Water In Frozen Media

技术摘要：研究了引起冻土冻胀的冰的预融和温度分子压力的基本依据。用偏光法和干涉显微镜研究了冰的单晶表面上这种效应的动力学，其中界面熔化导致一层薄薄的液体膜润湿界面。实验结果与理论结果进行了比较，探讨了取向依赖性和邻近效应。该计划的第二部分研究了单尺寸粉末中未冷冻液体的运输，作为多孔介质的简单例子。非技术摘要：该程序研究冻胀的基本机制。通常，在冻土中，当水分被吸引到较低的温度时，就会发生冻胀。这个项目通过测量对单晶冰的影响来研究基本的驱动压力和水分的流动。实验结果与基于一种新的、详细的冻胀理论的预测结果进行了比较。该计划还包括在多孔介质中霜胀的研究，使用专门制备的人工粉末。这些粉末比典型的土壤更均匀，因此可以与理论进行更详细的比较。＊＊＊

9400637 Dash Technical abstract: The research studies the fundamental basis of premelting of ice and thermomolecular pressure, which cause frost heave in frozen ground. The dynamics of the efect are studied, by polarimetry and interference microscopy, on single crystal facets of ice, where interfacial melting causes a thin liquid film wetting the interface. The results are compared with theory, to investigate the orientation dependence and the proximity effect. A second part of the program studies transport of unfrozen liquid in monosized powders, as simple examples of porous media. Non-technical abstract: This program studies fundamental mechanisms of frost heave. Typically, in frozen ground, frost heave occurs as moisture is drawn toward lower temperatures. This project investigates the basic driving pressure and the flow of moisture, by measurements of the effect on a single crystal of ice. The experimental results are compared with prediction based on a new, detailed theory of frost heave. The program also includes a study of frost heave in porous media, using specially prepared artificial powders. These powders are more uniform than typical soils, thereby permitting a more detailed comparison with the theory. ***