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Train Whistle
A train whistle or air whistle (originally referred to as a steam trumpet) is an audible signaling device on a steam locomotive, used to warn that the train is approaching, and to communicate with rail workers. Modern diesel and electric locomotives primarily use a powerful air horn instead of a whistle as an audible warning device. However, the word ''whistle'' continues to be used by railroaders in referring to such signaling practices as "whistling off" (sounding the horn when a train gets underway). The need for a whistle on a locomotive exists because trains move on fixed rails and thus are uniquely susceptible to collision. This susceptibility is exacerbated by a train's enormous weight and inertia, which make it difficult to quickly stop when encountering an obstacle. Hence a means of warning others of the approach of a train from a distance is necessary. As train whistles are inexpensive compared to other warning devices, the use of loud and distinct whistles became the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
60163 Tornado Front Whistle
6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number. In mathematics Six is the smallest positive integer which is neither a square number nor a prime number; it is the second smallest composite number, behind 4; its proper divisors are , and . Since 6 equals the sum of its proper divisors, it is a perfect number; 6 is the smallest of the perfect numbers. It is also the smallest Granville number, or \mathcal-perfect number. As a perfect number: *6 is related to the Mersenne prime 3, since . (The next perfect number is 28.) *6 is the only even perfect number that is not the sum of successive odd cubes. *6 is the root of the 6-aliquot tree, and is itself the aliquot sum of only one other number; the square number, . Six is the only number that is both the sum and the product of three consecutive positive numbers. Unrelated to 6's being a perfect number, a Golomb ruler of length 6 is a "perfect ruler". Six is a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lydham Manor 7827 Didcot (Whistles)
Lydham is a small village and civil parish in Shropshire, England. Lydham is situated on the junction of the A488 and the A489 main roads, about 2 miles (3.2 km) north of Bishop's Castle. There is a market held on Fridays in the village hall. Close by is the small village and separate parish of More. History Two miles to the south-east, in the parish of Lydham, are the fragmentary remains of Lea Castle, adjoining a modern farmhouse at Lower Lea. Railway Lydham was served by the now defunct Bishops Castle Railway which closed in 1935. The station was nearby at Lydham Heath. See also *Listed buildings in Lydham Lydham is a civil parish in Shropshire, England. It contains 39 listed buildings that are recorded in the National Heritage List for England. Of these, one is at Grade II*, the middle of the three grades, and the others are at Grade I ... References External links www.geograph.co.uk : photos of Lydham and surrounding area Villages in Shropshir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Effect
The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer. Compared to the emitted frequency, the received frequency is higher during the approach, identical at the instant of passing by, and lower during the recession. The reason for the Doppler effect is that when the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the crest of the previous wave. Therefore, each wave takes slightly less time to reach the observer than the previous wave. Hence, the time between the arrivals of successive wave crests at the observer is reduced, causing an increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland across Estonia to the south. Finland covers an area of with a population of 5.6 million. Helsinki is the capital and largest city, forming a larger metropolitan area with the neighbouring cities of Espoo, Kauniainen, and Vantaa. The vast majority of the population are ethnic Finns. Finnish, alongside Swedish, are the official languages. Swedish is the native language of 5.2% of the population. Finland's climate varies from humid continental in the south to the boreal in the north. The land cover is primarily a boreal forest biome, with more than 180,000 recorded lakes. Finland was first inhabited around 9000 BC after the Last Glacial Period. The Stone Age introduced several differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of Norway. Bouvet Island, located in the Subantarctic, is a dependency of Norway; it also lays claims to the Antarctic territories of Peter I Island and Queen Maud Land. The capital and largest city in Norway is Oslo. Norway has a total area of and had a population of 5,425,270 in January 2022. The country shares a long eastern border with Sweden at a length of . It is bordered by Finland and Russia to the northeast and the Skagerrak strait to the south, on the other side of which are Denmark and the United Kingdom. Norway has an extensive coastline, facing the North Atlantic Ocean and the Barents Sea. The maritime influence dominates Norway's climate, with mild lowland temperatures on the se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Train Horn
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often known simply as "engines"), though some are self-propelled, such as multiple units. Passengers and cargo are carried in railroad cars, also known as wagons. Trains are designed to a certain gauge, or distance between rails. Most trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport. Trains have their roots in wagonways, which used railway tracks and were powered by horses or pulled by cables. Following the invention of the steam locomotive in the United Kingdom in 1804, trains rapidly spread around the world, allowing freight and passengers to move over land faster and cheaper than ever possible before. Rapid transit and trams were first built in the late 1800s to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calliope (music)
