I12-JEEP: Joint Engineering, Environmental and Processing
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A.
Koko
,
S.
Singh
,
S.
Barhli
,
T.
Connolley
,
N. T.
Vo
,
T.
Wigger
,
D.
Liu
,
Y.
Fu
,
J.
Réthoré
,
J.
Lechambre
,
J.-Y.
Buffiere
,
T. J.
Marrow
Diamond Proposal Number(s):
[12585]
Open Access
Abstract: The propagation rate of a fatigue crack in a nodular cast iron, loaded in cyclic tension, has been studied in situ by X-ray computed tomography and digital volume correlation. The semi-elliptical crack initiated from an asymmetric corner notch and evolved to a semi-circular shape, initially with a higher growth rate towards one edge of the notch before the propagation rate along the crack front became essentially independent of po-sition. The phase congruency of the displacement field was used to measure the crack shape. The three-dimensional stress intensity factors were calculated via a linear elastic finite element model that used the displacement fields around the crack front as the boundary conditions. Closure of the crack tip region was observed. The cyclic change in the local mode I opening of the crack tip determined the local fatigue crack propaga-tion rate along the crack front.
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May 2023
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Abstract: Unsaturated solute transport was directly characterized with the use of Synchrotron-based X–ray Computed Tomography (s-XRCT). The spatial and temporal resolutions were 3.25 µm and 6 seconds, respectively.
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Apr 2023
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[19322]
Abstract: In-line phase contrast synchrotron tomography combined with in situ mechanical loading enables the characterisation of soft tissue micromechanics via digital volume correlation (DVC) within whole organs. Optimising scan time is important for reducing radiation dose from multiple scans and to limit sample movement during acquisition. Also, although contrasted edges provided by in-line phase contrast tomography of soft tissues are useful for DVC, the effect of phase contrast imaging on its accuracy has yet to be investigated. Due to limited time at synchrotron facilities, scan parameters are often decided during imaging and their effect on DVC accuracy is not fully understood. Here, we used previously published data of intervertebral disc phase contrast tomography to evaluate the influence of i) fibrous image texture, ii) number of projections, iii) tomographic reconstruction method, and iv) phase contrast propagation distance on DVC results. A greater understanding of how image texture influences optimal DVC tracking was obtained by visualising objective function mapping, enabling tracking inaccuracies to be identified. When reducing the number of projections, DVC was minimally affected by image high frequency noise but with a compromise in accuracy. Iterative reconstruction methods improved image signal-to-noise and consequently significantly lowered DVC displacement uncertainty. Propagation distance was shown to affect DVC accuracy. Consistent DVC results were achieved within a propagation distance range which provided contrast to the smallest scale features, where; too short a distance provided insufficient features to track, whereas too long led to edge effect inconsistencies, particularly at greater deformations. Although limited to a single sample type and image setup, this study provides general guidelines for future investigations when optimising image quality and scan times for in situ phase contrast x-ray tomography of fibrous connective tissues.
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Nov 2022
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B16-Test Beamline
I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[27987, 20763, 27144, 31131]
Abstract: X-ray phase-contrast tomography (X-PCT) techniques are capable of imaging samples with small differences in densities. They enable scientists to study biological or medical samples using high energy X-rays, which means less X-ray absorption and less sample damage, with high contrast quality. One branch of these techniques known as speckle-based methods have been well developed and demonstrated on real applications by different groups of developers using their own codes. However, there is lack of collective effort to package these methods into an open-source software which is easy-to-install, easy-to-use, well-documented, and optimized for speed. Such software is crucial to make the X-PCT techniques accessible to generic users and become regular tools. This report demonstrates the effort which implements speckle-based phase-retrieval methods in Python and GPU.
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Oct 2022
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I12-JEEP: Joint Engineering, Environmental and Processing
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Yongqiang
Chen
,
Holger
Steeb
,
Hamidreza
Erfani
,
Nikolaos K.
Karadimitriou
,
Monika
Walczak
,
Matthias
Ruf
,
Dongwon
Lee
,
Senyou
An
,
Sharul
Hasan
,
Thomas
Connolley
,
Nghia T.
