1,720,987 research outputs found
Multi-analytical Approach for the Characterisation of Ancient Mineral Fibres: Tracing the Use of Asbestos in the Italic Peninsula
No full textThis paper presents the multi-analytical approach performed by microscopic analysis using Optical and Scanning Electron Microscope (SEM-EDX) and Raman spectroscopy. These techniques allow us to recognise asbestos fibres and precisely characterise their mineral nature. Using Raman micro-spectroscopy, which is often used to discriminate tiny mineral fibres, it was possible to precisely characterise the mineral composition of the asbestos fibres from ancient central-southern Italy by comparing their manufacture through the identification of the specific asbestos phase.
The results obtained highlight the extraction activity of the mineral fibres and the use of long hair-like fibres to manufacture textile objects in the ancient Italic Peninsula
THE ROLE OF DUAL TASK AND TASK SWITCH IN PROSPECTIVE MEMORY:BEHAVIOURAL DATA AND NEURAL CORRELATES
No full textEvent-basedprospectivememory (PM) requires remembering the delayedexecution of an intendedaction
in response to a pre-specified PMcue while being actively engaged in an ongoing task in which the cue is
embedded. To date, experimental paradigms vary as to whether or not they require participants immediately
to stop working on the ongoing task whenever they encounter a PM event (cue) and directly
switch to the prospective action (task-switch approach). Alternatively, several other paradigms used in
the literature encourage participants to continue working on the ongoing task item after the cue, and
only then, perform the prospective action (dual-task approach). The present study explores the possible
behavioural and electrophysiological effects that both approaches may have on PM performance. Seventeen
young adults performed both versions of a standard PMtask in a counterbalanced order during which
behavioural data and electroencephalogram (EEG) were recorded. Behavioural data showed a decrement
inPMperformance in the task-switch compared to the dual-task condition. In addition, EEG data revealed
differences between the dual-task and task-switch approach in event-related potential (ERP) components
associated with response inhibition and with post-retrieval monitoring (i.e. late positive complex). No
differences between the two taskswere found with regard to thePMevent detection processes (i.e. N300)
and the retrieval of the intended action fromlong-term memory. In sum, findings demonstrate that it does
make a difference which task approach is applied and suggest that dual-task and task-switch paradigms
may result in different processing and neurophysiological dynamics particularly concerning attentional
resources and cognitive control
A novel approach to control biodeterioration of wooden made materials based on R-(+)-pulegone loaded chitosan nanoparticles
No full text
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
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
A whiter shade of vase. Discovering the white colors of an ancient Apulian krater through XRPD and Raman spectroscopy
Full text linkRaman spectroscopy and X-Ray Powder Diffraction were applied in order to characterize the materials used for the manufacturing of an ancient, decorated vase of Apulian manufacturing in 4th century B.C. In this case study, three small fragments from one vase were sampled from pictorial areas in black and white. X-Ray Diffraction on a powdered sample was applied to characterize the composition of ceramic: the analysis allowed the identification of quartz, plagioclase and diopside and consequent hypotheses about the production process. The pictorial decorations in black and white were analysed through Raman spectroscopy. While the pigment constituting the dark areas was identified as maghemite γ-Fe2O3, an iron oxide with spinel structure, which suggests a maghemization oxidative process, in the white decoration it was possible to individuate the presence of both anatase -an allotropic phase of titanium oxide- and α-alumina. The application of alumina as pigment results peculiar and it represents a new knowledge advancement, which is worth of further studies. The combination of anatase and alumina suggested hypotheses about the origin of the starting materials for the white decorations, with reference to the manufacturing period and area. This set of data resulted in new information about the Apulian vase production, enriching the knowledge about a less popular pottery typology and opening new perspectives about commercial and cultural exchanges
NYMPHA, a natural product for the conservation of ancient wood
No full textIn recent years, there has been a significant interest on sustainability and health-safety across various domains. Notably, many traditional chemicals employed in the preservation of Cultural Heritage pose environmental and human health risks. The NYMPHA project aimed to develop an eco-friendly solution using microalgae-derived polysaccharides to remove biological patinas from cultural heritage wooden materials, addressing sustainability and health concerns. To validate its efficacy, the product underwent testing on diverse woods such as silver fir, beech, and sessile oak, selected for their distinct anatomical characteristics. The analytical methodology involves three key steps: 1) determining the optimal extraction and application method through spectro-colorimetric measures and UV imaging; 2) evaluating surface color stability; and 3) assessing the product's effectiveness before and after exposure to a biological attack using spectro-colorimetry.
Results indicate that the NYMPHA product can induce a color variation on some wood surfaces. Moreover, although it is reported that algae can have biocidal effects, in this experiment, this action is not observed probably due to the absence of sulphates in the polysaccharide molecule extracted from this specific strain. This emphasizes the necessity for further research and to explore new solutions beyond controlled laboratory conditions, specifically on naturally degraded materials
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