| 1. |
- Aas, AJ, et al.
(författare)
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Enhanced and quenched B(E1) transition rates between parity doublet bands in Ra-227
- 1996
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Ingår i: NUCLEAR PHYSICS A. - : ELSEVIER SCIENCE BV. - 0375-9474. ; 611:2-3, s. 281-314
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Tidskriftsartikel (refereegranskat)abstract
- The fast timing beta gamma gamma(t) method has been used to measure level lifetimes in the parity doublet bands in Ra-227 populated in the beta(-) decay of Fr-227. In particular, T-1/2 = 254(9) ps, 236(30) ps, less than or equal to 41 ps and 16(13) ps hav
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| 2. |
- Aas, AJ, et al.
(författare)
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Quenched E1 transition rates in Th-231
- 1999
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Ingår i: NUCLEAR PHYSICS A. - : ELSEVIER SCIENCE BV. - 0375-9474. ; 654:3-4, s. 499-522
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Tidskriftsartikel (refereegranskat)abstract
- The fast timing beta gamma gamma(t) method has been used to measure lifetimes of the low-lying levels in Th-231 populated in the beta(-) decay of Ac-231. The half-life of the K-pi = 5/2(-) band-head at 185.7-keV was measured as T-1/2 = 1073(79) ps, yieldi
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| 3. |
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| 4. |
- Gulda, K, et al.
(författare)
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Quadrupole deformed and octupole collective bands in Ra-228
- 1998
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Ingår i: NUCLEAR PHYSICS A. - : ELSEVIER SCIENCE BV. - 0375-9474. ; 636:1, s. 28-46
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Tidskriftsartikel (refereegranskat)abstract
- Spins and parities for collective states in Ra-228 have been determined from conversion electron measurements with a mini-orange beta spectrometer. The fast-timing beta gamma gamma(t) method has been used to measure lifetimes of T-1/2 = 550(20) ps and 181
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| 5. |
- Hoff, P, et al.
(författare)
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Single-neutron states in Sn-133
- 1996
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Ingår i: PHYSICAL REVIEW LETTERS. - : AMER INST PHYSICS. - 0031-9007. ; 77:6, s. 1020-1023
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Tidskriftsartikel (refereegranskat)abstract
- The location of several single-neutron states in Sn-133 has been identified. The P-3/2, h(9/2), and f(5/2) states were found at 853.7, 1560.9, and 2004.6 keV, respectively, by measuring gamma rays in coincidence with delayed neutrons following the decay o
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| 6. |
- Kurcewicz, W, et al.
(författare)
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The nuclear structure of Fr-227
- 1997
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Ingår i: NUCLEAR PHYSICS A. - : ELSEVIER SCIENCE BV. - 0375-9474. ; 621:4, s. 827-852
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Tidskriftsartikel (refereegranskat)abstract
- The gamma-rays following the beta(-) decay of Rn-227 have been investigated by means of gamma-ray singles and gamma gamma-coincidence measurements using an array of 12 Compton-suppressed Ge detectors. The fast-timing beta gamma gamma(t) method has been us
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| 7. |
- Lindroth, Axel
(författare)
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Octupole collectivity and E1 moments in neutron rich nuclei
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Spectroscopy of short-lived fission and reaction products has allowed a detailed structural study of neutron rich nuclei just above above 132Sn and 208Pb, respectively. The low-energy structures of 140Xe and 143Ba as well as a handful of neutron rich nuclei in the actinide region were examined. The excited levels were populated in β-decays of ISOL beams at the OSIRIS facility at Studsvik, and at the ISOLDE facility at CERN. At OSIRIS, a novel method for production of highly pure beams of iodine and bromium was implemented. Studies of the decays of these nuclei have until now been severely hampered by the strong isobaric contamination.The choice of nuclei to be studied was driven by the present lack of knowledge concerning octupole collectivity in general, and the associated electric dipole moments in particular. In order to be able to deduce correct electric dipole moments, the accurate βγγ(t) fast timing method was applied formeasurement of level half-lives in addition to the Multi Spectrum Scaling, γγ coincidence techniques and the measurement of internal conversion coefficients.In 140Xe predictions of a local quenching of the dipole moment were verified. Such quenching has been observed fortuitiously twice before, but never, as in the present case, in terms of a verification of theoretical calculations. The 3' state of this nucleus