| 3551. |
- Ahlberg, Anders
(author)
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Teaching and learning in hard science research environments: views of academics and educational developers
- 2008
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In: Higher Education Research and Development. - : Informa UK Limited. - 0729-4360 .- 1469-8366. ; 27:2, s. 133-142
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Journal article (peer-reviewed)abstract
- Abstract in UndeterminedObligatory educational training of Swedish university teachers rarely involves senior teaching staff from research-dominated environments, despite the positive effects of junior staff training. Senior science academics were surveyed to gauge their views on the principles of teaching and learning and of teaching rewards. These views were compared with educational developers' views on 'ideal values of academics' and on educational rewards. Based on this study, it is suggested that to reduce inherent teaching-research conflicts, convergence of teaching and research, in terms of teaching design and curriculum content, is necessary. To involve and convince science researchers who teach, educational staff development should probably focus on didactic aspects of their scientific disciplines and rely largely on empirical evidence.
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| 3552. |
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| 3553. |
- Ahlberg, Anders, et al.
(author)
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The Jurassic of Skåne, Southern Sweden
- 2003
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In: Geological Survey of Denmark and Greenland Bulletin. - 1811-4598. ; 1, s. 527-541
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Journal article (peer-reviewed)abstract
- In Sweden, Jurassic strata are restricted to Skåne and adjacent offshore areas. Jurassic sedimentary rocks predominantly comprise sandy to muddy siliciclastics, with subordinate coal beds and few carbonate-rich beds. During Mesozoic times, block-faulting took place in the Sorgenfrei– Tornquist Zone, a tectonic zone which transects Skåne in a NW–SE direction. The Jurassic depositional environments in Skåne were thus strongly influenced by uplift and downfaulting, and to some extent by volcanism. Consequently, the sedimentary record reveals evidence of numerous transgressions, regressions and breaks in sedimentation. Relative sea-level changes played a significant role in controlling the facies distribution, as deposition mainly took place in coastal plain to shallow shelf environments. The alluvial deposits in Skåne include floodplain palaeosols, autochthonous coals, overbank sandstones, and stream channel pebbly sandstones. Restricted marine strata comprise intertidal heteroliths with mixed freshwater and marine trace fossil assemblages, and intertidal delta distributary channel sandstones. Shallow marine sediments encompass subtidal and shoreface sandstones with herringbone structures, and bioturbated mudstones with tempestite sandstones. Offshore deposits typically comprise extensively bioturbated muddy sandstones. Floral remains, palaeopedology, clay mineralogy and arenite maturity indicate a warm and humid climate in Skåne throughout the Jurassic, possibly with slightly increasing aridity towards the end of the period. Most Jurassic strata in Skåne have been subjected to mild burial diagenesis, and the petroleum generative window has rarely been reached.
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| 3554. |
- Ahlberg, Anders, et al.
(author)
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Triassic-Jurassic weathering and clay mineral dispersal in basement areas and sedimentary basins of southern Sweden
- 2003
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In: Sedimentary Geology. - 0037-0738. ; 161:1-2, s. 15-29
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Journal article (peer-reviewed)abstract
- The basement rocks of southern Sweden were deeply weathered in Late Triassic through Cretaceous times, and possibly even earlier. Sub-Mesozoic saprolites formed, presumably due to long-term warmth and humidity, in conjunction with decomposition of abundant organic matter and subsequent infiltration of acidic water. The upper parts of the weathering profiles were subjected to intense leaching and kaolinitisation whereas the less evolved deep weathering front is enriched in smectite. Thus. any erosion prior to full regolith development, or extraordinary deep erosion, released less developed, smectite-rich weathering material to the Late Triassic-Jurassic receiving basins. Mesozoic sedimentary successions in Southern Sweden show high detrital smectite and/or kaolinite contents, moderate illite contents and low chlorite contents, compatible with expected mid-latitude warm equable greenhouse conditions. Norian and older Triassic haematite-cemented continental arkoses and smectite-dominated clays (smectitemuch greater thankaolinite) were clearly formed in and settings. Front the Rhaetian and throughout the Jurassic, humid onshore conditions sustained abundant plant and peat accumulation, early diagenetic meteoric flushing, and intense chemical weathering. Kaolinite is therefore a dominating detrital clay mineral in these sedimentary successions (kaolinite = illitemuch greater thanchlorite and smectite (I/S)). Minor quantitative variations in clay mineralogy within the "humid climate" Rhaetian-Jurassic sedimentary successions are difficult to interpret. In deltaic coal-bearing successions, the detrital clay mineral composition is conspicuously constant (kaolinite = illite-chlorite), possibly due to post-depositional clay mineral transformation. Conversely, in shallow marine deposits, some quantitative variation is notable (kaolinite approximate to illite>variable smectitemuch greater thanchlorite). This may reflect that the original detrital composition was better preserved in shallow marine settings. Smectitic clay minerals associated with gypsum and caliche nodules ambiguously indicate increased aridity towards the end of the Jurassic. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 3555. |
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| 3556. |
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| 3557. |
- Ahlberg, Beth Maina, 1949-, et al.
