| 1. |
- Hollestelle, Antoinette, et al.
(författare)
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No clinical utility of KRAS variant rs61764370 for ovarian or breast cancer
- 2016
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Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 141:2, s. 386-401
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Tidskriftsartikel (refereegranskat)abstract
- Objective Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3′ UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370. Methods Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers). Results We found no association with risk of ovarian cancer (OR = 0.99, 95% CI 0.94-1.04, p = 0.74) or breast cancer (OR = 0.98, 95% CI 0.94-1.01, p = 0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR = 1.09, 95% CI 0.97-1.23, p = 0.14, breast cancer HR = 1.04, 95% CI 0.97-1.12, p = 0.27; BRCA2, ovarian cancer HR = 0.89, 95% CI 0.71-1.13, p = 0.34, breast cancer HR = 1.06, 95% CI 0.94-1.19, p = 0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR = 0.94, 95% CI 0.83-1.07, p = 0.38), breast cancer (HR = 0.96, 95% CI 0.87-1.06, p = 0.38), and all other previously-reported associations. Conclusions rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.
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| 2. |
- Kaplan, Bartek, et al.
(författare)
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Thermodynamic analysis of the Co-Cr-C system
- 2014
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Ingår i: Calphad. - : Elsevier BV. - 0364-5916 .- 1873-2984. ; 46, s. 226-236
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Tidskriftsartikel (refereegranskat)abstract
- A reassessment of the thermodynamic description of the Co-Cr-C system was performed to take into account recent experimental information on the solubility of Co in Cr-based carbides. Density Functional Theory (DFT) calculations coupled with phonon calculations were performed to calculate the heat capacity and Gibbs energies of formation of stable and metastable carbides in the Co-Cr-C system as a function of temperature, within the limits of the Harmonic or the Quasi Harmonic Approximation. Resulting Gibbs energies were compared with earlier experimental studies and assessments, where calculated values for Cr23C6, Cr7C3 and Cr3C2 from the present work were seen to fall within the experimental scatter. The calculated heat capacity and Gibbs energy of formation as a function of temperature for the metastable Co3C2 compound together with recent experimental information was used in the evaluation of the thermodynamic parameters. As a result, the new and improved thermodynamic description accounts for the solubility of Co in M3C2 in contrast to previous descriptions, where this was neglected due to a complete lack of experimental information. Furthermore, a better representation of previously reported liquidus temperatures was achieved, without increasing the number of parameters in the liquid phase. Other relevant features of the phase diagram and thermochemical properties were also well represented.
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| 3. |
- Ahuja, Rajeev, et al.
(författare)
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Relativity and the lead–acid battery
- 2011
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 106:1, s. 018301-
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Tidskriftsartikel (refereegranskat)abstract
- The energies of the solid reactants in the lead-acid battery are calculated ab initio using two different basis sets at nonrelativistic, scalar-relativistic, and fully relativistic levels, and using several exchange-correlation potentials. The average calculated standard voltage is 2.13 V, compared with the experimental value of 2.11 V. All calculations agree in that 1.7-1.8 V of this standard voltage arise from relativistic effects, mainly from PbO2 but also from PbSO4.
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| 4. |
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| 5. |
- Araujo, Carlos Moyses, et al.
(författare)
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Disorder-induced Room Temperature Ferromagnetism in Glassy Chromites
- 2014
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4, s. 4686-
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Tidskriftsartikel (refereegranskat)abstract
- We report an unusual robust ferromagnetic order above room temperature upon amorphization of perovskite [YCrO3] in pulsed laser deposited thin films. This is contrary to the usual expected formation of a spin glass magnetic state in the resulting disordered structure. To understand the underlying physics of this phenomenon, we combine advanced spectroscopic techniques and first-principles calculations. We find that the observed order-disorder transformation is accompanied by an insulator-metal transition arising from a wide distribution of Cr-O-Cr bond angles and the consequent metallization through free carriers. Similar results also found in YbCrO3-films suggest that the observed phenomenon is more general and should, in principle, apply to a wider range of oxide systems. The ability to tailor ferromagnetic order above room temperature in oxide materials opens up many possibilities for novel technological applications of this counter intuitive effect.
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| 6. |
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| 7. |
- Arvidsson, Anna K, 1971-, et al.
(författare)
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Dynamisk prognosstyrd vinterväghållning – fas 3 & 4 : restsaltmodeller och automatisk saltspridning
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I ett föränderligt klimat där allt större krav ställs på väghållare och vinterdriftsentreprenörer att åstadkomma en för trafikanterna acceptabel vintersdriftstandard samtidigt som de ekonomiska resurserna blir alltmer begränsade, ökar behoven av kostnadseffektiva metoder. Prognosstyrd dynamisk vägdrift har visat sig kunna leda till en ökad produktivitet då väglagsprognoser integreras med ruttoptimering. Ett sätt att vidareutveckla väglagsprognoserna är att veta hur mycket salt som behövs på vägen, eller mer exakt, hur mycket salt finns kvar? Om det redan finns salt på vägen, behöver du inte sprida hela mängden, det kan räcka med hälften eller ännu mindre. Restsaltmätningar har gjorts under tre vintersäsonger vid Testsite E18. Platsen valdes eftersom den är utrustad med flera olika sensorer, monterade över, bredvid och i vägen. Salt mättes var trettionde centimeter tvärs över vägens två körfält. Av 9 mätningar var det bara 5 tillfällen med salt varav två av dem saltades enbart för våra mätningar, kvar var tre mätningar med vinterförhållanden. Alla mätningar som gjordes jämfördes med sensorer monterade på testplatsen för att jämföra hur väl en sensor representerar vägytan. Det visade sig att det generellt var väldigt låga saltvärden från de monterade sensorerna jämfört med de manuella mätningarna.
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| 8. |
- Berseth, P. A., et al.
(författare)
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Carbon Nanomaterials as Catalysts for Hydrogen Uptake and Release in NaAlH4
- 2009
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Ingår i: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 9:4, s. 1501-1505
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Tidskriftsartikel (refereegranskat)abstract
- A synergistic approach involving experiment and first-principles theory not only shows that carbon nanostructures can be used as catalysts for hydrogen uptake and release in complex metal hydrides such as sodium alanate, NaAlH4, but also provides an unambiguous understanding of how the catalysts work. Here we show that the stability of NaAlH4 originates with the charge transfer from Na to the AlH4 moiety, resulting in an ionic bond between Na+ and AlH4- and a covalent bond between Al and H. Interaction of NaAlH4 with an electronegative substrate such as carbon fullerene or nanotube affects the ability of Na to donate its charge to AlH4, consequently weakening the Al-H bond and causing hydrogen to desorb at lower temperatures as well as facilitating the absorption of H-2 to reverse the dehydrogenation reaction. In addition, based on our experimental observations and theoretical calculations it appears the curvature of the carbon nanostructure plays a role in the catalytic process. Ab initio molecular dynamics simulation further reveals the time evolution of the charge transfer process.
