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In recent decades, the intensity of wildfires worldwide has escalated, leading to a rise in the destruction of structures and loss of lives within the Wildland-Urban Interface (WUI). Firebrands are small fragments of ignited vegetation or structural material that are carried by the plume of a wildfire, traveling in advance of the main fire front. Firebrand exposure has been recognized as the primary mechanism for the propagation of wildfires as well as a source of ignition of structural elements. However, this complex ignition process of structural elements in the WUI has yet to be fully understood. The ignition and combustion characteristics of a thermoplastic-wood composite (Trex) and Pressure Treated Wood (PTW), two frequently used WUI decking materials, when exposed to glowing firebrand piles were studied using a bench scale wind tunnel. An inert insulation material, ii Kaowool PM, was also used as a deposition substrate to quantify the heat feedback and combustion characteristics of solely the firebrand pile. Firebrand pile densities of 0.16 g cm-2 and 0.06 g cm-2 were deposited on each substrate in rectangular 10 cm x 5 cm orientations and exposed to air flow velocities of 0.9 m s-1, 1.4 m s-1, 2.4 m s-1, and 2.7 m s-1. Infrared camera measurements were used to determine the back surface temperatures of Kaowool PM tests. Using DSLR cameras, surface ignitions of the decking material in front of the firebrand pile (preleading zone ignition events), ignitions on top of the firebrand pile (pile ignition events), and surface ignitions of the decking material behind the firebrand pile (downstream ignition events) were visually quantified via their probability of ignition, time to ignition, and burn duration at each testing condition. A gas analyzer was used to compare combustion characteristics of Trex, PTW, and Kaowool PM tests through heat release rate (HRR) and modified combustion efficiency (MCE). Peak back surface temperatures of the firebrand pile were found t

CERN is the world's largest particle physics laboratory, housing multiple accelerators that rely heavily on magnetic coils. These coils are integral to the generation of powerful magnetic fields essential for particle accelerator experiments, detectors, and other equipment. At CERN, a range of magnetic coils are utilized, many of which are custom-made and located in various research facilities both above and below ground. However, these magnetic coils include epoxy resins, making them susceptible to fire hazards. Given the unique nature of CERN, a thorough engineering approach is required for fire safety design. Therefore, understanding the flammability characteristics of the epoxy resin used in magnetic coils is therefore crucial for ensuring proper fire safety measures at CERN. The focus of this thesis is to investigate and gain a deeper understanding of the fire risk and fire behaviour associated with the epoxy resins used in magnetic coils at CERN that operate at ambient temperatures. In the first part of the thesis, the key factors that impact the flammability of epoxy resins and composites have been identified and their effects are well understood. Literature shows that the mechanical properties of epoxy resins can degrade due to radiation and aging, which represents a potential ignition source. The second section of the thesis involves conducting four standardized tests on three representative epoxy resins used at CERN. Two of the epoxy resins are from magnetic coils that have been exposed to radiation environments for a considerable amount of time. These tests include micro-combustion calorimetry, cone calorimetry, lateral ignition and flame spread testing, and thermogravimetric analysis combined with Fourier transform infrared spectroscopy. The tests evaluate the ignition behavior, fire spread behavior, and flammability properties of the epoxy resins., The European Council for Nuclear Research (CERN), located in Switzerland, is the largest particle physics laboratory in the world. Their main aim is to explore the fundamental composition of the particles that constitute our universe. To achieve this, they make subatomic particles collide at incredibly high speeds, almost at the speed of light. This collision process provides valuable clues about how these particles interact with each other, giving us insights into their inner workings and the structure of the universe. Given the uniqueness of CERN, their fire safety requirements are much higher than for any typical residential or factory building. It is required a comprehensive understanding of fire science and the flammability characteristics of all equipment to assess and mitigate the potential risks associated with fire incidents. CERN utilizes specially designed particle accelerators as the primary instrument for their scientific research. These accelerators heavily rely on the use of magnetic coils, which play a crucial role in generating powerful magnetic fields to control and direct particle beams. Due to the complex nature and high electrical currents involved, the magnet coils necessitate reliable electrical insulation. Epoxy resins, a type of polymer, are commonly used for this purpose. However, it is important to note that epoxy resins pose a fire hazard, highlighting the need to understand their flammability characteristics. To achieve the mentioned goal, samples extracted from two distinct magnet coils, which were dismantled from an accelerator, underwent testing four standardized test methods. Additionally, a sample that was recently manufactured and had not been exposed to the operational conditions of the magnet coils was also included in the testing process. Due to the high cost and rarity of these magnet coils, the availability of samples was limited, necessitating careful planning of the experimental processes. The testing procedure comprised two

In this study, an analysis of the influence of extractives, suberin and lignocellulosic components on the pyrolysis decomposition and fire reaction mechanisms of a cork oak powder from Quercus suber L. is presented. The summative chemical composition of cork powder was determined. Suberin was the main component at 40% of the total weight, followed by 24% of lignin, 19% of polysaccharides and 14% of extractives. The absorbance peaks of cork and its individual components were further analyzed by means of ATR-FTIR spectrometry. Thermogravimetric analysis (TGA) showed that the removal of extractives from cork slightly increased the thermal stability between 200 °C and 300 °C and led to the formation of a more thermally stable residue at the end of the cork decomposition. Moreover, by removing suberin, a shift of the onset decomposition temperature to a lower temperature was noticed, indicating that suberin plays a major role in enhancing the thermal stability of cork. Furthermore, non-polar extractives showed the highest flammability with a peak of heat release rate (pHRR) of 365 W/g analyzed by means of micro-scale combustion calorimetry (MCC). Above 300 °C, the heat release rate (HRR) of suberin was lower than that of polysaccharides or lignin. However, below that temperature it released more flammable gases with a pHRR of 180 W/g, without significant charring ability, contrary to the mentioned components that showed lower HRR due to their prominent condensed mode of action that slowed down the mass and heat transfer processes during the combustion process., Peer Reviewed, Postprint (published version)

Fire is an important disturbance globally, shaping the structure and composition of many forested ecosystems. While fire is a natural process, large, extreme fire events can have devastating consequences on people and the environment. Predicting when and where fires occur is key to being able to manage these impacts. Most forest fires start as small fires, igniting and initially spreading in the litter bed – the layer of dead leaves, twigs and bark on the forest floor. Despite the importance of litter beds to wildfire occurrence and intensity, our understanding of the drivers of litter bed flammability remains incomplete. Thus, the over-arching aim of this thesis was to examine the drivers of litter bed properties and flammability, in order to better understand the mechanisms underpinning litter bed flammability. Starting at the leaf-scale, I reviewed the literature on leaf traits, litter structure and flammability to summarise current knowledge and identify knowledge gaps (Chapter 2). I performed a meta-analysis using existing data collated from key laboratory flammability studies in different fire-prone biomes. Leaf traits predominately influenced flammability indirectly, via litter structure. The packing ratio and bulk density of the litter bed were influenced by different combinations of leaf traits and, in turn, they aligned with different flammability metrics. Importantly, the effects of the leaf and litter traits were consistent across a wide range of taxa and biomes. However, uncertainty remained regarding whether the relationships identified in simple litter beds continue to be important at field-scales in litter beds which are more complex in relation to their structure, composition, and moisture content. Hence, I developed and tested the effectiveness of a laboratory method to measure ignitability of litter beds collected from the field (Chapter 3). I examined how the results of this laboratory method matched a similar but more logistically complex field

Fire has been an ecosystem process since plants colonized land over 400 million years ago. Many diverse traits provide a fitness benefit following fires, and these adaptive traits vary with the fire regime. Some of these traits enhance fire survival, while others promote recruitment in the postfire environment. Demonstrating that these traits are fire adaptations is challenging, since many arose early in the paleontological record, although increasingly better fossil records and phylogenetic analysis make timing of these trait origins to fire more certain. Resprouting from the base of stems is the most widely distributed fire-adaptive trait, and it is likely to have evolved under a diversity of disturbance types. The origins of other traits like serotiny, thick bark, fire-stimulated germination, and postfire flowering are more tightly linked to fire. Fire-adaptive traits occur in many environments: boreal and temperate forests, Mediterranean-type climate (MTC) shrublands, savannas, and other grasslands. MTC ecosystems are distinct in that many taxa in different regions have lost the resprouting ability and depend solely on postfire recruitment for postfire recovery. This obligate seeding mode is perhaps the most vulnerable fire-adaptive syndrome in the face of current global change, particularly in light of increasing anthropogenic fire frequency.

