Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. The word engineer (Latiningeniator, the origin of the Ir. in the title of engineer in countries like Belgium, The Netherlands, and Indonesia) is derived from the Latin words ingeniare ("to contrive, devise") and ingenium ("cleverness"). The foundational qualifications of a licensed professional engineer typically include a four-year bachelor's degree in an engineering discipline, or in some jurisdictions, a master's degree in an engineering discipline plus four to six years of peer-reviewed professional practice (culminating in a project report or thesis) and passage of engineering board examinations. (Full article...)
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For thousands of years, devices have been used to measure and keep track of time. The current sexagesimalsystem of time measurement dates to approximately 2000 BCE from the Sumerians.
The Ancient Egyptians divided the day into two 12-hour periods, and used large obelisks to track the movement of the sun. They also developed water clocks, which were probably first used in the Precinct of Amun-Re, and later outside Egypt as well; they were employed frequently by the Ancient Greeks, who called them clepsydrae. The Zhou dynasty is believed to have used the outflow water clock around the same time, devices which were introduced from Mesopotamia as early as 2000 BCE.
Other ancient timekeeping devices include the candle clock, used in ancient China, ancient Japan, England and Mesopotamia; the timestick, widely used in India and Tibet, as well as some parts of Europe; and the hourglass, which functioned similarly to a water clock. The sundial, another early clock, relies on shadows to provide a good estimate of the hour on a sunny day. It is not so useful in cloudy weather or at night and requires recalibration as the seasons change (if the gnomon was not aligned with the Earth's axis). (Full article...)
... that during the British period, the tomb of Khan Muhammad was used as an office and residence for the executive engineer?
... that a 16-year-old high-school student reverse-engineered iMessage to let Android users text iPhone users with blue chat bubbles using the Beeper Mini app?
... that a drillship is a maritime vessel that has been fitted with drilling apparatus?
The Beijing National Aquatics Center, also known as the Water Cube, is an aquatics centre that was built alongside Beijing National Stadium in the Olympic Green for the 2008 Summer Olympics. Ground was broken on December 24, 2003. The Aquatics Centre hosted the swimming, diving, synchronized swimming and water polo events during the Olympics. It had a capacity of 17,000 during the games that has been reduced to 6,000. It also has a total land surface of 65,000 square metres.
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Schematic representation of the Dirac delta function by a line surmounted by an arrow. The height of the arrow is usually meant to specify the value of any multiplicative constant, which will give the area under the function. The other convention is to write the area next to the arrowhead. In mathematical analysis, the Dirac delta function (or δ distribution), also known as the unit impulse, is a generalized function on the real numbers, whose value is zero everywhere except at zero, and whose integral over the entire real line is equal to one. Thus it can be represented heuristically as
The Avrocar S/N 58-7055 (marked AV-7055) on its rollout.
The Avro Canada VZ-9 Avrocar is a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single "turborotor" blowing exhaust out of the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer.
Originally designed as a fighter-like aircraft capable of very high speeds and altitudes, the project was repeatedly scaled back over time and the U.S. Air Force eventually abandoned it. Development was then taken up by the U.S. Army for a tactical combat aircraft requirement, a sort of high-performance helicopter. In flight testing, the Avrocar proved to have unresolved thrust and stability problems that limited it to a degraded, low-performance flight envelope; subsequently, the project was cancelled in September 1961. (Full article...)
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Replica of the original Fat Man bomb
"Fat Man" (also known as Mark III) was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. It is also the most powerful design to ever be used in warfare.
Nichols remained with the Manhattan Project after the war until it was taken over by the Atomic Energy Commission in 1947. He was the military liaison officer with the Atomic Energy Commission from 1946 to 1947. After briefly teaching at the United States Military Academy at West Point, he was promoted to major general and became chief of the Armed Forces Special Weapons Project, responsible for the military aspects of atomic weapons, including logistics, handling and training. He was deputy director for the Atomic Energy Matters, Plans and Operations Division of the Army's general staff, and was the senior Army member of the military liaison committee that worked with the Atomic Energy Commission. (Full article...)
HDMI implements the ANSI/CTA-861 standard, which defines video formats and waveforms, transport of compressed and uncompressed LPCM audio, auxiliary data, and implementations of the VESA EDID. CEA-861 signals carried by HDMI are electrically compatible with the CEA-861 signals used by the Digital Visual Interface (DVI). No signal conversion is necessary, nor is there a loss of video quality when a DVI-to-HDMI adapter is used. The Consumer Electronics Control (CEC) capability allows HDMI devices to control each other when necessary and allows the user to operate multiple devices with one handheld remote control device. (Full article...)
The Sinclair C5 is a small one-person battery electricrecumbenttricycle, technically an "electrically assisted pedal cycle". It was the culmination of Sir Clive Sinclair's long-running interest in electric vehicles. Although widely described as an "electric car", Sinclair characterised it as a "vehicle, not a car".
