Hoover Dam
Hoover Dam by Ansel Adams, 1942
Official name	Hoover Dam
Locale	Clark County, Nevada /Mohave County, Arizona,USA
Construction began	1931
Opening date	1936
Construction cost	$49 million
Owner(s)	United States Government
Dam and spillways
Type of dam	Concrete gravity-arch
Height	726.4 ft (221.4 m)
Length	1,244 ft (379 m)
Crest width	45 ft (14 m)
Base width	660 ft (200 m)
Volume	3,250,000 cu yd (2,480,000 m3)
Impounds	Colorado River
Type of spillway	2 x controlled drum-gate
Spillway capacity	400,000 cu ft/s (11,000 m3/s)
Reservoir
Creates	Lake Mead
Capacity	35.2 km3 (28,500,000 acre·ft)
Catchment area	167,800 sq mi (435,000 km2)
Surface area	247 sq mi (640 km2)[1]
Max. water depth	590 ft (180 m)

Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936 during the Great Depression, and was dedicated on September 30, 1935, by President Franklin Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives.

Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and producehydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium called Six Companies, Inc., which began construction on the dam in early 1931. Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and the lack of facilities near the site also presented difficulties. Nevertheless, Six Companies turned over the dam to the federal government on March 1, 1936, more than two years ahead of schedule.

Hoover Dam impounds Lake Mead, and is located near Boulder City, Nevada, a municipality originally constructed for workers on the construction project, about 25 mi (40 km) southeast of Las Vegas, Nevada. The dam's generators provide power for public and private utilities in Nevada, Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year. Heavily travelled U.S. 93 ran along the dam's crest until October 2010, when the Hoover Dam Bypass opened.

telephone(old)

"Phone" redirects here. For other uses, see Phone (disambiguation). This article is about the communications device. For other uses, see Telephone (disambiguation).

Phone
An Olivetti rotary dial telephone, c.1940s

• The telephone (from the Greek: τῆλε, tēle, "far" and φωνή, phōnē, "voice"), often colloquially referred to as a phone, is a telecommunications device that transmits and receives sound, most commonly the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other. It is one of the most common appliances in the developed world, and has long been considered indispensable to businesses, households and governments. The word "telephone" has been adapted to many languages and is widely recognized around the world.
• All telephones have a microphone to speak into, an earphone which reproduces the voice of the other person, a ringer which makes a sound to alert the owner when a call is coming in, and a keypad (or in older phones a telephone dial or no manual device) to enter the telephone number of the telephone being called. The microphone and earphone are usually built into ahandset which is held up to the face to talk. The keypad may be part of the handset or of a base unit to which the handset would be connected. A landline telephone is connected by a pair of wires to the telephone network, while a mobile phone or cell phone is portable and communicates with the telephone network by radio. A cordless telephone has a portable handset which communicates by radio with a base station connected by wire to the telephone network, and can only be used within a limited range of the base station.

• The microphone converts the sound waves to electrical signals, which are sent through the telephone network to the other phone, where they are converted back to sound waves by theearphone in the other phone's handset. Telephones are a duplex communications medium, meaning they allow the people on both ends to talk simultaneously. The telephone network, consisting of a worldwide net of telephone lines, fiberoptic cables, microwave transmission, cellular networks, communications satellites, and undersea telephone cables connected byswitching centers, allows any telephone in the world to communicate with any other. Each telephone line has an identifying number called its telephone number. To initiate a telephone call, a conversation with another telephone, the user enters the other telephone's number into a numeric keypad on his/her phone. Graphic symbols used to designate telephone service or phone-related information in print, signage, and other media include ℡(U+2121), ☎(U+260E), ☏(U+260F), and ✆(U+2706).

Although originally designed for voice communication, the system has been adapted for data communication such as Telex, Fax and dial-up Internet communication.

playstation 3 (PS3)

"PS3" redirects here. For other uses, see PS3 (disambiguation).

PlayStation 3

Counter-clockwise from the top: Original logo, new logo, original "fat" model, Sixaxis controller, DualShock 3controller, current "slim" model.
Developer	SCEI
Manufacturer	Sony EMCS, Foxconn, ASUSTeK[1]
Product family	PlayStation
Type	Video game console
Generation	Seventh generation era
Retail availability	November 11, 2006 (details)
Units sold	41.6 million (as of September 30, 2010)[2]
Media	Blu-ray Disc (PlayStation 3 game disc) DVD Compact Disc PlayStation game disc PlayStation 2 game disc (1st & 2nd generations only) Super Audio CD (1st & 2nd generations only) Digital distribution
Operating system	XrossMediaBar System software version 3.55[3]
CPU	3.2 GHz Cell Broadband Enginewith 1 PPE & 7 SPEs
Storage capacity	2.5" SATA hard drive (20 GB, 40 GB, 60 GB, 80 GB, 120 GB, 160 GB, 250 GB, or 320 GB included)(upgradeable)
Memory	256 MB system and 256 MB video
Display	Video output formats[show]
Graphics	550 MHz NVIDIA/SCEI RSX 'Reality Synthesizer'
Sound	Audio output formats[show]
Controller input	Sixaxis, DualShock 3, Logitech Driving Force GT, Logitech Cordless Precision™ controller, standard USB controllers, GT Force, Rhythm game controllers,PlayStation Move, GunCon 3,PlayStation Portable, Keyboard and Mouse
Connectivity	(details)[show]
Online services	PlayStation Network
Backward compatibility	PlayStation (all models) PlayStation 2 (20 GB, 60 GB and some (CECHExx) 80 GB models)
Predecessor	PlayStation 2

• The PlayStation 3 (プレイステーション3 Pureisutēshon Surī^?, officially abbreviated as PS3^[5]) is the third home video game console produced by Sony Computer Entertainment and the successor to the PlayStation 2 as part of the PlayStation series. The PlayStation 3 competes with Microsoft's Xbox 360 and Nintendo's Wii as part of the seventh generation of video game consoles.
• A major feature that distinguishes the PlayStation 3 from its predecessors is its unified online gaming service, the PlayStation Network,^[6] which contrasts with Sony's former policy of relying onvideo game developers for online play.^[7] Other major features of the console include its robust multimedia capabilities,^[8] connectivity with the PlayStation Portable,^[9] and its use of the Blu-ray Disc as its primary storage medium.^[10] The PS3 was also the first Blu-ray 2.0-compliant Blu-ray player on the market.^[11]
• The PlayStation 3 was first released on November 11, 2006 in Japan,^[12] November 17, 2006 in North America,^[13] March 16, 2007 in the United Kingdom and Ireland, and March 23, 2007 in mainland Europe and Oceania.^[14][15] Two stock-keeping units were available at launch: a basic model with a 20 GB hard disk drive and a premium model with a 60 GB hard drive and several additional features^[16] (the 20 GB model was not released in Europe or Oceania).^[17] Since then, several revisions have been made to the console's available models, most notably with the release of a new slim model in September 2009 to coincide with rebranding of the console and its logo.^[18][19]

personal computer (PC)

This article is about personal computers in general. For computers generally referred to as "PCs", see IBM PC compatible. For hardware components dealing with personal computers, see Personal computer hardware.

Personal computer
An illustration of a modern personaldesktop computer

• A personal computer (PC) is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator. PCs include any type of computer that is used in a "personal" manner. This is in contrast to the batch processing or time-sharing models which allowed large expensive mainframe systems to be used by many people, usually at the same time, or large data processing systems which required a full-time staff to operate efficiently. It is also in contrast with the more recent trend of controlling software availability through an intervening third party such as the Apple App Store.^[1][2]

• A personal computer may be a desktop computer, a laptop, a tablet PC, or a handheld PC (also called a palmtop). The most common microprocessors in personal computers are x86-compatible CPUs. Software applications for personal computers include word processing, spreadsheets, databases, Web browsers and e-mail clients, games, and myriad personal productivity and special-purpose software applications. Modern personal computers often have connections to the Internet, allowing access to the World Wide Web and a wide range of other resources.
• A PC may be used at home or in an office. Personal computers may be connected to a local area network (LAN), either by a cable or a wireless connection.

While early PC owners usually had to write their own programs to do anything useful with the machines, today's users have access to a wide range of commercial and non-commercial software, which is provided in ready-to-run or ready-to-compile form. Since the 1980s, Microsoft and Intel have dominated much of the personal computer market, first with MS-DOS and then with the Wintel platform.