Word Finder - valves

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A device that controls the flow of a gas or fluid through a pipe.

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A device that admits fuel and air into the cylinder of an internal combustion engine, or one that allows combustion gases to exit.

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One or more membranous partitions, flaps, or folds, which permit the passage of the contents of a vessel or cavity in one direction, but stop or control the flow in the opposite direction

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the ileocolic, mitral, and semilunar valves

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One of the leaves of a folding-door, or a window-sash.

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A vacuum tube.

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One of the pieces into which certain fruits naturally separate when they dehisce.

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A small portion of certain anthers, which opens like a trapdoor to allow the pollen to escape, such as in the barberry.

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One of the pieces or divisions of bivalve or multivalve shells.

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One of the two similar portions of the shell of a diatom.

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To control (flow) by means of a valve.

The valves are distinguished as dorsal and ventral.

The frui t is a pod or siliqua splitting by two valves from A "0 D FIG.

The two valves of the shell of the common cockle are similar to each other, and somewhat circular in outline.

These spiracles have firm chitinous edges, and can be closed by valves moved by special muscles.

The manufacture of springs, valves and washers does not require any very special notice, these articles being generally fashioned out of mixed rubber, and vulcanized either in moulds or in powdered French chalk.

This machine reproduces a copy of the original transmitting slip, which can be passed on to any other Wheatstone circuit or can be run through a " Creed printer," which is a pneumatic machine actuating a typewriter by means of valves.

In the Trimerellidae, for example, some of the muscles are attached to a massive or vaulted platform situated in the medio-longitudinal region of the posterior half or umbonal portion of both valves.

The function of this pair of muscles is the closing of the valves.

Two other pairs have been termed divaricators by Hancock, or cardinal muscles (" muscles diducteurs " of Gratiolet), and have for function the opening of the valves.

In the Testicardines, where no such sliding action of the valves was necessary or possible, no muscles for such an object were required, consequently none took rise from the lateral portions of the valves as in Lingula; but in an extinct group, the Trimerellidae, which seems to be somewhat intermediate in character between the Ecardines and Testicardines, have been found certain scars, which appear to have been produced by rudimentary lateral muscles, but it is doubtful (considering the shells are furnished with teeth, though but rudely developed) whether such muscles enabled the valves, as in Lingula, to move forward and backward upon each other.

By the contraction of the valves the small smooth seeds, which form FIG.

For high heads the water cylinders, valves and valve chambers are specially constructed to withstand heavy pressures, water being sometimes raised in a single lift to heights of more than 2000 ft.

Hydraulic pumping engines, while not differing essentially from steam pumps, must have specially designed valves in the power cylinder on account of the incompressibility of water.

The adjustment of the air currents in the different splits is affected by regulators which are placed in the return air-ways, and act as throttle valves to determine the volume of air in each case.

The simplest forms of pumps employed for forcing liquids are "plunger pumps," consisting essentially of a piston moving in a cylinder, provided with inlet and outlet pipes, together with certain valves.

The 'disposition of these valves divides this type of pump into suction pumps and force pumps.

E is a valve in the inlet pipe opening into the cylinder; and A the piston is perforated by one or more holes, each fitted with valves opening outwards on its upper surface.

In practice it may be considerably less, owing to leakage at the valves and between the piston and cylinder.

The cylinder, in which a well-fitting piston worked, was provided at its lower end with two valves.

This type of pump is, however, not very efficient, for there is not only leakage about the valves and between the piston and cylinder, but at a certain degree of exhaust the air within the vessel is insufficient to raise the inlet valve; this last defect has been met in some measure by using an extension of the piston to open and close the valve.

Neisen and others to introduce glass valves in lieu of stop-cocks.

Below each retort, and attached to it, is a cooler formed of thin sheet-iron, which receives the hot char as it passes from the retort, and at the bottom of the cooler is an arrangement of valves which permits a certain amount of char to drop out and no more.

The small ova are crowded beneath the dorsal part of the valves.

A very few have the power of swimming by opening and shutting the valves of the shell (Pecten, Lima); most can crawl slowly or burrow rapidly; others are, when adult, permanently fixed to stones or rocks either by the shell or the byssus.

The valves of the shell have been removed by severing their adhesions to the muscular areae h, i, k, 1, m, u.

In removing the valves of the shell from an Anodonta, it is necessary not only to cut through the muscular attachment of the body-wall 4 ?"

It is on this account that the valves of a dead Lamellibranch always gape; the elastic ligament is no longer counteracted by the effort of the adductors.

Whilst the valves of the shell are equal in Anodonta we find in many Lamellibranchs (Ostraea, Chama, Corbula, &c.) one valve larger, and the other smaller and sometimes flat, whilst the larger shell may be fixed to rock or to stones (Ostraea, &c.).

A further variation consists in the development of additional shelly plates upon the dorsal line between the two large valves (Pholadidae).

It is to be remembered that the whole of the cuticular hard product produced on the dorsal surface and on the mantle-flaps is to be regarded as the " shell," of which a median band-like area, the ligament, usually remains uncalcified, so as to result in the production of two valves united by the elastic ligament.

In Aspergillum the whole of the tubular mantle area secretes a continuous shelly tube, although in the young condition two valves were present.

This deficiency is very usual in the class; at the same time, many Lamellibranchs have tentacles on the edge of the mantle supplied by a pair of large well-developed nerves, which are given off from the cerebro-pleural ganglion-pair, A, When free swimming, shows the two dentigerous valves widely open.

The glochidium quits the gillpouch of its parent and swims by alternate opening and shutting of the valves of its shell, as do adult Pecten and Lima, trailing at the same time a long byssus thread.

Lima; members of this genus form a nest by means of the byssus, or swim by clapping the valves of the shell together.

Chamidae.-Shell with sub-equal valves and prominent umbones more or less spirally coiled; ligament external.

This has led to the loss of the radula, and is accompanied by the division of the shell into two valves.

Heat is regulated in the structures by means of valves on the various branch pipes.

The extinct Gryptochitonidae, Pilsbry, with other Palaeozoic genera, narrow and elongated in form with terminal margins of end valves elevated, belong to this group.

No shell-eyes, slits in the valves 1-7 corresponding with the ribs of the tegmentum.

Valves immersed in the girdle, with small tegmentum.

Vermiform, with thick girdle and small valves; insertion and sutural plates strongly drawn forward, sharp and smooth.

This appears to indicate that the Neomeniomorpha are descended from Chiton-like ancestors, and that they have lost their shell valves.

The next important step seems to have been taken in the 4th century when some forgotten Watt devised valves for the bellows.

The air and gas, the latter coming from the gas producers or other source, arrive through H and J respectively, and their path thence is determined by the position of the reversing valves K and K'.

In the position shown in solid lines, these valves deflect the air and gas into the left-hand pair of "regenerators" or spacious heat-transferring chambers.

The ovary is incompletely divided into many chambers by the ingrowth of the placentas which bear numerous ovules and form in the fruit a many-seeded short capsule opening by small valves below the upper edge.

The valves are hydroscopic, responding to increase in the amount of moisture in the atmosphere by closing the apertures.

In dry weather the valves open, and the small seeds are ejected through the pores when the capsule is shaken by the wind on its long stiff slender stalk.

The pollen is set free by the opening (dehiscence) of the anther, generally by means of longitudinal slits, but sometimes by pores, as in the heath family (Ericaceae), or by valves, as in the barberry.

The three valves bear the septa in the centre and the opening takes place through the back of the chambers.