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En studie om brandegenskaper som förändras hos en träfasad som exponeras av utomhusklimatNäsholm, Jennie January 2022 (has links)
Trä som byggnadsmaterial har ökat inom byggbranschen de senaste åren. Detta på grund av att trä är ett miljövänligt och förnybart material. Dock ställer trä som byggnadsmaterial en hel del utmaningar då trä är brandkänsligt och kan behöva brandskydds-behandlas innan användning. Detta görs för att minska risken för uppkomst av brand och kan göras på två sätt, antingen genom att brandskyddsimpregnera eller flamskyddsmåla träprodukten. Den främsta uppgiften brandskyddsmedel har är i det tidiga skeendet av brand då det kan förlänga tiden till antändning. Funktionen brandskyddsbehandlingen har på träprodukten kan över tid minska och kan variera kraftigt i dess duglighet. Tillvägagångsätten för att bestämma brandskyddsbehandlade träprodukters beständighet över tid är olika och det tas kontinuerligt fram olika studier, forskning och experiment. 2017 fastställdes en europeisk standard, EN 16755, som innehåller olika bruksklasser för brandskyddets beständighet. Standard togs framför att hjälpa och ge vägledning till användare för att hitta passande brandskyddade produkter och motivera tillverkarna till att producera och leverera bra produkter.I detta arbete har flera olika studier granskats och studerats över vilka brandegenskaper som förändras när brandskyddsbehandlade träfasader exponeras för utomhusklimat. Tre studier har utfört accelererad och naturlig åldring där huvudsyftet har varit att se hur träets beständighet förändras över tid. Andra studier har studerat och testat vilka egenskaper brandhämmandekemikalier har för träprodukten. Melaminformaldehydharts, borsyra och guanylureafosfatanvänds som brandhämmande kemikalie för att nämna några. Slutsatsen drogs att brandskyddsmedel kan avsevärt förbättra brandegenskaperna genom att förlänga antändningstiden, ge högre LOI-värden och ge lägre värmeavgivningshastighet, HRR. LOI är ett syreindex som är ett index för hur mycket syre som krävs för förbränning av träet. Men över tid minskar brandskyddet och dess funktion förloras då brandskyddsmedlet lakas ut från träprodukten. En av studierna använde predikteringsmodeller för att utvärdera vilken klass träpanelerna som har utsatts för naturlig åldring har. Studien klassade träpanelerna i euroklass D eller lägre. Vilket motsvarar samma klass som obehandlade och omålade träpaneler
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Säkerställa vätgassäkerhet genom användning av hållbar glutenplast : En laborativ och teoretisk studie om egenskaper hos olika kombinationer av glutenplastAlva, Vennström January 2022 (has links)
No description available.
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Cellulose-fiber-based thermal insulation materials with fungal resistance, improved water resistance and reaction-to-fire propertiesZheng, Chao January 2017 (has links)
Thermal insulation materials made from natural fibrous materials, such as cellulose fibers, have advantages over others from a sustainability point of view. However, cellulosic materials are generally prone to mold and absorb moisture, and these have negative effects on the insulation properties, the durability of insulation materials, and interior air quality. In this thesis, cellulose-fiber-based insulation foams were prepared from bleached chemithermomechanical softwood pulp, and these foams showed promising thermal insulation properties and fungal resistance. Hydrophobic extractives were isolated from birch (Betula verrucosa) outer bark and used to improve the water resistance of the foams, which were impregnated in solutions of extractives and then dried. The modified foams showed greater water resistance, and the modification had no negative effects on the thermal insulation, fungal resistance, and compressive strength of the foams. Another potential problem with low density cellulosic thermal insulation materials is their poor reaction-to-fire properties. Cellulose-fiber-based insulation foams were prepared from formulations containing bleached chemithermomechanical softwood pulp and commercial fire retardants to improve the reaction of the foams to fire. Single-flame source test results showed that the foams containing 20% expandable graphite (20% EG) or 25% synergetic (25% SY) fire retardant had significantly improved reaction-to-fire properties and passed class E, which reflected that they can resist a small flame attack without substantial flame spreading for a short period according to EN 13501-1. Compared with the reference without any fire retardant, the peak heat release rate (Peak-HRR) of the 20% EG and 25% SY decreased by 62% and 39% respectively when the samples were subjected to a radiance heat flow of 25 kW m-2 in a Cone Calorimeter. The thesis demonstrates that it is possible to produce cellulose-fiber-based insulation materials with improved properties in terms of fungal, improved water resistance and reaction-to-fire properties. / <p>QC 20170428</p> / Energy-efficient cellulosic insulation products/panels for green building solutions
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To evaluate fire properties of a facade : - a study on semi natural test methodsMartinsson, Emma January 2018 (has links)
Due to an increase in the number of large-scale façade fires around the world the interest in the fire hazards of façades has also increased. The hazards of such fires have been acknowledged since earlier and many different test methods have therefore been developed to enable evaluation of the fire properties of wall assemblies. The purpose of this study is to map differences and similarities between existing full-scale test methods that are currently used to evaluate façade systems based on their performance when influenced by fire. The study also includes a review of previous research into parameters and conditions that influence a façade fire. Some past incidents will be used to enable comparison between the tests and a real fire scenario. The review of previous research has been focused in the areas fire spread, fire properties influencing the heat flux from a fire, and comparative studies evaluating differences between existing test methods. For the study of parameters in existing test methods 21 test methods have been identified and included in the study. A detailed compilation of information on each of the included test methods can be found in the tables included in appendix A. The mapping of the differences and similarities of the included methods has resulted in comparisons of wall and specimen specifications, ignition source parameters, measuring points and approval criteria. The increase in interest for façade fire hazards has also led to some new methods being developed and old methods being revised. New methods and unfinished revisions have not been included in the comparison study but are mentioned. The conclusion of this study is that although the variation between the tests on the detailed methodology level are very high, if you consider the conditions used for approval and evaluation, they can all be linked to identified hazards of façade fires. However, there are some parameters that need to be re-examined. Previous research indicates that the fire load may be the parameter with most influence on the fire scenario. This is one of the parameters that vary the most and at same time it is likely to contribute to different results between the test methods. Another parameter is the influence of wall openings representing windows to overlaying compartments. This is a parameter that could have a significant effect on the outcome of a test.
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Exploration de nouvelles voies pour l'ignifugation des polymères / Exploring new ways for the fire retardancy of polymersMatar, Mohamad 29 June 2016 (has links)
Dans cette étude, nous avons cherché à développer de nouvelles formulations pour améliorer la stabilité thermique et le comportement au feu de trois matrices polymères de grande diffusion: le polyéthylène (PE), le polystyrène (PS) et le polyamide 66 (PA66). Le système intumescent employé consiste à combiner des retardateurs de flammes classiques (polyphosphate d’ammonium (APP) et pentaérythritol (PER)) avec une faible quantité de nanooxydes métalliques dont les propriétés auraient été ajustées sur mesure de façon à améliorer la compatibilité du mélange à l’état fondu, ou encore pour changer le mécanisme de dégradation d’un point de vue chimique (effets catalytiques) ou physiques (effet barrière, viscosité etc…). Une partie importante de cette étude a donc été d’abord consacrée à la synthèse d’oxydes à morphologie, porosité, structure ou fonctionnalités particulières. A cet égard, les silices mésoporeuses possèdent l’avantage de présenter des surfaces spécifiques élevées (700-1400 m²/g) et une taille de pores compatible avec les chaines polymères. En adaptant les conditions de synthèse, nous avons cherché à établir des relations entre certains paramètres relatifs aux silices préparées (tels que la (1) surface spécifique (2) la taille des particules (3) la taille des pores (4) la morphologie et (5) le type de structure (en général SBA-15)) sur la stabilité thermique et le comportement au feu du polyéthylène. Préalablement, les propriétés texturales, structurales et chimiques de ces silices ont été caractérisées par porosimétrie à l’azote à 77K, DRX et FTIR. Globalement, les améliorations apportées par les silices mésostructurées restent modestes par rapport à celles induites par les RF classiques seuls et ceci particulièrement pour les polymères non charbonnants (PE et PS). Ceci est dû probablement à la très grande disparité des teneurs respectives en silice et RF dans les composites testés (1 et 24% en masse, respectivement). L’effet du taux de silice SBA-15 (0,5-10wt%) à taux de charge constant et égal à 25% massique a été également étudié pour les trois matrices polymères. Les valeurs maximales d’IOL (indice limite d’oxygène) sont toujours obtenues pour 1-2% de SBA-15. Les modifications de surface des silices SBA-15 par greffage des différentes fonctions organiques (CTAB, amine, thiol, phénol, phosphonate, acide benzoïque et diphénylphosphate), inorganiques (aluminium, acide phosphorique et acide tungstophosphorique) ou métalliques (cuivre, nickel) ont fait l’objet de caractérisations poussées afin d’évaluer la quantité et la stabilité thermique des espèces greffées ainsi que la nature des liaisons de surface. D’autres types de nanooxydes synthétiques (aluminophosphates, phosphate de zirconium et nanotubes de type titanates) ou commerciaux (CeO2, ZrO2, CeZr et CePr) ont également été étudiés. La plupart de ces échantillons a montré un effet légèrement positif sur la stabilité thermique et le comportement au feu des polymères. De point de vue mécanistique, les analyses réalisées en Py-GC-MS montrent que les oxydes greffés par des acides catalysent la transformation des alcènes et des diènes issus de la décomposition du PE en aromatiques. En présence de SBA-15, l’analyse des résidus carbonés (par DRX, FTIR) montrent la formation de nouvelles phases cristallines phosphosiliciques qui renforcent la couche protectrice. Les phases condensées et gazeuses de quelques formulations performantes en IOL ont été analysée par cône calorimètre et microcalorimètre (PCFC). La substitution d'une fraction d'APP/PER par de la silice SBA-15 a un effet plus marqué sur la stabilité thermique et le comportement au feu de la matrice PA66 (IOL= 48,5 (+10 par rapport au PA66/APP/PER), comparé aux matrices PE (IOL=25 (+0,5 par rapport au PE/APP/PER) et PS (IOL= 24,1 (+0,8 par rapport au PS/APP/PER). De plus, la fonctionnalisation [...] / In this study, we have tried to develop new formulations to improve the thermal stability and fire behavior of three polymer matrices widely used: the polyethylene (PE), the polystyrene (PS) and the polyamide 66 (PA 66). The intumescent system used consists to combine a classical flame retardants (ammonium polyphosphate (APP) and pentaeryhthritol (PER)) with a small amount of nanooxides whose properties can be adjusted in order to improve the compatibility of the melting mixture, or to change the degradation mechanism by a chemical (catalytic effect) or physical (insulating layer, viscosity, etc …) process. The total amount of additives has been set at 25wt%. An important part of this study was