In Greek times, the metal was known by the name chalkos (χαλκός). Copper was a very important resource for the Romans and Greeks. In Roman times, it became known as aes Cyprium (aes being the generic Latin term for copper alloys such as bronze and other metals, and Cyprium because so much of it was mined in Cyprus). From this, the phrase was simplified to cuprum and then eventually Angliciz ...

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Copper, Copper - History, Copper - Biological role, Copper - Toxicity, Copper - Miscellaneous hazards, Copper - Physical characteristics, Copper - Compounds, Copper - Occurrence, Copper - Tests for copper²⁺ ion, Copper - Applications

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Knowledge of cooking vessels before the development of pottery is minimal due to the limited archaeological evidence. It has been possible to extrapolate likely developments based on methods used by latter peoples. Among the first of the techniques believed to be used by stone age civilizations were improvements to basic roasting. In addition to exposing food to direct heat from either an open fire or hot embers it is possible to cover the food with clay or large leaves before roasting to preserve moisture in the cooked result. Examples of similar tec ...

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Cookware and bakeware, Cookware and bakeware - History, Cookware and bakeware - Metal cookware, Cookware and bakeware - Non-metallic bakeware, Cookware and bakeware - Coated and composite cookware, Cookware and bakeware - Types of cookware, Cookware and bakeware - Types of bakeware, Cookware and bakeware - List of cookware and bakeware

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One of the basic premises of this nutritional theory is that many of the foods that humans eat today are not suitable for consumption due to the extensive preparation and processing methods utilized in today's kitchens. These foods, if eaten in their natural state, are ill-tasting, unchewable, and sometimes toxic to the human body. Without modern processing methods, these foods are, in effect, inedible. See also:

Paleolithic diet, Paleolithic diet - Overview, Paleolithic diet - History, Paleolithic diet - History of the human diet, Paleolithic diet - History of this theory, Paleolithic diet - Practices, Paleolithic diet - Foods in the diet, Paleolithic diet - Foods not in the diet, Paleolithic diet - Intake, Paleolithic diet - Food sources and preparation, Paleolithic diet - Summary, Paleolithic diet - Benefits, Paleolithic diet - Support, Paleolithic diet - Criticism, Paleolithic diet - Cautions about poisoning

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Integrated circuit - The birth of the IC. The integrated circuit was first conceived by a radar scientist, Geoffrey W.A. Dummer (born 1909), working for the Royal Radar Establishment of the British Ministry of Defence, and published in Washington, D.C. on May 7, 1952. Dummer unsuccessfully attempted to build such a circuit in 1956. The first integrated circuits were manufactured independently by two scientists: Jack Kilby of Texas Instruments filed a patent for a "Solid Circuit" made of germanium on Februa ...

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Integrated circuit, Integrated circuit - Introduction, Integrated circuit - Advances in integrated circuits, Integrated circuit - Popularity of ICs, Integrated circuit - Classification and complexity, Integrated circuit - Manufacture, Integrated circuit - Fabrication, Integrated circuit - Packaging, Integrated circuit - History, origins and generations, Integrated circuit - The birth of the IC, Integrated circuit - SSI, MSI, LSI, Integrated circuit - VLSI, Integrated circuit - ULSI, WSI, SOC, Integrated circuit - Other developments, Integrated circuit - Key industrial and academic data, Integrated circuit - Notable ICs, Integrated circuit - Manufacturers, Integrated circuit - VLSI conferences, Integrated circuit - VLSI journals

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There are several basically different types of software architectures in common use. Embedded system - The control loop. In this design, the software simply has a loop. The loop calls subroutines. Each subroutine manages a part of the hardware or software. Interrupts generally set flags, or update counters that are read by the rest of the software. A simple API disables and enables interrupts. Done right, it handles nested calls in nested subroutines, and restores the preceding interrupt state in the out ...

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Embedded system, Embedded system - History, Embedded system - Examples of embedded systems, Embedded system - Characteristics, Embedded system - Design of embedded systems, Embedded system - User interfaces, Embedded system - Platform, Embedded system - Tools, Embedded system - Debugging, Embedded system - Operating system, Embedded system - Built-In Self-Test, Embedded system - Reliability regimes, Embedded system - Start-up, Embedded system - Types of embedded software architectures, Embedded system - The control loop, Embedded system - Nonpreemptive multitasking, Embedded system - Preemptive timers, Embedded system - Preemptive tasks, Embedded system - Office-style operating systems, Embedded system - Exotic custom operating systems

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The Fiskars Corporation was formed in 1649 when a Dutch merchant named Peter Thorwöste was given a charter to establish a blast furnace and forging operation in the small village of Fiskari (Fiskars in Swedish), near Helsinki. In the early years, Fiskars made nails, wire, hoes, and metal reinforced wheels from pig iron. As industrial and economic development accelerated in Europe, Fiskars was on the forefront of innovation, and expanded the knifeworks to become a premier steel and ironworks company, manufacturing agricultural ...

