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| 2. |
- Erlingsson, Gissur Ó, 1974-
(författare)
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Mellankommunal samverkan - är det värt det? : En explorativ ansats
- 2022
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Ingår i: Statsvetenskaplig Tidskrift. - Lund, Sweden : Fahlbeckska Stiftelsen. - 0039-0747. ; 124:2, s. 493-509
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Tidskriftsartikel (refereegranskat)abstract
- Intermunicipal cooperation – is it worth it?As the case has been in several other countries, in Sweden, intermunicipal cooperation (IMC) has increased dramatically throughout the past three decades. Actors within the state as well as local government have had high expectations about what IMC may accomplish, ranging from increasing quality of services to lowering costs and facilitating recruitment of expertise. However, there is a dearth of evaluations done on whether IMC actually fulfills such promises in the Swedish context. Against this backdrop, we have conducted a survey directed to municipal managers in those 61 municipalities that have formalized cooperation in the area of planning, environment and supervision. Overall, positive experiences are reported: a vast majority perceive that quality of services increase and recruitment is facilitated. However, generally, they do generally not report that costs decrease, but do state that steering becomes more cumbersome with IMC. Considering that we employ a most likely-design, the relatively negative findings on costs, as well the observation that host municipalities report more positive experiences than non-host municipalities, our results are intriguing and highlight the need for deepened studies on these particular issues.
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| 3. |
- Folkesson, Anders
(författare)
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Växtbäddar för växter med speciella krav
- 2016
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Ingår i: Movium Fakta. - 2001-2357.
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Annan publikation (populärvet., debatt m.m.)abstract
- Växtbäddarna ses av många som en besvärlig del av markprojekteringen. Anläggnings-AMA tillhandahåller vissa ”standardlösningar”, såsom A-jord och B-jord, vilka ger bra hjälp och en trygghet i sammanhanget. Men hur gör man om man behöver skapa växtbäddar för växter som kräver något annat? I detta Movium Fakta sammanfattas budskap, inspiration och arbetsmetodik från den nyligen utgivna Jordkokboken, där Movium-rådgivaren Anders Folkesson propagerar för mer miljömässigt och ekonomiskt hållbara växtbäddslösningar.
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| 4. |
- Folkesson, Anders, et al.
(författare)
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Växter för vinterfägring
- 2015
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Ingår i: Movium Fakta. - 2001-2357.
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Annan publikation (populärvet., debatt m.m.)
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| 5. |
- Wikström, Martina, et al.
(författare)
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Analysis of the fuel economy improvement potential of ethanol hybrid buses
- 2011
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Ingår i: Proceedings of the 24th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2011. - : Nis University. - 9788660550165 ; , s. 2220-2229
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Konferensbidrag (refereegranskat)abstract
- With the ambitions to further increase its share of renewable fuels and to reduce the amount of carbon dioxide emissions, local emissions and noise, Stockholm Public Transport (SL) hosted a one-year project to evaluate the performance of ethanol hybrid buses. An important part of the project was the duty cycle tests according to SORT - Standardised On-Road Tests cycles (developed by the International Association of Public Transport, UITP). The duty cycle tests generated experimental data, on which this paper’s discussion is based upon. The purpose of this article is to evaluate the potential of energy-efficiency improving measures on the powertrain. The ethanol hybrid bus is a series hybrid vehicle with regenerative braking. A start/stop software to avoid idling was optional. A bus with similar exterior properties, but with the ethanol internal combustion engine coupled to a conventional automatic gearbox instead of a hybrid powertrain was used as a reference throughout the project. Based on both experimental data and simulations, several measures to increase the overall energy-efficiency may be proposed. Assessed measures to increase the energy-efficiency include size optimization of powertrain components, such as energy storage and electric motor, and internal combustion engine (identified by using Sankey diagrams), adjustment of the super capacitors energy management system and utilisation of engine start/stop functionality. Analysis shows that the size of the energy storage is well attuned if applied as urban transport. It would be possible to downsize the ICE, from approximately 200 kW to approximately 150 kW, without losing substantial performance. Using the start/stop software reduces the fuel consumption with 15 % in the standardized city duty cycle but has the potential for even further fuel economy improvements in real traffic with more idling.
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| 6. |
- Wikström, Martina, et al.
(författare)
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First experiences of ethanol hybrid buses operating in public transport
- 2011
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Konferensbidrag (refereegranskat)abstract
- With the ambitions to further increase its share of renewable fuels and to reduce the amount of local carbon dioxide emissions and noise, Stockholm Public Transport (SL), together with bus manufacturer Scania and bus operator Nobina, hosted a one year project to evaluate the performance of ethanol hybrid buses. Six ethanol hybrid buses were operating in regular public transport between June 2009 and June 2010. During this period the buses were operating at three different suburban routes. The purpose was to accumulate experimental data and to validate the robustness of the ethanol hybrid system and its components. In addition, in order to obtain comparable data, standardized duty cycle tests were performed. Furthermore, with the objective to assemble experimental data during heavy traffic and low mean velocity conditions, two urban routes were selected for staged tests with one ethanol hybrid bus.The purpose of this paper is to evaluate the energy efficiency of the electrified driveline and hybrid components of the Scania ethanol hybrid bus based on experimental data.The bus is a series hybrid vehicle with regenerative braking. A start/stop software to avoid idling was optional. The key components of a series hybrid are internal combustion engine, generator, energy storage, electric engine and resistor. The energy storage was commercially available super capacitors. The components of the electric powertrain were developed and delivered by Voith Turbo. A bus with identical exterior properties, an ethanol internal combustion engine coupled to a conventional automatic gearbox but without a hybrid system was used as a reference throughout the project. The measurement equipment was installed in the hybrid system to capture energy flows in and out of key components. Parallel logging of GPS coordinates generated a velocity profile which coupled with energy flow data constitute to the foundation of the analysis.The main results are presented as Sankey diagrams visualizing the energy flow through the electrified powertrain and determines the energy efficiency for each of the different traffic situations. The initial experimental results indicate that the reduction of fuel consumption benefits from routes with low mean velocity and a high number of stop. At such favorable conditions the fuel reduction are in the order of 30 %. The potential additional fuel savings of the start/stop software has been simulated and adds another 5-10 % fuel reduction. Not all of the hybrid system’s components are not yet robust enough and need further development. The super capacitors work consistent and are suitable as energy storage for this application.
