March 2015

"Entropic" solutions for two-phase fluids flows, phase transitions, and damage by Elisabetta Rocca

October 2014

Christof Eck by Christian Rohde

September 2014

Minimization vs. Null-Minimization: a Note about the Fitzpatrick Theory by Augusto Visintin

July 2014

Piero Villaggio 30 December 1932 - 4 January 2014 by Robin J. Knops and Carmine Trimarco

List of publications of Piero Villaggio

May 2014

Krzysztof Wilmanski and CMwM2015 by Bettina Albers

Jan 2014

Commemoration of Professor Jean Jacques Moreau (1923-2014) by Olivier Maisonneuve

ISIMM Prize 2014, Junior ISIMM Prize 2014 by Augusto Visintin

June 2013

May 2013: a month with hysteresis by Michela Eleuteri

A remark to Michela Eleuteri's note by Augusto Visintin

by Elisabetta Rocca (Berlin and Milano)

Abstract. In the recent publications [2] and [13], we have introduced a weak notion of solution, called "entropic solution", of diffuse interface models for applications relevant phenomena like the evolution of two viscous incompressible fluids and phase transitions and damage in thermoviscoelastic materials.

This solvability concept reflects the basic principles of thermomechanics, as well as the thermodynamical consistency of the models. It allows us to obtain global-in-time existence theorems without imposing any restriction on the size of the initial data.

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24 April 1968 - 14 September 2011.

by Christian Rohde (Stuttgart)

Christof Eck studied mathematics at the Universities of Konstanz and Stuttgart. Then he joined the research group of Wolfgang Wendland in Stuttgart, where he received his doctoral degree in 1996 with a thesis on contact problems with friction. This topic from modern mechanics attracted him for his entire scientific life and he published more than fifteen papers on the subject in leading journals. He established as major contribution a rigorous existence theory of weak solutions by variational methods that could be applied to lots of applications. The analysis relies on regularization, a priori estimates for the approximate solutions and the use of the shift method on the boundary. A large part of this work has been done in a longstanding co-operation with colleagues from Prague, in particular with Jiri Jarusek. Together with Miroslav Krbec they authored also a monography on the mathematical theory of contact problems that sets standards in the field.

Leaving Stuttgart he acted from 1998 to 2007 as an assistant professor at the Friedrich-Alexander University of Erlangen-Nuremberg in the group of Peter Knabner. There he accomplished in 2004 his habilitation thesis on two-scale phase field models for dendritic growth. Phase field modelling, homogenization and the related asymptotic analysis became from then on his second major field of research. He was the first to develop and analyze rigorously multiscale settings which could be successfully applied to the description of dendritic

growth, epitactic processes and dissolution/precipitation phenomena in porous media. His multiscale analysis not only paves the way to construct efficient and reliable numerical schemes but also found the interest of researchers from computational engineering. In particular with his co-author Heike Emmerich he started a very fruitful interdisciplinary research on epitaxy.

During his time in Erlangen Christof Eck became more and more involved in the mathematical education of students. Jointly with Harald Garcke and Peter Knabner he composed a book on mathematical modelling for undergraduate students. This monography (written in German) is by now the basics for many courses and seminars at German-speaking universities. It is that successful because it precisely fills a gap in teaching between the mathematical modelling issues which can be taught in lectures and those which are learned from practical computational studies.

In 2007 he was appointed Professor for Mathematics at the University of Bielefeld, But only one year later in 2008 he follows an offer of the University of Stuttgart as Professor for Numerical Mathematics. Here, he very quickly established a working group consisting of diploma and PhD students. He became fellow of the SimTech Cluster of Excellence at the University of Stuttgart where he substantially strengthens the cooperation between applied mathematics and the colleagues from the civil engineering departments.

His scientific contributions to the fields of contact mechanics and phase transition theory received worldwide appreciation. He was in the forefront of researchers on nonlinear contact problems in solid mechanics as well as on multi-scale modeling for dendritic growth and phase-field approximations for a wide range of applications. All of his work is characterized by outstanding mathematical depth as well as by interdisciplinary orientation. Christof Eck was hardworking, author of more than 50 research papers and two textbooks. He was a member in several research initiatives funded by the German Research Foundation.

