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Mensah, Rhoda AfriyieORCID iD iconorcid.org/0000-0003-4720-5380
Publikasjoner (10 av 32) Visa alla publikasjoner
Panahi, P., Khorasani, S. N., Mensah, R. A., Das, O. & Neisiany, R. E. (2024). A review of the characterization methods for self-healing assessment in polymeric coatings. Progress in organic coatings, 186, Article ID 108055.
Åpne denne publikasjonen i ny fane eller vindu >>A review of the characterization methods for self-healing assessment in polymeric coatings
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2024 (engelsk)Inngår i: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 186, artikkel-id 108055Artikkel, forskningsoversikt (Fagfellevurdert) Published
sted, utgiver, år, opplag, sider
Elsevier, 2024
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-102438 (URN)10.1016/j.porgcoat.2023.108055 (DOI)001108295600001 ()2-s2.0-85175543977 (Scopus ID)
Merknad

Validerad;2023;Nivå 2;2023-11-15 (hanlid)

Tilgjengelig fra: 2023-11-13 Laget: 2023-11-13 Sist oppdatert: 2024-03-07bibliografisk kontrollert
Gawusu, S., Tando, M. S., Ahmed, A., Jamatutu, S. A., Mensah, R. A., Das, O., . . . Ackah, I. (2024). Decentralized energy systems and blockchain technology: Implications for alleviating energy poverty. Sustainable Energy Technologies and Assessments, 65, Article ID 103795.
Åpne denne publikasjonen i ny fane eller vindu >>Decentralized energy systems and blockchain technology: Implications for alleviating energy poverty
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2024 (engelsk)Inngår i: Sustainable Energy Technologies and Assessments, ISSN 2213-1388, E-ISSN 2213-1396, Vol. 65, artikkel-id 103795Artikkel, forskningsoversikt (Fagfellevurdert) Published
sted, utgiver, år, opplag, sider
Elsevier Ltd, 2024
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-105404 (URN)10.1016/j.seta.2024.103795 (DOI)2-s2.0-85191295599 (Scopus ID)
Merknad

Validerad;2024;Nivå 2;2024-05-13 (hanlid)

Tilgjengelig fra: 2024-05-13 Laget: 2024-05-13 Sist oppdatert: 2024-05-13bibliografisk kontrollert
Mensah, R. A., Wang, D., Shanmugam, V., Sas, G., Försth, M. & Das, O. (2024). Fire behaviour of biochar-based cementitious composites. Composites Part C: Open Access, 14, Article ID 100471.
Åpne denne publikasjonen i ny fane eller vindu >>Fire behaviour of biochar-based cementitious composites
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2024 (engelsk)Inngår i: Composites Part C: Open Access, ISSN 2666-6820, Vol. 14, artikkel-id 100471Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The study aimed to test the hypothesis that biochar's unique properties, such as its microporous structure, can enhance concrete's resilience to high temperatures. Despite expectations of reduced crack formation and enhanced fire resistance, the experimental results revealed a limited impact on concrete's fire behaviour. The investigation involved the use of two biochar types, fine and coarse biochar as replacements for cement and aggregates, respectively. Fine biochar exhibited higher water absorption and Young's modulus than coarse biochar, but both resisted ignition at 35 kW/m2 radiative heat flux and had peak heat release rates below 40 kW/m2. Incorporating these biochars at varying weight percentages (10, 15, and 20 wt.%) into concrete led to a gradual decline in compressive and tensile strength due to reduced binding ability with increased biochar content. Exposure to 1000 °C compromised mechanical properties across all the samples. However, the biochar concrete maintained compressive strength (compared to the control) with up to 20 wt.% biochar as a fine aggregate substitute after exposure to 600 °C, and as a cement replacement after exposure to 200 °C. This substitution also yielded a significant reduction in CO2 emissions (50 % reduction as the biochar loading amount doubled) from concrete manufacturing, showcasing biochar's potential for sustainable construction practices. Despite not fully supporting the initial hypothesis, the study demonstrated biochar's viability in reducing carbon footprint while maintaining concrete strength under certain fire conditions.

