| 21. |
- Ehnhage, Anders, et al.
(författare)
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Treatment of idiopathic rhinitis with kinetic oscillations : a multi-centre randomized controlled study
- 2016
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 136:8, s. 852-859
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Tidskriftsartikel (refereegranskat)abstract
- Conclusions: The potential effects of KOS are still uncertain regarding the most effective air pressure to be used as well as the physiological effects on the nasal mucosa. The results of the study do not support a convincing treatment effect by KOS on IR.Objectives: Idiopathic rhinitis (IR) is a common disorder, affecting ∼10-20% of the population. A new method for treating IR, Kinetic Oscillation Stimulation (KOS), has been reported to have beneficial effects on total vasomotor symptom scores (TVRSS). The primary objective with this study was to evaluate if a mean pressure of 65 mbar, pressure amplitude of 100 mbar, and 68Hz treatment with KOS had a positive effect on total vasomotor symptom scores (TVRSS), as compared with a mean pressure of 65 mbar, pressure amplitude of 4 mbar, and 68Hz treatment in patients with idiopathic rhinitis.Methods: Two hundred and seven patients were randomized (Full Analysis Set, FAS) in the study, including five visits and lasting for approximate to 25 weeks. All patients had two treatment episodes, and all patients had at least one treatment, meant as active, with high amplitude pressure for 10min in each nostril. Group 1 had two such treatments, and Group 2 had one treatment with low amplitude pressure, initially meant as placebo, on one occasion. Because of numerical improvements in these two groups, a new control group, Group 3, was introduced. They had one new control treatment where the balloon was inserted into the nose, without any air inflation and without oscillations.Results: KOS treatment with high amplitude pressure did not have significant beneficial effects as compared to low amplitude pressure on TVRSS. Numerical improvements in TVRSS and SNOT 22 were found when comparing high and low amplitude pressure treatments with uninflated balloon treatment. However, this part of the study was initially single-blinded, and these results were secondary objectives.
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| 22. |
- Ekenbäck, Andreas, et al.
(författare)
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Energetic neutral atom imaging of comets
- 2008
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 35:L05103
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Tidskriftsartikel (refereegranskat)abstract
- We present the first computer simulated images of energetic neutral atoms (ENAs) produced by charge exchange between solar wind protons and cometary neutrals. Proton bulk flow and temperature from MHD simulations are used along with a model of cometary neutral densities. The emission of hydrogen ENAs from the comet is then calculated using cross sections for the charge exchange collisions. The ENA production rate is integrated along lines of sight to produce an image of the fluxes. We find detection of hydrogen ENAs feasible and most favorable at solar zenith angles between 80 and 130 degrees.
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| 23. |
- Ekenbäck, Andreas, et al.
(författare)
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Energetic neutral atoms around HD 209458b : estimations of magnetospheric properties
- 2010
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Ingår i: Astrophysical Journal. - Bristol : Institute of Physics (IOP). - 0004-637X .- 1538-4357. ; 709:2, s. 670-679
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Tidskriftsartikel (refereegranskat)abstract
- HD 209458b is an exoplanet found to transit the disk of its parent star. Observations have shown a broad absorption signature about the Ly alpha stellar line during transit, suggesting the presence of a thick cloud of atomic hydrogen around the "hot Jupiter" HD 209458b. This work expands on an earlier work studying the production of energetic neutral atoms (ENAs) as a result of the interaction between the stellar wind and the exosphere. We present an improved flow model of HD 209458b and use stellar wind values similar to those in our solar system. We find that the ENA production is high enough to explain the observations, and we show that-using expected values for the stellar wind and exosphere-the spatial and velocity distributions of ENAs would give absorption in good agreement with the observations. We also study how the production of ENAs depends on the exospheric parameters and establish an upper limit for the obstacle standoff distance at approximately 4-10 planetary radii. Finally, we compare the results obtained for the obstacle standoff distance with existing exomagnetospheric models and show how the magnetic moment of HD 209458b can be estimated from ENA observations.
