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1.
Poul Klenz Larsen 《文物保护研究》2018,63(5):164-169
ABSTRACTHistoric buildings in Denmark have a high relative humidity (RH) all year, so the interiors are exposed to biological degradation. The acceptable range for RH is 60–70%, which is higher than the usual recommendations for museums and galleries. There are two options for humidity control: conservation heating or mechanical dehumidification. Calculation of the energy performance of a generic building was used to determine which method is the most efficient. Studies of a cottage in Liselund Park, and of two medieval churches in Hellerup and Vemb have confirmed these predictions: dehumidification is less energy consuming than conservation heating in buildings with poor thermal insulation and a moderate air infiltration rate (AER?<?0.6?h?1). Dehumidification is suitable for historic buildings, where heating is not needed for human comfort. A condensing dehumidifier uses less than half the energy per kg water compared to an absorption dehumidifier. But it does not work at temperatures below 2°C. The combination of a condensing dehumidifier and a little heating to prevent frost is the most energy efficient solution for humidity control. These results are only valid in mild and humid climatic conditions similar to Denmark. 相似文献
2.
ABSTRACTThe 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
3.
ABSTRACTPanel 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
4.
ABSTRACTGlass 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
5.
ABSTRACT Adsorbent materials can be used for the removal of organic acids from air in storage rooms with heritage collections. The organic acid removal efficiency of two commercially available activated carbon air-filters were tested in situ in two unoccupied stores with densely packed collections. One filter was designed for outdoor type pollutants (Filter A), while the other was designed for organic acids in indoor air (Filter B). Furthermore, the acetic acid removal efficiency of a desiccant silica gel rotor used for dehumidification was measured in a laboratory at different relative humidity levels. Finally, passive removal of acetic acid by silica gel and unfired clay brick were tested in a chamber, and for clay brick at room level as well. Filter B had the highest removal efficiency. The removal efficiency of both filter types depended on the airflow and the filter performance varied considerably in situ from the values reported from standard laboratory tests. Increasing the filter airflow reduced the removal efficiency from 77% and down to 7% for Filter A, and from 92% to 24% for Filter B. There was almost no effect of active air filtration on the concentration of organic acids when this was measured in the middle and in the corner of the storage rooms away from the ventilation inlets. The desiccant dehumidifier removed 98–100% of the acetic acid from the air, independently of the relative humidity. The desiccant rotor will, however, only be running when there is a need for dehumidification and as a result will only periodically remove pollutants. The high acid removal efficiency by dry silica gel was furthermore demonstrated in a chamber test. A clay brick wall in a test room established a concentration gradient across the room and reduced the concentration of organic acids by 56% compared to close to the emission source. 相似文献
6.
ABSTRACTAmong more than 600 decorated tumuli in Japan, we focused on Hinooka tumulus in Fukuoka prefecture. In order to preserve the stone chamber and paintings, a reinforced concrete shelter was built in 1964 on the stone chamber. From the preservation point of view, one of the main problems in the shelter is condensation on the ceiling especially in winter. In order to understand the mechanism of the formation of condensation in the shelter for Hinooka tumulus and to consider countermeasures to prevent it, the thermal environment inside the shelter was investigated by in situ measurements and computer simulations. Since the relative humidity inside the shelter is almost 100% throughout the year, it turned out that dew condensation tends to occur especially in winter when the temperature on the surface of the ceiling becomes low. The results obtained by computer simulation suggests that the amounts of condensation on the surface of the ceiling can be reduced if the thermal insulation of the roof is increased by adding materials which do not attract pests. Synthetic heat insulation material is one of the candidate materials for reducing condensate on the ceiling of the shelter for the Hinooka tumulus. 相似文献
7.
ABSTRACTIn the Mogao Grottoes of Dunhuang, China, the ambient relative humidity (RH) fluctuation in the caves is the main cause for the deterioration that has been observed, especially the deterioration of the earthen plaster and wall paintings linked to the presence of NaCl and Na2SO4 salt contaminants. To help identify the mechanism responsible for this salt-related deterioration and provide a theoretical basis for the development of a preventive conservation regime, this study addressed the basic moisture adsorption mechanisms of earthen plaster with soluble salts by taking an experimental approach. It is shown that, as ambient RH increases, the moisture adsorption process of the plaster containing the soluble salts can be regarded to have three basic stages, as evidenced by the results of the moisture adsorption tests performed on earthen plaster samples with different NaCl or Na2SO4 contents at various humidity levels. The moisture adsorption mechanism and its determining factors at each stage are also analysed. In addition, it is suggested that the hygroscopicity of the plaster structure and the interaction between the different kinds of salts in the plaster, which makes the dissolution or hydration of the salt in the plaster pores much easier, should be considered more seriously regarding increases in the ambient RH in the caves. 相似文献
8.
《文物保护研究》2013,58(1):8-17
AbstractAbsorbent materials such as wood, paper and cotton stabilize the atmosphere of show-cases against the relative humidity changes caused by temperature variation and by exchange of air with the surroundings.There are several exchange processes between the air in the case and the outside air: diffusion through porous COllstruction materials, air flow caused by temperature and pressure changes and airflow by convection in a show-case whose relative humidity differsfrom that of its environment. The air changes about once a day in show-cases made by conventional joinery techniques. The rate of exchange can be reduced to less than five volumes a year by sealing a show-case so that only one small hole is left for pressure equalization. A dust and sulphur dioxide filter can then be fitted to maintain a pure atmosphere within.In heated rooms without air-conditioning the RH may fall dangerously low in winter. A static method of RH control for a show-case is described. This is a saturated solution of sodium bromide covered by a silicone rubber membrane. 相似文献
9.
《文物保护研究》2013,58(4):229-240
AbstractThis paper describes a novel technique to stabilize the relative humidity (RH) of the air inside museum showcases by using a synthetic hydrophobic membrane coupled with a hygroscopic solution in a membrane contactor. RH-monitoring data for two identical test cases, one of them controlled by a set-up with a plane-plate membrane contactor crossed by forced air and lithium chloride (LiCl) solution flows, show a significant stabilizing effect on RH fluctuations. A theoretical model permits forecasts in close agreement with the experimental RH data. Further calculations carried out over a one-year period show that notable damping of external RH variations can be obtained by using a low air circulation rate, small membrane surface area and low solution mass per unit case volume. A more general analytical solution in harmonic conditions is derived and discussed. 相似文献
10.
ABSTRACTThis study examined the impact of relative humidity (RH) on the corrosion rate of 129 archaeological iron nails from two sites. Oxygen consumption of individual nails in controlled RH was used as a corrosion rate proxy to deliver quantitative data on corrosion rate as a function of RH. This was negligible at 20% RH, slow up to 40% RH for both sites, and increased rapidly at 60% RH for Roman nails from Caerleon (Wales) and at 70% RH for medieval nails from Billingsgate (London). The nails were digested and their chloride content was determined and related to their oxygen consumption at specific RH values. While a generic pattern of corrosion as a function of chloride was identified, for any single concentration of chloride corrosion rate was not predictable. Desiccation is in common use to control post-excavation corrosion of archaeological iron; quantifying how differing levels of desiccation changed corrosion rate provided a scaled tool for identifying corrosion risk, estimating object longevity, and calculating cost benefit for storage options. 相似文献
11.
《Journal Of Access Services》2013,10(1):3-10
ABSTRACT The George A. Smathers Libraries of the University of Florida is currently undergoing a major renovation. Library West, the building that houses the humanities and social sciences collection, will be gutted and expanded. The collection will be moved to off-site storage and the staff will be relocated for a two-year period. The reality of these changes has created a feeling of anxiety and uncertainty, especially in the Access Services Department. FISH is a customer service tool that has been adopted by the UF Libraries because it ensures a positive attitude for staff in their daily work. A FISH committee is in place and many morale-boosting activities have been scheduled. The FISH committee will be challenged during the next two years to meet the morale needs of the staff. 相似文献
12.
《文物保护研究》2013,58(2):88-94
AbstractThis paper examines the impact of relative humidity on jades by enclosing the samples under constant relative humidity (RH) of 32, 49, 61.5, and 81.7% at the same temperature of 40 ± 0.1°C for 160 days. The simulated samples were pure and dense tremolite jade and serpentine jade, impure tremolite jade and serpentine jade containing some calcite, and serpentinized calcite, which are all common materials of ancient jade found in archaeological excavations. All samples were characterized through particle-induced X-ray emission and a glossmeter. The degree of deterioration proved to be greater in impure materials than in pure ones. The best RH to conserve various kinds of materials differs: for pure tremolite and serpentine, all of the RH levels are equal; for impure tremolite with some calcite, 61.5 and 81.7% were superior; for impure serpentine with some calcite, the highest RH (81.7%) was best; and as to the serpentinized calcite, there is no clear conclusion as yet and further research is needed. 相似文献
13.
ABSTRACTControl of relative humidity (RH) for collections care is challenging in U.K. historic houses because they are often highly ventilated with poor heat retention, a porous building fabric and naturally tend to high (60–80%) RH if unheated. The significance of the building means that large-scale modifications and installation of air handling systems may be unfeasible and undesirable for the conservation of the building. In the late 1980s the National Trust, for English, Wales and Northern Ireland, investigated conservation heating as an RH control method that works with the natural environment of historic buildings, mimicking historic heating and requiring only modification of existing heating services or a light touch installation of new heating systems. The National Trust adopted conservation heating as its preferred method for environmental control in historic buildings from the 1990s. This method was presented at the IIC 1994 Ottawa congress on preventive conservation. Conservation heating has since been adopted by many historic house management organisations, particularly across north-west Europe, where it is well suited to the climate. This paper reviews conservation heating developments implemented by the National Trust since 1994, in response to a changing external context, new knowledge and developments in operational practice. 相似文献
14.
ABSTRACTThe National Museum of Ethnology, Osaka, Japan, collects a vast amount of materials and information related to peoples’ life and culture, and makes them available to society through exhibitions and other activities. The number of collected items is increasing every year: 343581 objects have been collected from Japan and abroad as of March 2017. The continuous efforts have been necessary to improve storage conditions and to save space for both general and special storerooms. The former, which account for 90% of the storage capacity of the museum, are air-conditioned during working hours, with temperature and relative humidity (RH) settings varying with the seasons. The latter, which house objects for which strict conservation conditions are required, are air-conditioned for 24 hours with fixed settings of temperature/RH throughout the year determined by the nature of the materials from which the objects have been made or formed. Storage re-organization began with special storerooms, for which the number of objects and the storage area are far more limited in comparison with the general storerooms. The storage shelves for fur/skin/feather (almost 1000 objects) and for carpets (almost 550 objects) were all renewed in FY2007/2008. Then two large-scale innovation projects for general storerooms were conducted: construction of storage areas for ships equipped with a CO2-based and anoxic pest treatment facility (FY2015), and a complete refurbishing of the general storeroom for large objects (FY2016). Windows were set in the corner of this storeroom to provide visitors an opportunity to view and learn about the museum activities. In parallel to the above projects, daily storage improvement efforts have been undertaken. Storeroom No. 3, chosen as an example for general storerooms for small and medium-sized objects, was used to investigate the range of issues related to the shelving arrangement and storage conditions. Guidelines for storage re-organization were formulated according to the results of the investigation and according to the experiences gained through the renewal of special storerooms. Storage re-organization undertaken in storeroom No. 3 was conducted for 6 years at the rate of around 2000–4000 objects per year with a low budget and with reuse of existing shelves. In FY2016, all objects in storeroom No. 3 were properly redistributed. About 40% of the storage space was saved. Over these 10 years of storage re-organization, preventive measures have been taken for sustainable collection management. As early as FY1992, pest trap investigations have been carried out seasonally. Since FY2004, the results of investigations have been analyzed using a customized computer program. Subsequently, appropriate integrated pest management measures have been taken. In addition, since FY2014, energy-efficient air-condition control has been adopted for general storerooms. It consists of switching off air-conditioning in spring and autumn, and of starting it only when the temperature or RH values become too high in summer or too low in winter. Because the turning-off of air-conditioning causes comparable or even less climatic fluctuation, it was considered acceptable both economically and from a conservation perspective. It is estimated that turning the air-conditioning off during transitional seasons brings cost savings of about 3000000–4000000 JPY (about 26800–35700 USD as of 23 September 2017) per annum, which accounts for almost 30% of the electricity expenditures for all general storerooms. 相似文献
15.
《图书馆管理杂志》2012,52(3-4):321-331
ABSTRACT Special collections play an increasingly important role in university libraries. As library collections move to digital formats and collections are similar from one library to another, special collections are one of the ways in which libraries can build a distinct identity. Because of their unique nature, special collections must be permanently retained because of their artifact value and need specialized storage conditions with appropriate levels of security. Library administrators will increasingly face the need to provide expanded space for special collections as well as improving storage conditions to ensure that unique and valuable materials are preserved for research in the future. 相似文献
16.
《文物保护研究》2013,58(1):20-3
AbstractSevere corrosion was found covering the brass beads on several beaded belts. The corrosion was a mixture of copper soaps and zinc soaps, and was so thick in some places that it completely buried the brass beads. One of these belts was chosen as a test case for cleaning. The details of the cleaning are described, as are the effects of the corrosion process on the beads and surrounding organic materials. Two supporting studies are also reported: tests of the solubility of the corrosion in a variety of organic solvents, including mixtures of ethanol and petroleum-based solvents; and tests of leather dressings and other coatings on brass, copper, and zinc coupons in various relative humidities (RH), to determine what values of RH could be recommended for storage. 相似文献
17.
为了确保政府信息资源公共获取绩效评估的科学性和客观性,需要构建多元化的评估主体.构建多元化的评估主体,需要坚持和遵循三个基本原则,即立足现实、兼顾内外、科学配比.政府信息资源公共获取绩效评估主体既包括同体评估主体,又包括异体评估主体. 相似文献
18.
《Public Library Quarterly》2013,32(1-2):117-135
SUMMARY There is renewed interest in building and sustaining support for public libraries in this country. This paper looks at the concepts of marketing and advocacy as integral components for building this sustain-ability and uses two related initiatives in the State of Kentucky to illustrate, in practice, how these concepts differ and how they need to work together for long term success. In short, “selling” libraries in itself won't get the job done; nor will just building a public advocacy infrastructure. Taken together, however, both can advance the case for libraries and build the support needed for sustainability. 相似文献
19.
ABSTRACTHealth information skills in an electronic environment are essential to health science librarians, who serve as educators both within and outside of their health training institutions. This reflective study was conducted to examine the application of online health information skills obtained from the training provided for librarians who are working in health settings. Health sciences librarians, as future information skills educators, therefore need to possess their own health information skill sets. Capacity building is vital in order to promote the development of health information skills for health sciences librarians who can then teach and advocate the concept of health information skills on the Internet within and outside of their places of work. 相似文献
20.
《Public Library Quarterly》2013,32(3-4):113-125
SUMMARY When the symptoms of a possible sick building syndrome appeared in a library building more than twenty years ago, it was thought that the situation could be easily fixed. Instead, we are still managing a problem building although extensive work has been done and much progress has been made to moderate the physical reactions of staff and building users. Looking after the well being of our staff has been the primary motivation. 相似文献