Next-Gen CT for environmental sciences

我们建议收购最先进的下一代X射线计算机断层扫描(CT)扫描仪。它将被安置在霍斯菲尔德设施，这是诺丁汉大学(UON)的一个专门从事环境科学的CT中心。与任何可比系统相比，该系统将有几个重大进步(除了同步加速器设施外，科学界不容易获得这些设施，特别是在对同一样本进行数周或数月扫描的时间序列研究中)。新功能包括i)改进的对比度分辨率，使我们能够检测样品中的特征，例如土壤有机碳，由于类似的X射线衰减为研究开辟了新的可能性；ii)更快的扫描时间(约1-2分钟，而不是约60分钟)，使我们能够进行几乎“实时”的成像，如土壤中的溶质传输；以及iii)集成的自动样品加载系统，允许非小时扫描，以增加样品吞吐量。该仪器将具有广泛的跨学科吸引力，因为其主要输出是基于X射线衰减/密度的未受干扰材料的3D可视化/模型，其中的关键特征(例如根、碳、水等)。可以通过附带的图像分析软件进行量化。特别重点将是解决与土壤安全有关的问题，特别是与当前气候紧急情况有关的问题。英国政府的25年环境计划确定了在全国范围内改善土壤健康从而提高土壤安全的必要性。最近下议院关于土壤健康的审计指出，健康的土壤对粮食生产和人类福祉都很重要。英国大部分土壤退化，有机质迅速逐渐流失，导致土壤质量下降，释放破坏性温室气体，许多生态系统服务(如生物多样性、碳储存、粮食生产、养分循环)的提供处于次优状态。我们将使用新的扫描仪对重要的土壤机制有一个新的理解。例如，我们将开发一种新的方法来可视化和测量土壤团聚体中的有机碳，以提供关于碳在土壤中的储存方式的新见解，支持生成预测碳损失对气候变化的作用的新模型，以及能够被土地所有者广泛采用的政策相关解决方案，以加强土壤中的碳固存。此外，我们将探索耐旱植物的潜力，以操纵根际(即紧密附着在根部的土壤)，以改善土壤的水分保持能力，并赋予对日益极端的天气事件的抵抗力。通过提供接触更广泛的NERC社区，特别是早期职业科学家，在我们设施的专家的全面培训计划的支持下，我们寻求在环境科学中使用X射线成像方面的领先地位。

We propose the acquisition of a state of the art, next generation X-ray Computed Tomography (CT) scanner. This will be housed at the Hounsfield Facility, a centre dedicated to CT for the environmental sciences at the University of Nottingham (UoN). The system will have several significant advances on any comparable system (outside of a synchrotron facility which are not readily available to the scientific community especially for time series studies where the same sample is scanned over weeks or months). New functionality includes i) improved contrast resolution allowing us to detect features in samples, such as soil organic carbon, that are currently 'invisible' due to similar X-ray attenuation opening new possibilities for research; ii) faster scan times (c. 1-2 mins compared to c. 60 mins) enabling us to undertake almost 'real-time' imaging such as solute transport in soil; & iii) an integrated automated sample loading system allowing out of hours scanning to increase the sample throughput. The instrument will have wide interdisciplinary appeal as the primary output is 3D visualisation/models of undisturbed materials based on X-ray attenuation/density in which key features (e.g. roots, carbon, water etc.) can be quantified via accompanying image analysis software. The particular focus will be addressing issues concerned with soil security especially those associated with the current climate emergency. The UK Government's 25 Year Environment Plan identified the need to improve soil health and thus soil security across the nation. The recent House of Commons audit on soil health stated 'Healthy soils are important for food production and human wellbeing'. Most soils in the UK are degraded and suffering a rapid and progressive loss of organic matter, leading to a decline in soil quality, release of damaging greenhouse gases and the sub-optimal delivery of many ecosystem services (e.g. biodiversity, carbon storage, food production, nutrient cycling). We will use the new scanner to develop a new understanding for important soil mechanisms. For example, we will develop a new method to visualise and measure organic carbon in soil aggregates to provide a new insight into how carbon is stored in soil, supporting the generation of new models to predict the role of carbon loss on climate change and policy-relevant solutions capable of widespread adoption by land-owners for enhancing carbon sequestration in soil. In addition, we will explore the potential of drought tolerant plants to manipulate the rhizosphere (i.e. the soils closely adhering to roots) to improve water retention in soil and confer a resistance to the increasingly extreme weather events. By offering access to the wider NERC community, and in particular early career scientists, supported by a comprehensive training programme by experts at our facility, we seek to lead on the use of X-ray imaging in the environmental sciences.