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Influência do ciclo reprodutivo do caranguejo de mangue Ucides Cordatus (Linnaeus, 1763) na dinâmicas de elementos- traçosAlmeida, Eduardo Vianna de 25 April 2016 (has links)
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Tese Eduardo Almeida.pdf: 4456269 bytes, checksum: b74d643c3c7aec835392881bd8989cce (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ / O caranguejo uçá (Ucides cordatus) é típico de manguezais, tendo importante papel na ciclagem de nutrientes. Apresenta desenvolvimento indireto e a fêmea transporta os ovos por cerca de um mês, havendo em seguida, fase larval planctônica. Poucos estudos tratam da transferência de elementos-traço das fêmeas para os embriões ou do meio para estes. Trabalhos sobre a contaminação das fêmeas são escassos e até o momento, nenhum abordou a contaminação em embriões e larvas de U. cordatus. O objetivo do presente estudo foi analisar a concentração de elementos-traço em fêmeas, ovos em diferentes estágios e larvas recém-eclodidas de duas populações do sudeste do Brasil (baía de Guanabara e Rio Paraíba do Sul). Também objetivou avaliar se o ciclo reprodutivo da espécie pode resultar em exportação de elementos-traço dos manguezais para a costa adjacente. Por fim, foram analisados o δ13C, δ15N e a razão N/C nas fêmeas. Através de coleta manual, fêmeas ovígeras foram obtidas nos verões de 2012, 2013 e 2014. Parte delas foi levada para aquários de desova, onde foram obtidas as larvas recém-eclodidas. Em laboratório, tecidos, ovos e larvas foram congelados e depois liofilizados e digeridos em ácido nítrico suprapuro, com auxílio de micro-ondas. Concentrações de elementos traço foram obtidas em ICP-MS. Foram analisadas fêmeas com largura da carapaça entre 5,5 e 7,9 cm. A fecundidade foi semelhante nas duas áreas de estudo (média > 110.000 ovos.fêmea-1). A análise de δ13C demonstrou diferenças significativas entre as populações. Apesar disso, os dados apontaram folhas de mangue como principal item alimentar. Os valores de δ15N foram acima do esperado para o nível trófico da espécie. Nas fêmeas, as maiores concentrações de Cu, Cr, Cd e As foram observadas nas brânquias, principalmente anteriores. Níquel foi mais concentrado no hepatopâncreas, enquanto Zn foi mais concentrado em músculos e hepatopâncreas. Fêmeas do Rio Paraíba do Sul apresentaram maiores níveis de contaminação, em especial de Mn, Cr, Cu, Cd e Ba. Tal tendência foi coerente com os níveis observados em sedimentos superficiais e com dados de biodisponibilidade citados na literatura. Em comparação com estágios iniciais dos ovos e larvas recém-eclodidas, as concentrações de V, Cr, Ni e Pb foram maiores em ovos no estágio final de desenvolvimento, indicando que a casca do ovo previne o contato do embrião com certos elementos-traço. As concentrações de Cd e Ni foram maiores no hepatopâncreas das fêmeas do que em ovos e larvas. Por outro lado, os elementos V, Zn, As e Pb foram mais concentrados nas larvas. Os resultados do presente estudo corroboraram as vias de contaminação de embriões postuladas em trabalhos com outras espécies: 1. Transferência de elementos-traço das fêmeas para os ovos, durante sua formação; e 2. Absorção de elementos-traço do meio circundante durante o desenvolvimento embrionário. Considerando as concentrações em larvas e a quantidade de larvas liberadas nas desovas, pode-se afirmar que o ciclo reprodutivo da espécie resulta na transferência de elementos-traço do bentos para o ambiente pelágico. Durante as desovas (liberação larval) de U. cordatus na baía de Guanabara e no Rio Paraíba do Sul, os elementos Zn, Cu, Mn, As e Ba teriam a maior introdução na coluna d’água, sendo provavelmente transportados para a costa adjacente. Considerando as diversas espécies de caranguejos de manguezais que têm hábitos e ciclo de vida muito semelhantes aos do caranguejo uçá, o período reprodutivo destes animais pode resultar em relevante exportação de elementos-traço / The uçá crab (Ucides cordatus) is typical of mangroves and has important role in nutrient cycling. The specie presents indirect development and female carries the eggs for about a month. After, planktonic larvae are released. There are