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Biography
Rube Goldberg
File:Something for nothing (1940).ogv Reuben Garrett Lucius Goldberg (July 4, 1883 – December 7, 1970), known best as Rube Goldberg, was an American cartoonist, sculptor, author, engineer, and inventor. Goldberg is best known for a series of popular cartoons depicting complicated gadgets that perform simple tasks in indirect, convoluted ways, giving rise to the term Rube Goldberg machines for
  • 2.5K
  • 16 Nov 2022
Topic Review
Radio Direction Finder
A radio direction finder (RDF) is a device for finding the direction, or bearing, to a radio source. The act of measuring the direction is known as radio direction finding or sometimes simply direction finding (DF). Using two or more measurements from different locations, the location of an unknown transmitter can be determined; alternately, using two or more measurements of known transmitters, the location of a vehicle can be determined. RDF is widely used as a radio navigation system, especially with boats and aircraft. RDF systems can be used with any radio source, although the size of the receiver antennas are a function of the wavelength of the signal; very long wavelengths (low frequencies) require very large antennas, and are generally used only on ground-based systems. These wavelengths are nevertheless very useful for marine navigation as they can travel very long distances and "over the horizon", which is valuable for ships when the line-of-sight may be only a few tens of kilometres. For aircraft, where the horizon at altitude may extend to hundreds of kilometres, higher frequencies can be used, allowing much smaller antennas. An automatic direction finder, often capable of being tuned to commercial AM radio transmitters, is a feature of almost all modern aircraft. For the military, RDF systems are a key component of signals intelligence systems and methodologies. The ability to locate the position of an enemy transmitter has been invaluable since World War I, and it played a key role in World War II's Battle of the Atlantic. It is estimated that the UK's advanced "huff-duff" systems were directly or indirectly responsible for 24% of all U-boats sunk during the war. Modern systems often use phased array antennas to allow rapid beam forming for highly accurate results. These are generally integrated into a wider electronic warfare suite. Several distinct generations of RDF systems have been used over time, following new developments in electronics. Early systems used mechanically rotated antennas that compared signal strengths from different directions, and several electronic versions of the same concept followed. Modern systems use the comparison of phase or doppler techniques which are generally simpler to automate. Modern pseudo-Doppler direction finder systems consist of a number of small antennas fixed to a circular card, with all of the processing performed by software. Early British radar sets were also referred to as RDF, which was a deception tactic. However, the terminology was not inaccurate; the Chain Home systems used separate omnidirectional broadcasters and large RDF receivers to determine the location of the targets.
  • 2.5K
  • 10 Oct 2022
Topic Review
Interactivity
Across the many fields concerned with interactivity, including information science, computer science, human-computer interaction, communication, and industrial design, there is little agreement over the meaning of the term "interactivity", but most definitions are related to interaction between users and computers and other machines through a user interface. Interactivity can however also refer to interaction between people. It nevertheless usually refers to interaction between people and computers – and sometimes to interaction between computers – through software, hardware, and networks. Multiple views on interactivity exist. In the "contingency view" of interactivity, there are three levels: One body of research has made a strong distinction between interaction and interactivity. As the suffix 'ity' is used to form nouns that denote a quality or condition, this body of research has defined interactivity as the 'quality or condition of interaction'. These researchers suggest that the distinction between interaction and interactivity is important since interaction may be present in any given setting, but the quality of the interaction varies from low and high.
  • 2.5K
  • 26 Oct 2022
Topic Review
South Korean Transitional Periods from Imitation to Innovation
The technology transfer and development model of South Korea is unique. After other countries refused to license and transfer modern technologies to this country, Korea resorted to its national research system to add innovative content to its imitative products. 
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  • 23 Mar 2022
Topic Review
Primitive Clay Oven
The primitive clay oven, or earthen oven / cob oven, has been used since time immemorial by diverse cultures and societies, primarily for, but not exclusive to, baking before the invention of cast-iron stoves, and gas and electric ovens. The general build and shape were, mostly, common to all peoples, with only slight variations in size and in materials used to construct the oven. In primitive courtyards and farmhouses, earthen ovens were built on the ground. In Arabian, Palestinian, Middle-Eastern and North-African societies, bread was often baked within a clay oven called in some Arabic dialects a tabun (also transliterated taboon, from the Arabic: طابون), or else in a clay oven called a tannour, and in other dialects mas'ad. The clay oven, synonymous with the Hebrew word tannour (= oven), was shaped like a truncated cone, with an opening either at the top or bottom from which to stoke the fire. Others were made cylindrical with an opening at the top. Built and used in biblical times as the family, neighbourhood, or village oven, clay ovens continue to be made in parts of the Middle East today.
  • 2.5K
  • 22 Nov 2022
Topic Review
Freeze-Drying of Foods
Freeze-drying is a process in which water is sublimated by the direct transition of water from solid (ice) to vapor, thus omitting the liquid state, and then desorbing water from the “dry” layer.
  • 2.5K
  • 16 Nov 2020
Topic Review
Carbon Fiber Reinforced Polymer
Carbon fiber reinforced polymer (American English), Carbon fibre reinforced polymer (Commonwealth English), or carbon fiber reinforced plastic, or carbon fiber reinforced thermoplastic (CFRP, CRP, CFRTP, or often simply carbon fiber, carbon composite, or even carbon), is an extremely strong and light fiber-reinforced plastic which contains carbon fibers. The spelling 'fibre' is typically used outside the US. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications. The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The composite material may contain aramid (e.g. Kevlar, Twaron), ultra-high-molecular-weight polyethylene (UHMWPE), aluminium, or glass fibers in addition to carbon fibers. The properties of the final CFRP product can also be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other additives such as rubber and carbon nanotubes can be used. The material is also referred to as graphite-reinforced polymer or graphite fiber-reinforced polymer (GFRP is less common, as it clashes with glass-(fiber)-reinforced polymer).
  • 2.5K
  • 28 Nov 2022
Topic Review
Dugout Canoe
A dugout canoe or simply dugout is a boat made from a hollowed tree. Other names for this type of boat are logboat and monoxylon. Monoxylon (μονόξυλον) (pl: monoxyla) is Greek -- mono- (single) + ξύλον xylon (tree) -- and is mostly used in classic Greek texts. In German, they are called Einbaum ("one tree" in English). Some, but not all, pirogues are also constructed in this manner. Dugouts are the oldest boat type archaeologists have found, dating back about 8,000 years to the Neolithic Stone Age. This is probably because they are made of massive pieces of wood, which tend to preserve better than, e.g., bark canoes. Along with bark canoe and hide kayak, dugout boats were also used by indigenous peoples of the Americas.
  • 2.4K
  • 25 Oct 2022
Topic Review
Electromagnetic Aircraft Launch System
The Electromagnetic Aircraft Launch System (EMALS) is a type of aircraft launching system developed by General Atomics for the United States Navy. The system launches carrier-based aircraft by means of a catapult employing a linear induction motor rather than the conventional steam piston. EMALS was first installed on the United States Navy's Gerald R. Ford-class aircraft carrier, USS Gerald R. Ford. Its main advantage is that it accelerates aircraft more smoothly, putting less stress on their airframes. Compared to steam catapults, the EMALS also weighs less, is expected to cost less and require less maintenance, and can launch both heavier and lighter aircraft than a steam piston-driven system. It also reduces the carrier's requirement of fresh water, thus reducing the demand for energy-intensive desalination. China is reportedly developing a similar system which is expected to be used on China's Type 003 aircraft carriers.
  • 2.4K
  • 21 Nov 2022
Topic Review
Indian Regional Navigation Satellite System
The Indian Regional Navigation Satellite System (IRNSS), with an operational name of NAVIC (acronym for NAVigation with Indian Constellation; also, nāvik 'sailor' or 'navigator' in Sanskrit, Hindi, and many other Indian languages), is an autonomous regional satellite navigation system that provides accurate real-time positioning and timing services. It covers India and a region extending 1,500 km (930 mi) around it, with plans for further extension. An extended service area lies between the primary service area and a rectangle area enclosed by the 30th parallel south to the 50th parallel north and the 30th meridian east to the 130th meridian east, 1,500–6,000 km (930–3,730 mi) beyond borders. The system currently consists of a constellation of seven satellites, with two additional satellites on ground as stand-by. The constellation is in orbit as of 2018, and the system was expected to be operational from early 2018 after a system check. NAVIC will provide two levels of service, the "standard positioning service", which will be open for civilian use, and a "restricted service" (an encrypted one) for authorised users (including the military). NAVIC is planned to become available for civilian use in the first half of 2020. There are plans to expand the NAVIC system by increasing its constellation size from 7 to 11.
  • 2.4K
  • 12 Oct 2022
Topic Review
Devices Using Qualcomm Snapdragon Systems-on-Chip
This is a list of devices using Qualcomm Snapdragon chips. Snapdragon is a family of mobile system on a chip (SoC) made by Qualcomm for use in smartphones, tablets, and smartbook devices.
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  • 07 Nov 2022
Topic Review
Furfuryl Alcohol
Furfuryl alcohol (FuOH, C4H3OCH2OH, 2-furylmethanol, 2-furancarbinol) has applications in the fabrication of foundry resins, the ingredient production of P-series fuels, in liquid alkanes and in food production. It is also a very important intermediate in fine chemical synthesis and the polymer industry, and it is used as a chemical intermediate for the synthesis of lysine, vitamin C and levulinic acid and employed as a lubricant and as a dispersing agent.
  • 2.4K
  • 10 Oct 2020
Topic Review
Comet Lake
Comet Lake is Intel's codename for its 10th generation Core microprocessors. They are manufactured using Intel's third 14 nm Skylake process refinement, succeeding the Whiskey Lake U-series mobile processor and Coffee Lake desktop processor families. Intel announced low-power mobile Comet Lake-U CPUs on August 21, 2019, H-series mobile CPUs on April 2, 2020, desktop Comet Lake-S CPUs April 30, 2020, and Xeon W-1200 series workstation CPUs on May 13, 2020. Comet Lake processors and Ice Lake 10 nm processors are together branded as the Intel "10th Generation Core" family. Intel officially launched Comet Lake-Refresh CPUs on the same day as 11th Gen Core Rocket Lake launch. The low-power mobile Comet Lake-U Core and Celeron 5205U CPUs were discontinued on July 7, 2021.
  • 2.4K
  • 21 Nov 2022
Topic Review
Capital Centre
The Capital Centre (later USAir Arena and US Airways Arena) was an indoor arena in the eastern United States, located in Landover, Maryland, east of Washington, D.C. Opened in late 1973, it closed in 1999, and was demolished in 2002. The seating capacity was 18,756 for basketball and 18,130 for hockey. The elevation at street level was approximately 160 feet (50 m) above sea level. The U.S. Census Bureau defined the land, later occupied by The Boulevard at the Capital Centre, as being in the Mitchellville census-designated place as of the 1990 U.S. Census, while in the 2000 U.S. Census the area was placed in the Lake Arbor CDP.
  • 2.3K
  • 28 Nov 2022
Topic Review
Classic Car
A classic car is an older automobile; the exact definition varies around the world. The common theme is of an older car with enough historical interest to be collectable and worth preserving or restoring rather than scrapping. Cars 20 years and older typically fall into the classic class. Organizations such as the Classic Car Club of America (CCCA) and the Antique Automobile Club of America (AACA) maintain a list of eligible unmodified cars that are called "classic". These are described as "fine" or "distinctive" automobile, either American or foreign built, produced between 1915 to 1998. Post–World War II "classic cars" are not precisely defined and the term is often applied to any older vehicle.
  • 2.3K
  • 02 Nov 2022
Topic Review
Vinylidene Fluoride
1,1-difluoroethylene (VDF) is one of the major fluoromonomers, which are the feedstock for the production of various resins, rubbers membrane and paints. The polymers derived from VDF (PVDF) or co-polymers with unique chemical resistance, stability at elevated temperatures, oxidation resistance, weatherability, piezoelectricity, dielectric and thermoelectricity, find wide applications in areas including petrochemical, electronic and electrical, and fluorocarbon coating. VDF is the second largest product among fluorocarbons with an annual production capacity of above 53,000 tons. The demand for VDF is increasing rapidly. At present, in industry, VDF is usually produced via the dehydrochlorination of 1,1-difluoro-1-chloroethane (HCFC-142b) at reaction temperatures above 650 °C
  • 2.3K
  • 30 Oct 2020
Topic Review
List of Intel Pentium 4 Microprocessors
The Pentium 4 microprocessor from Intel is a seventh-generation CPU targeted at the consumer market.
  • 2.3K
  • 02 Oct 2022
Topic Review
E-Bike Sharing System
Recent data on conventional bike and/or electric bike (e-bike) sharing systems reveal that more than 2900 systems are operating in cities worldwide, indicating the increased adoption of this alternative mode of transportation. Addressing the existing gap in the literature regarding the deployment of e-bike sharing systems (e-BSSs) in particular, this paper reviews their spatio-temporal characteristics, and attempts to (a) map the worldwide distribution of e-BSSs, (b) identify temporal trends in terms of annual growth/expansion of e-BSS deployment worldwide and (c) explore the spatial characteristics of the recorded growth, in terms of adoption on a country scale, population coverage and type of system/initial fleet sizes. To that end, it examines the patterns identified from the global to the country level, based on data collected from an online source of BSS information worldwide. A comparative analysis is performed with a focus on Europe, North America and Asia, providing insights on the growth rate of the specific bikesharing market segment. Although the dockless e-BSS has been only within three years of competition with station-based implementations, it shows a rapid integration to the overall technology diffusion trend, while it is more established in Asia and North America in comparison with Europe and launches with larger fleet sizes.
  • 2.3K
  • 27 Oct 2020
Topic Review
Interferometric Fiber Optic Sensors
Due to the improvement of living standards, people’s attention to health has gradually increased. More and more people are willing to spend money and time on health management. The vital signs monitoring system based on fiber optic interferometers, including the design of sensor structures, signal demodulation methods and data analysis. After a large number of trials, the system can achieve long-term stable heart rate (HR), respiration rate (RR) and body temperature monitoring, and the collected data can be used for health analysis. Due to the high sensitivity, low cost, and light weight of the interferometric fiber optic sensor, it can be integrated under a mattress or a cushion, which is very suitable for daily use. The system has great application prospects in the field of healthcare. 
  • 2.3K
  • 26 Jan 2022
Topic Review
Differential Signaling
Differential signaling is a method for electrically transmitting information using two complementary signals. The technique sends the same electrical signal as a differential pair of signals, each in its own conductor. The pair of conductors can be wires in a twisted-pair or ribbon cable or traces on a printed circuit board. Electrically, the two conductors carry voltage signals which are equal in magnitude, but of opposite polarity. The receiving circuit responds to the difference between the two signals, which results in a signal a magnitude twice as large. Any interference caused by the transmission of differential signals tend to cancel out resulting in reduced emission that could affect nearby circuits.
  • 2.3K
  • 02 Nov 2022
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