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The phoenician red slip ware: a multi-analytical study of a technological marker among the shores of the Mediterranean Sea
Full text linkLa presente tesi di dottorato riporta i risultati dell’indagine archeometrica condotta su ceramiche fenicie in Red Slip Ware (RSW), datati tra il secolo IX a.C. e l'inizio del V secolo a.C.
I campioni provengono da Mozia (Sicilia-Italia), Sulky (Sardegna-Italia), Cadice (Spagna), Mogador (Marocco), Ramat-Rahel (Israele), Tas Silg (Malta) e Pantelleria (Italia).
La caratteristica principale di questa classe ceramica è l'aspetto esterno, simile in tutti i contesti archeologici, caratterizzato da una decorazione rossa lucida.
Lo scopo di questa tesi è di individuare parametri mineralogici, chimici e microstrutturali che possano essere utili per discriminare tra campioni di diversa origine, nonostante il loro aspetto esterno simile.
Al fine di ricostruire il background tecnologico e identificare le materie prime utilizzate, il corpo ceramico e la decorazione sono stati studiati mediante Microscopia Ottica (OM), Diffrazione di Raggi X su Polveri (XRPD), Microscopia Elettronica a Scansione abbinata al sistema EDS (SEM-EDS), Analisi in Microsonda Elettronica (EMPA) e Voltammetria di Microparticelle Immobilizzate (VIMP), una tecnica micro invasiva.
Sono stati studiati quaranta campioni di Motya. I risultati suggeriscono un'attenta selezione delle materie prime (ovvero, argilla carbonica illitica e inclusioni), cotte a temperature comprese nell'intervallo >800 e <900 °C, in condizioni ossidanti. Il confronto della composizione mineralogica e chimica tra i depositi di argilla locale ed i campioni ceramici, unitamente alle differenze produttive, hanno permesso di distinguere i prodotti locali (due fabric che contano 36 campioni) dai quelli importati (tre fabric, che contano 4 campioni). La decorazione Red Slip è costituita da un rivestimento ricco di argilla, arricchito in Fe, ne sono state identificate tre tipologie differenti.
Gli otto campioni di Sulky sono divisi in un fabric principale più un campione loner. I dati suggeriscono temperature di cottura comprese tra 800 e 900 °C e l'uso di materie prime, povere in Ca, simili per corpo ceramico e decorazione. I dati XRPD consentono di identificare l’associazione quarzo + cristobalite + tridimite, tipica delle ignimbriti del distretto vulcanico del Sulcis. Le analisi sottolineano inoltre che due diverse miscele ricche di Fe sono state utilizzate per decorare i campioni del fabric e del campione loner.
I trenta campioni di Cadice provengono da due siti archeologici fenici (Cánovas del Castillo del VIII secolo a.C. e la Necropoli del VI secolo a.C.). I campioni di entrambi i contesti sono raggruppabili in due fabric, inoltre è stato identificato un campione loner. I microfossili di origine marina sono molto comuni in tutti i campioni, ma mentre nei due fabric prevalgono gli organismi bentonici, nel loner sono presenti quasi esclusivamente esemplari planctonici. I campioni, composti da argilla illitica ricca di Ca, sono stati cotti nell'intervallo di temperatura 700-850 °C in condizioni ossidanti. Il contenuto di microfossili, la presenza di monazite e framboidi di ossidi di Fe, sono compatibili con i sedimenti rinvenuti nell'area della baia di Cadice; solo il loner, realizzato con materie prime totalmente diverse, è stato probabilmente importato.
Infine, le analisi elettrochimiche hanno permesso di discriminare i manufatti provenienti dallo stesso sito e da siti diversi.
Le considerazioni finali sembrano supportare l’ipotesi che i Fenici preferissero produrre la RSW utilizzando materiale locale ma tramandando il loro know-how nelle colonie e commercializzando/importando solo pochissimi manufatti.The present PhD thesis reports the results of the archaeometric investigation on the Phoenician Red Slip Ware (RSW) artefacts dated back between the 9th century BC and the early 5th century BC.
The studied samples come from Motya (Sicily-Italy), Sulky (Sardinia-Italy), Cádiz (Spain), Mogador (Morocco), Ramat-Rahel (Israel), Tas Silg (Malta), and Pantelleria (Italy).
The main feature of this ceramic class is the external macroscopic appearance, similar in all archaeological contexts, characterized by a shiny red decoration.
The aim of this thesis is to individuate compositional and technological parameters, which can be useful to discriminate among samples of different provenance, despite their similar external appearance.
In order to reconstruct the technological background and to identify the nature of the raw materials, the body and decoration have been investigated using Optical Microscopy (OM), X-ray Powder Diffraction (XRPD), Scanning Electron Microscopy coupled with EDS system (SEM-EDS), Electron Microprobe Analysis (EMPA) and Voltammetry of Immobilized Microparticles (VIMP).
The results on forty samples from Motya suggest a careful selection of the raw materials (i.e., illitic carbonate clay and inclusions) and firing temperature in the range >800 and <900 °C, under oxidizing conditions. The comparison of the mineralogical and chemical composition of local clay deposits with that of the ceramic products and differences in the manufacture allowed to distinguishing local (two fabrics, counting 36 samples) from imported vessels (three fabrics, counting 4 samples). The Red Slip decoration consists of clay-rich coating, enriched in Fe. Three different typologies of slips have been identified.
The eight samples from Sulky are divided in one main fabric and one loner sample. The data suggest firing temperature in the range 800 – 900 °C and the use of similar Ca-poor raw materials for both the body and decoration. XRPD data, acquired in transmission mode along with Rietveld refinements, permit to identify the unusual quartz + cristobalite + tridymite association, typical of the ignimbrites of the volcanic district of Sulcis. This analysis outlines that two different Fe-rich mixtures have been used to decorate the samples of the fabric and the loner.
The thirty samples from Cádiz come from two Phoenician archaeological site, one of the 8th century B.C. (Cánovas del Castillo) and the other from the 6th century BC (the Necropolis). The samples are divided in two fabrics (unimodal and bimodal) moreover a loner sample has been identified. Microfossils of marine origin are very common in all samples but in both the two fabrics benthic organisms prevail, while in the loner almost only planktonic specimens occur. The analysis permits to identify the use of Ca-rich illitic clay, fired in the range of 700-850 °C. The microfossils content, the presence of Fe oxides framboidal microstructures and monazite, are compatible with the sedimentary rocks of the area of the bay of Cádiz; probably only the loner sample, made with totally different raw materials, has a foreign origin.
Finally, the electrochemical fingerprints discriminate between different vessels of pottery among that recovered in the same site, and between equivalent potteries from different sites.
Considering all these data it is possible to hypothesize that the Phoenicians preferred to produce the RSW on site, handing down the technological knowledge in the colonies, using local raw materials, and marketing/importing only very few artefacts
Archaeometric characterization of Middle Bronze Age pottery from Borg in-Nadur village
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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
Nature of pigments in natural and cultured pearls by using Raman spectroscopy
No full textAmong organic gems, pearls are widely used for decorating artworks and precious jewels; due to their attributes of beauty, they are also in high demand in the nowadays gemstone trade.
The nature of color in pearls is still debated, even if recent studies have attributed to mixtures of methylated (carotenoids) or non-methylated polyenes with different UV-VIS absorption spectra and chain lengths [1]. Previous studies have demonstrated the potential of Raman spectroscopy in detecting pigments in cultured freshwater pearls [2].
With the aim to improve knowledge on the nature of pigments in natural and cultured pearls, several pearls species (Japanese cultured saltwater, Chinese natural and dyed freshwater, oriental natural, Tahitian cultured pearls) have been investigated by Raman spectroscopy using several equipment (laboratory set-up vs. portable) and excitation sources (632.8, 532, 473.1 nm).
Colored natural species showed characteristic Raman double peak indicating pigment belonging to the carotenoid family, with C-C (ν2) and C=C (ν1) stretching modes at 1159 cm-1 and at 1516 cm-1. Overtones and combination modes are observed for all species up to > 4000 cm-1 at 473 nm, in resonance conditions. The ν2 and ν1 frequencies depend on the polyene chain length, i.e. on the number N of the conjugated double bonds. The Raman spectra of pinkish pearls may be interpreted on the basis of a mixture of polyene pigments with different chain lengths. A linear relationship between ν1 and ν2 and a simple approximate rule for their dependence on N: ν1 = 254*103/(N+157); ν2 = 189*103/(N+157) has been proposed [1]. On this basis, contributions from N=6 to N=11 may be found by peak deconvolution.
Polyenes have been identified as responsible of color in freshwater and saltwater pinkish and yellowish pearls; finally, in some Chinese freshwater pearls Raman spectra suggested the use of synthetic dyes.
Aknowledgements
The authors are very grateful to the gemmologist Ugo Longobardo for having provided the studied pearls.
References
[1] L. Bergamonti, D. Bersani, D. Csermely, P.P. Lottici, Spectroscopy Letters 2011, 44, 453.
[2] S. Karampelas, E. Fritsch, J.Y. Mevellec, J.P. Gauthier, S. Sklavounos, T. Soldatos, J. Raman Spectrosc. 2007, 38, 217
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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