miun.sePublications
Change search
Refine search result
3456789 251 - 300 of 768
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 251.
    Grönlund, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Falk, Stefan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Hanæus, J
    Productive treatment of wastewater with microalgae in cold climate -laboratory experiments2001In: Ecological Engineering for Landscape Services and Products. The Annual Conference of the International Ecological Engineering Society, November 25th to 29th 2001, Christchurch, New Zealand., Christchurch, New Zealand, 2001Conference paper (Other academic)
  • 252.
    Grönlund, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Johansson, E
    Hanaeus, J
    Falk, Stefan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Seasonal microalgae variation in a subarctic wastewater stabilization pond using chemcial precipitation2004In: Vatten, ISSN 0042-2886, Vol. 60, no 4, p. 239-249Article in journal (Refereed)
    Abstract [en]

    Surface water microalgae samples were collected during the ice-free period in a small subarctic wastewater stabilization pond system, complemented with chemical precipitation during the winter period (fellingsdam), and serving 310 persons. In the primary pond microalgae dominance alternated between the Cryptophyte Cryptomonas and green algae (Chlorophyta). In the second and third pond the general pattern was that Cryptomonas dominated during summer but was replaced by green algae in autumn and the following spring. Estimations of the microalgae part of the effluent COD and phosphorus showed that microalgae dominated these parameters for only 3-4 weeks of 12 evaluated. This does not support the reasoning behind the European Union directive of the use of filtered samples for effluent BOD, COD and SS from stabilization ponds, in contrast to other wastewater treatment methods. The reasons behind the EU's procedure for ponds are based on the assumption that stabilization ponds convert "sewage BOD" to "algal BOD". The results of this study suggest that further investigations of the microalgae function in subarctic wastewater stabilization ponds and fellingsdams should be conducted, before implementing the EC directive into Swedish law, or into similar laws in other countries with subarctic regions.

  • 253.
    Grönlund, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Klang, Anders
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Falk, Stefan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Hanaeus, Jörgen
    Sustainability of wastewater treatment with microalgae in cold climate, evaluated with emergy and socio-ecological principles2004In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 22, no 3, p. 155-174Article in journal (Refereed)
    Abstract [en]

    The sustainability of a microalgae wastewater treatment plant model (ALGA), assumed serving a small Swedish town with 10,000 inhabitants at latitude 60°N, was tested by comparing it to a conventional three-step treatment plant (WWTP), and a mechanical and chemical treatment plant (TP) complemented with a constructed wetland (TP + CW). Using two assessment methods—the socio-ecological principles method and emergy analysis—the ALGA model considered to have a better position for sustainable development, than the other two. In emergy terms the ALGA model had about half the resource use of the other two alternatives, and used most local free environmental resources, four times the TP + CW, and 100 times the WWTP. The violations against the second and third socio-ecological principles were considered equal for the three alternatives, the fourth was estimated to be in favor of the ALGA model, and the first principle was calculated to be in favor of the ALGA model with about eight times lower indicator value sum. Recirculation of nutrients back to society or production of economically viable products from the treatment by-products would strongly influence the sustainability. The ALGA model has a potential advantage due to interesting biochemical contents in the microalgae biomass, depending on what species will become dominating.

  • 254.
    Grönlund, Erik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Klang, Anders
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Vikman, Per-Åke
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Emergy and socio-ecological principles in sustainability assessment. Methodological considerations from a wastewater treatment case study2005In: Emergy Synthesis 3: Theory and Applications of the Emergy Methodology / [ed] Brown, M.T., D. Campbell, V. Comar, S.L. Huang, T. Rydberg, D.R. Tilley, S. Ulgiati,, Gainesville: University of Florida, 2005, p. 345-354Conference paper (Refereed)
    Abstract [en]

    Emergy analysis and socio-ecological principles were used for sustainability assessment in a wastewater treatment case study. A constructed model of a microalgae wastewater treatment plant (ALGA), assumed located in Sweden at latitude 60°N, was tested by comparing it to a conventional three-step treatment plant (WWTP), and a mechanical and chemical treatment plant complemented with a constructed wetland (TP+CW). Based on the results from the two assessment methods the ALGA model were considered having a better position for sustainable development, than the other two. In emergy terms the ALGA model had about half the resource use of the other two alternatives, the highest relative use of local free environmental resources, and the best emergy sustainability index (ESI). The violation against the 2nd and 3rd socio-ecological principles were considered equal for the three alternatives. The 4th was estimated to be in favour of the ALGA model, and the 1st principle was calculated to be in favour of the ALGA model with about 8 times lower indicator value. This paper focus on the methods used in the case study. The performance of the methods is compared, including a discussion on how they relate to the concept of sustainability. The two methods were developed from very different starting points, and use different assessment parameters. Regardless of this, the ranking of different options comes out identically, indicating that both methods are equally useful for assessments of sustainability in the studied system.

