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Hitoshi
Soyama
,
Xiaoyu
Liang
,
Wataru
Yashiro
,
Kentaro
Kajiwara
,
Eleni Myrto
Asimakopoulou
,
Valerio
Bellucci
,
Sarlota
Birnsteinova
,
Gabriele
Giovanetti
,
Chan
Kim
,
Henry J.
Kirkwood
,
Jayanath C. P.
Koliyadu
,
Romain
Letrun
,
Yuhe
Zhang
,
Jozef
Ulicny
,
Richard
Bean
,
Adrian P.
Mancuso
,
Pablo
Villanueva-Perez
,
Tokushi
Sato
,
Patrik
Vagovic
,
Daniel
Eakins
,
Alexander M.
Korsunsky
Open Access
Abstract: Hydrodynamic cavitation is useful in many processing applications, for example, in chemical reactors, water treatment and biochemical engineering. An important type of hydrodynamic cavitation that occurs in a Venturi tube is vortex cavitation known to cause luminescence whose intensity is closely related to the size and number of cavitation events. However, the mechanistic origins of bubbles constituting vortex cavitation remains unclear, although it has been concluded that the pressure fields generated by the cavitation collapse strongly depends on the bubble geometry. The common view is that vortex cavitation consists of numerous small spherical bubbles. In the present paper, aspects of vortex cavitation arising in a Venturi tube were visualized using high-speed X-ray imaging at SPring-8 and European XFEL. It was discovered that vortex cavitation in a Venturi tube consisted of angulated rather than spherical bubbles. The tangential velocity of the surface of vortex cavitation was assessed considering the Rankine vortex model.
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Dec 2023
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[34009, 32463]
Open Access
Abstract: Metal-organic frameworks (MOFs) have emerged as a versatile material platform for a wide range of applications. However, the development of practical devices is constrained by their inherently low mechanical stability. The synthesis of MOFs in a monolithic morphology represents a viable way for the transition of these materials from laboratory research to real-world applications. For the design of MOF-based devices, the mechanical characterization of such materials cannot be overlooked. In this regard, stress-strain relationships represent the most valuable tool for assessing the mechanical response of materials. Here, we use flat punch nanoindentation, micropillar compression and Raman microspectroscopy to investigate the stress-strain behaviour of MOF monoliths. A pseudo-plastic flow is observed under indentation, where the confining pressure prevents unstable crack propagation. Material flow is accommodated by grain boundary sliding, with occasional stepwise cracking to accommodate excessive stress building up. Micropillar compression reveals a brittle failure of ZIF-8, while plastic flow is observed for MIL-68.
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Oct 2023
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B16-Test Beamline
I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[30460, 31917]
Open Access
Abstract: The formation of residual stresses is inevitable during the additive manufacturing of metallic parts due to thermo-mechanicals effects, but the chaotic nature of printing processes makes it impossible to have a comprehensive understanding about the magnitude and distribution of these residuals. The voxel-based eigenstrain (inherent strain) reconstruction method is capable of the full-field reconstruction of residual stresses in discontinuous processing bodies at a scale that depends on the resolution of experimental data without using simplifying assumptions and regularisation functions. This advanced method firstly maps the distribution of eigenstrains and then quantifies corresponding residual stresses, residual elastic strains, and displacements by a cost-effective linear elastic computational framework. The reliability of this process solely depends on the quality of experimental data and the availability of computational power. The motivation behind this study is the use of the voxel-based eigenstrain reconstruction method for the full-field mapping of complex residual stress fields, that cannot be predicted by regularizing assumptions, in discontinuous processing additive manufacturing parts. The height Digital Image Correlation (hDIC) technique satisfied the need for high-quality experimental data by calculating triaxial displacements, corresponding to the elastic response of CM 247 LC powder bed fusion (PBF) additive manufacturing part after changes in the boundary conditions due to separation from the base, using optical profilometry measurements at a resolution adjusted in a way to reconstruct Type I residual stresses. Three components of displacements calculated by the hDIC were used to map the distribution of three components of eigenstrains for the reconstruction of six residual stress, six residual elastic strain and three displacement components that belong to the before and after separating from the base states. The reliability of calculations has been validated by monochromatic synchrotron X-ray beams in powder diffraction mode from the same surface of optical profilometry measurements and in transmission mode from the sampling volumes.
