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1. From little things big things grow: enhancement of an acoustic telemetry network to monitor broad-scale movements of marine species along Australia’s east coast

Author

Barnett, Adam, Jaine, Fabrice R. A., Bierwagen, Stacy L., Lubitz, Nicolas, Abrantes, Kátya, Heupel, Michelle R., Harcourt, Rob, Huveneers, Charlie, Dwyer, Ross G., Udyawer, Vinay, Simpfendorfer, Colin A., Miller, Ingo B., Scott-Holland, Tracey, Kilpatrick, Carley S., Williams, Samuel M, Smith, Daniel, Dudgeon, Christine L., Hoey, Andrew S., Fitzpatrick, Richard, Osborne, Felicity E., Smoothey, Amy F., Butcher, Paul A., Sheaves, Marcus, Fisher, Eric E., Svaikauskas, Mark, Ellis, Megan, Kanno, Shiori, Cresswell, Benjamin J., Flint, Nicole, Armstrong, Asia O., Townsend, Kathy A., Mitchell, Jonathan D., Campbell, Matthew, Peddemors, Victor M., Gustafson, Johan A., and Currey-Randall, Leanne M.

Published
2024
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5. Reply to: Shark mortality cannot be assessed by fishery overlap alone

Author

Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, da Costa, Ivo, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, Acuña-Marrero, David, Afonso, André S., Afonso, Pedro, Anders, Darrell, Araujo, Gonzalo, Arauz, Randall, Bach, Pascal, Barnett, Adam, Bernal, Diego, Berumen, Michael L., Lion, Sandra Bessudo, Bezerra, Natalia P. A., Blaison, Antonin V., Block, Barbara A., Bond, Mark E., Bonfil, Ramon, Bradford, Russell W., Braun, Camrin D., Brooks, Edward J., Brooks, Annabelle, Brown, Judith, Bruce, Barry D., Byrne, Michael E., Campana, Steven E., Carlisle, Aaron B., Chapman, Demian D., Chapple, Taylor K., Chisholm, John, Clarke, Christopher R., Clua, Eric G., Cochran, Jesse E. M., Crochelet, Estelle C., Dagorn, Laurent, Daly, Ryan, Cortés, Daniel Devia, Doyle, Thomas K., Drew, Michael, Duffy, Clinton A. J., Erikson, Thor, Espinoza, Eduardo, Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Fischer, G. Chris, Fitzpatrick, Richard, Fontes, Jorge, Forget, Fabien, Fowler, Mark, Francis, Malcolm P., Gallagher, Austin J., Gennari, Enrico, Goldsworthy, Simon D., Gollock, Matthew J., Green, Jonathan R., Gustafson, Johan A., Guttridge, Tristan L., Guzman, Hector M., Hammerschlag, Neil, Harman, Luke, Hazin, Fábio H. V., Heard, Matthew, Hearn, Alex R., Holdsworth, John C., Holmes, Bonnie J., Howey, Lucy A., Hoyos, Mauricio, Hueter, Robert E., Hussey, Nigel E., Huveneers, Charlie, Irion, Dylan T., Jacoby, David M. P., Jewell, Oliver J. D., Johnson, Ryan, Jordan, Lance K. B., Joyce, Warren, Keating Daly, Clare A., Ketchum, James T., Klimley, A. Peter, Kock, Alison A., Koen, Pieter, Ladino, Felipe, Lana, Fernanda O., Lea, James S. E., Llewellyn, Fiona, Lyon, Warrick S., MacDonnell, Anna, Macena, Bruno C. L., Marshall, Heather, McAllister, Jaime D., Meÿer, Michael A., Morris, John J., Nelson, Emily R., Papastamatiou, Yannis P., Peñaherrera-Palma, Cesar, Pierce, Simon J., Poisson, Francois, Quintero, Lina Maria, Richardson, Andrew J., Rogers, Paul J., Rohner, Christoph A., Rowat, David R. L., Samoilys, Melita, Semmens, Jayson M., Sheaves, Marcus, Shillinger, George, Shivji, Mahmood, Singh, Sarika, Skomal, Gregory B., Smale, Malcolm J., Snyders, Laurenne B., Soler, German, Soria, Marc, Stehfest, Kilian M., Thorrold, Simon R., Tolotti, Mariana T., Towner, Alison, Travassos, Paulo, Tyminski, John P., Vandeperre, Frederic, Vaudo, Jeremy J., Watanabe, Yuuki Y., Weber, Sam B., Wetherbee, Bradley M., White, Timothy D., Williams, Sean, Zárate, Patricia M., Harcourt, Robert, Hays, Graeme C., Meekan, Mark G., Thums, Michele, Irigoien, Xabier, Eguiluz, Victor M., Duarte, Carlos M., Sousa, Lara L., Simpson, Samantha J., Southall, Emily J., and Sims, David W.

Published
2021
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6. Reply to: Caution over the use of ecological big data for conservation

