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1.
A medieval wooden panel chamber was rediscovered during reconstruction of the Tetzelhouse in the Saxon town of Pirna. Ceiling and walls are made from 600-year-old fire wood panels fitted together. The complete removal of layers (limewash, plaster, glue and dirt) from the wall panels was the precondition for conservation of the wood panels and for the restoration of the wooden panel chamber. The cleaning was carried out with a pulsed Nd:YAG laser after basic investigation of ablation mechanisms of the layers on the old wood. All layers of the different materials were removed both from the normal surface and out of depressions and woodworm holes with a special range of laser parameters, without damaging the wood. Within this range of parameters the laser cleaning is a self-limiting process. The health hazard from emitted waste products were determined and checked with work place measurements. The laser cleaning of the wooden wall panels was completed in March 1999. A uniform visual impression of all panels was obtained with a warm wooden colour tone.  相似文献   

2.
Stained glass windows belong to the most precious pieces of art in many European countries. Examples of heavily endangered paint on glass are reported in the literature and mainly related to condensation effects and air pollution, as stained glass windows preferably remain in their original architectural surrounding. Several surface coatings and paint treatments have been proposed to consolidate and protect degraded paint. Very often, the selection of the materials is based more on practical aspects than on scientific research. This study concerns the comparison of some traditional, modern and newly developed consolidants for the preservation of historic glass paintings. Experiments have been carried out with model painted glass samples simulating weathering phenomena of originals. Traditional materials like Paraloid B72, modern ones like SZA (proposed by the Fraunhofer-Institut für Silicatforschung, ISC), and three new consolidants prepared by the sol–gel method and based on different hybrid organic–inorganic alkyl-alkoxysilane systems have been considered. The adhesion, penetration, stability, hydrophobicity, mechanical and chemical resistance are properties and requirements tested to prove their effectiveness and range of use. The three new materials developed in this study for the consolidation of paint on glass have the potential to offer alternatives to existing materials. Nevertheless, further research is necessary before their application in restoration workshops can be recommended. A strategic approach is requested to avoid risks for these valuable historical originals and to contribute to the long-term preservation of the paint on stained glass windows in their original sites.  相似文献   

3.
The methodology of protecting the European stained glass windows against environmental risk (e.g. meteorological factors, air pollution, microorganisms) by means of an external glazing is not new. In spite of many scientific studies carried out in the last 20 years, some questions were still up for discussion. The European VIDRIO (2002–2005) project gave an answer to these questions. The research carried out by the different project partners established a new multidisciplinary approach aimed at evaluating the efficiency of the protective glazing systems and their effects on stained glass windows conservation, and finally at assessing the most appropriate strategy to preserve stained glass windows. Scientific results showed that the so-called isothermal glazing (i.e. ventilation by the air coming from the inside of the building) protected efficiently the ancient stained glass window from environmental attack (i.e. rain, pollutants, condensation, thermal shocks) with very limited secondary effects. The scientific research highlighted that its efficiency was strongly related to the technical design of the protective system. In particular, the ventilation and the size of the interspace had to be carefully considered. The research developed within the VIDRIO project was turned into general recommendations to the owners and practitioners on the best practice for the stained glass windows future conservation.  相似文献   

4.
This paper reports results derived from a chemico-physical characterisation study undertaken on an important ensamble of early 20th century stained glass windows from Madrid and signed by the prestigious and well-known Maumejean Fréres company. The study is part of an on-going project of restoration and conservation carried out by the National Glass Centre Foundation (FCNV, La Granja de San Ildefonso, Segovia, Spain). The basic aim of the research was to assess their current state of conservation and to study the degree of damage suffered throughout the last century by different materials employed in their production, namely colourless and coloured glasses, grisailles, lead cames, and putties used to fix glass pieces into the lead cames. Selected samples from these materials were characterised through optical microscopy (OM), X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDX), VIS spectrophotometry, and X-ray diffraction (XRD). As a general rule, most of them presented an acceptable state of conservation, without any of the known degradation phenomena of more ancient stained glasses (e.g. Medieval, Renaissance, etc.). However, some remarkable alterations were observed. Important deposits of soot and dirt particles coming from a polluted urban environment were detected, producing a slow blackening of the panels. Resulting data have been useful to design and optimise a combined conservation and restoration strategy in the recovery of this valuable legacy of early 20th century stained glass windows from Madrid.  相似文献   

