35 research outputs found

    14C in aerosols:what F14C value to use for contemporary carbon

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    Toward a Standardised Thermal-Optical Protocol for Measuring Atmospheric Organic and Elemental Carbon: The EUSAAR Protocol

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    Thermal-optical analysis is a conventional method for determining the carbonaceous aerosol fraction and for classifying it into organic carbon, OC, and elemental carbon, EC. Unfortunately, the different thermal evolution protocols in use can result in a wide elemental carbon-to-total carbon variation by up to a factor of five. In Europe, there is currently no standard procedure for determining the carbonaceous aerosol fraction which implies that data from different laboratories at various sites are of unknown accuracy and cannot be considered comparable. In the framework of the EU-project EUSAAR (European Supersites for Atmospheric Aerosol Research), a comprehensive study has been carried out to identify the causes of differences in the EC measured using different thermal evolution protocols; thereby the major positive and negative biases affecting thermal-optical analysis have been isolated and minimised to define an optimised protocol suitable for European aerosols. Our approach to improve the accuracy of the discrimination between OC and EC was essentially based on four goals. Firstly, charring corrections rely on faulty assumptions ¿e.g. pyrolytic carbon is considered to evolve completely before native EC throughout the analysis¿, thus we have reduced pyrolysis to a minimum by favoring volatilisation of OC. Secondly, we have minimised the potential negative bias in EC determination due to early evolution of light absorbing carbon species at higher temperatures in the He-mode, including both native EC and combinations of native EC and pyrolytic carbon potentially with different specific cross section values. Thirdly, we have minimised the potential positive bias in EC determination resulting from the incomplete evolution of OC during the He-mode which then evolves during the He/O2-mode, potentially after the split point. Finally, we have minimised the uncertainty due to the position of the OC/EC split point on the FID response profile by introducing multiple desorption steps in the He/O2-mode. Based on different types of carbonaceous PM encountered across Europe, we have defined an optimised thermal evolution protocol, the EUSAAR_2 protocol, as follows: step 1 in He, 200°C for 120s; step 2 in He 300°C for 150s; step 3 in He 450°C for 180s; step 4 in He 650°C for 180s. For steps 1-4 in He/O2, the conditions are 500°C for 120 s, 550°C for 120s, 700°C for 70s, and 850°C for 80s, respectively.JRC.DDG.H.2-Climate chang

    Exposure and Emission Measurements During Production, Purification, and Functionalization of Arc-Discharge-Produced Multi-walled Carbon Nanotubes.

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    Background: The production and use of carbon nanotubes (CNTs) is rapidly growing. With increased production, there is potential that the number of occupational exposed workers will rapidly increase. Toxicological studies on rats have shown effects in the lungs, e.g. inflammation, granuloma formation, and fibrosis after repeated inhalation exposure to some forms of multi-walled CNTs (MWCNTs). Still, when it comes to health effects, it is unknown which dose metric is most relevant. Limited exposure data for CNTs exist today and no legally enforced occupational exposure limits are yet established. The aim of this work was to quantify the occupational exposures and emissions during arc discharge production, purification, and functionalization of MWCNTs. The CNT material handled typically had a mean length <5 ÎŒm. Since most of the collected airborne CNTs did not fulfil the World Health Organization fibre dimensions (79% of the counted CNT-containing particles) and since no microscopy-based method for counting of CNTs exists, we decided to count all particle that contained CNTs. To investigate correlations between the used exposure metrics, Pearson correlation coefficient was used

    Measurement of Elemental and Organic Carbon in Europe

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    The new Air Quality Directive 2008/50/EC is asking in Annex IX that elemental (EC) and organic (OC) carbon as well as soluble ions should be measured at selected background sites in each Member State. Several methods (thermal, optical or photo-acoustic methods) to determine elemental and organic carbon exist which do not always deliver comparable results. European experts in EC/OC measurements met at the JRC in Ispra on 10th and 11th February 2009 to discuss during a workshop the best suitable European method. The main tasks of this workshop were to discuss the advantages and disadvantages of different methods for the determination of OC and EC, to get information from the Member States on existing methods or even standards being applied, to initiate discussions on a preferred basic method to be standardised by CEN within the scope of Directive 2008/50/EC. The conclusions of this workshop will directly feed into CEN and the corresponding Working Group to clearly define their task for European wide standardisation and hence harmonisation.JRC.H.4-Transport and air qualit

