I13-1-Coherence
I13-2-Diamond Manchester Imaging
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Abstract: The I13 imaging and coherence beamline aims for multiscale imaging in the energy range of 6-30keV. The achievable resolution ranges from several microns to tens of nanometers. Several experimental methods are available on two independently operating branchlines. The Diamond-Manchester imaging branchline applies methods in direct space, such as In-line phase contrast, grating interferometry and full-field microscopy. The coherence branch covers far-field techniques such as ptychography and Bragg-CDI. The ptychography is now available as user-friendly experiment and the spatial and temporal resolution has been significantly enhanced. The scientific program at I13 will increasingly explore the suite of experimental techniques available at the beamline for multi-scale imaging.
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Jan 2019
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[16497]
Open Access
Abstract: Digital volume correlation (DVC), combined with in situ synchrotron microcomputed tomography (SR-microCT) mechanics, allows for 3D full-field strain measurement in bone at the tissue level. However, long exposures to SR radiation are known to induce bone damage, and reliable experimental protocols able to preserve tissue properties are still lacking. This study aims to propose a proof-of-concept methodology to retain bone tissue integrity, based on residual strain determination using DVC, by decreasing the environmental temperature during in situ SR-microCT testing. Compact and trabecular bone specimens underwent five consecutive full tomographic data collections either at room temperature or 0 °C. Lowering the temperature seemed to reduce microdamage in trabecular bone but had minimal effect on compact bone. A consistent temperature gradient was measured at each exposure period, and its prolonged effect over time may induce localised collagen denaturation and subsequent damage. DVC provided useful information on irradiation-induced microcrack initiation and propagation. Future work is necessary to apply these findings to in situ SR-microCT mechanical tests, and to establish protocols aiming to minimise the SR irradiation-induced damage of bone.
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Nov 2018
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I13-2-Diamond Manchester Imaging
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Julia
Lopez-guimet
,
Lucía
Peña-pérez
,
Robert S.
Bradley
,
Patricia
García-canadilla
,
Catherine
Disney
,
Hua
Geng
,
Andrew J.
Bodey
,
Philip J.
Withers
,
Bart
Bijnens
,
Michael J.
Sherratt
,
Gustavo
Egea
Open Access
Abstract: Aortic wall remodelling is a key feature of both ageing and genetic connective tissue diseases, which are associated with vasculopathies such as Marfan syndrome (MFS). Although the aorta is a 3D structure, little attention has been paid to volumetric assessment, primarily due to the limitations of conventional imaging techniques. Phase-contrast microCT is an emerging imaging technique, which is able to resolve the 3D micro-scale structure of large samples without the need for staining or sectioning.
Methods: Here, we have used synchrotron-based phase-contrast microCT to image aortae of wild type (WT) and MFS Fbn1C1039G/+ mice aged 3, 6 and 9 months old (n=5). We have also developed a new computational approach to automatically measure key histological parameters.
Results: This analysis revealed that WT mice undergo age-dependent aortic remodelling characterised by increases in ascending aorta diameter, tunica media thickness and cross-sectional area. The MFS aortic wall was subject to comparable remodelling, but the magnitudes of the changes were significantly exacerbated, particularly in 9 month-old MFS mice with ascending aorta wall dilations. Moreover, this morphological remodelling in MFS aorta included internal elastic lamina surface breaks that extended throughout the MFS ascending aorta and were already evident in animals who had not yet developed aneurysms.
Conclusions: Our 3D microCT study of the sub-micron wall structure of whole, intact aorta reveals that histological remodelling of the tunica media in MFS could be viewed as an accelerated ageing process, and that phase-contrast microCT combined with computational image analysis allows the visualisation and quantification of 3D morphological remodelling in large volumes of unstained vascular tissues.
