Understanding fluid flow in shale rocks is critical for the recovery of unconventional energy resources. Despite the extensive research conducted on water and oil flow in shales, significant ...uncertainties and discrepancies remain in reported experimental data. The most noted being that while oil spreads more than water on shale surfaces in an inviscid medium, its uptake by shale pores is much less than water during capillary flow. This leads to misjudgement of wettability and the underlying physical phenomena. In this study, therefore, we performed a combined experimental and digital rock investigation on an organic-rich shale including contact angle and spontaneous imbibition, X-ray and neutron computed tomography, and small angle X-ray scattering tests to study the potential physical processes. We also used non-equilibrium thermodynamics to theoretically derive constitutive equations to support our experimental observations. The results of this study indicate that the pre-existing fractures (first continuum) imbibe more oil than water consistent with contact angle measurements. The overall imbibition is, however, higher for water than oil due to greater water diffusion into the shale matrix (second continuum). It is shown that more water uptake into shale is controlled by pore size and accessibility in addition to capillary or osmotic forces i.e. configurational diffusion of water versus oil molecules. While the inorganic pores seem more oil-wet in an inviscid medium, they easily allow passage of water molecules compared to oil due to the incredibly small size of water molecules that can pass through such micro-pores. Contrarily, these strongly oil-wet pores possessing strong capillarity are restricted to imbibe oil simply due to its large molecular size and physical inaccessibility to the micro-pores. These results provide new insights into the previously unexplained discrepancy regarding water and oil uptake capacity of shales.
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•Re-melting scan strategy reduced residual stresses magnitude by approximately 25%.•Total fill strategy led to strong crystallographic fiber texture 〈001〉 // scan direction.•Defects ...(>50 µm) at the interface between the sections were observed for sectional strategies.
Process parameters in laser-based powder bed fusion (LBPF) play a vital role in the part quality. In the current study, the influence of different novel scan strategies on residual stress, porosities, microstructure, and crystallographic texture has been investigated for complex L-shape parts made from nickel-based superalloy Inconel 718 (IN718). Four different novel scanning strategies representing total fill, re-melting, and two different sectional scanning strategies, were investigated using neutron diffraction, neutron imaging, and scanning electron microscopy techniques. These results were compared with the corresponding results for an L-shape sample printed with the conventional strategy used for achieving high density and more uniform crystallographic texture. Among these investigated novel strategies, the re-melting strategy yielded approximately a 25% reduction in surface residual stress in comparison to the reference sample. The other two sectional scanning strategies revealed porosities at the interfaces of the sections and due to these lower levels of residual stress were also observed. Also, variation in crystallographic texture was observed with different scan strategies.
Ancient Indian iron artefacts have always fascinated researchers due to their excellent corrosion resistance, but the scientific explanation of this feature remains to be elucidated. We have ...investigated corrosion resistance of iron manufactured according to traditional metallurgical processes by the Indian tribes called 'Agaria'. Iron samples were recovered from central India (Aamadandh, Korba district, Chhattisgarh). Iron artefacts are investigated using a range of correlative microscopic, spectroscopic, diffraction and tomographic techniques to postulate the hidden mechanisms of superlative corrosion resistance. The importance of manufacturing steps, ingredients involved in Agaria's iron making process, and post-metal treatment using metal-working operation called hot hammering (forging) is highlighted. This study also hypothesizes the probable protective mechanisms of corrosion resistance of iron. Findings are expected to have a broad impact across multiple disciplines such as archaeology, metallurgy and materials science.
The vortex fluidic device (VFD) is a thin film microfluidic platform which has a wide range of applications in synthesis and other areas of science, and it is important to understand the nature of ...the thin film of liquid in its inclined rapidly rotating tube. Neutron imaging has been used to determine the thickness of the film in a quartz tube with its shape modelled mathematically, showing good agreement between the model and experiments. The resultant equations are useful for studying VFD mediated processing in general, for which the optimal tilt angle of the tube is typically 45°. This includes its utility for the intelligent scale-up of organic syntheses, as demonstrated in the present study by the scaling up of an imine and amide synthesis to >1 g/min.
