oru.sePublikationer
Change search
Refine search result
29303132333435 1551 - 1600 of 1837
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1551.
    Schwind, Markus
    et al.
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg.
    Miljkovic, Vladimir D.
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg.
    Zäch, Michael
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg.
    Gusak, Viktoria
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg.
    Käll, Mikael
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg.
    Zoric, Igor
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg.
    Johansson, Peter
    Örebro University, School of Science and Technology. Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Diffraction from Arrays of Plasmonic Nanoparticles with Short-Range Lateral Order2012In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 6, no 11, p. 9455-9465Article in journal (Refereed)
    Abstract [en]

    We have measured the angular distribution of light scattered off 2D plasmonic Al nanoparticle ensembles. We created.. these samples with disk-like nanoparticles, 175 and 500 nm in diameter, respectively, using hole-mask colloidal lithography and electron beam lithography. The nanoparticle arrangements In the samples display the Short-range order (but no long-range order) characteristic for an ensemble formed by random sequential adsorption. As a consequence of this, the ensemble scattering patterns can be quantitatively well described by combining the single-particle scattering pattern with a static structure factor that carries information about the diffraction effects caused by the short-range order of the ensemble. We also performed sensing experiments in which we monitored changes in the angle-resolved scattering intensity for a fixed wavelength as a function of the thickness of an ultrathin SiO2 coating covering the Al nanoparticles. The data show that the angle and strength of the main diffraction peak vary linearly, with SiO2 coating thickness In the range 1.5-4.5 nm and suggest that measurements of the scattering profile could be a competitive alternative to traditional transmission measurements in terms of sensitivity.

  • 1552.
    Seiler, Thomas-Benyamine
    et al.
    RWTH Aachen.
    Hollert, Henner
    RWTH Aachen.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Lost in translation?: Ways for environmental sciences to communicate about risk and research2013In: Environmental Sciences Europe, ISSN 2190-4715, E-ISSN 2190-4715, Vol. 25, no 8, p. 1-3Article in journal (Refereed)
    Abstract [en]

    This editorial is an introduction to a paper series on the communication of environmental sciences and risk,developed as an idea from a session at the 6th SETAC World Congress 2012.Environmental sciences are at the heart of what people affect in their daily lives: environmental quality, safe food,clean air, fresh water - and hence crucial for sound public health. Why aren't we in their daily minds? How shouldwe communicate to get there? Communication means to convey meaningful information to create sharedunderstanding. But only a minority of scientists have knowledge about the principles of science communicationand even less than these are certainly up-to-date with modern communication concepts. The paper series “Lost intranslation? Ways for environmental sciences to communicate about risk and research” collates views andperspectives on science and risk communication from different angles to initiate a broader discussion on thecommunication about research findings in environmental sciences.

  • 1553.
    Sejfic, Melli
    Örebro University, School of Science and Technology.
    Method Improvement for the Determination and Quantification of PCBs in the Muscle Tissues of Arctic Char (Salvelinus salvelinus) and European Whitefish (Coregonus acronius) from Lake Vättern, Sweden2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Lake Vättern has been contaminated with high levels of polychlorinated biphenyls (PCBs) for decades, which could be due to the release of wastes from industries and urban communities surrounding the water system. This has especially had a negative effect on fatty fishes, which could accumulate large amounts of persistent organic pollutants (POPs) and thereby also become a source of environmental toxicants to humans through consumption. Most PCB analysis only quantify a handful of congeners, the so called indicator-PCBs (I-PCBs), but this might leave out important information. In this study, an existing analytical method was improved by supplementing with additional congeners to detect a larger set of PCB congeners in Arctic char (Salvelinus salvelinus) and European whitefish (Coregonus acronius) caught from Lake Vättern, Sweden. New pre-packed multilayer silica columns from CAPE technologies were tested and used to pretreat the fish samples prior to analysis with a Gas Chromatograph coupled to low-resolution Mass Spectrometer using Atmospheric Pressure Ionization (API GC/MS). It was found that modifications of the clean up method for PCBs were necessary, such as lowering the amount of hexane in the washing step and combining the two eluent fractions. The Arctic char and the European whitefish showed a fat content of 0.18% and 0.74%, respectively. Concentrations of detected congeners ranged from 0.5 to 1470 pg g-1 fresh weight (fw) in Arctic char and varied between 1.2 to 6550 pg g-1 in European whitefish. For Arctic char and European whitefish, the WHO2005-TEQ values were 0.4 pg g-1 fw and 0.6 pg g-1 fw, respectively. The greatest total PCB concentration of 25900 pg g-1 was measured in European whitefish. The total concentration of I-PCBs (#28, 52, 101, 138, 153, 180) was 3710 pg g-1 for the Arctic char and 13900e pg g-1 for the European whitefish. All obtained results were lower than those reported from other studies. Constructed congener profiles show that the two species have similar ratios of PCB #138 and #153. Differences are observed of PCBs with a higher chlorination grade, probably due to differences in migration patterns, habitats of the lake, diets, metabolism or bioaccumulation.

  • 1554.
    Selimanovic, Armin
    et al.
    Örebro University, School of Science and Technology.
    Bergman, Christoffer
    Nuläges- och processanalys av tillverkningsflöde2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    We have done our examination assignment at Plåtspecialisten AB in Örebro. Plåtspecialisten are now in a state where they are subcontractors to a rapidly growing customer. The customer demands higher quality and delivery precision, this in combination with the growth of the customer demands an improved future production of the subcontractor.

    The thesis consists of several parts. The whole thesis is based on a situation analysis to provide an overview. Based on the current situation analysis, we have chosen appropriate methods and tools that the company can independently practice. The methods and tools we leave behind us are value stream mapping, 5S, process thinking and how to improve the operation of the manufacturing processes.

    The mapping of the current situation began with the study of production scheduling, where we compared the scheduled time versus actual time. Data for this is from the company's MPS system. To obtain a complete picture we went on to do value stream mapping, data for this was also taken from the company's MPS system. A total of eight value stream maps were created.

    The study of production planning and value stream maps are the basis for the suggested methods and tools that will lead to more efficient work.

  • 1555.
    Sers, Rickard
    et al.
    Örebro University, School of Science and Technology.
    Wiberg, Victor
    Örebro University, School of Science and Technology.
    Konstruktion av CNC-Router2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    AASS (Applied Autonomous Sensor Systems, Center for Applied Autonomous Sensor) works with research in autonomous systems. Their major application is the development of such systems for the automotive industry as well for the elderly.

     AASS, have a desire for a simple model of a CNC milling machine for milling smaller parts for prototyping. The focus should be on cost when precision is not of great interest.

     The mission is to develop a design of a CNC router with three axes with a workspace of 600x450x150mm. The machine should be able to cut soft materials such as wood, plastics as well as soft aluminum.

     The result is a three-axis CNC router which is driven by three stepper motors which are coupled to respective ball screw. The Cnc router has a workspace of about 600x450x150mm. It is capable of cutting with cutting forces up to 150N without deformations that will produce large errors in values of processed detail. The design consists of main body of aluminum profiles available at Örebro University. The movable parts consist of Quadro Tables manufactured by Rollco. The design provides a good solution to a relatively low cost.

  • 1556.
    Setterberg, Joel
    et al.
    Örebro University, School of Science and Technology.
    Elsgard, Jonatan
    Örebro University, School of Science and Technology.
    IMPLEMENTERING AV PHONGLJUSSÄTTNINGI 2D-SPELMILJÖ2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In recent years, a new trend in the gaming industry has emerged since a large part of the games have

    gone back to the two-dimensional environments that were more common in the early days of the

    video games history . This is due to mobile phones and their games have taken more and more

    space on the market and they are often two-dimensional because of the limited harware. The twodimensional

    games have traditionally never had any dynamic lighting , they have consisted of premade

    graphics with predetermined intensities , which means that the games may look flat.

