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  • 126651.
    Öhrman, Christian
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Lockhandle: Kombinerat dörrtrycke och låscylinder2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The trends on the international office security market is moving towards high tech solutions and tools like Near Field Communication, apps and fingerprint sensors are slowly replacing the old fashioned key. Despite of this, the conventional locksets and latches still remain, hidden behind the modern interfaces. For decades these standards and conventions have stood unchallenged. In a move to break these patterns and stand out of the crowd the company Dorma is looking for a alternative path. They want to introduce a ”lock handle”, a door lock that contains no electronics but only a high security cylinder lock integrated into a door handle and innovative engineering solutions.

    The aim and purpose of this project has been to meet that request and simplify the handling of indoor doors and locks.

    Aided by market studies and different suitable methods the design process generated multiple ideas and solutions which was trimmed down to three different concepts. By applying several methods that aimed to eliminate the poorer solutions and polish the better ones a final concept eventually came to be.

    This concept, that contained a new way of transferring the door handle’s momentum, was then thoroughly modelled in CAD software, simulated for abrasion resistance and later on 3D-printed as a physical model. By the conclusion of the project, the final concept met the requirements and, if taken into production, at a cost that was estimated to be equivalent to that of a conventional lockset.

  • 126652.
    Öhrn, A.
    et al.
    Department of Neutron Research, Uppsala University, Box 525, S-75120 Uppsala, Sweden.
    Blomgren, J.
    Department of Neutron Research, Uppsala University, Box 525, S-75120 Uppsala, Sweden.
    Andersson, P.
    Department of Neutron Research, Uppsala University, Box 525, S-75120 Uppsala, Sweden.
    Ataç, Ayşe
    Department of Neutron Research, Uppsala University, Box 525, S-75120 Uppsala, Sweden.
    and, 35 other co-authors
    Elastic scattering of 96 MeV neutrons from iron, yttrium, lead.2008In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 77Article in journal (Refereed)
  • 126653.
    Öhrn, Anna
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    International Real Estate Investments: – The Practice of Currency Risk Management2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Globalization is a fact in a lot of businesses today, something that is also relevant in the real estate industry. The currency differs depending on where investments are made and as a result of this real estate investors also face currency risks in addition to all other real estate related risks they already need to manage. The management of currency risk can have different forms, and the purpose of this thesis is to find out how, if and why real estate investors, especially Swedish, hedge this risk. To create an understanding of the issue, a summary of some theories on the currency market and real estate market can be found in the thesis. Only a small amount of research exists on the subject in Sweden and the theories are mainly from foreign studies and the currency risk management from other business sectors. These theories, combined with the research questions, have formed the questions for the interviews this study is made of.

    Debt in the local currency of where the investment is made can be seen as a natural hedge for the currency risk. Reduced loan-to-value (LTV) ratios from banks for real estate investments have led to a situation where loans, which can cannot be used to the same extent. That makes it more interesting to find out which other instruments are being used to avoid the currency risk and if the real estate investors wants to avoid it at all. The purpose of this thesis is to find the answers to these questions.

    The interviewed consultancy firms and banks as well as the investors themselves state that the currency risk is a risk that should not occur in Swedish real estate

    investments on markets with a different currency. The reason for this is that the real estate assets should be the primary focus of the business. To hedge this risk, bank loans and currency futures are the most frequently used instruments by Swedish real estate investors.

  • 126654.
    Öhrn Lundin, Josefin
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Entrepreneurship and innovation.
    Transparency in Global Value Chains: A Case Study on How Swedish Firms in Global Value Chains Perceive Their Level of Transparency2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is a qualitative case study on how Swedish companies operating in global valuechains percieve their level of transparency concerning social- and environmental aspects, andhow they manage this work. The thesis contributes to existing literature since it draw attentionto the role of transparency concerning social- and environmental aspects and study howcompanies operating in global value chains actually perceive their level of transparency. Theanalysis and results in this thesis is based on interviews with sustainability experts within fivedifferent Swedish companies operating in global value chains. The companies in this studydiffer in size and belong to different industries. The result shows that companies in this studydo not perceive transparency as an issue in itself; rather the ability to control the chains has animpact on the level of transparency. The level of control seems to depend on resources andstakeholders pressure, and differ depending on industry and size of the company. In thisstudy, the larger companies have more resources to control their chains than the smallercompanies and therefore they have a higher level of transparency.

  • 126655.
    Öhrn, Matz-Ola
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Företagens klimatbelastning: En fallstudie i beräkningar av CO2 ekvivalenter ur systemperspektiv - aspekter från näringslivet2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I uppsatsen undersöks ett antal aktörer från näringslivet för att se hur de beräknar sin klimatbelastning. För att få fram en så korrekt utsläppsbedömning som möjligt behöver växthusemissionerna en kvantitativ grund där primära och sekundära utsläppskällor beräknas på den senaste informationen. Denna bas blir således ett verktyg för de organisationer som vill få fram ett kvantitativt beslutsunderlag för sina utsläpps/emissions faktorer och därmed deras totala klimatbelastning. Uppsatsen tar därmed upp ett mycket aktuellt och relevant tema för många företag, inte minst för de företag och organisationer som önskar klimatkompensera sina utsläpp av växthusgaser.

    En empirisk datainsamling genomfördes inom näringslivet som därefter analyserades med uppgift att belysa eventuella svårigheter som uppdagades i beräkningarna av utsläppskällorna.

  • 126656.
    Öhrner, Niklas
    et al.
    KTH, Superseded Departments (pre-2005), Biochemistry and Biotechnology.
    MARTINELLE, Mats
    KTH, Superseded Departments (pre-2005), Biochemistry and Biotechnology.
    Mattson, Anders
    Norin, T
    Hult, K
    Displacement of the equilibrium in lipase catalysed transesterification in ethyl octanoate by continous evaporation of ethanol1992In: Biotechnology letters, ISSN 0141-5492, E-ISSN 1573-6776, Vol. 14, no 4, p. 263-268Article in journal (Refereed)
    Abstract [en]

    A simple method to overcome low equilibrium conversion in lipase catalysed resolution of alcohols by transesterification was developed. Ethyl octanoate was used as acyl donor as well as solvent and the reaction equilibrium was shifted by applying reduced pressure, forcing the co-product ethanol to evaporate during the reaction. Using a lipase from Candida antarctica 2-octanol, 1-phenyl ethanol, 1-cyclohexyl ethanol and trans-2-methylcyclohexanol were resolved in good optical and chemical yields.

  • 126657.
    Öhrström, Magnus
    KTH, Superseded Departments, Electrical Systems.
    Fast fault detection for power distribution systems2003Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    The main topic of this licentiate thesis is fast faultdetection. The thesis summaries the work performed in theproject“Fast fault detection for distributionsystems”.

    In the first chapters of the thesis the term“fast”is used in a general manner. The term is laterdefined based upon considerations and conclusions made in thefirst chapters and then related to a specific time.

    To be able to understand and appreciate why fast faultdetection is necessary, power system faults and theirconsequences are briefly discussed. The consequences of a faultare dependent of a number of different factors, one of thefactors being the duration of the fault.

    The importance of the speed of the fault detection dependson the type of equipment used to clear the fault. A circuitbreaker which interrupt currents only when they pass through anatural zero crossing might be less dependent on the speed ofthe fault detection than a fault current limiter which limitsthe fault current before it has reached its first prospectivecurrent peak.

    In order to be able to detect a fault in a power system, thepower system must be observed, i.e., measurements of relevantquantities must be performed so that the fault detectionequipment can obtain information of the state of the system.The fault detection equipment and some general methods of faultdetection are briefly described.

    Some algorithms and their possible adaptation to fast faultdetection are described. A common principle of many algorithmsare that they assume that either a signal or the power systemobject can be described by a model. Sampled data values arethen fitted to the model so that an estimate of relevantparameters needed for fault detection is obtained. An algorithmwhich do not fit samples to a model but use instantaneouscurrent values for fault detection is also described andevaluated.

    Since the exact state of a power system never is known dueto variations in power production and load, a model of thepower system or of the signal can never be perfect, i.e., theestimated parameter can never be truly correct. Furthermore,errors from the data acquisition system contribute to the totalerror of the estimated parameter.

    Two case studies are used to study the performance of the(modified) algorithms. For those studies it has been shown thatthe algorithms can detect a fault within approximately 1msafter fault inception and that one of the algorithms candiscriminate between a fault and two types of common powersystem transients (capacitor and transformer energization).

    The second case study introduced a system with two sourceswhich required a directional algorithm to discriminate betweenfaults inside or outside the protection zone.

    It is concluded that under certain assumptions it ispossible to detect power system faults within approximately 1msand that it is possible to discriminate a power system faultfrom power system transient that regularly occurs within powersystems but which not are faults.

  • 126658.
    Öhrström, Magnus
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Geidl, M.
    Söder, Lennart
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Andersson, G.
    Evaluation of travelling wave based protection schemes for implementation in medium voltage distribution systems2005In: IEE Conference Publication, 2005, Vol. 3, no 2005-11034, p. 481-483Conference paper (Refereed)
    Abstract [en]

    This paper investigates travelling wave based protection schemes developed for high voltage transmission systems and their adaptation to medium voltage distribution networks in order to enable ultra high speed relaying (within a quarter of a cycle of the power frequency) on a medium voltage level. After different travelling wave algorithms are evaluated using simple test systems, they are applied to an industrial power system where fault detection within one millisecond is required. Difficulties that arise from typical characteristics of medium voltage distribution systems are outlined and requirements to measurement and signal processing systems are discussed.

  • 126659.
    Öhrström, Magnus
    et al.
    KTH, Superseded Departments, Electrical Systems.
    Söder, Lennart
    KTH, Superseded Departments.
    A comparison of two methods used for voltage dip characterization2003In: 2003 IEEE Bologna Power Tech Conference Proceedings, 2003, Vol. 4, p. 6-Conference paper (Refereed)
    Abstract [en]

    The quality of delivered power is a topic that has received quite a lot of attention lately. Among power quality related phenomena, voltage dips (or sags) have been identified as a great concern for especially industrial customers. In order to estimate the severity of a voltage dip, several methods for characterization has been developed. A straightforward method of voltage dip characterization is to calculate the lowest magnitude of the RMS-voltage during the dip. Another method characterizes a voltage dip by the so-called characteristic voltage. These two methods are applied to measured voltage dips at a Swedish steel factory. This study shows that the two methods give similar results. Hence, characterization of voltage dips by using RMS-voltages can be a good measure of the severity of a dip even though more sophisticated methods exist.

  • 126660.
    Öhrström, Magnus
    et al.
    KTH, Superseded Departments, Electrical Systems.
    Söder, Lennart
    KTH, Superseded Departments.
    Fast fault detection for power distribution systems2002In: Proceedings of the IASTED conference Power and Energy systems, 2002Conference paper (Refereed)
    Abstract [en]

    This paper discusses aspects of fault detection for power systems which require fault removal before the first peak current after the initiation of a short circuit fault. Firstly, speed of fault detection is discussed and in particular how “fast” fault detection should be interpreted in this paper. Secondly, apparatus that would benefit from fast fault de tection is described and in what kind of power systems it could be used. Finally, algorithms appropriate for use in fast fault detection are discussed and analysed in a case study with respect to fault current levels, and requirements for fault detection equipment including detection time and sampling rate.

  • 126661. Öhrwall Rönnbäck, A
    et al.
    Ölundh Sandström, Gunilla
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Developing Integrated Product and Service Offerings: A Comparison Between Large and Small Manufacturing Firms’ Business2007Conference paper (Refereed)
  • 126662.
    Öijerholm, Johan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Ionic Transport in Metal Oxides Studied in situ by Impedance Spectroscopy and Cyclic Voltammetry2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Ionic transport in metal oxides is crucial for the functioning of a broad range of different components, such as heat resistant alloys designed for high temperature applications and oxide electrolytes in solid oxide fuel cells. This thesis presents results from in situ electrochemical studies of properties related to ionic transport in metal oxides that are important for their applications as protective oxides and ionic conductors.

    Heat resistant alloys of alumina-former type are known to form an adherent, slowly growing and protective aluminium oxide (Al2O3) scale that protects metals from chemical degradation at high temperature. In situ impedance spectroscopy was used to study highly pure and dense samples of a-alumina in the temperature range 400 – 1000 °C. It was shown that surface conduction on the sample could severely distort the measurement below 700 °C. The magnitude of the distortions appeared to be sensitive to the type of electrodes used. The use of a so-called guard electrode was shown to effectively block the surface conduction in the measurements. By varying the grain size of the sintered alpha-alumina samples, the influence of grain size on the overall conductivity of the a-alumina was studied. It was shown that the activation energy for conductivity increased as the grain size decreased. Molecular dynamics calculations were performed in order to elucidate whether Al- or O ions are dominant in the ionic conductivity of the alpha-alumina. Comparing the calculation and experimental results, the dominating charge carrier was suggested to be oxygen ions.

    Moreover, the ionic transport in thermally grown alumina-like oxide scales formed on a FeCrAl alloy was studied in situ by impedance spectroscopy between 600 and 1000 °C. It was shown that the properties of these scales differ largely from those of pure and dense alpha-alumina. Furthermore, the conductivity is mainly electronic, due to the multiphase/multilayer microstructure and substantial incorporation of species from the base metal. However, the diffusivity obtained from the ionic conductivity was in line with diffusion data in literature obtained by other methods such as thermogravimetry. Besides, the initial stage of oxidation of a number of Fe-, Ni- and Co-based alloys at temperatures between 500 and 800 °C was studied in situ by high temperature cyclic voltammetry, in which the oxygen activity was changed over a wide range. From the resulting voltammograms the redox reactions occurring on the alloy surface could be identified. It was concluded that the base metal oxidized readily on these alloys before a protective chromia- or alumina-like scale is formed. The base metal oxide is most likely incorporated into the more protective oxide.

