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  • 1.
    Abdou Mahmoud, Amir
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Dahlqvist, Ted
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Ånghuvud för steamer2010Independent thesis Advanced level (degree of Master (Two Years)), 5 poäng / 7,5 hpOppgave
    Abstract [sv]

    Följande examensjobbs rapport bygger på examensjobbskursen i CAD-teknikerprogrammet årskurs två.

     

    Arbetet som rapporten bygger på är utfört i samarbete med Hafa badrum i Halmstad. Arbetet innefattar utvecklingen av ångmunstycke för steamrar, en slags ångdusch som är en blandning av ångbastu samt dusch. Skälet bakom utvecklingen är att passa in ångmunstycket med Hafas övriga design, samt att försöka få så lite överskottsvatten som möjligt.

     

    Det kom fram en gemensam idé att integrera ångmunstycket, under ett möte med Hafa, som sedan spann vidare och blev den första prototypen.

     

    Prototypen visade sig vara lyckad, även om skydd för ångan var tvunget att tillverkas då den kom ut för starkt i duschen, främst då lite spillvatten skapades och för att prototypen endast hade en tredjedel av materialmängden jämfört med den modell Hafa har idag.

     

    Metoden som följdes var den samme som användes av oss i princip-, primär-, och tillverkningskonstruktions kurserna.

  • 2.
    Abid, Ali
    et al.
    Mälardalens högskola, Institutionen för innovation, design och produktutveckling. Mälardalens högskola, Akademin för innovation, design och teknik.
    Roback, Joel
    Mälardalens högskola, Institutionen för innovation, design och produktutveckling.
    Produktutveckling för Cate & Nelson Design: Framtagning av möbel2008Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Denna rapport behandlar examensarbete utfört för industridesignföretaget Cate & Nelson Design. Företaget ligger i Eskilstuna och jobbar i huvudsakligen med möbeldesign och inredningsprodukter. Projektgruppensuppgift har varit att ta fram en ny möbel för företaget och arbetet har omfattat utveckling av hela produkten från idé till prototyp.

  • 3.
    Abrahamsson, Lena
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Kaplan, Alexander
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Produkt- och produktionsutveckling.
    Johansson, Jan
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Rask, Kjell
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Fältholm, Ylva
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Arbetsvetenskap.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Bergquist, Bjarne
    Projekt: LUPO - globala länkar2010Annet (Annet (populærvitenskap, debatt, mm))
  • 4.
    Abrahamsson, Sten
    et al.
    Högskolan på Gotland, Institutionen för humaniora och samhällsvetenskap.
    Isaksson, Raine
    Högskolan på Gotland, Institutionen för humaniora och samhällsvetenskap.
    Implementing Lean: Discussing Standardization Versus Customization with Focus on National Cultural Dimensions2012Inngår i: Management and Production Engineering Review, ISSN 2082-1344, Vol. 3, nr 4, 4-13 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lean or Toyota Production System (TPS) has more or less successfully been implemented in the Western world’s businesses and organizations for the past 20 years. Several authors have discussed what it is that creates a successful implementation, and several studies have been presented where strategies for implementations have been studied. Culture’s impact and possible mitigation for Western companies have been studied and described by for example Womak & Jones. Proponents of the concept of Lean argue that culture is not a constraint for implementation of Lean. Lean Management is called a philosophy but it is often used as a change strategy in the sense that it is implemented with the view of improving performance. A change strategy could be seen as a product that might have to be customized with the view of improving the effectiveness of the implementation. On the other hand abandoning a standardized approach comes with the risk of severely altering the change strategy, possibly to its detriment. Implementing Lean will have an effect on the company culture. Does it make any sense customizing the implementation to culture if the issue is changing the culture? The purpose of this paper is to highlight and discuss the balance between a customized implementation and a standardized implementation. Which are the main arguments for standardization and customization and how could these be reconciled? A literature study of Lean implementation has been carried out and compared with Lean principles and theories from change management with focus on change drivers and change barriers. Main drivers of Hofstede’s national cultural dimensions are compared with Lean principles to identify possible drivers and barriers in different cultures. The theory synthesis on drivers and barriers is subjected to a first test in a case study on Lean implementation according to a standardized approach. The implementation is made in a small Swedish factory belonging to a worldwide industrial company. Results from the literature review and the case study indicate that both customization and standardization are needed.

  • 5.
    Abrahamsson, Sten
    et al.
    Gotland University.
    Tosteby, Jonas
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för process- och produktutveckling.
    Isaksson, Raine
    Gotland University.
    Integrated Management Systems: testing a model for integration2011Inngår i: 14th Toulon-Verona Conference: Organizational Excellence in Service. Conference Proceedings / [ed] Jacques Martin & Claudio Baccarani., Alicante: University of Alicante , 2011, 22-35 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Management systems are widely used for creating order, minimising risks and for assuring performance. Management systems are in many occasions integrated since this has been found to be beneficial. In this paper a model for a fully integrated management system (IMS) based on the three axes of level, extent and scope of integration is tested for relevance. The studied system permits the integration of all relevant process dimensions. The research is only in a pilot stage, but the initial results are promising and indicate that there are advantages in using the process view as a base for identifying critical aspects to be managed. A review of the current situation for system integration is studied and the model is subjected to some tests using Sweden as a case. The background study shows that system integration still is limited, especially when comparing with a fully integrated IMS. The feedback from the organisations interviewed is positive and supports continued work with development of the model.

  • 6.
    Adle, Tobias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Matematiska institutionen.
    Framtagning av metod för analys av livslängdsdata2017Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    Husqvarna AB has as of today an extensive research and development department.This department serves to control the active product as well as the upcoming ones.The way that is done is through two different sets of tests. The first one being a longterm endurance test with aimed to unveil the durability of a product. Second and finalsort of test is a more one dimensional one. The aim is to determine different specificunits of interest like for example Newton (N).

    Today the R&D department has a great knowledge within normal distributed data andsomewhat less when it comes to the opposite, so called none normal distributed data.When endurance is of interest the likelihood of that to be of the latter sort is morecommon than not. For now no complete method has been appointed to make iteasier to process a situation of this kind. Studying ever unique case individually, bylooking at the data, has been the way to go. This causes an inconsistency in theanalysis and makes it purely based on which individual that has done it. Lastly it mayalso, unintentionally, ignore the large picture of how a product has progressed.

    To solve these problems this thesis work was put together to propose and conduct amethod. To form this method was an ongoing process throughout the whole thesisperiod. Ideas and thoughts were put forward to be reviewed and discussed. After aseries of tweaks to steer it towards the overall goal the method was finalized. Themethod that was put forward was firmly tested. Also a wide laboration in what themethod actually meant was done.

    The result was a method to be applied on none normal distributed data. This methodhas three parts. The first being the report where everything is embraced. The secondpart is a short manual for an operator to use. Last part is an example where themethod is put to use.

  • 7.
    Ahlman, Per-Arne
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Maskinkonstruktion.
    Smörjning Av Lager2009Independent thesis Basic level (university diploma), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    The work thesis was performed at Assalub a company which is situated in Åtvidaberg. The company works with developing, manufacturing and marketing equipment for handling of lubricants for light and heavier industry. The work thesis it is based on a inquiry Assalub got from MacGregor which is a company within cargo solution, from port to offshore system.

    For unloading grain and other material from the ship cargo it is used combined inlet feeder and screw conveyor, there the inlet feeder is drilling down through the cargo and feed the screw conveyer with material to further destination. At the bottom of the screw conveyer and the inlet feeder there is a bearing that keep the parts together. However the lubrication of the bearing must be made manually. Until now the bearing was lubricated manually through a grease nipple from the bottom of the drill once a day.

     

    The purpose of the thesis was the construction of a lubricating system namely a pump with a grease container which should be placed inside the space of the screw conveyer, so the bearing will be continually lubricated and able to work several days without any stoppage.

    After receiving drawings and operating data for the screw conveyer, the details for the construction was designed in CAD system Solid Edge. The solid mechanics calculations on the weakest point on the construction was made by hand and afterwards the drawings for respectively details was made.

    The construction was completed, but because of the time limit for this work thesis, the manufacturing, mounting and testing were not included in these weeks. The grease containers capacity is approximately seventy-two hours, although desirable should be up to seven days. According to the solid mechanics calculations, the construction should have no problem to resist the stresses it would be exposed to.

