Equilibrium crystal shapes in the Potts model

The three-dimensional $q$-state Potts model, forced into coexistence by fixing the density of one state, is studied for $q=2$, 3, 4, and 6. As a function of temperature and number of states, we studied the resulting equilibrium droplet shapes. A theoretical discussion is given of the interface properties at large values of $q$. We found a roughening transition for each of the numbers of states we studied, at temperatures that decrease with increasing $q$, but increase when measured as a fraction of the melting temperature. We also found equilibrium shapes closely approaching a sphere near the melting point, even though the three-dimensional Potts model with three or more states does not have a phase transition with a diverging length scale at the melting point.Comment: 6 pages, 3 figures, submitted to PR

Structure and morphology of hydroxylated nickel oxide (111) surfaces

We report an experimental and theoretical analysis of the sqrt(3)x sqrt(3)-R30 and 2x2 reconstructions on the NiO (111) surface combining transmission electron microscopy, x-ray photoelectron spectroscopy, and reasonably accurate density functional calculations using the meta-GGA hybrid functional TPSSh. While the main focus here is on the surface structure, we also observe an unusual step morphology with terraces containing only even numbers of unit cells during annealing of the surfaces. The experimental data clearly shows that the surfaces contain significant coverage of hydroxyl terminations, and the surface structures are essentially the same as those reported on the MgO (111) surface implying an identical kinetically-limited water-driven structural transition pathway. The octapole structure can therefore be all but ruled out for single crystals of NiO annealed in or transported through humid air. . The theoretical analysis indicates, as expected, that simple density functional theory methods for such strongly-correlated oxide surfaces are marginal, while better consideration of the metal d-electrons has a large effect although, it is still not perfect.Comment: Replaces previous submission with smaller PDF file size. 32 pages including 9 figures and 2 table

THE NYDAM BOAT AT KIEL

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SHIPS EARLIER THAN 1500 A.D.

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NOTES

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Die deutsche Reichsflotte. 1848-1852.

Mode of access: Internet

Ryhiner-Kartensammlung / 21 Episcopatus Hildesiensis nec non vicinorum statuum delineatio geographica

per Gerhard Iust. Arenholdum hildesiensem iur. et math. stud. ; opera hæred. Ioh. Baptist Homanni S.C.M. geographiStadtplan unten links ("Ichnographia Hildesiæ", 8 x 11 cm), Stadtansicht unten Mitte ("Scenographia urbis Hildesiæ ab occidente", 6 x 20 cm)Titelkartusche und Massstabsleisten unten rechts, Legende oben recht