He had close scientific contacts to various research groups in Prague, Lyon, Pittsburgh, Madrid, Trento, and of course within Germany.

Christof Eck died on the 14th September 2011 after a long cancer disease.

Institut für Angewandte Analysis und numerische Simulation

Fachbereich Mathematik

Universität Stuttgart

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by Augusto Visintin (Trento)

Abstract. After a result of Fitzpatrick, for any maximal monotone operator \( \alpha : V \to \mathcal {P}(V') \) there exists a function \( J_\alpha : V \times V' \to \mathbb{R} \cup \{+\infty\}\) such that $$J_\alpha(v,v')=\inf J_\alpha=0 \quad\Leftrightarrow\quad v' \in \alpha(v).$$ Here we discuss the prescription of the minimum value.

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30 December 1932 - 4 January 2014.

by Robin J. Knops (Edinburgh) and Carmine Trimarco (Pisa)

Piero Villaggio, after a short illness, died on 4 January 2014 in Rapallo, Italy. He was born on 30 December 1932 in Genoa, twin to his brother Paolo.

His father, Ettore, was an accomplished surveyor and later an eminent construction engineer who came from Palermo. His mother, Maria Faraci, originally from Venice, was a language teacher. Piero, who attended the famous Liceo Ginnasio Andrea D'Oria in Genoa, graduated in 1957 from the University of Genoa with a degree in Civil Engineering, having taken his applied mathematics course under Guido Stampacchia, and defended his thesis on hydraulics supervised by Enrico Marchi. In 1966, he was appointed to a professorship in the Strength of Materials in the Department of Structural Engineering of the University of Pisa. There he joined the rapidly developing research group devoted to modern continuum mechanics that not only continued but enhanced the Italian tradition and strongly interacted with Clifford Truesdell and other members of the North American school. Piero himself held visiting professorships at Johns Hopkins University and the University of Minnesota at Minneapolis, and also made short visits to other departments including that at Heriot-Watt University, Edinburgh. The main part of his career, however, was spent in Pisa where his teaching included courses in structural engineering and aerodynamics in the University, and in fluid dynamics and continuum mechanics in the Scuola Normale. On his official retirement, he was appointed to an emeritus chair in the University of Pisa. In September 1998 he was elected a corresponding member of the Accademia dei Lincei, and in 2011 became a full member.

His working week commenced with an extremely early Monday morning departure from his home in Genoa shared with his wife, Rosa Maria née Pertusio, known affectionately always as Omi, and to whom he was devoted. They had married in 1962 and Piero received from Omi greatly appreciated unwavering support throughout their long life together. He was at his desk in Pisa invariably by 08.00 each day, where usually he could be found except between 12.00 and 15.00 which was exclusively reserved for his great passion of rock-climbing. He was a renowned climber and distinguished member of the Italian Academic Alpine Club, and when younger often spent summers in the Alps and Dolomites. After his daily excursion, Piero returned and remained at his desk unless interrupted by teaching duties until about 18.30 or 19.00 when he adjourned for dinner either at some specially selected restaurant or at the students' mensa in the Scuola Normale. On such occasions, in addition to food, he enjoyed invigorating conversation with Ennio DeGiorgi and other equally stimulating colleagues. At the end of the week he returned to Genoa.

His preferred personal dress, except on formal occasions, was invariably simple. In winter, corduroy trousers and jersey; in summer, much less. Unlike his twin, he was clean-shaven with hair kept disappearingly short.

Piero was an internationally recognised expert with an outstanding reputation in linear elasticity and its applications, and more generally, in mechanics, its history, the evolution of principles, and modern developments. The succinct history of linear elasticity, written as part of his book Qualitative Methods of Elasticity ( Noordhoff 1977), is exemplary. He was convinced that understanding fundamental principles was of vital importance. In the introduction to the same book, he wrote "A more spontaneous understanding of a theory results when we are able to recognise the motivation behind a particular problem or its generalisation instead of being presented with a formal development.'' His approach employed a deep understanding of basic mechanics to simplify a problem without sacrificing essential elements. He then selected the most appropriate mathematical technique to derive a meaningful solution, refusing to become distracted by mathematical arguments, of which he possessed impressive command, that do little to enhance physical understanding. He strove always for, and successfully achieved, elegance in argument and in brevity of presentation. Prolixity was anathema.

