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  • 1.
    Aadland, Reidun C.
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Akarri, Salem
    NTNU Norwegian University of Science and Technology, Norway.
    Heggset, Ellinor B
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Syverud, Kristin
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. NTNU Norwegian University of Science and Technology, Norway.
    Torsæter, Ole
    NTNU Norwegian University of Science and Technology, Norway.
    A core flood and microfluidics investigation of nanocellulose as a chemical additive to water flooding for eor2020Ingår i: Nanomaterials, E-ISSN 2079-4991, Vol. 10, nr 7, artikel-id 1296Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose nanocrystals (CNCs) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)- oxidized cellulose nanofibrils (T-CNFs) were tested as enhanced oil recovery (EOR) agents through core floods and microfluidic experiments. Both particles were mixed with low salinity water (LSW). The core floods were grouped into three parts based on the research objectives. In Part 1, secondary core flood using CNCs was compared to regular water flooding at fixed conditions, by reusing the same core plug to maintain the same pore structure. CNCs produced 5.8% of original oil in place (OOIP) more oil than LSW. For Part 2, the effect of injection scheme, temperature, and rock wettability was investigated using CNCs. The same trend was observed for the secondary floods, with CNCs performing better than their parallel experiment using LSW. Furthermore, the particles seemed to perform better under mixed-wet conditions. Additional oil (2.9–15.7% of OOIP) was produced when CNCs were injected as a tertiary EOR agent, with more incremental oil produced at high temperature. In the final part, the effect of particle type was studied. T-CNFs produced significantly more oil compared to CNCs. However, the injection of T-CNF particles resulted in a steep increase in pressure, which never stabilized. Furthermore, a filter cake was observed at the core face after the experiment was completed. Microfluidic experiments showed that both T-CNF and CNC nanofluids led to a better sweep efficiency compared to low salinity water flooding. T- CNF particles showed the ability to enhance the oil recovery by breaking up events and reducing the trapping efficiency of the porous medium. A higher flow rate resulted in lower oil recovery factors and higher remaining oil connectivity. Contact angle and interfacial tension measurements were conducted to understand the oil recovery mechanisms. CNCs altered the interfacial tension the most, while T-CNFs had the largest effect on the contact angle. However, the changes were not significant enough for them to be considered primary EOR mechanisms.

  • 2.
    Aaen, Ragnhild
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Lehtonen, Mari
    University of Helsinki, Finland.
    Mikkonen, Kirsi
    University of Helsinki, Finland.
    Syverud, Kristin
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. NTNU Norwegian University of Science and Technology, Norway.
    Combining cellulose nanofibrils and galactoglucomannans for enhanced stabilization of future food emulsions2021Ingår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, nr 16, s. 10485-10500Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of wood-derived cellulose nanofibrils (CNFs) or galactoglucomannans (GGM) for emulsion stabilization may be a way to obtain new environmentally friendly emulsifiers. Both have previously been shown to act as emulsifiers, offering physical, and in the case of GGM, oxidative stability to the emulsions. Oil-in-water emulsions were prepared using highly charged (1352 ± 5 µmol/g) CNFs prepared by TEMPO-mediated oxidation, or a coarser commercial CNF, less charged (≈ 70 µmol/g) quality (Exilva forte), and the physical emulsion stability was evaluated by use of droplet size distributions, micrographs and visual appearance. The highly charged, finely fibrillated CNFs stabilized the emulsions more effectively than the coarser, lower charged CNFs, probably due to higher electrostatic repulsions between the fibrils, and a higher surface coverage of the oil droplets due to thinner fibrils. At a constant CNF/oil ratio, the lowest CNF and oil concentration of 0.01 wt % CNFs and 5 wt % oil gave the most stable emulsion, with good stability toward coalescence, but not towards creaming. GGM (0.5 or 1.0 wt %) stabilized emulsions (5 wt % oil) showed no creaming behavior, but a clear bimodal distribution with some destabilization over the storage time of 1 month. Combinations of CNFs and GGM for stabilization of emulsions with 5 wt % oil, provided good stability towards creaming and a slower emulsion destabilization than for GGM alone. GGM could also improve the stability towards oxidation by delaying the initiation of lipid oxidation. Use of CNFs and combinations of GGM and CNFs can thus be away to obtain stable emulsions, such as mayonnaise and beverage emulsions. © 2021, The Author(s).

  • 3.
    Aamodt, Edvard
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Holmvaag, Anders Ole
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Sanfeliu Melia, Cristina
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Erfaringer med mobile vanntåkeanlegg installert i boliger2022Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Experiences regarding personal protection water mist systems installed in dwellings. Personal protection water mist systems can produce a water mist that can cool down and limit a fire in a small area in a dwelling. The system is equipped with sensitive detectors which can activate the system in the early stages of the fire and limit the fire spread, and in some cases extinguish the fire. This gives more time for evacuation, which can be especially important for vulnerable people with risk factors, like impaired cognitive and physical functioning. The goal of this study has been to map the experiences in Norway regarding personal protection water mist systems, considering how the municipalities have experienced the work related to the systems and whether the systems have activated and saved lives. This will shed light upon whether mobile water mist systems are appropriate measures for vulnerable people in the society, and the risk factors that determine whether the measure is appropriate or not. This study has used literature studies, questionnaires, and interviews to map the experiences of personal protection water mist systems in Norway. The results showed that personal protection water mist systems installed in Norwegian dwellings have been activated in connection with fire outbreaks, and thus limited or extinguished the fire. This has saved lives on several occasions and reduced the damage potential. There are many people who have risk factors that make it appropriate to install a mobile water mist system in their home, but there are also exceptions. The risk factors that indicate that it is beneficial to install mobile water mist systems in Norwegian dwellings are - Impaired cognitive abilities - Impaired physical abilities - Drug and alcohol problems - Smoking - Living alone The systems are particularly suitable when several of the risk factors are present at the same time. It was also shown that personal protection water mist systems are not suitable for mobile people who spend time in several places in the home and are therefore often outside the system's coverage area. Personal protection water mist systems are not recommended for people who may have the potential to sabotage the system. In questionnaires and interviews, it emerged that there are big differences between how Norwegian municipalities work with assigning, installing, operating, and maintaining personal protection water mist systems. In larger municipalities, there are more people who rely on routines and formal processes for the work, and there is therefore a greater proportion of the larger municipalities who distribute the facilities out to individuals than in the small municipalities where the work is more characterised by informal routines and personal relations. 3 Based on the results from this study, it is our opinion that the following aspects should be covered by future work: • Need for a new and updated cost-benefit analysis for personal protection water mist systems. • Need for a better statistical basis for assessment of the personal protection water mist systems. • Need for a Norwegian test standard for personal protection water mist systems. • Need for clear guidelines for assignment, procurement, installing, operation, and maintenance of personal protection water mist systems.

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  • 4.
    Aamodt, Edvard
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Säkerhetsforskning.
    Meraner, Christoph
    RISE Research Institutes of Sweden, Säkerhet och transport, Säkerhetsforskning.
    Brandt, Are W
    RISE Research Institutes of Sweden, Säkerhet och transport, Säkerhetsforskning.
    Review of efficient manual fire extinguishing methods and equipment for the fire service2020Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The late 90s and the early 2000s was a period with relative extensive research and innovation in the area of manual fire extinguishing methods and equipment for the fire service. New equipment such as the cutting extinguisher and extinguishing spears allowed to conduct offensive attacks from the exterior of a building, reducing the exposure of fire fighters to fire and smoke and their associated risks in general. This led to the development of new firefighting tactics, as for example the Quadrant Model of the Dutch fire service, which extends the “traditional” offensive interior attack and defensive exterior attack by the offensive exterior attack and defensive interior attack.Recently the research focus has furthermore increasingly shifted to environmental aspects, such as the water consumption and effect of additives (i.e., foam) on humans and the environment. Extinguishing with smaller amounts of water is beneficial for the environment, reduces water damage and lowers the burden on the water delivery system.ConclusionIn conclusion, the systems most relevant to be further tested in a fire situation in a small house or dwelling are the cutting extinguisher and the extinguishing spear.These systems are different in operation but have both shown to be promising with regard to fulfilling the different objectives of the overall project. Being relatively easy to utilize with the right training during internal extinguishing efforts executed from the outside of the building, and being only water based to minimize contamination, due to lower water consumption, of the surrounding areas give these systems advantages over conventional equipment.Especially if the systems are used in combination with an IR camera to locate the fire, the extinguishing efforts can be started early and effectively, and the water amount needed to control the fire may be reduced. The need for firefighters with breathing apparatus is reduced as well, hence reducing the smoke exposure to firefighters.The fact that the fire service also recognizes the potential of using these systems early in the extinguishing efforts, and is working on implementing them, prompts the need for scientific backup.

