Friday, December 21, 2007

Tsunami

A tsunami is a series of waves shaped when a body of water, such as an ocean, is rapidly displaced. Earthquakes, group movements above or below water, volcanic eruptions and other underwater explosions, landslides, large meteorite impacts and testing with nuclear weapons at sea all have the potential to produce a tsunami. The effects of a tsunami can range from imperceptible to devastating. The word tsunami comes from the Japanese words meaning harbor and wave. For the plural, one can either follow usual English practice and add an s, or use an invariable plural as in Japanese. The term was created by fishermen who returned to port to find the area neighboring their harbor devastated, although they had not been conscious of any wave in the open water. Tsunamis are general throughout Japanese history; approximately 195 events in Japan have been recorded.

A tsunami has a much smaller amplitude (wave height) offshore, and a very long wavelength, which is why they generally pass unobserved at sea, forming only a passing bulge in the ocean. Tsunami have been historically referred to as tidal waves because as they approach land, they take on the characteristics of a vicious onrushing tide rather than the sort of cresting waves that are formed by wind action upon the ocean. Since they are not really related to tides the term is considered misleading and its treatment is discouraged by oceanographers.

Monday, December 17, 2007

Resistance

Electrical resistance is a compute of the degree to which an object opposes an electric current through it. The SI unit of electrical resistance is the ohm. Its reciprocal quantity is electrical conductance calculated in siemens. Electrical resistance shares some conceptual parallels with the mechanical notion of friction.

The resistance of an object determines the amount of current through the object for a known voltage across the object I=V/R, where R is the resistance of the object, measured in ohms, equivalent to J•s/C2, V is the voltage across the object, measured in volts, I is the current through the object, measured in amperes. In metals, the Fermi level lies in the conduction band giving rise to free transfer electrons. However, in semiconductors the position of the fermi level is within the band gap, closely half way between the conduction band minimum and valence band maximum for intrinsic semiconductors.

Thursday, November 29, 2007

space shuttle

NASA's Space Shuttle, officially called Space Transportation System (STS), is the United States government's present manned launch vehicle. At launch, it consists of a rust-colored outer tank, two white, slender solid rocket boosters (SRBs), and a winged orbiter. The orbiter carries astronauts and payload such as satellites or space location parts into low earth orbit. Normally, five to seven astronauts ride in the orbiter, with two pilots, eight have been carried, and eleven could be accommodated in an urgent situation landing.
When the orbiter's work is complete, it fires its orbital maneuvering thrusters to drop out of orbit and re-enters the Earth's atmosphere. During the descent and landing, the shuttle orbiter acts as a glider and makes a completely unpowered landing. Five spaceworthy orbiters were build, of which three remain.

The Shuttle is the first orbital spacecraft considered for partial reusability. It carries large payloads to various orbits, provides crew rotary motion for the International Space Station (ISS), and performs servicing missions. The orbiter can also recover satellites and other payloads from orbit and return them to Earth, but this capability has not been used often. However, it has been used to return large payloads from the ISS to Earth, as the Russian Soyuz spacecraft has limited capacity for return payloads. Each Shuttle was designed for a expected lifespan of 100 launches or 10 years' operational life.

Thursday, November 22, 2007

Entertainment

Entertainment is an occasion, piece, or movement designed to give enjoyment or leisure to an audience. The audience may join in the entertainment passively as in actively as in computer games. The playing of sports and reading of journalism are usually included in entertainment, but these are regularly called activity more specifically, because they involve some energetic participation past mere leisure.

While people have laughing themselves since the beginning of time, the entertainment industry first became a leading force in culture in the 20th century with the development of latest electronic technologies of recording and spreading. Western peoples, tired of serious purposes and gathering massacre, turned to popular culture following the two world wars. The financial basis of this new culture was advertising of free or inexpensive entertainment program. In their peak, television networks were great selling machines which, besides entertaining people, prohibited both commercial and political markets by providing direct access to the group of customers. This "territory" is now in danger by the explosion and segmentation of media and especially by the growing importance of communication by computer which allows the consumer to look for out the informational message as an alternative of having it broadcast to him or her. A new system of world history sees Americans in changeover between a fourth, entertainment-based "society" and a future fifth evolution based on computer communication.

