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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 Polyurethane2019In: FLEPS 2019 - IEEE International Conference on Flexible and Printable Sensors and Systems, Proceedings, 2019, article id 8792266Conference paper (Refereed)
  • 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 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.

  • 5.
    Akram, Shazad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Alam, Farhan Muhammad
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    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.
    Capacitive and optical sensing for automatic detection and characterization of cleaning sponges in fiber optic microduct installations2019In: Proceedings - 2019 8th International Workshop on Advances in Sensors and Interfaces, IWASI 2019, IEEE, 2019, p. 274-278, article id 8791315Conference paper (Refereed)
    Abstract [en]

    Optical fiber duct installation requires blowing of cleaning sponges for dirt and moisture removal before blowing the fiber cables. The traditional method requires one operator that blows the sponge and one operator in the receiving end that manually evaluate the sponges until a dry sponge is received. The proposed system eliminates the need of a second operator by introducing a solution for automatic sponge detection and characterization of moisture in sponges at the receiving end. An optical sensor is used for detection and a capacitive sensor is developed to measure the sponge's wetness. Sensor data is automatically transmitted back to the operator at the feeding end via a mobile phone. The system is characterized to work with sponges ranging from saturated with wetness to what is deemed as dry. 

  • 6.
    Akram, Shazad
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    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.
    LTspice electro-thermal model of joule heating in high density polyethylene optical fiber microducts2019In: Electronics (Switzerland), ISSN 2079-9292, Vol. 8, no 12, article id 1453Article in journal (Refereed)
    Abstract [en]

    At present, optical fiber microducts are joined together by mechanical type joints. Mechanical joints are bulky, require more space in multiple duct installations, and have poor water sealing capability. Optical fiber microducts are made of high-density polyethylene which is considered best for welding by remelting. Mechanical joints can be replaced with welded joints if the outer surface layer of the optical fiber microduct is remelted within one second and without thermal damage to the inner surface of the optical fiber duct. To fulfill these requirements, an electro-thermal model of Joule heat generation using a copper coil and heat propagation inside different layers of optical fiber microducts was developed and validated. The electro-thermal model is based on electro-thermal analogy that uses the electrical equivalent to thermal parameters. Depending upon the geometric shape and material properties of the high-density polyethylene, low-density polyethylene, and copper coil, the thermal resistance and thermal capacitance values were calculated and connected to the Cauer RC-ladder configuration. The power input to Joule heating coil and thermal convection resistance to surrounding air were also calculated and modelled. The calculated thermal model was then simulated in LTspice, and real measurements with 50 µm K-type thermocouples were conducted to check the validity of the model. Due to the non-linear transient thermal behavior of polyethylene and variations in the convection resistance values, the calculated thermal model was then optimized for best curve fitting. Optimizations were conducted for convection resistance and the power input model only. The calculated thermal parameters of the polyethylene layers were kept intact to preserve the thermal model to physical structure relationship. Simulation of the optimized electro-thermal model and actual measurements showed to be in good agreement. 

  • 7.
    Ali M., Ahmed
    et al.
    University of Duisburg-Essen.
    Moulik, Bedatri
    Amity University.
    Beganovic, Nejra
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Söffker, Dirk
    University of Duisburg-Essen.
    A State-of-Health-Oriented Power Management Strategy for Multi-Source Electric Vehicles Considering Situation-Based Optimized Solutions in Real-Time2019In: Proceedings of the Annual Conference of the PHM Society 11 (1), Scottsdale, Arizona, USA: PHM Society , 2019, Vol. 11, p. 1-10, article id 783Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel situation-based power and battery health management strategy for fuel cell vehicles. In such hybrid powertrains, the synergy role of batteries is essential to minimize overall power consumption and maintain higher electrical efficiency of the fuel cell. On the other hand, lifetime degradation of the battery is associated with the recurrent charging / discharging cycles. The proposed power management strategy addresses the trade-off between these contradictory objectives. Vehicle states in each situation are defined in terms of driver-related identification parameters (power demand and speed) corporately with powertrain related ones (on-board battery's state of charge). Optimal power handling solution for each situation is searched offline considering different optimization criteria: range extension, lifetime maximization, or power consumption minimization. A weighted fusion of these optimized solutions can be implemented online based on desired driving strategy, leading to situation-based optimized solution. This contribution aims to provide flexible power handling options meeting performance requirements (energy efficiency and driveability) without scarifying battery life. Simulation tests using different driving cycles are conducted for evaluation purpose.

  • 8.
    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.

  • 9.
    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.

  • 10.
    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. 

