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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Materialval och design av klimatsmart rullgardin

Nehmé, Yasmine, Karlsson, Cecilia January 2017 (has links)
Syftet med examensarbetet har varit att hitta lämpliga textila material för en klimatsmart rullgardin med flera olika skikt skapad av företaget Climate Curtains, samt att ta fram en väl genomtänkt design som är anpassad för miljön den är tänkt att hänga i, nämligen skolor och kontor. Den klimatsmarta rullgardinen ska ha ett absorberande mattsvart material närmast glasfönstret för att fånga upp UV-strålning och därmed bli varmt. Värmen ska sedan föras in i rummet med hjälp av fläktar som sitter monterade inuti gardinstången. En solcellsfilm ska även fästas på skiktet närmast fönstret och har därför tagits med i beräkningarna, dock är solcellsfilmen fortfarande under utveckling. Tanken med solcellsfilmen är först och främst att den ska förse fläktarna med energi men även webbelysning eller laddning av mobil och dator vid överflöd av energi ska vara möjligt. Rullgardinen ska även ha ett vitt reflekterande material in mot rummet för att möjligheten att vända gardinen ska finnas. Under sommartid kan den vända gardinen istället reflektera bort UV-ljus. Mellan dessa två skikt ska ett antal mellanskikt hänga för att erhålla bättre isoleringsegenskaper samtidigt som buller och oljud minskas. Det har även varit relevant att undersöka om flamskyddsmedel bör användas eftersom att gardinen ska hänga i offentliga miljöer. Examensarbetet har bestått av litteraturstudier och praktiska experiment. Experimenten som utfördes var nöthärdighets-, flexibilitets-, reflektionstest samt säkerställning av färg. Materialen som har undersökts har alla varit gjorda av 100% polyester och två alternativa material valdes för vardera skikt. Polyester valdes till alla skikt dels för att det är billigt och dels för att polyester visade sig ha mycket goda egenskaper för de krav som ställdes. Ytterskiktet som är närmast glasfönstret samt innerskiktet in mot rummet valdes till vävar med olika bindningar. Till ytterskiktet jämfördes en tvåskaftsväv med en kypertväv där tvåskaftsväven uppvisade bäst resultat i alla testerna. Kypertväven färgade av sig och nöttes ner i nöthärdighetstestet vilket inte tvåskaftsväven gjorde. Flexibilitets- och reflektionstestet visade goda resultat för båda vävarna. I reflektionstestet pikade tvåskaftsvävens reflektionskurva en aning i det röda spektrat, vilket innebar att den hade en viss röd nyans i sig. Säkerställning av färg gick inte att utföra för de svarta vävarna då svart färg finns i oändligt många olika nyanser. Till det vita innerskiktet jämfördes en tvåskaftsväv med en satinväv. Båda vävarna hade relativt lika resultat i nöthärdighets- samt flexibilitetstestet men satinväven fick bättre resultat i reflektionstestet vilket var avgörande. Vid säkerställning av färg testades den vita färgen i ett ljusskåp i olika ljus för att kontrollera dess vithet. Det visade sig att båda vävarna innehöll optiskt vitmedel vilket även framkom i reflektionstestet då de reflekterade över 100 %. Till mellanskikten jämfördes två olika nonwovenmaterial som består av ihåliga polyesterfibrer. Ihåliga fibrer ha bra ljudabsorption vilket kan vara bra i miljöer såsom skolor och kontor där det kan vara mycket buller och höga ljudnivåer. Det ena materialet vägde 100g/m2 och det andra 250g/m2. Ett nöthärdighets- och flexibilitetstest utfördes på dessa nonwovenmaterial. De båda fick godkänt resultat i flexibilitetstestet men nonwoven 100 höll inte måttet i nöthärdighetstestet varav nonwoven 250 är mest lämpat för rullgardinen. Litteraturstudiens resultat tyder på att det inte finns några krav på flamskyddsmedel i gardiner i offentlig miljö utan endast rekommendationer. Det är alltså upp till företag att bestämma om de vill flamskydda gardinerna. De finns en mängd olika flamskyddsmedelsvarianter men de har alla en sak gemensamt och det är att de är fettlösliga och långlivade, vilket gör att de är svåra att bryta ned. Gardinen designades i en stilren och klassisk design. En kornisch utformades dels för att dölja gardinstången och dels för att erhålla ett snyggare helhetsintryck. Gardinen kommer att ha en fåll längst ned på det yttre och det inre skiktet. Inuti fållen kommer en plastskena läggas för att få tyngd i materialet och därmed ett bättre fall. Fållen ger även gardinen en lyxigare känsla. Resterande kanter på alla materialen för alla skikt valdes att lasras. Med laserskärning erhålls fina kanter som inte fransar sig alls och laserskärning garanterar även att det inte blir någon nötning på produkten under skärningen vilket är fördelaktigt på en rullgardin då den rullas upp och ner mycket. Skisser ritades upp i Kaledo Style för att få en tydligare bild av hur rullgardinen kan komma att se ut. Eventuella tillval, mönster på det vita skiktet samt solceller i olika storlekar, kan även göras på gardinen beroende på kundens önskemål. För att kunna applicera mönstret på det textila materialet undersöktes tre alternativa tryckmönstermetoder; rollerprinting, roterande screentryck samt digital inktryck. De två sistnämnda lämpar sig bäst för ändamålet. / The aim of the thesis was to find the optimal textile materials for a climate-smart blind with multiple layers created by the company Climate Curtains. The aim was also to develop a well thought out design that is adapted to the environments it is supposed to hang in, which are schools and offices. The climate-smart blind should have an absorbing black matte material closest to the glass window to capture UV radiation and thereby become warm. The heat will then be brought into the room with the help of fans that are mounted inside the curtain rod. A solar cell film should also be attached to the layer closest to the window and have therefore been included in the calculations, however, the solar film is still under development. The idea of a solar cell film is first and foremost that it will provide fans with energy but also charging of mobile and computer at the abundance of energy. The blind must also have a white reflective material into the room for the possibility of turning the curtain in the summer. This leads to a reflection of the UV light instead of absorption. Between these two layers, a number of intermediate layers will hang to provide isolation of air and noise reduction. The amount of flame retardants have also been relevant to examine because the curtain will hang in public places. There are no requirements in public places when it comes to flame retardants, but there are recommendations published. A solar cell film should also be attached to the layer closest to the window and have therefore been included in the calculations. However, the solar film is still under development. The work has consisted of literature studies, laboratory work and compilation of discussion and results. The laboratory work included abrasion resistance-, flexibility-, reflection test and a test to secure the colors. The materials studied have all been made of 100% polyester and two alternative materials were chosen for each layer. Polyester was chosen to all layers partly because it is cheap and secondly because polyester was found to have very good qualities for the demands made. The outer layer closest to the window and the inner layer into the room consists of fabrics made of weaves with different constructions. For the outer layer a plain weave and a twill weave were chosen to be compared against each other. The plain weave got the best results in all of the tests. For the inner layer a satin weave and a plain weave were compared, and the satin weave got the best results in all the tests. Furthermore, the layers in between the weave textiles are made of hollow polyester fibers as a nonwoven material. Hollow fibers have good sound absorption, which can be useful in environments such as schools and offices where there may be much noise and high sound levels. One material weighing 100 g/m2 and the other 250 g/m2. An abrasion resistance- and flexibility test was conducted on these nonwoven materials. They both got approved results in the flexibility test. However, nonwoven 100 was not good enough in the abrasion resistance test and therefor nonwoven 250 is the most suitable middle layer for the blind. The curtain was designed in a stylish and classic design. A cornice designed partly to hide the curtain rod and partly to obtain a more attractive overall impression. The blind will have a hem at the bottom of the outer and the inner layer. Inside the hem a plastic splint is added to give better stability. The hem also gives the curtain a luxurious feel. The remaining edges on all materials for all layers were chosen to be lasered. With laser cutting fine edges are obtained.4Sketches were drawn up in Kaledo Style to get a clearer picture of how the blind could look like. Any optional patterns on the white layer and the solar cells of different sizes, can also be made on the curtain, depending on customer requirements. In order to apply the pattern to the textile material three alternative methods was studied; roller printing, rotary screen printing and digital ink print. Screenprinting and digital printing was best suited for the purpose.
92

