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  • 1.
    Ahmadkhaniha, D.
    et al.
    Jönköping University, Sweden.
    Eriksson, F.
    Linköping University, Sweden.
    Leisner, Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics. Jönköping University, Sweden.
    Zanella, C.
    Jönköping University, Sweden.
    Effect of SiC particle size and heat-treatment on microhardness and corrosion resistance of NiP electrodeposited coatings2018In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 769, p. 1080-1087Article in journal (Refereed)
    Abstract [en]

    Electrodeposition of NiP composite coatings with nano and sub-micron sized SiC has been carried out to investigate the possibility of replacing hard chromium coatings. The composition and structure of the coatings were evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. Microhardness was measured by Vickers indentation and polarization measurements were carried out to study the corrosion behavior of the coatings. The results showed that submicron particles can be codeposited with a higher content as compared to nano sized ones. However, even if a smaller amount of the nano-sized SiC particles are incorporated in the coating, the contribution to an increasing microhardness was comparable with the submicron sized particles, which can be related to the higher density of codeposited particles. SiC particles did not change the anodic polarization behavior of NiP coatings in a 3.5% NaCl solution. Finally, the effect of heat-treatment on the coatings properties at 400 °C for 1 h was studied to investigate the contribution of particles and heat-treatment on hardness and corrosion properties. It was found that the heat-treatment doubled the microhardness and changed the anodic polarization behavior of the coatings from passive to active with respect to the as-plated conditions.

  • 2.
    Ahmadkhaniha, Donya
    et al.
    Jönköping University, Sweden.
    Leisner, Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics. Jönköping University, Sweden.
    Zanella, Caterina
    Jönköping University, Sweden.
    Pinate, Santiago
    Jönköping University, Sweden.
    Electrodeposition of Ni high P composite coatings containing nano and submicron ceramic particles2017Conference paper (Refereed)
  • 3.
    Amon, Francine
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Gehandler, Jonatan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Assessment of the environmental impact of warehouse fires and fire service response2017In: Fire and Materials 2017: 15th International Conference, London, UK: Interscience Communications, 2017, p. 433-442Conference paper (Refereed)
  • 4.
    Anderson, Johan
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Boström, Lars
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Jansson McNamee, Robert
    Brandskyddslaget, Sweden.
    Fire Safety of Façades2017Report (Other academic)
    Abstract [en]

    Façade fires do not occur often (in comparison to other major structure fires) but in recent years there have been a number of spectacular façade fires in high rise building such as the recent fire in Grenfell Tower, London.Under-ventilated compartment fires may cause flames to spill out of window openings impinging the façade, thus devastating façade fires may start on one floor leap-frogging to adjacent floors. It is therefore necessary to limit or delay fire spread to higher floors. Requirements built on large scale fire testing may decrease the risk of these types of fires provided that the building is constructed according to the specifications provided by the manufacturer. Different countries have different regulations and tests for façades. New materials and façade systems are continuously introduced which might call for an update of these tests and regulations.This report summarizes experimental and modelling efforts in characterizing the fire safety of façades using the Swedish SP Fire 105 and the British BS 8414 methods. Recent experimental results and modelling is presented exploring the variations in the fire exposure, fire load and the fuel used. The fire source and the heat exposure to the façade are characterized by additional temperatures measured by plate thermometers while some other aspects are only treated in the numerical study such as a change in fuel. It is found that the results from the BS 8414 are largely affected by wind and climate since the experimental test was performed outdoors, moreover fire spread on wooden façades is also briefly discussed.In order to obtain a deeper understanding of the test methods and the results CFD (Computational Fluid Dynamics) Modelling in FDS was used. The models were based on measured input parameters including uncertainties and an assessment of the impact of said uncertainties. The models could often reproduce the experimentally found temperatures qualitatively and quantitatively. A detailed discussion on the regulations and the tests that lead to the SP Fire 105 test method is also presented. Summaries of the façade testing methods and conditions in other European countries are presented in the appendices.Finally possible ways forward in updating the façade testing and regulations are discussed.

  • 5.
    Anderson, Johan
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Boström, Lars
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Jansson McNamee, Robert
    Brandskyddslaget, Sweden.
    Milovanović, Bojan
    University of Zagreb, Croatia.
    Experimental comparisons in façade fire testing considering SP Fire 105 and the BS 8414‐12018In: Fire and Materials, ISSN 0308-0501, E-ISSN 1099-1018, Vol. 42, no 5Article in journal (Refereed)
    Abstract [en]

    A comparison between full‐scale façade fire tests where SP Fire 105 and BS 8414‐1 were used regarding repeatability and the use of modeling to discern changes in the setups is presented. Two test series according to BS 8414‐1 were repeated outside using the same façade systems on 2 different days, whereas for the SP Fire 105 a set of common façade systems in Sweden were tested indoors. In particular, the results show that the wind around the test setup may have a significant impact on the tests and that the heat exposure to the façade surface will depend on the thickness of the test specimen where an increased temperature in front of the façade, and a decreased temperature on the façade 2.1 m above the fire room, is observed experimentally. The heat exposure to the test specimen varies to a more limited extent when an uncontrollable free burning fire source is used (in this study heptane and wood, respectively) and that this variation increases when wind is present.

  • 6.
    Anderson, Johan
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Boström, Lars
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Jansson McNamee, Robert
    Brandskyddslaget AB, Sweden.
    Milovanović, Bojan
    University of Zagreb, Croatia.
    Modeling of fire exposure in facade fire testing2017In: Fire and Materials, ISSN 0308-0501, E-ISSN 1099-1018, Vol. 42, no 5, p. 475-483Article in journal (Refereed)
    Abstract [en]

    In this paper, a comparative simulation study on 3 large‐scale facade testing methods, namely,the SP Fire 105, BS 8414‐1, and the ISO 13785‐2 methods, is presented. Generally goodcorrespondence between simulations and experimental data has been found, provided thatthermal properties of the facade material and heat release rates are known; however, thecorrespondence deviates in close proximity of the fire source. Furthermore, a statistical ensemblefor evaluating the effects stemming from uncertainty in input data is used. Here, it wasfound using this statistical ensemble that the variability was smaller in the ISO 13785‐2compared to the BS 8414‐1 method. The heat release rates (HRR) used in the simulations wereadopted from measurements except for the ISO method where the information in the standardwas used to approximate the HRR. A quantitative similarity between the HRR in the ISOmethod and the British method was found.

  • 7.
    Anderson, Johan
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport.
    Sjöström, Johan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Lönnermark, Anders
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Persson, Henry
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Larsson, Ida
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Assessment of Self-Heating in Wood Pellets by FE Modelling2017Conference paper (Refereed)
    Abstract [en]

    The self-heating process in a laboratory scale experiment has been modelled using the Comsol Multiphysics software. In the simulations the gas flow and air movement in the volume and heat diffusion in the bulk were taken into account however only one reaction in the pellets bulk is considered. The input data is found from measurements of the reaction chemistry and the heat transfer properties. It is found that all relevant physics is needed in order to obtain reasonable predictions in particular the heat transfer between the bulk and the gas is important but also condensation and evaporation of moisture.   

