| 1. |
- Amano, T., et al.
(författare)
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Observational Evidence for Stochastic Shock Drift Acceleration of Electrons at the Earth's Bow Shock
- 2020
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 124:6
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Tidskriftsartikel (refereegranskat)abstract
- The first-order Fermi acceleration of electrons requires an injection of electrons into a mildly relativistic energy range. However, the mechanism of injection has remained a puzzle both in theory and observation. We present direct evidence for a novel stochastic shock drift acceleration theory for the injection obtained with Magnetospheric Multiscale observations at the Earth's bow shock. The theoretical model can explain electron acceleration to mildly relativistic energies at high-speed astrophysical shocks, which may provide a solution to the long-standing issue of electron injection.
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| 2. |
- Fennell, David A., et al.
(författare)
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Tourism, animals & the vacant niche : a scoping review and pedagogical agenda
- 2024
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Ingår i: Current Issues in Tourism. - : Routledge. - 1368-3500 .- 1747-7603. ; , s. 1-29
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Tidskriftsartikel (refereegranskat)abstract
- The topic of animal ethics has advanced in tourism studies since its inception in 2000, based on a diverse range of studies on species involvement, types of uses and contexts, level of engagement, states of animals, and theoretical perspectives. While there is still considerable scope to amplify research on animal-based tourism, a gap exists in tourism pedagogy amidst the field’s emphasis on a new expanding consciousness platform. We review the depth of existing scholarship on animal ethics in tourism and develop an agenda for advancing animal ethics pedagogy for the future. Our intent is to issue a call to action for curriculum committees, programme administrators, and educators to recognise and act on this critical moral domain in tourism education.
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| 3. |
- Turrini, A. A., et al.
(författare)
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Tunable critical correlations in kagome ice
- 2022
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Ingår i: Physical Review B. - : American Physical Society (APS). - 2469-9950 .- 2469-9969. ; 105:9
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive experimental and theoretical study of the kagome ice Coulomb phase that explores the fine-tuning of critical correlations by applied field, temperature, and crystal orientation. The continuous modification of algebraic correlations is observed by polarized neutron scattering experiments and is found to be well described by numerical simulations of an idealized model. We further clarify the thermodynamics of field-tuned Kasteleyn transitions and demonstrate some dramatic finite-size-scaling properties that depend on how topological string defects wind around the system boundaries. We conclude that kagome ice is a remarkable example of a critical and topological state in a real system that may be subject to fine experimental control.
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| 4. |
- Matsui, H., et al.
(författare)
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A Multi-Instrument Study of a Dipolarization Event in the Inner Magnetosphere
- 2021
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 126:5
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Tidskriftsartikel (refereegranskat)abstract
- A dipolarization of the background magnetic field was observed during a conjunction of the Magnetospheric Multiscale (MMS) spacecraft and Van Allen Probe B on September 22, 2018. The spacecraft were located in the inner magnetosphere at L similar to 6-7 just before midnight magnetic local time (MLT). The radial separation between MMS and Probe B was similar to 1R(E). Gradual dipolarization or an increase of the northward component B-Z of the background field occurred on a timescale of minutes. Exploration of energization and Radiation in Geospace located 0.5 MLT eastward at a similar L shell also measured a gradual increase. The spatial scale was of the order of 1 R-E. On top of that, MMS and Probe B measured B-Z increases, and a decrease in one case, on a timescale of seconds, accompanied by large electric fields with amplitudes > several tens of mV/m. Spatial scale lengths were of the order of the ion inertial length and the ion gyroradius. The inertial term in the momentum equation and the Hall term in the generalized Ohm's law were sometimes non-negligible. These small-scale variations are discussed in terms of the ballooning/interchange instability and kinetic Alfven waves among others. It is inferred that physics of multiple scales was involved in the dynamics of this dipolarization event.
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