NSF/CONACyT: Protection of Mayan Archeological Sites in Southern Mexico from Biodeterioration

9906337米切尔高湿度和高温的结合，加上旅游活动的增加，正在导致墨西哥南部玛雅考古遗址的迅速恶化。 建造这些建筑物所用的大部分材料是软石灰石，这种材料机械强度低，容易发生生物退化。 本研究的目的是测试保护建筑材料免受进一步恶化的方法。 该研究将与Escuela de Ingenieria，Universidad del Mayab密切合作进行。 该项目由国际方案司和国家科学基金会/国家科学技术委员会方案共同支助，在以前支助的工作中已经确定了奇琴伊察和乌克斯马尔地点的微生物群落在石头降解中的重要性。 在石头上发现了大量多样的微生物种群，它们深深地渗透到石灰岩中。 当地的微生物群落具有降解许多聚合物固化剂的能力。 这项持续研究的目的是在实地条件下测试一些与杀生物剂结合的聚合物固化剂，并开发一种适当的控制混合物，在当地条件下抵抗生物退化。 该项目的最终目标是测试保护这些考古遗址免受破坏的方法。研究分为三个阶段。 第一阶段将包括实验室测试各种固结剂与商业上可获得的环境可接受的杀菌剂的组合，以找到适当的组合，以提供最大限度的保护，防止当地的石头微生物。 在研究的第二阶段，处理过的石头将被放置在墨西哥南部的两个地点。 将使用电子显微镜和电化学阻抗谱测试聚合物材料的微生物污染、渗透和降解程度。 在第三阶段，将在奇琴伊察和乌克斯马尔的广泛地点，在各种环境条件下，包括阳光、阴影、外部石材表面和建筑物的内部房间，放置经过最具抵抗力的固化剂和杀菌剂组合处理的当地石材。 材料将定期返回哈佛，以详细分析微生物菌群和生物降解的侵袭。***

9906337 Mitchell The combination of high humidity and temperature, together with increased tourist activity, is causing rapid deterioration of Mayan archeological sites in southern Mexico. Much of the material used in the construction of these buildings was soft limestone, which is mechanically weak and susceptible to biodeterioration. The objective of this research is to test methods for protection of the building materials against further deterioration. The research will be carried out in close cooperation with the Escuela de Ingenieria, Universidad del Mayab. This project is jointly supported with the Division of International Programs and with the NSF/CONACyT Program.The importance of the microflora in the degradation of stone at sites at Chichen Itza and Uxmal has been determined in previously supported work. A large and diverse microbial population has been found growing on the stone, with deep penetration into the limestone. The local microflora has the capacity to degrade a number of polymeric consolidants. The objective of this continuing research is to test a number of polymeric consolidants combined with biocides under field conditions and to develop an appropriate control mixture that would resist biodeterioration under local conditions. The ultimate goal of this project is to test methods to protect these archeological sites from deterioration.The research is divided into three phases. The first phase will consist of laboratory tests of a wide range of consolidants combined with commercially-available environmentally-acceptable biocides to find an appropriate combination to provide maximum protection against the local stone microorganisms. In the second phase of the research, treated stone will be place in the field at two sites in southern Mexico. The degree of microbial contamination, penetration and degradation of the polymeric materials will be tested using both electron microscopy and electrochemical impedence spectroscopy. In the third phase, local stone treated with the most resistant combination of consolidants and biocides will be placed at a wide range of sites, both in Chichen Itza and Uxmal, in a variety of environmental conditions, including sunlight, shade, on external stone surfaces and in inner rooms of the buildings. Materials will be returned to Harvard at frequent intervals for detailed analysis of attack both by the microflora and biodeterioration. ***