388 research outputs found

    Observation of machined surface and subsurface structure of hinoki (Chamaecyparis obtusa) produced in slow-speed orthogonal cutting using X-ray computed tomography

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    First online: 01 January 2015X-ray computed tomography (CT) was applied to non-destructive observation of machined surface and subsurface structure of hinoki (Chamaecyparis obtusa) produced in slow-speed orthogonal cutting. The cutting experiments were conducted under several cutting conditions and the chip formations were observed with a high-speed camera to be classified into four chip types. The difference in the quality of the machined surfaces produced in four types of chip formation was investigated. During type 0 chip formation, the workpiece was cut almost exactly at the path of the cutting edge, so no deformation was found on and beneath the machined surface. During type I chip formation, the direction of the fore-split, which is dependent on the arrangement of cells, determined the machined surface. During type II chip formation, the cutting tool sometimes tore part of the workpiece below the path of the cutting edge and the tore part was then compressed by the tool, remaining on the machined surface. During type III chip formation, part of the workpiece above the path of the cutting edge was compressed by the tool, instead of being removed as a chip, so the compression occurred in wide area. The relationship between the formation of the machining defects such as torn grain or the compressed cells and the way chip is separated, deformed, or removed was clarified in this study

    Nitrogen doping into titanium dioxide by the sol-gel method using nitric acid

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    N-doped TiO(2) has been prepared by use of sol-gel systems containing titanium alkoxide, with nitric acid as the nitrogen source. The time needed for gelation of the systems was drastically reduced by ultrasonic irradiation. The peaks assigned to the nitrate and nitrous ions were observed by FT-IR measurement during the sol-gel reaction. The N-doping was confirmed by the observation of N-O peaks in the XPS spectrum of the sample heated at 400 A degrees C. The nitrate ion acted as an oxidizer of the ethanol solvent and titanium species. The TiO(2) became doped with nitrogen oxide species as a result of reduction of nitrate ion incorporated into the dried gel samples. These results indicated that the added nitric acid was reduced during the sol-gel transition and heating process, and the resulting NO species were situated in the titania networks. The UV and visible photocatalytic activity of the samples was confirmed by the degradation of trichloroethylene.ArticleRESEARCH ON CHEMICAL INTERMEDIATES. 37(8):869-881 (2011)journal articl
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