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History-dependent structure in granular piles
Published in Y. Kishino, Powders and Grains 2001, 2020
Alexander Schinner, Hans-Georg Mattutis, Tetsuo Akiyama, Junya Aoki, Satoshi Takahashi, Keiko M. Aoki, Klaus Kassner
From the previous section, we can assume that the pressure dip for particles below 180 µm diameter in Ref. [6] were not caused by some polydispersity on the micrometer scale. The pressure dip seems to occurs only for glass bead with grain diameters below 460 µm. Cohesion changes the movement of grains from single particles to clusters of correlated particles. This was conjectured by experiments in Ref. [7] and corroborated by micromechanical simulations in Ref. [8]. In the Hosokawa powder tester (as proposed by Carr [9]), the strength of the cohesion and the surface roughness of the particles is classified by a single parameter, the fiowability. This flowability seems to be responsible why a system with 460 /µm diameter glass beads and less than 8 % deviation (Fig. 4) in diameter behaves is a monodisperse system and exhibits no pressure dip, whereas sand with the same diameter and size dispersion shows a pressure dip (Fig. 7). For the same reason, the monodisperse frosted glass beads in Ref. [6] with about 1 mm diameter diameter showed a pressure minimum.
Electricity
Published in Robert Routledge, Discoveries and Inventions of the Ninteenth Century, 2018
The arc electric light, as used for the illumination of streets and public places, is too intense and concentrated to be pleasant to the eye, and therefore it has been found necessary to surround it by globes of enamelled glass, or of porcelain, or of ground glass, or of frosted glass. By these expedients for diffusing and softening the light, it is rendered much more acceptable, but this advantage is gained at the cost of a considerable loss of the whole illuminating power, a loss which is, probably, never less than 10 per cent., but is usually much greater. The globes used in Paris, with the Jablochkoff candles, were of enamelled glass, and the apparatus was arranged, as shown in Fig. 280g, where it is partly represented in section, and with a part of the globe broken off, in order to show one of the candles placed in the holder which connects it with the circuit. In each lamp several candles were mounted, in some cases four; but the lamps in the Place de l’Opéra held twelve. At first there were mechanical arrangements, automatic and otherwise, by which, when the candle was burned down the current could be turned on to another. But M. Jablochkoff afterwards discovered that there was really no need for such a mechanism. For when the whole of the candles are simultaneously and equally connected with the circuit conductors, it is found that one of them will more easily transmit the current than any one of the rest, and when that particular one has once been lighted by the heat developed, the current will pass almost entirely through the arc, any loss through the connecting strip of carbon, at the tops of the other candles, being quite insignificant. When the first of the candles has burnt down completely, until the insulating porcelain holder separates the carbons, the current will at once re-establish itself at the top of one of the remaining carbons, and so on, while one is left.
Diagnostics
Published in Ronald Fayer, Lihua Xiao, Cryptosporidium and Cryptosporidiosis, 2007
Using Jenner or Giemsa stains, oocysts appear semitranslucent and stain blue to azure. They might contain four to six red or purple dots. “Ghost” forms with a frosted-glass appearance and usually devoid of granules might also be found. A narrow, clear halo might surround the oocyst.
Walking speed probability distribution in smoke-filled tunnel experiments
Published in Journal of the Chinese Institute of Engineers, 2022
Chen Li-Yu, Miho Seike, Nobuyoshi Kawabata, Masato Hasegawa, Shen-Wen Chien, Tzu-Sheng Shen
where, I0: intensity of incident light (non-smoke), I: intensity of transmitted light, and distance traveled by light through the gas (0.8 m). A 660-nm-red laser was used as the light source. The Cs was confirmed using frosted glass with transmittances of 10%, 20%, 30%, 40%, and 50%.