| 1. |
- Calles, Britt-Marie, et al.
(author)
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Grunddatadomän transportsystem: Kompletterande underlag till den utforskande förstudien
- 2022
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Reports (other academic/artistic)abstract
- I mars 2022 levererade Trafikverket och samverkande myndigheter (Transportstyrelsen, Sjöfartsverket, Luftfartsverket, Trafikanalys och VTI, Statens väg- och transportforskningsinstitut) en rapport som sammanfattade den utforskande utvecklingen att utreda en grunddatadomän för transportsystemet. Föreliggande rapport är en komplettering till den ursprungliga rapporten och utgör Trafikverkets inklusive samverkande myndigheters sammantagna underlag (utforskande utveckling) för etablering av en grunddatadomän för transportsystemet. Arbetet har bedrivits under ledning av Myndigheten för digital förvaltning (DIGG) med Trafikverket som ansvarig för den utforskande utvecklingen. Till rapporten hör en bilaga, se länk till höger.Ursprunglig rapport: Grunddatadomän transportsystem: Samverkansuppdrag mellan transportmyndigheterna för att bedriva en utforskande utveckling att utreda en grunddatadomän för information kopplat till transportsystemet
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| 2. |
- Aramrattana, Maytheewat, 1988-, et al.
(author)
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A Novel Risk Indicator for Cut-In Situations
- 2020
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In: 2020 IEEE 23rd International Conference on Intelligent Transportation Systems, ITSC 2020. - Piscataway, NJ : Institute of Electrical and Electronics Engineers Inc.. - 9781728141497 - 9781728141503
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Conference paper (peer-reviewed)abstract
- Cut-in situations occurs when a vehicle intentionally changes lane and ends up in front of another vehicle or in-between two vehicles. In such situations, having a method to indicate the collision risk prior to making the cut-in maneuver could potentially reduce the number of sideswipe and rear end collisions caused by the cut-in maneuvers. This paper propose a new risk indicator, namely cut-in risk indicator (CRI), as a way to indicate and potentially foresee collision risks in cut-in situations. As an example use case, we applied CRI on data from a driving simulation experiment involving a manually driven vehicle and an automated platoon in a highway merging situation. We then compared the results with time-to-collision (TTC), and suggest that CRI could correctly indicate collision risks in a more effective way. CRI can be computed on all vehicles involved in the cut-in situations, not only for the vehicle that is cutting in. Making it possible for other vehicles to estimate the collision risk, for example if a cut-in from another vehicle occurs, the surrounding vehicles could be warned and have the possibility to react in order to potentially avoid or mitigate accidents.
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| 3. |
- Aramrattana, Maytheewat, et al.
(author)
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A Simulation Study on Effects of Platooning Gaps on Drivers of Conventional Vehicles in Highway Merging Situations
- 2021
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In: IEEE transactions on intelligent transportation systems (Print). - Piscataway, NJ : Institute of Electrical and Electronics Engineers Inc.. - 1524-9050 .- 1558-0016.
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Journal article (peer-reviewed)abstract
- Platooning refers to a group of vehicles that--enabled by wireless vehicle-to-vehicle (V2V) communication and vehicle automation--drives with short inter-vehicular distances. Before its deployment on public roads, several challenging traffic situations need to be handled. Among the challenges are cut-in situations, where a conventional vehicle--a vehicle that has no automation or V2V communication--changes lane and ends up between vehicles in a platoon. This paper presents results from a simulation study of a scenario, where a conventional vehicle, approaching from an on-ramp, merges into a platoon of five cars on a highway. We created the scenario with four platooning gaps: 15, 22.5, 30, and 42.5 meters. During the study, the conventional vehicle was driven by 37 test persons, who experienced all the platooning gaps using a driving simulator. The participants' opinions towards safety, comfort, and ease of driving between the platoon in each gap setting were also collected through a questionnaire. The results suggest that a 15-meter gap prevents most participants from cutting in, while causing potentially dangerous maneuvers and collisions when cut-in occurs. A platooning gap of at least 30 meters yield positive opinions from the participants, and facilitating more smooth cut-in maneuvers while less collisions were observed.
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| 4. |
- Auvray, Xavier, 1986, et al.