sted, utgiver, år, opplag, sider
Elsevier, 2024
Emneord
Biochar concrete, Elevated temperatures, Mechanical properties
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-105626 (URN)10.1016/j.jcomc.2024.100471 (DOI)2-s2.0-85193825752 (Scopus ID)
Forskningsfinansiär
Brandforsk, 322-003Swedish Research Council Formas, 2022-00676Svenska Byggbranschens Utvecklingsfond (SBUF), 14062
Merknad

Validerad;2024;Nivå 1;2024-05-30 (signyg);

Full text license: CC BY

Tilgjengelig fra: 2024-05-30 Laget: 2024-05-30 Sist oppdatert: 2024-05-30bibliografisk kontrollert
Birdsong, B. K., Wu, Q., Hedenqvist, M. S., Capezza, A. J., Andersson, R. L., Svagan, A. J., . . . Olsson, R. T. (2024). Flexible and fire-retardant silica/cellulose aerogel using bacterial cellulose nanofibrils as template material. Materials Advances
Åpne denne publikasjonen i ny fane eller vindu >>Flexible and fire-retardant silica/cellulose aerogel using bacterial cellulose nanofibrils as template material
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2024 (engelsk)Inngår i: Materials Advances, E-ISSN 2633-5409Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
Abstract [en]

This study explores the possibility of using various silsesquioxane precursors such as (3-aminopropyl) triethoxysilane (APTES), methyltrimethoxysilane (MTMS), and tetraethyl orthosilicate (TEOS) to produce silsesquioxane-bacterial cellulose nanofibre (bCNF) aerogels. Each precursor allowed to customize the aerogel properties, leading to unique properties suitable for various applications requiring lightweight insulative materials. When utilizing APTES as the silsesquioxane precursor, an aerogel capable of over 90% recovery after compression was formed, making them suitable for flexible applications. When MTMS was used as the precursor, the aerogel retained some compression recovery (80%) but had the added property of superhydrophobicity with a contact angle over 160° due to the presence of CH3 functional groups, enabling water-repellence. Finally, TEOS allowed for excellent thermal insulative properties with a low Peak Heat Release Rate (PHRR), making it a promising candidate for fire-resistant applications. The customization of these aerogel materials was attributed to a combination of the chemical composition of the silsesquioxane precursors and the morphology of the coated bacterial cellulose nanofibres (bCNF), such as CH3 groups found in MTMS enabled for superhydrophobicity. Differences in morphology, such as uniform and smooth silsesquioxane coatings when using APTES or a “pearl-necklace” morphology using TEOS, enabled either compression recovery and flexibility or low thermal conduction. This investigation of silsesquioxane-bCNF provides a good understanding of the importance of the choice of precursor effect on insulating aerogel properties.

sted, utgiver, år, opplag, sider
Royal Society of Chemistry, 2024
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-104509 (URN)10.1039/d3ma01090b (DOI)2-s2.0-85185472680 (Scopus ID)
Merknad

Funder: Swedish Research Council (VR 2019-05650);

Full text license: CC BY

Tilgjengelig fra: 2024-03-07 Laget: 2024-03-07 Sist oppdatert: 2024-03-07
Gao, Z., Cai, J., Jiang, L., Mensah, R. A. & Fan, C. (2024). Investigation on the natural smoke exhaust performance by vertical shaft in tunnel fires under different ambient pressures. Indoor + Built Environment
Åpne denne publikasjonen i ny fane eller vindu >>Investigation on the natural smoke exhaust performance by vertical shaft in tunnel fires under different ambient pressures
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2024 (engelsk)Inngår i: Indoor + Built Environment, ISSN 1420-326X, E-ISSN 1423-0070Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
sted, utgiver, år, opplag, sider
Sage Publications, 2024
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-105211 (URN)10.1177/1420326X241242728 (DOI)2-s2.0-85190457429 (Scopus ID)
Merknad

Funder: National Natural Science Foundation of China (52076198); Excellent Youth Foundation of Henan Scientific Committee (222300420078); Science and Technology Program of Hunan Provincial Department of Transportation (202122); Key Research and Development Program of Hunan Province (2022SK2093); National Supercomputing Center in Zhengzhou

Tilgjengelig fra: 2024-05-02 Laget: 2024-05-02 Sist oppdatert: 2024-05-02
Wang, D., Luo, B., Deng, J., Feng, Q., Zhang, W., Deng, C., . . . Das, O. (2024). Optimized fire resistance of alkali-activated high-performance concrete by steel fiber. Journal of thermal analysis and calorimetry (Print)
Åpne denne publikasjonen i ny fane eller vindu >>Optimized fire resistance of alkali-activated high-performance concrete by steel fiber
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2024 (engelsk)Inngår i: Journal of thermal analysis and calorimetry (Print), ISSN 1388-6150, E-ISSN 1588-2926Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
Abstract [en]

The behavior of alkali-activated ultra-high-performance concrete (A-UHPC) at elevated temperatures is unknown. This study addresses this gap by investigating the behavior of A-UHPC under varying temperatures with steel fiber additions (1%, 2%, and 3%), and considering target temperatures (20 °C, 200 °C, 400 °C, 600 °C, and 800 °C) as design variables. As the results, A-UHPC with steel fibers showed improved fire resistance, suffering less compressive strength loss at 800 °C than fiber-free A-UHPC. High temperatures initially optimized A-UHPC’s microstructure at 200 °C but later caused damage through microstructure propagation. Steel fibers enhanced A-UHPC’s ductility, resulting in ductile failure even at 800 °C. A-UHPC exhibited a unique mechanical degradation pattern under elevated temperatures, distinct from ordinary cement-based concrete. Empirical models accurately predicted its behavior, offering valuable insights for engineers dealing with heavy loads and high temperatures.

sted, utgiver, år, opplag, sider
Springer Nature, 2024
Emneord
Alkali-activated materials, Fire resistance, Microstructures, Steel fibers
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-105702 (URN)10.1007/s10973-024-13238-w (DOI)2-s2.0-85193210757 (Scopus ID)
Merknad

Funder: Open Fund of Hunan Engineering Research Center for Intelligent Construction of Fabricated Retaining Structures (22K02)

Tilgjengelig fra: 2024-05-31 Laget: 2024-05-31 Sist oppdatert: 2024-05-31
Gawusu, S., Jamatutu, S. A., Zhang, X., Moomin, S. T., Ahmed, A., Mensah, R. A., . . . Ackah, I. (2024). Spatial analysis and predictive modeling of energy poverty: insights for policy implementation. Environment, Development and Sustainability
Åpne denne publikasjonen i ny fane eller vindu >>Spatial analysis and predictive modeling of energy poverty: insights for policy implementation
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2024 (engelsk)Inngår i: Environment, Development and Sustainability, ISSN 1387-585X, E-ISSN 1573-2975Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
Abstract [en]

Understanding and alleviating energy poverty is critical for sustainable development. This study harnesses a suite of Machine Learning (ML) algorithms to predict Multidimensional Energy Poverty Index (MEPI) and to highlight the spatial distribution of energy poverty. We assess the predictive accuracy of Random Forest (RF), Support Vector Machine (SVM), Artificial Neural Network (ANN), Multiple Linear Regression (MLR), and XGBoost models. The RF model outperforms others, achieving an R2 value of 0.92 and a Pearson Correlation Coefficient (PCC) of 0.97 on the testing dataset, indicative of a highly accurate prediction capability. XGBoost also demonstrates strong predictive power with corresponding values of 0.88 and 0.94, respectively. Our spatial analysis, revealing significant clustering of energy poverty with a Global Moran’s I value of 150.39, indicates that energy poverty is not only geographically concentrated but also intricately linked to socio-economic factors such as income levels, access to education, and nutritional status. These insights underscore the necessity of region-specific and socio-economically informed policy interventions. The results inform targeted interventions, particularly highlighting the critical roles of education and nutrition in mitigating energy poverty. The RF model’s accuracy rate of 92% on the testing set suggests that improvements in these sectors could significantly influence MEPI scores. The integration of ML and spatial analysis offers a nuanced and actionable understanding of energy poverty, paving the way for targeted, evidence-based policy formulation aimed at achieving SDG7: ensuring access to affordable, reliable, sustainable, and modern energy for all.

