I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[31855]
Open Access
Abstract: Directed energy deposition (DED) laser additive manufacturing (AM) is a promising technique for building complex components and performing repair applications. However, large defects can form through coalescence of argon bubbles from the feedstock powder, potentially reducing end-component mechanical performance. Here, we used correlative high-speed synchrotron X-ray and infrared imaging, coupled with multiphysics modelling to develop a strategy to control defect formation. We demonstrate that the bubble dynamics can be controlled by appropriately modulating the laser power, temporarily disrupting the Marangoni flow, enabling bubble release. The bubble control mechanisms discovered here provide a way to achieve defect-lean AM.
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Sep 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[852, 9811, 10458, 11204]
Open Access
Abstract: Microdefects, including microcracks and resorption trenches, may be important contributors to bone fragility. 3D microdefect morphology was imaged using synchrotron micro-CT to develop a classification system for investigating the relationship with bone mechanics and hip-fractures. Femoral heads from ageing hip-fracture patients (n = 5, 74–82 years) were compared to ageing non-fracture controls (n = 5, 72–84 years). Two trabecular cores were prepared from the chiasma; one was imaged using synchrotron micro-CT to measure microdefects and one was mechanically tested to measure tensile strength. Morphological and mechanical data were compared and correlated using Mann Whitney U test and Pearson’s rank correlation. All the procedures performed were in accordance with the ethical standards of the Imperial College Tissue Bank (R13004) and the 1984 Declaration of Helsinki. Microdefects varied and were classified into four categories based on shape and measurable parameters. Hip-fracture donors exhibited significantly higher density of all microdefects (p < 0.05). Microdefect volume was strongly negatively correlated with ultimate tensile strength (p < 0.05) and stiffness (p < 0.05). Microdefects might contribute to loss of bone strength and fragility fracture via runaway resorption. Microcracks could promote focussed osteoclastic resorption and the formation of resorption pits which create stress risers leading to the re-formation of microcracks under continued load. CT-based classification methods should be used to explore the complex interaction between microdefects, metabolism, and bone fracture mechanics.
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Aug 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Johan
Lindgren
,
Dean R.
Lomax
,
Robert-Zoltán
Szász
,
Miguel
Marx
,
Johan
Revstedt
,
Georg
Göltz
,
Sven
Sachs
,
Randolph G.
De La Garza
,
Miriam
Heingård
,
Martin
Jarenmark
,
Kristina
Ydström
,
Peter
Sjövall
,
Frank
Osbæck
,
Stephen A.
Hall
,
Michiel
Op De Beeck
,
Mats E.
Eriksson
,
Carl
Alwmark
,
Federica
Marone
,
Alexander
Liptak
,
Robert
Atwood
,
Genoveva
Burca
,
Per
Uvdal
,
Per
Persson
,
Dan-Eric
Nilsson
Diamond Proposal Number(s):
[33954]
Open Access
Abstract: With their superficially shark-like appearance, the Mesozoic ichthyosaurs provide a classic illustration of major morphological adaptations in an ancestrally terrestrial tetrapod lineage following the invasion of marine habitats1,2,3. Much of what is known about ichthyosaur soft tissues derives from specimens with body outlines4,5,6. However, despite offering insights into aspects of biology that are otherwise difficult to envisage from skeletal evidence alone (such as the presence of a crescentic fluke), information on their soft parts has hitherto been limited to a taxonomically narrow sample of small- to dolphin-sized animals2,4,5,6. Here we report the discovery of a metre-long front flipper of the large-bodied Jurassic ichthyosaur Temnodontosaurus, including unique details of its soft-tissue anatomy. In addition to revealing a wing-like planform, the fossil preserves a serrated trailing edge that is reinforced by novel cartilaginous integumental elements, herein denominated chondroderms. We also document chordwise-parallel skin ornamentations and a protracted fleshy distal tip that presumably acted like a flexible winglet in life. By integrating morphological and numerical data, we show that the observed features probably provided hydroacoustic benefits, and conclude that the visually guided7,8 Temnodontosaurus relied on stealth while hunting in dim-lit pelagic environments. This unexpected combination of control surface modifications represents a previously unrecognized mode of concealment, and underscores the importance of soft-tissue fossils when inferring aspects of palaeoethology and predator–prey palaeoecology.
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Jul 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Barbara
Bonechi
,
Emily C.
Bamber
,
Margherita
Polacci
,
F.
Arzilli
,
Giuseppe
La Spina
,
Elisa
Biagioli
,
Jorge E.