(author)
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Comparative Study of SO 2 and SO 2 /SO 3 Poisoning and Regeneration of Cu/BEA and Cu/SSZ-13 for NH 3 SCR
- 2021
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In: Emission Control Science and Technology. - : Springer Science and Business Media LLC. - 2199-3629 .- 2199-3637. ; 7:4, s. 232-246
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Journal article (peer-reviewed)abstract
- Two copper-exchanged zeolites, Cu/SSZ-13 and Cu/BEA, were studied as catalysts for the selective reduction of NOx by NH3 (NH3-SCR). Their activities for standard SCR (NOx = NO) and fast SCR (NOx = 50% NO + 50% NO2) were measured before and after sulfur poisoning at 250 °C. The effect of 30 ppm SO2 and a mixture of 24 ppm SO3 + 6 ppm SO2 was evaluated. The repetition of subsequent activity measurements served as regeneration method in SCR conditions. SO2 deactivated Cu/SSZ-13 whereas Cu/BEA was only moderately affected. SO3 led to stronger deactivation of both catalysts than SO2. However, also for this case, the Cu/BEA was significantly less affected than Cu/SSZ-13, even though Cu/BEA contained larger amount of stored sulfur. One possible reason for this could be the large pores of Cu/BEA, where the sulfur species possibly resulted in less sterical hindrance than in the small pore SSZ-13 structure. NH3 temperature-programmed desorption (NH3-TPD) showed no loss of storage sites upon sulfur treatment and subsequent regeneration. Partial activity recovery was observed after a period in SCR conditions at 400 °C and 500 °C. Temperature at 300 °C was insufficient to regenerate the catalysts. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of NO adsorption suggested that SO2 interacts with the ZCuOH sites on Cu/SSZ-13, causing the strong poisoning.
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| 5. |
- Feng, Yingxin, 1994, et al.
(author)
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A First-Principles Microkinetic Model for Low-Temperature NH3 Assisted Selective Catalytic Reduction of NO over Cu-CHA
- 2021
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In: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 11:23, s. 14395-14407
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Journal article (peer-reviewed)abstract
- A first-principles microkinetic model is developed to investigate low-temperature ammonia assisted selective catalytic reduction (NH3-SCR) of NO over Cu-CHA. The reaction proceeds over NH3-solvated Cu-sites by the formation of H2NNO and HONO, which decompose to N2 and H2O over Brønsted acid sites. Non-selective N2O formation is considered by H2NNO decomposition over the Cu-sites. The adsorption of NH3 at oxidized Cu-sites is found to inhibit the reaction at low temperatures by hindering NO adsorption. For the reactions, we nd positive reaction orders with respect to NO and O2, whereas the reaction order with respect to NH3, is negative. The reaction orders and the obtained apparent activation energy are in good agreement with experimental data. A degree of rate control analysis shows that NH3-SCR over a pair of Cu(NH3)+2 is mainly controlled by NO adsorption below 200 C, whereas the formation of HONO and H2NNO becomes controlling at higher temperatures. The successful formulation of a first-principles microkinetic model for NH3-SCR rationalizes previous phenomenological models and links the kinetic behaviour with materials properties, which results in unprecedented insights in the function of Cu-CHA catalysts for NH3-SCR.
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| 6. |
- Feng, Yingxin, 1994, et al.
(author)
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High-Temperature Reaction Mechanism of NH 3 -SCR over Cu-CHA: One or Two Copper Ions?
- 2024
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In: Journal of Physical Chemistry C. - 1932-7447 .- 1932-7455. ; 128:16, s. 6689-6701
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Journal article (peer-reviewed)abstract
- Cu-exchanged chabazite (Cu-CHA) shows good performance for selective catalytic reduction of nitrogen oxides using NH3 as a reducing agent (NH3-SCR). The temperature dependence of the activity has a characteristic nonmonotonic behavior with a minimum in the range 300-350 °C. The minimum signals that different reaction mechanisms or active sites dominate at low and high temperatures. The low-temperature mechanism is believed to occur over a pair of mobile [Cu(NH3)2]+ complexes, whereas the high-temperature mechanism should proceed over framework-bound Cu ions. To explore the NH3-SCR reaction over framework-bound Cu ions, we use first-principles calculations combined with mean-field microkinetic simulations. We find that the reaction proceeds over a single framework-bound Cu ion and that the first step is NO and O2 coadsorption. The coadsorption competes with NH3 adsorption, and the NH3-SCR rate is largely determined by the adsorption energy of NH3. Combining the high-temperature kinetic model with our previous low-temperature model for NH3-SCR over pairs of mobile [Cu(NH3)2]+ complexes makes it possible to describe the nonmonotonic behavior of the reaction rate. The work provides a detailed mechanistic understanding of the role and transformation of different forms of Cu ions during low- and high-temperature standard SCR in Cu-CHA.
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| 7. |
- Feng, Yingxin, 1994, et al.