  • 255.
    Grönvik, Jan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Chavez-en studie i ledarskap2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med uppsatsen var att studera och analysera Chávez ledarskap utifrån teorier om ledarskap. Frågeställningarna gällde hur Chávez ledarskap sett ut under olika skeenden, om det förändrats över tiden och om han anpassade sitt ledarskap. Avgränsningen innebar att bara Chávez ledarskap som president undersöktes. Metoden bestod i att studera litterära källor och hade inslag av deduktiv ansats, hermeneutiskt synsätt och kvalitativt tillvägagångssätt. Resultatet visade att Chávez i sitt ledarskap uppvisar alla de tre ledarstilar som undersökts i uppsatsen: auktoritär, demokratisk och laissez-faire i olika kombinationer. Slutsatser som drogs var att i de skeenden där han var pådrivande dominerade auktoritär och demokratisk, skeenden som han inte tagit initiativet till dominerades av laissez-faire. Förslag till fortsatt forskning bestod i att genomföra enkäter och intervjuer med såväl Chávez som hans omgivning på spanska rörande hela hans ledarskap samt att undersöka fler ledare.

  • 256.
    Gulliksson, Mårten
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Jin, Xiao-Qing
    Wei, Yi-Min
    Perturbation bounds for constrained and weighted least squares problems2002In: Linear Algebra and Its Applications, ISSN 0024-3795, Vol. 349, p. 221-232Article in journal (Refereed)
    Abstract [en]

    We derive perturbation bounds for the constrained and weighted linear least squares (LS) problems. Both the full rank and rank-deficient cases are considered. The analysis generalizes some results of earlier works.

  • 257.
    Gulliksson, Mårten
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Söderkvist, I.
    Watson, G.A.
    Implicit surface fitting using directional constraints2001In: Bit: numerical mathematics, ISSN 0006-3835, Vol. 41, no 2, p. 308-321Article in journal (Refereed)
    Abstract [en]

    A commonly used technique for fitting curves and surfaces to measured data is that known as orthogonal distance regression, where the sum of squares of orthogonal distances from the data points to the surface is minimized. An alternative has recently been proposed for curves and surfaces which are parametrically defined, which minimizes the sum of squares in given directions which depend on the measuring process. In addition to taking account of that process, it is claimed that this technique has the advantage of complying with traditional fixed-regressor assumptions, enabling standard inference theory to apply. Here we consider extending this idea to curves and surfaces where the only assumption made is that there is an implicit formulation. Numerical results are given to illustrate the algorithmic performance.

  • 258.
    Gulliksson, Mårten
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Wedin, Per-Åke
    Perturbation theory for generalized and constrained linear least squares2000In: Numerical Linear Algebra with Applications, ISSN 1070-5325, Vol. 7, no 4, p. 181-195Article in journal (Refereed)
    Abstract [en]

    The perturbation analysis of weighted and constrained rank-deficient linear least squares is difficult without the use of the augmented system of equations. In this paper a general form of the augmented system is used to get simple perturbation identities and perturbation bounds for the general linear least squares problem both for the full-rank and rank-deficient problem. Perturbation identities for the rank-deficient weighted and constrained case are found as a special case. Interesting perturbation bounds and condition numbers are derived that may be useful when considering the stability of a solution of the rank-deficient general least squares problem. Copyright © 2000 John Wiley & Sons, Ltd.

