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| 2. |
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| 3. |
- Almemark, Mats, et al.
(författare)
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Aktiva badhus
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet syftar till att ta fram ett underlag som kan ligga till grund för de val man gör som anläggningsägare då en simhall med all kringutrustning skall utformas och byggas, i syfte att såväl byggnation som drift av badhusen ska genomföras på ett så miljö- och hälsomässigt samt ekonomiskt hållbart sätt som möjligt. De aspekter som behandlas är energianvändning, vattenrening, ventilation och innemiljö, driftsoptimering genom simulering av driften med en simuleringsmodell som har tagits fram inom ramen för projektet samt städmetoder. Den övervägande delen av befintliga badhus är utrustade med reningsanläggningar bestående av sandfilter med flockningssteg. I stort sett alla badhus använder klor för att desinficera badvattnet. I och med att problemen med bildning av desinfektionsbiprodukter uppmärksammats i en allt större utsträckning på senare tid så har kompletterande reningssteg tillförts. Membranfiltrering för rening av badvatten har länge varit en allt för energikrävande teknik och därför inte setts som ett gångbart alternativ till sandfilter. Det finns dock en potential för att använda membranteknik i större utsträckning framöver då tekniken utvecklats och idag inte är lika energikrävande som förr. Rent teoretiskt så är energibehovet för membranfiltrering i samma storleksordning som för sandfilter. De badhus som studerats i detta projekt har använt klor för att desinficera bassängvattnet. Inom ramen för projektet har energianvändningen i tre badhus kartlagts, och förslag till energieffektiviseringsåtgärder har tagits fram. Resultatet visar att det är möjligt effektivisera energianvändningen i badhus med i storleksordningen 70 procent jämfört med dagens nivåer, vilket avsevärt förbättrar såväl miljöprestanda som den ekonomiska bärkraften för anläggningarna.
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| 4. |
- Andaloussi, Mounir, et al.
(författare)
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Design, Synthesis, and X-ray Crystallographic Studies of alpha-Aryl Substituted Fosmidomycin Analogues as Inhibitors of Mycobacterium tuberculosis 1-Deoxy-D-xylulose 5-Phosphate Reductoisomerase
- 2011
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 54:14, s. 4964-4976
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Tidskriftsartikel (refereegranskat)abstract
- The natural antibiotic fosmidomycin acts via inhibition of 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), an essential enzyme in the non-mevalonate pathway of isoprenoid biosynthesis. Fosmidomycin is active on Mycobacterium tuberculosis DXR (MtDXR), but it lacks antibacterial activity probably because of poor uptake. alpha-Aryl substituted fosmidomycin analogues have more favorable physicochemical properties and are also more active in inhibiting malaria parasite growth. We have solved crystal structures of MtDXR in complex with 3,4-dichlorophenyl substituted fosmidomycin analogues; these show important differences compared to our previously described forsmidomycin-DXR complex. Our best inhibitor has an IC(50) = 0.15 mu M on MtDXR but still lacked activity in a mycobacterial growth assay (MIC > 32 mu g/mL). The combined results, however, provide insights into how DXR accommodates the new inhibitors and serve as an excellent starting point for the design of other novel and more potent inhibitors, particularly against pathogens where uptake is less of a problem, such as the malaria parasite.
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| 5. |
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| 6. |
- Andersson, Cecilia, et al.
(författare)
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In situ rolling circle amplification detection of Crimean Congo hemorrhagic fever virus (CCHFV) complementary and viral RNA
- 2012
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Ingår i: Virology. - : Elsevier. - 0042-6822 .- 1096-0341. ; 426:2, s. 87-92
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Tidskriftsartikel (refereegranskat)abstract
- Crimean Congo hemorrhagic fever virus (CCHFV) is a human pathogen that causes a severe disease with high fatality rate for which there is currently no specific treatment. Knowledge regarding its replication cycle is also highly limited. In this study we developed an in situ technique for studying the different stages during the replication of CCHFV. By integrating reverse transcription, padlock probes, and rolling circle amplification, we were able to detect and differentiate between viral RNA (vRNA) and complementary RNA (cRNA) molecules, and to detect viral protein within the same cell. These data demonstrate that CCHFV nucleocapsid protein (NP) is detectable already at 6 hours post infection in vRNA- and cRNA-positive cells. Confocal microscopy showed that cRNA is enriched and co-localized to a large extent with NP in the perinuclear area, while vRNA has a more random distribution in the cytoplasm with only some co-localize with NP. However, vRNA and cRNA did not appear to co-localize directly.
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| 7. |
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| 8. |
- Angele, Kristian, et al.
(författare)
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Flow Mixing Inside a Control-Rod Guide Tube : Part 2—Experimental Tests and CFD-Simulations
- 2010
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Ingår i: 18th International Conference on Nuclear Engineering. - 9780791849323 ; , s. 655-663
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Konferensbidrag (refereegranskat)abstract
- Alarge number of control rod cracks were detected during therefuelling outage of the twin reactors Oskarshamn 3 and Forsmark3 in the fall of 2008. The extensive damage investigationfinally lead to the restart of both reactors at theend of 2008 under the condition that further studies wouldbe conducted in order to clarify all remaining matters. Also,all control rods were inserted 14% in order to locatethe welding region of the control rod stem away fromthe thermal mixing region of the flow. Unfortunately, this measureled to new cracks a few months later due toa combination of surface finish of the new stems andthe changed flow conditions after the partial insertion of thecontrol rods. The experimental evidence reported here shows an increasein the extension of the mixing region and in theintensity of the thermal fluctuations. As a part of thecomplementary work associated with the restart of the reactors, andto verify the CFD simulations, experimental work of the flowin the annular region formed by the guide tube andcontrol rod stem was carried out. Two full-scale setups weredeveloped, one in a Plexiglass model at atmospheric conditions (inorder to be able to visualize the mixing process) andone in a steel model to allow for a highertemperature difference and heating of the control rod guide tube.The experimental results corroborate the general information obtained through CFDsimulations, namely that the mixing region between the cold crud-removalflow and warm by-pass flow is perturbed by flow structurescoming from above. The process is characterized by low frequent,high amplitude temperature fluctuations. The process is basically hydrodynamic, causedby the downward transport of flow structures originated at theupper bypass inlets. The damping thermal effects through buoyancy isof secondary importance, as also the scaling analysis shows, howevera slight damping of the temperature fluctuations can be seendue to natural convection due to a pre-heating of thecold crud-removal flow. The comparison between numerical and experimental resultsshows a rather good agreement, indicating that experiments with plantconditions are not necessary since, through the existing scaling lawsand CFD-calculations, the obtained results may be extrapolated to plantconditions. The problem of conjugate heat transfer has not yetbeen addressed experimentally since complex and difficult measurements of theheat transfer have to be carried out. This type ofmeasurements constitutes one of the main challenges to be dealtwith in the future work.
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| 9. |
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| 10. |
- 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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| 11. |
- Antonsson, Stefan, et al.
(författare)
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Low Mw-lignin fractions together with vegetable oils as available oligomers for novel paper-coating applications as hydrophobic barrier
- 2008
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 27:1, s. 98-103
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Tidskriftsartikel (refereegranskat)abstract
- Lignin residues are available in large amounts as kraft lignin from chemical pulping processes. This lignin is mainly incinerated in recovery boilers. The recovery boilers are often the bottle-necks in the overall pulping process when pulp production increases are desired. Through cross-flow nano-filtration of the black liquor from kraft pulping, a low-molecular weight lignin fraction can be removed thus decreasing the organic load on the recovery boilers. The low-molecular weight lignin fraction furthermore exhibit different characteristics compared to other commercial kraft lignins and represents a new raw material source in novel applications. The low-molecular weight lignin was used together with a vegetable oil to produce a new hydrophobic lignin derivative similar to suberin. The lignin and the lignin derivative was analysed with FT-IR, UV-vis and SEC. The ability of the product to make paper surfaces hydrophobic was also evaluated. The results demonstrate the possibility to make a suberin-like lignin derivative that is potentially of interest in paper-coating applications due to its capability to interact well with wood fibres and make paper hydrophobic.
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| 12. |
- Antonsson, Stefan, 1979-
(författare)
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Strategies for improving kraftliner pulp properties
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A large part of the world paper manufacturing consists of production of corrugated board components, kraftliner and fluting, that are used in many different types of corrugated boxes. Because these boxes are stored and transported, they are often subjected to changes in relative humidity. These changes together with mechanical loads will increase the deformation of the boxes compared to the case where the same loads are applied in a static environment. This enlarged creep due to the changes in relative humidity is called mechano-sorptive or accelerated creep. Mechano-sorptive creep forces producers to use high safety factors when designing boxes, and therefore, this is one of the key properties of kraftliner boards. Different strategies to decrease mechano-sorptive creep, and to simultaneously gain more knowledge about the causes for this phenomenon in paper, are the aim of this work. Derivatised and underivatised black liquor lignins, a by-product produced in pulp mills in large quantities, have been used together with biomimetic methods, to modify the properties of kraftliner pulp. Furthermore, the properties of kraftliner pulp have been compared to other pulps in order to evaluate the influence of fibre morphological factors, such as fibre width and shape factor, on the mechano-sorptive creep. In addition the influence of the chemical composition of the kraftliner pulp has been evaluated both by means of treating a kraftliner pulp with chlorite and xylanase and by producing pulps with different chemical composition. By using lignin and biomimetic methods, to create radical coupling reactions, it has been shown that it is possible to increase the wet strength of kraftliner pulp sheets. This method of treating the pulp showed, however, no significant effects on the mechano-sorptive creep. The addition of an apolar suberin-like lignin derivative, which has been shown to be possible to produce from natural resources, did show a positive effect on mechano-sorptive creep properties, but at the expense of stiffness properties in constant climate. Different pulps were compared with a kraftliner pulp and it was observed that the ratio between tensile stiffness and hygroexpansion can be used to estimate the mechano-sorptive creep properties. The hardwood kraft pulps investigated had lower hygroexpansion, probably due to more slender and straighter fibres, and higher tensile stiffness, probably due to lower lignin content. As the lignin content was varied by different methods in kraft pulps, it was observed that increased lignin content gives an increased hygroexpansion and decreased tensile stiffness as well as an increased mechano-sorptive creep. There were also indications of increased mechano-sorptive creep due to higher xylan content.
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| 13. |
- Antonsson, Stefan, 1979-
(författare)
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The Use of Lignin Derivatives to Improve Selected Paper Properties
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ved består huvudsakligen av tre typer av polymerer, cellulosa, hemicellulosa och lignin. Lignin bildas i naturen genom enzymatiskt initierad oxidativ koppling av tre olika typer av fenylpropan-enheter. Dessa bygger genom olika kol-kol- och kol-syre-bindningar upp en amorf tredimensionell polymer. När kemisk massa tillverkas bryts lignin ner och löses ut i kokluten. Luten innehåller de förbrukade kokkemikalierna och bränns generellt i en sodapanna för att regenerera kemikalierna och producera ånga. Sodapannan är emellertid dyr. Därför har den blivit produktionsbegränsande på många massabruk. Att avlägsna en del av ligninet från avluten vore därför önskvärt och att finna ekonomiskt intressanta produkter baserade på lignin från svartlut är därför ett viktigt forskningsområde . Ett lämpligt område för ligninprodukter vore som tillsatts i oblekt massa. Oblekt massa används till stor del för tillverkning av kraftliner, topp- och bottenskikten på wellpapp. När lådor av wellpapp lagras i containrar som färdas över haven, förändras den relativa luftfuktigheten. Detta gör att lådorna kollapsar