Author

Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, da Costa, Ivo, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, Acuña-Marrero, David, Afonso, André S., Afonso, Pedro, Anders, Darrell, Araujo, Gonzalo, Arauz, Randall, Bach, Pascal, Barnett, Adam, Bernal, Diego, Berumen, Michael L., Lion, Sandra Bessudo, Bezerra, Natalia P. A., Blaison, Antonin V., Block, Barbara A., Bond, Mark E., Bonfil, Ramon, Braun, Camrin D., Brooks, Edward J., Brooks, Annabelle, Brown, Judith, Byrne, Michael E., Campana, Steven E., Carlisle, Aaron B., Chapman, Demian D., Chapple, Taylor K., Chisholm, John, Clarke, Christopher R., Clua, Eric G., Cochran, Jesse E. M., Crochelet, Estelle C., Dagorn, Laurent, Daly, Ryan, Cortés, Daniel Devia, Doyle, Thomas K., Drew, Michael, Duffy, Clinton A. J., Erikson, Thor, Espinoza, Eduardo, Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Fischer, G. Chris, Fitzpatrick, Richard, Fontes, Jorge, Forget, Fabien, Fowler, Mark, Francis, Malcolm P., Gallagher, Austin J., Gennari, Enrico, Goldsworthy, Simon D., Gollock, Matthew J., Green, Jonathan R., Gustafson, Johan A., Guttridge, Tristan L., Guzman, Hector M., Hammerschlag, Neil, Harman, Luke, Hazin, Fábio H. V., Heard, Matthew, Hearn, Alex R., Holdsworth, John C., Holmes, Bonnie J., Howey, Lucy A., Hoyos, Mauricio, Hueter, Robert E., Hussey, Nigel E., Huveneers, Charlie, Irion, Dylan T., Jacoby, David M. P., Jewell, Oliver J. D., Johnson, Ryan, Jordan, Lance K. B., Joyce, Warren, Keating Daly, Clare A., Ketchum, James T., Klimley, A. Peter, Kock, Alison A., Koen, Pieter, Ladino, Felipe, Lana, Fernanda O., Lea, James S. E., Llewellyn, Fiona, Lyon, Warrick S., MacDonnell, Anna, Macena, Bruno C. L., Marshall, Heather, McAllister, Jaime D., Meÿer, Michael A., Morris, John J., Nelson, Emily R., Papastamatiou, Yannis P., Peñaherrera-Palma, Cesar, Pierce, Simon J., Poisson, Francois, Quintero, Lina Maria, Richardson, Andrew J., Rogers, Paul J., Rohner, Christoph A., Rowat, David R. L., Samoilys, Melita, Semmens, Jayson M., Sheaves, Marcus, Shillinger, George, Shivji, Mahmood, Singh, Sarika, Skomal, Gregory B., Smale, Malcolm J., Snyders, Laurenne B., Soler, German, Soria, Marc, Stehfest, Kilian M., Thorrold, Simon R., Tolotti, Mariana T., Towner, Alison, Travassos, Paulo, Tyminski, John P., Vandeperre, Frederic, Vaudo, Jeremy J., Watanabe, Yuuki Y., Weber, Sam B., Wetherbee, Bradley M., White, Timothy D., Williams, Sean, Zárate, Patricia M., Harcourt, Robert, Hays, Graeme C., Meekan, Mark G., Thums, Michele, Irigoien, Xabier, Eguiluz, Victor M., Duarte, Carlos M., Sousa, Lara L., Simpson, Samantha J., Southall, Emily J., and Sims, David W.

Published
2021
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7. Dead on the Beach? Predicting the Drift of Whale Remains Improves Management for Offshore Disposal.

Author

Meynecke, Jan-Olaf, Zigic, Sasha, Perez, Larissa, Dunn, Ryan J. K., Benfer, Nathan, Gustafson, Johan, and Bosshard, Simone

Subjects
SUSTAINABILITY, WHALE shark, WHALES, INFECTIOUS disease transmission, DECISION making
Abstract

Whale mortality and strandings have increased in recent years, with deceased whales often brought to landfill. However, the disposal of whale remains offshore holds significant ecological importance and can be a culturally and ethically sensitive approach. Moreover, offshore disposal mitigates potential risks associated with onshore whale remains disposal, such as the spread of diseases and the logistical challenges of managing large carcasses. A challenge with offshore disposal is defining the best release location to avoid the remains drifting ashore or into shipping channels. Here we compared the drift model outputs using a drift forecast model (SARMAP) for a 14 m whale carcass that was moved offshore in southeast Queensland, Australia, and fitted with a satellite tracker over an observation period of 150 h until positioning signal ceased. The modelling was conducted using different ocean products (BLUElink, HYCOM, and Copernicus), which showed a good agreement with the tracked whale carcass, albeit with changing wind conditions and contrasting currents flowing northward along the coast and, further offshore, flowing south. This case study illustrated that wind was the foremost driver of carcass drift due to the surface area above the water surface. The drift forecast simulations allowed for a reliable prediction of the floating whale drift that can assist authorities with decision making. Offshore disposal of whale carcasses is a sustainable practice but requires good planning and scientific assessment. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Global spatial risk assessment of sharks under the footprint of fisheries

