1,720,965 research outputs found
A Critical Review on the Analysis of Metal Soaps in Oil Paintings
Full text linkUp to 70 % of the oil paintings conserved in collections present metal soaps, which result from the chemical reaction between metal ions present in the painted layers and free fatty acids from the lipidic binders. In recent decades, conservators and conservation scientists have been systematically identifying various and frequent conservation problems that can be linked to the formation of metal soaps. It is also increasingly recognized that metal soap formation may not compromise the integrity of paint so there is a need for careful assessment of the implications of metal soaps for conservation. This review aims to critically assess scientific literature related to commonly adopted analytical techniques for the analysis of metal soaps in oil paintings. A comparison of different analytical methods is provided, highlighting advantages associated with each, as well as limitations identified through the analysis of reference materials and applications to the analysis of samples from historical paintings
Protection of dinosaur footprints in carbonate deposits: the case of Sezze (Latium, central Italy) ichnosite
No full textMore than 200 dinosaur footprints were found on three stratigraphic surfaces in the abandoned quarry “Cava Petrianni”, about 70 km south of Rome, nearby the town of Sezze (Latium, central Italy). The ichnosite is located in the westernmost sector of the Lepini Mts., with an exposed carbonate succession belonging to the Lepini-Ausoni-Aurunci Unit. Three distinct trampled surfaces were recognised in a 250-m-thick succession referred to the “Laziale-Abruzzese-Campano domain” deposited in a persistent shallow carbonate platform setting from the Late Triassic to the Late Cretaceous. The footprints, preserved on carbonate platform limestones, are exposed to natural environment degradation (especially karst processes), that can irreversibly modify track morphology, resulting in the loss of details in a site of unique paleontological and paleobiogeographic value (Antonelli et al., 2023). The aim of the present project is to find an appropriate solution in the long-term preservation of dinosaur footprints produced in carbonate deposits from the environmental degradation naturally occurring in paleoichnological and geological sites. The final purpose is both enhancing this palaeontological heritage and proposing a possible solution applicable to other ichnosites with similar conditions. Several consolidants have been tested on the trampled surfaces to evaluate the better in terms of application, costs and results. In particular, a mineral consolidant based on the sol-gel technology (SIOX-5 RE50), a nano-sized silicon dioxide fixative/consolidant in colloidal aqueous dispersion (Nano ESTEL) and TEOS with chitosan were applied. In addition, a bioconsolidation process was tested, applying several bacterial strains, taking advantage from the natural bacterial ability to induce carbonate precipitation (Nigro et al., 2022).
Antonelli M., Romano M., De Sario F., Pignatti J., Sacco E. & Petti F.M. (2023) - Inferred oviraptorosaur footprints in the Apenninic Carbonate Platform: New tools for the identification of trackmakers from the Sezze ichnosite (lower-middle Cenomanian; central Italy). Cretaceous Res., 141, 105362. https://doi.org/10.1016/j.cretres.2022.105362.
Nigro L., Mura F., Toti M.P., Cirigliano A. & Rinaldi T. (2022) - Carbonatogenic bacteria on the ‘Motya Charioteer’ sculpture. J. Cult. Herit., 57, 256-264. https://doi.org/10.1016/j.culher.2022.09.009
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Isolation of carbonatogenic bacteria for biorestoration
No full textBiomineralization of calcium carbonate by living organisms, including bacteria, has been studied for its potential use in conservation and restoration applications in Cultural Heritage. This study reports the carbonatogenic properties of three bacterial strains (Lysinibacillus fusiformis 3.20, Psychrobacillus psychrodurans 7Mo and Lederbergia lenta Vetro1) isolated from Il Giovane di Mozia sculpture (Mozia), the Etruscan mural paintings of the Tomba degli Scudi (Tarquinia), and a microbial community isolated from the Sant'Eustachio statue (Matera). The crystals precipitated have been investigated through a multi-analytical approach: Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The analyses showed the formation of stable vaterite by the bacterial cultures, while the microbial community induced calcite precipitation. This approach aims to support the conservation-restoration efforts, taking into the account the requests of the conservation-restorers and the unique characteristics of each Cultural Heritage artwork
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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