Understanding the impacts of climate change on future fire activity is critical for assessing the risks posed to biodiversity and communities. However, the mechanisms through which climate change may influence fire activity are varied. In temperate forests, climate change is expected to directly increase fire activity through elevated temperatures and more variable rainfall, resulting in weather conditions conducive to large fire events. However, climate change may indirectly influence fire activity through effects on forest structure and composition. While the direct effects of climate change are well studied, indirect mechanisms are poorly understood. These mechanisms are important because changes to vegetation structure and composition have the potential to amplify or dampen the direct effects of climate change on fire activity through their effects on fuels, particularly dead fuel moisture content (FMC). Forest structure and composition moderate microclimate conditions compared to the open, which is an important factor affecting the moisture content of understorey fuels. FMC is a key determinant of fire activity, particularly in wet Eucalypt forests with high biomass loads. However, our understanding of the magnitude of forest structure and composition effects on microclimate and subsequently FMC dynamics, is a critical knowledge gap in our understanding of climate change effects on future fire activity more broadly. In this thesis, I aimed to quantify the potential for indirect effects of climate change to influence fire activity, through their influence on dead FMC in the wet Eucalypt forests of south-eastern (SE) Australia. In these forests, recurrent high-intensity fire has altered vegetation structure and composition, resulting in a range of alternative forest states to the dominant wet Eucalypt system. To quantify the magnitude of these on potential fire activity, seven alternative forest states and two adjacent open weather stations were instrumented with

Natural refrigerants are being increasingly adopted by heat pump manufacturers. Heat pumps using flammable refrigerants need to satisfy charge limit requirements from standard IEC/EN 60335-2-40 and EN 378. The allowed refrigerant amount for the specific application is directly related to the Low Flammability Level (LFL). A possibility to reduce refrigerant flammability and allow a higher refrigerant charge is to adopt or design mixtures in which a hydrocarbon is mixed with a less flammable refrigerant. This work investigated the differences between LFL data available in international and European standards, and those calculated using theoretical methods. In the case of natural refrigerant mixtures R-432A, R-433B, and R-433C, approved in ASHRAE 34 and ISO817, it was found that the differences were between 26 % and 52 %. Differences in LFL test results for pure refrigerants, caused by the inter-laboratory spread, may partly explain the inconsistencies in the LFL of mixtures. Moreover, if not printing errors, unit conversion errors were found in ASHRAE 34 for the mixtures R-429A, R-430A, R-431A, R-433A, R-433C, and in EN 378-1 for mixture R-433B.

Wood fiber filled high density polyethylene composites (WPCs) were prepared using twin screw extruder and maleated polyethylene as a coupling agent. Bamboo fibers were initially treated with alkali (NaOH), boric acid - borax (Ba-Bx) and borax (Bx). The treated and untreated fibers were used in combination with ammo-nium polyphosphate (APP) to investigate their synergistic effects on thermal stability, flame retardancy and mechanical properties. Alkali pretreatment (5 % NaOH) of fibers showed significant improvement in perfor-mance of APP by increasing thermal stability in WPCs. The derivative thermogravimetric (DTG) results indi-cate significance of Ba-Bx in promoting char induction at lower temperatures (340 ºC) and thereby, improved the thermal stability in WPCs. Flammability decreased with addition of flame retardant additives. As compared to pure WPCs, composites containing APP 10 % / Ba-Bx 5 % exhibited maximum reduction in average heat release rate (HRR) by 69 %, peak heat release rate (PHRR) by 59 %, total heat released rate (THR) by 48 % and also increased time to ignition (TTI) by 62 %. However, no significant difference was found among the combinations i.e., APP with or without compounds towards reducing the flammability of WPCs. The strength properties also reduced significantly when boron compounds were added along with APP. In general, APP alone (15 %) is enough for imparting thermal stability and flame retardancy in WPCs

Wood fiber filled high density polyethylene composites (WPCs) were prepared using twin screw extruder and maleated polyethylene as a coupling agent. Bamboo fibers were initially treated with alkali (NaOH), boric acid - borax (Ba-Bx) and borax (Bx). The treated and untreated fibers were used in combination with ammo-nium polyphosphate (APP) to investigate their synergistic effects on thermal stability, flame retardancy and mechanical properties. Alkali pretreatment (5 % NaOH) of fibers showed significant improvement in perfor-mance of APP by increasing thermal stability in WPCs. The derivative thermogravimetric (DTG) results indi-cate significance of Ba-Bx in promoting char induction at lower temperatures (340 ºC) and thereby, improved the thermal stability in WPCs. Flammability decreased with addition of flame retardant additives. As compared to pure WPCs, composites containing APP 10 % / Ba-Bx 5 % exhibited maximum reduction in average heat release rate (HRR) by 69 %, peak heat release rate (PHRR) by 59 %, total heat released rate (THR) by 48 % and also increased time to ignition (TTI) by 62 %. However, no significant difference was found among the combinations i.e., APP with or without compounds towards reducing the flammability of WPCs. The strength properties also reduced significantly when boron compounds were added along with APP. In general, APP alone (15 %) is enough for imparting thermal stability and flame retardancy in WPCs

[EN] There are many types of fabric materials used in military applications. From clothing to protective equipment, fabric analysis mostly focused on its physical properties. Still, its flammability has not been well studied, such as ease of ignition, heat release, and toxicity. This paper reports the flammability properties of fabric in military applications. The ignition time, heat release, and smoke production of six commercially available military fabrics are discussed in this article. The fabrics analysed are cotton, polyester-cotton, coated nylon, and kenaf fabric. The fabric grouping into the coated and printed fabric while cotton and kenaf were tested as a comparison. Results indicated that coated fabric (N420D and N1000D) showed higher TTI compared to printed fabric (P35C65, P35C65M, and P65C35). It is affected by heat flux, the areal density of the sample, sample mass, and the number of sample layers. Coated fabrics (N420D and N1000D) indicate higher EHC compared with other fabrics. For printed fabric, a relatively lower EHC was observed as it indicates incomplete combustion. Total heat release of the samples tested was presented as an integration of the HRR vs time curve. Coated samples show the highest values for PHRR and THR values compared to printed and cotton fabrics.

[EN] There are many types of fabric materials used in military applications. From clothing to protective equipment, fabric analysis mostly focused on its physical properties. Still, its flammability has not been well studied, such as ease of ignition, heat release, and toxicity. This paper reports the flammability properties of fabric in military applications. The ignition time, heat release, and smoke production of six commercially available military fabrics are discussed in this article. The fabrics analysed are cotton, polyester-cotton, coated nylon, and kenaf fabric. The fabric grouping into the coated and printed fabric while cotton and kenaf were tested as a comparison. Results indicated that coated fabric (N420D and N1000D) showed higher TTI compared to printed fabric (P35C65, P35C65M, and P65C35). It is affected by heat flux, the areal density of the sample, sample mass, and the number of sample layers. Coated fabrics (N420D and N1000D) indicate higher EHC compared with other fabrics. For printed fabric, a relatively lower EHC was observed as it indicates incomplete combustion. Total heat release of the samples tested was presented as an integration of the HRR vs time curve. Coated samples show the highest values for PHRR and THR values compared to printed and cotton fabrics.

