Sunday, July 29, 2007

Mobile phone

The introduction of cells for mobile phone base stations, invented in 1947 by Bell Labs engineers at AT&T, was further industrialized by Bell Labs during the 1960s. Due to their low establishment expenses and fast exploitation, mobile phone networks have since spread hastily throughout the world, outstripping the growth of fixed telephony.

The zero generation (0G) of mobile telephones was introduced in 1945. 0G mobile telephones, such as Mobile Telephone Service, were not officially categorized as mobile phones, since they did not sustain the automatic change of channel frequency during calls, which allows the user to shift from one cell (the base station coverage area) to another cell, an attribute called "handover".

The first marketable cellular network was launched in Japan by NTT in 1979. Fully automatic cellular networks were first introduced in the beginning to mid 1980s (the 1G generation) with the Nordic Mobile Telephone (NMT) system in 1981. This was followed by an explosion in mobile telephone habit, particularly in Northern Europe.

The first "modern" network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard which also striking the beginning of competition in mobile telecoms when Radiolinja challenged current Telecom Finland (now part of TeliaSonera) who ran a 1G NMT network. A decade after, the first commercial commence of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard. However, Martin Cooper, a Motorola engineer, is accredited with the innovation of the modern mobile phone in the 1990s. Until the early 1990s, most mobile phones were too large to be carried in a jacket pocket, so they were normally installed in vehicles as car phones. With the miniaturization of digital apparatus, mobile phones have become more and handier over the years.

Sunday, July 22, 2007

Fertilisation

Fertilisation or fertilization also known as conception, fecundation and syngamy, is fusion of gametes to form a new organism of the same variety. In animals, the process involves a sperm fuse with an ovum, which finally leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in interior fertilisation, or outside in the case of external fertilisation.

The entire process of development of new persons is called procreation, the act of species reproduction.

Sunday, July 15, 2007

Nonfood uses

Because fruits have been such a major part of the human diet, different cultures have urbanized many different uses for various fruits that they do not depend on as being edible. Many dry fruits are used as streamer or in dried flower arrangements, such as unicorn plant, lotus, wheat, annual honesty and milkweed. Ornamental trees and shrubs are frequently refined for their colorful fruits, as well as holly, pyracantha, viburnum, skimmia, beautyberry and cotoneaster.

Fruits of opium poppy are the basis of the drugs opium and morphine. Osage orange fruits are used to keep away cockroaches. Bayberry fruits provide a wax frequently used to make candles. Many fruits give natural dyes, e.g. walnut, sumac, cherry and mulberry. Dried up gourds are used as streamer, water jugs, bird houses, musical instruments, cups and dishes. Pumpkins are imprinted into Jack-o'-lanterns for Halloween. The spiny fruit of burdock or cocklebur were the motivation for the invention of Velcro.

Coir is a fiber from the fruit of coconut that is used for doormats, brushes, mattresses, floortiles, sacking, lagging and as a growing medium for container plants. The shell of the coconut fruit is used to make memento heads, cups, bowls, musical instruments and bird houses.

Tuesday, July 10, 2007

Waka

In the Maori language, waka are Maori watercraft, usually canoes. Similar craft are encounter in Polynesia, with connected names such as vaka. Waka range is from small, lightweight canoes, such as waka tiwai used for fishing individuals, during very large waka taua, manned by up to eighty paddlers and up to fourty mtrs in length, large double-hulled canoes for oceanic voyaging.

Many waka are single-hulled vessels locate from hollowed tree trunks. Small waka consist of an only piece as large waka typically consist of some pieces jointed and lashed together. Some waka, mainly in the Chatham Islands, were not usual canoes but were constructed from raupo stalks. Ocean waka, Paddled could be in any size, but were usually propelled by sail. Waka taua are paddled to put across their mana.

Small efficient waka are commonly plain and simple. Superior canoes waka taua in testing are extremely carved. Waka taua are no longer used in fighting but frequently for official purposes.