Romero
,
Jean-Louis
Hazemann
,
Richard
Brooker
,
Robert
Atwood
,
Mike
Burton
Diamond Proposal Number(s):
[31529]
Open Access
Abstract: Investigating the textural properties and 3D geometry of the connected pore network in volcanic products provides insight into magma ascent processes, due to their influence on magma permeability, outgassing efficiency and explosivity. Here, we used X-ray computed microtomography to investigate vesicle textures in tephra from the 2021 Tajogaite eruption (La Palma, Spain) and the relationship between these pore network parameters and eruptive style. We report a 3D dataset of pore network parameters for lapilli clasts collected throughout the eruption, associated with different eruptive styles (ash-rich jets, lava fountains, Strombolian activity). In clasts from Strombolian activity, the lower vesicle number density (VND) and tortuosity factor (m) suggests that there are fewer vesicles and that the channels which connect them are less tortuous than in clasts from fountain and ash-rich jet activity, favouring a lower degree of gas–melt coupling and thus, more efficient outgassing. Instead, for clasts of lava fountain and ash-rich jet activity, the higher VND and m suggest a higher number of vesicles connected by more tortuous channels, promoting some degree of gas–melt coupling and thus, less efficient outgassing. However, in clasts from ash-rich jets, the presence of narrower channels, as suggested by the lower throat-pore size ratio, favours a greater degree of gas–melt coupling with respect to fountain activity, leading to magma fragmentation. This work highlights the importance of textural and pore network analyses in understanding eruption dynamics, and provides a case study for investigating the interplay between pore network parameters, magma permeability and ascent dynamics for low-viscosity magmas.
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Jun 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[26730]
Open Access
Abstract: Hydrogen (H2) storage in porous geological formations offers a promising means to balance supply and demand in the renewable energy sector, supporting the energy transition. Important unknowns to this technology include the H2 fluid flow dynamics through the porous medium which affect H2 injectivity and recovery. We used time-resolved X-ray computed microtomography to image real-time unsteady and steady state injections of H2 and brine (2 M KI) into a Clashach sandstone core at 5 MPa and ambient temperature. In steady state injections, H2 entered the brine-saturated rock within seconds, dispersing over several discrete pores. Over time, some H2 ganglia connected, disconnected and then reconnected from each other (intermittent flow), indicating that the current presumption of a constant connected flow pathway during multiphase fluid flow is an oversimplification. Pressure oscillations at the sample outlet were characterized as red noise, supporting observations of intermittent pore-filling. At higher H2 fractional flow the H2 saturation in the pore space increased from 20-22 % to 28 %. Average Euler characteristics were generally positive over time at all H2 flow fractions, indicating poorly connected H2 clusters and little control of connectivity on the H2 saturation. In unsteady state injections, H2 displaced brine in sudden pore-filling events termed Haines jumps, which are key to understanding fluid dynamics in porous media. Our results suggest a lower H2 storage capacity in sandstone aquifers with higher injection-induced hydrodynamic flow and suggest a low H2 recovery. For more accurate predictions of H2 storage potential and recovery, geological models should incorporate energy-dissipating processes such as Haines jumps.
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Apr 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[30413]
Abstract: The migration and deposition of fine particles in porous materials is critical in industries such as energy, pharmaceuticals, and environmental engineering. Using 3D time-lapse synchrotron X-ray imaging, we observe fine particles invading porous media, analyzing the effects of pore size and heterogeneity at both pore and macro scales. Glass beads model homogeneous and heterogeneous conditions, revealing a sequence of deposition processes: surface attachment, throat bridging, blocking, pore filling, compaction, and migration. A critical throat-to-particle size ratio of 1.7 governs deposition behavior. At the macro-scale, heterogeneities like beddings and flow pathways influence fines migration and deposition. Based on dynamic 3D imaging, we propose a mechanism for fines behavior in heterogeneous porous media. These findings enhance understanding of fines migration, offering a predictive framework for managing formation damage and optimizing filter cake design in drilling and clean energy applications.
