| 1. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Edberg, Niklas J. T., et al.
(författare)
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Spatial distribution of low-energy plasma around comet 67P/CG from Rosetta measurements
- 2015
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 42:11, s. 4263-4269
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Tidskriftsartikel (refereegranskat)abstract
- We use measurements from the Rosetta plasma consortium Langmuir probe and mutual impedance probe to study the spatial distribution of low-energy plasma in the near-nucleus coma of comet 67P/Churyumov-Gerasimenko. The spatial distribution is highly structured with the highest density in the summer hemisphere and above the region connecting the two main lobes of the comet, i.e., the neck region. There is a clear correlation with the neutral density and the plasma to neutral density ratio is found to be approximate to 1-210(-6), at a cometocentric distance of 10km and at 3.1AU from the Sun. A clear 6.2h modulation of the plasma is seen as the neck is exposed twice per rotation. The electron density of the collisionless plasma within 260km from the nucleus falls off with radial distance as approximate to 1/r. The spatial structure indicates that local ionization of neutral gas is the dominant source of low-energy plasma around the comet.
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| 3. |
- Eriksson, Anders I., et al.
(författare)
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Cold and warm electrons at comet 67P/Churyumov-Gerasimenko
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 605
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Tidskriftsartikel (refereegranskat)abstract
- Context. Strong electron cooling on the neutral gas in cometary comae has been predicted for a long time, but actual measurements of low electron temperature are scarce. Aims. Our aim is to demonstrate the existence of cold electrons in the inner coma of comet 67P/Churyumov-Gerasimenko and show filamentation of this plasma. Methods. In situ measurements of plasma density, electron temperature and spacecraft potential were carried out by the Rosetta Langmuir probe instrument, LAP. We also performed analytical modelling of the expanding two-temperature electron gas. Results. LAP data acquired within a few hundred km from the nucleus are dominated by a warm component with electron temperature typically 5-10 eV at all heliocentric distances covered (1.25 to 3.83 AU). A cold component, with temperature no higher than about 0.1 eV, appears in the data as short (few to few tens of seconds) pulses of high probe current, indicating local enhancement of plasma density as well as a decrease in electron temperature. These pulses first appeared around 3 AU and were seen for longer periods close to perihelion. The general pattern of pulse appearance follows that of neutral gas and plasma density. We have not identified any periods with only cold electrons present. The electron flux to Rosetta was always dominated by higher energies, driving the spacecraft potential to order -10 V. Conclusions. The warm (5-10 eV) electron population observed throughout the mission is interpreted as electrons retaining the energy they obtained when released in the ionisation process. The sometimes observed cold populations with electron temperatures below 0.1 eV verify collisional cooling in the coma. The cold electrons were only observed together with the warm population. The general appearance of the cold population appears to be consistent with a Haser-like model, implicitly supporting also the coupling of ions to the neutral gas. The expanding cold plasma is unstable, forming filaments that we observe as pulses.
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| 4. |
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| 5. |
- Århammar, Cecilia, et al.
(författare)
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Unveiling the complex electronic structure of amorphous metal oxides
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:16, s. 6355-6360
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Tidskriftsartikel (refereegranskat)abstract
- Amorphous materials represent a large and important emerging area of material's science. Amorphous oxides are key technological oxides in applications such as a gate dielectric in Complementary metal-oxide semiconductor devices and in Silicon-Oxide-Nitride-Oxide-Silicon and TANOS (TaN-Al2O3-Si3N4-SiO2-Silicon) flash memories. These technologies are required for the high packing density of today's integrated circuits. Therefore the investigation of defect states in these structures is crucial. In this work we present X-ray synchrotron measurements, with an energy resolution which is about 5-10 times higher than is attainable with standard spectrometers, of amorphous alumina. We demonstrate that our experimental results are in agreement with calculated spectra of amorphous alumina which we have generated by stochastic quenching. This first principles method, which we have recently developed, is found to be superior to molecular dynamics in simulating the rapid gas to solid transition that takes place as this material is deposited for thin film applications. We detect and analyze in detail states in the band gap that originate from oxygen pairs. Similar states were previously found in amorphous alumina by other spectroscopic methods and were assigned to oxygen vacancies claimed to act mutually as electron and hole traps. The oxygen pairs which we probe in this work act as hole traps only and will influence the information retention in electronic devices. In amorphous silica oxygen pairs have already been found, thus they may be a feature which is characteristic also of other amorphous metal oxides.
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| 6. |
- Ericsson, Stefan, et al.
(författare)
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Towards automatic detection of local bearing defects in rotating machines
- 2005
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Ingår i: Mechanical systems and signal processing. - : Elsevier BV. - 0888-3270 .- 1096-1216. ; 19:3, s. 509-535
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we derive and compare several different vibration analysis techniques for automatic detection of local defects in bearings. Based on a signal model and a discussion on to what extent a good bearing monitoring method should trust it, we present several analysis tools for bearing condition monitoring and conclude that wavelets are especially well suited for this task. Then we describe a large-scale evaluation of several different automatic bearing monitoring methods using 103 laboratory and industrial environment test signals for which the true condition of the bearing is known from visual inspection. We describe the four best performing methods in detail (two wavelet-based, and two based on envelope and periodisation techniques). In our basic implementation, without using historical data or adapting the methods to (roughly) known machine or signal parameters, the four best methods had 9-13% error rate and are all good candidates for further fine-tuning and optimisation. Especially for the wavelet-based methods, there are several potentially performance improving additions, which we finally summarise into a guiding list of suggestion.
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| 7. |
- Esmaily, Mohsen, 1987, et al.
(författare)
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The influence of SO2 on the corrosion of Mg and Mg-Al alloys
- 2015
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 162:6, s. C260-C269
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Tidskriftsartikel (refereegranskat)abstract
- The SO2-induced atmospheric corrosion of some magnesium-aluminum (Mg-Al) alloys, including Mg alloy AZ91D, and commercially pure Mg (CP Mg) was investigated using well-controlled laboratory exposures and included real-time measurements of SO2 deposition. The influence of SO2 concentration, alloy composition, humidity, and ppb level additions of O-3 or NO2 on the rate of SO2 deposition was investigated. SO2 accelerates the corrosion of Mg and Mg alloys causing localized corrosion, MgSO(3)6H(2)O being the dominant corrosion product. At 60% RH, traces of O-3 or NO2 strongly increased both the SO2 deposition and the corrosion rate. The rate of SO2 deposition was strongly dependent on humidity; at 70% RH and higher the SO2 deposition rate was very rapid and constant in time while it was transient below 50% RH. At 60% RH, a change from transient to rapid, steady-state, SO2 deposition occurred. The sudden activation is explained by the onset of electrochemical corrosion. The activation behavior was shown to depend on SO2 concentration, the thickness of the surface film and by the presence of ambient O-2. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.
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| 8. |
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| 9. |
- Johansson, Camilla, et al.
(författare)
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Identification of Gene-Therapy Responsive Blood Biomarkers for Duchenne Muscular Dystrophy
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionAssessing muscle dystrophin expression systemically is important for understanding the effect of dystrophin-restoring therapies in Duchenne muscular dystrophy (DMD). Many potential blood biomarkers have been identified in DMD patients which are either more or less abundant in blood samples compared to healthy individuals and that have been shown to change with disease progression or respond to pharmacological treatment. In this study, it was suggested that a panel of such blood biomarker candidates could be used to monitor dystrophin rescue in microdystrophin therapies. MethodsPlasma samples from mdx mice treated with the microdystrophin therapy SGT-001 were analysed with an antibody suspension bead array consisting of 87 antibodies targeting 83 proteins previously identified as biomarker candidates for DMD. Each sample was assayed at two different plasma dilutions to cover a broader concentration range. Median fluorescent intensities (MFI) for each antibody were correlated to dystrophin expression in muscle tissue, as measured by immunohistochemistry and Western blot. 13 targets were selected and validated in a DMD and Becker muscular dystrophy (BMD) longitudinal natural history cohort using a suspension bead array. Results10 proteins were found significantly elevated in untreated mdx mice compared to C57 wild-type mice and 10 were found to correlate with dystrophin expression (Spearman’s correlation, FDR < 0.05) upon gene transfer. Abundance of TTN, ADSSL1, LONP1, OTUD5, MYL3 as well as DMD protein were associated with dystrophin expression in BMD patients. Of these, MYL3 and ADSSL1 had different abundance in DMD compared to healthy individuals, and MYL3 also displayed different age trajectories between DMD and BMD patients. DiscussionThe ten proteins identified in mouse plasma are related to muscle contraction (ADSSL1, ASAH1, CA3, MYL3, TTN), microtubule formation (TPI1), and protein degradation (PSMA2, OTUD4, LONP1). Of these, MYL3 and ADSSL1 showed the most promise as a dystrophin monitoring biomarker in patient samples.
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| 10. |
- Johansson, Camilla, et al.
(författare)
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Monitoring Biomarker Study in Becker Muscular Dystrophy using Data Independent Acquisition LC-MS/MS
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Becker muscular dystrophy (BMD) is a rare and heterogenous form of dystrophinopathy caused by reduced expression of altered dystrophin protein. Gene therapies and exon-skipping therapies for the more severe form of dystrophinopathy, Duchenne muscular dystrophy (DMD), assumes that by promoting partial dystrophin expression in DMD patients, their disease progression could be reduced. Several studies have identified potential progression biomarkers for DMD and hypothesised in their usefulness in monitoring pharmacodynamic response in gene-therapy clinical trials. However, knowledge of progression changes of blood proteome in BMD is lacking. In this study, we aimed at exploring differences in proteomic changes between DMD and BMD in a prospective longitudinal 4-year study as well as explore what proteins relate to functional performance in BMD patients. Serum from 48 BMD patients and 19 DMD patients were analysed using Data Independent Acquisition Tandem Mass Spectrometry (DIA-MS). Linear mixed effects models identified 17 proteins with altered longitudinal signatures between DMD and BMD, among these CKM, PKM and ALDOA. Furthermore, bikunin (product of AMBP gene), C3 and IGHG2 were found related to functional performance in BMD patients.
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