    Since this is a prototype there is probably some adjustments and improvements to do, but the estimating is that the system should work properly as it is now.

  • 8. Ahmadi, Alireza
    et al.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Söderholm, Peter
    Risk of operational consequences of aircraft system failure2010Inngår i: International Journal of Pedagogy, Innovation and New Technologies, ISSN 0973-1318, E-ISSN 2392-0092, Vol. 6, nr 2, 149-158 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this paper is to describe a methodology for identifying different operational consequences and associated costs caused by aircraft system failure, in order to facilitate and enhance the capability of taking correct and efficient decisions when analyzing the cost-effectiveness of maintenance tasks. The paper focuses on the operational consequences of failures that lead to delay. To identify the operational consequences of aircraft system failures, Empirical studies of possible scenarios involving aircraft failures and their operational consequences for a commercial airline have been performed. Empirical data were extracted through document studies and interviews, guided by the application of an Event Tree Analysis (ETA). In order to effectively utilize the knowledge of field experts in the assessment process, a pairwise comparison technique was adopted for quantifying the contribution of different factors to the operational. The work was performed together with experienced practitioners from both an aircraft manufacturer and commercial airlines, which contributed to a continuous verification of the outcome of the study.The study shows that the proposed methodology based on ETA and pairwise comparison can be used to identify and quantify the cost of operational consequences of failures in aircraft operation, when there is no sufficient and reliable data.

  • 9.
    Ahxner, Johan
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Industriell organisation och produktion.
    Axklo, Samuel
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Industriell organisation och produktion.
    Införande av Lean Administration i utfallsprovsprocessen2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Detta examensarbete handlar om införande av Lean Administration i administrativa stödprocesser. Examensarbetet undersöker hur Leanverktyg kan bidra till att standardisera dokument och dokumenthanteringen och därigenom eliminera slöserier. Parallellt erhålls kvalitetssäkring och effektivisering, samt att kapacitet frigörs till värdehöjande aktiviteter. Studiens fokus och tyngdpunkt beträffande empirin bygger på aktionsforskning bedriven hos ett tradingföretag där den stödjande dokumenthanteringen till arbetet med utfallsprover studerats närmare.

    Bakgrunden till studien kan härledas till den globala konkurrensen som medfört att fler företag i större omfattning arbetat med att förbättra och effektivisera sin verksamhet. Fler företag har även valt att fokusera på sin kärnkompetens och har därför outsourcat delar av sin verksamhet. I linje med denna utveckling har nya aktörer uppkommit som specialiserat sig på andra områden än produktion. För dessa företag som inte har någon produktion att effektivisera blir fokus istället riktat mot att förbättra andra områden, så som administrationen.

    Syftet med examensarbetet är att, baserat på Lean Administration, ge förslag på ny dokumenthantering för de administrativa stödprocesserna tillhörande utfallsprover. Resultatet av arbetet mynnar ut i ett förslag som presenteras i form av en mall skapad i Excel. Excelmallen har upprättats under examensarbetes gång och är byggd med stöd av principer och verktyg från Lean Administration. Mallen är tänkt att ersätta befintliga dokument i den administrativa stödprocessen och bidrar därmed till att standardisera och effektivisera arbetet med utfallsprover. Mallen bidrar även till valmöjligheter att bemöta kundernas olika krav samt höjer kvalitén genom inbyggd felsäkring.

    Mallen kan anses generell och möjlig att implementera på olika företag som arbetar med utfallsprover. Den grafiska layouten kan dock behöva förändras för att anpassa dokumenten till företagsspecifika behov.

    Under arbetets senare fas uppkom tankar om att vidareutveckla Excelmallen till ett totalkvalitetsdokument, vilket då skulle innehålla all information om en specifik artikel som härrör kvalité. Denna tankegång ger uppslag till vidare utvecklings och förbättringsarbete.

    Förslag ges till vidare forskning inom området Lean Administration då ämnet har mycket kvar att utforska. Arbetssättet som använts i detta examensarbete, att granska arbetsmomenten med Leanglasögon, kan generaliseras och tillämpas även inom andra områden än processen med utfallsprover.

  • 10. Akersten, Per-Anders
    et al.
    Klefsjö, Bengt
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Dependability management as a management system based on core values, methodologies and tools2001Inngår i: Safety and reliability: towards a safer world : proceedings of the European Conference and Reliability, ESRel 2001, Torino, Italy 16 - 20 September / [ed] Enrico Zio ; Micaela Demichela; Norberto Piccinini, Torino: Politecnica , 2001, 245-252 s.Konferansepaper (Fagfellevurdert)
  • 11.
    Alamerison, Seif
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Tarek, Karzan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Samverkanspelare i icke bärande fasadelement2009Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    Abstract

    The tests work is about the subject "synergism of steel and concrete."

    The construction sector is in a strong competition and the different companies in the Prefab

    Market has ever tried to develop new design solutions that are efficient and environmentallyfriendly.

    The purpose of this report is to highlight different aspects of interaction and size up a columndimension and to examine its efficiency and load capacity as Eurocode 3 and Eurocode 4. A sizing chart that describes the relationship between the torque and normal force shouldalso be made of the interaction .

     

  • 12.
    Alexandra Markovic, Markovic
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Maskinteknik.
    Arvid, Edforss
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Maskinteknik.
    An evaluation of current calculations for safety stock levels2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 13.
    Almimi, Ashraf A.
    et al.
    NASA Langley Research Center, Hampton.
    Kulahci, Murat
    Informatics and Mathematical Modeling, Technical University of Denmark, Lyngby.
    Montgomery, Douglas C.
    Division of Mathematical and Natural Sciences, Arizona State University, Department of Industrial, Systems and Operations Engineering Arizona State University.
    Checking the adequacy of fit of models from split-plot designs2009Inngår i: Journal of QualityTechnology, ISSN 0022-4065, Vol. 41, nr 3, 272-284 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the main features that distinguish split-plot experiments from other experiments is that they involve two types of experimental errors: the whole-plot (WP) error and the subplot (SP) error. Taking this into consideration is very important when computing measures of adequacy of fit for split-plot models. In this article, we propose the computation of two R2, R 2-adjusted, prediction error sums of squares (PRESS), and R 2 -prediction statistics to measure the adequacy of fit for the WP and the SP submodels in a split-plot design. This is complemented with the graphical analysis of the two types of errors to check for any violation of the underlying assumptions and the adequacy of fit of split-plot models. Using examples, we show how computing two measures of model adequacy of fit for each split-plot design model is appropriate and useful as they reveal whether the correct WP and SP effects have been included in the model and describe the predictive performance of each group of effects.

  • 14.
    Almimi, Ashraf A.
    et al.
    NASA Langley Research Center, Hampton.
    Kulahci, Murat
    Arizona State University, Tempe.
    Montgomery, Douglas C.
    Division of Mathematical and Natural Sciences, Arizona State University, Arizona State University, Tempe.
    Follow-up designs to resolve confounding in split-plot experiments2008Inngår i: Journal of QualityTechnology, ISSN 0022-4065, Vol. 40, nr 2, 154-166 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Split-plot designs are effective in industry due to time and/or cost constraints, restriction on randomization of the treatment combinations of the hard-to-change factors, and different sizes of experimental units. Some of the results of fractional factorial split-plot experiments can be ambiguous and a need may arise to conduct follow-up experiments to separate effects of potential interest by breaking their alias links with others. For completely randomized fractional factorial experiments, methods have been developed to construct follow-up experiments. In this article, we extend the foldover technique to break the alias chains of split-plot experiments. Because it is impractical or not economically possible to foldover the whole-plot factors, as their levels are often hard or expensive to change, the focus of this article is on folding over only one or more subplot factors in order to de-alias certain effects. Six rules are provided to develop foldovers for minimum aberration resolution III and resolution IV fractional factorial split-plot designs.

  • 15.
    Al-Najjar, Basim
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    Determination of potential failure initiation time using cumulative sum chart2016Inngår i: IFAC-PapersOnLine / [ed] Christos Emmanouilidis, Benoît Iung, Marco Macchi and François Pérès, Elsevier, 2016, Vol. 49:28, 43-48 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hard competition forces companies to reduce uncertainty in production planning through, e.g. reducing the probability of failures. In this paper, more accurate data analysis through reducing randomness in vibration measurements is introduced. Quality control tool Cumulative Sum (Cusum) Chart is adapted for monitoring variation in vibration level to determine the time of potential failure initiation. The result confirms the possibility of reducing false alarms arise due to randomness in vibration signals. The major conclusion; applying Cusum chart it is possible to determine the time of initiation of a potential failure for follow up its progression and accurate planning of maintenance.