    Drivkrafter till frivillighet : En jÀmförelse av drivkrafterna till svenska frivilliga under finska vinterkriget, och svenska frivilliga under Bosnienkonflikten

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    NĂ€r Sovjetunionen anföll Finland 1939 bad Finland Sverige om hjĂ€lp. Sveriges regering beslutade att vara icke krigförande d.v.s. inte hjĂ€lpa Finland med reguljĂ€ra styrkor för att hĂ„lla Sverige utanför kriget sĂ„ lĂ€nge det gick. En svensk frivilligrörelse skapades och totalt vĂ€rvades drygt 8000 man. Idag Ă„ker över tusen svenska frivilliga om Ă„ret pĂ„ internationella uppdrag runtom i vĂ€rlden, för att som det har varit hittills, bevara fred. I framtiden kommer vi förmodligen fĂ„ se svenskar som genomför fredsframtvingande uppdrag. Vad Ă€r det som fĂ„r svenskar att frivilligt Ă„ka till krigszoner och riskera sitt liv? Är det nĂ„gon skillnad pĂ„ de drivkrafter som fick folk att anmĂ€la sig frivilliga till finska vinterkriget och de som Ă„ker pĂ„ moderna internationella insatser, eller Ă€r drivkraften till internationellt deltagande tidlösa?   Syftet med denna uppsats Ă€r att jĂ€mföra drivkrafter till frivillighet. Att undersöka vilka likheter och skillnader i drivkrafter som finns till en modern insats (Bosnienbataljonerna Ă€r bra exempel pĂ„ nya tidens FN-missioner) och till en historisk insats. Följande tre frĂ„gstĂ€llningar svarar uppsatsen pĂ„:   1. Vilka drivkrafter lĂ„g bakom de svenska frivilligas deltagande under finska vinterkriget? 2. Vilka drivkrafter ligger bakom deltagandet till BA01-BA04? 3. Vilka likheter och skillnader ligger bakom drivkraften till deltagandet i finska vinterkriget och moderna internationella insatser?   Författaren anvĂ€nder sig av deduktiv metod och ett hermeneutiskt vetenskapligt förhĂ„llningssĂ€tt. Dispositionen i denna uppsats utgörs i huvudsak av tre delar, en del som beskriver Svenska Finlandsfrivilligas enkĂ€tundersökning och de svar pĂ„ drivkrafter som den ger. DĂ€refter sker en fördjupad kvalitativ textanalys om finska vinterkriget och drivkrafterna för de svenska frivilliga. Slutligen genomförs en beskrivande del av Bosnienbataljonerna, med fokus pĂ„ de bakomliggande drivkrafterna. JĂ€mförelsen av data sker sedan med hjĂ€lp av ett antal motivationsparametrar.   De slutsatser som framkom var att den största likheten syns i motivationsparametern ”Behov av uppskattning”. De största skillnaderna har varit i motivationsparametrarna: ”Behov av trygghet”, ”Behov av prestation”, ”Behov av meningsfullhet” och ”Behov av utveckling”. Andelen som angav motivationsparameter ”Behov av trygghet” var större i fallet Finland och resterande tre var större i fallet Bosnien

