Search

Key Message: The principal components of tree-ring anatomical chronologies of Scots pine proved to be much better proxy than its tree-ring width for reconstruction of climate-driven component in the regional yield of cereals Tree-ring records are often used as a proxy not only for climate, but also for other related variables. One of such applications is the reconstruction of crop yield, since both are indicators of productivity in the respective ecosystems. Recently, finer parameters of wood structure were applied to enhance the sensitivity and temporal resolution of the registered climatic signal and thus to improve the quality of tree-ring based reconstructions. This pioneering study tests cell-scale quantitative wood anatomy (QWA) of conifer tree species as a proxy for crop yield in the moisture-limited plains of Khakassia (South Siberia). Spring wheat, oats, and barley yield series generalized for rain-fed (north of the region) and irrigated (central part) fields in the steppes were compared with long-term (1807–2018) QWA series of the Scots pine (Pinus sylvestris L.) from the forest-steppe in the foothills. Chronologies of the cell radial diameter and cell wall thickness, describing the tree ring separated into 15 sectors, were obtained and indexed to remove their common exponential dependence on the number of cells per radial row in the ring. The tree-ring width alone could explain only 16.0 and 5.3% of yield variation for rain-fed and irrigated crops, respectively. Whereas, the multifactor linear regressions with stepwise inclusion of QWA chronologies explained 48.4 and 16.1%. The implementation of principal components for QWA in the models further increased the fitness to 48.9 and 23.0%. These reconstructions have climatic responses during the vegetative season similar to ones of the respective actual yield series. The reconstructed history of the low-yield years is supported by documented evidence of crop failures, droughts, and other related events. [ABSTRACT FROM AUTHOR]

Geopolymers are under scrutiny as a sustainable alternative to cement in 3D printing for eco-friendly construction. Geopolymer 3D printing (G3DP) holds promise for green construction and advanced manufacturing. This study addresses G3DP's rheological properties, printability, and microstructure analysis. Results indicate the pivotal role of the rheological properties in the printability, encompassing parameters like the pumpability, extrudability, and shape retention. Lower viscosity and appropriate yield stress are crucial. The structural performance of G3DP, given its inherent anisotropic nature and assessment techniques, is scrutinized. Process variables such as nozzle design and print speed and interval affect the printability, buildability, and structural properties. Research on the parameters' optimization is necessary. Additionally, evaluation techniques for the G3DP's rheological and structural behaviors require standardization. Understanding the G3DP's rheology is paramount for the successful 3D printing construction. Findings offer quantitative insights into the importance of the rheological properties for the printability and structural performance. The microstructural analysis uncovers the porosity and density disparities compared to traditional geopolymers. This comprehensive review provides valuable insights for researchers and practitioners to enhance the G3DP's application as a futuristic sustainable construction material. [ABSTRACT FROM AUTHOR]