| 11. |
- Billnert, Robert, 1981, et al.
(författare)
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New information on the characteristics of 1 in. x 1 in. cerium bromide scintillation detectors
- 2011
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 647:1, s. 94-99
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Tidskriftsartikel (refereegranskat)abstract
- In view of highly demanded new and accurate data on prompt gamma-ray emission in nuclear fission a major part of investigations is directed towards the selection of suitable detector systems. Here we have studied a new type of crystal scintillation detectors made from cerium bromide (CeBr(3)). For the first time a full characterization of such a detector is presented in terms of energy resolution, pulse-height linearity, intrinsic activity and intrinsic timing resolution. In particular the latter one is very important for prompt fission gamma-ray studies, because the presence of fast neutrons, emitted in fission too, requires the time-of-flight method for their discrimination. The energy resolution has been found to be comparable to that of cerium-doped LaCl(3):Ce detectors at an efficiency comparable to the one of a LaBr(3):Ce detector of the same size. The intrinsic activity of the CeBr(3) crystal was observed to be much lower compared to lanthanum halide crystals. The intrinsic timing resolution of a coaxial 1 in. x 1 in. sized detector was measured relative to that of a previously characterized LaCl(3):Ce detector and found to be (326 +/- 7) Ps at (60)Co energies, which is in between those of a LaBr(3):Ce and a LaCl(3):Ce detector of same size.
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| 12. |
- Billnert, Robert, 1981, et al.
(författare)
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Novel Scintillation Detectors for Prompt Fission γ-Ray Measurements
- 2012
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Ingår i: Physics Procedia. - : Elsevier BV. - 1875-3884 .- 1875-3892. ; 31, s. 29-34
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Konferensbidrag (refereegranskat)abstract
- In this work we present first results from measurements of prompt fission γ-rays from the spontaneous fission in 252Cf. New and accurate data on corresponding γ-rays from the reactions 235U(nth,f) and 239Pu(nth,f) are highly demanded for the modeling of new Generation-IV nuclear reactor systems. For these experiments we employed scintillation detectors made out of new materials (LaBr3, LaCl3 and CeBr3), whose properties were necessary to know in order to obtain reliable results. Hence, we have characterized these detectors. In all the important properties these detectors outshine sodium-iodine detectors that where used in the 1970s, when the existing data had been acquired. Our finding is that the new generation of scintillation detectors is indeed promising, as far as an improved precision of the demanded data is concerned.
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| 13. |
- Claesson, Hans, et al.
(författare)
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Rheological behaviour during UV-curing of a star-branched polyester
- 2002
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Ingår i: Progress in organic coatings. - 0300-9440 .- 1873-331X. ; 44:1, s. 63-67
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Tidskriftsartikel (refereegranskat)abstract
- Using a rheometer coupled with an UV-light generator, the viscoelastic behaviour during the fast cure of star-branched polyester is investigated. The 32 arm star polymers consist of a hyperbranched polyester core, Boltorn(TM) and linear grafts of poly(E-caprolactone) (degree of polymerisation: 20-52) with methacrylate end groups. The resins are crystalline and the melting points range from 34 to 50degreesC; films can be formed and cured below 80degreesC. The crossover of G' and G was used as the gel point. The time to reach the gel point, a few seconds, increases linearly with molecular weight.
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| 14. |
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| 15. |
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| 16. |
- Edelbring, Samuel, 1969-, et al.
(författare)
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Experiencing virtual patients in clinical learning : a phenomenological study
- 2011
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Ingår i: Advances in Health Sciences Education. - : Springer. - 1382-4996 .- 1573-1677. ; 16:3, s. 331-345
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Tidskriftsartikel (refereegranskat)abstract
- Computerised virtual patients (VPs) are increasingly being used in medical education. With more use of this technology, there is a need to increase the knowledge of students experiences with VPs. The aim of the study was to elicit the nature of virtual patients in a clinical setting, taking the students experience as a point of departure. Thirty-one students used VPs as a mandatory part of an early clinical rotation in rheumatology. Using the qualitative approach of phenomenology, we interviewed these students and then analysed data regarding their experiences of VPs as a learning activity. The result shows that students perceived VP activities in relation to actual patients, the clinical context and other learning activities. The VPs represented typical clinical cases which encouraged clinical reasoning and allowed for decision making. The students experienced the activities as integrating biomedical knowledge and clinical experience, providing structure that prepared for the unstructured clinical environment and patient encounters under unstressful conditions. However, the VPs were experienced as lacking the emotional interactivity and complexity of actual patients. Theoretical frameworks of clinical reasoning and experiential learning are suggested as foundations for further educational integration of VPs in the clinical environment. VP activities during clinical rotations provide experiences of clinical reality and allow students to solve problems actively. These features are dependent on VP technology but are also contingent on the surrounding environment.