(author)
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"A child, a tree" : Challenges in building collaborative relations in a community research project in a Kenyan context
- 2016
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In: Action Research. - : Sage Publications. - 1476-7503 .- 1741-2617. ; 14:3, s. 257-275
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Journal article (peer-reviewed)abstract
- This paper highlights the potential for basing participatory action research on priorities identified by communities. The case builds on a research project by the Social Science Medicine Africa Network (Soma-net) focusing on AIDS prevention among school youth in Kajiado in Kenya during 2003-2006. It became clear from that study just how complex it is to promote open communication on issues of sexuality considered critical for sexual health promotion. Towards the end of that study a spin-off in the form of a concept a child, a tree or tree planting evolved and the research thereafter continued as a partnership between the school community and the researchers. The focus then was on understanding how health promotion could be integrated into other aspects of community life. The concept and tree planting when implemented created a sense of ownership among the pupils largely because they were placed at the centre of the development activities. The story illuminates the nature of change developing in the course of the project, but also the challenges and complexity of creating and maintaining collaborative relations in the face of cultural and gender power dynamics and interventions imposed from outside the community.
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| 3558. |
- Ahlberg, Erik, et al.
(author)
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Effect of salt seed particle surface area, composition and phase on secondary organic aerosol mass yields in oxidation flow reactors
- 2019
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In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 19:4, s. 2701-2712
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Journal article (peer-reviewed)abstract
- Atmospheric particulate water is ubiquitous, affecting particle transport and uptake of gases. Yet, research on the effect of water on secondary organic aerosol (SOA) mass yields is not consistent. In this study, the SOA mass yields of an α-pinene and m-xylene mixture, at a concentration of 60 μgm-3, were examined using an oxidation flow reactor operated at a relative humidity (RH) of 60% and a residence time of 160 s. Wet or dried ammonium sulfate and ammonium nitrate seed particles were used. By varying the amount of seed particle surface area, the underestimation of SOA formation induced by the short residence time in flow reactors was confirmed. Starting at a SOA mass concentration of 5 μgm-3, the maximum yield increased by a factor of 2 with dry seed particles and on average a factor of 3.2 with wet seed particles. Hence, wet particles increased the SOA mass yield by 60% compared to the dry experiment. Maximum yield in the reactor was achieved using a surface area concentration of 1600 μm2 cm-3. This corresponded to a condensational lifetime of 20 s for low-volatility organics. The O V C ratio of SOA on wet ammonium sulfate was significantly higher than when using ammonium nitrate or dry ammonium sulfate seed particles, probably due to differences in heterogeneous chemistry.
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| 3559. |
- Ahlberg, Erik, et al.
(author)
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Measurement report : Black carbon properties and concentrations in southern Sweden urban and rural air-the importance of long-range transport
- 2023
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In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 23:5, s. 3051-3064
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Journal article (peer-reviewed)abstract
- Soot, or black carbon (BC), aerosol is a major climate forcer with severe health effects. The impacts depend strongly on particle number concentration, size and mixing state. This work reports on two field campaigns at nearby urban and rural sites, 65gkm apart, in southern Sweden during late summer 2018. BC was measured using a single-particle soot photometer (SP2) and Aethalometers (AE33). Differences in BC concentrations between the sites are driven primarily by local traffic emissions. Equivalent and refractory BC mass concentrations at the urban site were on average a factor 2.2 and 2.5, with peaks during rush hour up to a factor g1/44, higher than the rural background levels. The number fraction of particles containing a soot core was significantly higher in the city. BC particles at the urban site were on average smaller by mass and had less coating owing to fresh traffic emissions. The organic components of the fresh traffic plumes were similar in mass spectral signature to hydrocarbon-like organic aerosol (HOA), commonly associated with traffic. Despite the intense local traffic (g1/4g30g000 vehicles passing per day), PM1, including organic aerosol, was dominated by aged continental air masses even at the curbside site. The fraction of thickly coated particles at the urban site was highly correlated with the mass concentrations of all measured chemical species of PM1, consistent with aged, internally mixed aerosol. Trajectory analysis for the whole year showed that air masses arriving at the rural site from eastern Europe contained approximately double the amount of BC compared to air masses from western Europe. Furthermore, the largest regional emissions of BC transported to the rural site, from the Malmö-Copenhagen urban area, are discernible above background levels only when precipitation events are excluded. We show that continental Europe and not the Malmö-Copenhagen region is the major contributor to the background BC mass concentrations in southern Sweden.
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| 3560. |
- Ahlberg, Erik, et al.
(author)
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No particle mass enhancement from induced atmospheric ageing at a rural site in northern Europe
- 2019
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In: Atmosphere. - : MDPI AG. - 2073-4433. ; 10:7
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Journal article (peer-reviewed)abstract
- A large portion of atmospheric aerosol particles consists of secondary material produced by oxidation reactions. The relative importance of secondary organic aerosol (SOA) can increase with improved emission regulations. A relatively simple way to study potential particle formation in the atmosphere is by using oxidation flow reactors (OFRs) which simulate atmospheric ageing. Here we report on the first ambient OFR ageing experiment in Europe, coupled with scanning mobility particle sizer (SMPS), aerosol mass spectrometer (AMS) and proton transfer reaction (PTR)-MS measurements. We found that the simulated ageing did not produce any measurable increases in particle mass or number concentrations during the two months of the campaign due to low concentrations of precursors. Losses in the reactor increased with hydroxyl radical (OH) exposure and with increasing difference between ambient and reactor temperatures, indicating fragmentation and evaporation of semivolatile material.
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