  • 11.
    Alqaysi, Hiba
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Lawal, Najeem
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Fedorov, Igor
    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.
    O'Nils, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Design Exploration of Multi-Camera Dome2019In: ICDSC 2019 Proceedings of the 13th International Conference on Distributed Smart Cameras, New York, NY: ACM Digital Library, 2019, article id Article No. 7aConference paper (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.

  • 12.
    An, Siwen
    et al.
    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.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Thungström, Göran
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Comparison of Elemental Analysis Techniques for Fly Ash from Municipal Solid Waste Incineration using X-rays and Electron Beams2019In: IOP Conference Series: Earth and Environmental Science, Institute of Physics (IOP), 2019, Vol. 337, no 1, article id 012007Conference paper (Refereed)
    Abstract [en]

    With the rapid expansion of the waste incineration business both in Europe and globally, there is a growing need for the elemental analysis for fly ash from municipal solid waste incineration. In this work, samples of washed and unwashed ash from municipal solid waste incineration in Sundsvall are evaluated. Qualitative analysis and semi-quantitative analysis are used to compare two elemental analysis methods, scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) measurement. Both methods are used to retrieve the difference in elemental composition between washed and unwashed fly ash. SEM-EDS accurately detects light elements from well-prepared samples in a vacuum environment, while, for online measurements, XRF is a potential method that analyses hazardous metal content in the fly ash. 

  • 13.
    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. 

  • 14.
    Andresen, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Skillnader i upphandling mellan EBR och AMA2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today's Swedish power grid has a major need for renovation and upgrading, which gives a big investment requirement over the next few years. This makes it important to find new entrepreneurs in addition to those already available today. Find a way to become more attractive and interesting for these entrepreneurs. This report highlights two methods that outsourcer have to relate to. First method is Electrical Building Rationalization (EBR) and the other method is general material and work description (AMA). The system of EBR is a secure system based on long-term statistics from installations, renovations and maintenance. There the advantages of standardized components are that they are cost-effective and create a quality of work performed. AMA is a reference tool for building projects from scratch. It's freer in its structure when planning a facility. One does not need relate to more strict approach. This report looks at the differences in EBR / AMA and looks at what are good changes to attract new actors in the market. What can be changed in the future and at the same time affecting projecting design and procurement documentation.

  • 15.
    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.

  • 16.
    Ashraf, Shakeel
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Forsberg, Viviane
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. KTH, Wallenberg Wood Science Center, Stockholm.
    Mattsson, Claes G.
    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.
    Thermoelectric properties of n-type molybdenum disulfide (MoS2) thin film by using a simple measurement method2019In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 21, article id 3521Article in journal (Refereed)
    Abstract [en]

    In this paper, a micrometre thin film of molybdenum disulfide (MoS2) is characterized for thermoelectric properties. The sample was prepared through mechanical exfoliation of a molybdenite crystal. The Seebeck coefficient measurement was performed by generating a temperature gradient across the sample and recording the induced electrical voltage, and for this purpose a simple measurement setup was developed. In the measurement, platinum was utilized as reference material in the electrodes. The Seebeck value of MoS2 was estimated to be approximately -600 μV/K at a temperature difference of 40 °C. The negative sign indicates that the polarity of the material is n-type. For measurement of the thermal conductivity, the sample was sandwiched between the heat source and the heat sink, and a steady-state power of 1.42Wwas provided while monitoring the temperature difference across the sample. Based on Fourier's law of conduction, the thermal conductivity of the sample was estimated to be approximately 0.26 Wm-1 K-. The electrical resistivity was estimated to be 29 W cm. The figure of merit of MoS2 was estimated to be 1.99 × 10-4. 

  • 17.
    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

  • 18.
    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.

  • 19.
    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. 

  • 20.
    Bakar, Muhammad Abu
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Alam, Farhan Muhammad
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Modeling and Characterization of Series Connected Hybrid Transformers for Low-Profile Power Converters2020In: IEEE Access, E-ISSN 2169-3536, Vol. 8, p. 1-14Article in journal (Refereed)
    Abstract [en]