    Further, the oxygen ionic conductivity of highly pure and fully dense yttria-stabilized zirconia produced by spark plasma sintering was studied by impedance spectroscopy. The aim was to evaluate intrinsic blocking effects on the ionic conduction associated with the space charge layer in the grain boundary region. It was observed that the ionic conductivity of the spark plasma sintered oxides is equal or slightly higher than what has been achieved by conventional sintering methods. In addition, it was shown that the specific grain boundary conductivity increases with decreasing grain size, which can be explained by a decreasing Schottky barrier height (i.e., decreasing blocking effect). The quantitative results from this work verify the space charge model describing the influence of grain size on the ionic conductivity of yttria-stabilized zirconia through dopant segregation and oxygen vacancy depletion along the grain boundaries.

  • 126663.
    Öijerholm, Johan
    KTH, Superseded Departments, Materials Science and Engineering.
    Ionic transport of α-alumina below 1000°C: an in-situ impedance spectrosocpy study2004Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Ionic conductivity of metal oxides is critical for the function of a broad range of different components, such as electrolytes in solid oxide fuel cells and alloys designed for high temperature applications. In both cases the ionic conductivity can be studied by in situ impedance spectroscopy, which is also able to reveal information on the dielectric properties of the metal oxides, and in some cases the influence of their microstructure. The focus of this thesis is on impedance spectroscopy measurements of α-alumina in the temperature range 400-1000 °C. This metal oxide has found extensive use as the protective scale on heat resistant alloys. Some unpublished work on oxygen ion conductivity of yttria-stabilized zirconia is also included.

    The low electrical conductivity of α-alumina can be a source for errors and misinterpretations during impedance spectroscopy measurements. A major disturbance originates from leakage currents that appear in the experimental setup. These leakage currents are due to conduction through the gas phase around the sample, conduction on the sample surface, or poor insulation in the sample holder. It was shown that below 700 °C, conduction on the sample surface could severely distort the measurement. The magnitude of the distortions appeared to be sensitive to the type of electrodes used. The use of a so-called guard electrode was shown to effectively block the surface conduction in the measurements.

    Conductivity of metal oxides is known to be dependent on their microstructure. Generally it is believed that ionic conductivity is favoured along grain boundaries and dislocations. The influence of microstructure on conductivity was studied for α-alumina in the temperature range 400-1000 °C. The conductivity of a series of highly pure and dense samples with narrow grain size distributions was measured by impedance spectroscopy. It appeared that the activation energy for conduction increased with decreasing grain size.

    Results based purely on impendence spectroscopy have some inherently weaknesses. For instance no information on the nature of the charge carrier can be found. Therefore the charge transport in single crystalline α-alumina was simulated by the molecular dynamics method. The results from the simulation were then compared to results from impedance measurements on single crystalline α-alumina. From the simulation it turned out that diffusion of aluminium ions had lower activation energy than diffusion of oxygen. The activation energy of oxygen was close to the measured activation energy, and the mobility of oxygen was higher than for aluminium. Therefore the dominating charge carrier was suggested to be oxygen ions.

  • 126664.
    Öijerholm, Johan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Fafilek, Günter
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Cyclic Voltammetry Study of the Early Stage of High Temperature Oxidation of Fe-, Co- and Ni-based alloysIn: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111Article in journal (Other academic)
  • 126665.
    Öijerholm, Johan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Fafilek, Günter
    Institute of Chemical Technology and Analytics, University of Technology of Vienna.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Study of Initial Oxidation of Engineering Alloys by High Temperature Cyclic Voltammetry2007In: Electrochemical and solid-state letters, ISSN 1099-0062, E-ISSN 1944-8775, Vol. 10, no 6, p. 47-50Article in journal (Refereed)
    Abstract [en]

    The initial oxidation of Fe-, Co-, and Ni-based engineering alloys was studied in situ by high-temperature cyclic voltammetry. Measurements were performed at constant temperatures between 500 and 800 degrees C in an electrochemical cell utilizing oxygen ion-conducting yttria-stabilized zirconia as electrolyte and a reference electrode whose potential is determined by the oxygen activity in the ambient gas. The recorded voltammograms show clear current peaks that are associated with the oxidation of the base metal in the investigated alloys. For the Fe- based alloy, multiple peaks are observed, showing oxidation of Fe into different valence oxides. The results indicate that the base metal oxide is formed in the initial oxidation process of these engineering alloys, which may influence long-term high-temperature oxidation resistance of the alloys.

  • 126666.
    Öijerholm, Johan
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Pan, Jinshan
    KTH, Superseded Departments, Materials Science and Engineering.
    Jönsson, Bo
    Kanthal AB, Hallstahammar.
    Influence of Grain Size on Ionic Conductivity of Pure and Dense alpha-Al2O3 in the Temperature Range 400-1000 degrees C2004In: High Temperature Corrosion And Protection Of Materials 6, Prt 1 And 2, Proceedings, 2004, Vol. 461-464, no II, p. 865-872Conference paper (Refereed)
    Abstract [en]

    Ionic transport in alpha-Al2O3 at high temperatures is important for oxidation/corrosion resistance of Al2O3-forming heat resistant alloys. Whereas most of previous studies were performed at temperatures above 1000degreesC, this work concerns the temperature range 400 to 1000degreesC. Electrical proper-ties of polycrystalline and single crystal alpha-Al2O3 were measured in air by using impedance spectroscopy in order to study the ionic transport in Al2O3. The influence of grain size was investigated by measurements on a series of highly pure and dense samples with well-defined grain size ranging from 0.5 to 15 mum, produced by the spark plasma sintering technique. The results show that the grain size has a certain influence on the conductivity in the temperature range between 650 and 1000degreesC, where the activation energy for conductivity decrease from 2.4 to 1.6 eV with increasing grain size. At lower temperatures the activation energy is about 1.0 eV and independent of the grain size, indicating a different conduction mechanism.

  • 126667.
    Öijerholm, Johan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Pan, Jinshan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Leygraf, Christofer
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    In-situ measurements by impedance spectroscopy of highly resistive alpha-alumina2006In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 48, no 1, p. 243-257Article in journal (Refereed)
    Abstract [en]

    In-situ impedance spectroscopy has been used for characterisation of oxides at elevated temperatures. However, for highly resistive oxides, the influence of electrode contact and leakage currents due to gas phase and surface conduction needs to be taken into account. In this study, IS measurements of pure and dense alpha-alumina (alpha-Al2O3) samples were performed in the temperature range 400-1000 degrees C with different types of electrode contact, in air and in nitrogen. The results show that above 700 degrees C the influence is negligible, whereas at lower temperatures the surface leakage current was substantial, and a so-called guard electrode recommendable.

  • 126668.
    Öijerholm, Johan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science (closed 20081231).
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science (closed 20081231).
    Lu, Q.
    Kanthal AB, Hallstahammar.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science (closed 20081231).
    In-situ impedence spectroscopy study of electrical conductivity and ionic transport in thermally grown oxide scales on a commercial FeCrA1 alloy2007In: Oxidation of Metals, ISSN 0030-770X, E-ISSN 1573-4889, Vol. 68, no 5-6, p. 253-269Article in journal (Refereed)
    Abstract [en]

    In-situ impedance-spectroscopy measurements were performed at temperatures between 600 and 1,000 degrees C to investigate ionic transport in oxide scales formed on Kanthal AF alloy. The samples were pre-oxidized at 800, 900 and 1,000 degrees C in air. The impedance spectra of the oxide formed at 1,000 degrees C exhibited essentially one semicircle, whereas samples oxidized at lower temperatures showed an additional semicircle at high frequencies suggesting a more heterogeneous oxide. The ionic-transference number, derived by measuring the voltage across the oxide scale, indicates that the oxide is a predominant electronic conductor. Ionic diffusivity in the oxide scales formed at different pre-oxidizing temperatures was calculated, using the ionic-transference number. The ionic diffusivities obtained in this way are in reasonable agreement with literature data acquired by other methods. The oxide-formation temperature has a significant influence on the conductivity and ionic-transport properties of the oxide scale.

  • 126669. Öjekull, J.
    et al.
    Andersson, P. U.
    Någård, M. B.
    Pettersson, J. B. C.
    Derkatch, Alik
    Neau, A.
    Rosén, S.
    Thomas, R.
    Larsson, M.
    Österdahl, Fabian
    KTH, Superseded Departments, Physics.
    Semaniak, J.
    Danared, Håkan
    Källberg, A.
    af Ugglas, M.
    Markovic, N.
    Dissociative recombination of NH4+ and ND4+ ions: Storage ring experiments and ab initio molecular dynamics2004In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 120, no 16, p. 7391-7399Article in journal (Refereed)
    Abstract [en]

    The dissociative recombination (DR) process of NH4+ and ND4+ molecular ions with free electrons has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). The absolute cross sections for DR of NH4+ and ND4+ in the collision energy range 0.001-1 eV are reported, and thermal rate coefficients for the temperature interval from 10 to 2000 K are calculated from the experimental data. The absolute cross section for NH4+ agrees well with earlier work and is about a factor of 2 larger than the cross section for ND4+. The dissociative recombination of NH4+ is dominated by the product channels NH3+H (0.85+/-0.04) and NH2+2H (0.13+/-0.01), while the DR of ND4+ mainly results in ND3+D (0.94+/-0.03). Ab initio direct dynamics simulations, based on the assumption that the dissociation dynamics is governed by the neutral ground-state potential energy surface, suggest that the primary product formed in the DR process is NH3+H. The ejection of the H atom is direct and leaves the NH3 molecule highly vibrationally excited. A fraction of the excited ammonia molecules may subsequently undergo secondary fragmentation forming NH2+H. It is concluded that the model results are consistent with gross features of the experimental results, including the sensitivity of the branching ratio for the three-body channel NH2+2H to isotopic exchange.

  • 126670. Öjekull, J.
    et al.
    Andersson, P. U.
    Någård, M. B.
    Pettersson, J. B. C.
    Neau, A.
    Rosén, S.
    Thomas, R. D.
    Larsson, M.
    Semaniak, J.
    Österdahl, Fabian
    KTH, School of Engineering Sciences (SCI), Physics, Atomic and Molecular Physics.
    Danared, H.
    Källberg, A.
    af Ugglas, M.
    Dissociative recombination of ammonia clusters studied by storage ring experiments2006In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 125, no 19, p. 194306-Article in journal (Refereed)
    Abstract [en]

    Dissociative recombination of ammonia cluster ions with free electrons has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). The absolute cross sections for dissociative recombination of H+(NH3)(2), H+(NH3)(3), D+(ND3)(2), and D+(ND3)(3) in the collision energy range of 0.001-27 eV are reported, and thermal rate coefficients for the temperature interval from 10 to 1000 K are calculated from the experimental data and compared with earlier results. The fragmentation patterns for the two ions H+(NH3)(2) and D+(ND3)(2) show no clear isotope effect. Dissociative recombination of X+(NX3)(2) (X=H or D) is dominated by the product channels 2NX(3)+X [0.95 +/- 0.02 for H+(NH3)(2) and 1.00 +/- 0.02 for D+(ND3)(2)]. Dissociative recombination of D+(ND3)(3) is dominated by the channels yielding three N-containing fragments (0.95 +/- 0.05).

  • 126671.
    Öktem, Ozan
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    Mathematics of electron tomography2015In: Handbook of Mathematical Methods in Imaging: Volume 1, Second Edition, Springer, 2015, p. 937-1031Chapter in book (Other academic)
    Abstract [en]

    This survey starts with a brief description of the scientific relevance of electron tomography in life sciences followed by a survey of image formation models. In the latter, the scattering of electrons against a specimen is modeled by the Schrödinger equation, and the image formation model is completed by adding a description of the transmission electron microscope optics and detector. Electron tomography can then be phrased as an inverse scattering problem and attention is now turned to describing mathematical approaches for solving that reconstruction problem. This part starts out by explaining challenges associated with the aforementioned inverse problem, such as the extremely low signalto- noise ratio in the data and the severe ill-posedness due to incomplete data, which naturally brings up the issue of choosing a regularization method for reconstruction. Here, the review surveys both methods that have been developed, as well as pointing to new promising approaches. Some of the regularization methods are also tested on simulated and experimental data. As a final note, this is not a traditional mathematical review in the sense that focus here is on the application to electron tomography rather than on describing mathematical techniques that underly proofs of key theorems.

  • 126672.
    Öktem, Ozan
    Sidec, Kista, Sweden.
    Reconstruction methods in electron tomography2008In: Mathematical Methods in Biomedical Imaging and Intensity-Modulated Radiation Therapy (IMRT) / [ed] Y. Censor, Jiang M., and Louis A. K., Springer Berlin/Heidelberg, 2008, p. 289-320Chapter in book (Refereed)
    Abstract [en]

    Already in 1968 one recognized that the transmission electron micro- scope could be used in a tomographic setting as a tool for structure determination of macromolecules. However, its usage in mainstream structural biology has been limited and one reason is the devastating combination of noisy data and incomplete data problems that leads to severe ill-posedness of the inverse problem. Despite these issues, the importance of electron tomography is beginning to increase, espe- cially in drug discovery. This review begins with a brief introduction to the model for image formation, i.e. the forward operator. Next, we state the difficulties and review some of the various attempts at overcoming those in solving the inverse problem.

  • 126673.
    Öktem, Ozan
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematics (Div.).
    Chen, Chong
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematics (Div.). Chinese Academy of Sciences, China.
    Onur Domaniç, N.
    Ravikumar, P.
    Bajaj, C.
    Shape-based image reconstruction using linearized deformations2017In: Inverse Problems, ISSN 0266-5611, E-ISSN 1361-6420, Vol. 33, no 3, article id 035004Article in journal (Refereed)
    Abstract [en]

    We introduce a reconstruction framework that can account for shape related prior information in imaging-related inverse problems. It is a variational scheme that uses a shape functional, whose definition is based on deformable template machinery from computational anatomy. We prove existence and, as a proof of concept, we apply the proposed shape-based reconstruction to 2D tomography with very sparse and/or highly noisy measurements.