(author)
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The Role of H+- and Cu+-Sites for N2O Formation during NH3-SCR over Cu-CHA
- 2021
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In: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 125:8, s. 4595-4601
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Journal article (peer-reviewed)abstract
- The mechanism for N2O formation over CHA and Cu-CHA zeolite catalysts during NH3-SCR is investigated using density functional theory calculations. Direct NH4NO3 decomposition, which is commonly regarded as the main source of N2O, is found to be associated with high barriers in the absence of Brønsted acid sites. Although Brønsted acid sites promote NH4NO3 decomposition, it is still a highly activated process. Low-temperature N2O formation is instead found to be connected with an NO + NH3 reaction over Cu-sites. In particular, N2O can be formed from H2NNO with a low barrier over Cu-OOH-Cu complexes, which are proposed intermediates in the catalytic cycle for NH3-SCR over Cu-CHA. This finding provides an explanation for the experimentally observed low-temperature N2O formation and the relation between Cu loading and N2O formation. The proposed mechanisms open up strategies to enhance the selectivity to N2 during NH3-SCR.
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| 8. |
- Forsman, Åsa, 1972-, et al.
(author)
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Riding in a safe system – workshop on safety for powered-two-wheelers : final report from a workshop held on 9–13 June 2021
- 2021
-
Reports (other academic/artistic)abstract
- An international workshop on safety for powered-two-wheelers (PTWs), Riding in a safe system, was held as a series of virtual meetings 9–23 June 2021. The workshop was co-organised by the International Transport Forum (ITF), the Swedish Transport Administration, the International Motorcycling Federation (FIM), the motorcycle manufacturers associations (IMMA and ACEM), and the Swedish National Road and Transport Research Institute (VTI). The workshop was a follow-up of the Third Global Ministerial Conference on Road Safety, held in Stockholm in February 2020, but it also built on a previous workshop in 2008 in Lillehammer and the 2015 ITF research report “Improving Safety for Motorcycle, Scooter and Moped Riders”. The workshop, which included six expert sessions, focused on seven different areas: (i) Sustainable practices, work-related issues and procurement, (ii) Modal shift and urban needs, (iii) Training, education, and licensing, (iv) Vehicle safety, protective safety, and Intelligent Transport Systems, (v) Road infrastructure and road environment, (vi) Speed management, adapting speeds and behaviour to different environments, (vii) Youth and child safety. Eight priority actions were recognized by the workshop to achieve the integration of PTWs in the safe system by 2030. These actions build on the Stockholm declaration and its 9 recommendations. The actions are generalized results from the outcome of the expert sessions. The 8 priority actions from the workshop are: (i) Move to sustainable practice, (ii) Support modal shift, (iii) Adopt safe vehicles and equipment, (iv) Educate safe riders, (v) Redesign infrastructure, (vi) Ensure safe speed, (vii) Protect children, and (viii) increase knowledge.
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| 9. |
- Jansson, Jonas, 1973-, et al.
(author)
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National data governance in the transport sector : an international outlook and literature review
- 2022
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Reports (other academic/artistic)abstract
- This report aims to provide background information on national efforts to establish and govern data within the transport area. The purpose is to support the work of establishing a national data domain for the transport sector in Sweden. The focus of the current work has been on transport data, governance of transport data and in particular emphasizing national datasets and national data governance initiatives. To find information about this a dual approach was used. Firstly, we have looked for scientific publications in bibliographic databases. Secondly, a request for information within the existing networks of VTI was sent out, this includes both other research providers and authorities across the world. The literature found and the replies from the international outreach are very consistent in the need and potential of handling data more efficiently. Most actors describe the need for making data accessible in a consistent way, both to facilitate new applications and to be more efficient in current practices. In the scientific literature there are very few if any initiatives that can be directly compared with the Swedish effort to establish a transport data domain on a national level (e.g., Grunddatadomän Transport). Furthermore, there is not much work that quantifies, in monetary values, the cost and benefits of establishing and maintaining data.
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| 10. |
- Jansson, Johan, 1973-, et al.
(author)
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Perspectives on sustainability in Sweden : stuck between two paradigms?
- 2020
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In: The future of the North - sustainability in Nordic countries. - Marburg : Metropolis Verlag für Ökonomie, Gesellscahft und Politik GmbH. - 9783731613640 ; , s. 167-216
-
Book chapter (peer-reviewed)abstract
- In this chapter we take a look at some, primarily, environmental sustainability issues in Sweden. Sweden is in many aspects a rich country with high social and economic welfare and it usually comes out as a country that has handled environmental challenges well. However, from a consumption perspective, Swedish consumers are among the world leaders when it comes to metrics such as ecological footprint and carbon dioxide emissions per capita. By using two paradigmatic views, the Dominant Social Paradigm (DSP) and the New Ecological Paradigm (NEP) we analyze sustainability in Sweden with a particular focus on energy use. We look at sustainability in the three broad areas of policies, corporate activities and consumption and in these areas we delve deeper into environmental sustainability issues concerning recycling and waste, energy efficiency, circular business models, sustainable consumer behaviors in relation to cars and transport, and responsible investments. We end the chapter by discussing implications for the future and the analytical framework and by developing a middle ground which we call ambiguous wavering.
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