trap

trap

¹

1. a mechanical device or enclosed place or pit in which something, esp an animal, is caught or penned

2. a device that hurls clay pigeons into the air to be fired at by trapshooters

3. Golf an obstacle or hazard, esp a bunker

4. Jazz slang percussion instruments

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trap

², traprock

1. any fine-grained often columnar dark igneous rock, esp basalt

2. any rock in which oil or gas has accumulated

Trap

A bend in a soil drain, arranged in such a manner that it is always full of water, which provides a water seal and prevents odors from entering back through the pipes.

Trap

 

a device for capturing wild animals and birds. There are traps that require the attendance of a person and there are those that are actuated by a trigger mechanism (unattended traps). The first group includes various types of nets for capturing the animals live. The second group comprises three types of traps: those that crush, those that grasp, and those that capture live.

There are three kinds of traps (deadfalls) that crush the animal. One is used in the tundra to capture arctic foxes and, more rarely, other animals. It consists of a floor, two walls, and a weight held by a trigger mechanism. The other two operate on the same principles; one of them is used for capturing both small (squirrel, sable) and large (wolf, bear) animals, while the other is used only for small animals (squirrel, sable, Siberian weasel, polecat).

There are three kinds of traps that grasp the animal. One is the steel-jaw trap (seeSPRING TRAP). The second is the noose, which is set across game trails or at den openings to capture rabbits, small rodents, and game birds. The noose entraps the animal and is tightened by the animal’s movements. The third type operates with the aid of a taut crossbow, whose force presses the animal against the trap’s crosspiece.

There are a number of traps for capturing animals live. The box-type trap is one. It is of various sizes and designs and is used for capturing many economically important animals, such as muskrat, coypu, and mink. Rabbit warrens and pitfalls are sometimes used in hunting regions to capture capercailles, grouses, and partridges.

Many traps that were used in prerevolutionary Russia have been banned because they led to the killing of a great number of animals and in some cases proved to be dangerous to humans.

REFERENCE

Rakhmanin, G. E. Tekhnika dobychi promyslovykh zhivotnykh samolovami. Moscow, 1951.

S. A. LARIN

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Trap

 

(also traprock), the group designation of basic igneous rocks with a characteristic stair-step jointing.

Traps include such rocks as diorite, gabbro-diorite, gabbro, dolerite, and basalts and occupy considerable areas called trap regions. Traps consist of clinopyroxene (usually augite), olivine, basic plagioclase, magnetite, apatite, and, less frequently, ortho-pyroxene and biotite. Among the many secondary minerals are iddingsite (which develops by alteration of olivine), palagonite, chlorite, zeolites, prehnite, and actinolite. An ophitic texture is characteristic of traps; a microlitic or glassy texture is less common. Traps are usually gently sloping lava flows, sometimes with a pillow structure, tuff beds, or intrusive veins 10–25 m thick. Dikes, bosses, ring dikes, and necks are also encountered.

Traps are typical of craton regions of the earth’s crust and may occupy considerable areas. They are found, for example, in Eastern Siberia (about 2 million sq km), in the Deccan plateau of India, in South Africa, and in the Paraná plateau of South America. Traps are mostly derivatives of tholeiitic magma (see) and partly of olivine-basalt magma; they apparently originated in the mantle. In the Central Siberian Plateau the traps were formed by the intrusion and extrusion of magma that occurred in several phases over a long period of time, from the Permian to the middle Triassic. The thickness of the traps may reach 2,000 m.

Traps include many kinds of useful minerals. The differentiation of the magma forming the traps led to the development of copper and nickel sulfide deposits (as in the Noril’sk Ore Region), platinum ore deposits (as in South Africa), and iron ore deposits. Deposits of Iceland spar are associated with the products of postmagmatic hydrothermal processes. Deposits of graphite that developed during contact metamorphism of coals under the action of traps are temporally correlated with formation of the trap.

REFERENCES

Godlevskii, M. N. Trappy i rudonosnye intruzii Noril’skogo raiona. Moscow, 1959.
Zolotukhin, V. V. Osnovnye zakonomernosti prototektoniki i vo-prosy formirovaniia rudonosnykh trappovykh intruzii (na primere Noril’ska). Moscow, 1964.

V. P. PETROV

trap

[trap]

(aerospace engineering)

That part of a rocket motor that keeps the propellant grain in place.

(civil engineering)

A bend or dip in a soil drain which is always full of water, providing a water seal to prevent odors from entering the building.

(computer science)

An automatic transfer of control of a computer to a known location, this transfer occurring when a specified condition is detected by hardware.

(electronics)

A tuned circuit used in the radio-frequency or intermediate-frequency section of a receiver to reject undesired frequencies; traps in television receiver video circuits keep the sound signal out of the picture channel. Also known as rejector.

wave trap

(engineering)

A sealed passage such as a U-shaped bend in a pipe or pump that prevents the return flow of liquid or gas.

(geology)

oil trap

(mechanical engineering)

A device which reduces the effect of the vapor pressure of oil or mercury on the high-vacuum side of a diffusion pump.

(petrology)

Any dark-colored, fine-grained, nongranitic, hypabyssal or extrusive rock. Also known as trappide; trap rock.

(solid-state physics)

Any irregularity, such as a vacancy, in a semiconductor at which an electron or hole in the conduction band can be caught and trapped until released by thermal agitation. Also known as semiconductor trap.

trap

1. A device to maintain a water seal against sewer gases, air, and odors; also called a stench trap.

2. A removable section of a theater stage floor.

3. Same as traprock.

trap

(1)

A program interrupt, usually an interrupt caused by some exceptional situation in the user program. In most cases, the OS performs some action, then returns control to the program.

trap

(2)

To cause a trap. "These instructions trap to the monitor." Also used transitively to indicate the cause of the trap. "The monitor traps all input/output instructions."

This term is associated with assembler programming ("interrupt" or "exception" is more common among HLL programmers) and appears to be fading into history among programmers as the role of assembler continues to shrink. However, it is still important to computer architects and systems hackers (see system, sense 1), who use it to distinguish deterministically repeatable exceptions from timing-dependent ones (such as I/O interrupts).

trap

To respond to a particular condition in a running program; for example, to "trap an interrupt" means to wait for a particular interrupt to occur and then redirect the computer to execute an appropriate routine. An "error trap" tests for an invalid set of data. It then displays the correct error message and bypasses processing that data. A "debugging trap" looks for the execution of a particular instruction in order to immediately stop the program and analyze the status of the system at that moment.