  • 126674.
    Öktem, Ozan
    et al.
    Sidec AB, Kista, Sweden.
    Fanelli, Duccio
    University of Florens.
    Electron tomography: A short overview with an emphasis on the absorption potential model for the forward problem2008In: Inverse Problems, ISSN 0266-5611, E-ISSN 1361-6420, Vol. 24, no 1, p. 013001-Article in journal (Refereed)
    Abstract [en]

    This review of the development and current status of electron tomography deals mainly with the mathematical and algorithmic aspects. After a very brief description of the role of electron tomography in structural biology, we turn our attention to the derivation of the forward operator. Starting from the Schrodinger equation, the electron - specimen interaction is modelled as a diffraction tomography problem and the picture is completed by adding a description of the optical system of the transmission electron microscope. The first- order Born approximation enables one to explicitly express the intensity for any finite wavenumber in terms of the propagation operator acting on the specimen convolved with a point spread function, derived from the optics in the transmission electron microscope. Next, we focus on the difficulties that cause the reconstruction problem to be quite challenging. Special emphasis is put on explaining the extremely low signal- to- noise ratio in the data combined with the incomplete data problems, which lead to severe ill- posedness. The next step is to derive the standard phase contrast model used in the electron tomography community. The above- mentioned expression for the intensity generalizes the standard phase contrast model which can be obtained by replacing the propagation operator by its high- energy limit, the x- ray transform, as the wavenumber tends to infinity. The importance of more carefully including the wave nature of the electron - specimen interaction is supported by performing an asymptotic analysis of the intensity as the wavenumber tends to infinity. Next we provide an overview of the various reconstruction methods that have been employed in electron tomography and we conclude by mentioning a number of open problems. Besides providing an introduction to electron tomography written in the 'language of inverse problems', the authors hope to raise interest among experts in integral geometry and regularization theory for the mathematical and algorithmic difficulties that are encountered in electron tomography.

  • 126675.
    Öktem, Ozan
    et al.
    Sidec, Kista, Sweden.
    Quinto, Eric Todd
    Tufts University.
    Inversion of the X-ray transform from limited angle parallel beam region of interest data with applications to electron tomography2007In: Proceedings in Applied Mathematics and Mechanics: PAMM, ISSN 1617-7061, E-ISSN 1617-7061, Vol. 7, no 1, p. 1050301-1050302Article in journal (Refereed)
    Abstract [en]

    We present a new local tomographic algorithm applicable to electron microscopy tomography. Our algorithm applies to the standard data acquisition method, single-axis tilting, as well as for more arbitrary acquisition methods. Using microlocal analysis we put the reconstructions in a mathematical context, explaining which singularities are stably visible from the limited data given by the data collection protocol in the electron microscope.

  • 126676.
    Öktem, Ozan
    et al.
    Sidec Technologies, Kista, Sweden.
    Quinto, Eric Todd
    Tufts University.
    Local tomography in electron microscopy2008In: SIAM Journal on Applied Mathematics, ISSN 0036-1399, E-ISSN 1095-712X, Vol. 68, no 5, p. 1282-1303Article in journal (Refereed)
    Abstract [en]

    We present a new local tomographic algorithm applicable to electron microscope tomography. Our algorithm applies to the standard data acquisition method, single-axis tilting, as well as to more arbitrary acquisition methods including double axis and conical tilt. Using microlocal analysis we put the reconstructions in a mathematical context, explaining which singularities are stably visible from the limited data given by the data collection protocol in the electron microscope. Finally, we provide reconstructions of real specimens from electron tomography data.

  • 126677.
    Öktem, Ozan
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematics (Div.). KTH, School of Engineering Sciences (SCI), Centres, Center for Industrial and Applied Mathematics, CIAM.
    Quinto, Eric Todd
    Tufts University.
    Skoglund, Ulf
    Okinawa Institute of Science and Technology.
    Electron Lambda-tomography2009In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 106, no 51, p. 21842-21847Article in journal (Refereed)
    Abstract [en]

    Filtered back-projection and weighted back-projection have long been the methods of choice within the electron microscopy com- munity for reconstructing the structure of macromolecular assem- blies from electron tomography data. Here, we describe electron lambda-tomography, a reconstruction method that enjoys the ben- efits of the above mentioned methods, namely speed and ease of implementation, but also addresses some of their shortcomings. In particular, compared to these standard methods, electron lambda- tomography is less sensitive to artifacts that come from structures outside the region that is being reconstructed, and it can sharpen boundaries.

  • 126678.
    Öktem, Ozan
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematics (Div.).
    Rullgård, Hans
    Stockholm University.
    Skoglund, Ulf
    Karolinska Institutet.
    A component-wise iterated relative entropy regularization method with updated prior and regularization parameter2007In: Inverse Problems, ISSN 0266-5611, E-ISSN 1361-6420, Vol. 23, no 5, p. 2121-2139Article in journal (Refereed)
    Abstract [en]

    We present a componentwise iterated relative entropy regularization method (COMET) where the prior and regularization parameter could be updated in the iterates. Such a reconstruction method could be useful for multicomponent inverse problems, such as the one occurring in electron tomography. The paper also contains a brief introduction to regularization theory with emphasis on variational based regularization methods, and we rigorously prove that the tolerance-based entropy reconstruction method that occurs in the COMET iterates is a regularization method. We conclude by showing examples of COMET applied to electron tomography data.

  • 126679.
    Ölander, Tobias
    KTH, School of Biotechnology (BIO).
    Culture independent analysis of microbiota in the gut of pine weevils2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In Sweden, the pine weevil causes damages for several hundreds of millions kronor annually. The discouraged use of insecticides has resulted in that other methods to prevent pine weevil feeding needs to be found. Antifeedants found in the pine weevil own feces is one such alternative. The source of the most active antifeedants in the feces is probably from bacterial or fungal lignin degrading symbionts in the pine weevil gut. The aim of the project was to analyze the pine weevil gut microbiota with the help of culture independent methods. DNA (including bacterial DNA) was extracted from both midgut and egg cells. The extracted DNA was amplified with PCR. A clone library was created by cloning the amplified DNA into plasmid vectors and transforming the vector constructs with chemically competent cells. The clones were amplified again with either colony PCR or plasmid extraction followed by PCR, and used for RFLP (Restriction Fragment Length Polymorphism) and sequencing. Species found in the midgut sample included Acinetobacter sp., Ramlibacter sp., Chryseobacterium sp., Flavisolibacter sp. and Wolbachia sp. Species found in the egg sample included Wolbachia sp. and Halomonas sp. Wolbachia sp. and Halomonas sp. were found to be the dominant members of the midgut and egg cells respectively.

  • 126680.
    Ölme, Rasmus
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID. DOCH (Dans och Cirkushögskolan).
    From Model to Module: A move towards generative choreography2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The thesis engages in Choreography and Dance Technique by delineating the concepts and practices that the artistic research project MODUL has generated. A modular method of choreographing is articulated. The MODUL method of choreography starts by making a topographical movement analysis of the context that the work engages with. This analysis results in an identification of the different agencies at work within the context approached. They are considered as Choreographic Agents and as elements of the modular assemblage. The choreographic act then performed consists of a re-articulation of the relations between the different elements. The MODUL method links movement practice and art production as the topographical movement analysis is also applied to, and conceptualised through, the body.

    In terms of dance technique the MODUL method works with the same topographical movement analysis to explore bodily functionalities as Choreographic Agents. The technique is called Body-Self Attunement and aims at tuning the self, understood as the symbolic body, with the biological body. Body-Self Attunement does not try to unify the symbolic body and the biological body but affirms the gap as generative. The term Generative Choreography is coined in order to emphasise the performative aspect of choreography that is not defined by what it is, but what it does.

  • 126681.
    Ölmefors, Oscar
    KTH, School of Education and Communication in Engineering Science (ECE).
    Student Attitudes towards Flipped Classroom: A Focus Group Study on Attitude Change in Swedish Upper Secondary School, within Mathematics towards Flipped Classroom2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In traditional schooling, one-way monologue from teacher to student is the established way of communica­tion in the classroom. Modern pedagogues are presently breaking free of this status quo.  This master thesis explores whether there is a change in the student’s attitudes towards their school­ing and whether there is an academic benefit for the student when applying a flipped class­room model. This study was performed in Swedish upper secondary school during the students’ last course in mathematics. The study was carried out using focus group interviews and direct participat­ing observation. During the six-week period of interviews and participating in the class­room written tasks were collected and analysed, and the classroom was filmed to help analysing behav­iour of the students, both with flipped classroom and without. The outcome shows positive reac­tions from the students concerning this change in pedagogics, but also some inertia in some individuals. The result shows a positive attitude change concerning communication and collabora­tion in the classroom, although no difference in academic achievement were visible. More studies are needed, but a theoretical base needs to be built before future studies can be con­ducted. Today flipped classroom is undertheorized in ways of an academic model. Future research could be theorizing flipped classroom and exploring whether implementing this pedagogic model also brings forth a change in academic achievement apart from changing the attitudes of the stu­dents.

  • 126682.
    Ölundh, Gunilla
    KTH, Superseded Departments, Machine Design.
    Environmental and developmental perspectives of functional sales2003Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    Developing business strategies that create value forcustomers and have the potential to lower environmental impactsis considered to be a key factor for industrialized societiesto lower their environmental impact.

    The theme of this thesis has been to explore functionalsales from an environmental and developmental perspective. Ofparticular interest in this regard was to explore how theconcern for the environment has been taken into considerationwhile developing functional sales, and whether or notfunctional sales could be used as an instrument for achievingenvironmental benefits. The research has been conducted byempirical studies in six Swedish companies in the manufacturingsector, having product development and service development inspecial focus. The data collection method has mainly beenqualitative interviews.

    Academia and industry use several different terms forbusiness solutions. This confusion could lead to difficultiesin understanding each other. From an environmental perspectiveit is important to focus on what incentives to lowerenvironmental impact different business strategies give riseto.

    For the companies in the performed research the incentivesfor lowering environmental impact, stemming from functionalsales, affected the whole lifecycle of the product. Reuse,refurbishment and upgrading of products were performed inseveral companies. Several companies in the study had a strongfocus on lowering the lifecycle cost for the customer andclaimed that by internalizing costs the already existingstrategy for the companies was strengthened. The environmentalimpact of the use phase was lowered by optimizing theengineering solution or customer business. A new situationaffecting product design is that the product becomes less pricesensitive, which could lead to that more effort is put inproduct development to lower the total lifecycle cost.Environmental tools were used in product development butusually not when developing services or functional salesoffers.

    Most companies in the study added services to theirtraditional technology. For some companies new technicalsolutions gave incentive to offer functional sales since thenew technology was more expensive per operation but lowered thelifecycle cost.

    When developing functional sales offers, the complexity inthe development process increases. Functional sales developmentcould benefit from the following points:

    · Incorporating skills and expertise from all theparties involved throughout the product’s lifecycle intoproduct development. · Developing partnerships forproviding solutions to fulfill the desired functions. ·Developing the organization to handle for example financing,service and end-of-life considerations, and incorporating aservice culture into the company. · Formalizing thedevelopment process.

  • 126683.
    Ölundh, Gunilla
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Modernising ecodesign: ecodesign for innovative solutions2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The focus of environmental work in manufacturing companies has increasingly shifted from end-of-pipe solutions to the environmental performance of products and services. The product development process is central to creating value for customers. This thesis argues that companies can simultaneously create value for consumers and be profitable while taking environmental considerations into account.

    Modernising ecodesign means taking advantage of environmental benefits and the innovation potential when developing solutions rather than using ecodesign simply to ensure that legal requirements or customer demands are met. Ecodesign is a strategic issue and should be included in early product development activities, such as for project selection and when setting product targets. There is also need to perform ecodesign according to the characteristics of specific development processes as for radical product development or when developing integrated solutions, using a combination of services and products.

    This thesis reports on the findings from five different research studies, all of which adopted a qualitative approach in which the emphasis falls on exploring and creating understanding and meaning. The studies focused on three areas of ecodesign: A) rethinking approaches for manufacturing companies, B) setting environmental project targets and project selection and C) redesign of products.

    Recommendations on how to modernise ecodesign have been developed and can be summarised in six points:

    • Perform ecodesign both vertically and horizontally in a company.

    • Increase interaction between organisational units.

    • Take advantage of innovation potential in products, services, user behaviour and the delivery and take-back systems.

    • Take environmental considerations into account in the project selection process.

    • Set environmental targets for ensuring that environmental considerations are taken when developing innovative solutions.

    • Develop ecodesign procedures that fit the characteristics of the development process

  • 126684.
    Ölundh, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Ritzén, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    How Do Functional Sales Affect Product Development and Environmental Performance?2003In: Proceeding of ICED ´03 / [ed] Folkeson, A.; Gralen, K.; Norell, M.; Sellgren, U., 2003Conference paper (Refereed)
  • 126685.
    Ölundh, Gunilla
    et al.
    KTH, Superseded Departments, Machine Design.
    Ritzén, Sofia
    KTH, Superseded Departments, Machine Design.
    Making an Ecodesign Choice in Project Portfolio Management2004In: 2004 IEEE EMS International EngineeringManagement Conference: Singapore, 2004Conference paper (Refereed)
  • 126686.
    Ölundh, Gunilla
    et al.
    KTH, Superseded Departments, Machine Design.
    Ritzén, Sofia
    KTH, Superseded Departments, Machine Design.
    Making an ecodesign choice in project portfolio selection2004In: Proceedings - 2004 IEEE International Engineering Management Conference: Innovation and Entrepreneurship for Sustainable Development, 2004, p. 913-917Conference paper (Refereed)
    Abstract [en]

    Project portfolio management is about selecting the right development projects for a company in order to secure that the company is competitive. However, many companies lack a structured process for selecting new development projects. Several significant decisions are taken in the pre-specification phases of product development. Early decisions are taken that affect the environmental impact of a product. In this paper we describe a proactive environmental design approach. Environmental considerations are included into the process of selecting new project development projects and into the decision preparation phase for product development.

