# siphon

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## siphon

(sī`fən, –fŏn), tube or other enclosed conduit through which a liquid is lifted over an elevation and then emptied at a lower level. The movement of the liquid is driven primarily by the force of gravity. A siphon is typically shaped like an inverted J or U; to operate, it must discharge at a level lower than that of the liquid's surface on the intake side. The siphon must be filled before it will operate; suction is sometimes used initially to draw a liquid into a empty siphon.

## Siphon

a bent tube with legs of different lengths, through which a liquid flows from a vessel at a higher leveito a vessel at a lower level (see Figure 1). In order to start the operation, the siphon must first be filled with the liquid. The action of a siphon results from the fact that the pressure on the liquid volume filling the upper (hatched) section of the siphon applied from the direction of the upper reservoir, that is, from the left, is higher than that applied from the direction of the lower reservoir, that is, from the right. Thus, at the moment when the flow starts, the pressure on the left is equal to p0γh1 and the pressure on the right is equal to p0 - γh2, where γ is the specific weight of the liquid, p0 is the pressure on the free surface of the liquid, and h2 > h1. In this manner, when the liquid is flowing

Figure 1. Diagram of the operation of a siphon

through the siphon, a pressure is established in the upper section that is lower than p0. The greater the difference in the heights h2 - h1 and the greater the liquid’s energy loss in overcoming the resistance of the tube, the greater the pressure drop in the upper section. This circumstance limits the difference in the heights of the liquid and, consequently, the operation of the siphon; when the pressure in the flow is below a certain limit, the column of liquid is disrupted. When cold water at atmospheric pressure is being transferred by a siphon, the maximum difference in the heights is usually no more than 6 to 7 m.

## siphon

[′sī·fən]
(botany)
A tubular element in various algae.
(engineering)
A tube, pipe, or hose through which a liquid can be moved from a higher to a lower level by atmospheric pressure forcing it up the shorter leg while the weight of the liquid in the longer leg causes continuous downward flow.
(geology)
A passage in a cave system that connects with a water trap.
(invertebrate zoology)
A tubular structure for intake or output of water in bivalves and other mollusks.
The sucking-type of proboscis in many arthropods.

## siphon

, syphon
1. a tube placed with one end at a certain level in a vessel of liquid and the other end outside the vessel below this level, so that atmospheric pressure forces the liquid through the tube and out of the vessel
2. See soda siphon
3. Zoology any of various tubular organs in different aquatic animals, such as molluscs and elasmobranch fishes, through which a fluid, esp water, passes
References in periodicals archive ?
Within the Busycotypus canaliculars fishery, breakage of the siphonal canal prevents accurate SL measurement giving rise to management interest in SW measurement for regulatory MLS.
He mentioned as main shell differences in Bulliinae the lack of a recurved siphonal channel with a carina on the dorsal side of the fasciole, and the reduced ornamentation.
Nucella trancosana is a low-spired thick-shelled species with strong apertural teeth that extend into the aperture as ribs, a short siphonal canal, and numerous spiral cords (up to 24) on the body whorl.
APLEN Aperture length, the length from the suture of the aperture to the tip of the siphonal canal.
Sipho thick basally narrower distally; siphonal capsule very weakly hook shaped with opposite arm distinctly large broader cylindrical while adjacent arm very small narrow; median lobe narrow apically slightly longer than parameres; trabes apically bifurcated.
The densities found during the research activities for this article can only confirm a decrease in population density and mean siphonal length of conchs.
41; whorls strongly convex with narrow angular shoulder, and undulant, fairly deep suture, base of last whorl without a waist-like constriction; rostrum narrow, without a fasciole; aperture narrowly elliptical; siphonal canal strongly contracted but slightly expanded terminally, end truncate, oblique in dorsal view, not notched.
bugensis in the anatomy of the siphonal region, but it remains to be seen if this character state endures future scrutiny, especially among populations occurring within the native range of Dreissena spp.
For each individual, the Lt was measured from the tip to the base of the siphonal canal, and the sex was determined.
The shell is thick and conical; central apex smooth, the outer margin is nearly smooth with faintly marked siphonal groove.
Abyssochrysoids with tall shell, predominating spiral sculpture, multispiral, probably planktotrophic, multispiral protoconch; aperture with no trace of siphonal canal.

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