| 1. |
- Amann, Peter, et al.
(författare)
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A high-pressure x-ray photoelectron spectroscopy instrument for studies of industrially relevant catalytic reactions at pressures of several bars
- 2019
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 90:10
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Tidskriftsartikel (refereegranskat)abstract
- We present a new high-pressure x-ray photoelectron spectroscopy system dedicated to probing catalytic reactions under realistic conditions at pressures of multiple bars. The instrument builds around the novel concept of a "virtual cell" in which a gas flow onto the sample surface creates a localized high-pressure pillow. This allows the instrument to be operated with a low pressure of a few millibar in the main chamber, while simultaneously a local pressure exceeding 1 bar can be supplied at the sample surface. Synchrotron based hard x-ray excitation is used to increase the electron mean free path in the gas region between sample and analyzer while grazing incidence <5 degrees close to total external refection conditions enhances surface sensitivity. The aperture separating the high-pressure region from the differential pumping of the electron spectrometer consists of multiple, evenly spaced, micrometer sized holes matching the footprint of the x-ray beam on the sample. The resulting signal is highly dependent on the sample-to-aperture distance because photoemitted electrons are subject to strong scattering in the gas phase. Therefore, high precision control of the sample-to-aperture distance is crucial. A fully integrated manipulator allows for sample movement with step sizes of 10 nm between 0 and -5 mm with very low vibrational amplitude and also for sample heating up to 500 degrees C under reaction conditions. We demonstrate the performance of this novel instrument with bulk 2p spectra of a copper single crystal at He pressures of up to 2.5 bars and C1s spectra measured in gas mixtures of CO + H-2 at pressures of up to 790 mbar. The capability to detect emitted photoelectrons at several bars opens the prospect for studies of catalytic reactions under industrially relevant operando conditions.
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| 2. |
- Borbely, Gabor, 1981-, et al.
(författare)
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The role of neurokinin A in corneal wound repair
- 2015
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Ingår i: Investigative Ophthalmology and Visual Science. - Rockville, MD, USA : Assoc Research Vision Ophthalmology Inc. - 0146-0404 .- 1552-5783. ; 56:7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Bäckström, Erik, 1983-, et al.
(författare)
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Storing keV negative ions for an hour : The lifetime of the metastable 2P1/2 level in 32S−
- 2015
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:14
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Tidskriftsartikel (refereegranskat)abstract
- We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p 5 P 2 o 1/2 →3p 5 P 2 o 3/2 spontaneous radiative decay in S − 32 to be 503±54 sec . This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10 −14 mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ from the only available theoretical prediction.
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| 4. |
- Chartkunchand, Kiattichart C., et al.
(författare)
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Dianion diagnostics in DESIREE : High-sensitivity detection of C-n(2-) from a sputter ion source
- 2018
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 89:3
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Tidskriftsartikel (refereegranskat)abstract
- A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, C-n(2-), with n = 7-24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot C-n(2-) dianions injected into the ring yielded C-n(2-) anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90 degrees analyzing magnet on the ion injection line reflect the production of internally hot C-7(2-) - C-24(2-) dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C-6(2-) was found while there was a clear C-7(2-) signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C-6(2-) signal that is two orders-of-magnitude smaller than that for C-7(2-). In addition, CnO2- and CnCu2- dianions were detected.
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| 5. |
- Chartkunchand, Kiattichart C., et al.
(författare)
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Radiative lifetimes of the bound excited states of Pt-
- 2016
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Ingår i: Physical Review A - Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 94:3
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 American Physical Society.The intrinsic radiative lifetimes of the 5d106sS1/22 and 5d96s2 D3/22 bound excited states in the platinum anion Pt- have been studied at cryogenic temperatures at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at Stockholm University. The intrinsic lifetime of the higher-lying 5d106s S1/22 state was measured to be 2.54±0.10s, while only a lifetime in the range of 50-200 ms could be estimated for the 5d96s2 D3/22 fine-structure level. The storage lifetime of the Pt- ion beam was measured to be a little over 15 min at a ring temperature of 13K. The present study reports the lifetime of an atomic negative ion in an excited bound state with an electron configuration different from that of the ground state.
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| 6. |
- Hall, Patrik, et al.
(författare)
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Greening the Street-Level Procurer: Challenges in the Strongly Decentralized Swedish System
- 2016
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Ingår i: Journal of Consumer Policy. - : Springer Science and Business Media LLC. - 0168-7034 .- 1573-0700. ; 39:4, s. 467-483
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Tidskriftsartikel (refereegranskat)abstract
- This article investigates the every-day street-level practice of green public procurement (GPP) in Sweden, a country with one of the most decentralized systems of public administration within the European Union (EU). The street-level procurement officers in Swedish local and regional government are in charge of purchases estimated to represent between 10% and 15% of Sweden’s GDP. This article examines the constraining and enabling factors behind the individual procurement officer’s choice of green procurement in textiles and clothing through a combination of qualitative interviews and a review of documentary sources. The analysis shows that while indirect support through European and national soft regulation and policy advice is imperative for “greening” procurement, the direct factors which influence the local outcome of GPP comprises factors on the local level: political commitment and environmental knowledge, the organizational structure of local government and the local interpretation of the regulatory framework. This study shows that a decentralized structure has possibilities of furthering ambitions of buying green if there are committed politicians and public officials, an optimal level of internal centralisation and an external support structure of knowledge and enabling rules. © 2015, Springer Science+Business Media New York.
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| 7. |
- Hall, Patrik, et al.
(författare)
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Innovation Policy as Performativity : the Case of Sweden
- 2017
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Ingår i: International Journal of Public Administration. - : Taylor & Francis. - 0190-0692 .- 1532-4265. ; 40:4, s. 305-316
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Tidskriftsartikel (refereegranskat)abstract
- This article analyzes how the idea of “innovationism” in Sweden has generated a new kind of idea-driven policy around the creation of innovative regional policy. In contrast to similar policies in this area, this policy does not manifest itself through traditional instruments, but evolves through symbolic and ritual performances, in particular through events and conferences. The article asks how this emerging idea has changed the existing institutional formation of sponsoring industrially relevant research. The vision of concerted action between decision-makers within modern innovationism reinforces territorial identity, but it also tends to devolve responsibility to the regional level since concerted action on the national level is hard to obtain. What emerges is a system of governing at a distance where different actors perform their roles according to often academic ideas of innovationism. The study is based on two qualitative studies in Sweden entailing both documentary sources and semi-structured interviews.
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| 8. |
- Kamińska, Magdalena, et al.
(författare)
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Lifetime of the bound excited level in Ni
- 2016
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Ingår i: Physical Review A. - 1050-2947 .- 1094-1622. ; 93:1
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Tidskriftsartikel (refereegranskat)abstract
- The intrinsic lifetime of the upper level in the bound-bound 3d(9) 4s(2) D-2(3/2) -> 3d(9) 4s(2) D-2(5/2) radiative transition in Ni- was measured to be 15.1 +/- 0.4 s. The experiment was performed at cryogenic temperatures in one of the ion-beam storage rings of the Double ElectroStatic Ion Ring ExpEriment facility at Stockholm University. The storage lifetime of the Ni- ion beam was measured to be close to 5 min at a ring temperature of 13 K.
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| 9. |
- Kaminska, M, et al.
(författare)
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Storing keV negative ions for hours: Lifetime measurements in new time domains
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Konferensbidrag (refereegranskat)abstract
- We have used one of the cryogenic ion storage rings of DESIREE to measure the lifetime of the 2P o 1/2 level in the sulfur anion to be 503 ± 43 seconds. This is orders of magnitude longer than any previously measured lifetime in a negatively charged ion.
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| 10. |
- Löfgren, Ingeborg, 1980-
(författare)
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Interpretive Skepticism : Stanley Cavell, New Criticism, and Literary Interpretation
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation explores and analyzes interpretive skepticism in literary theory. It argues that traditional interpretive theories and debates often harbor unacknowledged forms of skeptical thinking and arguments. As these forms of skepticism are seldom recognized as skepticism, the problem tends to remain hidden and unresolved. The dissertation further argues that interpretive skepticism is (i) the result of a philosophical confusion, and (ii) practically harmful when used in order to regulate interpretive practice. Accordingly, a central purpose of the dissertation is to offer an analysis and taxonomy of what interpretive skepticism is. Only once we are in a position to understand and recognize it in its many guises will we be able to criticize and challenge it.The first part of the dissertation thus aims at identifying a specific structure of skeptical reasoning within the theory of literary interpretation. In articulating this taxonomy and analysis, the study builds on the American philosopher Stanley Cavell’s reinterpretation of epistemological skepticism in terms of tragedy, avoidance and repudiation of grammatical criteria. The second part of the study explores, in greater detail, interpretive skepticism within New Criticism. It centers on analyses of two classics within interpretive theory: “The Intentional Fallacy” by Monroe C. Beardsley (and W.K. Wimsatt) and “The Heresy of Paraphrase” by Cleanth Brooks. The study argues that Beardsley becomes both a so-called “skeptical twin” about literary interpretation and a straightforward literary other-minds skeptic with regard to authorial intentions. Brooks, for his part, becomes a straightforward skeptic about poetic interpretation and a “skeptical twin” about poetic meaning. Both theorists are investigated in comparison with Cavell’s explorations of the themes of intention, overinterpretation, fraudulence, modernism, and aesthetic judgment in art, literature and criticism. Despite these skeptical findings, the study also argues that there are important similarities between Cavell’s non-skeptical approach to literature and criticism, and New Critical “close reading.”The dissertation concludes with a chapter that leaves the confines of the New Critical idiom to explore interpretive skepticism within the tradition of so-called “hermeneutics of suspicion.” Through readings of Susan Sontag, Eve Kosofsky Sedgwick, and Cora Diamond, it argues that suspicious or paranoid hermeneutics is not skeptical in itself but can become so through the skeptical temptations of dogmatism, authoritarianism, and fraudulence.
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