Author

Queiroz, Nuno, Humphries, Nicolas E., Couto, Ana, Vedor, Marisa, da Costa, Ivo, Sequeira, Ana M. M., Mucientes, Gonzalo, Santos, António M., Abascal, Francisco J., Abercrombie, Debra L., Abrantes, Katya, Acuña-Marrero, David, Afonso, André S., Afonso, Pedro, Anders, Darrell, Araujo, Gonzalo, Arauz, Randall, Bach, Pascal, Barnett, Adam, Bernal, Diego, Berumen, Michael L., Bessudo Lion, Sandra, Bezerra, Natalia P. A., Blaison, Antonin V., Block, Barbara A., Bond, Mark E., Bonfil, Ramón, Bradford, Russell W., Braun, Camrin D., Brooks, Edward J., Brooks, Annabelle, Brown, Judith, Bruce, Barry D., Byrne, Michael E., Campana, Steven E., Carlisle, Aaron B., Chapman, Demian D., Chapple, Taylor K., Chisholm, John, Clarke, Christopher R., Clua, Eric G., Cochran, Jesse E. M., Crochelet, Estelle C., Dagorn, Laurent, Daly, Ryan, Cortés, Daniel Devia, Doyle, Thomas K., Drew, Michael, Duffy, Clinton A. J., Erikson, Thor, Espinoza, Eduardo, Ferreira, Luciana C., Ferretti, Francesco, Filmalter, John D., Fischer, G. Chris, Fitzpatrick, Richard, Fontes, Jorge, Forget, Fabien, Fowler, Mark, Francis, Malcolm P., Gallagher, Austin J., Gennari, Enrico, Goldsworthy, Simon D., Gollock, Matthew J., Green, Jonathan R., Gustafson, Johan A., Guttridge, Tristan L., Guzman, Hector M., Hammerschlag, Neil, Harman, Luke, Hazin, Fábio H. V., Heard, Matthew, Hearn, Alex R., Holdsworth, John C., Holmes, Bonnie J., Howey, Lucy A., Hoyos, Mauricio, Hueter, Robert E., Hussey, Nigel E., Huveneers, Charlie, Irion, Dylan T., Jacoby, David M. P., Jewell, Oliver J. D., Johnson, Ryan, Jordan, Lance K. B., Jorgensen, Salvador J., Joyce, Warren, Keating Daly, Clare A., Ketchum, James T., Klimley, A. Peter, Kock, Alison A., Koen, Pieter, Ladino, Felipe, Lana, Fernanda O., Lea, James S. E., Llewellyn, Fiona, Lyon, Warrick S., MacDonnell, Anna, Macena, Bruno C. L., Marshall, Heather, McAllister, Jaime D., McAuley, Rory, Meÿer, Michael A., Morris, John J., Nelson, Emily R., Papastamatiou, Yannis P., Patterson, Toby A., Peñaherrera-Palma, Cesar, Pepperell, Julian G., Pierce, Simon J., Poisson, Francois, Quintero, Lina Maria, Richardson, Andrew J., Rogers, Paul J., Rohner, Christoph A., Rowat, David R. L., Samoilys, Melita, Semmens, Jayson M., Sheaves, Marcus, Shillinger, George, Shivji, Mahmood, Singh, Sarika, Skomal, Gregory B., Smale, Malcolm J., Snyders, Laurenne B., Soler, German, Soria, Marc, Stehfest, Kilian M., Stevens, John D., Thorrold, Simon R., Tolotti, Mariana T., Towner, Alison, Travassos, Paulo, Tyminski, John P., Vandeperre, Frederic, Vaudo, Jeremy J., Watanabe, Yuuki Y., Weber, Sam B., Wetherbee, Bradley M., White, Timothy D., Williams, Sean, Zárate, Patricia M., Harcourt, Robert, Hays, Graeme C., Meekan, Mark G., Thums, Michele, Irigoien, Xabier, Eguiluz, Victor M., Duarte, Carlos M., Sousa, Lara L., Simpson, Samantha J., Southall, Emily J., and Sims, David W.

Published
2019
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15. Structure of two-dimensional Fe3O4.

Author

Merte, Lindsay R., Olsson, Pär A. T., Shipilin, Mikhail, Gustafson, Johan, Bertram, Florian, Zhang, Chu, Grönbeck, Henrik, and Lundgren, Edvin

Subjects
FERRIC oxide, DENSITY functional theory, CHEMICAL properties, IRON oxides, X-ray diffraction
Abstract

We have investigated the structure of an ultrathin iron oxide phase grown on Ag(100) using surface x-ray diffraction in combination with Hubbard-corrected density functional theory (DFT+U) calculations. The film exhibits a novel structure composed of one close-packed layer of octahedrally coordinated Fe2+ sandwiched between two close-packed layers of tetrahedrally coordinated Fe3+ and an overall stoichiometry of Fe3O4. As the structure is distinct from bulk iron oxide phases and the coupling with the silver substrate is weak, we propose that the phase should be classified as a metastable two-dimensional oxide. The chemical and physical properties are potentially interesting, thanks to the predicted charge ordering between atomic layers, and analogy with bulk ferrite spinels suggests the possibility of synthesis of a whole class of two-dimensional ternary oxides with varying electronic, optical, and chemical properties. [ABSTRACT FROM AUTHOR]

Published
2020
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16. Formation of Epitaxial PdO(100) During the Oxidation of Pd(100).

Author

Mehar, Vikram, Edström, Helen, Shipilin, Mikhail, Hejral, Uta, Wu, Chengjun, Kadiri, Aravind, Albertin, Stefano, Hagman, Benjamin, von Allmen, Kim, Wiegmann, Tim, Pfaff, Sebastian, Drnec, Jakub, Zetterberg, Johan, Lundgren, Edvin, Merte, Lindsay R., Gustafson, Johan, and Weaver, Jason F.

Published
2023
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21. High Energy surface x-ray diffraction applied to model catalyst surfaces at work

Author

Hejral, Uta, Shipilin, Mikhail, Gustafson, Johan, Stierle, Andreas, and Lundgren, Edvin

Subjects
ddc:530
Abstract

Journal of physics / Condensed matter 33(7), 073001 (2020). doi:10.1088/1361-648X/abb17c, Catalysts are materials that accelerate the rate of a desired chemical reaction. As such, theyconstitute an integral part in many applications ranging from the production of fine chemicalsin chemical industry to exhaust gas treatment in vehicles. Accordingly, it is of utmosteconomic interest to improve catalyst efficiency and performance, which requires anunderstanding of the interplay between the catalyst structure, the gas phase and the catalyticactivity under realistic reaction conditions at ambient pressures and elevated temperatures. Inrecent years efforts have been made to increasingly develop techniques that allow forinvestigating model catalyst samples under conditions closer to those of real technicalcatalysts. One of these techniques is high energy surface x-ray diffraction (HESXRD), whichuses x-rays with photon energies typically in the range of 70–80 keV. HESXRD allows a fastdata collection of three dimensional reciprocal space for the structure determination of modelcatalyst samples under operando conditions and has since been used for the investigation of anincreasing number of different model catalysts. In this article we will review generalconsiderations of HESXRD including its working principle for different model catalystsamples and the experimental equipment required. An overview over HESXRD investigationsperformed in recent years will be given, and the advantages of HESXRD with respect to itsapplication to different model catalyst samples will be presented. Moreover, the combinationof HESXRD with other operando techniques such as in situ mass spectrometry, planarlaser-induced fluorescence and surface optical reflectance will be discussed. The article willclose with an outlook on future perspectives and applications of HESXRD., Published by IOP Publ., Bristol

Published
2020
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22. Preface

Author

Hulteberg, Christian, Odenbrand, Ingemar, Gustafson, Johan, Brandin, Jan, and Lundgren, Edvin

Published
2017
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24. Optical demonstration of crystallography and reciprocal space using laser diffraction from Au microdisc arrays.

