| 1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 4. |
- Carsten, Hobohm, et al.
(författare)
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Land Use Change and the Future of Biodiversity
- 2021
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Ingår i: Perspectives for Biodiversity and Ecosystems. - Cham : Springer. - 2214-2827 .- 2214-2835. - 9783030577094 ; , s. 451-483
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This synthesis report is a meta-analysis of perspectives for biodiversity and ecosystems, with a strong focus on human impacts on the environment, and a work order to enable and manage the protection, survival and evolution of all species on Earth. The goal is to protect nature without any further species loss (Zero Extinction). With this report, we assess alarming signals from the environment; determine the needs of threatened biota and the required actions to manage and protect landscapes and ecosystems; and identify some inescapable tendencies, challenges but also possibilities. The story of humans on Earth is at a critical juncture. Human behaviour is inherently dependent on physical and societal relations, including orientation and positioning within the physical environment. There is no single cultural benefit that is independent of provisioning through ecosystem services. Humans are part of the environment, acquire all needs from it and, as such, depend on its integrity and management for life and well-being. Moreover, if human impacts to the environment continue to increase the risk of rebound effects impacting human life and health will increase as well. Whenever a biome, ecosystem, habitat or species is heavily impacted or threatened with irreversible transformation or extinction, prevailing environmental conditions are relevant and should be observed, analysed and remedied as necessary and where possible. Ecology examines the evolutionary, historical and more recent interplay between biological life and the abiotic environment, while the role of social science and the humanities is to question the physical and social landscape, and how and why it should be protected or influenced, e.g. by nature conservation measures under political and economic, ethical and legal considerations. Thus, for all inter-relationships between natural and sociocultural processes, a joint venture in the form of social-ecological thinking is necessary to combine natural sciences and the humanities. With this contribution, we combine ecological knowledge with social science knowledge (s.l.) through the participation of scientists of many different disciplines. We analyse history and current processes to assess risks, threats and possibilities, and call for an array of regulations and measures that can contribute to halting of biodiversity loss and that assist in achieving a sustainable future. Regulations comprise creativity, cultural incentives, social norms, environmental education and economic investments—such as payments for sustainable agriculture, forestry, and fishery; investments in water, soil and air purity; and much clearer and stronger legal restrictions and consequences around waste streams and environmental degradation. Moreover, a gradual change from profit-oriented economies in the short-run to environmentally-sensitive policies that include systematic environmental programmes in the long term might help to decrease pressure on ecosystems and biota. Such economics might also include the real costs of consumerism, including the impacts of particular products on the environment and on human health. The greatest hurdle for the continued existence of many critically endangered species is the impact of widespread anthropogenic-driven change in the usage of water, air and land, and industry intensification in agriculture, aquaculture, forestry, urbanisation, transportation and mining sectors. However, there is not one simple solution to solve these issues. We conclude that many of the current developments have to be adjusted or gradually altered in a step-wise manner, especially with respect to existing sociocultural behaviours. Therefore, various concepts, decisions and measures should be discussed and implemented at all scales from local to supranational and among researchers, practitioners and politicians.
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| 5. |
- Kern, Ralph, et al.
(författare)
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Coulomb Excitation of Proton-rich N = 80 Isotones at HIE-ISOLDE
- 2020
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1555:1
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Tidskriftsartikel (refereegranskat)abstract
- A projectile Coulomb-excitation experiment was performed at the radioactive ion beam facility HIE-ISOLDE at CERN. The radioactive 140Nd and 142Sm ions were post accelerated to the energy of 4.62 MeV/A and impinged on a 1.45 mg/cm2-thin 208Pb target. The γ rays depopulating the Coulomb-excited states were recorded by the HPGe-array MINIBALL. The scattered charged particles were detected by a double-sided silicon strip detector in forward direction. Experimental γ-ray intensities were used for the determination of electromagnetic transition matrix elements. Preliminary results for the reduced transition strength of the B(M1 23+ to 21+)=0.35(19) μN2 of 140Nd and a first estimation for 142Sm have been deduced using the Coulomb-excitation calculation software GOSIA. The 23+ states of 140Nd and 142Sm show indications of being the main fragment of the proton-neutron mixed-symmetry 21, ms+ state.
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| 6. |
- Kern, Ralph, et al.
(författare)
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Search for Isovector Valence-Shell Excitations in 140Nd and 142Sm via Coulomb excitation reactions of radioactive ion beams
- 2018
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Ingår i: International Conference on Nuclear Structure and Related Topics (NSRT18). - : EDP Sciences. - 2101-6275. ; 194
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Konferensbidrag (refereegranskat)abstract
- Projectile Coulomb excitation experiments were performed at HIE-ISOLDE at CERN with the radioactive ion beams of 140Nd and 142Sm. Ions with an energy of 4:62 MeV/A were impinging on a 1.45 mg/cm2 thick 208Pb target. The γ-rays depopulating the Coulomb-excited states were recorded by the HPGe-array MINIBALL and scattered particles were detected by a double-sided silicon strip detector. Experimental intensities were used for the determination of electromagnetic transition matrix elements. A preliminary result of the B(M1; 2+ 3 → 2+ 1) of 140Nd and an upper limit for the case of 142Sm are revealing the main fragments of the proton-neutron mixed-symmetry 2+ 1;ms states.
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| 7. |
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| 8. |
- Mushumbusi, Medard Zephyrin
(författare)
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Formal and Informal Practices for Affordable Urban housing : Case study: Dar es Salaam, Tanzania
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis attempts to ascertain the magnitude of the urban housingproblem in Tanzania and endeavours to evaluate the strategies that thegovernment has been employing to address this problem. Informal andformal practices in urban housing are compared. The role of networksand power relations are explored and discussed in relation to how theymay facilitate the provision of urban housing. By looking at urbanhousing from a governance perspective, the thesis explores thepotentials for delivery of urban housing A case study is carried out, looking at the housingpractices in urban areas from the perspective of actors and theirinstitutional domains of action. The aim is to ascertain the extent towhich the government, through its policies and through engagement ofother actors, could facilitate the supply of urban housing. The roles ofdifferent actors in the delivery and regulation of urban housing areinvestigated in the process of institutionalizing housing production. The study comprises eight chapters. The first twochapters present an introduction and the conceptual and theoreticalunderpinnings on which the research is based. Chapter three discusseshousing strategies in Tanzania and attempts to evaluate the regulatoryframework within which urban housing is provided. Chapter fourpresents the research methodology. Chapter five discusses findingsfrom the studied documents and findings from interviews with keypersons in the government and in the construction industry. Chaptersix presents findings from the case study areas. Chapter sevendiscusses findings from case study areas and uses findings fromchapter five as corroborating evidence. Chapter eight givesrecommendations including areas for further research. The main outcome of the study is that urban housing isstill far from being satisfactory despite different strategies and landand governance reforms by the government of Tanzania. The formalsystem is weak and the roles of key public actors are still bureaucratic,blurred and sometimes conflicting. As a result, there is littleparticipation of private actors and the civil society in the production ofurban housing. The thesis has found out that informal practices forurban housing tend to complement the weakening capacity of theformal system. However, the thesis argues that although the informalsystem of governance for urban housing is consolidating it proceedswithout being properly guided. Based on these findings, somerecommendations are given for policy intervention, and some areas forfurther/ future research are identified.
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| 9. |
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| 10. |
- Wegner, Carolyn, et al.
(författare)
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Variability in transport of terrigenous material on the shelves and the deep Arctic Ocean during the Holocene
- 2015
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Ingår i: Polar Research. - : Norwegian Polar Institute. - 0800-0395 .- 1751-8369. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- Arctic coastal zones serve as a sensitive filter for terrigenous matter input onto the shelves via river discharge and coastal erosion. This material is further distributed across the Arctic by ocean currents and sea ice. The coastal regions are particularly vulnerable to changes related to recent climate change. We compiled a pan-Arctic review that looks into the changing Holocene sources, transport processes and sinks of terrigenous sediment in the Arctic Ocean. Existing palaeoceanographic studies demonstrate how climate warming and the disappearance of ice sheets during the early Holocene initiated eustatic sea-level rise that greatly modified the physiography of the Arctic Ocean. Sedimentation rates over the shelves and slopes were much greater during periods of rapid sea-level rise in the early and middle Holocene, as a result of the relative distance to the terrestrial sediment sources. However, estimates of suspended sediment delivery through major Arctic rivers do not indicate enhanced delivery during this time, which suggests enhanced rates of coastal erosion. The increased supply of terrigenous material to the outer shelves and deep Arctic Ocean in the early and middle Holocene might serve as analogous to forecast changes in the future Arctic.
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| 11. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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