The paper focuses on a seventeenth century Japanese helmet (
kabuto
) from the Saotome School; previous investigations revealed that its lamellae, made of high-quality low-carbon steel, were ...assembled following a novel structure that suggested higher resistance to firearms. Neutron diffraction represents the ideal technique for the characterisation of the microstructural properties of metals. In this work, neutron diffraction on a highly collimated instrument, such as ENGIN-X (ISIS, UK), was used to quantify the distribution of residual strains along lamellae arranged in this newly discovered assembly method, and therefore infer on the mechanical properties of the Saotome
kabuto
. Here, we present novel results investigating residual stresses from diffraction measurements by using the instrument ENGIN-X. This study completes the previous cycle of neutron measurements on this sample and sheds light on the effectiveness of the assembly method of the plates.
Since commencing operation in 2014, the Dingo neutron imaging facility has expanded capabilities of investigating materials of cultural heritage significance at the Australian Nuclear Science and ...Technology Organisation. This paper offers an overview of the diverse range of artefacts investigated on the beamline during the last decade. A selection of case studies established through national and international collaborations showcases how neutron imaging can provide university and museum users with a powerful analytical tool for non-invasive real-space evaluation of a variety of ancient artefacts with properties complementary to other nuclear methods.
Graphical abstract
A bronze wine vessel attributed to 1600–1046 B.C., Shang dynasty in China, an object from the East Asian Collection of the Museum of Applied Arts and Sciences in Sydney (Australia), was studied using ...a non-destructive scientific analytical protocol based on the synergic combination of nuclear techniques. Gamma spectrometry, neutron-computed tomography, and proton-induced X-ray emission (PIXE) spectroscopy were applied to gain a better insight into the structural and compositional features of the artefact to prove its authenticity. Gamma spectrometry was performed to assess the risk of excessive sample activation induced by long exposure to the neutron beam and to determine the bulk elemental composition. Based on neutron-computed tomography, the porosities and the thickness of the metal wall were evaluated and found consistent with the piece-mould casting technology adopted by craftsmen during the Shang dynasty in China. Finally, PIXE spectroscopy demonstrated the use of a ternary (copper–tin-leaded) alloy and the nature of mineralisation on the surface.
This study focuses on a non-invasive characterization of a set of ancient
kris
by means of neutron imaging and diffraction methods. The
kris
(or
keris
) is an elongated dagger or short sword ...distinctive of Malaysia and Indonesia. Its complex structure results from the combination of several layers of iron, steel and sometimes iron–nickel alloy welded together in an intricate pattern that is brought out on the polished surface of the blade through the use of an etchant. Based on the tomographic analysis, four different structural arrangements were identified for the first time. Complementarily, the average quality of the ferrous materials used to produce the four
kris
was evaluated via time-of-flight neutron diffraction analysis. New details about the manufacturing process of a still little studied class of artefacts were derived from our investigation.
Japanese blades are culturally interesting objects both from the stylistic point of view and because of their fantastic performance. In this work, we present new results, using a non-invasive ...approach, concerning these peculiar artefacts. Five Japanese swords pertaining to Koto (987-1596) and Shinto (1596-1781) periods have been analysed through white beam and energy resolved neutron-imaging techniques. The experiments have been performed at the ICON beam line, operating at the spallation neutron source SINQ, Paul Scherrer Institut in Switzerland. The reconstruction of projection data into neutron tomographic slices or volumes allowed us to identify some peculiar characteristics, related to the forging methods that were used by the different schools and traditions in Japan.
In this communication, we demonstrate the use of neutron tomography for the structural characterization of iron meteorites. These materials prevalently consist of metallic iron with variable nickel ...content. Their study and classification is traditionally based on chemical and structural analysis. The latter requires cutting, polishing and chemical etching of large slabs of the sample in order to determine the average width of the largest kamacite lamellae. Although this approach is useful to infer the genetical history of these meteorites, it is not applicable to small or precious samples. On the base of different attenuation coefficient of cold neutrons for nickel and iron, neutron tomography allows the reconstruction of the Ni-rich (taenite) and Ni-poor (kamacite) metallic phases. Therefore, the measure of the average width of the largest kamacite lamellae could be determined in a non-destructive way. Furthermore, the size, shape, and spatial correlation between kamacite and taenite crystals were obtained more efficiently and accurately than via metallographic investigation.
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