oru.sePublications
Change search
Refine search result
123 101 - 116 of 116
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101. Ocklund, Johnny
    et al.
    Asnafi, Nader
    Volvo Car Corporation, Göteborg (and Olofström), Sweden .
    Hydromechanical forming of trunklid outer2002In: Information Technology, Global Environment and Sheet Metal Forming: Proceedings of the 22nd Biennial Congress, 2002Conference paper (Other academic)
  • 102.
    Pejryd, Lars
    et al.
    Örebro University, School of Science and Technology.
    Beno, Tomas
    University West, Trollhättan, Sweden.
    Carmignato, Simone
    University of Padova, Padova, Italy.
    Computed tomography as a tool for examining surface integrity in drilled holes in CFRP composites2014In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 13, p. 43-48Article in journal (Refereed)
    Abstract [en]

    In light weight structures the joining of composite materials and of composites to metals are key technologies. A manufacturing method associated with joining is the drilling of holes. The hole creation in CRFP through drilling is associated with several defects related to the process, both on the entry and exit sides of the hole and also with dimensional and surface roughness issues of the hole wall. The detection of damage due to the process is not trivial. Especially interesting is non-destructive methods.

    In this work X-ray computed tomography is used to determine defects due to drilling of holes in a CFRP composite using twist drills with different geometrical features at different drilling parameters. The results can be used to establish relationship between different geometrical features of drills in combination with cutting parameters and resulting surface integrity of holes.

  • 103.
    Pejryd, Lars
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Patrik
    Örebro University, School of Science and Technology.
    Hällgren, Sebastian
    Örebro University, School of Science and Technology.
    Kahlin, Magnus
    Linköping University, Linköping, Sweden.
    Non-destructive evaluation of internal defects in additive manufactured aluminium2016Conference paper (Refereed)
  • 104.
    Pervishko, Anastasiia A.
    et al.
    ITMO University, Saint Petersburg, Russia.
    Baglai, Mikhail I.
    ITMO University, Saint Petersburg, Russia; Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
    Eriksson, Olle
    Örebro University, School of Science and Technology. Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
    Yudin, Dmitry
    ITMO University, Saint Petersburg, Russia.
    Another view on Gilbert damping in two-dimensional ferromagnets2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 17148Article in journal (Refereed)
    Abstract [en]

    A keen interest towards technological implications of spin-orbit driven magnetization dynamics requests a proper theoretical description, especially in the context of a microscopic framework, to be developed. Indeed, magnetization dynamics is so far approached within Landau-Lifshitz-Gilbert equation which characterizes torques on magnetization on purely phenomenological grounds. Particularly, spin-orbit coupling does not respect spin conservation, leading thus to angular momentum transfer to lattice and damping as a result. This mechanism is accounted by the Gilbert damping torque which describes relaxation of the magnetization to equilibrium. In this study we work out a microscopic Kubo-Streda formula for the components of the Gilbert damping tensor and apply the elaborated formalism to a two-dimensional Rashba ferromagnet in the weak disorder limit. We show that an exact analytical expression corresponding to the Gilbert damping parameter manifests linear dependence on the scattering rate and retains the constant value up to room temperature when no vibrational degrees of freedom are present in the system. We argue that the methodology developed in this paper can be safely applied to bilayers made of non- and ferromagnetic metals, e.g., CoPt.

