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  • 2751.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Allhammar, Göran
    Chlorinated aromatics from metallurgical industries: Process factors influencing production and emissions1989In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 19, no 1-6, p. 711-716Article in journal (Refereed)
    Abstract [en]

    The emission and production of chlorinated aromatics from metallurgical industries, e g scrap-metal re-melting, show substantial variations due to a number of process factors. The data evaluated indicates clearly that the production of chlorinated aromatics is combustion controlled.

  • 2752.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergbäck, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    A review of probabilistic risk assessment of contaminated land2005In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 5, no 4, p. 213-224Article in journal (Refereed)
    Abstract [en]

    Background, Aims and Scope. The management and decisions concerning restoration of contaminated land often require in-depth risk analyses. An environmental risk assessment is generally described as proceeding in four separate steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization. The risk assessment should acknowledge and quantify the uncertainty in risk predictions. This can be achieved by applying probabilistic methods which, although they have been available for many years, are still not generally used. Risk assessment of contaminated land is an area where probabilistic methods have proved particularly useful. Many reports have appeared in the literature, mostly by North American researchers. The aim of this review is to summarize the experience gained so far, provide a number of useful examples, and suggest what may be done to promote probabilistic methods in Europe and the rest of the world. Methods. The available literature has been explored through searches in the major scientific and technical databases, WWW resources, textbooks and direct contacts with active researchers. A calculation example was created using standard simulation software. Results and Discussion. Uncertainty and variability are part of every risk assessment. Much work on risks from contaminated soil has focussed on exposure, and choice and structure of the exposure model is then a basic uncertainty factor. Other factors, e.g. parameter uncertainty, are easier to characterize. Variability can be separated into inter-individual, spatial and temporal components. Both uncertainty and variability in the exposure variables can be investigated using Monte Carlo simulation methods. These simulations enable not only the estimation of the probability for a given risk or exposure, but also add information on the sensitivity of the various input variables. This will assist the assessor in further refining the risk analysis. The large number of applications published encompasses soil contamination by lead, arsenic, chromium, uranium, polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), hexachlorobenzene, pentachlorophenol and chlorinated solvents. Probabilistic risk assessments have been used in widely different settings, such as the metallurgical industry (mining and smelting operations), manufacturing, gas plants, wood impregnation, infrastructure, and waste landfills. Site-specific remediation goals can be specified using probabilistic methods, and a guideline document has been issued within the US Superfund programme. The usability of probabilistic risk assessment is illustrated by a calculation example. The current Swedish generic guideline value for benzo[a]pyrene in contaminated soil, with ingestion of vegetables as the major route of exposure, is compared with a probabilistic estimate. The toxicological reference value corresponds well with the upper 95th percentile of the estimated variability in intake, but does not account for uncertainty in the partition coefficients. Conclusions and Outlook. The probabilistic approach to risk assessment has proved its value in characterizing variability and uncertainty, and thereby contributing to a more informed and transparent decision-making process. The management of contaminated land is a major environmental application for probabilistic risk assessments. A substantial number of studies have been published and the method is now well established in the scientific community. This development has progressed further in the United States than elsewhere, but similar applications are now being reported from Europe and Asia. Probabilistic risk assessment is used to derive soil guideline values in the United Kingdom, and other countries may be anticipated to follow. However, efficient use of probabilistic methods for risk assessment of contaminated land requires certain components. There is a requirement for quality assurance and transparency that can be met by guidelines specifying data requirements and which items to report on. Both federal and state governments in the United States have issued such guidelines, and we see a similar need from a European perspective. A second component, necessary for a successful implementation of probabilistic methods, is education. We have ourselves developed undergraduate curricula, but we also see a need for continuous education of risk assessors and decision makers. The third component required is case studies, showing how probabilistic risk assessment can be implemented successfully in the cleanup of contaminated land. Most published studies originate from the United States, so here too there is a need for the rest of the world to catch up. In addition to the three components mentioned, there is an obvious need to develop and improve methods and practice of risk communication.

