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  • 1.
    Akter, Shaheda
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Khani, Mohammad
    Characterisation of laminated glass for structural applications2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Laminated glass (LG) consists of two or more glass layers bonded by an elasto-polymeric layer, the most commonly used being PVB (Polyvinyl Butyral). LG has improved safety properties compared with single layer glass because the interlayer prevents large sharp pieces from spreading when the glass is broken by impact. Even if one of the layers breaks, the other layer(s) still contribute in carrying the load. Through proper understanding of the interaction between the interlayer and the glass LG could be used in engineering as a load bearing material to a larger extent. This study aims at gaining a deeper knowledge of the behaviour of laminated glass by experimental investigations and by numerical model simulation. To pursue the proposed study, three point bending test with simple support conditions were performed for single layer glass and laminated glass units with three different types of interlayer materials. Corresponding finite element numerical models were created in the software ABAQUS to fit the model with experiment to obtain the bending stiffness and shear stiffness of the interlayer material. The PVB tested showed viscos-elastic material properties, whereas other two interlayer materials, Solutia DG 41 and Sentry Glass, showed linear elastic properties. PVB is the least stiff interlayer material among the three types. Solutia DG 41 and Sentry Glass have similar stiffness, about 13 to 15 times stiffer than the PVB. The behaviour of laminated glass lies in general between the two limits of a layered glass unit with no interaction and a monolithic unit of the same total thickness, depending on the stiffness of the interlayer material. Failure tests of the specimens were also carried out. The obtained strength of glass from four specimens is 80 MPa to 92 MPa with a variation of about 15%. The number of more performed experiments would have better outcome for strength of glass. The bending stiffness of the laminated glass as estimated with the numerical model fitted well with the experimental results with an error of about 2%. Hence the experimentally and numerically obtained results show a good correlation and are thought be possible to use in future larger scale modelling.

  • 2.
    Alajbegovic, Faruk
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Imsirovic, Alen
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Uppföljning av energiprestanda samt boendes upplevelser av Portvakten Söder: Energy Monitoring and residents' perceptions of Portvakten Söder2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Portvakten Söder i Växjö, med sina två huskroppar och 64 lägenheter är de högsta passivhusen i Sverige med en trästomme. En energiuppföljning görs för år 2012. Skillnader kring projekterat och uppmätt värde behandlas och klargörs. Granskning av funktionalitet och värmeåtervinningsmängd av avloppsvärmeväxlaren utreds. Ett frågeformulär har skickats ut och sammanställts, där hyresgästerna delar med sig av sina upplevelser utav Portvakten Söder.

  • 3.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Effect of compactness on oxynitride glasses properties2013Conference paper (Refereed)
  • 4.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Formation and properties of nitrogen rich Ca-Si- (Al)-O-N glasses and Ceramics2014In: Conference proceeding 2014 Spring World Congress on Engineering and Technology, Shanghai, China (April 2014)., 2014, p. 59-59Conference paper (Refereed)
  • 5.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Melting Characteristics and Morphology of Bottom Ash and Filter Ash of the Circulating Fluidized Bed Boiler2013In: 21st European Biomass Conference and Exhibition, Copenhagen, Danmark, 3rd-7th June, 2013, ETA-Florence Renewable Energies , 2013, p. 1189-1191Conference paper (Refereed)
    Abstract [en]

    The aim of this work was to investigate the melting characteristics and morphology of filter ash and bottom ash with and without 7% of peat addition to the fuel of the circulating fluidized bed boiler. The samples were characterized by simultaneous thermal analysis (STA) and scanning electron microscope (SEM). The STA results indicate that the filter ash melts at 1140oC with 10 wt% of the mass loss and Bottom ash partially melts at 1170oC with below 2 wt% of the mass loss. The low melting point of the filter ash is due to the high concentration of the alkali metals in the filter ash. Similar trends were observed in the case of fly ash and bottom ash with peat admixture to the fuel. Furthermore the elementary analysis via scanning electron microscopy, coupled with energy-dispersive X-ray analysis showed that 7% of peat addition to the fuel does not significantly effect on the ash composition.

  • 6.
    Aminbaghai, Mehdi
    et al.
    Vienna University of Technology, Austria.
    Dorn, Michael
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology. Vienna University of Technology, Austria.
    Eberhardsteiner, Josef
    Vienna University of Technology, Austria.
    Pichler, Bernhard
    Vienna University of Technology, Austria.
    A Matrix-Vector Operation-Based Numerical Solution Method for Linear m-th Order Ordinary Differential Equations: Application to Engineering Problems2013In: Advances in Applied Mathematics and Mechanics, ISSN 2070-0733, E-ISSN 2075-1354, Vol. 5, no 3, p. 269-308Article in journal (Refereed)
    Abstract [en]

    Many problems in engineering sciences can be described by linear, inhomogeneous, m-th order ordinary differential equations (ODEs) with variable coefficients. For this wide class of problems, we here present a new, simple, flexible, and robust solution method, based on piecewise exact integration of local approximation polynomials as well as on averaging local integrals. The method is designed for modern mathematical software providing efficient environments for numerical matrix-vector operation-based calculus. Based on cubic approximation polynomials, the presented method can be expected to perform (i) similar to the Runge-Kutta method, when applied to stiff initial value problems, and (ii) significantly better than the finite difference method, when applied to boundary value problems. Therefore, we use the presented method for the analysis of engineering problems including the oscillation of a modulated torsional spring pendulum, steady-state heat transfer through a cooling web, and the structural analysis of a slender tower based on second-order beam theory. Related convergence studies provide insight into the satisfying characteristics of the proposed solution scheme.

  • 7.
    Andersson, Victor
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Visekruna, Sanjin
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jasarevic, Haris
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Modellering av befintliga byggnader2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rapporten avhandlar modelleringen av en befintlig industribyggnad och dess tillvägagångssätt. I rapporten har även utredningar och studier granskats kring neutrala filformat, laserscanning och byggprocessen i allmänhet då dessa omnämnda ämnen går hand i hand och utgör fundamenten i modellerings-projekt. Projektet som författarna modellerade var det befintliga renseriet på Södra Cell i Mönsterås. Intervjuer som kontinuerligt utförts med berörda personer framgår under genomförande delen.

  • 8.
    Bader, Thomas K.
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology. Vienna University of Technology, Austria.
    Schweigler, Michael
    Vienna University of Technology, Austria.
    Hochreiner, Georg
    Vienna University of Technology, Austria.
    Eberhardsteiner, Josef
    Vienna University of Technology, Austria.
    Serrano, Erik
    Lund University.
    Dorn, Michael
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Experimental Assessment of the Load Distribution in Multi-Dowel Timber Connections2016In: 17th International Conference on Experimental Mechanics, Rhodes, Greece, July 3-7, 2016, 2016Conference paper (Other academic)
    Abstract [en]

    An integrative, hierarchically organized testing procedure for the quantification of the load distribution in multi-dowel timber connections is presented herein. The use of contactless deformation measurement systems allowed the combination of test data from single dowel and multi-dowel connections, which gave access to the loads acting on each dowel over the full loading history. As a consequence of the anisotropic material behavior of wood, a nonuniform and progressively changing load distribution among the dowels was found.

  • 9.
    Billgren, Annette
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Kvarteret Allön 4: Gammalt och nytt i en spännande kombination2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Kristianstads bakgator bestod fram till en bit in på 1900-talet av låg bebyggelse i ett och två plan. Idag finns endast fem bevarade envåningshus kvar inom stadskärnan. Ett av dessa hus har nu under en längre tid fått stå tomt och förfalla medan ett rivningshot inväntas.

    Diskussionerna om vad man ska göra med kvarteret har pågått i snart 20 år, utan att man lyckats nå någon lösning, situationen är minst sagt låst.

    Detta arbete lägger fram nya idéer och förslag på hur huset och kvarteret som det ligger i skulle kunna utvecklas, förslaget som ser till de olika parternas önskemål och som skulle kunna vara en lösning för både huset, staden och fastighetsägaren.

