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Skrifvars, Mikael
Alternative names
Publications (10 of 280) Show all publications
Kopf, S., Åkesson, D., Hakkarainen, M. & Skrifvars, M. (2023). Effect of hydroxyapatite particle morphology on as-spun poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/hydroxyapatite composite fibers. Results in Materials, 20, Article ID 100465.
Open this publication in new window or tab >>Effect of hydroxyapatite particle morphology on as-spun poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/hydroxyapatite composite fibers
2023 (English)In: Results in Materials, ISSN 2590-048X, Vol. 20, article id 100465Article in journal (Refereed) Published
Abstract [en]

Hydroxyapatite (HA) has shown very promising results in hard tissue engineering because of its similarity to bone and hence the capability to promote osteogenic differentiation. While the bioactivity of HA is uncontested, there are still uncertainties about the most suitable hydroxyapatite particle shapes and sizes for textile scaffolds. This study investigates the influence of the shape and size of HA particles on as spun fibers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and HA, their mechanical and thermal properties as well as their influence on the fiber degradation in simulated blood matrix and their capability to mineralize in simulated body fluid. The key findings were that the different HA particles’ size does not affect the melting temperature and still maintains a thermal stability suitable for fiber production. Tensile testing revealed decreased mechanical properties for PHBV/HA as spun fibers, independently of the particle morphology. However, HA particles with 30 nm in width and 100 nm in length at 1 wt% HA loading achieved the highest tenacity and elongation at break amongst all composite fibers with HA. Besides, the Ca/P ratio of their mineralization in simulated body fluid is the closest to the one of mineralized human bone, indicating the most promising bioactivity results of all HA particles studied.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Tissue engineering, Hydroxyapatite (HA), Particle size, Melt spinning, Fiber, Bionanocomposite, Biomimetic, Melt extrusion, Mechanical properties, Degradation, Thermal properties
National Category
Polymer Technologies
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-30988 (URN)10.1016/j.rinma.2023.100465 (DOI)2-s2.0-85173948487 (Scopus ID)
Funder
University of Borås
Available from: 2023-12-12 Created: 2023-12-12 Last updated: 2024-02-01Bibliographically approved
Johansson, M., Skrifvars, M., Kadi, N. & Dhakal, H. N. (2023). Effect of lignin acetylation on the mechanical properties of lignin-poly-lactic acid biocomposites for advanced applications. Industrial crops and products (Print), 202, Article ID 117049.
Open this publication in new window or tab >>Effect of lignin acetylation on the mechanical properties of lignin-poly-lactic acid biocomposites for advanced applications
2023 (English)In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 202, article id 117049Article in journal (Refereed) Published
Abstract [en]

Bioplastics that possess characteristics like durability and low cost are desired for versatile applications in industries such as automotive manufacturing, marine transport manufacturing, aerospace applications, and the building industry. The automotive industry is an example of an industry that is now shifting towards a more focused approach addressing the issue concerning sustainability and the development of sustainable material. To achieve a lightweight and sustainable construction, one of the methods used by the automotive original equipment manufacturers is by substituting conventional fossil-based, non-renewable composites, and metallic materials with a bio-based alternative. One of the drawbacks with biobased polymers can be the poor interfacial adhesion, leading to poor mechanical properties when compares to conventional material. The aim of this research is to investigate if a low-cost by-product could be used as a component in a composite matrix material in the automotive industry to reduce the final weight and increase the non-petrochemical material usage of composite material without compromising the thermal and mechanicals properties demanded. In this research, lignin was chemically altered by esterification the functional groups to increase the compatibility with polylactic acid. The esterification was performed with the use of acetic acid anhydride and pyridine. To evaluate and determine the esterification, Fourier transform Infrared Spectroscopy was used. By blending the modified lignin with polylactic acid the intention was to improve the thermomechanical properties and the interfacial linkage between the components. The effects of lignin acetylation on the tensile properties, impact strength, and thermal stability and moisture repellence behaviour were investigated. According to the experimental results the modification of lignin, increased the impact strength for all the blends containing acetylated lignin compares to pristine lignin. The largest increase observed was for blends containing 20 wt% acetylated lignin and polylactic acid, which resulted in a 74% improvement compared with the blend composed of pristine lignin and polylactic acid. Similarly, the thermal stability was improved significantly with acetylation of the lignin. Moreover, the moisture repellence behaviour was also increased. The reason for the improved properties can be explained by the better interfacial compatibility between lignin and polylactic acid matrix. An increased thermal stability and a moisture repellent behaviour of the blends containing chemically modified lignin could be observed when compared with neat polylactic acid which makes the acetylation treatment of lignin a possible approach for the future of biocomposite production. 

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Acetylation, Biocomposites, Impact toughness, Lignin, Polylactic acid, Costs, Lactic Acid, Mixing, Polyesters, Automotive industry, Blending, Construction industry, Esters, Fourier transform infrared spectroscopy, Sustainable development, Thermodynamic stability, Weathering, %moisture, Advanced applications, Automotive manufacturing, Bio-plastics, Biocomposite, Composites material, Low-costs, Modified lignins, Poly lactic acid, byproduct, chemical reaction, composite, equipment, mechanical property, sustainability, Impact strength
National Category
Composite Science and Engineering
Identifiers
urn:nbn:se:hb:diva-30307 (URN)10.1016/j.indcrop.2023.117049 (DOI)001023027100001 ()2-s2.0-85162265698 (Scopus ID)
Available from: 2023-08-14 Created: 2023-08-14 Last updated: 2024-02-01Bibliographically approved
Arya, M., Malmek, E.-M., Ecoist, T. K., Pettersson, J., Skrifvars, M. & Khalili, P. (2023). Enhancing Sustainability: Jute Fiber-Reinforced Bio-Based Sandwich Composites for Use in Battery Boxes. Polymers, 15(18), Article ID 3842.
Open this publication in new window or tab >>Enhancing Sustainability: Jute Fiber-Reinforced Bio-Based Sandwich Composites for Use in Battery Boxes
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2023 (English)In: Polymers, E-ISSN 2073-4360, Vol. 15, no 18, article id 3842Article in journal (Refereed) Published
Abstract [en]

The rising industrial demand for environmentally friendly and sustainable materials has shifted the attention from synthetic to natural fibers. Natural fibers provide advantages like affordability, lightweight nature, and renewability. Jute fibers’ substantial production potential and cost-efficiency have propelled current research in this field. In this study, the mechanical behavior (tensile, flexural, and interlaminar shear properties) of plasma-treated jute composite laminates and the flexural behavior of jute fabric-reinforced sandwich composites were investigated. Non-woven mat fiber (MFC), jute fiber (JFC), dried jute fiber (DJFC), and plasma-treated jute fiber (TJFC) composite laminates, as well as sandwich composites consisting of jute fabric bio-based unsaturated polyester (UPE) composite as facing material and polyethylene terephthalate (PET70 and PET100) and polyvinyl chloride (PVC) as core materials were fabricated to compare their functional properties. Plasma treatment of jute composite laminate had a positive effect on some of the mechanical properties, which led to an improvement in Young’s modulus (7.17 GPa) and tensile strength (53.61 MPa) of 14% and 8.5%, respectively, as well as, in flexural strength (93.71 MPa) and flexural modulus (5.20 GPa) of 24% and 35%, respectively, compared to those of JFC. In addition, the results demonstrated that the flexural properties of jute sandwich composites can be significantly enhanced by incorporating PET100 foams as core materials. 

Keywords
bio-based sandwich composites, composite laminate, jute fiber, mechanical behavior, plasma treatment
National Category
Composite Science and Engineering Bio Materials
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-30675 (URN)10.3390/polym15183842 (DOI)001075851500001 ()2-s2.0-85172909059 (Scopus ID)
Available from: 2023-10-23 Created: 2023-10-23 Last updated: 2024-01-17Bibliographically approved
Uusi-Tarkka, E.-K., Skrifvars, M., Khalili, P., Heräjärvi, H., Kadi, N. & Haapala, A. (2023). Mechanical and Thermal Properties of Wood-Fiber-Based All-Cellulose Composites and Cellulose-Polypropylene Biocomposites. Polymers, 15(3), Article ID 475.
Open this publication in new window or tab >>Mechanical and Thermal Properties of Wood-Fiber-Based All-Cellulose Composites and Cellulose-Polypropylene Biocomposites
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2023 (English)In: Polymers, E-ISSN 2073-4360, Vol. 15, no 3, article id 475Article in journal (Refereed) Published
Abstract [en]

This article explores wood-fiber-based fabrics containing Lyocell yarn in the warp and Spinnova–Lyocell (60%/40%) yarn in the weft, which are used to form unidirectional all-cellulose composites (ACC) through partial dilution in a NaOH–urea solution. The aim is to investigate the role of the yarn orientation in composites, which was conducted by measuring the tensile properties in both the 0° and 90° directions. As a reference, thermoplastic biocomposites were prepared from the same fabrics, with biobased polypropylene (PP) as the matrix. We also compared the mechanical and thermal properties of the ACC and PP biocomposites. The following experiments were carried out: tensile test, TGA, DSC, DMA, water absorption test and SEM. The study found no significant difference in tensile strength regarding the Spinnova–Lyocell orientation between ACC and PP biocomposites, while the composite tensile strength was clearly higher in the warp (Lyocell) direction for both composite variants. Elongation at break doubled in ACC in the Lyocell direction compared with the other samples. Thermal analysis showed that mass reduction started at a lower temperature for ACC, but the thermal stability was higher compared with the PP biocomposites. Maximum thermal degradation temperature was measured as being 352 °C for ACC and 466 °C for neat PP, and the PP biocomposites had two peaks in the same temperature range (340–474 °C) as ACC and neat PP combined. ACCs absorbed 93% of their own dry weight in water in just one hour, whereas the PP biocomposites BC2 and BC4 absorbed only 10% and 6%, respectively. The study highlights the different properties of ACC and PP reference biocomposites that could lead to further development and research of commercial applications for ACC.

Keywords
ACC, laminate, mechanical performance, NaOH–urea solvent, single-polymer composite, sustainability, textile structures, thermal analysis, wood fibers
National Category
Composite Science and Engineering
Research subject
Resource Recovery; Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-29466 (URN)10.3390/polym15030475 (DOI)000932882300001 ()2-s2.0-85147935299 (Scopus ID)
Available from: 2023-02-23 Created: 2023-02-23 Last updated: 2024-01-17Bibliographically approved
Khalili, P., Skrifvars, M., Dhakal, H. N., Dashatan, S. H., Danielsson, M. & Gràcia, A. F. (2023). Mechanical Properties of Bio-Based Sandwich Composites Containing Recycled Polymer Textiles. Polymers, 15(18), 1-14, Article ID 3815.
Open this publication in new window or tab >>Mechanical Properties of Bio-Based Sandwich Composites Containing Recycled Polymer Textiles
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2023 (English)In: Polymers, E-ISSN 2073-4360, Vol. 15, no 18, p. 1-14, article id 3815Article in journal (Refereed) Published
Abstract [en]

In this paper, sandwich composites were produced by compression moulding techniques, and they consisted of regenerated cellulose fabric (rayon) and bio-based polypropylene (PP) to form facings, while virgin and recycled polyamide (PA) textiles were used as core materials. To compare the mechanical performance between sandwich composites and typical composite designs, a control composite was produced to deliver the same weight and fiber mass fraction from rayon and PP. To evaluate the influence of recycled textile on the mechanical properties of the composites, a series of flexural, low velocity impact (LVI) and tensile tests were performed. It was found that the incorporation of thicker PA textile enhanced the bending stiffness by two times and the peak flexural force by 70% as compared to those of control. Substitution of a layer of recycled textile for two layers of rayon provided a good level of impact energy absorption capacity (~28 J) and maximum force (~4893–5229 N). The tensile strength of the four sandwich composites was reported to be in the range of 34.20 MPa and 46.80 MPa. This value was 91.90 for the control composite. The 2D cross-section slices of the composite specimens did not show any evidence of fiber tow debonding, fiber bundle splitting, or delamination.

Keywords
impact behaviour, mechanical properties, regenerated cellulose, sandwich composites
National Category
Polymer Technologies
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-30676 (URN)10.3390/polym15183815 (DOI)001074042700001 ()2-s2.0-85172883276 (Scopus ID)
Funder
Vinnova, 202202576
Available from: 2023-10-23 Created: 2023-10-23 Last updated: 2024-02-01Bibliographically approved
Akbari, S., Root, A., Skrifvars, M., Kumar Ramamoorthy, S. & Åkesson, D. (2023). Novel Bio-based Branched Unsaturated Polyester Resins for High-Temperature Applications. Journal of Polymers and the Environment
Open this publication in new window or tab >>Novel Bio-based Branched Unsaturated Polyester Resins for High-Temperature Applications
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2023 (English)In: Journal of Polymers and the Environment, ISSN 1566-2543, E-ISSN 1572-8919Article in journal (Refereed) Published
Abstract [en]

Unsaturated polyester resins, one of the most important thermosets, are invariably produced from oil-based monomers. Their application is limited in areas where high thermal stability is required due to their low Tg. Besides, these resins contain 30–40% hazardous styrene as a reactive solvent. Therefore, developing bio-based solventless unsaturated polyester resin with medium to high thermomechanical properties compared to petrochemical-based counterparts is important. In order to achieve this, a series of branched bio-based unsaturated polyester resins were synthesized using bulk polymerization method in two steps. In the first step, four different intermediates were prepared by reacting glycerol (as a core molecule) with either isosorbide (diol), 1,3-propanediol (diol), 2,5-furandicarboxylic acid (saturated diacid), or adipic acid (saturated diacid). In the second step, the branched intermediate was end capped with methacrylic anhydride to introduce reactive sites for cross-linking on the branch ends. The chemical structure of the resins was characterized by 13C-NMR. FT-IR confirmed the polycondensation reaction in the first step and the end functionalization of the resins with methacrylic anhydride in the second step. The effect of 2,5-furandicarboxylic acid and isosorbide on thermomechanical and thermal properties was investigated using dynamic mechanical analysis, differential scanning calorimetry, and thermo-gravimetric analysis. Results indicated that 2,5-furandicarboxylic acid based resins had superior thermomechanical properties compared to a commercial reference unsaturated polyester resin, making them promising resins for high-temperature composite applications. For example, the resin based on 2,5-furandicarboxylic acid and isosorbide and the resin based on 2,5-furandicarboxylic acid and 1,3-propanediol gave glass transition temperatures of 173 °C and 148 °C, respectively. Although the synthesized 2,5-furandicarboxylic acid based resins had higher viscosity (22.7 Pas) than conventional unsaturated polyester (0.4–0.5 Pas) at room temperature, preheated resins can be used for making high-temperature-tolerance fiber-reinforced composite. 

Keywords
Bio-based unsaturated polyester resins, Isosorbide, 2, 5-Furandicarboxylic acid, High-Tg
National Category
Polymer Chemistry
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-30990 (URN)10.1007/s10924-023-03112-5 (DOI)001103740600001 ()2-s2.0-85176301334 (Scopus ID)
Available from: 2023-12-12 Created: 2023-12-12 Last updated: 2024-02-01Bibliographically approved
Khalili, P., Skrifvars, M., Dhakal, H. N. & Jiang, C. (2023). Regenerated cellulose fabric reinforced bio-based polypropylene sandwich composites: fabrication, mechanical performance and analytical modelling. Journal of Materials Research and Technology, 22, 3423-3435
Open this publication in new window or tab >>Regenerated cellulose fabric reinforced bio-based polypropylene sandwich composites: fabrication, mechanical performance and analytical modelling
2023 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 22, p. 3423-3435Article in journal (Refereed) Published
Abstract [en]

Sandwich composites were fabricated successfully with the balsa wood as core material and regenerated cellulose fabric bio-based polypropylene (PP) composite skins. The regenerated cellulose fabric PP composites were produced using two different methods: the conventional stacking lay-up and directly using PP pellets. Sandwich composites were made using the hot press equipment with the customized mold. The sandwich composite system and bio-composite laminate were designed to achieve very close weight to compare the key mechanical properties that each design can bear. It was evidenced from the experimental results that 416% increase in the bending load bearing property of the part can be obtained when sandwich structure was used. These experimental results were in close agreement with one of the analytical modelling utilised. The drop weight impact test results demonstrated that the sandwich specimen is capable of withstanding more than 6 kN load and absorbing the impact energy of 28.37 J.

Keywords
Balsa, Bio-based sandwich composites, Man-made cellulose fabric, Mechanical properties
National Category
Composite Science and Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-29457 (URN)10.1016/j.jmrt.2022.12.186 (DOI)000975581500001 ()2-s2.0-85147671820 (Scopus ID)
Available from: 2023-02-20 Created: 2023-02-20 Last updated: 2024-02-01Bibliographically approved
Ehsanimehr, S., Sonnier, R., Badawi, M., Ducos, F., Kadi, N., Skrifvars, M., . . . Vahabi, H. (2023). Sustainable Flame-Retardant Flax Fabrics by Engineered Layer-by-Layer Surface Functionalization with Phytic Acid and Polyethylenimine. Fire technology
Open this publication in new window or tab >>Sustainable Flame-Retardant Flax Fabrics by Engineered Layer-by-Layer Surface Functionalization with Phytic Acid and Polyethylenimine
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2023 (English)In: Fire technology, ISSN 0015-2684, E-ISSN 1572-8099Article in journal (Refereed) Published
Abstract [en]

New generation of mission-oriented fabrics meets advanced requirements; such as electrical conductivity, flame retardancy, and anti-bacterial properties. However, sustainability concerns still are on-demand in fabrication of multi-functional fabrics. In this work, we used a bio-based phosphorus molecule (phytic acid, PA) to reinforce flax fabrics against flame via layer-by-layer consecutive surface modification. First, the flax fabric was treated with PA. Then, polyethylenimine (PEI) was localized above it to create negative charges, and finally PA was deposited as top-layer. Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and inductively-coupled plasma atomic emission spectrometry (ICP-AES) proved successful chemical treatment. Pyrolysis-combustion flow calorimetry (PCFC) showed significant drop by about 77% in the peak of heat release rate (pHRR) from 215 W/g for untreated to 50 W/g for treated flax fabric. Likewise, the total heat release (THR) decreased by more than three times from 11 to 3.2 kJ/g. Mechanical behavior of the treated flax fabric was completely different from untreated flax fabrics, changing from almost highly-strengthened behavior with short elongation at break to a rubber-like behavior with significantly higher elongation at break. Surface friction resistance was also improved, such that the abrasion resistance of the modified fabrics increased up to 30,000 rub cycles without rupture.   

National Category
Materials Engineering
Research subject
Textiles and Fashion (General); Resource Recovery
Identifiers
urn:nbn:se:hb:diva-29583 (URN)10.1007/s10694-023-01387-7 (DOI)000956756000001 ()2-s2.0-85150906609 (Scopus ID)
Available from: 2023-03-29 Created: 2023-03-29 Last updated: 2023-04-13Bibliographically approved
Kopf, S., Åkesson, D. & Skrifvars, M. (2023). Textile Fiber Production of Biopolymers - A Review of Spinning Techniques for Polyhydroxyalkanoates in Biomedical Applications. Paper presented at Volume 63, 2023. Polymer reviews, 200-245
Open this publication in new window or tab >>Textile Fiber Production of Biopolymers - A Review of Spinning Techniques for Polyhydroxyalkanoates in Biomedical Applications
2023 (English)In: Polymer reviews, ISSN 1558-3724, p. 200-245Article, review/survey (Refereed) Published
Abstract [en]

The superior biocompatibility and biodegradability of polyhydroxyalkanoates (PHAs) compared to man-made biopolymers such as polylactic acid promise huge potential in biomedical applications, especially tissue engineering (TE). Textile fiber-based TE scaffolds offer unique opportunities to imitate the anisotropic, hierarchical, or strain-stiffening properties of native tissues. A combination of PHAs' enhanced biocompatibility and fiber-based TE scaffolds could improve the performance of TE scaffolds. However, the PHAs' complex crystallization behavior and the resulting intricate spinning procedures remain a challenge. This review focuses on discussing the developments in PHA melt and wet spinning, their challenges, process parameters, and fiber characteristics while revealing the lack of an in-depth fiber characterization of wet-spun fibers compared to melt-spun filaments, leading to squandered potential in scaffold development. Additionally, the biomedical application of PHAs other than poly-4-hydroxybutyrate is hampered by a failure of polymer purity to meet the requirements for biomedical applications.

Place, publisher, year, edition, pages
Taylor & Francis, 2023
Keywords
Biopolymers, polyhydroxyalkanoate, fiber, tissue engineering, processing, X-RAY-DIFFRACTION, MECHANICAL-PROPERTIES, POLY(3-HYDROXYBUTYRATE) FIBERS, STERILIZATION TECHNIQUES, ENZYMATIC DEGRADATION, NUCLEATING-AGENTS, POLYMER FIBERS, BORON-NITRIDE, CRYSTALLIZATION, SCAFFOLDS
National Category
Polymer Technologies Polymer Chemistry
Identifiers
urn:nbn:se:hb:diva-27964 (URN)10.1080/15583724.2022.2076693 (DOI)000800499300001 ()2-s2.0-85131173023 (Scopus ID)
Conference
Volume 63, 2023
Available from: 2022-06-07 Created: 2022-06-07 Last updated: 2024-01-16Bibliographically approved
de Sousa, G. S., Kalantar Mehrjerdi, A., Skrifvars, M. & d'Almeida, J. R. (2023). Thermo‐mechanical properties of polyethylene composites filled with soapstone waste. Journal of Applied Polymer Science, Article ID e55017.
Open this publication in new window or tab >>Thermo‐mechanical properties of polyethylene composites filled with soapstone waste
2023 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, article id e55017Article in journal (Refereed) Epub ahead of print
Abstract [en]

In this study, soapstone waste originated from craftsmanship activities was used as an alternative filler (0–30 wt%) for a high-density polyethylene (PE) matrix. The aim of this paper is to understand the effect of the filler particles on crystallinity, thermal stability and thermo-mechanical properties of this newly developed composite material. Physico-chemical characterization was performed by x-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. Thermogravimetric analysis (TGA), oxidation induction time (OIT) and dynamic mechanical thermal analysis (DMA) were performed to assess the effect of the filler on the themo-mechanical properties of PE. Thermal stability, measured by TGA, was enhanced, while OIT values reduced with filler content. A significant increase on the storage modulus of the composites (up to 148% in comparison with unfilled PE) was observed and this reinforcing effect was even more prominent at higher temperatures. XRD analysis revealed that the degree of crystallinity improved significantly with soapstone loading, which explains the substantial increase in stiffness observed. Increased crystallinity is also associated with higher strength, reduced residual stress, and better dimensional stability of end products, which can be particularly attractive for pressure pipe applications. 

Place, publisher, year, edition, pages
John Wiley & Sons, 2023
Keywords
catalysts, copolymers, emulsion polymerization, morphology, nanoparticles, nanowires, and nanocrystals
National Category
Ceramics
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-31141 (URN)10.1002/app.55017 (DOI)001124723600001 ()2-s2.0-85179988180 (Scopus ID)
Available from: 2024-01-08 Created: 2024-01-08 Last updated: 2024-02-01Bibliographically approved
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