On the first evidence of gum guaicum and its use as finishing pigment on Brasilian ceramics

This study reports a multi-analytical investigation on two ceramic bowls from the 19th-century Brazilian production, belonging to the Kadiweu culture (Rio Nabileque, Mato Grosso do Sul) and currently preserved at MUCIV (Museo della Cività, “Museo Etnografico L. Pigorini” section) in Rome [1]. X-ray radiography was used to define the execution technique. Optical microscopy on thin section and X-ray diffraction (XRD) were used to characterize the ceramic production in terms of raw materials, firing and production process. UV observation and micro-Fourier Transform Infrared spectroscopy (µ-FTIR) were used to highlight the presence of restoration or protective products. Results showed that raw materials and technology are compatible with the local production [2]. The use of grog was documented for the ceramic paste, which was in part shaped by the coiling technique and then fired at moderately high temperatures and decorated with a white calcic pigment. The most striking finding was the identification of the so-called gum guaicum – or guaiac resin -, most likely used as a black pigment [3] during the last production steps, its spectrum being for the first time collected on ceramics. The use of a resin from “pau-santo” (Brazilian Blackheart or holy wood) as a pigment for blackish areas has been documented on the corresponding contemporary production, where it is extracted and eventually mixed with mastic for darker hues

Tradition unveiled. Pottery production in the Brazilian Kadiweu culture

The ceramic bowls production of the Brazilian Kadiweu culture (Rio Nabileque, Mato Grosso do Sul), currently belonging to Museo delle Civiltà (MUCIV) – Museo Nazionale Preistorico ed Etnografico “Luigi Pigorini” in Rome, were studied for the first time by a multi-analytical investigation at Istituto Centrale per il Restauro (ICR, Rome). Optical microscopy on thin section (OM) and X-ray Powder Diffraction (XRPD) were used to characterize two Kadiweu bowls (raw materials, firing and production process). UV observation and micro-Fourier Transform Infrared Spectroscopy (µ-FTIR) were used to characterize either original or former restoration products. Finally, X-ray images were taken to study the modelling technique. This minimally invasive approach showed that raw materials and technology are compatible with local production. The use of grog was documented for the paste, which was then fired at moderately high temperatures. This study also led to revise some ethnographic data on decorations, at least for the analysed bowls, such as the use of kaolin as white pigment, which was instead proven to be calcite, or the origin of the traditional black dye from pau santo, a local tree. Its spectrum was for the first time collected on ceramics and identified as guaiac resin, which possibly comes from Guaiacum sanctum or officinale. This research project also allowed the identification of two different restoration activities, with two types of adhesives: shellac and animal glue, the latter used with lithopone. Paraloid B72 was also identified as a protective layer. Finally, textile materials found on the artefact were also characterized

Searching for galaxy clusters in the VST-KIDS survey

We present the methods and first results of the search for galaxy clusters in the Kilo Degree Survey (KiDS). The adopted algorithm and the criterium for selecting the member galaxies are illustrated. Here we report the preliminary results obtained over a small area (7 deg2), and the comparison of our cluster candidates with those found in the c and SZ Planck catalogues; the analysis to a larger area (148 deg2) is currently in progress. By the KiDS cluster search, we expect to increase the completeness of the clusters catalogue to z = 0.6–0.7 compared to RedMapper. © Springer International Publishing Switzerland 2016

Search for Scalar Diphoton Resonances in the Mass Range 65−60065-600 GeV with the ATLAS Detector in pppp Collision Data at s\sqrt{s} = 8 TeVTeV

A search for scalar particles decaying via narrow resonances into two photons in the mass range 65–600 GeV is performed using $20.3\text{}\text{}{\mathrm{fb}}^{-1}$ of $\sqrt{s}=8\text{}\text{}\mathrm{TeV}$ $pp$ collision data collected with the ATLAS detector at the Large Hadron Collider. The recently discovered Higgs boson is treated as a background. No significant evidence for an additional signal is observed. The results are presented as limits at the 95% confidence level on the production cross section of a scalar boson times branching ratio into two photons, in a fiducial volume where the reconstruction efficiency is approximately independent of the event topology. The upper limits set extend over a considerably wider mass range than previous searches