Transfer and effects of brominated flame retardants (BFRs) on three plant species and one earthworm species in anthroposoils / Transfert et effets des retardateurs de flamme bromés (RFBs) sur trois espèces végétales et une espèce de lombric dans des anthroposols

Coelho Macedo, Cláudia Filipa 30 September 2019 (has links)
Une étude approfondie a été menée dans deux zones distinctes (Estarreja au Portugal, noté EST, et Casier Peyraud 6 en France, noté PEY) pour évaluer les niveaux de contamination, ainsi que leurs comportements dans des anthroposols et les risques potentiels de ces contaminants pour des organismes vivants du sol. L’objectif principal étant d’évaluer la mobilité environnementale des retardateurs de flamme bromés (RFBs) dans un écosystème terrestre, notamment vers les vers de terre (Eisenia fetida) et les plants (luzerne (Medicago sativa), cresson (Nasturtium officinale), moutarde blanche (Sinapsis alba), dans une prospective d’évaluation du risque de transferts de ces molécules.Le facteur de bioaccumulation (BAF) ainsi que les indices SET et ERITME ont été calculés. Le BAF permet de déterminer si une substance est accumulée dans un organisme donné et s’il existe un risque d’entrée et de diffusion tout au long de la chaine alimentaire. Les indices SET et ERITME permettent de classer les sites testés en fonction du transfert efficace des COs par les anthroposols aux organismes testés, et d’avoir une idée du risque potentiel pour l’écosystème. L’indice SET donne une idée globale de l’excès de transfert pour tous les contaminants dans les matrices étudiées. L’indice ERITME permet d’évaluer le risque environnemental global inhérent associé à l’excès de transfert des contaminants considérés. Compte tenu des valeurs ERITME, les matrices étudiées peuvent être classées dans un ordre de toxicité qui est aussi conforme pour l’ensemble des organismes testés (E. fetida, luzerne, cresson et moutarde). / A comprehensive study was conducted in two distinct areas (Estarreja in Portugal, noted EST, and Casier Peyraud 6 in France, noted PEY) to assess the contamination levels as well as their behavior in soils and the potential risks posed by these contaminants to soil organisms. The principal aim was to evaluate the environmental mobility of brominated flame retardants (BFRs) in a terrestrial ecosystem, namely to earthworms (Eisenia fetida) and plants (alfalfa (Medicago sativa), watercress (Nasturtium officinale) and white mustard (Sinapis alba)), concerning the BFRs transfer risk evaluation. The Bioaccumulation factor (BAF) as well as the SET and ERITME indexes were calculated. The BAF allow to determine if a substance is accumulated in a certain organism and if there exists the risk of entry and diffusion along the food chain. SET and ERITME indexes allow to rank the tested sites according to the effective OCs transfer from anthroposoils to the tested organisms and have an idea of the potential risk to the ec system. The SET index gives a global idea of the excess of transfer for all the contaminants in the studied matrices. The ERITME index allows to evaluate the possible inherent global environmental risk associated with the excess of transfer on the considered contaminants. Considering the ERITME values, the studied matrices can be classified in an apparent increasing order of toxicity that it is also in accordance with the levels of OCs found in the all the tested organisms (E. fetida, alfalfa, cress and mustard).
93

Retardéry hoření a jejich průnik do terestrického ekosystému / Flame retardants and their penetration into the terrestrial ecosystem

Chytil, Václav January 2014 (has links)
This diploma thesis was focused on the analysis of four compounds from brominated flame retardants group, namely pentabromoethylbenzene, hexabromocyclododecane, hexabromobenzene and tetrabromobisphenol A. Matrices were represented by four soil samples and four seat of fire samples. In addition, bisphenol A was also determined. First of all, process of extraction of analytes from matrices was optimized. Three different extraction techniques were tested (pressurized solvent extraction, microwave-assisted extraction and ultrasound-assisted extraction). Next step was to verify stability of target compounds in strongly acidic conditions and to optimize clean-up of extract by column chromatography. Gas chromatography with electron capture detection (GC-ECD) was chosen as an appropriate analytical method for the determination of brominated flame retardants. Bisphenol A was determined by gas chromatography with mass spectrometric detection (GC-MS). The derivatization of phenolic analytes before their final analytical determination was also essential.
94

Aprotické elektrolyty s retardery hoření / Aprotic electrolytes with fire retardant

Hlava, Kamil January 2015 (has links)
This thesis deals with liquid aprotic electrolytes based on sulfolane with added flame retardant. The theoretical part of the thesis explains concepts - mainly aprotic electrolytes, flame retardants, and their practical use. It also discusses lithium - ion accumulators and materials used in them while focusing on the electrolyte function. The practical part of the thesis aims to measure the properties of aprotic electrolytes: their conductivity, potential window and flashpoint. It also contains a review of the measurement results.
95

Biosurveillance des retardateurs de flamme organophosphorés chez les travailleurs du recyclage électronique au Québec

Traore, Inna Tata 05 1900 (has links)
No description available.
96

Exposition des travailleurs du recyclage électronique à des ignifuges et association à des effets endocriniens.

Gravel, Sabrina 06 1900 (has links)
Les ignifuges sont ajoutés à divers produits afin de les rendre conformes aux normes d’inflammabilité. Les plus communs sont les polybromodiphényléthers (PBDE) et les esters d’organophosphorés (OPE), qui sont détectés en forte proportion dans la population générale. Quelques industries, comme celle du recyclage électronique, peuvent exposer les travailleurs à des niveaux élevés de ces ignifuges, dont certains sont soupçonnés d’être des perturbateurs endocriniens. L’objectif de cette thèse était d’évaluer l’exposition à des ignifuges chez les travailleurs et d’étudier les effets endocriniens associés. Trois types de données ont été utilisés. D’abord, deux bases de données populationnelles ont permis de déterminer les valeurs biologiques de base des PBDE chez les travailleurs des populations générales canadienne et états-unienne, et d’identifier les secteurs industriels les plus exposés. Ensuite, une revue systématique de littérature a recensé les niveaux d’exposition professionnelle aux ignifuges dans diverses industries en portant un regard critique sur les méthodes de prélèvement. Finalement, des prélèvements d’air en poste personnel, d’urine et de sang ont été réalisés auprès de 100 travailleurs dans six entreprises de recyclage électronique et une de recyclage commercial. Des modèles Tobit et des régressions de Cox inversées ont identifié les tâches les plus exposantes. L’association entre les mesures biologiques d’exposition et les niveaux d’hormones thyroïdiennes et sexuelles a été explorée avec des modèles Tobit et des régressions sur composantes principales. L’analyse des données populationnelles a révélé que les travailleurs canadiens, tous secteurs confondus, avaient des concentrations sériques de PBDE 10 à 20% plus élevées que celles des non-travailleurs. La revue systématique a identifié les milieux du recyclage électronique, de la fabrication de câbles, du transport aérien et des casernes d’incendie comme étant parmi les plus exposants aux ignifuges, particulièrement au BDE209. Cependant, les méthodes de prélèvement utilisées dans ces études étaient généralement peu appropriées pour les ignifuges. L’analyse des données de l’étude terrain a mis en évidence des concentrations d’ignifuges dans l’air plus élevées dans le recyclage électronique que dans le recyclage commercial, avec une concentration en BDE209 plus élevée que toutes les valeurs publiées à ce jour (moyenne géométrique [MG] : 5100 ng/m³). Les tâches de démantèlement et de compactage étaient respectivement associées à des expositions en moyenne 2,2 et 1,4 fois plus élevées que celle de supervision. Finalement, les concentrations sanguines de BDE209 (MG : 18 ng/g lipides) chez les travailleurs du recyclage électronique étaient plus élevées que dans le recyclage commercial (MG : 1,7 ng/g lipides), mais moins élevées que celles rapportées dans la fabrication de câbles (moyenne : 54 ng/g lipides). On a estimé chez l’homme des diminutions de 18% de la testostérone libre et totale pour un doublement de la concentration de tb-TPhP (métabolite OPE), et une augmentation de 16% de l’estradiol pour un doublement de la concentration de o-iPr-DPhP (métabolite OPE). Cette thèse montre que l’exposition aux ignifuges est très répandue, particulièrement chez les travailleurs de quelques industries. Les concentrations plus élevées de certains ignifuges dans le recyclage électronique par rapport aux autres industries, et l’association entre l’exposition aux OPE et les niveaux d’hormones sexuelles chez l’homme ont été identifiées pour la première fois. Bien que devant être reproduits, ces résultats justifient des efforts préventifs de maîtrise de l’exposition aux ignifuges dans cette industrie. / Flame retardants are added to various products to comply to flammability standards. The most common are polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs), which are detected in high proportion in the general population. A few industries, such as electronic recycling, can expose workers to high levels of flame retardants, some of which are suspected of being endocrine disruptors. The objective of this thesis was to evaluate the exposure to flame retardants in workers and to study the associated endocrine effects. Three types of data were used. First, two population databases were used to determine baseline PBDE levels for workers in the general population in Canada and the United States, and to identify the major industrial sectors that are exposed the most. Then, a systematic literature review identified levels of occupational exposure to flame retardants in various industries while critically examining sampling methods. Finally, personal air, urine and blood samples were collected from 100 workers in six electronic recycling and one commercial recycling companies. Tobit models and reverse Cox regressions identified the most exposing tasks. The association between biological concentrations of flame retardants and thyroid and sex hormone levels was explored with Tobit models and principal component regressions. The analysis of the population data revealed that Canadian workers, taking all sectors into consideration, had serum PBDE levels 10 to 20% higher than those of non-workers. The systematic review identified electronic recycling, cable manufacturing, air transport and fire stations as some of the workplaces where flame retardants were found in the highest concentrations, particularly BDE209. However, the sampling methods used in these studies were generally not optimal for flame retardants. Analysis of the field study data revealed higher air concentrations of flame retardants in electronic recycling than in commercial recycling, with a higher BDE209 concentration than all values published to date (geometric mean [MG]: 5100 ng/m³). Dismantling and bailing tasks were associated with exposures averaging 2.2 and 1.4 times higher than supervisory tasks, respectively. Finally, blood concentrations of BDE209 (MG: 18 ng/g lipid) in electronic recycling workers were higher than in commercial recycling (MG: 1.7 ng/g lipid), but lower than those reported in cable manufacturing (average: 54 ng/g lipid). Decreases of 18% in free and total testosterone were estimated in humans for a doubling of the concentration of tb-TPhP (OPE metabolite), and a 16% increase in estradiol for a doubling of the concentration of o-iPr-DPhP (OPE metabolite). This thesis shows that exposure to flame retardants is widespread, particularly among workers in a few industries. The higher concentrations of some flame retardants in electronic recycling compared with other industries, and the association between exposure to OPEs and sex hormone levels in humans were identified for the first time. Although these results must be reproduced, they justify preventive efforts to control exposure to flame retardants in this industry.
97