Tuesday, October 30, 2007

Blue tooth

Blue tooth is an industrial requirement for wireless personal area networks.Blue tooth provides a way to connect and swap information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally unlicensed short-range radio frequency. The Blue tooth specifications are licensed and developed by the Blue tooth Special Interest Group.

Blue tooth is a radio standard and communications protocol mostly designed for low power consumption, with a short range based on low-cost transceiver microchips in each device. The devices use a radio communications system, so they do not have to be in line of view of each other, and can even be in other rooms, as long as the conservative transmission is powerful enough.

Monday, October 22, 2007

Hockey

Hockey is any of a family of sports in which two teams struggle by trying to maneuver a ball, or a hard, surrounding disc called a puck, into the opponent's net or goal, using a hockey stick. Field hockey is played on nettle, natural grass, sand-based or water-based artificial turfs, with a small, hard ball. The game is popular among both males and females in many countries of the world, mostly in Europe, India, Pakistan, Australia, New Zealand, South Africa and South Asia. In most countries, the game is played between single-sex sides, even though it can be played by mixed-sex sides. In the United States and Canada it is played mostly by women. Ball hockey is played in a gym using sticks and a ball, often a tennis ball with the hair removed.

There are early representations and reports of hockey-type games being played on ice in the Netherlands, and reports from Canada from the beginning of the nineteenth century, but the modern game was initially planned by students at McGill University, Montreal in 1875 who, by two years later, codified the first set of ice hockey rules and organized the first teams.

Friday, October 12, 2007

Race

The term race describes populations or groups of people well-known by different sets of characteristics, and beliefs about common ancestry. The most broadly used human racial categories are based on visible traits, and self-identification. Conceptions of race, as well as specific ways of grouping races, vary by culture and over time, and are often contentious for scientific as well as social and political reasons. Many scientists contend that while the features on which a racial categorization are made may be based on genetic factors, the idea of race itself, and actual divisions of persons into groups based on selected hereditary features, are social constructs.
Since the 1940s, some evolutionary scientists have rejected the view of race as a biologically meaningful impression. A majority of evolutionary scientists reject the notion that any definition of race pertaining to humans can have any taxonomic rigour and validity. Mainstream scientists have argued that race definition are imprecise, arbitrary, derived from custom, have many exceptions, have many gradations, and that the numbers of races experimental vary according to the culture examined. They further preserve that race as such is best understood as a social construct.

Monday, September 24, 2007

Security

Security is the condition of being sheltered against danger or loss. In the general sense, security is a perception similar to safety. The nuance between the two is an added emphasis on being protected from dangers that initiate from outside. Individuals or actions that encroach upon the condition of protection are responsible for the breach of security.
The word security in general procedure is synonymous with safety, but as a technical term security means that something not only is protected but that it has been secured. A condition that results from the establishment and maintenance of protective measures that ensures a state of inviolability from hostile acts or influences. With respect to classified matter, the condition that prevents unauthorized persons from having right to use to official information that is safeguarded in the benefit of national security.

Thursday, September 13, 2007

Planet

A planet, as defined by the International Astronomical Union (IAU), is a celestial body orbiting a star or stellar remains that is massive enough to be rounded by its own gravity, not massive enough to cause thermonuclear fusion in its core, and has cleared its neighboring region of planetesimals. The term planet changed from something that stimulated across the sky, to a body that orbited the Earth. When the heliocentric model gained sway in the 16th century, it became established that a planet was actually something that directly orbited the Sun. At the end of the 17th century, when the first satellites of Saturn were exposed, the terms planet and satellite were at first used interchangeably, although satellite would gradually become more common in the following century.

The energetic impacts of the smaller planetesimals will heat up the increasing planet, causing it to at least partially melt. The interior of the planet begins to differentiate by mass, mounting a denser core. Smaller terrestrial planets lose most of their atmospheres because of this accretion, but the lost gases can be replaced by out gassing from the mantle and from the succeeding impact of comets.

Friday, August 31, 2007

Earthquake

An earthquake is the result of a sudden release of stored energy in the Earth's outer layer that creates seismic waves. Earthquakes are accordingly measured with a seismometer, generally known as a seismograph. The magnitude of an earthquake is conventionally reported using the Richter scale or a related instant scale. At the Earth's surface, earthquakes may manifest themselves by a trembling or displacement of the ground. Sometimes, they cause tsunamis, which may lead to loss of life and annihilation of property. An earthquake is caused by tectonic plates getting stuck and putting a damage on the ground. The strain becomes so great that rocks give way by breaking and downhill along fault planes. Earthquakes may occur naturally or as a result of human actions. Slighter earthquakes can also be caused by volcanic activity, landslides, mine blasts, and nuclear tests. In its most generic intelligence, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic effect.