lättare än om de skulle ha lagrats vid konstant luftfuktighet, även en hög sådan. Detta är på grund av det så kallade mekanosorptiva- eller accelererade krypfenomenet. Genom tillsatts av våtstyrkemedel till kraftliner eller behandla den med hydrofoba ämnen, finns indikatoner på att mekanosorptiva effekten skulle kunna minska. För att försöka minska den effekten har ett lågmolekylärt kraftlignin, som utvunnits med hjälp av tvärsflödesfiltrering av svartlut och svavelsyrafällning, använts. Genom derivatisering av detta lignin med linolja erhölls ett hydrofobt ligninderivat som uppvisar strukturella likheter med biopolymeren suberin. När detta suberinlika ligninderivat tillsätts till massa verkar det mekanosorptiva krypet minska. När lågmolekylärt lignin används tillsammans med ligninradikalinitiatorerna lackas eller mangan(III) i kraftlinermassa erhålls dessutom en våtstyrka på ca 5% av torrstyrkan. Efter aminering av detta lignin gav en tillsatts till kraftlinermassan en våtstyrka på upp till 10% av torrstyrkan. Det finns indikationer på att det mekanosorptiva krypet samtidigt minskar när dessa behandlingar görs som ger upphov till ökad våtstyrka.
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| 17. |
- Bergseth, Ellen, 1979-, et al.
(författare)
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Effects of thrust washer bearing surface characteristics on planetary gear train wear
- 2019
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Ingår i: Wear. - : Elsevier. - 0043-1648 .- 1873-2577. ; 432-433
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Tidskriftsartikel (refereegranskat)abstract
- Thrust washers in spur planetary gears are placed between the planet wheel and planet carrier and act as spacers and wear pads. Metal to metal sliding contact between the planet wheel – washer – carrier causes frictional power losses that, combined with starved lubrication, may cause high contact temperatures and thermo-mechanical effects that potentially trigger thermo-elastic instabilities and excessive local wear. The planetary gear system would benefit from a low-friction interface between the washer and the planet wheel. Five washers with different surface treatments were tested in a full-scale gear rig. These tests were also replicated as closely as possible in a pin-on-disc tribometer. The following types of finishing material treatments were studied: a chemical nickel coating plus polymer on a nitro-carburised surface, a combination of nitro-carburization and solid lubricant layers, electroless deposited chemical nickel coating plus polymer, nitro-carburizing, and manganese phosphating. The frictional results indicate that tribometer tests can be used to compare and classify new washer materials. Lab scale tests show that a new experimental self-lubricating tribomaterial that was applied with laser cladding has a promising potential to increase planetary gear train robustness and service life, especially if the surface is fine grinded.
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| 18. |
- Bolognesi, Margherita, et al.
(författare)
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2D π-conjugated benzo[1,2-b:4,5-b']dithiophene- and quinoxaline-based copolymers for photovoltaic applications
- 2013
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Ingår i: RSC Advances. - 2046-2069. ; 3:46, s. 24543-24552
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Tidskriftsartikel (refereegranskat)abstract
- Two medium gap semiconducting polymers, P(1)-Q-BDT-4TR and P(2)-FQ-BDT-4TR, based on alternate units of alkyl-dithiophene substituted benzodithiophene (BDT) and quinoxaline units (without or with fluorine substitution), are synthesized and fully characterized. The polymers exhibit optical and electrical properties favorable for being employed as donors in BHJ OPV devices, such as: absorption spectra extending up to around 720 nm for a high solar spectrum coverage, deep lying HOMO energy levels for a high device open circuit voltage and LUMO energy levels higher than those of PC61BM and PC71BM for an efficient exciton dissociation. In particular, the presence of alkyl-dithiophene side chains allows us to obtain a high 2D π-conjugation which promotes red shifted absorption profiles, low HOMO energy levels (
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| 19. |
- Brechensbauer Brandin, Madeleine, et al.