Vývoj izolačních materiálů na bázi druhotných textilních vláken nižší kvality / Development of insulation materials based on secondary textile fibers of lower quality

Mlynářová, Jana January 2021 (has links)
This diploma thesis is focused on a suitable midification of acoustic and thermal insulation materials from recycled textile fibres of lower quality due to improvement of their reaction to fire. The aim is to find an effective flame retardant and to verify suitable method of flame retardant application onto this type of insulation material.
98

Nové gelové elektrolyty / New gel electrolytes

Sumka, Martin January 2016 (has links)
This master´s thesis deals with the properties of gel polymer electrolytes, brief characteristics of other types of electrolytes and materials that are used for preparing polymer electrolytes. The thesis explains the use of the gel electrolytes in practice, the current conduction in the electrolytes and the properties of ionic liquids, and flame retardants. This thesis also focuses on methods of measurement of mechanical properties of gel polymer electrolytes. The practical part is focused on preparation of methacrylate gel electrolytes and their modifications with the use of flame retardant - triethyl phosphate (TEP) and ionic liquid - 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Emim TFSI). In this part there are evaluations of their potential funcionality (potential window) and specific conductance conductivity using the method LSV (linear sweep voltammetry) and impedance spectroscopy. The practical part also includes a thermal analysis of selected samples by TGA, DTA and EGA methods.
99

Impact of Halogenated Aliphatic and Aromatic Additives on Soot and Polycyclic Aromatic Hydrocarbons -- An Ethylene-air Laminar Co-flow Diffusion Flame Study

Kondaveeti, Rajiv 21 August 2012 (has links)
No description available.

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