    But in other areas within the gaming industry, especially three-dimensional games, the evolution of

    dynamic lighting techniques have come a long way. The problem with these methods is that they

    require the object's normals, which are not normally available in two-dimensional images.

    Today mobile phones are powerful and capable of much heavier computations than they did just a

    few years ago. Therefore, we examined the possibility of implementing dynamic lighting in a twodimensional

    games on Androidbased mobile phones. To accomplish this it required that we

    investigated methods to generate normals for two-dimensional graphics.

    In order to create a full game we also implemented features such as collision handling, artificial

    intelligence and procedural generation of maps.

  • 1557.
    Shahid, Zahraa
    Örebro University, School of Science and Technology.
    Design and development of intelligentapartments2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Developments in the elds of Ambient Intelligent Environments (AmIE) and UbiquitousComputing environments have provided the opportunity to develop assistive technologiesto help individuals who need medical care on a daily basis; in fact the integration betweenrobots, smart actuators and sensors can ease the execution of several domestic tasks.Since building a real physical IE is costly, simulations have opened the door to variouspossibilities to design, test and explore dierent scenarios of virtual IE. This thesisproject is aimed at developing an agile prototyping toolkit that provides the means forusers to simulate smart environments for robotics, AmIE and Ubiquitous Computingelds. This toolkit leverages well known software middlewares: Robot Operating System(ROS) and Gazebo. The former is a middleware providing access to several state of theart techniques used in robotics as well as to a variety of hardware platforms. The latterprovides a simulator which allows to reproduce 3D environments as well as roboticplatforms. Besides reproducing realistic scenarios, the proposed framework easily allowsto go beyond a single apartment: in particular in this thesis a double oor building hasbeen taken into account. Performances about this scenario and the integration withexisting middlewares are also provided.

  • 1558.
    Shahin, Firas
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Rickard
    Örebro University, School of Science and Technology.
    Övergå till högre stålhållfasthet2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project is about a transition to higher steel strength. The transition is from steel strength

    S355 to S690 in HEA- profiles for column and wind trestles. The choice to do this project

    comes from the fact that it would be interesting to see if there are any profits in switching to

    higher steel strength.

    During the project process it was found that smaller steel profiles could be chosen when S690

    was selected instead of the traditional S355. For this particular steel hall the column size was

    reduced by three column profiles and for the wind trestles only one profile could be reduced.

    When the steel strength S690 is used, the cross class 4 is obtained for a few HEA- profiles.

    This leads to more extensive dimensioning performance compared to the steel strength S355

    which reaches only the cross class 3 as the highest.

    At present there is an financial incentive to choose higher steel strength according to the

    approximate cost analyzes carried out during the project process.

    With the higher steel strength, the steel amount becomes lower for the steel hall. This leads to

    less transport to the construction site. Which is beneficial both for an environmental

    perspective and economic perspective.

  • 1559.
    Shahror, Rami Ahmad Nawaf
    Örebro University, School of Science and Technology.
    Alpha and Beta Androgen Receptors Expression in Three-Spiend Sticklenack Kidney2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Androgen receptors (AR) play important role in male secondary sex diferentiationin most of vertebrates. Spiggin in male three spiend stickleback (Gasterosteus aculeatus ) is under androgenic control and is used to build their nest and is produced by kidney cells .The ARβ is well characterize but ARα has not yet been characterized in stickleback.

    A cDNA from male stickleback kidney cells was obtained and primers were designed for ARα and ARβ. The expression of  ARα and ARβ was determined by using PCR and gel electrophoresis. More experiments have to be performed to clarify the characters of ARα and to understand the mechanism of regulation for both ARs in stickleback fish.

  • 1560.
    Shahror, Rami Ahmad Nawaf
    Örebro University, School of Science and Technology.
    Characterization of the Transcription Factor NF‐Y in the Regulation of Zona Pellucida Genes in Zebrafish Ovary2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Zona pellucida glycoproteins (ZP) are important proteins for maturation of the oocytes in eukaryotes, these proteins are encoded by cluster of zp genes. zp2.3 and zp3.5 genes are expressed during the developing and maturation of the oocytes in zebrafish ovaries. Both of the gens have a CCAAT box in their promoter regions, playing a big role in the expression of the both genes in zebrafish oocytes. The transcription of the genes in the eukaryotes requires transcription factors to initiate and promote the transcription, the transcription factors can bind to the promoter region and initiate the transcription process. The nuclear factor y (NFY) regulates the genes by binding to the CCAAT boxes in their promoter regions, it consist from many subunit such as NF-YA and NF-YB. Here in this study we characterize the expression pattern of NF-YA and NF-YB by screening these genes expression in several organs and tissues, also to determine its roles in the expression of the zp2.3 and zp3.5 genes in the adultzebrafish ovary.

  • 1561.
    Shao, Lei
    et al.
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Yang, Zhong-Jian
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Andren, Daniel
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Johansson, Peter
    Örebro University, School of Science and Technology. Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Käll, Mikael
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Gold Nanorod Rotary Motors Driven by Resonant Light Scattering2015In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 9, no 12, p. 12542-12551Article in journal (Refereed)
    Abstract [en]

    Efficient and robust artificial nanomotors could provide a variety of exciting possibilities for applications in physics, biology and chemistry, including nanoelectromechanical systems, biochemical sensing, and drug delivery. However, the application of current man-made nanomotors is limited by their sophisticated fabrication techniques, low mechanical output power and severe environmental requirements, making their performance far below that of natural biomotors. Here we show that single-crystal gold nanorods can be rotated extremely fast in aqueous solutions through optical torques dominated by plasmonic resonant scattering of circularly polarized laser light with power as low as a few mW. The nanorods are trapped in 2D against a glass surface, and their rotational dynamics is highly dependent on their surface plasmon resonance properties. They can be kept continuously rotating for hours with limited photothermal side effects and they can be applied for detection of molecular binding with high sensitivity. Because of their biocompatibility, mechanical and thermal stability, and record rotation speeds reaching up to 42 kHz (2.5 million revolutions per minute), these rotary nanomotors could advance technologies to meet a wide range of future nanomechanical and biomedical needs in fields such as nanorobotics, nanosurgery, DNA manipulation and nano/microfluidic flow control.

  • 1562. Shegai, Timur
    et al.
    Johansson, Peter
    Örebro University, School of Science and Technology.
    Langhammer, Christoph
    Kall, Mikael
    Directional scattering and hydrogen sensing by bimetallic Pd-Au nanoantennas2012In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 12, no 5, p. 2464-2469Article in journal (Refereed)
    Abstract [en]

    Nanoplasmonic sensing is typically based on quantification of changes in optical extinction or scattering spectra. Here we explore the possibility of facile self-referenced hydrogen sensing based on angle-resolved spectroscopy. We found that heterodimers built from closely spaced gold and palladium nanodisks exhibit pronounced directional scattering, that is, for particular wavelengths, much more light is scattered toward the Au than toward the Pd particle in a dimer. The effect is due to optical phase shifts associated with the material asymmetry and therefore highly sensitive to changes in the permittivity of Pd induced by hydrogen loading. In a wider perspective, the results suggest that directional scattering from bimetallic antennas, and material asymmetry in general, may offer many new routes toward novel nanophotonic sensing schemes.

  • 1563.
    Sheko, Ahmad
    Örebro University, School of Science and Technology.
    Claudin -3 and Claudin -5 gene expression in colon carcinoma2012Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
  • 1564.
    Sher, Darin
    et al.
    Örebro University, School of Science and Technology.
    Andersson, Nathalie
    Örebro University, School of Science and Technology.
    Samverkan och kommunikation mellan produktion och projektering: Hur kan dom sex arbetssätten underlätta och förbättra arbetet?2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The thesis work is a study of existing systems to provide a basis for improvement in

    communication between construction planning and production in the construction industry.