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  • 5.
    Aamodt, Edvard
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Brandteknik.
    Rønning, Birger
    RISE Research Institutes of Sweden, Säkerhet och transport, Brandteknik.
    Sikkerhetsbehov for kullgriller i restauranter2020Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The RISE report 2019:04 «Charcoal and wood burning ovens in restaurants – Fire safety and documentation requirements» [1] investigated regulations and documental demands tied to charcoal and wood burning ovens in restaurants in Norway. A part of the conclusion in this report emphasized the need for, through physical testing, mapping whether existing test standards covers the safety requirements of charcoal ovens in restaurants. NS-EN 13240:2001 «Roomheaters fired with solid fuel. Requirements and test methods» [2] was chosen as a relevant test standard. Three test ovens (a closed test oven, a dummy oven and an open test oven) was produced at RISE Fire Research. Their construction with regard to insulation capabilities, materials and dimensions was based on existing charcoal ovens placed on the Norwegian marked. This was done to achieve an objective depiction of the issue, without the need for a specific brand of ovens. Restaurant oven charcoal was utilized to achieve as real heat development as possible in the test ovens. The test layout is based on NS-EN 12340:2001, with a test rigg constructed of two «safety walls», ceiling and floor attached with thermocouples. Temperatures from the test oven are registered in the safety walls at several positions according to a standardised grid, and in the ceiling and the floor each have one single measurement position measuring warmest point. Thermocouples in the chimney and exhaust duct measured the flue gas temperatures transported to the exhaust system. Four different tests were conducted, where the first one was a standardized safety test including the closed oven model. The second test was the same safety test setup with the dummy oven besides the closed oven. The dummy contained a built-in propane burner to simulate the heat load from a real oven. The purpose was to simulate two ovens placed next to each other. The third test was an overload test on the closed test oven with 150 % fuel load and higher refuelling frequency. The last test was a test of the open test oven. The safety test method described in NS-EN 13240:2001 is suitable to test the level of stable maximal temperature in the surrounding combustible materials, in the same way as for roomheaters, which the method is designed for. The method addresses safety aspects such as surface temperatures and handles on the oven. Tests show that the temperatures developed in the ovens have the potential to breech the temperature criterion given by the test standard, and therefore contribute to the ignition of surrounding combustible materials. Such situations pose a fire risk and safety measures regarding this aspect must be documented by the producer. NS-EN13240:2001 does not cover temperatures for exhaust duct and the production of sparks and their possible spread to combustible materials. These are important safety aspects which must be addressed when documenting the fire safety of restaurant grills. Tests show that sparks are created in the oven, including from restaurant charcoal fuel, and are transported into the exhaust duct, and out through the opening of the grill door. Together with high flue gas temperatures in the exhaust duct and deposits of soot and cooking oil this pose a fire risk. Documentation must therefore be presented, showing that the oven is equipped with measures (for instance spark screen) which guards the exhaust duct from sparks to a satisfactory degree. Operators of the oven must receive adequate training and must operate the closed oven with caution, as to avoid incidents with sparks being released though the door. The placement of ovens next to each other does not seem to increase the heat load on surrounding walls but may lead to increased temperatures in between the ovens. The consequences of temperature increases must be documented. Tests show that overloading with fuel and intensifying the refuelling intervals can lead to increased temperatures in the oven, which can affect materials and welding seams. Overloading can also affect the temperatures towards surrounding walls and exhaust ducts and therefore may affect fire safety negatively. NS-EN 13240:2001 requires the producer to documents how the oven is constructed and of what materials, and that the welding seams are dimensioned for the materials used. It is recommended that the producer documents the safety level of the oven materials with an overload test. It must also be documented that the exhaust ducts in which the flue gas are transported are constructed to handle the potential temperatures that can arise, including erroneous use.

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  • 6.
    Aamodt, Edvard
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Steen-Hansen, Anne
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet. NTNU, Norway.
    Holmvaag, Ole Anders
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    LEARNING FROM FIRE INCIDENTS : Analysis of a devastating fire in a building with municipal housing in Norway2022Ingår i: Proceedings of the 32nd European Safety and Reliability Conference (ESREL 2022), 2022, s. 1156-Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article presents an analysis of a fire in a municipal apartment building used as housing for people with challenges connected to drug addiction. The fire took place in Norway 7th of August 2021. The incident happened during the night and the fire was spreading quickly and intensely via the external wooden balconies. The combination of risk factors both connected to the fire development and the characteristics of the occupants raises the potential for fire fatalities. This analysis seeks to understand why the fire spread with such a speed, and how everyone in the building survived without injuries. The analysis identified both technical and human factors that may help to answer these questions. The findings suggest that there were deficiencies connected to the technical fire safety design that if improved could have reduced the fire damage. Factors promoting the fire spread and fire intensity include the choice of wood material used in the construction of the balconies, no sprinkler system installed on the balconies and a large fire load on the balconies caused by the occupants’ tendency to accumulate possessions on the balconies. Factors contributing to the outcome of no injuries or fatalities included occupants being awake during these late hours, and the strong social network between them. Such a network should be seen as a positive factor regarding robustness against fire and should be encouraged.

  • 7.
    Aamodt, Edvard
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Steen-Hansen, Anne
    Holmvaag, Ole Anders
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Olsen, Vegard E
    Multiconsult, Norway.
    Hermansen, Anna-Karin
    TBRT, Norway.
    Hermansen, Arild
    TBRT, Norway.
    Log, Torgrim
    Gassco, Norway.
    Opstad, Kristen K
    NTNU, Norway.
    Hagen, Bjarne C
    HVL, Norway.
    Analyse av brann i kommunalt boligbygg i Bergen 7. august 20212023Rapport (Övrigt vetenskapligt)
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  • 8.
    Aarstad, Olav
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Heggset, Ellinor B
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, PFI.
    Pedersen, Ina Sander
    NTNU Norwegian University of Science and Technology, Norway.
    Björnöy, Sindre H.
    NTNU Norwegian University of Science and Technology, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, PFI.
    Strand, Berit L.
    NTNU Norwegian University of Science and Technology, Norway.
    Mechanical properties of composite hydrogels of alginate and cellulose nanofibrils2017Ingår i: Polymers, E-ISSN 2073-4360, Vol. 9, nr 8, artikel-id 378Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alginate and cellulose nanofibrils (CNF) are attractive materials for tissue engineering and regenerative medicine. CNF gels are generally weaker and more brittle than alginate gels, while alginate gels are elastic and have high rupture strength. Alginate properties depend on their guluronan and mannuronan content and their sequence pattern and molecular weight. Likewise, CNF exists in various qualities with properties depending on, e.g., morphology and charge density. In this study combinations of three types of alginate with different composition and two types of CNF with different charge and degree of fibrillation have been studied. Assessments of the composite gels revealed that attractive properties like high rupture strength, high compressibility, high gel rigidity at small deformations (Young’s modulus), and low syneresis was obtained compared to the pure gels. The effects varied with relative amounts of CNF and alginate, alginate type, and CNF quality. The largest effects were obtained by combining oxidized CNF with the alginates. Hence, by combining the two biopolymers in composite gels, it is possible to tune the rupture strength, Young’s modulus, syneresis, as well as stability in physiological saline solution, which are all important properties for the use as scaffolds in tissue engineering.

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  • 9.
    Abbadessa, Anna
    et al.
    KTH Royal institute of Technology, Sweden.
    Dogaris, Ioannis
    KTH Royal institute of Technology, Sweden.
    Kishani Farahani, Saina
    KTH Royal institute of Technology, Sweden.
    Reid, Michael S.
    KTH Royal institute of Technology, Sweden.
    Rautkoski, Hille
    VTT Technical Research Centre of Finland, Finland.
    Holopainen-Mantila, Ulla
    VTT Technical Research Centre of Finland, Finland.
    Oinonen, Petri
    Ecohelix, Sweden.
    Henriksson, Gunnar
    KTH Royal institute of Technology, Sweden.
    Layer-by-layer assembly of sustainable lignin-based coatings for food packaging applications2023Ingår i: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 182, artikel-id 107676Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Packaging plays a critical role in ensuring food safety and shelf life by protecting against e.g., moisture, gases, and light. Polyethylene (PE) is widely used in food packaging, but it is mainly produced from non-renewable resources and it is an inefficient oxygen and light barrier. In this study, the layer-by-layer (LbL) assembly of a sustainably produced lignin-based polymer (EH) with polyethylenimine (PEI) or chitosan (CH) was used to fabricate (partially or fully) bio-based coatings with the aim of improving barrier properties of PE films. The charge density of EH was calculated using a polyelectrolyte titration method and the hydrodynamic diameters of EH, PEI and CH were determined by Dynamic Light Scattering (DLS). LbL assembly was monitored in situ via Quartz Crystal Microbalance with Dissipation (QCM-D) and Stagnation Point Adsorption Reflectometry (SPAR). PE films were coated with a variable number of PEI/EH or CH/EH bilayers (BL) using an immersive LbL assembly method. Coated films were studied in terms of light-blocking ability, wettability, thermal behaviour, surface structure, as well as oxygen and water vapor barrier properties. QCM-D and SPAR data showed a stepwise multilayer formation and strong interactions between the oppositely charged polymers, with PEI/EH coating having a greater amount of deposited polymer compared to CH/EH coating at the same number of BL. Overall, light barrier properties and wettability of the coated films increased with the number of deposited bilayers. Coated PE films maintained the overall thermal behaviour of PE. A number of BL of 20 was found to be the most promising based on the studied properties. Selected samples showed improved oxygen and water vapor barrier properties, with PEI/EH coating performing better than CH/EH coating. Taken altogether, we demonstrated that a novel and sustainable lignin-based polymer can be combined with PEI or CH to fabricate (partially or fully) bio-based coatings for food packaging. 

  • 10.
    Abbas, Khizra
    et al.
    KTH Royal Institute of Technology, Sweden.
    Nee, Hans-Peter
    KTH Royal Institute of Technology, Sweden.
    Kostov, Konstantin Stoychev
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Autonomously Modulating Gate Drivers For Triangular-Current Mode (TCM) Zero-Voltage Switching (ZVS) Buck Converter2023Ingår i: Proceedings of 22nd International Symposium on Power Electronics, Ee 2023, Institute of Electrical and Electronics Engineers Inc. , 2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper introduces a novel approach to designing autonomous gate drivers for soft-switched buck converters. The objective is to reduce switching losses, enhance converter efficiency, and reduce electromagnetic interference (EMI). The uniqueness of this converter is that the pulse-width modulation is performed autonomously on the gate driver. The gate driver makes quick decisions on switching times, capitalizing on the minimal time delay between measurements and switching. In the proposed buck converter configuration, the gate driver senses both the current and voltage across the switches to avoid delay. When a slightly negative voltage is detected across the switch, it rapidly turns on, resulting in a zero-voltage switching (ZVS). With an external snubber capacitor placed across the switches, the turn-off switching losses are zero (ZVS). Hence, both the turn-on and turn-off of the switch are soft. To enable the switch to turn off, a reference value of the switch current needs to be sent out to the gate driver using a galvanically isolated current sensor. Through this approach, the efficiency of the 7 kW buck converter has been calculated to exceed 99% without including the filter losses. Additional benefits include reduced switch stresses, diminished electromagnetic interference (EMI), and simplified thermal management.

  • 11.
    Abbas, Zainab
    et al.
    KTH Royal Institute of Technology, Sweden.
    Al-Shishtawy, Ahmad
    RISE - Research Institutes of Sweden, ICT, SICS.
    Girdzijauskas, Sarunas
    RISE - Research Institutes of Sweden, ICT, SICS. KTH Royal Institute of Technology, Sweden.
    Vlassov, Vladimir
    KTH Royal Institute of Technology, Sweden.
    Short-Term Traffic Prediction Using Long Short-Term Memory Neural Networks2018Ingår i: Proceedings - 2018 IEEE International Congress on Big Data, BigData Congress 2018 - Part of the 2018 IEEE World Congress on Services, Institute of Electrical and Electronics Engineers Inc. , 2018, s. 57-65Konferensbidrag (Refereegranskat)
    Abstract [en]

    Short-term traffic prediction allows Intelligent Transport Systems to proactively respond to events before they happen. With the rapid increase in the amount, quality, and detail of traffic data, new techniques are required that can exploit the information in the data in order to provide better results while being able to scale and cope with increasing amounts of data and growing cities. We propose and compare three models for short-term road traffic density prediction based on Long Short-Term Memory (LSTM) neural networks. We have trained the models using real traffic data collected by Motorway Control System in Stockholm that monitors highways and collects flow and speed data per lane every minute from radar sensors. In order to deal with the challenge of scale and to improve prediction accuracy, we propose to partition the road network into road stretches and junctions, and to model each of the partitions with one or more LSTM neural networks. Our evaluation results show that partitioning of roads improves the prediction accuracy by reducing the root mean square error by the factor of 5. We show that we can reduce the complexity of LSTM network by limiting the number of input sensors, on average to 35% of the original number, without compromising the prediction accuracy. .

  • 12.
    Abbasi, Abdul G
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Rydberg, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Jordbruk och livsmedel.
    Altmann, Peter
    Digg Agency for Digital Government, Sweden.
    Towards a verifiable and secure data sharing platform for livestock supply chain2022Ingår i: Proceedings of the 2022 IEEE International Conference on Dependable, Autonomic and Secure Computing, International Conference on Pervasive Intelligence and Computing, International Conference on Cloud and Big Data Computing, International Conference on Cyber Science and Technology Congress, DASC/PiCom/CBDCom/CyberSciTech 2022, Institute of Electrical and Electronics Engineers Inc. , 2022Konferensbidrag (Refereegranskat)
    Abstract [en]

    The digitization of a supply chain involves satisfying several functional and non-functional context specific requirements. The work presented herein builds on efforts to elicit trust and profit requirements from actors in the Swedish livestock supply chain, specifically the beef supply chain. Interviewees identified several benefits related to data sharing and traceability but also emphasized that these benefits could only be realized if concerns around data security and data privacy were adequately addressed. We developed a data sharing platform as a response to these requirements. Requirements around verifiability, traceability, secure data sharing of potentially large data objects, fine grained access control, and the ability to link together data objects was realized using distributed ledger technology and a distributed file system. This paper presents this data sharing platform together with an evaluation of its usefulness in the context of beef supply chain traceability. 

  • 13.
    Abbasi, Abdul Gahafoor
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Khan, Zaheer
    University of the West of England, UK.
    Veidblock: Verifiable identity using blockchain and ledger in a software defined network2017Ingår i: UCC 2017 Companion - Companion Proceedings of the 10th International Conference on Utility and Cloud Computing, Association for Computing Machinery, Inc , 2017, s. 173-179Konferensbidrag (Refereegranskat)
    Abstract [en]

    Blockchain and verifiable identities have a lot of potential in future distributed software applications e.g. smart cities, eHealth, autonomous vehicles, networks, etc. In this paper, we proposed a novel technique, namely VeidBlock 1 , to generate verifiable identities by following a reliable authentication process. These entities are managed by using the concepts of blockchain ledger and distributed through an advance mechanism to protect them against tampering. All identities created using VeidBlock approach are verifiable and anonymous therefore it preserves user’s privacy in verification and authentication phase. As a proof of concept, we implemented and tested the VeidBlock protocols by integrating it in a SDN based infrastructure. Analysis of the test results yield that all components successfully and autonomously performed initial authentication and locally verified all the identities of connected components.

  • 14.
    Abdelaziz, Omar
    et al.
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Capanema, Ewellyn
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Ajao, Olumoye
    Canmet ENERGY, Canada.
    Kristensen, Tove
    Lund University, Sweden.
    Hosseinaei, Omid
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Benali, Marzouk
    Canmet ENERGY, Canada.
    Hulteberg, Christian
    Lund University, Sweden.
    A Rapid and Tunable Approach for the Fractionation of Technical Kraft Lignin2023Ingår i: Chemical Engineering Transactions, ISSN 1974-9791, E-ISSN 2283-9216, Vol. 99, s. 67-72Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reducing the heterogeneity of technical lignin is essential to obtain predictable and high-performance polymeric materials that are suitable for high-value applications. Organic solvents with different polarities and solubilities can be used to fractionate lignin and reduce the complexity and diversity of its chemical structure. Among the various solvents and solvent mixtures, acetone-water mixtures offer an energy-efficient, cost-effective, and environmentally friendly means of lignin fractionation. In the present study, temperature-induced acetone-water fractionation was investigated to refine the properties of a technical softwood Kraft lignin, i.e., LignoBoost™ lignin. Relatively mild operating conditions were tested, namely, temperatures of 70-110°C and autogenous pressure. A factorial experimental design was developed using the Design-Expert® software, and three factors (temperature, time, and acetone concentration) were investigated. It was found that temperature-induced fractionation could increase lignin homogeneity and maintain high lignin solubilization with a short processing time (<1 h). It was also possible to tune the properties of the soluble lignin fraction (yield and weight-average molecular weight) based on the factorial models developed. The techno-economic evaluation confirmed the commercial viability of this fractionation process. 

  • 15.
    Abdelraheem, Mohammed Ahmed
    et al.
    RISE., Swedish ICT, SICS, Security Lab.
    Gehrmann, Christian
    RISE., Swedish ICT, SICS, Security Lab.
    Lindström, Malin
    Blekinge Institute of Technology, Sweden.
    Nordahl, Christian
    Blekinge Institute of Technology, Sweden.
    Executing Boolean Queries on an Encrypted Bitmap Index2016Ingår i: CCSW 2016: Proceedings of the 2016 ACM on Cloud Computing Security Workshop, 2016, s. 11-22Konferensbidrag (Refereegranskat)
    Abstract [en]

    We propose a simple and efficient searchable symmetric encryption scheme based on a Bitmap index that evaluates Boolean queries. Our scheme provides a practical solution in settings where communications and computations are very constrained as it offers a suitable trade-off between privacy and performance.

  • 16.
    Abdollahi, Elnaz
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Hamon, Camille
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Potential profits from ancillary service markets2023Rapport (Övrigt vetenskapligt)
    Abstract [en]

    In this deliverable from the SeCoHeat project, profits that can be made with 1 MWh of electricity production capacity on existing ancillary service markets are evaluated in 2020 and 2021. Profits are evaluated for four different marginal production costs corresponding to the following fuels for a CHP power plant: waste (assumed fuel price: 0 kr/MWh), recycled wood (10 kr/MWh), wood chips (20 kr/MWh) and wood pellets (30 kr/MWh). The results show that except for wood chips and wood pellets in 2020, the most profitable ancillary service markets are FFR (fast-frequency response) and aFRR down (automatic frequency restoration reserves for down-regulation). The reasons are that (1) producers don’t have to withhold capacity from the day-ahead market when their participate in these two markets and (2) producers get compensated for the capacity reserved for the ancillary service markets. For wood chips, the FFR market was the most profitable in 2020, followed by the mFRR down market (manual frequency restoration reserves for down-regulation). The reason for the mFRR down market to be more profitable than the aFRR down market for this fuel is that the profits from mFRR down depend on the avoided fuel costs, which are higher for wood chips than for waste and recycled wood. In 2021, all prices started increasing significantly, which decreased the relative profitability of the mFRR down compared to other markets. For wood pellets, the mFRR down market was also the second most profitable market in 2020, for the same reasons. The most profitable one in 2020 was the mFRR up market (manual frequency restoration reserves for up-regulation). The reason is that the higher fuel price of these two fuels entails low participation in the day-ahead market. Therefore, withholding capacity from the day-ahead market to be able to participate on the mFRR up market brings additional profits. In 2021, however, day-ahead prices started increasing significantly (a trend that continued into 2022) and the mFRR up market became the least profitable market for these two fuels. The profit evaluation performed in this deliverable is purely economic. It does not include the sector coupling to the heat sector (which entails limitation of the available electricity production capacity but also a possibility to store heat if storage is available) nor does it include other technical limitations such as ramp rates. These aspects will be considered in follow-up work in this project. This report has been compiled within the scope of the project SeCoHeat - Sector coupling of district heating with the electricity system: profitability and operation. The project is financed by the Research and Development Foundation of Göteborg Energi.

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  • 17.
    Abdul Hamid, Akram
    et al.
    Lund University, Sweden.
    von Platten, Jenny
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation. Lund University, Sweden.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Johansson, Dennis
    Lund University, Sweden.
    Bagge, Hans
    Lund University, Sweden.
    Determining the Impact of High Residential Density on Indoor Environment, Energy Use, and Moisture Loads in Swedish Apartments-and Measures for Mitigation2021Ingår i: Sustainability, E-ISSN 2071-1050, Vol. 13, nr 10, artikel-id 5446Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recently, there has been an increase in apartments with a large number of inhabitants, i.e., high residential density. This is partly due to a housing shortage in general but also increased migration, particularly in suburbs of major cities. This paper specifies issues that might be caused by high residential density by investigating the technical parameters influenced in Swedish apartments that are likely to have high residential density. Interviews with 11 employees at housing companies were conducted to identify issues that might be caused by high residential density. Furthermore, simulations were conducted based on extreme conditions described in the interviews to determine the impact on the energy use, indoor environmental quality, and moisture loads. In addition, the impact of measures to mitigate the identified issues was determined. Measures such as demand-controlled ventilation, increase of a constant ventilation rate, and moisture buffering are shown to reduce the risk for thermal discomfort, mold growth, and diminished indoor air quality; while still achieving a lower energy use than in a normally occupied apartment. The results of this study can be used by authorities to formulate incentives and/or recommendations for housing owners to implement measures to ensure good indoor environmental quality for all, irrespective of residential density conditions.

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  • 18.
    Abitbol, Tiffany
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Bioraffinaderi och energi.
    Impact of surface charge on CNC phase separation and rheology2017Ingår i: International Conference on Nanotechnology for Renewable Materials 2017, TAPPI Press , 2017, s. 64-71Konferensbidrag (Refereegranskat)
  • 19.
    Abitbol, Tiffany
    et al.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Alvarez-Asencio, Ruben
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Swerin, Agne
    KTH Royal Institute of Technology, Sweden.
    Nanocellulose-Based Hybrid Materials for UV Blocking and Mechanically Robust Barriers2020Ingår i: ACS Applied Bio Materials, E-ISSN 2576-6422, Vol. 3, nr 4, s. 2245-2254Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanocellulose (NC)-based hybrid coatings and films containing CeO2 and SiO2 nanoparticles (NPs) to impart UV screening and hardness properties, respectively, were prepared by solvent casting. The NC film-forming component (75 wt % of the overall solids) was composed entirely of cellulose nanocrystals (CNCs) or of CNCs combined with cellulose nanofibrils (CNFs). Zeta potential measurements indicated that the four NP types (CNC, CNF, CeO2, and SiO2) were stably dispersed in water and negatively charged at pH values between 6 and 9. The combination of NPs within this pH range ensured uniform formulations and homogeneous coatings and films, which blocked UV light, the extent of which depended on film thickness and CeO2 NP content, while maintaining good transparency in the visible spectrum (∼80%). The addition of a low amount of CNFs (1%) reduced the film hardness, but this effect was compensated by the addition of SiO2 NPs. Chiral nematic self-assembly was observed in the mixed NC film; however, this ordering was disrupted by the addition of the oxide NPs. The roughness of the hybrid coatings was reduced by the inclusion of oxide NPs into the NC matrix perhaps because the spherical oxide NPs were able to pack into the spaces between cellulose fibrils. We envision these hybrid coatings and films in barrier applications, photovoltaics, cosmetic formulations, such as sunscreens, and for the care and maintenance of wood and glass surfaces, or other surfaces that require a smooth, hard, and transparent finish and protection from UV damage.

  • 20.
    Abitbol, Tiffany
    et al.
    RISE Research Institutes of Sweden. EPFL, Switzerland.
    Kubat, Mikaela
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden.
    Kotov, Nikolay
    KTH Royal Institute of Technology, Sweden.
    Johnson, C Magnus
    KTH Royal Institute of Technology, Sweden.
    Nizamov, Rustem
    University of Turku, Finland.
    Nyberg, Mikael
    University of Turku, Finland.
    Miettunen, Kati
    University of Turku, Finland.
    Nordgren, Niklas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Guerreiro, Maria Pita
    RISE Research Institutes of Sweden.
    Isolation of Mixed Compositions of Cellulose Nanocrystals, Microcrystalline Cellulose, and Lignin Nanoparticles from Wood Pulps2023Ingår i: ACS Omega, E-ISSN 2470-1343, Vol. 8, nr 24, s. 21474-21484Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    From a circular economy perspective, one-pot strategies for the isolation of cellulose nanomaterials at a high yield and with multifunctional properties are attractive. Here, the effects of lignin content (bleached vs unbleached softwood kraft pulp) and sulfuric acid concentration on the properties of crystalline lignocellulose isolates and their films are explored. Hydrolysis at 58 wt % sulfuric acid resulted in both cellulose nanocrystals (CNCs) and microcrystalline cellulose at a relatively high yield (>55%), whereas hydrolysis at 64 wt % gave CNCs at a lower yield (<20%). CNCs from 58 wt % hydrolysis were more polydisperse and had a higher average aspect ratio (1.5-2×), a lower surface charge (2×), and a higher shear viscosity (100-1000×). Hydrolysis of unbleached pulp additionally yielded spherical nanoparticles (NPs) that were <50 nm in diameter and identified as lignin by nanoscale Fourier transform infrared spectroscopy and IR imaging. Chiral nematic self-organization was observed in films from CNCs isolated at 64 wt % but not from the more heterogeneous CNC qualities produced at 58 wt %. All films degraded to some extent under simulated sunlight trials, but these effects were less pronounced in lignin-NP-containing films, suggesting a protective feature, but the hemicellulose content and CNC crystallinity may be implicated as well. Finally, heterogeneous CNC compositions obtained at a high yield and with improved resource efficiency are suggested for specific nanocellulose uses, for instance, as thickeners or reinforcing fillers, representing a step toward the development of application-tailored CNC grades. © 2023 The Authors. 

  • 21.
    Abitbol, Tiffany
    et al.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Mijlkovic, Ana
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Jordbruk och livsmedel.
    Malafronte, Loredana
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Jordbruk och livsmedel.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Larsson, Per Tomas
    RISE Research Institutes of Sweden.
    Lopez-Sanchez, Patricia
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Jordbruk och livsmedel.
    Cellulose nanocrystal/low methoxyl pectin gels produced by internal ionotropic gelation.2021Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 260, artikel-id 117345Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The biotechnological applications of cellulose nanocrystals (CNCs) continue to grow due to their sustainable nature, impressive mechanical, rheological, and emulsifying properties, upscaled production capacity, and compatibility with other materials, such as protein and polysaccharides. In this study, hydrogels from CNCs and pectin, a plant cell wall polysaccharide broadly used in food and pharma, were produced by calcium ion-mediated internal ionotropic gelation (IG). In the absence of pectin, a minimum of 4 wt% CNC was needed to produce self-supporting gels by internal IG, whereas the addition of pectin at 0.5 wt% enabled hydrogel formation at CNC contents as low as 0.5 wt%. Experimental data indicate that CNCs and pectin interact to give robust and self-supporting hydrogels at solid contents below 2.5 %. Potential applications of these gels could be as carriers for controlled release, scaffolds for cell growth, or wherever else distinct and porous network morphologies are required.

  • 22.
    Abrahamsen, Rune
    et al.
    Moelven Limtre, Norway.
    Bjertnaes, Magne A.
    Sweco, Norway.
    Bouillot, Jacques
    Eiffage, France.
    Brank, Bostjan
    University of Ljubljana, Slovenia.
    Cabaton, Lionel
    Arbonis, France.
    Crocetti, Roberto
    Moelven, Sweden.
    Flamand, Olivier
    CSTB, France.
    Garains, Fabien
    Eiffage, France.
    Gavric, Igor
    InnoRenew, Slovenia.
    Germain, Olivier
    Galeo, France.
    Hahusseau, Ludwig
    Eiffage, France.
    Hameury, Stephane
    CSTB, France.
    Johansson, Marie
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Johansson, Thomas
    Moelven, Sweden.
    Ao, Wai Kei
    University of Exeter, United Kingdom.
    Kurent, Blaz
    University of Ljubljana, Slovenia.
    Landel, Pierre
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Linderholt, Andreas
    Linnaeus University, Sweden.
    Malo, Kjell
    NTNU Norwegian University of Science and Technology, Norway.
    Manthey, Manuel
    CSTB, France.
    Nåvik, Petter
    Sweco, Norway.
    Pavic, Alex
    University of Exeter, United Kingdom.
    Perez, Fernando
    Smith and Wallwork, United Kingdom.
    Rönnquist, Anders
    NTNU Norwegian University of Science and Technology, Norway.
    Stamatopoulos, Haris
    NTNU Norwegian University of Science and Technology, Norway.
    Sustersic, Iztok
    InnoRenew, Slovenia.
    Tulebekova, Salue
    NTNU Norwegian University of Science and Technology, Norway.
    Dynamic Response of Tall Timber Buildings Under Service Load: The DynaTTB Research Program2020Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wind-induced dynamic excitation is becoming a governing design action determin-ing size and shape of modern Tall Timber Buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway – i.e. vibration serviceability failure. Although some TTBs have been instrumented and meas-ured to estimate their key dynamic properties (natural frequencies and damping), no systematic evaluation of dynamic performance pertinent to wind loading has been performed for the new and evolving construction technology used in TTBs. The DynaTTB project, funded by the Forest Value research program, mixes on site measurements on existing buildings excited by heavy shakers, for identification of the structural system, with laboratory identification of building elements mechanical features coupled with numerical modelling of timber structures. The goal is to identify and quantify the causes of vibration energy dissipation in modern TTBs and pro-vide key elements to FE modelers.

    The first building, from a list of 8, was modelled and tested at full scale in December 2019. Some results are presented in this paper. Four other buildings will be modelled and tested in spring 2020.

  • 23.
    Abrahamsen, Rune
    et al.
    Moelven Limtre, Norway.
    Johansson, Marie
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Tulebekova, Saule
    NTNU, Norway.
    DYNAMIC RESPONSE OF TALL TIMBER BUILDINGS UNDER SERVICE LOAD – RESULTS FROM THE DYNATTB RESEARCH PROGRAM2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wind-induced dynamic excitation is a governing design action determining size and shape of modern Tall Timber Buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway, i.e. vibration serviceability problem. Although some TTBs have been instrumented and measured to estimate their key dynamic properties (eigenfrequencies, mode shapes and damping), no systematic evaluation of dynamic performance pertinent to wind loading had been performed for the new and evolving construction technologies used in TTBs. The DynaTTB project, funded by the ForestValue research program, mixed on site measurements on existing buildings excited by mass inertia shakers (forced vibration) and/or the wind loads (ambient vibration), for identification of the structural system, with laboratory identification of building elements mechanical features, coupled with numerical modelling of timber structures. The goal is to identify and quantify the causes of vibration energy dissipation in modern TTBs and provide key elements to finite element models. This paper presents an overview of the results of the project and the proposed Guidelines for design of TTBs in relation to their dynamic properties.

  • 24.
    Abrahamsson, Camilla
    et al.
    Lund University, Sweden.
    Rissler, Jenny
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. Lund University, Sweden.
    Hedmer, Maria
    Lund University, Sweden.
    KÃ¥redal, Monica
    Lund University, Sweden.
    Isaxon, Christina
    Lund University, Sweden.
    77 Aerosolized Particulate Matter from Fragmentation of Carbon Nanotube-Enhanced Concrete2023Ingår i: Annals of Work Exposures and Health, Vol. 67, nr Supplement_1, s. i94-i95Artikel i tidskrift (Övrigt vetenskapligt)
  • 25.
    Abrahamsson, Henrik
    et al.
    RISE - Research Institutes of Sweden, ICT, SICS.
    Ben Abdesslem, Fehmi
    RISE - Research Institutes of Sweden, ICT, SICS.
    Ahlgren, Bengt
    RISE - Research Institutes of Sweden, ICT, SICS.
    Björkman, Mats
    Mälardalen University, Sweden.
    Brunstrom, Anna
    Karlstad University, Sweden.
    Marsh, Ian
    RISE - Research Institutes of Sweden, ICT, SICS.
    Selecting Operator in 3G/4G Networks for Time-Critical C-ITS Applications2018Konferensbidrag (Refereegranskat)
  • 26.
    Abrahamsson, Henrik
    et al.
    RISE - Research Institutes of Sweden, ICT, SICS.
    Ben Abdesslem, Fehmi
    RISE - Research Institutes of Sweden, ICT, SICS.
    Ahlgren, Bengt
    RISE - Research Institutes of Sweden, ICT, SICS.
    Brunstrom, Anna
    Karlstad University, Sweden.
    Marsh, Ian
    RISE - Research Institutes of Sweden, ICT, SICS.
    Björkman, Mats
    Mälardalen University, Sweden.
    Connected Vehicles in Cellular Networks: Multi-access versus Single-access Performance2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Connected vehicles can make roads traffic safer andmore efficient, but require the mobile networks to handle timecriticalapplications. Using the MONROE mobile broadbandmeasurement testbed we conduct a multi-access measurementstudy on buses. The objective is to understand what networkperformance connected vehicles can expect in today’s mobilenetworks, in terms of transaction times and availability. The goalis also to understand to what extent access to several operatorsin parallel can improve communication performance.In our measurement experiments we repeatedly transfer warningmessages from moving buses to a stationary server. Wetriplicate the messages and always perform three transactionsin parallel over three different cellular operators. This creates adataset with which we can compare the operators in an objectiveway and with which we can study the potential for multi-access.In this paper we use the triple-access dataset to evaluate singleaccessselection strategies, where one operator is chosen for eachtransaction. We show that if we have access to three operatorsand for each transaction choose the operator with best accesstechnology and best signal quality then we can significantlyimprove availability and transaction times compared to theindividual operators. The median transaction time improves with6% compared to the best single operator and with 61% comparedto the worst single operator. The 90-percentile transaction timeimproves with 23% compared to the best single operator andwith 65% compared to the worst single operator.

  • 27.
    Abualhoul, Mohammad Y.
    et al.
    Lund University, Sweden.
    Svenmarker, Pontus
    Lund University, Sweden.
    Wang, Qin
    RISE., Swedish ICT, Acreo.
    Andersson, Jan Y.
    RISE., Swedish ICT, Acreo.
    Johansson, Anders J.
    Lund University, Sweden.
    Free space optical link for biomedical applications2012Ingår i: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, 2012, s. 1667-1670, artikel-id 6346267Konferensbidrag (Refereegranskat)
    Abstract [en]

    Free space optics is an interesting alternative for telemetry with medical implants, due to the high data bandwidths available at optical frequencies. Especially implanted brain-computer interfaces gives rise to large data sets that needs to be transmitted transcutaneous. In this paper we show that it is possible to establish such a link at near-IR wavelengths using a modulated reflector in the implant, thus keeping the laser and the detector on the outside. In addition, we show that it will not only work on short, i.e. touch, distances but also at larger distances, in the range of a meter. We have used an electro absorption modulator to modulate the reflection of an external laser source back towards an external detector. The only part of this system that needs to be implanted is the modulator and drive electronics. The study has been done both by Monte-Carlo simulations of a multi-layer model of a rat skull, and with an experiment demonstrating the feasibility of the link when transmitted through biological tissue. The results show that it is possible to establish a transcutaneous link with an external laser source and light detector, and an internal modulated reflector.

  • 28.
    Abugabbara, Marwan
    et al.
    Lund University, Sweden.
    Gehlin, Signhild
    Swedish Geoenergy Center, Sweden.
    Lindhe, Jonas
    Lund University, Sweden; Alfa Laval Corporate AB, Sweden.
    Axell, Monica
    RISE Research Institutes of Sweden, Samhällsbyggnad, Energi och resurser.
    Holm, Daniel
    Vasakronan AB, Sweden.
    Johansson, Hans
    Umeå ProjektEnergi AB, Sweden.
    Larsson, Martin
    RISE Research Institutes of Sweden, Samhällsbyggnad, Energi och resurser.
    Mattsson, Annika
    Granitor Properties, Sweden.
    Näslund, Ulf
    Vasakronan AB, Sweden.
    Puttige, Anjan
    Umeå University, Sweden.
    Berglöf, Klas
    ClimaCheck Sweden AB, Sweden.
    Claesson, Johan
    Lund University, Sweden.
    Hofmeister, Morten
    VIA University College, Denmark.
    Janson, Ulla
    Lund University, Sweden.
    Jensen, Axel
    Region Midtjylland,Denmark; Aalborg University, Denmark.
    Termén, Jens
    Energy Machines, Sweden.
    Javed, Saqib
    Lund University, Sweden.
    How to develop fifth-generation district heating and cooling in Sweden?: Application review and best practices proposed by middle agents2023Ingår i: Energy Reports, E-ISSN 2352-4847, Vol. 9, s. 4971-4983Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sweden has an ambitious plan to fully decarbonise district heating by 2030 and to contribute with negative emissions of greenhouse gases in 2050. The vagaries of the energy market associated with climate, political, and social changes entail cross-sectoral integration that can fulfill these national targets. Fifth-generation district heating and cooling (5GDHC) is a relatively new concept of district energy systems that features a simultaneous supply of heating and cooling using power-to-heat technologies. This paper presents best practices for developing 5GDHC systems in Sweden to reach a consensus view on these systems among all stakeholders. A mixed-method combining best practice and roadmapping workshops has been used to disseminate mixed knowledge and experience from middle agents representing industry professionals and practitioners. Four successful implementations of 5GDHC systems are demonstrated and the important learned lessons are shared. The best practices are outlined for system planning, system modeling and simulation, prevailing business models for energy communities, and system monitoring. A roadmap from the middle agents’ point of view is composed and can be utilised to establish industry standards and common regulatory frameworks. © 2023 The Author(s)

  • 29. Acciaro, R.
    et al.
    Aulin, C.
    RISE., Innventia.
    Wågberg, L.
    Lindström, T.
    RISE., Innventia.
    Claesson, P.M.
    Varga, I.
    Investigation of the formation structure and release characteristics of self-assembled composite films of cellulose nanofibrils and temperature responsive microgels2011Ingår i: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, nr 4, s. 1369-1377Artikel i tidskrift (Refereegranskat)
  • 30.
    Achtel, Christian
    et al.
    Friedrich Schiller University of Jena, Germany.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF. Friedrich Schiller University of Jena, Germany.
    Kosan, Birgit
    TITK Thuringian Institute of Textile and Plastics Research, Germany.
    Seoud, Omar. A.El
    University of São Paulo, Brazil.
    Heinze, Thomas
    Friedrich Schiller University of Jena, Germany.
    Dissolution capacity of novel cellulose solvents based on triethyloctylammonium chloride2017Ingår i: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 218, nr 21, artikel-id 1700208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dissolution of cellulose from various sources (microcrystalline cellulose and different dissolving grade pulp fibers) is investigated in solvent systems based on triethyl(n-octyl)ammonium chloride (N2228Cl). Clear cellulose solutions are obtained with N2228Cl in a variety of solvents, e.g., dimethyl sulfoxide, N,N-dimethylacetamide, and acetone. It is possible to prepare clear cellulose solutions from pulp fibers with concentrations up to 15 wt%. However, it is found that the cellulose is degraded, especially when neat (i.e., molten) N2228Cl is used as a solvent. The present work includes comprehensive rheological characterization of the cellulose solutions, both with shear and extensional rheology. In most cases, the viscosity values are low (complex viscosities below 100 Pa s for 5–10 wt% dissolved cellulose), and the solutions show more Newtonian than viscoelastic behavior. 

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  • 31.
    Adolfsson, Erik
    RISE - Research Institutes of Sweden, Material och produktion, IVF, Keramer.
    Zirconia in applications with bone contact2016Konferensbidrag (Övrigt vetenskapligt)
  • 32.
    Adolfsson, Erik
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Lyckfeldt, Ola
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Johansson, Emil
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Visible-Light Curable Ceramic Suspensions for Additive Manufacturing of Dense Ceramic Parts2016Konferensbidrag (Övrigt vetenskapligt)
  • 33.
    Adolfsson, Erik
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Shen, James Zhijian
    Stockholm University, Sweden.
    Defect Minimization in Prosthetic Ceramics2014Ingår i: Advanced Ceramics for Dentistry, Elsevier Inc. , 2014, s. 359-373Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    The mechanical reliability and aesthetic appearance of ceramic dental prostheses are strongly influenced by the presence of defects. When several processes are used during fabrication of ceramic dental prostheses, additional defects are unavoidably introduced in each process step; these are in addition to the ones that already exist in raw materials. To avoid the degeneration of material performance by the accumulated defect population, process optimization is needed to minimize the defects introduced. Standardized mechanical evaluations are usually performed on samples with carefully prepared surfaces in order to minimize the influence from the defects usually induced by fabrication processes. The results from such mechanical evaluation indicate the strength level that is achievable by the material with the given population of bulk defects. In order to avoid a reduction in the performance of the ceramic material by the additional defects normally induced by the fabrication process, it must be understood how these defects are introduced, and solutions must be found to reduce their size and frequency through modifications of the material and processes. The aim of this chapter is to elucidate the sources of defects that are common for ceramic dental prostheses and to determine how to minimize them.

  • 34.
    Adolfsson, Erik
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Shen, James Zhijian
    Stockholm University, Sweden.
    Effects of granule density on strength and granule related defects in zirconia2012Ingår i: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 32, nr 11, s. 2653-2659Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A suspension of zirconia powder (TZ3YSE) with a solids loading of 50. vol% was prepared by ball milling. Binders were added and some of the suspension was diluted to 40, 30 and 20. vol% before freeze granulation was performed. A spray dried material (TZ3YSEB) was used as a reference. The pore size distribution of the different granules was evaluated and from the microstructure it was shown that inhomogeneities were present in both the freeze granulated as well as in the spray dried granules. In addition, the density, microstructure as well as the strength of sintered materials prepared from the granules were studied. The results showed that a high green density or sintered density was not sufficient in order to achieve a high strength material. It was further shown that the strength was significantly influenced by the granule density and not by the inhomogeneities found in the granules.

  • 35.
    Adolfsson, Erik
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Tönnäng, Lenny
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    The effect of softmachining parameters on the mechanical strength of zirconia2015Konferensbidrag (Övrigt vetenskapligt)
  • 36.
    Adolfsson, Erik
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Venturini, Francesca
    ZHAW School of Engineering, Switzerland.
    Schönherr, Veit
    ZHAW School of Engineering, Switzerland .
    Rey, Julien
    ZHAW School of Engineering, Switzerland .
    Characterization oflight-gas interaction in strongly-scattering nanoporous materials and itsimplications for tunable diode laser absorption spectroscopy2016Ingår i: Applied Physics B: Lasers and Optics, 2016, Vol. 123, s. 123-136Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Through the confinement of gas in nanoporous materials, it is possible to significantly increase the path length for light–gas interaction. This enables the observation of much stronger absorption features for the confined gas molecules. In this work, we systematically characterized a variety of disordered strongly scattering ZrO2 and Al2O3 nanoporous ceramic materials to exploit the potential of gas in scattering media absorption spectroscopy. As a result, we identified a material with an unprecedented performance in terms of optical path length enhancement. In ZrO2 with thicknesses above 6 mm, the path enhancement exceeds 1000. The results obtained with near-infrared absorption spectroscopy on oxygen were validated by time-of-flight measurements at 700 nm, thus demonstrating their robustness. Finally, we report quantitative oxygen concentration measurement using nanoporous materials as miniaturized random-scattering multipass cell with an extremely simple and low-cost setup.

  • 37.
    Adomat, M
    et al.
    RISE., Swedish ICT, Acreo.
    Fonjallaz, P-Y
    Olofsson, F
    Step-wise tunability of a DBR laser with a superimposed fiber grating external cavity2000Ingår i: Proceedings of OFC 2000 - Optical Fiber Communication Conference, 196, (2000)., 2000, Vol. 1, s. 196-198Konferensbidrag (Refereegranskat)
    Abstract [en]

    A DBR laser is step-wise tunable thanks to a superimposed fiber grating external cavity. The stability against tuning current variations in the DBR is excellent. Single-mode operation is achieved with SMSR better than 30 dB.

  • 38.
    Aftab, Muhammad Usman
    et al.
    National University of Sciences and Technology, Pakistan.
    Hussain, Mehdi
    National University of Sciences and Technology, Pakistan.
    Lindgren, Anders
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Ghafoor, Abdul
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Towards A Distributed Ledger Based Verifiable Trusted Protocol for VANET2021Ingår i: 2021 International Conference on Digital Futures and Transformative Technologies, ICoDT2 2021, Institute of Electrical and Electronics Engineers Inc. , 2021Konferensbidrag (Refereegranskat)
    Abstract [en]

    To ensure traffic safety and proper operation of vehicular networks, safety messages or beacons are periodically broadcasted in Vehicular Adhoc Networks (VANETs) to neighboring nodes and road side units (RSU). Thus, authenticity and integrity of received messages along with the trust in source nodes is crucial and highly required in applications where a failure can result in life-threatening situations. Several digital signature based approaches have been described in literature to achieve the authenticity of these messages. In these schemes, scenarios having high level of vehicle density are handled by RSU where aggregated signature verification is done. However, most of these schemes are centralized and PKI based where our goal is to develop a decentralized dynamic system. Along with authenticity and integrity, trust management plays an important role in VANETs which enables ways for secure and verified communication. A number of trust management models have been proposed but it is still an ongoing matter of interest, similarly authentication which is a vital security service to have during communication is not mostly present in the literature work related to trust management systems. This paper proposes a secure and publicly verifiable communication scheme for VANET which achieves source authentication, message authentication, non repudiation, integrity and public verifiability. All of these are achieved through digital signatures, Hash Message Authentication Code (HMAC) technique and logging mechanism which is aided by blockchain technology.

  • 39.
    Agirre, Joseba A.
    et al.
    MGEP, Spain.
    Etxeberria, L.
    MGEP, Spain.
    Barbosa, R.
    University of Coimbra, Portugal.
    Basagiannis, S.
    United Technologies Research Centre, Ireland.
    Giantamidis, G.
    United Technologies Research Centre, Ireland.
    Bauer, Thomas
    Fraunhofer, Germany.
    Ferrari, E.
    Rulex Innovation Labs, Italy.
    Labayen Esnaola, M.
    CAF SIGNALLING, Spain.
    Orani, V.
    CNR-IEIIT, Italy.
    Öberg, J.
    KTH Royal Institute of Technology, Sweden.
    Pereira, David
    CISTER/ISEP, Portugal.
    Proenca, Jose
    CISTER/ISEP, Portugal.
    Schlick, Rupert
    AIT Austrian Institute of Technology, Austria.
    Smrcka, Ales
    Brno University of Technology, Czech Republic.
    Tiberti, W.
    University of L’Aquila, Italy.
    Tonetta, S.
    Fondazione Bruno Kessler, Italy.
    Bozzano, M.
    Fondazione Bruno Kessler, Italy.
    Yazici, A.
    Eskisehir Osmangazi University, Turkey.
    Sangchoolie, Behrooz
    RISE Research Institutes of Sweden, Säkerhet och transport, Elektrifiering och pålitlighet.
    The VALU3S ECSEL project: Verification and validation of automated systems safety and security2021Ingår i: Microprocessors and microsystems, ISSN 0141-9331, E-ISSN 1872-9436, Vol. 87, artikel-id 104349Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Manufacturers of automated systems and their components have been allocating an enormous amount of time and effort in R&D activities, which led to the availability of prototypes demonstrating new capabilities as well as the introduction of such systems to the market within different domains. Manufacturers need to make sure that the systems function in the intended way and according to specifications. This is not a trivial task as system complexity rises dramatically the more integrated and interconnected these systems become with the addition of automated functionality and features to them. This effort translates into an overhead on the V&V (verification and validation) process making it time-consuming and costly. In this paper, we present VALU3S, an ECSEL JU (joint undertaking) project that aims to evaluate the state-of-the-art V&V methods and tools, and design a multi-domain framework to create a clear structure around the components and elements needed to conduct the V&V process. The main expected benefit of the framework is to reduce time and cost needed to verify and validate automated systems with respect to safety, cyber-security, and privacy requirements. This is done through identification and classification of evaluation methods, tools, environments and concepts for V&V of automated systems with respect to the mentioned requirements. VALU3S will provide guidelines to the V&V community including engineers and researchers on how the V&V of automated systems could be improved considering the cost, time and effort of conducting V&V processes. To this end, VALU3S brings together a consortium with partners from 10 different countries, amounting to a mix of 25 industrial partners, 6 leading research institutes, and 10 universities to reach the project goal.

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  • 40.
    Agirre, Joseba A
    et al.
    Mondragon University, Spain.
    Yazici, Ahmet
    Eskisehir Osmangazi University, Turkey.
    Di Blasio, Katia
    Intecs Solutions S.p.a., Italy.
    De la Vara, Jose Luis
    University of Castilla-La Mancha, Spain.
    Sangchoolie, Behrooz
    RISE Research Institutes of Sweden, Säkerhet och transport, Elektrifiering och pålitlighet.
    Yayan, Ugur
    Inovasyon Muhendislik Ltd. Sti, Turkey.
    Barbosa, Raul
    University of Coimbra, Portugal.
    Etxeberria, Leire
    Mondragon University, Spain.
    Nazaria, Massimo
    Fondazione Bruno Kessler, Italy.
    Karaca, Mustafa
    Inovasyon Muhendislik Ltd. Sti, Turkey.
    Multidimensional Framework for Characterizing Verification and Validation of Automated Systems2022Ingår i: 18th European dependable computing conference (EDCC 2022), 2022Konferensbidrag (Refereegranskat)
    Abstract [en]

    Verification and Validation (V&V) of automated systems is becoming more costly and time-consuming because of the increasing size and complexity of these systems. Moreover, V&V of these systems can be hindered if the methods and processes are not properly described, analysed, and selected. It is essential that practitioners use suitable V&V methods and enact adequate V&V processes to confirm that these systems work as intended and in a cost-effective manner. Previous works have created different taxonomies and models considering different aspects of V&V that can be used to classify V&V methods and tools. The aim of this work is to provide a broad, comprehensive and a easy to use framework that addresses characterisation needs, rather than focusing on individual aspects of V&V methods and processes.To this end, in this paper, we present a multi-domain and multi-dimensional framework to characterize and classify V&V methods and tools in a structured way. The framework considers a comprehensive characterization of different relevant aspects of V&V. A web-based repository has been implemented on the basis of the framework, as an example of use, in order to collect information about the application of V&V methods and tools. This way, practitioners and researchers can easily learn about and identify suitable V&V processes.

  • 41. Agnihotri, S.
    et al.
    Johnsen, I.A.
    RISE., Innventia, PFI – Paper and Fiber Research Institute.
    Moe, S.
    Gregersen, Ø.
    More selective biorefining of softwood by combined hot water and ethanol organosolv pretreatment2011Konferensbidrag (Refereegranskat)
  • 42.
    Agnihotri, Swarnima
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Johnsen, Ingvild A.
    RISE., Innventia, PFI – Paper and Fiber Research Institute.
    Böe, Maren S.
    NTNU Norwegian University of Science and Technology, Norway.
    Öyaas, Karin
    RISE., Innventia, PFI – Paper and Fiber Research Institute.
    Moe, Størker
    NTNU Norwegian University of Science and Technology, Norway.
    Ethanol organosolv pretreatment of softwood (Picea abies) and sugarcane bagasse for biofuel and biorefinery applications2015Ingår i: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 49, nr 5, s. 881-896Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethanol derived from biomass has the potential to be a renewable transportation fuel that can replace gasoline. This work was carried out to establish an optimized ethanol organosolv pretreatment of Norway spruce (Picea abies) for bioethanol production (63 wt% EtOH, pH ~3.5 in aqueous phase, 170–240 °C, 90 min) utilizing hydrolytic enzymes in the saccharification step. To test the generality of the method, a series of ethanol organosolv pretreatments were also performed on sugarcane bagasse (50 wt% EtOH, pH ~3.5 in aqueous phase, 155–210 °C, 90–120 min). The degree of delignification increased with increasing temperature during pretreatment, and the fastest increase was observed with sugarcane bagasse. The pretreatments were carried out in a batch mode. The maximum degree of delignification of ~65 % was reached at ~235 °C for Norway spruce, while sugarcane bagasse reached ~80 % at ~210 °C. Cellulose was subjected to degradation (5–10 % points) at these temperatures. Subsequent enzymatic hydrolysis (30 FPU/g cellulose, 32 pNPGU/g cellulose, 50 °C, 48 h) of ethanol organosolv-pretreated biomass achieved complete conversion for both raw materials at the highest degrees of delignification.

  • 43. Ahlberg, C.
    et al.
    Lundell, F.
    Söderberg, L. Daniel
    RISE., Innventia.
    Self-organization of fibers in a suspension between two counter-rotating discs2009Ingår i: Proceedings of the ASME Fluids Engineering Division Summer Conference 2009, 2009, Vol. 1, nr PART A, s. 585-592Konferensbidrag (Refereegranskat)
    Abstract [en]

    The behavior of fibers suspended in a flow between two flat counter-rotating discs has been studied experimentally. Captured images of the fibers in the flow were analyzed by steerable filters, to extract positions and orientations of the fibers. Experiments were performed for gaps between the discs of less than one fiber length, and for equal absolute values of the angular velocities for the discs. The length-to-diameter ratio of the fibers was approximately 14. During certain conditions, the fibers organized themselves in a distinct manner, which we will denote as fiber trains, in which three or more fibers are aligned next to each other, at the same radial position, with a short fiber-to-fiber distance. The direction of the individual fibers is radial and the direction of the whole train is tangential. Trains containing more than 60 fibers have been observed and are quite impressing.

  • 44.
    Ahlgren, Bengt
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Claesson, Åsa
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Honfi, Daniel
    RISE Research Institutes of Sweden. Ramböll, Sweden.
    Kardeby, Victor
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Karoumi, Raid
    KTH Royal Institute of Technology, Sweden.
    Leander, John
    KTH Royal Institute of Technology, Sweden.
    Digitaliseringens möjligheter och utmaningar inom förvaltning och underhållsplanering av broar: Förstudie2020Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Rapporten behandlar digitalisering – att införa ny digital teknik – i förvaltningsverksamheten av broar. Omfattningen är en förstudie med syftet att identifiera behovet av framtida forskning för en långsiktig utveckling av broförvaltningen. En grundläggande ansats var att en digitalisering ska minska behovet av kostsamma underhållsåtgärder men bibehålla en hög säkerhet för våra broar. Projektets mål var att samla information om digitala informationsmodeller som skapas under investeringsskedet, utvärdera överlämningen av digitala modeller till förvaltningsskedet, och värdera den eventuella nyttan med digital informationsinsamling för tillståndsbedömning och underhållsplanering. En viktig del av detta var beskrivningen av dagens förvaltningssystem och hur det skulle kunna utvecklas. Studierna har bedrivits genom en enkätundersökning med respondenter från konsultfirmor aktiva inom broprojektering, intervjuer med tekniska experter och litteratursökningar. Resultatet visar att projekteringen av broar idag huvudsakligen görs genom byggnads-informationsmodellering (BIM). Inriktningen är mot byggskedet där samordning och kommunikation bedöms vara de största nyttorna. Överlämningen till förvaltningen består dock av relationsritningar i formen av enkla ritningsfiler. Trots att Trafikverkets strategi för BIM beskriver att en informationsmodell bör leva kvar under hela brons livslängd, finns det tveksamheter huruvida en modell från projekteringen är lämplig som förvaltningsmodell. Istället lyfts andra metoder fram för att skapa en modell av det byggda utförandet. Till exempel optiska metoder för skanning och fotogrammetri. Förvaltningssystemen bör utvecklas med funktioner för att lagra och tillgängliggöra stora mängder digital information från sensorer maskinella inspektioner. Syftet är att minska osäkerheterna i det byggda utförandet och graden av nedbrytning, för att slutligen skapa ett bättre underlag för beslut om åtgärder. Ett framtida scenario är en digital tvilling som speglar den verkliga konstruktionen och uppdateras kontinuerligt genom sensordata. Gällande hårdvara för mätningar behöver sensorer och system utvecklas med avseende på energiförbrukning, energiskördning och underhållsåtgärder, t.ex. genom kombinationer av utbytbara komponenter med kort livslängd och andra delar med lång livslängd. Fiberoptiska sensorer visar på lovande egenskaper men utveckling behövs för att göra dem mer kostnadseffektiva i relation till konventionella sensorer.

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  • 45.
    Ahlgren, Bengt
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Grinnemo, Karl-Johan
    Evaluation of the ZQTRTT latency-aware multipath scheduler2020Konferensbidrag (Refereegranskat)
  • 46.
    Ahlgren, Bengt
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Grinnemo, Karl-Johan
    Karlstad University, Sweden.
    ZQTRTT: A Multipath Scheduler for Heterogeneous Traffic in ICNs Based on Zero Queueing Time Ratio2022Ingår i: ICN 2022 - Proceedings of the 2022 9th ACM Conference on Information-Centric Networking, Association for Computing Machinery, Inc , 2022Konferensbidrag (Refereegranskat)
    Abstract [en]

    Information-centric networks (ICNs) intrinsically support multipath transfer and thus have been seen as an exciting paradigm for IoT and edge computing, not least in the context of 5G mobile networks. One key to ICN's success in these and other networks that have to support a diverse set of services over a heterogeneous network infrastructure is to schedule traffic over the available network paths efficiently. This paper presents and evaluates ZQTRTT, a multipath scheduling scheme for ICN that load balances bulk traffic over available network paths and schedules latency-sensitive, non-bulk traffic to reduce its transfer delay. A new metric called zero queueing time (ZQT) ratio estimates path load and is used to compute forwarding fractions for load balancing. In particular, the paper shows through a simulation campaign that ZQTRTT can accommodate the demands of both latency-sensitive and-insensitive traffic as well as evenly distribute traffic over available network paths. 

  • 47.
    Ahlgren, Bengt
    et al.
    RISE - Research Institutes of Sweden, ICT, SICS.
    Grinnemo, Karl-Johan
    Karlstad University, Sweden.
    Abrahamsson, Henrik
    RISE - Research Institutes of Sweden, ICT, SICS.
    Brunstrom, Anna
    Karlstad University, Sweden.
    Hurtig, Per
    Karlstad University, Sweden.
    Latency-aware Multipath Scheduling in Information-centric Networks2019Ingår i: Proceedings of the 15th Swedish National Computer Networking Workshop (SNCNW), 2019Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    We present the latency-aware multipath scheduler ZQTRTT that takes advantage of the multipath opportunities in information-centric networking. The goal of the scheduler is to use the (single) lowest latency path for transaction-oriented flows, and use multiple paths for bulk data flows. A new estimator called zero queue time ratio is used for scheduling over multiple paths. The objective is to distribute the flow over the paths so that the zero queue time ratio is equal on the paths, that is, so that each path is ‘pushed’ equally hard by the flow without creating unwanted queueing. We make an initial evaluation using simulation that shows that the scheduler meets our objectives.

  • 48.
    Ahlroth, Mikael
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Bialik, Marta
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. RISE., Innventia.
    Jansson, Mikael
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. Andritz, Sweden.
    Rosenqvist, Kristian
    ÅF, Sweden.
    Bark and wood powder firing in the recovery boiler for maximum power generation2017Ingår i: International chemical recovery conference, May 24-26, 2017, Halifax, Canada, PAPTAC , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    The effect of co-firing bark or wood powder in a recovery boiler is studied. The effect of increased NPEs in the liquor and lime cycles, the FMT and sticky dust and the smelt composition is assessed by using simulation tools. The results indicate that generating an additional 22-39% HP steam for power production by firing wood powder in the recovery boiler is a viable option, if Cl and K are purged from the ESP dust by a treatment unit. The smelt is enriched with the same proportion of NPEs as the as-fired liquor.

  • 49.
    Ahlroth, Mikael
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Bialik, Marta
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Jensen, Anna
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Hydrothermal carbonisation of effluent sludge2017Ingår i: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017: NWBC 2017, Stockholm: RISE Bioekonomi , 2017, s. 156-158Konferensbidrag (Refereegranskat)
    Abstract [en]

    Research was carried out to investigate hydrothermal carbonisation (HTC) treatment of different effluent sludges from the pulp and paper industry in a Parr-reactor. Sludge samples were evaluated from a thermomechanical paper (TMP) mill and a kraft market pulp mill (NSWBK). The issues studied included HTC treatment time; addition of acid and alkali; dewatering properties of the resulting slurry; and non-process element (NPE) concentration in the original sludge, the filtrate and the filter cake. It was found that HTC improved the fuel quality. Alkali metals were depleted in TMP and NSWBK sludge and in both cases, the sludge was easier to dewater. The yield was better for TMP than NSWBK sludge and the yield losses had a negative impact on the NSWBK sludge. TMP sludge was already a viable boiler fuel and the treatment improved the fuel qualities even more. The HTC treatment of the NSWBK sludge resulted in lower chlorine and potassium, with lower fuel-nitrogen resulting in lower nitrous oxide. Although HTC treatment improved the low heating value of the sludge, this was counteracted by yield loss. Compared with untreated NSWBK, the overall energy impact was negative. HTC treatment offered mixed opportunities from the viewpoint of the recovery cycle.

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  • 50.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Material och produktion, KIMAB.
    Aluminium i betong - Litteraturstudie och experimentella försök2012Rapport (Refereegranskat)
    Abstract [sv]

    I dagens byggprojekt används en mängd olika material för att bygga konstruktioner. Det förekommer att komponenter av aluminium gjuts in i betong vilket medför en risk att täckskiktet spricker p.g.a. korrosionsprodukternas stora volym. Därför är det viktigt att klargöra vilka korrosionsegenskaper aluminium har ingjuten i betong.

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