  • 8. Andersson, Anders
    et al.
    Holmsten, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Mätteknik för processindustrin2017 (ed. 5)Book (Other academic)
    Abstract [sv]

    Hur varmt är det i tanken? Vilket tryck ger pumpen? Det är två exempel på frågor som kan besvaras med processmätteknik.Att mäta är att veta, sägs det, men det gäller ocksåatt veta hur bra man mäter! Felaktiga mätresultat skaparproblem, osäkerhet och kan rent av vara farliga.I den här boken får du hjälp att undvika mätfel, du fårlära dig om olika mätprinciper och hur mätare av olika slagbäst används och monteras. Främst handlar det om temperatur,tryck, flöde och nivå men även annat som finns i enprocessindustri. Du får kunskap om kalibrering, spårbarhetoch mätosäkerhet, och samtidigt om saker runt omkringmätinstrumenten, till exempel CE-märkning, elstörningar,explosionsskydd, skrivregler, signalöverföring, standardermed mera

    Innehållsförteckning:  1: Mätteknik 2: Lästips – Gör så här 3: Mått i historien 4: CE-märkning 5: SI-systemet 6 :Signalöverföring 7: Säkerhet 8: Mätosäkerhet A 9: Fysik och matematik 10: Mättekniska begrepp 11: Temperaturmätning 12: Tryckmätning 13: Flödesmätning 14:Nivåmätning 15: Värmemätning 16: Vakter och larm 17:Serviceinstrument 18:Konduktivitetsmätning 19: pH-mätning 20: Densitetsmätning 21: Vägning 22: Fuktmätning 23: Mätosäkerhet B 24: Kalibrering 25: Pumpar och ventiler 26: Rörledningar 27: Mätosäkerhet C 28: Tabeller 29:Index

  • 9.
    Andersson, Bengt-Olof
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Eklund, Gunnar
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Bergsten, Tobias
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Calibration of Gain Ratios on nV-Meters with the Reference Step Method2018In: CPEM 2018 - Conference on Precision Electromagnetic Measurements, 2018Conference paper (Refereed)
    Abstract [en]

    The Reference Step Method for calibrators can be modified for calibration also of the gain ratios on a meter. The method has earlier been evaluated in the range 100 mV-1000 V on DMM HP 3458A1 and shows that an accuracy of typically < ± 0.2 μ V/V could be obtained. We have investigated the performance of the method when calibrating ratios in the range 1 mV-100 mV on two common nV-meters. In our comparisons with the Josephson Voltage Standard the differences are within ± ± 12μ V/V at the ratio 10m V:1mV and within ± ± 1.3μ V/V at 100mV:10mV.

  • 10.
    Andersson, Petra
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Aras, Silvia
    Lunds University, Sweden.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Frantzich, Håkan
    Lunds University, Sweden.
    Larsson, Ida
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Vermina Lundström, Frida
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Nilsson, Daniel
    Lunds University, Sweden.
    Runefors, Marcus
    Lunds University, Sweden.
    Riskreducerande åtgärder för dödsbränder i bostäder2018Report (Other academic)
    Abstract [en]

    Thisreport summarizes the work conducted within the project ”Analysis of physicaldeterminants and technical measures in support of the zero vision” financed bythe Civil Contingency Authority (MSB) in Sweden. The work aims to find measuresto prevent and reduce the number of fatalities in fires in residentialbuildings in a Sweden, a list of such measures is provided in the end of thereport. The list is based on work conducted in several small sub-projects, ashort summary of these is also provided in the report.

  • 11.
    Andersson, Petra
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Evegren, Franz
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Jandali, Mourhaf
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Larsson, Fredrik
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Rosengren, Max
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Lion Fire: Extinguishment and mitigation of fires in Li-ion batteries at sea2018Report (Other academic)
    Abstract [en]

    The shipping industry is facing increasing pressure to cut emissions. Diesel-electric hybrid or fully electrical propulsion systems can offer significant savings in fuel consumption and reduce emissions. However, the use of energy storage battery systems on board vessels is introducing new fire hazards and advice on suitable fire extinguishing systems and agents is desired. In a series of tests, both total compartment application water spray and water mist systems and direct injection (using several different agents) into the module were evaluated in fire tests conducted to compare different fire extinguishing approaches for a fire in a battery cell. A test compartment was constructed to simulate a battery room and a commercially available lithium-ion (Li-ion) battery cell was positioned inside a cubic box that mimicked a battery module. By heating the battery cell, combustible gases were generated, and these gases were ignited by a pilot flame inside the simulated battery module. The tests indicated that fire extinguishment of a battery cell fire inside a battery module is unlikely when using total compartment water spray or water mist fire protection systems. The water droplets are simply not able to penetrate the battery module and reach to the seat of the fire. Direct injection of the fire extinguishing agent inside the battery module is necessary. The tests also showed that agents such as water and low-expansion foam, with a high heat capacity, provide rapid cooling and fire extinguishment. The reduced water surface tension associated with low-expansion foam may improve the possibilities for water penetration whilst agents with a high viscosity may not be able to spread to the seat of the fire. Agents with less heat capacity, such as high-expansion foam and nitrogen gas, provide less cooling but fire extinguishment can still be achieved if designed correctly.

  • 12.
    Andersson, Petra
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Sundström, BjörnRISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Proceedings from 4th International Conference on Fires in Vehicles - FIVE 2016, October 5-6, 2016 Baltimore, USA2016Conference proceedings (editor) (Other academic)
  • 13.
    Andersson, Petra
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Wikman, Johan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Larsson, Fredrik
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Willstrand, Ola
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Safe introduction of battery propulsion at sea2017Report (Other academic)
    Abstract [en]

    Electric propulsion using batteries as energy storage has the potential to significantly reduce emissions from shipping and thus the environmental impact. The battery type that is currently on the top of the agenda to be used for ship propulsion applications is Li-ion batteries. Li-ion batteries pose different safety issues than e.g. other propulsion technologies and other batteries such as lead-acid batteries. It is essential that the safety level on board, including fire safety, is maintained, when introducing electric propulsion with energy storage in batteries. This report discusses the different regulations and guidelines available today for fire safety of batteries on board in relation to current knowledge about Li-ion batteries. Also fire safety measures available on board ships today and their applicability for Li-ion batteries is discussed, as well as the different test methods available and their applicability. A workshop gathering different stakeholders from Sweden, Norway and Finland identified fire safety as the main challenge for the introduction of battery propulsion at sea. The workshop concluded that future work is desired in order to increase knowledge and to develop publicly available strategies, training and designs.

  • 14.
    Andrea, Anders
    et al.
    Huawei Technologies Sweden AB, Sweden.
    Anderson, Johan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Manzetti, Sergio
    Fjordforsk AS, Norway.
    A theoretical hypothesis of beverage cooling by reverse heating inconsumer microwave ovens by using fullerenol (polyhydroxylatedfullerenes) dissolved in acetone2018In: International Journal of Applied Physics, ISSN 2367-9034, Vol. 3Article in journal (Refereed)
    Abstract [en]

    Cooling of beverages is of large interest. Here a theoretical idea of how microwave ovens can be usedfor cooling beverages is presented. The proposed theoretical idea based on heat transfer features a microwavesafe (isoprene rubber) torus shaped rubber ring (MWSR) holding a liquid (L) at room temperature. Fullerenoldissolved in acetone (L) inside MWSR (L) will absorb energy directly from the microwave radiation and therebyincrease its temperature. The liquid to be cooled (B) will also absorb energy from the microwave radiation, butthe net effect is the cooling of B as the heat transfer is faster in L than in B due to L’s lower boiling point andheat of vaporization. The cooling fan of the microwave oven facilitates the heat transfer mechanism. Thebeverage B is theoretically cooled from room temperature (20 °C) to around 4 °C in around 58 seconds. Basedon heat absorption of fullerenol—which could be transformed from liquid phase to vapour phase—a beverageliquid (300 g water) in a glass put inside the microwave oven could be cooled (reversely heated) by the heatgenerated by the microwave oven. The user of the proposed method would be able cool 300 ml of beverage toless than 4 °C in just a minute using consumer microwave ovens.