    Six different ways of working were chosen to investigate how beneficial they actually are.

    Participation, feedback, PM at revision, specification, technical assistant- and constructor

    planer at the construction site, were the six ways of working on which the study was based.

    How are they used today, how can they be integrated and how beneficial they are, were

    questions that will be answered in this study.

    With the help of knowledge from the education, studies and different working methods used

    previously, as well as a case study, the questions have been answered. In order to have a wellfounded

    and reliable result, several different professions and coworkers in the industry have

    been used in the preliminary work. The choice of supervisory companies was also chosen

    under the same conditions.

    The conclusion of the study was that the six working methods could be integrated and that

    some were already partially tested. By improving a method, several others will be improved at

    the same time. Therefore, in the end, we want to emphasize the importance of placing time

    and focus on integrating the methodes in this project

  • 1565.
    Sherikov, Alexander
    Örebro University, School of Science and Technology.
    Model predictive control of a walking bipedal robotusing online optimization2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Humanoid robotics is a challenging and promising research field. Legged locomotion

    is one of the most important aspects of it. In spite of the progress

    achieved in the last years in control of walking robots, many problems are yet

    to be resolved. The inherent complexity of such robots makes their control a

    difficult task even on the modern hardware. In order to address this issue approximate

    models and high performance algorithms are employed. This thesis

    is focused on the model predictive control of a walking bipedal robot, which

    is approximated by an inverted pendulum, using online optimization. A special

    emphasis is made on the solvers that exploit the structure of quadratic optimization

    problems in the context of model predictive control. Two methods for

    solution of these problems are implemented: primal active set and primal logarithmic

    barrier methods. They are tested and compared in a simulation and on

    a humanoid robot. A software module for control of the Nao humanoid robot

    is developed for this purpose.

  • 1566.
    Showan, Kadir
    et al.
    Örebro University, School of Science and Technology.
    Lak, Hogar
    Effektiviseradtidsplanering-Platsbaserad tidplanering och traditionell tidplanering2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish construction industry can develop a variety of things to efficiency production

    time. The goal of production scheduling is to create conditions for good production results at

    each building site.

    Gantt scheduling has been used as a planning tool for a long time. The plan gives a clear

    picture of what will be done and when it should be done. It has both its advantages and

    disadvantages. Today’s technologies offer great opportunities for improvement of the overall

    picture of the building project. This provides opportunities to make a schedule without

    glitches, air and collisions. In particular, time can be saved which has a positive impact on the

    economy and profits.

    Vico Schedule Planner (V-SP) has been studied to obtain a picture of if the program is

    suitable for planning. A timetable for a real project has been implemented in V-SP by aid of

    information from the project calculations and 3D model. The schedule has been planned in

    Flowline based on location based scheduling, but the Gantt schedule was also obtained.

    Setting a timetable in V-SP reduces risks, glitches, air and collisions. A more complete picture

    is obtained where these problems become apparent. The project can receive a more profitable

    and efficient building delivery time. A steady resource use level can be obtained and this is

    highly appreciated.

  • 1567.
    Showan, Kadir
    et al.
    Örebro University, School of Science and Technology.
    Lak, Hogar
    Örebro University, School of Science and Technology.
    Effektiviseradtidsplanering-Platsbaserad tidplanering och traditionell tidplanering2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish construction industry can develop a variety of things to efficiency production

    time. The goal of production scheduling is to create conditions for good production results at

    each building site.

    Gantt scheduling has been used as a planning tool for a long time. The plan gives a clear

    picture of what will be done and when it should be done. It has both its advantages and

    disadvantages. Today’s technologies offer great opportunities for improvement of the overall

    picture of the building project. This provides opportunities to make a schedule without

    glitches, air and collisions. In particular, time can be saved which has a positive impact on the

    economy and profits.

    Vico Schedule Planner (V-SP) has been studied to obtain a picture of if the program is

    suitable for planning. A timetable for a real project has been implemented in V-SP by aid of

    information from the project calculations and 3D model. The schedule has been planned in

    Flowline based on location based scheduling, but the Gantt schedule was also obtained.

    Setting a timetable in V-SP reduces risks, glitches, air and collisions. A more complete picture

    is obtained where these problems become apparent. The project can receive a more profitable

    and efficient building delivery time. A steady resource use level can be obtained and this is

    highly appreciated.

  • 1568.
    Siddiqui, J. Rafid
    et al.
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Driankov, Dimiter
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Towards visual mapping in industrial environments: a heterogeneous task-specific and saliency driven approach2016In: 2016 IEEE International Conference on Robotics and Automation (ICRA), Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 5766-5773, article id 7487800Conference paper (Refereed)
    Abstract [en]

    The highly percipient nature of human mind in avoiding sensory overload is a crucial factor which gives human vision an advantage over machine vision, the latter has otherwise powerful computational resources at its disposal given today’s technology. This stresses the need to focus on methods which extract a concise representation of the environment inorder to approach a complex problem such as visual mapping. This article is an attempt of creating a mapping system, which proposes an architecture that combines task-specific and saliency driven approaches. The proposed method is implemented on a warehouse robot. The proposed solution provide a priority framework which enables an industrial robot to build a concise visual representation of the environment. The method is evaluated on data collected by a RGBD sensor mounted on a fork-lift robot and shows promise for addressing visual mapping problems in industrial environments.

  • 1569.
    Siebers, Peer-Olaf
    et al.
    School of Computer Science, Nottingham University, Nottingham, UK.
    Klügl, Franziska
    Örebro University, School of Science and Technology.
    What Software Engineering Has to Offer to Agent-Based Social Simulation2017In: Simulating Social Complexity: A Handbook / [ed] Bruce Edmonds, Ruth Meyer, Springer, 2017, 2, p. 81-117Chapter in book (Refereed)
    Abstract [en]

    In simulation projects, it is generally beneficial to have a toolset that allows following a more formal approach to system analysis, model design and model implementation. Such formal methods are developed to support a systematic approach by making different steps explicit as well as providing a precise language to express the results of those steps, documenting not just the final model but also intermediate steps. This chapter consists of two parts: the first gives an overview of which tools developed in software engineering can be and have been adapted to agent-based social simulation; the second part demonstrates with the help of an informative example how some of these tools can be combined into an overall structured approach to model development.

  • 1570.
    Sik, Robin
    Örebro University, School of Science and Technology.
    A New Model for Deformation of Carton Board Packages by Manual Handling2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes a ten weeks long thesis done for Tetra Pak. The work comprises 15 credits at a C-level. The purpose was to test how carton products are affected by the treatment of the consumers. The goal of this project was that by the use of a FE-software be able to measure the force distributions over the surface of a carton board package when it is affected by the pressure of a thumb. The report describes the process and the approach that made it possible to solve this problem.

    To get a deeper understanding of what this problem included the thumb anatomy and mechanical properties were studied, thereafter a thumb were modeled in the software Creo Parametric2.0. This CAD-thumb were then simulated in a scenario where it was pressed against a hard surface in the program Ansys Workbench 14.5 to ensure that it would work and behave like a real thumb would had done. In a last step, the thumb were pressed down against a carton board package in Ansys APDL (Ansys Parametric Design Language) and the results of this has been analyzed. This has been done both with and without friction to compare different scenarios. It was found that it was possible that by means of a FE-program solve this task.

