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  • 1.
    Ahmad, Jawad
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Screen Printed Large Area Sensors for Pressure Distribution Monitoring in Wheelchairs2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    A sedentary lifestyle can induce health related problems including pressure ulcers. Pro­longed sitting inadequacies constitute a risk for pressure ulcer to many individuals, in particular people with disabilities and re­duced mobility. The measurement of distributed pressure and detection of irregular sitting postures are essential in prevention of the risk of developing pres­sure ulcers.

    In this thesis, a screen-printed pressure sensor for a large area is presented, with the objective of measuring the distributed pressure of a seated per­son in a wheelchair. The conductors and interdigital patterns are printed with silver-based ink. A blend of a non-conductive and a low resis­tive ink is used for customized resistance for an optimal sensing range of the pressure sensor. The effect of moisture and temper­ature are realized in an environment chamber. For characterization, other key performance tests such as repeatability, drift and flexibility are carried out. The surface morphology is carried out for structural analysis of printed samples. The sensor data is acquired and processed using an 8-bit ATmega-2560 micro­controller and wirelessly transmitted to a PC for post-processing, storage and analysis. For real-time data presentation of dis­tributed pressure points, a GUI has been developed to display the values ob­tained from the large area sensor. The detection of four sit­ting pos­tures; forward leaning, backward leaning, left leaning and right leaning along with a normal sitting posture is attained. An analysis for stretchable printed tracks has been conducted to investigate the changes in electrical resistance using elon­ga­tion tests, surface morphology and EDS. The optimal curing time and tem­per­ature were investigated to manufacture stretchable conductive tracks.

    In summary, the contributions in this thesis provides an effective approach regarding pressure distribution measurement and recognizing irregular sitting postures for wheelchair users.

  • 2.
    Ahmad, Jawad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Sidén, Johan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Screen Printed Piezoresistive Sensors for Monitoring Pressure Distribution in Wheelchair2019In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 19, no 6, p. 2055-2063Article in journal (Refereed)
    Abstract [en]

    Prolonged sitting inadequacies cause pressure ulcer to many individuals, especially to disadvantaged with reduced mobility. The measurement of distributed pressure and detection of irregular sitting postures is essential for preventing the risk of developing pressure ulcer. In this paper, a pressure sensing system capable of recognizing sitting postures by means of measuring interface pressure through printed pressure sensors is presented. A thin and flexible large area sensor is screen-printed using silver flake and carbon particle inks and comprises 16 sensing elements. For the evaluation of practical usability, the sensor characterization is carried out by conducting stability, repeatability, drift and bending tests. The performance of the sensor is checked under varying environmental conditions. Sitting posture detection accuracy above 80 % is achieved using a classification algorithm for four different sitting postures. Pressure distribution is monitored at a scanning rate of 10 Hz. A low power and small form factor of read-out electronics enables a compact packaging inside the seat cushion. The presented sensor design targets smart wheelchairs, but it is extendable to much larger areas, for example to be used in beds. The proposed sensing system would be of a great assistance for caregivers and health professionals.

  • 3.
    Ahmad, Jawad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Li, Xiaotian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Sidén, Johan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    An Analysis of Screen-Printed Stretchable Conductive Tracks on Thermoplastic Polyurethane2019Data set
    Abstract [en]

    The table is a result from cyclic strain test with 25 % and 50 % elongations of screen-printed stretchable conductive tracks on thermoplastic polyurethane.

  • 4.
    Ahmad, Jawad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Li, Xiaotian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Sidén, Johan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    An Analysis of Screen-Printed Stretchable Conductive Tracks on Thermoplastic Polyurethane2019Conference paper (Other academic)
  • 5.
    Alishah, Rasoul Shalchi
    et al.
    Univ Tabriz, Tabriz, Iran.
    Hasani, Mir Yahya
    Islamic Azad Univ Tabriz, Tabriz, Iran.
    Hosseini, Seyed Hossein
    Univ Tabriz, Tabriz, Iran.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Babalou, Milad
    Univ Tabriz, Tabriz, Iran.
    Analysis and Design of a New Extendable Sepic Converter with High Voltage Gain and Reduced Components for Photovoltaic Applications2019In: 2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC), IEEE, 2019, p. 492-497, article id 8697249Conference paper (Refereed)
    Abstract [en]

    This paper presents a high step-up DC-DC converter which is appropriate for Photovoltaic systems. This topology has been combined from an extended switched-capacitor and a common SEPIC converter. Low components and high-voltage-gain are the main benefits of the introduced topology. Low rate current ripple, easy control and continuous input current are other advantages of the presented structure. Integrating the switched-capacitor with the SEPIC converter leads to increase the output voltage with variable conversion ratio which can be used for a wide range of loads. The switched-capacitor converter provides a constant dc output voltage while the SEPIC converter extracts maximum power of PV panels because it operates under control of duty cycle. Continuous input current is highly suitable for PV applications. The operating principles and steady-state analysis of the suggested topology are discussed in detail. In order to assess the effectiveness of the presented topology, it has been simulated on PSCAD/EMTDC software.

  • 6.
    Allahgholi, Aschkan
    et al.
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Becker, Julian
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Delfs, Annette
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Dinapoli, Roberto
    Paul Scherrer Inst, Villigen, Switzerland.
    Goettlicher, Peter
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Greiffenberg, Dominic
    Paul Scherrer Inst, Villigen, Switzerland.
    Henrich, Beat
    Paul Scherrer Inst, Villigen, Switzerland.
    Hirsemann, Helmut
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Kuhn, Manuela
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Klanner, Robert
    Univ Hamburg, Hamburg, Germany.
    Klyuev, Alexander
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Krueger, Hans
    Univ Bonn, Bonn, Germany.
    Lange, Sabine
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Laurus, Torsten
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Marras, Alessandro
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Mezza, Davide
    Paul Scherrer Inst, Villigen, Switzerland.
    Mozzanica, Aldo
    Paul Scherrer Inst, Villigen, Switzerland.
    Niemann, Magdalena
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Poehlsen, Jennifer
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Schwandt, Joern
    Univ Hamburg, Hamburg, Germany.
    Sheviakov, Igor
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Shi, Xintian
    Paul Scherrer Inst, Villigen, Switzerland.
    Smoljanin, Sergej
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Steffen, Lothar
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Sztuk-Dambietz, Jolanta
    European XFEL, Schenefeld, Germany.
    Trunk, Ulrich
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Xia, Qingqing
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Zeribi, Mourad
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Zhang, Jiaguo
    Paul Scherrer Inst, Villigen, Switzerland.
    Zimmer, Manfred
    Deutsch Elekt Synchrotron, Hamburg, Germany.
    Schmitt, Bernd
    Paul Scherrer Inst, Villigen, Switzerland.
    Graafsma, Heinz
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Deutsch Elekt Synchrotron, Hamburg, Germany.
    The Adaptive Gain Integrating Pixel Detector at the European XFEL2019In: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 26, p. 74-82Article in journal (Refereed)
    Abstract [en]

    The Adaptive Gain Integrating Pixel Detector (AGIPD) is an X-ray imager, custom designed for the European X-ray Free-Electron Laser (XFEL). It is a fast, low-noise integrating detector, with an adaptive gain amplifier per pixel. This has an equivalent noise of less than 1keV when detecting single photons and, when switched into another gain state, a dynamic range of more than 10(4)photons of 12keV. In burst mode the system is able to store 352 images while running at up to 6.5MHz, which is compatible with the 4.5MHz frame rate at the European XFEL. The AGIPD system was installed and commissioned in August 2017, and successfully used for the first experiments at the Single Particles, Clusters and Biomolecules (SPB) experimental station at the European XFEL since September 2017. This paper describes the principal components and performance parameters of the system.

  • 7.
    Allahgholi, Aschkan
    et al.
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Becker, Julian
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Delfs, Annette
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Dinapoli, Roberto
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Göttlicher, Peter
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Graafsma, Heinz
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Greiffenberg, Dominic
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Hirsemann, Helmut
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Jack, Stefanie
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Klyuev, Alexander
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Krüger, Hans
    Universität Bonn, Bonn, Germany.
    Kuhn, Manuela
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Laurus, Torsten
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Marras, Alessandro
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Mezza, Davide
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Mozzanica, Aldo
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Poehlsen, Jennifer
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Shefer Shalev, Ofir
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Sheviakov, Igor
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Schmitt, Bernd
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Schwandt, Jörn
    Universität Hamburg, Hamburg, Germany.
    Shi, Xintian
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Smoljanin, Sergej
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Trunk, Ulrich
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Zhang, Jiaguo
    Paul Scherrer Institut - PSI, Villigen, Switzerland.
    Zimmer, Manfred
    Deutsches Elektronensynchrotron - DESY, Hamburg, Germany.
    Megapixels @ Megahertz – The AGIPD high-speed cameras for the European XFEL2019In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 942, article id 162324Article, review/survey (Refereed)
    Abstract [en]

    The European XFEL is an extremely brilliant Free Electron Laser Source with a very demanding pulse structure: trains of 2700 X-ray pulses are repeated at 10Hz. The pulses inside the train are spaced by 220ns and each one contains up to 1012photons of 12.4keV, while being ≤100fs in length. AGIPD, the Adaptive Gain Integrating Pixel Detector, is a hybrid pixel detector developed by DESY, PSI, and the Universities of Bonn and Hamburg to cope with these properties. It is a fast, low noise integrating detector, with single photon sensitivity (for Eγ⪆6keV) and a large dynamic range, up to 104 photons at 12.4keV. This is achieved with a charge sensitive amplifier with 3 adaptively selected gains per pixel. 352 images can be recorded at up to 6.5MHz and stored in the in-pixel analogue memory and read out between pulse trains. The core component of this detector is the AGIPD ASIC, which consists of 64 × 64 pixels of 200µm×200µm. Control of the ASIC's image acquisition and analogue readout is via a command based interface. FPGA based electronic boards, controlling ASIC operation, image digitisation and 10GE data transmission interface AGIPD detectors to DAQ and control systems. An AGIPD 1Mpixel detector has been installed at the SPB1 experimental station in August 2017, while a second one is currently commissioned for the MID 2 endstation. A larger (4Mpixel) AGIPD detector and one to employ Hi-Z sensor material to efficiently register photons up to Eγ≈25keV are currently under construction. 

