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  • 1.
    Aaboen, Lise
    et al.
    Norwegian University of Science and Technology .
    La Rocca, Antonella
    BI Norwegian Business School.
    Lind, Frida
    Chalmers University of Technology.
    Perna, Andrea
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management. Universita' Politecnica delle Marche.
    Shih, Tommy
    Starting up in Business Networks: Why relationships matter in entrepreneurship2016 (ed. 1st)Book (Refereed)
  • 2.
    Aakash, förnamn
    et al.
    Department of Electronics and Communication Engg., Birla Institute of Technology.
    Nordblad, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Mohan, Rajendra
    Department of Physics, National Institute of Technology Patna.
    Mukherjee, Samrat
    Department of Physics, National Institute of Technology Patna.
    Structural, magnetic and hyperfine characterizations of nanocrystalline Zn-Cd doped nickel ferrites2017In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 441, p. 710-717Article in journal (Refereed)
    Abstract [en]

    In our present work, we have synthesized a series of Cd-Zn doped nickel ferrite ((Cd-0.5 Zn-x(x)) Ni0(.5)Fe(2)O(4); x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) through standard chemical co-precipitation method to study the influence of diamagnetic ions (Cd, Zn) on the magnetic properties of ferrites. XRD and Raman spectroscopy were employed for the structural characterizations. The refinement of the X-ray diffractogram data augmented by the Williamson-Hall plots showed the presence of Cd2+ vacancies and a strained crystal structure. The vibrational spectroscopy indicated the presence of lower space-group symmetry and a distorted crystal structure. Magnetic measurements showed the samples possessed low magnetic anisotropy along with a canted spin structure. The Mossbauer measurements confirmed the cation distribution and gave evidence of super transferred hyperfine interactions arising due to canted spin structure of the system.

  • 3.
    Abad, Manuel David
    et al.
    Instituto de Ciencia de Materiales de Sevilla, ICMS (CSIC-US), Spanien.
    Sanjines, Rosendo
    Ecole Polytechnique Federale de Lausanne, IPMC-SB, Lausanne, Schweiz.
    Endrino, Jose Luis
    Instituto de Ciencia de Materiales de Madrid, ICMM (CSIC), Spanien.
    Gago, Raul
    Instituto de Ciencia de Materiales de Madrid, ICMM (CSIC), Spanien.
    Andersson, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Sanchez-Lopez, Juan Carlos
    Instituto de Ciencia de Materiales de Sevilla, ICMS (CSIC-US), Spanien.
    Identification of Ternary Phases in TiBC/a-C Nanocomposite Thin Films: Influence on the Electrical and Optical Properties2011In: Plasma Processes and Polymers, ISSN 1612-8850, E-ISSN 1612-8869, Vol. 8, no 7, p. 579-588Article in journal (Refereed)
    Abstract [en]

    The local structure of TiBC and amorphous carbon (a-C) nanocomposite films (TiBC/a-C) was correlated with their optical and electrical properties. TiBC/a-C films with increasing C content were deposited by magnetron co-sputtering from TiC:TiB(2) (60: 40) and graphite targets. Chemical composition is determined by electron energy-loss spectroscopy. Grazing incidence X-ray diffraction reveals that the microstructure of the films is amorphous with small nanocrystallites emerging by increasing the C content that could be attributed to the formation of ternary (TiB(x)C(y)) or mixed binary (TiB(2) and TiC) phases. Further information was then obtained by studying the chemical bonding by measuring the near-edge fine structure (NES) by electron energy-loss (B K-, C K-, and Ti L-edges) and X-ray absorption (B K-and Ti L-edges) spectroscopies. The NES analysis indicates the formation of a nanocrystalline ternary TiB(x)C(y) compound concomitant with the segregation of an a-C phase as the carbon content is increased. The optical properties were studied by spectroscopic ellipsometry and the electrical resistivity was measured by the Van der Pauw method between 20 and 300 K. The films continuously lose their metallic character in terms of optical constants and resistivity with increasing carbon content. Theoretical fitting of the electrical properties using the grain-boundary scattering model supported the formation of a nanocomposite structure based on a ternary TiB(x)C(y) phase embedded in a matrix of a-C. The electron transport properties are mainly limited by the high density of point defects, grain size, and transmission probability.

  • 4.
    Abdallah, Ali
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Det smarta hemmet – Energianvändarens framtid: En studie om smarta hem och vilka möjligheter Jämtkraft har att satsa på dessa2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Energy consumption in Sweden is relatively large in terms of population. That depends a lot on the need for heating during most of the year because of the cold climate but also on the continuous need for energy in the everyday life. The large energy consumption entails, however, large loads on both climate and environment. Thus energy efficiency is an important measure to reduce the climate and environmental impact. Smart homes are complex systems that cover various aspects of the home but are considered to be an effective resource for improving energy efficiency.

    The purpose of this master’s thesis is to investigate how to develop or combine energy-efficient products in the best way possible. Energy consumers needs and behaviors have been analyzed and a market analysis of the products available on the market today has been performed based on a survey directed to energy users and interviews with energy users and stakeholders on the smart home market.

    Energy users show a lack of knowledge about smart homes and energy-smart products, probably because the smart homes market is still new in Sweden and most stakeholders have not managed to advertise themselves and their products yet. It may also depend on other factors such as energy users’ lack of interest in energy efficiency, which may be due to the low price of electricity in Sweden.

  • 5.
    Abdallah, Ali
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    The perception of Nuclear powerin Sweden: How engineering students view it2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nuclear power has been an important part of the electricity generatingin Sweden in almost half a century. However, the use of nuclear powerraises many complex issues such as economy, accident risks, andradioactive waste management and storage. Nuclear power has thereforebeen debated intensively in Sweden as in many other countries since the1970s. Several countries have changed their nuclear policy and starteddecommissioning programs following the nuclear accident in Fukushimaback in 2011. Citizens' support for nuclear power has declined worldwidein last few years, including in Sweden. This study aims to investigatethe perception of nuclear power among engineering students and showsthat the majority of engineering students, who generally are positivetowards technology, have been affected by their surrounding and areagainst nuclear power. Engineering students in general, both supportersand opponents of nuclear power, agree that Sweden should gradually phaseout nuclear power and replace it by renewable energy sources.

  • 6.
    Abdu, Yassir
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Physics, Department of Physics and Materials Science, Physics III. Technology, Department of Engineering Sciences, Solid State Physics.
    Ericsson, Tore
    Department of Physics. Physics, Department of Physics and Materials Science, Physics III. Technology, Department of Engineering Sciences, Solid State Physics.
    Nordblad, Per
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Physics, Department of Physics and Materials Science, Physics III. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Field-induced local magnetic moments in γ (FCC) Fe-Ni anti –Invar alloys2004In: J. Mag. Mag. Mater, Vol. 280, p. 243-250Article in journal (Refereed)
  • 7.
    Abdulahi Mohamed, Abdirahman
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Aksel, Wännström
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Quality Control of Light Emitting Diodes: Using power factor, harmonic distortion and light to power ratios2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study addresses quality control for Light Emitting Diodes (LED) according to fouraspects, the power factor of LED lamps, their harmonics and total harmonic distortion (THD), the luminosity for total power to radiated power ratio. It focuses on four brands and six different LED lamps, and concludes that IKEA's LED lamps pertain as the quality lamp, with a power factor over 0.9, THD less than 4% and a power to radiated light of over 4%. 

  • 8.
    Abele, P
    et al.
    tyskland.
    Öjefors, E
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Signals and systems.
    Schad, K B
    tyskland.
    and Schumacher H, Sonmez, E, Trasser A, Konle J
    tyskland.
    Wafer level integration of a 24 GHz differential SiGe-MMIC oscillator with a patch antenna using BCB as a dielectric layer2003Conference paper (Refereed)
  • 9.
    Abermann, S.
    et al.
    Institute of Solid State Electronics, Vienna University of Technology.
    Efavi, J. K.
    Sjöblom, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lemme, M. C.
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bertagnolli, E.
    Institute of Solid State Electronics, Vienna University of Technology.
    Impact of Al-, Ni-, TiN-, and Mo-metal gates on MOCVD-grown HfO2 and ZrO2 high-k dielectrics2007In: Microelectronics and reliability, ISSN 0026-2714, E-ISSN 1872-941X, Vol. 47, no 4-5, p. 536-539Article in journal (Refereed)
    Abstract [en]

    In this work we compare the impacts of nickel (Ni), titanium-nitride (TiN), molybdenum (Mo), and aluminium (Al), gates on MOS capacitors incorporating HfO2- or ZrO2-dielectrics. The primary focus lies on interface trapping, oxide charging, and thermodynamical stability during different annealing steps of these gate stacks. Whereas Ni, Mo, and especially TiN are investigated as most promising candidates for future CMOS devices, Al acted as reference gate material to benchmark the parameters. Post-metallization annealing of both, TiN- and Mo-stacks, resulted in very promising electrical characteristics. However, gate stacks annealed at temperatures of 800 °C or 950 °C show thermodynamic instability and related undesirable high leakage currents.

  • 10.
    Abermann, S.
    et al.
    Institute for Solid State Electronics, Vienna University of Technology.
    Efavi, J. K.
    Advanced Microelectronic Center, Aachen.
    Sjöblom, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lemme, M. C.
    Advanced Microelectronic Center, Aachen.
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bertagnolli, E.
    Institute for Solid State Electronics, Vienna University of Technology.
    Processing and evaluation of metal gate/high-k/Si capacitors incorporating Al, Ni, TiN, and Mo as metal gate, and ZrO2 and HfO2 as high-k dielectric2007In: Microelectronic Engineering, ISSN 0167-9317, E-ISSN 1873-5568, Vol. 84, no 5-8, p. 1635-1638Article in journal (Refereed)
    Abstract [en]

    We evaluate various metal gate/high-k/Si capacitors by their resulting electrical characteristics. Therefore, we process MOS gate stacks incorporating aluminium (Al), nickel (Ni), titanium-nitride (TiN), and molybdenum (Mo) as the gate material, and metal organic chemical vapour deposited (MOCVD) ZrO2 and HfO2 as the gate dielectric, respectively. The influence of the processing sequence - especially of the thermal annealing treatment - on the electrical characteristics of the various gate stacks is being investigated. Whereas post metallization annealing in forming gas atmosphere improves capacitance-voltage behaviour (due to reduced interface-, and oxide charge density), current-voltage characteristics degrade due to a higher leakage current after thermal treatment at higher temperatures. The Flatband-voltage values for the TiN-, Mo-, and Ni-capacitors indicate mid-gap pinning of the metal gates, however, Ni seems to be thermally unstable on ZrO2, at least within the process scheme we applied.

  • 11. Abermann, S
    et al.
    Efavi, J
    Sjöblom, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lemm, M
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bertagnolli, E
    Impact of Al-, Ni-, TiN-, and Mo metal gates on MOCVD-grown HfO2 and ZrO2 high-K dielectrics2006Conference paper (Refereed)
  • 12. Abermann, S.
    et al.
    Efavi, J.
    Sjöblom, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lemme, Max
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bertagnolli, E.
    Processing and evaluation of metal gate/high-k/Si capacitors incorporating Al, Ni, TiN, and Mo as metal gate, and ZrO2 and HfO2 as high-k dielectric2006In: Presented at Int. Conf. on Micro- and Nano-Engineering, 2006Conference paper (Other academic)
  • 13. Abermann, Stephan
    et al.
    Sjöblom, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Efavi, Johnson
    Lemme, Max
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bertagnolli, Emmerich
    Comparative Study On The Impact Of TiN and Mo Metal Gates ON MOCVD-Grown HfO2 and ZrO2 High-k Dielectrics For CMOS Technology2006In: Proceedings of 28th International Conference on the Physics of Semiconductors (ICPS) / [ed] Wolfgang Jantsch, Friedrich Schäffler, 2006Conference paper (Refereed)
  • 14.
    Abou-Ras, Daniel
    et al.
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Hahn Meitner Pl 1, D-14109 Berlin, Germany..
    Wagner, Sigurd
    Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA..
    Stanbery, Bill J.
    Siva Power, 5102 Calle Sol, Santa Clara, CA 95054 USA..
    Schock, Hans-Werner
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Hahn Meitner Pl 1, D-14109 Berlin, Germany..
    Scheer, Roland
    Martin Luther Univ Halle Wittenberg, Inst Phys, Photovolta Grp, D-06120 Halle, Saale, Germany..
    Stolt, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. Solibro Res AB, Sweden.
    Siebentritt, Susanne
    Univ Luxembourg, Phys & Mat Sci Res Unit, Lab Photovolta, Belvaux, Luxembourg..
    Lincot, Daniel
    CNRS EDF Chim Paristech PSL, Inst Photovolta Ile France IPVF, IRDEP, 6 Quai Watier, F-78401 Chatou, France..
    Eberspacher, Chris
    Solopower Syst Inc, Corp & Mfg Headquarters, 6308 North Marine Dr, Portland, OR 97203 USA..
    Kushiya, Katsumi
    Solar Frontier KK, 123-1 Shimo Kawairi, Atsugi, Kanagawa, Japan..
    Tiwari, Ayodhya N.
    Empa Swiss Fed Labs Mat Sci & Technol, Lab Thin Films & Photovolta, Ueberlandstr 129, CH-8600 Dubendorf, Switzerland..
    Innovation highway: Breakthrough milestones and key developments in chalcopyrite photovoltaics from a retrospective viewpoint2017In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 633, p. 2-12Article in journal (Refereed)
    Abstract [en]

    The present contribution is a summary of an event that was organized as a special evening session in Symposium V "Chalcogenide Thin-Film Solar Cells" at the E-MRS 2016 Spring Meeting, Lille, France. The presentations in this session were given by the coauthors of this paper. These authors present retrospectives of key developments in the field of Cu(In,Ga)(S,Se)(2) solar cells as they themselves had witnessed in their laboratories or companies. Also, anecdotes are brought up, which captured interesting circumstances in that evolutionary phase of the field. Because the focus was on historical perspectives rather than a comprehensive review of the field, recent developments intentionally were not addressed.

  • 15.
    Abrahamsson, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Dubois, Philip
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Englund, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    En jämförande studie av säljklimatet inom företagshälsovårdsmarknaden i Sverige2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study was performed to examine how start-up companies can identify the best-suited sales strategy to succeed in the Swedish market regarding occupational healthcare. Similar concerns has been raised on a general level, where the aim is to identify sales strategies for start-up companies' in relation to various micro markets. The study was conducted by an empirical case study of a company, Onelab, which recently has entered the Swedish occupational health services market. Onelab offer a service that provides personalized health profiles as a complement of today’s occupational health services. The empirical findings are based on nine semi-structured interviews of strategically selected companies in the technology and consulting industries with high-performance and highly educated co-workers. Furthermore this is an attempt to study sales and customer satisfaction from a HR-representative perspective. This since the HR- representative mainly is responsible for the company's occupational healthcare and the purchase of occupational health services. This paper culminates in a dynamic model that supports both start-ups and mature companies in the strategic decision making process. The model will determine strategic decision- making by taking both customer’s complexity and organization size into account. The findings from this specific case provide direct advice to the reference company, Onelab, that support the fact that they should not abandon the B2C market as well as using an informal sales process where the sales person, with guidance from the bosses, is given space to pursue potential customers in the way he or she sees fit for the specific situation. This is a limited empirical study with nine participants. Therefore, further studies are required to develop a deeper knowledge about the relation between sales strategies and start-up performance. The model generated in this study should also be further investigated in different sectors if general conclusions are to be made. 

  • 16.
    Abrahamsson, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Waltersson, Johanna
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    FLEXIBLA BYGGNADER: Utformning av en förskola med en möjlig verksamhetsändring för framtida behov2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Society today has an increasing demand for environmentally and economically sustainable developments in order to create a sustainable society. Society’s growth in new construction is a big part of this, and by planning and building more sustainable buildings these requirements can be fulfilled. The development of flexible buildings, which can adapt to future needs of society, lead to a more efficient utilization and longevity of premises and generate more sustainable buildings.In Sweden, the municipalities are the country’s largest property developers and therefore have a significant responsibility to provide society with real estate and public buildings. In recent time we have seen a shift towards flexible public buildings and in particular preschools. With the current socio-economic climate and ageing population buildings like preschools need to be flexible to ensure they can cater for future demands of society.

    This degree project, within the Bachelor programme in Construction Engineering, has been carried out during 10 weeks on Tengbom Architects in Uppsala. The thesis deals with the subject of flexibility in buildings and includes a proposal for the design of a flexible building as a pre-school that in the future can be converted into a retirement home.

  • 17.
    Abrahamsson, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Kinetic Energy Storage and Magnetic Bearings: for Vehicular Applications2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    One of the main challenges in order to make electric cars competitive with gas-powered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficientlyhigh specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application.

    A composite shell, comprising an inner part made of glassfiber and an outer part made of carbonfiber, was analyzed analytically and numerically, designed, and constructed. The shell was fitted onto a metallic rotor using shrinkfitting. The cost of the shell, and the complexity of assembly, was reduced by winding the glass- and carbonfiber consecutively on a mandrel, and curing the complete assembly simultaneously. Thereby, the shell obtained an internal segmentation, without the need for fitting several concentric parts onto each other. The radial stress inside the composite shell was kept compressive thanks to a novel approach of using the permanent magnets of the integrated electric machine to provide radial mechanical load during rotation.

    Two thrust bearing units (one upper and one lower) comprising one segmented unit with the permanent magnets in a cylindrical Halbach configuration and one non-segmented unit in a up/down configuration were optimized, constructed and tested. Each thrust bearing unit generated 1040 N of repelling force, and a positive axial stiffness of 169 N/mm at the nominal airgap of 5 mm. 

    Two radial active magnetic bearings (one upper and one lower) were optimized, constructed and tested. By parameterizing the shape of the actuators, a numerical optimization of force over resistive loss from the bias currentcould be performed. The optimized shape of the electromagnets was produced by watercutting sheets of laminated steel. A maximum current stiffness of120 N/A at a bias current of 1.5 A was achieved.

    List of papers
    1. Prototype of electric driveline with magnetically levitated double wound motor
    Open this publication in new window or tab >>Prototype of electric driveline with magnetically levitated double wound motor
    Show others...
    2010 (English)In: Electrical Machines (ICEM), 2010 XIX International Conference on, 2010Conference paper, Published paper (Refereed)
    Abstract [en]

    This paper presents the ongoing work of constructing a complete driveline for an electric road vehicle, using a flywheel as auxiliary energy storage. The flywheel energy storage system (FESS) is connected in series between the main energy storage (batteries) and the wheel motor of the vehicle, allowing the batteries to deliver power to the system in an optimized way, while at the same time making efficient use of regenerative braking. A double wound permanent magnet electric machine is used to electrically separate the two sides. In order to minimize losses, the machine has a double rotor configuration and is suspended with magnetic bearings. A bench test set-up is being constructed to investigate the properties of this system in detail. This set-up will achieve a level of power and energy close to that of a full scale system. This will allow measurements of complete drive cycles to be performed, improving the understanding of the constituting components and optimization of the complete system.

