| 1. |
- O'Riordan, Marguerite, et al.
(författare)
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Are European clinical trial funders policies on clinical trial registration and reporting improving? A cross-sectional study
- 2023
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Ingår i: Journal of Clinical and Translational Science. - 2059-8661. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Objectives:Assess the extent to which the clinical trial registration and reporting policies of 25 of the world’s largest public and philanthropic medical research funders meet best practice benchmarks as stipulated by the 2017 WHO Joint Statement, and document changes in the policies and monitoring systems of 19 European funders over the past year.Design, Setting, Participants:Cross-sectional study, based on assessments of each funder’s publicly available documentation plus validation of results by funders. Our cohort includes 25 of the largest medical research funders in Europe, Oceania, South Asia, and Canada.Interventions:Scoring all 25 funders using an 11-item assessment tool based on WHO best practice benchmarks, grouped into three primary categories: trial registries, academic publication, and monitoring, plus validation of results by funders.Main outcome measures:How many of the 11 WHO best practice items each of the 25 funders has put into place, and changes in the performance of 19 previously assessed funders over the preceding year.Results:The 25 funders we assessed had put into place an average of 5/11 (49%) WHO best practices. Only 6/25 funders (24%) took the PI’s past reporting record into account during grant application reviews. Funders’ performance varied widely from 0/11 to 11/11 WHO best practices adopted. Of the 19 funders for which 2021(2) baseline data was available, 10/19 (53%) had strengthened their policies over the preceding year.Conclusions:Most medical research funders need to do more to curb research waste and publication bias by strengthening their clinical trial policies.
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| 2. |
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| 3. |
- Adloff, C, et al.
(författare)
-
A measurement of the t dependence of the helicity structure of diffractive rho meson electroproduction at HERA
- 2002
-
Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 539:1-2, s. 25-39
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Tidskriftsartikel (refereegranskat)abstract
- The helicity structure of the diffractive electroproduction of rho mesons, e + p --> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV2, where t' = - min. The data used are collected with the HI detector at HERA in the kinematic domain 2.5 < Q(2) < 60 GeV2, 40 < W < 120 GeV No t dependence of the r(00)(04) spin density matrix element is found. A significant t dependent helicity non-conservation from the virtual photon to the rho meson is observed for the spin density matrix element combinations r(00)(5) + 2r(11)(5) and r(00)(1) + 2r(11)(1). These t dependences are consistently described by a perturbative QCD model based on the exchange of two gluons.
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| 4. |
- Adloff, C, et al.
(författare)
-
Diffractive photoproduction of psi(2S) mesons at HERA
- 2002
-
Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 541:3-4, s. 251-264
-
Tidskriftsartikel (refereegranskat)abstract
- Results on diffractive photoproduction of psi(2S) mesons are presented using data collected between 1996 and 2000 with the H1 detector at the HERA ep collider. The data correspond to an integrated luminosity of 77 pb(-1). The energy dependence of the diffractive psi(2S) cross section is found to be similar to or possibly somewhat steeper than that for J/psi mesons. The dependences of the elastic and proton dissociative psi(2S) photoproduction cross sections on the squared momentum transfer t at the proton vertex are measured. The t-dependence of the elastic channel, parametrised as e(bt), yields b(el)(psi(2S)) = (4.31 +/- 0.57 +/- 0.46) GeV-2, compatible with that of the J/psi. For the proton dissociative channel the result b(pd)(psi(2S)) = (0.59 +/- 0.13 +/- 0.12) GeV-2 is 2.3 standard deviations smaller than that measured for the J/psi. With proper account of the individual wavefunctions theoretical predictions based on perturbative QCD are found to describe the measurements well. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 5. |
- Adloff, C, et al.
