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| 2. |
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| 3. |
- Annamalai, Alagappan, et al.
(författare)
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Influence of Sb5+ as a Double Donor on Hematite (Fe3+) Photoanodes for Surface-Enhanced Photoelectrochemical Water Oxidation
- 2018
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 10:19, s. 16467-16473
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Tidskriftsartikel (refereegranskat)abstract
- To exploit the full potential of hematite (α-Fe2O3) as an efficient photoanode for water oxidation, the redox processes occurring at the Fe2O3/electrolyte interface need to be studied in greater detail. Ex situ doping is an excellent technique to introduce dopants onto the photoanode surface and to modify the photoanode/electrolyte interface. In this context, we selected antimony (Sb5+) as the ex situ dopant because it is an effective electron donor and reduces recombination effects and concurrently utilize the possibility to tuning the surface charge and wettability. In the presence of Sb5+ states in Sb-doped Fe2O3 photoanodes, as confirmed by X-ray photoelectron spectroscopy, we observed a 10-fold increase in carrier concentration (1.1 × 1020 vs 1.3 × 1019 cm–3) and decreased photoanode/electrolyte charge transfer resistance (∼990 vs ∼3700 Ω). Furthermore, a broad range of surface characterization techniques such as Fourier-transform infrared spectroscopy, ζ-potential, and contact angle measurements reveal that changes in the surface hydroxyl groups following the ex situ doping also have an effect on the water splitting capability. Theoretical calculations suggest that Sb5+ can activate multiple Fe3+ ions simultaneously, in addition to increasing the surface charge and enhancing the electron/hole transport properties. To a greater extent, the Sb5+- surface-doped determines the interfacial properties of electrochemical charge transfer, leading to an efficient water oxidation mechanism.
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| 5. |
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| 6. |
- Ekspong, Joakim, et al.
(författare)
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Stable Sulfur‐Intercalated 1T′ MoS2 on Graphitic Nanoribbons as Hydrogen Evolution Electrocatalyst
- 2018
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Ingår i: Advanced Functional Materials. - : WILEY-VCH VERLAG GMBH. - 1616-301X .- 1616-3028. ; 28:46
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Tidskriftsartikel (refereegranskat)abstract
- The metastable 1T′ polymorph of molybdenum disulfide (MoS2) has shown excellent catalytic activity toward the hydrogen evolution reaction (HER) in water‐splitting applications. Its basal plane exhibits high catalytic activity comparable to the edges in 2H MoS2 and noble metal platinum. However, the production and application of this polymorph are limited by its lower energetic stability compared to the semiconducting 2H MoS2 phase. Here, the production of stable intercalated 1T′ MoS2 nanosheets attached on graphitic nanoribbons is reported. The intercalated 1T′ MoS2 exhibits a stoichiometric S:Mo ratio of 2.3 (±0.1):1 with an expanded interlayer distance of 10 Å caused by a sulfur‐rich intercalation agent and is stable at room temperature for several months even after drying. The composition, structure, and catalytic activity toward HER are investigated both experimentally and theoretically. It is concluded that the 1T′ MoS2 phase is stabilized by the intercalated agents, which further improves the basal planes′ catalytic activity toward HER.
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| 7. |
- Geissinger, Andrea, 1987-
(författare)
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Platforms in Liquid Modernity : Essays about the Sharing Economy, Digital Platforms, and Institutions
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The year 2020 feels like the beginning of a crescendo of change. As environmental and social challenges reach an all-time high, the organization of our societies is coming under scrutiny. We, as a society, turn to technology to reinvent the organization of social life after disruptive episodes. Inspired by Bauman's theorizing to describe the cultural and societal zeitgeist, this thesis explains the institutionalization of one of the most promising alternative forms of organization of the past decade: the sharing economy.Comprised of nine essays centered around three focal areas: (1) Organizational change, (2) Market change, and (3) Societal change, this thesis aims to explain the institutionalization of digital sharing platforms in liquid modern society.This thesis finds that digital sharing platforms act as societal organizers on several dimensions of “in-betweenness.” As this moment in time can also be characterized as a period of “interregnum”—another moment of in-betweenness—where old structures are continuously disrupted but no clear new path has emerged, digital platform providers fill a structural void in our highly individualized society. Digital platform providers use community as an anchor, a belief, and sets of practices to create an emerging (intermediary) institution around which different forms of organization manifest.Digital sharing platforms have, however, remained a grace note on systemic change: ornamental and practically non-essential. Still, digital platforms are setting new norms in all areas of organizational, market, and societal life. By evoking both elements of community and market, digital platforms are playing an important part in creating a symphony of our future societal order.