  • 259.
    Gulliksson, Mårten
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Wedin, P-Å
    The use and properties of Tikhonov filter matrices.2000In: SIAM Journal on Matrix Analysis and Applications, ISSN 0895-4798, Vol. 22, no 1, p. 276-281Article in journal (Refereed)
    Abstract [en]

    We consider the concept of Tikhonov filter matrices in connection with discrete ill-posed and rank-deficient linear problems. Important properties of the Tikhonov filter matrices are given together with their filtering and regularization effects. We also present new perturbation identities for the Tikhonov regularized linear least squares problem using filter matrices generalizing well-known perturbation identities for the linear least squares problem and pseudoinverses.

  • 260.
    Gulliksson, Mårten
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Wedin, P-Å
    Wei, Yimin
    Perturbation identities for regularized Tikhonov inverses and weighted pseudoinverses2000In: Bit: numerical mathematics, ISSN 0006-3835, Vol. 40, no 3, p. 513-523Article in journal (Refereed)
    Abstract [en]

    e consider the perturbation analysis of two important problems for solving ill-conditioned or rank-deficient linear least squares problems. The Tikhonov regularized problem is a linear least squares problem with a regularization term balancing the size of the residual against the size of the weighted solution. The weight matrix can be a non-square matrix (usually with fewer rows than columns). The minimum-norm problem is the minimization of the size of the weighted solutions given by the set of solutions to the, possibly rank-deficient, linear least squares problem. It is well known that the solution of the Tikhonov problem tends to the minimum-norm solution as the regularization parameter of the Tikhonov problem tends to zero. Using this fact and the generalized singular value decomposition enable us to make a perturbation analysis of the minimum-norm problem with perturbation results for the Tikhonov problem. From the analysis we attain perturbation identities for Tikhonov inverses and weighted pseudoinverses.

  • 261. Gustafsson, Bengt
    et al.
    Eriksson, Kjell
    Kiselman, Dan
    Olander, Nils
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Olofsson, Hans
    KI emission from envelopes around N-type stars: Spectroscopic observations and interpretations1997In: Astronomy and Astrophysics, ISSN 0004-6361, Vol. 318, no 2, p. 535-542Article in journal (Refereed)
    Abstract [en]

    Circumstellar envelopes around three bright N-type stars, R Scl, X TrA, and V Aql have been detected in emission in resonance lines from K I. This radiation, which is most probably scattered photospheric radiation, was first found spectroscopically, but has later been imaged with choronagraphic and polarimetric techniques. In the present paper, which is the first in a series, the spectroscopic K I observations are discussed. From the observations of the K I 769.9 nm emission we find systemic and expansion velocities in fair agreement with those obtained from the CO millimetre lines. We find a decline of the emission with distance from the star, in rough agreement with the assumption of a constant expansion velocity, mass-loss rate and K I abundance.Our mass loss estimates from the K I line observations agree rather well with those obtained from CO (rangning from 1/4 to 1/1 of the CO mass loss), which suggest that a considerable fraction of the potassium stays neutral through the envelope. This puts strong upper limits on the photoionizing chromospheric UV emission from the stars. Some indirect indications that the envelopes have inhomogeneous structures, clumps, are discussed.

  • 262.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    An Organizational Culture Perspective on the Role of Swedish Energy Utilities in Promoting Energy-Efficient End-Use Technologies1994In: Proceedings of the 1994 ACEEE Summer Study on Energy Efficiency in Buildings: Volume 1: Human Dimensions of Energy Consumption, 1994Conference paper (Other scientific)
  • 263.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Bioenergy in the environment - some examples of bioenergy applications in sweden1998In: Proceedings of Bioenergy in the environment - An update of global and New Zealand bioenergy initiatives, Rotorua, New Zealand, 10 March, 1998, 1998Conference paper (Other scientific)
  • 264.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Biomass and district heating systems1994In: Climate change, energy and the environment: World Renewable Energy Congress : 11-16 September 1994, Reading, UK, Oxford: Pergamon , 1994, p. 838-840Conference paper (Refereed)
    Abstract [en]

    New technologies for biomass gasification are being developed which increase the potential to cogenerate electricity and may reduce costs compared with steam turbine technology. Cogeneration is a more energy-efficient way to convert biomass into heat and electricity than separate electricity and heat production. The potential to cogenerate electricity in the Swedish district-heating systems is estimated to be 20% of current electricity production when using combined cycle technology. The electricity and heat costs from cogeneration with biomass are higher than the costs from fossil fuel plants at current fuel prices when external costs are excluded.

