Sunday, May 13, 2007


I just returned from State College-PA, where the CALPHAD XXXVI took place. As always it was a pleasant meeting, where not only the challenges and discoveries of computational thermodynamics where discussed, but also where friends could meet again. I will present here some of the highlights of the meeting , both scientific and social.

I was impressed by the large amount of presentations concerning the convenience or inconvenience of changing the description of pure elements, with the introduction of some physically based equation of state to handle the pressure/volume state variables. As mentioned by Larry Kaufman, these changes would require major changes in the thermodynamic descriptions of all systems, which surely is a huge task. In my opinion this is true, but someone will eventually start doing this. I believe that the actual descriptions will coexist with new, improved, physically-based models, until these acquire the same coverage of described systems and the same level of confidence of the existing models.

Another highlight of the last meeting was the elevated number of presentations dedicated to the use of the existing models and thermodynamic databases to modeling derivate thermodynamic properties, which are not usually experimentally determined, like viscosity of molten slags (Nicholas Grundy, using FactSage), surface tension (Risto Pajarre) and solder wettability (Zbigniew Moser).

As always Prof. John Morral´s presentation was a show! The "lecture" dealt with teaching phase diagram topology to undergraduate students. The techniques described have high learning potential for this arid topic (at least to our students).

The most impressive presentation was due to Prof. Dr. Byeong-Jo Lee, of the Pohang University in South Korea. He showed how standard thermodynamics, incorporation capillarity effects through tyhe Gibbs-Thompson equation was able to justify size-effects observed in nanotechnology. He exemplified considering two cases: the size-dependency of melting point in platinum nanoclusters and nanowires and the size-dependent composition of Si-Ge nanowires. His results clearly show that the usual thermodynamic tools are valid up to a quite small scale, which would not be accepted by most physicist as possible.

In the social side we had a pleasant meeting, as always. Most of the participants know each other from previous CALPHADs and the new participants are well received in general, so they quickly become part of the family. One anonymous (so nobody will be hurt due to the authorship, literally) quotation, which all participants agreed, clearly defines the CALPHAD meeting was "It was so much alcohol!" (referring to something that happened in last year´s CALPHAD, in Israel). Could not be perfectly realized in the present meeting due to the unusual closing time of the hotel bars (9 pm) and the long distance to the town, but even so we had our liquid amount available :-).

The conference excursion was to the Gettysburg battlefield. We were blessed with a sunny day as can be inferred from these photos. It was an unusual excursion, I had never visited a battlefield before. And sometimes it was a little bit awkward to walk literally over the grave of so many dead people. Our competent and passionate guide helped us to overcome this strange feeling and allowed to us, foreigners, to have some insight on the way that the Americans handle these historical events.

The banquett was very nice. The following photos show our table. As you can see, the motto was, "there is always one place more" ;-).

Finally, one has to mention our trip to the Mad Mex bar in State College. Of course, only some of us still had some energy after five days of drinking (err..., I mean, of congress), but nevertheless, it was fun. My congratulations to the "Stone Arrogant Bastard Ale", which could be easily renamed "Stone Arrogant Bastard Bitter Ale". I finish this report with some of the pictures of that night.