MRI: Acquisition of an X-ray Diffraction Instrument: Developing an Interdisciplinary Research/Teaching X-ray Diffraction Laboratory

加州州立大学弗雷斯诺分校是加州州立大学系统中最大的大学之一，也是加州中央山谷地区唯一一所著名的大学。因此，我们肩负着培养科学家和解决区域环境问题的社会责任。此次主要研究仪器（MRI）拨款将获得粉末x射线衍射（XRD）仪器，该仪器将支持许多涉及细颗粒材料鉴定的科学问题，包括但不限于以下内容：1)内华达山脉中北部的区域地质和火山历史。填图和初步XRD研究表明，火山岩中基质矿物丰度是火山单元对比和确定与现侵蚀喷口距离的关键。2) Sierra foothills和coastal CA的石棉矿物。超镁铁质岩石在CA普遍存在，角闪洞群的石棉矿物在挖掘和商业开发过程中形成有害粉尘。x射线衍射（XRD）将用于正在施工的此类区域的危害评估。3)火成岩气压测定及斜生辉石单细胞参数的细化。天然斜辉石的Rietveld分析将用于更好地理解Na在天然斜辉石中是如何电荷平衡的，并通过这种方式改进我们估计火成岩结晶压力的尝试。4)通过分析矿物含量来研究土壤力学、地下水流动和土壤污染。粘土矿物和石膏的丰度被怀疑会影响农业土壤的水文，也可能影响土壤对污染物的吸收；农业样品的XRD分析将是了解水和污染物迁移的关键。5)对奶制品生产过程中产生的粉尘颗粒进行分析。粉尘颗粒（有时以微米大小称为PM-5或PM-10）现在被认为是加利福尼亚州的重大健康危害。奶牛场被怀疑是粉尘颗粒的重要生产者，但其数量和矿物质含量尚不清楚。对奶牛场收集的粉尘进行XRD分析，可以确定产生了哪种粉尘颗粒，以及此类操作所产生的粉尘占总粉尘的比例。最后，我们的粉末XRD将为CSU Fresno和CSU Stanislaus的本科生提供宝贵的研究经验。当学生参与研究时，当这些工作涉及到技术工具的使用时，他们就会被科学所吸引。基本的XRD技术非常容易学习，并且允许本科生和硕士学生参与中央山谷居民非常关注的任何数量的问题。XRD活动将被纳入CSUF现有的几门课程中，包括一门新课程：“材料科学中的x射线方法”。此次仪器收购的更广泛影响也相当可观。XRD将在科罗拉多州立大学弗雷斯诺分校至少三个不同的系之间，以及科罗拉多州立大学弗雷斯诺分校的地球与环境科学系与科罗拉多州立大学斯坦尼斯劳斯分校的“物理与地质”系之间建立几个令人兴奋的研究联系。获得所需的XRD仪器对于进一步提高我们的研究能力和实现我们的招生目标至关重要

0421272PutirkaThe California State University, Fresno is one of the largest universities in the CSU system, and the only prominent university in California's Central Valley. As such, we carry a responsibility to the community to train scientists and address regional environmental problems. The powder X-ray diffraction (XRD) instrument that will be acquired with this Major Research Instrumentation (MRI) grant will support a number of scientific problems that involve the identification of fine-grained materials, including, but not limited to, the following: 1) Regional geology and volcanic history of the north-central Sierra Nevada. Mapping and preliminary XRD studies suggest that matrix mineral abundances in volcanic rocks can be key to the correlation of volcanic units and the identification of distance from now-eroded vents. 2) Asbestiform minerals in the Sierra foothills and coastal CA. Ultramafic rocks are common throughout CA, and asbestiform minerals of the amphibole group form hazardous dusts during excavation and commercial development. XRD will be used for hazards assessment where construction of such areas is ongoing. 3) Igneous barometery and the refinement of unit cell parameters of clinopyroxenes. Rietveld analysis of natural clinopyroxenes will be used to better understand how Na is charge-balanced in natural clinopyroxenes, and in this way refine our attempts at estimate crystallization pressures for igneous rocks. 4) The study of soil mechanics, groundwater flow and soil contamination through the analysis mineral content. Abundances of clay minerals and gypsum are suspected to affect the hydrology of agricultural soils, and may also affect the absorption of contaminants in soils; XRD analysis of agricultural samples will be key to understanding water and contaminant transport. 5) The analysis of dust particles produced from dairy operations. Dust particles (sometimes referred to by their micron size as PM-5 or PM-10) are now recognized as a significant health hazard in CA. Dairies are suspected to be significant producers of dust particles, but their quantity and mineral content is unclear. XRD analysis of dusts collected at dairies will allow a determination of what kinds of dust particles are created, and the fraction of the total dust contributed by such operations. Finally, our powder XRD will provide valuable research experiences for CSU Fresno and CSU Stanislaus undergraduates. Students are attracted to the sciences when they participate in research, and when such work involves the use of technical instruments. Basic XRD techniques are very easy to learn, and allow both undergraduates and M.S. students to participate in any number of problems of great concern to central valley residents. XRD activities will be incorporated into several existing courses at CSUF, including a new course: "X-ray methods in the Material Sciences". The broader impacts of this instrument acquisition are also considerable. The XRD will establish several exciting research linkages between at least three different departments at CSU Fresno, and between the Earth and Environmental Science department at CSU Fresno and the "Physics and Geology" department at CSU Stanislaus. Acquisition of the requested XRD instrument is critical to furthering our research capabilities and realizing our student recruitment goals.***