He was the author or co-author of over one hundred and forty research papers, covering a vast range of topics including unilateral problems, friction, detachment of bodies, elastic plates, plasticity, viscoelasticity, inequalities, Saint-Venant's principle, stability, impact of moving bodies, history of mechanics, and pedagogy. A full list of publications is appended and also may be found in the August 2014 issue of the Journal of Elasticity. The selection of problems and their mathematical treatment were remarkably original, and frequently independent of mainstream activity. The choice displayed impeccable physical insight that facilitated the application of effective but simple mathematical techniques. As with most of his papers, diagrams, drawn in his own inimitable style, enrich the text. He remained active until the very end, and indeed among his final papers is one that still awaits publication in the Journal of Engineering Mechanics.

Apart from his research articles, Piero was responsible for three erudite books. One has been mentioned already. The second is the comprehensive Mathematical Methods of Elastic Structures (Cambridge University Press 1997), while the third is the authorative commentary Die Werke von Johannes Bernoulli: Mechanics (Birkhausner 2007), published as part of a series to commemorate the anniversary of the Bernoulli brothers. Piero's critical evaluation of Johannes Bernoulli's contributions to mechanics is achieved by incisive scholarship and profound understanding of seventeenth and eighteenth century scientific thought.

Editorial duties involved the refereeing and review of books and research articles, as well as dedicated service on numerous editorial boards, such as those of Meccanica, the ASCE Journal of Engineering Mechanics, the Journal of Elasticity, and the Journal of Nonlinear Differential Equations and their Applications.

He willingly gave his time and care to the education and encouragement of his students, inspiring many to develop highly successful careers. Moreover, academics and non-academics alike regularly sought his wise advice and were seldom, if ever, disappointed. A modest personality concealed immense charm and warmth. He was spontaneously hospitable and genuinely enjoyed the company of others. Conversations with him were a delight, fueled by a reflective and extensive knowledge that besides mathematics and engineering, embraced philosophy, history, politics, and literature.

The gradual erosion of mechanics from school and university syllabuses was of deep concern, and he acted to reverse the decline. In 2000, he wrote an open letter strongly deploring the so-called reform of the general university system and the adverse effect on engineering and mechanics. In 2009, he delivered public lectures in Udine and Reggio Calabria demonstrating the contemporary significance of mechanics and vigorously arguing why it must be retained as part of a complete general education. One of his final lectures was in the months before his death to an audience of school leavers, school teachers and academics on the same risks. This typified his active commitment and robust spirit that clearly emerged whenever he perceived retrogressive trends that required to be opposed.

In 2012, he underwent lung surgery from which he recovered only to suffer a serious fall and broken leg in November 2013. He returned by ambulance to Genoa and spent his final weeks at home with Omi in a city of which he was inordinately proud.

He was a natural Natural Philosopher and a perfect ISIMM member. His memory and influence will long be remembered and cherished.

School of Mathematical and Computer Sciences,

Heriot-Watt University, Edinburgh

Dipartimento di Matematica,

Università di Pisa

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by Bettina Albers (Berlin)

In memory of Professor Krzysztof Wilmanski, the

2nd International Conference on Continuous Media with Microstructure – CMwM2015

will be held from 2 to 5 March 2015 in his home country Poland.

Krzysztof Wilmanski in Łagόw where the International Conference CMwM2015 will take place |

On 1 March 2015 Krzysztof Wilmanski would have celebrated his 75th birthday. However, on 26 August 2012 he passed away quite unexpectedly after a short battle with cancer. He learned with initial disbelief of the devastating diagnosis only three and a half months before his death. I still can hear him expressing the wish that the spots revealed on the X-rays were harmless and medically treatable. Notwithstanding the stomach pain that prompted his initial visit to the doctor he had many plans and ideas for the future. But despite intensive efforts to arrest its progress, it soon became clear that the disease could not be stopped.

