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  • 101.
    Adolfsson, Kristoffer
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Gustavsson Al-Mauly, Mayya
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Samverkan arkitektur och installationer: Osynligt ventilationssystem i utställningssal på Plan 4, Nationalmuseum2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project has been carried out in collaboration with the National Property Board of Sweden. The National Museum is currently undergoing renovation where the goal is to restore the building to its original glory. A new ventilation system is to be installed to facilitate a stable indoor climate for the conservation of museum artifacts. The building has been declared a historical monument which imposes limitations on permissible alterations to its architecture and construction. The degree project examines how to combine these limitations with the demands made on the ventilation system by answering the following question, "How can modern installations be integrated within a historical monument, without affecting the historical value?" To exemplify the complexity of this problem, a section of the building has been chosen and studied in more detail. A principle solution is then presented where the installations are integrated with the surrounding structures.

    The air supply to the exhibition halls on the fourth floor constitutes one of the more complex problems in the building. The installations that service these halls are to be contained within the floor structure above. It is this floor structure that has been studied in more detail. The museum climate and its effects on the artifacts, building construction and installations are studied in depth. Currently the museum environment is a heated topic of discussion where prescribed guidelines are challenged and an international standard is sought. The desired indoor climate determines the scope of the ventilation system. Therefore this report concludes a discussion on the climate requirements presented by the National Museum and how these can be accommodated.

    Our conclusion is that a sustainable integration of architecture and installations can be achieved when the solution is based on the limitations of the building as opposed to the demands of the occupants.

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  • 102.
    Adolphson, Marcus
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Estimating a Polycentric Urban Structure. Case Study: Urban Changes in the Stockholm Region 1991-2004 (vol 135, pg 19, 2009)2010In: Journal of urban planning and development, ISSN 0733-9488, E-ISSN 1943-5444, Vol. 136, no 4, p. 381-381Article in journal (Refereed)
  • 103.
    Adolphson, Marcus
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Tellus Towers, en meningsfull byggnad i den hållbara staden?2018In: Hus mot himlen: Hållbar hybris? / [ed] Olsson K., Olshammar G. och Siesjö B., Malmö: Bokförlaget Arena , 2018, p. 92-117Chapter in book (Other academic)
  • 104.
    Adolphson, Marcus
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Urbanmorfologi, livsstilar och resebeteende2021Report (Other academic)
    Abstract [sv]

    I syfte att minska utsläpp av växthusgaser och motverka klimatförändring har riksdagen antagit ett miljömål om att i transportarbetet öka andelen gång, cykel och kollektivtrafik, och minska andelen bilanvändande. Vilka faktorer som påverkar resebeteenden har dock delvis varit okända. I forskningsprojektet 'Urbanmorfologi, livsstilar och resebeteende' har individers resebeteende relaterats till urbanmorfologi, livsstilar, attityder och demografi. Resebeteende (längd, frekvens och färdmedel) avser resor till arbete, service och fritidsaktivitet. I studien ha en social-psykologisk modell används för att utveckla variabler beskrivande miljömässiga så som individuella aspekter. Studien baseras på en enkätundersökning och precisa rumsliga beskrivningar. Studieområdet är Stockholms län. Enkäten genomfördes våren 2019. Studien visar på att både urbanmorfologi och demografi, liksom livsstilar och attityder påverkar resebeteenden. Det är därför av avgörande betydelse att stads- och regionplaneringen har kunskap om dessa relationer för att kunna bidra till utvecklingen av ett hållbart samhälle

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  • 105.
    Adolphson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning.
    Impact on urban form by the localization of railway stations: Evidence from Sweden2019In: Cities, ISSN 0264-2751, E-ISSN 1873-6084, Vol. 95, article id 102362Article in journal (Refereed)
    Abstract [en]

    Since the 1990s a number of new railway stations have been established in Sweden on new or rerouted lines, while other stations have been reconstructed at their original locations. Some stations were located in urban surroundings, others in semi-urban or peripheral locations depending on the trade of between regional speed, and local urban circumstances. The urban form consequences depending on station localisation of these transport infrastructure investments are nonetheless unknown. In order to provide a basis for future planning, this research aims to provide knowledge on urban form consequences of relocating railway stations. 13 stations were selected in a case study. Changes in urban densities from 1993 to 2013 were analysed by a combination of kernel techniques and estimation of monocentric density models. Stations within an urban and semi-urban environments show strong agglomeration tendencies. Within peripheral environments, the urban development was unclear or even negative. In an urban environment, the location of the station still attracted more urban resources compared to the location of the urban density centre. These findings should be understood in the light of a market-oriented socio-economic context since 1990th influencing the planning system and the development of urban form.

  • 106.
    Adolphson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Jonsson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, System Analysis and Economics.
    Uncover the theory practice gap in Swedish transport planning: an interdisciplinary approach2020In: European Planning Studies, ISSN 0965-4313, E-ISSN 1469-5944, Vol. 28, no 11, p. 2237-2260Article in journal (Refereed)
    Abstract [en]

    This paper analyses the gap between planning theory and planning practice in Swedish infrastructure planning. Planning theory was of limited relevance in order to understand the planning processes and the documents. Instead sociology, political theory and philosophy appeared as useful theoretical resources. Bourdieu’s theories on social and cultural capital, and ‘the feel for the game’ were useful in understanding planning practice. In order to develop communicative planning theory into a useful asset for planning practice the system perspective and the emphasis on public spheres from Habermas communicative action theory, critical realism and political pluralism might well serve as theoretical point of departures.

  • 107.
    Adolphson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Olsson, Krister
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Urban structure and social life: the planning for relocation of Kiruna townArticle in journal (Other academic)
  • 108.
    Aejmelaeus-Lindström, Petrus
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Opera i Stockholm, Stadsgårdskajen2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 109.
    Af Klintberg, Albin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Åkehag, Jonny
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Träbjälklag med tung fyllning: Bjälklag framtaget med inspiration av byggteknik från sekelskiftet 1800–19002017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report investigates the possibilities of using residual products as sound insulation in apartment

    separating timber floors with a span of 6 m. One step towards meeting the Swedish construction

    industry's zero vision for carbon dioxide emissions is to build more using timber and to reuse/recycle

    residual products. The Swedish building contractor Skanska has at its quarries a surplus of material in

    the form of crushed rock of the 0 - 0.2 mm fraction and crushed residual concrete. In this report, a

    prototype of a timber floor has been produced with influences of construction technology from the

    turn of the 19

    th century regarding the use of heavy filling as sound insulation in timber floors.

    The developed floor prototype complies with the requirements set in BBR after dimensioning

    according the Eurocodes regarding fire safety, strength, sagging and deflection. According to a

    simulation in SEAWood, a tool for acoustic simulation which is under development at RISE Research

    Institutes of Sweden the requirements for sound insulation are also met, which is supported by

    analyzes made by comparing with data on similar timber floors. The high mass of the filling material

    implies that the prototype is a low frequency floor, this in conjunction with the simulation only being

    an indication of sound insulation properties, it will require practical tests to determine the prototypes

    sound insulating and dynamic properties.

    The developed floor prototype is suitable for prefabrication thanks to a design with few components.

    Prefabrication of the floor has in addition to the economic benefits it brings great benefits from a

    working environment perspective and is also beneficial from a moisture point of view.

    To estimate the environmental impact of the timber flooring, a simple comparison was made with a

    prefabricated concrete floor which showed that carbon dioxide emissions up to the using phase were

    more than twice that of the concrete floor than for the prototype floor.

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  • 110.
    af Klintberg, Tord
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Heated air gaps: a possibility to dry out dampness from building constructions2008Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The air gap method is a modification of the common way of building indoor walls and floors. The aim of the method is to make a construction, less fragile to water damage, with air gaps where moisture can be removed with a thermally driven air flow, caused by a heating cable. The thesis includes a number of experimental studies of this method.

    Temperature and convective air flow in a vertical air gap was studied and it was noted how air flow increased with raised power of the heating cable. The air flow for one meter of wall varied between 50 m3/day (13 air changes per hour) and 140 m3/day (36 air changes per hour). The lower value was caused by a temperature difference in the range 0.2-0.3 oC. Without heating no air flow was found.

    In studies of moisture and RH in wet “slab on ground” constructions, it was noted how the slab in the room with the air gap method dried to a much higher extent than the slab in the room built in an ordinary way. It was also noted that moisture was transported from the air gap in the floor and up through the air gap in the wall. In the room with the air gap construction, the RH values beneath the floor was at a lower level (and below 75 % RH) than the RH values beneath the floor of conventional construction. Mould does not grow below 75 % RH.

    In the study of a flooded intermediate floor it was noted how the thermally driven convective air flow evidently speeded up drying of the construction. Mould growth was only noted in the case where the heating cables were turned off.

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    FULLTEXT01
  • 111.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Air gap method: measurements of airflow inside air gaps of walls2008In: Structural Survey, ISSN 0263-080X, E-ISSN 1758-6844, Vol. 26, no 4, p. 343-363Article in journal (Refereed)
    Abstract [en]

    Purpose - Water damage is a severe problem in modern construction, causing economic loss and health implications. By using the patented Air Gap Method inside building constructions, harmful water in the construction can be dried out. The method drains and ventilates air gaps inside walls and floors with an airflow driven by thermal buoyancy caused by a heating cable in vertical air gaps. This paper aims to investigate this method and measurements of airflow inside air gaps of walls. Design/methodology/approach - This study investigates the measured correlation between the power of the heating cable, the difference of temperature inside and outside the air gap, and the airflow. Data are collected by experimentation with a full-scale constructed wall. Findings - The study finds that airflow increases with raised temperature difference between the air gap and room and with raised power of the heating cable. The measured airflow reaches values up to 140 m3/metre wall and day for one cable. A small increase in temperature, between 0.2 and 0.3 oC inside the vertical air gap results in an air flow of approximately 60 m3/metre wall and day. The air change rate per hour for the air inside the wall construction varies between 15 times for a 6 W/m cable and 37 times for a 16 W/m cable. Practical implications - The method provides the means to build houses in a more robust way, minimising the negative effects of water damage. This investigation provides an understanding of how temperature and ventilation are related in this method of construction. Originality/value - The issue of ventilated construction is rarely investigated in scientific research.