  • 8.
    Alqaysi, Hiba
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Lawal, NajeemMid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.Fedorov, IgorMid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.Thörnberg, BennyMid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.O’Nils, MattiasMid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Design Exploration of Multi-Camera Dome2019Conference proceedings (editor) (Refereed)
    Abstract [en]

    Visual monitoring systems employ distributed smart cameras toeffectively cover a given area satisfying specific objectives. Thechoice of camera sensors and lenses and their deployment affectsdesign cost, accuracy of the monitoring system and the ability toposition objects within the monitored area. Design cost can bereduced by investigating deployment topology such as groupingcameras together to form a dome at a node and optimize it formonitoring constraints. The constraints may include coverage area,number of cameras that can be integrated in a node and pixelresolution at a given distance. This paper presents a method foroptimizing the design cost of multi-camera dome by analyzing tradeoffsbetween monitoring constraints. The proposed method can beused to reduce monitoring cost while fulfilling design objectives.Results show how to increase coverage area for a given cost byrelaxing requirements on design constraints. Multi-camera domescan be used in sky monitoring applications such as monitoring windparks and remote air-traffic control of airports where all-round fieldof view about a point is required to monitor.

  • 9.
    Andersson, Henrik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Šuly, Pavol
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Tomas Bata University in Zlin, Zlin, Czech Republic.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Mašlík, Jan
    Tomas Bata University in Zlin, Zlin, Czech Republic.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    PEDOT: PSS thermoelectric generators printed on paper substrates2019In: Journal of Low Power Electronics and Applications, ISSN 2079-9268, Vol. 9, no 2Article in journal (Refereed)
    Abstract [en]

    Flexible electronics is a field gathering a growing interest among researchers and companies with widely varying applications, such as organic light emitting diodes, transistors as well as many different sensors. If the circuit should be portable or off-grid, the power sources available are batteries, supercapacitors or some type of power generator. Thermoelectric generators produce electrical energy by the diffusion of charge carriers in response to heat flux caused by a temperature gradient between junctions of dissimilar materials. As wearables, flexible electronics and intelligent packaging applications increase, there is a need for low-cost, recyclable and printable power sources. For such applications, printed thermoelectric generators (TEGs) are an interesting power source, which can also be combined with printable energy storage, such as supercapacitors. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), or PEDOT:PSS, is a conductive polymer that has gathered interest as a thermoelectric material. Plastic substrates are commonly used for printed electronics, but an interesting and emerging alternative is to use paper. In this article, a printed thermoelectric generator consisting of PEDOT:PSS and silver inks was printed on two common types of paper substrates, which could be used to power electronic circuits on paper. 

  • 10.
    Aranda, Jesus Javier Lechuga
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bader, Sebastian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Oelmann, Bengt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    A space-coiling resonator for improved energy harvesting in fluid power systems2019In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 291, p. 58-67Article in journal (Refereed)
    Abstract [en]

    Pressure fluctuation energy harvesting devices are promising alternatives to power up wireless sensors in fluid power systems. In past studies, classical Helmholtz resonators have been used to enhance the energy harvesting capabilities of these harvesters. Nevertheless, for fluctuations with frequency components in the range of less than 1000 Hz, the design of compact resonators is difficult, mostly for their poor acoustic gain. This paper introduces a space-coiling resonator fabricated using 3D printing techniques. The proposed resonator can achieve a better acoustic gain bounded by a small bulk volume compared to a classic Helmholtz resonator, improving the energy harvesting capabilities of pressure fluctuation energy harvesters. The resonator is designed and evaluated using finite-element-method techniques and examined experimentally. Three space-coiling-resonators are designed, manufactured and compared to classic Helmholtz resonators for three frequencies: 280 Hz, 480 Hz and 920 Hz. This work displays the possibility of compact, high-performance pressure fluctuation energy harvesters and the advantages of the space-coiling printed resonators to enhance the harvesting performance.

  • 11.
    Ashraf, Shakeel
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Mattsson, Claes
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Fabrication and characterization of a SU8-epoxy membrane based thermopile detector with an integrated multilayered absorber structure for the mid-IR region2019In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 19, no 11, p. 4000-4007Article in journal (Refereed)
    Abstract [en]

    This paper reports on the fabrication and characterization of a thermopile detector with an integrated mid-infrared absorber structure. The fabricated absorber structure has shown an absorption of more than 95% in the wavelength range of 3.2 – 5.47 μm. The detector was fabricated with standard cleanroom process techniques and equipment. The serial resistance was measured at about 315 kΩ at room temperature. The photosensitivity of the detector was characterized for a signle wavelength (4.26 µm) and a band of wavelength ranging from 2.5 –5.5 µm through two different measurement setups. In the first measurement setup, the photosensitivity was estimated at 57.5 V·mm2·W-1 through a MEMS-based infrared radiation source and with an optical band-pass filter of wavelength 4.26µm. The following characterization was performed to characterise the photosensitivity of the detector in a broader wavelength range. This measurement was taken using a monochromator setup utilizing a reference photodetector for calculations of the optical power of the infrared source. The photosensitivity and the specific detectivity (D*) of the fabricated detector were measured to values of 30-92 V·W-1 and 8.0×107-2.4×108 cm·Hz1/2·W-1, respectively, in the wavelength range of 2.8 – 5 µm. The time constant was estimated to around 21 ms

  • 12.
    Ashraf, Shakeel
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Niskanen, Ilpo
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. University of Oulu, Finland.
    Kanyathare, Boniphace
    Electronics and Telecommunications Department, Dar es salaam Institute of Technology, Tanzania.
    Vartiainen, Erik
    LUT School of Engineering Science, Lappeenranta University of Technology, Finland.
    Mattsson, Claes
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Heikkilä, Rauno
    Faculty of Technology, Structures and Construction Technology, University of Oulu, Finland.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Determination of complex refractive index of SU-8 by Kramers-Kronig dispersion relation method at the wavelength range 2.5 – 22.0 μm2019In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 224, p. 309-311Article in journal (Refereed)
    Abstract [en]

    Accurate determination of the complex refractive index of SU-8 epoxy has significant for the wide variety of applications in optical sensor technology at IR range. The complex refractive index of SU-8 is determined by recording the transmission of light spectra for the wavelength range of 2.5 – 22.0 μm.  The data analysis is based on the Kramers-Kronig dispersion relation method. The method has several merits, such as ease of operation, non-contact technique, measurement accuracy, and rapid measurement. The present method is not restricted to the case of SU-8 but it is also proposed to be applicable across a broad range of applications, such as assessment of the optical properties of paints and biomedical samples.

  • 13.
    Bader, Sebastian
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Ma, Xinyu
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Oelmann, Bengt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    One-diode photovoltaic model parameters at indoor illumination levels – A comparison2019In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 180, p. 707-716Article in journal (Refereed)
    Abstract [en]

    Models of photovoltaic devices are used to compare the properties of photovoltaic cells and panels, and to predict their I-V characteristics. To a large extent, modeling methods are based on the one-diode equivalent circuit. Although much research exists on the implementation and evaluation of these methods for typical outdoor conditions, their performance at indoor illumination levels is largely unknown. Consequently, this work performs a systematic study of methods for the parameter extraction of one-diode models under indoor conditions. We selected, reviewed and implemented commonly used methods, and compared their performance at different illumination levels. We have shown that most methods can achieve good accuracies with extracted parameters regardless of the illumination condition, but their accuracies vary significantly when the parameters are scaled to other conditions. We conclude that the physical interpretation of extracted parameters at low illumination is to a large extent questionable, which explains errors based on standard scaling approaches. 

  • 14.
    Balliu, Enkeleda
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    A compact, single-frequency, high-power, SBS-free, Yb-doped single-stage fiber amplifier2019In: Proceedings of SPIE - The International Society for Optical Engineering / [ed] W. Andrew Clarkson and Ramesh K. Shori, SPIE - International Society for Optical Engineering, 2019, Vol. 10896, p. 6pp-, article id 1089618Conference paper (Refereed)
    Abstract [en]

    Interest in compact, single-frequency fiber amplifier has increased within many scientific and industrial applications. The main challenge is the onset of nonlinear effects, which limit their power scaling. Here we demonstrate a compact, high-power, single-frequency, polarization-maintaining, continous-wave fiber amplifier using only one amplification stage. We developed the fiber amplifier using a master oscillator fiber amplifier architecture, where a low-noise, single-frequency, solid-state laser operating at 1064 nm was used as a seed source. We evaluated the amplifier's performance by using several state-of-the-art, small-core, Ytterbium (yb)-doped fibers, as well as an in-house-made, highly Yb-doped fiber. An output power of 82 W was achieved with no sign of stimulated Brillouin scattering. A good beam quality and a polarization extinction ratio (PER) of > 25 dB were achieved. The compact fiber amplifier can be a competitive alternative to multi stage designed fiber amplifiers.

  • 15.
    Balliu, Enkeleda
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Thontakudi, Anjali
    Monta Vista High School, Cupertino, CA USA.
    Knall, Jenny M.
    Stanford University, Stanford, CA USA.
    Digonnet, Michel J. F.
    Stanford University, Stanford, CA USA.
    Predictive comparison of anti-Stokes fluorescence cooling in oxide and non-oxide fiber hosts doped with Er3+, Pr3+, or Yb3+2019In: Proceedings of SPIE - The International Society for Optical Engineering: Photonic Heat Engines: Science and Applications, SPIE - International Society for Optical Engineering, 2019, Vol. 10936, article id 109360JConference paper (Refereed)
    Abstract [en]

    A comprehensive study was performed to quantify anti-Stokes-fluorescence (ASF) cooling in fibers of various host compositions (telluride, fluorozirconates, fluorophosphates, phosphates, and chalcogenides) doped with Yb3+ or Er3+. Published expressions were used to calculate the maximum heat that can be extracted per unit length and time from a single-mode fiber in the limit of negligible absorptive loss, and the associated cooling efficiency. These expressions consider host- and ion-dependent parameters, namely the absorption and emission cross-section spectra, the radiative and nonradiative lifetimes, and the critical concentration for quenching. Using these expressions with published values for these parameters, the maximum extractable heat was calculated for a large-mode-area fiber (NA = 0.05) doped with either Yb3+ or Er3+ in a variety of hosts. The results show that for a given ion, the maximum heat that can be extracted depends strongly on the host due to the strong dependence of quenching on host composition. In contrast, the cooling efficiency (ratio of extracted heat to pump power absorbed) depends very weakly on the host. The cooling efficiency is also almost twice as high for Er3+ (average of 3.8%) than for Yb3+ (average of 2.2%) due to the larger gap between the pump and mean fluorescence energy in Er3+. Of the limited number of materials for which a full set of data was found in the literature, the highest extractable heat for Yb3+ is in phosphate (-51.5 mW/m), and for Er3+ is in chalcogenide (-10.3 mW/m). This work provides a simple methodology to evaluate the quantitative cooling performance of these and other rare-earth ions in any amorphous host, a procedure that should guide researchers in the selection of optimum materials for ASF cooling of fibers.

  • 16.
    Croci, Gabriele
    et al.
    Univ Milano Bicocca, Milan, Italy.
    Muraro, Andrea
    CNR, Milan, Italy.
    Cippo, Enrico Perelli
    CNR, Milan, Italy.
    Grosso, Giovanni
    CNR, Milan, Italy.
    Hoglund, Carina
    European Spallat Source ESS AB, Lund.
    Hall-Wilton, Richard
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. European Spallat Source ESS AB, Lund.
    Murtas, Fabrizio
    Ist Nazl Fis Nucl, Frascati, Italy.
    Raspino, Davide
    Rutherford Appleton Lab, Didcot, Oxon, England.
    Robinson, Linda
    European Spallat Source ESS AB, Lund.
    Rhodes, Nigel
    Rutherford Appleton Lab, Didcot, Oxon, England.
    Rebai, Marica
    CNR, Milan, Italy.
    Schooneveld, Erik
    Rutherford Appleton Lab, Didcot, Oxon, England.
    Defendi, Ilario
    TUM, Garching, Germany.
    Zeitelhack, Karl
    TUM, Garching, Germany.
    Tardocchi, Marco
    CNR, Milan, Italy.
    Gorini, Giuseppe
    Univ Milano Bicocca, Milan, Italy.
    I-BAND-GEM: a new way for improving BAND-GEM efficiency to thermal and cold neutrons2019In: The European Physical Journal Plus, ISSN 2190-5444, E-ISSN 2190-5444, Vol. 134, no 4, article id 166Article in journal (Refereed)
    Abstract [en]

    .The BAND-GEM detector represents one of the novel thermal neutron detection devices that have been developed in order to fulfil the needs of high intensity neutron sources that, like ESS (the European Spallation Source), will start operation in the next few years. The first version of this detector featured a detection efficiency of about 40% for neutrons with a wavelength of 4 angstrom, a spatial resolution of about 6mm and a rate capability in the order of some MHz/cm(2). The novelty of this device is represented by an improved 3D converter cathode (10 cm thick) based on (B4C)-B-10-coated aluminum grids positioned in a controlled gas mixture volume put on top of a Triple GEM amplifying stage. The position where the neutron interacts in the converter depends on their energy and it was observed that the first version of the detector would suffer from an efficiency decrease for long (>5 angstrom) neutron wavelength. This paper describes how the new 3D cathode allowed improving the detection efficiency at long neutron wavelengths while keeping all the benefits of the first BAND-GEM version.

  • 17.
    Dian, E.
    et al.
    Hungarian Acad Sci, Budapest, Hungary; European Spallat Source ESS ERIC, Lund; Budapest Univ Technol & Econ, Budapest, Hungary.
    Kanaki, K.
    European Spallat Source ESS ERIC, Lund.
    Khaplanov, A.
    European Spallat Source ESS ERIC, Lund.
    Kittelmann, T.
    European Spallat Source ESS ERIC, Lund.
    Zagyvai, P.
    Hungarian Acad Sci, Budapest, Hungary; Budapest Univ Technol & Econ, Budapest, Hungary.
    Hall-Wilton, Richard
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. European Spallat Source ESS ERIC, Lund.
    Suppression of intrinsic neutron background in the Multi-Grid detector2019In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 14, article id P01021Article in journal (Refereed)
    Abstract [en]

    One of the key requirements for neutron scattering instruments is the Signal-toBackground ratio (SBR). This is as well a design driving requirement for many instruments at the European Spallation Source (ESS), which aspires to be the brightest neutron source of the world. The SBR can be effectively improved with background reduction. The Multi-Grid, a large-area thermal neutron detector with a solid boron carbide converter, is a novel solution for chopper spectrometers. This detector will be installed for the three prospective chopper spectrometers at the ESS. As the Multi-Grid detector is a large area detector with a complex structure, its intrinsic background and its suppression via advanced shielding design should be investigated in its complexity, as it cannot be naively calculated. The intrinsic scattered neutron background and its effect on the SBR is determined via a detailed Monte Carlo simulation for the Multi-Grid detector module, designed for the CSPEC instrument at the ESS. The impact of the detector vessel and the neutron entrance window on scattering is determined, revealing the importance of an optimised internal detector shielding. The background-reducing capacity of common shielding geometries, like side-shielding and end-shielding is determined by using perfect absorber as shielding material, and common shielding materials, like B4C and Cd are also tested. On the basis of the comparison of the effectiveness of the different shielding topologies and materials, recommendations are given for a combined shielding of the Multi-Grid detector module, optimised for increased SBR.

  • 18.
    Edblom, Hampus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Analys av reläskyddsinställningar för jordfelsskydd2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Well-adjusted relay protection for electrical substations is a necessity for personal safety and reliable operation. The aim of the report is to investigate whether non-directional protection with signaling alone is sufficient to protect the facility being investigated, and if directional protection has the advantage of improving fault detection, reducing the risk of unnecessary operation or reducing the function time. The facility under investigation is a 6.3 kV industrial network with resistance grounding. The report checks the insulation values and current tolerances for the equipment, which are then compared with calculated voltages and currents at single-phase earth faults. The report also briefly describes directional protection and its functions in relation to the issue of the potential benefit of directional protection. The result was that overvoltages due to earth faults are not a problem, but the fault current through the neutral point resistance is too large for signaling alone. In the case of earth faults with very low fault impedance, the neutral point resistance can handle the fault current for 30 seconds. After which the heat development results in the neutral point resistance being disconnected and the facility being isolated from the neutral point. According to the study, targeted protection is not needed in a facility like this. This is based on the fact that the cable paths are too short to cause capacitive currents large enough to cause unnecessary operation in non-directional protection, and that the network structure does not generate currents in unexpected directions. The result of the report shows that non-directional protection is sufficient, but that the operation function should be changed to tripping of faulty circuits

  • 19.
    Engholm, Magnus
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hammarling, Krister
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Sandberg, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. RISE Acreo.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    A Bio-Compatible Fiber Optic pH Sensor Based on a Thin Core Interferometric Technique2019In: Photonics, ISSN 2304-6732, Vol. 6, no 1, article id 11Article in journal (Refereed)
    Abstract [en]

    There is an increasing demand for compact, reliable and versatile sensor concepts for pH-level monitoring within several industrial, chemical as well as bio-medical applications. Many pHsensors concepts have been proposed, however, there is still a need for improved sensor solutionswith respect to reliability, durability and miniaturization but also for multiparameter sensing. Here wepresent a conceptual verification, which includes theoretical simulations as well as experimentalevaluation of a fiber optic pH-sensor based on a bio-compatible pH sensitive material not previouslyused in this context. The fiber optic sensor is based on a Mach-Zehnder interferometric technique,where the pH sensitive material is coated on a short, typically 20-25 mm thin core fiber splicedbetween two standard single mode fibers. The working principle of the sensor is simulated by usingCOMSOL Multiphysics. The simulations are used as a guideline for the construction of the sensorsthat have been experimentally evaluated in different liquids with pH ranging from 1.95 to 11.89. The results are promising, showing the potential for the development of bio-compatible fiber optic pH sensor with short response time, high sensitivity and broad measurement range. The developedsensor concept can find future use in many medical- or bio-chemical applications as well as inenvironmental monitoring of large areas. Challenges encountered during the sensor developmentdue to variation in the design parameters are discussed.

