p. 743-752. [view  in PDF format]

  4. P. Chapelle,  N. Christakis, H. Abou-Chakra, U. Tüzün, I. Bridle, M.S.A. Bradley, M.K. Patel, M. Cross, 2003: Computational Modelling of Particle Degradation in dilute phase pneumatic conveyors (in Proceedings of ICCSA2003) Computational Modelling of Particle Degradation  In: V. Kumar, M.L. Gavrilova, C.J.K. Tan, P. L. Ecuyer (Eds). Lecture Notes in Computer Science 2667: Computational Science and Its Applications-ICCSA 2003, Springer-Verlag Berlin Heidelberg,  pp. 493-502. [view in PDF format]

  5. Christakis, N., P. Chapelle, M.K. Patel, M. Cross 2006: On the continuum modelling of segregation of granular mixtures during hopper emptying in core flow mode. In: P. Wesseking, E. Onate, J. Periaux (Eds), ECCOMAS CFD 2006, TU Delft, Netherlands. [view in PDF format]

  6. Christakis N., A. Vairis, Z. Kountouriotis, 2007: A study of the frictional behaviour of a titanium alloy with the use of an analytic contact model. In: N. Bazeos D. L. Karabalis D. Polyzos, D. E. Beskos, J.T. Katsikadelis (eds.)  Proceedings of 8th HSTAM International Congress on Mechanics, Patras, Greece 12 - 14 July, 2007, p.623-628
  7. Christakis N., M.K. Patel, M. Cross, U. Tuzun, 2010: On the Modelling of Complex Systems: Methodologies and Applications. In: Proceedings of the Ninth International Symposium on Distributed Computing and Applications to Business Engineering and Science, DCABES 2010, p.40-45, ISBN: 978-0-7695-4110-5.

  8. Benas N., N. Chrysoulakis, N. Christakis, G. Kossioris, M. Plexousakis, 20014a: WRF input parameter updates based on recent and long-term satellite observations In: M. Kanakidou  et al. (eds.) Proceedings of 12th International Conference on Meteorology, Climatology and Atmospheric Physics, Heraklion, Greece, May 2014. [view in PDF format]

  9. Christakis N., T. Katsaounis, G. Kossioris, M. Plexousakis, 2014b:   On the Performance of the WRF Numerical Model Over Complex Terrain on a High Performance Computing Cluster Ιn: Proceedings of the 16th IEEE International Conference on High Performance Computing and Communications, p. 298-303, DOI: 10.1109/HPCC.2014.53. [view in PDF format]


 

Non-Refereed Conference Papers

  1. Christakis, N., M.N.H. Waller, R.G. Beale, J.M. Dennis, 1998a: Analysis of the impact of waves on the underside of decks using the Volume of Fluid (VOF) method. Computational Mechanics in UK, 6th Annual Conference of Association for Computational Mechanics in Engineering (ACME), Exeter, p.133-137.

  2. Christakis, N., M.N.H. Waller, R.G. Beale, J.M. Dennis, 1998b: The Application of the Volume of Fluid Method to Wave Dynamics at Impermeable Coastal Structures. In: Baines, M.J. (Ed), Numerical Methods for Fluid Dynamics VI, ICFD, Oxford, p.269-276.

  3. Christakis, N, A.J. Cooper, R.G. Beale, J.M. Dennis, 1999a: Improved Numerical Algorithms for Free Surface Modelling Using the Volume of Fluid Method. In: Bettess, P. (Ed.) 7th Annual Conference of Association for Computational Mechanics in Engineering (ACME), Van Mildert College, University of Durham, Penshaw Press, p.51-58.

  4. Christakis, N, M.K. Patel, M. Cross, J. Baxter, M. Biggs, U. Tüzün, 2000:  On the Continuum Modelling of Granular Flows With the Aid of Micro-mechanical Parametrisations. In Cross, M. (Ed.)  8th  Annual Conference of Association for Computational Mechanics in Engineering (ACME),  University of Greenwich, p.167-170.