5.
The analysis of environmental risk in historical cities facilitates the development of conservation strategies that can minimize the deterioration of historical heritage sites. Risk maps built with GIS software provide information about the probability of the main hazards in a region, and is a very useful tool to identify, evaluate and prioritize the restoration budget of a city in order to manage preventive conservation. In this paper, new methodologies are applied based on the vulnerability matrix and its relationship with static and structural factors, climate conditions, air quality and social agents. This technique has some obvious advantages in the application of risk analysis for cultural heritage conservation, such as the capability of simultaneous risk assessment and geographical references. The vulnerability study implies an on-site diagnosis analysis and requires an adapted protocol for archaeological heritage. The validation of this methodology was carried out in the historical town of Merida (Spain) with a GIS application (ArcGIS software), where the main monuments of this UNESCO World Heritage site were studied.  相似文献   

6.
The survey of materials constituting the buildings of the ancient city centre of Naples and of their decay typologies was carried out. Reports were entered in a database which enabled us to draw two thematic maps in a digital format: one of materials and lithotypes, and one showing weathering. On this basis, quantitative evaluations of the lithotypes were carried out. The research pointed out that the use of different lithotypes was mainly as a result of their availability and/or ease of exploitation. Furthermore, the importance of the preservation of the quarrying sites was stressed, both for their historical and cultural interest and, above all, for possible forthcoming provisioning finalized to restorations. The analysis of the results, made on a geo-mineralogical basis, as well as the thematic maps, gives a basic tool which will be very useful to those professionals involved in preservation of cultural heritage.  相似文献   

7.
The development of laser cleaning as a conservation treatment has imposed a need for the evaluation and assessment of other cleaning techniques. The use of more traditional methods like abrasive cleaning, steam cleaning and chemical cleaning has relied so far on visual assessment, unlike much of the research applied to laser cleaning. A conscientious use of these cleaning methods requires their assessment as well as the need for a comparison based on a common methodology. A topographical assessment of laser cleaning, abrasive cleaning, steam cleaning and chemical cleaning (using hydrofluoric acid, ammonium carbonate and EDTA) is presented. Topographical variations induced on marble, oolitic limestone and architectural terracotta surfaces are assessed by means of light interferometry, showing the potential of this non-contact and non-destructive technique for surface studies in conservation. The comparison between cleaning treatments is based upon key parameters associated with cleaning surfaces. The aesthetic impact of these treatments is verified by means of optical microscopy and quantified by colour measurement. Chemical analysis of the cleaned surface (EDS) is performed to investigate the removal of surface pollutants and the presence of residues. Finally, petrographical analysis was used to investigate the removal of pollutant layers and its effect on surface texture.  相似文献   

8.
The development and application of self-cleaning treatments on historical and architectural stone surfaces could be a significant improvement in conservation, protection and maintenance of Cultural Heritage. In this paper, a TiO2-based coating has been investigated in order to evaluate its possible use as a self-cleaning treatment. This coating was obtained by a sol-gel and a hydrothermal (134 °C) processes and then it was applied on travertine (a limestone often used in historical and monumental buildings) in two ways, obtaining a single-layer and a three-layer treatment, respectively. In order to verify its potential use in the field of Cultural Heritage, the maintenance of appearance properties of the treated travertine surfaces was monitored by colour and gloss analyses. Besides, de-pollution and soiling removal tests were carried out under ultraviolet-light exposure to evaluate photo-induced effects and self-cleaning efficiency. Results seem to allow the use of TiO2-based treatments on historical and architectural surfaces made up by travertine, where de-pollution and self-cleaning photo-induced effects are well evident, maintaining their original visual appearance. Anyway, before applying TiO2-based coatings as conservative treatments, further tests are needed especially on their durability, that is mandatory for Cultural Heritage applications. On-site test in an urban environment and accelerated test by weatherometer are currently under way.  相似文献   

