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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
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Gary Burnett Paul T. Jaeger Kim M. Thompson 《Library & information science research》2008,30(1):56-66
Information access is central to library and information science, yet explorations of its conceptual nature have been limited. Given the importance of information access to the discipline, there is a need for research to create a better understanding of the concept and its many roles in all activities and behaviors related to information. Drawing on the theoretical work of Elfreda Chatman, this article proposes that the study of information access can be facilitated through the recognition and examination of the physical, intellectual, and social aspects of information access. These types of access are examined through three case studies in terms of different information behaviors and contexts, with a particular focus on the importance of social access. The article also discusses the future roles that considerations of social access can play in research and theory. 相似文献
77.
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
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V. A. Frolova S. K. Khasenova T. Sh. Kubieva O. A. Rog 《Scientific and Technical Information Processing》2008,35(2):104-106
This paper discusses the evaluation of scientific activity with the help of some scientometric indices, in particular, a citation index. The information massif of the bibliographic database of citations to domestic publications of Kazakh authors is statistically described. 相似文献
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Antony T. Sullivan 《Minerva》1995,33(1):37-43
Conclusions Palestinian teachers at the pre-collegiate level who participate in the CEEPAT programme will, it is hoped, learn to place new emphasis on enhancement of their students' analytical skills and discourage an identification of knowledge with memorisation. For their part, Palestinian professors who have been trained to teach in the programme will presumably constitute a growing reservoir of talent which may be expected to raise the quality of Palestinian university education. Plans are now under way to give all Palestinians teaching under the auspices of CEEPAT an opportunity to attend an annual, three-week winter seminar in Gaza and/or a summer seminar in the United States, both of which will focus on issues of pedagogy and methodology. Such professors can be expected to pass on their new understanding of teaching via discussion to their colleagues and to their university students, thereby spreading an important pedagogical method to other segments of the Palestinian... community. 7 CEEPAT clearly has the potential to make a significant contribution to the elevation of educational standards in Palestine at a time of major historical change.In Palestine, higher education of quality is obviously a very serious business. It is understood that it underlies any possibility of individual betterment, economic development, or the evolution of an independent Palestinian state. If ever the Israeli occupation is completely terminated and the present financial crisis of the universities is solved, Palestinian university and post-baccalaureate training may reasonably be expected to become fully competitive on an international scale. 相似文献