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1.
An investigation has been undertaken at St Andrew’s church, Walpole St Andrew, Norfolk, to establish the underlying causes of the observed stone decay to the upper parts of the six stone piers. The stone decay was first recorded in the early 1930s. The salt-contaminated masonry within the church has been shown to undergo severe salt decay during the summer, with little damage occurring over the winter months. The south aisle piers have been shown to decay 2.5 times faster than the north aisle piers. Although crystallization–hydration cycles have been identified, the rate of decay is at its greatest when the cycling is relatively infrequent. This was not the expected trend. Furthermore, it has been shown that during extended periods where the ambient relative humidity is less than 75%, the rate of decay reaches a maximum. It is the length of this ‘drying’ period that apparently has the greatest influence on the rate of decay and could explain the significant difference in the rate of decay between the south and north aisle piers. The results have serious implications for passive conservation, where it is often recommended to lower the ambient relative humidity to well below the equilibrium relative humidity of the salt contaminant, to avoid crystallization–hydration cycles. Since, at the time of building, the church was situated on the coast, it is possible that the sodium chloride contamination occurred during the building process (1440–1520), particularly since the area was prone to sea-flooding at this time. Alternatively, the salt could have been applied as a treatment during the general restoration of 1897. Whatever the source of the salt, it seems likely that the ambient environment was changed by the insertion of a sealed floor in 1897, which could account for the onset of the salt decay.  相似文献   

2.
This study shows that the sandstone used in the construction of the Church of San Mateo in Tarifa (Cádiz, Spain) is highly sensitive to processes of decay because of a combination of factors that are intrinsic and extrinsic to the material. The mineralogy, texture and porous system of the sandstone and the proximity of the church to the sea all play a part in these processes. X-ray diffraction reveals that there are interstratified chlorite/smectite clays among the minerals that make up the rock. These mixed layer clays have been shown to undergo hydric expansion. This phenomenon may be accompanied and augmented by the presence of NaCl which acts as an electrolyte in osmotic swelling processes. Two varieties of sandstone were used in the construction of the church, namely grey sandstone and brown sandstone. The latter is more porous and undergoes greater hydric expansion, showing a higher degree of deterioration. Ultrasound analysis has demonstrated that both varieties are anisotropic because they contain bedding planes and are affected by the preferred orientation of the phyllosilicates in the rock. The anisotropic nature of these stones was confirmed by capillary suction tests. The capillary front reaches a relatively low height which means that when water is absorbed, the anisotropic textural properties combined with the presence of chlorite–smectite mixed layers in the sandstone result in mechanical (shear) stress between the first few centimetres of the wet stone and the dry area behind. The latter effect favours the development of flakes, so causing the decay of the ornamental stone and the church façade.  相似文献   

3.
We address the question of the quality of movies produced between 1950 and 1970. A first outcome of our analysis is that the quality assessments made during the Cannes Festival, and to a lesser degree, by the U.S. Academy are short-lasting. In contrast to this, consumers seem consistent over time. There is, however, one issue on which experts agree as well as consumers: American movies dominate both in terms of commercial success and in terms of quality. There is less agreement, and sometimes there is even dissent concerning other dimensions. This does not come as a surprise and merely indicates that there is hardly a common yardstick along which the quality of a movie can be measured. Therefore, decomposing a work of art into quantifiable characteristics – even in a subjective but possibly unanimous way – would make it possible to explain the divergences between audiences and changes of appreciation over time.  相似文献   

4.
The utilization of laser light to produce fine and selective cleaning of superficial deposits and encrustation from stones was originally proposed more than 20 years ago by John Asmus who performed pioneering trials of laser cleaning on stone façades in Venice, Cremona and Padua. The opportunity to collect stone samples from these sites allowed us to carry out an original study aimed at evaluating the conservation state of stone surfaces cleaned 10–20 years ago by means of three different techniques: Nd:YAG laser radiation, micron sandblasting and chemical pads. Samples of various stone types, as Istria limestone, Botticino limestone and Nanto sandstone were collected and examined by means of optical and SEM microscopy, FT/IR, and EDAX analyses. The results provided preliminary indications that the state of conservation of stone surfaces previously subjected to laser cleaning is generally better in comparison with those which concurrently underwent mechanical and chemical cleaning.  相似文献   