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| 8. |
- Gustafsson, Robin, et al.
(författare)
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Towards an Integrative Digital History Approach in Organization Studies
- 2016
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Ingår i: Academy of Management Proceedings. - : Academy of Management.
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Konferensbidrag (refereegranskat)abstract
- Recent developments in digitizing of historical data and advances in software tools for structured analysis of digitized historical data, are creating opportunities to unleash previously untapped ways to use historical data. We build on recent suggestions for methodological integration, for outlining an integrative digital history approach, with the methodological rigor to unleash creative synthesis of business history and organization studies. Methodological integration constitutes an inter-meshing of methods that takes place already from the outset of the research process and remains so throughout the collection of sources, interpretation, and analysis. This places at the center a careful research design with a relational database for the collection and digitizing of data, structuring and coding of historical sources, historical interpretation, and analytics to be used. We outline key design issues, steps and processes for an integrative digital history approach. Following, we present the strengths of this approach in comparison to existing ‘analog’ business history and organizational studies methods. We end the paper by discussing future avenues and opportunities for digital history.
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| 9. |
- Hu, Guangzhi, et al.
(författare)
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Atomistic understanding of the origin of high oxygen reduction electrocatalytic activity of cuboctahedral Pt3Co-Pt core-shell nanoparticles
- 2016
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Ingår i: Catalysis Science & Technology. - : Royal Society of Chemistry (RSC). - 2044-4753 .- 2044-4761. ; 6:5, s. 1393-1401
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Tidskriftsartikel (refereegranskat)abstract
- PtM-based core-shell nanoparticles are a new class of active and stable nanocatalysts for promoting oxygen reduction reaction (ORR); however, the understanding of their high electrocatalytic performance for ORR at the atomistic level is still a great challenge. Herein, we report the synthesis of highly ordered and homogeneous truncated cuboctahedral Pt3Co-Pt core-shell nanoparticles (cs-Pt3Co). By combining atomic resolution electron microscopy, X-ray photoelectron spectroscopy, extensive first-principles calculations, and many other characterization techniques, we conclude that the cs-Pt3Co nanoparticles are composed of a complete or nearly complete Pt monolayer skin, followed by a secondary shell containing 5-6 layers with similar to 78 at% of Pt, in a Pt3Co configuration, and finally a Co-rich core with 64 at% of Pt. Only this particular structure is consistent with the very high electrocatalytic activity of cs-Pt3Co nanoparticles for ORR, which is about 6 times higher than commercial 30%-Pt/Vulcan and 5 times more active than non-faceted (spherical) alloy Pt3Co nanoparticles. Our study gives an important insight into the atomistic design and understanding of advanced bimetallic nanoparticles for ORR catalysis and other important industrial catalytic applications.
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| 10. |
- Hunter, Amanda, et al.
