Change search
Refine search result
2452245324542455245624572458 122701 - 122750 of 123549
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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.
  • 122701.
    Ånmark, Niclas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy. Swerea KIMAB, Sweden.
    Karasev, Andrey
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Jönsson, Pär Göran
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    The Effect of Different Non-Metallic Inclusions on the Machinability of Steel2015In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 8, no 2, p. 751-783Article in journal (Refereed)
    Abstract [en]

    Considerable research has been conducted over recent decades on the role of non-metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, etc.) are discussed and summarized. Finally, some methods for modification of non-metallic inclusions in the liquid steel are considered to obtain a desired balance between mechanical properties and machinability of various steel grades.

  • 122702.
    Ånmark, Niclas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Lovquist, Simon
    Vosough, Manouchehr
    Bjork, Thomas
    The Effect of Cleanliness and Micro Hardness on the Machinability of Carburizing Steel Grades Suitable for Automotive Applications2016In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 87, no 4, p. 403-412Article in journal (Refereed)
    Abstract [en]

    This work reports on soft part turning of carburizing steels using cemented carbide (CC) cutting tools. The emphasis is on the influence of the cleanliness and micro hardness on the machinability of carburizing steel grades. A reference steel grade is included in this study together with a clean steel and an ultra-clean steel. Machining tests are conducted to examine the cutting tool life, the balance between the excessive flank or crater wear and the chip formation. The wear mechanisms are examined by using a scanning electron microscope (SEM) equipped with a back-scatter (BS) detector. It is possible to differentiate between the machinability of the clean steel grades, having only a minor difference in the sulfur and oxygen contents. Furthermore, the longest tool life is obtained when machining the reference steel. The superior machinability of the reference steel R is linked to its high content of sulfur. It is believed that MnS inclusions act as stress raisers in the primary shear zone. Hence, this will improve the chip formation process.

  • 122703.
    Åqvist, Anders
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Söderberg, Charlie
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Juniorfinansiering av fastighetsinvesteringarEn studie av kapitalmarknaden för hög belåning avfastighetsinvesteringar i Sverige2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis addresses small and medium sized real estate companies’ debt financing options,

    to leverage ratios higher than the ratios traditional banks are willing to finance real estate

    investments to. The thesis aims to identify the financing options available in the Swedish

    capital market, for small and medium sized real estate companies, and discuss how the

    financing options can be developed.

    The study has a qualitative approach. The identification of the funding options is based partly

    on secondary sources, and partly on information obtained in interviews, with people involved

    in real estate financing, real estate owning or within academia.

    Alternative forms of financing, suitable for this group of companies, are primarily mezzanine

    financing and financing by bonds. Mezzanine financing is debt with lower priority than

    normal, preferred bank loans. Bond financing is obtained at the capital markets through debt

    raised from participants on the market. Loans from the previous owner, earnouts, bank loans

    with a high rate of amortization and capital from co-investors are other forms of alternative

    funding sources that exist in the market. Many companies can successfully use those forms of

    funding in certain situations.

    Demand for alternative funding is high. The study argues that mezzanine financing is the form

    that works best, of the alternative forms of financing in the capital market. The market for

    mezzanine financing is expected to develop further, and there is room for more players in the

    market. Also, the bond market has potential to develop further, with for example market

    places directed at private individual investors. Financing alternatives outside the traditional

    capital markets can work very well for certain types of businesses and investments.

  • 122704. Århammar, C.
    et al.
    Endrino, J. L.
    Ramzan, M.
    Horwat, D.
    Blomqvist, Andreas
    Rubensson, J. -E
    Andersson, J.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Probing temperature-induced ordering in supersaturated Ti-1 (-) xAlxN coatings by electronic structure2014In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 242, p. 207-213Article in journal (Refereed)
    Abstract [en]

    The ordering of supersaturated cubic titanium aluminum nitride (c-Ti0.35Al0.65N) coatings is probed from room temperature up to and above the point of spinodal decomposition, using Near Edge X-ray Absorption Fine-structure (NEXAFS) and first principles calculations. The measured and calculated nitrogen (N) K spectra suggest that unoccupied N p states hybridize with Ti d states. When temperature is raised the N p-Ti d overlap decreases, whereas hybridization between N p and Al p tends to increase. The observed spectral changes with temperature together with calculations of defect heat of formation suggest a depletion of N in the surroundings of Ti in c-Ai(1) (-) xAlxN and/or in the formed c-TiN.

  • 122705.
    Århammar, Cecilia
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Atomistic modelling of functional solid oxides for industrial applications: Density Functional Theory, hybrid functional and GW-based studies2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this Thesis a set of functional solid oxides for industrial applications have been addressed by first principles and thermodynamical modelling. More specificially, measurable quantities such as Gibbs free energy, geometry and electronic structure have been calculated and compared when possible with experimental data. These are crystalline and amorphous aluminum oxide (Al2O3), Zirconia (ZrO2), magnesium oxide (MgO), indiumoxide (In2O3) and Kaolinite clay (Al2Si2O5(OH)4).

    The reader is provided a computation tool box, which contains a set of methods to calculate properties of oxides that are measurable in an experiment. There are three goals which we would like to reach when trying to calculate experimental quantities. The first is verification. Without verification of the theory we are utilizing, we cannot reach the second goal -prediction. Ultimately, this may be (and to some extent already is) the future of first principles methods, since their basis lies within the fundamental quantum mechanics and since they require no experimental input apart from what is known from the periodic table. Examples of the techniques which may provide verification are X-Ray Diffraction (XRD), X-ray Absorption and Emission Spectroscopy (XAS and XES), Electron Energy Loss Spectroscopy and Photo-Emission Spectroscopy (PES). These techniques involve a number of complex phenomena which puts high demands on the chosen computational method/s. Together, theory and experiment may enhance the understanding of materials properties compared to the standalone methods. This is the final goal which we are trying to reach -understanding. When used correctly, first principles theory may play the role of a highly resolved analysis method, which provides details of structural and electronic properties on an atomiclevel. One example is the use of first principles to resolve spectra of multicomponentsamples. Another is the analysis of low concentrations of defects. Thorough analysis of the nanoscale properties of products might not be possible in industry due to time and cost limitations. This leads to limited control of for example low concentrations of defects, which may still impact the final performance of the product. On example within cutting tool industry is the impact of defect contents on the melting point and stability of protective coatings. Such defects could be hardening elements such as Si, Mn, S, Ca which diffuse from a steel workpiece into the protective coating during high temperature machining. Other problems are the solving of Fe from the workpiece into the coating and reactions between iron oxide, formed as the workpiece surface is oxidized, and the protective coating.

