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  • 301.
    Boubitsas, Dimitrios
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Tang, Luping
    Chalmers University of Technology, Sweden.
    An approach for measurement of chloride threshold values2013In: International Journal of Structural Engineering, ISSN 1758-7328, Vol. 4, no 1-2, p. 24-34Article in journal (Refereed)
    Abstract [en]

    Chloride induced corrosion is one of the major causes for degradation of reinforced concrete structures. One of the most important factors in this process is the critical chloride content (chloride threshold value) in the vicinity of the reinforcement that causes initiation of corrosion. In this work the development of a practice-related approach that includes specimen shape, preconditioning, corrosion measurement techniques, and calculation concepts, for determining the critical chloride content are presented. The results in this study showed that the presented approach for determining chloride threshold values functioned fairly well, and suggestions for further improvement are proposed.

  • 302.
    Boubitsas, Dimitrios
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB. Lund University, Sweden.
    Tang, Luping
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB. Chalmers University of Technology, Sweden.
    The influence of reinforcement steel surface condition on initiation of chloride induced corrosion2015In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 48, no 8, p. 2641-2658Article in journal (Refereed)
    Abstract [en]

    This paper describes a part of the work in the development of a "standard" test method for determining chloride threshold values required to initiate corrosion on reinforcement in concrete. The prerequisites of the test set-up are that the test conditions should be reasonably comparable to those in service and the test method should be fairly reproducible and as rapid as possible concerning the slow diffusion nature of the investigated phenomenon. This paper presents the results from a study on the influence of steel bar surface condition on chloride induced corrosion. Various electrochemical techniques were employed in the study to monitor the corrosion behaviour of the embedded bars with three different surface conditions. It is shown that the steel surface condition has a strong effect on the corrosion initiation of reinforcement in concrete, and can likely be the most decisive parameter attributing to the variability in the reported chloride threshold values.

  • 303.
    Bougas, Kostas
    et al.
    Malmö University, Sweden.
    Jimbo, Ryo Y. U.
    Malmö University, Sweden.
    Vandeweghe, Stefan
    Malmö University, Sweden; University of Ghent, Belgium.
    Hayashi, Mariko
    Malmö University, Sweden.
    Bryington, Matthew S.
    Malmö University, Sweden; Ohio State University, USA.
    Kozai, Yusuke
    Kanagawa Dental College, Japan.
    Schwartz-Filho, Humberto Osvaldo
    Sao Paulo State University, Brazil.
    Tovar, Nick M.
    New York University, USA.
    Adolfsson, Erik
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Ono, Daisuke
    Nagasaki University, Japan.
    Coelho, Paulo Guilherme
    New York University, USA.
    Wennerberg, Ann
    Malmö University, Sweden.
    Bone apposition to laminin-1 coated implants: Histologic and 3D evaluation2013In: International Journal of Oral and Maxillofacial Surgery, ISSN 0901-5027, E-ISSN 1399-0020, Vol. 42, no 5, p. 677-682Article in journal (Refereed)
    Abstract [en]

    Laminin-1 has been reported as one of the factors responsible for the nucleation of calcium phosphates and, in vitro, has been reported to selectively recruit osteoprogenitors. This article focused on its in vivo effects, and evaluated the effect of laminin-1 local application on osseointegration. Polished cylindrical hydroxyapatite implants were coated with laminin-1 (test) and the bone responses in the rabbit tibiae after 2 and 4 weeks were evaluated and compared to the non-coated implants (control). Before the samples were processed for histological sectioning, they were three-dimensionally analysed with micro computed tomography (μCT). Both evaluation methods were analysed with regards to bone area around the implant and bone to implant contact. From the histologic observation, new bone formation around the laminin-1 coated implant at 2 weeks seemed to have increased the amount of supporting bone around the implant, however, at 4 weeks, the two groups presented no notable differences. The two-dimensional and three-dimensional morphometric evaluation revealed that both histologic and three-dimensional analysis showed some tendency in favour of the test group implants, however there was no statistical significance between the test and control group results.

  • 304. Bradley, E. L.
    et al.
    Honkalampi-Hämäläinen, U.
    Weber, A.
    Andersson, M. A.
    Bertaud, F.
    Castle, L.
    Dahlman, O.
    RISE, STFI-Packforsk.
    Hakulinen, P.
    Hoornstra, D.
    Lhuguenot, J. -C
    Mäki-Paakkanen, J.
    Salkinoja-Salonen, M.
    Speck, D. R.
    Severin, I.
    Stammati, A.
    Turco, L.
    Zucco, F.
    von Wright, A.
    The BIOSAFEPAPER project for in vitro toxicity assessments: Preparation, detailed chemical characterisation and testing of extracts from paper and board samples2008In: Food and Chemical Toxicology, ISSN 0278-6915, E-ISSN 1873-6351, Vol. 46, no 7, p. 2498-2509Article in journal (Refereed)
    Abstract [en]

    Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-food contact board showed the greatest number and highest concentrations of GC-MS detectable compounds. The extracts were subjected to a battery of in vitro toxicity tests measuring both acute and sublethal cytotoxicity and genotoxic effects. None of the water or Tenax extracts was positive in cytotoxicity or genotoxicity assays. The ethanol extract of the non-food contact board gave a positive response in the genotoxicity assays, and all four ethanol extracts gave positive response(s) in the cytotoxicity assays to some extent. These responses could not be pinpointed to any specific compound, although there appeared a correlation between the total amount of extractables and toxicity.

  • 305.
    Brander, Linus
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Hydrasplit: ett avslutat EU-projekt2014In: Svensk Bergs & Brukstidning, ISSN 0039-6435, Vol. 93, no 5-6Article in journal (Other academic)
  • 306.
    Brander, Linus
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Kristallografin i geologin2014In: Kemivärlden Biotech med Kemisk Tidskrift, ISSN 1650-0725, no 11, p. 20-22Article in journal (Other academic)
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  • 307.
    Brander, Linus
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Tid för ett kvartssamtal2013In: Svensk Bergs & Brukstidning, ISSN 0039-6435, Vol. 92, no 2Article in journal (Other academic)
  • 308.
    Brander, Linus
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Schouenborg, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Kompetenscentrum för byggande av och i berg2013In: Svensk Bergs & Brukstidning, ISSN 0039-6435, Vol. 92, no 1Article in journal (Other academic)
  • 309.
    Bratberg, Johan
    et al.
    Thermo-Calc Software AB.
    Ågren, J.
    Royal Institute of Technology.
    Frisk, Karin
    RISE, Swerea, Swerea KIMAB.
    Diffusion simulations of MC and M7C3 carbide coarsening in bcc and fee matrix utilising new thermodynamic and kinetic description2008In: Materials Science and Technology, ISSN 0267-0836, E-ISSN 1743-2847, Vol. 24, no 6, p. 695-704Article in journal (Refereed)
    Abstract [en]