few studies about the transfer of trace elements from female to embryos or from environment for these. Studies about contamination of females are scarce and none was made with embryos and larvae of U. cordatus. The aim of this study were to analyze the concentration of trace elements in females, eggs in different stages and newly hatched larvae of two populations of southeastern Brazil (Guanabara Bay and Paraíba do Sul River). Also aimed evaluate if the reproductive cycle of the species can result in export of trace elements of mangroves for adjacent coast. As complementary data the δ13C, δ15N and the N/C in females were analyzed. Ovigerous females were obtained in the summers of 2012, 2013 and 2014. Tissues, eggs and larvae were lyophilized and digested in superpure nitric acid using microwave. Concentrations of trace elements were analyzed in ICP-MS. Females showed carapace width between 5.5 and 7.9 cm. Fecundity was similar in both study areas (mean > 110,000 eggs female -1). The δ13C analysis showed significant differences among populations. Nevertheless, the data showed mangrove leaves as main food. The δ15N values were higher than expected for the trophic level of the species. The highest concentrations of Cu, Cr, Cd and As were observed in gills, especially anterior gills. Nickel was more concentrated in the hepatopancreas, while Zn was more concentrated in muscle and hepatopancreas. Concentrations of V, Cr, Ni and Pb in eggs of the final developmental stage were higher than observed in early stages and newly hatched larvae. This indicates that eggshell is a barrier for certain trace elements. Cadmium and Ni were more concentrated in hepatopancreas of females than in eggs and larvae. On the other hand, the elements V, Zn, As and Pb were more concentrated in larvae. Females of the Paraíba do Sul River had higher levels of contamination, especially of Mn, Cr, Cu, Cd and Ba. This trend was consistent with the levels observed in surface sediments and bioavailability data cited in the literature. Our data corroborate the pathways of embryos contamination, postulated in anterior studies with other species: 1. Transfer of trace elements between females and eggs, during your formation; 2. Absorption of trace elements from the environment during embryonic development. According to the concentrations of trace elements in larvae and the amount of larvae released in the spawns, it is clear that the reproductive cycle of the species results in transfer of benthic trace elements for the pelagic environment. During spawns of U. cordatus in Guanabara Bay and Paraíba do Sul River, Zn, Cu, Mn, As and Ba were the elements more introduced in water column, being probably transported to the adjacent coast. Considering the various species of mangrove crabs that have habits and life cycle similar to uçá crab, the reproductive period of these animals can result in significant exportation of trace elements
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To Build Maps of Writing and Critical Consciousness: Transfer in Writing Studies & Critical PedagogiesSmith, Spencer J. 05 July 2017 (has links)
No description available.
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North of Ourselves: Identity and Place in Jim Wayne Miller’s PoetryMcCrotty, Micah 01 May 2019 (has links)
Jim Wayne Miller’s poetry examines how human history and topography join to create place. His work often incorporates images of land and ecology; it deliberately questions the delineation between place and self. This thesis explores how Miller presents images of water to describe the relationship between inhabitants and their location, both with the positive image of the spring and the negative image of the flood. Additionally, this thesis examines how the Brier, Miller’s most prominent persona character, grieves his separation from home and ultimately finds healing and reunification of the self through his return to the hills. In his poetry, Miller argues that an essential piece of people’s identity is linked with the land, and, through recognition of the importance of topography on the development of the self, individuals can foster a deeper sense of community through appreciation of their place.