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Fiskars, Fiskars - History, Fiskars - Today, Fiskars - Financial

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Most microcontrollers today are based on the Harvard architecture, which clearly defined the four basic components required for an embedded system. These include a CPU core, memory for the program (ROM or Flash memory), memory for data (RAM), one or more timers (customisable ones and watchdog timers), as well as I/O lines to communicate with external peripherals and complementary resources — all this in a single integrated circuit. A microcontroller differs from a general-purpose CPU chip in that the former generally is quite easy to make ...

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Microcontroller, Microcontroller - Description, Microcontroller - Common microcontrollers, Microcontroller - AMCC, Microcontroller - Atmel, Microcontroller - Cypress MicroSystems, Microcontroller - Freescale Semiconductor, Microcontroller - Fujitsu, Microcontroller - Holtek, Microcontroller - Infineon, Microcontroller - Intel, Microcontroller - Microchip, Microcontroller - National Semiconductor, Microcontroller - NEC, Microcontroller - Philips Semiconductors, Microcontroller - Renesas Tech. Corp., Microcontroller - STMicroelectronics, Microcontroller - Texas Instruments, Microcontroller - Toshiba, Microcontroller - Western Design Center, Microcontroller - Ubicom, Microcontroller - Xilinx, Microcontroller - ZiLOG, Microcontroller - ...And endless BASIC programmed MCUs

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Tubes were ubiquitous in the early generations of electronic devices, such as radios, televisions, and early computers such as the Colossus which used 2000 tubes, the ENIAC which used nearly 18,000 tubes, and the IBM 700 series. Unlike transistors, vacuum tubes are inherently immune to the electromagnetic pulse effect of nuclear explosions. This property kept them in use for military applications long after transistors had replaced them elsewhere. Vacuum tubes are still used for very high-powered applications such as microwave ovens, industrial radio-frequency heatin ...

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Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

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A vast array of devices were built during the 1920-1960 period using vacuum-tube techniques. Most such tubes were rendered obsolete by semiconductors. Vacuum-tube electronic devices still in common use include the magnetron, klystron, photomultiplier and cathode ray tube. The magnetron is the type of tube used in all microwave ovens. In spite of the advancing state of the art in power semiconductor technology, the vacuum tube still has reliability and cost advantages for high-frequency RF power generation. Photomultipliers are still the most ...

See also:

Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Other vacuum tube devices

See also: Discovery of cosmic microwave background radiation The cosmic microwave background was predicted by George Gamow, Ralph Alpher, and Robert Hermann in 1948. Moreover, Alpher and Herman were able to estimate the temperature of the cosmic microwave background to be 5 K.[6] Although there were several previous estimates of the temperature of space (see timeline), these suffered from two flaws. First, they were m ...

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Cosmic microwave background radiation, Cosmic microwave background radiation - Features, Cosmic microwave background radiation - History, Cosmic microwave background radiation - Relationship to the Big Bang, Cosmic microwave background radiation - Temperature, Cosmic microwave background radiation - Primary anisotropy, Cosmic microwave background radiation - Polarization, Cosmic microwave background radiation - Secondary anisotropy, Cosmic microwave background radiation - Microwave background observations, Cosmic microwave background radiation - Analyses, Cosmic microwave background radiation - Low multipoles

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The first recognizably modern embedded system was the Apollo Guidance Computer, developed by Charles Stark Draper at the MIT Instrumentation Laboratory. Each flight to the moon had two. They ran the inertial guidance systems of both the command module and LEM. At the project's inception, the Apollo guidance computer was considered the riskiest item in the Apollo project. The use of the then new monolithic integrated circuits, to reduc ...

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Embedded system, Embedded system - History, Embedded system - Examples of embedded systems, Embedded system - Characteristics, Embedded system - Design of embedded systems, Embedded system - User interfaces, Embedded system - Platform, Embedded system - Tools, Embedded system - Debugging, Embedded system - Operating system, Embedded system - Built-In Self-Test, Embedded system - Reliability regimes, Embedded system - Start-up, Embedded system - Types of embedded software architectures, Embedded system - The control loop, Embedded system - Nonpreemptive multitasking, Embedded system - Preemptive timers, Embedded system - Preemptive tasks, Embedded system - Office-style operating systems, Embedded system - Exotic custom operating systems

Read more here: » Embedded system: Encyclopedia II - Embedded system - History

Embedded systems are computer systems in the widest sense. They include all computers other than those specifically intended as general-purpose computers. Examples of embedded systems range from portable music players to real-time controls for systems like the space shuttle. Most commercial embedded systems are designed to do some task at a low cost. Most, but not all have real-time system constraints that must be met. They may need to be very fast for some functions, but most other functions will probably not need speed. These systems meet their real-time constraints with a combination of special purpose hardwar ...

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Embedded system, Embedded system - History, Embedded system - Examples of embedded systems, Embedded system - Characteristics, Embedded system - Design of embedded systems, Embedded system - User interfaces, Embedded system - Platform, Embedded system - Tools, Embedded system - Debugging, Embedded system - Operating system, Embedded system - Built-In Self-Test, Embedded system - Reliability regimes, Embedded system - Start-up, Embedded system - Types of embedded software architectures, Embedded system - The control loop, Embedded system - Nonpreemptive multitasking, Embedded system - Preemptive timers, Embedded system - Preemptive tasks, Embedded system - Office-style operating systems, Embedded system - Exotic custom operating systems

Read more here: » Embedded system: Encyclopedia II - Embedded system - Characteristics

In the early years of the 21st century there has been renewed interest in vacuum tubes, this time in the form of integrated circuits. The most common design uses a cold cathode field emitter, with electrons emitted from a number of sharp nano-scale tips formed on the surface of a metal cathode. Their advantages include greatly enhanced robustness combined with the ability to provide high power outputs at low power consumptions. Operating on the same principles as traditional tubes, prototype device cathodes have been constructed with ...

See also:

Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Field emitter vacuum tubes

Terraforming - Prose. The term first appeared in a science-fiction novel, Seetee Shock (1949) by Jack Williamson, but the concept pre-dates that work. Olaf Stapledon's Last and First Men (1930) provides the first example in fiction in which Venus is modified, after a long and destructive war with the original inhabitants, who naturally object to the process. Even earlier, H. G. Wells alludes to xeno-terraforming - alien life altering Earth for their own benefit - in his 1898 novel The War of the Worlds. When the Martians arrive they bring with them a red weed that spreads an ...

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Terraforming, Terraforming - History of scholarly study, Terraforming - Ethical issues, Terraforming - Theoretical methods of terraforming, Terraforming - Mars, Terraforming - Venus, Terraforming - Other worlds, Terraforming - Paraterraforming, Terraforming - In fiction, Terraforming - Prose, Terraforming - Television and film, Terraforming - Miscellanea

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Vacuum tubes, or thermionic valves, are arrangements of electrodes in a vacuum within an insulating, temperature-resistant envelope. Although the envelope was classically glass, power tubes often use ceramic and metal. The electrodes are attached to leads which pass through the envelope via an air tight seal. On most tubes, the leads are designed to plug into a tube socket for easy replacement. The simplest vacuum tubes resemble incandescent light bulbs in that they have a filament sealed in a glass envelope which has be ...

See also:

Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Diodes and triodes, Vacuum tube - Tetrodes and pentodes, Vacuum tube - Other variations, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Operation

The chief reliability problem of a tube is that the filament or cathode is slowly "poisoned" by atoms from other elements in the tube, which damage its ability to emit electrons. Trapped gases or slow gas leaks can also damage the cathode or cause plate-current runaway due to ionization of free gas molecules. Vacuum hardness and proper selection of construction materials are the major influences on tube lifetime. (Tube cathodes do not "wear out" as lamp filaments do; th ...

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Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Reliability

While commercial services attempt to move existing business models to Wi-Fi, many groups, communities, cities, and individuals have set up free Wi-Fi networks, often adopting a common peering agreement in order that networks can openly share with each other. Free wireless mesh networks are often considered the future of the internet. Many municipalities have joined with local community groups to help expand free Wi-Fi networks. Some community groups have built their Wi-Fi networks entirely based on volunteer efforts and donations. For more information, see wireless community network, where there is also a list of the free Wi-Fi net ...

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Wi-Fi, Wi-Fi - History, Wi-Fi - Wi-Fi: How it works, Wi-Fi - Wi-Fi vs. cellular, Wi-Fi - Commercial Wi-Fi, Wi-Fi - Free Wi-Fi, Wi-Fi - Advantages of Wi-Fi, Wi-Fi - Disadvantages of Wi-Fi, Wi-Fi - Wi-Fi gaming, Wi-Fi - Wi-Fi and free software, Wi-Fi - Trademark, Wi-Fi - Unintended and intended use by outsiders

Read more here: » Wi-Fi: Encyclopedia II - Wi-Fi - Free Wi-Fi

Vacuum tubes, or thermionic valves, are arrangements of electrodes in a vacuum within an insulating, temperature-resistant envelope. Although the envelope was classically glass, power tubes often use ceramic and metal. The electrodes were attached to leads which passed through the envelope in a way that was sealed air tight. On most tubes, the leads were designed to plug into tube sockets for easy replacement. The simplest vacuum tubes resemble incandescent light bulbs in that they have a filament sealed in a glass envelope whi ...

See also:

Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Operation

The default configuration of most Wi-Fi access points provides no protection from unauthorized use of the network. Many business and residential users do not intend to secure their access points by leaving them open to users in the area. It has become etiquette to leave access points open for others to use just as one can expect to find open access points while on the road. Measures to deter unauthorized users include suppressing the AP's service set identifier (SSID) broadcast, only allowing computers with known MAC addresses to join ...

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Wi-Fi, Wi-Fi - History, Wi-Fi - Wi-Fi: How it works, Wi-Fi - Wi-Fi vs. cellular, Wi-Fi - Commercial Wi-Fi, Wi-Fi - Free Wi-Fi, Wi-Fi - Advantages of Wi-Fi, Wi-Fi - Disadvantages of Wi-Fi, Wi-Fi - Wi-Fi gaming, Wi-Fi - Wi-Fi and free software, Wi-Fi - Trademark, Wi-Fi - Unintended and intended use by outsiders

Read more here: » Wi-Fi: Encyclopedia II - Wi-Fi - Unintended and intended use by outsiders

In the early years of the 21st century there has been renewed interest in vacuum tubes, this time in the form of integrated circuits. The most common design uses a cold cathode field emitter, with electrons emitted from a number of sharp nano-scale tips formed on the surface of a metal cathode. Their advantages include greatly enhanced robustness combined with the ability to provide high power outputs at low power consumptions. Operating on the same principles as traditional tubes, prototype device cathodes have been constructed with ...

See also:

Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Diodes and triodes, Vacuum tube - Tetrodes and pentodes, Vacuum tube - Other variations, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Field emitter vacuum tubes

A vast array of devices were built during the 1920-1960 period using vacuum-tube techniques. Most such tubes were rendered obsolete by semiconductors. Vacuum-tube electronic devices still in common use include the magnetron, klystron, photomultiplier and cathode ray tube. The magnetron is the type of tube used in all microwave ovens. In spite of the advancing state of the art in power semiconductor technology, the vacuum tube still has reliability and cost advantages for high-frequency RF power generation. Photomultipliers are still the most ...

See also:

Vacuum tube, Vacuum tube - Operation, Vacuum tube - Development, Vacuum tube - Diodes and triodes, Vacuum tube - Tetrodes and pentodes, Vacuum tube - Other variations, Vacuum tube - Reliability, Vacuum tube - Applications, Vacuum tube - Other vacuum tube devices, Vacuum tube - Field emitter vacuum tubes, Vacuum tube - Vacuum tube solar heaters, Vacuum tube - Patents

Read more here: » Vacuum tube: Encyclopedia II - Vacuum tube - Other vacuum tube devices

All cavity magnetrons consist of a hot filament (cathode) kept at or pulsed to a high negative potential by a high voltage direct current power supply. The cathode is built into the center of an evacuated, lobed, circular chamber. A perpendicular magnetic field is imposed by a permanent magnet. The magnetic field causes the electrons, attracted to the (relatively) positive outer part of the chamber, to spiral outward in a circular path rather than moving directly to this anode. Spaced about the rim of the chamber are cylindrical cavities. Th ...

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Cavity magnetron, Cavity magnetron - Construction and operation, Cavity magnetron - Applications, Cavity magnetron - Radar, Cavity magnetron - Heating, Cavity magnetron - History, Cavity magnetron - Health hazards, Cavity magnetron - External link

Read more here: » Cavity magnetron: Encyclopedia II - Cavity magnetron - Construction and operation