    Keyword
    electric drives, flywheels, magnetic bearings, permanent magnet machines, regenerative braking, road vehicles, auxiliary energy storage, double rotor configuration, double wound permanent magnet electric machine, electric driveline, electric road vehicle, flywheel energy storage system, magnetically levitated double wound motor, wheel motor
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-140370 (URN)
    Conference
    International Conference on Electrical Machines, ICEM
    Available from: 2011-01-05 Created: 2011-01-05 Last updated: 2016-04-18Bibliographically approved
    2. Magnetic bearings in kinetic energy storage systems for vehicular applications
    Open this publication in new window or tab >>Magnetic bearings in kinetic energy storage systems for vehicular applications
    2011 (English)In: Journal of Electrical Systems, ISSN 1112-5209, Vol. 7, no 2, p. 225-236Article in journal (Refereed) Published
    Abstract [en]

    The rotating Kinetic Energy Storage System (KESS) is suitable as temporary energy storage in electric vehicles due to its insensitivity to the number of charge-discharge cycles and its relatively high specific energy. The size and weight of the KESS for a given amount of stored energy are minimized by decreasing the moment of inertia of the rotor and increasing its speed. A small and fast rotor has the additional benefit of reducing the induced gyroscopic moments as the vehicle turns. The very high resulting rotational speed makes the magnetic bearing an essential component of the system, with the Active Magnetic Bearing (AMB) being the most common implementation. The complexity and cost of an AMB can be reduced by integration with the electric machine, resulting in a bearingless and sensorless electric machine. This review article describes the usage of magnetic bearings for FESS in vehicular applications.

    Keyword
    Magnetic bearing, FESS, flywheel, energy storage, electric vehicle
    National Category
    Engineering and Technology
    Research subject
    Engineering Science with specialization in Science of Electricity
    Identifiers
    urn:nbn:se:uu:diva-165038 (URN)
    Available from: 2012-01-02 Created: 2012-01-02 Last updated: 2017-12-08Bibliographically approved
    3. Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic
    Open this publication in new window or tab >>Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic
    2012 (English)Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    Arlington, Virginia, USA: , 2012
    National Category
    Engineering and Technology
    Research subject
    Engineering Science with specialization in Science of Electricity
    Identifiers
    urn:nbn:se:uu:diva-190197 (URN)
    Conference
    13th International Symposium on Magnetic Bearings
    Available from: 2013-01-07 Created: 2013-01-07 Last updated: 2017-04-06
    4. On the Efficiency of a Two-Power-Level Flywheel-Based All-Electric Driveline
    Open this publication in new window or tab >>On the Efficiency of a Two-Power-Level Flywheel-Based All-Electric Driveline
    Show others...
    2012 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 5, no 8, p. 2794-2817Article in journal (Refereed) Published
    Abstract [en]

    This paper presents experimental results on an innovative electric driveline employing a kinetic energy storage device as energy buffer. A conceptual division of losses in the system was created, separating the complete system into three parts according to their function. This conceptualization of the system yielded a meaningful definition of the concept of efficiency. Additionally, a thorough theoretical framework for the prediction of losses associated with energy storage and transfer in the system was developed. A large number of spin-down tests at varying pressure levels were performed. A separation of the measured data into the different physical processes responsible for power loss was achieved from the corresponding dependence on rotational velocity. This comparison yielded an estimate of the perpendicular resistivity of the stranded copper conductor of 2.5 x 10(-8) +/- 3.5 x 10(-9). Further, power and energy were measured system-wide during operation, and an analysis of the losses was performed. The analytical solution was able to reproduce the measured distribution of losses in the system to an accuracy of 4.7% (95% CI). It was found that the losses attributed to the function of kinetic energy storage in the system amounted to between 45% and 65%, depending on usage.

    Keyword
    kinetic energy storage, flywheel, electric machine, driveline, electric vehicle, losses
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Research subject
    Engineering Science with specialization in Science of Electricity
    Identifiers
    urn:nbn:se:uu:diva-182543 (URN)10.3390/en5082794 (DOI)000308241500011 ()
    Available from: 2012-10-11 Created: 2012-10-11 Last updated: 2017-12-07Bibliographically approved
    5. A Fully Levitated Cone-Shaped Lorentz-Type Self-Bearing Machine With Skewed Windings
    Open this publication in new window or tab >>A Fully Levitated Cone-Shaped Lorentz-Type Self-Bearing Machine With Skewed Windings
    2014 (English)In: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 50, no 9, article id 8101809Article in journal (Refereed) Published
    Abstract [en]

    Brushless dc coreless electric machines with double-rotor and single-stator configuration have very low losses, since the return path of the magnetic flux rotates with the permanent magnets. The eddy-current loss in the stator is additionally very small due to the lack of iron, making it ideal for kinetic energy storage. This paper presents a design for self-bearing rotor suspension, achieved by placing the stator windings skewed on a conical surface. A mathematical analysis of the force from a skewed winding confined to the surface of a cone was found. The parametric analytical expressions of the magnitude and direction of force and torque were verified by finite-element method simulations for one specific geometry. A dynamic model using proportional-integral-differential control was implemented in MATLAB/Simulink, and the currents needed for the self-bearing effect were found by solving an underdetermined system of linear equations. External forces, calculated from acceleration measurements from a bus in urban traffic, were added to simulate the dynamic environment of an electrical vehicle.

    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:uu:diva-212105 (URN)10.1109/TMAG.2014.2321104 (DOI)000343036900019 ()
    Available from: 2013-12-05 Created: 2013-12-05 Last updated: 2017-12-06Bibliographically approved
    6. Passive Axial Thrust Bearing for a Flywheel Energy Storage System
    Open this publication in new window or tab >>Passive Axial Thrust Bearing for a Flywheel Energy Storage System
    Show others...
    2013 (English)Conference paper, Published paper (Refereed)
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Research subject
    Engineering Science with specialization in Science of Electricity
    Identifiers
    urn:nbn:se:uu:diva-212104 (URN)
    Conference
    The 1st Brazilian Workshop on Magnetic Bearings
    Available from: 2013-12-05 Created: 2013-12-05 Last updated: 2017-10-24
    7. High-Speed Kinetic Energy Buffer: Optimization of Composite Shell and Magnetic Bearings
    Open this publication in new window or tab >>High-Speed Kinetic Energy Buffer: Optimization of Composite Shell and Magnetic Bearings
    2014 (English)In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 61, no 6, p. 3012-3021Article in journal (Refereed) Published
    Abstract [en]

    This paper presents the design and optimization of a high-speed (30 000 r/min) kinetic energy storage system. The purpose of the device is to function as an energy buffer storing up to 867 Wh, primarily for utility vehicles in urban traffic. The rotor comprises a solid composite shell of carbon and glass fibers in an epoxy matrix, constructed in one curing. The shell is optimized using a combined analytical and numerical approach. The radial stress in the shell is kept compressive by integrating the electric machine, thereby avoiding delamination. Radial centering is achieved through eight active electromagnetic actuators. The actuator geometry is optimized using a direct coupling between SolidWorks, Comsol, and Matlab for maximum force over resistive loss for a given current density. The optimization results in a system with 300% higher current stiffness than the reference geometry with constant flux area, at the expense of 33% higher power loss. The actuators are driven by semipassive H bridges and controlled by an FPGA. Current control at 20 kHz with a noise of less than 5 mA (95% CI) is achieved, allowing position control at 4 kHz to be implemented.

    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Research subject
    Engineering Science with specialization in Science of Electricity
    Identifiers
    urn:nbn:se:uu:diva-212101 (URN)10.1109/TIE.2013.2259782 (DOI)000329055300039 ()
    Available from: 2013-12-05 Created: 2013-12-05 Last updated: 2017-12-06Bibliographically approved
  • 18.
    Abrahamsson, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Kinetic Energy Storage and Magnetic Bearings, for vehicular applications2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    One of the main challenges in order to make electric cars competitive with gaspowered cars is in the improvement of the electric power system. Although many of the energy sources currently used in electric vehicles have sufficiently high specific energy, their applicability is limited due to low specific power. It would therefore be advantageous to create a driveline with the main energy storage separated from a smaller energy buffer, designed to have high power capabilities and to withstand frequent and deep discharge cycles. It has been found that rotating kinetic energy storage in flywheels is very well suited for this type of application. The work presented in this thesis and the included papers span a number of topcis Introductory overview - This section explains the concept of the modern flywheel, and investigates some of its properties. It illustrates the concepts with a number of examples, relevant for the usage of flywheels in vehicular applications. Experimental set-up - The construction of a complete electric driveline is ongoing within the division for Electricity at Uppsala University. An optimized electric machine has been constructed and connected with a programmable load, as well as with a DC power source through power electronics controlled by PWM. As a part of this system, an experimental set-up of an active magnetic bearing for two degrees-of-freedom has been constructed. The work with this device is described in detail and some preliminary results are presented. Self-bearing machine - The electric machine developed for the existing driveline is coreless, double wound and with a double rotor. In order to achieve magnetic bearing functionality in this device for all DOF, a novel Lorentz force self-bearing machine is suggested. The design is analyzed analytically and numerically.

  • 19.
    Abrahamsson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Bernhoff, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Magnetic bearings in kinetic energy storage systems for vehicular applications2011In: Journal of Electrical Systems, ISSN 1112-5209, Vol. 7, no 2, p. 225-236Article in journal (Refereed)
    Abstract [en]

    The rotating Kinetic Energy Storage System (KESS) is suitable as temporary energy storage in electric vehicles due to its insensitivity to the number of charge-discharge cycles and its relatively high specific energy. The size and weight of the KESS for a given amount of stored energy are minimized by decreasing the moment of inertia of the rotor and increasing its speed. A small and fast rotor has the additional benefit of reducing the induced gyroscopic moments as the vehicle turns. The very high resulting rotational speed makes the magnetic bearing an essential component of the system, with the Active Magnetic Bearing (AMB) being the most common implementation. The complexity and cost of an AMB can be reduced by integration with the electric machine, resulting in a bearingless and sensorless electric machine. This review article describes the usage of magnetic bearings for FESS in vehicular applications.