  • 105.
    Pritchard, Christopher D.
    et al.
    Massachusetts Institute of Technology, Cambridge MA, USA.
    Crafoord, Sven
    Örebro University Hospital, Örebro, Sweden.
    Andréasson, Sten
    Lund University Hospital, Lund, Sweden.
    Arnér, Karin M.
    Lund University Hospital, Lund, Sweden.
    O'Shea, Timothy M
    Massachusetts Institute of Technology, Cambridge MA, USA.
    Langer, Robert
    Massachusetts Institute of Technology, Cambridge MA, USA.
    Ghosh, Fredrik K.
    Lund University, Lund, Sweden.
    Evaluation of viscoelastic poly(ethylene glycol) sols as vitreous substitutes in an experimental vitrectomy model in rabbits2011In: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 7, no 3, p. 936-943Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to employ an experimental protocol for in vivo evaluation of sols of 5 wt.% poly(ethylene glycol) (PEG) in phosphate-buffered saline as artificial vitreous substitutes. A 20 gauge pars plana vitrectomy and posterior vitreous detachment were performed in the right eye of eight pigmented rabbits. Approximately 1 ml of the viscoelastic PEG sols was then injected into the vitreous space of six eyes. PEG with an average molecular weight of 300,000 and 400,000 g mol(-1) was used in two and four eyes, respectively. Two eyes received balanced salt solution and served as controls. Full-field electroretinography was carried out and intra-ocular pressure (IOP, palpation) measured pre- and post-operatively at regular intervals up to 41 days. The rabbits were killed and the eyes examined by retinal photography, gross macroscopic examination and histology. The viscoelastic sols were successfully injected and remained translucent throughout the post-operative period, with some inferior formation of precipitates. None of the eyes displayed IOP elevation post-operatively, but in three of the PEG sol injected eyes transient hypotony was noted. One eye sustained retinal detachment during surgery and another two in the post-operative period. ERG recordings confirmed preservation of retinal function in three out of four eyes injected with 400,000 g mol(-1) PEG. Histological examination revealed up-regulation of glial acidic fibrillary protein in Müller cells in PEG sol injected eyes, but normal overall morphology in eyes with attached retinas. The viscosity of the sol was not retained throughout the post-operative period, indicating the demand for polymer cross-linking to increase residence time. The results provide promising preliminary results on the use of PEG hydrogels as a vitreous substitute.

  • 106.
    Rahayem, Mohamed R.
    et al.
    Örebro University, School of Science and Technology.
    Kjellander, Johan A. P.
    Örebro University, School of Science and Technology.
    Quadric segmentation and fitting of data captured by a laser profile scanner mounted on an industrial robot2010In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 52, no 1-4, p. 155-169Article in journal (Refereed)
    Abstract [en]

    Applications like geometric reverse engineering, robot vision and automatic inspection require sets of points to be measured from the surfaces of objects and then processed by segmentation and fitting algorithms to establish shape parameters of interest. In industrial applications where speed, reliability and automatic operation is of interest a measuring system based on a laser profile scanner mounted on an industrial robot can be of interest. In earlier publications we have presented such a system and also a segmentation algorithm for planar surfaces using 2D profile data in combination with robot poses. Due to the data reduction offered by this approach the segmentation algorithm computes faster than algorithms based on 3D point sets alone. Encouraged by the results we have now developed a segmentation algorithm for two different quadric surfaces also based on 2D profiles in combination with robot poses. This paper presents the new algorithm together with test results and also an interesting observation that points to future work.

  • 107.
    Sadeghimeresht, Esmaeil
    et al.
    Department of Engineering Science, University West, Trollhättan, Sweden.
    Karimi, Paria
    Department of Engineering Science, University West, Trollhättan, Sweden.
    Zhang, Pimin
    Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Peng, Ru
    Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Andersson, Joel
    Department of Engineering Science, University West, Trollhättan, Sweden.
    Pejryd, Lars
    Örebro University, School of Science and Technology.
    Joshi, Shrikant
    Department of Engineering Science, University West, Trollhättan, Sweden.
    Isothermal Oxidation Behavior of EBM-Additive Manufactured Alloy 7182018In: Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications / [ed] Ott, E.; Liu, X.; Andersson, J.; Bi, Z.; Bockenstedt, K.; Dempster, I.; Groh, J.; Heck, K.; Jablonski, P.; Kaplan, M:, Nagahama, D.; Sudbrack, C, Springer, 2018, p. 219-240Conference paper (Refereed)
    Abstract [en]

    Oxidation of Alloy 718 manufactured by electron beam melting (EBM) process has been undertaken in ambient air at 650, 700, and 800 degrees C for up to 168 h. At 800 degrees C, a continuous external chromia oxide enriched in (Cr, Ti, Mn, Ni) and an internal oxide that was branched structure of alumina formed, whereas at 650 and 700 degrees C, a continuous, thin and protective chromia layer was detected. The oxidation kinetics of the exposed EBM Alloy 718 followed the parabolic rate law with an effective activation energy of similar to 248 +/- 22 kJ/mol in good agreement with values in the literature for conventionally processed chromia-forming Ni-based superalloys. The oxide scale formed on the surface perpendicular to the build direction was slightly thicker, and more adherent compared to the scale formed on the surface along the build direction, attributed to the varied grain texture in the two directions of the EBM-manufactured specimens. The increased oxygen diffusion and high Cr depletion found on the surface along the build direction were attributed to the fine grains and formation of vacancies/voids along this grain orientation.

  • 108. Schedin, Erik
    et al.
    Asnafi, Nader
    Swedish Institute for Metals Research, Stockholm, Sweden .
    Hammam, Tag
    A comparison between flexforming and conventional forming: A study of semi-industrial components and real production parts1996Report (Other academic)
  • 109.
    Schonhobel, A. M.
    et al.
    Univ Basque Country, BCMat, Sci Pk, E-48940 Leioa, Spain.;Univ Basque Country, UPV EHU, Dept Elect & Elect, Leioa 48940, Spain..
    Madugundo, R.
    Univ Basque Country, BCMat, Sci Pk, E-48940 Leioa, Spain..
    Vekilova, O. Yu
    Uppsala Univ, Dept Phys & Astron, Box 516, S-75121 Uppsala, Sweden..
    Eriksson, O.
    Uppsala Univ, Dept Phys & Astron, Box 516, S-75121 Uppsala, Sweden.;Orebro Univ, Sch Sci & Technol, SE-70182 Orebro, Sweden..
    Herper, H. C.
    Uppsala Univ, Dept Phys & Astron, Box 516, S-75121 Uppsala, Sweden..
    Barandiaran, J. M.
    Univ Basque Country, BCMat, Sci Pk, E-48940 Leioa, Spain.;Univ Basque Country, UPV EHU, Dept Elect & Elect, Leioa 48940, Spain..
    Hadjipanayis, G. C.
    Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA..
    Intrinsic magnetic properties of SmFe12-xVx alloys with reduced V-concentration2019In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 786, p. 969-974Article in journal (Refereed)
    Abstract [en]

    In this work, we present experimental and theoretical results on SmFe12-xVx (x = 0.5 - 2.0) alloys with the ThMn12 (1:12) structure as possible candidates for rare earth-lean permanent magnets. The compound with x = 2 has been previously reported to have a Curie temperature of 330 degrees C, saturation magnetization of about 80 Am-2/kg, and anisotropy field around 9 T. We have synthesized the SmFe11V compound with a nearly pure 1:12 phase; the x = 0.5 compound couldn't be synthesized. The relative stability of the x = 1, 2 compounds was addressed theoretically by enthalpy calculations from first principles. The newly synthesized SmFe11V compound has a Curie temperature of 361 degrees C and saturation magnetization of 115 Am-2/kg (1.12 T). The anisotropy field has been obtained in magnetically-oriented fine powders, and is around 11 T. These parameters make SmFe11V a good candidate for a new kind of high energy, rare earth-lean permanent magnets.

  • 110.
    Shirinyan, Albert A.
    et al.
    ITMO University, Saint-Petersburg, Russian Federation.
    Kozin, Valerii K.
    ITMO University, Saint-Petersburg, Russian Federation; Science Institute, University of Iceland, Reykjavik, Iceland.
    Hellsvik, Johan
    Nordita, Stockholm, Sweden; Department of Physics, KTH Royal Institute of Technology, Stockholm, Sweden.
    Pereiro, Manuel
    Department of Physics and Astronomy, Materials Theory Division, Uppsala University, Uppsala, Sweden.
    Eriksson, Olle
    Örebro University, School of Science and Technology. Department of Physics and Astronomy, Materials Theory Division, Uppsala University, Uppsala, Sweden.
    Yudin, Dmitry
    Deep Quantum Labs, Skolkovo Institute of Science and Technology, Moscow, Russian Federation.
    Self-organizing maps as a method for detecting phase transitions and phase identification2019In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 99, no 4, article id 041108Article in journal (Refereed)
    Abstract [en]

    Originating from image recognition, methods of machine learning allow for effective feature extraction and dimensionality reduction in multidimensional datasets, thereby providing an extraordinary tool to deal with classical and quantum models in many-body physics. In this study, we employ a specific unsupervised machine learning technique-self-organizing maps-to create a low-dimensional representation of microscopic states, relevant for macroscopic phase identification and detecting phase transitions. We explore the properties of spin Hamiltonians of two archetype model systems: a two-dimensional Heisenberg ferromagnet and a three-dimensional crystal, Fe in the body-centered-cubic structure. The method of self-organizing maps, which is known to conserve connectivity of the initial dataset, is compared to the cumulant method theory and is shown to be as accurate while being computationally more efficient in determining a phase transition temperature. We argue that the method proposed here can be applied to explore a broad class of second-order phase-transition systems, not only magnetic systems but also, for example, order-disorder transitions in alloys.

  • 111.
    Strömberg, Niclas
    Örebro University, School of Science and Technology. Linköping University.
    Continuum Thermodynamics of Contact Friction and Wear1995Licentiate thesis, monograph (Other academic)
  • 112.
    Surreddi, K. B.
    et al.
    Materials Science, Dalarna University, Falun, Sweden.
    Oikonomou, C.
    Uddeholms AB, Hagfors, Sweden.
    Karlsson, Patrik
    Örebro University, School of Science and Technology.
    Olsson, M.
    Materials Science, Dalarna University, Falun, Sweden.
    Pejryd, Lars
    Örebro University, School of Science and Technology.
    In-situ micro-tensile testing of additive manufactured maraging steels in the SEM: Influence of build orientation, thickness and roughness on the resulting mechanical properties2018In: La Metallurgia Italiana, ISSN 0026-0843, no 3, p. 27-33Article in journal (Refereed)
    Abstract [en]

    Selective laser melting (SLM) is frequently used additive manufacturing technique capable of producing various complex parts including thin-wall sections. However the surface roughness is a limiting factor in thin sections produced by SLM process when strength is the main criterion. In this study, the influence of build orientation, thickness and roughness on the resulting mechanical properties of as-built test samples was investigated. Various thin sheets of EN 1.2709 maraging steel built in horizontal and vertical orientations produced by SLM were investigated using in-situ micro-tensile testing in a scanning electron microscope. The mechanical strength and deformation mechanisms were analyzed and explained based on thickness and build orientation. Increased ductility was observed in thicker samples as well as in the horizontal build samples. The results illustrate the potential of the in-situ test technique and aspects important to consider in design guidelines for thin AM structures.

  • 113.
    Thonig, Danny
    et al.
    Department of Physics and Astronomy, Materials Theory, Uppsala University, Uppsala, Sweden.
    Kvashnin, Yaroslav
    Department of Physics and Astronomy, Materials Theory, Uppsala University, Uppsala, Sweden.
    Eriksson, Olle
    Örebro University, School of Science and Technology. Department of Physics and Astronomy, Materials Theory, Uppsala University, Uppsala, Sweden.
    Pereiro, Manuel
    Department of Physics and Astronomy, Materials Theory, Uppsala University, Uppsala, Sweden.
    Nonlocal Gilbert damping tensor within the torque-torque correlation model2018In: Physical Review Materials, ISSN 2475-9953, Vol. 2, no 1, article id 013801Article in journal (Refereed)
    Abstract [en]

    An essential property of magnetic devices is the relaxation rate in magnetic switching, which depends strongly on the damping in the magnetization dynamics. It was recently measured that damping depends on the magnetic texture and, consequently, is a nonlocal quantity. The damping enters the Landau-Lifshitz-Gilbert equation as the phenomenological Gilbert damping parameter a, which does not, in a straightforward formulation, account for nonlocality. Efforts were spent recently to obtain Gilbert damping from first principles for magnons of wave vector q. However, to the best of our knowledge, there is no report about real-space nonlocal Gilbert damping aij. Here, a torque-torque correlation model based on a tight-binding approach is applied to the bulk elemental itinerant magnets and it predicts significant off-site Gilbert damping contributions, which could be also negative. Supported by atomistic magnetization dynamics simulations, we reveal the importance of the nonlocal Gilbert damping in atomistic magnetization dynamics. This study gives a deeper understanding of the dynamics of the magnetic moments and dissipation processes in real magnetic materials. Ways of manipulating nonlocal damping are explored, either by temperature, materials doping, or strain.

  • 114.
    Ullman, Andreas
    et al.
    Olofström School of Automotive Stamping, Olofström, Sweden .
    Kjellsson, Kenneth
    Volvo Cars Body Components, Olofström, Sweden.
    Johansson, Tuve
    Volvo Cars Body Components, Olofström, Sweden.
    Asnafi, Nader
    Volvo Cars Body Components, Olofström, Sweden.
    On laser hardening of trimming tools & dies2006In: Drawing the Things to Come: Trends and Advances in Sheet Metal Forming: Proceedings: IDDRG International Deep Drawing Research Group 2006 Conference / [ed] Abel D. Santos, A. Barata da Rocha, Inst. de Engenharia Mecânica e Gestão Industrial , 2006, p. 613-620Conference paper (Other academic)
    Abstract [en]

    In this study, the methods used to harden trim dies were at the focus. Laser surface-hardening was compared to induction- and through-hardening for small and medium-size series production. The sheet materials used were 1.2 mm thick uncoated Docol 600DP (DP600) and 1.95 mm thick uncoated Docol 600DL (DP600). The die materials tested were Fermo, Carmo and Sleipner.

    This investigation showed that the optimum laser-hardening parameters must be established for each trim die material. The trim die in laser-hardened Sleipner exhibits the smallest wear. The dimensional changes after laser hardening are very small. The burr height is very small, regardless of how the trim die is hardened. In this study, two sets of production trim dies were manufactured and set up. This production trim dies are used in the manufacture of V70 B-pillar Left and Right. Laser hardening resulted in a lead time reduction by 5 labour days. However, the Tool & Die unit at Volvo Cars estimates that the lead time reduction obtained with laser hardening should be around 10 days under normal conditions. The cost analysis conducted by the Tool & Die unit at Volvo Cars shows that the manufacturing costs are reduced by 6%, if laser-hardening is selected. These production trim dies are and will be monitored continuously. As this paper is being written, these dies have been subject to 270,000 strokes without exhibiting any problems.

  • 115.
    Vekilova, Olga Yu
    et al.
    Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
    Fayyazi, Bahar
    Materials Science, TU Darmstadt, Darmstadt, Germany.
    Skokov, Konstantin P.
    Materials Science, TU Darmstadt, Darmstadt, Germany.
    Gutfleisch, Oliver
    Materials Science, TU Darmstadt, Darmstadt, Germany.
    Echevarria-Bonet, Cristina
    BCMaterials, UPV/EHU Science Park, Leioa, Spain.
    Barandiarán, Jose Manuel
    BCMaterials, UPV/EHU Science Park, Leioa, Spain.
    Kovacs, Alexander
    Department for Integrated Sensor Systems, Danube University Krems, Wiener Neustadt, Austria.
    Fischbacher, Johann
    Department for Integrated Sensor Systems, Danube University Krems, Wiener Neustadt, Austria.
    Schrefl, Thomas
    Department for Integrated Sensor Systems, Danube University Krems, Wiener Neustadt, Austria.
    Eriksson, Olle
    Örebro University, School of Science and Technology. Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
    Herper, Heike C.
    Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
    Tuning the magnetocrystalline anisotropy of Fe3Sn by alloying2019In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 99, no 2, article id 024421Article in journal (Refereed)
    Abstract [en]

    The electronic structure, magnetic properties, and phase formation of hexagonal ferromagnetic Fe3Sn-based alloys have been studied from first principles and by experiment. The pristine Fe3Sn compound is known to fulfill all the requirements for a good permanent magnet, except for the magnetocrystalline anisotropy energy (MAE). The latter is large, but planar, i.e., the easy magnetization axis is not along the hexagonal c direction, whereas a good permanent magnet requires the MAE to be uniaxial. Here we consider Fe3Sn0.75M0.25, where M = Si, P, Ga, Ge, As, Se, In, Sb, Te, Pb, and Bi, and show how different dopants affect the MAE and can alter it from planar to uniaxial. The stability of the doped Fe3Sn phases is elucidated theoretically via the calculations of their formation enthalpies. A micromagnetic model is developed to estimate the energy density product (BH)(max) and coercive field mu H-0(c) of a potential magnet made of Fe3Sn0.75M0.25, the most promising candidate from theoretical studies. The phase stability and magnetic properties of the Fe3Sn compound doped with Sb and Mn have been checked experimentally on the samples synthesised using the reactive crucible melting technique as well as by solid state reaction. The Fe3Sn-Sb compound is found to be stable when alloyed with Mn. It is shown that even small structural changes, such as a change of the c/a ratio or volume, that can be induced by, e.g., alloying with Mn, can influence anisotropy and reverse it from planar to uniaxial and back.

  • 116.
    Överstam, Henrik
    et al.
    Örebro University, Department of Technology.
    Lundberg, Sven-Erik
    Örebro University, Department of Technology.
    A new approach to roll force and torque modelling in wire rod and bar mills2008In: Der Kalibreur, ISSN 0022-796X, Vol. 69, p. 61-72Article in journal (Refereed)
123 101 - 116 of 116
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf