Fibre tapered

Center for Healthcare Technologies at Lawrence Livermore National Laboratory in Livermore, potentially capable to measure pH at or near the stroke site29. The probe is the distal end of a 125 pm fibre tapered up to a diameter of 50 pm. A fluorescent pH-indicator, seminaphthorhodamine-1-carboxylate, is embedded inside a silica sol-gel matrix which is fixed to the fibre tip. Excitation of the dye takes place at 533 nm and the emission in correspondence of the acid (580 nm) and basic (640 nm) bands are separately detected. The use of this ratiometric technique obviates worrying about source fluctuations, which have the same effects on the two detected signals. The pH sensor developed was first characterised in the laboratory, where it showed fast response time (of the order of tens of seconds) and an accuracy of 0.05 pH units, well below the limit of detection necessary for this clinical application (0.1 pH units). The pH sensor was also tested in vivo on rats, by placing the pH sensor in the brain of a Spraque-Dawley rat at a depth of approximately 5 mm30. 

Zalvidea, D., Diez, A., Cruz, J.L. and Andres, M.V., A wavelength multiplexed hydrogen sensor based on a palladium-coated fibre taper and a Bragg grating, Electron, 40, 301, 2004. 

Zalvidea D, Dfez A, Cruz JL, Andres MV (2004) Wavelength multiplexed hydrogen sensor based on paUadinm-coated fibre-taper and Bragg grating. Electron Lett 40(5) 301-302... 

Mackenzie, H. S. Payne, F. P., Evanescent field amplification in a tapered single mode fibre, Electron. Lett. 1990, 26, 130 132... 

Features Erect, smooth, angular, brown-spotted stem, two to three feet high. Leaves opposite, stalked, smooth, serrate, usually in three or five segments. Flowers (July to September) in terminal heads, small, tawny. Numerous seeds, four-cornered, reflexed prickles. Root tapering, many-fibred. 

Initially, the performance of the PMP sensor was evaluated with a 1/2 metre monochromator equipped with a CCD detector to obtain figures of merit. The sensor was also evaluated using a fibre optic spectrometer from Ocean Optics, Model S2000. The sensor used to determine the limit of detection (LOD) consisted of a 400 mm optical fibre with a tapered end. A 50-75 mm layer of the 3 mole % complex polymer was directly deposited onto the tapered end without vinyl-silanisation. Using 1 mW of 465.8 nm for excitation, 200 pm entrance slits of the... 

Fig. 19.8. SEM image of an imprinted polymer-coated tapered 400 pm optical fibre at a magnification of 60 x. ...

ISO, Standard test method for mode I interlaminar fracture toughness, G/c, of unidirectional fibre-reinforced polymer matrix Composites. ISO 15024 2001. Blackman, B.R.K., H. Hadavinia, A.J. Kinloch, M. Paraschi and J.G, Williams, The calculation of adhesive fracture energies in mode I revisiting the tapered double cantilever beam (TDCB) test. Engineering Fracture Mechanics 2003. 70 p. 233-248. BSI, Determination of the mode I adhesive fracture energy, Gic, of structural adhesives using the double cantilever beam (DCB) and tapered double cantilever beam (TDCB) specimens. 2001. BS 7991. 

Fibres make up a high proportion of the volume of most hardwoods. Fibres are imperforate, axially-elongated cells, with small lumens and ends that taper into pointed tips. The density of a hardwood is largely determined by the proportion of fibres to other cell types present in the wood. In a low density wood, the vessels occupy a major proportion of the wood volume, whereas denser woods have a larger proportion of thick-walled fibres. The secondary walls of fibres are usually sparsely pitted and the cells lack cell contents at functional maturity. 

Flax fibres are multicellular, with each cell having tapering ends and a narrow lumen. The fibres show longitudinal striations and nodes (Fig. 1-13). The ultimate... 

Each hair consists of a single elongated cell. The upper end tapers to a point whilst the lower end is open where it has been removed from the seed by the gin. As is apparent in Fig. 3.3, the fibre contains many convolutions throughout its length. By microscopic examinations, differential staining, and the action of swelling agents, it is possible to discern four... 

Hale Z M and Payne F P 1994 Fluorescent sensors based on tapered single-mode optical fibres Sensors Actuators 17 233 0 Luo S and Walt D R 1989 Avidin-biotin coupling as a general method for preparing enzyme-based fiber-optic sensors Anal. Chem. 61 1069-72 Li L and Walt D R 1995 Dual-analyte fiber-optic sensor for the simultaneous and continuous measurement of glucose and oxygen Anal. Chem. 67 3746-52 Tan W, Shi Z-Y, Smith S, Bimbaum D and Kopelman R 1992 Submicrometer intracellular chemical optical fiber sensors Science 258 778-81 Tan W, Shi Z-Y and Kopelman R 1992 Development of submicron chemical fiber optic sensors Anal. Chem. 64 2985-90... 

Vacuum window Phosphor Fibre-optic taper CCD chip Electonics Cooling block... 

Then the impregnated fibres are squeezed into a long die which is tapered along the passage. This tapering enables... 

Figure 5. SEM micrograph of a 7 pm crystal of zeolite A (about 2500 unit cells on an edge) glued to a hoUow glass fibre that tapers to a point of < 1 pm (left hand bar at lower right is 1pm). This mount is typical of those used in microcrystal diffraction experiments.

In the Usui process for producing tapered pipes, the glass fibre reinforcement is wound round a tapered mandrel to make a preform. This is inserted into the mould in the centrifugal machine and the mandrel removed. Resin is poured in and the mold tilted to a pre-determined angle and then rotated until the resin has cured. 

As step-lap joints have similar features to lap and donble-lap Joints, every design aspect that has been indicated in the design of lap Joints shonld also be considered in the design of step-lap joints. In step-lap Joints factors snch as fibre orientation on the bond surface still have a major effect on the Joint strength (see 5.3.1.4), while tapering the adherend ends becomes irrelevant. 

Width-tapered beam The value of dClda is now made constant because of a variation in width with crack length, rather than the beam height - this is very useful when using fibre-composite substrates (see Fig. 2c). 

Composite parts Solid composite parts may be repaired by making carefully tapered scarf joints. Hot-bonded repairs are preferred provided that the surface is first adequately dried." Parts made from structural fibres, that is, carbon fibre, Kevlar or boron fibres and some glass-fibre parts require that each repair layer be of the same type as the original, or a direct equivalent, and laid up in the correct orientation. 

---