Author

Chayanun, Lert, Gustafson, Johan, and Wallentin, Jesper

Subjects
*CRYSTAL optics, *SOLID state physics, *SEMICONDUCTOR manufacturing, *MATERIALS science, *CRYSTALLOGRAPHY
Abstract

Crystallography is an invaluable tool in materials science, solid state physics and protein science. Understanding crystallography requires grasping the powerful but abstract concept of reciprocal space. Here a simple but insightful experiment using a laser pointer and Au microdisc arrays to explore and illustrate Bragg diffraction and reciprocal space is demonstrated. The Au microdisc arrays were manufactured using standard semiconductor fabrication techniques. The flexibility of the array design allows the demonstration of basic concepts such as lattice and atomic form factor, but also more advanced ones such as quasicrystal and shape function. [ABSTRACT FROM AUTHOR]

Published
2022
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25. Structure-function relationship for $CO_{2}$ methanation over ceria supported Rh and Ni catalysts at atmospheric pressure conditions

Author

Martin, Natalia, Hemmingsson, Felix, Schaefer, Andreas, Ek, Martin, Merte, Lindsay Richard, Hejral, Uta, Gustafson, Johan, Skoglundh, Magnus, Dippel, Ann-Christin, Gutowski, Olof, Bauer, Matthias, and Carlsson, Per-Anders

Subjects
ddc:540
Abstract

Catalysis science & technology 9, 1644 - 1653 (2019). doi:10.1039/C8CY02097C, In situ structural and chemical state characterization of Rh/CeO$_2$ and Ni/CeO$_2$ catalysts during atmospheric pressure CO$_2$ methanation has been performed by a combined array of time-resolved analytical techniques including ambient-pressure X-ray photoelectron spectroscopy, high-energy X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy. The ceria phase is partially reduced during the CO$_2$ methanation and in particular Ce$^{3+}$ species seem to facilitate activation of CO$_2$ molecules. The activated CO2 molecules then react with atomic hydrogen provided from H$_2$ dissociation on Rh and Ni sites to form formate species. For the most active catalyst (Rh/CeO$_2$), transmission electron microscopy measurements show that the Rh nanoparticles are small (average 4 nm, but with a long tail towards smaller particles) due to a strong interaction between Rh particles and the ceria phase. In contrast, larger nanoparticles were observed for the Ni/CeO$_2$ catalyst (average 6 nm, with no crystallites below 5 nm found), suggesting a weaker interaction with the ceria phase. The higher selectivity towards methane of Rh/CeO$_2$ is proposed to be due to the stronger metal–support interaction., Published by RSC Publ., London

Published
2019
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26. Structure–function relationship during $\mathrm{CO_{2}}$ methanation over $\mathrm{Rh/Al_{2}O_{3}}$ and $\mathrm{Rh/SiO_{2}}$ catalysts under atmospheric pressure conditions

Author

Martin, Natalia, Hemmingsson, Felix, Wang, Xueting, Merte, Lindsay R., Hejral, Uta, Gustafson, Johan, Skoglundh, Magnus, Meira, Debora Motta, Dippel, Ann-Christin, Gutowski, Olof, Bauer, Matthias, and Carlsson, Per-Anders

Subjects
ddc:540
Abstract

Catalysis science & technology 8(10), 2686 - 2696 (2018). doi:10.1039/C8CY00516H, The effect of the support material and chemical state of Rh in Rh/A$_2$O$_3$ and Rh/SiO$_2$ model catalysts during CO$_2$ hydrogenation were studied by a combined array of in situ characterisation techniques including diffuse reflectance infrared Fourier transform spectroscopy, energy-dispersive X-ray absorption spectroscopy and high-energy X-ray diffraction at 250–350 °C and atmospheric pressure. CO$_2$ methanation proceeds via intermediate formation of adsorbed CO species on metallic Rh, likely followed by their hydrogenation to methane. The linearly-bonded CO species is suggested to be a more active precursor in the hydrogenation compared to the bridge-bonded species, which seems to be related to particle size effects: for larger particles mainly the formation of inactive bridge-bonded CO species takes place. Further, analysis of the chemical state of Rh under the reaction conditions reveal a minor formation of RhOx from dissociation of CO$_2$, which is a consequence of the increased activity observed over the Rh/Al$_2$O$_3$ catalyst., Published by RSC Publ., London

Published
2018
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27. HIPPIE: a new platform for ambient‐pressure X‐ray photoelectron spectroscopy at the MAX IV Laboratory.

Author

Zhu, Suyun, Scardamaglia, Mattia, Kundsen, Jan, Sankari, Rami, Tarawneh, Hamed, Temperton, Robert, Pickworth, Louisa, Cavalca, Filippo, Wang, Chunlei, Tissot, Héloïse, Weissenrieder, Jonas, Hagman, Benjamin, Gustafson, Johan, Kaya, Sarp, Lindgren, Fredrik, Källquist, Ida, Maibach, Julia, Hahlin, Maria, Boix, Virginia, and Gallo, Tamires

Subjects
X-ray photoelectron spectroscopy, PHOTON flux, POLARIZED photons, MASS spectrometry, IR spectrometers, GAS chromatography/Mass spectrometry (GC-MS), LIQUID chromatography-mass spectrometry
Abstract

HIPPIE is a soft X‐ray beamline on the 3 GeV electron storage ring of the MAX IV Laboratory, equipped with a novel ambient‐pressure X‐ray photoelectron spectroscopy (APXPS) instrument. The endstation is dedicated to performing in situ and operando X‐ray photoelectron spectroscopy experiments in the presence of a controlled gaseous atmosphere at pressures up to 30 mbar [1 mbar = 100 Pa] as well as under ultra‐high‐vacuum conditions. The photon energy range is 250 to 2200 eV in planar polarization and with photon fluxes >1012 photons s−1 (500 mA ring current) at a resolving power of greater than 10000 and up to a maximum of 32000. The endstation currently provides two sample environments: a catalysis cell and an electrochemical/liquid cell. The former allows APXPS measurements of solid samples in the presence of a gaseous atmosphere (with a mixture of up to eight gases and a vapour of a liquid) and simultaneous analysis of the inlet/outlet gas composition by online mass spectrometry. The latter is a more versatile setup primarily designed for APXPS at the solid–liquid (dip‐and‐pull setup) or liquid–gas (liquid microjet) interfaces under full electrochemical control, and it can also be used as an open port for adhoc‐designed non‐standard APXPS experiments with different sample environments. The catalysis cell can be further equipped with an IR reflection–absorption spectrometer, allowing for simultaneous APXPS and IR spectroscopy of the samples. The endstation is set up to easily accommodate further sample environments. [ABSTRACT FROM AUTHOR]

Published
2021
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29. Structure of the SnO2(110)-(4 x 1) Surface

Author

Merte, Lindsay R., Jorgensen, Mathias S., Pussi, Katariina, Gustafson, Johan, Shipilin, Mikhail, Schaefer, Andreas, Zhang, Chu, Rawle, Jonathan, Nicklin, Chris, Thornton, Geoff, Lindsay, Robert, Hammer, Bjork, and Lundgren, Edvin

Subjects
INTERFACE, 4X1, RECONSTRUCTIONS, LEED, METAL-OXIDES, SCIENCE, DIFFRACTION, OXYGEN-DEFICIENT SNO2(110), SNO2
Abstract

Using surface x-ray diffraction (SXRD), quantitative low-energy electron diffraction (LEED), and density-functional theory (DFT) calculations, we have determined the structure of the (4 x 1) reconstruction formed by sputtering and annealing of the SnO2(110) surface. We find that the reconstruction consists of an ordered arrangement of Sn3O3 clusters bound atop the bulk-terminated SnO2(110) surface. The model was found by application of a DFT-based evolutionary algorithm with surface compositions based on SXRD, and shows excellent agreement with LEED and with previously published scanning tunneling microscopy measurements. The model proposed previously consisting of inplane oxygen vacancies is thus shown to be incorrect, and our result suggests instead that Sn(II) species in interstitial positions are the more relevant features of reduced SnO2(110) surfaces.

Published
2017
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30. The influence of incommensurability on the long-range periodicity of the Pd(100)-($\sqrt{5} \times \sqrt{5}$)R27°-PdO(101)

Author

Shipilin, Mikhail, Stierle, Andreas, Merte, Lindsay R., Gustafson, Johan, Hejral, Uta, Martin, Natalia M., Zhang, Chu, Franz, Dirk, Kilic, Volkan, and Lundgren, Edvin

Subjects
ddc:540
Abstract

Surface science 660, 1 - 8 (2017). doi:10.1016/j.susc.2017.01.009, he structural model of the ($\sqrt{5} \times \sqrt{5}$)R27°-PdO(101) surface oxide grown on Pd(100) has been proposed and refined by a number of authors over more than a decade. In the current contribution we discuss the long-range periodicity of this structure arising along one of the crystallographic directions due to its incommensurability with the substrate. Analyzing the results of surface sensitive diffraction studies, we determined a slight distortion of the previously reported perfect ($\sqrt{5} \times \sqrt{5}$)R27° surface oxide unit cell. Considering it, we were able to achieve both qualitatively and quantitatively better fit to the experimental diffraction data than it was possible for the perfect structure. Further, taking into account the experimentally obtained scanning tunneling microscopy data and closely examining high-resolution patterns recorded by means of high-energy surface X-ray diffraction, we developed a qualitative structural model based on a larger non-orthogonal surface unit cell to shed more light on the long-range order of the PdO(101) surface oxide. The model comprises a shift of the atoms of the PdO perpendicularly to the direction of the incommensurability to correct for it. This structural model reproduces the fine details of the high-resolution diffraction patterns and qualitatively explains the periodic stripes of structural distortion observed in the images recorded by a scanning tunneling microscope., Published by Elsevier, Amsterdam

Published
2017
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31. Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets through a Transient CO‐O Complex**.

Author

Garcia‐Martinez, Fernando, García‐Fernández, Carlos, Simonovis, Juan Pablo, Hunt, Adrian, Walter, Andrew, Waluyo, Iradwikanari, Bertram, Florian, Merte, Lindsay R., Shipilin, Mikhail, Pfaff, Sebastian, Blomberg, Sara, Zetterberg, Johan, Gustafson, Johan, Lundgren, Edvin, Sánchez‐Portal, Daniel, Schiller, Frederik, and Ortega, J. Enrique

Subjects
CATALYTIC oxidation, PHOTOEMISSION, TRANSITION metals, METALLIC surfaces, PLATINUM, CHEMISORPTION
Abstract

The catalytic oxidation of CO on transition metals, such as Pt, is commonly viewed as a sharp transition from the CO‐inhibited surface to the active metal, covered with O. However, we find that minor amounts of O are present in the CO‐poisoned layer that explain why, surprisingly, CO desorbs at stepped and flat Pt crystal planes at once, regardless of the reaction conditions. Using near‐ambient pressure X‐ray photoemission and a curved Pt(111) crystal we probe the chemical composition at surfaces with variable step density during the CO oxidation reaction. Analysis of C and O core levels across the curved crystal reveals that, right before light‐off, subsurface O builds up within (111) terraces. This is key to trigger the simultaneous ignition of the catalytic reaction at different Pt surfaces: a CO‐Pt‐O complex is formed that equals the CO chemisorption energy at terraces and steps, leading to the abrupt desorption of poisoning CO from all crystal facets at the same temperature. [ABSTRACT FROM AUTHOR]