(författare)
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Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters
- 2014
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Ingår i: Particle and Fibre Toxicology. - : BioMed Central (BMC). - 1743-8977. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Myocardial infarction is the leading cause of death in fire fighters and has been linked with exposure to air pollution and fire suppression duties. We therefore investigated the effects of wood smoke exposure on vascular vasomotor and fibrinolytic function, and thrombus formation in healthy fire fighters. Methods: In a double-blind randomized cross-over study, 16 healthy male fire fighters were exposed to wood smoke (~1 mg/m3 particulate matter concentration) or filtered air for one hour during intermittent exercise. Arterial pressure and stiffness were measured before and immediately after exposure, and forearm blood flow was measured during intra-brachial infusion of endothelium-dependent and -independent vasodilators 4–6 hours after exposure. Thrombus formation was assessed using the ex vivo Badimon chamber at 2 hours, and platelet activation was measured using flow cytometry for up to 24 hours after the exposure. Results: Compared to filtered air, exposure to wood smoke increased blood carboxyhaemoglobin concentrations (1.3% versus 0.8%; P < 0.001), but had no effect on arterial pressure, augmentation index or pulse wave velocity (P > 0.05 for all). Whilst there was a dose-dependent increase in forearm blood flow with each vasodilator (P < 0.01 for all), there were no differences in blood flow responses to acetylcholine, sodium nitroprusside or verapamil between exposures (P > 0.05 for all). Following exposure to wood smoke, vasodilatation to bradykinin increased (P = 0.003), but there was no effect on bradykinin-induced tissue-plasminogen activator release, thrombus area or markers of platelet activation (P > 0.05 for all). Conclusions: Wood smoke exposure does not impair vascular vasomotor or fibrinolytic function, or increase thrombus formation in fire fighters. Acute cardiovascular events following fire suppression may be precipitated by exposure to other air pollutants or through other mechanisms, such as strenuous physical exertion and dehydration.
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| 11. |
- Kwong, Wai Ling, et al.
(författare)
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Cationic Vacancy Defects in Iron Phosphide : A Promising Route toward Efficient and Stable Hydrogen Evolution by Electrochemical Water Splitting
- 2017
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Ingår i: ChemSusChem. - : Wiley-Blackwell. - 1864-5631 .- 1864-564X. ; 10:22, s. 4544-4551
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Tidskriftsartikel (refereegranskat)abstract
- Engineering the electronic properties of transition metal phosphides has shown great effectiveness in improving their intrinsic catalytic activity for the hydrogen evolution reaction (HER) in water splitting applications. Herein, we report for the first time, the creation of Fe vacancies as an approach to modulate the electronic structure of iron phosphide (FeP). The Fe vacancies were produced by chemical leaching of Mg that was introduced into FeP as "sacrificial dopant". The obtained Fe-vacancy-rich FeP nanoparticulate films, which were deposited on Ti foil, show excellent HER activity compared to pristine FeP and Mg-doped FeP, achieving a current density of 10 mAcm(-2) at overpotentials of 108 mV in 1 m KOH and 65 mV in 0.5 m H2SO4, with a near-100% Faradaic efficiency. Our theoretical and experimental analyses reveal that the improved HER activity originates from the presence of Fe vacancies, which lead to a synergistic modulation of the structural and electronic properties that result in a near-optimal hydrogen adsorption free energy and enhanced proton trapping. The success in catalytic improvement through the introduction of cationic vacancy defects has not only demonstrated the potential of Fe-vacancy-rich FeP as highly efficient, earth abundant HER catalyst, but also opens up an exciting pathway for activating other promising catalysts for electrochemical water splitting.
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| 12. |
- Lindblom, Anna, et al.
(författare)
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Interspecies plasmid transfer appears rare in sequential infections with extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae
- 2019
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Ingår i: Diagnostic Microbiology and Infectious Disease. - : Elsevier BV. - 0732-8893 .- 1879-0070. ; 93:4, s. 380-385
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Tidskriftsartikel (refereegranskat)abstract
- From a cohort of 1836 Swedish patients infected with ESBL-producing Enterobacteriaceae (EPE) during 2004-2014, 513 patients with recurrent EPE infection were identified. Only in 14 of the 513 patients was a change of species (ESBL-E. coli to ESBL-K. pneumoniae or vice versa) found between the index and subsequent infection. Eleven sequential urine isolates from 5 of the 14 patients were available for further analysis of possible transfer of ESBL-carrying plasmids. The plasmid content was studied using optical DNA mapping (ODM), PCR-based replicon typing, and ESBL gene sequencing. ODM allowed us to directly compare whole plasmids between isolates and found similar ESBL-carrying plasmids in 3 out of the 5 patients. The ODM results and the rarity in shift of species between ESBL-E. coli and ESBL-K. pneumoniae imply that in recurrent EPE infections interspecies plasmid transfer is uncommon. (C) 2018 Elsevier Inc. All rights reserved.
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| 13. |
- Muala, Ala, et al.
(författare)
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Acute exposure to wood smoke from incomplete combustion - indications of cytotoxicity
- 2015
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Ingår i: Particle and Fibre Toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Smoke from combustion of biomass fuels is a major risk factor for respiratory disease, but the underlying mechanisms are poorly understood. The aim of this study was to determine whether exposure to wood smoke from incomplete combustion would elicit airway inflammation in humans. Methods: Fourteen healthy subjects underwent controlled exposures on two separate occasions to filtered air and wood smoke from incomplete combustion with PM1 concentration at 314 mu g/m(3) for 3 h in a chamber. Bronchoscopy with bronchial wash (BW), bronchoalveolar lavage (BAL) and endobronchial mucosal biopsies was performed after 24 h. Differential cell counts and soluble components were analyzed, with biopsies stained for inflammatory markers using immunohistochemistry. In parallel experiments, the toxicity of the particulate matter (PM) generated during the chamber exposures was investigated in vitro using the RAW264.7 macrophage cell line. Results: Significant reductions in macrophage, neutrophil and lymphocyte numbers were observed in BW (p < 0.01, < 0.05, < 0.05, respectively) following the wood smoke exposure, with a reduction in lymphocytes numbers in BAL fluid (< 0.01. This unexpected cellular response was accompanied by decreased levels of sICAM-1, MPO and MMP-9 (p < 0.05, < 0.05 and < 0.01). In contrast, significant increases in submucosal and epithelial CD3+ cells, epithelial CD8+ cells and submucosal mast cells (p < 0.01, < 0.05, < 0.05 and < 0.05, respectively), were observed after wood smoke exposure. The in vitro data demonstrated that wood smoke particles generated under these incomplete combustion conditions induced cell death and DNA damage, with only minor inflammatory responses. Conclusions: Short-term exposure to sooty PAH rich wood smoke did not induce an acute neutrophilic inflammation, a classic hallmark of air pollution exposure in humans. While minor proinflammatory lymphocytic and mast cells effects were observed in the bronchial biopsies, significant reductions in BW and BAL cells and soluble components were noted. This unexpected observation, combined with the in vitro data, suggests that wood smoke particles from incomplete combustion could be potentially cytotoxic. Additional research is required to establish the mechanism of this dramatic reduction in airway leukocytes and to clarify how this acute response contributes to the adverse health effects attributed to wood smoke exposure.
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| 14. |
- Muala, Ala, et al.
