148 research outputs found
Fire hazard analysis of hetero-organic fuels - Source characteristics from experiments
Source characteristics from experiments with hetero-organic fuels are presented. The results are intended as input to fire hazard analysis. The results imply that it is possible to use experiments in reduced scale to get an indication of the combustion products that can be produced in a fire with hetero-organic fuels as well as the levels of yields that can expected in a fire involving chemicals
Model scale compartment fire tests with wall lining materials
Two series of tests with wall lining materials in an extensively equipped model scale room have been carried out. The dimensions of the room were 1.2 X 0.8 X 0.8 m³. In test series I the wall lining materials were mounted on three walls and in the ceiling. This test series comprised thirteen different materials. In test series I1 ten different materials were tested. They were mounted on the walls only. The test compartment was instrumented for measurement of gas temperatures. surface temperatures, heat flux. rate of heat release and for analysis of oxygen. Carbonmonoxide, carbondioxide and smoke.The ignition source was a propane gas diffusion burner. During the first 10 minutes the burner output was 11 kW. If no sustained burning in the material was achieved during this period the energy output was raised tv 33 kW. In the report all the collected data are summarized in tables, giving values at flashover and for combustion products production rates and total production. In appendices the time curves for the measured variables are given together with visual observations made during the tests
Fire Behaviour of Upholstered Furniture - An Experimental Study
The first and largely experimental part of a research program on flammability characteristics of upholstered furniture has been completed with full-scale tests in an extensively instrumented burn-out room as main element. The results indicate that fire response parameters vary within a large range with choice of filling, interlining and fabric material. Selection of performance criteria may cause difficulties, as parameters like heat release and smoke potential fluctuate strongly during the fire process. A second part of the program will be directed towards measurement of heat release by oxygen consumption methods, more detailed smoke and gas analysis measurements and use of mathematical simulation procedures
Introduktion till konsekvensberäkningar. Några förenklade typfall
I dagens samhälle krävs i många fall genomförande av risk- och/eller konsekvensanalyser. Krav ställs dels från myndigheter och dels inom enskilda företag och organisationer. Här kommer endast konsekvensanalyser att behandlas. Anledningen till att genomföra en konsekvensanalys kan skifta. Som nämnts kan krav på en konsekvensalanys komma utifrån från myndigheter och dels kan en analys utföras för att ge ett företag underlag för åtgärdsplanering. Att göra en inventering av vilka risker som finns inom företaget och vilka konsekvenser dessa kan ge upphov till är ofta mycket lärorikt. Syftet med här nedan redovisat arbete är att på svenska ge en sammanställning över beräkningsmetoder som kan användas vid en konsekvensanalys för att göra uppskattningar med hjälp av handräkningsmetoder. I många fall är det tillräckligt att göra denna typ av beräkningar för att gå en uppfattning om storleken på konsekvenserna av ett oplanerat utsläpp. Vid omfattande analyser är det till stor hjälp att ha tillgång till något av de datorprogram för konsekvensberäkningar som finns på marknaden. Handräkningsmetoderna kan då utnyttjas som enkla kontrollinstrument av att man gett rätt indata till de beräkningsmodeller som finns i datorprogrammet. Exakt överensstämmelse får man naturligtvis inte mellan resultaten men en storleksjämförelse är ändå viktig. Sammanställningen innehåller material från ett antal, inom området, välkända referenser. Uppläggningen har gjorts så att i de fall materialet hämtats från orginalreferensen så anges denna i annat fall hänvisas till de generella referenser som finns angivna i referenslistan. Härledningar har genomgående utelämnats och för studier av dessa hänvisas till de generella referenserna. Det redovisade arbetet initierades av Länsstyrelsen i Malmöhus län av det under 1989 pågående RAM-projektet (Risk-Analys-Malmöhus-län). Delvis har arbetet utförst inom detta projekt och även till en del finansierats av RAM-projektet
Use of participatory scenario modelling as platforms in stakeholder dialogues
A participatory methodology, based on dialogues between stakeholders and experts has been developed and tested in the drainage area to Kaggebo Bay in the Baltic Sea. This study is focused on the EU Water Framework Directive, with emphasis on reduction of eutrophication. The drainage area is included in the WFD administrative area of the Motala Ström River basin. A similar approach is now applied in a recently initiated project in the Thukela River basin, with focus on impacts of climate change on water resources. The methodology is based on the idea that a catchment model serves as a platform for the establishment of a common view of present conditions and the causes behind these conditions. In the following steps, this is followed by model-assisted agreement on environmental goals (i.e. what do we want the future to look like?) and local agreement on a remedy or mitigation plans in order to reduce environmental impact (e.g. eutrophication); alternatively to adapt to conditions that cannot be determined by local actions (e.g. climate change). By involving stakeholder groups in this model-supported stepwise process, it is ensured that all stakeholder groups involved have a high degree of confidence in the presented model results, and thereby enable various actors involved to share a common view, regarding both present conditions, goals and the way to reach these goals. Although this is a process that is time- (and cost-) consuming, it is hypothesised that the use of this methodology is two-pronged: it increases the willingness to carry out remedies or necessary adaptations to a changing environment, and it increases the level of understanding between the various groups and therefore ameliorates the potential for future conflicts. Compared to traditional use of model results in environmental decision-making, the experts’ role is transformed from a one-way communication of final results to assistance in the various steps of the participatory process.Keywords: participatory, catchment, coastal zone, modelling, nutrient
