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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

Knoop microhardness of diaphyseal bone

Riches, Philip Edward January 1998 (has links)
No description available.
2

Study on the Difference of Collagen Fibre Structure Caused by Epoxy Resin Embedding

Lu, Jianmei, Hua, Yuai, Zhang, Huayong, Cheng, Jinyong, Xu, Jing, Li, Tianduo 26 June 2019 (has links)
Content: The research on Collagen that possesses unique fibre structure are reported frequently. In this paper, the cross image of leather fibre of dried wet blue cowhide embedded with and without epoxy resin were investigated with micro computed topography(MCT). The images obtained by MCT of leather fibre are original status without any damage, while the embedded leather can emerge distortion because the fibre was fixed during the solidifying and immersing of the resin. In this research, 2357 images of leather fibre were investigated on wet blue leather(original fibre) and the same piece of leather embedded by epoxy resin(embedded fibre). The area ratio of the sections from the original fibre and the embedded fibre was examined for each image. The statistic results showed that the mode of area ratio of the original fibre section to the entire fibre section is 75%, and the mode of area ratio of the embedded fibre section to the embedded fibre entire section is only 48%. The mode of the area ratio of the original fibre is obviously higher than the mode of the area ratio of the embedded fibre, that is diverse with the anticipation of fibre swelling caused by resin. The reason might be the expansion of interval space among the fibre filled with epoxy resin, otherwise the conglutination of fibre caused by the evaporation of solvent(acetone used in embedding) in the course of the resion solidifying. Likewise, it can be the adhesion of the tiny fibre with the larger fibre that will diminish the area caculated. The factors will be studied further on embedding to achieve a method with minimum deformation on cross image of fibre. Take-Away: The area ratio of cross section on embedded fibre shrunk comparing with the original fibre, that is out of anticipation of the probable swelling created by resin.
3

Fibres from Reindeer Tendons : Mechanical and retting processes for extractning collagen fibres / Fibrer från Rensenor : Mekaniska processer och rötningsprocesser för att extrahera kollagenfibrer

Lindh, Alice, Blomberg, Pontus January 2021 (has links)
Collagen fibres from reindeer tendons can be used to create threads. These threads have traditionally been used in Sápmi crafts. Due to the high cost of manual extraction, tendon-based threads have been replaced with cheaper synthetic threads. However environmental concerns have been raised within the Sápmi crafts communities regarding the synthetic threads. To mitigate the impacts of synthetic threads and to better utilize the reindeer after slaughter a more efficient fibre extraction process has been sought after. In this study two venues have been investigated, softening and retting. In this study softening will refer to the breaking of bonds through the use of a liquid. Retting will refer to a controlled degradation of a material through biological processes. Softening and retting aided mechanical extraction of collagen fibres. The softening, using water and in some cases polyethylene glycol, reduced entanglement and friction. The retting can be divided into short term retting and long-term retting, up to six weeks. Neither the short-term retting nor the long-term retting did facilitate the extraction significantly compared to a simpler softening treatment. Softening on the other hand made extraction easier. A 70 hour softening with water at room temperature had the largest impact. The extraction became slightly easier when the samples were further softened with polyethylene glycol. This was compared to a reference sample where water was used for further softening. Mechanical fibre extraction methods were also evaluated. The softened tendon samples were calendered between two rollers at 1.2 bar and 5.0 bar. The samples using the higher pressure were easier to separate. The samples were then manually torn apart into fine fibre bundles. Many of the manual methods used can be automated but they would need specialized equipment. The mechanically extracted fibres were then spun into yarns through hand spinning with moistened fingers. The tensile properties of the fibres and the yarns were determined. The fibres and the yarns were also evaluated through light microscopy. Both the yarns and fibres showed a high degree of variation in the tensile tests. The use of manual methods likely contributed to the high variation. The yarns slipped which caused a lower tenacity compared to the fibres. The mean fibre tenacities were between 17-20 cN/tex, depending on factor. Neither of the factors were significantly different. The elasticity of the fibres varied to a large extent. The fibres exhibited an almost fully elastic deformation until break. The fibres were white to cream and slightly translucent when viewed in a light microscope. The yarns were uneven and glossy.

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