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Sep 2023
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E01-JEM ARM 200CF
I08-1-Soft X-ray Ptychography
I13-2-Diamond Manchester Imaging
I14-Hard X-ray Nanoprobe
I18-Microfocus Spectroscopy
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Cyril
Besnard
,
Ali
Marie
,
Sisini
Sasidharan
,
Petr
Buček
,
Jessica M.
Walker
,
Julia E.
Parker
,
Matthew C.
Spink
,
Robert A.
Harper
,
Shashidhara
Marathe
,
Kaz
Wanelik
,
Thomas E. J.
Moxham
,
Enrico
Salvati
,
Konstantin
Ignatyev
,
Michal M.
Klosowski
,
Richard M.
Shelton
,
Gabriel
Landini
,
Alexander M.
Korsunsky
Diamond Proposal Number(s):
[27749, 30684, 30691, 31005, 29256, 23873]
Open Access
Abstract: Caries, a major global disease associated with dental enamel demineralization, remains insufficiently understood to devise effective prevention or minimally invasive treatment. Understanding the ultrastructural changes in enamel is hampered by a lack of nanoscale characterization of the chemical spatial distributions within the dental tissue. This leads to the requirement to develop techniques based on various characterization methods. The purpose of the present study is to demonstrate the strength of analytic methods using a correlative technique on a single sample of human dental enamel as a specific case study to test the accuracy of techniques to compare regions in enamel. The science of the different techniques is integrated to genuinely study the enamel. The hierarchical structures within carious tissue were mapped using the combination of focused ion beam scanning electron microscopy with synchrotron X-ray tomography. The chemical changes were studied using scanning X-ray fluorescence (XRF) and X-ray wide-angle and small-angle scattering using a beam size below 80 nm for ångström and nanometer length scales. The analysis of XRF intensity gradients revealed subtle variations of Ca intensity in carious samples in comparison with those of normal mature enamel. In addition, the pathways for enamel rod demineralization were studied using X-ray ptychography. The results show the chemical and structural modification in carious enamel with differing locations. These results reinforce the need for multi-modal approaches to nanoscale analysis in complex hierarchically structured materials to interpret the changes of materials. The approach establishes a meticulous correlative characterization platform for the analysis of biomineralized tissues at the nanoscale, which adds confidence in the interpretation of the results and time-saving imaging techniques. The protocol demonstrated here using the dental tissue sample can be applied to other samples for statistical study and the investigation of nanoscale structural changes. The information gathered from the combination of methods could not be obtained with traditional individual techniques.
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Jul 2023
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[25756]
Open Access
Abstract: Caries is a chronic disease that causes the alteration of the structure of dental tissues by acid dissolution (in enamel, dentine and cementum) and proteolytic degradation (dentine and cementum) and generates an important cost of care. There is a need to visualise and characterise the acid dissolution process on enamel due to its hierarchical structure leading to complex structural modifications. The process starts at the enamel surface and progresses into depth, which necessitates the study of the internal enamel structure. Artificial demineralisation is usually employed to simulate the process experimentally. In the present study, the demineralisation of human enamel was studied using surface analysis carried out with atomic force microscopy as well as 3D internal analysis using synchrotron X-ray tomography during acid exposure with repeated scans to generate a time-lapse visualisation sequence. Two-dimensional analysis from projections and virtual slices and 3D analysis of the enamel mass provided details of tissue changes at the level of the rods and inter-rod substance. In addition to the visualisation of structural modifications, the rate of dissolution was determined, which demonstrated the feasibility and usefulness of these techniques. The temporal analysis of enamel demineralisation is not limited to dissolution and can be applied to other experimental conditions for the analysis of treated enamel or remineralisation.