     

  • 10.
    Blyberg, Louise
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Lang, Maria
    Glafo, SE-35196 Växjö, Sweden.
    Lundstedt, Karin
    Glafo, SE-35196 Växjö, Sweden.
    Schander, Matilda
    Glafo, SE-35196 Växjö, Sweden.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Silfverhielm, Magnus
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Stålhandske, Christina
    Glafo, SE-35196 Växjö, Sweden.
    Glass, timber and adhesive joints - Innovative load bearing building components2014In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 55, p. 470-478Article in journal (Refereed)
    Abstract [en]

    Structural glass-timber composite beams and shear wall elements were investigated in terms of their mechanical behaviour, energy performance and their LCA performance. The load bearing components were manufactured using annealed float glass which was adhesively bonded to the timber with different adhesives. The results show, among other things, that is is possible to join the two materials glass and timber and obtaining a non-brittle failure of the beams. The shear wall elements have the potential of being used as stabilising elements and load bearing walls in buildings of up to 4 storeys height. It is possible to combine glass and timber in a load bearing shear wall without loss of energy performance of a building or without loosing LCA performance. In addition to these benefits, the timber glass composite wall has, of course the benefit of being transparent.

  • 11.
    Bolmsvik, Åsa
    Linnaeus University, Faculty of Engineering and Technology, Department of Building and Energy Technology.
    Structural-acoustic vibrations in wooden assemblies:: Experimental modal analysis and finite element modelling2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis concerns flanking transmission in light weight, wooden multi-storey buildings within the low frequency, primarily 20-120 Hz. The overall aim is to investigate how the finite element method can contribute in the design phase to evaluate different junctions regarding flanking transmission.

    Two field measurements of accelerations in light weight wooden buildings have been evaluated. In these, two sources; a stepping machine, and an electrodynamic shaker, were used. The shaker was shown to give more detailed information. However, since a light weight structure in field exhibit energy losses to surrounding building parts, reliable damping estimates were difficult to obtain.

    In addition, two laboratory measurements were made. These were evaluated using experimental modal analysis, giving the eigenmodes and the damping of the structures. The damping for these particular structures varies significantly with frequency, especially when an elastomer is used in the floor-wall junction. The overall damping is also higher when elastomers are used in the floor-wall junction in comparison to a screwed junction. By analysing the eigenmodes, using the modal assurance criterion, of the same structure with two types of junctions it was concluded that the modes become significantly different. Thereby the overall behavior differs.

    Several finite element models representing both the field and laboratory test setups have been made. The junctions between the building blocks in the models have been modeled using tie or springs and dashpots. Visual observation and the modal assurance criterion show that there is more rotational stiffness in the test structures than in the models.

    The findings in this doctoral thesis add understanding to how modern joints in wooden constructions can be represented by FE modelling. They will contribute in developing FE models that can be used to see the acoustic effects prior to building an entire house. However, further research is still needed.

  • 12.
    Bolmsvik, Åsa
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Brandt, Anders
    University of Southern Denmark, Denmark.
    Damping Assessment of Light Wooden Assembly With and Without Damping Material2013In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 49, p. 434-447Article in journal (Refereed)
    Abstract [en]

    Damping elastomers are often used in lightweight wooden constructions and are believed to have good sound insulating effects. In the present study the influence on the structural behaviour by using elastomer damping material (Sylomer®) in the joints, with particular respect to footsteps and floor vibrations, has been investigated. A full scale wooden mock-up was assembled with two different joint configurations and studied under free-free boundary conditions. In the first configuration, the joints between the floor and underlying walls were screwed together. In the second configuration the floor was resting free on top of ribs of elastomer damping material, equivalent to normal building practice when this material is used. Both configurations were analysed and evaluated using experimental modal analysis, in the frequency interval 10-115 Hz.

     

    The relative (viscous) damping ratios of the modes were found to be on average 1.2% for the screwed configuration and 2.1% for the configuration with elastomer damping material in the joints. The damping was found to vary significantly between modes in the elastomer case. It was found that at low frequencies damping was high for modes with large motion on the edge where the elastomer material was. At higher frequencies (above approx. 40 Hz), however, the damping for this configuration decreased. This is believed to be caused by a vibration isolation effect of the elastomer, decoupling the floor from the walls at higher frequencies.

     

    To assess the differences in vibration levels between the two configurations, mean acceleration levels of well spread points on the different building parts where computed and evaluated. It was found that above approximately 70 Hz, the mean vibration level in the elastomer configuration was significantly lower than for the screwed configuration. Below 70 Hz, however, for many frequencies the mean vibration level for the elastomer configuration was significantly higher than for the screwed configuration (as should be expected in vibration isolation). Problems with springiness and footsteps are due to loads in the frequency range of 10 to 50 Hz, this could indicate that elastomers, used as in the present study, could worsen these types of problems, although improving higher frequency acoustic performance.

  • 13.
    Bolmsvik, Åsa
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Linderholt, Andreas
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Stiffness and damping evaluation of Elastomers in different setups2015In: Proceedings of the Internoise 2015 conference, Society of Experimental Mechanics (SEM) , 2015Conference paper (Refereed)
    Abstract [en]

    In timber buildings, elastomers are commonly used to decrease the sound transmission between apartments. Detailed properties of the elastomers are needed in order to model them in a correct yet computational efficient manner. In earlier studies, dynamic experiments have been made on elastomer strips half embedded. However, the sidewise effects need to be further evaluated. In this study, the elastomers are evaluated quasi-statically in different directions, having continuous as well as intermittent distributions, being plane supported or half embedded. An FE-model has been developed using data stemming from the quasi-static tests together with damping estimates stemming from vibrational tests.

  • 14.
    Bonakdar, Farshid
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Implications of energy efficiency renovation measures for a Swedish residential building on cost, primary energy use and carbon dioxide emission2013In: ECEEE Summer Study proceedings: rethink, renew, restart, European Council for an Energy Efficient Economy (ECEEE), 2013, p. 1287-1296Conference paper (Refereed)
    Abstract [en]

    Building sector accounts for 40% of total primary energy use in the EU. Measures to improve energy efficiency in existing buildings may reduce primary energy use and carbon dioxide (CO2) emission. In this study, we analysed the potential final energy savings for space heating and cost-effectiveness of different energy efficiency measures for a Swedish multi-story residential building from building owner perspective. The implications of the measures on primary energy use and CO2 emission were also explored. Building envelope elements were considered as energy efficiency measures. Required investment for energy efficiency measures per saved energy price was used as indication for the cost-effectiveness of energy renovation. We analysed three scenarios of energy renovation where the building is in its initial state, once with and then without renovation need for repair and maintenance purpose and the scenario for the current state of building. The current state of the building has some modification compared to the initial state. We performed sensitivity analysis to study the influence of economic parameters on the cost-effectiveness of energy efficiency measures. The results showed that the energy savings and cost-effectiveness of the measures depend on building characteristics, energy efficiency measures and the assumed economic parameters. Modelling of final energy use, before and after energy renovation, and its cost analysis showed that the considered energy efficiency measures were not economically profitable with the initial economic assumption (6% discount rate and 1.9% annual energy price increase during 50-year lifespan). For the renovation package of all energy efficiency measures, energy renovation appeared to be profitable when discount rate and annual energy price increase were 3% and 2.5% (or larger), respectively. Primary energy use and CO2 emission were reduced by 45 to 50% for the same package for the building with cogeneration-based district heating.

  • 15.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Reforming of tars and hydrocarbons from gasified biomass2013In: Relesing Green Bioenergy for Human: Main Conference Volum 2, Dalia, PR China: BIT Congress , 2013Conference paper (Refereed)
    Abstract [en]

    Tars are produced during gasification of biomass due to thermal decomposition of main constituent of the biomass, cellulose, hemicellulose and lignin. Since the tars will condense on colder surfaces, they cause problems by clogging of pipes and valves and depositions on heat transfer surfaces, for instance. One strategy is to remove the tars by condensing them in water or oil scrubbers, however since the tars might contain a significant part of the heating value in the producer gas the yield of the produced synthesis gas will decrease. To utilize the heat content in the tars they can be converted in situ to synthesis gas either by a catalytic process like steam reforming or autothermal reforming (ATR). The problem with catalytic reforming is that the catalysts used are sensitive towards the sulphur content, mainly H2S, in the producer gas. The deactivation of the reforming catalysts can be counteracted by increasing the reforming temperature, for instance  by the use of ATR. However, at elevated temperature, 1000-1100 oC, the thermal sintering of the catalyst will be accelerated instead. There is a need for development of new high temperature stable reforming catalysts. Another problem is the production of soot due to the high temperatures in the flame in the autothermal reformer unit. The formed sooth will cause problems by clogging packed bed of reforming catalyst and to cope with this it is probably necessary to use a monolithic catalyst.   However, by developing a way to homogenous combust the added oxygen, avoiding the peak temperatures in the flame, would suppress or eventually eliminate the soot formation.      

