Presidential Young Investigator Award: Ionic Transport in Molten and Glassy Silicates

这笔赠款启动资金的主要 总统青年调查员奖。 到目前为止， PI获得了18，000美元的石油研究基金奖 有资格获得NSF匹配基金（美国化学学会， 石油研究基金 1987年）。 因此，本项下提供了43 000美元的资金， 行动（25，000美元的基本奖励加上18，000美元的匹配 资金）。 PI的工作涉及离子和运输的研究 具有地质和地球物理意义的材料的性质。 目前正在通过几种途径进行调查。 直接 频率相关交流阻抗的测定 高温下的两相系统（晶体-熔体系统）和 压力将导致模型结合纹理 参数和频率的理论公式， 多相系统的体阻抗。 从地理位置上看，这些 结果将在表征方面具有重要意义， 浅层地热异常和解释 上地幔电导率异常与热异常 以及上地幔的物理状态 另外的实验 用来测定 含挥发分的熔体在升高的P和T。 测定 挥发物，特别是H.2O和CO.2，对离子 输运不仅在地质问题中具有重要意义， 岩浆的形成、上升和喷发， 科学和陶瓷工程方面的腐蚀和 耐候性 一种新型的实验结合了 电化学诱导迁移示踪剂扩散研究 熔体中挥发物的研究。 这些研究将使 化学离子迁移全系列的测定 平衡和同位素交换参数 系统.

This grant initiates funding for the principal investigator's Presidential Young Investigator award. To date, the PI has received a Petroleum Research Fund Award of $18,000 that qualifies for NSF matching funds (American Chemical Society, Petroleum Research Fund, Grant 1987). Accordingly, $43,000 in funds are provided in this action ($25,000 for the base award plus $18,000 in matching funds). The PI`s work involves studies of ionic and transport properties of materials of geological and geophysical interest. Several avenues of investigation are being pursued. Direct determination of the frequency-dependent AC impedance of two-phase systems (crystal-melt systems) at high temperatures and pressures will lead to models incorporating both textural parameters and frequency into the theoretical formulations of bulk impedance of multiphase systems. Geophysically, these results will be significant in terms of characterization of shallow geothermal anomalies and in terms of interpretation of upper mantle electrical conductivity anomalies and the thermal and physical state of the upper mantle. Additional experiments are being developed to determine electrical conductivities of volatile-bearing melts at elevated P and T. Determination of the effects of volatiles, especially H.2O and CO.2, on ionic transport is of significance not only in the geological problems of magma formation, ascent, and eruption, but also in materials science and ceramic engineering in terms of corrosion and weathering resistance. A novel type of experiment combines tracer diffusion studies with electrochemically-induced migration studies of volatiles in melts. These studies will enable determination of the complete array of ionic transport, chemical equilibrium, and isotopic exchange parameters in melt-volatile systems.