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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.
1

Stabilisering av insektsangripna möbler : en jämförande studie av konsolidanter

Nolin, Cecilia January 2009 (has links)
<p>Denna rapport är en jämförande studie av utvalda konsolidanter som används till att stabilisera nedbrutet insektsangripet trä. Av de trägnagande skadeinsekter vi har i Sverige är det främst<em> </em>den<em> </em>strimmiga trägnagaren som är intressant i möbelsammanhang. I rapporten beskrivs den strimmiga trägnagaren, en liten skadeinsekt<strong> </strong>som kan åstadkomma stor skada om den får verka ostörd. Insekten finns utspridd i hela Europa och är ett stort problem då den angriper alla typer av träslag. Nedbrutet insektsangripet trä<strong> </strong>förlorar sin styrka och kan behöva konsolideras genom att injicera konsolidanter in i träet. Studien är tänkt att jämföra styrkan på de vanligast förkommande och använda konsolidanterna. Urval av dessa har dels gjorts genom att intervjua konservatorer i Sverige, Norge och Danmark, dels utifrån tillgänglig litteratur och forskning. I studien injiceras de utvalda konsolidanterna in i provbitar av artificiellt konstruerat insektsangripet trä som sedan utsätts för hållfasthetsprover. Provbitarna är utformade i kuber av björk, 45x45x45 mm och är borrade med 2 mm stora hål för att efterlikna angripet trä. Två olika typer av hållfasthetsprov har använts för att mäta styrkan hos de olika konsolidanterna, tryckhållfasthet tvärsfiber och skjuvhållfasthet. Resultaten av hållfasthetsproverna visar inga tydliga tecken på att de injicerade konsolidanterna gett någon direkt styrka till provbitarna. I tryckhållfasthets tvärsfiber finns en dock en tendens tillförhöjda värden. För att kunna dra någon slutsats bör ytterligare studier genomföras.</p> / <p>This report is a comparative study of a chosen set of consolidating agents used to stabilize wood suffering from the infestation of wood boring insects. When considering furniture, the most common wood boring insect in Sweden is the Furniture Beetle. This report discusses the Furniture Beetle, a small insect which if left alone, achieves a great amount of damage. This particular beetle can be found in all of Europe and is a sizable problem, since it can attack all species of wood. Infested wood is destabilized by the beetles boring a web of internal tunnels throughout, which results in a loss of strength. This wood is then commonly injected with a consolidation agent to compensate for its internal weakness. The study is made to compare the strength of the most commonly used consolidating agents. These lection of agents was determined by interviewing conservators in Sweden, Norway and Denmark, as well as from accessible literature and research. In the study the selected consolidating agents are injected into trial pieces of artificially compromised wood which are in turn exposed to strength testing in a laboratory setting. The trial pieces are squares of birch wood measuring 45x45x45mm which have several 2mm holes drilled into them lengthwise, to simulate the beetle's pathways. Two types of strength testing were carried out to test the consolidation agents and their effect. One testmeasures the strength by compression across the grain, while the other puts pressure on either side, forcing the piece to fail along the grain. The results of the testing do not distinctively show that the consolidating agents impose any significant strength to the trial pieces. There is however a tendency of increased strength shown in the cross grain compression tests. To draw any firm conclusions, additional research is required.</p>
2

Stabilisering av insektsangripna möbler : en jämförande studie av konsolidanter

Nolin, Cecilia January 2009 (has links)
Denna rapport är en jämförande studie av utvalda konsolidanter som används till att stabilisera nedbrutet insektsangripet trä. Av de trägnagande skadeinsekter vi har i Sverige är det främst den strimmiga trägnagaren som är intressant i möbelsammanhang. I rapporten beskrivs den strimmiga trägnagaren, en liten skadeinsekt som kan åstadkomma stor skada om den får verka ostörd. Insekten finns utspridd i hela Europa och är ett stort problem då den angriper alla typer av träslag. Nedbrutet insektsangripet trä förlorar sin styrka och kan behöva konsolideras genom att injicera konsolidanter in i träet. Studien är tänkt att jämföra styrkan på de vanligast förkommande och använda konsolidanterna. Urval av dessa har dels gjorts genom att intervjua konservatorer i Sverige, Norge och Danmark, dels utifrån tillgänglig litteratur och forskning. I studien injiceras de utvalda konsolidanterna in i provbitar av artificiellt konstruerat insektsangripet trä som sedan utsätts för hållfasthetsprover. Provbitarna är utformade i kuber av björk, 45x45x45 mm och är borrade med 2 mm stora hål för att efterlikna angripet trä. Två olika typer av hållfasthetsprov har använts för att mäta styrkan hos de olika konsolidanterna, tryckhållfasthet tvärsfiber och skjuvhållfasthet. Resultaten av hållfasthetsproverna visar inga tydliga tecken på att de injicerade konsolidanterna gett någon direkt styrka till provbitarna. I tryckhållfasthets tvärsfiber finns en dock en tendens tillförhöjda värden. För att kunna dra någon slutsats bör ytterligare studier genomföras. / This report is a comparative study of a chosen set of consolidating agents used to stabilize wood suffering from the infestation of wood boring insects. When considering furniture, the most common wood boring insect in Sweden is the Furniture Beetle. This report discusses the Furniture Beetle, a small insect which if left alone, achieves a great amount of damage. This particular beetle can be found in all of Europe and is a sizable problem, since it can attack all species of wood. Infested wood is destabilized by the beetles boring a web of internal tunnels throughout, which results in a loss of strength. This wood is then commonly injected with a consolidation agent to compensate for its internal weakness. The study is made to compare the strength of the most commonly used consolidating agents. These lection of agents was determined by interviewing conservators in Sweden, Norway and Denmark, as well as from accessible literature and research. In the study the selected consolidating agents are injected into trial pieces of artificially compromised wood which are in turn exposed to strength testing in a laboratory setting. The trial pieces are squares of birch wood measuring 45x45x45mm which have several 2mm holes drilled into them lengthwise, to simulate the beetle's pathways. Two types of strength testing were carried out to test the consolidation agents and their effect. One testmeasures the strength by compression across the grain, while the other puts pressure on either side, forcing the piece to fail along the grain. The results of the testing do not distinctively show that the consolidating agents impose any significant strength to the trial pieces. There is however a tendency of increased strength shown in the cross grain compression tests. To draw any firm conclusions, additional research is required.
3

