| 1. |
- Aad, G., et al.
(författare)
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- 2011
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Tidskriftsartikel (refereegranskat)
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| 2. |
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Övervakning av ängsfjärilar och humlor i Värmlands län 2005. Områdena Brunsberg, Örtensjöarna, Fensbol och Östmark, med en studie av biotopavtal för några fjärilar
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föreliggande rapport redovisar resultatet av inventering och övervakning av dagaktiva fjärilar och humlor (Figur 1-3) i fyra områden i Värmlands län 2005. Projektet har genomförts som en del av Länsstyrelsens miljöövervakning och förhoppningsvis kan undersökta områden och lokaler övervakas regelbundet framöver. Sådana tidsserier över arters förekomst behövs bl.a. som indikatorer i det svenska miljömålsarbetet för att kunna upptäcka eventuella långsiktiga förändringar. Många dagaktiva fjärilar och humlor kräver blomrika gräsmarker som födo- och/eller föryngringshabitat. Fjärilar förekommer ofta i s.k. metapopulationer och för att långsiktigt överleva behöver de tillräckligt många mer eller mindre stora öppna ytor inom tillräckligt nära spridningsavstånd. De öppna ytor som finns måste också vara av tillräckligt god kvalitet avseende tillgång på värdväxter, nektarväxter, vindskydd etc. (Thomas & Hanski 1997). Det är känt att utbredning och individtäthet under de senaste 50-60 åren minskat för många fjärilsarter (Eliasson m fl 2005, Nilsson & Franzén 2006) och humlor (Linkowski m fl 2004). En omstöpning av landskapet som följd av förändrat jord- och skogsbruk har inneburit en kraftig minskning av arealen blomrika gräsmarker i stora delar av Sverige, bland annat Värmland (Ihse 1995). En fortsatt utveckling där jordbruksmarker överges och tillåts växa igen, alternativt planteras med skog (Figur 4), är sannolik (t ex Schneider 2003). För svenskt vidkommande anses detta utgöra det största hotet mot en stor mängd arter inom olika växt och djurgrupper (Naturvårdsverket 1997, Gärdenfors 2005), och dagfjärilar löper risk att drabbas mycket hårt (Schneider 2003). För att få ökad förståelse för hur fjärilspopulationer påverkas av denna landskapsomvandling är det intressant att studera hur lokala fjärilspopulationers täthet varierar med avseende på lokal markanvändning.
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| 3. |
- Ridderstråle, Martin, et al.
(författare)
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Genetic dissection of type 2 diabetes.
- 2009
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Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 2008:Oct 19, s. 10-17
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Tidskriftsartikel (refereegranskat)abstract
- Compared to the successful probing of genetic causes of monogenic disorders, dissecting the genetics of complex polygenic diseases has until recently been a fairly slow and cumbersome process. With the introduction of whole genome wide association studies (WGAS) the situation dramatically changed in 2007. The results from several recent WGAS on type 2 diabetes (T2D) and obesity have identified at least eighteen genes consistently associated with T2D. Many of the genes implicate pancreatic beta-cell function in the pathogenesis of T2D whereas only one clearly associate with insulin resistance. The identified genes most likely merely represent the tip of the iceberg in the explanation behind T2D. Refined tools will have to provide a more complete picture of the genetic complexity of T2D over the next few years. In addition to common variants increasing susceptibility for the disease, rare variants with stronger effects, copy number variations, and epigenetic effects like DNA methylation and histone acetylation will become important. Nevertheless, today we are able for the first time to anticipate that the genetics of a complex disease like T2D really can be dissected.
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| 4. |
- Thodelius, Charlotta, 1975, et al.
(författare)
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(In-)equality before the law - house adapting policy in Sweden.
- 2018
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Ingår i: The International Conference Amps - Architecture, Media, Polics, Society. Health: The Design, Planning and Politics of How and Where We Live. UWE - University of the West of England, Bristol UK: 25-26 January 2018..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Arnby, Karl, 1974
(författare)
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Low-Temperature Oxidation of CO and Volatile Organic Compounds over Supported Platinum Catalysts
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The catalytic oxidation of carbon monoxide (CO) and volatile organic compounds (VOC) is important for the reduction of harmful emissions from both vehicles and from stationary sources. Both these applications suffer from poor catalytic efficiency at lower temperatures. The objective of this work was to gain a deeper understanding of the low-temperature oxidation of CO and VOC over alumina supported platinum catalysts. The work has been focused on the preparation of platinum-based model catalysts, extensive flow reactor studies and thorough sample characterisation. A new preparation method was used to prepare supported catalysts with platinum distributed locally in high concentrations on the alumina support. The purpose was to prepare catalysts that would retain the evolved reaction heat to a higher extent and thereby become more active at low temperatures than conventionally prepared catalysts. The catalysts prepared using this new method showed an improved low-temperature activity for the oxidation of CO, however, not for the oxidation of propene or propane. When considering heat transfer, calculations of both temporary effects and heat accumulation showed that the enhanced activity for CO oxidation can not be explained by a heat effect. Instead, mass transfer limitations probably improved the activity to a certain extent, and structural effects can also be of importance. The oxidation of propane over Pt/γ-Al2O3 was shown to be highly influenced by the oxygen concentration. Maximum activity was observed close to stoichiometric conditions. At net-oxidising conditions the catalysts were most likely passivated due to formation of platinum oxide. In a deactivation study, the influence of hexamethyldisiloxane (HMDS) on the oxidation of ethyl acetate over iron-promoted Pt/γ-Al2O3 samples was investigated. The catalytic deactivation was found to proceed as HMDS decomposed into silicate (SixOy), which blocks the active sites on the catalyst surface. The poisoning was found to be selective as silicon rather attached to platinum and iron sites than to alumina. Moreover, depending on the catalyst composition the deactivation was either reversible or irreversible. Promoting the Pt/γ-Al2O3 catalyst with iron increased the tolerance towards HMDS as fewer platinum sites were blocked by silicate.
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| 6. |
- Arnby, Karl, 1974, et al.
(författare)
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Investigation of Pt/γ-Al2O3 catalysts with locally high Pt concentrations for oxidation of CO at low temperatures
- 2004
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 0021-9517 .- 1090-2694. ; 221:1, s. 252-261
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Tidskriftsartikel (refereegranskat)abstract
- A new method for preparing supported catalysts, in which Pt was distributed in locally high concentrations on the γ-Al2O3 support, was studied. These catalysts were compared with a conventionally prepared Pt/γ-Al2O3 catalyst in which Pt was deposited evenly on the support. The object was to ascertain whether it is possible to prepare catalysts that retain heat released from exothermic reactions to a higher extent and thereby become more low-temperature active than a conventionally prepared catalyst. A significant improvement of the activity was observed for the catalysts prepared with locally high Pt concentrations when CO (1%, 1000 and 100 ppm) was oxidized at a constant O2 concentration (10%). The improved activity is discussed in terms of heat transfer, mass transfer, and structure sensitivity. Differences in heat transfer appear to be the least probable reason for the enhanced activity for the catalysts with locally higher Pt concentrations, whereas structural effects also seem to be an unlikely explanation. Differences in mass transfer seem, however, to be a more likely reason for the improved activity.
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| 7. |
- Adlmann, Franz, et al.
(författare)
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Normalization of stroboscopic neutron scattering experiments
- 2018
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 434, s. 61-65
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Tidskriftsartikel (refereegranskat)abstract
- Neutron scattering studies of kinetic processes are often flux limited. For processes which can be repeated many times, this can be mitigated by stroboscopic reintegration. The recorded scattering events are assigned to different time slices of the process and corresponding slices from all repetitions are summed up. The normalization of such data with respect to the incident beam spectrum can be challenging since the incident neutron flux may not necessarily be evenly distributed over all time slices. In this paper, we discuss how this can result in misleading information and we expand on a technique to amend these issues.
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| 8. |
- Adloff, C, et al.
(författare)
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Measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA
- 2002
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 542:3-4, s. 193-206
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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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| 9. |
- Adlmann, Franz A., et al.
(författare)
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Överlåtaren : a fast way to transfer and orthogonalize two-dimensional off-specular reflectivity data
- 2016
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Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 49, s. 2091-2099
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Tidskriftsartikel (refereegranskat)abstract
- Reflectivity measurements offer unique opportunities for the study of surfaces and interfaces, and specular reflectometry has become a standard tool in materials science to resolve structures normal to the surface of a thin film. Off-specular scattering, which probes lateral structures, is more difficult to analyse, because the Fourier space being probed is highly anisotropic and the scattering pattern is truncated by the interface. As a result, scattering patterns collected with (especially time-of-flight) neutron reflectometers are difficult to transform into reciprocal space for comparison with model calculations. A program package is presented for a generic two-dimensional transformation of reflectometry data into q space and back. The data are represented on an orthogonal grid, allowing cuts along directions relevant for theoretical modelling. This treatment includes background subtraction as well as a full characterization of the resolution function. The method is optimized for computational performance using repeatable operations and standardized instrument settings.
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| 10. |
- Adloff, C, et al.
(författare)
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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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