| 1. |
- 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
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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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| 2. |
- Fridell, Erik, 1963, et al.
(författare)
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Investigation of NOx storage catalysts
- 1997
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Ingår i: 4th International Congress on Catalysis and Automotive Pollution Control (CAPoC4) in Brussels, Belgium, April 9-11, 1997.
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Konferensbidrag (refereegranskat)
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| 3. |
- Fridell, Erik, 1963, et al.
(författare)
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Investigations of NOx storage catalysts
- 1998
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Ingår i: Studies in Surface Science and Catalysis. - 0167-2991. ; 116, s. 537-547
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Tidskriftsartikel (refereegranskat)abstract
- NOx storage catalysts are used to reduce nitrogen oxides from lean-burn vehicles. The nitrogen oxides are stored in the catalyst during lean conditions and subsequently released and reduced during short periods of rich conditions. In the present study, we systematically investigate the sequence of elementary steps in the NOx reduction cycle, and the extent to which these steps influence the maximum NOx, reduction potential of the catalyst. As a model system, we use barium oxide as the NOx, storing compound in a Pt/Rh/Al2O3 system. Kinetics of NO oxidation, NO and NO2 adsorption, NO and NO2 release and reduction are studied under controlled conditions with systematic variations of temperature, gas composition, and storing/release times. The transient experiments comprise a storing phase using a lean NO/C3H6/O2/N2 gas mixture, and a regenerating phase where the O2 now is turned off. Experimentally, a significant amount of NOx is found to be stored in the Ba-containing material. A maximum in NOx storage is observed around 380 degrees C. For most of the experiments, there are clear NO and NO2 desorption peaks upon switching from the storing to the regeneration phase. TPD studies of NO and NO2 reveal a significant difference between prereduced and pre-oxidised samples where the former produce predominantly N2 and N2O at around 200 degrees C while NO and O2 desorb from the latter around 500 degrees C. In situ FTIR spectra show nitrate peaks in the region 1300-1400 cm(-1) when NOx is stored under lean conditions.
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| 4. |
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| 5. |
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| 6. |
- Acke, Filip, 1968, et al.
(författare)
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Influence of the platinum-support interaction on the direct reduction of NOx under lean conditions
- 1998
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Ingår i: Studies in Surface Science and Catalysis. - 0167-2991. ; 116, s. 285-294
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Tidskriftsartikel (refereegranskat)abstract
- Catalysts containing Pt supported on SiC, Al2O3 and ZSM-5 were prepared and studied for NOx reduction by C3H6 in Oz excess under transient (temperature ramps) and steady-state conditions. The maximum NOx reduction activity in the heating ramp experiments was similar for Pt/SiC and Pt/ZSM-5, while Pt/Al2O3 showed higher maximum activity. Both N-2 and N2O formation was observed for all catalysts, although the respective amounts varied with the investigated system. Highest Nz selectivity was observed for Pt/Al2O3. When the NOx reduction activity was studied under steady-state conditions the activity of Pt/Al2O3 decreased substantially (mainly due to a loss in N-2 production). Pt/ZSM-5 became somewhat more selective towards Na production whereas the activity and selectivity of Pt/SiC remained at about the same values as far the heating ramp experiments. Adsorbed species on the surface of the different catalysts were investigated using in-situ FTIR in order to obtain information about the reaction mechanisms. The adsorption of species on Pt/SiC was negligible, while a number of absorption bands were observed for Pt/Al2O3 (N and C containing species, and -NCO) and Pt/ZSM-5 (HC).
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| 7. |
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| 8. |
- Antonsson, Stefan, et al.
(författare)
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Biomimetic synthesis of suberin for new biomaterials
- 2005
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Ingår i: Appita Annual Conference. ; , s. 561-564
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Konferensbidrag (refereegranskat)abstract
- Suberin is the biopolymer giving cork (oak bark) its hydrophobic and resistant characteristics. It acts as a diffusion barrier in bark and roots of plants. Similarly to lignin, it is a phenolic polymer with good affinity to cellulose and other wood polysaccharides, but it also contains polyaliphatic and strongly hydrophobic elements. In order to produce a lignin derivative similar to suberin, a desired lignin starting material should be of low molecular weight and have a high content of hydroxylic phenolic groups. By means of cross flow nanofiltration of softwood kraft pulping black liquor and pH-precipitation with diluted sulphuric acid, such a lignin has been obtained. Due to the fact that too much organics entering the recovery boiler frequently is the bottleneck for pulp production increases, a removal of part of the lignin can be economically very favourable. By using this lignin together with linola oil, a linseed oil with a large amount of unsaturated structures, an attempt was made to create a new hydrophobic lignin derivative similar tosuberin. The product was analysed with FT-IR, Fourier Transformed Infra Red Spectroscopy and GPC, Gel Permeation Chromatography. The suberin like material obtained from this lignin could be polymerised on thermo mechanical pulp fibres by means of Mn(III)-driven phenolic coupling. The ability of the suberin monomers to act as a hydrophobic paper coating was evaluated with contact angle measurements and the results indicate that this lignin derivative was potentially of interest due to its capability to interact well with wood fibres and make paper hydrophobic.
