The combined use of IRT and LDV for the investigation of historical thin vaults

Correct interventions on cultural heritage should have as their starting point an accurate diagnosis of its health, in order to design a compatible care. NDTs seem to offer a promising way in this sense. This paper deals with the combined use of IRT and LDV for the investigation of historical thin vaults made by timber arches, reeds, and plaster and it demonstrates that they can effectively support a deeper knowledge of these vaults as it concerns the presence of detached areas among the different mortar layers of the plaster and of detached areas among the mat of reeds and the nailed connection with the wooden bearing elements. This is a very important goal because these ND methodologies can be employed only on the lower surface of these vaults and sufficiently far from it, and they do not have any mechanical interaction with the historical, eventually frescoed or stuccoed, plaster, thus saving money and time.     

The conservation of the Vecchietta's wall paintings in the Old Sacristy of Santa Maria della Scala in Siena: The use of nanotechnological cleaning agents

In the present article we report a study on some sodium dodecyl sulphate/propylene carbonate based aqueous micellar solutions developed with the aim of setting up a nanotechnological cleaning system to remove naturally aged polymeric acrylic layers from the surface of the wall paintings in the Old Sacristy of Santa Maria della Scala in Siena (15th century). Being these systems mainly composed of water (more than 70% by weight), the cleaning of the painted surface have been performed with low environmental impact, due to the small amount of the pure organic solvents used (always less than 25% by weight). Furthermore, the aqueous phase constitutes a hydrophilic barrier to the penetration of the hydrophobic acrylic materials into the porous support. Fourier Transform InfraRed spectroscopy (FTIR), Scanning Electron Microscopy coupled with Energy Dispersive X-rays analysis (SEM/EDX) and in situ capillary water adsorption measurements indicated the efficacy of this cleaning procedure. Finally, the chemical diagnostics investigation enabled to ascertain the presence of both salts (nitrates and gypsum) and the acrylic polymeric material.     

The use of hydroxyapatite as a new inorganic consolidant for damaged carbonate stones

The feasibility and the effectiveness of using hydroxyapatite (HAP) formed by reacting limestone with a solution of diammonium hydrogen phosphate (DAP) in mild conditions, as a consolidant for carbonate stones were investigated. Firstly, a novel method for predamaging limestone was developed. Then, the effects of DAP solution concentration and reaction duration were evaluated to define the best treatment conditions, and the strengthening effect was evaluated on artificially damaged Indiana Limestone samples. Treated samples exhibit a significant increase in the dynamic elastic modulus and tensile strength, which is attributed to microcrack reduction and pore filling consequent to formation of calcium phosphate phases at grain boundaries, as assessed by SEM/EDS and ESEM/EBSD. Consequent to a slight reduction of coarser pores, as revealed by MIP, the sorptivity of treated samples is only slightly reduced, so that water and water vapor exchanges with the environment are not significantly blocked.     

On the use of ASTM closed vessel tests in accelerated ageing research

The ASTM D6819-02e3 standard for testing the accelerated ageing of paper, published in 2002, recommends using closed glass vials in order to keep the degradation products in contact with the paper and thus permitting a better simulation of the natural ageing conditions inside closed books. In the present study, the actual conditions and their stability inside closed vessels have been evaluated. The necessity of assuring a very high sealing performance (tightness) of the systems in order to avoid leakage of water vapour is the main drawback of this ageing method. Systematic studies presented in this publication tried to monitor this tightness and have provided data that helped to answer the question of what circumstances could lead to achieving its improvement. Both gravimetric monitoring of water content in vials and “in situ” IR measurements of the aged paper humidity have been applied for this purpose. As a result, better sealing materials (gaskets and caps) than those recommended by the ASTM standard, have been found. Additionally, application of a dynamometric spanner for closing the vials is recommended, as this is a guarantee of reasonably high and recurring tightness of the systems used in tests. Nevertheless, the systematic, linear with time, loss of moisture for all used vials was observed. A 9% loss of the initial moisture content in samples of the aged paper was observed for the tested conditions (14 days at 90 °C). Therefore, it seems that including some kind of gravimetric control for ageing tests performed in closed vessels is of essential importance.Kinetic studies of accelerated ageing in both closed and open systems, as monitored by DP and breaking length measurements, unexpectedly show that no statistically meaningful difference of degradation rates can be observed. On the other hand, the pH and whiteness index values reveal a meaningful difference between the rates of ageing in these systems, thus confirming the basic assumption of the ASTM test concerning the interaction of paper degradation products with the paper itself.     

