I12-JEEP: Joint Engineering, Environmental and Processing
|
Diamond Proposal Number(s):
[22992]
Abstract: Soil structure is one of the most important environmental factors affecting root architectural development and consequently plant yield. Understanding how plant roots respond to soils with variable soil structure is important as it enables soil management practices that promote optimal root growth. Many contemporary, non-invasive experiments investigating how plant root architecture responds to soil structural variations have often focused on compaction, often neglecting the role of soil aggregate size in determining root configuration. To better understand this, in this study, we used non-invasive neutron and X-Ray imaging to investigate how variable aggregate size affects the early root architectural establishment in wheat plants. Sandy loam soil derived macro-aggregates of two distinct sizes (0.25−0.5 and 2−4 mm) were used to infer the suitability of each aggregate size for use in wheat seedbeds. We also grew wheat seedlings in partitioned containers with the two different aggregate size classes filled side by side to establish whether there would be preferential growth of roots in either aggregate size class. Our results showed significantly increased root growth in the smaller 0.25−0.5 mm aggregates as compared to the larger 2−4 mm aggregates. This was mainly as a result of enhanced lateral root growth when the wheat plants were grown in the finer aggregates. On the other hand, coarser aggregates induced significantly increased seminal root axes which partially offset the differences in total root length between the two aggregate sizes. Plants growing in partitioned containers similarly indicated preferential root growth in smaller aggregate with an even more pronounced difference in root growth in the smaller aggregates. As inferred from our results, seedbeds dominated by smaller macro-aggregates (finer soil tilth) may be optimal to enhance wheat seedling root growth in sandy loam soils.
|
Aug 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Diamond Proposal Number(s):
[26476]
Abstract: In this work, three new pharmaceutical salts of fenbendazole (FNB), a benzimidazole-based anthelmintic drug, with sulfonic acids have been obtained and thoroughly investigated by different analytical techniques, including thermal methods, infrared/Raman spectroscopy, and theoretical methods (periodic DFT computations and Bader analyses of the crystalline electronic density). Single-crystal and high-resolution synchrotron powder X-ray diffraction data for the first time made it possible to determine the crystal structures of mesylate and tosylate salts of the drug, which were further validated by dispersion-corrected density functional theory calculations. All the solid forms were stabilized by a robust R22(8) supramolecular motif formed by relatively strong N–H···O hydrogen bonds. In the monohydrate of FNB tosylate, a considerable gain in the stabilization energy was due to the intermolecular interactions generated by the water molecules. A careful examination of the solubility–pH profile of the FNB salts revealed that, despite being thermodynamically unstable within the physiologically relevant pH range, the new solid forms demonstrated superior dissolution performance in terms of both the apparent solubility and the release rate in comparison to the parent drug. Since FNB has also been reported to possess anticancer activity, improving the drug’s poor physicochemical properties through salt formation with the selected sulfonic acids is expected to promote further investigations toward repurposing of this potent compound.
|
Jul 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Diamond Proposal Number(s):
[19235]
Open Access
Abstract: The widespread use and development of inertia friction welding is currently restricted by an incomplete understanding of the deformation mechanisms and microstructure evolution during the process. Understanding phase transformations and lattice strains during inertia friction welding is essential for the development of robust numerical models capable of determining optimized process parameters and reducing the requirement for costly experimental trials. A unique compact rig has been designed and used in-situ with a high-speed synchrotron X-ray diffraction instrument to investigate the microstructure evolution during inertia friction welding of a high-carbon steel (BS1407). At the contact interface, the transformation from ferrite to austenite was captured in great detail, allowing for analysis of the phase fractions during the process. Measurement of the thermal response of the weld reveals that the transformation to austenite occurs 230 °C below the equilibrium start temperature of 725 °C. It is concluded that the localization of large strains around the contact interface produced as the specimens deform assists this non-equilibrium phase transformation.
