Two sites of the Neandertal-associated Middle Paleolithic of Iberia, dated to as early as approximately 50,000 years ago, yielded perforated and pigment-stained marine shells. At Cueva de los Aviones, three umbo-perforated valves of Acanthocardia and Glycymeris were found alongside lumps of yellow and red colorants, and residues preserved inside a Spondylus shell consist of a red lepidocrocite base mixed with ground, dark red-to-black fragments of hematite and pyrite. A perforated Pecten shell, painted on its external, white side with an orange mix of goethite and hematite, was abandoned after breakage at Cueva Antón, 60 km inland. Comparable early modern human-associated material from Africa and the Near East is widely accepted as evidence for body ornamentation, implying behavioral modernity. The Iberian finds show that European Neandertals were no different from coeval Africans in this regard, countering genetic/cognitive explanations for the emergence of symbolism and strengthening demographic/social ones.

We report on the growth of AlxGa1-xN nanowires by plasma-assisted molecular beam epitaxy for x in the 0.3-0.8 range. Based on a combination of macro- and micro-photoluminescence, Raman spectroscopy, x-ray diffraction and scanning electron microscopy experiments, it is shown that the structural and optical properties of AlGaN NWs are governed by the presence of compositional fluctuations associated with strongly localized electronic states. A growth model is proposed, which suggests that, depending on growth temperature and metal adatom density, macroscopic composition fluctuations are mostly of kinetic origin and are directly related to the nucleation of the AlGaN nanowire section on top of the GaN nanowire base which is used as a substrate.

Pillared derivatives of γ-zirconium phosphate, having the general formula ZrPO4[O2P(OH)2]1 - x [O2POH−(CH2) n −HOPO2] x /2·mH2O (n = 4, 6, 8, 10, 12, and 16), were prepared by soft topotactic reactions between colloidal dispersions of exfoliated lamellae of γ−ZrPO4[O2P(OH)2]·2H2O and 1,n-alkanediphosphonic acid solutions. In these compounds the interlayer distance can be easily modulated almost continuously by increasing the number of the carbon atoms in the alkyl chain, while the lateral distance of the pillars can be varied over a large interval according to the degree of pillaring. The interlayer distance of compounds with a low percentage of pillaring decreased appreciably when the intercalated solvent was eliminated (e.g., by dehydration). The reversible elongation and shortening property of the interlayer suggests that the alkyl chains, being nonrigid pillars, tend to fill up empty spaces created by the loss of interpillar solvent by adopting different conformations in the interlayer region. The large interpillar spaces filled by solvent can be seen as “tailor-made molecular vessels,” in which specific reactions could be carried out in a restricted environment.

No abstract

M = 1208.0, yellow. triclinic PI. 7 = 95.47(2) . I,'= 2361.5 A3. 2 =2. pL,s,cd = 1.699. p (Cu,,) = 33.755 cm-'. 4921 reflections (3 < 0 < 51 . k h + k + I ) Mere collected at -100 C on a crystal of 0.26 x 0.20 x 0.09 mm. empirical absorption correction were applied.

A grisaille is a brown-blackish paint applied onto the inner surface of stained glass to draw the contours and details of the figures and to produce the effect of shades and volumes. Grisailles were traditionally made of finely ground oxides of iron *Trinitat.Pradell@upc.edu but also of copper, zinc, lead, or manganese mixed with a flux such as lead ground glass and a binder and fixed onto the flat glass by firing. The grisailles have typical layer thickness varying between 10 and 100 lm and are formed by a complex mixture of pigment particles, crystalline, and amorphous reaction compounds, aging, and weathering compounds. The high brilliance, collimation, energy selection, and monochromacity of the SR beam are ideal to obtain micro-XRD patterns from thin cross sections of the grisailles. The analyses are complemented with SEM-EDX and LA-ICPMS. A selection of grisailles from several cathedrals and buildings in Spain, Avila, Burgos, Alcal a de Henares, and in particular from Segovia, dating from early 16th to the 20th century and belonging to several master glaziers are studied. Changes in the methods of production and materials in the different historical periods are obtained and also related to the conservation state of the materials. 42

The results of the analyses of elemental composition of red and black pigments of Levantine rock art from La Saltadora rock shelters (Valltorta gorge, Castellón, Spain) are presented in this paper. Nondestructive analyses were carried out using a portable energy dispersive X-ray fluorescence (EDXRF) spectrometer developed for in situ analysis. The results revealed the strong presence of calcium in all the analyzed locations due to the contribution of the underlying calcareous bedrock and the overlying crust. Iron is the main element detected in red pigments and manganese in black pigments. Iron and calcium ratios have been found indicative of the degree of preservation of the pictorial layer. Trace elements detected in the pigment composition confirm the use of different raw materials. Therefore, this work illustrates the potential of the portable EDXRF spectrometers for in situ analysis of rock art paintings.

a b s t r a c tSpanish Levantine Rock Art is a unique pictorial expression within the prehistoric European context. Located in shelters in the inland regions of the Iberian Mediterranean basin, this art form, which must be necessarily studied in the frame of the process of neolithization of this territory, still lacks direct dating, and therefore its authorship is still open to debate.In this paper we present the first characterization of black pigments used in the Cova Remigia shelters in the Valltorta-Gassulla area (Castell on, Spain) by means of EDXRF spectrometry combined with SEM-EDS and Raman spectroscopy. Our aim is both to identify the raw material used for the preparation of black pigments and to make a first approach to the cultural choices involved in its use.The results are relevant for several reasons. Firstly, carbon-based black pigments have been identified for the first time in northern regions of Levantine rock art. Secondly, the recurrent use of black pigments in Cova Remigia questions the assumption of its restricted use in Spanish Levantine art. Thirdly, posterior repainting and graphic re-appropriation of black figures have been observed in Cova Remigia, giving rise to the combination of two colours, black and red, fact that is extremely rare in this rock art tradition. Finally, the identification of organic matter in the black pigments opens the possibility of radiocarbon dating.