[EN] There are many types of fabric materials used in military applications. From clothing to protective equipment, fabric analysis mostly focused on its physical properties. Still, its flammability has not been well studied, such as ease of ignition, heat release, and toxicity. This paper reports the flammability properties of fabric in military applications. The ignition time, heat release, and smoke production of six commercially available military fabrics are discussed in this article. The fabrics analysed are cotton, polyester-cotton, coated nylon, and kenaf fabric. The fabric grouping into the coated and printed fabric while cotton and kenaf were tested as a comparison. Results indicated that coated fabric (N420D and N1000D) showed higher TTI compared to printed fabric (P35C65, P35C65M, and P65C35). It is affected by heat flux, the areal density of the sample, sample mass, and the number of sample layers. Coated fabrics (N420D and N1000D) indicate higher EHC compared with other fabrics. For printed fabric, a relatively lower EHC was observed as it indicates incomplete combustion. Total heat release of the samples tested was presented as an integration of the HRR vs time curve. Coated samples show the highest values for PHRR and THR values compared to printed and cotton fabrics.

[EN] There are many types of fabric materials used in military applications. From clothing to protective equipment, fabric analysis mostly focused on its physical properties. Still, its flammability has not been well studied, such as ease of ignition, heat release, and toxicity. This paper reports the flammability properties of fabric in military applications. The ignition time, heat release, and smoke production of six commercially available military fabrics are discussed in this article. The fabrics analysed are cotton, polyester-cotton, coated nylon, and kenaf fabric. The fabric grouping into the coated and printed fabric while cotton and kenaf were tested as a comparison. Results indicated that coated fabric (N420D and N1000D) showed higher TTI compared to printed fabric (P35C65, P35C65M, and P65C35). It is affected by heat flux, the areal density of the sample, sample mass, and the number of sample layers. Coated fabrics (N420D and N1000D) indicate higher EHC compared with other fabrics. For printed fabric, a relatively lower EHC was observed as it indicates incomplete combustion. Total heat release of the samples tested was presented as an integration of the HRR vs time curve. Coated samples show the highest values for PHRR and THR values compared to printed and cotton fabrics.

[EN] There are many types of fabric materials used in military applications. From clothing to protective equipment, fabric analysis mostly focused on its physical properties. Still, its flammability has not been well studied, such as ease of ignition, heat release, and toxicity. This paper reports the flammability properties of fabric in military applications. The ignition time, heat release, and smoke production of six commercially available military fabrics are discussed in this article. The fabrics analysed are cotton, polyester-cotton, coated nylon, and kenaf fabric. The fabric grouping into the coated and printed fabric while cotton and kenaf were tested as a comparison. Results indicated that coated fabric (N420D and N1000D) showed higher TTI compared to printed fabric (P35C65, P35C65M, and P65C35). It is affected by heat flux, the areal density of the sample, sample mass, and the number of sample layers. Coated fabrics (N420D and N1000D) indicate higher EHC compared with other fabrics. For printed fabric, a relatively lower EHC was observed as it indicates incomplete combustion. Total heat release of the samples tested was presented as an integration of the HRR vs time curve. Coated samples show the highest values for PHRR and THR values compared to printed and cotton fabrics.

Serotiny is a well-known fire adaptive trait in some species, as the Mediterranean conifer Pinus halepensis. However, information about cone opening mechanisms during wildfires and consequences on post fire dispersal is scarce. In addition, standardized methods allowing a realistic simulation of heating modes at bench-scale are not available. In this study, we address for the first time the interacting effects of radiation, convection and direct flame on the opening and seed release of serotinous cones, following a novel repeatable methodology. Using a Mass Loss Calorimeter (MLC) device and a wide range of heat exposures (between 5 and 75 kW m-2) with or without ignition, we intended to simulate realistic cone heating during surface and crown fires in laboratory conditions. Additionally, we included the effect of contrasting serotinous cone ages interacting with heating mode and considering the random individual variation. The proposed methodology has shown a high potential to simulate the complex process of crown fires in relation to cone opening under controlled conditions, detecting a threshold of heat exposure (25-30 kW m-2) for cone opening. We confirmed that heating mode had a highly significant effect in cone opening, interacting with cone age, while cone age effect on its own was marginal. Particularly, ignition significantly increased the efficacy of cone opening and seed release. Moreover, young and old cones behave differently in seed release, both in surface and crown fire simulations. Implementing and adjusting this methodology in other species will allow more realistic and reliable quantitative comparisons than previously attained.

При производстве рабочей одежды используются натуральные, синтетические и смесовые ткани. Натуральные ткани хорошо пропускают воздух, гигиеничные, не вызывают раздражения, не накапливают статическое электричество, но уступают синтетике по износостойкости, прочности и устойчивости к загрязнениям. Синтетические ткани эластичны, долговечны, легко стираются, но у них есть свои недостатки - они плохо пропускают воздух, не комфортные при высокой температуре, могут вызывать раздражение кожи. Самые популярные ткани для изготовления спецодежды - смесовые. Материал нужно выбирать для определенных условий. Материал, который отвечает всем требованиям, предъявляемым к спецодежде сварщика является базальтовая ткань, которая не воспламеняется, не горит, не подвергается коррозии, виброустойчива, обладает высокой химической стойкостью к щелочным и кислотным средам, рабочий диапазон температур от -250 °С до +700 °С, а также обладает долговечностью, высокой стойкостью к разложению и механическому износу., In the production of workwear, natural, synthetic and blended fabrics are used. Natural fabrics well pass air, hygienic, do not cause irritation, do not accumulate static electricity, but are inferior to synthetics in terms of wear resistance, strength and resistance to pollution. Synthetic fabrics are elastic, durable, easy to wash, but they have their drawbacks - they are poorly breathable, not comfortable at high temperatures, and can cause skin irritation. The most popular fabrics for the manufacture of workwear are blended. The material must be selected for certain conditions. The material that meets all the requirements for the workwear of the welder is basalt fabric, which is not ignited, does not burn, does not undergo corrosion, is vibration resistant, has high chemical resistance to alkaline and acidic media, operating temperature range from -250 °C to +700 °C, and also has durability, high resistance to decomposition and mechanical wear.

The effect of pyrolysis reactors on the properties of biochars (with a focus on flammability and mechanical characteristics) were investigated by keeping factors such as feedstock, carbonisation temperature, heating rate and residence time constant. The reactors employed were hydrothermal, fixed-bed batch vertical and fixed-bed batch horizontal-tube reactors. The vertical and tube reactors, at the same temperature, produced biochars having comparable elemental carbon content, surface functionalities, thermal degradation pattern and peak heat release rates. The hydrothermal reactor, although, a low-temperature process, produced biochar with high fire resistance because the formed tarry volatiles sealed water inside the pores, which hindered combustion. However, the biochar from hydrothermal reactor had the lowest nanoindentation properties whereas the tube reactor-produced biochar at 300 degrees C had the highest nanoindentation-hardness (290 Megapascal) and modulus (ca. 4 Gigapascal) amongst the other tested samples. Based on the inherent flammability and mechanical properties of biochars, polymeric composites' properties can be predicted that can include them as constituents., QC 20210929

This work demonstrates the introduction of various α-aminophosphonate compounds to an epoxy resin system, thereby improving flame retardance properties. The α-aminophosphonate scaffold allows for covalent incorporation (via the secondary amine) of the compounds into the polymer network. This work explores the synergistic effect of phosphorus and halogens (such as fluorine) to improve flame retardancy. The compounds were all prepared and isolated in analytical purity and in good yield (95%). Epoxy samples were prepared, individually incorporating each compound. Thermogravimetric analysis showed an increased char yield, indicating an improved thermal resistance (with respect to the control sample). Limiting oxygen index for the control polymer was 28.0% ± 0.31% and it increased to 34.6% ± 0.33% for the fluorinated derivative

Environmental considerations are motivating the adoption of low global warming potential refrigerants. Most of these are mildly flammable, i.e., A2L. Their susceptibility to ignition from various ignition sources is poorly understood, particularly for the stoichiometric and quiescent mixtures that are emphasized here. The viability of fifteen residential ignition sources to ignite four A2L refrigerants is considered. Tests are performed in a windowed chamber with a volume of 26 L. The refrigerants are R-32 (difluoromethane); R-452B (67% R-32, 26% R-1234yf, and 7% pentafluoroethane); R-1234yf (2,3,3,3-tetrafluoropropene); and R-1234ze (1,3,3,3-tetrafluoropropene). Two types of ignition sources are confirmed here to be viable: a resistively heated wire at 740 °C and open flames. When the refrigerant concentration was increased slowly, candle flames and butane flames extinguished before initiating any large deflagrations. Eleven other sources were not viable: a smoldering cigarette, a butane lighter, friction sparks, a plug and receptacle, a light switch, a hand mixer, a cordless drill, a bread toaster, a hair dryer, a hot plate, and a space heater. The difficulty to ignite these refrigerants in air is attributed to their long quenching distances (up to 25 mm). Under some conditions the refrigerants were observed to act as flame suppressants.