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| 9. |
- Bigdeli, Sedigheh, et al.
(författare)
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DFT based calculations of thermodynamic properties for paramagnetic bcc-Mn at high temperatures
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In developing the third generation of Calphad databases, density-functional-theory methods are particularly important for validating physical models and for providing input data where experiment is unavailable. Since Cal-phad modelling needs data at finite temperatures additional sampling tech-niques are required, and the recently developed TU-TILD method is one such technique that allows for an efficient and accurate calculation of free energies. It is used in the present work for the complicated paramagnetic bcc phase of Mn. Our results show a good agreement with experimental data, validating that this method is well suited for calculating thermody-namic properties of magnetically complex and dynamically unstable phases as needed for Calphad modelling. It is also shown that a transition from bcc to the ω phase occurs below 1200 K.
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| 10. |
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| 11. |
- Blanton, Michael R., et al.
(författare)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Tidskriftsartikel (refereegranskat)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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| 12. |
- Blomqvist, Andreas, et al.
(författare)
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Dehydrogenation from 3d-transition-metal-doped NaAlH4 : Prediction of catalysts
- 2007
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 90:14
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Tidskriftsartikel (refereegranskat)abstract
- A fundamental understanding of the role of catalysts in improving the kinetics and thermodynamics of hydrogen sorption in NaAlH4 is the key for using this material in hydrogen storage. The authors present a systematic theoretical study of energies needed to desorb hydrogen in 3d transition metal (Sc-Cu)-doped NaAlH4. They show that Cr and Fe atoms can be far more effective catalysts than Ti in desorbing hydrogen. The role of the 3d metal atoms in improving the thermodynamics of dehydrogenation is attributed to a significant shortening of the bond length with neighboring Al atoms.
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| 13. |
- Blomqvist, Andreas, et al.
(författare)
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Hydrogen as promoter and inhibitor of superionicity : A case study on Li-N-H systems
- 2010
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 82:2, s. 024304-
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Tidskriftsartikel (refereegranskat)abstract
- Materials which possess a high lithium ion conductivity are very attractive for battery and fuel cell applications. Hydrogenation of the fast-ion conductor lithium nitride (Li3N) leads to the formation of lithium imide (Li2NH) and subsequently of lithium amide (LiNH2). Using ab initio molecular dynamics simulations, we carried out a comparative study of the Li diffusion in these three systems. The results demonstrate that hydrogen can work as both promoter and inhibitor of Li mobility, with the lowest transition temperature to the superionic state occurring in Li2NH. Furthermore, we show that the creation of Li vacancies strongly affects Li diffusion in Li3N, but not so in Li2NH. Finally, we explain our findings with the help of a simple model.
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| 14. |
- Blomqvist, Andreas
(författare)
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Insights into Materials Properties from Ab Initio Theory : Diffusion, Adsorption, Catalysis & Structure
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, density functional theory (DFT) calculations and DFT based ab initio molecular dynamics simulations have been employed in order to gain insights into materials properties like diffusion, adsorption, catalysis, and structure. In transition metals, absorbed hydrogen atoms self-trap due to localization of metal d-electrons. The self-trapping state is shown to highly influence hydrogen diffusion in the classical over-barrier jump temperature region. Li diffusion in Li-N-H systems is investigated. The diffusion in Li3N is shown to be controlled by the concentration of vacancies. Exchanging one Li for H (Li2NH), gives a system where the diffusion no longer is dependent on the concentrations of vacancies, but instead on N-H rotations. Furthermore, exchanging another Li for H (LiNH2), results in a blockade of Li diffusion. For high-surface area hydrogen storage materials, metal organic frameworks and covalent organic frameworks, the hydrogen adsorption is studied. In metal organic frameworks, a Li-decoration is also suggested as a way to increase the hydrogen adsorption energy. In NaAlH4 doped with transition metals (TM), the hypothesis of TM-Al intermetallic alloys as the main catalytic species is supported. The source of the catalytic effect of carbon nanostructures on hydrogen desorption from NaAlH4 is shown to be the high electronegativity of the carbon nanostructures. A space-group optimized ab initio random structure search method is used to find a new ground state structure for BeC2 and MgC2. The fast change between the amorphous and the crystalline phase of GeSbTe phase-change materials is suggested to be due to the close resemblance between the local amorphous structure and the crystalline structure. Finally, we show that more than 80% of the voltage in the lead acid battery is due to relativistic effects.
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| 15. |
- Blomqvist, Andreas, et al.
(författare)
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Significance of self-trapping on hydrogen diffusion
- 2010
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 105:18, s. 185901-
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Tidskriftsartikel (refereegranskat)abstract
- The diffusion rate of hydrogen in Nb was calculated using ab initio molecular dynamics simulations. At low temperatures the hydrogen is strongly trapped in a local strain field which is caused by the elastic response of the lattice. At elevated temperatures, the residence time (τ) of hydrogen in an interstitial site is not sufficient for fully developing the local strain field. This unbinding of the interstitial hydrogen and the strain field increases the hopping rate (1/τ) at elevated temperatures (>400 K). These results call for a revision of the conceptual framework of diffusion of hydrogen in transition metals at elevated temperatures.
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| 16. |
- Blomqvist, Andreas, et al.
(författare)
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Usability and feasibility analysis of an mHealth-tool for supporting physical activity in people with heart failure
- 2024
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Ingår i: BMC Medical Informatics and Decision Making. - : BMC. - 1472-6947. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPhysical inactivity and a sedentary lifestyle are common among people with heart failure (HF), which may lead to worse prognosis. On an already existing mHealth platform, we developed a novel tool called the Activity coach, aimed at increasing physical activity. The aim of this study was to evaluate the usability of the Activity coach and assess feasibility of outcome measures for a future efficacy trial.MethodsA mixed-methods design was used to collect data. People with a HF diagnosis were recruited to use the Activity coach for four weeks. The Activity coach educates the user about physical activity, provides means of registering daily physical activity and helps the user to set goals for the next week. The usability was assessed by analysing system user logs for adherence, reported technical issues and by interviews about user experiences. Outcome measures assessed for feasibility were objective physical activity as measured by an accelerometer, and subjective goal attainment. Progression criteria for the usability assessment and for the proposed outcomes, were described prospectively.ResultsTen people with HF were recruited, aged 56 to 78 with median age 72. Data from nine of the ten study participants were included in the analyses. Usability: The Activity coach was used 61% of the time and during the first week two study participants called to seek technical support. The Activity coach was found to be intuitive and easy to use by all study participants. An increased motivation to be more physically active was reported by six of the nine study participants. However, in spite of feeling motivated, four reported that their habits or behaviours had not been affected by the Activity coach. Feasibility: Data was successfully stored in the deployed hardware as intended and the accelerometers were used enough, for the data to be analysable. One finding was that the subjective outcome goal attainment, was challenging to collect. A proposed mitigator for this is to use pre-defined goals in future studies, as opposed to having the study participants be completely free to formulate the goals themselves.ConclusionsIt was confirmed that the Activity coach was easy to use. Furthermore, it might stimulate increased physical activity in a population of people with HF, who are physically inactive. The outcomes investigated seem feasible to include in a future efficacy trial.Trial registrationClinicalTrials.gov identifier: NCT05235763. Date of first registration: 11/02/2022.