Throughout all this period, we worked on our joint book project “Continuum Thermodynamics. Part II“. In 2008 Krzysztof had already published Part I, and I and Mietek Kuczma promised to write Part II and Part III. Krzysztof eagerly anticipated that the two remaining parts would be completed in the foreseeable future. But I was not able on my own to finish my part on time and, therefore, Krzysztof and I agreed to write Part II together. It was very important to both of us to finish the book but, unfortunately, time did not permit... Work is once again underway to complete our joint work and present it at CMwM2015.

The variety of fields in which Krzysztof achieved original contributions is wide, and, thus also the range of topics covered in CMwM2015. Krzysztof, a distinguished scientist and teacher, loved mechanics and among his other works achieved significant contributions to continuum thermodynamics, mixture theory and the modeling of porous media. He worked at various places in his home country Poland, in Germany and around the world. Besides his birthplace, Lodz, and Warsaw where he lived with his family for several years, Berlin was surely a very important place for Krzys. There he not only worked with Ingo Müller at TU Berlin (partly with a Humboldt grant) but he also spent a year as fellow in the renowned “Wissenschaftskolleg zu Berlin“ and, for almost ten years, he was the head of the research group “Continuum Mechanics“ at the Weierstrass Institute for Applied Analysis and Stochastics. During this time, students of TU Berlin had the priviledge of attending his enthusiastically presented courses on continuum mechanics, thermodynamics and wave propagation.

Krzysztof studied Civil Engineering at TU Lodz, where he also obtained the PhD in 1965. In 1970 he obtained his habilitation at the Polish Academy of Sciences. Recently I learned in Poland that Krzysztof is one of the youngest persons ever nominated in 1979 at the age of 39 as professor by the Polish state council. Among the important stages in his scientific life were the stay at the Johns Hopkins University where he met C. Truesdell and J. Ericksen, two years at the University of Bagdad, and lastly some years teaching at the University of Zielona Gora, the Technion in Haifa, and, as a faculty member of the ROSE School, in Pavia.

Krzysztof was not only scientifically quite active, for he loved not only long bicycle rides, which he undertook almost daily in his later years, but also traveling in foreign countries or in his home country Poland. The latter were done mostly in his personal auto, especially at Christmas, when it served to transport of all the delicacies which his wife Anna produced in weeks of work, for the whole family in Poland. I remember happily those times when I had the priviledge of traveling together with the two of them to the holiday home of their sons in Masuria. There the whole family met and spent their holidays – bicycle tours, extended walks, swimming, Polish cucumbers brought in by a neighbor ... Other journeys led Krzys to a favored place, Italy. He loved this country, and its inhabitant, and knew nearly every corner. In 2010 Krzys offered a course “Solid Mechanics“ at the ROSE School in Pavia. I accompanied him to provide the classroom exercises. |

We were completely gratified that Carlo Lai provided us with two orange bicycles for use during our stay in Pavia, which provided transportation to work and also for enjoyable tours of the region. It was a very pleasant time!

My favorable impressions go back to the first time I met Krzysztof in Essen in 1992. He was always receptive to both scientific and personal matters, and it is my personal desire to honor Krzysztof once again, following the 1st CMwM in 2010 on the occasion of his 70th birthday, which we were fortunate to celebrate with him. This second international conference on the occasion of his 75th birthday offers friends and colleagues the opportunity to participate in commemorating a great scientist and most amiable human being.

2nd CMwM2015, 2-5 May 2015, Łagόw, Poland, in memory of Krzysztof Wilmanski

http://www.cmwm.put.poznan.pl/

by Olivier Maisonneuve (Montpellier)

Jean Jacques Moreau passed away in Montpellier at the age of 90, in the night between the 7 and 8 January 2014. During the last three years, although he was needing important medical care and having many difficulties to move, he was always friendly for his visitors, with his well-known and attentive courtesy.