  • 16.
    Al-Najjar, Basim
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    En metod och en apparat för att prediktera tillståndet hos en maskin eller en komponent hos maskinen: PreVib algorithm2014Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Ett ändamål med föreliggande uppfinning är att förbättra prediktionen av en tillstånds­övervaknings­parameter och därmed förbättra uppskattningen av den mest effektiva tidpunkten för att byta ut eller utföra underhåll på en maskin eller viktiga komponenter hos maskinen.

    Mätdata som används för predikteringen renas på ett sådant sätt att en optimal prediktering uppnås. Om någon del av maskinen är skadad borde mätningarna öka eftersom skadan i maskin­komponenten är irreversibel, d.v.s. den kan inte laga sig själv, vilket borde medföra att värdena på mätningarna inte kan minska över tiden. De utvalda värdena sparas i ett rörligt fönster anpassat att spara ett förutbestämt antal mätvärden.

    Predikteringen börjar när värdet av den uppmätta tillstånds­övervaknings­parametern har överstigit en potentiell skadenivå, d.v.s. skada har initierats, vid vilken det antas att en potentiell skada hos maskinen eller komponenten är initierad. Det förväntade värdet bestäms baserat på ett fördefinierat mönster som reflekterar ett förväntat beteende hos den övervakade parametern efter det att skada har initierats, och tiden som har förflutit mellan tidpunkten när mätningen utfördes och tidpunkten när övervakningsparametern översteg den potentiella skadenivån. Mätvärdena måste på så sätt uppfylla två olika villkor för att de ska tillåtas att sparas i det rörliga fönstret. 

    Predikteringen utförs baserat på mätvärden som sparas i det rörliga fönstret, dvs. som är renade från störningar. På så sätt förbättras predikteringen.

    På grund av det faktum att mätdata renas också under den första fasen är det möjligt att starta prediktionen baserat på mätvärdena som sparats i det rörliga fönstret så fort som värdet på övervakningsparametern har passerat den potentiella skadenivån. På så sätt baseras prediktionen på mätvärden sparade under den första fasen såväl som under den andra fasen.

    Tack vare reningen av mätvärdena minskas antalet nödvändiga mätningar för att åstadkomma en tillräckligt bra prediktering. Det är tillräckligt med tre mätvärden som har renats enligt uppfinningen för att få ett tillförlitligt resultat.

    Enligt en utföringsform av uppfinningen är det fördefinierade mönstret för tillstånds­övervaknings­parametern en kurva som börjar öka vid tidpunkten då övervaknings­parametern överstiger den potentiella skadenivån. Kurvan beskriver värdet hos övervaknings­parametern i förhållande till tiden som har förflutit sedan tidpunkten då övervakningsparametern översteg den potentiella skadenivån. Formen på mönstret och således på kurvan beror t.ex. på typen av parameter, typen av skada, t.ex. ett brott eller slitage, och typen av förslitningssprocess, maskinens last och hastighet, och typen och kvalitén hos maskinen eller komponenten. För många typer av fel är kurvan exponentiellt ökande. Kurvan bestäms t.ex. baserat på föregående värde för samma tillståndsövervakningsparameter för samma eller liknade typer av maskiner eller komponenter. Kurvan börjar vid samma tid som det har detekterats att en skada har initierats, d.v.s. vid den tidpunkten då övervakningsparametern överstiger den potentiella skadenivån, och kurvan ökar under hela den andra fasen. Det förväntade värdet av mätningen bestäms baserat på kurvan och tidpunkten för mätningen. På sätt är det lätt att bestämma det förväntade värdet på mätningen.

    Enligt en utföringsform av uppfinningen slängs det nya mätvärdet om mätvärdet avviker från det förväntade värdet med mer än ett gränsvärde, gränsvärdet kan vara förutbestämt eller beräknas dynamiskt under den andra fasen.

    Enligt en utföringsform av uppfinningen innehåller mätmetoden vidare: ett meddelande till användaren genereras för att kontrollera mätningen och tillhandahålla ett nytt mätvärde när man har upptäckt att mätvärdet avviker för mycket från det definierade mönstret, ett nytt mätvärde tas emot och det nya mätvärdet jämförs med det förväntade värdet som har bestämts i enlighet med det definierade mönstret för tillstånds­övervaknings­parametern, och en varning genereras om det nya mätvärdet också avviker för mycket från det förväntade värdet. I annat fall byts det äldsta av de sparade mätvärdena i det rörliga fönstret ut mot det nya mätvärdet. En ny mätning utförs om värdet på mätningen avviker för mycket från det förväntade värdet under den andra fasen. Alternativt tas ett nytt mätvärde automatiskt när det har detekterats att en mätning avviker för mycket från det förväntade värdet. I och med denna utföringsform kastas ett felaktigt mätvärde och ersätts med en ny förslitningsrelevant mätning. Om den nya mätningen också avviker för mycket från det förväntade värdet genereras en varning till användaren. Det kan antigen betyda att någonting är fel med mätutrustningen eller att skadan har utvecklats mycket fortare än förväntat och att en underhållsåtgärd brådskande behöver utföras.

    Enligt en utföringsform av uppfinningen innefattar metoden vidare: den predikterade nivån hos tillstånds­övervaknings­parametern jämförs med åtminstone ett gränsvärde för tillstånds­övervaknings­parametern, de föregående stegen upprepas åtminstone tills den predikterade nivån hos tillstånds­övervaknings­parametern överstiger gränsnivån och ett meddelande genereras avseende en underhållsåtgärd när den predikterade nivån hos tillstånds­övervaknings­parametern överstiger gränsnivån. Gränsnivån är t.ex. en varningsnivå som ligger nedanför utbytesnivån för komponenten eller maskinen. Det är också möjligt att ha flera gränsnivåer mellan den potentiella skadenivån och en utbytesnivå. Denna utföringsform gör det möjligt att föreslå en underhållsåtgärd med tillräcklig ledtid vid en kostnadseffektiv tidpunkt.

    Enligt en utföringsform av uppfinnen är maskinen en roterande maskin och mätvärdena någon av vibrationsmätningar, temperaturmätningar, ljudmätningar och chockpulsmätningar.

    Enligt en annan aspekt av uppfinningen uppnås detta ändamål av en datorprogramprodukt direkt nedladdningsbar i det interna minnet hos en dator, eller genom en fjärrstyrd dator, web-service, eller molntjänst innefattande mjukvara för att utföra stegen hos metoden när nämnda program körs på datorn.

    Enligt en annan aspekt av uppfinningen uppnås detta ändamål av ett dataläsbart medium som har ett program inspelat, där programmet får datorn att utföra stegen i metoden när programmet körs på datorn.

    Enligt en annan aspekt av uppfinningen uppnås detta ändamål av en apparat.

  • 17.
    Al-Najjar, Basim
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    Algabroun, Hatem
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    A Model for Increasing Effectiveness and Profitability of Maintenance Performance: A Case Study2016Inngår i: Proceedings of 2016 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (QR2MSE 2016) 2016 World Congress on Engineering Asset Management (WCEAM2016), Institute of Reliability Engineering , 2016, 1-7 s., QR2MSE2016 & WCEAM2016-0003-0038Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In today’s market, companies strive to achieve the competitive advantages. Failing in achieving these goals could threaten the companies’ existence. Failures in the operative level impact negatively on achieving these goals. In order to record these failures for better actions planning, special systems are often used for counting the number of failures, registering the duration of machines downtime and uptime for assessing the total downtime and classifying problems/failures in categories that are decided in advance. These categories can be Electrical, Electronic, Hydraulic, Mechanical, Pneumatics, Human error, and Miscellaneous. In this study, we develop a model to break down the contents of a company/machine failure databases, prioritize failures, assess economic losses due to failure impact on the competitive advantages and suggest a method of how maintenance actions should be rank-ordered cost-effectively. The model is tested using real data. The major results showed that losses aremainly due to two categories i.e. “Bad quality“ and “Less profit margin”, where failures of “Gear”, “Bearing” and “Raw materials quality” cause most of the losses. It is concluded that this model enables the user to quickly identify and prioritize maintenance and improvement efforts cost-effectively.