  • 2753.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergbäck, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Probabilistisk riskbedömning. Sannolikhetsbaserad uppskattning av miljö- och hälsorisker i förorenade markområden – en litteraturöversikt2005Report (Other academic)
  • 2754.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergbäck, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Filipsson, Monika
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Catalytic effects by metal oxides on the formation and degradation of chlorinated aromatic compounds in fly ash.2008In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 71, no 6, p. 1135-43Article in journal (Refereed)
    Abstract [en]

    Polychlorinated benzenes, dibenzo-p-dioxins (PCDD), and dibenzofurans (PCDF) may be formed below the combustion temperature in fly ash from municipal solid waste incinerators (MSWI). Copper catalyzes this formation, possibly by the Deacon reaction. Many other elements are also Deacon catalysts or promoters, and here we report results from a statistically designed experiment with 15 metal oxides added to fly ash and heated at 300 degrees C for 2h in an air atmosphere. A resolution IV fractional factorial design with four replicates was completed in 36 runs with the oxides of magnesium, yttrium, titanium, vanadium, niobium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper, zinc, and tin. All samples were analyzed for chlorinated benzenes and the results were evaluated by analysis of variance. The addition of copper significantly increased the amounts of the chlorinated benzenes, while cobalt, chromium and vanadium decreased the net formation. The oxides of zinc and iron seemed to have a slightly positive and negative effect respectively. The findings in this study seem to corroborate our previously reported results regarding the different catalytic effects of copper and chromium, and lack of a significant effect by nickel. Besides chromium, it also identifies cobalt and vanadium as potent catalysts for oxidative degradation of the chlorinated aromatic compounds found in MSWI fly ash.

  • 2755.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergbäck, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Öberg, Erik
    Different catalytic effects by copper and chromium on the formation and degradation of chlorinated aromatic compounds in fly ash.2007In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 41, no 10, p. 3741-3746Article in journal (Refereed)
    Abstract [en]

    Fly ash from municipal solid waste incineration may catalytically enhance the formation and degradation of chlorinated aromatic compounds. The activities of three Deacon catalysts in this process were investigated in a statistically designed experiment. Chlorides of copper, chromium, and nickel were added to fly ash samples and the resulting samples heated at 300 degrees C for 2 h in an air atmosphere. The addition of copper increases the formation of all chlorinated aromatic compounds except the low chlorinated congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans. The addition of chromium decreased the formation of most chlorinated aromatic compounds except the highest chlorinated species, where it was without effect. The addition of nickel did not show any significant effect. The outcome of the experiment can be interpreted as two competing processes: the chlorination of aromatic rings and the oxidation of carbon-carbon and carbon-oxygen bonds. The delicate balance between chlorination and oxidation could probably be further exploited to minimize both the emissions and the net production of chlorinated aromatic compounds from combustion.

  • 2756.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Combustion test data from a Swedish hazardous waste incinerator1986In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 15, no 9-12, p. 2045-2048Article in journal (Refereed)
    Abstract [en]

    Here we present results from our tests with PCB-incineration at the SAKAB hazardous waste incinerator in Norrtorp, Sweden. Combustion tests were made with PCB both as a fluid (Arochlor 1242) and as a contaminant of solid waste (Arochlor 1016 in capacitors). A general conclusion was that the incineration of considerable amounts of PCB did not effect the production of PCDD and PCDF in this combustion plant.

  • 2757.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Emission and chlorination pattern of PCDD/PCDF predicted from indicator parameters1987In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 16, no 6, p. 1221-1230Article in journal (Refereed)
    Abstract [en]

    The emission and chlorination pattern of polychlorinated dioxins and dibenzofurans from waste combustion shows a close covariation with that of chlorinated benzenes and phenols. This covariation can be utilized to predict the emission levels of specific isomers as well as the pattern of congeners.

  • 2758.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Halogenated aromatics from waste incineration – indicator parameters1987In: American Flame Research Committee, 1987Conference paper (Other academic)
  • 2759.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Hexachlorobenzene as an indicator of dioxin production from combustion1985In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 14, no 8, p. 1081-1086Article in journal (Refereed)
    Abstract [en]

    The production of polychlorinated dioxins and dibenzofurans shows a strong correlation with the production of hexachlorobenzene. Hexachlorobenzene can be used as an indicator for the production of chlorinated aromatics.

  • 2760.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Indicator Parameters for PCDD/PCDF1989In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 19, no 1-6, p. 337-344Article in journal (Refereed)
    Abstract [en]

    Relations between different chlorinated aromatics have been evaluated in 66 samples from various industrial activities. For municipal waste combustion partial least squares modelling with latent variables (PLS) can explain 86 % of the variance in PCDD/PCDF from the isomerspecific analytical data for chlorinated benzenes and phenols.