  • 16.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Usage of Biofuels in Sweden2013In: CSR-2 Catalyst for renewable sources: Fuel, Energy, Chemicals Book of Abstracts / [ed] Vadim Yakovlev, Boreskov Institute of Catalysis, Novosibrisk, Russia: Boreskov Institute of Catalysis , 2013, p. 5-7Conference paper (Refereed)
    Abstract [en]

    In Sweden, biofuels have come into substantial use, in an extent that are claimed to be bigger than use of fossil oil. One driving force for this have been the CO2-tax that was introduced in 1991 (1). According to SVEBIO:s calculations (2) based on the Swedish Energy Agency´s prognosis, the total energy consumption in Sweden 2012 was 404 TWh. If the figure is broken down on the different energy sources (figure 1) one can see that the consumption roughly distribute in three different, equally sized, blocks, Biofuels, fossil fuels and water & nuclear power. The major use of the fossil fuels is for transport and the water & nuclear power is used as electric power. The main use of the biofuels is for heating in the industrial sector and as district heating. In 2009 the consumption from those two segments was 85 TWh, and 10 TWh of bio power was co-produced giving an average biomass to electricity efficiency of 12%. This indicates a substantial conversion potential from hot water production to combined heat and power (CHP) production. in Sweden 2013 broken down on the different energy sources. In 2006 the pulp, paper and sawmill industry accounted for 95% of the bio energy consumption in the industrial sector, and the major biofuel consumed was black liquor (5). However, the pulp and paper industries also produced the black liquor in their own processes. The major energy source (58%) for district heating during 2006 was woody biomass (chips, pellets etc.) followed by waste (24%), peat (6%) and others (12%) (5). The use of peat has probably decreased since 2006 since peat is no longer regarded as a renewable energy source. While the use of biofuel for heating purpose is well developed and the bio-power is expected to grow, the use in the transport sector is small, 9 TWh or 7% in 2011. The main consumption there is due to the mandatory addition (5%) of ethanol to gasoline and FAME to diesel (6). The Swedish authorities have announced plans to increase the renewable content to 7.5 % in 2015 on the way to fulfill the EU’s goal of 10 % renewable transportation fuels in 2020. However the new proposed fuel directive in EU says that a maximum of 5% renewable fuel may be produced from food sources like sugars and vegetable oils. Another bothersome fact is that, in principle, all rape seed oil produced in Sweden is consumed (95-97%) in the food sector, and consequently all FAME used (in principle) in Sweden is imported as FAME, rape seed oil or seed (6). In Sweden a new source of biodiesel have emerged, tall oil diesel. Tall oil is extracted from black liquor and refined into a diesel fraction (not FAME) and can be mixed into fossil diesel, i.e. Preem Evolution diesel. The SUNPINE plant in Piteå have a capacity of 100 000 metric tons of tall oil diesel per annum, while the total potential in all of Sweden is claimed to be 200 000 tons (7). 100 000 tons of tall oil corresponds to 1% of the total diesel consumption in Sweden. in Sweden for 2010 and a prognosis for 2014. (6). Accordingly, the profoundest task is to decrease the fossil fuel dependency in the transport sector, and clearly, the first generation biofuels can´t do this on its own. Biogas is a fuel gas with high methane content that can be used in a similar way to natural gas; for instance for cooking, heating and as transportation fuel. Today biogas is produced by fermentation of waste (municipal waste, sludge, manure), but can be produced by gasification of biomass, for instance from forest residues such as branches and rots (GROT in Swedish). To get high efficiency in the production, the lower hydrocarbons, mainly methane, in the producer gas, should not be converted into synthesis gas. Instead a synthesis gas with high methane content is sought. This limits the drainage of chemically bonded energy, due to the exothermic reaction in the synthesis step (so called methanisation). In 2011 0.7 TWh of biogas was produced in Sweden by fermentation of waste (6) and there were no production by gasification, at least not of economic importance. The potential seems to be large, though. In 2008 the total potential for biogas production, in Sweden, from waste by fermentation and gasification was estimated to 70 TWh (10 TWh fermentation and 60 TWh gasification) (8). This figure includes only different types of waste and no dedicated agricultural crops or dedicated forest harvest. Activities in the biogas sector, by gasification, in Sweden are the Göteborgs energi´s Gobigas project in Gothenburg and Eon´s Bio2G-project, now pending, in south of Sweden. If the producer gas is cleaned and upgraded into synthesis gas also other fuels could be produced. In Sweden methanol and DME productions are planned for in the Värmlands metanol-project and at Chemrecs DME production plant in Piteå.

  • 17.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Hulteberg, Christian
    Lunds Tekniska Högskola .
    Leveau, Andreas
    Biofuel-Solutions AB.
    Selective Catalysts for Glycerol Dehydration2013In: CRS-2, Catalysis for Renewable Sources: Fuel,Energy,ChemicalsBook of Abstracts / [ed] Vadim Yakovlev, Boreskov Institute of Catalysis, Novosibirsk, Russia: Boreskov Institute of Catalysis , 2013, p. 17-18Conference paper (Refereed)
    Abstract [en]

     There has been an increased interest over the last decade for replacing fossil based feedstock’s with renewable ones. There are several such feedstock’s that are currently being investigated such as cellulose, lignin, hemicellulose, triglycerides etc. However, when trying to perform selective reactions an as homogeneous feedstock as possible is preferable. One such feedstock example is glycerol, a side-product from biofuels production, which is a tri-alcohol and thus has much flexibility for reactions, e.g. dehydration, hydrogenation, addition reactions etc. Glycerol in itself is a good starting point for fine chemicals production being non-toxic and available in rather large quantities [1-2]. A key reaction for glycerol valorisation is the dehydration of glycerol to form acrolein, an unsaturated C3 aldehyde, which may be used for producing acrylic acid, acrylonitrile and other important chemcial products. It has recently been shown that pore-condensation of glycerol is an issue under industrial like conditions, leading to liquid-phase reactions and speeding up the catalyst activity and selectivity loss [3]. To address this issue, modified catalyst materials have been prepared where the relevant micro and meso pores have been removed by thermal sintering; calculations have shown that pores below 45 Å may be subject to pore condensation. The catalyst starting material was a 10% WO3 by weight supported on ZrO2 in the form of beads 1–2 mm and it was thermally treated at 400°C, 500°C, 600°C, 700°C, 700°C, 800°C, 850°C, 900°C and 1000°C for 2 hours. The catalysts were characterised using nitrogen adsorption, mercury intrusion porosimetry (MIP), Raman spectroscopy and ammonia temperature programmed desorption. The thermal sintered catalysts show first of all a decreasing BET surface area with sintering commencing between 700°C and 800°C when it decreases from the initial 71 m2/g to 62 m2/g and at 1000°C there is a mere 5 m2/g of surface area left. During sintering, the micro and meso-porosity is reduced as evidenced by MIP and depicted in figure 1. As may be seen in the figure, sintering decrease the amount of pores below and around 100 Å is reduced at a sintering temperature of 800°C and above. The most suitable catalyst based on the MIP appears to be the one sintered at 850°C which is further strengthened by the Raman analysis. There is a clear shift in the tungsten structure from monoclinic to triclinic between 850°C and 900°C and it is believed that the monoclinic phase is important for activity and selectivity. Further, the heat treatment shows that there is an increase in catalyst acidity measured as mmol NH3/(m2/g) but a decrease in the acid strength as evidenced by a decrease in the desorption peak maximum temperature.