    Source apportionment of carbonaceous aerosol - Measurement and model evaluation

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    Aerosol particles are found in the whole troposphere. Research regarding these particles has gained increased attention because of the effect the particles have on both health and climate. In the atmosphere, aerosol particles scatter incoming solar radiation and this has a cooling effect on the Earth’s climate. But there are particles, especially those containing soot, which can absorb sun light and therefore having a heating effect on the Earth’s climate. Soot and other carbonaceous particles are problematic in atmospheric models. They originate from several sources and their emission factors are uncertain. Model parameterisations and emission inventories for carbonaceous aerosol have recently been improved in the EMEP model. To evaluate the changes to the atmospheric model and its input, the model results must be compared with measurements. Measurements of carbonaceous aerosol and their sources are therefore important to improve the models and to be able to accurately determine how atmospheric aerosol concentrations would be influenced by future changes of the emissions. In this thesis, radiocarbon, OC/EC and organic tracers was used as input in to a receptor model to determine the sources to carbonaceous aerosols. The result was subsequently used to evaluate simulations from the EMEP model. Radiocarbon is, as a radioactive carbon isotope, depleted in fossil fuels and therefore a good tracer for modern sources of carbonaceous particles such as biomass burning and the biota. The carbon mass required for radiocarbon analysis has within the frame of this work been lowered to 11 ”g. This is an important step to be able to measure radiocarbon in aerosol samples that contain low amounts of carbon. Using tracers and OC/EC, I have found that carbonaceous particles in Southern Sweden originate from mainly biogenic sources in the summer and mainly combustion of fossil fuels and biomass burning in the winter. Model comparison showed that the model could reproduce carbonaceous aerosol concentrations fairly well although not reproduce the sources’ individual contributions. However, a newly developed emission inventory for residential wood combustion improved the model’s results compared to the measurements. A similar method that was used to determine the sources of atmospheric particles was used to determine to what extent diesel particles originated from the fuel and the lubrication oil. The soot (EC) was mainly formed from the fuel whereas the oil contributed to hydrocarbons in the exhaust. A method comparison showed that the method usually used by the engine manufactures will underestimate the influence of the lubrication oil

    Bra? Jag mÄr fantastiskt! : en kvalitativ studie om hÀlsa

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    Sammanfattning Detta Ă€r en studie baserad pĂ„ en nationell longitudinell studie pĂ„ svenska skolelever (Skola, Idrott och HĂ€lsa projektet, SIH). Syfte och frĂ„gestĂ€llningar: Syftet med studien var att undersöka varför unga vuxna skattar sin hĂ€lsa som bra. Det primĂ€ra syftet var att ta reda pĂ„ vilka faktorer som informanterna upplever som meningsfulla för sin subjektivt upplevda hĂ€lsa. Ett sekundĂ€rt syfte var att undersöka hur informanternas upplevda hĂ€lsa har förĂ€ndrats sedan 2010. Hur definierar respondenterna begreppet hĂ€lsa? Hur ser respondenterna pĂ„      sin hĂ€lsa i relation till sin/sitt vardag, boende, arbete/studier, fritid,      trĂ€ning, familj/vĂ€nner, dĂ„tid/framtid? I vilken utstrĂ€ckning upplever respondenterna att de kan pĂ„verka sin      livssituation? Metod: Studien Ă€r av kvalitativ karaktĂ€r. Tio semistrukturerade intervjuer har genomförts med urvalsgruppen, vilka har sitt ursprung i SIH-projektet och i undersökningen frĂ„n 2010 skattat sin hĂ€lsa som mycket bra. Intervjuerna har utgĂ„tt frĂ„n sju frĂ„geomrĂ„den: Vardag, arbete/studier, fritid, trĂ€ning, familj/vĂ€nner, dĂ„tid/framtid samt patogena frĂ„gestĂ€llningar. Resultatet har analyserats utifrĂ„n Antonovskys KASAM-begrepp. Resultat: Studiens resultat visar att kontroll över vardagen, fysisk aktivitet samt till viss del ocksĂ„ religiöst engagemang möjligen kan ha ett samband med informanternas goda hĂ€lsostatus. Resultatet visar ocksĂ„ att informanternas hĂ€lsostatus har försĂ€mrats nĂ„got sedan 2010, bĂ„de fysiskt och psykiskt. Slutsats: VĂ„ra informanter har en hög KASAM i förhĂ„llande till sin vardag, vilket möjligtvis resulterar i deras goda hĂ€lsostatus. Vikten av fysisk aktivitet och social interaktion Ă€r tvĂ„ faktorer som belyses genom denna studie. Vi har dĂ€remot sett svĂ„righeten att visa pĂ„ vad som de facto pĂ„verkar vad. VĂ„r tolkning Ă€r att möjligheten för en faktor att pĂ„verka en individ, positivt eller negativt, stĂ„r i förhĂ„llande till deras subjektiva uppfattning och vĂ€rderingar.Abstract This is a study based on a national longitudinal study on Swedish school students (the School, sport and health project, SIH). Aim: The purpose of this study was to examine why young adults rate their health as good. The primary purpose was to determine the factors that respondents perceive as meaningful for their subjectively perceived health. A secondary purpose was to investigate how the informants self rated health status have changed since 2010. How do the respondents define the concept of health? How do the respondents reflect about their health in relation to their everyday life, living, work/studies, leisure, training, family/friends, past life/future life? In which extent do the respondents feel that they can influence their own lives? Method: The study is of a qualitative character. Ten semi-structured interviews were conducted with a sample group, which originated in the SIH project. The interviews have been based on seven main topics: Everyday life, work /studies, leisure, training, family/friends, past life / future life and pathogenic problems. The results have been analyzed on the basis of Antonovsky's SOC-term Results: Our results demonstrate that the control over daily life, physical activity, and to some extent also religious participation could possibly be related to the informants' good health status. The results also show that informants’ health status has deteriorated slightly since 2010, both physically and mentally. Conclusion: Our informants have a high SOC in relation to their daily lives, which might result in their good health status. The importance of physical activity and social interaction are two factors highlighted by this study. However, we have seen the difficulty of ascertaining what actually affects what. Our interpretation is that the ability of a factor to affect an individual, positively or negatively, is proportional to their subjective perception and values

    BÄltrÀning : forskningslÀge och vardag

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    Syfte och frĂ„gestĂ€llningar Syftet med studien var att undersöka hur trĂ€nare och sjukgymnaster/naprapater i Stockholmsregionen arbetar med specifik bĂ„ltrĂ€ning. Ett sekundĂ€rt syfte var att se pĂ„ historiska förĂ€ndringar av trĂ€ningsmetoder. Hur arbetar trĂ€nare med specifik bĂ„ltrĂ€ning? Hur arbetar sjukgymnaster/naprapater med specifik bĂ„ltrĂ€ning? Hur motiverar de sitt val av trĂ€ningsmetod? Vad sĂ€ger forskningen om vilka fördelar/nackdelar olika metoder av bĂ„ltrĂ€ning har?   Metod Vi har i vĂ„r studie anvĂ€nt oss av intervjuer. En kvalitativ metod för att fĂ„ en djupgĂ„ende inblick i hur personliga trĂ€nare och sjukgymnaster/naprapater arbetar med bĂ„ltrĂ€ning. Vi har intervjuat sex personer, tre frĂ„n vardera yrkeskategorin. Intervjumallen utformades utifrĂ„n vĂ„rt syfte och frĂ„gestĂ€llningar.   Resultat Alla intervjupersoner arbetar mot klientens mĂ„l efter dennes individuella styrkor och svagheter. ArbetssĂ€ttet Ă€r genomgĂ„ende, att man efter analys av klienten, arbetar enligt progressionsprincipen, individualiseringsprincipen och variationsprincipen. Det finns inget generellt motstĂ„nd mot en speciell övning, men flera av vĂ„ra intervjupersoner har nĂ„gon övning de undviker, pĂ„ grund av olika anledningar.   Slutsats Vi har noterat att studierna kring bĂ„ltrĂ€ning Ă€r vĂ€ldigt tvetydiga och det Ă€r dĂ€rför svĂ„rt att skapa sig nĂ„gon entydig uppfattning om vad som Ă€r ”rĂ€tt” eller ”fel”. DĂ€remot förordar flera studier att man skall trĂ€na bĂ„lens alla delar för bĂ€sta effekt och att man ska anpassa sitt övningsval efter syftet med trĂ€ningen. Vi har fĂ„tt en bra bild av hur personliga trĂ€nare och naprapater/sjukgymnaster arbetar nĂ€r det gĂ€ller bĂ„ltrĂ€ning. Kontentan av det hela Ă€r att man skall ha ett mĂ„l och syfte med varje övning

    Bra? Jag mÄr fantastiskt! : en kvalitativ studie om hÀlsa

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    Sammanfattning Detta Ă€r en studie baserad pĂ„ en nationell longitudinell studie pĂ„ svenska skolelever (Skola, Idrott och HĂ€lsa projektet, SIH). Syfte och frĂ„gestĂ€llningar: Syftet med studien var att undersöka varför unga vuxna skattar sin hĂ€lsa som bra. Det primĂ€ra syftet var att ta reda pĂ„ vilka faktorer som informanterna upplever som meningsfulla för sin subjektivt upplevda hĂ€lsa. Ett sekundĂ€rt syfte var att undersöka hur informanternas upplevda hĂ€lsa har förĂ€ndrats sedan 2010. Hur definierar respondenterna begreppet hĂ€lsa? Hur ser respondenterna pĂ„      sin hĂ€lsa i relation till sin/sitt vardag, boende, arbete/studier, fritid,      trĂ€ning, familj/vĂ€nner, dĂ„tid/framtid? I vilken utstrĂ€ckning upplever respondenterna att de kan pĂ„verka sin      livssituation? Metod: Studien Ă€r av kvalitativ karaktĂ€r. Tio semistrukturerade intervjuer har genomförts med urvalsgruppen, vilka har sitt ursprung i SIH-projektet och i undersökningen frĂ„n 2010 skattat sin hĂ€lsa som mycket bra. Intervjuerna har utgĂ„tt frĂ„n sju frĂ„geomrĂ„den: Vardag, arbete/studier, fritid, trĂ€ning, familj/vĂ€nner, dĂ„tid/framtid samt patogena frĂ„gestĂ€llningar. Resultatet har analyserats utifrĂ„n Antonovskys KASAM-begrepp. Resultat: Studiens resultat visar att kontroll över vardagen, fysisk aktivitet samt till viss del ocksĂ„ religiöst engagemang möjligen kan ha ett samband med informanternas goda hĂ€lsostatus. Resultatet visar ocksĂ„ att informanternas hĂ€lsostatus har försĂ€mrats nĂ„got sedan 2010, bĂ„de fysiskt och psykiskt. Slutsats: VĂ„ra informanter har en hög KASAM i förhĂ„llande till sin vardag, vilket möjligtvis resulterar i deras goda hĂ€lsostatus. Vikten av fysisk aktivitet och social interaktion Ă€r tvĂ„ faktorer som belyses genom denna studie. Vi har dĂ€remot sett svĂ„righeten att visa pĂ„ vad som de facto pĂ„verkar vad. VĂ„r tolkning Ă€r att möjligheten för en faktor att pĂ„verka en individ, positivt eller negativt, stĂ„r i förhĂ„llande till deras subjektiva uppfattning och vĂ€rderingar.Abstract This is a study based on a national longitudinal study on Swedish school students (the School, sport and health project, SIH). Aim: The purpose of this study was to examine why young adults rate their health as good. The primary purpose was to determine the factors that respondents perceive as meaningful for their subjectively perceived health. A secondary purpose was to investigate how the informants self rated health status have changed since 2010. How do the respondents define the concept of health? How do the respondents reflect about their health in relation to their everyday life, living, work/studies, leisure, training, family/friends, past life/future life? In which extent do the respondents feel that they can influence their own lives? Method: The study is of a qualitative character. Ten semi-structured interviews were conducted with a sample group, which originated in the SIH project. The interviews have been based on seven main topics: Everyday life, work /studies, leisure, training, family/friends, past life / future life and pathogenic problems. The results have been analyzed on the basis of Antonovsky's SOC-term Results: Our results demonstrate that the control over daily life, physical activity, and to some extent also religious participation could possibly be related to the informants' good health status. The results also show that informants’ health status has deteriorated slightly since 2010, both physically and mentally. Conclusion: Our informants have a high SOC in relation to their daily lives, which might result in their good health status. The importance of physical activity and social interaction are two factors highlighted by this study. However, we have seen the difficulty of ascertaining what actually affects what. Our interpretation is that the ability of a factor to affect an individual, positively or negatively, is proportional to their subjective perception and values
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