  5. Christakis, N, M.K. Patel, M. Cross, 2001a:  Segregation Predictions for a Binary Mixture of Granular Material under Flow Conditions in a Continuum Mechanics Framework.  In  ECCM-2001, 2nd European Conference on Computational Mechanics (Solids, Structures and Coupled Problems in Engineering), Cracow,  Poland.

  6. Christakis, N, M.K. Patel, M. Cross, 2001b:  Predictions of Segregation of Granular Material with the aid of PHYSICA, a 3-D Unstructured, Finite-Volume Modelling Framework.  In: M.J. Baines(Ed.) Numerical Methods for Fluid Dynamics VII , p.263-272, ICFD, Oxford, UK.

  7. Christakis, N,  P. Chapelle, M.K. Patel, J. Wang, M. Cross, J. Baxter, T. Groger, H. Abou-Chakra, U. Tüzün, I. Bridle, M. Leaper 2002a: Mathematical Modelling of the Behaviour of Granular Material in a Computational Fluid Dynamics Framework using Micro-Mechanical Models, Proceedings of the Fifth World Congress on Computational Mechanics (WCCM V), July 7-12, 2002, Vienna, Austria, Editors: Mang, H.A.; Rammerstorfer, F.G.; Eberhardsteiner, J., Publisher: Vienna University of Technology, Austria, ISBN 3-9501554-0-6, http://wccm.tuwien.ac.at  [view in PDF format]

  8. Baxter, J., T. Groger, U. Tüzün, H. Abou-Chakra, N. Christakis, M.K. Patel, M. Cross, 2002b: Micro-Mechanical Parameterisations for Continuum Modelling of Granular Material using the Discrete Element Method, Proceedings of the Fifth World Congress on Computational Mechanics (WCCM V), July 7-12, 2002, Vienna, Austria, Editors: Mang, H.A.; Rammerstorfer, F.G.; Eberhardsteiner, J., Publisher: Vienna University of Technology, Austria, ISBN 3-9501554-0-6, http://wccm.tuwien.ac.at  [view in PDF format]

  9. Christakis, N., T.N. Croft, M.K. Patel, 2002c: A new unstructured algorithm based on the Volume of Fluid method for tracking material interfaces in a finite-volume framework,  In: R. Herbin & D. Kroner (Eds) Finite Volumes for Complex Applications III (Third International Symposium on Finite Volumes for Complex Applications , Porquerolles, France), p. 487-494, Hermes Penton Ltd.. London UK. [view in PDF format]

  10. Vairis A., N. Christakis, 2005a: Recent Advances on Friction Modelling within a Computational Mechanics Framework. In Proceedings of 1st IC-EpsMsO, Athens Greece [view in PDF format]

  11. Christakis N., A. Vairis, 2005b: The application of computer-aided methodologies in industrial process optimisation. In: Papadourakis, Lazaridis (Eds) Proceedings of the 4th International Conference on New Horizons in Industry, Business and Education, Corfu, Greece, p.322-328.

  12. Christakis N., P. Chapelle, M.K. Patel, 2006a: A Computational Study of Segregation in Granular Material During Heaping. In: CD-Rom: 5th World Congress on Particle Technology, New York, MY, AICHE.

  13. Patel, M.K., N. Christakis, P. Chapelle, M. Cross, 2006b: Towards a Better Understanding of Granular Material Processes: The Coupling of a Computational Fluid Dynamics Framework with Micro-Mechanical Models. In: Proceedings of the 5th International Conference on Conveying and Handling of Particulate Solids, 2006, Sorrento, Italy.

 

Posters

  1. Christakis, N., V.A. Liperovsky, E.V. Liperovskaya, K.V. Popov, C.V. Meister, L.N. Rubtsov, 1996: On the distortion of the ionosphere by earthquake preparation and anthropogenic activity. Poster at MHD Reconnection Summer School, September 1996, St. Andrews, Scotland.

  2. Christakis N., C. Haldoupis,  Q. Zhou, C. Meek, 2008: Variability and descent of mid-latitude sporadic E layers at Arecibo. Poster at 12th International Symposium on Equatorial Aeronomy, May 2008, Crete, Greece.