     

  • 18.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Life cycle primary energy use and carbon footprint of wood-frame conventional and passive houses with biomass-based energy supply2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 834-842Article in journal (Refereed)
    Abstract [en]

    In this study the primary energy use and carbon footprint over the life cycle of a wood-frame apartmentbuilding designed either conventionally or to the passive house standard are analyzed. Scenarioswhere the building is heated with electric resistance heaters, bedrock heat pump or cogeneration-baseddistrict heat, all with biomass-based energy supply, are compared. The analysis covers all life cyclephases of the buildings, including extraction of raw materials, processing of raw materials into buildingmaterials, fabrication and assembly of materials into a ready building, operation and use of the buildings,and the demolition of the buildings and the post-use management of the building materials. Theprimary energy analysis encompasses the entire energy chains from the extraction of natural resourcesto the delivered energy services. The carbon footprint accounting includes fossil fuel emissions, cementprocess reaction emissions, potential avoided fossil fuel emissions due to biomass residues substitutionand end-of-life benefit of post-use materials. The results show that the operation of the buildingaccounts for the largest share of life cycle primary energy use. The passive house design reduces theprimary energy use and CO2 emission for heating, and the significance of this reduction depends onthe type of heating and energy supply systems. The choice of end-use heating system strongly influencesthe life cycle impacts. A biomass-based system with cogeneration of district heat and electricitygives low primary energy use and low carbon footprint, even with a conventional design. The amountof biomass residues from the wood products chain is large and can be used to substitute fossil fuels.This significantly reduces the net carbon footprint for both the conventional and passive house designs.This study shows the importance of adopting a life cycle perspective involving production, construction,operation, end-of-life, and energy supply when evaluating the primary energy use and climaticimpacts of both passive and conventional buildings.

  • 19.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Peñaloza, Diego
    SP.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Case studies: Wälluden as case study for three wooden structure systems, Chapter 8.22013In: Wood in carbon efficient construction: Tools, methods and applications / [ed] Kuittinen M., Ludvig, A. and Weiss, G, Finland: Hämeen Kirjapaino Oy , 2013, p. 114-123Chapter in book (Other academic)
  • 20.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Background: What is life cycle assessment and carbon footprint analysis? Chapter 2.22013In: Wood in carbon efficient construction: Tools, methods and applications / [ed] Kuittinen M., Ludvig, A. and Weiss, G., Finland: Hämeen Kirjapaino Oy , 2013, p. 15-15Chapter in book (Refereed)
  • 21.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    The role of wood in carbon efficient construction. Primary energy and greenhouse gas balances over the life cycle of different wood building systems: Swedish case-study building. €CO2 Work Package 12013Report (Other academic)
  • 22.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Primary energy and carbon dioxide implications of low-energy renovation of a Swedish apartment building2013In: Passivhus Norden 2013, 2013, p. 270-282Conference paper (Refereed)
    Abstract [en]

    Measures to improve energy efficiency in existing buildings offer a significant opportunity to reduce primary energy use and carbon dioxide (CO2) emissions. The construction of new low energy buildings is important in the long term, but has small effect on the building sector’s overall energy use in the short term, as the rate of addition of new buildings to the building stock is low. In this study we analyse the potential for reducing primary energy use and CO2 emissions in an existing Swedish apartment building with energy efficiency renovation measures. We model changes to a case-study building with an annual final heat energy demand of 94 kWh/m2 to achieve a low-energy building. The modelled changes include improved water taps, windows and doors, increased insulation in attic and exterior walls, electric efficient appliances and installation of a plate heat exchanger in the ventilation system. We analyse the life cycle primary energy and CO2 implications of improving the buildings to a low-energy building. We consider different energy supply systems, including scenarios where the end-use heating technology is resistance heating, electric heat pump or district heating. We find that greater lifecycle primary energy and CO2 reduction are achieved when an electric resistance heated building is renovated than when a district heated building is renovated. Material production primary energy use and CO2 emission become relatively more significant when the operation energy is reduced. However, the increases in material production impacts are strongly offset by greater primary energy and CO2 reductions from the operation phase of the building, resulting in significant lifecycle benefits. Additional roof insulation gives the biggest primary energy efficiency when the building is heated with resistance heating. For electric heat pump or district heating, more electric efficient appliances give the biggest primary energy efficiency. Still the heat supply choice has greater impact on primary energy use and CO2 emissions.

  • 23.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Building level   : full carbon footprint analysis, Chapter 4.5.22013In: Wood in carbon efficient construction: Tools, methods and applications / [ed] Kuittinen M., Ludvig, A. and Weiss, G., Finland: Hämeen Kirjapaino Oy , 2013, p. 47-51Chapter in book (Other academic)
  • 24.
    Dorn, Michael
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    de Borst, Karin
    Eberhardsteiner, Josef
    Experiments on dowel-type timber connections2013In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 47, p. 67-80Article in journal (Refereed)
    Abstract [en]

    Dowel-type connections are commonly used in timber engineering for a large range of structural applications. The current generation of design rules is largely based on empiricism and testing and lacks in many parts a stringent mechanical foundation. This often blocks an optimized use of the connections, which is essential for the design of economically efficient structures. Moreover, it severely limits the applicability of the design rule, such as restrictions regarding splitting behavior or maximum ductility (e.g. maximum allowable deformations) are missing. Therefore, the demands due to a large and quickly evolving variety of structural designs in timber engineering are not reflected. The aim of this work is to study the load-carrying behavior of the connection in detail, including all loading stages, from the initial contact between dowel and wood up to the Ultimate load and failure. Distinct features during first loading as well as during unloading and reloading cycles are identified and discussed. The knowledge of the detailed load-carrying behavior is essential to understanding the effects of individual parameters varied in relation to the material and the connections design. The suitability of the current design rules laid down in Eurocode 5 (EC5) is assessed and deficiencies revealed. Tests on 64 steel-to-timber dowel-type connections loaded parallel to the fiber direction were performed. The connections were single-dowel connections with dowels of twelve millimeter diameter. The test specimens varied in wood density and geometric properties. Additionally, the effects of dowel roughness and lateral reinforcement were assessed. The experiments confirmed that connections of higher density show significantly higher ultimate loads and clearly evidenced that they are more prone to brittle failure than connections using light wood. The latter usually exhibit a ductile behavior with an extensive yield plateau until final failure occurs. With increased dowel roughness, both, ultimate load and ductility are increased. The test results are compared with corresponding design values given by EC5 for the strength and the stiffness of the respective single-dowel connections. For connections of intermediate slenderness, EC5 provided conservative design values for strength. Nevertheless, in some of the experiments the design values overestimated the actual strengths considerably in connections of low as well as high slenderness. As for the stiffness, a differentiation according to the connection width is missing, which gives useful results only for intermediate widths. Furthermore, the test results constitute valuable reference data for validating numerical simulation tools, which are currently a broad field of intensive interest.

  • 25.
    Dorn, Michael
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Kozłowski, Marcin
    Silesian University of Technology, Poland.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Design approaches for timber-glass beams2014In: Glass, facade, energy : Engineered Transparency International Conference at glasstec: Conference on Glass, Glass Technology, Facade Engineering and Solar Energy, 21 and 22 October 2014 / [ed] Schneider, Jens and Weller, Bernhard, 2014Conference paper (Refereed)
    Abstract [en]

    This paper relates to the mechanical performance of timber-glass composite beams, which take exceptional advantage of the combination of the materials involved. Beam bending tests were performed with beams made from float glass and heat-strengthened glass. Three different adhesive types were used: silicone, acrylate and epoxy. The test results show that, with a proper design, the timber is able to transfer load after glass failure and hence collapse is delayed and a ductile behavior can be obtained. The results from the tests were compared with an analytical method using the gamma-method and the agreement between the analytical method and the tests are shown to be excellent.

  • 26.
    Ebba, Lejeby
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Metanpotential för alger och bioslam blandat med pappersfiber2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis the methane gas potential of three different substrates, two algaes Saccharina latissima and Laminaria digitata and biosludge mixed with paper fiber was studied. This was done by batch experiments in a laboratory environment to examine the gas production and composition of the produced gas.

    Biogas production is a complex anaerobic digestion process in which various microorganisms decompose the substrate in steps and at the end produce biogas and a residue. Many factors affect the production of gas, for example the substrate content, temperature and pH in the digester.

    The analysis of methane potential were divided into two experiments. In experiment 1 substrates were digested along with inoculum from Växjö waste water treatment plant in a temperature of about 37 ˚C. In experiment 2 substrates were digested along with inoculum from Kalmar Biogas AB at about 52 ˚C. Both experiments contained 15 bottles each with three replicates for each substrate: only inoculum, inoculum + Algae 1 (Saccharina latissima), inoculum + Algae 2 (Laminaria digitata), inoculum + Paper (biosolids mixed with paper fiber), inoculum + Reference (Cellulose). The inoculum and the reference were running to assess the quality of the inoculum.

    Mixtures between the inoculum and the substrate was first set to 5:1 and then 4:1, based on the material's VS-concentration. All experiments went on until gas production was minimal. For experiment 1 ,with the ratio of 5:1, the end results of the accumulated methane for Algae 1, Algae 2, Paper and Reference were 315, 313, 88 and 381 Nml CH4/g VS substrate respetively. The batch with inoculum + Paper was ended after seven days because the difference between inoculum + Paper and only inoculum was small.

    In experiment 1, with a ratio of 4:1, inoculum + Reference and inoculum batches were not prepared mainly because of lack of space.The batch with only inoculum was assumed to give the same results as in experiment 1, with the ratio of 5:1. The end results of the accumulated methane for Algae 1, Algae 2 and Paper were: 199, 214 and 41 Nml/g VS substrate repectively

    For experiment 2, with the ratio of 5:1, the end results of accumulated methane for Algae 1, Algae 2, Paper and Reference were: 191, 183, 33, 243 Nml/g VS substrate respectively

    In experiment 2, with the ratio 4:1, the end result of accumulated methane for Algae 1, Algea 2, Paper and Reference were: 288, 179, 18, 337 Nml/g VS substrate respectively.

  • 27. Eriksson, Jerry
    et al.
    Ludvigsson, Mikael
    Dorn, Michael
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Load bearing timber glass composites: A WoodWisdom-Netproject for innovative building system2013In: COST Action TU0905 Mid-term Conference on Structural Glass / [ed] Jan Belis; Christian Louter; Danijel Mocibob, Boca Raton, Fla: CRC Press, 2013Conference paper (Refereed)
    Abstract [en]

    The aim of this three year project, which is part of the WoodWisdom-Net researchprogram, is to develop an innovative load bearing building system composed of timberglasscomposites. The structural loads applied onto these composites will be transferred to, andsupported by, the glass component, in contrary to today’s traditional solutions where glass elementsonly function as an environmental shield. Using such structural elements will make itpossible to largely increase the glass surface in buildings, allowing the presence of more naturallight in personal homes and office buildings.

    Timber-glass shear walls and beams will be developed taking into consideration long-term behaviorand seismic performance. Design concepts, feasibility studies and performance assessmentsof these components will be performed in order to improve the overall performance. Theproject also includes the development of new design calculations as well as the optimization ofmanufacturing methods.

    Material properties of timber, glass and adhesives will be determined from small and large scaleexperimental investigations, and will be used as input for theoretical calculations and modelingwork. The projects industrial partners will function as expertise and take part in the developmentand construction of demonstration objects.

    The project consortium is composed of academic and industrial partners from Austria, Sweden,Germany, Turkey, Slovenia, Chile, and Brazil. This paper presents material specifications andresults from small scale testing performed by the Swedish project partners.

  • 28.
    Forss, Jörgen
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindh, Markus V.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Welander, Ulrika
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Microbial diversity in a continuous system based on rice husks for biodegradation of the azo dyes Reactive Red 2 and Reactive Black 52013In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 130, p. 681-688Article in journal (Refereed)
    Abstract [en]

    In the present study the degradation of two common azo dyes used in dye houses today, Reactive Black 5 and Reactive Red 2 was evaluated in biofilters. In two experiments, bioreactors performed over 80% decolorization at a hydraulic retention time of only 28.4 h with little production of metabolites. Molecular analyses showed a diverse and dynamic bacterial community composition in the bioreactors, including members of the Bacteroidetes, Acinetobacter (Gammaproteobacteria) and Clostridium (Firmicutes) that possess the capacity to reduce azo dyes. Collectively, the results indicate that the development of mixed bacterial communities from natural biomaterials contributes to an efficient and robust degradation performance in bioreactors even at high concentration of dyes.

  • 29.
    Guo, Yifan
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Wahlqvist, Malin
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Miljöbyggnad i praktiken: Att miljöcertifiera Hus N på Linnéuniversitetet2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport beskriver utförandet av en miljöcertifieringsprocess enligt systemet Miljöbyggnad på en befintlig byggnad. Hus N på Linnéuniversitetet i Växjö har valts som referensfall. Med hjälp av utvärderingar och jämförelser mellan teorier och bedömningar på Hus Ns nuvarande energi-, inneklimats- och materialsprestanda, har byggnaden fått Silver som slutbetyg. Miljöbyggnad värderas ytterligare med hänsyn till dess användarvänlighet, nytta och brister.

  • 30.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Greenhouse gas and primary energy balances overbuildings life cycle2013In: Lifecycle greenhouse gas and primary energy balances of a building. International Holzbau-Forum Nordic (IHN 13), May 23-24, 2013, Kouvola, 2013Conference paper (Other academic)
  • 31.
    Gustavsson, Leif
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Mötzl, Hildegard
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Fundamentals: greenhouse gas and primary energy balances over a building life cycle2013In: Wood in carbon efficient construction: Tools, methods and applications / [ed] Kuittinen M., Ludvig, A. and Weiss, G., Finland: Hämeen Kirjapaino Oy , 2013, p. 24-31Chapter in book (Refereed)
  • 32.
    Hakeem, Abbas Saeed
    et al.
    King Fahd University of Petroleum & Minerals (KFUPM).
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Preparation and properties of mixed La–Pr silicate oxynitride glasses2013In: Journal of Non-Crystalline Solids, ISSN 0022-3093, E-ISSN 1873-4812, Vol. 368, p. 93-97Article in journal (Refereed)
    Abstract [en]

    The preparation and properties of mixed lanthanide (La, Pr) silicate oxynitride glasses are reported. These oxynitride glasses were prepared by melting mixtures of La, Pr, SiO2 and Si3N4 powders in a nitrogen atmosphere at 1750 °C. The glasses were characterized by X-ray powder diffraction, differential thermal analysis, scanning and transmission electron microscopy. Glass compositions were calculated from the analyses obtained by energy dispersive X-ray (EDX) spectroscopy and combustion analysis, for cation and anion compositions, respectively. The glasses were found to be homogenous, optically opaque black, and to contain contents up to 66 e/o of N and up to 48 e/o of La–Pr. The physical properties were found to vary linearly with the degree of substitution of La by the Pr. Determined glass density increases substantially upon the substitution of La by Pr, up to 5.49 g/cm3. The calculated molar volumes and compactness values decrease and increase respectively by the substitution of Pr for La. Glass transition temperatures and microhardness increase upon the substitution by Pr, up to 1086 °C and 10.98 GPa, respectively. The refractive index increases upon the substitution by Pr up to 2.00.

  • 33.
    Harnesk, Emma
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Roos, Hannah
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Vacker utan spackel: Uppmuntransbidrag till korrekt fasadrenovering inom Uppvidinge kommun2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Uppvidinge kommun vill ta fram ett uppmuntransbidrag för fasadrenovering. Avsikten är att försöka bevara husens karaktär genom metod- och materialval och rapporten inriktar sig därför på byggnadsvård och varsamhetsprincipen. 

     

    Rapporten tar fram kriterier som hjälp till kommunen för att besluta om utdelande av bidrag. Den innehåller också generell information om olika fasad- och takmaterial samt fönster. Rapporten och kommunens önskemål sammanfattas i en broschyr som kan användas som informationsspridning till intresserade fastighetsägare.

     

    Rapporten använder sig dessutom av en enkät för att undersöka människors attityd och kunskaper kring fasader och renovering.