Sinclair had become one of the UK's best-known millionaires, and earned a knighthood, on the back of the highly successful Sinclair Research range of home computers in the early 1980s. He hoped to repeat his success in the electric vehicle market, which he saw as ripe for a new approach. The C5 emerged from an earlier project to produce a small electric car called the C1. After a change in the law, prompted by lobbying from bicycle manufacturers, Sinclair developed the C5 as an electrically powered tricycle with a polypropylene body and a chassis designed by Lotus Cars. It was intended to be the first in a series of increasingly ambitious electric vehicles, but the development of the follow-up C10 and C15 models never progressed further than the drawing board, mostly due to the poor public response to the C5. (Full article...)
Bell was an energetic and skilful entrepreneur as well as an innovative metallurgist. He was involved in multiple partnerships with his brothers to make iron and alkali chemicals, and with other pioneers including Robert Stirling Newall to make steel cables. He pioneered the large-scale manufacture of aluminium at his Washington works, conducting experiments in its production, and in the production of other chemicals such as the newly discovered element thallium. He was a director of major companies including the North Eastern Railway and the Forth Bridge company, then the largest bridge project in the world. (Full article...)
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A voltage doubler is an electronic circuit which charges capacitors from the input voltage and switches these charges in such a way that, in the ideal case, exactly twice the voltage is produced at the output as at its input.
The simplest of these circuits is a form of rectifier which take an AC voltage as input and outputs a doubled DC voltage. The switching elements are simple diodes and they are driven to switch state merely by the alternating voltage of the input. DC-to-DC voltage doublers cannot switch in this way and require a driving circuit to control the switching. They frequently also require a switching element that can be controlled directly, such as a transistor, rather than relying on the voltage across the switch as in the simple AC-to-DC case. (Full article...)
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The radius of maximum wind of a tropical cyclone lies just within the eyewall of an intense tropical cyclone, such as Hurricane Isabel from 2003 The radius of maximum wind (RMW) is the distance between the center of a cyclone and its band of strongest winds. It is a parameter in atmospheric dynamics and tropical cyclone forecasting. The highest rainfall rates occur near the RMW of tropical cyclones. The extent of a cyclone's storm surge and its maximum potential intensity can be determined using the RMW. As maximum sustained winds increase, the RMW decreases. Recently, RMW has been used in descriptions of tornadoes. When designing buildings to prevent against failure from atmospheric pressure change, RMW can be used in the calculations. (Full article...)
The Castaing machine is a device used to add lettering and decoration to the edge of a coin. Such lettering was necessitated by counterfeiting and edge clipping, which was a common problem resulting from the uneven and irregular hammered coinage. When Aubin Olivier introduced milled coinage to France, he also developed a method of marking the edges with lettering which would make it possible to detect if metal had been shaved from the edge. This method involved using a collar, into which the metal flowed from the pressure of the press. This technique was slower and more costly than later methods. France abandoned milled coinage in favour of hammering in 1585.
England experimented briefly with milled coinage, but it wasn't until Peter Blondeau brought his method of minting coins there in the mid-seventeenth century that such coinage began in earnest in that country. Blondeau also invented a different method of marking the edge, which was, according to him, faster and less costly than the method pioneered by Olivier. Though Blondeau's exact method was secretive, numismatists have asserted that it likely resembled the later device invented by Jean Castaing. Castaing's machine marked the edges by means of two steel rulers, which, when a coinage blank was forced between them, imprinted legends or designs on its edge. Castaing's device found favour in France, and it was eventually adopted in other nations, including Britain and the United States, but it was eventually phased out by mechanised minting techniques. (Full article...)
A hypothetical depiction of a Dyson swarm surrounding a star
A Dyson sphere is a hypothetical megastructure that encompasses a star and captures a large percentage of its power output. The concept is a thought experiment that attempts to imagine how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet's resources alone. Because only a tiny fraction of a star's energy emissions reaches the surface of any orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy.
The first modern imagining of such a structure was by Olaf Stapledon in his science fiction novel Star Maker (1937). The concept was later explored by the physicist Freeman Dyson in his 1960 paper "Search for Artificial Stellar Sources of Infrared Radiation". Dyson speculated that such structures would be the logical consequence of the escalating energy needs of a technological civilization and would be a necessity for its long-term survival. A signature of such spheres detected in astronomical searches would be an indicator of extraterrestrial intelligence. (Full article...)
Image 13Design of a turbine requires collaboration of engineers from many fields, as the system involves mechanical, electro-magnetic and chemical processes. The blades, rotor and stator as well as the steam cycle all need to be carefully designed and optimized. (from Engineering)
Image 22A drawing for a steam locomotive. Engineering is applied to design, with emphasis on function and the utilization of mathematics and science. (from Engineering)
Image 28Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks (from Engineering)
Image 29The application of the steam engine allowed coke to be substituted for charcoal in iron making, lowering the cost of iron, which provided engineers with a new material for building bridges. This bridge was made of cast iron, which was soon displaced by less brittle wrought iron as a structural material. (from Engineering)
Image 30Archimedes is regarded as one of the leading scientists in classical antiquity whose ideas have underpinned much of the practice of engineering. (from Engineer)
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