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| 17. |
- Blomqvist, Andreas, et al.
(författare)
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Utility of single-item questions to assess physical inactivity in patients with chronic heart failure
- 2020
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Ingår i: ESC Heart Failure. - : WILEY PERIODICALS, INC. - 2055-5822. ; 7:4, s. 1467-1476
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Tidskriftsartikel (refereegranskat)abstract
- Aim The purpose of this study was to explore the utility of two single-item self-report (SR) questions to assess physical inactivity in patients with heart failure (HF). Methods and results This is a cross-sectional study using data from 106 patients with HF equipped with accelerometers for 1 week each. Two SR items relating to physical activity were also collected. Correlations between accelerometer activity counts and the SR items were analysed. Patients were classified as physically active or inactive on the basis of accelerometer counts, and the SR items were used to try to predict that classification. Finally, patients were classified as having high self-reported physical activity or low self-reported physical activity, on the basis of the SR items, and the resulting groups were analysed for differences in actual physical activity. There were significant but weak correlations between the SR items and accelerometer counts: rho = 0.24, P = 0.016 for SR1 and rho = 0.21, P = 0.033 for SR2. Using SR items to predict whether a patient was physically active or inactive produced an area under the curve of 0.62 for SR1, with a specificity of 92% and a sensitivity of 30%. When dividing patients into groups on the basis of SR1, there was a significant difference of 1583 steps per day, or 49% more steps in the high self-reported physical activity group (P < 0.001). Conclusions There might be utility in the single SR question for high-specificity screening of large populations to identify physically inactive patients in order to assign therapeutic interventions efficiently where resources are limited.
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| 18. |
- Blomqvist, Christopher, et al.
(författare)
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Joint Handwritten Text Recognition and Word Classification for Tabular Information Extraction
- 2022
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Ingår i: 2022 26th International Conference on Pattern Recognition (ICPR). - 9781665490634 - 9781665490627 ; , s. 1564-1570
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present a system for extracting tabular information from loosely structured handwritten documents. The system consists of three parts, (i) a u-net like CNN-based method for text detection and segmentation, (ii) a new attention-based method for simultaneous text recognition and classification of word-parts, and (iii) a method for matching the word parts into a tabular structure for each entry. A key contribution is the observation that the new attention-based recognition and classification module makes it possible for improved spatial analysis of the tabular information. The method is evaluated on a unique historical document: The Swedish Wealth Tax of 1571, consisting of 11,453 pages of hand-written tax records. The evaluation shows that the system provides a significant improvement to the state-of-the-art to the problem of tabular extraction from loosely structured historical documents.
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| 19. |
- Blomqvist, Christopher, et al.
(författare)
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Reading the ransom: Methodological advancements in extracting the Swedish Wealth Tax of 1571
- 2023
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Ingår i: Explorations in Economic History. - : Elsevier BV. - 0014-4983. ; 87
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Tidskriftsartikel (refereegranskat)abstract
- We describe a deep learning method to read hand-written records from the 16th century. The method consists of a combination of a segmentation module and a Handwritten Text Recognition (HTR) module. The transformer-based HTR module exploits both language and image features in reading, classifying and extracting the position of each word on the page. The method is demonstrated on a unique historical document: The Swedish Wealth Tax of 1571. Results suggest that the segmentation module performs significantly better than the lay-out analysis implemented in state-of-the art programs, enabling us to trace many more text blocks correctly on each page. The HTR module has a low character error rate (CER), in addition to being able to classify words and help organize them into tabular formats. By demonstrating an automated process to transform loosely structured handwritten information from the 16th century into organized tables, our method should interest economic historians seeking to digitize and organize quantitative material from pre-industrial periods.
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| 20. |
- Blomqvist, Evalena, et al.
(författare)
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Samförbränning av bilfluff, rötslam och avfall i en 20 MW fluidbäddpanna - Studier av bränslesammansättningens påverkan på beläggningsbildning
- 2007
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Rapport (refereegranskat)abstract
- In order to prevent a further increased use of resources and to decrease the environmental impact from landfills, organic wastes are today diverted towards material and energy recovery. This creates a waste market with an increasing number of waste fractions that needs to be treated properly. As an example, in Sweden it has recently been prohibited to landfill source separated combustible waste (2002) and organic waste (2005). Wastes as automotive shredder residue (ASR) and sewage sludge can no longer be landfilled and needs to be either material or energy recovered, which challenge the waste treatment sector. This work investigates the effects of ASR and sewage sludge co-combustion in a 20 MW Energy-from-Waste plant (bubbling fluidised bed). The long term objective of the work is to increase the fuel flexibility, the boiler availability and the power production. This report focus on boiler operation and combustion performance in terms of agglomeration, deposit rates and emissions. In addition to the tests with ASR and sewage sludge, repeated measurements were performed during normal load as a reference. The results show that the co-combusted fractions of ASR and sewage sludge, which on mass basis constituted 6 % and 15 % respectively, did not increase the risk for agglomeration or deposits on heat-exchanging surfaces. Instead, compared to the two reference cases, the deposit rates decreased when sewage sludge was added. Only minor variation in the emissions was seen between the different cases. The levels of I-TEQs were far below the legislated values in all cases.