  • 18.
    Al-Sahli, Firas
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Ibrahimson, Maria
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Delaktighetens förutsättningar och begränsningar i förbättringsarbetet2016Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Delaktighet är en viktig aspekt i förbättringsarbetet. Delaktighet höjer kvaliteten och skapar förankring hos medarbetarna och är ett hjälpmedel att erhålla ett framgångsrikt kvalitetsarbete. Verksamheterna behöver dock förutsättningar för att skapa delaktighet. I framgångsrika organisationer karaktäriseras framgången av delaktighet skapandet och motivation hos medarbetarna. Syftet med studien var att beskriva hur produktionsledare kan skapa möjlighet till delaktighet i förbättringsarbetet. Metoden som användes var kvalitativ induktiv ansats ur ett livsvärldsperspektiv. Djupintervjuer utfördes med åtta produktionsledare och kvalitativ innehållsanalys användes för att granska texterna med syfte att finna meningsenheter och kategorier. Fiskbensdiagram utfördes som ett komplement till intervjuerna. Resultatet och analysen visade på två kategorier, förutsättningar och begränsningar i skapandet av delaktighet i förbättringsarbetet. Resultatet visade i sin tur på att det finns svårigheter att tolka begreppet delaktighet och än svårare att konkretisera de verktyg som används. Det finns ett värde av ytterligare forskning kring delaktighet skapandet i framtiden.

  • 19.
    Andersson, Andreas
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    Andersson, Anders
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    Kostnadseffektivisering av bärcylinder2007Independent thesis Basic level (professional degree), 15 poäng / 22,5 hpOppgave
    Abstract [sv]

    Rapporten avser ett examensarbete inom maskiningenjörsprogrammet vid Karlstad universitet, uppdragsgivaren är Metso Paper Karlstad AB.

    Metso Paper tillverkar tissuemaskiner för pappersindustrin och utför även service samt utveckling av dessa produkter. Tissue är mjukpapper och med detta avses hygienpapper och servetter. Fokus i uppgiften var att kostnadseffektivisera bärcylindern, vilken är en ingående komponent i tissuemaskinen. Bärcylindern är en vals som sitter monterad i slutet på maskinen, i det område där det färdiga papperet rullas upp på spolar. De analyserade objekten har dimensionerna; diameter 900mm med längden 2825mm samt diameter1100mm med längden 5550mm.

    Inledningsvis analyserades bärcylinderns huvudfunktioner, vilka kan sammanfattas:

    • Att med vakuum transportera spetsen (smal pappersbana) från spetsblåsningsrännan till anläggningsytan mellan bärcylinder och upprullningsspole.

    • Att stödja pappersbanan under upprullning på spole.

    • Att skapa ett anläggningstryck mot upprullningsspolen så att ett drivande moment uppstår. Moment krävs då upprullningsspolen saknar drivning.

    Uppgiften delades in i två delar för ett enklare tillvägagångssätt, ”nykonstruktion” samt ”förbättring och effektivisering av befintlig konstruktion”

    Nykonstruktion behandlar hållfasthetsberäkning av godstjocklek samt val av alternativa material. Förbättring och effektivisering berör hur den nuvarande konstruktionen kan förenklas och tillverkningsprocessen förbättras. Resultatet påvisar att dagens konstruktion är onödigt överdimensionerad, godstjockleken kan reduceras med bibehållna funktionsegenskaper. Att tillverka mantel i stål istället för gjutgods ger lägre inköpskostnad av material för bärcylinder i diameter 900mm, vid inköp av två mantlar på en gång halveras nästan materialkostnaden.

    För att kunna effektivisera den befintliga konstruktionen och tillverkningsprocessen måste vissa delar av gjutningen utföras med högre noggrannhet, kriterier såsom: godstjocklek, rundhet samt närvaro av restprodukter bör beaktas. Detta för att effektivisera den efterföljande skärande bearbetningen.

    Slutgiltigen finns stor potential att kostnadseffektivisera denna produkt med en kombination av dimensionering, materialval samt effektivare bearbetningsprocess.

  • 20.
    Andersson, Andreas
    et al.
    KTH, Tidigare Institutioner, Mekanik.
    Malm, Richard
    KTH, Tidigare Institutioner, Mekanik.
    Measurement evaluation and FEM simulation of bridge dynamics2004Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The aim of this thesis is to analyse the effects of train induced vibrations in a steel Langer beam bridge. A case study of a bridge over the river Ljungan in Ånge has been made by analysing measurements and comparing the results with a finite element model in ABAQUS. The critical details of the bridge are the hangers that are connected to the arches and the main beams. A stabilising system has been made in order to reduce the vibrations which would lead to increased life length of the bridge.

    Initially, the background to this thesis and a description of the studied bridge are presented. An introduction of the theories that has been applied is given and a description of the modelling procedure in ABAQUS is presented.

    The performed measurements investigated the induced strain and accelerations in the hangers. The natural frequency, the corresponding damping coefficients and the displacement these vibrations leads to has been evaluated. The vibration-induced stresses, which could lead to fatigue, have been evaluated. The measurement was made after the existing stabilising system has been dismantled and this results in that the risk of fatigue is excessive. The results were separated into two parts: train passage and free vibrations. This shows that the free vibrations contribute more and longer life expectancy could be achieved by introducing dampers, to reduce the amplitude of the amplitude of free vibrations.

    The finite element modelling is divided into four categories: general static analysis, eigenvalue analysis, dynamic analysis and detailed analysis of the turn buckle in the hangers. The deflection of the bridge and the initial stresses due to gravity load were evaluated in the static analysis. The eigenfrequencies were extracted in an eigenvalue analysis, both concerning eigenfrequencies in the hangers as well as global modes of the bridge. The main part of the finite element modelling involves the dynamic simulation of the train passing the bridge. The model shows that the longer hangers vibrate excessively during the train passage because of resonance. An analysis of a model with a stabilising system shows that the vibrations are damped in the direction along the bridge but are instead increased in the perpendicular direction. The results from the model agree with the measured data when dealing with stresses. When comparing the results concerning the displacement of the hangers, accurate filtering must be applied to obtain similar results.

  • 21.
    Andersson, Ann-Christine
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Kvalitetsteknik. Linköpings universitet, Tekniska högskolan.
    Olheden, Anna
    Landstinget i Kalmar län.
    Patient participation in quality improvement: managers’ opinions of patients as resources2012Inngår i: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 21, nr 23-24, 3590-3593 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study was to investigate managers’ opinions of how to take advantage of patients as resources in quality improvement work in the Swedish healthcare sector.

  • 22.
    Andersson, Maria
    et al.
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik.
    Kristofferson, Hanna
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik.
    Structural Optimization of Product Families: With Application to Vehicle Body Structures2006Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    Some products share one or two modules and while developing these products, structural optimization with stiffness as the objective function can be a useful tool. There might be no or very little CAD-data available in the pre-development phase and it is not certain that existing designs can be, or is desirable to use as a reference. The main objective of this thesis is to establish an accurate and fast-to-use methodology which can be utilized while developing new cars.

    In this thesis, the Volvo products S40, V50 and C70 serve as a basis for this case study. All the models are beam structures and the masses of components are added as point and line masses. Several optimization analyses are performed on one or three products exposed to seven load cases. Additional analyses with shell elements, more simplified models and changed load case balance achieved by normalization of the different load case compliances are also studied to investigate how these factors influence the results.

    Analyses show that front crash to a great extent dominates the results while normalization increases the influence of the remaining load cases. Since front crash is dominating and the front area is shared in all products, the performance is remarkably similar when three products are optimized compared to separate analyses of one product. Analysis of models without added point or line masses gives a result which greatly differs from previous results and therefore shows that added masses are required. The methodology is applicable to develop products and detect new load paths through the car.