  • 15.
    Arrhenius, Karine
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Karlsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Hakonen, Aron
    Ohlson, Lars
    Fordonsgas Sverige AB, Sweden.
    Yaghooby, Haleh
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Büker, Oliver
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Variations of fuel composition during storage at Liquefied Natural Gas refuelling stations2018In: Journal of Natural Gas Science and Engineering, ISSN 1875-5100, E-ISSN 2212-3865, Vol. 49, p. 317-323Article in journal (Refereed)
    Abstract [en]

    Liquefied Natural Gas (LNG) and Liquefied Biogas (LBG) utilization within the heavy duty transport sector is today a sustainable alternative to the use of oil. However, in spite of the high degree of insulation in the storage tank walls, it is impossible to fully avoid any net heat input from the surroundings. Due to some degree of vaporization this results in variation in gas composition during storage at refuelling stations, potentially leading to engine failures. Within this study, a vaporizer/sampler has been built and tested at a station delivering liquefied biomethane (LBG) and occasionally; such in this case, LNG to heavy and medium duty trucks. The vaporizer/sampler has then been used to study the variation of the LNG composition in the storage tank during a two weeks period. The results clearly underline a correlation between the gas phase and the liquid phase as the concentration changes follow the same trend in both phases. Two opposite effects are assumed to influence the concentration of methane, ethane and propane in the liquid and in the gas phase. On one hand, because of the probable presence of not fully mixed layers in the storage tank and due to vehicles being refuelled, both liquid and gas phases are enriched in methane at the expense of ethane and propane. On the other hand, due to boil-off effect towards the end of the storage period, both liquid and gas phases are enriched in ethane and propane at the expense of methane.

  • 16.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport.
    An evaluation of residential sprinklers and water mist nozzles in a residential area fire scenario2017Report (Other academic)
    Abstract [en]

    Commercial residential sprinklers are usually fitted with 3 mm glass bulbs having a nominal operating temperature of 68°C or a high-sensitivity solder link, usually with a nominal temperature rating of 74°C. Previous work show that there is a significant potential for improving sprinkler response times in a residential room fire scenario by using glass bulbs with a lower Response Time Index (RTI) and lower operating temperature than commonly used. The objective of this study was to investigate any improved performance due to earlier activation of residential sprinklers. A series of fire tests was conducted inside a test compartment sized 3.66 m by 3.66 m. The fire test source consisted of either a simulated or authentic upholstered chair. For the majority of the tests, the flow rate of the residential sprinkler was 30.3 liter/min (corresponding to the minimum design density 2.05 mm/min as per the recommendations in NFPA 13D and 13R). Additional tests were conducted at 60.6 liter/min (the minimum design density 4.1 mm/min as per NFPA 13). Tests were also conducted with commercial low- and high-pressure water mist nozzles and a stand-alone high-pressure water mist system.

    The results show that earlier activation of residential sprinklers had a small effect on its performance, especially for the authentic upholstered chair scenario, when flowing 30.3 liter/min. The rather small effect is probably due to that the discharge density was too low to provide fire suppression. When the flow rate was increased to 60.6 liter/min, the performance was considerably improved as compared to the flow of 30.3 liter/min. Any improvement in performance of earlier activation was, however, not investigated for the 60.6 liter/min flow rate.

    The flow rates of the commercial low- and high-pressure water mist water mist nozzles ranged from 17.2 liter/min to 36.7 liter/min. Roughly, it could be concluded that the performance of the water mist nozzles were comparable or better than the residential sprinkler at approximately half the water flow rate for the tested fire scenarios.

    The stand-alone high-pressure water mist system had a flow rate of 8.2 liter/min. The performance was comparable to that of the other water mist nozzles in the study The performance was comparable to that of the other water mist nozzles in the study, despite a considerably earlier activation. However, the results indicate that the performance was relatively much influenced whether the simulated upholstered chair was orientated with its front towards the test compartment or with its front towards the back wall (poorer performance). This would suggest that the position of the fire test relative to the position of the unit is a crucial factor and underlines the importance of a thoughtful positioning in practical applications.

  • 17.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Brandförsök med boendesprinkler och vattendimma2017Conference paper (Other (popular science, discussion, etc.))
  • 18.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Funktionskontroll av sprinkler – erfarenheter från uppdrag 2013-20162017Conference paper (Other (popular science, discussion, etc.))
  • 19.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    The Response Time of Different SprinklerGlass Bulbs in a Residential Room FireScenario2018In: Fire technology, ISSN 0015-2684, E-ISSN 1572-8099, Vol. 54, no 5, p. 1265-1282Article in journal (Refereed)
    Abstract [en]

    The response time of fire sprinklers is essential for their performance,especially in applications where life safety protection is desired. The earlier the sprin-kler activates, the smaller the size of the fire. Most commercial residential sprinklersare fitted with 3 mm, 68C glass bulbs. However, thinner sprinkler glass bulbs withlower operating temperatures are available. The aim of this study was to determinethe response time—and the corresponding heat release rate—of different glass bulbsin a residential room fire scenario. A series of tests were conducted inside a compart-ment measuring 3.66 m by 3.66 m having a ceiling height of 2.5 m. The compartmentwas either enclosed or had two walls removed to provide a more ventilated scenario.A propane gas burner was positioned at one of the corners. The mass flow rate ofthe gas was controlled such that either ‘slow’, ‘medium’ or ‘fast’ fire growth rate sce-narios were simulated. In each test, nine Response Time Index (RTI) and operatingtemperature combinations were tested. Each test was replicated three times. In addi-tion, two commercial fire detectors were tested. The results show that the fire is con-siderably smaller upon activation with a combination of a low RTI and a lowoperating temperature, as compared to the 3 mm, 68C glass bulb typically used forresidential sprinklers. The operating temperature proved to have a larger impact onthe results than the RTI. The heat from the fire was typically detected by the firedetectors prior to the activation of the sprinkler glass bulbs, especially for the ‘slow’and ‘medium’ fire growth rate scenarios.

  • 20.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Val av släcksystem: Värdering av brandscenarier, skyddsmål och släcksystem2017Conference paper (Other (popular science, discussion, etc.))
  • 21.
    Arvidson, Magnus
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport.
    Vylund, Lotta
    RISE - Research Institutes of Sweden, Safety and Transport.
    Water distribution tests using Extended Coverage sprinklers for the Muskö Tunnel2017Report (Other academic)
    Abstract [en]

    The objective of the tests was to determine the water distribution characteristics using different water pressures and sprinkler spacing of two selected Extended Coverage sprinklers. The sprinklers may be used for the protection of the Muskö tunnel and the test set‑up simulated a freight truck trailer positioned inside the tunnel.

    Adequate sprinkler coverage would require that sprinklers are positioned close to the peak of the ceiling. A relatively short vertical distance from the sprinklers and the ceiling is also essential for proper thermal activation. These requirements are best met by the use of upright sprinklers. Two extended coverage upright sprinklers with a K‑factor of 363 (metric) and 202 was selected for the tests.

    For the extended coverage upright K363 sprinkler (Tyco model EC‑25), a sprinkler spacing of 4.0 m is recommended, in order to account for the fact that full coverage of the freight truck trailer was not achieved at the tested 4.2 m spacing. A density of 10 mm/min requires an operating pressure of around 0.7 bar at this particular spacing.

    The tested extended coverage upright K202 sprinkler (Tyco model EC‑14) provided a wider water discharge pattern, with a proper water distribution on the top of a freight truck trailer positioned offset in the tunnel at sprinkler spacing up to 5.0 m. For an actual installation, a K202 sprinkler designed for a density of 10 mm/min require an operating pressure of around 3.6 bar at this particular spacing.