  • 20.
    Gaynullin, Bakhram
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Engineer.
    Hummelgård, Christine
    Rödjegård, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Mattsson, Claes
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media. Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics. Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Efficient pressure compensation of low-cost NDIR sensors for environmental studiesIn: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748Article in journal (Refereed)
    Abstract [en]

    Using commercial low-cost NDIR gas sensors for atmospheric measurements requires pressure compensation for an accurate readout; this is normally not implemented. Herein, we present an efficient pressure compensation method. This includes a lab test system for studying pressure dependence in accuracy-demanding applications to introduce interpolation in the concentration dimension. A two-dimensional algorithm allows compensation in the entire pressure-concentration space using a minimum of data. The obtained compensation parameters are used for the recalculation of the measured concentrations to true molar fractions valid for standard atmospheric pressure.

  • 21.
    Hagerud, Sanna
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Personsäkerhet vid översvämning av lågspänningsanläggningar: Inledande undersökningar2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As a part of the work by the Swedish Electrical Safety Authority to adapt rules and regulations to future climate changes, this thesis investigate the present knowledge about personal safety during flooding of low voltage distribution systems and private electrical utilities. It also investigate if common electrical equipment and distribution boxes leak current when immersed in water. Information seeking was done by searches in article databases. The search results mainly concerned personal safety in other types of  environments with water and electric facilities, mostly boats and marinas. Measurements on a selection of electric equipment and distrbution boxes immersed in water, representative of surface water, showed that all but one produced leak current in the water to a ground electrode at a distance of 1,2 m. Only a metal distribution box with grounded casing and closed door did not produce leak current in the water. Most of the leak currents exceeded limits for dangerous current levels. Dangerous potenatials where recorded in the water surrounding the equipment. Simulations with computer programs showed that the distribution of the electrical field could be greatly affected by the particular environment, consisting of different metal structures common in buildings and different conductivity in walls and floor. It confirms that current split and distribution of electric fields i real flooded environments are hard to predict.

  • 22.
    Haller, Stefan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    MOSFET enabled low-voltage high-current DC traction drive: a pioneering concept for battery electric vehicles2019Licentiate thesis, comprehensive summary (Other academic)
  • 23.
    Haller, Stefan
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Cheng, Peng
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Oelmann, Bengt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    A 2.5 v 600 a mosfet-based DC traction motor2019In: Proceedings of the IEEE International Conference on Industrial Technology, Institute of Electrical and Electronics Engineers (IEEE), 2019, p. 213-218, article id 8755146Conference paper (Refereed)
    Abstract [en]

    A high copper fill factor allows reducing the resistive losses responsible for more than 50 % of the losses in today's most commonly used electrical motors. Single-turn windings achieve a copper fill factor close to one. Furthermore, they do not suffer from turn to turn faults and provide a low thermal resistance between winding and stator. The reduced EMF of single-turn winding configurations promotes the use of extra-low voltage high current MOSFETs. Rapid development of these MOSFETs allows reversing common design principles to explore new applications, such as battery electric traction drives. This paper presents a 2.5 V 1 kW MOSFET driven 13-phase permanent magnet DC motor with a single-turn winding configuration. The motor prototype with a copper fill factor of 0.84 was tested with continuous drive currents up to 600 A. The measured torque-efficiency map shows that such a high-current concept with voltages below 60 V is feasible using today's extremely low-voltage high current semiconductors. Due to the rapid development of such switches, there is great potential in this concept for further improvements. This work presents a small-scale version of the high-current drive, which is part of the development of an extra-low voltage traction drive concept. 

  • 24.
    Hammarling, Krister
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hydrogel-based pH-sensors: Development and characterisation of optical and electrical pH sensors based on stimuli-responsive hydrogels2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The ability to measure the chemical parameter pH is of high importance in many areas. With new government regulations and evolving markets, there is a strong motivation for improving such measurements and conducting research on new types of pH sensors and sensor materials. Stimuli-responsive hydrogels (a group of polymers) have attracted a lot of attention in recent decades, due to their ability to be customized to suit many applications. One specific area where they have attracted attention is pH sensor technology.

    Two stimuli-responsive hydrogels are used in this thesis. One is a non-toxic hydrogel, 1,4-acryl-terminated oligo(beta-amino esters) (1,4-AOBAE). Although it was previously used in drug- and DNA- delivery systems, it has not (to my knowledge) been used in a sensor configuration, and thus it is interesting to study. The second hydrogel, 1,3-acryl-terminated oligo(beta-amino esters) (1,3-AOBAE), is an improved variant of the first one. This improved hydrogel was synthesized because the original hydrogel crystallizes at room temperature, which meant that it was not optimal for various coating techniques. This hydrogel was characterized and verified for pH responsivity in two sensor configurations: electrical and optical. Designing a hydrogel for a specific application can be a complex procedure due to the many synthesizing parameters. For example, increasing a hydrogel's mechanical strength by introducing a higher degree of cross linking, leads to a smaller mesh size, which in turn leads to a lower diffusion rate and less solution absorption. The two hydrogels examined in this thesis respond to pH changes by absorbing or desorbing water; this change in the hydrogel's water content also changes its effective refractive index and permittivity. These changes can be measured using optical or electrical sensor systems. Three types of sensor systems were used in this thesis to verify the hydrogel's pH response and to ensure that they are suitable for use in thin-film techniques on various substrates (e.g. glass and plastic). The experimental results prove that these hydrogels are suitable for use in both electrical and optical sensor configurations. For electrical systems, a pH range of approximately 3-12 was achieved, and for optical, the range was approximately 2-12. These ranges can likely be improved, as the sensor film delaminated from the substrate at low pHs due to adhesion problems and as measurements above 12 were not conducted.

    The findings of this thesis could, after more research, have strong implications for the development of improved pH-sensor configurations, especially for medical and healthcare applications and in environmental monitoring.

  • 25.
    Hammarling, Krister
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Sandberg, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. RISE Acreo AB, Bredgatan 33, 601 17 Norrköping, Sweden.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Broad-Range Hydrogel-Based pH Sensor with Capacitive Readout Manufactured on a Flexible Substrate2018In: Chemosensors, ISSN 2227-9040, Vol. 6, no 3, p. 15article id 30Article in journal (Refereed)
    Abstract [en]

    Environmental monitoring of land, water and air, is an area receiving greater attention because of human health and safety concerns. Monitoring the type of pollution and concentration levels is vital, so that appropriate contingency plans can be determined. To effectively monitor the environment, there is a need for new sensors and sensor systems that suits these type of measurements. However, the diversity of sensors suitable for low, battery powered- and large area sensor systems are limited. We have manufactured and characterized a flexible pH sensor using laser processing and blade coating techniques that is able to measure pH between 2.94 and 11.80. The sensor consists of an interdigital capacitance with a pH sensitive hydrogel coating. Thin sensors can reach 95% of their final value value within 3 min, and are stable after 4 min. Good repeatability was achieved in regard to cycling of the sensor with different pH and multiple measurements from dry state. We have also studied the relation between an interdigital capacitance penetration depth and hydrogels expansion. We believe that our passive sensor is suitable to be used in low power and large area sensor networks.

  • 26.
    Hasselgren, Lena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Kartläggning av Tekniska verkens kraftvärmeverksanläggning KV61: En kartläggning av energiförbrukningen och en kostnads- och energieffektivitetsberäkning för ett byte av befintlig belysning till LED-belysning2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 27.
    Kronander, Kristoffer
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bortom melodi och harmoni: det beväpnande ljudet: Om ljud som vapen och sonisk krigsföring2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete undersöker hur soniska vågor kan användas som vapen. Särskild vikt läggs vid att

    förstå hur ljudet avtäcktes från att vara en osynlig och hämningslös energi till att bli en fysiskt

    producerande våldsam kraft under den megafoniska eran och efter. Uppsatsen argumenterar för

    att soniska vapen måste föregås av avancerad teknologisk utveckling samt ett intresse för att föra

    ett annat typ av krig, utan dödsfall och skjutvapen. Flera exempel ges som visar att ljudvapen

    också ofta används för att kontrollera en population. Sonisk krigsföring fastställs till att innefatta

    användandet av psykologisk, våldsam och fysisk akustisk kraft för att alternera eller påverka

    psykiska och fysiska aspekter hos en population, kropp eller folkmassa.

  • 28.
    Krug, Silvia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bader, Sebastian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Oelmann, Bengt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    O'Nils, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Suitability of Communication Technologies for Harvester-Powered IoT-Nodes2019In: IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS, Institute of Electrical and Electronics Engineers (IEEE), 2019, article id 8758042Conference paper (Refereed)
    Abstract [en]

    The Internet of Things introduces Internet connectivity to things and objects in the physical world and thus enables them to communicate with other nodes via the Internet directly. This enables new applications that for example allow seamless process monitoring and control in industrial environments. One core requirement is that the nodes involved in the network have a long system lifetime, despite limited access to the power grid and potentially difficult propagation conditions. Energy harvesting can provide the required energy for this long lifetime if the node is able to send the data based on the available energy budget. In this paper, we therefore analyze and evaluate which common IoT communication technologies are suitable for nodes powered by energy harvesters. The comparison includes three different constraints from different energy sources and harvesting technologies besides several communication technologies. Besides identifying possible technologies in general, we evaluate the impact of duty-cycling and different data sizes. The results in this paper give a road map for combining energy harvesting technology with IoT communication technology to design industrial sensor nodes. 

  • 29.
    Krug, Silvia
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    O'Nils, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Modeling and Comparison of Delay and Energy Cost of IoT Data Transfers2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 58654-58675Article in journal (Refereed)
    Abstract [en]

    Communication is often considered as the most costly component of a wireless sensor node. As a result, a variety of technologies and protocols aim to reduce the energy consumption for the communication especially in the Internet of Things context. In order to select the best suitable technology for a given use case, a tool that allows the comparison of these options is needed. The goal of this paper is to introduce a new modular modeling framework that enables a comparison of various technologies based on analytical calculations. We chose to model the cost for a single data transfer of arbitrary application data amounts in order to provide flexibility regarding the data amount and traffic patterns. The modeling approach covers the stack traversal of application data and thus in comparison to other approaches includes the required protocol overhead directly. By applying our models to different data amounts, we are able to show tradeoffs between various technologies and enable comparisons for different scenarios. In addition, our results reveal the impact of design decisions that can help to identify future development challenges.

  • 30.
    Lechuga Aranda, Jesus Javier
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Interfaces In Hydraulic Pressure Energy Harvesters2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The fourth industrial revolution is here and with it a tidal wave of challenges for its prosperous implementation. One of the greatest challenges frustrating the development of the internet of things, and hence the next industrial revolution, is the powering of wireless sensors, as these depend on batteries with a limited lifetime. Recent advances have shown that energy harvesting technologies can be employed to extend the lifetime of batteries and ultimately replace them, thus facilitating the deployment of autonomous self-powered sensors, key components of the internet of things.

    Energy harvesting is the process of capturing ambient energy and convertingit into electric power. For energy harvesting devices it is crucial that the transduction of energy is as efficient as possible, meaning that the methods for capturing, interfacing and converting the ambient energy should be understood and characterized for every application. This thesis investigates the harvesting of the energy found in pressure fluctuations in hydraulic systems, a widely used power transmission system used in the industry and consumer applications; the focus is on the fluid interface and energy focusing methods.

    In summary, the contributions in this thesis show that the methods for converting pressure fluctuations in hydraulic systems to electrical power depend on the hydraulic system environment, in essence, the static pressure and the frequency of the pressure fluctuations. The results can serve as a starting point in the research, design, and development of hydraulic pressure energy harvesters.

  • 31.
    Ma, Xi
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    One-diode photovoltaic model parameter extraction based on Soft-Computing Approaches2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Thesis explores the question of whether one-diode model can be extracted using soft-computing approaches based on indoor conditions. In thesis, three algorithms were selected using MATLAB for implementation, analysis and comparison. Thesis has proved that under indoor conditions, all three algorithms can accurately extract photovoltaic parameters under most illumination levels, but the extracted photovoltaic parameters cannot satisfy the physical meaning of photovoltaic parameters.

  • 32.
    Margato, L. M. S.
    et al.
    Univ Coimbra, Dept Fis, LIP Coimbra, Rua Larga, P-3004516 Coimbra, Portugal..
    Morozov, A.
    Univ Coimbra, Coimbra, Portugal.
    Blanco, A.
    Univ Coimbra, Coimbra, Portugal.
    Fonte, P.
    Univ Coimbra, Coimbra, Portugal; Coimbra Polytech ISEC, Coimbra, Portugal.
    Fraga, F. A. F.
    Univ Coimbra, Coimbra, Portugal.
    Guerard, B.
    ILL Inst Laue Langevin, Grenoble, France.
    Hall-Wilton, Richard
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. European Spallat Source ERIC ESS, Lund.
    Höglund, C.
    European Spallat Source ERIC ESS, Lund; Linköping Univ, Linköping.
    Mangiarotti, A.
    Univ Sao Paulo, Sao Paulo, Brazil.
    Robinson, L.
    European Spallat Source ERIC ESS, Lund.
    Schmidt, S.
    European Spallat Source ERIC ESS, Lund; IHI Ionbond AG, Olten, Switzerland.
    Zeitelhack, K.
    Tech Univ Munich, Garching, Germany.
    Boron-10 lined RPCs for sub-millimeter resolution thermal neutron detectors: Feasibility study in a thermal neutron beam2019In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 14, no 1, article id P01017Article in journal (Refereed)
    Abstract [en]

    The results of an experimental feasibility study of a position sensitive thermal neutron detector based on a resistive plate chamber (RPC) are presented. The detector prototype features a thin-gap (0.35 mm) hybrid RPC with an aluminium cathode and a float glass anode. The cathode is lined with a 2 mu m thick (B4C)-B-10 neutron converter enriched in B-10. A detection efficiency of 6.2% is measured at the neutron beam (lambda = 2.5 angstrom) for normal incidence. A spatial resolution better than 0.5 mm FWHM is demonstrated.

  • 33.
    Marras, Alessandro
    et al.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Wunderer, Cornelia
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Correa, Jonathan
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Boitrelle, Benjamin
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany; SOLEIL Synchrotron, Saint Aubin, France.
    Goettlicher, Peter
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Kuhn, Manuela
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Krivan, Frantisek
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Lange, Sabine
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Okrent, Frank
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Shevyakov, Igor
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Supra, Joshua
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Tennert, Maximilian
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Zimmer, Manfred
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Guerrini, Nicola
    cience & Technology Faculties (STFC), Didcot, U.K; Rutherford Appleton Laboratory (RAL), Didcot, U.K.
    Marsh, Ben
    cience & Technology Faculties (STFC), Didcot, U.K; Rutherford Appleton Laboratory (RAL), Didcot, U.K.
    Sedgwick, Iain
    cience & Technology Faculties (STFC), Didcot, U.K; Rutherford Appleton Laboratory (RAL), Didcot, U.K.
    Cautero, Guiseppe
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Giuressi, Dario
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Khromova, Antastasya
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Menk, Ralf
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Pinaroli, Giovanni
    ELETTRA Sincrotrone Trieste, Trieste, Italy; Udine University, Udine, Italy.
    Stebel, Luigi
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Greer, Alan
    Diamond Light Source (DLS), Didcot, U.K.
    Nicholls, Tim
    Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Pedersen, Ulrik
    Pohang Accelerator Lab (PAL), Pohang, South Korea.
    Tartoni, Nicola
    Pohang Accelerator Lab (PAL), Pohang, South Korea.
    Hyun, Hyo Jung
    SOLEIL Synchrotron, Saint Aubin, France.
    Kim, Kyung Sook
    SOLEIL Synchrotron, Saint Aubin, France.
    Rah, Seung Yu
    SOLEIL Synchrotron, Saint Aubin, France.
    Graafsma, Heinz
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; Center for Free Electron Laser Science (CFEL), Hamburg, Germany.
    Percival: A soft x-ray imager for synchrotron rings and free electron lasers2019In: AIP Conference Proceedings, American Institute of Physics (AIP), 2019, Vol. 2054, article id 060060Conference paper (Refereed)
    Abstract [en]

    In this paper, we are presenting the Percival detector, a monolithic CMOS Imager for detection of soft x-rays in Synchrotron Rings and Free Electron Lasers. The imager consists in a 2D array of many (2M) small (27um pitch) pixels, without dead or blind zones in the imaging area. The imager achieves low noise and high dynamic range by means of an adaptive-gain in-pixel circuitry, that has been validated on prototypes. The imager features on-chip Analogue-to-Digital conversion to 12+1 bits, and has a readout speed which is compatible with most of Free Electron Laser Facilities. For direct detection of low-energy x-rays, the imager is back-illuminated and post-processed to achieve 100% fill factor. 

  • 34.
    Mooshtak, Benjamin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Inverkan av laddstolpar för elfordon i Jönköpings Energi elnät2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to Global EV forecasts, a sharp increase in electric cars is ex-pected by 2030, both of which will increase in Sweden and the rest of the world. In Sweden, the number of electric vehicles are expected to increase to 2.5 million, which means that 50% of the vehicles in traffic will be elec-tricall vechiles. According to our calculations and taking into account the population growth, the city Jonkoping will have 36,000 electric cars by 2030. This means that approximately 50% of motorists in 2030 will need to access to electrical charging outlets.

    This predicted increase in electric vehicles implies that more car owners will need to charge their vehicles and this need implies an increased strain on the electricity grid. Load instability can result in poor electrical quality in the form of overtones, flickering, voltage changes, interruptions, tran-sients and unsymmetrical voltage.

    This study analyzes Jonkoping Energi's electricity network and how the electricity grid is affected by an increase in electric vehicles. The survey focuses on multi-dwelling buildings, rural areas and residential areas in Jönköping and in so far as to be able to compare the electricity grid ca-pacity in these areas. The study assumes that the electricity grid is ex-pected to be affected when the charging power reaches 3.7 KW.

    In order to find a solution to the problem, simulations have been made using NIS-oriented software dpPower. Then, using calculation method that is suitable in the different stations is selected. This is done by study-ing load calculations, voltage levels and the load on transformers and the line currents in that area, to see how a 50% usage of electrically powered vehicles affects the power grid.

    The results from the measurements and simulations of the charging sta-tions in all four areas show that Jönköpings Energi should take into ac-count the charging of electric cars when redimensioning their electricity networks. It is also necessary that the phases be distributed among cus-tomers during charging in order to reduce overload in 2030.

    Alternative methods for examining the charging of electric vehicles are as follows:

    • By monitoring how electric car charging behavior looks at different times in order to reduce it by using different solution methods, like the pricing methods used in California and Norway.

  • 35.
    Niskanen, Ilpo
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. University of Oulu, Oulu, Finland.
    Forsberg, Viviane
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. KTH.
    Zakrisson, Daniel
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Reza, Salim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Fedorov, Igor
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Suopajärvi, Terhi
    University of Oulu, Oulu, Finland.
    Liimatainen, Henrikki
    University of Oulu, Oulu, Finland.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Determination of nanoparticle size using Rayleigh approximation and Mie theory2019In: Chemical Engineering Science, ISSN 0009-2509, E-ISSN 1873-4405, Vol. 201, no 29, p. 222-229Article in journal (Refereed)
    Abstract [en]

    Accurate determination of the size of nanoparticles has an important role in many different scientific and industrial purposes, such as in material, medical and environment sciences, colloidal chemistry and astrophysics. We describe an effective optical method to determine the size of nanoparticles by analysis of transmission and scattering of visible spectral range data from a designed UV-Vis multi-spectrophotometer. The size of the nanoparticles was calculated from the extinction cross section of the particles using Rayleigh approximation and Mie theory. We validated the method using polystyrene nanospheres, cellulose nanofibrils, and cellulose nanocrystals. A good agreement was achieved through graphical analysis between measured extinction cross section values and theoretical Rayleigh approximation and Mie theory predictions for the sizes of polystyrene nanospheres at wavelength range 450 - 750 nm. Provided that Rayleigh approximation's forward scattering (FS)/back scattering (BS) ratio was smaller than 1.3 and Mie theory's FS/BS ratio was smaller than 1.8. A good fit for the hydrodynamic diameter of nanocellulose was achieved using the Mie theory and Rayleigh approximation. However, due to the high aspect ratio of nanocellulose, the obtained results do not directly reflect the actual cross-sectional diameters of the nanocellulose. Overall, the method is a fast, relatively easy, and simple technique to determine the size of a particle by a spectrophotometer. Consequently, the method can be utilized for example in production and quality control purposes as well as for research and development applications.

  • 36.
    Niskanen, Ilpo
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. University of Oulu, Oulu, Finland.
    Suopajärvi, Terhi
    University of Oulu, Oulu, Finland.
    Liimatainen, Henrikki
    University of Oulu, Oulu, Finland.
    Fabritius, Tapio
    University of Oulu, Oulu, Finland.
    Heikkilä, Rauno
    University of Oulu, Oulu, Finland.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Determining the complex refractive index of cellulose nanocrystals by combination of Beer-Lambert and immersion matching methods2019In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 235, p. 1-6Article in journal (Refereed)
    Abstract [en]

    Nanocelluloses have received significant interest due to their unique structural, mechanical, and optical properties. Nanocellulose refractive indices can be used to indicate many crucial characteristics, such as crystallinity, transparency, and purity. Thus, accurate measurement is important. This study describes a new method to determine the wavelength dependent complex refractive index of cellulose nanocrystals (CNCs) by the measurement of light transmittance with a spectrophotometer. The data analysis is based on a combination of the Beer-Lambert and immersion liquid matching equations. The immersion liquid method's main advantage is that it is independent of particle shape and size. Moreover, the measurement is easy and relatively quick to perform. The present procedure is not restricted to the nanocellulose and could potentially be applied to other nanomaterials, such as hyphenate nanoparticle-based, lignin nanoparticles, nanopigments, biological entities, structural elements of dielectric metamaterials, and nanoparticle-based composites. 

  • 37.
    Olsen, Martin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Zhang, Renyun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Yang, Ya
    CAS Center for excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Frequency and voltage response of a wind-driven fluttering triboelectric nanogenerator2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, no 1, article id 5543Article in journal (Refereed)
    Abstract [en]

    Triboelectric nanogenerators (TENG:s) are used as efficient energy transducers in energy harvesting converting mechanical energy into electrical energy. Wind is an abundant source of mechanical energy but how should a good triboelectric wind harvester be designed? We have built and studied a TENG driven by air flow in a table-top sized wind tunnel. Our TENG constitutes of a plastic film of size10 cm × 2 cm which is fluttering between two copper electrodes generating enough power to light up a battery of LED:s. We measured the voltage and frequency of fluttering at different wind speeds from zero up to 8 m/s for three electrode distances 6 mm, 10 mm and 14 mm. We found that the frequency increases linearly with the wind speed with a cutoff at some low speed. Power was generated already at 1.6 m/s. We seem to be able to explain the observed frequency dependence on wind speed by assuming excitation of the film into different harmonics in response to von Kármán vortices. We also find that the voltage increase linearly with frequency. We anticipate that TENG:s of this design could be useful both as generators and speed sensors because they work at low air speeds.

  • 38.
    Olsson, Carl
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Att arbeta med ”Synchronization management”2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This essay revolves around Synchronization management & Synchronization licensing, or in short sync. The development of sync as a career choice and profession has been fast and is still ongoing. It is not until later years that sync has become a proper profession, whereas before it was just part of a publisher or sales person’s regular work.

    In short, sync deals with the commercial use of copyright protected music. A synchronization manager negotiates fees and licensing agreements while handling the dialogue between commercial businesses, publishers and in some cases song writers. Once a deal has been made a Synchronization license is granted by the owner of the copyrighted music, allowing the licensee (the person wanting to use the material) to use the music according to the agreement. A Synchronization license is most commonly used when a company wants to use music in either commercial, television or any kind of visual media.

    To get a better understand of Synchronization management a series of interviews were conducted to get three different perspectives. The first interview helped establish what a synchronization manager actually does, and was held with a person who works with the profession in question. To better grasp the song writing point of view when it comes to sync an interview with a person who was writing for sync briefs was conducted. Lastly, a publisher was interviewed to help understand synchronization licensing from a publishing point of view.

    The result generated by the interviews in combination with already written articles about Synchronization management helped get a better understanding of the profession and how different individuals are using it in their daily life in music. The main question of this essay was to establish if sync is a reliable source of income for “up-and-coming” song writers and music producers.

  • 39.
    Qin, C.
    et al.
    Chinese Academy of Sciences, Beijing, China.
    Yin, H.
    Chinese Academy of Sciences, Beijing, China.
    Wang, G.
    Chinese Academy of Sciences, Beijing, China.
    Zhang, Y.
    Chinese Academy of Sciences, Beijing, China.
    Liu, J.
    Chinese Academy of Sciences, Beijing, China.
    Zhang, Q.
    Chinese Academy of Sciences, Beijing, China.
    Zhu, H.
    Chinese Academy of Sciences, Beijing, China.
    Zhao, C.
    Chinese Academy of Sciences, Beijing, China.
    Radamson, Henry H.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Chinese Academy of Sciences, Beijing, China.
    A novel method for source/drain ion implantation for 20 nm FinFETs and beyond2019In: Journal of materials science. Materials in electronics, ISSN 0957-4522, E-ISSN 1573-482XArticle in journal (Refereed)
    Abstract [en]

    This paper presents a method to improve source/drain extension (SDE) ion implantation (I/I) process for sub-20 nm node FinFETs with no extra step in transistor process. Traditionally, SDE I/I process needs a large implant tilt angle and a high dose to obtain a heavy and conformal doping. However, this process leads to implantation shadow effects and Si-fin amorphization. These drawbacks can be removed in our new approach when SDE I/I is modified and moved after S/D epitaxy process (SDE I/I-last). Because of the facet planes of the SiGe layer, the ions are allowed to be implanted with small tilt. This is helpful to avoid shadow effects of implantation and to keep the low defect density in the S/D. As a result, the external resistance (R EXTRNL ) is not high and the strain relaxation is minor in S/D epitaxy layer. Finally, p-type FinFETs with 25 nm gate length with SDE I/I-last are fabricated. These new FinFETs demonstrate ~ 50% on-state current (I ON ) improvement compared to those transistors fabricated by traditional method.

  • 40.
    Radamson, Henry H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    He, Xiaobin
    Chinese Acad Sci, Beijing, Peoples R China.
    Zhang, Qingzhu
    Chinese Acad Sci, Beijing, Peoples R China; Gen Res Inst Nonferrous Met, Beijing, Peoples R China.
    Liu, Jonbiao
    Chinese Acad Sci, Beijing, Peoples R China.
    Cui, Hushan
    Beihang Univ, BDBC, Beijing, Peoples R China.
    Xiang, Jinjuan
    Chinese Acad Sci, Beijing, Peoples R China.
    Kong, Zhenzhen
    Chinese Acad Sci, Beijing, Peoples R China.
    Xiong, Wenjuan
    Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    Li, Junjie
    Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    Gao, Jianfeng
    Chinese Acad Sci, Beijing, Peoples R China.
    Yang, Hong
    Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    Gu, Shihai
    Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    Zhao, Xuewei
    Chinese Acad Sci, Beijing, Peoples R China; Univ Sci & Technol China, Hefei, Anhui, Peoples R China.
    Du, Yong
    Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    Yu, Jiahan
    Chinese Acad Sci, Beijing, Peoples R China.
    Wang, Guilei
    Chinese Acad Sci, Beijing, Peoples R China; Univ Chinese Acad Sci, Beijing, Peoples R China.
    Miniaturization of CMOS2019In: Micromachines, ISSN 2072-666X, E-ISSN 2072-666X, Vol. 10, no 5, article id 293Article in journal (Refereed)
    Abstract [en]

    When the international technology roadmap of semiconductors (ITRS) started almost five decades ago, the metal oxide effect transistor (MOSFET) as units in integrated circuits (IC) continuously miniaturized. The transistor structure has radically changed from its original planar 2D architecture to today's 3D Fin field-effect transistors (FinFETs) along with new designs for gate and source/drain regions and applying strain engineering. This article presents how the MOSFET structure and process have been changed (or modified) to follow the More Moore strategy. A focus has been on methodologies, challenges, and difficulties when ITRS approaches the end. The discussions extend to new channel materials beyond the Moore era.

  • 41.
    Rahman, Hafizur
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    An, Siwen
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Norlin, Börje
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Fröjdh, Christer
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Persson, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Maximized wood chip impregnation efficiency validated by new miniaturized X-ray fluorescence techniques2019Conference paper (Refereed)
    Abstract [en]

    Manufacturing of chemi-thermomechanical pulp (CTMP) is increasing due to increased demand for packaging materials such as cardboard as well as tissue and other hygiene products. Today high yield pulp (HYP) is produced from different wood species. It is well-known that chip-refining is normally responsible for more than 60% of the electric energy consumption in most high yield pulping process. There are opportunities to improve energy efficiency and quality stability in defibration processes by means of optimizing impregnation. Impregnation is a key unit operation in CTMP production as well as in all chemical pulping and biorefinery systems. The efficiency of the impregnation is known to be crucial (Ferritsius et al. 1985; Gorski et al. 2010). Early research showed difficulties to achieve even distribution of sulphite and sodium ions in wood chips resulting in inhomogeneous fibre properties (Bengtsson et al. 1988). Increased and homogenous sulphonation leads to reduced shive content, which is a key factor in all end product applications. To address this issue developing a new type miniaturized X-ray based technique (XRF) to measure local concentration of sulphur and sodium across wood chips and in individual fibres could become a key tool.

     

    The presence of elements as sulphur and sodium can be detected by X-ray fluorescence (XRF) or spectral absorption. At the XRF, images the surface of the sample using specific energies from K-shell or L-shell fluorescence. This method is investigated at the X-ray laboratory in Mid Sweden University research centre STC (Sensitive Things that Communicate) (Norlin et al. 2018). At the spectral absorption, images specific K-shell absorption energies in transmission X-ray images of the sample, a method widely used in medical diagnosis. This transmission method might also be further investigated for this application in the future (Frojdh et al. 2013; Reza et al. 2013). Both methods can be validated by using monoenergetic radiation from synchrotron facilities.

     

    An XRF imaging system uses a collimated X-ray source and a spectroscopic detector. The sample is scanned to make an image of the content of the substances of interest. A specific challenge in this case is that the low energy fluorescence photons from sulphur (S) and sodium (Na) are easily absorbed in air, which makes imaging in a different atmosphere necessary.

     

    The measurement setup has been simulated using MCNP (C. J. Werner, 2017) to validate the system setup and to select the correct, geometry, shielding, filtering and atmosphere for the measurement. The solution was to use a titanium box flooded with helium to minimise the absorption of fluorescence photons and to shield from scattered photons that might disturb the measurement, fig 1. A filter has been added to the X-ray source to make it nearly monoenergetic and to avoid emission of photons with energies close to the expected fluorescence. The system has been used to estimate sodium and sulphur content in low grammage handsheet (CTMP) or single wood chip samples. It is possible to build a laboratory instrument similar to the prototype setup to obtain the distribution of sodium and sulphur in XRF imaging.

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    Figure 1: Photograph of XRF measurement setup with of moveable Helium atmosphere Ti box

    However, the technique we are developing can become useful in mills to improve and control process efficiency, product properties and to find solutions to process problems in future. In addition, a more even distribution of the sulphonation can reduce specific energy demand in chip refining at certain shive content.

     

    References

     

    1.      Bengtsson, G., Simonson, R., Heitner, C., Beatson, R., and Ferguson, C. (1988): Chemimechanical pulping of birch wood chips, Part 2: Studies on impregnation of wood blocks using scanning electron microscopy and energy dispersive x-ray analysis, Nord. Pulp Paper Res. J. 3 (3), 132-138.

    2.      C. J. Werner, (2017): MCNP User's manual, Code Version 6.2, Los Alamos National Laboratory report, LA-UR-17-29981.

    3.      Ferritsius, O., and Moldenius, S. (1985): The effect of impregnation method on CTMP properties. In International Mechanical Pulping Conference Proceedings, SPCI, Stockholm (p. 91).

    4.      Frojdh, C., Norlin, B. and Frojdh, E. (2013): Spectral X-ray imaging with single photon processing detectors, Journal of Instrumentaion, Volume 8, Article number C02010.  

    5.      Gorski, D., Hill, J., Engstrand, P., and Johansson, L. (2010): Reduction of energy consumption in TMP refining through mechanical pre-treatment of wood chips, Nord. Pulp Paper Res. J, 25(2), 156-161.

    6.      Norlin, B., Reza, S., Fröjdh, C. and Nordin, T. (2018): Precision scan-imaging for paperboard quality inspection utilizing X-ray fluorescence, Journal of Instrumentation, Volume: 13, Article number C01021.

    7.      Reza, S., Norlin, B. and Thim, J. (2013): Non-destructive method to resolve the core and the coating on paperboard by spectroscopic x-ray imaging, Nord. Pulp Paper Res. J. 28 (3), 439-442.

     

  • 42.
    Rexhaj, Kastriot
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Machine visual feedback through CNN detectors: Mobile object detection for industrial application2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper concerns itself with object detection as a possible solution to Valmet’s quest for a visual-feedback system that can help operators and other personnel to more easily interact with their machines and equipment. New advancements in deep learning, specifically CNN models, have been exploring neural networks with detection-capabilities. Object detection has historically been mostly inaccessible to the industry due the complex solutions involving various tricky image processing algorithms. In that regard, deep learning offers a more easily accessible way to create scalable object detection solutions. This study has therefore chosen to review recent literature detailing detection models with a selective focus on factors making them realizable on ARM hardware and in turn mobile devices like phones. An attempt was made to single out the most lightweight and hardware efficient model and implement it as a prototype in order to help Valmet in their decision process around future object detection products. The survey led to the choice of a SSD-MobileNetsV2 detection architecture due to promising characteristics making it suitable for performance-constrained smartphones. This CNN model was implemented on Valmet’s phone of choice, Samsung Galaxy S8, and it successfully achieved object detection functionality. Evaluation shows a mean average precision of 60 % in detecting objects and a 4.7 FPS performance on the chosen phone model. TensorFlow was used for developing, training and evaluating the model. The report concludes with recommending Valmet to pursue solutions built on-top of these kinds of models and further wishes to express an optimistic outlook on this type of technology for the future. Realizing performance of this magnitude on a mid-tier phone using deep learning (which historically is very computationally intensive) sets us up for great strides with this type of technology in the future; and along with better smartphones, great benefits are expected to both industry and consumers.

  • 43.
    Reza, Salim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Stressed in a small group or university? Think Big!2019Other (Other (popular science, discussion, etc.))
  • 44.
    Rofors, E.
    et al.
    Lund Univ, Lund.
    Perrey, H.
    Lund Univ, Lund; European Spallat Source ERIC, Lund.
    Al Jebali, R.
    European Spallat Source ERIC, Lund; Univ Glasgow, Glasgow, Lanark, Scotland.
    Armand, J. R. M.
    Univ Glasgow, Glasgow, Lanark, Scotland.
    Boyd, L.
    Univ Glasgow, Glasgow, Lanark, Scotland.
    Clemens, U.
    Forschungszentrum Julich, Julich, Germany.
    Desert, S.
    Univ Paris Saclay, Gif Sur Yvette, France.
    Engels, R.
    Forschungszentrum Julich, Julich, Germany.
    Fissum, K. G.
    Lund Univ, Lund; European Spallat Source ERIC, Lund.
    Frielinghaus, H.
    Forschungszentrum Julich, Julich, Germany.
    Gheorghe, C.
    Integrated Detector Elect AS, Oslo, Norway.
    Hall-Wilton, Richard
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. European Spallat Source ERIC, Lund.
    Jaksch, S.
    Forschungszentrum Julich, Julich, Germany.
    Jalgen, A.
    Lund Univ, Lund.
    Kanaki, K.
    European Spallat Source ERIC, Lund.
    Kemmerling, G.
    Forschungszentrum Julich, Julich, Germany.
    Maulerova, V
    Lund Univ, Div Nucl Phys, Lund.
    Mauritzson, N.
    Lund Univ, Lund.
    Montgomery, R.
    Univ Glasgow, Glasgow, Lanark, Scotland.
    Scherzinger, J.
    Lund Univ, Lund; European Spallat Source ERIC, Lund; Univ Pisa, Pisa, Italy; INFN, Pisa, Italy.
    Seitz, B.
    Univ Glasgow, Glasgow, Lanark, Scotland.
    Response of a Li-glass/multi-anode photomultiplier detector to alpha-particles from Am-2412019In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 929, p. 90-96Article in journal (Refereed)
    Abstract [en]

    The response of a position-sensitive Li-glass scintillator detector to alpha-particles from a collimated Am-241 source scanned across the face of the detector has been measured. Scintillation light was read out by an 8 x 8 pixel multi-anode photomultiplier and the signal amplitude for each pixel has been recorded for every position on a scan. The pixel signal is strongly dependent on position and in general several pixels will register a signal (a hit) above a given threshold. The effect of this threshold on hit multiplicity is studied, with a view to optimize the single-hit efficiency of the detector.

  • 45.
    Rusu, C.
    et al.
    RISE, Sensor Systems department, Acreo.
    Bader, Sebastian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Oelmann, Bengt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Alvandpour, A.
    Linköping University.
    Enoksson, P.
    Chalmers Univ. of Technology, Gothenburg.
    Braun, T.
    Fraunhofer-IZM, Berlin, Germany.
    Tiedke, S.
    aixACCT Systems GmbH, Aachen, Germany.
    Molin, R. Dal
    Cairdac, Clamart, France.
    Férin, G.
    Vermon SA, Tours, France.
    Torvinen, P.
    Spinverse Innovation Management Oy, Espoo, Finland.
    Liljeholm, J.
    Silex Microsystems AB, Järfälla.
    Challenges for Miniaturised Energy Harvesting Sensor Systems2018In: 2018 10th International Conference on Advanced Infocomm Technology (ICAIT), 2018, p. 214-217Conference paper (Refereed)
  • 46.
    Rydblom, Staffan
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Thörnberg, Benny
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olsson, Esbjörn
    Swedish Meteorol & Hydrol Inst (SMHI), Sundsvall.
    Field Study of LWC and MVD Using the Droplet Imaging Instrument2019In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 68, no 2, p. 614-622Article in journal (Refereed)
    Abstract [en]

    The droplet imaging instrument (DII) is a new instrument for cost-effective in situ measurements of the size and concentration of water droplets. The droplet size distribution and the concentration of atmospheric liquid water are important for the prediction of icing on structures, such as wind turbines. To improve the predictions of icing, there is a need to explore cost-effective working solutions. Through imaging, a wide range of droplet sizes can be measured. This paper describes a study of the atmospheric liquid water content and the median volume diameter using the DII and a commercial reference instrument--the cloud droplet probe 2 from Droplet Measurement Technologies Inc. The measurement is done at a weather measurement station in mid-Sweden. For a second validation, the result is compared with predictions using a numerical weather prediction model. The size measurement of the DII is verified using polymer microspheres of four known size distributions. The study shows that the DII measurement is precise, but there is a systematic difference between the two compared instruments. It also shows that droplets larger than 50 μm in diameter are occasionally measured, which we believe is important for the prediction of icing.

  • 47.
    Saeedian, Meysam
    et al.
    Aalto University, Espoo, Finland.
    Pouresmaeil, Edris
    Aalto University, Espoo, Finland.
    Samadaei, Emad
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Godinho Rodrigues, Eduardo Manuel
    Management and Production Technologies of Northern Aveiro—ESAN, Oliveira de Azeméis, Portugal.
    Godina, Radu
    New University of Lisbon, Caparica, Portugal.
    Marzband, Mousa
    Northumbria University, Newcastle upon Tyne, UK.
    An innovative dual-boost nine-level inverter with low-voltage rating switches2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 2, article id 207Article in journal (Refereed)
    Abstract [en]

    This article presents an innovative switched-capacitor based nine-level inverter employing single DC input for renewable and sustainable energy applications. The proposed configuration generates a step-up bipolar output voltage without end-side H-bridge, and the employed capacitors are charged in a self-balancing form. Applying low-voltage rated switches is another merit of the proposed inverter, which leads to extensive reduction in total standing voltage. Thereby, switching losses as well as inverter cost are reduced proportionally. Furthermore, the comparative analysis against other state-of-the-art inverters depicts that the number of required power electronic devices and implementation cost is reduced in the proposed structure. The working principle of the proposed circuit along with its efficiency calculations and thermal modeling are elaborated in detail. In the end, simulations and experimental tests are conducted to validate the flawless performance of the proposed nine-level topology in power systems.

  • 48.
    Samadaei, Emad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Kaviani, Mohammad
    Mazandaran University of Science and Technology University.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    A 13-levels Module (K-Type) with two DC sources for Multilevel Inverters2019In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 66, no 7, p. 5186-5196Article in journal (Refereed)
    Abstract [en]

    This paper presents a new reconfiguration module for asymmetrical multilevel inverters in which the capacitors are used as the DC links to creates the levels for staircase waveforms. This configuration of multilevel converter makes a reduction in DC sources. On the other hand, it is possible to generate 13 levels with lower DC sources. The proposed module of multilevel inverter generates 13 levels with two unequal DC sources (2VDC and 1VDC). It also involves two chargeable capacitors and 14 semiconductor switches. The capacitors are self-charging without any extra circuit. The lower number of components makes it desirable to use in wide range of applications. The module is schematized as two back-to-back T-type inverters and some other switches around it. Also, it can be connected as cascade modular which lead to a modular topology with more voltage levels at higher voltages. The proposed module makes the inherent creation of the negative voltage levels without any additional circuit (such as H-bridge circuit). Nearest level control switching modulation (NLC) scheme is applied to achieve high quality sinusoidal output voltage. Simulations are executed in MATLAB/Simulink and a prototype is implemented in the power electronics laboratory which the simulation and experimental results show a good performance.

  • 49.
    Sandberg, Sebastian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Musikens inverkan på lyssnaren.: En litteraturstudie kompletterad med en implementering av strukturerad lyssnande.2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Introduktion: Ohälsa har de senaste åren ökat bland befolkningen nationellt. Det finns ett större

    behov för alternativa behandlingar för att kunna ge lindring. En av dessa alternativa metoder är

    implementering av musik. Det talas om ’’musikmedicin’’ - ett sätt att främja, förstärka och berika

    patienters status.

    Bakgrund: Det finns omfattande studier om musikens påverkan på människan. Studier på

    fysiologisk och psykologisk respons vid musiklyssnande har fått ett större intresse de senaste tjugo

    åren. Tidigare så har musikerns roll varit frikopplad från studierna då dessa mestadels

    implementerat inspelade medier.

    Syfte: Att identifiera hur musiken påverkar lyssnaren.

    Metod: Litteratursökning har innefattat litteratur på ämnet musik och hälsa, avhandlingar på nätet

    och även strömmande videos. En enkätmetod med implementerande lyssningsmoment har

    upprättats med en testgrupp. Testgruppen bestod av nio deltagare, 5 kvinnor och fyra män, som fått

    lyssna på ett eget utvalt verk 2 gånger om dagen i 3 veckors tid.

    Resultat: Musik fungerar som ett medie som kan påverka kroppen och sinnet i ett hälsofrämjande

    syfte. Resultat talar för att musiklyssnande kan främja individens hälsa genom fysiologiska

    reaktioner, som exempelvis dopaminfrisättning. Det faktorer som spelar in för att få önskvärda

    resultat är bland andra musiksmak, social - och kulturell koppling och emotionell koppling till

    musiken. Det finns mallar som går att förhålla sig till för att förstå sambandet mellan musik, hälsa

    och individen för implementering. Resultaten från enkätmetoden talar för att majoriteten av

    deltagarna har upplevt förbättrade resultat med sänkta stressnivåer än innan utfört moment.

    Diskussion: Diskussionen jämför resultatet i enkätstudien med tidigare försök från litteraturstudien.

    Metodens för och nackdelar diskuteras. Musikerns och kompositörens roll i ämnet diskuteras och

    framställs med alternativa positioner för framtida bruk. Detta för att skapa förståelse hos musikern/

    kompositören mot resultaten i denna studie och även. Metoddiskussionen fördjupar sig i för och

    nackdelar med studiens metoder.

  • 50.
    Skyllerstedt, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Övertoner i motordrivsystem: Metod för att beräkna förluster2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Utvecklingen av kraftelektronik har möjliggjort tämjandet av vår tids arbetshäst, asynkronmotorn.

    Att driva motorn med en frekvensomriktare gör motorn mer effektiv, och den mjukare driften minskar på slitaget. Två faktorer som spar både pengar och miljö, och är av betydelse för att bygga ett hållbart samhälle.

    Baksidan är att frekvensomriktaren orsakar elektro­magnetiska stör­ningar i sin elektriska omgivning, vilket blir en konsekvens av att installera en frekvensomriktare. I den här rapporten behandlas främst de övertoner som orsakas av frekvensomriktarens likriktarsteg, och som beror på att den drar distorderad ström från spänningskällan. Strömövertoner och spänningsövertoner utvecklar en distorderad effekt, som inte tillför något aktivt arbete i belastningen, och kan därför betrak­tas som en förlust i exempelvis ledningar och transfor­matorer, när den flyttas fram och åter mellan spän­ningskälla och belastning.

    Frekvensomriktarens effektfaktor ger en indikation på mängden distorderad effekt, och kan användas i ett beräkningsprogram för att beräkna förluster som beror på frekvensomriktarens övertoner.

    För att minska den distorderade effekten behöver frekvensomriktarens effektfaktor förbättras, vilket kan ske genom reducering av övertonerna. Att använda ett 12-puls­system är en metod att göra detta på, men det finns även andra metoder för att reducera övertonerna. Valet av metod är anläggningsspecifik och det går inte att generellt säga när det lönar sig att välja ett 12-pulssystem.  

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