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Mar 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[37256]
Open Access
Abstract: he high brilliance and coherence of light generated at synchrotron facilities make synchrotron X-ray imaging an invaluable tool for the non-destructive analysis of samples across a range of interdisciplinary sciences. For samples with low attenuation contrast, phase-contrast imaging and phase-retrieval techniques can be used to enhance image contrast and provide complementary phase-shift information. In this work, we demonstrate the phase-contrast imaging capabilities of the Diamond Light Source I12-JEEP beamline using two samples: a fly encased in 4 mm of steel, and a lower chicken leg (drumstick) bones with surrounding soft tissue. Techniques such as X-ray phase-contrast imaging, near-field speckle-based phase-contrast tomography and propagation-based (in-line) phase-contrast tomography are investigated; additionally, the effects of propagation distance, speckle mask material, number of speckle positions, and phase-retrieval algorithm on the quality of radiographic images and reconstructed tomography volumes are compared. The experimental setup, data acquisition settings, as well as phase retrieval and tomography reconstruction parameters are detailed, and concluding remarks are made regarding the strengths and weaknesses of each technique, their use case, and how the data acquisition parameters can be optimised for an extended field-of-view or in-situ imaging setup available at I12.
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Jan 2025
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I12-JEEP: Joint Engineering, Environmental and Processing
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Barbara
Bonechi
,
Margherita
Polacci
,
Fabio
Arzilli
,
Giuseppe
La Spina
,
Jean-Louis
Hazemann
,
Richard A.
Brooker
,
Robert
Atwood
,
Sebastian
Marussi
,
Peter D.
Lee
,
Roy A.
Wogelius
,
Jonathan
Fellowes
,
Mike R.
Burton
Diamond Proposal Number(s):
[28538]
Open Access
Abstract: Transitions in eruptive style during volcanic eruptions strongly depend on how easily gas and magma decouple during ascent. Stronger gas-melt coupling favors highly explosive eruptions, whereas weaker coupling promotes lava fountaining and lava flows. The mechanisms producing these transitions are still poorly understood because of a lack of direct observations of bubble dynamics under natural magmatic conditions. Here, we combine x-ray radiography with a novel high-pressure/high-temperature apparatus to observe and quantify in real-time bubble growth and coalescence in basaltic magmas from 100 megapascals to surface. For low-viscosity magmas, bubbles coalesce and recover a spherical shape within 3 seconds, implying that, for lava fountaining activity, gas and melt remain coupled during the ascent up to the last hundred meters of the conduit. For higher-viscosity magmas, recovery times become longer, promoting connected bubble pathways. This apparatus opens frontiers in unraveling magmatic/volcanic processes, leading to improved hazard assessment and risk mitigation.
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Aug 2024
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I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
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Kay
Song
,
Guanze
He
,
Abdallah
Reza
,
Tamas
Ungar
,
Phani
Karamched
,
David
Yang
,
Ivan
Tolkachev
,
Kenichiro
Mizohata
,
Stephen P.
Thompson
,
Eamonn T.
Connolly
,
Robert C.
Atwood
,
Stefan
Michalik
,
David E. J.
Armstrong
,
Felix
Hofmann
Diamond Proposal Number(s):
[28444, 32094]
Open Access
Abstract: Severe plastic deformation changes the microstructure and properties of steels, which may be favourable for their use in structural components of nuclear reactors. In this study, high-pressure torsion (HPT) was used to refine the grain structure of Eurofer-97, a ferritic/martensitic steel. Electron microscopy and X-ray diffraction were used to characterise the microstructural changes. Following HPT at room temperature to a maximum shear strain of 230, the average grain size reduced by a factor of ~30, with a marked increase in high-angle grain boundaries. Dislocation density also increased by more than one order of magnitude. The thermal stability of the deformed material was investigated via in-situ annealing during synchrotron X-ray diffraction. This revealed substantial recovery between 450 K – 800 K. Irradiation with 20 MeV Fe-ions to ~0.1 dpa caused a 20% reduction in dislocation density compared to the as-deformed material. However, HPT deformation prior to irradiation only had a minor effect in mitigating the irradiation-induced reductions in thermal diffusivity and surface acoustic wave velocity of the material. Microstructural and material property changes are dominated by deformation compared to irradiation. In light of this, the benefits of using HPT to improve the irradiation resistance of Eurofer-97 are limited. These results provide a multi-faceted view of the changes in ferritic/martensitic steels due to severe plastic deformation, and how these changes can be used to alter material properties.
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Jul 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
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Lorna
Sinclair
,
Oliver
Hatt
,
Samuel J.
Clark
,
Sebastian
Marussi
,
Elena
Ruckh
,
Robert C.
Atwood
,
Martyn
Jones
,
Gavin J.
Baxter
,
Chu Lun Alex
Leung
,
Iain
Todd
,
Peter D.
Lee
Diamond Proposal Number(s):
[20096]
Open Access
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Jul 2024
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