Change search
Refine search result
2345 201 - 208 of 208
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 201.
    Tschan, Georg F.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Invasiva arter och transportinfrastruktur: en internationell kunskapsöversikt med fokus på vägar och växter2018Report (Other academic)
    Abstract [en]

    With the introduction of a new EU regulation in 2015 all member states have to take action against invasive alien species (IAS). Since the transport sector contributes heavily to IAS spread and establishment, it needs dedicated research and action plans. This report reviews the international literature on IAS within transport-related environments, identifies national research needs in Sweden and recommends strategies for successful countermeasures against IAS. The basic terminology and principles of invasion biology are explained, followed by an extensive review of dispersal via terrestrial transportation networks. Motor vehicles were found to be a significant contributor to long-distance dispersal and the spread of alien and invasive species. However, widely varying methods, scope and study localities of previously published studies make direct comparisons difficult. New, empirical and more systematic studies are needed to investigate the spread of IAS via the transportation network. To illustrate the need for an individual evaluation, three example species are presented in detail (Heracleum mantegazzianum, Lupinus polyphyllus, Ambrosia artemisiifolia), and other problematic groups are discussed. Available tools and information systems that can be used for documentation and control are presented. It is imperative that alien and not only already invasive species are considered. Furthermore, a national blacklist should be created which is regularly updated, and the inclusion of specialists as well as the general public is needed to counteract the negative consequences of IAS.

  • 202.
    Vieira, Tiago
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sandberg, Ulf
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Acoustical performance of winter tyres on two in-service road surfaces: A frequency spectrum analysis and comparison2017In: INTER-NOISE 2017 - 46th International Congress and Exposition on Noise Control Engineering: Taming Noise and Moving Quiet, Institute of Noise Control Engineering , 2017Conference paper (Refereed)
    Abstract [en]

    In order to provide appropriate performance on potentially hazardous winter or icy road surfaces, it is common to employ specific tyres developed for such conditions. Such winter tyres may contain studs embedded in the tyre tread, or they may be studless. Additionally, it is possible to use so called all season tyres which are also fitted for winter conditions. In some northern countries, the usage of winter tyres is mandatory and it is commonly assumed that studded winter tyres are significantly noisier than non-studded tyres. This paper analyses noise measurements on various types of winter tyres, both studded and studless, and the results are compared to all season and summer tyres. The measurements were carried out with the CPX method to characterize the noise performance of different tyres on in-service road surfaces. A total of approximately 50 light vehicle tyres were tested on two different road surfaces, namely an SMA 8 and a DAC 16. The analysis is focused on comparing different frequency spectra for each tyre category, providing a better understanding on how the presence of studs changes the resulting tyre/road noise in different frequencies and how winter tyres compare to all season and summer tyres regarding their frequency spectra. The results indicate how substantially the studs increase the noise level and drastically change the tyre acoustical behaviour at higher frequencies. The frequency spectra for studded tyres presented in this paper have a substantially different shape when compared to the spectra for studless tyres. The most characteristic difference between studded and non-studded tyres appears at frequencies above 4 kHz and is a result of the studs interacting with the road surface.

  • 203.
    Vieira, Tiago
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sandberg, Ulf
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Spectral analysis of the acoustical performance of winter tires for different road textures, test speeds and tire state-of-wear2018In: INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, Institute of Noise Control Engineering , 2018Conference paper (Refereed)
    Abstract [en]

    Under winter conditions, in which ice or snow may be present on the road, different tire designs may be used to provide suitable friction levels. One alternative is to have studs embedded in the tire tread to increase friction. Another alternative is to use a studless tire with materials and tread pattern optimized for winter conditions. There is also a hybrid alternative, which is the use of small hard particles instead of regular studs. When considering the acoustical performance, these three different alternatives have different properties; especially, the studded tires behave substantially different. Results from CPX measurements at different speeds and different road sections indicated that the studded tires spectral response is different in two major aspects: (i) a plateau instead of a decreasing trend is found for frequencies higher than 4 kHz, and (ii) overall increased noise levels, resulting in a spectrum that is shifted upwards. This paper analyses how the frequency spectra of winter tires are affected by different road surfaces, test speeds and tire wear. It also attempts to relate the observed behaviour to different contact and noise generation mechanisms to provide a better understanding of the acoustical performance of such tires.

  • 204.
    Vieira, Tiago
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sandberg, Ulf
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Acoustical performance of winter tyres on in-service road surfaces2019In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 153, p. 30-47Article in journal (Refereed)
    Abstract [en]

    Exposure to excessively high noise levels is a relevant health problem in Europe and road traffic noise is the most widespread noise source. When considering cold climate countries, the available scientific literature on noise emission properties of winter tyres is still very limited. In order to contribute into filling this knowledge gap, this paper investigates the acoustical performance of different types of tyres, with focus on winter tyres, on different road surfaces, at different speeds, and with different states of wear. The results indicate that studded winter tyres have, indeed, an increased noise level at frequencies between 315 Hz and 10 kHz, having a significantly different response especially at frequencies higher than 4 kHz. The acoustical response also depends on the tyre type when comparing different road surfaces, as a result of conflicting vibrational and aerodynamic noise generation mechanisms. Additionally, the relationship between labelled and measured values was explored, however, no statistically significant relationship was found between them (and labelling is not applied for studded tyres). A frequency spectrum correction was attempted based on previous measurements on an ISO track, which reduced the difference between measured and labelled values, however, further investigation is still required to properly understand differences between label and road measurements, where the label is determined on a test track with a special, smooth surface.

  • 205.
    Vieira, Tiago
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sandberg, Ulf
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Negative texture, positive for the environment: effects of horizontal grinding of asphalt pavements2019In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402Article in journal (Refereed)
    Abstract [en]

    A pavement surface having deflections from a plane mostly directed downwards in valleys is said to have a “negative texture”, in contrast to a “positive texture” dominated by peaks. Negative textures are typical of porous asphalt pavements, but another way to achieve this feature is to grind off the peaks of the surface. This paper explores the effects of grinding off texture peaks in the horizontal plane on a number of Swedish asphalt pavements in order to reduce noise and rolling resistance. Noise measurements were made to evaluate the ground-off surfaces versus the original surfaces, and, in most cases, also rolling resistance, texture and friction were also evaluated. It was found that grinding led to a more negative texture, tyre/road noise reductions up to 3 dB and tyre/road rolling resistance reductions up to 15%. It is concluded that horizontal grinding provides a maintenance operation with a significant potential for reduction of noise and rolling resistance, without sacrificing friction, though with limited longevity.

  • 206.
    Vierth, Inge
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Ahlberg, Joakim
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Carlson, Annelie
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Landergren, Magnus
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Swärdh, Jan-Erik
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Wikberg, Åsa
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics, TEK.
    Elanvändning för längre och tyngre tåg: sammanfattning av resultat, erfarenheter och lärdomar från ELVIS-demonstrationsprojekt2015Report (Other academic)
    Abstract [en]

    The ELVIS demonstration project aims to analyze how rail freight transports can be performed more efficiently. Hypotheses are that the transport efficiency can be improved by using longer and heavier freight trains and by implementing energy-related measures, and that there may be additional benefits for the companies and the society such as better utilization of the track capacity. This report summarizes the results and experiences from the three previously produced sub reports. In terms of both energy efficiency and overall efficiency for the rail transports researchers, companies and the Transport Administration concluded that there is a big need to secure the quality of the data that is produced. This applies to information about electricity consumption and the factors that possibly affect electricity consumption per (gross) tonne-kilometer, i.e. the train length, the gross weight of the train, number of stops, speed, the driving style, topography etc. The ELVIS project initiated a follow-up project that aims to compile and analyze the Transport Administration’s various databases in this area. The project will provide answers to questions such as what data the various databases contain, how data is collected and stored, for what purpose the data is collected and used, the extent to which data is quality assured and how data from different databases can be linked together. In the context of three case studies, Gävle-Malmö, Holmsund–Skövde och Mora-Gävle, several experiments with different explanatory variables were conducted. With regard to the different conditions and priorities in the case studies and experiments, it is difficult to make direct comparisons. Some general conclusions with respect to the use of electricity can be drawn, for example: • The trains’ weight (in tonnes) and length (number of wagons) affect the electricity consumption per tonne-kilometer in the trials where this is tested. • In some trials there is evidence that there are economies of scale, i.e. that the electricity consumption per tonne-kilometer decreases with increased train weight. • The train driver's driving style (feed back of electricity etc.) affects the energy consumption. This can be seen clearly in the trial Mora–Gävle.

  • 207.
    Viman, Leif
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Gustafsson, Mats
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Slaggasfalt, delrapport C: slitage och bildning av inandningsbara partiklar (PM10)2015Report (Other academic)
    Abstract [en]

    The purpose of the project was to investigate whether the use of slag asphalt in urban and high traffic areas can reduce dust problems during the winter. Wear measurements in PVM presents an unclear picture. Test of particle formation and wear characteristics have been performed in the Road Simulator at VTI on a SMA8 pavement with slag from Ovako Bar. Although an earlier test in the road simulator (PVM) on an SMA11 pavement with the same slag materials are included in this report. Wear measurements in PVM presents an unclear picture probably because of the slag used contained more steel residues than normal slag, resulting in a very uneven surface with protruding sharp steel pieces after some wear of the surface, which in turn led to increased stud protrusion during measurement and the increased wear of the pavement surface. In tests with conventional asphalt stud protrusion is reduced under wear test. It is therefore very difficult to compare the wear measurement on this slag asphalt with results from previous runs on other types of asphalt wearing courses. Because of the unclear development of wear the overriding aim of the investigations could not really be achieved. Wear properties of the SMA8 with slag tested according to the ‘Prall’-method (EN 12697-16) show very high/good abrasion resistance. The tests in the road simulator has also shown that particle formation from SMA8 slag asphalt, measured as PM10, is at the same level as previously tested SMA11 with slag and at similar level than most asphalt wearing courses made from natural aggregates. The particle mass is dominated by particles at two modes, 3 and 6 µm, while the number concentration is dominated by ultrafines at about 20 nm. SMA8 with slag give rise to a much lower number concentration of ultrafines at about 20 nm than the previously tested asphalt pavements and previously tested SMA11 with slag. Element analysis of PM10 shows a distribution very similar to that of the previously tested slag pavement in 2013. Ca, Fe and Si are principal elements in the size fraction 1–10 µm, followed by Al, Mn, Cr and K. Scanning electron microscopy reveals that PM10 particles have angular, grainy and flaky shapes as well as some needle shaped and exhibit typical features of mineral and metallic fragments. Particles down to a couple of 100 nm were observed in the SEM pictures.

  • 208.
    Blomqvist, Göran (Editor)
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Transportforum 2013: granskade artiklar2013Report (Refereed)
    Abstract [en]

    At Transportforum 2013 the participants had the opportunity to send in a manuscript for peer review. The papers have been reviewed by the members of the subject committees. Out of 40 notifications of interest, nine papers were published. Three of the papers are written in English: - Torbjörn Stenbeck, Riksrevisionen: Comparing productivity means to measure design-build pay-off. - Björn Hasselgren, KTH: Pricing principles, efficiency concepts and incetive models in Swedish transport infrastructure policy. - Maria Öberg, LTU: How to create a transport corridor management – a literature review.

2345 201 - 208 of 208
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf