omniomni/omni-engineering huggingface dataset:
Arimine Dam. The  is located in Toyama, Toyama Prefecture, Japan built upon the Wada River. The two bends in the middle of the dam is the most defining feature. The Arimine Lake is an artificial lake that was created by construction of the dam.

History
The tributaries of the Jōganji River were found to be very attractive for hydroelectric power in the early 20th century due to their high flow and mountainous geography. This caught the attention of the electric utility of the time, the Etchu Electric Power Company, and for the purpose of electricity built a dam on the Wada River. At around the same time the Toyama Prefecture was considering a dam for purposes of flood control and irrigation. Construction of a prefecture managed dam began before World War II but the start of the war halted construction. Later, the Hokuriku Electric Power Company inherited the unfinished dam due to restructuring of the power companies. The plans changed to make the primary purpose of the dam electricity production and was finished in the 50s. It now contributes to electric power as well as irrigation and flood control.

See also

 List of dams and reservoirs in Japan

References

Dams in Toyama Prefecture
Gravity dams
Hydroelectric power stations in Japan
Dams completed in 1959
Tokuyama Dam. The  is an embankment dam near Ibigawa, Ibi District, Gifu Prefecture in Japan. The dam was completed in 2008 and will support a 153 MW hydroelectric power station that is expected to be fully operational in 2015. Unit 1 at 23 MW was commissioned in May 2014. The dam was originally intended to withhold the upper reservoir of a 400 MW pumped-storage power station until a design change in 2004. The dam is also intended for flood control and water supply. It is the largest dam by structural volume in Japan and withholds the country's largest reservoir by volume as well.

History
In December 1957, Electric Power Development Company (J-Power) selected the Ibi River for study at the 23rd Electric Power Development Coordinating Meeting. By May 1976, the Ministry of Construction released their bulletin "Policy on Tokuyama Dam Construction Project". In December 1982, the project was incorporated into the Electric Power Development Basic Plan. It was approved by the government in 1998. The original project was a pumped-storage hydroelectric scheme which consisted of the Tokuyama Dam as the upper reservoir, the Sugihara Dam as the lower and the 400 MW Sugihara Power Plant.

The dam is named after the village that was flooded by the construction of the dam.

Construction on the dam started in May 2000 but by May 2004 J-Power and Chubu Electric announced they had changed the design of the project due to the concerns and protests of locals and groups. Instead of the pumped-storage hydroelectric scheme, only the Tokuyama Dam was to be constructed with a 153-MW conventional power station. Subsequently, the Sugihara Dam and Sugihara Power Plant were scrapped from the project. During construction, the  long Tokunoyama Hattoku Bridge was constructed upstream. With improved techniques and equipment, fill for the dam was laid at a pace of  per year, enabling the dam to be constructed in 26 months. Sediment from the Yokoyama Dam's reservoir was used as fill as well. In September 2006 initial filling of the reservoir behind the Tokuyama Dam began and by June 2008, the dam was complete. Filling was complete in September. In October of the same year, J-Power passed oversight of the power station construction to Chubu. The first generator, Unit 1, was commissioned on 15 May 2014. Unit 2 should be commissioned by June 2015.

Design
The Tokuyama Dam is a  long and  high rock-fill embankment dam with a clay core. The total structural volume of the dam is . The dam creates a reservoir with a  capacity, surface area of  and catchment area of . The dam will support two Francis turbine-generators, one with a 130 MW capacity which will be located in an underground power station downstream. The second is an operational 23 MW generator and is located at the base of the dam. The installed capacity of both will be 153 MW. The power station will process a maximum of  for power production.

References

External links

Chubu Electric new projects

Hydroelectric power stations in Japan
Rock-filled dams
Dams in Gifu Prefecture
Dams completed in 2008
Underground power stations
2008 establishments in Japan
Ibi District, Gifu
Raman School Bhopal. Raman Higher Secondary School was one of the oldest schools in Bhopal. This school was established in 1963 by Bharat Heavy Electrical Education Society (now part of BHEL Shiksha Mandal Bhopal, with funding from the public sector engineering company Bharat Heavy Electricals Limited (BHEL) Bhopal.

Etymology
The school was named after C. V. Raman, an Indian scientist who was awarded the 1930 Nobel Prize in Physics for his work on the scattering of light and for the discovery of the Raman effect.

