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  • 16751.
    Bergström, Oscar
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science.
    Larsson, Jennifer
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science.
    Image Recognition for Solving Google’s reCAPTCHA: An Investigation of how Different Aspects Affects the Security of Google’s reCAPTCHA2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this project, an image recognition solver for Google’s reCAPTCHA was used to investigate how different aspects of the reCAPTCHA challenge affects its efficiency on defending against bots. The aspects that were examined was the type of reCAPTCHA challenge and the object which should be identified in the images. To conduct the study, an image recognition algorithm, trained on a large image dataset, was used in a script that interacted with a reCAPTCHA website. Testing showed that both the investigated aspects had a large impact on the efficiency, individually and in combination.

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  • 16752.
    Bergström, Petronella
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Falksveden, Kim
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Produktivitetsökning av en delprocess inom sedeltryckeri2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 16753.
    Bergström, Philip
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Multimodal Relation Extraction of Product Categories in Market Research Data2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays, large amounts of unstructured data are constantly being generated and made available through websites and documents. Relation extraction, the task of automatically extracting semantic relationships between entities from such data, is therefore considered to have high commercial value today. However, many websites and documents are richly formatted, i.e., they communicate information through non-textual expressions such as tabular or visual elements. This thesis proposes a framework for relation extraction from such data, in particular, documents from the market research area. The framework performs relation extraction by applying supervised learning using both textual and visual features from PDF documents. Moreover, it allows the user to train a model without any manually labeled data by implementing labeling functions.We evaluate our framework by extracting relations from a corpus of market research documents on consumer goods. The extracted relations associate categories to products of different brands. We find that our framework outperforms a simple baseline model, although we are unable to show the effectiveness of incorporating visual features on our test set. We conclude that our framework can serve as a prototype for relation extraction from richly format-ted data, although more advanced techniques are necessary to make use of non-textual features.

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  • 16754.
    Bergström, Rasmus
    KTH, School of Electrical Engineering (EES).
    A simulation of the propellant storage for a ice-propelled microresistojet engine: Development, verification and validation of a numerical model for the characteristics of a sublimation tank to be used as the propellant storage subsystem for a ice-propelled microresistojet engine2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An innovative design for a new type of propulsion sys-tem using sublimating water in solid form as reaction mass, accelerated via a Micro Electric Mechanical System (MEMS) Heater Chip, is currently being developed at the Space Sys-tems Engineering Department at Technische Universiteit Delft in the Netherlands. The aim of the thesis is to char-acterise the propellant storage and gain insight into the physics present in the engine.Two methods of study were used, one theoretical and one experimental. The theoretical part consisted of a one dimensional time-stepping numerical model, the experimen-tal part of a empirical test where the environment and op-erating conditions of the engine are duplicated in a vacuum chamber and data collected on the pressure and tempera-ture inside the test vial.Due to several di˙erent issues with both the model and the tests the accuracy of the obtained results were severely reduced, which made it more diÿcult to compare the ob-tained results from the tests and the model. There was some similarity between the model results and the test re-sults, but the model needs to be refined before it can be used as a input for future models or investigations. The test rig should also be refined to give more accurate refer-ence results.The study did not reveal any critical problems with the engine concept, and the engine still shows promise. The system was shown to be highly interdependent and compli-cated to simulate. Furthermore it was concluded that cre-ating a numerical model from scratch was very challenging. Furthermore the empirical testing requires a very specific environment and needs proper equipment in order to yield accurate results. Conclusions that could be made regard-ing possible future problems with the engine implementa-tion was among others the problem of creating a stable heat balance in the tank. Other issues shown was the problem of the limited power available on a typical CubeSat and that the power requirements of the engine might be larger than what the CubeSat can provide.The engine is however currently in a extremely early development stage, and needs to be further studied before any definite conclusions can be made.

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  • 16755.
    Bergström, Rasmus
    et al.
    KTH.
    Crimella, Matteo
    KTH.
    Ivchenko, Nickolay
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Karlsson, Alexander
    KTH.
    Lindberg, Hannah
    KTH.
    Persson, Linnea
    KTH.
    Schlatter, Nicola
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Westerlund, Simon
    KTH.
    SCATTERING OF RADAR WAVES ON AEROSOLS IN PLASMAS2015In: EUROPEAN ROCKET AND BALLOON: PROGRAMMES AND RELATED RESEARCH, 2015, p. 87-94Conference paper (Refereed)
    Abstract [en]

    To study the physical mechanisms of phenomena such as polar mesospheric summer echoes, the SCRAP (Scattering of Radar waves on Aerosols in Plasmas) experiment aimed to validate theories on density fluctuations in dusty plasmas. The SCRAP team developed two identical free falling units (FFUs) designed to create a cloud of copper particles once they eject from the REXUS17 sounding rocket 124 seconds after launch. By using the EISCAT incoherent scatter radar system to observe the cloud, the SCRAP experiment proposed to relate theoretical predictions to a controlled object. The SCRAP experiment was launched from ESRANGE on March the 17th 2015. The FFUs GPS signal was lost during launch and the units were therefore not found. Moreover, no backscattering from the copper cloud was observed by the radar.

  • 16756.
    BERGSTRÖM, RIKARD
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Sustainability and Industrial Dynamics.
    PETER HALLBERG, PETER
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Sustainability and Industrial Dynamics.
    Trading Places in the Heating Market?: Exploring the prospects of district heating and geothermal heating for apartment buildings and premises in urban areas2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The 100 billion SEK heating industry is currently experiencing industrial change where new business models are required to maintain and create competitive advantage. The market is more fragmented and unpredictable than ever before and what historically has been seen as obvious is no longer apparent. Destructive technology from geothermal heating (GH) is reinforcing the urban areas. This is a strong and environmental friendly technology, but so is also district heating (DH).

    The purpose of this paper is to analyse the prospects of district heating and geothermal heating and the arising competitive landscape that is trembling the heating market. This has been compiled through comprehensive investigation of the heating market and through relevant theories derived from industrial change.

    The findings shows that customers possess a strong confidence towards GH. It has also been shown that real estate firms and private housing associations values heating from different point of views. The real estate’s adopts to GH mainly to diverse business risk, whereas private housing associations adopts as result of lock-in effects and poor price transparency from the DH supplier. Moreover, it has been shown that GH diffusion have a strong correlation with DH price and only minor or no correlation with GDP, interest rate, or electricity price in the short run, which was an overall market view. However, not surprisingly, the outer forces are confirmed to have a very significant impact on the prospects of DH and GH. The consequences of the long-term conversion to renewable electricity by 100 percent, and the system perspective, on how to measure the consumed energy remain factors that are difficult to predict but indeed have a major impact. GH is assumed to continue to claim market shares unless the DH supplier are revising or/and redefining their business models.

  • 16757.
    Bergström, Roger
    KTH, Superseded Departments (pre-2005), Fibre and Polymer Technology.
    Fibre flocculation during twin-wire roll forming2003Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    At the division of Paper Technology a forming unitconsisting of headbox, forming roll unit and reservoir systemfor suspension recirculation has been constructed, with themain purpose to experimentally study the paper forming event byvisually following the fibre flow phenomena in the formingzone.

    The effect of various running parameters upon the pressuredistribution, which is in correlation to the flow phenomenaoccuring during forming, has been studied with a flush mountedpressure sensor. Some combinations of running parametersresulted in highly oscillating pressure pulses, which wereevaluated by their wavelength.

    The visualisation was made with a high-speed video cameraand a pulsed laser light source. The forming zone was observedvia a mirror mounted on the forming roll, thus following aspecific small area of the forming zone. This made it possibleto follow floc motions relative to the forming roll/wire. Theflocs were found to move towards the wire due to the dewateringflow wereupon the bottom part of the floc was pinned to thewire. If the suspensionspeed is different from the wire speedthe floc will be stretched out, because the upper part of thefloc has a slightly different speed in comparison to the bottompart. If this speed difference is high enough, the flocs maysplit and thus contribute to fragmentation.

    The floc-floc interaction has been studied in a Couetteapparatus. It has been observed that voids in the suspensionplay a central role for the floc break-up process. The reasonis belived to be that voids induce movement inside thesuspension, which is a prerequisite for floc break-up. Thefloc-floc relative movements have been found to obey simplelaws of rack-and-pinion principles.

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  • 16758.
    Bergström, Roger
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fibre flow mechanisms2005Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The flow behaviour, and primarily the floc-floc interaction, of pulp paper suspensions have been studied visually. Analogy models based on these observations have been developed as well as the identification of important parameters of floc break-up in low shear rate flow fields. Floc compressions and the locations of voids (areas of lower fibre concentration) where found to influence the floc splitting mechanism. Based on this investigation an equipment for measuring the load carrying ability of fibre flocs and networks was designed, and the effect of measurement geometry, network structure and fibre suspension concentration was investigated. The load carrying ability with concentration increases rapidly when going from 1% to 2% in initial suspension concentration.

    A model handling the fibre floc behaviour during extension and compression has been developed, and some basic flocculated flow mechanisms are discussed on an analogy basis. A modified Voigt element is use, describing mainly the compressional behaviour and plastic behaviour of loose fibre network structures. Further the pos- sibility of stress chain formation is discussed on a fibre level as well as on a floc level.

    The effect of fibre flow (shear field) occurring in the forming zone of a roll former has been studied in detail. Basic forming mechanisms on floc scale has been investi- gated, and the effect of running parameters like dewatering pressure and jet-to-wire speed difference as well as the fibre type and concentration of the pulp suspension has been evaluated. It is evident that floc elongation increases with shear rate (jet-to-wire speed difference) and lower dewatering rate. The latter is because the fibre floc is subjected to the shear field longer due to slower immobilisation. Shorter fibre tends to create weaker networks, which promotes a higher elongation of the flocs.

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  • 16759.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Björkman, Ulf H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Basic physics of suspended fibre flow systems: I. System scales and basic thermodynamicsManuscript (Other academic)
  • 16760.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Björkman, Ulf H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Basic physics of suspended fibre flow systems: II. Analogy modelsManuscript (Other academic)
  • 16761.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Björkman, Ulf H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Material parameters of suspended wood fibre networks: I. Methods of measurementManuscript (Other academic)
  • 16762.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Björkman, Ulf H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Material parameters of suspended wood fibre networks: II. MeasurementsManuscript (Other academic)
  • 16763.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Björkman, Ulf H.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Stress chains in fibre suspensions: a formation scenarioManuscript (Other academic)
  • 16764.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Björkman, Ulf H.
    The interaction between fibre flocs in shear flow fieldsManuscript (Other academic)
  • 16765.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Norman, Bo
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Floc behaviour during roll formingManuscript (Other academic)
  • 16766. Bergström, Roger
    et al.
    Sörlin, Sverker
    KTH, School of Architecture and the Built Environment (ABE), Philosophy and History, History of Science, Technology and Environment.
    Danell, Kjell
    von Essen, Hans
    Mörner, Torsten
    Utbildning och forskning2016In: Jaktens historia i Sverige: Vilt – människa – samhälle – kultur, Stockholm: Liber Hermods , 2016, p. 291-300Chapter in book (Other academic)
  • 16767.
    Bergström, Roger
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Åkesson, Krister
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Norman, Bo
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    A twin-wire model gap former: design and evaluation methods2006In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 21, no 1, p. 54-58Article in journal (Refereed)
    Abstract [en]

    A one-sided model twin wire gap former, the KTH-former has been developed. The former consists of headbox with transparent gables, forming unit, including a forming roll with a transparent surface and outer forming wire and a reservoir system for water/fibre suspension handling. To allow the study of blade forming, a blade can be introduced against the outer wire to generate a pressure pulse.

    Two measurement techniques have been utilized to study the flow mechanisms of fibre suspension flow in the forming zone;

    A pressure sensor has been used to study the dewatering pressure along the forming zone.

    A high speed video system was used to visually study the suspension flow.

    The study was made with pulp fibres. Fibre floes were introduced in the center of the headbox at the beginning of the linear nozzle contraction, by an introduction tube with an inner diameter of 10 mm. The acceleration in the nozzle contraction was used to separate the fibre floes in the Suspension making them move individually, thus making the visualisations easier. To avoid the problem of floc break-down at nozzle exit when using a conventional linear nozzle with parrot's beak outlet, two Curved contraction blocs were inserted, giving a more constant acceleration profile, letting the floes keep their integrity in the emerging jet.

    The high speed video system had two main arrangements, for the Study of floc behaviour in the forming zone. A mirror installed on the machine structure visualised a certain area of the forming zone. Alternatively, a mirror fastened to the back plate of the forming roll followed a specific area of the wire (and roll), making it possible to follow the floes through the entire forming zone. It is then possible to detect any relative motion between floes and wire.

  • 16768.
    Bergström, Sara
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Upplev det Stora Alvaret2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Öland has always been dear to me, that’s why I chose to work with this site. This project is about how the architecture appears and meet the landscape Stora Alvaret, but its also about what’s happening there and how the architecture effects you and makes it possible to experience this great landscape.

    My intention is to create architecture that enhances the Stora alvaret, the nature and the atmosphere. An oasis for our well being and an opportunity to experience the nature during all different seasons. An unique place that could benefit the local business and draw more people to the Island and the world heritage.

    My strategy is to create a point that works as an the center of the world heritage and the south of Öland. A destination and a starting point for several activities and sites. A visitor center and a landscape hotel. I believe that a culture heritage is not something that you just read about, it something that needs to be experienced!

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    Upplev det Stora Alvaret
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    Thesis Booklet
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    Reflektion
  • 16769.
    Bergström, Sebastian
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematical Statistics.
    Customer segmentation of retail chain customers using cluster analysis2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis, cluster analysis was applied to data comprising of customer spending habits at a retail chain in order to perform customer segmentation. The method used was a two-step cluster procedure in which the first step consisted of feature engineering, a square root transformation of the data in order to handle big spenders in the data set and finally principal component analysis in order to reduce the dimensionality of the data set. This was done to reduce the effects of high dimensionality. The second step consisted of applying clustering algorithms to the transformed data. The methods used were K-means clustering, Gaussian mixture models in the MCLUST family, t-distributed mixture models in the tEIGEN family and non-negative matrix factorization (NMF). For the NMF clustering a slightly different data pre-processing step was taken, specifically no PCA was performed. Clustering partitions were compared on the basis of the Silhouette index, Davies-Bouldin index and subject matter knowledge, which revealed that K-means clustering with K = 3 produces the most reasonable clusters. This algorithm was able to separate the customer into different segments depending on how many purchases they made overall and in these clusters some minor differences in spending habits are also evident. In other words there is some support for the claim that the customer segments have some variation in their spending habits.

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  • 16770.
    Bergström, Simon
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Gottsunda Kulturhus2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This is a project for a public building composed of a program with great variation. It has been formed into a whole that still displays diversity. The idea of the structure and the large common entrance hall functions as the uniting gestures. The intention is that all activities can be performed separately or in cooperation with each other. The structure preforms in different ways, it frees up space, has a strong expression, and makes the experience of the building more coherent. Spaces are made clearly articulated by simple forms and patterns of movement. This proposal is aimed to make culture grow in the individual and collective.

  • 16771.
    Bergström, Sofia
    KTH, School of Biotechnology (BIO).
    Kidney disease-related protein profiling2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 16772.
    Bergström, Sofia
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Modelling Business Capabilities withEnterprise Architecture: A Case Study at a Swedish Pension Managing Company2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis looks at the use of business capabilities within enterprisearchitecture, and investigates how the concept is used within the Swedish pension managingcompany Folksam. Based on interviews with stakeholders an enterprise architecture metamodelcentred on the business capability is constructed. The meta-model is then edited andrevised according to a questionnaire aimed at removing irrelevant elements, and a secondset of interviews discussing a capability's health status and well being. This second set ofinterviews resulted in the removal of elements not aecting the well being of a capability.The nal meta-model has the business capability and the capability health status at itscore. It consists of the Capability element, with two attributes, surrounded by nine otherelements connected by eleven relations in total.

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  • 16773.
    Bergström, Sofia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Multiplexed antibody-based protein profiling in the pursuit of CSF biomarkers for neurodegenerative diseases2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is a desire for a transition from generic treatments designed for the average patient, towards more individual-based precision medicine. An increased knowledge about disease pathophysiology on a molecular level would be beneficial for this transition. The study of proteins can contribute with valuable insights into etiology and pathogenesis of different diseases and thereby aid the clinical assessment of patients and guide future treatments.

    Neurodegenerative disorders, such as Alzheimer’s disease, Parkinson’s disease, and frontotemporal dementia, are characterized by a progressive loss of function, and eventually death of neurons. Neurons allow the brain to communicate with the rest of the body, and a deteriorated function of neurons can result in problems with mobility or mental functions. Neurodegenerative diseases progress slowly over many years, with a long silent asymptomatic phase before symptom onset. It is hard to rebuild what is already lost, but disease-modifying treatments might be able to slow down or halt the deterioration of the brain. Therefore, there is a major research focus on investigating the early stages of disease pathogenesis in order to elucidate this critical phase in disease progression.

    The four papers included in this thesis focus on identifying altered protein profiles in cerebrospinal fluid from patients with neurodegenerative diseases. For this purpose, multiplexed antibody-based suspension bead arrays have been used. This method allows for hundreds of proteins to be analyzed in hundreds of samples in the same assay. Paper I focuses on Alzheimer’s disease and investigates the profiles of 200 proteins when comparing patients with controls. Six proteins were identified at altered levels and were further investigated in relation to the progression from mild cognitive impairment to Alzheimer’s disease. Paper II explores 100 protein profiles in relation to the core Alzheimer’s disease biomarkers in asymptomatic 70-year-olds to elucidate patterns preceding potential disease onset. Paper III investigates the transition to cognitive impairment in patients with Parkinson’s disease and explores potential associations between protein profiles and cognitive assessment tests. Finally, Paper IV explores panels of proteins in the context of frontotemporal dementia. Panels of proteins, instead of single biomarkers, have an increased potential to capture the range of biological processes within these types of complex and multifactorial diseases.

    Neurodegenerative diseases are often heterogeneous which puts high demands on the study design including an appropriate selection of study population. However, significant similarities are also present which makes it advantageous to have a broad perspective and work with several neurodegenerative disorders. This thesis presents the results from multiplexed antibody-based protein profiling as a contribution to a better understanding of neurodegenerative diseases.

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  • 16774.
    Bergström, Sofia
    et al.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Linn, Öijerstedt
    Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden; Unit for Hereditary Dementias, Theme Aging, Karolinska University Hospital, Solna, Sweden.
    Remnestål, Julia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Olofsson, Jennie
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Ullgren, Abbe
    Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden..
    Seelaar, Harro
    Department of Neurology, Erasmus Medical Centre, Rotterdam, Netherlands.
    van Swieten, John C
    Department of Neurology, Erasmus Medical Centre, Rotterdam, Netherlands.
    Synofzik, Matthis
    Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany; Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany.
    Sanchez-Valle, Raquel
    Alzheimer’s disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clínic, Institut d’Investigacións Biomèdiques August Pi I Sunyer, University of Barcelona, Barcelona, Spain.
    Moreno, Fermin
    Cognitive Disorders Unit, Department of Neurology, Donostia University Hospital, San Sebastian, Gipuzkoa, Spain; Neuroscience Area, Biodonostia Health Research Institute, San Sebastian, Gipuzkoa, Spain.
    Finger, Elizabeth
    Department of Clinical Neurological Sciences, University of Western Ontario, London, Ontario, Canada.
    Masellis, Mario
    Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, University of Toronto, Toronto, Canada.
    Tartaglia, Carmela
    Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada.
    Vandenberghe, Rik
    Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Leuven, Belgium; Neurology Service, University Hospitals Leuven, Belgium; Leuven Brain Institute, KU Leuven, Leuven, Belgium.
    Laforce, Robert
    Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques, CHU de Québec, and Faculté de Médecine, Université Laval, QC, Canada.
    Galimberti, Daniela
    Fondazione IRCCS Ospedale Policlinico, Milan, Italy; University of Milan, Centro Dino Ferrari, Milan, Italy.
    Borroni, Barbara
    Centre for Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, University of Brescia, Italy.
    Butler, Chris R
    Nuffield Department of Clinical Neurosciences, Medical Sciences Division, University of Oxford, Oxford, UK; Department of Brain Sciences, Imperial College London, UK.
    Gerhard, Alexander
    Division of Neuroscience and Experimental Psychology, Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK; Departments of Geriatric Medicine and Nuclear Medicine, University of Duisburg- Essen, Germany.
    Ducharme, Simon
    Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, Québec, Canada; McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.
    Rohrer, Jonathan D
    Department of Neurodegenerative Disease, Dementia Research Centre, UCL Institute of Neurology, Queen Square, London, UK.
    Månberg, Anna
    Division of Affinity Proteomics, Department of Protein Science, KTH Royal Institute of Technology, SciLifeLab, Stockholm, Sweden.
    Graff, Caroline
    Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden; Unit for Hereditary Dementias, Theme Aging, Karolinska University Hospital, Solna, Sweden.
    Nilsson, Peter
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    A panel of CSF proteins separates genetic frontotemporal dementia from presymptomatic mutation carriers: a GENFI studyManuscript (preprint) (Other academic)
  • 16775.
    Bergström, Sofia
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Oijerstedt, Linn
    Swedish FTD Initiat, Stockholm, Sweden.;Karolinska Univ Hosp, Theme Aging, Unit Hereditary Dementias, Dept Neurobiol Care Sci & Soc,Div Neurogeriatr,Ka, Solna, Sweden.;Karolinska Univ Hosp, Unit Hereditary Dementias, Theme Aging, Solna, Sweden..
    Remnestål, Julia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Olofsson, Jennie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Ullgren, Abbe
    Swedish FTD Initiat, Stockholm, Sweden.;Karolinska Univ Hosp, Theme Aging, Unit Hereditary Dementias, Dept Neurobiol Care Sci & Soc,Div Neurogeriatr,Ka, Solna, Sweden..
    Seelaar, Harro
    Erasmus MC, Dept Neurol, Rotterdam, Netherlands..
    van Swieten, John C.
    Erasmus MC, Dept Neurol, Rotterdam, Netherlands..
    Synofzik, Matthis
    Univ Tubingen, Hertie Inst Clin Brain Res, Dept Neurodegenerat Dis, Tubingen, Germany.;Univ Tubingen, Ctr Neurol, Tubingen, Germany.;Ctr Neurodegenerat Dis DZNE, Tubingen, Germany..
    Sanchez-Valle, Raquel
    Univ Barcelona, Inst Invest Biomed August Pi I Sunyer, Hosp Clin, Alzheimers Dis & Other Cognit Disorders Unit,Neur, Barcelona, Spain..
    Moreno, Fermin
    Donostia Univ Hosp, Dept Neurol, Cognit Disorders Unit, San Sebastian, Gipuzkoa, Spain.;Biodonostia Hlth Res Inst, Neurosci Area, San Sebastian, Gipuzkoa, Spain..
    Finger, Elizabeth
    Univ Western Ontario, Dept Clin Neurol Sci, London, ON, Canada..
    Masellis, Mario
    Univ Toronto, Sunnybrook Hlth Sci Ctr, Sunnybrook Res Inst, Toronto, ON, Canada..
    Tartaglia, Carmela
    Univ Toronto, Tanz Ctr Res Neurodegenerat Dis, Toronto, ON, Canada..
    Vandenberghe, Rik
    Katholieke Univ Leuven, Lab Cognit Neurol, Dept Neurosci, Leuven, Belgium.;Univ Hosp Leuven, Neurol Serv, Leuven, Belgium.;Katholieke Univ Leuven, Leuven Brain Inst, Leuven, Belgium..
    Laforce, Robert
    Univ Laval, CHU Quebec, Dept Sci Neurol, Clin Interdisciplinaire Mem, Quebec City, PQ, Canada.;Univ Laval, Fac Med, Quebec City, PQ, Canada..
    Galimberti, Daniela
    Fdn IRCCS Osped Policlin, Milan, Italy.;Univ Milan, Ctr Dino Ferrari, Milan, Italy..
    Borroni, Barbara
    Univ Brescia, Ctr Neurodegenerat Disorders, Dept Clin & Expt Sci, Brescia, Italy..
    Butler, Chris R.
    Univ Oxford, Nuffield Dept Clin Neurosci, Med Sci Div, Oxford, England.;Imperial Coll London, Dept Brain Sci, London, England..
    Gerhard, Alexander
    Univ Manchester, Wolfson Mol Imaging Ctr, Div Neurosci & Expt Psychol, Manchester, Lancs, England.;Univ Duisburg Essen, Dept Geriatr Med, Duisburg, Germany.;Univ Duisburg Essen, Dept Nucl Med, Duisburg, Germany..
    Ducharme, Simon
    McGill Univ, Douglas Mental Hlth Univ Inst, Dept Psychiat, Montreal, PQ, Canada.;McGill Univ, McConnell Brain Imaging Ctr, Montreal Neurol Inst, Montreal, PQ, Canada..
    Rohrer, Jonathan D.
    UCL Inst Neurol, Dementia Res Ctr, Dept Neurodegenerat Dis, Queen Sq, London, England..
    Manberg, Anna
    Univ Toronto, Sunnybrook Hlth Sci Ctr, Sunnybrook Res Inst, Toronto, ON, Canada..
    Graff, Caroline
    Swedish FTD Initiat, Stockholm, Sweden.;Karolinska Univ Hosp, Theme Aging, Unit Hereditary Dementias, Dept Neurobiol Care Sci & Soc,Div Neurogeriatr,Ka, Solna, Sweden.;Karolinska Univ Hosp, Unit Hereditary Dementias, Theme Aging, Solna, Sweden..
    Nilsson, Peter
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    A panel of CSF proteins separates genetic frontotemporal dementia from presymptomatic mutation carriers: a GENFI study2021In: Molecular Neurodegeneration, E-ISSN 1750-1326, Vol. 16, no 1, article id 79Article in journal (Refereed)
    Abstract [en]

    Background A detailed understanding of the pathological processes involved in genetic frontotemporal dementia is critical in order to provide the patients with an optimal future treatment. Protein levels in CSF have the potential to reflect different pathophysiological processes in the brain. We aimed to identify and evaluate panels of CSF proteins with potential to separate symptomatic individuals from individuals without clinical symptoms (unaffected), as well as presymptomatic individuals from mutation non-carriers. Methods A multiplexed antibody-based suspension bead array was used to analyse levels of 111 proteins in CSF samples from 221 individuals from families with genetic frontotemporal dementia. The data was explored using LASSO and Random forest. Results When comparing affected individuals with unaffected individuals, 14 proteins were identified as potentially important for the separation. Among these, four were identified as most important, namely neurofilament medium polypeptide (NEFM), neuronal pentraxin 2 (NPTX2), neurosecretory protein VGF (VGF) and aquaporin 4 (AQP4). The combined profile of these four proteins successfully separated the two groups, with higher levels of NEFM and AQP4 and lower levels of NPTX2 in affected compared to unaffected individuals. VGF contributed to the models, but the levels were not significantly lower in affected individuals. Next, when comparing presymptomatic GRN and C9orf72 mutation carriers in proximity to symptom onset with mutation non-carriers, six proteins were identified with a potential to contribute to a separation, including progranulin (GRN). Conclusion In conclusion, we have identified several proteins with the combined potential to separate affected individuals from unaffected individuals, as well as proteins with potential to contribute to the separation between presymptomatic individuals and mutation non-carriers. Further studies are needed to continue the investigation of these proteins and their potential association to the pathophysiological mechanisms in genetic FTD.

  • 16776.
    Bergström, Sofia
    et al.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Remnestål, Julia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Olofsson, Jennie
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Markaki, Ioanna
    Karolinska Institutet.
    Carvalho, Stephanie
    Institut du Cerveau et de la Moelle épinière, Sorbonne Université.
    Corvol, Jean-Christophe
    Institut du Cerveau et de la Moelle épinière, Sorbonne Université.
    Kultima, Kim
    Uppsala Universitet.
    Kilander, Lena
    Uppsala Universitet.
    Löwenmark, Malin
    Uppsala Universitet.
    Ingelsson, Martin
    Uppsala Universitet.
    Blennow, Kaj
    Sahlgrenska University Hospital, University of Gothenburg.
    Zetterberg, Henrik
    Sahlgrenska University Hospital, University of Gothenburg; Department of Neurodegenerative Disease, UCL Institute of Neurology, London; UK Dementia Research Institute at UCL, London.
    Nellgård, Bengt
    Sahlgrenska University Hospital, University of Gothenburg.
    Brosseron, Frederic
    Universitätsklinikum, Bonn; German Center for Neurodegenerative Diseases (DZNE), Bonn.
    Heneka, Michael
    Universitätsklinikum, Bonn.
    Bosch, Beatriz
    University of Barcelona.
    Sanches-Valle, Raquel
    University of Barcelona.
    Månberg, Anna
    KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Svenningsson, Per
    Karolinska Institutet.
    Nilsson, Peter
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Multi-cohort protein profiling reveals higher levels of six brain-enriched proteins in Alzheimer’s disease patientsManuscript (preprint) (Other academic)
  • 16777.
    Bergström, Sofia
    et al.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Remnestål, Julia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Yousef, Jamil
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Olofsson, Jennie
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Markaki, Ioanna
    Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden.
    Carvalho, Stephanie
    Sorbonne Université Institut du Cerveau ‐ Paris Brain Institute ‐ ICM, Assistance‐Publique Hôpitaux de Paris INSERM CNRS Hôpital Pitié‐Salpêtrière Department of Neurology Centre d’Investigation Clinique Neurosciences Paris France.
    Corvol, Jean‐Christophe
    Sorbonne Université Institut du Cerveau ‐ Paris Brain Institute ‐ ICM, Assistance‐Publique Hôpitaux de Paris INSERM CNRS Hôpital Pitié‐Salpêtrière Department of Neurology Centre d’Investigation Clinique Neurosciences Paris France.
    Kultima, Kim
    Department of Medical Sciences Clinical Chemistry Uppsala University Uppsala Sweden.
    Kilander, Lena
    Department of Public Health and Caring Sciences Geriatrics Uppsala University Uppsala Sweden.
    Löwenmark, Malin
    Department of Public Health and Caring Sciences Geriatrics Uppsala University Uppsala Sweden.
    Ingelsson, Martin
    Department of Public Health and Caring Sciences Geriatrics Uppsala University Uppsala Sweden.
    Blennow, Kaj
    Department of Psychiatry and Neurochemistry Institute of Neuroscience and Physiology The Sahlgrenska Academy University of Gothenburg;Clinical Neurochemistry Laboratory Sahlgrenska University Hospital Mölndal Sweden.
    Zetterberg, Henrik
    Department of Psychiatry and Neurochemistry Institute of Neuroscience and Physiology The Sahlgrenska Academy University of Gothenburg;Clinical Neurochemistry Laboratory Sahlgrenska University Hospital Mölndal Sweden;Department of Neurodegenerative Disease UCL Institute of Neurology London UK;UK Dementia Research Institute at UCL London UK.
    Nellgård, Bengt
    Anesthesiology and Intensive Care Medicine Sahlgrenska University Hospital Mölndal Sweden;Department of Anesthesiology and Intensive Care Medicine Institute of Clinical Sciences The Sahlgrenska Academy University of Gothenburg.
    Brosseron, Frederic
    Universitätsklinikum Bonn Germany;German Center for Neurodegenerative Diseases (DZNE) Bonn Germany.
    Heneka, Michael T.
    Universitätsklinikum Bonn Germany.
    Bosch, Beatriz
    Alzheimer’s and other cognitive disorders Unit. Service of Neurology Hospital Clínic de Barcelona Institut d'Investigació Biomèdica August Pi i Sunyer University of Barcelona Barcelona Spain.
    Sanchez‐Valle, Raquel
    Alzheimer’s and other cognitive disorders Unit. Service of Neurology Hospital Clínic de Barcelona Institut d'Investigació Biomèdica August Pi i Sunyer University of Barcelona Barcelona Spain.
    Månberg, Anna
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Svenningsson, Per
    Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden.
    Nilsson, Peter
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Multi‐cohort profiling reveals elevated CSF levels of brain‐enriched proteins in Alzheimer’s disease2021In: Annals of Clinical and Translational Neurology, E-ISSN 2328-9503, Vol. 8, no 7, p. 1456-1470Article in journal (Refereed)
    Abstract [en]

    Objective: Decreased amyloid beta (Ab) 42 together with increased tau and phospho-tau in cerebrospinal fluid (CSF) is indicative of Alzheimer’s disease (AD). However, the molecular pathophysiology underlying the slowly progressive cognitive decline observed in AD is not fully understood and it is not known what other CSF biomarkers may be altered in early disease stages. Methods: We utilized an antibody-based suspension bead array to analyze levels of 216 proteins in CSF from AD patients, patients with mild cognitive impairment (MCI), and controls from two independent cohorts collected within the AETIONOMY consortium. Two additional cohorts from Sweden were used for biological verification. Results: Six proteins, amphiphysin (AMPH), aquaporin 4 (AQP4), cAMP-regulated phosphoprotein 21 (ARPP21), growth-associated protein 43 (GAP43), neurofilament medium polypeptide (NEFM), and synuclein beta (SNCB) were found at increased levels in CSF from AD patients compared with controls. Next, we used CSF levels of Ab42 and tau for the stratification of the MCI patients and observed increased levels of AMPH, AQP4, ARPP21, GAP43, and SNCB in the MCI subgroups with abnormal tau levels compared with controls. Further characterization revealed strong to moderate correlations between these five proteins and tau concentrations. Interpretation: In conclusion, we report six extensively replicated candidate biomarkers with the potential to reflect disease development. Continued evaluation of these proteins will determine to what extent they can aid in the discrimination of MCI patients with and without an underlying AD etiology, and if they have the potential to contribute to a better understanding of the AD continuum.

  • 16778.
    Bergström, Thobias
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Bikazzan, Alex
    KTH, School of Computer Science and Communication (CSC).
    Gamification – Spelmekaniker som motivationsfaktor hos studenter.2011Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Games have always been a part of culture and society. They are deeply ingrained in the human nature, yet they seldom receive much of our attention in the academic world. As computer games have matured in recent years, so has the interest of applying their techniques in other environments.

    Never before have so many people played games for so many hours. Why is that? Modern games have a unique quality of capturing ones attention and keeping it for long stretches of time. Our goal has been to harness the techniques whereby this is accomplished in games to use in motivating students instead.

    By building a prototype and gathering data from users of it we have managed to pinpoint a few critical properties needed to be able to achieve the “gamification” of school. In the process we have also gathered some guidelines for the development of such an application.

    This report concludes that, although it might be possible, it is very hard to make this work in reality. One would need to reform the structure of the Swedish school-system in order to successfully implement gamification in such a way as we have tried here.

  • 16779.
    Bergström, Viktor
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Korrosion under värmeisolering av komponenter inom processindustri: Analys av skadeexempel2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 16780.
    Bergström, William
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Haas, Florian
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Supply Chain Traceability: A framework for a future traceability system in the electrification industry2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Society's demand for supply chain traceability is increasing. The need for traceability has been prevalent in food and pharmaceuticals for quite some time. However, the demand for traceability is now spreading to other industries, for instance, the electrification industry. This thesis aims to establish a traceability system framework for an electrification company that strives to have sustainable products of a specific origin. The framework must satisfy both the company's mission and existing legislation. Furthermore, both sustainability and having a supply chain of a specific origin is something that the food and pharmaceutical industries have used traceability systems to verify. The electrification industry could implement traceability systems similar to those in other industries. Therefore, the suggested traceability system framework is based on a literature review from other industries. The framework is also based on stakeholder analysis and a value tree analysis. The result is a framework presented through data flow and entity-relationship models. The suggested traceability system tracks data from customer RFQ and the most upstream sub-supplier to the end-of-life of the product. The result is a system that can verify the company's sustainability, quality, and the specific origin of the supply chain while complying with existing legislation.

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  • 16781.
    BERGSTRÖM, WILLIAM
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    TEMPELMAN, LUDVIG
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Integrerad produktutveckling i praktiken: Hur graden av förnyelse påverkar struktureringen av projekt2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Konkurrensen i dagens företagsvärld kräver att företag verkligen utmärker sig från mängden. Huvudsakligen finner bolag möjligheten att överträffa sina konkurrenter genom differentiering eller kostnadsminimering. Idag har båda dessa begrepp en klar koppling till produktutveckling. Men för att kunna differentiera sig så måste bolag skapa något nytt, de behöver alltså produktutveckla. För att utveckla produkter på ett effektivt och målinriktat sätt använder sig företag av integrerad produktutveckling (IPU). Integrerad produktutveckling syftar till att involvera olika kompetenser inom bolaget för att styra produktutvecklingen på ett sätt som är bäst lämpad för marknaden. Exempelvis involveras försäljare i produktutvecklingen för att säkerställa att det som utvecklas kan säljas och leverera värde till kunden. IPU syftar till att både främja effektivitet och innovation, genom att alla relevanta personer involveras i ett tidigt skede för att inte upptäcka problem sent i produktutvecklingsprocessen. Men det finns även kritik mot IPU som menar att involvering av för mycket personer bidrar till ökade kompromisser, vilket kan hämma innovationen. Ytterligare kritik mot IPU menar att bolags administrativa kostnader blir onödigt stora av att involvera för många medarbetare. Således står IPU i viss konflikt mellan kostnadsminimering och innovation.  Denna studie vill bidra med kunskap kring hur företag kan anpassa det integrerade arbetet efter projektets uppgift och omfattning. Eftersom ett kunskapsbehov i detta område kan vara anledningen till att IPU fortfarande ifrågasätts och inte är felfritt. Således definierades parametern  Graden av förnyelse som syftar till att beskriva hur stor andel av produktutvecklingsarbetet innebär innovation. Studien syftar till att undersöka hur graden av förnyelse påverkar hur projekt utförs i praktiken.

    Detta studerades med hjälp av semistrukturerade intervjuer av R&D-medarbetare hos två stora teknikbolag. Empirin från dessa studier indikerar att bolag tar hänsyn till graden av förnyelse i sitt produktutvecklingsarbete. Vid projekt med hög grad av förnyelse, så kallade utvecklingsprojekt, så använde sig båda bolagen av en stage-gateprocess som kännetecknas av integrerade kontrollmekanismer och beslutsfattande. Projekt med hög grad av förnyelse tenderar även att vara mer centraliserat styrda. Däremot behandlade bolagen projekt med låg grad av förnyelse, ändringsprojekt, helt annorlunda. Dessa projekt var inte alls lika strukturerade och arbetssättet var inte lika integrerat, eftersom man inte ville ha onödiga administrationskostnader. För ändringsprojekten var kontrollbehovet inte alls lika stort och därför var styrningen av dessa projekt mer decentraliserad. Sammanfattningsvis kan det konstateras att graden av förnyelsen påverkar hur bolag bedriver projektarbete i praktiken. Dock kan resultatet kritiseras sett till om graden av förnyelse verkligen är det mest relevanta begreppet för att förklara varför bolag anpassar sin IPU. Exempelvis skulle ändringen i kundupplevelse kunna vara en mer relevant parameter

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  • 16782.
    BERGSTRÖM, WILLIAM
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    TEMPELMAN, LUDVIG
    KTH, School of Industrial Engineering and Management (ITM).
    Integrerad produktutveckling i praktiken Hur graden av förnyelse påverkar struktureringen av projekt2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Konkurrensen i dagens företagsvärld kräver att företag verkligen utmärker sig från mängden. Huvudsakligen finner bolag möjligheten att överträffa sina konkurrenter genom differentiering eller kostnadsminimering. Idag har båda dessa begrepp en klar koppling till produktutveckling. Men för att kunna differentiera sig så måste bolag skapa något nytt, de behöver alltså produktutveckla. För att utveckla produkter på ett effektivt och målinriktat sätt använder sig företag av integrerad produktutveckling (IPU). Integrerad produktutveckling syftar till att involvera olika kompetenser inom bolaget för att styra produktutvecklingen på ett sätt som är bäst lämpad för marknaden. Exempelvis involveras försäljare i produktutvecklingen för att säkerställa att det som utvecklas kan säljas och leverera värde till kunden. IPU syftar till att både främja effektivitet och innovation, genom att alla relevanta personer involveras i ett tidigt skede för att inte upptäcka problem sent i produktutvecklingsprocessen. Men det finns även kritik mot IPU som menar att involvering av för mycket personer bidrar till ökade kompromisser, vilket kan hämma innovationen. Ytterligare kritik mot IPU menar att bolags administrativa kostnader blir onödigt stora av att involvera för många medarbetare. Således står IPU i viss konflikt mellan kostnadsminimering och innovation. Denna studie vill bidra med kunskap kring hur företag kan anpassa det integrerade arbetet efter projektets uppgift och omfattning. Eftersom ett kunskapsbehov i detta område kan vara anledningen till att IPU fortfarande ifrågasätts och inte är felfritt. Således definierades parametern Graden av förnyelse som syftar till att beskriva hur stor andel av produktutvecklingsarbetet innebär innovation. Studien syftar till att undersöka hur graden av förnyelse påverkar hur projekt utförs i praktiken

    Detta studerades med hjälp av semistrukturerade intervjuer av R&D-medarbetare hos två stora teknikbolag. Empirin från dessa studier indikerar att bolag tar hänsyn till graden av förnyelse i sitt produktutvecklingsarbete. Vid projekt med hög grad av förnyelse, så kallade utvecklingsprojekt, så använde sig båda bolagen av en stage-gateprocess som kännetecknas av integrerade kontrollmekanismer och beslutsfattande. Projekt med hög grad av förnyelse tenderar även att vara mer centraliserat styrda. Däremot behandlade bolagen projekt med låg grad av förnyelse, ändringsprojekt, helt annorlunda. Dessa projekt var inte alls lika strukturerade och arbetssättet var inte lika integrerat, eftersom man inte ville ha onödiga administrationskostnader. För ändringsprojekten var kontrollbehovet inte alls lika stort och därför var styrningen av dessa projekt mer decentraliserad. Sammanfattningsvis kan det konstateras att graden av förnyelsen påverkar hur bolag bedriver projektarbete i praktiken. Dock kan resultatet kritiseras sett till om graden av förnyelse verkligen är det mest relevanta begreppet för att förklara varför bolag anpassar sin IPU. Exempelvis skulle ändringen i kundupplevelse kunna vara en mer relevant parameter.

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  • 16783. Bergström, Yngve
    et al.
    Granbom, Ylva
    A dislocation model for the stress-strain behavior of dual phase steels2008In: IDDRG 2008 International Conference, 2008Conference paper (Refereed)
    Abstract [en]

    The Bergström dislocation model is used to study the influence of coiling temperature after hot rolling on the mechanical properties of the cold rolled SSAB-grade Docol 800DP. Further, the anisotropy-effect for this type of steel, caused for instance by banding, is investigated. The physical dislocation model is based on the assumption that the work hardening behaviour is controlled by the creation, the immobilisation and the remobilisation of dislocations and it is demonstrated that all these processes are strongly influenced by the amount of hard martensite particles in DP-steels. The true strain to necking is a widely used tool for estimating the stretch formability of DP-steels. A detailed discussion regarding the influence of for instance friction stress, rate of dislocation remobilisation and mean free path of dislocation motion is presented. It is also indicated that the best stretch formability of DP-steel is obtained by minimising the quotient between the rate of work hardening at smaller strains with that at larger strains, close to the strain at necking.

  • 16784. Bergström, Yngve
    et al.
    Granbom, Ylva
    Product Development/Materials Research, Borlänge, Sweden.
    Sterkenburg, Dirk
    A dislocation based theory for the deformation hardening behavior of DP-steels: Impact of martensite content and ferrite grain size2010In: Journal of Metallurgy, ISSN 1687-9465, E-ISSN 1687-9473, Vol. 2010, no 647198Article in journal (Refereed)
    Abstract [en]

    A dislocation model, accurately describing the uniaxial plastic stress-strain behavior of dual phase (DP) steels, is proposed and the impact of martensite content and ferrite grain size in four commercially produced DP-steels is analyzed. It is assumed that the plastic deformation process is localized to the ferrite. This is taken into account by introducing a non-homogeneity parameter, f(ε), that specifies the volume fraction of ferrite taking active part in the plastic deformation process. It is found that the larger the martensite content the smaller the initial volume fraction of active ferrite which yields a higher initial deformation hardening rate. This explains the high energy absorbing capacity of DP-steels with high volume fractions of martensite. Further, the effect of ferrite grain size strengthening in DP-steels is important. The flow stress grain size sensitivity for DP-steels is observed to be 7 times larger than that for single phase ferrite.

  • 16785.
    Bergsåker, B. Henric M.
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics. EUROfusion Consortium, Culham Science Centre, JET, Abingdon, United Kingdom.
    Bykov, Igor
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics. EUROfusion Consortium, Culham Science Centre, JET, Abingdon, United Kingdom.
    Zhou, Yushan
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics. EUROfusion Consortium, Culham Science Centre, JET, Abingdon, United Kingdom.
    Petersson, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics. EUROfusion Consortium, Culham Science Centre, JET, Abingdon, United Kingdom.
    Possnert, G.
    Likonen, J.
    Pettersson, J.
    Koivuranta, S.
    Widdowson, A. M.
    Deep deuterium retention and Be/W mixing at tungsten coated surfaces in the JET divertor2016In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T167, article id 014061Article in journal (Refereed)
    Abstract [en]

    Surface samples from a full poloidal set of divertor tiles exposed in JET through operations 2010-2012 with ITER-like wall have been investigated using SEM, SIMS, ICP-AES analysis and micro beam nuclear reaction analysis (μ-NRA). Deposition of Be and retention of D is microscopically inhomogeneous. With careful overlaying of μ-NRA elemental maps with SEM images, it is possible to separate surface roughness effects from depth profiles at microscopically flat surface regions, without pits. With (3He, p) μ-NRA at 3-5 MeV beam energy the accessible depth for D analysis in W is about 9 μm, sufficient to access the W/Mo and Mo/W interfaces in the coatings and beyond, while for Be in W it is about 6 μm. In these conditions, at all plasma wetted surfaces, D was found throughout the whole accessible depth at concentrations in the range 0.2-0.7 at% in W. Deuterium was found to be preferentially trapped at the W/Mo and Mo/W interfaces. Comparison is made with SIMS profiling, which also shows significant D trapping at the W/Mo interface. Mixing of Be and W occurs mainly in deposited layers.

  • 16786.
    Bergsåker, Claudia
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Impact of transformer core size on the reactive power requirement of power transformers due to GIC2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Geomagnetically induced currents (GIC) are a natural phenomenon which arises due to solar

    storms. During a solar storm, large amounts of magnetized plasma are ejected from the surface

    of the sun. When this plasma reaches earth, it causes fluctuations in the geomagnetic field. Such

     fluctuations may induce DC over-currents in long transmission lines. These currents affect the

    transmission system several dierent ways; In particular high voltage transformers are sensitive to

    GIC. When the over-current flows through the transformer windings the reactive power absorption

    of the transformer increases, which may lead to voltage instability in the power system. For this

    project, the main issue has been to determine whether or not an increase in the size of the transformer

    core leads to the reactive power absorption being less sensitive to GIC. In order to investigate

    this issue a recently developed transformer model has been used; the Hybrid transformer model.

    This model combines the principle of duality with a matrix representation of the transformer. The

    Hybrid transformer model, which has recently been implemented in the power system simulations

    software PSCAD, has been used to simulate GIC events in transformers of varying core sizes. The

    results from these simulations indicate that a larger transformer core is associated with a smaller

    increase in reactive power absorption during a GIC event. It is also clear that the reactive power

    absorption as a function of GIC magnitude is a non-linear function when the Hybrid transformer

    model is applied. This function has previously been considered a linear function.

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  • 16787.
    Bergsåker, H
    et al.
    KTH, Superseded Departments (pre-2005), Alfvén Laboratory.
    Larsson, D
    KTH, Superseded Departments (pre-2005), Alfvén Laboratory.
    Brunsell, P
    KTH, Superseded Departments (pre-2005), Alfvén Laboratory.
    Möller, A
    KTH, Superseded Departments (pre-2005), Alfvén Laboratory.
    Tramontin, L
    Wall conditioning and particle control in Extrap T21997In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 241-243, p. 993-997Article in journal (Refereed)
  • 16788.
    Bergsåker, Henric
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Egde profiles and limiter tests in Extrap T21999In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 266-269, p. 777-782Article in journal (Refereed)
  • 16789.
    Bergsåker, Henric
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Hydrogen recycling in graphite at higher fluxes1999In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 266-269, p. 856-851Article in journal (Refereed)
  • 16790.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Bykov, Igor
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Frassinetti, Lorenzo
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Garcia-Carrasco, Alvaro
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Hellsten, Torbjörn
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Johnson, Thomas
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Menmuir, Sheena
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Petersson, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Rachlew, Elisabeth
    KTH, School of Engineering Sciences (SCI), Physics.
    Ratynskaia, Svetlana
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Rubel, Marek
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Stefanikova, Estera
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Ström, Petter
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Tholerus, Emmi
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Tolias, Panagiotis
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Olivares, Pablo Vallejos
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Weckmann, Armin
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Zhou, Yushun
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Zychor, I.
    et al.,
    Assessment of the strength of kinetic effects of parallel electron transport in the SOL and divertor of JET high radiative H-mode plasmas using EDGE2D-EIRENE and KIPP codes2018In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 60, no 11, article id 115011Article in journal (Refereed)
    Abstract [en]

    The kinetic code for plasma periphery (KIPP) was used to assess the importance of the kinetic effects of parallel electron transport in the scrape-off layer (SOL) and divertor of JET high radiative H-mode inter-ELM plasma conditions with the ITER-like wall and strong nitrogen (N-2) injection. Plasma parameter profiles along a magnetic field from one of the EDGE2D-EIRENE simulation cases were used as an input for KIPP runs. Profiles were maintained by particle and power sources. KIPP generated electron distribution functions, f(e), parallel power fluxes, electron-ion thermoforces, Debye sheath potential drops and electron sheath transmission factors at divertor targets. For heat fluxes in the main SOL, KIPP results showed deviations from classical (e.g. Braginskii) fluxes by factors typically of similar to 1.5, sometimes up to 2, with the flux limiting for more upstream positions and flux enhancement near entrances to the divertor. In the divertor, at the same time, for radial positions closer to the separatrix, very large heat flux enhancement factors of up to ten or even higher, indicative of a strong nonlocal heat transport, were found at the outer target, with heat power flux density exhibiting bump-on-tail features at high energies. Under such extreme conditions, however, contributions of conductive power fluxes to total power fluxes were strongly reduced, with convective power fluxes becoming comparable, or sometimes exceeding, conductive power fluxes. Electron-ion thermoforce, on the other hand, which is known to be determined mostly by thermal and subthermal electrons, was found to be in good agreement with Braginskii formulas, including the Z(eff) dependence. Overall, KIPP results indicate, at least for the plasma conditions used in this modelling, a sizable, but not dominant, effect of kinetics on parallel electron transport.

  • 16791.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Bykov, Igor
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Petersson, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Possnert, G.
    Likonen, J.
    Koivuranta, S.
    Coad, J. P.
    Widdowson, A. M.
    Microstructure and inhomogeneous fuel trapping at divertor surfaces in the JET tokamak2014In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 332, p. 266-270Article in journal (Refereed)
    Abstract [en]

    The plasma deposited layers at divertor surfaces in the JET tokamak with carbon wall have been studied post mortem, using micro ion beam analysis (mu-IBA) methods, optical microscopy and scanning electron microscopy (SEM). The layers were formed during plasma operations over different periods through 1998-2009. They frequently have a columnar structure. For mu-IBA a 3 MeV He-3 beam was used, focused to about 5-15 mu m size. Nuclear reaction analysis was used to measure D, Be and C. Elemental mapping was carried out both at the original surface and on polished layer cross sections. Trapped deuterium is predominantly found in remote areas on the horizontal bottom divertor tiles and in regions with locally enhanced deuterium concentration on the vertical tiles. Pockets with enhanced deuterium concentration are found in the carbon fibre composite (CFC) substrate. Areas with dimensions of about 100 mu m with enhanced deuterium concentration are also found inside the deposited layers. The inhomogeneous fuel trapping is tentatively explained with co-deposition in partly protected pits in the substrate and by incorporation of dust particles in the growing layers.

  • 16792.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Bykov, Igor
    Zhou, Yushan
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Petersson, Per
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Fusion Plasma Physics.
    Possnert, G
    Likonen, J
    Pettersson, J
    Koivuranta, S
    Widdowson, A.M.
    contributors, JET
    Deep deuterium retention and Be/W mixingat tungsten coated surfaces in the JETdivertor2016In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896Article in journal (Refereed)
    Abstract [en]

    Surface samples from a full poloidal set of divertor tiles exposed in JET through operations2010–2012 with ITER-like wall have been investigated using SEM, SIMS, ICP-AES analysisand micro beam nuclear reaction analysis (μ-NRA). Deposition of Be and retention of D ismicroscopically inhomogeneous. With careful overlaying of μ-NRA elemental maps with SEMimages, it is possible to separate surface roughness effects from depth profiles at microscopicallyflat surface regions, without pits. With (3He, p) μ-NRA at 3–5 MeV beam energy the accessibledepth for D analysis in W is about 9 μm, sufficient to access the W/Mo and Mo/W interfaces inthe coatings and beyond, while for Be in W it is about 6 μm. In these conditions, at all plasmawetted surfaces, D was found throughout the whole accessible depth at concentrations in therange 0.2–0.7 at% in W. Deuterium was found to be preferentially trapped at the W/Mo andMo/W interfaces. Comparison is made with SIMS profiling, which also shows significant Dtrapping at the W/Mo interface. Mixing of Be and W occurs mainly in deposited layers.

  • 16793.
    Bergsåker, Henric
    et al.
    KTH, School of Engineering Sciences (SCI), Physics, Atomic and Molecular Physics.
    Emmoth, Birger
    KTH, School of Engineering Sciences (SCI), Physics, Atomic and Molecular Physics.
    Ilyinsky, Lev
    KTH, School of Engineering Sciences (SCI), Physics, Atomic and Molecular Physics.
    In-situ ion beam analysis and dynamic studies of deuterium retention in graphite exposed to a high flux magnetron plasma1997In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 241-243, p. 1022-1025Article in journal (Refereed)
  • 16794.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Emmoth, Birger
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Petersson, P.
    Possnert, Göran
    Coad, J. P.
    Likonen, J.
    Renvall, T.
    Nuclear reaction analysis with ion microbeam of cross sections of surface layers deposited in a tokamak divertor2007In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 362, no 03-feb, p. 215-221Article in journal (Refereed)
    Abstract [en]

    Ion micro beam analysis has been applied to the investigation of plasma deposited layers covering the divertor tiles in the JET tokamak. Since the layers are about 100 mu m thick they are too thick to be completely investigated by ordinary ion beam analysis. Cross sections of the layers were prepared by cutting and polishing. Elemental depth profiles were determined from the two dimensional images that could be derived by nuclear reaction analysis and resonant backscattering spectrometry, using ion beams focused to a few mu m spot size. A combination of analysis methods are shown, which allow measurements of the concentration profiles of carbon, beryllium, deuterium, oxygen and stainless steel components at levels of a few percent, with an accuracy better than 10%.

  • 16795.
    Bergsåker, Henric
    et al.
    KTH, Superseded Departments (pre-2005), Alfvén Laboratory.
    Ilyinsky, L.
    Portnoff, G.
    Ion beam analysis of sputter-deposited gold films for quartz resonators2000In: Surface and Interface Analysis, ISSN 0142-2421, E-ISSN 1096-9918, Vol. 30, no 1, p. 620-622Article in journal (Refereed)
    Abstract [en]

    Sputter deposition using a focused ion beam has been investigated as an alternative to magnetron sputtering for the deposition of thin-film gold electrodes onto quartz resonators. One potential concern is the inclusion of argon in the growing film when argon ions are used for sputtering. Argon retention in sputter-deposited gold films using an 11.5 keV argon ion beam was investigated with Rutherford backscattering spectrometry and it was found that in layers deposited at close to normal ejection angles the argon trapping was at the level of less than or equal to 1 at,%, similar to magnetron-deposited layers, whereas argon incorporation increased with the ejection angle up to several per cent at large angles.

  • 16796.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Menmuir, Sheena
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Rachlew, Elisabeth
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Brunsell, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Frassinetti, Lorenzo
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Drake, James R.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Metal impurity fluxes and plasma-surface interactions in EXTRAP T2R2008In: PROCEEDINGS OF THE 17TH INTERNATIONAL VACUUM CONGRESS/13TH INTERNATIONAL CONFERENCE ON SURFACE SCIENCE/INTERNATIONAL CONFERENCE ON NANOSCIENCE AND TECHNOLOGY, 2008, Vol. 100Conference paper (Refereed)
    Abstract [en]

    The EXTRAP T2R is a large aspect ratio Reversed Field Pinch device. The main focus of interest for the experiments is the active feedback control of resistive wall modes [1]. With feedback it has been possible to prolong plasma discharges in T2R from about 20 ms to nearly 100 ms. In a series of experiments in T2R, in H- and D- plasmas with and without feedback, quantitative spectroscopy and passive collector probes have been used to study the flux of metal impurities. Time resolved spectroscopic measurements of Cr and Mo lines showed large metal release towards discharge termination without feedback. Discharge integrated fluxes of Cr, Fe, Ni and Mo were also measured with collector probes at wall position. Reasonable quantitative agreement was found between the spectroscopic and collector probe measurements. The roles of sputtering, thermal evaporation and arcing in impurity production are evaluated based on the composition of the measured impurity flux.

  • 16797.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Petersson, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Bykov, Igor
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Possnert, G.
    Likonen, J.
    Koivuranta, S.
    Coad, J. P.
    Widdowson, A. M.
    Microanalysis of deposited layers in the divertor of JET following operations with carbon wall2013In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 438, no Suppl., p. S668-S672Article in journal (Refereed)
    Abstract [en]

    Elemental mapping of cross sections of deposited layers on inboard tiles in the JET divertor after exposure to plasma operations with carbon wall are presented. The study was made using microbeam ion beam analysis methods in combination with optical microscopy and SEM. The surfaces had been exposed to plasma through different periods of operation (1998-2007, 2007-2009 and 1998-2009). The texture and composition of the layers are non-uniform. The physical structures include columnar, lamellar and disordered globular appearances. The distribution of trapped deuterium was frequently found to be lamellar, with well-defined sub layers with higher deuterium concentration. However, 3D regions with dimensions of about 100 μm with enhanced deuterium content were also found, both at the layer surfaces and in the layer cross sections. The distributions of beryllium and Inconel components were lamellar but did not otherwise show large non-uniformity on the same scale length as the deuterium.

  • 16798.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Possnert, G.
    Bykov, Igor
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Heinola, K.
    Petersson, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Miettunen, J.
    Widdowson, A.
    Riccardo, V.
    Nunes, I.
    Stamp, M.
    Brezinsek, S.
    Groth, M.
    Kurki-Suonio, T.
    Likonen, J.
    Coad, J. P.
    Borodin, D.
    Kirschner, A.
    Schmid, K.
    Krieger, K.
    First results from the Be-10 marker experiment in JET with ITER-like wall2014In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 54, no 8, p. 082004-Article in journal (Refereed)
    Abstract [en]

    When the ITER-like wall was installed in JET, one of the 218 Be inner wall guard limiter tiles had been enriched with Be-10 as a bulk isotopic marker. During the shutdown in 2012-2013, a set of tiles were sampled nondestructively to collect material for accelerator mass spectroscopy measurements of Be-10 concentration. The letter shows how the marker experiment was set up, presents first results and compares them to preliminary predictions of marker redistribution, made with the ASCOT numerical code. Finally an outline is shown of what experimental data are likely to become available later and the possibilities for comparison with modelling using the WallDYN, ERO and ASCOT codes are discussed.

  • 16799.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Possnert, G.
    Bykov, Igor
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Heinola, K.
    Petersson, Per
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Miettunen, J.
    Widdowson, C.
    Riccardo, V.
    Nunes, I.
    Stamp, M.
    et al.,
    First results from10Be marker experiment in JET with ITER-like wallManuscript (preprint) (Other academic)
  • 16800.
    Bergsåker, Henric
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Ratynskaia, Svetlana
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Litnovsky, A.
    Ogata, Douglas
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Sahle, Wubeshet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Studies of mobile dust in scrape-off layer plasmas using silica aerogel collectors2011In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 415, no 1, p. S1089-S1093Article in journal (Refereed)
    Abstract [en]

    Dust capture with ultralow density silica aerogel collectors is a new method, which allows time resolved in situ capture of dust particles in the scrape-off layers of fusion devices, without substantially damaging the particles. Particle composition and morphology, particle flux densities and particle velocity distributions can be determined through appropriate analysis of the aerogel surfaces after exposure. The method has been applied in comparative studies of intrinsic dust in the TEXTOR tokamak and in the Extrap T2R reversed field pinch. The analysis methods have been mainly optical microscopy and SEM. The method is shown to be applicable in both devices and the results are tentatively compared between the two plasma devices, which are very different in terms of edge plasma conditions, time scale, geometry and wall materials.

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