| 1. |
- Abele, H., et al.
(författare)
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Particle physics at the European Spallation Source
- 2023
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 1023, s. 1-84
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Forskningsöversikt (refereegranskat)abstract
- Presently under construction in Lund, Sweden, the European Spallation Source (ESS) will be the world’s brightest neutron source. As such, it has the potential for a particle physics program with a unique reach and which is complementary to that available at other facilities. This paper describes proposed particle physics activities for the ESS. These encompass the exploitation of both the neutrons and neutrinos produced at the ESS for high precision (sensitivity) measurements (searches).
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| 2. |
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| 3. |
- Aquila, Andrew, et al.
(författare)
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Time-resolved protein nanocrystallography using an X-ray free-electron laser
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:3, s. 2706-2716
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the use of an X-ray free electron laser synchronized with an optical pump laser to obtain X-ray diffraction snapshots from the photoactivated states of large membrane protein complexes in the form of nanocrystals flowing in a liquid jet. Light-induced changes of Photosystem I-Ferredoxin co-crystals were observed at time delays of 5 to 10 µs after excitation. The result correlates with the microsecond kinetics of electron transfer from Photosystem I to ferredoxin. The undocking process that follows the electron transfer leads to large rearrangements in the crystals that will terminally lead to the disintegration of the crystals. We describe the experimental setup and obtain the first time-resolved femtosecond serial X-ray crystallography results from an irreversible photo-chemical reaction at the Linac Coherent Light Source. This technique opens the door to time-resolved structural studies of reaction dynamics in biological systems.
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| 4. |
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| 5. |
- Bujosa Mateu, Daniel, et al.
(författare)
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The Effects of Clock Synchronization in TSN Networks with Legacy End-Stations
- 2022
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present our ongoing work on proposing solutions to integrate legacy end-stations into Time-Sensitive Network (TSN) communication systems where the legacy end-stations are synchronized via their legacy clock synchronization protocol. To this end, we experimentally identify the effects of lacking synchronization or partial synchronization in TSN networks. In the experiments we show the effects of clock synchronization in different scenarios on jitter and clock drifts. Based on the experiments, we propose preliminary solutions to overcome the identified effects.
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| 6. |
- Djärv, Tor, 1991, et al.
(författare)
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Bayesian predictions for A=6 nuclei using eigenvector continuation emulators
- 2022
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Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 105:1
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Tidskriftsartikel (refereegranskat)abstract
- We make ab initio predictions for the A=6 nuclear level scheme based on two- and three-nucleon interactions up to next-to-next-to-leading order in chiral effective field theory (χEFT). We utilize eigenvector continuation and Bayesian methods to quantify uncertainties stemming from the many-body method, the χEFT truncation, and the low-energy constants of the nuclear interaction. The construction and validation of emulators is made possible via the development of jupiterncsm - a new M-scheme no-core shell model code that uses on-the-fly Hamiltonian matrix construction for efficient, single-node computations up to Nmax=10 for Li6. We find a slight underbinding of He6 and Li6, although consistent with experimental data given our theoretical error bars. As a result of incorporating correlated χEFT-truncation errors we find more precise predictions (smaller error bars) for separation energies: Sd(Li6)=0.89±0.44MeV, S2n(He6)=0.20±0.60MeV, and for the beta decay Q value: Qβ-(He6)=3.71±0.65MeV. We conclude that our error bars can potentially be reduced further by extending the model space used by jupiterncsm.
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| 7. |
- Ekström, Andreas, 1980, et al.
(författare)
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Bayesian optimization in ab initio nuclear physics
- 2019
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Ingår i: Journal of Physics G-Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 46:9
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Tidskriftsartikel (refereegranskat)abstract
- Theoretical models of the strong nuclear interaction contain unknown coupling constants (parameters) that must be determined using a pool of calibration data. In cases where the models are complex, leading to time consuming calculations, it is particularly challenging to systematically search the corresponding parameter domain for the best fit to the data. In this paper, we explore the prospect of applying Bayesian optimization to constrain the coupling constants in chiral effective field theory descriptions of the nuclear interaction. We find that Bayesian optimization performs rather well with low-dimensional parameter domains and foresee that it can be particularly useful for optimization of a smaller set of coupling constants. A specific example could be the determination of leading three-nucleon forces using data from finite nuclei or three-nucleon scattering experiments.
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| 8. |
- Ekström, Maria, 1988, et al.
(författare)
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Towards phonon routing: controlling propagating acoustic waves in the quantum regime
- 2019
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 21:12
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Tidskriftsartikel (refereegranskat)abstract
- We explore routing of propagating phonons in analogy with previous experiments on photons. Surface acoustic waves (SAWs) in the microwave regime are scattered by a superconducting transmon qubit. The transmon can be tuned on or off resonance with the incident SAW field using an external magnetic field or the Autler-Townes effect, and thus the reflection and transmission of the SAW field can be controlled in time. We observe 80% extinction in the transmission of the low power continuous signal and a 40 ns rise time of the router. The slow propagation speed of SAWs on solid surfaces allows for in-flight manipulations of the propagating phonons. The ability to route short, 100 ns, pulses enables new functionality, for instance to catch an acoustic phonon between two qubits and then release it in a controlled direction.
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| 9. |
- Elfsberg, Jenny, 1973-, et al.
(författare)
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Guiding Global Innovation Teams on their Exploration Journey : Learning from Aspiring Engineering Students
- 2024
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Ingår i: International Journal of Engineering Education. - : Tempus Publications. - 0949-149X. ; 40:3, s. 472-490
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Tidskriftsartikel (refereegranskat)abstract
- This research investigates globally dispersed innovation teams involved in explorative projects within an engineering graduate course employing problem-based learning. Utilizing insights from a longitudinal study, the objective is to identify how to enhance both individual learning and team performance, thereby increasing the likelihood of a successful outcome. Initial observations revealed common patterns in learning experiences among the top-performing teams, prompting further investigation into how supporting cohorts might positively influence both team performance and students’ learning experiences throughout the course. In addition to advancing comprehension of innovation team performance, the study introduces two lightweight tools designed as shared visual representations of the team’s exploration journey. These tools can assist supporting cohorts in guiding teams effectively. This research augments the existing body of knowledge surrounding the achievement of breakthrough innovations. It provides understanding about how to facilitate team performance and individual learning within globally dispersed innovation teams undertaking explorative projects. The proposed lightweight tools offer practical solutions to enhance the supporting cohort’s ability to guide and impact team performance and individual learning experiences. This study holds implications for academia and industry, particularly organizations reliant on radical innovation for competitiveness and future-proving. Lastly, the study’s findings could inform the design and delivery of future problem-oriented, project-organized learning-based courses in engineering education.
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| 10. |
- Elfsberg, Jenny, 1973-, et al.
(författare)
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How Covid-19 Enabled a Global Student Design Team to Achieve Breakthrough Innovation
- 2021
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Ingår i: Proceedings of the Design Society 2021. - : Cambridge University Press. ; , s. 1705-1714
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Konferensbidrag (refereegranskat)abstract
- This is a qualitative single case study of a geographically distributed student team that experienced a quite different graduate course, compared to previous year's. This was due to the restrictions placed upon them following coronavirus lockdowns. With already ongoing research, and continuous development of the course, the authors had documented individual reflections and identified patterns and behaviours that seemingly determined the quality of the end result, as well as the students expectations and experiences. Semi-structured interviews, surveys and the author's individual reflection notes were already in place as part of the larger research scope and when the student team during the covid-19 year showed unexpected performance and results, the authors decided to pause the larger research scope and focus on this unique single case and capture those learnings. Not knowing how the Covid-19 situation evolves and leaning on insights from previous years, as well as this unique year, the aim with this paper is to describe the unique Covid-19 year amd share knowledge that can help improve and evolve the development of this longlived collaborative graduate student course, and other similar distributed team contexts.
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