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Kollaborativ modekonsumtion : Vilken inverkan har fast fashion på konsumentens inställning till kläduthyrning? / Collaborative fashion consumption : What influence does fast fashion have on consumer attitudes towards fashion rental services?Jernqvist, Agnes, Lundgren, Linn January 2023 (has links)
Idag konsumeras en betydligt större mängd kläder än för ett decennium sedan, samtidigt som de inte används i samma utsträckning. Detta beteendemönster i samband med fast fashion-industrins upptakt resulterar i överkonsumtion, vilket fått omfattande konsekvenser för miljön. För att motarbeta fast fashion-konsumtion har alternativa konsumtionsmetoder utvecklats, såsom kollaborativ konsumtion i form av uthyrning. Under branschens utveckling har ett flertal modeuthyrningstjänster för vardagsbruk försökt etablera sig på svenska marknaden med varierande resultat. Under en ettårsperiod från 2022 till 2023 ansökte fyra av Sveriges största aktörer inom modeuthyrning på onlinemarknaden om likvidering, vilket har lämnat den svenska marknaden utan uthyrningsalternativ för vardagskläder. Ett ämne som kan beaktas är om fast fashion-konsumtionens tillgänglighet och slagkraft bidragit till uthyrningstjänsternas nuvarande position. Studien syftar till att undersöka fast fashion-konsumtionens påverkan av kläduthyrning för vardagsbruk. Genom att studera zillennials attityder till fast fashion kontra kläduthyrning är avsikten att skapa en ökad förståelse kring om fast fashion bidrar till minskad kollaborativ modekonsumtion. Detta undersöks med hjälp av en litteraturstudie samt utvalda respondenter genom att kvalitativa data samlas i form av fokusgruppsintervjuer. Studien har funnit att fast fashion delvis skapar utmaningar för kläduthyrning men att det även finns andra faktorer oberoende av fast fashions existens som skapar ogynnsamma förhållanden. Ett avsaknat behov till följd av fast fashions tillgänglighet, okunskap om innebörden av uthyrningstjänster och orosmoment kring konceptet ligger till grund för konsumenternas inställning till kollaborativ modekonsumtion. / Today, a considerable volume of clothing is consumed compared to a decade ago. Simultaneously, they are not used to the same extent. This behavioral pattern in connection with the fast fashion industry’s growth results in over consumption, which has extensive consequences for the environment. To counteract fast fashion consumption, alternative consumption methods have been developed, like collaborative fashion consumption as fashion rental. During the development of the industry, there have been multiple fashion rental services for everyday apparel. These have tried to establish themselves on the Swedish market with varied results. During a one-year-period from 2022 to 2023, four of Sweden’s biggest actors within fashion rental online applied for liquidation. This has left the Swedish market without rental options for everyday apparel. Thus, the subject to consider is if the availability and pulling power of fast fashion consumption has contributed to the fashion rental services current position. The study aims to investigate the impact fast fashion consumption has on fashion rental services for everyday apparel. By studying zillennials’ attitudes towards fast fashion versus fashion rental services, the intention is to create an increased understanding of whether fast fashion contributes to decreased collaborative fashion consumption. This will be investigated using a literature study, as well as collecting qualitative data through focus group interviews with selected respondents. The study has found that fast fashion partly creates challenges for clothing rental, but that there are other factors independent of fast fashion's existence that creates a disadvantage. The lack of need as a result of fast fashion's accessibility, lack of knowledge of the meaning of rental services and concerns about the concept lays the foundation for consumer attitudes towards collaborative fashion consumption.
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“Skräckpropaganda kommer inte att hjälpa någon” : En studie som undersöker vad dags- och veckopress samt Sexperternas hemsida skriver om kemsexGarcés, Nathalie, Efraimsson, Jorun January 2023 (has links)
Syftet med denna studie är att utifrån ett socialkonstruktionistiskt perspektiv undersöka på vilka sätt fenomenet kemsex skildras i dags- och veckopress och hur information från stödmottagning för sexuell hälsa är utformad. Kemsex är en typ av sexualiserat drogbruk och förekommer främst bland män som har sex med män. Det är ett komplext fenomen och en del av problematiken är att fenomenet berör olika discipliner. Att det berör olika discipliner resulterar i att målgruppens potentiella problematik kan beröra såväl missbruk som risktagande inom sex. Inom det sociala arbetet har fenomenet nyligen uppmärksammats av både professionella och i tidningsartiklar, men det finns en avsaknad av kunskap. Denna avsaknad av kunskap leder också till förutfattade meningar om både målgruppen och fenomenet. Dessutom stigmatiseras målgruppen då de både är en minoritetsgrupp och ägnar sig åt icke-normativt sex som innefattar droger. Studiens teoretiska ramverk innefattar därför teorier om normer, avvikelse och interaktion i förhållande till sex, samt teorier inom skadereducerande arbete. Tillvägagångssättet är en dokumentstudie av dags- och veckopress, samt hemsidan av Sexperternas samtalsmottagning. Analysmetoden är en latent tematisk analys, som inneburit en djupgående bearbetning av materialet som utmynnat i tre huvudteman. Resultatet visar på att det finns en övervägande negativ syn på kemsex i tidningsartiklar, men att Sexperternas hemsida och professionella strävar efter ett icke-dömande förhållningssätt. Det empiriska materialet beskriver endast kemsex i relation till män som har sex med män.
