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1.
ABSTRACT

The preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many studies have been carried out on the best way to control hygrothermal conditions. In old buildings located in maritime temperate climate zones (such as Portugal) with strong thermal inertia, and which have low ventilation rate (relative to the volume and number of visitors), daily and seasonal hygroscopic inertia may help to assure the maintenance of RH stabilization conditions. The use of expensive active systems may be minimized through the passive behaviour of internal finishing building materials. This work presents the results of an experimental laboratory study conducted in a flow chamber to demonstrate the enormous potential of hygroscopic materials in stabilizing interior relative humidity. Based in these results and in-situ monitoring in a museum housed in a building, located in Porto, with a typical construction of the 1950s (granite masonry and reinforced concrete slabs), a numerical analysis was done to quantify the influence of hygroscopic materials in stabilizing the interior relative humidity.  相似文献   

2.
The construction and examination of test panels is an ad hoc procedure, necessary for every spectral imaging study of paintings. Despite the common features, almost every scientific team follows a different way of construction. Furthermore, many of these approaches are not adequately documented in the relevant papers. Failure to use common language and practice leads to confusion about properties of materials and paint layers that have been overall examined by the scientists, as well as the validity of the results and their exploitation in several conservation applications. The present theoretical approach points out the need for common protocols for the construction of test panels and draws general principles as a flow chart on which they should be based.  相似文献   

3.
Currently, about ten Goryeo dynasty (918–1392 CE) sutra boxes are preserved in museums in Korea, Japan, the United States, the Netherlands, and the United Kingdom. This article is the result of an examination of a sutra box in the collection of the Rijksmuseum, Amsterdam (hereafter ‘Rijksmuseum sutra box’), which was first introduced to a European audience in the Transactions and Proceedings of the Japanese Society, in 1913–1914. The Rijksmuseum sutra box differs from other Goryeo sutra boxes. With its altered structure and modified motifs, this box bears significant value, not only for the research of thirteenth-century Goryeo mother-of-pearl art, but also for the study of cross-cultural adaptations in East Asian lacquer art. This article investigates the date of manufacture of the sutra box by analysing the manufacturing techniques and its various original and modified parts. For this, an X-ray radiograph was carried out for the first time. As a result, discoveries have been made regarding the structure and decoration of the lower part, which has been modified and is different from Goryeo mother-of-pearl sutra boxes. Finally, this paper reconsiders conservation and repair of Goryeo sutra boxes, as illuminated by an understanding of the original and repaired parts of this box.  相似文献   

4.
ABSTRACT

The first step in preservative measures for artworks in airtight showcases is the exclusion of outgassing from construction materials or, at least, limitation of the emissions to a minimum acceptable level if the volatile organic compounds (VOCs) generated may be qualified as harmless. Once it is ascertained that the objects in the showcases are responsible for VOC emissions, a step forward becomes necessary, implying showcase ventilation with air flowing through active sorbent materials. Solid phase micro-extraction (SPME) followed by GC separation and MS identification has been applied for checking the outgassing characteristics of different types of materials used for the construction of airtight showcases, and the method was found particularly attractive in terms of speed and sensitivity, suitable for measurements in presence of low-emitting materials. Sampling could also be done in the case interiors, thus making possible detection and recognition of emissions from art objects within a case. A comprehensive preventive conservation scheme has been further devised by means of active air circulation within the showcase and functional sorbent materials along the flow, for complete suppression of gaseous compounds. Control of the compounds in the air flow and of their filtration efficacy was achieved by direct sampling, also using SPME fibers. Continuous monitoring of the air quality in the showcases has been developed with insertion of a photoionization detector capable of detecting the VOCs in the air by inducing molecular ionization, and measuring the generated photocurrent. The system is not selective, but gives the total concentration, reaching ppb sensitivity with high-quality data. In addition it includes temperature and humidity sensors, making the whole a useful instrument for environment control.  相似文献   

