| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 4. |
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| 5. |
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| 6. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 7. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Forskningsöversikt (refereegranskat)
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| 19. |
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| 20. |
- Krasilnikov, A., et al.
(författare)
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Evidence of 9 Be + p nuclear reactions during 2ω CH and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas
- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:2
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Tidskriftsartikel (refereegranskat)abstract
- The intensity of 9Be + p nuclear fusion reactions was experimentally studied during second harmonic (2ω CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasmas. In relatively low-density plasmas with a high ICRH power, a population of fast H+ ions was created and measured by neutral particle analyzers. Primary and secondary nuclear reaction products, due to 9Be + p interaction, were observed with fast ion loss detectors, γ-ray spectrometers and neutron flux monitors and spectrometers. The possibility of using 9Be(p, d)2α and 9Be(p, α)6Li nuclear reactions to create a population of fast alpha particles and study their behaviour in non-active stage of ITER operation is discussed in the paper.
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| 29. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:9
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Tidskriftsartikel (refereegranskat)
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| 30. |
- Abbott, Benjamin W., et al.
(författare)
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Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
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| 31. |
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| 32. |
- Cantwell-Jones, Aoife, et al.
(författare)
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Mapping trait versus species turnover reveals spatiotemporal variation in functional redundancy and network robustness in a plant-pollinator community
- 2023
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Ingår i: Functional Ecology. - : John Wiley & Sons. - 0269-8463 .- 1365-2435. ; 37:3, s. 748-762
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Tidskriftsartikel (refereegranskat)abstract
- Functional overlap among species (redundancy) is considered important in shaping competitive and mutualistic interactions that determine how communities respond to environmental change. Most studies view functional redundancy as static, yet traits within species—which ultimately shape functional redundancy—can vary over seasonal or spatial gradients. We therefore have limited understanding of how trait turnover within and between species could lead to changes in functional redundancy or how loss of traits could differentially impact mutualistic interactions depending on where and when the interactions occur in space and time. Using an Arctic bumblebee community as a case study, and 1277 individual measures from 14 species over three annual seasons, we quantified how inter- and intraspecific body-size turnover compared to species turnover with elevation and over the season. Coupling every individual and their trait with a plant visitation, we investigated how grouping individuals by a morphological trait or by species identity altered our assessment of network structure and how this differed in space and time. Finally, we tested how the sensitivity of the network in space and time differed when simulating extinction of nodes representing either morphological trait similarity or traditional species groups. This allowed us to explore the degree to which trait-based groups increase or decrease interaction redundancy relative to species-based nodes. We found that (i) groups of taxonomically and morphologically similar bees turn over in space and time independently from each other, with trait turnover being larger over the season; (ii) networks composed of nodes representing species versus morphologically similar bees were structured differently; and (iii) simulated loss of bee trait groups caused faster coextinction of bumblebee species and flowering plants than when bee taxonomic groups were lost. Crucially, the magnitude of these effects varied in space and time, highlighting the importance of considering spatiotemporal context when studying the relative importance of taxonomic and trait contributions to interaction network architecture. Our finding that functional redundancy varies spatiotemporally demonstrates how considering the traits of individuals within networks is needed to understand the impacts of environmental variation and extinction on ecosystem functioning and resilience. Read the free Plain Language Summary for this article on the Journal blog.
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| 33. |
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| 34. |
- Forouzanfar, Mohammad H, et al.
(författare)
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Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013 : a systematic analysis for the Global Burden of Disease Study 2013.
- 2015
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 386:10010, s. 2287-2323
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.METHODS: Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol.FINDINGS: All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8-58·5) of deaths and 41·6% (40·1-43·0) of DALYs. Risks quantified account for 87·9% (86·5-89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa.INTERPRETATION: Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.FUNDING: Bill & Melinda Gates Foundation.
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| 35. |
- Gabriel, Sofia I., et al.
(författare)
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Colonization, mouse-style
- 2010
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Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 8, s. 131-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Several recent papers, including one in BMC Evolutionary Biology, examine the colonization history of house mice. As well as background for the analysis of mouse adaptation, such studies offer a perspective on the history of movements of the humans that accidentally transported the mice.
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| 36. |
- Hogfors, Hedvig, et al.