  • 2761.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Indicator parameters for PCDD/PCDF: plant specific models1992In: Organohalogen Compounds, ISSN 1026-4892, Vol. 8, p. 197-200Article in journal (Refereed)
    Abstract [en]

    Previously presented results have shown that the emissions of PCDD/PCDF can be modelled and predicted from less costly and more precise isomerspecific analyses of different chlorinated benzenes and phenols. The new results we report here comes from a study aimed to further utilize these possibilities and develop specific models for each plant to accomplish maximum precision and accuracy in the calibration process. Plant specific models have been developed for two municipal waste combustion (MWC) facilities and one metallurgic industry.

  • 2762.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergström, Jan
    Organiska mikroföroreningar från stålverk1988Report (Other academic)
    Abstract [sv]

    Miljökonsulterna har på uppdrag av Jernkontoret värderat mätningarna av organiska mikroföroreningar från nio svenska stålverk utförda under tiden 1985 till och med 1987.

    Mätningarna utgör enbart kortvariga stickprov. Så finns t ex utsläppet till luft av polycykliska aromatiska kolväten, PAH, endast dokumenterade med 13 analyserade prov. För TCDD-ekvivalenter är antalet redovisade prov 18 stycken. Intervallet mellan de högsta och lägsta uppmätta utsläppen är för PAH 8 till 920 mg/ton stål och för TCDD-ekivalenter <0.3 till 9 µg/ton. Det är därför inte möjligt att ur mätresultaten beräkna ett realistiskt värde för normalutsläpp från stålverken idag.

    Det föreligger en tydlig samvariation av mängden PAH och klorerade aromater i utsläppet från de olika stålverken. Det är därför rimligt att utgå från att bildning och destruktion av föroreningarna är i huvudsak förbränningsstyrda förlopp. Mätresultaten styrker därmed att utsläppen kan minimeras genom relativt enkla insatser för att höja oxidationsnivån genom efterförbränning av processgaserna.

  • 2763.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Darnerud, Per-Ola
    Hajslova, Jana
    Miljögifter i fisk 2001/2002: Vänern och Vättern.2003Report (Other academic)
    Abstract [sv]

    Vätternvårdsförbundet och Vänerns vattenvårdsförbund har genomfört en undersökning av miljögifter i fisk som omfattar 38 kemiska ämnen och ämnesgrupper samt "dioxiner" (PCDD/PCDF) och PCB (polyklorerade bifenyler). I undersökningen ingår dels ämnen från den normala livsmedelskontrollen, dels de ämnen som anges i EUs vattendirektiv. Analyserna av "EU-ämnena" har genomförts med stöd från Naturvårdsverket som är delfinansiär av projektet. De fiskarter som har undersökts är lax (Vänern), öring, röding (Vättern) och lake. Undersökningen ger därmed en relativt heltäckande bild av föroreningssituationen vad gäller fisk i Sveriges två största insjöar.

    Analyserna av samlingsprov har utförts av Livsmedelsverket, Umeå universitet och ALcontrol AB. De flesta av de analyserade föroreningarna saknades helt i fiskproven. När det gäller allmänna miljöföroreningar så är det främst mjukgörare, ytaktiva ämnen och några enkla lösningsmedel som har detekterats. Däremot saknas spår av de flesta avvecklade och nu godkända icke-klorerade bekämpningsmedel, dock med tennorganiska föreningar som ett viktigt undantag.. Samma iakttagelse är även giltig för icke-klorerade polycykliska aromatiska kolväten (PAH). Av redovisning framgår att det främst är långlivade klororganiska föreningar som kan påvisas hos de flesta fiskarterna.

    En tydlig minskning av klororganiska föreningarna skedde under 1970- och början av 1980-talet. Sedan dess har nivåerna legat relativt stabila. Kvicksilver, PCDD/PCDF och dioxinlika PCB är de ämnesgrupper som ligger högst i relation till de nivåer som har angetts som tolerabla från ett folkhälsoperspektiv. Det finns därför skäl att koncentrera undersökningsinsatserna till dessa grupper av miljöföroreningar. Klart är dock att medelhalten av PCDD/PCDF i fet fisk från Vänern och Vättern ligger under EUs nuvarande gränsvärde på 4 pg/g färskvikt.

    Långlivade klorerade miljögifter fortsätter alltså att vara ett bekymmer, men när de gäller bekämpningsmedel så är det inte längre ett nationellt problem. Den statistiska utvärderingen av föroreningsmönstret tyder på att både klorerade bekämpningsmedelsrester och PCB kan härröra från långväga transport eller från någon typ av "depåer" (ifrån tidigare utsläpp och användning). Däremot samvarierar PCDD, PCDF och hexaklorbensen inbördes, men endast i begränsad utsträckning med de övriga miljöföroreningarna. Då alla tre substansgrupperna kan bildas i högtemperaturprocesser så är det inte en orimlig hypotes att dessa föroreningar främst har sitt ursprung i närområdet.

  • 2764.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Deming, Stanley. N.
    Find optimum operating conditions fast2000In: Chemical engineering progress, ISSN 0360-7275, E-ISSN 1945-0710, Vol. 96, no 4, p. 53-59Article in journal (Refereed)
    Abstract [en]

    In today's world of intense financial competition, chemical processes must be optimized quickly if they are to become successful. These successful processes must continue to be operated optimally if they are to retain their competitive edge. In this article, we discuss statistically-based optimization strategies that can be used to achieve these two goals of achieving and maintaining optimized processes.

  • 2765.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Filipsson, Monika
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bergbäck, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Exposure factors: How to characterize the data?2007In: Annual Meeting of the Society for Risk Analysis, San Antonio, Texas, 9-12 december 2007, 2007Conference paper (Other academic)
  • 2766.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Liu, Tao
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Global and local PLS regression models to predict vapor pressure2008In: QSAR & combinatorial science (Print), ISSN 1611-020X, E-ISSN 1611-0218, Vol. 27, no 3, p. 273-279Article in journal (Refereed)
    Abstract [en]

    The vapor pressure is a key property in determining the distribution and fate of environmentally relevant compounds, but experimental determinations are only available for alimited number of the chemicals in current commercial use. Despite experimental efforts there is a need for estimation methods. The liquid or subcooled liquid vapor pressures at 298.15 K were collected from the literature for a diverse set of 1340 organic compounds. Theoretical molecular descriptors were derived after optimization to low-energy conformations and used to investigate the performance of global and local Quantitative Structure – Property Relationships (QSPR). A global PLSR model with ten latent variables was found to be optimal. The predictive performance of this model, within the domain of applicability, was estimated at n=420, Q2Ext0.980, and RMSEP=0.410 (log Pa). This model can be used in conjunction with other estimation models to assess the potential for a long range atmospheric transport.

     

  • 2767.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Liu, Tao
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Linear free energy relationships and latent variable methods: Similarity in modelling environmentally relevant properties2009In: SETAC Europe 19th Annual Meeting i Göteborg, 31 maj-4 juni, 2009Conference paper (Other academic)
  • 2768.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Neuer-Etscheidt, Katja
    Nordsieck, Hermann
    Zimmermann, Ralf
    Dioxin surrogates: a comparison of approaches2002In: Organohalogen Compounds, ISSN 1026-4892, Vol. 59, p. 37-44Article in journal (Refereed)
  • 2769.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Peltola, Pasi
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Deposition of persistent organic pollutants under a high voltage power line2009In: Posterpresentation vid NOSA Aerosol Symposium i Lund, 12-13 november, 2009., 2009Conference paper (Other academic)
  • 2770.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Peltola, Pasi
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Increased deposition of polychlorinated biphenyls (PCBs) under an AC high voltage power line2009In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 43, no 39, p. 6168-6174Article in journal (Refereed)
    Abstract [en]

    There is considerable public concern regarding the potential risks to health of electromagnetic fields in general and high-voltage power lines in particular. As epidemiological findings are not supported by a clearly defined mechanism of direct magnetic field interactions with the human body, potential indirect effects are of interest. It has been suggested that an increased exposure to chemical pollutants could occur near high-voltage power lines due to formation and deposition of charged aerosols. The current study reports empirical evidence that seems to support this hypothesis. The deposition of 18 congeners of polychlorinated biphenyls (PCBs) was studied by collecting samples of pine needles under a 400 kV AC power line and at reference sites in the vicinity. Compared to the reference sites, the average deposition of PCB congeners under the power line was almost double. This difference between the two groups of samples was statistically significant. While it is premature to draw any conclusions regarding the human exposure near high-voltage power lines, the issue deserves attention and further investigations

  • 2771.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sander, Per
    Bergbäck, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Probabilistisk riskbedömning – fas 22006Report (Other academic)
  • 2772.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sörme, Louise
    Chemicals in statistics - a source for information on environmentally relevant compounds?2009In: 12th EuCheMS International Conference on Chemistry and the Environment i Stockholm, 14-17 juni, 2009Conference paper (Other academic)
  • 2773.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Warman, Kristofer
    Bergström, Jan
    Bromine and waste incineration: an environmental risk?1990In: Organohalogen Compounds, ISSN 1026-4892, Vol. 2, p. 339-342Article in journal (Refereed)
    Abstract [en]

    Process factors influencing the production of brominated aromatics in waste incinerators are bromine load and combustion quality. Emission measurements do not indicate unacceptable environmental risks from controlled combustion and advanced flue gas cleaning.

  • 2774.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Warman, Kristofer
    Bergström, Jan
    Distribution of toxic coplanar PCBs and PCDD/PCDF in pine needles from the Swedish environment: evaluation of data and source identification1990In: Organohalogen Compounds, ISSN 1026-4892, Vol. 1, p. 449-452Article in journal (Refereed)
    Abstract [en]

    Environmental samples from different areas of Sweden indicate a widespread contamination of toxic coplanar PCBs. Uncontrolled combustion (e.g. fires) is a likely source.

  • 2775.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Öhrström, T.
    Chlorinated aromatics from combustion: influence of chlorine, combustion conditions and catalytic activity2003In: Environmental Science & Technology, ISSN 0013-936X, Vol. 37, no 17, p. 3995-4000Article in journal (Refereed)
  • 2776.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Öhrström, Tomas
    Bergström, Jan
    Chromium as a potential catalyst in the thermal formation of chlorinated aromatic compounds2004In: Organohalogen Compounds, ISSN 1026-4892, Vol. 66, p. 1001-1005Article in journal (Refereed)
  • 2777.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Öhrström, Tomas
    Bergström & Öhrström.
    Bergström, Jan
    Bergström & Öhrström.
    Metal catalyzed formation of chlorinated aromatic compounds: a study of the correlation pattern in incinerator fly ash.2007In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 67, no 9, p. S185-S190Article in journal (Refereed)
    Abstract [en]

    Chlorinated aromatics are unintentionally formed and released from combustion and other thermal processes involving organic matter and chlorine. The catalytic activity of incinerator fly ash in the low-temperature formation of chlorinated aromatics has been demonstrated in both laboratory experiments and full-scale trials. Copper has been shown to be an effective catalyst, but several other transition metals possess a similar activity. Here results are reported from a series of full-scale combustion trials with different fractions of household and industrial wastes, with waste from forestry as a reference fuel. The composition of elements and chlorinated aromatics in the fly ash was evaluated with principal component analysis and partial least squares regression. The observed correlation pattern indicates that metals other than copper are of equal importance for the catalytic activity. Chromium and nickel are two of these metals, which may contribute to the de novo formation of chlorinated benzenes, phenols, PCDD and PCDF.

  • 2778.
    Öberg, Tomas
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Öhrström, Tomas
    Bergström, Jan
    The correlation pattern of fly ash components: Chromium as a potential catalyst in the thermal formation of chlorinated aromatic compounds2004In: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 1, no 1, p. 18-21Article in journal (Refereed)
    Abstract [en]

    Chlorinated aromatic compounds are unintentionally released from combustion sources into the environment. This thermal formation is catalyzed by fly ash components and much interest has been focussed on the role of copper. This study report results from a series of 16 full-scale trials with different fuel compositions. The correlation pattern of fly ash components seem to suggest that the catalytic effect may be due also to other metal oxychlorination catalysts. Chromium shows particularly strong and statistically significant correlations with many of the chlorinated phenols, benzenes, dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs).

  • 2779.
    Öhrberg, Pi
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Kan +1-metoden upptäcka förekomsten av dold hyperopi?2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpStudent thesis
    Abstract [sv]

    Introduktion: Vid synkontrollen hos skolsköterskan upptäcks ofta de barn som har nedsatt synskärpa, som de närsynta. Men de barnen som är översynta slinker lätt genom detta kontrollnät i och med att de kan kompensera sitt synfel genom ackommodation.

    Syfte: Syftet med denna undersökning var att se hur mycket dold översynthet det finns hos barn i lågstadiet samt för att se om +1-metoden är lämplig för detta ändamål.

    Metod: +1-metoden går ut på att det ena ögat täcks för så att det inte kan se något alls medan det andra ögat får titta genom ett glas som mäter +1 dioptrier. Den förväntade synskärpeförändringen i förhållande till barnets fria synskärpa är en minskning på 5 rader, eller en visusförsämring på 0,5 med en tavla som är indelad i decimaler. Om förändringen är mindre är inte patienten rätt korrigerad och en dold översynthet kan vara den bakomliggande orsaken.

    Resultat: Totalt deltog 27 barn i studien i årskurs 2 och 3. Vid undersökningarna visade det sig att 25,9% av skolbarnen fick en försämrad synskärpa med 0,5 eller mer med +1-metoden, alltså de var inte översynta.

    Diskussion och slutsats: Denna studie visar att +1-metoden är ett bra sätt att upptäcka dold översynthet bland barn i skolan. Metoden borde inkluderas i skolsköterskornas synscreening för att kunna fånga upp de översynta barnen som ackommoderar hela dagarna.

    2008:O26

  • 2780. Österholm, P
    et al.
    Åström, Mats
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Quantification of current and future leaching of sulphur and metals from Boreal acid sulphate soils, W. Finland2004In: Australian Journal of Soil Research, Vol. 42, p. 547-551Article in journal (Refereed)
  • 2781. Österholm, P
    et al.
    Åström, Mats
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Spatial trends and losses of major and trace elements in agricultural acid sulphate soils distributed in the artificially drained Rintala area, W. Finland2002In: Applied Geochemistry, Vol. 17, p. 1209-1218Article in journal (Refereed)
  • 2782. Österholm, P
    et al.
    Åström, Mats
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sundström, R
    Assessment of aquatic pollution, remedial measures and juridical obligations of an acid sulphate soil area in western Finland2005In: Agricultural and food science, Vol. 14 (1), p. 44-56Article in journal (Refereed)
  • 2783. Österholm, Peter
    et al.
    Åström, Mats
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Meteorological impacts on the water quality in the Pajuluoma acid sulphate soil area, W. Finland.2008In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 23, p. 1594-1606Article in journal (Refereed)
  • 2784.
    Österström, Ola
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lilja, Clas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Changes in eggshell structure and function during avian evolution2007In: Journal of Morphology 246 (12), 2007Conference paper (Refereed)
  • 2785.
    Österström, Ola
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lilja, Clas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Eggshell structure, mode of development and growth rate in birds.2008In: Zoology (Jena), ISSN 0944-2006, E-ISSN 1873-2720, Vol. 111, no 6, p. 494-502Article in journal (Refereed)
  • 2786.
    Österström, Ola
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lilja, Clas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Is the shell of an egg adapted to support different rates of calcium removal by developing embryos2006In: Journal of Ornithology 147 (5), 2006Conference paper (Refereed)
  • 2787.
    Özmen, Lisa
    et al.
    Rudbeck Laboratory, University Hospital, Uppsala.
    Nilsson Ekdahl, Kristina
    University of Kalmar, School of Pure and Applied Natural Sciences. Rudbeck Laboratory, University Hospital, Uppsala.
    Elgue, Graciela
    Rudbeck Laboratory, University Hospital, Uppsala.
    Larsson, Rolf
    Rudbeck Laboratory, University Hospital, Uppsala.
    Korsgren, Olle
    Rudbeck Laboratory, University Hospital, Uppsala.
    Nilsson, Bo
    Rudbeck Laboratory, University Hospital, Uppsala.
    Inhibition of Thrombin Abrogates the Instant Blood-Mediated Inflammatory Reaction Triggered by Isolated Human Islets: Possible application of the thrombin inhibitor melagatran in clinical islet transplantation2002In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 51, no 6, p. 1779-1784Article in journal (Refereed)
    Abstract [en]

    A thrombotic/inflammatory reaction is elicited when isolated islets of Langerhans come in contact with ABO-compatible blood. The detrimental effects of this instant blood-mediated inflammatory reaction (IBMIR) provide a reasonable explanation for the observation that an unexpectedly high number of islets, from several donors, are needed to produce normoglycemia in transplant patients with type 1 diabetes. In this study, the hypothesis that a specific thrombin inhibitor, Melagatran, could reduce IBMIR in an in vitro model in which human islets are exposed to ABO-compatible blood was tested. The administration of Melagatran abrogated IBMIR dose-dependently. Islets exposed to blood, in the absence or presence of 0.4 μmol/l Melagatran, exhibited a loss of integrity and were found to be trapped in macroscopic clots containing platelets and CD11b+ leukocytes. At concentrations from 1 to 10 μmol/l, Melagatran inhibited both coagulation and complement activation. Also, platelet and leukocyte activation and consumption were decreased. Islet morphology was maintained with almost no platelets adhering to the surface, and infiltration by CD11b+ leukocytes was considerably reduced. In conclusion, Melagatran significantly reduced IBMIR in this model system. This protective effect indicates that thrombin plays a pivotal role in IBMIR and suggests that thrombin inhibition can improve the outcome of clinical islet transplantation.

53545556 2751 - 2787 of 2787
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