  • 112.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Finlands åtgärder mot arbetslivskriminalitet, människohandel och grå ekonomi2024Report (Other (popular science, discussion, etc.))
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  • 113.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Sustainable Buildings.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Sustainable Buildings.
    Rättvist Byggande byggkriminalitet och Sveriges sekretesslagstiftning2021Report (Other academic)
    Abstract [sv]

    Studien bygger på intervjuer och samtal med 64 personer hos bl. a. myndigheter & fastighetsbolag.

    Byggkriminaliteten belastar samhället på flera olika sätt. Personer i utsatta lägen, exempelvis pappers-lösa, blir utnyttjade genom att få arbeta långa dagar med låg lön, ofta under ofta farliga förhållanden. Dessutom blir hederliga byggbolag utkonkurrerade då kriminella bolag kan vinna upphandlingar, genom låga anbud. Kriminella bolag försöker sedan få till ytterligare intäkter, exempelvis genom att ge dåliga leveranser, som i sin tur genererar dem intäkter i form av ändrings- och tilläggsarbeten. Detta visar i sin tur att byggnadskvaliteten blir försämrad av de kriminella bolagens aktivitet. Vidare går svenska staten miste om betydande skatteintäkter. Kriminella bolag gör å sin sida stora vinster och dessa vinster kan sedan användas till annan aktivitet, exempelvis att köpa upp hederliga bolag. Vår analys är att ekonomisk vinning är ytterst centralt för kriminella bolag, samtidigt som de gärna vill framställa sig som ytterst hederliga. Därför är det möjligt att bekämpa dem ur ett ekonomiskt pers-pektiv, Här har det dock visat sig att Sveriges befintliga sekretesslagstiftning utgör ett operativt hinder.

    Dagens svenska sekretesslagstiftning grundar sig på farhågor som fanns på 1970-talet, att Sverige skulle förvandlas till Oceanien i Orwells 1984 genom att myndigheterna samkörde sina register. Sekretesslagstiftningen skapades 1979/80, i syfte att försvara den personliga integriteten, men lagen förhindrar nu att myndigheter på en löpande basis samarbetar mot kriminella bolag. Detta gäller även Skatteverkets olika enheter där Skattebrotts- och Beskattningsenheterna inte löpande får samarbeta mot kriminalitet. Föreslag har lagts fram att lagen ska ändras, så att myndigheter får samarbeta, men frågan har till slut behandlats som en mer avgränsad integritetsfråga ur en strikt juridisk synvinkel.

     Vi frågar oss om Regeringar och Justitiedepartement har ägt tillräcklig insikt eller kraft för att förbereda förslag, vilka kan ligga till grund för lagstiftning, som är operativ mot byggkriminalitet, men även tar hänsyn till integritet. Att försvara den personliga integriteten är vällovligt, men det är stötande att skärpt lagstiftning mot arbetslivskriminalitet inte utvecklas, därför att ett fåtal remissinstanser vill stoppa sådana lagar med ett snävt integritetsförsvar. Detta får en stor negativ påverkan på Sveriges förmåga att agera mot byggkriminaliteten. 

     

    Till skillnad från Sverige så har Finland en lagstiftning, som tillåter finska myndigheter att operativt agera mot kriminella företag. Den finska Skatteförvaltningen erhåller information om byggarbetares arbetsgivarsamband och arbetstid, om byggentreprenörers fakturering, samt gängse deklarationer. Dessutom kan den finska Skatteförvaltningens olika enheter samarbeta löpande med varandra utan sekretesshinder, vilket det svenska Skatteverket är förhindrat att göra. Man kan fråga sig om Finlands system är farligt för den personliga integriteten för människorna i Finland? 

     I ljuset av Sveriges nuvarande bekymmer avseende arbetslivskriminalitet och arbetskraftsutnyttjande bör en forskargrupp etableras, knuten till Justitiedepartementet, där juridik- och samhällsforskare samarbetar i syfte att lägga fram underlag till en ny sekretesslag. I det sammanhanget vore det intressant att studera forskningsinstitutet HEUNIs verksamhet vid Finlands Justitiedepartement. 

     Intervjupersoner i denna studie anser att Rättvist Byggande är ett bra initiativ av Stockholmshem, som tar ett utökat byggherreansvar. Det är dock huvudentreprenören, som ska ta  ansvar för arbetsplatsen. Andra renodlade byggherrar ansluter sig nu till initiativet vilket är bra. Rättvist Byggande kommer framför allt åt den kriminalitet, som består av att fel personer befinner sig på bygget och Stockholmshem har rätt att utestänga byggbolag som missköter sig från kommande upphandlingar. 

     Sammantaget finns flera organisationer som genomför viktigt arbete med kontroller mot byggkrimina-litet. Kontroll kostar dock pengar att genomföra, vilket exempelvis påverkar ett fastighetsbolags eko-nomi och i slutändan kommer att betalas av de boende. Om Sverige hade Finlands system där Skatte-förvaltningen har tillgång till siffror på antal anställda för varje entreprenör, entreprenörernas faktu-rering och samband mellan arbetsgivare och arbetstagare, så skulle kontrollen bli enklare och ändå tjäna samma syfte. Brottsbekämpningen skulle bli mer kraftfull och ge en större samlad effekt än vad enskilda goda initiativ kan ge. Det skulle dessutom ge färre förluster för statskassan, stödja hederliga byggföretag och på sikt relativt sett förmodligen ge lägre boendekostnader. Vi frågar oss hur mycket Sveriges arbetsgivaravgifter och inkomstskatter skulle öka om det finska systemet skulle införas.

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    Rättvist Byggande
  • 114.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Sustainable Buildings. Civil and Architectural Engineering.
    Västertorps simhall - Klorreduktion med hjälp av blått ljus och fotokatalys2023Report (Other academic)
    Abstract [sv]

    Västertorps simhall, byggd på 1960-talet, har försetts med partikelräkning och fotokatalys i reningsverket samt blått ljus i simhallen till en investeringskostnad på cirka två miljoner kronor. 

     

    ·       Fotokatalysen utförs med AOT-apparaturen, vilken består av en UV-lampa inuti ett rör, som på insidan är täckt med titanoxid. När UV-ljuset träffar titanoxiden splittras vattenmolekyler till väteatomer (H) och väteoxid (OH), där båda är starka radikaler. Dessa vattenradikaler oxiderar organiska ämnen till koldioxid och vatten och dödar mikroorganismer. Ungefär 20 % av det cirkulerande vattnet har gått igenom fotokatalysen.

     

    ·       Det blå ljuset i simhallen aktiverar porfyrinmolekyler inuti bakterier och detta skapar även här vattenradikaler, som dödar bakterien från insidan. Det blå ljuset har varit tänt på nätterna, alltså en tredjedel av dygnets alla timmar.

     

    ·       Partikelräknaren räknar partiklar i bakteriestorlek i denna studie och hypotesen var att det snabbt skulle gå att detektera en ökad bakterieförekomst i badvattnet. Det blev dock bakterietillväxt i slangen som leder till räknaren och slangvattnet kan inte antas vara representativt för bassängvattnet. 

     

    Västertorps simhall har kunnat sänka sin klortillsats till hälften, men ändå haft acceptabla låga bakteriehalter med inverkan av det blå ljuset och fotokatalysen, även om det blev större spridning av bakterienivåerna vid den lägsta klornivån (0,4 mg Cl/liter). Bakterienivåerna har alltså varit låga trots att hydrauliken (vattenflödet från bassäng till reningsverk och vice versa) i simhallen är uttalat dålig. Alla vattenkemiprover i studien visar också på i stort sett oförändrade resultat, jämfört med normal klorering. Dock har kloridhalten sänkts till signifikant lägre nivåer, vilket med hög grad av sannolikhet leder till längre livslängd för anläggningen. Det förefaller också som om luftkvaliteten har förbättrats med lägre klornivåer, mätningar visar på låga nivåer av den ohälsosamma gasen trikloramin. Med denna metod finns en risk att bakterieväxt sker i badets rörsystem och för att förhindra detta bör Västertorps simhall extrakloreras med jämna tidsintervall, med en tidsfrekvens som bör provas ut. 

     

    Blått ljus innebär en risk för ögon, men om det blå ljuset kan vara på alla dygnets timmar och om mer vatten kan gå genom fotokatalys, så skulle förmodligen klortillsatsen kunna sänkas ytterligare. Då skulle simhallen bestå längre tid och halten av ohälsosamma gaser minska ytterligare. Detta kommer dock i konflikt med myndigheters riktlinjer. Arbetsmiljöverket saknar relevanta riktlinjer för blått ljus i simhallar och Folkhälsomyndighetens riktlinjer avseende klorhalter avråder från ytterligare klorsänkningar. Relevant vetenskapligt arbete behövs för att myndigheterna ska kunna ändra sina riktlinjer, enligt frågorna:

    ·       Kan det blå ljuset vara på dygnet runt? Ett vetenskapligt utredande arbete krävs för att komplettera Arbetsmiljöverkets riktlinjer. Detta kan genomföras av forskare vid ST: Eriks Ögonsjukhus i samarbete med optiska forskare vid KTH.