History
Established in 1963, the school has witnessed an array of changes and modifications. At first the school was run in a TRT Camps as Raman Middle School (Govindpura) - TRT(Temporary Residential Tenements) Camps were built to facilitate the labours and workers of (NBCC) (National Building construction corporation) involved in construction of the houses. The new (existing) building for the school was later built, spread over  land, and the higher secondary section shifted there. It was named Raman Middle School (later renamed to Bhabha Middle school - TRT Campus) with primary and middle school classes. 

In 2002 Bhabha middle school was closed and the entire school was consolidated in one building. In 2007 N. U. K. Menon succeeded former principal A. N. Mishra on the latter's retirement and remained for one year. In the 2008-09 session the school was closed by BHEL Shiksha Mandal Bhopal, citing absence of students.

Campus
The school had the following structures:

The double-storeyed main building, along with the annexe. 
Teachers' block.
A large playing field.

Students
The school was a Co-education school. Students of this school found place in the merit list of Board of Secondary Education, Madhya Pradesh. They got selections in the topmost medical and engineering institutes of India. Students always feel proud to be a part of such a good school.

Extra curricular activities
The school offered students an extensive array of extra curricular opportunities, such as the creative arts and a wide range of sport.

Sports
Besides the annual sports events, the school had regular cricket team that participates in inter-school championships. This school had produced some of the finest athletes in Bhopal.

Ceremonies
The Independence day (15 August) is a great annual ceremony. They had their own Annual function in which students perform and also receive awards for their best performance in studies as well as in extra-curricular activities.

Curriculum
This school was a higher secondary school (from class 1 to 12). The curriculum was governed by the Board of Secondary Education, Madhya Pradesh. It was the only Board school of Bhopal having ISO certification.

References

External links
 BHEL Shiksha Mandal

Schools in Bhopal
Educational institutions established in 1972
BHEL
Jymy-class motor torpedo boat. The Jymy-class motor torpedo boats (English: "Rumble") or J class was an Italian-designed and built class of motor torpedo boats, seeing service during World War II with the Royal Italian Navy and later with the Finnish Navy. The four boats of the J class were built by Cantieri Baglietto in Genoa, Italy and purchased by the Finns on 5 June 1943. Following World War II, the vessels were rearmed according to the Paris Peace Treaty of 1947, losing their torpedo capabilities and given more guns. They were removed from service in 1961.

Design and description
The J class were initially four motor torpedo boats of the Italian . The MAS 526 class were a lengthened version of the preceding  with a displacement of , measuring  long with a beam of  and a draught of . The motor torpedo boats were propelled by two propellers powered by two Isotta-Fraschini petrol engines creating . They had a maximum speed of . The vessels carried  of fuel giving them a range of  at  or  at 42 knots. The J class were armed with two  torpedo tubes, one  Breda gun and one  machine gun.

Vessels of the class

Construction and career
All four vessels were constructed in Italy and served with the Royal Italian Navy during World War II. Finland acquired the four motor torpedo boats on 5 June 1943. The Paris Peace Treaty of 1947 was signed following the end of World War II, and Finland was prohibited by the treaty from having torpedo-carrying vessels. The ships were converted into motor gunboats in 1949, in accordance with the treaty. The vessels were rearmed with a  gun in addition to the 20 mm gun. Their maximum speed was reduced to  and their displacement decreased to . The J-class vessels were stricken from the naval vessel register in 1961.

Citations

References
 
 
 
 
 

Torpedo boats of the Finnish Navy
Torpedo boat classes
Pythagoras Mechanical Workshop Museum. Pythagoras Mechanical Workshop Museum () is located in the premises of the earlier engine factory Pythagoras at the town of Norrtälje in the province of Uppland in Sweden. At the museum, production facilities and working conditions from the first half of the 20th century are on display. The factory produced hot bulb engines and spare parts for them from 1908 up to closure of the workshop in 1979. The engine factory is an industrial heritage site, complete with functioning production lines and offices.

Pythagoras company
The company was founded in 1898 as Verkstads AB Pythagoras (Pythagoras Mechanical Workshop Ltd.), originally to produce mechanical calculators, hence its name from the Greek mathematician and philosopher Pythagoras. However, these plans failed and the factory instead started producing locks, brass candlesticks and electrical fittings. Beginning in 1908 hot bulb engines were designed and manufactured, and such engines afterwards dominated the production line of the Pythagoras factory.

New Pythagoras
After a bankruptcy in 1927 the company was reconstituted as Nya AB Pythagoras (New Pythagoras Ltd.). A new bankruptcy followed during the Great Depression, in 1933, but it was reorganized once more. From 1957 and onwards, under new owners, the production was step by step reduced.

Fram and Drott
Pythagoras manufactured hot bulb engines under the trademarks of  Fram and Drott, the latter for export markets. The engines were used in farm machinery and on fishing and other vessels. The company was, with about 80 employees, once the largest manufacturer in Norrtälje.

Pythagoras today
The factory was threatened by demolition in the early 1980s, but was rescued by a group of local enthusiasts. Nowadays the Pythagoras Engine Factory is recognized as one of the most valuable industrial heritage monuments in Sweden. The Pythagoras  Mechanical Workshop Museum is owned by the Engine Factory Pythagoras Foundation, which runs it in cooperation with the support group Pythagoras Vänner (The Friends of Pythagoras).

Further reading (in Swedish)
Dag Avango: Motorfabriken Pythagoras – En levande verkstadsindustri och kulturmiljö, 1998, 
Jan-Bertil Schnell: ”Motorfabriken Pythagoras, ett törnroseslott i Roslagen”, in the 1993 yearbook of the Swedish Tourist Association

External links
Official homepage of the Pythagoras Workshop Museum
Official homepage of The Friends of Pythagoras (only in Swedish)

Pythagoras
Museums in Stockholm County
Uppland
1898 establishments in Sweden
Locksmithing museums
Marine engine manufacturers
Electrical engineering companies
Defunct companies of Sweden
Great Depression in Sweden
1979 disestablishments in Sweden
1980s establishments in Sweden
Industrial tourism
George A. Philbrick. George A. Philbrick was responsible, through his company George A. Philbrick Researches (GAP/R), for the 1953 commercialization and wide adoption of operational amplifiers, a now-ubiquitous component of analog electronic systems, and the invention and commercialization of electronic analog computers based on the operational amplifier principle. He also created the first electronic training simulator, the Polyphemus. The invention, or co-invention, of the operational amplifier has also been credited to a number of other people, including a war-needs driven Bell Labs team led by Clarence A. Lovell (C. A. Lovell et al., 1940 ff.) and Loebe Julie.

The actual naming of the operational amplifier likely occurred in the classic 1947 paper by John Ragazzini, et al.  However analog computations using op amps as we know them today began with the work of the Clarence Lovell-led war needs group at Bell Labs, around 1940 (acknowledged generally in John Ragazzini's paper).  In 1952, George A. Philbrick Researches (GAP/R) introduces the K2-W, considered the “Model T” of op amps.

See also 
 Bob Pease
 Bob Widlar

External links 
 The Philbrick Archive
 EEtimes.com: Unsung hero pioneered op amp

Bibliography
 Lovell, C.A., et al., "Artillery Predictor," US Patent 2,404,081, filed May 1, 1941, issued September 24, 1946. (The mathematics of analog computer system using op amps for functions of repeating, inverting and summing amplifiers, plus differentiation). 
 Lovell, C.A., et al., "Electrical Computing System," US Patent 2,404,387, filed May 1, 1941, issued July 23, 1946. (An analog computer system using op amps for control). 
 Lovell, C. A. "Continuous Electrical Computation," Bell Laboratories Record, 25, March, 1947, pp. 1 14–118. (An overview of various fire-control analog computational circuits of the T10 and M9 systems, many illustrating uses of op amps).
 Nyquist, H. “Regeneration theory,” Bell System Technical Journal, vol. 11, pp. 126–147, Jan. 1932.
 Black, H.S. “Stabilized feedback amplifiers,” Bell System Technical Journal, vol. 13, pp. 1–18, Jan. 1934.
 Bode, H.W. “Relations between attenuation and phase in feedback amplifier design,” Bell System Technical Journal, vol. 19, pp. 412–454, July 1940.
 Lovell, C. A. “Continuous electrical computation,” Bell Laboratories Record, vol. 25, no. 3, pp. 114–118, Mar. 1947.
 Ragazzini, J.R., Randall, R.H., and Russell, F.A. “Analysis of problems in dynamics by electronic circuits,” Proceedings of the IRE, vol. 35, pp. 444–452, May 1947.
 Philbrick, G.A. “Designing industrial controllers by analog,” Electronics, vol. 21, no. 6, pp. 108–111, 1948. Analog Circuit Design 12 34.