  • 126687.
    Ölundh, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Ritzén, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Setting Environmental Targets in Product Development2009In: ICED 09 - THE 17TH INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN, 2009, p. 35-46Conference paper (Refereed)
    Abstract [en]

    An import factor for reaching environmental improvements in product development is to have relevant environmental targets that actually influence the product development process. In this paper are procedures of setting environmental targets for product development projects identified, described and analyzed based on studies in three large companies operating in different industries. The different procedures have their own advantages and disadvantages and some of them can be combined within a company. The aim is to illustrate approaches of setting environmental targets early on and show different procedures of setting the environmental targets at a strategic level and how the way of setting environmental targets early on influences the product development process. This paper has a strong empirical connection.

  • 126688.
    Ölundh Sandström, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Janhager, Jenny
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Öhrwall Rönnbäck, Anna
    Linköping University.
    Lindahl, Mattias
    Linköping University.
    Sundin, Erik
    Linköping University.
    Sakao, Tomohiko
    Linköping University.
    Managing Innovation Processes for a Business-Driven Collaborative Network to Export Total Technical Solutions2008In: Proceedings of the 1st ISPIM Innovation Symposium: Managing Innovation in a Connected World, 2008Conference paper (Refereed)
    Abstract [en]

    There is a large need of environmental solutions at developing countries, where a network of small firms, e.g. in Sweden, have much opportunity for their business. This paper discusses, from both theoretical and from practical aspects, the high degree of complexity that needs to be managed when small firms export environmental-technology innovation to emerging markets. Especially, it deals with how a network of firms should manage its innovation processes. Based on the review of some 50 literature, the paper explains the methodologies adopted in an on-going project to study these issues. Discussions include differences with development of an integration of products/services within a single firm.

  • 126689.
    Ölundh Sandström, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Ritzén, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Functional sales as a further approach to Environmental Product Development – case study2001Conference paper (Other academic)
  • 126690.
    Ölundh Sandström, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Ritzén, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Funktionsförsäljning och produkters miljöaspekter – en studie i tre svenska tillverkningsföretag: Rapport 52342002Report (Refereed)
  • 126691.
    Ölundh Sandström, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Ritzén, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Setting Environmental Targets in Product Development so that they Really Matter2009In: Proccedings of ICED 09, International Conference on Engineering Design / [ed] Norell Bergendahl, M.; Grimheden, M.; Leifer, L.; Skogstad, P.; Lindemann, U., 2009, p. 35-46Conference paper (Refereed)
    Abstract [en]

    An important factor for reaching environmental improvements in product development is to have relevant environmental targets that actually influence the product development process. In this paper are four procedures of setting environmental targets for product development projects identified, described and analyzed based on studies in three large companies operating in different industries. The different procedures have their own advantages and disadvantages and some of them can be combined within a company. The aim is to illustrate procedures of setting environmental targets early on and show different procedures of setting the environmental targets at a strategic level and how the way of setting environmental targets early on influences the product development process. This paper has a strong empirical connection.

  • 126692.
    Ölundh Sandström, Gunilla
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Tingström, Johan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Managing Radical Innovation and Environmental Challenges: Development of a Dry Capacitor at ABB2008In: European Journal of Innovation Management, ISSN 1460-1060, E-ISSN 1758-7115, Vol. 11, no 2, p. 182-198Article in journal (Refereed)
    Abstract [en]

    Purpose – The purpose of this paper is to explore the driving forces for taking environmental considerations to a higher level in a project involving radical innovation.

    Design/methodology/approach – This qualitative case study is based on ten in-depth interviews with respondents from the development team for the DryQ project at ABB.

    Findings – In order to achieve substantial environmental benefits, radical product development is essential. Radical product development has attributes that differ from those of incremental product development. It is important that these differences be acknowledged when preparing to manage environmental challenges in development projects. In radical product development, environmental considerations should be taken into account very early on, at the strategic level of the design process.  Setting challenging environmental targets and rewarding environmental improvements was crucial to the outcome of the project presented in this paper.

    Research limitations/implications – The research presented here describes one case in one manufacturing company. Readers can, however, learn from this case and apply the insights gained to their own research or use the findings to promote new thinking in their own organisation.

    Practical implications – Suggestions are made about how to manage environmental considerations in radical product development.

    Originality/value – Few studies combine ecodesign and radical innovation theories, as is done here. Yet this is not a theoretical paper but an industry-based study of eco-innovation, from which researchers and practitioners can learn.

  • 126693. Ölvander, J.
    et al.
    Wever, R.
    Johansson, G.
    Warell, A.
    Elgh, F.
    Rönnbäck, A. Ö
    Isaksson, O.
    Larsson, T.
    Steinert, M.
    Ekman, Kalevi Edvard
    KTH.
    Hansen, P. K.
    Juuti, T.
    Malmqvist, J.
    Ritzén, S.
    Sæmundsson, R. J.
    Hansen, C. T.
    Preface2018In: 13th Biennial Norddesign Conference, NordDesign 2018Article in journal (Refereed)
  • 126694.
    Öman, Alexander
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product and Service Design.
    Sandström, Gustav
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product and Service Design.
    A Product-Service-System: For Electrolux to encourage people to produce their own vegetables at home2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nature is a scarce commodity and there is a need for efficient food production from a sustainable perspective. People do generally not have full knowledge about how to produce food in a sustainable way.

    The purpose of this project was to find individuals interested in cooking, and together with them develop a product that fit their requirements for cultivating vegetables at home. The product will in an easy way lower the threshold for growing your homegrown food, in an environmentally conscious manner.  

    Reference products, study visits and information gathering have been done to give a complete picture of what is offered, in terms of similar products, which can be found on the market today. Inspiration was gathered from these solutions to finally come up with a conceptual solution.

    The process have been a user centered iterative process, where Electrolux have provided the technical and configurative framework. The user group was encountered on three different occasions. Each of the times, a set of trigger material was presented to provoke reactions and invite discussions. 

    The results is a product which can replace an under cabinet in the kitchen and cater the needs that plants have in order to grow. It allows the user to produce their own vegetables in an indoor environment. The product is implemented in a service system where the user leases the product and has continuous access to vegetables. In addition to the product and service, a product portfolio was initiated to fit the users’ needs.

  • 126695.
    Öman, Cecilia
    KTH, Superseded Departments, Civil and Environmental Engineering.
    Emissions of organic compounds from landfills1998Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The presence of hazardous compounds in waste presents ahazard to the environment both in the short term and the longterm perspective. Landfills containing organic waste canassimilate certain levels of hazardous organic compounds sincethey offer a potential for retention and possibly degradationof organic constituents during events which occur in landfills.From a literature review the transitions of wastes andleachates with time have been compiled.

    In this thesis, specific organic compounds have beenidentified in leachates from a Swedish municipal landfill. Theresults showed considerable differences in the nature oforganic compounds identified, and the difficulty to determinethe origin of the compounds. It is not possible to analyse morethan a fraction of the organic compounds present in landfills.The organic compounds are primarily present in µg/l levelsin landfill leachates and only in exceptional cases in highconcentrations in the order of mg/l.