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May 2023
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B16-Test Beamline
DIAD-Dual Imaging and Diffraction Beamline
E01-JEM ARM 200CF
E02-JEM ARM 300CF
I08-Scanning X-ray Microscopy beamline (SXM)
I12-JEEP: Joint Engineering, Environmental and Processing
I13-1-Coherence
I13-2-Diamond Manchester Imaging
I14-Hard X-ray Nanoprobe
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Open Access
Abstract: Hard dental tissues possess a complex hierarchical structure that is particularly evident in enamel, the most mineralised substance in the human body. Its complex and interlinked organisation at the Ångstrom (crystal lattice), nano-, micro-, and macro-scales is the result of evolutionary optimisation for mechanical and functional performance: hardness and stiffness, fracture toughness, thermal, and chemical resistance. Understanding the physical–chemical–structural relationships at each scale requires the application of appropriately sensitive and resolving probes. Synchrotron X-ray techniques offer the possibility to progress significantly beyond the capabilities of conventional laboratory instruments, i.e., X-ray diffractometers, and electron and atomic force microscopes. The last few decades have witnessed the accumulation of results obtained from X-ray scattering (diffraction), spectroscopy (including polarisation analysis), and imaging (including ptychography and tomography). The current article presents a multi-disciplinary review of nearly 40 years of discoveries and advancements, primarily pertaining to the study of enamel and its demineralisation (caries), but also linked to the investigations of other mineralised tissues such as dentine, bone, etc. The modelling approaches informed by these observations are also overviewed. The strategic aim of the present review was to identify and evaluate prospective avenues for analysing dental tissues and developing treatments and prophylaxis for improved dental health.
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Apr 2023
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I12-JEEP: Joint Engineering, Environmental and Processing
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Yuanbo T.
Tang
,
Chinnapat
Panwisawas
,
Benjamin M.
Jenkins
,
Junliang
Liu
,
Zhao
Shen
,
Enrico
Salvati
,
Yilun
Gong
,
Joseph N.
Ghoussoub
,
Stefan
Michalik
,
Bryan
Roebuck
,
Paul A. J.
Bagot
,
Sergio
Lozano-Perez
,
Chris R. M.
Grovenor
,
Michael P.
Moody
,
Alexander M.
Korsunsky
,
David M.
Collins
,
Roger C.
Reed
Diamond Proposal Number(s):
[23674]
Open Access
Abstract: A supersaturated phase microstructure is produced in Ni-based superalloys using laser powder bed fusion (L-PBF) – the cooling rate arising from the process is shown to suppress the solid-state precipitation of the phase. The response of the material to a heat treatment therefore requires new understanding at the fundamental level, since the first population of precipitate forms upon heating, in contrast to cooling from homogenisation above the solvus. Here, we have interrogated two new nickel-based superalloys designed for the L-PBF technology, both in situ and ex situ, at multiple length scales using advanced characterisation methods. First, we conducted in situ synchrotron X-ray diffraction during various heat treatments to trace the evolution of the volume fraction with temperature. The first structural changes were detected at an unexpectedly low temperature of 445 °C. Second, the temperature for nucleation and its sensitivity to heating rate was studied using an electrical resistivity method. Then, the composition upon heating, isothermal holding and cooling is analysed using atom probe tomography (APT), the result is rationalised by further scanning-transmission electron microscopy and nanoscale secondary ion mass spectroscopy. Finally, static recrystallisation during isothermal exposure was investigated, which occurs within minutes. This work sheds light on a new strategy of tailoring microstructure for additively manufactured superalloys by manipulation of the precipitate distribution upon heating.
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Jan 2023
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Accelerator Physics
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Vladimir A.
Chernov
,
Ivan A.
Bataev
,
Yakov V.
Rakshun
,
Yuri V.
Khomyakov
,
Maksim V.
Gorbachev
,
Andrei E.
Trebushinin
,
Nikolay I.
Chkhalo
,
Dmitry A.
Krasnorutskiy
,
Viktor S.
Naumkin
,
Artem N.
Sklyarov
,
Nikolay A.