    Compact and low profile power converters are the main business of today's power industry. A significant volume of a power converter is occupied by the power transformer. This article proposes a unique solution that would make the power converters low profile. Instead of designing a power converter by using a single bulky transformer, the solution proposed is to split the main bulky transformer into a number of low profile transformers. This not only reduces the total weight and volume of the converter but also the total transformer losses. The use of more than one transformer in series reduces the applied voltage on the transformers, which minimizes the required turns ratio and decreases the stress on the secondary rectifiers and filter elements. Moreover, the decrease in the applied voltage reduces the proportional loss per transformer and makes it possible to design a hybrid transformer by combining Litz wire and traces of a printed circuit board. The reduced copper loss and lower heat dissipation per transformer simplify thermal management. An analytical comparison is made between the utilization of a single transformer or a number of transformers. The procedure of splitting a volume of a single transformer into a number of small transformers has been comprehensively discussed. The idea is investigated both experimentally and in computer simulation for an example application of a phase shifted full bridge dc-dc converter. The converter is characterized up to a load power of 2.2 kW at Vin = 400 Vdc and Vout = 48 Vdc. To make the approach more practical, the transformers are modeled using the traditional analytical method. The design of the example application using the split transformer approach reduces the total transformer weight by 45%, compared to the traditional approachwith a single transformer. The converter also shows good performance with a maximum efficiency of 96%.

  • 21.
    Bakar, Muhammad Abu
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Alam, Farhan Muhammad
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Das, Moumita
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Barg, Sobhi
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Reconfigurable three state dc-dc power converter for the wide output range applications2019In: IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, Lisbon: IEEE, 2019, p. 4911-4916Conference paper (Refereed)
    Abstract [en]

    Improving the dc voltage gain of power converters has been the primary focus of the current and past research in the area of power electronics. This work presents another solution to widen the range of the output voltage. It proposes three reconfigurable steps for the output voltage. The range of theoutput voltage varies up to four times the base level. These configurations together vary the output voltage from 15 to 96 volts. A soft switched dc-dc power converter is built with the traditional topology of phase shifted full bridge converter along with improved characteristics. For better management of thetransformer loss, a configuration of four transformers has been employed. The proportional gate drive approach is implemented to obtain four similar isolated blocks of the output voltage. This makes it possible to either configure these blocks all in series,parallel or in series/ parallel combination of two. The concept is verified in a low-profile prototype. The hardware is characterized up to the load power of 1kW for the input voltage of 400Vdc. The converter reports better efficiency over the complete range of output voltage.

  • 22.
    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.

  • 23.
    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.

  • 24.
    Barg, Sobhi
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Mid Sweden University.
    Alam, Farhan Muhammad
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Modeling of the Geometry Effect on the Core Loss and Verification with a Measurement Technique Based on the Seebeck Effect and FEA2019In: IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society / [ed] IEEE, IEEE, 2019, p. 1832-1837Conference paper (Refereed)
    Abstract [en]

    In this paper, the effect of the core geometry of non-toroidal magnetic cores on the magnetic loss is investigated. A frequency dependent core material-geometry loss factor is developed. This factor is function of the change in the non-toroidal core section and the Steinmetz parameter “β”. In addition, the temperature effect is included in the developed loss model for wide range of frequency and magnetic flux density. The model is applied for ER core and 3C92 ferrite material. The core loss measurements are performed using a Peltier cell. The principle of operation of the Peltier cell is based on the Seebeck effect, which convert the heat flow due to the temperature difference into electric power.  The calibration of the Peltier cell is validated with a resistive load and a relative error lower than 1% is achieved. The accuracy of the developed model is assessed with FEA and the experimental results. A maximum error of 10% is registered of the developed core loss model.

  • 25.
    Barg, Sobhi
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Multi‑objective Pareto and GAs nonlinear optimization approach for fyback transformer2019In: Electrical engineering (Berlin. Print), ISSN 0948-7921, E-ISSN 1432-0487, Vol. 101, no 3, p. 995-1006Article in journal (Refereed)
    Abstract [en]

    Design and optimization of high-frequency inductive components is a complex task because of the huge number of variables to manipulate, the strong interdependence and the interaction between variables, the nonlinear variation of some design variables as well as the problem nonlinearity. This paper proposes a multi-objective design methodology of a 200-W flyback transformer in continuous conduction mode using genetic algorithms and Pareto optimality concept. The objective is to minimize loss, volume and cost of the transformer. Design variables such as the duty cycle, the winding configuration and the core shape, which have great effects on the former objectives but were neglected in previous works, are considered in this paper. The optimization is performed in discrete research space at different switching frequencies. In total, 24 magnetic materials, 6 core shapes and 2 winding configurations are considered in the database. Accurate volume and cost models are also developed to deal with the optimization in the discrete research space. The bi-objective (loss–volume) and tri-objective (loss–volume–cost) optimization results are presented, and the variations of the design variables are analyzed for the case of 60 kHz. An example of a design (30 kHz) is experimentally verified. The registered efficiency is 88% at full load.

