Study of the gilding technique used in polychromed stones and ceramics by dedicated laboratory-made micro X-ray diffraction and complementary techniques

This work describes the use of a new dedicated laboratory-made micro X-ray diffraction system for detecting the phases present in cross-sections of artworks. As an example, the phases present in samples from gilding ceramics and stone sculptures from the heritage of Seville (Spain) were successfully detected using this new system, which takes advantage of various devices developed for synchrotron radiation, and is complemented by the information provided by other techniques.     

Analysis and Protection of One Thousand Hand Buddha in Dazu Stone Sculptures

The components of the rock, the pigments, the gold foils and the adhesive of One Thousand Hand Buddha in Dazu stone sculptures, Chongqing, China, have been analyzed by X-ray diffraction (XRD), X-ray fluorescence (XRF), infrared spectroscopy (IR), energy dispersive X-ray analysis (EDX) and fiber optics reflectance spectroscopy (FORS). Furthermore, the weathering and degeneration of One Thousand Hand Buddha have been discussed and the protective methods have been provided. In this work some useful information to study on conservation of stone relics is given.     

Thermal analytical investigation of ancient mortars from gothic churches

The use of thermal analysis in studying ancient mortars in English cathedrals is explained. Thermal analysis can be used to investigate both mortar and stone in dated structures. Analysis of ancient mortars show that though recarbonated, they remain soft, yielding to structural deformations. The use of hard (cement mortar) in modern renovation can result in micro-cracking in the stone and subsequent chemical attack from the atmosphere. Contrary to the literature, data developed in the present study suggests that most medieval mortars have reached a near total state of recarbonation.     

Nuclear techniques applied to provenance and technological studies of Renaissance majolica roundels from Portuguese museums attributed to della Robbia Italian workshop

Artistic and historical examination of high-quality glazed terracotta sculptures displayed in various Portuguese museums point to their production in della Robbia workshop of Florence (Italy). A multitechnique analytical approach is applied for the first time to these sculptures, aiming to confirm their origin. Materials were analyzed using Instrumental Neutron Activation Analysis, Prompt Gamma Activation Analysis and X-ray Diffraction. The compositional results are similar to other della Robbia sculptures, suggesting a common origin for the raw material that was identified as carbonate rich marine origin marly clay. The applied firing temperatures was proved to be around 900 °C. The differences found within each sculpture are explained by the production technique of assembling separate parts to produce these huge sculptures, and the clay pit heterogeneity.     

Formation of Hydrophobic Silica Coatings on Stones for Conservation of Historic Sculptures

The conservation of historic sculptures is receiving growing attention because of the increasing air pollution. A hydrophobic silica coating was synthesized to protect historic sculptures from weathering by starting from a solution of tetraethoxyorthosilicate (TEOS) precursor using hexadecyltrimethoxysilane (HDTMS) as hydrophobic modifier in the presence of ammonia as a catalyst. The molar ratio of ethanol, TEOS, H₂O and NH₄OH was kept constant at 8:0.045:3:2.8 and the molar ratio of HDTMS/TEOS (M) was varied from 0 to 0.458. The organic modification was confirmed by infrared spectroscopic studies, and the hydrophobicity of the coating was tested by the contact angle measurements. The stone surface morphology of sample treated with silica coating was characterized. The results showed that the nanocomposites were composed of spherical particles with grain size of about 190 nm in diameter. After the limestone's surface was modified, the contact angle of limestone increased from 20° to 100° for M0.458. The protective performance evaluated with its ability to resist acid rain reveals that the protective effects are satisfying.     

聚丙烯酸酯－环氧树脂IPN乳液的合成

研究摩岩石刻保护材料聚丙烯酸酯-环氧树脂互穿聚合物网络乳液的合成,讨论影响凝聚率,乳液稳定性和乳液胶膜耐水性、吸水率的因素,得到最佳工艺条件。     

Differentiation of human kidney stones induced by melamine and uric acid using surface desorption atmospheric pressure chemical ionization mass spectrometry

Clinically obtained human kidney stones of different pathogenesis were dissolved in acetic acid/methanol solutions and then rapidly analyzed by surface desorption atmospheric pressure chemical ionization mass spectrometry (SDAPCI-MS) without any desalination treatment. The mass spectral fingerprints of six groups of kidney stone samples were rapidly recorded in the mass range of m/z 50-400. A set of ten melamine-induced kidney stone samples and nine uric acid derived kidney stone samples were successfully differentiated from other groups by principal component analysis of SDAPCI-MS fingerprints upon positive-ion detection mode. In contrast, the mass spectra recorded using negative-ion detection mode did not give enough information to differentiate those stone samples. The results showed that in addition to the melamine, the chemical compounds enwrapped in the melamine-induced kidney stone samples differed from other kidney stone samples, providing useful hints for studying on the formation mechanisms of melamine-induced kidney stones. This study also provides useful information on establishing a MS-based platform for rapid analysis of the melamine-induced human kidney stones at molecular levels.     