(författare)
-
Energy flow and rapidity gaps between jets in photoproduction at HERA
- 2002
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 24:4, s. 517-527
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Tidskriftsartikel (refereegranskat)abstract
- Dijet events in photon-proton collisions in which there is a large pseudorapidity separation, Deltaeta > 2.5 between the two highest E-T jets are studied with the H1 detector at HERA. The inclusive dijet cross sections are measured as functions of the longitudinal momentum fractions of the proton and photon which participate in the production of the jets, x(p)(jets) and x(gamma)(jets) respectively, Deltaeta, the pseudorapidity P separation between the two highest E-T jets, and E-T(gap), the total summed transverse energy between the jets. Rapidity gap events are defined as events in which E-T(gap) is less than E-T(cut), for E-T(cut) varied between jets 0.5 and 2.0 GeV. The fraction of dijet events with a rapidity gap is measured differentially in Deltaeta, x(p)(jets) and x(gamma)(jets). An excess of events with rapidity gaps at low values of E-T(cut) is observed above the expectation from standard photoproduction processes. This excess can be explained by the exchange of a strongly interacting colour singlet object between the jets.
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| 6. |
- Adloff, C, et al.
(författare)
-
Inelastic leptoproduction of J/psi mesons at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 41-53
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Tidskriftsartikel (refereegranskat)abstract
- The leptoproduction of J/psi mesons is studied in inelastic reactions for four momentorri transfers 2 < Q(2) < 100GeV(2). The data were taken with the H1 detector at the electron proton collider HERA and correspond to an integrated luminosity of 77 pb(-1). Single differential and double differential cross sections are measured with increased precision compared with previous analyses. New leading order calculations within the non-relativistic QCD factorisation approach including colour octet and colour singlet contributions are compared with the data and are found to give a reasonable description of most distributions. An exception is the shape of the distribution in the J/psi fractional energy. z, which deviates significantly from that of the data. Comparisons with photoproduction are made and the polarisation of the produced J/psi meson is analysed.
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| 7. |
- Adloff, C, et al.
(författare)
-
Inelastic photoproduction of J/psi mesons at HERA
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 25-39
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Tidskriftsartikel (refereegranskat)abstract
- An analysis of inelastic photoproduction of J/psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80 pb(-1), Differential and double I < P-t/psi(2) < differential cross sections are measured in a wide kinematic region: 60 < W-gammap < 260 GeV, 1 p(t,psi)(2) < 60 GeV2 and 0.05 < z < 0.9. where z is the fraction of the energy of the exchanged photon transferred to the J/psi meson in the rest frame of the target proton. Cross sections at z less than or similar to 0.3 are presented for the first time. Theoretical calculations within the Colour Singlet Model at NLO for direct photon processes are shown to give a good description of the data in the medium z region (0.3 < z < 0.9) up to the highest p(t,psi)(2) values. A calculation using a k(t) factorisation approach in LO in the Colour Singlet Model is also able to describe these data. The data in the full z range are also compared to LO calculations within a non-relativistic QCD framework including colour octet and colour singlet contributions for direct and resolved photons. It seems possible to reconcile data and theory with modest contributions from colour octet processes. The polarisation of the J/psi meson is measured as a function of z and p(t,psi) and is reasonably described by the theoretical predictions.
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| 8. |
- Adloff, C, et al.
(författare)
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Measurement of D*(+/-) meson production and F-2(c) in deep-inelastic scattering at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 528:3-4, s. 199-214
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Tidskriftsartikel (refereegranskat)abstract
- The inclusive production of D*+/-(2010) mesons in deep-inelastic scattering is studied with the HI detector at HERA. In the kinematic region 1 < Q(2) < 100 GeV2 and 0.05 < y < 0.7 an e(+) p cross section for inclusive D*+/- meson production of 8.50 +/- 0.42(stat.)(-100)(+1.21)(syst.) nb is measured in the visible range p(tD*) > 1.5 GeV and eta(D*) < 1.5. Single and double differential inclusive D*+/- meson cross sections are compared to perturbative QCD calculations in two different evolution schemes, The charm contribution to the proton structure, F-c(2)(x, Q(2)), is determined by extrapolating the visible charm cross section to the full phase space. This contribution is found to rise from about 10% at Q(2) = 1.5 GeV2 to more than 25% at Q(2) = 60 GeV2 corresponding to x values ranging from 5 x 10(-5) to 3 x 10(-3). (C) 2002 Elsevier Science B.V. All rights reserved.
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| 9. |
- Adloff, C, et al.