Fire behaviour research has largely focused on dry ecosystems that burn frequently, with far less attention on wetter forests. Yet, the impacts of fire in wet forests can be high and therefore understanding the drivers of fire in these systems is vital.

Flammability studies of electrolytes are required for screening safer materials used in lithium-ion batteries. Besides the thermal stability, the effects of lithium salts on electrolyte combustion are important as well for fire safety of electrolytes. To clarify the influence of lithium salts on the electrolyte flammability, experimental analyses were conducted using a unique wick combustion system in conjunction with the limiting oxygen concentration (LOC) test, called wick-LOC method. The dimethyl carbonate (DMC)-based electrolytes with 1M addition of different lithium salts (LiPF6, LiBF4, and LiTFSI) were studied comparing with pure DMC and trimethyl phosphate (TMP)-added solvents. The three lithium salts gave unique and distinct flame behaviors including flame shapes, colors and the changes of wick surface until self-extinguishing. The wick-LOC results indicated a considerable flame-retardant effect of LiPF6, while other salts have minor effects on the flame extinction. Utilizing the flame spectrum and combustion residue analyses, the roles of salts during combustion were characterized. The PF6 anion played a similar role with the TMP additive in the gas phase flame inhibition. In the cases of LiPF6 and LiBF4, the solid products (LiF) accumulation blocked the fuel supply from the wick to the flame region. In the case of LiTFSI, the serious charring of the cotton wick was considered as a potential hazard on solid combustibles in the real fire scenarios.

Flammability studies of electrolytes are required for screening safer materials used in lithium-ion batteries. Besides the thermal stability, the effects of lithium salts on electrolyte combustion are important as well for fire safety of electrolytes. To clarify the influence of lithium salts on the electrolyte flammability, experimental analyses were conducted using a unique wick combustion system in conjunction with the limiting oxygen concentration (LOC) test, called wick-LOC method. The dimethyl carbonate (DMC)-based electrolytes with 1M addition of different lithium salts (LiPF6, LiBF4, and LiTFSI) were studied comparing with pure DMC and trimethyl phosphate (TMP)-added solvents. The three lithium salts gave unique and distinct flame behaviors including flame shapes, colors and the changes of wick surface until self-extinguishing. The wick-LOC results indicated a considerable flame-retardant effect of LiPF6, while other salts have minor effects on the flame extinction. Utilizing the flame spectrum and combustion residue analyses, the roles of salts during combustion were characterized. The PF6 anion played a similar role with the TMP additive in the gas phase flame inhibition. In the cases of LiPF6 and LiBF4, the solid products (LiF) accumulation blocked the fuel supply from the wick to the flame region. In the case of LiTFSI, the serious charring of the cotton wick was considered as a potential hazard on solid combustibles in the real fire scenarios.

Assessing the fire risk of vegetated roofs includes the determination of their possible contribution to fire. Green roof components such as plants and growing media are organic materials and present a fuel that can catch and support the spread of fire. The flammability characteristics of these components were analyzed and compared to a typical roof covering. Growing media with 15% of organic matter were tested using cone calorimeter apparatus. The fuel load and heat release rate of the growing media were measured in both moist (30%) and dry conditions. It was observed that growing media in a moist condition do not present a fire risk, reaching a maximum heat release rate of 33 kW/m2. For dry substrates, a peak heat release rate of 95 kW/m2 was recorded in the first minute, which then rapidly decreased to 29 kW/m2 in the second minute. Compared to a typical bitumen roof membrane, the green roof showed a better fire performance. The literature data report more severe results for plant behavior, reaching peak heat release rates (HRRs) of 397 kW/m2 for dried and 176 kW/m2 for a green material. However, a rapid decrease in HRR to much lower values occurs in less than 2 min. The results also show that extensive and intensive types of green roofs present 22% and 95% of the additional fire load density when installed on a modified bitumen membrane, 19.7 and 85.8 MJ/m2, respectively.

[EN] Ethyl alcohol (ethanol) as secondary fluids is very popular as heat transfer fluid for indirect refrigeration system with ground source heat pump systems (GSHP) in several countries such as Sweden, Norway, Switzerland, Finland and other European countries. There have been several researches about the future of the refrigeration sector, refrigerants and refrigeration systems. Moreover, strict regulations such as F-gas regulation and Kigali Amendment forcing a phase down of many current widely used high global warming potential (GWP) refrigerants, i.e. R134a or R410A. Therefore, secondary refrigeration systems and their working fluids are expected to play a key role in order to minimize the refrigerant charge in the systems, reduce the indirect refrigerant leakages as well as increase the safety during operation. The aim of this thesis is to investigate the effect different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol water solutions. The study aims to design a new commercial ethyl alcoholbased product for GSHP system that could replace existing ones in the Swedish market and could work with natural or flammable low GWP refrigerants. Different high flash point additives were tested such as 1-propyl alcohol, n-butyl alcohol, glycerol and propylene carbonate. Thermophysical properties were investigated and a GSHP model in Excel was created in order to assess the energy performance of the resulted blends. After screening different blends and assessing the energy performance, glycerol as additive in low concentration seems to be the future for the ethyl alcohol-based secondary fluids because of its high flash point (160ºC) that will reduce the flammability risk associated to ethyl alcohol blends, the low viscosity (by 12% lower compared to pure ethyl alcohol blends) that help reduce pumping power by 4.5% compared to pure ethyl al, [ES] Posibilidades para solucionar los desafíos son el usode sistemas indirectos para sistemas de bomba de calor geotérmicas y la búsqueda de fluidos secundarios alternativos. Suecia es el lider en sistemas de bomba de calor de suelo y utilización de energía geotérmica en Europa (Gehlin, Andersson 2016), para las cuales calefacción y refrigeración en edificios son los principales propositos. Entre las opciones, los fluidos secundarios de base ethanol son los fluidos secundarios más comunes en Suecia y otros países escandinavos debido a sus propiedades termofísicas relativamente buenas (Ignatowicz, Mazzotti, Melinder, Palm 2017a). Sin embargo, estos fluidos no pueden exceder 30% en concentración en peso correspondiente a temperatura de congelación de -20.5 ºC por riesgo de inflamación (Melinder 2008). Además, los productos de base etanol comercialmente disponibles en Suecia son distribuidos como 90-95% concentración de etanol, incluyendo hasta un 12% de agentes desanaturalizante sin inhibidores de corrosión. La regulación de la Unión Europea estrictamente define el tipo y concentración de estos agentes usados para evitar que sean ingeridos (Ignatowicz, Mazzotti, Melinder, Palm 2017b). (Ignatowicz, Acuña, Melinder, Palm 2015), (Ignatowicz, Melinder, Palm 2016) and (Ignatowicz, Mazzotti, Melinder, Palm 2017a) muestran que la presencia de estos agentes desnaturalizantes definitivamente mejoran el rendimiento térmico pero no cambian el punto de llama. Por lo tanto, se plantean preguntas sobre si otros aditivos pueden utilizarse junto a etanol para aumentar el punto de llama para que puedan ser usados con otros refrigerantes naturales e inflamables. El objetivo de este Trabajo Final de Master es investigar el efecto de diferentes aditivos para incrementar el punto de llama de fluidos secundarios de base etanol y validar sus propiedades termofísicas comparándolas con valores de referencia mezclas de etanol puro con agua y comerciales. El estudio tiene como objetivo el dise, [EN] Possibilities to overcome the trial are the use of indirect systems for GSHPs and the search for alternative secondary fluids. Sweden is the leader in GSHP systems and geothermal energy utilization in Europe (Gehlin, Andersson 2016), where heating and cooling in buildings are one of the main purposes. Among other options, ethanol-based secondary fluids are the most common secondary fluids in Sweden and other Scandinavian countries due to their relative good thermophysical properties (Ignatowicz, Mazzotti, Melinder, Palm 2017a). Nevertheless, these fluids are usually not exceeding 30 wt-%, corresponding to a freezing point of -20.5 ºC due to safety regulations and flammability risks (Melinder 2008). In addition, the commercially available ethanol-based products in Sweden are distributed as 90 - 95 wt-% ethanol concentrate, including up to 12 wt-% of denaturing agents but no corrosion inhibitors. European Union regulations strictly define the types and concentrations of the denaturing agents used to prevent from drinking (Ignatowicz, Mazzotti, Melinder, Palm 2017b). (Ignatowicz, Acuña, Melinder, Palm 2015), (Ignatowicz, Melinder, Palm 2016) and (Ignatowicz, Mazzotti, Melinder, Palm 2017a) showed that the presence of denaturing agents definitely improves the thermal performance of ethanol-based secondary fluids but do not change the flame point. Therefore, a question is being raised if other additives could be used together with ethanol in order to rise the flame point so they can be used with natural and flammable refrigerants. The aim of this MSc thesis is to investigate the effect of different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol-water solutions and commercially available ones. The study aims to design a new commercial for GSHP system that could replace existing ones in the Swedish market.

