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- Pallon, Jan, et al.
(författare)
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At the Tip of an MeV Beam: Provoking Cells and Performing Tomographic Imaging
- 2009
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Ingår i: Acta Physica Polonica A. - 0587-4246. ; 115:2, s. 501-506
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Konferensbidrag (refereegranskat)abstract
- Biological applications of ion beams have recently become a new important research field using single ion hit facilities to study individual living cells and their response to the hit of a counted number of ions. One motivation is the search for a better understanding of the fundamental processes taking place in cells and organs as a result of irradiation. Another comes from the increasing interest in using high energy protons and heavy ions as a modality for radiotherapy of deep seated tumours. In the view of treatment efficiency, study of cell culture behaviour under controlled radiation experiments, and in different chemical environments at single ion hit facilities, is a first step towards a better understanding of the processes. Tomographic techniques are applicable to situations where you need information of the inside of an object but do not want to section it into thin slices or cannot do it. Using focused MeV ion beams for tomography restricts the sample size to the order of 10-100 mu m, depending of the initial energy. On the other hand, the ability to focus at a sub-micrometer level makes ion beams well suited for analyses of small sized objects as cells, spores, etc. The scanning transmission ion microscopy mode of tomography gives the mass density and corresponding morphological structure of holes and pores. It can then be used to correct the results from the other mode, particle induced X-ray emission tomography. Here is discussed a porosity analysis of bentonite clay that is planned to form an important buffer zone around canisters filled with spent nuclear reactor fuel waste deposited 500 m underground in Sweden.
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- Pignatelli, Francesco, et al.
(författare)
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Predictions of Spray Combustion using Conventional Category A Fuels and Exploratory Category C Fuels
- 2023
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Ingår i: AIAA SCITECH 2023 Forum. - Reston, Virginia : American Institute of Aeronautics and Astronautics. - 9781624106996
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Konferensbidrag (refereegranskat)abstract
- Aviation currently contributes about 3% of the world’s CO2 emissions, 5% of the global warming, and 35% of the trade. Reducing the emissions and the global warming from aviation is thus essential. Many approaches to achieve this goal are underway, including H2, fuel cells, and batteries, but also by replacing the fossil jet fuel with sustainable jet fuel from non-fossil feedstocks. This involves many challenges, and among them we have the issue of current jet engines being developed for existing fossil jet fuels. To facilitate the change towards sustainable jet fuel, typically having different thermophysical and combustion properties compared to fossil jet fuels, we need to analyze the sensitivity of combustion to other fuels, having a wider range of thermophysical specifications. Here, we examine combustion of n-heptane, n-dodecane, Jet A, and two test fuels, C1 and C5 in three different combustors. The first and second cases are axisymmetric and rectilinear pre-vaporized premixed bluff-body stabilized flames, whereas the third is a single sector helicopter combustor for liquid fuel. A Finite Rate Chemistry (FRC) Large Eddy Simulation (LES) model is used together with small comprehensive reaction mechanisms of ~300 reactions. Comparison with experimental data is performed for the pre-vaporized combustor configurations. Good agreement is generally observed, and small to marginal differences in combustion behavior is observed between the different fuels.
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- Ahlström, Christer, et al.
(författare)
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Dangerous use of mobile phones and other communication devices while driving : A toolbox of counter-measures
- 2013
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Ingår i: Proceedings of the 16th International Conference Road Safety on Four Continents. - Linköping : Statens väg- och transportforskningsinstitut.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of mobile phone and similar devices while driving has been a topic of discussion and research for several years. It is now an established fact that driving performance is deteriorated due to distraction but no clear conclusions can yet be drawn concerning influence on crash rates. Better studies on this relationship is needed. Most countries in Europe and many countries elsewhere have introduced different types of bans for handheld devices. Sweden has, however, no such bans. VTI was commissioned by the Swedish Government to outline possible means to reduce the dangerous usage of mobile phones and other communication devices while driving as alternatives to banning. This task was a result of a previous VTI-state-of-the-art review of research on mobile phone and other communication device usage while driving. One of the findings in the review was that bans on handheld phones did not appear to reduce the number of crashes.Eighteen different countermeasures in three main areas were suggested. (1) Technical solutions such as countermeasures directed towards the infrastructure, the vehicle and the communication device. (2) Education and information, describing different ways to increase knowledge and understanding among stakeholders and different driver categories. (3) Different possibilities for how society, industry and organisations can influence the behaviour of individuals, via policies, rules, recommendations and incentives. Our conclusion is that a combination of different countermeasures is needed – where education and information to the drivers are combined with support and incentives for a safe usage of different communication devices.
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