    A new thermodynamic database has been combined with an existing kinetic database to perform coarsening simulations in ternary systems including MC and M7C3 carbides in an fee matrix. The kinetic database was revised taking into consideration the new experimental information on the Fe-Cr-V-C system obtained in the present work, and available experiments on the ternary Fe-Cr-C and Fe-V-C systems. After revision the agreement between experimental results and simulations was satisfactory. It was found that the interfacial energy of M7C3 was twice as large as that of the MC carbide. The calculations for commercial steels with 6 alloy elements gave results in satisfactory agreement with new experimental measurements. The present coarsening simulations use the calculated equilibrium state and the observed particle sizes as the state for the start of the simulations. All the simulations were performed with the DICTRA software. © 2008 Institute of Materials, Minerals and Mining.

  • 310. Brelid, H.
    et al.
    Bogren, J.
    Dang, B.
    Lundqvist, F.
    RISE, Innventia.
    Saltberg, A.
    Theliander, H.
    Kraft delignification: Recent findings regarding the impact of non-reacting ions in the cooking liquor2011Conference paper (Refereed)
  • 311.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Amen, Rafael
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Adolfsson, Erik
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Tegehall, Per-Erik
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Johander, Per
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Andersson, Dag
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Thermo-mechanical simulations and measurements on high temperature interconnections2011In: 12th Int. Conf. on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011, 2011, article id 5765772Conference paper (Refereed)
    Abstract [en]

    In order to place sensors or electronics in very high temperature environments, new materials and methods for interconnection are required. A comparative study between different electrical interconnection methods for very high operation temperatures (500 °C - 800 °C) is presented. Thermo-mechanical simulations and characterization of samples of the interconnection types during high temperature exposure are presented. The results of the thermo-mechanical simulations showed that stresses are low in a connection system based on liquid interconnection. This system, however, proved to be difficult to realize due to problems with oxides and sealing of the metallic liquid. Modeling of an interconnection based purely on mechanical pressure without any solder or metallic bond showed high stress. This was also confirmed during high temperature exposure where the connection failed. High stress was also predicted for an interconnection based on nano-Ag paste. The high temperature tests, however, showed promising results at 800 °C for over 100 hours. © 2011 IEEE.

  • 312.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Edwards, Michael
    Chalmers University of Technology, Sweden.
    Ottosson, Jonas
    Volvo Group Truck Technology, Sweden.
    Neumaier, Klaus
    Fairchild Semiconductor GmbH, Germany.
    Zschieschang, Olaf
    Fairchild Semiconductor GmbH, Germany.
    Otto, Alexander
    Fraunhofer ENAS, Germany.
    Kaulfersch, Eberhard
    Berliner Nanotest und Design GmbH, Germany.
    Andersson, Dag
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Thermo-mechanical simulations of SiC power modules with single and double sided cooling2015In: 2015 16th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, Institute of Electrical and Electronics Engineers Inc. , 2015, article id 7103136Conference paper (Refereed)
    Abstract [en]

    Effectively removing dissipated heat from the switching devices enables a higher current carrying capability per chip area ratio, thus leading to smaller or fewer devices for a given power requirement specification. Further, the use of SiC based devices has proven to increase the efficiency of the system thereby reducing the dissipated heat. Thermal models have been used to compare SiC power modules. Single and double sided cooling have been simulated. The simulated maximum temperatures were 141 °C for the single sided version and 119.7 °C for the double sided version. In addition, the reliability of a single sided module and thermally induced plastic strains of a double sided module have been investigated. A local model of the wire bond interface to the transistor metallization shows a 3‰ maximum increase in plastic strain during the power cycle. Simulations of the creep strain rates in the die attach solder layer for a power cycling loads also shows a 3‰ increase in creep strain per cycle.

  • 313.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Enoksson, P.
    Chalmers University of Technology.
    Wieser, M.
    Swedish Institute of Space Physics.
    Barabash, S.
    Swedish Institute of Space Physics.
    Emanuelsson, M.
    Swedish Institute of Space Physics.
    Microshutters for MEMS-based time-of-flight measurements in space2011In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), 2011, p. 597-600Conference paper (Refereed)
    Abstract [en]

    This paper reports on the fabrication, integration and first operation of a mechanical microshutter in a time-of-flight (TOF) based ion detector in space. The microshutter is fabricated from a silicon on insulator (SOI) wafer and operated in a resonance mode, 306 kHz. Open time of the shutter is 100 ns. The microshutters are integrated in the PRIMA instrument, which is part of the payload on the Swedish PRISMA mission. PRISMA was successfully launched into low Earth orbit on June 15, 2010.

  • 314.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Formánek, J.
    Czech Technical University.
    Laposa, A.
    Czech Technical University.
    Jakovenko, J.
    Czech Technical University.
    Adolfsson, Erik
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Johander, Per
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Simulations of a high temperature pressure sensor packaging and interconnection2012In: EuroSimE 2012: 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, 2012Conference paper (Refereed)
    Abstract [en]

    Modeling and thermal cycling of a high temperature pressure sensor packaging is presented. The packaging is based on the green-state milling of alumina to the desired geometry and conduits for the electrical conductors, followed by sintering of the ceramics with the electrical conductors inside. The electrical interconnections are based on silver. For short term operation, the package can be exposed to temperatures close to the melting temperature of silver (961°C). It has shown operational in temperature cycling above 600°C for more than 1800 hours. Modeling of the package show that the stress in the electrical interconnections are close to the yield stress of silver at 20°C. The stress free temperature in the modeling was set to 850°C. Temperature induced stress and strains in the packaging and a fatigue simulation are performed. The package is generic and can be converted to fit most geometries and high temperature applications. © 2012 IEEE.

  • 315.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Neumaier, Klaus
    Fairchild Semiconductor GmbH, Germany.
    Mann, Alexander
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Zschieschang, Olaf
    Fairchild Semiconductor GmbH, Germany.
    Otto, Alexander
    Fraunhofer ENAS, Germany.
    Kaulfersch, Eberhard
    Berhner Nanotest und DesIgn GmbH, Germany.
    Edwards, Michael
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Andersson, Dag
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Modeling of SiC power modules with double sided cooling2014In: 2014 15th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2014, IEEE Computer Society , 2014, article id 6813864Conference paper (Refereed)
    Abstract [en]

    Silicon Carbide (SiC) based transistor devices have demonstrated higher efficiency switching operation compared to silicon-based, state-of-the-art solutions due to the superior electrical and thermal properties of the SiC material. The improved current density and thermal conductivity allows SiC-based power modules to be smaller than their silicon counterparts for comparable current densities. The active chip area can be reduced further by effectively cooling the devices. In this work, a new power module including SiC bipolar junction transistors (BJT) and diodes and integrated double sided cooling will be introduced. The target application of these modules is a new drive-train system for commercial electric vehicles.