sted, utgiver, år, opplag, sider
Springer Nature, 2024
Emneord
Artificial Neural Networks, Energy poverty, Geographic Information Systems, Machine learning, MEPI, Predictive modeling, Spatial analysis
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-105705 (URN)10.1007/s10668-024-05015-4 (DOI)2-s2.0-85193300716 (Scopus ID)
Tilgjengelig fra: 2024-05-31 Laget: 2024-05-31 Sist oppdatert: 2024-05-31
Raja, P., Murugan, V., Ravichandran, S., Behera, L., Mensah, R. A., Mani, S., . . . Das, O. (2023). A Review of Sustainable Bio-Based Insulation Materials for Energy-Efficient Buildings. Macromolecular materials and engineering, 308(10), Article ID 2300086.
Åpne denne publikasjonen i ny fane eller vindu >>A Review of Sustainable Bio-Based Insulation Materials for Energy-Efficient Buildings
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2023 (engelsk)Inngår i: Macromolecular materials and engineering, ISSN 1438-7492, E-ISSN 1439-2054, Vol. 308, nr 10, artikkel-id 2300086Artikkel, forskningsoversikt (Fagfellevurdert) Published
Abstract [en]

The surge towards a sustainable future in the construction industry requires the use of bio-based insulation materials as an alternative to conventional ones for improving energy efficiency in structures. In this article, the features of bio-based insulation materials, including their thermal conductivities, moisture buffering value, fire performance, and life cycle evaluations are examined. It is clear from the review that pre- and post-treatment of the bio-based materials used for insulation materials optimize their properties. The life cycle analysis reveals a significant reduction in global warming potential (GWP) compared to conventional foams. In addition, it is envisaged that producing bio-based insulation materials on a larger scale will further decrease the net GWP. The article, therefore, proposes the implementation of policies that will promote the commercialization of bio-based insulation materials.

sted, utgiver, år, opplag, sider
John Wiley and Sons Inc, 2023
Emneord
construction, degradable materials, fire reactions, insulation, renewable sources
HSV kategori
Forskningsprogram
Byggkonstruktion
Identifikatorer
urn:nbn:se:ltu:diva-97967 (URN)10.1002/mame.202300086 (DOI)000995935600001 ()2-s2.0-85160288253 (Scopus ID)
Merknad

Validerad;2023;Nivå 2;2023-11-01 (joosat);

Licens fulltext: CC BY License

Tilgjengelig fra: 2023-06-07 Laget: 2023-06-07 Sist oppdatert: 2024-01-17bibliografisk kontrollert
Das, O., Mensah, R. A., Balasubramanian, K. B., Shanmugam, V., Försth, M., Hedenqvist, M. S., . . . Misra, M. (2023). Functionalised biochar in biocomposites: The effect of fire retardants, bioplastics and processing methods. Composites Part C: Open Access, 11, Article ID 100368.
Åpne denne publikasjonen i ny fane eller vindu >>Functionalised biochar in biocomposites: The effect of fire retardants, bioplastics and processing methods
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2023 (engelsk)Inngår i: Composites Part C: Open Access, E-ISSN 2666-6820, Vol. 11, artikkel-id 100368Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Fire retardants, although can impart fire-safety in polymeric composites, are detrimental to the mechanical properties. Biochar can be used, in conjunction with fire retardants, to create a balance between fire-safety and mechanical performance. It is possible to thermally dope fire retardants into the pores of biochar to make it functionalised. Thus, the current work is intended in identifying a composite having the combination of the most desirable fire retardant, bioplastic, and a suitable processing method. A comparison was made between two fire retardants (lanosol and ammonium polyphosphate), bioplastics (wheat gluten and polyamide 11), and composite processing methods (compression and injection moulding). It was found that wheat gluten containing ammonium polyphosphate-doped biochar made by compression moulding had the best fire-safety properties with the lowest peak heat release rate (186 kW/m2), the highest fire performance index (0.6 m2s/kW), and the lowest fire growth index (1.6 kW/ms) with acceptable mechanical properties compared to the corresponding neat bioplastic. Thus, for gluten-based polymers, the use of ammonium polyphosphate thermally doped into biochar processed by compression moulding is recommended to both simultaneously improve fire-safety and conserve the mechanical strength of the resulting biocomposites.

