Browsing by Author "Bevitt, JJ"
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- ItemThe 1st ANSTO-AINSE Workshop on Nuclear Techniques for Cultural Heritage(Taylor & Francis Online, 2019-05-24) Salvemini, F; White, R; McIntyre, GJ; Bevitt, JJ; Cubbin, KNo abstract available.
- ItemCultural heritage project at Australian Nuclear Science and Technology Organisation (ANSTO)(Springer Nature, 2022-01-25) Salvemini, F; White, R; Levchenko, VA; Smith, AM; Pastuovic, Z; Stopic, A; Luzin, V; Tobin, MJ; Puskar, L; Howard, DL; Davis, J; Avdeev, M; Gatenby, S; Kim, MJ; Grazzi, F; Sheedy, K; Olsen, SR; Raymond, CA; Lord, C; Richards, C; Bevitt, JJ; Popelka-Filcoff, RS; Lenehan, CE; Ives, S; Dredge, P; Yip, A; Brookhouse, MT; Austin, AGThe Australian Nuclear Science and Technology Organization (ANSTO) is the home of Australia’s most significant landmark and national infrastructure for research. ANSTO operates one of the world’s most modern nuclear research reactors, OPAL; a comprehensive suite of neutron beam instruments; the Australian Synchrotron; the Electron Microscope Facility; and the Center for Accelerator Science. Over the years, the suite of nuclear methods available across ANSTO’s campuses has been increasingly applied to study a wide range of heritage materials. Since 2015 the strategic research project on cultural heritage was initiated in order to promote access to ANSTO’s capabilities and expertise, unique in the region, by cultural institution and researchers. This chapter offers a compendium of ANSTO nuclear capabilities most frequently applied to cultural heritage research. A series of innovative, interdisciplinary, and multi-technique studies conducted in close collaboration with Australian museums, institutions, and universities is also showcased. It includes research on dating Aboriginal Australian rock art and fingerprinting the sources of ochre pigments; rediscovering the technological knowledge in the making of early coinage and ancient weapons; virtually unwrapping the content of votive mummies from ancient Egypt; and investigating and restoring the original layer of a painting that can be explored by the museum audience in a novel type of exhibition based on an immersive, interactive, and virtual environment. © 2022 Springer Nature Switzerland AG
- ItemGuest adsorption in the nanoporous metal–organic framework Cu3(1,3,5-benzenetricarboxylate)2: combined in situ x-ray diffraction and vapor sorption(American Chemical Society, 2014-07-23) Peterson, VK; Southon, PD; Halder, GJ; Price, DJ; Bevitt, JJ; Kepert, CJThe structure of the nanoporous metal–organic framework Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylate) with a variety of molecular guests was studied in situ using single crystal X-ray diffraction. By collecting crystal structure data for a series of guests within the same host crystal, insights into the molecular interactions underpinning guest adsorption processes have been gained. Adsorption behaviors are influenced strongly by both enthalpic and entropic thermodynamic, as well as interpore steric (size-exclusion) effects, and we note correlations between guest attributes and these effects. Vapor adsorption measurements revealed a guest uptake capacity inversely proportional to guest size. Correspondingly, structural results show that guests reside in the smallest pores accessible to them. Interpore steric effects for larger guests cause these to be excluded from the smallest pores, and this corresponds to lower total uptake. Both hydrophilic and lipophilic small guests adsorb favorably into the 5 Å diameter smallest pore of the material, with the number of guests in these pores dependent on guest size and their location, in turn dependent upon both guest–guest interactions and competition between hydrogen-bonding interactions at the apertures of the smallest pore and lipophilic interactions at the center of the smallest pore. Hydrophilic guests with lone electron pairs interact preferentially with the coordinatively unsaturated Cu sites of the desolvated framework, with the number of these depending on steric interactions between neighboring bound guests and guest flexibility. Guest coordination at the Cu sites has a significant effect on the framework structure, increasing the Cu···Cu distance in the dinuclear unit, with the Cu3(BTC)2 unit cell being smaller when guests that do not coordinate with the Cu are present, and in the case of cyclohexane, smaller than for the desolvated framework. Overall, our comprehensive structural study reconciles Cu3(BTC)2 adsorption properties with the underlying guest–host and guest–guest interactions that gives rise to these. © 2014, American Chemical Society.
- ItemHow to take a perfect image with DINGO(Australian Nuclear Science and Technology Organisation, 2021-11-24) Grigorova, V; Clark, SM; Bevitt, JJNeutron tomography is a powerful non-destructive technique used to study the internal structure of opaque objects. Neutron images are obtained by exposing an object to a uniform neutron beam. The transmitted neutrons interact with a phosphor which converts from neutrons to visible light, which is then demagnified on to a CCD camera. The modulation transfer function (MTF) is routinely used to determine the sharpness of an image, i.e. the ability of the imaging system to transfer information from an object to an image. The spatial frequency (SF) is the rate of transition between light and dark features in the image. For a perfect system where all of the frequency information is passed from object to image equally, the MTF of the will be 1 or 100% for all spatial frequencies and all features and contrast in the object will be transferred to the image. We performed a series of measurements to optimise the time necessary to obtain high-resolution radiographs with the DINGO instrument. We determined the MTF over a range of experimental conditions to understand the various contributions of DINGO’s imaging system variables to radiograph resolution. The system components varied in this study are the two beam modes, different scintillator screens, and pixel resolution of different cameras and lenses. We also compared the different exposure times of the object to the neutron beam to try to understand the minimum exposure time that will generate good resolution radiographs. Details of the use of this method for determining the quality of a neutron tomographic imaging system will be presented and the MTF data will be used to determine the optimal operating arrangement. © 2021 The Authors
- ItemNeutron imaging: benefits and case studies in palaeontology and cutlural heritage(Australian Institute of Nuclear Science and Engineering (AINSE), 2020-11-11) Bevitt, JJ; Gabre, U; Salvemini, F; Raymond, CConventional and synchrotron-based X-ray computed tomography (XCT) have been utilised for many years as critical tools in uncovering 3-D internal and surface renderings of scientifically important fossils, cultural artefacts and other specimens held in museum and university collections. DINGO, Australia’s thermal-neutron micro-computed tomography (nCT) instrument, is being used to obtain unpreceded renderings of extraordinary fossilised anatomical features not visible with conventional imaging techniques, and yielding new insights into ancient manufacturing methods of archaeological artefacts not attainable by other methods. NCT is a complementary tool to XCT, and it is important to recognise the benefits, and challenges with its application. Using a selection of case studies from our instrument user program, this presentation will illustrate how neutrons are revealing soft-tissue remains in Jurassic stem-mammals, being used to identify touch-ups and fraud in palaeontology, and providing new insights into Cretaceous polar ecosystems. Through the ANSTO supported Cultural Heritage project, neutron imaging is being used to reveal ancient weapons manufacturing practices, reveal hidden texts in a lead scroll and identify the recycling of mummified votive offerings in ancient Egypt. Improvements in imaging technology and methods at ANSTO is enabling us to achieve higher throughput of these precious objects, minimise neutron-induced activation of samples and to support an increasing number and diversity of student-led research projects.
- ItemNeutron micro-CT as a non-destructive tool for palaeontology(Australian Institute of Nuclear Science and Engineering, 2016-11-29) Bevitt, JJThe physical extraction of fossilised remains from rocks enables quantitative physiological investigation of bone-dimensions, volume, and porosity, however leads to the destruction of valuable contextual information and soft-tissue remains within the matrix. Conventional and synchrotron-based X-ray computed tomography (XCT) have been utilised for many years as critical tools in uncovering valuable 3-D internal and surface renderings of scientifically important fossils, however poor contrast and X-ray penetration often prevents thorough tomographic analysis. DINGO, Australia’s first and only neutron micro-computed tomography (nCT) instrument is located at the OPAL nuclear research reactor. It is being used to obtain unpreceded reconstructions of extraordinary fossilised anatomical features not visible with conventional imaging techniques. This presentation will outline the physical capabilities of DINGO, the limitations and results to-date in the field of palaeontology. Drawing upon specimens scanned from across Australia, Antarctica, New Zealand, China and Mongolia, this presentation will demonstrate the complementarity of nCT to classic XCT methods, and its limitations. Evidence of extraordinary soft-tissue fossilisation in Jurassic fauna will be shown, along with insights into ancient and modern-day animals, achieved through the use of neutron CT scanning.
- ItemNeutron micro-CT as a non-destructive tool for palaeontology in Australia(Australian Institute of Nuclear Science and Engineering (AINSE), 2018-11-18) Bevitt, JJThe physical extraction of fossilised remains from rocks enables quantitative physiological investi gation of bonedimensions,volume, and porosity, however leads to the destruction of valuable con textual information and soft-tissue remains within the matrix. Conventional and synchrotron-based X-ray computed tomography (XCT) have been utilised for many years as critical tools in uncovering valuable 3-D internal and surface renderings of scientifically important fossils, however poor contrast and X-ray penetration often prevents thorough tomographic analysis. DINGO, Australia’s first and only neutron micro-computed tomography (nCT) instrument, located at the OPAL nuclear research reactor, is being used to obtain unpreceded reconstructions of ex traordinary fossilised anatomical features not visible with conventional imaging techniques. This presentation will outline the physical capabilities of DINGO, the limitations and results to-date in the field of palaeontology. Drawing upon specimens scanned from across Australia, North America, New Zealand, and China, this presentation will demonstrate the complementarity of nCT to classic XCT methods for certain geological formations and fossil localities. nCT has yielded unpreceded contrast and detailed-reconstructions of fossilised soft tissue in a Juras sic cynodont. The stomach contents and digestive function of herbivourous and carnivorous di nosaurs, and a Cretaceous Australian crocodilian have been revealed, providing insights into an cient environments and food chains. In this way, a new species of Australian dinosaur has been discovered. © The Author.
- ItemNew developments in neutron imaging at DINGO(Australian Nuclear Science and Technology Organisation, 2021-11-25) Garbe, U; Bevitt, JJ; Salvemini, FThe neutron radiography / tomography / imaging instrument DINGO is operational since October 2014 to support research at ANSTO. DINGO provides a useful tool to give a different insight into objects. A major part of applications from research and industrial users was demanding high resolution setup and fast scans on DINGO. The neutron beam size can be adjusted to the sample size from 25 x 25 mm 2 to 200 x 200 mm 2 with a resulting pixel size from 12μm to ~100μm. Depending on the sample composition a full tomography has been taken in 10 minute – 36 hours. During the recent OPAL long shutdown, a new sapphire filter has been installed to reduce the amount of epithermal and fast neutrons at the sample position. These high energy neutrons do not contribute to the image, only as noise, and increasing the radiation levels around the CMOS camera. This update will improve the image quality as well as the reliability of the whole instrument. In addition, we implement a new type of neutron tomography scan to address long samples like in drill cores. These samples can now be scanned horizontal up two 1.2 meter in length. For small core sizes we can run up to three cores in one scan, which makes DINGO a very competitive instrument for fast high throughput imaging. A new software package for 3D reconstruction has been developed as well. It is an open source package based on the python toolbox “tomopy” with a GUI custom made for DINGO to enable users to run the reconstruction on their own computing environment. © 2021 The Authors
- ItemA non-destructive investigation of two Cypriot bronze age knife blades using neutron diffraction residual stress analysis(Materials Research Forum LLC, 2016-07-03) Davey, C; Saunders, D; Luzin, V; Bevitt, JJ; Webb, J; Donlon, J; Ionescu, MThis paper presents the results of a residual stress analysis that is part of a wider study of Cypriot Bronze Age knife and other weapon blades from a corpus of artefacts held by a number of institutions in Australia. The current focus is on knives from Early/Middle Bronze Age burial sites at Bellapais Vounous, Cyprus; a significant number of the blades were found on excavation to be bent. The aim of the study was to provide, by means of non-destructive neutron residual stress analysis, likely insights into fabrication methodologies of the knives and determine the stage in the life of each knife blade at which bending occurred. Two Vounous knives from the Australian Institute of Archaeology collection, one measurably bent and the other severely bent and broken, were studied using neutron diffractometer KOWARI to establish the residual stress profiles through the thickness of the knives at several locations. Since the knives were 1 - 2 mm thick at their thinnest sections, a very high through-thickness spatial resolution of 0.1 mm was used to resolve the residual stress profiles. The experimental data from the knives suggested forging/hammering as a possible method of fabrication of functional (hard edge) knife blade. Most significantly, however, the post fabrication bending of both knives at ambient temperature was established. The residual stress data for the two knives were considered in the context of reported metallurgical studies and the archaeological information from Cypriot Bronze Age sites. © The Authors