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

9906337米切尔高湿度和高温度，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。建造这些建筑时使用的大部分材料都是软石灰岩，这种石灰岩的机械性能很弱，很容易被生物降解。这项研究的目的是测试防止建筑材料进一步变质的方法。这项研究将与Escuela de Ingenieria(Mayab大学)密切合作进行。该项目是与国际方案司和NSF/CONACyT方案共同支持的。在以前得到支持的工作中，已经确定了微生物区系在奇琴伊萨和乌克斯马勒遗址石材退化中的重要性。在石灰石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。当地的微生物区系有能力降解许多聚合物固化剂。这项持续研究的目的是在现场条件下测试几种聚合物固化剂与杀菌剂的组合，并开发一种在当地条件下能够抵抗生物退化的适当控制混合物。这个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。第一阶段将包括对各种固结剂进行实验室测试，并结合商业上可获得的环境可接受的杀菌剂，以找到适当的组合，最大限度地保护当地的石材微生物。在研究的第二阶段，处理过的石头将被放置在墨西哥南部两个地点的田野中。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，将在奇琴伊扎和乌斯马勒的各种地点放置经过最耐受固化剂和杀生剂组合处理的当地石材，放置在各种环境条件下，包括阳光、树荫、石材外部表面和建筑内部房间。材料将被频繁地送回哈佛大学，以详细分析微生物群和生物退化造成的攻击。***

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. ***