References

American engineers
Analog electronics engineers
Year of death missing
Shardul-class tank landing ship. Shardul-class landing ships are large amphibious warfare vessels built at Garden Reach Shipbuilders and Engineers for the Indian Navy. They are an evolution of the  amphibious landing ships. Initially, the ship was classified as Landing Ship Tank (Large) or LST(L). The class has an indigenous content of over 90%. The ships also carry four landing craft vehicle personnel (LCVP) on board, which can be used for the landing of troops.

History
The order for the vessels were placed in December 2001 while the contract was signed in early 2002.

The ship is equipped with WM-18 140 mm rocket launchers, developed by DRDO and manufactured by Larsen & Toubro. Two units of the system is integrated with one each on port and starboard. The rocket launcher has 18 tubes in a configuration of 6×3. These are used for beach clearing operations before initiating amphibious operations. The armament also includes four CRN-91 autocannons for self-defence.

Shardul was the first vessel commissioned at Karwar Naval Base, INS Kadamba. The second ship Kesari was commissioned at the Visakhapatnam Naval Base, and later moved to Port Blair. The third ship Airavata underwent sea trials in 2008 and was commissioned in 2009.

Ships

Gallery

See also
List of active Indian Navy ships

References

External links

Shardul Class - Bharat Rakshak
Launch of INS Kesari
Shardul handed over to Navy
GRSE hands over Shardul to Indian Navy

 
Amphibious warfare vessel classes
Ships built in India
Acceptor (semiconductors). In semiconductor physics, an acceptor is a dopant atom that when substituted into a semiconductor lattice forms a p-type region.

When silicon (Si), having four valence electrons, is doped with elements from group III of the periodic table, such as boron (B) and aluminium (Al), both having three valence electrons, a p-type semiconductor is formed. These dopant elements represent trivalent impurities. Other trivalent dopants include indium (In) and gallium (Ga).

When substituting for a silicon atom in the crystal lattice, the three valence electrons of boron form covalent bonds with three of the Si neighbours but the bond with the fourth remains unsatisfied. The initially electro-neutral acceptor becomes negatively charged (ionised). The unsatisfied bond attracts electrons from the neighbouring bonds. At room temperature, an electron from a neighbouring bond can jump to repair the unsatisfied bond thus leaving an electron hole, which is a place where an electron is deficient. The hole, being positively charged, attracts another electron from a neighbouring bond to repair this unsatisfied bond. This chain-like process results in the hole moving around the crystal as a charge carrier. This process can sustain in an electric current useful in electronic circuits.

See also
 Donor (semiconductors)
 Electron acceptor
 Semiconductors

References

Semiconductor properties
Digital clock manager. A digital clock manager (DCM) is an electronic component available on some field-programmable gate arrays (FPGAs) (notably ones produced by Xilinx). A digital clock manager is useful for manipulating clock signals inside the FPGA, and to avoid clock skew which would introduce errors in the circuit.

Uses
Digital clock managers have the following applications:

 Multiplying or dividing an incoming clock (which can come from outside the FPGA or from a Digital Frequency Synthesizer [DFS]).
 Making sure the clock has a steady duty cycle.
 Adding a phase shift with the additional use of a delay-locked loop.
 Eliminating clock skew within an FPGA design.

See also
 Phase-locked loop

References 

Gate arrays
Electronic oscillators
Integrated circuits
Digital electronics
Electronic design
Donor (semiconductors). In semiconductor physics, a donor is a dopant atom that, when added to a semiconductor, can form a n-type region. 

For example, when silicon (Si), having four valence electrons, is to be doped as a n-type semiconductor, elements from group V like phosphorus (P) or arsenic (As) can be used because they have five valence electrons. A dopant with five valence electrons is also called a pentavalent impurity.  Other pentavalent dopants are antimony (Sb) and  bismuth (Bi).

When substituting a Si atom in the crystal lattice, four of the valence electrons of phosphorus form covalent bonds with the neighbouring Si atoms but the fifth one remains weakly bonded.  If that electron is liberated, the initially electro-neutral donor becomes positively charged (ionised). At room temperature, the liberated electron can move around the Si crystal and carry a current, thus acting as a charge carrier.

See also
 Acceptor (semiconductors)
 Electron donor

References

Semiconductor properties
JRF. JRF may refer to:

Academia 
 Jackie Robinson Foundation, in the United States
 Junior Research Fellowship, in India
 Junior Research Fellowships, at Oxford and Cambridge

Non-profit organisations 
 Jackie Robinson Foundation, United States (formed 1973)
 Jewish Reconstructionist Federation, North America (formed 1955)
 Jordan River Foundation, Jordan (formed 1995)
 Joseph Rowntree Foundation, United Kingdom (formed 1904)

Transport 
 James River Freeway, a road in Missouri, United States
 Japan Freight Railway Company
 Jarala railway station, Pakistan
 Kalaeloa Airport, O'ahu, Hawaii, United States
 Naval Air Station Barbers Point, its precursor
CallAir Model A. The Call-Air Model A is an American two- to three-seat utility aircraft designed by the Call brothers and built by the Call Aircraft Company, later developed into a successful line of agricultural aircraft.

Design and development
The Model A was designed by the Call family, who were Wyoming ranchers. The aircraft was ready to be produced in 1940 but the start of World War II delayed the start of production to 1946. The family had formed the Call Aircraft Company (known as Call-Air) to produce the aircraft. The prototype Model A was powered by a Continental A-80 engine but was redesignated the Model A-1 when re-engined with an Avco Lycoming O-235-A engine. A United States type certificate was awarded in July 1944 and the production model was designated the Model A-2. The Model A-2  was a two-seat braced low-wing monoplane with fabric-covered wooden wings and fabric-covered welded steel tube. It had a fixed tailwheel landing gear. Further models were introduced with different engines. Examples of the three-seat A-4 were converted for agricultural use followed by a new-build agricultural version the A-5. In 1962 the assets of the company were acquired at auction by the Intermountain Manufacturing Company (IMCO) who developed their own version the IMCO CallAir A-9. IMCO was later taken over by the Aero Commander division of the Rockwell Standard Corporation and later became part of North American Rockwell, the design was further developed and redesignated.

Variants
A
Continental A-80-engined prototype, one built converted to A-1
A-1
Re-engined with an Avco Lycoming O-235-a engine, four built and prototype converted.
A-2
Two-seat cabin monoplane production version powered by an Avco Lycoming O-290-a engine, 16 built.
A-3
125 hp (93 kw) Continental C-125-2-powered version, 15 built.
A-4
Two/three-seat cabin monoplane version powered by a 135 hp (101 kw) Avco Lycoming O-290-D2 engine, 65 built.
A-5
Open-cockpit two-seat agricultural version of the A-4, 74 built.
A-5T Texan
A-5 with revised fuselage structure, nine built.
A-6
Improved version of A-5 with Avco Lycoming O-360-A1A engine, 34 built.
A-7
Similar to A-5 powered by West Coast Dusting-built Continental W-670-240 engine. One converted from an A-6
A-7T
Proposed development of A-7 with higher gross weight

Specifications (A-2)

References

Further reading

External links

Vintage Aircraft Museum

1940s United States civil utility aircraft
Low-wing aircraft
Single-engined tractor aircraft
Aircraft first flown in 1940
Vickers Venture. The Vickers Type 94 Venture was a British army cooperation biplane of the 1920s, designed and built by Vickers, as a development of the Vixen. While six were built for the Royal Air Force, they were found unsuitable and were used for experimental work.

Development and design
The Venture was a further development of the Vixen II to meet the requirements of Air Ministry Specification 45/23, six aircraft being ordered. The Venture, like the Vixen which formed its basis, was a single-bay biplane with a steel tube fuselage and wooden wings. It used the wings of the Vixen II with the lengthened fuselage of the Vixen III. The first Venture flew at the Vickers factory at Brooklands on 3 June 1924, being sent to the Aeroplane and Armament Experimental Establishment at Martlesham for evaluation. While demonstrating what was said to be "docile" handling, further testing showed that the aircraft had poor longitudinal stability, had a long landing run and was considered too large for use in army cooperation, where it would be expected to operate out of small airstrips. While it underwent brief service trials with No. 4 Squadron, the six Ventures were relegated to experimental purposes, the final aircraft being struck off charge in January 1933.

Operators

Royal Air Force

Specifications (Venture)

See also

References

1920s British military reconnaissance aircraft
Venture
Single-engined tractor aircraft
Biplanes
Aircraft first flown in 1924
Aircraft with fixed conventional landing gear