He was born on 31 July 1923 in Blaye (Gironde). "Agrégé in Mathematics and Doctor of Mathematics (University of Paris), he began his career as a researcher at Centre National de la Recherche Scientifique (CNRS) before being appointed as Professor of Mathematical Methods in Physics at Poitiers University, and then Professor of General Mechanics at Montpellier University II, where he spent most of his career. Here he created the renown Groupe dAnalyse Convexe. During the three years preceding his retirement, the Equipe dAnalyse Appliquée et Mécanique evolved, under his responsibility, to become the Laboratoire de Mécanique Générale et des Milieux Continus (LMGMC), joint research unit at Montpellier University II-CNRS, with effect from 1986. This one, after having absorbed the Laboratoire de Génie Civil, became in 1991 the Laboratoire de Mécanique et Génie Civil (LMGC), itself joint research unit at Montpellier University II-CNRS. Within LMGC, Jean Jacques Moreau then continued his works very actively as Emeritus Professor till 2010.

Luminous and bright, his teaching has left an imperishable memory to his students.

The central theme of his researchs is nonsmooth mechanics, a field whose applications concern for example contacts between rigid or deformable bodies, friction, plastic deformation of materials, wakes in fluid flows and cavitation. The helicity invariant in the dynamics of ideal fluids, discovered by Jean Jacques Moreau in 1962, provided a starting point for the consideration of certain problems arising in fluid dynamics. His mathematical knowledge and creativity equipped him to develop theoretical tools adapted to these subjects, and these became standard practice in nonsmooth mechanics. This activity led him to important contributions in the construction of nonsmooth analysis, a mathematical field that is likewise of interest to specialists in optimisation, operational research and economics. He thus founded the Groupe dAnalyse Convexe in the 1970s, at the Institut de Mathématiques at Montpellier University II, which continued, under a succession of titles, to produce outstanding contributions.

Since the end of the 1980s, Jean Jacques Moreau focused more closely on the numerical aspects of the subjects he was studying. He notably devised novel calculation techniques for the statics or dynamics of collections of several bodies. Direct applications concerned, on one hand, the dynamics of masonry works subjected to seismic effects and, on the other, the largely interdisciplinary field of the mechanics of granular media. His innovating and outstanding computer simulations allowed him to make substantial personal contributions to this branch of mechanics, while his numerical techniques found applications in seismic engineering and rail engineering (LGV, lignes à grandes vitesses, ballast behaviour).

Jean Jacques Moreau was awarded a number of prizes by the Académie des Sciences of Paris, including the Grand Prix Joanidès. He spent a year as guest researcher at Mathematical Research Centre at Montreal University, and was invited abroad on numerous occasions by the top research teams in his field. He was author, co-author and editor of several advanced works on contact mechanics and more generally, on nonsmooth mechanics and analysis. All are pertinent, original and very elegant. His course in 1966-1967 at Collège de France on Convex Functionals is still a reference. He also published a two-volume course in mechanics that greatly influenced the teaching of this discipline.

For numerous academics Jean Jacques Moreau has been and truly will remain for a long time a "Master in Mathematics and Mechanics.

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The ISIMM Prize was launched at the 2008 STAMM Meeting. On that occasion it was decided that the award will be given once in two years at the regular STAMM conferences.

The recipient of the prize is expected to have made exceptional contributions towards building a link between Mathematics and Mechanics.

Candidates are proposed by ordinary ISIMM members, but need not be members themselves. The selection is operated by the Executive Committee, via a ballot.

The selection was performed last October. The result was that the winner of the ISIMM Prize 2014 is

Prof. Dr. Constantine M. Dafermos from Brown University.

The prize will be awarded in a special session chaired by professor Ingo Müller, former recipient of the ISIMM prize, at the STAMM conference in Poitiers, Sept. 8-11, 2014.

Previous Awardees:

ISIMM Prize 2010 was awarded to Jerald LaVerne Ericksen,

ISIMM Prize 2012 was awarded to Ingo Müller.

Thanks to the funds provided by the organizers of the 2014 STAMM, last year the ISIMM officers proposed to launch a Junior ISIMM Prize. The recipient of the prize was selected among the researchers who made significative contributions linking Mathematics and Mathematical Physics, and had been born after January 1, 1976.

Candidates were proposed by ordinary ISIMM members, but needed not be members themselves. The selection was operated by the Executive Committee, via a ballot.

The outcome was a tie, and on this basis the Executive Committee decided to co-award the ISIMM Junior Prize 2014 ex-aequo to the candidates that had obtained the most of votes, that is,

Prof. Dr. Elisabetta Rocca and Dr. Stefan Neukamm

both currently at the Weierstrass Institute for applied analysis and stochastics (WIAS) in Berlin. This prize will also be awarded in a special session chaired by Professor Ingo Müller, at the STAMM conference in Poitiers, Sept. 8-11, 2014.

Augusto Visintin (president of ISIMM)

by Michela Eleuteri (Firenze)

On May 13-15, 2013 the 9th International Symposium on Hysteresis Modeling and Micromagnetics HMM 2013 was held in the wonderful scenario of Taormina (Italy). HMM 2013 was intended to be a forum of presentation and discussion of the most recent advancements in the fields of hysteresis modeling, micromagnetics and in the experimental fields where this kind of modeling is required. According to the tradition that originally inspired the previous symposia, more than 100 participants (from almost all areas of Europe and some from USA, Canada, South Corea, Japan and China) with various backgrounds (physicists, mathematicians, engineering, material scientists?) met to exchange ideas, methods and results. The scientific program of the 3-day symposium included 4 key-note talks, 23 invited talks, 50 contributed talks, 60 contributed posters.

Although special emphasis has always been put on magnetic hysteresis, these symposia always included sessions focused on universal aspects of hysteresis, independently of its origin. However, regrettable enough, this was not the case for this appointment, since the number of sessions dedicated to micromagnetics doubled the sessions dedicated to hysteresis. In particular very few mathematicians were present, and only a restricted number of talks or poster were dedicated to hysteresis modeling.

In order to let people be aware of the recent advances in hysteresis phenomena, and with the intention to attract students, a new project was created: on May 27-31, 2013 in Milano (Italy) took place the first Spring School on Rate-independent evolutions and hysteresis modeling "hystri2013".

The idea of a school was somehow new; in particular it had the aim of connecting hysteresis processes and rate-independent phenomena along an interdisciplinary setting. This because interest into these issues is shared by researchers with different backgrounds. Those processes are actually encountered in many situation of common life: for instance in physics we find them in elastoplasticity, ferromagnetism, shape memory alloys, phase transitions. They also occur in engineering, biology, economy and many other settings.

The nodal point is the fact that the complexity that characterizes phenomena of this kind necessarily requires a joint contribution of experts with different skills. Only a good synergy and cooperation may thus lead to substantial advancements.

The aim of the school was to present some recent research directions with the clearest possible language, to attract non-experts in the field (in particular students), and to make them aware of the relevance of this issue.

The program consisted in minicourses, invited lectures and some contributed talks; an important novelty was the round table entitled: ?Hysteresis for applications and industry: which perspectives??, where also representatives of international companies discussed how research and industry may cooperate particularly in the Italian framework.

The next appointments with hysteresis will be:

- April 7-11, 2014: MURPHYS-HSFS 2014, WIAS (Berlin, Germany)
- 2015, 10th International Symposium on Hysteresis Modeling and Micromagnetics, HMM 2015 - Iasi (Romania).

Contact: Michela.Eleuteri [at] unimi.it - Web page: http://www.mat.unimi.it/users/eleuteri/

by Augusto Visintin (Trento)

Michela keeps on exhibiting great enthusiasm, and also a certain dynamism in organization. Her contribution to this forum also deserves some appreciation. (Encouragements apparently are not really needed...)

The Taormina meeting was the last of the HMM series, that saw the participation of engineers, physicists and mathematicians. As Michela pointed out, this conference marked a deviation from the original spirit.

The high-fee and no-refunding policy, and the reduced concern for fundamental issues induced most of the senior mathematicians (including myself), some physicists and also several engineers to renounce to this appointment.

Unfortunately, it is not evident that the next HMM might see a return to the previous line. Mathematical-physicists, mathematical analysts, physicists and engineers with some interest into hysteresis modeling might search for other opportunities for exchanging their views. The meeting at WIAS in Berlin in April 2014 goes into this direction.

Contact: visintin [at] science.unitn.it - Web page: www.science.unitn.it/~visintin/