  • 26.
    Beganovic, Nejra
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Moulik, Bedatri
    Amity University.
    Ali M., Ahmed
    University of Duisburg-Essen.
    Söffker, Dirk
    University of Duisburg-Essen.
    Lifetime Model Development for Integration in Power Management of HEVs By Terms of Minimizing Fuel Consumption and Battery Degradation2019In: Proceedings of the Annual Conference of the PHM Society 2019, PHM Society , 2019, Vol. 11, p. 1-8, article id 784Conference paper (Refereed)
    Abstract [en]

    Along with increasingly frequent use of electric and hybrid electric vehicles, the constraints and demands placed on them become stricter. The most noticeable challenge considering Hybrid Electric Vehicles (HEVs) is to provide an optimal power flow between multiple electric sources alongside provided as less as possible aging of energy storage components. To provide efficient battery usage with respect to battery life, it becomes unavoidable to develop battery lifetime models, which not only reflect the State-of-Heath (SoH) but also allow battery lifetime prediction. The lifetime-oriented battery models have to be integrated into power management. To be used efficiently and to provide optimal power split ensuring mitigation of battery degradation without sacrificing desired power consumption, accurate modeling of battery degradation is of utmost importance. This implies that gradual battery degradation, which is directly affected by applied loading profiles, has to be monitored and used as additional control input. Moreover, the lifetime model developed in this case has to provide model outputs also in the timeframe of power management. In this contribution, a machine state-based lifetime model for electric battery source was developed. In this particular case, different degradation states as well as machine state transitions are identified in accordance with current operating conditions. Here, the change in charge / discharge rate (C-rate), overcharging / undercharging of the battery (depth-of-discharge), and the temperature are taken into consideration to define machine model states. The End-of-Lifetime (EoL) is defined as the deviation between nominal and current ampere-hour (Ah) throughput. The proposed machine state-based lifetime model is verified based on existing battery lifetime models using simulation setup. The developed lifetime model in this way serves as a prerequisite for its integration into power management with an aim to provide the trade-off between aforementioned conflicting objectives; fuel consumption and battery degradation.

  • 27.
    Björklund, Johannes
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    PLC-simulering: Virtuell balningslinje i felsökningssyfte2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Valmet do not have a method for testing the functionality of the control systems for the conveyors they deliver with their baling lines, as a result a lot of time is spent troubleshooting on site. They therefore seek a method which allows them to simulate these control systems to find and fix any faults in the code before delivery. Printed literature and articles published in scientific journals have been the foundation to the conducted study presented in this report. A code for a control system was provided and studied to gain understanding of its functionality. To simulate, a model which represents and behaves like the system to be simulated is required. If the simulation is to useful the model must be a sufficiently accurate representation of reality. A simulation has many advantages, it can prevent delays, save money, improve working conditions and safety. A concept for simulating this control system was developed during this thesis work. The concept overwrites the values of the physical sensors before the control logic. Every conveyor is simulated individually. The simulation has a function which saves the position of the virtual bale along the conveyor. The simulation is visualized in an HMI where the movement of the bales can be followed. The concept showed to worked very well to simulate the provided code. A large amount of the simulation should be possible to reuse when simulating other types of conveyors. Whether the concept will be able to detect faults in the code are though not confirmed, but most likely. The conclusion that can be drawn from the developed concept is that it has potential to simulate this type of control system if it is developed further, in which case the commissioning will be reduced.

  • 28.
    Carratu, Marco
    et al.
    University of Salerno, Italy.
    Liguori, Consolatina
    University of Salerno, Italy.
    Pietrosanto, Antonio
    University of Salerno, Italy; SPRING OFF srl, Italy.
    O'Nils, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Lundgren, Jan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Data Fusion for Timber Bundle Volume Measurement2019Conference paper (Refereed)
  • 29.
    Chen, Jialei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Active Infrared light power supply for indoor wireless sensor nodes2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In order to expand the energy source in energy harvesting, this thesis explores the feasibility of using infrared light source as the energy source. Firstly, the thesis investigated the current energy harvesting solution and the way of using infrared light energy, and determined the use of crystalline solar panels as energy harvesters. By testing the illu-mination characteristics of the infrared light source, a wireless sensor node based on active infrared light energy is designed to verify the reliability of the energy harvesting system. The node uses the BQ25505 as a power management circuit to store energy in the supercapacitor and power the system load through the boost convertor of the TPS61020. The load is a CMWX1ZZABZ wireless module based on LoRa network communication. The thesis measures the energy conversion efficiency of each part of the system. Through data analysis and evaluation, it is considered feasible to use the infrared light source as the energy source of the wireless sensor node.

  • 30.
    Chen, Zhiqiang
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Evaluating the performance of a vibration energy harvester under complex excitation2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years, vibration energy harvesting has become a research hotspot in the field of energy harvesting. Energy harvester output power is the most important parameter in a vibration energy harvesting system. Assessing the harvester output power in different vibration environments is an important study issue to study. This thesis proposed a research method for harvester output based on the complex vibration environment simulated in the laboratory, a closed-loop control experimental system for the simulated vibration environment was established, the system can simulate a vibration environment with specific vibration frequency and acceleration, and automatically measure the harvester output power. Using FFT methods to analyse the harvester output voltage waveform, research the relationship between the harvester output power and the noise vibration signal frequency. Polynomial fitting modelling method is used for the harvester output power prediction in the 62.5Hz dominant frequency vibration environment. At the same time, researching the harvester output power in different dominant frequency and same vibration acceleration vibration environment which containing noise signal. Through the analysis of harvester output power, it was found that, for the case of the vibration environment dominant frequency is 62.5Hz, all noise frequency component of the vibration signal will reduce the output power of vibration energy harvester modelD, especially when the noise frequency is around 57.5Hz and67.5Hz, the output power of vibration energy harvester modelD is quite lower than the output power of harvester under the pure sinusoidal excitation signals. For the case of the vibration environment dominant frequency is not 62.5Hz, if the noise frequency component of the vibration signal close the harvester resonance frequency, it has a great impact on output power, and the output power of harvester is higher than the output power of harvester under the pure sinusoidal excitation signals. The presented research methods apply to most such studies, which can help user to analyse the effect of vibration noise on the harvester output and helps increase the harvester's output power. Research conclusions can provide user a reference in harvester selection.

  • 31.
    Correa, J.
    et al.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Wunderer, C. B.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Marras, A.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Okrent, F.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Lange, S.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Kuhn, M.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Niemann, M.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    Gottlicher, P.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany.
    Shevyakov, I.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany.
    Zimmer, M.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany.
    Krivan, F.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany.
    Boitrelle, B.
    DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany; Synchrotron SOLEIL L'Orme des Merisiers, Gifsur- Yvette Cedex, France.
    Guerrini, N.
    RAL (Rutherford Appleton Laboratory) / STFC, OX, U.K.
    Marsh, B.
    RAL (Rutherford Appleton Laboratory) / STFC, OX, U.K.
    Nicholls, T.
    RAL (Rutherford Appleton Laboratory) / STFC, OX, U.K.
    Sedgwick, I.
    RAL (Rutherford Appleton Laboratory) / STFC, OX, U.K.
    Cautero, G.
    Elettra Sincrotrone Trieste, Trieste, Italy.
    Giuressi, D.
    Elettra Sincrotrone Trieste, Trieste, Italy.
    Menk, R. H.
    Elettra Sincrotrone Trieste, Trieste, Italy.
    Pinaroli, G.
    Elettra Sincrotrone Trieste, Trieste, Italy; Universita degli Studi di Udine, Udine, Italy.
    Stebel, L.
    Elettra Sincrotrone Trieste, Trieste, Italy.
    Greer, A.
    DLS (Diamond Light Source), OX, U.K.
    Pedersen, U.
    DLS (Diamond Light Source), OX, U.K.
    Tartoni, N.
    DLS (Diamond Light Source), OX, U.K.
    Hyun, H. J.
    PAL (Pohang Accelerator Laboratory), Pohang, Korea.
    Kim, K. S.
    PAL (Pohang Accelerator Laboratory), Pohang, Korea.
    Rah, S. Y.
    PAL (Pohang Accelerator Laboratory), Pohang, Korea.
    Graafsma, Heinz
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL Center for Free-Electron Laser Science, Hamburg, Germany.
    The PERCIVAL soft X-ray Detector2018In: 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018, article id 8824727Conference paper (Refereed)
    Abstract [en]

    The PERCIVAL collaboration to develop a soft X-ray imager able to address the challenges of high brilliance light sources, such as new-generation synchrotrons and Free Electron Lasers, has reached one of its major milestones: a full 2-MegaPixel (P2M) system (uninterrupted 4 × 4 cm2 active area) has already seen its first light.Smaller prototypes of the device, a monolithic active pixel sensor based on CMOS technology, have already been fully characterised, and have demonstrated high frame rate, large dynamic range, and relatively high quantum efficiency.The PERCIVAL modular layout allows for clover-leaf like arrangement of up to four P2M systems. Moreover, it will be post-processed in order to achieve a high quantum efficiency in its primary energy range (250 eV to 1 keV).We will present the P2M system, its status and newest results, bring these in context with achieved prototype performance, and outline future steps. 

