1. |
- Caesar, C., et al.
(författare)
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Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26
- 2013
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813. ; 88:3
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Tidskriftsartikel (refereegranskat)abstract
- The very neutron-rich oxygen isotopes O-25 and O-26 are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from F-26 and F-27 at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into O-24 plus one or two neutrons, the O-25 ground-state energy and width are determined, and upper limits for the O-26 ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in O-26 at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.
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2. |
- Taghavi, Hamidreza, 1981, et al.
(författare)
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A vibration investigation of a flat surface contact to skull bone for direct bone conduction transmission in sheep skulls in vivo.
- 2013
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Ingår i: Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. - 1537-4505 .- 1531-7129. ; 34:4, s. 690-8
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis: Bone conduction implant (BCI) attached with a flat surface contact will offer efficient and linear vibration transmission over time. Background: Despite that percutaneous bone conduction devices (PBCD) are successful in treating patients with conductive hearing loss, there are some drawbacks related to the need of a permanent skin penetration. The BCI system is designed as an alternative to the PBCD because it leaves the skin intact. Methods: BCI dummy implants were installed in 3 sheep skulls in vivo to study the vibration transmission characteristics over time. Mechanical point impedances and vibration transfer response functions of the BCI implants were measured at the time of surgery and after a healing period of 8 months. Results: In 1 sheep both implants healed without complications. In the other 2 sheep, the implants were either partially loose or lost to follow up. In the sheep with stable implants, it was found by the resonance frequency shift of the mechanical point impedance that a firmer integration between the implant and bone tissue as seen in osseointegrated surfaces developed over time. It was also shown that the transcranial vibration transmission remains stable and linear. Providing bone chips in the contact between the implant and the bone did not enhance vibration transmission. The surgical procedure for installing the BCI dummy implants was uneventful. Conclusion: The mechanical point impedances and vibration transfer response functions indicate that the BCI implants integrate and that transmission conditions remain stable over time.
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3. |
- Altstadt, S.G., et al.
(författare)
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B-13,B-14(n,gamma) via Coulomb Dissociation for Nucleosynthesis towards the r-Process
- 2014
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Ingår i: Nuclear Data Sheets. - : Elsevier BV. - 1095-9904 .- 0090-3752. ; 120, s. 197-200
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Konferensbidrag (refereegranskat)abstract
- Radioactive beams of 14,15B produced by fragmentation of a primary 40Ar beam were directed onto a Pb target to investigate the neutron breakup within the Coulomb field. The experiment was performed at the LAND/R3B setup. Preliminary results for the Coulomb dissociation cross sections as well as for the astrophysically interesting inverse reactions, 13,14B(n,γ), are presented.
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4. |
- Aspeteg, Joakim, 1989, et al.
(författare)
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Intermediation services and adopter expectations and demands during the implementation of renewable electricity innovation – Match or mismatch?
- 2019
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 214, s. 837-847
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Tidskriftsartikel (refereegranskat)abstract
- To limit the irreversible consequences of global warming, it is crucial that new actors adopt renewable electricity technologies. This type of innovation is, however, complex to implement, which is the reason adopters often contract with intermediaries for support services, e.g., project developers or installers. Previous studies have underlined that it is difficult for intermediaries to provide services that fully satisfy different types of adopters. Contributing to the previous research on customer satisfaction of services and innovation intermediaries, this article identifies adopters’ expectations when adopting photovoltaic technology and analyzes whether such expectations match with the services provided by intermediaries. A cross-case analysis of photovoltaic projects was performed. Results underline that motives and driving forces for adopting the technology influences how adopters select intermediaries as well as what they expect from the services provided by intermediaries. The study finally contributes with some recommendations for intermediary organizations that want to improve and adapt their services to match their clients’ expectations and demands.
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5. |
- Boillos, J. M., et al.