     

  • 34.
    Haus, Sylvia
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Greenhouse Gas Emission Comparison of Woody Biomass Systems with the Inclusion of Land-use in the Reference Fossil System2013In: 21st European Biomass Conference & Exhibition, Copenhagen, June 3-7, 2013, ETA-Florence Renewable Energies, , 2013, p. 1794-1799Conference paper (Refereed)
    Abstract [en]

    While issues of land-use have been considered in many analyses of biomass systems, little attention has heretofore been paid to land-use in reference fossil systems. In this study we address this limitation by comparing forest biomass systems to reference fossil systems with explicit consideration of land-use in both systems. We estimate and compare the time profiles of greenhouse gas (GHG) emission and cumulative radiative forcing (CRF) of woody biomass systems and reference fossil systems. A life cycle perspective is used that includes all elements of both systems and all GHG emissions along the full material and energy chains. We consider the growth dynamics of forests under different management regimes, as well as energy and material substitution effects. We determine the annual net emissions of CO2, N2O and CH4 for each system over a 240-year period. We then calculate time profiles of CRF as a proxy for climate change impacts. The results show greatest CRF reduction when fertilized forest management is applied in the woody biomass system. The results show the relevance of including land use options in both the biomass and the fossil system to accurately determine the climate impacts and benefits of forest management and product use.

  • 35.
    Hemström, Kerstin
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Public perceptions and acceptance of intensive forestry in Sweden2014In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 43, no 2, p. 196-206Article in journal (Refereed)
    Abstract [en]

    The use of intensive forestry on part of the forested area in Sweden increases the production of forest biomass and enables an increased use of such biomass to mitigate climate change. However, with increasing conflicting interests in forests and forestry, the success of such a strategy depends on the public acceptance. In this paper, the results of a mail survey show that although a majority of the general public in Sweden supports measures to increase forest growth, they oppose the use of intensive forestry practices such as the cultivation of exotic tree species, clones, and forest fertilization. The acceptance of such practices is mainly influenced by the perceptions of their environmental consequences. Public acceptance was highest for forest fertilization, whereas clone cultivation was the least accepted practice.

  • 36.
    Hemström, Kerstin
    et al.
    Mittuniversitetet.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Swedish private forest owners’ perceptions and intentions with respect to adopting exotic tree species2013In: European Journal of Forest Research, ISSN 1612-4669, E-ISSN 1612-4677, Vol. 132, no 3, p. 433-444Article in journal (Refereed)
    Abstract [en]

    Swedish forest growth can be increased through intensive forestry practices, enabling an increased use of forest biomass for climate-change mitigation. However, the diffusion of such practices depends on the forest owners’ adoption of them. We study Swedish private forest owners’ perceptions and intentions with respect to increasing forest growth by adopting exotic tree species. The results of a mail-in questionnaire survey show that although a majority of forest owners desire increasing forest growth, most owners have only a basic understanding of exotic tree species and a smaller proportion is interested in adopting them. The intention to adopt exotics seems to depend on the perceived performance of the species with respect to the economic aspects of forest management rather than on environmental or recreational concerns. Whereas a knowledge gap among the private forest owners regarding how to increase forest growth is implied, forest owners with higher self-rated knowledge of forestry and exotics have stronger intentions to adopt such species.

  • 37.
    Hu, Min
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Comparison of local variation of modulus of elasticity determined on basis of scanned fiber angles and full strain field measurements2013In: The 18th International Nondestructive Testing and Evaluation of Wood Symposium, Madison, WI, USA, 2013Conference paper (Refereed)
    Abstract [en]

    Strength grading methods are normally based on relationships between one measured value of modulus of elasticity (MOE), regarded as being valid for the whole board, and bending strength. Studies have shown, however, that with a detailed knowledge of local variation of MOE within boards, a highter coefficient of determination (R2) with respect to bending strength can be obtained. Measurements of fiber angles from laser scanning has shown to be a powerful tool to establish MOE profile along boards in a speed that cooresponds to the production speed at a sawmill. The present study aims at investigating the accuracy of the local MOE profile determined on basis of fiber angles from laser scanning. The study was carried out on a board of Norway spruce of dimension 50 by 150 by 3,900 mm. First the fiber angles on all four surfaces were identified using a WoodEye scanner and on the basis of these measurements, a MOE profile was calculated. Thereafter, the board was subjected to a constant bending moment and suring loading an image correlation system, Aramis, was employed for detection of the strain field with high resolution along the whole board. This strain field was then used to estanlish a 'true' MOE profile along the board. The MOE profiles determined in two different ways were compared and they show a close compliance. However, some difference were found and these were used for calibration of the method for MOE determination on the basis of scanning results. The present research thus contributes further improvement of a newly suggested grading method.

  • 38.
    Högberg, Karl-Anders
    et al.
    Skogforsk.
    Hallingbäck, Henrik
    SLU.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jansson, Gunnar
    Skogforsk.
    The potential for the genetic improvement of sawn timber traits in Picea abies2014In: Canadian Journal of Forest Research, ISSN 0045-5067, E-ISSN 1208-6037, Vol. 44, no 4, p. 273-280Article in journal (Refereed)
    Abstract [en]

    This study evaluated the potential for the selective genetic improvement of the structural quality traits important in sawn Norway spruce (Picea abies (L.) Karst.) timber based on early and nondestructively assessed field traits. From a 34-year-old Norway spruce trial situated in southern Sweden, 401 butt logs were sampled and sawn to produce two 50 × 100 mm boards that were dried to an 18% moisture content. Structural quality traits were assessed, and genetic parameters were estimated, including additive genetic variance, heritability, and their genetic correlations with field traits. Board twisting, density, and modulus of elasticity (MOE, stiffness) were found to have appreciable heritabilities (0.23–0.44). Board twist was found to have a strong genetic correlation with grain angle measured under bark in the field (0.93), and both board MOE and density exhibited strong genetic correlations with field-assessed pilodyn penetration (–0.75 and –0.91, respectively). Although these observations were made on a thinning material comprising mainly juvenile wood, they nonetheless suggest grain angle and pilodyn penetration to be promising candidates as selection criteria for Norway spruce breeding. Heritabilities of other sawn timber traits were lower and the genetic correlations between these traits and field traits were also lower, variable, and had large estimation errors.

  • 39.
    Ingemansson, Tobias
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Klassificering av explosiva områden från biogasproduktion2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Linnéuniversitetet har i utbildnings- och forskningssyfte för avsikt att via anaerob nedbrytning av organiskt material framställa biogas. Två olika typer av biogasreaktorer har konstruerats för detta ändamål. Det som särskiljer dem är tillvägagångsättet att mixa det rötningsbara substratet. Reaktorerna är byggda i pilotskala.

    Vid anaerob nedbrytning av organiskt material bildas explosiva och lättantändliga gaser. Huvudsakligen metangas, upp till 70 %, men även mindre mängder av vätgas. Metangas blandat med luft är explosivt i koncentrationerna 4,4-17,0 volymprocent metan och vätgas är explosivt i koncentrationerna 4,0-77,0 volymprocent. Med en felmarginal på                         10 % för undre explosionsgräns och 5 % för övre gränsen. Vid framställning och hantering av sådana gaser krävs tillstånd från räddningsverket. För att erhålla detta krävs en klassificeringsplan gjord utefter räddningsverkets författningar.

    Den befintliga anläggningens kapacitet har beräknats varpå dess maximala produktion av explosiva och lättantändliga gaser har använts som bas. Därefter har en genomgång gällande ventilation, antändningskällor, eventuella riskzoner och övriga säkerhetsföreskrifter gjorts. Detta enligt  räddningsverket författningar. Genomgången visar att det finns två riskzoner i containern i vilka biogasreaktorerna är placerade. Området från reaktorernas lock och upp till taket är en klass 2 vilket innebär att ingen explosiv gasblandning förväntas uppstå under normal drift. Den andra riskzonen är inuti rötkamrarna. Även detta område klassas som en typ två zon. Metangas förväntas förekomma kontinuerligt inuti rötkamrarna men då rötprocessen sker anaerobt finns ingen tillgång till syre. Detta medför att inget riskområde finns under drift. Vid uppstart av ny process finns tillgång till syre, men bara under begränsad tid. Syret bryts ner snabbt i processen och förväntas vara helt nedbrytet innan metangasnivån har nått upp till undre explosionsvärdet, som är 4,4 %.

    Vid ett eventuellt läckage från systemet kommer metangasen stiga uppåt mot taket av containern. Detta då gasen har lägre densitet än den omgivande luften. I taket ovanför reaktorerna placeras en ventil med fläkt för att avlägsna gasen snabbare ur containern.