  • 32.
    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.

  • 33.
    Das, Moumita
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Bertilsson, Kent
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    GaN Based Converters for Battery Charging Application of Electric Vehicle2019In: IECON2019: 45th Annual Conference of the IEEE Industrial Electronics Society, IEEE, 2019Conference paper (Refereed)
    Abstract [en]

    The high frequency capability and low on-state losses of Gallium Nitride (GaN) transistors offer the potential to increase converter efficiency and/or reduce heatsink and passive component size. This paper investigates the use of GaN technology to enhance the performance of power factor correction (PFC) and LLC converters for battery charging applications. First the efficiency performance of non-isolated PFC converters using GaN transistors is compared by simulation, the asymmetric bridgeless PFC converter is shown to achieve the best efficiency, with a predicted figure of 99% in a 1MHz, 200W design. The predictions are validated by an experimental prototype using a GS66502B, GaN Systems E-mode GaN transistor. Then the efficiency comparison of the PFC and LLC converter using GaN devices for battery charging applications is included in the paper. The experimental results of the PFC converter with GaN devices are also included. Additionally, this paper includes the analysis and design of a common mode input filter for the GaN-based high frequency converters for battery charging application. The size of both the converters using GaN devices is reduced by 40% than the converters based on Si devices. The switching loss comparison of GaN and Si devices are also included in the paper.

  • 34.
    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.

  • 35.
    Du, Yijun
    et al.
    Univ Sci & Technol China, Hefei, Anhui, Peoples R China.
    Wu, Xiaopo
    Univ Sci & Technol China, Hefei, Anhui, Peoples R China.
    Sidén, Johan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Wang, Gang
    Univ Sci & Technol China, Hefei, Anhui, Peoples R China; Chinese Acad Sci, Beijing, Peoples R China.
    Design of ultra-wideband antenna with high-selectivity band notches using fragment-type etch pattern2020In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 62, no 2, p. 912-918Article in journal (Refereed)
    Abstract [en]

    By specifying objective functions defining the two bands to be notched with high roll-off criteria (ROCs), optimization searching for the best fragment-type etch pattern on ultra-wideband (UWB) antenna is implemented by using multi-objective optimization. The optimization with too many objective functions requires special treatment to improve the searching efficiency. In this design, two slits are preset on appropriate positions on different sides of the UWB radiator to constrain the decision space for etch pattern searching and yield two initial notched bands to speed up the optimization. For demonstration, a UWB patch antenna is designed with dual-band notches of ROC = 0.63 at WiMAX band and ROC = 0.65 at WLAN band. Both the simulation and measurement results indicate that there is significant improvement of the selectivity of the dual-band notches.

  • 36.
    Duan, Jiatong
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Optimization and development of the welding system for fiber-optic duct joints2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    At present, the fiber optic ducts are connected by a mechanical type of joint. In this method, two ducts cut in the right angle are pushed in from both sides of the

    joint, and takes approximately one second to joint ducts together. The problem with the existing joint technology is that if there is water inside of the joint, it will be damaged when the water freezes into ice, and then may cause leakage. There is a risk of explosion when compressed air to blow the fiber. Thus, a joint protection device (silicone rubber sleeve) was developed to seal the joint for protection utterly. However, this will cause the larger size of the entire joint and limit the number of single-duct joints next to each other in a multi-duct joint. Fiber optic ducts are made of High-Density Polyethylene, which is the best plastic for remelting and can be welded by using the electro-fusion welding method. Based on the thermoplasticity of this material, this thesis developed a plastic joint with a built-in conductive metal wire inside. The applied voltage will heat the wire, then remelt the duct surfaces to weld them together through the joint. The welding system uses a portable battery operating system, so there is no need to connect it to the grid. To prevent the battery

    from being damaged by supplying too much current, a capacitor bank is used to store high energy for the preheating joints. The system uses a microcontroller to control and monitor current and voltage to ensure uniform heating of the metal wire.

    Theemphasisof this thesis isplacedon the implementation of basic experiments to run the welding system. Multiple welding experiments show that the welding system can manually set parameters to control the welding current of different joints, thereby ensuring the welding quality. Using a 2.5Ω joint to weld ducts will approximately consume 120J from the battery, so a fully charged 42V, 4.4AH rechargeable battery can perform almost 5600 times of welding. The suitable range of joint resistance will decrease as the required energy consumption increases/ the welding time decreases.