Mezentsev
,
Alexander M.
Korsunsky
,
Igor P.
Dolbnya
Abstract: Over the next decade, the extremely brilliant fourth generation synchrotron radiation sources are set to become a key driving force in materials characterization and technology development. In this study, we present a conceptual design of a versatile “Materia” diffraction and imaging beamline for a low-emittance synchrotron radiation facility. The beamline was optimized for operation with three main principal delivery regimes: parallel collimated beam ∼1 mm beam size, micro-focus regime with ∼10 μm beam spot size on the sample, and nano-focus regime with <100 nm focus. All regimes will operate in the photon energy range of 10–30 keV with the key feature of the beamline being fast switching between them, as well as between the various realizations of diffraction and imaging operation modes while maintaining the target beam position at the sample, and with both spectrally narrow and spectrally broad beams up to the energy band ΔE/E of 5 × 10−2. The manuscript presents the details of the principal characteristics selected for the insertion device and beamline optics, the materials characterization techniques, including the simulations of thermal load impact on the critical beamline optics components. Significant efforts were made to design the monochromators to mitigate the very high beam power load produced by a superconducting undulator source. The manuscript will be of interest to research groups involved in the design of new synchrotron beamlines.
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Jan 2023
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|
I08-1-Soft X-ray Ptychography
I14-Hard X-ray Nanoprobe
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Cyril
Besnard
,
Ali
Marie
,
Sisini
Sasidharan
,
Petr
Buček
,
Jessica
Walker
,
Julia E.
Parker
,
Thomas E. J.
Moxham
,
Benedikt
Daurer
,
Burkhard
Kaulich
,
Majid
Kazemian
,
Richard M.
Shelton
,
Gabriel
Landini
,
Alexander M.
Korsunsky
Diamond Proposal Number(s):
[30684, 31005]
Open Access
Abstract: This study reports the characterisation of human dental enamel caries using synchrotron nanoscale correlative ptychography and spectroscopic mapping in combination with scanning electron microscopy. A lamella ̴2.4 µm thick was extracted from a carious enamel region of a tooth using focused ion beam-scanning electron microscopy and transferred to two synchrotron beamlines to perform hard X-ray nano-fluorescence spectroscopy simultaneously with differential phase contrast mapping at a beam size of 50 nm. Soft X-ray ptychography data was then reconstructed with a pixel size of 8 nm. The two dimensional variation in chemistry and structure of carious enamel was revealed at the nanoscale, namely, the organisation of hydroxyapatite nano-crystals within enamel rods was imaged together with the inter-rod region. Correlative use of electron and X-ray scanning microscopies for the same sample allowed visualisation of the connection between structure and composition as presented in a compound image where colour indicates the relative calcium concentration in the sample, as indicated by the calcium Kα fluorescence intensity and grey scale shows the nanostructure. This highlights the importance of advanced correlative imaging to investigate the complex structure-composition relationships in nanomaterials of natural or artificial origin.
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Oct 2022
|
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E01-JEM ARM 200CF
I13-2-Diamond Manchester Imaging
|
Diamond Proposal Number(s):
[29256, 30666]
Open Access
Abstract: Dental caries is a widespread disease that damages teeth by heterogeneous dissolution. Conventional histology identifies different zones within carious lesions by their optical appearance, but fails to quantify the underlying nanoscale structural changes as a function of specific location, impeding better understanding of the demineralisation process. We employ detailed collocative analysis using different imaging modalities, resolutions and fields of view. Focused ion beam-scanning electron microscopy (FIB-SEM) reveals subsurface 3D nanostructure within milled micro-sized volumes, whilst X-ray tomography allows less destructive 3D imaging over large volumes. Correlative combination of these techniques reveals fine detail of enamel rods, inter-rod substance, sheaths, crystallites and voids as a function of location. The degree of enamel demineralisation within the body of the lesion, near its front, and at the surface is visualized in 3D. We thus establish the paradigm of dental 3D nano-histology as an advanced platform for quantitative evaluation of caries-induced structural modification.
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Jun 2022
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