Picasso’s 1917 paint materials and their influence on the condition of four paintings

This work aims to investigate the correlation between the painting materials used by Picasso to create four artworks in Barcelona in 1917 and their actual conditions. Specifically, a range of crack types and patterns was observed in the painted layers. The paintings, kept together in Picasso’s family house until they were donated to the Museu Picasso in 1970, had significant differences in their condition, even though they present several similarities in the choice of materials, technique and in their conservation history. A multi-analytical approach was adopted to characterise the painted layers by X-ray fluorescence spectroscopy, fibre optic reflectance spectroscopy in the 350–2200 nm range, gas chromatography-mass spectrometry, and Fourier transform infrared spectroscopy. The obtained results have been combined with those from a previous analytical campaign focused on the study of grounds and canvases of these four paintings and with visual examination of the cracks to establish hypotheses about the differences in degradation. This combined overview of non-invasive documentation techniques, chemical analysis and observations of the mechanical damage has provided an insight into the possible contribution each layer could have played in the damage observed in the four canvas paintings

How good are RGB cameras retrieving colors of natural scenes and paintings?—A study based on hyperspectral imaging

RGB digital cameras (RGB) compress the spectral information into a trichromatic system capable of approximately representing the actual colors of objects. Although RGB digital cameras follow the same compression philosophy as the human eye (OBS), the spectral sensitivity is different. To what extent they provide the same chromatic experiences is still an open question, especially with complex images. We addressed this question by comparing the actual colors derived from spectral imaging with those obtained with RGB cameras. The data from hyperspectral imaging of 50 natural scenes and 89 paintings was used to estimate the chromatic differences between OBS and RGB. The corresponding color errors were estimated and analyzed in the color spaces CIELAB (using the color difference formulas ΔE*ab and CIEDE2000), Jzazbz, and iCAM06. In CIELAB the most frequent error (using ΔE*ab) found was 5 for both paintings and natural scenes, a similarity that held for the other spaces tested. In addition, the distribution of errors across the color space shows that the errors are small in the achromatic region and increase with saturation. Overall, the results indicate that the chromatic errors estimated are close to the acceptance error and therefore RGB digital cameras are able to produce quite realistic colors of complex scenarios.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020

Assessment of multispectral and hyperspectral imaging systems for digitisation of a Russian icon

In a study of multispectral and hyperspectral reflectance imaging, a Round Robin Test assessed the performance of different systems for the spectral digitisation of artworks. A Russian icon, mass-produced in Moscow in 1899, was digitised by ten institutions around Europe. The image quality was assessed by observers, and the reflectance spectra at selected points were reconstructed to characterise the icon’s colourants and to obtain a quantitative estimate of accuracy. The differing spatial resolutions of the systems affected their ability to resolve fine details in the printed pattern. There was a surprisingly wide variation in the quality of imagery, caused by unwanted reflections from both glossy painted and metallic gold areas of the icon’s surface. Specular reflection also degraded the accuracy of the reconstructed reflectance spectrum in some places, indicating the importance of control over the illumination geometry. Some devices that gave excellent results for matte colour charts proved to have poor performance for this demanding test object. There is a need for adoption of standards for digitising cultural heritage objects to achieve greater consistency of system performance and image quality

Fabrication and electrical characterization of three-dimensional graphitic microchannels in single crystal diamond

We report on the systematic characterization of conductive micro-channels fabricated in single-crystal diamond with direct ion microbeam writing. Focused high-energy (~MeV) helium ions are employed to selectively convert diamond with micrometric spatial accuracy to a stable graphitic phase upon thermal annealing, due to the induced structural damage occurring at the end-of-range. A variable-thickness mask allows the accurate modulation of the depth at which the microchannels are formed, from several {\mu}m deep up to the very surface of the sample. By means of cross-sectional transmission electron microscopy (TEM) we demonstrate that the technique allows the direct writing of amorphous (and graphitic, upon suitable thermal annealing) microstructures extending within the insulating diamond matrix in the three spatial directions, and in particular that buried channels embedded in a highly insulating matrix emerge and electrically connect to the sample surface at specific locations. Moreover, by means of electrical characterization both at room temperature and variable temperature, we investigate the conductivity and the charge-transport mechanisms of microchannels obtained by implantation at different ion fluences and after subsequent thermal processes, demonstrating that upon high-temperature annealing, the channels implanted above a critical damage density convert to a stable graphitic phase. These structures have significant impact for different applications, such as compact ionizing radiation detectors, dosimeters, bio-sensors and more generally diamond-based devices with buried three-dimensional all-carbon electrodes