(författare)
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Conservation values from a seascape perspective : User manual for MOSAIC, version 1
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Havs- och vattenmyndigheten har till uppgift att skapa förutsättningar för en hållbar förvaltning och planering av våra havsområden. I denna uppgift ingår att ta fram metoder och underlag som främjar en väl fungerande grön infrastruktur och bevarande av olika naturvärden. I syfte att förbättra kunskapen om naturvärden i marina områden har Havs- och vattenmyndigheten utvecklat Mosaic. Mosaic (dnr 1592-20) är ett verktyg för att identifiera värdefulla marina områden med särskild betydelse för biologisk mångfald och ekosystemtjänster i livskraftiga och ekologiskt representativa nätverk. Verktyget ger underlag för rumslig förvaltning, som till exempel arbete med fysisk planering (havs-/kustzonsplanering), områdesskydd, restaurering och fiskförvaltning. Grunden för Mosaic utgörs av ekosystemkomponenter, som vetenskapliga och regionala experter på ekosystemen i Sveriges havsområden tagit fram utifrån riktlinjer i Mosaic. Denna rapport är en användarmanual för hur man steg för steg tillämpar Mosaic.Det är Havs- och vattenmyndighetens förhoppning att manualen kan underlätta tillämpningen av Mosaic (Havs- och vattenmyndigheten rapport 2020:13). Målgrupper för Mosaic är framför allt de som arbetar med förvaltning och fysisk planering av kustzonen och havsmiljön på nationella myndigheter, länsstyrelser och kommuner. Men även verksamhetsutövare och konsultföretag som utför arbeten relaterat till detta.
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| 37. |
- Hogfors, Hedvig, et al.
(författare)
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MOSAIC – A tool for ecosystem based spatial management of marine conservation values : Version 1
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- För att främja ekosystembaserad marin förvaltning bör olika förvaltningsområden integreras. En enhetlig kartläggning av den marina gröna infrastrukturen kan verka för att rätt förvaltning och åtgärd hamnar på rätt plats. Mosaic är ett verktyg för att identifiera värdefulla marina områden med särskild betydelse för biologisk mångfald och ekosystemtjänster i livskraftiga och ekologiskt representativa nätverk. Avsikten är att ge en enhetlig struktur som ger hög gemensam nytta för flera olika former av rumslig förvaltning som till exempel områdesskydd, fysisk planering (havs/kustzonsplanering), restaurering och åtgärdsarbete samt annan typ av förvaltning där areella frågor ska behandlas (såsom fiskförvaltning och arbete med havsmiljödirektivet och art- och habitatdirektivet). Syftet med Mosaic är att främja ett ekosystembaserat, adaptivt och funktionellt angreppsätt vid rumslig naturvård. Avsikten är att ge en struktur som så förutsättningslöst som möjligt inkluderar en mängd olika biotiska ekosystemkomponenter vid bedömning och identifiering av värdefulla områden. Med sin högre mångfald kan verktyget ge stöd vid bedömningar och prioriteringar inom förvaltningsprocesser som bygger på ett fåtal och grövre ekosystemkomponenter framtagna för större regioner. Verktyget ger en struktur för att inkludera ny kunskap, följa ekosystemets förändring över tid och ta hänsyn till ekosystemets rumsliga variation och komplexitet – från platsspecifika detaljer till ett landskapsperspektiv.Syftet med den här rapporten är att ge en ingående beskrivning av Mosaic, teorin bakom, de avvägningar och diskussioner som har hållits samt vad verktyget kan användas till. För att få en praktisk manual vid användning av verktygets genomförandedel behöver denna rapport inte läsas utan vi hänvisar till Havs- och vattenmyndighetens rapport 2020:14 Marina naturvärden i ett landskapsperspektiv – användarmanual för Mosaic, version 1.Mosaic är uppdelat i två delar (figur 1) varav en del är förberedande och samordnas av Havs- och vattenmyndigheten, medan genomförandedel samordnas av respektive länsstyrelse eller annan utövare. I den förberedande delen ska bästa tillgängliga kunskap samlas in och syntetiseras av experter för att göra generella, ej platsspecifika, bedömningar (dessa ska därefter användas för landskapsanalyser och platsspecifika bedömningar i Mosaics genomförandedel). Med andra ord fokuserar bedömningarna i den förberedande delen inte på rumslig variation utan istället på allmänna mönster. Det gör det enklare att vid de återkommande revideringarna följa generella förändringar över tid och inkludera ny kunskap. I Mosaics genomförandedel ska värdekärnor (platser med höga naturvärden) och värdetrakter identifieras. Värdetrakter är områden med höga naturvärden (ansamlingar av värdekärnor) i livskraftiga och ekologiskt representativa nätverk. Fokus för bedömningarna och analyserna i genomförandedelen är främst att identifiera ekosystemens rumsliga variation genom platsspecifika detaljkunskaper och fördjupade landskapsanalyser om var naturvärden troligen ansamlas, var viktiga spridningsvägar går, var livskraftiga platser troligen finns och vilka av dessa platser utgör ett ekologiskt representativt nätverk. Med livskraftiga platser avses platser där ekosystemkomponenter är mindre