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… Som att slicka på en regnkappa. En kvantitativ studie av kvinnor som har sex med kvinnor och sexuellt överförbara sjukdomar/säkrare sexLarsdotter, Suzann January 2009 (has links)
The background to this thesis is that we know very little about lesbian and bisexual women's sexual health in Sweden, particularly in relation to sexually transmitted infections (STI) and their transmissions. An internet-based questionnaire with self-selected participants targeted to the group WSW (Women who have Sex with Women) has been implemented. An international survey on the subject shows that the WSW has sexually transmitted infections. This is also in line with the results in this study. The most common sexually transmitted infection in the survey is chlamydia which 12.3 percent have had. This is a remarkably high figure in comparison with international studies. There are a number of barriers to WSW developing safer sex strategies. Many described a heteronormative response and very low level of knowledge in the health-care.Also WSW themselves have no or little knowledge on the subject. Prevention messages to the group, WSW is often about to use dental dams and very few in practice and in the case where it is used, it has only a very limited function. The majority of women in the study have had sexual contact with both men and women, this applies to both lesbian and bisexually women. In a theoretical analysis, it is possible to discern a conflict between the postmodern and the modern understanding of love and sexuality. This conflict does not exist only on an interpersonal / cultural level but also on a intrapsychic level of humans.
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L’association entre la perception du risque à l’égard du VIH, les comportements sexuels et l’utilisation de la PrEP d’hommes gbHARSAHCharron, Mélanie 05 1900 (has links)
La PrEP pourrait avoir un impact sur la perception du risque du VIH et ainsi influencer les comportements sexuels d’hommes gais, bisexuels et autres hommes ayant des relations sexuelles avec d’autres hommes (gbHARSAH). Les buts de l’étude étaient 1) de comparer les caractéristiques sociodémographiques, les habitudes de vie, les comportements sexuels et relationnels, les antécédents d’infections transmissibles sexuellement et des facteurs psychosociaux liés à la prise de risque d’hommes gbHARSAH en fonction de la perception du risque du VIH et 2) d’examiner l’association entre cette perception du risque et les relations anales sans condom (RASC) selon l'utilisation de la PrEP. Cette étude descriptive corrélative consistait en une analyse secondaire de l’étude ENGAGE réalisée auprès de 945 hommes gbHARSAH. Comparativement au groupe qui se percevait moins à risque du VIH (n = 773), celui qui se percevait plus à risque (n = 172) différait quant aux comportements sexuels. Dans l’analyse non stratifiée, le risque perçu élevé du VIH était associé aux RASC (RC = 2,87; 95 % IC = 1,84 - 4,47) et l’utilisation de la PrEP était associée aux RASC (RC = 12,75; 95 % IC = 3,43 - 47,41). Dans l’analyse stratifiée, parmi les hommes qui n’étaient pas sous PrEP, seule l’association entre le risque perçu élevé du VIH et des RASC était maintenue (RC = 2,91; 95 % IC = 1,86 - 4,57). Cette étude montre l’influence de la perception du risque sur les comportements sexuels, suggérant ainsi la pertinence d’une approche globale de la prévention du VIH. / PrEP may impact self-perceived risk for HIV infection and influence the sexual behaviors among gay, bisexual and other men who have sex with men (gbMSM). The aims of this study were 1) to compare the sociodemographic characteristics and lifestyles, sexual and relational behaviors, history of sexually transmitted and blood-borne infections, and psychosocial factors related to risk-taking behaviors of gbMSM according to self-perceived risk for HIV infection, and 2) to examine the association between self-perceived risk for HIV infection and condomless anal intercourse (CAI) according to PrEP use. This descriptive and correlational study was a secondary analysis of data collected by the ENGAGE study which involved 945 gbMSM. Compared with gbMSM with lower self-perceived risk for HIV (n = 773), those with higher self-perceived risk (n = 172) differed in terms of sexual behaviors. An unstratified analysis showed high self-perceived risk for HIV infection to be associated with CAI (aOR: 2.87, 95% CI: 1.84–4.47) and PrEP use to be associated with CAI (aOR: 12.75, 95% CI: 3.43–47.41). A stratified analysis by PrEP use showed that, among gbMSM who did not use PrEP, only the association between high self-perceived risk for HIV infection and CAI was maintained (aOR: 2.91, 95% CI: 1.86–4.57). This study reveals the influence of risk perception on sexual behaviors and highlights the importance of a global approach to prevention of HIV infection.