[EN] Ethyl alcohol (ethanol) as secondary fluids is very popular as heat transfer fluid for indirect refrigeration system with ground source heat pump systems (GSHP) in several countries such as Sweden, Norway, Switzerland, Finland and other European countries. There have been several researches about the future of the refrigeration sector, refrigerants and refrigeration systems. Moreover, strict regulations such as F-gas regulation and Kigali Amendment forcing a phase down of many current widely used high global warming potential (GWP) refrigerants, i.e. R134a or R410A. Therefore, secondary refrigeration systems and their working fluids are expected to play a key role in order to minimize the refrigerant charge in the systems, reduce the indirect refrigerant leakages as well as increase the safety during operation. The aim of this thesis is to investigate the effect different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol water solutions. The study aims to design a new commercial ethyl alcoholbased product for GSHP system that could replace existing ones in the Swedish market and could work with natural or flammable low GWP refrigerants. Different high flash point additives were tested such as 1-propyl alcohol, n-butyl alcohol, glycerol and propylene carbonate. Thermophysical properties were investigated and a GSHP model in Excel was created in order to assess the energy performance of the resulted blends. After screening different blends and assessing the energy performance, glycerol as additive in low concentration seems to be the future for the ethyl alcohol-based secondary fluids because of its high flash point (160ºC) that will reduce the flammability risk associated to ethyl alcohol blends, the low viscosity (by 12% lower compared to pure ethyl alcohol blends) that help reduce pumping power by 4.5% compared to pure ethyl al, [ES] Posibilidades para solucionar los desafíos son el usode sistemas indirectos para sistemas de bomba de calor geotérmicas y la búsqueda de fluidos secundarios alternativos. Suecia es el lider en sistemas de bomba de calor de suelo y utilización de energía geotérmica en Europa (Gehlin, Andersson 2016), para las cuales calefacción y refrigeración en edificios son los principales propositos. Entre las opciones, los fluidos secundarios de base ethanol son los fluidos secundarios más comunes en Suecia y otros países escandinavos debido a sus propiedades termofísicas relativamente buenas (Ignatowicz, Mazzotti, Melinder, Palm 2017a). Sin embargo, estos fluidos no pueden exceder 30% en concentración en peso correspondiente a temperatura de congelación de -20.5 ºC por riesgo de inflamación (Melinder 2008). Además, los productos de base etanol comercialmente disponibles en Suecia son distribuidos como 90-95% concentración de etanol, incluyendo hasta un 12% de agentes desanaturalizante sin inhibidores de corrosión. La regulación de la Unión Europea estrictamente define el tipo y concentración de estos agentes usados para evitar que sean ingeridos (Ignatowicz, Mazzotti, Melinder, Palm 2017b). (Ignatowicz, Acuña, Melinder, Palm 2015), (Ignatowicz, Melinder, Palm 2016) and (Ignatowicz, Mazzotti, Melinder, Palm 2017a) muestran que la presencia de estos agentes desnaturalizantes definitivamente mejoran el rendimiento térmico pero no cambian el punto de llama. Por lo tanto, se plantean preguntas sobre si otros aditivos pueden utilizarse junto a etanol para aumentar el punto de llama para que puedan ser usados con otros refrigerantes naturales e inflamables. El objetivo de este Trabajo Final de Master es investigar el efecto de diferentes aditivos para incrementar el punto de llama de fluidos secundarios de base etanol y validar sus propiedades termofísicas comparándolas con valores de referencia mezclas de etanol puro con agua y comerciales. El estudio tiene como objetivo el dise, [EN] Possibilities to overcome the trial are the use of indirect systems for GSHPs and the search for alternative secondary fluids. Sweden is the leader in GSHP systems and geothermal energy utilization in Europe (Gehlin, Andersson 2016), where heating and cooling in buildings are one of the main purposes. Among other options, ethanol-based secondary fluids are the most common secondary fluids in Sweden and other Scandinavian countries due to their relative good thermophysical properties (Ignatowicz, Mazzotti, Melinder, Palm 2017a). Nevertheless, these fluids are usually not exceeding 30 wt-%, corresponding to a freezing point of -20.5 ºC due to safety regulations and flammability risks (Melinder 2008). In addition, the commercially available ethanol-based products in Sweden are distributed as 90 - 95 wt-% ethanol concentrate, including up to 12 wt-% of denaturing agents but no corrosion inhibitors. European Union regulations strictly define the types and concentrations of the denaturing agents used to prevent from drinking (Ignatowicz, Mazzotti, Melinder, Palm 2017b). (Ignatowicz, Acuña, Melinder, Palm 2015), (Ignatowicz, Melinder, Palm 2016) and (Ignatowicz, Mazzotti, Melinder, Palm 2017a) showed that the presence of denaturing agents definitely improves the thermal performance of ethanol-based secondary fluids but do not change the flame point. Therefore, a question is being raised if other additives could be used together with ethanol in order to rise the flame point so they can be used with natural and flammable refrigerants. The aim of this MSc thesis is to investigate the effect of different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol-water solutions and commercially available ones. The study aims to design a new commercial for GSHP system that could replace existing ones in the Swedish market.