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| 24. |
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| 25. |
- Ekenbäck, Andreas, 1975-
(författare)
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Numerical modelling of ENAs from stellar wind interactions
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Energetic neutral atoms (ENAs) are produced whenever a stellar wind encounters a neutral atmosphere. If a stellar wind proton comes sufficiently close to a neutral a charge-exchange reaction may take place, transforming the proton into an ENA. Unaffected by magnetic and electric fields, ENAs provide an opportunity for global imaging of stellar wind interactions.This thesis presents methods and results of numerical modelling of stellar wind interactions. In particular it treats in depth production of ENAs at comets, Mars and the extrasolar planet HD 209458b.Sufficiently accurate numerical models of stellar wind interactions require extensive computations. Parallel computing has therefore been used throughout the work, both for fluid and particle simulations of space plasmas. This thesis describes the use of a general simulation tool, providing parallel computing for space plasma simulations.The thesis presents estimations of the magnitude and morphology of the ENA production at comets and HD 209458b. It compares the results obtained with observations and analyzes them in the light of ENA production at similar objects. Also, simulated ENA images for Mars were produced and compared to observations.
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| 26. |
- Eriksson, Jenny, 1975-, et al.
(författare)
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New ways of collecting individual travel information : Evaluation of data collection and recruitment methods
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The overall purpose of the project is to conduct a demonstration study that shows how two data collection methods that have been developed to collect travel survey data perform in the field, and how they perform compared with traditional TS (i.e., postal questionnaires and/or telephone interviews). The project is also intended to provide a better understanding of the ways in which different recruitment methods of respondents can be used so that future TS can be more cost effective.The two collection methods tested consist of a mobile app and an online questionnaire with a map to assist the respondents to identify travel destinations. Three recruitment methods were used, i.e., recruitment via random sampling, a web panel, and crowdsourcing. The portion of the random sample that received an online questionnaire was divided into two groups. Half the group was given no incentive, while the other half received a gift card worth SEK 100 after answering the questioner. Those who were recruited via a web panel and were to use the mobile app were rewarded in the form of a gift card worth SEK 100 if, at minimum, they made corrections to trips made on one day registered in the mobile app. A nonresponse analysis was performed of the random sample for both the online questionnaire and the mobile app. Cost estimates for each collection method and recruitment method were also performed, as were uncertainty estimates.Overall, the study shows that the mobile app registered significantly more trips per respondent than did the online questionnaire, while the distances travelled were comparable. There are several possible interpretations of this. One is that people who responded to the online questionnaire either forget about and/or combined short trips (particularly trips made for the purposes of leisure or shopping, and using the travel modes walking and car). One presumable explanation for this is that it is easier to confirm/correct the trips that the mobile app suggests than it is to recall and enter all trips in an online questionnaire. Another possible interpretation is that people responding to different data collection methods have different travel patterns. Yet another explanation is connected to technique issues regarding the different data collection methods.
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| 27. |
- Eriksson, Jenny, 1975-, et al.
(författare)
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Nya sätt att samla in individuell resvaneinformation : Utvärdering av insamlings- och rekryteringsmetoder
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Inom samverkansprogrammet Nästa generations resor och transporter, som Trafikanalys är huvudansvarig för, har man identifierat ett behov av att finna och utveckla nya lösningar för resvaneundersökningar (RVU:er). Bakgrunden till detta är bland annat sjunkande svarsfrekvenser med dagens metoder, vilket skulle kunna ge problem med representativiteten. Det anses som mycket angeläget att utveckla nya metoder för datainsamling för framtidens RVU:er, både på kort och lång sikt.Det övergripande syftet med projektet är att göra en demonstrationsstudie som visar hur två datainsamlingsmetoder som har utvecklats för att samla in resevaneundersökningsdata presterar i fält, samt hur de presterar jämfört med ”traditionell” RVU (postal enkät och/eller telefonintervjuer). Projektet syftar också till att få bättre förståelse för hur olika rekryteringsmetoder kan användas för att framtida RVU:er ska kunna bli mer kostnadseffektiva. De två insamlingsmetoder som testats är webbenkät med karta och mobilapp. Tre rekryteringsmetoder har använts och dessa är rekrytering via slumpmässigt urval, webbpanel och crowdsourcing.