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| 9. |
- Bosch-Sijtsema, Petra, 1971, et al.
(författare)
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Kvalitet & Digitala Modeller: Integrerad kvalitetssäkring & automatiserade kvalitetskontroller i komplexa projekt
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det finns stora effekter att vinna med digitalisering och BIM kopplat till projekterings- och byggprocessen. Att enkelt kunna identifiera och kontrollera att krav är uppfyllda är av stor vikt i multidisciplinära bygg- och anläggningsprojekt som ofta är komplexa och har många osäkerheter. Här anses BIM vara användbart för att bland annat förbättra kvaliteten genom att eliminera konflikter och minska omarbetningen. En styrd, kvalitetssäkrad och effektiv hantering av information om anläggningen kan rätt hanterat bland annat lämna ett ökat utrymme för innovation. Detta projekt presenterar en kartläggning över hur kvalitetssäkringsprocessen och kvalitetskontrollen genomförs idag och testar möjliga kvalitetskontroller. Genom att få en tydlig bild av hur kvalitetskontroller genomförs ges en inblick i de öar av kvalitetssäkringsprocessen som är generiska och vilka moment som kan automatiseras, vilket underlättar för alla aktörer och frigör tid för teknisk lösningsorienterade arbetsuppgifter och utveckling. Syftet med forskningsprojektet har varit att utveckla och testa kvalitetskontroller för kravuppfyllnad och kvalitetssäkring samt beslutsfattande kopplat till användande av digitala modeller. Projektet har genomförs baserat på ett Design Science angreppssätt vilket tar sin utgångspunkt i att både tekniska och mänskliga aspekter kopplas till det problem som ska lösas. Projektet uppdelades i 7 arbetspaket och är ett samarbete mellan Trafikverket, Chalmers, Trimble, Norconsult och Sweco. Del 1 i rapporten är en kartläggning av nuvarande process för leveranser, kvalitetssäkring och kravhantering inom projekteringsfasen, både hos Trafikverket och leverantör. Kartläggningen ger insyn i möjliga förbättringar och effektiviseringsvinster inom kvalitetssäkringsprocessen. Sammanfattningsvis visar kartläggningen att det behövs ett större fokus på de olika aktiviteterna som ingår i kvalitetsarbetet inom projekt. Del 2 i rapporten lyfter upp flera goda exempel och best-practices när det gäller automatiska kvalitetskontroller inom husbyggnad och menar att samma koncept för automatiska kvalitetskontroller går att använda inom anläggningsbranschen. Det finns extremt stor potential med automatiserade kvalitetskontroller (visuella, regelbaserade, automatiska och maskinläsbara) inom anläggningsprojekt och detta projekt har visat att det faktiskt fungerar och att det går att börja implementera vissa kontroller för digitala anläggningsmodeller redan nu. Dessa kontroller sparar tid och möjliggör att kontrollerna verkligen blir utförda. Dessutom kan dessa automatiska kvalitetskontroller frigöra tid som istället kan användas för att ta fram bättre tekniska lösningar och utformningar för projektet. Del 3 i rapporten tar upp en diskussion om kvalitetssäkring och digitala och/eller automatiserade kontroller. Utifrån innehåll i rapporten samlas här också ett antal rekommendationer relaterade till organisation, process och teknik/produkt. Rapporten tar upp att man för automatiserad kontroll av kravuppfyllnad vid leverander behövs ett modellorienterat integrerat arbetssätt för kontroll av lösning, en implementerad process för kvalitetssäkring av produktleveranser, ett modellbaserat gränssnitt för hantering av synpunkter och ändringar och en succeessiv uppföljning av projekt med en tillgänglig realtidsuppdaterad digital modell.
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| 10. |
- Chirumalla, Koteshwar, Associate Professor, et al.