Analysis of Fire Scenarios in Order to Ascertain an Acceptable Safety Level in Multi-Functional Buildings
The construction of multifunctional buildings has increased over the last years as well as the threat level considering antagonistic events. This presents challenges for the fire safety in these types of buildings since the protection objectives needs to be more focused on the functions the buildings are providing. Further the antagonistic exposures might present more challenging fire scenarios. A structured method how to determine fire scenarios in order to ascertain an acceptable safety level in multifunctional buildings has been developed and is based on the SFPE Engineering guides Fire Risk Assessment and Performance-Based Fire Protection. The method provides guidance on how to determine assets worth to preserve, protection objectives, exposures and finally the fire scenarios for multifunctional buildings. Previous accidents and events are discussed and serve as a background to the additional considerations needed for multifunctional buildings (compared to general buildings) and related to antagonistic exposures when determining fire scenarios. This article is a part of the project SAFE Multibygg that focuses on a methodology to identify fire risks with respect to antagonistic attacks in multifunctional buildings and to define fire safety solutions
Combustion of Chemical Substances and the Impact on the Environment of the Fire Products: 1/3 Scale Room Furnace Experiments
This report describes the results obtained from fire tests in a 1/3-scale room. The aim of the study was to investigate how changes in external radiation and oxygen supply affect the production of smoke and toxic gases. The ventilation was varied to simulate under- and well-ventilated fires. The thermal exposure to the materials was varied to simulate fires of different sizes. Fifty-nine tests were performed, with polystyrene, FR polystyrene, polypropylene, nylon and PVC. Measurements were made of the contents of O2, CO2, CO, NOx, and HC in the exhaust gases. The impact of external radiation was mainly to increase the pyrolysis rate, and thus the rate of heat release, and to drive the fire into under-ventilation. The degree of ventilation proved to have the greatest impact on the combustion efficiency. The smoke production was almost constant for polypropylene and nylon. The CO production appeared to be the most complex of the parameters to describe, and the expected increase in CO yield at low yields of CO2 could not be seen. The generation of NOx was low for the two substances without chemically bound nitrogen, but for nylon, the generation was significant. The production of low molecular weight HC was essentially constant for all three materials. Almost all the carbon was recovered in wellventilated fires, but at under-ventilated conditions, only 30% of the carbon from the he1 was detected. The toxic potency of the exhaust gases was estimated using the N-gas model, and proved to be relatively low. Lack of oxygen and the production of carbon oxide had the greatest impact on the toxicity for polystyrene and polypropylene, while NO, represented the main part for nylon. The survival fraction and the decomposition products from the original materials are not considered in the model. It can therefore not be assumed that the model reflects all aspects of the toxicity problem
Naturgas Säkerhetsnivå Riskanalys
Denna rapport har tillkommit på uppdrag av NUTEK och avser att belysa riskerna med distribution och industriell användning av naturgas. Tidigare har en rapport avseende naturgasinstallationer i hemmen utgetts [1,2]. Rapporten inleds med en allmän diskussion om risker. Vidare tas frågan om lagstiftning, tillsyn, kontroll och utbildning för naturgasanvändning i olika lander upp. Dessutom har en retrospektiv sökning efter statistik om naturgasolyckor samt incidenter gjorts. En kort genomgång av hur man beräknar konsekvenser av naturgasutsläpp görs också
Considerations needed for analysing data from the Swedish Electrofishing RegiSter (SERS), with special reference to the RivFishTIME database of long-term riverine surveys
The published database RivFishTIME (Comte et al. 2021, Global Ecology and Biogeography, doi: 10.1111/geb.13210) includes a large section of time-series data on fish abundance in Swedish rivers from the Swedish Electrofishing RegiSter, SERS. Knowledge about the limitations of the source data are important when extracting and analyzing data and with this brief note we provide some details that may be helpful for interpreting the Swedish time-series. The note highlights the importance of linking vital metadata to extracted focal data when constructing new databases, especially concerning time series data from monitoring programs conducted in non-randomly selected sites with human environmental impacts. Many of the SERS data come from rivers that have been affected by human impact, e.g. liming to mitigate environmental acidification and hydropower dams, since before monitoring was initiated. Data in SERS are also biased towards shallow salmonid habitats, due to the configuration of Swedish monitoring programs. Hence, data from many rivers are not representative of their fish biodiversity in general. This information is vital for appropriate interpretation of fish biodiversity trends. For RivFishTIME analyses considerations are important since Swedish data constitutes a large proportion of the database. We also provide background information about SERS and references to other Swedish databases containing complementary information. Finally, we provide contact information of the SERS database curators, who can assist prospective analysts with data extraction from SERS
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