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Hill, Anita J. - One of the best experts on this subject based on the ideXlab platform.

  • Flux melting of metal-organic frameworks
    'Royal Society of Chemistry (RSC)', 2019
    Co-Authors: Longley Louis, Collins, Sean M., Li Shichun, Smales, Glen J., Erucar Ilknur, Qiao Ang, Hou Jingwei, Doherty, Cara M., Thornton, Aaron W., Hill, Anita J.
    Abstract:

    Recent demonstrations of melting in the metal-organic framework (MOF) family have created interest in the interfacial domain between inorganic glasses and amorphous organic polymers. The chemical and physical behaviour of porous hybrid liquids and glasses is of particular interest, though opportunities are limited by the inaccessible melting temperatures of many MOFs. Here, we show that the processing technique of Flux melting, 'borrowed' from the inorganic domain, may be applied in order to melt ZIF-8, a material which does not possess an accessible liquid state in the pure form. Effectively, we employ the high-temperature liquid state of one MOF as a solvent for a secondary, non-melting MOF component. Differential scanning calorimetry, small- and wide-angle X-ray scattering, electron microscopy and X-ray total scattering techniques are used to show the Flux melting of the crystalline component within the liquid. Gas adsorption and positron annihilation lifetime spectroscopy measurements show that this results in enhanced, accessible porosity to a range of guest molecules in the Resultant Flux melted MOF glass

Aj Hill - One of the best experts on this subject based on the ideXlab platform.

  • Flux melting of metal–organic frameworks
    'Royal Society of Chemistry (RSC)', 2019
    Co-Authors: Longley L, Sm Collins, Li S, Gj Smales, Qiao A, Hou J, Doherty Cm, Aw Thornton, Aj Hill
    Abstract:

    Recent demonstrations of melting in the metal–organic framework (MOF) family have created interest in the interfacial domain between inorganic glasses and amorphous organic polymers. The chemical and physical behaviour of porous hybrid liquids and glasses is of particular interest, though opportunities are limited by the inaccessible melting temperatures of many MOFs. Here, we show that the processing technique of Flux melting, ‘borrowed’ from the inorganic domain, may be applied in order to melt ZIF-8, a material which does not possess an accessible liquid state in the pure form. Effectively, we employ the high-temperature liquid state of one MOF as a solvent for a secondary, non-melting MOF component. Differential scanning calorimetry, small- and wide-angle X-ray scattering, electron microscopy and X-ray total scattering techniques are used to show the Flux melting of the crystalline component within the liquid. Gas adsorption and positron annihilation lifetime spectroscopy measurements show that this results in enhanced, accessible porosity to a range of guest molecules in the Resultant Flux melted MOF glass

Chongam Kim - One of the best experts on this subject based on the ideXlab platform.

  • accurate efficient and monotonic numerical methods for multi dimensional compressible flows part i spatial discretization
    Journal of Computational Physics, 2005
    Co-Authors: Kyu Hong Kim, Chongam Kim
    Abstract:

    Abstract The present papers deal with numerical methods toward the accurate and efficient computations of multi-dimensional steady/unsteady compressible flows. In Part I, a new spatial discretization technique is introduced to reduce excessive numerical dissipation in a non-flow-aligned grid system. Through the analysis of TVD limiters, a criterion is proposed to predict cell-interface states accurately both in smooth region and in discontinuous region. According to the criterion, a new way of re-evaluating the cell-interface convective Flux in AUSM-type methods is developed. The Resultant Flux reduces numerical dissipation remarkably in multi-dimensional flows. Also, the monotonicity of AUSM-type methods is achieved by modifying the pressure splitting function directly based on the governing equations and the detection of sonic transition point with respect to a cell-interface. It is noted that the newly formulated AUSM-type Flux for Multi-dimensional flows, named M-AUSMPW+, possesses many improved properties in term of accuracy, computational efficiency, monotonicity and grid independency. Through numerous test cases from contact and shock discontinuities, vortex flow, shock wave/boundary-layer interaction to viscous shock tube problems, M-AUSMPW+ proves to be efficient and about twice more accurate than conventional upwind schemes. The three-dimensional implementation of M-AUSMPW+ is expected to provide accuracy and efficiency improvement furthermore.

Marianne Balatpichelin - One of the best experts on this subject based on the ideXlab platform.

  • high temperature oxidation of stainless steel aisi316l in air plasma
    Applied Surface Science, 2008
    Co-Authors: Alenka Vesel, Miran Mozetic, Aleksander Drenik, Nina Hauptman, Marianne Balatpichelin
    Abstract:

    Abstract A study on surface oxidation of AISI316L stainless steel surface was performed. Stainless steel was oxidized in air plasma with a high degree of dissociation of oxygen molecules of about 70%. The Resultant Flux of oxygen atoms to the surface was about 1 × 10 24  m −2  s −1 . The oxidation was performed at high temperatures ranging up to 1250 K. The oxidation time was 5 min. After oxidation the surface of the samples was analyzed by different methods including Auger electron depth profiling (AES), X-ray photoelectron spectroscopy (XPS), scanning electron spectroscopy (SEM) and X-ray diffraction (XRD). The microstructure and composition of the surface were temperature dependent. In all cases high Cr concentration was observed on the surface after oxidation at a temperature above 600 K. With increasing temperature Mn concentration at the surface increased as well. Below 1000 K the oxide film was uniform, while above 1000 K islands with large spinel particles were observed to appear.

Longley L - One of the best experts on this subject based on the ideXlab platform.

  • Flux melting of metal–organic frameworks
    'Royal Society of Chemistry (RSC)', 2019
    Co-Authors: Longley L, Sm Collins, Li S, Gj Smales, Qiao A, Hou J, Doherty Cm, Aw Thornton, Aj Hill
    Abstract:

    Recent demonstrations of melting in the metal–organic framework (MOF) family have created interest in the interfacial domain between inorganic glasses and amorphous organic polymers. The chemical and physical behaviour of porous hybrid liquids and glasses is of particular interest, though opportunities are limited by the inaccessible melting temperatures of many MOFs. Here, we show that the processing technique of Flux melting, ‘borrowed’ from the inorganic domain, may be applied in order to melt ZIF-8, a material which does not possess an accessible liquid state in the pure form. Effectively, we employ the high-temperature liquid state of one MOF as a solvent for a secondary, non-melting MOF component. Differential scanning calorimetry, small- and wide-angle X-ray scattering, electron microscopy and X-ray total scattering techniques are used to show the Flux melting of the crystalline component within the liquid. Gas adsorption and positron annihilation lifetime spectroscopy measurements show that this results in enhanced, accessible porosity to a range of guest molecules in the Resultant Flux melted MOF glass