(författare)
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Circular Business Models for the Electric Vehicle Battery Second Life : Navigating Battery Ecosystem Actors Towards Circularity
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The electrification of vehicles has become a critical means to achieve climate-neutral transportation. As more electric vehicles (EV) are adopted, an increasing number of lithiumion batteries will be utilized, inevitably experiencing capacity degradation over time. Retaining the value of these retired batteries through remanufacturing, reusing, and repurposing to create a second life holds significant environmental and economic benefits. However, many companies within the battery ecosystem struggle to capitalize on this opportunity due to a lack of business insight and suitable business models tailored to their operational contexts.The ReCreate (Second Life Management of Electric Vehicle Batteries) research project was initiated to address these industrial needs through close collaboration with selected companies in the battery ecosystem. The project aims to define appropriate circular business models, methods, and processes to guide battery ecosystem actors in developing and implementing electric vehicle battery second life solutions, thereby advancing circularity around batteries and climate-neutral objectives. This handbook represents the culmination of three years of research within the ReCreate project. Its purpose is to present a simplified and practical overview of project outcomes across a series of key chapters. Comprising six chapters, the handbook will begin by discussing barriers and enablers, followed by circular business models and battery ecosystem management. It will then delve into design principles and performance monitoring guidelines, concluding with an integrated framework for second life and circular solutions for EV batteries. Each chapter briefly presents the main findings of the theme and concludes with discussion questions. The discussion questions include suggestions for relevant templates for workshops, and all templates are conveniently provided in the appendix for practical application. These templates serve as boundary objects, offering a starting point for internal and external cross-functional and cross-organizational dialogues within the electric vehicle battery ecosystem. They facilitate discussions and collaborations among various stakeholders, fostering alignment and synergy in developing circular business models for the second life of EV batteries. By facilitating reflection on current business strategies, needs, and pain points, the handbook aims to aid in the definition of future second life business strategies. We anticipate that this handbook will serve as a valuable resource for actors within the EV battery ecosystem, supporting their journey towards climate-neutral transportation.
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| 11. |
- Fridell, Erik, 1963, et al.
(författare)
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NOx storage in barium-containing catalysts
- 1999
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 0021-9517 .- 1090-2694. ; 183:2, s. 196-209
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Tidskriftsartikel (refereegranskat)abstract
- The effect of key parameters on the characteristics of barium oxide-based NOx storage catalysts was systematically investigated. Model Pt/BaO/Al2O3, BaO/Al2O3, Pt–Rh/Al2O3, and Pt–Rh/BaO/Al2O3 catalysts were prepared and evaluated with respect to NOx storage capacity using transient flow reactor studies, temperature-programmed desorption studies (TPD), and in situ Fourier transform infrared (FTIR) absorption spectroscopy. The influence of temperature, storage and regeneration times, NOx source (NO or NO2), oxygen concentration, reducing agent (C3H6, C3H8, CO, or H2), and carbon dioxide concentration onNOx storage capacity was studied. Significant amounts of NOx were found to be stored in the catalysts containing both barium oxide and noble metals. For these catalysts the following observations were made: (1) maximum NOx storage was observed at about 380C;(2) around this temperature no significant differences between NO and NO2 on NOx storage capacity could be observed;(3) a slow increase in stored NOx could be observed with increasing oxygen concentration during the lean phase;(4) significant NOx desorption peaks, mainly of NO, were observed immediately after the switch from lean to rich conditions; and (5) at about 380±C the in situ FTIR spectra show characteristic nitrate peaks in the region 1300–1400 cm¡1 when NOx was stored under lean conditions and isocyanate peaks around 2230 cm-1 when the catalysts were regenerated under rich conditions in the presence of hydrocarbons. The step leading to stored NOx is believed to involve NO2 and the presence of atomic oxygen. During the rich period, the noble metal surfaces are probably reduced, leading to breakthrough peaks when NO desorbs.
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| 12. |
- 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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| 13. |
- Johansson, Håkan T, 1977, et al.
(författare)
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GGLAND - command line simulations
- 2014
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Ingår i: GSI Scientific Report 2013. - 0171-4546. ; 2014-1, s. 154-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 14. |
- Johansson, Stefan, 1967
(författare)
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Micro-Flow Reactors for Kinetic Studies of Model Catalysts made by Electron-Beam Lithography
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this work is to explore the potential of using electron beam lithography (EBL) to prepare well defined supported model catalysts, which can be used for catalytic research. The work has involved three major areas (i) EBL-fabrication of catalysts, (ii) design of a micro-flow reactor for catalytic evaluation, and (iii) problem oriented research using EBL-fabricated model catalysts. With the EBL technique supported model catalysts have been prepared consisting of arrays of Pt particles on SiO2 and CeOx. To evaluate the catalytic performance of the EBL fabricated model catalysts, a specially designed low-flow micro reactor has been constructed. The main feature is a very low flow through the reactor (approx. 1 microliter/second ) to match the small overall precious metal surface area presently attainable with the EBL technique (on the order of 1 mm2) for small particle sizes (
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| 15. |
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Johansson, Wilhelm, et al.