  • 23.
    Andersson, Mattias
    Karlstads universitet, Institutionen för ingenjörsvetenskap, fysik och matematik.
    Kylskåpsinredning: Praktiska funktioner2008Independent thesis Basic level (professional degree), 15 poäng / 22,5 hpOppgave
  • 24.
    Andersson, Molly
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Industriell organisation och produktion.
    Andersén, Lovisa
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Industriell organisation och produktion.
    SVÅRIGHETER VID CERTIFIERING AV KVALITETSLEDNINGSSYSTEMET ISO 9001:2015 FÖR SMÅ FÖRETAG2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Studien syftar till att upptäcka svårigheter vid implementering av kvalitetsledningssystemet ISO 9001:2015 på små företag. För att uppnå studiens syfte samlades teorier om kvalitetsledningssystemet ISO 9001 och dess implementerings- och certifieringsprocess in. En fallstudie genomfördes på två analysenheter för att sedan jämföras mot det teoretiska ramverket och erhålla ett resultat. De mest bidragande faktorerna till icke-certifiering av ISO 9001 hos små företag visade sig vara tidsbrist, resursbrist samt kompetensbrist.

  • 25.
    Andersson, Ola
    Högskolan Kristianstad, Sektionen för hälsa och samhälle.
    Gage R&R studie på mätutrustning för förpackningsavstånd2014Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    The aim of the thesis is to analyse and understand resolution, repeatability and reproducibility of the measurement system for package distance. The measurement system for package distance is already in use, no Gage R&R has been performed on the system and before spreading use of the system the quality of the system has to be understood and approved

  • 26.
    Andersson, Viktor
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Olsén, Martin
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Kilhus i plast: Omläggning av stålprodukt till produkt i plast2010Independent thesis Basic level (degree of Bachelor), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Abstract

    Our bachelor degree thesis was carried out in collaboration with Ivar Petterssons Järnmanufaktur AB in Smålandsstenar. We were asked to replace their wedge housing, used to fasten the wires to the power lines, with a similar structure in a plastic material. The idea for this project started with Ivar Petterssons Järnmanufaktur AB having problems with the casting quality that forced them to perform expensive tests on each of the wedge houses to ensure the quality. They are currently produced in China which is also a major drawback because it requires expensive long delivery times.

    The method we used is Fredy Olsson's Princip- and Primärkonstuktion (1995). We have consistently been in the project on so-called "broad front", which means that you create several sketches, ideas and changes in parallel, and then evaluates all. With this method we were able to largely concentrate on the current part of the project, rather than using the more time-consuming "trail and error" method, which is basically doing one idea at a time, and evaluate them one by one.

    At first we were very optimistic and thought we would be able to order form for the injection moulding process, but as the project progressed we found we were not certain that the product would hold and we were forced to present the solution as a concept that will require testing before it’s finished, and not a finished solution.The results we presented for Ivar Pettersssons Järnmanufaktur is a complete drawing on our primary solution, including the release angles. This is because when they decide to go forth with the project, it will be possible to produce a tool without having to make changes to the drawings. Temporary financial calculation shows that the savings may be realized around 1 300 000 SEK by switching to a plastic construction. However we have not been able to verify hours and therefore no cost estimates for the testing done in Sweden, so the actual amount of money saved is larger.

  • 27.
    Anundi, Elina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Kundlojalitet i mindre B2B företag2015Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Är nöjda kunder automatisk lojala kunder? Det krävs mer än bara en positiv upplevelse av servicekvalitet för att nå hög lojalitet bland sina kunder. Trots att kunderna upplever servicen lika, kan deras bedömning av tillfredsställelse variera p.g.a. olika förväntningar och prioriteringar. Upplevd servicekvalitet och tillfredsställelse är de första faktorer som påverkar lojalitet. Men det krävs också förtroende för såväl företaget som också på individnivån till företagets representanter, innan kunderna vågar binda sig till en relation med en leverantör. Allt detta påverkar relationen, som med tiden kan utvecklas och fördjupas. Det är alltså servicekvalitet, tillfredsställelse, förtroende samt beredskap att binda sig till en relation och relationskvalitet som påverkar lojalitet i olika utsträckning inom olika branscher.

    Den empiriska undersökningen som genomfördes i form av en webbenkät bland kunder hos ett mindre Business-to-Business (B2B) företag visar att segmentering baserad på lojalitet är ett effektivt sätt att skapa förståelse för hur lojala och icke-lojala kunder ser på företaget och deras servicekvalitet. Segmentering baserar på några extra frågor som mäter lojalitet. Trots låg antal svar (17 svar) är resultat enhetlig för varje segment och visar därmed vilka brister som bör åtgärdas.  

  • 28.
    Arvidsson, Totte
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Det kommunala ledarskapet i det förebyggande krisberedskapsarbetet- En kris eller en möjlighet?: Kvalitativ studie- med utgångspunkt i offensiv kvalitetsutveckling2015Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med föreliggande studie var att med utgångspunkt i offensiv kvalitetsutveckling bidra med kunskap om det kommunala ledarskapet i det förebyggande krisberedskapsarbetet. Den metod som har använts har varit hermeneutisk, induktiv samt kvalitativ metod. En multipel fallstudie har gjorts genom tre intervjuer med säkerhetsstrateger/beredskapssamordnare i kommunal sektor. Frågorna har varit semistrukturerade, där frågorna skapades med inflytande av Appreciative Inquiry. De slutsatser som framkom var att det kommunala ledarskapet har styrkor och utvecklingsmöjligheter i det förebyggande krisberedskapsarbetet. Det fanns styrkor och utvecklingsmöjligheter i samtliga av hörnstenmodellens värderingar. Dessa styrkor och utvecklingsmöjligheter i det kommunala ledarskapet kan bidra till en positiv utveckling av krisberedskapsarbetet och skapa ett tryggare samt säkrare samhälle. Exempel på upplevda styrkor var kommunala ledare som tillåtit delaktighet i risk- och sårbarhetsanalyser och bidragit till utbildningar. Exempel på utvecklingsområden för kommunala ledare var att ledare bör bidra till mer öppenhet, lyhördhet, delaktighet och diskussioner gällande krisberedskapsarbetet.

  • 29.
    Asif, Muhammad
    et al.
    University of Twente.
    Searcy, Cory
    University of the Punjab, Lahore.
    Garvare, Rickard
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Ahmad, Niaz
    National Textile University, Faisalabad.
    Including sustainability in business excellence models2011Inngår i: Total quality management and business excellence (Online), ISSN 1478-3363, E-ISSN 1478-3371, Vol. 22, nr 7, 773-786 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this paper is to explore the adequacy of business excellence models (BEMs) to address corporate sustainability, which is conceptualised in terms of economic, social, and environmental bottom lines. How organisations may manage corporate sustainability in the absence of a comprehensive sustainability management system standard is also explored. A survey of literature has been carried out. The European Foundation for Quality Management (EFQM) excellence model and the Baldrige Criteria for Performance Excellence (BCPE) are analysed with regard to their considerations of sustainability. The findings reveal that while triple bottom-line considerations are addressed to some extent in the studied BEMs, the models per se do not comprehensively address sustainability issues and economic prosperity remains a dominant consideration. Suggestions for the improvement of the EFQM excellence model and BCPE are discussed. To provide a comprehensive approach for addressing corporate sustainability, an integrated quality-sustainability framework is proposed. The essence of the framework is that sustainability indicators, such as those provided in the Global Reporting Initiative framework, could be integrated with core business processes using the structures and infrastructure provided by BEMs. The proposed improvements should be considered in future revisions of the EFQM excellence model and BCPE.

  • 30.
    Assarsson, Felix
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    Håkansson, Fredrik
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    Guide till ATEX: Framställning av ett virtuellt verktyg för arbete med ATEX hos Plåt och spiralteknik AB2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I detta arbete har vi fördjupat oss i ATEX-direktiven för att undersöka hur Plåt och spiralteknik ABs arbete på området kan förbättras. I dagsläget säljer företaget ATEX-godkänd utrustning periodvis men anser att deras kunskaper om ATEX inte är tillräckliga för att tillgodose alla kunders behov. Målet med detta arbete var att ta fram en manual för de regler kring explosionsförebyggande föreskrifter som gäller företagets produkter. Detta arbete har resulterat i en manual i form av en lathund för arbete med ATEX anpassad för PSTs verksamhet.

