Aerial seeding is a technique of sowing seeds by spraying them through aerial mechanical means such as an aircraft. This technique is one of the several broadcast seeding techniques. This technique is usually used to grow grasses, legumes or other suitable soil binding plants. The process is applied to increase vegetative cover over barren lands like ravines or burnt sites, where large geographical area is involved. The purpose of the technique is soil conservation by reducing soil erosion in extremely large area within lesser period. It is typically used where soil erosion hazards are high and native plant seed bank is destroyed by temperature or washed away by water resulting into complete denudation of top soil. This is the most effective technique for geographically inaccessible areas. Seed is dropped from fixed-wing aircraft or helicopter directly on the soil from a reasonable altitude.
Monday, January 26, 2009
Monday, January 19, 2009
Alpaca
The Alpaca (Vicugna pacos) is a domesticated species of South American camelid. It resembles a small llama in superficial appearance.
Alpacas are kept in herds that graze on the level heights of the Andes of Ecuador, southern Peru, northern Bolivia, and northern Chile at an altitude of 3,500 m (11,483 ft) to 5,000 m (16,404 ft) meters above sea-level, throughout the year.[citation needed] Alpacas are considerably smaller than llamas, and unlike llamas, alpacas are not used as beasts of burden but are valued only for their fiber. Alpaca fiber is used for making knitted and woven items, much as sheep's wool is. These items include blankets, sweaters, hats, gloves, scarves, a wide variety of textiles and ponchos in South America, and sweaters, socks, coats and bedding in other parts of the world. The fiber comes in more than 52 natural colors as classified in Peru, 12 as classified in Australia and 16 as classified in the United States. Alpacas and llamas differ in that alpacas have straight ears and llamas have banana-shaped ears. Aside from these differences, llamas are on average 1-2 feet taller and proportionally bigger than alpacas.
In the textile industry, "alpaca" primarily refers to the hair of Peruvian alpacas, but more broadly it refers to a style of fabric originally made from alpaca hair but now often made from similar fibers, such as mohair, Icelandic sheep wool, or even high-quality English wool.[citation needed] In trade, distinctions are made between alpacas and the several styles of mohair and luster.
The Alpaca (Vicugna pacos) is a domesticated species of South American camelid. It resembles a small llama in superficial appearance.
Alpacas are kept in herds that graze on the level heights of the Andes of Ecuador, southern Peru, northern Bolivia, and northern Chile at an altitude of 3,500 m (11,483 ft) to 5,000 m (16,404 ft) meters above sea-level, throughout the year.[citation needed] Alpacas are considerably smaller than llamas, and unlike llamas, alpacas are not used as beasts of burden but are valued only for their fiber. Alpaca fiber is used for making knitted and woven items, much as sheep's wool is. These items include blankets, sweaters, hats, gloves, scarves, a wide variety of textiles and ponchos in South America, and sweaters, socks, coats and bedding in other parts of the world. The fiber comes in more than 52 natural colors as classified in Peru, 12 as classified in Australia and 16 as classified in the United States. Alpacas and llamas differ in that alpacas have straight ears and llamas have banana-shaped ears. Aside from these differences, llamas are on average 1-2 feet taller and proportionally bigger than alpacas.
In the textile industry, "alpaca" primarily refers to the hair of Peruvian alpacas, but more broadly it refers to a style of fabric originally made from alpaca hair but now often made from similar fibers, such as mohair, Icelandic sheep wool, or even high-quality English wool.[citation needed] In trade, distinctions are made between alpacas and the several styles of mohair and luster.
Monday, January 12, 2009
Wednesday, January 07, 2009
Ramie
Ramie (Boehmeria nivea) is a flowering plant in the nettle family Urticaceae, native to eastern Asia. It is a herbaceous perennial growing to 1 - 2.5 m tall; the leaves are heart-shaped, 7-15 cm long and 6-12 cm broad, and white on the underside with dense small hairs - this gives it a silvery appearance; unlike nettles, the hairs do not sting. The true ramie or China Grass also called Chinese plant or white ramie is the Chinese cultivated plant. A second type, is known as green ramie or rhea and is believed to have originated in the Malay Peninsula. This type has smaller leaves which are green on the underside, and it appears to be better suited to tropical conditions.
Thursday, January 01, 2009
Popigai crater
The Popigai crater in Siberia, Russia is tied with Manicouagan Reservoir as the 4th largest verified impact crater on Earth. A large bolide impact created the 100-kilometer diameter crater 35.7 ± 0.2 (2σ) million years ago during the late Eocene (Priabonian stage). The crater is just north of the Siberian city Norilsk, or 1 1/2 hours (by helicopter) from the outpost of Khatanga. It is designated by UNESCO as a Geopark, a site of special geological heritage.
For decades the Popigai crater has fascinated paleontologists and geologists, but the entire area was completely off limits because of the diamonds and the mines constructed by gulag prisoners under Stalin; however, a major investigatory expedition was undertaken in 1997 (IPEX 1997) which greatly advanced understanding of the enigmatic structure. The impactor in this event has been identified as either an eight-kilometer diameter chondrite asteroid, or a five-kilometer diameter stony asteroid.
The shock pressures from the impact instantaneously transformed graphite in the ground into diamonds within a 13.6 kilometer radius of the impact point. Diamonds are usually 0.5 to 2 millimeters in diameter; a few exceptional specimens are 10 millimeters in size. The diamonds not only inherit the tabular shape of the original graphite grains but they additionally preserve the original crystal's delicate striations.
Popigai is the best example yet of the formation of a crater of this type. Three other craters are larger, but they are either buried (Chicxulub), strongly deformed (Sudbury), or deformed and severely eroded (Vredefort).
There is a small possibility that Popigai impact crater formed simultaneous with the c. 35 million year old Chesapeake Bay and Toms Canyon impact craters.
For decades the Popigai crater has fascinated paleontologists and geologists, but the entire area was completely off limits because of the diamonds and the mines constructed by gulag prisoners under Stalin; however, a major investigatory expedition was undertaken in 1997 (IPEX 1997) which greatly advanced understanding of the enigmatic structure. The impactor in this event has been identified as either an eight-kilometer diameter chondrite asteroid, or a five-kilometer diameter stony asteroid.
The shock pressures from the impact instantaneously transformed graphite in the ground into diamonds within a 13.6 kilometer radius of the impact point. Diamonds are usually 0.5 to 2 millimeters in diameter; a few exceptional specimens are 10 millimeters in size. The diamonds not only inherit the tabular shape of the original graphite grains but they additionally preserve the original crystal's delicate striations.
Popigai is the best example yet of the formation of a crater of this type. Three other craters are larger, but they are either buried (Chicxulub), strongly deformed (Sudbury), or deformed and severely eroded (Vredefort).
There is a small possibility that Popigai impact crater formed simultaneous with the c. 35 million year old Chesapeake Bay and Toms Canyon impact craters.
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