  • 22.
    Bedon, Chiara
    et al.
    University of Trieste, Italy.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Kozłowski, Marcin
    Silesian University of Technology, Poland; Lund University, Sweden.
    Numerical Modelling of Structural Glass Elements under Thermal Exposure2018Conference paper (Refereed)
    Abstract [en]

    Glass is largely used in engineering applications as a structural material, especially for laminated glass (LG) sections. However, the well-known temperature-dependent behaviour of visco-elastic interlayers for LG sections should be properly accounted for safety purposes, even in ambient conditions. The materials thermo-mechanical degradation with increase of temperature could further severely affect the load-bearing performance of such assemblies. Thermo-mechanical Finite Element (FE) numerical modelling, in this regard, can represent a robust tool and support for designers. Key input parameters and possible limits in FE models, however, should be properly taken into account and calibrated, especially for geometrically simplified models, to enable realistic and reliable estimations of real structural behavior. In this paper, FE simulations are proposed for monolithic (MG) and LG specimens under radiant heating, based on one-dimensional (1D) models. With the use of experimental results from the literature, parametric studies are discussed, indicating limits and issues at several modelling assuptions. Careful consideration is paid for various thermal material properties (conductivity, specific heat), boundary conditions (conductivity, emissivity) as well as geometrical features (thickness tolerances, etc.) and composition of LG sections (interlayer type, thickness). Comparative parametric results are hence discussed in the paper.

  • 23.
    Bedon, Chiara
    et al.
    University of Trieste, Italy.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Kozłowski, Marcin
    Silesian University of Technology, Poland; Lund University, Sweden.
    Eliášová, Martina
    Czech Technical University in Prague, Czech Republic.
    Vokáč Machalická, Klára
    Czech Technical University in Prague, Czech Republic.
    Vokáč, Miroslav
    Czech Technical University in Prague, Czech Republic.
    Santos, Filipe
    NOVA University Lisbon, Portugal.
    Wüest, Thomas
    Lucerne University of Applied Sciences and Arts, Switzerland.
    An insight on possible classification and metrics, experimental testing and numerical modelling for adaptive facades: Activity report from the ‘Structural’ Task Group2018In: Proceedings of the COST Action TU1403 Adaptive Facades Network Final Conference, 2018, p. 325-336Conference paper (Refereed)
  • 24.
    Bedon, Chiara
    et al.
    University of Trieste, Italy.
    Kozłowski, Marcin
    Lund University, Sweden; Silesian University of Technology, Poland .
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Thermal assessment of glass façade panels under radiant heating: Experimental and preliminary numerical studies2018In: Journal of Facade Design and Engineering, ISSN 2213-302X, Vol. 6, no 3, p. 049-064Article in journal (Refereed)
    Abstract [en]

    Nowadays, glass is increasingly being used as a load-bearing material for structural components in buildings and façades. Different structural member solutions (such as panels, beams, columns) and loading conditions were the subjects of several research studies in recent years. Most of them, however, were typically limited to experimental testing and numerical simulations on glass elements and assemblies at room temperature. Thermo-mechanical investigations, inclusive of the temperature-dependent behaviour of visco-elastic interlayers used in laminated glass solutions, as well as the typical thermo-mechanical degradation of glass properties in line with temperature increase, in this regard, are still limited. Such an aspect can be particularly important for adaptive façades, in which the continuous variation of thermal and mechanical boundary conditions should be properly taken into account at all the design stages, as well as during the lifetime of a constructed facility. Given the key role that thermo-mechanical studies of glazing systems can pe use of glass in façades, this paper focuses on Finite Element (FE) numerical modelling of monolithic and laminated glass panels exposed to radiant heating, by taking advantage of past experimental investigations. In the study discussed herein, being representative of some major outcomes of a more extended research project, one-dimensional (1D) FE models are used to reproduce the thermal behaviour of selected glass specimens under radiant heating, as observed in the past experiments. Given the high computational efficiency but very basic assumptions of 1D assemblies, a critical discussion of experimental-to-numerical comparisons is then proposed for a selection of specimens.

  • 25.
    Bedon, Chiara
    et al.
    University of Trieste, Italy.
    Zhang, Xidong
    Curtin University, Australia.
    Santos, Filipe
    NOVA University Lisbon, Portugal.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Kozłowski, Marcin
    Silesian University of Technology, Poland; Lund University, Sweden.
    Arrigoni, Michel
    ENSTA Bretagne, France.
    Figuli, Lucia
    University of Žilina, Slovakia.
    Lange, David
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Performance of structural glass facades under extreme loads – Design methods, existing research, current issues and trends2018In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 163, p. 921-937Article in journal (Refereed)
    Abstract [en]

    Glass has been overwhelmingly used for windows and facades in modern constructions, for many practical reasons, including thermal, energy, light and aesthetics. Nevertheless, due to the relatively low tensile strength and mostly brittle behaviour of glass, compared to other traditional materials, as well as to a multitude of interacting structural and non-structural components, windows/facades are one of the most fragile and vulnerable components of buildings, being representative of the physical line of separation between interior and exterior spaces. As such, multidisciplinary approaches, as well as specific fail-safe design criteria and analysis methods are required, especially under extreme loading conditions, so that casualties and injuries in the event of failure could be avoided and appropriate safety levels could be guaranteed. In this context, this paper presents a review of the state of art on analysis and design methods in use for glass facades, with careful consideration for extreme loading configurations, including natural events, such as seismic events, extreme wind or other climatic exposures, and man-made threats, i.e. blast loads and fire. Major results of available experimental outcomes, current issues and trends are also reported, summarising still open challenges.

  • 26.
    Belov, Ilia
    et al.
    Jönköping University, Sweden.
    Nordh, Andreas
    Zigrid AB, Sweden.
    Salomonsson, Kent
    Jönköping University, Sweden.
    Leisner, Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics. Jönköping University, Sweden.
    Fin‐Tube and Plate Heat Exchangers – Evaluation ofTransient Performance2017Conference paper (Refereed)
  • 27.
    Belov, Ilja
    et al.
    Jönköping University, Sweden.
    Alavizadeh, Zahra
    Jönköping University, Sweden.
    Lindgren, Mats
    Omnisys Instruments AB, Sweden.
    Rydén, Jan
    Saab AB, Sweden.
    Leisner, Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Experimental and CFD evaluation of active anti-condensation methods for non-hermetic cabinets2018In: 2018 19th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE), 2018, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Experimental evaluation of several active anti-condensation methods for application in non-hermetic electronics enclosures was performed in harsh climatic conditions, including RH = 70% and T = 43 °C. The studied methods included blowing the air along the exposed surface, combination of blowing and air heating as well as local heating of the exposed surface in natural convection conditions. The purpose was to prevent/remove the dew on/from the exposed surface of a micro-condensation sensor. The difference between the methods was quantified in terms of time for dew removal. The power consumption aspects were discussed. A CFD based optimization methodology was developed to determine the heating profiles for the local anti-condensation PCB heater in a non-hermetic cabinet exposed to the quickly changing climatic conditions. The potential for 60% energy savings was revealed by simulation.

  • 28.
    Belov, Vladimir
    et al.
    Ogarev Mordovia State University, Russia.
    Leisner, Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Mannikoff, Anders
    Herrljunga Elektriska AB, Sweden.
    Belov, Ilja
    Jönköping University, Sweden.
    Mathematical Model of Multi-Phase Power Converter for Parallel Computation2018In: International Journal of Emerging Electric Power Systems, ISSN 2194-5756, E-ISSN 1553-779X, article id 20170114Article in journal (Refereed)
    Abstract [en]

    A mathematical model of a multi-phase power conversion system composed of modified bridge-elements (B-system) capable for parallel computation has been developed. Experimental validation on the example of a power system including a synchronous generator and an AC-DC rectifier has been performed. A mathematical algorithm for B-system assembly and steps to obtain mathematical model of the B-system have been developed. Integration of mathematical models of conversion system into the complete model of a multi-phase power system has been explained and evaluation of computational efficiency of parallel computation techniques for the developed model of an AC-DC-AC converter has been performed. The presented modelling method can be employed in the design phase of smart grids, for power quality and conducted emission analysis.

  • 29.
    Benavente, Fabian
    et al.
    KTH Royal Institute of Technology, Sweden.
    Lundblad, Anders Olof
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Campana, Pietro
    Mälardalen University, Sweden.
    Zhang, Yang
    KTH Royal Institute of Technology, Sweden.
    Cabrera, Saul
    UMSA Universidad Mayor de San Andrés, Bolivia.
    Lindbergh, Göran
    KTH Royal Institute of Technology, Sweden.
    Photovoltaic/battery system sizing for rural electrification in Bolivia: Considering the suppressed demand effect2019In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 235, p. 519-528Article in journal (Refereed)
    Abstract [en]

    Rural electrification programs usually do not consider the impact that the increment of demand has on the reliability of off-grid photovoltaic (PV)/battery systems. Based on meteorological data and electricity consumption profiles from the highlands of Bolivian Altiplano, this paper presents a modelling and simulation framework for analysing the performance and reliability of such systems. Reliability, as loss of power supply probability (LPSP), and cost were calculated using simulated PV power output and battery state of charge profiles. The effect of increasing the suppressed demand (SD) by 20% and 50% was studied to determine how reliable and resilient the system designs are. Simulations were performed for three rural application scenarios: a household, a school, and a health centre. Results for the household and school scenarios indicate that, to overcome the SD effect, it is more cost-effective to increase the PV power rather than to increase the battery capacity. However, with an increased PV-size, the battery ageing rate would be higher since the cycles are performed at high state of charge (SOC). For the health centre application, on the other hand, an increase in battery capacity prevents the risk of electricity blackouts while increasing the energy reliability of the system. These results provide important insights for the application design of off-grid PV-battery systems in rural electrification projects, enabling a more efficient and reliable source of electricity.

  • 30.
    Bergman, Anders
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Absolute calibration of a 100 KV DC divider1996Conference paper (Refereed)
    Abstract [en]

    An absolute determination of the ratio of a 100 kV DC divider has been made. A new Zener device that has recently become available has been used in a step-up mode to obtain the divider ratio. The uncertainty of the determination is 5.5 ppm.

  • 31.
    Bergman, Anders
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Achievable Accuracy in Industrial Measurement of Dissipation Factor of Power Capacitors2018In: NCSLI Measure, ISSN 1931-5775, Vol. 12, no 1, p. 34-41Article in journal (Refereed)
    Abstract [en]

    Modern dielectrics used in power capacitors can exhibit a dissipation factor lower than 0.005 %, which approaches the limits of presently available measurement techniques. This article reviews techniques, apparatus, and available calibration services for dissipation factor with regard to lowest achievable uncertainties. It is shown that further metrological advances are necessary to lower uncertainty in the measurement to levels at least five times less than presently achievable, in order to ensure traceable and quality-assured measurement of modern dielectrics with such low dissipation factors

  • 32.
    Bergman, Anders
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Influence of coaxial cable on response of high-voltage resisitive dividers2017Conference paper (Refereed)
    Abstract [en]

    An effort is pursued by several European National Measurement Institutes to lower the uncertainties in calibration of UHV measuring systems for lightning impulse. To this end, several reference dividers are investigated as regards their accuracy both for amplitude and for time parameters. During these investigations a deterioration of step response was identified when longer coaxial cables were inserted in the measuring circuit. The measured front time T1 was also affected, in one observed case by 2.5 % elongation of front time as another 25 m cable was inserted. Compared to the intention to calibrate front time measurement to better than 5 % uncertainty for front time, this contribution must be well known, or preferably be eliminated. This paper presents the experimental findings from these investigations. The investigated cables included selected coaxial, tri-axial, and cables with a corrugated screen. The effect of cable length was also studied. The influence was first discovered when applying a very fast step (rise-time < 4 ns) to the high voltage arm of a resistive divider and convolution of this step with the time derivative of an ideal lightning impulse with 0.84/60 µs impulse. The calculated output was analysed with IEC 61083 compliant software to evaluate the front time. Subsequently, these analyses have been augmented by additional comparative measurements where two reference dividers were connected to the same impulse generator, and varying the cable length of one of them. The summarized changes in front time calculated for different combinations of cable and impulse voltage dividers are shown and discussed. It is noted that a change in T1 error depends both on length of cable and its type. The results show that non-negligible front time errors may be introduced when the cable length is increased. To support these findings, further tests have been carried out with two reference impulse dividers connected in standard calibration configuration in accordance with IEC 60060-2. One divider was used as reference, while the cable for the other was varied. In this way, the change of error between configurations could be measured. A theoretical study has also been performed, calculating the distortion of a lightning impulse on a coaxial cable. The results agree qualitatively with experiments, but the detailed results show discrepancies that need further investigation.

  • 33.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Bergman, Sixten
    Consultant, Rönnvägen 1 A, 507 71 Gånghester, Sweden.
    Hoffmann, Christian
    Baur Gmbh, 6832 Sulz, Austria.
    Paulus, Eberhard
    Baur Gmbh, 6832 Sulz, Austria.
    Elg, Alf-Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Traceable measurement of dielectric dissipation factor at Very Low Frequency2013Conference paper (Refereed)
    Abstract [en]

    Very Low Frequency (VLF) tests are often used for after-laying tests of power cables since the reactive power demand is much lower at VLF than at 50 Hz. In order to augment the usefulness of the test, it is often complemented by a measurement of dielectric dissipation factor (tan ), where the acceptance of the tested object is based on this measurement. A traceability chain for dissipation factor at high voltage and very low frequency has as yet not been recognized by the International Bureau of Weights and Measures (BIPM), which results in difficulties to prove the quality of the measurement. The measurement is complicated by the limited range of the current in the test object that can be resolved by available high voltage test equipment, thus limiting the possible choices of reference systems. A novel reference measuring system that can fulfil these needs has been developed at SP Technical Research Institute of Sweden in the capacity as National Measurement Institute. The traceability of the system to National Standards of Measurement is ensured by careful scientific work and analyses. This measuring system has the ability to measure dissipation factor at 0.1 Hz in the voltage range from 0.5 kV up to 50 kV with an uncertainty better than 0.004 %.