|
May 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Diamond Proposal Number(s):
[20820]
Open Access
Abstract: Alternative and sustainable waste sources are receiving increasing attention as they can be used to produce biofuels with a low carbon footprint. Waste fish oil is one such example and can be considered an abundant and sustainable waste source to produce biodiesel. Ultimately this could lead to fishing communities having their own "off-grid" source of fuel for boats and vehicles. At the industrial level biodiesel is currently produced by homogeneous catalysis because of the high catalyst activity and selectivity. In contrast, heterogeneous catalysis offers several advantages such as improved reusability, reduced waste and lower processing costs. Here we investigate the phase evolution of two heterogeneous catalysts, CaO and a Ca3Al2O6:CaO ('C3A:CaO') composite, under in-situ conditions for biodiesel production from fish oil. A new reactor was designed to monitor the evolution of the crystalline catalyst during the reaction using synchrotron powder X-ray diffraction (PXRD). The amount of calcium diglyceroxide (CaDG) began to increase rapidly after approximately 30 minutes, for both catalysts. This rapid increase in CaDG could be linked to ex-situ NMR studies which showed that the conversion of fish oil to biodiesel rapidly increased after 30 minutes. The key to the difference in activity of the two catalysts appears to be that the Ca3Al2O6:CaO composite maintains a high rate of calcium diglyceroxide formation for longer than CaO, although the initial formation rates and reaction kinetics are similar. Overall this specialised in-situ set-up has been shown to be suitable to monitor the phase evolution of heterogeneous crystalline catalysts during the triglycerides transesterification reaction, offering the opportunity to correlate the crystalline phases to activity, deactivation and stability.
|
May 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Chi Ming
Yim
,
Soumendra Nath
Panja
,
Christopher
Trainer
,
Craig
Topping
,
Christoph
Heil
,
Alexandra S.
Gibbs
,
Oxana
Magdysyuk
,
Vladimir
Tsurkan
,
Alois
Loidl
,
Andreas W.
Rost
,
Peter
Wahl
Diamond Proposal Number(s):
[22974]
Open Access
Abstract: A key property of many quantum materials is that their ground state depends sensitively on small changes of an external tuning parameter, e.g., doping, magnetic field, or pressure, creating opportunities for potential technological applications. Here, we explore tuning of the ground state of the nonsuperconducting parent compound, Fe1+xTe, of the iron chalcogenides by uniaxial strain. Iron telluride exhibits a peculiar (π, 0) antiferromagnetic order unlike the (π, π) order observed in the Fe-pnictide superconductors. The (π, 0) order is accompanied by a significant monoclinic distortion. We explore tuning of the ground state by uniaxial strain combined with low-temperature scanning tunneling microscopy. We demonstrate that, indeed under strain, the surface of Fe1.1Te undergoes a transition to a (π, π)-charge-ordered state. Comparison with transport experiments on uniaxially strained samples shows that this is a surface phase, demonstrating the opportunities afforded by 2D correlated phases stabilized near surfaces and interfaces.
|
Apr 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Diamond Proposal Number(s):
[19216]
Abstract: High-speed synchrotron tomography was used to investigate the nucleation and growth dynamics of Al13Fe4 intermetallic during solidification of an Al-5wt%Fe alloy, providing new insights into its formation process. The majority of Al13Fe4 intermetallics nucleated near the surface oxide of the specimen and a few nucleated at Al13Fe4 phase. Al13Fe4 crystals grew into a variety of shapes, including plate-like, hexagonal tabular, stair-like and V-shaped, which can be attributed to the crystal structure of this compound and its susceptibility to twinning. Hole-like defects filled with aluminium melt were observed within the intermetallics. Oriented particle attachment mechanism was proposed to explain the formation of the Al13Fe4 intermetallic, which needs further experiments and simulation to confirm.
|
Apr 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Ziyang
Ning
,
Dominic Spencer
Jolly
,
Guanchen
Li
,
Robin
De Meyere
,
Shengda D.
Pu
,
Yang
Chen
,
Jitti
Kasemchainan
,
Johannes
Ihli
,
Chen
Gong
,
Boyang
Liu
,
Dominic L. R.
Melvin
,
Anne
Bonnin
,
Oxana
Magdysyuk
,
Paul
Adamson
,
Gareth O.
Hartley
,
Charles W.
Monroe
,
James
Marrow
,
Peter G.
Bruce
Diamond Proposal Number(s):
[20795]
Abstract: Lithium dendrite (filament) propagation through ceramic electrolytes, leading to short circuits at high rates of charge, is one of the greatest barriers to realizing high-energy-density all-solid-state lithium-anode batteries. Utilizing in situ X-ray computed tomography coupled with spatially mapped X-ray diffraction, the propagation of cracks and the propagation of lithium dendrites through the solid electrolyte have been tracked in a Li/Li6PS5Cl/Li cell as a function of the charge passed. On plating, cracking initiates with spallation, conical ‘pothole’-like cracks that form in the ceramic electrolyte near the surface with the plated electrode. The spallations form predominantly at the lithium electrode edges where local fields are high. Transverse cracks then propagate from the spallations across the electrolyte from the plated to the stripped electrode. Lithium ingress drives the propagation of the spallation and transverse cracks by widening the crack from the rear; that is, the crack front propagates ahead of the Li. As a result, cracks traverse the entire electrolyte before the Li arrives at the other electrode, and therefore before a short circuit occurs.
|
Apr 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Yunhui
Chen
,
Samuel J.