  • 20.
    Abrahamsson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    de Santiago, Juan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Oliveira, Janaína Gonçalves de
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Lundin, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Bernhoff, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Prototype of electric driveline with magnetically levitated double wound motor2010In: Electrical Machines (ICEM), 2010 XIX International Conference on, 2010Conference paper (Refereed)
    Abstract [en]

    This paper presents the ongoing work of constructing a complete driveline for an electric road vehicle, using a flywheel as auxiliary energy storage. The flywheel energy storage system (FESS) is connected in series between the main energy storage (batteries) and the wheel motor of the vehicle, allowing the batteries to deliver power to the system in an optimized way, while at the same time making efficient use of regenerative braking. A double wound permanent magnet electric machine is used to electrically separate the two sides. In order to minimize losses, the machine has a double rotor configuration and is suspended with magnetic bearings. A bench test set-up is being constructed to investigate the properties of this system in detail. This set-up will achieve a level of power and energy close to that of a full scale system. This will allow measurements of complete drive cycles to be performed, improving the understanding of the constituting components and optimization of the complete system.

  • 21.
    Abrahamsson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Gonçalves de Oliveira, Janaína
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    de Santiago, Juan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Lundin, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Bernhoff, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    On the Efficiency of a Two-Power-Level Flywheel-Based All-Electric Driveline2012In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 5, no 8, p. 2794-2817Article in journal (Refereed)
    Abstract [en]

    This paper presents experimental results on an innovative electric driveline employing a kinetic energy storage device as energy buffer. A conceptual division of losses in the system was created, separating the complete system into three parts according to their function. This conceptualization of the system yielded a meaningful definition of the concept of efficiency. Additionally, a thorough theoretical framework for the prediction of losses associated with energy storage and transfer in the system was developed. A large number of spin-down tests at varying pressure levels were performed. A separation of the measured data into the different physical processes responsible for power loss was achieved from the corresponding dependence on rotational velocity. This comparison yielded an estimate of the perpendicular resistivity of the stranded copper conductor of 2.5 x 10(-8) +/- 3.5 x 10(-9). Further, power and energy were measured system-wide during operation, and an analysis of the losses was performed. The analytical solution was able to reproduce the measured distribution of losses in the system to an accuracy of 4.7% (95% CI). It was found that the losses attributed to the function of kinetic energy storage in the system amounted to between 45% and 65%, depending on usage.

  • 22.
    Abrahamsson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Hedlund, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Bernhoff, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic2012Conference paper (Refereed)
  • 23.
    Abrahamsson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Hedlund, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Kamf, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Bernhoff, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    High-Speed Kinetic Energy Buffer: Optimization of Composite Shell and Magnetic Bearings2014In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 61, no 6, p. 3012-3021Article in journal (Refereed)
    Abstract [en]

    This paper presents the design and optimization of a high-speed (30 000 r/min) kinetic energy storage system. The purpose of the device is to function as an energy buffer storing up to 867 Wh, primarily for utility vehicles in urban traffic. The rotor comprises a solid composite shell of carbon and glass fibers in an epoxy matrix, constructed in one curing. The shell is optimized using a combined analytical and numerical approach. The radial stress in the shell is kept compressive by integrating the electric machine, thereby avoiding delamination. Radial centering is achieved through eight active electromagnetic actuators. The actuator geometry is optimized using a direct coupling between SolidWorks, Comsol, and Matlab for maximum force over resistive loss for a given current density. The optimization results in a system with 300% higher current stiffness than the reference geometry with constant flux area, at the expense of 33% higher power loss. The actuators are driven by semipassive H bridges and controlled by an FPGA. Current control at 20 kHz with a noise of less than 5 mA (95% CI) is achieved, allowing position control at 4 kHz to be implemented.

  • 24.
    Abrahamsson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Ögren, Jim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Hedlund, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    A Fully Levitated Cone-Shaped Lorentz-Type Self-Bearing Machine With Skewed Windings2014In: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 50, no 9, article id 8101809Article in journal (Refereed)
    Abstract [en]

    Brushless dc coreless electric machines with double-rotor and single-stator configuration have very low losses, since the return path of the magnetic flux rotates with the permanent magnets. The eddy-current loss in the stator is additionally very small due to the lack of iron, making it ideal for kinetic energy storage. This paper presents a design for self-bearing rotor suspension, achieved by placing the stator windings skewed on a conical surface. A mathematical analysis of the force from a skewed winding confined to the surface of a cone was found. The parametric analytical expressions of the magnitude and direction of force and torque were verified by finite-element method simulations for one specific geometry. A dynamic model using proportional-integral-differential control was implemented in MATLAB/Simulink, and the currents needed for the self-bearing effect were found by solving an underdetermined system of linear equations. External forces, calculated from acceleration measurements from a bus in urban traffic, were added to simulate the dynamic environment of an electrical vehicle.

  • 25.
    Abrahamsson, Niklas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Individuell mätning och debitering av värme i flerbostadshus: Svenska förutsättningar i jämförelse med erfarenheter från Tyskland och Danmark2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today it is unusual to use consumption based billing of heat in Swedish apartment buildings. This is more common in the rest of Europe and this study aims to learn about experiences and possible problems from Germany and Denmark, which are countries who have this system implemented in their law. The current study is made on behalf of the Swedish Union of Tenants, the Swedish Association of Public Housing Companies (SABO) and the Swedish Property Federation as part of a project where these organizations want to establish a recommendation for their members if they would like to start using the method.

    Differences within countries that are examined include climate, the property´s energy performance, local habits, rent-setting system, business model for energy sales and the law. The techniques to measure consumption are also described. The main objective of this report is to increase understanding and knowledge in this subject. The report is meant to serve as a basis for a recommendation on introducing this system in Sweden.

    As can be seen from the comparison, Sweden in many cases has similar conditions as Germany and Denmark. There are also substantial differences. For example it may be difficult to transfer heating costs separately from the basic rent because of the Swedish rent-setting system. Due to the colder climate in Sweden, the energy savings would be greater in absolute terms. It can also be seen that German and Danish laws regulates the market in a similar way. If implemented in Sweden in its current form, the European Energy Directive could force legislation for the mandatory introduction of the system.

  • 26.
    Abro, Mehwish
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Modelling the exfoliation of graphite for production of graphene2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of my thesis is to make a theoretical model of data obtained from liquid-phase exfoliation of graphene. The production of graphene in the liquid phase exfoliation is a cost efficient method One part of this work is devotedto learn the method of production of graphene by the shear mixing technique from the graphite and to estimate some important parameters which are crucial for the process. Other part of my work is based on studying the liquid-phase exfoliation mechanism of graphene through ultrasonication technique. This method is time consuming as compared to shearmixing.

  • 27.
    Absil, Oliver
    et al.
    Université de Liège, Belgium.
    Mawet, Dimitri
    California Institute of Technology/Jet Propulsion Laboratory, USA.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Carlomagno, Brunella
    Université de Liège, Belgium.
    Christiaens, Valentin
    Universidad de Chile, Chile.
    Defrère, Denis
    Université de Liège, Belgium.
    Delacroix, Christian
    Cornell University, USA.
    Femenía Castellá, Bruno
    W. M. Keck Observatory, USA.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Girard, Julien
    European Southern Observatory, Chile.
    Gómez González, Carlos A.
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Hinz, Philip M.
    University of Arizona, USA.
    Huby, Elsa
    Université de Liège, Belgium.
    Jolivet, Aissa
    Université de Liège, Belgium.
    Matthews, Keith
    California Institute of Technology, USA.
    Milli, Julien
    European Southern Observatory, USA.
    Orban de Xivry, Gilles
    Université de Liège, Belgium.
    Pantin, Eric
    Université Paris Diderot, France.
    Piron, Pierre
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Reggiani, Maddalena
    Université de Liège, Belgium.
    Ruane, Garreth J.
    California Institute of Technology, USA.
    Serabyn, Eugene
    Jet Propulsion Laboratory, USA.
    Surdej, Jean
    Université de Liège, Belgium.
    Tristram, Konrad R. W.
    European Southern Observatory, Chile.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wertz, Olivier
    Université de Liège, Belgium.
    Wizinowich, Peter
    W. M. Keck Observatory, USA.
    Three years of harvest with the vector vortex coronagraph in the thermal infrared2016In: Ground-Based and Airborne Instrumentation for Astronomy VI: 26-30 June 2016, Edinburgh, United Kingdom / [ed] Christopher J Evans, SPIE - International Society for Optical Engineering, 2016, Vol. 9908, p. 1-14, article id 99080Q-1Conference paper (Refereed)
    Abstract [en]

    For several years, we have been developing vortex phase masks based on sub-wavelength gratings, known as Annular Groove Phase Masks. Etched onto diamond substrates, these AGPMs are currently designed to be used in the thermal infrared (ranging from 3 to 13 μm). Our AGPMs were first installed on VLT/NACO and VLT/VISIR in 2012, followed by LBT/LMIRCam in 2013 and Keck/NIRC2 in 2015. In this paper, we review the development, commissioning, on-sky performance, and early scientific results of these new coronagraphic modes and report on the lessons learned. We conclude with perspectives for future developments and applications.