  • 316.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Åklint, Thorbjörn
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Neumaier, Klaus
    Fairchild Semiconductor GmbH, Germany.
    Zschieschang, Olaf
    Fairchild Semiconductor GmbH, Germany.
    Edwards, Michael
    Chalmers University of Technology, Sweden.
    Andersson, Dag
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Model verification of heat exchangers in a flow test rig2015In: 2015 16th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, Institute of Electrical and Electronics Engineers Inc. , 2015, article id 7103135Conference paper (Refereed)
    Abstract [en]

    In power electronics, more efficient removal of heat from the junction of power devices leads to a higher power rating per die, which in turn leads to fewer die and reduced system volume. Since temperature is a main driver in expected failure modes an increase in cooling capability can also enhance margins of the device reliability. Previously, CFD simulations of two novel heat exchanger designs that will be used in a power module with double sided cooling have been reported on. The heat exchangers are fabricated by direct 3D manufacturing of copper structures, which allows almost complete freedom in geometric design. Two novel geometries of heat exchanger cooling structures have previously been modeled in terms of thermal performance and expected pressure drop. A flow rig has been designed and calibrated to measure thermal performance and pressure drops of these heat sinks. For calibration purposes, measurements of the thermal response of wave structured and unstructured heat sinks are reported here. The results show that, as expected, the heat sink temperatures are lower for all flow rates in the wavestructured geometry. A thermal CFO model accurately predicts the behavior of the temperature difference between inlet and outlet versus flow rate, but predicts higher absolute temperature values. It was also found that the model underestimates the pressure drop over the tested heat sillies. The pressure drop across a novel pine cone geometry heat sink fabricated by additive manufacturing methods was also measured. Comparisons to a reduced model, which neglects everything before the inlet and after the outlet of the tested device, showed that the behavior of this pine structured heat sink was not predicted correctly. The pressure drop increased more rapidly with flow rates in the model than in the measurements. The main source of error in the measurements and simulations comes from a lack of thermal loading. Future work to improve the flow rig includes possibilities to increase the temperature loading at the bottom of the heat sink under test.

  • 317.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Åklint, Thorbjörn
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Sandberg, Chet
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Johander, Per
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Andersson, Dag
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    High temperature packaging for SiC power transistors2012In: Proceedings - 2012 45th International Symposium on Microelectronics, IMAPS 2012, 2012, p. 1124-1130Conference paper (Refereed)
    Abstract [en]

    Power transistors based on silicon carbide (SiC) are now commercially available. They have a higher efficiency and higher voltage blocking capabilities than conventional silicon devices. The wide-band gap and chemical inertness of SiC makes it suitable to high temperature operation. However, there is a need for new packaging for power transistors that can operate in higher temperatures. We have developed a package based on ceramics and silver for high temperature operation of SiC power transistors. Three types of SiC devices from different manufacturers are packaged and tested in room temperature. Though the devices were still functional after the packaging process, their performance seem to have degraded. This could be a result of the high temperature packaging process and the measurement setup. FEM simulations are also performed to investigate the thermo-mechanical behavior of the package. The target operating temperature of the package is 400°C. Modeling show stress concentrations at the corners of the device chip and suggests that this stress is decreased if the substrate metallization is changed from copper to silver.

  • 318.
    Brodin, Fredrik Wernersson
    et al.
    Chalmers University of Technology, Sweden.
    Sonavane, Yogesh
    Aalto University, Finland.
    Sedin, Maria
    RISE, Innventia.
    Displacement washing of TEMPO-oxidized softwood kraft pulp: Effects of change in fiber properties2013In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, no 3, p. 366-376Article in journal (Refereed)
    Abstract [en]

    Bleached softwood kraft pulp fibers were treated using TEMPO oxidation at two different dosages of NaClO. A batch of non-oxidized reference pulp was also prepared with a concentration of the tracer (Na) similar to the oxidized batches. A total of 15 washing experiments were conducted and the dispersion model was used to characterize washing behavior. TEMPO oxidation resulted in a major increase in the amount of carboxylate groups in the pulps and a considerable decrease in fiber/particle size in relation to the reference pulp fibers. Oxidized fibers also had less fiber curl than reference fibers. Water retention values were greater in the oxidized pulps and the oxidized fibers exhibited major swelling during the washing operation, while reference fibers had only minorswelling. The amount of sodium in the filter cakes after washing corresponded to the amount of carboxylate groups in the pulps. Swelling of oxidized pulp fibers needs to be considered in order to describe filtration and washing. The average specific filtration resistance for all pulps in this study was in the order of 1010-1011 m/kg, i.e. moderately easy to filter. The most oxidized pulp had the highest average specific filtration resistance and the lowest value for the estimated effective longitudinal dispersion coefficient, in agreement with theory.

  • 319.
    Brodin, Ida
    et al.
    RISE, Innventia.
    Ernstsson, Marie
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Gellerstedt, Göran
    RISE, Innventia.
    Sjöholm, Elisabeth
    RISE, Innventia.
    Oxidative stabilisation of kraft lignin for carbon fibre production2012In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, no 2, p. 141-147Article in journal (Refereed)
    Abstract [en]

    With the aim of investigating kraft lignin as a raw material for carbon fibre production, different lignins have been stabilised in air at conditions varied according to a full factorial experimental design. The lignins under examination were purified kraft lignin powders originating from birch, spruce/pine and Eucalyptus globules, as well as lignin fibres originating from birch with 5 poly(ethylene oxide) (PEO) added as a plasticiser. The influence of temperature, time and heating rate on yield and glass-transition temperature (Tg) was investigated. The highest yield was achieved after stabilisation at 280°C during 2h with a heating rate of 0.2°C min -1. The Tg of all lignin powders was increased when stabilisation occurred under harsher conditions. X-ray photoelectron spectroscopy analysis (XPS) of both the outer surface and the cleaved cross-section of individual lignin/PEO fibres showed a clear gradient in the degree of chemical modification, with the major change occurring on the surface resulting in the appearance of a skin-core structure after stabilisation. The behaviour of the lignin fibres during stabilisation is similar to that of pitch-based fibres, indicating good possibilities for lignin as raw material for carbon fibre production.