    För områden som klassas som en zon 2 krävs att utrustningen uppfyller normen för kategori 3 utrustningsgrupp II. Detta innebär att utrustningen inte får vara en antändningskälla under normal drift och att den är CE märkt. Ventilationsflödet för klass 2 området har beräknats behöva vara minst 9 m3/h för att anses vara medelgod. ”Vilket innebär att ventilationen kan reglera koncentrationen så att en stabil zongräns uppstår medan utsläppet pågår och där explosiv gasblandning inte kvarstår någon längre tid efter att utsläppet upphört.”

    Vid vissa arbetsmoment ökar risken för uppkomst av explosiva gasblandningar i containern så som när det organiska substratet skall avlägsnas från reaktorerna. Därför finns specifika säkerhetsföreskrifter för detta moment. För ökad ventilation och för säkerställning att inget riskområde finns skall containerporten vara öppen på vid gavel i 10 minuter innan arbetet startar. Endast en reaktor öppnas i taget och strömmen till reaktorernas utrustning skall vara bruten. Dock skall huvudströmmen vara påslagen så ventilationssystemet fungerar. Vid strömavbrott eller haveri av containerns ventilationssystem ökar risken för uppkomst  av explosiva gasblandningar. Därför skall vid ett sådant scenario containerporten hållas öppen på vid gavel i 30 minuter innan inträde i containern.

    För information av de beräkningar som gjort under genomgången, se respektive avsnitt i rapporten.

     

  • 40.
    Jakesevic, Ana
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Dahlström, Rebecka
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Hur kan ett område utvecklas till att bli en attraktiv plats att bo på?2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Hur kan ett område utvecklas till att bli en attraktiv plats att bo på? I examensarbetet besvaras denna fråga bland annat utifrån intervjuer med personer som på olika sätt har varit inblandade i de olika projekt och projekteringsplaner som diskuteras/berörs i arbetet och utifrån enkäter genomförda bland anställda på IKEA. Enkätstudien genomfördes ursprungligen med syfte att utreda anställdas inställning till IKEA och Älmhult. Bland dem som fyllt i den finns både sådana som redan bor i Älmhult och sådana som i dagsläget pendlar in till Älmhult.

    En förutsättning för arbetet var att ett nytt område för exploatering skulle kunna utvecklas i form av en bomässa och därför har även en kartläggning av och jämförelse mellan ett antal tidigare bomässor genomförts. Frågor som behandlas är vad som har varit utmärkande för dessa bomässor och vad som har gett dem genomslagskraft. Idéer och förslag presenteras i form av översiktliga planer och beskrivningar som kopplar till intervjuer, enkätsvar och analyser

  • 41.
    Jakobsson, Oskar
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Green, Max
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jämförelse av frånluftsvärmepumpar2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order to reach the environmental targets, set up by the EU, there are many measures taken to make Sweden more energy efficient. In the housing and real estate sector, an installation of an exhaust air heat pump that reuses the heat in the exhaust air in order to lower the amount of acquired energy, is an example of such an action. The recovered energy can then be used for heating of radiators and tap water. This report aims to evaluate and compare three different systems using exhaust air heat pumps regarding COP, degree of coverage and cost savings. This study was delimited to only account for apartment buildings.The theory chapter describes the different conditions and factors that affect a building’s energy balance. Further on the exhaust air heat pump is described with focus on function, limitations and advantages regarding energy savings.The first one is located on Västergatan 21 in Växjö and uses recirculation of the exhaust air to increase the air flow through the heat pump. The second system is installed on Toras väg in Karlskrona. This system uses a mix of exhaust air and outside air. The last system on Södra järnvägsgatan in Växjö only uses the exhaust air in its heat pump.The COP for the different installations was 1,89 for Toras väg (average), 3,14 and 3,47 for Västergatan and 3,80 for S. järnvägsgatan for the respective period. The degree of coverage for the installations was in the interval 56,3 – 91,0% and the cost savings was between 4 900 SEK to 8 600 SEK per month for the observed period of each building.

  • 42.
    Jarnerö, Kirsi
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Vibrations in timber floors: Dynamic properties and human perception2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Springiness and vibrations of timber floors are familiar to many as a ‘live’ feelwhen walking on them, especially if living in single family housing with timberframework. Since the building regulations in Sweden changed to performancedependentrequirements in 1994 the use of timber in multifamily housing hasincreased. New timber building systems have been developed and increasedbearing capacity of floors has made it possible to build with longer spans. Thelow mass of timber floors makes them more sensitive to dynamic loading byhuman activities, such as walking, running and jumping, compared to heavyfloors e.g. concrete floors. To improve vibration performance it is possible tochange the structural properties of the floors by increasing mass, stiffness ordamping properties. The most practicable solution is to increase the stiffness.Improved damping is also highly effective, but is difficult estimate and designaccurately since it originates from many sources in the finished building. In thepresent thesis the effects on dynamic properties from increased stiffnesstransverse to the load bearing direction of a floor have been assessed from testsin laboratory. The effect on dynamic performance of a timber floor fromelastic/damping interlayers (polyurethane elastomers) installed in the junctionsbetween walls and floors have been assessed in laboratory and in situ. Also thechange in dynamic properties of an in situ floor has been investigated atdifferent stages of construction and compared with results from laboratory tests.The present criteria for design of timber floors with respect to vibrationperformance were developed at a time when timber floors were mainly used insingle-family housing. The traditional timber joist floors differ in structuralbehaviour from the new types of floors developed recently. The experiencedvibration annoyance by residents in single- and multifamily housing differs asthe source of vibration disturbance and those who become disturbed aredifferent. The changed conditions give cause for a review of present designcriteria. A laboratory and field study on vibration performance was conductedwith questionnaires and dynamic performance measurements. The subjectiveand objective results were correlated and indicators for vibration acceptabilityand annoyance were assessed and new vibration performance criteria andvibration performance classes were suggested.

  • 43.
    Jeppsson, Magnus
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Björkman, Gustaf
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Förslag till utformning av stadsdelen Nya Haganäs & IKEA:s planerade Life@Home-mässa i Älmhult2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Hur bör en Life@Home-mässa i Nya Haganäs utformas för att attrahera, skapa publicitet och få folk att bosätta sig på orten? Svaret på den frågan undersöks i denna rapport. Bostadsbrist leder till ett behov att expandera och en mässa kan ge orten mer publicitet och intresse som genererar underlag för nybyggnationer och immigration.

    Metoden utgörs av litteraturstudier kring stadsplanering, intervjuer med ämneskvalificerade personer, studiebesök och undersökningar av relevanta bomässor. En deltagaraktiv stadsplaneringsmetod används och ligger till grund för en 3D-modell som har tagits fram. Detta utförs med hjälp av dator och resultatet presenteras i form av renderingar.

    Diskussionen kretsar kring hur kvalitéer varierar vid olika utformningar av planen, planens utseende och hur väl den uppfyller målen. Slutsatser dras, vilka står som grund för ett kvalitetsprogram för vad Life@Home-mässan kan innehålla. Dessutom dras övergripande slutsatser för hela Nya Haganäs.

  • 44.
    Jockwer, Robert
    et al.
    Empa, Switzerland;Swiss Fed Inst Technol, Switzerland.
    Frangi, Andrea
    Swiss Fed Inst Technol, Switzerland.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Steiger, Rene
    Empa, Switzerland.
    Enhanced design approach for reinforced notched beams2013In: PROCEEDINGS OF THE CIB - W18: WORKING COMMISSION W18 - TIMBER STRUCTURES / [ed] Gorlacher, R, 2013, p. 71-84Conference paper (Refereed)
  • 45.
    Jogre, Ida
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Mohager, Lina
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Förslag på utformning av Tingsryds travbana för att skapa en attraktiv och publikvänlig yttre miljö2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utreder och ger förslag på hur utemiljön kring Tingsrydtravets anläggning kan utformas för att bli attraktivare för olika arrangemang såväl inom hästsport som för andra verksamheter.

    Resultatet av rapporten är uppdelat i två förslag, det första förslaget skall vara realiserbart inom ett till två år samt till så låg kostnad som möjligt. Det andra förslaget är en utopisk framtidsvision utan hänsyn till ekonomiska begränsningar.

    Alla gestaltningsförslag är utformade med stark inspiration från småländsk natur och byggnadskultur. För att bevara och förstärka travanläggningens lokala karaktär har material och utformning av byggnader etcetera valts för att efterlikna småländsk, lantlig bebyggelse från förra sekelskiftet.

    Genom att förbättra anläggnings estetiska värden strävar Tingsrydtravet efter att förbättra besökarnas upplevelse, dra mer publik samt få möjlighet att vara arrangörer för fler evenemang. Med Tingsrydtravet som centrum hade detta på sikt bidragit till en utveckling av landsbygden kring Tingsryd, det så kallade ”Hästriket”.

     

  • 46.
    Johansson, Marie
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Lundqvist, Sven-Olof
    Innventia.
    Properties of materials from Birch – Variations and relationships: Part 2. Mechanical and physical properties2013Report (Other academic)
    Abstract [en]

    Birch regarded as Sweden’s third largest tree species. The two birch species, Silver- and Downy birch represents about 12% of total Swedish timber volume. For forestry, birch an important tree species which today mainly used for the manufacture of pulp and paper.

    The aim of this project was to describe mechanical and physical properties of birch. The properties that have been studied are stiffness, bending strength, shrinkage, spiral gran angle, density and microfibril angle in the cell wall and vessel cells, from different parts of the birch stems grown at different rates. The mapped properties have been compared also with those of other tree species, mainly spruce. The long term aim is to increase the knowledge of the birch wood properties to provide better predict their impact on products as well as provide a basis for better utilization of Swedish birch raw material and hopefully using birch as future structural timber.

    Three birch stands with different growth was chosen: Two stands where the birch growth has been different in a mixed forests stand of spruce and pine, and a fast growing stand with improved birch seedlings. Samples were taken from four different heights in the trees. The main thing that has been analyzed is the bending strength, modulus of elasticity, shrinkage coefficients in different directions and spiral grain. The mechanical tests are carried out on tines that are 20 x 20 x 300 mm and the fiber angle measurements were carried out on discs. These results have supplemented by the results of analyzes conducted with lnnventias SilviScan instruments that are able to recognize variations of year ring wood properties. Some of these are density, and microfibril angle, which is also included in this report.

    The results show that the wood from normal growth and fast growth improved birch receive equivalent wood properties. The results also show that birch wood properties are slightly better than that in Norway spruce.

    The material in this project was limited to only three stands and 11 sampled trees and therefore it can´t provide complete answers to the birch trees different wood properties. Limitations include genetic origin, growth rate, earlier silvicultural treatment and number of sample trees.

  • 47.
    Johansson, Martina
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Petersson, Johanna
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Miljökonsekvenserna av Växjö kommuns energikrav på bostäder på Östra Lugnet2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I detta examensarbete studeras miljökonsekvenser av Växjö kommuns ställda energikrav på bostadsområdet Östra Lugnet i Växjö. Dessutom studeras hur väl Växjö kommuns och BBRs (Boverkets byggregler) krav på specifik energianvändning efterlevs. Växjö kommuns krav ställs på både företag och privatpersoner där kravet innefattar anslutning till Växjös fjärrvärmenät. Kommunen ställer också krav på företag gällande specifik energianvändning.

     

    Denna studie uppvisar skillnader, både mellan företag och privatpersoner men även mellan företags olika kvarter, i hur väl ställda energikrav efterlevs. Där lyckas företagen sämst, trots att de haft strängare krav.

     

    Studien visar också att fjärrvärme bidrar till en minskning av koldioxidutsläpp, vilket stöder Växjö kommuns kravställande på fjärrvärmeanslutning.

  • 48.
    Jonson, Bo
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Stålhandske, Christina
    Glafo, SE-35196 Vaxjo, Sweden.
    Devitrification and dilatometric properties of low T-g unleaded silicate glasses2013In: European Journal of Glass Science and Technology. Part A: Glass Technology, ISSN 1753-3546, Vol. 54, no 3, p. 108-110Article in journal (Refereed)
    Abstract [en]

    Candidate lead free glass enamels have been sought within the glass system described in general terms by the mole fractions 0.25R(2)O center dot 0.16(R'O,R-2 '' O-3)center dot 0.59SiO(2) where R=Li, Na, K; R'=Ba, Zn and R ''=B, Bi. Glass compositions containing high mole fractions of Li2O were found to devitrify when they were heated to temperatures up to 530 degrees C typical for the procedure used when fusing enamels to tableware glasses. The devitrification characteristics are complex and several peaks attributed to crystallisation were found by DSC characterisation. The thermal expansion coefficient (alpha) within the system ranges from 11-14x10(-6) K-1 and the glass transition temperatures (T-g) between 410-460 degrees C. The measured data could be fitted to the chemical composition by multiple regression analysis with a general equation of the form: (alpha,T-g)=K((alpha/Tg))+Sigma(cRxfR) in which K is a constant, c is the oxide mole fraction and f is an oxide specific factor. The statistical analysis correlation coefficients (r(2)) were around 0.9.

  • 49.
    Kans, Mirka
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Rupar-Gadd, Katarina
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gunnarsson, Anette
    School-wide approach for the degree project courses2013In: Proceedings of the 9th International CDIO Conference, Massachusetts Institute of Technology and Harvard UniversitySchool of Engineering and Applied Sciences, Cambridge, Massachusetts, June 9 – 13, 2013.: Engineering Leadership in Innovation and Design, 2013Conference paper (Other academic)
    Abstract [en]

    The poster contains a practical example of how the CDIO concept can be used for developing common course contents with the aim to improve the students’ generic and professional competences. The overall purpose is to create a school-wide spirit of community for the students and introduce CDIO for faculty.

    OBJECTIVES

    1. Ideas for how to coordinate school-wide activities aiming at increasing students’ generic skills and professional identity

    2. Strategies for introducing the CDIO concept for the school faculty members

    DESCRIPTION

    For reaching high employability, students require knowledge and skills connected to the future working area, as well as generic skills and a professional attitude [1]. Ensuring these abilities is a major challenge of higher education today [2-4]. All these abilities are trained in the final independent work, where students, normally in collaboration with industry, acts as professionals while fulfilling the goals of academy. In the past, every subject had their own way of running the degree courses, but a need to coordinate the efforts for assuring the required outcome has gradually evolved. This emerging need was used as an opportunity to introduce CDIO thinking on school level, because most staff is involved in the degree project courses. Activities open for all students, such as joint introduction and lectures, workshops in literature search and a final dinner together with industry collaborators, are offered during the final semester, and general tools supporting the process have been developed, covering templates for report writing, a common web portal and a web based tool for registering of degree theses. The approach is extended with faculty pedagogic development activities, such as discussion meetings regarding generic skills training and the tutors’ role in the learning process.

  • 50.
    Karim, Ali Abdul Jabbar
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Lessner, Johan
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Moridnejad, Mehrdad
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Model calibration of a wooden building block2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Constructing multi floor buildings by light weight material have increased recently. There are many advantages of using light weight material, such as wood, for the environment. However, one of the deficiencies of lightweight material is the acoustic performance. Transmission of sound and vibration through floors in multi floor buildings in wood is a drawback to be considered. There are many studies that have addressed this issue.

    It is most common to make a finite element models well as experiments in laboratory. In these studies the material properties in the FE model are probably often adjusted to correlate to the laboratory experiments, since there is a large spread in material properties found in literature.

    This thesis however tries to elaborate on the actual material properties of the included wooden elements. Dynamic testing is done to determine the spread (here spread means gap between material properties) in material properties of wooden elements.

    The materials tested are chipboards and two types of wooden beams. The examined beams are both normal wooden beams and laminated veneer lumber beams. When the dynamic behaviour is known for the wooden parts, they are assembled to two small floor systems. The floor systems consist of four beams and one wooden board. The assembly is dynamically tested in laboratory and in FE software. The FE model used the known material properties for each individual building part.

    The results from the FE model correlate well with the laboratory tests. This shows that when material properties are known a FE model can predict the real behaviour. However, the examined material properties show a large spread from beam to beam, etc and a better knowledge about the material properties of used wooden parts is needed.

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