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Special geometries, shapes

Both natural wood pulp fibres and staple viscose fibres dominate wet-laid filter media, and their pulp fibres are available from various lengths ranging from 1 to 12 mm in many special geometries and shapes these cross sections include traditional round, flat and grooved, ttilobal, C-shaped and V-shaped, hollow, and cross-shaped fibres. Round fibres with a smaller diameter have less impact on the pressure drop, and they have a positive influence on strength of paper filter made from wood pulp. Tri-lobal fibres have a similar influence on paper porosity to round fibres, but have improved particle capture capacities. [Pg.277]

Dewar heat load calculations involve a special geometry the outer surface of the reservoir and the inner surface of the vacuum container are so close together that each surface increment sees the other surface through a hemisphere. The ideal case is two concentric spheres, but two concentric cylinders or two parallel plane surfaces would behave similarly as long as their separation is small compared to their dimensions. The shape factor F.. is unity if the inner surface can see only the outer one. [Pg.61]

PVD-coated screws for highly loaded silica compounds are mainly used in Berstorff Multiplex extmsion lines. With these lines, the different compounds are led together and shaped in special prohle extmsion dies. Flow channels with optimized geometry ensure a uniform material flow of the individual prohle components. The extmsion tools Berstorff developed for this purpose are... [Pg.1014]

A special O-ring cell design is needed for in situ infrared (IR) vibrational characterization of an electrochemical interface. The absorption of one monolayer (i.e. <1015 cm 2 vibrators) can be measured if the silicon electrode is shaped as an attenuated total reflection (ATR) prism, which allows for working in a multiple-in-ternal-reflection geometry. A set-up as shown in Fig. 1.9 enhances the vibrational signal proportional to the number of reflections and restricts the equivalent path in the electrolyte to a value close to the product of the number of reflections by the penetration depth of the IR radiation in the electrolyte, which is typically a tenth of the wavelength. The best compromise in terms of sensitivity often leads to about ten reflections [Oz2]. [Pg.20]

Researchers can use computer programs to test the geometry of many molecular structures and determine their suitability for specific applications. For example, a specialized screen saver can check the shape of hypothetical molecules based on their suitability for cancer treatment. Anyone can upload the screen saver and use a computer s idle time... [Pg.572]

Filament-wound structures are typically cylindrical, spherical, or conical. In the case of cylindrical or conical shapes, there may be domed ends or specially wound flange ends. The fibers and resins can be selected from a wide variety of materials. These material and geometry options make filament winding a versatile manufacturing process. [Pg.392]

Usually, microfabrication techniques are used to prepare cantilevers with integrated tips of various shapes, mass and spring constants [197,198]. Depending on the cantilever geometry and material used to construct the cantilever [52], the frequency of commercial cantilevers typically varies from 15 kHz to more than 500 kHz, and the spring constants range from 0.01 to 100 N/m. Micromachining techniques can be used to prepare special probes such as meander-type cantilevers for bidirectional force microscopy [199]. [Pg.95]

As was demonstrated theoretically, a single atom at the end of a rigid tip is not stable as well as tips with an infinite aspect ratio do not exist [227,228]. Therefore, SFM tips are truncated and require a special procedure to calibrate their unknown geometry. Electron microscopy was widely employed for ex-situ examination of the tip shape [226,229,230]. This technique provides valuable information on the overall shape of the tip, however it is less suitable for characterisation of the nanometer sized probe apex. [Pg.97]

Several authors proposed to use a specially designed substrate for in-situ calibration of the tip shape based on extraction of the tip geometry from the topo-... [Pg.97]

Special attention should be paid to spherical geometry, since the mathematical treatment of spherical microelectrodes is the simplest and exemplifies very well the attainment of the steady state observed at microelectrodes of more complex shapes. Indeed, spherical or hemispherical microelectrodes, although difficult to manufacture, are the paragon of mathematical model for diffusion at microelectrodes, to the point that the behavior of other geometries is always compared against them. [Pg.121]


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See also in sourсe #XX -- [ Pg.143 ]




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Special geometries

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