  • 265.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    CO2 Mitigation Costs1999In: Wood Energy News, Vol. 14, no 3, p. 18-19Article in journal (Other scientific)
  • 266.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    District Heating Systems and Energy Conservation: Part I1994In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 19, no 1, p. 81-91Article in journal (Refereed)
  • 267.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    District Heating Systems and Energy Conservation: Part II1994In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 19, no 1, p. 93-102Article in journal (Refereed)
  • 268.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    District Heating Systems and Local Energy Strategies1994Doctoral thesis, monograph (Other scientific)
  • 269.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Energy conservation in district-heated buildings1993In: The Energy Efficiency Challenge for Europe, The European Council for an Energy Efficient Economy, Oslo, Norway: proceedings of the 1993 ECEEE summer study, OSLO 1993, [Oslo]: European Council for an Energy-Efficient Economy , 1993Conference paper (Refereed)
  • 270.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Energy Efficiency and Competitiveness for Biomass-Based Energy Systems1997In: Energy-The International Journal, ISSN 0360-5442, Vol. 22, no 10, p. 959-967Article in journal (Refereed)
  • 271.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Klimatfördelar med att bygga i trä2007In: Bioenergi - till vad och hur mycket?, Stockholm, Sweden: Forskningsrådet för miljö, areella näringar och samhällsbyggande , 2007, p. 337-350Chapter in book (Other academic)
  • 272.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    On ecological engineering and sustainable development in a Swedish context2001In: Proceedings of the International Ecological Engineering Conference, Lincoln University, New Zealand, November 2001, 2001Conference paper (Other scientific)
  • 273.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Variability in carbon dioxide balance of wood- and concrete-framed buildings  2004In: 2nd World Biomass Conference, Rome, Italy 2004, 2004Conference paper (Refereed)
  • 274.
    Gustavsson, Leif
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Vi måste använda bioenergin effektivt2007In: Bioenergi - till vad och hur mycket?, Stockholm, Sweden: Forskningsrådet för miljö, areella näringar och samhällsbyggande , 2007, p. 103-120Chapter in book (Other academic)
  • 275.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Börjesson, Pål
    Biomass Utilisation and Transportation Demands1996In: Proceedings of the World Renewable Energy Congress - IV: Denver, Colorado, USA, June 1996, 1996Conference paper (Other scientific)
  • 276.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Börjesson, Pål
    CO2 Mitigation Cost: Bioenergy Systems and Natural Gas Systems with Decarbonization1998In: Energy Policy, ISSN 0301-4215, Vol. 26, no 9, p. 699-714Article in journal (Refereed)
  • 277.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Börjesson, Pål
    Power production and treatment of waste water with energy crops1997In: Proceedings of the International Conference on Technologies for Activities Implemented Jointly, Vancouver, Canada, 1997Conference paper (Other scientific)
  • 278.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Börjesson, Pål
    Johansson, B
    Svenningsson, P
    Reducing CO2 Emissions by Substituting Biomass for Fossil Fuels1995In: Energy, ISSN 0360-5442, Vol. 20, no 11, p. 1097-1113Article in journal (Refereed)
  • 279.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Holmberg, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Dornburg, Veronica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Sathre, Roger
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Eggers, Thies
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Mahapatra, Krushna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Marland, Gregg
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Using biomass for climate change mitigation and oil use reduction2007In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 35, no 11, p. 5671-5691Article in journal (Refereed)
    Abstract [en]

    In this paper, we examine how an increased use of biomass could efficiently meet Swedish energy policy goals of reducing carbon dioxide (CO2) emissions and oil use. In particular, we examine the trade-offs inherent when biomass use is intended to pursue multiple objectives. We set up four scenarios in which up to 400 PJ/year of additional biomass is prioritised to reduce CO2 emissions, reduce oil use, simultaneously reduce both CO2 emission and oil use, or to produce ethanol to replace gasoline. Technologies analysed for using the biomass include the production of electricity, heat, and transport fuels, and also as construction materials and other products. We find that optimising biomass use for a single objective (either CO2 emission reduction or oil use reduction) results in high fulfilment of that single objective (17.4 Tg C/year and 350 PJ oil/year, respectively), at a monetary cost of 130–330 million €/year, but with low fulfilment of the other objective. A careful selection of biomass uses for combined benefits results in reductions of 12.6 Tg C/year and 230 PJ oil/year (72% and 67%, respectively, of the reductions achieved in the scenarios with single objectives), with a monetary benefit of 45 million €/year. Prioritising for ethanol production gives the lowest CO2 emissions reduction, intermediate oil use reduction, and the highest monetary cost.

