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Fiber Materials (fiber + material)
Selected AbstractsHydroxyapatite fiber material with BMP-2 gene induces ectopic bone formationJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2009Mitsumasa Oda Abstract Collagen containing bone morphogenetic protein-2 (BMP-2) expression vector, which is called "gene-activated matrix," promotes bone regeneration when transplanted to the bone defect. We speculated that hydroxyapatite fiber (HF) would be an ideal matrix for "gene-activated matrix" especially for bone regeneration, because it is oseteoconductive and has high affinity to DNA. The purpose of this study is to clarify whether HF containing BMP-2 expression vector induces ectopic bone formation. We prepared HF containing 0, 10, 50, and 100 ,g BMP-2 expression vector. Wistar male rats (8 weeks) were used and each rat received two HF implants in the left and right dorsal muscle. The rats were sacrificed 4, 8, and 12 weeks after the operation, and implants were analyzed radiographically by softex, dual-energy X-ray absorptiometry, and they were histologically examined. At 4 weeks, HF containing 50 or 100 ,g BMP-2 expression vector showed high bone mineral contents and large radiopaque volume compared to the other implants. At 8 and 12 weeks, HF containing 50 ,g BMP-2 expression vector exerted the highest values in the radiographic analyses. Bonelike tissue was histologically observed in HF containing 50 and 100 ,g BMP-2 expression vector groups but not detected in the other implants. The present results suggest that HF is potential as a matrix for "gene-activated matrix" for bone tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Impact of lubricant formulation on the friction properties of carbon fiber clutch platesLUBRICATION SCIENCE, Issue 1 2006R. C. Oldfield Since their introduction over ten years ago, carbon fiber based friction materials have been employed by transmission builders in a wide variety of applications, including torque converter clutches, synchronizers, limited slip devices and shifting clutches. This new generation of materials gives improved durability relative to cellulose; carbon fiber materials offer inherently greater wear resistance and improved resistance to thermal degradation. However, carbon fiber based materials also bring inherently different friction characteristics than their cellulose based counterparts. As a result, a different approach to lubricant formulation is required to provide optimized friction control in applications where they are used. It is well known that in order to achieve and maintain the required friction in a clutch, the correct combination of surface properties and additive chemistry is required. In this paper the impact of different additive chemistries on the friction of carbon fiber clutch plates has been investigated. It will be shown that with the appropriate choice of additive system, carbon fiber based friction plates can offer a number of performance improvements over more conventional materials. Copyright © 2006 John Wiley & Sons, Ltd. [source] Nanofiller-reinforced polymer nanocompositesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 8 2008J. Njuguna Abstract In this work, the technology of nano- and micro-scale particle reinforcement concerning various polymeric fiber-reinforced systems including polyamides (PAs), polyesters, polyurethanes (PUs), polypropylenes (pps), and high-performance/temperature engineering polymers such as polyimide (PI), poly(ether ether ketone) (PEEK), polyarylacetylene (PAA), and poly p -phenylene benzobisoxazole (PBO) is reviewed. When the diameters of polymer fiber materials are shrunk from micrometers to submicrons or nanometers, there appear several unique characteristics such as very large surface area to volume ratio (this ratio for a nanofiber can be as large as 103 times of that of a microfiber), flexibility in surface functionalities and superior mechanical performance (such as stiffness and tensile strength) compared to any other known form of the material. While nanoparticle reinforcement of fiber-reinforced composites has been shown to be a possibility, much work remains to be performed in order to understand how nanoreinforcement results in dramatic changes in material properties. The understanding of these phenomena will facilitate their extension to the reinforcement of more complicated anisotropic structures and advanced polymeric composite systems. Copyright © 2008 John Wiley & Sons, Ltd. [source] Innovative Catalysts for Oxidative Dehydrogenation in the Gas Phase , Metallic Short Fibers and Coated Glass Fabrics,CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2005R. Brüning Abstract The catalytic activity of metallic short fibers with chosen alloy components and textures was investigated in the oxidative dehydrogenation (ODH) of propane to yield propene, and of isopropanol to yield acetone. The short fibers were synthesized using a melt extraction process and the properties of the fibers were intensely characterized. A correlation between the structure and the catalytic activity of the material was established. Optical microscopic, DSC, XRD, REM and EDX methods were used to characterize the fibers. Selective results of the dependency of the temperature on the propane conversion are presented in this work. A yield of more than 35,% propene is obtained at a propane conversion of 50,%. The ODH of isopropanol to acetone occurred with attractive yields of over 80,%. The results demonstrate the high innovative potential of the metal fiber materials. The use of coated glass fabrics as catalysts for the ODH and total oxidation of propane were also part of this investigation. [source] | ||||||||||