utsatta för negativ påverkan. Det är svårt att över tid följa förändring av platsspecifika detaljer på en mängd lokaler eftersom det ofta är resurskrävande med fältinventeringar. Mer generella förändringar fångas dock upp genom att genomförandedelen inkluderar bedömningar som regelbundet uppdateras i den förberedande delen. För att kunna bedöma vilka områden som ska prioriteras för förvaltningsåtgärder (till exempel genom skydd, fysisk planering eller restaurering) behöver ett område jämföras med övriga områden, från regional till lokal skala. Platsspecifika detaljkunskaper behövs i kombination med övergripande kunskap om landskapet.Mosaic fokuserar på biotiska ekosystemkomponenter (populationer, arter, organismgrupper och livsmiljöer) eftersom det är de biotiska komponenterna som för med sig naturvärden och är känsliga för mänskliga aktiviteter. Vidare är det de biotiska ekosystemkomponenterna vi vill försäkra är representerade i områden som prioriteras för rumslig förvaltning. Vidare utgår verktyget från internationellt vedertagna kriterier satta av FN:s konvention om biologisk mångfald (Convention on Biological Diversity; CBD; 2008). Kriterierna har införlivats i verktygets olika delar och steg för att nå uppsatta mål och skapa en praktisk arbetsordning. Det här är version 1 av verktyget Mosaic. Alla pusselbitar (ramar) har ännu inte fått detaljerade riktlinjer men genom att publicera dem i sin nuvarande form kommer verktyget att utvecklas utifrån de erfarenheter som görs när det används praktiskt och när andra parallella processer (inom till exempel områdesskydd och havsplanering) är genomförda.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Jones, Frida C., et al.
(författare)
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The presence of zinc in Swedish waste fuels
- 2013
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 33:12, s. 2675-2679
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Tidskriftsartikel (refereegranskat)abstract
- Zinc (Zn) is a chemical element that has gained more attention lately owing to its possibility to form corrosive deposits in large boilers, such as Waste-to-Energy plants. Zn enters the boilers in many different forms and particularly in waste, the amount of Zn is hard to determine due to both the heterogeneity of waste in general but also due to the fact that little is yet published specifically about the Zn levels in waste. This study aimed to determine the Zn in Swedish waste fuels by taking regular samples from seven different and geographically separate waste combustion plants over a 12-month period. The analysis shows that there is a relation between the municipal solid waste (MSW) content and the Zn-content; high MSW-content gives lower Zn-content. This means that waste combustion plants with a higher share of industrial and commercial waste and/or building and demolition waste would have a higher share of Zn in the fuel. The study also shows that in Sweden, the geographic location of the plant does not have any effect on the Zn-content. Furthermore, it is concluded that different seasons appear not to affect the Zn concentrations significantly. In some plants there was a clear correlation between the Zn-content and the content of other trace metals.
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| 42. |
- Jones, Frida, et al.
(författare)
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Determination of fossil carbon content in Swedish waste fuel by four different methods
- 2013
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Ingår i: Waste Management & Research. - 0734-242X .- 1096-3669. ; 31:10, s. 1052-1061
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to determine the content of fossil carbon in waste combusted in Sweden by using four different methods at seven geographically spread combustion plants. In total, the measurement campaign included 42 solid samples, 21 flue gas samples, 3 sorting analyses and 2 investigations using the balance method. The fossil carbon content in the solid samples and in the flue gas samples was determined using 14C-analysis. From the analyses it was concluded that about a third of the carbon in mixed Swedish waste (municipal solid waste and industrial waste collected at Swedish industry sites) is fossil. The two other methods (the balance method and calculations from sorting analyses), based on assumptions and calculations, gave similar results in the plants in which they were used. Furthermore, the results indicate that the difference between samples containing as much as 80% industrial waste and samples consisting of solely municipal solid waste was not as large as expected. Besides investigating the fossil content of the waste, the project was also established to investigate the usability of various methods. However, it is difficult to directly compare the different methods used in this project because besides the estimation of emitted fossil carbon the methods provide other information, which is valuable to the plant owner. Therefore, the choice of method can also be controlled by factors other than direct determination of the fossil fuel emissions when considering implementation in the combustion plants.
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| 43. |
- Jones, Frida, et al.
(författare)
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Down-time corrosion in boilers
- 2016
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Ingår i: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 141, s. 276-284
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Tidskriftsartikel (refereegranskat)abstract
- Down-time corrosion can occur on boiler surfaces, e.g. furnace walls, superheaters, or economizers that are covered with hygroscopic deposits, when the temperature drops under 100 °C. This scenario takes place when a boiler is shut-down for cleaning, maintenance, or other reasons, such as unplanned shut-downs. Initially, the dry deposits will absorb moisture from the surrounding air, potentially creating a corrosive environment. After this, corrosive acids can form in the deposits. In this study modified online-corrosion probes were used in combination with deposits taken from 6 different boilers at various locations (for example, from the furnace, the superheater, and the economizer), where the fuels have been waste, demolition wood or biomass. The deposits were ground and dried in an oven at 160 °C for several hours before exposed to a moist environment (RH 65%) during online measuring of the corrosion rate and the pitting activity. Four types of alloys were tested: low-alloy ST45.8-steel, 9% Cr ferritic P91-steel, austenitic stainless steel 304L, and Ni-based super Alloy 625. The results for ST45.8 show that in biomass boilers a corrosion rate from negligible values up to 0.7 mm/year can be reached within a week, while waste-fired boilers can have rates as high as 1.8 mm/year. Furthermore, for some samples from waste-fired boilers show a high pitting activity already after 24 h. The tests with the P91-steel show values up to 0.16 mm/year, for samples from different locations in the boiler. For 304L and Alloy 625 the down-time corrosion was negligible even after a two-week exposure. The ability to follow the down-time corrosion online has provided data that show that even though thought to be negligible, the risk of down-time corrosion is of significance, especially if the fuel is waste. Also, even if the initial corrosion rate is low, it increases during the first 24 h due to the exposure to moist environment, motivating immediate cleaning of the boilers after shut-down, especially on surfaces of lower steel quality.
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| 44. |
- Jones, Frida, et al.
(författare)
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Effects of Reduced Bed Temperature in Laboratory- and Full-Scale Fluidized-Bed Boilers : Particle, Deposit, and Ash Chemistry
- 2013
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 27:8, s. 4999-5007
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on how the temperature of the bed in a waste-fired fluidized-bed boiler affects the chemical composition of ash and deposits. The aim was to reduce the concentration of corrosive elements in the convection pass, which can lead to both less frequent soot blowing intervals and extended superheater lifetimes. Complementary laboratory-scale tests were carried out in a single-pellet reactor to study online alkali and Zn emissions during temperature changes, using an ICP-MS instrument. The full-scale study was based on full-scale experiments at a plant consisting of two 20 MWth fluidized-bed boilers firing a mixture of municipal solid waste and industrial waste. The boilers are normally operated at bed temperatures of about 870 C. This normal operation was compared in this work to a test case in which the bed temperature was reduced below 720 C by altering the air staging and flue gas recycling. The experimental work included collecting samples of fuel, ash, and particles under the two different sets of operating conditions. Furthermore, deposits on temperature-controlled probes were sampled upstream of the superheaters. By reducing the bed temperature, the sand consumption of the plant could be reduced by roughly 25%. The measurements showed that the amount of submicrometer particles decreased and the fouling rate on deposit probes was reduced by about 20%. The measured concentration of HCl in the flue gas increased as the bed temperature was reduced. This might be a consequence of the reduced formation of alkali chlorides. In addition, results from the laboratory-scale tests indicated a trend of reduced alkali emissions from the fluidized bed with reduced temperature, and thermodynamic equilibrium calculations confirmed the trends.
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| 45. |
- Jones, Frida, et al.