(författare)
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Bronchial mucosal inflammation in healthy subjects after exposure to wood smoke from incomplete combustion
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Indoor smoke from combustion of solid biomass fuel is a major risk factor for respiratory disease worldwide. The mechanisms by which wood smoke exhibits its effects on human health are not well understood. The aim of this study was to determine whether exposure to wood smoke produced from incomplete combustion would elicit an airway inflammatory response.Methods Fourteen healthy subjects underwent controlled chamber exposure on two occasions to filtered air and to sooty wood smoke (PM1 ~ 314 μg/m3), generated by a common Nordic wood stove firing birch logs. The study was performed with a double-blind randomized cross-over design and the subjects alternated between exercise (VE=20 L/min/m2) and rest at 15-minute intervals for 3 hours. Bronchoscopies were performed 24 hours after each exposure where bronchial wash (BW), bronchoalveolar lavage (BAL) and endobronchial biopsies were taken. Differential cell counts and soluble components were analyzed in BW and BAL. Bronchial mucosal biopsies were analyzed using immunohistochemistry. Blood tests for inflammatory markers were sampled pre-exposure as well as at 24 and 44-hour time points post-exposure. Spirometry and Fraction of exhaled nitric oxide (FENO) were performed before, immediately after and 24 hours after each exposure.Results There was a significant increase in submucosal and epithelial CD3+ lymphocytes (p<0.01 and <0.05 respectively), together with CD8+ cells in the epithelium (p<0.05) after exposure to wood smoke compared to filtered air. Mast cells were also significantly increased in the submucosa (p<0.01) after wood smoke exposure.There were significant reductions in macrophages, neutrophils and lymphocytes in BW after exposure to wood smoke compared to filtered air, accompanied by decreased levels of soluble Intercellular Adhesion Molecule-1 (sICAM-1), myeloperoxidase (MPO) and matrix metalloproteinase-9 (MMP-9). No significant effects on cell numbers or acute inflammatory markers were demonstrated in BAL fluid or peripheral blood. Lung function and FENO were not affected by exposure to wood smoke.Conclusions Wood smoke exposure caused a significant increase in bronchial epithelial and submucosal CD3+ lymphocytes together with an increase in mucosal mast cells. Further examination revealed a significant increase in CD8+ lymphocytes within the epithelium. Unexpectedly there were no indications of any neutrophilic airway response or recruitment of alveolar macrophages. BW cell numbers, MPO and MMP-9 levels were also significantly reduced after wood smoke exposure. Further research is needed to determine the precise role of these events in relationship to the adverse health effects attributed to wood smoke exposure.
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| 15. |
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| 16. |
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| 17. |
- Muala, Ala, et al.
(författare)
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Respiratory Tract Deposition of Inhaled Wood Smoke Particles in Healthy Volunteers
- 2015
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Ingår i: Journal of Aerosol Medicine. - : Mary Ann Liebert Inc. - 1941-2711 .- 1941-2703. ; 28:4, s. 237-246
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Tidskriftsartikel (refereegranskat)abstract
- Background: Respiratory tract deposition of air pollution particles is a key to their adverse health effects. This study was aimed to determine the size-resolved deposition fraction (DF) of sooty wood smoke particles in the lungs of healthy subjects. The type of wood smoke investigated is typical for household air pollution from solid fuels, which is among the largest environmental health problems globally.Methods: Twelve healthy volunteers inhaled diluted wood smoke from incomplete soot-rich combustion in a common wood stove. The DF of smoke particles (10–500 nm) was measured during three 15-min exposures in each subject during spontaneous breathing. Lung function was measured using standard spirometry.Results: The total DFs by particle number concentration were 0.34±0.08. This can be compared with DFs of 0.21–0.23 in healthy subjects during previous experiments with wood pellet combustion. For particle mass, the total DFs found in this study were 0.22±0.06. DF and breathing frequency were negatively correlated as expected from model calculations (p<0.01).Conclusions: The DF of the investigated sooty wood smoke particles was higher than for previously investigated particles generated during more efficient combustion of biomass. Together with toxicological studies, which have indicated that incomplete biomass combustion particles rich in soot and polycyclic aromatic hydrocarbons (PAHs) are especially harmful, these data highlight the health risks of inadequate wood combustion.
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| 18. |
- Ngoc Pham, Tung, et al.
(författare)
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Robust hierarchical 3D carbon foam electrode for efficient water electrolysis
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Herein we report a 3D heterostructure comprising a hierarchical macroporous carbon foam that incorporates mesoporous carbon nanotubes decorated with cobalt oxide nanoparticles as an unique and highly efficient electrode material for the oxygen evolution reaction (OER) in electrocatalytic water splitting. The best performing electrode material showed high stability after 10 h, at constant potential of 1.7 V vs. RHE (reversible hydrogen electrode) in a 0.1 M KOH solution and high electrocatalytic activity in OER with low overpotential (0.38 V vs RHE at 10 mA cm(-2)). The excellent electrocatalytic performance of the electrode is rationalized by the overall 3D macroporous structure and with the firmly integrated CNTs directly grown on the foam, resulting in a large specific surface area, good electrical conductivity, as well as an efficient electrolyte transport into the whole electrode matrix concurrent with an ability to quickly dispose oxygen bubbles into the electrolyte. The eminent properties of the three-dimensional structured carbon matrix, which can be synthesized through a simple, scalable and cost effective pyrolysis process show that it has potential to be implemented in large-scale water electrolysis systems.