was found at a comparatively hi energy, indicating the rather sudden ending of the region of octupole collectivity above 132Sn. At 2457 keV a 5- state due to the coupling of an octupole phonon with a γ vibration was found. Previous evidence for the existence of such a state is scarce, or even inconclusive. The nearby nucleus 143Ba was also studied in detail. For the first time it was possible to rigorously assign positive parities to states in this nucleus, and the details of these states indicated an octupole deformed ground state. An enhanced dipole moment, typical for nuclei with octupole collectivity, was deduced from the measured level half-lives. However, comparison of β2 values from isotope shift measurements and from B(E2) values from the present study show a discrepancy which has to be explained in terms of enhancement of the values from the isotope shift measurements due to octupole deformation, Thus, the evidence is in conflict.Radium nuclei with mass 223,227 and 228, as well as 227Fr and 231Th were studied. For 227Fr a detailed decay-scheme, indicating the presence of octupole correltaions was established. Previously, no excited states were known. The results on 227Ra and 231Th showed that calculations with the quasi-particle plus phonon model can repdoduce the configuration mixing present. In addition, calculations based on a more rigid deformation failed to reproduce the absence of a major drop of E1 strength as deduced from the presently measured values in 228Ra.
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| 8. |
- Lindroth, Axel, et al.
(författare)
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Octupole vibration and influence of shell effects on the E1 transition rates in Xe-140
- 1999
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Ingår i: PHYSICAL REVIEW LETTERS. - : AMERICAN PHYSICAL SOC. - 0031-9007. ; 82:24, s. 4783-4786
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Tidskriftsartikel (refereegranskat)abstract
- Spectroscopic studies of the beta decay of I-140 have firmly established octupole collectivity in Xe-140 and evinced unique theoretical predictions of a quenched dipole moment. The first detailed investigations of an exotic Xe nucleus, including measureme
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| 9. |
- Lindroth, Malin, et al.
(författare)
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Marginaliserad sexualitet? Tvångsomhändertagna ungdomars attityder, erfarenheter och handlingar
- 2012
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Ingår i: Socionomens forskningssupplement. - : SSR. - 0283-1929. ; :31, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- Tvångsomhändertagna ungdomar är riskutsatta på många områden. Denna artikel fokuserar specifikt ungdomar på statliga ungdomshem. Vi redogör för hur ett urval av dessa unga har svarat i en enkätundersökning rörande sexuell hälsa samt hur deras svar på flera väsentliga punkter skiljer sig från övriga unga. Forskningsresultatet som är det första i sitt slag i Sverige stämmer väl överens med tidigare forskning som visar på samband mellan flera olika riskfaktorer eller riskbeteenden varav sexuellt risktagande är ett. Tillika ger det viktig kunskap att använda vid utformandet av en målgruppsanpassad modell för sex- och samlevnadsundervisning.
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| 10. |
- Lindroth, Tobias, et al.
(författare)
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Online Learning Models for Vehicle Usage Prediction During COVID-19
- 2024
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Ingår i: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050 .- 1558-0016. ; , s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Today, there is an ongoing transition to more sustainable transportation, for which an essential part is the switch from combustion engine vehicles to battery electric vehicles (BEVs). BEVs have many advantages from a sustainability perspective, but issues such as limited driving range and long recharge times slow down the transition from combustion engines. One way to mitigate these issues is by performing battery thermal preconditioning, which increases the energy efficiency of the battery. However, to optimally perform battery thermal preconditioning, the vehicle usage pattern needs to be known, i.e., how and when the vehicle will be used. This study attempts to predict the departure time and distance of the first drive each day using online machine learning models. The online machine learning models are trained and evaluated on historical driving data collected from a fleet of BEVs during the COVID-19 pandemic. Additionally, the prediction models are extended to quantify the uncertainty of their predictions, which can be used to decide whether the prediction should be used or dismissed. Based on our results, the best-performing prediction models yield an aggregated mean absolute error of 2.75 hours when predicting departure time and 13.37 km when predicting trip distance.
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