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| 7. |
- Neuman, Magnus, et al.
(författare)
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Modelling and Control of Series HEVs Including Resistive Losses and Varying Engine Efficiency
- 2009
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Ingår i: Proceedings of SAE 2009 World Congress. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International.
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Konferensbidrag (refereegranskat)abstract
- A model of a series HEV (Hybrid Electric Vehicle) including resistive losses in the energy storage and varying engine and generator efficiency is presented. The purpose is to study how system properties affect the optimal control of series HEVs. We show that there is an inherent trade-off in the control of such a system, based on the characteristics of the efficiency curve of the EGU (Engine and Generator Unit) together with the energy storage internal resistance, capacitance and energy level. The relation between these properties determines the optimal control of the EGU, and this is thus the mechanism behind all optimal control problems using a similar model setup. We illustrate our reasoning using deterministic dynamic programming where system properties are varied and the optimal control is studied.
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| 8. |
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| 9. |
- Folkesson, Anders, 1976-
(författare)
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Towards sustainable urban transportation : Test, demonstration and development of fuel cell and hybrid-electric buses
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Several aspects make today’s transport system non-sustainable: • Production, transport and combustion of fossil fuels lead to global and local environmental problems. • Oil dependency in the transport sector may lead to economical and political instability. • Air pollution, noise, congestion and land-use may jeopardise public health and quality of life, especially in urban areas. In a sustainable urban transport system most trips are made with public transport because high convenience and comfort makes travelling with public transport attractive. In terms of emissions, including noise, the vehicles are environmentally sustainable, locally as well as globally. Vehicles are energy-efficient and the primary energy stems from renewable sources. Costs are reasonable for all involved, from passengers, bus operators and transport authorities to vehicle manufacturers. The system is thus commercially viable on its own merits. This thesis presents the results from three projects involving different concept buses, all with different powertrains. The first two projects included technical evaluations, including tests, of two different fuel cell buses. The third project focussed on development of a series hybrid-bus with internal combustion engine intended for production around 2010. The research on the fuel cell buses included evaluations of the energy efficiency improvement potential using energy mapping and vehicle simulations. Attitudes to hydrogen fuel cell buses among passengers, bus drivers and bus operators were investigated. Safety aspects of hydrogen as a vehicle fuel were analysed and the use of hydrogen compared to electrical energy storage were also investigated. One main conclusion is that a city bus should be considered as one energy system, because auxiliaries contribute largely to the energy use. Focussing only on the powertrain is not sufficient. The importance of mitigating losses far down an energy conversion chain is emphasised. The Scania hybrid fuel cell bus showed the long-term potential of fuel cells, advanced auxiliaries and hybrid-electric powertrains, but technologies applied in that bus are not yet viable in terms of cost or robustness over the service life of a bus. Results from the EU-project CUTE show that hydrogen fuelled fuel cell buses are viable for real-life operation. Successful operation and public acceptance show that focus on robustness and cost in vehicle design were key success factors, despite the resulting poor fuel economy. Hybrid-electric powertrains are feasible in stop-and-go city operation. Fuel consumption can be reduced, comfort improved, noise lowered and the main power source downsized and operated less dynamically. The potential for design improvements due to flexible component packaging is implemented in the Scania hybrid concept bus. This bus and the framework for its hybrid management system are discussed in this thesis. The development of buses for a more sustainable urban transport should be made in small steps to secure technical and economical realism, which both are needed to guarantee commercialisation and volume of production. This is needed for alternative products to have a significant influence. Hybrid buses with internal combustion engines running on renewable fuel is tomorrow’s technology, which paves the way for plug-in hybrid, battery electric and fuel cell hybrid vehicles the day after tomorrow.
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| 10. |
- Saxe, Maria, et al.
(författare)
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Energy system analysis of the fuel cell buses operated in the project: Clean Urban Transport for Europe
- 2008
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 33:5, s. 689-711
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Tidskriftsartikel (refereegranskat)abstract
- During the project Clean Urban Transport for Europe (CUTE), which ended in May 2006, 27 fuel cell buses were operated in nine European cities. In this paper key performance parameters from the operation of the fuel cell buses in the project are reported, the energy system of the bus is analysed and drive cycle tests in five cities are presented and analysed. The focus of the paper is on fuel consumption and optimisation potential but experiences of, and recommendations for, evaluation in large demonstration projects are also presented. The results show that although the total fuel cell system efficiency was found to be high (36–41%), the fuel consumption was higher for the fuel cell buses than for diesel buses. Since the CUTE buses were a pre-commercial generation of fuel cell buses, with standard auxiliaries and extensive reliability measures, large fuel consumption reduction is possible. Suggestions on how to increase the efficiency is presented in this paper. Minimising the reliability measures would decrease fuel consumption by about 20% and lowering the weight by 2 tonnes would decrease fuel consumption by another 10%. Hybridisation in combination with using electrical auxiliaries could save an additional 5–10% or more.
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