Assessing the fire risk of vegetated roofs includes the determination of their possible contribution to fire. Green roof components such as plants and growing media are organic materials and present a fuel that can catch and support the spread of fire. The flammability characteristics of these components were analyzed and compared to a typical roof covering. Growing media with 15% of organic matter were tested using cone calorimeter apparatus. The fuel load and heat release rate of the growing media were measured in both moist (30%) and dry conditions. It was observed that growing media in a moist condition do not present a fire risk, reaching a maximum heat release rate of 33 kW/m2. For dry substrates, a peak heat release rate of 95 kW/m2 was recorded in the first minute, which then rapidly decreased to 29 kW/m2 in the second minute. Compared to a typical bitumen roof membrane, the green roof showed a better fire performance. The literature data report more severe results for plant behavior, reaching peak heat release rates (HRRs) of 397 kW/m2 for dried and 176 kW/m2 for a green material. However, a rapid decrease in HRR to much lower values occurs in less than 2 min. The results also show that extensive and intensive types of green roofs present 22% and 95% of the additional fire load density when installed on a modified bitumen membrane, 19.7 and 85.8 MJ/m2, respectively.

[EN] Ethyl alcohol (ethanol) as secondary fluids is very popular as heat transfer fluid for indirect refrigeration system with ground source heat pump systems (GSHP) in several countries such as Sweden, Norway, Switzerland, Finland and other European countries. There have been several researches about the future of the refrigeration sector, refrigerants and refrigeration systems. Moreover, strict regulations such as F-gas regulation and Kigali Amendment forcing a phase down of many current widely used high global warming potential (GWP) refrigerants, i.e. R134a or R410A. Therefore, secondary refrigeration systems and their working fluids are expected to play a key role in order to minimize the refrigerant charge in the systems, reduce the indirect refrigerant leakages as well as increase the safety during operation. The aim of this thesis is to investigate the effect different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol water solutions. The study aims to design a new commercial ethyl alcoholbased product for GSHP system that could replace existing ones in the Swedish market and could work with natural or flammable low GWP refrigerants. Different high flash point additives were tested such as 1-propyl alcohol, n-butyl alcohol, glycerol and propylene carbonate. Thermophysical properties were investigated and a GSHP model in Excel was created in order to assess the energy performance of the resulted blends. After screening different blends and assessing the energy performance, glycerol as additive in low concentration seems to be the future for the ethyl alcohol-based secondary fluids because of its high flash point (160ºC) that will reduce the flammability risk associated to ethyl alcohol blends, the low viscosity (by 12% lower compared to pure ethyl alcohol blends) that help reduce pumping power by 4.5% compared to pure ethyl al, [ES] Posibilidades para solucionar los desafíos son el usode sistemas indirectos para sistemas de bomba de calor geotérmicas y la búsqueda de fluidos secundarios alternativos. Suecia es el lider en sistemas de bomba de calor de suelo y utilización de energía geotérmica en Europa (Gehlin, Andersson 2016), para las cuales calefacción y refrigeración en edificios son los principales propositos. Entre las opciones, los fluidos secundarios de base ethanol son los fluidos secundarios más comunes en Suecia y otros países escandinavos debido a sus propiedades termofísicas relativamente buenas (Ignatowicz, Mazzotti, Melinder, Palm 2017a). Sin embargo, estos fluidos no pueden exceder 30% en concentración en peso correspondiente a temperatura de congelación de -20.5 ºC por riesgo de inflamación (Melinder 2008). Además, los productos de base etanol comercialmente disponibles en Suecia son distribuidos como 90-95% concentración de etanol, incluyendo hasta un 12% de agentes desanaturalizante sin inhibidores de corrosión. La regulación de la Unión Europea estrictamente define el tipo y concentración de estos agentes usados para evitar que sean ingeridos (Ignatowicz, Mazzotti, Melinder, Palm 2017b). (Ignatowicz, Acuña, Melinder, Palm 2015), (Ignatowicz, Melinder, Palm 2016) and (Ignatowicz, Mazzotti, Melinder, Palm 2017a) muestran que la presencia de estos agentes desnaturalizantes definitivamente mejoran el rendimiento térmico pero no cambian el punto de llama. Por lo tanto, se plantean preguntas sobre si otros aditivos pueden utilizarse junto a etanol para aumentar el punto de llama para que puedan ser usados con otros refrigerantes naturales e inflamables. El objetivo de este Trabajo Final de Master es investigar el efecto de diferentes aditivos para incrementar el punto de llama de fluidos secundarios de base etanol y validar sus propiedades termofísicas comparándolas con valores de referencia mezclas de etanol puro con agua y comerciales. El estudio tiene como objetivo el dise, [EN] Possibilities to overcome the trial are the use of indirect systems for GSHPs and the search for alternative secondary fluids. Sweden is the leader in GSHP systems and geothermal energy utilization in Europe (Gehlin, Andersson 2016), where heating and cooling in buildings are one of the main purposes. Among other options, ethanol-based secondary fluids are the most common secondary fluids in Sweden and other Scandinavian countries due to their relative good thermophysical properties (Ignatowicz, Mazzotti, Melinder, Palm 2017a). Nevertheless, these fluids are usually not exceeding 30 wt-%, corresponding to a freezing point of -20.5 ºC due to safety regulations and flammability risks (Melinder 2008). In addition, the commercially available ethanol-based products in Sweden are distributed as 90 - 95 wt-% ethanol concentrate, including up to 12 wt-% of denaturing agents but no corrosion inhibitors. European Union regulations strictly define the types and concentrations of the denaturing agents used to prevent from drinking (Ignatowicz, Mazzotti, Melinder, Palm 2017b). (Ignatowicz, Acuña, Melinder, Palm 2015), (Ignatowicz, Melinder, Palm 2016) and (Ignatowicz, Mazzotti, Melinder, Palm 2017a) showed that the presence of denaturing agents definitely improves the thermal performance of ethanol-based secondary fluids but do not change the flame point. Therefore, a question is being raised if other additives could be used together with ethanol in order to rise the flame point so they can be used with natural and flammable refrigerants. The aim of this MSc thesis is to investigate the effect of different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol-water solutions and commercially available ones. The study aims to design a new commercial for GSHP system that could replace existing ones in the Swedish market.

Serotiny is the prolonged storage of seeds in closed cones or fruits held within the crown of woody plants. It is widespread throughout fireprone vegetation with a predominantly winter rainfall, especially in Mediterrnanean-type ecosystems (MTEs). Nonstorage is a feature of fireprone vegetation with summer-dominant rainfall or nonfireprone vegetation. Serotiny confers fitness benefits on an individual when fire return intervals fall between age to reproductive maturity and the plant life span. The level of serotiny within and between species varies greatly along a continuum indicating highly plastic responses to different environmental conditions. Here we review how and why the traits that underpin this reproductive syndrome evolved and continue to control the occurrence of species in contemporary landscapes. We documented 1345 serotinous species in fireprone regions of Australia, South Africa, the Mediterranean Basin, North America, and Asia. The length of seed storage varies from a few years (weak serotiny) to >10 years (strong serotiny), with remarkable diversity even within clades. We show how the interplay between postfire and interfire seedling recruitment dictates the expression of serotiny along a strong serotiny/nonserotiny continuum, and that, where strong serotiny is favored, the ‘gene support for serotiny’ builds up over successive generations. Nonserotiny is favored in the absence of fire or occurs at intervals exceeding plant longevity, but also when the fire is so frequent that only resprouters can survive. We identify 23 traits associated with serotiny/nonserotiny syndromes that are subject to both environmental and phylogenetic constraints. While all are coordinated for maximum fitness, some traits, such as protection from granivores, are only indirectly related to the fire regime. Serotiny has a long history extending back to the Triassic. The rate of serotinous-lineage proliferation has fluctuated greatly over time but peaked over the last 5 milli

Aims: Tree species can affect litter flammability through leaf size and shape. Larger, simpler-shaped leaf litters form better-ventilated, more flammable litter-beds. However, leaves are generally mixed with twigs in the forest litter layer and together they likely contribute most to surface fire behavior. Here we ask: “Do leaf-twig mixtures have non-additive effects on litter-bed flammability?” Methods: Using laboratory fires, we tested the direction and magnitude of non-additivity of inter- and intra-specific leaf-twig mixtures on litter-bed flammability for four tree species contrasted in leaf size and shape and widespread in fire-prone temperate-boreal forests. Results: Across species, small needles reduced mixture fuel-bed ignitibility through filling the space between twigs and inhibiting ventilation. Within the small broad-leaved species, the thin, frequently branched and open spaced twigs were too loosely packed to be flammable, while in mixtures the small broad leaves connected these twigs to produce flammable fuel-beds. Once ignited, across species flame spread rate in mixtures was driven by leaves, while fire sustainability was predicted by fuel mass. Fuel-bed flammability was driven more by leaves at larger leaf-to-twig ratio. Conclusions: For the first time, we demonstrated the existence and mechanisms of non-additive effects of leaf-twig mixtures on experimental litter-bed flammability.

