| 1. |
- Backe, Björn, 1978-
(författare)
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An Integrated Development Approach for Monitoring and Simulation to Predict Functional Product Availability
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For nearly two decades, business models such as Functional Products have been in focus within research and of interest in the manufacturing industry. Functional product offers consist of hardware, software, service -support systems and management of operation which, when developed in an integrated manner, together provide the customer with an agreed-upon function with a specified level of availability. Compared to product-oriented sales, this type of business model can provide added value to customers, usually through an increase in the service content. Due to the total care commitment, offering Functional Products requires management of reliability and maintainability in order to meet the availability requirement of the function provided. The development of the Functional Product must include holistic analysis and prediction of the functional product availability performance to reduce technical and economic risks and ensure that the function is delivered according to contract. The research performed in this thesis presents an integrated development approach for monitoring and simulation to predict functional product availability. It is shown how the constituents of a functional product can be modelled in an integrated manner in order to simulate and predict functional product availability. A part of this modelling strategy is demonstrated through a simulation case example to show that is possible through this approach to evaluate the availability of different functional product designs. To support the development of the monitoring capability needed for availability simulations it is shown how it is possible to develop fault detection and diagnosis methods for fault detection systems based on data stream management systems. It is also shown how data stream forecasting can be used to predict failures due to faults occurring at short notice. Different fault detection methods have been developed, tested and evaluated on real industrial applications to verify applicability as queries on data streams, managed by data stream management systems. The results from these tests have been evaluated for their predictive performance and detection accuracy. Finally, methodological and technological approaches to monitoring and analysis in functional product development and similar business models to functional products are reviewed. The results showed that few research contributions address the information perspective in functional product development and similar business models holistically. The integrated development approach presented is a pragmatic approach to functional product development which is based on the merged research results of the papers included and knowledge domain presented.
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| 2. |
- Isaksson, Mats, 1961, et al.
(författare)
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Assessing 131I in thyroid by non-spectroscopic instruments - a European intercomparison exercise
- 2019
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Ingår i: Radiation Measurements. - : Elsevier BV. - 1350-4487 .- 1879-0925. ; 128:September
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Tidskriftsartikel (refereegranskat)abstract
- One of the issues of the Open Project for the European Radiation Research Area (OPERRA) was human thyroid monitoring in case of a large scale nuclear accident. This issue was covered in task 5.4 as project “CaThyMARA” (Child and Adult Thyroid Monitoring After Reactor Accident), which included several aspects of thyroid monitoring, e.g. screening of facilities able to perform thyroid monitoring in the European countries, dose estimation, modelling of detector response, and two intercomparison exercises. The intercomparison described in this paper focused on thyroid monitoring by non-spectrometric instruments, including gamma cameras and other instruments that were considered available for measurements made by members of the public. A total of 12 facilities from 7 European countries have participated and 43 various measuring devices have been evaluated. The main conclusion of this intercomparison is that the ability to make assessments of 131I activity in the thyroid to the exposed population after an accidental release must, on the average, be considered as good among the European laboratories taking part in this study. This intercomparison also gave the participants the possibility to calibrate the measuring devices for thyroid measurements of children where this procedure was not available before. A comprehensive report of the intercomparison is given.
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| 3. |
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| 4. |
- Rääf, Christopher, et al.
(författare)
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Restoring areas after a radioactive fallout : A multidisciplinary study on decontamination
- 2023
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Ingår i: Journal of Environmental Radioactivity. - : Elsevier. - 0265-931X .- 1879-1700. ; 270
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Tidskriftsartikel (refereegranskat)abstract
- Land remediation is an important part of restoration measures after a radioactive fallout containing long-lived fission products such as 137Cs. In this multidisciplinary study, we focused on three main issues related to remediation of contaminated urban areas. First, we assessed how much decontamination contributes to reducing resident radiation exposure and how much this reduction depends on the timing of implemented measures. Second, we calculated direct and indirect costs of decontamination in an industrialized country such as Sweden. Finally, in a survey study, we considered reactions of Swedish citizens to being given the hypothetical option of moving to a site decontaminated after radioactive fallout and how this predicted response might influence the design of contingency plans. The main findings are that clean-up operations must be done within the first few years after a fallout to contribute significantly to reducing residual dose. If conducted within 1-2 years, large-scale decontamination can, on average, avert 20-200 manSv per km2 residential area and unit ground deposition of 137Cs (1 MBq). The estimated direct costs (in 2020 purchasing power) would amount to 100 million Euro per km2 decontaminated residential area (comparable to Japanese estimates after the Fukushima accident), generating 39,000 m3 of radioactive waste on average, mainly in the form of 137Cs-contaminated topsoil. In our survey study of 2291 Swedish respondents about their willingness to return to decontaminated homes, women, families with resident children, and high-income earners exhibited more skepticism about returning, even if authorities were to deem it safe. The demographic pattern in attitudes was similar to that found among evacuees in the Fukushima prefecture after 2011. We conclude that predefined ranges of measured 137Cs ground deposition can be used as guidance for rescue leaders in the early post-accident phase in long-term planning for affected areas. This planning should include timing and intensity of decontamination measures, duration of evacuation, and risk communication to citizens. Because some citizens expressed both high risk perception and risk aversion, however, timely and dialogic communication is unlikely to limit a shift after the incident to an older and more male-dominated population composition. There is a risk that those who can afford to do so will move away, whereas people whose wealth is locked in property (houses or businesses) will feel stuck. Perceptions of unfairness may fray the social fabric and complicate resettlement, which in some cases may mean inefficient outlay of decontamination costs. We believe that the issue of monetary compensation to affected residents requires priority in future work.
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| 5. |
- Adman, Per, et al.
(författare)
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171 forskare: ”Vi vuxna bör också klimatprotestera”
- 2019
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Ingår i: Dagens nyheter (DN debatt). - Stockholm. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 26/9. Vuxna bör följa uppmaningen från ungdomarna i Fridays for future-rörelsen och protestera eftersom det politiska ledarskapet är otillräckligt. Omfattande och långvariga påtryckningar från hela samhället behövs för att få de politiskt ansvariga att utöva det ledarskap som klimatkrisen kräver, skriver 171 forskare i samhällsvetenskap och humaniora.
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| 6. |
- Ali, Yusuf, et al.
(författare)
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Experimental determination of concentration factors of Ni, Ru and Sb in the model diatom Phaeodactylum tricornutum
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the experimental determination of concentration factors (CF) for nickel, ruthenium and antimony in the model diatom Phaeodactylum tricornutum Bohlin (Bacillariophyceae), which was chosen as a representative of marine phytoplankton. Better determinations of these CF are needed to improve the modelling of marine ecosystems at release points, where radioactive pollutants enter the ecosystem, for more accurate predictions of radiation dose to humans caused by these pollutants. A literature study revealed that the currently implemented values of these CF are based on very scarce data, and a computational sensitivity study showed that the radiation dose caused by radioisotopes of these elements depend strongly on the phytoplankton CF. Nutrient-enriched water samples from Swedish coastal waters were used as a medium for growing of the diatom species P. tricornutum and radioactive isotopes of the studied elements were added to the cultures during the exponential growth phase. The radioactivity in the P. tricornutum and in the culture medium were measured separately and used for determination of CF. Conservative estimates of the CF based on this phytoplankton proxy on the present data are 6400 L/kg for nickel, 20,000 L/kg for ruthenium and 890 L/kg for antimony, with P. tricornutum biomass masses referring to dry weight. The estimates for nickel and ruthenium are similar to previously published values, which underpins the credibility of radiation dose calculations based on these values. The estimate for antimony is uncertain, but also, to our knowledge, represents the first published experimentally based data on this CF.
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| 7. |
- Alm, Anita, 1953, et al.
(författare)
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BMI status in Swedish children and young adults in relation to caries prevalence.
- 2011
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Ingår i: Swedish dental journal. - : Swedish Dental Association. - 0347-9994. ; 35:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Overweight and obesity are increasing as health problems at global level. Dental caries and obesity are both multifactorial diseases and are associated with dietary habits. The aim of the present study was to investigate the relationship between body weight status and caries prevalence in an unselected population followed from pre-school years to young adulthood. The present investigation was designed as a longitudinal analysis of the association between overweight/obesity and dental caries in one population at 3, 6, 15 and 20 years of age. The result shows that adolescents (15 years) and young adults (20 years) who are overweight/obese had a statistically significantly higher caries prevalence than normal-weight young people. At 6 years of age, the odds (OR) of having caries among obese children are 2.5 times higher than the odds for caries among six-year-old children of normal weight (p = 0.04). At 3 years of age, no association between overweight/obesity and caries was found. To conclude, overweight and obese adolescents and young adults had more caries than normal-weight individuals. The present study emphasises the need for multidisciplinary approaches to change the lifestyle factors causing both overweight/obesity and dental caries.
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| 8. |
- Almgren, Sara, 1979, et al.
(författare)
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Gamma radiation doses to people living in Western Sweden.
- 2008
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Ingår i: Journal of environmental radioactivity. - : Elsevier BV. - 0265-931X. ; 99:2, s. 394-403
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Tidskriftsartikel (refereegranskat)abstract
- Indoor environments contribute to gamma radiation in the general population. The aims of the present study were to investigate average gamma radiation doses in a rural and an urban area of Sweden, compare indoor dose rates with personal exposure, and study the effects of building characteristics on radiation levels. Radiation was measured with thermoluminescence dosimeters (TLDs). Repeated measurements were performed with TLDs worn by participants (n=46) and placed in their dwellings. Personal dose rates were 0.092microSv/h (rural) and 0.096microSv/h (urban). The mean effective gamma dose rates in dwellings were 0.091microSv/h (rural) and 0.11microSv/h (urban), which are higher than the world average. Dose rates in apartments were higher than in detached houses and higher for concrete than wooden dwellings. Personal dose rates were strongly associated with dwelling dose rates (r(p)=0.68, p<0.01) and could be modelled. Within-participant variability was low.
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| 9. |
- Almgren, Sara, 1979, et al.
(författare)
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GIS supported calculations of (137)Cs deposition in Sweden based on precipitation data.
- 2006
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Ingår i: The Science of the total environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 368:2-3, s. 804-13
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Tidskriftsartikel (refereegranskat)abstract
- It is of interest to know the spatial variation and the amount of (137)Cs e.g. in case of an accident with a radioactive discharge. In this study, the spatial distribution of the quarterly (137)Cs deposition over Sweden due to nuclear weapons fallout (NWF) during the period 1962-1966 was determined by relating the measured deposition density at a reference site to the amount of precipitation. Measured quarterly values of (137)Cs deposition density per unit precipitation at three reference sites and quarterly precipitation at 62 weather stations distributed over Sweden were used in the calculations. The reference sites were assumed to represent areas with different quarterly mean precipitation. The extent of these areas was determined from the distribution of the mean measured precipitation between 1961 and 1990 and varied according to seasonal variations in the mean precipitation pattern. Deposition maps were created by interpolation within a geographical information system (GIS). Both integrated (total) and cumulative (decay corrected) deposition densities were calculated. The lowest levels of NWF (137)Cs deposition density were noted in north-eastern and eastern parts of Sweden and the highest levels in the western parts of Sweden. Furthermore the deposition density of (137)Cs, resulting from the Chernobyl accident was determined for an area in western Sweden based on precipitation data. The highest levels of Chernobyl (137)Cs in western Sweden were found in the western parts of the area along the coast and the lowest in the east. The sum of the deposition densities from NWF and Chernobyl in western Sweden was then compared to the total activity measured in soil samples at 27 locations. Comparisons between the predicted values of this study show a good agreement with measured values and other studies.
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| 10. |
- Almgren, Sara, 1979, et al.
(författare)
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Long-term investigation of anthropogenic and naturally occurring radionuclides at reference sites in western Sweden.
- 2009
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Ingår i: Journal of environmental radioactivity. - : Elsevier BV. - 1879-1700 .- 0265-931X. ; 100:7, s. 599-604
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Tidskriftsartikel (refereegranskat)abstract
- In case of an accidental release of radioactive substances into the environment, it is important to quickly and reliably estimate the radiation dose received by people in the affected area, and to determine the extent of the contamination. Measurements of the extent of the release and the subsequent contamination can be facilitated if there are predetermined reference sampling sites with known background radiation and inventory of radionuclides. Since 1996, 34 reference sites for soil sampling, field gamma, and intensimeter measurements have been established in western Sweden. Time series data for dose rates and radioisotope inventory have been collected at these sites, allowing for the investigation of changes in these parameters over time. The mass activity densities for the uranium and thorium series elements varied approximately between 10 and 50 Bq/kg and between 10 and 40 Bq/kg, respectively. The mass activity density of (40)K was approximately in the range 300-800 Bq/kg. The radiation exposure due to (137)Cs was rather small in this area. The dose rates calculated from in situ measurement data showed that the contribution to the total dose rate was almost entirely due to naturally occurring radionuclides. The measured dose rate was about twice as high as the calculated rate, even after subtracting the contribution from cosmic radiation. This may be explained by the fact that intensimeters generally are calibrated to measure the quantity ambient dose equivalent, which should not underestimate the effective dose.
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