Environmentally-induced stone decay: the cumulative effects of crystallization–hydration cycles on a Lincolnshire oopelsparite limestone

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.     

赛艇运动的项目特性及训练指导思想

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.     

Educational and Employment Testing: Changing Concepts in Measurement and Policy

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?     

Education in Foreign Languages at Vilnius Technical University

The paper deals with studies of engineering programmes in foreign languages at Vilnius Technical University (VTU), Lithuania. In order to organize studies in foreign languages, an International Studies Centre was established in 1992. The following aims were pursued: integrating into the systems of university education of European countries and promoting international exchange of students and staff. BSc studies (architecture, civil engineering, mechanical engineering and electronic engineering programmes) are organized in English, French and German. Over 150 undergraduate students from Lithuania and foreign countries are studying at the centre. About 150 students are enrolled for the next academic year.     

皮划艇运动员膳食营养调查与评价

经连续五天称重法进行的膳食营养调查发现，我省皮划艇运动员（男性）以膳食中实际获得的营养素跟供给量标准比较，总热量与各营养素的摄入量除维生素Ａ不足（仅占标准的７８．１％）外，其余均超标；三大热能营养素的比例不尽合理（蛋白质２０６．９克，脂肪１７１．５克，碳水化物７０２克分别占总热量的１６％、２９．８％和５４．２％），脂肪量偏高，碳水化合物相对不足。建议在食谱中增加主食、减少脂肪，同时补充维生素Ａ，从而保证皮划艇运动员能得到合理的营养。