    The second part of the computational toolbox which is provided to the reader is the simulation of solid oxide synthesis. Here, a formation energy formalism, most often applied to materials intended in electronics devices is applied. The simulation of Chemical Vapour Deposition (CVD) and Physical Vapor Deposition (PVD) requires good knowledge of the experimental conditions, which can then be applied in the theoretical simulations. Effects of temperature, chemical and electron potential, modelled concentration and choice of theoretical method on the heat of formation of different solid oxides with and without dopants are addressed in this work. A considerable part of this Thesis is based upon first principles calculations, more specifically, Density Functional Theory (DFT) After Kohn and Pople received the Nobel Prize in chemistry in 1998, the use of DFT for computational modelling has increased strikingly (see Fig. 1). The use of other first principles methods such as hybrid functionals and the GW approach (see abbreviations for short explanations and chapter 4.5 and 5.3.) have also become increasingly popular, due to the improved computational resources. These methods are also employed in this Thesis.

  • 122706.
    Århammar, Cecilia
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Study of solid oxide systems from first principles calculations: energetics and magnetic properties of native defects and dopants in ZrO2 and MgO2009Licentiate thesis, comprehensive summary (Other academic)
  • 122707.
    Århammar, Cecilia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Araujo, C. Moyses
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Rao, K. Venkat
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Norgren, S.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Energetics and magnetic properties of V-doped MgO bulk and (001) surface: A GGA, GGA+U, and hybrid density functional study2010In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 82, no 13, p. 134406-Article in journal (Refereed)
    Abstract [en]

    In this work, a first-principles study of the energetic and magnetic properties of V-doped MgO is presented, where both the bulk and (001) surface were investigated. It is found that V assumes a high-spin state with a local moment of about 3 mu(B). In the bulk, the interaction between these local moments is very short ranged and the antiferromagnetic (AFM) ordering is energetically more favorable. The formation of V-V-Mg-V defect clusters is found to weaken the antiferromagnetic coupling in bulk MgO, degenerating the AFM and ferro-magnetic state. However, these clusters are high in energy and will not form at equilibrium conditions. By employing the GGA+U approach, with U=5 eV, the V 3d states on the (001) surface are shifted below the Fermi level, and a reasonable surface geometry was achieved. A calculation with the hybrid HSE03 functional, contradicts the GGA+U results, indicating that the V-MgO surface should be metallic at this concentration. From the energetics it is concluded that, at the modeled concentration, VxOy phases will limit the solubility of V in MgO at equilibrium conditions, which is in agreement with previous experimental findings. In order to achieve higher concentrations of V, an off-equilibrium synthesis method is needed. Finally, we find that the formation energy of V at the surface is considerably higher than in the bulk and V is thus expected to diffuse from the surface into the bulk of MgO.

  • 122708.
    Århammar, Cecilia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Moysés Araújo, C.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Energetics of Al doping and intrinsic defects in monoclinic and cubic zirconia: First-principles calculations2009In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 80, no 11, p. 115208-Article in journal (Refereed)
    Abstract [en]

    First-principles theory within the supercell approach has been employed to investigate Al doping and intrinsic defects in monoclinic and cubic zirconia. The effect of oxygen chemical potential and Fermi level on the formation energy and on the defect concentration have been taken into account. The formation of oxygen vacancies is found to be energetically more favorable in the cubic than in the monoclinic phase under the same oxygen chemical potential and Fermi energy. In both phases, substitutional Al decays from neutral charge state into the charge state -1, with the transition energy just above to the top of the valence band. Our findings indicate that by confining the Fermi energy to the region between the middle of the band gap and the bottom of the conduction band, high Al solubility could be achieved, although formation of Al is likely followed by the formation of interstitial oxygen. Furthermore, the concentration of Al with charge state -1 along with the equilibrium Fermi energy have been calculated in a self-consistent procedure. Here, the possible compensating defects with the relevant charge states have been considered. The obtained concentrations of Al and oxygen vacancies follow the experimental trend but underestimates experimental data. When the formation of defect clusters, composed by two substitutional Al and one oxygen vacancy, are considered, good quantitative agreement with experimental values of both Al and oxygen vacancy concentration is achieved. The results suggest that defect clusters will be formed as a result of Al doping in cubic phase of ZrO2, whereas the concentration of defect clusters is negligible in the monoclinic phase, both in accordance with experiment.

  • 122709.
    Århammar, Cecilia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Moysés Araújo, C.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Structure and electronic properties of Al-doped zirconia polymorphs from first principlesManuscript (Other academic)
  • 122710.
    Århammar, Cecilia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Moysés Araújo, C.
    Rao, K Venkat.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    First-principles investigation of magnetic properties of V-doped MgO: bulk and (001) surfaceManuscript (Other academic)
  • 122711.
    Århammar, Cecilia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Pietzsch, Annette
    Bock, Nicolas
    Holmstroem, Erik
    Araujo, C. Moyses
    Grasjo, Johan
    Zhao, Shuxi
    Green, Sara
    Peery, T.
    Hennies, Franz
    Amerioun, Shahrad
    Foehlisch, Alexander
    Schlappa, Justine
    Schmitt, Thorsten
    Strocov, Vladimir N.
    Niklasson, Gunnar A.
    Wallace, Duane C.
    Rubensson, Jan-Erik
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Unveiling the complex electronic structure of amorphous metal oxides2011In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 108, no 16, p. 6355-6360Article in journal (Refereed)
    Abstract [en]

    Amorphous materials represent a large and important emerging area of material's science. Amorphous oxides are key technological oxides in applications such as a gate dielectric in Complementary metal-oxide semiconductor devices and in Silicon-Oxide-Nitride-Oxide-Silicon and TANOS (TaN-Al2O3-Si3N4-SiO2-Silicon) flash memories. These technologies are required for the high packing density of today's integrated circuits. Therefore the investigation of defect states in these structures is crucial. In this work we present X-ray synchrotron measurements, with an energy resolution which is about 5-10 times higher than is attainable with standard spectrometers, of amorphous alumina. We demonstrate that our experimental results are in agreement with calculated spectra of amorphous alumina which we have generated by stochastic quenching. This first principles method, which we have recently developed, is found to be superior to molecular dynamics in simulating the rapid gas to solid transition that takes place as this material is deposited for thin film applications. We detect and analyze in detail states in the band gap that originate from oxygen pairs. Similar states were previously found in amorphous alumina by other spectroscopic methods and were assigned to oxygen vacancies claimed to act mutually as electron and hole traps. The oxygen pairs which we probe in this work act as hole traps only and will influence the information retention in electronic devices. In amorphous silica oxygen pairs have already been found, thus they may be a feature which is characteristic also of other amorphous metal oxides.

  • 122712.
    Århammar, Cecilia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Silvearv, F.
    Norgren, Susanne
    Pedersen, Henrik
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    A theoretical study of point defects incorporated into CVD-grown α-aluminaManuscript (preprint) (Other academic)
    Abstract [en]

    The energetics and electronic structure of a number of defects; C, Cl, H and S in alpha-Al2O3 is investigated. These species are present in the gas phase during the Chemical Vapor Deposition (CVD) and little is known of their solubility in alpha-Al2O3. It is found that not only the hydrogen interstitial, which is already wellknown for its dual action as a donor and acceptor defect will be amphotheric, but also the carbon and sulfur interstitial may gain both negative and positive charge states. However, at the CVD equilibrium conditions, charge compensation between the different defects will most likely not take place. For this a non equilibrium method such as Plasma Enhanced CVD or Physical Vapor Deposition (PVD) is needed.