  • 28. Absil, Olivier
    et al.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mawet, Dimitri
    Carlomagno, Brunella
    Christiaens, Valentin
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Gomez Gonzales, Carlos
    Habraken, Serge
    Jolivet, Aïssa
    Piron, Pierre
    Van Droogenbroeck, Marc
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Absil, Pierre-Antoine
    Boccaletti, Anthony
    Baudoz, Pierre
    Defrère, Dennis
    Milli, Julien
    Surdej, Sean
    Optimized, high performance vortex coronagraphs for E-ELT instruments2014Conference paper (Refereed)
  • 29. Absil, Olivier
    et al.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mawet, Dimitri
    Carlomagno, Brunella
    Christiaens, Valentin
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Gomez Gonzales, Carlos
    Habraken, Serge
    Jolivet, Aïssa
    Piron, Pierre
    Van Droogenbroeck, Marc
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Absil, Pierre-Antoine
    Boccaletti, Anthony
    Baudoz, Pierre
    Defrère, Dennis
    Milli, Julien
    Surdej, Sean
    Reaching the diffraction limit with the vortex coronagraph2014Conference paper (Refereed)
  • 30. Absil, Olivier
    et al.
    Mawet, Dimitri
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Surdej, Jean
    Absil, Pierre-Antoine
    Carlomagno, Brunella
    Christiaens, Valentin
    Defrere, Denis
    Gonzalez, Carlos Gomez
    Huby, Elsa
    Jolivet, Aissa
    Milli, Julien
    Piron, Pierre
    Catalan, Ernesto Vargas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Van Droogenbroeck, Marc
    The VORTEX project: first results and perspectives2014In: Adaptive Optics Systems IV, 2014, article id 91480MConference paper (Refereed)
    Abstract [en]

    Vortex coronagraphs are among the most promising solutions to perform high contrast imaging at small angular separations from bright stars. They feature a very small inner working angle (down to the diffraction limit of the telescope), a clear 360 degree discovery space, have demonstrated very high contrast capabilities, are easy to implement on high-contrast imaging instruments, and have already been extensively tested on the sky. Since 2005, we have been designing, developing and testing an implementation of the charge-2 vector vortex phase mask based on concentric sub-wavelength gratings, referred to as the Annular Groove Phase Mask (AGPM). Science-grade mid-infrared AGPMs were produced in 2012 for the first time, using plasma etching on synthetic diamond substrates. They have been validated on a coronagraphic test bench, showing broadband peak rejection up to 500: 1 in the L band, which translates into a raw contrast of about 6 x 10(-5) at 2 lambda/D. Three of them have now been installed on world-leading diffraction-limited infrared cameras, namely VLT/NACO, VLT/VISIR and LBT/LMIRCam. During the science verification observations with our L-band AGPM on NACO, we observed the beta Pictoris system and obtained unprecedented sensitivity limits to planetary companions down to the diffraction limit (0 : 1 0 0). More recently, we obtained new images of the HR 8799 system at L band during the AGPM first light on LMIRCam. After reviewing these first results obtained with mid-infrared AGPMs, we will discuss the short-and mid-term goals of the on-going VORTEX project, which aims to improve the performance of our vortex phase masks for future applications on second-generation high-contrast imager and on future extremely large telescopes (ELTs). In particular, we will briefly describe our current efforts to improve the manufacturing of mid-infrared AGPMs, to push their operation to shorter wavelengths, and to provide deeper starlight extinction by creating new designs for higher topological charge vortices. Within the VORTEX project, we also plan to develop new image processing techniques tailored to coronagraphic images, and to study some pre- and post-coronagraphic concepts adapted to the vortex coronagraph in order to reduce scattered starlight in the final images.

  • 31. Absil, Olivier
    et al.
    Mawet, Dimitri
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Surdej, Jean
    Absil, Pierre-Antoine
    Carlomagno, Brunella
    Christiaens, Valentin
    Defrère, Denis
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Girard, Julien
    Gomez Gonzalez, Carlos
    Hinz, Philip
    Huby, Elsa
    Jolivet, Aïssa
    Milli, Julien
    Pantin, Eric
    Ruane, Garreth
    Serabyn, Eugene
    Van Droogenbroeck, Marc
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wertz, Olivier
    An update on the VORTEX project2015In: Techniques and Instrumentation for Detection of Exoplanets VII, 2015, Vol. 9605Conference paper (Refereed)
    Abstract [en]

    In this talk, we will review the on-going activities within the VORTEX teamat the University of Liège and Uppsala University. The VORTEX project aimsto design, manufacture, test, and exploit vector vortex phase masks madeof sub-wavelength gratings (aka the Annular Groove Phase Mask, AGPM)for the direct detection and characterization of extrasolar planets. This talkwill specifically report on the commissioning of several AGPMs on infraredcameras equipping 10-m class telescopes, including the VLT, the LBT andthe Keck. We will describe the in-lab and on-sky performance of the AGPMs,and discuss first scientific observations. We will also report on the lessonslearned from the on-sky operation of our vortices, and discuss ways toimprove their performance. The potential of our coronagraphic devices inthe context of future extremely large telescopes and space missions will alsobe addressed.

  • 32.
    Abujheisha, Belal
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Laserinkopplingselement För XFEL Laser Heater: Från Idé Till Färdig Produkt I Designstadie2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Uppsala University is involved in a large international collaborationto build the Laser heater system for the European Xray Free-electronlaser in Hamburg, Germany. In this thesis I describe a laser incouplingdevice into the vacuum chamber of this laser heater all the way fromthe specifications to a completed design.

    The laser heater is a very important part of the XFEL and thepart described here is a part of the vacuum system needed to couplean external laser into the electron vacuum system and align it withthe electron bunches in order to heat them. The task was started by studying the literature about the basic theory andthe design of vacuum systems. After this study and collection of ideaswith colleagues I started to prepare different concepts to solve thetask. The ideas can be put into two categories, in one case the couplingmirror is located inside the vacuum chamber and in the second caseoutside. The concepts were evaluated with colleagues from the physicsdepartment and one solution from each category was evaluated further. The work continued to develop and refine these concpets. During the workseveral obstacles appeared, the biggest one was that with the 'inside'concept some of the design constraints had to be disregarded, butduring further work the design was adapted and the problems weremostly solved.

    The concept with the mirror outside the vacuumchamber was succesfuland the design was completed. In this thesis SolidWorks was used for the design work of thedifferent concepts and all parts that are part of the icouplingelement for the XFEL laser heater. All drawings are generated inSolidWorks as well and are attached to this report.

  • 33.
    Abuzohri, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    Business Development: Market research & feasibility study of a PV-wind hybrid system for commercial use2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The definition of environmental sustainability has emerged strongly in the past decades. Industrial organizations worldwide have gone through a number of changes to take their social responsibilities and maintain sustainability by, among other things, replacing the conventional energy-based applications by renewable energy-based solutions. A so-called hybrid power system for electrification, consisting of wind turbines and solar panels, was developed by Vertical Wind AB to be installed on rooftops of residential buildings. The present thesis project analyzed the willingness of the large real estate companies in Uppsala region to adopt the new concept for electrification and conducted a market research on the new developed wind turbines, by Vertical Wind AB, in addition to solar- and wind resources in the target locations. It turned out that the willingness of having such a power system for electrification was high but not extremely high as expected and the hybrid power system was perceived as any other product or investment on the market where profitability is the vital decision parameter while the environmental aspect was slightly considered.

  • 34.
    Abuzohri, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Effektförstärkare med strömkontroll2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Energin är ett begrepp som används dagligen i vårt samhälle. Energin kan inte skapas men däremot kan den omvandlas till olika former, förbrukas och lagras i vissa fall. Men att omvandla energi från en form till en annan form för att sedan lagra den är en av dagens stora utmaningar inom tekniken då vi måste följa de regler som naturen dikterar. Forskning på detta område har pågått i flera decennier för att kunna ta fram lämpliga och effektiva sätt att lagra energi på. Svänghjul-system är ett sådant sätt där man kan lagra energi under begränsad tid.

    I mitt examensarbete har jag utnyttjat kunskapen som jag har lärt mig från elektronik kurserna för att konstruera en effektförstärkare med strömkontroll som användes för att driva ett svänghjul-system. Förstärkaren har byggts med elektronikkomponenter och styrs från datorn med m.h.a. styrprogrammet LabVIEW som kommunicerar med hårdvaran och kontrollerar svänghjulets rörelse.

  • 35.
    Abuzohri, Ahmed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Dizdarevic, Zlatko
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Skapa öppenhet i erfarenhetsregistrering vid Forsmarks Kraftgrupp AB2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project is a thesis work conducted at the Forsmark nuclear power plant at the FTQ department. The FTQ department at Forsmark is responsible for the experience feedback cases in the facility and supplying the organization with new insights regarding experience feedback techniques. About 10 years ago Forsmark Power Group Ltd realized the need to introduce an active experience feedback process to avoid repeating mistakes. This resulted in a creation of a new department in 2008 with the name of FTQ. Later, the FTQ department created a system with a database named ERFKA where all experience feedback cases have been collected and stored. In addition to the ERFKA database, the system contains a presentation tool that enables data in the database to be presented graphically at the FTQ department, such as statistics on incidents, accidents, monthly reports, reports and more.

    The ERFKA-system fulfills its purpose in this context but for safety reasons it is only available for approximately 15 people. It results in that FTQ department always needs to be contacted to develop information to others in the facility which is time-consuming and complicated in a big organization like Forsmark.

    The thesis project was focused in creating openness in the ERFKA-system with regard to safety aspects in the facility. By simply making the information in ERFKA available for everyone at Forsmark, without having to contact the FTQ department, and simultaneously use the tools that already are available on the power plant was this project carried out.

    The first part was accomplished by interviews in an attempt to specify the information types that were desired to be available. In pursuit of this information, we interviewed those people who were most familiar with the experience feedback improvement and could have most influence on the results.

