CDI-Type II: Collaborative Research: Computational Homology, Jamming, and Force Chains in Dense Granular Flows

摘要电极导线：0835742非电极导线：0835571、0835611、0835621 PI：C。O？Hern（Lead），R.贝林格湖Kondic，K. MischaikowCDI-II型：合作研究：密集颗粒流中的计算同调、堵塞和力链该项目将采用高度跨学科的方法，将新的几何技术、建模和实验相结合，以解决有关颗粒介质和其他堵塞材料（如玻璃、泡沫和胶体）的物理特性的基本、开放性问题。 堵塞材料的特点是它们像固体一样抵抗外力，但像液体一样无序。 此外，当施加外力时，许多堵塞的材料具有称为力链网络的异质的、分叉的结构。 虽然人们几十年前就知道力链的存在，但对它们在物理过程中的作用的定量理解已经被证明是难以捉摸的，部分原因是以前的研究无法为它们设计一个公正和普遍的定义。 力链的精确识别和表征以及堵塞材料对作用力的响应可能会在许多领域产生变革性影响。 例如，仅在美国，处理和加工颗粒材料的财务和能源成本（通常具有高效率）估计至少为一万亿美元。 此外，雪崩和地震是颗粒介质的不可预测行为对人类产生负面影响的例子。 在这项工作中，我们将采用新的数学技术，加上计算机模拟和实验，以获得定量的，预测性的描述堵塞的材料。该项目的外联工作强调向代表性不足群体的学生提供教育机会。 我们将组织教育和招聘之旅，以女性为主的文理学院在东北部和历史上黑人学校在北卡罗来纳州，如北卡罗来纳州中央大学，和其他在东南部。这些旅行将包括提供技术和流行的讲座，包括演示，以表明对堵塞材料的研究是有趣和重要的。 在与学生的非正式会议，我们将强调，在科学和技术的职业生涯是有益的，并开放给那些在代表性不足的群体。 为了进一步激发学生对这项研究的兴趣，我们将每年举行两次为期两天的实验室开放日，以便有前途的本科生可以接触到我们研究的实验和理论方面。 为了鼓励研究人员在堵塞材料领域的密切合作，我们将组织一年两次的跨学科研讨会。 首届研讨会，“计算同源工具应用于堵塞和流动的颗粒材料”定于2009年冬季。

AbstractLead: 0835742 Non-leads: 0835571, 0835611, 0835621PIs: C. O?Hern (Lead), R. Behringer, L. Kondic, K. MischaikowCDI-Type II: Collaborative Research: Computational Homology, Jamming, and Force Chains in Dense Granular FlowsThis project will employ a highly interdisciplinary approach that integrates new geometrical techniques, modeling, and experiments to address fundamental, open questions concerning the physical properties of granular media and other jammed materials such as glasses, foams, and colloids. The hallmark of jammed materials is that they resist applied forces like solids, but are disordered like liquids. In addition, many jammed materials possess heterogeneous, ramified structures known as force chain networks when external forces are applied. Although the existence of force chains has been known for decades, a quantitative understanding of their role in physical processes has proved elusive in part because previous studies have been unable to devise an unbiased and general definition for them. Precise identification and characterization of force chains and the response of jammed materials to applied forces will likely have a transformative impact in many arenas. For example, financial and energy costs of handling and processing of granular materials, typically with high inefficiency, is estimated to be at least one trillion dollars in the US alone. Also, avalanches and earthquakes are examples where the unpredictable behavior of granular media detrimentally impacts mankind. In this work, we will apply novel mathematical techniques coupled with computer simulations and experiments to obtain a quantitative, predictive description of jammed materials. The outreach efforts of this project emphasize providing educational opportunities to students from underrepresented groups. We will organize education and recruiting trips to predominantly female liberal arts colleges in the Northeast and historically black schools in North Carolina, such as North Carolina Central University, and others in the Southeast. These trips will include giving technical and popular lectures, including demonstrations to show that research on jammed materials is intriguing and important. During informal meetings with students we will emphasize that careers in science and technology are rewarding and open to those in underrepresented groups. To stimulate further student interest in this research, we will hold biannual 2-day lab open houses so that promising undergraduates can be exposed to both experimental and theoretical aspects of our research. To encourage close collaboration among researchers in the field of jammed materials, we will organize biannual interdisciplinary workshops. The inaugural workshop, ``Computational Homology Tools Applied to Jamming and Flow in Granular Materials'' is scheduled for the winter of 2009.