(författare)
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Förekomstformer av bly, koppar och zink i askor från avfallsförbränningsanläggningar
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under 2014 reviderades den europeiska lagstiftningen avseende klassning av farligt avfall vilket också påverkar klassificeringen av askor från avfallsförbränning, framförallt bottenaskor. Den klassningsmetodik som främst används för askor i Sverige idag har behov av stöd för att motivera valen av referenssubstanser. Detta föranledde föreliggande projekt med syftet att göra en genomgång av förekomstformer för bly, koppar och zink i flygaskor och bottenaskor, som rapporterats i vetenskaplig litteratur. Till detta kommer också en diskussion om lakning baserad på ett antal rapporter valda i samråd med referensgruppen till projektet.Litteraturstudien har undersökt ca 150 publikationer totalt. Genomgången visar att det för bottenaskor finns väldigt lite publicerat kring förekomstformer av bly, koppar och zink. För flygaskor finns det däremot fler publikationer. De artiklar och rapporter som har identifierats visar stor spridning av olika förekomstformer. Dock är det sällan många forskare/forskargrupper som hittat samma mineral/kemiska föreningar. Om detta beror på skillnad mellan vilka föreningar man letat efter (vilket är en begränsning i analysmetoderna) eller om det beror på skillnader i askans sammansättning är svårt att svara på. Det finns heller ingen enighet om hur de resultat som finns rapporteras; detta gäller både för val/användande av analysmetod och på vilken bas koncentrationer rapporteras. Nästan varje ny, för projektet relevant referens, rapporterar om en eller flera mineralformer som inte fanns i tidigare referenser. Detta har gjort att antalet förekomstformer rapporterade i denna litteraturstudie är relativt stort men att det oftast är en eller ett par olika askor som de rapporteras för. Även detaljnivån på bakgrundsdata som från vilket bränsle eller panntyp som askorna härstammar skiljer sig mycket åt mellan publikationerna. Det gör det svårt att bedöma relevansen av resultaten i de olika publikationerna. De kvantifierade förekomster som finns är nästan helt uteslutande framtagna på olika typer av flygaskor.Vid en jämförelse mellan resultaten av projektet och de referenssubstanser som används i den tidigare nämnda beräkningsmodellen rekommenderar projektet:• Ett tillägg av metalliskt bly som referenssubstans för blyföreningar• att koppar(II)oxid byts mot koppar(II)hydroxid för flygaska (kvarstår som koppar(II)oxid för bottenaska)• att zink(II)oxid byts mot zink(II)klorid för flygaskor (kvarstår som zink (II)oxid för bottenaskor)Däremot anser projektet inte att det finns tillräckligt underlag för att rekommendera en generell fördelning mellan referenssubstanserna.Projektet visar alltså att det finns relativt lite material i litteraturen kring förekomstformerna i aska. För att öka kunskapen inom området och komma framåt avseende klassificeringsfrågan finns det olika vägar att gå. Generellt är det ett väldigt komplext område och rekommendationen är att gå vidare med en kombination av lakningsstudier, beräkningsmetoder och analyser av förekomstformer med specialiserade tekniker, som till exempel kan göras vid Max IV i Lund.
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| 46. |
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| 47. |
- Jones, Frida, et al.
(författare)
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Occurrence and sources of zinc in fuels
- 2014
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 117:A, s. 763-775
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have shown that the presence of high amounts of Zn, in addition to other elements, in fuels can be a cause of operational difficulties during combustion due to corrosion and slagging and can also cause environmental and health problems due to emissions. In nature, Zn is an essential micronutrient for humans, animals and plants, but in excessive amounts it becomes toxic. This paper presents a review on the content of Zn in different fuels used in energy conversion systems. Altogether, over 20 different fuels divided among waste, biomass and fossil fuels were studied. The highest amounts of Zn are present in waste-derived fuels, particularly in Tire-Derived Fuel (TDF). In tires, Zn is used as a vulcanizing agent and can reach concentration values of 9600-16,800 mg kg-1DS. Waste Electrical and Electronic Equipment (WEEE) is the second Zn-richest fuel; while on average Zn content is around 4000 mg kg-1DS., values of over 19,000 mg kg-1DS. were also reported. High amounts of Zn, 3000-4000 mg kg-1DS., are also found in municipal solid waste (MSW), sludge with over 2000 mg kg-1DS. on average (some exceptions up to 49,000 mg kg-1DS.), and other waste-derived fuels (over 1000 mg kg-1DS.). Zn can also be found in fossil fuels. In coal, the level of Zn is quite low, on average 100 mg kg-1DS., while higher amounts of Zn were reported for oil shale, with values between 20 and 2680 mg kg-1DS. The content of Zn in biomass is basically determined by its natural occurrence, typically 10-100 mg kg-1DS.
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| 48. |
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| 49. |
- Jones, Frida, et al.
(författare)
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Thermal Stability of Zinc Compounds
- 2013
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 27:10, s. 5663-5669
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Tidskriftsartikel (refereegranskat)abstract
- Zn and Cl have been found in deposits in municipal solid waste (MSW) boilers and industrial boilers. This leads to the general belief that ZnCl 2 may play a role in corrosion of heat-transfer tubes, owing to its low melting temperature and high corrosivity. In this study, the thermal stability of the compounds ZnCl2, ZnSO4, and ZnO as well as mixtures of ZnCl2 and NaCl/KCl was investigated by means of thermogravimetric analysis/differential scanning calorimetry (TGA/DSC). The reactions of the Zn compounds with SO2/SO3 and HCl were also investigated. The results obtained show that ZnCl2 melts at 320 C. Above 400 C, ZnCl2 vaporizes and is partly oxidized to ZnO. ZnSO4 is stable up to 680 C, at which it decomposes and, subsequently, forms ZnO above 900 C. ZnO is stable at a much higher temperatures but can be chlorinated to ZnCl2 in the presence of HCl at temperatures around 300 C. In the presence of a large amount of NaCl/KCl, which is typically the case in actual boilers, ZnCl2 reacts with NaCl/KCl to form 2NaCl·ZnCl2 and 2KCl·ZnCl2, respectively. These compounds melt at temperatures lower than NaCl and KCl but higher than ZnCl2. The findings show the significance of understanding the thermal stability of various zinc compounds, how they interact with one another, and whether they react with alkali chlorides and other compounds in the deposits to assess the role of Zn in deposit formation and corrosion in boilers burning Zn-containing fuels.
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| 50. |
- Kassebaum, Nicholas J., et al.
(författare)
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Global, regional, and national disability-adjusted life-years (DALYs) for 315 diseases and injuries and healthy life expectancy (HALE), 1990-2015 : a systematic analysis for the Global Burden of Disease Study 2015
- 2016
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 388:10053, s. 1603-1658
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Tidskriftsartikel (refereegranskat)abstract
- Background Healthy life expectancy (HALE) and disability-adjusted life-years (DALYs) provide summary measures of health across geographies and time that can inform assessments of epidemiological patterns and health system performance, help to prioritise investments in research and development, and monitor progress toward the Sustainable Development Goals (SDGs). We aimed to provide updated HALE and DALYs for geographies worldwide and evaluate how disease burden changes with development. Methods We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2015. We calculated DALYs by summing years of life lost (YLLs) and years of life lived with disability (YLDs) for each geography, age group, sex, and year. We estimated HALE using the Sullivan method, which draws from age-specific death rates and YLDs per capita. We then assessed how observed levels of DALYs and HALE differed from expected trends calculated with the Socio-demographic Index (SDI), a composite indicator constructed from measures of income per capita, average years of schooling, and total fertility rate. Findings Total global DALYs remained largely unchanged from 1990 to 2015, with decreases in communicable, neonatal, maternal, and nutritional (Group 1) disease DALYs off set by increased DALYs due to non-communicable diseases (NCDs). Much of this epidemiological transition was caused by changes in population growth and ageing, but it was accelerated by widespread improvements in SDI that also correlated strongly with the increasing importance of NCDs. Both total DALYs and age-standardised DALY rates due to most Group 1 causes significantly decreased by 2015, and although total burden climbed for the majority of NCDs, age-standardised DALY rates due to NCDs declined. Nonetheless, age-standardised DALY rates due to several high-burden NCDs (including osteoarthritis, drug use disorders, depression, diabetes, congenital birth defects, and skin, oral, and sense organ diseases) either increased or remained unchanged, leading to increases in their relative ranking in many geographies. From 2005 to 2015, HALE at birth increased by an average of 2.9 years (95% uncertainty interval 2.9-3.0) for men and 3.5 years (3.4-3.7) for women, while HALE at age 65 years improved by 0.85 years (0.78-0.92) and 1.2 years (1.1-1.3), respectively. Rising SDI was associated with consistently higher HALE and a somewhat smaller proportion of life spent with functional health loss; however, rising SDI was related to increases in total disability. Many countries and territories in central America and eastern sub-Saharan Africa had increasingly lower rates of disease burden than expected given their SDI. At the same time, a subset of geographies recorded a growing gap between observed and expected levels of DALYs, a trend driven mainly by rising burden due to war, interpersonal violence, and various NCDs. Interpretation Health is improving globally, but this means more populations are spending more time with functional health loss, an absolute expansion of morbidity. The proportion of life spent in ill health decreases somewhat with increasing SDI, a relative compression of morbidity, which supports continued efforts to elevate personal income, improve education, and limit fertility. Our analysis of DALYs and HALE and their relationship to SDI represents a robust framework on which to benchmark geography-specific health performance and SDG progress. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform financial and research investments, prevention efforts, health policies, and health system improvement initiatives for all countries along the development continuum.
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