(författare)
-
Measurement of dijet cross sections in photoproduction at HERA
- 2002
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 25:1, s. 13-23
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Tidskriftsartikel (refereegranskat)abstract
- Dijet cross sections as functions of several jet observables are measured in photoproduction using the HI detector at HERA. The data sample comprises e(+)p data with an integrated luminosity of 319 pb(-1). Jets are selected using the inclusive k(perpendicular to) algorithm with a minimum transverse energy of 25 GeV for the leading jet. The phase space covers longitudinal proton momentum fraction x(p) and photon longitudinal momentum fraction x(gamma) in the ranges 0.05 < x(p) < 0.6 and 0.1 < x(gamma) < 1. The predict ions of next-to-leading order perturbative QCD, including recent photon and proton parton densities, are found to be compatible with the data in a wide kinematical range.
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| 10. |
- Adloff, C, et al.
(författare)
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Measurement of dijet electroproduction at small jet separation
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 24:1, s. 33-41
-
Tidskriftsartikel (refereegranskat)abstract
- Deep-inelastic scattering data in the range 150 < Q(2) < 35000 GeV2 are used to investigate the minimum jet separation necessary to allow accurate description of the rate of dijet production using next-to-leading order perturbative QCD calculations. The required jet separation is found to be small, allowing about 1/3 of DIS data to be classified as dijet, as opposed to approximately 1/10 with more typical jet analyses. A number of precision measurements made using this dijet sample are well described by the calculations. The data are also described by the combination of leading order matrix elements and parton showers, as implemented in the QCD based Monte Carlo model RAPGAP.
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| 11. |
- Adloff, C, et al.
(författare)
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Measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA
- 2002
-
Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 542:3-4, s. 193-206
-
Tidskriftsartikel (refereegranskat)abstract
- A measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA is presented based on data with an integrated luminosity of 21.1 pb(-1). The measurement is performed for photon virtualities Q(2) between 5 and 100 GeV2, differentially in Q(2), in the jet transverse energy E-T, in E-T(2)/Q(2) and in the pseudorapidity eta(lab). With the renormalization scale mu(R) = E-T, perturbative QCD calculations in next-to-leading order (NLO) give a good description of the data in most of the phase space. Significant discrepancies are observed only for jets in the proton beam direction with ET below 20 GeV and Q2 below 20 GeV2. This corresponds to the region in which NLO corrections are largest and further improvement of the calculations is thus of particular interest.
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| 12. |
- Adloff, C, et al.
(författare)
-
Search for excited neutrinos at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 525:1-2, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for excited neutrinos using e(-) p data taken by the H1 experiment at HERA at a center-of-mass energy of 318 GeV with an integrated luminosity of 15 pb(-1). No evidence for excited neutrino production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the compositeness scale, f/Lambda, independently of the relative couplings to the SU(2) and U(1) gauge bosons. These limits extend the excluded region to higher masses than has been possible in previous searches at other colliders.
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| 13. |
- Adloff, C, et al.
(författare)
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Search for odderon-induced contributions to exclusive pi(0) photoproduction at HERA
- 2002
-
Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 544:1-2, s. 35-43
-
Tidskriftsartikel (refereegranskat)abstract
- A search for contributions to the reaction ep --> epi(0)N* from photon-odderon fusion in the photoproduction regime at HERA is reported, at an average photon-proton centre-of-mass energy = 215 GeV. The measurement proceeds via detection of the pi(0) decay photons, a leading neutron from the N* decay, and the scattered electron. No pi(0) signal is observed and an upper limit on the cross section for the photon-odderon fusion process of sigma(gammap --> pi(0)N*) < 49 nb at the 95% confidence level is derived, integrated over the experimentally accessible range of the squared four-momentum transfer at the nucleon vertex 0.02 < < 0.3 GeV2. This excludes a recent prediction from a calculation based on a non-perturbative QCD model of a photon-odderon fusion cross section above 200 nb. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 14. |
- Aumailley, M, et al.