  • 1571.
    Silfverdal, Martina
    Örebro University, School of Science and Technology.
    Material Degradation at Coil Bends in a VCM Plant2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The focus of this thesis is to map the material degradation mechanisms causing specific damages in theU-bends in a reactor of a Vinyl Chloride Monomer plant. The coils are used as a cooling-and temperature regulation-system of an exothermaloxychlorination process to 250ºC. The exothermal process naturally increases to 2000ºC. If this is not regulated a lot of unwanted things can happen, as a VCM plant explosion. The coils are in contact with two environments. The inner environment consists of water and steam and the outer environment consists of high temperature gases.

    This thesis is divided into two steps. First step was a literature study consisting of studies of material degradation at various piping systems, fields of corrosion mechanisms, VCM process and fluid dynamics. The second step was done by investigating the damage. The damage has the appearance of a penetrated hole. The method was performed by splitting up the investigation to internal and external surface. The internal surface of the bend was investigated by two steps; visual inspections with different laboratory equipment and fluid dynamic investigation with CFD simulations. The internal surface had several patterns of erosion corrosion damages. The external surface of the bend was investigated by visual inspections and had three marks; thickness decreasing, uniformed attack and erosion corrosion pattern. A further investigation could focus on choosing material that correspond better to the material degradation mechanisms that were found in this thesis. 

  • 1572.
    Silva-Lopez, Lia Susana d.C.
    et al.
    Örebro University, School of Science and Technology.
    Broxvall, Mathias
    Örebro University, School of Science and Technology.
    Empirical methods for evaluating properties of configuration planning algorithms2013In: Evolving Ambient Intelligence: AmI 2013 Workshops, Dublin, Ireland, December 3-5, 2013. Revised Selected Papers / [ed] O'Grady et. al., Springer International Publishing , 2013, p. 114-119Conference paper (Refereed)
    Abstract [en]

    As the field of configuration planning grows, so does the need for objective comparisons of algorithms and results. As the community stands today, different approaches to formalise and solve the problem at hand exist, and little or no importance has been given to compare results of different research groups. In this paper we summarize the definitions used by a few different research groups, and we explain two empiric method for comparing planning algorithms, based on statistics. While the methods themselves do not solve all the problems of comparative studies, it is a first step towards numerically comparing performances of the different configuration planning methods proposed by the community.

  • 1573.
    Silva-Lopez, Lia Susana del Carmen
    et al.
    Örebro University, School of Science and Technology.
    Ullberg, Jonas
    Örebro University, School of Science and Technology.
    Karlsson, Lars
    Örebro University, School of Science and Technology.
    On combining a context recognition system and a configuration planner for personalised ambient assisted living2013In: Communications in Computer and Information Science / [ed] Juan Carlos Augusto, Reiner Wichert, Rem Collier, David Keyson, Ali Salah, and Ah-Hwee Tan, Örebro: Örebro universitet , 2013Conference paper (Refereed)
  • 1574.
    Silverlycke, Peter
    Örebro University, School of Science and Technology.
    Vidareutveckling av grafkomponent2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report covers the further development of a chart component. The component could display a linechart with real number datapoints at the beginning. The chart component was part of as software called Tunnel Manager, developed by Sogeti for Atlas Copco. Tunnel Manager is used in combination with Atlas Copcos drilling rig Boomer. The charts added were barchart with support for several dataseries, stacked barchart with support for stacked dataseries and piechart. A new datapoint type for date and time was added. Grouping of data for the barcharts was also added.  Extended information was shown when the mouse pointer was held over a diagram, a tooltip. Zoom and panning in the charts was implemented, allowing the user to view some parts in detail. 

    The report also covers an investigation. The investigation finds out what kind of information, and what kinds of charts Atlas Copco had need of in the future in Tunnel Manager. There was a great need for displaying information in charts to get a good base for decision making. The information was needed for planning and maintenance of the drilling rigs. 

    When a lot of information is gathered from different sources a good way is needed for compilation and displaying of the information. Charts are a very good way of doing this. The carts need to follow a set of basic rules to be trustworthy. For example if several charts is to be compared, they need to have the same scale, to make it easier to compare. The further development of the chart component took these rules into account and it made it suitable for usage in production.

  • 1575.
    Simic, André
    et al.
    Örebro University, School of Science and Technology.
    Cicek, Benjamin
    Örebro University, School of Science and Technology.
    Projektrapportering HRM mobil2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes a thesis conducted at Flex Datasystem with a view to further developing Flex HRM mobile. Our task was to implement the project reporting in the module Flex Tid, which means that users can register or edit various projects via mobile devices. We used JavaScript, HTML5, CSS3 and also various frameworks to pursue our work.

  • 1576.
    Sinioja, Tim
    Örebro University, School of Science and Technology.
    Development of a Liquid Chromatography Method to Separate and Fractionate EPA’s 16 Priority Polycyclic Aromatic Hydrocarbons (PAHs)2016Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Polycyclic Aromatic Hydrocarbons (PAHs) are persistent, toxic and carcinogenic environmental pollutants consisting of two or more aromatic rings. The estimation of the toxicity of PAHs can be challenging and time-consuming due to the complexity of PAH-mixtures found in the environment, for example at contaminated sites. To solve the problem of a high complexity, PAH-mixtures can be divided into fractions. In the present study, Normal Phase (NP) and Reverse Phase (RP) Liquid Chromatography (LC) methods were evaluated and developed to separate and fractionate 16 U.S. Environmental Protection Agency’s (EPA) priority PAHs. Two stationary and six mobile phases, different column temperatures, flow rates, injection volumes, gradient and isocratic elutions were evaluated in order to achieve the best separation and fractionation. Best separation of PAHs was achieved with the RP-LC method using a phenyl stationary phase and gradient elution with mixture of methanol, acetonitrile and water. Fractionation was performed based on PAHs’ retention time windows, as well as peaks’ threshold and slope values. The elution order of fractions was verified by identification and quantification of the PAHs by GC-MS. Fractionation of a soil extract with the developed RP-LC method resulted in successful separation and fractionation of five EPA’s priority PAHs naphthalene, fluorene, phenanthrene, anthracene and chrysene, as well as two non-priority PAHs carbazole and 4H-Cyclopenta[d,e,f]phenanthrene. The study shows that developed RP-LC method can be further optimized to fractionate complex mixtures of alkyl substituted, oxygenated and other polycyclic aromatic compounds (PACs).

  • 1577.
    Sinioja, Tim
    Örebro University, School of Science and Technology.
    "Source characterization of soils contaminated with Polycyclic Aromatic Compounds (PACs) by use of Partial Least Squares Discriminant Analysis (PLS-DA)"2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Polycyclic aromatic compounds (PACs) are organic compounds that include several sub-groups of toxic, persistent and carcinogenic environmental pollutants consisting of two or more non-substituted or substituted aromatic rings. Due to the complexity of PAC-mixtures found in the environment it can be challenging and time-consuming to track the sources of contamination. In the present study, multivariate data analysis (MVDA) models, such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were applied to track sources of PACs at contaminated sites. Based on the chemical profile of 78 PACs obtained in GC-MS analysis of soils, 26 observations were classified according to their petrogenic, pyrogenic or urban background soil origin. Two soil samples of unknown origin collected at a contaminated site in Mjölby, Sweden, were successfully fitted to the validated PLS-DA model and their origins were determined as petrogenic. The study shows that validated PLS-DA models can be applied to predict the petrogenic, pyrogenic and urban background soil origins of samples collected at PAC contaminated sites, thus to track the sources of contamination. It is also concluded that 16 U.S. Environmental Protection Agency’s (EPA) priority polycyclic aromatic hydrocarbons (PAHs) are not sufficient to predict the origin of contamination with PCA or PLS-DA.