Published
2020
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37. Fabrication and Characterization of Sculptured Thin Silver Films

Author

Gustafson, Johan

Subjects
GLAD, nanocolumns, nanospirals, Glancing angle deposition, STF, sculptured thin films, Silver thin films
Abstract

In this work samples with silver nanocolumnar structures were successfully fabricated by glancingangle deposition. From SEM investigations of the samples it is concluded that distinct andseparated nanocolumns can be grown without pre-patterned substrates using this method (givensuitable deposition conditions). The sample that exhibits the most distinct and well separatedcolumns was modelled using HFSS with optical properties of silver in nanocolumns obtained bymeasurements on the samples grown by glancing angle deposition, thin enough to not havedeveloped columns. From numerical calculations it was shown that the unit cell arrangement of thecolumns has a large influence on the optical characteristics. It was found that a diamond-like unitcell designed as two identical square lattices shifted by half the lattice spacing in one direction and2-1/2 times the lattice spacing of the other direction gives the best and a fair agreement to theexperimental ellipsometry data. Based on this model calculations were made to determine thewavelength dependent average local current exhibited in the columns as well as the currentdensity. This study showed the occurrence of broadbanded plasmon resonances of longitudinalmode at λ=1363 nm and of transverse mode at λ=545 nm. It was also shown that the opticalcharacteristics are strongly polarization dependent as is expected for such anisotropic samples.

Published
2013

38. Combining synchrotron light with laser technology in catalysis research.

Author

Blomberg, Sara, Zetterberg, Johan, Gustafson, Johan, Zhou, Jianfeng, Shipilin, Mikhail, Pfaff, Sebastian, Hejral, Uta, Carlsson, Per-Anders, Gutowski, Olof, Bertram, Florian, and Lundgren, Edvin

Subjects
SYNCHROTRON radiation, CATALYSIS research, X-ray diffraction, SURFACE dynamics, SURFACE structure, OXIDATION of carbon monoxide
Abstract

High‐energy surface X‐ray diffraction (HESXRD) provides surface structural information with high temporal resolution, facilitating the understanding of the surface dynamics and structure of the active phase of catalytic surfaces. The surface structure detected during the reaction is sensitive to the composition of the gas phase close to the catalyst surface, and the catalytic activity of the sample itself may affect the surface structure, which in turn may complicate the assignment of the active phase. For this reason, planar laser‐induced fluorescence (PLIF) and HESXRD have been combined during the oxidation of CO over a Pd(100) crystal. PLIF complements the structural studies with an instantaneous two‐dimensional image of the CO2 gas phase in the vicinity of the active model catalyst. Here the combined HESXRD and PLIF operando measurements of CO oxidation over Pd(100) are presented, allowing for an improved assignment of the correlation between sample structure and the CO2 distribution above the sample surface with sub‐second time resolution. [ABSTRACT FROM AUTHOR]

Published
2018
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39. Thermal reduction of ceria nanostructures on rhodium(111) and re-oxidation by CO2.

Author

Schaefer, Andreas, Hagman, Benjamin, Höcker, Jan, Hejral, Uta, Flege, Jan Ingo, and Gustafson, Johan

Abstract

The thermal reduction of cerium oxide nanostructures deposited on a rhodium(111) single crystal surface and the re-oxidation of the structures by exposure to CO2 were investigated. Two samples are compared: a rhodium surface covered to ≈60% by one to two O–Ce–O trilayer high islands and a surface covered to ≈65% by islands of four O–Ce–O trilayer thickness. Two main results stand out: (1) the thin islands reduce at a lower temperature (870–890 K) and very close to Ce2O3, while the thicker islands need higher temperature for reduction and only reduce to about CeO1.63 at a maximum temperature of 920 K. (2) Ceria is re-oxidized by CO2. The rhodium surface promotes the re-oxidation by splitting the CO2 and thus providing atomic oxygen. The process shows a clear temperature dependence. The maximum oxidation state of the oxide reached by re-oxidation with CO2 differs for the two samples, showing that the thinner structures require a higher temperature for re-oxidation with CO2. Adsorbed carbon species, potentially blocking reactive sites, desorb from both samples at the same temperature and cannot be the sole origin for the observed differences. Instead, an intrinsic property of the differently sized CeOx islands must be at the origin of the observed temperature dependence of the re-oxidation by CO2. [ABSTRACT FROM AUTHOR]

Published
2018
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41. Value of Small Seagrass Patches as Tidal Flow-Refuges

Author

Gustafson, Johan Albin

Subjects
Zostera capricorni, Tidal flow refuges, Fish ecology in seagrass meadows, Seagrass meadows
Abstract

One central challenge in the study of seagrass meadows is explaining the abundance and diversity of nekton associated with these productive habitats. While many models have been proposed to explain fish use of seagrass habitats, mainly focusing on their nursery and predator-avoidance values based on the complex habitat structure, most empirical studies were conducted on relatively large patches using catch data collected from invasive capture methods. Seagrass meadows on peri-urban coasts, however, continually being threatened and fragmented, while invasive surveying techniques could bias fish abundance data. This thesis aims to determine if small remnant Zostera capricorni patches in a peri-urban estuary provide small mobile fish with a flow-refuge within a strong tidal flow environment, using non-invasive video surveying techniques to monitor fish abundance and behaviour. The hydrodynamic characteristics of three small patches of Z. capricorni were measured using in situ deployment of Acoustic Doppler Current Profilers (ADCP) at the front and rear of the patches during tidal current flow between 20 and 30 cm/s. Seagrass canopies of densities and morphologies covered by these patches significantly baffled the free-stream flow (X), creating a near-zero, turbulent free, within-canopy hydraulic environment 0.25m from the canopy’s leading edge. Flows were deflected over the canopy surface causing the leaves to bend, compressing the canopy and thereby reducing the vertical flux under high flows. While lower flows were still significantly reduced, a small vertical flux occurred, with large turbulent eddies generating from the canopy friction. The hydraulic environment behind the patch was significantly different to that at the patch’s front – characterised by near zero flows and turbulent fluctuations (at 0m), and flow velocities increasing with downstream distance. This effect was noticeable due to the velocity above the canopy being significantly reduced from flows above the canopy (fast). This difference diminished with downstream distance, gradually resembling the front profile. The rear environment close to the patch edge matched those of other flow-refuges.