The objective of this study is to assess the efficiency of biobased carbonization agent in intumescent formulations (IFRs) to examine the flame retardant properties of polylactic acid (PLA) composites and to investigate their melt-spinnability. We used phosphorous-based halogen free flame retardant (FR) and kraft lignin (KL) as bio-based carbonization agent. After melt compounding and molding into sheets by hot pressing various fire related characteristics of IFR composites were inspected and were characterized by different characterization methods. It was fascinating to discover that the introduction of 5-20 wt% FR increased the limiting oxygen index (LOI) of PLA composites from 20.1% to 23.2-33.5%. The addition of KL with content of 3-5 wt% further increased the LOI up to 36.6-37.8% and also endowed PLA/FR/KL composites with improved anti-dripping properties. Cone calorimetry revealed a 50% reduction in the peak heat release rate of the IFR composites in comparison to 100% PLA and confirmed the development of an intumescent char structure containing residue up to 40%. For comparative study, IFR composites containing pentaerythritol (PER) as a carbonization agent were also prepared and their FR properties were compared. IFR composites were melt spun and mechanical properties of multifilament yarns were tested. The analysis of char residues by energy dispersive X-ray spectrometry (EDS) and SEM images confirmed that PLA/FR/KL composites developed a thicker and more homogeneous char layer with better flame retardant properties confirming that the fire properties of PLA can be enhanced by using KL as a carbonization agent.

Fire is the most frequent disturbance in the Ericaceous Belt (ca 3000-1300 m.a.s.l.), one of the most important plant communities of tropical African mountains. Through resprouting after fire, Erica establishes a positive fire feedback under certain burning regimes. However, present-day human activity in the Bale Mountains of Ethiopia includes fire and grating systems that may have a negative impact on the resilience of the ericaceous ecosystem. Current knowledge of Erica-fire relationships is based on studies of modern vegetation, lacking a longer time perspective that can shed light on baseline conditions for the fire feedback. We hypothesite that fire has influenced Erica communities in the Bale Mountains at millennial time-scales. To test this, we (1) identity the tire history ot the Bale Mountains through a pollen and charcoal record from Garba Guracha, a lake at 3950 m.a.s.l., and (2) describe the long-term bidirectional feedback between wildfire and Erica, which may control the ecosystem's resilience. Our results support fire occurrence in the area since ca 14 000 years ago, with particularly intense burning during the early Holocene, 10.8-6.0 cal ka BP. We show that a positive feedback between Erica abundance and fire occurrence was in operation throughout the Lateglacial and Holocene, and interpret the Ericaceous Bolt of the Ethiopian mountains as a long-term fire resilient ecosystem. We propose that controlled burning should be an integral part of landscape management in the Bale Mountains National Park.

Ethyl alcohol (ethanol) as secondary fluids is very popular as heat transfer fluid for indirect refrigeration system with ground source heat pump systems (GSHP) in several countries such as Sweden, Norway, Switzerland, Finland and other European countries. There have been several researches about the future ofthe refrigeration sector, refrigerants and refrigeration systems. Moreover, strict regulations such as F-gasregulation and Kigali Amendment forcing a phase down of many current widely used high global warming potential (GWP) refrigerants, i.e. R134a or R410A. Therefore, secondary refrigeration systems and their working fluids are expected to play a key role in order to minimize the refrigerant charge in the systems, reduce the indirect refrigerant leakages as well as increase the safety during operation. The aim of this thesis is to investigate the effect different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol water solutions. The study aims to design a new commercial ethyl alcohol-based product for GSHP system that could replace existing ones in the Swedish market and could workwith natural or flammable low GWP refrigerants. Different high flash point additives were tested such as 1-propyl alcohol, n-butyl alcohol, glycerol andpropylene carbonate. Thermophysical properties were investigated and a GSHP model in Excel was created in order to assess the energy performance of the resulted blends. After screening different blends and assessing the energy performance, glycerol as additive in low concentration seems to be the future for the ethyl alcohol-based secondary fluids because of its high flashpoint (160ºC) that will reduce the flammability risk associated to ethyl alcohol blends, the low viscosity (by 12% lower compared to pure ethyl alcohol blends) that help reduce pumping power by 4.5% compared topure ethyl alcohol blen, Etylalkohol (etanol) som köldbärare är mycket populärt som värmeöverföringsvätska för indirekt kylsystemmed bergvärmepumpsystem (BVP) i Sverige, Norge, Schweiz, Finland och andra europeiska länder. Fleraundersökningar har gjorts om kylsektorns framtid, köldmedier och kylsystem. Dessutom strängaförordningar som F-gas förordning och Kigali- förordning tvingar en utfasning av många nuvarande allmäntanvända köldmedier med den höga globala uppvärmningspotentialen (GWP), dvs. R134a eller R410A. Därför förväntas det att kylsystem och deras köldbärare spela en nyckelroll för att minimera köldmediumsmängd i systemen, minska de indirekta köldmedieläckage och öka säkerheten under drift. Syftet med detta examensarbete är att undersöka effekten av olika tillsatser för att öka flammanpunkten tillsammans med etanolbaserade köldbärare och validera deras termofysikaliska egenskaper genom att jämföra dem med referensvärden för rena etanolvattenlösningar. Studien syftar till att utforma en nykommersiell etylalkoholbaserad produkt för BVP-system som skulle kunna ersätta befintliga produkter på den svenska marknaden och kan arbeta med naturliga eller brandfarliga köldmedier med låg GWP. Olika tillsatser med hög flampunkt testades såsom 1-propylalkohol, n-butylalkohol, glycerol och propylenkarbonat. Termofysikaliska egenskaper undersöktes och en BVP-modell i Excel skapades för att bedöma energiprestanda för olika blandningarna. De erhållna resultaten för olika blandningar visar att glycerol i en låg koncentration som tillsats kan vara framtidens additiv för de etylalkoholbaserade köldbärare på grund av dess höga flampunkt (160 ºC) som förmodligen kan minska brandrisken för etylalkoholblandningar. Dessutom hade glycerol och etanolblandningar den lägsta viskositeten (c.a.12% lägre jämfört med ren etylalkoholblandningar) som bidrar tillen minskning av pumpeffekten med c.a. 4,5% jämfört med rena etylalkoholblandningar. Däremot visade etylalkohol och glycerol blandningen c.a. 4% lägre värmeöv