(författare)
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A simplified laminin nomenclature
- 2005
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Ingår i: Matrix Biology. - : Elsevier BV. - 1569-1802 .- 0945-053X. ; 24:5, s. 326-332
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Forskningsöversikt (refereegranskat)abstract
- A simplification of the laminin nomenclature is presented. Laminins are multidomain heterotrimers composed of alpha, beta and gamma chains. Previously, laminin trimers were numbered with Arabic numerals in the order discovered, that is laminins-1 to -5. We introduce a new identification system for a trimer using three Arabic numerals, based on the alpha, beta and gamma chain numbers. For example, the laminin with the chain composition alpha 5 beta 1 gamma 1 is termed laminin-511, and not laminin-10. The current practice is also to mix two overlapping domain and module nomenclatures. Instead of the older Roman numeral nomenclature and mixed nomenclature, all modules are now called domains. Some domains are renamed or renumbered. Laminin epidermal growth factor-like (LE) domains are renumbered starting at the N-termini, to be consistent with general protein nomenclature. Domain IVb of alpha chains is named laminin 4a (L4a), domain IVa of alpha chains is named L4b, domain IV of gamma chains is named L4, and domain IV of beta chains is named laminin four (LF). The two coiled-coil domains I and II are now considered one laminin coiled-coil domain (LCC). The interruption in the coiled-coil of 13 chains is named laminin beta-knob (L beta) domain. The chain origin of a domain is specified by the chain nomenclature, such as alpha IL4a. The abbreviation LM is suggested for laminin. Otherwise, the nomenclature remains unaltered.
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| 15. |
- Bott, Lukas Thomas, et al.
(författare)
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Coulomb dissociation of O-16 into He-4 and C-12
- 2023
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Ingår i: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
-
Konferensbidrag (refereegranskat)abstract
- We measured the Coulomb dissociation of O-16 into He-4 and C-12 within the FAIR Phase-0 program at GSI Helmholtzzentrum fur Schwerionenforschung Darmstadt, Germany. From this we will extract the photon dissociation cross section O-16(alpha,gamma)C-12, which is the time reversed reaction to C-12(alpha,gamma)O-16. With this indirect method, we aim to improve on the accuracy of the experimental data at lower energies than measured so far. The expected low cross section for the Coulomb dissociation reaction and close magnetic rigidity of beam and fragments demand a high precision measurement. Hence, new detector systems were built and radical changes to the (RB)-B-3 setup were necessary to cope with the high-intensity O-16 beam. All tracking detectors were designed to let the unreacted O-16 ions pass, while detecting the C-12 and He-4.
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| 16. |
- Bruckner, Martin, et al.
(författare)
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Quantifying the global cropland footprint of the European Union's non-food bioeconomy
- 2019
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- A rapidly growing share of global agricultural areas is devoted to the production of biomass for non-food purposes. The expanding non-food bioeconomy can have far-reaching social and ecological implications; yet, the non-food sector has attained little attention in land footprint studies. This paper provides the first assessment of the global cropland footprint of non-food products of the European Union (EU), a globally important region regarding its expanding bio-based economy. We apply a novel hybrid land flow accounting model, combining the biophysical trade model LANDFLOW with the multi-regional input-output model EXIOBASE. The developed hybrid approach improves the level of product and country detail, while comprehensively covering all global supply chains from agricultural production to final consumption, including highly processed products, such as many non-food products. The results highlight the EU's role as a major processing and the biggest consuming region of cropland-based non-food products, while at the same time relying heavily on imports. Two thirds of the cropland required to satisfy the EU's non-food biomass consumption are located in other world regions, particularly in China, the US and Indonesia, giving rise to potential impacts on distant ecosystems. With almost 39% in 2010, oilseeds used to produce for example biofuels, detergents and polymers represented the dominant share of the EU's non-food cropland demand. Traditional non-food biomass uses, such as fibre crops for textiles and animal hides and skins for leather products, also contributed notably (22%). Our findings suggest that if the EU Bioeconomy Strategy is to support global sustainable development, a detailed monitoring of land use displacement and spillover effects is decisive for targeted and effective EU policy making.
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| 17. |
- Burk, Anne-Maud, et al.
(författare)
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Early Complementopathy After Multiple Injuries in Humans.
