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  • Eriksson, Mimmi
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. KTH Royal Institute of Technology, Sweden; CR Colloidal Resource AB, Sweden.
    Claesson, Per M.
    KTH Royal Institute of Technology, Sweden.
    Järn, Mikael
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Wallqvist, Viveca
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Tuominen, Mikko
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Kappl, Michael
    Nordtreat Oy, Finland.
    Teisala, Hannu
    Max Planck Institute, Germany; Amcor Flexibles Valkeakoski Oy, Finland.
    Vollmer, Doris
    Max Planck Institute, Germany.
    Schoelkopf, Joachim
    Omya International AG, Switzerland.
    Gane, Patrick A.C.
    University of Belgrade, Serbia; Aalto University, Finland.
    Mäkelä, Jyrki M.
    Tampere University, Finland.
    Swerin, Agne
    KTH Royal Institute of Technology, Sweden; Karlstad University, Sweden.
    Effects of Gas Layer Thickness on Capillary Interactions at Superhydrophobic Surfaces2024In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 40, no 9, p. 4801-4810Article in journal (Refereed)
    Abstract [en]

    Strongly attractive forces act between superhydrophobic surfaces across water due to the formation of a bridging gas capillary. Upon separation, the attraction can range up to tens of micrometers as the gas capillary grows, while gas molecules accumulate in the capillary. We argue that most of these molecules come from the pre-existing gaseous layer found at and within the superhydrophobic coating. In this study, we investigate how the capillary size and the resulting capillary forces are affected by the thickness of the gaseous layer. To this end, we prepared superhydrophobic coatings with different thicknesses by utilizing different numbers of coating cycles of a liquid flame spraying technique. Laser scanning confocal microscopy confirmed an increase in gas layer thickness with an increasing number of coating cycles. Force measurements between such coatings and a hydrophobic colloidal probe revealed attractive forces caused by bridging gas capillaries, and both the capillary size and the range of attraction increased with increasing thickness of the pre-existing gas layer. Hence, our data suggest that the amount of available gas at and in the superhydrophobic coating determines the force range and capillary growth. © 2024 The Authors.

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  • Bertilsson, I.
    et al.
    Region Västra Götaland, Sweden; Lund University, Sweden.
    Melin, Jeanette
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Brogårdh, C.
    Lund University, Sweden.
    Opheim, A.
    Region Västra Götaland, Sweden; University of Gothenburg, Sweden.
    Gyllensten, A. L.
    Lund University, Sweden.
    Björksell, E.
    Region Kronoberg, Sweden.
    Sjödahl Hammarlund, C.
    Lund University, Sweden.
    Measurement properties of the Body Awareness Scale Movement Quality (BAS MQ) in persons on the autism spectrum: A preliminary Rasch analysis2024In: Journal of Bodywork & Movement Therapies, ISSN 1360-8592, E-ISSN 1532-9283, Vol. 38, p. 464-473Article in journal (Refereed)
    Abstract [en]

    Background: Persons on the autism spectrum exhibit poorer body awareness than neurotypical persons. Since movement quality may be regarded as an expression of body awareness, assessment of movement quality is important. Sound assessments of measurement properties are essential if reliable decisions about body awareness interventions for persons on the autism spectrum are to be made, but there is insufficient research. Objective: To assess measurement properties of the Body Awareness Scale Movement Quality (BAS MQ) in an autism and a neurotypical reference group. Methods: Persons on the autism spectrum (n=108) and neurotypical references (n=32) were included. All were assessed with BAS MQ. Data were analyzed according to the Rasch model. Results: BAS MQ was found to have acceptable unidimensionality, supported by the fit statistics. The hierarchical ordering showed that coordination ability was the most difficult, followed by stability and relating. Response category functioning worked as intended for 19 out of 23 items. There were few difficult items, which decreased targeting. Reliability measures were good. BAS MQ discriminated between the autism and the reference groups, with the autism group exhibiting poorer movement quality, reflecting clinical observations and previous research. Conclusions: BAS MQ was found to have acceptable measurement properties, though suffering from problems with targeting item difficulty to person ability for persons on the autism spectrum. The BAS MQ may, along with experienced movement quality, contribute to clinically relevant information of persons on the autism spectrum, although we encourage refinements and further analyses to improve its measurement properties. 

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  • Yasin, Affan
    et al.
    Northwestern Polytechnical University, China.
    Fatima, Rubia
    Emerson University, Pakistan.
    JiangBin, Zheng
    Northwestern Polytechnical University, China.
    Afzal, Wasif
    Mälardalen University, Sweden.
    Raza, Shahid
    RISE Research Institutes of Sweden, Digital Systems, Data Science. Mälardalen University, Sweden.
    Can serious gaming tactics bolster spear-phishing and phishing resilience?: Securing the human hacking in Information Security2024In: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 170, article id 107426Article in journal (Refereed)
    Abstract [en]

    Context: In the digital age, there is a notable increase in fraudulent activities perpetrated by social engineers who exploit individuals’ limited knowledge of digital devices. These actors strategically manipulate human psychology, targeting IT devices to gain unauthorized access to sensitive data. Objectives: Our study is centered around two distinct objectives to be accomplished through the utilization of a serious game: (i) The primary objective entails delivering training and educational content to participants with a focus on phishing attacks; (ii) The secondary objective aims to heighten participants’ awareness regarding the perils associated with divulging excessive information online. Methodology: To address these objectives, we have employed the following techniques and methods: (i) A comprehensive literature review was conducted to establish foundational knowledge in areas such as social engineering, game design, learning principles, human interaction, and game-based learning; (ii) We meticulously aligned the game design with the philosophical concept of social engineering attacks; (iii) We devised and crafted an advanced hybrid version of the game, incorporating the use of QR codes to generate game card data; (iv) We conducted an empirical evaluation encompassing surveys, observations, discussions, and URL assessments to assess the effectiveness of the proposed hybrid game version. Results: Quantitative data and qualitative observations suggest the “PhishDefend Quest” game successfully improved players’ comprehension of phishing threats and how to detect them through an interactive learning experience. The results highlight the potential of serious games to educate people about social engineering risks. Conclusion: Through the evaluation, we can readily arrive at the following conclusions: (i) Game-based learning proves to be a viable approach for educating participants about phishing awareness and the associated risks tied to the unnecessary disclosure of sensitive information online; (ii) Furthermore, game-based learning serves as an effective means of disseminating awareness among participants and players concerning prevalent phishing attacks. © 2024 The Authors

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  • Ollas, Patrik
    Chalmers University of Technology, Sweden.
    Buildings' Transition to Active Nodes: Assessing the Viability of DC Distribution, PV and Battery Storage2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Historically, buildings have been passive nodes in the electric grid system with one-way power flows. However, with the recent market development of solar photovoltaic (PV) and stationary behind-the-meter battery storage systems, buildings are now transitioning to active nodes, offering bi-directional power flows. Various system topologies and modelling aspects are of interest for these active nodes and their viability. This thesis compares internal building direct current (DC) distribution with the conventional alternating current (AC) distribution for single-family and office buildings. For both building types, the geographical location is altered to examine the effect of PV and load correlation on the DC performance. The energy loss over a year and the loss distribution across various components are examined for three DC topologies, including one with constant power electronic converter (PEC) efficiencies, to quantify the loss discrepancy to experimentally derived PEC efficiency characteristics. Using constant efficiencies for a single-family building underestimates the annual losses by 34% (63 kWh/a). With load-dependant PEC efficiencies and without battery storage, DC operation shows no performance enhancements compared to AC. Depending on the studied case, DC operation results in loss savings, −16.3 to −43.6% with PV and battery.

    Two methods are proposed to reduce the grid-tied converter (GC) losses from partial load operation. One method—a modular GC design consisting of a smaller and a larger GC—is modelled for two cases: a single-family building and an office building, and presents an optimal GC size configuration of 15/85%. The loss savings relative to AC operations for a 15/85% configuration are 26% for the single-family building and 15–40% for the office. The savings depend on the office’s location and system design (PV and battery sizing). For the offices, the effect on DC loss savings is examined via a parametric sweep by varying PV and battery sizes, with resulting savings up to 40% (−12.8 MWh/a) compared to AC operation. The results highlight the effect of GC sizing on the DC performance, the effect of battery storage, and how the PV and load correlation affects the DC performance.

    Furthermore, a battery model is derived from experimental measurements of the cell’s current—resistance and open-circuit voltage (OCV)—state-of-charge (SOC) dependencies. The battery model is verified against the measured voltage with good compliance (RMSE<7 mV). Three representations—including the round trip efficiency approximation—are compared for annual battery system losses. The results indicate that the cell’s losses—making up 22–45% of losses for the examined case—and that the internal resistance’s current dependency is essential for an accurate representation. The loss discrepancy for the round trip approximation varies between −5% to 29%, relative to the experimentally derived representation, depending on the modelled battery size.

    The role of PV and battery storage for an airport micro grid is examined in a forward-looking case with electric aviation (EA) and electric vehicles (EVs). Seven scenarios are studied, including four with battery storage and different operation algorithms. One of the algorithms is a novel operation combining self-consumption (SC) and peak power shaving. Compared to the current situation, the techno-economic evaluation shows a significant increase in energy (89.4%) and power (+1 MW) demands from EA and EV. For the nominal battery price and peak power tariff (Ct), the novel operation shows the shortest Payback Period (PBP) of 4.8 years for the battery scenarios. With varying battery prices and peak power tariffs, the sensitivity analysis shows that Ct can significantly affect the PBP.

    Lastly, the effect of PV module operating temperature on performance is empirically evaluated and quantified for seven arrays from annual operation. For the Building–Applied PV (BAPV) c-Si modules, the elevated operating temperature adds 1% to the total losses and 2% for the c-Si Building–Integrated PV (BIPV). Examining the results of SC and self-sufficiency (SS) verifies the correlation between SC and power rating and introduces the correlation between SS and annual yield, considering the effect of system design, level of roof integration and PV cell type. For this case study, comparing two systems with and without battery storage shows the weekly variation in SS and SC and highlights the drawback of single-objective dispatch.

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  • Pizzul, Leticia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food. RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    del Pilar Castillo, Maria
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Ascue, Johnny
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Nilsson, Eskil
    Biofilter för behandling av bekämpningsmedelsrester2021Report (Other academic)
    Abstract [en]

    Use of biofilter for the treatment of pesticide contaminated water Despite many measures to reduce the risk of pesticides spreading to sensitive environments, their residues are still often found in surface and groundwater. Point sources are a significant cause of such contamination, mainly associated with localized situations, e.g., filling of the tank and washing of the sprayer. According to Sweden's official statistics, 54% of farmers choose some form of concrete surface connected to a collecting tank as a safe pesticide handling place. The collected liquid is later spread on biologically active soil, such as fallow or on stump. However, farmers’ experience indicates that there can be large amounts of water to handle annually, and chemical residues in the spread liquid can have a negative effect on crops. There is a need to improve the existing and future pesticide handling sites to manage large volumes of water safely, easily, and economically. An appropriate and simple solution is the use of a biofilter to treat the collected liquid. The biofilter has been developed based on the Swedish biobed and is used in several countries. It consists of several 1 m3 – plastic containers filled with biomix, and the different units are stacked in a vertical pile and connected with plastic valves and pipes. Contaminated water is collected and circulated through the biofilter and pesticide residues are retained in the biomix where they are degraded by microbial activity. The aim of the project was to adapt the use of the biofilter to Swedish conditions and gain knowledge about how it should be operated. Since water dynamics are an important factor in the biofilter function, the specific goals of the project were to study the effect of the inflow rate on water balance, microbial activity, and pesticide retention in a typical Swedish biomix. For the project a pilot biofilter was built at RISE workshop in Uppsala. A list of the materials needed, the approximate cost of building a biofilter and a preliminary instruction manual for the construction were produced within the frame of the project. The cost of building a 3-unit biofilter was estimated to be approx. 15,000 Swedish crowns. The study was divided into two trials under controlled conditions. First, the effect of inflows on water content and microbial activity in the biomix was investigated. A constant flow rate of 25 L/d was tested in one of the units and an increasing flow of 7, 22 and 40 L/d in another unit. The results showed that the outflow increased with flow rate and was between 50 and 96% of the inflow. Water content in the biomix was lower and fluctuated more on the surface compared to the bottom of the biomix and water retention capacity decreased over time. A tendency to reduced carbon content and microbial activity (measured as respiration rate) over time was observed with the flows > 20 L/d. The levels of glyphosate and diflufenican in the effluent were very low, 0,1 % of the levels in incoming water, regardless the flow. The higher flow reduced the retention capacity of bentazone, i.e., a higher inflow led to higher levels of bentazone in the effluent. According to our results, a typical Swedish biomix, under the conditions tested in this study, can treat a flow lower than 20 L/d without having a major impact on microbial activity and on the pesticide retention capacity. Assuming that the biofilter can be used for 210 days/year (not in winter), approximately 4000 L can be treated in one year with a flow of 20 L/d. Biofilters are a good option for farms with indoor or outdoor pesticide handling areas under roof. For farms with an outdoor concrete area without a roof, where precipitation also ends up in the collection tank, the volumes to treat become too high for a biofilter.

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  • Shetty, N.
    et al.
    Chalmers University of Technology, Sweden.
    Chianese, F.
    Chalmers University of Technology, Sweden.
    He, Hans
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology. Chalmers University of Technology, Sweden.
    Huhtasaari, J.
    Ghasemi, S.
    Universitat Politècnica de Catalunya, Spain.
    Moth-Poulsen, K.
    Universitat Politècnica de Catalunya, Spain; Catalan Institution for Research & Advanced Studies, Sweden; Institute of Materials Science of Barcelona, Spain; Chalmers University of Technology, Sweden.
    Kubatkin, S.
    Chalmers University of Technology, Sweden.
    Bauch, T.
    Chalmers University of Technology, Sweden.
    Lara-Avila, S.
    Chalmers University of Technology, Sweden; NPL, UK.
    Ultralow 1/f noise in epigraphene devices2024In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 124, no 9, article id 093503Article in journal (Refereed)
    Abstract [en]

    We report the lowest recorded levels of 1/ f noise for graphene-based devices, at the level of S V / V 2 = S I / I 2 = 4.4 × 10 − 16 (1/Hz), measured at f = 10 Hz ( S V / V 2 = S I / I 2 < 10 − 16 1/Hz for f > 100 Hz) in large-area epitaxial graphene on silicon carbide (epigraphene) Hall sensors. This performance is made possible through the combination of high material quality, low contact resistance achieved by edge contact fabrication process, homogeneous doping, and stable passivation of the graphene layer. Our study explores the nature of 1/ f noise as a function of carrier density and device geometry and includes data from Hall sensors with device area range spanning over six orders of magnitude, with characteristic device length ranging from L = 1 μm to 1 mm. In optimized graphene Hall sensors, we demonstrate arrays to be a viable route to improve further the magnetic field detection: a simple parallel connection of two devices displays record-high magnetic field sensitivity at room temperature, with minimum detectable magnetic field levels down to B min = 9.5 nT/√Hz. The remarkable low levels of 1/ f noise observed in epigraphene devices hold immense capacity for the design and fabrication of scalable epigraphene-based sensors with exceptional performance. © 2024 Author(s).

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  • Li, Ying Zhen
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Arvidson, Magnus
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Försth, Michael
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety. Luleå University of Technology, Sweden.
    Performance of various water-based fire suppression systems in tunnels with longitudinal ventilation2024In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 146, article id 104141Article in journal (Refereed)
    Abstract [en]

    Low pressure, medium pressure and high pressure water-based fire suppression systems were tested in a medium scale tunnel (scale 1:3). The primary objective was to investigate which of these systems are most effective in the suppression or control of different types of tunnel fires. The default low, medium and high pressure systems refer to full scale water flow rates of 10 mm/min, 6.8 mm/min and 3.7 mm/min, respectively. Some other water densities were also tested to investigate the effects, as well as different ventilation velocities and activation criteria. Several series of fire tests were conducted for different fire scenarios. The fire scenarios considered included idle wood pallet fires, loosely packed wood crib fires, loosely packed wood and plastic crib fires, and pool fires, with or without a top cover on the fuel load. Comparisons of the three default systems based on the three parameters: heat release rate, energy released and possibility of fire spread, show that the performance of the default low pressure system is usually the most effective based on the parameters studied. The default high pressure system usually yields results less effective in comparison to the default low pressure system. The performance of the default medium pressure system usually lies in between them. The high pressure system behaves very differently in comparison to the others, in terms of tunnel ventilation velocity, water density, operating pressure, and the presence of the top cover. © 2024 The Authors

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  • Wärnheim, Alexander
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion. KTH Royal Institute of Technology, Sweden.
    Kotov, Nikolay
    KTH Royal Institute of Technology, Sweden.
    Dobryden, Illia
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. KTH Royal Institute of Technology, Sweden.
    Telaretti Leggieri, Rosella
    KTH Royal Institute of Technology, Sweden.
    Edvinsson, Camilla
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Heydari, Golrokh
    SSAB, Sweden.
    Sundell, Per-Erik
    SSAB, Sweden.
    Deltin, Tomas
    Nordic United Coatings, Sweden.
    Johnson, C. Magnus
    KTH Royal Institute of Technology, Sweden.
    Persson, Dan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Claesson, Per M.
    KTH Royal Institute of Technology, Sweden.
    Nanomechanical and nano-FTIR analysis of polyester coil coatings before and after artificial weathering experiments2024In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 190, article id 108355Article in journal (Refereed)
    Abstract [en]

    Local heterogeneities can have significant effects on the performance of anti-corrosion coatings. Even small features can act as initiation points for damage and result in corrosion of the substrate material. Analysis methods with high spatial resolution and the ability to collect information relevant to crosslinking and degradation behavior of these coatings are therefore highly relevant. In this work, we demonstrate the utility of nanomechanical AFM measurements and nano-FTIR in investigating the nanoscale mechanical and chemical properties of two polyester coil coating clearcoats before and after weathering. On the nanoscale, weathering led to a stiffer and less deformable coating with less variation in the nanomechanical properties. Chemical degradation was quantified using changes in band ratios in the IR-spectra. Macro and nano-scale measurements showed similar trends with the latter measurements showing larger heterogeneity. Our results demonstrate the usefulness of the described analysis techniques and will pave the way for future studies of local properties in other coating systems and formulations. © 2024 The Authors

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  • Sidstedt, Maja
    et al.
    National Forensic Centre, Sweden.
    Gynnå, Arvid H.
    National Forensic Centre, Sweden.
    Kiesler, Kevin M.
    NIST, USA.
    Jansson, Linda
    National Forensic Centre, Sweden; Lund University, Sweden.
    Steffen, Carolyn R.
    NIST, USA.
    Håkansson, Joakim
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology. University of Gothenburg, Sweden.
    Johansson, Gustav
    SIMSEN Diagnostics, Sweden.
    Österlund, Tobias
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Bogestål, Yalda
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Tillmar, Andreas
    National Board of Forensic Medicine, Sweden.
    Rådström, Peter
    Lund University, Sweden.
    Ståhlberg, Anders
    University of Gothenburg, Sweden;Sahlgrenska University Hospital, Sweden.
    Vallone, Peter M.
    NIST, USA.
    Hedman, Johannes
    National Forensic Centre, Sweden; Lund University, Sweden.
    Ultrasensitive sequencing of STR markers utilizing unique molecular identifiers and the SiMSen-Seq method2024In: Forensic Science International: Genetics, ISSN 1872-4973, E-ISSN 1878-0326, Vol. 71, article id 103047Article in journal (Refereed)
    Abstract [en]

    Massively parallel sequencing (MPS) is increasingly applied in forensic short tandem repeat (STR) analysis. The presence of stutter artefacts and other PCR or sequencing errors in the MPS-STR data partly limits the detection of low DNA amounts, e.g., in complex mixtures. Unique molecular identifiers (UMIs) have been applied in several scientific fields to reduce noise in sequencing. UMIs consist of a stretch of random nucleotides, a unique barcode for each starting DNA molecule, that is incorporated in the DNA template using either ligation or PCR. The barcode is used to generate consensus reads, thus removing errors. The SiMSen-Seq (Simple, multiplexed, PCR-based barcoding of DNA for sensitive mutation detection using sequencing) method relies on PCR-based introduction of UMIs and includes a sophisticated hairpin design to reduce unspecific primer binding as well as PCR protocol adjustments to further optimize the reaction. In this study, SiMSen-Seq is applied to develop a proof-of-concept seven STR multiplex for MPS library preparation and an associated bioinformatics pipeline. Additionally, machine learning (ML) models were evaluated to further improve UMI allele calling. Overall, the seven STR multiplex resulted in complete detection and concordant alleles for 47 single-source samples at 1 ng input DNA as well as for low-template samples at 62.5 pg input DNA. For twelve challenging mixtures with minor contributions of 10 pg to 150 pg and ratios of 1–15% relative to the major donor, 99.2% of the expected alleles were detected by applying the UMIs in combination with an ML filter. The main impact of UMIs was a substantially lowered number of artefacts as well as reduced stutter ratios, which were generally below 5% of the parental allele. In conclusion, UMI-based STR sequencing opens new means for improved analysis of challenging crime scene samples including complex mixtures. © 2024 The Authors

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  • Kvarnlöf, Linda
    et al.
    Mid Sweden University, Sweden.
    Eriksson, Kerstin
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Filling the void: Rural disaster volunteerism during the Swedish wildfires of 20182024In: International Journal of Disaster Risk Reduction, E-ISSN 2212-4209, Vol. 105, article id 104393Article in journal (Refereed)
    Abstract [en]

    In the summer of 2018, both fire and rescue services and volunteers fought against the extensive wildfires that spread over the northern parts of Sweden. The challenges were many and one of the most obvious was the lack of resources provided by the state, both material and human. This lack of official resources, together with the long distances that characterize the rural northern parts of Sweden, have been highlighted in subsequent evaluations as one of the main reasons for the widely spread fires. The lack of official resources in itself can be understood as a consequence of several years of dismantling and centralization of the Swedish fire and rescue service. However, the responses from the local community were enormous. Local volunteers, spontaneous as well as organized, assisted in firefighting; in providing food and services; in offering shelter for evacuated, and many other things. In disaster research, volunteer activities have often been described as something that “fills the void” when official resources are scarce. This seems to be particularly true in rural contexts. This paper applies a critical perspective on rural disaster volunteerism by framing it as an expression of rural vulnerability and peripheralization: as something that is performed as a compensatory act in rural communities affected by social dismantling. In other words, both place and politics are central in understanding rural voluntary activity. Inspired by the theoretical concept geographies of voluntarism, this paper argues that people make sense of volunteer initiatives in relation to both the place where these activities take place and in relation to the power relations associated with this place. Therefore, the purpose of this paper is to explore how rural disaster volunteerism intersects with structural conditions of rurality. © 2024 The Authors

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  • Haukø, Anne-Marit
    et al.
    Garberg Olsø, Brynhild
    Mysen, Mads
    Ingebrigtsen, Sturla
    Samuelsen, Per Henning
    Byenstuen, Tommy
    Dovran, Freddy
    Øyen Knutsen, Peer
    Haug, Hugo
    Kausland, Åge
    Tvilde, Tor
    Fjærestad, Janne Siren
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Meraner, Christoph
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Prosjektnotat : Kontrollplan – Ventilasjonsanleggets funksjon under brann2024Report (Other academic)
    Abstract [no]

    Dette notatet er en delleveranse i arbeidspakke WP3 i prosjektet BRAVENT – Effektiv ventilasjon av røyk fra små branner. Notatet med tilhørende vedlegg Kontrollplan gir en beskrivelse av hvordan periodisk kontroll og daglig/ukentlig internkontroll av ventilasjonsanleggets funksjon under brann i skolebygg kan utføres. Kontrollplanen kan også være nyttig for bruk i andre offentlige formålsbygg.

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  • Haukø, Anne-Marit
    et al.
    Garberg Olsø, Brynhild
    Mysen, Mads
    Ingebrigtsen, Sturla
    Samuelsen, Per Henning
    Byenstuen, Tommy
    Dovran, Freddy
    Øyen Knutsen, Peer
    Kværner Hestetun, Johanne
    Haug, Hugo
    Kausland, Åge
    Tvilde, Tor
    Fjærestad, Janne Siren
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Meraner, Christoph
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    BRAVENT – Veileder for brannteknisk prosjektering av ventilasjonsanlegg i skolebygg2024Report (Other academic)
    Abstract [no]

    Dette dokumentet er en veileder. Veilederen skal benyttes av rådgivende ingeniører i brannteknisk prosjektering av ventilasjonsanlegg i skolebygg. Det fokuseres på rømningssikkerhet og skadebegrensning ved små branner i en tidlig fase av brannforløpet. Veilederen beskriver forutsetninger for bruk, krav og preaksepterte ytelser i VTEK, samt ulike typer ventilasjonsanlegg med tilhørende komponenter. Dokumentet illustrerer typiske prinsippløsninger for ulike ventilasjonsstrategier i bygg, samt forskningsresultater fra brannforsøk og undersøkelser i tidligere faser av BRAVENT-prosjektet. Veilederen tar for seg nybygg, eksisterende bygg og verneverdige bygg hvor grensesnittet mellom rådgivende ingeniør brann (RIBr), ventilasjon (RIV), elektro (RIE) og automasjon (RIAut) defineres. En sjekkliste oppsummerer viktige punkter å hensynta ved prosjektering av ventilasjonsanlegg. Rutiner for drift og vedlikehold beskrives til slutt.

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  • Meraner, Christoph
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Fjærestad, Janne Siren
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    BRAVENT – Storskala branntester (del 2): Effekten av ventilasjonsstrategi på røykspredning og trykkontroll i en mock-up skolebygning2024Report (Other academic)
    Abstract [en]

    BRAVENT – Large-scale fire tests (part 2): The effect of the ventilation strategy on smoke dispersion and pressure control in a mock-up school building In the overall BRAVENT project, the goal is to generate answers and documentation on current issues related to ventilation and fire by examining these with experimental fire tests. The present study aimed to evaluate how different failure mechanisms identified in sub-report 1, "Fire performance for non-fire rated ventilation components" [5], affect the pressure conditions and possible smoke spread in the building. In order to investigate the ventilation system's ability to control pressure balance and smoke spread in the event of a fire, 14 large-scale fire tests with different fuel types were carried out. The tests were conducted in a test building with several rooms representing a classroom, an office and a corridor. The fire tests were designed to investigate relevant fire scenarios for school buildings, but the findings from the tests may also be relevant for other purpose-built buildings. The building was equipped with a full-fledged damper-optimized ventilation system which was sized to serve a total of 450 m2 and thus provide a realistic basis for the fire tests. In sub-report 1, a number of component failures were uncovered when the system was exposed to hot smoke. The failure mechanisms led to the system losing its status and control over the dampers, thus also losing the overview of which air volumes passed through the dampers. The failure of the dampers then led to an imbalance in the ventilation system, also in rooms other than the fire room. In the extreme, this can lead to challenges in connection with escape by making it difficult or impossible to open doors. Smoke spread via the supply air ducts can occur due to smoke backflow if the pressure in the fire compartment exceeds the pressure in the supply air duct. In the experiments, the ventilation system increased to the maximum design airflow rate (Vmax) upon fire detection, and no smoke spread due to backflow of fire smoke in the supply air ducts was observed. It was not tested whether a backflow of smoke could have also been prevented at lower airflow rates than Vmax. Whether the ventilation system maintains sufficiently high pressure in the supply air duct to prevent backflow depends on, among other things, the capacity of the supply air fans, the density of the fire compartment and how quickly the fire develops. The smoke from the fire caused the filter in the unit to gradually clog. In three tests, the filter was clogged so much that the air handling unit could not extract enough air, which created an imbalance in the ventilation system. The new BRAVENT tests show that the size of the fire in relation to the air handling unit's capacity plays an important role in how long the exhaust airflow can be maintained. An air handling unit serving several small fire cells with limited available fuel will be able to maintain the required exhaust air volume longer than an aggregate serving a few large fire cells as the ratio between smoke volume and total air volume changes. Other factors that affect how long the unit can compensate for filter clogging are: • whether the air handling unit is designed for 100% or less simultaneity, i.e. the proportion of rooms that can have the maximum amount of airflow at the same time, • the condition of the filter at the start of the fire, completely new filters were used in each of the fire tests, • whether the ventilation system operates with Vmax or less airflow when a fire alarm is triggered. No smoke spread between the rooms via the exhaust duct was observed. However, since the exhaust airflow rate in one of the tests was significantly reduced to around 50% of the maximum design airflow rate, it is concluded that gradual clogging of the exhaust filter will increase the risk of smoke spreading via the exhaust duct. Clogging of the filters can be avoided by establishing a bypass. Nevertheless, it must then still be documented that all other functions of the ventilation system are safeguarded in the event of a fire. The tests carried out showed that the failure mechanism of some components (measurement errors in dampers, short circuits and clogging of the exhaust filters) can lead to the whole system no longer being able to maintain its function.

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  • Fjærestad, Janne Siren
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Yang, Aileen
    SINTEF, Norway.
    Dovran, Freddie
    Oslobygg KF, Norway.
    Olsen, Jørn
    GK Norge, Norway.
    Meraner, Christoph
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    BRAVENT – Storskala branntester (del 1): Brannytelse for ikke-brannklassifiserte ventilasjonskomponenter2024Report (Other academic)
    Abstract [en]

    BRAVENT – Large-scale fire tests (part 1): Fire performance for non-fire rated ventilation components In the overall BRAVENT project, the goal is to generate answers and documentation on current issues related to ventilation and fire by examining these with experimental fire tests. The present study aimed to evaluate the fire performance of key non-fire-rated components, mainly DCV dampers and exhaust filters, in a comfort ventilation system by testing the hypothesis that the ventilation components will not be damaged by fire within 30 or 60 minutes. To test the hypothesis, a total of 14 large-scale fire tests with different fuels were carried out. The tests were carried out in a test building with several rooms that are representative of classrooms, offices, and corridors. The fire tests were designed to investigate relevant fire scenarios for school buildings, but the findings from the tests can also be used for other purpose-built buildings. The building was equipped with a full-fledged damper-optimized ventilation system, sized to serve a total of 450 m2 and thus provide a realistic basis for the fire tests. Currently, there is no documentation on how non-fire-rated dampers are affected by high temperatures that occur during a fire. The temperature specifications given for non-fire rated DCV dampers are intended for normal operation. Two different types of DCV dampers were tested. In one type, the airflow was measured with a measuring cross, and for the other, the airflow was measured with sensors integrated into the damper blade itself. In several of the conducted tests the non-fire-rated dampers were not able to sustain their function for the required duration of 30 minutes or longer, and failed completely when the temperature inside or outside the dampers reached about 200 ºC. Misreporting of some temperature measurements in the building management system already occurred at lower temperatures, around 120˚C, without significantly affecting the delivered air flow rate. For the damper type with a measuring cross, the plastic hoses connecting the measuring cross and the measuring transducer for the damper melted when hot smoke was transported through the damper. This failure resulted in the DCV damper measuring too low or no airflow. In several tests, this measurement error meant that the DCV damper opened fully, trying to achieve a large enough airflow. In one of the tests where the supply air damper was placed inside the fire room, such a fault on the supply air damper caused it to close completely. In addition to the damage to the dampers, the power supply to the damper was destroyed, and a fuse for the power supply in the control cabinet was short-circuited. This resulted in the building management system losing contact with all the dampers. This shows that a local error can cause the entire system to fail. For the other damper type, where the sensors were located in the damper blade, the high temperatures caused the entire damper blade to melt. It was not observed that soot in the fire smoke led to problems with the dampers' measuring sensors for any of the damper types examined. This indicates that for the performed test series, high temperature and not soot was the greatest challenge for the dampers in the event of a fire. In addition to examining how dampers are affected by fire, there was also an investigation into how the filter performs during a fire. It was found that the filter could largely capture the soot particles in the smoke. This means that equipment located downstream of the filter is relatively well protected against soot, and the possibility of soot contamination to the supply air side via a rotating heat recovery unit can, therefore, be considered minimal as long as the filter is not damaged. However, when the filter collects so much soot, it shows that the potential for the filter to clog. How quickly this happens depends, among other things, on the materials that burn and the size of the fire in relation to the air handling unit's capacity. This also aligns with results from an earlier BRAVENT project [1]. The air temperature in the unit was in all tests carried out below 60˚C and thus lower than the filters' maximum operating temperature of 70˚C. The conclusion from the tests is that the extraction principle with non-fire-rated components cannot be considered a safe strategy for 30 or 60 minutes.

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  • Gålfalk, Magnus
    et al.
    Linköping University, Sweden.
    Nilsson Påledal, Sören
    Tekniska Verken AB, Sweden.
    Yngvesson, Johan
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    Bastviken, David
    Linköping University, Sweden.
    Measurements of Methane Emissions from a Biofertilizer Storage Tank Using Ground-Based Hyperspectral Imaging and Flux Chambers2024In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 58, no 8, p. 3766-3775Article in journal (Refereed)
    Abstract [en]

    Open storages of organic material represent potentially large sources of the greenhouse gas methane (CH4), an emissions source that will likely become more common as a part of societal efforts toward sustainability. Hence, monitoring and minimizing CH4 emissions from such facilities are key, but effective assessment of emissions without disturbing the flux is challenging. We demonstrate the capacity of using a novel high-resolution hyperspectral camera to perform sensitive CH4 flux assessments at such facilities, using as a test case a biofertilizer storage tank for residual material from a biogas plant. The camera and simultaneous conventional flux chamber measurements showed emissions of 6.0 ± 1.3 and 13 ± 5.7 kg of CH4 h-1, respectively. The camera measurements covered the whole tank surface of 1104 m2, and the chamber results were extrapolated from measurements over 5 m2. This corresponds to 0.7-1.4% of the total CH4 production at the biogas plant (1330 N m3 h-1 corresponding to 950 kg h-1). The camera could assess the entire tank emission in minutes without disturbing normal operations at the plant and revealed additional unknown emissions from the inlet to the tank (17 g of CH4 h-1) and during the loading of the biofertilizer into trucks (3.1 kg of CH4 h-1 during loading events). This study illustrates the importance of adequate measurement capacity to map methane fluxes and to verify that methane emission mitigation efforts are effective. Given the high methane emissions observed, it is important to reduce methane emissions from open storage of organic material, for example by improved digestion in the biogas reactor, precooling of sludge before storage, or building gastight storage tanks with sealed covers. We conclude that hyperspectral, ground-based remote sensing is a promising approach for greenhouse gas monitoring and mitigation. © 2024 The Authors. 

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  • Arrhenius, Karine
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Applied Mechanics.
    Morris, Abigail
    NPL, UK.
    Hookham, Mathew
    NPL, UK.
    Moore, Niamh
    NPL, UK.
    Modugno, Pierpaolo
    NPL, UK.
    Bacquart, Thomas
    NPL, UK.
    An inter-laboratory comparison between 13 international laboratories for eight components relevant for hydrogen fuel quality assessment2024In: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 230, article id 114553Article in journal (Refereed)
    Abstract [en]

    The quality of the hydrogen delivered by refuelling stations is critical for end-users and society. The purity of the hydrogen dispensed at hydrogen refuelling points should comply with the technical specifications included in the ISO 14687:2019 and EN 17124:2022 standards. Once laboratories have set up methods, they need to verify their performances, for example through participation in interlaboratory comparisons. Due to the challenge associated with the production of stable reference materials and transport of these which are produced in hydrogen at high pressure (>10 bar), interlaboratory comparisons have been organized in different steps, with increasing extent. This study describes an inter-laboratory comparison exercise for hydrogen fuel involving a large number of participants (13 laboratories), completed in less than a year and included eight key contaminants of hydrogen fuel at level close to the ISO14687 threshold. These compounds were selected based on their high probability of occurrence or because they have been found in hydrogen fuel samples. For the results of the intercomparison, it appeared that fully complying with ISO 21087:2019 is still challenging for many participants and highlighted the importance of organising these types of exercises. Many laboratories performed corrective actions based on their results, which in turn significantly improved their performances. © 2024 The Author(s)

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  • Bergentall, Martina
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Niimi, Jun
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Persson, Ingela
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Calmet, Emeline
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    As, Dorine
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Plovie, Alexander
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Malafronte, Loredana
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Melin, Petter
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Malolactic fermentation in lingonberry juice and its use as a preservative2024In: Food microbiology (Print), ISSN 0740-0020, E-ISSN 1095-9998, Vol. 121, article id 104500Article in journal (Refereed)
    Abstract [en]

    Lingonberry is a common wild berry that is often sold as jams and beverages. It naturally contains high amounts of the weak acid preservative benzoic acid making it an interesting ingredient for shelf-life extension. Despite this, their use as a raw ingredient is limited by the inherently intense sour taste. This study aimed to improve the taste of lingonberry juice by subjecting it to malolactic fermentation in order to reduce the sourness, and to investigate the benzoic acid in lingonberries as a natural preservative in juice blends by determining the microbial stability. After initial screening of lactic acid bacteria, a Lactiplantibacillus plantarum strain was used as the starter for subsequent investigations. Upon raising the pH, all malic acid was completely converted to lactic acid after seven days. The fermented juice was mixed with blackcurrant juice in different proportions. Challenge tests of the blends showed Listeria monocytogenes could not grow in any juice samples, while Candida albicans only grew in the pure blackcurrant juice. Aspergillus brasiliensis growth was delayed in all samples containing benzoic acid in a concentration-dependent manner. The sourness and astringency were substantially reduced in the juice with added L. plantarum compared to the unfermented juice. © 2024 The Authors

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  • Irannezhad, Mohsen
    et al.
    Chalmers University of Technology, Sweden.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard E.
    Chalmers University of Technology, Sweden.
    Eslamdoost, Arash
    Chalmers University of Technology, Sweden.
    Experimental and numerical investigations of propeller open water characteristics in calm water and regular head waves2024In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 302, article id 117703Article in journal (Refereed)
    Abstract [en]

    Propeller Open Water (POW) performance of a non-ventilating and fully-submerged propeller in model-scale is investigated in calm water and regular head waves using experimental tests (EFD) and Computational Fluid Dynamics (CFD). Laminar flow dominance is observed in calm water, particularly at higher advance ratios. Nevertheless, the findings in waves suggest increased turbulence, stemming from both the wave orbital velocities and the presumably increased turbulence level produced by the wave maker in the towing tank. Analysis of the CFD results obtained from the incident flow field and single-blade force and moment leads to the speculation that the observed discrepancies are associated with the inevitable asymmetric conditions and mechanical interference in the experiments which were absent in CFD. These can potentially alter the flow over the blades resulting in a different flow transition, separation, and coherent turbulent structure formation and hence forces and moments. The altered propeller performance in waves in comparison to calm water underlines the significance of waves on the propulsive factors and propeller design. © 2024 The Authors

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  • Amorebieta, Josu
    et al.
    University of the Basque Country, Spain.
    Pereira, Joao
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Franciscangelis, Carolina
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Durana, Gaizka
    University of the Basque Country, Spain.
    Zubia, Joseba
    University of the Basque Country, Spain.
    Villatoro, Joel
    University of the Basque Country, Spain.
    Margulis, Walter
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Carbon-coated fiber for optoelectronic strain and vibration sensing2024In: Optical fiber technology (Print), ISSN 1068-5200, E-ISSN 1095-9912, Vol. 85, article id 103794Article in journal (Refereed)
    Abstract [en]

    In this article, we report on a carbon-coated optical fiber that is suitable to be used simultaneously as a transmission medium and as a sensor. It consists of a standard single mode fiber (SMF) sleeved in two layers of coating, which provide protection and isolation from external elements. The inner layer is made of carbon, whereas the outer is made of polymer. When the fiber is subjected to mechanical stress, the electrical resistance of the carbon layer changes accordingly. The voltage variations caused by the former can be measured with high accuracy and without interfering with the light propagating through the SMF. In this work, the feasibility of this operating principle is demonstrated in a low coherence Michelson interferometer in which electrical and optical signals were measured simultaneously and compared to each other. Results indicate that electrical measurements are as precise as the optical ones and with linear behavior, reaching a sensitivity of 1.582 mV/με and able to detect vibrations down to 100 mHz. © 2024 The Authors

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  • Böckler, H B
    et al.
    PTB, Germany.
    de Huu, M.
    METAS, Switzerland.
    Maury, R.
    CECAME, France.
    Schmelter, S.
    PTB, Germany.
    Schakel, M. D.
    VSL, Netherlands.
    Büker, Oliver
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Kutin, J.
    University of Ljubljana, Slovenia.
    Bobovnik, G.
    University of Ljubljana, Slovenia.
    Wedler, C.
    Imperial College London, UK.
    Trusler, J. P. M.
    Imperial College London, UK.
    Thol, M.
    Ruhr-University Bochum, Germany.
    Weiss, S.
    PTB, Germany.
    Günz, C.
    PTB, Germany.
    Schumann, D.
    PTB, Germany.
    Gugole, F.
    VSL, Netherlands.
    Metrology infrastructure for high-pressure gas and liquified hydrogen flows. A brief outline of the MetHyInfra project, measurement challenges, and first results2024In: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 232, article id 114675Article in journal (Refereed)
    Abstract [en]

    This paper gives an overview of the ongoing Joint Research Project (JRP) 20IND11 “Metrology infrastructure for high pressure gas and liquefied hydrogen flows” (MetHyInfra), which will ensure traceability in the hydrogen distribution chain. For this purpose, very precise nozzles with well-defined geometries have been produced. In this project, Critical Flow Venturi Nozzles (CFVNs) will be traceably calibrated for the first time with hydrogen and pressures up to 100 MPa using a Coriolis Flow Meter (CFM) as a secondary standard. A CFM has been successfully calibrated with hydrogen against a gravimetric primary standard. Equations of State (EoS) are important for the high-pressure calibration of the nozzles, but also for Computational Fluid Dynamics (CFD) simulations. With regard to CFD, a numerical model has been developed to simulate high pressure hydrogen flow in the CFVN. In a parameter study, non-ideal nozzle shapes are investigated using a shape variation parameter. New Speed of Sound (SoS) measurements were conducted at temperatures from 273 to 323 K and pressures from 1 to 100 MPa. These new data were then used to develop a new EoS for normal hydrogen, optimized for gas phase calculations. In addition to gaseous hydrogen, the project has a strong focus on liquefied hydrogen. Here a three-pronged approach allows traceable measurements. Each of the approaches presented is based on a unique flow calibration principle and relies on independent traceability schemes. The results of the project will ensure traceable measurements and thus a higher level of confidence among end users. © 2024 The Authors

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  • Rolseth, Anton
    et al.
    Jönköping University, Sweden.
    Carlsson, Marco
    MIT Massachusetts Institute of Technology, USA; Polestar Performance AB, Sweden.
    Ghassemali, Ehsan
    Jönköping University, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Jarfors, Anders E.W.
    Jönköping University, Sweden.
    Impact of functional integration and electrification on aluminium scrap in the automotive sector: A review2024In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 205, article id 107532Article in journal (Refereed)
    Abstract [en]

    The shift towards vehicle electrification must progress while simultaneously addressing sustainability challenges related to lightweighting, which is the intensifying need for high-quality primary aluminium, which demand cannot be met with recycled material with traditional compositional limits. To understand and predict the characteristics of future scrap mixtures, it is crucial to comprehend the evolving composition of new components and associated trends. This insight helps alloy design that accommodates higher impurities and, thus, a more thoughtful strategy for materials process development research. This review delves into the impact of electric motors, batteries, and functional integration. Notably, the analysis herein indicates a rise in magnesium (Mg) and a decrease in copper (Cu) and silicon (Si) contents in the future scrap mixtures due to more Al–Mg alloys such as those found in the 5xxx (Al–Mg) and 6xxx (Al–Mg–Si) series and an outflux of high Al–Si–Cu engine alloys. Gigacastings might counteract this trend based on their Si content and adoption and promote circularity principles by reducing alloy varieties. Reduced Si content in future scrap mixtures is also expected to boost sustainability since significant CO2 emissions from recycled alloys come from melting, controlled by the latent heat of fusion of the scrap mix. © 2024 The Authors

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  • Rad, Mehran
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food. Lund University, Sweden.
    Abtahi, Azra
    Lund University, Sweden.
    Berndtsson, Ronny
    Lund University, Sweden.
    McKnight, Ursula S.
    SMHI, Sweden.
    Aminifar, Amir
    Lund University, Sweden.
    Interpretable machine learning for predicting the fate and transport of pentachlorophenol in groundwater2024In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 345, article id 123449Article in journal (Refereed)
    Abstract [en]

    Pentachlorophenol (PCP) is a commonly found recalcitrant and toxic groundwater contaminant that resists degradation, bioaccumulates, and has a potential for long-range environmental transport. Taking proper actions to deal with the pollutant accounting for the life cycle consequences requires a better understanding of its behavior in the subsurface. We recognize the huge potential for enhancing decision-making at contaminated groundwater sites with the arrival of machine learning (ML) techniques in environmental applications. We used ML to enhance the understanding of the dynamics of PCP transport properties in the subsurface, and to determine key hydrochemical and hydrogeological drivers affecting its transport and fate. We demonstrate how this complementary knowledge, provided by data-driven methods, may enable a more targeted planning of monitoring and remediation at two highly contaminated Swedish groundwater sites, where the method was validated. We evaluated 6 interpretable ML methods, 3 linear regressors and 3 non-linear (i.e., tree-based) regressors, to predict PCP concentration in the groundwater. The modeling results indicate that simple linear ML models were found to be useful in the prediction of observations for datasets without any missing values, while tree-based regressors were more suitable for datasets containing missing values. Considering that missing values are common in datasets collected during contaminated site investigations, this could be of significant importance for contaminated site planners and managers, ultimately reducing site investigation and monitoring costs. Furthermore, we interpreted the proposed models using the SHAP (SHapley Additive exPlanations) approach to decipher the importance of different drivers in the prediction and simulation of critical hydrogeochemical variables. Among these, sum of chlorophenols is of highest significance in the analyses. Setting that aside from the model, tetra chlorophenols, dissolved organic carbon, and conductivity found to be of highest importance. Accordingly, ML methods could potentially be used to improve the understanding of groundwater contamination transport dynamics, filling gaps in knowledge that remain when using more sophisticated deterministic modeling approaches. © 2024 The Authors

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  • Melkamu Daniel, Aemiro
    et al.
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Hunka, Agnieszka D.
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Vanacore, Emanuela
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Habibi, Shiva
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Medin, Ingrid
    Swedish Food Agency, Sweden.
    Kautto, Arja H.
    Swedish Food Agency, Sweden; SLU Swedish University of Agricultural Sciences, Sweden.
    Expert elicitation of remote meat inspection prerequisites in Sweden using best-worst scaling (case 1)2024In: Food Control, ISSN 0956-7135, E-ISSN 1873-7129, Vol. 162, article id 110460Article in journal (Refereed)
    Abstract [en]

    Remote work technologies offer unprecedented flexibility to modernise official meat inspection (MI). Remote meat inspections, alongside on-site controls have a potential to make MI more sustainable when it comes to working conditions, logistic control hurdles and travel-related emissions. Nevertheless, preferences of meat control staff for features and technological set up of remote MI remain unknown. The paper investigates preferences of official Swedish MI staff for different features of remote MI. The study utilises a quantitative method, namely best-worst scaling to compare the relative importance of six aspects of remote inspections: camera location and settings, connectivity, availability of personnel at abattoirs, communication and language, security and fraud prevention, and ability to relay olfaction and haptics. The survey, administered in September–October 2023 was answered by 54.7% of the Swedish meat control staff employed by the Swedish Food Agency. The results show that respondents rate security and fraud prevention (Security) as the most important aspect for remote MI followed by connectivity and camera placement (Camera). Communication and language (Communication) and ability to relay olfaction and haptics (Senses) are considered the least important aspects. The latter findings can be explained by the fact that Official Veterinarians, which represent the majority of respondents (49%), do not routinely communicate directly with slaughter personnel who are often seasonal workers coming from outside Sweden. Moreover, olfaction and haptics could be considered naturally impractical with remote technologies. The study also finds that respondents from different administrative units and job titles have different preferences for the features of remote MI. Respondents from the headquarter generally have higher preferences for connectivity than respondents from other units. Additionally, respondents with more hands-on experience in MI, such as Official Veterinarians, tend to rate security issues higher than respondents with leading or support roles. Overall, it seems possible to meet the control staff expectations and preferences regarding the prerequisites of remote MI by legal and technical adaptations needed for this type of control flexibility. © 2024 The Authors

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  • Janhäll, Sara
    et al.
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Strandberg, Bo
    Lund University, Sweden; Region Skåne, Sweden.
    Wallqvist, Viveca
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Rissler, Jenny
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. Lund University, Sweden.
    A new method and first results for comparing emissions of fumes during construction of asphalt surfaces2024In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 422, article id 135736Article in journal (Refereed)
    Abstract [en]

    A novel laboratory methodology for analysing hot asphalt fumes from various paving materials is presented and evaluated. This method facilitates comparative assessments, aiming to enhance occupational safety for asphalt workers and ensure safe implementation of new paving materials. Comparative analyses of emissions to air were conducted on standard asphalt and rubber-modified asphalt at different temperatures. The temperature significantly influences PAH emissions. Rubber-modified asphalt demonstrated higher PAH emissions at equivalent temperatures compared to standard asphalt, predominantly naphthalene. Even heavier PAHs as benzo(a)pyrene were occasionally high. Notably, at recommended working temperatures the standard asphalt resulted in higher emissions, comprising heavier PAHs compared to rubber asphalt. © 2024 The Authors

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  • Petsagkourakis, Ioannis
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Beni, Valerio
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Strandberg, Jan
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Nilsson, Marie
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Leandri, Valentina
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical Process and Pharmaceutical Development.
    Lassen, Bo
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical Process and Pharmaceutical Development.
    Sandberg, Mats
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Polymerization of benzoxazine impregnated in porous carbons. A scalable and low-cost route to smart copper-ion absorbents with saturation indicator function2024In: Process Safety and Environmental Protection, ISSN 0957-5820, E-ISSN 1744-3598, Vol. 184, p. 782-789Article in journal (Refereed)
    Abstract [en]

    Porous carbon materials are common materials used for sensor and absorbent applications. A novel approach for functionalizing porous carbons through the impregnation of porous carbon black with benzoxazine monomers, followed by thermal polymerization is introduced herein. The method not only establishes a new avenue for the functionalization of porous carbons but also endows the resulting material with both copper ion-binding and sensing properties. We showcase the versatility of the technique by illustrating that the polymerization of phenols with benzoxazine monomers serves as an extra tool to customize absorption- and sensing properties. Experimental validation involved testing the method on carbon black as a porous substrate, which was impregnated with both bisphenol-a benzoxazine and a combination of bisphenol-a benzoxazine and alizarin. The resulting materials were assessed for their dual functionality as both an absorbent and a sensor for copper ions by varied copper ion concentrations and exposure times. The dye absorption test demonstrated a notable capacity to accumulate copper ions from dilute solutions. Electrochemical characterization further confirmed the effectiveness of the modified carbons, as electrodes produced from inks were successful in detecting copper ions accumulated from 50 μM Cu2+ solutions. With this work, we aspire to set the steppingstone towards a facile functionalization of porous carbon materials towards water purification applications. © 2024 The Authors

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  • Rabel, Kerstin
    et al.
    University of Freiburg, Germany.
    Blankenburg, Andrea
    University of Freiburg, Germany.
    Steinberg, Thorsten
    University of Freiburg, Germany.
    Kohal, Ralf J.
    University of Freiburg, Germany.
    Spies, Benedikt C.
    University of Freiburg, Germany.
    Adolfsson, Erik
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Witkowski, Siegbert
    University of Freiburg, Germany.
    Altmann, Brigitte
    University of Freiburg, Germany.
    Gingival fibroblast response to (hybrid) ceramic implant reconstruction surfaces is modulated by biomaterial type and surface treatment2024In: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 40, no 4, p. 689-699Article in journal (Refereed)
    Abstract [en]

    Objectives: Surface characteristics of implant reconstructions determine the gingival fibroblast (GF) response and thus soft tissue integration (STI). However, for monolithic implant reconstructions it is unknown whether the (hybrid) ceramic biomaterial type and its surface treatment affect GF response. Therefore, this investigation examined the influence of the implant reconstruction biomaterials hybrid ceramic (HC), lithium disilicate ceramic (LS), 4 and 5 mol% yttria partially stabilized zirconiumdioxide ceramics (4/5Y-PSZ) and their surface treatment - machining, polishing or glazing - on surface characteristics and GF response. Methods: After characterization of surface topography and wettability by scanning electron microscopy, interferometry and contact angle measurement, the adhesion, morphology, metabolic activity and proliferation of GFs from six donors was investigated by fluorescent staining and a resazurin-based assay at days 1, 3 and 7. Titanium (Ti) served as control. Results: Biomaterial type and surface treatment affected the GF response in a topography-dependent manner. Smooth polished and glazed surfaces demonstrated enhanced GF adhesion and earlier proliferation onset compared to rough machined surfaces. Due to minor differences in surface topography of polished and glazed surfaces, however, the GF response was similar for polished and glazed HC, LS, 4- and 5Y-PSZ as well as Ti. Significance: Within the limits of the present investigation, polishing and glazing of machined HC, LS and 4/5Y-PSZ can be recommended to support STI-relevant cell functions in GF. Since the GF response on polished and glazed HC, LS, 4- and 5Y-PSZ surfaces and the Ti control was comparable, this investigation proofed equal cytocompatibility of these surfaces in vitro. © 2024 The Authors

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  • Krentz, Konrad-Felix
    et al.
    Uppsala University, Sweden.
    Voigt, Thiemo
    RISE Research Institutes of Sweden, Digital Systems, Data Science. Uppsala University, Sweden.
    Secure opportunistic routing in 2-hop IEEE 802.15.4 networks with SMOR2024In: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 217, p. 57-69Article in journal (Refereed)
    Abstract [en]

    The IEEE 802.15.4 radio standard features the possibility for IEEE 802.15.4 nodes to run on batteries for several years. This is made possible by duty-cycling medium access control (MAC) protocols, which allow IEEE 802.15.4 nodes to leave their radios in energy-saving sleep modes most of the time. Yet, duty-cycling MAC protocols usually incur long routing delays since it may take a while until a particular forwarder becomes available for forwarding a packet. Opportunistic routing alleviates this problem by opportunistically using a currently available forwarder, rather than waiting for a particular forwarder. Among all opportunistic routing schemes, so-called dynamic switch-based forwarding (DSF) schemes are most promising from a security and practical perspective, but some security and reliability issues with them persist. In this paper, we propose secure multipath opportunistic routing (SMOR), a DSF scheme that improves on current DSF schemes in three regards. First, SMOR builds on a denial-of-sleep-resilient MAC layer. Current DSF schemes, by comparison, rest on MAC protocols that put the limited energy reserves of battery-powered IEEE 802.15.4 nodes at risk. Second, SMOR operates in a distributed fashion and efficiently supports point-to-point traffic. All current DSF schemes, by contrast, suffer from a single point of failure and focus on convergecast traffic. Third, SMOR duplicates packets on purpose and routes them along disjoint paths. This makes SMOR tolerant of compromises of single IEEE 802.15.4 nodes, whereas current DSF schemes lack intrusion tolerance. We integrated SMOR into the network stack of the Contiki-NG operating system and benchmarked SMOR against the Routing Protocol for Low-Power and Lossy Networks (RPL) with the Cooja network simulator. Indeed, SMOR turns out to improve on RPL’s delays by between 33.51% and 39.84%, depending on the exact configurations and network dynamics. Furthermore, SMOR achieves between 0.16% and 2.03% higher mean packet delivery ratios (PDRs), thereby attaining mean PDRs of 99.999% in all simulated scenarios. Beyond that, SMOR has only a fraction of RPL’s memory requirements. SMOR’s intrusion tolerance, on the other hand, increases the mean energy consumption per IEEE 802.15.4 node by between 1.55% and 2.74% compared to RPL in our simulations. SMOR specifically targets IEEE 802.15.4 networks with a network diameter of 2, such as body area networks. © 2024 The Authors

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  • Kauniste, Maarja
    et al.
    Tallinn University of Technology, Estonia; Arro and Agasild Inseneribüroo OÜ, Estonia.
    Just, Alar
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety. Tallinn University of Technology, Estonia.
    Tuhkanen, Eero
    Tallinn University of Technology, Estonia.
    Kalamees, Targo
    Tallinn University of Technology, Estonia.
    Assessment on Strength and Stiffness Properties of Aged Structural Timber2024In: Journal of Sustainable Architecture and Civil Engineering, ISSN 2029-9990, Vol. 34, no 1, p. 62-74Article in journal (Refereed)
    Abstract [en]

    Despite the growing popularity of wood and wood-based products in the construction industry, there has been insufficient focus on assessing the condition, preservation, and potential reuse of existing timber. While numerous standards evaluate the quality of freshly sawn timber, there is currently no standardized system for assessing the strength properties of aged and reused timber. The lack of these guidelines is also one of the reasons the results obtained in numerous research are often fluctuating, and we cannot draw clear conclusions. The matter is further complicated by the lack of data on old in-situ wood and its exploitation, which would help to evaluate its condition. Consequently, there is a real practical need to assess the condition of old timber to avoid unnecessary demolition and the loss of valuable and structurally sound building material. What sets this study apart from others is that, in addition to destructive testing, the 4-point non-destructive (ND) bending tests were conducted on all four faces of test specimens. This provided an opportunity to assess the wood visually and then find connections to associate external characteristics with real properties. This methodology aimed to determine whether it is feasible to visually assess the most practical way to use wooden elements in construction. If this question arises, which face of the beam would be better suited for the tension side and which for the compression side? The old timber used in testing originated from an old library building located on Vaksali Street, Tartu, Estonia and is estimated to be about 120 years old. This paper investigates and compares the collected data with a Nordic standard for grading fresh-sawn timber and two established Italian standards for visually assessing aged timber. This comparison contributes to developing a standardized framework for future visual assessments. ND and destructive four-point bending tests were performed to validate and find appropriate visual characteristics to determine the strength and stiffness of the timber elements. The primary goals of this study were first to compare the results obtained from existing ND methods with actual results and secondly to provide guidelines for better visual grading of wood in the future, based on Nordic Standard INSTA 142 (2010) and Italian standards UNI 11119 (2004) and UNI 11035 (2010) Contrary to previous research conclusions, the visual assessment results yielded unexpected outcomes. The results show that the grading standards significantly underestimated the real strength of the wood, and even more, none of the visual assessments overestimated the real strength of the specimens. Therefore, based on prior research and the findings derived from this study, there is evident a substantial potential for extensive development and optimization within this field.

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  • Staaf, Henrik
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Matsson, Simon
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Sepheri, Sobhan
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Köhler, Elof
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Daoud, Kaies
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware. Breas AB, Sweden.
    Ahrentorp, Fredrik
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Jonasson, Christian
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Folkow, Peter
    Chalmers University of Technology, Sweden.
    Ryynänen, Leena
    Nokian Tyres Plc, Finland.
    Penttila, Mika
    Nokian Tyres Plc, Finland.
    Rusu, Cristina
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Simulated and measured piezoelectric energy harvesting of dynamic load in tires2024In: Heliyon, E-ISSN 2405-8440, Vol. 10, no 7, article id e29043Article in journal (Refereed)
    Abstract [en]

    From 2007 in US and from 2022 in EU it is mandatory to use TPMS monitoring in new cars. Sensors mounted in tires require a continuous power supply, which currently only is from batteries. Piezoelectric energy harvesting is a promising technology to harvest energy from tire movement and deformation to prolong usage of batteries and even avoid them inside tires. This study presents a simpler method to simultaneous model the tire deformation and piezoelectric harvester performance by using a new simulation approach - dynamic bending zone. For this, angular and initial velocities were used for rolling motion, while angled polarization was introduced in the model for the piezoelectric material to generate correct voltage from tire deformation. We combined this numerical simulation in COMSOL Multiphysics with real-life measurements of electrical output of a piezoelectric energy harvester that was mounted onto a tire. This modelling approach allowed for 10 times decrease in simulation time as well as simpler investigation of systems parameters influencing the output power. By using experimental data, the simulation could be fine-tuned for material properties and for easier extrapolation of tire deformation with output harvested energy from simulations done at low velocity to the high velocity experimental data.

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  • Carreiro, Elisabete P.
    et al.
    University of Évora, Portugal.
    Federsel, Hans-Jürgen
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical Process and Pharmaceutical Development. University of Évora, Portugal; ChiraTecnics, Portugal.
    Hermann, Gesine J.
    University of Évora, Portugal; ChiraTecnics, Portugal.
    Burke, Anthony J.
    University of Évora, Portugal; Universidade de Coimbra, Portugal; .
    Stereoselective Catalytic Synthesis of Bioactive Compounds in Natural Deep Eutectic Solvents (NADESs): A Survey across the Catalytic Spectrum2024In: Catalysts, E-ISSN 2073-4344, Vol. 14, no 3, article id 160Article in journal (Refereed)
    Abstract [en]

    Deep eutectic solvents (DESs) are a mixture of two or more components, and at a particular composition, they become liquids at room temperature. When the compounds that constitute the DESs are primary metabolites namely, amino acids, organic acids, sugars, or choline derivatives, the DESs are called natural deep eutectic solvents (NADESs). NADESs fully represent green chemistry principles. These solvents are highly welcome, as they are obtained from renewable resources, and gratifyingly are biodegradable and biocompatible. They are an alternative to room-temperature ionic liquids (RTILs). From the pharmaceutical industry’s point of view, they are highly desirable, but they unfortunately have been rarely used despite their enormous potential. In this review, we look at their impact on the asymmetric catalytic synthesis of key target molecules via metal-based catalysis, biocatalysis, and organocatalysis. In many cases, the NADESs that have been used are chiral and can even promote enantioselective reactions; this crucial and very exciting aspect is also discussed and analyzed. © 2024 by the authors.

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  • Rabe, Hardis
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology. University of Gothenburg, Sweden.
    Lönnermark, Elisabeth
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Johansson, Ewa
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Gilljam, Marita
    Sahlgrenska University Hospital, Sweden.
    Jönsson, Bodil
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    In vitro stimulation with nontuberculous mycobacteria induced a stronger cytokine response in leukocytes isolated from individuals with latent tuberculosis compared to those isolated from active tuberculosis or cystic fibrosis patients2024In: Tuberculosis, ISSN 1472-9792, E-ISSN 1873-281X, Vol. 147, article id 102504Article in journal (Refereed)
    Abstract [en]

    Mycobacterium tuberculosis and opportunistic environmental non-tuberculous mycobacteria (NTM) can cause severe infection. Why latent tuberculosis infection advances to active disease, and why some individuals with cystic fibrosis (CF) develop pulmonary infections with NTM is still poorly understood. The aim of this study was to investigate the effector function of peripheral blood mononuclear cells (PBMC) from individuals with active or latent tuberculosis, individuals with CF with or without pulmonary NTM-infection and healthy controls, by measuring cytokine response to in vitro stimulation with different species of NTMs. The cytokine concentrations of IL-17A, IL-22, IL-23, IL-10, IL12p70 and IFN-γ were measured in PBMC-culture supernatants after stimulation with NTMs. PBMCs from individuals with latent tuberculosis infection showed strong IL-17A, IL-22, and IFN-γ responses compared to individuals with active tuberculosis or CF. IL-10 production was low in both tuberculosis groups compared to the CF groups and controls. This study suggests that IL-17A and IL-22 might be important to keep tuberculosis in a latent phase and that individuals with CF with an ongoing NTM infection seem to have a low cytokine response. © 2024 The Authors

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  • Yücel, Yasemin Duygu
    et al.
    KTH Royal Institute of Technology, Sweden.
    Adolfsson, Erik
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Dykhoff, Henrik
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Pettersson, Jocke
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Trey, Stacy
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Wysocki, Maciej
    Widenkvist Zetterström, Erika
    Graphmatech AB, Sweden.
    Zenkert, Dan
    KTH Royal Institute of Technology, Sweden.
    Wreland Lindström, Rakel
    KTH Royal Institute of Technology, Sweden.
    Lindbergh, Goran
    KTH Royal Institute of Technology, Sweden.
    Enhancing structural battery performance: Investigating the role of conductive carbon additives in LiFePO4-Impregnated carbon fiber electrodes2024In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 251, article id 110571Article in journal (Refereed)
    Abstract [en]

    This study centers on investigating the influence of conductive additives, carbon black (Super P) and graphene, within the context of LiFePO4 (LFP)-impregnated carbon fibers (CFs) produced using the powder impregnation method. The performance of these additives was subject to an electrochemical evaluation. The findings reveal that there are no substantial disparities between the two additives at lower cycling rates, highlighting their adaptability in conventional energy storage scenarios. However, as cycling rates increase, graphene emerges as the better performer. At a rate of 1.5C in a half-cell versus lithium, electrodes containing graphene exhibited a discharge capacity of 83 mAhgLFP−1; those with Super P and without any additional conductive additive showed a capacity of 65 mAhgLFP−1 and 48 mAhgLFP−1, respectively. This distinction is attributed to the structural and conductivity advantages inherent to graphene, showing its potential to enhance the electrochemical performance of structural batteries. Furthermore, LFP-impregnated CFs were evaluated in full cells versus pristine CFs, yielding relatively similar results, though with a slightly improved outcome observed with the graphene additive. These results provide valuable insights into the role of conductive additives in structural batteries and their responsiveness to varying operational conditions, underlining the potential for versatile energy storage solutions. © 2024 The Authors

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  • Wang, Zhendong
    et al.
    Stockholm University, Sweden.
    Samsten, Isak
    Stockholm University, Sweden.
    Miliou, Ioanna
    Stockholm University, Sweden.
    Mochaourab, Rami
    RISE Research Institutes of Sweden, Digital Systems, Industrial Systems.
    Papapetrou, Panagiotis
    Stockholm University, Sweden.
    Glacier: guided locally constrained counterfactual explanations for time series classification2024In: Machine Learning, ISSN 0885-6125, E-ISSN 1573-0565Article in journal (Refereed)
    Abstract [en]

    In machine learning applications, there is a need to obtain predictive models of high performance and, most importantly, to allow end-users and practitioners to understand and act on their predictions. One way to obtain such understanding is via counterfactuals, that provide sample-based explanations in the form of recommendations on which features need to be modified from a test example so that the classification outcome of a given classifier changes from an undesired outcome to a desired one. This paper focuses on the domain of time series classification, more specifically, on defining counterfactual explanations for univariate time series. We propose Glacier, a model-agnostic method for generating locally-constrained counterfactual explanations for time series classification using gradient search either on the original space or on a latent space that is learned through an auto-encoder. An additional flexibility of our method is the inclusion of constraints on the counterfactual generation process that favour applying changes to particular time series points or segments while discouraging changing others. The main purpose of these constraints is to ensure more reliable counterfactuals, while increasing the efficiency of the counterfactual generation process. Two particular types of constraints are considered, i.e., example-specific constraints and global constraints. We conduct extensive experiments on 40 datasets from the UCR archive, comparing different instantiations of Glacier against three competitors. Our findings suggest that Glacier outperforms the three competitors in terms of two common metrics for counterfactuals, i.e., proximity and compactness. Moreover, Glacier obtains comparable counterfactual validity compared to the best of the three competitors. Finally, when comparing the unconstrained variant of Glacier to the constraint-based variants, we conclude that the inclusion of example-specific and global constraints yields a good performance while demonstrating the trade-off between the different metrics. © The Author(s) 2024.

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  • Sehic, Edina
    et al.
    University of Gothenburg, Sweden.
    de Miguel Gómez, Lucía
    University of Gothenburg, Sweden.
    Rabe, Hardis
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology. University of Gothenburg, Sweden.
    Thorén, Emy
    University of Gothenburg, Sweden.
    Gudmundsdottir, Ingigerdur
    University of Gothenburg, Sweden.
    Oltean, Mihai
    University of Gothenburg, Sweden.
    Akouri, Randa
    University of Gothenburg, Sweden.
    Brännström, Mats
    University of Gothenburg, Sweden.
    Hellström, Mats
    University of Gothenburg, Sweden; Stockholm IVF-EUGIN, Sweden.
    Transplantation of a bioengineered tissue patch promotes uterine repair in the sheep2024In: Biomaterials Science, ISSN 2047-4830, E-ISSN 2047-4849, Vol. 12, no 8, p. 2136-2148Article in journal (Refereed)
    Abstract [en]

    Innovative bioengineering strategies utilizing extracellular matrix (ECM) based scaffolds derived from decellularized tissue offer new prospects for restoring damaged uterine tissue. Despite successful fertility restoration in small animal models, the translation to larger and more clinically relevant models have not yet been assessed. Thus, our study investigated the feasibility to use a 6 cm2 graft constructed from decellularized sheep uterine tissue, mimicking a future application to repair a uterine defect in women. Some grafts were also recellularized with fetal sheep bone marrow-derived mesenchymal stem cells (SF-MSCs). The animals were followed for six weeks post-surgery during which blood samples were collected to assess the systemic immune cell activation by fluorescence-activated cell sorting (FACS) analysis. Tissue regeneration was assessed by histology, immunohistochemistry, and gene expression analyses. There was a large intra-group variance which prompted us to implement a novel scoring system to comprehensively evaluate the regenerative outcomes. Based on the regenerative score each graft received, we focused our analysis to map potential differences that may have played a role in the success or failure of tissue repair following the transplantation therapy. Notably, three out of 15 grafts exhibited major regeneration that resembled native uterine tissue, and an additional three grafts showed substantial regenerative outcomes. For the better regenerated grafts, it was observed that the systemic T-cell subgroups were significantly different compared with the failing grafts. Hence, our data suggest that the T-cell response play an important role for determining the uterus tissue regeneration outcomes. The remarkable regeneration seen in the best-performing grafts after just six weeks following transplantation provides compelling evidence that decellularized tissue for uterine bioengineering holds great promise for clinically relevant applications. © 2024 The Royal Society of Chemistry

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  • Caselli, Lucrezia
    et al.
    University of Copenhagen, Denmark; Lund University, Sweden.
    Parra-Ortiz, Elisa
    University of Copenhagen, Denmark; Novonesis, Denmark.
    Micciulla, Samantha
    Institut Laue-Langevin, France; Laboratoire Interdisciplinaire de Physique, France; CNRS, France.
    Skoda, Maximilian W. A.
    Rutherford Appleton Laboratory, UK.
    Malekkhaiat Häffner, Sara
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical Process and Pharmaceutical Development. University of Copenhagen, Denmark.
    Nielsen, Emilie Marie
    University of Copenhagen, Denmark.
    van der Plas, Mariena J.A.
    University of Copenhagen, Denmark.
    Malmsten, Martin
    University of Copenhagen, Denmark; Lund University, Sweden.
    Boosting Membrane Interactions and Antimicrobial Effects of Photocatalytic Titanium Dioxide Nanoparticles by Peptide Coating2024In: Small, ISSN 1613-6810, E-ISSN 1613-6829Article in journal (Refereed)
    Abstract [en]

    Photocatalytic nanoparticles offer antimicrobial effects under illumination due to the formation of reactive oxygen species (ROS), capable of degrading bacterial membranes. ROS may, however, also degrade human cell membranes and trigger toxicity. Since antimicrobial peptides (AMPs) may display excellent selectivity between human cells and bacteria, these may offer opportunities to effectively “target” nanoparticles to bacterial membranes for increased selectivity. Investigating this, photocatalytic TiO2 nanoparticles (NPs) are coated with the AMP LL-37, and ROS generation is found by C11-BODIPY to be essentially unaffected after AMP coating. Furthermore, peptide-coated TiO2 NPs retain their positive ζ-potential also after 1–2 h of UV illumination, showing peptide degradation to be sufficiently limited to allow peptide-mediated targeting. In line with this, quartz crystal microbalance measurements show peptide coating to promote membrane binding of TiO2 NPs, particularly so for bacteria-like anionic and cholesterol-void membranes. As a result, membrane degradation during illumination is strongly promoted for such membranes, but not so for mammalian-like membranes. The mechanisms of these effects are elucidated by neutron reflectometry. Analogously, LL-37 coating promoted membrane rupture by TiO2 NPs for Gram-negative and Gram-positive bacteria, but not for human monocytes. These findings demonstrate that AMP coating may selectively boost the antimicrobial effects of photocatalytic NPs. © 2024 The Authors. 

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  • Gustafsson, Emil
    et al.
    Uppsala University, Sweden.
    Hellsing, Maja
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical Process and Pharmaceutical Development.
    Rennie, Adrian R.
    Uppsala University, Sweden.
    Welbourn, Rebecca J. L.
    Rutherford Appleton Laboratory, UK.
    Campana, Mario
    Rutherford Appleton Laboratory, UK.
    Hughes, Arwel
    Rutherford Appleton Laboratory, UK.
    Li, Peixun
    Rutherford Appleton Laboratory, UK.
    Melander Bowden, Tim
    Uppsala University, Sweden.
    Understanding interactions of plasticisers with a phospholipid monolayer2024In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 20, no 13, p. 2892-2899Article in journal (Refereed)
    Abstract [en]

    The use of DEHP (diethylhexyl phthalate) is now banned for most applications in Europe; the exception is for blood bags, where its toxicity is overshadowed by its ability to extend the storage life of red blood cells. Another plasticiser, BTHC (butanoyl trihexyl citrate), is used in paediatric blood bags but does not stabilise blood cells as effectively. Interactions between plasticisers and lipids are investigated with a phospholipid, DMPC, to understand the increased stability of blood cells in the presence of DEHP as well as bioaccumulation and identify differences with BTHC. Mixed monolayers of DMPC and DEHP or BTHC were studied on Langmuir troughs where surface pressure/area isotherms can be measured. Neutron reflection measurements were made to determine the composition and structure of these mixed layers. A large amount of plasticiser can be incorporated into a DMPC monolayer but once an upper limit is reached, plasticiser is selectively removed from the interface at high surface pressures. The upper limit is found to occur between 40-60 mol% for DEHP and 20-40 mol% for BTHC. The areas per molecule are also different with DEHP being in the range of 50-100 Å2 and BTHC being 65-120 Å2. Results indicate that BTHC does not fit as well as DEHP in DMPC monolayers which could help explain the differences observed with regards to the stability of blood cells.

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  • Zackrisson, Mats
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Livscykelanalys av rostskydd - broar2018Report (Other academic)
    Abstract [sv]

    Denna rapport innehåller en livscykelanalys av rostskyddsmålning av broar. Analysen har gjorts inom ramen för ett uppdrag utfört åt Swerea KIMAB och Trafikverket av Mats Zackrisson vid Swerea IVF, i projektet Funktionsbaserad kravställning för rostskyddsmålning inom infrastruktur. Såväl Trafikverket, färgtillverkare, målningsentreprenörer, målningskontrollanter och forskare vid Swerea KIMAB har bidragit med data och kunskaper till studien. Så låg miljöpåverkan som möjligt under livscykeln är ett rimligt funktionskrav att ställa vid upphandling av rostskyddsmålning. Denna rapport visar på några vägar att minimera klimatpåverkan och bildandet av marknära ozon: • Minskad förbrukning av blästermedel vid reparationsmålning • Stationsmålning med kolsnål elmix • VOC-destruktion vid nymålning • Reparationsmålning i station om möjligt • Så få reparationsmålningar i fält som möjligt Man kan dock inte utesluta att resultaten i denna rapport kan inspirera till ytterligare sätt att minimera miljöpåverkan.

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  • Tidbeck, Björn
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Funktionsbaserad kravställning för rostskyddsmålning inom infrastrukturen: Del 1-Förstudie2016Report (Other academic)
    Abstract [sv]

    Trafikverket har som mål att öka andelen totalentreprenad som kontraktsform till 50 % av all verksamhet fram till år 2018. Totalentreprenad är en övergripande strategisk satsning som syftar till att öka produktiviteten, främja innovationer och minska miljöpåverkan i anläggningsbranschen. Den är också ett steg i riktningen mot Trafikverkets nya roll som en renodlad beställarorganisation, mot ökad samverkan mellan beställare och entreprenörer och i förlängningen mot utvecklade innovationssystem och renodlad funktionsupphandling. Totalentreprenad är endast en kontraktsform och den egentliga drivkraften som ska införliva många av de tänkta fördelarna med totalentreprenad är funktionsbaserad upphandling. Genom att upphandla en funktion istället för en produkt ges entreprenörer och leverantörer friheter att tillämpa och utveckla mer effektiva produktionsmetoder och produkter. Trafikverkets nuvarande kravställning inom rostskyddsmålning innehåller utförandekrav som minimerar entreprenörens möjligheter till egna initiativ. Den nuvarande kravställningen riskerar därmed att försvåra utvecklingen av Trafikverkets övergripande strategier och begränsa potentialen hos totalentreprenad. En förändring av kravställningen är därför nödvändig för att totalentreprenader ska kunna ge de fördelar som man förväntar sig. Denna rapport är första delen av en utredning som syftar till att formulera en alternativ funktionsbaserad kravställning som harmoniserar bättre med totalentreprenad som kontraktsform. Rapportens syfte är att belysa konsekvenser, fördelar och nackdelar med funktionskrav inom området rostskydd. Rapporten utgör en förstudie som ska ligga till grund för ett konkret förslag till en funktionsbaserad kravställning vid upphandling av rostskydd. Rapporten belyser relevanta aspekter i gällande standarder, Trafikverkets nuvarande kravställning, alternativa produkter på marknaden idag samt en begränsad omvärdsanalys av trender i branschen och kravställning hos andra beställarorganisationer. Förstudien är i grunden en litteraturstudie men innefattar även intervjuer med specialister i branschen, både inom rostskyddsmålning och alternativa upphandlingsformer. Representanter från beställare, produktleverantörer och entreprenörer finns också med bland intervjuobjekten. Rostskyddsmålning är en känslig process som är beroende av ett antal kritiska moment under förbehandling och applicering. Ett lyckat resultat ger ett korrosionsskydd med lång livslängd, ca 25år. Vidare är det mycket svårt att bestämma korrosionsskyddets förväntade livslängd genom att enbart utföra kontroll av den färdiga produkten. Dessa förutsättningar innebär att rostskyddsmålning inte är ett område som är idealiskt lämpat för funktionsupphandling. Funktionskrav är förenat med ekonomiska risker och utförandekrav riskerar att ge en för långsam produkttillämpning av nya alternativa produkter och metoder. En strategi för att utnyttja fördelarna med båda dessa kravtyper är att utföra funktionsbaserad upphandling för en delmängd av den offentliga upphandlingen. Den lärdom och de erfarenheter som uppkommer i samband med funktionsupphandling kan sedan överföras till utförandekrav för huvuddelen av den offentliga upphandlingen. På detta sätt kan ekonomiska risker minimeras och nya produkter kan provas och utvärderas på verkliga objekt inom ramen för offentlig upphandling.

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  • Tidbeck, Björn
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Stenbeck, Torbjörn
    Mapit, Sweden.
    Zackrisson, Mats
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Funktionsbaserad kravställning för rostskyddsmålning inom infrastrukturen: Del 2-upphandlingsstrategier och tekniska krav2019Report (Other academic)
    Abstract [sv]

    Med funktionsbaserad kravställning avses i detta arbete en blandning av funktionskrav och utförandekrav. Målet med en funktionsbaserad kravställning är att hitta ett optimum mellan funktionskrav och utförandekrav, så att introduktion av nya förbättrade produkter och produktionsmetoder underlättas utan att risken för misslyckanden blir alltför stora. De funktionskrav som beskrivs i denna rapport förväntas lämpa sig bäst för projekt där anbud på rostskyddet kan utvärderas separat. Sådana projekt kan vara nymålning eller komplett ommålning i projekt där målningsentreprenaden upphandlas separat. Att använda funktionskrav i nybyggnadsprojekt där målningen endast utgör en liten del av det totala projektet, riskerar att resultera i att rostskyddet får underordnad betydelse i anbudsutvärderingen. I detta arbete har vi definierat nio generella funktionsmål, vilka betraktas som oreglerade krav som definierar ett idealiskt rostskydd. Om beställaren för varje objekt inventerar behoven i entreprenaden och beslutar om en prioriteringsordning av funktionsmålen, kan rangordningen användas för att ta fram objektspecifika funktionskrav. För att stimulera till nytänkande och användning av alternativa produkter och processlösningar skulle det vara fördelaktigt att tillåta sidoanbud i upphandlingar med funktionskrav. Entreprenörerna skulle till exempel kunna lämna ett huvudanbud som ska följa den generella kravställningen med utförandekrav enligt SIS-TS 44, och ett kompletterande sidoanbud som adresserar de objektspecifika funktionskraven och funktionsmålen. Sidoanbuden kan utvärderas med livscykelanalyser, typprovning och inspektion av referensobjekt. Inom projektet har arbetsgruppen tagit fram en LCA-analys och en LCC analys för dagens målningsprogram så som det beskrivs i SIS-TS 44. Inom projektet har den gällande kravställningen i SIS-TS 44 granskats med utgångspunkt att revidera de krav som kan komma att stå i vägen för tillämpningen av nya alternativa produkter och metoder med förbättrade egenskaper. Avsnitt 9 i rapporten innehåller en sammanfattad handlingsplan för hur en funktionsbaserad kravställning skulle kunna användas för att introducera nya produkter och metoder i Trafikverkets krav för rostskyddsmålning.

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  • Pålsson, Namurata
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Tidbeck, Björn
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Stam, Björn
    ST Control, Sweden.
    Refurbishment of hot dip galvanized products – environmental impacts in a life cycle perspective2022Report (Other academic)
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  • Pålsson, Namurata
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Tidbeck, Björn
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Emission of microplastics from maritime paints2022Report (Other academic)
    Abstract [en]

    Research on microplastic pollution is currently a well-established field and has gone beyond the focus of academia to the general public. It was speculated in 2019 that the amount of microplastics in certain oceanic compartments would double by 2030. On the global point of view, key sources of primary microplastics released into the ocean, are (1) plastic pellets, (2) synthetic textiles, (3) tyres, (4) road markings, (5) marine paints, (6) personal care products and (7) city dust. Paints used for marine application can be damaged or degraded due to several factors, e.g. solar radiation, high salinity, temperature fluctuation, wet-dry cycles, mechanical friction, macro and micro living species. Such processes alter both physical and chemical properties of the paints and most often lead to generation of secondary microplastics. In 2017 marine paints were reported to contributed to 3.7% of global releases of microplastics to the world oceans. The most recent published technical report in 2022 indicated contribution of marine paints as high as 7%. Human exposure to microplastics may occur via ingestion, inhalation and dermal contact due to the presence of microplastics in products, food and air. Annual microplastics consumption, focusing on the American diet, ranges from 39 000 to 52 000 particles depending on age and sex. When inhalation is taken into account, these estimates increase to 74 000 and 121 000. The accumulation of microplastic particles in humans may lead to health risks, e.g. cytotoxicity, hypersensitivity, unwanted immune response, and acute response like hemolysis. As exemplified above, hazards of microplastic pollution needs a call for attention to reduce the plastic debris in marine environment. This report aims to investigate the current literature on the topic of microplastics, with special attention to microplastics from marine coatings in marine eco systems. The conclusion from this study is that research to find alternative coating systems for marine applications and for material in contact with drinking water and food is needed. The authors suggestions are that such research should focus on: • Efforts to produce paint that can be bio-degraded once it become microplastic litter • Efforts to produce plastic free paints with adequate anticorrosion/ antifouling properties. • Efforts to replace toxic, bio-accumulable materials/ ingredients from marine paint formulations

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  • Tidbeck, Björn
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Makdesy, Alexi
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Round Robin trial of accelerated corrosion testing and comparison with field exposureat a C5 marine test site2023Report (Other academic)
    Abstract [en]

    This study is part of a Round robin trial conducted by the International Standardisation Organisation (ISO). The study was intended to form a technical background to the revision of the accelerated corrosion testing included in the ISO 12944- series. More specifically, the Round robin trial aimed to investigate the repeatability of accelerated corrosion testing performed at different testing facilities by different testing bodies. The field exposure covered in this report was carried out as an add-on project. The add-on project was initiated to be able to compare the accelerated corrosion testing performed in the Round robin trial with coating degradation in a “real” environment. The field exposure was carried out during four years on the Swedish west coast at RISE testing facility Kvarnvik väst on Bohus-Malmön.

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  • Antonsson, Ulf
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    Delreparation av tätskiktssystem – del 2 - Fältundersökning2022Report (Other academic)
    Abstract [en]

    Partial repair of waterproofing systems – Part 2 - Field survey

    This research project has been terminated prematurely at the request of the funder. The decision to terminate was made as the project has not received suitable objects to the extent required for the project to be carried out as it was planned and promised in the application. It has been unexpectedly difficult to get suitable objects for the project. The idea was that the insurance companies represented in the project team would provide the project with suitable objects. Only four objects have been received for the project. In these objects, humidity sensors have been deployed and measurements have begun. With the Invisense system, only starting measurements to be used as a reference to the next measurement have been carried out. This means that there are no trends to ana-lyse. For the other measurement systems (iioote and Talkpool), the measurements have been ongoing for about six and nine months respectively. In some of the objects, the measurements do not start after installation. It is likely that the sensors do not have contact with the internet via the LoRaWAN technology used. At the objects where measurements start, the moisture level appears to be at a normal level, there does not seem to be any leakage.

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    RISE rapport
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    NCC rapport
  • Räftegård, Oskar
    et al.
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Dahl, Jonas
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Flexibility opportunities in a CHP and district heating system2023Report (Other academic)
    Abstract [en]

    In this report, flexibility is discussed in terms of the ability of a unit or a system of units to change their electricity production or consumption to participate in these ancillary services. In district heating units, the electrical flexibility is strongly correlated with the thermal flexibility which in turn is very site specific. This report makes some proposals on what measures could be carried out to improve flexibility and grade them by implementation difficulty and cost estimates. Most of the measures refer to some upgrades in CHP plants to increase these plants’ flexibility potential towards the ancillary servics. These measures affect not only the electricity output of CHP plants but also the heat output. The report also discusses several means to access heat supply flexibility, to support the CHP plants’ power flexibility. This report also serves as an easy introduction to heat production in district heating systems and, in particular to CHP plants, targeted at experts in other fields to get a basic understanding of some technical aspects and limitations of district heating systems.

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  • Hamon, Camille
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Abdollahi, Elnaz
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Dahl, Jonas
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Räftegård, Oskar
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Sector coupling of district heating with the electricity system: profitability and operations (SeCoHeat)2023Report (Other academic)
    Abstract [en]

    District heating systems can play key roles in the energy transition. The transition to a production mix based on renewable intermittent generation will create a larger need for ancillary services including frequency-regulation services. District heating systems typically participate in the wholesale electricity market (the so-called day-ahead market) today but do not, in general, participate in ancillary service markets. Previous studies have shown that it is technically possible to participate in these markets and that district heating systems have a role to play in these markets in the future. This requires investigating how further integration of district heating systems with the electrical grids and markets will impact operation and planning of these units. In addition, while it may be beneficial on a system level for district heating systems to participate in ancillary service markets, district heating system owners and operators will only do so if there are economic incentives to do so. The SeCoHeat project has therefore explored topics related to the profitability for individual district heating systems to participate in other electricity markets than just the day-ahead market, such as ancillary service markets. Studying sector coupling between the heat and electricity systems requires a thorough understanding of both sectors. This project has contributed to this by bringing together experts from both sides which has led to fruitful knowledge exchanges. Furthermore, some deliverables from the SeCoHeat project have been especially written to provide introduction about the heat sector to experts from the electricity sector, and vice versa. This includes an overview of the electricity markets in which district heating systems can participate, the technical requirements to participate in these markets and explanations about how profitability of participating in these markets can be computed. This also includes explanations about how the flexibility on the heat side can be sourced and provided to the electricity system and what limits this flexibility. Another important contribution of this project is the development of a Python-based open model for scheduling district system units on an hourly basis to minimize heat and electricity production costs while maximising revenues from several electricity markets. This model has been used in this project to evaluate the additional profits of participating in ancillary service markets. The results show that substantial additional profits can be made by doing so, both in historical years and in scenarios for future years. This report is a guide to the separate deliverables produced within this project. It offers an overview of the goals, methods and results from the project. The interested reader is referred to detailed descriptions in the corresponding deliverables. The SeCoHeat project was funded by Göteborg Energi AB:s stiftelse för forskning och utveckling. The work has been performed by RISE with the support of reference group members from Göteborg Energi, Vattenfall, Svenska kraftnät, IVL Svenska Miljöinstitutet, Chalmers and Profu.

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  • Hamon, Camille
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Considering temperatures in operational planning of district heating systems2023Report (Other academic)
    Abstract [en]

    The project SeCoHeat aims at assessing the additional profits that district heating systems can make by participating in new electricity markets, such as ancillary service markets. A model has been developed to schedule district heating units on an hourly basis to minimize heat and electricity production costs while maximizing revenues from electricity markets. This model works with hourly energy flows. In this report, the importance of considering temperature quality in district heating networks when scheduling district heating units is investigated. Temperature quality refers to controlling mass flows and supply temperatures to ensure acceptable confort at the end-consumers. Traditional scheduling models use an energy-only formulation where energy is related to the product of temperaturate and mass flows. They do not consider these two quantities separately and, therefore, are unable to capture temperature quality aspects. On the other hand, these traditional scheduling models are less complex than a full representation of both temperatures and mass flows. Traditional scheduling models based on an energy-only formulation can be expressed as MILP optimization problems, whereas considering both temperatures and mass flows lead to MINLP optimization problems which are must harder to solve. Several simplications and reformulations have been proposed in this report to make the full MINLP problem less complex. These simplifications reduce the number of non-linear equations and, for one of them, even leads to a MILP formulation. In addition, a literature review about exisiting linear reformulations of the full MINLP problem and the importance of considering temperature quality is performed. This report gives a ground to further develop scheduling models that make tradeoffs between model complexity and accurate representation of temperature quality.

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  • Hamon, Camille
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Abdollahi, Elnaz
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Profit estimation for district heating systems when participating in electricity and ancillary service markets2023Report (Other academic)
    Abstract [en]

    Profits generated by district heating systems when participating in ancillary service markets in the electricity sector are studied in this report. An hourly scheduling model is developed to optimally schedule district heating units to meet the heat demand, minimize costs and maximize revenues from electricity markets. The output is used to evaluate the additional profits made by participating in the existing Swedish ancillary markets in addition to the day-ahead electricity market. Case studies are run in two district heating systems, one in Nyköping and one in Gothenburg, for the historical years of 2021 and 2022. Nyköping’s system is also used to evaluate potential profits from ancillary service markets in future scenarios for 2025, 2035 and 2045. Finally, Nyköping’s system is used to evaluate potential additional profits generated by two investments that enhance the flexibility that can be provided to the electricity sector: better CHP ramp rates and larger thermal storage. The analysis of the results shows, for both historical and future years, that participating in ancillary services brings about additional profits. These vary depending on the year, studied district heating system. Profits from electricity markets are shown to increase by up to 40% in Nyköping and 200% in Gothenburg when looking at the historical years. Doubling the CHP ramp rates ability for delivering ancillary services or doubling the size of the heat storage are shown to result in up to another 6% of additional profits. In the future scenarios, profits from electricity markets are shown to increase by up to 94%.

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  • Jansson, Anna
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Almasi, Alexandra
    IVL, Sweden.
    Nellström, Maja
    IVL, Sweden.
    Smarta återvinningsloopar för plastfilm i pallemballage2022Report (Other academic)
    Abstract [en]

    Closed smart loops for stretch films

    In this project, we have investigated the possibilities of sorting packaging, pallet stretch film, stretch hood and shrink hood into cleaner fractions than sorted out today. All these films are used to protect goods that are transported on pallets. The films are mostly sorted together as flexible plastic that is recycled into garbage bags. If the different films can be sorted into different fractions, they can be recycled into a new similar film in a closed loop. The demand for sorted material is great because Trioworld, which is one of the world's largest film manufacturers, aims to use 30% recycled material in all their products. We have investigated the possibilities of sorting different types of plastic film at two different types of businesses, the Västra Götaland Region's Depot in Sisjön, distributing goods to the region's hospitals and health centres. The other business was Inovyn, manufacturing plastic raw material. The collections were sucessful and VGR managed to increase the stretch film content in the flexible plastic stream from 82 to 96 %. Material properties such as strain at break for blown film increased from 535 to 604% in machine direction. Trioworld judged the sorted material to function in a closed material loop for production of new stretch film. The biggest obstacle was the paper labels with the addressee put on the plastic film, impossible to remove easily. When re-melting and compounding the plastic, paper labels burn and clog the melt filter in the equipment. In addition, the mechanical properties deteriorate due to the label contamination. The solution is to use plastic labels or use glue that comes off in hot water and can be washed off. In the VGR sorting the labels were cut off to show the potential for recycling well-sorted pallet stretch film without paper labels. Inovyn had no labels in their sorted films. They separated their flow of flexible film in three fractions, stretch hood, shrink hood and stretch film. A significant improvement was for example observed for the shrink hood where the elongation increased from 326 to 414% on blown film in the machine direction. The material fractions were 100% correctly sorted. On a workshop the project partners discussed challenges and obstacles to make a closed loop work. To make recycling work in practice, the type of labels needs to be changed. Logistics and retrieval of different material fractions separately is needed. The inhouse collection worked, but waste collectors and logistic companies need to be involved in future project to overcome the obstacles.

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  • Berggren, Göran
    et al.
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    Johansson, Marie
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    30 år av träbyggande – nedslag kring förvaltningsaspekter2023Report (Other academic)
    Abstract [en]

    Thirty years of building with wood Sweden has a long tradition of building in wood. Today’s tall wooden buildings, often higher than two stories, are based on completely different technical solutions to the ones used historically. Modern wood construction is rooted in extensive international and national research and development – not on a single national tradition. It began simultaneously across Europe, as the rule change was part of an EU directive. Modern wood construction is also characterized by a high level of industrial prefabrication and short construction times, while modern IT is widely used in the planning and production process. Altogether, these factors entail a very different process from concept to completion, to the one used in the traditional construction industry. A whole host of factors determine the value of a building. It must be fit for purpose, sustainable and attractive. It should be eco-friendly and able to be erected and managed at a reasonable cost. Five different organizations have now been interviewed about their experiences and about the property management. All the interviewees are very positive to build, use and manage wooden buildings. Experience they have gathered by themselves and in cooperation with others give them the confidence to keep building with wood. They can meet every present and predicted demand by customers and governmental rule or regulation. The setbacks are few and easy to solve and interviewees can’t find any reason to not build in wood.

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  • Suchorzewski, Jan
    et al.
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    During, Otto
    Prieto Rábade, Miguel
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    Concrete mix design for tidal turbine foundation2021Report (Other academic)
    Abstract [en]

    The Sabella D10 tidal turbine was immersed in the Fromveur Strait in June 2015 and became the first, and at the time only, grid-connected full scale marine current turbine (MCT) in France. However, the future of MCT industrial projects lies in lowering the levelized cost of electricity (LCOE). Evaluating new possibilities to design a competitive foundation will be a key issue for the future commercial development of SABELLA’s technology. The purpose of CF2T project is to develop a competitive foundation, immerse it as part of a precommercial project and validate the concept in real sea environment. The innovative foundation was designed to decrease construction costs, with modular interfaces to allow an installation in several packages (foundation parts, ballasts, turbine) in order to limit the installation vessel’s crane capacity requirement, which will also reduce installation costs. A concrete foundation with steel footings and turbine bed were considered to lower the manufacturing costs and increase the foundation durability comparing to currently used steel foundations. RISE Infrastructure and Concrete Technology supported the process of concrete material selection and casting technology. The material design was preceded with numerical analysis of early cracking due to hydration heat development, which indicated that there exists a substantial risk of thermal cracking. Three different variants of concrete mixes complying the design strength and stiffness criteria with low hydration heat were developed concerning various available casting technologies. The mixes were tested for standard concrete properties: compressive and flexural strength, modulus of elasticity, consistency, and shrinkage. The selected materials were submitted to accelerated durability testing including shrinkage and chloride migration. A basic life cycle analysis (LCA) of the concrete material, manufacturing was performed and compared to steel foundation solution to assess the sustainability of the designed structural and material solutions. The innovative concrete foundation and traditional steel foundation with D14 turbines are meant to be monitored with a specially developed sensors and data acquisition system in real sea environment.

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