Monday, August 20, 2007

Cloud

A cloud is a visible mass of condensed droplets, frozen crystals suspended in the atmosphere above the surface of the Earth or another earthly body, such as a moon. The branch of meteorology in which exhaust are studied is nephology.
On Earth the condensing matter is typically water vapor, which forms small droplets or ice crystals, typically 0.01 mm in diameter. When surrounded by billions of other droplets or crystals they become observable as clouds. Dense deep clouds exhibit a high reflectance throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light professionally, so that the intensity of the solar radiation decreases with depth into the cloud, hence the gray or even sometimes dark exterior of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as through sunrise or sunset, may be colored accordingly. In the near-infrared range, clouds would appear darker because the water that constitutes the cloud droplets muscularly absorbs solar radiation at those wavelengths.

Friday, August 10, 2007

Inca Rope bridge

Inca Rope bridges were simple suspension bridges over canyons and gorges to present access for the Inca Empire. Bridges of this type were suitable for use since the Inca people did not use wheeled transport - traffic was incomplete to pedestrians and livestock. These bridges were an intrinsic part on the Inca road scheme and are an excellent example of Inca innovation in engineering. They were frequently used by Chasqui runners delivering messages throughout the Inca Empire.
The construction of these bridges amounted to a pair of stone anchors on each side of the canyon with immense cables of woven ichu grass linking these two pylons together. Adding to this construction, two additional cables acted as guardrails. The cables which supported the foot-path were unbreakable with plaited branches. This multi-structure system made these bridges strong enough to even carry the Spaniards while riding horses after they indoors. However, these massive bridges were so heavy that they tended to sag in the middle, and this caused them to bend in high winds.

Tuesday, July 31, 2007

Calculator

A calculator is a machine for performing calculations. Although modern calculators often incorporate a general purpose computer, the device is calculated for performing specific operations, rather than for flexibility. Modern calculators are more convenient than most computers, though some PDAs are comparable in amount to handheld calculators.

In the past, some calculators were as huge as today's computers. The first automatic calculators were mechanical desktop devices which were replaced by electromechanical desktop calculators, and then by electronic devices using first thermionic valves, then transistors, then hard-wired integrated circuit logic. New calculators are electrically powered and come in innumerable shapes and sizes varying from cheap, give-away, credit-card sized models to more sturdy adding machine-like models with built-in printers.

Tuesday, July 24, 2007

Indicator

Dial indicators are instruments used to correctly measure a small distance. They may also be known as a Dial gauge, Dial Test Indicator, or as a clock. They are named so because the measurement results are displayed in a overstated way by means of a dial. They may be used to check the dissimilarity in tolerance during the check process of a machined part, measure the deflection of a beam or ring under laboratory conditions, as well as many other situations where a small measurement needs to be registered or indicated.

An economic indicator is a statistic concerning the economy. The lighting system of a motor vehicle consists of lighting and signaling procedure mounted or integrated to the front, sides and rear of the vehicle. The purpose of this system is to present illumination for the driver to operate the vehicle safely after dark, to increase the visibility of the vehicle, and to display information about the vehicle's presence, position, size, direction of travel, and driver's intentions concerning direction and speed of travel.

Wednesday, July 18, 2007

Reliability

In computer networking, a reliable protocol is one that ensures that reliability properties with respect to the delivery of data to the intended recipient(s), as opposed to an unreliable procedure, which does not guarantee that data will be delivered intact, or that it will be delivered at all. A reliable multicast protocol may ensure consistency on a per-recipient basis, as well as provide strong reliability properties that relate the delivery of data to different recipients, such as e.g. total order, atomicity, or virtual synchrony.

Reliable protocols normally incur more overhead than unreliable protocols, and as a result, are slower and less scalable. This often isn't an issue for unicast protocols, but it may be a difficulty for multicast protocols. TCP, the main protocol used in the Internet today, is a reliable unicast protocol. UDP, often used in computer games or other situation where speed is an issue and the loss of a little fact is not, is an unreliable unicast protocol.

Thursday, July 12, 2007

Table

In relational databases, SQL databases, and flat file databases, a table is a set of data elements that is controlled using a model of horizontal rows and vertical columns. The columns are identified by name, and the rows are identified by the values appearing in a particular column division which has been identified as a candidate key. Table is another term for family although there is the difference in that a table is usually a multi-set of rows whereas a relation is a set and does not allow duplicates. A table has a particular number of columns but can have any number of rows. Besides the actual data rows, tables generally have related with them some meta-information, such as constraints on the table or on the values within particular columns.

The data in a table does not have to be actually stored in the database. Views are also relational tables, but their data is considered at query time. In non-relational systems, such as hierarchical databases, the isolated counterpart of a table is a structured file, representing the rows of a table in each record of the file and each column in a record.

Thursday, July 05, 2007

Trams

Electric-powered trams were first successfully experienced in service in Richmond, Virginia, in 1888, in the Richmond Union Passenger Railway built by Frank J. Sprague. There were earlier saleable installations of electric streetcars, including one in Berlin, as early as 1881 by Werner von Siemens and the company that still bears his name, and also one in Saint Petersburg, Russia, made-up and tested by Fyodor Pirotsky in 1880. Another was by John Joseph Wright, brother of the celebrated mining entrepreneur Whitaker Wright, in Toronto in 1883.The earlier installations, however, proved difficult and/or variable. Siemens' line, for example, provided power through a live rail and a return rail, like a model train setup, limiting the voltage that could be used, and providing unwanted stimulation to people and animals crossing the tracks. Siemens later planned his own method of current collection, this time from an overhead wire, called the bow collector. Once this had been developed his cars became equal to, if not superior than, any of Sprague's cars. The first electric interurban line connecting St. Catherine’s and Thorold, Ontario was operated in 1887, and was measured quite successful at the time. While this line proved quite versatile as one of the earliest fully functional electric streetcar installations, it still required horse-drawn carry while hiking the Niagara Escarpment and for two months of the winter when hydroelectricity was not available. This line continuous service in its original form well into the 1950s.

Wednesday, June 27, 2007

Health

Health is the level of functional and metabolic effectiveness of an organism at both the micro and macro level. In the medical field, health is commonly defined as an organism's skill to efficiently respond to challenges and effectively restore and maintain a state of balance, known as homeostasis.

Another widely established definition of health is that of the World Health Organization which states that health is a state of complete physical, mental and social well-being and not merely the nonattendance of disease or infirmity .In more recent years, this statement has been customized to include the ability to lead a socially and economically productive life. The definition is not without criticism, as some argue that health cannot be defined as a state at all, but must be seen as a process of incessant adjustment to the changing demands of living and of the changing meaning we give to life.

Wednesday, June 20, 2007

Color

Color is the visual perceptual possessions corresponding in humans to the categories called red, yellow, white, etc. Color derives from spectrum of light distribution of light energy versus wavelength interacting in the eye with the spectral sensitivities of the light receptors. Color categories and physical condition of color are also associated with objects, materials, light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra.

Typically, only features of the composition of light that are visible by humans wavelength spectrum from 400 nm to 700 nm, roughly are included, thereby objectively relating the psychological phenomenon of color to its physical specification. Because perception of color stems from the varying sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantify by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully clarify the psychophysical perception of color appearance.

The science of color is sometimes called chromatics. It includes the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic emission in the visible range that is, what we commonly refer to simply as light.

Thursday, June 07, 2007

Cosmetics

Cosmetics or make-up are substances used to enhance the beauty of the human body. Cosmetics include lotions, powders, lipstick and many other types of products. Their use is widespread, especially among women in Western countries. The manufacture of cosmetics is currently dominated by a small number of multinational corporations that originated in the early 20th century, but the distribution and sale of cosmetics is spread among a wide range of different businesses.

Tuesday, May 01, 2007

Flag

A flag is a piece of woven cloth, often flown from a pole or mast, generally used symbolically for signalling or identification. The term flag is also used to refer to the graphic design employed by a flag, or to its depiction in another medium.
The first flags were used to assist military coordination on battlefields and flags have evolved into a general tool for rudimentary signalling and identification, especially in environments where communication is similarly challenging (such as the maritime environment where semaphore is used). National flags are potent patriotic symbols with varied wide-ranging interpretations, often including strong military associations due to their original and ongoing military uses. Flags are used in messaging, advertising, or for other decorative purposes, though at this less formal end the distinction between a flag and a simple cloth banner is blurred. The study of flags is known as vexillology, from the Latin vexillum meaning flag or banner.

Monday, April 30, 2007

Tax

A tax is a financial charge or other levy imposed on an individual or a legal entity by a state or a functional equivalent of a state (for example, tribes, secessionist movements or revolutionary movements). Taxes could also be imposed by a subnational entity. Taxes consist of direct tax or indirect tax, and may be paid in money or as corvée labor. A tax may be defined as a "pecuniary burden laid upon individuals or property to support the government [ . . .] a payment exacted by legislative authority."[1] A tax "is not a voluntary payment or donation, but an enforced contribution, exacted pursuant to legislative authority" and is "any contribution imposed by government [ . . .] whether under the name of toll, tribute, tallage, gabel, impost, duty, custom, excise, subsidy, aid, supply, or other name."[2]
In modern capitalist taxation systems, taxes are levied in money, but in-kind and corvée taxation are characteristic of traditional or pre-capitalist states and their functional equivalents. The method of taxation and the government expenditure of taxes raised is often highly debated in politics and economics. Tax collection is performed by a government agency such as Revenue Canada, the Internal Revenue Service (IRS) in the United States, or Her Majesty's Revenue and Customs (HMRC) in the UK. When taxes are not fully paid, civil penalties (such as fines or forfeiture) or criminal penalties (such as incarceration)[3] may be imposed on the non-paying entity or individual.

Deerhabitat

Deer are widely distributed, and hunted, with indigenous representatives in all continents except Antarctica and Australia. Deer live in a variety of biomes ranging from tundra to the tropical rainforest. While often associated with forests, many deer are ecotone species that live in transitional areas between forests and thickets (for cover) and prairie and savanna (open space). The majority of large deer species inhabit temperate mixed deciduous forest, mountain mixed coniferous forest, tropical seasonal/dry forest, and savanna habitats around the world. Clearing open areas within forests to some extent may actually benefit deer populations by exposing the understory and allowing the types of grasses, weeds, and herbs to grow that deer like to eat. However, adequate forest or brush cover must still be provided for populations to grow and thrive. Small species such as the brocket deer and pudus of Central and South America, and the muntjacs of Asia do occupy dense forests and are less often seen in open spaces. There are also several species of deer that are highly specialized and live almost exclusively in mountains, grasslands, swamps and "wet" savannas, riparian corridors surrounded by deserts. Some deer have a circumpolar distribution in both North America and Eurasia. Examples include the reindeer (caribou) that live in Arctic tundra and taiga (boreal forests) and moose that inhabit taiga and adjacent areas.

Monday, April 02, 2007

Debenture

In finance, a debenture is a long-term debt instrument used by governments and large companies to obtain funds. It is similar to a bond except the securitization conditions are different. A debenture is usually unsecured in the sense that there are no liens or pledges on specific assets. It is however, secured by all properties not or else pledged. In the case of bankruptcy debenture holders are considered general creditors.

The benefit of debentures to the issuer is they leave specific assets tangential, and thereby leave them open for subsequent financing.

Monday, February 05, 2007

Foreclosure

Foreclosure is the legal proceeding in which bank or other secured creditor sells or reclaims a part of real property due to the owner's failure to comply with the agreement between the lender and borrower called a "mortgage" or "deed of trust". Usually, the abuse of the mortgage is a default in payment of a promissory note, secured by a lien on the property. When the transaction is complete, it is normally said that the lender has foreclosed its mortgage or lien.

In US, there are two kinds of foreclosure in common law states. Using a deed in lieu of foreclosure, the bank claims the title and possession of the property back in full satisfaction of a debt, usually on contract. Many states needs the latter sort of proceeding in some or all cases of foreclosure, in order to protect any equity the debtor may have in the property, in case the value of the debt being foreclosed on is significantly less than the market value of the immovable assets.

Saturday, January 13, 2007

Political divisions of China

The People's Republic of China has administrative control over twenty-two provinces; the government of the PRC considers Taiwan to be its twenty-third region. Apart from provinces, there are five independent regions, each with a designated minority group; four municipalities; and two Special Administrative Regions that enjoy considerable autonomy.

The twenty-two provinces, five autonomous regions and four municipalities can be jointly referred to as "mainland China", a term which usually excludes Hong Kong and Macau.