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| 19. |
- Nitze, Florian, 1981, et al.
(författare)
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Direct support mixture painting, using Pd(0) organo-metallic compounds - an easy and environmentally sound approach to combine decoration and electrode preparation for fuel cells
- 2014
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 2:48, s. 20973-20979
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Tidskriftsartikel (refereegranskat)abstract
- An inventive, fast and straight-forward approach for the direct preparation of fuel cell electrodes has been developed and tested. Our approach avoids long catalyst preparation and post-synthesis treatment. It reduces the use of chemicals and thereby concomitantly lowers the environmental impact and improves cost efficiency. It combines decoration of the support by palladium nanoparticles with electrode preparation through a simple one-step ink-painting and annealing process. Composites have been investigated by high resolution transmission electron microscopy, scanning electron microscopy, and Xray diffraction. Crystalline particles are well-attached and well-distributed on the support. Particles are of few nanometers in size and spherical for decorated Vulcan whereas they are larger and irregularly shaped for decorated helical carbon nanofibers (HCNFs). Electrodes with a metal loading of 0.8 mg cm(-2) have been tested in a direct formic acid fuel cell. Both the Vulcan and the HCNF electrodes show a similar and high power output of up to 120 mW mg(-1). They also show similar performances in deactivation experiments conducted at 200 mA cm(-2) even when using only high purity grade formic acid. After deactivation the electrodes show no structural damage, making them superior to most commercial catalysts. The electrodes can be completely regenerated to initial activity by simple treatment with water. The easy regeneration process indicates that CO-adsorption on the fuel cell anode catalyst is not the main poisoning mechanism responsible for electrode degeneration.
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| 20. |
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| 21. |
- Nyström, Robin, 1985-, et al.
(författare)
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Effects of dilution conditions on particle formation and size distribution in engine exhaust emissions when introducing biodiesel in comparison to standard petro diesel
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Air pollution, in particular ambient particulate matter (PM), can be linked to a variety of different health effects, and a major contributor to the PM pollution is exhaust from diesel engines and other vehicles. In the global drive towards finding sustainable and clean bio-based alternative fuels for the transport sector, biodiesel is one of the most established alternative. However, there is considerable variation in emission data for biodiesel, preferably explained by influences of engine technology and operating conditions as well as dilution sampling strategy. In this study the focus was therefore to study the effects of dilution conditions on the particle formation and size distribution in the exhaust emissions from an off road engine, when introducing RME biodiesel in comparison to standard petro diesel. Particle size distribution and number concentration were measured on-line with the use of a fast mobility spectrometer, during a transient operation and without engine modification. Differences in particle characteristics were elucidated in the raw exhaust versus diluted exhaust at two subsequent sampling points with different dilution ratios. In addition, the influences on the exhaust particle properties of changing the lubrication oil was investigated. It was found that biodiesel in general generated more nucleation mode particles then petro diesel, and after the oil exchange the total particle number concentration was increased even more. It was also seen that the custom-built dilution setup favors generation of nucleation mode particles, which is in line with real life conditions in chase and road side experiments. However, when using heated primary dilution and a heated line in the raw exhaust the formation of nucleation mode particles was suppressed. Overall, it was concluded that the introduction of the biodiesel, and potentially other renewable fuels, can in a considerable way change the exhaust particle emission and characteristics. This could have implications for the assessment of exhaust from engines running on biodiesel fuels, especially when introducing biodiesel in existing and older engines.