Published
2012
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42. Optical Studies and Micro-Structure Modeling of the Circular-Polarizing Scarab Beetles Cetonia aurata, Potosia cuprea, Liocola marmorata

Author

Gustafson, Johan

Subjects
Ellipsometry, Circular-Polarizing, Physics, Liocola marmorata, Fysik, Micro-Structure Modeling, Scarab beetles, Optical Studies, RC2, Cetonia aurata, Potosia cuprea, Guldbaggar
Abstract

The aim of the work presented in this thesis is to contribute to a fundamental understanding of polarizing phenomena in some scarab beetles. The aim is also to study the beetle structures as inspiration in fabrication of artificially sculptured films. The three investigated species Cetonia aurata, Potosia cuprea and Liocola marmorata are of the family Scarabaediae and subfamily Cetoniianae (Guldbaggar). They were all collected at Swedish locations and are the only species of Cetoniinae scarabs in Sweden. This work reports on their optical properties represented by Mueller matrix elements, degree of polarization data and trace curves in the Cartesian complex plane representation of polarized light. From these results we verifyan earlier structural model for the Cetonia aurata and make way for similar models of the other two species. The ellipsometer used in this work is of dual rotating compensator type from which the complete Mueller-matrix for the medium examined can be obtained. The ellipsometric measurements were conducted on the scutellum for four different angles of incidence, 45°, 55°, 65° and 75° over a wave-length range of 245-1000 nm. Common for all examined species is that left polarization is observed in the wavelength range of 400 800 nm. For most of these species the polarization state is close to circular at some wavelengths especially at smaller angles of incidence. In general the degree of polarization is high (above 50%) when the polarization is near-circular. The degree of polarization also shows a clear dependence on the angle of incidence. The earlier model for Cetonia aurata shows a good agreement with the experimental data of this work. The model is also found as a good basis to work from to create models for the other two species.

Published
2010

44. Step dynamics and oxide formation during CO oxidation over a vicinal Pd surface.

Author

Shipilin, Mikhail, Gustafson, Johan, Zhang, Chu, Merte, Lindsay Richard, and Lundgren, Edvin

Abstract

In an attempt to bridge the material and pressure gaps – two major challenges for an atomic scale understanding of heterogeneous catalysis – we employed high-energy surface X-ray diffraction as a tool to study the Pd(553) surface in situ under changing reaction conditions during CO oxidation. The diffraction patterns recorded under CO rich reaction conditions are characteristic for the metallic state of the surface. In an environment with low excess of O2 over the reaction stoichiometry, the surface seems to accommodate oxygen atoms along the steps forming one or several subsequent adsorbate structures and rapidly transforms into a combination of (332), (111) and (331) facets likely providing the room for the formation of a surface oxide. For the case of large excess of O2, the diffraction data show the presence of a multilayer PdO with the [101] crystallographic direction parallel to the [111] and the [331] directions of the substrate. The reconstructions in O2 excess are to a large extent similar to those previously reported for pure O2 exposures by Westerström et al. [R. Westerström et al., Phys. Rev. B: Condens. Matter Mater. Phys., 2007, 76, 155410]. [ABSTRACT FROM AUTHOR]

Published
2016
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45. Tuning the Reactivity of Ultrathin Oxides: NO Adsorption on Monolayer FeO(111).

Author

Merte, Lindsay R., Heard, Christopher J., Zhang, Feng, Choi, Juhee, Shipilin, Mikhail, Gustafson, Johan, Weaver, Jason F., Grönbeck, Henrik, and Lundgren, Edvin

Subjects
MONOMOLECULAR films, IRON oxides, NITRIC oxide, ADSORPTION (Chemistry), REACTIVITY (Chemistry), HETEROGENEOUS catalysis
Abstract

Ultrathin metal oxides exhibit unique chemical properties and show promise for applications in heterogeneous catalysis. Monolayer FeO films supported on metal surfaces show large differences in reactivity depending on the metal substrate, potentially enabling tuning of the catalytic properties of these materials. Nitric oxide (NO) adsorption is facile on silver-supported FeO, whereas a similar film grown on platinum is inert to NO under similar conditions. Ab initio calculations link this substrate-dependent behavior to steric hindrance caused by substrate-induced rumpling of the FeO surface, which is stronger for the platinum-supported film. Calculations show that the size of the activation barrier to adsorption caused by the rumpling is dictated by the strength of the metal-oxide interaction, offering a straightforward method for tailoring the adsorption properties of ultrathin films. [ABSTRACT FROM AUTHOR]

Published
2016
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46. The structure–function relationship for alumina supported platinum during the formation of ammonia from nitrogen oxide and hydrogen in the presence of oxygen.

Author

Adams, Emma Catherine, Merte, Lindsay Richard, Hellman, Anders, Skoglundh, Magnus, Gustafson, Johan, Bendixen, Eva Charlotte, Gabrielsson, Pär, Bertram, Florian, Evertsson, Jonas, Zhang, Chu, Carlson, Stefan, and Carlsson, Per-Anders

Abstract

We study the structure–function relationship of alumina supported platinum during the formation of ammonia from nitrogen oxide and dihydrogen by employing in situ X-ray absorption and Fourier transform infrared spectroscopy. Particular focus has been directed towards the effect of oxygen on the reaction as a model system for emerging technologies for passive selective catalytic reduction of nitrogen oxides. The suppressed formation of ammonia observed as the feed becomes net-oxidizing is accompanied by a considerable increase in the oxidation state of platinum as well as the formation of surface nitrates and the loss of NH-containing surface species. In the presence of (excess) oxygen, the ammonia formation is proposed to be limited by weak interaction between nitrogen oxide and the oxidized platinum surface. This leads to a slow dissociation rate of nitrogen oxide and thus low abundance of the atomic nitrogen surface species that can react with the adsorbed hydrogen species. In this case the consumption of hydrogen through the competing water formation reaction and decomposition/oxidation of ammonia are of less importance for the net ammonia formation. [ABSTRACT FROM AUTHOR]

Published
2016
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47. An in situ sample environment reaction cell for spatially resolved x-ray absorption spectroscopy studies of powders and small structured reactors.

Author

Chu Zhang, Gustafson, Johan, Merte, Lindsay R., Evertsson, Jonas, Norén, Katarina, Carlson, Stefan, Svensson, Håkan, and Carlsson, Per-Anders

Subjects
*X-ray spectroscopy, *POWDERS, *MASS spectrometry, *GAS flow, *X-ray absorption near edge structure
Abstract

An easy-to-use sample environment reaction cell for X-ray based in situ studies of powders and small structured samples, e.g., powder, pellet, and monolith catalysts, is described. The design of the cell allows for flexible use of appropriate X-ray transparent windows, shielding the sample from ambient conditions, such that incident X-ray energies as low as 3 keV can be used. Thus, in situ X-ray absorption spectroscopy (XAS) measurements in either transmission or fluorescence mode are facilitated. Total gas flows up to about 500 mln/min can be fed while the sample temperature is accurately controlled (at least) in the range of 25-500 °C. The gas feed is composed by a versatile gas-mixing system and the effluent gas flow composition is monitored with mass spectrometry (MS). These systems are described briefly. Results from simultaneous XAS/MS measurements during oxidation of carbon monoxide over a 4% Pt/Al2O3 powder catalyst are used to illustrate the system performance in terms of transmission XAS. Also, 2.2% Pd/Al2O3 and 2% Ag - Al2O3 powder catalysts have been used to demonstrate X-ray absorption near-edge structure (XANES) spectroscopy in fluorescence mode. Further, a 2% Pt/Al2O3 monolith catalyst was used ex situ for transmission XANES. The reaction cell opens for facile studies of structure-function relationships for model as well as realistic catalysts both in the form of powders, small pellets, and coated or extruded monoliths at near realistic conditions. The applicability of the cell for X-ray diffraction measurements is discussed. [ABSTRACT FROM AUTHOR]

Published
2015
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48. THE IRRELEVANCE OF THE DIACHRONIC MONEY-PUMP ARGUMENT FOR ACYCLICITY.

Author

GUSTAFSON, JOHAN E.

Subjects
*RELEVANCE (Philosophy), *HISTORICAL linguistics, *REASONING, *ARGUMENT, *RATIONAL choice theory
Abstract

The article offers the author's insight on the irrelevance of the objections to the diachronic money-pump argument for acyclicity, claiming that diachronic money-pump argument is more direct synchronic argument if it is cogent. Topics included Frederick Schick who leveled an influential objection to the argument, rational choice, and synchronic version of money pump argument.

Published
2013

49. Corrigendum: Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets through a Transient CO‐O Complex.

Author

Garcia‐Martinez, Fernando, García‐Fernández, Carlos, Simonovis, Juan Pablo, Hunt, Adrian, Walter, Andrew, Waluyo, Iradwikanari, Bertram, Florian, Merte, Lindsay R., Shipilin, Mikhail, Pfaff, Sebastian, Blomberg, Sara, Zetterberg, Johan, Gustafson, Johan, Lundgren, Edvin, Sánchez‐Portal, Daniel, Schiller, Frederik, and Ortega, J. Enrique

Subjects
CATALYTIC oxidation, CURVED surfaces, PHOTOEMISSION
Abstract

CO oxidation, curved surfaces, ignition, near-ambient pressure photoemission, subsurface oxygen Keywords: CO oxidation; curved surfaces; ignition; near-ambient pressure photoemission; subsurface oxygen EN CO oxidation curved surfaces ignition near-ambient pressure photoemission subsurface oxygen 11021 11021 1 05/06/21 20210510 NES 210510 In this Research Article on page 20039, the correct energies for XPS peaks corresponding to Terrace-Top (TT) and Terrace-Bridge (TB) are 286.6 eV and 285.9 eV, respectively. Corrigendum: Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets through a Transient CO-O Complex. [Extracted from the article]

Published
2021
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50. Berichtigung: Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets through a Transient CO‐O Complex.

Author

Garcia‐Martinez, Fernando, García‐Fernández, Carlos, Simonovis, Juan Pablo, Hunt, Adrian, Walter, Andrew, Waluyo, Iradwikanari, Bertram, Florian, Merte, Lindsay R., Shipilin, Mikhail, Pfaff, Sebastian, Blomberg, Sara, Zetterberg, Johan, Gustafson, Johan, Lundgren, Edvin, Sánchez‐Portal, Daniel, Schiller, Frederik, and Ortega, J. Enrique

Subjects
CATALYTIC oxidation, CURVED surfaces, PHOTOEMISSION
Abstract

Berichtigung: Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets through a Transient CO-O Complex CO oxidation, curved surfaces, ignition, near-ambient pressure photoemission, subsurface oxygen Keywords: CO oxidation; curved surfaces; ignition; near-ambient pressure photoemission; subsurface oxygen EN CO oxidation curved surfaces ignition near-ambient pressure photoemission subsurface oxygen 11121 11121 1 05/06/21 20210510 NES 210510 In this Research Article on page 20214, the correct energies for XPS peaks corresponding to Terrace-Top (TT) and Terrace-Bridge (TB) are 286.6 eV and 285.9 eV, respectively. [Extracted from the article]

Published
2021
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