    The second part was carried out through developing an acceptable proposed solution for a connection model to present information on the Forsmark intranet “Canalen” using those available tools. Due to the security limits in the facility, just few administrators can access the ERFKA. Therefore, the solution has been formed to transfer information from ERFKA to an already proven statistics and graph generating program called Bi-Cycle, which is available for all employees in the organization.

    During the project, a diagram of a possible link model has been created where all parts of the communication are clearly displayed. The model includes every detailed section beginning with Canalen, graphs in Bi-Cycle and ending with the final report.

  • 36. Ackeby, Susanne
    et al.
    Bollen, Math
    Munkhammar, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Prosumer with demand-response: Distribution network impact and mitigation2013Report (Refereed)
  • 37.
    Ackeby, Susanne
    et al.
    STRI.
    Bollen, Math
    Luleå tekniska universitet.
    Munkhammar, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Prosumer with demand-response:Distribution network impact and mitigation2013Report (Other academic)
    Abstract [en]

    This report is the result from a project funded by ELFORSK done by STRI. Theproject is studying the effects the introduction of so called “prosumers”(customers with own production) and electrical vehicles will have on differenttypes of networks. Four different cases are studied: covering urban and ruralareas with different types of customers.In the urban areas the power through the transformer will be the limitingfactor. The major impact in the cases studied is from the introduction ofproduction from photovoltaics at the customer-side of the meter. This willresult in an introduction of surplus due to production which in one case led toan increase of the absolute power through the transformer with more than30%, which resulted in transformer overloading.In the rural areas the voltage drop or rise will be the limiting factor. The casesstudied had already high voltage drops even in the base cases. In the casestudies it was seen that the voltage drop could be slightly reduced whenintroducing more local production, but the production also led to that voltagerise could appear. As a result the interval of the voltage variations wasincreased, which in turn leads to difficulties with designing the network suchthat neither overvoltage nor undervoltage occurs.Introducing control algorithms had a very positive effect on reducing the netproduction from the photovoltaics. Using both hard and soft curtailment madeit possible to remove all overcurrents or overvoltages. Using hard curtailment,where all production is turned off during overcurrent or overvoltage, leadshowever to a large reduction in energy from renewable energy sources.Therefore soft curtailment should as much as possible be used.The control algorithms studied for reducing the net consumption had a morelimited effect and even resulted in an increase of the maximum netconsumption. When trying to reduce the net consumption during an overload,the reason of the overload could only be moved in time and not removed as inthe case of reducing the net production. And since often the period duringwhich the power exceeds the limit is longer than the number of hours possibleto move the energy, sometimes moving the energy had an adverse effect.The model used for controlling the net consumption needs furtherdevelopment, but it is still possible to draw the conclusion that this type ofcontrol offers only limited possibilities for mitigating overload or undervoltage.The effects of introducing prosumers and more electrical vehicles as defined inthe selected cases did not show any alarming results in this study. However,studies to learn more about the possible consequences of changes atcustomer-side are important to be able to handle the impact of such changeson the network.Further future studies needed: database with load and production data;improved control algorithms; demonstration project; experience from othercountries and studies on reactive power compensation.

  • 38.
    Adams, Christopher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences.
    Secondary and Higher Order Structural Characterization of Peptides and Proteins by Mass Spectrometry2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The work in this thesis has demonstrated the advantages and limitations of using MS based technologies in protein and peptide structural studies.

    Tandem MS, specifically electron capture dissociation (ECD) have shown the ability to provide structural insights in molecules containing the slightest of all modifications (D-AA substitution). Additionally, it can be concluded that charge localization in molecular ions is best identified with ECD and to a lesser degree using CAD.

    Fragment ion abundances are a quantifiable tool providing chiral recognition (RChiral). An analytical model demonstrating the detection and quantification of D-AAs within proteins and peptides has been achieved. ECD has demonstrated the ability to quantify stereoisomeric mixtures to as little as 1%. Chirality elucidation on a nano LC-MS/MS time scale has been shown.

    The structures of various stereoisomers of the mini protein Trp Cage were explored, each providing unique ECD fragment ion abundances suggestive of gas phase structural differences. The uniqueness of these abundances combined with MDS data have been used in proposing a new mechanism in c and z fragment ion formation in ECD. This mechanism suggests initial electron capture on a backbone amide involved in (neutral) hydrogen bonding.

    The wealth of solution phase (circular dichroism), transitition phase (charge state distribution, CSD) and gas phase (ECD) data for Trp Cage suggest that at low charge states (2+) the molecule has a high degree of structural similarity in solution- and gas- phases. Furthermore, quantitative information from CSD studies is garnered when using a “native” deuteriated form as part of the stereoisomeric mixture. It has also been shown that the stability of the reduced species after electron capture is indicative of the recombination energy release, which in turn is linked to the coulombic repulsion- a structural constraint that can be used for approximation of the inter-charge distance for various stereoisomers.

    List of papers
    1. Electron capture dissociation distinguishes a single D-amino acid in a protein and probes the tertiary structure
    Open this publication in new window or tab >>Electron capture dissociation distinguishes a single D-amino acid in a protein and probes the tertiary structure
    In: Journal of The American Society for Mass Spectrometry, ISSN 1044-0305, Vol. 15, no 7, p. 1087-1098Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95861 (URN)
    Available from: 2007-05-07 Created: 2007-05-07Bibliographically approved
    2. Determination of the location of positive charges in gas-phase polypeptide polycations by tandem mass spectrometry
    Open this publication in new window or tab >>Determination of the location of positive charges in gas-phase polypeptide polycations by tandem mass spectrometry
    2006 (English)In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 252, no 3, p. 204-212Article in journal (Refereed) Published
    Abstract [en]

    Location of protonated sites in electrospray-ionized gas-phase peptides and proteins was performed with tandem mass spectrometry using ion activation by both electron capture dissociation (ECD) and collisional activation dissociation (CAD). Charge-carrying sites were assigned based on the increment in the charge state of fragment ions compared to that of the previous fragment in the same series. The property of ECD to neutralize preferentially the least basic site was confirmed by the analysis of three thousand ECD mass spectra of doubly charged tryptic peptides. Multiply charged cations of bradykinin, neurotensin and melittin were studied in detail. For n+ precursors, ECD revealed the positions of (n − 1) most basic sites, while CAD could in principle locate all n charges. However, ECD introduced minimal proton mobilization and produced more conclusive data than CAD, for which N- and C-terminal data often disagreed. Consistent with the dominance of one charge conformer and its preservation in ECD, the average charge states of complementary fragments of n+ ions almost always added up to (n − 1)+, while the similar figure in CAD often deviated from n+, indicating extensive charge isomerization under collisional excitation. For bradykinin and neurotensin, the charge assignments were largely in agreement with the intrinsic gas-phase basicity of the respective amino acid residues. For melittin ions in higher charge states, ECD revealed the charging at both intrinsically basic as well as at less basic residues, which was attributed to charge sharing with other groups due to the presence of secondary and higher order structures in this larger polypeptide.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-95862 (URN)10.1016/j.ijms.2005.10.009 (DOI)
    Available from: 2007-05-07 Created: 2007-05-07 Last updated: 2017-12-14Bibliographically approved
    3. Distinguishing and quantifying peptides and proteins containing D-amino acids by tandem mass spectrometry
    Open this publication in new window or tab >>Distinguishing and quantifying peptides and proteins containing D-amino acids by tandem mass spectrometry
    In: Analytical Chemistry, ISSN 0003-2700, Vol. 77, no 14, p. 4571-4580Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95863 (URN)
    Available from: 2007-05-07 Created: 2007-05-07Bibliographically approved
    4. Prediction of N-C-alpha bond cleavage frequencies in electron capture dissociation of Trp-cage dications by force-field molecular dynamics simulations
    Open this publication in new window or tab >>Prediction of N-C-alpha bond cleavage frequencies in electron capture dissociation of Trp-cage dications by force-field molecular dynamics simulations
    Show others...
    In: International Journal of Mass Spectrometry, ISSN 1387-3806, Vol. 248, no 3, p. 124-135Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95864 (URN)
    Available from: 2007-05-07 Created: 2007-05-07Bibliographically approved
    5. Probing Solution-Phase and Gas-Phase Structures of Trp-cage Cations by Chiral Substitution and Spectroscopic Techniques
    Open this publication in new window or tab >>Probing Solution-Phase and Gas-Phase Structures of Trp-cage Cations by Chiral Substitution and Spectroscopic Techniques
    Show others...
    2006 (English)In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 253, no 3, p. 263-273Article in journal (Refereed) Published
    Abstract [en]

    The relevance of gas-phase protein structure to its solution structure is of the utmost importance in studying biomolecules by mass spectrometry. D-Amino acid substitutions within a minimal protein. Trp-cage. were used to correlate solution-phase properties as measured by circular dichroism with solution/gas-phase conformational features of protein cations probed via charge state distribution (CSD) in electrospray ionization. and gas-phase features revealed by tandem mass spectrometry (MS/MS). The gas-phase features were additionally supported by force-field molecular dynamics simulations. CD data showed that almost any single-residue D-substitution destroys the most prominent CD feature of the "native" all-L isomer, alpha-helicity. CSD was able to qualitatively assess the degree of compactness of solution-phase molecular structures. CSD results were consistent with the all-L form being the most compact in solution among all studied stereoisomers except for the D-Asn(1) isomer. D-substitutions of the aromatic Y(3), W(6) and Q(5) residues generated the largest deviations in CSD data among single amino acid substitutions. consistent with the critical role of these residues in Trp-cage stability. Electron capture dissociation of the stereoisomer dications gave an indication that some gas-phase structural features of Trp-cage are similar to those in solution. This result is supported by MDS data oil five of the studied stereoisomer dications in the gas-phase. The MDS-derived minimum-energy structures possessed more extensive hydrogen bonding than the solution-phase structure of the native form, deviating from the latter by 3-4 angstrom and were not 'inside-out' compared to native structures. MDS data could be correlated with CD data and even with ECD results. which aided in providing a long-range structural constraint for MDS. The overall conclusion is the general resemblance, despite the difference on the detailed level, of the preferred structures in both phases for the mini protein Trp-cage.