(författare)
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Isotopic cross sections of fragmentation residues produced by light projectiles on carbon near
- 2022
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Ingår i: Physical Review C. - 2469-9993 .- 2469-9985. ; 105:1
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Tidskriftsartikel (refereegranskat)abstract
- We measured 135 cross sections of residual nuclei produced in fragmentation reactions of C12, N14, and O13−16,20,22 projectiles impinging on a carbon target at kinetic energies of near 400A MeV, most of them for the first time, with the RB3/LAND setup at the GSI facility in Darmstadt (Germany). The use of this state-of-the-art experimental setup in combination with the inverse kinematics technique gave the full identification in atomic and mass numbers of fragmentation residues with a high precision. The cross sections of these residues were determined with uncertainties below 20% for most of the cases. These data are compared to other previous measurements with stable isotopes and are also used to benchmark different model calculations.
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6. |
- Cedergren, Stefan, 1982, et al.
(författare)
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Influence of deformed surface layer when machining wrought alloy 718 in an annealed and in a pre-strained condition
- 2014
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Ingår i: 8th International Symposium on Superalloy 718 and Derivatives 2014; Pittsburgh; United States; 28 September 2014 through 1 October 2014. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 9781634396424 ; , s. 263-271
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Konferensbidrag (refereegranskat)abstract
- Superalloys are difficult to cut, mainly due to their preserved strength at elevated temperatures and their exceptional work hardening, where the latter results in a deformed layer on the machined surface. The thickness and degree of deformation of this layer depends on several parameters, such as cutting speed, uncut chip thickness, tool material and edge geometry. This layer enters the cutting zone of subsequent revolutions in turning or in milling. Under certain circumstances, as when the uncut chip thickness is small, all deformation at subsequent machining takes place within the deformed layer. The same phenomenon may occur at the outer edge of the cutting zone where the unrestricted material flow leads to burr formation. The deformed layer at the outer edge is suggested as the cause for notch wear often found when machining Superalloys. In this paper the effect of deformed layer on machining is examined through controlled experiments on the material in to different states of strain; in the annealed state without any remaining strain and with a substantial amount introduced by tensile straining. The results showed that cutting forces were reduced when pre-straining the material. Tool wear was similar in both materials, with large scatter due to built-up edge formation.
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7. |
- Hammarlund, Maria, et al.
(författare)
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The Alpha 7 Nicotinic Acetylcholine Receptor Does Not Affect Neonatal Brain Injury
- 2022
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Ingår i: Biomedicines. - : MDPI AG. - 2227-9059. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation plays a central role in the development of neonatal brain injury. The alpha 7 nicotinic acetylcholine receptor (alpha 7nAChR) can modulate inflammation and has shown promising results as a treatment target in rodent models of adult brain injury. However, little is known about the role of the alpha 7nAChR in neonatal brain injury. Hypoxic-ischemic (HI) brain injury was induced in male and female C57BL/6 mice, alpha 7nAChR knock-out (KO) mice and their littermate controls on postnatal day (PND) 9-10. C57BL/6 pups received i.p. injections of alpha 7nAChR agonist PHA 568487 (8 mg/kg) or saline once daily, with the first dose given directly after HI. Caspase-3 activity and cytokine mRNA expression in the brain was analyzed 24 h after HI. Motor function was assessed 24 and 48 h after HI, and immunohistochemistry was used to assess tissue loss at 24 h and 7 days after HI and microglial activation 7 days after HI. Activation of alpha 7nAChR with the agonist PHA 568487 significantly decreased CCL2/MCP-1, CCL5/RANTES and IL-6 gene expression in the injured brain hemisphere 24 h after HI compared with saline controls in male, but not female, pups. However, alpha 7nAChR activation did not alter caspase-3 activity and TNF alpha, IL-1 beta and CD68 mRNA expression. Furthermore, agonist treatment did not affect motor function (24 or 48 h), neuronal tissue loss (24 h or 7 days) or microglia activation (7 days) after HI in either sex. Knock-out of alpha 7nAChR did not influence neuronal tissue loss 7 days after HI. In conclusion, targeting the alpha 7nAChR in neonatal brain injury shows some effect on dampening acute inflammatory responses in male pups. However, this does not lead to an effect on overall injury outcome.
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8. |
- Holl, M., et al.
(författare)
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Quasi-free neutron and proton knockout reactions from light nuclei in a wide neutron-to-proton asymmetry range
- 2019
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 795, s. 682-688
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Tidskriftsartikel (refereegranskat)abstract
- The quasi-free scattering reactions 11C(p,2p) and 10,11,12C(p,pn) have been studied in inverse kinematics at beam energies of 300–400 MeV/u at the R3B-LAND setup. The outgoing proton-proton and proton-neutron pairs were detected in coincidence with the reaction fragments in kinematically complete measurements. The efficiency to detect these pairs has been obtained from GEANT4 simulations which were tested using the 12C(p,2p) and 12C(p,pn) reactions. Experimental cross sections and momentum distributions have been obtained and compared to DWIA calculations based on eikonal theory. The new results reported here are combined with previously published cross sections for quasi-free scattering from oxygen and nitrogen isotopes and together they enable a systematic study of the reduction of single-particle strength compared to predictions of the shell model over a wide neutron-to-proton asymmetry range. The combined reduction factors show a weak or no dependence on isospin asymmetry, in contrast to the strong dependency reported in nucleon-removal reactions induced by nuclear targets at lower energies. However, the reduction factors for (p,2p) are found to be 'significantly smaller than for (p,pn) reactions for all investigated nuclei.
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9. |
- Johansson, Fredrik, 1983-, et al.
(författare)
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Cykeltrafikmodellering : behovsanalys och kunskapsläge
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trafikmodeller för cykeltrafik saknas till stor del vilket försvårar planering av effektiv, säker och attraktiv cykelinfrastruktur. Syftet med denna förstudie är att identifiera forsknings- och utvecklings-behov i Sverige inom området cykeltrafikmodellering, för att på så sätt vägleda framtida satsningar inom området. Förstudien har genomförts i två etapper: behovsanalys och sammanställning av kunskapsläge och forskningsbehov kring mikroskopiska och makroskopiska trafikmodeller. För att undersöka behov av modellstöd samt identifiera forsknings- och utvecklingsbehov i Sverige genomfördes dels intervjuer med konsulter verksamma inom området, dels en workshop med representanter från kommuner, regioner och Trafikverket. För att sammanställa kunskapsläget kring cykeltrafikmodeller har en litteraturstudie genomförts. Behovsanalysen i kombination med sammanställningen av kunskapsläget visar på att det finns ett tydligt behov av fortsatt forsknings- och utvecklingsarbete av makroskopiska och mikroskopiska cykeltrafikmodeller. Centralt för utveckling och tillämpning av båda modelltyperna är tillgången till data. För makroskopiska trafikmodeller finns ett långsiktigt behov av utveckling av efterfrågemodeller som inkluderar cyklister samt av ruttvals-modeller. När det gäller mikroskopiska cykeltrafikmodeller bör den långsiktiga utvecklingen inriktas mot vidareutveckling av antingen bilinspirerade eller kraftinspirerade modeller, alternativ nya modellansatser om så behövs.
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10. |
- Johansson, Joakim, 1983, et al.
(författare)
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Effect of microstructure on dynamic shear localisation in Alloy 718
- 2017
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Ingår i: Mechanics of Materials. - : Elsevier BV. - 0167-6636. ; 109, s. 88-100
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Tidskriftsartikel (refereegranskat)abstract
- The effect of microstructure on the strain localisation behaviour during dynamic shear deformation of Ni-Fe-base superalloy Alloy 718 was investigated by a combination of experiments and numerical simulations of Split-Hopkinson tests of specimens with top-hat geometry. The results show that strain localisation is promoted by small grain size and precipitation hardening, whereas large grains and solution annealing largely supressed the formation of shear bands. In addition, a smaller fillet radius facilitated the initiation of shear bands. Finite element simulations were able to reproduce the most important features of both global load–displacement histories, and presence of shear localisation. In particular, detailed simulations of the local deformation during localisation showed that temperatures exceeding 750?°C (locally above 1000?°C) and strain rates in the order of 2?105 s?1 were reached in the band.
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