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Les facilitateurs et les obstacles à la situation d’inclusion scolaire d’élèves francophones issu·es de l’immigration récente en classe ordinaire du primaireMontesano, Gabrielle 12 1900 (has links)
Ayant comme première langue apprise ou d’usage le français, les élèves francophones issu·es de l’immigration récente (EFIIR) sont souvent directement inclus·es en classe ordinaire dans le niveau scolaire de leur groupe d’âge (MELS, 2014d). Elles et ils ne reçoivent généralement pas de soutien particulier puisque l’école considère leur maîtrise de la langue d’enseignement suffisante. Pourtant, ces EFIIR sont confronté·es à des obstacles potentiels de taille (Gosselin-Gagné, 2018a). Pour favoriser leur plein épanouissement, l’inclusion scolaire est alors un concept à mobiliser (Potvin, 2013). S’appuyant sur le socioconstructivisme, elle amène le personnel à reconnaître l’hétérogénéité des profils des élèves et à mettre en œuvre des pratiques équitables et adaptées à leurs besoins. Ce projet de recherche a 3 objectifs spécifiques : 1) documenter les facilitateurs et obstacles à la situation d’inclusion d’EFIIR dans leur groupe classe ordinaire du primaire; 2) dégager des pratiques inclusives et socioconstructivistes qui soutiennent leur situation d’inclusion; et 3) analyser leur situation d’inclusion en fonction de la synthèse retenue et des principes de l’inclusion scolaire. Le type de recherche adoptée est l’étude de cas multiples. La triangulation des données a été assurée par leur collecte auprès de trois types de personnes participantes, soit les EFIIR, leur parent et le personnel scolaire impliqué dans leur situation d’inclusion, et ce, avec des entretiens semi-dirigés. Les résultats se structurent autour de trois études de cas de situations d’inclusion d’EFIIR. Plusieurs facilitateurs, comme le soutien des parents et celui de la personne enseignante titulaire, ont été nommés par les personnes participantes et dégagés à la suite de l’analyse des données collectées. Les EFIIR ont également rencontré divers obstacles en lien avec leurs apprentissages en mathématiques, la diversité culturelle et linguistique du français, et la création de liens d’amitié. Ces facilitateurs et obstacles étaient davantage nommés par les personnes participantes comme étant intrinsèques aux EFIIR, ce qui a suggéré un manque d’adaptation réciproque de la part de l’école. De plus, une variété de pratiques inclusives et socioconstructivistes qui soutiennent la situation d’inclusion scolaire de ces EFIIR a été soulevée tels un protocole d’accueil réfléchi, l’enseignement explicite de l’empathie et l’accompagnement des élèves dans leur socialisation. / Students who have recently immigrated that master French as their first spoken language are often directly included in schools in ordinary classes associated to their age group (MELS, 2014d). They generally do not receive any particular support since schools consider their competencies of the language of instruction sufficient. However, these students face significant potential obstacles (Gosselin-Gagné, 2018a). To promote their full potential, inclusion is a concept to mobilize (Potvin, 2013). Based on the sociocultural theory, it encourages school staff to recognize the heterogeneity of student profiles and intervene in an equitable and adapted way to answer their needs. This research project has 3 specific objectives: 1) to document the facilitators and obstacles to the situation of inclusion of French-speaking students who have recently immigrated in ordinary classes in elementary schools; 2) to identify inclusive and sociocultural practices that support the situation of inclusion of these students; and 3) to analyze their situation of inclusion according to the retained synthesis of inclusive education and its principles. This project is a multiple case study. Triangulation of the data was ensured by collecting them from three types of participants, namely French-speaking students who have recently immigrated, their parents and school staff involved in their situation of inclusion, with semi-structured interviews. The results are structured around three case studies of the situation of inclusion of three French-speaking students who have recently immigrated. Several facilitators, such as support from parents and from the classroom teacher, were named by the participants and identified following the analysis of the data collected. These students encountered various obstacles related to their learning in mathematics, the cultural and linguistic diversity of French, and the creation of friendships. These facilitators and obstacles were often named as being intrinsic to the students, which suggested a lack of reciprocal adaptation on behalf of the schools. In addition, a variety of inclusive and sociocultural practices that supported the situation of inclusion of these French-speaking students who had recently immigrated were raised, such as a thoughtful reception protocol, the explicit teaching of empathy, and the support for students in their socialization.
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Hårdgörning av Asp / Densification of Aspen WoodJohansson, Martin January 2008 (has links)
Hårdgörning av trä syftar till att göra materialet hårdare. Detta går att åstadkomma genom komprimering, det komprimerade materialet tenderar dock att återgå mot sin ursprungsform då materialet utsätts för fukt om ingen låsning sker. Låsningen kan ske mekaniskt i en treskiktskonstruktion som motverkar träets fuktrörelser. Dessa skivor har dock visat sig vara instabila och tidigare försök har uppvisat deformationer i form av kupning. Denna undersökning syftar till att utreda förutsättningarna för att använda komprimerad asp samt att ta fram underlag för framtagning av en kommersiell produkt. Praktiska tester har genomförts för att studera hårdhet, återfjädring och densitet hos det komprimerade virket. Vidare har treskiktsskivor tagits fram för att testa om det går att få en stabil konstruktion genom att variera tjockleken på spärrskiktet. Även skillnader i acklimatiseringstid och fuktkvotens inverkan för virkets återfjädring har studerats. Resultaten visar på att aspens hårdhet efter komprimering blir i samma nivå som bok och ask, en låg fuktkkvot vid komprimering av materialet ger en låg återfjädring, komprimerat material har en längre acklimatiseringstid till jämviktsfuktkvot och materialet går att låsa tvärs fiberriktningen i en treskiktskonstruktion. / To make wood harder it can be densified. This can be achieved by compression, the compressed material tends to return to the original shape when it is exposed to moisture fluxations and if no form of fixation occurs. The fixation can be done mechanically in a three-layer panel construction which reduce movements in the timber. These panels have been found to be unstable and previous attempts have shown deformations in form of cupping. This study aims to evaluate the conditions for using compressed aspen wood, and to provide a basis for development of a commercial product. Practical tests have been conducted to study hardness, springback and density of the compressed wood. In addition, three-layer panels have been developed to test whether it is possible to have a stable construction by varying the thickness of the buttom layer. Differences in acclimatisation time and the moisture contents effect on the springback has aslo been studied. The results show that the hardness of aspen wood after compression is in equal levels with beech and ashes, a low moisture contet provides a low springback, compressed timber have a longer time for acclimatisation and it is possible to fixate the material in the direction across the grain in a three-layer panel construction.
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Hårdgörning av Asp / Densification of Aspen WoodJohansson, Martin January 2008 (has links)
<p>Hårdgörning av trä syftar till att göra materialet hårdare. Detta går att åstadkomma genom komprimering, det komprimerade materialet tenderar dock att återgå mot sin ursprungsform då materialet utsätts för fukt om ingen låsning sker. Låsningen kan ske mekaniskt i en treskiktskonstruktion som motverkar träets fuktrörelser. Dessa skivor har dock visat sig vara instabila och tidigare försök har uppvisat deformationer i form av kupning. Denna undersökning syftar till att utreda förutsättningarna för att använda komprimerad asp samt att ta fram underlag för framtagning av en kommersiell produkt.</p><p>Praktiska tester har genomförts för att studera hårdhet, återfjädring och densitet hos det komprimerade virket. Vidare har treskiktsskivor tagits fram för att testa om det går att få en stabil konstruktion genom att variera tjockleken på spärrskiktet. Även skillnader i acklimatiseringstid och fuktkvotens inverkan för virkets återfjädring har studerats.</p><p>Resultaten visar på att aspens hårdhet efter komprimering blir i samma nivå som bok och ask, en låg fuktkkvot vid komprimering av materialet ger en låg återfjädring, komprimerat material har en längre acklimatiseringstid till jämviktsfuktkvot och materialet går att låsa tvärs fiberriktningen i en treskiktskonstruktion.</p> / <p>To make wood harder it can be densified. This can be achieved by compression, the compressed material tends to return to the original shape when it is exposed to moisture fluxations and if no form of fixation occurs. The fixation can be done mechanically in a three-layer panel construction which reduce movements in the timber. These panels have been found to be unstable and previous attempts have shown deformations in form of cupping. This study aims to evaluate the conditions for using compressed aspen wood, and to provide a basis for development of a commercial product.</p><p>Practical tests have been conducted to study hardness, springback and density of the compressed wood. In addition, three-layer panels have been developed to test whether it is possible to have a stable construction by varying the thickness of the buttom layer. Differences in acclimatisation time and the moisture contents effect on the springback has aslo been studied.</p><p>The results show that the hardness of aspen wood after compression is in equal levels with beech and ashes, a low moisture contet provides a low springback, compressed timber have a longer time for acclimatisation and it is possible to fixate the material in the direction across the grain in a three-layer panel construction.</p>
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