| 1. |
- Joffrin, E., et al.
(author)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Research review (peer-reviewed)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 2. |
- Sandin, Per, et al.
(author)
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Precautionary defaults - A new strategy for chemical risk management
- 2004
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In: Human and Ecological Risk Assessment. - : Informa UK Limited. - 1080-7039 .- 1549-7860. ; 10, s. 1-18
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Journal article (peer-reviewed)abstract
- In order to give adequate support to risk managers, new risk assessment methods should be developed that are (1) scientifically sound, (2) simplified, and (3) suited for precautionary risk management. In this Perspective we propose that the notion of a precautionary default can be a useful tool in the development of such methods. A precautionary default is a cautious or pessimistic assumption that is used in the absence of adequate information and that should be replaced when such information is obtained. Furthermore, we point out some promising research areas for the development of such indicators, viz. connections between chemical characteristics such as persistence and effect parameters, monitoring of contaminants in polar regions, monitoring of contaminants in breast milk, application of results from (human) toxicology in ecotoxicology and vice versa, (eco) toxicological test systems that are sensitive to effects on reproduction, and the application of bioinformatic methods to complex data, both in genomic research and in ecotoxicology. We conclude that precautionary decision-making does not require less science, but to the contrary it requires more science and improved communication between scientists and risk managers.
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| 3. |
- Brechmann, Nils Arnold, et al.
(author)
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Pilot-scale process for magnetic bead purification of antibodies directly from non-clarified CHO cell culture
- 2019
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In: Biotechnology progress (Print). - : AIChE. - 8756-7938 .- 1520-6033.
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Journal article (peer-reviewed)abstract
- High capacity magnetic protein A agarose beads, LOABeads PrtA, were used in the developmentof a new process for affinity purification of monoclonal antibodies (mAbs) from non-clarifiedCHO cell broth using a pilot-scale magnetic separator. The LOABeads had a maximum bindingcapacity of 65 mg/mL and an adsorption capacity of 25–42 mg IgG/mL bead in suspension for anIgG concentration of 1 to 8 g/L. Pilot-scale separation was initially tested in a mAb capture stepfrom 26 L clarified harvest. Small-scale experiments showed that similar mAb adsorptions wereobtained in cell broth containing 40 Å~ 106 cells/mL as in clarified supernatant. Two pilot-scalepurification runs were then performed on non-clarified cell broth from fed-batch runs of 16 L,where a rapid mAb adsorption ≥96.6% was observed after 1 h. This process using 1 L of magnetic beads had an overall mAb yield of 86% and 16 times concentration factor. After this single proteinA capture step, the mAb purity was similar to the one obtained by column chromatography, whilethe host cell protein content was very low, <10 ppm. Our results showed that this magnetic beadmAb purification process, using a dedicated pilot-scale separation device, was a highly efficientsingle step, which directly connected the culture to the downstream process without cell clarification.Purification of mAb directly from non-clarified cell broth without cell separation can providesignificant savings in terms of resources, operation time, and equipment, compared to legacy procedure of cell separation followed by column chromatography step.
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| 4. |
- Eriksson, Bjorn, et al.
(author)
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Limited value of NT-proBNP as a prognostic marker of all-cause mortality in patients with heart failure with preserved and mid-range ejection fraction in primary care : A report from the swedish heart failure register
- 2019
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In: Scandinavian Journal of Primary Health Care. - : TAYLOR & FRANCIS LTD. - 0281-3432 .- 1502-7724. ; 37:4, s. 434-443
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Journal article (peer-reviewed)abstract
- Aim: The prognostic value of natriuretic peptides in the management of heart failure (HF) patients with ejection fraction (EF) <40% is well established, but is less known for those with EF >= 40% managed in primary care (PC). Therefore, the aim of this study is to describe the prognostic significance of plasma NT-proBNP in such patients managed in PC. Subjects: We included 924 HF patients (48% women) with EF >= 40% and NT-proBNP registered in the Swedish Heart Failure Registry. Follow-up was 1100 +/- 687 days. Results: One-, three- and five-year mortality rates were 8.1%, 23.9% and 44.7% in patients with EF 40-50% (HFmrEF) and 7.3%, 23.6% and 37.2% in patients with EF >= 50% (HFpEF) (p = 0.26). Patients with the highest mean values of NT-proBNP had the highest all-cause mortality but wide standard deviations (SDs). In univariate regression analysis, there was an association only between NT-proBNP quartiles and all-cause mortality. In HFmrEF patients, hazard ratio (HR) was 1.96 (95% CI 1.60-2.39) p < 0.0001) and in HFpEF patients, HR was 1.72 (95% CI 1.49-1.98) p < 0.0001). In a multivariate Cox proportional hazard regression analysis, adjusted for age, NYHA class, atrial fibrillation and GFR class, this association remained regarding NT-proBNP quartiles [HR 1.83 (95% CI 1.38-2.44), p < 0.0001] and [HR 1.48 (95% CI 1.16-1.90), p = 0.0001], HFmrEF and HFpEF, respectively. Conclusion: NT-proBNP has a prognostic value in patients with HF and EF >= 40% managed in PC. However, its clinical utility is limited due to high SDs and the fact that it is not independent in this population which is characterized by high age and much comorbidity.
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| 5. |
- Eriksson, Frida, 1986, et al.
(author)
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Impact of fast ions on density peaking in JET : fluid and gyrokinetic modeling
- 2019
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In: Plasma Physics and Controlled Fusion. - : Institute of Physics Publishing (IOPP). - 0741-3335 .- 1361-6587. ; 61:7
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Journal article (peer-reviewed)abstract
- The effect of fast ions on turbulent particle transport, driven by ion temperature gradient (ITG)/trapped electron mode turbulence, is studied. Two neutral beam injection (NBI) heated JET discharges in different regimes are analyzed at the radial position rho(t) = 0.6, one of them an L-mode and the other one an H-mode discharge. Results obtained from the computationally efficient fluid model EDWM and the gyro-fluid model TGLF are compared to linear and nonlinear gyrokinetic GENE simulations as well as the experimentally obtained density peaking. In these models, the fast ions are treated as a dynamic species with a Maxwellian background distribution. The dependence of the zero particle flux density gradient (peaking factor) on fast ion density, temperature and corresponding gradients, is investigated. The simulations show that the inclusion of a fast ion species has a stabilizing influence on the ITG mode and reduces the peaking of the main ion and electron density profiles in the absence of sources. The models mostly reproduce the experimentally obtained density peaking for the L-mode discharge whereas the H-mode density peaking is significantly underpredicted, indicating the importance of the NBI particle source for the H-mode density profile.
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| 6. |
- Eriksson, Frida, 1986, et al.
(author)
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Interpretative and predictive modelling of Joint European Torus collisionality scans
- 2019
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In: Plasma Physics and Controlled Fusion. - : Institute of Physics Publishing (IOPP). - 0741-3335 .- 1361-6587. ; 61:11
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Journal article (peer-reviewed)abstract
- Transport modelling of Joint European Torus (JET) dimensionless collisionality scaling experiments in various operational scenarios is presented. Interpretative simulations at a fixed radial position are combined with predictive JETTO simulations of temperatures and densities, using the TGLF transport model. The model includes electromagnetic effects and collisions as well as (E)over-right-arrow x (b)over-right-arrow shear in Miller geometry. Focus is on particle transport and the role of the neutral beam injection (NBI) particle source for the density peaking. The experimental 3-point collisionality scans include L-mode, and H-mode (D and H and higher beta D plasma) plasmas in a total of 12 discharges. Experimental results presented in (Tala et al 2017 44th EPS Conf.) indicate that for the H-mode scans, the NBI particle source plays an important role for the density peaking, whereas for the L-mode scan, the influence of the particle source is small. In general, both the interpretative and predictive transport simulations support the experimental conclusions on the role of the NBI particle source for the 12 JET discharges.
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| 7. |
- Eriksson, Therese, et al.
(author)
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Crystal and magnetic structure of Mn3IrSi
- 2004
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 69:5, s. 054422-
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Journal article (peer-reviewed)abstract
- A new ternary Ir-Mn-Si phase with stoichiometry Mn3IrSi has been synthesized and found to crystallize in the cubic AlAu4-type structure, space group P213 with Z=4, which is an ordered form of the β-Mn structure. The unit cell dimension was determined by x-ray powder diffraction to a=6.4973(3)Å. In addition to the crystal structure, we have determined the magnetic structure and properties using superconducting quantum interference device magnetometry and Rietveld refinements of neutron powder diffraction data. A complex noncollinear magnetic structure is found, with magnetic moments of 2.97(4)μB at 10 K only on the Mn atoms. The crystal structure consists of a triangular network built up by Mn atoms, on which the moments are rotated 120° around the triangle axes. The magnetic unit cell is the same as the crystallographic and carries no net magnetic moment. The Néel temperature was determined to be 210 K. A first-principles study, based on density functional theory in a general noncollinear formulation, reproduces the experimental results with good agreement. The observed magnetic structure is argued to be the result of frustration of antiferromagnetic couplings by the triangular geometry.
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| 8. |
- Eriksson, Therese, et al.
(author)
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Cycloidal magnetic order in the compound IrMnSi
- 2005
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 71:17
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Journal article (peer-reviewed)abstract
- A new compound, IrMnSi, has been synthesized, and its crystal structure and magnetic properties have been investigated by means of neutron powder diffraction, magnetization measurements, and first-principles theory. The crystal structure is found to be of the TiNiSi type (ordered Co2P, space groupPnma). The Mn-projected electronic states are situated at the Fermi level, giving rise to metallic binding, whereas a certain degree of covalent character is observed for the chemical bond between the Ir and Si atoms. A cycloidal, i.e., noncollinear, magnetic structure was observed below 460 K, with the propagation vector q=[0,0,0.4530(5)] at 10 K. The magnetism is dominated by large moments on the Mn sites, 3.8μB∕atom from neutron diffraction. First-principles theory reproduces the propagation vector of the experimental magnetic structure as well as the angles between the Mn moments. The calculations further result in a magnetic moment of 3.2μB for the Mn atoms, whereas the Ir and Si moments are negligible, in agreement with observations. A calculation that more directly incorporates electron-electron interactions improves the agreement between the theoretical and experimental magnetic moments. A band mechanism is suggested to explain the observed magnetic order.
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| 9. |
- Eriksson, Therese, et al.
(author)
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Structural and magnetic characterization of Mn3IrGe and Mn3Ir(Si1-xGex) : experiments and theory
- 2004
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In: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596 .- 1095-726X. ; 177:11, s. 4058-4066
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Journal article (peer-reviewed)abstract
- The Structural and magnetic propertiesof a new ternary Ir-Mn-Ge phase, Mn3IrGe, as well as the solid solution Mn3Ir(Si1_xGex), O ordering is found below a critical temperature of about 225 K. The magnetic structure is noncollinear, as a result of frustrated magnetic interactions on a triangular network of Mn atoms, on which the moments rotate 120° around the triangle axes. The magnitude of the magnetic moment at 10 K is 3.39(4) µB for Mn3IrGe. The theoretical calculations reproduce with very good accuracy the magnitudes as well as the directions of the experimentally observed magnetic moments.
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| 10. |
- Maggi, C. F., et al.
(author)
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Isotope identity experiments in JET-ILW with H and D L-mode plasmas
- 2019
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In: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 59:7
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Journal article (peer-reviewed)abstract
- NBI-heated L-mode plasmas have been obtained in JET with the Be/W ITER-like wall (JET-ILW) in H and D, with matched profiles of the dimensionless plasma parameters, rho*, nu*, beta and q in the plasma core confinement region and same T-i/T-e and Z(eff). The achieved isotope identity indicates that the confinement scale invariance principle is satisfied in the core confinement region of these plasmas, where the dominant instabilities are Ion Temperature Gradient (ITG) modes. The dimensionless thermal energy confinement time, Omega(i) tau(E,th), and the scaled core plasma heat diffusivity, A chi(eff)/B-T, are identical in H and D within error bars, indicating lack of isotope mass dependence of the dimensionless L-mode thermal energy confinement time in JET-ILW. Predictive flux driven simulations with JETTO-TGLF of the H and D identity pair is in very good agreement with experiment for both isotopes: the stiff core heat transport, typical of JET-ILW NBI heated L-modes, overcomes the local gyro-Bohm scaling of gradient-driven TGLF, explaining the lack of isotope mass dependence in the confinement region of these plasmas. The effect of E x B shearing on the predicted heat and particle transport channels is found to be negligible for these low beta and low momentum input plasmas.
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