(författare)
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Centralen : Studier i området kring Stockholms Centralstation
- 1989
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Rapport (populärvet., debatt m.m.)abstract
- Denna skrift handlar om Centralen i Stockholm och dess närmaste omgivningar, Centralplan, T-centralen, Vasagatan och Klarabergsgatan. Den är resultatet av Arkitekturskolans arbete läsåret 1983- 84 och innehåller förutom en rad projekt också historiska utblickar och samtidskritiska resonemang. En stor del av innehållet redovisades redan våren 1984 - det skedde genom en utställning på Arkitekturmuseet och en preliminär publikation. Materialet har sedan svällt ut med innehållsrika uppsatser om Centralen, om äldre och nyare insatser för att förena konst och arkitektur och om den föga kända, ännu obebyggda Blekholmen.
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| 21. |
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| 22. |
- Eriksson, Jenny, 1975-, et al.
(författare)
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New ways of collecting individual travel information : Evaluation of data collection and recruitment methods
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The overall purpose of the project is to conduct a demonstration study that shows how two data collection methods that have been developed to collect travel survey data perform in the field, and how they perform compared with traditional TS (i.e., postal questionnaires and/or telephone interviews). The project is also intended to provide a better understanding of the ways in which different recruitment methods of respondents can be used so that future TS can be more cost effective.The two collection methods tested consist of a mobile app and an online questionnaire with a map to assist the respondents to identify travel destinations. Three recruitment methods were used, i.e., recruitment via random sampling, a web panel, and crowdsourcing. The portion of the random sample that received an online questionnaire was divided into two groups. Half the group was given no incentive, while the other half received a gift card worth SEK 100 after answering the questioner. Those who were recruited via a web panel and were to use the mobile app were rewarded in the form of a gift card worth SEK 100 if, at minimum, they made corrections to trips made on one day registered in the mobile app. A nonresponse analysis was performed of the random sample for both the online questionnaire and the mobile app. Cost estimates for each collection method and recruitment method were also performed, as were uncertainty estimates.Overall, the study shows that the mobile app registered significantly more trips per respondent than did the online questionnaire, while the distances travelled were comparable. There are several possible interpretations of this. One is that people who responded to the online questionnaire either forget about and/or combined short trips (particularly trips made for the purposes of leisure or shopping, and using the travel modes walking and car). One presumable explanation for this is that it is easier to confirm/correct the trips that the mobile app suggests than it is to recall and enter all trips in an online questionnaire. Another possible interpretation is that people responding to different data collection methods have different travel patterns. Yet another explanation is connected to technique issues regarding the different data collection methods.
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| 23. |
- Eriksson, Jenny, 1975-, et al.
(författare)
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Nya sätt att samla in individuell resvaneinformation : Utvärdering av insamlings- och rekryteringsmetoder
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Inom samverkansprogrammet Nästa generations resor och transporter, som Trafikanalys är huvudansvarig för, har man identifierat ett behov av att finna och utveckla nya lösningar för resvaneundersökningar (RVU:er). Bakgrunden till detta är bland annat sjunkande svarsfrekvenser med dagens metoder, vilket skulle kunna ge problem med representativiteten. Det anses som mycket angeläget att utveckla nya metoder för datainsamling för framtidens RVU:er, både på kort och lång sikt.Det övergripande syftet med projektet är att göra en demonstrationsstudie som visar hur två datainsamlingsmetoder som har utvecklats för att samla in resevaneundersökningsdata presterar i fält, samt hur de presterar jämfört med ”traditionell” RVU (postal enkät och/eller telefonintervjuer). Projektet syftar också till att få bättre förståelse för hur olika rekryteringsmetoder kan användas för att framtida RVU:er ska kunna bli mer kostnadseffektiva. De två insamlingsmetoder som testats är webbenkät med karta och mobilapp. Tre rekryteringsmetoder har använts och dessa är rekrytering via slumpmässigt urval, webbpanel och crowdsourcing.
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