A calliope (see below for pronunciation) is an American and Canadian musical instrument that produces sound by sending a gas, originally steam or, more recently, compressed air, through large whistles—originally locomotive whistles. A calliope is typically very loud. Even some small calliopes are audible for miles. There is no way to vary tone or loudness. Musically, the only expression possible is the pitch, rhythm, and duration of the notes. The steam calliope is also known as a steam organ (''orgue à vapeur'' in Quebec) or steam piano (''piano à vapeur'' in Quebec). The air-driven calliope is sometimes called a calliaphone, the name given to it by Norman Baker, but the "Calliaphone" name is registered by the Miner Company for instruments produced under the Tangley name. In the age of steam, the steam calliope was particularly used on riverboats and in circuses. In both cases, a steam supply was readily available for other purposes. Riverboats supplied steam from thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Railroad Administration
The Federal Railroad Administration (FRA) is an agency in the United States Department of Transportation (DOT). The agency was created by the Department of Transportation Act of 1966. The purpose of the FRA is to promulgate and enforce rail safety regulations, administer railroad assistance programs, conduct research and development in support of improved railroad safety and national rail transportation policy, provide for the rehabilitation of Northeast Corridor rail passenger service, and consolidate government support of rail transportation activities. The FRA is one of ten agencies within DOT concerned with intermodal transportation. It operates through seven divisions under the offices of the Administrator and Deputy Administrator. These divisions are: Financial Management and Administration, Chief Counsel, Civil Rights, Public Affairs, Public Engagement, Railroad Policy and Development, and Safety. It has a staff of about 850. Function All passenger and freight rail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABC News
ABC News is the news division of the American broadcast network ABC. Its flagship program is the daily evening newscast ''ABC World News Tonight, ABC World News Tonight with David Muir''; other programs include Breakfast television, morning news-talk show ''Good Morning America'', ''Nightline'', ''Primetime (American TV program), Primetime'', and ''20/20 (American TV program), 20/20'', and Sunday morning talk shows, Sunday morning political affairs program ''This Week (ABC TV series), This Week with George Stephanopoulos''. In addition to the division's television programs, ABC News has radio and digital outlets, including ABC News Radio and ABC News Live, plus various podcasts hosted by ABC News personalities. History Early years ABC began in 1943 as the Blue Network, NBC Blue Network, a radio network that was Corporate spin-off, spun off from NBC, as ordered by the Federal Communications Commission (FCC) in 1942. The reason for the order was to expand competition in radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quality Of Life
Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns". Standard indicators of the quality of life include wealth, employment, the environment, physical and mental health, education, recreation and leisure time, social belonging, religious beliefs, safety, security and freedom. QOL has a wide range of contexts, including the fields of international development, healthcare, politics and employment. Health related QOL (HRQOL) is an evaluation of QOL and its relationship with health. Engaged theory One approach, called engaged theory, outlined in the journal of ''Applied Research in the Quality of Life'', posits four domains in assessing quality of life: ecology, economics, politics and culture. In the domain of culture, for example, it includes the following subdomains of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 10 (approximately ). The unit expresses a relative change or an absolute value. In the latter case, the numeric value expresses the ratio of a value to a fixed reference value; when used in this way, the unit symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is " V" (e.g., "20 dBV"). Two principal types of scaling of the decibel are in common use. When expressing a power ratio, it is defined as ten times the logarithm in base 10. That is, a change in ''power'' by a factor of 10 corresponds to a 10 dB change in level. When expressing root-power quantities, a change in ''ampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horn Loudspeaker
A horn loudspeaker is a loudspeaker or loudspeaker element which uses an horn (acoustic), acoustic horn to increase the overall efficiency of the driving element(s). A common form ''(right)'' consists of a compression driver which produces sound waves with a small metal diaphragm vibrated by an electromagnet, attached to a horn, a flaring duct to conduct the sound waves to the open air. Another type is a woofer driver mounted in a loudspeaker enclosure which is divided by internal partitions to form a zigzag flaring duct which functions as a horn; this type is called a ''folded horn'' speaker. The horn serves to improve the coupling efficiency between the speaker driver and the air. The horn can be thought of as an "acoustic transformer" that provides impedance matching between the relatively density, dense diaphragm material and the less-dense air. The result is greater acoustic output power from a given driver. The narrow part of the horn next to the driver is called the "throat" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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