The presence of trapped carbon dioxide in lapis lazuli and its potential use in geo-sourcing natural ultramarine pigment

The source of the previously unassigned weak band at 2340 cm⁻¹ that is occasionally observed in the infrared spectrum of natural lapis lazuli pigment is here attributed conclusively to CO₂ trapped in the β-cage of lazurite. In addition, the geo-sourcing potential of this infrared feature for lapis lazuli is tested and found to be more ambiguous than previously suggested. The CO₂ absorption band is in fact observed in lapis lazuli samples from numerous disparate geographic locales including Afghanistan, Canada, Myanmar, Siberia, Tajikistan, and the Ural Mountains, as well as mineral hauyne samples from Germany and Italy. The spectral feature was absent from lapis lazuli samples from California, Chile, Colorado, and New York. Furthermore, poor quality lapis lazuli samples, regardless of locale, highly processed natural pigment samples, and all samples of synthetic ultramarine blue, green, and violet pigments were devoid of encapsulated CO₂.     

Unusual coin from the Parabita hoard: combined use of surface and micro-analytical techniques for its characterisation

Out of the staters collection of the National Archaeological Museum of Taranto, during the full examination of about one hundred coins minted by the Greek colony of Taras between the V century BC and the III century BC, our attention has been devoted to a lead coin, which has been regarded for many years as a genuine silver coin. This artifact, entry number 13 in the inventory list for the Parabita hoard, has been studied with the combined use of surface and micro-analytical techniques (SEM, EDX, PIXE, XRD). The joint use of different analytical techniques allowed us to obtain information about the morphology, the structure and the chemical composition of the analysed coin, that revealed a lead core coated with a bi-layer of copper and silver.     

Looking perfect: Instagram use in a Kuwaiti cultural context

This study surveys 539 Arab university students to examine gender motivational differences in Instagram use, exploring the Self-Perfectionist Personality concept and usage activities that best predict a Self-Presentation motive on Instagram. While both genders utilized Instagram mainly for Entertainment, they varied on the priority of other motives. Females were less likely to have public accounts, post personal pictures, and disclose personal information. Also, self-perfectionists of both genders excessively edited their personal pictures before posting them and were more likely to use Instagram for Self-Presentation. Outcomes are discussed in the light of the influences of culture and gender roles in Kuwait.     

戴圣生平和《礼记》的编选

戴圣是汉代著名的礼学家,治学、从政主要在汉元帝、成帝时期。先后两次为《礼》经学博士,官至九江太守。他于汉宣帝甘露三年(前51)至汉成帝阳朔四年(前21)的三十年中,以《记》百三十一篇等文献为依据,编选《礼记》四十九篇,配合今文《礼》教授弟子,传授礼学。     

孔门教《诗》与《诗》之属性嬗变

春秋后期,诗从坏乐之中蝉蜕而出,诗教变乐语之教为纯粹诗教,汇入既有之德义礼治的教育传统,从附庸走向独立。《诗》属性的这一历史性嬗替乃是籍孔门重置《诗》教目的而完成的。官学下移民间,孔子设计教育造士,立四教,分四科,观念重理想、实践重事功,以《诗》为其文教教材,并赋予其不同于乐教时代的全新目的。较之于古乐官,孔子论乐不必及诗;较之于古师儒辈,孔子论诗不必及德义。一方面持续古乐官和古师儒辈的造士理想的高调;另一方面因应时代,把《诗》教落实到向社会供应达政专对、可以言、言而文的事君、事父的人材,实现了《诗》属性的独立与重置。这既体现了夫子教《诗》的时代性和实用性,又成就了《诗》新的历史功能和身份属性。     

First experiments for the use of microblasting technique with powdered cellulose as a new tool for dry cleaning artworks on paper

This research evaluates the use of microblasting technique with powdered cellulose as a new tool for dry cleaning documents. Different cleaning tests were conducted on three documents with different properties following this new approach and the results were compared to those obtained with traditional dry cleaning with erasers. In order to assess changes caused to the supports, the treated documents were examined both before and after cleaning with optical and 3D stereomicroscopy, SEM-EDS and spectrophotometry. The results allow the conclusion that microblasting with powdered cellulose is a feasible technique to remove surface dirt or grime on paper documents. This research proves that the new use of the technique does not entail changes to the surface properties of the treated supports. Moreover, powdered cellulose is chemically stable and compatible with paper documents, preventing negative long-term effects derived from the presence of rubber residues that may remain in paper fibres when using erasers in dry cleaning treatments.