  • 320. Brodin, Ida
    et al.
    Sjöholm, Elisabeth
    RISE, STFI-Packforsk.
    Gellerstedt, Göran
    RISE, STFI-Packforsk.
    Kraft lignin as feedstock for chemical products: The effects of membrane filtration2009In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 63, no 3, p. 290-297Article in journal (Refereed)
    Abstract [en]

    The use of technical lignins as feedstock for chemical products will require improvements in purity, molecular mass distribution, and thermal behavior. Therefore, industrial black liquors from kraft pulping of softwood (spruce/pine) and hardwood (birch and Eucalyptus globulus) have been subjected to fractionation according to molecular mass by ceramic membranes. After acidification and isolation of the lignin fractions, a variety of analytical methods have been applied to help understand their structure - property relationships. From all types of lignin, the chemical and polymeric properties of fractions isolated from the membrane permeates were more homogeneous. This demonstrates that technical kraft lignins, irrespective of origin, may constitute an interesting feedstock for products, such as carbon fibers, adhesives, and phenol-based polymers.

  • 321.
    Brodin, Ida
    et al.
    KTH Royal Institute of Technology, Sweden.
    Sjöholm, Elisabeth
    RISE, Innventia.
    Gellerstedt, Göran
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    The behavior of kraft lignin during thermal treatment2010In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 87, no 1, p. 70-77Article in journal (Refereed)
    Abstract [en]

    Purified kraft lignin fractions from technical pulping liquors of softwood and hardwood have been subjected to step-wise analytical pyrolysis in the temperature interval 200-900 °C. The heterogenic structure of kraft lignin was revealed by the formation of pyrolysis products throughout the entire temperature interval although the majority of products were formed at 500-600 °C. Beyond 700 °C, no further pyrolysis products could be detected but a substantial portion of the lignin was shown to be converted into thermally stable products (char) not accessible by analytical pyrolysis. With pre-oxidation of the lignin with air at 250 °C prior to pyrolysis, a shift towards higher pyrolysis temperature was observed with a concomitant change in product composition. Thermal gravimetric analysis on such lignins also showed an improved stability against degradation. Methylation of the lignin prior to pyrolysis did not induce any significant changes in behavior, except for much lower Tg values.

  • 322.
    Brodin, Malin
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Vallejos, Maria
    Instituto de Materiales de Misiones (IMAM), Argentina.
    Opedal, Mihaela Tanase
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Area, Maria C.
    Instituto de Materiales de Misiones (IMAM), Argentina.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Lignocellulosics as sustainable resources for production of bioplastics: a review2017In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 162, p. 646-664Article, review/survey (Refereed)
    Abstract [en]

    The bio-based economy requires a sustainable utilization of bioresources for production of a range of products, including pulp, paper, chemicals, biofuel and bioplastics. Currently, various types of bioplastics are produced industrially, competing in performance and price with the conventional fossil-oil based plastics. However, there is also a major interest in utilizing non-food crops, such as lignocellulosics, for production of drop-in polymers or new dedicated bioplastics. Lignocellulosic resources have a potential to replace plastics and materials, which have been traditionally based on fossil resources. This is important, as the development of high performance bio-based and renewable materials is one important factor for sustainable growth of the bio-based industry. However, production of bioplastics from forestry biomass requires a dedicated fractionation into the major components, i.e. cellulose, hemicelluloses and lignin, effective purification processes and cost-effective routes for conversion into monomers and platform molecules, utilized as a basis for bioplastics production. These processes are now technologically demanding and not profitable. The intention of this work was thus to review the current advances that have been made during the years within fractionation and purification of lignocelluloses and the processes that may feasible for production of bioplastics, based on wood components.

  • 323.
    Brooke, Robert
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Borras, M.
    LEITAT Technological Center, Spain.
    Belaineh Yilma, Dagmawi
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Edberg, Jesper
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Martinez-Crespiera, S.
    LEITAT Technological Center, Spain.
    Aulin, Christian
    RISE Research Institutes of Sweden, Bioeconomy and Health.
    Beni, Valerio
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Nanocellulose based carbon ink and its application in electrochromic displays and supercapacitors2021In: Flexible and Printed Electronics, ISSN 2058-8585, Vol. 6, no 4, article id 045011Article in journal (Refereed)
    Abstract [en]

    Conventional electronics have been highlighted as a very unsustainable technology; hazardous wastes are produced both during their manufacturing but also, due to their limited recyclability, during their end of life cycle (e.g. disposal in landfill). In recent years additive manufacturing processes (i.e. screen printing) have attracted significant interest as a more sustainable approach to electronic manufacturing (printed electronics). Despite the field of printed electronics addressing some of the issues related to the manufacturing of electronics, many components and inks are still considered hazardous to the environment and are difficult to recycle. Here we present the development of a low environmental impact carbon ink based on a non-hazardous solvent and a cellulosic matrix (nanocellulose) and its implementation in electrochromic displays (ECDs) and supercapacitors. As part of the reported work, a different protocol for mixing carbon and cellulose nanofibrils (rotation mixing and high shear force mixing), nanocellulose of different grades and different carbon: nanocellulose ratios were investigated and optimized. The rheology profiles of the different inks showed good shear thinning properties, demonstrating their suitability for screen-printing technology. The printability of the developed inks was excellent and in line with those of reference commercial carbon inks. Despite the lower electrical conductivity (400 S m-1 for the developed carbon ink compared to 1000 S m-1 for the commercial inks), which may be explained by their difference in composition (carbon content, density and carbon derived nature) compared to the commercial carbon, the developed ink functioned adequately as the counter electrode in all screen-printed ECDs and even allowed for improved supercapacitors compared to those utilizing commercial carbon inks. In this sense, the supercapacitors incorporating the developed carbon ink in the current collector layer had an average capacitance = 97.4 mF cm-2 compared to the commercial carbon ink average capacitance = 61.6 mF cm-2. The ink development reported herein provides a step towards more sustainable printed green electronics. © 2021 The Author(s).