- 2012
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Ingår i: Shock. - 1540-0514. ; 37:4, s. 348-354
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: After severe tissue injury, innate immunity mounts a robust systemic inflammatory response. However, little is known about the immediate impact of multiple trauma on early complement function in humans. In the present study we hypothesized that multiple trauma results in immediate activation, consumption and dysfunction of the complement cascade and that the resulting severe "complementopathy" may be associated with morbidity and mortality.Therefore a prospective multicenter study with 25 healthy volunteers and 40 polytrauma patients (mean injury severity score [ISS] = 30.3 ± 2.9) was performed. After polytrauma serum was collected as early as possible at the scene, upon admission to the emergency room and 4, 12, 24, 120 and 240 hours post trauma and analysed for the complement profile. Complement hemolytic activity (CH-50) was massively reduced within the first 24 h after injury, recovered only 5 days after trauma and discriminated between lethal and non-lethal 28-day outcome. Serum levels of the complement activation products C3a and C5a were significantly elevated throughout the entire observation period and correlatedwith the severity of traumatic brain injury and survival. The soluble terminal complement complex SC5b-9 and mannose-binding lectin (MBL) showed a biphasic response after trauma. Key fluid phase inhibitors of complement, such as C4b-binding protein (C4BP) and factor I, were significantly diminished early after trauma.The present data indicate an almost synchronically rapid activation and dysfunction of complement suggesting a trauma-induced "complementopathy" early after injury. These events may participate to the impairment of the innate immune response observed after severe trauma.
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| 18. |
- Cavalieri, Sandra, et al.
(författare)
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The EU’s Arctic Footprint
- 2011
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Ingår i: Journal of Nordregio. ; :2
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 19. |
- de Schutter, Liesbeth, et al.
(författare)
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Bioeconomy Transitions through the Lens of Coupled Social-Ecological Systems : A Framework for Place-Based Responsibility in the Global Resource System
- 2019
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 11:20
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Tidskriftsartikel (refereegranskat)abstract
- Bioeconomy strategies in high income societies focus at replacing finite, fossil resources by renewable, biological resources to reconcile macro-economic concerns with climate constraints. However, the current bioeconomy is associated with critical levels of environmental degradation. As a potential increase in biological resource use may further threaten the capacity of ecosystems to fulfil human needs, it remains unclear whether bioeconomy transitions in high income countries are sustainable. In order to fill a gap in bioeconomy sustainability assessments, we apply an ontological lens of coupled social-ecological systems to explore critical mechanisms in relation to bioeconomy activities in the global resource system. This contributes to a social-ecological systems (SES)-based understanding of sustainability from a high income country perspective: the capacity of humans to satisfy their needs with strategies that reduce current levels of pressures and impacts on ecosystems. Building on this notion of agency, we develop a framework prototype that captures the systemic relation between individual human needs and collective social outcomes on the one hand (micro-level) and social-ecological impacts in the global resource system on the other hand (macro-level). The BIO-SES framework emphasizes the role of responsible consumption (for physical health), responsible production (to reduce stressors on the environment), and the role of autonomy and self-organisation (to protect the reproduction capacity of social-ecological systems). In particular, the BIO-SES framework can support (1) individual and collective agency in high income country contexts to reduce global resource use and related ecosystem impacts with a bioeconomy strategy, (2) aligning social outcomes, monitoring efforts and governance structures with place-based efforts to achieve the SDGs, as well as (3), advancing the evidence base and social-ecological theory on responsible bioeconomy transitions in the limited biosphere.
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| 20. |
- Gobel, K., et al.
(författare)
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Coulomb dissociation of 16O into 4He and 12C
- 2020
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1668:1
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Konferensbidrag (refereegranskat)abstract
- We measured the Coulomb dissociation of 16O into 4He and 12C at the R3B setup in a first campaign within FAIR Phase 0 at GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt. The goal was to improve the accuracy of the experimental data for the 12C(a,?)16O fusion reaction and to reach lower center-ofmass energies than measured so far. The experiment required beam intensities of 109 16O ions per second at an energy of 500 MeV/nucleon. The rare case of Coulomb breakup into 12C and 4He posed another challenge: The magnetic rigidities of the particles are so close because of the same mass-To-charge-number ratio A/Z = 2 for 16O, 12C and 4He. Hence, radical changes of the R3B setup were necessary. All detectors had slits to allow the passage of the unreacted 16O ions, while 4He and 12C would hit the detectors' active areas depending on the scattering angle and their relative energies. We developed and built detectors based on organic scintillators to track and identify the reaction products with sufficient precision.
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| 21. |
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| 22. |
- Heil, M., et al.