    Keyword
    solution structure; gas-phase structure; chirality; electron capture dissociation; charge state distribution
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-95865 (URN)10.1016/j.ijms.2006.04.012 (DOI)000238967500014 ()
    Available from: 2007-05-07 Created: 2007-05-07 Last updated: 2017-12-14Bibliographically approved
  • 39.
    Adams, Christopher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences.
    Kjeldsen, Frank
    Haselmann, Kim
    Zubarev, Roman
    Electron capture dissociation distinguishes a single D-amino acid in a protein and probes the tertiary structureIn: Journal of The American Society for Mass Spectrometry, ISSN 1044-0305, Vol. 15, no 7, p. 1087-1098Article in journal (Refereed)
  • 40.
    Adams, Christopher
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Kjeldsen, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Patriksson, Alexandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    van Der Spoel, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Gräslund, Astrid
    Papadopolous, Evangelos
    Zubarev, Roman
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Probing Solution-Phase and Gas-Phase Structures of Trp-cage Cations by Chiral Substitution and Spectroscopic Techniques2006In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 253, no 3, p. 263-273Article in journal (Refereed)
    Abstract [en]

    The relevance of gas-phase protein structure to its solution structure is of the utmost importance in studying biomolecules by mass spectrometry. D-Amino acid substitutions within a minimal protein. Trp-cage. were used to correlate solution-phase properties as measured by circular dichroism with solution/gas-phase conformational features of protein cations probed via charge state distribution (CSD) in electrospray ionization. and gas-phase features revealed by tandem mass spectrometry (MS/MS). The gas-phase features were additionally supported by force-field molecular dynamics simulations. CD data showed that almost any single-residue D-substitution destroys the most prominent CD feature of the "native" all-L isomer, alpha-helicity. CSD was able to qualitatively assess the degree of compactness of solution-phase molecular structures. CSD results were consistent with the all-L form being the most compact in solution among all studied stereoisomers except for the D-Asn(1) isomer. D-substitutions of the aromatic Y(3), W(6) and Q(5) residues generated the largest deviations in CSD data among single amino acid substitutions. consistent with the critical role of these residues in Trp-cage stability. Electron capture dissociation of the stereoisomer dications gave an indication that some gas-phase structural features of Trp-cage are similar to those in solution. This result is supported by MDS data oil five of the studied stereoisomer dications in the gas-phase. The MDS-derived minimum-energy structures possessed more extensive hydrogen bonding than the solution-phase structure of the native form, deviating from the latter by 3-4 angstrom and were not 'inside-out' compared to native structures. MDS data could be correlated with CD data and even with ECD results. which aided in providing a long-range structural constraint for MDS. The overall conclusion is the general resemblance, despite the difference on the detailed level, of the preferred structures in both phases for the mini protein Trp-cage.

  • 41.
    Adams, Christopher M
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. jonfysik.
    Kjeldsen, Frank
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. jonfysik.
    Zubarev, Roman A
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. jonfysik.
    Budnik, Bogdan A
    jonfysik.
    Haselmann, Kim F
    Electron capture dissociation distinguishes a single D-amino acid in a protein and probes the tertiary structure.2004In: J Am Soc Mass Spectrom, ISSN 1044-0305, Vol. 15, no 7, p. 1087-98Article in journal (Refereed)
  • 42.
    Adams, Christopher M
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Materials Science. Department of Engineering Sciences, Ion Physics. Ion physics.
    Zubarev, Roman A
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Materials Science. Department of Engineering Sciences, Ion Physics. Ion physics.
    Distinguishing and quantifying peptides and proteins containing D-amino acids by tandem mass spectrometry.2005In: Anal Chem, ISSN 0003-2700, Vol. 77, no 14, p. 4571-80Article in journal (Refereed)
  • 43.
    Adams, Christopher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences.
    Zubarev, Roman
    Distinguishing and quantifying peptides and proteins containing D-amino acids by tandem mass spectrometryIn: Analytical Chemistry, ISSN 0003-2700, Vol. 77, no 14, p. 4571-4580Article in journal (Refereed)
  • 44. Adell, M
    et al.
    Kanski, J
    Stanciu, V
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Ilver, L
    Sadowski, J
    Svedlindh, P
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Comment on “Mn interstitial diffusion in (Ga,Mn)As”2005In: Phys. Rev. Lett., Vol. 94, p. 139701-Article in journal (Refereed)
  • 45. Adell, M
    et al.
    Staniciu, V
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Kanski, J
    Ilver, L
    Sadowski, J
    Domagala, J Z
    Svedlindh, P
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Terki, F
    Hernandez, C
    Charar, S
    Post-growth annealing of (Ga,Mn)As under As capping – an alternative way to increase Tc2005In: Apåpl. Phys. Lett., Vol. 86, p. 112501-Article in journal (Refereed)
  • 46. Adell, Martin
    et al.
    Ilver, Lars
    Kanski, Janusz
    Stanciu, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Svedlindh, Peter
    Sadowski, Janusz
    Domagala, J.Z.
    Terki, F.
    Hernandez, C.
    Charar, S.
    Postgrowth annealing of (Ga,Mn)As under As capping: An alternative way to increase Tc2005In: Applied Physics Letters, Vol. 86, p. 112501-Article in journal (Refereed)
  • 47.
    Adolfsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Simplified finite element bearing modeling: with NX Nastran2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report was produced at the request of ABB Robotics and the work was conducted at their facilities in Västerås, Sweden.

    In the development of industrial robots the structures are slimmed to increase the accuracy and speed. When conducting finite element analysis on the robots the accuracy of the component modelling and definitions of the boundary conditions becomes more important. One such component is the ball bearing which consist of several parts and has a nonlinear behavior where the balls are in contact with the rings.

    The task given was to develop new methods to model roller bearings in Siemens finite element modelling software NX Nastran. Then conduct a strain measurement, to compare the methods to real experimental values. The goal with the report is to find one or more methods to model roller bearings, with accurate results, that can beused in their development work.

    The report was conducted by first doing a study on bearings and finite element modeling, and learning to use the software NX Nastran. Then the development of the methods were done by generating ideas for bearing models and testing them on simple structures. Nine methods was produced and a tenth, the method used to model bearings today, was used as a reference. The methods was used to build bearing models in a finite element model of a six axis robot wrist.

    Simulations were done on the models with different load cases and the results were compared to a strain measurement of the wrists real counterpart. Only six of the models were analyzed in the result, since four of the models returned results that were deemed unusable.

    When compiling the result data no model was found to accurately recreate the stresses in every load case. Three methods, that allow deformation, performed similarly. One of them is suggested to be used as modelling method in the future. Worst of the methods, according to the results compiled, was found to be the method used today. It fails to describe local stresses around the bearing. For continued work it is suggested that linear contact elements is studied further. Four out of five models constructed with linear contact elements failed to return satisfactory results.

  • 48.
    Adrian, Ehrnebo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Single Crystalline CVD Diamond Based Devices for Power Electronics Applications2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Chemical vapor deposited single-crystalline diamond has rare material properties such as thermal conductivity five times as high as copper, a wide band gap, a high breakdown field and high carrier mobilities. This makes it a very interesting material for high power, high frequency and high temperature applications.

    In this thesis work, metal oxide semiconductor (MOS) capacitors of diamond substrate were fabricated and analyzed. The MOS capacitor is a building block of the metal oxide semiconductor field effect transistor (MOSFET). Capacitance-voltage (C-V) measurements can provide useful information of the operation of a MOS. Electrical characterization by C-V and current-voltage (I-V) measurements at temperatures ranging from 20 to 150 degrees Celsius were performed on the MOS capacitors to examine flatband and threshold voltages, oxide charge, and oxide thickness.

    At elevated temperatures, low frequency C-V curves with threshold voltages of approximately 5 V were obtained for MOS capacitors consisting of aluminum gates, a 30 nm layer of aluminum oxide, and boron doped diamond with acceptor concentration 3.1 x 1017 cm-3. The C-V measurements also showed large variations in flatband voltage for different contacts of the MOS capacitor, indicating the presence of oxide charge. Oxide thickness was also extracted from the C-V measurements, typically showing thicknesses around 15-19 nm.

    Also in this  thesis, an alternative method for reducing the electric field strength around the edges of the contact of a Schottky diode has been examined. This method consists of alternating the geometry by etching the semiconductor where the contact is to be placed. Simulations performed in Comsol Multiphysics showed that a reduction of the field strength of approximately 30 % at the contacts could be achieved by etching the substrate.

  • 49.
    Adsten, Monika
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Solar Thermal Collectors at High Latitudes: Design and performance of non-tracking concentrators2002Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Solar thermal collectors at high latitudes have been studied, with emphasis on concentrating collectors. A novel design of concentrating collector, the Maximum Reflector Collector (MaReCo), especially designed for high latitudes, has been investigated optically and thermally. The MaReCo is an asymmetrical compound parabolic concentrator with a bi-facial absorber. The collector can be adapted to various installation conditions, for example stand-alone, roof- or wall mounted. MaReCo prototypes have been built and outdoor-tested. The evaluation showed that all types work as expected and that the highest annually delivered energy output, 340 kWh/m2, is found for the roof MaReCo. A study of the heat-losses from the stand-alone MaReCo lead to the conclusion that teflon transparent insulation should be placed around the absorber, which decreases the U-value by about 30%.

