RISE – Research Institutes of Sweden
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Heat strain in professional firefighters : physiological responses to a simulated smoke dive in extremely hot environments and the subsequent recovery phase
No full textFirefighters risk heat strain during occupational tasks when exposed to extremely hot environmental conditions and performing high-intensity work. Relevant training scenarios are there-fore essential. This study investigated the effect of a single simulated smoke dive and the following recovery phase on physiological and perceptual responses. Nineteen professional male firefighters (43 ± 8 yr) performed a 2-min stair walk and a15-min simulated smoke dive in a two-floor heat chamber (110°C to 272°C) (HEAT), followed by a 5-min stair walk outside the heat chamber. Heart rate (HR), gastrointestinal temperature (Tgi) and skin temperatures were registered continuously during the test. The Tgi increased significantly from the start (37.5 ± 0.3°C) to the end of HEAT (38.4 ± 0.4°C) and further increased after the heat exposure (39.6 ± 0.5°C). The HR also increased significantly from the start (92 ± 14 bpm) to the end of HEAT (185 ± 13 bpm) and increased after the heat exposure to a maximum of 190 ± 13 bpm. The simulated smoke dive induced high physiological strain on the firefighters, and the increase in Tgi and HR after the hot exposure must be considered during live fire events when repeated smoke dives are required. The work has been conducted as part of the Fire Research and Innovation Centre (FRIC), which is funded by the Research Council of Norway (program BRANNSIKKERHET, project number 294649) and FRIC partners. </p
Resultater fra brannforsøk med to ulike typer brannbeskyttelse av EPS-isolasjon i vegg- og takkonstruksjon
No full textDenne rapporten oppsummerer resultater fra forskning utført i prosjekt 3.1 Novel construction products i forskningssenteret Fire Research and Innovation Centre (FRIC). Det overordnede målet med prosjektet er å undersøke hvordan nyere konstruksjonsmaterialer og produkter virker inn på brannsikkerheten i bygninger, å utvikle eksperimentelle og teoretiske metoder for å måle denne innvirkningen, samt å utarbeide brannsikre konstruksjonsoppbygninge
Asymmetric Additions Empowered by OrganoCatalysts, Metal Catalysts, and Deep Natural Eutectic Solvents (NADES)
No full textThis article is a history of an industrial-academic partnership that started almost two decades ago and details the evolution of a relationship between a small academic research group and a spin-out company located in Portugal. Their activities have ranged from the development of new metal-based catalytic systems for asymmetric epoxidations, allylic alkylations, and arylations to the development of novel cinchona-based organocatalysts for asymmetric hydrosilylations and Michael additions. Current common interests are centered on the development of novel chiral Natural Deep Eutectic Solvent systems, which they are investigating in different types of reaction systems.EPC acknowledges the Fundac\u0327a\u0303o para a Cie\u0302ncia e a Tecnologia (FCT) for funding through the strategic project to LAQV-REQUIMTE (FCT/MCTES; UIDB/50006/2020|UIDP/50006/2020). AJB acknowledges FCT for funding through the strategic project UIDB/00313/2020 to Coimbra Chemistry Centre\u2013Institute of Molecular Sciences (CQC-IMS).</p
Examining property and neighborhood effects on perceived safety in urban environments : Proximity to square and heights of buildings
No full textResidents’ perceived safety is key to improving livelihoods and reducing disparities between neighborhoods in Sweden. Neighborhood interventions may be more cost-effective than individual-level interventions in addressing major societal issues such as unequal levels of safety between neighborhoods. However, most studies investigating the impact of neighborhood characteristics on perceived safety suffer from either poor data quality, too few respondents per statistical unit, large units of analysis, or a lack of longitudinally collected data. This study aims to fill this gap by combining property-specific longitudinal sociodemographic data with customer satisfaction survey data (N = 147,965) collected between 2013–2014 and 2016–2021 in Gothenburg. Using two multilevel models, we examined the relationship between perceived safety and both property-level and area-level structural characteristics, testing three hypotheses. Consistent with prior research, we find that sociodemographic and urban environmental characteristics influenced perceptions of safety. The multilevel analyses reveal that proximity to the square is associated with lower levels of perceived safety, particularly among residents living within 0–100 m of the square in socioeconomically disadvantaged neighborhoods. Moreover, the results show that living in taller buildings of 10–16 floors is associated with lower levels of safety. The authors would like to thank Helena Bohman at Malmö University and Guilherme Kenjy Chihaya Da Silva at Nord University for the conceptualization and review of this article, and Lars Bankvall at the Framtiden Group who helped us with the data collection. We would like to thank Formas for supporting this work. This project is funded by Formas through the Smart Built Environment programme with grant reference number 2022–00125.</p
Corrosion resistance of additively manufactured aluminium alloys for marine applications
No full textAdditive manufacturing opens new possibilities for designing light-weight structures using aluminium alloys. The microstructure of two Al alloys and their corrosion resistance in NaCl and natural seawater environments were investigated. The newly designed Al-Mn-Cr-Zr based alloy showed a higher corrosion resistance than reference AlSi10Mg alloy in both environments in as printed and heat-treated conditions. The corrosion initiated in the Al matrix along the precipitates in the alloys where the Volta potential difference was found the highest. The coarser microstructure and precipitate composition of the new Al-alloy led to the formation of a resistant passive film which extended the passivity region of the Al-Mn-Cr-Zr alloy compared to the AlSi10Mg alloy. The effect of heat treatment could be seen in the microstructure as more precipitates were found in between the melt pool boundaries, which affected the corrosion initiation and slightly the pitting resistance. Overall, this study shows that a newly designed Al-alloy for additive manufacturing has a suitable corrosion resistance for applications in marine environments. .This study was performed within the European Union\u2019s Horizon 2020 research and innovation programme under grant agreement 820774, through project MANUELA- Additive Manufacturing using Metal Pilot Line. Adj. Prof. Sven Bengtsson at H\u00F6gan\u00E4s AB, Sweden is acknowledged for providing powder. CL and SL acknowledge RISE and AMC for funding. </p
Hur stora är växthusgasutsläppen vid naturvårdsbränning?
No full textHow large are the global warming emissions from prescribed fires in the European boreal? This report addresses emissions of greenhouse gases during prescribed fires, which are done in Sweden for increased biodiversity. Focus is on CO2-emissions during the combustion. There are large instantaneous emissions to the atmosphere. However, the CO2-debt, i.e. the difference in atmospheric CO2 if the burning is conducted or not, decreases rapidly in the years following the burn as carbon is stored in soil and growing plants. The emissions from prescribed burning on protected land can be assessed using field observations of fuel loads, fuel consumption during the fire and post fire plant/litter accretion. The net change in atmospheric CO2 is thereafter calculated from these data sets for different time since fire. Instantaneous emissions are estimated, for a characteristic fuel type, at 14.4 tonnes CO2 per hectare. After only ten years 78 % of this is again fixed in the vegetation on the forest floor, and litter. The same number 20 years post fire is 90 % and at 50 years, 98 %
MEKANISKA EGENSKAPER HOS STORABERGSPRICKOR
No full textExperimentella undersökningar av skjuvegenskaperna hos bergsprickor i hårt berg har generellt fokuserat på mindre sprickprover för normalspänningar på upp till 20 MPa, representativa för ett kärnbränsleförvar på ca 400 meters djup. Vid stora sprickprover har skjuvegenskaperna generellt bestämts för låga spänningar, på någon eller några MPa. För att få en förståelse för inverkan av sprickornas storlek för skjuvegenskaperna vid höga normalspänningar är det avgörande att genomföra skjuvförsök på stora bergsprickor (> 200 mm) i hårt berg under höga normalspänningar. I projektet Parameterization of Fractures, POST (2014–2016), studerades skaleffekterna genom in situ-försök, småskaliga skjuvförsök och beräkningssimuleringar. Det konstaterades att laboratorieexperiment under kontrollerade förhållanden och på stora bergprover är nödvändiga för att få tillförlitliga resultat. Det konstaterades också att in-situ-försök är komplexa med stora underliggande osäkerheter och är samtidigt kostsamma. I det pågående projektet POST 2 som startade 2017 har bergsprickor på upp till 500 mm provats i en ny unik laboratorieutrustning, jämte provning av mindre sprickor, vid höga normalspänningar för både CNL och CNS förhållanden och med ny mätteknik. Teknik för att tillverka replikaprover av bergsprickor har utvecklats och provats med syfte att göra lastparameterstudier. Kvaliteten hos geometriavbildningen hos replikaproverna och sprickornas geometrier har uppmätts med högupplöst skanning. I denna artikel presenteras en del av resultaten från projektet. Resultaten från projektet är tillämpbara för andra områden med undermarkskonstruktioner såsom projektering av tunnlar och bergrum för infrastrukturprojekt och gruvor.Experimental investigations of the shear properties of rock fractures in hard rock have generally focused on tests on smaller fracture s for normal stresses of up to 20 MPa, representative of a nuclear waste repository at a depth of about 400 meters. T he shear properties of large fractures determined at experiments have generally been determined at low stresses , of one or more MPa. To gain an understanding of the effect of the size on the shear properties of the fractures at high normal stresses, it is crucial to perform shear experiments on large rock fractures (> 200 mm) in hard rock under high normal stresses. In the project Parameterization of Fractures, POST (2014 2016), the scale effects were studied by in situ experiments, small scale shear experiments and computational simulations. It was found that laboratory experiments under controlled conditions and on large rock samples are necessary to obtain reliable results. It was also found that in situ experiments are complex with large underlying uncertainties and are at the same time costly. In the ongoing POST 2 project, which started in 2017, rock fractures up to 500 mm have been tested in a new unique laboratory equipment, along with test s on smaller fractures , at high normal stress for both CNL and CNS conditions and with new measurement technology. Techniques for producing replica samples of rock fractures have been developed and tested with the aim of making load parameter studies. The quality of the geometry imaging of the replica samples and the geometries of the fractures has been meas ured by high resolution scanning. This article presents some of the results from the project. The results from the project are applicable to other areas with underground construction, such as the design of tunnels and rock caverns for infrastructure projects and mines
Chemical recycling of complex reject streams from the paper industry via thermal and catalytic pyrolysis
No full textPaper-based packaging is a complex multi-material composed of paper (fibers), plastics, and metals, making efficient material recycling complicated. Currently, most of the fibers are recycled into new paper products while the residual material is commonly incinerated. Therefore, to improve the circularity and reduce the fossil dependency chemical recycling is needed. In this study, recycling of the residual materials was evaluated by thermal and catalytic pyrolysis. First, screening tests were performed using five reject materials and four catalysts in an analytical scale and then, a selection of catalyst and reject materials were evaluated in lab-scale followed by a techno-economic assessment. Experimental results indicated that the conversion was more efficient if the reject had high content of plastics compared to fibers, leading to products with increased heating value, higher hydrocarbon yield and less reactive oxygenates compared to the rejects with low plastic ratio. In the thermal pyrolysis 54 % of the weight of the feedstock and 70 wt% of the carbon in the feedstock ended up in a solid organic product (wax) which contained hydrocarbons and alcohols. In the analytical catalytic pyrolysis, HZSM-5 gave the best result in terms of cracking, deoxygenation, and aromatization. Ex-situ catalytic pyrolysis using HZSM-5 resulted in an improved quality of organic liquid with reduced hydrocarbon length as well as deoxygenated and aromatic compounds. The yield of the organic liquid was up to 19 wt% and contained mainly monoaromatics. The techno-economic evaluation showed, for processing 100,000 tons year−1 residual material, the total plant investment and the annual profit are about 29 and 12 million Euros, respectively, if no incentive for treating the residual material.Funding: Packforsk Owners Association</p
Structure-properties relationships of defined CNF single-networks crosslinked by telechelic PEGs
No full textThe high structural anisotropy and colloidal stability of cellulose nanofibrils’ enable the creation of self-standing fibrillar hydrogel networks at very low solid contents. Adding methacrylate moieties on the surface of TEMPO oxidized CNFs allows the formation of more robust covalently crosslinked networks by free radical polymerization of acrylic monomers, exploiting the mechanical properties of these networks more efficiently. This technique yields strong and elastic networks but with an undefined network structure. In this work, we use acrylate-capped telechelic polymers derived from the step-growth polymerization of PEG diacrylate and dithiothreitol to crosslink methacrylated TEMPO-oxidized cellulose nanofibrils (MATO CNF). This combination resulted in flexible and strong hydrogels, as observed through rheological studies, compression and tensile loading. The structure and mechanical properties of these hydrogel networks were found to depend on the dimensions of the CNFs and polymer crosslinkers. The structure of the networks and the role of individual components were evaluated with SAXS (Small-Angle X-ray Scattering) and photo-rheology. A thorough understanding of hybrid CNF/polymer networks and how to best exploit the capacity of these networks enable further advancement of cellulose-based materials for applications in packaging, soft robotics, and biomedical engineering.The authors acknowledge the financial support from the Knut and Alice Wallenberg Foundation through the Wallenberg Wood Science Center</p
Egestabase – An online evidence platform to discover and explore options to recover plant nutrients from human excreta and domestic wastewater for reuse in agriculture
No full textRestoring nutrient circularity across scales is important for ecosystem integrity as well as nutrient and food security. As such, research and development of technologies to recover plant nutrients from various organic residues has intensified. Yet, this emerging field is diverse and difficult to navigate, especially for newcomers. As an increasing number of actors search for circular solutions to nutrient management, there is a need to simplify access to the latest knowledge. Since the majority of nutrients entering urban areas end up in human excreta, we have chosen to focus on human excreta and domestic wastewater. Through systematic mapping with stakeholder engagement, we compiled and consolidated available evidence from research and practice. In this paper, we present ‘Egestabase’ – a carefully curated open-access online evidence platform that presents this evidence base in a systematic and accessible manner. We hope that this online evidence platform helps a variety of actors to navigate evidence on circular nutrient solutions for human excreta and domestic wastewater with ease and keep track of new findings. We are grateful to all stakeholders who provided valuable feedback and inputs. Egestabase was developed as part of the project \"End-of-wastewater\", which has received funding from the Kamprad Family Foundation under grant agreement 20200021 . Early stakeholder engagement took place as part of the project \"Going circular\", which has received funding from the Swedish Research Council for Environment , Agricultural Sciences and Spatial Planning (Formas) under grant agreement 2019-02476 .</p