Microchemical Investigation of Archaeological Copper Based Artefacts Disclosing an Ancient Witness of the Transition from the Value of the Substance to the Value of the Appearance

In many Italian archaeological sites dated between the sixth and third centuries BC, unworked lumps of Cu-based materials are sometimes found, the so called Aes Rude, which according to archaeological considerations were appreciated as currency, as a medium of exchange and as a form of saving. The microchemical investigation of these ancient artefacts discloses their nature as apparently not usable for any functional applications or possible use. Indeed, Aes Rude resemble ordinary copper material, but microchemical results indicate that they are constituted by highly ferruginous leaded copper, making them useless for producing other metal objects by means of casting or hot and cold working. Notwithstanding this intrinsic negative feature, the production of these intractable Cu-based alloys was deliberately carried out to maximise the process yield in terms of produced metal from an impure and unselected metal ore by tailoring the smelting process parameters. With these considerations in mind, the microchemical investigation of these ancient iron–copper alloys gives evidence of the passage from the acceptance of an artefact value based on its true nature or potential use to the acceptance of the value based only on its appearance or form irrespective of its present or future use. This information could contribute to a better understanding of the evolution of human thought and economic and social interactions.     

Aλδ-calculus with an algorithmicδ

In this paper we propose a system, based on-calculus, where the restriction of Church's to normal forms is dropped, while the monotony properties are weakened. The main feature of such a system is that the Church-Rosser property is maintained and all provable equalities between closed terms are semidecidable within it.     

Allylbutyltin halides (CH2CHCH2)SnBu3−nCln (n = 0, 1, 2, 3). Preparation,carbon-13 NMR characterization and allylstannylation ability towards ketones and aldehydes

Mixed allylbutyltin halides (CH₂CHCH₂)SnBu_3-nCl_n (n = 0–3) have been prepared, and characterized by carbon-13 NMR spectroscopy. Their ability to bring about allylstannylation of ketones and aldehydes, to form organostannoxy compounds, Bu_3-nSnCl_nOC(R′)(R″)CH₂CHCH₂, has been shown to increase on increasing the value of n, that is on increasing the acceptor ability of the tin centre.     

Microchemical and microstructural characterisation of medieval and post-medieval ceramic glaze coatings

A large number of ceramic samples (from the 10th to the 19th century), found during the excavation of Sicilian archaeological sites (Syracuse, Caltagirone, Sciacca and Piazza Armerina), have been studied by combining scanning electron microscopy, energy-dispersive X-ray spectrometry and optical microscopy. Attention has been focused on the microchemical and microstructural properties of the painted surfaces to investigate the nature of the enamels and pigments in the decorative layers. The general perspective has been the identification of consistent archeometric criteria, other than the standard stylistic considerations, which can be used for a reliable recognition of the production sites. The results collected for each ceramic typology were used to cluster the different ceramic reference groups in a wide database suitable for a reliable discrimination of the provenance of artefacts. Moreover, the same compositional and microstructural data allow the identification of the raw materials used for pigments. There is evidence of some differences with existing information found in the literature concerning the formulas used in ancient times. Finally, attention has also been devoted to identify the technological aspects of the manufacturing techniques and firing conditions adopted for each typology of glaze coating depending on different ceramic materials .PACS 81.05.Je; 82.80.-d; 68.37.Hk; 68.55.-a     

Crystal structure of tris(2-pyridylthio-2-pyridinium)pentaisothiocyanato-dioxouranate(VI)

Summary The crystal structure of [DPSH] ₃ ⁺ [UO₂[NCS)₅]^3– (DPSH = 2 pyridylthio-2-pyridinium) has been determined by standard methods using diffractometer data. Crystals are monoclinic, space groupP2₁/a, witha=33.16 (3),b=16.68(2),c=7.85(1) Å, and=97.3(1); D_c=1.65 g · cm^–3 for Z=4. The structure has been refined to R=5.8% by least squares methods. Five thiocyanate groups are equatorially bonded to the linear uranyl group. The mean of the five U-N, N-C, and C-S bond distances are 2.45, 1.17, and 1.59 Å respectively. The protonated DPS molecules have the N,N-inside conformations.     

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Stochastic Burgers' equation

We consider a Burgers' equation perturbed by white noise. We prove the existence and uniqueness of the global solution as well as the existence of an invariant measure for the corresponding transition semigroup.