Application of gas chromatography-mass spectrometry analysis to the study of works of art: paint media identification in polychrome multi-material sculptures

A new gas chromatographic-mass spectrometric procedure for characterizing both drying oils and proteinaceous binders in samples of painted artworks has been developed. Furthermore, a new analytical procedure for analysis of polysaccharide materials through identification of the monosaccharide constituents is proposed. The methods have been applied to characterizing binding media of the different layers of the polychrome surface in the multi-material sculptures from the sanctuary of Santa Maria delle Grazie in Mantova, Italy. It was found that animal glue was the main binder in the priming layer of all statues, whereas more complex mixtures were used in the paint layers. Generally, a drying oil was present, most often linseed oil alone or in combination with other organic binders.     

Elucidation of molecular and elementary composition of organic and inorganic substances involved in 19th century wax sculptures using an integrated analytical approach

Wax sculptures contain several materials from both organic and inorganic nature. These works of art are particularly fragile. Determining their chemical composition is thus of prime importance for their preservation. The identification of the recipes of waxy pastes used through time also provides valuable information in the field of art history.The aim of the present research was to develop a convenient analytical strategy, as non-invasive as possible, that allows to identify the wide range of materials involved in wax sculptures.A multi-step analytical methodology, based on the use of complementary techniques, either non- or micro-destructive, was elaborated. X-ray fluorescence and micro-Raman spectroscopy were used in a non-invasive way to identify inorganic pigments, opacifiers and extenders. The combination of structural and separative techniques, namely infrared spectroscopy, direct inlet electron ionisation mass spectrometry and high temperature gas chromatography, was shown to be appropriate for unravelling the precise composition of the organic substances. A micro-chemical test was also performed for the detection of starch.From this study it has been possible to elucidate the composition of the waxy pastes used by three different sculptors at the end of the 19th century. Complex and elaborated recipes, in which a large range of natural substances were combined, were highlighted.     

Provenance studies of pottery fragments from medieval Cairo, Egypt

In the analysis of archeological pottery fragments, instrumental neutron activation analysis has been utilized to establish the elemental concentrations of up to 37 chemical elements for each of 53 archeological pottery samples from medieval Cairo, Egypt, and one additional sample of Chinese porcelain. These elemental concentrations have been utilized in a statistical analysis procedure in order to determine similarities and correlations between the various samples. Multivariate analyses have been used to quantitatively determine these interrelationships. This methodology successfully separated the Egyptian samples into two broad categories: (1) polychrome decorated ceramic ware and (2) monochrome celadon ware. In addition the methodology successfully identified the one unique sample of Chinese porcelain. Several samples appeared to be either a mixture of categories or outliers in the data set and were not attributable to any distinct category.     

A study for the characterization of binding media from medieval polychrome sculptures by gas chromatography-mass spectrometry

Summary Binding media in samples taken from XIIth–XIIIth century polychrome sculptures in the Baptistery of Parma (Italy) were characterized by gas chromatography-mass spectrometry, after hydrolysis and derivatization procedures. The use of SE-52 capillary columns and the application of selected ion monitoring (SIM) allowed an increasing in the sensitivity and the ability to differentiate between animal glues, casein, egg and drying oils as components of the binders of paint and ground layers. Small amounts of material were enough for a satisfactory characterization.     

Element determination in medieval soil samples by total reflection X-ray fluorescence analysis

An aqua regia extraction procedure for heavy metals in soils optimised for total reflection X-ray fluorescence analysis is presented. The procedure is applied to 92 soil samples of medieval layers from the city area of Dortmund. Sixteen elements (P, S, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Ag, Sn, and Pb) were used to characterise 17 sample sites. The results are projected onto the medieval urban structure of Dortmund. Two sites loaded with non-ferrous heavy metal could be detected and correlated with archaeological data. The efficiency and repeatability of the proposed extraction procedure is discussed.     

FT-Raman spectroscopic analysis of pigments from an Augustinian friary

The Raman spectroscopic analysis of several stone samples with applied red pigments obtained from an archaeological excavation of an Augustinian friary discovered during the construction of an extension to Hull Magistrates Court in 1994 has revealed a surprising diversity of composition. Cinnabar, red lead and haematite have all been identified alone or in admixture; the cinnabar is exceptional in that it has only been found heavily adulterated with red ochre and red lead, as the other two pigments are found alone. There are signatures of limewash putty, which has been applied to the stone substrate prior to the painting, which is characteristic of the Roman method of wall painting, and there are no traces of gypsum found in the specimens studied. This evidence indicates an early mediaeval method of stone decoration.     

Synthesis and properties of fluorosilicon compounds for protection of cultural monuments from harmful environmental exposure

Methods for the synthesis of perfluorocarboxylic acid derivatives with reactive trialkoxysilyl groups soluble in organic and organofluorine (1,1,2-trichlorotrif1uoroethane, etc.) solvents have been developed. The contact angles of water and decalin, water absorption, resistance to freezing, and salt-resistance of limestone and plaster samples treated with these compounds were determined. Fluorosilicon organic compounds impart more hydro- and oleophobic properties to the protected surfaces than known organosilicon agents and reliably protect sculptures and architectural monuments from mold and algae deposition.     

鲁北地区人体结石的成分及成因分析

采用X射线衍射（XRD）、红外光谱（IR）和扫描电子显微技术（SEM）对鲁北地区22例手术取出的人体结石标本进行了分析。用原子吸收光谱分析（AAS）对鲁北地区饮用水中的微量元素进行了测定。结果表明鲁北地区的人体胆结石主要有胆固醇结石、胆色素结石和泥砂质结石,其中以泥砂质结石较多,未发现混合结石。该地区尿路结石中,上尿路（肾、输尿管）结石以草酸钙、尿酸结石为主,下尿路（膀胱）结石以鸟粪石（六水磷酸镁氨）、羟基磷灰石为主,未发现尿道结石。该地区的人体结石的形成与当地的环境和水质有关。     

Investigation of the origin of archaeological glass artefacts by means of pattern recognition

The origin of medieval glass artefacts is studied by using a supervised learning technique, which is shown to be helpful when samples cannot be identified by typical design and appearance. A set of seventy pieces of glass was analyzed for ten trace elements by optical emission spectrography. The data matrix of 33 known objects from five origins was evaluated by multivariate variance and discriminant analysis in a training step. The extracted non-elementary discriminant functions were used to classify the 37 unidentified samples. The classification result is discussed in terms of its cultural/historical information content.     

A combinative technique to recognise and discriminate turquoise stone

This study attempts to identify and categorize turquoise stone based on its compounds and major factors that introduces its color change. Turquoise samples which are investigated in this study have been collected from the most important turquoise mines in world. Combination of two different analysis methods assists this study for scrutinizing turquoise constituents and effects of their percent on its color change. The application of infrared spectroscopy and X-Ray Fluorescence (XRF) methods can reveal the true composition of various “turquoise” samples in range of blue color to green color. Whereas the first technique (FTIR) is especially capable in diff ;erentiating between natural samples and fake or simulant stones for prevent of jobbery. Changing percent of four compounds including CuO, Al₂O₃, P₂O₅ and Fe₂O₃, is the most effective factors of varying color in turquoise stones. In conclusion, blue turquoise stone contains great percent of light elements or blue color factors in comparison to green turquoise stone which contains jorum of heavy element.     

Characteristics of the Porous Structure of Cement Stone

The complex study of filtration and electric properties of the samples of cement stone with different water-cement ratios is performed. It is established that filtration coefficient decreases by 4–6 times with an increase in a pressure drop and becomes constant at pressure drops above 3–3.5 MPa. The observed effect is interpreted as a reversible change in the internal structure of cement stone upon the filtration of a liquid through the stone. It is revealed that the filtration coefficient and porosity of samples decrease with time. Total open porosity and the most probable pore radius are determined by mercury porosity technique. Coefficients of structural resistance and pore tortuosity of the samples are determined from the comparison of through and total porosity. The values of streaming potential are measured and values of surface charge and potential of the samples of cement stone are calculated.     

Scanning electron microscopy and energy dispersive analysis: applications in the field of cultural heritage

Scanning electron microscopy has been extensively used for the material characterization of objects of artistic and archaeological importance, especially in combination with energy dispersive X-ray microanalysis (SEM/EDX). The advantages and limitations of SEM/EDX are presented in a few case studies: analysis of pigments in cross-sections of paint layers, quantitative analysis of archaeological glass from the Roman period excavated in Ephesos/Turkey, and investigations on glasses with medieval composition concerning their weathering stability and degradation phenomena.