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Nov 2018
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[12538, 14907]
Open Access
Abstract: Synchrotron radiation microtomography (SRμCT) is a nominally non-destructive 3D imaging technique which can visualise the internal structures of whole soft tissues. As a multi-stage technique, the cumulative benefits of optimising sample preparation, scanning parameters and signal processing can improve SRμCT imaging efficiency, image quality, accuracy and ultimately, data utility. By evaluating different sample preparations (embedding media, tissue stains), imaging (projection number, propagation distance) and reconstruction (artefact correction, phase retrieval) parameters, a novel methodology (combining reversible iodine stain, wax embedding and inline phase contrast) was optimised for fast (~12 minutes), high-resolution (3.2–4.8 μm diameter capillaries resolved) imaging of the full diameter of a 3.5 mm length of rat spinal cord. White-grey matter macro-features and micro-features such as motoneurons and capillary-level vasculature could then be completely segmented from the imaged volume for analysis through the shallow machine learning SuRVoS Workbench. Imaged spinal cord tissue was preserved for subsequent histology, establishing a complementary SRμCT methodology that can be applied to study spinal cord pathologies or other nervous system tissues such as ganglia, nerves and brain. Further, our ‘single-scan iterative downsampling’ approach and side-by-side comparisons of mounting options, sample stains and phase contrast parameters should inform efficient, effective future soft tissue SRμCT experiment design.
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Aug 2018
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I13-1-Coherence
I13-2-Diamond Manchester Imaging
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Christoph
Rau
,
Malte
Storm
,
Shashidhara
Marathe
,
Andrew J.
Bodey
,
Silvia
Cipiccia
,
Darren
Batey
,
Xiaowen
Shi
,
Marie-christine
Zdora
,
Irene
Zanette
,
Saul
Perez-tamarit
,
Paula
Cimavilla
,
Miguel A.
Rodriguez-perez
,
Florian
Doring
,
Christian
David
Abstract: The Diamond I13 imaging and coherence beamline performs multiscale imaging and tomography with phase sensitive imaging methods. Operating in the energy range of 6-30keV, the achievable resolution ranges from several microns to tens of nanometers. The beamline is unique in combining imaging methods in real and reciprocal spaces, which are available on two independently operating branchlines. The scientific program is currently being developed with the distinct capabilities offered by the beamline. Most recently ptycho-tomography has become operational and a multitude of scientific projects is linking the research between both branchlines.
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Aug 2018
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I12-JEEP: Joint Engineering, Environmental and Processing
I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[13641, 15250]
Abstract: Laser-matter interactions in laser additive manufacturing (LAM) occur on short time scales (10-6 - 10-3 s) and have traditionally proven difficult to characterise. We investigate these interactions during LAM of stainless steel (SS316 L) and 13-93 bioactive glass powders using a custom built LAM process replicator (LAMPR) with in situ and operando synchrotron X-ray radiography. This reveals a range of melt track solidification phenomena as well as spatter and porosity formation. We hypothesise that the SS316 L powder absorbs the laser energy at its surface while the trace elements in the 13-93 bioactive glass powder absorb the laser energy by radiation conduction. Our results show that a low viscosity melt, e.g. 8 mPa s for SS316 L, tends to generate spatter with a diameter up to 250 µm and an average spatter velocity of 0.26 m s-1 and form a melt track by molten pool wetting. In contrast, a high viscosity melt, e.g. 2 Pa s for 13-93 bioactive glass, inhibits spatter formation by damping the Marangoni convection, forming a melt track via viscous flow. The viscous flow in 13-93 bioactive glass resists pore transport; combined with the reboil effect, this promotes pore growth during LAM, resulting in a pore size up to 500 times larger than that exhibited in the SS316 L sample.
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Aug 2018
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[14080]
Abstract: The use of synchrotron radiation micro-computed tomography (SR-microCT) is becoming increasingly popular for studying the relationship between microstructure and bone mechanics subjected to in situ mechanical testing. However, it is well known that the effect of SR X-ray radiation can considerably alter the mechanical properties of bone tissue. Digital volume correlation (DVC) has been extensively used to compute full-field strain distributions in bone specimens subjected to step-wise mechanical loading, but tissue damage from sequential SR-microCT scans has not been previously addressed. Therefore, the aim of this study is to examine the influence of SR irradiation-induced microdamage on the apparent elastic properties of trabecular bone using DVC applied to in situ SR-microCT tomograms obtained with different exposure times. Results showed how DVC was able to identify high local strain levels (>10,000 µε) corresponding to visible microcracks at high irradiation doses (~230 kGy), despite the apparent elastic properties remained unaltered. Microcracks were not detected and bone plasticity was preserved for low irradiation doses (~33 kGy), although image quality and consequently, DVC performance were reduced. DVC results suggested some local deterioration of tissue that might have resulted from mechanical strain concentration further enhanced by some level of local irradiation even for low accumulated dose.
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Aug 2018
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I13-2-Diamond Manchester Imaging
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C. M.
Cady
,
D. E.
Eastwood
,
N. K.
Bourne
,
C.
Liu
,
R.
Pei
,
P.
Mummery
,
W.
Bodel
,
J.
Wade
,
R.
Krishna
,
S.
Cipiccia
,
A, J,
Bodey
,
K.
Wanelik
,
C.
Rau
Diamond Proposal Number(s):
[14356]
Abstract: The motivation of this work is to derive a means of monitoring the structural integrity of components used in nuclear power plants since there are a diverse range of materials, under variable loading, with a range of prior loading histories under complex environmental conditions. An experimental technique has been developed to characterize brittle materials which, using linear elastic fracture mechanics, has given accurate measurements of the global quantity fracture toughness. Here we extend this geometry to X-ray measurements in order to track the crack front as a function of loading parameters as well as to determine the crack surface area as loads increase. We have applied these advances to fracture in beryllium, to determine the onset of damage within the target as strain increases. Further, visualization of crack front advance and the correlated strain fields that are generated during the experiments, have allowed determination of the fracture surface generated as a function of load. This accurate tracking of the micromechanics controlling the energy balance in dynamic failure will provide a vital step in validating multiscale predictive modelling. By these means we aim to produce a micro-and mesoscale justification for macroscale concepts such as KIC.
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Jul 2018
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I13-2-Diamond Manchester Imaging
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Hari
Arora
,
Alex
Nila
,
Kalpani
Vitharana
,
Joseph M.
Sherwood
,
Thuy-tien N.
Nguyen
,
Angelo
Karunaratne
,
Idris K.
Mohammed
,
Andrew J.
Bodey
,
Peter J.
Hellyer
,
Darryl R.
Overby
,
Robert C.
Schroter
,
Dave
Hollis
Diamond Proposal Number(s):
[12864]
Open Access
Abstract: This study focuses on microstructural changes that occur within the mammalian lung when subject to blast and how these changes influence strain distributions within the tissue. Shock tube experiments were performed to generate the blast injured specimens (cadaveric Sprague-Dawley rats). Blast overpressures of 100 and 180 kPa were studied. Synchrotron tomography imaging was used to capture volumetric image data of lungs. Specimens were ventilated using a custom-built system to study multiple inflation pressures during each tomography scan. These data enabled the first digital volume correlation (DVC) measurements in lung tissue to be performed. Quantitative analysis was performed to describe the damaged architecture of the lung. No clear changes in the microstructure of the tissue morphology were observed due to controlled low- to moderate-level blast exposure. However, significant focal sites of injury were observed using DVC, which allowed the detection of bias and concentration in the patterns of strain level. Morphological analysis corroborated the findings, illustrating that the focal damage caused by a blast can give rise to diffuse influence across the tissue. It is important to characterize the non-instantly fatal doses of blast, given the transient nature of blast lung in the clinical setting. This research has highlighted the need for better understanding of focal injury and its zone of influence (alveolar interdependency and neighboring tissue burden as a result of focal injury). DVC techniques show great promise as a tool to advance this endeavor, providing a new perspective on lung mechanics after blast.
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Dec 2017
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[12776]
Open Access
Abstract: Intervertebral disc degeneration (IVDD) is linked to low back pain. Microstructural changes during degeneration have previously been imaged using 2D sectioning techniques and 3D methods which are limited to small specimens and prone to inducing artefacts from sample preparation. This study explores micro computed X-ray tomography (microCT) methods with the aim of resolving IVD 3D microstructure whilst minimising sample preparation artefacts. Low X-ray absorption contrast in non-mineralised tissue can be enhanced using staining and phase contrast techniques. A step-wise approach, including comparing three stains, was used to develop microCT for bovine tail IVD using laboratory and synchrotron sources. Staining successfully contrasted collagenous structures; however not all regions were stained and the procedure induced macroscopic structural changes. Phase contrast microCT of chemically fixed yet unstained samples resolved the nucleus pulposus, annulus fibrosus and constituent lamellae, and finer structures including collagen bundles and cross-bridges. Using the same imaging methods native tissue scans were of slightly lower contrast but free from sample processing artefacts. In the future these methods may be used to characterise structural remodelling in soft (non-calcified) tissues and to conduct in situ studies of native loaded tissues and constructs to characterise their 3D mechanical properties.
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Nov 2017
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