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Blaž Likozar - One of the best experts on this subject based on the ideXlab platform.

  • Application of Mössbauer spectroscopy in industrial heterogeneous catalysis: effect of oxidant on FePO4 Material Phase transformations in direct methanol synthesis from methane
    Hyperfine Interactions, 2017
    Co-Authors: Venkata D. B. C. Dasireddy, Faiza B. Khan, Darko Hanžel, Krish Bharuth-ram, Blaž Likozar
    Abstract:

    The effect of the FePO4 Material Phase transformation in the direct selective oxidation of methane to methanol was studied using various oxidants, i.e. O2, H2O and N2O. The Phases of the heterogeneous catalyst applied, before and after the reactions, were characterized by M¨ossbauer spectroscopy. The main reaction products were methanol, carbon monoxide and carbon dioxide, whereas formaldehyde was produced in rather minute amounts. The Mossbauer spectra showed the change of the initial catalyst Material, FePO4 (tridymite-like Phase (tdm)), to the reduced metal form, iron(II) pyrophosphate, Fe2P2O7, and thereafter, the Material Phase change was governed by the oxidation with individual oxidizing species.Mossbauer spectroscopy measurements applied along with X-ray diffraction (XRD) studies on fresh, reduced and spent catalytic Materials demonstrated a transformation of the catalyst to a mixture of Phases which depended on operating process conditions. Generally, activity was low and should be a subject of further Material optimization and engineering, while the selectivity towards methanol at low temperatures applied was adequate. The proceeding redox mechanism should thus play a key role in catalytic Material design, while the advantage of iron-based heterogeneous catalysts primarily lies in them being comparably inexpensive and comprising non-critical raw Materials only.

  • Application of Mössbauer spectroscopy in industrial heterogeneous catalysis: effect of oxidant on FePO4Material Phase transformations in direct methanol synthesis from methane
    Hyperfine Interactions, 2017
    Co-Authors: Venkata D. B. C. Dasireddy, Faiza B. Khan, Krish Bharuth-ram, Darko Hanžel, Blaž Likozar
    Abstract:

    © 2017, Springer International Publishing Switzerland. The effect of the FePO 4 Material Phase transformation in the direct selective oxidation of methane to methanol was studied using various oxidants, i.e. O 2 , H 2 O and N 2 O. The Phases of the heterogeneous catalyst applied, before and after the reactions, were characterized by M¨ossbauer spectroscopy. The main reaction products were methanol, carbon monoxide and carbon dioxide, whereas formaldehyde was produced in rather minute amounts. The Mössbauer spectra showed the change of the initial catalyst Material, FePO 4 (tridymite-like Phase (tdm)), to the reduced metal form, iron(II) pyrophosphate, Fe 2 P 2 O 7 , and thereafter, the Material Phase change was governed by the oxidation with individual oxidizing species.Mössbauer spectroscopy measurements applied along with X-ray diffraction (XRD) studies on fresh, reduced and spent catalytic Materials demonstrated a transformation of the catalyst to a mixture of Phases which depended on operating process conditions. Generally, activity was low and should be a subject of further Material optimization and engineering, while the selectivity towards methanol at low temperatures applied was adequate. The proceeding redox mechanism should thus play a key role in catalytic Material design, while the advantage of iron-based heterogeneous catalysts primarily lies in them being comparably inexpensive and comprising non-critical raw Materials only.

I. G. Koprinkov - One of the best experts on this subject based on the ideXlab platform.

James K. Guest - One of the best experts on this subject based on the ideXlab platform.

  • Projection-based two-Phase minimum and maximum length scale control in topology optimization
    Structural and Multidisciplinary Optimization, 2018
    Co-Authors: Josephine V. Carstensen, James K. Guest
    Abstract:

    Length scale control in topology optimization is an important area of research with direct implications on numerical stability and solution manufacturability. Projection-based algorithms for continuum topology optimization have received considerable attention in recent years due to their ability to control minimum length scale in a flexible and computationally efficient manner. In this paper, we propose a new projection-based algorithm that embeds minimum length scale control on two Material Phases (e.g., solid and void) as well as optional maximum length scale on one Material Phase (e.g., solid or void) into the projection methodology used for Material distribution approaches to topology optimization. The proposed algorithms are demonstrated on benchmark problems and are shown to satisfy the length scale constraints imposed.

Venkata D. B. C. Dasireddy - One of the best experts on this subject based on the ideXlab platform.

  • Application of Mössbauer spectroscopy in industrial heterogeneous catalysis: effect of oxidant on FePO4 Material Phase transformations in direct methanol synthesis from methane
    Hyperfine Interactions, 2017
    Co-Authors: Venkata D. B. C. Dasireddy, Faiza B. Khan, Darko Hanžel, Krish Bharuth-ram, Blaž Likozar
    Abstract:

    The effect of the FePO4 Material Phase transformation in the direct selective oxidation of methane to methanol was studied using various oxidants, i.e. O2, H2O and N2O. The Phases of the heterogeneous catalyst applied, before and after the reactions, were characterized by M¨ossbauer spectroscopy. The main reaction products were methanol, carbon monoxide and carbon dioxide, whereas formaldehyde was produced in rather minute amounts. The Mossbauer spectra showed the change of the initial catalyst Material, FePO4 (tridymite-like Phase (tdm)), to the reduced metal form, iron(II) pyrophosphate, Fe2P2O7, and thereafter, the Material Phase change was governed by the oxidation with individual oxidizing species.Mossbauer spectroscopy measurements applied along with X-ray diffraction (XRD) studies on fresh, reduced and spent catalytic Materials demonstrated a transformation of the catalyst to a mixture of Phases which depended on operating process conditions. Generally, activity was low and should be a subject of further Material optimization and engineering, while the selectivity towards methanol at low temperatures applied was adequate. The proceeding redox mechanism should thus play a key role in catalytic Material design, while the advantage of iron-based heterogeneous catalysts primarily lies in them being comparably inexpensive and comprising non-critical raw Materials only.

  • Application of Mössbauer spectroscopy in industrial heterogeneous catalysis: effect of oxidant on FePO4Material Phase transformations in direct methanol synthesis from methane
    Hyperfine Interactions, 2017
    Co-Authors: Venkata D. B. C. Dasireddy, Faiza B. Khan, Krish Bharuth-ram, Darko Hanžel, Blaž Likozar
    Abstract:

    © 2017, Springer International Publishing Switzerland. The effect of the FePO 4 Material Phase transformation in the direct selective oxidation of methane to methanol was studied using various oxidants, i.e. O 2 , H 2 O and N 2 O. The Phases of the heterogeneous catalyst applied, before and after the reactions, were characterized by M¨ossbauer spectroscopy. The main reaction products were methanol, carbon monoxide and carbon dioxide, whereas formaldehyde was produced in rather minute amounts. The Mössbauer spectra showed the change of the initial catalyst Material, FePO 4 (tridymite-like Phase (tdm)), to the reduced metal form, iron(II) pyrophosphate, Fe 2 P 2 O 7 , and thereafter, the Material Phase change was governed by the oxidation with individual oxidizing species.Mössbauer spectroscopy measurements applied along with X-ray diffraction (XRD) studies on fresh, reduced and spent catalytic Materials demonstrated a transformation of the catalyst to a mixture of Phases which depended on operating process conditions. Generally, activity was low and should be a subject of further Material optimization and engineering, while the selectivity towards methanol at low temperatures applied was adequate. The proceeding redox mechanism should thus play a key role in catalytic Material design, while the advantage of iron-based heterogeneous catalysts primarily lies in them being comparably inexpensive and comprising non-critical raw Materials only.

Thomas M. Dillon - One of the best experts on this subject based on the ideXlab platform.

  • Bioassessment Methodologies for the Regulatory Testing of Freshwater Dredged Material. Phase 2
    1990
    Co-Authors: Greg Busacker, Dennis Anderson, Alfreda B. Gibson, Thomas M. Dillon
    Abstract:

    Abstract : This report represents the second Phase of a 3-year (three-Phase) project that the Wisconsin Department of Natural Resources (WDNR) requested from the St. Paul District as planning assistance under Section 22 of the Water Resources Development Act of 1974 (Public Law 93-251). The State of Wisconsin is interested in identifying appropriate bioassessment testing methodologies for the regulatory testing of freshwater sediments scheduled for dredging and open- water disposal. The report includes discussions and recommendations for specific approaches to bioassessment methods in the tiered testing protocol. The methods described in this report have the potential to be the most frequently used testing techniques, and represent the backbone of the tiered testing evaluation for regulatory testing of freshwater sediments. Keywords: Acute lethality test; Bioassessment techniques; Chronic life cycle test; Dredged Material; Dredging environmental aspects; Water quality bioassay; Methodology; Water quality management.

  • Bioassessment methodologies for the regulatory testing of freshwater dredged Material. Phase 2. Final report
    1990
    Co-Authors: Greg Busacker, Dennis Anderson, Alfreda B. Gibson, Thomas M. Dillon
    Abstract:

    This report represents the second Phase of a 3-year (three-Phase) project that the Wisconsin Department of Natural Resources (WDNR) requested from the St. Paul District as planning assistance under Section 22 of the Water Resources Development Act of 1974 (Public Law 93-251). The State of Wisconsin is interested in identifying appropriate bioassessment testing methodologies for the regulatory testing of freshwater sediments scheduled for dredging and open-water disposal. The report includes discussions and recommendations for specific approaches to bioassessment methods in the tiered testing protocol. The methods described in this report have the potential to be the most frequently used testing techniques, and represent the backbone of the tiered testing evaluation for regulatory testing of freshwater sediments.