  • 280.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Joelsson, Anna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Biomass-fired energy systems for space heating. Extended abstract.2004In: World Bioenergy Conference & Exhibition on Biomass for Energy, Jönköping 2-4 June 2004, 2004Conference paper (Other scientific)
  • 281.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Joelsson, Anna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Energy conservation and conversion of electrical heating systems in detached houses2007In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 39, no 6, p. 717-726Article in journal (Refereed)
    Abstract [en]

    In this study, a Swedish house built in 1974, heated with resistance heaters was analysed. Different options for changing the heating system and electricity production were compared for this type of detached house, assuming coal-based electricity production as a reference. Changes in the fuel used, the electricity production technology, the end-use heating technology and the heat demand were analysed. The aim was to show how these different parts of the energy system interact and to evaluate the cost-effectiveness of reducing CO2 emission and primary energy use by different combinations of changes. The results showed that the CO2 emission and primary energy use could be reduced by 95 and 70%, respectively, without increased heating costs in a national economic perspective. The choice of end-use heating system had a greater influence than the energy conservation measures on the parameters studied. The energy conservation measures were less cost-effective in combination with the more energy-efficient heating systems, although the fact that they reduced the heat demand, and thus also the investment cost of the new heating system, was taken into account.

  • 282.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Joelsson, Anna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Uddin, Noim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Large scale biomass-based heating systems and energy conservation2004In: Biomass for energy, industry and climate protection : Second World Biomass Conference; proceedings of the world conference held in Rome, Italy, 10 - 14 May 2004; [held jointly with the 13th European Conference on Biomass for Energy, Industry and Climate Protection]: World Conference on Biomass for Energy, Industry and Climate Protection ; 2 (Rome) : 2004.05.10-14, Florens and Munich: ETA , 2004, p. 1978-1983Conference paper (Refereed)
  • 283.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Johansson, B
    Cogeneration: One Way to Use Biomass Efficiently1994In: Heat Recovery Systems & CHP, ISSN 0890-4332, Vol. 14, no 2, p. 117-127Article in journal (Refereed)
  • 284.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Johansson, B
    Identifying environmentally benign regional energy futures1993In: Proceedings of the Fourth International Conference on a System Analysis Approach, Tallinn, Estonia, 1993Conference paper (Other scientific)
  • 285.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Johansson, Bengt
    Bülow-Hübe, Helena
    An Environmentally Benign Energy Future for Western Scania, Sweden1992In: Energy, ISSN 0360-5442, Vol. 17, no 9, p. 809-822Article in journal (Refereed)
  • 286.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karjalainen, T
    Marland, G
    Savolainen, I
    Schlamadinger, B
    Apps, M
    Project-based Greenhouse Gas Accounting: guiding principles with a focus on baselines and additionality2000In: Energy Policy, ISSN 0301-4215, Vol. 28, no 13, p. 935-946Article in journal (Refereed)
  • 287.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karlsson, Å
    A System Perspective on the Heating of Detached Houses2002In: Energy Policy, ISSN 0301-4215, Vol. 30, no 7, p. 553-574Article in journal (Refereed)
  • 288.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karlsson, Å
    Biomass energy systems for single family houses - efficiency, emissions and costs1998In: Proceedings of the 10th European Conference and Technology Exhibition, Biomass for Energy and Industry, Würzburg, Germany, 1998Conference paper (Other scientific)
  • 289.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karlsson, Å
    CO2 mitigation cost: a system perspective on the heating of detached houses2000In: Woody biomass as an energy source : challenges in Europe : Joensuu, Finland 25-28 September 2000, Joensuu: EFI , 2000, p. 171-Conference paper (Refereed)
  • 290.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karlsson, Å
    District heating and bioenergy systems : efficiency and emissions1999In: Proceedings of the 7th International Symposium on District Heating and Cooling, [May 18-20,1999 at Lund, Sweden]: International Symposium on District Heating and Cooling (7th : 1999 : Lund, Lund, 1999Conference paper (Other scientific)
  • 291.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karlsson, Å
    Department of Technology and Society, Environmental and Energy Systems Studies, Lund University,.
    Heating Detached Houses in Urban Areas2003In: Energy, ISSN 0360-5442, Vol. 28, no 8, p. 851-875Article in journal (Refereed)
    Abstract [en]