5.
Conditions of relative humidity (RH) and temperature within museums and buildings holding collections of cultural heritage objects are often maintained around a strictly controlled set point of about 50 ± 5% RH and 20 or 21 ± 2°C to provide safe, stable conditions for hygroscopic artifacts. It has recently been proposed that these ranges should be relaxed to values that are less energy-intensive to maintain while still being safe for the objects in the collection, with the aim of reducing both carbon footprint and energy use. It is also suggested that conditions should be determined by the needs of individual objects and by the local climate of the region, rather than applying overall values across the museum as a whole. This proposal has led to much discussion within the conservation community. The suggested values, a stable humidity within the range 40–60% RH and a stable temperature within the range 16–25°C for most objects, apart from the most vulnerable, are derived from the results of experimental research on the responses of individual materials to particular conditions of RH and temperature, as well as observations of the behaviour of cultural heritage objects in their own environments and on loan. This paper describes briefly the historical and scientific background to the present discussion.  相似文献   

6.
ABSTRACT

Conservation of wooden objects exposed outdoors is extremely difficult and complex due to their constant exposure to fluctuating weather conditions and biological degradation. Filling the gaps in such objects requires the use of specific materials that in particular can adapt to changes in wood dimensions in response to humidity variations. Various materials have been used so far for filling voids in wooden artefacts but none of them was entirely suitable. Therefore, the authors have attempted to provide the basic characteristics of the selected commonly used filling materials based on pine wood powder or glass microballoons as fillers and Paraloid® B-72, Klucel® G, or glutin glue as binders, as the first step in research aiming at developing new and more appropriate gap-fillers. Special attention was paid to the dimensional stability of filling materials upon drying and exposure to water vapour and liquid water. The overall results indicate that among the examined fills those consisting of Paraloid® B-72 and glass microballoons revealed best properties as they were relatively dimensionally stable upon drying and exposure to moisture – despite high absorption of water – and were quite easy to finish. Generally, better properties were observed for filling materials containing higher concentrations of adhesives and these materials will be modified in the next step of the research. Since the main drawbacks of the examined gap-fillers were low water resistance, poor dimensional stability upon drying or exposure to water vapour or liquid water, and fragility or friability, future research into their modification will head towards improvement of the above-mentioned properties.  相似文献   

7.
none 《文物保护研究》2013,58(1):77-86
Abstract

Parchment is produced by processing the dermal layer of animal hide through limited mechanical and chemical treatment and then drying it under tension. The weak condition of many historical objects made of this material is caused by chemical, biological and mechanical degradation. Repairing these objects by filling gaps with parchment or paper patches may be inadvisable, due to important differences in intrinsic strength, which can create tensions between old and new materials. Alternative filling methods may be used, consisting of the application of solid materials in the form of a powder or a suspension, used to create a solid sheet of reconstituted parchment. The solids may consist of any kind of collagenous material (powdered parchment or hide, gelatin), paper or a combination of the two. Published methods describe preliminary treatments (e.g.relaxation), application media (water, solvents, additives), use of additional consolidating membranes (Japanese paper, goldbeater's skin), use of adhesives for pasting and surface consolidation purposes, preparation of mechanically isotropic templates for infills and tinting with synthetic dyes. A comparative investigation of methods confirms that the mechanical properties achieved in these infills, such as tensile strength and elasticity, as well as their reproducibility, are acceptable for application in conservation practice.  相似文献   

8.
《文物保护研究》2013,58(4):307-315
Abstract

The application of triangulation laser displacement sensors to the continuous in-situ monitoring of the response of wooden cultural objects to variations in temperature and relative humidity in their environment is reported. The sensors are robust, fast and precise, provide non-contact measurements, and are capable of operating in the field. They have been applied to monitor the response of the altarpiece in the church of Santa Maria Maddalena in Rocca Pietore, Italy, to fluctuations in temperature and relative humidity caused by the use of the heating system. Complex short-, medium- and long-term responses of a variety of carved wooden elements have been recorded.  相似文献   