  • 1578.
    Sjöberg Lind, Ylva
    et al.
    Linköping University Hospital, Sweden.
    Lind, P. Monica
    Occup and Environ Medicine, UU, Sweden.
    Salihovic, Samira
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    POPs are associated with left ventricular systolic and diastolic dysfunction2012In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 211, no Supplement, p. S83-, article id P11-13Article in journal (Refereed)
  • 1579. Sjöberg Lind, Ylva
    et al.
    Lind, P. Monica
    Salihovic, Samira
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Lind, Lars
    Circulating levels of persistent organic pollutants (POPs) are associated with left ventricular systolic and diastolic dysfunction in the elderly2013In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 123, p. 39-45Article in journal (Refereed)
    Abstract [en]

    Background and objective: Major risk factors for congestive heart failure (CHF) are myocardial infarction, hypertension, diabetes, atrial fibrillation, smoking, left ventricular hypertrophy (LVH) and obesity. However, since these risk factors only explain part of the risk of CHF, we investigated whether persistent organic pollutants (POPs) might also play a role.

    Methods: In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, left ventricular ejection fraction, (EF), E/A-ratio and isovolumic relaxation time (IVRT), were determined by echocardiography and serum samples of 21 POPs were analyzed in serum measured by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) in 998 subjects all aged 70 years.

    Results: In this cross-sectional analysis, high levels of several of the polychlorinated biphenyls (PCB congeners 99, 118, 105, 138, 153, and 180) and octachlorodibenzo-p-dioxin (OCDD) were significantly related to a decreased EF. Some POPs were also related to a decreased E/A-ratio (PCBs 206 and 209). All the results were adjusted for gender, hypertension, diabetes, smoking, LVH and BMI, and subjects with myocardial infarction or atrial fibrillation were excluded from the analysis.

    Conclusions: Circulating levels of POPs were related to impairments in both left ventricular systolic and diastolic function independently of major congestive heart failure risk factors, suggesting a possible role of POPs in heart failure. (C) 2013 Elsevier Inc. All rights reserved.

  • 1580.
    Sjöberg, S.
    et al.
    IGV, Stockholm University, Stockholm, Sweden .
    Rattray, J. E.
    IGV, Stockholm University, Stockholm, Sweden .
    Callac, N.
    IGV, Stockholm University, Stockholm, Sweden .
    Allard, Bert
    Örebro University, School of Science and Technology.
    Skelton, A.
    IGV, Stockholm University, Stockholm, Sweden .
    Dupraz, C.
    IGV, Stockholm University, Stockholm, Sweden .
    Ivarsson, M.
    Department of Paleobiology and NordCEE, Swedish Museum of Natural History, Stockholm, Sweden .
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Sjöberg, Viktor
    Örebro University, School of Science and Technology.
    Putative Biogenic Signature found in Extremely REE Enriched Black Substance, Ytterby Mine, Sweden2015In: Goldschmidt Abstracts, 2015Conference paper (Refereed)
    Abstract [en]

    Characterization of a black substance seeping from fractured bedrock in a subterranean tunnel revealed a manganese and calcium bearing substance highly enriched in rare earth elements (REE). This tunnel is dry and at shallow depth and was built to convert the former Ytterby mine, into a fuel deposit for the Swedish Armed Forces. To keep the tunnel dry, groundwater level is kept below its natural level which has resulted in oxidizing conditions in a previously dysoxic or anoxic environment. The deposition of the substance therefore occurs in a dark and moist environment which was exposed to changing redox conditions.

    Geochemical analysis show that the substance is enriched in REEs with concentrations one to two orders of magnitude higher than in the surrounding rocks. X-ray diffraction spectra indicate that the main component is birnessite. SEM revealed an internal lamination of these Mn-oxides implying an iterative change in production. Previous results show that REE occurrences in Ytterby are localized within pegmatites in the mine. It is thus suggested that Mn colloids, suspended in the local groundwater, work as metal traps and contribute to the mobility of the REEs. The black substance is suspected to act as a sink for these metals in the Ytterby mine area.

    The influence of microorganisms on the accumulation of Mn-oxides appears to be important. The occurrence of the C31 to C35 extended side chain hopanoids among the identified biomarkers provides evidence of bacterial presence in the depositional environment. The abiotic vs biotic origin of the precipitated manganese was investigated by electron paramagnetic resonance spectroscopy. The substance is composed of two or more components, with one part having a biogenic signature. Ongoing investigations of the microbial communities and the REE accumulation processes include δ13C analysis of the extracted lipids, DNA deep sequencing, quantitative PCR and sequential leaching

  • 1581.
    Sjöberg, Susanne
    et al.
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Allard, Bert
    Örebro University, School of Science and Technology.
    Rattray, Jayne E.
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Callac, Nolwenn
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Grawunder, Anja
    Institute of Geosciences, Friedrich Schiller University of Jena, Jena, Germany.
    Ivarsson, Magnus
    Department of Paleobiology, Swedish Museum of Natural History, Stockholm, Sweden.
    Sjöberg, Viktor
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Skelton, Alasdair
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Dupraz, Christophe
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Rare earth element enriched birnessite in water-bearing fractures, the Ytterby mine, Sweden2017In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 78, p. 158-171Article in journal (Refereed)
    Abstract [en]

    Characterization of a black substance exuding from fractured bedrock in a subterranean tunnel revealed a secondary manganese oxide mineralisation exceptionally enriched in rare earth elements (REE). Concentrations are among the highest observed in secondary ferromanganese precipitates in nature. The tunnel is located in the unsaturated zone at shallow depth in the former Ytterby mine, known for the discovery of yttrium, scandium, tantalum and five rare earth elements.

    Elemental analysis and X-ray diffraction of the black substance establish that the main component is a manganese oxide of the birnessite type. Minor fractions of calcite, other manganese oxides, feldspars, quartz and about 1% organic matter were also found, but no iron oxides were identified. The Ytterby birnessite contains REE, as well as calcium, magnesium and traces of other metals. The REE, which constitute 1% of the dry mass and 2% of the metal content, are firmly included in the mineral structure and are not released by leaching at pH 1.5 or higher. A strong preference for the trivalent REE over divalent and monovalent metals is indicated by concentration ratios of the substance to fracture water. The REE-enriched birnessite has the general formula Mx(Mn3+,Mn4+)2O4·(H2O)n with M = (0.37–0.41) Ca + 0.02 (REE + Y), 0.04 Mg and (0.02–0.03) other metals, and with [Mn3+]/[Mn4+] = 0.86–1.00.

    The influence of microorganisms on the accumulation of this REE enriched substance is demonstrated by electron paramagnetic resonance spectroscopy. Results show that it is composed of two or more manganese phases, one of which has a biogenic signature. In addition, the occurrence of C31 to C35 extended side chain hopanoids among the identified lipid biomarkers combined with the absence of ergosterol, a fungal lipid biomarker, indicate that the in-situ microbial community is bacterial rather than fungal.