(författare)
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Transparent TiO2 and ZnO Thin Films on Glass for UV Protection of PV Modules
- 2020
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Ingår i: American Ceramic Society Bulletin. - : American Ceramic Society Inc.. - 0002-7812 .- 1945-2705. ; 99:4, s. 26-29
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- To stabilize the global temperature and mitigate climate change, the emission of anthropogenic greenhouse gases will have to be greatly reduced. To make it possible, the energy sector will have to transfer from fossil energy to environmentally friendly and carbon neutral sources.
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| 20. |
- Johansson, Wilhelm, et al.
(författare)
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Transparent TiO2 and ZnO Thin Films on Glass for UV Protection of PV Modules
- 2019
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Ingår i: Frontiers in Materials. - Lausanne, Switzerland : Frontiers Media S.A.. - 2296-8016. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Failure of PV modules frequently occurs as a result of degradation of their encapsulation material by destructive UV radiation. Both the life expectancy and efficiency of PV modules can be improved by reducing the transmittance of the destructive UV radiation through the cover glass without compromising the transmittance in the visible wavelength region. In addition, if the absorbed UV photons can be down-shifted to wavelengths that can be more efficiently converted to electrical energy, an additional increase of the PV efficiency could be achieved. In this study we have investigated transparent ZnO and TiO2 thin films deposited by spray pyrolysis on soda lime silicate float glass as functional layers on PV cover glass. The optical bandgap, UV-cutoff, UV-Vis transmittance, reflectivity (total and diffuse) and photoluminescence have been determined. The ZnO coating shifted the optical bandgap to longer wavelengths, resulting in a reduction of the transmittance of destructive UV radiation by up to ∼85%. Distinct photoluminescence peaks at 377 nm and at 640 nm were observed for one of the ZnO samples. The TiO2 coated glasses also showed an increased UV cutoff, which resulted in a reduction of transmittance of destructive UV radiation by up to 75%. However, no photoluminescence peaks could be observed from the TiO2 films with 325 nm excitation laser, which can be explained by the fact that only indirect interband transitions are accessible at this excitation wavelength. Deposition of both ZnO and TiO2 coatings resulted in a reduction of the transmitted light convertible by PV modules, by up to 12.3 and 21.8%, respectively. The implication of the results is discussed in terms of lifetime expectancy and efficiency of PV modules.
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| 21. |
- Jormfeldt, Johanna, 1967-
(författare)
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Skoldemokratins fördolda jämställdhetsproblem : Eleverfarenheter i en könssegregerad gymnasieskola
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The general question in this dissertation is whether the democracy of schools is carried out in a gender equal manner in Sweden’s gender segregated upper secondary school. Students’ experiences of school democracy are measured using the dimensions of influence, discussion and legal rights. Three different explanatory factors are considered: the significance of gender, gender context and the character of the school programmes for these experiences.The study is based on student responses to a poll conducted in the top form classes of Kronoberg County’s upper secondary schools during the school year 2008/2009. The results of a series of regression analyses show that neither gender, gender context or programme character alone had an affect on experiences of school democracy. However, the more males present in a teaching environment, the poorer the experiences of influence and discussion are when all of the three explanatory factors are controlled for. In addition, the school programmes having male-coded character content particularly stand out favourably regarding school democracy. The number of males is usually high in such programmes and therefore the negative effects of male representation cancel out the positive effects of programme affiliation unless an explicit division is made of both of these aspects. Thus, keeping gender context and programme character separate is very important with studies of school democracy, since significant effects otherwise remain hidden.The study demonstrates that school democracy is important for students. Those students who have good experiences of school democracy perceive the school environment as significantly better than those who have poor experiences of school democracy. Concerning secondary effects, it appears that experiences of school democracy have different implications for learning among female and male students. There is a negative relationship between male experiences of influence and their grades in Swedish and Maths, while female experiences of discussion seem to show a positive covariance with grades. There is no relationship found in the data between students’ daily experiences of school democracy and their thoughts on voting in the upcoming parliamentary election.
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| 22. |
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| 23. |
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| 24. |
- Sterner, Thomas, 1952, et al.
(författare)
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Funding Inclusive Green Transition through Greenhouse Gas Pricing : Carbon Pricing
- 2020
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Ingår i: ifo DICE Report. - 2511-7815. ; 18:1, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- 2015 was a special year. During a few months the political stars aligned and made it possible for the international community to agree on the Agenda 2030 for Sustainable Development and the Paris Agreement to limit global warming. Now the signatories need to find ways to implement these agreements, which not only imply a deep decarbonization of the economy but must also meet the Sustainable Development Goals. In this article we discuss the importance of pricing greenhouse gas (GHG) emissions2 to make this happen. Climate abatement is a truly global public good and so we actually have to have a functioning policy in all countries. Our interest is thus on pricing in all countries but in particular the developing countries that are bigger and most crucial to the struggle for a green transition.
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| 25. |
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| 26. |
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