Advances in multispectral and hyperspectral imaging for archaeology and art conservation

Multispectral imaging has been applied to the field of art conservation and art history since the early 1990s. It is attractive as a noninvasive imaging technique because it is fast and hence capable of imaging large areas of an object giving both spatial and spectral information. This paper gives an overview of the different instrumental designs, image processing techniques and various applications of multispectral and hyperspectral imaging to art conservation, art history and archaeology. Recent advances in the development of remote and versatile multispectral and hyperspectral imaging as well as techniques in pigment identification will be presented. Future prospects including combination of spectral imaging with other noninvasive imaging and analytical techniques will be discussed

Developing a regional environmental information system based on macro-level waste indicators

Waste information is necessary for proper management planning. However, data on waste generation and management are sometimes not reliable enough, do not exist or are not useful for the sector. This is due to the high number of waste types and flows, and actors (producers, managers and administrations),which make data collection and treatment difficult. Furthermore, data loss occurs because some waste flows have economic value and return to the second-hand markets without monitoring. The development of a waste information system for a region is more than just about establishing a routine data collection on waste. It is a way to support the challenges of decision-making on waste management. These challenges range from strategic issues of waste management in the national government to the basic challenges of running local governments. In the Cantabrian region, three indicator sets were defined to constitute the waste information system:(a) a Basic Indicator Set, which provides an overview of the status of the generation and management of the main waste streams, giving a national and international comparative analysis of the situation; (b) a Specific Indicator Set, which monitors the objectives of the different waste policies, and (c) a Transverse Indicator Set, which analyses the influence of different economic and social variables on the generation of specific waste streams. The Waste Information System of the Cantabrian Region has been created using a specific methodology for developing indicator sets with multiple objectives. This methodology consists of seven steps: (i) the synthesis, selection of the indicators sets; (ii) analysis of the system under study and data sources;(iii) evaluation of the indicators proposed; (iv) application and interpretation; (v) public review, dissemination and updating protocol; (vi) improvement of indicators sets using SWOT analysis; and (vii) aggregation of all indicators in an aggregated index. These indicator sets with a total of 27 indicators allow tracking the evolution of generation and management of waste streams and the achievement of the policy objectives, establishing a data record, evaluating the data and sources of data, monitoring proposed action and its effectiveness summarizing large amounts of data on waste in order to spread it to the public and finally, aggregate all information in a single index that allows the evaluation of the evolution of all waste sectors in time.This work has been supported by the Cantabrian Government R&D project entitled “Establishing the set of indicators for sustainable resource and waste flow in the region of Cantabria”. Eva Cifrianwas funded by the University of Cantabria on a Ph.D. fellowship

Cost-Effectiveness of Chagas Disease Vector Control Strategies in Northwestern Argentina

Despite decreasing rates of prevalence and incidence, Chagas disease remains a serious problem in Latin America, especially for the rural poor. Without vaccines, control and prevention rely mostly on residual spraying of insecticides. Under the aegis of the Southern Cone Initiative, and in agreement with global trends in decentralization of the health systems, in 1992 the Argentinean vector control launched a new vector control program based on community participation. The present study represents the first thorough evaluation of the overall performance of such vector control program and the first comparative assessment of the cost-effectiveness of different vector control strategies in a highly endemic rural area of northwestern Argentina. Supported by results of independent studies, the present work shows that in rural, poor and dispersed areas of the Gran Chaco region, the implementation of a mixed (i.e., vertical attack phase followed by horizontal surveillance) strategy constantly supervised and supported by national or local vector control programs would be the most cost-effective option to interrupt vector-borne transmission of Chagas disease

Notulae to the Italian native vascular flora: 3.

In this contribution new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, exclusions, and confirmations to the Italian administrative regions for taxa in the genera Asplenium, Bolboschoenus, Botrychium, Chamaerops, Crocus, Galeopsis, Grafia, Helosciadium, Hieracium, Juniperus, Leucanthemum, Lolium, Medicago, Phalaris, Piptatherum, Potamogeton, Salicornia, Salvia, Seseli, Silene, Spiraea, Torilis and Vicia. Rhaponticoides calabrica is proposed as synonym novum of R. centaurium. Furthermore, new combinations in the genera Galatella and Lactuca are proposed