  • 1582.
    Sjöberg, Susanne
    et al.
    Dept of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Allard, Bert
    Örebro University, School of Science and Technology.
    Rattray, Jayne E.
    Dept of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Sjöberg, Viktor
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    REE-Enriched Mn-Oxide Precipitates in Water-Bearing Fractures in the Ytterby Mine, Sweden2016In: Mining Meets Water – Conflicts and Solutions: IMWA 2016 in Leipzig, Germany, July 11–15, 2016 / [ed] Drebenstedt, C. & Paul, M., Freiberg: TU Bergakademie Freiberg, Institute of Mining and Special Civil Engineering , 2016, p. 346-352Conference paper (Refereed)
    Abstract [en]

    The Ytterby mine, Sweden, is known for the discovery of eight elements, including yttrium and five of the rare earth elements (REE). The mine was in operation from 1750 to 1933 and was after closure used as a storage depot for fuel from the 1950s to 1995. A tunnel was opened in the 1950s through the bedrock into the mine to allow access to the storage depot. Recent water monitoring campaigns (20122015) in the mine revealed a black substance (denoted YBS) in some fractures opening into the tunnel. Analysis of the YBS (elemental analysis, phase analysis by XRD, SEM with energy dispersive X-ray spectrometry, IR-and EPR-spectroscopy, preferential leaching at pH 4) showed that the main mineral component of the YBS is the manganese oxide birnessite. Also minor quantities of other less well defined manganese oxides were found, as well as silicates (quartz grains, possibly feldspar grains) and calcite. Birnessite has typically the composition Mx(Mn3+, Mn(2)(4+))O(4)xAq, with M= Na, Ca and x= 0.5. The birnessite component in YBS had a Mn3+/Mn4+ ratio of 1.04/0.96 with M = 0.42 Ca + 0.03 (REE+Y), 0.03 Mg and 0.03 other metals. All of these metals were firmly associated with the structure, since no release was observed at pH 4, except for significant fractions of the total Na, Mg, Ca-contents. Thus, REE+Y correspond to 1% of the total YBS mass and up to 3% of the metal content in the birnessite phase. This corresponds to an REE enrichment factor of the order 106 (YBS-birnessite/ fracture water). Birnessite with a substantial fraction of REE in the lattice has not previously been reported. The formation of birnessite is a microbial process. Identification of the microorganisms present in the Ytterby system is in progress.

  • 1583.
    Sjöberg, Viktor
    Örebro University, School of Science and Technology.
    Utilization of waste materials for extraction of strategic metals: a biogeochemical approach2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Worldwide the modern society produces vast amounts of waste materials containing strategic and valuable metals. Some of them are of substantial economic or environmental significance if controlled recovery of metals can be performed or if uncontrolled release to the environment occurs.

    By cultivating Agrostis capillaris on historical sulfidic mine waste the leachate composition can be altered and its volume reduced. In combination with additives such as bark compost and water works granules the concentration of several hazardous metals decreased significantly already after eight weeks. Limited actions can therefore be used to decrease the environmental impact from such waste.

    Shale in general contains considerable amounts of strategic metals. If naturally occurring microorganisms are provided with a source of nutrients, increased mobilization of strategic metals can be obtained. By using wood chips as the nutrient source the mobilization of vanadium and uranium increased significantly. Highest mobilization efficiency was observed when the carbon source was put on top of the shale.

    Analysis of strategic metals is often performed by argon plasma techniques such as ICP-QMS. However, the use of argon increases the analytical costs. If isotopic information is not needed and slightly higher uncertainties can be accepted, several strategic metals can successfully be quantified by the nitrogen plasma based MP AES. The analytical cost can then be cut with more than 99%.

    List of papers
    1. Conditioning sulfidic mine waste for growth of Agrostis capillaris - impact on solution chemistry
    Open this publication in new window or tab >>Conditioning sulfidic mine waste for growth of Agrostis capillaris - impact on solution chemistry
    2014 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 21, no 11, p. 6888-6904Article in journal (Refereed) Published
    Abstract [en]

    Contamination of the environment due to mining and mineral processing is an urgent problem worldwide. It is often desirable to establish a grass cover on old mine waste since it significantly decreases the production of leachates. To obtain sustainable growth, it is often necessary to improve several properties of the waste such as water-holding capacity, nutrient status, and toxicity. This can be done by addition of organic materials such as wood residues, e. g., compost. In this study, we focus on the solution chemistry of the leachates when a substrate containing historic sulfidic mine waste mixed with 30 % (volume) bark compost is overgrown by Agrostis capillaris. The pot experiments also included other growth-promoting additives (alkaline material, mycorrhiza, and metabolizable carbon) to examine whether a more sustainable growth could be obtained. Significant changes in the plant growth and in the leachates composition were observed during 8 weeks of growth. It was concluded that in this time span, the growth of A. capillaris did not affect the composition of the leachates from the pots. Instead, the composition of the leachates was determined by interactions between the bark compost and the mine waste. Best growth of A. capillaris was obtained when alkaline material and mycorrhiza or metabolizable carbon was added to the substrate.

    Place, publisher, year, edition, pages
    Springer, 2014
    Keyword
    Agrostis capillaris, Mine waste, Bark compost, Leachate composition
    National Category
    Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:oru:diva-37809 (URN)10.1007/s11356-014-2600-x (DOI)000336371000012 ()2-s2.0-84901248901 (Scopus ID)
    Funder
    EU, FP7, Seventh Framework Programme, 226870
    Available from: 2014-10-17 Created: 2014-10-17 Last updated: 2017-12-05Bibliographically approved
    2. Impact of organic carbon on the leachability of vanadium, manganese, iron and molybdenum from shale residues
    Open this publication in new window or tab >>Impact of organic carbon on the leachability of vanadium, manganese, iron and molybdenum from shale residues
    2015 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 75, p. 100-109Article in journal (Refereed) Published
    Abstract [en]

    From 1942 to the 1966, oil was produced by pyrolysis of shale, in Kvarntorp, Sweden. This generated some 40 million m3 of metal rich pyrolyzed shale and discarded fines that were piled on site with its original metal content almost intact. The present study focuses on the leaching of vanadium, manganese, iron and molybdenum from fines after addition of wood chips and steel slag, in outdoor 1 m3 reactor systems at low liquid to solid ratio, in order to evaluate the potential environmental impact and recovery of the elements from the leachates. Seasonal variations were observed, with increased leaching during peak summer. For vanadium and molybdenum, high addition of wood chips decreased the leaching, probably due to adsorption. Manganese showed the opposite behavior while leaching of iron was almost independent of the amount of wood chips. Depending on the systems, up to 2200 μg L-1 vanadium, 90 μg L-1 molybdenum, 25 mg L-1 manganese and 500 mg L-1 iron was found in the aqueous phase. Applied to the 40 million m3 pile, the annual leaching of those elements may reach 14 ton, 0.6 ton, 200 ton and 2400 ton, respectively.

    Keyword
    Bioleaching; Environmental; Leaching; Pollution
    National Category
    Environmental Sciences
    Research subject
    Enviromental Science
    Identifiers
    urn:nbn:se:oru:diva-41168 (URN)10.1016/j.mineng.2014.10.018 (DOI)000353861300015 ()2-s2.0-84927124587 (Scopus ID)
    Note

    Funding Agency:

    Faculty of Economics, Science and Technology at Örebro University

    Available from: 2015-01-13 Created: 2015-01-13 Last updated: 2017-12-05Bibliographically approved
    3. Release of uranium from weathered black shale in meso-scale reactor systems: first year of data
    Open this publication in new window or tab >>Release of uranium from weathered black shale in meso-scale reactor systems: first year of data
    2014 (English)In: Uranium - Past and Future Challenges: Proceedings of the 7th International Conference on Uranium Mining and Hydrogeology / [ed] Merkel Broder J., Arab Alireza, Springer, 2014, p. 139-146Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    Springer, 2014
    National Category
    Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:oru:diva-37820 (URN)978-3-319-11059-2 (ISBN)
    Conference
    Uranium Mining and Hydrogeology 7, 2014, Freiberg, Germany
    Available from: 2014-10-17 Created: 2014-10-17 Last updated: 2017-10-18Bibliographically approved
    4. Comparison of MP AES and ICP-MS for analysis of principal and selected trace elements in nitric acid digests of sunflower (Helianthus annuus)
    Open this publication in new window or tab >>Comparison of MP AES and ICP-MS for analysis of principal and selected trace elements in nitric acid digests of sunflower (Helianthus annuus)
    2015 (English)In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 135, p. 124-132Article in journal (Refereed) Published
    Abstract [en]

    The use of nitrogen as plasma gas for microwave plasma atomic emission spectroscopy (MP AES) is an interesting development in analytical science since the running cost can be significantly reduced in comparison to the inductively coupled argon plasma. Here, we evaluate the performance of the Agilent 4100 MP AES instrument for the analysis of principal metals (Ca, K, Mg, and Na), lithogenic metals (Al, Fe, and Mn) and selected trace metals (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V, and Zn) in nitric acid plant digests. The digests were prepared by microwave-assisted dissolution of dry plant material from sunflower (Helianthus annuus) in concentrated nitric acid. Comparisons are made with analysis of the same solutions with ICP-MS (Agilent 7500cx) using the octopole reaction system (ORS) in the collision mode for As, Fe, and V.