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| 21. |
- Blomqvist, Marjut, 1966-
(författare)
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Health among people with psychotic disorders and effects of an individualized lifestyle intervention to promote health
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of the thesis was to increase knowledge of health among people with psychotic disorders such as schizophrenia and other long-term psychotic conditions. The aim was also to investigate health effects, in terms of clinical health outcomes and self-reported questionnaires, of atwo-year individualized lifestyle intervention implemented in psychiatric outpatient services involving cooperation with the municipal social psychiatry services. The motivation for the study was to generate new knowledge in order to be able to promote health in people with psychotic disorders and to improve the care and support provided for this target group. The thesis consists of four studies. A quantitative study (Study I), was conducted using a cross-sectional design to investigate the prevalence of overweight, obesity, risk of cardiovascular disease (CVD) and the relationships between self-rated salutogenic health, sense of coherence, CVD risk, and body mass index among people with psychoticdisorders (n=57). The study was conducted in four psychiatric outpatient services; questionnaires were completed by the participants and clinical health measurements were collected by the participant’s contact nurse at the psychiatric outpatient services. The participants showed a moderate/high risk of CVD, the mean for BMI was 31.9 (59.6% were obese) and 31.6% were overweight. The results did not reveal any relationships between the subjective and objective measuresof health indicating the need for both subjective and objective assessments of health in psychiatric care. In a qualitative study (Study II), data were collected with semi-structured interviews (n=16) andanalyzed with qualitative content analysis. The interviews resulted in an overall theme “Being regarded as a whole human being by self and others”, which showed the multidimensional nature of health and the issues that enable healthy living among people with severe mental illness. Three categories emerged: (i) everyday structure (ii), motivating life events and (iii) support from significant others. The results indicate that a person with severe mental illness needs to be encountered as a wholeperson if healthy living is to be enabled. In a quasi-experimental study (Study III), the potential effects of participation in the two-year lifestyle intervention (intervention group n=54 and control group (n=13) were investigated. The data were collected at baseline, after 12 months and after 24 months using the self-reported questionnaire the Salutogenic Health Indicator Scale (SHIS), the Hopkins Symptom Checklist (HSCL-25) and the National Public Health Survey. Measures of clinical healthoutcomes were conducted by the participant’s contact nurse at the psychiatric outpatient services. Multilevel modeling was used to test differences in changes over time. Significant changes were foundin physical activity, HbA1c and waist circumference after participation in individualized lifestyle intervention. The relationship between changes in physical activity, levels of salutogenic health and glycated hemoglobin (Hb1Ac) were investigated (n=54) in Study IV. The data were collected atbaseline, after 12 months and after 24 months using the self-reported questionnaires Salutogenic Health Indicator Scale (SHIS) and National Public Health Survey. Within-person changes in physical activity between baseline and at the end of the twenty-four-month intervention were calculated. Selfreported increased physical activity was positively associated with self-rated salutogenic health and negatively associated with level of HbA1c after participation in the intervention. The thesis shows that a well-founded assessment of general health needs must consider both the individual's subjective experiences and objective measurements in order to form a solid foundation for dialogue and shareddecision-making about essential care services. The results also show that it is possible to stimulate healthy behavioral changes with a two-year individualized lifestyle intervention and bring both subjectively and objectively measured health benefits for people with psychotic disorders. The importance of nurses in psychiatric care applying a holistic approach and integrating lifestyle interventions into daily person-centered psychiatric care in collaboration with other healthcare providers to facilitate changes towards a healthy lifestyle in persons with psychotic illness is emphasized in the thesis.
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| 22. |
- Blomqvist, Marjut, 1966-, et al.
(författare)
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Health effects of an individualized lifestyle intervention for people with psychotic disorders in psychiatric outpatient services : a two year follow-up
- 2019
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Ingår i: Issues in Mental Health Nursing. - Philadelphia : Taylor & Francis. - 0161-2840 .- 1096-4673. ; 40:10, s. 839-850
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Tidskriftsartikel (refereegranskat)abstract
- People with psychotic disorders experience to a great extent avoidable physical illnesses and early mortality. The aim of the study was to investigate the potential effects for this group of participating in a lifestyle intervention. A multi-component nurse-led lifestyle intervention using quasi-experimental design was performed. Changes in biomedical and clinical measurements, self-reported health, symptoms of illness and health behavior were investigated. Multilevel modeling was used to statistically test differences in changes over time. Statistically significant changes were found in physical activity, HbA1c and waist circumference. A lifestyle intervention for people with severe mental illness can be beneficial for increasing physical activity.
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| 23. |
- Blomqvist, Marjut, 1966-, et al.
(författare)
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Health risks among people with severe mental illness in psychiatric outpatient settings
- 2018
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Ingår i: Issues in Mental Health Nursing. - Philadelphia : Taylor & Francis. - 0161-2840 .- 1096-4673. ; 39:7, s. 585-591
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Tidskriftsartikel (refereegranskat)abstract
- Life expectancy is greatly reduced in patients with schizophrenia, and cardiovascular diseases are a leading cause of mortality. The aim of this cross-sectional study was to investigate the prevalence of overweight, obesity, and cardiovascular disease (CVD) risk and to investigate the relationships between self-rated health, sense of coherence, CVD risk, and body mass index (BMI) among people with severe mental illness (SMI) in psychiatric outpatient settings. Nearly 50% of the participants were exposed to moderate/high risk of CVD and over 50% were obese. The results showed no statistically relationships between the subjective and objective measures (Bayes factor <1) of health. The integration of physical health into clinical psychiatric nursing practice is vital.
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| 24. |
- Blomqvist, Marjut, 1966-, et al.
(författare)
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Relationship between Physical Activity and Health Outcomes in Persons with Psychotic Disorders after Participation in a 2-Year Individualized Lifestyle Intervention
- 2023
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Ingår i: Issues in Mental Health Nursing. - Philadelphia, PA : Taylor & Francis. - 0161-2840 .- 1096-4673. ; 44:7, s. 629-638
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Tidskriftsartikel (refereegranskat)abstract
- People with psychotic disorders have a significantly increased risk of physical diseases and excessive mortality rates. The aim of the study was to investigate relationships between changes in physical activity, levels of salutogenic health, and glycated hemoglobin among people with psychotic disorders after participation in an individualized lifestyle intervention. The results from analyses showed that self-reported increased physical activity was positively associated with the level of salutogenic health and negatively associated with the level of HbA1c on an individual level. The results indicate that coordinated, individualized, holistic and health-promoting nursing care is crucial to enabling enhanced lifestyle within this vulnerable target group. © 2023 The Author(s). Published with license by Taylor & Francis Group, LLC.
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| 25. |
- Borgh, Ida, et al.
(författare)
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Synthesis and phase separation of (Ti,Zr)C
- 2014
-
Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 66, s. 209-218
-
Tidskriftsartikel (refereegranskat)abstract
- Synthesis and phase separation of (Ti,Zr)C were investigated in the present work. The (Ti,Zr)C phase was synthesized at 2200 C and subsequently aged at 1300 C for different times. The microstructure was investigated using X-ray diffraction and electron microscopy, and supplemented by first-principles calculations. The (Ti,Zr)C phase separates into a lamellar nanostructure with alternating Ti- and Zr-rich face-centered cubic domains as well as non-stoichiometric TiC and ZrC. The lamellar structure is a consequence of phase separation within the miscibility gap that is directionally constrained by high coherency stresses, as indicated by the first-principles calculations. Moreover, the increased hardness due to the phase separation suggests that the mixed carbide could be used as a strengthening constituent in, for example, cemented carbides.
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| 26. |
- Cederwall, Bo, et al.
(författare)
-
Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd
- 2011
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 469:7328, s. 68-71
-
Tidskriftsartikel (refereegranskat)abstract
- Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Dahl, Andreas, et al.
(författare)
-
Traffic-generated emissions of ultrafine particles from pavement-tire interface
- 2006
-
Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 40:7, s. 1314-1323
-
Tidskriftsartikel (refereegranskat)abstract
- In a road simulator study, a significant source of sub-micrometer fine particles produced by the road-tire interface was observed. Since the particle size distribution and source strength is dependent on the type of tire used, it is likely that these particles largely originate from the tires, and not the road pavement. The particles consisted most likely of mineral oils from the softening filler and fragments of the carbon-reinforcing filler material (soot agglomerates). This identification was based on transmission electron microscopy studies of collected ultrafine wear particles and on-line thermal treatment using a thermodesorber. The mean particle number diameters were between 15-50 nm, similar to those found in light duty vehicle (LDV) tail-pipe exhaust. A simple box model approach was used to estimate emission factors in the size interval 15-700 nm. The emission factors increased with increasing vehicle speed, and varied between 3.7 x 10(11) and 3.2 x 10(12) particles vehicle(-1) km(-1) at speeds of 50 and 70 km h(-1). This corresponds to between 0.1-1% of tail-pipe emissions in real-world emission studies at similar speeds from a fleet of LDV with 95% gasoline and 5% diesel-fueled cars. The emission factors for particles originating from the road-tire interface were, however, similar in magnitude to particle number emission factors from liquefied petroleum gas-powered vehicles derived in test bench studies in Australia 2005. Thus the road-tire interface may be a significant contributor to particle emissions from ultraclean vehicles. (c) 2005 Elsevier Ltd. All rights reserved.
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| 31. |
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| 32. |
- Edin, Emil, 1987-
(författare)
-
Computational Insights into Atomic Scale Wear Processes in Cemented Carbides
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As Ti-alloys become more and more utilized the need for efficient and robust manufacturing of Ti-alloy components increase in importance. Ti-alloys are more difficult to machine than e.g. steel, mainly due to their poor thermal conductivity leading to rapid tool wear. The atomic scale processes responsible for this wear is not well understood. Here the focus is turned to the effects of C diffusion out of the tools as a source of the observed wear. A combination of Density Functional Theory (DFT) making use of Harmonic Transition State Theory (HTST), classical Molecular Dynamics (MD) and kinetic Monte Carlo (kMC) is used to investigate C diffusion into and within experimentally observed WC/W interfaces that exists as a consequence of the C depletion. Further, tools are built and used to evaluate interface parameters for large sets of interfaces within the WC/W system to determine which are energetically preferred. The results from the DFT study show stable interfaces with large differences in activation energy between the two most prominent surfaces found in WC materials, namely the basal and prismatic surfaces. Within the WC/W interfaces the diffusion barriers are similar between the two. The classical MD simulations support the view of stable interfaces at the early stages of C depletion. As C is removed this picture shifts to one in which the diffusion barriers are substantially decreased and the difference between the basal and the prismatic interfaces vanish pointing to a process which starts out slow but accelerates as C is continually removed. From the kMC simulations the overall diffusion pre-factor and activation energy is estimated to be D0=1.8x10-8 m2/s and dE=1.24 eV for the investigated [10-10]-I/[100] interface, the kMC simulations also confirm previous results indicating that the diffusion is restricted to the interface region. The investigation and screening of properties for WC/W interfaces show a preference for the W terminated [10-10]-I/[110] and [0001]/[110] interface combinations based on the interfacial energy.
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| 33. |
- Edin, Emil, et al.
(författare)
-
First principles study of C diffusion in WC/W interfaces observed in WC/Co tools after Ti-alloy machining
- 2019
-
Ingår i: Computational materials science. - : ELSEVIER SCIENCE BV. - 0927-0256 .- 1879-0801. ; 161, s. 236-243
-
Tidskriftsartikel (refereegranskat)abstract
- Ti-alloys have many qualities making them ideal for use in aerospace applications, medical implants and chemical industries such as high strength to weight ratio, good high temperature strength and chemical stability. One downside to Ti-alloys is, however, that they are considered difficult to machine. Several investigations have been made in order to understand the wear mechanisms present in machining of Ti-alloys and the most common understanding is a combination of attrition and dissolution-diffusion. Observations by Odelros et al. [1] have shown that there exists a small layer of pure bcc W on top of the outermost WC grains after turning of Ti-6Al-4V. In order for such a layer to form C has to diffuse away from the WC leaving behind only W. In this work Density Functional Theory (DFT) is used together with Harmonic Transition State Theory (HTST) to investigate the prefactors and barriers for C diffusion into and within two different WC/W interfaces, [0001]/[111] and [10 (1) over bar0]/[100]. The diffusion into the interfaces show that the barrier for the [0001]/[111] interface is more than twice as high as the barrier for the [10 (1) over bar0]/[100] interface. Diffusion within the interfaces show, on average, slightly higher barriers for the [0001]/[111] interface.
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| 34. |
- Edin, Emil, et al.
(författare)
-
interfaceBuilder, a python tool for building and analyzing interfaces suitable for use in large screening applications
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Interfaces in materials are of importance in a large number of applications. In order to gain a better understanding of interfaces, their structures, their properties, and processes related to them and to be able to predict which interfaces are most likely to form, easy to use tools are needed for finding, constructing, storing and analyzing interfaces. Presented here is a free python package which allows for the finding and storing of the lowest strain interfaces between base structures at different relative rotations. Further, the package allows for fast and easy analysis of interface datasets by including standardized containers for interface properties and a large number of tools designed for visualization and analysis of geometric parameters as well as properties calculated using third party software and loaded back in to the original dataset. The package is well suited to be part of large scale screening searches of interface parameters which is demonstrated here by the calculation of the work of adhesion for 5000 interfaces, each with three different relative translations, in the interface system made up of the [100]/[110] surfaces of BCC W.
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| 35. |
- Edin, Emil, et al.
(författare)
-
Large-Scale Screening of Interface Parameters in the WC/W System Using Classical Force Field and First-Principles Calculations
- 2021
-
Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 125:6, s. 3631-3639
-
Tidskriftsartikel (refereegranskat)abstract
- To understand the observed wear in WC/Co tools during machining of Ti-alloys, it is important to know which interfaces are present in the tool-workpiece contact zone. It has been shown that WC grains in contact with the workpiece form a C depleted layer consisting of BCC W, and as such, knowledge of which WC/W interfaces can be expected and which interfaces can be used as starting points for further computations are of great importance. Here, this is studied by the systematic construction of interfaces and evaluation of the work of adhesion and interfacial energies of 60,000 unique interfaces spread across six different interface systems made up of the basal and prismatic surfaces of WC and the low index surfaces of BCC W. Calculations are made using a classical approach in LAMMPS as well as subset analysis using first principles in VASP (Vienna Ab Initio Simulation Package). The results show trends as functions of strain and system size giving a large-scale overview of this system and finding the energetically preferred interface combination to be the type-I, W-terminated prismatic WC surface against the [110] surface of BCC W.
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| 36. |
- Edin, Emil, et al.
(författare)
-
MD study of C diffusion in WC/W interfaces observed in cemented carbides
- 2019
-
Ingår i: International journal of refractory metals & hard materials. - : ELSEVIER SCI LTD. - 0263-4368. ; 85
-
Tidskriftsartikel (refereegranskat)abstract
- WC/Co tool used in the turning of Ti-alloys are subject to rapid crater wear due to chemical processes at the tool chip interface in the form of dissolution/diffusion. It has been observed that a thin layer of bcc W forms on the outermost WC grains in contact with the Ti workpiece meaning that C has diffused away from the WC. The rates involved in this process are of interest for formulating a theory of how wear progresses during turning of Ti-alloys. In this work we investigate the rates involved in this diffusion process by means of classical MD simulations on 6 different WC/W interfaces, 3 with a basal WC surface and 3 with a prismatic WC surface, as a function of C depletion in the outermost WC layer. The results show that all interfaces are stable and that principally no diffusion events of C occur at temperatures below 1373 K for C depletion levels below 30 at.%. At 50 at.% depletion, C diffusion starts occurring regularly and at 70 at.% depletion and above the majority of the C atoms are diffusing except at the lowest temperatures. Additionally, any difference in diffusion rate observed between the basal and prismatic interfaces in their pristine states have vanished at the point of 50 at.% depletion. This all points to a process which is initially slow for each layer of the WC but which increases in speed substantially as C atoms are removed.
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| 37. |
- Edin, Emil, et al.
(författare)
-
Study of C diffusion in WC/W boundaries using Adaptive Kinetic Monte Carlo
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Wear of WC/Co tools during turning of Ti-alloys is a big concern within the tooling industry. The wear is mainly attributed chemical wear in the form of diffusion/dissolution of tool material in the material of the workpiece. The reasons for these processes being so pronounced are in large part due to the low thermal conductivity of Ti which results in very high cutting zone temperatures. Experimental investigations have shown that a layer of BCC W forms on the outermost WC grains in contact with the workpiece. The process by which this layer forms must be through the diffusion of C away from the tool as W is only present in the contact in the form of tool material. The rate of this C diffusion is of importance in understanding the atomic scale processes responsible for the observed wear. In this work Kinetic Monte-Carlo is used to estimate the diffusion rate of C in WC/W interfaces and gain an understanding of the diffusion behaviour within these systems at timescales beyond previous computational investigations. The results show that C diffusion is restricted to the interface region and that it follows the paths set by the bottom surface of the BCC W, within the [10$\bar{1}$0]-I/[100] interface the estimated overall diffusion rate has a barrier of $\Delta E=1.24\pm 0.2$ eV and a pre-factor of $D_0=1.6\times10^{-8} \pm 3.8\times10^{-8}$ m$^{2}$/s estimated from calculations of the Mean Square Displacement at temperatures of 1173 K, 1073 K, 973 K and 873 K.
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| 38. |
- Fritz, Michael, et al.
(författare)
-
Prostaglandin-dependent modulation of dopaminergic neurotransmission elicits inflammation-induced aversion in mice
- 2016
-
Ingår i: Journal of Clinical Investigation. - : AMER SOC CLINICAL INVESTIGATION INC. - 0021-9738 .- 1558-8238. ; 126:2, s. 695-705
-
Tidskriftsartikel (refereegranskat)abstract
- Systemic inflammation causes malaise and general feelings of discomfort. This fundamental aspect of the sickness response reduces the quality of life for people suffering from chronic inflammatory diseases and is a nuisance during mild infections like common colds or the flu. To investigate how inflammation is perceived as unpleasant and causes negative affect, we used a behavioral test in which mice avoid an environment that they have learned to associate with inflammation-induced discomfort. Using a combination of cell-type-specific gene deletions, pharmacology, and chemogenetics, we found that systemic inflammation triggered aversion through MyD88-dependent activation of the brain endothelium followed by COX1-mediated cerebral prostaglandin E-2 (PGE(2)) synthesis. Further, we showed that inflammation-induced PGE(2) targeted EP1 receptors on striatal dopamine D1 receptor-expressing neurons and that this signaling sequence induced aversion through GABA-mediated inhibition of dopaminergic cells. Finally, we demonstrated that inflammation-induced aversion was not an indirect consequence of fever or anorexia but that it constituted an independent inflammatory symptom triggered by a unique molecular mechanism. Collectively, these findings demonstrate that PGE(2)-mediated modulation of the dopaminergic motivational circuitry is a key mechanism underlying the negative affect induced by inflammation.
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| 39. |
- Gerhardsson, Emma, et al.