     

    ·       Vilka bakterier växer under blått ljus, dels i badvattnet, dels på gångytor? Detta går att utröna med metodstudier av forskare på Karolinska Sjukhuset, som har metoder att jämföra simhallens bakterier med ett bibliotek med patogena bakterier.

     

    ·       Vad sker i fotokatalysen? En hypotes är att den ohälsosamma gasen trikloramin bildas tillsammans med urinämne, som avges i svett. Fotokatalysen kan eventuellt bryta ner urinämne till koldioxid och ammoniak och på så sätt bryts bildandet av trikloramin. Detta kan studeras med metodförsök på KTH/Kemi, som har tillgång till LC-MS (Liquid chromatography–mass spectrometry) där urinämne kan detekteras.

     

    ·       Vad kan ge ytterligare minskad korrosion? Klorering bildar löst klorgas i badvattnet, som är mycket korrosivt, frånsett korrosion som sker via klorider. Sambandet kan undersökas av Rise/Korrosionsinstitutet vid olika klorid- och pH-nivåer med Institutets flödesmetod.

     

    Vidare visar denna studie att ytterligare försök med blått ljus och fotokatalys kan utföras på andra simhallar inom Stockholms Stad, i ett samarbete mellan Fastighetskontoret, Idrottsförvaltningen och Miljöförvaltningen. Förmodligen är det en fördel om även KTH kan engageras i detta arbete. Olika simhallar kan antas ha särskilda möjligheter och problem och då kan de forskningsperspektiv och kunskaper, som KTH erhållit vara till nytta.

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  • 115.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Högberg, Lovisa
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Stegvis renovering2020Report (Other academic)
    Abstract [sv]

    Den tekniska utvecklingen medför att det finns ett ökande utbud av metoder för att göra renovering stegvis. Det finns också en utveckling mot att renoveringsåtgärder kan göras kortvarigt, så att de boende inte behöver störas så svårt.

     

    Det går att genomföra en stegvis renovering på ett flertal teknikområden, exempelvis av rör, badrum, fönsterbyten. Utvecklingen av relining i olika typer av rör och kanaler har inneburit en stor förändring i och med att åtgärder för renovering kan göras i stort sett utan att riva i stommar och schakt, även i fall då rör och kanaler är ingjutna. Både resultat av experiment i detta projekt och insamlade erfarenheter visar att relining är ett koncept som nu är i stark utveckling och som kommit för att stanna. Användning av relining är även gynnsamt ur ett LCA-perspektiv.

     

    Stegvis renovering ger ofta ett mer ekonomiskt och ett mindre komplext renoveringsförfarande. Bland annat gäller:

    • När systemen renoveras i taget, så optimeras livslängden för dem, vilket är kostnadseffektivt.
    • Det är mer hanterbart att bara renovera ett system i taget och arbetet blir mer effektivt.
    • Stegvis renovering minimerar antalet inblandade yrkesgrupper och minimerar då även missförstånd mellan dessa yrkesgrupper och missförstånd med beställare och boende.
    • Omvärldsfaktorer kan bättre kontrolleras vid stegvis renovering och arbetet blir då mer industriellt och därmed och effektivare.
    • Om byggnadens system renoveras ett i taget som kortvariga kampanjer, så ökar möjligheten för boende att bo kvar under processen, vilket sparar pengar för fastighetsbolaget.
    • Stegvis renovering gör det lättare för byggherren att behålla kontrollen över projektet, bland annat förenklas upphandlingsprocessen.

     

    Nuvarande lagstiftning hindrar en värd att ta betalt för underhåll. Detta är ett arv från den bostadssociala utredningen, som tillsattes 1932. Då var byggnads- och boendesituationen helt annorlunda än nu, exempelvis avseende inomhusmiljö och hygien. Det fanns då många bostäder med usel uppvärmningssituation utan varmvatten och många bostäder med torrdass på gården. Det fanns inte heller någon allmännytta som kunde hålla hyror på en rimlig nivå för ett flertal, istället fanns det somliga hyresvärdar som utnyttjade en bostadsbrist med ohemula hyror. Det var då fullt rimligt att den bostadssociala utredningen kom fram till att en hyresvärd endast skulle kunna höja hyran om det gjordes standardhöjningar. Om bostadssituationen då hade liknat dagens ur ett inomhusmiljö- och hygienperspektiv kan man undra ifall utredningen kommit till samma resultat.

     

    Fortfarande är det så att en hyresvärd bara kan göra hyreshöjningar för underhållsåtgärder om alla hyresgäster går med på det. Om en boende tar frågan till hyresnämnden så kommer värden att fällas och hyreshöjningen accepteras inte. Fastighetsägaren är alltså tvungen att tillgripa standardhöjande åtgärder och dessa kan vara väl så dyra om inte dyrare för de boende än de nödvändiga underhållsåtgärderna. Det finns då en risk att en oseriös fastighetsägare genomför standardhöjande åtgärder och höjer hyran utan att vidta nödvändigt underhåll. En fastighet med höga hyror kan sedan säljas. Till slut blir hyresgästerna drabbade, både av höga hyror och av ett hyreshus, utan fungerande system. Lagen bör ändras, så att om en majoritet av de boende accepterar att betala för underhållsåtgärder så bör detta gälla. Dessutom bör en majoritet av de boende acceptera standardhöjande åtgärder för att dessa ska bli av.

     

    Stegvis renovering har tillämpats fullt ut vid Knivstabostäders renovering, som resulterade i hyreshöjning på 13 %. En förutsättning för detta var dels att fastighetsbolaget var helt transparenta med ekonomin, undvek fördyrande standardhöjande åtgärder och fick ta betalt för sina underhållskostnader.

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    Stegvis renovering
  • 116.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Sustainable Buildings.
    Högberg, Lovisa
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Brick, Karolina
    Riksbyggen.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Kristoffersson, Jan
    Sustainable innovation.
    Riksbyggens renoveringsverkstad 2: Energieffektivisering i samband med renovering hos bostadsrättsföreningar2012Report (Other academic)
    Abstract [en]

    The results of this project show that the main barrier is financial. It is difficult to justify measures such as additional insulation of facades or heat recovery from ventilation air, If you do not count with any real rising in energy prices. The individual cases can of course differ and it is important to examine the profitability of investments in connection with the planning of major maintenance and refurbishment. Ongoing technology development may also contribute to make this kind of measures more interesting in the future. The result from the previous project that optimizing measures (eg adjustment of the heating system) often are very profitable is also confirmed in this project. The economy would naturally be affected by introduction of policy instruments and incentives. However, it is quite doubtful to prioritize instruments for reducing heat used in apartment buildings, since this to a large extent is produced from renewable energy sources (compared to eg traffic).

    The project has also studied how the banking and insurance sectors could contribute to more energy efficiency in housing cooperatives. The conclusion is that these industries have a rather marginal ability to influence. However, there may be a possible "trigger effect” if there are special offers on the market for associations, actively working with their energy efficiency. The work continues to explore different possibilities in that area.

    The project has studied Riksbyggen’s current range of energy related services and has several suggestions for additional services and processes. This applies both to the long-term financial planning, which is an important factor for the cooperatives to be properly prepared for larger investments, and the more short-term / operational planning when the cooperatives are approaching decisions on major maintenance measures. Related to this, various forms of training, especially for the boards of the cooperatives, is of great importance. The project proposes a broad educational effort, based on role-playing. Riksbyggen may also develop the role as a competent discussions partner to the cooperatives and also encourage networking among housing cooperatives for facilitating dissemination of information and perhaps even coordination of efforts.

     

    This project is a direct continuation of the Riksbyggen’s renovation workshop. That project has analysed barriers to more extensive energy saving processes and how these can be bridged, based on housing cooperatives and the environment they are a part of. The project Riksbyggen’s renovation workshop was conducted as a joint project of Riksbyggen, KTH and Sustainable Innovation in 2010-2012 with the aim to highlight good examples of renovation efforts of housing cooperatives ,that can help reduce energy consumption. The project showed that there are good economic potential for energy savings, mainly through operational optimization and other less extensive measures.

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    Riksbyggens renoveringsverkstad 2
  • 117.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Jóhannesson, Gudni
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Air gaps in building construction avoiding dampness and mould2008In: Structural Survey, ISSN 0263-080X, E-ISSN 1758-6844, Vol. 26, no 3, p. 242-255Article in journal (Refereed)
    Abstract [en]

    Purpose - Water damage is a severe problem in modern construction, causing economic loss and health implications. The patented Air Gap Method, which is a slight modification of the common infill wall construction, provides means to build houses in a more robust way, minimizing the negative effects of water damage. This full-scale study of the method aims to show how walls and floors may be built to create ventilation within the construction, with air gaps equipped with heating cables. The general hypothesis is that the patented Air Gap Method drains and evaporates dampness after water damage. The purpose of this study is to show how the method is built and how the method deals with water damage, such as a flooding, and with mould growth. Design/methodology/approach - The Air Gap Method is based on a common timber-framed construction and is completed by the provision of inlets, air gaps, slits, and outlets. The power for the convective airflow is given by an electrical heating cable. The study was carried out as a full-scale experiment using a 24m2 large apartment build by this method. This apartment was flooded with 120 litres of domestic wastewater and the drying period was compared when heating cables were switched on or not. Mould growth was also investigated. Findings - The method dries out a flooded floor in nine days when two heating cables were switched on, in 13 days with one heating cable and 21 days when the heating cables were off. The method prevents all mould growth provided that the indoor RH is lower than 65 per cent. Practical implications - The method provides means to build houses in a more robust way, minimizing the negative effects of water damage. Originality/value - The issue of ventilated construction is rarely investigated in scientific research.

  • 118.
    af Klintberg, Tord
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Krav på tillgänglighetsanpassning vid renovering: Ett diskussionsinlägg2016Report (Other (popular science, discussion, etc.))
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    fulltext
  • 119.
    Afridi, Muhammad Amjad
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Skellefteå Municipality, Strömsörgatan 15, 93134 Skellefteå, Sweden.
    Municipal street pavement maintenance and management practices in Sweden2024Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    A well-functioning street network is pivotal in the socio-economic development of a region. Street networks not only facilitate the movement of people and goods but also allocate space for utility services. Maintaining the street network in good condition and meeting the sustainability targets necessitate implementing optimal street maintenance strategies, leading to an efficient utilization of taxpayers' money. 

    The objectives of this Licentiate thesis are to analyse pavement management practices and challenges faced by Swedish municipalities, specifically focusing on asphalt concrete (AC) pavements within street networks. Additionally, it seeks to integrate a sustainability tool into pavement maintenance to select maintenance measures that contribute to sustainability goals at the municipal street network management level. Furthermore, the study aims to enhance municipal-level pavement maintenance approaches through the implementation of machine learning (ML) models within a pavement management system (PMS). 

    Within this context, three individual studies were conducted—two case studies and a survey involving Swedish municipalities. One case study explores sustainability framework application, whereas the other investigates the utilization of ML models in municipal AC pavement maintenance. The survey investigates the practices and challenges faced by municipal street network administrations in AC pavement maintenance.

    The sustainability framework SUNRA (Sustainability National Road Administrations) was adopted by the Swedish Transport Administration (STA) with a primary emphasis on promoting sustainability in pavement management on state-level roads. In this study, the framework has been tested, applied and further streamlined to be applicable for setting sustainability targets and monitoring sustainability performances at the project level within both the STA and municipal contexts. The aim was to simplify the framework so it is appropriate for investment, re-investments, maintenance and operation projects and also to enhance its applicability for various users. The study additionally explored how the framework could contribute to sustainability, identified the drivers and barriers for its application, and examined its applicability and adaptability to projects of varying complexities. The results indicate that the framework can be readily utilized and adapted for investment, reinvestment, maintenance, and operational pavement projects during the planning stage. Additionally, it is also suitable for small municipal establishments, construction or reconstruction of residential areas, and regular maintenance.

    A web-based questionnaire survey was disseminated to municipalities across the country to gather first-hand insights into the current practices and challenges associated with street maintenance at the municipal level in Sweden. Survey responses were received from 147 of the 290 (51%) municipalities nationwide. The study reveals that predominant pavement distress encompasses potholes, surface unevenness, and alligator cracking, with the most prevalent causes being pavement ageing, heavy traffic, and patches. Likewise, cold climate and population density serve as influential factors contributing to pavement deterioration. The automated survey methods for collecting pavement condition data, such as road surface scanning vehicles and application of commercial PMS, are very limited. On the contrary, the windshield method, a subjective approach for pavement condition assessment, is widely adopted among municipalities utilizing PMS. The allocation of the budget for maintenance, rehabilitation and reconstruction is higher in the northern regions of the country, as well as in densely populated municipalities.

    Manually collected pavement condition data for the years 2014 and 2018 were acquired from Skellefteå municipality to assess the performance of ML models in comparison to the observed pavement condition index (PCI) of the street network. In this context, the supervised ML models Linear Regression (LR), Random Forest (RF), and Neural Network (NN) were employed in conjunction with several variable combinations. The RF model, utilizing paired variables of pavement age (A) and pavement distresses (D) data, consistently demonstrated higher accuracy compared to the other models for residential streets. However, RF models constructed with paired variables of A and traffic (T) consistently outperformed other models in the context of non-residential streets. The significance of input variables fluctuates based on the model's complexity and the pavement performance objective. Nonetheless,  variable A consistently emerges as the predominant factor for predicting PCI in both residential and non-residential street models. 

    Further evaluation of the models and simplification of the SUNRA framework to enhance pavement performance and sustainability are recommended. 

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    Kappan_utan artiklar
  • 120.
    Afridi, Muhammad Amjad
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Skellefteå Municipality, Strömsörgatan 15, 93134 Skellefteå, Sweden.
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Swedish National Road and Transport Research Institute, 58195 Linköping, Sweden.
    Englund, Cristofer ()
    Center for Applied Intelligent Systems Research (CAISR), Halmstad University, 30118 Halmstad, Sweden.
    Predicting pavement condition using an ML approach: A municipal case studyIn: Journal of Transportation Engineering, Part B: Pavements, ISSN 2573-5438Article in journal (Other academic)
  • 121.
    Afridi, Muhammad Amjad
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Skellefteå Municipal, Skellefteå, Sweden..
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Swedish Natl Rd & Transport Res Inst VTI, Linköping, Sweden.;Univ Iceland, Fac Civil & Environm Engn, Reykjavik, Iceland..
    Sjogren, Leif
    Swedish Natl Rd & Transport Res Inst VTI, Linköping, Sweden..
    Municipal street maintenance challenges and management practices in Sweden2023In: Frontiers in Built Environment, E-ISSN 2297-3362, Vol. 9, article id 1205235Article in journal (Refereed)
    Abstract [en]

    The municipal street network acts as a multifunctional asset by providing people, vehicles and public services with a well-functioning infrastructure. To keep it in good condition, optimal maintenance measures are required which would result in an efficient use of taxpayers' money. This paper investigates the street network deterioration processes and the management practices that the municipal administrations have applied in Sweden. The study is based on a survey with Swedish municipalities using questionnaires and complementary interviews. The answers provide insight into a wide range of common pavement distresses and deterioration factors, along with pavement management practices. The study identifies that potholes, surface unevenness and alligator cracking are the most cited challenges, while pavement ageing, heavy traffic and patches are the most noted causes. Similarly, the cold climate and population density are influential factors in pavement deterioration. Allocation of the maintenance and rehabilitation and reconstruction budget is higher in the northern part of the country as well as in densely populated municipalities. Condition data collection and use of commercial Pavement Management Systems (PMS) are limited. Addressing the challenges effectively may be possible through the enhancement of the budget, feasible/clear guidelines from municipal councils/politicians, and reducing the gap between street network administrations and utility service providers.

  • 122.
    Afrin, Shahrina
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Green Skyscraper: Integration of Plants into Skyscrapers2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This research has been emphasized on integration of plants in skyscraper design which play a vital role for the energy conservation by the building as well as improving the living quality into these vertical cities. Throughout the thesis work it has been studied to establish the necessity of planting to incorporate into skyscrapers, for the well being of our economy, society and the environment. The rules and regulations in various countries have been studied. The provisions of integrate plants into skyscraper includes the four possible options like, Green roof, Green wall, Biofilter and Indoor potting plants which can be incorporate into the  esign. Benefits and impacts have been studied in terms of energy savings and  ndoor environmental qualities. For example green roof can reduce 50% of cooling  oad; green wall can reduce 10 degree centigrade indoor temperature, where as biofilter and indoor plants purifies indoor air by 50% to 60%. Available technologies for green installments, like complete, modular and vegetated blanket system for green roof; modular, freestanding and cable-rope system for green wall; active and passive system for biofilter and different types of indoor plants have been addressed here along with their examples and case studies. At the end the  ecommendation shows that integration of plants into skyscrapers can change the micro and macro environment, climate, can restore the ecology and benefited to the economy. Results are the noticeable decrease in urban heat island, rapid reduction of energy consumption and cost, refreshing air for a healthy environment.

    Key words: Green Skyscraper, integration of plants, green roof, green wall, biofilter, ecological impact, climate, energy savings, indoor air quality, aesthetics, design technology.

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    FULLTEXT01
  • 123.
    Afshar, Samim
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Alaoui, Youssef
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Jämförelser mellan massivträ- och betongstommar i flerbostadshus: Bedömning av byggtid, väderkänslighet, arbetsmiljö, bekant byggteknik, installation, projektering, spännvidder, flexibilitet, brandsäkerhet, ljudisolering och fuktsäkerhet.2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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    fulltext
  • 124.
    Agampatian, Razmik
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Geoinformatics.
    Using GIS to measure walkability: A Case study in New York City2014Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    Obesity has become a global epidemic due to changes in society and in behavioral patterns of communities over the last decades. The decline in physical activity is one of the major contributors to the global obesity epidemic. Thus programs, plans and policies that promote walking could be a possible solution against obesity and its comorbidities. That is because walking is the simplest and most common form of physical activity among adults, regardless of age, sex, ethnic group, education or income level.

    The characteristics of the built environment might be significant factors that affect people’s decision to walk. Thus, measurable characteristics can assist in determining the extent to which the built environment affects the people. These characteristics can also provide indirect evidence of the state of population health for the area under study. Towards the analysis and assessment of potential associations between a number of measures of the built environment and walking, Geographic Information Systems have an increasing acceptance. Composite measures, also known as Walkability Indices, are a promising method to measure the degree to which an area provides opportunities to walk to various destinations.

    The main objective of this research is to develop a method to model walkability drawing partially from previously developed Walkability Indices and walkability measures, and suggest eventually an improved Walkability Index composed of 6 parameters. These are: i) Residential Density, ii) Diversity – Entropy Index, iii) Connectivity, iv) Proximity, v) Environmental Friendliness, vi) Commercial Density – FAR. The chosen spatial unit of analysis is the Census Tract level. The method of buffering that defines spatial units around geocoded locations at a given distance is also employed in an attempt to suggest an improvement of previously used methods. The study area is New York City (NYC).

