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41.
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
42.
赛艇运动的项目特性及训练指导思想 总被引:13,自引:4,他引:9
通过对赛艇运动项目决定成绩的因素,如供能系统、专项素质、生理特性的分析,确定了赛艇运动的特性及规律,并据此特性科学地提出了该项目的训练指导思想. 相似文献
43.
Jajko P 《Medical reference services quarterly》1992,11(1):63-66
Successful hospital and corporate libraries offer customized resources and services to meet the needs of their dynamic organizations. Concepts such as customer-driven, service-oriented and value-added are central to these libraries. Serving decision makers and integrating the library into the decision-making process of the organization is critical. Future articles in this new column will further explore the underlying philosophies and the specialized resources and services that characterize these libraries. 相似文献
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Richwine PW 《Medical reference services quarterly》1991,10(4):29-37
EPIC is a service that provides keyword or subject access to the OCLC Online Union Catalog (OLUC). This capability increases the success rate for title location as well as the potential uses of the OLUC. The features of the EPIC system, application of these features to the OLUC, and specific uses in health sciences libraries are described in this article. 相似文献
48.
如何实现"简化IT"的战略,这是困扰很多企业,尤其是CIO的一个重要问题。本文以日本新生银行的例子来诠释如何彻底简化IT。中世纪哲人William of Ock- ham说过,理论应该尽可能的简单。同样的原则适用于企业IT系统:它们按照尽可能少的标准 相似文献
49.
O. P. Morozova 《Scientific and Technical Information Processing》2008,35(3):153-154
The web coverage of the research activities of the VINITI RAS is considered. The practicability of using various information retrieval systems for obtaining information relevant to the Institute’s functioning and results is analyzed. 相似文献
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