5.
A life-size whitish marble statue of a “Virgin with Child” has been recently rediscovered in the St. Rosario church located in Ottaviano, a small town near Naples (southern Italy). This artwork shows stylistic features of the Tuscan-Roman school of the 16th century, and is framed in an intriguing historical context. Historical documents testify that the sculpture was a property of the cadet branch of noble Tuscan family of the Medici, the Medici of Ottaviano. A multianalytical approach has been used to try to indicate the supply area of the white marble of the studied sculpture. Considering the whole mineralogical, petrographic and geochemical data, the source rock can be possibly limited to the main classical white marbles of the Mediterranean district, as the classical marble of Aphrodisias. A reuse practice of a former artwork can be also hypothesized.  相似文献   

6.
基于历史档案资料,追述了伦敦大火后英国圣保罗大教堂重建时期石材采运的历史,揭示了各类石材的开采与运输方式、建造中引发的问题,并首次对石材的供应情况进行了定量分析,呈现了石材采运如何成为圣保罗大教堂的重建历时35年之久的主要原因之一。圣保罗大教堂的石材采运问题并非独特案例,同类型的石材在同时期其他建筑中曾被广泛运用,因此对研究那个时代的砖石建筑具有更普遍的参考意义。  相似文献   

7.
The presence of a diffuse biodeterioration phenomena can be observed across large areas of the outer surface of the limestone walls of the Church of the Virgin in Martvili. A differential erosion phenomenon was detected, suggesting a possible association with biological colonization. The erosion phenomenon is characterized by a circular discoloration leading progressively to the detachment of flakes of limestone at its center. Since the aforementioned process has not been described in the literature until now, the present study was focused on the interpretation of its origin and evolution. Three sides of the Church are affected by a variety of occurrences of circular differential erosion which display different stages of the process, whereas the western side is affected by epilithic growths across its entire surface. Surveys of the petrographic, mineralogical and physical features of the stone were made, and parameters such as density and porosity were recorded. Samples were analyzed by optical microscopy and SEM analysis in order to detected the presence of microorganisms whose species were then identified by means of morphological and molecular examinations. The study of cross-sections stained using the PAS method has confirmed the causal connection between microorganisms and the deterioration phenomena, providing information about their spread of penetration into the substrate and their substantial potential for causing damage. Dryness appears to be the main ecological condition favoring endolithic rather than epilithic growth. The most common isolated microorganisms were cyanobacteria (Chroococcales) and, to a lesser extent, meristematic fungi. The characteristics of the stone, and especially some endogenous discontinuities related to the accumulation of sedimentary layers and to the action of stone carving tools, might explain why the same differential erosion phenomenon occurs in specific areas of the block stones. The development of the differential erosion phenomenon shows a variety of stages of biological colonization. The progressive evolution of the deterioration process has been observed in detail: (a) firstly, white circular discolorations appear on the stone, which darken over time eventually becoming almost black; (b) circular perforations appear around the perimeter; (c) and finally a flake detaches from the center, leaving a deep depression in the stone.  相似文献   

8.
This article analyses the economic dimension of a set of activities groupedunder the heading, Culture and Leisure Industry, from three complementaryperspectives: national (Spain), sectoral and regional. Particular emphasis isplaced on determining the value added generated by this industry and itscontribution to the Gross Domestic Product – 4.5% – as wellas showing its level of employment both in absolute terms and as a percentageof the number of employees in the economy – 7.8%. This is apioneer project; studies in this field on either a national or internationalscale are scarce. The study demonstrates that the cultural sector is aproductive activity generating wealth in Spain. However, a high degree ofheterogeneity is found at both the sectoral and regional levels. Economicactivity is led by Performing, Musical and Audiovisual Arts (mainlyTelevision) and Publishing and Printing, which jointly account for about70% of sales and gross value added, and it is concentrated in similarproportions in developed regions specialized in service industries, Madrid andCatalonia, where most culture and leisure activities are available.  相似文献   

9.
The binding media of the polychromy of Qin Shihuang's Terracotta Army   总被引：2，自引：0，他引：2  
The “Terracotta Army” is a worldwide known archaeological finding in China. It is a part of the burial complex of the emperor Qin Shihuangdi (259–210 BC), which is still under excavation and study. The fact that the sculptures, chariots and weapons of the First Chinese Emperor's Terracotta Army were originally all painted in bright colours is still not widely known. The chemical characterisation of the paint medium was performed through an analytical procedure based on GC-MS. The proteinaceous binder was identified for the first time through a desalting procedure used in proteomics. The identification of egg as a paint binder is extremely interesting in terms of the historical significance of the work of art itself and important in terms of the method of conservation. Moreover it represents one of the first steps towards an understanding of the painting technique used on ancient sculptures in China, of which – despite their fame – nothing is yet known.  相似文献   

10.
The funeral monument of Maarten Tromp, in the Old Church of Delft (the Netherlands), is partially built with Tournai stone, a grey-blackish limestone from the Wallonia region (Belgium). This stone is suffering a severe delamination and scaling, which has, in the course of the centuries, led to a considerable material loss from the surface of some of the stone elements. In order to identify the damage process and define a sound basis for the conservation of the monument, a research plan was set-up including, next to the tests and analyses on the stone, a 1-year monitoring of the microclimate in the church and the investigation of the structure of the monument as well as its connections to the adjacent walls. First of all, the stone type was identified by macroscopic features and by thin section microscopy. The moisture distribution in the monument and in the adjacent walls was gravimetrically determined on samples taken at different height and depths. The content and type of salt in the Tournai stone from the monument were determined by X-ray diffraction and ion chromatography, and the results compared to those obtained for the fresh stone. The analyses showed the presence of considerable amount of gypsum, together with a low content of soluble salts (chlorides and nitrates). The SEM-EDS observations showed that gypsum is mainly crystallizing in cracks between the layers of the material. The damage mechanism and the influence of salt on the decay were further investigated by combining hygroscopic moisture uptake, hygric dilation (RH cycles between 50% and 95% RH) measurements and SEM-EDS observations; all measurements were performed both on stone sampled from the monument and, as comparison, on fresh stone specimens. The results show that gypsum is the main salt present, but its role in the damage is not significant. The naturally thin laminated structure of the stone together with the considerable hygric dilation seem to be the main causes of the delamination observed in this stone.  相似文献   

11.
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12.
The work is focused on identification of lead tin yellow types I and II, Naples yellow, and also on discrimination of a less common, distinct yellow pigment, the ternary Pb-Sb-Sn oxide.The knowledge about all those Pb-based yellows was in fact forgotten after introduction of modern synthetic yellows in 19th century. As late as in the last decade of the 20th century, the existence of Pb-Sb-Sn yellow and its production have been rediscovered, and only then it has been identified in colour layer of artworks.Pb-Sb-Sn yellow has recently been identified in colour layer of 17th century Italian paintings by Sandalinas and Ruiz-Moreno [C. Sandalinas, S. Ruiz-Moreno, Lead tin-antimony yellow, historical manufacture, molecular characterization and identification in seventeenth-century Italian paintings, Stud. Conserv. 49 (2003) 41–52], and here we report the finding of this pigment in Mid-European painting of the 18th and 19th centuries. Lead tin yellows, lead antimony yellow (Naples yellow), and lead antimony tin yellow were synthesized in laboratory following historical recipes, their colour was analyzed, and their structure was confirmed to provide a basis for their routine identification in microsamples of artworks by X-ray microdiffraction. Unequivocal identification of Pb-based yellows could help in authentication of traditional European paintings, because their use was temporally and also geographically specific. Combination of elemental microanalysis (X-ray fluorescence electron microanalysis) and X-ray powder microdiffraction were found very efficient in the microanalysis of colour layers of artworks with Pb-based yellows and their unequivocal identification.  相似文献   

13.
The penetration of water in rock materials is the main cause of deterioration of stone surfaces exposed to rainfall. Their protection is generally achieved using water-repellents, in order to reduce the absorption of water. Nuclear Magnetic Resonance Imaging (MRI) provides a new tool to visualize the presence of water inside the stone and, hence, the performance of hydrophobic treatments. This technique can also give indirect information on the distribution of the hydrophobic product inside the rock.  相似文献   

14.
The aim of the paper is twofold: to report on theapplication of a contingent valuation survey todetermine the value to the Naples population ofmaintaining ``Napoli Musei Aperti', a cultural publicgood provided by the city of Naples, and to exploresome alternative schemes of cultural policy. The paperis divided in two parts. The first presents someresults of the contingent valuation study. The seconddiscusses the use of the contingent valuation as apolicy instrument in the public cultural sector.  相似文献   

15.
Mackie  Robin 《Minerva》2000,38(2):171-199
This paper examines the membership of the professionalassociation of chemical engineering in Britain – the Institutionof Chemical Engineers – during its first three decades. Usingcollective methods of biography, it explores how long it took forclear boundaries to develop between this membership and the widerchemical community. Delineation was linked to the development ofan academic discipline. This paper argues that the indeterminateconstituency of the IChemE delayed growth, but allowed it to playa key role in shaping the development of the new profession.  相似文献   

16.
In a parallel study, it has been shown by comparison of successive TV-holography campaigns that murals in the convent of Müstair (Switzerland) have progressively detached from their substrate over a time interval of 5 years (J Cult Herit 2009). Here, we focus on the dynamics of the ongoing detachment processes. In order to regularly measure small surface displacements in situ over a long duration of several years, a new method that we call Mirror Micrometry (MM) has been designed and implemented. This method monitors the reflection of a light beam by a mirror that is mounted to the surface of interest for the duration of the experiment. The mirror is designed to rotate about a pivot as small displacements in the detaching surface occur, thus deflecting the reflected light beam. Measurements over more than three years in the Convent Church and in the Holy Cross Chapel reveal various types of surface displacement perpendicular to the wall surface. These are correlated with relative humidity (RH) changes in the room climate. Reversible short-term variations of approximately ±5–10 μm occur with periods of one to several weeks and relate primarily to weather changes. Reversible long-term variations of ±5–10 μm correspond to averaged seasonal humidity changes. Irregular and irreversible movements in increments of 20–30 μm record very localised progressive detachment steps. A semi-quantitative correlation of approximately 1 μm surface displacement per 1% RH change is calculated. Based on the fact that nearby measuring points can simultaneously move in opposite directions, a geometric model is drawn to explain deformation by hygric swelling and shrinking of different shapes of detached layers.  相似文献   

17.
Giovanni Fattori (Livorno 1825–Firenze 1908) is the most representative artist of the Macchiaioli's current, an early group of Italian plein-air artists, whose work anticipates, in the xixth century, that of their younger contemporaries, the French Impressionists. The study, performed by a multidisciplinary team made up of scientists and conservators, presents the results of the scientific characterization carried out on a group of 10 paintings made by Fattori between 1854 and 1893 and shows the way he used complex mixtures of a large variety of traditional and synthetic pigments, ranging from lead white, found pure and also extended with calcium carbonate, natural barite and gypsum to zinc white, from red ochre to cinnabar and vermilion, from yellow ochre and Naples yellow to chrome yellow, cadmium yellow and zinc yellow, combined with many other ones reported in details. This paper highlights the evolution of his painting technique during a time of great technological and social innovations and puts forward some hypothesis on his awareness about manufactured pigments, i.e. tube paints recently introduced into the artists’ circles. The wide range of pigments and their different quality among the same synthetic products suggest that the artist used all the available materials, and that picking out the pigments he retained the early xixth century artists techniques, such as the use of mineral earths and Prussian blue, similarly to his contemporary Italian artists Federico Zandomeneghi and Telemaco Signorini, but he also experimented new and peculiar pigment mixtures in the making of “colored darks” and an innovative use of the grounds in the final composition, that are also distinctive features of the French Impressionists. This work is aimed at contributing to overcome the lack of a comprehensive overview on the widespread historical and scientific data collected up to now on the Italian paintings in the xixth century, which has been severely underestimated with respect to previous art movements.  相似文献   