    District heating systems using cogeneration, as well as local fuel-based and electric heating systems for detached houses, are analysed. The analysis includes the whole energy system, from the natural resource to the end user, with respect to primary energy use, emission and cost. The end-use technologies studied are heat pumps, resistance heaters and boilers. It was assumed that the base-load electricity, except for the cogenerated electricity, was produced in stand-alone power plants using wood chips or natural gas, while peak-load electricity and fuel used for transportation were produced from crude oil. The heat pump and district heating systems are found to be most energy efficient, followed by the local fuel-based systems. The wood-fuel-based systems emit about one tenth of the greenhouse gases emitted by the natural-gas-based systems. The sulphur and nitrogen oxide emission, however, is higher for wood-fuel-based systems. Systems based on natural gas are less expensive than the corresponding wood-fuel-based systems. Decarbonization and carbon dioxide sequestration, however, do not reduce the carbon dioxide emission to the low level of the wood-fuel-based systems and, in addition, make the natural-gas-based systems more expensive than the wood-fuel-based systems.

  • 292.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Karlsson, Åsa
    CO2 Mitigation: On Methods and Parameters for Comparison of Fossil-Fuel and Biofuel Systems2006In: Mitigation and Adaptation Strategies for Global Change, ISSN 1381-2386, E-ISSN 1573-1596, Vol. 11, no 5/6, p. 935-959Article in journal (Refereed)
    Abstract [en]

    The replacement of fossil fuels by biofuels could be an important means of reducing net carbon dioxide (CO2) emission. An estimation of the CO2 mitigation efficiency of biofuel systems depends on the method and assumptions used. Here, different parameters and methods are discussed for comparing fossil-fuel- and biofuel-based systems. Three parameters are suggested: the monetary cost, the primary energy cost and the biofuel cost of CO2 mitigation. They are defined as the difference in monetary expenditure, primary energy use and biofuel use between the compared systems, divided by the difference in net CO2 emission between the systems. Cogeneration and separate production of electricity and heat is then compared using these parameters and the methods of multi-functional products or subtraction. In both methods, either electricity or heat is regarded as the main product and the other is regarded as a by-product. The multi-functional method is preferable due to its transparency as both the main product and the by-product are part of the functional unit. Using heat as the main product illustrates the typical situation that the heat demand limits the use of cogeneration. When comparing systems the output from them should not differ. If the by-product is not fully, cogenerated part of the by-product has to be produced separately. A logical choice for producing this part of the by-product is to use a similar fuel and technology as used for cogeneration.

  • 293.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Madlener, R
    CEPE—Centre for Energy Policy and Economics, Swiss Federal Institute of Technology, ETH-Zentrum WEC, CH-8092, Zurich, Switzerland.
    CO2 Mitigation Costs of Large-scale Bioenergy Technologies in Competitive Electricity Markets2003In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 28, no 14, p. 1405-1425Article in journal (Refereed)
    Abstract [en]

    In this study, we compare and contrast the impact of recent technological developments in large biomass-fired and natural-gas-fired cogeneration and condensing plants in terms of CO2 mitigation costs and under the conditions of a competitive electricity market. The CO2 mitigation cost indicates the minimum economic incentive required (e.g. in the form of a carbon tax) to equal the cost of a less carbon extensive system with the cost of a reference system. The results show that CO2 mitigation costs are lower for biomass systems than for natural gas systems with decarbonization. However, in liberalized energy markets and given the socio-political will to implement carbon extensive energy systems, market-based policy measures are still required to make biomass and decarbonization options competitive and thus help them to penetrate the market. This cost of cogeneration plants, however, depends on the evaluation method used. If we account for the limitation of heat sinks by expanding the reference entity to include both heat and power, as is typically recommended in life-cycle analysis, then the biomass-based gasification combined cycle (BIG/CC) technology turns out to be less expensive and to exhibit lower CO2 mitigation costs than biomass-fired steam turbine plants. However, a heat credit granted to cogeneration systems that is based on avoided cost of separate heat production, puts the steam turbine technology despite its lower system efficiency at an advantage. In contrast, when a crediting method based on avoided electricity production in natural-gas-fired condensing plants is employed, the BIG/CC technology turns out to be more cost-competitive than the steam turbine technology for carbon tax levels beyond about $ 150/t C. Furthermore, steam turbine plants are able to compete with natural-gas-fired cogeneration plants at carbon tax levels higher than about $ 90/t C.

