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Ernst Alexanderson
Ernst Frederick Werner Alexanderson (January 25, 1878 – May 14, 1975) was a Swedish-American electrical engineer, who was a pioneer in radio and television development. He invented the Alexanderson alternator, an early radio transmitter used between 1906 and the 1930s for longwave long distance radio transmission. Alexanderson also created the amplidyne, a direct current amplifier used during the Second World War for controlling anti-aircraft guns. Background Alexanderson was born in Uppsala, Sweden. He studied at the University of Lund (1896–97) and was educated at the Royal Institute of Technology in Stockholm and the Technische Hochschule in Berlin, Germany. He emigrated to the United States in 1902 and spent much of his life working for the General Electric and Radio Corporation of America. Engineering work Alexanderson designed the Alexanderson alternator, an early longwave radio transmitter, one of the first devices which could transmit modulated audio (sound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uppsala, Sweden
Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019. Located north of the capital Stockholm it is also the seat of Uppsala Municipality. Since 1164, Uppsala has been the ecclesiastical centre of Sweden, being the seat of the Archbishop of the Church of Sweden. Uppsala is home to Scandinavia's largest cathedral – Uppsala Cathedral, which was the frequent site of the coronation of the Swedish monarch until the late 19th century. Uppsala Castle, built by King Gustav Vasa, served as one of the royal residences of the Swedish monarchs, and was expanded several times over its history, making Uppsala the secondary capital of Sweden during its greatest extent. Today it serves as the residence of the Governor of Uppsala County. Founded in 1477, Uppsala University is the oldest centre of higher education in Scandinavia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Svenskt Biografiskt Lexikon
''Svenskt biografiskt lexikon'' () is a Swedish biographical dictionary, started in 1917. The first volume, covering names ''Abelin'' to ''Anjou'', was published in 1918. As of 2017, names from A to S are covered. Volumes # ABELIN – ANJOU (1918) # ANKARCRONA – BECKER (1920) # BECK – FRIIS – BERNDES (1922) # BERNDES – BLOCK (1924) # BLOM – BRANNIUS (1925) # BRANT – BYGDÉN (1926) # BÜLOW – CEDERGREN (1927) # CEDERHIELM – CORNELIUS (1929) # CORNELL – DAL (1931) # DíALBEDYHLL – DE LA GARDIE (1931) # DE LA GRANGE – EBERSKÖLD (1945) # EBERSTEIN – EKMAN (1949) # EKMAN – ENWALL (1950) # ENVALLSSON – FAHLBECK (1953) # FAHLBERG – FEUK (1956) # FICH – GEHLIN (1964–1966) # GEIJER – HALL (1967–1969) # HALLARDT – HEURGREN (1969–1971) # HEURLIN – INGE (1971–1973) # INGEBORG – KATARINA (1973–75) # KATARINA – KÖNIGSMARCK (1975–77) # KÖNIGSMARCK – LILJA (1977–79) # LILJEBLAD – LJUNGBERGER (1980–1981) # LJUNGDAHL – MALMROS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brant Rock, Massachusetts
Ocean Bluff-Brant Rock is a census-designated place (CDP) in Plymouth County, Massachusetts, United States, composed of the neighborhoods of Ocean Bluff, Brant Rock, Fieldston, and Rexhame in the town of Marshfield. The population of the CDP was 4,970 at the 2010 census. History Brant Rock and Ocean Bluff were originally inhabited by Native Americans, including members of the Wampanoag tribe of the Algonquian peoples. Native American artifacts have been found extensively in the area. The main road through the area, known today as Ocean Street, is a Native American road, likely very ancient. The area at the end of Brant Rock village, known as Blackman's Point, was a Native American campground. In the 1630s, the government of the Pilgrim settlers at Plymouth began to give out land grants in the area. The Ocean Bluff area was first granted to the governor of the Pilgrims. It was known by about 1638 as "Governor's Island.” Later on in the 17th century, it became known as " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Wave
A continuous wave or continuous waveform (CW) is an electromagnetic wave of constant amplitude and frequency, typically a sine wave, that for mathematical analysis is considered to be of infinite duration. It may refer to e.g. a laser or particle accelerator having a continuous output, as opposed to a pulsed output. Continuous wave is also the name given to an early method of radio transmission, in which a sinusoidal carrier wave is switched on and off. Information is carried in the varying duration of the on and off periods of the signal, for example by Morse code in early radio. In early wireless telegraphy radio transmission, CW waves were also known as "undamped waves", to distinguish this method from damped wave signals produced by earlier ''spark gap'' type transmitters. Radio Transmissions before CW Very early radio transmitters used a spark gap to produce radio-frequency oscillations in the transmitting antenna. The signals produced by these spark-gap transmitt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Waves
Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz ( GHz) and below. At 300 GHz, the corresponding wavelength is 1 mm (shorter than a grain of rice); at 30 Hz the corresponding wavelength is (longer than the radius of the Earth). Like all electromagnetic waves, radio waves in a vacuum travel at the speed of light, and in the Earth's atmosphere at a close, but slightly lower speed. Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents. Naturally occurring radio waves are emitted by lightning and astronomical objects, and are part of the blackbody radiation emitted by all warm objects. Radio waves are generated artificially by an electronic device called a transmitter, which is connected to an antenna which radiates the waves. They are received by another antenna connected to a radio receiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reginald Fessenden
Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father. During his life he received hundreds of patents in various fields, most notably ones related to radio and sonar. Fessenden is best known for his pioneering work developing radio technology, including the foundations of amplitude modulation (AM) radio. His achievements included the first transmission of speech by radio (1900), and the first two-way radiotelegraphic communication across the Atlantic Ocean (1906). In 1932 he reported that, in late 1906, he also made the first radio broadcast of entertainment and music, although a lack of verifiable details has led to some doubts about this claim. Early years Reginald Fessenden was born October 6, 1866, in East Bolton, Quebec, the eldest of the Reverend Elisha Joseph Fessenden and Clementina Trenholme's four children. Elisha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Corporation Of America
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Company. In 1932, RCA became an independent company after the partners were required to divest their ownership as part of the settlement of a government antitrust suit. An innovative and progressive company, RCA was the dominant electronics and communications firm in the United States for over five decades. RCA was at the forefront of the mushrooming radio industry in the early 1920s, as a major manufacturer of radio receivers, and the exclusive manufacturer of the first superheterodyne sets. RCA also created the first nationwide American radio network, the National Broadcasting Company (NBC). The company was also a pioneer in the introduction and development of television, both black and white and especially color television. During this pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energy, digital industry, additive manufacturing and venture capital and finance, but has since divested from several areas, now primarily consisting of the first four segments. In 2020, GE ranked among the Fortune 500 as the 33rd largest firm in the United States by gross revenue. In 2011, GE ranked among the Fortune 20 as the 14th most profitable company, but later very severely underperformed the market (by about 75%) as its profitability collapsed. Two employees of GE – Irving Langmuir (1932) and Ivar Giaever (1973) – have been awarded the Nobel Prize. On November 9, 2021, the company announced it would divide itself into three investment-grade public companies. On July 18, 2022, GE unveiled the brand names of the companies it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin
Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within city limits, most populous city, according to population within city limits. One of Germany's States of Germany, sixteen constituent states, Berlin is surrounded by the Brandenburg, State of Brandenburg and contiguous with Potsdam, Brandenburg's capital. Berlin's urban area, which has a population of around 4.5 million, is the second most populous urban area in Germany after the Ruhr. The Berlin/Brandenburg Metropolitan Region, Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Metropolitan regions in Germany, Germany's third-largest metropolitan region after the Rhine-Ruhr and Frankfurt Rhine-Main, Rhine-Main regions. Berlin straddles the banks of the Spree (river), Spree, which flows into the Havel (a tributary of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technische Hochschule
A ''Technische Hochschule'' (, plural: ''Technische Hochschulen'', abbreviated ''TH'') is a type of university focusing on engineering sciences in Germany. Previously, it also existed in Austria, Switzerland, the Netherlands (), and Finland (, ). In the 1970s (in Germany) and the 1980s (in the Netherlands), the ''Technische Hochschule'' emerged into the (German) or (Dutch). Since 2009, several German universities of applied sciences were renamed as . Terminology In German-language countries, the term ''Hochschule'' is more general than ''Universität'' (plural: ''Universitäten'') and also encompasses universities which do not have the right to confer doctorates and habilitations, in contrast to ''Universitäten''. Today, ''Universitäten'' as well as other ''Hochschulen'' call themselves ''Technische Hochschule'' for historical reasons. However, a ''Technische Hochschule'' with the status of a ''Universität'' is regarded as a ''Technische Universität'' despite the name. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stockholm
Stockholm () is the capital and largest city of Sweden as well as the largest urban area in Scandinavia. Approximately 980,000 people live in the municipality, with 1.6 million in the urban area, and 2.4 million in the metropolitan area. The city stretches across fourteen islands where Lake Mälaren flows into the Baltic Sea. Outside the city to the east, and along the coast, is the island chain of the Stockholm archipelago. The area has been settled since the Stone Age, in the 6th millennium BC, and was founded as a city in 1252 by Swedish statesman Birger Jarl. It is also the county seat of Stockholm County. For several hundred years, Stockholm was the capital of Finland as well (), which then was a part of Sweden. The population of the municipality of Stockholm is expected to reach one million people in 2024. Stockholm is the cultural, media, political, and economic centre of Sweden. The Stockholm region alone accounts for over a third of the country's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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