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1.
This paper reports the first systematic study of the dimensions of morphological changed microscopic collagen fibres in historical and new reference parchments with the aim to improve the knowledge on deterioration and the diagnosis of their damage in connection with conservation activities. The dimensions of fibres from the parchments were measured before and during shrinkage, with special emphasis on fibres with degradation characteristics designated as “pearls on a string” and “butterflies”. In addition, measurements of the total shrinkage of the length of fibres and pieces of parchment were also carried out. The observations support the assumption that in vivo transformation of the fibre structure by natural ageing is similar to that taking place when heating parchment and fibres in water. Based on statistical cluster analysis, four subpopulations of pearls representing different stages of deterioration are found. Moreover, the dimensional changes in the specific structures observed at room temperature can be related to specific temperatures in the interval of shrinkage suggesting that the hydrothermal stability of the fibres may be predicted on the basis of the ratio between length and width of the so-called pearls (Pl/Pw). The total shrinkage measured is drastic, in average around 56% for fibres and 43 to 48% for pieces of parchment depending on the direction of the skin. The total shrinkage of fibres corresponds to a mean change in the ratio Pl/Pw from around 10 to around 2.3. Finally, relations between the measured dimensions at the microscopic level with those of collagen at nanoscopic and molecular levels including known and potential chemical splitting points strongly indicate that the formation of the butterfly-like fragments formed by cleavage of two adjacent pearls in the fibre can be ascribed to chemical modification of specific tripeptides in the collagen molecule.  相似文献   

2.
Solid-phase microextraction (SPME)–gas chromatography (GC)–mass spectrometry (MS) has been applied to the analysis of acetic acid and furfural that are emitted from the fibres of Phormium tenax (Xanthorrhoeaceae) [New Zealand flax] during degradation. Accelerated hydrothermal ageing of fibres of the Ruawai cultivar of P. tenax for 55 days at 70 °C resulted in the production of acetic acid at a level greater or equal to 1.65 mg g–1 fibre. This corresponds to only 8.5% of the acetyl groups present in the fibres. These groups are an important source of acetic acid, which is capable of damaging the fibres. The rate of production of acetic acid suggests that a heritage object made from the fibres of P. tenax, that was stored in damp ambient conditions, would undergo significant deterioration after a relatively short period. Other volatile products released during ageing included furfural, a series of short to medium chain aliphatic aldehydes that were derived from the oxidation of long chain unsaturated fatty acids on the fibres and a small group of products that were derived from carotenoids. The levels of furfural were determined to be approximately 0.75% of the potential production but at these levels, furfural could contribute to unpleasant odours from unventilated items. Fibres from six cultivars of P. tenax were found to release acetic acid and furfural all at the same rate. The levels of acetic acid that can be generated from these fibres are sufficiently high that low moisture levels and continuous change of air is required to minimize degradation of cultural objects that are made from these fibres and displayed in museum halls.  相似文献   

3.
Dust accumulation is an important management and conservation problem in historic houses. Laboratory and field observations show that high relative humidity enhances the cementation of particles to underlying surfaces. The hygroscopic nature of particles or the fibres to which they adhere influences this cementation process. The cements, which can form in a matter of hours at high humidity, appear to be microcrystalline calcites. Reducing the impact of this process on heritage objects requires preventing dust deposits, especially in periods of high humidity.  相似文献   

4.
This paper provides an economic analysis of the survey responses of visitors who were asked to make a value for money (VFM) assessment of a museum visit. The paper first interprets the notion of VFM from an economic perspective, and distinguishes between evaluations made before and after a visit. It then analyses the survey responses of visitors to a major museum in the North of England, using appropriate statistical techniques to identify the economic determinants of VFM rankings by visitors. The final section discusses the implications of the methodology and results for museum management, and for the design of museum visitor surveys.The authors are grateful to the Joseph Rowntree Foundation which financed the visitor survey on which this study is based, to staff at Beamish Museum who made the survey possible, and to their colleague, Dr Barry Thomas, who was co-director on the original project. Valuable comments have been received from colleagues at Durham and from two anonymous referees. The authors however alone responsible for any errors and omissions.  相似文献   

5.
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   

6.
I investigate the intraday effects of rain on the demand for indoor leisure. To do so, I use sub-daily museum attendance and weather data to reveal a dynamic response to precipitation that would be obscured using day-level data. I find that the magnitudes and signs of the effects of rainfall vary significantly throughout the day. In some hours, the predicted increase in visitors is nearly three times larger than would be expected from estimates using daily measures. Many individuals appear to actively adjust their plans throughout the day in response to rain, while others’ attendance depends upon prior weather forecasts of rain. Further analysis reveals that visit duration also increases during rainy periods, and visitors are more likely to attend pay-to-enter special exhibits. International visitors make up a greater share of total visitors during periods of observed precipitation. More broadly, this paper establishes the viability and value of working with widely available sub-daily rainfall data to uncover these dynamics.  相似文献   

7.
The painting Il ritratto della figliastra (Portrait of the Stepdaughter) by Giovanni Fattori (1889, Gallery of Modern Art, Pitti Palace, Florence) was investigated using non-invasive fibre optics reflectance spectroscopy (FORS). The use of compact and transportable instrumentation made it possible to easily record spectra of the polychrome surface at the restorer’s atelier during the restoration work. The results of colour analysis before and after the cleaning procedure of the painting are reported and discussed, together with an attempt at pigment identification.  相似文献   

8.
We report the first results of a research study aimed at developing a new strategy for the conservation of wooden structural elements present in historical buildings, based on moisture regulating systems. As has been happening for artefact preservation in museums, the idea is to develop systems based on the ability of some highly hygroscopic materials to moderate variations in relative humidity. These materials could adsorb and release moisture to reduce the extreme values of humidity in the micro-climate, for example between wooden beams and masonry. In order to experimentally verify this possibility using current, low cost and easy handling building materials, 5 bentonite samples were laboratory processed to improve their adsorbing properties by means of treatment with sodium carbonate at 3 concentrations: 2, 3 and 4% by weight. The effectiveness of ion exchange between sodium carbonate and bentonite was controlled by measuring the swelling volume of the bentonites. All the samples (n = 15) were tested for their hygroscopic properties. Adsorption isotherms were measured at 25 °C, using desiccators with silica gel, saturated salt solutions and bi-distilled water. A comparison between isotherms of one of the lower hygroscopic treated sample of bentonite and of a sample of wood and of a sample of brick and some numerical analyses with the Delphin code were made in order to evaluate the potential use of this bentonite as a moisture regulating system for the preservation of historical wooden elements. Results show that it seems to be possible to use bentonites as a moisture buffering material in order to reduce moisture content in wooden beams at least during their adsorption phase. It remains to investigate their desorption phase and their behaviour if they be in a saturation condition. Further studies are currently under way.  相似文献   

9.
The renaissance frescoes of the metropolitan cathedral of Valencia, located at the vault of the apse, were restored in 2006. We describe a microclimate monitoring system that was implemented for the preventive conservation of the paintings. It is comprised by a set of temperature and relative humidity sensors positioned at different points of the vault. This system is rather unique because some of these sensors were inserted inside the paintings during the restoration process. A principal components analysis was applied to the data of relative humidity recorded in February 2007. The analysis was repeated in three additional months of 2007. The resulting loading plots highlight the most relevant similarities and dissimilarities among sensors. These plots can be considered as some sort of control maps that could be used to detect abnormal conditions in the future. Actually, moisture problems at certain zones of the frescoes are causing the formation of efflorescence, and the sensors located close to these zones are the ones recording the highest values of relative humidity.  相似文献   

10.
Superstar museums are characterized by (1) great prominence among tourists and world fame among the general population; (2) a large number of visitors; (3) a collection of generally known painters and individual paintings; (4) an exceptional architecture; and (5) a large role of commercialization, including a substantial impact on the local economy. The superstar phenomenon is caused by factors both on the demand and the supply side of the market. Superstar museums are forced to offer total experience to the visitors; they have to relate to events in history, technology, politics, films and TV, and they have to provide for everything from education, food, gifts, shopping to entertainment. The development of superstar status strongly affects museum policy. The strategic orientation emphasizes visitors' demands; the organization has to be decentralized into processes each devoted to particular segments of visitors, to special exhibitions or support activities. There are also major consequences for human resource management, in particular, relating to flexibility and staff composition of paid employees and volunteers.  相似文献   

11.
2014年元旦,书画家蔡云飞先生书画作品展暨《浙东唐诗之路》及《长征万里图》长卷首展在绍兴美术馆举行,给节日的文化名城增添了一抹亮丽的色彩。展会上,他的《浙东唐诗之路》受到行家和观众的啧啧称赞。  相似文献   

12.
GLobal Art MUseums as Economic Re-activators (GLAMUR) infrastructures are characterized by global media visibility and sheer presence in the communications environment; outstanding architecture by a superstar architect; big blockbuster exhibitions and a large number of visitors; being magnets for tourists; requiring large capital costs (initial construction costs plus ongoing investments) and large operating budgets; expensive advertising and commercialisation strategies; a huge operative risk; and a hope for substantial impact on the local economy. The economic value of cultural assets is defined as the extent to which they generate benefits for society. The aim of this article is to shed light on the valuation of GLAMUR infrastructures and why, and then to valuate the Guggenheim Museum Bilbao (GMB). In fact, the author of this paper argues that economic valuation through an estimate of the Willingness to Pay (WTP) (e.g. contingent valuation), is clearly an insufficient method for valuating a GLAMUR. One possible accurate method could be to calculate the Discounting of Cash-flows (DCF), followed by the discounting of the WTP estimates.  相似文献   

13.
Computer graphics, and in particular high-fidelity rendering, make it possible to recreate cultural heritage on a computer, including a precise lighting simulation. Achieving maximum accuracy is of the highest importance when investigating how a site might have appeared in the past. Failure to use such high fidelity means there is a very real danger of misrepresenting the past. Although we can accurately simulate the propagation of light in the environment, little work has been undertaken into the effect that light scattering due to participating media (such as dust in the atmosphere) has on the perception of the site. In this paper we present the high-fidelity rendering pipeline including participating media. We also investigate how the appearance of an archaeological reconstruction is affected when dust is included in the simulation. The chosen site for our study is the ancient Egyptian temple of Kalabsha.  相似文献   

14.
Conclusions This paper has demonstrated that visitors to professional theatre companies located in towns and villages of southern Ontario contribute to the economic well-being of the local economy. Furthermore, it has been documented that while all communities receive some monetary benefits, spatial variations are found to exist. These discrepancies are a function of differences in the average expenditures of non-local residents and the total number of visitors attending the theatre event. As expected, average expenditures appear to be highest in communities supporting a large commercial sector which are capable of sustaining a touris market. Moreover, the number of visitors attending a theatre event appears to be greatest in small communities supporting an established theratre company.  相似文献   

15.
SMART CLEAN is an innovative Nd:YAG laser system that has been designed to optimize laser cleaning procedures, especially for the treatment of altered stone surfaces. The project, originated by the co-operation of researchers and enterprises involved in optoelectronics system development, was aimed at improving the intrinsic features of the laser source, as well as some practical aspects, in order to facilitate laser application in the restoration yard. Emission characteristics were suitably tailored to obtain effective removal of alteration layers, and to minimize possible side effects. In particular, the pulse duration of the SMART CLEAN laser was set at 20 μs, by means of a proprietary design of the power supply. This was in order to reduce the risk of both mechanical and thermal damage to the artwork substrate, which is more likely to occur with short and long laser pulses, respectively. Moreover, this pulse duration permitted a reliable transmission of high laser energy through long optical fibres (50 m), which allowed easy cleaning operations on façades. The laser system was tested on a large variety of lithotypes and in operative cleaning interventions on Italian monuments.  相似文献   

16.
The artist Jordi Teixidor is one of the leading exponents of twentieth century Spanish abstract art. In recent years, he has used a synthetic polymer as a support for his art work, namely polypropylene. The behaviour of this material in combination with layers of oil paint has not been studied until now. One of the objectives of this study was to chemically characterise the material present in Jordi Teixidor's work, using FT-IR spectroscopy, in order to be able to examine the behaviour of this set of materials after undergoing cycles of accelerated aging. After subjecting the samples to temperature and relative humidity cycles and ultraviolet radiation, their physico-mechanical behaviour was determined via tensile and bend tests, with the results being processed further by means of spectroscopic techniques and colour measurements. It was found that the possible migration of the additives present in the PP support and the gradual degradation of the materials could affect the adherence between the paint layers in the future.  相似文献   

17.
Using over 100 years of biocides for preservation of collections of natural history museums has led to significant pollution of specimens and the environment of museums. Staff may be exposed to these substances as well by skin contact or by breathing dust and volatiles compounds. In this work, we present the results of a screening of volatile and semi-volatile organic compounds in the air and dust from the Natural History Museum of Rouen (Normandy, France). It is shown that the concentration in the air of the different substances is acceptable and below regulatory limits. Nevertheless, concentrations in dust especially for DDT and DDD are high and require special precautions and a regular dusting.  相似文献   

18.
Wool samples collected from thirteen Arraiolos carpets from the 17th–19th century belonging to the National Museum of Ancient Art (NMAA, Lisboa, Portugal) collection were analysed to identify the natural dyes and mordants employed in the traditional dyeing process, in a way to complement and improve actual knowledge on this rugs. Natural dyes were extracted from Arraiolos historical wool fibres using a mild extraction method, followed by high-performance liquid chromatography with diode array and mass spectrometry detection (HPLC-DAD-MS) for compound identification. Colourimetry was used to measure colour parameters in all historical samples. Quantification of mordants in the historical fibres was carried out by inductively coupled plasma-mass spectrometry (ICP-MS). Weld, indigo, spurge flax, brazilwood, madder and cochineal were identified as dye sources in the fibres. Alum was the most commonly used mordant, but the presence of iron and zinc was also detected in some darker samples. The use of madder and cochineal is not referred in the available historical dyeing recipes. This study also proved that the actual visual perception of these carpets is strongly affected by the natural dyes photodegradation, which was mostly unaccounted for before.  相似文献   

19.
Short crystallisation and deliquescence cycles of mirabilite, epsomite and gypsum are identified by using an automated monitoring system on-site. It consists of digital cameras and RH/T sensors which are computer-controlled and connected to the Internet. Digital images are processed to form a time-lapse movie, so that surface alterations are easily recognised. High resolution imaging (6 mega pixels) in combination with various lenses (12–24 mm zoom, 28–105 mm zoom, 20 mm inversed) results in a wide range of precise observation from 7 to 500 mm width of image. That is essential for discriminating phase transitions of single crystals at the same time as monitoring the evolution of the efflorescence as a whole. Crystallisation-deliquescence cycles are induced by small temperature and humidity variations. Mirabilite and epsomite undergo phase changes from crystallisation to deliquescence and vice versa at about 83% RH (15–20 °C). These equilibrium relative humidities are considerably reduced compared to the pure salt systems as a consequence of mixed salt solutions. Observations confirm predictions by ECOS simulation based on chemical analyses of water extracts from the site. Dehydration of mirabilite is observed when the relative humidity drops below 65% RH. Mirabilite exhibits the most pronounced and rapid phase changes in response to indoor climate variations. As an example, whisker crystals of 1–3 mm length grow within one up to some days. Epsomite responds fainter and slower. Crystallisation of gypsum is distinguished by the growth of new crystals on the stone surface. They have a size of about 10 μ – which is close to the image resolution – when they appear on the image. Crystallisation is associated with an increased granular disaggregation of the stone surface. Rhythmical crystallisation of gypsum appears to correlate with small relative humidity variations of ±2–5% within a band from 65 to 75% RH in the room. However, this needs to be clarified in detail.  相似文献   

20.
在王尔德的小说《道连.格雷的画像》中,一个情节让人难忘——艺术家霍华德对他倾注了感情的漫画对象道连.格雷说：＂你已经成了我看不见的理想的可见的化身。＂在很多人眼里,漫画等于幽默、调侃、生活调剂品,而非正统意义上的艺术形态。  相似文献   

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