| 1. |
- Ingason, Haukur, et al.
(författare)
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The Metro Project : Final report
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report compiles the results from the METRO project. The different parts of theproject – design fires, evacuation, integrated fire control, smoke control, extraordinarystrain onconstructions and fire- and rescue operations – are presented separately.The most complicated and expensive part of the project was the performance of thelarge scale fire and explosion tests in the Brunsberg tunnel, where the maximum heatrelease rates measured from the metro wagon was 77 MW.The main results from the project are new recommendations regarding design firesin mass transport systems, identification of key factors for fire and smoke spread in tunnelsand at stations as well as regarding the difficulties for disabled persons to evacuatefrom trains in tunnels, new recommended types of way guiding systems, safer design incase of explosions in trains and evaluation of the fire and rescue services’ possibilitiesand limitations in underground mass transport systems.
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| 3. |
- Ahlström, Anders, 1973-
(författare)
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Aerolastic simulation of wind turbine dynamics
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work in this thesis deals with the development of an aeroelastic simulation tool for horizontal axis wind turbine applications. Horizontal axis wind turbines can experience significant time varying aerodynamic loads, potentially causing adverse effects on structures, mechanical components, and power production. The needs for computational and experimental procedures for investigating aeroelastic stability and dynamic response have increased as wind turbines become lighter and more flexible. A finite element model for simulation of the dynamic response of horizontal axis wind turbines has been developed. The developed model uses the commercial finite element system MSC.Marc, focused on nonlinear design and analysis, to predict the structural response. The aerodynamic model, used to transform the wind flow field to loads on the blades, is a Blade-Element/Momentum model. The aerodynamic code is developed by The Swedish Defence Research Agency (FOI, previously named FFA) and is a state-of-the-art code incorporating a number of extensions to the Blade-Element/Momentum formulation. The software SOSIS-W, developed by Teknikgruppen AB was used to generate wind time series for modelling different wind conditions. The method is general, and different configurations of the structural model and various type of wind conditions can be simulated. The model is primarily intended for use as a research tool when influences of specific dynamic effects are investigated. Verification results are presented and discussed for an extensively tested Danwin 180 kW stall-controlled wind turbine. Code predictions of mechanical loads, fatigue and spectral properties, obtained at different conditions, have been compared with measurements. A comparison is also made between measured and calculated loads for the Tjæreborg 2 MW wind turbine during emergency braking of the rotor. The simulated results correspond well to measured data.
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| 4. |
- Andrén, Peter
(författare)
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Development and results of the Swedish road deflection tester
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A project to construct a high-speed road deflection tester was initiated in the 1991. A mid-sized truck was used as a carrier for the first prototype. The results were promising and it was decided to build a full-size truck system. The new vehicle, based on a Scania R143 ML, was completed in 1997. The Road Deflection Tester (RDT) is equipped with two arrays of twenty noncontact laser sensors that collects transversal surface profiles at normal traffic speeds. One profile, placed between the wheel axles, constitutes an unloaded case. The other profile, just behind the rear axle of the vehicle, constitutes the loaded case. By subtracting the front cross profile from the corresponding rear one, the "deflection profile" is assessed. The deflection is assumed to vary with the stiffness of the road. In order to produce a large load on the rear wheels the engine was mounted in the back of the vehicle, slightly behind the rear axle. In testing mode the rear axle force is approximately 112 kN, and the front axle force is about 30 kN. An incremental wheel pulse transducer, two force transducers and two accelerometers, an optical speedometer and a gyroscope are also mounted on the RDT. The first test programme was carried out in 1998. Due to the careful choice of test sections, data from these sections still produce the best results. A smaller test programme was carried out in 2001, and a larger one in 2002 when the RDT was taken to England and France for demonstration. Promising results, both on an aggregated scale and for individual test sections, have been obtained. The RDT compares favourably with the Falling Weight Deflectometer. Short histories of road construction and road research give some historical and cultural background to the more recent developments. A more comprehensive history of rolling deflectographs presents all devices found in the literature from the start in the mid-fifties when the California Traveling Deflectograph and Lacroix Deflectograph were constructed, to the latest laser based High-Speed Deflectograph. Many references are given for further reading. The data acquisition hardware on the RDT system consist of sensors, signal converters, signal processing cards, an industrial computer for data communication, and an ordinary PC for operating the equipment and data storage. The software used to evaluate the data is written entirely in Matlab. Many levels of pre-processing make evaluation relatively fast, and the modularised design makes it easy to implement new evaluation algorithms in a clean and efficient way. A literature survey on the deformations of solids under static and moving load is presented in Appendix A. The static case started with Boussinesq in 1885, was much developed in the sixties, but since the eighties only a very limited amount of new results have been published. The moving load case, on the other hand, is still an field of active research and development.
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| 6. |
- Bignert, Anders, et al.
(författare)
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Comments Concerning the National Swedish Contaminant Monitoring Programme in Marine Biota, 2006
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report gives a summary of the monitoring activities within the national Swedishcontaminant programme in marine biota. It is the result from the joint efforts of: theInstitute of Applied Environmental Research at Stockholm University (analyses oforganochlorines), the Centre for Environmental Monitoring at the University of Agriculture(analyses of heavy metals) and the Contaminant Research Group at the Swedish Museumof Natural History (co-ordination, sample collection administration, sample preparation,recording of biological variables, minor additional analyses of organochlorines, storage offrozen biological tissues in the Environmental Specimen Bank for retrospective studies,data preparation and statistical evaluation). The monitoring programme is financiated by theEnvironmental Protection Agency (EPA) in Sweden.The data of concern in this report represent the bioavailable part of the investigatedcontaminants i.e. the part that has virtually passed through the biological membranes andmay cause biological effects. The objectives of the monitoring program in marine biotacould be summarised as follows:• to estimate the levels and the normal variation of various contaminants in marine biotafrom several representative sites, uninfluenced by local sources, along the Swedish coasts.The goal is to describe the general contaminant status and to supply reference values forregional and local monitoring programmes• to monitor long term time trends and to estimate the rate of found changes.quantified objective: to detect an annual change of 10% within a time period of 10 years with a power of 80%at a significance level of 5%.• to estimate the response in marine biota of measures taken to reduce the discharges ofvarious contaminantsquantified objective: to detect a 50% decrease within a time period of 10 years with a power of 80% at asignificance level of 5%.• to detect incidents of regional influence or widespread incidents of ‘Chernobyl’-character and to act as watchdog monitoring to detect renewed usage of bannedcontaminants.quantified objective: to detect an increase of 200% a single year with a power of 80% at a significance level of5%.• to indicate large scale spatial differencesquantified objective: to detect differences of a factor 2 between sites with a power of 80% at a significancelevel of 5%.• to explore the development and regional differences of the composition and pattern ofe.g. PCB’s, HCH’s and DDT’s as well as the ratios between various contaminants.• the time series are also relevant for human consumption since important commercial fishspecies like herring and cod are sampled. A co-operation with the Swedish FoodAdministration is established. Sampling is also co-ordinated with SSI (Swedish RadiationProtection Authority) for analysing radionuclides in fish and blue mussels (HELCOM,1992).• all analysed, and a large number of additional specimens, of the annually systematicallycollected material are stored frozen in the Environmental Specimen Bank.. This invaluable5material enables future retrospective studies of contaminants impossible to analyse today aswell as control analyses of suspected analytical errors.• although the programme is focused on contaminant concentration in biota, also thedevelopment of biological variables like e.g. condition factor (CF), liver somatic index(LSI) and fat content are monitored at all sites. At a few sites, integrated monitoring withfish physiology and population are running in co-operation with the University ofGothenburg and the Swedish Fishery Board.• experiences from the national program with several time series of over 25 years can beused in the design of regional and local monitoring programmes.• the perfectly unique material of high qualityand long time series is further used to explorerelationships among biological variables and contaminants concentrations in varioustissues; the effects of changes in sampling strategy, the estimates of variance componentsand the influence on the concept of power etc.• the accessibility of high quality data collected and analysed in a consistent manner is anindispensable prerequisite to evaluate the validity of hypothesis and models concerning thefate and distribution of various contaminants. It could furthermore be used as input of ‘real’data in the ongoing model building activities concerning marine ecosystems in general andin the Baltic and North Sea environment in particular.• the contaminant programme in marine biota constitute an integrated part of the nationalmonitoring activities in the marine environment as well as of the international programmeswithin ICES, OSPARCOM and HELCOM.The present report displays the timeseries of analysed contaminants in biota andsummarises the results from the statistical treatment. It does not in general give thebackground or explanations to significant changes found in the timeseries. Increasingconcentrations thus, urge for intensified studies.Short comments are given for temporal trends as well as for spatial variation and, for somecontaminants, differences in geometric mean concentration between various species caughtat the same site. Sometimes notes of seasonal variation and differences in concentrationbetween tissues in the same species are given. This information could say something aboutthe relative appropriateness of the sampled matrix and be of help in designing monitoringprogrammes. In the temporal trend part, an extract of the relevant findings is summarised inthe 'conclusion'-paragraph. It should be stressed though, that geographical differences maynot reflect antropogenic influence but may be due to factors like productivity, temperature,salinity etc.The report is continuously updated. The date of the latest update is reported at the beginningof each chapter. The creation date of each figure is written in the lower left corner.
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| 7. |
- Bignert, Anders, et al.
(författare)
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Comments Concerning the National Swedish Contaminant Monitoring Programme in Marine Biota, 2008
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report gives a summary of the monitoring activities within the national Swedish contaminant programme in marine biota. It is the result from the joint efforts of: the Department of Applied Environmental Science at Stockholm University (analyses of organochlorines), the Department of Environmental Assessment at Swedish University of Agricultural Sciences (analyses of heavy metals), Department of Chemistry at Umeå University (analyses of PCDD/PCDF) and the Department of Contaminant Research at the Swedish Museum of Natural History (co-ordination, sample collection administration, sample preparation, recording of biological variables, storage of frozen biological tissues in the Environmental Specimen Bank for retrospective studies, data preparation and statistical evaluation). The monitoring programme is financiated by the Environmental Protection Agency (EPA) in Sweden.The data of concern in this report represent the bioavailable part of the investigated contaminants i.e. the part that has virtually passed through the biological membranes and may cause toxic effects. The objectives of the monitoring program in marine biota could be summarised as follows:• to estimate the levels and the normal variation of various contaminants in marine biota from several representative sites, uninfluenced by local sources, along the Swedish coasts. The goal is to describe the general contaminant load and to supply reference values for regional and local monitoring programmes• to monitor long term time trends and to estimate the rate of found changes.quantified objective: to detect an annual change of 10% within a time period of 10 years with a power of 80% at a significance level of 5%.• to estimate the response in marine biota of measures taken to reduce the discharges of various contaminantsquantified objective: to detect a 50% decrease within a time period of 10 years with a power of 80% at a significance level of 5%.• to detect incidents of regional influence or widespread incidents of ‘Chernobyl’- character and to act as watchdog monitoring to detect renewed usage of banned contaminants.quantified objective: to detect an increase of 200% a single year with a power of 80% at a significance level of 5%.• to indicate large scale spatial differencesquantified objective: to detect differences of a factor 2 between sites with a power of 80% at a significance level of 5%.• to explore the development and regional differences of the composition and pattern of e.g. PCB’s, HCH’s and DDT’s as well as the ratios between various contaminants.• the time series are also relevant for human consumption since important commercial fish species like herring and cod are sampled. A co-operation with the Swedish Food Administration is established. Sampling is also co-ordinated with SSI (Swedish Radiation Protection Authority) for analysing radionuclides in fish and blue mussels (HELCOM, 1992).• all analysed, and a large number of additional specimens, of the annually systematically collected material are stored frozen in the Environmental Specimen Bank.. This invaluable4material enables future retrospective studies of contaminants impossible to analyse today as well as control analyses of suspected analytical errors.• although the programme is focused on contaminant concentration in biota, also the development of biological variables like e.g. condition factor (CF), liver somatic index (LSI) and fat content are monitored at all sites. At a few sites, integrated monitoring with fish physiology and population are running in co-operation with the University of Gothenburg and the Swedish Board of Fisheries.• experiences from the national programme with several time series of over 25 years can be used in the design of regional and local monitoring programmes.• the perfectly unique material of high quality and long time series is further used to explore relationships among biological variables and contaminant concentrations in various tissues; the effects of changes in sampling strategy, the estimates of variance components and the influence on the concept of power etc.• the accessibility of high quality data collected and analysed in a consistent manner is an indispensable prerequisite to evaluate the validity of hypothesis and models concerning the fate and distribution of various contaminants. It could furthermore be used as input of ‘real’ data in the ongoing model building activities concerning marine ecosystems in general and in the Baltic and North Sea environment in particular.• the contaminant programme in marine biota constitute an integrated part of the national monitoring activities in the marine environment as well as of the international programmes within ICES, OSPARCOM and HELCOM.The present report displays the timeseries of analysed contaminants in biota and summarises the results from the statistical treatment. It does not in general give the background or explanations to significant changes found in the timeseries. Increasing concentrations thus, urge for intensified studies.Short comments are given for temporal trends as well as for spatial variation and, for some contaminants, differences in geometric mean concentration between various species caught at the same site. Sometimes notes of seasonal variation and differences in concentration between tissues in the same species are given. This information could say something about the relative appropriateness of the sampled matrix and be of help in designing monitoring programmes. In the temporal trend part, an extract of the relevant findings is summarised in the 'conclusion'-paragraph. It should be stressed though, that geographical differences may not reflect antropogenic influence but may be due to factors like productivity, temperature, salinity etc.The report is continuously updated. The date of the latest update is reported at the beginning of each chapter. The creation date of each figure is written in the lower left corner.
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| 10. |
- Eriksson, Benjamin, 1992-
(författare)
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The evolution of TOFu : Developing and utilizing neutron time-of-flight spectrometry of deuterium and tritium fusion plasmas at JET
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Considerable effort has been invested in attempting to generate electricity from the energy released in controlled thermonuclear fusion reactions, with a European fusion research roadmap stretching beyond 2050. Our current endeavors may culminate in a virtually inexhaustible, low-carbon energy source for future generations. Experimental reactors such as the Joint European Torus (JET) and the International Thermonuclear Experimental Reactor (ITER) are stepping stones on the road to demonstrating the viability of fusion energy. Using various diagnostics and simulations, information on the plasma conditions in such experimental reactors can be obtained.In this thesis, the neutron time-of-flight spectrometer TOFOR at JET is used to study the neutron emission spectrum from the JET machine to determine different fusion plasma parameters. The first part of the thesis describes the efforts to upgrade the data acquisition (DAQ) system of TOFOR with a new, fully digital system: TOFu. Data reduction techniques are developed for the new DAQ system, and are shown to increase the signal-to-background ratio significantly. The instrumental response function is improved using the new system by measuring the energy-dependent time resolution and energy thresholds and applying them to the response function. Data analysis routines are developed to generate time-of-flight spectra from the data acquired by the 37 TOFOR sub-detectors.In the second part of the thesis, the data acquired by the new DAQ system is used to perform various physics studies of JET plasmas. We demonstrate the possibility of measuring the fuel ion temperature for Ohmic discharges of pure deuterium plasmas, with a precision that was unattainable with the former DAQ system. Furthermore, during the time of my doctoral studies, two deuterium-tritium experimental campaigns (DTE2 and DTE3) were conducted at JET. In order to contribute to the analysis of these experiments, we developed methods to measure the tritium fuel concentration in the fusion plasma using TOFOR. Also, experiments with pure tritium plasmas gave us the unique opportunity to measure the neutron emission spectrum from the T + T4He + 2n reaction during which we made the first observation in a magnetically confined plasma of the intermediate resonant reaction T + T5He + n.The analysis methods and experimental techniques developed in this thesis may be used in future neutron spectrometry systems, e.g., at ITER where there are plans to build a high-resolution neutron spectrometer (HRNS) consisting of several detection systems, one of which is a TOFOR-like time-of-flight spectrometer.
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