PREFACE

A. Jakoviċs - J. Virbulis

Faculty of Physics and Mathematics University of Latvia

Abstract
<p> The application of numerical methods and the use of computers in mathematical modelling of environmental and technological processes have a very long tradition at the University of Latvia. The history of these activities traces back to the end of the 1950's when the {\sl Computing Center} of the University of Latvia was founded, and the first mainframe computers (series {\sl BESM}) appeared there. From the very beginning, physicists were among the most active users of that new equipment. The purpose of those activities was industrial research and they led to the foundation of the Chair of {\sl Electrodynamics and Continuum Mechanics} at the University of Latvia in 1970. Among the founders of the Chair were the physicists not only from the University, but also from the {\sl Institute of Physics} and {\sl Institute of Polymer Mechanics}, with ideas for different industrial applications of numerical models. The established contacts with researchers in engineer sciences and the active collaboration with leading institutions in applied research and development in Moscow, Leningrad and Kiev in the 1970's and 1980's had been very fruitful and it was one of the major reasons of the success of this research direction at the University of Latvia. <p> In the beginning of the 1990's when all research institutions in Latvia underwent dramatic changes, not all ideas and institutions could adapt successfully to the new conditions. Fortunately, the people who were involved in computer modelling related research were among the most successful. The development of already existing and newly established contacts in Western Europe and the reorientation of their applied research to the disciplines actively studied in partner universities contributed greatly to the financing of our research activities. The first agreement on scientific collaboration with a university from the West was signed in 1988 -- it was the agreement between the Faculty of Physics and Mathematics of University of Latvia and the {\sl Institute of Electroheat} of University of Hannover (nowadays {\sl Institute of Electrotechnology} of Leibnitz University Hannover) in the field of numerical modelling aimed at solving different engineering problems in metallurgy and semiconductor industry. This collaboration has been very successful and has various forms nowadays. There are common projects, scientific conferences and publications, exchange of researchers, etc. As a result, the research groups involved have successfully joined the international effort related to the application of computer models to industrial processes. <p> As a next logical step to concentrate the research activities in this field at the Faculty of Physics and Mathematics, the {\sl Laboratory for Mathematical Modelling of Environmental and Technological Processes} was founded in 1994. Currently, engineering physics, the core of which is the multiphysical modelling of environmental and technological processes in the Laboratory with more than 25 researchers and PhD students, is one of the largest successfully developing scientific directions at the {\sl Faculty of Physics and Mathematics} of the University of Latvia. <p> Continuing the tradition established by the international scientific colloquia {\sl Modelling for Materials Processing} in Riga (1999, 2001, 2006, 2010) and {\sl Modelling for Electromagnetic Processing} in Hannover (2003 and 2008, 2014), the University of Latvia with its long-time cooperation partner {\sl Institute for Electrotechnology} of Leibnitz University Hannover organized the 8th Colloquium on {\sl Modelling for Materials Processing} in Riga in September 2017. <p> During the colloquium, recent results of numerical and experimental research activities in the field of industrial technologies aimed at creating new and alternative materials, materials with highest quality and purity and new innovative products were presented. Two colloquium sessions discussed the new achievements in crystal growth. Traditionally, applications in metallurgy were also presented, especially on the base of multiphysics models with the strong interaction of different physical processes (thermal, electromagnetic and hydrodynamic). Many researches investigating the processes in multiphase materials with the movement of phase interfaces and melting/ crystallization have provided successful results. The latest colloquium also has allowed young researchers and PhD students to present and discuss in detail the numerical and experimental methods and approaches. <p> The newest results on numerical and physical modelling in these fields are presented in the current issue including 16 papers selected for publication in the international scientific journal "Magnetohydrodynamics".