18.
The preservation of historical monuments requires both a detailed understanding of water circulation inside construction materials, and a deep comprehension of the associated physical and chemical effects on building structure. Combining mass and temperature measurements may be a new powerful tool to achieve this purpose, as first results obtained on a wall of the Saint-Gatien cathedral in Tours, France, indicate. The proposed method has been evaluated with dedicated experiments in a climatic chamber, regulated in both temperature and humidity, using three types of stones: Tours tuffeau, Baumberg limy sandstone, and Rüthen sandstone. Climatic chamber data indicate that temperature gradients between rock surface and atmosphere provide a meaningful and practical estimate of the water flow, which controls the heat exchange between rock and atmosphere because of the high enthalpy of vaporisation of water. Continuous measurements of the mass of a sample confirm this assumption and allow the calibration of temperature data with respect to water flow estimations. Temperature gradients between points on the stone surface are also dominated by changes in the water flux, and they provide a sensitive estimate of local variations in the heat and water transport properties of non-saturated stones. Combined mass and temperature measurements therefore appear as a promising method to estimate in situ the global and local water flow between the rock and the atmosphere and thus to diagnose the state of stone degradation, or to estimate quantitatively the efficiency of treatment processes, both in the field and in the laboratory.  相似文献   

19.
Along the Umbria-Marche stretch of the Flaminia Consular Road (220 B.C.) several archaeological finds of the most important monumental works, are well preserved. The stones, employed to build many bridges, substructions and sewerages, are represented by carbonatic breccias whose geological environment of formation and source areas had never been established. On the basis of mineralogical, petrographic and micropalaeontological analyses, two groups of these lithotypes employed in Roman age were distinguished: “monogenic carbonatic breccias” only constituted by clasts of the Maiolica Unit (Late Jurassic – Early Cretaceous) and “polygenic carbonatic breccias” made of fragments (in different proportions) of Calcare Massiccio (Early Jurassic), Corniola (Early Jurassic), Maiolica (Late Jurassic – Early Cretaceous) and Scaglia Rossa (Late Cretaceous – Early Paleogene) Units. The possible source areas of the breccias are compatible with stratified slope-waste to scarp-base deposits of periglacial origin belonging to the Upper Pleistocene. In particular, among the seven investigated areas, we pointed out the most probable provenances (Monte Faeto-Colle, Costacciaro, Scirca, Foci, Secchiano) along the flanks of the Apennine Mesozoic chain of the Umbria and Marche regions. Although the Romans could have exploited the whole thickness of some outcrops (now disappeared) of these carbonatic lithotypes at the deepest part of the valleys, we have constrained a local provenance of the breccias so commonly used in the monumental works of the Flaminia.  相似文献   

20.
This paper takes a preliminary look at the hybridization of museums – the creation of a variety of mixed forms of governance incorporating both public and private governing authorities. Using data from three national surveys of American museums, the analysis documents the mix of types of governing authority and demonstrates how this mix varies across location, over time, and by museum type. The paper then estimates the extent of hybridization using several different indicators and speculates about its implications. The United States offers a particularly informative case because the general view is that American museums are (1) either public or private and (2) predominately private. While the second part of this view may still be a useful characterization of American museums, the first is no longer a particularly helpful way of understanding American museums, or, by extension, other cultural institutions, American or not. It is increasingly necessary to view cultural institutions through the lens of hybridization rather than privatization in order to improve our ability to document and predict their institutional behavior.  相似文献   

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