9.
ABSTRACT

Many museums are housed in historic buildings, sometimes the building itself is part of the museum collection. Creating a stable environment by providing a nearly constant temperature and relative humidity at correct levels decreases the risk of object degradation. Maintaining this steady indoor environment, however, increases energy consumption and risks to the historic building. Museum display cases offer a solution to the mitigation of risks to which valuable objects may be subjected by providing an extra layer of protection to indoor climate fluctuations. The Anne Frank House is a historic house museum located in Amsterdam. The museum has undergone several renovations in the last years to deal with an increase in the number of visitors to over 1.2 million a year. The original diaries and other documents of Anne Frank are permanently on display in the Anne Frank House. With the recent refurbishment the possibility arose to design a new state-of-the-art display case. This study presents the results of the experimental research related to the design, performed in-situ. The temperature and relative humidity in the new exhibition space and inside the new display cases were monitored to gain insight into the hygrothermal behavior of these controlled environments. A complementary numerical study was performed to investigate effects of dynamic climate control of the exhibition gallery and climate conditions in the display case under various circumstances. Four main conclusions are presented in this paper. The investigated display case design is able to provide a stable relative humidity environment by means of silica gel, while using an active box-in-box climate control system to create stable temperature conditions. The inner case temperature depends on the temperature supplied by the display case air handling unit. Protocols must be in place in case of malfunction or failure of the climate control system of the display case. The air handling unit of the case needs to be shut off to create a passive environment for the objects on display until necessary actions are taken. Exhibition gallery set points can be less stringent when susceptible museum objects are on display in the display case. The environments are separated and provide an opportunity for energy saving set point strategies. The last conclusion drawn is that the numerical study provides valuable insight into imposing dynamic control of set points for temperature and relative humidity in the exhibition gallery and the effect on the display case environment.  相似文献   

10.
《文物保护研究》2013,58(4):301-304
Abstract

The Ördekli Bath is an important fourteenth-century monument in Bursa, Turkey. The bath partially collapsed during the 1855 earthquakes. The plan, construction techniques and material properties of the bath have been investigated to determine whether they could have been partly responsible for the collapse of the men's frigidarium. In this study, the physical, mechanical and chemical properties of the original materials, sampled from both the stable and unstable parts of the bath, were examined and compared with each other. The test results showed that the building materials used for the bath are incredibly durable. It is therefore proposed that the collapse of the men's frigidarium was not caused by the intrinsic properties of the materials from which the bath was constructed. The collapse is thought to result from flaws in the original design and construction techniques used for the men's frigidarium.  相似文献   

11.
From rainy season to summer in Japan, the climate is humid. Especially in these seasons, it is difficult to maintain suitable conditions of temperature and relative humidity in exhibition and storage rooms in museums. Such climate conditions and problems are common to many countries in East Asia. Analysis using computer simulation can be a powerful tool because it is cheap and allows the simulation of a range of conditions without having to make changes to buildings and environments surrounding cultural objects. In this study, a storage building in which there is no air-conditioning unit was chosen as a target. The modelling of temperature and relative humidity in storage spaces was conducted using the Thermal and Airflow Network Model Simulation Program for buildings (NETS). The effect of seismic retro-fitting on the variation of temperature was predicted using NETS and the results were evaluated by comparing with the measured values. As a result, the heat transfer was successfully calculated and the modelled temperature represents the measured values reasonably well. Computing relative humidity by taking into account the effect of porous hygroscopic materials is challenging. In order to overcome this problem, the κ-ν model was adopted. We have some improvements but the study is still ongoing.  相似文献   

12.
ABSTRACT

Panel paintings are essentially wooden boards painted on one side. Due to the vapor resistance of the paint layer, changing ambient conditions lead to exchange of moisture on only one surface. Subsequently, a non-uniform moisture content profile is formed across the thickness of the board. As a result, differential expansion causes the board to bend in case of no mechanical restriction, or it leads to a build-up of stresses inside the material if restrained. Experiments with oak boards sealed on one side and exposed to a change in the ambient relative humidity (RH) were performed. By scaling, the response of any board with different thickness can be predicted. Since the bending of the board can be described as a linear system behavior, the frequency response can be predicted based on the step response. In combination with critical strains for wood and gesso from the literature, this gives insight into allowable RH fluctuations in terms of frequency and amplitude for different board thicknesses.  相似文献   

13.
《文物保护研究》2013,58(2):65-79
Abstract

Environmental standards for cultural heritage collections have been much debated in recent years. The interest in the issue has been driven by the growing movement towards green museums, that is, managing indoor museum environments in a responsible and efficient manner, especially in terms of reducing energy consumption and carbon emissions but at the same time maintaining high standards of collection care. Painted wood is among the category of heritage objects most vulnerable to relative humidity and temperature fluctuations. Therefore, scientific understanding of how changes in environmental conditions ultimately affect painted wood is crucial to the development of rational guidelines for the control of climate in museums and historic buildings. This review provides a systematic progression through two fundamental approaches to establish the allowable ranges of climatic variations – an analysis of the mechanical response of painted wood as a complex, multilayer system to climate variations, and an analysis of the historic climate to which the objects have acclimatized. The climate specifications and standards based on both these approaches are reviewed.  相似文献   

14.
ABSTRACT

Preventive conservation, with its origins grounded in the material fabric of cultural material, is in a period of transformation, with numerous practitioners, in and outside of the field of conservation, considering its broader and holistic objectives. The conventional tools for the assertion of preventive conservation principles, namely the assessment and management of risks to cultural material from the ‘ten agents of deterioration’, have a central focus on the primacy of physical materials and degradation, with less clear relationships with people, place, and time in their modelling. With a case study focus on collections in the Philippines, this paper argues for a practice of preventive conservation that incorporates a balanced assessment and broader thinking around the contexts of objects, people, place, and time. The case studies of ecclesiastical Church collections, and museum environments in the Philippines, demonstrate how the interdependency of objects, people, place and time forms a holistic and conceptual preventive conservation framework. Through a cyclic renegotiation of these four parameters, this paper speculates on the gaps and opportunities for an inclusive view of preventive conservation that is current and more sustainable.  相似文献   

15.
The conservation of wooden objects is complicated by their response to changes in their environment. In particular, filling voids in wooden objects can be difficult when their dimensions might be expected to alter over time. A short survey of conservators showed that a wide variety of materials have been, and are being used for this purpose. Following conservation work undertaken on a wooden coffin, the author wished to investigate the properties of cellulosic materials and their suitability in the conservation of wooden objects. This paper shares the results of experiments that were conducted to determine the way in which hydroxypropyl cellulose (HPC) and paper pulp fills respond in various conditions, as compared to other fill materials used by conservators. The compatibility of the HPC and paper pulp fills with wood is satisfactory enough to be able to recommend their use in the conservation of wooden artefacts, but ideally further experiments would be carried out, and on a wider variety of fill materials.  相似文献   

16.
Abstract

This paper describes the digital resources construction in China, such as e-books and e-journals, and the importance of e-learning for Chinese education. Knowledge objects are regarded as base elements in the microstructure of digital resources. The knowledge deconstruction and reconstruction process is proposed for creation and reorganization of knowledge objects that serve as the knowledge elements in teaching reference materials. Based on knowledge objects and the knowledge deconstruction and reconstruction process, the Digital Teaching Reference Book System (DTRBS) of Tsinghua University is designed and developed to provide the teaching reference book services in the platform of Web services.  相似文献   

17.
ABSTRACT

Glass is often seen as a relatively stable material, unaffected by changes in environmental conditions, but recent studies indicate otherwise. Research on the atmospheric deterioration of glass has consistently shown a strong correlation between climate, especially relative humidity (RH), and the rate of deterioration. New studies by the authors have shown that even stable compositions are at risk, when the glasses are exposed to continuous broad fluctuations in RH and temperature. Letting standards slip for the long-term storage of glass can be devastating, eventually leading to irreversible damage that in the final stages can result in the complete destruction of an object. Current research and monitoring of collections at the Corning Museum of Glass indicates that the RH should be within the range of 40–50%. For already crizzled glasses, a tighter control to 40–42% is recommended. Analysis of compositions of already crizzled glasses is ongoing, and hopefully will lead to the identification of at least some groups of glasses that are more at risk. This will help in providing future environmental recommendations for identifiable compositions, selected glass types, or known manufacturers.  相似文献   

18.
《文物保护研究》2013,58(4):251-268
Abstract

Extensive investigations of the deterioration of the romanesque painted wooden ceiling in the church of Saint Martin in Zillis (Switzerland) have revealed three major active deterioration phenomena: (1) tented flaking of paint layers; (2) flaking of the wheat starch fixative together with parts of the paint layer; and (3) fungal growth. These deterioration processes correlate with the dynamics of the prevailing room climate. Both forms of flaking are mainly driven by fluctuations of the relative humidity (RH), whereas the fungal attack can be related to high average RH and stagnant air. Frequent daily fluctuations in RH of up to 20% in summer are due to visitors leaving the doors open, while fluctuations of up to 25% are related to heating in winter. Given the risks of new consolidation treatments, the aim is to slow the decay processes by influencing the climate in the room. Installation of automatic door-closers reduced fluctuations but led to a rise in RH and a reduction of air movement, causing greater fungal growth. Subsequently, an automatic air-exchange system triggered by absolute humidity values was installed to reduce excess humidity and to exchange stale air without producing major fluctuations in the relative humidity. This kind of 'climatisation' has the advantage of being highly flexible, allowing variation of the rate and scale of exchange; it is, moreover, truly reversible.  相似文献   

19.
《文物保护研究》2013,58(2):79-87
Abstract

In the majority of cases, the red color of cinnabar on objects of cultural heritage is well preserved, though turning black is often claimed and has been the subject of investigations. To evaluate conditions for the stability of the pigment and understand the reactions, in this paper the problem is approached from various viewpoints. First of all the natural form cinnabarite is compared with the artificially prepared pigment vermilion. This establishes a differentiation of types in terms of quality, depending on structural impurities. With regard to the pigment's reactions influencing the discoloration, the most commonly mentioned environmental factors, such as radiation or halogens, are evaluated. In relation to various usages, the pigment's structural stability is then viewed in connection with adjacent pigments, glues, and the substrate, which may lead to a brown or black coloration or even the release of mercury, whereas the color is preserved in most cases when used on lime or in ink and lacquer. Due to the materials’ properties, attention is drawn to the fact that discoloration to a brownish-black is not necessarily a sign of damage and harmful reaction products, but may indicate good preservation of the painted material, provided that the mercury can be bound in the substrate.  相似文献   

20.
Air pollution is one of the environmental influences that degrade cultural heritage objects situated indoors. Other essential influences, such as temperature, relative humidity, and light are often well monitored. The presence of air pollutants is less often measured or included in risk assessment. The MEMORI® technology presented in this paper was developed as a tool for easy measurement and assessment of the general risk of degradation of heritage objects situated indoors due to indoor exposure to air pollutants. MEMORI dosimetry was performed in locations belonging to English Heritage and Tate (both located in London) and the National Archives of Norway in Oslo, to assess air quality. The related damage risk for collection objects and the protection offered by display and storage designs was assessed. A high level of acidic effect was observed inside a number of showcases, and a high level of oxidizing effect was observed in some room locations. Relatively simple mitigation measures, such as constructing tightly sealed showcases using low emitting materials, installing active carbon absorbing media inside a ‘microclimate’ frame, and using cardboard storage boxes for paper, significantly improved air quality. Overall, implementation of such measures is likely to improve the preservation of objects and reduce conservation costs.  相似文献   

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