    A conceptual model was proposed including the most importantprocesses, sorption, water transport, transformation andevaporation. With this model, the physical, chemical andbiological characteristics of specific compounds werecorrelated to the emissions. Automatic experimental equipmentwas then developed with which different landfill processescould be examined at the µg/l concentration level. Thelaboratory equipment was used for determining the sorption oforganic compounds to actual waste. The time for reachingsorption equilibrium varied from hours to days, depending onthe hydrophobicities of the compounds. The sorption could bedescribed as linear, at least within limited concentrationintervals. The sorption was also found to be linearlycorrelated with the Kowof the compounds.

    Further the transport of organic compounds with percolatingwater through a pilot-scale landfill containing 540 m3of waste was examined. It was concluded that thewater was percolating along preferential flow paths through thelandfill, together with fractions of the added compounds.Laboratory experiments indicated that the transport of organiccompounds with mobile particles and colloids was significant.The fate of the organic compounds inside the landfill wastheoretically estimated from literature data concerningsorption, evaporation and transformation. It was concluded thata good correlation existed between the measured emissions andthe theoretically evaluated fate. It is therefore suggestedthat the emissions of organic compounds from landfills can bequalitatively predicted from literature data. Forquantitativepredictions the amount of a compound present in the landfillmust be known.

    Keywords: organic compounds, municipal landfills,sorption, transport, preferential flow

  • 126696.
    Öman, Cecilia B.
    et al.
    KTH.
    Klutsé, A.
    Rabbani, G.
    Edward, Rumila
    KTH.
    Strategy for strengthening scientific capacity in developing countries on water and sanitation related issues2009In: Desalination, ISSN 0011-9164, E-ISSN 1873-4464, Vol. 248, no 1-3, p. 658-665Article in journal (Refereed)
    Abstract [en]

    It is generally accepted that scientific research offers a tool for meeting the development demands in the area of water and sanitation. It is stressed by the authors that research should be performed by researchers in the countries most affected, on topics identified by these researchers and in their own environment. For researchers in developing countries the resources and scientific infrastructure constitutes a hindrance to scientific research. To address the situation this paper presents a strategy for scientific capacity strengthening. The strategy builds on a number of activities including; training courses on scientific methodology, literature review, fundraising, sampling, laboratory practices, statistical methods, experimental designs, participatory approaches, oral presentation, posters and manuscript development, as well as thematic workshops, workshop for revision of proposals, contacts with end-users, research grants, networks, purchasing and maintaining scientific equipment and scientific conferences. The strategy builds heavily on collaboration with local organisations. It has been concluded through assessments of activities arranged in Bangladesh, Benin, Burkina Faso, Cameroon, Ivory Coast, Ghana, Mali, Niger, Nigeria, Nepal, Sri Lanka and Togo that the strategy has been successful.

  • 126697.
    Öman, Daniel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Blomkvist, Olof
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Icke-linjär 3D finit elementanalys av genomstansade armerade betongplattor2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 126698.
    Öman, Johanna
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Total Value of Ownership for Software: Focus on Value Adding Aspects Associated with Selection and Purchase of Software2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Companies are continuously striving for saving more money in order to maintain and gain market shares as well as their competitiveness. This can be gained through better understanding for how value is created and generated and which value adding aspect to consider while purchasing a product. The concept of Total Value of Ownership, TVO, incorporates Total Cost of Ownership, TCO, as well as value adding aspects. Research initiatives have been conducted within the area of TCO but little research has been focused on revealing value adding aspects. Therefore it is of interest to find which value adding aspects that are considered to be the most important ones while purchasing a product. This thesis was initiated by Ericsson with the aim at placing the concept of TVO and value adding aspects in relation to purchase of software.

    The objective of this study is to address the issue of how value is created and to reveal which value adding aspects that are considered to be the most important ones while selecting and purchasing software in relation to the concept of TVO.

    This master thesis is conducted through a literature study and a case study at Ericsson, including a combination of interviews and a survey. Two expert interviews were also conducted and the thesis is of qualitative manner.

    TVO is a philosophy which aims at understanding the total costs and value contributions of a purchase from a particular supplier. TVO recognizes that value goes beyond cost and working capital improvements to include elements that contribute to social, environmental and innovations agendas and is related to the question; “How will this create value for our customers?

    The result shows an unclear distinction between the value adding aspects to consider while selecting and purchasing software. The four aspects that were considered to be the most important ones can though be extracted and are; (1) Reducing vendor lock-in, (2) Decreased operating costs for buyer’s customer, (3) Decreased operating costs for buyer’s customer and (4) Lowering the risk associated with purchase of software. The two most salient value adding aspects are; Fit between supplier’s offering and buyer’s demand and Reducing vendor lock-in. The findings also reveal a non cohesive view on value and what should be included in the concept.

    The conclusions of the study are that TVO enables better understanding for the costs and value associated with software. By taking in consideration both TCO and value adding aspects a product’s total value of ownership can be estimated. Questions regarding value and value adding aspects have not gained a lot of attention within the organization. There is though a willingness to try to adapt this philosophy as a part of the sourcing process which is also a trend generally.

    Concluded is also to have a cohesive view on the concept on value and have a holistic view on the value chain in order to be able to understand the total value of a software. A long-term commitment and engagement from involved parties within the organization is essential while implementing TVO.

  • 126699.
    Öman Lundin, Gustav
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Enhancements of an auto-thrustfunction using fuzzy logic2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master's thesis aims to investigate how fuzzy logic can be used to adapt the tuning of a speed control law during certain conditions such as turbulence. The objective is to lower the speed overshoot caused by the auto-thrust function as well as the general engine agitation. The main modifications studied are direct lowering of the closed loop gains, hybridisation and filtering of the longitudinal acceleration estimation. Finally, saturations or limits on the control signal as well as on the coordination with the longitudinal control law are studied in order to cope with the possible consequences of a softer control law.

    To detect the turbulence, an already existing turbulence detector is used. In addition, a wind gradient detector is designed in order to increase the gain during such wind conditions to counter ramp errors.

    It is found that a general lowering of the closed loop gain in combination with a slow hybridisation, all proportional to the detected turbulence level, together with a limitation of the coordination gives a satisfactory result. In scenarios including severe turbulence and wind gradients, the forced limits are shown to be indispensable.

    A conclusion is drawn that the fuzzy tuning is better adapted to turbulent conditions but that the wind gradient detection and the forced limits must be studied further. It is also concluded that the coupling between the closed loop gain and the acceleration hybridisation can be interesting to investigate. Moreover, additional realistic scenarios should be simulated in order to further validate the design.

    For future studies on the subject; it is recommended that the controller tuning is validated with the help of expert knowledge. Alternatively, the tuning could be handled by an ANFIS (Adaptive Neuro Fuzzy Inference System). Finally the tuning of the controller should be validated for a wider range of flight points, most importantly the forced limits since the engine response varies a lot between different points in the flight envelope.

  • 126700.
    Öman Lundin, Gustav
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    G.E.T.O.U.T.   - Group Evacuation Transport at the Occurence of Unexpected Trauma.2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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