LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 7 of total 7

Search options

  1. Article ; Online: The Imaging Resolution and Knudsen Effect on the Mass Transport of Shale Gas Assisted by Multi-length Scale X-Ray Computed Tomography

    Francesco Iacoviello / Xuekun Lu / Thomas M. Mitchell / Daniel J. L. Brett / Paul R. Shearing

    Scientific Reports, Vol 9, Iss 1, Pp 1-

    2019  Volume 10

    Abstract: Abstract The spatial resolution of 3D imaging techniques is often balanced by the achievable field of view. Since pore size in shales spans more than two orders of magnitude, a compromise between representativeness and accuracy of the 3D reconstructed ... ...

    Abstract Abstract The spatial resolution of 3D imaging techniques is often balanced by the achievable field of view. Since pore size in shales spans more than two orders of magnitude, a compromise between representativeness and accuracy of the 3D reconstructed shale microstructure is needed. In this study, we characterise the effect of imaging resolution on the microstructural and mass transport characteristics of shales using micro and nano-computed tomography. 3D mass transport simulation using continuum and numerical physics respectively is also compared to highlight the significance of the Knudsen effect on the reconstructed solid surface. The result shows that porosity measured by micro-CT is 25% lower than nano-CT, resulting in an overestimated pore size distribution and underestimated pore connectivity. This leads to a higher simulated intrinsic permeability. An overestimated diffusive flux and underestimated permeability are obtained from the continuum mass transport simulation compared to the numerical ones when the molecular-wall collision is accounted, evidenced by the large deviation of the measured Knudsen tortuosity factor and permeability correction factor. This study is believed to provide new knowledge in understanding the importance of imaging resolution and gas flow physics on mass transport in porous media.
    Keywords Medicine ; R ; Science ; Q
    Subject code 621
    Language English
    Publishing date 2019-12-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article ; Online: Tracking the evolution of a single composite particle during redox cycling for application in H2 production

    Dragos Neagu / Evangelos I. Papaioannou / Bernhard Tjaden / Xuekun Lu / Cheuk-Man Mak / Michael W. Gaultois / Brian Ray / Paul Shearing / Ian S. Metcalfe

    Scientific Reports, Vol 10, Iss 1, Pp 1-

    2020  Volume 9

    Abstract: Abstract Composite materials consisting of metal and metal oxide phases are being researched intensively for various energy conversion applications where they are often expected to operate under redox conditions at elevated temperature. Understanding of ... ...

    Abstract Abstract Composite materials consisting of metal and metal oxide phases are being researched intensively for various energy conversion applications where they are often expected to operate under redox conditions at elevated temperature. Understanding of the dynamics of composite evolution during redox cycling is still very limited, yet critical to maximising performance and increasing durability. Here we track the microstructural evolution of a single composite particle over 200 redox cycles for hydrogen production by chemical looping, using multi-length scale X-ray computed tomography. We show that redox cycling triggers a centrifugal redispersion of the metal phase and a centripetal clustering of porosity, both seemingly driven by the asymmetric nature of oxygen exchange in composites. Initially, the particle develops a large amount of internal porosity which boosts activity, but on the long term this facilitates structural and compositional reorganisation and eventually degradation. These results provide valuable insight into redox-driven microstructural changes and also for the design of new composite materials with enhanced durability.
    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2020-03-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article: X-ray tomography-assisted study of a phase inversion process in ceramic hollow fiber systems – Towards practical structural design

    Li, Tao / Bo Wang / Dan J.L. Brett / Kang Li / Paul R. Shearing / Xuekun Lu / Zhentao Wu

    Journal of membrane science. 2017 Apr. 15, v. 528

    2017  

    Abstract: Phase inversion-assisted extrusion processes provide a feasible approach for the development of micro-structured ceramic hollow fibers. The mass transport of the hollow fiber, which is closely correlated to the pore structure, is especially important in ... ...

    Abstract Phase inversion-assisted extrusion processes provide a feasible approach for the development of micro-structured ceramic hollow fibers. The mass transport of the hollow fiber, which is closely correlated to the pore structure, is especially important in the application of fuel cell electrodes and membrane reactors. Whilst the relationship between the pore microstructure and the fabrication factors has been the subject of significant investigations, there remains much disagreement in the literature. Recent development in X-ray computed tomography (CT) has enabled new insight into 3D microstructures, which could help to realize practical morphology design and optimization. In this study, a series of alumina hollow fibers have been prepared with varied polymer binder (polyethersulfone, PESf) concentration and new polymer-based internal coagulant (aqueous solution of polyvinyl alcohol, PVA). For the first time, the micro-channels were characterized in 3D using X-ray CT to determine micro-channel densities and diameters in the radial direction, as well as the 2D measurement of the pore size in the sponge-like layer. Water permeation tests were then conducted to correlate the micro-structure of the hollow fiber to the permeability. Results show that the diameter of the micro-channels decreases as the concentration of polymer binder increases, but the pore size in the spongy-like layer becomes larger. When the polymer binder concentration is increased from 16wt% to 30wt%, the maximum micro-channel diameter is almost halved (from 29 to 15μm), and the radial length is 60% longer, whereas the mean flow pore size in the sponge-like layer is increased from approximately 288 to 422nm. Larger pore size in the spongy-like layer of the high PVA concentration sample contributes to a better permeability (pure water flux almost doubled), but the dimension of the micro-channels is less important. This study provides a new approach to optimize fabrication of hollow fibers for various applications.
    Keywords aluminum oxide ; aqueous solutions ; artificial membranes ; ceramics ; computed tomography ; electrodes ; extrusion ; fuel cells ; mass transfer ; microstructure ; permeability ; polyvinyl alcohol ; porosity ; X-radiation
    Language English
    Dates of publication 2017-0415
    Size p. 24-33.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 194516-6
    ISSN 0376-7388
    ISSN 0376-7388
    DOI 10.1016/j.memsci.2017.01.004
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 78/706: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Article ; Online: 3D microstructure design of lithium-ion battery electrodes assisted by X-ray nano-computed tomography and modelling

    Xuekun Lu / Antonio Bertei / Donal P. Finegan / Chun Tan / Sohrab R. Daemi / Julia S. Weaving / Kieran B. O’Regan / Thomas M. M. Heenan / Gareth Hinds / Emma Kendrick / Dan J. L. Brett / Paul R. Shearing

    Nature Communications, Vol 11, Iss 1, Pp 1-

    2020  Volume 13

    Abstract: The 3D microstructure of the electrode predominantly determines the electrochemical performance of Li-ion batteries. Here, the authors show that the microstructural heterogeneities lead to non-uniform Li insertion and current distribution while graded- ... ...

    Abstract The 3D microstructure of the electrode predominantly determines the electrochemical performance of Li-ion batteries. Here, the authors show that the microstructural heterogeneities lead to non-uniform Li insertion and current distribution while graded-microstructures improve the performance.
    Keywords Science ; Q
    Language English
    Publishing date 2020-04-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: 3D microstructure design of lithium-ion battery electrodes assisted by X-ray nano-computed tomography and modelling

    Xuekun Lu / Antonio Bertei / Donal P. Finegan / Chun Tan / Sohrab R. Daemi / Julia S. Weaving / Kieran B. O’Regan / Thomas M. M. Heenan / Gareth Hinds / Emma Kendrick / Dan J. L. Brett / Paul R. Shearing

    Nature Communications, Vol 11, Iss 1, Pp 1-

    2020  Volume 13

    Abstract: The 3D microstructure of the electrode predominantly determines the electrochemical performance of Li-ion batteries. Here, the authors show that the microstructural heterogeneities lead to non-uniform Li insertion and current distribution while graded- ... ...

    Abstract The 3D microstructure of the electrode predominantly determines the electrochemical performance of Li-ion batteries. Here, the authors show that the microstructural heterogeneities lead to non-uniform Li insertion and current distribution while graded-microstructures improve the performance.
    Keywords Science ; Q
    Language English
    Publishing date 2020-04-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article ; Online: Design of next-generation ceramic fuel cells and real-time characterization with synchrotron X-ray diffraction computed tomography

    Tao Li / Thomas M. M. Heenan / Mohamad F. Rabuni / Bo Wang / Nicholas M. Farandos / Geoff H. Kelsall / Dorota Matras / Chun Tan / Xuekun Lu / Simon D. M. Jacques / Dan J. L. Brett / Paul R. Shearing / Marco Di Michiel / Andrew M. Beale / Antonis Vamvakeros / Kang Li

    Nature Communications, Vol 10, Iss 1, Pp 1-

    2019  Volume 11

    Abstract: Miniaturized ceramic fuel cells are attractive for portable devices, but performance should be optimized. Here the authors report a micro-monolithic ceramic cell design for a tubular solid oxide fuel cell containing a multi-channel anode support with ... ...

    Abstract Miniaturized ceramic fuel cells are attractive for portable devices, but performance should be optimized. Here the authors report a micro-monolithic ceramic cell design for a tubular solid oxide fuel cell containing a multi-channel anode support with enhanced power density and stable operation.
    Keywords Science ; Q
    Language English
    Publishing date 2019-04-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article ; Online: Design of next-generation ceramic fuel cells and real-time characterization with synchrotron X-ray diffraction computed tomography

    Tao Li / Thomas M. M. Heenan / Mohamad F. Rabuni / Bo Wang / Nicholas M. Farandos / Geoff H. Kelsall / Dorota Matras / Chun Tan / Xuekun Lu / Simon D. M. Jacques / Dan J. L. Brett / Paul R. Shearing / Marco Di Michiel / Andrew M. Beale / Antonis Vamvakeros / Kang Li

    Nature Communications, Vol 10, Iss 1, Pp 1-

    2019  Volume 11

    Abstract: Miniaturized ceramic fuel cells are attractive for portable devices, but performance should be optimized. Here the authors report a micro-monolithic ceramic cell design for a tubular solid oxide fuel cell containing a multi-channel anode support with ... ...

    Abstract Miniaturized ceramic fuel cells are attractive for portable devices, but performance should be optimized. Here the authors report a micro-monolithic ceramic cell design for a tubular solid oxide fuel cell containing a multi-channel anode support with enhanced power density and stable operation.
    Keywords Science ; Q
    Language English
    Publishing date 2019-04-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top