  • 37.
    Ebadi, Seyed Morteza
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bayati, Mohammad Sajjad
    Ram, Siamak Bonyadi
    A Multipurpose and Highly-Compact Plasmonic Filter based on Metal-Insulator-Metal Waveguides2020In: IEEE Photonics Journal, ISSN 1097-5764, E-ISSN 1943-0655Article in journal (Refereed)
    Abstract [en]

    A multipurpose and ultra-compact nanoplasmonic wavelength filter based on stub structure in a metal-insulator-metal (MIM) waveguide is suggested and numerically investigated. A novel approach of connecting two stepped-like apertures to both input and output ports is applied to form Fabry-Perot (FP) cavities, which enabled the structure to act as a dual band-pass filter at wavelengths 1310 nm and 1550 nm. It is shown that the variation in cavities’ length allows to realize a long-wavelength cutoff filter, and cutoff wavelength can be easily tuned by adjusting the length of the cavities. Furthermore, it is revealed that increasing the gap between the stepped-like apertures and the cavities provides a triple band-pass at telecom wavelengths, e.g. 1267.5nm, 1414.19 nm, and 1644.7 nm. The tunable broadband high-pass wavelength filter is then achieved while the lengths of stepped-like apertures and stub resonators are set to be identical. Finally, a tunable nearly perfect absorber can be obtained by varying the width of stub resonators. Therefore, because of functionality, size, as well as efficiency the proposed plasmonic filter may greatly contribute to miniaturization of next generation of photonic integrated circuits (PICs), and find applications in on-chip integration and wavelength-division multiplexing (WDM) in optical communication systems.

  • 38.
    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

  • 39.
    Edrissi, Arian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Styrsystem till avloppspumpstation: Vägledning vid val av automationsteknik2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report the currently leading technologies for automation of sewage pump stations will be evaluated and compared. Based on this comparison a recommendation of a design will be done and the chosen control system will finally be assembled in a cabinet. The report shows that even thou there are energy savings to be done by using variable frequency drives it is rarely possible unless pumps are changed at the same time. When pumps are changed at the same time you have the opportunity to pick a pump that can handle the maximum inflow but at the same time have its best efficiency  point at lower speed. Pumps in sewage pump stations are often over dimensioned with regards to the most common inflow, lowering the speed will in this case result in lower efficiency and more losses. At one point the pump will not be able to overcome the static pressure in the system and will fail to produce any flow. Due to these reasons on/off control will be recommended which also is the most common method of today.

  • 40.
    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.

  • 41.
    Ganbat, Dashnyam
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Kartläggning av befintliga problem på Fatpacken i Nouryon samt lösning av ett av problemen: Prototypkonstruktion för en QR-kodavläsare2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This work includes a survey of an existing problems in one of the departments in Nouryon, called Fatpack.  The goal is to document more detailed description of problems that can be used to solve these in the future, but it was found that there was not enough reliable basis, such as costs and interrupts statics which needs a deeper study. That’s why a decision was made to document the problems as short descriptions. The purpose of this work was also to choose one of the problems and provide a technical solution using literature and web-based study. Based on interests and within the time frame the problem was chosen, where a controller is needed in production processing that can read the label of outgoing products. It was chosen to construct a Quick Response code scanner that controls the label content against outgoing product content. The focus was to define readability and swiftness of QR-code, reading and decoding. The most occurring library in Python programming to read and decode QR-code are ZBar and Zxing which were compared in this work. The result shows that Zbar has a fastest response time which was chosen to implement on a Raspberry pi 3 model B+ with a camera module v2.1 in real time. The Idea was verified by identify some elementary parameters such as maximum reading distance, angle of twisted emballage and response time with respect to size of QR-code that exists on the label. The prototype was verified and later proposed as a solution for Nouryon.

     

  • 42.
    Gaynullin, Bakhram
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    High accuracy low-cost NDIR sensing2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sensing gas concentrations using optical absorption offers valuable advantages over other methods ina wide variety of real-world applications from industrial processes to environmental change. One of the most rapidly developing detection techniques on the global market is the non-dispersive infrared method (NDIR). Sensors developed based on this technique satisfy a growing demand for low-cost, reliable and long-term maintenance-free solutions. The technologies available to support this field for sensor key components such as light sources, photo detectors, optic cavities, and electronic components, have advanced rapidly in recent years. This development has led to an increasing number of application fields, due to significant improvements in accuracy, sensitivity and resolution.

    However, this technique has limitations related to basic physical principles and sensor design performance. Variation in sensing environments’ temperature and pressure, the impact of water vapour presence and sensor component ageing are the most important interfering factors for investigation. Errors in measured values could be caused by any of these factors because they influence various sensor parts and the environment’s physical properties. The correct interpretation of error sources is one the most difficult and important tasks involved in designing stable, high-precision sensors.

