CAREER: Statistical Mechanics of Particulate Systems Far from Equilibrium

这一职业奖支持有关乳剂和颗粒介质等颗粒材料“堵塞”系统的理论和计算研究和教育。这些系统本质上远离它们的平衡状态。这项工作旨在测试和进一步发展一个统一的热力学框架，该框架有望导致对具有集体松弛动力学的广泛系统的共同理解。特别是，研究将集中在两个软物质系统：密集堆积的颗粒状物质和高度浓缩的乳状物。如果热力学框架可以描述远离平衡的体系的行为，那么具有真正热力学意义的有效温度就是表征材料性质的关键参数。为了检验这一概念的有效性，PI将进行计算机模拟--在串行和并行体系结构中使用高性能的数值算法--并开发适当的理论基础来描述观察到的行为。PI将测试热力学概念的应用是否可以为理解慢颗粒流变学和非线性弹性现象提供框架。这项工作可能对石油、制药和加工行业以及基础科学产生更广泛的影响，因为它探索了这样一种理论观点，即紧密堆积的颗粒系统的统计系综可能是Gibbs和Boltzmann统计力学应用于非平衡系统的真正推广的例子。教育部分涉及课程开发和创新、吸引和留住代表性不足的少数族裔学生，以及通过教育网站向广大受众传播我们的成果。它需要开发一系列关于现代软物质物理和计算物理主题的跨学科课程，这些课程将与研究计划紧密结合。让本科生和研究生在他们职业生涯的早期就进入研究环境将是这个项目的优先事项。PI将吸引一批来自物理、化学、土木工程和机械工程背景的少数族裔本科生和研究生。%该职业奖支持有关“堵塞”的颗粒材料系统的理论和计算研究和教育，例如乳剂和颗粒介质。在颗粒材料中，如果颗粒堆积在一起，使所有颗粒接触到相邻的颗粒，则会产生“堵塞”系统，如果密度足够高，就有可能出现这种情况。人们假设，经历这种结构停滞状态的系统的行为可以用平衡热力学概念和有效温度的存在来描述，这种状态本质上远离平衡态。这项工作建议测试和进一步开发一个统一的热力学框架，该框架有望导致对广泛系统的共同理解。这项工作可能对石油、制药和加工行业以及基础科学产生更广泛的影响，因为它探索了这样一种理论观点，即紧密堆积的颗粒系统的统计系综可能是Gibbs和Boltzmann统计力学应用于非平衡系统的真正推广的例子。教育部分涉及课程开发和创新、吸引和留住代表性不足的少数族裔学生，以及通过教育网站向广大受众传播我们的成果。它需要开发一系列关于现代软物质物理和计算物理主题的跨学科课程，这些课程将与研究计划紧密结合。让本科生和研究生在他们职业生涯的早期就进入研究环境将是这个项目的优先事项。PI将吸引一批来自物理、化学、土木工程和机械工程背景的少数族裔本科生和研究生。***

This CAREER award supports theoretical and computational research and education on "jammed" systems of particulate materials, such as emulsions and granular media. These systems are inherently far from their equilibrium state. This work seeks to test and further develop a unifying thermodynamic framework which promises to lead to a common understanding of a wide range of systems with collective relaxation dynamics. In particular, study will focus on two soft-matter systems: densely packed granular matter and highly concentrated emulsions. If a thermodynamic framework can describe the behavior of systems far from equilibrium, than an effective temperature with a true thermodynamic meaning exists as a key parameter in characterizing the material's properties. In order to examine the validity of this concept, the PI will perform computer simulations- using high-performance numerical algorithms in serial and parallel architectures- and develop an appropriate theoretical basis to describe the observed behavior. The PI will test whether the application of thermodynamic concepts may provide the framework for understanding slow granular rheology and nonlinear elastic phenomena. The work has potential broader impacts on the petroleum, pharmaceutical, and processing industries and on fundamental science through the exploration of the theoretical idea that a statistical ensemble for closely packed particulate systems could be an example of a true generalization of the application of statistical mechanics of Gibbs and Boltzmann to systems out of equilibrium. The educational component involves curriculum development and innovation, attraction and retention of underrepresented minority students, and dissemination of our results to a wide audience through an educational web site. It entails the development of a series of interdisciplinary courses on modern, soft-matter physics and computational physics topics, which will be tightly integrated with the research plan. Involving undergraduate and graduate students in research environments early on in their careers will be a priority of this program. The PI will draw an excellent pool of minority undergraduate and graduate students from physics and chemical, civil and mechanical engineering backgrounds. %%%This CAREER award supports theoretical and computational research and education on "jammed" systems of particulate materials, such as emulsions and granular media.In particulate materials, a "jammed" system results if particles are packed together so that all particles are touching their neighbors, a possibility provided the density is sufficiently high. It has been postulated that the behavior of systems experiencing such a state of structural arrest, a state that is inherently far from the equilibrium state, can be described by equilibrium thermodynamic concepts and the existence of an effective temperature. This work proposes to test and further develop a unifying thermodynamic framework which promises to lead to a common understanding of a wide range of systems. The work has potential broader impacts on the petroleum, pharmaceutical, and processing industries and on fundamental science through the exploration of the theoretical idea that a statistical ensemble for closely packed particulate systems could be an example of a true generalization of the application of statistical mechanics of Gibbs and Boltzmann to systems out of equilibrium. The educational component involves curriculum development and innovation, attraction and retention of underrepresented minority students, and dissemination of our results to a wide audience through an educational web site. It entails the development of a series of interdisciplinary courses on modern, soft-matter physics and computational physics topics, which will be tightly integrated with the research plan. Involving undergraduate and graduate students in research environments early on in their careers will be a priority of this program. The PI will draw an excellent pool of minority undergraduate and graduate students from physics and chemical, civil and mechanical engineering backgrounds. ***