In situ mechanical loading and neutron Bragg-edge imaging, applied to polygranular graphite on IMAT@ISIS

Background Bragg edge imaging have seen significant developments in the last decade with the availability of new time-resolved detectors, however, there have been no studies of changes in local coherent scattering from grain reorientation and deformation with load. Such damage accommodation mechanism may occur in (quasi)-brittle materials. Objective We developed a novel method using in-situ Bragg imaging at the ISIS spallation neutron and muon source on the IMAT (Imaging and MATerials science and engineering) instrument using an energy-resolved detector setup. We collected and analysed data of a proof-of-concept experiment demonstrating the use of the method. Methods We have developed a loading apparatus that addresses the constraints posed by Bragg imaging, allowing us to resolve features in the material microstructure. We use energy-resolved neutron imaging to obtain images in energy bins and we have developed a set of codes to register and correlate these images, as well as detect changes in local coherent scattering, in situ. Results Preliminary results from this method on Gilsocarbon nuclear graphite allow qualitative observation of local changes in Bragg contrast, which may be due to deformation or grain reorientation. Conclusions We have demonstrated that we can track changes in local coherent scattering under mechanical load, with sufficient resolution to track features with a size above 100 microns. This method, apparatus and accompanying codes may be used on the IMAT instruments by users interested to better understand deformation in their materials

The Dutch Apollo 11 Goodwill display contains genuine Moon rocks

Data supporting the publication of the article titled "The Dutch Apollo 11 Goodwill display contains genuine Moon rocks" (https://doi.org/10.1038/s43247-024-01961-z) in Nature Communications Earth and Environment.MoonMatExp: Matlab data for hyperspectralScan D: tomosynthesis scanner databaseClusterTA: raw spectral datasetMR A11_tomo-A: low resolution tomography projectionsMR A11_tomo-B_NORM_REAL: high-resolution tomography projections (pre-processed

In situ measurement of elastic and total strains during ambient and high temperature deformation of a polygranular graphite

In situ neutron diffraction and synchrotron X-ray diffraction, combined with image correlation analysis of 2D optical and 3D X-ray tomography datasets, have been used to investigate the relationship between elastic lattice strain and total strain during deformation of Gilsocarbon (IM1-24) polygranular nuclear grade graphite. The specimens were flat-end Brazilian discs under diametral loading, such that a compressive-tensile biaxial stress state was developed in the central region. The X-ray study was at ambient temperature, and the neutron diffraction was conducted at temperatures from ambient to 850 °C. When under compression, there is a temperature-insensitive linear relationship between the total strain and the lattice strain that is measured perpendicular to the graphite basal planes. However, when under tensile stress, the total strain and elastic strain relationship is temperature sensitive: below 600 °C, the lattice tensile strain saturates with increasing total tensile strain; above 600 °C, significantly higher tensile lattice strains are sustained. The saturation in tensile lattice strain is attributed to microcracking in the graphite microstructure. Improved resistance to microcracking and damage tolerance at elevated temperature explains the increase in tensile strength of polygranular graphite.</p

In situ observation of crystal reorientation in polygranular graphite by synchrotron X-ray diffraction and neutron imaging

The capacity of polygranular graphite to accommodate strain is important to its use within structural components. This study has used in situ neutron and synchrotron X-ray experiments to demonstrate that reorientation of crystal domains accompanies the accommodation of applied mechanical strain in unirradiated Gilsocarbon (GCMB/IM24) graphite. Orientation changes were observed using 3D X-ray Diffraction, and local changes in neutron scattering were also observed with energy-resolved Bragg-edge neutron imaging. In both cases, this behaviour at the crystal level was partially recovered when the load was removed. This study provides new evidence for crystal deformation mechanisms that contribute to polycrystalline graphite's elastic non-linearity and the development of permanent set, which may also explain the effects of fast neutron irradiation on graphite elastic behaviour

The Dutch Apollo 11 Goodwill display contains genuine Moon rocks

Abstract In the 1970s, US President Richard Nixon offered moon samples returned by the Apollo 11 and Apollo 17 missions to the leaders of the nations of the World. In this study, we used a combination of advanced X-ray analysis methods, including microtomography, tomosynthesis and hyperspectral chemical mapping to carry out a non-destructive forensic investigation of the Dutch Apollo 11 Goodwill sample, normally on display at the Boerhaave museum in the Netherlands. These powerful methods were uniquely able to non-destructively interrogate the samples encased in plastic without contact, providing 3D images of sample textures and compositional analysis, to assess whether the results agree with archive data on Apollo 11 coarse-grained soil sample number 10085, and to provide new insights on their origins. Our forensic investigation asked the question: were the rocks in the Dutch display actually picked up on the surface of the moon by Neil Armstrong and Buzz Aldrin

The r-evolution of school based occupational therapy (SBOT) through international collaboration and innovation

Rationale/background: Inclusive, occupation-based, educationally-relevant occupational therapy in schools has been advocated for internationally by the World Federation of Occupational Therapists (WFOT). However, school based occupational therapy (SBOT) provision varies worldwide, depending on a country’s legislative and financial support. Although well-established in some countries, SBOT remains an emerging practice area in others, requiring innovation and advocacy. With a commitment to the R-evolution of SBOT, an international network of OTs was established at the 2018 WFOT Congress. Within this community of practice (CoP), participants have shared innovative practice and research on the R-evolution of SBOT. This workshop will continue to build this CoP through knowledge translation and networking. Learning objectives: Participants will - Describe innovative SBOT from perspective of 13 countries, focusing on successful student participation in occupations across all school environments; - Describe a multi-tiered continuum of services model, emphasizing Tier 1, universal promotion for all; Tier 2, targeted prevention for students at-risk; Tier 3, individualized intervention for students with identified challenges (Response to Intervention, Partnering for Change, and public health approach to mental health); - Discuss challenges, needs, and innovative strategies in SBOT internationally; - Participate in SBOT International Network to advance SBOT in their country post-conference

The r-evolution of school based occupational therapy (SBOT) through international collaboration and innovation

Rationale/background: Inclusive, occupation-based, educationally-relevant occupational therapy in schools has been advocated for internationally by the World Federation of Occupational Therapists (WFOT). However, school based occupational therapy (SBOT) provision varies worldwide, depending on a country’s legislative and financial support. Although well-established in some countries, SBOT remains an emerging practice area in others, requiring innovation and advocacy. With a commitment to the R-evolution of SBOT, an international network of OTs was established at the 2018 WFOT Congress. Within this community of practice (CoP), participants have shared innovative practice and research on the R-evolution of SBOT. This workshop will continue to build this CoP through knowledge translation and networking. Learning objectives: Participants will - Describe innovative SBOT from perspective of 13 countries, focusing on successful student participation in occupations across all school environments; - Describe a multi-tiered continuum of services model, emphasizing Tier 1, universal promotion for all; Tier 2, targeted prevention for students at-risk; Tier 3, individualized intervention for students with identified challenges (Response to Intervention, Partnering for Change, and public health approach to mental health); - Discuss challenges, needs, and innovative strategies in SBOT internationally; - Participate in SBOT International Network to advance SBOT in their country post-conference

Tensile failure mechanisms of historic fibrous plaster ceiling wads: Experiments at the UK Diamond Light Source

Fibrous plaster (FP) ceilings, prevalent in late 19th- and early 20th-century UK theatres, are suspended using ‘wads’. Wads are hangers made of Plaster of Paris, reinforced with twisted woven jute fabric. Several recent collapses in historic fibrous plaster ceilings have been attributed to tensile failures in wads. To understand the failure mechanisms involved, tensile tests were performed on laboratory-produced wad-like samples at the I12 beamline of the UK Diamond Light Source. The tested samples were designed with a dog bone shape and mounted with clevis-grips at each end, to ensure controlled failures along the gauge length. The beamline offered the opportunity to conduct simultaneous synchrotron X-ray computed tomography (sCT) and diffraction measurements during loading, enabling the monitoring of internal crack formation and strain propagation at the microstructural scale. Simultaneously, acoustic emission (AE) and digital image correlation (DIC) measurements were conducted. Preliminary results from these datasets are discussed in this paper. The datasets will provide useful information to validate the ongoing development of algorithms which can categorise the internal failure mechanisms and damage state of wads using only AE signals