(författare)
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A new Time-of-flight detector for the R 3 B setup
- 2022
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 58:12
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Tidskriftsartikel (refereegranskat)abstract
- We present the design, prototype developments and test results of the new time-of-flight detector (ToFD) which is part of the R3B experimental setup at GSI and FAIR, Darmstadt, Germany. The ToFD detector is able to detect heavy-ion residues of all charges at relativistic energies with a relative energy precision σΔE/ ΔE of up to 1% and a time precision of up to 14 ps (sigma). Together with an elaborate particle-tracking system, the full identification of relativistic ions from hydrogen up to uranium in mass and nuclear charge is possible.
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| 23. |
- Kahnt, Maik, et al.
(författare)
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Multi-slice ptychography enables high-resolution measurements in extended chemical reactors
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Ptychographic X-ray microscopy is an ideal tool to observe chemical processes under in situ conditions. Chemical reactors, however, are often thicker than the depth of field, limiting the lateral spatial resolution in projection images. To overcome this limit and reach higher lateral spatial resolution, wave propagation within the sample environment has to be taken into account. Here, we demonstrate this effect recording a ptychographic projection of copper(I) oxide nanocubes grown on two sides of a polyimide foil. Reconstructing the nanocubes using the conventional ptychographic model shows the limitation in the achieved resolution due to the thickness of the foil. Whereas, utilizing a multi-slice approach unambiguously separates two sharper reconstructions of nanocubes on both sides of the foil. Moreover, we illustrate how ptychographic multi-slice reconstructions are crucial for high-quality imaging of chemical processes by ex situ studying copper(I) oxide nanocubes grown on the walls of a liquid cell.
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| 24. |
- Kledwig, Christian, et al.
(författare)
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A Study on the accuracy of Thermography-based Temperature measurement in Powder-fed directed energy deposition
- 2020
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Ingår i: 20th CIRP Conference on Electro Physical and Chemical Machining. - : Elsevier. ; , s. 35-41
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Konferensbidrag (refereegranskat)abstract
- Due to continuous development and increasingly deep understanding of the additive process, directed-energy deposition (DED) is becoming more and more interesting for industrial use. However, both the number of influencing factors and the process complexity, still require well-trained operators who can monitor and understand the machine tools. In order to facilitate the operators and to enable longer unattended processes, higher process safety, reliable monitoring systems and closed-loop controller are required. For example, despite a large number of investigations, the monitoring and control of the temperature distribution within the work piece still poses a big challenge.This study focusses on workpiece temperature measurement using a thermal imaging camera that observes the entire machining area. In order examine the measurement error caused by different viewing angles (φ = 0 … 75°), object temperatures (T = 333 … 1073K), surface conditions (welded and milled) and materials (316L, Inconel 718 and CuAl10) commonly used in DED, several approaches were followed using a thermal camera.It was found that surface condition and material cause the greatest measuring errors (up to +325K |−453K).). However, the measuring errors can be significantly reduced by suitable selection of the emissivity, so that it is possible to measure even the milled CuAl10 surface at a known viewing angle with a measuring error of +13.3% |−10.9%.
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| 25. |
- Kledwig, Christian, et al.
(författare)
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Image-based algorithm for nozzle adhesion detection in powder-fed directed-energy deposition
- 2020
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Ingår i: Journal of laser applications. - : Laser Institute of America. - 1042-346X .- 1938-1387. ; 32:2
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Tidskriftsartikel (refereegranskat)abstract
- The rapidly growing technological innovation of directed energy deposition leads to an increase in part complexity as well as quality and mechanical properties of manufacturable components. However, the variety of process parameters and influencing factors still requires skilled operators, who observe the machine tools. For an unobserved use of deposition welding machines, well parametrized and validated monitoring systems have to analyze the process to detect irregularities and finally initiate a machine stop. This study focuses on nozzle adhesions that frequently occur when tool or high-speed steels are processed. This effect leads to decreasing quality or ultimately to a failure of the whole welding process. In this work, the authors present an algorithm and the corresponding parametrization to automatically detect nozzle adhesions based on images from a coaxial camera, integrated in the laser head. The algorithm is based on a detailed image analysis from which temporal and spatial patterns are derived. In particular, the algorithm calculates a nozzle adhesion indicator based on the heat intensity distribution in an experimentally derived shaped area on the inner nozzle boundary. It is parametrized in such a way that process-critical adhesions are detected. The algorithm was parametrized using an experimental setup with four materials: stainless steel (X2CrNiMo17-12-2), tool steel (X35CrMoMn7-2-1), high-speed steel (HS6-5-2C), and the nickel-based alloy NiCr19NbMo.
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| 26. |
- Leonarski, Filip, et al.
(författare)
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Jungfraujoch : hardware-accelerated data-acquisition system for kilohertz pixel-array X-ray detectors
- 2023
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Ingår i: Journal of Synchrotron Radiation. - 1600-5775. ; 30, s. 227-234
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Tidskriftsartikel (refereegranskat)abstract
- The JUNGFRAU 4-megapixel (4M) charge-integrating pixel-array detector, when operated at a full 2 kHz frame rate, streams data at a rate of 17 GB s-1. To operate this detector for macromolecular crystallography beamlines, a data-acquisition system called Jungfraujoch was developed. The system, running on a single server with field-programmable gate arrays and general-purpose graphics processing units, is capable of handling data produced by the JUNGFRAU 4M detector, including conversion of raw pixel readout to photon counts, compression and on-the-fly spot finding. It was also demonstrated that 30 GB s-1 can be handled in performance tests, indicating that the operation of even larger and faster detectors will be achievable in the future. The source code is available from a public repository.
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| 27. |
- Schropp, Andreas, et al.
(författare)
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PtyNAMi : Ptychographic nano-analytical microscope
- 2020
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Ingår i: Journal of Applied Crystallography. - 0021-8898. ; 53, s. 957-971
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Tidskriftsartikel (refereegranskat)abstract
- Ptychographic X-ray imaging at the highest spatial resolution requires an optimal experimental environment, providing a high coherent flux, excellent mechanical stability and a low background in the measured data. This requires, for example, a stable performance of all optical components along the entire beam path, high temperature stability, a robust sample and optics tracking system, and a scatter-free environment. This contribution summarizes the efforts along these lines to transform the nanoprobe station on beamline P06 (PETRAIII) into the ptychographic nano-analytical microscope (PtyNAMi).
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| 28. |
- Sguazzin, M., et al.
(författare)
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Indirect measurements of neutron-induced reaction cross sections at storage rings
- 2023
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Ingår i: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
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Konferensbidrag (refereegranskat)abstract
- Neutron-induced reaction cross sections of unstable nuclei are essential for understanding the synthesis of heavy elements in stars. However, their measurement is very difficult due to the radioactivity of the targets involved. We propose to circumvent this problem by using for the first time the surrogate reaction method in inverse kinematics at heavy-ion storage rings. In this contribution, we describe the developments we have done to perform surrogate-reaction studies at the storage rings of GSI/FAIR. In particular, we present the first results of the proof of principle experiment, which we conducted recently at the Experimental Storage Ring (ESR).
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| 29. |
- Vanham, Davy, et al.
(författare)
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Environmental footprint family to address local to planetary sustainability and deliver on the SDGs
- 2019
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Ingår i: Science of the Total Environment. - : ELSEVIER. - 0048-9697 .- 1879-1026. ; 693
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Forskningsöversikt (refereegranskat)abstract
- The number of publications on environmental footprint indicators has been growing rapidly, but with limited efforts to integrate different footprints into a coherent framework. Such integration is important for comprehensive understanding of environmental issues, policy formulation and assessment of trade-offs between different environmental concerns. Here, we systematize published footprint studies and define a family of footprints that can be used for the assessment of environmental sustainability. We identify overlaps between different footprints and analyse how they relate to the nine planetary boundaries and visualize the crucial information they provide for local and planetary sustainability. In addition, we assess how the footprint family delivers on measuring progress towards Sustainable Development Goals (SDGs), considering its ability to quantify environmental pressures along the supply chain and relating them to the water-energy-food-ecosystem (WEFE) nexus and ecosystem services. We argue that the footprint family is a flexible framework where particular members can be included or excluded according to the context or area of concern. Our paper is based upon a recent workshop bringing together global leading experts on existing environmental footprint indicators. Elsevier B.V.
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