1,720,988 research outputs found
Minero-geochemical transformations induced by lichens in the biocalcarenite of the Selinuntine monuments
No full textGeneral Processes of Biodeterioration of Materials of Plant Origins
No full textWe describe the processes of biodeterioration of cellulos
Cyanobacteria cause black staining of the National Museum of the American Indian Building, Washington D.C., USA
No full textMicrobial deterioration of stone is a widely recognised problem affecting monuments and buildings all over the world. In this paper, dark-coloured staining, putatively attributed to microorganisms, on areas of the National Museum of the American Indian Building, Washington, DC, USA, were studied. Observations by optical and electron microscopy of surfaces and cross sections of limestone indicated that biofilms, which penetrated up to a maximum depth of about 1 mm, were mainly composed of cyanobacteria, with the predominance of Gloeocapsa and Lyngbya. Denaturing gradient gel electrophoresis analysis revealed that the microbial community also included eukaryotic algae (Trebouxiophyceae) and fungi (Ascomycota), along with a consortium of bacteria. Energy-dispersive X-ray spectroscopy analysis showed the same elemental composition in stained and unstained areas of the samples, indicating that the discolouration was not due to abiotic chemical changes within the stone. The dark pigmentation of the stone was correlated with the high content of scytonemin, which was found in all samples
Le Storie di Ester di Paolo Veronese in San Sebastiano. Studio dei processi esecutivi attraverso la diagnostica per immagini
No full textStudio dei materiali e della tecnica esecutiva del ciclo di Ester di Paolo Veronese tramite radiografia RX e riflettografia IR multispettrale a scansione in occasione del restauro presso la soprintendenza di Venezi
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
Museums
No full textMuseums are depositories for objects of historical, artistic, or scientific value. For historical reasons, most Italian museums are located in historic buildings, public structures or palaces built by the nobility, roial palaces, ecclesiastical complex or convents. The microclimate conditions inside museums are strongly influenced by the location and geography of the site. In this work we expose the problems of biodeterioration and the most frequently identified fungal and bacterial species from artifacts and from air in museum
Fungi.
No full textFungi play an important role in the degradation of cultural property. Fungi exercise a direct action on organic materials utilized as nutrients as well as indirect actions on inorganic materials. We describe the characteristics of such organisms in relation to their action on cultural materials
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