| 1. |
- Gustafsson, Berit, 1966-, et al.
(författare)
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Longitudinal pathways of engagement, social interaction skills,hyperactivity and conduct problems in preschool children
- 2021
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Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 62:2, s. 170-184
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Tidskriftsartikel (refereegranskat)abstract
- Preschool children’s engagement/social interaction skills can be seen as aspects of positive functioning, and also act as protective aspects of functioning.On the other hand, hyperactivity/conduct problems are risk aspects that negatively affect children’s everyday functioning. Few studies have investigatedsuch orchestrated effects on mental health in young children over time. The aims of the study are rst, to identify homogeneous groups of children havingsimilar pathways in mental health between three time points. Second, to examine how children move between time points in relation to risk and protectivefactors. Alongitudinal study over 3 years, including 197 Swedish preschool children was used. Questionnaire data collected from preschool teachers.Statistical analysis using person-oriented methods with repeated cluster analyses. Children high in engagement/social skills and low in conduct problemscontinue to function well. Children with low engagement/social skills exhibiting both hyperactivity and conduct problems continue to have problems.Children with mixed patterns of protective factors and risk factors showed mixed outcomes. The stability of children’s pathways was quite high if theyexhibited many positive protective factors but also if they exhibited many risk factors. Children exhibiting a mixed pattern of protective and risk factorsmoved between clusters in a less predictable way. That stability in mental health was related to the simultaneous occurrence of either many protectivefactors or many risk factors supports the notion of orchestrated effects. The results indicate that early interventions need to have a dual focus, includingboth interventions aimed at enhancing child engagement and interventions focused on decreasing behavior problem.
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| 2. |
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| 3. |
- Uddh Söderberg, Terese, 1976-, et al.
(författare)
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Challenges in geochemical modelling of metal(loid) solubility and binding mechanisms along a soil profile at a multi-contaminated site
- 2024
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Ingår i: Applied Geochemistry. - : Elsevier. - 0883-2927 .- 1872-9134. ; 170
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Tidskriftsartikel (refereegranskat)abstract
- Recognising the need for robust models in predicting groundwater contamination risks from metal(loid)s in contaminated topsoil, this study focuses on the geochemical behaviour of As, Cd, Cu, Pb, Sb and Zn in one of Sweden’s most heavily contaminated areas. Samples were collected from the waste zone and underlying subsoil down to 5 meters and batch experiments were carried out to assess pH-dependent solubility. The results indicate that Cd, Cu, Pb and Zn are efficiently immobilized in the waste zone, while As(V) and Sb(V) are more easily leached. With the exception of Pb and Cu at high pH, the mobilized metals appear to be predominantly in a truly dissolved state, as confirmed by ultrafiltration at 10 kDa.Speciation modelling using Visual MINTEQ did not suggest a significant role of precipitates such as Zn or Pb arsenates and phosphates, although their involvement could not be ruled out. To better understand sorption/desorption patterns, a multi-surface geochemical model was established, drawing on the Stockholm Humic and CD-MUSIC models for organic matter and Fe/Al (hydr)oxide sorption. However, when default parameters were used, the model consistently overestimated the solubility of Cd, Cu, Pb and Zn in both the waste zone and the uncontaminated subsoil. In contrast, As(V) solubility was generally underestimated, also when the reactive surface area of the Fe- and Al (hydr)oxides was decreased in the model. The model's performance was better for Sb(V), though not without imperfections. When the parameters for organic matter were adjusted such that 100% of the solid-phase organic matter was active with respect to ion binding, but only 25% of the dissolved organic matter, the model description improved considerably for Pb and Cu in the upper soil layers. The model revealed distinct differences in the adsorption behaviour of the metal cations, with Pb being sorbed mostly to Fe/Al (hydroxides), whereas a considerable part of Cu was sorbed to organic matter, particularly in the waste zone.Possibly, the dissolution of easily weatherable metal-containing mineral phases may have contributed to the poor model performance for Cd, Zn and for Cu in the deeper soil layers, although other factors, such as a contribution of hydrous SiO2 or Mn oxides to metal binding, could not be ruled out. Metal sorption to carbonate phases may also have been a contributing factor in the waste zone. Lastly, the reactivity of Fe- and Al (hydr)oxides may have been overestimated by oxalate extraction when default parameters for high-surface-area ferrihydrite were applied. These findings provide valuable insights for environmental management and underscore the need for a more detailed characterization of metal(loid) sorption in contaminated soils, as well as the development of improved modelling strategies to enhance solubility predictions.