(författare)
-
Developing the preterm breastfeeding attitudes instrument : A tool for describing attitudes to breastfeeding among health care professionals in neonatal intensive care
- 2021
-
Ingår i: Midwifery. - : Elsevier BV. - 0266-6138 .- 1532-3099. ; 94
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to develop an instrument that measures health care professionals' (HCPs) attitudes to breastfeeding and skin-to-skin contact in relation to the Baby-Friendly Hospital Initiative for neonatal intensive care.DESIGN: The study was part of a larger project aiming to revive the Ten Steps to Successful Breastfeeding for both full-term and preterm infants. The study had a pre-test/post-test design using online questionnaires distributed by email before and after a training programme.SETTING AND PARTICIPANTS: A total of 70 specialist registered nurses, registered nurses, assistant nurses and physicians working at a Swedish neonatal intensive care unit answered 55 breastfeeding attitudes questions online before the training. The Preterm Breastfeeding Attitudes Instrument (PreBAI) consists of twelve of these 55 items/questions, selected using exploratory factor analysis.MEASUREMENTS AND FINDINGS: Higher scores indicated more positive attitudes and the median total PreBAI score was 42 points (out of 48), on both the pre- and the post-test questionnaires, showing no significant difference. In the pre-test questionnaire, the majority of HCPs (84%) stated that they needed further breastfeeding training. They also stated that they perceived breastfeeding as very important, scoring a median of 10 (range 5-10) points on a 10-point scale. Three separate underlying dimensions were identified in the questionnaire, indicating different attitudes: Facilitating (five items), Regulating (four items), and Breastfeeding- and skin-to-skin contact-friendly (three items). A positive correlation was found between how many years the HCPs had worked in neonatal care, and their PreBAI score (rs = 0.383, p = 0.001). Those who had previously received extra breastfeeding education scored higher on the instrument.KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Neonatal intensive care units need to increase their efforts to support breastfeeding. An important factor for mothers when establishing breastfeeding is support from well-trained professionals with a positive attitude to breastfeeding. The PreBAI could be a useful tool for identifying attitudes among HCPs before and after attending a breastfeeding training programme.
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| 40. |
- Gustafsson, Mats, et al.
(författare)
-
Factors influencing PM10 emissions from road pavement wear
- 2009
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 43:31, s. 4699-4702
-
Konferensbidrag (refereegranskat)abstract
- Accelerated pavement wear is one of the major environmental disadvantages of studded tyres in northern regions and results in increased levels of PM10. Measurements of PM10 in a road simulator hall have been used to study the influence of pavement properties, tyre type and vehicle speed on pavement wear. The test set-up included three different pavements (one granite and two quartzite with different aggregate sizes), three different tyre types (studded, non-studded, and summer tyres) and different speeds (30-70 km h(-1)). The results show that the granite pavement was more prone to PM10 production compared to the quartzite pavements. Studded winter tyres yield tens of times higher PM10 concentrations compared to non-studded winter tyres. Wear from summer tyres was negligible in comparison. It was also shown that wear is strongly dependent on speed; every 10 km h(-1) increase yielded an increase of the PM10 concentration of 680 mu g m(-3) in one of the simulator experiments. (C) 2008 Elsevier Ltd. All rights reserved.
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| 41. |
- Gustafsson, Mats, et al.
(författare)
-
Inandningsbara partiklar från dubbdäcksslitage av vägbana : egenskaper och inflammatoriska effekter i mänskliga luftvägsceller. utdrag ur WearTox-projektet (VTI rapport 520)
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aims of this project have been to describe PM10 from studded tyre wear and to study their inflammatory effects in human airway cells. The VTI circular road simulator has been used to generate "clean" wear particles from two different pavements; asphalt concrete (ABT) and stone mastic asphalt (ABS), with granite respectively quartzite as the main stone materials. The advantage of using the road simulator is that the contribution from other sources can be minimised. During the project time, the project was expanded also to study particle generation by non-studded winter tyres (friction tyres) and two kinds of winter sanding agents, namely washed crushed stone and unwashed natural sand in combination with both studded and friction tyres. Most of these parts of the project are presented in VTI report 520. The results show that pavement wear by studded tyres generates about 40-50 times as much PM10 as that by friction tyres, but also that the ABT pavement generates several times more PM10 than the ABS pavement. The size distribution within PM10 has a maximum around 3-4 ?m and more than 95 % of the mass is larger than 1 ?m. PM10 is totally dominated by fresh stone material. A fraction of very small particles, with a number concentration peak at around 30-40 nm, was also discovered. Their origin is unknown, but since the number distribution shifted depending on which tyre type was used, a possible origin is the tyres. In the cell studies the inflammation potential of the wear particles was compared with PM10 from Hornsgatan in Stockholm and PM10 from a Stockholm subway station. Later on in the project, diesel particles were made available for comparison. The cell study results show that PM10 from the ABT pavement is at least as inflammatory as diesel particles and more inflammatory than PM10 from the subway. The PM10 from Hornsgatan generally had the highest potential, but PM10 from the ABT pavement was often in parity. This despite the fact that the Hornsgatan PM10 were the only particle sample where endotoxin could be detected. Endotoxin causes an additive effect in studies of inflammation potential. PM10 from the ABS pavement generally had a lower potential than PM10 from the ABT pavement.
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| 42. |
|
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| 43. |
- Gustafsson, Mats, et al.
(författare)
-
Inandningsbara partiklar från interaktion mellan däck, vägbana och friktionsmaterial : slutrapport av WearTox-projektet
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aims of this project have been to describe PM10 from studded tyre wear and to study their inflammatory effects in human airway cells. The VTI circular road simulator has been used to generate "clean" wear particles from two different pavements; asphalt concrete (ABT) and stone mastic asphalt (ABS), with granite respectively quartzite as the main stone materials. The advantage of using the road simulator is that the contribution from other sources can be minimised. During the project time, the project was expanded also to study particle generation by non-studded winter tyres (friction tyres) and two kinds of winter sanding agents, namely washed crushed stone and unwashed natural sand in combination with both studded and friction tyres. The results show that pavement wear by studded tyres generates about 40-50 times as much PM10 as that by friction tyres, but also that the ABT pavement generates several times more PM10 than the ABS pavement. The size distribution within PM10 has a maximum around 3-4 ?m and more than 95 % of the mass is larger than 1 ?m. PM10 is totally dominated by fresh stone material. A fraction of very small particles, with a number concentration peak at around 30-40 nm, was also discovered. Their origin is unknown, but since the number distribution shifted depending on which tyre type was used, a possible origin is the tyres. In the experiments using sanding material, the unwashed natural sand caused the highest PM10 concentrations. Friction tyres on natural sand caused higher concentrations than studded tyres on washed crushed stone. Studded tyres generated more PM10 than friction tyres but the difference was not as large as when no sanding material was used. In the cell studies the inflammation potential of the wear particles was compared with PM10 from Hornsgatan in Stockholm and PM10 from a Stockholm subway station. Later on in the project, diesel particles were made available for comparison. The cell study results show that PM10 from the ABT pavement is at least as inflammatory as diesel particles and more inflammatory than PM10 from the subway. The PM10 from Hornsgatan generally had the highest potential, but PM10 from the ABT pavement was often in parity. This despite the fact that the Hornsgatan PM10 were the only particle sample where endotoxin could be detected. Endotoxin causes an additive effect in studies of inflammation potential. PM10 from the ABS pavement generally had a lower potential than PM10 from the ABT pavement.
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| 44. |
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| 45. |
- Gustafsson, Mats, et al.