    The results imply that Manhattan is the most walkable Borough, while Staten Island is the least walkable Borough. It is also suggested that NYC has a centripetal structure, meaning that the historical center and the entire island of Manhattan is more developed, and more walkable, followed by the adjacent areas of the neighboring Boroughs of Bronx, Brooklyn and Queens. The farthest areas of NYC’s periphery are consistently found to have the lowest walkability. Additionally, neighborhoods that are extremely homogeneous in terms of land-use and do not include considerable number of commercial parcels score very low. Hence, Census Tracts that are mainly characterized by primarily industrial land-use or contain large transportation infrastructures (e.g. ports, airports, large train stations) or even large metropolitan parks display limited walkability.

    The results and findings coincide to a satisfactory extent with the results of previous studies. However, the comparison is simple and barely based on easily observed patterns. As a result, the validity of the new Walkability Index might need further assessment due to limitations and lack of data.

    All types of limitations have been identified including limitations in data and in methodology. Suggestions for further research include possible additional parameters that can be employed in our Walkability Indices (e.g. crime rate, and separate parameter for parks and green areas) and further research whether the components of a Walkability Index should be weighted or not. In general, Walkability Indices are promising GIS applications that still need further research and development.

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    agampatian_student_theses
  • 125.
    Agarwal, Tushar
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    The Ganges drainage basin: Hydrological transitions due to anthropogenic water use.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Hydrological changes in catchments world over have affected regional climate and pose serious challenge to future water resource management. The Ganges drainage basin (GDB) is one such region which has undergone rapid transformation in land and water use, more specifically in the latter half of 20th century. GDB has a population of more than half a billion people and is spread across India, China (Tibet), Nepal and Bangladesh. Further, hydrological investigations accounting land and water use changes in GDB are rare. This study is an attempt to resolve hydrological changes in the Ganges basin using the fundamental water balance, focusing particularly on water use changes through irrigation. Between the period 1951-1959 and 1991- 2000, precipitation (P) in the Ganges basin has reduced by 11.25 % while evapotranspiration (ET) has only reduced by 3.61 %. In addition, the ET/P has increased from 0.483 to 0.525 during the same period suggesting a larger partitioning of P towards ET. This suggests greater utilization of P to release water vapor in the atmosphere and thus causing a reduced water flow downstream. With water availability at the fulcrum of future concern for regional and national water security, these findings should encourage policy makers to account for hydrological changes in the GDB in planning sustainable water use.

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    fulltext
  • 126.
    Ageby, Oscar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Sher, Nardin
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Bjälklagselement i håldäck och korslimmat trä: En jämförelsestudie mellan två bjälklagselement2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In society today, the focus is on sustainability, which places high demands on the designer when designing the structural frame for apartment buildings. A large part of the CO2 emissions in the construction process can be traced to the choice of material, where the combustion of lime in the cement industry and the production of steel from iron ore are among the main factors for the emissions.

    This report intends to provide answers to the differences and similarities between two frame systems with different floors slabs; a version in cross-laminated wood, hereinafter referred to as KL-trä (CLTwood), and a version in hollow core slabs. The two objects have been given identical conditions, with a reservation for flooring material, with a steel frame with varying cross-sectional profiles.

    Data for CO2 equivalents and price of each frame material have been examined and compiled in tabular form where the two buildings are evaluated and results are discussed in the analysis part. The result provides an answer as to which element performs best for an office building with two floors with regard to cost and CO2 equivalents for individual profiles compiled for the two buildings.

    Dimensioning of beams has been carried out with regard to bending moment capacity, columns with respect to buckling of concentric pressure force and flat bending buckling with elements of wind load and normal force against columns. Tekla Structures has been used to visualize the frame and FEM-Design20 has been used to verify load counts.

    The financial part of the report refers to costs of the two buildings, which are reported in tabular form with cost per steel and floor profile. The lump sum for each case has been compiled and in the discussion section of this report explanations and conclusions are given to the financial part.

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    fulltext
  • 127.
    Aghili, Ali
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ribac, Haris
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Prediction of early age and time dependent deformations in a massive concrete structure2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The heat development that occurs due to the hydration of cement is important to consider during casting of massive concrete structures. By using computer programs that are based on finite element methods (FEM), simulations can be performed on the heat- and strength development. In this project, a FE program called ConTeSt has been used in order to predict the temperature- and strain development in a massive concrete wall. If the potential risks in a concrete structure are evaluated before casting, economical savings, including a better casting plan could be obtained. The structure under investigation was a concrete wall behind one of the spillways in the hydro power dam of Storfinnforsen. Due to a re-construction of the wall, an opportunity occurred to develop a measurement plan of the casting and perform simulations on the wall.

    A sensitivity analysis was performed in order to investigate the effects on the temperature- and strain development, by varying the cement content, ambient temperature, wind speed and degree of restraint in translation. The results showed, that a higher cement content increased the rate of hydration and hence the temperature in the concrete. Higher wind speeds contributed to more cooling of the concrete which, in some cases, resulted in cracking due to contraction of the material. Cracking due to contraction also occurred when the ambient temperature was decreased. The ambient temperature did not have a significant impact on the rate of hydration, but instead the impact was larger from the initial temperature of the fresh concrete. A higher initial temperature of the fresh concrete increased the rate of hydration, which increased the temperature in the material. The degree of restraint could only be varied in translation in ConTeSt and hence the effect on the strain development was not that significant.

    A crack risk analysis was performed where the developed tensile stresses were compared with the tensile strength of the concrete. The same factors were varied as in the sensitivity analysis. The results showed that the tensile strength was exceeded for most of the cases and thus that the crack risk was high.

    The required equipment, in order to perform the measurements on site, consisted of 7 strain gauges of the module KM-100B from TML Tokyo Sokki Kenkyujo, 2 data loggers of the module Spider-8 from HBM, at least a 25 m ø9 mm 5-core shielded cable and a computer with the software Catman Easy.

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    fulltext
  • 128.
    Agnarsson, Madelene
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Larsson, Marie
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Hjälpmedel vid beräkning av grundvattensänkning för att underlätta prissättning i anbudsfas.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Grundvattensänkningar är något som ofta behöver utföras innan konstruktion av anläggningar i jord. Att sätta pris på en grundvattensänkning är inte särskilt lätt när information eller kompetenser saknas som krävs för att göra en rimlig bedömning. Veidekke Entreprenad Anläggning Öst är ett anläggningsföretag som oftast jobbar i generalentreprenadsform. Vid en generalentreprenad så är projekteringen redan gjord och pris ska sättas på de olika posterna som behöver utföras.

    Denna rapport presenterar en förenklad process för kalkylberäkningar i anbudsfas. Därför har en mall har tagits fram åt Veidekke. Denna mall består av fyra representativa typjordar och ekvationer som gör den användarvänlig. För att kontrollera mallens duglighet så testades den sedan på tre projekt som Veidekke utfört grundvattensänkningar på. Mallens beräknade resultat kunde då jämföras med observerade resultat. Det visade sig att mallen ger en god approximation på hur grundvattensänkningen kan se ut och en fingervisning på hur lång tid det kan ta innan stationär grundvattensänkning uppkommer.

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    fulltext
  • 129.
    Agrawal, Tarun Kumar
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development, Avancerad underhållsteknik och produktionslogistik.
    Kalaiarasan, Ravi
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development, Avancerad underhållsteknik och produktionslogistik.
    Olhager, Jan
    Lund University.
    Wiktorsson, Magnus
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development, Avancerad underhållsteknik och produktionslogistik.
    Understanding Supply Chain Visibility Through Experts’ Perspective: A Delphi Based Approach2021In: Advances in Production Management Systems. Artificial Intelligence for Sustainable and Resilient Production Systems: IFIP WG 5.7 International Conference, APMS 2021, Nantes, France, September 5–9, 2021, Proceedings, Part IV / [ed] Alexandre Dolgui, Alain Bernard, David Lemoine, Gregor von Cieminski, David Romero, Cham: Springer Nature , 2021, Vol. 633, p. 189-196Conference paper (Refereed)
    Abstract [en]

    Visibility in production logistics and across the supply chain has become a key concern for organizations. Its need has been further emphasized due to the current COVID 19 crisis. Organizations find it challenging to prepare the internal logistics and supply chain, and quickly respond to such unexpected events, due to low visibility. Against this backdrop, the paper, which is a work-in-progress, systematically documents different factors influencing supply chain visibility and crucial information that should be collected and shared among supply chain partners for better visibility. A Delphi analysis is being conducted with twenty-six supply chain experts from various globally recognized enterprises with manufacturing units located worldwide. The study starts with a short open-ended questioner to collect a comprehensive list of antecedents, drivers, barriers, effects, and visibility information based on the qualitative response from the experts. The preliminary results from the first round of the Delphi analysis indicate that risk management, environmental sustainability, and supply chain control are some of the key drivers. Lack of IT infrastructure and maturity are some of the barriers, integrated systems, and technology maturity are among the key antecedents and gaining planning capability and better customer service are some of the positive effects of supply chain visibility as per the experts’ opinion. In addition, information related to planning, supplier location, and deviation are among the crucial ones that require the collection and sharing for better supply chain visibility. This research study is among the few that empirically explores factors influencing supply chain visibility and generates new insights as to why the barriers can be difficult to overcome in complex supply chain settings.