  • 294.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Madlener, R
    Liberalised electricity markets, new bioenergy technologies, and GHG emission reductions: interactions and CO2 mitigation costs1999In: Proceedings of 8th Forum Croatian Energy Day, Zagreb, 1999Conference paper (Other scientific)
  • 295.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Madlener, R.
    Centre for Energy Policy and Economics, Switzerland.
    Hoen, H.F.
    Agricultural University Norway.
    Jungmeier, G.
    Institute of Energy Research, Austria.
    Karjalainen, T.
    Finnish Forest Research Institute, Joensuu Research Centre, Finland.
    Klöhn, S.
    University of Technology Dresden, Germany.
    Mahapatra, Krushna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Pohjola, J.
    Finnish Forest Research Institute, Finland.
    Solberg, B.
    Agricultural University Norway.
    Spelter, H.
    Forest Products Laboratory, USDA Forest Service, United States.
    The role of wood material for greenhouse gas mitigation2006In: Mitigation and Adaptation Strategies for Global Change, ISSN 1381-2386, E-ISSN 1573-1596, Vol. 11, no 5-6, p. 1097-1127Article in journal (Refereed)
    Abstract [en]

    Based on an interdisciplinary perspective the role of wood as a carbon sink, as a multipurpose material, and as a renewable energy source for the net reduction of greenhouse gases is discussed. We synthesize aspects from engineering, natural and social sciences to better understand the role of wood substitution in CO2 mitigation.We also formulate some recommendations on filling knowledge gaps that could be useful for policy making regarding how wood substitution could be further expanded. There are sufficient wood resources to substantially increase the use of wood for material and energy purposes. However, a number of factors hinder a wider use of wood for energy and material purposes. Furthermore, an analysis of wood substitution is a very complex issue, since the substitution influencing factors are to be found along the entire wood supply chain and involve several industries, socio-economic and cultural aspects, traditions, price dynamics, and structural and technical change. To improve the knowledge about wood as a substitute for other resources and the implications, it would be helpful to better integrate research from different disciplines on the subject and to cover different scales from a project to an economy-wide level.

  • 296.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Madlener, Reinhard
    Mahapatra, Krushna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Framework conditions and market potentials for the diffusion of innovative small-scale wood pellet systems2003In: Bioenergy 2003, Proceedings: International Nordic Bioenergy Conference, 2-5 September, Jyväskylä, Finland, 2003Conference paper (Other scientific)
    Abstract [en]

    More than 85% of all dwellings in the European Union are currently being heated by single-house systems. At the same time significant technological progress, cost reductions and increasing consumer awareness related to modern small-scale bioenergy systems (SSBS) have occurred in recent years. Taken together, SSBS could make a substantial contribution to the heat and electricity requirements in the not-too-distant future and, by substituting for less benign energy technologies and fuels, also to a more sustainable energy supply system. Despite the remarkably increased levels of comfort and reduced environmental impact offered by today´s SSBS, however, their widespread diffusion is still at its very beginning. Framework and market conditions and the overall merits of SSBS systems need to be properly understood by policy-makers for a suc-cessful promotion policy addressing these technologies. Technology diffusion models can help to better understand the diffusion dynamics and long-term market potentials, and the effectiveness of drivers and barriers that influence the adoption decision process. This paper first summarises recent technological, socio-economic and institutional trends relevant for SSBS adoption, and reflects on research results from other studies in this field regarding perceived image, comfort levels, reliability, and ways of use of modern small-scale bioenergy technologies in Europe. Second, it contains a limited compara-tive analysis of the direct and indirect external costs and benefits of modern bioenergy-based versus other heating technolo-gies at the small scale. Third, the usefulness of various economic diffusion modelling approaches is discussed, also with a perspective on studying modern SSBS in the light of data availability restrictions

