| 1. |
- Zhirkov, Igor, et al.
(författare)
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Effect of cathode composition and nitrogen pressure on macroparticle generation and type of arc discharge in a DC arc source with Ti-Al compound cathodes
- 2015
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Ingår i: Surface & Coatings Technology. - : ELSEVIER SCIENCE SA. - 0257-8972 .- 1879-3347. ; 281, s. 20-26
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Tidskriftsartikel (refereegranskat)abstract
- Thin films deposited with unfiltered DC arc plasma from Ti, Ti0.75Al0.25, Ti0.50Al0.50, Ti0.30Al0.70, and Al cathodes were characterized with a scanning electron microscope for quantification of extent of macroparticle incorporation. Depositions were performed in N-2 atmosphere in the pressure range from 10(-6) Torr up to 3 . 10(-2) Torr, and the formation of cathode surface nitride contamination was identified from X-ray diffraction analysis. Visual observation and photographic fixation of the arc spot behavior was simultaneously performed. A reduction in macroparticle generation with decreasing Al content and increasing N-2 pressure was demonstrated. A correlated transformation of the arc from type 2 to the type 1 was visually detected and found to be a function of N-2 pressure and at of Al in the cathode. For the Ti cathode, no arc transformation was detected. These observations can be explained by a comparatively high electrical resistivity and high melting point of Al rich surface nitrides, promoting an arc transformation and a reduction in macropartide generation. (C) 2015 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Bayadsi, Haytham, 1987-, et al.
(författare)
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The correlation between small papillary thyroid cancers and gamma radionuclides Cs-137, Th-232, U-238 and K-40 using spatially-explicit, register-based methods
- 2023
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Ingår i: Spatial and Spatio-Temporal Epidemiology. - : Elsevier. - 1877-5845 .- 1877-5853. ; 47
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Tidskriftsartikel (refereegranskat)abstract
- A steep increase of small papillary thyroid cancers (sPTCs) has been observed globally. A major risk factor for developing PTC is ionizing radiation. The aim of this study is to investigate the spatial distribution of sPTC in Sweden and the extent to which prevalence is correlated to gamma radiation levels (Caesium-137 (Cs-137), Thorium-232 (Th-232), Uranium-238 (U-238) and Potassium-40 (K-40)) using multiple geospatial and geo-statistical methods. The prevalence of metastatic sPTC was associated with significantly higher levels of Gamma radiation from Th-232, U-238 and K-40. The association is, however, inconsistent and the prevalence is higher in densely populated areas. The results clearly indicate that sPTC has causative factors that are neither evenly distributed among the population, nor geographically, calling for further studies with bigger cohorts. Environ-mental factors are believed to play a major role in the pathogenesis of the disease.
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| 4. |
- Jia, Donglin, et al.
(författare)
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Highly Stabilized Quantum Dot Ink for Efficient Infrared Light Absorbing Solar Cells
- 2019
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Ingår i: Advanced Energy Materials. - : WILEY-V C H VERLAG GMBH. - 1614-6832 .- 1614-6840. ; 9:44
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Tidskriftsartikel (refereegranskat)abstract
- Liquid-state ligand exchange provides an efficient approach to passivate a quantum dot (QD) surface with small binding species and achieve a QD ink toward scalable QD solar cell (QDSC) production. Herein, experimental studies and theoretical simulations are combined to establish the physical principles of QD surface properties induced charge carrier recombination and collection in QDSCs. Ammonium iodide (AI) is used to thoroughly replace the native oleic acid ligand on the PbS QD surface forming a concentrated QD ink, which has high stability of more than 30 d. The ink can be directly applied for the preparation of a thick QD solid film using a single deposition step method and the QD solid film shows better characteristics compared with that of the film prepared with the traditional PbX2 (X = I or Br) post-treated QD ink. Infrared light-absorbing QDSC devices are fabricated using the PbS-AI QD ink and the devices give a higher photovoltaic performance compared with the devices fabricated with the traditional PbS-PbX2 QD ink. The improved photovoltaic performance in PbS-AI-based QDSC is attributed to diminished charge carrier recombination induced by the sub-bandgap traps in QDs. A theoretical simulation is carried out to atomically link the relationship of QDSC device function with the QD surface properties.
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| 5. |
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| 6. |
- Itayem, Raed, 1967, et al.
(författare)
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Influence of implant variations on survival of the Lubinus SP II stem: evaluation of 76,530 hips in the Swedish Arthroplasty Register, 2000-2018.
- 2022
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Ingår i: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 93, s. 37-42
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose - Almost all prosthetic implant brands include several variations. Most studies on implant performance investigate an implant system without sub-analysis of implant attributes. We studied the influence of design variations during the last 2 decades on implant survival of the most frequently used cemented femoral stem, the Lubinus SPII, reported to the Swedish Arthroplasty Register (SHAR). Patients and methods - Between 2000 and 2018, 100,032 cemented Lubinus SP II stems had been reported to SHAR. Patients with primary osteoarthritis operated on with stem length 150 mm together with a cemented cup from the same manufacturer (n = 76,530) were included in this analysis. Primary study outcome was non-infectious stem revision. Cox regression with adjustment for age, sex, surgical approach, and year of surgery was used. Hazard rates (HR) are presented with 95% confidence intervals (CI). Results - Average follow-up was 7.6 years (SD 4.2). At 18 years the overall stem survival was 99.1 (CI 98.9-99.3). Increased revision rate was observed for stems with extra offset, when a long or an extra-long head length had been used. Smaller stem sizes, in particular the smallest stem size (01), substantially increased the rate of mechanical failure as reflected by an almost 10 times increased rate of revision compared with the standard size (2). Interpretation - In this study with larger sample size and longer follow-up than previously presented from the same register, we observed more pronounced effects of previously documented design variations. Based on our results, surgeons using the Lubinus SPII stems are advised to consider an alternative solution if a Lubinus stem size 01, Lubinus extra offset, or an extra-long head seems to be the most suitable choice at the preoperative planning.
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| 7. |
- Ivanov, Alexander G, et al.
(författare)
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Digalactosyl-diacylglycerol deficiency impairs the capacity for photosynthetic intersystem electron transport and state transitions in Arabidopsis thaliana due to photosystem I acceptor-side limitations.
- 2006
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Ingår i: Plant Cell Physiology. - : Oxford University Press (OUP). - 0032-0781 .- 1471-9053. ; 47:8, s. 1146-57
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Tidskriftsartikel (refereegranskat)abstract
- Compared with wild type, the dgd1 mutant of Arabidopsis thaliana exhibited a lower amount of PSI-related Chl–protein complexes and lower abundance of the PSI-associated polypeptides, PsaA, PsaB, PsaC, PsaL and PsaH, with no changes in the levels of Lhca1–4. Functionally, the dgd1 mutant exhibited a significantly lower light-dependent, steady-state oxidation level of P700 (P700+) in vivo, a higher intersystem electron pool size, restricted linear electron transport and a higher rate of reduction of P700+ in the dark, indicating an increased capacity for PSI cyclic electron transfer compared with the wild type. Concomitantly, the dgd1 mutant exhibited a higher sensitivity to and incomplete recovery of photoinhibition of PSI. Furthermore, dgd1 exhibited a lower capacity to undergo state transitions compared with the wild type, which was associated with a higher reduction state of the plastoquinone (PQ) pool. We conclude that digalactosyl-diacylglycerol (DGDG) deficiency results in PSI acceptor-side limitations that alter the flux of electrons through the photosynthetic electron chain and impair the regulation of distribution of excitation energy between the photosystems. These results are discussed in terms of thylakoid membrane domain reorganization in response to DGDG deficiency in A. thaliana.
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| 8. |
- Molisch, Andreas
(författare)
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A generic model for MIMO wireless propagation channels
- 2002
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Ingår i: IEEE International Conference on Communications, 2002. ICC 2002.. - 0780374002 ; 1, s. 277-282
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Konferensbidrag (refereegranskat)abstract
- We study the MIMO wireless channel, and derive a generic channel model that we believe has the ability to explain all important effects, including (i) interdependency of directions-of-arrival and directions-of-departure, (ii) large delay and angle dispersion by propagation via far clusters, (iii) rank reduction of the transfer function matrix. We point out the relevant propagation effects, and propose a geometry-based model that includes the relevant effects. The required parameters for the complete definition of the model are enumerated, and typical simulation results for urban macrocells are presented
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| 9. |
- Barker, Dean, 1977, et al.
(författare)
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Learning through group work in physical education: a symbolic interactionist approach
- 2015
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Ingår i: Sport Education and Society. - : Informa UK Limited. - 1357-3322 .- 1470-1243. ; 20:5, s. 604-623
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Tidskriftsartikel (refereegranskat)abstract
- In line with contemporary constructivist pedagogies, students are frequently expected to learn through interaction in physical education (PE). There is a relatively sophisticated body of literature focusing on learning in groups, peer teaching, and cooperative learning. Current research has not, however, focused on how the body is implicated in interactional learning. This is surprising given that much learning in PE is expected to take place in the physical domain. The aim of this paper is to contribute to current theorizing by examining social interactions in PE practice. By drawing on symbolic interactionist theory, we put forward a framework for considering how inter-student interactions occur in a multimodal sense. Key ideas relate to (1) the sequential organization of interactions; (2) the ways in which semiotic resources in different fields are used to elaborate each other; (3) the importance of interpretation as a driver of interaction; (4) the creation of local environments in which participants attend to and work together within a shared world of perception; and (5) the influence of material environments on social interaction. The specific concepts employed are epistemic ecology, epistemic position, and learning trajectory. The paper includes observational data from an investigation of learning in Swedish PE to demonstrate the explanatory power and limitations of the theoretical tenets presented. The paper is concluded with practical implications of understanding group work in a multimodal manner.
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