Vo
,
Vahid
Niasar
Diamond Proposal Number(s):
[20072]
Open Access
Abstract: Experimental and field studies reported a significant discrepancy between the cleanup and contamination time scales, while its cause is not yet addressed. Using high-resolution fast synchrotron x-ray computed tomography, we characterized the solute transport in a fully saturated sand packing for both contamination and cleanup processes at similar hydrodynamic conditions. The discrepancy in the time scales has been demonstrated by the nonuniqueness of hydrodynamic dispersion coefficient versus injection rate (Péclet number). Observations show that in the mixed advection-diffusion regime, the hydrodynamic dispersion coefficient of cleanup is significantly larger than that of the contamination process. This nonuniqueness has been attributed to the concentration-dependent diffusion coefficient during the cocurrent and countercurrent advection and diffusion, present in contamination and cleanup processes. The new findings enhance our fundamental understanding of transport processes and improve our capability to estimate the transport time scales of chemicals or pollution in geological and engineering systems.
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Dec 2021
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I12-JEEP: Joint Engineering, Environmental and Processing
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Nolwenn
Le Gall
,
Fabio
Arzilli
,
Giuseppe
La Spina
,
Margherita
Polacci
,
Biao
Cai
,
Margaret E.
Hartley
,
Nghia T.
Vo
,
Robert C.
Atwood
,
Danilo
Di Genova
,
Sara
Nonni
,
Edward W.
Llewellin
,
Mike R.
Burton
,
Peter D.
Lee
Diamond Proposal Number(s):
[12392]
Abstract: Crystallisation is a complex process that significantly affects the rheology of magma, and thus the flow dynamics during a volcanic eruption. For example, the evolution of crystal fraction, size and shape has a strong impact on the surface crust formation of a lava flow, and accessing such information is essential for accurate modelling of lava flow dynamics. To investigate the role of crystallisation kinetics on lava flow behaviour, we performed real-time, in situ synchrotron X-ray microtomography, studying the influence of temperature-time paths on the nucleation and growth of clinopyroxene and plagioclase in an oxidised, nominally anhydrous basaltic magma. Crystallisation experiments were performed at atmospheric pressure in air and temperatures from 1250 °C to 1100 °C, using a bespoke high-temperature resistance furnace. Depending on the cooling regime (single step versus continuous), two different crystal phases (either clinopyroxene or plagioclase) were produced, and we quantified their growth from both global and individual 3D texture analyses. The textural evolution of charges suggests that suppression of crystal nucleation is due to changes in the melt composition with increasing undercooling and time. Using existing viscosity models, we inferred the effect of crystals on the viscosity evolution of our crystal-bearing samples to trace changes in rheological behaviour during lava emplacement. We observe that under continuous cooling, both the onsets of the pāhoehoe-‘a‘ā transition and of non-Newtonian behaviour occur within a shorter time frame. With varying both temperature and time, we also either reproduced or approached the clinopyroxene and plagioclase phenocryst abundances and compositions of the Etna lava used as starting material, demonstrating that real-time synchrotron X-ray tomography is an ideal approach to unravel the final solidification history of basaltic lavas. This imaging technology has indeed the potential to provide input into lava flow models and hence our ability to forecast volcanic hazards.
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Aug 2021
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William
Liu
,
Salida
Mirzoeva
,
Ye
Yuan
,
Junjing
Deng
,
Si
Chen
,
Barry
Lai
,
Stefan
Vogt
,
Karna
Shah
,
Rahul
Shroff
,
Reiner
Bleher
,
Qiaoling
Jin
,
Nghia
Vo
,
Remon
Bazak
,
Carissa
Ritner
,
Stanley
Gutionov
,
Sumita
Raha
,
Julia
Sedlmair
,
Carol
Hirschmugl
,
Chris
Jacobsen
,
Tatjana
Paunesku
,
John
Kalapurkal
,
Gayle E.
Woloschak
Open Access
Abstract: Background: Neuroblastoma is the most common extracranial solid malignancy in childhood which, despite the current progress in radiotherapy and chemotherapy protocols, still has a high mortality rate in high risk tumors. Nanomedicine offers excit- ing and unexploited opportunities to overcome the shortcomings of conventional medicine. The photocatalytic properties of Fe O core-TiO shell nanocomposites and
3 4 2
their potential for cell specific targeting suggest that nanoconstructs produced using
Fe3O4 core-TiO2 shell nanocomposites could be used to enhance radiation effects in neuroblastoma. In this study, we evaluated bare, metaiodobenzylguanidine (MIBG) and 3,4-Dihydroxyphenylacetic acid (DOPAC) coated Fe3O4@TiO2 as potential radiosensitiz- ers for neuroblastoma in vitro.