  • 297.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Mahapatra, Krushna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Swedish house owners perception of pellet heating systems2006In: Proceedings of the Second World Conference on Pellets (Pellets 2006), 30 May-1 June, Jönköping, Sweden, Swedish Bioenergy Association , 2006Conference paper (Other academic)
    Abstract [en]

    In response to the problems of global warming and security issues associated with the supply of fossil fuel use, bioenergy systems such as small-scale pellet heating systems (SSPHS) have been developed in Europe and elsewhere. In Sweden, SSPHS for the residential sector have been available on the market for about ten years, but the diffusion rate is rather slow. Research to analyse the diffusion of innovation is important, as this aspect determines the success of a technology. In this context, we recently carried out a questionnaire survey on Swedish house owners� perception of different heating systems. The sample consisted of about 1500 Swedish house owners selected through stratified random sampling. The results of the survey regarding pellet heating systems revealed that the annual cost of heating with the new heating system, functional reliability, investment cost, and in-door air quality are the four most important factors, in decreasing order of importance, in heating system choice. Environmental friendliness and low greenhouse gas emission are considered to be less important. Respondents consider SSPHS to be second to bedrock heat pumps in every aspect except for investment cost and therefore, such systems diffuse slowly in Sweden.

  • 298.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Mahapatra, Krushna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Madlener, R
    Energy systems in transition: perspectives for the diffusion of small-scale wood pellet heating technology2005In: International Journal of Technology Management, ISSN 0267-5730, E-ISSN 1741-5276, Vol. 29, no 3/4, p. 327-347Article in journal (Refereed)
    Abstract [en]

    In response to environmental and supply security concerns associated with fossil fuels, promising small-scale wood heating systems with sizable market potentials have started to penetrate the residential heating market in Europe and elsewhere. Despite significant technological progress that led to cost reduction, increased levels of convenience, improved reliability and reduced environmental impact, the widespread diffusion of such systems will nonetheless take many years or even decades. Framework and market conditions, and especially drivers and barriers and the overall merits of such systems in comparison to alternative solutions, need to be properly understood by policy-makers and entrepreneurs for the successful promotion of these technologies. In this article we cover three important aspects related to small-scale wood pellet heating systems. First, we summarise recent technological, socio-economic and institutional trends. Second, results from a comparative analysis of the direct and indirect external costs and benefits of these technologies versus other heating technologies are reported. Third, the usefulness of various diffusion modelling approaches used in economics is discussed in the light of the technology scrutinised and existing data constraints.

  • 299.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Näslund, Lisa
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Cost of collection, processing and transportation of forest residues and CO2 benefits of fossil fuel replacementManuscript (Other academic)
  • 300.
    Gustavsson, Leif
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Pingoud, Kim
    Finnish Forest Research Institute, Finland.
    Sathre, Roger
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Carbon dioxide balance of wood substitution: comparing concrete- and wood-framed buildings2006In: Mitigation and Adaptation Strategies for Global Change, ISSN 1381-2386, E-ISSN 1573-1596, Vol. 11, no 3, p. 667-691Article in journal (Refereed)
    Abstract [en]

    In this study a method is suggested to compare the net carbon dioxide (CO2) emission from the construction of concrete- and wood-framed buildings. The method is then applied to two buildings in Sweden and Finland constructed with wood frames, compared with functionally equivalent buildings constructed with concrete frames. Carbon accounting includes: emissions due to fossil fuel use in the production of building materials; the replacement of fossil fuels by biomass residues from logging, wood processing, construction and demolition; carbon stock changes in forests and buildings; and cement process reactions. The results show that wood-framed construction requires less energy, and emits less CO2 to the atmosphere, than concrete-framed construction. The lifecycle emission difference between the wood- and concrete-framed buildings ranges from 30 to 130 kg C per m2 of floor area. Hence, a net reduction of CO2 emission can be obtained by increasing the proportion of wood-based building materials, relative to concrete materials. The benefits would be greatest if the biomass residues resulting from the production of the wood building materials were fully used in energy supply systems. The carbon mitigation efficiency, expressed in terms of biomass used per unit of reduced carbon emission, is considerably better if the wood is used to replace concrete building material than if the wood is used directly as biofuel.

3456789 251 - 300 of 768
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf