This article is focused on the surface assessment of some ground glasses grinded by means different sorts of abrasion dust. It determines amplitude roughness parameters of ground glass samples and related PSD functions. Measurements were done by means of mechanical inductive profilometer Form Talysurf Series 2 - both software and hardware gear for solid surface assessment of shape, waviness and roughness with extraordinary resolution. and Článek je zaměřen na zhodnocení stavu povrchu několika matnic vybroušených různými brusivy stanovením amplitudových parametrů drsnosti a PSD funkcí. Měření probíhala na přístroji Form Talysurf Series 2. Jedná se o indukční mechanický profilometr - hardwarový i softwarový nástroj pro detekci parametrů tvaru, vlnitosti a drsnosti povrchů pevných těles s mimořádnou rozlišovací schopností.
An analytical formula for the time transformation TDB-TDT valid over a few thousand years around J2000 has been computed with an accuracy at the 1 ns level. This computation was carried out by integrating the differential equation derived from a general metric.
The transformation TDB-TDT is independent of the PPN parameters, γ and β, and of the 3 most commonly-used coordinate systems (standard, isotropic, Painlevé), at least at the 1 ns level.
The analytical theories ELP2000 and VSOP82 developped at the Bureau des Longitudes were used for the motions pf the solar systém bodies, Furthermore, the numerical procedures described by Hellings and Davis to calculate this transformation yield different results to our own procedure. These differences are due to the long-period terms of the planetary theories which are averaged out
in the numerical procedures. These terms are generated by resonances in the Solar System.
On the example of Ostrów Tumski in Wrocław (Silesia, Polish lands) an attempt of identification of places associated with trade and exchange in early medieval strongholds was made. The alleged marketplace existed in the stronghold from the end of the 11th century to the end of the 12th century. Its existence would be confirmed by the empty square between buildings, the accumulation of finds related to trade and exchange as well as spending free time. The connection of some buildings form Ostrów Tumski with commercial activities is also not excluded. On the basis of analogies from the main centers of the Piast state and selected sites from the Bohemian and Moravian territories, the potential location of the marketplaces was analyzed. Attention was drawn to the relationship between finds related to trade and exchange with other manifestations of economic activity (e.g. non-ferrous metallurgy). An attempt was also made to answer the question when and in what political and economic conditions such places could be created.