sted, utgiver, år, opplag, sider
Elsevier, 2023
Emneord
Biochar, Bioplastics, Compression moulding, Fire retardants, Injection moulding
HSV kategori
Forskningsprogram
Byggkonstruktion; Träteknik
Identifikatorer
urn:nbn:se:ltu:diva-98229 (URN)10.1016/j.jcomc.2023.100368 (DOI)001016720900001 ()2-s2.0-85160716623 (Scopus ID)
Forskningsfinansiär
Brandforsk, 321–002
Merknad

Validerad;2023;Nivå 2;2023-06-13 (hanlid)

Tilgjengelig fra: 2023-06-13 Laget: 2023-06-13 Sist oppdatert: 2024-03-07bibliografisk kontrollert
Lin, C.-F., Karlsson, O., Das, O., Mensah, R. A., Mantanis, G. I., Jones, D., . . . Sandberg, D. (2023). High Leach-Resistant Fire-Retardant Modified Pine Wood (Pinus sylvestris L.) by In Situ Phosphorylation and Carbamylation. ACS Omega, 8(12), 11381-11396
Åpne denne publikasjonen i ny fane eller vindu >>High Leach-Resistant Fire-Retardant Modified Pine Wood (Pinus sylvestris L.) by In Situ Phosphorylation and Carbamylation
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2023 (engelsk)Inngår i: ACS Omega, E-ISSN 2470-1343, Vol. 8, nr 12, s. 11381-11396Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The exterior application of fire-retardant (FR) timber necessitates it to have high durability because of the possibility to be exposed to rainfall. In this study, water-leaching resistance of FR wood has been imparted by grafting phosphate and carbamate groups of the water-soluble FR additives ammonium dihydrogen phosphate (ADP)/urea onto the hydroxyl groups of wood polymers via vacuum-pressure impregnation, followed by drying/heating in hot air. A darker and more reddish wood surface was observed after the modification. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, solid-state 13C cross-polarization magic-angle-spinning nuclear magnetic resonance (13C CP-MAS NMR), and direct-excitation 31P MAS NMR suggested the formation of C–O–P covalent bonds and urethane chemical bridges. Scanning electron microscopy/energy-dispersive X-ray spectrometry suggested the diffusion of ADP/urea into the cell wall. The gas evolution analyzed by thermogravimetric analysis coupled with quadrupole mass spectrometry revealed a potential grafting reaction mechanism starting with the thermal decomposition of urea. Thermal behavior showed that the FR-modified wood lowered the main decomposition temperature and promoted the formation of char residues at elevated temperatures. The FR activity was preserved even after an extensive water-leaching test, confirmed by the limiting oxygen index (LOI) and cone calorimetry. The reduction of fire hazards was achieved through the increase of the LOI to above 80%, reduction of 30% of the peak heat release rate (pHRR2), reduction of smoke production, and a longer ignition time. The modulus of elasticity of FR-modified wood increased by 40% without significantly decreasing the modulus of rupture.

sted, utgiver, år, opplag, sider
American Chemical Society (ACS), 2023
HSV kategori
Forskningsprogram
Träteknik; Byggkonstruktion; Gränsytors kemi
Identifikatorer
urn:nbn:se:ltu:diva-95881 (URN)10.1021/acsomega.3c00146 (DOI)000960080200001 ()37008136 (PubMedID)2-s2.0-85150425157 (Scopus ID)
Forskningsfinansiär
Swedish Research Council Formas, 2021-00818
Merknad

Validerad;2023;Nivå 2;2023-04-21 (joosat);

Funder: OP RDE (Grant no.CZ.02.1.01/0.0/0.0/16_019/0000803); CT WOOD, Luleå University of Technology

Licens fulltext: CC BY License

Tilgjengelig fra: 2023-03-15 Laget: 2023-03-15 Sist oppdatert: 2023-09-22bibliografisk kontrollert
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Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-4720-5380