    To facilitate investigations into measurement performance limitations, test equipment was developed along with test approaches capable of creating experimental conditions that exceed the tested sensor’ stolerances. The studied resolution limit for long-path sensors is about 100 ppb. For measurements in fresh air concentrations (approximately 400 ppm of CO2), this is equivalent to a precision of less than0.1%. The methods used to reduce possible inaccuracies due to various error sources’ impacts should possess compensatory capabilities and precisions that exceed this value.

    To improve the pressure compensation procedure’s performance, a complete advanced system that includes everything from a lab test bench to the supporting software and comprehensive calculation algorithm was developed. The test bench creates pressure conditions that deviate from the reference value by less than 0.2 mbar (or 0.02% of the standard pressure, 1013 mbar).

    One of this study’s major findings is the concentration range-independent pressure compensation method. The advanced conditions achieved with the test station also facilitated the discovery and characterisation of the sources of long-term drift in methane concentration measurement.

  • 43.
    Gaynullin, Bakhram
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design. Engineer.
    Hummelgård, Christine
    Mattsson, Claes
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Rödjegård, Henrik
    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.
    Efficient pressure compensation of low-cost NDIR sensors for environmental studiesArticle in journal (Refereed)
  • 44.
    Genetu Teggen, Linda
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Material identification using X-ray diffraction2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study reviews the theoretical and experimental aspects of the X-ray diffraction (XRD) technique and evaluates its use in identifying toxic elements or compounds in waste that has been incinerated. Many industries incinerate materials that contain large significant amounts of toxic elements, and these elements should be identified and re-moved to reduce environmental pollution. The aim of this project is to identify the elemental content of an incinerated ash sample, and to recommend a proper identification method when using XRD. Here, we test two ash samples (raw ash without any treatment and ash that has been stabilized by washing) using the software DIFFRAC.EVA that is integrated into Bruker’s diffractometer D2Phaser to match different diffraction patterns to identify the contents of the ash sample. Finally concluding the results XRF is more suitable than XRD for ash surveil-lance.

  • 45.
    Guo, Dongxue
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Project on Radon Dosimetry2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The World Health Organization lists radon as one of the 19 most important substances that cause cancer. As a naturally occurring harmful gas, Radon mostly exist in rocks, making caves, mines, etc. However, since Radon gas has great ability to dissolve in water, radon can travel to anywhere. This thesis introduces a newly designed Radon detector and tests its function. The detector is designed base on an alpha particle sensitive diode and the principle of electrostatic capture. The detector’s function is tested in both simulation and experiment. The diode size used in this experiment is 10*10mm2. The measured detection sensitivity is approximately 0.903 (counts/Bq/m3/h) with a channel height of 10mm, which is also verified by simulation.  For a channel height of 12 mm the simulation gives 1.06 (counts/Bq/m3/h) but the measurement gives a much lower value. The reason for that is not yet known. The detector is just a basic model, there are many ways to improve the detector performance in the future.

  • 46.
    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.

  • 47.
    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)
  • 48.
    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. 

  • 49.
    Hallin, Björn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Measurement of equipment effectiveness in a fully autonomous chemical plant2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Linde PLC AB have in combination with the opening of a new fully automated factory acquired the need for an equipment effectiveness measurement tool in order to monitor the availability, performance and quality output for different machines and workstations throughout their fully automated process chain. The overall aim of the project has been to carry out a preliminary study on how to implement such a monitoring system to be able to measure the data more precisely as well as identify possible bottlenecks and the root causes for process disturbances, downtimes and inactivity.

    The survey has been conducted using a deductive research approach by studying the internationally known theory of Overall Equipment Effectiveness (OEE). This theoretical framework together with a field study and a quantitative data analysis serves as the foundation for the survey’s results.

    The result has shown that OEE as a tool will help the company to better visualize and achieve their main production goals. The analysis is indicating a low but steady increase of the OEE for Carousel 1 at the given sampling frame which was expected due to the incompletion of the plant construction. The survey has also shown that the data extraction points from the PLC’s are not yet fully utilized which makes the equipment down-time hard to pinpoint to a specific improvement area.

    The main recommendation for Linde, based on this survey, is to increase the amount of logging datapoints to increase the understanding of stop times. After a successful implementation on Carousel 1, the next logical move would be to implement OEE analysis for the remaining carousels and other automated machines and processes within the plant.

    With the latest technology and while still in an early project phase, Linde are in a great position to fully implement OEE as a KPI for process improvements and machine utilization.

  • 50.
    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.

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