Results: The uptake of bare and MIBG coated nanocomposites modestly sensitized neuroblastoma cells to ionizing radiation. Conversely, cells exposed to DOPAC coated nanocomposites exhibited a five-fold enhanced sensitivity to radiation, increased numbers of radiation induced DNA double-strand breaks, and apoptotic cell death. The addition of a peptide mimic of the epidermal growth factor (EGF) to nanoconju- gates coated with MIBG altered their intracellular distribution. Cryo X-ray fluorescence microscopy tomography of frozen hydrated cells treated with these nanoconjugates revealed cytoplasmic as well as nuclear distribution of the nanoconstructs.
Conclusions: The intracellular distribution pattern of different nanoconjugates used in this study was different for different nanoconjugate surface molecules. Cells exposed to DOPAC covered nanoconjugates showed the smallest nanoconjugate uptake,
with the most prominent pattern of large intracellular aggregates. Interestingly, cells treated with this nanoconjugate also showed the most pronounced radiosensitiza- tion effect in combination with the external beam x-ray irradiation. Further studies
are necessary to evaluate mechanistic basis for this increased radiosensitization effect. Preliminary studies with the nanoparticles carrying an EGF mimicking peptide showed.
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May 2021
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[22109, 24740, 14033, 19526, 21999]
Open Access
Abstract: Parallel-beam tomography systems at synchrotron facilities have limited field of view (FOV) determined by the available beam size and detector system coverage. Scanning the full size of samples bigger than the FOV requires various data acquisition schemes such as grid scan, 360-degree scan with offset center-of-rotation (COR), helical scan, or combinations of these schemes. Though straightforward to implement, these scanning techniques have not often been used due to the lack of software and methods to process such types of data in an easy and automated fashion. The ease of use and automation is critical at synchrotron facilities where using visual inspection in data processing steps such as image stitching, COR determination, or helical data conversion is impractical due to the large size of datasets. Here, we provide methods and their implementations in a Python package, named Algotom, for not only processing such data types but also with the highest quality possible. The efficiency and ease of use of these tools can help to extend applications of parallel-beam tomography systems.
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May 2021
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[21334]
Open Access
Abstract: Numerous aspects of early hominin biology remain debated or simply unknown. However, recent developments in high-resolution imaging techniques have opened new avenues in the field of paleoanthropology. More specifically, X-ray synchrotron-based analytical imaging techniques have the potential to provide crucial details on the ontogeny, physiology, biomechanics, and biological identity of fossil specimens. Here we present preliminary results of our X-ray synchrotron-based investigation of the skull of the 3.67-million-year-old Australopithecus specimen StW 573 (‘Little Foot’) at the I12 beamline of the Diamond Light Source (United Kingdom). Besides showing fine details of the enamel (i.e., hypoplasias) and cementum (i.e., incremental lines), as well as of the cranial bone microarchitecture (e.g., diploic channels), our synchrotron-based investigation reveals for the first time the 3D spatial organization of the Haversian systems in the mandibular symphysis of an early hominin.
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Mar 2021
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[13704, 18197]
Open Access
Abstract: The torsional performance of bi-axially braided carbon fibre reinforced polymer (CFRP) tubes as a function of braid architecture is investigated. It is found that for a given braid pattern, the 45° braided CFRP tubes have higher shear moduli and lower shear strength than the 35° braids. In general, 2/2 (regular) braided CFRP tubes exhibit both higher shear strength and higher shear modulus than 1/1 (diamond) braids. However, beyond the peak load, the shear strength of 2/2 braided CFRPs exhibits sudden, steep drops, resulting in a lower remnant shear strength than 1/1 structures after the shear strain exceeds 4.5%. Moreover, the damage evolution is monitored in-situ by synchrotron X-ray computed tomography during torsional straining. It showed that for a 2/2 structure, inter-tow debonded regions are vertically interconnected allowing rapid crack propagation and strength drops, whereas for the 1/1 braid they are distributed in a chequer board causing more gradual loss of strength. The fibre/matrix interfacial strength and tow cross-over density play key roles in the torsional failure of 1/1 and 2/2 braided CFRP tubes, as the former controls damage initiation and the latter controls damage propagation.
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Sep 2020
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