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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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Louisa Ha 《Learned Publishing》2003,16(3):193-199
This article re‐examines the economics of publishing scholarly journals and illustrates the dilemma of publisher identity and publication format with a case study of the Association for Education in Journalism and Mass Communication's Media Management and Economics division. The study investigates the perceived interest and demand for a society‐published journal for the field of media management and economics and the preferred format for that journal – print or online. Results showed a divided opinion on the support of a society‐published journal and no consideration of the benefits or harms of journal publishing to the society. The print journal, though a desirable format for authors, is deemed uneconomical. The online journal is viewed as a feasible publication outlet, but its status as a prestigious journal is doubtful. Applications of scholarly journal publishing and economic models to the case are discussed. 相似文献
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How will the expansion of the concept of construct validity affect validation practice in employment testing? How does the need for consequential validity differ in educational and employment testing? How do the research bases differ for performance assessment in these settings? Are there parallel trends in policies for test use in education and industry? 相似文献
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