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| 5. |
- Alves, C. A., et al.
(författare)
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Physical and chemical properties of non-exhaust particles generated from wear between pavements and tyres
- 2020
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Ingår i: Atmospheric Environment. - : Elsevier Ltd. - 1352-2310 .- 1873-2844. ; 224
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Tidskriftsartikel (refereegranskat)abstract
- A road simulator was used to generate wear particles from the interaction between two tyre brands and a composite pavement. Particle size distributions were monitored using a scanning mobility particle sizer and an aerosol particle sizer. Continuous measurements of particle mass concentrations were also made. Collection of inhalable particles (PM10) was conducted using a high-volume sampler equipped with quartz filters, which were then analysed for organic and elemental carbon, organic constituents and elemental composition. Tyre fragments chopped into tiny chips were also subjected to detailed organic and elemental speciation. The number concentration was dominated by particles <0.5 μm, whereas most of the mass was found in particles >0.5 μm. The emission factor from wear between pavements and tyres was of the order of 2 mg km−1 veh−1. Organic carbon represented about 10% of the PM10 mass, encompassing multiple aliphatic compounds (n-alkanes, alkenes, hopanes, and steranes), PAHs, thiazols, n-alkanols, polyols, some fragrant compounds, sugars, triterpenoids, sterols, phenolic constituents, phthalate plasticisers and several types of acids, among others. The relationship between airborne particulate organic constituents and organic matter in tyre debris is discussed. The detection of compounds that have been extensively used as biomass burning tracers (e.g. retene, dehydroabietic acid and levoglucosan) in both the shredded tiny tyre chips and the wear particles from the interaction between tyres and pavement puts into question their uniqueness as markers of wood combustion. Trace and major elements accounted for about 5% of the mass of the tyre fragments but represented 15–18% of the PM10 from wear, denoting the contribution of mineral elements from the pavement. Sulphur and zinc were abundant constituents in all samples.
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| 6. |
- Ammenberg, Jonas, 1973-, et al.
(författare)
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Perspectives on biomethane as a transport fuel within acircular economy, energy, and environmental system
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The literature indicates that the life cycle costs of biomethane fueled light vehicles may be 15 to 20% highe rthan for similar petrol and diesel fueled vehicles, while liquid biomethane fueled heavy duty trucks may have similar life cycle costs to diesel. However, such an analysis can be two dimensional and limited in the message it conveys. On one hand the acceptance of diesel fueled trucks and buses will be limited due to the climate emergency and air pollution and after 2030 diesel may not be the competition for biomethane anymore. On the otherhand, biomethane production is part of a larger circular economy, energy, and environmental system. It is verydifficult to divorce the energy vector, biomethane, from the system through which it is produced. In essence biomethane can be considered as one of the products or services of a broad biogas system.An advantage of biogas is that it can be produced from most wet organic wastes or by-products, includingfor food waste, animal by-products, (such as manure), agricultural residues, sewage sludge, industrial biowaste (such as from slaughterhouses and food and beverage processing industries). Biogas production is an element in the environmental management of such wastes; biogas plants can also deliver digestate, which contains most ofthe nutrients in the feedstock and can be an excellent biofertilizer. In addition, it is possible to utilize the carbon dioxide removed in upgrading biogas to biomethane as a product with added value. The resource of biomethane is very significant in considering the vast amounts of organic wastes landfilled around the world each year, that instead could be used to produce biogas, biofertilizers and food grade CO2 while improving the environment through reduced fugitive methane emissions and improved water quality. Furthermore, the application of biogas systems in bio-industrial contexts (such as paper mills, food production facilities, or other types of biorefineries) has huge potential to decarbonize industry while significantly increasing the resource of biomethane. Due to the multifunctionality of biomethane solutions, broad assessment methods are needed to grasp thewide spectrum of relevant factors when comparing different technologies:• Biomethane has a competitive performance compared with fossil fuels and other biofuels on a whole lifecycle analysis and is particularly suited to long distance heavy vehicles.• Biomethane from manure, residues, waste & catch crops is estimated to have low GHG emissions ascompared to other renewable fuels.• Biomethane may contribute to reduced air pollution in comparison with diesel, petrol, and other biofuels.• Biomethane can contribute to a substantial reduction in acidification compared with fossil fuels.• Biomethane may contribute to significantly reduced noise levels in comparison with diesel heavy goodsvehicles.• Well-designed and applied biogas systems may be essential to transform conventional farming to moresustainable farming and to organic farming.• Common types of biogas solutions provide essential sociotechnical systems services as components ofsystems for waste and (waste) water management.• Biogas solutions may importantly contribute to improved energy supply/security and flexibility.Natural gas systems should be a facilitator of the introduction of biomethane for transport, but the sustainability problems associated with natural gas negatively impact the view of biomethane. This is where arguments amongst the renewable sector actors can hinder progress. Biomethane and (power to methane) can utilize the existing gas grid and accelerate progress to decarbonization of the overall energy sector beyond just electricity and also to decarbonize chemical (such as ammonia and methanol) and steel production. This should be advantageous especially when realizing that more energy is procured from the natural gas grid than the electricity gridin the EU and the US; however, suggestions that biomethane is only greenwashing the natural gas industry, and in doing so extending the lifetime of natural gas, greatly impedes this progress.This report provides exemplars of very good biomethane based transport solutions, with a high technologicalreadiness level for all elements of the chain from production to vehicles. Transport biomethane sits well in the broad circular economy, energy, and environmental system providing services across a range of sectors including reduction in fugitive methane emissions from slurries, treatment of residues, environmental protection, provision of biofertiliser, provision of food grade CO2 and a fuel readily available for long distance heavy haulage. What we do not have is time to postpone the sustainable implementation of such circular economy biomethane systems as the climate emergency will not wait for absolutely perfect zero emission solutions; should they exist.
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| 7. |
- Andersson-Sköld, Yvonne, 1957, et al.
(författare)
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Microplastics from tyre and road wear: a literature review
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This literature review concerns microplastics from tyre and road wear caused by road traffic. As there is limited knowledge about microplastics in general, and microplastics from road traffic in particular, the Swedish Government commissioned the Swedish National Road and Transport Research Institute (VTI) to, during 2018-2020, develop and disseminate knowledge about microplastics from road traffic. The chapters in this report summarises existing knowledge about microplastics from road traffic with respect to the following aspects: sources, spread and presence; effects on and risk to the environment and human health; characteristics and chemical composition; tyre and road wear; sampling methods; analysis and sample preparation; and measures. The report also includes a chapter with overall conclusions, and a chapter about further research, development and investigation needs. The purpose of this report is to provide a basis for reducing the generation and spread of microplastics from road traffic. One aim of the report is to collate and disseminate knowledge about microplastics generated by tyre and road wear, and to review the current level of knowledge. A second aim is to identify knowledge gaps and research requirements in relation to microplastics from road traffic. This literature review is based on a review of scientific articles and reports, as well as technical literature and some information from experts and industry.
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| 8. |
- Andersson-Sköld, Yvonne, 1957-, et al.
(författare)
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Mikroplast från däck- och vägslitage : en kunskapssammanställning
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna kunskapssammanställning handlar om mikroplast från vägtrafikens däck- och vägslitage. Eftersom kunskapen om mikroplaster från vägtrafiken är begränsad samtidigt som däckslitage bedöms vara den största källan till utsläpp av mikroplast i Sverige, gav regeringen inom ramen för sitt arbete med plast och mikroplast Statens väg- och transportforskningsinstitut (VTI) i uppdrag att under 2018– 2020 ta fram och sprida kunskap om mikroplast från vägtrafiken. Varje kapitel i denna rapport sammanfattar befintlig kunskap om mikroplast från vägtrafiken avseende en eller flera aspekter. Dessa aspekter är: källor, spridning och förekomst; miljö- och hälsoeffekter samt risker; egenskaper och kemisk sammansättning; däck- och vägslitage; provtagningsmetoder; analys- och provberedningsmetoder samt åtgärder. Dessutom finns ett kapitel med sammanfattande slutsatser och allra sist ett kapitel om forsknings-, utvecklings- och utredningsbehov.Syftet med rapporten är att den ska utgöra ett underlag för att minska emissioner och spridning av mikroplast från vägtrafiken. Ett mål med rapporten är att sammanställa och sprida kunskap om mikroplast från däck- och vägslitage och att redogöra för nuvarande kunskapsläge. Ytterligare ett mål är att identifiera kunskaps- och forskningsbehov avseende mikroplast från vägtrafiken.Underlaget till denna kunskapssammanställning utgörs av vetenskapliga artiklar och rapporter samt facklitteratur och information från branschen och från experter.
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| 9. |
- Ardi, Shanai, et al.
(författare)
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A Case Study of Introducing Security Risk Assessment in Requirements Engineering in a Large Organization
- 2023
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Ingår i: SN Computer Science. - : Springer. - 2661-8907. ; 4:5
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Tidskriftsartikel (refereegranskat)abstract
- Software products are increasingly used in critical infrastructures, and verifying the security of these products has become a necessary part of every software development project. Effective and practical methods and processes are needed by software vendors and infrastructure operators to meet the existing extensive demand for security. This article describes a lightweight security risk assessment method that flags security issues as early as possible in the software project, namely during requirements analysis. The method requires minimal training effort, adds low overhead, and makes it possible to show immediate results to affected stakeholders. We present a longitudinal case study of how a large enterprise developing complex telecom products adopted this method all the way from pilot studies to full-scale regular use. Lessons learned from the case study provide knowledge about the impact that upskilling and training of requirements engineers have on reducing the risk of malfunctions or security vulnerabilities in situations where it is not possible to have security experts go through all requirements. The case study highlights the challenges of process changes in large organizations as well as the pros and cons of having centralized, distributed, or semi-distributed workforce for security assurance in requirements engineering.
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| 10. |
- Blohm, My, et al.
(författare)
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Learning by doing : an observational study of the learning curve for ultrasonic fundus-first dissection in elective cholecystectomy
- 2022
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Ingår i: Surgical Endoscopy. - : Springer. - 0930-2794 .- 1432-2218. ; 36, s. 4602-4613
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Surgical safety and patient-related outcomes are important considerations when introducing new surgical techniques. Studies about the learning curves for different surgical procedures are sparse. The aim of this observational study was to evaluate the learning curve for ultrasonic fundus-first (FF) dissection in elective laparoscopic cholecystectomy (LC).METHODS: The study was conducted at eight hospitals in Sweden between 2017 and 2019. The primary endpoint was dissection time, with secondary endpoints being intra- and postoperative complication rates and the surgeon's self-assessed performance level. Participating surgeons (n = 16) were residents or specialists who performed LC individually but who had no previous experience in ultrasonic FF dissection. Each surgeon performed fifteen procedures. Video recordings from five of the procedures were analysed by two external surgeons. Patient characteristics and data on complications were retrieved from the Swedish Registry of Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography (GallRiks).RESULTS: Dissection time decreased as experience increased (p = 0.001). Surgeons with limited experience showed more rapid progress. The overall complication rate was 14 (5.8%), including 3 (1.3%) potentially technique-related complications. Video assessment scores showed no correlation with the number of procedures performed. The self-assessed performance level was rated lower when the operation was more complicated (p < 0.001).CONCLUSIONS: Our results show that dissection time decreased with increasing experience. Most surgeons identified both favourable and unfavourable aspects of the ultrasonic FF technique. The ultrasonic device is considered well suited for gallbladder surgery, but most participating surgeons preferred to dissect the gallbladder the traditional way, beginning in the triangle of Calot. Nevertheless, LC with ultrasonic FF dissection can be considered easy to learn with a low complication rate during the initial learning curve, for both residents and specialists.
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