  • 31.
    Attervall, Sebastian
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Gustafsson, Nichlas
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Styrning och nödbroms av ModuLith2008Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    The purpose of this project is to get a fully functional, automatic steering system and a variable breaking system with an emergency breaking function to an off road vehicle. This off road vehicle is supposed to work as an aid in military situations. A team of two, Sebastian Attervall and Nichlas Gustafsson, got an order from Jonas Nyårds and the PreeRunners Project to construct a steering system that could manoeuvre an off road vehicle without any human involvement. To make this possible the vehicle would be guided by onboard sensors, cameras and computers. The team where also assigned to construct an automatic breaking system, there also no human would be involved. The breaking system should as well contain an emergency stop function to prevent any accidents. The team has solved the problems assigned by using theories by David G. Ullman. The system that was eventually chosen was a steering system containing a 48V, 250W DC motor. A planetary gear where chosen to increase the torque from the engine. To translate the torque from the planetary gear to the steering bar a chain with chainwheel where chosen, this because the chain and chainwheel could withstand the immense forces acting on the chain. Between the planetary gear and the chainwheel a skid clutch is placed to prevent destruction on the planetary gear due to overload. The whole steering system is monitored by two rotary encoders, one placed on the engine and one placed on the steering bar. The breaking system eventually chosen where a system build on the existing drum brakes, placed in the front. To make the system independent from any human interference a system containing a linear motor, an electromagnet and a spring where chosen. The system works by letting the spring act on the wire from the existing drum breaks. The spring is always compressed so a force will always act on the wire when the system is at rest. By compressing the spring further the force acting on the wire will decrease and by compressing it enough the breaks will be released. The force compressing the spring will come from the linear motor. And to make the system failsafe in case of an emergency an electromagnet will be placed between the linear motor and the spring. When the power is cut to the electromagnet the compressed spring will be released and the drum breaks will break. The breaking system as well will be supervised by encoders and in this case linear encoders.

  • 32.
    Au-Yeung, Ginsun
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper. Uppsala universitet.
    Andersson, Mattias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper. Uppsala universitet.
    How can Lean contribute to create effective meetings?: A case study at Ericsson in Borås2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Lean is a philosophy that has been studied extensively in recent years, and it has been successfully implemented in a number of different processes and businesses. This study aims to examine how Lean can contribute to create effective meetings, which is a topic that has received limited attention in today’s research.

    Firstly, a situation analysis is done in order to identify common meeting problems at Ericsson Borås. Secondly, a comprehensive analysis is conducted concerning whether Lean is applicable on meeting processes or not. This analysis is mainly based on the five principles of Lean Thinking. Thirdly, the study investigates the potential effect of an implementation of Lean, as well as how Lean principles can be applied in order to reduce or eliminate wastes.

    The result of the analysis formed the base for the development of the action plan. Subsequently, the action plan is implemented on the meeting processes by pilot testing it on three different meetings. This analysis is mainly focusing on whether the meeting problems have been eliminated or not.

    Based on our research, we have perceived that almost every meeting is unique and all meeting problems we have identified do not occur at all meetings. Majority of the meeting problems were eliminated by applying Lean principles. Moreover, several respondents also expressed that Lean is a good way to give more structure to meetings, and therefore contributes to more effective meetings. However, we have noticed that principles of Lean cannot eliminate all meeting problems at Ericsson. This can be seen as minor criticism when organizations use Lean as the only solution to improve meeting processes.

  • 33.
    Axelsson, Daniel
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Design and Development of a Spray Booth2008Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    As a part of a more extensive project of developing a new finishing line at the Bolivian door manufacturer Tecno Carpinteria San Pedro this thesis presents the development process for a special designed spray booth. The thesis covers every phase from a product idea to a final concept design.

    Working with finishing of furniture and other wooden products can effect the workers health in a negative way and damage the environment. The final result of the manufactured door is also depending on the how well the ventilation system in the working area is. Because of these reasons it is important to use safety equipment and a good ventilation system in the working area. As a part of this new finishing line San Pedro is in need of a special designed spray booth to control the spread of paint particles and other hazard substances that is a result of the finishing process.

    Together with the consultant firm CADEFOR a spray booth is designed and a proposal design is presented in this thesis. The result is a design built up with a dry filter solution together with an extractor that creates a cross draft airflow towards the rear part of the spray booth. The result of the project together with some recommendations of increasing the capacity in the finishing line are also presented.

  • 34.
    Backlund, Fredrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    A project perspective on doctoral studies: a student point of view2017Inngår i: International Journal of Educational Management, ISSN 0951-354X, E-ISSN 1758-6518, Vol. 31, nr 7, 908-921 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose

    Many doctoral students never obtain a doctoral degree, and many do not finish their studies in time. To promote aspects of effectiveness and efficiency in doctoral studies this article aims to explore a project perspective, more specifically how doctoral students experience their studies in terms of key dimensions of projects.

    Design/methodology/approach

    Written reflections concerning a project perspective in doctoral studies, based on 18 students at a Swedish university, have been categorised and analysed by means of the qualitative research software NVivo.

    Findings

    Main findings are: Reflections on the project manager role including both the supervisor and the doctoral student, and different views on project control parameters and the concepts goal-seeking and goal-orientation. A more comprehensive picture of project planning is presented, compared with the Individual Study Plan (ISP), including different project methods and tools that can be suitable in a doctoral project.

    Research limitations/implications

    The study is based on a limited number of doctoral students, however the aim has been to give examples of project perspectives. The findings could be valuable for increased understanding of doctoral studies and of the project management field in general.

    Practical implications

    The study can induce awareness among doctoral students and supervisors of a project perspective in doctoral studies, promoting aspects of efficiency and effectiveness.

    Originality/value

    Compared to previous research, this study explicitly tries to understand how doctoral students make sense of their doctoral studies from a project perspective.

  • 35.
    Backlund, Fredrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Conclusions of planning and preparation for RCM implementation: a case study at a Swedish hydro power plant2002Inngår i: Proceedings: ICOMS-2002, International Conference of Maintenance Societies : Queensland Hilton Hotel, 21 - 24 May 2002, Brisbane, Queensland, Central Queensland University, 23 - 24 May 2002, Gladstone, Queensland, Brisbane, 2002Konferansepaper (Fagfellevurdert)
  • 36.
    Backlund, Fredrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Managing the introduction of RCM experiences from a Swedish hydropower company2005Inngår i: 2005 IEEE Power Engineering Society general meeting: San Francisco, CA, June 12 - 16, 2005, Piscataway, NJ: IEEE Communications Society, 2005, 2646-2648 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The introduction of reliability centred maintenance, RCM, has become more and more commonly within different industrial sectors. The many application areas, and the long-time use of RCM, points to the importance and usefulness of RCM when developing an effective and efficient maintenance programme. However, introducing RCM, implies introducing a new way of way of working with maintenance in an organisation, which can be very complex and cumbersome. Although RCM is an organised common sense approach to improvements of maintenance performance, a long-term approach may be difficult to manage. Several examples of failed introductions of RCM exist in various lines of business and types of organisations. Some of the main reasons why the RCM introduction becomes problematic or fails are technical in nature, but the majority of problems seem to be managerial and organisational. The introduction characteristics described above has been studied within a longitudinal single-case study, performed within a hydropower organisation. The case study, as well a multiple-case study, including three other hydropower organisations. Based on the findings in the case studies, a comprehensive and holistic RCM introduction strategy was proposed. The strategy framework could be seen as a structured approach to managing obstacles and driving forces identified in the case studies.

  • 37.
    Backlund, Fredrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Managing the introduction of reliability-centred maintenance, RCM: RCM as a method of working within hydropower organisations2003Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Due to a competitive environment, many companies are required to reduce their overall costs while maintaining the value and reliability of their assets. The use of Reliability-Centred Maintenance, RCM, can support organisations to develop an effective and efficient maintenance programme, meeting these requirements in a cost-effective manner. RCM basically combines different techniques and tools, in a systematic approach to managing risks, as a basis for maintenance decisions. When introducing RCM with the aim of changing the overall way of working with maintenance in the organisation, i.e. on a full-scale basis, a long- term introduction approach should preferably be used. In addition to improve the performance of the assets, this approach uses RCM to improve knowledge, motivation and teamwork among the personnel. In that way, the approach could promote commitment of managers and employees, making an RCM based maintenance programme far more likely to endure. However, in several cases, organisations have experienced severe difficulties when introducing RCM on full-scale basis. Some of the reasons are technical in nature, but the majority are managerial obstacles. In the research project presented in this thesis, an aim has been to obtain a better understanding of why some organisations experience a cumbersome introduction of RCM. A focus has been to identify managerial factors that affect an RCM introduction in form of obstacles and driving forces. In the research project, a longitudinal single-case study has been performed during 1997 - 2003, studying the efforts towards an RCM introduction in a Swedish hydropower company. Many of the findings in the single-case study have been validated by a multiple-case study, including three other hydropower organisations introducing RCM. The findings are basically different kinds of managerial factors. These factors could be managed within four management perspectives, which points out the need of a holistic approach when managing RCM introduction. An RCM introduction process has also been identified during the research, where the managerial factors can be structured according to different phases. Based on these findings, an RCM introduction strategy framework has been developed, with the aim to facilitate for organisations going to introduce RCM. The strategy framework is structured according to the different phases in the RCM introduction process, with requirements and recommendations to be considered in each phase.

  • 38.
    Backlund, Fredrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Reliability-centred maintenance: identification of management and organisational aspects when introducing RCM1999Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Increased demands on productivity, quality and cost-efficiency affecting manufacturing trends towards increased complexity and higher degree of process automation. A major break down in such a manufacturing system may generate severe damage on productivity, environment and personnel. Using risk assessment to identify serve risks within a plant, in combination with different maintenance strategies, is one course of action to prioritising maintenance activities needed. A methodology for executing a so-called risk-based maintenance is reliability-centred maintenance, RCM. There are several benefits generated from RCM, for example, improved safety and maintenance cost-effectiveness. Though, several companies have problems to make it work. The problems that occur are many times within management and organisational (M&O) aspects, such as lack of communication and management support. Some M&O aspects of importance when introducing improvement methods as TQM and TPM are similar with the ones valid for RCM. Though, differences seem to depend on the use of RCM in a more technology environment, overshadow the affects M&O aspects really bring about when introducing it. That is probably the main reason why obstacles occur when introducing RCM. A structured step model has been developed, focusing on the preparation and planning activities when introducing RCM.

  • 39.
    Backlund, Fredrik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Will a preparation stage facilitate the implementation of RCM?1999Inngår i: Safety and Reliability: proceedings of ESREL '99 - The tenth European Conference on Safety and Reliability, [held in] Munich-Garching, Germany, 13-17 September 1999 / [ed] Gerhart I. Schueller; P. Kafka, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1999, 173-178 s.Konferansepaper (Fagfellevurdert)
  • 40.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Akersten, Per-Anders
    RCM introduction: process and requirements management aspects2003Inngår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 9, nr 3, 250-264 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Organisations have introduced reliability-centred maintenance (RCM) with a view to changing their overall way of performing maintenance. Many times, however, these organisations have experienced cumbersome or even failed RCM introduction. This is usually because of managerial and organisational obstacles, which more or less unexpectedly turn up during introduction. This paper focuses on managing the introduction of RCM. By applying process and requirement management principles, obstacles that turn up during introduction can be identified early on. As an example of this, we cite the results of a case study of the introduction of RCM in a Swedish hydropower company.

  • 41.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Chronéer, Diana
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Sundqvist, Erik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Maturity assessment: towards continuous improvements for project-based organisations?:2015Inngår i: International Journal of Managing Projects in Business/Emerald, ISSN 1753-8378, E-ISSN 1753-8386, Vol. 8, nr 2, 256-278 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PurposeThe aim of this study is to contribute to the empirical research on project management maturity assessments, specifically based on a maturity model. Design/methodology/approachThe empirical data is based on a case study including in-depth interviews with a semi-structured approach, followed by a focus group interview. A survey was distributed within a project-based organisation and to client and stakeholder representatives, and then analysed. The organisation in the case study is a project department within a Swedish mining company. FindingsCareful considerations are needed when choosing a project management maturity model (PM3) as the model structure can influence the assessment’s focus. It is also important to include both internal and external project stakeholders in the assessment to achieve an efficiency and effectiveness perspective when analysing PM capabilities. Valid information from an assessment is crucial, therefore, clear communication from management is important in order to motivate the participants in the assessment. Research limitations/implicationsImproved understanding for implementing and applying a PM3 contributes to the increased knowledge of drivers, enablers and obstacles when assessing PM maturity, which also creates a basis for further research initiatives. Practical implicationsAn increased knowledge of drivers, enablers and obstacles should be valuable for practitioners introducing and applying a PM3.Originality/valueThis case study gives an in-depth insight into the implementation of a PM3 within a project-based organisation. Through conducting a literature review, it was found that this type of empirical research is rare

  • 42.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Chronéer, Diana
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Innovation och Design.
    Sundqvist, Erik
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Project Management Maturity Models – A Critical Review: A Case Study within Swedish Engineering and Construction Organizations2014Inngår i: Procedia - Social and Behavioral Sciences, ISSN 1877-0428, E-ISSN 1877-0428, Vol. 119, 837-846 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Different kinds of project management maturity models (PM3s) exist today, most of them inspired by the capability maturity model (CMM) developed in the beginning of the 90ies, originally intended to measure capability in software development projects. Research indicates that organizations with higher project management (PM) maturity levels are expected to be successful in terms of project effectiveness and efficiency, and thus have a competitive advantage in the marketplace. Though, despite several PM3s developed during a time period of over 20 years, knowledge about how PM3s are a*pplied in organizations is sparse within the PM literature. This paper explores how major engineering and construction companies view PM maturity and PM3s in order to develop and improve their PM practices. These kinds of organizations are mainly project-intensive, objective oriented,and have the capabilities to perform overall business development initiatives, i.e. suitable for applying PM3s.The contribution of PM3s to organizational improvement and development is somewhat unclear. Therefore, a literature review highlights different aspects regarding PM3s, specifically their purpose, strengths, and weaknesses. To what extent PM3s are used, interviews have been conducted with seven respondents within different project intensive organizations, in their roles as project managers or in charge of PM development. How a PM3 can beintroduced and applied is explored via an in-depth case study at the major mining company in Sweden, LKAB. However, tentative results show that the application of PM3s in Swedish engineering and construction organizations are limited, indicating that further research is needed

  • 43.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Hannu, J.
    Luleå tekniska universitet.
    Can we make maintenance decisions on risk analysis results?2002Inngår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 8, nr 1, 77-91 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For several branches of industry, an increasingly competitive environment has raised important questions concerning maintenance in plant systems. For example, the 1996 deregulation in Sweden's electricity sector has resulted in increased competition among the country's power producers. To survive the competition, suppliers have to reduce maintenance costs, i.e. handle maintenance more efficiently. Risk analysis is one tool decision makers can use to help them prioritise as they plan maintenance actions. There are a number of different approaches to risk analysis. As the results of an analysis must form a reliable basis for decision making, it is important to consider whether the quality of the results will vary significantly with the risk analysis approach chosen. This paper presents a comparative study based on three independent risk analyses performed on a specific hydro-power plant. The comparison and evaluation of the analyses reveal major differences in performance and results, along with various factors that affect the quality of the analyses. The study establishes the importance of a well-planned requirement specification and the need to analyse and interpret risk analysis results, before making maintenance decisions.

  • 44.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Holmberg, Rikard
    Vattenfall Vattenkraft.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    A 10 years journey introducing RCM within hydropower: a case study at Vattenfall Vattenkraft2008Inngår i: EuroMaintenance Papers: Conference and Trade Show on Asset Management & Production Reliability ; Brussels Expo, 8 - 10 April 2008, Belgian Maintenance Association , 2008, 21:1-21:10 s.Konferansepaper (Fagfellevurdert)
  • 45.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Jonforsen, F.
    Planning for RCM implementation in an outsourcing environment: a case study at a Swedish hydro power plant2002Inngår i: Proceedings of the 16th European Maintenance Congress: Euromaintenance 2002, 2002, 19-28 s.Konferansepaper (Fagfellevurdert)
  • 46.
    Backlund, Fredrik
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Larsson, Dan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Rhen, Mats
    Luleå tekniska universitet.
    Risk analysis and condition monitoring for efficient maintenance planning at Swedish hydro power plants1998Inngår i: Safety and reliability: proceedings of the European Conference on Safety and Reliability, ESREL '98, Trondheim, Norway, 16 - 19 June 1998 / [ed] Stian Lydersen, Amsterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1998, 247-253 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Maintenance issues have in recent years grown in importance. Higher demands on availability and quality of products are some of the reasons. These demands have resulted in an increased use of condition monitoring systems, to support an effective maintenance concept. For a complex system, this technique generates an enormous amount of signals which is difficult to diagnose, and a great amount of information which is difficult to handle and interpret for the operator. Therefore, improved diagnosis and decision support tools are necessary, as a complement to the monitoring systems. This paper presents an ongoing project, trying to find a new approach to condition monitor and diagnose Kaplan hydro-power turbines, where the chain from transducer to decision making is under consideration. Risk analysis is adequate for decision making among alternative maintenance tasks and the ambition is a risk model that can be systematically updated with varying economic data and production requirements. Also, the availability is under consideration for the hydro power plant, as a total system, where the owners of the plant should be able to steer the availability according to demand. Another important aspect is the possibility of the condition monitoring system to test itself, which will prevent false alarms.