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| 28. |
- Farrell, William M., et al.
(författare)
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The dust, atmosphere, and plasma at the moon
- 2024
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Ingår i: Reviews in Mineralogy and Geochemistry, Mineralogical Society of America. - : Walter de Gruyter. - 1529-6466 .- 1943-2666. ; 89, s. 563-609
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Tidskriftsartikel (refereegranskat)
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| 29. |
- Fatemi, Shahab, et al.
(författare)
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A modelling approach to infer the solar wind dynamic pressure from magnetic field observations inside Mercury's magnetosphere
- 2018
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 614
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The lack of an upstream solar wind plasma monitor when a spacecraft is inside the highly dynamic magnetosphere of Mercury limits interpretations of observed magnetospheric phenomena and their correlations with upstream solar wind variations.Methods: We used AMITIS, a three-dimensional GPU-based hybrid model of plasma (particle ions and fluid electrons) to infer the solar wind dynamic pressure and Alfvén Mach number upstream of Mercury by comparing our simulation results with MESSENGER magnetic field observations inside the magnetosphere of Mercury. We selected a few orbits of MESSENGER that have been analysed and compared with hybrid simulations before. Then we ran a number of simulations for each orbit (~30–50 runs) and examined the effects of the upstream solar wind plasma variations on the magnetic fields observed along the trajectory of MESSENGER to find the best agreement between our simulations and observations.Results: We show that, on average, the solar wind dynamic pressure for the selected orbits is slightly lower than the typical estimated dynamic pressure near the orbit of Mercury. However, we show that there is a good agreement between our hybrid simulation results and MESSENGER observations for our estimated solar wind parameters. We also compare the solar wind dynamic pressure inferred from our model with those predicted previously by the WSA-ENLIL model upstream of Mercury, and discuss the agreements and disagreements between the two model predictions. We show that the magnetosphere of Mercury is highly dynamic and controlled by the solar wind plasma and interplanetary magnetic field. In addition, in agreement with previous observations, our simulations show that there are quasi-trapped particles and a partial ring current-like structure in the nightside magnetosphere of Mercury, more evident during a northward interplanetary magnetic field (IMF). We also use our simulations to examine the correlation between the solar wind dynamic pressure and stand-off distance of the magnetopause and compare it with MESSENGER observations. We show that our model results are in good agreement with the response of the magnetopause to the solar wind dynamic pressure, even during extreme solar events. We also show that our model can be used as a virtual solar wind monitor near the orbit of Mercury and this has important implications for interpretation of observations by MESSENGER and the future ESA/JAXA mission to Mercury, BepiColombo.
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| 30. |
- Fatemi, Shahab, et al.
(författare)
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Effects of protons deflected by lunar crustal magnetic fields on the global lunar plasma environment
- 2014
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Ingår i: Journal of Geophysical Research - Space Physics. - : John Wiley & Sons. - 2169-9380 .- 2169-9402. ; 119:8, s. 6095-6105
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Tidskriftsartikel (refereegranskat)abstract
- Solar wind plasma interaction with lunar crustal magnetic fields is different than that of magnetized bodies like the Earth. Lunar crustal fields are, for typical solar wind conditions, not strong enough to form a (bow)shock upstream but rather deflect and perturb plasma and fields. Here we study the global effects of protons reflected from lunar crustal magnetic fields on the lunar plasma environment when the Moon is in the unperturbed solar wind. We employ a three-dimensional hybrid model of plasma and an observed map of reflected protons from lunar magnetic anomalies over the lunar farside. We observe that magnetic fields and plasma upstream over the lunar crustal fields compress to nearly 120% and 160% of the solar wind, respectively. We find that these disturbances convect downstream in the vicinity of the lunar wake, while their relative magnitudes decrease. In addition, solar wind protons are disturbed and heated at compression regions and their velocity distribution changes from Maxwellian to a non-Maxwellian. Finally, we show that these features persists, independent of the details of the ion reflection by the magnetic fields.
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