  • 122713. Århem, P.
    et al.
    Klement, G.
    Blomberg, Clas
    KTH, School of Engineering Sciences (SCI), Theoretical Physics, Theoretical Biological Physics.
    Channel density regulation of firing patterns in a cortical neuron model2006In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 90, no 12, p. 4392-4404Article in journal (Refereed)
    Abstract [en]

    Modifying the density and distribution of ion channels in a neuron (by natural up- and downregulation or by pharmacological intervention or by spontaneous mutations) changes its activity pattern. In this investigation we analyzed how the impulse patterns are regulated by the density of voltage-gated channels in a neuron model based on voltage-clamp measurements of hippocampal interneurons. At least three distinct oscillatory patterns, associated with three distinct regions in the Na-K channel density plane, were found. A stability analysis showed that the different regions are characterized by saddle-node, double-orbit, and Hopf-bifurcation threshold dynamics, respectively. Single, strongly graded action potentials occur in an area outside the oscillatory regions, but less graded action potentials occur together with repetitive. ring over a considerable range of channel densities. The relationship found here between channel densities and oscillatory behavior may partly explain the difference between the principal spiking patterns previously described for crab axons (class 1 and 2) and cortical neurons ( regular. ring and fast spiking).

  • 122714. Århem, Peter
    et al.
    Blomberg, Clas
    KTH, School of Engineering Sciences (SCI), Theoretical Physics, Theoretical Biological Physics.
    Ion channel density and threshold dynamics of repetitive firing in a cortical neuron model2007In: Biosystems (Amsterdam. Print), ISSN 0303-2647, E-ISSN 1872-8324, Vol. 89, no 1-3, p. 117-125Article in journal (Refereed)
    Abstract [en]

    Modifying the density and distribution of ion channels in a neuron (by natural up- and down-regulation, by pharmacological intervention or by spontaneous mutations) changes its activity pattern. In the present investigation, we analyze how the impulse patterns are regulated by the density of voltage-gated channels in a model neuron, based on voltage clamp measurements of hippocampal interneurons. At least three distinct oscillatory patterns, associated with three distinct regions in the Na-K channel density plane, were found. A stability analysis showed that the different regions are characterized by saddle-node, double-orbit, and Hopf bifurcation threshold dynamics, respectively. Single strongly graded action potentials occur in an area outside the oscillatory regions, but less graded action potentials occur together with repetitive firing over a considerable range of channel densities. The presently found relationship between channel densities and oscillatory behavior may be relevance for understanding principal spiking patterns of cortical neurons (regular firing and fast spiking). It may also be of relevance for understanding the action of pharmacological compounds on brain oscillatory activity.

  • 122715.
    Årman, Louise
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Lösningsmedel på Becker Industrial Coatings AB, en kartläggning av lösningsmedelsutsläpp på Sätunafabriken, Märsta2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis has been realized in cooperation with Becker Industrial Coatings AB and has been conducted at the Sätuna factory in Märsta. The aim was to investigate the solvent emissions from the plant in order to reach a higher understanding for the emission situation today. After a first inventory of the process the step that contributes the most to solvent release has been object to further investigation and the questions that have been answered are;

    • Is it possible to understand the emission situation better by investigating the process step that contributes the most to release of solvents to the environment?
    • Which operation in this process step contributes the most to release of solvents to the environment and the production premises?
    • Is it possible to reduce these emissions without significant processes adjustments?

    At the Sätuna facility paint products for coil coatings and special coatings are manufactured for use at an industrial level and in the year 2007 23 600 tones of these products were produced. The operations are classified as environmental hazardous and from the beginning of 2011 the company are not allowed to emit more than 35 tones of volatile organic solvents each year to the air. Acetone, xylene, and butyl acetate were the solvents which was most represented in the total emissions to air in 2007.

    Paint products mainly consist of four components; base resins, solvents, pigments and additives. During the production of these products a numerous of unit operations are involved including premixing, dispersion, let down, and tinting. During the process contamination of production cisterns take place and cleaning of these are carried out in dishwashers with acetone as a washing agent.

    Manufacturing of paint products involves handling numerous of solvents. Three chemical groups that are excellent solvers are aromatic hydrocarbons, ketones, and esters. The use of solvents can contribute to both environmental impact as well as impact on the human health. The major environmental issues are the formation of ground level ozone and the contributions to the global worming. The health issues are irritated respiratory system, dry skin, and headache. The symptoms can be transverse or more permanent. During the past years BIC AB has removed solvents from their production line which has been exceptionally harmful for the human health and the environment.

    After reviewing the process the result shows clearly that it was the washing procedure that contributes the most to emissions of solvents. Measurements have been conducting in this process in order to determent if the emissions could be lowered by increasing the ventilation time. Metering has also been made on cisterns in the production in order to determent how much acetone that is emitted in other unit operations.

    The results from the experiment show that it is impossible to lower the emissions from the washing procedure by increasing the ventilation time. It was however seen that the single most contributing action is when the cistern is taken out from the machine. The results from the measurements also show that it is difficult to reduce the emissions without significant process adjustments. The metering that was conducted on cisterns was showing very small amounts of acetone or no acetone at all which makes it difficult to interpret the results. For future improvements the company should continue to work with alternative solutions for cleaning of their production cisterns. One solution could be to investigate if the cisterns must be cleaned after every batch. Other solutions could be to remove the automatic door opening on the dishwashers and also move the tubs filled with acetone that are placed outside the dishwasher.

  • 122716. Årzen, Karl-Erik
    et al.
    Johansson, Mikael
    Fuzzy control: from heuristic PID to optimization-based nonlinear control1999In: Fuzzy logic control: advances and applications / [ed] Verbruggen, Henk; Babuska, Robert, World Scientific Publishing , 1999Chapter in book (Other academic)
  • 122717. Årzen, Karl-Erik
    et al.
    Johansson, Mikael
    Babuska, Robert
    Fuzzy Control versus Conventional Control1999In: Fuzzy algorithms for control / [ed] Verbruggen, Henk, Kluwer academic publishers , 1999Chapter in book (Other academic)
  • 122718. Årzén, Karl-Erik
    et al.
    Bicchi, Antonio
    Dini, Gianluca
    Hailes, Stephen
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Lygeros, John
    Tzes, Anthony
    A component-based approach to the design of networked control systems2007In: European Journal of Control, ISSN 0947-3580, E-ISSN 1435-5671, Vol. 13, no 2-3, p. 261-279Article in journal (Refereed)
    Abstract [en]

    Component-based techniques revolve around composable, reusable software objects that shield the application level software from the details of the hardware and low-level software implementation and vice versa. Components provide many benefits that have led to their wide adoption it software and middleware developed for embedded systems: They are well-defined entities that can be replaced without affecting the rest of the systems, they can be developed and tested separately and integrated later, and they are reusable. Clearly such features are important for the design of large-scale complex systems more generally, beyond software architectures. We propose the use of a component approach to address embedded control problems. We outline a general coponent-based framework to embedded control aid show how it can be instantiated inspecific problems that arise in the control over/of sensor networks. Building on the middleware component framework developed under the European project RUNES, we develop a number of control-oriented components necessary for the implementation of control applications and design their integration. The paper provides the overview of the approach, discusses a real life application where the approach has been tested and outlines a number of specific control problems that arise in this application.

  • 122719. Årzén, Karl-Erik
    et al.
    Bicchi, Antonio
    Hailes, Stephen
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Lygeros, John
    On the design and control of wireless networked embedded systems2006In: 2006 IEEE Conference on Computer-Aided Control System Design, Vols 1 and 2, IEEE , 2006, p. 143-148Conference paper (Refereed)
    Abstract [en]

    Wireless networked embedded systems are becoming increasingly important in a wide area of technical fields. In this tutorial paper we present recent results on the design of these systems and their use in control applications, that have been developed within the project Reconfigurable Ubiquitous Networked Embedded Systems (RUNES). RUNES is a European Integrated Project with the aim to control complexity in networked embedded systems by developing robust and scalable middleware systems. New components for control under varying network conditions are discussed for the RUNES architecture. The paper highlights how the complexity of the closed-loop system is increased, due to additional disturbances introduced by the communication system: additional delays, jitter, data rate limitations, packet losses, etc. Experimental work on integration test beds that demonstrates these results is presented, together with motivating links to the RUNES disaster relief tunnel scenario.

  • 122720. Årzén, Karl-Erik
    et al.
    Robertsson, Anders
    Henriksson, Dan
    Johansson, Mikael
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Automatic Control.
    Conclusions from the European Roadmap on Control of Computing Systems2006In: First International Workshop on Feedback Control Implementation and Design in Computing Systems and Networks, 2006Conference paper (Refereed)
  • 122721. Årzén, Karl-Erik
    et al.
    Robertsson, Anders
    Henriksson, Dan
    Johansson, Mikael
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Conclusions of the ARTIST2 roadmap on control of computing systems2006In: ACM SIGBED Review, ISSN 1551-3688, Vol. 3, no 2, p. 11-20Article in journal (Refereed)
  • 122722.
    Åsa, Wallström
    et al.
    Division of Industrial Marketing, e-Commerce and Logistics, Luleå University of Technology.
    Karlsson, Ted
    Division of Industrial Marketing, e-Commerce and Logistics, Luleå University of Technology.
    Salehi-Sangari, Esmail
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Building a corporate brand: The internal brand building process in Swedish service firms2008In: Journal of Brand Management, ISSN 1350-231X, E-ISSN 1479-1803, Vol. 16, no 1-2, p. 40-50Article in journal (Refereed)
    Abstract [en]

    There is consensus that every organisation needs to develop a strong brand as part of its business strategy. It is, however, unclear how corporate brands can be effectively developed. The aim of this study is to empirically explore the internal corporate brand-building process in Swedish service firms. This process refers to activities that occur before the implementation of the brand. This is a qualitative study in which three case studies are presented and in which purposive sampling was applied. The study ’ s aim was to find illustrative cases of firms that had recently conducted an internal, corporate brand-building process. The selected firms had initiated the process based on different circumstances (ie due to a crisis, geographical expansion or strategic repositioning). Personal interviews were used as the main data collection method. Three concurrent flows of activities, that is, data reduction, data display and conclusion drawing, have been applied in the data analysis. All firms aimed to strengthen the corporate brand in their brand portfolio by

    reducing sub-brands, and by updating their brand identity and brand position statements. Findings show that even though the three firms had initiated the internal corporate brand-building process for different reasons, the three stages in the process, that is, brand audit, brand identity and brand position statements, could still be identified. Differences, however, occurred within the stages.

  • 122723.
    Åsberg, Cecilia
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Feminist posthumanities2018In: Posthuman Glossary / [ed] Rosi Braidotti and Maria Hlavajova, London: Bloomsbury Academic, 2018, 1, p. 157-160Chapter in book (Refereed)
    Abstract [en]

    In art, science, and the humanities we are now experiencing a "posthuman condition". Under the pressure of new dvelopments - such as neoliberal economics of global capitalism, migration, technological advances, environmental destruction on a mass scale, the perpetual war on terror and extensive security systems - the concept of the human as we had previously known it has undergone dramatic transformations. So has the humanities. This chapter explores feminist posthumanities, and its more-than-human focus on technoscience, environment and multispecies relationships. 

  • 122724.
    Åsberg, Cecilia
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Feminist Posthumanities in the Anthropocene: Forays into the Postnatural2018In: Journal of Posthuman Studies: Philosophy, Technology, Media, ISSN 2472-4513, Vol. 1, no 2, p. 185-204Article in journal (Refereed)
    Abstract [en]

    In the new planetary age of the Anthropocene or the Age of Man (as it were),humanity is cast as a single geological force, a major force of environmentaldestruction, and one folding in on itself. The Anthropocene is famously definedby human-induced climatic, biological, and geological transformations of ourplanet, by a profound anthropogenic environmental impact and mass speciesextinctions. However, the Anthropocene risk also, as pointed out by a widerange of feminist philosophers and critical scholars, hides troublesome differencesbetween humans, and also hides intimate relationships between technology,humans, and other animals. This totalization of humanity is a parallel risk insome posthuman theorizing also, and something postdisciplinary scholars ofthe critical humanities and feminist philosophers have paid attention to fordecades. In the posthuman context of the Anthropocene, I suggest and pointto postdisciplinary humanities research and theory–practices that pay carefulattention to the feminist theoretical work on our equally postnatural conditionas an experimental remedy.

  • 122725.
    Åsberg, Cecilia
    KTH, School of Architecture and the Built Environment (ABE).
    The Posthumanities Hub: Feminist Posthumanities for a More-than-Human World2018In: In & Beyond Sweden: Journeys through an Art scene / [ed] Joa Ljungberg, Lena Malm, Johan Pousette, Santiago Mostyn, Stockholm: Idea Books , 2018Chapter in book (Refereed)
    Abstract [en]

    In lieu of an abstract, this chapter introduces key features of the emerging field of feminist posthumanities at the intersections of art and science,

  • 122726. Åsberg, Cecilia
    et al.
    Braidotti, Rosi
    Utrecht Universitet, Nederländerna.
    A Feminist Companion to the Posthumanities2018Book (Refereed)
    Abstract [en]

    This companion is a cutting-edge primer to critical forms of the posthumanities and the feminist posthumanities, aimed at students and researchers who want to catch up with the recent theoretical developments in various fields in the humanities, such as new media studies, gender studies, cultural studies, science and technology studies, human animal studies, postcolonial critique, philosophy and environmental humanities. It contains a collection of nineteen new and original short chapters introducing influential concepts, ideas and approaches that have shaped and developed new materialism, inhuman theory, critical posthumanism, feminist materialism, and posthuman philosophy. A resource for students and teachers, this comprehensive volume brings together established international scholars and emerging theorists, for timely and astute definitions of a moving target – posthuman humanities and feminist posthumanities.

  • 122727. Åsberg, Cecilia
    et al.
    Cielemecka, Olga
    Toxic Embodiment and Feminist Environmental Humanities2019In: Environmental humanities, ISSN 2201-1919, E-ISSN 2201-1919, Vol. 11, no 1Article in journal (Refereed)
  • 122728.
    Åsberg, Cecilia
    et al.
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Radomska, Marietta
    Linköping University.
    Doing Away with Life: On Biophilosophy, and Reimagining Ethics: On Biophilosophy, and Reimagining Ethics 2019In: Life as we Don’t Know It: 10th Anniversary Volume of the Bioart Society in Finland. / [ed] Berger, E., Mäki-Reinikka, K., O'Reilly, K. & Sederholm, H., Helsinki: Aalto ARTS Books , 2019, p. 8-Chapter in book (Refereed)
  • 122729.
    Åsberg, Christer
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Entrepreneurship and innovation.
    External Innovation through Acquisitions in the High-tech Industry.: A Study of Strategic Implications2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Mergers and acquisition (M&A) have been at the forefront of academic research. However, most  of  the  research  in  this  realm  focuses  on  the  generic  benefits  that  arise  from acquisitions  or  the  challenges  that  they  involve.  This  paper  highlights  the  use  of acquisitions in the high-tech intensive industries (examples include pharmaceuticals, and electronic and communications) as a favorable means of external innovation to maintain competitive advantage.  The main objective of this research is to analyze both primary and secondary data,  in  order  to  propose  the  circumstances  under  which  it  is  strategically advantageous for firms to engage in external innovation through acquisition. The primary data has been collected from interviews with Oracle Corporation, and a current start-up in the high-tech industry. The following conclusion is drawn, that large profitable firms with accumulated and current R&D efforts, can benefit from acquiring smaller private start-ups to remain competitive. The uncertainty in technologically driven environment demands adaptable  firm boundaries to  continuously improve core  competencies, introduce new products lines, and decrease the time to market. The paper highlights the necessity for external innovation because in-house R&D is insufficient to catch all market movements. It proposes a framework for a proper acquisition strategy that emphasizes key aspects of competitive advantages for technology driven businesses.

  • 122730.
    Åsberg, M
    et al.
    Karolinska Institutet.
    Nygren, A
    Karolinska Institutet.
    Leopardi, Rosario
    Karolinska Institutet.
    Rylander, Gunnar
    Peterson, Ulla
    Wilczek, Lukas
    Karolinska Institutet.
    Källmén, Håkan
    Ekstedt, Mirjam
    Karolinska Institutet.
    Åkerstedt, Torbjörn
    Karolinska Institutet.
    Lekander, Mats
    Karolinska Institutet.
    Ekman, Rolf
    Novel biochemical markers of psychosocial stress in women2009In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 4, no 1, p. e3590-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Prolonged psychosocial stress is a condition assessed through self-reports. Here we aimed to identify biochemical markers for screening and early intervention in women.

    METHODS: Plasma concentrations of interleukin (IL) 1-alpha, IL1-beta, IL-2, IL-4, IL-6, IL-8, IL-10, interferon-gamma (INF-gamma), tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), thyroid stimulating hormone (TSH), total tri-iodothyronine (TT3), total thyroxine (TT4), prolactin, and testosterone were measured in: 195 women on long-term sick-leave for a stress-related affective disorder, 45 women at risk for professional burnout, and 84 healthy women.

    RESULTS: We found significantly increased levels of MCP-1, VEGF and EGF in women exposed to prolonged psychosocial stress. Statistical analysis indicates that they independently associate with a significant risk for being classified as ill.

    CONCLUSIONS: MCP-1, EGF, and VEGF are potential markers for screening and early intervention in women under prolonged psychosocial stress.

  • 122731.
    Åsberg, Per
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    A dualistic view of brand portfolios: the company's versus the customers' view2018In: Journal of Consumer Marketing, ISSN 0736-3761, E-ISSN 2052-1200, Vol. 35, no 3, p. 264-276Article in journal (Refereed)
    Abstract [en]

    Purpose Brand architecture and brand portfolios have been regarded as absolute entities to be analysed from the company's perspective. The purpose of this study is to question such a uniform view by adding a perceptional dimension to the two concepts. Design/methodology/approach Semi-structured interviews with 58 marketing professionals and customers were used to explore ten propositions and map associations in the perceived brand portfolios, based on the brand concept map methodology. Findings The study reveals systematic differences between the collective view of company representatives, who name fewer brands associated through more sophisticated and highly connected brand systems and customers who include more partners and competitor brands in the portfolio, who also name more brands and connections in total. Research limitations/implications Implications of the results are analysed and future research is suggested to determine the generalizability of the findings and the economic implications of discrepant internal and external views of a brand architecture and brand portfolio. Practical implications Academics should relate to this dualism by compensating for the effects of the associative predisposition of employees versus customers when interpreting results of studies related to brand portfolios and brand architecture. Marketing practitioners must actively acknowledge and manage the role of partners and competitors as part of the company's external brand portfolio. Originality/value This study is the first to problematize the unilateral interpretation of brand portfolios and brand architecture by introducing a dual view of these concepts based on internal (employees) and external (consumers) perceptions.

  • 122732.
    Åsberg, Per
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Perceived brand portfolios: how individual views hamper efficiency2015In: Journal of Product & Brand Management, ISSN 1061-0421, Vol. 24, no 6, p. 610-620Article in journal (Refereed)
    Abstract [en]

    Purpose – The purpose of this paper is to investigate the perceived content and structure of a brand portfolio, which may differ between individuals, by mapping the brand portfolio of two multi-national companies from the perspective of the marketing team. The discrepant views between individuals are analyzed and an aggregated brand portfolio is presented. Design/methodology/approach – Semi-structured interviews with nine marketing professionals were used to map their individual perceived brand portfolios and structure, based on the Brand Concept Map methodology. Findings – The study finds that there is a consistent difference in the individual perceived brand portfolio between marketing professionals. Brands that are not supported by all stakeholders may be suffering from an unclear positioning or undesired associations, and should receive management attention. Research limitations/implications – Explanations for the results are offered and future research is suggested to determine the generalizability of the findings and the economic implications of discrepant views on the company’s brand portfolio. Practical implications – Marketing practitioners should consider the possible effects of conflicting views within their marketing teams on business performance. Identifying brands that are not supported by all stakeholders could be a way to discover under-performing brands with problematic brand positions in need of immediate attention. Originality/value – This study is the first to compare and fully map the differences in perception of a company’s brand portfolio among internal stakeholders and the possible implications of this discrepancy.

  • 122733.
    Åsberg, Robbin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Framtagande av kärldemonteringsmaskin för att kunna materialåtervinna avfallskärl2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    SÖRAB is a company that is owned by 10 different municipals in parts north of Stockholm (Stockholm, Danderyd, Järfälla, Lidingö, Sollentuna, Solna, Sundbyberg, Täby, Upplands Väsby och Vallentuna). At the moment (2015-08-26) there are roughly 90000 two wheel garbage bins deployed in these areas (excluding Stockholm). Annually, an estimate of about 1 % of these bins has to be scraped, grinded down and recycled. Before the bins can be recycled wheels, axle-tree and plastic components needs to be separated from each other and that is why SÖRAB calls for an automated machine which can perform this task. The final aim of the project was to develop amachine which fulfilled the following specification of requirements:

    ● Time for disassembly should not exceed 2 minutes

    ● The machine should be compatible with garbage bins in the size range of 80370 liters

    ● After disassembly, the bins should be stackable

    ● The risk of accidents and/or injury’s should be low when using the machine

    ● The learning curve should not be too steep, and finally

    ● The machine should be suitable for indoors usages

    Initially a literature study was performed where the garbage bins production process, assembly, design and field of application were investigated. A function means tree was also created in order to reduce the technical problem to the most rudimentary task the machine needed to perform. This would later give a solid foundation to a brainstorming phase in which a number of different concepts were developed. The concepts were evaluated using empirical testing in a workshop environment as well as the Harris Profile method, which facilitated the selection of the most promising concept. The selected Concept were then refined into the final concept and vital partwere sized in regard to mechanics and solid mechanics. The result was a complete CAD-model created in solid modeling software Solid Edge. Drawings were also created of the parts that need to be manufactured in order to build the machine, and a complete cost analysis was performed on the material and components that is necessary in the construction phase. The material cost for the entire machine was in the end calculated to about 70 000 Swedish kronor. The empirical testing’s shows that the machine will be able to achieve most of the demands from the specification of requirements. The time for disassembly was well under 2 minutes and the machine also has capabilities to transport and stack the bins afterwards. Some concerns could be raised regarding the safety of the machine. Due to the fact that the machine consist of a relatively heavy structure that travels in relatively high speeds it is not inconceivable to believe that someone could injure themselves if they get in the way. This has to be compensated for by providing clear instruction before use or making sure that the area where the structure travels is closed off. Currently there is no control system developed to run the machine. For instance, in the future it will be necessary to add some sort of interface where the operator can communicate what sized garbage bin currently is up for disassembly to the machine. This will require some programming and was not achieved in the short time range of this project. It is recommended that SÖRAB advertises some sort of bachelor thesis assignment, or equivalent, where this can be worked out.

  • 122734.
    Åsberg, Tony
    KTH, School of Electrical Engineering (EES), Automatic Control.
    PI-control of an Electrically Actuated Throttle2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Fast and precise controlled actuators are becoming more and more important in today’s industry. One way of improving the performance of actuators is to go from a pneumatic controlled actuator to an electrically controlled actuator. Electrically controlled actuators are faster, more accurate and have a lower maintenance cost but are more complex and harder to control. In this thesis two methods for controlling an electric actuator is proposed. The actuator is a BLDC driven throttle valve used for controlling the air intake for a diesel engine where a precise amount of air is wanted to maintain optimal combustion in the engine. The proposed control methods are a PI position controller and a cascade controller consisting of three different controllers. In this thesis the model construction and simulation results are presented while hardware implementation and results are presented in another thesis [1]. The results show that the electric controlled throttle meets specific requirements set by Scania for this thesis.

  • 122735. Åsbogård, M.
    et al.
    Johannesson, L.
    Angervall, D.
    Johansson, Peter
    KTH.
    Improving system design of a hybrid powertrain using stochastic drive cycles and dynamic programming2007In: SAE technical paper series, ISSN 0148-7191Article in journal (Refereed)
    Abstract [en]

    A new approach for system design of hybrid powertrains was demonstrated in a case study. The method is based on the following presumptions: The performance of a Hybrid Powertrain Concept (HPC) is evaluated using computer simulation; a HPC cannot be correctly evaluated without an Energy Management Strategy (EMS) for the energy buffer; the optimal EMS is different for each HPC. Dynamic programming was used to generate EMSs that were optimal for the vehicles intended traffic environment and for each given HPC, enabling evaluation of a large number of HPCs. Over-adaptation of the EMSs was avoided by using a stochastic drive cycle model. The final delivery is a competitive powertrain component sizing and the corresponding optimal EMS.

  • 122736. Åsbrink, Elisabeth
    et al.
    Sörlin, SverkerPhilosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.Larsmo, Ola
    Handbok  för demokrater: : Hur gör en enskild människa göra för att skydda demokratin?2018Collection (editor) (Other (popular science, discussion, etc.))
  • 122737.
    Åslund Hedman, Emma
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Comparative Life Cycle Assessment of Jeans: A case study performed at Nudie Jeans2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Within the jeans production industry, large quantities of cotton, water and chemicals are consumed on a daily basis resulting in environmental issues decentralized around the world. An increased awareness about these environmental issues amongst companies, organizations and the consumers have initiated for environmental aspects to be considered within the jeans production processes. One such initiative is the introducing of CSR management into the business operations and strategy. In order to see how well the environmental targets and performance succeed with capturing the existing environmental issues more information about the specific products is required.

    This thesis was conducted to evaluate and compare the environmental impacts of three jeans manufactured by Nudie Jeans from a life cycle perspective and to evaluate the environmental focus at Nudie Jeans. Accordingly the main purpose has been to evaluate the environmental performance of jeans at Nudie Jeans. The main purpose have been divided into the two sub- targets:

    • To find out which of the three styles of jeans: Lean Dean Lost Legend, Tilted Tor Dry Royal Embo and Grim Tim Conjunctions, manufactured at Nudie Jeans, that has the best environmental performance and why.

    • To find out how well the prioritized environmental sustainability targets and measures represent their potential environmental impact.

    The evaluation is based on nine main environmental aspects, assessed to be relevant and of interest for the given case. The LCA has been performed according to the methodology and guidance presented in the ISO 14040-standard to ensure a methodological structure with high credibility.

    The studied products are the three styles of jeans: Lean Dean Lost Legend, Tilted Tor Dry Royal Embo and Grim Tim Conjunctions. The main difference between the products can be found in what companies and in which countries the life cycle phases: cotton cultivation, fabric manufacturing and jeans production are conducted. The results of the study show that Grim Tim Conjunctions and Tilted Tor Dry Royal Embo have the best environmental performance and the worst environmental performance can be found in Lean Dean Lost Legend. The results are mainly caused by two main process contributors, the energy sources used for electricity and heating and the substances used in the dyeing, laundry and finishing processes.

    A sensitivity analysis on the results gathered from the LCA shows that Nudie Jeans is to the largest extent focusing on the right environmental aspects. The focus on organic cotton cultivation and the promoting of repairs are highly reflecting the environmental importance within the subject, however, the measures and targets regarding energy usage could be improved to better represent its environmental importance.

  • 122738.
    Åslund, Johan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Release rates and environmental impact of zinc-nickel coatings in the automotive industry2006Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    At present the automotive industry is due to an EU directive, replacing hexavalent chrome on vehicles. This is an extensive job as hexavalent chrome is used all over the vehicle and to large extent on fasteners (screws, nuts, rivets etc.). Chrome (VI) is used as a passivating layer on mainly zinc-iron. When replacing the hexavalent chrome with a chrome (VI) free product, the passivating properties are reduced. One of the alternatives is to replace the zinc-iron coating with a zinc-nickel coating. This coating shows great promise from the corrosion resistance point of view. Zinc-nickel is a cathodically protecting coating, and will in principle dissolve to protect the substrate from corrosion. It is therefore important to understand how, and at what rates nickel is released from zinc-nickel coatings when exposed to a chloride-rich automotive environment. The potential environmental impact of nickel needs to be evaluated before Scania can introduce this alternative as corrosion protection. Tests by Scania have previously shown that contact allergy is not an issue for zinc-nickel coatings with Cr (III) passivation.

    Nickel release rates corresponding to 0,12 mg m-2yr-1 for zinc-15 % nickel coatings at a pH of 4,2 were determined from an accelerated corrosion test. Based on these values, less than 1 kg of nickel per year would be released from the Scania rolling stock if Scania were to introduce zinc-nickel coatings preferably on fasteners. This value is low compared to other sources of nickel release. In order to evaluate the toxicity of the released nickel, information about the chemical speciation, i.e. chemical forms, is needed.

    Total or dissolved metal are not good predictors of ecotoxicity of metals. Chemical speciation and bioavailability must be incorporated in toxicity testing. Total or dissolved metal may be used as a worst case approximation.

  • 122739.
    Åslund, Johan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Welding Technology. KTH, Centres, XPRES, Excellence in production research. Scania CV, Stockholm, Sweden.
    Melander, Arne
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Welding Technology. KTH, Centres, XPRES, Excellence in production research. Swerea KIMAB, Stockholm, Sweden.
    Johansson, Krister
    Scania CV, Stockholm, Sweden.
    Haglund, Sven
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Welding Technology. KTH, Centres, XPRES, Excellence in production research. Swerea KIMAB, Stockholm, Sweden.
    Hosseini, Seyed B.
    Swerea IVF, Stockholm, Sweden.
    Influence of tempering on contact fatigue2009In: New challenges in heat treatment and surface engineering, conference in honour of Prof Božidar Liščić, Dubrovnik, Cavtat, Croatia 9-12 June 2009, 2009, p. 87-94Conference paper (Refereed)
    Abstract [en]

    Most components are tempered after heat treatment operations such as case hardening orinduction hardening. The common opinion is that the martensitic structure after heat treatmentis too brittle and tempering is necessary to increase toughness.

    Tempering is an additional operation which leads to increased costs by energy, handling,and investments. Eliminating tempering from the heat treatment process leads to increasedproductivity, energy savings, and lowered environmental impact.

    Two carburised steels, Ovako 253 and 20NiCrMo2 (AISI 8620, SS2506), were tested forcontact fatigue resistance in a roller to roller rig. The tested samples were characterised withrespect to amount of fatigue damage, residual stress, amount of retained austenite andhardness. The objective was to determine if tempering is always necessary after a heattreatment operation.

    The contact fatigue tests show that tempering results in lower contact fatigue resistance.

  • 122740.
    Åslund, Johannes
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Vridning av stabiliserande torn av lådtvärsnitt med asymmetriska håltagningar i höga   byggnader2004Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 122741. Åslund, M.
    et al.
    Cederström, Björn
    KTH, Superseded Departments, Physics.
    Lundqvist, M.
    Danielsson, Mats
    KTH, Superseded Departments, Physics.
    Scatter rejection in scanned multi-slit digital mammography2004In: Proceedings of SPIE - The International Society for Optical Engineering, 2004, no 1, p. 478-487Conference paper (Refereed)
    Abstract [en]

    Measurements and Monte Carlo simulations were used to investigate the scatter properties of a scanned multi-slit digital mammography system. Scatter to primary ratio (S/P) in the center of the image field was calculated for different thickness of breast equivalent material and different tube potentials. The simulated model also varied the angular acceptance, the number of slits and the distance between the slits of a dedicated scatter rejection device. In addition to the expected scatter from the breast equivalent material, scatter within the detector contributes to the S/P-ratio. The main part of the scatter is identified as coming from this process. Measured total 5/P-ratios below 3% are reported for breast range 3-8 cm. The scatter-DQE is used as figure-of-merit for comparison to other imaging geometries and scatter rejection schemes.

  • 122742.
    Åslund, Magnus
    KTH, School of Engineering Sciences (SCI), Physics.
    Digital Mammography with a Photon Counting Detector in a Scanned Multislit Geometry2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Mammography screening aims to reduce the number of breast cancer deaths by early detection of the disease, which is one of the leading causes of deaths for middle aged women in the western world. The risk from the x-ray radiation in mammography is relatively low but still a factor in the benefit-risk ratio of screening. The characterization and optimization of a digital mammography system is presented in this thesis. The investigated system is shown to be highly dose efficient by employing a photon counting detector in a scanning multislit geometry.

    A novel automatic exposure control (AEC) is proposed and validated in clinical practise. The AEC uses the leading detector edge to measure the transmission of the breast. The exposure is modulated by altering the scan velocity during the scan. A W-Al anode-filter combination is proposed.

    The characterization of the photon counting detector is performed using the detective quantum efficiency. The effect of the photon counting detector and the multislit geometry on the measurement method is studied in detail. It is shown that the detector has a zero-frequency DQE of over 70\% and that it is quantum limited even at very low exposures.

    Efficient rejection of image-degrading secondary radiation is fundamental for a dose efficient system. The efficiency of the scatter rejection techniques currently used are quantified and compared to the multislit geometry.

    A system performance metric with its foundation in statistical decision theory is discussed. It is argued that a photon counting multislit system can operate at approximately half the dose compared to several other digital mammography techniques.

  • 122743.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Lundqvist, M
    Danielsson, M
    Optimized AEC for scanning digital mammography based on local variation of scan velocity2005In: Medical Imaging 2005: Physics of Medical Imaging, Pts 1 and 2 / [ed] Flynn, MJ, BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING , 2005, Vol. 5745, p. 468-477Conference paper (Refereed)
    Abstract [en]

    In mammography, there is an optimal photon energy and current time product that produce the required image quality at the minimal dose. The task of an automatic exposure control (AEC), in full field digital mammography (FFDM) is to minimize the dose by using optimized exposure settings. Each point in a mammogram has different radiological thickness. A conventional AEC samples the thickness in some regions to set the current time product and possibly also the beam quality. We define an ideal AEC as one that optimizes the beam quality and exposure in each point to produce a constant contrast-to-noise ratio (CNR) of structures of interest throughout the image. This paper presents the results from a theoretical evaluation of an AEC proposed for a scanning photon-counting FFDM system. The geometry enables the AEC to use information from the leading detector line to adjust the scan velocity during the scan. Thus, the irradiation can be better optimized in the scanning-direction as compared to a conventional AEC. The scan time is further reduced by increased velocity over sections that contain no tissue. The results are quantified in terms of reduction of entrance dose and scan time. The presented AEC is compared to an ideal AEC, a conventional AEC and is also benchmarked against an ideal regulator. The effect of the detector width is evaluated. Compared to a conventional AEC, both evaluated on a set of 266 mammograms, the ideal AEC would reduce the entrance dose by 39% on average while the proposed AEC for scanning systems reduces the entrance dose by 10-20% and scan-time by 25-32% on average, depending on detector width.

  • 122744.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Lundqvist, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    AEC for scanning digital mammography based on variation of scan velocity2005In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 32, no 11, p. 3367-3374Article in journal (Refereed)
    Abstract [en]

    A theoretical evaluation of nonuniform x-ray field distributions in mammography was conducted. An automatic exposure control (AEC) is proposed for a scanning full field digital mammography system. It uses information from the leading part of the detector to vary the scan velocity dynamically, thus creating a nonuniform x-ray field in the scan direction. Nonuniform radiation fields were also created by numerically optimizing the scan velocity profile to each breast's transmission distribution, with constraints on velocity and acceleration. The goal of the proposed AEC is to produce constant pixel signal-to-noise ratio throughout the image. The target pixel SNR for each image could be set based on the breast thickness, breast composition, and the beam quality as to achieve the same contrast-to-noise ratio between images for structures of interest. The results are quantified in terms of reduction in entrance surface air kerma (ESAK) and scan time relative to a uniform x-ray field. The theoretical evaluation was performed on a set of 266 mammograms. The performance of the different methods to create nonuniform fields decreased with increased detector width, from 18% to 11% in terms of ESAK reduction and from 30% to 25% in terms of scan time reduction for the proposed AEC and detector widths from 10 to 60 mm. Some correlation was found between compressed breast thickness and the projected breast area onto the image field. This translated into an increase of the ESAK and decrease of the scan time reduction with breast thickness. Ideally a nonuniform field in two dimensions could reduce the entrance dose by 39% on average, whereas a field nonuniform in only the scanning dimension ideally yields a 20% reduction. A benefit with the proposed AEC is that the risk of underexposing the densest region of the breast can be virtually eliminated.

  • 122745.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Lundqvist, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Evaluation of an AEC system for scanning photon counting mammography based on variation of scan velocityIn: Medical physics (Lancaster), ISSN 0094-2405Article in journal (Other academic)
  • 122746.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Lundqvist, Mats
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Optimization of operating conditions in photon counting multi-slit mammography based on Si-strip detectors - art. no. 61420A2006In: Medical Imaging 2006: Physics of Medical Imaging, Pts 1-3 / [ed] Flynn, MJ; Hsieh, J, 2006, Vol. 6142, p. A1420-A1420Conference paper (Refereed)
    Abstract [en]

    Measurements and simulations of the signal-difference-to-noise ratio (SDNR) and average glandular dose (AGD) have been performed on a photon counting full-field digital mammography system to determine the optimal operating conditions. Several beam qualities were experimentally evaluated by using different combinations of tube voltage, added filters and thickness of BR12 with a tungsten target x-ray tube. The SDNR and AGD were also calculated theoretically for an extended number of operating conditions and a more accurate breast model. As figure of merit for each operating condition, a spectral quantum efficiency (SQE) was calculated as the polychromatic SDNR squared over the optimal monochromatic SDNR squared at the same AGD. The theoretical model agreed within 4% relative the measured SDNR throughout the evaluated breast thickness (30-70 mm) and tube voltage range (26-38 kV). The optimization was performed with a constant SDNR-rate as compared to using a fixed filter thickness. The optimal combinations of tube voltage-filter material were: 32 kV-Ag, 34 kV-Cd, 36 kV-Sn for a breast thickness of 30, 50 and 70 mm respectively. These K-edge filter materials increased the SQE by less than 4% compared to the optimal Al filtration.

  • 122747.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Lundqvist, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Physical characterization of a scanning photon counting digital mammography system based on Si-strip detectors2007In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 34, no 6, p. 1918-1925Article in journal (Refereed)
    Abstract [en]

    The physical performance of a scanning multislit full field digital mammography system was determined using basic image quality parameters. The system employs a direct detection detector comprised of linear silicon strip sensors in an edge-on geometry connected to photon counting electronics. The pixel size is 50 mu m and the field of view 24 x 26 cm(2). The performance was quantified using the presampled modulation transfer function, the normalized noise power spectrum and the detective quantum efficiency (DQE). Compared to conventional DQE methods, the scanning geometry with its intrinsic scatter rejection poses additional requirements on the measurement setup, which are investigated in this work. The DQE of the photon counting system was found to be independent of the dose level to the detector in the 7.6-206 mu Gy range. The peak DQE was 72% and 73% in the scan and slit direction, respectively, measured with a 28 kV W-0.5 mm Al anodefilter combination with an added 2 mm Al filtration.

  • 122748.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Lundqvist, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics, Medical Imaging.
    Scatter rejection in multislit digital mammography2006In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 33, no 4, p. 933-940Article in journal (Refereed)
    Abstract [en]

    The scatter to primary ratio (SPR) was measured on a scanning multislit full-field digital mammography system for different thickness of breast equivalent material and different tube voltages. Scatter within the detector was measured separately and was found to be the major source of scatter in the assembly. Measured total SPRs below 6% are reported for breast range 3-7 cm. The performance of the multislit assembly is compared to other imaging geometries with different scatter rejection schemes by using the scatter detective quantum efficiency.

  • 122749.
    Åslund, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Fredenberg, Erik
    KTH, School of Engineering Sciences (SCI), Physics.
    Cederström, Björn
    KTH, School of Engineering Sciences (SCI), Physics.
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics.
    Spectral shaping for photon counting digital mammography2007In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 580, no 2, p. 1046-1049Article in journal (Refereed)
    Abstract [en]

    The spectral shaping properties of conventional filters have been evaluated for a photon counting digital mammography system, and the result has been compared with the theoretical spectrum from a multi-prism X-ray lens (MPL). The absorption filters and the MPL were evaluated using a theoretical model of the system which has been verified experimentally. The spectral shaping performance is quantified with the spectral quantum efficiency (SQE), calculated as the polychromatic signal-difference-to-noise ratio (SDNR) squared over the optimal monochromatic SDNR squared at the same average glandular dose. The MPL increases the SQE by 25% compared to the investigated absorption filter when compared with a Tungsten anode. This translates into a potential dose reduction of 20% at maintained SDNR.

  • 122750. Åslund, Mattias
    et al.
    Malmström, Mikael
    Swerim AB.
    Comparison of single pass and multiple pass measurements for ultrasonic attenuation2017Conference paper (Refereed)
2452245324542455245624572458 122701 - 122750 of 123549
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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