| 1. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 2. |
- Akos, Dennis, et al.
(författare)
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Receiver measured time in the VDL mode 4 system
- 2000
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Ingår i: IEEE 2000 Position Location and Navigation Symposium. - Piscataway, NJ : IEEE Communications Society. - 0780358724 ; , s. 309-316
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Konferensbidrag (refereegranskat)abstract
- This paper details an investigation into the receiver measured time (RMT) concept of VDL Mode 4, basically the ability to derive estimates of time from the transmission of the VDL Mode 4 signals themselves. The RMT concept is based on determining the accurate time of transmission by measuring the time of arrival (TOA) of a received signal. The reverse aspect, or that of user position, can also be computed in the same manner and all computed simulations hold for errors in position. If synchronized time is available, or can be derived, then the user position can be computed based on signals from known transmitter locations. A complete, end-to-end RMT simulation model for the Gaussian filtered frequency shift keying (GFSK) and differential 8-phase shift keying (D8PSK) modulation techniques has been developed in which various transmitters, channels and receiver models as well as an RMT measurement system have been included. The timing results, which are included, are described in terms of two-sigma errors as a function of signal-to-noise ratios (SNRs). The performance varies for the different receiver structures over the typical operation region and for a 1-bit differential GFSK detector the two-sigma error is as low as 0.40 microseconds, corresponding to a ranging error of approximately 120 meters. When incorporating co-channel interference (CCI), multipath and Doppler frequency shifts the RMT performance has been shown to decrease in terms of higher two-sigma errors
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| 3. |
- Andersson, Eva, 1955, et al.
(författare)
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Incidence of asthma among workers exposed to sulfur dioxide and other irritant gases
- 2006
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 27:4
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate whether repeated peak exposure (gassings) to sulphur dioxide (SO2) and other irritant gases increases the risk of new-onset asthma. A questionnaire was sent to 4,112 sulphite workers, of whom 1,919 completed the questionnaire and 396 completed the short-form questionnaire, which was sent out as a last reminder. A sample of 130 nonrespondents completed a telephone interview using the short-form questionnaire. The incidence of adult-onset, physician-diagnosed asthma during employment duration was analysed in relation to exposure to SO2 and gassings giving rise to respiratory symptoms. Incidence rates, as well as incidence rate ratios with 95% confidence interval (CI), were calculated. Further Cox regression models were used allowing assessment of hazard ratios (HR) stratified for sex and adjusted for atopy, smoking habits and age. The incidence rate for asthma among sulphite mill workers reporting gassings of SO2 was 6.2 out of 1,000 person-yrs, compared with 1.9 out of 1,000 person-yrs among subjects unexposed to SO2 and any gassings (HR (95% CI) 4.0 (2.1-7.7)). Among males reporting gassings to SO2, the HR (95% CI) for asthma was 5.8 (2.6-13) compared with unexposed males. In conclusion, repeated peak exposure to sulphur dioxide increased the incidence of asthma during work in sulphite pulp mills, which supports the hypothesis of irritant-induced asthma.
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| 4. |
- Andersson, Eva, 1955, et al.
(författare)
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Incidence of chronic bronchitis in a cohort of pulp mill workers with repeated gassings to sulphur dioxide and other irritant gases
- 2013
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Occupational exposure to irritants is associated with chronic bronchitis. The aim of this study was to elucidate whether repeated peak exposures with respiratory symptoms, gassings, to sulphur dioxide (SO2) and other irritant gases could increase the risk of chronic bronchitis.METHODS: The study population comprised 3,060 Swedish pulp mill workers (84% males) from a cohort study, who completed a comprehensive questionnaire with items on chronic bronchitis symptoms, smoking habit, occupational history, and specific exposures, including gassings. 2,037 have worked in sulphite mills. Incidence rates and hazard ratios (HRs) for the observation period, 1970-2000, in relation to exposure and the frequency of repeated gassings to SO2 and other irritant gases were calculated.RESULTS: The incidence rate for chronic bronchitis among workers with repeated gassings was 3.5/1,000 person-years compared with 1.5/1,000 person-years among unexposed workers (HR 2.1, 95% confidence interval (CI) 1.4-3.1). The risk was even higher in the subgroup with frequent gassings (HR 3.2, 95% CI 2.0-5.2), particularly among never-smokers (HR 8.7, 95% CI 3.5-22).CONCLUSIONS: Repeated gassings to irritant gases increased the incidence of chronic bronchitis in our study population during and after work in pulp mills, supporting the hypothesis that occupational exposures to irritants negatively affect the airways. These results underscore the importance of preventive actions in this work environment.
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| 5. |
- Baghdadchi, Amir, 1994-, et al.
(författare)
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Promoting austenite formation in laser welding of duplex stainless steel-impact of shielding gas and laser reheating
- 2021
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Ingår i: Welding in the World. - : Springer Science and Business Media LLC. - 0043-2288 .- 1878-6669. ; 65, s. 499-511
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Tidskriftsartikel (refereegranskat)abstract
- Avoiding low austenite fractions and nitride formation are major challenges in laser welding of duplex stainless steels (DSS). The present research aims at investigating efficient means of promoting austenite formation during autogenous laser welding of DSS without sacrificing productivity. In this study, effects of shielding gas and laser reheating were investigated in welding of 1.5-mm-thick FDX 27 (UNS S82031) DSS. Four conditions were investigated: Ar-shielded welding, N2-shielded welding, Ar-shielded welding followed by Ar-shielded laser reheating, and N2-shielded welding followed by N2-shielded laser reheating. Optical microscopy, thermodynamic calculations, and Gleeble heat treatment were performed to study the evolution of microstructure and chemical composition. The austenite fraction was 22% for Ar-shielded and 39% for N2-shielded as-welded conditions. Interestingly, laser reheating did not significantly affect the austenite fraction for Ar shielding, while the austenite fraction increased to 57% for N2-shielding. The amount of nitrides was lower in N2-shielded samples compared to in Ar-shielded samples. The same trends were also observed in the heat-affected zone. The nitrogen content of weld metals, evaluated from calculated equilibrium phase diagrams and austenite fractions after Gleeble equilibrating heat treatments at 1100 °C, was 0.16% for N2-shielded and 0.11% for Ar-shielded welds, confirming the importance of nitrogen for promoting the austenite formation during welding and especially reheating. Finally, it is recommended that combining welding with pure nitrogen as shielding gas and a laser reheating pass can significantly improve austenite formation and reduce nitride formation in DSS laser welds. © 2020, The Author(s).
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| 6. |
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| 7. |
- Bernhard, Jonte, 1953-, et al.
(författare)
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Alternating currents first : Experiences from designing a novel approach to teaching electric circuit theory
- 2016
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Ingår i: 44th Annual Conference of the European Society for Engineering Education - Engineering Education on Top of the World. - : European Society for Engineering Education (SEFI). - 9782873520144
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Konferensbidrag (refereegranskat)abstract
- BACKGROUND: Commonly in electric circuit theory courses, circuit laws are first introduced in the context of direct current (DC) electricity and first thereafter are alternating currents (AC) introduced. The extension of DC-theory to AC is quite easily done mathematically but is conceptually difficult for students. Engineering students have difficulties in understanding phase relationships and phasor representations in AC-electricity. Indeed, it has been suggested that phase should be seen as a threshold concept.PURPOSE: The purpose of this study was to investigate if a re-designed introductory electric circuit course could improve students’ understanding of important concepts in AC-electricity.METHOD and COURSE DESIGN: The course was re-designed introducing AC and DC electricity simultaneously. DC was introduced as a special case of AC with requency equals zero. The re-designed course was taught for the first time during the spring semester 2014 and a new textbook was written. A conceptual test was developed and first administered in 2013 to serve as a baseline and in subsequent years to evaluate the revised course. In 2014 the students’ courses of action in selected lab-groups were video-recorded.RESULTS: In the first revision cycle many students had difficulties to complete the labs in time. Students revealed a mixed response towards the revised course and the results on the conceptual test showed neglible improvement. In the second cycle revisions the number tasks were reduced and focus was laid on tasks that were identified as most important for contributing to the development of student understanding. As a result the learning gain improved with an effect size (Cohen’s delta) of 0.56. Also the course and the textbook were very well appreciated. In the third cycle only small revisions are made.CONCLUSION: The results show that that AC-electricity can be taught concurrently with DC. However, two revisions cycles was needed which demonstrates that curriculum development needs a sustained effort over a considerable period of time with continuous revisions in light of gained experiences. In further revision we will continue to refine the labs and to develop appropriate interactive lecture demonstrations for the lectures and to develop the problems.
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| 8. |
- Björk, Magnus, 1977, et al.
(författare)
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Exposed Datapath for Efficient Computing
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We introduce FlexCore, which is the first exemplar of a processor based on the FlexSoC processor paradigm. TheFlexCore utilizes an exposed datapath for increased performance. Microbenchmarks yield a performance boost of a factor of two over a traditional five-stage pipeline with the same functional units as the FlexCore.We describe our approach to compiling for the FlexCore.A flexible interconnect allows the FlexCore datapath to bedynamically reconfigured as a consequence of code generation. Additionally, specialized functional units may be introduced and utilized within the same architecture and compilation framework. The exposed datapath requires a wide control word. The conducted evaluation of two micro benchmarks confirms that this increases the instruction bandwidth and memory footprint. This calls for an efficient instruction decoding as proposed in the FlexSoC paradigm.
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| 9. |
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| 10. |
- Björner Brauer, Hanna, et al.
(författare)
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Pain Relieving Light - (How) Is it Possible?
- 2024. - 1
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Ingår i: IOP Science home Accessibility Help Journals Books Publishing Support Login IOP Conference Series: Earth and Environmental Science. - : Institute of Physics. - 1755-1307. ; 1320
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Konferensbidrag (refereegranskat)abstract
- About 15% of the population suffer from migraines and it is estimated that about 40% of all people with migraines would benefit from preventive treatment, but only 3-13% use it. Migraine is a huge burden for society and individuals. Migraines can be intensified by light, and some patients need to stay in a dark room until the attack is over. People with this type of photosensitivity show a clear preference for light color, specifically green, which has been shown to be more comfortable and even pain relieving in some cases. We will present a feasibility study with the aim of preparing a series of experiments to investigate if regular short-term green-light-exposure can prevent migraines. We will present findings from the literature, developed light equipment, and plans for future testing of migraine friendly light solutions.
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