(författare)
-
Inandningsbara partiklar i järnvägsmiljöer
- 2006
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Airborne particles from railroad traffic have been identified as an air pollution problem mainly in tunnel environments. As a result of the introduction of the environmental quality standard for inhalable particles in Sweden 2005, the interest in railroad particle pollution has increased. The present report focuses on the variation of PM10 (inhalable particles) in some railroad environments under and above ground, the way these relate to traffic and on the particles' size distributions and elemental composition. The results show that particle concentrations in above ground railroad environments do not exceed the environmental quality standard during the campaigns. Diurnal mean values of PM10 range between 19 to 25 microg/m3. On the contrary, the diurnal mean concentrations on the platforms of the underground stations Arlanda Central and Arlanda South are far above the limit value (237 and 88 microg/m3 respectively) and clear diurnal and weekly patterns in PM10 concentration, co-fluctuating with traffic, can be identified. The particle mass size distribution has an obvious peak around 5-7 ?m at Arlanda C, and slightly smaller, 2-3 microm, at Arlanda S. The concentrations of both PM10 and ultrafine particles (< 0,1 microm) vary a lot depending on different trains. Especially the ultrafine particles seem to be emitted from certain trains, but it has not been possible to identify the source of these particles. The elemental composition of the particles in the tunnel environments was dominated by iron (84 % and 74 % respectively in Arlanda C and Arlanda S), but also other metals, like Cu, Zn, Cr, Ni and Sb (only at Arlanda C) have relatively high concentrations. The tunnel measurements also give some interesting results regarding possible measures against high particle concentrations. Washing of the tunnel walls and floor was carried out on two consecutive nights, but it had no noticeable results on particle concentrations. This implies that a dominant proportion of the particles is directly emitted rather than resuspended. On certain nights, the concentrations of all particle size fractions sank to very low levels, lasting till the morning traffic began. This implies effective self ventilation during these hours. Measurements in several different environments on Stockholm central station show that PM10 vary several tens of microg/m3. Activity, related to both traffic and people, increases particle concentration. The highest concentrations were measured inside the waiting hall. Nevertheless, the concentrations on the platforms were generally at least as high as in the busy street environment outside the station. During a railroad travel, the PM10 and PM2,5 concentrations were generally low, but increase at stops and, most prominently, on entering the Arlanda airport railroad tunnels. The PM2,5 proportion is considered high, contributing to approximately 50-80 % of PM10. The sources of railroad emitted PM10 are likely to be rails, wheels and brakes, but a source apportionment has not been accomplished in this project.
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| 46. |
- Gustafsson, Mats, et al.
(författare)
-
Inhalable railroad particles at ground level and subterranean stations : physical and chemical properties and relation to train traffic
- 2012
-
Ingår i: Transportation Research Part D. - Amsterdam : Elsevier. - 1361-9209 .- 1879-2340. ; 17:3, s. 277-285
-
Tidskriftsartikel (refereegranskat)abstract
- The paper compares PM10 concentrations in railroad environments with EU air quality standards and characterizes particle concentrations and particle properties in relation to train traffic. The results show that PM10 concentrations in ground-level railroad environments do not exceed the EU directive 24-h limit value, while on the platforms of the two subterranean stations PM10 concentrations were far above the outdoor limit value. Diurnal and weekly patterns in PM10 concentration could be identified, co-varying with train traffic intensity. The particle mass size distribution peaked at around 2–micro-m. The elemental composition of PM10 at the subterranean stations was dominated by Fe.
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| 47. |
- Gustafsson, Mats, et al.
(författare)
-
NanoWear : nanopartiklar från slitage av däck och vägbana
- 2009
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Particles from road and tire wear have in recent years come to the fore as an important and relatively unexplored contribution to air particulate pollution. Mechanically generated wear particles are relatively coarse (>0.5 microns), but in controlled trials in VTI's road simulator it has been found that an ultra-fine fraction (< 100 nm) of particles is formed from tyre and pavement wear. This project was initiated to identify the source of these nanoparticles. The results show that the nanoparticles of the size 30-50 nm occur only from tests with studded tyres. One of the two tested Nordic unstudded winter tyres produced an even finer particle fraction (<10 nm), while the other unstudded winter tyre type did not give rise to nanoparticles. Tests with summer tyres did not result in the formation of nanoparticles. It is clear that the fine particle fraction contains higher relative concentrations of sulphur, which is present at relatively high levels in both bitumen and tyres. It is unclear whether the ultrafine particles formed from studded tyre wear of road pavement in the road simulator also occur in real traffic. If so, this may affect the assessment of health effects from different traffic related particle sources.
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| 48. |
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| 49. |
- Gustafsson, Mats, et al.
(författare)
-
Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material
- 2008
-
Ingår i: Science of the Total Environment. - : Institutionen för klinisk och experimentell medicin. - 0048-9697 .- 1879-1026. ; 393:2-3, s. 226-240
-
Tidskriftsartikel (refereegranskat)abstract
- In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic is the main reason for high particle concentrations in busy street- and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM10) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, PIXE and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM10, respectively. The results show that in the road simulator, where resuspension is minimised, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consists almost entirely of minerals from the pavement stone material, but also that S is enriched for the sub-micron particles and that Zn is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results implies that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.
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| 50. |
- Gustafsson, Mats, et al.
(författare)
-
Studies of wear particles using the VTI road simulator/particle generator
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The high costs of maintenance related to pavement wear have caused many countries to prohibit the use of studded tyres. In Japan and Norway, regulations have also been based upon the health aspects of the road dust. In Japan studded tyres are prohibited and in Norway, restrictions have been placed on the use of studded tyres in some larger cities. In Sweden, wear particles from pavements, tyres, brakes and winter sanding/salting, have received a lot of attention the last few years. The reason for this is that measurements have shown that these particles are the main reason that the upcoming environmental quality standard for inhalable particles (PM10) will not be reached in many cities. The problem mainly occurs during dry episodes in winter and early spring and is mainly a result of studded tyre use and winter maintenance. A lot of new knowledge about wear particles is needed in order to develop cost-effective measures to deal with them. A great advantage is the possibility to study aerosols from each source both separately and in different combinations in a controlled environment. At VTI (Swedish National Road and Transport Research Institute) a road simulator (PVM), previously used for pavement and tyre wear studies, is used as a wear particle generator. The PVM can be equipped with different pavements and tyres and even friction materials such as sand can be applied. The PVM can be used at speeds up to 70 km/h and the pavement can be dry or wet. Also the temperature in the hall can be regulated below zero degrees centigrade. In this paper some results from the WearTox project will be presented. The production of PM10 from two pavements worn by studded tyres and friction tyres has been studied as well as the physical and chemical properties of the wear particles produced.
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