ASSESS VIABILITY OF MICRO-CT FOR SOIL MICROSTRUCTURE STUDIES

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 砂的微观结构可以提供宏观尺度材料响应的重要见解。 以前有研究使用CT来量化砂的微观结构。 使用传统CT的土壤微观结构的研究遭受之间的权衡分辨率，穿透深度，和试样尺寸。为了避免这些问题，PI使用了破坏性的法医技术，包括树脂浸渍砂标本，然后切片和抛光试样，用于随后的图像捕获和分析。 该方法以极高的分辨率产生高质量的结果，但是劳动密集型、缓慢，并且仅提供关于土壤微观结构的统计信息（即，每个单独颗粒的位置和取向是未知的）。 能够测量组件中每个粒子的位置、形状和方向将允许校准和验证数值模型，并将提供一种快速模拟各种实验室测试的方法。PI希望在杜克体内显微镜中心对单个砂样进行成像，以评估微CT用于土壤微结构研究的可行性。 如果这被证明是一种可行的方法来量化沙子在微观尺度上，建议将提交给资助机构有兴趣资助微观研究的颗粒材料，如国家科学基金会和空军科学研究办公室。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The microstructure of sands can provide significant insight into macroscale material response. There have been previous studies that use CT to quantify the microstructure of sands. The study of soil microstructure using conventional CT suffers from tradeoffs between resolution, penetration depth, and specimen size. To circumvent these issues, the PI has used a destructive forensic technique that involves resin impregnation of sand specimens followed by sectioning and polishing of coupons for subsequent image capture and analysis. This method produces high quality results at extremely high resolutions, but is labor-intensive, slow, and provides only statistical information regarding soil microstructure (i.e., the location and orientation of each individual particle is not known). Being able to measure the location, shape, and orientation of every particle in an assembly would allow for calibration and verification of numerical models and would provide a means for rapid simulation of a wide array of laboratory tests. The PI would like to image a single sand specimen at the Duke Center for In Vivo Microscopy to assess the viability of micro-CT for soil microstructure studies. If this proves to be a viable method for quanifying sands on the microscale, proposals will be submitted to grant agencies interested in funding microscale research on granular materials, such as the National Science Foundation and the Air Force Office of Scientific Research.