Clark
,
David M.
Collins
,
Sebastian
Marussi
,
Simon A.
Hunt
,
Danielle
Fenech
,
Thomas
Connolley
,
Robert C.
Atwood
,
Oxana V.
Magdysyuk
,
Gavin J.
Baxter
,
Martyn A.
Jones
,
Chu Lun Alex
Leung
,
Peter D.
Lee
Diamond Proposal Number(s):
[20096]
Abstract: The governing mechanistic behaviour of Directed Energy Deposition Additive Manufacturing (DED-AM) is revealed by a combined in situ and operando synchrotron X-ray imaging and diffraction study of a nickel-base superalloy, IN718. Using a unique DAE-AM process replicator, real-space imaging enables quantification of the melt-pool boundary and flow dynamics during solidification. This imaging knowledge was also used to informed precise diffraction measurements of temporally resolved microstructural phases during transformation and stress development with a spatial resolution of 100 µm. The diffraction quantified thermal gradient enabled a dendritic solidification microstructure to be predicted and coupled to the stress orientation and magnitude. The fast cooling rate entirely suppressed the formation of secondary phases or recrystallisation in the solid-state. Upon solidification, the stresses rapidly increase to the yield strength during cooling. This insight, combined with the large solidification range of IN718 suggests that the accumulated plasticity exhausts the ductility of the alloy, causing liquation cracking. This study has revealed additional fundamental mechanisms governing the formation of highly non-equilibrium microstructures during DED-AM.
|
Mar 2021
|
|
I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
|
Kieran W. P.
Orr
,
Sean M.
Collins
,
Emily M.
Reynolds
,
Frank
Nightingale
,
Hanna L. B.
Bostroem
,
Simon J.
Cassidy
,
Daniel M.
Dawson
,
Sharon E.
Ashbrook
,
Oxana
Magdysyuk
,
Paul A.
Midgley
,
Andrew L.
Goodwin
,
Hamish H.-M.
Yeung
Diamond Proposal Number(s):
[20946, 18786]
Open Access
Abstract: Control over the spatial distribution of components in metal–organic frameworks has potential to unlock improved performance and new behaviour in separations, sensing and catalysis. We report an unprecedented single-step synthesis of multi-component metal–organic framework (MOF) nanoparticles based on the canonical ZIF-8 (Zn) system and its Cd analogue, which form with a core–shell structure whose internal interface can be systematically tuned. We use scanning transmission electron microscopy, X-ray energy dispersive spectroscopy and a new composition gradient model to fit high-resolution X-ray diffraction data to show how core–shell composition and interface characteristics are intricately controlled by synthesis temperature and reaction composition. Particle formation is investigated by in situ X-ray diffraction, which reveals that the spatial distribution of components evolves with time and is determined by the interplay of phase stability, crystallisation kinetics and diffusion. This work opens up new possibilities for the control and characterisation of functionality, component distribution and interfaces in MOF-based materials.
|
Feb 2021
|
|
I12-JEEP: Joint Engineering, Environmental and Processing
|
Diamond Proposal Number(s):
[16771]
Open Access
Abstract: An experimental technique is described for the collection of time-resolved X-ray diffraction information from a complete commercial battery cell during discharging or charging cycles. The technique uses an 80 × 80 pixel 2D energy-discriminating detector in a pinhole camera geometry which can be used with a polychromatic X-ray source. The concept was proved in a synchrotron X-ray study of commercial alkaline Zn–MnO2 AA size cells. Importantly, no modification of the cell was required. The technique enabled spatial and temporal changes to be observed with a time resolution of 20 min (5 min of data collection with a 15 min wait between scans). Chemical changes in the cell determined from diffraction information were correlated with complementary X-ray tomography scans performed on similar cells from the same batch. The clearest results were for the spatial and temporal changes in the Zn anode. Spatially, there was a sequential transformation of Zn to ZnO in the direction from the separator towards the current collector. Temporally, it was possible to track the transformation of Zn to ZnO during the discharge and follow the corresponding changes in the cathode.
|
Dec 2020
|
|