9.
Microbial corrosion of glass causes problems on delicates antique glass samples. Until now, the effect of microbial activity on corrosion phenomena has not been well documented. Only a few studies have been published concerning the microflora growing on glass surfaces.The present study deals with the characterization of cultivable aerobic bacteria isolated from the historical glass window “Natività” in the Florence Cathedral, designed by Paolo Uccello and realized by Angelo Lippi between 1443 and 1444. Microbial strains were sampled from four of the 25 panels of the “Natività” in the occasion of a recent conservation treatment, due to the presence of various kinds of crusts. One hundred microorganisms were isolated, about 50% bacteria and 50% fungi. Bacteria were submitted to morphological characterization and classified in the Gram group. For twenty strains, from different glass panels, the 16S rDNA gene was amplified and sequenced. Sequence analysis showed genus Bacillus, Arthrobacter and Paenibacillus as the most representative. In particular Bacillus and Paenibacillus are crusts associated. Phylogenetic relationship among isolates was determined. Chemical analysis of the glass and crusts completed the study.  相似文献   

10.
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11.
The sculptural polychromy in the Zhongshan Grottoes, sited in northwest China, has been investigated in terms of chemical composition of employed materials and pigments, state of conservation and painting technique. Raman analysis, Fourier-transform infrared analysis, analysis through energy-dispersive X-ray spectrometry coupled to scanning electron microscopy and pyrolysis coupled to gas chromatography and mass spectrometry were applied. Six analyzed samples showed silicates and kaolin as main components of the ground layers. Also lead white has been found in these layers. Minium, red-earth and mercury sulfide are the red pigments detected in the polychromy. A mixed use of malachite and atacamite has been detected in three green samples. Optical characteristics of atacamite and malachite found in the samples indicate a synthetic origin. The presence of a synthetic organic pigment such as phthalocyanine chlorinated pigment was also revealed. Ultramarine blue pigment, obtained by purification of lapis lazuli, has been detected in the blue sample. As for the binders used, fatty materials and siccative oil were found.  相似文献   

12.
The application of lasers for the removal of superficial deposits from historic stained glass is a comparatively new field of scientific interest. Experimental studies concerning the behaviour of glass substrates and the corresponding superficial deposits towards different laser wavelengths were carried out. The experiments were performed using wavelengths of λ = 193 nm (ArF-Excimer), 308 nm (XeCl-Excimer), 355 nm (Nd:YAG third harmonic) and 1 064 nm (Nd:YAG fundamental) in comparison to λ = 248 nm (KrF-Excimer). This comparison is due to the fact that the present knowledge is based on the 248 nm wavelength. Specially prepared model glass samples representing the original fragments and samples of organic polymers (formerly used as a protective material for historic stained glasses) were used to study the effects of laser radiation and were subsequently characterised by optical microscopy.  相似文献   

13.
To assess the possible effects of mechanical loading on the conservation of historical wooden musical instruments, a research project was carried out on the violin Guarneri “del Gesù” (1743), known as the “Cannone”. This paper refers to the results obtained by studying the deformations to which a violin is subjected after being tuned, with special attention to the viscous and mechano-sorptive behaviour (as in a concert environment for example). The amount of viscoelastic creep was quantified under normal tuning conditions, and the mechano-sorptive creep was quantified using a dead mass resulting in 55% of the elastic deformation obtained after tuning. The viscoelastic and mechano-sorptive deformations were clearly observed. These deformations were completely recovered once the violin was unloaded, demonstrating that this violin structure is appropriately dimensioned for the applied stresses.  相似文献   

14.
The preservation of early 20th century, late 19th century albumen prints is of great concern to collection managers and conservators of photographic materials. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopic imaging is presented for the first time as analytical methodology for the study of albumen photographs. This paper shows the feasibility of obtaining FTIR images of samples from albumen photographs with a high spatial resolution using a Ge ATR objective coupled with an infrared microscope. The improved spatial resolution compared to FTIR images obtained by the reflection method is due to the high refractive index of the ATR crystal, which gives a high numerical aperture and hence, a higher spatial resolution. The technique reveals detailed information on the organic functional group distribution in the individual layers of embedded cross sections and is used complementary to visual microscopy and scanning electron microscopy/energy dispersed X-ray spectroscopy. The main results of the study are discussed with regard to their historical and artistic significance, and they are compared with data from historical and conservation literature.  相似文献   

15.
The present study dealt with the characterisation of marble surfaces coated by three kinds of polymeric material usually employed in stones conservation and with the evaluation of the removal of these coatings from the surfaces by means of new nanocontainer aqueous systems constituted of micellar solutions (MS) and oil-in-water microemulsions (MC). The polymeric coatings were also subjected to accelerated artificial ageing in order to detect possible effects associated to natural photochemical ageing. The aim of the work was the assessment of the performance of such nanocontainer aqueous systems taking acetone (Ac) as a reference “traditional” solvent for the removal procedure. The characterisation was carried out by means of Scanning Electron Microscopy (SEM) and Environmental Scanning Electron Microscopy (ESEM), Fourier Transform Infra-Red (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies and the results obtained showed that the performance of these innovative methods based on nanocontainer aqueous systems can be considered highly promising in the view of a “green approach” to the conservation of cultural heritage.  相似文献   

16.
During the restoration plan of the famous painting “Madonna col Bambino e S. Giovannino” by Sandro Botticelli, located in the Museo Civico of Piacenza (Italy), a study on painting materials was carried out. The pigments, the binders and the materials used for the application of ground and priming layers were studied using micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry (GC/MS), optical and electronic microscopies. Gypsum and anhydrite were found in the ground layer, while carbon black and lead white were used in the priming layers. The precious pigments of the artist's palette and the binders used (egg and animal glue) were determined.  相似文献   

17.
On-line monitoring or even closed-loop control is necessary to avoid over-cleaning in case the ablation process is not self-limiting. Therefore, the laser-induced breakdown spectroscopy (LIBS) was used. Basic investigations were carried out on original sandstone samples (Elbsandstein) with strong encrustations as well as medieval stained glass samples (13th century from Cologne Cathedral). The spectroscopic study has shown that the plasma emission can be used for determination of the elemental composition of the ablated material. The plasma was initiated by 248-nm pulses of an KrF-excimer laser (30 ns FWHM). For the spectroscopic analysis, a grating spectrograph in combination with an optical multichannel analyser was used. For the glass and stone samples we obtained a continual alteration of the LIBS spectrum (vanishing of peaks and generating of new element peaks) during the removal process. Thus, certain element peaks can be used to distinguish between encrustation layer and valuable underlying material. To show the potential of LIBS we designed an experimental laser cleaning set-up including closed-loop LIBS control and demonstrated successful automatic cleaning of an original glass fragment.  相似文献   

18.
Epoxy resins, widely used in conservation, still remain controversial materials. Considering some of the drawbacks that currently limit the application of epoxy consolidants, we present the application of the cationic ring opening polymerization as a novel method to cure the epoxy monomer in the restoration field. The cationic polymerization was carried out through a redox system based on the reduction of the iodonium salt in the presence of ascorbic acid catalyzed by a copper salt. The use of this initiator system for carrying out a suitable consolidant for lime plaster is considered. First, the film properties of the cured films were investigated. Then, the formulation was applied on a sample of plaster and its compatibility was verified. Its effectiveness as a consolidant product is explored through the evaluation of chromatic changes, mechanical strength, morphology of the re-aggregated material, and changes of the surface properties.  相似文献   

19.
The ablation of biofilms by excimer laser radiation was systematically examined in a series of model studies during which the biofilms originating from different historical panels were simulated on model glasses. The composition of these model glasses was modelled on that of the original historical glasses. Our studies have shown that glass composition, climatic conditions and biofilm formation are factors which interact synergetically. It could be observed that various biofilms grow differently on the same type of model glass and that the same type of biofilm shows a different development on various model glasses. The decisive factors for the effectiveness of biofilm ablation by laser irradiation is the formation of the biofilm on the one hand and its corrosive potential on account of its ability to accumulate moisture and to produce glass-damaging metabolites on the other. Glasses of low chemical stability promote the growth of dense biofilms and can be cleaned only with a high energy density, whereas glasses of high chemical stability merely allow for a slow growth of a biofilm spreading two-dimensionally on the glass surface which can be gently removed using low energy density.  相似文献   

20.
A collaborative project between the Materials Department of Imperial College, the Victoria & Albert Museum, Natural History Museum and the Tate Gallery was initiated with the objective of introducing laser cleaning in these London-based museums and establishing a long-term research collaboration. An access to these material conservation departments means that materials like traditional statuary materials, heavily corroded metals, ivory, palaeontological samples, textiles, stained glass, plaster and some modern materials can be used to investigate the usefulness of laser cleaning and study their effects using a wide range of analytical techniques.  相似文献   

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