  • 34.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Elg, Alf-Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Hällström, Jari
    VTT-MIKES, Finland.
    Evaluation of step response of transient recorders for lightning impulse2017Conference paper (Refereed)
    Abstract [en]

    High voltage equipment will be subjected to several types of electrical stress during operation. A battery of factory tests is defined to ensure that the equipment will perform satisfactorily in service. One of the crucial tests is to apply a simulated lighting impulse as standardised to a double-exponential impulse with at front time of 1.2 µs (± 30 %) and a time to half value of 50 µs (± 20 %). Although this wave-shape only approximates natural lightning, there is a solid body of experience within industry, proving that reliability of equipment in service is adequately proven by the standard waveform. It is however crucial for consistency of results that the both voltage level and wave-shape are correctly measured. This paper discusses the requirements and performance of the recording instruments used, leaving the properties of high voltage impulse dividers outside the discussion. The requirements for the recording instrument – transient recorder – are given in IEC 61083-1. The standard provides requirements for, and/or tests to verify, that the recorder has moderately fast response, fast settling time, high resolution, linearity under dynamic conditions, high accuracy and reasonably low internal noise. This is partly in contrast to major trends in transient recorder development, where fast sampling and fast step response are prioritized ahead of high accuracy and fast settling without creeping response. We have therefore evaluated several commercially available recorders in order to find one with respectively flat and reasonably fast step response. In this campaign, a proprietary step generator based on the use of a mercury reed relay has been used. Evaluation of this device is submitted to ISH 2017. It has been found that the measured flatness of the step response directly after the step is a good first indicator of the performance of the transient recorder. This is identified in IEC 61083-1 clauses 1.5.2 and 1.5.3, as a requirement on stability of the recorded step from 0.5 T1min to T2max. For lightning impulse this means from 0.42 µs to 60 µs. For approved transient recorders the requirement is to be within 1 %. For reference transient recorders, a limit of not more than 0.5 % should be applied. Further proof of the accuracy of the transient recorder can be achieved by convolution of an ideal waveform with the recorded step response and analysing the resulting curve with lightning impulse parameter software. A third possibility is to make direct calibration of the transient recorder, using a calculable impulse calibrator. Several state-of-art transient recorders have been evaluated and the results show that only a few are suited for measurement of lightning impulse. Also, the variation of the performance between the ranges and channels of one instruments are significantly large. Both direct assessment of step response as well as result of convolution with a theoretical 0.84/50 µs impulse will be reported. The agreement with results obtained with a calculable impulse calibrator will be illustrated.

  • 35.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Nordlund, Mathias
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Characterisationat low voltage of two reference lightning impulse dividers2017Conference paper (Refereed)
    Abstract [en]

    An effort is pursued by several European National Measurement Institutes to lower the uncertainties in calibration of UHV measuring systems for lighting impulse. To this end, several reference dividers are investigated as regards their accuracy both for amplitude and for time parameters. At SP - RISE Research Institutes of Sweden, a 500 kV resistive reference divider has been in use since 2000. Additionally an 800 kV resistive divider is investigated as a possible reference divider for UHV lightning impulse measuring systems. The best uncertainty for the 500 kV reference measuring system is 1 % for voltage amplitude and 3 % for time parameters. The present work aims at lowering these uncertainties by means of better characterisation and evaluation of the possibilities to apply corrections for known errors. The scale factor and dynamic behaviour of a resistive divider can be conveniently determined at low voltage and frequency. Further experiments such as linearity tests and augmented by scientific work is needed to ascertain the performance at high voltage. Step response plays a major role in the characterisation of dividers, and in this work much effort has gone into gathering step responses and evaluating them for various circuit layouts to characterise the variation of the step response due to circuit dimensions and diverse proximity effects. The step applied to the divider is generated by a mercury wetted relay based step generator with an output voltage of 200 V. The step rise-time is a few ns, and thus appreciably faster than the response of the divider. Apart from inspection of the step response itself, evaluation of measurement errors is performed by convolving an ideal curve with the step response of the divider, including its transmission cable. The convolved signal is evaluated with impulse evaluation software and the parameters compared to the ideal input. The difference is a measure of the errors introduced by the divider. This procedure follows IEC 60060-2: 2010.

  • 36.
    Bergman, Anders
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Nordlund, Mathias
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Elg, Alf-Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Meisner, Johann
    Physikalisch-Technische Bundesanstalt PTB, Germany.
    Passon, Stephan
    Physikalisch-Technische Bundesanstalt PTB, Germany.
    Hällström, Jari
    VTT-MIKES, Finland.
    Lehtonen, Tapio
    VTT-MIKES, Finland.
    Characterization of a fast step generator2017Conference paper (Refereed)
    Abstract [en]

    Lighting impulse measurements are made as a matter of routine in high voltage testing of high-voltage electrical equipment. The test is often decisive for acceptance of the equipment under test, and consequently proper and precise calibration of the measuring system is needed. The present work centres on the need to quantify the errors of reference measuring systems for lightning impulse. Scale factor determination at low frequency (or DC) is the starting point for this determination. The extrapolation from this frequency domain to the domain where microsecond pulses must be faithfully captured requires application either of methods in the frequency domain or in the time domain. Radio frequency measurements are only well defined for coaxial structures and at impedances in the range of 50 O or thereabouts, making them difficult to apply to the large structures of high-voltage measuring systems. The converse method in the time domain is to apply a Dirac impulse to the system and calculate the response to an assumed input signal by convolution. A true Dirac pulse is not readily available and in practice the applied pulse is a step voltage, which is then derived with respect to time and convolved with the applied signal to obtain the response of the measuring system. The step generator used for this purpose should have very fast front without oscillations. The intent is to achieve a close approximation of an ideal step function, which when derived with respect to time, yields the impulse response of a tested system. A necessary prerequisite is that the step is much steeper than the lightning impulse, and is flat after the step on times much longer than the impulse. The ideal switch element in such a step generator should have infinite resistance and zero capacitance in the off-state, very fast switching to on-state and very low resistance in on-state. The mercury wetted reed switch has often been used for this purpose since it has good characteristics in all these respects. Few, if any, electronic components exhibit competitive advantages compared to the reed switch. The relative lack of parasitic effects means that it is close to being an ideal device. Based on earlier experiences by the authors, a new design has been developed with focus on electrical screening and coaxial design in order to realise a step generator that works into a high impedance instrument. Considerable work has been performed to characterise the new device with regard to steepness of step and most importantly, to voltage stability after the step. The most demanding part of this work has been to separate the performance of the switch from that of the oscilloscope. Findings indicate that the step rise-time is less than 0.5 ns, and settling to within 0.5 % within 10 ns.

  • 37.
    Bergsten, Tobias
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Eklund, Gunnar
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Comparison between GaAs and graphene QHR standards for resistance realisation at SP2016Conference paper (Refereed)
    Abstract [en]

    We report the first precision QHR measurements at SP using a graphene chip. We compare the results of a resistance calibration using GaAs based chips with the results using a graphene chip. The results agree within a few parts in 109 for calibrations of 100 Ω and 10 kΩ resistors. Consistency checks indicate that the uncertainty is lower with the graphene chip, and the noise level is slightly lower. The measurements with the graphene chip were performed exclusively at 4.2 K, which simplifies the calibration procedure considerably compared with GaAs chips.

  • 38.
    Bergsten, Tobias
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Eklund, Gunnar
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    He, Hans
    Chalmers University of Techology, Sweden.
    Comparing GaAs and graphene QHR standards for resistance realisation at SP2016Conference paper (Other academic)
  • 39.
    Bergsten, Tobias
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Rydler, Karl-Erik
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Realisation of Absolute Phase and Ac Resistance of Current Shunts by Ratio Measurements2018In: CPEM 2018 - Conference on Precision Electromagnetic Measurements, 2018Conference paper (Refereed)
    Abstract [en]

    This article presents a method for realising absolute phase and ac resistance for current shunts using only impedance ratio measurements. The method is based on three geometrically identical current shunts with different resistances, but with the same inductance, capacitance and ac resistance (change of resistance at ac compared to dc), We demonstrate how the inductance, capacitance and ac resistance can be calculated from the complex impedance ratio measurements, thereby realising absolute current shunt impedance. This method simplifies the procedure of current shunt calibration, since the same impedance ratio setup which is used to compare a shunt to a reference shunt, is used to realise the impedance of the starting reference shunt.

  • 40.
    Bergstrand, Sten
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Activities of the IERS Working Group on Site Survey and Co-location2016In: IVS 2016 General Meeting Proceedings: "New Horizons with VGOS" / [ed] Dirk Behrend, Karen D. Baver, and Kyla L. Armstrong, Greenbelt, MD: National Aeronautics and Space Administration , 2016, p. 113-117Conference paper (Other academic)
    Abstract [en]

    t The objective of the International Earth Rotation and Reference Systems Service (IERS) Working Group on Site Survey and Co-location is to improve local measurements at space geodesy sites. We appointed dedicated Points of Contact (POC) with the four different services of IERS as well as the NASA Space Geodesy Project in order to improve the efficiency of internal communication within the working group. Following the REFAG2014 conference, the POCs agreed on a common and general terminology on local ties that clarifies the communication regarding site surveying and co-location issues between and within the IERS services. We give brief introductions to the different observation techniques and mention some contemporary issues related to site surveying and co-location.

  • 41.
    Bergstrand, Sten
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Herbertsson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Rieck, Carsten
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Spetz, Jörgen
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Svantesson, Claes-Göran
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Haas, Rüdiger
    Chalmers University of Technology, Sweden.
    A gravitational telescope deformation model for geodetic VLBI2018In: Journal of Geodesy, ISSN 0949-7714, E-ISSN 1432-1394Article in journal (Refereed)
    Abstract [en]

    We have measured the geometric deformations of the Onsala 20 m VLBI telescope utilizing a combination of laser scanner, laser tracker, and electronic distance meters. The data put geometric constraints on the electromagnetic raypath variations inside the telescope. The results show that the propagated distance of the electromagnetic signal inside the telescope differs from the telescope’s focal length variation, and that the deformations alias as a vertical or tropospheric component. We find that for geodetic purposes, structural deformations of the telescope are more important than optic properties, and that for geodetic modelling the variations in raypath centroid rather than focal length should be used. All variations that have been identified as significant in previous studies can be quantified. We derived coefficients to model the gravitational deformation effect on the path length and provide uncertainty intervals for this model. The path length variation due to gravitational deformation of the Onsala 20 m telescope is in the range of 7–11 mm, comparing elevation 0$$^{\circ }$$∘and 90$$^{\circ }$$∘, and can be modelled with an uncertainty of 0.3 mm.

  • 42.
    Bertilsson, Simon
    et al.
    Chalmers University of Technology, Sweden.
    Larsson, Fredrik
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics. Chalmers University of Technology, Sweden.
    Furlani, Maurizio
    University of Gothenburg, Sweden.
    Albinsson, Ingvar
    University of Gothenburg, Sweden.
    Mellander, Bengt Erik
    Chalmers University of Technology, Sweden.
    Lithium-ion battery electrolyte emissions analyzed by coupled thermogravimetric/Fourier-transform infrared spectroscopy2017In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 365, p. 446-455Article in journal (Refereed)
    Abstract [en]

    In the last few years the use of Li-ion batteries has increased rapidly, powering small as well as large applications, from electronic devices to power storage facilities. The Li-ion battery has, however, several safety issues regarding occasional overheating and subsequent thermal runaway. During such episodes, gas emissions from the electrolyte are of special concern because of their toxicity, flammability and the risk for gas explosion. In this work, the emissions from heated typical electrolyte components as well as from commonly used electrolytes are characterized using FT-IR spectroscopy and FT-IR coupled with thermogravimetric (TG) analysis, when heating up to 650 °C. The study includes the solvents EC, PC, DEC, DMC and EA in various single, binary and ternary mixtures with and without the LiPF6 salt, a commercially available electrolyte, (LP71), containing EC, DEC, DMC and LiPF6 as well as extracted electrolyte from a commercial 6.8 Ah Li-ion cell. Upon thermal heating, emissions of organic compounds and of the toxic decomposition products hydrogen fluoride (HF) and phosphoryl fluoride (POF3) were detected. The electrolyte and its components have also been extensively analyzed by means of infrared spectroscopy for identification purposes.

  • 43.
    Beyler, C
    et al.
    Jensen Hughes, USA.
    Croce, P
    Factory Mutual Emeritus, USA..
    Dubay, C
    National Fire Protection Association, USA.
    Johnson, P
    Arup, Australia.
    McNamee, Margaret
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Oxygen consumption calorimetry, William Parker: 2016 DiNenno Prize2017In: Fire Science Reviews, Vol. 6, no 1Article in journal (Refereed)
    Abstract [en]

    The 2016 DiNenno Prize recognizes oxygen consumption calorimetry as a significant technical achievement that has had a major impact on public safety. Oxygen consumption calorimetry has made the measurement of heat release rate of a fire a routine part of fire testing for both research and for regulatory compliance. Heat release rate is a primary metric of fire size which is foundational in modern fire protection engineering. The 2016 Philip J. DiNenno Prize is awarded to Dr. William Parker, with ample commendation to his deceased collaborator, Dr. Clayton Huggett. Others who made contributions to the early development and application of oxygen consumption calorimetry include Peter Hinkley, William Christian, Thomas Waterman, Darryl Sensenig, Ralph Krause, Richard Gann, Vyto Babrauskas, Gunnar Heskestad, Norm Alvares, Donald Beason, and Brady Williamson. This review presents an overview of the background to the technological development and its impact on public safety

  • 44.
    Beyler, Craig
    et al.
    Jensen Hughes, USA.
    Lucht, David
    Worcester Polytechnic Institute, USA.
    McNamee, Margaret
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Johnson, Peter
    Arup, Denmark.
    Dubay, Chris
    National Fire Protection Association, USA.
    The affordable home smoke alarm, Lyman Blackwell- 2015 DiNenno Prize winner2017In: Fire Science Reviews, Vol. 6, no 2Article in journal (Refereed)
    Abstract [en]

    The 2015 Philip J. DiNenno Prize was awarded for the affordable home smoke alarm. This technology developed and implemented by Lyman L. Blackwell and Duane D. Pearsall paved the way for installation of smoke alarms in all residences. This has had a major impact on the reduction of deaths due to fire. The 2015 Philip J. DiNenno Prize was awarded to Lyman L. Blackwell, with ample commendation to his deceased compatriot, Duane D. Pearsall. Contributions were made by Paul Staby, B. K. Sweeney, Rexford Wilson, Myrle Wise, Gus Degenkolb, Eugene Cray, Jack Rhodes, Dick Bright, and Dick Bukowski. This review presents an overview of the background to the technological development and its impact on public safety.

  • 45.
    Blomfors, Mattias
    et al.
    Chalmers University of Techology, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Larsson Ivanov, Oskar
    Lund University, Sweden.
    Zandi, Kamyab
    Chalmers University of Technology, Sweden.
    Lundgren, Karin
    Chalmers University of Technology, Sweden.
    Reliability analysis of corroded reinforced concrete beam with regards to anchorage failure2018In: Life Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision, 2018Conference paper (Refereed)
  • 46.
    Blomfors, Mattias
    et al.
    Chalmers University of Gothenburg, Sweden.
    Larsson Ivanov, Oskar
    Lund University, Sweden.
    Honfí, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Engen, Morten
    Multiconsult ASA/NTNU, Norway.
    Partial safety factors for the anchorage capacity of corroded reinforcement bars in concrete2019In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 181, p. 579-588Article in journal (Refereed)
    Abstract [en]

    Many reinforced concrete bridges in Europe and around the world are damaged by reinforcement corrosion and the annual maintenance costs are enormous. It is therefore important to develop reliable methods to assess the structural capacity of corroded reinforced concrete structures and avoid unnecessary maintenance costs. Although there are advanced models for determining the load carrying capacity of structures, it is not obvious how they should be used to verify the performance of existing structures. To confidently assess the bond of corroded reinforcement in concrete, for example, the calculation model must give a sufficient safety margin. When designing new structures, semi-probabilistic approaches (such as the partial safety factor method) are adopted to achieve the target reliabilities specified in structural design codes. This paper uses probabilistic methods to develop partial factors for application in an existing bond model, to assess the safety of corroded reinforced concrete structures. The response of the bond model was studied using Monte Carlo (MC) simulations for several design cases, with probability distributions fitted to the results. Partial factors were then derived, based on these distributions. Furthermore, an MC-based simulation technique called “importance sampling” was used to study the reliability of several deterministic bond assessments conducted using these partial factors. The results show that deterministic assessments which use the proposed partial factors lead to a safety level at least equal to the target value. The results presented in this paper will support the assessment of reinforced concrete structures with anchorage problems and give a reasonable approximation of the anchorage capacity with sufficient safety margin. When generalised to cover other failure modes and structural configurations, this will enable better utilisation of damaged structures and lead to major environmental and economical savings for society.

  • 47.
    Blomfors, Mattias
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute. Chalmers University of Technology, Sweden.
    Lundgren, Karin
    Chalmers University of Technology, Sweden.
    Ivanov, Oskar L.
    Lund University, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Zandi, Kamyab
    Chalmers University of Technology, Sweden.
    Practical bond model for corroded RC bridges2017In: High Tech Concrete: Where Technology and Engineering Meet - Proceedings of the 2017 fib Symposium, 2017, p. 1793-1803Conference paper (Refereed)
    Abstract [en]

    Corrosion of steel reinforcement is a common cause of deterioration in reinforced concrete bridges and many existing bridges are damaged to varying degrees. The rate of deterioration of the bridge stock has been shown to increase due to climate change. Unsympathetically, the demand for load-carrying capacity is however often increased with time. Therefore there is an increasing need for reliable methods to assess the load-carrying capacity and remaining service-life of existing infrastructure. A simple model for the assessment of Anchorage in corroded Reinforced Concrete structures (ARC) has previously been developed. It was originally based on fib Model Code 1990 and has been verified with experiments and three-dimensional nonlinear finite element (3D NLFE) analyses for both accelerated and natural corrosion as well as for different degrees of corrosion. The model was applied when assessing two road bridges in Sweden. The investigation demonstrated great cost savings but also areas for improvement, in particular regarding (a) applicability to practical cases and (b) incorporation of uncertainties in the assessment. The primary focal point of this paper is to present an overview of the development of the ARC model together with recent verifications against a large bond test database as well as foreseen future developments. It was found that the ARC model represents the physical behaviour reasonably well, and gives conservative values of bond strength compared to the bond tests database. In future works, among others, uncertainties of the input variables will be incorporated by means of probabilistic modelling, making way for implementation of the ARC model into semi-probabilistic safety concepts by extraction of modification factors. Overall, with more accurate and reliable assessment methods for corroded RC structures, environmental and economic savings are imminent as more of the potential of existing structures can be realized.

  • 48.
    Blomqvist, Per
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport.
    Sandinge, Anna
    RISE - Research Institutes of Sweden, Safety and Transport.
    Experimental evaluation of fire toxicity test methods2018Report (Other academic)
    Abstract [en]

    An experimental evaluation of the most common bench-scale tests methods for fire toxicity was conducted by RISE Fire Research. The background of the work was the on-going discussion in the fire community on the applicability and relevance of these test methods.

    The test methods included in the programme were the ISO/TS 19700 steady-state tube furnace (SSTF), the controlled atmosphere cone calorimeter (CACC), and the EN 45545-2 smoke chamber test (SC). In these tests the production of selected toxic gases was quantitatively analysed using FTIR. Tests for the measurement of toxic gas production were made with eleven different materials used as test specimens, both combustible and non-combustible materials. The materials were commercially available insulation products provided by EURIMA, the sponsor of the project. These materials should not be regarded as typical or fully representative of a product category.

    The evaluation of the results from the different test methods was divided into combustible test specimens and non-combustible test specimens. That was because the test conditions in the first case are greatly influenced by the combustion behaviour of the test specimen, while in the second case the test conditions are more constant.

    A general observation was that there in many cases was correlation between both species composition and level of toxic gas species yields between test methods when the combustion conditions were similar. In cases where yields differed significantly it could in most cases be explained by clear differences in test conditions.

    For combustible materials it was concluded that the SSTF offers the best means for conducting tests at pre-decided and controlled flaming combustion conditions. The CACC does not give steady-state flaming combustion and the influence of vitiation was limited in the tests made. The SC generally accumulates a mixture of gases from both flaming and non-flaming combustion periods in a test, and the yields measured do not in those cases represent any specific combustion stage.

    For non-combustible materials a general observation was that any of the test methods investigated in principle could be used since the influence on the test conditions from the material itself is limited compared to combustible materials. However, there were specific properties and limitations of the different test methods observed that are important to consider.

  • 49.
    Blomqvist, Urban
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Flink, Kristian
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Maskinstyrningar i praktiken2018Report (Other academic)
    Abstract [en]

    The European Machinery directive gives the requirements for safe machinery, and safe machine control, within the European Union. This report explains some of the requirements, especially for safety-related machine control systems. Practical examples with aspects on machine control are given in annexes to the report.

  • 50.
    Boork, Magdalena
    et al.
    RISE - Research Institutes of Sweden, Built Environment.
    Wendin, Karin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Agrifood and Bioscience.
    Nordén, Johan
    RISE - Research Institutes of Sweden.
    Nilsson Tengelin, Maria
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Innemiljö i nytt ljus: Metoder för objektiv bedömning av belysning2017Report (Other academic)
    Abstract [sv]

    Nuvarande belysningsstandarder baseras enbart på tekniska krav, såsom ljusstyrka, jämnhet och luminans. Att även inkludera upplevelsebaserade krav skulle troligen främja bättre ljuskomfort, men även mer energieffektiva ljusmiljöer och produkter. Kunskapen om hur upplevda belysningsparametrar kan beskrivas är dock begränsad. Detta hämmar fastighetsägare och brukare att precisera önskvärda ljusmiljöer, liksom belysningstillverkare att utveckla produkter för nya marknader och tillämpningar. Syftet med detta forskningsprojekt var att utveckla och tillämpa sensoriska metoder på belysning. Till skillnad från tidigare metoder möjliggör sensoriska metoder objektiva bedömningar av upplevda belysningsparametrar.

    En analytisk panel bestående av åtta personer som uppfyller särskilda urvalskriterier rekryterades och tränades att bedöma belysningsprodukter i ett multisensoriskt laboratorium på SP Sveriges Tekniska Forskningsinstitut i Borås. Metodutvecklingen fokuserade särskilt på en effektiv träningsprocedur, hantering av ögats adaption, samt bedömning av färg och skuggningar. Förutom laboratorie-försök undersöktes möjligheten att genomföra analytiska bedömningar i en verklig kontext med samma försöksuppställning och panel.

    Resultaten visar att det är möjligt att använda sensorisk metodik för att genomföra objektiva belysningsbedömningar av armaturer; paneldeltagarna kunde skilja mellan attribut och prover. Signifikanta skillnader identifierades mellan de olika armaturerna, både i form av sensoriska och fysikaliska egenskaper såsom läsbarhet och bländning. Fysikaliska och sensoriska parametrar samvarierar dock inte alltid, vilket visar att fysikaliska och sensoriska mätningar ger kompletterande information om belysningskvalitet. Vidare visade bedömningsförsök i en verklig kontext att samma resultat uppnåddes som i laboratoriet, men med lägre signifikans, vilket verifierar metodens tillämpbarhet på belysning.

    Den genererade kunskapen väntas på sikt bidra till utveckling av verktyg som stödjer kommunikationen mellan olika professioner inom ljusdesign och planering och på så vis främja mer önskvärda och energieffektiva ljusmiljöer.

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