gall(redirected from Plant galls)
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gall,abnormal growth, or hypertrophy, of plant tissue produced by chemical or mechanical (e.g., the rubbing together of two branches) irritants or hormones. Chemical irritants are released by parasitic fungi, bacteria, nematode worms, gall insects, and mites. Crown gall, which attacks peach and other fruit trees, grapes, and roses, is caused by bacteria. Despite its name (the crown is the head of foliage), the tumorous growths usually occur on the stem below ground level. The gall insects (e.g., certain aphids, wasps, moths, beetles, and midges) deposit their eggs in the plant tissues, which begin to swell as the larvae hatch. Sometimes the larvae feed on the gall and pupate within it. The irritant is released by the female at the time of oviposition or by the developing larva itself. Each species of gall insect has its favorite host and forms galls of a characteristic shape; some are large and woody and others may be soft, knobby, or spiny. They may be formed on any part of a plant but generally occur in areas where cells are actively growing. In the United States, Galls are commonly seen on oak and willow trees and on rose bushes, goldenrod, and witch hazel. The Hessian fly, the wheat midge, and the mites and midges that attack fruit trees are the most damaging economically of the gall insects. Galls are rich in resins and tannic acid and have been used in the manufacture of permanent inks and astringent ointments, in dyeing, and in tanning. A high-quality ink has long been made from the Aleppo gall, found on oaks in the Middle East; it is one of a number of galls resembling nuts and called gallnuts or nutgalls.
Gall(gôl), c.1840–1894, war chief of the Sioux, b. South Dakota. He refused to accept the treaty of 1868 (by which he would have been confined to a reservation), joined Sitting BullSitting Bull,
c.1831–1890, Native American chief and spiritual leader, Sioux leader in the battle of the Little Bighorn. He rose to prominence in the Sioux warfare against the whites and the resistance of the Native Americans under his leadership to forced settlement on a
..... Click the link for more information. and other dissident chiefs, and was the chief military lieutenant of Sitting Bull in the great defeat of George Armstrong Custer in the battle of Little Bighorn in 1876. He retreated to Canada but, after a quarrel with Sitting Bull about returning to their former lands, returned and surrendered at Poplar, Mont. He became a farmer on the reservation and with his friend James McLaughlin, the Indian agent, did much to improve relations between Native Americans and whites.
See T. B. Marquis, Sitting Bull and Gall (1934).
A sore on the skin that is caused by chafing.
Damage to metal surfaces resulting from friction and improper lubrication.
A large swelling on plant tissues caused by the invasion of parasites, such as fungi or bacteria, following puncture by an insect; insect oviposit and larvae of insects are found in galls.
Unusual growth of plant tissues; a result of the introduction of a foreign substance such as a chemical or fungus, or a result of mechanical injury.
compressor blade damage
i. Bend. The blade gives the appearance of ragged edges. Smooth repair of the edges or surface in question can be carried out, but the extent of the damage that can be repaired is limited.
ii. Bow. The main source of this type of damage is a foreign object. The blade is bent at the tips and the edges.
iii. Burning. The damage is caused by overheating. The surface of the blade is discolored. If the overheating is severe, there may be some flow of material as well.
iv. Burr. A ragged or turn-out edge is indicative of this type of damage. This takes place during the grinding or cutting operation of the blade at the manufacturing stage.
v. Corrosion. Oxidants and corrosive agents, especially moisture present in the atmosphere, are the main reasons for the corrosion or pitting of the blades. Normally, regular washing is sufficient to prevent it. The blade gives a pitted appearance, and there is some breakdown of the surface of the blade. Also called pitting.
vi. Cracks. Excessive stress from shocks, overloading, or faulty processing of blades during manufacturing can cause cracks and result in their fracture.
vii. Dent. These can be caused by FOD (foreign-object damage) or strikes by dull objects like those in bird strikes. Minor dents can be repaired.
viii. Gall. This type of damage is from the severe rubbing of blades, in which a transfer of metal from one surface to another takes place.
ix. Gouging. The blade gives the appearance of displacing material from its surface, and a tearing effect is prominently visible. This type of damage is from the presence of a comparatively large cutting material or foreign body between moving parts.
x. Growth. The damage manifests itself in the form of elongation of the blades. Growth type of damage takes place because of continued and/or excessive heat and centrifugal force.
xi. Score. Deep scratches are indicative of scoring, which is caused by the presence of chips between surfaces.
xii. Scratch. Narrow and shallow scratches are caused by sand or fine foreign particles as well as by mishandling the blades.
xiii. Pitting. Pitting takes place because of atmospheric corrosion, especially seawater. The surface of the blade shows signs of pitting.
sponge soaked with it given to crucified Jesus. [N.T.: Matthew 26:48]
See: Passion of Christ
a sore on the skin caused by chafing