  • 324.
    Brämming, Mats
    et al.
    SSAB EMEA.
    Millman, S.
    Tata Steel Research.
    Overbosch, A.
    Tata Steel Research.
    Kapilashrami, A.
    SSAB EMEA.
    Malmberg, Donald
    RISE, Swerea, Swerea MEFOS.
    Björkman, B.
    Luleå University of Technology.
    BOS vessel vibration measurement for foam level detection2011In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 51, no 1, p. 71-79Article in journal (Refereed)
    Abstract [en]

    In the BOS process liquid slag together with dispersed metal droplets, solid particles and process gases form an expanding foam. Certain process conditions may lead to excessive foam growth, forcing foam out through the vessel mouth, an event commonly known as 'slopping'. Slopping results in loss of valuable metal, equipment damage and lost production time. In the early 1980s a system for foam level and slopping control was installed at SSAB's steel plant in Luleå, a system based on the correlation between BOS vessel vibration in a narrow low frequency band and foam development. The technique, in this case with an accelerometer mounted on the trunnion bearing housing, soon showed its usefulness, for example when adapting existing lance patterns to a change in oxygen lance design from a 3-hole to a 4-hole nozzle. Estimating the actual foam height in the BOS vessel was of great importance in the recently completed RFCS funded research project "IMPHOS" (Improving Phosphorus Refining). Based on the earlier positive experiences, it was decided to further develop the vessel vibration measurement technique. Trials on an industrial size BOS vessel type LD/LBE have been carried out, this time with a tri-axial accelerometer mounted on the vessel trunnion. FFT spectrum analysis has been used in order to find the frequency band with best correlation to the foam level development. The results show that there is a correlation between vessel vibration and foam height that can be used for dynamic foam level and slopping control. © 2011 ISIJ.

  • 325.
    Brämming, Mats
    et al.
    SSAB EMEA, Sweden.
    Parker, G.
    Tata Steel Europe - Long Products, UK.
    Millman, S.
    Tata Research, UK.
    Kapilashrami, A.
    Tata Research, UK.
    Malmberg, Donald
    RISE - Research Institutes of Sweden, Materials and Production, Swerea MEFOS.
    Björkman, B.
    Luleå University of Technology, Sweden.
    Comparison between vessel vibration and audiometry for slopping control in the top-blown BOS process2011In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 82, no 6, p. 683-692Article in journal (Refereed)
    Abstract [en]

    Excess slag foam growth is a frequent problem in the BOS process. In the worst case, foam is forced out of the vessel and this phenomenon, commonly called slopping, not only results in loss of valuable metal yield but also in equipment damage and lost production time. In order to minimize slopping, accurate estimation of the foam level inside the vessel is an important part of BOS process control. In the top blown BOS vessel, slopping control is achieved using both static and dynamic measures. The most common implemented technique for dynamic foam height estimation and slopping control is the audiometer system. An alternative method, vessel vibration monitoring, has been investigated as part of the work in a RFCS funded research project called IMPHOS. In order to judge the usefulness of this method, parallel vibration and audio measurements have been carried out on 130 tonne as well as on 300 tonne BOS vessels. The results show that during stable process conditions there is good agreement between the two methods with regard to foam height estimation and, as vessel vibration and audiometry are largely independent of each other, a combination of the two is likely to increase significantly the accuracy of slopping prediction. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • 326.
    Brämming, Mats
    et al.
    LKAB.
    Wikström, Jan-Olov
    MEFOS − Metallurgical Research Institute AB.
    A blast furnace view on slags2002In: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 31, no 2, p. 88-99Article in journal (Refereed)
    Abstract [en]

    In 1982, SSAB, Luleå Works, converted the blast furnace ferrous burden from an acid to an olivine pellet with a high Fe content. This change made it possible to gradually reduce the slag volume to 150 kg per metric ton of hot metal with huge positive effects on the blast furnace operation. SSAB, Oxelösund Works, can present a similar development, initially by increasing the Fe content in sinter and later by converting to a 100% olivine pellet operation in 1995. In addition to a description of the historical development of the properties of SSAB blast furnace slags, this paper describes the technical means and issues as well as the environmental constraints governing future developments of slag volume and chemistry, including effects of changes in burden quality and possible tuyere injection of slag formers. © Blackwell Munksgaard, 2002.

  • 327.
    Brännvall, Elisabet
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    The limits of delignification in kraft cooking2017In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 12, no 1, p. 2081-2107Article in journal (Refereed)
    Abstract [en]

    The perspective of the article is to explore kraft cooking at the limits of delignification, i.e. what degree of delignification is needed to obtain fibre liberation and what is the maximum degree of delignification possible in the kraft pulping stage. The reasons for the quite narrow boundaries for sufficient and maximum delignification are explained, and the differences between the behaviour of hardwood and softwood kraft pulping are clarified.

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  • 328.
    Brännvall, Elisabet
    et al.
    RISE Research Institutes of Sweden.
    Aulin, Christian
    RISE Research Institutes of Sweden.
    CNFs from softwood pulp fibers containing hemicellulose and lignin2022In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed)
    Abstract [en]

    The energy demand to produce cellulose nanofibrils, CNFs, is high and additionally the cost of the starting material, the pulp, is substantial as high purity cellulose dissolving pulp is generally used. Pulps aimed for board and paper are produced at higher yield as they contain hemicelluloses and, in the case of unbleached pulp, lignin, and would be a more economical starting material for CNFs. It is of interest to understand how the presence of hemicellulose and lignin affects the fibrillation process and CNF properties. Kraft cooks of softwood were performed as well as kraft cooks with addition of polysulfide to increase the hemicellulose content. Part of the pulps were bleached to remove residual lignin, thus making it possible to compare pulps with and without lignin. Higher amount of hemicellulose had an obstructive effect on the enzymatic pre-treatment whereas lignin had no adverse effect on enzyme accessibility. Increased amount of charged groups improved the accessibility for enzymes. Both hemicellulose and lignin were carboxymethylated when pre-treatment by carboxymethylation was employed. However, carboxymethylation partly dissolved hemicelluloses. The tensile strength of CNF films was independent of the chemical composition of the pulp and the pre-treatment strategy. However, since the enzymatic pre-treatment decreased the cellulose DP more, CNF films from enzymatically pre-treated pulps had generally lower tensile strength. © 2022, The Author(s).

  • 329.
    Brännvall, Elisabet
    et al.
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Bäckström, Marie
    RISE, Innventia.
    Improved impregnation efficiency and pulp yield of softwood kraft pulp by high effective alkali charge in the impregnation stage2016In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 70, no 11, p. 1031-1037Article in journal (Refereed)
    Abstract [en]

    A pulp yield increase up to 2% can be achieved by impregnation with a liquor containing 2 M effective alkali (EA) concentration instead of 1 M. The yield increase is due to higher cellulose and glucomannan contents in the pulp, which can be rationalized by less yield loss by peeling, as impregnation is more effective at an elevated EA level. A rapid loading of chips with alkali can be realized due to a high diffusion rate. When the temperature becomes higher in the cooking stage, enough alkali is available for delignification reactions without the risk of alkali depletion in the chip core, so that the delignification is more homogeneous.