consecrated to the synthesis of oxides with different morphologies, porosities, structures and functionalities. In this regard, the mesoporous silica has an advantage of having a high surface area (700-1400 m²/g) and a pore size compatible with the polymer chains. By adapting the synthesis conditions, we have aimed to correlate between some parameters related to the prepared silicas (such as (1) the specific surface area (2) particle size (3) pore size (4) morphology and (5) the type of structure (usually SBA-15)) on the thermal stability and fire behavior of different polymer matrices. A comprehensive study has been conducted globally, regardless of the matrix, that the improvements provided by the mesostructured silicas are modest compared to those elicited by classical FR. However, the fire behavior has been improved (particularly LOI) by combining APP/PER system with 1-2wt% of SBA-15. The surface modification of SBA-15 by grafting a different organic functions (CTAB, amine, thiol, phenol, phosphonate, benzoic acid and diphenylphosphate), inorganic species (aluminum, phosphoric acid and tungstophosphoric acid) or metals (copper, nickel) have been the subject of an advanced characterizations in order to assess the amount and the thermal stability of the grafted species, well as the nature of the surface bonds. Other types of synthetic nanooxides (aluminophosphates, zirconium phosphate and titanate nanotubes) or commercial (CeO2, ZrO2, CeZr and CePr) have been also studied. Most of these particles in combination with APP/PER system have shown a slightly positive effect on the thermal stability and fire behavior of polymers. In mechanistic terms, the nanooxides have mainly an effect on enhancing the barrier effect. The analyses carried out by Py/GC/MS showed that the grafted oxides by acidic species catalyze the conversion of alkenes and dienes (resulting from the decomposition of PE) to aromatics. In the presence of SBA-15, the analysis of char (by XRD and FTIR) shows the formation of new crystalline phases which enhance the protective layer.
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Cooks, cooking, and food on the early modern stageTempleman, Sally Jane January 2013 (has links)
This project aims to take the investigation of food in early modern drama, in itself a relatively new field, in a new direction. It does this by shifting the critical focus from food-based metaphors to food-based properties and food-producing cook characters. This shift reveals exciting, unexpected, and hitherto unnoticed contexts. In The Taming of the Shrew and Titus Andronicus, which were written during William Shakespeare’s inn-yard playhouse period, the playwright exploits these exceptionally aromatic venues in order to trigger site-specific responses to food-based scenes in these plays. Ben Jonson’s Bartholomew Fair brings fair-appropriate gingerbread properties onstage. When we look beneath the surface of this food effect to its bread and wine ingredients, however, it reveals a subtext that satirizes the theory of transubstantiation. Jonson expands on this theme by using Ursula’s cooking fire (a property staged in Jonson’s representation of Smithfield’s Bartholomew Fair) to engage with the prison narrative of Anne Askew, who was burned to death in front of Bartholomew Priory on the historic Smithfield for denying the doctrine of transubstantiation. This thesis also investigates water, which, for early moderns, was a complex and quasi-mystical liquid: it was a primary element, it washed sin from the world during the Great Flood, it was a marker of status, it was a medicine, and it was a cookery ingredient. Christopher Marlowe not only uses dirty water to humiliate his doomed monarch in Edward II, but he also uses it to apportion blame to the king for his own downfall. In Timon of Athens, Shakespeare draws on the theory of the elements to cast Timon as a man of water, who, Jesus-like, breaks up and divides (or splashes around) his body at his “last” supper. Fully-fledged cook characters were a relative rarity on the early modern stage. This project looks at two exceptions: Furnace in Philip Massinger’s A New Way to Pay Old Debts and the unnamed master cook in John Fletcher’s The Tragedy of Rollo, Duke of Normandy. Both playwrights use their respective gastronomic geniuses to demonstrate the danger that lower-order expertise poses to the upper classes when society is in flux. Finally, this project demonstrates that a link existed between ornate domestic food effects and alchemy. It shows how Philip Massinger’s The Great Duke of Florence and Thomas Middleton’s Women, Beware Women use food properties associated with alchemy to satirize notions of perfection in their play-worlds.
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