  • 47.
    Bagampadde, Umaru
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap.
    Investigations on moisture damage-related behaviour of bituminous materials2005Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This doctoral thesis presents results of literature review on classical and contemporary aspects of stripping, as well as experimental investigations on moisture damage as influenced by bituminous materials.

    Previous research in the area of moisture damage was reviewed and synthesized into a state-of-the-art. Important parameters linked to moisture sensitivity, like bituminous material characteristics, dynamic loads from heavy vehicles, environmental factors, construction practice and nature of anti-stripping additives, are presented. The state-of-the-art in current test methods is summarized and given.

    The experimental work involved investigations of the influence of bitumen and aggregate composition on water susceptibility. The influence of aggregate mineralogy and chemistry was evaluated using eleven aggregates and one bitumen, followed by studying the interactive effect of four bitumens and four aggregates. Moisture sensitivity was evaluated in accordance with (EN 12697-12:2003) for conditioning, ASTM D 4123 for resilient modulus determination, and (EN 12697-23:2003) for indirect tensile strength testing. Furthermore, thermal stability of two liquid amine anti-stripping additives mixed with two bitumens of varied acidity was investigated using potentiometric titration and Fourier Transform Infrared (FTIR) Spectroscopy. Lastly, a technique based on Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR) was developed and used for studying transport of water across thin bitumen films, as well as stripping at bitumen/substrate interfaces. Bitumens from different sources and three substrates (silicon, germanium and zinc selenide crystals) were used. Based on the results obtained, it was concluded that aggregates containing sodium and potassium in alkali feldspars generally showed high moisture sensitivity. In contrast, presence of calcium, magnesium and iron was associated with aggregates with low moisture sensitivity. Contrary to several previous findings, one aggregate with practically 100% quartz exhibited low moisture sensitivity. No linear relationship between moisture sensitivity and the contents of SiO2 and Al2O3 in the aggregates studied was established. Results of the interactive influence of bitumen and aggregate composition showed that high acid and low penetration bitumens exhibited high dry strength for all the aggregates studied. On the other hand, for a given bitumen, the wet strengths were found to be aggregate specific.

    The results of tests on thermal stability of amine additives showed that usefulness of these additives reduces considerably, when the more alkaline additive was mixed with the high acid bitumen, followed by storing the blends under pronounced conditions of time and temperature (24 hours and 140ºC, or more, in this study). Much less interaction occurred when the less alkaline additive was blended with the low acid bitumen. Even if a correlation was found between the results of potentiometric titration and Fourier Transform Infrared spectroscopy, the latter was not considered good enough at detecting amine additives, especially at low dosages.

    The technique based on FTIR-ATR developed in this study distinguished between good and bad bitumens with regard to stripping. The effectiveness of amine-based additives in reducing stripping was also shown by the method. Three likely processes occurred during the test, namely water diffusion, film break, and displacement (stripping) of bitumen from the substrate surface. The results also indicated that the diffusion process of water into the bitumen/substrate interface does not obey Fick’s law.

  • 48.
    Bagampadde, Umaru
    et al.
    Faculty of Technology, Makerere University, Kampala.
    Isacsson, Ulf
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap.
    Characterization of chemical reactivity of liquid antistripping additives using potentiometric titration and FTIR spectroscopy2006Inngår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 20, nr 5, 2174-2180 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chemical reactivity of two liquid antistripping additives mixed with two bitumens of diverse acid numbers was evaluated. Additives present in the blends were detected by use of potentiometric titration and infrared spectroscopy. Tests were done at dosages of 0, 0.5, 1.0, and 2.0%; storage temperatures of 25, 100, 140, and 150 degrees C; and storage times of 1, 24, and 72 h. At 0.5% dosage, close to typical field values, the more basic additive mixed with bitumen of high acid number almost ceased to be detected after 24 h of storage at 140 degrees C. The less basic additive could be detected beyond these conditions, irrespective of the bitumen used. At higher dosages, reactions with the bitumens were found to be more pronounced with the more basic additive. The reactions between the additives and bitumens studied seemed to be higher in the bitumen with higher acid number, irrespective of the dosage. Statistical analysis indicated that all the parameters studied significantly affected change in amount of additives detected in the blends. A correlation was established between potentiometric titration and infrared spectroscopy in detecting amine additives. This correlation notwithstanding, infrared spectroscopy was found to not be a good tool for measuring amines in the blends, especially at low concentrations.

  • 49.
    Bagampadde, Umaru
    et al.
    KTH, Tidigare Institutioner                               , Byggvetenskap.
    Isacsson, Ulf
    KTH, Tidigare Institutioner                               , Byggvetenskap.
    Kiggundu, Bob
    KTH, Tidigare Institutioner                               , Byggvetenskap.
    Classical and contemporary aspects of stripping in bituminous mixtures2004Inngår i: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, Vol. 5, nr 1, 7-45 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stripping or removal of bitumen from an aggregate because of water penetrating into the interface causes many pavements to fail. Stripping has been existent since the advent of paving technology. It causes functional weakening of pavements leading to costly repairs. This state-of-the-art paper deals with important concepts of stripping as, bitumen chemistry and rheology, aggregate properties (chemical and mineralogical composition, surface texture, morphology, porosity, etc), traffic, water properties, construction practices (mixing, placement and in-service drainage) and nature of antistripping additives. Adhesion of bitumen onto aggregate is explained based on theories like mechanistic tenacity, molecular orientation, chemical reaction, and thermodynamic balance of interfacial forces. Stripping is elucidated using several mechanisms namely, displacement, detachment, spontaneous emulsification, bitumen film rupture, water pore pressure, hydraulic scouring, chemical disbanding, microbial activity, osmosis; and blistering and pitting. Attendant theories to the mechanisms are explained. Moisture sensitivity test methods emerged are described and discussed. The large number of tests that have evolved shows the importance of the phenomenon of stripping. Remedial measures which include use of antistripping additives, careful selection of hot mix component materials, good construction practice, and others have been proposed for use in practice.

  • 50.
    Bagampadde, Umaru
    et al.
    Makerere University, Kampala.
    Isacsson, Ulf
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap.
    Kiggundu, Bob
    Makerere University, Kampala.
    Impact of bitumen and aggregate composition on stripping in bituminous mixtures2006Inngår i: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 39, nr 287, 303-315 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The impact of bitumen and aggregate composition on stripping was investigated using four bitumens and four aggregates. Moisture sensitivity was assessed based on retained resilient modulus and tensile strength ratio (MRR and TSR, respectively). The results indicate that mixtures from the bitumen with a high acid number exhibited high resilient modulus and tensile strength in the dry condition for all the aggregates. In wet condition, this conclusion did also hold except for one aggregate. Regarding penetration grade, mixtures made with lower penetration grade bitumen exhibited higher resilient modulus and tensile strength, in dry and wet conditions, than those of higher penetration grade. Bitumen characteristics like acid number, penetration grade and molecular size distribution did not influence moisture sensitivity. Mixtures with aggregates containing alkali metals (sodium and potassium) exhibited relatively high moisture sensitivity, regardless of the bitumen used. In contrast, indications of moisture sensitivity were not apparent in mixtures made with aggregates containing calcium, magnesium and iron. Data analysis revealed that variability in moisture sensitivity is attributed to aggregate rather than bitumen. No significant interaction effect between bitumen and aggregate was found on moisture sensitivity. The results indicated good correlation between MRR and TSR in ranking mixtures for stripping.

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