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  • 330.
    Brännvall, Elisabet
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Kulander, Ida
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Consequences in a softwood kraft pulp mill of initial high alkali concentration in the impregnation stage2019In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 34, no 1, p. 28-35Article in journal (Refereed)
    Abstract [en]

    Impregnation with high initial concentration is fast and efficient, leading to a homogeneous delignification in the subsequent cook, resulting in improved screened pulp yield. To obtain high initial alkali concentration, the white liquor flow needs to be significantly increased. The moisture content of the wood chips and the alkali concentration of the white liquor limit the initial alkali concentration of the impregnation liquor that can be reached. It is therefore of interest to evaluate the possibility to implement high alkali impregnation (HAI) industrially and the consequences this would have on the mill system. The effect of HAI on mass and energy balances in a kraft pulp mill has been studied using mill model simulations. The sensitivity to disturbances in important parameters for process control has been compared to impregnation scenarios used industrially. It was shown that high initial alkali concentration can be achieved on industrial scale by increased white liquor flow. HAI has a positive effect on recovery flows and reduces the need for make-up chemicals. The HAI concept is less sensitive to variations in process parameters, such as chip moisture and white liquor concentration, thus diminishing the risk of alkali depletion in chip cores. © 2019 Brännvall and Kulander.

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  • 331.
    Brännvall, Elisabet
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Larsson, P Tomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Changes in the cellulose fiber wall supramolecular structure during the initial stages of chemical treatments of wood evaluated by NMR and X-ray scattering2021In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, p. 3951-3965Article in journal (Refereed)
    Abstract [en]

    The effect of initial stages of pulping of spruce, resembling prehydrolysis and alkaline cooking was studied using CP/MAS 13C-NMR, X-ray scattering, FSP and carbohydrate composition in order to study the impact of the pre-treatments on the fiber wall nanostructure. Removal of fiber wall components, hemicellulose and lignin, increased the fiber wall porosity and induced cellulose fibril aggregation. The effect of temperature and pH in the treatment on cellulose fibril aggregate size appears to be secondary. It is the removal of hemicellulose that has a profound effect on the supramolecular structure of the cellulose fiber wall. As the amount of hemicellulose dissolved from wood increases, the fibril aggregate size determined by NMR increases as well, ranging from 16 to 28 nm. Specifically, a good correlation between the amount of glucomannan in the fiber wall and the fibril aggregate size is seen. The lower the amount of glucomannan, the larger the aggregate size. Glucomannan thus seems to prevent aggregation as it acts as a very efficient spacer between fibrils. Elemental fibril size determined by NMR, was quite similar for all samples, ranging from 3.6 to 4.1 nm. By combining measurement methods, a more well-resolved picture of the structural changes occurring during was obtained. © 2021, The Author(s).

  • 332.
    Burström, Eric
    RISE, Swerea, Swerea MEFOS.
    Recent developments in injection technologies at MEFOS1996In: The Howard Worner International Symposium on Injection in Pyrometallurgy, Minerals, Metals & Materials Soc (TMS) , 1996, p. 47-57Conference paper (Refereed)
    Abstract [en]

    Injection technology has been an important subject from the early days of ladle metallurgy until the present. During the last decade, there have not been many publications in the area of injection technology. It is the author's opinion that with the challenge to find new solutions especially to environmental and energy related problems as well as better understanding of phenomenas from computer modelling, a new era of inventive injection technology developments is at hand. This is illustrated in the article with examples from six different areas where MEFOS is or have recently carried out R&D work related to issues from the injection technology field.

  • 333.
    Burström, Eric
    et al.
    MEFOS − Stiftelsen för Metallurgisk Forskning.
    Ye, Guozhu
    MEFOS − Stiftelsen för Metallurgisk Forskning.
    Refining of impurities from steel using ladle metallurgical methods1991In: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 20, no 2, p. 126-134Article in journal (Refereed)
    Abstract [en]

    Within the framework of a joint Swedish-Soviet co-operative project, refining of impurities in steel has been studied. The work was split in two parts: 1) refining of copper from steel melts; and 2) phosphorus removal under reducing conditions with subsequent slag destruction. Refining of copper was carried out in the laboratory and in one pilot trial. The laboratory tests showed notable copper removal with sodium-based reagents, but the consumption of reagents is very high in addition to the necessity for an extra desulphurizing operation. A few lab-tests with soda-based (Na2CO3) reagents show promising results which could lead to a more economical procedure. Phosphorus removal under reducing conditions followed by destruction of the slag has been performed for 100 kg and in a pilot study. In the pilot study a method has been developed with controlled destruction of the slag in the ladle before removal of the phosphorus-containing slag. Including the destruction, the total dephosphorization reached 35%.

  • 334.
    Butchosa, Nuria
    et al.
    KTH Royal Institute of Technology, Sweden.
    Brown, Christian J.L.
    KTH Royal Institute of Technology, Sweden.
    Larsson, Per Tomas
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Berglund, Lars A.
    KTH Royal Institute of Technology, Sweden.
    Bulone, Vincent
    KTH Royal Institute of Technology, Sweden.
    Zhou, Q.
    KTH Royal Institute of Technology, Sweden.
    Nanocomposites of bacterial cellulose nanofibers and chitin nanocrystals: Fabrication, characterization and bacterial activity2013In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, no 12, p. 3404-3413Article in journal (Refereed)
    Abstract [en]

    An environmentally friendly approach was implemented for the production of nanocomposites with bactericidal activity, using bacterial cellulose (BC) nanofibers and chitin nanocrystals (ChNCs). The antibacterial activity of ChNCs prepared by acid hydrolysis, TEMPO-mediated oxidation or partial deacetylation of α-chitin powder was assessed and the structure of the ChNC nanoparticles was characterized by X-ray diffraction, atomic force microscopy, and solid-state 13C-NMR. The partially deacetylated ChNCs (D-ChNC) showed the strongest antibacterial activity, with 99 ± 1% inhibition of bacterial growth compared to control samples. Nanocomposites were prepared from BC nanofibers and D-ChNC by (i) in situ biosynthesis with the addition of D-ChNC nanoparticles in the culture medium of Acetobacter aceti, and (ii) post-modification by mixing D-ChNC with disintegrated BC in an aqueous suspension. The structure and mechanical properties of the BC/D-ChNC nanocomposites were characterized by Fourier transform infrared spectroscopy, elemental analysis, field-emission scanning electron microscopy, and an Instron universal testing machine. The bactericidal activity of the nanocomposites increased with the D-ChNC content, with a reduction in bacterial growth by 3.0 log units when the D-ChNC content was 50%. D-ChNC nanoparticles have great potential as substitutes for unfriendly antimicrobial compounds such as heavy metal nanoparticles and synthetic polymers to introduce antibacterial properties to cellulosic materials.

  • 335.
    Buö, Finn Olav
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, CBI - Cement- och betonginstitutet.
    Temperaturförlopp i betongkonstruktioner under betongens hårdnande1967Report (Refereed)
  • 336.
    Byfors, Jan
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, CBI - Cement- och betonginstitutet.
    Plain concrete at early ages1980Report (Refereed)
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  • 337.
    Byfors, Kajsa
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, CBI - Cement- och betonginstitutet.
    Chloride-initiated reinforcement corrosion.: Chloride binding1990Report (Refereed)
  • 338.
    Bäckström, M.
    et al.
    RISE, Innventia.
    Bolivar, S.
    Paltakari, J.
    Effect of ionic form on fibrillation and the development of the fibre network strength during the refining of the kraft pulps2012In: O Papel, ISSN 0031-1057, no 7, p. 57-65Article in journal (Refereed)
  • 339.
    Bäckström, Marie
    et al.
    RISE, STFI-Packforsk.
    Drotz, Mattias
    RISE, STFI-Packforsk.
    Tubek-Lindblom, Anna
    RISE, STFI-Packforsk.
    Blohm, Erik
    RISE, STFI-Packforsk.
    Improved product quality and increased production capacity with impulse technology2009In: Pulp and Paper Canada, ISSN 03164004, Vol. 110, no 2, p. 33-36Article in journal (Refereed)
    Abstract [en]

    Impulse technology is a high-intensity web consolidation technique in which water is removed from a wet paper web by the combined action of mechanical pressure and intense heat. Pilot trials show that impulse technology is a feasible technique for the production of linerboard, paperboard and fine paper. Improved dewatering, combined with enhanced mechanical and surface properties, are benefits that can be obtained.

  • 340.
    Bäckström, Marie
    et al.
    RISE, Innventia.
    Hammar, Lars-Åke
    RISE, Innventia.
    The influence of the counter-ions to the charged groups on the refinability of never-dried bleached pulps2010In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 5, no 4, p. 2751-2764Article in journal (Refereed)
    Abstract [en]

    Refining of bleached hardwood pulps and bleached softwood pulps having different counter-ions to the charged groups within the fibres was studied. The results show that an energy reduction of 50% for the hardwood pulps and 20% for the softwood pulp can be achieved if 1he fibres are converted into the Na +-form prior to refining. The results also show that the amount of charged groups in the fibres is important for the refinability, which explains why the refining efficiency is much lower for bleached softwood fibres, which have a much smaller amount of charged groups than the bleached hardwood pulp.

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  • 341.
    Bäckström, Marie
    et al.
    RISE, STFI-Packforsk.
    Hammar, Lars-Åke
    RISE, STFI-Packforsk.
    Htun, Myat
    RISE, STFI-Packforsk.
    Beatability and runnability studies of ion-exchanged unbleached kraft pulps on a pilot scale2009In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, no 1, p. 94-100Article in journal (Refereed)
    Abstract [en]

    It has earlier been shown that the counter-ion to the charged groups in the fibre has a significant effect on the beatability of fibres, but large-scale investigations of this effect are scarce in the literature. The objectives of the present study were therefore to develop a technique to ion-exchange large quantities of industrial pulp into the Na +-form using complexing agents and to study the effect of industrial-scale refining on pulp fibres in the Na +-form and how the fibres respond to industrial-like papermaking. The results show that ion-exchange can indeed be conducted on a pilot-scale using complexing agents such as DTPA. The study further indicates that an energy reduction of 50% at a given WRV or tensile index may be achieved if the fibres are converted to Na +-form prior to pilot-scale refining. By applying these techniques in full-scale production, it should thus be possible to save significant amount of energy, especially in the case of papers made from unbleached pulp that usually demands a higher degree of beating to achieve sufficient strength.

  • 342.
    Bäckström, Marie
    et al.
    RISE, Innventia.
    Jensen, Anna
    RISE, Innventia.
    Brännvall, Elisabet
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Influence of chip presteaming conditions on kraft pulp composition and properties2016In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 70, no 5, p. 393-399Article in journal (Refereed)
    Abstract [en]

    Presteaming is a well-established technique in pulp mills, which improves cooking liquor impregnation by removing air from within and between chips. The aim of the study was to investigate how conditions during steaming affect the subsequent kraft cook and properties of the obtained pulp. It was found that higher pressure and temperature during chip presteaming led to increased degradation and dissolution of hemicelluloses. Lower refinability and tensile index was obtained for pulps cooked after presteaming at high pressure and for a long time.

  • 343.
    Bäckström, Marie
    et al.
    RISE, STFI-Packforsk.
    Kolar, Marie-Claude
    RISE, STFI-Packforsk.
    Htun, Myat
    RISE, STFI-Packforsk.
    Characterisation of fines from unbleached kraft pulps and their impact on sheet properties2008In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 62, no 5, p. 546-552Article in journal (Refereed)
    Abstract [en]

    Fines are an essential component in the papermaking process because they have a profound influence on the behaviour of the wet web and on the mechanical properties of the final sheet. Primary fines are present in the pulp prior to refining, and secondary fines are produced during refining. In the present investigation, two commercially manufactured unbleached pulps with kappa numbers of 45 and 90 were studied in terms of how they responded to refining with respect to the quality of fibre and fines. Primary and secondary fines were collected and characterised and their impact on sheet strength was evaluated by addition of known amounts to a refined and decrilled pulp. All the measured paper strength properties improved when primary and secondary fines were added. The strength improvement was generally somewhat higher in the second case. The effect was more pronounced at a higher level of addition. We attribute the main strength improvements associated with fines to improved consolidation by the creation of capillary forces between the surfaces.

  • 344.
    Bäckström, Marie
    et al.
    RISE, Innventia.
    Tubek-Lindblom, Anna
    RISE, Innventia.
    Wågberg, Lars
    RISE, Innventia.
    Studies of the influence of deflocculants and flocculants on the refining efficiency on a pilot scale2009In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, no 3, p. 319-326Article in journal (Refereed)
    Abstract [en]

    The objective of the present investigation was to study the influence of flocculants and deflocculants on refining efficiency. The refining was performed with the aid of a conical refiner at EuroFEX, and the refining response was evaluated as the change in fibre properties and in the mechanical properties of handsheets. Using the same furnish, an unbleached neverdried softwood pulp, the effect of fibre dimensions on floc strength was excluded as much as possible. The degree of flocculation was changed by addition of APAM, CPAM, guar gum and CMC. The floc strength was characterized using a parallel plate rheometer. The added chemicals, except for APAM, affected the relation between power input and gap clearance. To reach a certain power the fibres treated with guar gum, CMC or CPAM required a narrower gap clearance than the reference pulp or when APAM was added to the fibres. Refining at a narrower gap clearance increased the refining efficiency in terms of WRV and paper property development, as long as fibre length reduction could be avoided.

  • 345.
    Bågenholm-Ruuth, Edvin
    et al.
    Lund university, Sweden.
    Sanchis-Sebastiá, Miguel
    ShareTex AB, Sweden.
    Hollinger, Nadine
    MoRe Research Örnsköldsvik AB, Sweden.
    Teleman, Anita
    RISE Research Institutes of Sweden.
    Larsson, Per Tomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Wallberg, Ola
    Lund university, Sweden.
    Transforming post-consumer cotton waste textiles into viscose staple fiber using hydrated zinc chloride2023In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed)
    Abstract [en]

    Large amounts of cellulose-based waste textiles are generated every year, yet little is done to recycle this waste. Alternatives such as fiber-to-fiber recycling, where a significant part of the value of the waste textiles is recovered, are attractive possibilities. In this study, we have investigated the viability of using hydrated zinc chloride (ZnCl2·4H2O) as a solvent and swelling agent to convert cotton waste textiles (the most abundant cellulose-based waste textile) into a dissolving pulp that can be used as raw material for the production and spinning of viscose fibers. The solvent produced an accessible dissolving pulp and exhibited excellent recyclability, maintaining good dissolving power even after repeated recycling. The dissolving pulp was subsequently used to produce viscose dope, a spinning solution which was spun and cut into viscose staple fibers. The viscose dope exhibited good properties (moderate filter clogging value and gamma number), and the resulting staple fibers were strong and of good quality (high linear density, elongation, and tenacity). These results illustrate the potential of using hydrated zinc chloride for the production of viscose grade dissolving pulp from cotton waste textiles. 

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  • 346.
    Caddéo, Sophie
    et al.
    RISE, Swerea, Swerea KIMAB.
    Strondl, Annika
    RISE, Swerea, Swerea KIMAB.
    Söderberg, Hans
    RISE, Swerea, Swerea KIMAB.
    Study on oxygen reduction effects due to sintering parameters for sintered steel materials2012Report (Refereed)
    Abstract [sv]

    Three sinter steel materials, AD15, AD4 and Astaloy CrM, have been under evaluation in this study. The study has been focusing on three types of trials in order to see how the sintering parameters influence the reduction of oxides. The first series of trails were focused on how the green body density affects the reduction rate. The second and third series of trail were more focused on the sintering parameters, i.e. sintering time and sintering atmospheres, respectively. For sinter steel pellets a clear effect of the green body density can be seen on PAS and oxygen analyses. A higher green body density decreases the oxygen reduction reactions during sintering and results in higher oxygen content in the final pellet. How the hydrogen content in the sintering atmosphere affects the reduction efficiency is still not clear as the results from the PAS and the chemical and microstructure analysis had different outcome. Further studies are required. The total reduction time has effect on the reduction result i.e. a longer reduction time will reduce more than a faster reduction time.

  • 347.
    Camara, Alexandre R.
    et al.
    Rio de Janeiro State University, Brazil; Pontifical Catholic University of Rio de Janeiro, Brazil.
    Pereira, Joao
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Tarasenko, Oleksandr
    RISE, Swedish ICT, Acreo, Fiber Optics.
    Margulis, Walter
    RISE, Swedish ICT, Acreo, Fiber Optics. KTH Royal Institute of Technology, Sweden.
    Carvalho, Isabel C. S.
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Optical creation and erasure of the linear electrooptical effect in silica fiber2015In: Optics Express, E-ISSN 1094-4087, Vol. 23, no 14, p. 18060-18069Article in journal (Refereed)
    Abstract [en]

    We study the creation and erasure of the linear electrooptical effect in silicate fibers by optical poling. Carriers are released by exposure to green light and displaced with simultaneous application of an internal dc field. The second order nonlinear coefficient induced grows with poling bias. The field recorded (~108 V/m) is comparable to that obtained through classical thermal poling of fibers. In the regime studied here, the second-order nonlinearity induced (~0.06 pm/V) is limited by the field applied during poling (1.2 × 108 V/m). Optical erasure with high-power green light alone is very efficient. The dynamics of the writing and erasing process is discussed, and the two dimensional (2D) field distribution across the fiber is simulated.

  • 348.
    Cameron, Christopher
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Saseendran, Sibin
    RISE Research Institutes of Sweden.
    Stig, Fredrik
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Rouhi, Mohammad
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites. National University of Singapore, Singapore.
    A rapid method for simulating residual stress to enable optimization against cure induced distortion2021In: Journal of composite materials, ISSN 0021-9983, E-ISSN 1530-793X, Vol. 55, no 26, p. 3799-Article in journal (Refereed)
    Abstract [en]

    In this paper a rapid method for residual cure stress analysis from composite manufacturing is presented. The method uses a high-fidelity path-dependent cure kinetics subroutine implemented in ABAQUS to calibrate a linear elastic model. The path-dependent model accounts for the tool-part interaction, forming pressure, and the changing composite modulus during the rubbery phase of matrix curing. Results are used to calculate equivalent lamina-wise coefficients of thermal expansion (CTE) in 3 directions for a linear temperature analysis. The goal is to accurately predict distortions for large complex geometries as rapidly as possible for use in an optimization framework. A carbon-epoxy system is studied. Simple coupons and complex parts are manufactured and measured with a 3 D scanner to compare the manufactured and simulated distortion. Results are presented and the accuracy and limitations of the rapid simulation method are discussed with particular focus on implementation in a numerical optimization framework. © The Author(s) 2021.

  • 349.
    Candiani, A
    et al.
    RISE, Swedish ICT, Acreo, Fiber Optics.
    Margulis, W
    VIKTORIA.
    Konstantaki, M
    RISE, Swedish ICT, Acreo, Fiber Optics.
    Pissadakis, S
    RISE, Swedish ICT, Acreo, Fiber Optics.
    Ferrofluid-infiltrated optical fibers for shear-sensing smart pads2012In: SPIE NewsroomArticle in journal (Other academic)
  • 350.
    Canturri, C.
    et al.
    Imperial College London.
    Greenhalgh, E.S.
    Imperial College London.
    Pinho, S.T.
    Imperial College London.
    Nilsson, Sören
    RISE, Swerea, Swerea SICOMP.
    Delamination growth mechanism from embedded defects in compression2011In: ICCM International Conferences on Composite MaterialsConference paper (Refereed)
45678910 301 - 350 of 2745
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