Ethyl alcohol (ethanol) as secondary fluids is very popular as heat transfer fluid for indirect refrigeration system with ground source heat pump systems (GSHP) in several countries such as Sweden, Norway, Switzerland, Finland and other European countries. There have been several researches about the future ofthe refrigeration sector, refrigerants and refrigeration systems. Moreover, strict regulations such as F-gasregulation and Kigali Amendment forcing a phase down of many current widely used high global warming potential (GWP) refrigerants, i.e. R134a or R410A. Therefore, secondary refrigeration systems and their working fluids are expected to play a key role in order to minimize the refrigerant charge in the systems, reduce the indirect refrigerant leakages as well as increase the safety during operation. The aim of this thesis is to investigate the effect different additives to increase the flame point together with ethanol-based secondary fluids and validate their thermophysical properties by comparing them with reference values for pure ethanol water solutions. The study aims to design a new commercial ethyl alcohol-based product for GSHP system that could replace existing ones in the Swedish market and could workwith natural or flammable low GWP refrigerants. Different high flash point additives were tested such as 1-propyl alcohol, n-butyl alcohol, glycerol andpropylene carbonate. Thermophysical properties were investigated and a GSHP model in Excel was created in order to assess the energy performance of the resulted blends. After screening different blends and assessing the energy performance, glycerol as additive in low concentration seems to be the future for the ethyl alcohol-based secondary fluids because of its high flashpoint (160ºC) that will reduce the flammability risk associated to ethyl alcohol blends, the low viscosity (by 12% lower compared to pure ethyl alcohol blends) that help reduce pumping power by 4.5% compared topure ethyl alcohol blen, Etylalkohol (etanol) som köldbärare är mycket populärt som värmeöverföringsvätska för indirekt kylsystemmed bergvärmepumpsystem (BVP) i Sverige, Norge, Schweiz, Finland och andra europeiska länder. Fleraundersökningar har gjorts om kylsektorns framtid, köldmedier och kylsystem. Dessutom strängaförordningar som F-gas förordning och Kigali- förordning tvingar en utfasning av många nuvarande allmäntanvända köldmedier med den höga globala uppvärmningspotentialen (GWP), dvs. R134a eller R410A. Därför förväntas det att kylsystem och deras köldbärare spela en nyckelroll för att minimera köldmediumsmängd i systemen, minska de indirekta köldmedieläckage och öka säkerheten under drift. Syftet med detta examensarbete är att undersöka effekten av olika tillsatser för att öka flammanpunkten tillsammans med etanolbaserade köldbärare och validera deras termofysikaliska egenskaper genom att jämföra dem med referensvärden för rena etanolvattenlösningar. Studien syftar till att utforma en nykommersiell etylalkoholbaserad produkt för BVP-system som skulle kunna ersätta befintliga produkter på den svenska marknaden och kan arbeta med naturliga eller brandfarliga köldmedier med låg GWP. Olika tillsatser med hög flampunkt testades såsom 1-propylalkohol, n-butylalkohol, glycerol och propylenkarbonat. Termofysikaliska egenskaper undersöktes och en BVP-modell i Excel skapades för att bedöma energiprestanda för olika blandningarna. De erhållna resultaten för olika blandningar visar att glycerol i en låg koncentration som tillsats kan vara framtidens additiv för de etylalkoholbaserade köldbärare på grund av dess höga flampunkt (160 ºC) som förmodligen kan minska brandrisken för etylalkoholblandningar. Dessutom hade glycerol och etanolblandningar den lägsta viskositeten (c.a.12% lägre jämfört med ren etylalkoholblandningar) som bidrar tillen minskning av pumpeffekten med c.a. 4,5% jämfört med rena etylalkoholblandningar. Däremot visade etylalkohol och glycerol blandningen c.a. 4% lägre värmeöv

Wood is a widely used material in the construction sector, both in structural and non-structural applications. Tropical species are appreciated for their high quality and durability in furniture, outdoor and indoor claddings and floors. However, limited information exists about fire reaction of tropical wood. Density is one of the factors that influence the rate of pyrolysis reactions and consequently the charring rate. However, other wood characteristics such as the mineral content also exert an influence on the pyrolysis combustion of wood. Hardwoods present a complex morphological structure and a significant amount of minerals, extracts and exudates. In this work, we study the fire reaction of seven species of tropical hardwood using various fire tests. Results are compared from one test to other one and are discussed in relation with physicochemical properties of wood species. The results show that although there is some correlation between high density and ignition time, parameters such as morphology and mineral content are also relevant., Peer Reviewed, Preprint

The Burning Rate Emulator (BRE) is a device constructed to emulate condensed fuels using gaseous fuel mixtures by matching heat of combustion, heat of gasification, smoke point, and surface temperature. The burner’s heat flux gauges are calibrated for local heat flux measurements and the copper top-plate calorimeter is calibrated for measuring net heat flux to the surface, which allows for determination of an effective heat of gasification to compare to condensed fuels. Seven condensed fuels with known properties are burned and emulated using methane, ethylene, and propylene gas diluted with nitrogen. Propane gas is used to study the general pool fire characteristics displayed by gaseous flames on the BRE. Flame anchoring, flammability regions, flame height, and convective heat transfer are analyzed. Based on a radial heat flux distribution, the readings from the heat flux sensors agree with the calorimeter when applied to a flame. Example flame images are shown.

The flammability of combustible materials inside a spacecraft environment is of importance for fire safety applications because the conditions in this type of environments can greatly differ from those on earth, and a fire could have catastrophic consequences. Moreover, experimental testing in space can be difficult and expensive, and ground-based microgravity facilities such as drop towers or parabolic flights are limited to a few second duration. Additionally, future space missions may require spacecraft cabin environments different than those currently used in the International Space Station, 21% O2 by volume and 101.3 kPa, moving to reduced cabin pressure and increased oxygen concentration. These new conditions may result in an increased fire risk of the materials used due to the higher flame temperatures and the reduction in the convective losses from the heated solid surfaces. In particular, the influence of low pressure on material flammability and flame spread behavior is emphasized here because of the similarities existing in between the flow field produced in reduced pressure environments and microgravity.Chapter 1 presents an introduction to material flammability and flammability testing, focusing particularly on flame spread over solid fuels and previous related research. Chapter 2 presents a description of the experimental setups used for the normal gravity and the microgravity tests presented as part of this work. Chapter 3 is an experimental study covering flammability boundaries for flame spread of fire resistant fabrics exposed to different environmental conditions. In Chapter 4 and 5, an experimental study is presented along with a phenomenological analysis to simulate the burning behavior of thin and thick solids in microgravity conditions by using reduced pressure environments. Then, in Chapter 6 a similar approach is presented to study the flame spread behavior under the effect of external radiant heating, making comparisons with low pressure an

Different scale tests to explore the influence of fiberglass mesh on the fire behavior of expanded polystyrene (EPS) have been conducted. Micro scale combustion calorimeter to measure the heat release rate per unit mass, heat release capacity, and the total heat release of EPS and as well as the fiberglass for milligram specimen mass has been used. Cone colorimeter bench scale burning tests with the EPS specimens and EPS-fiberglass compound specimens have been carried out. The heat release rate per unit area, ignition times, and the derived minimum igniting heat fluxes were determined. Comparative burning tests on the fire spread tendency of EPS and EPS-fiberglass compound specimens have been carried out. It was established that the fiberglass mesh stabilizes the EPS fire as a wick fire due to the adherence of the melting polystyrene adheres to the fiberglass mesh and this causes an upwards fire spread.

R404A will be soon restricted from usage in commercial refrigeration in the European Union (EU) due to the requirements of the EU Regulation on fluorinated gases. Therefore, new refrigerant HFO/HFC mixtures are being developed to replace it. This paper explores the R454C and R455A as R404A alternatives and compares the characteristics that can lead their imposition in the refrigeration market. The characteristics studied are components and composition, current penetration in the market, security issues, global warming potential, energetic performance, material and lubricant compatibility and, finally, most likely applications., QC 20180601

Different scale tests to explore the influence of fiberglass mesh on the fire behavior of expanded polystyrene (EPS) have been conducted. Micro scale combustion calorimeter to measure the heat release rate per unit mass, heat release capacity, and the total heat release of EPS and as well as the fiberglass for milligram specimen mass has been used. Cone colorimeter bench scale burning tests with the EPS specimens and EPS-fiberglass compound specimens have been carried out. The heat release rate per unit area, ignition times, and the derived minimum igniting heat fluxes were determined. Comparative burning tests on the fire spread tendency of EPS and EPS-fiberglass compound specimens have been carried out. It was established that the fiberglass mesh stabilizes the EPS fire as a wick fire due to the adherence of the melting polystyrene adheres to the fiberglass mesh and this causes an upwards fire spread.