Coleoptera aquáticos associados a troncos submersos em córregos de baixa ordem localizados em diferentes tipos de vegetação do Estado de São Paulo

Valente Neto, Francisco 04 March 2011 (has links)
Made available in DSpace on 2016-06-02T19:31:54Z (GMT). No. of bitstreams: 1 3590.pdf: 1498556 bytes, checksum: e35a7d27b705eabeb03c860c8df85ec0 (MD5) Previous issue date: 2011-03-04 / Universidade Federal de Sao Carlos / Riparian vegetation is source of wood debris in streams so variation in vegetation type promote difference in biomass and richness of these substrates, which affect composition and abundance of insects associated with submerged wood. Aquatic Coleoptera associated with submerged wood debris is pointing out to it importance in the wood breakdown. For evaluated if the vegetation type influences community of aquatic Coleoptera associated with submerged wood debris, we collected submerged wood in eight Atlantic Rainforest streams, eight Cerrado streams and we include two Semideciduous Forest streams. We applied different statistical analysis (redundancy analyses, PERMANOVA and partitioning variation) to test if the taxonomic composition in Cerrado streams was different from Atlantic Rainforest streams and to verify what cause this possible difference, environmental variables, spatial variables or both. We found 1617 organisms distributed in 12 families and 29 genus. We found two boring genus of submerged wood debris for Neotropical region, Lutrochus and Stegoelmis, which play important role to food chain of streams, due to availability of nutrients and microhabitats at wood. The results of taxonomic composition of aquatic Coleoptera associated with submerged wood debris showed differences between Atlantic Rainforest and Cerrado streams, exhibiting that the vegetation type is important factor for the composition of this community. We argued that this is because of differences in composition and structure of vegetation, which cause differences in richness and biomass of submerged wood in streams. / A mata ripária é fonte de troncos e galhos para os córregos, de modo que variações nessa vegetação geram diferenças na biomassa e na riqueza desses substratos, interferindo na composição e abundância de insetos associados a troncos submersos. Coleoptera aquáticos associados a troncos submersos se destacam no processo de decomposição de troncos submersos, através de comportamento alimentar (raspar), que favorece a instalação de micro-organismos e consequentemente aumenta a riqueza e abundância de macroinvertebrados em troncos. Para testar se o tipo de vegetação interfere na fauna de Coleoptera aquáticos associados a troncos submersos nós coletamos este substrato em 18 córregos, oito em áreas de Cerrado, oito em áreas de Mata Atlântica e em outros dois de Floresta Estacional Semidecidual. Aplicamos diferentes análises estatísticas (análise de redundância exploratória, PERMANOVA e análise de partição de variância) para testar se a composição taxonômica dessa fauna em córregos de Cerrado difere daquela de Mata Atlântica e para verificar se essa possível diferença se deve a variáveis ambientais, variáveis espaciais ou ambas. Encontramos 1617 organismos, distribuídos em 12 famílias e 29 gêneros, com destaque para dois gêneros minadores de troncos para a região Neotropical, Lutrochus e Stegoelmis, que desempenham função importante para a cadeia trófica dos córregos, pela disponibilização de nutrientes e pela capacidade de produzir ranhuras e galerias. Constatamos diferenças na composição taxonômica de Coleoptera aquáticos associados a troncos, indicando que o tipo de vegetação é importante na composição dessa fauna, principalmente devido a diferenças na composição e na estrutura da vegetação, que refletem diferenças na riqueza e na biomassa de troncos submersos em córregos.

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