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| 22. |
- Nyström, Robin, 1985-, et al.
(författare)
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Evaluation of a novel chamber setup for human exposures of biomass combustion aerosols
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Based on a vast number of epidemiological studies there is today a consensus that increased concentrations of ambient particulate matter air pollution cause adverse health effects such as mortality, hospitalizations, cardiovascular events, respiratory symptoms and reduced lung function. The use of controlled laboratory studies with human exposure chambers can give unique opportunities to directly examine specific exposure conditions and cause-effect relationship with relevant concentrations and particle types. In this paper, the design of a novel chamber setup for human exposures of biomass combustion aerosols is described with an evaluation of the systems function under different conditions (e.g. air exchange rates and target PM1 concentrations). Several different research biomass combustion systems are available in combination with extensive and advanced monitoring and characterization of the gaseous and particle emissions used for exposures. Examples, with data from three performed human exposure campaigns, are included and discussed as a basis for the evaluation of the whole setup, with the target to generate stable conditions in the chamber using different kinds of biomass combustion aerosols. Based on the evaluation of function and present exposure experiences it can be concluded that the chamber setup and biomass aerosol generation systems is able to produce a stable aerosol concentration in the chamber of different particle types. Overall, the human exposure setup for biomass combustion aerosols together with the integrated biomass combustion laboratory gives extensive possibilities for designing different whole body human exposure studies for a variety of biomass combustion aerosols as well as other experimental aerosol research.
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| 23. |
- Nyström, Robin, 1985-, et al.
(författare)
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Physical and chemical properties of RME biodiesel exhaust particles without engine modifications
- 2016
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 186, s. 261-269
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Tidskriftsartikel (refereegranskat)abstract
- A major contributor to ambient particulate air pollution is exhaust from diesel engines and other vehicles,which can be linked to different adverse health effects. During the last decades, a global drive towardsfinding sustainable and clean bio-based alternative fuels for the transport sector has taken place and biodieselis one of the most established alternatives today. To better assess the overall effects on a publichealth level when introducing biodiesel and other renewable fuels, a better understanding of the detailedexhaust particle properties, is needed. In this work, the physical and chemical properties of biodieselexhaust particles were studied in comparison to standard diesel exhaust emissions, in an existing enginewithout modifications, focusing on particulate carbonaceous matter and PAH/Oxy-PAH as well as fineparticle size distribution. An older off-road engine, produced between 1996 and 2004, was used withthree different fuels/fuel blends; (1) 100 wt% low-sulfur standard petro diesel (SD), (2) 100 wt% rapeseedmethyl ester biodiesel (B100) and (3) a blended fuel – B30 consisting of 30 wt% RME and 70 wt% SD. Thestudy focused mainly on emissions from transient engine operation, but includes also idling conditions.The gaseous emissions measured for the biodiesel fuel were in general in accordance with previousreported data in the literature, and compared to the standard petro diesel the emissions of CO was lowerwhile NOx emissions increased. The particulate mass concentration during transient operation wasalmost halved compared to when petro diesel was used and this was associated with a decrease in averageparticle size. The shift in particle mass and size was associated with a higher fraction of organic matterin general, considerable less PAH’s but a relative higher fraction of Oxy-PAH’s, when shifting frompetro diesel to biodiesel.
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| 24. |
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| 25. |
- Sandström, Niklas, 1981-, et al.
(författare)
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Laser-induced deep etching of glass for live cell assays
- 2021
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Ingår i: MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. - : Chemical and Biological Microsystems Society. ; , s. 579-580
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Konferensbidrag (refereegranskat)abstract
- Glass materials have excellent optical and chemical properties for microscopy-based live cell assays but state-of-the-art methods for microfabrication of Lab-on-Chip (LoC) devices are often limited by either complex manufacturing and/or low quality results. In this work, we have evaluated glass microwell array chips produced using a recently introduced laser-based microfabrication method. Three different types of microwell designs have been tested for imaging and screening of on-chip cell cultures and live cell assays.
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