    The limits of detection were usually in the low μg L-1 range and all principal and lithogenic metals were successfully determined with the MP AES and provided almost identical results with the ICP-MS. The same applies for the selected trace metals except for As, Co and Mo where the concentrations were below the detection limit with the MP AES. For successful analysis we recommend that (i) only atom lines are used, (ii) ionization is minimized (e.g. addition of CsNO3) and (iii) the use of internal standards should be considered to resolve spectral interferences.

    Keyword
    Digestion; ICP-MS; Macro and trace elements; MP AES
    National Category
    Chemical Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-41166 (URN)10.1016/j.talanta.2014.12.015 (DOI)000349730700018 ()25640135 (PubMedID)2-s2.0-84921468749 (Scopus ID)
    Note

    Funding Agencies:

    Faculty of Economics, Science and Technology at Örebro Universitet, Sweden

    Foundation for Polish Science, International PhD Projects Program

    EU European Regional Development Fund MPD/2009-3/5

    Available from: 2015-01-13 Created: 2015-01-13 Last updated: 2017-12-05Bibliographically approved
    5. Release of vanadium from LD-slag by exposure to ARD
    Open this publication in new window or tab >>Release of vanadium from LD-slag by exposure to ARD
    2010 (English)In: Mine water and innovative thinking: proceedings 2010 / [ed] Christian Wolkersdorfer, Antje Freund, Cape Breton University Press , 2010, p. 399-402Conference paper, Published paper (Refereed)
    Abstract [en]

    In abatement of acid rock drainage (ARD) slag from the Linz-Donawitz steel making process (LD-slag) provides high neutralizing capacity at low cost. A serious drawback for the use of this by-product is its high content of vanadium, which makes it a potential source of toxic vanadium species. The aim of this work was to determine the most common vanadium species, V(IV) and V(V), leached from LD-slag by artificial ARD. Capillary electrophoresis was employed to quantify the species. From the results an initial dominance of V(V) and increasing abundance of V(IV) with increasing artificial ARD L/s ratio was observed.

    Place, publisher, year, edition, pages
    Cape Breton University Press, 2010
    National Category
    Natural Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-24257 (URN)000323234800092 ()978-1-897009-47-5 (ISBN)
    Conference
    International Mine Water Association symposium: Mine Water and Innovative Thinking (IMWA), Sydney, Nova Scotia, Canada, Sep. 05-09, 2010
    Available from: 2012-08-06 Created: 2012-08-06 Last updated: 2017-10-18Bibliographically approved
    6. Potential use of native fungal strains for assisted uranium retention
    Open this publication in new window or tab >>Potential use of native fungal strains for assisted uranium retention
    Show others...
    2015 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 81, p. 173-178Article in journal (Refereed) Published
    Abstract [en]

    Uranium-stabilizing ligands can be useful complexing agents for uranium in aqueous solution. The discovery of novel ligand candidates for selective uranium capture in artificial and natural waters could provide scope for their use in water remediation and metal recovery from low- and high grade ores. In this study we used seven fungal strains, isolated from shale waste, to monitor the uranium retention capacity from an aqueous solution. After four weeks of incubation, suspensions containing the fungal strains were filtered, and up to 100% of the total uranium inventory was removed from a 10 mg L-1 solution. Approximately 70% of the total uranium removal is attributed to complexation and/or adsorption by particles in the malt extract and some 10% is adsorbed by the fungal biomass. The additional 20% uranium removed could be related to the excretion of fungal metabolites. From 58% to 90% of the uranium is removed within ten minutes. The formation of colloidal/particulate uranium is proposed to be controlled by organic ligands in the culture medium and organic ligands excreted by the fungi where phosphorus moieties seem to be important. Membrane fouling by the hydrocarbons is also suggested to contribute to a loss of uranium from the aqueous phase.

    Keyword
    Biotechnology; Environmental; Pollution; Wasteprocessing
    National Category
    Chemical Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-46072 (URN)10.1016/j.mineng.2015.04.003 (DOI)000361253100023 ()2-s2.0-84940440497 (Scopus ID)
    Note

    Funding Agencies:

    Academy of Economy, Science and Technology at Orebro University

    Foundation of Polish Science

    EU European Regional Development fund MPD/2009-3/5

    Available from: 2015-10-12 Created: 2015-10-12 Last updated: 2017-12-01Bibliographically approved
  • 1584.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Ekqvist, I.
    Hultman, C.
    Ingvarsson, J.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Uptake of metals in Pisum sativum grown on sulfidic shale residues2013In: / [ed] E. Kothe and G. Büchel, 2013Conference paper (Refereed)
  • 1585.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Grandin, Anna
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Re-adsorption of uranium from low grade shale to aspen wood during heterotrophic leaching2011In: Proceedings of the 10th symposium on remediation in Dornburg / [ed] E. Kothe and G. Büchel, 2011Conference paper (Refereed)
  • 1586.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Johansson, A.
    Nyåker, S.
    Thurfors, J.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Uptake of arsenic in Pisum sativum grown on arsenic contaminated soil2013In: / [ed] E. Kothe and G. Büchel, 2013Conference paper (Refereed)
  • 1587.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Determination of trace metal distribution in broad beans with ICP-ORS-QMS2015Conference paper (Other academic)
  • 1588.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Impact of organic carbon on the leachability of vanadium, manganese, iron and molybdenum from shale residues2015In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 75, p. 100-109Article in journal (Refereed)
    Abstract [en]

    From 1942 to the 1966, oil was produced by pyrolysis of shale, in Kvarntorp, Sweden. This generated some 40 million m3 of metal rich pyrolyzed shale and discarded fines that were piled on site with its original metal content almost intact. The present study focuses on the leaching of vanadium, manganese, iron and molybdenum from fines after addition of wood chips and steel slag, in outdoor 1 m3 reactor systems at low liquid to solid ratio, in order to evaluate the potential environmental impact and recovery of the elements from the leachates. Seasonal variations were observed, with increased leaching during peak summer. For vanadium and molybdenum, high addition of wood chips decreased the leaching, probably due to adsorption. Manganese showed the opposite behavior while leaching of iron was almost independent of the amount of wood chips. Depending on the systems, up to 2200 μg L-1 vanadium, 90 μg L-1 molybdenum, 25 mg L-1 manganese and 500 mg L-1 iron was found in the aqueous phase. Applied to the 40 million m3 pile, the annual leaching of those elements may reach 14 ton, 0.6 ton, 200 ton and 2400 ton, respectively.

  • 1589.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    LC-MP AES as a screening tool for metal-DOC interactions in ARD2017In: Bio-geo interactions: basic knowledge to application: 16th Symposium on remediation in Jena “Jenaer Sanierungskolloquium”. Conference proceedings, 2017, p. 43-43Conference paper (Other academic)
    Abstract [en]

    Dissolved organic carbon (DOC) such as humic and fulvic acids have a high ability to form stable complexes with many metal ions. Also otherwise insoluble elements may be mobilized by complexolysis. Detection of the humic substances can be made with size exclusion chromatography (SEC) with UV/Vis and fluorescence detection. To detect the metals that different organic compounds carry the metal content in the eluent can be analyzed. However, the phosphate buffer that is used in the reference method is not well suited since phosphate and hydrogen phosphate ions are excellent complexing agents for many metals. In this work ammonium nitrate buffer was evaluated and used.