  • 130.
    Ahlberg, Fanny
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ökad avbördningskapacitet hos befintliga dammar i Sverige: En fallstudie över damm i mellersta Norrland2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Intresset för klimatförändringar, och problem som kommer med dessa, har ökat de senaste årtiondena. En effekt som dessa drar med sig är att de beräknade extremflödena förväntas öka vilket påverkar säkerheten hos befintliga dammar. Flödesdimensioneringsriktlinjerna, vilket kortfattat är riktlinjer för att bestämma dimensionerande flödet i Sverige, reviderades 2015 till att också ta hänsyn till ett föränderligt klimat. Detta leder till krav på befintliga dammar att öka sin avbördningskapacitet samtidigt som intresset för mindre traditionella utskovsanordningar ökar för att säkerställa tillförlitligheten hos utskoven. Denna studie är en fallstudie över en dammanläggning i mellersta Norrland som på grund av en förhöjd klassificering måste öka sin avbördningskapacitet. Syftet med studien är att föreslå åtgärder på dammen som leder till att avbördningskapaciteten blir i linje med flödesdimensioneringsriktlinjerna och att denna rapport ska kunna användas som stöd och underlag när andra dammar i Sverige har motsvarande utmaning. Åtgärderna togs fram genom att först identifiera möjliga utskovsanordningar med avseende på dammens konstruktions- och geologiska förutsättningar samt driftaspekter i ett svenskt klimat. De fördelaktiga utskovsanordningarna anpassades för den aktuella dammanläggningen och avbördningsberäkningar för möjlig design av utskoven utfördes. De åtgärder som kunde avbörda flöden enligt flödesdimensioneringsriktlinjerna utvärderades med avseende på stabilitet i de fall som ansetts möjliga. Efter en diskussion kring olika för-och nackdelar med de olika åtgärderna, med avseende på bland annat ekonomi, föreslogs möjliga lösningar. De utskovsanordningar som enligt resultatet var fördelaktiga att implementera för dammanläggningen var överfallsutskov, både kontrollerat och okontrollerat, och labyrintutskov. Avbördnings-och stabilitetsberäkningarna samt diskussionen kring för och nackdelar kring åtgärderna ledde fram till att tre åtgärder kunde föreslås. Alla tre alternativen innefattade ytvattenutskov, även kallade överfallsutskov med lucka, och var antingen att bygga om befintliga utskov, bygga till ett ytterligare utskov eller en kombination av de två. Labyrintutskovet visade sig ha ganska hög kapacitet, men uppfyllde inte kravet om klass II-flöde vid dämningsgräns. En generell slutsats som kunde dras av studien var att det finns ganska många olika alternativ på utskovsanordningar, men problem och osäkerheter med igenfrysning, drivgods och kavitation måste kunna hanteras i Svenskt klimat. Okontrollerade utskov kan vara ett alternativ, och då främst labyrintutskov, men det förutsätter att dammen med befintlig avbördningskapacitet kan avbörda klass II-flöde.

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  • 131.
    Ahlberg, Fanny
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Ivansen, Anders
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Analys över variationer i vattenförbrukning och dess påverkandefaktorer: En fallstudie över områden i Borås2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The steady supply of fresh water is, and has always been, one of the most important functions in human societies. Different users have been able to take advantage of this resource in different extents and for different purposes. The major areas for water usage are drinking water, water supply for industrial purposes and the usage in agricultural sector.

    By dimensioning the supply- and sewer systems accordingly to the demand of the users a more sustainable and optimal system can be achieved. A proper dimensioning has six general factors it should to take in consideration. These are the size of the population, water consumption in residents, general water consumption in schools and offices, water consumption in industry, leakage and different water losses. With a background of these factors this reports main focus and purpose is analysing the variation in water consumption for different consumers (such as residential houses or apartment blocks) in different time intervals (in this report during days and years) and in respect to different factors. The factors that has been chosen to be examined is how water consumption depends on mean age of the consumers and the outdoor temperature. To complete this study water consumption data of different areas in Borås has been provided from the Swedish consultant firm Tyréns. Before analysing the data another study was made by Victor Eliasson, which included the revealing of different faults in the provided data. As a result of this study the most reliable data was chosen to further analysis with respect to the chosen aspects. During the project the calculation- and modelling program Matlab was used alongside the chart program excel. These two programs combined made it possible to handle large amounts of data and present it in different graphs and models. Conclusions could later be made by analyses and different statistical methods. The result from the comparison between areas with different mean ages of the residents showed that the area with high mean age (80 years) hade a higher water consumption than the other areas. The variation in water consumption differed as well between the area with the high mean age compared to the other areas. A regression- and correlation analysis between water consumption and temperature was performed to see if water consumption is depending on the outdoor temperature. The function of a regression analysis is to describe the relation between different parameters with a mathematic model (in this study a linear model). A correlation analysis is then performed to tell how well the mathematic model describes the relation. A conclusion could be made that the water consumption tends to increase with increasing temperature during parts of the year, since a correlation could be found during mars to September. The strongest correlation was in general during May and July for all the areas. No conclusion of how the variation i water consumption depends on different consumers could be made for the analysis during a day and a year. In contrast to the parameters that had a correlation with water consumption there was no visible connection between water consumption over a year or day depending on different users. 

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  • 132.
    Ahlberg, Jesper
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Gustafsson, David
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Distributed snow modelling integrating ground penetrating radar data for improved runoff predictions in a Swedish mountain basin2009In: EGU General Assembly 2009, 2009Conference paper (Other academic)
    Abstract [en]

    Operational forecasts of snow melt runoff in Sweden are currently running with precipitation and temperature as the main input variables and calibrated with runoff data, and there is an interest to make better use of new measurement systems for distributed snow data. At the same time, various data assimilation techniques are becoming more frequently used in hydrological modeling, in order to reduce uncertainties related to both model structure errors and errors in input and calibration data. Thus, it is important to address not only what type of snow data that can be used to improve the model predictions, but also what type of input data and model structures that are optimal in relation to the available snow data. The objective of this study is to investigate to what extent the runoff predictions can be improved by assimilation of temporal and spatially distributed snow data, and if the improvements depend on the choice of model structures, for instance the use of energy balance or day-degree snow models. In order to achieve these objectives a new distributed snow model has been implemented into the hydrological modeling framework HYSS/HYPE. This model can easily be setup with either an energy balance model or a day-degree model for the snow pack calculations, and it is easy to run the model with different spatial resolutions. In the fully distributed case, snow drift processes are implicitly included in the model through a precipitation distribution model, based on topographical information and wind direction. The model was applied to a mountain basin in northern Sweden used for hydropower production, where extensive snow measurements were taken during the last two winters 2007-2009. A climate station is located at the outlet of the regulation lake, including automated point measurements of snow depth, snow mass (snow pillow), snow wetness and snow temperature. Distributed snow cover data was sampled using ground-penetrating radar from snow mobiles. Measurements were taken at the time of the maximum snow cover, providing a data set with snow depth, snow density, snow water equivalent along 20 km long transects in representative areas of the basin. The precipitation distribution model was calibrated using the distributed SWE data from the GPR measurements. Application of the calibrated model to previous years without available snow data show that the runoff predictions was improved compared to calibrations without the distributed snow data, however the improvements were larger for the energy balance compared to the day-degree model. Further developments will include assimilation of the temporal and spatial snow data to adjust the distribution of various input variables, for instance air temperature and wind speed.

  • 133.
    Ahlfors, JOhanna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Häggdahl, Josefin
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Framtidens modulskola: En jämförande studie av arbetsmiljön i en tillfällig och en befintlig skolbyggnad2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 134.
    Ahlgren, Lukas
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Instituional Investors Unlisted Real Estate Investments in Sweden – A Study of the AP-Funds’ Performance and Investment Strategies2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Over the past decade, the Swedish pension funds AP1, AP2, AP3, and AP4 have significantly increased their capital allocation towards unlisted real estate. This study explores the investment strategies of these AP funds, examining the methods used in asset class investments, risk mitigation measures, responses to macroeconomic threats, and investment returns. Employing a mixed-methods approach, the research integrates semi-structured interviews with fund representatives and statistical analysis of data from annual reports. 

    Findings indicate that the AP funds have capitalized on post-financial crisis real estate market dynamics, particularly evident in investments initiated in the years after the crisis. Notably, AP1, AP3, and AP4 have gained good returns through sector diversification, contrasting with AP2’s less successful geographic diversification. Investments are primarily direct or joint ventures in unlisted real estate firms, avoiding PERE-funds due to their shorter holding periods and high costs. Risk is mitigated through extended holding periods, strategic partner selection, board involvement, and analysis of megatrends. The low risk-free rate environment that has been in Sweden for the last decade has significantly supported the unrealized returns from the investments. Future capital allocation should focus on non-competing sectors, reinvestments in existing assets, and identification of new trends to enhance sector investability.  

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  • 135.
    Ahlgren, Lukas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Forsberg, Max
    Certifiering av smarta byggnader: En studie om vad i smarta byggnader som går att certifiera med dagens certifieringssystem2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During the last decade, many if not all building certification systems have been formed for the certification of environmental aspects only. The purpose of this study was therefore to examine to what extent environmental certifications take smart solutions into consideration and to see if there was room for a new certification system for smart buildings. Furthermore, the possible need for another certification system for smart buildings was evaluated. The study compared previous research in smart buildings and green buildings in relation with four existing certification systems. An interview was conducted to investigate the possible need for a certification system for smart buildings. The study found that it is possible to certify smart buildings today but primarily in an environmental aspect which leads to a loss of information about the buildings that never reach the market. Additionally, the study concluded that the challenge in smart certifications is to find appropriate measurements and how the implementation itself should be conducted.

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  • 136.
    Ahlgren, Max
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Goldmann, Jacob
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    The Internationalization of Swedish SMEs: how does internationalization affect individual firm’s capital and credit risk structure?2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this master thesis we examine how the level of internationalization, i.e. a firm’s relative exposure to foreign sales, affects individual SMEs in Sweden. Since it is conducted using a data sample with Swedish SMEs its applicability in other countries may vary. The aspects concerned in which the internationalization affects the firm’s structure is limited to the areas of capital structure, credit risk and the factors affecting credit risk. Altman’s Z-score model is employed to approximate a firm’s credit risk and the debt ratio represents the firm’s capital structure. The purpose of the thesis is to increase the knowledge and provide insights on how internationalization affects SMEs in general and in Sweden in particular. Knowledge on how internationalization affects firms is scarce and by this thesis we have extended the known area of the topic and shed light on this relatively unexplored SME aspect. Our hope is that by highlighting differences (and similarities) in credit risk attributes of high and low internationalized firms SMEs this will improve their financial transparency and ease their attracting and access to external sources of capital. To examine the effects of internationalization on Swedish SMEs we have employed statistical techniques, most importantly regression analysis.

    Our study has not only implications for academics, but for all parts that has any interest in efficient credit scoring models and to understand credit risk characteristics and how internationalization affects SMEs. Banks, policy makers and credit rating agencies are constantly pursuing improvements in the efficiency and accuracy of quantifying credit risk by developing credit-scoring models. Banks because they want to minimize credit losses and maximize profitability and policy makers to secure a viable business environment for companies to nurture economic growth, employment, innovation and the country’s competitiveness. The SME segment has received extra attention lately due to the financing barriers they are facing.

    Our results are contradictory to some earlier research in the area and in line with other. This implies that the characteristics and relationship of SMEs credit risk and internationalization changes over time and/or differs between countries, perhaps even between regions within national borders. For example we arrived at the conclusion that our basic model indicates a positive relationship between internationalization and credit risk, in line with both Rugman (2009) and Caves (2007). Our analysis shows no significant difference in the firm’s capital structure depending on the internationalization, although younger companies tended to have a higher level of internationalization. This finding is contradictory to the research conducted by Burgman (2009) and the reports carried out by the European Commission whose report reaches the conclusion that older firms had a higher level of international exposure. 

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  • 137.
    Ahlin, Rikard
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Brinck, Viktor
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Klimatkalkylering2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This is a study on the climate impacts associated with the construction of railway bridges in order to develop key performance indicators such as operation, material and amounts to effectively reduce greenhouse gas emissions. The basis of the study has been work in Trafikverkets tool klimatkalkyl 2.0. It has been reviewed on the basis of ease of use and accuracy of input data and emission conversion factors. That’s because we wanted to see the difference between the model and a unique project. What was different and why?

    This study has concluded that without some care and work in klimatkalkyl 2.0 is a risk of incorrect results. In addition the study demonstrated questionable defaults for significant items. In addition to these results the study found that the most significant parts of the unique projects emissions is reducing the amount of steel and concrete and to find suppliers who can demonstrate low emission factors. With relatively simple measures could the unique projects total carbon emissions be reduced by almost 20%

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  • 138.
    Ahlkvist, Ossian
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Är avloppsreningsverk lämpliga mottagare av backspolvatten från simhallar?2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Swimming pools are used as leisure centers, for sports or as therapeutic rehabilitation, and in Stockholm municipality there are 15 municipal swimming facilities and very many private ones in the form of, for example, hotel pools. A relatively inattentive problem with these pools lies in the chemical reactions that take place in the water. Sodium Hypochlorite reacts in the pool with organic material to form Adsorbable Organic Halides (AOX) and Extractable Organic Halides (EOX). These get stuck in the filter at the plant locally and free chlorine can form additional AOX in the wastewater network. These compounds are harmful for humans and animals to ingest and sometimes even to come into direct contact with. These substances have been studied to bioaccumulate in living organisms and have caused problems such as impaired reproductive capacity and other cell damage. The substances have also been observed to accumulate in dunes in watercourses. These substances that are created then get stuck in the filtration systems that are located locally at the plants due to pressure differences in these. When this happens, the filters need to be backwashed and this generates concentrated contaminated water. 

    In the background, I have examined different kinds of disinfection methods in swimming pools, as well as different ways to treat wastewater of AOX and EOX in treatment plants. This was done to build a good background to the issue at hand of AOX and EOX. 

    In this bachelor's thesis, I have studied how many swimming facilities there are in the catchment area of the Käppalaverket, Bromma treatment plant, and Henriksdal treatment plant. With this information, I have found out how much water is generated by pools at these facilities and supplemented these figures using standard values obtained from managers and estimated from received values. 

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  • 139.
    Ahlroth, Sofia
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Convergent validity test of structural benefit transfer: the case of water qualityManuscript (preprint) (Other academic)
  • 140.
    Ahlroth, Sofia
    KTH, Superseded Departments (pre-2005), Civil and Environmental Engineering.
    Correcting NDP for SO2 and NOx emissions: Implementation of a theoretical model in practice2003In: The Review of Income and Wealth, ISSN 0034-6586, E-ISSN 1475-4991, no 3, p. 425-440Article in journal (Refereed)
    Abstract [en]

    The theoretical and the practical studies in the field of environmental accounting are often two separate lines of work. In this study, we develop an optimal control theory model for adjusting NDP for the effects of SO2 and NOx emissions, and subsequently insert empirically estimated values. The model includes correction entries for the effects on welfare, real capital, health and the quality and quantity of renewable natural resources. In the empirical valuation study, production losses were estimated with dose-response functions. Recreational and other welfare values were estimated by the contingent valuation (CV) method. Effects on capital depreciation are also included. For comparison, abatement costs and environmental protection expenditures for reducing sulfur and nitrogen emissions were estimated. The theoretical model was then utilized to calculate the adjustment to NDP in a consistent manner. The estimated damage value of sulfur is close to the Swedish sulfur tax.

  • 141.
    Ahlroth, Sofia
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Costs and benefits of climate change : a bottom-up analysisManuscript (preprint) (Other academic)
  • 142.
    Ahlroth, Sofia
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Finnveden, Göran
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Ecovalue08-a new valuation method for environmental systems analysis toolsManuscript (preprint) (Other academic)
  • 143.
    Ahlroth, Sofia
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Höjer, Mattias
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Sustainable energy prices and growth: Comparing macroeconomic and backcasting scenarios2007In: Ecological Economics, ISSN 0921-8009, E-ISSN 1873-6106, Vol. 63, no 4, p. 722-731Article in journal (Refereed)
    Abstract [en]

    How do results from the sustainability research world of backcasting relate to the macroeconomic scenarios used for policy evaluation and planning? The answer is that they don't, mostly - they come from different scientific traditions and are not used in the same contexts. Yet they often deal with the same issues. We believe that much can be gained by bringing the two systems of thinking together. This paper is a first attempt to do so, by making qualitative comparisons between different scenarios and highlighting benefits and limitations to each of them. Why are the pictures we get of the energy future so different if we use a macroeconomic model from when using a backcasting approach based on sustainable energy use? It is evident that the methods for producing those two kinds of scenarios differ a lot, but the main reason behind the different results are found in the starting points rather than in the methods. Baseline assumptions are quite different, as well as the interpretations and importance attached to signals about the future. in this paper, it is discussed how those two types of scenarios differ and how they approach issues such as energy prices and growth. The discussion is based on a comparison between Swedish economic and sustainability scenarios. The economic scenarios aim at being forecasts of the future and are used as decision support for long-term policies. But are the assumptions in the economic scenarios reasonable? The sustainability scenarios are explicitly normative backcasting scenarios. They do not take the issue of growth and consumption fully into account. Could they be developed in this respect? The comparison between the scenarios is also used to look closer at the issue of energy prices in a society with sustainable energy use. One of the questions raised is if a low energy society calls for high energy prices. Moreover, the effects of tradable permits versus energy taxes is analysed in the context of how energy use could be kept low in a growing economy.

  • 144.
    Ahlroth, Sofia
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Nilsson, Måns
    SEI.
    Finnveden, Göran
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Hjelm, Olof
    Linköpings universitet.
    Hochschorner, Elisabeth
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Weightning and valuation in environmental systems analysis toolsManuscript (preprint) (Other academic)
  • 145.
    Ahlsten, Anton
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Karlsdotter, Ellen
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Numeriska simuleringar av betongplattor på mark med gradientkrympning och sprickfördelande armering2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Betongplattor på mark är en ofta använd grundläggningsmetod. Trots detta är sprickbildning ett vanligt problem där kraven på maximala sprickvidder ofta inte uppfylls. De sprickor som bildas i plattorna uppkommer bl.a. till följd av dess uttorkning, och då olika fuktförhållanden råder på var sida om plattan utvecklas en krympning som varierar med en gradient över tvärsnittet. Vid dimensionering av armeringen för denna inre last och sprickbildningen den orsakar, finns endast otillräckliga analysermetoder att tillgå i normer. Att analysera det tvång som uppstår vid krympningen är mycket svårt, speciellt då betongen spricker och lastfallet blir statiskt obestämt.

    I detta arbete undersöks sprickbildningen i krympande betongplattor på mark så att noggrannare dimensionering av den sprickfördelande armeringen skall kunna utföras. Analyserna har utförts med numeriska simuleringar i FEM-programmet Atena 2D där ett antal olika plattor med varierande betongklass, armeringsinnehåll och platthöjd undersökts. Arbetet omfattar en jämförelse av de erforderliga sprickfördelande armeringsinnehållen samt de analytiskt beräknade sprickvidder som erhålls dels enligt huvuddokumentet för Eurokod 2 och dels enligt huvuddokumentet och den tyska nationella bilagan. Armeringen har då dimensionerats utifrån en spänningsfördelning som varierar linjärt över tvärsnittet, på samma sätt som krympningen varierar. Studien behandlar även en jämförande undersökning av sprickutvecklingen vid inre respektive yttre last för att påvisa skillnader i sprickbeteendet.

    De numeriska simuleringarna visade att en ökad sprickfördelande förmåga och en minskning av sprickvidder erhålls då armeringsinnehållet i en platta ökas. Av de undersökta plattorna nås armeringens flytspänning inte i något fall, vilket tyder på att mängden armering kan minskas ytterligare utan att s.k. single cracks uppstår. Även vid underarmering, då armeringen minskas till 64 % av vad Eurokods huvuddokument anger, behålls den sprickfördelande funktionen. Undersökningarna visade att den sprickbildning som sker av den inre lasten vid krympning är beroende av uppsprickningen, till skillnad från sprickbildning vid yttre last. Den jämförande studien över armeringsinnehåll enligt Eurokod 2 visar att dimensionering enligt tyska nationella bilagan under verkan av inre last ger en reducerad erforderlig armeringsarea med 20 % i förhållande till huvuddokumentet. De analytiska beräkningarna över sprickvidder tyder på att beräkningsmetoden enligt Eurokod 2 ger större sprickvidder än den som beräknats enligt den tyska nationella bilagan.

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  • 146.
    Ahlund, Rasmus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Ögren, Oscar
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Pore pressures and settlements generated from two different pile drilling methods2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For piling works in sensitive soil, especially in inner city projects, it is essential to be aware of the available methods and to choose the most suitable method to minimize the risk of damaging existing buildings or endanger the workers at the construction site. Down-the-hole drilling of piles is a relatively safe method and can be separated into drilling with air powered hammers and water powered hammers. This study compares water powered drilling with air powered drilling and shows that the impact on the soil generated by air powered drilling is larger than that from water powered drilling.

    A field study was carried out where 4 piles were drilled, two with air powered DTH drilling and two with water powered DTH drilling. The drilling was carried out in clay resting on an approximately 4 m layer of silt and friction soil. The total soil depth was about 12- 15 m. To analyze the soil influence, settlements were measured at ground level and in depth and pore pressure was measured in the middle of the clay layer. This study distinguished two major problems when drilling through this type of soil. The first is the risk of over-drilling in the friction layer. The second problem is the risk of increasing the pore pressure in the clay. Both these problems were experienced when using air powered drilling but for the water powered case only a small pore pressure increase and no over-drilling was observed. In conclusion, drilling with water has less influence on the soil in the sense that it gives a smaller effect on the pore water pressure and causes smaller settlements.

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  • 147.
    Ahmad, Alireza
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Wersäll, Carl
    Peab Anläggning AB, Stockholm, Sweden.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Impact of particle arrangement and model dimensions on DEM modeling of high-speed railway ballasted tracks in 2D and 3D2024In: Transportation Geotechnics, E-ISSN 2214-3912, Vol. 47, article id 101272Article in journal (Refereed)
    Abstract [en]

    Modelling railway projects has a main challenge in the discrete element method (DEM). The granular material of the embankment consists of millions of fine angular particles which are difficult to model due to the long computational time. The long computational time also prevents the modeling of the higher number of loading cycles. As a result, researchers prefer to simulate the project in 2D to accelerate the simulation. While 2D simulations present a seemingly simple option for modeling railways, they tend to oversimplify the intricacies of particle interactions and the distribution of stress. Nonetheless, the extent to which these simplifications affect the authenticity of the simulations has remained ambiguous. In this study, the periodic cell replication method is used to build extensive long railway tracks significantly faster than conventional methods. Then, this DEM model is calibrated against the measurement results of a physical full-scale ballasted track. The model is then used to simulate several railway projects with different initial particle arrangements and model dimensions in both 2D and 3D. The results show that the 2D models are more dependant on the initial particle arrangement which shows different behavior for the same model. In addition, 2D simulations are incapable of reproducing the principal stress rotation in granular layers due to the moving load of the train wheel. As a result, 3D DEM simulations using the periodic cell replication method is suggested for studying the railway tracks.

  • 148.
    Ahmad, Alireza
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Norberg, Karl
    Sweco.
    Emam, Sacha
    Itasca.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    The influence of the rail beam on the settlement ofhigh-speed railway tracks: A discrete element studyManuscript (preprint) (Other academic)
    Abstract [en]

    Modelling railway embankments have two main challenges in the discrete ele-ment method (DEM). First, the granular material of the embankment consistof millions of fine angular particles which are difficult to model due to thelong computational time. As a result, researchers prefer to use spherical orscale-up particles as granular material. Also, it prevents the modeling of thehigher number of loading cycles. Second, the DEM is incapable of includingcontinuous rail beams due to its discrete nature. Therefore, most of the re-search is limited to ignoring the rail beam and other structural elements ofthe track. In this study, a DEM model is calibrated against the measure-ment results of a physical full-scale ballasted track. The model is then used toinvestigate the effect of including the rail beam for high-speed railways sub-jected to 2000 axle passages. The results show that although ignoring therail beam does not substantially affect the results for initial loading cycles,its influence is significant after a couple of hundred axle passages. The modelwithout a rail beam shows more principal stress rotation, more settlement,non-realistic vertical displacement of the sleepers, more particle rearrange-ment and more sleepers’ vibration. Therefore, it is necessary to include therail beam in the long-term analysis of the track to conclude realistic results.

  • 149.
    Ahmad, Arslan
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Evaluation of organic residues and their mixtures with Peepoos to produce fertilizer.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Peepoo, self-sanitising, biodegradable toilet is characterized by low carbon to nitrogen (C-N) ratio and low dry matter (DM) content. Principal nutrients (nitrogen (N), phosphorous (P) and potassium (K)) are also not in a balance as required by most crops. It was expected that the mixing of used Peepoos with other organic materials might balance its chemical characteristics. In this thesis, availability and suitability of common organic materials produced in Kenya has been investigated for mixing with used Peepoo bags to obtain a balanced fertilizer product from the crop nutrition aspect. Seven organic residues were selected from the list of 13 on the basis of their availability near the processing site in Nairobi. The selected residues were then chemically analyzed for their individual plant nutrient content. The analysis results were used subsequently to simulate the chemical composition of a wide range of Peepoo-Residue mixtures. The evaluation of the theoretical mixtures based on DM content, C-N ratio and NPK ratio showed that the majority of investigated mixtures had DM content below 60 %. Majority of the mixtures showed C-N ratio between 10-1:1. All the mixtures deviated from the common nutrient uptake ratio of crops (1:0.5:1.4). Composite mixtures with more than 2 ingredients resulted in a balanced fertilizer product. The study concludes and recommends that the composite mixtures with more than two ingredients should be considered for practical processing of Peepoos into a commercial fertilizer product.

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  • 150.
    Ahmad, Roman
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Chammoun, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Optimering av den svenska metoden fördimensionering av betongbeläggningar på flygfält2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sverige har länge använt beläggningsytor av asfalt på grund av dess flexibla

    egenskaper som är lämpliga för det svenska klimatet. Historiskt sett har Sverige

    haft låg trafikmängd vilket inte gett utrymme för utvecklingen av betong som

    beläggning i vägar.

    Trafikmängden har sedan ett par år tillbaka ökat markant och det kan därför hända

    att det kommer att byggas betongvägar i huvudleder. Emellertid är erfarenheten i

    Sverige så pass låg att utveckling av nuvarande metoder fordras. USA har länge

    brukat betongvägar i stor skala och har betydligt större mängd betongvägar i

    motsats till Sverige, som har mindre än 1 %. Den ökade trafikmängden speglas

    även på flygplatser.

    I den här studien jämförs den svenska dimensioneringsmetoden för

    betongbeläggning på flygfält (Strand, 2016) med den amerikanska

    dimensioneringsmetoden i syfte att optimera den svenska metoden.

    Den svenska dimensioneringsmetoden (Strand, 2016) som denna studie behandlar

    är förenklad och baserad på gamla teorier. Metoden framställs genom äldre

    litteraturstudier men kombineras även med aktuell litteratur. Den amerikanska

    metoden används genom dess egna datorprogram kallad FAARFIELD där alla

    beräkningar görs med hänsyn till dess normer och krav.

    Dimensioneringen sker för lasten från Airbus A380 med 365 avgångar per år

    enligt Swedavias förväntningar. Oarmerade betongplattor med 350 till 450 mm

    tjocklek med betongkvaliteten C35/45 klarar inte av utmattningskriteriet. Däremot

    klarar likadana plattor med betongkvalitén C60/75 utmattningskraven och

    fungerar utmärkt som beläggning på uppställningsplatser och rullbana. Vid

    dimensionering enligt den amerikanska metoden visar resultaten att plattorna blir

    både tjockare och tunnare än den svenska metoden beroende på vilken

    betongkvalite som används.

    Den svenska metoden förutsätter en del förenklingar vid dimensionering av

    betongbeläggningar och därför blir inte beräkningen helt korrekt. Resultaten som

    denna studie visar är därför preliminära. Optimering av den svenska

    beräkningsgången är ett steg i rätt riktning men det praktiska utförandet av arbetet

    och erfarenheten av detta är något som måste byggas ut för en fulländad och

    fungerande metod i praktiken.

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    fulltext
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