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| 17. |
- Edelbring, Samuel, 1969-, et al.
(författare)
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Virtual Patients in clinical education from a phenomenological perspective
- 2009
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Konferensbidrag (refereegranskat)abstract
- Background: Although Virtual Patients (VPs) are more commonly used today there is no clear-cut picture of the nature of VPs as a learning tool. This means that educators hesitate in further curricular integration of VPs. Students and educators need examples of how this innovation can support student learning in practice.Summary of work: We have analysed the use of VPs in a clinical rotation of medical students of rheumatology lasting 2-4 weeks. The phenomenological approach was used in order to maximise the student perspective. Focus lied with the character of VP learning and the immediate framework supporting meaningful learning with VPs at the clinic. We interviewed31 students followed by a phenomenological analysis of the transcriptions. This resulted inincreased knowledge of the value of VPs in this setting.Summary of results: VPs as a learning tool play a role of enhancing the value of other learning activities at the clinic. The immediate framework affects the way that students approach VPs. When students work in pairs, reflection and argumentation strengthen the learning experience.Conclusions: The study approach provided a way to characterise learning with VPs as enhancing the value of clinical education.Take-home messages: Phenomenological research interviews provide a way of discovering the value of innovations in medical education.
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| 18. |
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| 19. |
- Ekström, Lars, 1959, et al.
(författare)
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Intervertebral disc response to cyclic loading--an animal model.
- 1996
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Ingår i: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine. - 0954-4119. ; 210:4, s. 249-58
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Tidskriftsartikel (refereegranskat)abstract
- The viscoelastic response of a lumbar motion segment loaded in cyclic compression was studied in an in vivo porcine model (N = 7). Using surgical techniques, a miniaturized servohydraulic exciter was attached to the L2-L3 motion segment via pedicle fixation. A dynamic loading scheme was implemented, which consisted of one hour of sinusoidal vibration at 5 Hz, 50 N peak load, followed by one hour of restitution at zero load and one hour of sinusoidal vibration at 5 Hz, 100 N peak load. The force and displacement responses of the motion segment were sampled at 25 Hz. The experimental data were used for evaluating the parameters of two viscoelastic models: a standard linear solid model (three-parameter) and a linear Burger's fluid model (four-parameter). In this study, the creep behaviour under sinusoidal vibration at 5 Hz closely resembled the creep behaviour under static loading observed in previous studies. Expanding the three-parameter solid model into a four-parameter fluid model made it possible to separate out a progressive linear displacement term. This deformation was not fully recovered during restitution and is therefore an indication of a specific effect caused by the cyclic loading. High variability was observed in the parameters determined from the 50 N experimental data, particularly for the elastic modulus E1. However, at the 100 N load level, significant differences between the models were found. Both models accurately predicted the creep response under the first 800 s of 100 N loading, as displayed by mean absolute errors for the calculated deformation data from the experimental data of 1.26 and 0.97 percent for the solid and fluid models respectively. The linear Burger's fluid model, however, yielded superior predictions particularly for the initial elastic response.
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| 20. |
- Eland, John H. D., 1941, et al.
(författare)
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Double and Triple Ionisation of Isocyanic Acid
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Double and triple ionisation spectra of the reactive molecule isocyanic acid (HNCO) have been measured using multi-electron and ion coincidence techniques combined with synchrotron radiation and compared with high-level theoretical calculations. Vertical double ionisation at an energy of 32.8±0.3eV forms the 3A” ground state in which the HNCO2+ ion is long lived. The vertical triple ionisation energy is determined as 65±1eV. The core-valence double ionisation spectra resemble the valence photoelectron spectrum in form, and their main features can be understood on the basis of a simple and rather widely applicable Coulomb model based on the characteristics of the molecular orbitals from which electrons are removed. Characteristics of the most important dissociation channels are examined and discussed.
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