    To decrease the analytical cost and streamline the analytical procedure an LC-system (Agilent 1260) was connected to an MP AES (Agilent 4200). After separation and spectroscopic measurements the eluent was lead to the nebulizer and the metal content in the eluent was determined as a function of time.

    When acidic shale residues come in contact with wood chips, acidic hydrolysis and microbial degradation generate a complex mixture of hydrophilic organic compounds and acid rock drainage (ARD). If no subsequent condensation occurs the released organics would mainly contain low molecular weight carbon compounds (LMWOC). The fluorescence at 443 nm after exitation at 345 nm reveals that compounds of humic and fulvic character are present in the leachates. The content of manganese in the more complex forms of organic compounds is limited and it is mainly associated with LMWOC. Hence, humic compounds are not a good carrier of manganese in this type of system.

    By using ammonium nitrate as buffer solution the separation was almost identical to the phosphate buffer. The results show that LC and MP AES can be used for analysis of the metal content as a function of size of organic carriers, such as humic substances and LMWOC. By using MP AES for metal analysis, operating cost is significantly decreased compared to hitherto used methods based on ICP. The results also indicate that substances with humic character form during acidic and microbial degradation of wood. From an environmental perspective this is of importance since several organic compounds facilitate metal mobilization.

  • 1590.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Mobilization of vanadium from alkaline LD-slag: first year of data2014In: / [ed] E. Kothe and G. Büchel, 2014Conference paper (Refereed)
  • 1591.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Overgrowth of alkaline LD-slag with Agrostis capillaris: impact on solution chemistry2014In: / [ed] E. Kothe and G. Büchel, 2014Conference paper (Refereed)
  • 1592.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Release of uranium from weathered black shale in meso-scale reactor systems: first year of data2014In: Uranium - Past and Future Challenges: Proceedings of the 7th International Conference on Uranium Mining and Hydrogeology / [ed] Merkel Broder J., Arab Alireza, Springer, 2014, p. 139-146Conference paper (Refereed)
  • 1593.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Revegetation of acidic mine waste: impact of commercial bark compost2012In: / [ed] E. Kothe and G. Büchel, 2012Conference paper (Refereed)
  • 1594.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Allard, Bert
    Örebro University, School of Science and Technology.
    Removal of vanadium from neutralized acid mine drainage (AMD) by adsorption to saw dust2012In: International Mine Water Association Symposium: Bunbury, Australia 2012 / [ed] McCullough C.D., Lund M.A., Wyse L., 2012, p. 727-734Conference paper (Refereed)
    Abstract [en]

    reatment of AMD with alkaline waste materials such as LD-slag may cause increased mobilization of potentially toxic metals, particularly those that form oxyanions. Vanadium is one of them and it can reach up to 3 % (weight) in the LD-slag. In this report a multivariate approach was used to study the removal of primarily vanadium from AMD neutralized with LD-slag by adsorption to wood. Two of the most important factors for the adsorption were pH and contact time. Some 90 % removal of vanadium was obtained after a contact time of 7 days when 25 g L-1 saw dust was added to AMD neutralized with LD-slag.

  • 1595.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Grandin, Anna
    Örebro University, School of Science and Technology.
    Impact of an Organic Carbon Source on the Leaching of Vanadium from LD-Slag2012In: 9th International Conference on Acid Rock Drainage,ICARD 2012, Ottawa, Canada, 20-26 May 2012: Volume 1 of 2, 2012, p. -700Conference paper (Refereed)
  • 1596.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Grandin, Anna
    Örebro University, School of Science and Technology.
    Allard, Bert
    Örebro University, School of Science and Technology.
    Conditioning sulfidic mine waste for growth of Agrostis capillaris - impact on solution chemistry2014In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 21, no 11, p. 6888-6904Article in journal (Refereed)
    Abstract [en]

    Contamination of the environment due to mining and mineral processing is an urgent problem worldwide. It is often desirable to establish a grass cover on old mine waste since it significantly decreases the production of leachates. To obtain sustainable growth, it is often necessary to improve several properties of the waste such as water-holding capacity, nutrient status, and toxicity. This can be done by addition of organic materials such as wood residues, e. g., compost. In this study, we focus on the solution chemistry of the leachates when a substrate containing historic sulfidic mine waste mixed with 30 % (volume) bark compost is overgrown by Agrostis capillaris. The pot experiments also included other growth-promoting additives (alkaline material, mycorrhiza, and metabolizable carbon) to examine whether a more sustainable growth could be obtained. Significant changes in the plant growth and in the leachates composition were observed during 8 weeks of growth. It was concluded that in this time span, the growth of A. capillaris did not affect the composition of the leachates from the pots. Instead, the composition of the leachates was determined by interactions between the bark compost and the mine waste. Best growth of A. capillaris was obtained when alkaline material and mycorrhiza or metabolizable carbon was added to the substrate.

  • 1597.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Grandin, Anna
    Örebro University, School of Science and Technology.
    Allard, Bert
    Örebro University, School of Science and Technology.
    Vegetation of historical mine waste from the Ljusnarsberg deposit with Agrostis capillaris: impact on leaching of copper2013In: Reliable mine water technology. Proceedings of the International Mine Water Association Annual Conference 2013, Golden, Colorado, USA, August 6-9, 2013, 2013, p. 1119-1124Conference paper (Refereed)
    Abstract [en]

    In Sweden there are hundreds of sites that need to be remediated due to high release of metals such as Cu. In order to minimize costs the methods should involve cheap materials and technical solutions. This study focuses on the possibility to establish Agrostis capillaris on sulfidic mine waste, after mixing with 30 % bark compost, and the subsequent release of Cu. Ini- tially the substrate produced leachates with pH 3.5 containing approximately 1 mg/L Cu. After 4 months the pH had increased to 4.5 and up to 80 % of the Cu was retained     

  • 1598.
    Sjöberg, Viktor
    et al.
    Örebro University, School of Science and Technology.
    Keiter, Steffen
    Örebro University, School of Science and Technology.
    Karlsson, Stefan
    Örebro University, School of Science and Technology.
    Metal toxicity: Are we measuring what we want?2015Conference paper (Other academic)
  • 1599.
    Sjödahl, Anna
    Örebro University, School of Science and Technology.
    Lärares användning av digitala spel i matematikundervisningen2016Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Swedish school becomes increasingly digitized and that causes a need for further research on the subject. One aspect that so far has received little attention is the teacher's role. This case study is therefor based on three interviewed teachers’ stories telling how they use digital games in the mathematics education. The purpose of the study is that by studying how the teachers’ competence can appear, give inspiration for other teachers to use digital games in their teaching.Two perspectives have been adopted to detect their competencies in the field. One point of view has been the games and how they are used. The other point of view has been the education and how it has been influenced. Results show that a large part of the usage is pure routine exercises, but the teachers can also find ways to take education one step further and thus justifies the use of digital games in their practice.

  • 1600.
    Sjödahl, Anna
    Örebro University, School of Science and Technology.
    Spela för kunskap: Digitala spels effekter i matematikundervisningen2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This review contains two parts; a summary of what can be said about the effects on students learning and attitudes towards mathematics when digital games are used in education; and an analysis of which potential digital games has in a socio cultural classroom. The results show that it is no absolute consensus among the researchers but a trend saying that digital games can have a positive effect on both students learning and attitudes towards mathematics. The findings show some research done about what features in the games that are beneficial for the learning process, but further research is needed. Furthermore, the digital games show potential in several aspects from a socio cultural perspective. Those findings will be further discussed in the paper.

29303132333435 1551 - 1600 of 1837
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf