Welcome, dear reader and welcome, dear participant of Diffusion Fundamentals II. It is with great pleasure that we offer you the second conference boo

Transcription

1 Welcome, dear reader and welcome, dear participant of Diffusion Fundamentals II. It is with great pleasure that we offer you the second conference book appearing in a series dedicated to aspects of diffusion experiment, theory and application which are of general interest for the large, interdisciplinary community of people, who are active in the diverse areas of industry and academia related to diffusion phenomena. Diffusion Fundamentals I in 2005 gave us the opportunity to celebrate the international year of physics, commemorating two important dates in the diffusion history, namely 150 years since Fick's and 100 years since Einstein's equations on diffusion. Leipzig, as the location of this conference, could boast of having been the place where these seminal papers have been published. Moreover, the conference was an important event in the preparations for the 600 th anniversary of Leipzig University in 2009, the second oldest university in Germany (after Heidelberg). As a matter of fact, L'Aquila, the location of Diffusion Fundamentals II, close to the Eternal City (Rome), exceeds by far all these landmarks of history. This is demonstrated by the book's first paintings, displaying the Pons Cestius, the modern S. Bartolomeo bridge, over the river Tiber originally built between 62 and 27 B.C. and the "Colosseum", built between 70 and 80 A.D., as two of Rome's most prominent edifices. Insiders, i.e. the participants of Diffusion Fundamentals I and those who have incidentally come across this conference volume, with these paintings, will have recognized a familiar acquaintance. In fact, we are again happy that Taro Ito, our Japanese colleague and friend, has graced this conference book with local paintings, making it - in addition to its scientific value - a nice conference souvenir and a source of information about the city of L'Aquila and its surroundings. Given the true multidisciplinary nature of this conference series it makes perfect sense to try and draw a link with the arts. Since pictures are worth a thousand words, throughout this book Taro Ito's painting will help us to provide a link between the contributions and the venue of this conference, the city of L Aquila. Many of the images are of purely artistic pleasure and we hope that during the conference you will be able to explore L Aquila and to identify in a real random-walk manner the locations that Taro saw as particularly attractive. This would be in fact similar to the process that Taro used, since without any particular guidance he spent a few days enjoying the beautiful views that the city offers to one who takes the time to walk through the narrow streets and alleys. In many instances, Taro has been able to see, through the eyes of an artist, the buildings as they were. L'Aquila, as we see it today, dates from the 13 th century when the city was founded by Frederick II, the Holy Roman Emperor. At the time, several lords of the neighbouring villages came together and decided to form a city on this hill which has a strategic position overlooking the lower valley. It is close to the river Aterno and to a renowned 1

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4 route of commerce which in Roman times was called the Via Salaria (salt road). As a testimony to this origin the central part of the city is divided into several quarters, each with a fountain, a church and a main building. As a formal symbol of this unity, the Fontana delle 99 Cannelle was built, and is supposed to have a fountain-head representing each lord. This fountain has never run dry in over 700 years. The architect who built it was captured during a siege and died without revealing the source of the water. Symbolizing the origin and vitality of L'Aquila, this fountain is shown on Taro Ito's first local painting in this book. Adjacent to it, both in this book and in reality, you may view a combination of walls, steep passages, stairs, houses and a lot of green, as typical ingredients of the city. Another of these impressive doors is Porta Bazzano, which is displayed on page 7 while the picturesque Costa Masciarelli ( coste are steep streets with stone steps) that leads to it is displayed on page 8. The dates of the conference were chosen to coincide with the city s festival of the Perdonanza (full absolution). The origins of this festival date to 1294, when St. Peter of Morrone, a hermit in the mountains near L Aquila, was elected to be Pope and took his solemn vows in the Basilica of Collemaggio (page 85) on the 29 th of August. At this time corruption in Rome was rampant and a respected figure-head was needed. Pope Celestino V (his chosen name) did not endure this for more than 3 months. He decided to give up his post and returned to his mountains to be closer to God. He was the only Pope to resign in the history of the Catholic Church. Both Celestino V and Frederick II, who was excommunicated because of his frequent disputes with the Papal state over land, are placed by Dante in the Inferno. Excluding the possibility that the conference participants may follow them to this place, it is worthwhile to mention that disputes (which happen to be disliked by potentates in policy and science not only in ancient times) are among the main driving forces for a better understanding of our world and a peaceful productive cooperation. Is this not a strong motivation to organize a scientific conference at this place? In September 1294, Celestino V made an edict that marks a special event for pilgrims who visit the Basilica of S. Maria of Collemaggio between the sunsets of the 28 th and 29 th of August. To mark this, a procession with the Papal edict is taken to the Basilica and the Holy Door opened for 24 hours. This is what normally happens only on the Jubilee year (every 25 years) in Rome. For Catholics worldwide this is an important event since it allows, through a path of true repentance, prayer and confession, to have all sins absolved; hence the name Perdonanza. Whether Celestino V thought that the people of L Aquila were in need of absolution or if this may have been a suggestion to those in Rome, we do not know. He later died as a hermit and his preserved body can be found in the Basilica dressed in his papal robes. 4

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9 As a modern festival the Perdonanza retains its spiritual roots. Those who are interested can participate in the vigil in the Basilica. It is accompanied by a series of cultural events throughout the city. There is no question that the organizers of this conference do not imply that the real reason for your participation is the option of "Perdonanza" and forgiveness of sins. However, the problems St. Peter of Morrone had with the clergy of his time, namely blatant negligence of obligations, should remind us that, in a preface to a volume edited in relation to a scientific conference, it is time to concentrate again on the key issue of this volume, the fundamentals of diffusion and their reflection by experiment, theory and application. The diffusion community and, in particular, the organizers of Diffusion Fundamentals II are pleased again to have the support of renowned scientists working in many diverse diffusion - related fields. Today, a conference consisting exclusively of plenary and poster sessions is exceptional - and we beg your pardon if we failed to include those speakers and topics which you consider to be most essential. The poster sessions and our tradition that plenary speakers and chairmen do their best to refer to the posters related to their sessions will hopefully help to compensate for possible deficiencies. Moreover, the host of Diffusion Fundamentals III in Athens 2009, Doros Theodorou, will be happy to receive your recommendations for contributions to the next conference in this series. With this book, we are going to follow also a second line of tradition that commenced during Diffusion Fundamentals I: The contents of the conference book are divided into different chapters which present, in addition to full papers and poster abstracts, some views on the conference venue and its surroundings, complemented with local details which - either directly or via some back door - are related to the chapter's topic. Depending on the authors' available time, the full papers span the whole spectrum from articles describing a specific research project, i.e. typical contributions to conference proceedings, up to informative overviews of diffusion-related research areas for a very broad audience. As a motivation, Johann Wolfgang von Goethe, one of the great figures addressed in Diffusion Fundamentals I, in general and with his drama "Faust" in particular, would have said: providing some variety will leave nobody with nothing ("Wer vieles bringt, wird manchem etwas bringen"). This time, the great historical figures behind the scene are Frederick II and St. Peter of Morrone who, over the short period of three months, left his hermitage in the woods close to L'Aquila to serve as pope Celestino V in the nearby city of Rome. We are happy that in this conference book you may even make contact with one of the most celebrated scholars of the Middle Ages, Thomas Aquinas. Some of Taro Ito's paintings provide a nice impression of the ambience in which he lived. In the last contribution to the book you have the chance to follow his reasoning (or, more correctly, what his reasoning most likely would have been) to solve a little puzzle of electrodynamics, which became a part of mankind's wisdom only 500 years after his time. 9

10 The venue of this conference is a 15 th century Spanish fortress which is shown on page 11. It was built as a result of a revolt of the people of L Aquila against the King of Naples. He regained control of the city after a long siege led by Braccio da Montone, also known as Fortebraccio, who died as a result of his injuries a few days after the final battle. The Spanish imposed heavy taxes in order to build the Castle. This Castle was meant as a symbol of power, hence the majestic proportions, but was never actually the scene of a battle. Now it houses the Museum of Abruzzo and it also has a scientific use since sensors are present in the dungeons to continuously monitor any seismic activity. We are sure that in August 2007 it will serve as a dignified place demonstrating the power of diffusion research and ensuring exchange and multiplication of our knowledge in the field. It is good to know that, after hot conference discussions and/or extensive use of the options of "Perdonanza", the way to the hotels and to rest after a hard day is quite short as, e.g. to the Hotel Duca degli Abruzzi which probably hosts most of the conference participants and which is shown on the final painting of this welcome address. Before concluding, we want to thank you all once again for coming to L'Aquila or - if you happen to look into this book without having been among the conference participants - for your interest in this edition. We are particularly obliged to all colleagues who have contributed to this volume and thus have made it an attractive compilation of the problems and results of current diffusion-related research. Once again, we thank Douglas M. Ruthven for a last linguistic check of our accompanying texts. We express our gratitude to numerous sponsors who are listed on the inner cover pages, as well as to the Leipziger Universitätsverlag and Dr. Gerald Diesener for again providing us with the option of a last-minutes publication of the conference book in which we succeeded in including very late, and correspondingly up to date submissions, with the last paper being submitted only six weeks before the beginning of the conference. This last item is mentioned to thank those many contributors who were on time with their submissions and the publishers and printers for their efficient work, rather than to stimulate the repetition of the negative examples. Last but not least, we acknowledge the great work by Tomas Binder who again most successfully handled the myriads of contributions, often submitted in many different formats. In close contact with the authors, and with editing support by Lars Heinke, Florian Hibbe and Konstantin Ulrich, he managed to create a uniform electronic version for the printer. Within a (diffusion) family it is probably also appropriate to mention that, after having completed the technical work with the book, Tomas - like two years before with Diffusion Fundamentals I - has to return to the preparation for his examinations. We hope you do not mind us including our best wishes for his success together with our wishes for the success of Diffusion Fundamentals II and of this book summarizing the scientific outcome of this conference and providing also some information about the city of L'Aquila, its venue. 10

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