    A method was developed to theoretically study the projected radiation distribution incident on the MaReCo bi-facial absorber. The study showed that the geometry of the collectors could be improved by slight changes in the acceptance intervals. It also indicated that the MaReCo design concept could be used also at mid-European latitudes if the geometry is changed.

    A novel method was used to perform outdoor measurements of the distribution of concentrated light on the absorber and then to calculate the annually collected zero-loss energy, Ea,corr, together with the annual optical efficiency factor. A study using this method indicated that the absorber should be mounted along the 20º optical axis instead of along the 65º optical axis, which leads to an increase of about 20% in Ea,corr. The same absorber mounting is suggested from heat loss measurements. The Ea,corr at 20º absorber mounting angle can be increased by 5% if the absorber fin thickness is changed from 0.5 to 1 mm and by 13% if two 71.5 mm wide fins are used instead of one that is 143 mm wide. If the Ea,corr for the standard stand-alone MaReCo with 143 mm wide absorber mounted at 65º is compared to that of a collector with a 71.5 mm wide absorber mounted at 20º, the theoretical increase is 38%.

    List of papers
    1. Evaluation of CPC-collector designs for stand-alone, roof- or wall installation
    Open this publication in new window or tab >>Evaluation of CPC-collector designs for stand-alone, roof- or wall installation
    2005 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 79, no 6, p. 638-647Article in journal (Refereed) Published
    Abstract [en]

    An asymmetrically truncated non-tracking compound parabolic concentrator type collector design concept has been developed. The collector type has a bi-facial absorber and is optimised for northern latitudes. The concept is based on a general reflector form that is truncated to fit different installation conditions. In this paper collectors for stand-alone, roof and wall mounting are studied. Prototypes of six different collectors have been built and outdoor tested. The evaluation gave high annual energy outputs for a roof mounted collector, 925 MJ/m2, and a stand-alone collector with Teflon, 781 MJ/m2, at an operating temperature of Top = 75 °C. A special design for roofs facing east or west was also investigated and gave an annual energy output of 349 (east) and 436 (west) MJ/m2 at Top = 75 °C. If a high solar fraction over the year is the objective, a load adapted collector with a high output during spring/fall and a low output during summer can be used. Such a collector had an output of 490 MJ/m2 at Top = 75 °C. Finally a concentrating collector for wall mounting was evaluated with an estimated annual output of 194 MJ/m2 at Top = 75 °C. The concentrator design concept can also be used for concentrators for PV-modules.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-89748 (URN)10.1016/j.solener.2005.04.023 (DOI)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2017-12-14Bibliographically approved
    2. Calorimetric measurements of heat losses from a truncated asymmetric solar thermal concentrator
    Open this publication in new window or tab >>Calorimetric measurements of heat losses from a truncated asymmetric solar thermal concentrator
    2002 (English)In: Solar EnergyArticle in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-89749 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2009-04-29Bibliographically approved
    3. Annually projected solar radiation distribution analysis for optimum design of asymmetric CPC
    Open this publication in new window or tab >>Annually projected solar radiation distribution analysis for optimum design of asymmetric CPC
    2002 (English)In: Solar EnergyArticle in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-89750 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2009-04-29Bibliographically approved
    4. Measurement of radiation distribution on the absorber in an asymmetric CPC collector
    Open this publication in new window or tab >>Measurement of radiation distribution on the absorber in an asymmetric CPC collector
    2004 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 76, no 1-3, p. 199-206Article in journal (Refereed) Published
    Abstract [en]

    A method to estimate the annual collected energy and the annual average optical efficiency factor is suggested. The radiation distribution on the absorber of an asymmetric CPC collector with a flat bi-facial absorber is measured for three different absorber mounting angles using a photo diode. The annual optical efficiency factors and a relative measure of the annual collected energy are determined for collectors with the absorber fin thickness 0.5 and 1 mm, and for a collector with a teflon convection suppression film mounted around the absorber. With the local optical efficiency factors and the annual incident solar energy distribution considered, the analysis indicates that the energy gain for a mounting angle of 20° is higher than for a collector with 65° absorber mounting angle. The annual collected energy is increased with 6–8% if the absorber fin thickness is increased from 0.5 to 1 mm. The annual average optical efficiency factor is relatively independent of the absorber mounting angle. It was found to be 0.87–0.88 for a collector with a 0.5 mm thick absorber fin and 0.92 for a collector with a 1 mm thick absorber fin or for a collector with 0.5 mm thick absorber fin with a teflon convection suppression film added. The low annual average optical efficiency factor is not caused by the uneven irradiance distribution but by the relatively high UL-values.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-89751 (URN)10.1016/j.solener.2003.08.024 (DOI)
    Conference
    Solar World Congress 2001
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2017-12-14Bibliographically approved
    5. Comparison of the optical efficiency of a wide and a narrow absorber fin in an asymmetric concentrating collector
    Open this publication in new window or tab >>Comparison of the optical efficiency of a wide and a narrow absorber fin in an asymmetric concentrating collector
    (English)Manuscript (Other (popular science, discussion, etc.))
    Identifiers
    urn:nbn:se:uu:diva-89752 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2010-01-14Bibliographically approved
    6. The influence of climate and location on collector performance
    Open this publication in new window or tab >>The influence of climate and location on collector performance
    2002 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 25, no 4, p. 499-509Article in journal (Refereed) Published
    Abstract [en]

    The influence of annual climate variations on the performance of solar thermal collectors in the northern part of Europe has been investigated. The annual solar collector energy output has been calculated with the MINSUN simulation program using hourly, measured climatic data for the years 1983–98 for three cities situated in the south (Lund), central (Stockholm) and north (Luleå) of Sweden. A synthetic year created with the Meteonorm weather simulation program was also used in the simulations. Two solar thermal collectors were modelled: a flat plate solar collector and a tubular vacuum collector, both of commercial standard.

    The thermal energy output is strongly correlated to the annual global irradiation at a horizontal surface. The annual average energy delivered from the flat plate collector was 337 kWh/m2 for Stockholm (337 for Lund and 298 for Luleå), and from the vacuum tube collector 668 kWh/m2 for Stockholm (675 for Lund and 631 for Luleå) at an operating temperature of T=50°C. Maximum deviations from the average value for this 16-year period are around 20% for the flat plate and 15% for the vacuum tube collector, at T=50°C.

    The relation between global irradiation on a horizontal surface and the annually collected thermal energy at a constant operating temperature could be fitted to a linear equation: qu=aG(0°)+bT, where qu is the energy output from the collector, G(0°) the global irradiation at a horizontal surface, T the average temperature of the collector fluid, and a and b fitting parameters in a double linear regression analysis.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-89753 (URN)10.1016/S0960-1481(01)00091-X, (DOI)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2017-12-14Bibliographically approved
    7. Simulation of the influence of tilt and azimuth angles on the collector output of solar collectors at northern latitudes
    Open this publication in new window or tab >>Simulation of the influence of tilt and azimuth angles on the collector output of solar collectors at northern latitudes
    1999 (English)In: Proceedings North Sun conference 1999, Edmonton CanadaArticle in journal (Refereed) Accepted
    Identifiers
    urn:nbn:se:uu:diva-89754 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2009-04-29Bibliographically approved
    8. The impact of optical and thermal properties on the performance of flat plate solar collectors
    Open this publication in new window or tab >>The impact of optical and thermal properties on the performance of flat plate solar collectors
    Show others...
    2000 (English)In: Proceedings Eurosun 2000, Copenhagen, DenmarkArticle in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-89755 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2009-04-29Bibliographically approved
    9. Optical scattering from rough aluminum surfaces
    Open this publication in new window or tab >>Optical scattering from rough aluminum surfaces
    Show others...
    2001 (English)In: J. Applied Optics, Vol. 40, p. 2148-2158Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-89756 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2009-04-29Bibliographically approved
    10. Optical characterization of industrially sputtered nickel-nickel oxide solar selective surface
    Open this publication in new window or tab >>Optical characterization of industrially sputtered nickel-nickel oxide solar selective surface
    2000 (English)In: Solar Energy, Vol. 68, p. 325-328Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-89757 (URN)
    Available from: 2002-04-05 Created: 2002-04-05 Last updated: 2009-04-29Bibliographically approved
  • 50.
    Adsten, Monika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Helgesson, Anna
    Karlsson, Björn
    Evaluation of CPC-collector designs for stand-alone, roof- or wall installation2005In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 79, no 6, p. 638-647Article in journal (Refereed)
    Abstract [en]

    An asymmetrically truncated non-tracking compound parabolic concentrator type collector design concept has been developed. The collector type has a bi-facial absorber and is optimised for northern latitudes. The concept is based on a general reflector form that is truncated to fit different installation conditions. In this paper collectors for stand-alone, roof and wall mounting are studied. Prototypes of six different collectors have been built and outdoor tested. The evaluation gave high annual energy outputs for a roof mounted collector, 925 MJ/m2, and a stand-alone collector with Teflon, 781 MJ/m2, at an operating temperature of Top = 75 °C. A special design for roofs facing east or west was also investigated and gave an annual energy output of 349 (east) and 436 (west) MJ/m2 at Top = 75 °C. If a high solar fraction over the year is the objective, a load adapted collector with a high output during spring/fall and a low output during summer can be used. Such a collector had an output of 490 MJ/m2 at Top = 75 °C. Finally a concentrating collector for wall mounting was evaluated with an estimated annual output of 194 MJ/m2 at Top = 75 °C. The concentrator design concept can also be used for concentrators for PV-modules.

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