Abstract: The use of non-invasive macroscopic imaging techniques is becoming more prevalent in the field of cultural heritage, especially to avoid invasive procedures that damage valuable artworks. For this purpose, an X-ray powder diffraction scanner (MA-XRPD) capable of visualising crystalline compounds in a highly specific manner was recently developed. Many inorganic pigments present in paintings fall into this category of materials. In this study, the 17th century oil painting Girl with a Pearl Earring (c. 1665) by Johannes Vermeer was analysed with a combination of transmission and reflection mode MA-XRPD. By employing this scanner in reflection mode, the relative sensitivity for compounds that are present at the paint surface could be increased, establishing it as a highly relevant technique for investigating the degradation processes that are ongoing at paint surfaces. Many of the original pigments employed by Vermeer could be identified, along with four secondary alteration products: gypsum (CaSO4 center dot 2H(2)O), anglesite (PbSO4), palmierite (K2Pb(SO4)(2)) and weddellite (CaC2O4 center dot 2H(2)O). The formation of gypsum was linked to the presence of chalk in the upper glaze layer while the formation of palmierite and weddellite is driven by the presence of lake pigments (and their substrates). In this manner, MA-XRPD can also be used to pinpoint locations relevant for sampling and synchrotron mu-XRPD analysis, which provides information on the microscopic make-up of the paint. A paint cross-section taken from an area rich in palmierite was analysed with synchrotron mu-XRPD, which confirmed the presence of this secondary compound at the interface of the upper paint layer with the ground layer as well as the presence of anglesite in the ground layer. The capacity of MA-XRPD to identify and chart secondary alteration products in a non-invasive manner has only very recently been demonstrated and makes it a highly relevant technique for the assessment of the chemical condition of works of art.

Abstract: Jackson Pollock's Number 1A, 1948 painting was investigated using in situ scanning macro-x-ray fluorescence mapping (MA-XRF) to help characterize the artist's materials and his creative process. A multivariate curve resolution-alternating least squares (MCR-ALS) approach was used to examine the hyperspectral data and obtain distribution maps and signature spectra for the paints he used. The composition of the paints was elucidated based on the chemical elements identified in the signature spectra and a tentative list of pigments, fillers and other additives is proposed for eleven different paints and for the canvas. The paint distribution maps were used to virtually reconstruct the artist process and document the sequence and manner in which Pollock applied the different paints, using deliberate and specific gestures.

Abstract: Galvanised iron is popular in many applications, particular as a roofing material. However, just like other materials, especially metallic ones, it is prone to degradation by corrosion. In this particular study, the degradation of galvanised roof sheets was investigated at a coastal, urban and rural site in Tanzania, Africa. Samples were exposed to various outdoor environments over a period of 3 years. In addition, some accelerated laboratory investigations were conducted in different simulated air pollution environments in an artificial corrosion chamber constructed for this purpose to supplement the outdoor exposure tests. It was found that the combination of the tropical climate and increasing air pollution due to industrial development in the capital Dar-es-Salaam resulted in substantial atmospheric corrosion of the roof sheets, which eventually leads to failure and the necessity for replacement. The rural site had the lowest degree of atmospheric corrosion as expected. A combination of different corrosion products was identified as a result of the atmospheric corrosion by Raman and EDX analyses. The information gained from this investigation could be utilised to construct more durable structures requiring less frequent replacement and maintenance in future.

Abstract: We developed a protocol for the immobilization of tyrosinase (Tyr) on the composite of polycyclodextrin polymer (CDP) and carbon nanotubes for the detection of an endocrine disruptor, i.e., butylparaben (BP). The formation of the CDP polymer was characterized by UV-Vis spectrophotometry. The conducting film of cross-linked CDP and carbon nanotubes, displays excellent matrix capabilities for Tyr immobilization. The host-guest chemical reaction ability of CD and the ππ stacking interaction assure the bioactivity of Tyr towards butylparaben. The developed biosensor was characterized electrochemically by electrochemical impedance spectroscopy. The enzyme-substrate kinetic parameters such as the apparent Michaelis-Menten constant (K M app) was measured under saturated substrate concentration. The determination of butylparaben was carried out by using square wave voltammetry over the concentration range of 2.1 to 35.4 μM with a detection limit of 0.1 μM. The fabricated biosensor was successfully applied in real-life cosmetic samples with good recovery ranging from 98.5 to 102.8%.

Abstract: Serum bromine levels in psoriatic Danes increased 2- to 3-fold during a 4-week bathing course in the Dead Sea. This increase correlated well with the improvement in their clinical and psychic condition. Serum bromine levels in psoriatic Danes were somewhat lower than those in healthy subjects residing in Denmark, but the difference was not significant. Israelis working in the open air in the Dead Sea area (air bromine 20-fold higher than in Jerusalem) had higher bromine levels than psoriatic or healthy Israelis residing in Jerusalem or healthy Israelis working in air-conditioned rooms in the Dead Sea area (p < 0.05), but those levels were still within the normal range. As our animal experimentation indicates that the skin is a major target organ for 82Br, applied either by bathing or as an aerosol, we conclude that the higher bromine levels noticed in the psoriatic Danes after their 4-week stay at the Dead Sea may be equally due to their contact with the bromine-containing aerosol and the high bromine level of the Dead Sea waters.

Abstract: In this work synchrotron radiation X-ray diffraction technique was successfully applied for the analysis of pigments found in excavation at Carriqueo rock shelter, Neuquen, Argentina. The pigment samples of orange, red, and brown shades were collected from different levels of this archaeological site and compared with a suspected source of provenance (La Oficina creek). X-ray diffraction patterns of several yellowish, reddish, and red pigments showed the presence of haematite, goethite, kaolinite, and quartz. The majority of Carriqueo collected samples belonged to the same group of the suspected source, having haematite and quartz as main crystalline phases. The results indicate that the raw material from La Oficina is the source of most of the pigments found at Carriqueo. The present work helps us to understand the strategy of supplying raw materials by human groups in the North Patagonia region. (C) 2010 International Centre for Diffraction Data. [DOI: 10.1154/1.3478884]

Abstract: In this contribution, we report a fundamental study of the factors that set the contact resistivity between metals and highly doped semiconductors. We investigate the case of n-type doped Si contacted with amorphous TiSi combining first-principles calculations with Non-Equilibrium Green functions transport simulations. The intrinsic contact resistivity is found to saturate at similar to 2x10(-10) Omega.cm(2) with the doping concentration and sets an intrinsic limit to the ultimate contact resistance achievable for n-doped Si vertical bar amorphous-TiSi. This limit arises from the intrinsic properties of the semiconductor and of the metal such as their electron effective masses and Fermi energies. We illustrate that, in this regime, contacting metals with a heavy electron effective mass helps reducing the interface intrinsic contact resistivity.

Abstract: We present a decision-support system that guides heritage guardians in selecting mitigation actions to improve the indoor air quality and thus the preservation conditions of indoor collections in heritage buildings. This contribution shows that it is feasible to build a decision support system dedicated to preventive conservation when the following barriers are overcome: 1) simultaneous measurement of a wide range of environmental parameters in order to detect a larger number of undesired situations; 2) development of an algorithm to perform reproducible indoor air quality assessments; and 3) transformation of the air quality assessment into a graph that can be read intuitively without causing a wide variation of interpretations among stakeholders. An important aspect of the decision support system is that it reduces several sources of uncertainty that hamper reliable indoor air quality assessments. The possibilities of such a system are illustrated with a measurement campaign in a church where a heating system has been installed and used for the first time.

Abstract: An extended set of 18th century glass vessels was analyzed by means of SEM-EDX (major and minor element composition) The fragmented archaeological objects were recovered from a latrine belonging to the early 18th century building phase of the nunnery of Clairefontaine, near Arlon (B). On the basis of typology and decoration, the major part of the vessels could be dated around the middle of the 18th century. Variety in color and weathering of the glass suggest differences in glassmaking recipes and in the composition and origin of raw materials. The results of the analysis show how two main compositional groups constitute about 90% of the analyzed glass set, and these are constituted by potash glass (transparent beakers) and high lime low alkali glass (green bottles). Next to these, a few potash-lime and soda glasses are also found. The type of alteration has also a clear relation with the original glass composition.

Abstract: In this publication optical spectroscopy is considered to be a supplementary technique to study ancient colored glass. It results from a systematic study of the UV-VIS-NIR transmission spectra of intentionally colored glass fragments from various archaeological and historical sites and dated from the Roman period to the 21th century AD. The main goal consists of defining optical sensing parameters for this type of material. The considered colorants are iron, cobalt, manganese, copper and chromium. It is proved that many cases exist where optical spectroscopy can be seen as a straightforward, non-destructive, low-cost and in-situ applicable technique in identifying authentic material or to obtain information about the origin of the material. Possible sensing parameters are defined as the absence/presence of absorption bands characteristic for a specific coloring metal oxide and the spectral position of these bands. These parameters could reveal information about the applied furnace conditions and/or to the composition of the glass matrix. It is shown that the cobalt absorption band situated around 535 nm for soda rich glasses (Roman and industrial times) is shifted towards 526 nm for potash rich glasses (medieval and post-medieval times).

Abstract: Ibis work illustrates the development of X-ray fluorescence tomography and polycapillary based confocal imaging towards a three-dimensional (313), quantitative analytical method with lateral resolution levels down to the 2-20 mum scale. Detailed analytical characterization is given for polycapillary based confocal XRF imaging, which is a new variant of the 3D micro-XRF technique. Applications for 2D/3D micro-XR-F are illustrated for the analysis of biological (zooplankton) and geological samples (microscopic inclusions in natural diamonds and fluid inclusions in quartz). Based on confocal imaging, fully three-dimensional distributions of trace elements could be obtained, representing a significant generalization of the regular 2D scanning technique for micro-XRF spectroscopy. The experimental work described in this paper has been carried out at the ESRF ID18F microfluorescence end-station and at HASYLAB Beam Line L.